From e74e396204bfcb67570ba4517b08f5918e69afea Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 30 Mar 2009 19:07:44 +0900 Subject: percpu: use dynamic percpu allocator as the default percpu allocator This patch makes most !CONFIG_HAVE_SETUP_PER_CPU_AREA archs use dynamic percpu allocator. The first chunk is allocated using embedding helper and 8k is reserved for modules. This ensures that the new allocator behaves almost identically to the original allocator as long as static percpu variables are concerned, so it shouldn't introduce much breakage. s390 and alpha use custom SHIFT_PERCPU_PTR() to work around addressing range limit the addressing model imposes. Unfortunately, this breaks if the address is specified using a variable, so for now, the two archs aren't converted. The following architectures are affected by this change. * sh * arm * cris * mips * sparc(32) * blackfin * avr32 * parisc (broken, under investigation) * m32r * powerpc(32) As this change makes the dynamic allocator the default one, CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is replaced with its invert - CONFIG_HAVE_LEGACY_PER_CPU_AREA, which is added to yet-to-be converted archs. These archs implement their own setup_per_cpu_areas() and the conversion is not trivial. * powerpc(64) * sparc(64) * ia64 * alpha * s390 Boot and batch alloc/free tests on x86_32 with debug code (x86_32 doesn't use default first chunk initialization). Compile tested on sparc(32), powerpc(32), arm and alpha. Kyle McMartin reported that this change breaks parisc. The problem is still under investigation and he is okay with pushing this patch forward and fixing parisc later. [ Impact: use dynamic allocator for most archs w/o custom percpu setup ] Signed-off-by: Tejun Heo Acked-by: Rusty Russell Acked-by: David S. Miller Acked-by: Benjamin Herrenschmidt Acked-by: Martin Schwidefsky Reviewed-by: Christoph Lameter Cc: Paul Mundt Cc: Russell King Cc: Mikael Starvik Cc: Ralf Baechle Cc: Bryan Wu Cc: Kyle McMartin Cc: Matthew Wilcox Cc: Grant Grundler Cc: Hirokazu Takata Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Heiko Carstens Cc: Ingo Molnar --- kernel/module.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 38928fcaff2b..f5934954fa99 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -364,7 +364,7 @@ EXPORT_SYMBOL_GPL(find_module); #ifdef CONFIG_SMP -#ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA +#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA static void *percpu_modalloc(unsigned long size, unsigned long align, const char *name) @@ -389,7 +389,7 @@ static void percpu_modfree(void *freeme) free_percpu(freeme); } -#else /* ... !CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */ +#else /* ... CONFIG_HAVE_LEGACY_PER_CPU_AREA */ /* Number of blocks used and allocated. */ static unsigned int pcpu_num_used, pcpu_num_allocated; @@ -535,7 +535,7 @@ static int percpu_modinit(void) } __initcall(percpu_modinit); -#endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */ +#endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */ static unsigned int find_pcpusec(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, -- cgit v1.2.2 From b9bf3121af348d9255f1c917830fe8c2df52efcb Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Jun 2009 15:13:47 +0900 Subject: percpu: use DEFINE_PER_CPU_SHARED_ALIGNED() There are a few places where ___cacheline_aligned* is used with DEFINE_PER_CPU(). Use DEFINE_PER_CPU_SHARED_ALIGNED() instead. DEFINE_PER_CPU_SHARED_ALIGNED() applies alignment only on SMPs. While all other converted places used _in_smp variant or only get compiled for SMP, net/rds used unconditional ____cacheline_aligned. I don't see any reason these data structures should be aligned on UP and thus converted together. Signed-off-by: Tejun Heo Cc: Mike Frysinger Cc: Tony Luck Cc: Andy Grover --- kernel/sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 7c9098d186e6..34fd81d21784 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -318,12 +318,12 @@ struct task_group root_task_group; /* Default task group's sched entity on each cpu */ static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); /* Default task group's cfs_rq on each cpu */ -static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp; +static DEFINE_PER_CPU_SHARED_ALIGNED(struct cfs_rq, init_cfs_rq); #endif /* CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_RT_GROUP_SCHED static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); -static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp; +static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq); #endif /* CONFIG_RT_GROUP_SCHED */ #else /* !CONFIG_USER_SCHED */ #define root_task_group init_task_group -- cgit v1.2.2 From 245b2e70eabd797932adb263a65da0bab3711753 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Jun 2009 15:13:48 +0900 Subject: percpu: clean up percpu variable definitions Percpu variable definition is about to be updated such that all percpu symbols including the static ones must be unique. Update percpu variable definitions accordingly. * as,cfq: rename ioc_count uniquely * cpufreq: rename cpu_dbs_info uniquely * xen: move nesting_count out of xen_evtchn_do_upcall() and rename it * mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and rename it * ipv4,6: rename cookie_scratch uniquely * x86 perf_counter: rename prev_left to pmc_prev_left, irq_entry to pmc_irq_entry and nmi_entry to pmc_nmi_entry * perf_counter: rename disable_count to perf_disable_count * ftrace: rename test_event_disable to ftrace_test_event_disable * kmemleak: rename test_pointer to kmemleak_test_pointer * mce: rename next_interval to mce_next_interval [ Impact: percpu usage cleanups, no duplicate static percpu var names ] Signed-off-by: Tejun Heo Reviewed-by: Christoph Lameter Cc: Ivan Kokshaysky Cc: Jens Axboe Cc: Dave Jones Cc: Jeremy Fitzhardinge Cc: linux-mm Cc: David S. Miller Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Li Zefan Cc: Catalin Marinas Cc: Andi Kleen --- kernel/perf_counter.c | 6 +++--- kernel/trace/trace_events.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 1a933a221ea4..1fd7a2e75754 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -98,16 +98,16 @@ hw_perf_group_sched_in(struct perf_counter *group_leader, void __weak perf_counter_print_debug(void) { } -static DEFINE_PER_CPU(int, disable_count); +static DEFINE_PER_CPU(int, perf_disable_count); void __perf_disable(void) { - __get_cpu_var(disable_count)++; + __get_cpu_var(perf_disable_count)++; } bool __perf_enable(void) { - return !--__get_cpu_var(disable_count); + return !--__get_cpu_var(perf_disable_count); } void perf_disable(void) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index aa08be69a1b6..54b1de5074b6 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1318,7 +1318,7 @@ static __init void event_trace_self_tests(void) #ifdef CONFIG_FUNCTION_TRACER -static DEFINE_PER_CPU(atomic_t, test_event_disable); +static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); static void function_test_events_call(unsigned long ip, unsigned long parent_ip) @@ -1334,7 +1334,7 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip) pc = preempt_count(); resched = ftrace_preempt_disable(); cpu = raw_smp_processor_id(); - disabled = atomic_inc_return(&per_cpu(test_event_disable, cpu)); + disabled = atomic_inc_return(&per_cpu(ftrace_test_event_disable, cpu)); if (disabled != 1) goto out; @@ -1352,7 +1352,7 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip) trace_nowake_buffer_unlock_commit(event, flags, pc); out: - atomic_dec(&per_cpu(test_event_disable, cpu)); + atomic_dec(&per_cpu(ftrace_test_event_disable, cpu)); ftrace_preempt_enable(resched); } -- cgit v1.2.2 From 951ed4d36b77ba9fe1ea08fc3c59d8bb6c9bda32 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 7 Jul 2009 11:27:28 +0200 Subject: timekeeping: optimized ktime_get[_ts] for GENERIC_TIME=y The generic ktime_get function defined in kernel/hrtimer.c is suboptimial for GENERIC_TIME=y: 0) | ktime_get() { 0) | ktime_get_ts() { 0) | getnstimeofday() { 0) | read_tod_clock() { 0) 0.601 us | } 0) 1.938 us | } 0) | set_normalized_timespec() { 0) 0.602 us | } 0) 4.375 us | } 0) 5.523 us | } Overall there are two read_seqbegin/read_seqretry loops and a lot of unnecessary struct timespec calculations. ktime_get returns a nano second value which is the sum of xtime, wall_to_monotonic and the nano second delta from the clock source. ktime_get can be optimized for GENERIC_TIME=y. The new version only calls clocksource_read: 0) | ktime_get() { 0) | read_tod_clock() { 0) 0.610 us | } 0) 1.977 us | } It uses a single read_seqbegin/readseqretry loop and just adds everthing to a nano second value. ktime_get_ts is optimized in a similar fashion. [ tglx: added WARN_ON(timekeeping_suspended) as in getnstimeofday() ] Signed-off-by: Martin Schwidefsky Acked-by: john stultz LKML-Reference: <20090707112728.3005244d@skybase> Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 4 +++ kernel/time/timekeeping.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 73 insertions(+) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 9002958a96e7..829e0664b72e 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -48,6 +48,7 @@ #include +#ifndef CONFIG_GENERIC_TIME /** * ktime_get - get the monotonic time in ktime_t format * @@ -62,6 +63,7 @@ ktime_t ktime_get(void) return timespec_to_ktime(now); } EXPORT_SYMBOL_GPL(ktime_get); +#endif /** * ktime_get_real - get the real (wall-) time in ktime_t format @@ -106,6 +108,7 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = } }; +#ifndef CONFIG_GENERIC_TIME /** * ktime_get_ts - get the monotonic clock in timespec format * @ts: pointer to timespec variable @@ -130,6 +133,7 @@ void ktime_get_ts(struct timespec *ts) ts->tv_nsec + tomono.tv_nsec); } EXPORT_SYMBOL_GPL(ktime_get_ts); +#endif /* * Get the coarse grained time at the softirq based on xtime and diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index e8c77d9c633a..7a248135c6f2 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -125,6 +125,75 @@ void getnstimeofday(struct timespec *ts) EXPORT_SYMBOL(getnstimeofday); +ktime_t ktime_get(void) +{ + cycle_t cycle_now, cycle_delta; + unsigned int seq; + s64 secs, nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqbegin(&xtime_lock); + secs = xtime.tv_sec + wall_to_monotonic.tv_sec; + nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; + + /* read clocksource: */ + cycle_now = clocksource_read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* convert to nanoseconds: */ + nsecs += cyc2ns(clock, cycle_delta); + + } while (read_seqretry(&xtime_lock, seq)); + /* + * Use ktime_set/ktime_add_ns to create a proper ktime on + * 32-bit architectures without CONFIG_KTIME_SCALAR. + */ + return ktime_add_ns(ktime_set(secs, 0), nsecs); +} +EXPORT_SYMBOL_GPL(ktime_get); + +/** + * ktime_get_ts - get the monotonic clock in timespec format + * @ts: pointer to timespec variable + * + * The function calculates the monotonic clock from the realtime + * clock and the wall_to_monotonic offset and stores the result + * in normalized timespec format in the variable pointed to by @ts. + */ +void ktime_get_ts(struct timespec *ts) +{ + cycle_t cycle_now, cycle_delta; + struct timespec tomono; + unsigned int seq; + s64 nsecs; + + WARN_ON(timekeeping_suspended); + + do { + seq = read_seqbegin(&xtime_lock); + *ts = xtime; + tomono = wall_to_monotonic; + + /* read clocksource: */ + cycle_now = clocksource_read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* convert to nanoseconds: */ + nsecs = cyc2ns(clock, cycle_delta); + + } while (read_seqretry(&xtime_lock, seq)); + + set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, + ts->tv_nsec + tomono.tv_nsec + nsecs); +} +EXPORT_SYMBOL_GPL(ktime_get_ts); + /** * do_gettimeofday - Returns the time of day in a timeval * @tv: pointer to the timeval to be set -- cgit v1.2.2 From a40f262cc21fbfd781bbddcc40b16b83a75f5f34 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 7 Jul 2009 13:00:31 +0200 Subject: timekeeping: Move ktime_get() functions to timekeeping.c The ktime_get() functions for GENERIC_TIME=n are still located in hrtimer.c. Move them to time/timekeeping.c where they belong. LKML-Reference: Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 60 ----------------------------------------------- kernel/time/timekeeping.c | 59 ++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 57 insertions(+), 62 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 829e0664b72e..43d151f185b6 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -48,39 +48,6 @@ #include -#ifndef CONFIG_GENERIC_TIME -/** - * ktime_get - get the monotonic time in ktime_t format - * - * returns the time in ktime_t format - */ -ktime_t ktime_get(void) -{ - struct timespec now; - - ktime_get_ts(&now); - - return timespec_to_ktime(now); -} -EXPORT_SYMBOL_GPL(ktime_get); -#endif - -/** - * ktime_get_real - get the real (wall-) time in ktime_t format - * - * returns the time in ktime_t format - */ -ktime_t ktime_get_real(void) -{ - struct timespec now; - - getnstimeofday(&now); - - return timespec_to_ktime(now); -} - -EXPORT_SYMBOL_GPL(ktime_get_real); - /* * The timer bases: * @@ -108,33 +75,6 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = } }; -#ifndef CONFIG_GENERIC_TIME -/** - * ktime_get_ts - get the monotonic clock in timespec format - * @ts: pointer to timespec variable - * - * The function calculates the monotonic clock from the realtime - * clock and the wall_to_monotonic offset and stores the result - * in normalized timespec format in the variable pointed to by @ts. - */ -void ktime_get_ts(struct timespec *ts) -{ - struct timespec tomono; - unsigned long seq; - - do { - seq = read_seqbegin(&xtime_lock); - getnstimeofday(ts); - tomono = wall_to_monotonic; - - } while (read_seqretry(&xtime_lock, seq)); - - set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, - ts->tv_nsec + tomono.tv_nsec); -} -EXPORT_SYMBOL_GPL(ktime_get_ts); -#endif - /* * Get the coarse grained time at the softirq based on xtime and * wall_to_monotonic. diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 7a248135c6f2..02c0b2c9c674 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -290,10 +290,65 @@ static void change_clocksource(void) clock->name); */ } -#else +#else /* GENERIC_TIME */ static inline void clocksource_forward_now(void) { } static inline void change_clocksource(void) { } -#endif + +/** + * ktime_get - get the monotonic time in ktime_t format + * + * returns the time in ktime_t format + */ +ktime_t ktime_get(void) +{ + struct timespec now; + + ktime_get_ts(&now); + + return timespec_to_ktime(now); +} +EXPORT_SYMBOL_GPL(ktime_get); + +/** + * ktime_get_ts - get the monotonic clock in timespec format + * @ts: pointer to timespec variable + * + * The function calculates the monotonic clock from the realtime + * clock and the wall_to_monotonic offset and stores the result + * in normalized timespec format in the variable pointed to by @ts. + */ +void ktime_get_ts(struct timespec *ts) +{ + struct timespec tomono; + unsigned long seq; + + do { + seq = read_seqbegin(&xtime_lock); + getnstimeofday(ts); + tomono = wall_to_monotonic; + + } while (read_seqretry(&xtime_lock, seq)); + + set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, + ts->tv_nsec + tomono.tv_nsec); +} +EXPORT_SYMBOL_GPL(ktime_get_ts); +#endif /* !GENERIC_TIME */ + +/** + * ktime_get_real - get the real (wall-) time in ktime_t format + * + * returns the time in ktime_t format + */ +ktime_t ktime_get_real(void) +{ + struct timespec now; + + getnstimeofday(&now); + + return timespec_to_ktime(now); +} +EXPORT_SYMBOL_GPL(ktime_get_real); /** * getrawmonotonic - Returns the raw monotonic time in a timespec -- cgit v1.2.2 From 86886e55b273f565935491816c7c96b82469d4f8 Mon Sep 17 00:00:00 2001 From: Joseph Cihula Date: Tue, 30 Jun 2009 19:31:07 -0700 Subject: x86, intel_txt: Intel TXT Sx shutdown support Support for graceful handling of sleep states (S3/S4/S5) after an Intel(R) TXT launch. Without this patch, attempting to place the system in one of the ACPI sleep states (S3/S4/S5) will cause the TXT hardware to treat this as an attack and will cause a system reset, with memory locked. Not only may the subsequent memory scrub take some time, but the platform will be unable to enter the requested power state. This patch calls back into the tboot so that it may properly and securely clean up system state and clear the secrets-in-memory flag, after which it will place the system into the requested sleep state using ACPI information passed by the kernel. arch/x86/kernel/smpboot.c | 2 ++ drivers/acpi/acpica/hwsleep.c | 3 +++ kernel/cpu.c | 7 ++++++- 3 files changed, 11 insertions(+), 1 deletion(-) Signed-off-by: Joseph Cihula Signed-off-by: Shane Wang Signed-off-by: H. Peter Anvin --- kernel/cpu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index 8ce10043e4ac..ff071e022a85 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -14,6 +14,7 @@ #include #include #include +#include #ifdef CONFIG_SMP /* Serializes the updates to cpu_online_mask, cpu_present_mask */ @@ -376,7 +377,7 @@ static cpumask_var_t frozen_cpus; int disable_nonboot_cpus(void) { - int cpu, first_cpu, error; + int cpu, first_cpu, error, num_cpus = 0; error = stop_machine_create(); if (error) @@ -391,6 +392,7 @@ int disable_nonboot_cpus(void) for_each_online_cpu(cpu) { if (cpu == first_cpu) continue; + num_cpus++; error = _cpu_down(cpu, 1); if (!error) { cpumask_set_cpu(cpu, frozen_cpus); @@ -401,6 +403,9 @@ int disable_nonboot_cpus(void) break; } } + /* ensure all CPUs have gone into wait-for-SIPI */ + error |= tboot_wait_for_aps(num_cpus); + if (!error) { BUG_ON(num_online_cpus() > 1); /* Make sure the CPUs won't be enabled by someone else */ -- cgit v1.2.2 From fbd90375d7531927d312766b548376d909811b4d Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 22 Jul 2009 13:40:14 +0200 Subject: hrtimer: Remove cb_entry from struct hrtimer It's unused, remove it. Signed-off-by: Peter Zijlstra Signed-off-by: Thomas Gleixner LKML-Reference: --- kernel/hrtimer.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 43d151f185b6..052a0f53e4eb 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -1092,7 +1092,6 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, clock_id = CLOCK_MONOTONIC; timer->base = &cpu_base->clock_base[clock_id]; - INIT_LIST_HEAD(&timer->cb_entry); hrtimer_init_timer_hres(timer); #ifdef CONFIG_TIMER_STATS -- cgit v1.2.2 From 42c4ab41a176ee784c0f28c0b29025a8fc34f05a Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:26 +0200 Subject: itimers: Merge ITIMER_VIRT and ITIMER_PROF Both cpu itimers have same data flow in the few places, this patch make unification of code related with VIRT and PROF itimers. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-2-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- kernel/fork.c | 9 +-- kernel/itimer.c | 146 +++++++++++++++++++++------------------------- kernel/posix-cpu-timers.c | 98 +++++++++++++++---------------- 3 files changed, 119 insertions(+), 134 deletions(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 29b532e718f7..893ab0bf5e39 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -62,6 +62,7 @@ #include #include #include +#include #include #include @@ -790,10 +791,10 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig) thread_group_cputime_init(sig); /* Expiration times and increments. */ - sig->it_virt_expires = cputime_zero; - sig->it_virt_incr = cputime_zero; - sig->it_prof_expires = cputime_zero; - sig->it_prof_incr = cputime_zero; + sig->it[CPUCLOCK_PROF].expires = cputime_zero; + sig->it[CPUCLOCK_PROF].incr = cputime_zero; + sig->it[CPUCLOCK_VIRT].expires = cputime_zero; + sig->it[CPUCLOCK_VIRT].incr = cputime_zero; /* Cached expiration times. */ sig->cputime_expires.prof_exp = cputime_zero; diff --git a/kernel/itimer.c b/kernel/itimer.c index 58762f7077ec..852c88ddd1f0 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -41,10 +41,43 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer) return ktime_to_timeval(rem); } +static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, + struct itimerval *value) +{ + cputime_t cval, cinterval; + struct cpu_itimer *it = &tsk->signal->it[clock_id]; + + spin_lock_irq(&tsk->sighand->siglock); + + cval = it->expires; + cinterval = it->incr; + if (!cputime_eq(cval, cputime_zero)) { + struct task_cputime cputime; + cputime_t t; + + thread_group_cputimer(tsk, &cputime); + if (clock_id == CPUCLOCK_PROF) + t = cputime_add(cputime.utime, cputime.stime); + else + /* CPUCLOCK_VIRT */ + t = cputime.utime; + + if (cputime_le(cval, t)) + /* about to fire */ + cval = jiffies_to_cputime(1); + else + cval = cputime_sub(cval, t); + } + + spin_unlock_irq(&tsk->sighand->siglock); + + cputime_to_timeval(cval, &value->it_value); + cputime_to_timeval(cinterval, &value->it_interval); +} + int do_getitimer(int which, struct itimerval *value) { struct task_struct *tsk = current; - cputime_t cinterval, cval; switch (which) { case ITIMER_REAL: @@ -55,44 +88,10 @@ int do_getitimer(int which, struct itimerval *value) spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: - spin_lock_irq(&tsk->sighand->siglock); - cval = tsk->signal->it_virt_expires; - cinterval = tsk->signal->it_virt_incr; - if (!cputime_eq(cval, cputime_zero)) { - struct task_cputime cputime; - cputime_t utime; - - thread_group_cputimer(tsk, &cputime); - utime = cputime.utime; - if (cputime_le(cval, utime)) { /* about to fire */ - cval = jiffies_to_cputime(1); - } else { - cval = cputime_sub(cval, utime); - } - } - spin_unlock_irq(&tsk->sighand->siglock); - cputime_to_timeval(cval, &value->it_value); - cputime_to_timeval(cinterval, &value->it_interval); + get_cpu_itimer(tsk, CPUCLOCK_VIRT, value); break; case ITIMER_PROF: - spin_lock_irq(&tsk->sighand->siglock); - cval = tsk->signal->it_prof_expires; - cinterval = tsk->signal->it_prof_incr; - if (!cputime_eq(cval, cputime_zero)) { - struct task_cputime times; - cputime_t ptime; - - thread_group_cputimer(tsk, ×); - ptime = cputime_add(times.utime, times.stime); - if (cputime_le(cval, ptime)) { /* about to fire */ - cval = jiffies_to_cputime(1); - } else { - cval = cputime_sub(cval, ptime); - } - } - spin_unlock_irq(&tsk->sighand->siglock); - cputime_to_timeval(cval, &value->it_value); - cputime_to_timeval(cinterval, &value->it_interval); + get_cpu_itimer(tsk, CPUCLOCK_PROF, value); break; default: return(-EINVAL); @@ -128,6 +127,36 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } +static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, + struct itimerval *value, struct itimerval *ovalue) +{ + cputime_t cval, cinterval, nval, ninterval; + struct cpu_itimer *it = &tsk->signal->it[clock_id]; + + nval = timeval_to_cputime(&value->it_value); + ninterval = timeval_to_cputime(&value->it_interval); + + spin_lock_irq(&tsk->sighand->siglock); + + cval = it->expires; + cinterval = it->incr; + if (!cputime_eq(cval, cputime_zero) || + !cputime_eq(nval, cputime_zero)) { + if (cputime_gt(nval, cputime_zero)) + nval = cputime_add(nval, jiffies_to_cputime(1)); + set_process_cpu_timer(tsk, clock_id, &nval, &cval); + } + it->expires = nval; + it->incr = ninterval; + + spin_unlock_irq(&tsk->sighand->siglock); + + if (ovalue) { + cputime_to_timeval(cval, &ovalue->it_value); + cputime_to_timeval(cinterval, &ovalue->it_interval); + } +} + /* * Returns true if the timeval is in canonical form */ @@ -139,7 +168,6 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue) struct task_struct *tsk = current; struct hrtimer *timer; ktime_t expires; - cputime_t cval, cinterval, nval, ninterval; /* * Validate the timevals in value. @@ -174,48 +202,10 @@ again: spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: - nval = timeval_to_cputime(&value->it_value); - ninterval = timeval_to_cputime(&value->it_interval); - spin_lock_irq(&tsk->sighand->siglock); - cval = tsk->signal->it_virt_expires; - cinterval = tsk->signal->it_virt_incr; - if (!cputime_eq(cval, cputime_zero) || - !cputime_eq(nval, cputime_zero)) { - if (cputime_gt(nval, cputime_zero)) - nval = cputime_add(nval, - jiffies_to_cputime(1)); - set_process_cpu_timer(tsk, CPUCLOCK_VIRT, - &nval, &cval); - } - tsk->signal->it_virt_expires = nval; - tsk->signal->it_virt_incr = ninterval; - spin_unlock_irq(&tsk->sighand->siglock); - if (ovalue) { - cputime_to_timeval(cval, &ovalue->it_value); - cputime_to_timeval(cinterval, &ovalue->it_interval); - } + set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue); break; case ITIMER_PROF: - nval = timeval_to_cputime(&value->it_value); - ninterval = timeval_to_cputime(&value->it_interval); - spin_lock_irq(&tsk->sighand->siglock); - cval = tsk->signal->it_prof_expires; - cinterval = tsk->signal->it_prof_incr; - if (!cputime_eq(cval, cputime_zero) || - !cputime_eq(nval, cputime_zero)) { - if (cputime_gt(nval, cputime_zero)) - nval = cputime_add(nval, - jiffies_to_cputime(1)); - set_process_cpu_timer(tsk, CPUCLOCK_PROF, - &nval, &cval); - } - tsk->signal->it_prof_expires = nval; - tsk->signal->it_prof_incr = ninterval; - spin_unlock_irq(&tsk->sighand->siglock); - if (ovalue) { - cputime_to_timeval(cval, &ovalue->it_value); - cputime_to_timeval(cinterval, &ovalue->it_interval); - } + set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue); break; default: return -EINVAL; diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index bece7c0b67b2..9b2d5e4dc8c4 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -14,11 +14,11 @@ */ void update_rlimit_cpu(unsigned long rlim_new) { - cputime_t cputime; + cputime_t cputime = secs_to_cputime(rlim_new); + struct signal_struct *const sig = current->signal; - cputime = secs_to_cputime(rlim_new); - if (cputime_eq(current->signal->it_prof_expires, cputime_zero) || - cputime_gt(current->signal->it_prof_expires, cputime)) { + if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) || + cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) { spin_lock_irq(¤t->sighand->siglock); set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); spin_unlock_irq(¤t->sighand->siglock); @@ -613,6 +613,9 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) break; } } else { + struct signal_struct *const sig = p->signal; + union cpu_time_count *exp = &timer->it.cpu.expires; + /* * For a process timer, set the cached expiration time. */ @@ -620,30 +623,27 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) default: BUG(); case CPUCLOCK_VIRT: - if (!cputime_eq(p->signal->it_virt_expires, + if (!cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) && - cputime_lt(p->signal->it_virt_expires, - timer->it.cpu.expires.cpu)) + cputime_lt(sig->it[CPUCLOCK_VIRT].expires, + exp->cpu)) break; - p->signal->cputime_expires.virt_exp = - timer->it.cpu.expires.cpu; + sig->cputime_expires.virt_exp = exp->cpu; break; case CPUCLOCK_PROF: - if (!cputime_eq(p->signal->it_prof_expires, + if (!cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) && - cputime_lt(p->signal->it_prof_expires, - timer->it.cpu.expires.cpu)) + cputime_lt(sig->it[CPUCLOCK_PROF].expires, + exp->cpu)) break; - i = p->signal->rlim[RLIMIT_CPU].rlim_cur; + i = sig->rlim[RLIMIT_CPU].rlim_cur; if (i != RLIM_INFINITY && - i <= cputime_to_secs(timer->it.cpu.expires.cpu)) + i <= cputime_to_secs(exp->cpu)) break; - p->signal->cputime_expires.prof_exp = - timer->it.cpu.expires.cpu; + sig->cputime_expires.prof_exp = exp->cpu; break; case CPUCLOCK_SCHED: - p->signal->cputime_expires.sched_exp = - timer->it.cpu.expires.sched; + sig->cputime_expires.sched_exp = exp->sched; break; } } @@ -1070,6 +1070,27 @@ static void stop_process_timers(struct task_struct *tsk) spin_unlock_irqrestore(&cputimer->lock, flags); } +static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, + cputime_t *expires, cputime_t cur_time, int signo) +{ + if (cputime_eq(it->expires, cputime_zero)) + return; + + if (cputime_ge(cur_time, it->expires)) { + it->expires = it->incr; + if (!cputime_eq(it->expires, cputime_zero)) + it->expires = cputime_add(it->expires, cur_time); + + __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); + } + + if (!cputime_eq(it->expires, cputime_zero) && + (cputime_eq(*expires, cputime_zero) || + cputime_lt(it->expires, *expires))) { + *expires = it->expires; + } +} + /* * Check for any per-thread CPU timers that have fired and move them * off the tsk->*_timers list onto the firing list. Per-thread timers @@ -1089,10 +1110,10 @@ static void check_process_timers(struct task_struct *tsk, * Don't sample the current process CPU clocks if there are no timers. */ if (list_empty(&timers[CPUCLOCK_PROF]) && - cputime_eq(sig->it_prof_expires, cputime_zero) && + cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) && sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY && list_empty(&timers[CPUCLOCK_VIRT]) && - cputime_eq(sig->it_virt_expires, cputime_zero) && + cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) && list_empty(&timers[CPUCLOCK_SCHED])) { stop_process_timers(tsk); return; @@ -1152,38 +1173,11 @@ static void check_process_timers(struct task_struct *tsk, /* * Check for the special case process timers. */ - if (!cputime_eq(sig->it_prof_expires, cputime_zero)) { - if (cputime_ge(ptime, sig->it_prof_expires)) { - /* ITIMER_PROF fires and reloads. */ - sig->it_prof_expires = sig->it_prof_incr; - if (!cputime_eq(sig->it_prof_expires, cputime_zero)) { - sig->it_prof_expires = cputime_add( - sig->it_prof_expires, ptime); - } - __group_send_sig_info(SIGPROF, SEND_SIG_PRIV, tsk); - } - if (!cputime_eq(sig->it_prof_expires, cputime_zero) && - (cputime_eq(prof_expires, cputime_zero) || - cputime_lt(sig->it_prof_expires, prof_expires))) { - prof_expires = sig->it_prof_expires; - } - } - if (!cputime_eq(sig->it_virt_expires, cputime_zero)) { - if (cputime_ge(utime, sig->it_virt_expires)) { - /* ITIMER_VIRTUAL fires and reloads. */ - sig->it_virt_expires = sig->it_virt_incr; - if (!cputime_eq(sig->it_virt_expires, cputime_zero)) { - sig->it_virt_expires = cputime_add( - sig->it_virt_expires, utime); - } - __group_send_sig_info(SIGVTALRM, SEND_SIG_PRIV, tsk); - } - if (!cputime_eq(sig->it_virt_expires, cputime_zero) && - (cputime_eq(virt_expires, cputime_zero) || - cputime_lt(sig->it_virt_expires, virt_expires))) { - virt_expires = sig->it_virt_expires; - } - } + check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime, + SIGPROF); + check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime, + SIGVTALRM); + if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) { unsigned long psecs = cputime_to_secs(ptime); cputime_t x; -- cgit v1.2.2 From 8356b5f9c424e5831715abbce747197c30d1fd71 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:27 +0200 Subject: itimers: Fix periodic tics precision Measure ITIMER_PROF and ITIMER_VIRT timers interval error between real ticks and requested by user. Take it into account when scheduling next tick. This patch introduce possibility where time between two consecutive tics is smaller then requested interval, it preserve however dependency that n tick is generated not earlier than n*interval time - counting from the beginning of periodic signal generation. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-3-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- kernel/itimer.c | 24 +++++++++++++++++++++--- kernel/posix-cpu-timers.c | 20 +++++++++++++++++--- 2 files changed, 38 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/itimer.c b/kernel/itimer.c index 852c88ddd1f0..21adff7b2a17 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -42,7 +42,7 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer) } static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, - struct itimerval *value) + struct itimerval *const value) { cputime_t cval, cinterval; struct cpu_itimer *it = &tsk->signal->it[clock_id]; @@ -127,14 +127,32 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } +static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns) +{ + struct timespec ts; + s64 cpu_ns; + + cputime_to_timespec(ct, &ts); + cpu_ns = timespec_to_ns(&ts); + + return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns; +} + static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, - struct itimerval *value, struct itimerval *ovalue) + const struct itimerval *const value, + struct itimerval *const ovalue) { - cputime_t cval, cinterval, nval, ninterval; + cputime_t cval, nval, cinterval, ninterval; + s64 ns_ninterval, ns_nval; struct cpu_itimer *it = &tsk->signal->it[clock_id]; nval = timeval_to_cputime(&value->it_value); + ns_nval = timeval_to_ns(&value->it_value); ninterval = timeval_to_cputime(&value->it_interval); + ns_ninterval = timeval_to_ns(&value->it_interval); + + it->incr_error = cputime_sub_ns(ninterval, ns_ninterval); + it->error = cputime_sub_ns(nval, ns_nval); spin_lock_irq(&tsk->sighand->siglock); diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 9b2d5e4dc8c4..b60d644ea4b3 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1070,6 +1070,8 @@ static void stop_process_timers(struct task_struct *tsk) spin_unlock_irqrestore(&cputimer->lock, flags); } +static u32 onecputick; + static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, cputime_t *expires, cputime_t cur_time, int signo) { @@ -1077,9 +1079,16 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, return; if (cputime_ge(cur_time, it->expires)) { - it->expires = it->incr; - if (!cputime_eq(it->expires, cputime_zero)) - it->expires = cputime_add(it->expires, cur_time); + if (!cputime_eq(it->incr, cputime_zero)) { + it->expires = cputime_add(it->expires, it->incr); + it->error += it->incr_error; + if (it->error >= onecputick) { + it->expires = cputime_sub(it->expires, + jiffies_to_cputime(1)); + it->error -= onecputick; + } + } else + it->expires = cputime_zero; __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } @@ -1696,10 +1705,15 @@ static __init int init_posix_cpu_timers(void) .nsleep = thread_cpu_nsleep, .nsleep_restart = thread_cpu_nsleep_restart, }; + struct timespec ts; register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); + cputime_to_timespec(jiffies_to_cputime(1), &ts); + onecputick = ts.tv_nsec; + WARN_ON(ts.tv_sec != 0); + return 0; } __initcall(init_posix_cpu_timers); -- cgit v1.2.2 From d1e3b6d195770bd422e3229b88edfc154b6a27dd Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:28 +0200 Subject: itimers: Simplify arm_timer() code a bit Don't update values in expiration cache when new ones are equal. Add expire_le() and expire_gt() helpers to simplify the code. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-4-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- kernel/posix-cpu-timers.c | 44 +++++++++++++++++++++++--------------------- 1 file changed, 23 insertions(+), 21 deletions(-) (limited to 'kernel') diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index b60d644ea4b3..69c92374355f 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -541,6 +541,17 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now) now); } +static inline int expires_gt(cputime_t expires, cputime_t new_exp) +{ + return cputime_eq(expires, cputime_zero) || + cputime_gt(expires, new_exp); +} + +static inline int expires_le(cputime_t expires, cputime_t new_exp) +{ + return !cputime_eq(expires, cputime_zero) && + cputime_le(expires, new_exp); +} /* * Insert the timer on the appropriate list before any timers that * expire later. This must be called with the tasklist_lock held @@ -585,31 +596,26 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) */ if (CPUCLOCK_PERTHREAD(timer->it_clock)) { + union cpu_time_count *exp = &nt->expires; + switch (CPUCLOCK_WHICH(timer->it_clock)) { default: BUG(); case CPUCLOCK_PROF: - if (cputime_eq(p->cputime_expires.prof_exp, - cputime_zero) || - cputime_gt(p->cputime_expires.prof_exp, - nt->expires.cpu)) - p->cputime_expires.prof_exp = - nt->expires.cpu; + if (expires_gt(p->cputime_expires.prof_exp, + exp->cpu)) + p->cputime_expires.prof_exp = exp->cpu; break; case CPUCLOCK_VIRT: - if (cputime_eq(p->cputime_expires.virt_exp, - cputime_zero) || - cputime_gt(p->cputime_expires.virt_exp, - nt->expires.cpu)) - p->cputime_expires.virt_exp = - nt->expires.cpu; + if (expires_gt(p->cputime_expires.virt_exp, + exp->cpu)) + p->cputime_expires.virt_exp = exp->cpu; break; case CPUCLOCK_SCHED: if (p->cputime_expires.sched_exp == 0 || - p->cputime_expires.sched_exp > - nt->expires.sched) + p->cputime_expires.sched_exp > exp->sched) p->cputime_expires.sched_exp = - nt->expires.sched; + exp->sched; break; } } else { @@ -623,17 +629,13 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) default: BUG(); case CPUCLOCK_VIRT: - if (!cputime_eq(sig->it[CPUCLOCK_VIRT].expires, - cputime_zero) && - cputime_lt(sig->it[CPUCLOCK_VIRT].expires, + if (expires_le(sig->it[CPUCLOCK_VIRT].expires, exp->cpu)) break; sig->cputime_expires.virt_exp = exp->cpu; break; case CPUCLOCK_PROF: - if (!cputime_eq(sig->it[CPUCLOCK_PROF].expires, - cputime_zero) && - cputime_lt(sig->it[CPUCLOCK_PROF].expires, + if (expires_le(sig->it[CPUCLOCK_PROF].expires, exp->cpu)) break; i = sig->rlim[RLIMIT_CPU].rlim_cur; -- cgit v1.2.2 From a42548a18866e87092db93b771e6c5b060d78401 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:29 +0200 Subject: cputime: Optimize jiffies_to_cputime(1) For powerpc with CONFIG_VIRT_CPU_ACCOUNTING jiffies_to_cputime(1) is not compile time constant and run time calculations are quite expensive. To optimize we use precomputed value. For all other architectures is is preprocessor definition. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- kernel/itimer.c | 4 ++-- kernel/posix-cpu-timers.c | 6 +++--- kernel/sched.c | 9 ++++----- 3 files changed, 9 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/itimer.c b/kernel/itimer.c index 21adff7b2a17..8078a32d3b10 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -64,7 +64,7 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, if (cputime_le(cval, t)) /* about to fire */ - cval = jiffies_to_cputime(1); + cval = cputime_one_jiffy; else cval = cputime_sub(cval, t); } @@ -161,7 +161,7 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, if (!cputime_eq(cval, cputime_zero) || !cputime_eq(nval, cputime_zero)) { if (cputime_gt(nval, cputime_zero)) - nval = cputime_add(nval, jiffies_to_cputime(1)); + nval = cputime_add(nval, cputime_one_jiffy); set_process_cpu_timer(tsk, clock_id, &nval, &cval); } it->expires = nval; diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 69c92374355f..18bdde6f676f 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1086,7 +1086,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, it->error += it->incr_error; if (it->error >= onecputick) { it->expires = cputime_sub(it->expires, - jiffies_to_cputime(1)); + cputime_one_jiffy); it->error -= onecputick; } } else @@ -1461,7 +1461,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, if (!cputime_eq(*oldval, cputime_zero)) { if (cputime_le(*oldval, now.cpu)) { /* Just about to fire. */ - *oldval = jiffies_to_cputime(1); + *oldval = cputime_one_jiffy; } else { *oldval = cputime_sub(*oldval, now.cpu); } @@ -1712,7 +1712,7 @@ static __init int init_posix_cpu_timers(void) register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); - cputime_to_timespec(jiffies_to_cputime(1), &ts); + cputime_to_timespec(cputime_one_jiffy, &ts); onecputick = ts.tv_nsec; WARN_ON(ts.tv_sec != 0); diff --git a/kernel/sched.c b/kernel/sched.c index 1b59e265273b..8f977d5cc515 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5031,17 +5031,16 @@ void account_idle_time(cputime_t cputime) */ void account_process_tick(struct task_struct *p, int user_tick) { - cputime_t one_jiffy = jiffies_to_cputime(1); - cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy); + cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); struct rq *rq = this_rq(); if (user_tick) - account_user_time(p, one_jiffy, one_jiffy_scaled); + account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) - account_system_time(p, HARDIRQ_OFFSET, one_jiffy, + account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, one_jiffy_scaled); else - account_idle_time(one_jiffy); + account_idle_time(cputime_one_jiffy); } /* -- cgit v1.2.2 From 97fd9ed48ce2b807edc363bef3e817aeeb5cd5e6 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 21 Jul 2009 20:25:05 +0200 Subject: timers: Cache __next_timer_interrupt result Each time a cpu goes to sleep on a NOHZ=y system the timer wheel is searched for the next timer interrupt. It can take quite a few cycles to find the next pending timer. This patch adds a field to tvec_base that caches the result of __next_timer_interrupt. The hit ratio is around 80% on my thinkpad under normal use, on a server I've seen hit ratios from 5% to 95% dependent on the workload. -v2: jiffies wrap fixes Signed-off-by: Martin Schwidefsky Acked-by: Thomas Gleixner Cc: john stultz Cc: Venki Pallipadi LKML-Reference: <20090721202505.7d56a079@skybase> Signed-off-by: Ingo Molnar --- kernel/timer.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/timer.c b/kernel/timer.c index 0b36b9e5cc8b..5c1e49ec2f1b 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -72,6 +72,7 @@ struct tvec_base { spinlock_t lock; struct timer_list *running_timer; unsigned long timer_jiffies; + unsigned long next_timer; struct tvec_root tv1; struct tvec tv2; struct tvec tv3; @@ -622,6 +623,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires, if (timer_pending(timer)) { detach_timer(timer, 0); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } else { if (pending_only) @@ -663,6 +667,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires, } timer->expires = expires; + if (time_before(timer->expires, base->next_timer) && + !tbase_get_deferrable(timer->base)) + base->next_timer = timer->expires; internal_add_timer(base, timer); out_unlock: @@ -781,6 +788,9 @@ void add_timer_on(struct timer_list *timer, int cpu) spin_lock_irqsave(&base->lock, flags); timer_set_base(timer, base); debug_timer_activate(timer); + if (time_before(timer->expires, base->next_timer) && + !tbase_get_deferrable(timer->base)) + base->next_timer = timer->expires; internal_add_timer(base, timer); /* * Check whether the other CPU is idle and needs to be @@ -817,6 +827,9 @@ int del_timer(struct timer_list *timer) base = lock_timer_base(timer, &flags); if (timer_pending(timer)) { detach_timer(timer, 1); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } spin_unlock_irqrestore(&base->lock, flags); @@ -850,6 +863,9 @@ int try_to_del_timer_sync(struct timer_list *timer) ret = 0; if (timer_pending(timer)) { detach_timer(timer, 1); + if (timer->expires == base->next_timer && + !tbase_get_deferrable(timer->base)) + base->next_timer = base->timer_jiffies; ret = 1; } out: @@ -1134,7 +1150,9 @@ unsigned long get_next_timer_interrupt(unsigned long now) unsigned long expires; spin_lock(&base->lock); - expires = __next_timer_interrupt(base); + if (time_before_eq(base->next_timer, base->timer_jiffies)) + base->next_timer = __next_timer_interrupt(base); + expires = base->next_timer; spin_unlock(&base->lock); if (time_before_eq(expires, now)) @@ -1523,6 +1541,7 @@ static int __cpuinit init_timers_cpu(int cpu) INIT_LIST_HEAD(base->tv1.vec + j); base->timer_jiffies = jiffies; + base->next_timer = base->timer_jiffies; return 0; } @@ -1535,6 +1554,9 @@ static void migrate_timer_list(struct tvec_base *new_base, struct list_head *hea timer = list_first_entry(head, struct timer_list, entry); detach_timer(timer, 0); timer_set_base(timer, new_base); + if (time_before(timer->expires, new_base->next_timer) && + !tbase_get_deferrable(timer->base)) + new_base->next_timer = timer->expires; internal_add_timer(new_base, timer); } } -- cgit v1.2.2 From 31089c13bcb18d2cd2a3ddfbe3a28666346f237e Mon Sep 17 00:00:00 2001 From: John Stultz Date: Fri, 14 Aug 2009 15:47:18 +0200 Subject: timekeeping: Introduce timekeeping_leap_insert Move the adjustment of xtime, wall_to_monotonic and the update of the vsyscall variables to the timekeeping code. Signed-off-by: John Stultz Signed-off-by: Martin Schwidefsky LKML-Reference: <20090814134807.609730216@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/ntp.c | 7 ++----- kernel/time/timekeeping.c | 7 +++++++ 2 files changed, 9 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 7fc64375ff43..4800f933910e 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -194,8 +194,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) case TIME_OK: break; case TIME_INS: - xtime.tv_sec--; - wall_to_monotonic.tv_sec++; + timekeeping_leap_insert(-1); time_state = TIME_OOP; printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n"); @@ -203,9 +202,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) res = HRTIMER_RESTART; break; case TIME_DEL: - xtime.tv_sec++; + timekeeping_leap_insert(1); time_tai--; - wall_to_monotonic.tv_sec--; time_state = TIME_WAIT; printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n"); @@ -219,7 +217,6 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) time_state = TIME_OK; break; } - update_vsyscall(&xtime, clock); write_sequnlock(&xtime_lock); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 02c0b2c9c674..b8b70fb545fc 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -58,6 +58,13 @@ void update_xtime_cache(u64 nsec) struct clocksource *clock; +/* must hold xtime_lock */ +void timekeeping_leap_insert(int leapsecond) +{ + xtime.tv_sec += leapsecond; + wall_to_monotonic.tv_sec -= leapsecond; + update_vsyscall(&xtime, clock); +} #ifdef CONFIG_GENERIC_TIME /** -- cgit v1.2.2 From a0f7d48bfb95a4c5172a2756dbc4b82afc8e9ae4 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:19 +0200 Subject: timekeeping: Remove clocksource inline functions The three inline functions clocksource_read, clocksource_enable and clocksource_disable are simple wrappers of an indirect call plus the copy from and to the mult_orig value. The functions are exclusively used by the timekeeping code which has intimate knowledge of the clocksource anyway. Therefore remove the inline functions. No functional change. Signed-off-by: Martin Schwidefsky Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134807.903108946@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 41 ++++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index b8b70fb545fc..016a2591d719 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -79,7 +79,7 @@ static void clocksource_forward_now(void) cycle_t cycle_now, cycle_delta; s64 nsec; - cycle_now = clocksource_read(clock); + cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; clock->cycle_last = cycle_now; @@ -114,7 +114,7 @@ void getnstimeofday(struct timespec *ts) *ts = xtime; /* read clocksource: */ - cycle_now = clocksource_read(clock); + cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; @@ -146,7 +146,7 @@ ktime_t ktime_get(void) nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; /* read clocksource: */ - cycle_now = clocksource_read(clock); + cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; @@ -186,7 +186,7 @@ void ktime_get_ts(struct timespec *ts) tomono = wall_to_monotonic; /* read clocksource: */ - cycle_now = clocksource_read(clock); + cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; @@ -274,16 +274,29 @@ static void change_clocksource(void) clocksource_forward_now(); - if (clocksource_enable(new)) + if (new->enable && !new->enable(new)) return; + /* + * The frequency may have changed while the clocksource + * was disabled. If so the code in ->enable() must update + * the mult value to reflect the new frequency. Make sure + * mult_orig follows this change. + */ + new->mult_orig = new->mult; new->raw_time = clock->raw_time; old = clock; clock = new; - clocksource_disable(old); + /* + * Save mult_orig in mult so that the value can be restored + * regardless if ->enable() updates the value of mult or not. + */ + old->mult = old->mult_orig; + if (old->disable) + old->disable(old); clock->cycle_last = 0; - clock->cycle_last = clocksource_read(clock); + clock->cycle_last = clock->read(clock); clock->error = 0; clock->xtime_nsec = 0; clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); @@ -373,7 +386,7 @@ void getrawmonotonic(struct timespec *ts) seq = read_seqbegin(&xtime_lock); /* read clocksource: */ - cycle_now = clocksource_read(clock); + cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; @@ -435,9 +448,12 @@ void __init timekeeping_init(void) ntp_init(); clock = clocksource_get_next(); - clocksource_enable(clock); + if (clock->enable) + clock->enable(clock); + /* set mult_orig on enable */ + clock->mult_orig = clock->mult; clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); - clock->cycle_last = clocksource_read(clock); + clock->cycle_last = clock->read(clock); xtime.tv_sec = sec; xtime.tv_nsec = 0; @@ -477,8 +493,7 @@ static int timekeeping_resume(struct sys_device *dev) } update_xtime_cache(0); /* re-base the last cycle value */ - clock->cycle_last = 0; - clock->cycle_last = clocksource_read(clock); + clock->cycle_last = clock->read(clock); clock->error = 0; timekeeping_suspended = 0; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -630,7 +645,7 @@ void update_wall_time(void) return; #ifdef CONFIG_GENERIC_TIME - offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask; + offset = (clock->read(clock) - clock->cycle_last) & clock->mask; #else offset = clock->cycle_interval; #endif -- cgit v1.2.2 From 1be396794897f80bfc8774719ba60309a9e3d374 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:20 +0200 Subject: timekeeping: Move reset of cycle_last for tsc clocksource to tsc change_clocksource resets the cycle_last value to zero then sets it to a value read from the clocksource. The reset to zero is required only for the TSC clocksource to make the read_tsc function work after a resume. The reason is that the TSC read function uses cycle_last to detect backwards going TSCs. In the resume case cycle_last contains the TSC value from the last update before the suspend. On resume the TSC starts counting from 0 again and would trip over the cycle_last comparison. This is subtle and surprising. Move the reset to a resume function in the tsc code. Signed-off-by: Martin Schwidefsky Acked-by: Thomas Gleixner Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134808.142191175@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 016a2591d719..b5673016089f 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -295,7 +295,6 @@ static void change_clocksource(void) if (old->disable) old->disable(old); - clock->cycle_last = 0; clock->cycle_last = clock->read(clock); clock->error = 0; clock->xtime_nsec = 0; -- cgit v1.2.2 From f1b82746c1e93daf24e1ab9bfbd39bcdb2e7018b Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:21 +0200 Subject: clocksource: Cleanup clocksource selection If a non high-resolution clocksource is first set as override clock and then registered it becomes active even if the system is in one-shot mode. Move the override check from sysfs_override_clocksource to the clocksource selection. That fixes the bug and simplifies the code. The check in clocksource_register for double registration of the same clocksource is removed without replacement. To find the initial clocksource a new weak function in jiffies.c is defined that returns the jiffies clocksource. The architecture code can then override the weak function with a more suitable clocksource, e.g. the TOD clock on s390. [ tglx: Folded in a fix from John Stultz ] Signed-off-by: Martin Schwidefsky Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134808.388024160@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 134 ++++++++++++++++++---------------------------- kernel/time/jiffies.c | 6 ++- kernel/time/timekeeping.c | 4 +- 3 files changed, 58 insertions(+), 86 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 7466cb811251..e91662e87cde 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -21,7 +21,6 @@ * * TODO WishList: * o Allow clocksource drivers to be unregistered - * o get rid of clocksource_jiffies extern */ #include @@ -107,12 +106,9 @@ u64 timecounter_cyc2time(struct timecounter *tc, } EXPORT_SYMBOL(timecounter_cyc2time); -/* XXX - Would like a better way for initializing curr_clocksource */ -extern struct clocksource clocksource_jiffies; - /*[Clocksource internal variables]--------- * curr_clocksource: - * currently selected clocksource. Initialized to clocksource_jiffies. + * currently selected clocksource. * next_clocksource: * pending next selected clocksource. * clocksource_list: @@ -123,9 +119,8 @@ extern struct clocksource clocksource_jiffies; * override_name: * Name of the user-specified clocksource. */ -static struct clocksource *curr_clocksource = &clocksource_jiffies; +static struct clocksource *curr_clocksource; static struct clocksource *next_clocksource; -static struct clocksource *clocksource_override; static LIST_HEAD(clocksource_list); static DEFINE_SPINLOCK(clocksource_lock); static char override_name[32]; @@ -320,6 +315,7 @@ void clocksource_touch_watchdog(void) clocksource_resume_watchdog(); } +#ifdef CONFIG_GENERIC_TIME /** * clocksource_get_next - Returns the selected clocksource * @@ -339,56 +335,65 @@ struct clocksource *clocksource_get_next(void) } /** - * select_clocksource - Selects the best registered clocksource. + * clocksource_select - Select the best clocksource available * * Private function. Must hold clocksource_lock when called. * * Select the clocksource with the best rating, or the clocksource, * which is selected by userspace override. */ -static struct clocksource *select_clocksource(void) +static void clocksource_select(void) { - struct clocksource *next; + struct clocksource *best, *cs; if (list_empty(&clocksource_list)) - return NULL; + return; + /* First clocksource on the list has the best rating. */ + best = list_first_entry(&clocksource_list, struct clocksource, list); + /* Check for the override clocksource. */ + list_for_each_entry(cs, &clocksource_list, list) { + if (strcmp(cs->name, override_name) != 0) + continue; + /* + * Check to make sure we don't switch to a non-highres + * capable clocksource if the tick code is in oneshot + * mode (highres or nohz) + */ + if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && + tick_oneshot_mode_active()) { + /* Override clocksource cannot be used. */ + printk(KERN_WARNING "Override clocksource %s is not " + "HRT compatible. Cannot switch while in " + "HRT/NOHZ mode\n", cs->name); + override_name[0] = 0; + } else + /* Override clocksource can be used. */ + best = cs; + break; + } + if (curr_clocksource != best) + next_clocksource = best; +} - if (clocksource_override) - next = clocksource_override; - else - next = list_entry(clocksource_list.next, struct clocksource, - list); +#else /* CONFIG_GENERIC_TIME */ - if (next == curr_clocksource) - return NULL; +static void clocksource_select(void) { } - return next; -} +#endif /* * Enqueue the clocksource sorted by rating */ -static int clocksource_enqueue(struct clocksource *c) +static void clocksource_enqueue(struct clocksource *cs) { - struct list_head *tmp, *entry = &clocksource_list; - - list_for_each(tmp, &clocksource_list) { - struct clocksource *cs; + struct list_head *entry = &clocksource_list; + struct clocksource *tmp; - cs = list_entry(tmp, struct clocksource, list); - if (cs == c) - return -EBUSY; + list_for_each_entry(tmp, &clocksource_list, list) /* Keep track of the place, where to insert */ - if (cs->rating >= c->rating) - entry = tmp; - } - list_add(&c->list, entry); - - if (strlen(c->name) == strlen(override_name) && - !strcmp(c->name, override_name)) - clocksource_override = c; - - return 0; + if (tmp->rating >= cs->rating) + entry = &tmp->list; + list_add(&cs->list, entry); } /** @@ -397,19 +402,16 @@ static int clocksource_enqueue(struct clocksource *c) * * Returns -EBUSY if registration fails, zero otherwise. */ -int clocksource_register(struct clocksource *c) +int clocksource_register(struct clocksource *cs) { unsigned long flags; - int ret; spin_lock_irqsave(&clocksource_lock, flags); - ret = clocksource_enqueue(c); - if (!ret) - next_clocksource = select_clocksource(); + clocksource_enqueue(cs); + clocksource_select(); spin_unlock_irqrestore(&clocksource_lock, flags); - if (!ret) - clocksource_check_watchdog(c); - return ret; + clocksource_check_watchdog(cs); + return 0; } EXPORT_SYMBOL(clocksource_register); @@ -425,7 +427,7 @@ void clocksource_change_rating(struct clocksource *cs, int rating) list_del(&cs->list); cs->rating = rating; clocksource_enqueue(cs); - next_clocksource = select_clocksource(); + clocksource_select(); spin_unlock_irqrestore(&clocksource_lock, flags); } @@ -438,9 +440,7 @@ void clocksource_unregister(struct clocksource *cs) spin_lock_irqsave(&clocksource_lock, flags); list_del(&cs->list); - if (clocksource_override == cs) - clocksource_override = NULL; - next_clocksource = select_clocksource(); + clocksource_select(); spin_unlock_irqrestore(&clocksource_lock, flags); } @@ -478,9 +478,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, struct sysdev_attribute *attr, const char *buf, size_t count) { - struct clocksource *ovr = NULL; size_t ret = count; - int len; /* strings from sysfs write are not 0 terminated! */ if (count >= sizeof(override_name)) @@ -495,37 +493,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, if (count > 0) memcpy(override_name, buf, count); override_name[count] = 0; - - len = strlen(override_name); - if (len) { - struct clocksource *cs; - - ovr = clocksource_override; - /* try to select it: */ - list_for_each_entry(cs, &clocksource_list, list) { - if (strlen(cs->name) == len && - !strcmp(cs->name, override_name)) - ovr = cs; - } - } - - /* - * Check to make sure we don't switch to a non-highres capable - * clocksource if the tick code is in oneshot mode (highres or nohz) - */ - if (tick_oneshot_mode_active() && ovr && - !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) { - printk(KERN_WARNING "%s clocksource is not HRT compatible. " - "Cannot switch while in HRT/NOHZ mode\n", ovr->name); - ovr = NULL; - override_name[0] = 0; - } - - /* Reselect, when the override name has changed */ - if (ovr != clocksource_override) { - clocksource_override = ovr; - next_clocksource = select_clocksource(); - } + clocksource_select(); spin_unlock_irq(&clocksource_lock); diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c index c3f6c30816e3..5404a8456909 100644 --- a/kernel/time/jiffies.c +++ b/kernel/time/jiffies.c @@ -61,7 +61,6 @@ struct clocksource clocksource_jiffies = { .read = jiffies_read, .mask = 0xffffffff, /*32bits*/ .mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */ - .mult_orig = NSEC_PER_JIFFY << JIFFIES_SHIFT, .shift = JIFFIES_SHIFT, }; @@ -71,3 +70,8 @@ static int __init init_jiffies_clocksource(void) } core_initcall(init_jiffies_clocksource); + +struct clocksource * __init __weak clocksource_default_clock(void) +{ + return &clocksource_jiffies; +} diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index b5673016089f..325a9b63265a 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -269,7 +269,7 @@ static void change_clocksource(void) new = clocksource_get_next(); - if (clock == new) + if (!new || clock == new) return; clocksource_forward_now(); @@ -446,7 +446,7 @@ void __init timekeeping_init(void) ntp_init(); - clock = clocksource_get_next(); + clock = clocksource_default_clock(); if (clock->enable) clock->enable(clock); /* set mult_orig on enable */ -- cgit v1.2.2 From 8cf4e750f8459d51c2e8a035a201da4bf7aa996a Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:22 +0200 Subject: clocksource: Delay clocksource watchdog highres enablement The clocksource watchdog marks a clock as highres capable before it checked the deviation from the watchdog clocksource even for a single time. Make sure that the deviation is at least checked once before doing the switch to highres mode. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134808.627795883@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 47 ++++++++++++++++++++++------------------------- 1 file changed, 22 insertions(+), 25 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index e91662e87cde..76256c5aecb8 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -153,11 +153,8 @@ static unsigned long watchdog_resumed; #define WATCHDOG_INTERVAL (HZ >> 1) #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) -static void clocksource_ratewd(struct clocksource *cs, int64_t delta) +static void clocksource_unstable(struct clocksource *cs, int64_t delta) { - if (delta > -WATCHDOG_THRESHOLD && delta < WATCHDOG_THRESHOLD) - return; - printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n", cs->name, delta); cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); @@ -183,31 +180,31 @@ static void clocksource_watchdog(unsigned long data) list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) { csnow = cs->read(cs); - if (unlikely(resumed)) { + /* Clocksource initialized ? */ + if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) { + cs->flags |= CLOCK_SOURCE_WATCHDOG; cs->wd_last = csnow; continue; } - /* Initialized ? */ - if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) { - if ((cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) && - (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) { - cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; - /* - * We just marked the clocksource as - * highres-capable, notify the rest of the - * system as well so that we transition - * into high-res mode: - */ - tick_clock_notify(); - } - cs->flags |= CLOCK_SOURCE_WATCHDOG; - cs->wd_last = csnow; - } else { - cs_nsec = cyc2ns(cs, (csnow - cs->wd_last) & cs->mask); - cs->wd_last = csnow; - /* Check the delta. Might remove from the list ! */ - clocksource_ratewd(cs, cs_nsec - wd_nsec); + /* Check the deviation from the watchdog clocksource. */ + cs_nsec = cyc2ns(cs, (csnow - cs->wd_last) & cs->mask); + cs->wd_last = csnow; + if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) { + clocksource_unstable(cs, cs_nsec - wd_nsec); + continue; + } + + if (!(cs->flags & CLOCK_SOURCE_VALID_FOR_HRES) && + (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) && + (watchdog->flags & CLOCK_SOURCE_IS_CONTINUOUS)) { + cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; + /* + * We just marked the clocksource as highres-capable, + * notify the rest of the system as well so that we + * transition into high-res mode: + */ + tick_clock_notify(); } } -- cgit v1.2.2 From 0f8e8ef7c204988246da5a42d576b7fa5277a8e4 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:23 +0200 Subject: clocksource: Simplify clocksource watchdog resume logic To resume the clocksource watchdog just remove the CLOCK_SOURCE_WATCHDOG bit from the watched clocksource. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134808.880925790@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 76256c5aecb8..89a7b91bfbdd 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -145,7 +145,6 @@ static struct clocksource *watchdog; static struct timer_list watchdog_timer; static DEFINE_SPINLOCK(watchdog_lock); static cycle_t watchdog_last; -static unsigned long watchdog_resumed; /* * Interval: 0.5sec Threshold: 0.0625s @@ -167,12 +166,9 @@ static void clocksource_watchdog(unsigned long data) struct clocksource *cs, *tmp; cycle_t csnow, wdnow; int64_t wd_nsec, cs_nsec; - int resumed; spin_lock(&watchdog_lock); - resumed = test_and_clear_bit(0, &watchdog_resumed); - wdnow = watchdog->read(watchdog); wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask); watchdog_last = wdnow; @@ -223,14 +219,26 @@ static void clocksource_watchdog(unsigned long data) } spin_unlock(&watchdog_lock); } + +static inline void clocksource_reset_watchdog(void) +{ + struct clocksource *cs; + + list_for_each_entry(cs, &watchdog_list, wd_list) + cs->flags &= ~CLOCK_SOURCE_WATCHDOG; +} + static void clocksource_resume_watchdog(void) { - set_bit(0, &watchdog_resumed); + unsigned long flags; + + spin_lock_irqsave(&watchdog_lock, flags); + clocksource_reset_watchdog(); + spin_unlock_irqrestore(&watchdog_lock, flags); } static void clocksource_check_watchdog(struct clocksource *cs) { - struct clocksource *cse; unsigned long flags; spin_lock_irqsave(&watchdog_lock, flags); @@ -256,8 +264,7 @@ static void clocksource_check_watchdog(struct clocksource *cs) watchdog_timer.function = clocksource_watchdog; /* Reset watchdog cycles */ - list_for_each_entry(cse, &watchdog_list, wd_list) - cse->flags &= ~CLOCK_SOURCE_WATCHDOG; + clocksource_reset_watchdog(); /* Start if list is not empty */ if (!list_empty(&watchdog_list)) { watchdog_last = watchdog->read(watchdog); -- cgit v1.2.2 From fb63a0ebe615fba9de8c75ea44ded999d1e24c65 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:24 +0200 Subject: clocksource: Refactor clocksource watchdog Refactor clocksource watchdog code to make it more readable. Add clocksource_dequeue_watchdog to remove a clocksource from the watchdog list when it is unregistered. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134809.110881699@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 97 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 69 insertions(+), 28 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 89a7b91bfbdd..56aaa749645d 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -145,6 +145,7 @@ static struct clocksource *watchdog; static struct timer_list watchdog_timer; static DEFINE_SPINLOCK(watchdog_lock); static cycle_t watchdog_last; +static int watchdog_running; /* * Interval: 0.5sec Threshold: 0.0625s @@ -168,6 +169,8 @@ static void clocksource_watchdog(unsigned long data) int64_t wd_nsec, cs_nsec; spin_lock(&watchdog_lock); + if (!watchdog_running) + goto out; wdnow = watchdog->read(watchdog); wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask); @@ -217,9 +220,30 @@ static void clocksource_watchdog(unsigned long data) watchdog_timer.expires += WATCHDOG_INTERVAL; add_timer_on(&watchdog_timer, next_cpu); } +out: spin_unlock(&watchdog_lock); } +static inline void clocksource_start_watchdog(void) +{ + if (watchdog_running || !watchdog || list_empty(&watchdog_list)) + return; + init_timer(&watchdog_timer); + watchdog_timer.function = clocksource_watchdog; + watchdog_last = watchdog->read(watchdog); + watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; + add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask)); + watchdog_running = 1; +} + +static inline void clocksource_stop_watchdog(void) +{ + if (!watchdog_running || (watchdog && !list_empty(&watchdog_list))) + return; + del_timer(&watchdog_timer); + watchdog_running = 0; +} + static inline void clocksource_reset_watchdog(void) { struct clocksource *cs; @@ -237,55 +261,70 @@ static void clocksource_resume_watchdog(void) spin_unlock_irqrestore(&watchdog_lock, flags); } -static void clocksource_check_watchdog(struct clocksource *cs) +static void clocksource_enqueue_watchdog(struct clocksource *cs) { unsigned long flags; spin_lock_irqsave(&watchdog_lock, flags); if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) { - int started = !list_empty(&watchdog_list); - + /* cs is a clocksource to be watched. */ list_add(&cs->wd_list, &watchdog_list); - if (!started && watchdog) { - watchdog_last = watchdog->read(watchdog); - watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL; - add_timer_on(&watchdog_timer, - cpumask_first(cpu_online_mask)); - } + cs->flags &= ~CLOCK_SOURCE_WATCHDOG; } else { + /* cs is a watchdog. */ if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; - + /* Pick the best watchdog. */ if (!watchdog || cs->rating > watchdog->rating) { - if (watchdog) - del_timer(&watchdog_timer); watchdog = cs; - init_timer(&watchdog_timer); - watchdog_timer.function = clocksource_watchdog; - /* Reset watchdog cycles */ clocksource_reset_watchdog(); - /* Start if list is not empty */ - if (!list_empty(&watchdog_list)) { - watchdog_last = watchdog->read(watchdog); - watchdog_timer.expires = - jiffies + WATCHDOG_INTERVAL; - add_timer_on(&watchdog_timer, - cpumask_first(cpu_online_mask)); - } } } + /* Check if the watchdog timer needs to be started. */ + clocksource_start_watchdog(); spin_unlock_irqrestore(&watchdog_lock, flags); } -#else -static void clocksource_check_watchdog(struct clocksource *cs) + +static void clocksource_dequeue_watchdog(struct clocksource *cs) +{ + struct clocksource *tmp; + unsigned long flags; + + spin_lock_irqsave(&watchdog_lock, flags); + if (cs->flags & CLOCK_SOURCE_MUST_VERIFY) { + /* cs is a watched clocksource. */ + list_del_init(&cs->wd_list); + } else if (cs == watchdog) { + /* Reset watchdog cycles */ + clocksource_reset_watchdog(); + /* Current watchdog is removed. Find an alternative. */ + watchdog = NULL; + list_for_each_entry(tmp, &clocksource_list, list) { + if (tmp == cs || tmp->flags & CLOCK_SOURCE_MUST_VERIFY) + continue; + if (!watchdog || tmp->rating > watchdog->rating) + watchdog = tmp; + } + } + cs->flags &= ~CLOCK_SOURCE_WATCHDOG; + /* Check if the watchdog timer needs to be stopped. */ + clocksource_stop_watchdog(); + spin_unlock_irqrestore(&watchdog_lock, flags); +} + +#else /* CONFIG_CLOCKSOURCE_WATCHDOG */ + +static void clocksource_enqueue_watchdog(struct clocksource *cs) { if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES; } +static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { } static inline void clocksource_resume_watchdog(void) { } -#endif + +#endif /* CONFIG_CLOCKSOURCE_WATCHDOG */ /** * clocksource_resume - resume the clocksource(s) @@ -414,14 +453,13 @@ int clocksource_register(struct clocksource *cs) clocksource_enqueue(cs); clocksource_select(); spin_unlock_irqrestore(&clocksource_lock, flags); - clocksource_check_watchdog(cs); + clocksource_enqueue_watchdog(cs); return 0; } EXPORT_SYMBOL(clocksource_register); /** * clocksource_change_rating - Change the rating of a registered clocksource - * */ void clocksource_change_rating(struct clocksource *cs, int rating) { @@ -434,6 +472,7 @@ void clocksource_change_rating(struct clocksource *cs, int rating) clocksource_select(); spin_unlock_irqrestore(&clocksource_lock, flags); } +EXPORT_SYMBOL(clocksource_change_rating); /** * clocksource_unregister - remove a registered clocksource @@ -442,11 +481,13 @@ void clocksource_unregister(struct clocksource *cs) { unsigned long flags; + clocksource_dequeue_watchdog(cs); spin_lock_irqsave(&clocksource_lock, flags); list_del(&cs->list); clocksource_select(); spin_unlock_irqrestore(&clocksource_lock, flags); } +EXPORT_SYMBOL(clocksource_unregister); #ifdef CONFIG_SYSFS /** -- cgit v1.2.2 From c55c87c892c1875deace0c8fc28787335277fdf2 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:25 +0200 Subject: clocksource: Move watchdog downgrade to a work queue thread Move the downgrade of an unstable clocksource from the timer interrupt context into the process context of a work queue thread. This is needed to be able to do the clocksource switch with stop_machine. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134809.354926067@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 56 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 39 insertions(+), 17 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 56aaa749645d..f1508019bfb4 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -143,10 +143,13 @@ fs_initcall(clocksource_done_booting); static LIST_HEAD(watchdog_list); static struct clocksource *watchdog; static struct timer_list watchdog_timer; +static struct work_struct watchdog_work; static DEFINE_SPINLOCK(watchdog_lock); static cycle_t watchdog_last; static int watchdog_running; +static void clocksource_watchdog_work(struct work_struct *work); + /* * Interval: 0.5sec Threshold: 0.0625s */ @@ -158,15 +161,16 @@ static void clocksource_unstable(struct clocksource *cs, int64_t delta) printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n", cs->name, delta); cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); - clocksource_change_rating(cs, 0); - list_del(&cs->wd_list); + cs->flags |= CLOCK_SOURCE_UNSTABLE; + schedule_work(&watchdog_work); } static void clocksource_watchdog(unsigned long data) { - struct clocksource *cs, *tmp; + struct clocksource *cs; cycle_t csnow, wdnow; int64_t wd_nsec, cs_nsec; + int next_cpu; spin_lock(&watchdog_lock); if (!watchdog_running) @@ -176,7 +180,12 @@ static void clocksource_watchdog(unsigned long data) wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask); watchdog_last = wdnow; - list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) { + list_for_each_entry(cs, &watchdog_list, wd_list) { + + /* Clocksource already marked unstable? */ + if (cs->flags & CLOCK_SOURCE_UNSTABLE) + continue; + csnow = cs->read(cs); /* Clocksource initialized ? */ @@ -207,19 +216,15 @@ static void clocksource_watchdog(unsigned long data) } } - if (!list_empty(&watchdog_list)) { - /* - * Cycle through CPUs to check if the CPUs stay - * synchronized to each other. - */ - int next_cpu = cpumask_next(raw_smp_processor_id(), - cpu_online_mask); - - if (next_cpu >= nr_cpu_ids) - next_cpu = cpumask_first(cpu_online_mask); - watchdog_timer.expires += WATCHDOG_INTERVAL; - add_timer_on(&watchdog_timer, next_cpu); - } + /* + * Cycle through CPUs to check if the CPUs stay synchronized + * to each other. + */ + next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask); + if (next_cpu >= nr_cpu_ids) + next_cpu = cpumask_first(cpu_online_mask); + watchdog_timer.expires += WATCHDOG_INTERVAL; + add_timer_on(&watchdog_timer, next_cpu); out: spin_unlock(&watchdog_lock); } @@ -228,6 +233,7 @@ static inline void clocksource_start_watchdog(void) { if (watchdog_running || !watchdog || list_empty(&watchdog_list)) return; + INIT_WORK(&watchdog_work, clocksource_watchdog_work); init_timer(&watchdog_timer); watchdog_timer.function = clocksource_watchdog; watchdog_last = watchdog->read(watchdog); @@ -313,6 +319,22 @@ static void clocksource_dequeue_watchdog(struct clocksource *cs) spin_unlock_irqrestore(&watchdog_lock, flags); } +static void clocksource_watchdog_work(struct work_struct *work) +{ + struct clocksource *cs, *tmp; + unsigned long flags; + + spin_lock_irqsave(&watchdog_lock, flags); + list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) + if (cs->flags & CLOCK_SOURCE_UNSTABLE) { + list_del_init(&cs->wd_list); + clocksource_change_rating(cs, 0); + } + /* Check if the watchdog timer needs to be stopped. */ + clocksource_stop_watchdog(); + spin_unlock(&watchdog_lock); +} + #else /* CONFIG_CLOCKSOURCE_WATCHDOG */ static void clocksource_enqueue_watchdog(struct clocksource *cs) -- cgit v1.2.2 From 155ec60226ae0ae2aadaa57c951a58a359331030 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:26 +0200 Subject: timekeeping: Introduce struct timekeeper Add struct timekeeper to keep the internal values timekeeping.c needs in regard to the currently selected clock source. This moves the timekeeping intervals, xtime_nsec and the ntp error value from struct clocksource to struct timekeeper. The raw_time is removed from the clocksource as well. It gets treated like xtime as a global variable. Eventually xtime raw_time should be moved to struct timekeeper. [ tglx: minor cleanup ] Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134809.613209842@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 6 +- kernel/time/timekeeping.c | 235 ++++++++++++++++++++++++++++++---------------- 2 files changed, 160 insertions(+), 81 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index f1508019bfb4..f18c9a6bdcf4 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -177,7 +177,8 @@ static void clocksource_watchdog(unsigned long data) goto out; wdnow = watchdog->read(watchdog); - wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask); + wd_nsec = clocksource_cyc2ns((wdnow - watchdog_last) & watchdog->mask, + watchdog->mult, watchdog->shift); watchdog_last = wdnow; list_for_each_entry(cs, &watchdog_list, wd_list) { @@ -196,7 +197,8 @@ static void clocksource_watchdog(unsigned long data) } /* Check the deviation from the watchdog clocksource. */ - cs_nsec = cyc2ns(cs, (csnow - cs->wd_last) & cs->mask); + cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) & + cs->mask, cs->mult, cs->shift); cs->wd_last = csnow; if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) { clocksource_unstable(cs, cs_nsec - wd_nsec); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 325a9b63265a..7af45cbf6b13 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -19,6 +19,65 @@ #include #include +/* Structure holding internal timekeeping values. */ +struct timekeeper { + /* Current clocksource used for timekeeping. */ + struct clocksource *clock; + + /* Number of clock cycles in one NTP interval. */ + cycle_t cycle_interval; + /* Number of clock shifted nano seconds in one NTP interval. */ + u64 xtime_interval; + /* Raw nano seconds accumulated per NTP interval. */ + u32 raw_interval; + + /* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */ + u64 xtime_nsec; + /* Difference between accumulated time and NTP time in ntp + * shifted nano seconds. */ + s64 ntp_error; +}; + +struct timekeeper timekeeper; + +/** + * timekeeper_setup_internals - Set up internals to use clocksource clock. + * + * @clock: Pointer to clocksource. + * + * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment + * pair and interval request. + * + * Unless you're the timekeeping code, you should not be using this! + */ +static void timekeeper_setup_internals(struct clocksource *clock) +{ + cycle_t interval; + u64 tmp; + + timekeeper.clock = clock; + clock->cycle_last = clock->read(clock); + + /* Do the ns -> cycle conversion first, using original mult */ + tmp = NTP_INTERVAL_LENGTH; + tmp <<= clock->shift; + tmp += clock->mult_orig/2; + do_div(tmp, clock->mult_orig); + if (tmp == 0) + tmp = 1; + + interval = (cycle_t) tmp; + timekeeper.cycle_interval = interval; + + /* Go back from cycles -> shifted ns */ + timekeeper.xtime_interval = (u64) interval * clock->mult; + timekeeper.raw_interval = + ((u64) interval * clock->mult_orig) >> clock->shift; + + timekeeper.xtime_nsec = 0; + + timekeeper.ntp_error = 0; +} /* * This read-write spinlock protects us from races in SMP while @@ -46,6 +105,11 @@ struct timespec xtime __attribute__ ((aligned (16))); struct timespec wall_to_monotonic __attribute__ ((aligned (16))); static unsigned long total_sleep_time; /* seconds */ +/* + * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. + */ +struct timespec raw_time; + /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; @@ -56,42 +120,42 @@ void update_xtime_cache(u64 nsec) timespec_add_ns(&xtime_cache, nsec); } -struct clocksource *clock; - /* must hold xtime_lock */ void timekeeping_leap_insert(int leapsecond) { xtime.tv_sec += leapsecond; wall_to_monotonic.tv_sec -= leapsecond; - update_vsyscall(&xtime, clock); + update_vsyscall(&xtime, timekeeper.clock); } #ifdef CONFIG_GENERIC_TIME /** - * clocksource_forward_now - update clock to the current time + * timekeeping_forward_now - update clock to the current time * * Forward the current clock to update its state since the last call to * update_wall_time(). This is useful before significant clock changes, * as it avoids having to deal with this time offset explicitly. */ -static void clocksource_forward_now(void) +static void timekeeping_forward_now(void) { cycle_t cycle_now, cycle_delta; + struct clocksource *clock; s64 nsec; + clock = timekeeper.clock; cycle_now = clock->read(clock); cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; clock->cycle_last = cycle_now; - nsec = cyc2ns(clock, cycle_delta); + nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); /* If arch requires, add in gettimeoffset() */ nsec += arch_gettimeoffset(); timespec_add_ns(&xtime, nsec); - nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift; - clock->raw_time.tv_nsec += nsec; + nsec = clocksource_cyc2ns(cycle_delta, clock->mult_orig, clock->shift); + timespec_add_ns(&raw_time, nsec); } /** @@ -103,6 +167,7 @@ static void clocksource_forward_now(void) void getnstimeofday(struct timespec *ts) { cycle_t cycle_now, cycle_delta; + struct clocksource *clock; unsigned long seq; s64 nsecs; @@ -114,13 +179,15 @@ void getnstimeofday(struct timespec *ts) *ts = xtime; /* read clocksource: */ + clock = timekeeper.clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs = cyc2ns(clock, cycle_delta); + nsecs = clocksource_cyc2ns(cycle_delta, clock->mult, + clock->shift); /* If arch requires, add in gettimeoffset() */ nsecs += arch_gettimeoffset(); @@ -135,6 +202,7 @@ EXPORT_SYMBOL(getnstimeofday); ktime_t ktime_get(void) { cycle_t cycle_now, cycle_delta; + struct clocksource *clock; unsigned int seq; s64 secs, nsecs; @@ -146,13 +214,15 @@ ktime_t ktime_get(void) nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; /* read clocksource: */ + clock = timekeeper.clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs += cyc2ns(clock, cycle_delta); + nsecs += clocksource_cyc2ns(cycle_delta, clock->mult, + clock->shift); } while (read_seqretry(&xtime_lock, seq)); /* @@ -174,6 +244,7 @@ EXPORT_SYMBOL_GPL(ktime_get); void ktime_get_ts(struct timespec *ts) { cycle_t cycle_now, cycle_delta; + struct clocksource *clock; struct timespec tomono; unsigned int seq; s64 nsecs; @@ -186,13 +257,15 @@ void ktime_get_ts(struct timespec *ts) tomono = wall_to_monotonic; /* read clocksource: */ + clock = timekeeper.clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs = cyc2ns(clock, cycle_delta); + nsecs = clocksource_cyc2ns(cycle_delta, clock->mult, + clock->shift); } while (read_seqretry(&xtime_lock, seq)); @@ -233,7 +306,7 @@ int do_settimeofday(struct timespec *tv) write_seqlock_irqsave(&xtime_lock, flags); - clocksource_forward_now(); + timekeeping_forward_now(); ts_delta.tv_sec = tv->tv_sec - xtime.tv_sec; ts_delta.tv_nsec = tv->tv_nsec - xtime.tv_nsec; @@ -243,10 +316,10 @@ int do_settimeofday(struct timespec *tv) update_xtime_cache(0); - clock->error = 0; + timekeeper.ntp_error = 0; ntp_clear(); - update_vsyscall(&xtime, clock); + update_vsyscall(&xtime, timekeeper.clock); write_sequnlock_irqrestore(&xtime_lock, flags); @@ -269,10 +342,10 @@ static void change_clocksource(void) new = clocksource_get_next(); - if (!new || clock == new) + if (!new || timekeeper.clock == new) return; - clocksource_forward_now(); + timekeeping_forward_now(); if (new->enable && !new->enable(new)) return; @@ -284,9 +357,9 @@ static void change_clocksource(void) */ new->mult_orig = new->mult; - new->raw_time = clock->raw_time; - old = clock; - clock = new; + old = timekeeper.clock; + timekeeper_setup_internals(new); + /* * Save mult_orig in mult so that the value can be restored * regardless if ->enable() updates the value of mult or not. @@ -295,22 +368,10 @@ static void change_clocksource(void) if (old->disable) old->disable(old); - clock->cycle_last = clock->read(clock); - clock->error = 0; - clock->xtime_nsec = 0; - clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); - tick_clock_notify(); - - /* - * We're holding xtime lock and waking up klogd would deadlock - * us on enqueue. So no printing! - printk(KERN_INFO "Time: %s clocksource has been installed.\n", - clock->name); - */ } #else /* GENERIC_TIME */ -static inline void clocksource_forward_now(void) { } +static inline void timekeeping_forward_now(void) { } static inline void change_clocksource(void) { } /** @@ -380,20 +441,23 @@ void getrawmonotonic(struct timespec *ts) unsigned long seq; s64 nsecs; cycle_t cycle_now, cycle_delta; + struct clocksource *clock; do { seq = read_seqbegin(&xtime_lock); /* read clocksource: */ + clock = timekeeper.clock; cycle_now = clock->read(clock); /* calculate the delta since the last update_wall_time: */ cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs = ((s64)cycle_delta * clock->mult_orig) >> clock->shift; + nsecs = clocksource_cyc2ns(cycle_delta, clock->mult_orig, + clock->shift); - *ts = clock->raw_time; + *ts = raw_time; } while (read_seqretry(&xtime_lock, seq)); @@ -413,7 +477,7 @@ int timekeeping_valid_for_hres(void) do { seq = read_seqbegin(&xtime_lock); - ret = clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; + ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES; } while (read_seqretry(&xtime_lock, seq)); @@ -439,6 +503,7 @@ unsigned long __attribute__((weak)) read_persistent_clock(void) */ void __init timekeeping_init(void) { + struct clocksource *clock; unsigned long flags; unsigned long sec = read_persistent_clock(); @@ -451,11 +516,13 @@ void __init timekeeping_init(void) clock->enable(clock); /* set mult_orig on enable */ clock->mult_orig = clock->mult; - clocksource_calculate_interval(clock, NTP_INTERVAL_LENGTH); - clock->cycle_last = clock->read(clock); + + timekeeper_setup_internals(clock); xtime.tv_sec = sec; xtime.tv_nsec = 0; + raw_time.tv_sec = 0; + raw_time.tv_nsec = 0; set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); update_xtime_cache(0); @@ -492,8 +559,8 @@ static int timekeeping_resume(struct sys_device *dev) } update_xtime_cache(0); /* re-base the last cycle value */ - clock->cycle_last = clock->read(clock); - clock->error = 0; + timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock); + timekeeper.ntp_error = 0; timekeeping_suspended = 0; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -514,7 +581,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) timekeeping_suspend_time = read_persistent_clock(); write_seqlock_irqsave(&xtime_lock, flags); - clocksource_forward_now(); + timekeeping_forward_now(); timekeeping_suspended = 1; write_sequnlock_irqrestore(&xtime_lock, flags); @@ -549,7 +616,7 @@ device_initcall(timekeeping_init_device); * If the error is already larger, we look ahead even further * to compensate for late or lost adjustments. */ -static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, +static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, s64 *offset) { s64 tick_error, i; @@ -565,7 +632,7 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, * here. This is tuned so that an error of about 1 msec is adjusted * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks). */ - error2 = clock->error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); + error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ); error2 = abs(error2); for (look_ahead = 0; error2 > 0; look_ahead++) error2 >>= 2; @@ -574,8 +641,9 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, * Now calculate the error in (1 << look_ahead) ticks, but first * remove the single look ahead already included in the error. */ - tick_error = tick_length >> (NTP_SCALE_SHIFT - clock->shift + 1); - tick_error -= clock->xtime_interval >> 1; + tick_error = tick_length >> + (NTP_SCALE_SHIFT - timekeeper.clock->shift + 1); + tick_error -= timekeeper.xtime_interval >> 1; error = ((error - tick_error) >> look_ahead) + tick_error; /* Finally calculate the adjustment shift value. */ @@ -600,18 +668,19 @@ static __always_inline int clocksource_bigadjust(s64 error, s64 *interval, * this is optimized for the most common adjustments of -1,0,1, * for other values we can do a bit more work. */ -static void clocksource_adjust(s64 offset) +static void timekeeping_adjust(s64 offset) { - s64 error, interval = clock->cycle_interval; + s64 error, interval = timekeeper.cycle_interval; int adj; - error = clock->error >> (NTP_SCALE_SHIFT - clock->shift - 1); + error = timekeeper.ntp_error >> + (NTP_SCALE_SHIFT - timekeeper.clock->shift - 1); if (error > interval) { error >>= 2; if (likely(error <= interval)) adj = 1; else - adj = clocksource_bigadjust(error, &interval, &offset); + adj = timekeeping_bigadjust(error, &interval, &offset); } else if (error < -interval) { error >>= 2; if (likely(error >= -interval)) { @@ -619,15 +688,15 @@ static void clocksource_adjust(s64 offset) interval = -interval; offset = -offset; } else - adj = clocksource_bigadjust(error, &interval, &offset); + adj = timekeeping_bigadjust(error, &interval, &offset); } else return; - clock->mult += adj; - clock->xtime_interval += interval; - clock->xtime_nsec -= offset; - clock->error -= (interval - offset) << - (NTP_SCALE_SHIFT - clock->shift); + timekeeper.clock->mult += adj; + timekeeper.xtime_interval += interval; + timekeeper.xtime_nsec -= offset; + timekeeper.ntp_error -= (interval - offset) << + (NTP_SCALE_SHIFT - timekeeper.clock->shift); } /** @@ -637,53 +706,59 @@ static void clocksource_adjust(s64 offset) */ void update_wall_time(void) { + struct clocksource *clock; cycle_t offset; + s64 nsecs; /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) return; + clock = timekeeper.clock; #ifdef CONFIG_GENERIC_TIME offset = (clock->read(clock) - clock->cycle_last) & clock->mask; #else - offset = clock->cycle_interval; + offset = timekeeper.cycle_interval; #endif - clock->xtime_nsec = (s64)xtime.tv_nsec << clock->shift; + timekeeper.xtime_nsec = (s64)xtime.tv_nsec << clock->shift; /* normally this loop will run just once, however in the * case of lost or late ticks, it will accumulate correctly. */ - while (offset >= clock->cycle_interval) { + while (offset >= timekeeper.cycle_interval) { + u64 nsecps = (u64)NSEC_PER_SEC << clock->shift; + /* accumulate one interval */ - offset -= clock->cycle_interval; - clock->cycle_last += clock->cycle_interval; + offset -= timekeeper.cycle_interval; + clock->cycle_last += timekeeper.cycle_interval; - clock->xtime_nsec += clock->xtime_interval; - if (clock->xtime_nsec >= (u64)NSEC_PER_SEC << clock->shift) { - clock->xtime_nsec -= (u64)NSEC_PER_SEC << clock->shift; + timekeeper.xtime_nsec += timekeeper.xtime_interval; + if (timekeeper.xtime_nsec >= nsecps) { + timekeeper.xtime_nsec -= nsecps; xtime.tv_sec++; second_overflow(); } - clock->raw_time.tv_nsec += clock->raw_interval; - if (clock->raw_time.tv_nsec >= NSEC_PER_SEC) { - clock->raw_time.tv_nsec -= NSEC_PER_SEC; - clock->raw_time.tv_sec++; + raw_time.tv_nsec += timekeeper.raw_interval; + if (raw_time.tv_nsec >= NSEC_PER_SEC) { + raw_time.tv_nsec -= NSEC_PER_SEC; + raw_time.tv_sec++; } /* accumulate error between NTP and clock interval */ - clock->error += tick_length; - clock->error -= clock->xtime_interval << (NTP_SCALE_SHIFT - clock->shift); + timekeeper.ntp_error += tick_length; + timekeeper.ntp_error -= timekeeper.xtime_interval << + (NTP_SCALE_SHIFT - clock->shift); } /* correct the clock when NTP error is too big */ - clocksource_adjust(offset); + timekeeping_adjust(offset); /* * Since in the loop above, we accumulate any amount of time * in xtime_nsec over a second into xtime.tv_sec, its possible for * xtime_nsec to be fairly small after the loop. Further, if we're - * slightly speeding the clocksource up in clocksource_adjust(), + * slightly speeding the clocksource up in timekeeping_adjust(), * its possible the required corrective factor to xtime_nsec could * cause it to underflow. * @@ -695,24 +770,26 @@ void update_wall_time(void) * We'll correct this error next time through this function, when * xtime_nsec is not as small. */ - if (unlikely((s64)clock->xtime_nsec < 0)) { - s64 neg = -(s64)clock->xtime_nsec; - clock->xtime_nsec = 0; - clock->error += neg << (NTP_SCALE_SHIFT - clock->shift); + if (unlikely((s64)timekeeper.xtime_nsec < 0)) { + s64 neg = -(s64)timekeeper.xtime_nsec; + timekeeper.xtime_nsec = 0; + timekeeper.ntp_error += neg << (NTP_SCALE_SHIFT - clock->shift); } /* store full nanoseconds into xtime after rounding it up and * add the remainder to the error difference. */ - xtime.tv_nsec = ((s64)clock->xtime_nsec >> clock->shift) + 1; - clock->xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; - clock->error += clock->xtime_nsec << (NTP_SCALE_SHIFT - clock->shift); + xtime.tv_nsec = ((s64)timekeeper.xtime_nsec >> clock->shift) + 1; + timekeeper.xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; + timekeeper.ntp_error += timekeeper.xtime_nsec << + (NTP_SCALE_SHIFT - clock->shift); - update_xtime_cache(cyc2ns(clock, offset)); + nsecs = clocksource_cyc2ns(offset, clock->mult, clock->shift); + update_xtime_cache(nsecs); /* check to see if there is a new clocksource to use */ change_clocksource(); - update_vsyscall(&xtime, clock); + update_vsyscall(&xtime, timekeeper.clock); } /** -- cgit v1.2.2 From 23ce72117c714baab794e66c8daf343bf6a912bf Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:27 +0200 Subject: timekeeping: Add xtime_shift and ntp_error_shift to struct timekeeper The xtime_nsec value in the timekeeper structure is shifted by a few bits to improve precision. This happens to be the same value as the clock->shift. To improve readability add xtime_shift to the timekeeper and use it instead of the clock->shift. Likewise add ntp_error_shift and replace all (NTP_SCALE_SHIFT - clock->shift) expressions. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134809.871899606@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 7af45cbf6b13..dfdab1cefe1e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -23,6 +23,8 @@ struct timekeeper { /* Current clocksource used for timekeeping. */ struct clocksource *clock; + /* The shift value of the current clocksource. */ + int shift; /* Number of clock cycles in one NTP interval. */ cycle_t cycle_interval; @@ -36,6 +38,9 @@ struct timekeeper { /* Difference between accumulated time and NTP time in ntp * shifted nano seconds. */ s64 ntp_error; + /* Shift conversion between clock shifted nano seconds and + * ntp shifted nano seconds. */ + int ntp_error_shift; }; struct timekeeper timekeeper; @@ -75,8 +80,10 @@ static void timekeeper_setup_internals(struct clocksource *clock) ((u64) interval * clock->mult_orig) >> clock->shift; timekeeper.xtime_nsec = 0; + timekeeper.shift = clock->shift; timekeeper.ntp_error = 0; + timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; } /* @@ -641,8 +648,7 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval, * Now calculate the error in (1 << look_ahead) ticks, but first * remove the single look ahead already included in the error. */ - tick_error = tick_length >> - (NTP_SCALE_SHIFT - timekeeper.clock->shift + 1); + tick_error = tick_length >> (timekeeper.ntp_error_shift + 1); tick_error -= timekeeper.xtime_interval >> 1; error = ((error - tick_error) >> look_ahead) + tick_error; @@ -673,8 +679,7 @@ static void timekeeping_adjust(s64 offset) s64 error, interval = timekeeper.cycle_interval; int adj; - error = timekeeper.ntp_error >> - (NTP_SCALE_SHIFT - timekeeper.clock->shift - 1); + error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1); if (error > interval) { error >>= 2; if (likely(error <= interval)) @@ -696,7 +701,7 @@ static void timekeeping_adjust(s64 offset) timekeeper.xtime_interval += interval; timekeeper.xtime_nsec -= offset; timekeeper.ntp_error -= (interval - offset) << - (NTP_SCALE_SHIFT - timekeeper.clock->shift); + timekeeper.ntp_error_shift; } /** @@ -708,7 +713,7 @@ void update_wall_time(void) { struct clocksource *clock; cycle_t offset; - s64 nsecs; + u64 nsecs; /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) @@ -720,13 +725,13 @@ void update_wall_time(void) #else offset = timekeeper.cycle_interval; #endif - timekeeper.xtime_nsec = (s64)xtime.tv_nsec << clock->shift; + timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; /* normally this loop will run just once, however in the * case of lost or late ticks, it will accumulate correctly. */ while (offset >= timekeeper.cycle_interval) { - u64 nsecps = (u64)NSEC_PER_SEC << clock->shift; + u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; /* accumulate one interval */ offset -= timekeeper.cycle_interval; @@ -748,7 +753,7 @@ void update_wall_time(void) /* accumulate error between NTP and clock interval */ timekeeper.ntp_error += tick_length; timekeeper.ntp_error -= timekeeper.xtime_interval << - (NTP_SCALE_SHIFT - clock->shift); + timekeeper.ntp_error_shift; } /* correct the clock when NTP error is too big */ @@ -773,16 +778,16 @@ void update_wall_time(void) if (unlikely((s64)timekeeper.xtime_nsec < 0)) { s64 neg = -(s64)timekeeper.xtime_nsec; timekeeper.xtime_nsec = 0; - timekeeper.ntp_error += neg << (NTP_SCALE_SHIFT - clock->shift); + timekeeper.ntp_error += neg << timekeeper.ntp_error_shift; } /* store full nanoseconds into xtime after rounding it up and * add the remainder to the error difference. */ - xtime.tv_nsec = ((s64)timekeeper.xtime_nsec >> clock->shift) + 1; - timekeeper.xtime_nsec -= (s64)xtime.tv_nsec << clock->shift; - timekeeper.ntp_error += timekeeper.xtime_nsec << - (NTP_SCALE_SHIFT - clock->shift); + xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1; + timekeeper.xtime_nsec -= (s64) xtime.tv_nsec << timekeeper.shift; + timekeeper.ntp_error += timekeeper.xtime_nsec << + timekeeper.ntp_error_shift; nsecs = clocksource_cyc2ns(offset, clock->mult, clock->shift); update_xtime_cache(nsecs); -- cgit v1.2.2 From 0a54419836254a27baecd9037103171bcbabaf67 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:28 +0200 Subject: timekeeping: Move NTP adjusted clock multiplier to struct timekeeper The clocksource structure has two multipliers, the unmodified multiplier clock->mult_orig and the NTP corrected multiplier clock->mult. The NTP multiplier is misplaced in the struct clocksource, this is private information of the timekeeping code. Add the mult field to the struct timekeeper to contain the NTP corrected value, keep the unmodifed multiplier in clock->mult and remove clock->mult_orig. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134810.149047645@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 53 +++++++++++++++++++++-------------------------- 1 file changed, 24 insertions(+), 29 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index dfdab1cefe1e..f4056f6c2632 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -41,6 +41,8 @@ struct timekeeper { /* Shift conversion between clock shifted nano seconds and * ntp shifted nano seconds. */ int ntp_error_shift; + /* NTP adjusted clock multiplier */ + u32 mult; }; struct timekeeper timekeeper; @@ -66,8 +68,8 @@ static void timekeeper_setup_internals(struct clocksource *clock) /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; tmp <<= clock->shift; - tmp += clock->mult_orig/2; - do_div(tmp, clock->mult_orig); + tmp += clock->mult/2; + do_div(tmp, clock->mult); if (tmp == 0) tmp = 1; @@ -77,13 +79,20 @@ static void timekeeper_setup_internals(struct clocksource *clock) /* Go back from cycles -> shifted ns */ timekeeper.xtime_interval = (u64) interval * clock->mult; timekeeper.raw_interval = - ((u64) interval * clock->mult_orig) >> clock->shift; + ((u64) interval * clock->mult) >> clock->shift; timekeeper.xtime_nsec = 0; timekeeper.shift = clock->shift; timekeeper.ntp_error = 0; timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift; + + /* + * The timekeeper keeps its own mult values for the currently + * active clocksource. These value will be adjusted via NTP + * to counteract clock drifting. + */ + timekeeper.mult = clock->mult; } /* @@ -154,14 +163,15 @@ static void timekeeping_forward_now(void) cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; clock->cycle_last = cycle_now; - nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); + nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult, + timekeeper.shift); /* If arch requires, add in gettimeoffset() */ nsec += arch_gettimeoffset(); timespec_add_ns(&xtime, nsec); - nsec = clocksource_cyc2ns(cycle_delta, clock->mult_orig, clock->shift); + nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); timespec_add_ns(&raw_time, nsec); } @@ -193,8 +203,8 @@ void getnstimeofday(struct timespec *ts) cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs = clocksource_cyc2ns(cycle_delta, clock->mult, - clock->shift); + nsecs = clocksource_cyc2ns(cycle_delta, timekeeper.mult, + timekeeper.shift); /* If arch requires, add in gettimeoffset() */ nsecs += arch_gettimeoffset(); @@ -228,8 +238,8 @@ ktime_t ktime_get(void) cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs += clocksource_cyc2ns(cycle_delta, clock->mult, - clock->shift); + nsecs += clocksource_cyc2ns(cycle_delta, timekeeper.mult, + timekeeper.shift); } while (read_seqretry(&xtime_lock, seq)); /* @@ -271,8 +281,8 @@ void ktime_get_ts(struct timespec *ts) cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs = clocksource_cyc2ns(cycle_delta, clock->mult, - clock->shift); + nsecs = clocksource_cyc2ns(cycle_delta, timekeeper.mult, + timekeeper.shift); } while (read_seqretry(&xtime_lock, seq)); @@ -356,22 +366,10 @@ static void change_clocksource(void) if (new->enable && !new->enable(new)) return; - /* - * The frequency may have changed while the clocksource - * was disabled. If so the code in ->enable() must update - * the mult value to reflect the new frequency. Make sure - * mult_orig follows this change. - */ - new->mult_orig = new->mult; old = timekeeper.clock; timekeeper_setup_internals(new); - /* - * Save mult_orig in mult so that the value can be restored - * regardless if ->enable() updates the value of mult or not. - */ - old->mult = old->mult_orig; if (old->disable) old->disable(old); @@ -461,7 +459,7 @@ void getrawmonotonic(struct timespec *ts) cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; /* convert to nanoseconds: */ - nsecs = clocksource_cyc2ns(cycle_delta, clock->mult_orig, + nsecs = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); *ts = raw_time; @@ -521,9 +519,6 @@ void __init timekeeping_init(void) clock = clocksource_default_clock(); if (clock->enable) clock->enable(clock); - /* set mult_orig on enable */ - clock->mult_orig = clock->mult; - timekeeper_setup_internals(clock); xtime.tv_sec = sec; @@ -697,7 +692,7 @@ static void timekeeping_adjust(s64 offset) } else return; - timekeeper.clock->mult += adj; + timekeeper.mult += adj; timekeeper.xtime_interval += interval; timekeeper.xtime_nsec -= offset; timekeeper.ntp_error -= (interval - offset) << @@ -789,7 +784,7 @@ void update_wall_time(void) timekeeper.ntp_error += timekeeper.xtime_nsec << timekeeper.ntp_error_shift; - nsecs = clocksource_cyc2ns(offset, clock->mult, clock->shift); + nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift); update_xtime_cache(nsecs); /* check to see if there is a new clocksource to use */ -- cgit v1.2.2 From 2ba2a3054fdffc8e6452f4ee120760322a6fbd43 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:29 +0200 Subject: timekeeping: Add timekeeper read_clock helper functions Add timekeeper_read_clock_ntp and timekeeper_read_clock_raw and use them for getnstimeofday, ktime_get, ktime_get_ts and getrawmonotonic. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134810.435105711@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 91 ++++++++++++++++++++--------------------------- 1 file changed, 38 insertions(+), 53 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index f4056f6c2632..27ae01b596b7 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -95,6 +95,40 @@ static void timekeeper_setup_internals(struct clocksource *clock) timekeeper.mult = clock->mult; } +/* Timekeeper helper functions. */ +static inline s64 timekeeping_get_ns(void) +{ + cycle_t cycle_now, cycle_delta; + struct clocksource *clock; + + /* read clocksource: */ + clock = timekeeper.clock; + cycle_now = clock->read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* return delta convert to nanoseconds using ntp adjusted mult. */ + return clocksource_cyc2ns(cycle_delta, timekeeper.mult, + timekeeper.shift); +} + +static inline s64 timekeeping_get_ns_raw(void) +{ + cycle_t cycle_now, cycle_delta; + struct clocksource *clock; + + /* read clocksource: */ + clock = timekeeper.clock; + cycle_now = clock->read(clock); + + /* calculate the delta since the last update_wall_time: */ + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; + + /* return delta convert to nanoseconds using ntp adjusted mult. */ + return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift); +} + /* * This read-write spinlock protects us from races in SMP while * playing with xtime. @@ -183,8 +217,6 @@ static void timekeeping_forward_now(void) */ void getnstimeofday(struct timespec *ts) { - cycle_t cycle_now, cycle_delta; - struct clocksource *clock; unsigned long seq; s64 nsecs; @@ -194,17 +226,7 @@ void getnstimeofday(struct timespec *ts) seq = read_seqbegin(&xtime_lock); *ts = xtime; - - /* read clocksource: */ - clock = timekeeper.clock; - cycle_now = clock->read(clock); - - /* calculate the delta since the last update_wall_time: */ - cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - - /* convert to nanoseconds: */ - nsecs = clocksource_cyc2ns(cycle_delta, timekeeper.mult, - timekeeper.shift); + nsecs = timekeeping_get_ns(); /* If arch requires, add in gettimeoffset() */ nsecs += arch_gettimeoffset(); @@ -218,8 +240,6 @@ EXPORT_SYMBOL(getnstimeofday); ktime_t ktime_get(void) { - cycle_t cycle_now, cycle_delta; - struct clocksource *clock; unsigned int seq; s64 secs, nsecs; @@ -229,17 +249,7 @@ ktime_t ktime_get(void) seq = read_seqbegin(&xtime_lock); secs = xtime.tv_sec + wall_to_monotonic.tv_sec; nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; - - /* read clocksource: */ - clock = timekeeper.clock; - cycle_now = clock->read(clock); - - /* calculate the delta since the last update_wall_time: */ - cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - - /* convert to nanoseconds: */ - nsecs += clocksource_cyc2ns(cycle_delta, timekeeper.mult, - timekeeper.shift); + nsecs += timekeeping_get_ns(); } while (read_seqretry(&xtime_lock, seq)); /* @@ -260,8 +270,6 @@ EXPORT_SYMBOL_GPL(ktime_get); */ void ktime_get_ts(struct timespec *ts) { - cycle_t cycle_now, cycle_delta; - struct clocksource *clock; struct timespec tomono; unsigned int seq; s64 nsecs; @@ -272,17 +280,7 @@ void ktime_get_ts(struct timespec *ts) seq = read_seqbegin(&xtime_lock); *ts = xtime; tomono = wall_to_monotonic; - - /* read clocksource: */ - clock = timekeeper.clock; - cycle_now = clock->read(clock); - - /* calculate the delta since the last update_wall_time: */ - cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - - /* convert to nanoseconds: */ - nsecs = clocksource_cyc2ns(cycle_delta, timekeeper.mult, - timekeeper.shift); + nsecs = timekeeping_get_ns(); } while (read_seqretry(&xtime_lock, seq)); @@ -445,23 +443,10 @@ void getrawmonotonic(struct timespec *ts) { unsigned long seq; s64 nsecs; - cycle_t cycle_now, cycle_delta; - struct clocksource *clock; do { seq = read_seqbegin(&xtime_lock); - - /* read clocksource: */ - clock = timekeeper.clock; - cycle_now = clock->read(clock); - - /* calculate the delta since the last update_wall_time: */ - cycle_delta = (cycle_now - clock->cycle_last) & clock->mask; - - /* convert to nanoseconds: */ - nsecs = clocksource_cyc2ns(cycle_delta, clock->mult, - clock->shift); - + nsecs = timekeeping_get_ns_raw(); *ts = raw_time; } while (read_seqretry(&xtime_lock, seq)); -- cgit v1.2.2 From 75c5158f70c065b9704b924503d96e8297838f79 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:30 +0200 Subject: timekeeping: Update clocksource with stop_machine update_wall_time calls change_clocksource HZ times per second to check if a new clock source is available. In close to 100% of all calls there is no new clock. Replace the tick based check by an update done with stop_machine. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134810.711836357@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 112 ++++++++++++++++++---------------------------- kernel/time/timekeeping.c | 41 ++++++++++------- 2 files changed, 70 insertions(+), 83 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index f18c9a6bdcf4..a1657b5fdeb9 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -109,35 +109,17 @@ EXPORT_SYMBOL(timecounter_cyc2time); /*[Clocksource internal variables]--------- * curr_clocksource: * currently selected clocksource. - * next_clocksource: - * pending next selected clocksource. * clocksource_list: * linked list with the registered clocksources - * clocksource_lock: - * protects manipulations to curr_clocksource and next_clocksource - * and the clocksource_list + * clocksource_mutex: + * protects manipulations to curr_clocksource and the clocksource_list * override_name: * Name of the user-specified clocksource. */ static struct clocksource *curr_clocksource; -static struct clocksource *next_clocksource; static LIST_HEAD(clocksource_list); -static DEFINE_SPINLOCK(clocksource_lock); +static DEFINE_MUTEX(clocksource_mutex); static char override_name[32]; -static int finished_booting; - -/* clocksource_done_booting - Called near the end of core bootup - * - * Hack to avoid lots of clocksource churn at boot time. - * We use fs_initcall because we want this to start before - * device_initcall but after subsys_initcall. - */ -static int __init clocksource_done_booting(void) -{ - finished_booting = 1; - return 0; -} -fs_initcall(clocksource_done_booting); #ifdef CONFIG_CLOCKSOURCE_WATCHDOG static LIST_HEAD(watchdog_list); @@ -356,18 +338,16 @@ static inline void clocksource_resume_watchdog(void) { } void clocksource_resume(void) { struct clocksource *cs; - unsigned long flags; - spin_lock_irqsave(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); - list_for_each_entry(cs, &clocksource_list, list) { + list_for_each_entry(cs, &clocksource_list, list) if (cs->resume) cs->resume(); - } clocksource_resume_watchdog(); - spin_unlock_irqrestore(&clocksource_lock, flags); + mutex_unlock(&clocksource_mutex); } /** @@ -383,28 +363,13 @@ void clocksource_touch_watchdog(void) } #ifdef CONFIG_GENERIC_TIME -/** - * clocksource_get_next - Returns the selected clocksource - * - */ -struct clocksource *clocksource_get_next(void) -{ - unsigned long flags; - spin_lock_irqsave(&clocksource_lock, flags); - if (next_clocksource && finished_booting) { - curr_clocksource = next_clocksource; - next_clocksource = NULL; - } - spin_unlock_irqrestore(&clocksource_lock, flags); - - return curr_clocksource; -} +static int finished_booting; /** * clocksource_select - Select the best clocksource available * - * Private function. Must hold clocksource_lock when called. + * Private function. Must hold clocksource_mutex when called. * * Select the clocksource with the best rating, or the clocksource, * which is selected by userspace override. @@ -413,7 +378,7 @@ static void clocksource_select(void) { struct clocksource *best, *cs; - if (list_empty(&clocksource_list)) + if (!finished_booting || list_empty(&clocksource_list)) return; /* First clocksource on the list has the best rating. */ best = list_first_entry(&clocksource_list, struct clocksource, list); @@ -438,13 +403,31 @@ static void clocksource_select(void) best = cs; break; } - if (curr_clocksource != best) - next_clocksource = best; + if (curr_clocksource != best) { + printk(KERN_INFO "Switching to clocksource %s\n", best->name); + curr_clocksource = best; + timekeeping_notify(curr_clocksource); + } } +/* + * clocksource_done_booting - Called near the end of core bootup + * + * Hack to avoid lots of clocksource churn at boot time. + * We use fs_initcall because we want this to start before + * device_initcall but after subsys_initcall. + */ +static int __init clocksource_done_booting(void) +{ + finished_booting = 1; + clocksource_select(); + return 0; +} +fs_initcall(clocksource_done_booting); + #else /* CONFIG_GENERIC_TIME */ -static void clocksource_select(void) { } +static inline void clocksource_select(void) { } #endif @@ -471,13 +454,11 @@ static void clocksource_enqueue(struct clocksource *cs) */ int clocksource_register(struct clocksource *cs) { - unsigned long flags; - - spin_lock_irqsave(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); clocksource_select(); - spin_unlock_irqrestore(&clocksource_lock, flags); clocksource_enqueue_watchdog(cs); + mutex_unlock(&clocksource_mutex); return 0; } EXPORT_SYMBOL(clocksource_register); @@ -487,14 +468,12 @@ EXPORT_SYMBOL(clocksource_register); */ void clocksource_change_rating(struct clocksource *cs, int rating) { - unsigned long flags; - - spin_lock_irqsave(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); list_del(&cs->list); cs->rating = rating; clocksource_enqueue(cs); clocksource_select(); - spin_unlock_irqrestore(&clocksource_lock, flags); + mutex_unlock(&clocksource_mutex); } EXPORT_SYMBOL(clocksource_change_rating); @@ -503,13 +482,11 @@ EXPORT_SYMBOL(clocksource_change_rating); */ void clocksource_unregister(struct clocksource *cs) { - unsigned long flags; - + mutex_lock(&clocksource_mutex); clocksource_dequeue_watchdog(cs); - spin_lock_irqsave(&clocksource_lock, flags); list_del(&cs->list); clocksource_select(); - spin_unlock_irqrestore(&clocksource_lock, flags); + mutex_unlock(&clocksource_mutex); } EXPORT_SYMBOL(clocksource_unregister); @@ -527,9 +504,9 @@ sysfs_show_current_clocksources(struct sys_device *dev, { ssize_t count = 0; - spin_lock_irq(&clocksource_lock); + mutex_lock(&clocksource_mutex); count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name); - spin_unlock_irq(&clocksource_lock); + mutex_unlock(&clocksource_mutex); return count; } @@ -557,14 +534,14 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, if (buf[count-1] == '\n') count--; - spin_lock_irq(&clocksource_lock); + mutex_lock(&clocksource_mutex); if (count > 0) memcpy(override_name, buf, count); override_name[count] = 0; clocksource_select(); - spin_unlock_irq(&clocksource_lock); + mutex_unlock(&clocksource_mutex); return ret; } @@ -584,7 +561,7 @@ sysfs_show_available_clocksources(struct sys_device *dev, struct clocksource *src; ssize_t count = 0; - spin_lock_irq(&clocksource_lock); + mutex_lock(&clocksource_mutex); list_for_each_entry(src, &clocksource_list, list) { /* * Don't show non-HRES clocksource if the tick code is @@ -596,7 +573,7 @@ sysfs_show_available_clocksources(struct sys_device *dev, max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "%s ", src->name); } - spin_unlock_irq(&clocksource_lock); + mutex_unlock(&clocksource_mutex); count += snprintf(buf + count, max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n"); @@ -651,11 +628,10 @@ device_initcall(init_clocksource_sysfs); */ static int __init boot_override_clocksource(char* str) { - unsigned long flags; - spin_lock_irqsave(&clocksource_lock, flags); + mutex_lock(&clocksource_mutex); if (str) strlcpy(override_name, str, sizeof(override_name)); - spin_unlock_irqrestore(&clocksource_lock, flags); + mutex_unlock(&clocksource_mutex); return 1; } diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 27ae01b596b7..41579e7fcf9d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -18,6 +18,7 @@ #include #include #include +#include /* Structure holding internal timekeeping values. */ struct timekeeper { @@ -179,6 +180,7 @@ void timekeeping_leap_insert(int leapsecond) } #ifdef CONFIG_GENERIC_TIME + /** * timekeeping_forward_now - update clock to the current time * @@ -351,31 +353,40 @@ EXPORT_SYMBOL(do_settimeofday); * * Accumulates current time interval and initializes new clocksource */ -static void change_clocksource(void) +static int change_clocksource(void *data) { struct clocksource *new, *old; - new = clocksource_get_next(); - - if (!new || timekeeper.clock == new) - return; + new = (struct clocksource *) data; timekeeping_forward_now(); + if (!new->enable || new->enable(new) == 0) { + old = timekeeper.clock; + timekeeper_setup_internals(new); + if (old->disable) + old->disable(old); + } + return 0; +} - if (new->enable && !new->enable(new)) +/** + * timekeeping_notify - Install a new clock source + * @clock: pointer to the clock source + * + * This function is called from clocksource.c after a new, better clock + * source has been registered. The caller holds the clocksource_mutex. + */ +void timekeeping_notify(struct clocksource *clock) +{ + if (timekeeper.clock == clock) return; - - old = timekeeper.clock; - timekeeper_setup_internals(new); - - if (old->disable) - old->disable(old); - + stop_machine(change_clocksource, clock, NULL); tick_clock_notify(); } + #else /* GENERIC_TIME */ + static inline void timekeeping_forward_now(void) { } -static inline void change_clocksource(void) { } /** * ktime_get - get the monotonic time in ktime_t format @@ -416,6 +427,7 @@ void ktime_get_ts(struct timespec *ts) ts->tv_nsec + tomono.tv_nsec); } EXPORT_SYMBOL_GPL(ktime_get_ts); + #endif /* !GENERIC_TIME */ /** @@ -773,7 +785,6 @@ void update_wall_time(void) update_xtime_cache(nsecs); /* check to see if there is a new clocksource to use */ - change_clocksource(); update_vsyscall(&xtime, timekeeper.clock); } -- cgit v1.2.2 From d4f587c67fc39e0030ddd718675e252e208da4d7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:31 +0200 Subject: timekeeping: Increase granularity of read_persistent_clock() The persistent clock of some architectures (e.g. s390) have a better granularity than seconds. To reduce the delta between the host clock and the guest clock in a virtualized system change the read_persistent_clock function to return a struct timespec. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134811.013873340@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 52 ++++++++++++++++++++++++++--------------------- 1 file changed, 29 insertions(+), 23 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 41579e7fcf9d..f1a21ce491e6 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -154,7 +154,7 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock); */ struct timespec xtime __attribute__ ((aligned (16))); struct timespec wall_to_monotonic __attribute__ ((aligned (16))); -static unsigned long total_sleep_time; /* seconds */ +static struct timespec total_sleep_time; /* * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. @@ -487,17 +487,18 @@ int timekeeping_valid_for_hres(void) } /** - * read_persistent_clock - Return time in seconds from the persistent clock. + * read_persistent_clock - Return time from the persistent clock. * * Weak dummy function for arches that do not yet support it. - * Returns seconds from epoch using the battery backed persistent clock. - * Returns zero if unsupported. + * Reads the time from the battery backed persistent clock. + * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. * * XXX - Do be sure to remove it once all arches implement it. */ -unsigned long __attribute__((weak)) read_persistent_clock(void) +void __attribute__((weak)) read_persistent_clock(struct timespec *ts) { - return 0; + ts->tv_sec = 0; + ts->tv_nsec = 0; } /* @@ -507,7 +508,9 @@ void __init timekeeping_init(void) { struct clocksource *clock; unsigned long flags; - unsigned long sec = read_persistent_clock(); + struct timespec now; + + read_persistent_clock(&now); write_seqlock_irqsave(&xtime_lock, flags); @@ -518,19 +521,20 @@ void __init timekeeping_init(void) clock->enable(clock); timekeeper_setup_internals(clock); - xtime.tv_sec = sec; - xtime.tv_nsec = 0; + xtime.tv_sec = now.tv_sec; + xtime.tv_nsec = now.tv_nsec; raw_time.tv_sec = 0; raw_time.tv_nsec = 0; set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec); update_xtime_cache(0); - total_sleep_time = 0; + total_sleep_time.tv_sec = 0; + total_sleep_time.tv_nsec = 0; write_sequnlock_irqrestore(&xtime_lock, flags); } /* time in seconds when suspend began */ -static unsigned long timekeeping_suspend_time; +static struct timespec timekeeping_suspend_time; /** * timekeeping_resume - Resumes the generic timekeeping subsystem. @@ -543,18 +547,19 @@ static unsigned long timekeeping_suspend_time; static int timekeeping_resume(struct sys_device *dev) { unsigned long flags; - unsigned long now = read_persistent_clock(); + struct timespec ts; + + read_persistent_clock(&ts); clocksource_resume(); write_seqlock_irqsave(&xtime_lock, flags); - if (now && (now > timekeeping_suspend_time)) { - unsigned long sleep_length = now - timekeeping_suspend_time; - - xtime.tv_sec += sleep_length; - wall_to_monotonic.tv_sec -= sleep_length; - total_sleep_time += sleep_length; + if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) { + ts = timespec_sub(ts, timekeeping_suspend_time); + xtime = timespec_add_safe(xtime, ts); + wall_to_monotonic = timespec_sub(wall_to_monotonic, ts); + total_sleep_time = timespec_add_safe(total_sleep_time, ts); } update_xtime_cache(0); /* re-base the last cycle value */ @@ -577,7 +582,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) { unsigned long flags; - timekeeping_suspend_time = read_persistent_clock(); + read_persistent_clock(&timekeeping_suspend_time); write_seqlock_irqsave(&xtime_lock, flags); timekeeping_forward_now(); @@ -801,9 +806,10 @@ void update_wall_time(void) */ void getboottime(struct timespec *ts) { - set_normalized_timespec(ts, - - (wall_to_monotonic.tv_sec + total_sleep_time), - - wall_to_monotonic.tv_nsec); + struct timespec boottime; + + boottime = timespec_add_safe(wall_to_monotonic, total_sleep_time); + set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); } /** @@ -812,7 +818,7 @@ void getboottime(struct timespec *ts) */ void monotonic_to_bootbased(struct timespec *ts) { - ts->tv_sec += total_sleep_time; + *ts = timespec_add_safe(*ts, total_sleep_time); } unsigned long get_seconds(void) -- cgit v1.2.2 From 23970e389e9cee43c4b41023935e1417271708b2 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 14 Aug 2009 15:47:32 +0200 Subject: timekeeping: Introduce read_boot_clock Add the new function read_boot_clock to get the exact time the system has been started. For architectures without support for exact boot time a new weak function is added that returns 0. Use the exact boot time to initialize wall_to_monotonic, or xtime if the read_boot_clock returned 0. Signed-off-by: Martin Schwidefsky Cc: Ingo Molnar Acked-by: John Stultz Cc: Daniel Walker LKML-Reference: <20090814134811.296703241@de.ibm.com> Signed-off-by: Thomas Gleixner --- kernel/time/timekeeping.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index f1a21ce491e6..15e06defca55 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -501,6 +501,21 @@ void __attribute__((weak)) read_persistent_clock(struct timespec *ts) ts->tv_nsec = 0; } +/** + * read_boot_clock - Return time of the system start. + * + * Weak dummy function for arches that do not yet support it. + * Function to read the exact time the system has been started. + * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. + * + * XXX - Do be sure to remove it once all arches implement it. + */ +void __attribute__((weak)) read_boot_clock(struct timespec *ts) +{ + ts->tv_sec = 0; + ts->tv_nsec = 0; +} + /* * timekeeping_init - Initializes the clocksource and common timekeeping values */ @@ -508,9 +523,10 @@ void __init timekeeping_init(void) { struct clocksource *clock; unsigned long flags; - struct timespec now; + struct timespec now, boot; read_persistent_clock(&now); + read_boot_clock(&boot); write_seqlock_irqsave(&xtime_lock, flags); @@ -525,8 +541,12 @@ void __init timekeeping_init(void) xtime.tv_nsec = now.tv_nsec; raw_time.tv_sec = 0; raw_time.tv_nsec = 0; + if (boot.tv_sec == 0 && boot.tv_nsec == 0) { + boot.tv_sec = xtime.tv_sec; + boot.tv_nsec = xtime.tv_nsec; + } set_normalized_timespec(&wall_to_monotonic, - -xtime.tv_sec, -xtime.tv_nsec); + -boot.tv_sec, -boot.tv_nsec); update_xtime_cache(0); total_sleep_time.tv_sec = 0; total_sleep_time.tv_nsec = 0; -- cgit v1.2.2 From 6ea41d252f35465a2308a4038a323b6b07de06f6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 15 Aug 2009 13:20:42 +0200 Subject: clocksource: Call clocksource_change_rating() outside of watchdog_lock The changes to the watchdog logic introduced a lock inversion between watchdog_lock and clocksource_mutex. Change the rating outside of watchdog_lock to avoid it. Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index a1657b5fdeb9..02dc22d888fe 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -307,16 +307,23 @@ static void clocksource_watchdog_work(struct work_struct *work) { struct clocksource *cs, *tmp; unsigned long flags; + LIST_HEAD(unstable); spin_lock_irqsave(&watchdog_lock, flags); list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) if (cs->flags & CLOCK_SOURCE_UNSTABLE) { list_del_init(&cs->wd_list); - clocksource_change_rating(cs, 0); + list_add(&cs->wd_list, &unstable); } /* Check if the watchdog timer needs to be stopped. */ clocksource_stop_watchdog(); - spin_unlock(&watchdog_lock); + spin_unlock_irqrestore(&watchdog_lock, flags); + + /* Needs to be done outside of watchdog lock */ + list_for_each_entry_safe(cs, tmp, &unstable, wd_list) { + list_del_init(&cs->wd_list); + clocksource_change_rating(cs, 0); + } } #else /* CONFIG_CLOCKSOURCE_WATCHDOG */ -- cgit v1.2.2 From de481560eb0bd9d940b90311eba85711e4b1150b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 30 Apr 2009 12:32:04 -0400 Subject: kconfig: keep config.gz around even if CONFIG_IKCONFIG_PROC is not set If CONFIG_IKCONFIG is set but CONFIG_IKCONFIG_PROC is not, then gcc will optimize the config.gz out, because nobody uses it. This patch adds "__used" to the config.gz data to keep it around so that code like extract-ikconfig can still find it. [ Impact: allow extract-ikconfig to find config.gz ] Signed-off-by: Steven Rostedt --- kernel/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 2093a691f1c2..d0c84e6bf50a 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -119,7 +119,7 @@ $(obj)/config_data.gz: .config FORCE $(call if_changed,gzip) quiet_cmd_ikconfiggz = IKCFG $@ - cmd_ikconfiggz = (echo "static const char kernel_config_data[] = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;") > $@ + cmd_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;") > $@ targets += config_data.h $(obj)/config_data.h: $(obj)/config_data.gz FORCE $(call if_changed,ikconfiggz) -- cgit v1.2.2 From d0981a1b21a03866c8da7f44e35e389c2e0d6061 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 19 Aug 2009 11:26:09 +0200 Subject: clocksource: Protect the watchdog rating changes with clocksource_mutex Martin pointed out that commit 6ea41d2529 (clocksource: Call clocksource_change_rating() outside of watchdog_lock) has a theoretical reference count problem. The calls to clocksource_change_rating() are now done outside of the clocksource mutex and outside of the watchdog lock. A concurrent clocksource_unregister() could remove the clock. Split out the code which changes the rating from clocksource_change_rating() into __clocksource_change_rating(). Protect the clocksource_watchdog_work() code sequence with the clocksource_mutex() and call __clocksource_change_rating(). LKML-Reference: Signed-off-by: Thomas Gleixner Cc: Martin Schwidefsky --- kernel/time/clocksource.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 02dc22d888fe..c6bff11f7957 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -131,6 +131,7 @@ static cycle_t watchdog_last; static int watchdog_running; static void clocksource_watchdog_work(struct work_struct *work); +static void __clocksource_change_rating(struct clocksource *cs, int rating); /* * Interval: 0.5sec Threshold: 0.0625s @@ -309,6 +310,7 @@ static void clocksource_watchdog_work(struct work_struct *work) unsigned long flags; LIST_HEAD(unstable); + mutex_lock(&clocksource_mutex); spin_lock_irqsave(&watchdog_lock, flags); list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) if (cs->flags & CLOCK_SOURCE_UNSTABLE) { @@ -322,8 +324,9 @@ static void clocksource_watchdog_work(struct work_struct *work) /* Needs to be done outside of watchdog lock */ list_for_each_entry_safe(cs, tmp, &unstable, wd_list) { list_del_init(&cs->wd_list); - clocksource_change_rating(cs, 0); + __clocksource_change_rating(cs, 0); } + mutex_unlock(&clocksource_mutex); } #else /* CONFIG_CLOCKSOURCE_WATCHDOG */ @@ -470,16 +473,21 @@ int clocksource_register(struct clocksource *cs) } EXPORT_SYMBOL(clocksource_register); +static void __clocksource_change_rating(struct clocksource *cs, int rating) +{ + list_del(&cs->list); + cs->rating = rating; + clocksource_enqueue(cs); + clocksource_select(); +} + /** * clocksource_change_rating - Change the rating of a registered clocksource */ void clocksource_change_rating(struct clocksource *cs, int rating) { mutex_lock(&clocksource_mutex); - list_del(&cs->list); - cs->rating = rating; - clocksource_enqueue(cs); - clocksource_select(); + __clocksource_change_rating(cs, rating); mutex_unlock(&clocksource_mutex); } EXPORT_SYMBOL(clocksource_change_rating); -- cgit v1.2.2 From 01548f4d3e8e94caf323a4f664eb347fd34a34ab Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 18 Aug 2009 17:09:42 +0200 Subject: clocksource: Avoid clocksource watchdog circular locking dependency stop_machine from a multithreaded workqueue is not allowed because of a circular locking dependency between cpu_down and the workqueue execution. Use a kernel thread to do the clocksource downgrade. Signed-off-by: Martin Schwidefsky Cc: Peter Zijlstra Cc: john stultz LKML-Reference: <20090818170942.3ab80c91@skybase> Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index c6bff11f7957..e0c86ad6e9fb 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -29,6 +29,7 @@ #include #include /* for spin_unlock_irq() using preempt_count() m68k */ #include +#include void timecounter_init(struct timecounter *tc, const struct cyclecounter *cc, @@ -130,7 +131,7 @@ static DEFINE_SPINLOCK(watchdog_lock); static cycle_t watchdog_last; static int watchdog_running; -static void clocksource_watchdog_work(struct work_struct *work); +static int clocksource_watchdog_kthread(void *data); static void __clocksource_change_rating(struct clocksource *cs, int rating); /* @@ -139,6 +140,15 @@ static void __clocksource_change_rating(struct clocksource *cs, int rating); #define WATCHDOG_INTERVAL (HZ >> 1) #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) +static void clocksource_watchdog_work(struct work_struct *work) +{ + /* + * If kthread_run fails the next watchdog scan over the + * watchdog_list will find the unstable clock again. + */ + kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog"); +} + static void clocksource_unstable(struct clocksource *cs, int64_t delta) { printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n", @@ -167,8 +177,10 @@ static void clocksource_watchdog(unsigned long data) list_for_each_entry(cs, &watchdog_list, wd_list) { /* Clocksource already marked unstable? */ - if (cs->flags & CLOCK_SOURCE_UNSTABLE) + if (cs->flags & CLOCK_SOURCE_UNSTABLE) { + schedule_work(&watchdog_work); continue; + } csnow = cs->read(cs); @@ -304,7 +316,7 @@ static void clocksource_dequeue_watchdog(struct clocksource *cs) spin_unlock_irqrestore(&watchdog_lock, flags); } -static void clocksource_watchdog_work(struct work_struct *work) +static int clocksource_watchdog_kthread(void *data) { struct clocksource *cs, *tmp; unsigned long flags; @@ -327,6 +339,7 @@ static void clocksource_watchdog_work(struct work_struct *work) __clocksource_change_rating(cs, 0); } mutex_unlock(&clocksource_mutex); + return 0; } #else /* CONFIG_CLOCKSOURCE_WATCHDOG */ -- cgit v1.2.2 From a15098c90df1ac2b1bfe1d33dd1c47063213aa9a Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Sun, 9 Aug 2009 19:02:51 +0000 Subject: powerpc: Enable GCOV Make it possible to enable GCOV code coverage measurement on powerpc. Lightly tested on 64-bit, seems to work as expected. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- kernel/gcov/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig index 22e9dcfaa3d3..654efd09f6a9 100644 --- a/kernel/gcov/Kconfig +++ b/kernel/gcov/Kconfig @@ -34,7 +34,7 @@ config GCOV_KERNEL config GCOV_PROFILE_ALL bool "Profile entire Kernel" depends on GCOV_KERNEL - depends on S390 || X86 + depends on S390 || X86 || (PPC && EXPERIMENTAL) default n ---help--- This options activates profiling for the entire kernel. -- cgit v1.2.2 From da15cfdae03351c689736f8d142618592e3cebc3 Mon Sep 17 00:00:00 2001 From: john stultz Date: Wed, 19 Aug 2009 19:13:34 -0700 Subject: time: Introduce CLOCK_REALTIME_COARSE After talking with some application writers who want very fast, but not fine-grained timestamps, I decided to try to implement new clock_ids to clock_gettime(): CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE which returns the time at the last tick. This is very fast as we don't have to access any hardware (which can be very painful if you're using something like the acpi_pm clocksource), and we can even use the vdso clock_gettime() method to avoid the syscall. The only trade off is you only get low-res tick grained time resolution. This isn't a new idea, I know Ingo has a patch in the -rt tree that made the vsyscall gettimeofday() return coarse grained time when the vsyscall64 sysctrl was set to 2. However this affects all applications on a system. With this method, applications can choose the proper speed/granularity trade-off for themselves. Signed-off-by: John Stultz Cc: Andi Kleen Cc: nikolag@ca.ibm.com Cc: Darren Hart Cc: arjan@infradead.org Cc: jonathan@jonmasters.org LKML-Reference: <1250734414.6897.5.camel@localhost.localdomain> Signed-off-by: Thomas Gleixner --- kernel/posix-timers.c | 35 +++++++++++++++++++++++++++++++++++ kernel/time/timekeeping.c | 21 +++++++++++++++++++++ 2 files changed, 56 insertions(+) (limited to 'kernel') diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index d089d052c4a9..495440779ce3 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -242,6 +242,25 @@ static int posix_get_monotonic_raw(clockid_t which_clock, struct timespec *tp) return 0; } + +static int posix_get_realtime_coarse(clockid_t which_clock, struct timespec *tp) +{ + *tp = current_kernel_time(); + return 0; +} + +static int posix_get_monotonic_coarse(clockid_t which_clock, + struct timespec *tp) +{ + *tp = get_monotonic_coarse(); + return 0; +} + +int posix_get_coarse_res(const clockid_t which_clock, struct timespec *tp) +{ + *tp = ktime_to_timespec(KTIME_LOW_RES); + return 0; +} /* * Initialize everything, well, just everything in Posix clocks/timers ;) */ @@ -262,10 +281,26 @@ static __init int init_posix_timers(void) .timer_create = no_timer_create, .nsleep = no_nsleep, }; + struct k_clock clock_realtime_coarse = { + .clock_getres = posix_get_coarse_res, + .clock_get = posix_get_realtime_coarse, + .clock_set = do_posix_clock_nosettime, + .timer_create = no_timer_create, + .nsleep = no_nsleep, + }; + struct k_clock clock_monotonic_coarse = { + .clock_getres = posix_get_coarse_res, + .clock_get = posix_get_monotonic_coarse, + .clock_set = do_posix_clock_nosettime, + .timer_create = no_timer_create, + .nsleep = no_nsleep, + }; register_posix_clock(CLOCK_REALTIME, &clock_realtime); register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); register_posix_clock(CLOCK_MONOTONIC_RAW, &clock_monotonic_raw); + register_posix_clock(CLOCK_REALTIME_COARSE, &clock_realtime_coarse); + register_posix_clock(CLOCK_MONOTONIC_COARSE, &clock_monotonic_coarse); posix_timers_cache = kmem_cache_create("posix_timers_cache", sizeof (struct k_itimer), 0, SLAB_PANIC, diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 15e06defca55..03cbeb34d141 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -847,6 +847,10 @@ unsigned long get_seconds(void) } EXPORT_SYMBOL(get_seconds); +struct timespec __current_kernel_time(void) +{ + return xtime_cache; +} struct timespec current_kernel_time(void) { @@ -862,3 +866,20 @@ struct timespec current_kernel_time(void) return now; } EXPORT_SYMBOL(current_kernel_time); + +struct timespec get_monotonic_coarse(void) +{ + struct timespec now, mono; + unsigned long seq; + + do { + seq = read_seqbegin(&xtime_lock); + + now = xtime_cache; + mono = wall_to_monotonic; + } while (read_seqretry(&xtime_lock, seq)); + + set_normalized_timespec(&now, now.tv_sec + mono.tv_sec, + now.tv_nsec + mono.tv_nsec); + return now; +} -- cgit v1.2.2 From 269c861baa2fe7c114c3bc7831292758d29eb336 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Wed, 19 Aug 2009 18:05:35 -0700 Subject: generic-ipi: Allow cpus not yet online to call smp_call_function with irqs disabled Because of deadlock possiblities smp_call_function() is not allowed to be called with interrupts disabled. Add an exception for the cpu not yet online, as no one else can send smp call function interrupt to this cpu that is not yet online and as such deadlock condition is not possible. Signed-off-by: Suresh Siddha Acked-by: Nick Piggin Signed-off-by: H. Peter Anvin --- kernel/smp.c | 40 ++++++++++++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/smp.c b/kernel/smp.c index ad63d8501207..2accdf6712e5 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -176,6 +176,11 @@ void generic_smp_call_function_interrupt(void) struct call_function_data *data; int cpu = get_cpu(); + /* + * Shouldn't receive this interrupt on a cpu that is not yet online. + */ + WARN_ON_ONCE(!cpu_online(cpu)); + /* * Ensure entry is visible on call_function_queue after we have * entered the IPI. See comment in smp_call_function_many. @@ -230,6 +235,11 @@ void generic_smp_call_function_single_interrupt(void) unsigned int data_flags; LIST_HEAD(list); + /* + * Shouldn't receive this interrupt on a cpu that is not yet online. + */ + WARN_ON_ONCE(!cpu_online(smp_processor_id())); + spin_lock(&q->lock); list_replace_init(&q->list, &list); spin_unlock(&q->lock); @@ -285,8 +295,14 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info, */ this_cpu = get_cpu(); - /* Can deadlock when called with interrupts disabled */ - WARN_ON_ONCE(irqs_disabled() && !oops_in_progress); + /* + * Can deadlock when called with interrupts disabled. + * We allow cpu's that are not yet online though, as no one else can + * send smp call function interrupt to this cpu and as such deadlocks + * can't happen. + */ + WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() + && !oops_in_progress); if (cpu == this_cpu) { local_irq_save(flags); @@ -329,8 +345,14 @@ void __smp_call_function_single(int cpu, struct call_single_data *data, { csd_lock(data); - /* Can deadlock when called with interrupts disabled */ - WARN_ON_ONCE(wait && irqs_disabled() && !oops_in_progress); + /* + * Can deadlock when called with interrupts disabled. + * We allow cpu's that are not yet online though, as no one else can + * send smp call function interrupt to this cpu and as such deadlocks + * can't happen. + */ + WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled() + && !oops_in_progress); generic_exec_single(cpu, data, wait); } @@ -365,8 +387,14 @@ void smp_call_function_many(const struct cpumask *mask, unsigned long flags; int cpu, next_cpu, this_cpu = smp_processor_id(); - /* Can deadlock when called with interrupts disabled */ - WARN_ON_ONCE(irqs_disabled() && !oops_in_progress); + /* + * Can deadlock when called with interrupts disabled. + * We allow cpu's that are not yet online though, as no one else can + * send smp call function interrupt to this cpu and as such deadlocks + * can't happen. + */ + WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() + && !oops_in_progress); /* So, what's a CPU they want? Ignoring this one. */ cpu = cpumask_first_and(mask, cpu_online_mask); -- cgit v1.2.2 From d0af9eed5aa91b6b7b5049cae69e5ea956fd85c3 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Wed, 19 Aug 2009 18:05:36 -0700 Subject: x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init SDM Vol 3a section titled "MTRR considerations in MP systems" specifies the need for synchronizing the logical cpu's while initializing/updating MTRR. Currently Linux kernel does the synchronization of all cpu's only when a single MTRR register is programmed/updated. During an AP online (during boot/cpu-online/resume) where we initialize all the MTRR/PAT registers, we don't follow this synchronization algorithm. This can lead to scenarios where during a dynamic cpu online, that logical cpu is initializing MTRR/PAT with cache disabled (cr0.cd=1) etc while other logical HT sibling continue to run (also with cache disabled because of cr0.cd=1 on its sibling). Starting from Westmere, VMX transitions with cr0.cd=1 don't work properly (because of some VMX performance optimizations) and the above scenario (with one logical cpu doing VMX activity and another logical cpu coming online) can result in system crash. Fix the MTRR initialization by doing rendezvous of all the cpus. During boot and resume, we delay the MTRR/PAT init for APs till all the logical cpu's come online and the rendezvous process at the end of AP's bringup, will initialize the MTRR/PAT for all AP's. For dynamic single cpu online, we synchronize all the logical cpus and do the MTRR/PAT init on the AP that is coming online. Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- kernel/cpu.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index 8ce10043e4ac..f5f9485b8c0f 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -413,6 +413,14 @@ int disable_nonboot_cpus(void) return error; } +void __weak arch_enable_nonboot_cpus_begin(void) +{ +} + +void __weak arch_enable_nonboot_cpus_end(void) +{ +} + void __ref enable_nonboot_cpus(void) { int cpu, error; @@ -424,6 +432,9 @@ void __ref enable_nonboot_cpus(void) goto out; printk("Enabling non-boot CPUs ...\n"); + + arch_enable_nonboot_cpus_begin(); + for_each_cpu(cpu, frozen_cpus) { error = _cpu_up(cpu, 1); if (!error) { @@ -432,6 +443,9 @@ void __ref enable_nonboot_cpus(void) } printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error); } + + arch_enable_nonboot_cpus_end(); + cpumask_clear(frozen_cpus); out: cpu_maps_update_done(); -- cgit v1.2.2 From 5e928f77a09a07f9dd595bb8a489965d69a83458 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 18 Aug 2009 23:38:32 +0200 Subject: PM: Introduce core framework for run-time PM of I/O devices (rev. 17) Introduce a core framework for run-time power management of I/O devices. Add device run-time PM fields to 'struct dev_pm_info' and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce a run-time PM workqueue and define some device run-time PM helper functions at the core level. Document all these things. Special thanks to Alan Stern for his help with the design and multiple detailed reviews of the pereceding versions of this patch and to Magnus Damm for testing feedback. Signed-off-by: Rafael J. Wysocki Acked-by: Magnus Damm --- kernel/power/Kconfig | 14 ++++++++++++++ kernel/power/main.c | 17 +++++++++++++++++ 2 files changed, 31 insertions(+) (limited to 'kernel') diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 72067cbdb37f..91e09d3b2eb2 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -208,3 +208,17 @@ config APM_EMULATION random kernel OOPSes or reboots that don't seem to be related to anything, try disabling/enabling this option (or disabling/enabling APM in your BIOS). + +config PM_RUNTIME + bool "Run-time PM core functionality" + depends on PM + ---help--- + Enable functionality allowing I/O devices to be put into energy-saving + (low power) states at run time (or autosuspended) after a specified + period of inactivity and woken up in response to a hardware-generated + wake-up event or a driver's request. + + Hardware support is generally required for this functionality to work + and the bus type drivers of the buses the devices are on are + responsible for the actual handling of the autosuspend requests and + wake-up events. diff --git a/kernel/power/main.c b/kernel/power/main.c index f710e36930cc..347d2cc88cd0 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "power.h" @@ -217,8 +218,24 @@ static struct attribute_group attr_group = { .attrs = g, }; +#ifdef CONFIG_PM_RUNTIME +struct workqueue_struct *pm_wq; + +static int __init pm_start_workqueue(void) +{ + pm_wq = create_freezeable_workqueue("pm"); + + return pm_wq ? 0 : -ENOMEM; +} +#else +static inline int pm_start_workqueue(void) { return 0; } +#endif + static int __init pm_init(void) { + int error = pm_start_workqueue(); + if (error) + return error; power_kobj = kobject_create_and_add("power", NULL); if (!power_kobj) return -ENOMEM; -- cgit v1.2.2 From 36d47481b3824b661b464077db95d447984df799 Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto Date: Tue, 25 Aug 2009 15:08:30 +0900 Subject: timekeeping: Fix invalid getboottime() value Don't use timespec_add_safe() with wall_to_monotonic, because wall_to_monotonic has negative values which will cause overflow in timespec_add_safe(). That makes btime in /proc/stat invalid. Signed-off-by: Hiroshi Shimamoto Cc: Martin Schwidefsky Cc: John Stultz Cc: Daniel Walker LKML-Reference: <4A937FDE.4050506@ct.jp.nec.com> Signed-off-by: Ingo Molnar --- kernel/time/timekeeping.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 03cbeb34d141..fb0f46fa1ecd 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -826,9 +826,11 @@ void update_wall_time(void) */ void getboottime(struct timespec *ts) { - struct timespec boottime; + struct timespec boottime = { + .tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec, + .tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec + }; - boottime = timespec_add_safe(wall_to_monotonic, total_sleep_time); set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec); } -- cgit v1.2.2 From 90cba64a5f672a239f43ec5cb9a11b806887331e Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Tue, 25 Aug 2009 14:35:41 -0700 Subject: timer.c: Fix S/390 comments Fix typos and add omitted words. Signed-off-by: Randy Dunlap Cc: akpm Cc: linux390@de.ibm.com Cc: Martin Schwidefsky Cc: Heiko Carstens LKML-Reference: <20090825143541.43fc2ed8.randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar --- kernel/timer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/timer.c b/kernel/timer.c index 33fc9d175f40..8e92be654dad 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1023,8 +1023,8 @@ static inline void __run_timers(struct tvec_base *base) #ifdef CONFIG_NO_HZ /* * Find out when the next timer event is due to happen. This - * is used on S/390 to stop all activity when a cpus is idle. - * This functions needs to be called disabled. + * is used on S/390 to stop all activity when a CPU is idle. + * This function needs to be called with interrupts disabled. */ static unsigned long __next_timer_interrupt(struct tvec_base *base) { -- cgit v1.2.2 From 7285dd7fd375763bfb8ab1ac9cf3f1206f503c16 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 28 Aug 2009 20:25:24 +0200 Subject: clocksource: Resolve cpu hotplug dead lock with TSC unstable Martin Schwidefsky analyzed it: To register a clocksource the clocksource_mutex is acquired and if necessary timekeeping_notify is called to install the clocksource as the timekeeper clock. timekeeping_notify uses stop_machine which needs to take cpu_add_remove_lock mutex. Starting a new cpu is done with the cpu_add_remove_lock mutex held. native_cpu_up checks the tsc of the new cpu and if the tsc is no good clocksource_change_rating is called. Which needs the clocksource_mutex and the deadlock is complete. The solution is to replace the TSC via the clocksource watchdog mechanism. Mark the TSC as unstable and schedule the watchdog work so it gets removed in the watchdog thread context. Signed-off-by: Thomas Gleixner LKML-Reference: Cc: Martin Schwidefsky Cc: John Stultz --- kernel/time/clocksource.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index e0c86ad6e9fb..a0af4ffcb6e5 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -149,15 +149,42 @@ static void clocksource_watchdog_work(struct work_struct *work) kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog"); } -static void clocksource_unstable(struct clocksource *cs, int64_t delta) +static void __clocksource_unstable(struct clocksource *cs) { - printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n", - cs->name, delta); cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); cs->flags |= CLOCK_SOURCE_UNSTABLE; schedule_work(&watchdog_work); } +static void clocksource_unstable(struct clocksource *cs, int64_t delta) +{ + printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n", + cs->name, delta); + __clocksource_unstable(cs); +} + +/** + * clocksource_mark_unstable - mark clocksource unstable via watchdog + * @cs: clocksource to be marked unstable + * + * This function is called instead of clocksource_change_rating from + * cpu hotplug code to avoid a deadlock between the clocksource mutex + * and the cpu hotplug mutex. It defers the update of the clocksource + * to the watchdog thread. + */ +void clocksource_mark_unstable(struct clocksource *cs) +{ + unsigned long flags; + + spin_lock_irqsave(&watchdog_lock, flags); + if (!(cs->flags & CLOCK_SOURCE_UNSTABLE)) { + if (list_empty(&cs->wd_list)) + list_add(&cs->wd_list, &watchdog_list); + __clocksource_unstable(cs); + } + spin_unlock_irqrestore(&watchdog_lock, flags); +} + static void clocksource_watchdog(unsigned long data) { struct clocksource *cs; -- cgit v1.2.2 From 2b022e3d4bf9885f781221c59d86283a2cdfc2ed Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:48:59 +0800 Subject: timers: Add tracepoints for timer_list timers Add tracepoints which cover the timer life cycle. The tracepoints are integrated with the already existing debug_object debug points as far as possible. Based on patches from Mathieu: http://marc.info/?l=linux-kernel&m=123791201816247&w=2 and Anton: http://marc.info/?l=linux-kernel&m=124331396919301&w=2 [ tglx: Fixed timeout value in timer_start tracepoint, massaged comments and made the printk's more readable ] Signed-off-by: Xiao Guangrong Cc: Anton Blanchard Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: KOSAKI Motohiro Cc: Zhaolei LKML-Reference: <4A7F8A9B.3040201@cn.fujitsu.com> Signed-off-by: Thomas Gleixner --- kernel/timer.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/timer.c b/kernel/timer.c index 8e92be654dad..a7352b00703c 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -46,6 +46,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES; EXPORT_SYMBOL(jiffies_64); @@ -521,6 +524,25 @@ static inline void debug_timer_activate(struct timer_list *timer) { } static inline void debug_timer_deactivate(struct timer_list *timer) { } #endif +static inline void debug_init(struct timer_list *timer) +{ + debug_timer_init(timer); + trace_timer_init(timer); +} + +static inline void +debug_activate(struct timer_list *timer, unsigned long expires) +{ + debug_timer_activate(timer); + trace_timer_start(timer, expires); +} + +static inline void debug_deactivate(struct timer_list *timer) +{ + debug_timer_deactivate(timer); + trace_timer_cancel(timer); +} + static void __init_timer(struct timer_list *timer, const char *name, struct lock_class_key *key) @@ -549,7 +571,7 @@ void init_timer_key(struct timer_list *timer, const char *name, struct lock_class_key *key) { - debug_timer_init(timer); + debug_init(timer); __init_timer(timer, name, key); } EXPORT_SYMBOL(init_timer_key); @@ -568,7 +590,7 @@ static inline void detach_timer(struct timer_list *timer, { struct list_head *entry = &timer->entry; - debug_timer_deactivate(timer); + debug_deactivate(timer); __list_del(entry->prev, entry->next); if (clear_pending) @@ -632,7 +654,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires, goto out_unlock; } - debug_timer_activate(timer); + debug_activate(timer, expires); new_base = __get_cpu_var(tvec_bases); @@ -787,7 +809,7 @@ void add_timer_on(struct timer_list *timer, int cpu) BUG_ON(timer_pending(timer) || !timer->function); spin_lock_irqsave(&base->lock, flags); timer_set_base(timer, base); - debug_timer_activate(timer); + debug_activate(timer, timer->expires); if (time_before(timer->expires, base->next_timer) && !tbase_get_deferrable(timer->base)) base->next_timer = timer->expires; @@ -1000,7 +1022,9 @@ static inline void __run_timers(struct tvec_base *base) */ lock_map_acquire(&lockdep_map); + trace_timer_expire_entry(timer); fn(data); + trace_timer_expire_exit(timer); lock_map_release(&lockdep_map); -- cgit v1.2.2 From c6a2a1770245f654f35f60e1458d4356680f9519 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:51:23 +0800 Subject: hrtimer: Add tracepoint for hrtimers Add tracepoints which cover the life cycle of a hrtimer. The tracepoints are integrated with the already existing debug_object debug points as far as possible. [ tglx: Fixed comments, made output conistent, easier to read and parse. Fixed output for 32bit archs which do not use the scalar representation of ktime_t. Hand current time to trace_hrtimer_expiry_entry instead of calling get_time() inside of the trace assignment. ] Signed-off-by: Xiao Guangrong Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Anton Blanchard Cc: Peter Zijlstra Cc: KOSAKI Motohiro Cc: Zhaolei LKML-Reference: <4A7F8B2B.5020908@cn.fujitsu.com> Signed-off-by: Thomas Gleixner --- kernel/hrtimer.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index e2f91ecc01a8..b44d1b07377b 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -48,6 +48,8 @@ #include +#include + /* * The timer bases: * @@ -441,6 +443,26 @@ static inline void debug_hrtimer_activate(struct hrtimer *timer) { } static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { } #endif +static inline void +debug_init(struct hrtimer *timer, clockid_t clockid, + enum hrtimer_mode mode) +{ + debug_hrtimer_init(timer); + trace_hrtimer_init(timer, clockid, mode); +} + +static inline void debug_activate(struct hrtimer *timer) +{ + debug_hrtimer_activate(timer); + trace_hrtimer_start(timer); +} + +static inline void debug_deactivate(struct hrtimer *timer) +{ + debug_hrtimer_deactivate(timer); + trace_hrtimer_cancel(timer); +} + /* High resolution timer related functions */ #ifdef CONFIG_HIGH_RES_TIMERS @@ -797,7 +819,7 @@ static int enqueue_hrtimer(struct hrtimer *timer, struct hrtimer *entry; int leftmost = 1; - debug_hrtimer_activate(timer); + debug_activate(timer); /* * Find the right place in the rbtree: @@ -883,7 +905,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) * reprogramming happens in the interrupt handler. This is a * rare case and less expensive than a smp call. */ - debug_hrtimer_deactivate(timer); + debug_deactivate(timer); timer_stats_hrtimer_clear_start_info(timer); reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases); __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, @@ -1116,7 +1138,7 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode) { - debug_hrtimer_init(timer); + debug_init(timer, clock_id, mode); __hrtimer_init(timer, clock_id, mode); } EXPORT_SYMBOL_GPL(hrtimer_init); @@ -1140,7 +1162,7 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) } EXPORT_SYMBOL_GPL(hrtimer_get_res); -static void __run_hrtimer(struct hrtimer *timer) +static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) { struct hrtimer_clock_base *base = timer->base; struct hrtimer_cpu_base *cpu_base = base->cpu_base; @@ -1149,7 +1171,7 @@ static void __run_hrtimer(struct hrtimer *timer) WARN_ON(!irqs_disabled()); - debug_hrtimer_deactivate(timer); + debug_deactivate(timer); __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); timer_stats_account_hrtimer(timer); fn = timer->function; @@ -1160,7 +1182,9 @@ static void __run_hrtimer(struct hrtimer *timer) * the timer base. */ spin_unlock(&cpu_base->lock); + trace_hrtimer_expire_entry(timer, now); restart = fn(timer); + trace_hrtimer_expire_exit(timer); spin_lock(&cpu_base->lock); /* @@ -1271,7 +1295,7 @@ void hrtimer_interrupt(struct clock_event_device *dev) break; } - __run_hrtimer(timer); + __run_hrtimer(timer, &basenow); } base++; } @@ -1393,7 +1417,7 @@ void hrtimer_run_queues(void) hrtimer_get_expires_tv64(timer)) break; - __run_hrtimer(timer); + __run_hrtimer(timer, &base->softirq_time); } spin_unlock(&cpu_base->lock); } @@ -1569,7 +1593,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, while ((node = rb_first(&old_base->active))) { timer = rb_entry(node, struct hrtimer, node); BUG_ON(hrtimer_callback_running(timer)); - debug_hrtimer_deactivate(timer); + debug_deactivate(timer); /* * Mark it as STATE_MIGRATE not INACTIVE otherwise the -- cgit v1.2.2 From 3f0a525ebf4b8ef041a332bbe4a73aee94bb064b Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:52:30 +0800 Subject: itimers: Add tracepoints for itimer Add tracepoints for all itimer variants: ITIMER_REAL, ITIMER_VIRTUAL and ITIMER_PROF. [ tglx: Fixed comments and made the output more readable, parseable and consistent. Replaced pid_vnr by pid_nr because the hrtimer callback can happen in any namespace ] Signed-off-by: Xiao Guangrong Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Anton Blanchard Cc: Peter Zijlstra Cc: KOSAKI Motohiro Cc: Zhaolei LKML-Reference: <4A7F8B6E.2010109@cn.fujitsu.com> Signed-off-by: Thomas Gleixner --- kernel/itimer.c | 5 +++++ kernel/posix-cpu-timers.c | 7 ++++++- 2 files changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/itimer.c b/kernel/itimer.c index 8078a32d3b10..b03451ede528 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -12,6 +12,7 @@ #include #include #include +#include #include @@ -122,6 +123,7 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) struct signal_struct *sig = container_of(timer, struct signal_struct, real_timer); + trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0); kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid); return HRTIMER_NORESTART; @@ -166,6 +168,8 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, } it->expires = nval; it->incr = ninterval; + trace_itimer_state(clock_id == CPUCLOCK_VIRT ? + ITIMER_VIRTUAL : ITIMER_PROF, value, nval); spin_unlock_irq(&tsk->sighand->siglock); @@ -217,6 +221,7 @@ again: } else tsk->signal->it_real_incr.tv64 = 0; + trace_itimer_state(ITIMER_REAL, value, 0); spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 12161f74744e..5c9dc228747b 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -8,6 +8,7 @@ #include #include #include +#include /* * Called after updating RLIMIT_CPU to set timer expiration if necessary. @@ -1090,9 +1091,13 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, cputime_one_jiffy); it->error -= onecputick; } - } else + } else { it->expires = cputime_zero; + } + trace_itimer_expire(signo == SIGPROF ? + ITIMER_PROF : ITIMER_VIRTUAL, + tsk->signal->leader_pid, cur_time); __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } -- cgit v1.2.2 From 69575d388603365f2afbf4166df93152df59b165 Mon Sep 17 00:00:00 2001 From: Shane Wang Date: Tue, 1 Sep 2009 18:25:07 -0700 Subject: x86, intel_txt: clean up the impact on generic code, unbreak non-x86 Move tboot.h from asm to linux to fix the build errors of intel_txt patch on non-X86 platforms. Remove the tboot code from generic code init/main.c and kernel/cpu.c. Signed-off-by: Shane Wang Signed-off-by: H. Peter Anvin --- kernel/cpu.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index ff071e022a85..67a60076dd7e 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -14,7 +14,6 @@ #include #include #include -#include #ifdef CONFIG_SMP /* Serializes the updates to cpu_online_mask, cpu_present_mask */ @@ -377,7 +376,7 @@ static cpumask_var_t frozen_cpus; int disable_nonboot_cpus(void) { - int cpu, first_cpu, error, num_cpus = 0; + int cpu, first_cpu, error; error = stop_machine_create(); if (error) @@ -392,7 +391,6 @@ int disable_nonboot_cpus(void) for_each_online_cpu(cpu) { if (cpu == first_cpu) continue; - num_cpus++; error = _cpu_down(cpu, 1); if (!error) { cpumask_set_cpu(cpu, frozen_cpus); @@ -403,8 +401,6 @@ int disable_nonboot_cpus(void) break; } } - /* ensure all CPUs have gone into wait-for-SIPI */ - error |= tboot_wait_for_aps(num_cpus); if (!error) { BUG_ON(num_online_cpus() > 1); -- cgit v1.2.2 From d8eeb2d3b26d25c44c10f28430e2157a2d20bd1d Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Fri, 31 Jul 2009 14:58:04 +0200 Subject: ring-buffer: consolidate interface of rb_buffer_peek() rb_buffer_peek() operates with struct ring_buffer_per_cpu *cpu_buffer only. Thus, instead of passing variables buffer and cpu it is better to use cpu_buffer directly. This also reduces the risk of races since cpu_buffer is not calculated twice. Signed-off-by: Robert Richter LKML-Reference: <1249045084-3028-1-git-send-email-robert.richter@amd.com> Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 454e74e718cf..8786c350b4ca 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2997,15 +2997,12 @@ static void rb_advance_iter(struct ring_buffer_iter *iter) } static struct ring_buffer_event * -rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) +rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts) { - struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; struct buffer_page *reader; int nr_loops = 0; - cpu_buffer = buffer->buffers[cpu]; - again: /* * We repeat when a timestamp is encountered. It is possible @@ -3049,7 +3046,7 @@ rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) case RINGBUF_TYPE_DATA: if (ts) { *ts = cpu_buffer->read_stamp + event->time_delta; - ring_buffer_normalize_time_stamp(buffer, + ring_buffer_normalize_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu, ts); } return event; @@ -3168,7 +3165,7 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) local_irq_save(flags); if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(buffer, cpu, ts); + event = rb_buffer_peek(cpu_buffer, ts); if (event && event->type_len == RINGBUF_TYPE_PADDING) rb_advance_reader(cpu_buffer); if (dolock) @@ -3237,7 +3234,7 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) if (dolock) spin_lock(&cpu_buffer->reader_lock); - event = rb_buffer_peek(buffer, cpu, ts); + event = rb_buffer_peek(cpu_buffer, ts); if (event) rb_advance_reader(cpu_buffer); -- cgit v1.2.2 From 478142c39c8c2f5f63038e5f2224e6729406e587 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 9 Sep 2009 10:36:01 -0400 Subject: tracing: do not grab lock in wakeup latency function tracing The wakeup tracer, when enabled, has its own function tracer. It only traces the functions on the CPU where the task it is following is on. If a task is woken on one CPU but then migrates to another CPU before it wakes up, the latency tracer will then start tracing functions on the other CPU. To find which CPU the task is on, the wakeup function tracer performs a task_cpu(wakeup_task). But to make sure the task does not disappear it grabs the wakeup_lock, which is also taken when the task wakes up. By taking this lock, the function tracer does not need to worry about the task being freed as it checks its cpu. Jan Blunck found a problem with this approach on his 32 CPU box. When a task is being traced by the wakeup tracer, all functions take this lock. That means that on all 32 CPUs, each function call is taking this one lock to see if the task is on that CPU. This lock has just serialized all functions on all 32 CPUs. Needless to say, this caused major issues on that box. It would even lockup. This patch changes the wakeup latency to insert a probe on the migrate task tracepoint. When a task changes its CPU that it will run on, the probe will take note. Now the wakeup function tracer no longer needs to take the lock. It only compares the current CPU with a variable that holds the current CPU the task is on. We don't worry about races since it is OK to add or miss a function trace. Reported-by: Jan Blunck Tested-by: Jan Blunck Signed-off-by: Steven Rostedt --- kernel/trace/trace_sched_wakeup.c | 36 ++++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 14 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index ad69f105a7c6..cf43bdb1763a 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -24,6 +24,7 @@ static int __read_mostly tracer_enabled; static struct task_struct *wakeup_task; static int wakeup_cpu; +static int wakeup_current_cpu; static unsigned wakeup_prio = -1; static int wakeup_rt; @@ -56,33 +57,23 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) resched = ftrace_preempt_disable(); cpu = raw_smp_processor_id(); + if (cpu != wakeup_current_cpu) + goto out_enable; + data = tr->data[cpu]; disabled = atomic_inc_return(&data->disabled); if (unlikely(disabled != 1)) goto out; local_irq_save(flags); - __raw_spin_lock(&wakeup_lock); - - if (unlikely(!wakeup_task)) - goto unlock; - - /* - * The task can't disappear because it needs to - * wake up first, and we have the wakeup_lock. - */ - if (task_cpu(wakeup_task) != cpu) - goto unlock; trace_function(tr, ip, parent_ip, flags, pc); - unlock: - __raw_spin_unlock(&wakeup_lock); local_irq_restore(flags); out: atomic_dec(&data->disabled); - + out_enable: ftrace_preempt_enable(resched); } @@ -107,6 +98,14 @@ static int report_latency(cycle_t delta) return 1; } +static void probe_wakeup_migrate_task(struct task_struct *task, int cpu) +{ + if (task != wakeup_task) + return; + + wakeup_current_cpu = cpu; +} + static void notrace probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) @@ -244,6 +243,7 @@ probe_wakeup(struct rq *rq, struct task_struct *p, int success) __wakeup_reset(wakeup_trace); wakeup_cpu = task_cpu(p); + wakeup_current_cpu = wakeup_cpu; wakeup_prio = p->prio; wakeup_task = p; @@ -293,6 +293,13 @@ static void start_wakeup_tracer(struct trace_array *tr) goto fail_deprobe_wake_new; } + ret = register_trace_sched_migrate_task(probe_wakeup_migrate_task); + if (ret) { + pr_info("wakeup trace: Couldn't activate tracepoint" + " probe to kernel_sched_migrate_task\n"); + return; + } + wakeup_reset(tr); /* @@ -325,6 +332,7 @@ static void stop_wakeup_tracer(struct trace_array *tr) unregister_trace_sched_switch(probe_wakeup_sched_switch); unregister_trace_sched_wakeup_new(probe_wakeup); unregister_trace_sched_wakeup(probe_wakeup); + unregister_trace_sched_migrate_task(probe_wakeup_migrate_task); } static int __wakeup_tracer_init(struct trace_array *tr) -- cgit v1.2.2 From e0ab5f2daee1c7a6a387591bf37f0bad4e407112 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 10 Sep 2009 09:34:19 +0800 Subject: tracing: remove dead code Removes unreachable code. Signed-off-by: Li Zefan LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 22 ---------------------- 1 file changed, 22 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index fa1dccb579d5..536ae1d83629 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -120,14 +120,6 @@ struct print_entry { char buf[]; }; -#define TRACE_OLD_SIZE 88 - -struct trace_field_cont { - unsigned char type; - /* Temporary till we get rid of this completely */ - char buf[TRACE_OLD_SIZE - 1]; -}; - struct trace_mmiotrace_rw { struct trace_entry ent; struct mmiotrace_rw rw; @@ -509,20 +501,6 @@ static inline void __trace_stack(struct trace_array *tr, unsigned long flags, extern cycle_t ftrace_now(int cpu); -#ifdef CONFIG_CONTEXT_SWITCH_TRACER -typedef void -(*tracer_switch_func_t)(void *private, - void *__rq, - struct task_struct *prev, - struct task_struct *next); - -struct tracer_switch_ops { - tracer_switch_func_t func; - void *private; - struct tracer_switch_ops *next; -}; -#endif /* CONFIG_CONTEXT_SWITCH_TRACER */ - extern void trace_find_cmdline(int pid, char comm[]); #ifdef CONFIG_DYNAMIC_FTRACE -- cgit v1.2.2 From bd9cfca9cb71200dd82b320bba12540dc078f4e0 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 10 Sep 2009 09:34:19 +0800 Subject: tracing: format clean ups Fix white-space formatting. Signed-off-by: Li Zefan LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 536ae1d83629..86a0523b8e59 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -169,20 +169,20 @@ enum kmemtrace_type_id { struct kmemtrace_alloc_entry { struct trace_entry ent; - enum kmemtrace_type_id type_id; - unsigned long call_site; - const void *ptr; - size_t bytes_req; - size_t bytes_alloc; - gfp_t gfp_flags; - int node; + enum kmemtrace_type_id type_id; + unsigned long call_site; + const void *ptr; + size_t bytes_req; + size_t bytes_alloc; + gfp_t gfp_flags; + int node; }; struct kmemtrace_free_entry { struct trace_entry ent; - enum kmemtrace_type_id type_id; - unsigned long call_site; - const void *ptr; + enum kmemtrace_type_id type_id; + unsigned long call_site; + const void *ptr; }; struct syscall_trace_enter { @@ -203,7 +203,7 @@ struct syscall_trace_exit { * states when a trace occurs. These are: * IRQS_OFF - interrupts were disabled * IRQS_NOSUPPORT - arch does not support irqs_disabled_flags - * NEED_RESCED - reschedule is requested + * NEED_RESCHED - reschedule is requested * HARDIRQ - inside an interrupt handler * SOFTIRQ - inside a softirq handler */ -- cgit v1.2.2 From a5921c6c37d51ee2079ca3c69ea6f7b7384f5d87 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 10 Sep 2009 09:34:19 +0800 Subject: tracing: remove stats from struct tracer Remove unused field @stats from struct tracer. Signed-off-by: Li Zefan LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 86a0523b8e59..2163d185fe28 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -382,7 +382,6 @@ struct tracer { struct tracer *next; int print_max; struct tracer_flags *flags; - struct tracer_stat *stats; }; -- cgit v1.2.2 From 197e2eabc90c203d1086916b7f66694ba5fbb937 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 10 Sep 2009 09:34:19 +0800 Subject: tracing: move PRED macros to trace_events_filter.c Move DEFINE_COMPARISON_PRED() and DEFINE_EQUALITY_PRED() to kernel/trace/trace_events_filter.c Signed-off-by: Li Zefan LKML-Reference: <4AA8579B.4020706@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 41 -------------------------------------- kernel/trace/trace_events_filter.c | 41 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+), 41 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2163d185fe28..acaa68060ebc 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -800,47 +800,6 @@ filter_check_discard(struct ftrace_event_call *call, void *rec, return 0; } -#define DEFINE_COMPARISON_PRED(type) \ -static int filter_pred_##type(struct filter_pred *pred, void *event, \ - int val1, int val2) \ -{ \ - type *addr = (type *)(event + pred->offset); \ - type val = (type)pred->val; \ - int match = 0; \ - \ - switch (pred->op) { \ - case OP_LT: \ - match = (*addr < val); \ - break; \ - case OP_LE: \ - match = (*addr <= val); \ - break; \ - case OP_GT: \ - match = (*addr > val); \ - break; \ - case OP_GE: \ - match = (*addr >= val); \ - break; \ - default: \ - break; \ - } \ - \ - return match; \ -} - -#define DEFINE_EQUALITY_PRED(size) \ -static int filter_pred_##size(struct filter_pred *pred, void *event, \ - int val1, int val2) \ -{ \ - u##size *addr = (u##size *)(event + pred->offset); \ - u##size val = (u##size)pred->val; \ - int match; \ - \ - match = (val == *addr) ^ pred->not; \ - \ - return match; \ -} - extern struct mutex event_mutex; extern struct list_head ftrace_events; diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 93660fbbf629..23245785927f 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -121,6 +121,47 @@ struct filter_parse_state { } operand; }; +#define DEFINE_COMPARISON_PRED(type) \ +static int filter_pred_##type(struct filter_pred *pred, void *event, \ + int val1, int val2) \ +{ \ + type *addr = (type *)(event + pred->offset); \ + type val = (type)pred->val; \ + int match = 0; \ + \ + switch (pred->op) { \ + case OP_LT: \ + match = (*addr < val); \ + break; \ + case OP_LE: \ + match = (*addr <= val); \ + break; \ + case OP_GT: \ + match = (*addr > val); \ + break; \ + case OP_GE: \ + match = (*addr >= val); \ + break; \ + default: \ + break; \ + } \ + \ + return match; \ +} + +#define DEFINE_EQUALITY_PRED(size) \ +static int filter_pred_##size(struct filter_pred *pred, void *event, \ + int val1, int val2) \ +{ \ + u##size *addr = (u##size *)(event + pred->offset); \ + u##size val = (u##size)pred->val; \ + int match; \ + \ + match = (val == *addr) ^ pred->not; \ + \ + return match; \ +} + DEFINE_COMPARISON_PRED(s64); DEFINE_COMPARISON_PRED(u64); DEFINE_COMPARISON_PRED(s32); -- cgit v1.2.2 From 5e605b64a183a6c0e84cdb99a6f8acb1f8200437 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 5 Aug 2009 09:07:21 +0200 Subject: block: add blk-iopoll, a NAPI like approach for block devices This borrows some code from NAPI and implements a polled completion mode for block devices. The idea is the same as NAPI - instead of doing the command completion when the irq occurs, schedule a dedicated softirq in the hopes that we will complete more IO when the iopoll handler is invoked. Devices have a budget of commands assigned, and will stay in polled mode as long as they continue to consume their budget from the iopoll softirq handler. If they do not, the device is set back to interrupt completion mode. This patch holds the core bits for blk-iopoll, device driver support sold separately. Signed-off-by: Jens Axboe --- kernel/sysctl.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 58be76017fd0..0ed9fa6f322e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -92,6 +92,7 @@ extern int sysctl_nr_trim_pages; #ifdef CONFIG_RCU_TORTURE_TEST extern int rcutorture_runnable; #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */ +extern int blk_iopoll_enabled; /* Constants used for minimum and maximum */ #ifdef CONFIG_DETECT_SOFTLOCKUP @@ -990,7 +991,14 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dointvec, }, #endif - + { + .ctl_name = CTL_UNNUMBERED, + .procname = "blk_iopoll", + .data = &blk_iopoll_enabled, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt -- cgit v1.2.2 From 49ff590390a22c49e9063dcdec4cd5903127526b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 11 Sep 2009 00:30:26 -0400 Subject: tracing: add latency format to function_graph tracer While debugging something with the function_graph tracer, I found the need to see the preempt count of the traces. Unfortunately, since the function graph tracer has its own output formatting, it does not honor the latency-format option. This patch makes the function_graph tracer honor the latency-format option, but still keeps control of the output. But now we have the same details that the latency-format supplies. # tracer: function_graph # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / # |||| # CPU|||| DURATION FUNCTION CALLS # | |||| | | | | | | 3) d..1 1.333 us | idle_cpu(); 3) d.h1 | tick_check_idle() { 3) d.h1 0.550 us | tick_check_oneshot_broadcast(); 3) d.h1 | tick_nohz_stop_idle() { 3) d.h1 | ktime_get() { 3) d.h1 | ktime_get_ts() { Signed-off-by: Steven Rostedt --- kernel/trace/trace_functions_graph.c | 74 +++++++++++++++++++++++++++++++++--- 1 file changed, 68 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index b3749a2c3132..ee791a9650c5 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -364,6 +364,29 @@ print_graph_proc(struct trace_seq *s, pid_t pid) } +static enum print_line_t +print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) +{ + int hardirq, softirq; + + hardirq = entry->flags & TRACE_FLAG_HARDIRQ; + softirq = entry->flags & TRACE_FLAG_SOFTIRQ; + + if (!trace_seq_printf(s, " %c%c%c", + (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : + (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? + 'X' : '.', + (entry->flags & TRACE_FLAG_NEED_RESCHED) ? + 'N' : '.', + (hardirq && softirq) ? 'H' : + hardirq ? 'h' : softirq ? 's' : '.')) + return 0; + + if (entry->preempt_count) + return trace_seq_printf(s, "%x", entry->preempt_count); + return trace_seq_puts(s, "."); +} + /* If the pid changed since the last trace, output this event */ static enum print_line_t verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) @@ -521,6 +544,7 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr, if (ret == TRACE_TYPE_PARTIAL_LINE) return TRACE_TYPE_PARTIAL_LINE; } + /* Proc */ if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) { ret = print_graph_proc(s, pid); @@ -758,6 +782,13 @@ print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s, return TRACE_TYPE_PARTIAL_LINE; } + /* Latency format */ + if (trace_flags & TRACE_ITER_LATENCY_FMT) { + ret = print_graph_lat_fmt(s, ent); + if (ret == TRACE_TYPE_PARTIAL_LINE) + return TRACE_TYPE_PARTIAL_LINE; + } + return 0; } @@ -952,28 +983,59 @@ print_graph_function(struct trace_iterator *iter) return TRACE_TYPE_HANDLED; } +static void print_lat_header(struct seq_file *s) +{ + static const char spaces[] = " " /* 16 spaces */ + " " /* 4 spaces */ + " "; /* 17 spaces */ + int size = 0; + + if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) + size += 16; + if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) + size += 4; + if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) + size += 17; + + seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces); + seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces); + seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces); + seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces); + seq_printf(s, "#%.*s||| / \n", size, spaces); + seq_printf(s, "#%.*s|||| \n", size, spaces); +} + static void print_graph_headers(struct seq_file *s) { + int lat = trace_flags & TRACE_ITER_LATENCY_FMT; + + if (lat) + print_lat_header(s); + /* 1st line */ - seq_printf(s, "# "); + seq_printf(s, "#"); if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) seq_printf(s, " TIME "); if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) - seq_printf(s, "CPU"); + seq_printf(s, " CPU"); if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) - seq_printf(s, " TASK/PID "); + seq_printf(s, " TASK/PID "); + if (lat) + seq_printf(s, "||||"); if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) seq_printf(s, " DURATION "); seq_printf(s, " FUNCTION CALLS\n"); /* 2nd line */ - seq_printf(s, "# "); + seq_printf(s, "#"); if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) seq_printf(s, " | "); if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) - seq_printf(s, "| "); + seq_printf(s, " | "); if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) - seq_printf(s, " | | "); + seq_printf(s, " | | "); + if (lat) + seq_printf(s, "||||"); if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) seq_printf(s, " | | "); seq_printf(s, " | | | |\n"); -- cgit v1.2.2 From 48659d31195bb76d688e99dabd816c5472fb1656 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 11 Sep 2009 11:36:23 -0400 Subject: tracing: move tgid out of generic entry and into userstack The userstack trace required the recording of the tgid entry. Unfortunately, it was added to the generic entry where it wasted 4 bytes of every entry and was only used by one entry. This patch moves it out of the generic field and moves it into the only user (userstack_entry). Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 2 +- kernel/trace/trace.h | 1 + kernel/trace/trace_events.c | 5 +---- kernel/trace/trace_output.c | 2 +- 4 files changed, 4 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5c75deeefe30..1a37da2e8534 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -886,7 +886,6 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, entry->preempt_count = pc & 0xff; entry->pid = (tsk) ? tsk->pid : 0; - entry->tgid = (tsk) ? tsk->tgid : 0; entry->flags = #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | @@ -1068,6 +1067,7 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) return; entry = ring_buffer_event_data(event); + entry->tgid = current->tgid; memset(&entry->caller, 0, sizeof(entry->caller)); trace.nr_entries = 0; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index acaa68060ebc..b69697b4b846 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -101,6 +101,7 @@ struct stack_entry { struct userstack_entry { struct trace_entry ent; + unsigned int tgid; unsigned long caller[FTRACE_STACK_ENTRIES]; }; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 78b1ed230177..28d92027a93c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -86,7 +86,6 @@ int trace_define_common_fields(struct ftrace_event_call *call) __common_field(unsigned char, flags); __common_field(unsigned char, preempt_count); __common_field(int, pid); - __common_field(int, tgid); return ret; } @@ -572,13 +571,11 @@ static int trace_write_header(struct trace_seq *s) "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" - "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\n", FIELD(unsigned short, type), FIELD(unsigned char, flags), FIELD(unsigned char, preempt_count), - FIELD(int, pid), - FIELD(int, tgid)); + FIELD(int, pid)); } static ssize_t diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index e0c2545622e8..be34a6aa7e4d 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -407,7 +407,7 @@ seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s, * since individual threads might have already quit! */ rcu_read_lock(); - task = find_task_by_vpid(entry->ent.tgid); + task = find_task_by_vpid(entry->tgid); if (task) mm = get_task_mm(task); rcu_read_unlock(); -- cgit v1.2.2 From 637e7e864103a7a68c1ce43ada27dfc25c0d113f Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 11 Sep 2009 13:55:35 -0400 Subject: tracing: add lock depth to entries This patch adds the lock depth of the big kernel lock to the generic entry header. This way we can see the depth of the lock and help in removing the BKL. Example: # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| /_--=> lock-depth # |||||/ delay # cmd pid |||||| time | caller # \ / |||||| \ | / -0 2.N..3 5902255250us+: lock_acquire: read rcu_read_lock -0 2.N..3 5902255253us+: lock_release: rcu_read_lock -0 2dN..3 5902255257us+: lock_acquire: xtime_lock -0 2dN..4 5902255259us : lock_acquire: clocksource_lock -0 2dN..4 5902255261us+: lock_release: clocksource_lock Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 9 +++++---- kernel/trace/trace_events.c | 5 ++++- kernel/trace/trace_functions_graph.c | 16 ++++++++++++---- kernel/trace/trace_output.c | 10 +++++++++- 4 files changed, 30 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1a37da2e8534..3b918283cf94 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -886,6 +886,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, entry->preempt_count = pc & 0xff; entry->pid = (tsk) ? tsk->pid : 0; + entry->lock_depth = (tsk) ? tsk->lock_depth : 0; entry->flags = #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | @@ -1530,10 +1531,10 @@ static void print_lat_help_header(struct seq_file *m) seq_puts(m, "# | / _----=> need-resched \n"); seq_puts(m, "# || / _---=> hardirq/softirq \n"); seq_puts(m, "# ||| / _--=> preempt-depth \n"); - seq_puts(m, "# |||| / \n"); - seq_puts(m, "# ||||| delay \n"); - seq_puts(m, "# cmd pid ||||| time | caller \n"); - seq_puts(m, "# \\ / ||||| \\ | / \n"); + seq_puts(m, "# |||| /_--=> lock-depth \n"); + seq_puts(m, "# |||||/ delay \n"); + seq_puts(m, "# cmd pid |||||| time | caller \n"); + seq_puts(m, "# \\ / |||||| \\ | / \n"); } static void print_func_help_header(struct seq_file *m) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 28d92027a93c..975f324a07e7 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -86,6 +86,7 @@ int trace_define_common_fields(struct ftrace_event_call *call) __common_field(unsigned char, flags); __common_field(unsigned char, preempt_count); __common_field(int, pid); + __common_field(int, lock_depth); return ret; } @@ -571,11 +572,13 @@ static int trace_write_header(struct trace_seq *s) "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" + "\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n" "\n", FIELD(unsigned short, type), FIELD(unsigned char, flags), FIELD(unsigned char, preempt_count), - FIELD(int, pid)); + FIELD(int, pid), + FIELD(int, lock_depth)); } static ssize_t diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index ee791a9650c5..48af49374384 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -368,6 +368,7 @@ static enum print_line_t print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) { int hardirq, softirq; + int ret; hardirq = entry->flags & TRACE_FLAG_HARDIRQ; softirq = entry->flags & TRACE_FLAG_SOFTIRQ; @@ -382,6 +383,13 @@ print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) hardirq ? 'h' : softirq ? 's' : '.')) return 0; + if (entry->lock_depth < 0) + ret = trace_seq_putc(s, '.'); + else + ret = trace_seq_printf(s, "%d", entry->lock_depth); + if (!ret) + return 0; + if (entry->preempt_count) return trace_seq_printf(s, "%x", entry->preempt_count); return trace_seq_puts(s, "."); @@ -1001,8 +1009,8 @@ static void print_lat_header(struct seq_file *s) seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces); seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces); seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces); - seq_printf(s, "#%.*s||| / \n", size, spaces); - seq_printf(s, "#%.*s|||| \n", size, spaces); + seq_printf(s, "#%.*s||| / _-=> lock-depth \n", size, spaces); + seq_printf(s, "#%.*s|||| / \n", size, spaces); } static void print_graph_headers(struct seq_file *s) @@ -1021,7 +1029,7 @@ static void print_graph_headers(struct seq_file *s) if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) seq_printf(s, " TASK/PID "); if (lat) - seq_printf(s, "||||"); + seq_printf(s, "|||||"); if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) seq_printf(s, " DURATION "); seq_printf(s, " FUNCTION CALLS\n"); @@ -1035,7 +1043,7 @@ static void print_graph_headers(struct seq_file *s) if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) seq_printf(s, " | | "); if (lat) - seq_printf(s, "||||"); + seq_printf(s, "|||||"); if (tracer_flags.val & TRACE_GRAPH_PRINT_DURATION) seq_printf(s, " | | "); seq_printf(s, " | | | |\n"); diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index be34a6aa7e4d..29a370a45582 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -465,6 +465,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) { int hardirq, softirq; char comm[TASK_COMM_LEN]; + int ret; trace_find_cmdline(entry->pid, comm); hardirq = entry->flags & TRACE_FLAG_HARDIRQ; @@ -481,9 +482,16 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) hardirq ? 'h' : softirq ? 's' : '.')) return 0; + if (entry->lock_depth < 0) + ret = trace_seq_putc(s, '.'); + else + ret = trace_seq_printf(s, "%d", entry->lock_depth); + if (!ret) + return 0; + if (entry->preempt_count) return trace_seq_printf(s, "%x", entry->preempt_count); - return trace_seq_puts(s, "."); + return trace_seq_putc(s, '.'); } static unsigned long preempt_mark_thresh = 100; -- cgit v1.2.2 From f79e0258ea1f04d63db499479b5fb855dff6dbc5 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 11 Sep 2009 15:33:05 +0200 Subject: clocksource: Resolve cpu hotplug dead lock with TSC unstable, fix crash The watchdog timer is started after the watchdog clocksource and at least one watched clocksource have been registered. The clocksource work element watchdog_work is initialized just before the clocksource timer is started. This is too late for the clocksource_mark_unstable call from native_cpu_up. To fix this use a static initializer for watchdog_work. This resolves a boot crash reported by multiple people. Signed-off-by: Martin Schwidefsky Cc: Jens Axboe Cc: John Stultz LKML-Reference: <20090911153305.3fe9a361@skybase> Signed-off-by: Ingo Molnar --- kernel/time/clocksource.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index a0af4ffcb6e5..5697155f1868 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -123,10 +123,12 @@ static DEFINE_MUTEX(clocksource_mutex); static char override_name[32]; #ifdef CONFIG_CLOCKSOURCE_WATCHDOG +static void clocksource_watchdog_work(struct work_struct *work); + static LIST_HEAD(watchdog_list); static struct clocksource *watchdog; static struct timer_list watchdog_timer; -static struct work_struct watchdog_work; +static DECLARE_WORK(watchdog_work, clocksource_watchdog_work); static DEFINE_SPINLOCK(watchdog_lock); static cycle_t watchdog_last; static int watchdog_running; @@ -257,7 +259,6 @@ static inline void clocksource_start_watchdog(void) { if (watchdog_running || !watchdog || list_empty(&watchdog_list)) return; - INIT_WORK(&watchdog_work, clocksource_watchdog_work); init_timer(&watchdog_timer); watchdog_timer.function = clocksource_watchdog; watchdog_last = watchdog->read(watchdog); -- cgit v1.2.2 From f81c972d27c36729e65d4a815e3d7b782a540bad Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 11 Sep 2009 14:24:13 -0400 Subject: tracing: consolidate code between trace_output.c and trace_function_graph.c Both trace_output.c and trace_function_graph.c do basically the same thing to handle the printing of the latency-format. This patch moves the code into one function that both can use. Signed-off-by: Steven Rostedt --- kernel/trace/trace_functions_graph.c | 26 ++------------------------ kernel/trace/trace_output.c | 30 ++++++++++++++++++++++++------ kernel/trace/trace_output.h | 2 ++ 3 files changed, 28 insertions(+), 30 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 48af49374384..61f166707a08 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -367,32 +367,10 @@ print_graph_proc(struct trace_seq *s, pid_t pid) static enum print_line_t print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) { - int hardirq, softirq; - int ret; - - hardirq = entry->flags & TRACE_FLAG_HARDIRQ; - softirq = entry->flags & TRACE_FLAG_SOFTIRQ; - - if (!trace_seq_printf(s, " %c%c%c", - (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : - (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? - 'X' : '.', - (entry->flags & TRACE_FLAG_NEED_RESCHED) ? - 'N' : '.', - (hardirq && softirq) ? 'H' : - hardirq ? 'h' : softirq ? 's' : '.')) - return 0; - - if (entry->lock_depth < 0) - ret = trace_seq_putc(s, '.'); - else - ret = trace_seq_printf(s, "%d", entry->lock_depth); - if (!ret) + if (!trace_seq_putc(s, ' ')) return 0; - if (entry->preempt_count) - return trace_seq_printf(s, "%x", entry->preempt_count); - return trace_seq_puts(s, "."); + return trace_print_lat_fmt(s, entry); } /* If the pid changed since the last trace, output this event */ diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 29a370a45582..f572f44c6e1e 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -460,19 +460,23 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) return ret; } -static int -lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) +/** + * trace_print_lat_fmt - print the irq, preempt and lockdep fields + * @s: trace seq struct to write to + * @entry: The trace entry field from the ring buffer + * + * Prints the generic fields of irqs off, in hard or softirq, preempt + * count and lock depth. + */ +int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry) { int hardirq, softirq; - char comm[TASK_COMM_LEN]; int ret; - trace_find_cmdline(entry->pid, comm); hardirq = entry->flags & TRACE_FLAG_HARDIRQ; softirq = entry->flags & TRACE_FLAG_SOFTIRQ; - if (!trace_seq_printf(s, "%8.8s-%-5d %3d%c%c%c", - comm, entry->pid, cpu, + if (!trace_seq_printf(s, "%c%c%c", (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.', @@ -494,6 +498,20 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) return trace_seq_putc(s, '.'); } +static int +lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) +{ + char comm[TASK_COMM_LEN]; + + trace_find_cmdline(entry->pid, comm); + + if (!trace_seq_printf(s, "%8.8s-%-5d %3d", + comm, entry->pid, cpu)) + return 0; + + return trace_print_lat_fmt(s, entry); +} + static unsigned long preempt_mark_thresh = 100; static int diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h index d38bec4a9c30..9d91c72ba38b 100644 --- a/kernel/trace/trace_output.h +++ b/kernel/trace/trace_output.h @@ -26,6 +26,8 @@ extern struct trace_event *ftrace_find_event(int type); extern enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags); +extern int +trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry); /* used by module unregistering */ extern int __unregister_ftrace_event(struct trace_event *event); -- cgit v1.2.2 From b63f39ea50330f836e301ddda21c6a93dcf0d6a3 Mon Sep 17 00:00:00 2001 From: "jolsa@redhat.com" Date: Fri, 11 Sep 2009 17:29:27 +0200 Subject: tracing: create generic trace parser Create a "trace_parser" that can parse the user space input for separate words. struct trace_parser is the descriptor. Generic "trace_get_user" function that can be a helper to read multiple words passed in by user space. Signed-off-by: Jiri Olsa LKML-Reference: <1252682969-3366-2-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/trace/trace.h | 35 +++++++++++++++++ 2 files changed, 141 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3b918283cf94..45c3f0352d78 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -339,6 +339,112 @@ static struct { int trace_clock_id; +/* + * trace_parser_get_init - gets the buffer for trace parser + */ +int trace_parser_get_init(struct trace_parser *parser, int size) +{ + memset(parser, 0, sizeof(*parser)); + + parser->buffer = kmalloc(size, GFP_KERNEL); + if (!parser->buffer) + return 1; + + parser->size = size; + return 0; +} + +/* + * trace_parser_put - frees the buffer for trace parser + */ +void trace_parser_put(struct trace_parser *parser) +{ + kfree(parser->buffer); +} + +/* + * trace_get_user - reads the user input string separated by space + * (matched by isspace(ch)) + * + * For each string found the 'struct trace_parser' is updated, + * and the function returns. + * + * Returns number of bytes read. + * + * See kernel/trace/trace.h for 'struct trace_parser' details. + */ +int trace_get_user(struct trace_parser *parser, const char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char ch; + size_t read = 0; + ssize_t ret; + + if (!*ppos) + trace_parser_clear(parser); + + ret = get_user(ch, ubuf++); + if (ret) + goto out; + + read++; + cnt--; + + /* + * The parser is not finished with the last write, + * continue reading the user input without skipping spaces. + */ + if (!parser->cont) { + /* skip white space */ + while (cnt && isspace(ch)) { + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + } + + /* only spaces were written */ + if (isspace(ch)) { + *ppos += read; + ret = read; + goto out; + } + + parser->idx = 0; + } + + /* read the non-space input */ + while (cnt && !isspace(ch)) { + if (parser->idx < parser->size) + parser->buffer[parser->idx++] = ch; + else { + ret = -EINVAL; + goto out; + } + ret = get_user(ch, ubuf++); + if (ret) + goto out; + read++; + cnt--; + } + + /* We either got finished input or we have to wait for another call. */ + if (isspace(ch)) { + parser->buffer[parser->idx] = 0; + parser->cont = false; + } else { + parser->cont = true; + parser->buffer[parser->idx++] = ch; + } + + *ppos += read; + ret = read; + +out: + return ret; +} + ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) { int len; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index b69697b4b846..28247cecd955 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -615,6 +615,41 @@ static inline int ftrace_trace_task(struct task_struct *task) } #endif +/* + * struct trace_parser - servers for reading the user input separated by spaces + * @cont: set if the input is not complete - no final space char was found + * @buffer: holds the parsed user input + * @idx: user input lenght + * @size: buffer size + */ +struct trace_parser { + bool cont; + char *buffer; + unsigned idx; + unsigned size; +}; + +static inline bool trace_parser_loaded(struct trace_parser *parser) +{ + return (parser->idx != 0); +} + +static inline bool trace_parser_cont(struct trace_parser *parser) +{ + return parser->cont; +} + +static inline void trace_parser_clear(struct trace_parser *parser) +{ + parser->cont = false; + parser->idx = 0; +} + +extern int trace_parser_get_init(struct trace_parser *parser, int size); +extern void trace_parser_put(struct trace_parser *parser); +extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, + size_t cnt, loff_t *ppos); + /* * trace_iterator_flags is an enumeration that defines bit * positions into trace_flags that controls the output. -- cgit v1.2.2 From 489663644c35d50a20f58d468a7cbc705e6a29ce Mon Sep 17 00:00:00 2001 From: "jolsa@redhat.com" Date: Fri, 11 Sep 2009 17:29:28 +0200 Subject: tracing: trace parser support for set_event Convert the parsing of the file 'set_event' to use the generic trace_praser 'trace_get_user' function. Signed-off-by: Jiri Olsa LKML-Reference: <1252682969-3366-3-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 60 ++++++++++----------------------------------- 1 file changed, 13 insertions(+), 47 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 975f324a07e7..f46d14cefdec 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -230,11 +230,9 @@ static ssize_t ftrace_event_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { + struct trace_parser parser; size_t read = 0; - int i, set = 1; ssize_t ret; - char *buf; - char ch; if (!cnt || cnt < 0) return 0; @@ -243,60 +241,28 @@ ftrace_event_write(struct file *file, const char __user *ubuf, if (ret < 0) return ret; - ret = get_user(ch, ubuf++); - if (ret) - return ret; - read++; - cnt--; - - /* skip white space */ - while (cnt && isspace(ch)) { - ret = get_user(ch, ubuf++); - if (ret) - return ret; - read++; - cnt--; - } - - /* Only white space found? */ - if (isspace(ch)) { - file->f_pos += read; - ret = read; - return ret; - } - - buf = kmalloc(EVENT_BUF_SIZE+1, GFP_KERNEL); - if (!buf) + if (trace_parser_get_init(&parser, EVENT_BUF_SIZE + 1)) return -ENOMEM; - if (cnt > EVENT_BUF_SIZE) - cnt = EVENT_BUF_SIZE; + read = trace_get_user(&parser, ubuf, cnt, ppos); + + if (trace_parser_loaded((&parser))) { + int set = 1; - i = 0; - while (cnt && !isspace(ch)) { - if (!i && ch == '!') + if (*parser.buffer == '!') set = 0; - else - buf[i++] = ch; - ret = get_user(ch, ubuf++); + parser.buffer[parser.idx] = 0; + + ret = ftrace_set_clr_event(parser.buffer + !set, set); if (ret) - goto out_free; - read++; - cnt--; + goto out_put; } - buf[i] = 0; - - file->f_pos += read; - - ret = ftrace_set_clr_event(buf, set); - if (ret) - goto out_free; ret = read; - out_free: - kfree(buf); + out_put: + trace_parser_put(&parser); return ret; } -- cgit v1.2.2 From 689fd8b65d669b96d612ccc37d6fb87bf7ed6907 Mon Sep 17 00:00:00 2001 From: "jolsa@redhat.com" Date: Fri, 11 Sep 2009 17:29:29 +0200 Subject: tracing: trace parser support for function and graph Convert the writing to 'set_graph_function', 'set_ftrace_filter' and 'set_ftrace_notrace' to use the generic trace_parser 'trace_get_user' function. Removed FTRACE_ITER_CONT flag, since it's not needed after this change. Minor fix in set_graph_function display - g_show function. Signed-off-by: Jiri Olsa LKML-Reference: <1252682969-3366-4-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 150 ++++++++++++++------------------------------------ 1 file changed, 40 insertions(+), 110 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 8c804e24f96f..8b23d5670088 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1323,11 +1323,10 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) enum { FTRACE_ITER_FILTER = (1 << 0), - FTRACE_ITER_CONT = (1 << 1), - FTRACE_ITER_NOTRACE = (1 << 2), - FTRACE_ITER_FAILURES = (1 << 3), - FTRACE_ITER_PRINTALL = (1 << 4), - FTRACE_ITER_HASH = (1 << 5), + FTRACE_ITER_NOTRACE = (1 << 1), + FTRACE_ITER_FAILURES = (1 << 2), + FTRACE_ITER_PRINTALL = (1 << 3), + FTRACE_ITER_HASH = (1 << 4), }; #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ @@ -1337,8 +1336,7 @@ struct ftrace_iterator { int hidx; int idx; unsigned flags; - unsigned char buffer[FTRACE_BUFF_MAX+1]; - unsigned buffer_idx; + struct trace_parser parser; }; static void * @@ -1604,6 +1602,11 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable) if (!iter) return -ENOMEM; + if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { + kfree(iter); + return -ENOMEM; + } + mutex_lock(&ftrace_regex_lock); if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) @@ -2196,9 +2199,8 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos, int enable) { struct ftrace_iterator *iter; - char ch; - size_t read = 0; - ssize_t ret; + struct trace_parser *parser; + ssize_t ret, read; if (!cnt || cnt < 0) return 0; @@ -2211,72 +2213,23 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, } else iter = file->private_data; - if (!*ppos) { - iter->flags &= ~FTRACE_ITER_CONT; - iter->buffer_idx = 0; - } - - ret = get_user(ch, ubuf++); - if (ret) - goto out; - read++; - cnt--; - - /* - * If the parser haven't finished with the last write, - * continue reading the user input without skipping spaces. - */ - if (!(iter->flags & FTRACE_ITER_CONT)) { - /* skip white space */ - while (cnt && isspace(ch)) { - ret = get_user(ch, ubuf++); - if (ret) - goto out; - read++; - cnt--; - } + parser = &iter->parser; + read = trace_get_user(parser, ubuf, cnt, ppos); - /* only spaces were written */ - if (isspace(ch)) { - *ppos += read; - ret = read; - goto out; - } - - iter->buffer_idx = 0; - } - - while (cnt && !isspace(ch)) { - if (iter->buffer_idx < FTRACE_BUFF_MAX) - iter->buffer[iter->buffer_idx++] = ch; - else { - ret = -EINVAL; - goto out; - } - ret = get_user(ch, ubuf++); + if (trace_parser_loaded(parser) && + !trace_parser_cont(parser)) { + ret = ftrace_process_regex(parser->buffer, + parser->idx, enable); if (ret) goto out; - read++; - cnt--; - } - if (isspace(ch)) { - iter->buffer[iter->buffer_idx] = 0; - ret = ftrace_process_regex(iter->buffer, - iter->buffer_idx, enable); - if (ret) - goto out; - iter->buffer_idx = 0; - } else { - iter->flags |= FTRACE_ITER_CONT; - iter->buffer[iter->buffer_idx++] = ch; + trace_parser_clear(parser); } - *ppos += read; ret = read; - out: - mutex_unlock(&ftrace_regex_lock); + mutex_unlock(&ftrace_regex_lock); +out: return ret; } @@ -2381,6 +2334,7 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable) { struct seq_file *m = (struct seq_file *)file->private_data; struct ftrace_iterator *iter; + struct trace_parser *parser; mutex_lock(&ftrace_regex_lock); if (file->f_mode & FMODE_READ) { @@ -2390,9 +2344,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable) } else iter = file->private_data; - if (iter->buffer_idx) { - iter->buffer[iter->buffer_idx] = 0; - ftrace_match_records(iter->buffer, iter->buffer_idx, enable); + parser = &iter->parser; + if (trace_parser_loaded(parser)) { + parser->buffer[parser->idx] = 0; + ftrace_match_records(parser->buffer, parser->idx, enable); } mutex_lock(&ftrace_lock); @@ -2400,7 +2355,9 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable) ftrace_run_update_code(FTRACE_ENABLE_CALLS); mutex_unlock(&ftrace_lock); + trace_parser_put(parser); kfree(iter); + mutex_unlock(&ftrace_regex_lock); return 0; } @@ -2499,7 +2456,7 @@ static int g_show(struct seq_file *m, void *v) return 0; } - seq_printf(m, "%pf\n", v); + seq_printf(m, "%pf\n", (void *)*ptr); return 0; } @@ -2602,12 +2559,10 @@ static ssize_t ftrace_graph_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { - unsigned char buffer[FTRACE_BUFF_MAX+1]; + struct trace_parser parser; unsigned long *array; size_t read = 0; ssize_t ret; - int index = 0; - char ch; if (!cnt || cnt < 0) return 0; @@ -2625,51 +2580,26 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, } else array = file->private_data; - ret = get_user(ch, ubuf++); - if (ret) + if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { + ret = -ENOMEM; goto out; - read++; - cnt--; - - /* skip white space */ - while (cnt && isspace(ch)) { - ret = get_user(ch, ubuf++); - if (ret) - goto out; - read++; - cnt--; } - if (isspace(ch)) { - *ppos += read; - ret = read; - goto out; - } + read = trace_get_user(&parser, ubuf, cnt, ppos); - while (cnt && !isspace(ch)) { - if (index < FTRACE_BUFF_MAX) - buffer[index++] = ch; - else { - ret = -EINVAL; - goto out; - } - ret = get_user(ch, ubuf++); + if (trace_parser_loaded((&parser))) { + parser.buffer[parser.idx] = 0; + + /* we allow only one expression at a time */ + ret = ftrace_set_func(array, &ftrace_graph_count, + parser.buffer); if (ret) goto out; - read++; - cnt--; } - buffer[index] = 0; - - /* we allow only one expression at a time */ - ret = ftrace_set_func(array, &ftrace_graph_count, buffer); - if (ret) - goto out; - - file->f_pos += read; ret = read; out: + trace_parser_put(&parser); mutex_unlock(&graph_lock); return ret; -- cgit v1.2.2 From 41dfba4367109b92d92ec6e059be6950497d932f Mon Sep 17 00:00:00 2001 From: Carsten Emde Date: Sun, 13 Sep 2009 01:41:31 +0200 Subject: tracing: remove unused local variables in tracer probe functions When the nsecs_to_usecs() conversion in probe_wakeup_sched_switch() and check_critical_timing() was moved to a later stage in order to avoid unnecessary computing, it was overlooked to remove the original variables, assignments and comments.. Signed-off-by: Carsten Emde Signed-off-by: Steven Rostedt --- kernel/trace/trace_irqsoff.c | 12 +----------- kernel/trace/trace_sched_wakeup.c | 10 ---------- 2 files changed, 1 insertion(+), 21 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 5555b75a0d12..06f8ea9e4b9d 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -129,15 +129,10 @@ check_critical_timing(struct trace_array *tr, unsigned long parent_ip, int cpu) { - unsigned long latency, t0, t1; cycle_t T0, T1, delta; unsigned long flags; int pc; - /* - * usecs conversion is slow so we try to delay the conversion - * as long as possible: - */ T0 = data->preempt_timestamp; T1 = ftrace_now(cpu); delta = T1-T0; @@ -157,17 +152,12 @@ check_critical_timing(struct trace_array *tr, trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc); - latency = nsecs_to_usecs(delta); - if (data->critical_sequence != max_sequence) goto out_unlock; - tracing_max_latency = delta; - t0 = nsecs_to_usecs(T0); - t1 = nsecs_to_usecs(T1); - data->critical_end = parent_ip; + tracing_max_latency = delta; update_max_tr_single(tr, current, cpu); max_sequence++; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index cf43bdb1763a..6e1529bc6172 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -110,7 +110,6 @@ static void notrace probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) { - unsigned long latency = 0, t0 = 0, t1 = 0; struct trace_array_cpu *data; cycle_t T0, T1, delta; unsigned long flags; @@ -156,10 +155,6 @@ probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, trace_function(wakeup_trace, CALLER_ADDR0, CALLER_ADDR1, flags, pc); tracing_sched_switch_trace(wakeup_trace, prev, next, flags, pc); - /* - * usecs conversion is slow so we try to delay the conversion - * as long as possible: - */ T0 = data->preempt_timestamp; T1 = ftrace_now(cpu); delta = T1-T0; @@ -167,12 +162,7 @@ probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, if (!report_latency(delta)) goto out_unlock; - latency = nsecs_to_usecs(delta); - tracing_max_latency = delta; - t0 = nsecs_to_usecs(T0); - t1 = nsecs_to_usecs(T1); - update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); out_unlock: -- cgit v1.2.2 From b5130b1e7d3717d03ab1916b198bf0d49fa0a619 Mon Sep 17 00:00:00 2001 From: Carsten Emde Date: Sun, 13 Sep 2009 01:43:07 +0200 Subject: tracing: do not update tracing_max_latency when tracer is stopped The state of the function pair tracing_stop()/tracing_start() is correctly considered when tracer data are updated. However, the global and externally accessible variable tracing_max_latency is always updated - even when tracing is stopped. The update should only occur, if tracing was not stopped. Signed-off-by: Carsten Emde Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 5 +++++ kernel/trace/trace.h | 1 + kernel/trace/trace_irqsoff.c | 6 ++++-- kernel/trace/trace_sched_wakeup.c | 6 ++++-- 4 files changed, 14 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 45c3f0352d78..ef82a7fabf3b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -825,6 +825,11 @@ static void trace_init_cmdlines(void) cmdline_idx = 0; } +int is_tracing_stopped(void) +{ + return trace_stop_count; +} + /** * ftrace_off_permanent - disable all ftrace code permanently * diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 28247cecd955..4ad4e1ddcb9b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -461,6 +461,7 @@ void tracing_stop_sched_switch_record(void); void tracing_start_sched_switch_record(void); int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); +int is_tracing_stopped(void); extern unsigned long nsecs_to_usecs(unsigned long nsecs); diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 06f8ea9e4b9d..3aa7eaa2114c 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -157,8 +157,10 @@ check_critical_timing(struct trace_array *tr, data->critical_end = parent_ip; - tracing_max_latency = delta; - update_max_tr_single(tr, current, cpu); + if (likely(!is_tracing_stopped())) { + tracing_max_latency = delta; + update_max_tr_single(tr, current, cpu); + } max_sequence++; diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 6e1529bc6172..26185d727676 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -162,8 +162,10 @@ probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, if (!report_latency(delta)) goto out_unlock; - tracing_max_latency = delta; - update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); + if (likely(!is_tracing_stopped())) { + tracing_max_latency = delta; + update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); + } out_unlock: __wakeup_reset(wakeup_trace); -- cgit v1.2.2 From 558e6547e4b8a2b13608a24a9d3679802f91c4c7 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 24 Aug 2009 12:19:47 +0800 Subject: tracing/profile: fix profile_disable vs module_unload If the correspoding module is unloaded before ftrace_profile_disable() is called, event->profile_disable() won't be called, which can cause oops: # insmod trace-events-sample.ko # perf record -f -a -e sample:foo_bar sleep 3 & # sleep 1 # rmmod trace_events_sample # insmod trace-events-sample.ko OOPS! Signed-off-by: Li Zefan LKML-Reference: <4A9214E3.2070807@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_event_profile.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index 11ba5bb4ed0a..55a25c933d15 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -5,6 +5,7 @@ * */ +#include #include "trace.h" int ftrace_profile_enable(int event_id) @@ -14,7 +15,8 @@ int ftrace_profile_enable(int event_id) mutex_lock(&event_mutex); list_for_each_entry(event, &ftrace_events, list) { - if (event->id == event_id && event->profile_enable) { + if (event->id == event_id && event->profile_enable && + try_module_get(event->mod)) { ret = event->profile_enable(event); break; } @@ -32,6 +34,7 @@ void ftrace_profile_disable(int event_id) list_for_each_entry(event, &ftrace_events, list) { if (event->id == event_id) { event->profile_disable(event); + module_put(event->mod); break; } } -- cgit v1.2.2 From 0a1c49db8d91c538f104f8d70e560c6fdd589bd4 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 12 Sep 2009 19:17:15 -0400 Subject: tracing: use macros to create internal ftrace entry ring buffer structures The entries used by ftrace internal code (plugins) currently have their formats manually exported to userspace. That is, the format files in debugfs/tracing/events/ftrace/*/format are currently created by hand. This is a maintenance nightmare, and can easily become out of sync with what is actually shown. This patch uses the methodology of the TRACE_EVENT macros to build the structures so that their formats can be automated and this will keep the structures in sync with what users can see. This patch only changes the way the structures are created. Further patches will build off of this to automate the format files. Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 160 ++++---------------- kernel/trace/trace_entries.h | 342 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 369 insertions(+), 133 deletions(-) create mode 100644 kernel/trace/trace_entries.h (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 4ad4e1ddcb9b..d308195d40aa 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -42,150 +42,45 @@ enum trace_type { __TRACE_LAST_TYPE, }; -/* - * Function trace entry - function address and parent function addres: - */ -struct ftrace_entry { - struct trace_entry ent; - unsigned long ip; - unsigned long parent_ip; -}; - -/* Function call entry */ -struct ftrace_graph_ent_entry { - struct trace_entry ent; - struct ftrace_graph_ent graph_ent; +enum kmemtrace_type_id { + KMEMTRACE_TYPE_KMALLOC = 0, /* kmalloc() or kfree(). */ + KMEMTRACE_TYPE_CACHE, /* kmem_cache_*(). */ + KMEMTRACE_TYPE_PAGES, /* __get_free_pages() and friends. */ }; -/* Function return entry */ -struct ftrace_graph_ret_entry { - struct trace_entry ent; - struct ftrace_graph_ret ret; -}; extern struct tracer boot_tracer; -/* - * Context switch trace entry - which task (and prio) we switched from/to: - */ -struct ctx_switch_entry { - struct trace_entry ent; - unsigned int prev_pid; - unsigned char prev_prio; - unsigned char prev_state; - unsigned int next_pid; - unsigned char next_prio; - unsigned char next_state; - unsigned int next_cpu; -}; - -/* - * Special (free-form) trace entry: - */ -struct special_entry { - struct trace_entry ent; - unsigned long arg1; - unsigned long arg2; - unsigned long arg3; -}; - -/* - * Stack-trace entry: - */ +#undef __field +#define __field(type, item) type item; -#define FTRACE_STACK_ENTRIES 8 +#undef __array +#define __array(type, item, size) type item[size]; -struct stack_entry { - struct trace_entry ent; - unsigned long caller[FTRACE_STACK_ENTRIES]; -}; +#undef __dynamic_array +#define __dynamic_array(type, item) type item[]; -struct userstack_entry { - struct trace_entry ent; - unsigned int tgid; - unsigned long caller[FTRACE_STACK_ENTRIES]; -}; - -/* - * trace_printk entry: - */ -struct bprint_entry { - struct trace_entry ent; - unsigned long ip; - const char *fmt; - u32 buf[]; -}; - -struct print_entry { - struct trace_entry ent; - unsigned long ip; - char buf[]; -}; +#undef F_STRUCT +#define F_STRUCT(args...) args -struct trace_mmiotrace_rw { - struct trace_entry ent; - struct mmiotrace_rw rw; -}; - -struct trace_mmiotrace_map { - struct trace_entry ent; - struct mmiotrace_map map; -}; - -struct trace_boot_call { - struct trace_entry ent; - struct boot_trace_call boot_call; -}; - -struct trace_boot_ret { - struct trace_entry ent; - struct boot_trace_ret boot_ret; -}; - -#define TRACE_FUNC_SIZE 30 -#define TRACE_FILE_SIZE 20 -struct trace_branch { - struct trace_entry ent; - unsigned line; - char func[TRACE_FUNC_SIZE+1]; - char file[TRACE_FILE_SIZE+1]; - char correct; -}; - -struct hw_branch_entry { - struct trace_entry ent; - u64 from; - u64 to; -}; - -struct trace_power { - struct trace_entry ent; - struct power_trace state_data; -}; +#undef FTRACE_ENTRY +#define FTRACE_ENTRY(name, struct_name, id, tstruct, print) \ + struct struct_name { \ + struct trace_entry ent; \ + tstruct \ + } -enum kmemtrace_type_id { - KMEMTRACE_TYPE_KMALLOC = 0, /* kmalloc() or kfree(). */ - KMEMTRACE_TYPE_CACHE, /* kmem_cache_*(). */ - KMEMTRACE_TYPE_PAGES, /* __get_free_pages() and friends. */ -}; +#undef TP_ARGS +#define TP_ARGS(args...) args -struct kmemtrace_alloc_entry { - struct trace_entry ent; - enum kmemtrace_type_id type_id; - unsigned long call_site; - const void *ptr; - size_t bytes_req; - size_t bytes_alloc; - gfp_t gfp_flags; - int node; -}; +#undef FTRACE_ENTRY_DUP +#define FTRACE_ENTRY_DUP(name, name_struct, id, tstruct, printk) -struct kmemtrace_free_entry { - struct trace_entry ent; - enum kmemtrace_type_id type_id; - unsigned long call_site; - const void *ptr; -}; +#include "trace_entries.h" +/* + * syscalls are special, and need special handling, this is why + * they are not included in trace_entries.h + */ struct syscall_trace_enter { struct trace_entry ent; int nr; @@ -198,7 +93,6 @@ struct syscall_trace_exit { unsigned long ret; }; - /* * trace_flag_type is an enumeration that holds different * states when a trace occurs. These are: diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h new file mode 100644 index 000000000000..82c51fdca035 --- /dev/null +++ b/kernel/trace/trace_entries.h @@ -0,0 +1,342 @@ +/* + * This file defines the trace event structures that go into the ring + * buffer directly. They are created via macros so that changes for them + * appear in the format file. Using macros will automate this process. + * + * The macro used to create a ftrace data structure is: + * + * FTRACE_ENTRY( name, struct_name, id, structure, print ) + * + * @name: the name used the event name, as well as the name of + * the directory that holds the format file. + * + * @struct_name: the name of the structure that is created. + * + * @id: The event identifier that is used to detect what event + * this is from the ring buffer. + * + * @structure: the structure layout + * + * - __field( type, item ) + * This is equivalent to declaring + * type item; + * in the structure. + * - __array( type, item, size ) + * This is equivalent to declaring + * type item[size]; + * in the structure. + * + * @print: the print format shown to users in the format file. + */ + +/* + * Function trace entry - function address and parent function addres: + */ +FTRACE_ENTRY(function, ftrace_entry, + + TRACE_FN, + + F_STRUCT( + __field( unsigned long, ip ) + __field( unsigned long, parent_ip ) + ), + + F_printk(" %lx <-- %lx", __entry->ip, __entry->parent_ip) +); + +/* Function call entry */ +FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry, + + TRACE_GRAPH_ENT, + + F_STRUCT( + __field( struct ftrace_graph_ent, graph_ent ) + ), + + F_printk("--> %lx (%d)", __entry->graph_ent.func, __entry->depth) +); + +/* Function return entry */ +FTRACE_ENTRY(funcgraph_exit, ftrace_graph_ret_entry, + + TRACE_GRAPH_RET, + + F_STRUCT( + __field( struct ftrace_graph_ret, ret ) + ), + + F_printk("<-- %lx (%d) (start: %llx end: %llx) over: %d", + __entry->func, __entry->depth, + __entry->calltime, __entry->rettim, + __entrty->depth) +); + +/* + * Context switch trace entry - which task (and prio) we switched from/to: + * + * This is used for both wakeup and context switches. We only want + * to create one structure, but we need two outputs for it. + */ +#define FTRACE_CTX_FIELDS \ + __field( unsigned int, prev_pid ) \ + __field( unsigned char, prev_prio ) \ + __field( unsigned char, prev_state ) \ + __field( unsigned int, next_pid ) \ + __field( unsigned char, next_prio ) \ + __field( unsigned char, next_state ) \ + __field( unsigned int, next_cpu ) + +#if 0 +FTRACE_ENTRY_STRUCT_ONLY(ctx_switch_entry, + + F_STRUCT( + FTRACE_CTX_FIELDS + ) +); +#endif + +FTRACE_ENTRY(context_switch, ctx_switch_entry, + + TRACE_CTX, + + F_STRUCT( + FTRACE_CTX_FIELDS + ), + + F_printk(b"%u:%u:%u ==> %u:%u:%u [%03u]", + __entry->prev_pid, __entry->prev_prio, __entry->prev_state, + __entry->next_pid, __entry->next_prio, __entry->next_state, + __entry->next_cpu + ) +); + +/* + * FTRACE_ENTRY_DUP only creates the format file, it will not + * create another structure. + */ +FTRACE_ENTRY_DUP(wakeup, ctx_switch_entry, + + TRACE_WAKE, + + F_STRUCT( + FTRACE_CTX_FIELDS + ), + + F_printk("%u:%u:%u ==+ %u:%u:%u [%03u]", + __entry->prev_pid, __entry->prev_prio, __entry->prev_state, + __entry->next_pid, __entry->next_prio, __entry->next_state, + __entry->next_cpu + ) +); + +/* + * Special (free-form) trace entry: + */ +FTRACE_ENTRY(special, special_entry, + + TRACE_SPECIAL, + + F_STRUCT( + __field( unsigned long, arg1 ) + __field( unsigned long, arg2 ) + __field( unsigned long, arg3 ) + ), + + F_printk("(%08lx) (%08lx) (%08lx)", + __entry->arg1, __entry->arg2, __entry->arg3) +); + +/* + * Stack-trace entry: + */ + +#define FTRACE_STACK_ENTRIES 8 + +FTRACE_ENTRY(kernel_stack, stack_entry, + + TRACE_STACK, + + F_STRUCT( + __array( unsigned long, caller, FTRACE_STACK_ENTRIES ) + ), + + F_printk("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n" + "\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n", + __entry->caller[0], __entry->caller[1], __entry->caller[2], + __entry->caller[3], __entry->caller[4], __entry->caller[5], + __entry->caller[6], __entry->caller[7]) +); + +FTRACE_ENTRY(user_stack, userstack_entry, + + TRACE_USER_STACK, + + F_STRUCT( + __field( unsigned int, tgid ) + __array( unsigned long, caller, FTRACE_STACK_ENTRIES ) + ), + + F_printk("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n" + "\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n", + __entry->caller[0], __entry->caller[1], __entry->caller[2], + __entry->caller[3], __entry->caller[4], __entry->caller[5], + __entry->caller[6], __entry->caller[7]) +); + +/* + * trace_printk entry: + */ +FTRACE_ENTRY(bprint, bprint_entry, + + TRACE_BPRINT, + + F_STRUCT( + __field( unsigned long, ip ) + __field( const char *, fmt ) + __dynamic_array( u32, buf ) + ), + + F_printk("%08lx fmt:%p", + __entry->ip, __entry->fmt) +); + +FTRACE_ENTRY(print, print_entry, + + TRACE_PRINT, + + F_STRUCT( + __field( unsigned long, ip ) + __dynamic_array( char, buf ) + ), + + F_printk("%08lx %s", + __entry->ip, __entry->buf) +); + +FTRACE_ENTRY(mmiotrace_rw, trace_mmiotrace_rw, + + TRACE_MMIO_RW, + + F_STRUCT( + __field( struct mmiotrace_rw, rw ) + ), + + F_printk("%lx %lx %lx %d %lx %lx", + __entry->phs, __entry->value, __entry->pc, + __entry->map_id, __entry->opcode, __entry->width) +); + +FTRACE_ENTRY(mmiotrace_map, trace_mmiotrace_map, + + TRACE_MMIO_MAP, + + F_STRUCT( + __field( struct mmiotrace_map, map ) + ), + + F_printk("%lx %lx %lx %d %lx", + __entry->phs, __entry->virt, __entry->len, + __entry->map_id, __entry->opcode) +); + +FTRACE_ENTRY(boot_call, trace_boot_call, + + TRACE_BOOT_CALL, + + F_STRUCT( + __field( struct boot_trace_call, boot_call ) + ), + + F_printk("%d %s", __entry->caller, __entry->func) +); + +FTRACE_ENTRY(boot_ret, trace_boot_ret, + + TRACE_BOOT_RET, + + F_STRUCT( + __field( struct boot_trace_ret, boot_ret ) + ), + + F_printk("%s %d %lx", + __entry->func, __entry->result, __entry->duration) +); + +#define TRACE_FUNC_SIZE 30 +#define TRACE_FILE_SIZE 20 + +FTRACE_ENTRY(branch, trace_branch, + + TRACE_BRANCH, + + F_STRUCT( + __field( unsigned int, line ) + __array( char, func, TRACE_FUNC_SIZE+1 ) + __array( char, file, TRACE_FILE_SIZE+1 ) + __field( char, correct ) + ), + + F_printk("%u:%s:%s (%u)", + __entry->line, + __entry->func, __entry->file, __entry->correct) +); + +FTRACE_ENTRY(hw_branch, hw_branch_entry, + + TRACE_HW_BRANCHES, + + F_STRUCT( + __field( u64, from ) + __field( u64, to ) + ), + + F_printk("from: %llx to: %llx", __entry->from, __entry->to) +); + +FTRACE_ENTRY(power, trace_power, + + TRACE_POWER, + + F_STRUCT( + __field( struct power_trace, state_data ) + ), + + F_printk("%llx->%llx type:%u state:%u", + __entry->stamp, __entry->end, + __entry->type, __entry->state) +); + +FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry, + + TRACE_KMEM_ALLOC, + + F_STRUCT( + __field( enum kmemtrace_type_id, type_id ) + __field( unsigned long, call_site ) + __field( const void *, ptr ) + __field( size_t, bytes_req ) + __field( size_t, bytes_alloc ) + __field( gfp_t, gfp_flags ) + __field( int, node ) + ), + + F_printk("type:%u call_site:%lx ptr:%p req:%lu alloc:%lu" + " flags:%x node:%d", + __entry->type_id, __entry->call_site, __entry->ptr, + __entry->bytes_req, __entry->bytes_alloc, + __entry->gfp_flags, __entry->node) +); + +FTRACE_ENTRY(kmem_free, kmemtrace_free_entry, + + TRACE_KMEM_FREE, + + F_STRUCT( + __field( enum kmemtrace_type_id, type_id ) + __field( unsigned long, call_site ) + __field( const void *, ptr ) + ), + + F_printk("type:%u call_site:%lx ptr:%p", + __entry->type_id, __entry->call_site, __entry->ptr) +); -- cgit v1.2.2 From d73150943cf47b6cabcb4f4e52dd25975e820ae2 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 12 Sep 2009 19:22:23 -0400 Subject: tracing: show details of structures within the ftrace structures Some of the internal ftrace structures use structures within. The output of a field saying it is just a structure is useless for a format file. A binary reader of the ring buffer needs to know more about how the fields are broken up. This patch adds to the ftrace structure macros new fields to describe the structures inside a structure. Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 9 +++++++ kernel/trace/trace_entries.h | 64 +++++++++++++++++++++++++++++++++++++++----- 2 files changed, 66 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index d308195d40aa..b0d287d49a6d 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -53,9 +53,18 @@ extern struct tracer boot_tracer; #undef __field #define __field(type, item) type item; +#undef __field_struct +#define __field_struct(type, item) __field(type, item) + +#undef __field_desc +#define __field_desc(type, container, item) + #undef __array #define __array(type, item, size) type item[size]; +#undef __array_desc +#define __array_desc(type, container, item, size) + #undef __dynamic_array #define __dynamic_array(type, item) type item[]; diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index 82c51fdca035..c866d34e0144 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -26,6 +26,29 @@ * type item[size]; * in the structure. * + * * for structures within structures, the format of the internal + * structure is layed out. This allows the internal structure + * to be deciphered for the format file. Although these macros + * may become out of sync with the internal structure, they + * will create a compile error if it happens. Since the + * internel structures are just tracing helpers, this is not + * an issue. + * + * When an internal structure is used, it should use: + * + * __field_struct( type, item ) + * + * instead of __field. This will prevent it from being shown in + * the output file. The fields in the structure should use. + * + * __field_desc( type, container, item ) + * __array_desc( type, container, item, len ) + * + * type, item and len are the same as __field and __array, but + * container is added. This is the name of the item in + * __field_struct that this is describing. + * + * * @print: the print format shown to users in the format file. */ @@ -50,7 +73,9 @@ FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry, TRACE_GRAPH_ENT, F_STRUCT( - __field( struct ftrace_graph_ent, graph_ent ) + __field_struct( struct ftrace_graph_ent, graph_ent ) + __field_desc( unsigned long, graph_ent, func ) + __field_desc( int, graph_ent, depth ) ), F_printk("--> %lx (%d)", __entry->graph_ent.func, __entry->depth) @@ -62,7 +87,12 @@ FTRACE_ENTRY(funcgraph_exit, ftrace_graph_ret_entry, TRACE_GRAPH_RET, F_STRUCT( - __field( struct ftrace_graph_ret, ret ) + __field_struct( struct ftrace_graph_ret, ret ) + __field_desc( unsigned long, ret, func ) + __field_desc( unsigned long long, ret, calltime) + __field_desc( unsigned long long, ret, rettime ) + __field_desc( unsigned long, ret, overrun ) + __field_desc( int, ret, depth ) ), F_printk("<-- %lx (%d) (start: %llx end: %llx) over: %d", @@ -218,7 +248,13 @@ FTRACE_ENTRY(mmiotrace_rw, trace_mmiotrace_rw, TRACE_MMIO_RW, F_STRUCT( - __field( struct mmiotrace_rw, rw ) + __field_struct( struct mmiotrace_rw, rw ) + __field_desc( resource_size_t, rw, phys ) + __field_desc( unsigned long, rw, value ) + __field_desc( unsigned long, rw, pc ) + __field_desc( int, rw, map_id ) + __field_desc( unsigned char, rw, opcode ) + __field_desc( unsigned char, rw, width ) ), F_printk("%lx %lx %lx %d %lx %lx", @@ -231,7 +267,12 @@ FTRACE_ENTRY(mmiotrace_map, trace_mmiotrace_map, TRACE_MMIO_MAP, F_STRUCT( - __field( struct mmiotrace_map, map ) + __field_struct( struct mmiotrace_map, map ) + __field_desc( resource_size_t, map, phys ) + __field_desc( unsigned long, map, virt ) + __field_desc( unsigned long, map, len ) + __field_desc( int, map, map_id ) + __field_desc( unsigned char, map, opcode ) ), F_printk("%lx %lx %lx %d %lx", @@ -244,7 +285,9 @@ FTRACE_ENTRY(boot_call, trace_boot_call, TRACE_BOOT_CALL, F_STRUCT( - __field( struct boot_trace_call, boot_call ) + __field_struct( struct boot_trace_call, boot_call ) + __field_desc( pid_t, boot_call, caller ) + __array_desc( char, boot_call, func, KSYM_SYMBOL_LEN) ), F_printk("%d %s", __entry->caller, __entry->func) @@ -255,7 +298,10 @@ FTRACE_ENTRY(boot_ret, trace_boot_ret, TRACE_BOOT_RET, F_STRUCT( - __field( struct boot_trace_ret, boot_ret ) + __field_struct( struct boot_trace_ret, boot_ret ) + __array_desc( char, boot_ret, func, KSYM_SYMBOL_LEN) + __field_desc( int, boot_ret, result ) + __field_desc( unsigned long, boot_ret, duration ) ), F_printk("%s %d %lx", @@ -298,7 +344,11 @@ FTRACE_ENTRY(power, trace_power, TRACE_POWER, F_STRUCT( - __field( struct power_trace, state_data ) + __field_struct( struct power_trace, state_data ) + __field_desc( s64, state_data, stamp ) + __field_desc( s64, state_data, end ) + __field_desc( int, state_data, type ) + __field_desc( int, state_data, state ) ), F_printk("%llx->%llx type:%u state:%u", -- cgit v1.2.2 From 4e5292ea1ac0c2939e815e6c44fad3d8696ea281 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 12 Sep 2009 19:26:21 -0400 Subject: tracing: use the new trace_entries.h to create format files This patch changes the way the format files in debugfs/tracing/events/ftrace/*/format are created. It uses the new trace_entries.h file to automate the creation of the format files to ensure that they are always in sync with the actual structures. This is the same methodology used to create the format files for the TRACE_EVENT macro. This also updates the filter creation that was built on the creation of the format files. Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 12 ++- kernel/trace/trace_events.c | 1 + kernel/trace/trace_export.c | 241 +++++++++++++++++++++++--------------------- 3 files changed, 136 insertions(+), 118 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index b0d287d49a6d..86bcff94791a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -746,11 +747,12 @@ extern struct list_head ftrace_events; extern const char *__start___trace_bprintk_fmt[]; extern const char *__stop___trace_bprintk_fmt[]; -#undef TRACE_EVENT_FORMAT -#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ +#undef FTRACE_ENTRY +#define FTRACE_ENTRY(call, struct_name, id, tstruct, print) \ extern struct ftrace_event_call event_##call; -#undef TRACE_EVENT_FORMAT_NOFILTER -#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, tpfmt) -#include "trace_event_types.h" +#undef FTRACE_ENTRY_DUP +#define FTRACE_ENTRY_DUP(call, struct_name, id, tstruct, print) \ + FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print)) +#include "trace_entries.h" #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index f46d14cefdec..adbed124c3e7 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -21,6 +21,7 @@ #include "trace_output.h" +#undef TRACE_SYSTEM #define TRACE_SYSTEM "TRACE_SYSTEM" DEFINE_MUTEX(event_mutex); diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index df1bf6e48bb9..4cb29d84d73a 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -15,82 +15,163 @@ #include "trace_output.h" +#undef TRACE_SYSTEM +#define TRACE_SYSTEM ftrace -#undef TRACE_STRUCT -#define TRACE_STRUCT(args...) args +/* not needed for this file */ +#undef __field_struct +#define __field_struct(type, item) -extern void __bad_type_size(void); +#undef __field +#define __field(type, item) \ + ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ + "offset:%zu;\tsize:%zu;\n", \ + offsetof(typeof(field), item), \ + sizeof(field.item)); \ + if (!ret) \ + return 0; -#undef TRACE_FIELD -#define TRACE_FIELD(type, item, assign) \ - if (sizeof(type) != sizeof(field.item)) \ - __bad_type_size(); \ +#undef __field_desc +#define __field_desc(type, container, item) \ ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ - "offset:%u;\tsize:%u;\n", \ - (unsigned int)offsetof(typeof(field), item), \ - (unsigned int)sizeof(field.item)); \ + "offset:%zu;\tsize:%zu;\n", \ + offsetof(typeof(field), container.item), \ + sizeof(field.container.item)); \ if (!ret) \ return 0; +#undef __array +#define __array(type, item, len) \ + ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \ + "offset:%zu;\tsize:%zu;\n", \ + offsetof(typeof(field), item), \ + sizeof(field.item)); \ + if (!ret) \ + return 0; -#undef TRACE_FIELD_SPECIAL -#define TRACE_FIELD_SPECIAL(type_item, item, len, cmd) \ - ret = trace_seq_printf(s, "\tfield special:" #type_item ";\t" \ - "offset:%u;\tsize:%u;\n", \ - (unsigned int)offsetof(typeof(field), item), \ - (unsigned int)sizeof(field.item)); \ +#undef __array_desc +#define __array_desc(type, container, item, len) \ + ret = trace_seq_printf(s, "\tfield:" #type " " #item "[" #len "];\t" \ + "offset:%zu;\tsize:%zu;\n", \ + offsetof(typeof(field), container.item), \ + sizeof(field.container.item)); \ if (!ret) \ return 0; -#undef TRACE_FIELD_ZERO_CHAR -#define TRACE_FIELD_ZERO_CHAR(item) \ - ret = trace_seq_printf(s, "\tfield:char " #item ";\t" \ - "offset:%u;\tsize:0;\n", \ - (unsigned int)offsetof(typeof(field), item)); \ +#undef __dynamic_array +#define __dynamic_array(type, item) \ + ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ + "offset:%zu;\tsize:0;\n", \ + offsetof(typeof(field), item)); \ if (!ret) \ return 0; -#undef TRACE_FIELD_SIGN -#define TRACE_FIELD_SIGN(type, item, assign, is_signed) \ - TRACE_FIELD(type, item, assign) +#undef F_printk +#define F_printk(fmt, args...) "%s, %s\n", #fmt, __stringify(args) -#undef TP_RAW_FMT -#define TP_RAW_FMT(args...) args +#undef __entry +#define __entry REC -#undef TRACE_EVENT_FORMAT -#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ +#undef FTRACE_ENTRY +#define FTRACE_ENTRY(name, struct_name, id, tstruct, print) \ static int \ -ftrace_format_##call(struct ftrace_event_call *unused, \ - struct trace_seq *s) \ +ftrace_format_##name(struct ftrace_event_call *unused, \ + struct trace_seq *s) \ { \ - struct args field; \ - int ret; \ + struct struct_name field __attribute__((unused)); \ + int ret = 0; \ \ tstruct; \ \ - trace_seq_printf(s, "\nprint fmt: \"%s\"\n", tpfmt); \ + trace_seq_printf(s, "\nprint fmt: " print); \ \ return ret; \ } -#undef TRACE_EVENT_FORMAT_NOFILTER -#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \ - tpfmt) \ -static int \ -ftrace_format_##call(struct ftrace_event_call *unused, \ - struct trace_seq *s) \ +#undef FTRACE_ENTRY_DUP +#define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print) \ + FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) + +#include "trace_entries.h" + + +#undef __field +#define __field(type, item) \ + ret = trace_define_field(event_call, #type, #item, \ + offsetof(typeof(field), item), \ + sizeof(field.item), \ + is_signed_type(type), FILTER_OTHER); \ + if (ret) \ + return ret; + +#undef __field_desc +#define __field_desc(type, container, item) \ + ret = trace_define_field(event_call, #type, #item, \ + offsetof(typeof(field), \ + container.item), \ + sizeof(field.container.item), \ + is_signed_type(type), FILTER_OTHER); \ + if (ret) \ + return ret; + +#undef __array +#define __array(type, item, len) \ + BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \ + ret = trace_define_field(event_call, #type "[" #len "]", #item, \ + offsetof(typeof(field), item), \ + sizeof(field.item), 0, FILTER_OTHER); \ + if (ret) \ + return ret; + +#undef __array_desc +#define __array_desc(type, container, item, len) \ + BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \ + ret = trace_define_field(event_call, #type "[" #len "]", #item, \ + offsetof(typeof(field), \ + container.item), \ + sizeof(field.container.item), 0, \ + FILTER_OTHER); \ + if (ret) \ + return ret; + +#undef __dynamic_array +#define __dynamic_array(type, item) + +#undef FTRACE_ENTRY +#define FTRACE_ENTRY(name, struct_name, id, tstruct, print) \ +int \ +ftrace_define_fields_##name(struct ftrace_event_call *event_call) \ { \ - struct args field; \ + struct struct_name field; \ int ret; \ \ - tstruct; \ + ret = trace_define_common_fields(event_call); \ + if (ret) \ + return ret; \ \ - trace_seq_printf(s, "\nprint fmt: \"%s\"\n", tpfmt); \ + tstruct; \ \ return ret; \ } -#include "trace_event_types.h" +#include "trace_entries.h" + + +#undef __field +#define __field(type, item) + +#undef __field_desc +#define __field_desc(type, container, item) + +#undef __array +#define __array(type, item, len) + +#undef __array_desc +#define __array_desc(type, container, item, len) + +#undef __dynamic_array +#define __dynamic_array(type, item) + #undef TRACE_ZERO_CHAR #define TRACE_ZERO_CHAR(arg) @@ -117,16 +198,15 @@ ftrace_format_##call(struct ftrace_event_call *unused, \ #define TRACE_FIELD_SPECIAL(type_item, item, len, cmd) \ cmd; -#undef TRACE_EVENT_FORMAT -#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ -int ftrace_define_fields_##call(struct ftrace_event_call *event_call); \ +#undef FTRACE_ENTRY +#define FTRACE_ENTRY(call, struct_name, type, tstruct, print) \ static int ftrace_raw_init_event_##call(void); \ \ struct ftrace_event_call __used \ __attribute__((__aligned__(4))) \ __attribute__((section("_ftrace_events"))) event_##call = { \ .name = #call, \ - .id = proto, \ + .id = type, \ .system = __stringify(TRACE_SYSTEM), \ .raw_init = ftrace_raw_init_event_##call, \ .show_format = ftrace_format_##call, \ @@ -138,69 +218,4 @@ static int ftrace_raw_init_event_##call(void) \ return 0; \ } \ -#undef TRACE_EVENT_FORMAT_NOFILTER -#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \ - tpfmt) \ - \ -struct ftrace_event_call __used \ -__attribute__((__aligned__(4))) \ -__attribute__((section("_ftrace_events"))) event_##call = { \ - .name = #call, \ - .id = proto, \ - .system = __stringify(TRACE_SYSTEM), \ - .show_format = ftrace_format_##call, \ -}; - -#include "trace_event_types.h" - -#undef TRACE_FIELD -#define TRACE_FIELD(type, item, assign) \ - ret = trace_define_field(event_call, #type, #item, \ - offsetof(typeof(field), item), \ - sizeof(field.item), \ - is_signed_type(type), FILTER_OTHER); \ - if (ret) \ - return ret; - -#undef TRACE_FIELD_SPECIAL -#define TRACE_FIELD_SPECIAL(type, item, len, cmd) \ - ret = trace_define_field(event_call, #type "[" #len "]", #item, \ - offsetof(typeof(field), item), \ - sizeof(field.item), 0, FILTER_OTHER); \ - if (ret) \ - return ret; - -#undef TRACE_FIELD_SIGN -#define TRACE_FIELD_SIGN(type, item, assign, is_signed) \ - ret = trace_define_field(event_call, #type, #item, \ - offsetof(typeof(field), item), \ - sizeof(field.item), is_signed, \ - FILTER_OTHER); \ - if (ret) \ - return ret; - -#undef TRACE_FIELD_ZERO_CHAR -#define TRACE_FIELD_ZERO_CHAR(item) - -#undef TRACE_EVENT_FORMAT -#define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt) \ -int \ -ftrace_define_fields_##call(struct ftrace_event_call *event_call) \ -{ \ - struct args field; \ - int ret; \ - \ - ret = trace_define_common_fields(event_call); \ - if (ret) \ - return ret; \ - \ - tstruct; \ - \ - return ret; \ -} - -#undef TRACE_EVENT_FORMAT_NOFILTER -#define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct, \ - tpfmt) - -#include "trace_event_types.h" +#include "trace_entries.h" -- cgit v1.2.2 From 51df5fcbc1296a84cf1c093c6cb56d40ca3e697e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 12 Sep 2009 20:29:22 -0400 Subject: tracing: remove trace_event_types.h The macros in trace_entries.h have made the code in trace_event_types.h obsolete. The file is no longer used, so this patch removes it. Signed-off-by: Steven Rostedt --- kernel/trace/trace_event_types.h | 178 --------------------------------------- 1 file changed, 178 deletions(-) delete mode 100644 kernel/trace/trace_event_types.h (limited to 'kernel') diff --git a/kernel/trace/trace_event_types.h b/kernel/trace/trace_event_types.h deleted file mode 100644 index 6db005e12487..000000000000 --- a/kernel/trace/trace_event_types.h +++ /dev/null @@ -1,178 +0,0 @@ -#undef TRACE_SYSTEM -#define TRACE_SYSTEM ftrace - -/* - * We cheat and use the proto type field as the ID - * and args as the entry type (minus 'struct') - */ -TRACE_EVENT_FORMAT(function, TRACE_FN, ftrace_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, ip, ip) - TRACE_FIELD(unsigned long, parent_ip, parent_ip) - ), - TP_RAW_FMT(" %lx <-- %lx") -); - -TRACE_EVENT_FORMAT(funcgraph_entry, TRACE_GRAPH_ENT, - ftrace_graph_ent_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, graph_ent.func, func) - TRACE_FIELD(int, graph_ent.depth, depth) - ), - TP_RAW_FMT("--> %lx (%d)") -); - -TRACE_EVENT_FORMAT(funcgraph_exit, TRACE_GRAPH_RET, - ftrace_graph_ret_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, ret.func, func) - TRACE_FIELD(unsigned long long, ret.calltime, calltime) - TRACE_FIELD(unsigned long long, ret.rettime, rettime) - TRACE_FIELD(unsigned long, ret.overrun, overrun) - TRACE_FIELD(int, ret.depth, depth) - ), - TP_RAW_FMT("<-- %lx (%d)") -); - -TRACE_EVENT_FORMAT(wakeup, TRACE_WAKE, ctx_switch_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned int, prev_pid, prev_pid) - TRACE_FIELD(unsigned char, prev_prio, prev_prio) - TRACE_FIELD(unsigned char, prev_state, prev_state) - TRACE_FIELD(unsigned int, next_pid, next_pid) - TRACE_FIELD(unsigned char, next_prio, next_prio) - TRACE_FIELD(unsigned char, next_state, next_state) - TRACE_FIELD(unsigned int, next_cpu, next_cpu) - ), - TP_RAW_FMT("%u:%u:%u ==+ %u:%u:%u [%03u]") -); - -TRACE_EVENT_FORMAT(context_switch, TRACE_CTX, ctx_switch_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned int, prev_pid, prev_pid) - TRACE_FIELD(unsigned char, prev_prio, prev_prio) - TRACE_FIELD(unsigned char, prev_state, prev_state) - TRACE_FIELD(unsigned int, next_pid, next_pid) - TRACE_FIELD(unsigned char, next_prio, next_prio) - TRACE_FIELD(unsigned char, next_state, next_state) - TRACE_FIELD(unsigned int, next_cpu, next_cpu) - ), - TP_RAW_FMT("%u:%u:%u ==+ %u:%u:%u [%03u]") -); - -TRACE_EVENT_FORMAT_NOFILTER(special, TRACE_SPECIAL, special_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, arg1, arg1) - TRACE_FIELD(unsigned long, arg2, arg2) - TRACE_FIELD(unsigned long, arg3, arg3) - ), - TP_RAW_FMT("(%08lx) (%08lx) (%08lx)") -); - -/* - * Stack-trace entry: - */ - -/* #define FTRACE_STACK_ENTRIES 8 */ - -TRACE_EVENT_FORMAT(kernel_stack, TRACE_STACK, stack_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, caller[0], stack0) - TRACE_FIELD(unsigned long, caller[1], stack1) - TRACE_FIELD(unsigned long, caller[2], stack2) - TRACE_FIELD(unsigned long, caller[3], stack3) - TRACE_FIELD(unsigned long, caller[4], stack4) - TRACE_FIELD(unsigned long, caller[5], stack5) - TRACE_FIELD(unsigned long, caller[6], stack6) - TRACE_FIELD(unsigned long, caller[7], stack7) - ), - TP_RAW_FMT("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n" - "\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n") -); - -TRACE_EVENT_FORMAT(user_stack, TRACE_USER_STACK, userstack_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, caller[0], stack0) - TRACE_FIELD(unsigned long, caller[1], stack1) - TRACE_FIELD(unsigned long, caller[2], stack2) - TRACE_FIELD(unsigned long, caller[3], stack3) - TRACE_FIELD(unsigned long, caller[4], stack4) - TRACE_FIELD(unsigned long, caller[5], stack5) - TRACE_FIELD(unsigned long, caller[6], stack6) - TRACE_FIELD(unsigned long, caller[7], stack7) - ), - TP_RAW_FMT("\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n" - "\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n\t=> (%08lx)\n") -); - -TRACE_EVENT_FORMAT(bprint, TRACE_BPRINT, bprint_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, ip, ip) - TRACE_FIELD(char *, fmt, fmt) - TRACE_FIELD_ZERO_CHAR(buf) - ), - TP_RAW_FMT("%08lx (%d) fmt:%p %s") -); - -TRACE_EVENT_FORMAT(print, TRACE_PRINT, print_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned long, ip, ip) - TRACE_FIELD_ZERO_CHAR(buf) - ), - TP_RAW_FMT("%08lx (%d) fmt:%p %s") -); - -TRACE_EVENT_FORMAT(branch, TRACE_BRANCH, trace_branch, ignore, - TRACE_STRUCT( - TRACE_FIELD(unsigned int, line, line) - TRACE_FIELD_SPECIAL(char func[TRACE_FUNC_SIZE+1], func, - TRACE_FUNC_SIZE+1, func) - TRACE_FIELD_SPECIAL(char file[TRACE_FUNC_SIZE+1], file, - TRACE_FUNC_SIZE+1, file) - TRACE_FIELD(char, correct, correct) - ), - TP_RAW_FMT("%u:%s:%s (%u)") -); - -TRACE_EVENT_FORMAT(hw_branch, TRACE_HW_BRANCHES, hw_branch_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(u64, from, from) - TRACE_FIELD(u64, to, to) - ), - TP_RAW_FMT("from: %llx to: %llx") -); - -TRACE_EVENT_FORMAT(power, TRACE_POWER, trace_power, ignore, - TRACE_STRUCT( - TRACE_FIELD_SIGN(ktime_t, state_data.stamp, stamp, 1) - TRACE_FIELD_SIGN(ktime_t, state_data.end, end, 1) - TRACE_FIELD(int, state_data.type, type) - TRACE_FIELD(int, state_data.state, state) - ), - TP_RAW_FMT("%llx->%llx type:%u state:%u") -); - -TRACE_EVENT_FORMAT(kmem_alloc, TRACE_KMEM_ALLOC, kmemtrace_alloc_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(enum kmemtrace_type_id, type_id, type_id) - TRACE_FIELD(unsigned long, call_site, call_site) - TRACE_FIELD(const void *, ptr, ptr) - TRACE_FIELD(size_t, bytes_req, bytes_req) - TRACE_FIELD(size_t, bytes_alloc, bytes_alloc) - TRACE_FIELD(gfp_t, gfp_flags, gfp_flags) - TRACE_FIELD(int, node, node) - ), - TP_RAW_FMT("type:%u call_site:%lx ptr:%p req:%lu alloc:%lu" - " flags:%x node:%d") -); - -TRACE_EVENT_FORMAT(kmem_free, TRACE_KMEM_FREE, kmemtrace_free_entry, ignore, - TRACE_STRUCT( - TRACE_FIELD(enum kmemtrace_type_id, type_id, type_id) - TRACE_FIELD(unsigned long, call_site, call_site) - TRACE_FIELD(const void *, ptr, ptr) - ), - TP_RAW_FMT("type:%u call_site:%lx ptr:%p") -); - -#undef TRACE_SYSTEM -- cgit v1.2.2 From 60ba77022712c7cda0eda286154bae160446b24a Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 12 Sep 2009 23:34:04 -0400 Subject: tracing: add filter event logic to special, mmiotrace and boot tracers Now that the pluging tracers use macros to create the structures and automate the exporting of their formats to the format files, they also automatically get a filter file. This patch adds the code to implement the filter logic in the trace recordings. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 5 ++++- kernel/trace/trace_boot.c | 8 ++++++-- kernel/trace/trace_mmiotrace.c | 10 ++++++++-- 3 files changed, 18 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ef82a7fabf3b..fd52a19dd172 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1206,6 +1206,7 @@ ftrace_trace_special(void *__tr, unsigned long arg1, unsigned long arg2, unsigned long arg3, int pc) { + struct ftrace_event_call *call = &event_special; struct ring_buffer_event *event; struct trace_array *tr = __tr; struct ring_buffer *buffer = tr->buffer; @@ -1219,7 +1220,9 @@ ftrace_trace_special(void *__tr, entry->arg1 = arg1; entry->arg2 = arg2; entry->arg3 = arg3; - trace_buffer_unlock_commit(buffer, event, 0, pc); + + if (!filter_check_discard(call, entry, buffer, event)) + trace_buffer_unlock_commit(buffer, event, 0, pc); } void diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c index 19bfc75d467e..c21d5f3956ad 100644 --- a/kernel/trace/trace_boot.c +++ b/kernel/trace/trace_boot.c @@ -129,6 +129,7 @@ struct tracer boot_tracer __read_mostly = void trace_boot_call(struct boot_trace_call *bt, initcall_t fn) { + struct ftrace_event_call *call = &event_boot_call; struct ring_buffer_event *event; struct ring_buffer *buffer; struct trace_boot_call *entry; @@ -150,13 +151,15 @@ void trace_boot_call(struct boot_trace_call *bt, initcall_t fn) goto out; entry = ring_buffer_event_data(event); entry->boot_call = *bt; - trace_buffer_unlock_commit(buffer, event, 0, 0); + if (!filter_check_discard(call, entry, buffer, event)) + trace_buffer_unlock_commit(buffer, event, 0, 0); out: preempt_enable(); } void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn) { + struct ftrace_event_call *call = &event_boot_ret; struct ring_buffer_event *event; struct ring_buffer *buffer; struct trace_boot_ret *entry; @@ -175,7 +178,8 @@ void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn) goto out; entry = ring_buffer_event_data(event); entry->boot_ret = *bt; - trace_buffer_unlock_commit(buffer, event, 0, 0); + if (!filter_check_discard(call, entry, buffer, event)) + trace_buffer_unlock_commit(buffer, event, 0, 0); out: preempt_enable(); } diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index c4c9bbda53d3..0acd834659ed 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -307,6 +307,7 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data, struct mmiotrace_rw *rw) { + struct ftrace_event_call *call = &event_mmiotrace_rw; struct ring_buffer *buffer = tr->buffer; struct ring_buffer_event *event; struct trace_mmiotrace_rw *entry; @@ -320,7 +321,9 @@ static void __trace_mmiotrace_rw(struct trace_array *tr, } entry = ring_buffer_event_data(event); entry->rw = *rw; - trace_buffer_unlock_commit(buffer, event, 0, pc); + + if (!filter_check_discard(call, entry, buffer, event)) + trace_buffer_unlock_commit(buffer, event, 0, pc); } void mmio_trace_rw(struct mmiotrace_rw *rw) @@ -334,6 +337,7 @@ static void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data, struct mmiotrace_map *map) { + struct ftrace_event_call *call = &event_mmiotrace_map; struct ring_buffer *buffer = tr->buffer; struct ring_buffer_event *event; struct trace_mmiotrace_map *entry; @@ -347,7 +351,9 @@ static void __trace_mmiotrace_map(struct trace_array *tr, } entry = ring_buffer_event_data(event); entry->map = *map; - trace_buffer_unlock_commit(buffer, event, 0, pc); + + if (!filter_check_discard(call, entry, buffer, event)) + trace_buffer_unlock_commit(buffer, event, 0, pc); } void mmio_trace_mapping(struct mmiotrace_map *map) -- cgit v1.2.2 From 459ec28ab404d7afcd512ce9b855959ad301605a Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 13 Sep 2009 17:33:44 +0200 Subject: perf_counter: Allow mmap if paranoid checks are turned off Before: $ perf sched record -f sleep 1 Error: failed to mmap with 1 (Operation not permitted) After: $ perf sched record -f sleep 1 [ perf record: Captured and wrote 0.095 MB perf.data (~4161 samples) ] Note, this is only allowed if perfcounter_paranoid is set to the most permissive (non-default) value of -1. Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index e0d91fdf0c3c..667ab25ad3d5 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -2315,7 +2315,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) lock_limit >>= PAGE_SHIFT; locked = vma->vm_mm->locked_vm + extra; - if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) { + if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && + !capable(CAP_IPC_LOCK)) { ret = -EPERM; goto unlock; } -- cgit v1.2.2 From f977bb4937857994312fff4f9c2cad336a36a932 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 13 Sep 2009 18:15:54 +0200 Subject: perf_counter, sched: Add sched_stat_runtime tracepoint This allows more precise tracking of how the scheduler accounts (and acts upon) a task having spent N nanoseconds of CPU time. Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index aa7f84121016..a097e909e80f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -513,6 +513,7 @@ static void update_curr(struct cfs_rq *cfs_rq) if (entity_is_task(curr)) { struct task_struct *curtask = task_of(curr); + trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime); cpuacct_charge(curtask, delta_exec); account_group_exec_runtime(curtask, delta_exec); } -- cgit v1.2.2 From 08a408161749d2406f94f4e3d47cfdbc826ad1cc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 14 Sep 2009 09:31:35 -0400 Subject: ring-buffer: typecast cmpxchg to fix PowerPC warning The cmpxchg used by PowerPC does the following: ({ \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ (unsigned long)_n_, sizeof(*(ptr))); \ }) This does a type check of *ptr to both o and n. Unfortunately, the code in ring-buffer.c assigns longs to pointers and pointers to longs and causes a warning on PowerPC: ring_buffer.c: In function 'rb_head_page_set': ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c: In function 'rb_head_page_replace': ring_buffer.c:797: warning: initialization makes integer from pointer without a cast This patch adds the typecasts inside cmpxchg to annotate that a long is being cast to a pointer and a pointer is being casted to a long and this removes the PowerPC warnings. Reported-by: Stephen Rothwell Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 8786c350b4ca..6eef38923b07 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -701,8 +701,8 @@ static int rb_head_page_set(struct ring_buffer_per_cpu *cpu_buffer, val &= ~RB_FLAG_MASK; - ret = (unsigned long)cmpxchg(&list->next, - val | old_flag, val | new_flag); + ret = cmpxchg((unsigned long *)&list->next, + val | old_flag, val | new_flag); /* check if the reader took the page */ if ((ret & ~RB_FLAG_MASK) != val) @@ -794,7 +794,7 @@ static int rb_head_page_replace(struct buffer_page *old, val = *ptr & ~RB_FLAG_MASK; val |= RB_PAGE_HEAD; - ret = cmpxchg(ptr, val, &new->list); + ret = cmpxchg(ptr, val, (unsigned long)&new->list); return ret == val; } -- cgit v1.2.2 From ec827c7ece8901044e6b3f92aeea489be9e1bcf7 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 14 Sep 2009 10:50:23 -0400 Subject: tracing: add static to generated TRACE_EVENT functions Some of the generated functions used in the TRACE_EVENT macros are not declared static, but they are not global. Discovered by sparse. Reported-by: Jaswinder Singh Rajput Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index adbed124c3e7..0fa8f9faa61c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1154,7 +1154,7 @@ static int trace_module_notify(struct notifier_block *self, } #endif /* CONFIG_MODULES */ -struct notifier_block trace_module_nb = { +static struct notifier_block trace_module_nb = { .notifier_call = trace_module_notify, .priority = 0, }; -- cgit v1.2.2 From c16de8fd7a608aba8708dd056cf6e4d9462e800a Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 14 Sep 2009 15:51:39 +0800 Subject: tracing: fix F_printk() typos I found some typos in F_printk(), so I wrote compile-time check for it, and triggered some compile errors and warnings. I've fixed them on x86_32, but I have no x86_64 in my hand, so there may still be some compile warnings on 64bits. Signed-off-by: Li Zefan LKML-Reference: <4AADF60B.5070407@cn.fujitsu.com> [ tested on x86_64, and works fine ] Signed-off-by: Steven Rostedt --- kernel/trace/trace_entries.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index c866d34e0144..0c100958c642 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -78,7 +78,7 @@ FTRACE_ENTRY(funcgraph_entry, ftrace_graph_ent_entry, __field_desc( int, graph_ent, depth ) ), - F_printk("--> %lx (%d)", __entry->graph_ent.func, __entry->depth) + F_printk("--> %lx (%d)", __entry->func, __entry->depth) ); /* Function return entry */ @@ -97,8 +97,8 @@ FTRACE_ENTRY(funcgraph_exit, ftrace_graph_ret_entry, F_printk("<-- %lx (%d) (start: %llx end: %llx) over: %d", __entry->func, __entry->depth, - __entry->calltime, __entry->rettim, - __entrty->depth) + __entry->calltime, __entry->rettime, + __entry->depth) ); /* @@ -133,7 +133,7 @@ FTRACE_ENTRY(context_switch, ctx_switch_entry, FTRACE_CTX_FIELDS ), - F_printk(b"%u:%u:%u ==> %u:%u:%u [%03u]", + F_printk("%u:%u:%u ==> %u:%u:%u [%03u]", __entry->prev_pid, __entry->prev_prio, __entry->prev_state, __entry->next_pid, __entry->next_prio, __entry->next_state, __entry->next_cpu @@ -257,8 +257,8 @@ FTRACE_ENTRY(mmiotrace_rw, trace_mmiotrace_rw, __field_desc( unsigned char, rw, width ) ), - F_printk("%lx %lx %lx %d %lx %lx", - __entry->phs, __entry->value, __entry->pc, + F_printk("%lx %lx %lx %d %x %x", + (unsigned long)__entry->phys, __entry->value, __entry->pc, __entry->map_id, __entry->opcode, __entry->width) ); @@ -275,8 +275,8 @@ FTRACE_ENTRY(mmiotrace_map, trace_mmiotrace_map, __field_desc( unsigned char, map, opcode ) ), - F_printk("%lx %lx %lx %d %lx", - __entry->phs, __entry->virt, __entry->len, + F_printk("%lx %lx %lx %d %x", + (unsigned long)__entry->phys, __entry->virt, __entry->len, __entry->map_id, __entry->opcode) ); @@ -370,7 +370,7 @@ FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry, __field( int, node ) ), - F_printk("type:%u call_site:%lx ptr:%p req:%lu alloc:%lu" + F_printk("type:%u call_site:%lx ptr:%p req:%zi alloc:%zi" " flags:%x node:%d", __entry->type_id, __entry->call_site, __entry->ptr, __entry->bytes_req, __entry->bytes_alloc, -- cgit v1.2.2 From 05ffa2d02066c2cb169c02d5417308ee8ecab638 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 14 Sep 2009 15:54:52 +0800 Subject: ftrace: add compile-time check on F_printk() Make sure F_printk() has corrent format and args, and make sure changes in F_STRUCT() won't break F_printk(). Signed-off-by: Li Zefan LKML-Reference: <4AADF6CC.1060809@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_export.c | 45 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 41 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 4cb29d84d73a..2435d55947e6 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -22,6 +22,47 @@ #undef __field_struct #define __field_struct(type, item) +#undef __field +#define __field(type, item) type item; + +#undef __field_desc +#define __field_desc(type, container, item) type item; + +#undef __array +#define __array(type, item, size) type item[size]; + +#undef __array_desc +#define __array_desc(type, container, item, size) type item[size]; + +#undef __dynamic_array +#define __dynamic_array(type, item) type item[]; + +#undef F_STRUCT +#define F_STRUCT(args...) args + +#undef F_printk +#define F_printk(fmt, args...) fmt, args + +#undef FTRACE_ENTRY +#define FTRACE_ENTRY(name, struct_name, id, tstruct, print) \ +struct ____ftrace_##name { \ + tstruct \ +}; \ +static void __used ____ftrace_check_##name(void) \ +{ \ + struct ____ftrace_##name *__entry = NULL; \ + \ + /* force cmpile-time check on F_printk() */ \ + printk(print); \ +} + +#undef FTRACE_ENTRY_DUP +#define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print) \ + FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) + +#include "trace_entries.h" + + #undef __field #define __field(type, item) \ ret = trace_seq_printf(s, "\tfield:" #type " " #item ";\t" \ @@ -88,10 +129,6 @@ ftrace_format_##name(struct ftrace_event_call *unused, \ return ret; \ } -#undef FTRACE_ENTRY_DUP -#define FTRACE_ENTRY_DUP(name, struct_name, id, tstruct, print) \ - FTRACE_ENTRY(name, struct_name, id, PARAMS(tstruct), PARAMS(print)) - #include "trace_entries.h" -- cgit v1.2.2 From 20a58a77231c5f5f61470932503b889303e8d4f3 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 14 Sep 2009 15:55:18 +0800 Subject: tracing: remove some unused macros - remove FTRACE_ENTRY_STRUCT_ONLY() - remove TRACE_XXX() macros Signed-off-by: Li Zefan LKML-Reference: <4AADF6E6.3080606@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_entries.h | 9 --------- kernel/trace/trace_export.c | 26 -------------------------- 2 files changed, 35 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index 0c100958c642..a431748ddd6e 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -116,15 +116,6 @@ FTRACE_ENTRY(funcgraph_exit, ftrace_graph_ret_entry, __field( unsigned char, next_state ) \ __field( unsigned int, next_cpu ) -#if 0 -FTRACE_ENTRY_STRUCT_ONLY(ctx_switch_entry, - - F_STRUCT( - FTRACE_CTX_FIELDS - ) -); -#endif - FTRACE_ENTRY(context_switch, ctx_switch_entry, TRACE_CTX, diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 2435d55947e6..9753fcc61bc5 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -209,32 +209,6 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call) \ #undef __dynamic_array #define __dynamic_array(type, item) - -#undef TRACE_ZERO_CHAR -#define TRACE_ZERO_CHAR(arg) - -#undef TRACE_FIELD -#define TRACE_FIELD(type, item, assign)\ - entry->item = assign; - -#undef TRACE_FIELD -#define TRACE_FIELD(type, item, assign)\ - entry->item = assign; - -#undef TRACE_FIELD_SIGN -#define TRACE_FIELD_SIGN(type, item, assign, is_signed) \ - TRACE_FIELD(type, item, assign) - -#undef TP_CMD -#define TP_CMD(cmd...) cmd - -#undef TRACE_ENTRY -#define TRACE_ENTRY entry - -#undef TRACE_FIELD_SPECIAL -#define TRACE_FIELD_SPECIAL(type_item, item, len, cmd) \ - cmd; - #undef FTRACE_ENTRY #define FTRACE_ENTRY(call, struct_name, type, tstruct, print) \ static int ftrace_raw_init_event_##call(void); \ -- cgit v1.2.2 From 1f5a6b45416694ff8c0d04625f1a438a0e380add Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 14 Sep 2009 11:58:24 -0400 Subject: tracing: make testing syscall events a separate configuration Parag noticed that the number of event tests has increased tremendously: grep "Testing event" dmesg.31rc9 |wc -l 100 grep "Testing event" dmesg.31git |wc -l 1172 This is due to the testing of every syscall event when ftrace self test is enabled. This adds a bit more time to kernel boot up and can affect development by slowing down the time it takes between reboots. This option makes the testing of the syscall events into a separate config, to still be able to test most of ftrace internals at boot up but not have to wait for all the syscall events to be tested. The syscall event testing only tests the enabling and disabling of the trace point, since the syscalls are not executed. What really needs to be done is to somehow have a userspace tool test the syscall tracepoints as well. Reported-by: Parag Warudkar LKML-Reference: Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 12 ++++++++++++ kernel/trace/trace_events.c | 12 ++++++++++++ 2 files changed, 24 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 1ea0d1234f4a..aa002cef924c 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -469,6 +469,18 @@ config FTRACE_STARTUP_TEST functioning properly. It will do tests on all the configured tracers of ftrace. +config EVENT_TRACE_TEST_SYSCALLS + bool "Run selftest on syscall events" + depends on FTRACE_STARTUP_TEST + help + This option will also enable testing every syscall event. + It only enables the event and disables it and runs various loads + with the event enabled. This adds a bit more time for kernel boot + up since it runs this on every system call defined. + + TBD - enable a way to actually call the syscalls as we test their + events + config MMIOTRACE bool "Memory mapped IO tracing" depends on HAVE_MMIOTRACE_SUPPORT && PCI diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 0fa8f9faa61c..787f0fb0994e 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1326,6 +1326,18 @@ static __init void event_trace_self_tests(void) if (!call->regfunc) continue; +/* + * Testing syscall events here is pretty useless, but + * we still do it if configured. But this is time consuming. + * What we really need is a user thread to perform the + * syscalls as we test. + */ +#ifndef CONFIG_EVENT_TRACE_TEST_SYSCALLS + if (call->system && + strcmp(call->system, "syscalls") == 0) + continue; +#endif + pr_info("Testing event %s: ", call->name); /* -- cgit v1.2.2 From e681c9dd62fe8fcc5bba28a3ca3f7dc8be940206 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Wed, 8 Jul 2009 13:23:32 +0200 Subject: PM: Fix typo in label name s/Platofrm_finish/Platform_finish/ Although the same label name is used somewhere else in the file, this particular label was consistently typoed in all of its uses. Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 81d2e7464893..ec8202512b05 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -460,11 +460,11 @@ int hibernation_platform_enter(void) error = hibernation_ops->prepare(); if (error) - goto Platofrm_finish; + goto Platform_finish; error = disable_nonboot_cpus(); if (error) - goto Platofrm_finish; + goto Platform_finish; local_irq_disable(); sysdev_suspend(PMSG_HIBERNATE); @@ -476,7 +476,7 @@ int hibernation_platform_enter(void) * We don't need to reenable the nonboot CPUs or resume consoles, since * the system is going to be halted anyway. */ - Platofrm_finish: + Platform_finish: hibernation_ops->finish(); dpm_suspend_noirq(PMSG_RESTORE); -- cgit v1.2.2 From 4bb334353ebd821bc8eeabeb019eaac33c7307df Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 8 Jul 2009 13:23:51 +0200 Subject: PM/Hibernate: Rework shrinking of memory Rework swsusp_shrink_memory() so that it calls shrink_all_memory() just once to make some room for the image and then allocates memory to apply more pressure to the memory management subsystem, if necessary. Unfortunately, we don't seem to be able to drop shrink_all_memory() entirely just yet, because that would lead to huge performance regressions in some test cases. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek --- kernel/power/snapshot.c | 205 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 158 insertions(+), 47 deletions(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 523a451b45d3..a3a175fa0a46 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1066,69 +1066,180 @@ void swsusp_free(void) buffer = NULL; } +/* Helper functions used for the shrinking of memory. */ + +#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN) + /** - * swsusp_shrink_memory - Try to free as much memory as needed - * - * ... but do not OOM-kill anyone + * preallocate_image_pages - Allocate a number of pages for hibernation image + * @nr_pages: Number of page frames to allocate. + * @mask: GFP flags to use for the allocation. * - * Notice: all userland should be stopped before it is called, or - * livelock is possible. + * Return value: Number of page frames actually allocated */ +static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask) +{ + unsigned long nr_alloc = 0; + + while (nr_pages > 0) { + if (!alloc_image_page(mask)) + break; + nr_pages--; + nr_alloc++; + } -#define SHRINK_BITE 10000 -static inline unsigned long __shrink_memory(long tmp) + return nr_alloc; +} + +static unsigned long preallocate_image_memory(unsigned long nr_pages) +{ + return preallocate_image_pages(nr_pages, GFP_IMAGE); +} + +#ifdef CONFIG_HIGHMEM +static unsigned long preallocate_image_highmem(unsigned long nr_pages) { - if (tmp > SHRINK_BITE) - tmp = SHRINK_BITE; - return shrink_all_memory(tmp); + return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM); } +/** + * __fraction - Compute (an approximation of) x * (multiplier / base) + */ +static unsigned long __fraction(u64 x, u64 multiplier, u64 base) +{ + x *= multiplier; + do_div(x, base); + return (unsigned long)x; +} + +static unsigned long preallocate_highmem_fraction(unsigned long nr_pages, + unsigned long highmem, + unsigned long total) +{ + unsigned long alloc = __fraction(nr_pages, highmem, total); + + return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM); +} +#else /* CONFIG_HIGHMEM */ +static inline unsigned long preallocate_image_highmem(unsigned long nr_pages) +{ + return 0; +} + +static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages, + unsigned long highmem, + unsigned long total) +{ + return 0; +} +#endif /* CONFIG_HIGHMEM */ + +/** + * swsusp_shrink_memory - Make the kernel release as much memory as needed + * + * To create a hibernation image it is necessary to make a copy of every page + * frame in use. We also need a number of page frames to be free during + * hibernation for allocations made while saving the image and for device + * drivers, in case they need to allocate memory from their hibernation + * callbacks (these two numbers are given by PAGES_FOR_IO and SPARE_PAGES, + * respectively, both of which are rough estimates). To make this happen, we + * compute the total number of available page frames and allocate at least + * + * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + 2 * SPARE_PAGES + * + * of them, which corresponds to the maximum size of a hibernation image. + * + * If image_size is set below the number following from the above formula, + * the preallocation of memory is continued until the total number of saveable + * pages in the system is below the requested image size or it is impossible to + * allocate more memory, whichever happens first. + */ int swsusp_shrink_memory(void) { - long tmp; struct zone *zone; - unsigned long pages = 0; - unsigned int i = 0; - char *p = "-\\|/"; + unsigned long saveable, size, max_size, count, highmem, pages = 0; + unsigned long alloc, pages_highmem; struct timeval start, stop; + int error = 0; - printk(KERN_INFO "PM: Shrinking memory... "); + printk(KERN_INFO "PM: Shrinking memory... "); do_gettimeofday(&start); - do { - long size, highmem_size; - - highmem_size = count_highmem_pages(); - size = count_data_pages() + PAGES_FOR_IO + SPARE_PAGES; - tmp = size; - size += highmem_size; - for_each_populated_zone(zone) { - tmp += snapshot_additional_pages(zone); - if (is_highmem(zone)) { - highmem_size -= - zone_page_state(zone, NR_FREE_PAGES); - } else { - tmp -= zone_page_state(zone, NR_FREE_PAGES); - tmp += zone->lowmem_reserve[ZONE_NORMAL]; - } - } - if (highmem_size < 0) - highmem_size = 0; + /* Count the number of saveable data pages. */ + highmem = count_highmem_pages(); + saveable = count_data_pages(); - tmp += highmem_size; - if (tmp > 0) { - tmp = __shrink_memory(tmp); - if (!tmp) - return -ENOMEM; - pages += tmp; - } else if (size > image_size / PAGE_SIZE) { - tmp = __shrink_memory(size - (image_size / PAGE_SIZE)); - pages += tmp; - } - printk("\b%c", p[i++%4]); - } while (tmp > 0); + /* + * Compute the total number of page frames we can use (count) and the + * number of pages needed for image metadata (size). + */ + count = saveable; + saveable += highmem; + size = 0; + for_each_populated_zone(zone) { + size += snapshot_additional_pages(zone); + if (is_highmem(zone)) + highmem += zone_page_state(zone, NR_FREE_PAGES); + else + count += zone_page_state(zone, NR_FREE_PAGES); + } + count += highmem; + count -= totalreserve_pages; + + /* Compute the maximum number of saveable pages to leave in memory. */ + max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * SPARE_PAGES; + size = DIV_ROUND_UP(image_size, PAGE_SIZE); + if (size > max_size) + size = max_size; + /* + * If the maximum is not less than the current number of saveable pages + * in memory, we don't need to do anything more. + */ + if (size >= saveable) + goto out; + + /* + * Let the memory management subsystem know that we're going to need a + * large number of page frames to allocate and make it free some memory. + * NOTE: If this is not done, performance will be hurt badly in some + * test cases. + */ + shrink_all_memory(saveable - size); + + /* + * The number of saveable pages in memory was too high, so apply some + * pressure to decrease it. First, make room for the largest possible + * image and fail if that doesn't work. Next, try to decrease the size + * of the image as much as indicated by image_size using allocations + * from highmem and non-highmem zones separately. + */ + pages_highmem = preallocate_image_highmem(highmem / 2); + alloc = (count - max_size) - pages_highmem; + pages = preallocate_image_memory(alloc); + if (pages < alloc) { + error = -ENOMEM; + goto free_out; + } + size = max_size - size; + alloc = size; + size = preallocate_highmem_fraction(size, highmem, count); + pages_highmem += size; + alloc -= size; + pages += preallocate_image_memory(alloc); + pages += pages_highmem; + + free_out: + /* Release all of the preallocated page frames. */ + swsusp_free(); + + if (error) { + printk(KERN_CONT "\n"); + return error; + } + + out: do_gettimeofday(&stop); - printk("\bdone (%lu pages freed)\n", pages); + printk(KERN_CONT "done (preallocated %lu free pages)\n", pages); swsusp_show_speed(&start, &stop, pages, "Freed"); return 0; -- cgit v1.2.2 From 64a473cb74a88cb4991edf985d55a266e65292e1 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 8 Jul 2009 13:24:05 +0200 Subject: PM/Hibernate: Do not release preallocated memory unnecessarily (rev. 2) Since the hibernation code is now going to use allocations of memory to make enough room for the image, it can also use the page frames allocated at this stage as image page frames. The low-level hibernation code needs to be rearranged for this purpose, but it allows us to avoid freeing a great number of pages and allocating these same pages once again later, so it generally is worth doing. [rev. 2: Take highmem into account correctly.] Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 15 +++- kernel/power/power.h | 2 +- kernel/power/snapshot.c | 202 +++++++++++++++++++++++++++++++---------------- 3 files changed, 147 insertions(+), 72 deletions(-) (limited to 'kernel') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index ec8202512b05..04b3a83d686f 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -298,8 +298,8 @@ int hibernation_snapshot(int platform_mode) if (error) return error; - /* Free memory before shutting down devices. */ - error = swsusp_shrink_memory(); + /* Preallocate image memory before shutting down devices. */ + error = hibernate_preallocate_memory(); if (error) goto Close; @@ -315,6 +315,10 @@ int hibernation_snapshot(int platform_mode) /* Control returns here after successful restore */ Resume_devices: + /* We may need to release the preallocated image pages here. */ + if (error || !in_suspend) + swsusp_free(); + dpm_resume_end(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); resume_console(); @@ -578,7 +582,10 @@ int hibernate(void) goto Thaw; error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM); - if (in_suspend && !error) { + if (error) + goto Thaw; + + if (in_suspend) { unsigned int flags = 0; if (hibernation_mode == HIBERNATION_PLATFORM) @@ -590,8 +597,8 @@ int hibernate(void) power_down(); } else { pr_debug("PM: Image restored successfully.\n"); - swsusp_free(); } + Thaw: thaw_processes(); Finish: diff --git a/kernel/power/power.h b/kernel/power/power.h index 26d5a26f82e3..46c5a26630a3 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -74,7 +74,7 @@ extern asmlinkage int swsusp_arch_resume(void); extern int create_basic_memory_bitmaps(void); extern void free_basic_memory_bitmaps(void); -extern int swsusp_shrink_memory(void); +extern int hibernate_preallocate_memory(void); /** * Auxiliary structure used for reading the snapshot image data and diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index a3a175fa0a46..2b1a7bc24c91 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1033,6 +1033,25 @@ copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) static unsigned int nr_copy_pages; /* Number of pages needed for saving the original pfns of the image pages */ static unsigned int nr_meta_pages; +/* + * Numbers of normal and highmem page frames allocated for hibernation image + * before suspending devices. + */ +unsigned int alloc_normal, alloc_highmem; +/* + * Memory bitmap used for marking saveable pages (during hibernation) or + * hibernation image pages (during restore) + */ +static struct memory_bitmap orig_bm; +/* + * Memory bitmap used during hibernation for marking allocated page frames that + * will contain copies of saveable pages. During restore it is initially used + * for marking hibernation image pages, but then the set bits from it are + * duplicated in @orig_bm and it is released. On highmem systems it is next + * used for marking "safe" highmem pages, but it has to be reinitialized for + * this purpose. + */ +static struct memory_bitmap copy_bm; /** * swsusp_free - free pages allocated for the suspend. @@ -1064,6 +1083,8 @@ void swsusp_free(void) nr_meta_pages = 0; restore_pblist = NULL; buffer = NULL; + alloc_normal = 0; + alloc_highmem = 0; } /* Helper functions used for the shrinking of memory. */ @@ -1082,8 +1103,16 @@ static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask) unsigned long nr_alloc = 0; while (nr_pages > 0) { - if (!alloc_image_page(mask)) + struct page *page; + + page = alloc_image_page(mask); + if (!page) break; + memory_bm_set_bit(©_bm, page_to_pfn(page)); + if (PageHighMem(page)) + alloc_highmem++; + else + alloc_normal++; nr_pages--; nr_alloc++; } @@ -1135,7 +1164,47 @@ static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages, #endif /* CONFIG_HIGHMEM */ /** - * swsusp_shrink_memory - Make the kernel release as much memory as needed + * free_unnecessary_pages - Release preallocated pages not needed for the image + */ +static void free_unnecessary_pages(void) +{ + unsigned long save_highmem, to_free_normal, to_free_highmem; + + to_free_normal = alloc_normal - count_data_pages(); + save_highmem = count_highmem_pages(); + if (alloc_highmem > save_highmem) { + to_free_highmem = alloc_highmem - save_highmem; + } else { + to_free_highmem = 0; + to_free_normal -= save_highmem - alloc_highmem; + } + + memory_bm_position_reset(©_bm); + + while (to_free_normal > 0 && to_free_highmem > 0) { + unsigned long pfn = memory_bm_next_pfn(©_bm); + struct page *page = pfn_to_page(pfn); + + if (PageHighMem(page)) { + if (!to_free_highmem) + continue; + to_free_highmem--; + alloc_highmem--; + } else { + if (!to_free_normal) + continue; + to_free_normal--; + alloc_normal--; + } + memory_bm_clear_bit(©_bm, pfn); + swsusp_unset_page_forbidden(page); + swsusp_unset_page_free(page); + __free_page(page); + } +} + +/** + * hibernate_preallocate_memory - Preallocate memory for hibernation image * * To create a hibernation image it is necessary to make a copy of every page * frame in use. We also need a number of page frames to be free during @@ -1154,19 +1223,30 @@ static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages, * pages in the system is below the requested image size or it is impossible to * allocate more memory, whichever happens first. */ -int swsusp_shrink_memory(void) +int hibernate_preallocate_memory(void) { struct zone *zone; unsigned long saveable, size, max_size, count, highmem, pages = 0; - unsigned long alloc, pages_highmem; + unsigned long alloc, save_highmem, pages_highmem; struct timeval start, stop; - int error = 0; + int error; - printk(KERN_INFO "PM: Shrinking memory... "); + printk(KERN_INFO "PM: Preallocating image memory... "); do_gettimeofday(&start); + error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY); + if (error) + goto err_out; + + error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY); + if (error) + goto err_out; + + alloc_normal = 0; + alloc_highmem = 0; + /* Count the number of saveable data pages. */ - highmem = count_highmem_pages(); + save_highmem = count_highmem_pages(); saveable = count_data_pages(); /* @@ -1174,7 +1254,8 @@ int swsusp_shrink_memory(void) * number of pages needed for image metadata (size). */ count = saveable; - saveable += highmem; + saveable += save_highmem; + highmem = save_highmem; size = 0; for_each_populated_zone(zone) { size += snapshot_additional_pages(zone); @@ -1193,10 +1274,13 @@ int swsusp_shrink_memory(void) size = max_size; /* * If the maximum is not less than the current number of saveable pages - * in memory, we don't need to do anything more. + * in memory, allocate page frames for the image and we're done. */ - if (size >= saveable) + if (size >= saveable) { + pages = preallocate_image_highmem(save_highmem); + pages += preallocate_image_memory(saveable - pages); goto out; + } /* * Let the memory management subsystem know that we're going to need a @@ -1216,10 +1300,8 @@ int swsusp_shrink_memory(void) pages_highmem = preallocate_image_highmem(highmem / 2); alloc = (count - max_size) - pages_highmem; pages = preallocate_image_memory(alloc); - if (pages < alloc) { - error = -ENOMEM; - goto free_out; - } + if (pages < alloc) + goto err_out; size = max_size - size; alloc = size; size = preallocate_highmem_fraction(size, highmem, count); @@ -1228,21 +1310,24 @@ int swsusp_shrink_memory(void) pages += preallocate_image_memory(alloc); pages += pages_highmem; - free_out: - /* Release all of the preallocated page frames. */ - swsusp_free(); - - if (error) { - printk(KERN_CONT "\n"); - return error; - } + /* + * We only need as many page frames for the image as there are saveable + * pages in memory, but we have allocated more. Release the excessive + * ones now. + */ + free_unnecessary_pages(); out: do_gettimeofday(&stop); - printk(KERN_CONT "done (preallocated %lu free pages)\n", pages); - swsusp_show_speed(&start, &stop, pages, "Freed"); + printk(KERN_CONT "done (allocated %lu pages)\n", pages); + swsusp_show_speed(&start, &stop, pages, "Allocated"); return 0; + + err_out: + printk(KERN_CONT "\n"); + swsusp_free(); + return -ENOMEM; } #ifdef CONFIG_HIGHMEM @@ -1253,7 +1338,7 @@ int swsusp_shrink_memory(void) static unsigned int count_pages_for_highmem(unsigned int nr_highmem) { - unsigned int free_highmem = count_free_highmem_pages(); + unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem; if (free_highmem >= nr_highmem) nr_highmem = 0; @@ -1275,19 +1360,17 @@ count_pages_for_highmem(unsigned int nr_highmem) { return 0; } static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) { struct zone *zone; - unsigned int free = 0, meta = 0; + unsigned int free = alloc_normal; - for_each_zone(zone) { - meta += snapshot_additional_pages(zone); + for_each_zone(zone) if (!is_highmem(zone)) free += zone_page_state(zone, NR_FREE_PAGES); - } nr_pages += count_pages_for_highmem(nr_highmem); - pr_debug("PM: Normal pages needed: %u + %u + %u, available pages: %u\n", - nr_pages, PAGES_FOR_IO, meta, free); + pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n", + nr_pages, PAGES_FOR_IO, free); - return free > nr_pages + PAGES_FOR_IO + meta; + return free > nr_pages + PAGES_FOR_IO; } #ifdef CONFIG_HIGHMEM @@ -1309,7 +1392,7 @@ static inline int get_highmem_buffer(int safe_needed) */ static inline unsigned int -alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem) +alloc_highmem_pages(struct memory_bitmap *bm, unsigned int nr_highmem) { unsigned int to_alloc = count_free_highmem_pages(); @@ -1329,7 +1412,7 @@ alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem) static inline int get_highmem_buffer(int safe_needed) { return 0; } static inline unsigned int -alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; } +alloc_highmem_pages(struct memory_bitmap *bm, unsigned int n) { return 0; } #endif /* CONFIG_HIGHMEM */ /** @@ -1348,51 +1431,36 @@ static int swsusp_alloc(struct memory_bitmap *orig_bm, struct memory_bitmap *copy_bm, unsigned int nr_pages, unsigned int nr_highmem) { - int error; - - error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); - if (error) - goto Free; - - error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY); - if (error) - goto Free; + int error = 0; if (nr_highmem > 0) { error = get_highmem_buffer(PG_ANY); if (error) - goto Free; - - nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem); + goto err_out; + if (nr_highmem > alloc_highmem) { + nr_highmem -= alloc_highmem; + nr_pages += alloc_highmem_pages(copy_bm, nr_highmem); + } } - while (nr_pages-- > 0) { - struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD); - - if (!page) - goto Free; + if (nr_pages > alloc_normal) { + nr_pages -= alloc_normal; + while (nr_pages-- > 0) { + struct page *page; - memory_bm_set_bit(copy_bm, page_to_pfn(page)); + page = alloc_image_page(GFP_ATOMIC | __GFP_COLD); + if (!page) + goto err_out; + memory_bm_set_bit(copy_bm, page_to_pfn(page)); + } } + return 0; - Free: + err_out: swsusp_free(); - return -ENOMEM; + return error; } -/* Memory bitmap used for marking saveable pages (during suspend) or the - * suspend image pages (during resume) - */ -static struct memory_bitmap orig_bm; -/* Memory bitmap used on suspend for marking allocated pages that will contain - * the copies of saveable pages. During resume it is initially used for - * marking the suspend image pages, but then its set bits are duplicated in - * @orig_bm and it is released. Next, on systems with high memory, it may be - * used for marking "safe" highmem pages, but it has to be reinitialized for - * this purpose. - */ -static struct memory_bitmap copy_bm; - asmlinkage int swsusp_save(void) { unsigned int nr_pages, nr_highmem; -- cgit v1.2.2 From ef4aede3f10d82adef1fb044b565ba5f08f851e0 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 8 Jul 2009 13:24:12 +0200 Subject: PM/Hibernate: Do not try to allocate too much memory too hard (rev. 2) We want to avoid attempting to free too much memory too hard during hibernation, so estimate the minimum size of the image to use as the lower limit for preallocating memory. The approach here is based on the (experimental) observation that we can't free more page frames than the sum of: * global_page_state(NR_SLAB_RECLAIMABLE) * global_page_state(NR_ACTIVE_ANON) * global_page_state(NR_INACTIVE_ANON) * global_page_state(NR_ACTIVE_FILE) * global_page_state(NR_INACTIVE_FILE) minus * global_page_state(NR_FILE_MAPPED) Namely, if this number is subtracted from the number of saveable pages in the system, we get a good estimate of the minimum reasonable size of a hibernation image. Signed-off-by: Rafael J. Wysocki Acked-by: Wu Fengguang --- kernel/power/snapshot.c | 43 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 2b1a7bc24c91..0a06b114dd33 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1203,6 +1203,36 @@ static void free_unnecessary_pages(void) } } +/** + * minimum_image_size - Estimate the minimum acceptable size of an image + * @saveable: Number of saveable pages in the system. + * + * We want to avoid attempting to free too much memory too hard, so estimate the + * minimum acceptable size of a hibernation image to use as the lower limit for + * preallocating memory. + * + * We assume that the minimum image size should be proportional to + * + * [number of saveable pages] - [number of pages that can be freed in theory] + * + * where the second term is the sum of (1) reclaimable slab pages, (2) active + * and (3) inactive anonymouns pages, (4) active and (5) inactive file pages, + * minus mapped file pages. + */ +static unsigned long minimum_image_size(unsigned long saveable) +{ + unsigned long size; + + size = global_page_state(NR_SLAB_RECLAIMABLE) + + global_page_state(NR_ACTIVE_ANON) + + global_page_state(NR_INACTIVE_ANON) + + global_page_state(NR_ACTIVE_FILE) + + global_page_state(NR_INACTIVE_FILE) + - global_page_state(NR_FILE_MAPPED); + + return saveable <= size ? 0 : saveable - size; +} + /** * hibernate_preallocate_memory - Preallocate memory for hibernation image * @@ -1220,8 +1250,8 @@ static void free_unnecessary_pages(void) * * If image_size is set below the number following from the above formula, * the preallocation of memory is continued until the total number of saveable - * pages in the system is below the requested image size or it is impossible to - * allocate more memory, whichever happens first. + * pages in the system is below the requested image size or the minimum + * acceptable image size returned by minimum_image_size(), whichever is greater. */ int hibernate_preallocate_memory(void) { @@ -1282,6 +1312,11 @@ int hibernate_preallocate_memory(void) goto out; } + /* Estimate the minimum size of the image. */ + pages = minimum_image_size(saveable); + if (size < pages) + size = min_t(unsigned long, pages, max_size); + /* * Let the memory management subsystem know that we're going to need a * large number of page frames to allocate and make it free some memory. @@ -1294,8 +1329,8 @@ int hibernate_preallocate_memory(void) * The number of saveable pages in memory was too high, so apply some * pressure to decrease it. First, make room for the largest possible * image and fail if that doesn't work. Next, try to decrease the size - * of the image as much as indicated by image_size using allocations - * from highmem and non-highmem zones separately. + * of the image as much as indicated by 'size' using allocations from + * highmem and non-highmem zones separately. */ pages_highmem = preallocate_image_highmem(highmem / 2); alloc = (count - max_size) - pages_highmem; -- cgit v1.2.2 From 98e73dc5d2dadfcb95305ad71ac9239f4e361870 Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Wed, 22 Jul 2009 00:36:56 +0200 Subject: PM / Hibernate / Memory hotplug: Always use for_each_populated_zone() Use for_each_populated_zone() instead of for_each_zone() in hibernation code. This fixes a bug on s390, where we allow both config options HIBERNATION and MEMORY_HOTPLUG, so that we also have a ZONE_MOVABLE here. We only allow hibernation if no memory hotplug operation was performed, so in fact both features can only be used exclusively, but this way we don't need 2 differently configured (distribution) kernels. If we have an unpopulated ZONE_MOVABLE, we allow hibernation but run into a BUG_ON() in memory_bm_test/set/clear_bit() because hibernation code iterates through all zones, not only the populated zones, in several places. For example, swsusp_free() does for_each_zone() and then checks for pfn_valid(), which is true even if the zone is not populated, resulting in a BUG_ON() later because the pfn cannot be found in the memory bitmap. Replacing all occurences of for_each_zone() in hibernation code with for_each_populated_zone() would fix this issue. [rjw: Rebased on top of linux-next hibernation patches.] Signed-off-by: Gerald Schaefer Acked-by: KOSAKI Motohiro Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 0a06b114dd33..bf06658f2052 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -853,7 +853,7 @@ static unsigned int count_highmem_pages(void) struct zone *zone; unsigned int n = 0; - for_each_zone(zone) { + for_each_populated_zone(zone) { unsigned long pfn, max_zone_pfn; if (!is_highmem(zone)) @@ -916,7 +916,7 @@ static unsigned int count_data_pages(void) unsigned long pfn, max_zone_pfn; unsigned int n = 0; - for_each_zone(zone) { + for_each_populated_zone(zone) { if (is_highmem(zone)) continue; @@ -1010,7 +1010,7 @@ copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm) struct zone *zone; unsigned long pfn; - for_each_zone(zone) { + for_each_populated_zone(zone) { unsigned long max_zone_pfn; mark_free_pages(zone); @@ -1065,7 +1065,7 @@ void swsusp_free(void) struct zone *zone; unsigned long pfn, max_zone_pfn; - for_each_zone(zone) { + for_each_populated_zone(zone) { max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if (pfn_valid(pfn)) { @@ -1397,7 +1397,7 @@ static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) struct zone *zone; unsigned int free = alloc_normal; - for_each_zone(zone) + for_each_populated_zone(zone) if (!is_highmem(zone)) free += zone_page_state(zone, NR_FREE_PAGES); @@ -1688,7 +1688,7 @@ static int mark_unsafe_pages(struct memory_bitmap *bm) unsigned long pfn, max_zone_pfn; /* Clear page flags */ - for_each_zone(zone) { + for_each_populated_zone(zone) { max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages; for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) if (pfn_valid(pfn)) -- cgit v1.2.2 From 8de0307326be94148436082a9abf365da8e3c66d Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Wed, 22 Jul 2009 19:56:10 +0200 Subject: PM: Trivial fixes Fix the definition of BM_BITS_PER_BLOCK and kerneldoc description of create_bm_block_list(). [rjw: Added changelog.] Signed-off-by: Wu Fengguang Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index bf06658f2052..97955b0e44f4 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -233,7 +233,7 @@ static void *chain_alloc(struct chain_allocator *ca, unsigned int size) #define BM_END_OF_MAP (~0UL) -#define BM_BITS_PER_BLOCK (PAGE_SIZE << 3) +#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE) struct bm_block { struct list_head hook; /* hook into a list of bitmap blocks */ @@ -275,7 +275,7 @@ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free); /** * create_bm_block_list - create a list of block bitmap objects - * @nr_blocks - number of blocks to allocate + * @pages - number of pages to track * @list - list to put the allocated blocks into * @ca - chain allocator to be used for allocating memory */ -- cgit v1.2.2 From e6c733050faa93ce616bfedccd279ab12cffdd7b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 14 Sep 2009 19:51:11 +0200 Subject: clocksource: clocksource_select must be called with mutex locked The callers of clocksource_select must hold clocksource_mutex to protect the clocksource_list. Signed-off-by: Thomas Gleixner LKML-Reference: Cc: Martin Schwidefsky --- kernel/time/clocksource.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 5697155f1868..2c2e5ba1453d 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -471,7 +471,9 @@ static void clocksource_select(void) static int __init clocksource_done_booting(void) { finished_booting = 1; + mutex_lock(&clocksource_mutex); clocksource_select(); + mutex_unlock(&clocksource_mutex); return 0; } fs_initcall(clocksource_done_booting); -- cgit v1.2.2 From 54a6bc0b071c50150bc6d1da16c2cd9a963e288c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 14 Sep 2009 19:49:02 +0200 Subject: clocksource: Delay clocksource down rating to late boot The down rating of clock sources in the early boot process via the clock source watchdog mechanism can happen way before the per cpu event queues are initialized. This leads to a boot crash on x86 when the TSC is marked unstable in the SMP bring up. The selection of a clock source for time keeping happens in the late boot process so we can safely delay the list manipulation until clocksource_done_booting() is called. Signed-off-by: Thomas Gleixner LKML-Reference: Cc: Martin Schwidefsky --- kernel/time/clocksource.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 2c2e5ba1453d..09113347d328 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -121,6 +121,7 @@ static struct clocksource *curr_clocksource; static LIST_HEAD(clocksource_list); static DEFINE_MUTEX(clocksource_mutex); static char override_name[32]; +static int finished_booting; #ifdef CONFIG_CLOCKSOURCE_WATCHDOG static void clocksource_watchdog_work(struct work_struct *work); @@ -155,7 +156,8 @@ static void __clocksource_unstable(struct clocksource *cs) { cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); cs->flags |= CLOCK_SOURCE_UNSTABLE; - schedule_work(&watchdog_work); + if (finished_booting) + schedule_work(&watchdog_work); } static void clocksource_unstable(struct clocksource *cs, int64_t delta) @@ -207,7 +209,8 @@ static void clocksource_watchdog(unsigned long data) /* Clocksource already marked unstable? */ if (cs->flags & CLOCK_SOURCE_UNSTABLE) { - schedule_work(&watchdog_work); + if (finished_booting) + schedule_work(&watchdog_work); continue; } @@ -380,6 +383,7 @@ static void clocksource_enqueue_watchdog(struct clocksource *cs) static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { } static inline void clocksource_resume_watchdog(void) { } +static inline int clocksource_watchdog_kthread(void *data) { return 0; } #endif /* CONFIG_CLOCKSOURCE_WATCHDOG */ @@ -415,8 +419,6 @@ void clocksource_touch_watchdog(void) #ifdef CONFIG_GENERIC_TIME -static int finished_booting; - /** * clocksource_select - Select the best clocksource available * @@ -461,6 +463,12 @@ static void clocksource_select(void) } } +#else /* CONFIG_GENERIC_TIME */ + +static inline void clocksource_select(void) { } + +#endif + /* * clocksource_done_booting - Called near the end of core bootup * @@ -471,6 +479,12 @@ static void clocksource_select(void) static int __init clocksource_done_booting(void) { finished_booting = 1; + + /* + * Run the watchdog first to eliminate unstable clock sources + */ + clocksource_watchdog_kthread(NULL); + mutex_lock(&clocksource_mutex); clocksource_select(); mutex_unlock(&clocksource_mutex); @@ -478,12 +492,6 @@ static int __init clocksource_done_booting(void) } fs_initcall(clocksource_done_booting); -#else /* CONFIG_GENERIC_TIME */ - -static inline void clocksource_select(void) { } - -#endif - /* * Enqueue the clocksource sorted by rating */ -- cgit v1.2.2 From 4a5d6ba1914d1bf1fcfb5e15834c29d84a879219 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 14 Sep 2009 12:45:39 +0100 Subject: CRED: Allow put_cred() to cope with a NULL groups list put_cred() will oops if given a NULL groups list, but that is now possible with the existence of cred_alloc_blank(), as used in keyctl_session_to_parent(). Added in commit: commit ee18d64c1f632043a02e6f5ba5e045bb26a5465f Author: David Howells Date: Wed Sep 2 09:14:21 2009 +0100 KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] Reported-by: Marc Dionne Signed-off-by: David Howells Signed-off-by: James Morris --- kernel/cred.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cred.c b/kernel/cred.c index 006fcab009d5..d7f7a01082eb 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -147,7 +147,8 @@ static void put_cred_rcu(struct rcu_head *rcu) key_put(cred->thread_keyring); key_put(cred->request_key_auth); release_tgcred(cred); - put_group_info(cred->group_info); + if (cred->group_info) + put_group_info(cred->group_info); free_uid(cred->user); kmem_cache_free(cred_jar, cred); } -- cgit v1.2.2 From 353f6dd2dec992ddd34620a94b051b0f76227379 Mon Sep 17 00:00:00 2001 From: Anirban Sinha Date: Mon, 14 Sep 2009 11:13:37 -0700 Subject: cleanup console_print() console_print() is an old legacy interface mostly unused in the entire kernel tree. It's best to clean up its existing use and let developers use their own implementation of it as they feel fit. Signed-off-by: Anirban Sinha Signed-off-by: Linus Torvalds --- kernel/printk.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'kernel') diff --git a/kernel/printk.c b/kernel/printk.c index e10d193a833a..602033acd6c7 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1075,12 +1075,6 @@ void __sched console_conditional_schedule(void) } EXPORT_SYMBOL(console_conditional_schedule); -void console_print(const char *s) -{ - printk(KERN_EMERG "%s", s); -} -EXPORT_SYMBOL(console_print); - void console_unblank(void) { struct console *c; -- cgit v1.2.2 From 555f386c98cc93890f48fdea098936755270304b Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Mon, 14 Sep 2009 20:10:15 -0400 Subject: ftrace: document function and function graph implementation While implementing function tracer and function tracer graph support, I found the exact arch implementation details to be a bit lacking (and my x86 foo ain't great). So after pounding out support for the Blackfin arch, start documenting the requirements/details. Signed-off-by: Mike Frysinger LKML-Reference: <1252973415-21264-1-git-send-email-vapier@gentoo.org> Acked-by: Frederic Weisbecker Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index aa002cef924c..e71634604400 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -11,12 +11,18 @@ config NOP_TRACER config HAVE_FTRACE_NMI_ENTER bool + help + See Documentation/trace/ftrace-implementation.txt config HAVE_FUNCTION_TRACER bool + help + See Documentation/trace/ftrace-implementation.txt config HAVE_FUNCTION_GRAPH_TRACER bool + help + See Documentation/trace/ftrace-implementation.txt config HAVE_FUNCTION_GRAPH_FP_TEST bool @@ -28,21 +34,25 @@ config HAVE_FUNCTION_GRAPH_FP_TEST config HAVE_FUNCTION_TRACE_MCOUNT_TEST bool help - This gets selected when the arch tests the function_trace_stop - variable at the mcount call site. Otherwise, this variable - is tested by the called function. + See Documentation/trace/ftrace-implementation.txt config HAVE_DYNAMIC_FTRACE bool + help + See Documentation/trace/ftrace-implementation.txt config HAVE_FTRACE_MCOUNT_RECORD bool + help + See Documentation/trace/ftrace-implementation.txt config HAVE_HW_BRANCH_TRACER bool config HAVE_SYSCALL_TRACEPOINTS bool + help + See Documentation/trace/ftrace-implementation.txt config TRACER_MAX_TRACE bool -- cgit v1.2.2 From b3e62e35058fc744ac794611f4e79bcd1c5a4b83 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Tue, 15 Sep 2009 14:44:36 +0800 Subject: perf_counter: Fix buffer overflow in perf_copy_attr() If we pass a big size data over perf_counter_open() syscall, the kernel will copy this data to a small buffer, it will cause kernel crash. This bug makes the kernel unsafe and non-root local user can trigger it. Signed-off-by: Xiao Guangrong Acked-by: Peter Zijlstra Acked-by: Paul Mackerras Cc: LKML-Reference: <4AAF37D4.5010706@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index d7cbc579fc80..a67a1dc3cfa3 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -4171,6 +4171,7 @@ static int perf_copy_attr(struct perf_counter_attr __user *uattr, if (val) goto err_size; } + size = sizeof(*attr); } ret = copy_from_user(attr, uattr, size); -- cgit v1.2.2 From 12e09337fe238981cb0c87543306e23775d1a143 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 14 Sep 2009 23:37:40 +0200 Subject: time: Prevent 32 bit overflow with set_normalized_timespec() set_normalized_timespec() nsec argument is of type long. The recent timekeeping changes of ktime_get_ts() feed ts->tv_nsec + tomono.tv_nsec + nsecs to set_normalized_timespec(). On 32 bit machines that sum can be larger than (1 << 31) and therefor result in a negative value which screws up the result completely. Make the nsec argument of set_normalized_timespec() s64 to fix the problem at hand. This also prevents similar problems for future users of set_normalized_timespec(). Signed-off-by: Thomas Gleixner Tested-by: Carsten Emde LKML-Reference: Cc: Martin Schwidefsky Cc: John Stultz --- kernel/time.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time.c b/kernel/time.c index 29511943871a..2e2e469a7fec 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -370,13 +370,20 @@ EXPORT_SYMBOL(mktime); * 0 <= tv_nsec < NSEC_PER_SEC * For negative values only the tv_sec field is negative ! */ -void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec) +void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) { while (nsec >= NSEC_PER_SEC) { + /* + * The following asm() prevents the compiler from + * optimising this loop into a modulo operation. See + * also __iter_div_u64_rem() in include/linux/time.h + */ + asm("" : "+rm"(nsec)); nsec -= NSEC_PER_SEC; ++sec; } while (nsec < 0) { + asm("" : "+rm"(nsec)); nsec += NSEC_PER_SEC; --sec; } -- cgit v1.2.2 From b78bb868c54bebbf8d8786a3f8320700d6d2b864 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 15 Sep 2009 14:23:18 +0200 Subject: sched: Fix double_rq_lock() compile warning Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index e27a53685ed9..17e4391ec2de 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -119,8 +119,6 @@ */ #define RUNTIME_INF ((u64)~0ULL) -static void double_rq_lock(struct rq *rq1, struct rq *rq2); - static inline int rt_policy(int policy) { if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) @@ -1695,6 +1693,8 @@ static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) #ifdef CONFIG_PREEMPT +static void double_rq_lock(struct rq *rq1, struct rq *rq2); + /* * fair double_lock_balance: Safely acquires both rq->locks in a fair * way at the expense of forcing extra atomic operations in all -- cgit v1.2.2 From e6b1b2c9c0461c4e0971ed905ce3cda6512ee82a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 11 Sep 2009 11:59:22 +0200 Subject: sched: Split WAKEUP_OVERLAP It consists of two conditions, split them out in separate toggles so we can test them independently. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 7 ++++--- kernel/sched_features.h | 1 + 2 files changed, 5 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index aa7f84121016..cea5b82242ee 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1526,9 +1526,10 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) if (!sched_feat(WAKEUP_PREEMPT)) return; - if (sched_feat(WAKEUP_OVERLAP) && (sync || - (se->avg_overlap < sysctl_sched_migration_cost && - pse->avg_overlap < sysctl_sched_migration_cost))) { + if ((sched_feat(WAKEUP_SYNC) && sync) || + (sched_feat(WAKEUP_OVERLAP) && + (se->avg_overlap < sysctl_sched_migration_cost && + pse->avg_overlap < sysctl_sched_migration_cost))) { resched_task(curr); return; } diff --git a/kernel/sched_features.h b/kernel/sched_features.h index e2dc63a5815d..07c8250b404c 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -12,6 +12,7 @@ SCHED_FEAT(ASYM_GRAN, 1) SCHED_FEAT(LB_BIAS, 1) SCHED_FEAT(LB_WAKEUP_UPDATE, 1) SCHED_FEAT(ASYM_EFF_LOAD, 1) +SCHED_FEAT(WAKEUP_SYNC, 0) SCHED_FEAT(WAKEUP_OVERLAP, 0) SCHED_FEAT(LAST_BUDDY, 1) SCHED_FEAT(OWNER_SPIN, 1) -- cgit v1.2.2 From 3cb63d527f76e25dbccce4f577f21aecfa2abac7 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Fri, 11 Sep 2009 12:01:17 +0200 Subject: sched: Complete buddy switches Add a NEXT_BUDDY feature flag to aid in debugging. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 3 ++- kernel/sched_features.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index cea5b82242ee..4f6356e70ad6 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1501,7 +1501,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) */ if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle)) set_last_buddy(se); - set_next_buddy(pse); + if (sched_feat(NEXT_BUDDY)) + set_next_buddy(pse); /* * We can come here with TIF_NEED_RESCHED already set from new task diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 07c8250b404c..6174c1233993 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -14,5 +14,6 @@ SCHED_FEAT(LB_WAKEUP_UPDATE, 1) SCHED_FEAT(ASYM_EFF_LOAD, 1) SCHED_FEAT(WAKEUP_SYNC, 0) SCHED_FEAT(WAKEUP_OVERLAP, 0) +SCHED_FEAT(NEXT_BUDDY, 1) SCHED_FEAT(LAST_BUDDY, 1) SCHED_FEAT(OWNER_SPIN, 1) -- cgit v1.2.2 From e26af0e8b2c9916f1e8a12ddaf52057bbe8ff600 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 11 Sep 2009 12:31:23 +0200 Subject: sched: Add come comments to the sched features Add text... Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_features.h | 93 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 85 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 6174c1233993..891ea0f72b46 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -1,19 +1,96 @@ +/* + * Disregards a certain amount of sleep time (sched_latency_ns) and + * considers the task to be running during that period. This gives it + * a service deficit on wakeup, allowing it to run sooner. + */ SCHED_FEAT(NEW_FAIR_SLEEPERS, 0) + +/* + * By not normalizing the sleep time, heavy tasks get an effective + * longer period, and lighter task an effective shorter period they + * are considered running. + */ SCHED_FEAT(NORMALIZED_SLEEPER, 0) -SCHED_FEAT(ADAPTIVE_GRAN, 1) -SCHED_FEAT(WAKEUP_PREEMPT, 1) + +/* + * Place new tasks ahead so that they do not starve already running + * tasks + */ SCHED_FEAT(START_DEBIT, 1) + +/* + * Should wakeups try to preempt running tasks. + */ +SCHED_FEAT(WAKEUP_PREEMPT, 1) + +/* + * Compute wakeup_gran based on task behaviour, clipped to + * [0, sched_wakeup_gran_ns] + */ +SCHED_FEAT(ADAPTIVE_GRAN, 1) + +/* + * When converting the wakeup granularity to virtual time, do it such + * that heavier tasks preempting a lighter task have an edge. + */ +SCHED_FEAT(ASYM_GRAN, 1) + +/* + * Always wakeup-preempt SYNC wakeups, see SYNC_WAKEUPS. + */ +SCHED_FEAT(WAKEUP_SYNC, 0) + +/* + * Wakeup preempt based on task behaviour. Tasks that do not overlap + * don't get preempted. + */ +SCHED_FEAT(WAKEUP_OVERLAP, 0) + +/* + * Use the SYNC wakeup hint, pipes and the likes use this to indicate + * the remote end is likely to consume the data we just wrote, and + * therefore has cache benefit from being placed on the same cpu, see + * also AFFINE_WAKEUPS. + */ +SCHED_FEAT(SYNC_WAKEUPS, 1) + +/* + * Based on load and program behaviour, see if it makes sense to place + * a newly woken task on the same cpu as the task that woke it -- + * improve cache locality. Typically used with SYNC wakeups as + * generated by pipes and the like, see also SYNC_WAKEUPS. + */ SCHED_FEAT(AFFINE_WAKEUPS, 1) + +/* + * Prefer to schedule the task we woke last (assuming it failed + * wakeup-preemption), since its likely going to consume data we + * touched, increases cache locality. + */ +SCHED_FEAT(NEXT_BUDDY, 1) + +/* + * Prefer to schedule the task that ran last (when we did + * wake-preempt) as that likely will touch the same data, increases + * cache locality. + */ +SCHED_FEAT(LAST_BUDDY, 1) + +/* + * Consider buddies to be cache hot, decreases the likelyness of a + * cache buddy being migrated away, increases cache locality. + */ SCHED_FEAT(CACHE_HOT_BUDDY, 1) -SCHED_FEAT(SYNC_WAKEUPS, 1) + SCHED_FEAT(HRTICK, 0) SCHED_FEAT(DOUBLE_TICK, 0) -SCHED_FEAT(ASYM_GRAN, 1) SCHED_FEAT(LB_BIAS, 1) SCHED_FEAT(LB_WAKEUP_UPDATE, 1) SCHED_FEAT(ASYM_EFF_LOAD, 1) -SCHED_FEAT(WAKEUP_SYNC, 0) -SCHED_FEAT(WAKEUP_OVERLAP, 0) -SCHED_FEAT(NEXT_BUDDY, 1) -SCHED_FEAT(LAST_BUDDY, 1) + +/* + * Spin-wait on mutex acquisition when the mutex owner is running on + * another cpu -- assumes that when the owner is running, it will soon + * release the lock. Decreases scheduling overhead. + */ SCHED_FEAT(OWNER_SPIN, 1) -- cgit v1.2.2 From f5f08f39ee4c5fd0a757d25d9e04d696676b3df7 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2009 13:35:28 +0200 Subject: sched: Move code around In preparation to other code movement, move weighted_cpuload(), source_load() and target_load() before the class includes. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 81 ++++++++++++++++++++++++++++------------------------------ 1 file changed, 39 insertions(+), 42 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 17e4391ec2de..b56d1505d058 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1507,8 +1507,45 @@ static int tg_nop(struct task_group *tg, void *data) #endif #ifdef CONFIG_SMP -static unsigned long source_load(int cpu, int type); -static unsigned long target_load(int cpu, int type); +/* Used instead of source_load when we know the type == 0 */ +static unsigned long weighted_cpuload(const int cpu) +{ + return cpu_rq(cpu)->load.weight; +} + +/* + * Return a low guess at the load of a migration-source cpu weighted + * according to the scheduling class and "nice" value. + * + * We want to under-estimate the load of migration sources, to + * balance conservatively. + */ +static unsigned long source_load(int cpu, int type) +{ + struct rq *rq = cpu_rq(cpu); + unsigned long total = weighted_cpuload(cpu); + + if (type == 0 || !sched_feat(LB_BIAS)) + return total; + + return min(rq->cpu_load[type-1], total); +} + +/* + * Return a high guess at the load of a migration-target cpu weighted + * according to the scheduling class and "nice" value. + */ +static unsigned long target_load(int cpu, int type) +{ + struct rq *rq = cpu_rq(cpu); + unsigned long total = weighted_cpuload(cpu); + + if (type == 0 || !sched_feat(LB_BIAS)) + return total; + + return max(rq->cpu_load[type-1], total); +} + static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); static unsigned long cpu_avg_load_per_task(int cpu) @@ -1959,13 +1996,6 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p, } #ifdef CONFIG_SMP - -/* Used instead of source_load when we know the type == 0 */ -static unsigned long weighted_cpuload(const int cpu) -{ - return cpu_rq(cpu)->load.weight; -} - /* * Is this task likely cache-hot: */ @@ -2240,39 +2270,6 @@ void kick_process(struct task_struct *p) } EXPORT_SYMBOL_GPL(kick_process); -/* - * Return a low guess at the load of a migration-source cpu weighted - * according to the scheduling class and "nice" value. - * - * We want to under-estimate the load of migration sources, to - * balance conservatively. - */ -static unsigned long source_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return min(rq->cpu_load[type-1], total); -} - -/* - * Return a high guess at the load of a migration-target cpu weighted - * according to the scheduling class and "nice" value. - */ -static unsigned long target_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return max(rq->cpu_load[type-1], total); -} - /* * find_idlest_group finds and returns the least busy CPU group within the * domain. -- cgit v1.2.2 From aaee1203ca52b9db799433c33c9bffc33cdf8909 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2009 13:36:25 +0200 Subject: sched: Move sched_balance_self() into sched_fair.c Move the sched_balance_self() code into sched_fair.c This facilitates the merger of sched_balance_self() and sched_fair::select_task_rq(). Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 146 ---------------------------------------------------- kernel/sched_fair.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 145 insertions(+), 146 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index b56d1505d058..60400a22401f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2269,152 +2269,6 @@ void kick_process(struct task_struct *p) preempt_enable(); } EXPORT_SYMBOL_GPL(kick_process); - -/* - * find_idlest_group finds and returns the least busy CPU group within the - * domain. - */ -static struct sched_group * -find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) -{ - struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; - unsigned long min_load = ULONG_MAX, this_load = 0; - int load_idx = sd->forkexec_idx; - int imbalance = 100 + (sd->imbalance_pct-100)/2; - - do { - unsigned long load, avg_load; - int local_group; - int i; - - /* Skip over this group if it has no CPUs allowed */ - if (!cpumask_intersects(sched_group_cpus(group), - &p->cpus_allowed)) - continue; - - local_group = cpumask_test_cpu(this_cpu, - sched_group_cpus(group)); - - /* Tally up the load of all CPUs in the group */ - avg_load = 0; - - for_each_cpu(i, sched_group_cpus(group)) { - /* Bias balancing toward cpus of our domain */ - if (local_group) - load = source_load(i, load_idx); - else - load = target_load(i, load_idx); - - avg_load += load; - } - - /* Adjust by relative CPU power of the group */ - avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power; - - if (local_group) { - this_load = avg_load; - this = group; - } else if (avg_load < min_load) { - min_load = avg_load; - idlest = group; - } - } while (group = group->next, group != sd->groups); - - if (!idlest || 100*this_load < imbalance*min_load) - return NULL; - return idlest; -} - -/* - * find_idlest_cpu - find the idlest cpu among the cpus in group. - */ -static int -find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) -{ - unsigned long load, min_load = ULONG_MAX; - int idlest = -1; - int i; - - /* Traverse only the allowed CPUs */ - for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { - load = weighted_cpuload(i); - - if (load < min_load || (load == min_load && i == this_cpu)) { - min_load = load; - idlest = i; - } - } - - return idlest; -} - -/* - * sched_balance_self: balance the current task (running on cpu) in domains - * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and - * SD_BALANCE_EXEC. - * - * Balance, ie. select the least loaded group. - * - * Returns the target CPU number, or the same CPU if no balancing is needed. - * - * preempt must be disabled. - */ -static int sched_balance_self(int cpu, int flag) -{ - struct task_struct *t = current; - struct sched_domain *tmp, *sd = NULL; - - for_each_domain(cpu, tmp) { - /* - * If power savings logic is enabled for a domain, stop there. - */ - if (tmp->flags & SD_POWERSAVINGS_BALANCE) - break; - if (tmp->flags & flag) - sd = tmp; - } - - if (sd) - update_shares(sd); - - while (sd) { - struct sched_group *group; - int new_cpu, weight; - - if (!(sd->flags & flag)) { - sd = sd->child; - continue; - } - - group = find_idlest_group(sd, t, cpu); - if (!group) { - sd = sd->child; - continue; - } - - new_cpu = find_idlest_cpu(group, t, cpu); - if (new_cpu == -1 || new_cpu == cpu) { - /* Now try balancing at a lower domain level of cpu */ - sd = sd->child; - continue; - } - - /* Now try balancing at a lower domain level of new_cpu */ - cpu = new_cpu; - weight = cpumask_weight(sched_domain_span(sd)); - sd = NULL; - for_each_domain(cpu, tmp) { - if (weight <= cpumask_weight(sched_domain_span(tmp))) - break; - if (tmp->flags & flag) - sd = tmp; - } - /* while loop will break here if sd == NULL */ - } - - return cpu; -} - #endif /* CONFIG_SMP */ /** diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 4f6356e70ad6..a82d71d3afed 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1360,6 +1360,151 @@ static int select_task_rq_fair(struct task_struct *p, int sync) out: return wake_idle(new_cpu, p); } + +/* + * find_idlest_group finds and returns the least busy CPU group within the + * domain. + */ +static struct sched_group * +find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) +{ + struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; + unsigned long min_load = ULONG_MAX, this_load = 0; + int load_idx = sd->forkexec_idx; + int imbalance = 100 + (sd->imbalance_pct-100)/2; + + do { + unsigned long load, avg_load; + int local_group; + int i; + + /* Skip over this group if it has no CPUs allowed */ + if (!cpumask_intersects(sched_group_cpus(group), + &p->cpus_allowed)) + continue; + + local_group = cpumask_test_cpu(this_cpu, + sched_group_cpus(group)); + + /* Tally up the load of all CPUs in the group */ + avg_load = 0; + + for_each_cpu(i, sched_group_cpus(group)) { + /* Bias balancing toward cpus of our domain */ + if (local_group) + load = source_load(i, load_idx); + else + load = target_load(i, load_idx); + + avg_load += load; + } + + /* Adjust by relative CPU power of the group */ + avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power; + + if (local_group) { + this_load = avg_load; + this = group; + } else if (avg_load < min_load) { + min_load = avg_load; + idlest = group; + } + } while (group = group->next, group != sd->groups); + + if (!idlest || 100*this_load < imbalance*min_load) + return NULL; + return idlest; +} + +/* + * find_idlest_cpu - find the idlest cpu among the cpus in group. + */ +static int +find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) +{ + unsigned long load, min_load = ULONG_MAX; + int idlest = -1; + int i; + + /* Traverse only the allowed CPUs */ + for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { + load = weighted_cpuload(i); + + if (load < min_load || (load == min_load && i == this_cpu)) { + min_load = load; + idlest = i; + } + } + + return idlest; +} + +/* + * sched_balance_self: balance the current task (running on cpu) in domains + * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and + * SD_BALANCE_EXEC. + * + * Balance, ie. select the least loaded group. + * + * Returns the target CPU number, or the same CPU if no balancing is needed. + * + * preempt must be disabled. + */ +static int sched_balance_self(int cpu, int flag) +{ + struct task_struct *t = current; + struct sched_domain *tmp, *sd = NULL; + + for_each_domain(cpu, tmp) { + /* + * If power savings logic is enabled for a domain, stop there. + */ + if (tmp->flags & SD_POWERSAVINGS_BALANCE) + break; + if (tmp->flags & flag) + sd = tmp; + } + + if (sd) + update_shares(sd); + + while (sd) { + struct sched_group *group; + int new_cpu, weight; + + if (!(sd->flags & flag)) { + sd = sd->child; + continue; + } + + group = find_idlest_group(sd, t, cpu); + if (!group) { + sd = sd->child; + continue; + } + + new_cpu = find_idlest_cpu(group, t, cpu); + if (new_cpu == -1 || new_cpu == cpu) { + /* Now try balancing at a lower domain level of cpu */ + sd = sd->child; + continue; + } + + /* Now try balancing at a lower domain level of new_cpu */ + cpu = new_cpu; + weight = cpumask_weight(sched_domain_span(sd)); + sd = NULL; + for_each_domain(cpu, tmp) { + if (weight <= cpumask_weight(sched_domain_span(tmp))) + break; + if (tmp->flags & flag) + sd = tmp; + } + /* while loop will break here if sd == NULL */ + } + + return cpu; +} #endif /* CONFIG_SMP */ /* -- cgit v1.2.2 From 5f3edc1b1ead6d9bd45a85c551f44eff8fe76b9f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2009 13:42:00 +0200 Subject: sched: Hook sched_balance_self() into sched_class::select_task_rq() Rather ugly patch to fully place the sched_balance_self() code inside the fair class. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 14 +++++++------- kernel/sched_fair.c | 7 ++++++- kernel/sched_idletask.c | 2 +- kernel/sched_rt.c | 5 ++++- 4 files changed, 18 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 60400a22401f..32b7a81230c2 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2350,7 +2350,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) if (unlikely(task_running(rq, p))) goto out_activate; - cpu = p->sched_class->select_task_rq(p, sync); + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, sync); if (cpu != orig_cpu) { set_task_cpu(p, cpu); task_rq_unlock(rq, &flags); @@ -2525,11 +2525,6 @@ void sched_fork(struct task_struct *p, int clone_flags) __sched_fork(p); -#ifdef CONFIG_SMP - cpu = sched_balance_self(cpu, SD_BALANCE_FORK); -#endif - set_task_cpu(p, cpu); - /* * Make sure we do not leak PI boosting priority to the child. */ @@ -2560,6 +2555,11 @@ void sched_fork(struct task_struct *p, int clone_flags) if (!rt_prio(p->prio)) p->sched_class = &fair_sched_class; +#ifdef CONFIG_SMP + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0); +#endif + set_task_cpu(p, cpu); + #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) if (likely(sched_info_on())) memset(&p->sched_info, 0, sizeof(p->sched_info)); @@ -3114,7 +3114,7 @@ out: void sched_exec(void) { int new_cpu, this_cpu = get_cpu(); - new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); + new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0); put_cpu(); if (new_cpu != this_cpu) sched_migrate_task(current, new_cpu); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a82d71d3afed..f2eb5b934715 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1300,7 +1300,9 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, return 0; } -static int select_task_rq_fair(struct task_struct *p, int sync) +static int sched_balance_self(int cpu, int flag); + +static int select_task_rq_fair(struct task_struct *p, int flag, int sync) { struct sched_domain *sd, *this_sd = NULL; int prev_cpu, this_cpu, new_cpu; @@ -1314,6 +1316,9 @@ static int select_task_rq_fair(struct task_struct *p, int sync) this_rq = cpu_rq(this_cpu); new_cpu = prev_cpu; + if (flag != SD_BALANCE_WAKE) + return sched_balance_self(this_cpu, flag); + /* * 'this_sd' is the first domain that both * this_cpu and prev_cpu are present in: diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 499672c10cbd..99b2f0337609 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -6,7 +6,7 @@ */ #ifdef CONFIG_SMP -static int select_task_rq_idle(struct task_struct *p, int sync) +static int select_task_rq_idle(struct task_struct *p, int flag, int sync) { return task_cpu(p); /* IDLE tasks as never migrated */ } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 2eb4bd6a526c..438380810ac4 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -938,10 +938,13 @@ static void yield_task_rt(struct rq *rq) #ifdef CONFIG_SMP static int find_lowest_rq(struct task_struct *task); -static int select_task_rq_rt(struct task_struct *p, int sync) +static int select_task_rq_rt(struct task_struct *p, int flag, int sync) { struct rq *rq = task_rq(p); + if (flag != SD_BALANCE_WAKE) + return smp_processor_id(); + /* * If the current task is an RT task, then * try to see if we can wake this RT task up on another -- cgit v1.2.2 From e9c8431185d6c406887190519f6dbdd112641686 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 15 Sep 2009 14:43:03 +0200 Subject: sched: Add TASK_WAKING We're going to want to drop rq->lock in try_to_wake_up() for a longer period of time, however we also want to deal with concurrent waking of the same task, which is currently handled by holding rq->lock. So introduce a new TASK state, namely TASK_WAKING, which indicates someone is already waking the task (other wakers will fail p->state & state). We also keep preemption disabled over the whole ttwu(). Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 32b7a81230c2..fc6fda881d2e 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2310,7 +2310,6 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) { int cpu, orig_cpu, this_cpu, success = 0; unsigned long flags; - long old_state; struct rq *rq; if (!sched_feat(SYNC_WAKEUPS)) @@ -2332,11 +2331,12 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) } #endif + this_cpu = get_cpu(); + smp_wmb(); rq = task_rq_lock(p, &flags); update_rq_clock(rq); - old_state = p->state; - if (!(old_state & state)) + if (!(p->state & state)) goto out; if (p->se.on_rq) @@ -2344,27 +2344,25 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) cpu = task_cpu(p); orig_cpu = cpu; - this_cpu = smp_processor_id(); #ifdef CONFIG_SMP if (unlikely(task_running(rq, p))) goto out_activate; + /* + * In order to handle concurrent wakeups and release the rq->lock + * we put the task in TASK_WAKING state. + */ + p->state = TASK_WAKING; + task_rq_unlock(rq, &flags); + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, sync); - if (cpu != orig_cpu) { + if (cpu != orig_cpu) set_task_cpu(p, cpu); - task_rq_unlock(rq, &flags); - /* might preempt at this point */ - rq = task_rq_lock(p, &flags); - old_state = p->state; - if (!(old_state & state)) - goto out; - if (p->se.on_rq) - goto out_running; - this_cpu = smp_processor_id(); - cpu = task_cpu(p); - } + rq = task_rq_lock(p, &flags); + WARN_ON(p->state != TASK_WAKING); + cpu = task_cpu(p); #ifdef CONFIG_SCHEDSTATS schedstat_inc(rq, ttwu_count); @@ -2422,6 +2420,7 @@ out_running: #endif out: task_rq_unlock(rq, &flags); + put_cpu(); return success; } -- cgit v1.2.2 From c88d5910890ad35af283344417891344604f0438 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2009 13:50:02 +0200 Subject: sched: Merge select_task_rq_fair() and sched_balance_self() The problem with wake_idle() is that is doesn't respect things like cpu_power, which means it doesn't deal well with SMT nor the recent RT interaction. To cure this, it needs to do what sched_balance_self() does, which leads to the possibility of merging select_task_rq_fair() and sched_balance_self(). Modify sched_balance_self() to: - update_shares() when walking up the domain tree, (it only called it for the top domain, but it should have done this anyway), which allows us to remove this ugly bit from try_to_wake_up(). - do wake_affine() on the smallest domain that contains both this (the waking) and the prev (the wakee) cpu for WAKE invocations. Then use the top-down balance steps it had to replace wake_idle(). This leads to the dissapearance of SD_WAKE_BALANCE and SD_WAKE_IDLE_FAR, with SD_WAKE_IDLE replaced with SD_BALANCE_WAKE. SD_WAKE_AFFINE needs SD_BALANCE_WAKE to be effective. Touch all topology bits to replace the old with new SD flags -- platforms might need re-tuning, enabling SD_BALANCE_WAKE conditionally on a NUMA distance seems like a good additional feature, magny-core and small nehalem systems would want this enabled, systems with slow interconnects would not. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 41 +-------- kernel/sched_fair.c | 233 ++++++++++++++-------------------------------------- 2 files changed, 66 insertions(+), 208 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index fc6fda881d2e..6c819f338b11 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -512,14 +512,6 @@ struct root_domain { #ifdef CONFIG_SMP struct cpupri cpupri; #endif -#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) - /* - * Preferred wake up cpu nominated by sched_mc balance that will be - * used when most cpus are idle in the system indicating overall very - * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2) - */ - unsigned int sched_mc_preferred_wakeup_cpu; -#endif }; /* @@ -2315,22 +2307,6 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) if (!sched_feat(SYNC_WAKEUPS)) sync = 0; -#ifdef CONFIG_SMP - if (sched_feat(LB_WAKEUP_UPDATE) && !root_task_group_empty()) { - struct sched_domain *sd; - - this_cpu = raw_smp_processor_id(); - cpu = task_cpu(p); - - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { - update_shares(sd); - break; - } - } - } -#endif - this_cpu = get_cpu(); smp_wmb(); @@ -3533,11 +3509,6 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, *imbalance = sds->min_load_per_task; sds->busiest = sds->group_min; - if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) { - cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu = - group_first_cpu(sds->group_leader); - } - return 1; } @@ -7850,9 +7821,7 @@ static int sd_degenerate(struct sched_domain *sd) } /* Following flags don't use groups */ - if (sd->flags & (SD_WAKE_IDLE | - SD_WAKE_AFFINE | - SD_WAKE_BALANCE)) + if (sd->flags & (SD_WAKE_AFFINE)) return 0; return 1; @@ -7869,10 +7838,6 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) return 0; - /* Does parent contain flags not in child? */ - /* WAKE_BALANCE is a subset of WAKE_AFFINE */ - if (cflags & SD_WAKE_AFFINE) - pflags &= ~SD_WAKE_BALANCE; /* Flags needing groups don't count if only 1 group in parent */ if (parent->groups == parent->groups->next) { pflags &= ~(SD_LOAD_BALANCE | @@ -8558,10 +8523,10 @@ static void set_domain_attribute(struct sched_domain *sd, request = attr->relax_domain_level; if (request < sd->level) { /* turn off idle balance on this domain */ - sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); + sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); } else { /* turn on idle balance on this domain */ - sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); + sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); } } diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index f2eb5b934715..09d19f77eb3a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1062,83 +1062,6 @@ static void yield_task_fair(struct rq *rq) se->vruntime = rightmost->vruntime + 1; } -/* - * wake_idle() will wake a task on an idle cpu if task->cpu is - * not idle and an idle cpu is available. The span of cpus to - * search starts with cpus closest then further out as needed, - * so we always favor a closer, idle cpu. - * Domains may include CPUs that are not usable for migration, - * hence we need to mask them out (rq->rd->online) - * - * Returns the CPU we should wake onto. - */ -#if defined(ARCH_HAS_SCHED_WAKE_IDLE) - -#define cpu_rd_active(cpu, rq) cpumask_test_cpu(cpu, rq->rd->online) - -static int wake_idle(int cpu, struct task_struct *p) -{ - struct sched_domain *sd; - int i; - unsigned int chosen_wakeup_cpu; - int this_cpu; - struct rq *task_rq = task_rq(p); - - /* - * At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu - * are idle and this is not a kernel thread and this task's affinity - * allows it to be moved to preferred cpu, then just move! - */ - - this_cpu = smp_processor_id(); - chosen_wakeup_cpu = - cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu; - - if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP && - idle_cpu(cpu) && idle_cpu(this_cpu) && - p->mm && !(p->flags & PF_KTHREAD) && - cpu_isset(chosen_wakeup_cpu, p->cpus_allowed)) - return chosen_wakeup_cpu; - - /* - * If it is idle, then it is the best cpu to run this task. - * - * This cpu is also the best, if it has more than one task already. - * Siblings must be also busy(in most cases) as they didn't already - * pickup the extra load from this cpu and hence we need not check - * sibling runqueue info. This will avoid the checks and cache miss - * penalities associated with that. - */ - if (idle_cpu(cpu) || cpu_rq(cpu)->cfs.nr_running > 1) - return cpu; - - for_each_domain(cpu, sd) { - if ((sd->flags & SD_WAKE_IDLE) - || ((sd->flags & SD_WAKE_IDLE_FAR) - && !task_hot(p, task_rq->clock, sd))) { - for_each_cpu_and(i, sched_domain_span(sd), - &p->cpus_allowed) { - if (cpu_rd_active(i, task_rq) && idle_cpu(i)) { - if (i != task_cpu(p)) { - schedstat_inc(p, - se.nr_wakeups_idle); - } - return i; - } - } - } else { - break; - } - } - return cpu; -} -#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/ -static inline int wake_idle(int cpu, struct task_struct *p) -{ - return cpu; -} -#endif - #ifdef CONFIG_SMP #ifdef CONFIG_FAIR_GROUP_SCHED @@ -1225,21 +1148,22 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu, #endif -static int -wake_affine(struct sched_domain *this_sd, struct rq *this_rq, - struct task_struct *p, int prev_cpu, int this_cpu, int sync, - int idx, unsigned long load, unsigned long this_load, - unsigned int imbalance) +static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) { - struct task_struct *curr = this_rq->curr; - struct task_group *tg; - unsigned long tl = this_load; + struct task_struct *curr = current; + unsigned long this_load, load; + int idx, this_cpu, prev_cpu; unsigned long tl_per_task; + unsigned int imbalance; + struct task_group *tg; unsigned long weight; int balanced; - if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS)) - return 0; + idx = sd->wake_idx; + this_cpu = smp_processor_id(); + prev_cpu = task_cpu(p); + load = source_load(prev_cpu, idx); + this_load = target_load(this_cpu, idx); if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost || p->se.avg_overlap > sysctl_sched_migration_cost)) @@ -1254,24 +1178,26 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, tg = task_group(current); weight = current->se.load.weight; - tl += effective_load(tg, this_cpu, -weight, -weight); + this_load += effective_load(tg, this_cpu, -weight, -weight); load += effective_load(tg, prev_cpu, 0, -weight); } tg = task_group(p); weight = p->se.load.weight; + imbalance = 100 + (sd->imbalance_pct - 100) / 2; + /* * In low-load situations, where prev_cpu is idle and this_cpu is idle - * due to the sync cause above having dropped tl to 0, we'll always have - * an imbalance, but there's really nothing you can do about that, so - * that's good too. + * due to the sync cause above having dropped this_load to 0, we'll + * always have an imbalance, but there's really nothing you can do + * about that, so that's good too. * * Otherwise check if either cpus are near enough in load to allow this * task to be woken on this_cpu. */ - balanced = !tl || - 100*(tl + effective_load(tg, this_cpu, weight, weight)) <= + balanced = !this_load || + 100*(this_load + effective_load(tg, this_cpu, weight, weight)) <= imbalance*(load + effective_load(tg, prev_cpu, 0, weight)); /* @@ -1285,14 +1211,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, schedstat_inc(p, se.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); - if (balanced || (tl <= load && tl + target_load(prev_cpu, idx) <= - tl_per_task)) { + if (balanced || + (this_load <= load && + this_load + target_load(prev_cpu, idx) <= tl_per_task)) { /* * This domain has SD_WAKE_AFFINE and * p is cache cold in this domain, and * there is no bad imbalance. */ - schedstat_inc(this_sd, ttwu_move_affine); + schedstat_inc(sd, ttwu_move_affine); schedstat_inc(p, se.nr_wakeups_affine); return 1; @@ -1300,72 +1227,6 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, return 0; } -static int sched_balance_self(int cpu, int flag); - -static int select_task_rq_fair(struct task_struct *p, int flag, int sync) -{ - struct sched_domain *sd, *this_sd = NULL; - int prev_cpu, this_cpu, new_cpu; - unsigned long load, this_load; - struct rq *this_rq; - unsigned int imbalance; - int idx; - - prev_cpu = task_cpu(p); - this_cpu = smp_processor_id(); - this_rq = cpu_rq(this_cpu); - new_cpu = prev_cpu; - - if (flag != SD_BALANCE_WAKE) - return sched_balance_self(this_cpu, flag); - - /* - * 'this_sd' is the first domain that both - * this_cpu and prev_cpu are present in: - */ - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) { - this_sd = sd; - break; - } - } - - if (unlikely(!cpumask_test_cpu(this_cpu, &p->cpus_allowed))) - goto out; - - /* - * Check for affine wakeup and passive balancing possibilities. - */ - if (!this_sd) - goto out; - - idx = this_sd->wake_idx; - - imbalance = 100 + (this_sd->imbalance_pct - 100) / 2; - - load = source_load(prev_cpu, idx); - this_load = target_load(this_cpu, idx); - - if (wake_affine(this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx, - load, this_load, imbalance)) - return this_cpu; - - /* - * Start passive balancing when half the imbalance_pct - * limit is reached. - */ - if (this_sd->flags & SD_WAKE_BALANCE) { - if (imbalance*this_load <= 100*load) { - schedstat_inc(this_sd, ttwu_move_balance); - schedstat_inc(p, se.nr_wakeups_passive); - return this_cpu; - } - } - -out: - return wake_idle(new_cpu, p); -} - /* * find_idlest_group finds and returns the least busy CPU group within the * domain. @@ -1455,10 +1316,20 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) * * preempt must be disabled. */ -static int sched_balance_self(int cpu, int flag) +static int select_task_rq_fair(struct task_struct *p, int flag, int sync) { struct task_struct *t = current; struct sched_domain *tmp, *sd = NULL; + int cpu = smp_processor_id(); + int prev_cpu = task_cpu(p); + int new_cpu = cpu; + int want_affine = 0; + + if (flag & SD_BALANCE_WAKE) { + if (sched_feat(AFFINE_WAKEUPS)) + want_affine = 1; + new_cpu = prev_cpu; + } for_each_domain(cpu, tmp) { /* @@ -1466,16 +1337,38 @@ static int sched_balance_self(int cpu, int flag) */ if (tmp->flags & SD_POWERSAVINGS_BALANCE) break; - if (tmp->flags & flag) - sd = tmp; - } - if (sd) - update_shares(sd); + switch (flag) { + case SD_BALANCE_WAKE: + if (!sched_feat(LB_WAKEUP_UPDATE)) + break; + case SD_BALANCE_FORK: + case SD_BALANCE_EXEC: + if (root_task_group_empty()) + break; + update_shares(tmp); + default: + break; + } + + if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && + cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { + + if (wake_affine(tmp, p, sync)) + return cpu; + + want_affine = 0; + } + + if (!(tmp->flags & flag)) + continue; + + sd = tmp; + } while (sd) { struct sched_group *group; - int new_cpu, weight; + int weight; if (!(sd->flags & flag)) { sd = sd->child; @@ -1508,7 +1401,7 @@ static int sched_balance_self(int cpu, int flag) /* while loop will break here if sd == NULL */ } - return cpu; + return new_cpu; } #endif /* CONFIG_SMP */ -- cgit v1.2.2 From ae154be1f34a674e6cbb43ccf6e442f56acd7a70 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2009 14:40:57 +0200 Subject: sched: Weaken SD_POWERSAVINGS_BALANCE One of the problems of power-saving balancing is that under certain scenarios it is too slow and allows tons of real work to pile up. Avoid this by ignoring the powersave stuff when there's real work to be done. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 40 ++++++++++++++++++++-------------------- kernel/sched_fair.c | 21 ++++++++++++++++++--- 2 files changed, 38 insertions(+), 23 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 6c819f338b11..f0ccb8b926c8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1538,6 +1538,26 @@ static unsigned long target_load(int cpu, int type) return max(rq->cpu_load[type-1], total); } +static struct sched_group *group_of(int cpu) +{ + struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd); + + if (!sd) + return NULL; + + return sd->groups; +} + +static unsigned long power_of(int cpu) +{ + struct sched_group *group = group_of(cpu); + + if (!group) + return SCHED_LOAD_SCALE; + + return group->cpu_power; +} + static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); static unsigned long cpu_avg_load_per_task(int cpu) @@ -3982,26 +4002,6 @@ ret: return NULL; } -static struct sched_group *group_of(int cpu) -{ - struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd); - - if (!sd) - return NULL; - - return sd->groups; -} - -static unsigned long power_of(int cpu) -{ - struct sched_group *group = group_of(cpu); - - if (!group) - return SCHED_LOAD_SCALE; - - return group->cpu_power; -} - /* * find_busiest_queue - find the busiest runqueue among the cpus in group. */ diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 09d19f77eb3a..eaa00014b499 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1333,10 +1333,25 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) for_each_domain(cpu, tmp) { /* - * If power savings logic is enabled for a domain, stop there. + * If power savings logic is enabled for a domain, see if we + * are not overloaded, if so, don't balance wider. */ - if (tmp->flags & SD_POWERSAVINGS_BALANCE) - break; + if (tmp->flags & SD_POWERSAVINGS_BALANCE) { + unsigned long power = 0; + unsigned long nr_running = 0; + unsigned long capacity; + int i; + + for_each_cpu(i, sched_domain_span(tmp)) { + power += power_of(i); + nr_running += cpu_rq(i)->cfs.nr_running; + } + + capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE); + + if (nr_running/2 < capacity) + break; + } switch (flag) { case SD_BALANCE_WAKE: -- cgit v1.2.2 From 83f54960c11a14942ab00b54c51e91906b9d8235 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2009 18:18:47 +0200 Subject: sched: for_each_domain() vs RCU for_each_domain() uses RCU to serialize the sched_domains, except it doesn't actually use rcu_read_lock() and instead relies on disabling preemption -> FAIL. XXX: audit other sched_domain code. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index eaa00014b499..43dc6d1d9e88 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1331,6 +1331,7 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) new_cpu = prev_cpu; } + rcu_read_lock(); for_each_domain(cpu, tmp) { /* * If power savings logic is enabled for a domain, see if we @@ -1369,8 +1370,10 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { - if (wake_affine(tmp, p, sync)) - return cpu; + if (wake_affine(tmp, p, sync)) { + new_cpu = cpu; + goto out; + } want_affine = 0; } @@ -1416,6 +1419,8 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) /* while loop will break here if sd == NULL */ } +out: + rcu_read_unlock(); return new_cpu; } #endif /* CONFIG_SMP */ -- cgit v1.2.2 From d7c33c4930f569caf6b2ece597432853c4151a45 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 11 Sep 2009 12:45:38 +0200 Subject: sched: Fix task affinity for select_task_rq_fair While merging select_task_rq_fair() and sched_balance_self() I made a mistake that leads to testing the wrong task affinty. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 43dc6d1d9e88..8b3eddbcf9a4 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1318,7 +1318,6 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) */ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) { - struct task_struct *t = current; struct sched_domain *tmp, *sd = NULL; int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); @@ -1393,13 +1392,13 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) continue; } - group = find_idlest_group(sd, t, cpu); + group = find_idlest_group(sd, p, cpu); if (!group) { sd = sd->child; continue; } - new_cpu = find_idlest_cpu(group, t, cpu); + new_cpu = find_idlest_cpu(group, p, cpu); if (new_cpu == -1 || new_cpu == cpu) { /* Now try balancing at a lower domain level of cpu */ sd = sd->child; -- cgit v1.2.2 From 78e7ed53c9f42f04f9401ada6f7047db60781676 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 3 Sep 2009 13:16:51 +0200 Subject: sched: Tweak wake_idx When merging select_task_rq_fair() and sched_balance_self() we lost the use of wake_idx, restore that and set them to 0 to make wake balancing more aggressive. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 8b3eddbcf9a4..19593568031a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1232,12 +1232,27 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) * domain. */ static struct sched_group * -find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) +find_idlest_group(struct sched_domain *sd, struct task_struct *p, + int this_cpu, int flag) { struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; unsigned long min_load = ULONG_MAX, this_load = 0; - int load_idx = sd->forkexec_idx; int imbalance = 100 + (sd->imbalance_pct-100)/2; + int load_idx = 0; + + switch (flag) { + case SD_BALANCE_FORK: + case SD_BALANCE_EXEC: + load_idx = sd->forkexec_idx; + break; + + case SD_BALANCE_WAKE: + load_idx = sd->wake_idx; + break; + + default: + break; + } do { unsigned long load, avg_load; @@ -1392,7 +1407,7 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) continue; } - group = find_idlest_group(sd, p, cpu); + group = find_idlest_group(sd, p, cpu, flag); if (!group) { sd = sd->child; continue; -- cgit v1.2.2 From 0ec9fab3d186d9cbb00c0f694d4a260d07c198d9 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Tue, 15 Sep 2009 15:07:03 +0200 Subject: sched: Improve latencies and throughput Make the idle balancer more agressive, to improve a x264 encoding workload provided by Jason Garrett-Glaser: NEXT_BUDDY NO_LB_BIAS encoded 600 frames, 252.82 fps, 22096.60 kb/s encoded 600 frames, 250.69 fps, 22096.60 kb/s encoded 600 frames, 245.76 fps, 22096.60 kb/s NO_NEXT_BUDDY LB_BIAS encoded 600 frames, 344.44 fps, 22096.60 kb/s encoded 600 frames, 346.66 fps, 22096.60 kb/s encoded 600 frames, 352.59 fps, 22096.60 kb/s NO_NEXT_BUDDY NO_LB_BIAS encoded 600 frames, 425.75 fps, 22096.60 kb/s encoded 600 frames, 425.45 fps, 22096.60 kb/s encoded 600 frames, 422.49 fps, 22096.60 kb/s Peter pointed out that this is better done via newidle_idx, not via LB_BIAS, newidle balancing should look for where there is load _now_, not where there was load 2 ticks ago. Worst-case latencies are improved as well as no buddies means less vruntime spread. (as per prior lkml discussions) This change improves kbuild-peak parallelism as well. Reported-by: Jason Garrett-Glaser Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1253011667.9128.16.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- kernel/sched_features.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 891ea0f72b46..e98c2e8de1d5 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -67,7 +67,7 @@ SCHED_FEAT(AFFINE_WAKEUPS, 1) * wakeup-preemption), since its likely going to consume data we * touched, increases cache locality. */ -SCHED_FEAT(NEXT_BUDDY, 1) +SCHED_FEAT(NEXT_BUDDY, 0) /* * Prefer to schedule the task that ran last (when we did -- cgit v1.2.2 From d6a59aa3a2b1ca8411884c833a313b33b5f76e20 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 2 Sep 2009 13:28:02 +0200 Subject: sched: Provide arch_scale_freq_power Provide an ach specific hook for cpufreq based scaling of cpu_power. Signed-off-by: Peter Zijlstra [ego@in.ibm.com: spotting bugs] LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index f0ccb8b926c8..c210321adcb9 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3552,7 +3552,18 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, } #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ -unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) + +unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu) +{ + return SCHED_LOAD_SCALE; +} + +unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu) +{ + return default_scale_freq_power(sd, cpu); +} + +unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) { unsigned long weight = cpumask_weight(sched_domain_span(sd)); unsigned long smt_gain = sd->smt_gain; @@ -3562,6 +3573,11 @@ unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) return smt_gain; } +unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) +{ + return default_scale_smt_power(sd, cpu); +} + unsigned long scale_rt_power(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -3586,7 +3602,8 @@ static void update_cpu_power(struct sched_domain *sd, int cpu) unsigned long power = SCHED_LOAD_SCALE; struct sched_group *sdg = sd->groups; - /* here we could scale based on cpufreq */ + power *= arch_scale_freq_power(sd, cpu); + power >>= SCHED_LOAD_SHIFT; if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { power *= arch_scale_smt_power(sd, cpu); -- cgit v1.2.2 From 8e6598af3f35629c37249a610cf13e73f70db279 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 3 Sep 2009 13:20:03 +0200 Subject: sched: Feature to disable APERF/MPERF cpu_power I suspect a feed-back loop between cpuidle and the aperf/mperf cpu_power bits, where when we have idle C-states lower the ratio, which leads to lower cpu_power and then less load, which generates more idle time, etc.. Put in a knob to disable it. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 12 ++++++++++-- kernel/sched_features.h | 5 +++++ 2 files changed, 15 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index c210321adcb9..e8e603bf8761 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3602,11 +3602,19 @@ static void update_cpu_power(struct sched_domain *sd, int cpu) unsigned long power = SCHED_LOAD_SCALE; struct sched_group *sdg = sd->groups; - power *= arch_scale_freq_power(sd, cpu); + if (sched_feat(ARCH_POWER)) + power *= arch_scale_freq_power(sd, cpu); + else + power *= default_scale_freq_power(sd, cpu); + power >>= SCHED_LOAD_SHIFT; if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { - power *= arch_scale_smt_power(sd, cpu); + if (sched_feat(ARCH_POWER)) + power *= arch_scale_smt_power(sd, cpu); + else + power *= default_scale_smt_power(sd, cpu); + power >>= SCHED_LOAD_SHIFT; } diff --git a/kernel/sched_features.h b/kernel/sched_features.h index e98c2e8de1d5..294e10edd3c8 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -82,6 +82,11 @@ SCHED_FEAT(LAST_BUDDY, 1) */ SCHED_FEAT(CACHE_HOT_BUDDY, 1) +/* + * Use arch dependent cpu power functions + */ +SCHED_FEAT(ARCH_POWER, 0) + SCHED_FEAT(HRTICK, 0) SCHED_FEAT(DOUBLE_TICK, 0) SCHED_FEAT(LB_BIAS, 1) -- cgit v1.2.2 From 0763a660a84220cc3900fd32abdd7ad109e2278d Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 14 Sep 2009 19:37:39 +0200 Subject: sched: Rename select_task_rq() argument In order to be able to rename the sync argument, we need to rename the current flag argument. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 14 +++++++------- kernel/sched_idletask.c | 2 +- kernel/sched_rt.c | 4 ++-- 3 files changed, 10 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 19593568031a..b554e63c521a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1331,7 +1331,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) * * preempt must be disabled. */ -static int select_task_rq_fair(struct task_struct *p, int flag, int sync) +static int select_task_rq_fair(struct task_struct *p, int sd_flag, int sync) { struct sched_domain *tmp, *sd = NULL; int cpu = smp_processor_id(); @@ -1339,7 +1339,7 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) int new_cpu = cpu; int want_affine = 0; - if (flag & SD_BALANCE_WAKE) { + if (sd_flag & SD_BALANCE_WAKE) { if (sched_feat(AFFINE_WAKEUPS)) want_affine = 1; new_cpu = prev_cpu; @@ -1368,7 +1368,7 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) break; } - switch (flag) { + switch (sd_flag) { case SD_BALANCE_WAKE: if (!sched_feat(LB_WAKEUP_UPDATE)) break; @@ -1392,7 +1392,7 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) want_affine = 0; } - if (!(tmp->flags & flag)) + if (!(tmp->flags & sd_flag)) continue; sd = tmp; @@ -1402,12 +1402,12 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) struct sched_group *group; int weight; - if (!(sd->flags & flag)) { + if (!(sd->flags & sd_flag)) { sd = sd->child; continue; } - group = find_idlest_group(sd, p, cpu, flag); + group = find_idlest_group(sd, p, cpu, sd_flag); if (!group) { sd = sd->child; continue; @@ -1427,7 +1427,7 @@ static int select_task_rq_fair(struct task_struct *p, int flag, int sync) for_each_domain(cpu, tmp) { if (weight <= cpumask_weight(sched_domain_span(tmp))) break; - if (tmp->flags & flag) + if (tmp->flags & sd_flag) sd = tmp; } /* while loop will break here if sd == NULL */ diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 99b2f0337609..9ff7697e5dc4 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -6,7 +6,7 @@ */ #ifdef CONFIG_SMP -static int select_task_rq_idle(struct task_struct *p, int flag, int sync) +static int select_task_rq_idle(struct task_struct *p, int sd_flag, int sync) { return task_cpu(p); /* IDLE tasks as never migrated */ } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 438380810ac4..97c53f3f51a7 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -938,11 +938,11 @@ static void yield_task_rt(struct rq *rq) #ifdef CONFIG_SMP static int find_lowest_rq(struct task_struct *task); -static int select_task_rq_rt(struct task_struct *p, int flag, int sync) +static int select_task_rq_rt(struct task_struct *p, int sd_flag, int sync) { struct rq *rq = task_rq(p); - if (flag != SD_BALANCE_WAKE) + if (sd_flag != SD_BALANCE_WAKE) return smp_processor_id(); /* -- cgit v1.2.2 From 7d47872146398dbede13223299fe1cb368ebc781 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 14 Sep 2009 19:55:44 +0200 Subject: sched: Rename sync arguments In order to extend the functions to have more than 1 flag (sync), rename the argument to flags, and explicitly define a WF_ space for individual flags. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 30 ++++++++++++++++-------------- kernel/sched_fair.c | 6 ++++-- kernel/sched_idletask.c | 4 ++-- kernel/sched_rt.c | 4 ++-- 4 files changed, 24 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index e8e603bf8761..4da335cec8ee 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -636,9 +636,10 @@ struct rq { static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) +static inline +void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) { - rq->curr->sched_class->check_preempt_curr(rq, p, sync); + rq->curr->sched_class->check_preempt_curr(rq, p, flags); } static inline int cpu_of(struct rq *rq) @@ -2318,14 +2319,15 @@ void task_oncpu_function_call(struct task_struct *p, * * returns failure only if the task is already active. */ -static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) +static int try_to_wake_up(struct task_struct *p, unsigned int state, + int wake_flags) { int cpu, orig_cpu, this_cpu, success = 0; unsigned long flags; struct rq *rq; if (!sched_feat(SYNC_WAKEUPS)) - sync = 0; + wake_flags &= ~WF_SYNC; this_cpu = get_cpu(); @@ -2352,7 +2354,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) p->state = TASK_WAKING; task_rq_unlock(rq, &flags); - cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, sync); + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags); if (cpu != orig_cpu) set_task_cpu(p, cpu); @@ -2378,7 +2380,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) out_activate: #endif /* CONFIG_SMP */ schedstat_inc(p, se.nr_wakeups); - if (sync) + if (wake_flags & WF_SYNC) schedstat_inc(p, se.nr_wakeups_sync); if (orig_cpu != cpu) schedstat_inc(p, se.nr_wakeups_migrate); @@ -2407,7 +2409,7 @@ out_activate: out_running: trace_sched_wakeup(rq, p, success); - check_preempt_curr(rq, p, sync); + check_preempt_curr(rq, p, wake_flags); p->state = TASK_RUNNING; #ifdef CONFIG_SMP @@ -5562,10 +5564,10 @@ asmlinkage void __sched preempt_schedule_irq(void) #endif /* CONFIG_PREEMPT */ -int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, +int default_wake_function(wait_queue_t *curr, unsigned mode, int flags, void *key) { - return try_to_wake_up(curr->private, mode, sync); + return try_to_wake_up(curr->private, mode, flags); } EXPORT_SYMBOL(default_wake_function); @@ -5579,14 +5581,14 @@ EXPORT_SYMBOL(default_wake_function); * zero in this (rare) case, and we handle it by continuing to scan the queue. */ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, int sync, void *key) + int nr_exclusive, int flags, void *key) { wait_queue_t *curr, *next; list_for_each_entry_safe(curr, next, &q->task_list, task_list) { unsigned flags = curr->flags; - if (curr->func(curr, mode, sync, key) && + if (curr->func(curr, mode, flags, key) && (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) break; } @@ -5647,16 +5649,16 @@ void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, void *key) { unsigned long flags; - int sync = 1; + int wake_flags = WF_SYNC; if (unlikely(!q)) return; if (unlikely(!nr_exclusive)) - sync = 0; + wake_flags = 0; spin_lock_irqsave(&q->lock, flags); - __wake_up_common(q, mode, nr_exclusive, sync, key); + __wake_up_common(q, mode, nr_exclusive, wake_flags, key); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL_GPL(__wake_up_sync_key); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index b554e63c521a..007958e3c93a 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1331,13 +1331,14 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) * * preempt must be disabled. */ -static int select_task_rq_fair(struct task_struct *p, int sd_flag, int sync) +static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) { struct sched_domain *tmp, *sd = NULL; int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); int new_cpu = cpu; int want_affine = 0; + int sync = flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { if (sched_feat(AFFINE_WAKEUPS)) @@ -1548,11 +1549,12 @@ static void set_next_buddy(struct sched_entity *se) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) +static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int flags) { struct task_struct *curr = rq->curr; struct sched_entity *se = &curr->se, *pse = &p->se; struct cfs_rq *cfs_rq = task_cfs_rq(curr); + int sync = flags & WF_SYNC; update_curr(cfs_rq); diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 9ff7697e5dc4..a8b448af004b 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -6,7 +6,7 @@ */ #ifdef CONFIG_SMP -static int select_task_rq_idle(struct task_struct *p, int sd_flag, int sync) +static int select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) { return task_cpu(p); /* IDLE tasks as never migrated */ } @@ -14,7 +14,7 @@ static int select_task_rq_idle(struct task_struct *p, int sd_flag, int sync) /* * Idle tasks are unconditionally rescheduled: */ -static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sync) +static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) { resched_task(rq->idle); } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 97c53f3f51a7..13de7126a6ab 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -938,7 +938,7 @@ static void yield_task_rt(struct rq *rq) #ifdef CONFIG_SMP static int find_lowest_rq(struct task_struct *task); -static int select_task_rq_rt(struct task_struct *p, int sd_flag, int sync) +static int select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) { struct rq *rq = task_rq(p); @@ -1002,7 +1002,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) +static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) { if (p->prio < rq->curr->prio) { resched_task(rq->curr); -- cgit v1.2.2 From a7558e01056f5191ff2ecff53b075dcb9e484188 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 14 Sep 2009 20:02:34 +0200 Subject: sched: Add WF_FORK Avoid the cache buddies from biasing the time distribution away from fork()ers. Normally the next buddy will be the preferred scheduling target, but this makes fork()s prefer to run the new child, whereas we prefer to run the parent, since that will generate more work. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- kernel/sched_fair.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 4da335cec8ee..0d4c4fea3317 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2602,7 +2602,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) inc_nr_running(rq); } trace_sched_wakeup_new(rq, p, 1); - check_preempt_curr(rq, p, 0); + check_preempt_curr(rq, p, WF_FORK); #ifdef CONFIG_SMP if (p->sched_class->task_wake_up) p->sched_class->task_wake_up(rq, p); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 007958e3c93a..6766959c7f44 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1580,7 +1580,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int flags */ if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle)) set_last_buddy(se); - if (sched_feat(NEXT_BUDDY)) + if (sched_feat(NEXT_BUDDY) && !(flags & WF_FORK)) set_next_buddy(pse); /* -- cgit v1.2.2 From 6ca6cca31ddc7cc8b1dc38b12d7593d2667defe8 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 15 Sep 2009 12:24:22 -0400 Subject: tracing: optimize global_trace_clock cachelines The prev_trace_clock_time is only read or written to when the trace_clock_lock is taken. For better perfomance, they should share the same cache line. Reported-by: Peter Zijlstra Signed-off-by: Steven Rostedt --- kernel/trace/trace_clock.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c index b588fd81f7f9..20c5f92e28a8 100644 --- a/kernel/trace/trace_clock.c +++ b/kernel/trace/trace_clock.c @@ -66,10 +66,14 @@ u64 notrace trace_clock(void) * Used by plugins that need globally coherent timestamps. */ -static u64 prev_trace_clock_time; - -static raw_spinlock_t trace_clock_lock ____cacheline_aligned_in_smp = - (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; +/* keep prev_time and lock in the same cacheline. */ +static struct { + u64 prev_time; + raw_spinlock_t lock; +} trace_clock_struct ____cacheline_aligned_in_smp = + { + .lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED, + }; u64 notrace trace_clock_global(void) { @@ -88,19 +92,19 @@ u64 notrace trace_clock_global(void) if (unlikely(in_nmi())) goto out; - __raw_spin_lock(&trace_clock_lock); + __raw_spin_lock(&trace_clock_struct.lock); /* * TODO: if this happens often then maybe we should reset - * my_scd->clock to prev_trace_clock_time+1, to make sure + * my_scd->clock to prev_time+1, to make sure * we start ticking with the local clock from now on? */ - if ((s64)(now - prev_trace_clock_time) < 0) - now = prev_trace_clock_time + 1; + if ((s64)(now - trace_clock_struct.prev_time) < 0) + now = trace_clock_struct.prev_time + 1; - prev_trace_clock_time = now; + trace_clock_struct.prev_time = now; - __raw_spin_unlock(&trace_clock_lock); + __raw_spin_unlock(&trace_clock_struct.lock); out: raw_local_irq_restore(flags); -- cgit v1.2.2 From a56af87648054089d89874b52e3fc23ed4f274ad Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Sun, 12 Jul 2009 21:44:55 +0800 Subject: driver-core: move dma-coherent.c from kernel to driver/base Placing dma-coherent.c in driver/base is better than in kernel, since it contains code to do per-device coherent dma memory handling. Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman --- kernel/Makefile | 1 - kernel/dma-coherent.c | 176 -------------------------------------------------- 2 files changed, 177 deletions(-) delete mode 100644 kernel/dma-coherent.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 961379caf666..3d9c7e27e3f9 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -90,7 +90,6 @@ obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o -obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o obj-$(CONFIG_FUNCTION_TRACER) += trace/ obj-$(CONFIG_TRACING) += trace/ obj-$(CONFIG_X86_DS) += trace/ diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c deleted file mode 100644 index 962a3b574f21..000000000000 --- a/kernel/dma-coherent.c +++ /dev/null @@ -1,176 +0,0 @@ -/* - * Coherent per-device memory handling. - * Borrowed from i386 - */ -#include -#include - -struct dma_coherent_mem { - void *virt_base; - u32 device_base; - int size; - int flags; - unsigned long *bitmap; -}; - -int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr, - dma_addr_t device_addr, size_t size, int flags) -{ - void __iomem *mem_base = NULL; - int pages = size >> PAGE_SHIFT; - int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); - - if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0) - goto out; - if (!size) - goto out; - if (dev->dma_mem) - goto out; - - /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */ - - mem_base = ioremap(bus_addr, size); - if (!mem_base) - goto out; - - dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); - if (!dev->dma_mem) - goto out; - dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); - if (!dev->dma_mem->bitmap) - goto free1_out; - - dev->dma_mem->virt_base = mem_base; - dev->dma_mem->device_base = device_addr; - dev->dma_mem->size = pages; - dev->dma_mem->flags = flags; - - if (flags & DMA_MEMORY_MAP) - return DMA_MEMORY_MAP; - - return DMA_MEMORY_IO; - - free1_out: - kfree(dev->dma_mem); - out: - if (mem_base) - iounmap(mem_base); - return 0; -} -EXPORT_SYMBOL(dma_declare_coherent_memory); - -void dma_release_declared_memory(struct device *dev) -{ - struct dma_coherent_mem *mem = dev->dma_mem; - - if (!mem) - return; - dev->dma_mem = NULL; - iounmap(mem->virt_base); - kfree(mem->bitmap); - kfree(mem); -} -EXPORT_SYMBOL(dma_release_declared_memory); - -void *dma_mark_declared_memory_occupied(struct device *dev, - dma_addr_t device_addr, size_t size) -{ - struct dma_coherent_mem *mem = dev->dma_mem; - int pos, err; - - size += device_addr & ~PAGE_MASK; - - if (!mem) - return ERR_PTR(-EINVAL); - - pos = (device_addr - mem->device_base) >> PAGE_SHIFT; - err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); - if (err != 0) - return ERR_PTR(err); - return mem->virt_base + (pos << PAGE_SHIFT); -} -EXPORT_SYMBOL(dma_mark_declared_memory_occupied); - -/** - * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area - * - * @dev: device from which we allocate memory - * @size: size of requested memory area - * @dma_handle: This will be filled with the correct dma handle - * @ret: This pointer will be filled with the virtual address - * to allocated area. - * - * This function should be only called from per-arch dma_alloc_coherent() - * to support allocation from per-device coherent memory pools. - * - * Returns 0 if dma_alloc_coherent should continue with allocating from - * generic memory areas, or !0 if dma_alloc_coherent should return @ret. - */ -int dma_alloc_from_coherent(struct device *dev, ssize_t size, - dma_addr_t *dma_handle, void **ret) -{ - struct dma_coherent_mem *mem; - int order = get_order(size); - int pageno; - - if (!dev) - return 0; - mem = dev->dma_mem; - if (!mem) - return 0; - - *ret = NULL; - - if (unlikely(size > (mem->size << PAGE_SHIFT))) - goto err; - - pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); - if (unlikely(pageno < 0)) - goto err; - - /* - * Memory was found in the per-device area. - */ - *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); - *ret = mem->virt_base + (pageno << PAGE_SHIFT); - memset(*ret, 0, size); - - return 1; - -err: - /* - * In the case where the allocation can not be satisfied from the - * per-device area, try to fall back to generic memory if the - * constraints allow it. - */ - return mem->flags & DMA_MEMORY_EXCLUSIVE; -} -EXPORT_SYMBOL(dma_alloc_from_coherent); - -/** - * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool - * @dev: device from which the memory was allocated - * @order: the order of pages allocated - * @vaddr: virtual address of allocated pages - * - * This checks whether the memory was allocated from the per-device - * coherent memory pool and if so, releases that memory. - * - * Returns 1 if we correctly released the memory, or 0 if - * dma_release_coherent() should proceed with releasing memory from - * generic pools. - */ -int dma_release_from_coherent(struct device *dev, int order, void *vaddr) -{ - struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; - - if (mem && vaddr >= mem->virt_base && vaddr < - (mem->virt_base + (mem->size << PAGE_SHIFT))) { - int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; - - bitmap_release_region(mem->bitmap, page, order); - return 1; - } - return 0; -} -EXPORT_SYMBOL(dma_release_from_coherent); -- cgit v1.2.2 From 63859d4fe4c97b737e7adbfe60acb1c2b2e668cb Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 15 Sep 2009 19:14:42 +0200 Subject: sched: Fix sync wakeups again The sync argument rename to introduce WF_* broke stuff by missing a local alias for an argument in __wake_up_common, fix it by using the more descriptive wake_flags name. This restores WF_SYNC propagation, which fixes wake_affine() behaviour, which fixes pipe-test. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 0d4c4fea3317..af04ede6dd2f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5564,10 +5564,10 @@ asmlinkage void __sched preempt_schedule_irq(void) #endif /* CONFIG_PREEMPT */ -int default_wake_function(wait_queue_t *curr, unsigned mode, int flags, +int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, void *key) { - return try_to_wake_up(curr->private, mode, flags); + return try_to_wake_up(curr->private, mode, wake_flags); } EXPORT_SYMBOL(default_wake_function); @@ -5581,14 +5581,14 @@ EXPORT_SYMBOL(default_wake_function); * zero in this (rare) case, and we handle it by continuing to scan the queue. */ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, int flags, void *key) + int nr_exclusive, int wake_flags, void *key) { wait_queue_t *curr, *next; list_for_each_entry_safe(curr, next, &q->task_list, task_list) { unsigned flags = curr->flags; - if (curr->func(curr, mode, flags, key) && + if (curr->func(curr, mode, wake_flags, key) && (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) break; } -- cgit v1.2.2 From e69b0f1b41c0e57bb1e29100b5810a5914efcb45 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 15 Sep 2009 19:38:52 +0200 Subject: sched: Add a few SYNC hint knobs to play with Currently we use overlap to weaken the SYNC hint, but allow it to set the hint as well. echo NO_SYNC_WAKEUP > /debug/sched_features echo SYNC_MORE > /debug/sched_features preserves pipe-test behaviour without using the WF_SYNC hint. Worth playing with on more workloads... Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 14 +++++++++++--- kernel/sched_features.h | 10 ++++++++++ 2 files changed, 21 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 6766959c7f44..280892e9d85e 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1165,9 +1165,17 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) load = source_load(prev_cpu, idx); this_load = target_load(this_cpu, idx); - if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost || - p->se.avg_overlap > sysctl_sched_migration_cost)) - sync = 0; + if (sync) { + if (sched_feat(SYNC_LESS) && + (curr->se.avg_overlap > sysctl_sched_migration_cost || + p->se.avg_overlap > sysctl_sched_migration_cost)) + sync = 0; + } else { + if (sched_feat(SYNC_MORE) && + (curr->se.avg_overlap < sysctl_sched_migration_cost && + p->se.avg_overlap < sysctl_sched_migration_cost)) + sync = 1; + } /* * If sync wakeup then subtract the (maximum possible) diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 294e10edd3c8..70115c69c7a9 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -62,6 +62,16 @@ SCHED_FEAT(SYNC_WAKEUPS, 1) */ SCHED_FEAT(AFFINE_WAKEUPS, 1) +/* + * Weaken SYNC hint based on overlap + */ +SCHED_FEAT(SYNC_LESS, 1) + +/* + * Add SYNC hint based on overlap + */ +SCHED_FEAT(SYNC_MORE, 0) + /* * Prefer to schedule the task we woke last (assuming it failed * wakeup-preemption), since its likely going to consume data we -- cgit v1.2.2 From cb684b5bcd6a79ae7e2360c6b158c4aa7b0a293a Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 15 Sep 2009 21:53:11 +0200 Subject: block: fix linkage problem with blk_iopoll and !CONFIG_BLOCK kernel/built-in.o:(.data+0x17b0): undefined reference to `blk_iopoll_enabled' Since the extern declaration makes the compile work, but the actual symbol is missing when block/blk-iopoll.o isn't linked in. Signed-off-by: Jens Axboe --- kernel/sysctl.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6bb59f707402..1a631ba684a4 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -91,7 +91,9 @@ extern int sysctl_nr_trim_pages; #ifdef CONFIG_RCU_TORTURE_TEST extern int rcutorture_runnable; #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */ +#ifdef CONFIG_BLOCK extern int blk_iopoll_enabled; +#endif /* Constants used for minimum and maximum */ #ifdef CONFIG_DETECT_SOFTLOCKUP @@ -998,6 +1000,7 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dointvec, }, #endif +#ifdef CONFIG_BLOCK { .ctl_name = CTL_UNNUMBERED, .procname = "blk_iopoll", @@ -1006,6 +1009,7 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, +#endif /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt -- cgit v1.2.2 From 59abf02644c45f1591e1374ee7bb45dc757fcb88 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 16 Sep 2009 08:28:30 +0200 Subject: sched: Add SD_PREFER_LOCAL And turn it on for NUMA and MC domains. This improves locality in balancing decisions by keeping up to capacity amount of tasks local before looking for idle CPUs. (and twice the capacity if SD_POWERSAVINGS_BALANCE is set.) Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 280892e9d85e..a37f311f436e 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1360,7 +1360,7 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) * If power savings logic is enabled for a domain, see if we * are not overloaded, if so, don't balance wider. */ - if (tmp->flags & SD_POWERSAVINGS_BALANCE) { + if (tmp->flags & (SD_POWERSAVINGS_BALANCE|SD_PREFER_LOCAL)) { unsigned long power = 0; unsigned long nr_running = 0; unsigned long capacity; @@ -1373,7 +1373,10 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE); - if (nr_running/2 < capacity) + if (tmp->flags & SD_POWERSAVINGS_BALANCE) + nr_running /= 2; + + if (nr_running < capacity) break; } -- cgit v1.2.2 From 51e0304ce6e55a6e59658558916b4f74da085ff0 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 16 Sep 2009 08:54:45 +0200 Subject: sched: Implement a gentler fair-sleepers feature Add back FAIR_SLEEPERS and GENTLE_FAIR_SLEEPERS. FAIR_SLEEPERS is the old logic: credit sleepers with their sleep time. GENTLE_FAIR_SLEEPERS dampens this a bit: 50% of their sleep time gets credited. The hope here is to still give the benefits of fair-sleepers logic (quick wakeups, etc.) while not allow them to have 100% of their sleep time as if they were running. Cc: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 9 ++++++++- kernel/sched_features.h | 9 ++++++++- 2 files changed, 16 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a37f311f436e..acf16a8d934b 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -711,7 +711,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) if (!initial) { /* sleeps upto a single latency don't count. */ - if (sched_feat(NEW_FAIR_SLEEPERS)) { + if (sched_feat(FAIR_SLEEPERS)) { unsigned long thresh = sysctl_sched_latency; /* @@ -725,6 +725,13 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) task_of(se)->policy != SCHED_IDLE)) thresh = calc_delta_fair(thresh, se); + /* + * Halve their sleep time's effect, to allow + * for a gentler effect of sleepers: + */ + if (sched_feat(GENTLE_FAIR_SLEEPERS)) + thresh >>= 1; + vruntime -= thresh; } } diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 70115c69c7a9..fd375675f834 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -3,7 +3,14 @@ * considers the task to be running during that period. This gives it * a service deficit on wakeup, allowing it to run sooner. */ -SCHED_FEAT(NEW_FAIR_SLEEPERS, 0) +SCHED_FEAT(FAIR_SLEEPERS, 1) + +/* + * Only give sleepers 50% of their service deficit. This allows + * them to run sooner, but does not allow tons of sleepers to + * rip the spread apart. + */ +SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1) /* * By not normalizing the sleep time, heavy tasks get an effective -- cgit v1.2.2 From 4db96cf077aa938b11fe7ac79ecc9b29ec00fbab Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 16 Sep 2009 11:50:14 +0200 Subject: HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process This allows processes to override their early/late kill behaviour on hardware memory errors. Typically applications which are memory error aware is better of with early kill (see the error as soon as possible), all others with late kill (only see the error when the error is really impacting execution) There's a global sysctl, but this way an application can set its specific policy. We're using two bits, one to signify that the process stated its intention and that I also made the prctl future proof by enforcing the unused arguments are 0. The state is inherited to children. Note this makes us officially run out of process flags on 32bit, but the next patch can easily add another field. Manpage patch will be supplied separately. Signed-off-by: Andi Kleen --- kernel/sys.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'kernel') diff --git a/kernel/sys.c b/kernel/sys.c index b3f1097c76fa..41e02eff3398 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1528,6 +1528,28 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, current->timer_slack_ns = arg2; error = 0; break; + case PR_MCE_KILL: + if (arg4 | arg5) + return -EINVAL; + switch (arg2) { + case 0: + if (arg3 != 0) + return -EINVAL; + current->flags &= ~PF_MCE_PROCESS; + break; + case 1: + current->flags |= PF_MCE_PROCESS; + if (arg3 != 0) + current->flags |= PF_MCE_EARLY; + else + current->flags &= ~PF_MCE_EARLY; + break; + default: + return -EINVAL; + } + error = 0; + break; + default: error = -EINVAL; break; -- cgit v1.2.2 From 6a46079cf57a7f7758e8b926980a4f852f89b34d Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 16 Sep 2009 11:50:15 +0200 Subject: HWPOISON: The high level memory error handler in the VM v7 Add the high level memory handler that poisons pages that got corrupted by hardware (typically by a two bit flip in a DIMM or a cache) on the Linux level. The goal is to prevent everyone from accessing these pages in the future. This done at the VM level by marking a page hwpoisoned and doing the appropriate action based on the type of page it is. The code that does this is portable and lives in mm/memory-failure.c To quote the overview comment: High level machine check handler. Handles pages reported by the hardware as being corrupted usually due to a 2bit ECC memory or cache failure. This focuses on pages detected as corrupted in the background. When the current CPU tries to consume corruption the currently running process can just be killed directly instead. This implies that if the error cannot be handled for some reason it's safe to just ignore it because no corruption has been consumed yet. Instead when that happens another machine check will happen. Handles page cache pages in various states. The tricky part here is that we can access any page asynchronous to other VM users, because memory failures could happen anytime and anywhere, possibly violating some of their assumptions. This is why this code has to be extremely careful. Generally it tries to use normal locking rules, as in get the standard locks, even if that means the error handling takes potentially a long time. Some of the operations here are somewhat inefficient and have non linear algorithmic complexity, because the data structures have not been optimized for this case. This is in particular the case for the mapping from a vma to a process. Since this case is expected to be rare we hope we can get away with this. There are in principle two strategies to kill processes on poison: - just unmap the data and wait for an actual reference before killing - kill as soon as corruption is detected. Both have advantages and disadvantages and should be used in different situations. Right now both are implemented and can be switched with a new sysctl vm.memory_failure_early_kill The default is early kill. The patch does some rmap data structure walking on its own to collect processes to kill. This is unusual because normally all rmap data structure knowledge is in rmap.c only. I put it here for now to keep everything together and rmap knowledge has been seeping out anyways Includes contributions from Johannes Weiner, Chris Mason, Fengguang Wu, Nick Piggin (who did a lot of great work) and others. Cc: npiggin@suse.de Cc: riel@redhat.com Signed-off-by: Andi Kleen Acked-by: Rik van Riel Reviewed-by: Hidehiro Kawai --- kernel/sysctl.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6bb59f707402..eacae77ac9fc 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1372,6 +1372,31 @@ static struct ctl_table vm_table[] = { .mode = 0644, .proc_handler = &scan_unevictable_handler, }, +#ifdef CONFIG_MEMORY_FAILURE + { + .ctl_name = CTL_UNNUMBERED, + .procname = "memory_failure_early_kill", + .data = &sysctl_memory_failure_early_kill, + .maxlen = sizeof(sysctl_memory_failure_early_kill), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one, + }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "memory_failure_recovery", + .data = &sysctl_memory_failure_recovery, + .maxlen = sizeof(sysctl_memory_failure_recovery), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one, + }, +#endif + /* * NOTE: do not add new entries to this table unless you have read * Documentation/sysctl/ctl_unnumbered.txt -- cgit v1.2.2 From b36461da2a0389149d7f88f3cbc05a30d1db9faa Mon Sep 17 00:00:00 2001 From: Atsushi Tsuji Date: Tue, 15 Sep 2009 19:06:30 +0900 Subject: tracing: Fix minor bugs for __unregister_ftrace_function_probe Fix the condition of strcmp for "*". Also fix NULL pointer dereference when glob is NULL. Signed-off-by: Atsushi Tsuji LKML-Reference: <4AAF6726.5090905@bk.jp.nec.com> Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 8b23d5670088..f7ab7fc162cc 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2062,9 +2062,9 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, int i, len = 0; char *search; - if (glob && (strcmp(glob, "*") || !strlen(glob))) + if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) glob = NULL; - else { + else if (glob) { int not; type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); -- cgit v1.2.2 From 3b6408942206f940dd538e980e9904e48f4b64f8 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 16 Sep 2009 13:44:33 +0200 Subject: sched: Optimize cgroup vs wakeup a bit We don't need to call update_shares() for each domain we iterate, just got the largets one. However, we should call it before wake_affine() as well, so that that can use up-to-date values too. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 7 ------- kernel/sched_fair.c | 23 +++++++++-------------- kernel/sched_features.h | 2 +- 3 files changed, 10 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index af04ede6dd2f..5049d959bb26 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -376,13 +376,6 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) #else -#ifdef CONFIG_SMP -static int root_task_group_empty(void) -{ - return 1; -} -#endif - static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } static inline struct task_group *task_group(struct task_struct *p) { diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index acf16a8d934b..722d392b0dac 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1348,7 +1348,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) */ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) { - struct sched_domain *tmp, *sd = NULL; + struct sched_domain *tmp, *shares = NULL, *sd = NULL; int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); int new_cpu = cpu; @@ -1387,22 +1387,14 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) break; } - switch (sd_flag) { - case SD_BALANCE_WAKE: - if (!sched_feat(LB_WAKEUP_UPDATE)) - break; - case SD_BALANCE_FORK: - case SD_BALANCE_EXEC: - if (root_task_group_empty()) - break; - update_shares(tmp); - default: - break; - } - if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { + if (sched_feat(LB_SHARES_UPDATE)) { + update_shares(tmp); + shares = tmp; + } + if (wake_affine(tmp, p, sync)) { new_cpu = cpu; goto out; @@ -1417,6 +1409,9 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) sd = tmp; } + if (sd && sd != shares && sched_feat(LB_SHARES_UPDATE)) + update_shares(sd); + while (sd) { struct sched_group *group; int weight; diff --git a/kernel/sched_features.h b/kernel/sched_features.h index fd375675f834..d5059fd761d9 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -107,7 +107,7 @@ SCHED_FEAT(ARCH_POWER, 0) SCHED_FEAT(HRTICK, 0) SCHED_FEAT(DOUBLE_TICK, 0) SCHED_FEAT(LB_BIAS, 1) -SCHED_FEAT(LB_WAKEUP_UPDATE, 1) +SCHED_FEAT(LB_SHARES_UPDATE, 1) SCHED_FEAT(ASYM_EFF_LOAD, 1) /* -- cgit v1.2.2 From 5158f4e4428c6b8d52796b3b460e95796123a114 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 16 Sep 2009 13:46:59 +0200 Subject: sched: Clean up the load_idx selection in select_task_rq_fair Clean up the code a little. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 27 ++++++++------------------- 1 file changed, 8 insertions(+), 19 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 722d392b0dac..aeff40e7ec1b 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1248,26 +1248,11 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) */ static struct sched_group * find_idlest_group(struct sched_domain *sd, struct task_struct *p, - int this_cpu, int flag) + int this_cpu, int load_idx) { struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; unsigned long min_load = ULONG_MAX, this_load = 0; int imbalance = 100 + (sd->imbalance_pct-100)/2; - int load_idx = 0; - - switch (flag) { - case SD_BALANCE_FORK: - case SD_BALANCE_EXEC: - load_idx = sd->forkexec_idx; - break; - - case SD_BALANCE_WAKE: - load_idx = sd->wake_idx; - break; - - default: - break; - } do { unsigned long load, avg_load; @@ -1346,14 +1331,14 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) * * preempt must be disabled. */ -static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) +static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) { struct sched_domain *tmp, *shares = NULL, *sd = NULL; int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); int new_cpu = cpu; int want_affine = 0; - int sync = flags & WF_SYNC; + int sync = wake_flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { if (sched_feat(AFFINE_WAKEUPS)) @@ -1413,6 +1398,7 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) update_shares(sd); while (sd) { + int load_idx = sd->forkexec_idx; struct sched_group *group; int weight; @@ -1421,7 +1407,10 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int flags) continue; } - group = find_idlest_group(sd, p, cpu, sd_flag); + if (sd_flag & SD_BALANCE_WAKE) + load_idx = sd->wake_idx; + + group = find_idlest_group(sd, p, cpu, load_idx); if (!group) { sd = sd->child; continue; -- cgit v1.2.2 From 5a9b86f647a56862cdc0a1362bfb015ae921af7f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 16 Sep 2009 13:47:58 +0200 Subject: sched: Rename flags to wake_flags For consistencies sake, rename the argument (again). Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index aeff40e7ec1b..c741cd9d38de 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1551,12 +1551,12 @@ static void set_next_buddy(struct sched_entity *se) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int flags) +static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) { struct task_struct *curr = rq->curr; struct sched_entity *se = &curr->se, *pse = &p->se; struct cfs_rq *cfs_rq = task_cfs_rq(curr); - int sync = flags & WF_SYNC; + int sync = wake_flags & WF_SYNC; update_curr(cfs_rq); @@ -1582,7 +1582,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int flags */ if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle)) set_last_buddy(se); - if (sched_feat(NEXT_BUDDY) && !(flags & WF_FORK)) + if (sched_feat(NEXT_BUDDY) && !(wake_flags & WF_FORK)) set_next_buddy(pse); /* -- cgit v1.2.2 From eb24073bc1fe3e569a855cf38d529fb650c35524 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 16 Sep 2009 21:09:13 +0200 Subject: sched: Fix TASK_WAKING & loadaverage breakage Fix this: top - 21:54:00 up 2:59, 1 user, load average: 432512.33, 426421.74, 417432.74 Which happens because we now set TASK_WAKING before activate_task(). Cc: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 5049d959bb26..969dfaef2465 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2343,7 +2343,11 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, /* * In order to handle concurrent wakeups and release the rq->lock * we put the task in TASK_WAKING state. + * + * First fix up the nr_uninterruptible count: */ + if (task_contributes_to_load(p)) + rq->nr_uninterruptible--; p->state = TASK_WAKING; task_rq_unlock(rq, &flags); -- cgit v1.2.2 From ad4b78bbcbab66998b05d422ac6106b645796e54 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 16 Sep 2009 12:31:31 +0200 Subject: sched: Add new wakeup preemption mode: WAKEUP_RUNNING Create a new wakeup preemption mode, preempt towards tasks that run shorter on avg. It sets next buddy to be sure we actually run the task we preempted for. Test results: root@twins:~# while :; do :; done & [1] 6537 root@twins:~# while :; do :; done & [2] 6538 root@twins:~# while :; do :; done & [3] 6539 root@twins:~# while :; do :; done & [4] 6540 root@twins:/home/peter# ./latt -c4 sleep 4 Entries: 48 (clients=4) Averages: ------------------------------ Max 4750 usec Avg 497 usec Stdev 737 usec root@twins:/home/peter# echo WAKEUP_RUNNING > /debug/sched_features root@twins:/home/peter# ./latt -c4 sleep 4 Entries: 48 (clients=4) Averages: ------------------------------ Max 14 usec Avg 5 usec Stdev 3 usec Disabled by default - needs more testing. Signed-off-by: Peter Zijlstra Acked-by: Mike Galbraith Signed-off-by: Ingo Molnar LKML-Reference: --- kernel/sched.c | 17 ++++++++++------- kernel/sched_debug.c | 1 + kernel/sched_fair.c | 14 +++++++++++--- kernel/sched_features.h | 5 +++++ 4 files changed, 27 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 969dfaef2465..3bb4ea2ee6f0 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2458,6 +2458,7 @@ static void __sched_fork(struct task_struct *p) p->se.avg_overlap = 0; p->se.start_runtime = 0; p->se.avg_wakeup = sysctl_sched_wakeup_granularity; + p->se.avg_running = 0; #ifdef CONFIG_SCHEDSTATS p->se.wait_start = 0; @@ -5310,14 +5311,13 @@ static inline void schedule_debug(struct task_struct *prev) #endif } -static void put_prev_task(struct rq *rq, struct task_struct *prev) +static void put_prev_task(struct rq *rq, struct task_struct *p) { - if (prev->state == TASK_RUNNING) { - u64 runtime = prev->se.sum_exec_runtime; + u64 runtime = p->se.sum_exec_runtime - p->se.prev_sum_exec_runtime; - runtime -= prev->se.prev_sum_exec_runtime; - runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); + update_avg(&p->se.avg_running, runtime); + if (p->state == TASK_RUNNING) { /* * In order to avoid avg_overlap growing stale when we are * indeed overlapping and hence not getting put to sleep, grow @@ -5327,9 +5327,12 @@ static void put_prev_task(struct rq *rq, struct task_struct *prev) * correlates to the amount of cache footprint a task can * build up. */ - update_avg(&prev->se.avg_overlap, runtime); + runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); + update_avg(&p->se.avg_overlap, runtime); + } else { + update_avg(&p->se.avg_running, 0); } - prev->sched_class->put_prev_task(rq, prev); + p->sched_class->put_prev_task(rq, p); } /* diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 5ddbd0891267..efb84409bc43 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -395,6 +395,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) PN(se.sum_exec_runtime); PN(se.avg_overlap); PN(se.avg_wakeup); + PN(se.avg_running); nr_switches = p->nvcsw + p->nivcsw; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index c741cd9d38de..3e6f78c66876 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1605,9 +1605,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ return; } - if (!sched_feat(WAKEUP_PREEMPT)) - return; - if ((sched_feat(WAKEUP_SYNC) && sync) || (sched_feat(WAKEUP_OVERLAP) && (se->avg_overlap < sysctl_sched_migration_cost && @@ -1616,6 +1613,17 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ return; } + if (sched_feat(WAKEUP_RUNNING)) { + if (pse->avg_running < se->avg_running) { + set_next_buddy(pse); + resched_task(curr); + return; + } + } + + if (!sched_feat(WAKEUP_PREEMPT)) + return; + find_matching_se(&se, &pse); BUG_ON(!pse); diff --git a/kernel/sched_features.h b/kernel/sched_features.h index d5059fd761d9..0d94083582c7 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -53,6 +53,11 @@ SCHED_FEAT(WAKEUP_SYNC, 0) */ SCHED_FEAT(WAKEUP_OVERLAP, 0) +/* + * Wakeup preemption towards tasks that run short + */ +SCHED_FEAT(WAKEUP_RUNNING, 0) + /* * Use the SYNC wakeup hint, pipes and the likes use this to indicate * the remote end is likely to consume the data we just wrote, and -- cgit v1.2.2 From de69a80be32445b0a71e8e3b757e584d7beb90f7 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 17 Sep 2009 09:01:20 +0200 Subject: sched: Stop buddies from hogging the system Clear buddies more agressively. The (theoretical, haven't actually observed any of this) problem is that when we do not select either buddy in pick_next_entity() because they are too far ahead of the left-most task, we do not clear the buddies. This means that as soon as we service the left-most task, these same buddies will be tried again on the next schedule. Now if the left-most task was a pure hog, it wouldn't have done any wakeups and it wouldn't have set buddies of its own. That leads to the old buddies dominating, which would lead to bad latencies. Signed-off-by: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 3e6f78c66876..ffee827fa22f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -764,10 +764,10 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) static void __clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) { - if (cfs_rq->last == se) + if (!se || cfs_rq->last == se) cfs_rq->last = NULL; - if (cfs_rq->next == se) + if (!se || cfs_rq->next == se) cfs_rq->next = NULL; } @@ -1646,8 +1646,13 @@ static struct task_struct *pick_next_task_fair(struct rq *rq) /* * If se was a buddy, clear it so that it will have to earn * the favour again. + * + * If se was not a buddy, clear the buddies because neither + * was elegible to run, let them earn it again. + * + * IOW. unconditionally clear buddies. */ - __clear_buddies(cfs_rq, se); + __clear_buddies(cfs_rq, NULL); set_next_entity(cfs_rq, se); cfs_rq = group_cfs_rq(se); } while (cfs_rq); -- cgit v1.2.2 From 29cd8bae396583a2ee9a3340db8c5102acf9f6fd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 17 Sep 2009 09:01:14 +0200 Subject: sched: Fix SD_POWERSAVING_BALANCE|SD_PREFER_LOCAL vs SD_WAKE_AFFINE The SD_POWERSAVING_BALANCE|SD_PREFER_LOCAL code can break out of the domain iteration early, making us miss the SD_WAKE_AFFINE bits. Fix this by continuing iteration until there is no need for a larger domain. This also cleans up the cgroup stuff a bit, but not having two update_shares() invocations. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 42 +++++++++++++++++++++++++++--------------- 1 file changed, 27 insertions(+), 15 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ffee827fa22f..10d218ab69f2 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1333,11 +1333,12 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) */ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) { - struct sched_domain *tmp, *shares = NULL, *sd = NULL; + struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; int cpu = smp_processor_id(); int prev_cpu = task_cpu(p); int new_cpu = cpu; int want_affine = 0; + int want_sd = 1; int sync = wake_flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { @@ -1369,33 +1370,44 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag nr_running /= 2; if (nr_running < capacity) - break; + want_sd = 0; } if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { - if (sched_feat(LB_SHARES_UPDATE)) { - update_shares(tmp); - shares = tmp; - } - - if (wake_affine(tmp, p, sync)) { - new_cpu = cpu; - goto out; - } - + affine_sd = tmp; want_affine = 0; } + if (!want_sd && !want_affine) + break; + if (!(tmp->flags & sd_flag)) continue; - sd = tmp; + if (want_sd) + sd = tmp; + } + + if (sched_feat(LB_SHARES_UPDATE)) { + /* + * Pick the largest domain to update shares over + */ + tmp = sd; + if (affine_sd && (!tmp || + cpumask_weight(sched_domain_span(affine_sd)) > + cpumask_weight(sched_domain_span(sd)))) + tmp = affine_sd; + + if (tmp) + update_shares(tmp); } - if (sd && sd != shares && sched_feat(LB_SHARES_UPDATE)) - update_shares(sd); + if (affine_sd && wake_affine(affine_sd, p, sync)) { + new_cpu = cpu; + goto out; + } while (sd) { int load_idx = sd->forkexec_idx; -- cgit v1.2.2 From b375a11a239e9e1cac40c7f3ff28b343d9f7ac51 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 17 Sep 2009 00:05:58 -0400 Subject: tracing: switch function prints from %pf to %ps For direct function pointers (like what mcount provides) PowerPC64 requires the use of %ps, otherwise nothing is printed. This patch converts all prints of functions retrieved through mcount to use the %ps format from the %pf. Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 6 +++--- kernel/trace/trace_functions.c | 2 +- kernel/trace/trace_functions_graph.c | 6 +++--- 3 files changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f7ab7fc162cc..cc615f84751b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1405,7 +1405,7 @@ static int t_hash_show(struct seq_file *m, void *v) if (rec->ops->print) return rec->ops->print(m, rec->ip, rec->ops, rec->data); - seq_printf(m, "%pf:%pf", (void *)rec->ip, (void *)rec->ops->func); + seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); if (rec->data) seq_printf(m, ":%p", rec->data); @@ -1515,7 +1515,7 @@ static int t_show(struct seq_file *m, void *v) if (!rec) return 0; - seq_printf(m, "%pf\n", (void *)rec->ip); + seq_printf(m, "%ps\n", (void *)rec->ip); return 0; } @@ -2456,7 +2456,7 @@ static int g_show(struct seq_file *m, void *v) return 0; } - seq_printf(m, "%pf\n", (void *)*ptr); + seq_printf(m, "%ps\n", (void *)*ptr); return 0; } diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 5b01b94518fc..b3f3776b0cd6 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -290,7 +290,7 @@ ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip, { long count = (long)data; - seq_printf(m, "%pf:", (void *)ip); + seq_printf(m, "%ps:", (void *)ip); if (ops == &traceon_probe_ops) seq_printf(m, "traceon"); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 61f166707a08..45e6c01b2e4d 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -124,7 +124,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, if (unlikely(current->ret_stack[index].fp != frame_pointer)) { ftrace_graph_stop(); WARN(1, "Bad frame pointer: expected %lx, received %lx\n" - " from func %pF return to %lx\n", + " from func %ps return to %lx\n", current->ret_stack[index].fp, frame_pointer, (void *)current->ret_stack[index].func, @@ -669,7 +669,7 @@ print_graph_entry_leaf(struct trace_iterator *iter, return TRACE_TYPE_PARTIAL_LINE; } - ret = trace_seq_printf(s, "%pf();\n", (void *)call->func); + ret = trace_seq_printf(s, "%ps();\n", (void *)call->func); if (!ret) return TRACE_TYPE_PARTIAL_LINE; @@ -712,7 +712,7 @@ print_graph_entry_nested(struct trace_iterator *iter, return TRACE_TYPE_PARTIAL_LINE; } - ret = trace_seq_printf(s, "%pf() {\n", (void *)call->func); + ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func); if (!ret) return TRACE_TYPE_PARTIAL_LINE; -- cgit v1.2.2 From 5dd4de587fd9c25cb32a7a0fe9feec3647509b6f Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 17 Sep 2009 17:38:32 +0800 Subject: softirq: add BLOCK_IOPOLL to softirq_to_name With BLOCK_IOPOLL_SOFTIRQ added, softirq_to_name[] and show_softirq_name() needs to be updated. Signed-off-by: Li Zefan LKML-Reference: <4AB20398.8070209@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/softirq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/softirq.c b/kernel/softirq.c index 7db25067cd2d..f8749e5216e0 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -57,7 +57,7 @@ static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp static DEFINE_PER_CPU(struct task_struct *, ksoftirqd); char *softirq_to_name[NR_SOFTIRQS] = { - "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", + "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL", "TASKLET", "SCHED", "HRTIMER", "RCU" }; -- cgit v1.2.2 From 850bc73ffcc99cddfb52bc23217c60810c508853 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 17 Sep 2009 18:47:11 +0200 Subject: perf_counter: Do not throttle single swcounter events We can have swcounter events that contribute more than a single count per event, when used with a non-zero period, those can generate multiple events, which is when we need throttling. However, swcounter that contribute only a single count per event can only come as fast as we can run code, hence don't throttle them. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 667ab25ad3d5..fe0d1adde804 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -3494,14 +3494,15 @@ static void perf_log_throttle(struct perf_counter *counter, int enable) * Generic counter overflow handling, sampling. */ -int perf_counter_overflow(struct perf_counter *counter, int nmi, - struct perf_sample_data *data) +static int __perf_counter_overflow(struct perf_counter *counter, int nmi, + int throttle, struct perf_sample_data *data) { int events = atomic_read(&counter->event_limit); - int throttle = counter->pmu->unthrottle != NULL; struct hw_perf_counter *hwc = &counter->hw; int ret = 0; + throttle = (throttle && counter->pmu->unthrottle != NULL); + if (!throttle) { hwc->interrupts++; } else { @@ -3554,6 +3555,12 @@ int perf_counter_overflow(struct perf_counter *counter, int nmi, return ret; } +int perf_counter_overflow(struct perf_counter *counter, int nmi, + struct perf_sample_data *data) +{ + return __perf_counter_overflow(counter, nmi, 1, data); +} + /* * Generic software counter infrastructure */ @@ -3592,6 +3599,7 @@ static void perf_swcounter_overflow(struct perf_counter *counter, int nmi, struct perf_sample_data *data) { struct hw_perf_counter *hwc = &counter->hw; + int throttle = 0; u64 overflow; data->period = counter->hw.last_period; @@ -3601,13 +3609,14 @@ static void perf_swcounter_overflow(struct perf_counter *counter, return; for (; overflow; overflow--) { - if (perf_counter_overflow(counter, nmi, data)) { + if (__perf_counter_overflow(counter, nmi, throttle, data)) { /* * We inhibit the overflow from happening when * hwc->interrupts == MAX_INTERRUPTS. */ break; } + throttle = 0; } } -- cgit v1.2.2 From 2667de81f3256c944b06abdf2c56c2f192fcb724 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 17 Sep 2009 19:01:10 +0200 Subject: perf_counter: Allow for a wakeup watermark Currently we wake the mmap() consumer once every PAGE_SIZE of data and/or once event wakeup_events when specified. For high speed sampling this results in too many wakeups wrt. the buffer size, hence change this. We move the default wakeup limit to 1/4-th the buffer size, and provide for means to manually specify this limit. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index fe0d1adde804..29b73b6e8146 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -2176,6 +2176,13 @@ static int perf_mmap_data_alloc(struct perf_counter *counter, int nr_pages) data->nr_pages = nr_pages; atomic_set(&data->lock, -1); + if (counter->attr.watermark) { + data->watermark = min_t(long, PAGE_SIZE * nr_pages, + counter->attr.wakeup_watermark); + } + if (!data->watermark) + data->watermark = max(PAGE_SIZE, PAGE_SIZE * nr_pages / 4); + rcu_assign_pointer(counter->data, data); return 0; @@ -2517,23 +2524,15 @@ struct perf_output_handle { unsigned long flags; }; -static bool perf_output_space(struct perf_mmap_data *data, - unsigned int offset, unsigned int head) +static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail, + unsigned long offset, unsigned long head) { - unsigned long tail; unsigned long mask; if (!data->writable) return true; mask = (data->nr_pages << PAGE_SHIFT) - 1; - /* - * Userspace could choose to issue a mb() before updating the tail - * pointer. So that all reads will be completed before the write is - * issued. - */ - tail = ACCESS_ONCE(data->user_page->data_tail); - smp_rmb(); offset = (offset - tail) & mask; head = (head - tail) & mask; @@ -2679,7 +2678,7 @@ static int perf_output_begin(struct perf_output_handle *handle, { struct perf_counter *output_counter; struct perf_mmap_data *data; - unsigned int offset, head; + unsigned long tail, offset, head; int have_lost; struct { struct perf_event_header header; @@ -2717,16 +2716,23 @@ static int perf_output_begin(struct perf_output_handle *handle, perf_output_lock(handle); do { + /* + * Userspace could choose to issue a mb() before updating the + * tail pointer. So that all reads will be completed before the + * write is issued. + */ + tail = ACCESS_ONCE(data->user_page->data_tail); + smp_rmb(); offset = head = atomic_long_read(&data->head); head += size; - if (unlikely(!perf_output_space(data, offset, head))) + if (unlikely(!perf_output_space(data, tail, offset, head))) goto fail; } while (atomic_long_cmpxchg(&data->head, offset, head) != offset); handle->offset = offset; handle->head = head; - if ((offset >> PAGE_SHIFT) != (head >> PAGE_SHIFT)) + if (head - tail > data->watermark) atomic_set(&data->wakeup, 1); if (have_lost) { -- cgit v1.2.2 From de078d875cc7fc709f7818f26d38389c04369826 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 8 Sep 2009 15:54:36 -0700 Subject: rcu: Need to update rnp->gpnum if preemptable RCU is to be reliable Without this patch, tasks preempted in RCU read-side critical sections can fail to block the grace period, given that rnp->gpnum is used to determine which rnp->blocked_tasks[] element the preempted task is enqueued on. Before the patch, rnp->gpnum is always zero, so preempted tasks are always enqueued on rnp->blocked_tasks[0], which is correct only when the current CPU has not checked into the current grace period and the grace-period number is even, or, similarly, if the current CPU -has- checked into the current grace period and the grace-period number is odd. Signed-off-by: Paul E. McKenney Acked-by: Steven Rostedt Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org LKML-Reference: <12524504771622-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 6b11b07cfe7f..c634a92d1217 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -632,6 +632,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) /* Special-case the common single-level case. */ if (NUM_RCU_NODES == 1) { rnp->qsmask = rnp->qsmaskinit; + rnp->gpnum = rsp->gpnum; rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */ spin_unlock_irqrestore(&rnp->lock, flags); return; @@ -657,8 +658,10 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) */ rnp_end = rsp->level[NUM_RCU_LVLS - 1]; - for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) + for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) { rnp_cur->qsmask = rnp_cur->qsmaskinit; + rnp->gpnum = rsp->gpnum; + } /* * Now set up the leaf nodes. Here we must be careful. First, @@ -679,6 +682,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) for (; rnp_cur < rnp_end; rnp_cur++) { spin_lock(&rnp_cur->lock); /* irqs already disabled. */ rnp_cur->qsmask = rnp_cur->qsmaskinit; + rnp->gpnum = rsp->gpnum; spin_unlock(&rnp_cur->lock); /* irqs already disabled. */ } -- cgit v1.2.2 From b835db1f9cadaf008750a32664e35a207782c95e Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 8 Sep 2009 15:54:37 -0700 Subject: rcu: Initialize multi-level RCU grace periods holding locks Prior implementations initialized the root and any internal nodes without holding locks, then initialized the leaves holding locks. This is a false economy, as the leaf nodes will usually greatly outnumber the root and internal nodes. Acquiring locks on all nodes is conceptually much simpler as well. Signed-off-by: Paul E. McKenney Acked-by: Steven Rostedt Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org LKML-Reference: <12524504773190-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 41 ++++++++++++----------------------------- 1 file changed, 12 insertions(+), 29 deletions(-) (limited to 'kernel') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index c634a92d1217..da301e2fd84f 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -645,41 +645,24 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) spin_lock(&rsp->onofflock); /* irqs already disabled. */ /* - * Set the quiescent-state-needed bits in all the non-leaf RCU - * nodes for all currently online CPUs. This operation relies - * on the layout of the hierarchy within the rsp->node[] array. - * Note that other CPUs will access only the leaves of the - * hierarchy, which still indicate that no grace period is in - * progress. In addition, we have excluded CPU-hotplug operations. - * - * We therefore do not need to hold any locks. Any required - * memory barriers will be supplied by the locks guarding the - * leaf rcu_nodes in the hierarchy. - */ - - rnp_end = rsp->level[NUM_RCU_LVLS - 1]; - for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) { - rnp_cur->qsmask = rnp_cur->qsmaskinit; - rnp->gpnum = rsp->gpnum; - } - - /* - * Now set up the leaf nodes. Here we must be careful. First, - * we need to hold the lock in order to exclude other CPUs, which - * might be contending for the leaf nodes' locks. Second, as - * soon as we initialize a given leaf node, its CPUs might run - * up the rest of the hierarchy. We must therefore acquire locks - * for each node that we touch during this stage. (But we still - * are excluding CPU-hotplug operations.) + * Set the quiescent-state-needed bits in all the rcu_node + * structures for all currently online CPUs in breadth-first + * order, starting from the root rcu_node structure. This + * operation relies on the layout of the hierarchy within the + * rsp->node[] array. Note that other CPUs will access only + * the leaves of the hierarchy, which still indicate that no + * grace period is in progress, at least until the corresponding + * leaf node has been initialized. In addition, we have excluded + * CPU-hotplug operations. * * Note that the grace period cannot complete until we finish * the initialization process, as there will be at least one * qsmask bit set in the root node until that time, namely the - * one corresponding to this CPU. + * one corresponding to this CPU, due to the fact that we have + * irqs disabled. */ rnp_end = &rsp->node[NUM_RCU_NODES]; - rnp_cur = rsp->level[NUM_RCU_LVLS - 1]; - for (; rnp_cur < rnp_end; rnp_cur++) { + for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) { spin_lock(&rnp_cur->lock); /* irqs already disabled. */ rnp_cur->qsmask = rnp_cur->qsmaskinit; rnp->gpnum = rsp->gpnum; -- cgit v1.2.2 From b8d57a76d9f92aa63b4f12990da5697b17000b0c Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Tue, 8 Sep 2009 15:54:35 -0700 Subject: rcutorture: Occasionally delay readers enough to make RCU force_quiescent_state rcutorture already delays readers, but never for long enough to make RCU force a quiescent state. Add an occasional delay of 50ms. Signed-off-by: Josh Triplett Signed-off-by: Paul E. McKenney Acked-by: Steven Rostedt Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org LKML-Reference: <12524504772607-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutorture.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index b33db539a8ad..328a8257c885 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -281,14 +281,17 @@ static int rcu_torture_read_lock(void) __acquires(RCU) static void rcu_read_delay(struct rcu_random_state *rrsp) { - long delay; - const long longdelay = 200; + const unsigned long shortdelay_us = 200; + const unsigned long longdelay_ms = 50; - /* We want there to be long-running readers, but not all the time. */ + /* We want a short delay sometimes to make a reader delay the grace + * period, and we want a long delay occasionally to trigger + * force_quiescent_state. */ - delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay); - if (!delay) - udelay(longdelay); + if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) + mdelay(longdelay_ms); + if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) + udelay(shortdelay_us); } static void rcu_torture_read_unlock(int idx) __releases(RCU) -- cgit v1.2.2 From b0e165c035b13e1074fa0b555318bd9cb7102558 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 13 Sep 2009 09:15:09 -0700 Subject: rcu: Add debug checks to TREE_PREEMPT_RCU for premature grace periods Check to make sure that there are no blocked tasks for the previous grace period while initializing for the next grace period, verify that rcu_preempt_qs() is given the correct CPU number and is never called for an offline CPU. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <12528585111986-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 2 ++ kernel/rcutree_plugin.h | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+) (limited to 'kernel') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index da301e2fd84f..e9a4ae94647f 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -632,6 +632,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) /* Special-case the common single-level case. */ if (NUM_RCU_NODES == 1) { rnp->qsmask = rnp->qsmaskinit; + rcu_preempt_check_blocked_tasks(rnp); rnp->gpnum = rsp->gpnum; rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */ spin_unlock_irqrestore(&rnp->lock, flags); @@ -665,6 +666,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) { spin_lock(&rnp_cur->lock); /* irqs already disabled. */ rnp_cur->qsmask = rnp_cur->qsmaskinit; + rcu_preempt_check_blocked_tasks(rnp); rnp->gpnum = rsp->gpnum; spin_unlock(&rnp_cur->lock); /* irqs already disabled. */ } diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 47789369ea59..b8e4b0384f00 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -86,6 +86,7 @@ static void rcu_preempt_qs(int cpu) if (t->rcu_read_lock_nesting && (t->rcu_read_unlock_special & RCU_READ_UNLOCK_BLOCKED) == 0) { + WARN_ON_ONCE(cpu != smp_processor_id()); /* Possibly blocking in an RCU read-side critical section. */ rdp = rcu_preempt_state.rda[cpu]; @@ -103,7 +104,11 @@ static void rcu_preempt_qs(int cpu) * state for the current grace period), then as long * as that task remains queued, the current grace period * cannot end. + * + * But first, note that the current CPU must still be + * on line! */ + WARN_ON_ONCE((rdp->grpmask & rnp->qsmaskinit) == 0); phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1); list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]); smp_mb(); /* Ensure later ctxt swtch seen after above. */ @@ -258,6 +263,18 @@ static void rcu_print_task_stall(struct rcu_node *rnp) #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ +/* + * Check that the list of blocked tasks for the newly completed grace + * period is in fact empty. It is a serious bug to complete a grace + * period that still has RCU readers blocked! This function must be + * invoked -before- updating this rnp's ->gpnum, and the rnp's ->lock + * must be held by the caller. + */ +static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) +{ + WARN_ON_ONCE(!list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])); +} + /* * Check for preempted RCU readers for the specified rcu_node structure. * If the caller needs a reliable answer, it must hold the rcu_node's @@ -450,6 +467,14 @@ static void rcu_print_task_stall(struct rcu_node *rnp) #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ +/* + * Because there is no preemptable RCU, there can be no readers blocked, + * so there is no need to check for blocked tasks. + */ +static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) +{ +} + /* * Because preemptable RCU does not exist, there are never any preempted * RCU readers. -- cgit v1.2.2 From c3422bea5f09b0e85704f51f2b01271630b8940b Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 13 Sep 2009 09:15:10 -0700 Subject: rcu: Simplify rcu_read_unlock_special() quiescent-state accounting The earlier approach required two scheduling-clock ticks to note an preemptable-RCU quiescent state in the situation in which the scheduling-clock interrupt is unlucky enough to always interrupt an RCU read-side critical section. With this change, the quiescent state is instead noted by the outermost rcu_read_unlock() immediately following the first scheduling-clock tick, or, alternatively, by the first subsequent context switch. Therefore, this change also speeds up grace periods. Suggested-by: Josh Triplett Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <12528585111945-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 15 ++++++-------- kernel/rcutree_plugin.h | 54 ++++++++++++++++++++++++------------------------- 2 files changed, 32 insertions(+), 37 deletions(-) (limited to 'kernel') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index e9a4ae94647f..6c99553e9f15 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -107,27 +107,23 @@ static void __cpuinit rcu_init_percpu_data(int cpu, struct rcu_state *rsp, */ void rcu_sched_qs(int cpu) { - unsigned long flags; struct rcu_data *rdp; - local_irq_save(flags); rdp = &per_cpu(rcu_sched_data, cpu); - rdp->passed_quiesc = 1; rdp->passed_quiesc_completed = rdp->completed; - rcu_preempt_qs(cpu); - local_irq_restore(flags); + barrier(); + rdp->passed_quiesc = 1; + rcu_preempt_note_context_switch(cpu); } void rcu_bh_qs(int cpu) { - unsigned long flags; struct rcu_data *rdp; - local_irq_save(flags); rdp = &per_cpu(rcu_bh_data, cpu); - rdp->passed_quiesc = 1; rdp->passed_quiesc_completed = rdp->completed; - local_irq_restore(flags); + barrier(); + rdp->passed_quiesc = 1; } #ifdef CONFIG_NO_HZ @@ -615,6 +611,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) /* Advance to a new grace period and initialize state. */ rsp->gpnum++; + WARN_ON_ONCE(rsp->signaled == RCU_GP_INIT); rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */ rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS; record_gp_stall_check_time(rsp); diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index b8e4b0384f00..c9616e48379b 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -64,34 +64,42 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed); * not in a quiescent state. There might be any number of tasks blocked * while in an RCU read-side critical section. */ -static void rcu_preempt_qs_record(int cpu) +static void rcu_preempt_qs(int cpu) { struct rcu_data *rdp = &per_cpu(rcu_preempt_data, cpu); - rdp->passed_quiesc = 1; rdp->passed_quiesc_completed = rdp->completed; + barrier(); + rdp->passed_quiesc = 1; } /* - * We have entered the scheduler or are between softirqs in ksoftirqd. - * If we are in an RCU read-side critical section, we need to reflect - * that in the state of the rcu_node structure corresponding to this CPU. - * Caller must disable hardirqs. + * We have entered the scheduler, and the current task might soon be + * context-switched away from. If this task is in an RCU read-side + * critical section, we will no longer be able to rely on the CPU to + * record that fact, so we enqueue the task on the appropriate entry + * of the blocked_tasks[] array. The task will dequeue itself when + * it exits the outermost enclosing RCU read-side critical section. + * Therefore, the current grace period cannot be permitted to complete + * until the blocked_tasks[] entry indexed by the low-order bit of + * rnp->gpnum empties. + * + * Caller must disable preemption. */ -static void rcu_preempt_qs(int cpu) +static void rcu_preempt_note_context_switch(int cpu) { struct task_struct *t = current; + unsigned long flags; int phase; struct rcu_data *rdp; struct rcu_node *rnp; if (t->rcu_read_lock_nesting && (t->rcu_read_unlock_special & RCU_READ_UNLOCK_BLOCKED) == 0) { - WARN_ON_ONCE(cpu != smp_processor_id()); /* Possibly blocking in an RCU read-side critical section. */ rdp = rcu_preempt_state.rda[cpu]; rnp = rdp->mynode; - spin_lock(&rnp->lock); + spin_lock_irqsave(&rnp->lock, flags); t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED; t->rcu_blocked_node = rnp; @@ -112,7 +120,7 @@ static void rcu_preempt_qs(int cpu) phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1); list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]); smp_mb(); /* Ensure later ctxt swtch seen after above. */ - spin_unlock(&rnp->lock); + spin_unlock_irqrestore(&rnp->lock, flags); } /* @@ -124,9 +132,8 @@ static void rcu_preempt_qs(int cpu) * grace period, then the fact that the task has been enqueued * means that we continue to block the current grace period. */ - rcu_preempt_qs_record(cpu); - t->rcu_read_unlock_special &= ~(RCU_READ_UNLOCK_NEED_QS | - RCU_READ_UNLOCK_GOT_QS); + rcu_preempt_qs(cpu); + t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; } /* @@ -162,7 +169,7 @@ static void rcu_read_unlock_special(struct task_struct *t) special = t->rcu_read_unlock_special; if (special & RCU_READ_UNLOCK_NEED_QS) { t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; - t->rcu_read_unlock_special |= RCU_READ_UNLOCK_GOT_QS; + rcu_preempt_qs(smp_processor_id()); } /* Hardware IRQ handlers cannot block. */ @@ -199,9 +206,7 @@ static void rcu_read_unlock_special(struct task_struct *t) */ if (!empty && rnp->qsmask == 0 && list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) { - t->rcu_read_unlock_special &= - ~(RCU_READ_UNLOCK_NEED_QS | - RCU_READ_UNLOCK_GOT_QS); + t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; if (rnp->parent == NULL) { /* Only one rcu_node in the tree. */ cpu_quiet_msk_finish(&rcu_preempt_state, flags); @@ -352,19 +357,12 @@ static void rcu_preempt_check_callbacks(int cpu) struct task_struct *t = current; if (t->rcu_read_lock_nesting == 0) { - t->rcu_read_unlock_special &= - ~(RCU_READ_UNLOCK_NEED_QS | RCU_READ_UNLOCK_GOT_QS); - rcu_preempt_qs_record(cpu); + t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; + rcu_preempt_qs(cpu); return; } if (per_cpu(rcu_preempt_data, cpu).qs_pending) { - if (t->rcu_read_unlock_special & RCU_READ_UNLOCK_GOT_QS) { - rcu_preempt_qs_record(cpu); - t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_GOT_QS; - } else if (!(t->rcu_read_unlock_special & - RCU_READ_UNLOCK_NEED_QS)) { - t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS; - } + t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS; } } @@ -451,7 +449,7 @@ EXPORT_SYMBOL_GPL(rcu_batches_completed); * Because preemptable RCU does not exist, we never have to check for * CPUs being in quiescent states. */ -static void rcu_preempt_qs(int cpu) +static void rcu_preempt_note_context_switch(int cpu) { } -- cgit v1.2.2 From 16e3081191837a6a04733de5cd5d1d1b303140d4 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 13 Sep 2009 09:15:11 -0700 Subject: rcu: Fix synchronize_rcu() for TREE_PREEMPT_RCU The redirection of synchronize_sched() to synchronize_rcu() was appropriate for TREE_RCU, but not for TREE_PREEMPT_RCU. Fix this by creating an underlying synchronize_sched(). TREE_RCU then redirects synchronize_rcu() to synchronize_sched(), while TREE_PREEMPT_RCU has its own version of synchronize_rcu(). Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <12528585111916-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcupdate.c | 44 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 43 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index bd5d5c8e5140..28d2f24e7871 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -74,6 +74,8 @@ void wakeme_after_rcu(struct rcu_head *head) complete(&rcu->completion); } +#ifdef CONFIG_TREE_PREEMPT_RCU + /** * synchronize_rcu - wait until a grace period has elapsed. * @@ -87,7 +89,7 @@ void synchronize_rcu(void) { struct rcu_synchronize rcu; - if (rcu_blocking_is_gp()) + if (!rcu_scheduler_active) return; init_completion(&rcu.completion); @@ -98,6 +100,46 @@ void synchronize_rcu(void) } EXPORT_SYMBOL_GPL(synchronize_rcu); +#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ + +/** + * synchronize_sched - wait until an rcu-sched grace period has elapsed. + * + * Control will return to the caller some time after a full rcu-sched + * grace period has elapsed, in other words after all currently executing + * rcu-sched read-side critical sections have completed. These read-side + * critical sections are delimited by rcu_read_lock_sched() and + * rcu_read_unlock_sched(), and may be nested. Note that preempt_disable(), + * local_irq_disable(), and so on may be used in place of + * rcu_read_lock_sched(). + * + * This means that all preempt_disable code sequences, including NMI and + * hardware-interrupt handlers, in progress on entry will have completed + * before this primitive returns. However, this does not guarantee that + * softirq handlers will have completed, since in some kernels, these + * handlers can run in process context, and can block. + * + * This primitive provides the guarantees made by the (now removed) + * synchronize_kernel() API. In contrast, synchronize_rcu() only + * guarantees that rcu_read_lock() sections will have completed. + * In "classic RCU", these two guarantees happen to be one and + * the same, but can differ in realtime RCU implementations. + */ +void synchronize_sched(void) +{ + struct rcu_synchronize rcu; + + if (rcu_blocking_is_gp()) + return; + + init_completion(&rcu.completion); + /* Will wake me after RCU finished. */ + call_rcu_sched(&rcu.head, wakeme_after_rcu); + /* Wait for it. */ + wait_for_completion(&rcu.completion); +} +EXPORT_SYMBOL_GPL(synchronize_sched); + /** * synchronize_rcu_bh - wait until an rcu_bh grace period has elapsed. * -- cgit v1.2.2 From e5e25cf47b0bdd1f7e9b8bb6368ee48e16de0c87 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 18 Sep 2009 00:54:43 +0200 Subject: tracing: Factorize the events profile accounting Factorize the events enabling accounting in a common tracing core helper. This reduces the size of the profile_enable() and profile_disable() callbacks for each trace events. Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Acked-by: Li Zefan Cc: Peter Zijlstra Cc: Jason Baron Cc: Masami Hiramatsu Cc: Ingo Molnar --- kernel/trace/trace_event_profile.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index 55a25c933d15..df4a74efd50c 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -8,6 +8,14 @@ #include #include "trace.h" +static int ftrace_profile_enable_event(struct ftrace_event_call *event) +{ + if (atomic_inc_return(&event->profile_count)) + return 0; + + return event->profile_enable(); +} + int ftrace_profile_enable(int event_id) { struct ftrace_event_call *event; @@ -17,7 +25,7 @@ int ftrace_profile_enable(int event_id) list_for_each_entry(event, &ftrace_events, list) { if (event->id == event_id && event->profile_enable && try_module_get(event->mod)) { - ret = event->profile_enable(event); + ret = ftrace_profile_enable_event(event); break; } } @@ -26,6 +34,14 @@ int ftrace_profile_enable(int event_id) return ret; } +static void ftrace_profile_disable_event(struct ftrace_event_call *event) +{ + if (!atomic_add_negative(-1, &event->profile_count)) + return; + + event->profile_disable(); +} + void ftrace_profile_disable(int event_id) { struct ftrace_event_call *event; @@ -33,7 +49,7 @@ void ftrace_profile_disable(int event_id) mutex_lock(&event_mutex); list_for_each_entry(event, &ftrace_events, list) { if (event->id == event_id) { - event->profile_disable(event); + ftrace_profile_disable_event(event); module_put(event->mod); break; } -- cgit v1.2.2 From 20ab4425a77a1f34028cc6ce57053c22c184ba5f Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 18 Sep 2009 06:10:28 +0200 Subject: tracing: Allocate the ftrace event profile buffer dynamically Currently the trace event profile buffer is allocated in the stack. But this may be too much for the stack, as the events can have large statically defined field size and can also grow with dynamic arrays. Allocate two per cpu buffer for all profiled events. The first cpu buffer is used to host every non-nmi context traces. It is protected by disabling the interrupts while writing and committing the trace. The second buffer is reserved for nmi. So that there is no race between them and the first buffer. The whole write/commit section is rcu protected because we release these buffers while deactivating the last profiling trace event. v2: Move the buffers from trace_event to be global, as pointed by Steven Rostedt. v3: Fix the syscall events to handle the profiling buffer races by disabling interrupts, now that the buffers are globals. Suggested-by: Steven Rostedt Signed-off-by: Frederic Weisbecker Cc: Steven Rostedt Cc: Peter Zijlstra Cc: Li Zefan Cc: Jason Baron Cc: Masami Hiramatsu Cc: Ingo Molnar --- kernel/trace/trace_event_profile.c | 61 +++++++++++++++++++++++- kernel/trace/trace_syscalls.c | 97 ++++++++++++++++++++++++++++++-------- 2 files changed, 138 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index df4a74efd50c..3aaa77c3309b 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -8,12 +8,52 @@ #include #include "trace.h" +/* + * We can't use a size but a type in alloc_percpu() + * So let's create a dummy type that matches the desired size + */ +typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t; + +char *trace_profile_buf; +char *trace_profile_buf_nmi; + +/* Count the events in use (per event id, not per instance) */ +static int total_profile_count; + static int ftrace_profile_enable_event(struct ftrace_event_call *event) { + char *buf; + int ret = -ENOMEM; + if (atomic_inc_return(&event->profile_count)) return 0; - return event->profile_enable(); + if (!total_profile_count++) { + buf = (char *)alloc_percpu(profile_buf_t); + if (!buf) + goto fail_buf; + + rcu_assign_pointer(trace_profile_buf, buf); + + buf = (char *)alloc_percpu(profile_buf_t); + if (!buf) + goto fail_buf_nmi; + + rcu_assign_pointer(trace_profile_buf_nmi, buf); + } + + ret = event->profile_enable(); + if (!ret) + return 0; + + kfree(trace_profile_buf_nmi); +fail_buf_nmi: + kfree(trace_profile_buf); +fail_buf: + total_profile_count--; + atomic_dec(&event->profile_count); + + return ret; } int ftrace_profile_enable(int event_id) @@ -36,10 +76,29 @@ int ftrace_profile_enable(int event_id) static void ftrace_profile_disable_event(struct ftrace_event_call *event) { + char *buf, *nmi_buf; + if (!atomic_add_negative(-1, &event->profile_count)) return; event->profile_disable(); + + if (!--total_profile_count) { + buf = trace_profile_buf; + rcu_assign_pointer(trace_profile_buf, NULL); + + nmi_buf = trace_profile_buf_nmi; + rcu_assign_pointer(trace_profile_buf_nmi, NULL); + + /* + * Ensure every events in profiling have finished before + * releasing the buffers + */ + synchronize_sched(); + + free_percpu(buf); + free_percpu(nmi_buf); + } } void ftrace_profile_disable(int event_id) diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 8712ce3c6a0e..7a3550cf2597 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -384,10 +384,13 @@ static int sys_prof_refcount_exit; static void prof_syscall_enter(struct pt_regs *regs, long id) { - struct syscall_trace_enter *rec; struct syscall_metadata *sys_data; + struct syscall_trace_enter *rec; + unsigned long flags; + char *raw_data; int syscall_nr; int size; + int cpu; syscall_nr = syscall_get_nr(current, regs); if (!test_bit(syscall_nr, enabled_prof_enter_syscalls)) @@ -402,20 +405,38 @@ static void prof_syscall_enter(struct pt_regs *regs, long id) size = ALIGN(size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - do { - char raw_data[size]; + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "profile buffer not large enough")) + return; + + /* Protect the per cpu buffer, begin the rcu read side */ + local_irq_save(flags); - /* zero the dead bytes from align to not leak stack to user */ - *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + cpu = smp_processor_id(); + + if (in_nmi()) + raw_data = rcu_dereference(trace_profile_buf_nmi); + else + raw_data = rcu_dereference(trace_profile_buf); + + if (!raw_data) + goto end; - rec = (struct syscall_trace_enter *) raw_data; - tracing_generic_entry_update(&rec->ent, 0, 0); - rec->ent.type = sys_data->enter_id; - rec->nr = syscall_nr; - syscall_get_arguments(current, regs, 0, sys_data->nb_args, - (unsigned long *)&rec->args); - perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size); - } while(0); + raw_data = per_cpu_ptr(raw_data, cpu); + + /* zero the dead bytes from align to not leak stack to user */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + + rec = (struct syscall_trace_enter *) raw_data; + tracing_generic_entry_update(&rec->ent, 0, 0); + rec->ent.type = sys_data->enter_id; + rec->nr = syscall_nr; + syscall_get_arguments(current, regs, 0, sys_data->nb_args, + (unsigned long *)&rec->args); + perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size); + +end: + local_irq_restore(flags); } int reg_prof_syscall_enter(char *name) @@ -460,8 +481,12 @@ void unreg_prof_syscall_enter(char *name) static void prof_syscall_exit(struct pt_regs *regs, long ret) { struct syscall_metadata *sys_data; - struct syscall_trace_exit rec; + struct syscall_trace_exit *rec; + unsigned long flags; int syscall_nr; + char *raw_data; + int size; + int cpu; syscall_nr = syscall_get_nr(current, regs); if (!test_bit(syscall_nr, enabled_prof_exit_syscalls)) @@ -471,12 +496,46 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) if (!sys_data) return; - tracing_generic_entry_update(&rec.ent, 0, 0); - rec.ent.type = sys_data->exit_id; - rec.nr = syscall_nr; - rec.ret = syscall_get_return_value(current, regs); + /* We can probably do that at build time */ + size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); - perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec)); + /* + * Impossible, but be paranoid with the future + * How to put this check outside runtime? + */ + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "exit event has grown above profile buffer size")) + return; + + /* Protect the per cpu buffer, begin the rcu read side */ + local_irq_save(flags); + cpu = smp_processor_id(); + + if (in_nmi()) + raw_data = rcu_dereference(trace_profile_buf_nmi); + else + raw_data = rcu_dereference(trace_profile_buf); + + if (!raw_data) + goto end; + + raw_data = per_cpu_ptr(raw_data, cpu); + + /* zero the dead bytes from align to not leak stack to user */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + + rec = (struct syscall_trace_exit *)raw_data; + + tracing_generic_entry_update(&rec->ent, 0, 0); + rec->ent.type = sys_data->exit_id; + rec->nr = syscall_nr; + rec->ret = syscall_get_return_value(current, regs); + + perf_tpcounter_event(sys_data->exit_id, 0, 1, rec, size); + +end: + local_irq_restore(flags); } int reg_prof_syscall_exit(char *name) -- cgit v1.2.2 From a2e7a7eb2fea109891ffff90f947e8306080a2a3 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Fri, 18 Sep 2009 09:19:25 +0200 Subject: sched: Remove unneeded indentation in sched_fair.c::place_entity() Signed-off-by: Mike Galbraith Cc: Peter Zijlstra LKML-Reference: <1253258365.22787.33.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 41 +++++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 10d218ab69f2..29b35a7ec571 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -709,31 +709,28 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) if (initial && sched_feat(START_DEBIT)) vruntime += sched_vslice(cfs_rq, se); - if (!initial) { - /* sleeps upto a single latency don't count. */ - if (sched_feat(FAIR_SLEEPERS)) { - unsigned long thresh = sysctl_sched_latency; + /* sleeps up to a single latency don't count. */ + if (!initial && sched_feat(FAIR_SLEEPERS)) { + unsigned long thresh = sysctl_sched_latency; - /* - * Convert the sleeper threshold into virtual time. - * SCHED_IDLE is a special sub-class. We care about - * fairness only relative to other SCHED_IDLE tasks, - * all of which have the same weight. - */ - if (sched_feat(NORMALIZED_SLEEPER) && - (!entity_is_task(se) || - task_of(se)->policy != SCHED_IDLE)) - thresh = calc_delta_fair(thresh, se); + /* + * Convert the sleeper threshold into virtual time. + * SCHED_IDLE is a special sub-class. We care about + * fairness only relative to other SCHED_IDLE tasks, + * all of which have the same weight. + */ + if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) || + task_of(se)->policy != SCHED_IDLE)) + thresh = calc_delta_fair(thresh, se); - /* - * Halve their sleep time's effect, to allow - * for a gentler effect of sleepers: - */ - if (sched_feat(GENTLE_FAIR_SLEEPERS)) - thresh >>= 1; + /* + * Halve their sleep time's effect, to allow + * for a gentler effect of sleepers: + */ + if (sched_feat(GENTLE_FAIR_SLEEPERS)) + thresh >>= 1; - vruntime -= thresh; - } + vruntime -= thresh; } /* ensure we never gain time by being placed backwards. */ -- cgit v1.2.2 From 6952b61de9984073289859073e8195ad0bee8fd5 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Fri, 18 Sep 2009 23:55:55 +0400 Subject: headers: taskstats_kern.h trim Remove net/genetlink.h inclusion, now sched.c won't be recompiled because of some networking changes. Signed-off-by: Alexey Dobriyan Signed-off-by: Linus Torvalds --- kernel/delayacct.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/delayacct.c b/kernel/delayacct.c index abb6e17505e2..ead9b610aa71 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -15,6 +15,7 @@ #include #include +#include #include #include #include -- cgit v1.2.2 From 5622f295b53fb60dbf9bed3e2c89d182490a8b7f Mon Sep 17 00:00:00 2001 From: Markus Metzger Date: Tue, 15 Sep 2009 13:00:23 +0200 Subject: x86, perf_counter, bts: Optimize BTS overflow handling Draining the BTS buffer on a buffer overflow interrupt takes too long resulting in a kernel lockup when tracing the kernel. Restructure perf_counter sampling into sample creation and sample output. Prepare a single reference sample for BTS sampling and update the from and to address fields when draining the BTS buffer. Drain the entire BTS buffer between a single perf_output_begin() / perf_output_end() pair. Signed-off-by: Markus Metzger Signed-off-by: Peter Zijlstra LKML-Reference: <20090915130023.A16204@sedona.ch.intel.com> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 312 ++++++++++++++++++++++++++------------------------ 1 file changed, 165 insertions(+), 147 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 29b73b6e8146..215845243a69 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -2512,18 +2512,6 @@ __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) /* * Output */ - -struct perf_output_handle { - struct perf_counter *counter; - struct perf_mmap_data *data; - unsigned long head; - unsigned long offset; - int nmi; - int sample; - int locked; - unsigned long flags; -}; - static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail, unsigned long offset, unsigned long head) { @@ -2633,8 +2621,8 @@ out: local_irq_restore(handle->flags); } -static void perf_output_copy(struct perf_output_handle *handle, - const void *buf, unsigned int len) +void perf_output_copy(struct perf_output_handle *handle, + const void *buf, unsigned int len) { unsigned int pages_mask; unsigned int offset; @@ -2669,12 +2657,9 @@ static void perf_output_copy(struct perf_output_handle *handle, WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0); } -#define perf_output_put(handle, x) \ - perf_output_copy((handle), &(x), sizeof(x)) - -static int perf_output_begin(struct perf_output_handle *handle, - struct perf_counter *counter, unsigned int size, - int nmi, int sample) +int perf_output_begin(struct perf_output_handle *handle, + struct perf_counter *counter, unsigned int size, + int nmi, int sample) { struct perf_counter *output_counter; struct perf_mmap_data *data; @@ -2756,7 +2741,7 @@ out: return -ENOSPC; } -static void perf_output_end(struct perf_output_handle *handle) +void perf_output_end(struct perf_output_handle *handle) { struct perf_counter *counter = handle->counter; struct perf_mmap_data *data = handle->data; @@ -2870,82 +2855,151 @@ static void perf_output_read(struct perf_output_handle *handle, perf_output_read_one(handle, counter); } -void perf_counter_output(struct perf_counter *counter, int nmi, - struct perf_sample_data *data) +void perf_output_sample(struct perf_output_handle *handle, + struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_counter *counter) +{ + u64 sample_type = data->type; + + perf_output_put(handle, *header); + + if (sample_type & PERF_SAMPLE_IP) + perf_output_put(handle, data->ip); + + if (sample_type & PERF_SAMPLE_TID) + perf_output_put(handle, data->tid_entry); + + if (sample_type & PERF_SAMPLE_TIME) + perf_output_put(handle, data->time); + + if (sample_type & PERF_SAMPLE_ADDR) + perf_output_put(handle, data->addr); + + if (sample_type & PERF_SAMPLE_ID) + perf_output_put(handle, data->id); + + if (sample_type & PERF_SAMPLE_STREAM_ID) + perf_output_put(handle, data->stream_id); + + if (sample_type & PERF_SAMPLE_CPU) + perf_output_put(handle, data->cpu_entry); + + if (sample_type & PERF_SAMPLE_PERIOD) + perf_output_put(handle, data->period); + + if (sample_type & PERF_SAMPLE_READ) + perf_output_read(handle, counter); + + if (sample_type & PERF_SAMPLE_CALLCHAIN) { + if (data->callchain) { + int size = 1; + + if (data->callchain) + size += data->callchain->nr; + + size *= sizeof(u64); + + perf_output_copy(handle, data->callchain, size); + } else { + u64 nr = 0; + perf_output_put(handle, nr); + } + } + + if (sample_type & PERF_SAMPLE_RAW) { + if (data->raw) { + perf_output_put(handle, data->raw->size); + perf_output_copy(handle, data->raw->data, + data->raw->size); + } else { + struct { + u32 size; + u32 data; + } raw = { + .size = sizeof(u32), + .data = 0, + }; + perf_output_put(handle, raw); + } + } +} + +void perf_prepare_sample(struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_counter *counter, + struct pt_regs *regs) { - int ret; u64 sample_type = counter->attr.sample_type; - struct perf_output_handle handle; - struct perf_event_header header; - u64 ip; - struct { - u32 pid, tid; - } tid_entry; - struct perf_callchain_entry *callchain = NULL; - int callchain_size = 0; - u64 time; - struct { - u32 cpu, reserved; - } cpu_entry; - header.type = PERF_EVENT_SAMPLE; - header.size = sizeof(header); + data->type = sample_type; - header.misc = 0; - header.misc |= perf_misc_flags(data->regs); + header->type = PERF_EVENT_SAMPLE; + header->size = sizeof(*header); + + header->misc = 0; + header->misc |= perf_misc_flags(regs); if (sample_type & PERF_SAMPLE_IP) { - ip = perf_instruction_pointer(data->regs); - header.size += sizeof(ip); + data->ip = perf_instruction_pointer(regs); + + header->size += sizeof(data->ip); } if (sample_type & PERF_SAMPLE_TID) { /* namespace issues */ - tid_entry.pid = perf_counter_pid(counter, current); - tid_entry.tid = perf_counter_tid(counter, current); + data->tid_entry.pid = perf_counter_pid(counter, current); + data->tid_entry.tid = perf_counter_tid(counter, current); - header.size += sizeof(tid_entry); + header->size += sizeof(data->tid_entry); } if (sample_type & PERF_SAMPLE_TIME) { /* * Maybe do better on x86 and provide cpu_clock_nmi() */ - time = sched_clock(); + data->time = sched_clock(); - header.size += sizeof(u64); + header->size += sizeof(data->time); } if (sample_type & PERF_SAMPLE_ADDR) - header.size += sizeof(u64); + header->size += sizeof(data->addr); - if (sample_type & PERF_SAMPLE_ID) - header.size += sizeof(u64); + if (sample_type & PERF_SAMPLE_ID) { + data->id = primary_counter_id(counter); - if (sample_type & PERF_SAMPLE_STREAM_ID) - header.size += sizeof(u64); + header->size += sizeof(data->id); + } + + if (sample_type & PERF_SAMPLE_STREAM_ID) { + data->stream_id = counter->id; + + header->size += sizeof(data->stream_id); + } if (sample_type & PERF_SAMPLE_CPU) { - header.size += sizeof(cpu_entry); + data->cpu_entry.cpu = raw_smp_processor_id(); + data->cpu_entry.reserved = 0; - cpu_entry.cpu = raw_smp_processor_id(); - cpu_entry.reserved = 0; + header->size += sizeof(data->cpu_entry); } if (sample_type & PERF_SAMPLE_PERIOD) - header.size += sizeof(u64); + header->size += sizeof(data->period); if (sample_type & PERF_SAMPLE_READ) - header.size += perf_counter_read_size(counter); + header->size += perf_counter_read_size(counter); if (sample_type & PERF_SAMPLE_CALLCHAIN) { - callchain = perf_callchain(data->regs); + int size = 1; - if (callchain) { - callchain_size = (1 + callchain->nr) * sizeof(u64); - header.size += callchain_size; - } else - header.size += sizeof(u64); + data->callchain = perf_callchain(regs); + + if (data->callchain) + size += data->callchain->nr; + + header->size += size * sizeof(u64); } if (sample_type & PERF_SAMPLE_RAW) { @@ -2957,69 +3011,23 @@ void perf_counter_output(struct perf_counter *counter, int nmi, size += sizeof(u32); WARN_ON_ONCE(size & (sizeof(u64)-1)); - header.size += size; - } - - ret = perf_output_begin(&handle, counter, header.size, nmi, 1); - if (ret) - return; - - perf_output_put(&handle, header); - - if (sample_type & PERF_SAMPLE_IP) - perf_output_put(&handle, ip); - - if (sample_type & PERF_SAMPLE_TID) - perf_output_put(&handle, tid_entry); - - if (sample_type & PERF_SAMPLE_TIME) - perf_output_put(&handle, time); - - if (sample_type & PERF_SAMPLE_ADDR) - perf_output_put(&handle, data->addr); - - if (sample_type & PERF_SAMPLE_ID) { - u64 id = primary_counter_id(counter); - - perf_output_put(&handle, id); + header->size += size; } +} - if (sample_type & PERF_SAMPLE_STREAM_ID) - perf_output_put(&handle, counter->id); - - if (sample_type & PERF_SAMPLE_CPU) - perf_output_put(&handle, cpu_entry); - - if (sample_type & PERF_SAMPLE_PERIOD) - perf_output_put(&handle, data->period); +static void perf_counter_output(struct perf_counter *counter, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_output_handle handle; + struct perf_event_header header; - if (sample_type & PERF_SAMPLE_READ) - perf_output_read(&handle, counter); + perf_prepare_sample(&header, data, counter, regs); - if (sample_type & PERF_SAMPLE_CALLCHAIN) { - if (callchain) - perf_output_copy(&handle, callchain, callchain_size); - else { - u64 nr = 0; - perf_output_put(&handle, nr); - } - } + if (perf_output_begin(&handle, counter, header.size, nmi, 1)) + return; - if (sample_type & PERF_SAMPLE_RAW) { - if (data->raw) { - perf_output_put(&handle, data->raw->size); - perf_output_copy(&handle, data->raw->data, data->raw->size); - } else { - struct { - u32 size; - u32 data; - } raw = { - .size = sizeof(u32), - .data = 0, - }; - perf_output_put(&handle, raw); - } - } + perf_output_sample(&handle, &header, data, counter); perf_output_end(&handle); } @@ -3501,7 +3509,8 @@ static void perf_log_throttle(struct perf_counter *counter, int enable) */ static int __perf_counter_overflow(struct perf_counter *counter, int nmi, - int throttle, struct perf_sample_data *data) + int throttle, struct perf_sample_data *data, + struct pt_regs *regs) { int events = atomic_read(&counter->event_limit); struct hw_perf_counter *hwc = &counter->hw; @@ -3557,14 +3566,15 @@ static int __perf_counter_overflow(struct perf_counter *counter, int nmi, perf_counter_disable(counter); } - perf_counter_output(counter, nmi, data); + perf_counter_output(counter, nmi, data, regs); return ret; } int perf_counter_overflow(struct perf_counter *counter, int nmi, - struct perf_sample_data *data) + struct perf_sample_data *data, + struct pt_regs *regs) { - return __perf_counter_overflow(counter, nmi, 1, data); + return __perf_counter_overflow(counter, nmi, 1, data, regs); } /* @@ -3602,7 +3612,8 @@ again: } static void perf_swcounter_overflow(struct perf_counter *counter, - int nmi, struct perf_sample_data *data) + int nmi, struct perf_sample_data *data, + struct pt_regs *regs) { struct hw_perf_counter *hwc = &counter->hw; int throttle = 0; @@ -3615,7 +3626,8 @@ static void perf_swcounter_overflow(struct perf_counter *counter, return; for (; overflow; overflow--) { - if (__perf_counter_overflow(counter, nmi, throttle, data)) { + if (__perf_counter_overflow(counter, nmi, throttle, + data, regs)) { /* * We inhibit the overflow from happening when * hwc->interrupts == MAX_INTERRUPTS. @@ -3634,7 +3646,8 @@ static void perf_swcounter_unthrottle(struct perf_counter *counter) } static void perf_swcounter_add(struct perf_counter *counter, u64 nr, - int nmi, struct perf_sample_data *data) + int nmi, struct perf_sample_data *data, + struct pt_regs *regs) { struct hw_perf_counter *hwc = &counter->hw; @@ -3643,11 +3656,11 @@ static void perf_swcounter_add(struct perf_counter *counter, u64 nr, if (!hwc->sample_period) return; - if (!data->regs) + if (!regs) return; if (!atomic64_add_negative(nr, &hwc->period_left)) - perf_swcounter_overflow(counter, nmi, data); + perf_swcounter_overflow(counter, nmi, data, regs); } static int perf_swcounter_is_counting(struct perf_counter *counter) @@ -3706,7 +3719,8 @@ static int perf_swcounter_match(struct perf_counter *counter, static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, enum perf_type_id type, u32 event, u64 nr, int nmi, - struct perf_sample_data *data) + struct perf_sample_data *data, + struct pt_regs *regs) { struct perf_counter *counter; @@ -3715,8 +3729,8 @@ static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, rcu_read_lock(); list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_swcounter_match(counter, type, event, data->regs)) - perf_swcounter_add(counter, nr, nmi, data); + if (perf_swcounter_match(counter, type, event, regs)) + perf_swcounter_add(counter, nr, nmi, data, regs); } rcu_read_unlock(); } @@ -3737,7 +3751,8 @@ static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx) static void do_perf_swcounter_event(enum perf_type_id type, u32 event, u64 nr, int nmi, - struct perf_sample_data *data) + struct perf_sample_data *data, + struct pt_regs *regs) { struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); int *recursion = perf_swcounter_recursion_context(cpuctx); @@ -3750,7 +3765,7 @@ static void do_perf_swcounter_event(enum perf_type_id type, u32 event, barrier(); perf_swcounter_ctx_event(&cpuctx->ctx, type, event, - nr, nmi, data); + nr, nmi, data, regs); rcu_read_lock(); /* * doesn't really matter which of the child contexts the @@ -3758,7 +3773,7 @@ static void do_perf_swcounter_event(enum perf_type_id type, u32 event, */ ctx = rcu_dereference(current->perf_counter_ctxp); if (ctx) - perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data); + perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data, regs); rcu_read_unlock(); barrier(); @@ -3772,11 +3787,11 @@ void __perf_swcounter_event(u32 event, u64 nr, int nmi, struct pt_regs *regs, u64 addr) { struct perf_sample_data data = { - .regs = regs, .addr = addr, }; - do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, &data); + do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, + &data, regs); } static void perf_swcounter_read(struct perf_counter *counter) @@ -3813,6 +3828,7 @@ static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer) { enum hrtimer_restart ret = HRTIMER_RESTART; struct perf_sample_data data; + struct pt_regs *regs; struct perf_counter *counter; u64 period; @@ -3820,17 +3836,17 @@ static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer) counter->pmu->read(counter); data.addr = 0; - data.regs = get_irq_regs(); + regs = get_irq_regs(); /* * In case we exclude kernel IPs or are somehow not in interrupt * context, provide the next best thing, the user IP. */ - if ((counter->attr.exclude_kernel || !data.regs) && + if ((counter->attr.exclude_kernel || !regs) && !counter->attr.exclude_user) - data.regs = task_pt_regs(current); + regs = task_pt_regs(current); - if (data.regs) { - if (perf_counter_overflow(counter, 0, &data)) + if (regs) { + if (perf_counter_overflow(counter, 0, &data, regs)) ret = HRTIMER_NORESTART; } @@ -3966,15 +3982,17 @@ void perf_tpcounter_event(int event_id, u64 addr, u64 count, void *record, }; struct perf_sample_data data = { - .regs = get_irq_regs(), .addr = addr, .raw = &raw, }; - if (!data.regs) - data.regs = task_pt_regs(current); + struct pt_regs *regs = get_irq_regs(); + + if (!regs) + regs = task_pt_regs(current); - do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, &data); + do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, + &data, regs); } EXPORT_SYMBOL_GPL(perf_tpcounter_event); -- cgit v1.2.2 From cf450a7355a116af793998c118a6bcf7f5a8367e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 18 Sep 2009 12:18:14 +0200 Subject: perf_counter: Fix up swcounter throttling /me dons the brown paper bag. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 215845243a69..6944bd55ec4e 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -3634,7 +3634,7 @@ static void perf_swcounter_overflow(struct perf_counter *counter, */ break; } - throttle = 0; + throttle = 1; } } -- cgit v1.2.2 From def0a9b2573e00ab0b486cb5382625203ab4c4a6 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 18 Sep 2009 20:14:01 +0200 Subject: sched_clock: Make it NMI safe Arjan complained about the suckyness of TSC on modern machines, and asked if we could do something about that for PERF_SAMPLE_TIME. Make cpu_clock() NMI safe by removing the spinlock and using cmpxchg. This also makes it smaller and more robust. Affects architectures that use HAVE_UNSTABLE_SCHED_CLOCK, i.e. IA64 and x86. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 9 ++-- kernel/sched_clock.c | 122 ++++++++++++++++++++++---------------------------- 2 files changed, 56 insertions(+), 75 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 6944bd55ec4e..06d233a06da5 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -2955,10 +2955,7 @@ void perf_prepare_sample(struct perf_event_header *header, } if (sample_type & PERF_SAMPLE_TIME) { - /* - * Maybe do better on x86 and provide cpu_clock_nmi() - */ - data->time = sched_clock(); + data->time = perf_clock(); header->size += sizeof(data->time); } @@ -3488,7 +3485,7 @@ static void perf_log_throttle(struct perf_counter *counter, int enable) .misc = 0, .size = sizeof(throttle_event), }, - .time = sched_clock(), + .time = perf_clock(), .id = primary_counter_id(counter), .stream_id = counter->id, }; @@ -3540,7 +3537,7 @@ static int __perf_counter_overflow(struct perf_counter *counter, int nmi, } if (counter->attr.freq) { - u64 now = sched_clock(); + u64 now = perf_clock(); s64 delta = now - hwc->freq_stamp; hwc->freq_stamp = now; diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c index e1d16c9a7680..ac2e1dc708bd 100644 --- a/kernel/sched_clock.c +++ b/kernel/sched_clock.c @@ -48,13 +48,6 @@ static __read_mostly int sched_clock_running; __read_mostly int sched_clock_stable; struct sched_clock_data { - /* - * Raw spinlock - this is a special case: this might be called - * from within instrumentation code so we dont want to do any - * instrumentation ourselves. - */ - raw_spinlock_t lock; - u64 tick_raw; u64 tick_gtod; u64 clock; @@ -80,7 +73,6 @@ void sched_clock_init(void) for_each_possible_cpu(cpu) { struct sched_clock_data *scd = cpu_sdc(cpu); - scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; scd->tick_raw = 0; scd->tick_gtod = ktime_now; scd->clock = ktime_now; @@ -109,14 +101,19 @@ static inline u64 wrap_max(u64 x, u64 y) * - filter out backward motion * - use the GTOD tick value to create a window to filter crazy TSC values */ -static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now) +static u64 sched_clock_local(struct sched_clock_data *scd) { - s64 delta = now - scd->tick_raw; - u64 clock, min_clock, max_clock; + u64 now, clock, old_clock, min_clock, max_clock; + s64 delta; +again: + now = sched_clock(); + delta = now - scd->tick_raw; if (unlikely(delta < 0)) delta = 0; + old_clock = scd->clock; + /* * scd->clock = clamp(scd->tick_gtod + delta, * max(scd->tick_gtod, scd->clock), @@ -124,84 +121,73 @@ static u64 __update_sched_clock(struct sched_clock_data *scd, u64 now) */ clock = scd->tick_gtod + delta; - min_clock = wrap_max(scd->tick_gtod, scd->clock); - max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC); + min_clock = wrap_max(scd->tick_gtod, old_clock); + max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC); clock = wrap_max(clock, min_clock); clock = wrap_min(clock, max_clock); - scd->clock = clock; + if (cmpxchg(&scd->clock, old_clock, clock) != old_clock) + goto again; - return scd->clock; + return clock; } -static void lock_double_clock(struct sched_clock_data *data1, - struct sched_clock_data *data2) +static u64 sched_clock_remote(struct sched_clock_data *scd) { - if (data1 < data2) { - __raw_spin_lock(&data1->lock); - __raw_spin_lock(&data2->lock); + struct sched_clock_data *my_scd = this_scd(); + u64 this_clock, remote_clock; + u64 *ptr, old_val, val; + + sched_clock_local(my_scd); +again: + this_clock = my_scd->clock; + remote_clock = scd->clock; + + /* + * Use the opportunity that we have both locks + * taken to couple the two clocks: we take the + * larger time as the latest time for both + * runqueues. (this creates monotonic movement) + */ + if (likely((s64)(remote_clock - this_clock) < 0)) { + ptr = &scd->clock; + old_val = remote_clock; + val = this_clock; } else { - __raw_spin_lock(&data2->lock); - __raw_spin_lock(&data1->lock); + /* + * Should be rare, but possible: + */ + ptr = &my_scd->clock; + old_val = this_clock; + val = remote_clock; } + + if (cmpxchg(ptr, old_val, val) != old_val) + goto again; + + return val; } u64 sched_clock_cpu(int cpu) { - u64 now, clock, this_clock, remote_clock; struct sched_clock_data *scd; + u64 clock; + + WARN_ON_ONCE(!irqs_disabled()); if (sched_clock_stable) return sched_clock(); - scd = cpu_sdc(cpu); - - /* - * Normally this is not called in NMI context - but if it is, - * trying to do any locking here is totally lethal. - */ - if (unlikely(in_nmi())) - return scd->clock; - if (unlikely(!sched_clock_running)) return 0ull; - WARN_ON_ONCE(!irqs_disabled()); - now = sched_clock(); - - if (cpu != raw_smp_processor_id()) { - struct sched_clock_data *my_scd = this_scd(); - - lock_double_clock(scd, my_scd); - - this_clock = __update_sched_clock(my_scd, now); - remote_clock = scd->clock; - - /* - * Use the opportunity that we have both locks - * taken to couple the two clocks: we take the - * larger time as the latest time for both - * runqueues. (this creates monotonic movement) - */ - if (likely((s64)(remote_clock - this_clock) < 0)) { - clock = this_clock; - scd->clock = clock; - } else { - /* - * Should be rare, but possible: - */ - clock = remote_clock; - my_scd->clock = remote_clock; - } - - __raw_spin_unlock(&my_scd->lock); - } else { - __raw_spin_lock(&scd->lock); - clock = __update_sched_clock(scd, now); - } + scd = cpu_sdc(cpu); - __raw_spin_unlock(&scd->lock); + if (cpu != smp_processor_id()) + clock = sched_clock_remote(scd); + else + clock = sched_clock_local(scd); return clock; } @@ -223,11 +209,9 @@ void sched_clock_tick(void) now_gtod = ktime_to_ns(ktime_get()); now = sched_clock(); - __raw_spin_lock(&scd->lock); scd->tick_raw = now; scd->tick_gtod = now_gtod; - __update_sched_clock(scd, now); - __raw_spin_unlock(&scd->lock); + sched_clock_local(scd); } /* -- cgit v1.2.2 From fc5377668c3d808e1d53c4aee152c836f55c3490 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 17 Sep 2009 19:35:28 +0200 Subject: tracing: Remove markers Now that the last users of markers have migrated to the event tracer we can kill off the (now orphan) support code. Signed-off-by: Christoph Hellwig Acked-by: Mathieu Desnoyers Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <20090917173527.GA1699@lst.de> Signed-off-by: Ingo Molnar --- kernel/Makefile | 1 - kernel/marker.c | 930 -------------------------------------------- kernel/module.c | 18 - kernel/trace/trace_printk.c | 1 - 4 files changed, 950 deletions(-) delete mode 100644 kernel/marker.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 3d9c7e27e3f9..7c9b0a585502 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -87,7 +87,6 @@ obj-$(CONFIG_RELAY) += relay.o obj-$(CONFIG_SYSCTL) += utsname_sysctl.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o -obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_FUNCTION_TRACER) += trace/ diff --git a/kernel/marker.c b/kernel/marker.c deleted file mode 100644 index ea54f2647868..000000000000 --- a/kernel/marker.c +++ /dev/null @@ -1,930 +0,0 @@ -/* - * Copyright (C) 2007 Mathieu Desnoyers - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - */ -#include -#include -#include -#include -#include -#include -#include -#include -#include - -extern struct marker __start___markers[]; -extern struct marker __stop___markers[]; - -/* Set to 1 to enable marker debug output */ -static const int marker_debug; - -/* - * markers_mutex nests inside module_mutex. Markers mutex protects the builtin - * and module markers and the hash table. - */ -static DEFINE_MUTEX(markers_mutex); - -/* - * Marker hash table, containing the active markers. - * Protected by module_mutex. - */ -#define MARKER_HASH_BITS 6 -#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) -static struct hlist_head marker_table[MARKER_TABLE_SIZE]; - -/* - * Note about RCU : - * It is used to make sure every handler has finished using its private data - * between two consecutive operation (add or remove) on a given marker. It is - * also used to delay the free of multiple probes array until a quiescent state - * is reached. - * marker entries modifications are protected by the markers_mutex. - */ -struct marker_entry { - struct hlist_node hlist; - char *format; - /* Probe wrapper */ - void (*call)(const struct marker *mdata, void *call_private, ...); - struct marker_probe_closure single; - struct marker_probe_closure *multi; - int refcount; /* Number of times armed. 0 if disarmed. */ - struct rcu_head rcu; - void *oldptr; - int rcu_pending; - unsigned char ptype:1; - unsigned char format_allocated:1; - char name[0]; /* Contains name'\0'format'\0' */ -}; - -/** - * __mark_empty_function - Empty probe callback - * @probe_private: probe private data - * @call_private: call site private data - * @fmt: format string - * @...: variable argument list - * - * Empty callback provided as a probe to the markers. By providing this to a - * disabled marker, we make sure the execution flow is always valid even - * though the function pointer change and the marker enabling are two distinct - * operations that modifies the execution flow of preemptible code. - */ -notrace void __mark_empty_function(void *probe_private, void *call_private, - const char *fmt, va_list *args) -{ -} -EXPORT_SYMBOL_GPL(__mark_empty_function); - -/* - * marker_probe_cb Callback that prepares the variable argument list for probes. - * @mdata: pointer of type struct marker - * @call_private: caller site private data - * @...: Variable argument list. - * - * Since we do not use "typical" pointer based RCU in the 1 argument case, we - * need to put a full smp_rmb() in this branch. This is why we do not use - * rcu_dereference() for the pointer read. - */ -notrace void marker_probe_cb(const struct marker *mdata, - void *call_private, ...) -{ - va_list args; - char ptype; - - /* - * rcu_read_lock_sched does two things : disabling preemption to make - * sure the teardown of the callbacks can be done correctly when they - * are in modules and they insure RCU read coherency. - */ - rcu_read_lock_sched_notrace(); - ptype = mdata->ptype; - if (likely(!ptype)) { - marker_probe_func *func; - /* Must read the ptype before ptr. They are not data dependant, - * so we put an explicit smp_rmb() here. */ - smp_rmb(); - func = mdata->single.func; - /* Must read the ptr before private data. They are not data - * dependant, so we put an explicit smp_rmb() here. */ - smp_rmb(); - va_start(args, call_private); - func(mdata->single.probe_private, call_private, mdata->format, - &args); - va_end(args); - } else { - struct marker_probe_closure *multi; - int i; - /* - * Read mdata->ptype before mdata->multi. - */ - smp_rmb(); - multi = mdata->multi; - /* - * multi points to an array, therefore accessing the array - * depends on reading multi. However, even in this case, - * we must insure that the pointer is read _before_ the array - * data. Same as rcu_dereference, but we need a full smp_rmb() - * in the fast path, so put the explicit barrier here. - */ - smp_read_barrier_depends(); - for (i = 0; multi[i].func; i++) { - va_start(args, call_private); - multi[i].func(multi[i].probe_private, call_private, - mdata->format, &args); - va_end(args); - } - } - rcu_read_unlock_sched_notrace(); -} -EXPORT_SYMBOL_GPL(marker_probe_cb); - -/* - * marker_probe_cb Callback that does not prepare the variable argument list. - * @mdata: pointer of type struct marker - * @call_private: caller site private data - * @...: Variable argument list. - * - * Should be connected to markers "MARK_NOARGS". - */ -static notrace void marker_probe_cb_noarg(const struct marker *mdata, - void *call_private, ...) -{ - va_list args; /* not initialized */ - char ptype; - - rcu_read_lock_sched_notrace(); - ptype = mdata->ptype; - if (likely(!ptype)) { - marker_probe_func *func; - /* Must read the ptype before ptr. They are not data dependant, - * so we put an explicit smp_rmb() here. */ - smp_rmb(); - func = mdata->single.func; - /* Must read the ptr before private data. They are not data - * dependant, so we put an explicit smp_rmb() here. */ - smp_rmb(); - func(mdata->single.probe_private, call_private, mdata->format, - &args); - } else { - struct marker_probe_closure *multi; - int i; - /* - * Read mdata->ptype before mdata->multi. - */ - smp_rmb(); - multi = mdata->multi; - /* - * multi points to an array, therefore accessing the array - * depends on reading multi. However, even in this case, - * we must insure that the pointer is read _before_ the array - * data. Same as rcu_dereference, but we need a full smp_rmb() - * in the fast path, so put the explicit barrier here. - */ - smp_read_barrier_depends(); - for (i = 0; multi[i].func; i++) - multi[i].func(multi[i].probe_private, call_private, - mdata->format, &args); - } - rcu_read_unlock_sched_notrace(); -} - -static void free_old_closure(struct rcu_head *head) -{ - struct marker_entry *entry = container_of(head, - struct marker_entry, rcu); - kfree(entry->oldptr); - /* Make sure we free the data before setting the pending flag to 0 */ - smp_wmb(); - entry->rcu_pending = 0; -} - -static void debug_print_probes(struct marker_entry *entry) -{ - int i; - - if (!marker_debug) - return; - - if (!entry->ptype) { - printk(KERN_DEBUG "Single probe : %p %p\n", - entry->single.func, - entry->single.probe_private); - } else { - for (i = 0; entry->multi[i].func; i++) - printk(KERN_DEBUG "Multi probe %d : %p %p\n", i, - entry->multi[i].func, - entry->multi[i].probe_private); - } -} - -static struct marker_probe_closure * -marker_entry_add_probe(struct marker_entry *entry, - marker_probe_func *probe, void *probe_private) -{ - int nr_probes = 0; - struct marker_probe_closure *old, *new; - - WARN_ON(!probe); - - debug_print_probes(entry); - old = entry->multi; - if (!entry->ptype) { - if (entry->single.func == probe && - entry->single.probe_private == probe_private) - return ERR_PTR(-EBUSY); - if (entry->single.func == __mark_empty_function) { - /* 0 -> 1 probes */ - entry->single.func = probe; - entry->single.probe_private = probe_private; - entry->refcount = 1; - entry->ptype = 0; - debug_print_probes(entry); - return NULL; - } else { - /* 1 -> 2 probes */ - nr_probes = 1; - old = NULL; - } - } else { - /* (N -> N+1), (N != 0, 1) probes */ - for (nr_probes = 0; old[nr_probes].func; nr_probes++) - if (old[nr_probes].func == probe - && old[nr_probes].probe_private - == probe_private) - return ERR_PTR(-EBUSY); - } - /* + 2 : one for new probe, one for NULL func */ - new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure), - GFP_KERNEL); - if (new == NULL) - return ERR_PTR(-ENOMEM); - if (!old) - new[0] = entry->single; - else - memcpy(new, old, - nr_probes * sizeof(struct marker_probe_closure)); - new[nr_probes].func = probe; - new[nr_probes].probe_private = probe_private; - entry->refcount = nr_probes + 1; - entry->multi = new; - entry->ptype = 1; - debug_print_probes(entry); - return old; -} - -static struct marker_probe_closure * -marker_entry_remove_probe(struct marker_entry *entry, - marker_probe_func *probe, void *probe_private) -{ - int nr_probes = 0, nr_del = 0, i; - struct marker_probe_closure *old, *new; - - old = entry->multi; - - debug_print_probes(entry); - if (!entry->ptype) { - /* 0 -> N is an error */ - WARN_ON(entry->single.func == __mark_empty_function); - /* 1 -> 0 probes */ - WARN_ON(probe && entry->single.func != probe); - WARN_ON(entry->single.probe_private != probe_private); - entry->single.func = __mark_empty_function; - entry->refcount = 0; - entry->ptype = 0; - debug_print_probes(entry); - return NULL; - } else { - /* (N -> M), (N > 1, M >= 0) probes */ - for (nr_probes = 0; old[nr_probes].func; nr_probes++) { - if ((!probe || old[nr_probes].func == probe) - && old[nr_probes].probe_private - == probe_private) - nr_del++; - } - } - - if (nr_probes - nr_del == 0) { - /* N -> 0, (N > 1) */ - entry->single.func = __mark_empty_function; - entry->refcount = 0; - entry->ptype = 0; - } else if (nr_probes - nr_del == 1) { - /* N -> 1, (N > 1) */ - for (i = 0; old[i].func; i++) - if ((probe && old[i].func != probe) || - old[i].probe_private != probe_private) - entry->single = old[i]; - entry->refcount = 1; - entry->ptype = 0; - } else { - int j = 0; - /* N -> M, (N > 1, M > 1) */ - /* + 1 for NULL */ - new = kzalloc((nr_probes - nr_del + 1) - * sizeof(struct marker_probe_closure), GFP_KERNEL); - if (new == NULL) - return ERR_PTR(-ENOMEM); - for (i = 0; old[i].func; i++) - if ((probe && old[i].func != probe) || - old[i].probe_private != probe_private) - new[j++] = old[i]; - entry->refcount = nr_probes - nr_del; - entry->ptype = 1; - entry->multi = new; - } - debug_print_probes(entry); - return old; -} - -/* - * Get marker if the marker is present in the marker hash table. - * Must be called with markers_mutex held. - * Returns NULL if not present. - */ -static struct marker_entry *get_marker(const char *name) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - u32 hash = jhash(name, strlen(name), 0); - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) - return e; - } - return NULL; -} - -/* - * Add the marker to the marker hash table. Must be called with markers_mutex - * held. - */ -static struct marker_entry *add_marker(const char *name, const char *format) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - size_t name_len = strlen(name) + 1; - size_t format_len = 0; - u32 hash = jhash(name, name_len-1, 0); - - if (format) - format_len = strlen(format) + 1; - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - printk(KERN_NOTICE - "Marker %s busy\n", name); - return ERR_PTR(-EBUSY); /* Already there */ - } - } - /* - * Using kmalloc here to allocate a variable length element. Could - * cause some memory fragmentation if overused. - */ - e = kmalloc(sizeof(struct marker_entry) + name_len + format_len, - GFP_KERNEL); - if (!e) - return ERR_PTR(-ENOMEM); - memcpy(&e->name[0], name, name_len); - if (format) { - e->format = &e->name[name_len]; - memcpy(e->format, format, format_len); - if (strcmp(e->format, MARK_NOARGS) == 0) - e->call = marker_probe_cb_noarg; - else - e->call = marker_probe_cb; - trace_mark(core_marker_format, "name %s format %s", - e->name, e->format); - } else { - e->format = NULL; - e->call = marker_probe_cb; - } - e->single.func = __mark_empty_function; - e->single.probe_private = NULL; - e->multi = NULL; - e->ptype = 0; - e->format_allocated = 0; - e->refcount = 0; - e->rcu_pending = 0; - hlist_add_head(&e->hlist, head); - return e; -} - -/* - * Remove the marker from the marker hash table. Must be called with mutex_lock - * held. - */ -static int remove_marker(const char *name) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - int found = 0; - size_t len = strlen(name) + 1; - u32 hash = jhash(name, len-1, 0); - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - found = 1; - break; - } - } - if (!found) - return -ENOENT; - if (e->single.func != __mark_empty_function) - return -EBUSY; - hlist_del(&e->hlist); - if (e->format_allocated) - kfree(e->format); - /* Make sure the call_rcu has been executed */ - if (e->rcu_pending) - rcu_barrier_sched(); - kfree(e); - return 0; -} - -/* - * Set the mark_entry format to the format found in the element. - */ -static int marker_set_format(struct marker_entry *entry, const char *format) -{ - entry->format = kstrdup(format, GFP_KERNEL); - if (!entry->format) - return -ENOMEM; - entry->format_allocated = 1; - - trace_mark(core_marker_format, "name %s format %s", - entry->name, entry->format); - return 0; -} - -/* - * Sets the probe callback corresponding to one marker. - */ -static int set_marker(struct marker_entry *entry, struct marker *elem, - int active) -{ - int ret = 0; - WARN_ON(strcmp(entry->name, elem->name) != 0); - - if (entry->format) { - if (strcmp(entry->format, elem->format) != 0) { - printk(KERN_NOTICE - "Format mismatch for probe %s " - "(%s), marker (%s)\n", - entry->name, - entry->format, - elem->format); - return -EPERM; - } - } else { - ret = marker_set_format(entry, elem->format); - if (ret) - return ret; - } - - /* - * probe_cb setup (statically known) is done here. It is - * asynchronous with the rest of execution, therefore we only - * pass from a "safe" callback (with argument) to an "unsafe" - * callback (does not set arguments). - */ - elem->call = entry->call; - /* - * Sanity check : - * We only update the single probe private data when the ptr is - * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) - */ - WARN_ON(elem->single.func != __mark_empty_function - && elem->single.probe_private != entry->single.probe_private - && !elem->ptype); - elem->single.probe_private = entry->single.probe_private; - /* - * Make sure the private data is valid when we update the - * single probe ptr. - */ - smp_wmb(); - elem->single.func = entry->single.func; - /* - * We also make sure that the new probe callbacks array is consistent - * before setting a pointer to it. - */ - rcu_assign_pointer(elem->multi, entry->multi); - /* - * Update the function or multi probe array pointer before setting the - * ptype. - */ - smp_wmb(); - elem->ptype = entry->ptype; - - if (elem->tp_name && (active ^ elem->state)) { - WARN_ON(!elem->tp_cb); - /* - * It is ok to directly call the probe registration because type - * checking has been done in the __trace_mark_tp() macro. - */ - - if (active) { - /* - * try_module_get should always succeed because we hold - * lock_module() to get the tp_cb address. - */ - ret = try_module_get(__module_text_address( - (unsigned long)elem->tp_cb)); - BUG_ON(!ret); - ret = tracepoint_probe_register_noupdate( - elem->tp_name, - elem->tp_cb); - } else { - ret = tracepoint_probe_unregister_noupdate( - elem->tp_name, - elem->tp_cb); - /* - * tracepoint_probe_update_all() must be called - * before the module containing tp_cb is unloaded. - */ - module_put(__module_text_address( - (unsigned long)elem->tp_cb)); - } - } - elem->state = active; - - return ret; -} - -/* - * Disable a marker and its probe callback. - * Note: only waiting an RCU period after setting elem->call to the empty - * function insures that the original callback is not used anymore. This insured - * by rcu_read_lock_sched around the call site. - */ -static void disable_marker(struct marker *elem) -{ - int ret; - - /* leave "call" as is. It is known statically. */ - if (elem->tp_name && elem->state) { - WARN_ON(!elem->tp_cb); - /* - * It is ok to directly call the probe registration because type - * checking has been done in the __trace_mark_tp() macro. - */ - ret = tracepoint_probe_unregister_noupdate(elem->tp_name, - elem->tp_cb); - WARN_ON(ret); - /* - * tracepoint_probe_update_all() must be called - * before the module containing tp_cb is unloaded. - */ - module_put(__module_text_address((unsigned long)elem->tp_cb)); - } - elem->state = 0; - elem->single.func = __mark_empty_function; - /* Update the function before setting the ptype */ - smp_wmb(); - elem->ptype = 0; /* single probe */ - /* - * Leave the private data and id there, because removal is racy and - * should be done only after an RCU period. These are never used until - * the next initialization anyway. - */ -} - -/** - * marker_update_probe_range - Update a probe range - * @begin: beginning of the range - * @end: end of the range - * - * Updates the probe callback corresponding to a range of markers. - */ -void marker_update_probe_range(struct marker *begin, - struct marker *end) -{ - struct marker *iter; - struct marker_entry *mark_entry; - - mutex_lock(&markers_mutex); - for (iter = begin; iter < end; iter++) { - mark_entry = get_marker(iter->name); - if (mark_entry) { - set_marker(mark_entry, iter, !!mark_entry->refcount); - /* - * ignore error, continue - */ - } else { - disable_marker(iter); - } - } - mutex_unlock(&markers_mutex); -} - -/* - * Update probes, removing the faulty probes. - * - * Internal callback only changed before the first probe is connected to it. - * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 - * transitions. All other transitions will leave the old private data valid. - * This makes the non-atomicity of the callback/private data updates valid. - * - * "special case" updates : - * 0 -> 1 callback - * 1 -> 0 callback - * 1 -> 2 callbacks - * 2 -> 1 callbacks - * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. - * Site effect : marker_set_format may delete the marker entry (creating a - * replacement). - */ -static void marker_update_probes(void) -{ - /* Core kernel markers */ - marker_update_probe_range(__start___markers, __stop___markers); - /* Markers in modules. */ - module_update_markers(); - tracepoint_probe_update_all(); -} - -/** - * marker_probe_register - Connect a probe to a marker - * @name: marker name - * @format: format string - * @probe: probe handler - * @probe_private: probe private data - * - * private data must be a valid allocated memory address, or NULL. - * Returns 0 if ok, error value on error. - * The probe address must at least be aligned on the architecture pointer size. - */ -int marker_probe_register(const char *name, const char *format, - marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - int ret = 0; - struct marker_probe_closure *old; - - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) { - entry = add_marker(name, format); - if (IS_ERR(entry)) - ret = PTR_ERR(entry); - } else if (format) { - if (!entry->format) - ret = marker_set_format(entry, format); - else if (strcmp(entry->format, format)) - ret = -EPERM; - } - if (ret) - goto end; - - /* - * If we detect that a call_rcu is pending for this marker, - * make sure it's executed now. - */ - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_add_probe(entry, probe, probe_private); - if (IS_ERR(old)) { - ret = PTR_ERR(old); - goto end; - } - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_register); - -/** - * marker_probe_unregister - Disconnect a probe from a marker - * @name: marker name - * @probe: probe function pointer - * @probe_private: probe private data - * - * Returns the private data given to marker_probe_register, or an ERR_PTR(). - * We do not need to call a synchronize_sched to make sure the probes have - * finished running before doing a module unload, because the module unload - * itself uses stop_machine(), which insures that every preempt disabled section - * have finished. - */ -int marker_probe_unregister(const char *name, - marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - struct marker_probe_closure *old; - int ret = -ENOENT; - - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_remove_probe(entry, probe, probe_private); - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); - remove_marker(name); /* Ignore busy error message */ - ret = 0; -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_unregister); - -static struct marker_entry * -get_marker_from_private_data(marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - unsigned int i; - struct hlist_head *head; - struct hlist_node *node; - - for (i = 0; i < MARKER_TABLE_SIZE; i++) { - head = &marker_table[i]; - hlist_for_each_entry(entry, node, head, hlist) { - if (!entry->ptype) { - if (entry->single.func == probe - && entry->single.probe_private - == probe_private) - return entry; - } else { - struct marker_probe_closure *closure; - closure = entry->multi; - for (i = 0; closure[i].func; i++) { - if (closure[i].func == probe && - closure[i].probe_private - == probe_private) - return entry; - } - } - } - } - return NULL; -} - -/** - * marker_probe_unregister_private_data - Disconnect a probe from a marker - * @probe: probe function - * @probe_private: probe private data - * - * Unregister a probe by providing the registered private data. - * Only removes the first marker found in hash table. - * Return 0 on success or error value. - * We do not need to call a synchronize_sched to make sure the probes have - * finished running before doing a module unload, because the module unload - * itself uses stop_machine(), which insures that every preempt disabled section - * have finished. - */ -int marker_probe_unregister_private_data(marker_probe_func *probe, - void *probe_private) -{ - struct marker_entry *entry; - int ret = 0; - struct marker_probe_closure *old; - - mutex_lock(&markers_mutex); - entry = get_marker_from_private_data(probe, probe_private); - if (!entry) { - ret = -ENOENT; - goto end; - } - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_remove_probe(entry, NULL, probe_private); - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker_from_private_data(probe, probe_private); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); - remove_marker(entry->name); /* Ignore busy error message */ -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); - -/** - * marker_get_private_data - Get a marker's probe private data - * @name: marker name - * @probe: probe to match - * @num: get the nth matching probe's private data - * - * Returns the nth private data pointer (starting from 0) matching, or an - * ERR_PTR. - * Returns the private data pointer, or an ERR_PTR. - * The private data pointer should _only_ be dereferenced if the caller is the - * owner of the data, or its content could vanish. This is mostly used to - * confirm that a caller is the owner of a registered probe. - */ -void *marker_get_private_data(const char *name, marker_probe_func *probe, - int num) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - size_t name_len = strlen(name) + 1; - u32 hash = jhash(name, name_len-1, 0); - int i; - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - if (!e->ptype) { - if (num == 0 && e->single.func == probe) - return e->single.probe_private; - } else { - struct marker_probe_closure *closure; - int match = 0; - closure = e->multi; - for (i = 0; closure[i].func; i++) { - if (closure[i].func != probe) - continue; - if (match++ == num) - return closure[i].probe_private; - } - } - break; - } - } - return ERR_PTR(-ENOENT); -} -EXPORT_SYMBOL_GPL(marker_get_private_data); - -#ifdef CONFIG_MODULES - -int marker_module_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - struct module *mod = data; - - switch (val) { - case MODULE_STATE_COMING: - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - break; - case MODULE_STATE_GOING: - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - break; - } - return 0; -} - -struct notifier_block marker_module_nb = { - .notifier_call = marker_module_notify, - .priority = 0, -}; - -static int init_markers(void) -{ - return register_module_notifier(&marker_module_nb); -} -__initcall(init_markers); - -#endif /* CONFIG_MODULES */ diff --git a/kernel/module.c b/kernel/module.c index 05ce49ced8f6..b6ee424245dd 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2237,10 +2237,6 @@ static noinline struct module *load_module(void __user *umod, sizeof(*mod->ctors), &mod->num_ctors); #endif -#ifdef CONFIG_MARKERS - mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers", - sizeof(*mod->markers), &mod->num_markers); -#endif #ifdef CONFIG_TRACEPOINTS mod->tracepoints = section_objs(hdr, sechdrs, secstrings, "__tracepoints", @@ -2958,20 +2954,6 @@ void module_layout(struct module *mod, EXPORT_SYMBOL(module_layout); #endif -#ifdef CONFIG_MARKERS -void module_update_markers(void) -{ - struct module *mod; - - mutex_lock(&module_mutex); - list_for_each_entry(mod, &modules, list) - if (!mod->taints) - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - mutex_unlock(&module_mutex); -} -#endif - #ifdef CONFIG_TRACEPOINTS void module_update_tracepoints(void) { diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 687699d365ae..2547d8813cf0 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -11,7 +11,6 @@ #include #include #include -#include #include #include #include -- cgit v1.2.2 From 28ecd58020409be8eb176c716f957fc3386fa2fa Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 18 Sep 2009 09:50:17 -0700 Subject: rcu: Add WARN_ON_ONCE() consistency checks covering state transitions o Verify that qsmask bits stay clear through GP initialization. o Verify that cpu_quiet_msk_finish() is never invoked unless there actually is an RCU grace period in progress. o Verify that all internal-node rcu_node structures have empty blocked_tasks[] lists. o Verify that child rcu_node structure's bits remain clear after acquiring parent's lock. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <12532926191947-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 13 +++++++++---- kernel/rcutree_plugin.h | 20 ++++++++++++++------ 2 files changed, 23 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 6c99553e9f15..e8624ebf2320 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -628,8 +628,8 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) /* Special-case the common single-level case. */ if (NUM_RCU_NODES == 1) { - rnp->qsmask = rnp->qsmaskinit; rcu_preempt_check_blocked_tasks(rnp); + rnp->qsmask = rnp->qsmaskinit; rnp->gpnum = rsp->gpnum; rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */ spin_unlock_irqrestore(&rnp->lock, flags); @@ -662,8 +662,8 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) rnp_end = &rsp->node[NUM_RCU_NODES]; for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) { spin_lock(&rnp_cur->lock); /* irqs already disabled. */ - rnp_cur->qsmask = rnp_cur->qsmaskinit; rcu_preempt_check_blocked_tasks(rnp); + rnp_cur->qsmask = rnp_cur->qsmaskinit; rnp->gpnum = rsp->gpnum; spin_unlock(&rnp_cur->lock); /* irqs already disabled. */ } @@ -708,6 +708,7 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp) static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags) __releases(rnp->lock) { + WARN_ON_ONCE(rsp->completed == rsp->gpnum); rsp->completed = rsp->gpnum; rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]); rcu_start_gp(rsp, flags); /* releases root node's rnp->lock. */ @@ -725,6 +726,8 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp, unsigned long flags) __releases(rnp->lock) { + struct rcu_node *rnp_c; + /* Walk up the rcu_node hierarchy. */ for (;;) { if (!(rnp->qsmask & mask)) { @@ -748,8 +751,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp, break; } spin_unlock_irqrestore(&rnp->lock, flags); + rnp_c = rnp; rnp = rnp->parent; spin_lock_irqsave(&rnp->lock, flags); + WARN_ON_ONCE(rnp_c->qsmask); } /* @@ -858,7 +863,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) spin_lock_irqsave(&rsp->onofflock, flags); /* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */ - rnp = rdp->mynode; + rnp = rdp->mynode; /* this is the outgoing CPU's rnp. */ mask = rdp->grpmask; /* rnp->grplo is constant. */ do { spin_lock(&rnp->lock); /* irqs already disabled. */ @@ -867,7 +872,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) spin_unlock(&rnp->lock); /* irqs remain disabled. */ break; } - rcu_preempt_offline_tasks(rsp, rnp); + rcu_preempt_offline_tasks(rsp, rnp, rdp); mask = rnp->grpmask; spin_unlock(&rnp->lock); /* irqs remain disabled. */ rnp = rnp->parent; diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index c9616e48379b..5f94619450af 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -206,7 +206,8 @@ static void rcu_read_unlock_special(struct task_struct *t) */ if (!empty && rnp->qsmask == 0 && list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) { - t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; + struct rcu_node *rnp_p; + if (rnp->parent == NULL) { /* Only one rcu_node in the tree. */ cpu_quiet_msk_finish(&rcu_preempt_state, flags); @@ -215,9 +216,10 @@ static void rcu_read_unlock_special(struct task_struct *t) /* Report up the rest of the hierarchy. */ mask = rnp->grpmask; spin_unlock_irqrestore(&rnp->lock, flags); - rnp = rnp->parent; - spin_lock_irqsave(&rnp->lock, flags); - cpu_quiet_msk(mask, &rcu_preempt_state, rnp, flags); + rnp_p = rnp->parent; + spin_lock_irqsave(&rnp_p->lock, flags); + WARN_ON_ONCE(rnp->qsmask); + cpu_quiet_msk(mask, &rcu_preempt_state, rnp_p, flags); return; } spin_unlock(&rnp->lock); @@ -278,6 +280,7 @@ static void rcu_print_task_stall(struct rcu_node *rnp) static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) { WARN_ON_ONCE(!list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])); + WARN_ON_ONCE(rnp->qsmask); } /* @@ -302,7 +305,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp) * The caller must hold rnp->lock with irqs disabled. */ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, - struct rcu_node *rnp) + struct rcu_node *rnp, + struct rcu_data *rdp) { int i; struct list_head *lp; @@ -314,6 +318,9 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, WARN_ONCE(1, "Last CPU thought to be offlined?"); return; /* Shouldn't happen: at least one CPU online. */ } + WARN_ON_ONCE(rnp != rdp->mynode && + (!list_empty(&rnp->blocked_tasks[0]) || + !list_empty(&rnp->blocked_tasks[1]))); /* * Move tasks up to root rcu_node. Rely on the fact that the @@ -489,7 +496,8 @@ static int rcu_preempted_readers(struct rcu_node *rnp) * tasks that were blocked within RCU read-side critical sections. */ static void rcu_preempt_offline_tasks(struct rcu_state *rsp, - struct rcu_node *rnp) + struct rcu_node *rnp, + struct rcu_data *rdp) { } -- cgit v1.2.2 From e7d8842ed34a7fe19d1ed90f84c211fb056ac523 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 18 Sep 2009 09:50:18 -0700 Subject: rcu: Apply results of code inspection of kernel/rcutree_plugin.h o Drop the calls to cpu_quiet() from the online/offline code. These are unnecessary, since force_quiescent_state() will clean up, and removing them simplifies the code a bit. o Add a warning to check that we don't enqueue the same blocked task twice onto the ->blocked_tasks[] lists. o Rework the phase computation in rcu_preempt_note_context_switch() to be more readable, as suggested by Josh Triplett. o Disable irqs to close a race between the scheduling clock interrupt and rcu_preempt_note_context_switch() WRT the ->rcu_read_unlock_special field. o Add comments to rnp->lock acquisition and release within rcu_read_unlock_special() noting that irqs are already disabled. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <12532926201851-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 27 +++++---------------------- kernel/rcutree_plugin.h | 10 ++++++---- 2 files changed, 11 insertions(+), 26 deletions(-) (limited to 'kernel') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index e8624ebf2320..ae4a553e37ce 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -767,10 +767,10 @@ cpu_quiet_msk(unsigned long mask, struct rcu_state *rsp, struct rcu_node *rnp, /* * Record a quiescent state for the specified CPU, which must either be - * the current CPU or an offline CPU. The lastcomp argument is used to - * make sure we are still in the grace period of interest. We don't want - * to end the current grace period based on quiescent states detected in - * an earlier grace period! + * the current CPU. The lastcomp argument is used to make sure we are + * still in the grace period of interest. We don't want to end the current + * grace period based on quiescent states detected in an earlier grace + * period! */ static void cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp) @@ -805,7 +805,6 @@ cpu_quiet(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long lastcomp) * This GP can't end until cpu checks in, so all of our * callbacks can be processed during the next GP. */ - rdp = rsp->rda[smp_processor_id()]; rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL]; cpu_quiet_msk(mask, rsp, rnp, flags); /* releases rnp->lock */ @@ -881,9 +880,6 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ - /* Being offline is a quiescent state, so go record it. */ - cpu_quiet(cpu, rsp, rdp, lastcomp); - /* * Move callbacks from the outgoing CPU to the running CPU. * Note that the outgoing CPU is now quiscent, so it is now @@ -1448,20 +1444,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) rnp = rnp->parent; } while (rnp != NULL && !(rnp->qsmaskinit & mask)); - spin_unlock(&rsp->onofflock); /* irqs remain disabled. */ - - /* - * A new grace period might start here. If so, we will be part of - * it, and its gpnum will be greater than ours, so we will - * participate. It is also possible for the gpnum to have been - * incremented before this function was called, and the bitmasks - * to not be filled out until now, in which case we will also - * participate due to our gpnum being behind. - */ - - /* Since it is coming online, the CPU is in a quiescent state. */ - cpu_quiet(cpu, rsp, rdp, lastcomp); - local_irq_restore(flags); + spin_unlock_irqrestore(&rsp->onofflock, flags); } static void __cpuinit rcu_online_cpu(int cpu) diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 5f94619450af..cd6047cc7fc2 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -117,9 +117,9 @@ static void rcu_preempt_note_context_switch(int cpu) * on line! */ WARN_ON_ONCE((rdp->grpmask & rnp->qsmaskinit) == 0); - phase = !(rnp->qsmask & rdp->grpmask) ^ (rnp->gpnum & 0x1); + WARN_ON_ONCE(!list_empty(&t->rcu_node_entry)); + phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1; list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]); - smp_mb(); /* Ensure later ctxt swtch seen after above. */ spin_unlock_irqrestore(&rnp->lock, flags); } @@ -133,7 +133,9 @@ static void rcu_preempt_note_context_switch(int cpu) * means that we continue to block the current grace period. */ rcu_preempt_qs(cpu); + local_irq_save(flags); t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_NEED_QS; + local_irq_restore(flags); } /* @@ -189,10 +191,10 @@ static void rcu_read_unlock_special(struct task_struct *t) */ for (;;) { rnp = t->rcu_blocked_node; - spin_lock(&rnp->lock); + spin_lock(&rnp->lock); /* irqs already disabled. */ if (rnp == t->rcu_blocked_node) break; - spin_unlock(&rnp->lock); + spin_unlock(&rnp->lock); /* irqs remain disabled. */ } empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]); list_del_init(&t->rcu_node_entry); -- cgit v1.2.2 From 49e291266d0920264471d9d64268fb030e33a99a Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 18 Sep 2009 09:50:19 -0700 Subject: rcu: Fix thinko, actually initialize full tree Commit de078d8 ("rcu: Need to update rnp->gpnum if preemptable RCU is to be reliable") repeatedly and incorrectly initializes the root rcu_node structure's ->gpnum field rather than initializing the ->gpnum field of each node in the tree. Fix this. Also add an additional consistency check to catch this in the future. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <125329262011-git-send-email-> Signed-off-by: Ingo Molnar --- kernel/rcutree.c | 11 ++++------- kernel/rcutree_plugin.h | 4 +++- 2 files changed, 7 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index ae4a553e37ce..1b32cdd1b2e2 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -601,8 +601,6 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) { struct rcu_data *rdp = rsp->rda[smp_processor_id()]; struct rcu_node *rnp = rcu_get_root(rsp); - struct rcu_node *rnp_cur; - struct rcu_node *rnp_end; if (!cpu_needs_another_gp(rsp, rdp)) { spin_unlock_irqrestore(&rnp->lock, flags); @@ -659,13 +657,12 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) * one corresponding to this CPU, due to the fact that we have * irqs disabled. */ - rnp_end = &rsp->node[NUM_RCU_NODES]; - for (rnp_cur = &rsp->node[0]; rnp_cur < rnp_end; rnp_cur++) { - spin_lock(&rnp_cur->lock); /* irqs already disabled. */ + for (rnp = &rsp->node[0]; rnp < &rsp->node[NUM_RCU_NODES]; rnp++) { + spin_lock(&rnp->lock); /* irqs already disabled. */ rcu_preempt_check_blocked_tasks(rnp); - rnp_cur->qsmask = rnp_cur->qsmaskinit; + rnp->qsmask = rnp->qsmaskinit; rnp->gpnum = rsp->gpnum; - spin_unlock(&rnp_cur->lock); /* irqs already disabled. */ + spin_unlock(&rnp->lock); /* irqs already disabled. */ } rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */ diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index cd6047cc7fc2..09b7325baad1 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -476,10 +476,12 @@ static void rcu_print_task_stall(struct rcu_node *rnp) /* * Because there is no preemptable RCU, there can be no readers blocked, - * so there is no need to check for blocked tasks. + * so there is no need to check for blocked tasks. So check only for + * bogus qsmask values. */ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) { + WARN_ON_ONCE(rnp->qsmask); } /* -- cgit v1.2.2 From a71fca58b7f4abca551ae2256ac08dd9123a03f9 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 18 Sep 2009 10:28:19 -0700 Subject: rcu: Fix whitespace inconsistencies Fix a number of whitespace ^Ierrors in the include/linux/rcu* and the kernel/rcu* files. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu LKML-Reference: <20090918172819.GA24405@linux.vnet.ibm.com> [ did more checkpatch fixlets ] Signed-off-by: Ingo Molnar --- kernel/rcupdate.c | 4 ++-- kernel/rcutorture.c | 28 +++++++++++++++------------- kernel/rcutree.c | 2 +- kernel/rcutree.h | 2 +- kernel/rcutree_plugin.h | 3 +-- kernel/rcutree_trace.c | 2 +- 6 files changed, 21 insertions(+), 20 deletions(-) (limited to 'kernel') diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index 28d2f24e7871..37ac45483082 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -19,7 +19,7 @@ * * Authors: Dipankar Sarma * Manfred Spraul - * + * * Based on the original work by Paul McKenney * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * Papers: @@ -27,7 +27,7 @@ * http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001) * * For detailed explanation of Read-Copy Update mechanism see - - * http://lse.sourceforge.net/locking/rcupdate.html + * http://lse.sourceforge.net/locking/rcupdate.html * */ #include diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index 328a8257c885..233768f21f97 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -18,7 +18,7 @@ * Copyright (C) IBM Corporation, 2005, 2006 * * Authors: Paul E. McKenney - * Josh Triplett + * Josh Triplett * * See also: Documentation/RCU/torture.txt */ @@ -50,7 +50,7 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney and " - "Josh Triplett "); + "Josh Triplett "); static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */ static int nfakewriters = 4; /* # fake writer threads */ @@ -110,8 +110,8 @@ struct rcu_torture { }; static LIST_HEAD(rcu_torture_freelist); -static struct rcu_torture *rcu_torture_current = NULL; -static long rcu_torture_current_version = 0; +static struct rcu_torture *rcu_torture_current; +static long rcu_torture_current_version; static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; static DEFINE_SPINLOCK(rcu_torture_lock); static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = @@ -124,11 +124,11 @@ static atomic_t n_rcu_torture_alloc_fail; static atomic_t n_rcu_torture_free; static atomic_t n_rcu_torture_mberror; static atomic_t n_rcu_torture_error; -static long n_rcu_torture_timers = 0; +static long n_rcu_torture_timers; static struct list_head rcu_torture_removed; static cpumask_var_t shuffle_tmp_mask; -static int stutter_pause_test = 0; +static int stutter_pause_test; #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) #define RCUTORTURE_RUNNABLE_INIT 1 @@ -267,7 +267,8 @@ struct rcu_torture_ops { int irq_capable; char *name; }; -static struct rcu_torture_ops *cur_ops = NULL; + +static struct rcu_torture_ops *cur_ops; /* * Definitions for rcu torture testing. @@ -342,8 +343,8 @@ static struct rcu_torture_ops rcu_ops = { .sync = synchronize_rcu, .cb_barrier = rcu_barrier, .stats = NULL, - .irq_capable = 1, - .name = "rcu" + .irq_capable = 1, + .name = "rcu" }; static void rcu_sync_torture_deferred_free(struct rcu_torture *p) @@ -641,7 +642,8 @@ rcu_torture_writer(void *arg) do { schedule_timeout_uninterruptible(1); - if ((rp = rcu_torture_alloc()) == NULL) + rp = rcu_torture_alloc(); + if (rp == NULL) continue; rp->rtort_pipe_count = 0; udelay(rcu_random(&rand) & 0x3ff); @@ -1113,7 +1115,7 @@ rcu_torture_init(void) printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n", torture_type); mutex_unlock(&fullstop_mutex); - return (-EINVAL); + return -EINVAL; } if (cur_ops->init) cur_ops->init(); /* no "goto unwind" prior to this point!!! */ @@ -1164,7 +1166,7 @@ rcu_torture_init(void) goto unwind; } fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), - GFP_KERNEL); + GFP_KERNEL); if (fakewriter_tasks == NULL) { VERBOSE_PRINTK_ERRSTRING("out of memory"); firsterr = -ENOMEM; @@ -1173,7 +1175,7 @@ rcu_torture_init(void) for (i = 0; i < nfakewriters; i++) { VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, - "rcu_torture_fakewriter"); + "rcu_torture_fakewriter"); if (IS_ERR(fakewriter_tasks[i])) { firsterr = PTR_ERR(fakewriter_tasks[i]); VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 1b32cdd1b2e2..52b06f6e158c 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -25,7 +25,7 @@ * and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen. * * For detailed explanation of Read-Copy Update mechanism see - - * Documentation/RCU + * Documentation/RCU */ #include #include diff --git a/kernel/rcutree.h b/kernel/rcutree.h index bf8a6f9f134d..8e8287a983c2 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -142,7 +142,7 @@ struct rcu_data { */ struct rcu_head *nxtlist; struct rcu_head **nxttail[RCU_NEXT_SIZE]; - long qlen; /* # of queued callbacks */ + long qlen; /* # of queued callbacks */ long blimit; /* Upper limit on a processed batch */ #ifdef CONFIG_NO_HZ diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index 09b7325baad1..1cee04f627eb 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -370,9 +370,8 @@ static void rcu_preempt_check_callbacks(int cpu) rcu_preempt_qs(cpu); return; } - if (per_cpu(rcu_preempt_data, cpu).qs_pending) { + if (per_cpu(rcu_preempt_data, cpu).qs_pending) t->rcu_read_unlock_special |= RCU_READ_UNLOCK_NEED_QS; - } } /* diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index 0ea1bff69727..c89f5e9fd173 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -20,7 +20,7 @@ * Papers: http://www.rdrop.com/users/paulmck/RCU * * For detailed explanation of Read-Copy Update mechanism see - - * Documentation/RCU + * Documentation/RCU * */ #include -- cgit v1.2.2 From 393b2ad8c757ba3ccd2a99ca5bbcd6db4d3fa53d Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Sat, 12 Sep 2009 07:52:47 +0200 Subject: perf: Add a timestamp to fork events perf timechart needs to know when a process forked, in order to be able to visualize properly when tasks start. This patch adds a time field to the event structure, and fills it in appropriately. Signed-off-by: Arjan van de Ven Acked-by: Peter Zijlstra Cc: Paul Mackerras Cc: Frederic Weisbecker LKML-Reference: <20090912130341.51ad2de2@infradead.org> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index d013f4e89e9c..d5899b62b276 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -3083,6 +3083,7 @@ struct perf_task_event { u32 ppid; u32 tid; u32 ptid; + u64 time; } event; }; @@ -3090,9 +3091,12 @@ static void perf_counter_task_output(struct perf_counter *counter, struct perf_task_event *task_event) { struct perf_output_handle handle; - int size = task_event->event.header.size; + int size; struct task_struct *task = task_event->task; - int ret = perf_output_begin(&handle, counter, size, 0, 0); + int ret; + + size = task_event->event.header.size; + ret = perf_output_begin(&handle, counter, size, 0, 0); if (ret) return; @@ -3103,7 +3107,10 @@ static void perf_counter_task_output(struct perf_counter *counter, task_event->event.tid = perf_counter_tid(counter, task); task_event->event.ptid = perf_counter_tid(counter, current); + task_event->event.time = perf_clock(); + perf_output_put(&handle, task_event->event); + perf_output_end(&handle); } -- cgit v1.2.2 From 6161352142d5fed4cd753b32e5ccde66e705b14e Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Thu, 17 Sep 2009 16:11:28 +0200 Subject: tracing, perf: Convert the power tracer into an event tracer This patch converts the existing power tracer into an event tracer, so that power events (C states and frequency changes) can be tracked via "perf". This also removes the perl script that was used to demo the tracer; its functionality is being replaced entirely with timechart. Signed-off-by: Arjan van de Ven Acked-by: Peter Zijlstra Cc: Paul Mackerras Cc: Frederic Weisbecker LKML-Reference: <20090912130542.6d314860@infradead.org> Signed-off-by: Ingo Molnar --- kernel/trace/Makefile | 2 +- kernel/trace/power-traces.c | 20 ++++ kernel/trace/trace.h | 3 - kernel/trace/trace_entries.h | 17 ---- kernel/trace/trace_power.c | 218 ------------------------------------------- 5 files changed, 21 insertions(+), 239 deletions(-) create mode 100644 kernel/trace/power-traces.c delete mode 100644 kernel/trace/trace_power.c (limited to 'kernel') diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 844164dca90a..26f03ac07c2b 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -42,7 +42,6 @@ obj-$(CONFIG_BOOT_TRACER) += trace_boot.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o -obj-$(CONFIG_POWER_TRACER) += trace_power.o obj-$(CONFIG_KMEMTRACE) += kmemtrace.o obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o @@ -54,5 +53,6 @@ obj-$(CONFIG_EVENT_TRACING) += trace_export.o obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o obj-$(CONFIG_EVENT_PROFILE) += trace_event_profile.o obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o +obj-$(CONFIG_EVENT_TRACING) += power-traces.o libftrace-y := ftrace.o diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c new file mode 100644 index 000000000000..e06c6e3d56a3 --- /dev/null +++ b/kernel/trace/power-traces.c @@ -0,0 +1,20 @@ +/* + * Power trace points + * + * Copyright (C) 2009 Arjan van de Ven + */ + +#include +#include +#include +#include +#include +#include + +#define CREATE_TRACE_POINTS +#include + +EXPORT_TRACEPOINT_SYMBOL_GPL(power_start); +EXPORT_TRACEPOINT_SYMBOL_GPL(power_end); +EXPORT_TRACEPOINT_SYMBOL_GPL(power_frequency); + diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 86bcff94791a..405cb850b75d 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -11,7 +11,6 @@ #include #include #include -#include #include #include @@ -37,7 +36,6 @@ enum trace_type { TRACE_HW_BRANCHES, TRACE_KMEM_ALLOC, TRACE_KMEM_FREE, - TRACE_POWER, TRACE_BLK, __TRACE_LAST_TYPE, @@ -207,7 +205,6 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry, \ TRACE_GRAPH_RET); \ IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\ - IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \ IF_ASSIGN(var, ent, struct kmemtrace_alloc_entry, \ TRACE_KMEM_ALLOC); \ IF_ASSIGN(var, ent, struct kmemtrace_free_entry, \ diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h index a431748ddd6e..ead3d724599d 100644 --- a/kernel/trace/trace_entries.h +++ b/kernel/trace/trace_entries.h @@ -330,23 +330,6 @@ FTRACE_ENTRY(hw_branch, hw_branch_entry, F_printk("from: %llx to: %llx", __entry->from, __entry->to) ); -FTRACE_ENTRY(power, trace_power, - - TRACE_POWER, - - F_STRUCT( - __field_struct( struct power_trace, state_data ) - __field_desc( s64, state_data, stamp ) - __field_desc( s64, state_data, end ) - __field_desc( int, state_data, type ) - __field_desc( int, state_data, state ) - ), - - F_printk("%llx->%llx type:%u state:%u", - __entry->stamp, __entry->end, - __entry->type, __entry->state) -); - FTRACE_ENTRY(kmem_alloc, kmemtrace_alloc_entry, TRACE_KMEM_ALLOC, diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c deleted file mode 100644 index fe1a00f1445a..000000000000 --- a/kernel/trace/trace_power.c +++ /dev/null @@ -1,218 +0,0 @@ -/* - * ring buffer based C-state tracer - * - * Arjan van de Ven - * Copyright (C) 2008 Intel Corporation - * - * Much is borrowed from trace_boot.c which is - * Copyright (C) 2008 Frederic Weisbecker - * - */ - -#include -#include -#include -#include -#include - -#include "trace.h" -#include "trace_output.h" - -static struct trace_array *power_trace; -static int __read_mostly trace_power_enabled; - -static void probe_power_start(struct power_trace *it, unsigned int type, - unsigned int level) -{ - if (!trace_power_enabled) - return; - - memset(it, 0, sizeof(struct power_trace)); - it->state = level; - it->type = type; - it->stamp = ktime_get(); -} - - -static void probe_power_end(struct power_trace *it) -{ - struct ftrace_event_call *call = &event_power; - struct ring_buffer_event *event; - struct ring_buffer *buffer; - struct trace_power *entry; - struct trace_array_cpu *data; - struct trace_array *tr = power_trace; - - if (!trace_power_enabled) - return; - - buffer = tr->buffer; - - preempt_disable(); - it->end = ktime_get(); - data = tr->data[smp_processor_id()]; - - event = trace_buffer_lock_reserve(buffer, TRACE_POWER, - sizeof(*entry), 0, 0); - if (!event) - goto out; - entry = ring_buffer_event_data(event); - entry->state_data = *it; - if (!filter_check_discard(call, entry, buffer, event)) - trace_buffer_unlock_commit(buffer, event, 0, 0); - out: - preempt_enable(); -} - -static void probe_power_mark(struct power_trace *it, unsigned int type, - unsigned int level) -{ - struct ftrace_event_call *call = &event_power; - struct ring_buffer_event *event; - struct ring_buffer *buffer; - struct trace_power *entry; - struct trace_array_cpu *data; - struct trace_array *tr = power_trace; - - if (!trace_power_enabled) - return; - - buffer = tr->buffer; - - memset(it, 0, sizeof(struct power_trace)); - it->state = level; - it->type = type; - it->stamp = ktime_get(); - preempt_disable(); - it->end = it->stamp; - data = tr->data[smp_processor_id()]; - - event = trace_buffer_lock_reserve(buffer, TRACE_POWER, - sizeof(*entry), 0, 0); - if (!event) - goto out; - entry = ring_buffer_event_data(event); - entry->state_data = *it; - if (!filter_check_discard(call, entry, buffer, event)) - trace_buffer_unlock_commit(buffer, event, 0, 0); - out: - preempt_enable(); -} - -static int tracing_power_register(void) -{ - int ret; - - ret = register_trace_power_start(probe_power_start); - if (ret) { - pr_info("power trace: Couldn't activate tracepoint" - " probe to trace_power_start\n"); - return ret; - } - ret = register_trace_power_end(probe_power_end); - if (ret) { - pr_info("power trace: Couldn't activate tracepoint" - " probe to trace_power_end\n"); - goto fail_start; - } - ret = register_trace_power_mark(probe_power_mark); - if (ret) { - pr_info("power trace: Couldn't activate tracepoint" - " probe to trace_power_mark\n"); - goto fail_end; - } - return ret; -fail_end: - unregister_trace_power_end(probe_power_end); -fail_start: - unregister_trace_power_start(probe_power_start); - return ret; -} - -static void start_power_trace(struct trace_array *tr) -{ - trace_power_enabled = 1; -} - -static void stop_power_trace(struct trace_array *tr) -{ - trace_power_enabled = 0; -} - -static void power_trace_reset(struct trace_array *tr) -{ - trace_power_enabled = 0; - unregister_trace_power_start(probe_power_start); - unregister_trace_power_end(probe_power_end); - unregister_trace_power_mark(probe_power_mark); -} - - -static int power_trace_init(struct trace_array *tr) -{ - power_trace = tr; - - trace_power_enabled = 1; - tracing_power_register(); - - tracing_reset_online_cpus(tr); - return 0; -} - -static enum print_line_t power_print_line(struct trace_iterator *iter) -{ - int ret = 0; - struct trace_entry *entry = iter->ent; - struct trace_power *field ; - struct power_trace *it; - struct trace_seq *s = &iter->seq; - struct timespec stamp; - struct timespec duration; - - trace_assign_type(field, entry); - it = &field->state_data; - stamp = ktime_to_timespec(it->stamp); - duration = ktime_to_timespec(ktime_sub(it->end, it->stamp)); - - if (entry->type == TRACE_POWER) { - if (it->type == POWER_CSTATE) - ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n", - stamp.tv_sec, - stamp.tv_nsec, - it->state, iter->cpu, - duration.tv_sec, - duration.tv_nsec); - if (it->type == POWER_PSTATE) - ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n", - stamp.tv_sec, - stamp.tv_nsec, - it->state, iter->cpu); - if (!ret) - return TRACE_TYPE_PARTIAL_LINE; - return TRACE_TYPE_HANDLED; - } - return TRACE_TYPE_UNHANDLED; -} - -static void power_print_header(struct seq_file *s) -{ - seq_puts(s, "# TIMESTAMP STATE EVENT\n"); - seq_puts(s, "# | | |\n"); -} - -static struct tracer power_tracer __read_mostly = -{ - .name = "power", - .init = power_trace_init, - .start = start_power_trace, - .stop = stop_power_trace, - .reset = power_trace_reset, - .print_line = power_print_line, - .print_header = power_print_header, -}; - -static int init_power_trace(void) -{ - return register_tracer(&power_tracer); -} -device_initcall(init_power_trace); -- cgit v1.2.2 From 3f04e8cd5b24727a2500f8ab8f3de730ba47b02c Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Sat, 19 Sep 2009 16:52:35 +0200 Subject: sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair() While doing some testing, I pinned mplayer, only to find it following X around like a puppy. Looking at commit c88d591, I found a cpu_allowed check that went AWOL. I plugged it back in where it looks like it needs to go, and now when I say "sit, stay!", mplayer obeys again. 'c88d591 sched: Merge select_task_rq_fair() and sched_balance_self()' accidentally dropped the check, causing wake_affine() to pull pinned tasks - put it back. [ v2: use a cheaper version from Peter ] Signed-off-by: Mike Galbraith Acked-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 29b35a7ec571..566e3bb78ed9 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1339,7 +1339,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag int sync = wake_flags & WF_SYNC; if (sd_flag & SD_BALANCE_WAKE) { - if (sched_feat(AFFINE_WAKEUPS)) + if (sched_feat(AFFINE_WAKEUPS) && + cpumask_test_cpu(cpu, &p->cpus_allowed)) want_affine = 1; new_cpu = prev_cpu; } -- cgit v1.2.2 From a4ec5e0c2681b8cf99ddabf118705847f7460f19 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 18 Sep 2009 14:06:28 +0800 Subject: function-graph: use ftrace_graph_funcs directly No need to store ftrace_graph_funcs in file->private. Acked-by: Frederic Weisbecker Signed-off-by: Li Zefan LKML-Reference: <4AB32364.7020602@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 23 ++++------------------- 1 file changed, 4 insertions(+), 19 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index cc615f84751b..c71e91bf7372 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2414,11 +2414,9 @@ unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; static void * __g_next(struct seq_file *m, loff_t *pos) { - unsigned long *array = m->private; - if (*pos >= ftrace_graph_count) return NULL; - return &array[*pos]; + return &ftrace_graph_funcs[*pos]; } static void * @@ -2482,16 +2480,10 @@ ftrace_graph_open(struct inode *inode, struct file *file) ftrace_graph_count = 0; memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); } + mutex_unlock(&graph_lock); - if (file->f_mode & FMODE_READ) { + if (file->f_mode & FMODE_READ) ret = seq_open(file, &ftrace_graph_seq_ops); - if (!ret) { - struct seq_file *m = file->private_data; - m->private = ftrace_graph_funcs; - } - } else - file->private_data = ftrace_graph_funcs; - mutex_unlock(&graph_lock); return ret; } @@ -2560,7 +2552,6 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_parser parser; - unsigned long *array; size_t read = 0; ssize_t ret; @@ -2574,12 +2565,6 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, goto out; } - if (file->f_mode & FMODE_READ) { - struct seq_file *m = file->private_data; - array = m->private; - } else - array = file->private_data; - if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { ret = -ENOMEM; goto out; @@ -2591,7 +2576,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, parser.buffer[parser.idx] = 0; /* we allow only one expression at a time */ - ret = ftrace_set_func(array, &ftrace_graph_count, + ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, parser.buffer); if (ret) goto out; -- cgit v1.2.2 From ee6c2c1bd15e60a442d1861b66285f112ce4f25c Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 18 Sep 2009 14:06:47 +0800 Subject: tracing: remove max_tracer_type_len Limit the length of a tracer's name within 100 chars, and then we don't have to play with max_tracer_type_len. Acked-by: Frederic Weisbecker Signed-off-by: Li Zefan LKML-Reference: <4AB32377.9020601@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 49 ++++++++++++++++--------------------------------- 1 file changed, 16 insertions(+), 33 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index fd52a19dd172..861308072d28 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -125,13 +125,13 @@ int ftrace_dump_on_oops; static int tracing_set_tracer(const char *buf); -#define BOOTUP_TRACER_SIZE 100 -static char bootup_tracer_buf[BOOTUP_TRACER_SIZE] __initdata; +#define MAX_TRACER_SIZE 100 +static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata; static char *default_bootup_tracer; static int __init set_ftrace(char *str) { - strncpy(bootup_tracer_buf, str, BOOTUP_TRACER_SIZE); + strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE); default_bootup_tracer = bootup_tracer_buf; /* We are using ftrace early, expand it */ ring_buffer_expanded = 1; @@ -241,13 +241,6 @@ static struct tracer *trace_types __read_mostly; /* current_trace points to the tracer that is currently active */ static struct tracer *current_trace __read_mostly; -/* - * max_tracer_type_len is used to simplify the allocating of - * buffers to read userspace tracer names. We keep track of - * the longest tracer name registered. - */ -static int max_tracer_type_len; - /* * trace_types_lock is used to protect the trace_types list. * This lock is also used to keep user access serialized. @@ -619,7 +612,6 @@ __releases(kernel_lock) __acquires(kernel_lock) { struct tracer *t; - int len; int ret = 0; if (!type->name) { @@ -627,6 +619,11 @@ __acquires(kernel_lock) return -1; } + if (strlen(type->name) > MAX_TRACER_SIZE) { + pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE); + return -1; + } + /* * When this gets called we hold the BKL which means that * preemption is disabled. Various trace selftests however @@ -641,7 +638,7 @@ __acquires(kernel_lock) for (t = trace_types; t; t = t->next) { if (strcmp(type->name, t->name) == 0) { /* already found */ - pr_info("Trace %s already registered\n", + pr_info("Tracer %s already registered\n", type->name); ret = -1; goto out; @@ -692,9 +689,6 @@ __acquires(kernel_lock) type->next = trace_types; trace_types = type; - len = strlen(type->name); - if (len > max_tracer_type_len) - max_tracer_type_len = len; out: tracing_selftest_running = false; @@ -703,7 +697,7 @@ __acquires(kernel_lock) if (ret || !default_bootup_tracer) goto out_unlock; - if (strncmp(default_bootup_tracer, type->name, BOOTUP_TRACER_SIZE)) + if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE)) goto out_unlock; printk(KERN_INFO "Starting tracer '%s'\n", type->name); @@ -725,14 +719,13 @@ __acquires(kernel_lock) void unregister_tracer(struct tracer *type) { struct tracer **t; - int len; mutex_lock(&trace_types_lock); for (t = &trace_types; *t; t = &(*t)->next) { if (*t == type) goto found; } - pr_info("Trace %s not registered\n", type->name); + pr_info("Tracer %s not registered\n", type->name); goto out; found: @@ -745,17 +738,7 @@ void unregister_tracer(struct tracer *type) current_trace->stop(&global_trace); current_trace = &nop_trace; } - - if (strlen(type->name) != max_tracer_type_len) - goto out; - - max_tracer_type_len = 0; - for (t = &trace_types; *t; t = &(*t)->next) { - len = strlen((*t)->name); - if (len > max_tracer_type_len) - max_tracer_type_len = len; - } - out: +out: mutex_unlock(&trace_types_lock); } @@ -2604,7 +2587,7 @@ static ssize_t tracing_set_trace_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { - char buf[max_tracer_type_len+2]; + char buf[MAX_TRACER_SIZE+2]; int r; mutex_lock(&trace_types_lock); @@ -2754,15 +2737,15 @@ static ssize_t tracing_set_trace_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) { - char buf[max_tracer_type_len+1]; + char buf[MAX_TRACER_SIZE+1]; int i; size_t ret; int err; ret = cnt; - if (cnt > max_tracer_type_len) - cnt = max_tracer_type_len; + if (cnt > MAX_TRACER_SIZE) + cnt = MAX_TRACER_SIZE; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; -- cgit v1.2.2 From 30bd39cd6244ffe3258c9203405286ef77b1c4eb Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 18 Sep 2009 14:07:05 +0800 Subject: tracing/events: use list_for_entry_continue Simplify s_next() and t_next(). Acked-by: Frederic Weisbecker Signed-off-by: Li Zefan LKML-Reference: <4AB32389.1030005@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 49 ++++++++++++++------------------------------- 1 file changed, 15 insertions(+), 34 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 56c260b83a9c..6f03c8a1105e 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -271,42 +271,32 @@ ftrace_event_write(struct file *file, const char __user *ubuf, static void * t_next(struct seq_file *m, void *v, loff_t *pos) { - struct list_head *list = m->private; - struct ftrace_event_call *call; + struct ftrace_event_call *call = v; (*pos)++; - for (;;) { - if (list == &ftrace_events) - return NULL; - - call = list_entry(list, struct ftrace_event_call, list); - + list_for_each_entry_continue(call, &ftrace_events, list) { /* * The ftrace subsystem is for showing formats only. * They can not be enabled or disabled via the event files. */ if (call->regfunc) - break; - - list = list->next; + return call; } - m->private = list->next; - - return call; + return NULL; } static void *t_start(struct seq_file *m, loff_t *pos) { - struct ftrace_event_call *call = NULL; + struct ftrace_event_call *call; loff_t l; mutex_lock(&event_mutex); - m->private = ftrace_events.next; + call = list_entry(&ftrace_events, struct ftrace_event_call, list); for (l = 0; l <= *pos; ) { - call = t_next(m, NULL, &l); + call = t_next(m, call, &l); if (!call) break; } @@ -316,37 +306,28 @@ static void *t_start(struct seq_file *m, loff_t *pos) static void * s_next(struct seq_file *m, void *v, loff_t *pos) { - struct list_head *list = m->private; - struct ftrace_event_call *call; + struct ftrace_event_call *call = v; (*pos)++; - retry: - if (list == &ftrace_events) - return NULL; - - call = list_entry(list, struct ftrace_event_call, list); - - if (!call->enabled) { - list = list->next; - goto retry; + list_for_each_entry_continue(call, &ftrace_events, list) { + if (call->enabled) + return call; } - m->private = list->next; - - return call; + return NULL; } static void *s_start(struct seq_file *m, loff_t *pos) { - struct ftrace_event_call *call = NULL; + struct ftrace_event_call *call; loff_t l; mutex_lock(&event_mutex); - m->private = ftrace_events.next; + call = list_entry(&ftrace_events, struct ftrace_event_call, list); for (l = 0; l <= *pos; ) { - call = s_next(m, NULL, &l); + call = s_next(m, call, &l); if (!call) break; } -- cgit v1.2.2 From cdf8073d6b2c6c5a3cd6ce0e6c1297157f7f99ba Mon Sep 17 00:00:00 2001 From: Ian Schram Date: Fri, 18 Sep 2009 21:26:26 +0200 Subject: perf_counter: Fix perf_copy_attr() pointer arithmetic There is still some weird code in per_copy_attr(). Which supposedly checks that all bytes trailing a struct are zero. It doesn't seem to get pointer arithmetic right. Since it increments an iterating pointer by sizeof(unsigned long) rather than 1. Signed-off-by: Ian Schram [ v2: clean up the messy PTR_ALIGN logic as well. ] Signed-off-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: # for v2.6.31.x LKML-Reference: <4AB3DEE2.3030600@telenet.be> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index d5899b62b276..cc768ab81ac8 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -4208,8 +4208,8 @@ done: static int perf_copy_attr(struct perf_counter_attr __user *uattr, struct perf_counter_attr *attr) { - int ret; u32 size; + int ret; if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) return -EFAULT; @@ -4234,19 +4234,19 @@ static int perf_copy_attr(struct perf_counter_attr __user *uattr, /* * If we're handed a bigger struct than we know of, - * ensure all the unknown bits are 0. + * ensure all the unknown bits are 0 - i.e. new + * user-space does not rely on any kernel feature + * extensions we dont know about yet. */ if (size > sizeof(*attr)) { - unsigned long val; - unsigned long __user *addr; - unsigned long __user *end; + unsigned char __user *addr; + unsigned char __user *end; + unsigned char val; - addr = PTR_ALIGN((void __user *)uattr + sizeof(*attr), - sizeof(unsigned long)); - end = PTR_ALIGN((void __user *)uattr + size, - sizeof(unsigned long)); + addr = (void __user *)uattr + sizeof(*attr); + end = (void __user *)uattr + size; - for (; addr < end; addr += sizeof(unsigned long)) { + for (; addr < end; addr++) { ret = get_user(val, addr); if (ret) return ret; -- cgit v1.2.2 From f8a7c1a976a6672204c7f4f0f694f33715dfa617 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Sat, 19 Sep 2009 13:13:17 -0700 Subject: kfifo: Use "const" definitions Currently kfifo cannot be used by parts of the kernel that use "const" properly as kfifo itself does not use const for passed data blocks which are indeed const. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- kernel/kfifo.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/kfifo.c b/kernel/kfifo.c index 26539e3228e5..3765ff3c1bbe 100644 --- a/kernel/kfifo.c +++ b/kernel/kfifo.c @@ -117,7 +117,7 @@ EXPORT_SYMBOL(kfifo_free); * writer, you don't need extra locking to use these functions. */ unsigned int __kfifo_put(struct kfifo *fifo, - unsigned char *buffer, unsigned int len) + const unsigned char *buffer, unsigned int len) { unsigned int l; -- cgit v1.2.2 From 8d233558cd99a888571bb5a88a74970879e0aba4 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Sat, 19 Sep 2009 13:13:25 -0700 Subject: vt: remove power stuff from kernel/power In the past someone gratuitiously borrowed chunks of kernel internal vt code and dumped them in kernel/power. They have all sorts of deep relations with the vt code so put them in the vt tree instead Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- kernel/power/console.c | 63 ++++---------------------------------------------- 1 file changed, 5 insertions(+), 58 deletions(-) (limited to 'kernel') diff --git a/kernel/power/console.c b/kernel/power/console.c index a3961b205de7..5187136fe1de 100644 --- a/kernel/power/console.c +++ b/kernel/power/console.c @@ -14,56 +14,13 @@ #define SUSPEND_CONSOLE (MAX_NR_CONSOLES-1) static int orig_fgconsole, orig_kmsg; -static int disable_vt_switch; - -/* - * Normally during a suspend, we allocate a new console and switch to it. - * When we resume, we switch back to the original console. This switch - * can be slow, so on systems where the framebuffer can handle restoration - * of video registers anyways, there's little point in doing the console - * switch. This function allows you to disable it by passing it '0'. - */ -void pm_set_vt_switch(int do_switch) -{ - acquire_console_sem(); - disable_vt_switch = !do_switch; - release_console_sem(); -} -EXPORT_SYMBOL(pm_set_vt_switch); int pm_prepare_console(void) { - acquire_console_sem(); - - if (disable_vt_switch) { - release_console_sem(); - return 0; - } - - orig_fgconsole = fg_console; - - if (vc_allocate(SUSPEND_CONSOLE)) { - /* we can't have a free VC for now. Too bad, - * we don't want to mess the screen for now. */ - release_console_sem(); + orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1); + if (orig_fgconsole < 0) return 1; - } - if (set_console(SUSPEND_CONSOLE)) { - /* - * We're unable to switch to the SUSPEND_CONSOLE. - * Let the calling function know so it can decide - * what to do. - */ - release_console_sem(); - return 1; - } - release_console_sem(); - - if (vt_waitactive(SUSPEND_CONSOLE)) { - pr_debug("Suspend: Can't switch VCs."); - return 1; - } orig_kmsg = kmsg_redirect; kmsg_redirect = SUSPEND_CONSOLE; return 0; @@ -71,19 +28,9 @@ int pm_prepare_console(void) void pm_restore_console(void) { - acquire_console_sem(); - if (disable_vt_switch) { - release_console_sem(); - return; - } - set_console(orig_fgconsole); - release_console_sem(); - - if (vt_waitactive(orig_fgconsole)) { - pr_debug("Resume: Can't switch VCs."); - return; + if (orig_fgconsole >= 0) { + vt_move_to_console(orig_fgconsole, 0); + kmsg_redirect = orig_kmsg; } - - kmsg_redirect = orig_kmsg; } #endif -- cgit v1.2.2 From a0f320f48799f67329fcb1b26ff0451c304e1dde Mon Sep 17 00:00:00 2001 From: Jaswinder Singh Rajput Date: Sun, 20 Sep 2009 16:31:16 +0530 Subject: includecheck fix: kernel/trace, ring_buffer.c fix the following 'make includecheck' warning: kernel/trace/ring_buffer.c: trace.h is included more than once. Signed-off-by: Jaswinder Singh Rajput Cc: Steven Rostedt Cc: Ingo Molnar Cc: Sam Ravnborg LKML-Reference: <1247068617.4382.107.camel@ht.satnam> --- kernel/trace/ring_buffer.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 6eef38923b07..d4ff01970547 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -201,8 +201,6 @@ int tracing_is_on(void) } EXPORT_SYMBOL_GPL(tracing_is_on); -#include "trace.h" - #define RB_EVNT_HDR_SIZE (offsetof(struct ring_buffer_event, array)) #define RB_ALIGNMENT 4U #define RB_MAX_SMALL_DATA (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX) -- cgit v1.2.2 From 05bafda856092de0705de239c846777bddb94974 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sun, 20 Sep 2009 12:34:38 +0200 Subject: tracing: Export trace_profile_buf symbols ERROR: "trace_profile_buf_nmi" [fs/jbd2/jbd2.ko] undefined! ERROR: "trace_profile_buf" [fs/jbd2/jbd2.ko] undefined! ERROR: "trace_profile_buf_nmi" [fs/ext4/ext4.ko] undefined! ERROR: "trace_profile_buf" [fs/ext4/ext4.ko] undefined! ERROR: "trace_profile_buf_nmi" [arch/x86/kvm/kvm.ko] undefined! ERROR: "trace_profile_buf" [arch/x86/kvm/kvm.ko] undefined! Signed-off-by: Peter Zijlstra Acked-by: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <1253442878.7542.3.camel@laptop> [ fixed whitespace noise and checkpatch complaint ] Signed-off-by: Ingo Molnar --- kernel/trace/trace_event_profile.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index 3aaa77c3309b..dd44b8768867 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -15,7 +15,10 @@ typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t; char *trace_profile_buf; -char *trace_profile_buf_nmi; +EXPORT_SYMBOL_GPL(trace_profile_buf); + +char *trace_profile_buf_nmi; +EXPORT_SYMBOL_GPL(trace_profile_buf_nmi); /* Count the events in use (per event id, not per instance) */ static int total_profile_count; -- cgit v1.2.2 From 89f19f04dc72363d912fd007a399cb10310eff6e Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sat, 19 Sep 2009 11:55:44 -0700 Subject: sched: Fix raciness in runqueue_is_locked() runqueue_is_locked() is unavoidably racy due to a poor interface design. It does cpu = get_cpu() ret = some_perpcu_thing(cpu); put_cpu(cpu); return ret; Its return value is unreliable. Fix. Signed-off-by: Andrew Morton Acked-by: Steven Rostedt Cc: Peter Zijlstra LKML-Reference: <200909191855.n8JItiko022148@imap1.linux-foundation.org> Signed-off-by: Ingo Molnar --- kernel/sched.c | 10 ++-------- kernel/trace/trace.c | 8 +++++++- 2 files changed, 9 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index faf4d463bbff..575fb0139038 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -681,15 +681,9 @@ inline void update_rq_clock(struct rq *rq) * This interface allows printk to be called with the runqueue lock * held and know whether or not it is OK to wake up the klogd. */ -int runqueue_is_locked(void) +int runqueue_is_locked(int cpu) { - int cpu = get_cpu(); - struct rq *rq = cpu_rq(cpu); - int ret; - - ret = spin_is_locked(&rq->lock); - put_cpu(); - return ret; + return spin_is_locked(&cpu_rq(cpu)->lock); } /* diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index fd52a19dd172..420232a1fbba 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -275,12 +275,18 @@ static DEFINE_SPINLOCK(tracing_start_lock); */ void trace_wake_up(void) { + int cpu; + + if (trace_flags & TRACE_ITER_BLOCK) + return; /* * The runqueue_is_locked() can fail, but this is the best we * have for now: */ - if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked()) + cpu = get_cpu(); + if (!runqueue_is_locked(cpu)) wake_up(&trace_wait); + put_cpu(); } static int __init set_buf_size(char *str) -- cgit v1.2.2 From 583a22e7c154dc0a3938db522696b4bc7f098f59 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Fri, 18 Sep 2009 12:57:09 -0700 Subject: kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_file Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/profile.c | 45 ++++++++++++++++++++++++--------------------- 1 file changed, 24 insertions(+), 21 deletions(-) (limited to 'kernel') diff --git a/kernel/profile.c b/kernel/profile.c index 419250ebec4d..a55d3a367ae8 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -442,48 +442,51 @@ void profile_tick(int type) #ifdef CONFIG_PROC_FS #include +#include #include -static int prof_cpu_mask_read_proc(char *page, char **start, off_t off, - int count, int *eof, void *data) +static int prof_cpu_mask_proc_show(struct seq_file *m, void *v) { - int len = cpumask_scnprintf(page, count, data); - if (count - len < 2) - return -EINVAL; - len += sprintf(page + len, "\n"); - return len; + seq_cpumask(m, prof_cpu_mask); + seq_putc(m, '\n'); + return 0; } -static int prof_cpu_mask_write_proc(struct file *file, - const char __user *buffer, unsigned long count, void *data) +static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, prof_cpu_mask_proc_show, NULL); +} + +static ssize_t prof_cpu_mask_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) { - struct cpumask *mask = data; - unsigned long full_count = count, err; cpumask_var_t new_value; + int err; if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM; err = cpumask_parse_user(buffer, count, new_value); if (!err) { - cpumask_copy(mask, new_value); - err = full_count; + cpumask_copy(prof_cpu_mask, new_value); + err = count; } free_cpumask_var(new_value); return err; } +static const struct file_operations prof_cpu_mask_proc_fops = { + .open = prof_cpu_mask_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = prof_cpu_mask_proc_write, +}; + void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir) { - struct proc_dir_entry *entry; - /* create /proc/irq/prof_cpu_mask */ - entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir); - if (!entry) - return; - entry->data = prof_cpu_mask; - entry->read_proc = prof_cpu_mask_read_proc; - entry->write_proc = prof_cpu_mask_write_proc; + proc_create("prof_cpu_mask", 0600, root_irq_dir, &prof_cpu_mask_proc_fops); } /* -- cgit v1.2.2 From cb5fd13f1178dee4302646b2890d884c380160e1 Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Mon, 14 Sep 2009 20:20:16 +0800 Subject: sched: Fix potential NULL derference of doms_cur If CONFIG_CPUMASK_OFFSTACK is enabled but doms_cur alloc failed in arch_init_sched_domains(), doms_cur will move back to fallback_doms. But this time, fallback_doms has not been initialized yet. Signed-off-by: Yong Zhang Cc: a.p.zijlstra@chello.nl LKML-Reference: <1252930816-7672-1-git-send-email-yong.zhang0@gmail.com> Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 575fb0139038..1b900fb1c6e1 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -9165,6 +9165,7 @@ void __init sched_init_smp(void) cpumask_var_t non_isolated_cpus; alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); + alloc_cpumask_var(&fallback_doms, GFP_KERNEL); #if defined(CONFIG_NUMA) sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), @@ -9196,7 +9197,6 @@ void __init sched_init_smp(void) sched_init_granularity(); free_cpumask_var(non_isolated_cpus); - alloc_cpumask_var(&fallback_doms, GFP_KERNEL); init_sched_rt_class(); } #else -- cgit v1.2.2 From 0d721ceadbeaa24d7f9dd41b3e5e29912327a7e1 Mon Sep 17 00:00:00 2001 From: Peter Williams Date: Mon, 21 Sep 2009 01:31:53 +0000 Subject: sched: Simplify sys_sched_rr_get_interval() system call By removing the need for it to know details of scheduling classes. This allows PlugSched to define orthogonal scheduling classes. Signed-off-by: Peter Williams Acked-by: Peter Zijlstra Cc: Mike Galbraith LKML-Reference: <06d1b89ee15a0eef82d7.1253496713@mudlark.pw.nest> Signed-off-by: Ingo Molnar --- kernel/sched.c | 17 +---------------- kernel/sched_fair.c | 21 +++++++++++++++++++++ kernel/sched_idletask.c | 7 +++++++ kernel/sched_rt.c | 13 +++++++++++++ 4 files changed, 42 insertions(+), 16 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 1b900fb1c6e1..830967e18285 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6819,23 +6819,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, if (retval) goto out_unlock; - /* - * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER - * tasks that are on an otherwise idle runqueue: - */ - time_slice = 0; - if (p->policy == SCHED_RR) { - time_slice = DEF_TIMESLICE; - } else if (p->policy != SCHED_FIFO) { - struct sched_entity *se = &p->se; - unsigned long flags; - struct rq *rq; + time_slice = p->sched_class->get_rr_interval(p); - rq = task_rq_lock(p, &flags); - if (rq->cfs.load.weight) - time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); - task_rq_unlock(rq, &flags); - } read_unlock(&tasklist_lock); jiffies_to_timespec(time_slice, &t); retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 566e3bb78ed9..cd73738f0d5f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1938,6 +1938,25 @@ static void moved_group_fair(struct task_struct *p) } #endif +unsigned int get_rr_interval_fair(struct task_struct *task) +{ + struct sched_entity *se = &task->se; + unsigned long flags; + struct rq *rq; + unsigned int rr_interval = 0; + + /* + * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise + * idle runqueue: + */ + rq = task_rq_lock(task, &flags); + if (rq->cfs.load.weight) + rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); + task_rq_unlock(rq, &flags); + + return rr_interval; +} + /* * All the scheduling class methods: */ @@ -1966,6 +1985,8 @@ static const struct sched_class fair_sched_class = { .prio_changed = prio_changed_fair, .switched_to = switched_to_fair, + .get_rr_interval = get_rr_interval_fair, + #ifdef CONFIG_FAIR_GROUP_SCHED .moved_group = moved_group_fair, #endif diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index a8b448af004b..b133a28fcde3 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -97,6 +97,11 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p, check_preempt_curr(rq, p, 0); } +unsigned int get_rr_interval_idle(struct task_struct *task) +{ + return 0; +} + /* * Simple, special scheduling class for the per-CPU idle tasks: */ @@ -122,6 +127,8 @@ static const struct sched_class idle_sched_class = { .set_curr_task = set_curr_task_idle, .task_tick = task_tick_idle, + .get_rr_interval = get_rr_interval_idle, + .prio_changed = prio_changed_idle, .switched_to = switched_to_idle, diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 13de7126a6ab..a4d790cddb19 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -1734,6 +1734,17 @@ static void set_curr_task_rt(struct rq *rq) dequeue_pushable_task(rq, p); } +unsigned int get_rr_interval_rt(struct task_struct *task) +{ + /* + * Time slice is 0 for SCHED_FIFO tasks + */ + if (task->policy == SCHED_RR) + return DEF_TIMESLICE; + else + return 0; +} + static const struct sched_class rt_sched_class = { .next = &fair_sched_class, .enqueue_task = enqueue_task_rt, @@ -1762,6 +1773,8 @@ static const struct sched_class rt_sched_class = { .set_curr_task = set_curr_task_rt, .task_tick = task_tick_rt, + .get_rr_interval = get_rr_interval_rt, + .prio_changed = prio_changed_rt, .switched_to = switched_to_rt, }; -- cgit v1.2.2 From 65abc8653c282ded3dbdb9ec1227784140ba28cd Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 10:18:27 +0200 Subject: perf_counter: Rename list_entry -> group_entry, counter_list -> group_list This is in preparation of the big rename, but also makes sense in a standalone way: 'list_entry' is a bad name as we already have a list_entry() in list.h. Also, the 'counter list' is too vague, it doesnt tell us the purpose of that list. Clarify these names to show that it's all about the group hiearchy. Acked-by: Peter Zijlstra Cc: Paul Mackerras Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 71 +++++++++++++++++++++++++-------------------------- 1 file changed, 35 insertions(+), 36 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index cc768ab81ac8..13ad73aed4ca 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -258,9 +258,9 @@ list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx) * leader's sibling list: */ if (group_leader == counter) - list_add_tail(&counter->list_entry, &ctx->counter_list); + list_add_tail(&counter->group_entry, &ctx->group_list); else { - list_add_tail(&counter->list_entry, &group_leader->sibling_list); + list_add_tail(&counter->group_entry, &group_leader->sibling_list); group_leader->nr_siblings++; } @@ -279,13 +279,13 @@ list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) { struct perf_counter *sibling, *tmp; - if (list_empty(&counter->list_entry)) + if (list_empty(&counter->group_entry)) return; ctx->nr_counters--; if (counter->attr.inherit_stat) ctx->nr_stat--; - list_del_init(&counter->list_entry); + list_del_init(&counter->group_entry); list_del_rcu(&counter->event_entry); if (counter->group_leader != counter) @@ -296,10 +296,9 @@ list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) * upgrade the siblings to singleton counters by adding them * to the context list directly: */ - list_for_each_entry_safe(sibling, tmp, - &counter->sibling_list, list_entry) { + list_for_each_entry_safe(sibling, tmp, &counter->sibling_list, group_entry) { - list_move_tail(&sibling->list_entry, &ctx->counter_list); + list_move_tail(&sibling->group_entry, &ctx->group_list); sibling->group_leader = sibling; } } @@ -343,7 +342,7 @@ group_sched_out(struct perf_counter *group_counter, /* * Schedule out siblings (if any): */ - list_for_each_entry(counter, &group_counter->sibling_list, list_entry) + list_for_each_entry(counter, &group_counter->sibling_list, group_entry) counter_sched_out(counter, cpuctx, ctx); if (group_counter->attr.exclusive) @@ -435,7 +434,7 @@ retry: /* * If the context is active we need to retry the smp call. */ - if (ctx->nr_active && !list_empty(&counter->list_entry)) { + if (ctx->nr_active && !list_empty(&counter->group_entry)) { spin_unlock_irq(&ctx->lock); goto retry; } @@ -445,7 +444,7 @@ retry: * can remove the counter safely, if the call above did not * succeed. */ - if (!list_empty(&counter->list_entry)) { + if (!list_empty(&counter->group_entry)) { list_del_counter(counter, ctx); } spin_unlock_irq(&ctx->lock); @@ -497,7 +496,7 @@ static void update_group_times(struct perf_counter *leader) struct perf_counter *counter; update_counter_times(leader); - list_for_each_entry(counter, &leader->sibling_list, list_entry) + list_for_each_entry(counter, &leader->sibling_list, group_entry) update_counter_times(counter); } @@ -643,7 +642,7 @@ group_sched_in(struct perf_counter *group_counter, /* * Schedule in siblings as one group (if any): */ - list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { + list_for_each_entry(counter, &group_counter->sibling_list, group_entry) { if (counter_sched_in(counter, cpuctx, ctx, cpu)) { partial_group = counter; goto group_error; @@ -657,7 +656,7 @@ group_error: * Groups can be scheduled in as one unit only, so undo any * partial group before returning: */ - list_for_each_entry(counter, &group_counter->sibling_list, list_entry) { + list_for_each_entry(counter, &group_counter->sibling_list, group_entry) { if (counter == partial_group) break; counter_sched_out(counter, cpuctx, ctx); @@ -678,7 +677,7 @@ static int is_software_only_group(struct perf_counter *leader) if (!is_software_counter(leader)) return 0; - list_for_each_entry(counter, &leader->sibling_list, list_entry) + list_for_each_entry(counter, &leader->sibling_list, group_entry) if (!is_software_counter(counter)) return 0; @@ -842,7 +841,7 @@ retry: /* * we need to retry the smp call. */ - if (ctx->is_active && list_empty(&counter->list_entry)) { + if (ctx->is_active && list_empty(&counter->group_entry)) { spin_unlock_irq(&ctx->lock); goto retry; } @@ -852,7 +851,7 @@ retry: * can add the counter safely, if it the call above did not * succeed. */ - if (list_empty(&counter->list_entry)) + if (list_empty(&counter->group_entry)) add_counter_to_ctx(counter, ctx); spin_unlock_irq(&ctx->lock); } @@ -872,7 +871,7 @@ static void __perf_counter_mark_enabled(struct perf_counter *counter, counter->state = PERF_COUNTER_STATE_INACTIVE; counter->tstamp_enabled = ctx->time - counter->total_time_enabled; - list_for_each_entry(sub, &counter->sibling_list, list_entry) + list_for_each_entry(sub, &counter->sibling_list, group_entry) if (sub->state >= PERF_COUNTER_STATE_INACTIVE) sub->tstamp_enabled = ctx->time - sub->total_time_enabled; @@ -1032,7 +1031,7 @@ void __perf_counter_sched_out(struct perf_counter_context *ctx, perf_disable(); if (ctx->nr_active) { - list_for_each_entry(counter, &ctx->counter_list, list_entry) { + list_for_each_entry(counter, &ctx->group_list, group_entry) { if (counter != counter->group_leader) counter_sched_out(counter, cpuctx, ctx); else @@ -1252,7 +1251,7 @@ __perf_counter_sched_in(struct perf_counter_context *ctx, * First go through the list and put on any pinned groups * in order to give them the best chance of going on. */ - list_for_each_entry(counter, &ctx->counter_list, list_entry) { + list_for_each_entry(counter, &ctx->group_list, group_entry) { if (counter->state <= PERF_COUNTER_STATE_OFF || !counter->attr.pinned) continue; @@ -1276,7 +1275,7 @@ __perf_counter_sched_in(struct perf_counter_context *ctx, } } - list_for_each_entry(counter, &ctx->counter_list, list_entry) { + list_for_each_entry(counter, &ctx->group_list, group_entry) { /* * Ignore counters in OFF or ERROR state, and * ignore pinned counters since we did them already. @@ -1369,7 +1368,7 @@ static void perf_ctx_adjust_freq(struct perf_counter_context *ctx) u64 interrupts, freq; spin_lock(&ctx->lock); - list_for_each_entry(counter, &ctx->counter_list, list_entry) { + list_for_each_entry(counter, &ctx->group_list, group_entry) { if (counter->state != PERF_COUNTER_STATE_ACTIVE) continue; @@ -1441,8 +1440,8 @@ static void rotate_ctx(struct perf_counter_context *ctx) * Rotate the first entry last (works just fine for group counters too): */ perf_disable(); - list_for_each_entry(counter, &ctx->counter_list, list_entry) { - list_move_tail(&counter->list_entry, &ctx->counter_list); + list_for_each_entry(counter, &ctx->group_list, group_entry) { + list_move_tail(&counter->group_entry, &ctx->group_list); break; } perf_enable(); @@ -1498,7 +1497,7 @@ static void perf_counter_enable_on_exec(struct task_struct *task) spin_lock(&ctx->lock); - list_for_each_entry(counter, &ctx->counter_list, list_entry) { + list_for_each_entry(counter, &ctx->group_list, group_entry) { if (!counter->attr.enable_on_exec) continue; counter->attr.enable_on_exec = 0; @@ -1575,7 +1574,7 @@ __perf_counter_init_context(struct perf_counter_context *ctx, memset(ctx, 0, sizeof(*ctx)); spin_lock_init(&ctx->lock); mutex_init(&ctx->mutex); - INIT_LIST_HEAD(&ctx->counter_list); + INIT_LIST_HEAD(&ctx->group_list); INIT_LIST_HEAD(&ctx->event_list); atomic_set(&ctx->refcount, 1); ctx->task = task; @@ -1818,7 +1817,7 @@ static int perf_counter_read_group(struct perf_counter *counter, size += err; - list_for_each_entry(sub, &leader->sibling_list, list_entry) { + list_for_each_entry(sub, &leader->sibling_list, group_entry) { err = perf_counter_read_entry(sub, read_format, buf + size); if (err < 0) @@ -1948,7 +1947,7 @@ static void perf_counter_for_each(struct perf_counter *counter, perf_counter_for_each_child(counter, func); func(counter); - list_for_each_entry(sibling, &counter->sibling_list, list_entry) + list_for_each_entry(sibling, &counter->sibling_list, group_entry) perf_counter_for_each_child(counter, func); mutex_unlock(&ctx->mutex); } @@ -2832,7 +2831,7 @@ static void perf_output_read_group(struct perf_output_handle *handle, perf_output_copy(handle, values, n * sizeof(u64)); - list_for_each_entry(sub, &leader->sibling_list, list_entry) { + list_for_each_entry(sub, &leader->sibling_list, group_entry) { n = 0; if (sub != counter) @@ -4118,7 +4117,7 @@ perf_counter_alloc(struct perf_counter_attr *attr, mutex_init(&counter->child_mutex); INIT_LIST_HEAD(&counter->child_list); - INIT_LIST_HEAD(&counter->list_entry); + INIT_LIST_HEAD(&counter->group_entry); INIT_LIST_HEAD(&counter->event_entry); INIT_LIST_HEAD(&counter->sibling_list); init_waitqueue_head(&counter->waitq); @@ -4544,7 +4543,7 @@ static int inherit_group(struct perf_counter *parent_counter, child, NULL, child_ctx); if (IS_ERR(leader)) return PTR_ERR(leader); - list_for_each_entry(sub, &parent_counter->sibling_list, list_entry) { + list_for_each_entry(sub, &parent_counter->sibling_list, group_entry) { child_ctr = inherit_counter(sub, parent, parent_ctx, child, leader, child_ctx); if (IS_ERR(child_ctr)) @@ -4670,8 +4669,8 @@ void perf_counter_exit_task(struct task_struct *child) mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); again: - list_for_each_entry_safe(child_counter, tmp, &child_ctx->counter_list, - list_entry) + list_for_each_entry_safe(child_counter, tmp, &child_ctx->group_list, + group_entry) __perf_counter_exit_task(child_counter, child_ctx, child); /* @@ -4679,7 +4678,7 @@ again: * its siblings to the list, but we obtained 'tmp' before that which * will still point to the list head terminating the iteration. */ - if (!list_empty(&child_ctx->counter_list)) + if (!list_empty(&child_ctx->group_list)) goto again; mutex_unlock(&child_ctx->mutex); @@ -4701,7 +4700,7 @@ void perf_counter_free_task(struct task_struct *task) mutex_lock(&ctx->mutex); again: - list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) { + list_for_each_entry_safe(counter, tmp, &ctx->group_list, group_entry) { struct perf_counter *parent = counter->parent; if (WARN_ON_ONCE(!parent)) @@ -4717,7 +4716,7 @@ again: free_counter(counter); } - if (!list_empty(&ctx->counter_list)) + if (!list_empty(&ctx->group_list)) goto again; mutex_unlock(&ctx->mutex); @@ -4847,7 +4846,7 @@ static void __perf_counter_exit_cpu(void *info) struct perf_counter_context *ctx = &cpuctx->ctx; struct perf_counter *counter, *tmp; - list_for_each_entry_safe(counter, tmp, &ctx->counter_list, list_entry) + list_for_each_entry_safe(counter, tmp, &ctx->group_list, group_entry) __perf_counter_remove_from_context(counter); } static void perf_counter_exit_cpu(int cpu) -- cgit v1.2.2 From dfc65094d0313cc48969fa60bcf33d693aeb05a7 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 11:31:35 +0200 Subject: perf_counter: Rename 'event' to event_id/hw_event In preparation to the renames, to avoid a namespace clash. Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 13ad73aed4ca..62de0db8092b 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -3044,22 +3044,22 @@ perf_counter_read_event(struct perf_counter *counter, struct task_struct *task) { struct perf_output_handle handle; - struct perf_read_event event = { + struct perf_read_event read_event = { .header = { .type = PERF_EVENT_READ, .misc = 0, - .size = sizeof(event) + perf_counter_read_size(counter), + .size = sizeof(read_event) + perf_counter_read_size(counter), }, .pid = perf_counter_pid(counter, task), .tid = perf_counter_tid(counter, task), }; int ret; - ret = perf_output_begin(&handle, counter, event.header.size, 0, 0); + ret = perf_output_begin(&handle, counter, read_event.header.size, 0, 0); if (ret) return; - perf_output_put(&handle, event); + perf_output_put(&handle, read_event); perf_output_read(&handle, counter); perf_output_end(&handle); @@ -3698,14 +3698,14 @@ static int perf_swcounter_is_counting(struct perf_counter *counter) static int perf_swcounter_match(struct perf_counter *counter, enum perf_type_id type, - u32 event, struct pt_regs *regs) + u32 event_id, struct pt_regs *regs) { if (!perf_swcounter_is_counting(counter)) return 0; if (counter->attr.type != type) return 0; - if (counter->attr.config != event) + if (counter->attr.config != event_id) return 0; if (regs) { @@ -3721,7 +3721,7 @@ static int perf_swcounter_match(struct perf_counter *counter, static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, enum perf_type_id type, - u32 event, u64 nr, int nmi, + u32 event_id, u64 nr, int nmi, struct perf_sample_data *data, struct pt_regs *regs) { @@ -3732,7 +3732,7 @@ static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, rcu_read_lock(); list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_swcounter_match(counter, type, event, regs)) + if (perf_swcounter_match(counter, type, event_id, regs)) perf_swcounter_add(counter, nr, nmi, data, regs); } rcu_read_unlock(); @@ -4036,17 +4036,17 @@ atomic_t perf_swcounter_enabled[PERF_COUNT_SW_MAX]; static void sw_perf_counter_destroy(struct perf_counter *counter) { - u64 event = counter->attr.config; + u64 event_id = counter->attr.config; WARN_ON(counter->parent); - atomic_dec(&perf_swcounter_enabled[event]); + atomic_dec(&perf_swcounter_enabled[event_id]); } static const struct pmu *sw_perf_counter_init(struct perf_counter *counter) { const struct pmu *pmu = NULL; - u64 event = counter->attr.config; + u64 event_id = counter->attr.config; /* * Software counters (currently) can't in general distinguish @@ -4055,7 +4055,7 @@ static const struct pmu *sw_perf_counter_init(struct perf_counter *counter) * to be kernel events, and page faults are never hypervisor * events. */ - switch (event) { + switch (event_id) { case PERF_COUNT_SW_CPU_CLOCK: pmu = &perf_ops_cpu_clock; @@ -4077,7 +4077,7 @@ static const struct pmu *sw_perf_counter_init(struct perf_counter *counter) case PERF_COUNT_SW_CONTEXT_SWITCHES: case PERF_COUNT_SW_CPU_MIGRATIONS: if (!counter->parent) { - atomic_inc(&perf_swcounter_enabled[event]); + atomic_inc(&perf_swcounter_enabled[event_id]); counter->destroy = sw_perf_counter_destroy; } pmu = &perf_ops_generic; -- cgit v1.2.2 From cdd6c482c9ff9c55475ee7392ec8f672eddb7be6 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 12:02:48 +0200 Subject: perf: Do the big rename: Performance Counters -> Performance Events Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian Acked-by: Peter Zijlstra Acked-by: Paul Mackerras Reviewed-by: Arjan van de Ven Cc: Mike Galbraith Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Steven Rostedt Cc: Benjamin Herrenschmidt Cc: David Howells Cc: Kyle McMartin Cc: Martin Schwidefsky Cc: "David S. Miller" Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/Makefile | 2 +- kernel/exit.c | 8 +- kernel/fork.c | 8 +- kernel/perf_counter.c | 5000 ----------------------------------------- kernel/perf_event.c | 5000 +++++++++++++++++++++++++++++++++++++++++ kernel/sched.c | 14 +- kernel/sys.c | 10 +- kernel/sys_ni.c | 2 +- kernel/sysctl.c | 22 +- kernel/timer.c | 4 +- kernel/trace/trace_syscalls.c | 6 +- 11 files changed, 5038 insertions(+), 5038 deletions(-) delete mode 100644 kernel/perf_counter.c create mode 100644 kernel/perf_event.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 3d9c7e27e3f9..e26a546eac44 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -96,7 +96,7 @@ obj-$(CONFIG_X86_DS) += trace/ obj-$(CONFIG_RING_BUFFER) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o obj-$(CONFIG_SLOW_WORK) += slow-work.o -obj-$(CONFIG_PERF_COUNTERS) += perf_counter.o +obj-$(CONFIG_PERF_EVENTS) += perf_event.o ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra , the -fno-omit-frame-pointer is diff --git a/kernel/exit.c b/kernel/exit.c index ae5d8660ddff..e47ee8a06135 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -47,7 +47,7 @@ #include #include #include -#include +#include #include #include @@ -154,8 +154,8 @@ static void delayed_put_task_struct(struct rcu_head *rhp) { struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); -#ifdef CONFIG_PERF_COUNTERS - WARN_ON_ONCE(tsk->perf_counter_ctxp); +#ifdef CONFIG_PERF_EVENTS + WARN_ON_ONCE(tsk->perf_event_ctxp); #endif trace_sched_process_free(tsk); put_task_struct(tsk); @@ -981,7 +981,7 @@ NORET_TYPE void do_exit(long code) * Flush inherited counters to the parent - before the parent * gets woken up by child-exit notifications. */ - perf_counter_exit_task(tsk); + perf_event_exit_task(tsk); exit_notify(tsk, group_dead); #ifdef CONFIG_NUMA diff --git a/kernel/fork.c b/kernel/fork.c index bfee931ee3fb..2cebfb23b0b8 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -61,7 +61,7 @@ #include #include #include -#include +#include #include #include @@ -1078,7 +1078,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, /* Perform scheduler related setup. Assign this task to a CPU. */ sched_fork(p, clone_flags); - retval = perf_counter_init_task(p); + retval = perf_event_init_task(p); if (retval) goto bad_fork_cleanup_policy; @@ -1253,7 +1253,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, write_unlock_irq(&tasklist_lock); proc_fork_connector(p); cgroup_post_fork(p); - perf_counter_fork(p); + perf_event_fork(p); return p; bad_fork_free_pid: @@ -1280,7 +1280,7 @@ bad_fork_cleanup_semundo: bad_fork_cleanup_audit: audit_free(p); bad_fork_cleanup_policy: - perf_counter_free_task(p); + perf_event_free_task(p); #ifdef CONFIG_NUMA mpol_put(p->mempolicy); bad_fork_cleanup_cgroup: diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c deleted file mode 100644 index 62de0db8092b..000000000000 --- a/kernel/perf_counter.c +++ /dev/null @@ -1,5000 +0,0 @@ -/* - * Performance counter core code - * - * Copyright (C) 2008 Thomas Gleixner - * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar - * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra - * Copyright © 2009 Paul Mackerras, IBM Corp. - * - * For licensing details see kernel-base/COPYING - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include - -/* - * Each CPU has a list of per CPU counters: - */ -DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); - -int perf_max_counters __read_mostly = 1; -static int perf_reserved_percpu __read_mostly; -static int perf_overcommit __read_mostly = 1; - -static atomic_t nr_counters __read_mostly; -static atomic_t nr_mmap_counters __read_mostly; -static atomic_t nr_comm_counters __read_mostly; -static atomic_t nr_task_counters __read_mostly; - -/* - * perf counter paranoia level: - * -1 - not paranoid at all - * 0 - disallow raw tracepoint access for unpriv - * 1 - disallow cpu counters for unpriv - * 2 - disallow kernel profiling for unpriv - */ -int sysctl_perf_counter_paranoid __read_mostly = 1; - -static inline bool perf_paranoid_tracepoint_raw(void) -{ - return sysctl_perf_counter_paranoid > -1; -} - -static inline bool perf_paranoid_cpu(void) -{ - return sysctl_perf_counter_paranoid > 0; -} - -static inline bool perf_paranoid_kernel(void) -{ - return sysctl_perf_counter_paranoid > 1; -} - -int sysctl_perf_counter_mlock __read_mostly = 512; /* 'free' kb per user */ - -/* - * max perf counter sample rate - */ -int sysctl_perf_counter_sample_rate __read_mostly = 100000; - -static atomic64_t perf_counter_id; - -/* - * Lock for (sysadmin-configurable) counter reservations: - */ -static DEFINE_SPINLOCK(perf_resource_lock); - -/* - * Architecture provided APIs - weak aliases: - */ -extern __weak const struct pmu *hw_perf_counter_init(struct perf_counter *counter) -{ - return NULL; -} - -void __weak hw_perf_disable(void) { barrier(); } -void __weak hw_perf_enable(void) { barrier(); } - -void __weak hw_perf_counter_setup(int cpu) { barrier(); } -void __weak hw_perf_counter_setup_online(int cpu) { barrier(); } - -int __weak -hw_perf_group_sched_in(struct perf_counter *group_leader, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx, int cpu) -{ - return 0; -} - -void __weak perf_counter_print_debug(void) { } - -static DEFINE_PER_CPU(int, perf_disable_count); - -void __perf_disable(void) -{ - __get_cpu_var(perf_disable_count)++; -} - -bool __perf_enable(void) -{ - return !--__get_cpu_var(perf_disable_count); -} - -void perf_disable(void) -{ - __perf_disable(); - hw_perf_disable(); -} - -void perf_enable(void) -{ - if (__perf_enable()) - hw_perf_enable(); -} - -static void get_ctx(struct perf_counter_context *ctx) -{ - WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); -} - -static void free_ctx(struct rcu_head *head) -{ - struct perf_counter_context *ctx; - - ctx = container_of(head, struct perf_counter_context, rcu_head); - kfree(ctx); -} - -static void put_ctx(struct perf_counter_context *ctx) -{ - if (atomic_dec_and_test(&ctx->refcount)) { - if (ctx->parent_ctx) - put_ctx(ctx->parent_ctx); - if (ctx->task) - put_task_struct(ctx->task); - call_rcu(&ctx->rcu_head, free_ctx); - } -} - -static void unclone_ctx(struct perf_counter_context *ctx) -{ - if (ctx->parent_ctx) { - put_ctx(ctx->parent_ctx); - ctx->parent_ctx = NULL; - } -} - -/* - * If we inherit counters we want to return the parent counter id - * to userspace. - */ -static u64 primary_counter_id(struct perf_counter *counter) -{ - u64 id = counter->id; - - if (counter->parent) - id = counter->parent->id; - - return id; -} - -/* - * Get the perf_counter_context for a task and lock it. - * This has to cope with with the fact that until it is locked, - * the context could get moved to another task. - */ -static struct perf_counter_context * -perf_lock_task_context(struct task_struct *task, unsigned long *flags) -{ - struct perf_counter_context *ctx; - - rcu_read_lock(); - retry: - ctx = rcu_dereference(task->perf_counter_ctxp); - if (ctx) { - /* - * If this context is a clone of another, it might - * get swapped for another underneath us by - * perf_counter_task_sched_out, though the - * rcu_read_lock() protects us from any context - * getting freed. Lock the context and check if it - * got swapped before we could get the lock, and retry - * if so. If we locked the right context, then it - * can't get swapped on us any more. - */ - spin_lock_irqsave(&ctx->lock, *flags); - if (ctx != rcu_dereference(task->perf_counter_ctxp)) { - spin_unlock_irqrestore(&ctx->lock, *flags); - goto retry; - } - - if (!atomic_inc_not_zero(&ctx->refcount)) { - spin_unlock_irqrestore(&ctx->lock, *flags); - ctx = NULL; - } - } - rcu_read_unlock(); - return ctx; -} - -/* - * Get the context for a task and increment its pin_count so it - * can't get swapped to another task. This also increments its - * reference count so that the context can't get freed. - */ -static struct perf_counter_context *perf_pin_task_context(struct task_struct *task) -{ - struct perf_counter_context *ctx; - unsigned long flags; - - ctx = perf_lock_task_context(task, &flags); - if (ctx) { - ++ctx->pin_count; - spin_unlock_irqrestore(&ctx->lock, flags); - } - return ctx; -} - -static void perf_unpin_context(struct perf_counter_context *ctx) -{ - unsigned long flags; - - spin_lock_irqsave(&ctx->lock, flags); - --ctx->pin_count; - spin_unlock_irqrestore(&ctx->lock, flags); - put_ctx(ctx); -} - -/* - * Add a counter from the lists for its context. - * Must be called with ctx->mutex and ctx->lock held. - */ -static void -list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx) -{ - struct perf_counter *group_leader = counter->group_leader; - - /* - * Depending on whether it is a standalone or sibling counter, - * add it straight to the context's counter list, or to the group - * leader's sibling list: - */ - if (group_leader == counter) - list_add_tail(&counter->group_entry, &ctx->group_list); - else { - list_add_tail(&counter->group_entry, &group_leader->sibling_list); - group_leader->nr_siblings++; - } - - list_add_rcu(&counter->event_entry, &ctx->event_list); - ctx->nr_counters++; - if (counter->attr.inherit_stat) - ctx->nr_stat++; -} - -/* - * Remove a counter from the lists for its context. - * Must be called with ctx->mutex and ctx->lock held. - */ -static void -list_del_counter(struct perf_counter *counter, struct perf_counter_context *ctx) -{ - struct perf_counter *sibling, *tmp; - - if (list_empty(&counter->group_entry)) - return; - ctx->nr_counters--; - if (counter->attr.inherit_stat) - ctx->nr_stat--; - - list_del_init(&counter->group_entry); - list_del_rcu(&counter->event_entry); - - if (counter->group_leader != counter) - counter->group_leader->nr_siblings--; - - /* - * If this was a group counter with sibling counters then - * upgrade the siblings to singleton counters by adding them - * to the context list directly: - */ - list_for_each_entry_safe(sibling, tmp, &counter->sibling_list, group_entry) { - - list_move_tail(&sibling->group_entry, &ctx->group_list); - sibling->group_leader = sibling; - } -} - -static void -counter_sched_out(struct perf_counter *counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx) -{ - if (counter->state != PERF_COUNTER_STATE_ACTIVE) - return; - - counter->state = PERF_COUNTER_STATE_INACTIVE; - if (counter->pending_disable) { - counter->pending_disable = 0; - counter->state = PERF_COUNTER_STATE_OFF; - } - counter->tstamp_stopped = ctx->time; - counter->pmu->disable(counter); - counter->oncpu = -1; - - if (!is_software_counter(counter)) - cpuctx->active_oncpu--; - ctx->nr_active--; - if (counter->attr.exclusive || !cpuctx->active_oncpu) - cpuctx->exclusive = 0; -} - -static void -group_sched_out(struct perf_counter *group_counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx) -{ - struct perf_counter *counter; - - if (group_counter->state != PERF_COUNTER_STATE_ACTIVE) - return; - - counter_sched_out(group_counter, cpuctx, ctx); - - /* - * Schedule out siblings (if any): - */ - list_for_each_entry(counter, &group_counter->sibling_list, group_entry) - counter_sched_out(counter, cpuctx, ctx); - - if (group_counter->attr.exclusive) - cpuctx->exclusive = 0; -} - -/* - * Cross CPU call to remove a performance counter - * - * We disable the counter on the hardware level first. After that we - * remove it from the context list. - */ -static void __perf_counter_remove_from_context(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter *counter = info; - struct perf_counter_context *ctx = counter->ctx; - - /* - * If this is a task context, we need to check whether it is - * the current task context of this cpu. If not it has been - * scheduled out before the smp call arrived. - */ - if (ctx->task && cpuctx->task_ctx != ctx) - return; - - spin_lock(&ctx->lock); - /* - * Protect the list operation against NMI by disabling the - * counters on a global level. - */ - perf_disable(); - - counter_sched_out(counter, cpuctx, ctx); - - list_del_counter(counter, ctx); - - if (!ctx->task) { - /* - * Allow more per task counters with respect to the - * reservation: - */ - cpuctx->max_pertask = - min(perf_max_counters - ctx->nr_counters, - perf_max_counters - perf_reserved_percpu); - } - - perf_enable(); - spin_unlock(&ctx->lock); -} - - -/* - * Remove the counter from a task's (or a CPU's) list of counters. - * - * Must be called with ctx->mutex held. - * - * CPU counters are removed with a smp call. For task counters we only - * call when the task is on a CPU. - * - * If counter->ctx is a cloned context, callers must make sure that - * every task struct that counter->ctx->task could possibly point to - * remains valid. This is OK when called from perf_release since - * that only calls us on the top-level context, which can't be a clone. - * When called from perf_counter_exit_task, it's OK because the - * context has been detached from its task. - */ -static void perf_counter_remove_from_context(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Per cpu counters are removed via an smp call and - * the removal is always sucessful. - */ - smp_call_function_single(counter->cpu, - __perf_counter_remove_from_context, - counter, 1); - return; - } - -retry: - task_oncpu_function_call(task, __perf_counter_remove_from_context, - counter); - - spin_lock_irq(&ctx->lock); - /* - * If the context is active we need to retry the smp call. - */ - if (ctx->nr_active && !list_empty(&counter->group_entry)) { - spin_unlock_irq(&ctx->lock); - goto retry; - } - - /* - * The lock prevents that this context is scheduled in so we - * can remove the counter safely, if the call above did not - * succeed. - */ - if (!list_empty(&counter->group_entry)) { - list_del_counter(counter, ctx); - } - spin_unlock_irq(&ctx->lock); -} - -static inline u64 perf_clock(void) -{ - return cpu_clock(smp_processor_id()); -} - -/* - * Update the record of the current time in a context. - */ -static void update_context_time(struct perf_counter_context *ctx) -{ - u64 now = perf_clock(); - - ctx->time += now - ctx->timestamp; - ctx->timestamp = now; -} - -/* - * Update the total_time_enabled and total_time_running fields for a counter. - */ -static void update_counter_times(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - u64 run_end; - - if (counter->state < PERF_COUNTER_STATE_INACTIVE || - counter->group_leader->state < PERF_COUNTER_STATE_INACTIVE) - return; - - counter->total_time_enabled = ctx->time - counter->tstamp_enabled; - - if (counter->state == PERF_COUNTER_STATE_INACTIVE) - run_end = counter->tstamp_stopped; - else - run_end = ctx->time; - - counter->total_time_running = run_end - counter->tstamp_running; -} - -/* - * Update total_time_enabled and total_time_running for all counters in a group. - */ -static void update_group_times(struct perf_counter *leader) -{ - struct perf_counter *counter; - - update_counter_times(leader); - list_for_each_entry(counter, &leader->sibling_list, group_entry) - update_counter_times(counter); -} - -/* - * Cross CPU call to disable a performance counter - */ -static void __perf_counter_disable(void *info) -{ - struct perf_counter *counter = info; - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter_context *ctx = counter->ctx; - - /* - * If this is a per-task counter, need to check whether this - * counter's task is the current task on this cpu. - */ - if (ctx->task && cpuctx->task_ctx != ctx) - return; - - spin_lock(&ctx->lock); - - /* - * If the counter is on, turn it off. - * If it is in error state, leave it in error state. - */ - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) { - update_context_time(ctx); - update_group_times(counter); - if (counter == counter->group_leader) - group_sched_out(counter, cpuctx, ctx); - else - counter_sched_out(counter, cpuctx, ctx); - counter->state = PERF_COUNTER_STATE_OFF; - } - - spin_unlock(&ctx->lock); -} - -/* - * Disable a counter. - * - * If counter->ctx is a cloned context, callers must make sure that - * every task struct that counter->ctx->task could possibly point to - * remains valid. This condition is satisifed when called through - * perf_counter_for_each_child or perf_counter_for_each because they - * hold the top-level counter's child_mutex, so any descendant that - * goes to exit will block in sync_child_counter. - * When called from perf_pending_counter it's OK because counter->ctx - * is the current context on this CPU and preemption is disabled, - * hence we can't get into perf_counter_task_sched_out for this context. - */ -static void perf_counter_disable(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Disable the counter on the cpu that it's on - */ - smp_call_function_single(counter->cpu, __perf_counter_disable, - counter, 1); - return; - } - - retry: - task_oncpu_function_call(task, __perf_counter_disable, counter); - - spin_lock_irq(&ctx->lock); - /* - * If the counter is still active, we need to retry the cross-call. - */ - if (counter->state == PERF_COUNTER_STATE_ACTIVE) { - spin_unlock_irq(&ctx->lock); - goto retry; - } - - /* - * Since we have the lock this context can't be scheduled - * in, so we can change the state safely. - */ - if (counter->state == PERF_COUNTER_STATE_INACTIVE) { - update_group_times(counter); - counter->state = PERF_COUNTER_STATE_OFF; - } - - spin_unlock_irq(&ctx->lock); -} - -static int -counter_sched_in(struct perf_counter *counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx, - int cpu) -{ - if (counter->state <= PERF_COUNTER_STATE_OFF) - return 0; - - counter->state = PERF_COUNTER_STATE_ACTIVE; - counter->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ - /* - * The new state must be visible before we turn it on in the hardware: - */ - smp_wmb(); - - if (counter->pmu->enable(counter)) { - counter->state = PERF_COUNTER_STATE_INACTIVE; - counter->oncpu = -1; - return -EAGAIN; - } - - counter->tstamp_running += ctx->time - counter->tstamp_stopped; - - if (!is_software_counter(counter)) - cpuctx->active_oncpu++; - ctx->nr_active++; - - if (counter->attr.exclusive) - cpuctx->exclusive = 1; - - return 0; -} - -static int -group_sched_in(struct perf_counter *group_counter, - struct perf_cpu_context *cpuctx, - struct perf_counter_context *ctx, - int cpu) -{ - struct perf_counter *counter, *partial_group; - int ret; - - if (group_counter->state == PERF_COUNTER_STATE_OFF) - return 0; - - ret = hw_perf_group_sched_in(group_counter, cpuctx, ctx, cpu); - if (ret) - return ret < 0 ? ret : 0; - - if (counter_sched_in(group_counter, cpuctx, ctx, cpu)) - return -EAGAIN; - - /* - * Schedule in siblings as one group (if any): - */ - list_for_each_entry(counter, &group_counter->sibling_list, group_entry) { - if (counter_sched_in(counter, cpuctx, ctx, cpu)) { - partial_group = counter; - goto group_error; - } - } - - return 0; - -group_error: - /* - * Groups can be scheduled in as one unit only, so undo any - * partial group before returning: - */ - list_for_each_entry(counter, &group_counter->sibling_list, group_entry) { - if (counter == partial_group) - break; - counter_sched_out(counter, cpuctx, ctx); - } - counter_sched_out(group_counter, cpuctx, ctx); - - return -EAGAIN; -} - -/* - * Return 1 for a group consisting entirely of software counters, - * 0 if the group contains any hardware counters. - */ -static int is_software_only_group(struct perf_counter *leader) -{ - struct perf_counter *counter; - - if (!is_software_counter(leader)) - return 0; - - list_for_each_entry(counter, &leader->sibling_list, group_entry) - if (!is_software_counter(counter)) - return 0; - - return 1; -} - -/* - * Work out whether we can put this counter group on the CPU now. - */ -static int group_can_go_on(struct perf_counter *counter, - struct perf_cpu_context *cpuctx, - int can_add_hw) -{ - /* - * Groups consisting entirely of software counters can always go on. - */ - if (is_software_only_group(counter)) - return 1; - /* - * If an exclusive group is already on, no other hardware - * counters can go on. - */ - if (cpuctx->exclusive) - return 0; - /* - * If this group is exclusive and there are already - * counters on the CPU, it can't go on. - */ - if (counter->attr.exclusive && cpuctx->active_oncpu) - return 0; - /* - * Otherwise, try to add it if all previous groups were able - * to go on. - */ - return can_add_hw; -} - -static void add_counter_to_ctx(struct perf_counter *counter, - struct perf_counter_context *ctx) -{ - list_add_counter(counter, ctx); - counter->tstamp_enabled = ctx->time; - counter->tstamp_running = ctx->time; - counter->tstamp_stopped = ctx->time; -} - -/* - * Cross CPU call to install and enable a performance counter - * - * Must be called with ctx->mutex held - */ -static void __perf_install_in_context(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter *counter = info; - struct perf_counter_context *ctx = counter->ctx; - struct perf_counter *leader = counter->group_leader; - int cpu = smp_processor_id(); - int err; - - /* - * If this is a task context, we need to check whether it is - * the current task context of this cpu. If not it has been - * scheduled out before the smp call arrived. - * Or possibly this is the right context but it isn't - * on this cpu because it had no counters. - */ - if (ctx->task && cpuctx->task_ctx != ctx) { - if (cpuctx->task_ctx || ctx->task != current) - return; - cpuctx->task_ctx = ctx; - } - - spin_lock(&ctx->lock); - ctx->is_active = 1; - update_context_time(ctx); - - /* - * Protect the list operation against NMI by disabling the - * counters on a global level. NOP for non NMI based counters. - */ - perf_disable(); - - add_counter_to_ctx(counter, ctx); - - /* - * Don't put the counter on if it is disabled or if - * it is in a group and the group isn't on. - */ - if (counter->state != PERF_COUNTER_STATE_INACTIVE || - (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE)) - goto unlock; - - /* - * An exclusive counter can't go on if there are already active - * hardware counters, and no hardware counter can go on if there - * is already an exclusive counter on. - */ - if (!group_can_go_on(counter, cpuctx, 1)) - err = -EEXIST; - else - err = counter_sched_in(counter, cpuctx, ctx, cpu); - - if (err) { - /* - * This counter couldn't go on. If it is in a group - * then we have to pull the whole group off. - * If the counter group is pinned then put it in error state. - */ - if (leader != counter) - group_sched_out(leader, cpuctx, ctx); - if (leader->attr.pinned) { - update_group_times(leader); - leader->state = PERF_COUNTER_STATE_ERROR; - } - } - - if (!err && !ctx->task && cpuctx->max_pertask) - cpuctx->max_pertask--; - - unlock: - perf_enable(); - - spin_unlock(&ctx->lock); -} - -/* - * Attach a performance counter to a context - * - * First we add the counter to the list with the hardware enable bit - * in counter->hw_config cleared. - * - * If the counter is attached to a task which is on a CPU we use a smp - * call to enable it in the task context. The task might have been - * scheduled away, but we check this in the smp call again. - * - * Must be called with ctx->mutex held. - */ -static void -perf_install_in_context(struct perf_counter_context *ctx, - struct perf_counter *counter, - int cpu) -{ - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Per cpu counters are installed via an smp call and - * the install is always sucessful. - */ - smp_call_function_single(cpu, __perf_install_in_context, - counter, 1); - return; - } - -retry: - task_oncpu_function_call(task, __perf_install_in_context, - counter); - - spin_lock_irq(&ctx->lock); - /* - * we need to retry the smp call. - */ - if (ctx->is_active && list_empty(&counter->group_entry)) { - spin_unlock_irq(&ctx->lock); - goto retry; - } - - /* - * The lock prevents that this context is scheduled in so we - * can add the counter safely, if it the call above did not - * succeed. - */ - if (list_empty(&counter->group_entry)) - add_counter_to_ctx(counter, ctx); - spin_unlock_irq(&ctx->lock); -} - -/* - * Put a counter into inactive state and update time fields. - * Enabling the leader of a group effectively enables all - * the group members that aren't explicitly disabled, so we - * have to update their ->tstamp_enabled also. - * Note: this works for group members as well as group leaders - * since the non-leader members' sibling_lists will be empty. - */ -static void __perf_counter_mark_enabled(struct perf_counter *counter, - struct perf_counter_context *ctx) -{ - struct perf_counter *sub; - - counter->state = PERF_COUNTER_STATE_INACTIVE; - counter->tstamp_enabled = ctx->time - counter->total_time_enabled; - list_for_each_entry(sub, &counter->sibling_list, group_entry) - if (sub->state >= PERF_COUNTER_STATE_INACTIVE) - sub->tstamp_enabled = - ctx->time - sub->total_time_enabled; -} - -/* - * Cross CPU call to enable a performance counter - */ -static void __perf_counter_enable(void *info) -{ - struct perf_counter *counter = info; - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter_context *ctx = counter->ctx; - struct perf_counter *leader = counter->group_leader; - int err; - - /* - * If this is a per-task counter, need to check whether this - * counter's task is the current task on this cpu. - */ - if (ctx->task && cpuctx->task_ctx != ctx) { - if (cpuctx->task_ctx || ctx->task != current) - return; - cpuctx->task_ctx = ctx; - } - - spin_lock(&ctx->lock); - ctx->is_active = 1; - update_context_time(ctx); - - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) - goto unlock; - __perf_counter_mark_enabled(counter, ctx); - - /* - * If the counter is in a group and isn't the group leader, - * then don't put it on unless the group is on. - */ - if (leader != counter && leader->state != PERF_COUNTER_STATE_ACTIVE) - goto unlock; - - if (!group_can_go_on(counter, cpuctx, 1)) { - err = -EEXIST; - } else { - perf_disable(); - if (counter == leader) - err = group_sched_in(counter, cpuctx, ctx, - smp_processor_id()); - else - err = counter_sched_in(counter, cpuctx, ctx, - smp_processor_id()); - perf_enable(); - } - - if (err) { - /* - * If this counter can't go on and it's part of a - * group, then the whole group has to come off. - */ - if (leader != counter) - group_sched_out(leader, cpuctx, ctx); - if (leader->attr.pinned) { - update_group_times(leader); - leader->state = PERF_COUNTER_STATE_ERROR; - } - } - - unlock: - spin_unlock(&ctx->lock); -} - -/* - * Enable a counter. - * - * If counter->ctx is a cloned context, callers must make sure that - * every task struct that counter->ctx->task could possibly point to - * remains valid. This condition is satisfied when called through - * perf_counter_for_each_child or perf_counter_for_each as described - * for perf_counter_disable. - */ -static void perf_counter_enable(struct perf_counter *counter) -{ - struct perf_counter_context *ctx = counter->ctx; - struct task_struct *task = ctx->task; - - if (!task) { - /* - * Enable the counter on the cpu that it's on - */ - smp_call_function_single(counter->cpu, __perf_counter_enable, - counter, 1); - return; - } - - spin_lock_irq(&ctx->lock); - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) - goto out; - - /* - * If the counter is in error state, clear that first. - * That way, if we see the counter in error state below, we - * know that it has gone back into error state, as distinct - * from the task having been scheduled away before the - * cross-call arrived. - */ - if (counter->state == PERF_COUNTER_STATE_ERROR) - counter->state = PERF_COUNTER_STATE_OFF; - - retry: - spin_unlock_irq(&ctx->lock); - task_oncpu_function_call(task, __perf_counter_enable, counter); - - spin_lock_irq(&ctx->lock); - - /* - * If the context is active and the counter is still off, - * we need to retry the cross-call. - */ - if (ctx->is_active && counter->state == PERF_COUNTER_STATE_OFF) - goto retry; - - /* - * Since we have the lock this context can't be scheduled - * in, so we can change the state safely. - */ - if (counter->state == PERF_COUNTER_STATE_OFF) - __perf_counter_mark_enabled(counter, ctx); - - out: - spin_unlock_irq(&ctx->lock); -} - -static int perf_counter_refresh(struct perf_counter *counter, int refresh) -{ - /* - * not supported on inherited counters - */ - if (counter->attr.inherit) - return -EINVAL; - - atomic_add(refresh, &counter->event_limit); - perf_counter_enable(counter); - - return 0; -} - -void __perf_counter_sched_out(struct perf_counter_context *ctx, - struct perf_cpu_context *cpuctx) -{ - struct perf_counter *counter; - - spin_lock(&ctx->lock); - ctx->is_active = 0; - if (likely(!ctx->nr_counters)) - goto out; - update_context_time(ctx); - - perf_disable(); - if (ctx->nr_active) { - list_for_each_entry(counter, &ctx->group_list, group_entry) { - if (counter != counter->group_leader) - counter_sched_out(counter, cpuctx, ctx); - else - group_sched_out(counter, cpuctx, ctx); - } - } - perf_enable(); - out: - spin_unlock(&ctx->lock); -} - -/* - * Test whether two contexts are equivalent, i.e. whether they - * have both been cloned from the same version of the same context - * and they both have the same number of enabled counters. - * If the number of enabled counters is the same, then the set - * of enabled counters should be the same, because these are both - * inherited contexts, therefore we can't access individual counters - * in them directly with an fd; we can only enable/disable all - * counters via prctl, or enable/disable all counters in a family - * via ioctl, which will have the same effect on both contexts. - */ -static int context_equiv(struct perf_counter_context *ctx1, - struct perf_counter_context *ctx2) -{ - return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx - && ctx1->parent_gen == ctx2->parent_gen - && !ctx1->pin_count && !ctx2->pin_count; -} - -static void __perf_counter_read(void *counter); - -static void __perf_counter_sync_stat(struct perf_counter *counter, - struct perf_counter *next_counter) -{ - u64 value; - - if (!counter->attr.inherit_stat) - return; - - /* - * Update the counter value, we cannot use perf_counter_read() - * because we're in the middle of a context switch and have IRQs - * disabled, which upsets smp_call_function_single(), however - * we know the counter must be on the current CPU, therefore we - * don't need to use it. - */ - switch (counter->state) { - case PERF_COUNTER_STATE_ACTIVE: - __perf_counter_read(counter); - break; - - case PERF_COUNTER_STATE_INACTIVE: - update_counter_times(counter); - break; - - default: - break; - } - - /* - * In order to keep per-task stats reliable we need to flip the counter - * values when we flip the contexts. - */ - value = atomic64_read(&next_counter->count); - value = atomic64_xchg(&counter->count, value); - atomic64_set(&next_counter->count, value); - - swap(counter->total_time_enabled, next_counter->total_time_enabled); - swap(counter->total_time_running, next_counter->total_time_running); - - /* - * Since we swizzled the values, update the user visible data too. - */ - perf_counter_update_userpage(counter); - perf_counter_update_userpage(next_counter); -} - -#define list_next_entry(pos, member) \ - list_entry(pos->member.next, typeof(*pos), member) - -static void perf_counter_sync_stat(struct perf_counter_context *ctx, - struct perf_counter_context *next_ctx) -{ - struct perf_counter *counter, *next_counter; - - if (!ctx->nr_stat) - return; - - counter = list_first_entry(&ctx->event_list, - struct perf_counter, event_entry); - - next_counter = list_first_entry(&next_ctx->event_list, - struct perf_counter, event_entry); - - while (&counter->event_entry != &ctx->event_list && - &next_counter->event_entry != &next_ctx->event_list) { - - __perf_counter_sync_stat(counter, next_counter); - - counter = list_next_entry(counter, event_entry); - next_counter = list_next_entry(next_counter, event_entry); - } -} - -/* - * Called from scheduler to remove the counters of the current task, - * with interrupts disabled. - * - * We stop each counter and update the counter value in counter->count. - * - * This does not protect us against NMI, but disable() - * sets the disabled bit in the control field of counter _before_ - * accessing the counter control register. If a NMI hits, then it will - * not restart the counter. - */ -void perf_counter_task_sched_out(struct task_struct *task, - struct task_struct *next, int cpu) -{ - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); - struct perf_counter_context *ctx = task->perf_counter_ctxp; - struct perf_counter_context *next_ctx; - struct perf_counter_context *parent; - struct pt_regs *regs; - int do_switch = 1; - - regs = task_pt_regs(task); - perf_swcounter_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0); - - if (likely(!ctx || !cpuctx->task_ctx)) - return; - - update_context_time(ctx); - - rcu_read_lock(); - parent = rcu_dereference(ctx->parent_ctx); - next_ctx = next->perf_counter_ctxp; - if (parent && next_ctx && - rcu_dereference(next_ctx->parent_ctx) == parent) { - /* - * Looks like the two contexts are clones, so we might be - * able to optimize the context switch. We lock both - * contexts and check that they are clones under the - * lock (including re-checking that neither has been - * uncloned in the meantime). It doesn't matter which - * order we take the locks because no other cpu could - * be trying to lock both of these tasks. - */ - spin_lock(&ctx->lock); - spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); - if (context_equiv(ctx, next_ctx)) { - /* - * XXX do we need a memory barrier of sorts - * wrt to rcu_dereference() of perf_counter_ctxp - */ - task->perf_counter_ctxp = next_ctx; - next->perf_counter_ctxp = ctx; - ctx->task = next; - next_ctx->task = task; - do_switch = 0; - - perf_counter_sync_stat(ctx, next_ctx); - } - spin_unlock(&next_ctx->lock); - spin_unlock(&ctx->lock); - } - rcu_read_unlock(); - - if (do_switch) { - __perf_counter_sched_out(ctx, cpuctx); - cpuctx->task_ctx = NULL; - } -} - -/* - * Called with IRQs disabled - */ -static void __perf_counter_task_sched_out(struct perf_counter_context *ctx) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - - if (!cpuctx->task_ctx) - return; - - if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) - return; - - __perf_counter_sched_out(ctx, cpuctx); - cpuctx->task_ctx = NULL; -} - -/* - * Called with IRQs disabled - */ -static void perf_counter_cpu_sched_out(struct perf_cpu_context *cpuctx) -{ - __perf_counter_sched_out(&cpuctx->ctx, cpuctx); -} - -static void -__perf_counter_sched_in(struct perf_counter_context *ctx, - struct perf_cpu_context *cpuctx, int cpu) -{ - struct perf_counter *counter; - int can_add_hw = 1; - - spin_lock(&ctx->lock); - ctx->is_active = 1; - if (likely(!ctx->nr_counters)) - goto out; - - ctx->timestamp = perf_clock(); - - perf_disable(); - - /* - * First go through the list and put on any pinned groups - * in order to give them the best chance of going on. - */ - list_for_each_entry(counter, &ctx->group_list, group_entry) { - if (counter->state <= PERF_COUNTER_STATE_OFF || - !counter->attr.pinned) - continue; - if (counter->cpu != -1 && counter->cpu != cpu) - continue; - - if (counter != counter->group_leader) - counter_sched_in(counter, cpuctx, ctx, cpu); - else { - if (group_can_go_on(counter, cpuctx, 1)) - group_sched_in(counter, cpuctx, ctx, cpu); - } - - /* - * If this pinned group hasn't been scheduled, - * put it in error state. - */ - if (counter->state == PERF_COUNTER_STATE_INACTIVE) { - update_group_times(counter); - counter->state = PERF_COUNTER_STATE_ERROR; - } - } - - list_for_each_entry(counter, &ctx->group_list, group_entry) { - /* - * Ignore counters in OFF or ERROR state, and - * ignore pinned counters since we did them already. - */ - if (counter->state <= PERF_COUNTER_STATE_OFF || - counter->attr.pinned) - continue; - - /* - * Listen to the 'cpu' scheduling filter constraint - * of counters: - */ - if (counter->cpu != -1 && counter->cpu != cpu) - continue; - - if (counter != counter->group_leader) { - if (counter_sched_in(counter, cpuctx, ctx, cpu)) - can_add_hw = 0; - } else { - if (group_can_go_on(counter, cpuctx, can_add_hw)) { - if (group_sched_in(counter, cpuctx, ctx, cpu)) - can_add_hw = 0; - } - } - } - perf_enable(); - out: - spin_unlock(&ctx->lock); -} - -/* - * Called from scheduler to add the counters of the current task - * with interrupts disabled. - * - * We restore the counter value and then enable it. - * - * This does not protect us against NMI, but enable() - * sets the enabled bit in the control field of counter _before_ - * accessing the counter control register. If a NMI hits, then it will - * keep the counter running. - */ -void perf_counter_task_sched_in(struct task_struct *task, int cpu) -{ - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); - struct perf_counter_context *ctx = task->perf_counter_ctxp; - - if (likely(!ctx)) - return; - if (cpuctx->task_ctx == ctx) - return; - __perf_counter_sched_in(ctx, cpuctx, cpu); - cpuctx->task_ctx = ctx; -} - -static void perf_counter_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) -{ - struct perf_counter_context *ctx = &cpuctx->ctx; - - __perf_counter_sched_in(ctx, cpuctx, cpu); -} - -#define MAX_INTERRUPTS (~0ULL) - -static void perf_log_throttle(struct perf_counter *counter, int enable); - -static void perf_adjust_period(struct perf_counter *counter, u64 events) -{ - struct hw_perf_counter *hwc = &counter->hw; - u64 period, sample_period; - s64 delta; - - events *= hwc->sample_period; - period = div64_u64(events, counter->attr.sample_freq); - - delta = (s64)(period - hwc->sample_period); - delta = (delta + 7) / 8; /* low pass filter */ - - sample_period = hwc->sample_period + delta; - - if (!sample_period) - sample_period = 1; - - hwc->sample_period = sample_period; -} - -static void perf_ctx_adjust_freq(struct perf_counter_context *ctx) -{ - struct perf_counter *counter; - struct hw_perf_counter *hwc; - u64 interrupts, freq; - - spin_lock(&ctx->lock); - list_for_each_entry(counter, &ctx->group_list, group_entry) { - if (counter->state != PERF_COUNTER_STATE_ACTIVE) - continue; - - hwc = &counter->hw; - - interrupts = hwc->interrupts; - hwc->interrupts = 0; - - /* - * unthrottle counters on the tick - */ - if (interrupts == MAX_INTERRUPTS) { - perf_log_throttle(counter, 1); - counter->pmu->unthrottle(counter); - interrupts = 2*sysctl_perf_counter_sample_rate/HZ; - } - - if (!counter->attr.freq || !counter->attr.sample_freq) - continue; - - /* - * if the specified freq < HZ then we need to skip ticks - */ - if (counter->attr.sample_freq < HZ) { - freq = counter->attr.sample_freq; - - hwc->freq_count += freq; - hwc->freq_interrupts += interrupts; - - if (hwc->freq_count < HZ) - continue; - - interrupts = hwc->freq_interrupts; - hwc->freq_interrupts = 0; - hwc->freq_count -= HZ; - } else - freq = HZ; - - perf_adjust_period(counter, freq * interrupts); - - /* - * In order to avoid being stalled by an (accidental) huge - * sample period, force reset the sample period if we didn't - * get any events in this freq period. - */ - if (!interrupts) { - perf_disable(); - counter->pmu->disable(counter); - atomic64_set(&hwc->period_left, 0); - counter->pmu->enable(counter); - perf_enable(); - } - } - spin_unlock(&ctx->lock); -} - -/* - * Round-robin a context's counters: - */ -static void rotate_ctx(struct perf_counter_context *ctx) -{ - struct perf_counter *counter; - - if (!ctx->nr_counters) - return; - - spin_lock(&ctx->lock); - /* - * Rotate the first entry last (works just fine for group counters too): - */ - perf_disable(); - list_for_each_entry(counter, &ctx->group_list, group_entry) { - list_move_tail(&counter->group_entry, &ctx->group_list); - break; - } - perf_enable(); - - spin_unlock(&ctx->lock); -} - -void perf_counter_task_tick(struct task_struct *curr, int cpu) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx; - - if (!atomic_read(&nr_counters)) - return; - - cpuctx = &per_cpu(perf_cpu_context, cpu); - ctx = curr->perf_counter_ctxp; - - perf_ctx_adjust_freq(&cpuctx->ctx); - if (ctx) - perf_ctx_adjust_freq(ctx); - - perf_counter_cpu_sched_out(cpuctx); - if (ctx) - __perf_counter_task_sched_out(ctx); - - rotate_ctx(&cpuctx->ctx); - if (ctx) - rotate_ctx(ctx); - - perf_counter_cpu_sched_in(cpuctx, cpu); - if (ctx) - perf_counter_task_sched_in(curr, cpu); -} - -/* - * Enable all of a task's counters that have been marked enable-on-exec. - * This expects task == current. - */ -static void perf_counter_enable_on_exec(struct task_struct *task) -{ - struct perf_counter_context *ctx; - struct perf_counter *counter; - unsigned long flags; - int enabled = 0; - - local_irq_save(flags); - ctx = task->perf_counter_ctxp; - if (!ctx || !ctx->nr_counters) - goto out; - - __perf_counter_task_sched_out(ctx); - - spin_lock(&ctx->lock); - - list_for_each_entry(counter, &ctx->group_list, group_entry) { - if (!counter->attr.enable_on_exec) - continue; - counter->attr.enable_on_exec = 0; - if (counter->state >= PERF_COUNTER_STATE_INACTIVE) - continue; - __perf_counter_mark_enabled(counter, ctx); - enabled = 1; - } - - /* - * Unclone this context if we enabled any counter. - */ - if (enabled) - unclone_ctx(ctx); - - spin_unlock(&ctx->lock); - - perf_counter_task_sched_in(task, smp_processor_id()); - out: - local_irq_restore(flags); -} - -/* - * Cross CPU call to read the hardware counter - */ -static void __perf_counter_read(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter *counter = info; - struct perf_counter_context *ctx = counter->ctx; - unsigned long flags; - - /* - * If this is a task context, we need to check whether it is - * the current task context of this cpu. If not it has been - * scheduled out before the smp call arrived. In that case - * counter->count would have been updated to a recent sample - * when the counter was scheduled out. - */ - if (ctx->task && cpuctx->task_ctx != ctx) - return; - - local_irq_save(flags); - if (ctx->is_active) - update_context_time(ctx); - counter->pmu->read(counter); - update_counter_times(counter); - local_irq_restore(flags); -} - -static u64 perf_counter_read(struct perf_counter *counter) -{ - /* - * If counter is enabled and currently active on a CPU, update the - * value in the counter structure: - */ - if (counter->state == PERF_COUNTER_STATE_ACTIVE) { - smp_call_function_single(counter->oncpu, - __perf_counter_read, counter, 1); - } else if (counter->state == PERF_COUNTER_STATE_INACTIVE) { - update_counter_times(counter); - } - - return atomic64_read(&counter->count); -} - -/* - * Initialize the perf_counter context in a task_struct: - */ -static void -__perf_counter_init_context(struct perf_counter_context *ctx, - struct task_struct *task) -{ - memset(ctx, 0, sizeof(*ctx)); - spin_lock_init(&ctx->lock); - mutex_init(&ctx->mutex); - INIT_LIST_HEAD(&ctx->group_list); - INIT_LIST_HEAD(&ctx->event_list); - atomic_set(&ctx->refcount, 1); - ctx->task = task; -} - -static struct perf_counter_context *find_get_context(pid_t pid, int cpu) -{ - struct perf_counter_context *ctx; - struct perf_cpu_context *cpuctx; - struct task_struct *task; - unsigned long flags; - int err; - - /* - * If cpu is not a wildcard then this is a percpu counter: - */ - if (cpu != -1) { - /* Must be root to operate on a CPU counter: */ - if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) - return ERR_PTR(-EACCES); - - if (cpu < 0 || cpu > num_possible_cpus()) - return ERR_PTR(-EINVAL); - - /* - * We could be clever and allow to attach a counter to an - * offline CPU and activate it when the CPU comes up, but - * that's for later. - */ - if (!cpu_isset(cpu, cpu_online_map)) - return ERR_PTR(-ENODEV); - - cpuctx = &per_cpu(perf_cpu_context, cpu); - ctx = &cpuctx->ctx; - get_ctx(ctx); - - return ctx; - } - - rcu_read_lock(); - if (!pid) - task = current; - else - task = find_task_by_vpid(pid); - if (task) - get_task_struct(task); - rcu_read_unlock(); - - if (!task) - return ERR_PTR(-ESRCH); - - /* - * Can't attach counters to a dying task. - */ - err = -ESRCH; - if (task->flags & PF_EXITING) - goto errout; - - /* Reuse ptrace permission checks for now. */ - err = -EACCES; - if (!ptrace_may_access(task, PTRACE_MODE_READ)) - goto errout; - - retry: - ctx = perf_lock_task_context(task, &flags); - if (ctx) { - unclone_ctx(ctx); - spin_unlock_irqrestore(&ctx->lock, flags); - } - - if (!ctx) { - ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL); - err = -ENOMEM; - if (!ctx) - goto errout; - __perf_counter_init_context(ctx, task); - get_ctx(ctx); - if (cmpxchg(&task->perf_counter_ctxp, NULL, ctx)) { - /* - * We raced with some other task; use - * the context they set. - */ - kfree(ctx); - goto retry; - } - get_task_struct(task); - } - - put_task_struct(task); - return ctx; - - errout: - put_task_struct(task); - return ERR_PTR(err); -} - -static void free_counter_rcu(struct rcu_head *head) -{ - struct perf_counter *counter; - - counter = container_of(head, struct perf_counter, rcu_head); - if (counter->ns) - put_pid_ns(counter->ns); - kfree(counter); -} - -static void perf_pending_sync(struct perf_counter *counter); - -static void free_counter(struct perf_counter *counter) -{ - perf_pending_sync(counter); - - if (!counter->parent) { - atomic_dec(&nr_counters); - if (counter->attr.mmap) - atomic_dec(&nr_mmap_counters); - if (counter->attr.comm) - atomic_dec(&nr_comm_counters); - if (counter->attr.task) - atomic_dec(&nr_task_counters); - } - - if (counter->output) { - fput(counter->output->filp); - counter->output = NULL; - } - - if (counter->destroy) - counter->destroy(counter); - - put_ctx(counter->ctx); - call_rcu(&counter->rcu_head, free_counter_rcu); -} - -/* - * Called when the last reference to the file is gone. - */ -static int perf_release(struct inode *inode, struct file *file) -{ - struct perf_counter *counter = file->private_data; - struct perf_counter_context *ctx = counter->ctx; - - file->private_data = NULL; - - WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - perf_counter_remove_from_context(counter); - mutex_unlock(&ctx->mutex); - - mutex_lock(&counter->owner->perf_counter_mutex); - list_del_init(&counter->owner_entry); - mutex_unlock(&counter->owner->perf_counter_mutex); - put_task_struct(counter->owner); - - free_counter(counter); - - return 0; -} - -static int perf_counter_read_size(struct perf_counter *counter) -{ - int entry = sizeof(u64); /* value */ - int size = 0; - int nr = 1; - - if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) - size += sizeof(u64); - - if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) - size += sizeof(u64); - - if (counter->attr.read_format & PERF_FORMAT_ID) - entry += sizeof(u64); - - if (counter->attr.read_format & PERF_FORMAT_GROUP) { - nr += counter->group_leader->nr_siblings; - size += sizeof(u64); - } - - size += entry * nr; - - return size; -} - -static u64 perf_counter_read_value(struct perf_counter *counter) -{ - struct perf_counter *child; - u64 total = 0; - - total += perf_counter_read(counter); - list_for_each_entry(child, &counter->child_list, child_list) - total += perf_counter_read(child); - - return total; -} - -static int perf_counter_read_entry(struct perf_counter *counter, - u64 read_format, char __user *buf) -{ - int n = 0, count = 0; - u64 values[2]; - - values[n++] = perf_counter_read_value(counter); - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(counter); - - count = n * sizeof(u64); - - if (copy_to_user(buf, values, count)) - return -EFAULT; - - return count; -} - -static int perf_counter_read_group(struct perf_counter *counter, - u64 read_format, char __user *buf) -{ - struct perf_counter *leader = counter->group_leader, *sub; - int n = 0, size = 0, err = -EFAULT; - u64 values[3]; - - values[n++] = 1 + leader->nr_siblings; - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { - values[n++] = leader->total_time_enabled + - atomic64_read(&leader->child_total_time_enabled); - } - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { - values[n++] = leader->total_time_running + - atomic64_read(&leader->child_total_time_running); - } - - size = n * sizeof(u64); - - if (copy_to_user(buf, values, size)) - return -EFAULT; - - err = perf_counter_read_entry(leader, read_format, buf + size); - if (err < 0) - return err; - - size += err; - - list_for_each_entry(sub, &leader->sibling_list, group_entry) { - err = perf_counter_read_entry(sub, read_format, - buf + size); - if (err < 0) - return err; - - size += err; - } - - return size; -} - -static int perf_counter_read_one(struct perf_counter *counter, - u64 read_format, char __user *buf) -{ - u64 values[4]; - int n = 0; - - values[n++] = perf_counter_read_value(counter); - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { - values[n++] = counter->total_time_enabled + - atomic64_read(&counter->child_total_time_enabled); - } - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { - values[n++] = counter->total_time_running + - atomic64_read(&counter->child_total_time_running); - } - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(counter); - - if (copy_to_user(buf, values, n * sizeof(u64))) - return -EFAULT; - - return n * sizeof(u64); -} - -/* - * Read the performance counter - simple non blocking version for now - */ -static ssize_t -perf_read_hw(struct perf_counter *counter, char __user *buf, size_t count) -{ - u64 read_format = counter->attr.read_format; - int ret; - - /* - * Return end-of-file for a read on a counter that is in - * error state (i.e. because it was pinned but it couldn't be - * scheduled on to the CPU at some point). - */ - if (counter->state == PERF_COUNTER_STATE_ERROR) - return 0; - - if (count < perf_counter_read_size(counter)) - return -ENOSPC; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - mutex_lock(&counter->child_mutex); - if (read_format & PERF_FORMAT_GROUP) - ret = perf_counter_read_group(counter, read_format, buf); - else - ret = perf_counter_read_one(counter, read_format, buf); - mutex_unlock(&counter->child_mutex); - - return ret; -} - -static ssize_t -perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) -{ - struct perf_counter *counter = file->private_data; - - return perf_read_hw(counter, buf, count); -} - -static unsigned int perf_poll(struct file *file, poll_table *wait) -{ - struct perf_counter *counter = file->private_data; - struct perf_mmap_data *data; - unsigned int events = POLL_HUP; - - rcu_read_lock(); - data = rcu_dereference(counter->data); - if (data) - events = atomic_xchg(&data->poll, 0); - rcu_read_unlock(); - - poll_wait(file, &counter->waitq, wait); - - return events; -} - -static void perf_counter_reset(struct perf_counter *counter) -{ - (void)perf_counter_read(counter); - atomic64_set(&counter->count, 0); - perf_counter_update_userpage(counter); -} - -/* - * Holding the top-level counter's child_mutex means that any - * descendant process that has inherited this counter will block - * in sync_child_counter if it goes to exit, thus satisfying the - * task existence requirements of perf_counter_enable/disable. - */ -static void perf_counter_for_each_child(struct perf_counter *counter, - void (*func)(struct perf_counter *)) -{ - struct perf_counter *child; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - mutex_lock(&counter->child_mutex); - func(counter); - list_for_each_entry(child, &counter->child_list, child_list) - func(child); - mutex_unlock(&counter->child_mutex); -} - -static void perf_counter_for_each(struct perf_counter *counter, - void (*func)(struct perf_counter *)) -{ - struct perf_counter_context *ctx = counter->ctx; - struct perf_counter *sibling; - - WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - counter = counter->group_leader; - - perf_counter_for_each_child(counter, func); - func(counter); - list_for_each_entry(sibling, &counter->sibling_list, group_entry) - perf_counter_for_each_child(counter, func); - mutex_unlock(&ctx->mutex); -} - -static int perf_counter_period(struct perf_counter *counter, u64 __user *arg) -{ - struct perf_counter_context *ctx = counter->ctx; - unsigned long size; - int ret = 0; - u64 value; - - if (!counter->attr.sample_period) - return -EINVAL; - - size = copy_from_user(&value, arg, sizeof(value)); - if (size != sizeof(value)) - return -EFAULT; - - if (!value) - return -EINVAL; - - spin_lock_irq(&ctx->lock); - if (counter->attr.freq) { - if (value > sysctl_perf_counter_sample_rate) { - ret = -EINVAL; - goto unlock; - } - - counter->attr.sample_freq = value; - } else { - counter->attr.sample_period = value; - counter->hw.sample_period = value; - } -unlock: - spin_unlock_irq(&ctx->lock); - - return ret; -} - -int perf_counter_set_output(struct perf_counter *counter, int output_fd); - -static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) -{ - struct perf_counter *counter = file->private_data; - void (*func)(struct perf_counter *); - u32 flags = arg; - - switch (cmd) { - case PERF_COUNTER_IOC_ENABLE: - func = perf_counter_enable; - break; - case PERF_COUNTER_IOC_DISABLE: - func = perf_counter_disable; - break; - case PERF_COUNTER_IOC_RESET: - func = perf_counter_reset; - break; - - case PERF_COUNTER_IOC_REFRESH: - return perf_counter_refresh(counter, arg); - - case PERF_COUNTER_IOC_PERIOD: - return perf_counter_period(counter, (u64 __user *)arg); - - case PERF_COUNTER_IOC_SET_OUTPUT: - return perf_counter_set_output(counter, arg); - - default: - return -ENOTTY; - } - - if (flags & PERF_IOC_FLAG_GROUP) - perf_counter_for_each(counter, func); - else - perf_counter_for_each_child(counter, func); - - return 0; -} - -int perf_counter_task_enable(void) -{ - struct perf_counter *counter; - - mutex_lock(¤t->perf_counter_mutex); - list_for_each_entry(counter, ¤t->perf_counter_list, owner_entry) - perf_counter_for_each_child(counter, perf_counter_enable); - mutex_unlock(¤t->perf_counter_mutex); - - return 0; -} - -int perf_counter_task_disable(void) -{ - struct perf_counter *counter; - - mutex_lock(¤t->perf_counter_mutex); - list_for_each_entry(counter, ¤t->perf_counter_list, owner_entry) - perf_counter_for_each_child(counter, perf_counter_disable); - mutex_unlock(¤t->perf_counter_mutex); - - return 0; -} - -#ifndef PERF_COUNTER_INDEX_OFFSET -# define PERF_COUNTER_INDEX_OFFSET 0 -#endif - -static int perf_counter_index(struct perf_counter *counter) -{ - if (counter->state != PERF_COUNTER_STATE_ACTIVE) - return 0; - - return counter->hw.idx + 1 - PERF_COUNTER_INDEX_OFFSET; -} - -/* - * Callers need to ensure there can be no nesting of this function, otherwise - * the seqlock logic goes bad. We can not serialize this because the arch - * code calls this from NMI context. - */ -void perf_counter_update_userpage(struct perf_counter *counter) -{ - struct perf_counter_mmap_page *userpg; - struct perf_mmap_data *data; - - rcu_read_lock(); - data = rcu_dereference(counter->data); - if (!data) - goto unlock; - - userpg = data->user_page; - - /* - * Disable preemption so as to not let the corresponding user-space - * spin too long if we get preempted. - */ - preempt_disable(); - ++userpg->lock; - barrier(); - userpg->index = perf_counter_index(counter); - userpg->offset = atomic64_read(&counter->count); - if (counter->state == PERF_COUNTER_STATE_ACTIVE) - userpg->offset -= atomic64_read(&counter->hw.prev_count); - - userpg->time_enabled = counter->total_time_enabled + - atomic64_read(&counter->child_total_time_enabled); - - userpg->time_running = counter->total_time_running + - atomic64_read(&counter->child_total_time_running); - - barrier(); - ++userpg->lock; - preempt_enable(); -unlock: - rcu_read_unlock(); -} - -static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) -{ - struct perf_counter *counter = vma->vm_file->private_data; - struct perf_mmap_data *data; - int ret = VM_FAULT_SIGBUS; - - if (vmf->flags & FAULT_FLAG_MKWRITE) { - if (vmf->pgoff == 0) - ret = 0; - return ret; - } - - rcu_read_lock(); - data = rcu_dereference(counter->data); - if (!data) - goto unlock; - - if (vmf->pgoff == 0) { - vmf->page = virt_to_page(data->user_page); - } else { - int nr = vmf->pgoff - 1; - - if ((unsigned)nr > data->nr_pages) - goto unlock; - - if (vmf->flags & FAULT_FLAG_WRITE) - goto unlock; - - vmf->page = virt_to_page(data->data_pages[nr]); - } - - get_page(vmf->page); - vmf->page->mapping = vma->vm_file->f_mapping; - vmf->page->index = vmf->pgoff; - - ret = 0; -unlock: - rcu_read_unlock(); - - return ret; -} - -static int perf_mmap_data_alloc(struct perf_counter *counter, int nr_pages) -{ - struct perf_mmap_data *data; - unsigned long size; - int i; - - WARN_ON(atomic_read(&counter->mmap_count)); - - size = sizeof(struct perf_mmap_data); - size += nr_pages * sizeof(void *); - - data = kzalloc(size, GFP_KERNEL); - if (!data) - goto fail; - - data->user_page = (void *)get_zeroed_page(GFP_KERNEL); - if (!data->user_page) - goto fail_user_page; - - for (i = 0; i < nr_pages; i++) { - data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL); - if (!data->data_pages[i]) - goto fail_data_pages; - } - - data->nr_pages = nr_pages; - atomic_set(&data->lock, -1); - - if (counter->attr.watermark) { - data->watermark = min_t(long, PAGE_SIZE * nr_pages, - counter->attr.wakeup_watermark); - } - if (!data->watermark) - data->watermark = max(PAGE_SIZE, PAGE_SIZE * nr_pages / 4); - - rcu_assign_pointer(counter->data, data); - - return 0; - -fail_data_pages: - for (i--; i >= 0; i--) - free_page((unsigned long)data->data_pages[i]); - - free_page((unsigned long)data->user_page); - -fail_user_page: - kfree(data); - -fail: - return -ENOMEM; -} - -static void perf_mmap_free_page(unsigned long addr) -{ - struct page *page = virt_to_page((void *)addr); - - page->mapping = NULL; - __free_page(page); -} - -static void __perf_mmap_data_free(struct rcu_head *rcu_head) -{ - struct perf_mmap_data *data; - int i; - - data = container_of(rcu_head, struct perf_mmap_data, rcu_head); - - perf_mmap_free_page((unsigned long)data->user_page); - for (i = 0; i < data->nr_pages; i++) - perf_mmap_free_page((unsigned long)data->data_pages[i]); - - kfree(data); -} - -static void perf_mmap_data_free(struct perf_counter *counter) -{ - struct perf_mmap_data *data = counter->data; - - WARN_ON(atomic_read(&counter->mmap_count)); - - rcu_assign_pointer(counter->data, NULL); - call_rcu(&data->rcu_head, __perf_mmap_data_free); -} - -static void perf_mmap_open(struct vm_area_struct *vma) -{ - struct perf_counter *counter = vma->vm_file->private_data; - - atomic_inc(&counter->mmap_count); -} - -static void perf_mmap_close(struct vm_area_struct *vma) -{ - struct perf_counter *counter = vma->vm_file->private_data; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - if (atomic_dec_and_mutex_lock(&counter->mmap_count, &counter->mmap_mutex)) { - struct user_struct *user = current_user(); - - atomic_long_sub(counter->data->nr_pages + 1, &user->locked_vm); - vma->vm_mm->locked_vm -= counter->data->nr_locked; - perf_mmap_data_free(counter); - mutex_unlock(&counter->mmap_mutex); - } -} - -static struct vm_operations_struct perf_mmap_vmops = { - .open = perf_mmap_open, - .close = perf_mmap_close, - .fault = perf_mmap_fault, - .page_mkwrite = perf_mmap_fault, -}; - -static int perf_mmap(struct file *file, struct vm_area_struct *vma) -{ - struct perf_counter *counter = file->private_data; - unsigned long user_locked, user_lock_limit; - struct user_struct *user = current_user(); - unsigned long locked, lock_limit; - unsigned long vma_size; - unsigned long nr_pages; - long user_extra, extra; - int ret = 0; - - if (!(vma->vm_flags & VM_SHARED)) - return -EINVAL; - - vma_size = vma->vm_end - vma->vm_start; - nr_pages = (vma_size / PAGE_SIZE) - 1; - - /* - * If we have data pages ensure they're a power-of-two number, so we - * can do bitmasks instead of modulo. - */ - if (nr_pages != 0 && !is_power_of_2(nr_pages)) - return -EINVAL; - - if (vma_size != PAGE_SIZE * (1 + nr_pages)) - return -EINVAL; - - if (vma->vm_pgoff != 0) - return -EINVAL; - - WARN_ON_ONCE(counter->ctx->parent_ctx); - mutex_lock(&counter->mmap_mutex); - if (counter->output) { - ret = -EINVAL; - goto unlock; - } - - if (atomic_inc_not_zero(&counter->mmap_count)) { - if (nr_pages != counter->data->nr_pages) - ret = -EINVAL; - goto unlock; - } - - user_extra = nr_pages + 1; - user_lock_limit = sysctl_perf_counter_mlock >> (PAGE_SHIFT - 10); - - /* - * Increase the limit linearly with more CPUs: - */ - user_lock_limit *= num_online_cpus(); - - user_locked = atomic_long_read(&user->locked_vm) + user_extra; - - extra = 0; - if (user_locked > user_lock_limit) - extra = user_locked - user_lock_limit; - - lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; - lock_limit >>= PAGE_SHIFT; - locked = vma->vm_mm->locked_vm + extra; - - if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && - !capable(CAP_IPC_LOCK)) { - ret = -EPERM; - goto unlock; - } - - WARN_ON(counter->data); - ret = perf_mmap_data_alloc(counter, nr_pages); - if (ret) - goto unlock; - - atomic_set(&counter->mmap_count, 1); - atomic_long_add(user_extra, &user->locked_vm); - vma->vm_mm->locked_vm += extra; - counter->data->nr_locked = extra; - if (vma->vm_flags & VM_WRITE) - counter->data->writable = 1; - -unlock: - mutex_unlock(&counter->mmap_mutex); - - vma->vm_flags |= VM_RESERVED; - vma->vm_ops = &perf_mmap_vmops; - - return ret; -} - -static int perf_fasync(int fd, struct file *filp, int on) -{ - struct inode *inode = filp->f_path.dentry->d_inode; - struct perf_counter *counter = filp->private_data; - int retval; - - mutex_lock(&inode->i_mutex); - retval = fasync_helper(fd, filp, on, &counter->fasync); - mutex_unlock(&inode->i_mutex); - - if (retval < 0) - return retval; - - return 0; -} - -static const struct file_operations perf_fops = { - .release = perf_release, - .read = perf_read, - .poll = perf_poll, - .unlocked_ioctl = perf_ioctl, - .compat_ioctl = perf_ioctl, - .mmap = perf_mmap, - .fasync = perf_fasync, -}; - -/* - * Perf counter wakeup - * - * If there's data, ensure we set the poll() state and publish everything - * to user-space before waking everybody up. - */ - -void perf_counter_wakeup(struct perf_counter *counter) -{ - wake_up_all(&counter->waitq); - - if (counter->pending_kill) { - kill_fasync(&counter->fasync, SIGIO, counter->pending_kill); - counter->pending_kill = 0; - } -} - -/* - * Pending wakeups - * - * Handle the case where we need to wakeup up from NMI (or rq->lock) context. - * - * The NMI bit means we cannot possibly take locks. Therefore, maintain a - * single linked list and use cmpxchg() to add entries lockless. - */ - -static void perf_pending_counter(struct perf_pending_entry *entry) -{ - struct perf_counter *counter = container_of(entry, - struct perf_counter, pending); - - if (counter->pending_disable) { - counter->pending_disable = 0; - __perf_counter_disable(counter); - } - - if (counter->pending_wakeup) { - counter->pending_wakeup = 0; - perf_counter_wakeup(counter); - } -} - -#define PENDING_TAIL ((struct perf_pending_entry *)-1UL) - -static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = { - PENDING_TAIL, -}; - -static void perf_pending_queue(struct perf_pending_entry *entry, - void (*func)(struct perf_pending_entry *)) -{ - struct perf_pending_entry **head; - - if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL) - return; - - entry->func = func; - - head = &get_cpu_var(perf_pending_head); - - do { - entry->next = *head; - } while (cmpxchg(head, entry->next, entry) != entry->next); - - set_perf_counter_pending(); - - put_cpu_var(perf_pending_head); -} - -static int __perf_pending_run(void) -{ - struct perf_pending_entry *list; - int nr = 0; - - list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL); - while (list != PENDING_TAIL) { - void (*func)(struct perf_pending_entry *); - struct perf_pending_entry *entry = list; - - list = list->next; - - func = entry->func; - entry->next = NULL; - /* - * Ensure we observe the unqueue before we issue the wakeup, - * so that we won't be waiting forever. - * -- see perf_not_pending(). - */ - smp_wmb(); - - func(entry); - nr++; - } - - return nr; -} - -static inline int perf_not_pending(struct perf_counter *counter) -{ - /* - * If we flush on whatever cpu we run, there is a chance we don't - * need to wait. - */ - get_cpu(); - __perf_pending_run(); - put_cpu(); - - /* - * Ensure we see the proper queue state before going to sleep - * so that we do not miss the wakeup. -- see perf_pending_handle() - */ - smp_rmb(); - return counter->pending.next == NULL; -} - -static void perf_pending_sync(struct perf_counter *counter) -{ - wait_event(counter->waitq, perf_not_pending(counter)); -} - -void perf_counter_do_pending(void) -{ - __perf_pending_run(); -} - -/* - * Callchain support -- arch specific - */ - -__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) -{ - return NULL; -} - -/* - * Output - */ -static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail, - unsigned long offset, unsigned long head) -{ - unsigned long mask; - - if (!data->writable) - return true; - - mask = (data->nr_pages << PAGE_SHIFT) - 1; - - offset = (offset - tail) & mask; - head = (head - tail) & mask; - - if ((int)(head - offset) < 0) - return false; - - return true; -} - -static void perf_output_wakeup(struct perf_output_handle *handle) -{ - atomic_set(&handle->data->poll, POLL_IN); - - if (handle->nmi) { - handle->counter->pending_wakeup = 1; - perf_pending_queue(&handle->counter->pending, - perf_pending_counter); - } else - perf_counter_wakeup(handle->counter); -} - -/* - * Curious locking construct. - * - * We need to ensure a later event doesn't publish a head when a former - * event isn't done writing. However since we need to deal with NMIs we - * cannot fully serialize things. - * - * What we do is serialize between CPUs so we only have to deal with NMI - * nesting on a single CPU. - * - * We only publish the head (and generate a wakeup) when the outer-most - * event completes. - */ -static void perf_output_lock(struct perf_output_handle *handle) -{ - struct perf_mmap_data *data = handle->data; - int cpu; - - handle->locked = 0; - - local_irq_save(handle->flags); - cpu = smp_processor_id(); - - if (in_nmi() && atomic_read(&data->lock) == cpu) - return; - - while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) - cpu_relax(); - - handle->locked = 1; -} - -static void perf_output_unlock(struct perf_output_handle *handle) -{ - struct perf_mmap_data *data = handle->data; - unsigned long head; - int cpu; - - data->done_head = data->head; - - if (!handle->locked) - goto out; - -again: - /* - * The xchg implies a full barrier that ensures all writes are done - * before we publish the new head, matched by a rmb() in userspace when - * reading this position. - */ - while ((head = atomic_long_xchg(&data->done_head, 0))) - data->user_page->data_head = head; - - /* - * NMI can happen here, which means we can miss a done_head update. - */ - - cpu = atomic_xchg(&data->lock, -1); - WARN_ON_ONCE(cpu != smp_processor_id()); - - /* - * Therefore we have to validate we did not indeed do so. - */ - if (unlikely(atomic_long_read(&data->done_head))) { - /* - * Since we had it locked, we can lock it again. - */ - while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) - cpu_relax(); - - goto again; - } - - if (atomic_xchg(&data->wakeup, 0)) - perf_output_wakeup(handle); -out: - local_irq_restore(handle->flags); -} - -void perf_output_copy(struct perf_output_handle *handle, - const void *buf, unsigned int len) -{ - unsigned int pages_mask; - unsigned int offset; - unsigned int size; - void **pages; - - offset = handle->offset; - pages_mask = handle->data->nr_pages - 1; - pages = handle->data->data_pages; - - do { - unsigned int page_offset; - int nr; - - nr = (offset >> PAGE_SHIFT) & pages_mask; - page_offset = offset & (PAGE_SIZE - 1); - size = min_t(unsigned int, PAGE_SIZE - page_offset, len); - - memcpy(pages[nr] + page_offset, buf, size); - - len -= size; - buf += size; - offset += size; - } while (len); - - handle->offset = offset; - - /* - * Check we didn't copy past our reservation window, taking the - * possible unsigned int wrap into account. - */ - WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0); -} - -int perf_output_begin(struct perf_output_handle *handle, - struct perf_counter *counter, unsigned int size, - int nmi, int sample) -{ - struct perf_counter *output_counter; - struct perf_mmap_data *data; - unsigned long tail, offset, head; - int have_lost; - struct { - struct perf_event_header header; - u64 id; - u64 lost; - } lost_event; - - rcu_read_lock(); - /* - * For inherited counters we send all the output towards the parent. - */ - if (counter->parent) - counter = counter->parent; - - output_counter = rcu_dereference(counter->output); - if (output_counter) - counter = output_counter; - - data = rcu_dereference(counter->data); - if (!data) - goto out; - - handle->data = data; - handle->counter = counter; - handle->nmi = nmi; - handle->sample = sample; - - if (!data->nr_pages) - goto fail; - - have_lost = atomic_read(&data->lost); - if (have_lost) - size += sizeof(lost_event); - - perf_output_lock(handle); - - do { - /* - * Userspace could choose to issue a mb() before updating the - * tail pointer. So that all reads will be completed before the - * write is issued. - */ - tail = ACCESS_ONCE(data->user_page->data_tail); - smp_rmb(); - offset = head = atomic_long_read(&data->head); - head += size; - if (unlikely(!perf_output_space(data, tail, offset, head))) - goto fail; - } while (atomic_long_cmpxchg(&data->head, offset, head) != offset); - - handle->offset = offset; - handle->head = head; - - if (head - tail > data->watermark) - atomic_set(&data->wakeup, 1); - - if (have_lost) { - lost_event.header.type = PERF_EVENT_LOST; - lost_event.header.misc = 0; - lost_event.header.size = sizeof(lost_event); - lost_event.id = counter->id; - lost_event.lost = atomic_xchg(&data->lost, 0); - - perf_output_put(handle, lost_event); - } - - return 0; - -fail: - atomic_inc(&data->lost); - perf_output_unlock(handle); -out: - rcu_read_unlock(); - - return -ENOSPC; -} - -void perf_output_end(struct perf_output_handle *handle) -{ - struct perf_counter *counter = handle->counter; - struct perf_mmap_data *data = handle->data; - - int wakeup_events = counter->attr.wakeup_events; - - if (handle->sample && wakeup_events) { - int events = atomic_inc_return(&data->events); - if (events >= wakeup_events) { - atomic_sub(wakeup_events, &data->events); - atomic_set(&data->wakeup, 1); - } - } - - perf_output_unlock(handle); - rcu_read_unlock(); -} - -static u32 perf_counter_pid(struct perf_counter *counter, struct task_struct *p) -{ - /* - * only top level counters have the pid namespace they were created in - */ - if (counter->parent) - counter = counter->parent; - - return task_tgid_nr_ns(p, counter->ns); -} - -static u32 perf_counter_tid(struct perf_counter *counter, struct task_struct *p) -{ - /* - * only top level counters have the pid namespace they were created in - */ - if (counter->parent) - counter = counter->parent; - - return task_pid_nr_ns(p, counter->ns); -} - -static void perf_output_read_one(struct perf_output_handle *handle, - struct perf_counter *counter) -{ - u64 read_format = counter->attr.read_format; - u64 values[4]; - int n = 0; - - values[n++] = atomic64_read(&counter->count); - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { - values[n++] = counter->total_time_enabled + - atomic64_read(&counter->child_total_time_enabled); - } - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { - values[n++] = counter->total_time_running + - atomic64_read(&counter->child_total_time_running); - } - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(counter); - - perf_output_copy(handle, values, n * sizeof(u64)); -} - -/* - * XXX PERF_FORMAT_GROUP vs inherited counters seems difficult. - */ -static void perf_output_read_group(struct perf_output_handle *handle, - struct perf_counter *counter) -{ - struct perf_counter *leader = counter->group_leader, *sub; - u64 read_format = counter->attr.read_format; - u64 values[5]; - int n = 0; - - values[n++] = 1 + leader->nr_siblings; - - if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) - values[n++] = leader->total_time_enabled; - - if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) - values[n++] = leader->total_time_running; - - if (leader != counter) - leader->pmu->read(leader); - - values[n++] = atomic64_read(&leader->count); - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(leader); - - perf_output_copy(handle, values, n * sizeof(u64)); - - list_for_each_entry(sub, &leader->sibling_list, group_entry) { - n = 0; - - if (sub != counter) - sub->pmu->read(sub); - - values[n++] = atomic64_read(&sub->count); - if (read_format & PERF_FORMAT_ID) - values[n++] = primary_counter_id(sub); - - perf_output_copy(handle, values, n * sizeof(u64)); - } -} - -static void perf_output_read(struct perf_output_handle *handle, - struct perf_counter *counter) -{ - if (counter->attr.read_format & PERF_FORMAT_GROUP) - perf_output_read_group(handle, counter); - else - perf_output_read_one(handle, counter); -} - -void perf_output_sample(struct perf_output_handle *handle, - struct perf_event_header *header, - struct perf_sample_data *data, - struct perf_counter *counter) -{ - u64 sample_type = data->type; - - perf_output_put(handle, *header); - - if (sample_type & PERF_SAMPLE_IP) - perf_output_put(handle, data->ip); - - if (sample_type & PERF_SAMPLE_TID) - perf_output_put(handle, data->tid_entry); - - if (sample_type & PERF_SAMPLE_TIME) - perf_output_put(handle, data->time); - - if (sample_type & PERF_SAMPLE_ADDR) - perf_output_put(handle, data->addr); - - if (sample_type & PERF_SAMPLE_ID) - perf_output_put(handle, data->id); - - if (sample_type & PERF_SAMPLE_STREAM_ID) - perf_output_put(handle, data->stream_id); - - if (sample_type & PERF_SAMPLE_CPU) - perf_output_put(handle, data->cpu_entry); - - if (sample_type & PERF_SAMPLE_PERIOD) - perf_output_put(handle, data->period); - - if (sample_type & PERF_SAMPLE_READ) - perf_output_read(handle, counter); - - if (sample_type & PERF_SAMPLE_CALLCHAIN) { - if (data->callchain) { - int size = 1; - - if (data->callchain) - size += data->callchain->nr; - - size *= sizeof(u64); - - perf_output_copy(handle, data->callchain, size); - } else { - u64 nr = 0; - perf_output_put(handle, nr); - } - } - - if (sample_type & PERF_SAMPLE_RAW) { - if (data->raw) { - perf_output_put(handle, data->raw->size); - perf_output_copy(handle, data->raw->data, - data->raw->size); - } else { - struct { - u32 size; - u32 data; - } raw = { - .size = sizeof(u32), - .data = 0, - }; - perf_output_put(handle, raw); - } - } -} - -void perf_prepare_sample(struct perf_event_header *header, - struct perf_sample_data *data, - struct perf_counter *counter, - struct pt_regs *regs) -{ - u64 sample_type = counter->attr.sample_type; - - data->type = sample_type; - - header->type = PERF_EVENT_SAMPLE; - header->size = sizeof(*header); - - header->misc = 0; - header->misc |= perf_misc_flags(regs); - - if (sample_type & PERF_SAMPLE_IP) { - data->ip = perf_instruction_pointer(regs); - - header->size += sizeof(data->ip); - } - - if (sample_type & PERF_SAMPLE_TID) { - /* namespace issues */ - data->tid_entry.pid = perf_counter_pid(counter, current); - data->tid_entry.tid = perf_counter_tid(counter, current); - - header->size += sizeof(data->tid_entry); - } - - if (sample_type & PERF_SAMPLE_TIME) { - data->time = perf_clock(); - - header->size += sizeof(data->time); - } - - if (sample_type & PERF_SAMPLE_ADDR) - header->size += sizeof(data->addr); - - if (sample_type & PERF_SAMPLE_ID) { - data->id = primary_counter_id(counter); - - header->size += sizeof(data->id); - } - - if (sample_type & PERF_SAMPLE_STREAM_ID) { - data->stream_id = counter->id; - - header->size += sizeof(data->stream_id); - } - - if (sample_type & PERF_SAMPLE_CPU) { - data->cpu_entry.cpu = raw_smp_processor_id(); - data->cpu_entry.reserved = 0; - - header->size += sizeof(data->cpu_entry); - } - - if (sample_type & PERF_SAMPLE_PERIOD) - header->size += sizeof(data->period); - - if (sample_type & PERF_SAMPLE_READ) - header->size += perf_counter_read_size(counter); - - if (sample_type & PERF_SAMPLE_CALLCHAIN) { - int size = 1; - - data->callchain = perf_callchain(regs); - - if (data->callchain) - size += data->callchain->nr; - - header->size += size * sizeof(u64); - } - - if (sample_type & PERF_SAMPLE_RAW) { - int size = sizeof(u32); - - if (data->raw) - size += data->raw->size; - else - size += sizeof(u32); - - WARN_ON_ONCE(size & (sizeof(u64)-1)); - header->size += size; - } -} - -static void perf_counter_output(struct perf_counter *counter, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct perf_output_handle handle; - struct perf_event_header header; - - perf_prepare_sample(&header, data, counter, regs); - - if (perf_output_begin(&handle, counter, header.size, nmi, 1)) - return; - - perf_output_sample(&handle, &header, data, counter); - - perf_output_end(&handle); -} - -/* - * read event - */ - -struct perf_read_event { - struct perf_event_header header; - - u32 pid; - u32 tid; -}; - -static void -perf_counter_read_event(struct perf_counter *counter, - struct task_struct *task) -{ - struct perf_output_handle handle; - struct perf_read_event read_event = { - .header = { - .type = PERF_EVENT_READ, - .misc = 0, - .size = sizeof(read_event) + perf_counter_read_size(counter), - }, - .pid = perf_counter_pid(counter, task), - .tid = perf_counter_tid(counter, task), - }; - int ret; - - ret = perf_output_begin(&handle, counter, read_event.header.size, 0, 0); - if (ret) - return; - - perf_output_put(&handle, read_event); - perf_output_read(&handle, counter); - - perf_output_end(&handle); -} - -/* - * task tracking -- fork/exit - * - * enabled by: attr.comm | attr.mmap | attr.task - */ - -struct perf_task_event { - struct task_struct *task; - struct perf_counter_context *task_ctx; - - struct { - struct perf_event_header header; - - u32 pid; - u32 ppid; - u32 tid; - u32 ptid; - u64 time; - } event; -}; - -static void perf_counter_task_output(struct perf_counter *counter, - struct perf_task_event *task_event) -{ - struct perf_output_handle handle; - int size; - struct task_struct *task = task_event->task; - int ret; - - size = task_event->event.header.size; - ret = perf_output_begin(&handle, counter, size, 0, 0); - - if (ret) - return; - - task_event->event.pid = perf_counter_pid(counter, task); - task_event->event.ppid = perf_counter_pid(counter, current); - - task_event->event.tid = perf_counter_tid(counter, task); - task_event->event.ptid = perf_counter_tid(counter, current); - - task_event->event.time = perf_clock(); - - perf_output_put(&handle, task_event->event); - - perf_output_end(&handle); -} - -static int perf_counter_task_match(struct perf_counter *counter) -{ - if (counter->attr.comm || counter->attr.mmap || counter->attr.task) - return 1; - - return 0; -} - -static void perf_counter_task_ctx(struct perf_counter_context *ctx, - struct perf_task_event *task_event) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_counter_task_match(counter)) - perf_counter_task_output(counter, task_event); - } - rcu_read_unlock(); -} - -static void perf_counter_task_event(struct perf_task_event *task_event) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx = task_event->task_ctx; - - cpuctx = &get_cpu_var(perf_cpu_context); - perf_counter_task_ctx(&cpuctx->ctx, task_event); - put_cpu_var(perf_cpu_context); - - rcu_read_lock(); - if (!ctx) - ctx = rcu_dereference(task_event->task->perf_counter_ctxp); - if (ctx) - perf_counter_task_ctx(ctx, task_event); - rcu_read_unlock(); -} - -static void perf_counter_task(struct task_struct *task, - struct perf_counter_context *task_ctx, - int new) -{ - struct perf_task_event task_event; - - if (!atomic_read(&nr_comm_counters) && - !atomic_read(&nr_mmap_counters) && - !atomic_read(&nr_task_counters)) - return; - - task_event = (struct perf_task_event){ - .task = task, - .task_ctx = task_ctx, - .event = { - .header = { - .type = new ? PERF_EVENT_FORK : PERF_EVENT_EXIT, - .misc = 0, - .size = sizeof(task_event.event), - }, - /* .pid */ - /* .ppid */ - /* .tid */ - /* .ptid */ - }, - }; - - perf_counter_task_event(&task_event); -} - -void perf_counter_fork(struct task_struct *task) -{ - perf_counter_task(task, NULL, 1); -} - -/* - * comm tracking - */ - -struct perf_comm_event { - struct task_struct *task; - char *comm; - int comm_size; - - struct { - struct perf_event_header header; - - u32 pid; - u32 tid; - } event; -}; - -static void perf_counter_comm_output(struct perf_counter *counter, - struct perf_comm_event *comm_event) -{ - struct perf_output_handle handle; - int size = comm_event->event.header.size; - int ret = perf_output_begin(&handle, counter, size, 0, 0); - - if (ret) - return; - - comm_event->event.pid = perf_counter_pid(counter, comm_event->task); - comm_event->event.tid = perf_counter_tid(counter, comm_event->task); - - perf_output_put(&handle, comm_event->event); - perf_output_copy(&handle, comm_event->comm, - comm_event->comm_size); - perf_output_end(&handle); -} - -static int perf_counter_comm_match(struct perf_counter *counter) -{ - if (counter->attr.comm) - return 1; - - return 0; -} - -static void perf_counter_comm_ctx(struct perf_counter_context *ctx, - struct perf_comm_event *comm_event) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_counter_comm_match(counter)) - perf_counter_comm_output(counter, comm_event); - } - rcu_read_unlock(); -} - -static void perf_counter_comm_event(struct perf_comm_event *comm_event) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx; - unsigned int size; - char comm[TASK_COMM_LEN]; - - memset(comm, 0, sizeof(comm)); - strncpy(comm, comm_event->task->comm, sizeof(comm)); - size = ALIGN(strlen(comm)+1, sizeof(u64)); - - comm_event->comm = comm; - comm_event->comm_size = size; - - comm_event->event.header.size = sizeof(comm_event->event) + size; - - cpuctx = &get_cpu_var(perf_cpu_context); - perf_counter_comm_ctx(&cpuctx->ctx, comm_event); - put_cpu_var(perf_cpu_context); - - rcu_read_lock(); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_counter_ctxp); - if (ctx) - perf_counter_comm_ctx(ctx, comm_event); - rcu_read_unlock(); -} - -void perf_counter_comm(struct task_struct *task) -{ - struct perf_comm_event comm_event; - - if (task->perf_counter_ctxp) - perf_counter_enable_on_exec(task); - - if (!atomic_read(&nr_comm_counters)) - return; - - comm_event = (struct perf_comm_event){ - .task = task, - /* .comm */ - /* .comm_size */ - .event = { - .header = { - .type = PERF_EVENT_COMM, - .misc = 0, - /* .size */ - }, - /* .pid */ - /* .tid */ - }, - }; - - perf_counter_comm_event(&comm_event); -} - -/* - * mmap tracking - */ - -struct perf_mmap_event { - struct vm_area_struct *vma; - - const char *file_name; - int file_size; - - struct { - struct perf_event_header header; - - u32 pid; - u32 tid; - u64 start; - u64 len; - u64 pgoff; - } event; -}; - -static void perf_counter_mmap_output(struct perf_counter *counter, - struct perf_mmap_event *mmap_event) -{ - struct perf_output_handle handle; - int size = mmap_event->event.header.size; - int ret = perf_output_begin(&handle, counter, size, 0, 0); - - if (ret) - return; - - mmap_event->event.pid = perf_counter_pid(counter, current); - mmap_event->event.tid = perf_counter_tid(counter, current); - - perf_output_put(&handle, mmap_event->event); - perf_output_copy(&handle, mmap_event->file_name, - mmap_event->file_size); - perf_output_end(&handle); -} - -static int perf_counter_mmap_match(struct perf_counter *counter, - struct perf_mmap_event *mmap_event) -{ - if (counter->attr.mmap) - return 1; - - return 0; -} - -static void perf_counter_mmap_ctx(struct perf_counter_context *ctx, - struct perf_mmap_event *mmap_event) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_counter_mmap_match(counter, mmap_event)) - perf_counter_mmap_output(counter, mmap_event); - } - rcu_read_unlock(); -} - -static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event) -{ - struct perf_cpu_context *cpuctx; - struct perf_counter_context *ctx; - struct vm_area_struct *vma = mmap_event->vma; - struct file *file = vma->vm_file; - unsigned int size; - char tmp[16]; - char *buf = NULL; - const char *name; - - memset(tmp, 0, sizeof(tmp)); - - if (file) { - /* - * d_path works from the end of the buffer backwards, so we - * need to add enough zero bytes after the string to handle - * the 64bit alignment we do later. - */ - buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL); - if (!buf) { - name = strncpy(tmp, "//enomem", sizeof(tmp)); - goto got_name; - } - name = d_path(&file->f_path, buf, PATH_MAX); - if (IS_ERR(name)) { - name = strncpy(tmp, "//toolong", sizeof(tmp)); - goto got_name; - } - } else { - if (arch_vma_name(mmap_event->vma)) { - name = strncpy(tmp, arch_vma_name(mmap_event->vma), - sizeof(tmp)); - goto got_name; - } - - if (!vma->vm_mm) { - name = strncpy(tmp, "[vdso]", sizeof(tmp)); - goto got_name; - } - - name = strncpy(tmp, "//anon", sizeof(tmp)); - goto got_name; - } - -got_name: - size = ALIGN(strlen(name)+1, sizeof(u64)); - - mmap_event->file_name = name; - mmap_event->file_size = size; - - mmap_event->event.header.size = sizeof(mmap_event->event) + size; - - cpuctx = &get_cpu_var(perf_cpu_context); - perf_counter_mmap_ctx(&cpuctx->ctx, mmap_event); - put_cpu_var(perf_cpu_context); - - rcu_read_lock(); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_counter_ctxp); - if (ctx) - perf_counter_mmap_ctx(ctx, mmap_event); - rcu_read_unlock(); - - kfree(buf); -} - -void __perf_counter_mmap(struct vm_area_struct *vma) -{ - struct perf_mmap_event mmap_event; - - if (!atomic_read(&nr_mmap_counters)) - return; - - mmap_event = (struct perf_mmap_event){ - .vma = vma, - /* .file_name */ - /* .file_size */ - .event = { - .header = { - .type = PERF_EVENT_MMAP, - .misc = 0, - /* .size */ - }, - /* .pid */ - /* .tid */ - .start = vma->vm_start, - .len = vma->vm_end - vma->vm_start, - .pgoff = vma->vm_pgoff, - }, - }; - - perf_counter_mmap_event(&mmap_event); -} - -/* - * IRQ throttle logging - */ - -static void perf_log_throttle(struct perf_counter *counter, int enable) -{ - struct perf_output_handle handle; - int ret; - - struct { - struct perf_event_header header; - u64 time; - u64 id; - u64 stream_id; - } throttle_event = { - .header = { - .type = PERF_EVENT_THROTTLE, - .misc = 0, - .size = sizeof(throttle_event), - }, - .time = perf_clock(), - .id = primary_counter_id(counter), - .stream_id = counter->id, - }; - - if (enable) - throttle_event.header.type = PERF_EVENT_UNTHROTTLE; - - ret = perf_output_begin(&handle, counter, sizeof(throttle_event), 1, 0); - if (ret) - return; - - perf_output_put(&handle, throttle_event); - perf_output_end(&handle); -} - -/* - * Generic counter overflow handling, sampling. - */ - -static int __perf_counter_overflow(struct perf_counter *counter, int nmi, - int throttle, struct perf_sample_data *data, - struct pt_regs *regs) -{ - int events = atomic_read(&counter->event_limit); - struct hw_perf_counter *hwc = &counter->hw; - int ret = 0; - - throttle = (throttle && counter->pmu->unthrottle != NULL); - - if (!throttle) { - hwc->interrupts++; - } else { - if (hwc->interrupts != MAX_INTERRUPTS) { - hwc->interrupts++; - if (HZ * hwc->interrupts > - (u64)sysctl_perf_counter_sample_rate) { - hwc->interrupts = MAX_INTERRUPTS; - perf_log_throttle(counter, 0); - ret = 1; - } - } else { - /* - * Keep re-disabling counters even though on the previous - * pass we disabled it - just in case we raced with a - * sched-in and the counter got enabled again: - */ - ret = 1; - } - } - - if (counter->attr.freq) { - u64 now = perf_clock(); - s64 delta = now - hwc->freq_stamp; - - hwc->freq_stamp = now; - - if (delta > 0 && delta < TICK_NSEC) - perf_adjust_period(counter, NSEC_PER_SEC / (int)delta); - } - - /* - * XXX event_limit might not quite work as expected on inherited - * counters - */ - - counter->pending_kill = POLL_IN; - if (events && atomic_dec_and_test(&counter->event_limit)) { - ret = 1; - counter->pending_kill = POLL_HUP; - if (nmi) { - counter->pending_disable = 1; - perf_pending_queue(&counter->pending, - perf_pending_counter); - } else - perf_counter_disable(counter); - } - - perf_counter_output(counter, nmi, data, regs); - return ret; -} - -int perf_counter_overflow(struct perf_counter *counter, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - return __perf_counter_overflow(counter, nmi, 1, data, regs); -} - -/* - * Generic software counter infrastructure - */ - -/* - * We directly increment counter->count and keep a second value in - * counter->hw.period_left to count intervals. This period counter - * is kept in the range [-sample_period, 0] so that we can use the - * sign as trigger. - */ - -static u64 perf_swcounter_set_period(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - u64 period = hwc->last_period; - u64 nr, offset; - s64 old, val; - - hwc->last_period = hwc->sample_period; - -again: - old = val = atomic64_read(&hwc->period_left); - if (val < 0) - return 0; - - nr = div64_u64(period + val, period); - offset = nr * period; - val -= offset; - if (atomic64_cmpxchg(&hwc->period_left, old, val) != old) - goto again; - - return nr; -} - -static void perf_swcounter_overflow(struct perf_counter *counter, - int nmi, struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct hw_perf_counter *hwc = &counter->hw; - int throttle = 0; - u64 overflow; - - data->period = counter->hw.last_period; - overflow = perf_swcounter_set_period(counter); - - if (hwc->interrupts == MAX_INTERRUPTS) - return; - - for (; overflow; overflow--) { - if (__perf_counter_overflow(counter, nmi, throttle, - data, regs)) { - /* - * We inhibit the overflow from happening when - * hwc->interrupts == MAX_INTERRUPTS. - */ - break; - } - throttle = 1; - } -} - -static void perf_swcounter_unthrottle(struct perf_counter *counter) -{ - /* - * Nothing to do, we already reset hwc->interrupts. - */ -} - -static void perf_swcounter_add(struct perf_counter *counter, u64 nr, - int nmi, struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct hw_perf_counter *hwc = &counter->hw; - - atomic64_add(nr, &counter->count); - - if (!hwc->sample_period) - return; - - if (!regs) - return; - - if (!atomic64_add_negative(nr, &hwc->period_left)) - perf_swcounter_overflow(counter, nmi, data, regs); -} - -static int perf_swcounter_is_counting(struct perf_counter *counter) -{ - /* - * The counter is active, we're good! - */ - if (counter->state == PERF_COUNTER_STATE_ACTIVE) - return 1; - - /* - * The counter is off/error, not counting. - */ - if (counter->state != PERF_COUNTER_STATE_INACTIVE) - return 0; - - /* - * The counter is inactive, if the context is active - * we're part of a group that didn't make it on the 'pmu', - * not counting. - */ - if (counter->ctx->is_active) - return 0; - - /* - * We're inactive and the context is too, this means the - * task is scheduled out, we're counting events that happen - * to us, like migration events. - */ - return 1; -} - -static int perf_swcounter_match(struct perf_counter *counter, - enum perf_type_id type, - u32 event_id, struct pt_regs *regs) -{ - if (!perf_swcounter_is_counting(counter)) - return 0; - - if (counter->attr.type != type) - return 0; - if (counter->attr.config != event_id) - return 0; - - if (regs) { - if (counter->attr.exclude_user && user_mode(regs)) - return 0; - - if (counter->attr.exclude_kernel && !user_mode(regs)) - return 0; - } - - return 1; -} - -static void perf_swcounter_ctx_event(struct perf_counter_context *ctx, - enum perf_type_id type, - u32 event_id, u64 nr, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct perf_counter *counter; - - if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) - return; - - rcu_read_lock(); - list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) { - if (perf_swcounter_match(counter, type, event_id, regs)) - perf_swcounter_add(counter, nr, nmi, data, regs); - } - rcu_read_unlock(); -} - -static int *perf_swcounter_recursion_context(struct perf_cpu_context *cpuctx) -{ - if (in_nmi()) - return &cpuctx->recursion[3]; - - if (in_irq()) - return &cpuctx->recursion[2]; - - if (in_softirq()) - return &cpuctx->recursion[1]; - - return &cpuctx->recursion[0]; -} - -static void do_perf_swcounter_event(enum perf_type_id type, u32 event, - u64 nr, int nmi, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); - int *recursion = perf_swcounter_recursion_context(cpuctx); - struct perf_counter_context *ctx; - - if (*recursion) - goto out; - - (*recursion)++; - barrier(); - - perf_swcounter_ctx_event(&cpuctx->ctx, type, event, - nr, nmi, data, regs); - rcu_read_lock(); - /* - * doesn't really matter which of the child contexts the - * events ends up in. - */ - ctx = rcu_dereference(current->perf_counter_ctxp); - if (ctx) - perf_swcounter_ctx_event(ctx, type, event, nr, nmi, data, regs); - rcu_read_unlock(); - - barrier(); - (*recursion)--; - -out: - put_cpu_var(perf_cpu_context); -} - -void __perf_swcounter_event(u32 event, u64 nr, int nmi, - struct pt_regs *regs, u64 addr) -{ - struct perf_sample_data data = { - .addr = addr, - }; - - do_perf_swcounter_event(PERF_TYPE_SOFTWARE, event, nr, nmi, - &data, regs); -} - -static void perf_swcounter_read(struct perf_counter *counter) -{ -} - -static int perf_swcounter_enable(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - - if (hwc->sample_period) { - hwc->last_period = hwc->sample_period; - perf_swcounter_set_period(counter); - } - return 0; -} - -static void perf_swcounter_disable(struct perf_counter *counter) -{ -} - -static const struct pmu perf_ops_generic = { - .enable = perf_swcounter_enable, - .disable = perf_swcounter_disable, - .read = perf_swcounter_read, - .unthrottle = perf_swcounter_unthrottle, -}; - -/* - * hrtimer based swcounter callback - */ - -static enum hrtimer_restart perf_swcounter_hrtimer(struct hrtimer *hrtimer) -{ - enum hrtimer_restart ret = HRTIMER_RESTART; - struct perf_sample_data data; - struct pt_regs *regs; - struct perf_counter *counter; - u64 period; - - counter = container_of(hrtimer, struct perf_counter, hw.hrtimer); - counter->pmu->read(counter); - - data.addr = 0; - regs = get_irq_regs(); - /* - * In case we exclude kernel IPs or are somehow not in interrupt - * context, provide the next best thing, the user IP. - */ - if ((counter->attr.exclude_kernel || !regs) && - !counter->attr.exclude_user) - regs = task_pt_regs(current); - - if (regs) { - if (perf_counter_overflow(counter, 0, &data, regs)) - ret = HRTIMER_NORESTART; - } - - period = max_t(u64, 10000, counter->hw.sample_period); - hrtimer_forward_now(hrtimer, ns_to_ktime(period)); - - return ret; -} - -/* - * Software counter: cpu wall time clock - */ - -static void cpu_clock_perf_counter_update(struct perf_counter *counter) -{ - int cpu = raw_smp_processor_id(); - s64 prev; - u64 now; - - now = cpu_clock(cpu); - prev = atomic64_read(&counter->hw.prev_count); - atomic64_set(&counter->hw.prev_count, now); - atomic64_add(now - prev, &counter->count); -} - -static int cpu_clock_perf_counter_enable(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - int cpu = raw_smp_processor_id(); - - atomic64_set(&hwc->prev_count, cpu_clock(cpu)); - hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - hwc->hrtimer.function = perf_swcounter_hrtimer; - if (hwc->sample_period) { - u64 period = max_t(u64, 10000, hwc->sample_period); - __hrtimer_start_range_ns(&hwc->hrtimer, - ns_to_ktime(period), 0, - HRTIMER_MODE_REL, 0); - } - - return 0; -} - -static void cpu_clock_perf_counter_disable(struct perf_counter *counter) -{ - if (counter->hw.sample_period) - hrtimer_cancel(&counter->hw.hrtimer); - cpu_clock_perf_counter_update(counter); -} - -static void cpu_clock_perf_counter_read(struct perf_counter *counter) -{ - cpu_clock_perf_counter_update(counter); -} - -static const struct pmu perf_ops_cpu_clock = { - .enable = cpu_clock_perf_counter_enable, - .disable = cpu_clock_perf_counter_disable, - .read = cpu_clock_perf_counter_read, -}; - -/* - * Software counter: task time clock - */ - -static void task_clock_perf_counter_update(struct perf_counter *counter, u64 now) -{ - u64 prev; - s64 delta; - - prev = atomic64_xchg(&counter->hw.prev_count, now); - delta = now - prev; - atomic64_add(delta, &counter->count); -} - -static int task_clock_perf_counter_enable(struct perf_counter *counter) -{ - struct hw_perf_counter *hwc = &counter->hw; - u64 now; - - now = counter->ctx->time; - - atomic64_set(&hwc->prev_count, now); - hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - hwc->hrtimer.function = perf_swcounter_hrtimer; - if (hwc->sample_period) { - u64 period = max_t(u64, 10000, hwc->sample_period); - __hrtimer_start_range_ns(&hwc->hrtimer, - ns_to_ktime(period), 0, - HRTIMER_MODE_REL, 0); - } - - return 0; -} - -static void task_clock_perf_counter_disable(struct perf_counter *counter) -{ - if (counter->hw.sample_period) - hrtimer_cancel(&counter->hw.hrtimer); - task_clock_perf_counter_update(counter, counter->ctx->time); - -} - -static void task_clock_perf_counter_read(struct perf_counter *counter) -{ - u64 time; - - if (!in_nmi()) { - update_context_time(counter->ctx); - time = counter->ctx->time; - } else { - u64 now = perf_clock(); - u64 delta = now - counter->ctx->timestamp; - time = counter->ctx->time + delta; - } - - task_clock_perf_counter_update(counter, time); -} - -static const struct pmu perf_ops_task_clock = { - .enable = task_clock_perf_counter_enable, - .disable = task_clock_perf_counter_disable, - .read = task_clock_perf_counter_read, -}; - -#ifdef CONFIG_EVENT_PROFILE -void perf_tpcounter_event(int event_id, u64 addr, u64 count, void *record, - int entry_size) -{ - struct perf_raw_record raw = { - .size = entry_size, - .data = record, - }; - - struct perf_sample_data data = { - .addr = addr, - .raw = &raw, - }; - - struct pt_regs *regs = get_irq_regs(); - - if (!regs) - regs = task_pt_regs(current); - - do_perf_swcounter_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, - &data, regs); -} -EXPORT_SYMBOL_GPL(perf_tpcounter_event); - -extern int ftrace_profile_enable(int); -extern void ftrace_profile_disable(int); - -static void tp_perf_counter_destroy(struct perf_counter *counter) -{ - ftrace_profile_disable(counter->attr.config); -} - -static const struct pmu *tp_perf_counter_init(struct perf_counter *counter) -{ - /* - * Raw tracepoint data is a severe data leak, only allow root to - * have these. - */ - if ((counter->attr.sample_type & PERF_SAMPLE_RAW) && - perf_paranoid_tracepoint_raw() && - !capable(CAP_SYS_ADMIN)) - return ERR_PTR(-EPERM); - - if (ftrace_profile_enable(counter->attr.config)) - return NULL; - - counter->destroy = tp_perf_counter_destroy; - - return &perf_ops_generic; -} -#else -static const struct pmu *tp_perf_counter_init(struct perf_counter *counter) -{ - return NULL; -} -#endif - -atomic_t perf_swcounter_enabled[PERF_COUNT_SW_MAX]; - -static void sw_perf_counter_destroy(struct perf_counter *counter) -{ - u64 event_id = counter->attr.config; - - WARN_ON(counter->parent); - - atomic_dec(&perf_swcounter_enabled[event_id]); -} - -static const struct pmu *sw_perf_counter_init(struct perf_counter *counter) -{ - const struct pmu *pmu = NULL; - u64 event_id = counter->attr.config; - - /* - * Software counters (currently) can't in general distinguish - * between user, kernel and hypervisor events. - * However, context switches and cpu migrations are considered - * to be kernel events, and page faults are never hypervisor - * events. - */ - switch (event_id) { - case PERF_COUNT_SW_CPU_CLOCK: - pmu = &perf_ops_cpu_clock; - - break; - case PERF_COUNT_SW_TASK_CLOCK: - /* - * If the user instantiates this as a per-cpu counter, - * use the cpu_clock counter instead. - */ - if (counter->ctx->task) - pmu = &perf_ops_task_clock; - else - pmu = &perf_ops_cpu_clock; - - break; - case PERF_COUNT_SW_PAGE_FAULTS: - case PERF_COUNT_SW_PAGE_FAULTS_MIN: - case PERF_COUNT_SW_PAGE_FAULTS_MAJ: - case PERF_COUNT_SW_CONTEXT_SWITCHES: - case PERF_COUNT_SW_CPU_MIGRATIONS: - if (!counter->parent) { - atomic_inc(&perf_swcounter_enabled[event_id]); - counter->destroy = sw_perf_counter_destroy; - } - pmu = &perf_ops_generic; - break; - } - - return pmu; -} - -/* - * Allocate and initialize a counter structure - */ -static struct perf_counter * -perf_counter_alloc(struct perf_counter_attr *attr, - int cpu, - struct perf_counter_context *ctx, - struct perf_counter *group_leader, - struct perf_counter *parent_counter, - gfp_t gfpflags) -{ - const struct pmu *pmu; - struct perf_counter *counter; - struct hw_perf_counter *hwc; - long err; - - counter = kzalloc(sizeof(*counter), gfpflags); - if (!counter) - return ERR_PTR(-ENOMEM); - - /* - * Single counters are their own group leaders, with an - * empty sibling list: - */ - if (!group_leader) - group_leader = counter; - - mutex_init(&counter->child_mutex); - INIT_LIST_HEAD(&counter->child_list); - - INIT_LIST_HEAD(&counter->group_entry); - INIT_LIST_HEAD(&counter->event_entry); - INIT_LIST_HEAD(&counter->sibling_list); - init_waitqueue_head(&counter->waitq); - - mutex_init(&counter->mmap_mutex); - - counter->cpu = cpu; - counter->attr = *attr; - counter->group_leader = group_leader; - counter->pmu = NULL; - counter->ctx = ctx; - counter->oncpu = -1; - - counter->parent = parent_counter; - - counter->ns = get_pid_ns(current->nsproxy->pid_ns); - counter->id = atomic64_inc_return(&perf_counter_id); - - counter->state = PERF_COUNTER_STATE_INACTIVE; - - if (attr->disabled) - counter->state = PERF_COUNTER_STATE_OFF; - - pmu = NULL; - - hwc = &counter->hw; - hwc->sample_period = attr->sample_period; - if (attr->freq && attr->sample_freq) - hwc->sample_period = 1; - hwc->last_period = hwc->sample_period; - - atomic64_set(&hwc->period_left, hwc->sample_period); - - /* - * we currently do not support PERF_FORMAT_GROUP on inherited counters - */ - if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) - goto done; - - switch (attr->type) { - case PERF_TYPE_RAW: - case PERF_TYPE_HARDWARE: - case PERF_TYPE_HW_CACHE: - pmu = hw_perf_counter_init(counter); - break; - - case PERF_TYPE_SOFTWARE: - pmu = sw_perf_counter_init(counter); - break; - - case PERF_TYPE_TRACEPOINT: - pmu = tp_perf_counter_init(counter); - break; - - default: - break; - } -done: - err = 0; - if (!pmu) - err = -EINVAL; - else if (IS_ERR(pmu)) - err = PTR_ERR(pmu); - - if (err) { - if (counter->ns) - put_pid_ns(counter->ns); - kfree(counter); - return ERR_PTR(err); - } - - counter->pmu = pmu; - - if (!counter->parent) { - atomic_inc(&nr_counters); - if (counter->attr.mmap) - atomic_inc(&nr_mmap_counters); - if (counter->attr.comm) - atomic_inc(&nr_comm_counters); - if (counter->attr.task) - atomic_inc(&nr_task_counters); - } - - return counter; -} - -static int perf_copy_attr(struct perf_counter_attr __user *uattr, - struct perf_counter_attr *attr) -{ - u32 size; - int ret; - - if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) - return -EFAULT; - - /* - * zero the full structure, so that a short copy will be nice. - */ - memset(attr, 0, sizeof(*attr)); - - ret = get_user(size, &uattr->size); - if (ret) - return ret; - - if (size > PAGE_SIZE) /* silly large */ - goto err_size; - - if (!size) /* abi compat */ - size = PERF_ATTR_SIZE_VER0; - - if (size < PERF_ATTR_SIZE_VER0) - goto err_size; - - /* - * If we're handed a bigger struct than we know of, - * ensure all the unknown bits are 0 - i.e. new - * user-space does not rely on any kernel feature - * extensions we dont know about yet. - */ - if (size > sizeof(*attr)) { - unsigned char __user *addr; - unsigned char __user *end; - unsigned char val; - - addr = (void __user *)uattr + sizeof(*attr); - end = (void __user *)uattr + size; - - for (; addr < end; addr++) { - ret = get_user(val, addr); - if (ret) - return ret; - if (val) - goto err_size; - } - size = sizeof(*attr); - } - - ret = copy_from_user(attr, uattr, size); - if (ret) - return -EFAULT; - - /* - * If the type exists, the corresponding creation will verify - * the attr->config. - */ - if (attr->type >= PERF_TYPE_MAX) - return -EINVAL; - - if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3) - return -EINVAL; - - if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) - return -EINVAL; - - if (attr->read_format & ~(PERF_FORMAT_MAX-1)) - return -EINVAL; - -out: - return ret; - -err_size: - put_user(sizeof(*attr), &uattr->size); - ret = -E2BIG; - goto out; -} - -int perf_counter_set_output(struct perf_counter *counter, int output_fd) -{ - struct perf_counter *output_counter = NULL; - struct file *output_file = NULL; - struct perf_counter *old_output; - int fput_needed = 0; - int ret = -EINVAL; - - if (!output_fd) - goto set; - - output_file = fget_light(output_fd, &fput_needed); - if (!output_file) - return -EBADF; - - if (output_file->f_op != &perf_fops) - goto out; - - output_counter = output_file->private_data; - - /* Don't chain output fds */ - if (output_counter->output) - goto out; - - /* Don't set an output fd when we already have an output channel */ - if (counter->data) - goto out; - - atomic_long_inc(&output_file->f_count); - -set: - mutex_lock(&counter->mmap_mutex); - old_output = counter->output; - rcu_assign_pointer(counter->output, output_counter); - mutex_unlock(&counter->mmap_mutex); - - if (old_output) { - /* - * we need to make sure no existing perf_output_*() - * is still referencing this counter. - */ - synchronize_rcu(); - fput(old_output->filp); - } - - ret = 0; -out: - fput_light(output_file, fput_needed); - return ret; -} - -/** - * sys_perf_counter_open - open a performance counter, associate it to a task/cpu - * - * @attr_uptr: event type attributes for monitoring/sampling - * @pid: target pid - * @cpu: target cpu - * @group_fd: group leader counter fd - */ -SYSCALL_DEFINE5(perf_counter_open, - struct perf_counter_attr __user *, attr_uptr, - pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) -{ - struct perf_counter *counter, *group_leader; - struct perf_counter_attr attr; - struct perf_counter_context *ctx; - struct file *counter_file = NULL; - struct file *group_file = NULL; - int fput_needed = 0; - int fput_needed2 = 0; - int err; - - /* for future expandability... */ - if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT)) - return -EINVAL; - - err = perf_copy_attr(attr_uptr, &attr); - if (err) - return err; - - if (!attr.exclude_kernel) { - if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) - return -EACCES; - } - - if (attr.freq) { - if (attr.sample_freq > sysctl_perf_counter_sample_rate) - return -EINVAL; - } - - /* - * Get the target context (task or percpu): - */ - ctx = find_get_context(pid, cpu); - if (IS_ERR(ctx)) - return PTR_ERR(ctx); - - /* - * Look up the group leader (we will attach this counter to it): - */ - group_leader = NULL; - if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) { - err = -EINVAL; - group_file = fget_light(group_fd, &fput_needed); - if (!group_file) - goto err_put_context; - if (group_file->f_op != &perf_fops) - goto err_put_context; - - group_leader = group_file->private_data; - /* - * Do not allow a recursive hierarchy (this new sibling - * becoming part of another group-sibling): - */ - if (group_leader->group_leader != group_leader) - goto err_put_context; - /* - * Do not allow to attach to a group in a different - * task or CPU context: - */ - if (group_leader->ctx != ctx) - goto err_put_context; - /* - * Only a group leader can be exclusive or pinned - */ - if (attr.exclusive || attr.pinned) - goto err_put_context; - } - - counter = perf_counter_alloc(&attr, cpu, ctx, group_leader, - NULL, GFP_KERNEL); - err = PTR_ERR(counter); - if (IS_ERR(counter)) - goto err_put_context; - - err = anon_inode_getfd("[perf_counter]", &perf_fops, counter, 0); - if (err < 0) - goto err_free_put_context; - - counter_file = fget_light(err, &fput_needed2); - if (!counter_file) - goto err_free_put_context; - - if (flags & PERF_FLAG_FD_OUTPUT) { - err = perf_counter_set_output(counter, group_fd); - if (err) - goto err_fput_free_put_context; - } - - counter->filp = counter_file; - WARN_ON_ONCE(ctx->parent_ctx); - mutex_lock(&ctx->mutex); - perf_install_in_context(ctx, counter, cpu); - ++ctx->generation; - mutex_unlock(&ctx->mutex); - - counter->owner = current; - get_task_struct(current); - mutex_lock(¤t->perf_counter_mutex); - list_add_tail(&counter->owner_entry, ¤t->perf_counter_list); - mutex_unlock(¤t->perf_counter_mutex); - -err_fput_free_put_context: - fput_light(counter_file, fput_needed2); - -err_free_put_context: - if (err < 0) - kfree(counter); - -err_put_context: - if (err < 0) - put_ctx(ctx); - - fput_light(group_file, fput_needed); - - return err; -} - -/* - * inherit a counter from parent task to child task: - */ -static struct perf_counter * -inherit_counter(struct perf_counter *parent_counter, - struct task_struct *parent, - struct perf_counter_context *parent_ctx, - struct task_struct *child, - struct perf_counter *group_leader, - struct perf_counter_context *child_ctx) -{ - struct perf_counter *child_counter; - - /* - * Instead of creating recursive hierarchies of counters, - * we link inherited counters back to the original parent, - * which has a filp for sure, which we use as the reference - * count: - */ - if (parent_counter->parent) - parent_counter = parent_counter->parent; - - child_counter = perf_counter_alloc(&parent_counter->attr, - parent_counter->cpu, child_ctx, - group_leader, parent_counter, - GFP_KERNEL); - if (IS_ERR(child_counter)) - return child_counter; - get_ctx(child_ctx); - - /* - * Make the child state follow the state of the parent counter, - * not its attr.disabled bit. We hold the parent's mutex, - * so we won't race with perf_counter_{en, dis}able_family. - */ - if (parent_counter->state >= PERF_COUNTER_STATE_INACTIVE) - child_counter->state = PERF_COUNTER_STATE_INACTIVE; - else - child_counter->state = PERF_COUNTER_STATE_OFF; - - if (parent_counter->attr.freq) - child_counter->hw.sample_period = parent_counter->hw.sample_period; - - /* - * Link it up in the child's context: - */ - add_counter_to_ctx(child_counter, child_ctx); - - /* - * Get a reference to the parent filp - we will fput it - * when the child counter exits. This is safe to do because - * we are in the parent and we know that the filp still - * exists and has a nonzero count: - */ - atomic_long_inc(&parent_counter->filp->f_count); - - /* - * Link this into the parent counter's child list - */ - WARN_ON_ONCE(parent_counter->ctx->parent_ctx); - mutex_lock(&parent_counter->child_mutex); - list_add_tail(&child_counter->child_list, &parent_counter->child_list); - mutex_unlock(&parent_counter->child_mutex); - - return child_counter; -} - -static int inherit_group(struct perf_counter *parent_counter, - struct task_struct *parent, - struct perf_counter_context *parent_ctx, - struct task_struct *child, - struct perf_counter_context *child_ctx) -{ - struct perf_counter *leader; - struct perf_counter *sub; - struct perf_counter *child_ctr; - - leader = inherit_counter(parent_counter, parent, parent_ctx, - child, NULL, child_ctx); - if (IS_ERR(leader)) - return PTR_ERR(leader); - list_for_each_entry(sub, &parent_counter->sibling_list, group_entry) { - child_ctr = inherit_counter(sub, parent, parent_ctx, - child, leader, child_ctx); - if (IS_ERR(child_ctr)) - return PTR_ERR(child_ctr); - } - return 0; -} - -static void sync_child_counter(struct perf_counter *child_counter, - struct task_struct *child) -{ - struct perf_counter *parent_counter = child_counter->parent; - u64 child_val; - - if (child_counter->attr.inherit_stat) - perf_counter_read_event(child_counter, child); - - child_val = atomic64_read(&child_counter->count); - - /* - * Add back the child's count to the parent's count: - */ - atomic64_add(child_val, &parent_counter->count); - atomic64_add(child_counter->total_time_enabled, - &parent_counter->child_total_time_enabled); - atomic64_add(child_counter->total_time_running, - &parent_counter->child_total_time_running); - - /* - * Remove this counter from the parent's list - */ - WARN_ON_ONCE(parent_counter->ctx->parent_ctx); - mutex_lock(&parent_counter->child_mutex); - list_del_init(&child_counter->child_list); - mutex_unlock(&parent_counter->child_mutex); - - /* - * Release the parent counter, if this was the last - * reference to it. - */ - fput(parent_counter->filp); -} - -static void -__perf_counter_exit_task(struct perf_counter *child_counter, - struct perf_counter_context *child_ctx, - struct task_struct *child) -{ - struct perf_counter *parent_counter; - - update_counter_times(child_counter); - perf_counter_remove_from_context(child_counter); - - parent_counter = child_counter->parent; - /* - * It can happen that parent exits first, and has counters - * that are still around due to the child reference. These - * counters need to be zapped - but otherwise linger. - */ - if (parent_counter) { - sync_child_counter(child_counter, child); - free_counter(child_counter); - } -} - -/* - * When a child task exits, feed back counter values to parent counters. - */ -void perf_counter_exit_task(struct task_struct *child) -{ - struct perf_counter *child_counter, *tmp; - struct perf_counter_context *child_ctx; - unsigned long flags; - - if (likely(!child->perf_counter_ctxp)) { - perf_counter_task(child, NULL, 0); - return; - } - - local_irq_save(flags); - /* - * We can't reschedule here because interrupts are disabled, - * and either child is current or it is a task that can't be - * scheduled, so we are now safe from rescheduling changing - * our context. - */ - child_ctx = child->perf_counter_ctxp; - __perf_counter_task_sched_out(child_ctx); - - /* - * Take the context lock here so that if find_get_context is - * reading child->perf_counter_ctxp, we wait until it has - * incremented the context's refcount before we do put_ctx below. - */ - spin_lock(&child_ctx->lock); - child->perf_counter_ctxp = NULL; - /* - * If this context is a clone; unclone it so it can't get - * swapped to another process while we're removing all - * the counters from it. - */ - unclone_ctx(child_ctx); - spin_unlock_irqrestore(&child_ctx->lock, flags); - - /* - * Report the task dead after unscheduling the counters so that we - * won't get any samples after PERF_EVENT_EXIT. We can however still - * get a few PERF_EVENT_READ events. - */ - perf_counter_task(child, child_ctx, 0); - - /* - * We can recurse on the same lock type through: - * - * __perf_counter_exit_task() - * sync_child_counter() - * fput(parent_counter->filp) - * perf_release() - * mutex_lock(&ctx->mutex) - * - * But since its the parent context it won't be the same instance. - */ - mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); - -again: - list_for_each_entry_safe(child_counter, tmp, &child_ctx->group_list, - group_entry) - __perf_counter_exit_task(child_counter, child_ctx, child); - - /* - * If the last counter was a group counter, it will have appended all - * its siblings to the list, but we obtained 'tmp' before that which - * will still point to the list head terminating the iteration. - */ - if (!list_empty(&child_ctx->group_list)) - goto again; - - mutex_unlock(&child_ctx->mutex); - - put_ctx(child_ctx); -} - -/* - * free an unexposed, unused context as created by inheritance by - * init_task below, used by fork() in case of fail. - */ -void perf_counter_free_task(struct task_struct *task) -{ - struct perf_counter_context *ctx = task->perf_counter_ctxp; - struct perf_counter *counter, *tmp; - - if (!ctx) - return; - - mutex_lock(&ctx->mutex); -again: - list_for_each_entry_safe(counter, tmp, &ctx->group_list, group_entry) { - struct perf_counter *parent = counter->parent; - - if (WARN_ON_ONCE(!parent)) - continue; - - mutex_lock(&parent->child_mutex); - list_del_init(&counter->child_list); - mutex_unlock(&parent->child_mutex); - - fput(parent->filp); - - list_del_counter(counter, ctx); - free_counter(counter); - } - - if (!list_empty(&ctx->group_list)) - goto again; - - mutex_unlock(&ctx->mutex); - - put_ctx(ctx); -} - -/* - * Initialize the perf_counter context in task_struct - */ -int perf_counter_init_task(struct task_struct *child) -{ - struct perf_counter_context *child_ctx, *parent_ctx; - struct perf_counter_context *cloned_ctx; - struct perf_counter *counter; - struct task_struct *parent = current; - int inherited_all = 1; - int ret = 0; - - child->perf_counter_ctxp = NULL; - - mutex_init(&child->perf_counter_mutex); - INIT_LIST_HEAD(&child->perf_counter_list); - - if (likely(!parent->perf_counter_ctxp)) - return 0; - - /* - * This is executed from the parent task context, so inherit - * counters that have been marked for cloning. - * First allocate and initialize a context for the child. - */ - - child_ctx = kmalloc(sizeof(struct perf_counter_context), GFP_KERNEL); - if (!child_ctx) - return -ENOMEM; - - __perf_counter_init_context(child_ctx, child); - child->perf_counter_ctxp = child_ctx; - get_task_struct(child); - - /* - * If the parent's context is a clone, pin it so it won't get - * swapped under us. - */ - parent_ctx = perf_pin_task_context(parent); - - /* - * No need to check if parent_ctx != NULL here; since we saw - * it non-NULL earlier, the only reason for it to become NULL - * is if we exit, and since we're currently in the middle of - * a fork we can't be exiting at the same time. - */ - - /* - * Lock the parent list. No need to lock the child - not PID - * hashed yet and not running, so nobody can access it. - */ - mutex_lock(&parent_ctx->mutex); - - /* - * We dont have to disable NMIs - we are only looking at - * the list, not manipulating it: - */ - list_for_each_entry_rcu(counter, &parent_ctx->event_list, event_entry) { - if (counter != counter->group_leader) - continue; - - if (!counter->attr.inherit) { - inherited_all = 0; - continue; - } - - ret = inherit_group(counter, parent, parent_ctx, - child, child_ctx); - if (ret) { - inherited_all = 0; - break; - } - } - - if (inherited_all) { - /* - * Mark the child context as a clone of the parent - * context, or of whatever the parent is a clone of. - * Note that if the parent is a clone, it could get - * uncloned at any point, but that doesn't matter - * because the list of counters and the generation - * count can't have changed since we took the mutex. - */ - cloned_ctx = rcu_dereference(parent_ctx->parent_ctx); - if (cloned_ctx) { - child_ctx->parent_ctx = cloned_ctx; - child_ctx->parent_gen = parent_ctx->parent_gen; - } else { - child_ctx->parent_ctx = parent_ctx; - child_ctx->parent_gen = parent_ctx->generation; - } - get_ctx(child_ctx->parent_ctx); - } - - mutex_unlock(&parent_ctx->mutex); - - perf_unpin_context(parent_ctx); - - return ret; -} - -static void __cpuinit perf_counter_init_cpu(int cpu) -{ - struct perf_cpu_context *cpuctx; - - cpuctx = &per_cpu(perf_cpu_context, cpu); - __perf_counter_init_context(&cpuctx->ctx, NULL); - - spin_lock(&perf_resource_lock); - cpuctx->max_pertask = perf_max_counters - perf_reserved_percpu; - spin_unlock(&perf_resource_lock); - - hw_perf_counter_setup(cpu); -} - -#ifdef CONFIG_HOTPLUG_CPU -static void __perf_counter_exit_cpu(void *info) -{ - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); - struct perf_counter_context *ctx = &cpuctx->ctx; - struct perf_counter *counter, *tmp; - - list_for_each_entry_safe(counter, tmp, &ctx->group_list, group_entry) - __perf_counter_remove_from_context(counter); -} -static void perf_counter_exit_cpu(int cpu) -{ - struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); - struct perf_counter_context *ctx = &cpuctx->ctx; - - mutex_lock(&ctx->mutex); - smp_call_function_single(cpu, __perf_counter_exit_cpu, NULL, 1); - mutex_unlock(&ctx->mutex); -} -#else -static inline void perf_counter_exit_cpu(int cpu) { } -#endif - -static int __cpuinit -perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) -{ - unsigned int cpu = (long)hcpu; - - switch (action) { - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - perf_counter_init_cpu(cpu); - break; - - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - hw_perf_counter_setup_online(cpu); - break; - - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - perf_counter_exit_cpu(cpu); - break; - - default: - break; - } - - return NOTIFY_OK; -} - -/* - * This has to have a higher priority than migration_notifier in sched.c. - */ -static struct notifier_block __cpuinitdata perf_cpu_nb = { - .notifier_call = perf_cpu_notify, - .priority = 20, -}; - -void __init perf_counter_init(void) -{ - perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, - (void *)(long)smp_processor_id()); - perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE, - (void *)(long)smp_processor_id()); - register_cpu_notifier(&perf_cpu_nb); -} - -static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) -{ - return sprintf(buf, "%d\n", perf_reserved_percpu); -} - -static ssize_t -perf_set_reserve_percpu(struct sysdev_class *class, - const char *buf, - size_t count) -{ - struct perf_cpu_context *cpuctx; - unsigned long val; - int err, cpu, mpt; - - err = strict_strtoul(buf, 10, &val); - if (err) - return err; - if (val > perf_max_counters) - return -EINVAL; - - spin_lock(&perf_resource_lock); - perf_reserved_percpu = val; - for_each_online_cpu(cpu) { - cpuctx = &per_cpu(perf_cpu_context, cpu); - spin_lock_irq(&cpuctx->ctx.lock); - mpt = min(perf_max_counters - cpuctx->ctx.nr_counters, - perf_max_counters - perf_reserved_percpu); - cpuctx->max_pertask = mpt; - spin_unlock_irq(&cpuctx->ctx.lock); - } - spin_unlock(&perf_resource_lock); - - return count; -} - -static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) -{ - return sprintf(buf, "%d\n", perf_overcommit); -} - -static ssize_t -perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) -{ - unsigned long val; - int err; - - err = strict_strtoul(buf, 10, &val); - if (err) - return err; - if (val > 1) - return -EINVAL; - - spin_lock(&perf_resource_lock); - perf_overcommit = val; - spin_unlock(&perf_resource_lock); - - return count; -} - -static SYSDEV_CLASS_ATTR( - reserve_percpu, - 0644, - perf_show_reserve_percpu, - perf_set_reserve_percpu - ); - -static SYSDEV_CLASS_ATTR( - overcommit, - 0644, - perf_show_overcommit, - perf_set_overcommit - ); - -static struct attribute *perfclass_attrs[] = { - &attr_reserve_percpu.attr, - &attr_overcommit.attr, - NULL -}; - -static struct attribute_group perfclass_attr_group = { - .attrs = perfclass_attrs, - .name = "perf_counters", -}; - -static int __init perf_counter_sysfs_init(void) -{ - return sysfs_create_group(&cpu_sysdev_class.kset.kobj, - &perfclass_attr_group); -} -device_initcall(perf_counter_sysfs_init); diff --git a/kernel/perf_event.c b/kernel/perf_event.c new file mode 100644 index 000000000000..6e8b99a04e1e --- /dev/null +++ b/kernel/perf_event.c @@ -0,0 +1,5000 @@ +/* + * Performance event core code + * + * Copyright (C) 2008 Thomas Gleixner + * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar + * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra + * Copyright © 2009 Paul Mackerras, IBM Corp. + * + * For licensing details see kernel-base/COPYING + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* + * Each CPU has a list of per CPU events: + */ +DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context); + +int perf_max_events __read_mostly = 1; +static int perf_reserved_percpu __read_mostly; +static int perf_overcommit __read_mostly = 1; + +static atomic_t nr_events __read_mostly; +static atomic_t nr_mmap_events __read_mostly; +static atomic_t nr_comm_events __read_mostly; +static atomic_t nr_task_events __read_mostly; + +/* + * perf event paranoia level: + * -1 - not paranoid at all + * 0 - disallow raw tracepoint access for unpriv + * 1 - disallow cpu events for unpriv + * 2 - disallow kernel profiling for unpriv + */ +int sysctl_perf_event_paranoid __read_mostly = 1; + +static inline bool perf_paranoid_tracepoint_raw(void) +{ + return sysctl_perf_event_paranoid > -1; +} + +static inline bool perf_paranoid_cpu(void) +{ + return sysctl_perf_event_paranoid > 0; +} + +static inline bool perf_paranoid_kernel(void) +{ + return sysctl_perf_event_paranoid > 1; +} + +int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */ + +/* + * max perf event sample rate + */ +int sysctl_perf_event_sample_rate __read_mostly = 100000; + +static atomic64_t perf_event_id; + +/* + * Lock for (sysadmin-configurable) event reservations: + */ +static DEFINE_SPINLOCK(perf_resource_lock); + +/* + * Architecture provided APIs - weak aliases: + */ +extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event) +{ + return NULL; +} + +void __weak hw_perf_disable(void) { barrier(); } +void __weak hw_perf_enable(void) { barrier(); } + +void __weak hw_perf_event_setup(int cpu) { barrier(); } +void __weak hw_perf_event_setup_online(int cpu) { barrier(); } + +int __weak +hw_perf_group_sched_in(struct perf_event *group_leader, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx, int cpu) +{ + return 0; +} + +void __weak perf_event_print_debug(void) { } + +static DEFINE_PER_CPU(int, perf_disable_count); + +void __perf_disable(void) +{ + __get_cpu_var(perf_disable_count)++; +} + +bool __perf_enable(void) +{ + return !--__get_cpu_var(perf_disable_count); +} + +void perf_disable(void) +{ + __perf_disable(); + hw_perf_disable(); +} + +void perf_enable(void) +{ + if (__perf_enable()) + hw_perf_enable(); +} + +static void get_ctx(struct perf_event_context *ctx) +{ + WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); +} + +static void free_ctx(struct rcu_head *head) +{ + struct perf_event_context *ctx; + + ctx = container_of(head, struct perf_event_context, rcu_head); + kfree(ctx); +} + +static void put_ctx(struct perf_event_context *ctx) +{ + if (atomic_dec_and_test(&ctx->refcount)) { + if (ctx->parent_ctx) + put_ctx(ctx->parent_ctx); + if (ctx->task) + put_task_struct(ctx->task); + call_rcu(&ctx->rcu_head, free_ctx); + } +} + +static void unclone_ctx(struct perf_event_context *ctx) +{ + if (ctx->parent_ctx) { + put_ctx(ctx->parent_ctx); + ctx->parent_ctx = NULL; + } +} + +/* + * If we inherit events we want to return the parent event id + * to userspace. + */ +static u64 primary_event_id(struct perf_event *event) +{ + u64 id = event->id; + + if (event->parent) + id = event->parent->id; + + return id; +} + +/* + * Get the perf_event_context for a task and lock it. + * This has to cope with with the fact that until it is locked, + * the context could get moved to another task. + */ +static struct perf_event_context * +perf_lock_task_context(struct task_struct *task, unsigned long *flags) +{ + struct perf_event_context *ctx; + + rcu_read_lock(); + retry: + ctx = rcu_dereference(task->perf_event_ctxp); + if (ctx) { + /* + * If this context is a clone of another, it might + * get swapped for another underneath us by + * perf_event_task_sched_out, though the + * rcu_read_lock() protects us from any context + * getting freed. Lock the context and check if it + * got swapped before we could get the lock, and retry + * if so. If we locked the right context, then it + * can't get swapped on us any more. + */ + spin_lock_irqsave(&ctx->lock, *flags); + if (ctx != rcu_dereference(task->perf_event_ctxp)) { + spin_unlock_irqrestore(&ctx->lock, *flags); + goto retry; + } + + if (!atomic_inc_not_zero(&ctx->refcount)) { + spin_unlock_irqrestore(&ctx->lock, *flags); + ctx = NULL; + } + } + rcu_read_unlock(); + return ctx; +} + +/* + * Get the context for a task and increment its pin_count so it + * can't get swapped to another task. This also increments its + * reference count so that the context can't get freed. + */ +static struct perf_event_context *perf_pin_task_context(struct task_struct *task) +{ + struct perf_event_context *ctx; + unsigned long flags; + + ctx = perf_lock_task_context(task, &flags); + if (ctx) { + ++ctx->pin_count; + spin_unlock_irqrestore(&ctx->lock, flags); + } + return ctx; +} + +static void perf_unpin_context(struct perf_event_context *ctx) +{ + unsigned long flags; + + spin_lock_irqsave(&ctx->lock, flags); + --ctx->pin_count; + spin_unlock_irqrestore(&ctx->lock, flags); + put_ctx(ctx); +} + +/* + * Add a event from the lists for its context. + * Must be called with ctx->mutex and ctx->lock held. + */ +static void +list_add_event(struct perf_event *event, struct perf_event_context *ctx) +{ + struct perf_event *group_leader = event->group_leader; + + /* + * Depending on whether it is a standalone or sibling event, + * add it straight to the context's event list, or to the group + * leader's sibling list: + */ + if (group_leader == event) + list_add_tail(&event->group_entry, &ctx->group_list); + else { + list_add_tail(&event->group_entry, &group_leader->sibling_list); + group_leader->nr_siblings++; + } + + list_add_rcu(&event->event_entry, &ctx->event_list); + ctx->nr_events++; + if (event->attr.inherit_stat) + ctx->nr_stat++; +} + +/* + * Remove a event from the lists for its context. + * Must be called with ctx->mutex and ctx->lock held. + */ +static void +list_del_event(struct perf_event *event, struct perf_event_context *ctx) +{ + struct perf_event *sibling, *tmp; + + if (list_empty(&event->group_entry)) + return; + ctx->nr_events--; + if (event->attr.inherit_stat) + ctx->nr_stat--; + + list_del_init(&event->group_entry); + list_del_rcu(&event->event_entry); + + if (event->group_leader != event) + event->group_leader->nr_siblings--; + + /* + * If this was a group event with sibling events then + * upgrade the siblings to singleton events by adding them + * to the context list directly: + */ + list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) { + + list_move_tail(&sibling->group_entry, &ctx->group_list); + sibling->group_leader = sibling; + } +} + +static void +event_sched_out(struct perf_event *event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + if (event->state != PERF_EVENT_STATE_ACTIVE) + return; + + event->state = PERF_EVENT_STATE_INACTIVE; + if (event->pending_disable) { + event->pending_disable = 0; + event->state = PERF_EVENT_STATE_OFF; + } + event->tstamp_stopped = ctx->time; + event->pmu->disable(event); + event->oncpu = -1; + + if (!is_software_event(event)) + cpuctx->active_oncpu--; + ctx->nr_active--; + if (event->attr.exclusive || !cpuctx->active_oncpu) + cpuctx->exclusive = 0; +} + +static void +group_sched_out(struct perf_event *group_event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx) +{ + struct perf_event *event; + + if (group_event->state != PERF_EVENT_STATE_ACTIVE) + return; + + event_sched_out(group_event, cpuctx, ctx); + + /* + * Schedule out siblings (if any): + */ + list_for_each_entry(event, &group_event->sibling_list, group_entry) + event_sched_out(event, cpuctx, ctx); + + if (group_event->attr.exclusive) + cpuctx->exclusive = 0; +} + +/* + * Cross CPU call to remove a performance event + * + * We disable the event on the hardware level first. After that we + * remove it from the context list. + */ +static void __perf_event_remove_from_context(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event *event = info; + struct perf_event_context *ctx = event->ctx; + + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + + spin_lock(&ctx->lock); + /* + * Protect the list operation against NMI by disabling the + * events on a global level. + */ + perf_disable(); + + event_sched_out(event, cpuctx, ctx); + + list_del_event(event, ctx); + + if (!ctx->task) { + /* + * Allow more per task events with respect to the + * reservation: + */ + cpuctx->max_pertask = + min(perf_max_events - ctx->nr_events, + perf_max_events - perf_reserved_percpu); + } + + perf_enable(); + spin_unlock(&ctx->lock); +} + + +/* + * Remove the event from a task's (or a CPU's) list of events. + * + * Must be called with ctx->mutex held. + * + * CPU events are removed with a smp call. For task events we only + * call when the task is on a CPU. + * + * If event->ctx is a cloned context, callers must make sure that + * every task struct that event->ctx->task could possibly point to + * remains valid. This is OK when called from perf_release since + * that only calls us on the top-level context, which can't be a clone. + * When called from perf_event_exit_task, it's OK because the + * context has been detached from its task. + */ +static void perf_event_remove_from_context(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Per cpu events are removed via an smp call and + * the removal is always sucessful. + */ + smp_call_function_single(event->cpu, + __perf_event_remove_from_context, + event, 1); + return; + } + +retry: + task_oncpu_function_call(task, __perf_event_remove_from_context, + event); + + spin_lock_irq(&ctx->lock); + /* + * If the context is active we need to retry the smp call. + */ + if (ctx->nr_active && !list_empty(&event->group_entry)) { + spin_unlock_irq(&ctx->lock); + goto retry; + } + + /* + * The lock prevents that this context is scheduled in so we + * can remove the event safely, if the call above did not + * succeed. + */ + if (!list_empty(&event->group_entry)) { + list_del_event(event, ctx); + } + spin_unlock_irq(&ctx->lock); +} + +static inline u64 perf_clock(void) +{ + return cpu_clock(smp_processor_id()); +} + +/* + * Update the record of the current time in a context. + */ +static void update_context_time(struct perf_event_context *ctx) +{ + u64 now = perf_clock(); + + ctx->time += now - ctx->timestamp; + ctx->timestamp = now; +} + +/* + * Update the total_time_enabled and total_time_running fields for a event. + */ +static void update_event_times(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + u64 run_end; + + if (event->state < PERF_EVENT_STATE_INACTIVE || + event->group_leader->state < PERF_EVENT_STATE_INACTIVE) + return; + + event->total_time_enabled = ctx->time - event->tstamp_enabled; + + if (event->state == PERF_EVENT_STATE_INACTIVE) + run_end = event->tstamp_stopped; + else + run_end = ctx->time; + + event->total_time_running = run_end - event->tstamp_running; +} + +/* + * Update total_time_enabled and total_time_running for all events in a group. + */ +static void update_group_times(struct perf_event *leader) +{ + struct perf_event *event; + + update_event_times(leader); + list_for_each_entry(event, &leader->sibling_list, group_entry) + update_event_times(event); +} + +/* + * Cross CPU call to disable a performance event + */ +static void __perf_event_disable(void *info) +{ + struct perf_event *event = info; + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event_context *ctx = event->ctx; + + /* + * If this is a per-task event, need to check whether this + * event's task is the current task on this cpu. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + + spin_lock(&ctx->lock); + + /* + * If the event is on, turn it off. + * If it is in error state, leave it in error state. + */ + if (event->state >= PERF_EVENT_STATE_INACTIVE) { + update_context_time(ctx); + update_group_times(event); + if (event == event->group_leader) + group_sched_out(event, cpuctx, ctx); + else + event_sched_out(event, cpuctx, ctx); + event->state = PERF_EVENT_STATE_OFF; + } + + spin_unlock(&ctx->lock); +} + +/* + * Disable a event. + * + * If event->ctx is a cloned context, callers must make sure that + * every task struct that event->ctx->task could possibly point to + * remains valid. This condition is satisifed when called through + * perf_event_for_each_child or perf_event_for_each because they + * hold the top-level event's child_mutex, so any descendant that + * goes to exit will block in sync_child_event. + * When called from perf_pending_event it's OK because event->ctx + * is the current context on this CPU and preemption is disabled, + * hence we can't get into perf_event_task_sched_out for this context. + */ +static void perf_event_disable(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Disable the event on the cpu that it's on + */ + smp_call_function_single(event->cpu, __perf_event_disable, + event, 1); + return; + } + + retry: + task_oncpu_function_call(task, __perf_event_disable, event); + + spin_lock_irq(&ctx->lock); + /* + * If the event is still active, we need to retry the cross-call. + */ + if (event->state == PERF_EVENT_STATE_ACTIVE) { + spin_unlock_irq(&ctx->lock); + goto retry; + } + + /* + * Since we have the lock this context can't be scheduled + * in, so we can change the state safely. + */ + if (event->state == PERF_EVENT_STATE_INACTIVE) { + update_group_times(event); + event->state = PERF_EVENT_STATE_OFF; + } + + spin_unlock_irq(&ctx->lock); +} + +static int +event_sched_in(struct perf_event *event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx, + int cpu) +{ + if (event->state <= PERF_EVENT_STATE_OFF) + return 0; + + event->state = PERF_EVENT_STATE_ACTIVE; + event->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */ + /* + * The new state must be visible before we turn it on in the hardware: + */ + smp_wmb(); + + if (event->pmu->enable(event)) { + event->state = PERF_EVENT_STATE_INACTIVE; + event->oncpu = -1; + return -EAGAIN; + } + + event->tstamp_running += ctx->time - event->tstamp_stopped; + + if (!is_software_event(event)) + cpuctx->active_oncpu++; + ctx->nr_active++; + + if (event->attr.exclusive) + cpuctx->exclusive = 1; + + return 0; +} + +static int +group_sched_in(struct perf_event *group_event, + struct perf_cpu_context *cpuctx, + struct perf_event_context *ctx, + int cpu) +{ + struct perf_event *event, *partial_group; + int ret; + + if (group_event->state == PERF_EVENT_STATE_OFF) + return 0; + + ret = hw_perf_group_sched_in(group_event, cpuctx, ctx, cpu); + if (ret) + return ret < 0 ? ret : 0; + + if (event_sched_in(group_event, cpuctx, ctx, cpu)) + return -EAGAIN; + + /* + * Schedule in siblings as one group (if any): + */ + list_for_each_entry(event, &group_event->sibling_list, group_entry) { + if (event_sched_in(event, cpuctx, ctx, cpu)) { + partial_group = event; + goto group_error; + } + } + + return 0; + +group_error: + /* + * Groups can be scheduled in as one unit only, so undo any + * partial group before returning: + */ + list_for_each_entry(event, &group_event->sibling_list, group_entry) { + if (event == partial_group) + break; + event_sched_out(event, cpuctx, ctx); + } + event_sched_out(group_event, cpuctx, ctx); + + return -EAGAIN; +} + +/* + * Return 1 for a group consisting entirely of software events, + * 0 if the group contains any hardware events. + */ +static int is_software_only_group(struct perf_event *leader) +{ + struct perf_event *event; + + if (!is_software_event(leader)) + return 0; + + list_for_each_entry(event, &leader->sibling_list, group_entry) + if (!is_software_event(event)) + return 0; + + return 1; +} + +/* + * Work out whether we can put this event group on the CPU now. + */ +static int group_can_go_on(struct perf_event *event, + struct perf_cpu_context *cpuctx, + int can_add_hw) +{ + /* + * Groups consisting entirely of software events can always go on. + */ + if (is_software_only_group(event)) + return 1; + /* + * If an exclusive group is already on, no other hardware + * events can go on. + */ + if (cpuctx->exclusive) + return 0; + /* + * If this group is exclusive and there are already + * events on the CPU, it can't go on. + */ + if (event->attr.exclusive && cpuctx->active_oncpu) + return 0; + /* + * Otherwise, try to add it if all previous groups were able + * to go on. + */ + return can_add_hw; +} + +static void add_event_to_ctx(struct perf_event *event, + struct perf_event_context *ctx) +{ + list_add_event(event, ctx); + event->tstamp_enabled = ctx->time; + event->tstamp_running = ctx->time; + event->tstamp_stopped = ctx->time; +} + +/* + * Cross CPU call to install and enable a performance event + * + * Must be called with ctx->mutex held + */ +static void __perf_install_in_context(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event *event = info; + struct perf_event_context *ctx = event->ctx; + struct perf_event *leader = event->group_leader; + int cpu = smp_processor_id(); + int err; + + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. + * Or possibly this is the right context but it isn't + * on this cpu because it had no events. + */ + if (ctx->task && cpuctx->task_ctx != ctx) { + if (cpuctx->task_ctx || ctx->task != current) + return; + cpuctx->task_ctx = ctx; + } + + spin_lock(&ctx->lock); + ctx->is_active = 1; + update_context_time(ctx); + + /* + * Protect the list operation against NMI by disabling the + * events on a global level. NOP for non NMI based events. + */ + perf_disable(); + + add_event_to_ctx(event, ctx); + + /* + * Don't put the event on if it is disabled or if + * it is in a group and the group isn't on. + */ + if (event->state != PERF_EVENT_STATE_INACTIVE || + (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)) + goto unlock; + + /* + * An exclusive event can't go on if there are already active + * hardware events, and no hardware event can go on if there + * is already an exclusive event on. + */ + if (!group_can_go_on(event, cpuctx, 1)) + err = -EEXIST; + else + err = event_sched_in(event, cpuctx, ctx, cpu); + + if (err) { + /* + * This event couldn't go on. If it is in a group + * then we have to pull the whole group off. + * If the event group is pinned then put it in error state. + */ + if (leader != event) + group_sched_out(leader, cpuctx, ctx); + if (leader->attr.pinned) { + update_group_times(leader); + leader->state = PERF_EVENT_STATE_ERROR; + } + } + + if (!err && !ctx->task && cpuctx->max_pertask) + cpuctx->max_pertask--; + + unlock: + perf_enable(); + + spin_unlock(&ctx->lock); +} + +/* + * Attach a performance event to a context + * + * First we add the event to the list with the hardware enable bit + * in event->hw_config cleared. + * + * If the event is attached to a task which is on a CPU we use a smp + * call to enable it in the task context. The task might have been + * scheduled away, but we check this in the smp call again. + * + * Must be called with ctx->mutex held. + */ +static void +perf_install_in_context(struct perf_event_context *ctx, + struct perf_event *event, + int cpu) +{ + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Per cpu events are installed via an smp call and + * the install is always sucessful. + */ + smp_call_function_single(cpu, __perf_install_in_context, + event, 1); + return; + } + +retry: + task_oncpu_function_call(task, __perf_install_in_context, + event); + + spin_lock_irq(&ctx->lock); + /* + * we need to retry the smp call. + */ + if (ctx->is_active && list_empty(&event->group_entry)) { + spin_unlock_irq(&ctx->lock); + goto retry; + } + + /* + * The lock prevents that this context is scheduled in so we + * can add the event safely, if it the call above did not + * succeed. + */ + if (list_empty(&event->group_entry)) + add_event_to_ctx(event, ctx); + spin_unlock_irq(&ctx->lock); +} + +/* + * Put a event into inactive state and update time fields. + * Enabling the leader of a group effectively enables all + * the group members that aren't explicitly disabled, so we + * have to update their ->tstamp_enabled also. + * Note: this works for group members as well as group leaders + * since the non-leader members' sibling_lists will be empty. + */ +static void __perf_event_mark_enabled(struct perf_event *event, + struct perf_event_context *ctx) +{ + struct perf_event *sub; + + event->state = PERF_EVENT_STATE_INACTIVE; + event->tstamp_enabled = ctx->time - event->total_time_enabled; + list_for_each_entry(sub, &event->sibling_list, group_entry) + if (sub->state >= PERF_EVENT_STATE_INACTIVE) + sub->tstamp_enabled = + ctx->time - sub->total_time_enabled; +} + +/* + * Cross CPU call to enable a performance event + */ +static void __perf_event_enable(void *info) +{ + struct perf_event *event = info; + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event_context *ctx = event->ctx; + struct perf_event *leader = event->group_leader; + int err; + + /* + * If this is a per-task event, need to check whether this + * event's task is the current task on this cpu. + */ + if (ctx->task && cpuctx->task_ctx != ctx) { + if (cpuctx->task_ctx || ctx->task != current) + return; + cpuctx->task_ctx = ctx; + } + + spin_lock(&ctx->lock); + ctx->is_active = 1; + update_context_time(ctx); + + if (event->state >= PERF_EVENT_STATE_INACTIVE) + goto unlock; + __perf_event_mark_enabled(event, ctx); + + /* + * If the event is in a group and isn't the group leader, + * then don't put it on unless the group is on. + */ + if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) + goto unlock; + + if (!group_can_go_on(event, cpuctx, 1)) { + err = -EEXIST; + } else { + perf_disable(); + if (event == leader) + err = group_sched_in(event, cpuctx, ctx, + smp_processor_id()); + else + err = event_sched_in(event, cpuctx, ctx, + smp_processor_id()); + perf_enable(); + } + + if (err) { + /* + * If this event can't go on and it's part of a + * group, then the whole group has to come off. + */ + if (leader != event) + group_sched_out(leader, cpuctx, ctx); + if (leader->attr.pinned) { + update_group_times(leader); + leader->state = PERF_EVENT_STATE_ERROR; + } + } + + unlock: + spin_unlock(&ctx->lock); +} + +/* + * Enable a event. + * + * If event->ctx is a cloned context, callers must make sure that + * every task struct that event->ctx->task could possibly point to + * remains valid. This condition is satisfied when called through + * perf_event_for_each_child or perf_event_for_each as described + * for perf_event_disable. + */ +static void perf_event_enable(struct perf_event *event) +{ + struct perf_event_context *ctx = event->ctx; + struct task_struct *task = ctx->task; + + if (!task) { + /* + * Enable the event on the cpu that it's on + */ + smp_call_function_single(event->cpu, __perf_event_enable, + event, 1); + return; + } + + spin_lock_irq(&ctx->lock); + if (event->state >= PERF_EVENT_STATE_INACTIVE) + goto out; + + /* + * If the event is in error state, clear that first. + * That way, if we see the event in error state below, we + * know that it has gone back into error state, as distinct + * from the task having been scheduled away before the + * cross-call arrived. + */ + if (event->state == PERF_EVENT_STATE_ERROR) + event->state = PERF_EVENT_STATE_OFF; + + retry: + spin_unlock_irq(&ctx->lock); + task_oncpu_function_call(task, __perf_event_enable, event); + + spin_lock_irq(&ctx->lock); + + /* + * If the context is active and the event is still off, + * we need to retry the cross-call. + */ + if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) + goto retry; + + /* + * Since we have the lock this context can't be scheduled + * in, so we can change the state safely. + */ + if (event->state == PERF_EVENT_STATE_OFF) + __perf_event_mark_enabled(event, ctx); + + out: + spin_unlock_irq(&ctx->lock); +} + +static int perf_event_refresh(struct perf_event *event, int refresh) +{ + /* + * not supported on inherited events + */ + if (event->attr.inherit) + return -EINVAL; + + atomic_add(refresh, &event->event_limit); + perf_event_enable(event); + + return 0; +} + +void __perf_event_sched_out(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx) +{ + struct perf_event *event; + + spin_lock(&ctx->lock); + ctx->is_active = 0; + if (likely(!ctx->nr_events)) + goto out; + update_context_time(ctx); + + perf_disable(); + if (ctx->nr_active) { + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (event != event->group_leader) + event_sched_out(event, cpuctx, ctx); + else + group_sched_out(event, cpuctx, ctx); + } + } + perf_enable(); + out: + spin_unlock(&ctx->lock); +} + +/* + * Test whether two contexts are equivalent, i.e. whether they + * have both been cloned from the same version of the same context + * and they both have the same number of enabled events. + * If the number of enabled events is the same, then the set + * of enabled events should be the same, because these are both + * inherited contexts, therefore we can't access individual events + * in them directly with an fd; we can only enable/disable all + * events via prctl, or enable/disable all events in a family + * via ioctl, which will have the same effect on both contexts. + */ +static int context_equiv(struct perf_event_context *ctx1, + struct perf_event_context *ctx2) +{ + return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx + && ctx1->parent_gen == ctx2->parent_gen + && !ctx1->pin_count && !ctx2->pin_count; +} + +static void __perf_event_read(void *event); + +static void __perf_event_sync_stat(struct perf_event *event, + struct perf_event *next_event) +{ + u64 value; + + if (!event->attr.inherit_stat) + return; + + /* + * Update the event value, we cannot use perf_event_read() + * because we're in the middle of a context switch and have IRQs + * disabled, which upsets smp_call_function_single(), however + * we know the event must be on the current CPU, therefore we + * don't need to use it. + */ + switch (event->state) { + case PERF_EVENT_STATE_ACTIVE: + __perf_event_read(event); + break; + + case PERF_EVENT_STATE_INACTIVE: + update_event_times(event); + break; + + default: + break; + } + + /* + * In order to keep per-task stats reliable we need to flip the event + * values when we flip the contexts. + */ + value = atomic64_read(&next_event->count); + value = atomic64_xchg(&event->count, value); + atomic64_set(&next_event->count, value); + + swap(event->total_time_enabled, next_event->total_time_enabled); + swap(event->total_time_running, next_event->total_time_running); + + /* + * Since we swizzled the values, update the user visible data too. + */ + perf_event_update_userpage(event); + perf_event_update_userpage(next_event); +} + +#define list_next_entry(pos, member) \ + list_entry(pos->member.next, typeof(*pos), member) + +static void perf_event_sync_stat(struct perf_event_context *ctx, + struct perf_event_context *next_ctx) +{ + struct perf_event *event, *next_event; + + if (!ctx->nr_stat) + return; + + event = list_first_entry(&ctx->event_list, + struct perf_event, event_entry); + + next_event = list_first_entry(&next_ctx->event_list, + struct perf_event, event_entry); + + while (&event->event_entry != &ctx->event_list && + &next_event->event_entry != &next_ctx->event_list) { + + __perf_event_sync_stat(event, next_event); + + event = list_next_entry(event, event_entry); + next_event = list_next_entry(next_event, event_entry); + } +} + +/* + * Called from scheduler to remove the events of the current task, + * with interrupts disabled. + * + * We stop each event and update the event value in event->count. + * + * This does not protect us against NMI, but disable() + * sets the disabled bit in the control field of event _before_ + * accessing the event control register. If a NMI hits, then it will + * not restart the event. + */ +void perf_event_task_sched_out(struct task_struct *task, + struct task_struct *next, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_event_context *ctx = task->perf_event_ctxp; + struct perf_event_context *next_ctx; + struct perf_event_context *parent; + struct pt_regs *regs; + int do_switch = 1; + + regs = task_pt_regs(task); + perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0); + + if (likely(!ctx || !cpuctx->task_ctx)) + return; + + update_context_time(ctx); + + rcu_read_lock(); + parent = rcu_dereference(ctx->parent_ctx); + next_ctx = next->perf_event_ctxp; + if (parent && next_ctx && + rcu_dereference(next_ctx->parent_ctx) == parent) { + /* + * Looks like the two contexts are clones, so we might be + * able to optimize the context switch. We lock both + * contexts and check that they are clones under the + * lock (including re-checking that neither has been + * uncloned in the meantime). It doesn't matter which + * order we take the locks because no other cpu could + * be trying to lock both of these tasks. + */ + spin_lock(&ctx->lock); + spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING); + if (context_equiv(ctx, next_ctx)) { + /* + * XXX do we need a memory barrier of sorts + * wrt to rcu_dereference() of perf_event_ctxp + */ + task->perf_event_ctxp = next_ctx; + next->perf_event_ctxp = ctx; + ctx->task = next; + next_ctx->task = task; + do_switch = 0; + + perf_event_sync_stat(ctx, next_ctx); + } + spin_unlock(&next_ctx->lock); + spin_unlock(&ctx->lock); + } + rcu_read_unlock(); + + if (do_switch) { + __perf_event_sched_out(ctx, cpuctx); + cpuctx->task_ctx = NULL; + } +} + +/* + * Called with IRQs disabled + */ +static void __perf_event_task_sched_out(struct perf_event_context *ctx) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + + if (!cpuctx->task_ctx) + return; + + if (WARN_ON_ONCE(ctx != cpuctx->task_ctx)) + return; + + __perf_event_sched_out(ctx, cpuctx); + cpuctx->task_ctx = NULL; +} + +/* + * Called with IRQs disabled + */ +static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx) +{ + __perf_event_sched_out(&cpuctx->ctx, cpuctx); +} + +static void +__perf_event_sched_in(struct perf_event_context *ctx, + struct perf_cpu_context *cpuctx, int cpu) +{ + struct perf_event *event; + int can_add_hw = 1; + + spin_lock(&ctx->lock); + ctx->is_active = 1; + if (likely(!ctx->nr_events)) + goto out; + + ctx->timestamp = perf_clock(); + + perf_disable(); + + /* + * First go through the list and put on any pinned groups + * in order to give them the best chance of going on. + */ + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (event->state <= PERF_EVENT_STATE_OFF || + !event->attr.pinned) + continue; + if (event->cpu != -1 && event->cpu != cpu) + continue; + + if (event != event->group_leader) + event_sched_in(event, cpuctx, ctx, cpu); + else { + if (group_can_go_on(event, cpuctx, 1)) + group_sched_in(event, cpuctx, ctx, cpu); + } + + /* + * If this pinned group hasn't been scheduled, + * put it in error state. + */ + if (event->state == PERF_EVENT_STATE_INACTIVE) { + update_group_times(event); + event->state = PERF_EVENT_STATE_ERROR; + } + } + + list_for_each_entry(event, &ctx->group_list, group_entry) { + /* + * Ignore events in OFF or ERROR state, and + * ignore pinned events since we did them already. + */ + if (event->state <= PERF_EVENT_STATE_OFF || + event->attr.pinned) + continue; + + /* + * Listen to the 'cpu' scheduling filter constraint + * of events: + */ + if (event->cpu != -1 && event->cpu != cpu) + continue; + + if (event != event->group_leader) { + if (event_sched_in(event, cpuctx, ctx, cpu)) + can_add_hw = 0; + } else { + if (group_can_go_on(event, cpuctx, can_add_hw)) { + if (group_sched_in(event, cpuctx, ctx, cpu)) + can_add_hw = 0; + } + } + } + perf_enable(); + out: + spin_unlock(&ctx->lock); +} + +/* + * Called from scheduler to add the events of the current task + * with interrupts disabled. + * + * We restore the event value and then enable it. + * + * This does not protect us against NMI, but enable() + * sets the enabled bit in the control field of event _before_ + * accessing the event control register. If a NMI hits, then it will + * keep the event running. + */ +void perf_event_task_sched_in(struct task_struct *task, int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_event_context *ctx = task->perf_event_ctxp; + + if (likely(!ctx)) + return; + if (cpuctx->task_ctx == ctx) + return; + __perf_event_sched_in(ctx, cpuctx, cpu); + cpuctx->task_ctx = ctx; +} + +static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu) +{ + struct perf_event_context *ctx = &cpuctx->ctx; + + __perf_event_sched_in(ctx, cpuctx, cpu); +} + +#define MAX_INTERRUPTS (~0ULL) + +static void perf_log_throttle(struct perf_event *event, int enable); + +static void perf_adjust_period(struct perf_event *event, u64 events) +{ + struct hw_perf_event *hwc = &event->hw; + u64 period, sample_period; + s64 delta; + + events *= hwc->sample_period; + period = div64_u64(events, event->attr.sample_freq); + + delta = (s64)(period - hwc->sample_period); + delta = (delta + 7) / 8; /* low pass filter */ + + sample_period = hwc->sample_period + delta; + + if (!sample_period) + sample_period = 1; + + hwc->sample_period = sample_period; +} + +static void perf_ctx_adjust_freq(struct perf_event_context *ctx) +{ + struct perf_event *event; + struct hw_perf_event *hwc; + u64 interrupts, freq; + + spin_lock(&ctx->lock); + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (event->state != PERF_EVENT_STATE_ACTIVE) + continue; + + hwc = &event->hw; + + interrupts = hwc->interrupts; + hwc->interrupts = 0; + + /* + * unthrottle events on the tick + */ + if (interrupts == MAX_INTERRUPTS) { + perf_log_throttle(event, 1); + event->pmu->unthrottle(event); + interrupts = 2*sysctl_perf_event_sample_rate/HZ; + } + + if (!event->attr.freq || !event->attr.sample_freq) + continue; + + /* + * if the specified freq < HZ then we need to skip ticks + */ + if (event->attr.sample_freq < HZ) { + freq = event->attr.sample_freq; + + hwc->freq_count += freq; + hwc->freq_interrupts += interrupts; + + if (hwc->freq_count < HZ) + continue; + + interrupts = hwc->freq_interrupts; + hwc->freq_interrupts = 0; + hwc->freq_count -= HZ; + } else + freq = HZ; + + perf_adjust_period(event, freq * interrupts); + + /* + * In order to avoid being stalled by an (accidental) huge + * sample period, force reset the sample period if we didn't + * get any events in this freq period. + */ + if (!interrupts) { + perf_disable(); + event->pmu->disable(event); + atomic64_set(&hwc->period_left, 0); + event->pmu->enable(event); + perf_enable(); + } + } + spin_unlock(&ctx->lock); +} + +/* + * Round-robin a context's events: + */ +static void rotate_ctx(struct perf_event_context *ctx) +{ + struct perf_event *event; + + if (!ctx->nr_events) + return; + + spin_lock(&ctx->lock); + /* + * Rotate the first entry last (works just fine for group events too): + */ + perf_disable(); + list_for_each_entry(event, &ctx->group_list, group_entry) { + list_move_tail(&event->group_entry, &ctx->group_list); + break; + } + perf_enable(); + + spin_unlock(&ctx->lock); +} + +void perf_event_task_tick(struct task_struct *curr, int cpu) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; + + if (!atomic_read(&nr_events)) + return; + + cpuctx = &per_cpu(perf_cpu_context, cpu); + ctx = curr->perf_event_ctxp; + + perf_ctx_adjust_freq(&cpuctx->ctx); + if (ctx) + perf_ctx_adjust_freq(ctx); + + perf_event_cpu_sched_out(cpuctx); + if (ctx) + __perf_event_task_sched_out(ctx); + + rotate_ctx(&cpuctx->ctx); + if (ctx) + rotate_ctx(ctx); + + perf_event_cpu_sched_in(cpuctx, cpu); + if (ctx) + perf_event_task_sched_in(curr, cpu); +} + +/* + * Enable all of a task's events that have been marked enable-on-exec. + * This expects task == current. + */ +static void perf_event_enable_on_exec(struct task_struct *task) +{ + struct perf_event_context *ctx; + struct perf_event *event; + unsigned long flags; + int enabled = 0; + + local_irq_save(flags); + ctx = task->perf_event_ctxp; + if (!ctx || !ctx->nr_events) + goto out; + + __perf_event_task_sched_out(ctx); + + spin_lock(&ctx->lock); + + list_for_each_entry(event, &ctx->group_list, group_entry) { + if (!event->attr.enable_on_exec) + continue; + event->attr.enable_on_exec = 0; + if (event->state >= PERF_EVENT_STATE_INACTIVE) + continue; + __perf_event_mark_enabled(event, ctx); + enabled = 1; + } + + /* + * Unclone this context if we enabled any event. + */ + if (enabled) + unclone_ctx(ctx); + + spin_unlock(&ctx->lock); + + perf_event_task_sched_in(task, smp_processor_id()); + out: + local_irq_restore(flags); +} + +/* + * Cross CPU call to read the hardware event + */ +static void __perf_event_read(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event *event = info; + struct perf_event_context *ctx = event->ctx; + unsigned long flags; + + /* + * If this is a task context, we need to check whether it is + * the current task context of this cpu. If not it has been + * scheduled out before the smp call arrived. In that case + * event->count would have been updated to a recent sample + * when the event was scheduled out. + */ + if (ctx->task && cpuctx->task_ctx != ctx) + return; + + local_irq_save(flags); + if (ctx->is_active) + update_context_time(ctx); + event->pmu->read(event); + update_event_times(event); + local_irq_restore(flags); +} + +static u64 perf_event_read(struct perf_event *event) +{ + /* + * If event is enabled and currently active on a CPU, update the + * value in the event structure: + */ + if (event->state == PERF_EVENT_STATE_ACTIVE) { + smp_call_function_single(event->oncpu, + __perf_event_read, event, 1); + } else if (event->state == PERF_EVENT_STATE_INACTIVE) { + update_event_times(event); + } + + return atomic64_read(&event->count); +} + +/* + * Initialize the perf_event context in a task_struct: + */ +static void +__perf_event_init_context(struct perf_event_context *ctx, + struct task_struct *task) +{ + memset(ctx, 0, sizeof(*ctx)); + spin_lock_init(&ctx->lock); + mutex_init(&ctx->mutex); + INIT_LIST_HEAD(&ctx->group_list); + INIT_LIST_HEAD(&ctx->event_list); + atomic_set(&ctx->refcount, 1); + ctx->task = task; +} + +static struct perf_event_context *find_get_context(pid_t pid, int cpu) +{ + struct perf_event_context *ctx; + struct perf_cpu_context *cpuctx; + struct task_struct *task; + unsigned long flags; + int err; + + /* + * If cpu is not a wildcard then this is a percpu event: + */ + if (cpu != -1) { + /* Must be root to operate on a CPU event: */ + if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EACCES); + + if (cpu < 0 || cpu > num_possible_cpus()) + return ERR_PTR(-EINVAL); + + /* + * We could be clever and allow to attach a event to an + * offline CPU and activate it when the CPU comes up, but + * that's for later. + */ + if (!cpu_isset(cpu, cpu_online_map)) + return ERR_PTR(-ENODEV); + + cpuctx = &per_cpu(perf_cpu_context, cpu); + ctx = &cpuctx->ctx; + get_ctx(ctx); + + return ctx; + } + + rcu_read_lock(); + if (!pid) + task = current; + else + task = find_task_by_vpid(pid); + if (task) + get_task_struct(task); + rcu_read_unlock(); + + if (!task) + return ERR_PTR(-ESRCH); + + /* + * Can't attach events to a dying task. + */ + err = -ESRCH; + if (task->flags & PF_EXITING) + goto errout; + + /* Reuse ptrace permission checks for now. */ + err = -EACCES; + if (!ptrace_may_access(task, PTRACE_MODE_READ)) + goto errout; + + retry: + ctx = perf_lock_task_context(task, &flags); + if (ctx) { + unclone_ctx(ctx); + spin_unlock_irqrestore(&ctx->lock, flags); + } + + if (!ctx) { + ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL); + err = -ENOMEM; + if (!ctx) + goto errout; + __perf_event_init_context(ctx, task); + get_ctx(ctx); + if (cmpxchg(&task->perf_event_ctxp, NULL, ctx)) { + /* + * We raced with some other task; use + * the context they set. + */ + kfree(ctx); + goto retry; + } + get_task_struct(task); + } + + put_task_struct(task); + return ctx; + + errout: + put_task_struct(task); + return ERR_PTR(err); +} + +static void free_event_rcu(struct rcu_head *head) +{ + struct perf_event *event; + + event = container_of(head, struct perf_event, rcu_head); + if (event->ns) + put_pid_ns(event->ns); + kfree(event); +} + +static void perf_pending_sync(struct perf_event *event); + +static void free_event(struct perf_event *event) +{ + perf_pending_sync(event); + + if (!event->parent) { + atomic_dec(&nr_events); + if (event->attr.mmap) + atomic_dec(&nr_mmap_events); + if (event->attr.comm) + atomic_dec(&nr_comm_events); + if (event->attr.task) + atomic_dec(&nr_task_events); + } + + if (event->output) { + fput(event->output->filp); + event->output = NULL; + } + + if (event->destroy) + event->destroy(event); + + put_ctx(event->ctx); + call_rcu(&event->rcu_head, free_event_rcu); +} + +/* + * Called when the last reference to the file is gone. + */ +static int perf_release(struct inode *inode, struct file *file) +{ + struct perf_event *event = file->private_data; + struct perf_event_context *ctx = event->ctx; + + file->private_data = NULL; + + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + perf_event_remove_from_context(event); + mutex_unlock(&ctx->mutex); + + mutex_lock(&event->owner->perf_event_mutex); + list_del_init(&event->owner_entry); + mutex_unlock(&event->owner->perf_event_mutex); + put_task_struct(event->owner); + + free_event(event); + + return 0; +} + +static int perf_event_read_size(struct perf_event *event) +{ + int entry = sizeof(u64); /* value */ + int size = 0; + int nr = 1; + + if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) + size += sizeof(u64); + + if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) + size += sizeof(u64); + + if (event->attr.read_format & PERF_FORMAT_ID) + entry += sizeof(u64); + + if (event->attr.read_format & PERF_FORMAT_GROUP) { + nr += event->group_leader->nr_siblings; + size += sizeof(u64); + } + + size += entry * nr; + + return size; +} + +static u64 perf_event_read_value(struct perf_event *event) +{ + struct perf_event *child; + u64 total = 0; + + total += perf_event_read(event); + list_for_each_entry(child, &event->child_list, child_list) + total += perf_event_read(child); + + return total; +} + +static int perf_event_read_entry(struct perf_event *event, + u64 read_format, char __user *buf) +{ + int n = 0, count = 0; + u64 values[2]; + + values[n++] = perf_event_read_value(event); + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(event); + + count = n * sizeof(u64); + + if (copy_to_user(buf, values, count)) + return -EFAULT; + + return count; +} + +static int perf_event_read_group(struct perf_event *event, + u64 read_format, char __user *buf) +{ + struct perf_event *leader = event->group_leader, *sub; + int n = 0, size = 0, err = -EFAULT; + u64 values[3]; + + values[n++] = 1 + leader->nr_siblings; + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { + values[n++] = leader->total_time_enabled + + atomic64_read(&leader->child_total_time_enabled); + } + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { + values[n++] = leader->total_time_running + + atomic64_read(&leader->child_total_time_running); + } + + size = n * sizeof(u64); + + if (copy_to_user(buf, values, size)) + return -EFAULT; + + err = perf_event_read_entry(leader, read_format, buf + size); + if (err < 0) + return err; + + size += err; + + list_for_each_entry(sub, &leader->sibling_list, group_entry) { + err = perf_event_read_entry(sub, read_format, + buf + size); + if (err < 0) + return err; + + size += err; + } + + return size; +} + +static int perf_event_read_one(struct perf_event *event, + u64 read_format, char __user *buf) +{ + u64 values[4]; + int n = 0; + + values[n++] = perf_event_read_value(event); + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { + values[n++] = event->total_time_enabled + + atomic64_read(&event->child_total_time_enabled); + } + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { + values[n++] = event->total_time_running + + atomic64_read(&event->child_total_time_running); + } + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(event); + + if (copy_to_user(buf, values, n * sizeof(u64))) + return -EFAULT; + + return n * sizeof(u64); +} + +/* + * Read the performance event - simple non blocking version for now + */ +static ssize_t +perf_read_hw(struct perf_event *event, char __user *buf, size_t count) +{ + u64 read_format = event->attr.read_format; + int ret; + + /* + * Return end-of-file for a read on a event that is in + * error state (i.e. because it was pinned but it couldn't be + * scheduled on to the CPU at some point). + */ + if (event->state == PERF_EVENT_STATE_ERROR) + return 0; + + if (count < perf_event_read_size(event)) + return -ENOSPC; + + WARN_ON_ONCE(event->ctx->parent_ctx); + mutex_lock(&event->child_mutex); + if (read_format & PERF_FORMAT_GROUP) + ret = perf_event_read_group(event, read_format, buf); + else + ret = perf_event_read_one(event, read_format, buf); + mutex_unlock(&event->child_mutex); + + return ret; +} + +static ssize_t +perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) +{ + struct perf_event *event = file->private_data; + + return perf_read_hw(event, buf, count); +} + +static unsigned int perf_poll(struct file *file, poll_table *wait) +{ + struct perf_event *event = file->private_data; + struct perf_mmap_data *data; + unsigned int events = POLL_HUP; + + rcu_read_lock(); + data = rcu_dereference(event->data); + if (data) + events = atomic_xchg(&data->poll, 0); + rcu_read_unlock(); + + poll_wait(file, &event->waitq, wait); + + return events; +} + +static void perf_event_reset(struct perf_event *event) +{ + (void)perf_event_read(event); + atomic64_set(&event->count, 0); + perf_event_update_userpage(event); +} + +/* + * Holding the top-level event's child_mutex means that any + * descendant process that has inherited this event will block + * in sync_child_event if it goes to exit, thus satisfying the + * task existence requirements of perf_event_enable/disable. + */ +static void perf_event_for_each_child(struct perf_event *event, + void (*func)(struct perf_event *)) +{ + struct perf_event *child; + + WARN_ON_ONCE(event->ctx->parent_ctx); + mutex_lock(&event->child_mutex); + func(event); + list_for_each_entry(child, &event->child_list, child_list) + func(child); + mutex_unlock(&event->child_mutex); +} + +static void perf_event_for_each(struct perf_event *event, + void (*func)(struct perf_event *)) +{ + struct perf_event_context *ctx = event->ctx; + struct perf_event *sibling; + + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + event = event->group_leader; + + perf_event_for_each_child(event, func); + func(event); + list_for_each_entry(sibling, &event->sibling_list, group_entry) + perf_event_for_each_child(event, func); + mutex_unlock(&ctx->mutex); +} + +static int perf_event_period(struct perf_event *event, u64 __user *arg) +{ + struct perf_event_context *ctx = event->ctx; + unsigned long size; + int ret = 0; + u64 value; + + if (!event->attr.sample_period) + return -EINVAL; + + size = copy_from_user(&value, arg, sizeof(value)); + if (size != sizeof(value)) + return -EFAULT; + + if (!value) + return -EINVAL; + + spin_lock_irq(&ctx->lock); + if (event->attr.freq) { + if (value > sysctl_perf_event_sample_rate) { + ret = -EINVAL; + goto unlock; + } + + event->attr.sample_freq = value; + } else { + event->attr.sample_period = value; + event->hw.sample_period = value; + } +unlock: + spin_unlock_irq(&ctx->lock); + + return ret; +} + +int perf_event_set_output(struct perf_event *event, int output_fd); + +static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct perf_event *event = file->private_data; + void (*func)(struct perf_event *); + u32 flags = arg; + + switch (cmd) { + case PERF_EVENT_IOC_ENABLE: + func = perf_event_enable; + break; + case PERF_EVENT_IOC_DISABLE: + func = perf_event_disable; + break; + case PERF_EVENT_IOC_RESET: + func = perf_event_reset; + break; + + case PERF_EVENT_IOC_REFRESH: + return perf_event_refresh(event, arg); + + case PERF_EVENT_IOC_PERIOD: + return perf_event_period(event, (u64 __user *)arg); + + case PERF_EVENT_IOC_SET_OUTPUT: + return perf_event_set_output(event, arg); + + default: + return -ENOTTY; + } + + if (flags & PERF_IOC_FLAG_GROUP) + perf_event_for_each(event, func); + else + perf_event_for_each_child(event, func); + + return 0; +} + +int perf_event_task_enable(void) +{ + struct perf_event *event; + + mutex_lock(¤t->perf_event_mutex); + list_for_each_entry(event, ¤t->perf_event_list, owner_entry) + perf_event_for_each_child(event, perf_event_enable); + mutex_unlock(¤t->perf_event_mutex); + + return 0; +} + +int perf_event_task_disable(void) +{ + struct perf_event *event; + + mutex_lock(¤t->perf_event_mutex); + list_for_each_entry(event, ¤t->perf_event_list, owner_entry) + perf_event_for_each_child(event, perf_event_disable); + mutex_unlock(¤t->perf_event_mutex); + + return 0; +} + +#ifndef PERF_EVENT_INDEX_OFFSET +# define PERF_EVENT_INDEX_OFFSET 0 +#endif + +static int perf_event_index(struct perf_event *event) +{ + if (event->state != PERF_EVENT_STATE_ACTIVE) + return 0; + + return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET; +} + +/* + * Callers need to ensure there can be no nesting of this function, otherwise + * the seqlock logic goes bad. We can not serialize this because the arch + * code calls this from NMI context. + */ +void perf_event_update_userpage(struct perf_event *event) +{ + struct perf_event_mmap_page *userpg; + struct perf_mmap_data *data; + + rcu_read_lock(); + data = rcu_dereference(event->data); + if (!data) + goto unlock; + + userpg = data->user_page; + + /* + * Disable preemption so as to not let the corresponding user-space + * spin too long if we get preempted. + */ + preempt_disable(); + ++userpg->lock; + barrier(); + userpg->index = perf_event_index(event); + userpg->offset = atomic64_read(&event->count); + if (event->state == PERF_EVENT_STATE_ACTIVE) + userpg->offset -= atomic64_read(&event->hw.prev_count); + + userpg->time_enabled = event->total_time_enabled + + atomic64_read(&event->child_total_time_enabled); + + userpg->time_running = event->total_time_running + + atomic64_read(&event->child_total_time_running); + + barrier(); + ++userpg->lock; + preempt_enable(); +unlock: + rcu_read_unlock(); +} + +static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct perf_event *event = vma->vm_file->private_data; + struct perf_mmap_data *data; + int ret = VM_FAULT_SIGBUS; + + if (vmf->flags & FAULT_FLAG_MKWRITE) { + if (vmf->pgoff == 0) + ret = 0; + return ret; + } + + rcu_read_lock(); + data = rcu_dereference(event->data); + if (!data) + goto unlock; + + if (vmf->pgoff == 0) { + vmf->page = virt_to_page(data->user_page); + } else { + int nr = vmf->pgoff - 1; + + if ((unsigned)nr > data->nr_pages) + goto unlock; + + if (vmf->flags & FAULT_FLAG_WRITE) + goto unlock; + + vmf->page = virt_to_page(data->data_pages[nr]); + } + + get_page(vmf->page); + vmf->page->mapping = vma->vm_file->f_mapping; + vmf->page->index = vmf->pgoff; + + ret = 0; +unlock: + rcu_read_unlock(); + + return ret; +} + +static int perf_mmap_data_alloc(struct perf_event *event, int nr_pages) +{ + struct perf_mmap_data *data; + unsigned long size; + int i; + + WARN_ON(atomic_read(&event->mmap_count)); + + size = sizeof(struct perf_mmap_data); + size += nr_pages * sizeof(void *); + + data = kzalloc(size, GFP_KERNEL); + if (!data) + goto fail; + + data->user_page = (void *)get_zeroed_page(GFP_KERNEL); + if (!data->user_page) + goto fail_user_page; + + for (i = 0; i < nr_pages; i++) { + data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL); + if (!data->data_pages[i]) + goto fail_data_pages; + } + + data->nr_pages = nr_pages; + atomic_set(&data->lock, -1); + + if (event->attr.watermark) { + data->watermark = min_t(long, PAGE_SIZE * nr_pages, + event->attr.wakeup_watermark); + } + if (!data->watermark) + data->watermark = max(PAGE_SIZE, PAGE_SIZE * nr_pages / 4); + + rcu_assign_pointer(event->data, data); + + return 0; + +fail_data_pages: + for (i--; i >= 0; i--) + free_page((unsigned long)data->data_pages[i]); + + free_page((unsigned long)data->user_page); + +fail_user_page: + kfree(data); + +fail: + return -ENOMEM; +} + +static void perf_mmap_free_page(unsigned long addr) +{ + struct page *page = virt_to_page((void *)addr); + + page->mapping = NULL; + __free_page(page); +} + +static void __perf_mmap_data_free(struct rcu_head *rcu_head) +{ + struct perf_mmap_data *data; + int i; + + data = container_of(rcu_head, struct perf_mmap_data, rcu_head); + + perf_mmap_free_page((unsigned long)data->user_page); + for (i = 0; i < data->nr_pages; i++) + perf_mmap_free_page((unsigned long)data->data_pages[i]); + + kfree(data); +} + +static void perf_mmap_data_free(struct perf_event *event) +{ + struct perf_mmap_data *data = event->data; + + WARN_ON(atomic_read(&event->mmap_count)); + + rcu_assign_pointer(event->data, NULL); + call_rcu(&data->rcu_head, __perf_mmap_data_free); +} + +static void perf_mmap_open(struct vm_area_struct *vma) +{ + struct perf_event *event = vma->vm_file->private_data; + + atomic_inc(&event->mmap_count); +} + +static void perf_mmap_close(struct vm_area_struct *vma) +{ + struct perf_event *event = vma->vm_file->private_data; + + WARN_ON_ONCE(event->ctx->parent_ctx); + if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) { + struct user_struct *user = current_user(); + + atomic_long_sub(event->data->nr_pages + 1, &user->locked_vm); + vma->vm_mm->locked_vm -= event->data->nr_locked; + perf_mmap_data_free(event); + mutex_unlock(&event->mmap_mutex); + } +} + +static struct vm_operations_struct perf_mmap_vmops = { + .open = perf_mmap_open, + .close = perf_mmap_close, + .fault = perf_mmap_fault, + .page_mkwrite = perf_mmap_fault, +}; + +static int perf_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct perf_event *event = file->private_data; + unsigned long user_locked, user_lock_limit; + struct user_struct *user = current_user(); + unsigned long locked, lock_limit; + unsigned long vma_size; + unsigned long nr_pages; + long user_extra, extra; + int ret = 0; + + if (!(vma->vm_flags & VM_SHARED)) + return -EINVAL; + + vma_size = vma->vm_end - vma->vm_start; + nr_pages = (vma_size / PAGE_SIZE) - 1; + + /* + * If we have data pages ensure they're a power-of-two number, so we + * can do bitmasks instead of modulo. + */ + if (nr_pages != 0 && !is_power_of_2(nr_pages)) + return -EINVAL; + + if (vma_size != PAGE_SIZE * (1 + nr_pages)) + return -EINVAL; + + if (vma->vm_pgoff != 0) + return -EINVAL; + + WARN_ON_ONCE(event->ctx->parent_ctx); + mutex_lock(&event->mmap_mutex); + if (event->output) { + ret = -EINVAL; + goto unlock; + } + + if (atomic_inc_not_zero(&event->mmap_count)) { + if (nr_pages != event->data->nr_pages) + ret = -EINVAL; + goto unlock; + } + + user_extra = nr_pages + 1; + user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10); + + /* + * Increase the limit linearly with more CPUs: + */ + user_lock_limit *= num_online_cpus(); + + user_locked = atomic_long_read(&user->locked_vm) + user_extra; + + extra = 0; + if (user_locked > user_lock_limit) + extra = user_locked - user_lock_limit; + + lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; + lock_limit >>= PAGE_SHIFT; + locked = vma->vm_mm->locked_vm + extra; + + if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() && + !capable(CAP_IPC_LOCK)) { + ret = -EPERM; + goto unlock; + } + + WARN_ON(event->data); + ret = perf_mmap_data_alloc(event, nr_pages); + if (ret) + goto unlock; + + atomic_set(&event->mmap_count, 1); + atomic_long_add(user_extra, &user->locked_vm); + vma->vm_mm->locked_vm += extra; + event->data->nr_locked = extra; + if (vma->vm_flags & VM_WRITE) + event->data->writable = 1; + +unlock: + mutex_unlock(&event->mmap_mutex); + + vma->vm_flags |= VM_RESERVED; + vma->vm_ops = &perf_mmap_vmops; + + return ret; +} + +static int perf_fasync(int fd, struct file *filp, int on) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + struct perf_event *event = filp->private_data; + int retval; + + mutex_lock(&inode->i_mutex); + retval = fasync_helper(fd, filp, on, &event->fasync); + mutex_unlock(&inode->i_mutex); + + if (retval < 0) + return retval; + + return 0; +} + +static const struct file_operations perf_fops = { + .release = perf_release, + .read = perf_read, + .poll = perf_poll, + .unlocked_ioctl = perf_ioctl, + .compat_ioctl = perf_ioctl, + .mmap = perf_mmap, + .fasync = perf_fasync, +}; + +/* + * Perf event wakeup + * + * If there's data, ensure we set the poll() state and publish everything + * to user-space before waking everybody up. + */ + +void perf_event_wakeup(struct perf_event *event) +{ + wake_up_all(&event->waitq); + + if (event->pending_kill) { + kill_fasync(&event->fasync, SIGIO, event->pending_kill); + event->pending_kill = 0; + } +} + +/* + * Pending wakeups + * + * Handle the case where we need to wakeup up from NMI (or rq->lock) context. + * + * The NMI bit means we cannot possibly take locks. Therefore, maintain a + * single linked list and use cmpxchg() to add entries lockless. + */ + +static void perf_pending_event(struct perf_pending_entry *entry) +{ + struct perf_event *event = container_of(entry, + struct perf_event, pending); + + if (event->pending_disable) { + event->pending_disable = 0; + __perf_event_disable(event); + } + + if (event->pending_wakeup) { + event->pending_wakeup = 0; + perf_event_wakeup(event); + } +} + +#define PENDING_TAIL ((struct perf_pending_entry *)-1UL) + +static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = { + PENDING_TAIL, +}; + +static void perf_pending_queue(struct perf_pending_entry *entry, + void (*func)(struct perf_pending_entry *)) +{ + struct perf_pending_entry **head; + + if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL) + return; + + entry->func = func; + + head = &get_cpu_var(perf_pending_head); + + do { + entry->next = *head; + } while (cmpxchg(head, entry->next, entry) != entry->next); + + set_perf_event_pending(); + + put_cpu_var(perf_pending_head); +} + +static int __perf_pending_run(void) +{ + struct perf_pending_entry *list; + int nr = 0; + + list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL); + while (list != PENDING_TAIL) { + void (*func)(struct perf_pending_entry *); + struct perf_pending_entry *entry = list; + + list = list->next; + + func = entry->func; + entry->next = NULL; + /* + * Ensure we observe the unqueue before we issue the wakeup, + * so that we won't be waiting forever. + * -- see perf_not_pending(). + */ + smp_wmb(); + + func(entry); + nr++; + } + + return nr; +} + +static inline int perf_not_pending(struct perf_event *event) +{ + /* + * If we flush on whatever cpu we run, there is a chance we don't + * need to wait. + */ + get_cpu(); + __perf_pending_run(); + put_cpu(); + + /* + * Ensure we see the proper queue state before going to sleep + * so that we do not miss the wakeup. -- see perf_pending_handle() + */ + smp_rmb(); + return event->pending.next == NULL; +} + +static void perf_pending_sync(struct perf_event *event) +{ + wait_event(event->waitq, perf_not_pending(event)); +} + +void perf_event_do_pending(void) +{ + __perf_pending_run(); +} + +/* + * Callchain support -- arch specific + */ + +__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) +{ + return NULL; +} + +/* + * Output + */ +static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail, + unsigned long offset, unsigned long head) +{ + unsigned long mask; + + if (!data->writable) + return true; + + mask = (data->nr_pages << PAGE_SHIFT) - 1; + + offset = (offset - tail) & mask; + head = (head - tail) & mask; + + if ((int)(head - offset) < 0) + return false; + + return true; +} + +static void perf_output_wakeup(struct perf_output_handle *handle) +{ + atomic_set(&handle->data->poll, POLL_IN); + + if (handle->nmi) { + handle->event->pending_wakeup = 1; + perf_pending_queue(&handle->event->pending, + perf_pending_event); + } else + perf_event_wakeup(handle->event); +} + +/* + * Curious locking construct. + * + * We need to ensure a later event_id doesn't publish a head when a former + * event_id isn't done writing. However since we need to deal with NMIs we + * cannot fully serialize things. + * + * What we do is serialize between CPUs so we only have to deal with NMI + * nesting on a single CPU. + * + * We only publish the head (and generate a wakeup) when the outer-most + * event_id completes. + */ +static void perf_output_lock(struct perf_output_handle *handle) +{ + struct perf_mmap_data *data = handle->data; + int cpu; + + handle->locked = 0; + + local_irq_save(handle->flags); + cpu = smp_processor_id(); + + if (in_nmi() && atomic_read(&data->lock) == cpu) + return; + + while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) + cpu_relax(); + + handle->locked = 1; +} + +static void perf_output_unlock(struct perf_output_handle *handle) +{ + struct perf_mmap_data *data = handle->data; + unsigned long head; + int cpu; + + data->done_head = data->head; + + if (!handle->locked) + goto out; + +again: + /* + * The xchg implies a full barrier that ensures all writes are done + * before we publish the new head, matched by a rmb() in userspace when + * reading this position. + */ + while ((head = atomic_long_xchg(&data->done_head, 0))) + data->user_page->data_head = head; + + /* + * NMI can happen here, which means we can miss a done_head update. + */ + + cpu = atomic_xchg(&data->lock, -1); + WARN_ON_ONCE(cpu != smp_processor_id()); + + /* + * Therefore we have to validate we did not indeed do so. + */ + if (unlikely(atomic_long_read(&data->done_head))) { + /* + * Since we had it locked, we can lock it again. + */ + while (atomic_cmpxchg(&data->lock, -1, cpu) != -1) + cpu_relax(); + + goto again; + } + + if (atomic_xchg(&data->wakeup, 0)) + perf_output_wakeup(handle); +out: + local_irq_restore(handle->flags); +} + +void perf_output_copy(struct perf_output_handle *handle, + const void *buf, unsigned int len) +{ + unsigned int pages_mask; + unsigned int offset; + unsigned int size; + void **pages; + + offset = handle->offset; + pages_mask = handle->data->nr_pages - 1; + pages = handle->data->data_pages; + + do { + unsigned int page_offset; + int nr; + + nr = (offset >> PAGE_SHIFT) & pages_mask; + page_offset = offset & (PAGE_SIZE - 1); + size = min_t(unsigned int, PAGE_SIZE - page_offset, len); + + memcpy(pages[nr] + page_offset, buf, size); + + len -= size; + buf += size; + offset += size; + } while (len); + + handle->offset = offset; + + /* + * Check we didn't copy past our reservation window, taking the + * possible unsigned int wrap into account. + */ + WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0); +} + +int perf_output_begin(struct perf_output_handle *handle, + struct perf_event *event, unsigned int size, + int nmi, int sample) +{ + struct perf_event *output_event; + struct perf_mmap_data *data; + unsigned long tail, offset, head; + int have_lost; + struct { + struct perf_event_header header; + u64 id; + u64 lost; + } lost_event; + + rcu_read_lock(); + /* + * For inherited events we send all the output towards the parent. + */ + if (event->parent) + event = event->parent; + + output_event = rcu_dereference(event->output); + if (output_event) + event = output_event; + + data = rcu_dereference(event->data); + if (!data) + goto out; + + handle->data = data; + handle->event = event; + handle->nmi = nmi; + handle->sample = sample; + + if (!data->nr_pages) + goto fail; + + have_lost = atomic_read(&data->lost); + if (have_lost) + size += sizeof(lost_event); + + perf_output_lock(handle); + + do { + /* + * Userspace could choose to issue a mb() before updating the + * tail pointer. So that all reads will be completed before the + * write is issued. + */ + tail = ACCESS_ONCE(data->user_page->data_tail); + smp_rmb(); + offset = head = atomic_long_read(&data->head); + head += size; + if (unlikely(!perf_output_space(data, tail, offset, head))) + goto fail; + } while (atomic_long_cmpxchg(&data->head, offset, head) != offset); + + handle->offset = offset; + handle->head = head; + + if (head - tail > data->watermark) + atomic_set(&data->wakeup, 1); + + if (have_lost) { + lost_event.header.type = PERF_RECORD_LOST; + lost_event.header.misc = 0; + lost_event.header.size = sizeof(lost_event); + lost_event.id = event->id; + lost_event.lost = atomic_xchg(&data->lost, 0); + + perf_output_put(handle, lost_event); + } + + return 0; + +fail: + atomic_inc(&data->lost); + perf_output_unlock(handle); +out: + rcu_read_unlock(); + + return -ENOSPC; +} + +void perf_output_end(struct perf_output_handle *handle) +{ + struct perf_event *event = handle->event; + struct perf_mmap_data *data = handle->data; + + int wakeup_events = event->attr.wakeup_events; + + if (handle->sample && wakeup_events) { + int events = atomic_inc_return(&data->events); + if (events >= wakeup_events) { + atomic_sub(wakeup_events, &data->events); + atomic_set(&data->wakeup, 1); + } + } + + perf_output_unlock(handle); + rcu_read_unlock(); +} + +static u32 perf_event_pid(struct perf_event *event, struct task_struct *p) +{ + /* + * only top level events have the pid namespace they were created in + */ + if (event->parent) + event = event->parent; + + return task_tgid_nr_ns(p, event->ns); +} + +static u32 perf_event_tid(struct perf_event *event, struct task_struct *p) +{ + /* + * only top level events have the pid namespace they were created in + */ + if (event->parent) + event = event->parent; + + return task_pid_nr_ns(p, event->ns); +} + +static void perf_output_read_one(struct perf_output_handle *handle, + struct perf_event *event) +{ + u64 read_format = event->attr.read_format; + u64 values[4]; + int n = 0; + + values[n++] = atomic64_read(&event->count); + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) { + values[n++] = event->total_time_enabled + + atomic64_read(&event->child_total_time_enabled); + } + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) { + values[n++] = event->total_time_running + + atomic64_read(&event->child_total_time_running); + } + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(event); + + perf_output_copy(handle, values, n * sizeof(u64)); +} + +/* + * XXX PERF_FORMAT_GROUP vs inherited events seems difficult. + */ +static void perf_output_read_group(struct perf_output_handle *handle, + struct perf_event *event) +{ + struct perf_event *leader = event->group_leader, *sub; + u64 read_format = event->attr.read_format; + u64 values[5]; + int n = 0; + + values[n++] = 1 + leader->nr_siblings; + + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) + values[n++] = leader->total_time_enabled; + + if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) + values[n++] = leader->total_time_running; + + if (leader != event) + leader->pmu->read(leader); + + values[n++] = atomic64_read(&leader->count); + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(leader); + + perf_output_copy(handle, values, n * sizeof(u64)); + + list_for_each_entry(sub, &leader->sibling_list, group_entry) { + n = 0; + + if (sub != event) + sub->pmu->read(sub); + + values[n++] = atomic64_read(&sub->count); + if (read_format & PERF_FORMAT_ID) + values[n++] = primary_event_id(sub); + + perf_output_copy(handle, values, n * sizeof(u64)); + } +} + +static void perf_output_read(struct perf_output_handle *handle, + struct perf_event *event) +{ + if (event->attr.read_format & PERF_FORMAT_GROUP) + perf_output_read_group(handle, event); + else + perf_output_read_one(handle, event); +} + +void perf_output_sample(struct perf_output_handle *handle, + struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_event *event) +{ + u64 sample_type = data->type; + + perf_output_put(handle, *header); + + if (sample_type & PERF_SAMPLE_IP) + perf_output_put(handle, data->ip); + + if (sample_type & PERF_SAMPLE_TID) + perf_output_put(handle, data->tid_entry); + + if (sample_type & PERF_SAMPLE_TIME) + perf_output_put(handle, data->time); + + if (sample_type & PERF_SAMPLE_ADDR) + perf_output_put(handle, data->addr); + + if (sample_type & PERF_SAMPLE_ID) + perf_output_put(handle, data->id); + + if (sample_type & PERF_SAMPLE_STREAM_ID) + perf_output_put(handle, data->stream_id); + + if (sample_type & PERF_SAMPLE_CPU) + perf_output_put(handle, data->cpu_entry); + + if (sample_type & PERF_SAMPLE_PERIOD) + perf_output_put(handle, data->period); + + if (sample_type & PERF_SAMPLE_READ) + perf_output_read(handle, event); + + if (sample_type & PERF_SAMPLE_CALLCHAIN) { + if (data->callchain) { + int size = 1; + + if (data->callchain) + size += data->callchain->nr; + + size *= sizeof(u64); + + perf_output_copy(handle, data->callchain, size); + } else { + u64 nr = 0; + perf_output_put(handle, nr); + } + } + + if (sample_type & PERF_SAMPLE_RAW) { + if (data->raw) { + perf_output_put(handle, data->raw->size); + perf_output_copy(handle, data->raw->data, + data->raw->size); + } else { + struct { + u32 size; + u32 data; + } raw = { + .size = sizeof(u32), + .data = 0, + }; + perf_output_put(handle, raw); + } + } +} + +void perf_prepare_sample(struct perf_event_header *header, + struct perf_sample_data *data, + struct perf_event *event, + struct pt_regs *regs) +{ + u64 sample_type = event->attr.sample_type; + + data->type = sample_type; + + header->type = PERF_RECORD_SAMPLE; + header->size = sizeof(*header); + + header->misc = 0; + header->misc |= perf_misc_flags(regs); + + if (sample_type & PERF_SAMPLE_IP) { + data->ip = perf_instruction_pointer(regs); + + header->size += sizeof(data->ip); + } + + if (sample_type & PERF_SAMPLE_TID) { + /* namespace issues */ + data->tid_entry.pid = perf_event_pid(event, current); + data->tid_entry.tid = perf_event_tid(event, current); + + header->size += sizeof(data->tid_entry); + } + + if (sample_type & PERF_SAMPLE_TIME) { + data->time = perf_clock(); + + header->size += sizeof(data->time); + } + + if (sample_type & PERF_SAMPLE_ADDR) + header->size += sizeof(data->addr); + + if (sample_type & PERF_SAMPLE_ID) { + data->id = primary_event_id(event); + + header->size += sizeof(data->id); + } + + if (sample_type & PERF_SAMPLE_STREAM_ID) { + data->stream_id = event->id; + + header->size += sizeof(data->stream_id); + } + + if (sample_type & PERF_SAMPLE_CPU) { + data->cpu_entry.cpu = raw_smp_processor_id(); + data->cpu_entry.reserved = 0; + + header->size += sizeof(data->cpu_entry); + } + + if (sample_type & PERF_SAMPLE_PERIOD) + header->size += sizeof(data->period); + + if (sample_type & PERF_SAMPLE_READ) + header->size += perf_event_read_size(event); + + if (sample_type & PERF_SAMPLE_CALLCHAIN) { + int size = 1; + + data->callchain = perf_callchain(regs); + + if (data->callchain) + size += data->callchain->nr; + + header->size += size * sizeof(u64); + } + + if (sample_type & PERF_SAMPLE_RAW) { + int size = sizeof(u32); + + if (data->raw) + size += data->raw->size; + else + size += sizeof(u32); + + WARN_ON_ONCE(size & (sizeof(u64)-1)); + header->size += size; + } +} + +static void perf_event_output(struct perf_event *event, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_output_handle handle; + struct perf_event_header header; + + perf_prepare_sample(&header, data, event, regs); + + if (perf_output_begin(&handle, event, header.size, nmi, 1)) + return; + + perf_output_sample(&handle, &header, data, event); + + perf_output_end(&handle); +} + +/* + * read event_id + */ + +struct perf_read_event { + struct perf_event_header header; + + u32 pid; + u32 tid; +}; + +static void +perf_event_read_event(struct perf_event *event, + struct task_struct *task) +{ + struct perf_output_handle handle; + struct perf_read_event read_event = { + .header = { + .type = PERF_RECORD_READ, + .misc = 0, + .size = sizeof(read_event) + perf_event_read_size(event), + }, + .pid = perf_event_pid(event, task), + .tid = perf_event_tid(event, task), + }; + int ret; + + ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0); + if (ret) + return; + + perf_output_put(&handle, read_event); + perf_output_read(&handle, event); + + perf_output_end(&handle); +} + +/* + * task tracking -- fork/exit + * + * enabled by: attr.comm | attr.mmap | attr.task + */ + +struct perf_task_event { + struct task_struct *task; + struct perf_event_context *task_ctx; + + struct { + struct perf_event_header header; + + u32 pid; + u32 ppid; + u32 tid; + u32 ptid; + u64 time; + } event_id; +}; + +static void perf_event_task_output(struct perf_event *event, + struct perf_task_event *task_event) +{ + struct perf_output_handle handle; + int size; + struct task_struct *task = task_event->task; + int ret; + + size = task_event->event_id.header.size; + ret = perf_output_begin(&handle, event, size, 0, 0); + + if (ret) + return; + + task_event->event_id.pid = perf_event_pid(event, task); + task_event->event_id.ppid = perf_event_pid(event, current); + + task_event->event_id.tid = perf_event_tid(event, task); + task_event->event_id.ptid = perf_event_tid(event, current); + + task_event->event_id.time = perf_clock(); + + perf_output_put(&handle, task_event->event_id); + + perf_output_end(&handle); +} + +static int perf_event_task_match(struct perf_event *event) +{ + if (event->attr.comm || event->attr.mmap || event->attr.task) + return 1; + + return 0; +} + +static void perf_event_task_ctx(struct perf_event_context *ctx, + struct perf_task_event *task_event) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_event_task_match(event)) + perf_event_task_output(event, task_event); + } + rcu_read_unlock(); +} + +static void perf_event_task_event(struct perf_task_event *task_event) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx = task_event->task_ctx; + + cpuctx = &get_cpu_var(perf_cpu_context); + perf_event_task_ctx(&cpuctx->ctx, task_event); + put_cpu_var(perf_cpu_context); + + rcu_read_lock(); + if (!ctx) + ctx = rcu_dereference(task_event->task->perf_event_ctxp); + if (ctx) + perf_event_task_ctx(ctx, task_event); + rcu_read_unlock(); +} + +static void perf_event_task(struct task_struct *task, + struct perf_event_context *task_ctx, + int new) +{ + struct perf_task_event task_event; + + if (!atomic_read(&nr_comm_events) && + !atomic_read(&nr_mmap_events) && + !atomic_read(&nr_task_events)) + return; + + task_event = (struct perf_task_event){ + .task = task, + .task_ctx = task_ctx, + .event_id = { + .header = { + .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT, + .misc = 0, + .size = sizeof(task_event.event_id), + }, + /* .pid */ + /* .ppid */ + /* .tid */ + /* .ptid */ + }, + }; + + perf_event_task_event(&task_event); +} + +void perf_event_fork(struct task_struct *task) +{ + perf_event_task(task, NULL, 1); +} + +/* + * comm tracking + */ + +struct perf_comm_event { + struct task_struct *task; + char *comm; + int comm_size; + + struct { + struct perf_event_header header; + + u32 pid; + u32 tid; + } event_id; +}; + +static void perf_event_comm_output(struct perf_event *event, + struct perf_comm_event *comm_event) +{ + struct perf_output_handle handle; + int size = comm_event->event_id.header.size; + int ret = perf_output_begin(&handle, event, size, 0, 0); + + if (ret) + return; + + comm_event->event_id.pid = perf_event_pid(event, comm_event->task); + comm_event->event_id.tid = perf_event_tid(event, comm_event->task); + + perf_output_put(&handle, comm_event->event_id); + perf_output_copy(&handle, comm_event->comm, + comm_event->comm_size); + perf_output_end(&handle); +} + +static int perf_event_comm_match(struct perf_event *event) +{ + if (event->attr.comm) + return 1; + + return 0; +} + +static void perf_event_comm_ctx(struct perf_event_context *ctx, + struct perf_comm_event *comm_event) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_event_comm_match(event)) + perf_event_comm_output(event, comm_event); + } + rcu_read_unlock(); +} + +static void perf_event_comm_event(struct perf_comm_event *comm_event) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; + unsigned int size; + char comm[TASK_COMM_LEN]; + + memset(comm, 0, sizeof(comm)); + strncpy(comm, comm_event->task->comm, sizeof(comm)); + size = ALIGN(strlen(comm)+1, sizeof(u64)); + + comm_event->comm = comm; + comm_event->comm_size = size; + + comm_event->event_id.header.size = sizeof(comm_event->event_id) + size; + + cpuctx = &get_cpu_var(perf_cpu_context); + perf_event_comm_ctx(&cpuctx->ctx, comm_event); + put_cpu_var(perf_cpu_context); + + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_event_ctxp); + if (ctx) + perf_event_comm_ctx(ctx, comm_event); + rcu_read_unlock(); +} + +void perf_event_comm(struct task_struct *task) +{ + struct perf_comm_event comm_event; + + if (task->perf_event_ctxp) + perf_event_enable_on_exec(task); + + if (!atomic_read(&nr_comm_events)) + return; + + comm_event = (struct perf_comm_event){ + .task = task, + /* .comm */ + /* .comm_size */ + .event_id = { + .header = { + .type = PERF_RECORD_COMM, + .misc = 0, + /* .size */ + }, + /* .pid */ + /* .tid */ + }, + }; + + perf_event_comm_event(&comm_event); +} + +/* + * mmap tracking + */ + +struct perf_mmap_event { + struct vm_area_struct *vma; + + const char *file_name; + int file_size; + + struct { + struct perf_event_header header; + + u32 pid; + u32 tid; + u64 start; + u64 len; + u64 pgoff; + } event_id; +}; + +static void perf_event_mmap_output(struct perf_event *event, + struct perf_mmap_event *mmap_event) +{ + struct perf_output_handle handle; + int size = mmap_event->event_id.header.size; + int ret = perf_output_begin(&handle, event, size, 0, 0); + + if (ret) + return; + + mmap_event->event_id.pid = perf_event_pid(event, current); + mmap_event->event_id.tid = perf_event_tid(event, current); + + perf_output_put(&handle, mmap_event->event_id); + perf_output_copy(&handle, mmap_event->file_name, + mmap_event->file_size); + perf_output_end(&handle); +} + +static int perf_event_mmap_match(struct perf_event *event, + struct perf_mmap_event *mmap_event) +{ + if (event->attr.mmap) + return 1; + + return 0; +} + +static void perf_event_mmap_ctx(struct perf_event_context *ctx, + struct perf_mmap_event *mmap_event) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_event_mmap_match(event, mmap_event)) + perf_event_mmap_output(event, mmap_event); + } + rcu_read_unlock(); +} + +static void perf_event_mmap_event(struct perf_mmap_event *mmap_event) +{ + struct perf_cpu_context *cpuctx; + struct perf_event_context *ctx; + struct vm_area_struct *vma = mmap_event->vma; + struct file *file = vma->vm_file; + unsigned int size; + char tmp[16]; + char *buf = NULL; + const char *name; + + memset(tmp, 0, sizeof(tmp)); + + if (file) { + /* + * d_path works from the end of the buffer backwards, so we + * need to add enough zero bytes after the string to handle + * the 64bit alignment we do later. + */ + buf = kzalloc(PATH_MAX + sizeof(u64), GFP_KERNEL); + if (!buf) { + name = strncpy(tmp, "//enomem", sizeof(tmp)); + goto got_name; + } + name = d_path(&file->f_path, buf, PATH_MAX); + if (IS_ERR(name)) { + name = strncpy(tmp, "//toolong", sizeof(tmp)); + goto got_name; + } + } else { + if (arch_vma_name(mmap_event->vma)) { + name = strncpy(tmp, arch_vma_name(mmap_event->vma), + sizeof(tmp)); + goto got_name; + } + + if (!vma->vm_mm) { + name = strncpy(tmp, "[vdso]", sizeof(tmp)); + goto got_name; + } + + name = strncpy(tmp, "//anon", sizeof(tmp)); + goto got_name; + } + +got_name: + size = ALIGN(strlen(name)+1, sizeof(u64)); + + mmap_event->file_name = name; + mmap_event->file_size = size; + + mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size; + + cpuctx = &get_cpu_var(perf_cpu_context); + perf_event_mmap_ctx(&cpuctx->ctx, mmap_event); + put_cpu_var(perf_cpu_context); + + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_event_ctxp); + if (ctx) + perf_event_mmap_ctx(ctx, mmap_event); + rcu_read_unlock(); + + kfree(buf); +} + +void __perf_event_mmap(struct vm_area_struct *vma) +{ + struct perf_mmap_event mmap_event; + + if (!atomic_read(&nr_mmap_events)) + return; + + mmap_event = (struct perf_mmap_event){ + .vma = vma, + /* .file_name */ + /* .file_size */ + .event_id = { + .header = { + .type = PERF_RECORD_MMAP, + .misc = 0, + /* .size */ + }, + /* .pid */ + /* .tid */ + .start = vma->vm_start, + .len = vma->vm_end - vma->vm_start, + .pgoff = vma->vm_pgoff, + }, + }; + + perf_event_mmap_event(&mmap_event); +} + +/* + * IRQ throttle logging + */ + +static void perf_log_throttle(struct perf_event *event, int enable) +{ + struct perf_output_handle handle; + int ret; + + struct { + struct perf_event_header header; + u64 time; + u64 id; + u64 stream_id; + } throttle_event = { + .header = { + .type = PERF_RECORD_THROTTLE, + .misc = 0, + .size = sizeof(throttle_event), + }, + .time = perf_clock(), + .id = primary_event_id(event), + .stream_id = event->id, + }; + + if (enable) + throttle_event.header.type = PERF_RECORD_UNTHROTTLE; + + ret = perf_output_begin(&handle, event, sizeof(throttle_event), 1, 0); + if (ret) + return; + + perf_output_put(&handle, throttle_event); + perf_output_end(&handle); +} + +/* + * Generic event overflow handling, sampling. + */ + +static int __perf_event_overflow(struct perf_event *event, int nmi, + int throttle, struct perf_sample_data *data, + struct pt_regs *regs) +{ + int events = atomic_read(&event->event_limit); + struct hw_perf_event *hwc = &event->hw; + int ret = 0; + + throttle = (throttle && event->pmu->unthrottle != NULL); + + if (!throttle) { + hwc->interrupts++; + } else { + if (hwc->interrupts != MAX_INTERRUPTS) { + hwc->interrupts++; + if (HZ * hwc->interrupts > + (u64)sysctl_perf_event_sample_rate) { + hwc->interrupts = MAX_INTERRUPTS; + perf_log_throttle(event, 0); + ret = 1; + } + } else { + /* + * Keep re-disabling events even though on the previous + * pass we disabled it - just in case we raced with a + * sched-in and the event got enabled again: + */ + ret = 1; + } + } + + if (event->attr.freq) { + u64 now = perf_clock(); + s64 delta = now - hwc->freq_stamp; + + hwc->freq_stamp = now; + + if (delta > 0 && delta < TICK_NSEC) + perf_adjust_period(event, NSEC_PER_SEC / (int)delta); + } + + /* + * XXX event_limit might not quite work as expected on inherited + * events + */ + + event->pending_kill = POLL_IN; + if (events && atomic_dec_and_test(&event->event_limit)) { + ret = 1; + event->pending_kill = POLL_HUP; + if (nmi) { + event->pending_disable = 1; + perf_pending_queue(&event->pending, + perf_pending_event); + } else + perf_event_disable(event); + } + + perf_event_output(event, nmi, data, regs); + return ret; +} + +int perf_event_overflow(struct perf_event *event, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + return __perf_event_overflow(event, nmi, 1, data, regs); +} + +/* + * Generic software event infrastructure + */ + +/* + * We directly increment event->count and keep a second value in + * event->hw.period_left to count intervals. This period event + * is kept in the range [-sample_period, 0] so that we can use the + * sign as trigger. + */ + +static u64 perf_swevent_set_period(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + u64 period = hwc->last_period; + u64 nr, offset; + s64 old, val; + + hwc->last_period = hwc->sample_period; + +again: + old = val = atomic64_read(&hwc->period_left); + if (val < 0) + return 0; + + nr = div64_u64(period + val, period); + offset = nr * period; + val -= offset; + if (atomic64_cmpxchg(&hwc->period_left, old, val) != old) + goto again; + + return nr; +} + +static void perf_swevent_overflow(struct perf_event *event, + int nmi, struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct hw_perf_event *hwc = &event->hw; + int throttle = 0; + u64 overflow; + + data->period = event->hw.last_period; + overflow = perf_swevent_set_period(event); + + if (hwc->interrupts == MAX_INTERRUPTS) + return; + + for (; overflow; overflow--) { + if (__perf_event_overflow(event, nmi, throttle, + data, regs)) { + /* + * We inhibit the overflow from happening when + * hwc->interrupts == MAX_INTERRUPTS. + */ + break; + } + throttle = 1; + } +} + +static void perf_swevent_unthrottle(struct perf_event *event) +{ + /* + * Nothing to do, we already reset hwc->interrupts. + */ +} + +static void perf_swevent_add(struct perf_event *event, u64 nr, + int nmi, struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct hw_perf_event *hwc = &event->hw; + + atomic64_add(nr, &event->count); + + if (!hwc->sample_period) + return; + + if (!regs) + return; + + if (!atomic64_add_negative(nr, &hwc->period_left)) + perf_swevent_overflow(event, nmi, data, regs); +} + +static int perf_swevent_is_counting(struct perf_event *event) +{ + /* + * The event is active, we're good! + */ + if (event->state == PERF_EVENT_STATE_ACTIVE) + return 1; + + /* + * The event is off/error, not counting. + */ + if (event->state != PERF_EVENT_STATE_INACTIVE) + return 0; + + /* + * The event is inactive, if the context is active + * we're part of a group that didn't make it on the 'pmu', + * not counting. + */ + if (event->ctx->is_active) + return 0; + + /* + * We're inactive and the context is too, this means the + * task is scheduled out, we're counting events that happen + * to us, like migration events. + */ + return 1; +} + +static int perf_swevent_match(struct perf_event *event, + enum perf_type_id type, + u32 event_id, struct pt_regs *regs) +{ + if (!perf_swevent_is_counting(event)) + return 0; + + if (event->attr.type != type) + return 0; + if (event->attr.config != event_id) + return 0; + + if (regs) { + if (event->attr.exclude_user && user_mode(regs)) + return 0; + + if (event->attr.exclude_kernel && !user_mode(regs)) + return 0; + } + + return 1; +} + +static void perf_swevent_ctx_event(struct perf_event_context *ctx, + enum perf_type_id type, + u32 event_id, u64 nr, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_event *event; + + if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list)) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(event, &ctx->event_list, event_entry) { + if (perf_swevent_match(event, type, event_id, regs)) + perf_swevent_add(event, nr, nmi, data, regs); + } + rcu_read_unlock(); +} + +static int *perf_swevent_recursion_context(struct perf_cpu_context *cpuctx) +{ + if (in_nmi()) + return &cpuctx->recursion[3]; + + if (in_irq()) + return &cpuctx->recursion[2]; + + if (in_softirq()) + return &cpuctx->recursion[1]; + + return &cpuctx->recursion[0]; +} + +static void do_perf_sw_event(enum perf_type_id type, u32 event_id, + u64 nr, int nmi, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct perf_cpu_context *cpuctx = &get_cpu_var(perf_cpu_context); + int *recursion = perf_swevent_recursion_context(cpuctx); + struct perf_event_context *ctx; + + if (*recursion) + goto out; + + (*recursion)++; + barrier(); + + perf_swevent_ctx_event(&cpuctx->ctx, type, event_id, + nr, nmi, data, regs); + rcu_read_lock(); + /* + * doesn't really matter which of the child contexts the + * events ends up in. + */ + ctx = rcu_dereference(current->perf_event_ctxp); + if (ctx) + perf_swevent_ctx_event(ctx, type, event_id, nr, nmi, data, regs); + rcu_read_unlock(); + + barrier(); + (*recursion)--; + +out: + put_cpu_var(perf_cpu_context); +} + +void __perf_sw_event(u32 event_id, u64 nr, int nmi, + struct pt_regs *regs, u64 addr) +{ + struct perf_sample_data data = { + .addr = addr, + }; + + do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, nmi, + &data, regs); +} + +static void perf_swevent_read(struct perf_event *event) +{ +} + +static int perf_swevent_enable(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + + if (hwc->sample_period) { + hwc->last_period = hwc->sample_period; + perf_swevent_set_period(event); + } + return 0; +} + +static void perf_swevent_disable(struct perf_event *event) +{ +} + +static const struct pmu perf_ops_generic = { + .enable = perf_swevent_enable, + .disable = perf_swevent_disable, + .read = perf_swevent_read, + .unthrottle = perf_swevent_unthrottle, +}; + +/* + * hrtimer based swevent callback + */ + +static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer) +{ + enum hrtimer_restart ret = HRTIMER_RESTART; + struct perf_sample_data data; + struct pt_regs *regs; + struct perf_event *event; + u64 period; + + event = container_of(hrtimer, struct perf_event, hw.hrtimer); + event->pmu->read(event); + + data.addr = 0; + regs = get_irq_regs(); + /* + * In case we exclude kernel IPs or are somehow not in interrupt + * context, provide the next best thing, the user IP. + */ + if ((event->attr.exclude_kernel || !regs) && + !event->attr.exclude_user) + regs = task_pt_regs(current); + + if (regs) { + if (perf_event_overflow(event, 0, &data, regs)) + ret = HRTIMER_NORESTART; + } + + period = max_t(u64, 10000, event->hw.sample_period); + hrtimer_forward_now(hrtimer, ns_to_ktime(period)); + + return ret; +} + +/* + * Software event: cpu wall time clock + */ + +static void cpu_clock_perf_event_update(struct perf_event *event) +{ + int cpu = raw_smp_processor_id(); + s64 prev; + u64 now; + + now = cpu_clock(cpu); + prev = atomic64_read(&event->hw.prev_count); + atomic64_set(&event->hw.prev_count, now); + atomic64_add(now - prev, &event->count); +} + +static int cpu_clock_perf_event_enable(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + int cpu = raw_smp_processor_id(); + + atomic64_set(&hwc->prev_count, cpu_clock(cpu)); + hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hwc->hrtimer.function = perf_swevent_hrtimer; + if (hwc->sample_period) { + u64 period = max_t(u64, 10000, hwc->sample_period); + __hrtimer_start_range_ns(&hwc->hrtimer, + ns_to_ktime(period), 0, + HRTIMER_MODE_REL, 0); + } + + return 0; +} + +static void cpu_clock_perf_event_disable(struct perf_event *event) +{ + if (event->hw.sample_period) + hrtimer_cancel(&event->hw.hrtimer); + cpu_clock_perf_event_update(event); +} + +static void cpu_clock_perf_event_read(struct perf_event *event) +{ + cpu_clock_perf_event_update(event); +} + +static const struct pmu perf_ops_cpu_clock = { + .enable = cpu_clock_perf_event_enable, + .disable = cpu_clock_perf_event_disable, + .read = cpu_clock_perf_event_read, +}; + +/* + * Software event: task time clock + */ + +static void task_clock_perf_event_update(struct perf_event *event, u64 now) +{ + u64 prev; + s64 delta; + + prev = atomic64_xchg(&event->hw.prev_count, now); + delta = now - prev; + atomic64_add(delta, &event->count); +} + +static int task_clock_perf_event_enable(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + u64 now; + + now = event->ctx->time; + + atomic64_set(&hwc->prev_count, now); + hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hwc->hrtimer.function = perf_swevent_hrtimer; + if (hwc->sample_period) { + u64 period = max_t(u64, 10000, hwc->sample_period); + __hrtimer_start_range_ns(&hwc->hrtimer, + ns_to_ktime(period), 0, + HRTIMER_MODE_REL, 0); + } + + return 0; +} + +static void task_clock_perf_event_disable(struct perf_event *event) +{ + if (event->hw.sample_period) + hrtimer_cancel(&event->hw.hrtimer); + task_clock_perf_event_update(event, event->ctx->time); + +} + +static void task_clock_perf_event_read(struct perf_event *event) +{ + u64 time; + + if (!in_nmi()) { + update_context_time(event->ctx); + time = event->ctx->time; + } else { + u64 now = perf_clock(); + u64 delta = now - event->ctx->timestamp; + time = event->ctx->time + delta; + } + + task_clock_perf_event_update(event, time); +} + +static const struct pmu perf_ops_task_clock = { + .enable = task_clock_perf_event_enable, + .disable = task_clock_perf_event_disable, + .read = task_clock_perf_event_read, +}; + +#ifdef CONFIG_EVENT_PROFILE +void perf_tp_event(int event_id, u64 addr, u64 count, void *record, + int entry_size) +{ + struct perf_raw_record raw = { + .size = entry_size, + .data = record, + }; + + struct perf_sample_data data = { + .addr = addr, + .raw = &raw, + }; + + struct pt_regs *regs = get_irq_regs(); + + if (!regs) + regs = task_pt_regs(current); + + do_perf_sw_event(PERF_TYPE_TRACEPOINT, event_id, count, 1, + &data, regs); +} +EXPORT_SYMBOL_GPL(perf_tp_event); + +extern int ftrace_profile_enable(int); +extern void ftrace_profile_disable(int); + +static void tp_perf_event_destroy(struct perf_event *event) +{ + ftrace_profile_disable(event->attr.config); +} + +static const struct pmu *tp_perf_event_init(struct perf_event *event) +{ + /* + * Raw tracepoint data is a severe data leak, only allow root to + * have these. + */ + if ((event->attr.sample_type & PERF_SAMPLE_RAW) && + perf_paranoid_tracepoint_raw() && + !capable(CAP_SYS_ADMIN)) + return ERR_PTR(-EPERM); + + if (ftrace_profile_enable(event->attr.config)) + return NULL; + + event->destroy = tp_perf_event_destroy; + + return &perf_ops_generic; +} +#else +static const struct pmu *tp_perf_event_init(struct perf_event *event) +{ + return NULL; +} +#endif + +atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; + +static void sw_perf_event_destroy(struct perf_event *event) +{ + u64 event_id = event->attr.config; + + WARN_ON(event->parent); + + atomic_dec(&perf_swevent_enabled[event_id]); +} + +static const struct pmu *sw_perf_event_init(struct perf_event *event) +{ + const struct pmu *pmu = NULL; + u64 event_id = event->attr.config; + + /* + * Software events (currently) can't in general distinguish + * between user, kernel and hypervisor events. + * However, context switches and cpu migrations are considered + * to be kernel events, and page faults are never hypervisor + * events. + */ + switch (event_id) { + case PERF_COUNT_SW_CPU_CLOCK: + pmu = &perf_ops_cpu_clock; + + break; + case PERF_COUNT_SW_TASK_CLOCK: + /* + * If the user instantiates this as a per-cpu event, + * use the cpu_clock event instead. + */ + if (event->ctx->task) + pmu = &perf_ops_task_clock; + else + pmu = &perf_ops_cpu_clock; + + break; + case PERF_COUNT_SW_PAGE_FAULTS: + case PERF_COUNT_SW_PAGE_FAULTS_MIN: + case PERF_COUNT_SW_PAGE_FAULTS_MAJ: + case PERF_COUNT_SW_CONTEXT_SWITCHES: + case PERF_COUNT_SW_CPU_MIGRATIONS: + if (!event->parent) { + atomic_inc(&perf_swevent_enabled[event_id]); + event->destroy = sw_perf_event_destroy; + } + pmu = &perf_ops_generic; + break; + } + + return pmu; +} + +/* + * Allocate and initialize a event structure + */ +static struct perf_event * +perf_event_alloc(struct perf_event_attr *attr, + int cpu, + struct perf_event_context *ctx, + struct perf_event *group_leader, + struct perf_event *parent_event, + gfp_t gfpflags) +{ + const struct pmu *pmu; + struct perf_event *event; + struct hw_perf_event *hwc; + long err; + + event = kzalloc(sizeof(*event), gfpflags); + if (!event) + return ERR_PTR(-ENOMEM); + + /* + * Single events are their own group leaders, with an + * empty sibling list: + */ + if (!group_leader) + group_leader = event; + + mutex_init(&event->child_mutex); + INIT_LIST_HEAD(&event->child_list); + + INIT_LIST_HEAD(&event->group_entry); + INIT_LIST_HEAD(&event->event_entry); + INIT_LIST_HEAD(&event->sibling_list); + init_waitqueue_head(&event->waitq); + + mutex_init(&event->mmap_mutex); + + event->cpu = cpu; + event->attr = *attr; + event->group_leader = group_leader; + event->pmu = NULL; + event->ctx = ctx; + event->oncpu = -1; + + event->parent = parent_event; + + event->ns = get_pid_ns(current->nsproxy->pid_ns); + event->id = atomic64_inc_return(&perf_event_id); + + event->state = PERF_EVENT_STATE_INACTIVE; + + if (attr->disabled) + event->state = PERF_EVENT_STATE_OFF; + + pmu = NULL; + + hwc = &event->hw; + hwc->sample_period = attr->sample_period; + if (attr->freq && attr->sample_freq) + hwc->sample_period = 1; + hwc->last_period = hwc->sample_period; + + atomic64_set(&hwc->period_left, hwc->sample_period); + + /* + * we currently do not support PERF_FORMAT_GROUP on inherited events + */ + if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP)) + goto done; + + switch (attr->type) { + case PERF_TYPE_RAW: + case PERF_TYPE_HARDWARE: + case PERF_TYPE_HW_CACHE: + pmu = hw_perf_event_init(event); + break; + + case PERF_TYPE_SOFTWARE: + pmu = sw_perf_event_init(event); + break; + + case PERF_TYPE_TRACEPOINT: + pmu = tp_perf_event_init(event); + break; + + default: + break; + } +done: + err = 0; + if (!pmu) + err = -EINVAL; + else if (IS_ERR(pmu)) + err = PTR_ERR(pmu); + + if (err) { + if (event->ns) + put_pid_ns(event->ns); + kfree(event); + return ERR_PTR(err); + } + + event->pmu = pmu; + + if (!event->parent) { + atomic_inc(&nr_events); + if (event->attr.mmap) + atomic_inc(&nr_mmap_events); + if (event->attr.comm) + atomic_inc(&nr_comm_events); + if (event->attr.task) + atomic_inc(&nr_task_events); + } + + return event; +} + +static int perf_copy_attr(struct perf_event_attr __user *uattr, + struct perf_event_attr *attr) +{ + u32 size; + int ret; + + if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0)) + return -EFAULT; + + /* + * zero the full structure, so that a short copy will be nice. + */ + memset(attr, 0, sizeof(*attr)); + + ret = get_user(size, &uattr->size); + if (ret) + return ret; + + if (size > PAGE_SIZE) /* silly large */ + goto err_size; + + if (!size) /* abi compat */ + size = PERF_ATTR_SIZE_VER0; + + if (size < PERF_ATTR_SIZE_VER0) + goto err_size; + + /* + * If we're handed a bigger struct than we know of, + * ensure all the unknown bits are 0 - i.e. new + * user-space does not rely on any kernel feature + * extensions we dont know about yet. + */ + if (size > sizeof(*attr)) { + unsigned char __user *addr; + unsigned char __user *end; + unsigned char val; + + addr = (void __user *)uattr + sizeof(*attr); + end = (void __user *)uattr + size; + + for (; addr < end; addr++) { + ret = get_user(val, addr); + if (ret) + return ret; + if (val) + goto err_size; + } + size = sizeof(*attr); + } + + ret = copy_from_user(attr, uattr, size); + if (ret) + return -EFAULT; + + /* + * If the type exists, the corresponding creation will verify + * the attr->config. + */ + if (attr->type >= PERF_TYPE_MAX) + return -EINVAL; + + if (attr->__reserved_1 || attr->__reserved_2 || attr->__reserved_3) + return -EINVAL; + + if (attr->sample_type & ~(PERF_SAMPLE_MAX-1)) + return -EINVAL; + + if (attr->read_format & ~(PERF_FORMAT_MAX-1)) + return -EINVAL; + +out: + return ret; + +err_size: + put_user(sizeof(*attr), &uattr->size); + ret = -E2BIG; + goto out; +} + +int perf_event_set_output(struct perf_event *event, int output_fd) +{ + struct perf_event *output_event = NULL; + struct file *output_file = NULL; + struct perf_event *old_output; + int fput_needed = 0; + int ret = -EINVAL; + + if (!output_fd) + goto set; + + output_file = fget_light(output_fd, &fput_needed); + if (!output_file) + return -EBADF; + + if (output_file->f_op != &perf_fops) + goto out; + + output_event = output_file->private_data; + + /* Don't chain output fds */ + if (output_event->output) + goto out; + + /* Don't set an output fd when we already have an output channel */ + if (event->data) + goto out; + + atomic_long_inc(&output_file->f_count); + +set: + mutex_lock(&event->mmap_mutex); + old_output = event->output; + rcu_assign_pointer(event->output, output_event); + mutex_unlock(&event->mmap_mutex); + + if (old_output) { + /* + * we need to make sure no existing perf_output_*() + * is still referencing this event. + */ + synchronize_rcu(); + fput(old_output->filp); + } + + ret = 0; +out: + fput_light(output_file, fput_needed); + return ret; +} + +/** + * sys_perf_event_open - open a performance event, associate it to a task/cpu + * + * @attr_uptr: event_id type attributes for monitoring/sampling + * @pid: target pid + * @cpu: target cpu + * @group_fd: group leader event fd + */ +SYSCALL_DEFINE5(perf_event_open, + struct perf_event_attr __user *, attr_uptr, + pid_t, pid, int, cpu, int, group_fd, unsigned long, flags) +{ + struct perf_event *event, *group_leader; + struct perf_event_attr attr; + struct perf_event_context *ctx; + struct file *event_file = NULL; + struct file *group_file = NULL; + int fput_needed = 0; + int fput_needed2 = 0; + int err; + + /* for future expandability... */ + if (flags & ~(PERF_FLAG_FD_NO_GROUP | PERF_FLAG_FD_OUTPUT)) + return -EINVAL; + + err = perf_copy_attr(attr_uptr, &attr); + if (err) + return err; + + if (!attr.exclude_kernel) { + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) + return -EACCES; + } + + if (attr.freq) { + if (attr.sample_freq > sysctl_perf_event_sample_rate) + return -EINVAL; + } + + /* + * Get the target context (task or percpu): + */ + ctx = find_get_context(pid, cpu); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + + /* + * Look up the group leader (we will attach this event to it): + */ + group_leader = NULL; + if (group_fd != -1 && !(flags & PERF_FLAG_FD_NO_GROUP)) { + err = -EINVAL; + group_file = fget_light(group_fd, &fput_needed); + if (!group_file) + goto err_put_context; + if (group_file->f_op != &perf_fops) + goto err_put_context; + + group_leader = group_file->private_data; + /* + * Do not allow a recursive hierarchy (this new sibling + * becoming part of another group-sibling): + */ + if (group_leader->group_leader != group_leader) + goto err_put_context; + /* + * Do not allow to attach to a group in a different + * task or CPU context: + */ + if (group_leader->ctx != ctx) + goto err_put_context; + /* + * Only a group leader can be exclusive or pinned + */ + if (attr.exclusive || attr.pinned) + goto err_put_context; + } + + event = perf_event_alloc(&attr, cpu, ctx, group_leader, + NULL, GFP_KERNEL); + err = PTR_ERR(event); + if (IS_ERR(event)) + goto err_put_context; + + err = anon_inode_getfd("[perf_event]", &perf_fops, event, 0); + if (err < 0) + goto err_free_put_context; + + event_file = fget_light(err, &fput_needed2); + if (!event_file) + goto err_free_put_context; + + if (flags & PERF_FLAG_FD_OUTPUT) { + err = perf_event_set_output(event, group_fd); + if (err) + goto err_fput_free_put_context; + } + + event->filp = event_file; + WARN_ON_ONCE(ctx->parent_ctx); + mutex_lock(&ctx->mutex); + perf_install_in_context(ctx, event, cpu); + ++ctx->generation; + mutex_unlock(&ctx->mutex); + + event->owner = current; + get_task_struct(current); + mutex_lock(¤t->perf_event_mutex); + list_add_tail(&event->owner_entry, ¤t->perf_event_list); + mutex_unlock(¤t->perf_event_mutex); + +err_fput_free_put_context: + fput_light(event_file, fput_needed2); + +err_free_put_context: + if (err < 0) + kfree(event); + +err_put_context: + if (err < 0) + put_ctx(ctx); + + fput_light(group_file, fput_needed); + + return err; +} + +/* + * inherit a event from parent task to child task: + */ +static struct perf_event * +inherit_event(struct perf_event *parent_event, + struct task_struct *parent, + struct perf_event_context *parent_ctx, + struct task_struct *child, + struct perf_event *group_leader, + struct perf_event_context *child_ctx) +{ + struct perf_event *child_event; + + /* + * Instead of creating recursive hierarchies of events, + * we link inherited events back to the original parent, + * which has a filp for sure, which we use as the reference + * count: + */ + if (parent_event->parent) + parent_event = parent_event->parent; + + child_event = perf_event_alloc(&parent_event->attr, + parent_event->cpu, child_ctx, + group_leader, parent_event, + GFP_KERNEL); + if (IS_ERR(child_event)) + return child_event; + get_ctx(child_ctx); + + /* + * Make the child state follow the state of the parent event, + * not its attr.disabled bit. We hold the parent's mutex, + * so we won't race with perf_event_{en, dis}able_family. + */ + if (parent_event->state >= PERF_EVENT_STATE_INACTIVE) + child_event->state = PERF_EVENT_STATE_INACTIVE; + else + child_event->state = PERF_EVENT_STATE_OFF; + + if (parent_event->attr.freq) + child_event->hw.sample_period = parent_event->hw.sample_period; + + /* + * Link it up in the child's context: + */ + add_event_to_ctx(child_event, child_ctx); + + /* + * Get a reference to the parent filp - we will fput it + * when the child event exits. This is safe to do because + * we are in the parent and we know that the filp still + * exists and has a nonzero count: + */ + atomic_long_inc(&parent_event->filp->f_count); + + /* + * Link this into the parent event's child list + */ + WARN_ON_ONCE(parent_event->ctx->parent_ctx); + mutex_lock(&parent_event->child_mutex); + list_add_tail(&child_event->child_list, &parent_event->child_list); + mutex_unlock(&parent_event->child_mutex); + + return child_event; +} + +static int inherit_group(struct perf_event *parent_event, + struct task_struct *parent, + struct perf_event_context *parent_ctx, + struct task_struct *child, + struct perf_event_context *child_ctx) +{ + struct perf_event *leader; + struct perf_event *sub; + struct perf_event *child_ctr; + + leader = inherit_event(parent_event, parent, parent_ctx, + child, NULL, child_ctx); + if (IS_ERR(leader)) + return PTR_ERR(leader); + list_for_each_entry(sub, &parent_event->sibling_list, group_entry) { + child_ctr = inherit_event(sub, parent, parent_ctx, + child, leader, child_ctx); + if (IS_ERR(child_ctr)) + return PTR_ERR(child_ctr); + } + return 0; +} + +static void sync_child_event(struct perf_event *child_event, + struct task_struct *child) +{ + struct perf_event *parent_event = child_event->parent; + u64 child_val; + + if (child_event->attr.inherit_stat) + perf_event_read_event(child_event, child); + + child_val = atomic64_read(&child_event->count); + + /* + * Add back the child's count to the parent's count: + */ + atomic64_add(child_val, &parent_event->count); + atomic64_add(child_event->total_time_enabled, + &parent_event->child_total_time_enabled); + atomic64_add(child_event->total_time_running, + &parent_event->child_total_time_running); + + /* + * Remove this event from the parent's list + */ + WARN_ON_ONCE(parent_event->ctx->parent_ctx); + mutex_lock(&parent_event->child_mutex); + list_del_init(&child_event->child_list); + mutex_unlock(&parent_event->child_mutex); + + /* + * Release the parent event, if this was the last + * reference to it. + */ + fput(parent_event->filp); +} + +static void +__perf_event_exit_task(struct perf_event *child_event, + struct perf_event_context *child_ctx, + struct task_struct *child) +{ + struct perf_event *parent_event; + + update_event_times(child_event); + perf_event_remove_from_context(child_event); + + parent_event = child_event->parent; + /* + * It can happen that parent exits first, and has events + * that are still around due to the child reference. These + * events need to be zapped - but otherwise linger. + */ + if (parent_event) { + sync_child_event(child_event, child); + free_event(child_event); + } +} + +/* + * When a child task exits, feed back event values to parent events. + */ +void perf_event_exit_task(struct task_struct *child) +{ + struct perf_event *child_event, *tmp; + struct perf_event_context *child_ctx; + unsigned long flags; + + if (likely(!child->perf_event_ctxp)) { + perf_event_task(child, NULL, 0); + return; + } + + local_irq_save(flags); + /* + * We can't reschedule here because interrupts are disabled, + * and either child is current or it is a task that can't be + * scheduled, so we are now safe from rescheduling changing + * our context. + */ + child_ctx = child->perf_event_ctxp; + __perf_event_task_sched_out(child_ctx); + + /* + * Take the context lock here so that if find_get_context is + * reading child->perf_event_ctxp, we wait until it has + * incremented the context's refcount before we do put_ctx below. + */ + spin_lock(&child_ctx->lock); + child->perf_event_ctxp = NULL; + /* + * If this context is a clone; unclone it so it can't get + * swapped to another process while we're removing all + * the events from it. + */ + unclone_ctx(child_ctx); + spin_unlock_irqrestore(&child_ctx->lock, flags); + + /* + * Report the task dead after unscheduling the events so that we + * won't get any samples after PERF_RECORD_EXIT. We can however still + * get a few PERF_RECORD_READ events. + */ + perf_event_task(child, child_ctx, 0); + + /* + * We can recurse on the same lock type through: + * + * __perf_event_exit_task() + * sync_child_event() + * fput(parent_event->filp) + * perf_release() + * mutex_lock(&ctx->mutex) + * + * But since its the parent context it won't be the same instance. + */ + mutex_lock_nested(&child_ctx->mutex, SINGLE_DEPTH_NESTING); + +again: + list_for_each_entry_safe(child_event, tmp, &child_ctx->group_list, + group_entry) + __perf_event_exit_task(child_event, child_ctx, child); + + /* + * If the last event was a group event, it will have appended all + * its siblings to the list, but we obtained 'tmp' before that which + * will still point to the list head terminating the iteration. + */ + if (!list_empty(&child_ctx->group_list)) + goto again; + + mutex_unlock(&child_ctx->mutex); + + put_ctx(child_ctx); +} + +/* + * free an unexposed, unused context as created by inheritance by + * init_task below, used by fork() in case of fail. + */ +void perf_event_free_task(struct task_struct *task) +{ + struct perf_event_context *ctx = task->perf_event_ctxp; + struct perf_event *event, *tmp; + + if (!ctx) + return; + + mutex_lock(&ctx->mutex); +again: + list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) { + struct perf_event *parent = event->parent; + + if (WARN_ON_ONCE(!parent)) + continue; + + mutex_lock(&parent->child_mutex); + list_del_init(&event->child_list); + mutex_unlock(&parent->child_mutex); + + fput(parent->filp); + + list_del_event(event, ctx); + free_event(event); + } + + if (!list_empty(&ctx->group_list)) + goto again; + + mutex_unlock(&ctx->mutex); + + put_ctx(ctx); +} + +/* + * Initialize the perf_event context in task_struct + */ +int perf_event_init_task(struct task_struct *child) +{ + struct perf_event_context *child_ctx, *parent_ctx; + struct perf_event_context *cloned_ctx; + struct perf_event *event; + struct task_struct *parent = current; + int inherited_all = 1; + int ret = 0; + + child->perf_event_ctxp = NULL; + + mutex_init(&child->perf_event_mutex); + INIT_LIST_HEAD(&child->perf_event_list); + + if (likely(!parent->perf_event_ctxp)) + return 0; + + /* + * This is executed from the parent task context, so inherit + * events that have been marked for cloning. + * First allocate and initialize a context for the child. + */ + + child_ctx = kmalloc(sizeof(struct perf_event_context), GFP_KERNEL); + if (!child_ctx) + return -ENOMEM; + + __perf_event_init_context(child_ctx, child); + child->perf_event_ctxp = child_ctx; + get_task_struct(child); + + /* + * If the parent's context is a clone, pin it so it won't get + * swapped under us. + */ + parent_ctx = perf_pin_task_context(parent); + + /* + * No need to check if parent_ctx != NULL here; since we saw + * it non-NULL earlier, the only reason for it to become NULL + * is if we exit, and since we're currently in the middle of + * a fork we can't be exiting at the same time. + */ + + /* + * Lock the parent list. No need to lock the child - not PID + * hashed yet and not running, so nobody can access it. + */ + mutex_lock(&parent_ctx->mutex); + + /* + * We dont have to disable NMIs - we are only looking at + * the list, not manipulating it: + */ + list_for_each_entry_rcu(event, &parent_ctx->event_list, event_entry) { + if (event != event->group_leader) + continue; + + if (!event->attr.inherit) { + inherited_all = 0; + continue; + } + + ret = inherit_group(event, parent, parent_ctx, + child, child_ctx); + if (ret) { + inherited_all = 0; + break; + } + } + + if (inherited_all) { + /* + * Mark the child context as a clone of the parent + * context, or of whatever the parent is a clone of. + * Note that if the parent is a clone, it could get + * uncloned at any point, but that doesn't matter + * because the list of events and the generation + * count can't have changed since we took the mutex. + */ + cloned_ctx = rcu_dereference(parent_ctx->parent_ctx); + if (cloned_ctx) { + child_ctx->parent_ctx = cloned_ctx; + child_ctx->parent_gen = parent_ctx->parent_gen; + } else { + child_ctx->parent_ctx = parent_ctx; + child_ctx->parent_gen = parent_ctx->generation; + } + get_ctx(child_ctx->parent_ctx); + } + + mutex_unlock(&parent_ctx->mutex); + + perf_unpin_context(parent_ctx); + + return ret; +} + +static void __cpuinit perf_event_init_cpu(int cpu) +{ + struct perf_cpu_context *cpuctx; + + cpuctx = &per_cpu(perf_cpu_context, cpu); + __perf_event_init_context(&cpuctx->ctx, NULL); + + spin_lock(&perf_resource_lock); + cpuctx->max_pertask = perf_max_events - perf_reserved_percpu; + spin_unlock(&perf_resource_lock); + + hw_perf_event_setup(cpu); +} + +#ifdef CONFIG_HOTPLUG_CPU +static void __perf_event_exit_cpu(void *info) +{ + struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); + struct perf_event_context *ctx = &cpuctx->ctx; + struct perf_event *event, *tmp; + + list_for_each_entry_safe(event, tmp, &ctx->group_list, group_entry) + __perf_event_remove_from_context(event); +} +static void perf_event_exit_cpu(int cpu) +{ + struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu); + struct perf_event_context *ctx = &cpuctx->ctx; + + mutex_lock(&ctx->mutex); + smp_call_function_single(cpu, __perf_event_exit_cpu, NULL, 1); + mutex_unlock(&ctx->mutex); +} +#else +static inline void perf_event_exit_cpu(int cpu) { } +#endif + +static int __cpuinit +perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) +{ + unsigned int cpu = (long)hcpu; + + switch (action) { + + case CPU_UP_PREPARE: + case CPU_UP_PREPARE_FROZEN: + perf_event_init_cpu(cpu); + break; + + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + hw_perf_event_setup_online(cpu); + break; + + case CPU_DOWN_PREPARE: + case CPU_DOWN_PREPARE_FROZEN: + perf_event_exit_cpu(cpu); + break; + + default: + break; + } + + return NOTIFY_OK; +} + +/* + * This has to have a higher priority than migration_notifier in sched.c. + */ +static struct notifier_block __cpuinitdata perf_cpu_nb = { + .notifier_call = perf_cpu_notify, + .priority = 20, +}; + +void __init perf_event_init(void) +{ + perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE, + (void *)(long)smp_processor_id()); + perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE, + (void *)(long)smp_processor_id()); + register_cpu_notifier(&perf_cpu_nb); +} + +static ssize_t perf_show_reserve_percpu(struct sysdev_class *class, char *buf) +{ + return sprintf(buf, "%d\n", perf_reserved_percpu); +} + +static ssize_t +perf_set_reserve_percpu(struct sysdev_class *class, + const char *buf, + size_t count) +{ + struct perf_cpu_context *cpuctx; + unsigned long val; + int err, cpu, mpt; + + err = strict_strtoul(buf, 10, &val); + if (err) + return err; + if (val > perf_max_events) + return -EINVAL; + + spin_lock(&perf_resource_lock); + perf_reserved_percpu = val; + for_each_online_cpu(cpu) { + cpuctx = &per_cpu(perf_cpu_context, cpu); + spin_lock_irq(&cpuctx->ctx.lock); + mpt = min(perf_max_events - cpuctx->ctx.nr_events, + perf_max_events - perf_reserved_percpu); + cpuctx->max_pertask = mpt; + spin_unlock_irq(&cpuctx->ctx.lock); + } + spin_unlock(&perf_resource_lock); + + return count; +} + +static ssize_t perf_show_overcommit(struct sysdev_class *class, char *buf) +{ + return sprintf(buf, "%d\n", perf_overcommit); +} + +static ssize_t +perf_set_overcommit(struct sysdev_class *class, const char *buf, size_t count) +{ + unsigned long val; + int err; + + err = strict_strtoul(buf, 10, &val); + if (err) + return err; + if (val > 1) + return -EINVAL; + + spin_lock(&perf_resource_lock); + perf_overcommit = val; + spin_unlock(&perf_resource_lock); + + return count; +} + +static SYSDEV_CLASS_ATTR( + reserve_percpu, + 0644, + perf_show_reserve_percpu, + perf_set_reserve_percpu + ); + +static SYSDEV_CLASS_ATTR( + overcommit, + 0644, + perf_show_overcommit, + perf_set_overcommit + ); + +static struct attribute *perfclass_attrs[] = { + &attr_reserve_percpu.attr, + &attr_overcommit.attr, + NULL +}; + +static struct attribute_group perfclass_attr_group = { + .attrs = perfclass_attrs, + .name = "perf_events", +}; + +static int __init perf_event_sysfs_init(void) +{ + return sysfs_create_group(&cpu_sysdev_class.kset.kobj, + &perfclass_attr_group); +} +device_initcall(perf_event_sysfs_init); diff --git a/kernel/sched.c b/kernel/sched.c index faf4d463bbff..291c8d213d13 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -39,7 +39,7 @@ #include #include #include -#include +#include #include #include #include @@ -2059,7 +2059,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) if (task_hot(p, old_rq->clock, NULL)) schedstat_inc(p, se.nr_forced2_migrations); #endif - perf_swcounter_event(PERF_COUNT_SW_CPU_MIGRATIONS, + perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); } p->se.vruntime -= old_cfsrq->min_vruntime - @@ -2724,7 +2724,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) */ prev_state = prev->state; finish_arch_switch(prev); - perf_counter_task_sched_in(current, cpu_of(rq)); + perf_event_task_sched_in(current, cpu_of(rq)); finish_lock_switch(rq, prev); fire_sched_in_preempt_notifiers(current); @@ -5199,7 +5199,7 @@ void scheduler_tick(void) curr->sched_class->task_tick(rq, curr, 0); spin_unlock(&rq->lock); - perf_counter_task_tick(curr, cpu); + perf_event_task_tick(curr, cpu); #ifdef CONFIG_SMP rq->idle_at_tick = idle_cpu(cpu); @@ -5415,7 +5415,7 @@ need_resched_nonpreemptible: if (likely(prev != next)) { sched_info_switch(prev, next); - perf_counter_task_sched_out(prev, next, cpu); + perf_event_task_sched_out(prev, next, cpu); rq->nr_switches++; rq->curr = next; @@ -7692,7 +7692,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) /* * Register at high priority so that task migration (migrate_all_tasks) * happens before everything else. This has to be lower priority than - * the notifier in the perf_counter subsystem, though. + * the notifier in the perf_event subsystem, though. */ static struct notifier_block __cpuinitdata migration_notifier = { .notifier_call = migration_call, @@ -9549,7 +9549,7 @@ void __init sched_init(void) alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); #endif /* SMP */ - perf_counter_init(); + perf_event_init(); scheduler_running = 1; } diff --git a/kernel/sys.c b/kernel/sys.c index b3f1097c76fa..ea5c3bcac881 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -14,7 +14,7 @@ #include #include #include -#include +#include #include #include #include @@ -1511,11 +1511,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, case PR_SET_TSC: error = SET_TSC_CTL(arg2); break; - case PR_TASK_PERF_COUNTERS_DISABLE: - error = perf_counter_task_disable(); + case PR_TASK_PERF_EVENTS_DISABLE: + error = perf_event_task_disable(); break; - case PR_TASK_PERF_COUNTERS_ENABLE: - error = perf_counter_task_enable(); + case PR_TASK_PERF_EVENTS_ENABLE: + error = perf_event_task_enable(); break; case PR_GET_TIMERSLACK: error = current->timer_slack_ns; diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 68320f6b07b5..515bc230ac2a 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -177,4 +177,4 @@ cond_syscall(sys_eventfd); cond_syscall(sys_eventfd2); /* performance counters: */ -cond_syscall(sys_perf_counter_open); +cond_syscall(sys_perf_event_open); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 1a631ba684a4..6ba49c7cb128 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -50,7 +50,7 @@ #include #include #include -#include +#include #include #include @@ -964,28 +964,28 @@ static struct ctl_table kern_table[] = { .child = slow_work_sysctls, }, #endif -#ifdef CONFIG_PERF_COUNTERS +#ifdef CONFIG_PERF_EVENTS { .ctl_name = CTL_UNNUMBERED, - .procname = "perf_counter_paranoid", - .data = &sysctl_perf_counter_paranoid, - .maxlen = sizeof(sysctl_perf_counter_paranoid), + .procname = "perf_event_paranoid", + .data = &sysctl_perf_event_paranoid, + .maxlen = sizeof(sysctl_perf_event_paranoid), .mode = 0644, .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, - .procname = "perf_counter_mlock_kb", - .data = &sysctl_perf_counter_mlock, - .maxlen = sizeof(sysctl_perf_counter_mlock), + .procname = "perf_event_mlock_kb", + .data = &sysctl_perf_event_mlock, + .maxlen = sizeof(sysctl_perf_event_mlock), .mode = 0644, .proc_handler = &proc_dointvec, }, { .ctl_name = CTL_UNNUMBERED, - .procname = "perf_counter_max_sample_rate", - .data = &sysctl_perf_counter_sample_rate, - .maxlen = sizeof(sysctl_perf_counter_sample_rate), + .procname = "perf_event_max_sample_rate", + .data = &sysctl_perf_event_sample_rate, + .maxlen = sizeof(sysctl_perf_event_sample_rate), .mode = 0644, .proc_handler = &proc_dointvec, }, diff --git a/kernel/timer.c b/kernel/timer.c index bbb51074680e..811e5c391456 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -37,7 +37,7 @@ #include #include #include -#include +#include #include #include @@ -1187,7 +1187,7 @@ static void run_timer_softirq(struct softirq_action *h) { struct tvec_base *base = __get_cpu_var(tvec_bases); - perf_counter_do_pending(); + perf_event_do_pending(); hrtimer_run_pending(); diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 8712ce3c6a0e..233f3483ac83 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -2,7 +2,7 @@ #include #include #include -#include +#include #include #include "trace_output.h" @@ -414,7 +414,7 @@ static void prof_syscall_enter(struct pt_regs *regs, long id) rec->nr = syscall_nr; syscall_get_arguments(current, regs, 0, sys_data->nb_args, (unsigned long *)&rec->args); - perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size); + perf_tp_event(sys_data->enter_id, 0, 1, rec, size); } while(0); } @@ -476,7 +476,7 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) rec.nr = syscall_nr; rec.ret = syscall_get_return_value(current, regs); - perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec)); + perf_tp_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec)); } int reg_prof_syscall_exit(char *name) -- cgit v1.2.2 From 1f74b1f7e5be08e4b884c8bd9e776f0e440b14f1 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Mon, 31 Aug 2009 15:13:06 +0200 Subject: microblaze: Enable GCOV_PROFILE_ALL Signed-off-by: Michal Simek --- kernel/gcov/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig index 654efd09f6a9..70a298d6da71 100644 --- a/kernel/gcov/Kconfig +++ b/kernel/gcov/Kconfig @@ -34,7 +34,7 @@ config GCOV_KERNEL config GCOV_PROFILE_ALL bool "Profile entire Kernel" depends on GCOV_KERNEL - depends on S390 || X86 || (PPC && EXPERIMENTAL) + depends on S390 || X86 || (PPC && EXPERIMENTAL) || MICROBLAZE default n ---help--- This options activates profiling for the entire kernel. -- cgit v1.2.2 From 57c0c15b5244320065374ad2c54f4fbec77a6428 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 21 Sep 2009 12:20:38 +0200 Subject: perf: Tidy up after the big rename - provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven Acked-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Frederic Weisbecker LKML-Reference: Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 6e8b99a04e1e..76ac4db405e9 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1,12 +1,12 @@ /* - * Performance event core code + * Performance events core code: * * Copyright (C) 2008 Thomas Gleixner * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra * Copyright © 2009 Paul Mackerras, IBM Corp. * - * For licensing details see kernel-base/COPYING + * For licensing details see kernel-base/COPYING */ #include -- cgit v1.2.2 From fe002a419755f991e1219249c8ffe7dc0b798232 Mon Sep 17 00:00:00 2001 From: "Robert P. J. Day" Date: Sun, 28 Jun 2009 21:10:07 -0400 Subject: trivial: Correct print_tainted routine name in comment Signed-off-by: Robert P. J. Day Signed-off-by: Jiri Kosina --- kernel/panic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/panic.c b/kernel/panic.c index 512ab73b0ca3..bcdef26e3332 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -177,7 +177,7 @@ static const struct tnt tnts[] = { * 'W' - Taint on warning. * 'C' - modules from drivers/staging are loaded. * - * The string is overwritten by the next call to print_taint(). + * The string is overwritten by the next call to print_tainted(). */ const char *print_tainted(void) { -- cgit v1.2.2 From fd589a8f0a13f53a2dd580b1fe170633cf6b095f Mon Sep 17 00:00:00 2001 From: Anand Gadiyar Date: Thu, 16 Jul 2009 17:13:03 +0200 Subject: trivial: fix typo "to to" in multiple files Signed-off-by: Anand Gadiyar Signed-off-by: Jiri Kosina --- kernel/tracepoint.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 9489a0a9b1be..cc89be5bc0f8 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -48,7 +48,7 @@ static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE]; /* * Note about RCU : - * It is used to to delay the free of multiple probes array until a quiescent + * It is used to delay the free of multiple probes array until a quiescent * state is reached. * Tracepoint entries modifications are protected by the tracepoints_mutex. */ -- cgit v1.2.2 From 2944fcbe03d65a704f07e43efe14adb0d226fd09 Mon Sep 17 00:00:00 2001 From: Uwe Kleine-Koenig Date: Wed, 5 Aug 2009 22:06:42 +0200 Subject: trivial: Fix duplicated word "options" in comment this was introduced in 5e0a093 (tracing: fix config options to not show when automatically selected) Signed-off-by: Uwe Kleine-Koenig Cc: Steven Rostedt Cc: trivial@kernel.org Signed-off-by: Jiri Kosina --- kernel/trace/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index e71634604400..b416512ad17f 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -83,7 +83,7 @@ config RING_BUFFER_ALLOW_SWAP # This allows those options to appear when no other tracer is selected. But the # options do not appear when something else selects it. We need the two options # GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the -# hidding of the automatic options options. +# hidding of the automatic options. config TRACING bool -- cgit v1.2.2 From a419aef8b858a2bdb98df60336063d28df4b272f Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Tue, 18 Aug 2009 11:18:35 -0700 Subject: trivial: remove unnecessary semicolons Signed-off-by: Joe Perches Signed-off-by: Jiri Kosina --- kernel/trace/trace_hw_branches.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c index ca7d7c4d0c2a..23b63859130e 100644 --- a/kernel/trace/trace_hw_branches.c +++ b/kernel/trace/trace_hw_branches.c @@ -155,7 +155,7 @@ static enum print_line_t bts_trace_print_line(struct trace_iterator *iter) seq_print_ip_sym(seq, it->from, symflags) && trace_seq_printf(seq, "\n")) return TRACE_TYPE_HANDLED; - return TRACE_TYPE_PARTIAL_LINE;; + return TRACE_TYPE_PARTIAL_LINE; } return TRACE_TYPE_UNHANDLED; } -- cgit v1.2.2 From b87221de6a4934eda856475a0065688d12973a04 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 21 Sep 2009 17:01:09 -0700 Subject: const: mark remaining super_operations const Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c7ece8f027f2..39dde299a920 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -961,7 +961,7 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) return ret; } -static struct super_operations cgroup_ops = { +static const struct super_operations cgroup_ops = { .statfs = simple_statfs, .drop_inode = generic_delete_inode, .show_options = cgroup_show_options, -- cgit v1.2.2 From 6e1d5dcc2bbbe71dbf010c747e15739bef6b7218 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 21 Sep 2009 17:01:11 -0700 Subject: const: mark remaining inode_operations as const Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 39dde299a920..213b7f92fcdd 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -596,7 +596,7 @@ void cgroup_unlock(void) static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode); static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry); static int cgroup_populate_dir(struct cgroup *cgrp); -static struct inode_operations cgroup_dir_inode_operations; +static const struct inode_operations cgroup_dir_inode_operations; static struct file_operations proc_cgroupstats_operations; static struct backing_dev_info cgroup_backing_dev_info = { @@ -1711,7 +1711,7 @@ static struct file_operations cgroup_file_operations = { .release = cgroup_file_release, }; -static struct inode_operations cgroup_dir_inode_operations = { +static const struct inode_operations cgroup_dir_inode_operations = { .lookup = simple_lookup, .mkdir = cgroup_mkdir, .rmdir = cgroup_rmdir, -- cgit v1.2.2 From c6a7f5728a1db45d30df55a01adc130b4ab0327c Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Mon, 21 Sep 2009 17:01:32 -0700 Subject: mm: oom analysis: Show kernel stack usage in /proc/meminfo and OOM log output The amount of memory allocated to kernel stacks can become significant and cause OOM conditions. However, we do not display the amount of memory consumed by stacks. Add code to display the amount of memory used for stacks in /proc/meminfo. Signed-off-by: KOSAKI Motohiro Reviewed-by: Christoph Lameter Reviewed-by: Minchan Kim Reviewed-by: Rik van Riel Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 2cebfb23b0b8..d4638c8cc19e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -136,9 +136,17 @@ struct kmem_cache *vm_area_cachep; /* SLAB cache for mm_struct structures (tsk->mm) */ static struct kmem_cache *mm_cachep; +static void account_kernel_stack(struct thread_info *ti, int account) +{ + struct zone *zone = page_zone(virt_to_page(ti)); + + mod_zone_page_state(zone, NR_KERNEL_STACK, account); +} + void free_task(struct task_struct *tsk) { prop_local_destroy_single(&tsk->dirties); + account_kernel_stack(tsk->stack, -1); free_thread_info(tsk->stack); rt_mutex_debug_task_free(tsk); ftrace_graph_exit_task(tsk); @@ -253,6 +261,9 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) tsk->btrace_seq = 0; #endif tsk->splice_pipe = NULL; + + account_kernel_stack(ti, 1); + return tsk; out: -- cgit v1.2.2 From f8af4da3b4c14e7267c4ffb952079af3912c51c5 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 21 Sep 2009 17:01:57 -0700 Subject: ksm: the mm interface to ksm This patch presents the mm interface to a dummy version of ksm.c, for better scrutiny of that interface: the real ksm.c follows later. When CONFIG_KSM is not set, madvise(2) reject MADV_MERGEABLE and MADV_UNMERGEABLE with EINVAL, since that seems more helpful than pretending that they can be serviced. But when CONFIG_KSM=y, accept them even if KSM is not currently running, and even on areas which KSM will not touch (e.g. hugetlb or shared file or special driver mappings). Like other madvices, report ENOMEM despite success if any area in the range is unmapped, and use EAGAIN to report out of memory. Define vma flag VM_MERGEABLE to identify an area on which KSM may try merging pages: leave it to ksm_madvise() to decide whether to set it. Define mm flag MMF_VM_MERGEABLE to identify an mm which might contain VM_MERGEABLE areas, to minimize callouts when forking or exiting. Based upon earlier patches by Chris Wright and Izik Eidus. Signed-off-by: Hugh Dickins Signed-off-by: Chris Wright Signed-off-by: Izik Eidus Cc: Michael Kerrisk Cc: Andrea Arcangeli Cc: Rik van Riel Cc: Wu Fengguang Cc: Balbir Singh Cc: Hugh Dickins Cc: KAMEZAWA Hiroyuki Cc: Lee Schermerhorn Cc: Avi Kivity Cc: Nick Piggin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index d4638c8cc19e..73a442b7be6d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include #include @@ -299,6 +300,9 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) rb_link = &mm->mm_rb.rb_node; rb_parent = NULL; pprev = &mm->mmap; + retval = ksm_fork(mm, oldmm); + if (retval) + goto out; for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) { struct file *file; @@ -435,7 +439,8 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) atomic_set(&mm->mm_count, 1); init_rwsem(&mm->mmap_sem); INIT_LIST_HEAD(&mm->mmlist); - mm->flags = (current->mm) ? current->mm->flags : default_dump_filter; + mm->flags = (current->mm) ? + (current->mm->flags & MMF_INIT_MASK) : default_dump_filter; mm->core_state = NULL; mm->nr_ptes = 0; set_mm_counter(mm, file_rss, 0); @@ -496,6 +501,7 @@ void mmput(struct mm_struct *mm) if (atomic_dec_and_test(&mm->mm_users)) { exit_aio(mm); + ksm_exit(mm); exit_mmap(mm); set_mm_exe_file(mm, NULL); if (!list_empty(&mm->mmlist)) { -- cgit v1.2.2 From 9ba6929480088a85c1ff60a4b1f1c9fc80dbd2b7 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 21 Sep 2009 17:02:20 -0700 Subject: ksm: fix oom deadlock There's a now-obvious deadlock in KSM's out-of-memory handling: imagine ksmd or KSM_RUN_UNMERGE handling, holding ksm_thread_mutex, trying to allocate a page to break KSM in an mm which becomes the OOM victim (quite likely in the unmerge case): it's killed and goes to exit, and hangs there waiting to acquire ksm_thread_mutex. Clearly we must not require ksm_thread_mutex in __ksm_exit, simple though that made everything else: perhaps use mmap_sem somehow? And part of the answer lies in the comments on unmerge_ksm_pages: __ksm_exit should also leave all the rmap_item removal to ksmd. But there's a fundamental problem, that KSM relies upon mmap_sem to guarantee the consistency of the mm it's dealing with, yet exit_mmap tears down an mm without taking mmap_sem. And bumping mm_users won't help at all, that just ensures that the pages the OOM killer assumes are on their way to being freed will not be freed. The best answer seems to be, to move the ksm_exit callout from just before exit_mmap, to the middle of exit_mmap: after the mm's pages have been freed (if the mmu_gather is flushed), but before its page tables and vma structures have been freed; and down_write,up_write mmap_sem there to serialize with KSM's own reliance on mmap_sem. But KSM then needs to be careful, whenever it downs mmap_sem, to check that the mm is not already exiting: there's a danger of using find_vma on a layout that's being torn apart, or writing into page tables which have been freed for reuse; and even do_anonymous_page and __do_fault need to check they're not being called by break_ksm to reinstate a pte after zap_pte_range has zapped that page table. Though it might be clearer to add an exiting flag, set while holding mmap_sem in __ksm_exit, that wouldn't cover the issue of reinstating a zapped pte. All we need is to check whether mm_users is 0 - but must remember that ksmd may detect that before __ksm_exit is reached. So, ksm_test_exit(mm) added to comment such checks on mm->mm_users. __ksm_exit now has to leave clearing up the rmap_items to ksmd, that needs ksm_thread_mutex; but shift the exiting mm just after the ksm_scan cursor so that it will soon be dealt with. __ksm_enter raise mm_count to hold the mm_struct, ksmd's exit processing (exactly like its processing when it finds all VM_MERGEABLEs unmapped) mmdrop it, similar procedure for KSM_RUN_UNMERGE (which has stopped ksmd). But also give __ksm_exit a fast path: when there's no complication (no rmap_items attached to mm and it's not at the ksm_scan cursor), it can safely do all the exiting work itself. This is not just an optimization: when ksmd is not running, the raised mm_count would otherwise leak mm_structs. Signed-off-by: Hugh Dickins Acked-by: Izik Eidus Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 73a442b7be6d..42f20f565b16 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -501,7 +501,6 @@ void mmput(struct mm_struct *mm) if (atomic_dec_and_test(&mm->mm_users)) { exit_aio(mm); - ksm_exit(mm); exit_mmap(mm); set_mm_exe_file(mm, NULL); if (!list_empty(&mm->mmlist)) { -- cgit v1.2.2 From 1c2fb7a4c2ca7a958b02bc1e615d0254990bba8d Mon Sep 17 00:00:00 2001 From: Andrea Arcangeli Date: Mon, 21 Sep 2009 17:02:22 -0700 Subject: ksm: fix deadlock with munlock in exit_mmap Rawhide users have reported hang at startup when cryptsetup is run: the same problem can be simply reproduced by running a program int main() { mlockall(MCL_CURRENT | MCL_FUTURE); return 0; } The problem is that exit_mmap() applies munlock_vma_pages_all() to clean up VM_LOCKED areas, and its current implementation (stupidly) tries to fault in absent pages, for example where PROT_NONE prevented them being faulted in when mlocking. Whereas the "ksm: fix oom deadlock" patch, knowing there's a race by which KSM might try to fault in pages after exit_mmap() had finally zapped the range, backs out of such faults doing nothing when its ksm_test_exit() notices mm_users 0. So revert that part of "ksm: fix oom deadlock" which moved the ksm_exit() call from before exit_mmap() to the middle of exit_mmap(); and remove those ksm_test_exit() checks from the page fault paths, so allowing the munlocking to proceed without interference. ksm_exit, if there are rmap_items still chained on this mm slot, takes mmap_sem write side: so preventing KSM from working on an mm while exit_mmap runs. And KSM will bail out as soon as it notices that mm_users is already zero, thanks to its internal ksm_test_exit checks. So that when a task is killed by OOM killer or the user, KSM will not indefinitely prevent it from running exit_mmap to release its memory. This does break a part of what "ksm: fix oom deadlock" was trying to achieve. When unmerging KSM (echo 2 >/sys/kernel/mm/ksm), and even when ksmd itself has to cancel a KSM page, it is possible that the first OOM-kill victim would be the KSM process being faulted: then its memory won't be freed until a second victim has been selected (freeing memory for the unmerging fault to complete). But the OOM killer is already liable to kill a second victim once the intended victim's p->mm goes to NULL: so there's not much point in rejecting this KSM patch before fixing that OOM behaviour. It is very much more important to allow KSM users to boot up, than to haggle over an unlikely and poorly supported OOM case. We also intend to fix munlocking to not fault pages: at which point this patch _could_ be reverted; though that would be controversial, so we hope to find a better solution. Signed-off-by: Andrea Arcangeli Acked-by: Justin M. Forbes Acked-for-now-by: Hugh Dickins Cc: Izik Eidus Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 42f20f565b16..73a442b7be6d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -501,6 +501,7 @@ void mmput(struct mm_struct *mm) if (atomic_dec_and_test(&mm->mm_users)) { exit_aio(mm); + ksm_exit(mm); exit_mmap(mm); set_mm_exe_file(mm, NULL); if (!list_empty(&mm->mmlist)) { -- cgit v1.2.2 From 3c1596efe167322dae87f8390d36f91ce2d7f936 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 21 Sep 2009 17:03:06 -0700 Subject: mm: don't use alloc_bootmem_low() where not strictly needed Since alloc_bootmem() will never return inaccessible (via virtual addressing) memory anyway, using the ..._low() variant only makes sense when the physical address range of the allocated memory must fulfill further constraints, espacially since on 64-bits (or more generally in all cases where the pools the two variants allocate from are than the full available range. Probably the use in alloc_tce_table() could also be eliminated (based on code inspection of pci-calgary_64.c), but that seems too risky given I know nothing about that hardware and have no way to test it. Signed-off-by: Jan Beulich Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/snapshot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 97955b0e44f4..36cb168e4330 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -619,7 +619,7 @@ __register_nosave_region(unsigned long start_pfn, unsigned long end_pfn, BUG_ON(!region); } else /* This allocation cannot fail */ - region = alloc_bootmem_low(sizeof(struct nosave_region)); + region = alloc_bootmem(sizeof(struct nosave_region)); region->start_pfn = start_pfn; region->end_pfn = end_pfn; list_add_tail(®ion->list, &nosave_regions); -- cgit v1.2.2 From 2c85f51d222ccdd8c401d77a36b723a89156810d Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 21 Sep 2009 17:03:07 -0700 Subject: mm: also use alloc_large_system_hash() for the PID hash table This is being done by allowing boot time allocations to specify that they may want a sub-page sized amount of memory. Overall this seems more consistent with the other hash table allocations, and allows making two supposedly mm-only variables really mm-only (nr_{kernel,all}_pages). Signed-off-by: Jan Beulich Cc: Ingo Molnar Cc: "Eric W. Biederman" Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/pid.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) (limited to 'kernel') diff --git a/kernel/pid.c b/kernel/pid.c index 31310b5d3f50..d3f722d20f9c 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -40,7 +40,7 @@ #define pid_hashfn(nr, ns) \ hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift) static struct hlist_head *pid_hash; -static int pidhash_shift; +static unsigned int pidhash_shift = 4; struct pid init_struct_pid = INIT_STRUCT_PID; int pid_max = PID_MAX_DEFAULT; @@ -499,19 +499,12 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns) void __init pidhash_init(void) { int i, pidhash_size; - unsigned long megabytes = nr_kernel_pages >> (20 - PAGE_SHIFT); - pidhash_shift = max(4, fls(megabytes * 4)); - pidhash_shift = min(12, pidhash_shift); + pid_hash = alloc_large_system_hash("PID", sizeof(*pid_hash), 0, 18, + HASH_EARLY | HASH_SMALL, + &pidhash_shift, NULL, 4096); pidhash_size = 1 << pidhash_shift; - printk("PID hash table entries: %d (order: %d, %Zd bytes)\n", - pidhash_size, pidhash_shift, - pidhash_size * sizeof(struct hlist_head)); - - pid_hash = alloc_bootmem(pidhash_size * sizeof(*(pid_hash))); - if (!pid_hash) - panic("Could not alloc pidhash!\n"); for (i = 0; i < pidhash_size; i++) INIT_HLIST_HEAD(&pid_hash[i]); } -- cgit v1.2.2 From 1a8670a29b5277cbe601f74ab63d2c5211fb3005 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Mon, 21 Sep 2009 17:03:09 -0700 Subject: oom: move oom_killer_enable()/oom_killer_disable to where they belong Signed-off-by: Alexey Dobriyan Acked-by: David Rientjes Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/process.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/power/process.c b/kernel/power/process.c index da2072d73811..cc2e55373b68 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -9,6 +9,7 @@ #undef DEBUG #include +#include #include #include #include -- cgit v1.2.2 From 28b83c5193e7ab951e402252278f2cc79dc4d298 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Mon, 21 Sep 2009 17:03:13 -0700 Subject: oom: move oom_adj value from task_struct to signal_struct Currently, OOM logic callflow is here. __out_of_memory() select_bad_process() for each task badness() calculate badness of one task oom_kill_process() search child oom_kill_task() kill target task and mm shared tasks with it example, process-A have two thread, thread-A and thread-B and it have very fat memory and each thread have following oom_adj and oom_score. thread-A: oom_adj = OOM_DISABLE, oom_score = 0 thread-B: oom_adj = 0, oom_score = very-high Then, select_bad_process() select thread-B, but oom_kill_task() refuse kill the task because thread-A have OOM_DISABLE. Thus __out_of_memory() call select_bad_process() again. but select_bad_process() select the same task. It mean kernel fall in livelock. The fact is, select_bad_process() must select killable task. otherwise OOM logic go into livelock. And root cause is, oom_adj shouldn't be per-thread value. it should be per-process value because OOM-killer kill a process, not thread. Thus This patch moves oomkilladj (now more appropriately named oom_adj) from struct task_struct to struct signal_struct. it naturally prevent select_bad_process() choose wrong task. Signed-off-by: KOSAKI Motohiro Cc: Paul Menage Cc: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: Rik van Riel Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 73a442b7be6d..1020977b57ca 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -880,6 +880,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) tty_audit_fork(sig); + sig->oom_adj = current->signal->oom_adj; + return 0; } -- cgit v1.2.2 From eb8cdec4a984fde123a91250dcc9e0bddf5eafdc Mon Sep 17 00:00:00 2001 From: Bernd Schmidt Date: Mon, 21 Sep 2009 17:03:57 -0700 Subject: nommu: add support for Memory Protection Units (MPU) Some architectures (like the Blackfin arch) implement some of the "simpler" features that one would expect out of a MMU such as memory protection. In our case, we actually get read/write/exec protection down to the page boundary so processes can't stomp on each other let alone the kernel. There is a performance decrease (which depends greatly on the workload) however as the hardware/software interaction was not optimized at design time. Signed-off-by: Bernd Schmidt Signed-off-by: Bryan Wu Signed-off-by: Mike Frysinger Acked-by: David Howells Acked-by: Greg Ungerer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/module.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index b6ee424245dd..e6bc4b28aa62 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -47,6 +47,7 @@ #include #include #include +#include #include #include #include @@ -1535,6 +1536,10 @@ static void free_module(struct module *mod) /* Finally, free the core (containing the module structure) */ module_free(mod, mod->module_core); + +#ifdef CONFIG_MPU + update_protections(current->mm); +#endif } void *__symbol_get(const char *symbol) -- cgit v1.2.2 From 69d25870f20c4b2563304f2b79c5300dd60a067e Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 21 Sep 2009 17:04:08 -0700 Subject: cpuidle: fix the menu governor to boost IO performance Fix the menu idle governor which balances power savings, energy efficiency and performance impact. The reason for a reworked governor is that there have been serious performance issues reported with the existing code on Nehalem server systems. To show this I'm sure Andrew wants to see benchmark results: (benchmark is "fio", "no cstates" is using "idle=poll") no cstates current linux new algorithm 1 disk 107 Mb/s 85 Mb/s 105 Mb/s 2 disks 215 Mb/s 123 Mb/s 209 Mb/s 12 disks 590 Mb/s 320 Mb/s 585 Mb/s In various power benchmark measurements, no degredation was found by our measurement&diagnostics team. Obviously a small percentage more power was used in the "fio" benchmark, due to the much higher performance. While it would be a novel idea to describe the new algorithm in this commit message, I cheaped out and described it in comments in the code instead. [changes since first post: spelling fixes from akpm, review feedback, folded menu-tng into menu.c] Signed-off-by: Arjan van de Ven Cc: Venkatesh Pallipadi Cc: Len Brown Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Yanmin Zhang Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sched.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 91843ba7f237..0ac9053c21d6 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2904,6 +2904,19 @@ unsigned long nr_iowait(void) return sum; } +unsigned long nr_iowait_cpu(void) +{ + struct rq *this = this_rq(); + return atomic_read(&this->nr_iowait); +} + +unsigned long this_cpu_load(void) +{ + struct rq *this = this_rq(); + return this->cpu_load[0]; +} + + /* Variables and functions for calc_load */ static atomic_long_t calc_load_tasks; static unsigned long calc_load_update; -- cgit v1.2.2 From 3a3b6ed2235f2f619889dd6096e24b6d93bf3339 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Tue, 22 Sep 2009 16:43:31 -0700 Subject: printk boot_delay: rename printk_delay_msec to loops_per_msec Rename `printk_delay_msec' to `loops_per_msec', because the patch "printk: add printk_delay to make messages readable for some scenarios" wishes to more appropriately use the `printk_delay_msec' identifier. [akpm@linux-foundation.org: add a comment] Signed-off-by: Dave Young Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/printk.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/printk.c b/kernel/printk.c index 602033acd6c7..932ea21feb18 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -206,12 +206,11 @@ __setup("log_buf_len=", log_buf_len_setup); #ifdef CONFIG_BOOT_PRINTK_DELAY static unsigned int boot_delay; /* msecs delay after each printk during bootup */ -static unsigned long long printk_delay_msec; /* per msec, based on boot_delay */ +static unsigned long long loops_per_msec; /* based on boot_delay */ static int __init boot_delay_setup(char *str) { unsigned long lpj; - unsigned long long loops_per_msec; lpj = preset_lpj ? preset_lpj : 1000000; /* some guess */ loops_per_msec = (unsigned long long)lpj / 1000 * HZ; @@ -220,10 +219,9 @@ static int __init boot_delay_setup(char *str) if (boot_delay > 10 * 1000) boot_delay = 0; - printk_delay_msec = loops_per_msec; - printk(KERN_DEBUG "boot_delay: %u, preset_lpj: %ld, lpj: %lu, " - "HZ: %d, printk_delay_msec: %llu\n", - boot_delay, preset_lpj, lpj, HZ, printk_delay_msec); + pr_debug("boot_delay: %u, preset_lpj: %ld, lpj: %lu, " + "HZ: %d, loops_per_msec: %llu\n", + boot_delay, preset_lpj, lpj, HZ, loops_per_msec); return 1; } __setup("boot_delay=", boot_delay_setup); @@ -236,7 +234,7 @@ static void boot_delay_msec(void) if (boot_delay == 0 || system_state != SYSTEM_BOOTING) return; - k = (unsigned long long)printk_delay_msec * boot_delay; + k = (unsigned long long)loops_per_msec * boot_delay; timeout = jiffies + msecs_to_jiffies(boot_delay); while (k) { -- cgit v1.2.2 From af91322ef3f29ae4114e736e2a72e28b4d619cf9 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Tue, 22 Sep 2009 16:43:33 -0700 Subject: printk: add printk_delay to make messages readable for some scenarios When syslog is not possible, at the same time there's no serial/net console available, it will be hard to read the printk messages. For example oops/panic/warning messages in shutdown phase. Add a printk delay feature, we can make each printk message delay some milliseconds. Setting the delay by proc/sysctl interface: /proc/sys/kernel/printk_delay The value range from 0 - 10000, default value is 0 [akpm@linux-foundation.org: fix a few things] Signed-off-by: Dave Young Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/printk.c | 15 +++++++++++++++ kernel/sysctl.c | 14 ++++++++++++++ 2 files changed, 29 insertions(+) (limited to 'kernel') diff --git a/kernel/printk.c b/kernel/printk.c index 932ea21feb18..f38b07f78a4e 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -653,6 +653,20 @@ static int recursion_bug; static int new_text_line = 1; static char printk_buf[1024]; +int printk_delay_msec __read_mostly; + +static inline void printk_delay(void) +{ + if (unlikely(printk_delay_msec)) { + int m = printk_delay_msec; + + while (m--) { + mdelay(1); + touch_nmi_watchdog(); + } + } +} + asmlinkage int vprintk(const char *fmt, va_list args) { int printed_len = 0; @@ -662,6 +676,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) char *p; boot_delay_msec(); + printk_delay(); preempt_disable(); /* This stops the holder of console_sem just where we want him */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6ba49c7cb128..0dfaa47d7cb6 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -106,6 +106,9 @@ static int __maybe_unused one = 1; static int __maybe_unused two = 2; static unsigned long one_ul = 1; static int one_hundred = 100; +#ifdef CONFIG_PRINTK +static int ten_thousand = 10000; +#endif /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */ static unsigned long dirty_bytes_min = 2 * PAGE_SIZE; @@ -722,6 +725,17 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "printk_delay", + .data = &printk_delay_msec, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &ten_thousand, + }, #endif { .ctl_name = KERN_NGROUPS_MAX, -- cgit v1.2.2 From c02e3f361c75da04ca3025b4d19e947e9cc62ed3 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Tue, 22 Sep 2009 16:43:36 -0700 Subject: kmod: fix race in usermodehelper code The user mode helper code has a race in it. call_usermodehelper_exec() takes an allocated subprocess_info structure, which it passes to a workqueue, and then passes it to a kernel thread which it creates, after which it calls complete to signal to the caller of call_usermodehelper_exec() that it can free the subprocess_info struct. But since we use that structure in the created thread, we can't call complete from __call_usermodehelper(), which is where we create the kernel thread. We need to call complete() from within the kernel thread and then not use subprocess_info afterward in the case of UMH_WAIT_EXEC. Tested successfully by me. Signed-off-by: Neil Horman Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kmod.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/kmod.c b/kernel/kmod.c index 9fcb53a11f87..689d20f39305 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -143,6 +143,7 @@ struct subprocess_info { static int ____call_usermodehelper(void *data) { struct subprocess_info *sub_info = data; + enum umh_wait wait = sub_info->wait; int retval; BUG_ON(atomic_read(&sub_info->cred->usage) != 1); @@ -184,10 +185,14 @@ static int ____call_usermodehelper(void *data) */ set_user_nice(current, 0); + if (wait == UMH_WAIT_EXEC) + complete(sub_info->complete); + retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp); /* Exec failed? */ - sub_info->retval = retval; + if (wait != UMH_WAIT_EXEC) + sub_info->retval = retval; do_exit(0); } @@ -266,16 +271,14 @@ static void __call_usermodehelper(struct work_struct *work) switch (wait) { case UMH_NO_WAIT: + case UMH_WAIT_EXEC: break; case UMH_WAIT_PROC: if (pid > 0) break; sub_info->retval = pid; - /* FALLTHROUGH */ - - case UMH_WAIT_EXEC: - complete(sub_info->complete); + break; } } -- cgit v1.2.2 From 54fdade1c3332391948ec43530c02c4794a38172 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Tue, 22 Sep 2009 16:43:39 -0700 Subject: generic-ipi: make struct call_function_data lockless This patch can remove spinlock from struct call_function_data, the reasons are below: 1: add a new interface for cpumask named cpumask_test_and_clear_cpu(), it can atomically test and clear specific cpu, we can use it instead of cpumask_test_cpu() and cpumask_clear_cpu() and no need data->lock to protect those in generic_smp_call_function_interrupt(). 2: in smp_call_function_many(), after csd_lock() return, the current's cfd_data is deleted from call_function list, so it not have race between other cpus, then cfs_data is only used in smp_call_function_many() that must disable preemption and not from a hardware interrupthandler or from a bottom half handler to call, only the correspond cpu can use it, so it not have race in current cpu, no need cfs_data->lock to protect it. 3: after 1 and 2, cfs_data->lock is only use to protect cfs_data->refs in generic_smp_call_function_interrupt(), so we can define cfs_data->refs to atomic_t, and no need cfs_data->lock any more. Signed-off-by: Xiao Guangrong Cc: Ingo Molnar Cc: Jens Axboe Cc: Nick Piggin Cc: Peter Zijlstra Acked-by: Rusty Russell [akpm@linux-foundation.org: use atomic_dec_return()] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/smp.c | 29 ++++++++--------------------- 1 file changed, 8 insertions(+), 21 deletions(-) (limited to 'kernel') diff --git a/kernel/smp.c b/kernel/smp.c index 8e218500ab14..fd47a256a24e 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -29,8 +29,7 @@ enum { struct call_function_data { struct call_single_data csd; - spinlock_t lock; - unsigned int refs; + atomic_t refs; cpumask_var_t cpumask; }; @@ -39,9 +38,7 @@ struct call_single_queue { spinlock_t lock; }; -static DEFINE_PER_CPU(struct call_function_data, cfd_data) = { - .lock = __SPIN_LOCK_UNLOCKED(cfd_data.lock), -}; +static DEFINE_PER_CPU(struct call_function_data, cfd_data); static int hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu) @@ -196,25 +193,18 @@ void generic_smp_call_function_interrupt(void) list_for_each_entry_rcu(data, &call_function.queue, csd.list) { int refs; - spin_lock(&data->lock); - if (!cpumask_test_cpu(cpu, data->cpumask)) { - spin_unlock(&data->lock); + if (!cpumask_test_and_clear_cpu(cpu, data->cpumask)) continue; - } - cpumask_clear_cpu(cpu, data->cpumask); - spin_unlock(&data->lock); data->csd.func(data->csd.info); - spin_lock(&data->lock); - WARN_ON(data->refs == 0); - refs = --data->refs; + refs = atomic_dec_return(&data->refs); + WARN_ON(refs < 0); if (!refs) { spin_lock(&call_function.lock); list_del_rcu(&data->csd.list); spin_unlock(&call_function.lock); } - spin_unlock(&data->lock); if (refs) continue; @@ -419,23 +409,20 @@ void smp_call_function_many(const struct cpumask *mask, data = &__get_cpu_var(cfd_data); csd_lock(&data->csd); - spin_lock_irqsave(&data->lock, flags); data->csd.func = func; data->csd.info = info; cpumask_and(data->cpumask, mask, cpu_online_mask); cpumask_clear_cpu(this_cpu, data->cpumask); - data->refs = cpumask_weight(data->cpumask); + atomic_set(&data->refs, cpumask_weight(data->cpumask)); - spin_lock(&call_function.lock); + spin_lock_irqsave(&call_function.lock, flags); /* * Place entry at the _HEAD_ of the list, so that any cpu still * observing the entry in generic_smp_call_function_interrupt() * will not miss any other list entries: */ list_add_rcu(&data->csd.list, &call_function.queue); - spin_unlock(&call_function.lock); - - spin_unlock_irqrestore(&data->lock, flags); + spin_unlock_irqrestore(&call_function.lock, flags); /* * Make the list addition visible before sending the ipi. -- cgit v1.2.2 From 88e9d34c727883d7d6f02cf1475b3ec98b8480c7 Mon Sep 17 00:00:00 2001 From: James Morris Date: Tue, 22 Sep 2009 16:43:43 -0700 Subject: seq_file: constify seq_operations Make all seq_operations structs const, to help mitigate against revectoring user-triggerable function pointers. This is derived from the grsecurity patch, although generated from scratch because it's simpler than extracting the changes from there. Signed-off-by: James Morris Acked-by: Serge Hallyn Acked-by: Casey Schaufler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 2 +- kernel/kprobes.c | 2 +- kernel/lockdep_proc.c | 2 +- kernel/trace/ftrace.c | 4 ++-- kernel/trace/trace.c | 4 ++-- 5 files changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 213b7f92fcdd..cd83d9933b6b 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2314,7 +2314,7 @@ static int cgroup_tasks_show(struct seq_file *s, void *v) return seq_printf(s, "%d\n", *(int *)v); } -static struct seq_operations cgroup_tasks_seq_operations = { +static const struct seq_operations cgroup_tasks_seq_operations = { .start = cgroup_tasks_start, .stop = cgroup_tasks_stop, .next = cgroup_tasks_next, diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ef177d653b2c..cfadc1291d0b 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1321,7 +1321,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v) return 0; } -static struct seq_operations kprobes_seq_ops = { +static const struct seq_operations kprobes_seq_ops = { .start = kprobe_seq_start, .next = kprobe_seq_next, .stop = kprobe_seq_stop, diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index d4b3dbc79fdb..d4aba4f3584c 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c @@ -594,7 +594,7 @@ static int ls_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations lockstat_ops = { +static const struct seq_operations lockstat_ops = { .start = ls_start, .next = ls_next, .stop = ls_stop, diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c71e91bf7372..23df7771c937 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1520,7 +1520,7 @@ static int t_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations show_ftrace_seq_ops = { +static const struct seq_operations show_ftrace_seq_ops = { .start = t_start, .next = t_next, .stop = t_stop, @@ -2459,7 +2459,7 @@ static int g_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations ftrace_graph_seq_ops = { +static const struct seq_operations ftrace_graph_seq_ops = { .start = g_start, .next = g_next, .stop = g_stop, diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a35925d222ba..6c0f6a8a22eb 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1949,7 +1949,7 @@ static int s_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations tracer_seq_ops = { +static const struct seq_operations tracer_seq_ops = { .start = s_start, .next = s_next, .stop = s_stop, @@ -2163,7 +2163,7 @@ static int t_show(struct seq_file *m, void *v) return 0; } -static struct seq_operations show_traces_seq_ops = { +static const struct seq_operations show_traces_seq_ops = { .start = t_start, .next = t_next, .stop = t_stop, -- cgit v1.2.2 From 02b51df1b07b4e9ca823c89284e704cadb323cd1 Mon Sep 17 00:00:00 2001 From: Scott James Remnant Date: Tue, 22 Sep 2009 16:43:44 -0700 Subject: proc connector: add event for process becoming session leader The act of a process becoming a session leader is a useful signal to a supervising init daemon such as Upstart. While a daemon will normally do this as part of the process of becoming a daemon, it is rare for its children to do so. When the children do, it is nearly always a sign that the child should be considered detached from the parent and not supervised along with it. The poster-child example is OpenSSH; the per-login children call setsid() so that they may control the pty connected to them. If the primary daemon dies or is restarted, we do not want to consider the per-login children and want to respawn the primary daemon without killing the children. This patch adds a new PROC_SID_EVENT and associated structure to the proc_event event_data union, it arranges for this to be emitted when the special PIDTYPE_SID pid is set. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Scott James Remnant Acked-by: Matt Helsley Cc: Oleg Nesterov Cc: Evgeniy Polyakov Acked-by: "David S. Miller" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index e47ee8a06135..61bb1761c7b8 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -359,8 +359,10 @@ void __set_special_pids(struct pid *pid) { struct task_struct *curr = current->group_leader; - if (task_session(curr) != pid) + if (task_session(curr) != pid) { change_pid(curr, PIDTYPE_SID, pid); + proc_sid_connector(curr); + } if (task_pgrp(curr) != pid) change_pid(curr, PIDTYPE_PGID, pid); -- cgit v1.2.2 From 1f10206cf8e945220f7220a809d8bfc15c21f9a5 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Tue, 22 Sep 2009 16:44:10 -0700 Subject: getrusage: fill ru_maxrss value Make ->ru_maxrss value in struct rusage filled accordingly to rss hiwater mark. This struct is filled as a parameter to getrusage syscall. ->ru_maxrss value is set to KBs which is the way it is done in BSD systems. /usr/bin/time (gnu time) application converts ->ru_maxrss to KBs which seems to be incorrect behavior. Maintainer of this util was notified by me with the patch which corrects it and cc'ed. To make this happen we extend struct signal_struct by two fields. The first one is ->maxrss which we use to store rss hiwater of the task. The second one is ->cmaxrss which we use to store highest rss hiwater of all task childs. These values are used in k_getrusage() to actually fill ->ru_maxrss. k_getrusage() uses current rss hiwater value directly if mm struct exists. Note: exec() clear mm->hiwater_rss, but doesn't clear sig->maxrss. it is intetionally behavior. *BSD getrusage have exec() inheriting. test programs ======================================================== getrusage.c =========== #include #include #include #include #include #include #include #include #include #include #include #include "common.h" #define err(str) perror(str), exit(1) int main(int argc, char** argv) { int status; printf("allocate 100MB\n"); consume(100); printf("testcase1: fork inherit? \n"); printf(" expect: initial.self ~= child.self\n"); show_rusage("initial"); if (__fork()) { wait(&status); } else { show_rusage("fork child"); _exit(0); } printf("\n"); printf("testcase2: fork inherit? (cont.) \n"); printf(" expect: initial.children ~= 100MB, but child.children = 0\n"); show_rusage("initial"); if (__fork()) { wait(&status); } else { show_rusage("child"); _exit(0); } printf("\n"); printf("testcase3: fork + malloc \n"); printf(" expect: child.self ~= initial.self + 50MB\n"); show_rusage("initial"); if (__fork()) { wait(&status); } else { printf("allocate +50MB\n"); consume(50); show_rusage("fork child"); _exit(0); } printf("\n"); printf("testcase4: grandchild maxrss\n"); printf(" expect: post_wait.children ~= 300MB\n"); show_rusage("initial"); if (__fork()) { wait(&status); show_rusage("post_wait"); } else { system("./child -n 0 -g 300"); _exit(0); } printf("\n"); printf("testcase5: zombie\n"); printf(" expect: pre_wait ~= initial, IOW the zombie process is not accounted.\n"); printf(" post_wait ~= 400MB, IOW wait() collect child's max_rss. \n"); show_rusage("initial"); if (__fork()) { sleep(1); /* children become zombie */ show_rusage("pre_wait"); wait(&status); show_rusage("post_wait"); } else { system("./child -n 400"); _exit(0); } printf("\n"); printf("testcase6: SIG_IGN\n"); printf(" expect: initial ~= after_zombie (child's 500MB alloc should be ignored).\n"); show_rusage("initial"); signal(SIGCHLD, SIG_IGN); if (__fork()) { sleep(1); /* children become zombie */ show_rusage("after_zombie"); } else { system("./child -n 500"); _exit(0); } printf("\n"); signal(SIGCHLD, SIG_DFL); printf("testcase7: exec (without fork) \n"); printf(" expect: initial ~= exec \n"); show_rusage("initial"); execl("./child", "child", "-v", NULL); return 0; } child.c ======= #include #include #include #include #include #include #include #include #include #include #include "common.h" int main(int argc, char** argv) { int status; int c; long consume_size = 0; long grandchild_consume_size = 0; int show = 0; while ((c = getopt(argc, argv, "n:g:v")) != -1) { switch (c) { case 'n': consume_size = atol(optarg); break; case 'v': show = 1; break; case 'g': grandchild_consume_size = atol(optarg); break; default: break; } } if (show) show_rusage("exec"); if (consume_size) { printf("child alloc %ldMB\n", consume_size); consume(consume_size); } if (grandchild_consume_size) { if (fork()) { wait(&status); } else { printf("grandchild alloc %ldMB\n", grandchild_consume_size); consume(grandchild_consume_size); exit(0); } } return 0; } common.c ======== #include #include #include #include #include #include #include #include #include #include #include #include "common.h" #define err(str) perror(str), exit(1) void show_rusage(char *prefix) { int err, err2; struct rusage rusage_self; struct rusage rusage_children; printf("%s: ", prefix); err = getrusage(RUSAGE_SELF, &rusage_self); if (!err) printf("self %ld ", rusage_self.ru_maxrss); err2 = getrusage(RUSAGE_CHILDREN, &rusage_children); if (!err2) printf("children %ld ", rusage_children.ru_maxrss); printf("\n"); } /* Some buggy OS need this worthless CPU waste. */ void make_pagefault(void) { void *addr; int size = getpagesize(); int i; for (i=0; i<1000; i++) { addr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); if (addr == MAP_FAILED) err("make_pagefault"); memset(addr, 0, size); munmap(addr, size); } } void consume(int mega) { size_t sz = mega * 1024 * 1024; void *ptr; ptr = malloc(sz); memset(ptr, 0, sz); make_pagefault(); } pid_t __fork(void) { pid_t pid; pid = fork(); make_pagefault(); return pid; } common.h ======== void show_rusage(char *prefix); void make_pagefault(void); void consume(int mega); pid_t __fork(void); FreeBSD result (expected result) ======================================================== allocate 100MB testcase1: fork inherit? expect: initial.self ~= child.self initial: self 103492 children 0 fork child: self 103540 children 0 testcase2: fork inherit? (cont.) expect: initial.children ~= 100MB, but child.children = 0 initial: self 103540 children 103540 child: self 103564 children 0 testcase3: fork + malloc expect: child.self ~= initial.self + 50MB initial: self 103564 children 103564 allocate +50MB fork child: self 154860 children 0 testcase4: grandchild maxrss expect: post_wait.children ~= 300MB initial: self 103564 children 154860 grandchild alloc 300MB post_wait: self 103564 children 308720 testcase5: zombie expect: pre_wait ~= initial, IOW the zombie process is not accounted. post_wait ~= 400MB, IOW wait() collect child's max_rss. initial: self 103564 children 308720 child alloc 400MB pre_wait: self 103564 children 308720 post_wait: self 103564 children 411312 testcase6: SIG_IGN expect: initial ~= after_zombie (child's 500MB alloc should be ignored). initial: self 103564 children 411312 child alloc 500MB after_zombie: self 103624 children 411312 testcase7: exec (without fork) expect: initial ~= exec initial: self 103624 children 411312 exec: self 103624 children 411312 Linux result (actual test result) ======================================================== allocate 100MB testcase1: fork inherit? expect: initial.self ~= child.self initial: self 102848 children 0 fork child: self 102572 children 0 testcase2: fork inherit? (cont.) expect: initial.children ~= 100MB, but child.children = 0 initial: self 102876 children 102644 child: self 102572 children 0 testcase3: fork + malloc expect: child.self ~= initial.self + 50MB initial: self 102876 children 102644 allocate +50MB fork child: self 153804 children 0 testcase4: grandchild maxrss expect: post_wait.children ~= 300MB initial: self 102876 children 153864 grandchild alloc 300MB post_wait: self 102876 children 307536 testcase5: zombie expect: pre_wait ~= initial, IOW the zombie process is not accounted. post_wait ~= 400MB, IOW wait() collect child's max_rss. initial: self 102876 children 307536 child alloc 400MB pre_wait: self 102876 children 307536 post_wait: self 102876 children 410076 testcase6: SIG_IGN expect: initial ~= after_zombie (child's 500MB alloc should be ignored). initial: self 102876 children 410076 child alloc 500MB after_zombie: self 102880 children 410076 testcase7: exec (without fork) expect: initial ~= exec initial: self 102880 children 410076 exec: self 102880 children 410076 Signed-off-by: Jiri Pirko Signed-off-by: KOSAKI Motohiro Cc: Oleg Nesterov Cc: Hugh Dickins Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 6 ++++++ kernel/fork.c | 1 + kernel/sys.c | 14 ++++++++++++++ 3 files changed, 21 insertions(+) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 61bb1761c7b8..60d6fdcc9265 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -947,6 +947,8 @@ NORET_TYPE void do_exit(long code) if (group_dead) { hrtimer_cancel(&tsk->signal->real_timer); exit_itimers(tsk->signal); + if (tsk->mm) + setmax_mm_hiwater_rss(&tsk->signal->maxrss, tsk->mm); } acct_collect(code, group_dead); if (group_dead) @@ -1210,6 +1212,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) if (likely(!traced) && likely(!task_detached(p))) { struct signal_struct *psig; struct signal_struct *sig; + unsigned long maxrss; /* * The resource counters for the group leader are in its @@ -1258,6 +1261,9 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) psig->coublock += task_io_get_oublock(p) + sig->oublock + sig->coublock; + maxrss = max(sig->maxrss, sig->cmaxrss); + if (psig->cmaxrss < maxrss) + psig->cmaxrss = maxrss; task_io_accounting_add(&psig->ioac, &p->ioac); task_io_accounting_add(&psig->ioac, &sig->ioac); spin_unlock_irq(&p->real_parent->sighand->siglock); diff --git a/kernel/fork.c b/kernel/fork.c index 1020977b57ca..7cf45812ce84 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -866,6 +866,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0; sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0; sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0; + sig->maxrss = sig->cmaxrss = 0; task_io_accounting_init(&sig->ioac); sig->sum_sched_runtime = 0; taskstats_tgid_init(sig); diff --git a/kernel/sys.c b/kernel/sys.c index ea5c3bcac881..ebcb15611728 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1338,6 +1338,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) unsigned long flags; cputime_t utime, stime; struct task_cputime cputime; + unsigned long maxrss = 0; memset((char *) r, 0, sizeof *r); utime = stime = cputime_zero; @@ -1346,6 +1347,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) utime = task_utime(current); stime = task_stime(current); accumulate_thread_rusage(p, r); + maxrss = p->signal->maxrss; goto out; } @@ -1363,6 +1365,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_majflt = p->signal->cmaj_flt; r->ru_inblock = p->signal->cinblock; r->ru_oublock = p->signal->coublock; + maxrss = p->signal->cmaxrss; if (who == RUSAGE_CHILDREN) break; @@ -1377,6 +1380,8 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) r->ru_majflt += p->signal->maj_flt; r->ru_inblock += p->signal->inblock; r->ru_oublock += p->signal->oublock; + if (maxrss < p->signal->maxrss) + maxrss = p->signal->maxrss; t = p; do { accumulate_thread_rusage(t, r); @@ -1392,6 +1397,15 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) out: cputime_to_timeval(utime, &r->ru_utime); cputime_to_timeval(stime, &r->ru_stime); + + if (who != RUSAGE_CHILDREN) { + struct mm_struct *mm = get_task_mm(p); + if (mm) { + setmax_mm_hiwater_rss(&maxrss, mm); + mmput(mm); + } + } + r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ } int getrusage(struct task_struct *p, int who, struct rusage __user *ru) -- cgit v1.2.2 From 128e8db38e30c1786498dfc011d0f9dd7f9f9266 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 22 Sep 2009 16:44:15 -0700 Subject: kallsyms: use new arch_is_kernel_text() This allows kallsyms to locate symbols that are in arch-specific text sections (such as text in Blackfin on-chip SRAM regions). Signed-off-by: Mike Frysinger Cc: Ingo Molnar Cc: Robin Getz Cc: Sam Ravnborg Cc: Peter Zijlstra Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kallsyms.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 3a29dbe7898e..8b6b8b697c68 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -59,7 +59,8 @@ static inline int is_kernel_inittext(unsigned long addr) static inline int is_kernel_text(unsigned long addr) { - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) + if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || + arch_is_kernel_text(addr)) return 1; return in_gate_area_no_task(addr); } -- cgit v1.2.2 From 2a9ad18deb2870a9968f50351a0d4b8cc2a04099 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 22 Sep 2009 16:44:16 -0700 Subject: lockdep: use new arch_is_kernel_data() This allows lockdep to locate symbols that are in arch-specific data sections (such as data in Blackfin on-chip SRAM regions). Signed-off-by: Mike Frysinger Cc: Ingo Molnar Cc: Robin Getz Cc: Sam Ravnborg Cc: Peter Zijlstra Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/lockdep.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/lockdep.c b/kernel/lockdep.c index f74d2d7aa605..3815ac1d58b2 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -578,6 +578,9 @@ static int static_obj(void *obj) if ((addr >= start) && (addr < end)) return 1; + if (arch_is_kernel_data(addr)) + return 1; + #ifdef CONFIG_SMP /* * percpu var? -- cgit v1.2.2 From d899bf7b55f503ba7d3d07ed27c3a37e270fa7db Mon Sep 17 00:00:00 2001 From: Stefani Seibold Date: Tue, 22 Sep 2009 16:45:40 -0700 Subject: procfs: provide stack information for threads A patch to give a better overview of the userland application stack usage, especially for embedded linux. Currently you are only able to dump the main process/thread stack usage which is showed in /proc/pid/status by the "VmStk" Value. But you get no information about the consumed stack memory of the the threads. There is an enhancement in the /proc//{task/*,}/*maps and which marks the vm mapping where the thread stack pointer reside with "[thread stack xxxxxxxx]". xxxxxxxx is the maximum size of stack. This is a value information, because libpthread doesn't set the start of the stack to the top of the mapped area, depending of the pthread usage. A sample output of /proc//task//maps looks like: 08048000-08049000 r-xp 00000000 03:00 8312 /opt/z 08049000-0804a000 rw-p 00001000 03:00 8312 /opt/z 0804a000-0806b000 rw-p 00000000 00:00 0 [heap] a7d12000-a7d13000 ---p 00000000 00:00 0 a7d13000-a7f13000 rw-p 00000000 00:00 0 [thread stack: 001ff4b4] a7f13000-a7f14000 ---p 00000000 00:00 0 a7f14000-a7f36000 rw-p 00000000 00:00 0 a7f36000-a8069000 r-xp 00000000 03:00 4222 /lib/libc.so.6 a8069000-a806b000 r--p 00133000 03:00 4222 /lib/libc.so.6 a806b000-a806c000 rw-p 00135000 03:00 4222 /lib/libc.so.6 a806c000-a806f000 rw-p 00000000 00:00 0 a806f000-a8083000 r-xp 00000000 03:00 14462 /lib/libpthread.so.0 a8083000-a8084000 r--p 00013000 03:00 14462 /lib/libpthread.so.0 a8084000-a8085000 rw-p 00014000 03:00 14462 /lib/libpthread.so.0 a8085000-a8088000 rw-p 00000000 00:00 0 a8088000-a80a4000 r-xp 00000000 03:00 8317 /lib/ld-linux.so.2 a80a4000-a80a5000 r--p 0001b000 03:00 8317 /lib/ld-linux.so.2 a80a5000-a80a6000 rw-p 0001c000 03:00 8317 /lib/ld-linux.so.2 afaf5000-afb0a000 rw-p 00000000 00:00 0 [stack] ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso] Also there is a new entry "stack usage" in /proc//{task/*,}/status which will you give the current stack usage in kb. A sample output of /proc/self/status looks like: Name: cat State: R (running) Tgid: 507 Pid: 507 . . . CapBnd: fffffffffffffeff voluntary_ctxt_switches: 0 nonvoluntary_ctxt_switches: 0 Stack usage: 12 kB I also fixed stack base address in /proc//{task/*,}/stat to the base address of the associated thread stack and not the one of the main process. This makes more sense. [akpm@linux-foundation.org: fs/proc/array.c now needs walk_page_range()] Signed-off-by: Stefani Seibold Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Alexey Dobriyan Cc: "Eric W. Biederman" Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 7cf45812ce84..8f45b0ebdda7 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1095,6 +1095,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, p->bts = NULL; + p->stack_start = stack_start; + /* Perform scheduler related setup. Assign this task to a CPU. */ sched_fork(p, clone_flags); -- cgit v1.2.2 From 908eedc6168bd92e89f90d89fa389065a36358fa Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 22 Sep 2009 16:45:46 -0700 Subject: walk system ram range MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Originally, walk_memory_resource() was introduced to traverse all memory of "System RAM" for detecting memory hotplug/unplug range. For doing so, flags of IORESOUCE_MEM|IORESOURCE_BUSY was used and this was enough for memory hotplug. But for using other purpose, /proc/kcore, this may includes some firmware area marked as IORESOURCE_BUSY | IORESOUCE_MEM. This patch makes the check strict to find out busy "System RAM". Note: PPC64 keeps their own walk_memory_resouce(), which walk through ppc64's lmb informaton. Because old kclist_add() is called per lmb, this patch makes no difference in behavior, finally. And this patch removes CONFIG_MEMORY_HOTPLUG check from this function. Because pfn_valid() just show "there is memmap or not* and cannot be used for "there is physical memory or not", this function is useful in generic to scan physical memory range. Signed-off-by: KAMEZAWA Hiroyuki Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: WANG Cong Cc: Américo Wang Cc: David Rientjes Cc: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/resource.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/resource.c b/kernel/resource.c index 78b087221c15..fb11a58b9594 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -223,13 +223,13 @@ int release_resource(struct resource *old) EXPORT_SYMBOL(release_resource); -#if defined(CONFIG_MEMORY_HOTPLUG) && !defined(CONFIG_ARCH_HAS_WALK_MEMORY) +#if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) /* * Finds the lowest memory reosurce exists within [res->start.res->end) - * the caller must specify res->start, res->end, res->flags. + * the caller must specify res->start, res->end, res->flags and "name". * If found, returns 0, res is overwritten, if not found, returns -1. */ -static int find_next_system_ram(struct resource *res) +static int find_next_system_ram(struct resource *res, char *name) { resource_size_t start, end; struct resource *p; @@ -245,6 +245,8 @@ static int find_next_system_ram(struct resource *res) /* system ram is just marked as IORESOURCE_MEM */ if (p->flags != res->flags) continue; + if (name && strcmp(p->name, name)) + continue; if (p->start > end) { p = NULL; break; @@ -262,19 +264,26 @@ static int find_next_system_ram(struct resource *res) res->end = p->end; return 0; } -int -walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg, - int (*func)(unsigned long, unsigned long, void *)) + +/* + * This function calls callback against all memory range of "System RAM" + * which are marked as IORESOURCE_MEM and IORESOUCE_BUSY. + * Now, this function is only for "System RAM". + */ +int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages, + void *arg, int (*func)(unsigned long, unsigned long, void *)) { struct resource res; unsigned long pfn, len; u64 orig_end; int ret = -1; + res.start = (u64) start_pfn << PAGE_SHIFT; res.end = ((u64)(start_pfn + nr_pages) << PAGE_SHIFT) - 1; res.flags = IORESOURCE_MEM | IORESOURCE_BUSY; orig_end = res.end; - while ((res.start < res.end) && (find_next_system_ram(&res) >= 0)) { + while ((res.start < res.end) && + (find_next_system_ram(&res, "System RAM") >= 0)) { pfn = (unsigned long)(res.start >> PAGE_SHIFT); len = (unsigned long)((res.end + 1 - res.start) >> PAGE_SHIFT); ret = (*func)(pfn, len, arg); -- cgit v1.2.2 From 74908a0009eb36054190ab80deb9671014efed96 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 17 Sep 2009 17:47:12 -0700 Subject: include/linux/cred.h: fix build mips allmodconfig: include/linux/cred.h: In function `creds_are_invalid': include/linux/cred.h:187: error: `PAGE_SIZE' undeclared (first use in this function) include/linux/cred.h:187: error: (Each undeclared identifier is reported only once include/linux/cred.h:187: error: for each function it appears in.) Fixes commit b6dff3ec5e116e3af6f537d4caedcad6b9e5082a Author: David Howells AuthorDate: Fri Nov 14 10:39:16 2008 +1100 Commit: James Morris CommitDate: Fri Nov 14 10:39:16 2008 +1100 CRED: Separate task security context from task_struct I think. It's way too large to be inlined anyway. Dunno if this needs an EXPORT_SYMBOL() yet. Cc: David Howells Cc: James Morris Cc: Serge Hallyn Signed-off-by: Andrew Morton Acked-by: David Howells Signed-off-by: James Morris --- kernel/cred.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'kernel') diff --git a/kernel/cred.c b/kernel/cred.c index d7f7a01082eb..70bda79fae24 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -782,6 +782,24 @@ EXPORT_SYMBOL(set_create_files_as); #ifdef CONFIG_DEBUG_CREDENTIALS +bool creds_are_invalid(const struct cred *cred) +{ + if (cred->magic != CRED_MAGIC) + return true; + if (atomic_read(&cred->usage) < atomic_read(&cred->subscribers)) + return true; +#ifdef CONFIG_SECURITY_SELINUX + if (selinux_is_enabled()) { + if ((unsigned long) cred->security < PAGE_SIZE) + return true; + if ((*(u32 *)cred->security & 0xffffff00) == + (POISON_FREE << 24 | POISON_FREE << 16 | POISON_FREE << 8)) + return true; + } +#endif + return false; +} + /* * dump invalid credentials */ -- cgit v1.2.2 From 764db03fee50f7a3de91de80ef4a943f0d720801 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 18 Sep 2009 11:06:47 -0700 Subject: creds_are_invalid() needs to be exported for use by modules: ERROR: "creds_are_invalid" [fs/cachefiles/cachefiles.ko] undefined! Signed-off-by: Randy Dunlap Cc: David Howells Cc: James Morris Cc: Serge Hallyn Signed-off-by: Andrew Morton Signed-off-by: James Morris --- kernel/cred.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/cred.c b/kernel/cred.c index 70bda79fae24..dd76cfe5f5b0 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -799,6 +799,7 @@ bool creds_are_invalid(const struct cred *cred) #endif return false; } +EXPORT_SYMBOL(creds_are_invalid); /* * dump invalid credentials -- cgit v1.2.2 From 79f5599772ac2f138d7a75b8f3f06a93f09c75f7 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 15 Jun 2009 14:58:26 +0800 Subject: cpumask: use zalloc_cpumask_var() where possible Remove open-coded zalloc_cpumask_var() and zalloc_cpumask_var_node(). Signed-off-by: Li Zefan Signed-off-by: Rusty Russell --- kernel/trace/trace.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6c0f6a8a22eb..411af37f4be4 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1984,11 +1984,9 @@ __tracing_open(struct inode *inode, struct file *file) if (current_trace) *iter->trace = *current_trace; - if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) + if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) goto fail; - cpumask_clear(iter->started); - if (current_trace && current_trace->print_max) iter->tr = &max_tr; else @@ -4389,7 +4387,7 @@ __init static int tracer_alloc_buffers(void) if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL)) goto out_free_buffer_mask; - if (!alloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL)) + if (!zalloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL)) goto out_free_tracing_cpumask; /* To save memory, keep the ring buffer size to its minimum */ @@ -4400,7 +4398,6 @@ __init static int tracer_alloc_buffers(void) cpumask_copy(tracing_buffer_mask, cpu_possible_mask); cpumask_copy(tracing_cpumask, cpu_all_mask); - cpumask_clear(tracing_reader_cpumask); /* TODO: make the number of buffers hot pluggable with CPUS */ global_trace.buffer = ring_buffer_alloc(ring_buf_size, -- cgit v1.2.2 From 0748bd01773395003208996c4c0b3f80caf80976 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 24 Sep 2009 09:34:46 -0600 Subject: cpumask: remove arch_send_call_function_ipi Now everyone is converted to arch_send_call_function_ipi_mask, remove the shim and the #defines. Signed-off-by: Rusty Russell --- kernel/smp.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'kernel') diff --git a/kernel/smp.c b/kernel/smp.c index fd47a256a24e..c9d1c7835c2f 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -347,13 +347,6 @@ void __smp_call_function_single(int cpu, struct call_single_data *data, generic_exec_single(cpu, data, wait); } -/* Deprecated: shim for archs using old arch_send_call_function_ipi API. */ - -#ifndef arch_send_call_function_ipi_mask -# define arch_send_call_function_ipi_mask(maskp) \ - arch_send_call_function_ipi(*(maskp)) -#endif - /** * smp_call_function_many(): Run a function on a set of other CPUs. * @mask: The set of cpus to run on (only runs on online subset). -- cgit v1.2.2 From 95e0d86badc410d525ea7218fd32df7bfbf9c837 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 24 Sep 2009 01:02:55 +0200 Subject: Revert "kmod: fix race in usermodehelper code" This reverts commit c02e3f361c7 ("kmod: fix race in usermodehelper code") The patch is wrong. UMH_WAIT_EXEC is called with VFORK what ensures that the child finishes prior returing back to the parent. No race. In fact, the patch makes it even worse because it does the thing it claims not do: - It calls ->complete() on UMH_WAIT_EXEC - the complete() callback may de-allocated subinfo as seen in the following call chain: [] (__link_path_walk+0x20/0xeb4) from [] (path_walk+0x48/0x94) [] (path_walk+0x48/0x94) from [] (do_path_lookup+0x24/0x4c) [] (do_path_lookup+0x24/0x4c) from [] (do_filp_open+0xa4/0x83c) [] (do_filp_open+0xa4/0x83c) from [] (open_exec+0x24/0xe0) [] (open_exec+0x24/0xe0) from [] (do_execve+0x7c/0x2e4) [] (do_execve+0x7c/0x2e4) from [] (kernel_execve+0x34/0x80) [] (kernel_execve+0x34/0x80) from [] (____call_usermodehelper+0x130/0x148) [] (____call_usermodehelper+0x130/0x148) from [] (kernel_thread_exit+0x0/0x8) and the path pointer was NULL. Good that ARM's kernel_execve() doesn't check the pointer for NULL or else I wouldn't notice it. The only race there might be is with UMH_NO_WAIT but it is too late for me to investigate it now. UMH_WAIT_PROC could probably also use VFORK and we could save one exec. So the only race I see is with UMH_NO_WAIT and recent scheduler changes where the child does not always run first might have trigger here something but as I said, it is late.... Signed-off-by: Sebastian Andrzej Siewior Acked-by: Neil Horman Signed-off-by: Linus Torvalds --- kernel/kmod.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/kmod.c b/kernel/kmod.c index 689d20f39305..9fcb53a11f87 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -143,7 +143,6 @@ struct subprocess_info { static int ____call_usermodehelper(void *data) { struct subprocess_info *sub_info = data; - enum umh_wait wait = sub_info->wait; int retval; BUG_ON(atomic_read(&sub_info->cred->usage) != 1); @@ -185,14 +184,10 @@ static int ____call_usermodehelper(void *data) */ set_user_nice(current, 0); - if (wait == UMH_WAIT_EXEC) - complete(sub_info->complete); - retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp); /* Exec failed? */ - if (wait != UMH_WAIT_EXEC) - sub_info->retval = retval; + sub_info->retval = retval; do_exit(0); } @@ -271,14 +266,16 @@ static void __call_usermodehelper(struct work_struct *work) switch (wait) { case UMH_NO_WAIT: - case UMH_WAIT_EXEC: break; case UMH_WAIT_PROC: if (pid > 0) break; sub_info->retval = pid; - break; + /* FALLTHROUGH */ + + case UMH_WAIT_EXEC: + complete(sub_info->complete); } } -- cgit v1.2.2 From 2bcd57ab61e7cabed626226a3771617981c11ce1 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Thu, 24 Sep 2009 04:22:25 +0400 Subject: headers: utsname.h redux * remove asm/atomic.h inclusion from linux/utsname.h -- not needed after kref conversion * remove linux/utsname.h inclusion from files which do not need it NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however due to some personality stuff it _is_ needed -- cowardly leave ELF-related headers and files alone. Signed-off-by: Alexey Dobriyan Signed-off-by: Linus Torvalds --- kernel/power/swap.c | 1 - kernel/sysctl.c | 1 - kernel/uid16.c | 1 - 3 files changed, 3 deletions(-) (limited to 'kernel') diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 8ba052c86d48..b101cdc4df3f 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -13,7 +13,6 @@ #include #include -#include #include #include #include diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 0dfaa47d7cb6..7f4f57bea4ce 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -26,7 +26,6 @@ #include #include #include -#include #include #include #include diff --git a/kernel/uid16.c b/kernel/uid16.c index 0314501688b9..419209893d87 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -4,7 +4,6 @@ */ #include -#include #include #include #include -- cgit v1.2.2 From e08b061ec0fca1f63bb1006bf1edc0556f36d0ae Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 7 Aug 2009 16:54:23 -0400 Subject: Audit: reorganize struct audit_watch to save 8 bytes pahole showed that struct audit_watch had two holes: struct audit_watch { atomic_t count; /* 0 4 */ /* XXX 4 bytes hole, try to pack */ char * path; /* 8 8 */ dev_t dev; /* 16 4 */ /* XXX 4 bytes hole, try to pack */ long unsigned int ino; /* 24 8 */ struct audit_parent * parent; /* 32 8 */ struct list_head wlist; /* 40 16 */ struct list_head rules; /* 56 16 */ /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */ /* size: 72, cachelines: 2, members: 7 */ /* sum members: 64, holes: 2, sum holes: 8 */ /* last cacheline: 8 bytes */ }; /* definitions: 1 */ by moving dev after count we save 8 bytes, actually improving cacheline usage. There are typically very few of these in the kernel so it won't be a large savings, but it's a good thing no matter what. Signed-off-by: Eric Paris Signed-off-by: Al Viro --- kernel/audit_watch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index 0e96dbc60ea9..cc7e87936cbc 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -45,8 +45,8 @@ struct audit_watch { atomic_t count; /* reference count */ - char *path; /* insertion path */ dev_t dev; /* associated superblock device */ + char *path; /* insertion path */ unsigned long ino; /* associated inode number */ struct audit_parent *parent; /* associated parent */ struct list_head wlist; /* entry in parent->watches list */ -- cgit v1.2.2 From 44e51a1b7852bd421ff5303c64dcc5c8524c21ef Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 7 Aug 2009 16:54:29 -0400 Subject: Audit: rearrange audit_context to save 16 bytes per struct pahole pointed out that on x86_64 struct audit_context can be rearrainged to save 16 bytes per struct. Since we have an audit_context per task this can acually be a pretty significant gain. Signed-off-by: Eric Paris Signed-off-by: Al Viro --- kernel/auditsc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 68d3c6a0ecd6..267e484f0198 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -168,12 +168,12 @@ struct audit_context { int in_syscall; /* 1 if task is in a syscall */ enum audit_state state, current_state; unsigned int serial; /* serial number for record */ - struct timespec ctime; /* time of syscall entry */ int major; /* syscall number */ + struct timespec ctime; /* time of syscall entry */ unsigned long argv[4]; /* syscall arguments */ - int return_valid; /* return code is valid */ long return_code;/* syscall return code */ u64 prio; + int return_valid; /* return code is valid */ int name_count; struct audit_names names[AUDIT_NAMES]; char * filterkey; /* key for rule that triggered record */ @@ -198,8 +198,8 @@ struct audit_context { char target_comm[TASK_COMM_LEN]; struct audit_tree_refs *trees, *first_trees; - int tree_count; struct list_head killed_trees; + int tree_count; int type; union { -- cgit v1.2.2 From 939cbf260c1abce6cad4b95ea4ba9f5132b660b3 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 23 Sep 2009 13:46:00 -0400 Subject: Audit: send signal info if selinux is disabled Audit will not respond to signal requests if selinux is disabled since it is unable to translate the 0 sid from the sending process to a context. This patch just doesn't send the context info if there isn't any. Signed-off-by: Eric Paris Signed-off-by: Al Viro --- kernel/audit.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/audit.c b/kernel/audit.c index defc2e6f1e3b..5feed232be9d 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -855,18 +855,24 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) break; } case AUDIT_SIGNAL_INFO: - err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); - if (err) - return err; + len = 0; + if (audit_sig_sid) { + err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); + if (err) + return err; + } sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); if (!sig_data) { - security_release_secctx(ctx, len); + if (audit_sig_sid) + security_release_secctx(ctx, len); return -ENOMEM; } sig_data->uid = audit_sig_uid; sig_data->pid = audit_sig_pid; - memcpy(sig_data->ctx, ctx, len); - security_release_secctx(ctx, len); + if (audit_sig_sid) { + memcpy(sig_data->ctx, ctx, len); + security_release_secctx(ctx, len); + } audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, 0, 0, sig_data, sizeof(*sig_data) + len); kfree(sig_data); -- cgit v1.2.2 From 57f1f0874f426a9bdfc5cd3f886113dd5cd17834 Mon Sep 17 00:00:00 2001 From: Zhaolei Date: Wed, 23 Sep 2009 15:56:10 -0700 Subject: time: add function to convert between calendar time and broken-down time for universal use There are many similar code in kernel for one object: convert time between calendar time and broken-down time. Here is some source I found: fs/ncpfs/dir.c fs/smbfs/proc.c fs/fat/misc.c fs/udf/udftime.c fs/cifs/netmisc.c net/netfilter/xt_time.c drivers/scsi/ips.c drivers/input/misc/hp_sdc_rtc.c drivers/rtc/rtc-lib.c arch/ia64/hp/sim/boot/fw-emu.c arch/m68k/mac/misc.c arch/powerpc/kernel/time.c arch/parisc/include/asm/rtc.h ... We can make a common function for this type of conversion, At least we can get following benefit: 1: Make kernel simple and unify 2: Easy to fix bug in converting code 3: Reduce clone of code in future For example, I'm trying to make ftrace display walltime, this patch will make me easy. This code is based on code from glibc-2.6 Signed-off-by: Zhao Lei Cc: OGAWA Hirofumi Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Pavel Machek Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/time/Makefile | 2 +- kernel/time/timeconv.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 128 insertions(+), 1 deletion(-) create mode 100644 kernel/time/timeconv.c (limited to 'kernel') diff --git a/kernel/time/Makefile b/kernel/time/Makefile index 0b0a6366c9d4..ee266620b06c 100644 --- a/kernel/time/Makefile +++ b/kernel/time/Makefile @@ -1,4 +1,4 @@ -obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o +obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o timecompare.o timeconv.o obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD) += clockevents.o obj-$(CONFIG_GENERIC_CLOCKEVENTS) += tick-common.o diff --git a/kernel/time/timeconv.c b/kernel/time/timeconv.c new file mode 100644 index 000000000000..86628e755f38 --- /dev/null +++ b/kernel/time/timeconv.c @@ -0,0 +1,127 @@ +/* + * Copyright (C) 1993, 1994, 1995, 1996, 1997 Free Software Foundation, Inc. + * This file is part of the GNU C Library. + * Contributed by Paul Eggert (eggert@twinsun.com). + * + * The GNU C Library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * The GNU C Library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with the GNU C Library; see the file COPYING.LIB. If not, + * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +/* + * Converts the calendar time to broken-down time representation + * Based on code from glibc-2.6 + * + * 2009-7-14: + * Moved from glibc-2.6 to kernel by Zhaolei + */ + +#include +#include + +/* + * Nonzero if YEAR is a leap year (every 4 years, + * except every 100th isn't, and every 400th is). + */ +static int __isleap(long year) +{ + return (year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0); +} + +/* do a mathdiv for long type */ +static long math_div(long a, long b) +{ + return a / b - (a % b < 0); +} + +/* How many leap years between y1 and y2, y1 must less or equal to y2 */ +static long leaps_between(long y1, long y2) +{ + long leaps1 = math_div(y1 - 1, 4) - math_div(y1 - 1, 100) + + math_div(y1 - 1, 400); + long leaps2 = math_div(y2 - 1, 4) - math_div(y2 - 1, 100) + + math_div(y2 - 1, 400); + return leaps2 - leaps1; +} + +/* How many days come before each month (0-12). */ +static const unsigned short __mon_yday[2][13] = { + /* Normal years. */ + {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365}, + /* Leap years. */ + {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366} +}; + +#define SECS_PER_HOUR (60 * 60) +#define SECS_PER_DAY (SECS_PER_HOUR * 24) + +/** + * time_to_tm - converts the calendar time to local broken-down time + * + * @totalsecs the number of seconds elapsed since 00:00:00 on January 1, 1970, + * Coordinated Universal Time (UTC). + * @offset offset seconds adding to totalsecs. + * @result pointer to struct tm variable to receive broken-down time + */ +void time_to_tm(time_t totalsecs, int offset, struct tm *result) +{ + long days, rem, y; + const unsigned short *ip; + + days = totalsecs / SECS_PER_DAY; + rem = totalsecs % SECS_PER_DAY; + rem += offset; + while (rem < 0) { + rem += SECS_PER_DAY; + --days; + } + while (rem >= SECS_PER_DAY) { + rem -= SECS_PER_DAY; + ++days; + } + + result->tm_hour = rem / SECS_PER_HOUR; + rem %= SECS_PER_HOUR; + result->tm_min = rem / 60; + result->tm_sec = rem % 60; + + /* January 1, 1970 was a Thursday. */ + result->tm_wday = (4 + days) % 7; + if (result->tm_wday < 0) + result->tm_wday += 7; + + y = 1970; + + while (days < 0 || days >= (__isleap(y) ? 366 : 365)) { + /* Guess a corrected year, assuming 365 days per year. */ + long yg = y + math_div(days, 365); + + /* Adjust DAYS and Y to match the guessed year. */ + days -= (yg - y) * 365 + leaps_between(y, yg); + y = yg; + } + + result->tm_year = y - 1900; + + result->tm_yday = days; + + ip = __mon_yday[__isleap(y)]; + for (y = 11; days < ip[y]; y--) + continue; + days -= ip[y]; + + result->tm_mon = y; + result->tm_mday = days + 1; +} +EXPORT_SYMBOL(time_to_tm); -- cgit v1.2.2 From 34f77a90f79fca31802c2e942bd73f7f557fe28c Mon Sep 17 00:00:00 2001 From: Xiaotian Feng Date: Wed, 23 Sep 2009 15:56:18 -0700 Subject: cgroups: make unlock sequence in cgroup_get_sb consistent Make the last unlock sequence consistent with previous unlock sequeue. Acked-by: Balbir Singh Acked-by: Paul Menage Signed-off-by: Xiaotian Feng Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index cd83d9933b6b..f5281aadbcab 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1155,8 +1155,8 @@ static int cgroup_get_sb(struct file_system_type *fs_type, BUG_ON(root->number_of_cgroups != 1); cgroup_populate_dir(root_cgrp); - mutex_unlock(&inode->i_mutex); mutex_unlock(&cgroup_mutex); + mutex_unlock(&inode->i_mutex); } simple_set_mnt(mnt, sb); -- cgit v1.2.2 From c6d57f3312a6619d47c5557b5f6154a74d04ff80 Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Wed, 23 Sep 2009 15:56:19 -0700 Subject: cgroups: support named cgroups hierarchies To simplify referring to cgroup hierarchies in mount statements, and to allow disambiguation in the presence of empty hierarchies and multiply-bindable subsystems this patch adds support for naming a new cgroup hierarchy via the "name=" mount option A pre-existing hierarchy may be specified by either name or by subsystems; a hierarchy's name cannot be changed by a remount operation. Example usage: # To create a hierarchy called "foo" containing the "cpu" subsystem mount -t cgroup -oname=foo,cpu cgroup /mnt/cgroup1 # To mount the "foo" hierarchy on a second location mount -t cgroup -oname=foo cgroup /mnt/cgroup2 Signed-off-by: Paul Menage Reviewed-by: Li Zefan Cc: KAMEZAWA Hiroyuki Cc: Balbir Singh Cc: Dhaval Giani Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 184 +++++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 136 insertions(+), 48 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index f5281aadbcab..03204044622f 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -23,6 +23,7 @@ */ #include +#include #include #include #include @@ -60,6 +61,8 @@ static struct cgroup_subsys *subsys[] = { #include }; +#define MAX_CGROUP_ROOT_NAMELEN 64 + /* * A cgroupfs_root represents the root of a cgroup hierarchy, * and may be associated with a superblock to form an active @@ -94,6 +97,9 @@ struct cgroupfs_root { /* The path to use for release notifications. */ char release_agent_path[PATH_MAX]; + + /* The name for this hierarchy - may be empty */ + char name[MAX_CGROUP_ROOT_NAMELEN]; }; /* @@ -841,6 +847,8 @@ static int cgroup_show_options(struct seq_file *seq, struct vfsmount *vfs) seq_puts(seq, ",noprefix"); if (strlen(root->release_agent_path)) seq_printf(seq, ",release_agent=%s", root->release_agent_path); + if (strlen(root->name)) + seq_printf(seq, ",name=%s", root->name); mutex_unlock(&cgroup_mutex); return 0; } @@ -849,6 +857,9 @@ struct cgroup_sb_opts { unsigned long subsys_bits; unsigned long flags; char *release_agent; + char *name; + + struct cgroupfs_root *new_root; }; /* Convert a hierarchy specifier into a bitmask of subsystems and @@ -863,9 +874,7 @@ static int parse_cgroupfs_options(char *data, mask = ~(1UL << cpuset_subsys_id); #endif - opts->subsys_bits = 0; - opts->flags = 0; - opts->release_agent = NULL; + memset(opts, 0, sizeof(*opts)); while ((token = strsep(&o, ",")) != NULL) { if (!*token) @@ -885,11 +894,33 @@ static int parse_cgroupfs_options(char *data, /* Specifying two release agents is forbidden */ if (opts->release_agent) return -EINVAL; - opts->release_agent = kzalloc(PATH_MAX, GFP_KERNEL); + opts->release_agent = + kstrndup(token + 14, PATH_MAX, GFP_KERNEL); if (!opts->release_agent) return -ENOMEM; - strncpy(opts->release_agent, token + 14, PATH_MAX - 1); - opts->release_agent[PATH_MAX - 1] = 0; + } else if (!strncmp(token, "name=", 5)) { + int i; + const char *name = token + 5; + /* Can't specify an empty name */ + if (!strlen(name)) + return -EINVAL; + /* Must match [\w.-]+ */ + for (i = 0; i < strlen(name); i++) { + char c = name[i]; + if (isalnum(c)) + continue; + if ((c == '.') || (c == '-') || (c == '_')) + continue; + return -EINVAL; + } + /* Specifying two names is forbidden */ + if (opts->name) + return -EINVAL; + opts->name = kstrndup(name, + MAX_CGROUP_ROOT_NAMELEN, + GFP_KERNEL); + if (!opts->name) + return -ENOMEM; } else { struct cgroup_subsys *ss; int i; @@ -916,7 +947,7 @@ static int parse_cgroupfs_options(char *data, return -EINVAL; /* We can't have an empty hierarchy */ - if (!opts->subsys_bits) + if (!opts->subsys_bits && !opts->name) return -EINVAL; return 0; @@ -944,6 +975,12 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) goto out_unlock; } + /* Don't allow name to change at remount */ + if (opts.name && strcmp(opts.name, root->name)) { + ret = -EINVAL; + goto out_unlock; + } + ret = rebind_subsystems(root, opts.subsys_bits); if (ret) goto out_unlock; @@ -955,6 +992,7 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) strcpy(root->release_agent_path, opts.release_agent); out_unlock: kfree(opts.release_agent); + kfree(opts.name); mutex_unlock(&cgroup_mutex); mutex_unlock(&cgrp->dentry->d_inode->i_mutex); unlock_kernel(); @@ -977,6 +1015,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) INIT_LIST_HEAD(&cgrp->pids_list); init_rwsem(&cgrp->pids_mutex); } + static void init_cgroup_root(struct cgroupfs_root *root) { struct cgroup *cgrp = &root->top_cgroup; @@ -990,31 +1029,59 @@ static void init_cgroup_root(struct cgroupfs_root *root) static int cgroup_test_super(struct super_block *sb, void *data) { - struct cgroupfs_root *new = data; + struct cgroup_sb_opts *opts = data; struct cgroupfs_root *root = sb->s_fs_info; - /* First check subsystems */ - if (new->subsys_bits != root->subsys_bits) - return 0; + /* If we asked for a name then it must match */ + if (opts->name && strcmp(opts->name, root->name)) + return 0; - /* Next check flags */ - if (new->flags != root->flags) + /* If we asked for subsystems then they must match */ + if (opts->subsys_bits && (opts->subsys_bits != root->subsys_bits)) return 0; return 1; } +static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) +{ + struct cgroupfs_root *root; + + /* Empty hierarchies aren't supported */ + if (!opts->subsys_bits) + return NULL; + + root = kzalloc(sizeof(*root), GFP_KERNEL); + if (!root) + return ERR_PTR(-ENOMEM); + + init_cgroup_root(root); + root->subsys_bits = opts->subsys_bits; + root->flags = opts->flags; + if (opts->release_agent) + strcpy(root->release_agent_path, opts->release_agent); + if (opts->name) + strcpy(root->name, opts->name); + return root; +} + static int cgroup_set_super(struct super_block *sb, void *data) { int ret; - struct cgroupfs_root *root = data; + struct cgroup_sb_opts *opts = data; + + /* If we don't have a new root, we can't set up a new sb */ + if (!opts->new_root) + return -EINVAL; + + BUG_ON(!opts->subsys_bits); ret = set_anon_super(sb, NULL); if (ret) return ret; - sb->s_fs_info = root; - root->sb = sb; + sb->s_fs_info = opts->new_root; + opts->new_root->sb = sb; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; @@ -1051,48 +1118,43 @@ static int cgroup_get_sb(struct file_system_type *fs_type, void *data, struct vfsmount *mnt) { struct cgroup_sb_opts opts; + struct cgroupfs_root *root; int ret = 0; struct super_block *sb; - struct cgroupfs_root *root; - struct list_head tmp_cg_links; + struct cgroupfs_root *new_root; /* First find the desired set of subsystems */ ret = parse_cgroupfs_options(data, &opts); - if (ret) { - kfree(opts.release_agent); - return ret; - } - - root = kzalloc(sizeof(*root), GFP_KERNEL); - if (!root) { - kfree(opts.release_agent); - return -ENOMEM; - } + if (ret) + goto out_err; - init_cgroup_root(root); - root->subsys_bits = opts.subsys_bits; - root->flags = opts.flags; - if (opts.release_agent) { - strcpy(root->release_agent_path, opts.release_agent); - kfree(opts.release_agent); + /* + * Allocate a new cgroup root. We may not need it if we're + * reusing an existing hierarchy. + */ + new_root = cgroup_root_from_opts(&opts); + if (IS_ERR(new_root)) { + ret = PTR_ERR(new_root); + goto out_err; } + opts.new_root = new_root; - sb = sget(fs_type, cgroup_test_super, cgroup_set_super, root); - + /* Locate an existing or new sb for this hierarchy */ + sb = sget(fs_type, cgroup_test_super, cgroup_set_super, &opts); if (IS_ERR(sb)) { - kfree(root); - return PTR_ERR(sb); + ret = PTR_ERR(sb); + kfree(opts.new_root); + goto out_err; } - if (sb->s_fs_info != root) { - /* Reusing an existing superblock */ - BUG_ON(sb->s_root == NULL); - kfree(root); - root = NULL; - } else { - /* New superblock */ + root = sb->s_fs_info; + BUG_ON(!root); + if (root == opts.new_root) { + /* We used the new root structure, so this is a new hierarchy */ + struct list_head tmp_cg_links; struct cgroup *root_cgrp = &root->top_cgroup; struct inode *inode; + struct cgroupfs_root *existing_root; int i; BUG_ON(sb->s_root != NULL); @@ -1105,6 +1167,18 @@ static int cgroup_get_sb(struct file_system_type *fs_type, mutex_lock(&inode->i_mutex); mutex_lock(&cgroup_mutex); + if (strlen(root->name)) { + /* Check for name clashes with existing mounts */ + for_each_active_root(existing_root) { + if (!strcmp(existing_root->name, root->name)) { + ret = -EBUSY; + mutex_unlock(&cgroup_mutex); + mutex_unlock(&inode->i_mutex); + goto drop_new_super; + } + } + } + /* * We're accessing css_set_count without locking * css_set_lock here, but that's OK - it can only be @@ -1123,7 +1197,8 @@ static int cgroup_get_sb(struct file_system_type *fs_type, if (ret == -EBUSY) { mutex_unlock(&cgroup_mutex); mutex_unlock(&inode->i_mutex); - goto free_cg_links; + free_cg_links(&tmp_cg_links); + goto drop_new_super; } /* EBUSY should be the only error here */ @@ -1157,15 +1232,25 @@ static int cgroup_get_sb(struct file_system_type *fs_type, cgroup_populate_dir(root_cgrp); mutex_unlock(&cgroup_mutex); mutex_unlock(&inode->i_mutex); + } else { + /* + * We re-used an existing hierarchy - the new root (if + * any) is not needed + */ + kfree(opts.new_root); } simple_set_mnt(mnt, sb); + kfree(opts.release_agent); + kfree(opts.name); return 0; - free_cg_links: - free_cg_links(&tmp_cg_links); drop_new_super: deactivate_locked_super(sb); + out_err: + kfree(opts.release_agent); + kfree(opts.name); + return ret; } @@ -2992,6 +3077,9 @@ static int proc_cgroup_show(struct seq_file *m, void *v) seq_printf(m, "%lu:", root->subsys_bits); for_each_subsys(root, ss) seq_printf(m, "%s%s", count++ ? "," : "", ss->name); + if (strlen(root->name)) + seq_printf(m, "%sname=%s", count ? "," : "", + root->name); seq_putc(m, ':'); get_first_subsys(&root->top_cgroup, NULL, &subsys_id); cgrp = task_cgroup(tsk, subsys_id); -- cgit v1.2.2 From fe6934354f8e287275500cd6ec73826d4d6ad457 Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Wed, 23 Sep 2009 15:56:20 -0700 Subject: cgroups: move the cgroup debug subsys into cgroup.c to access internal state While it's architecturally clean to have the cgroup debug subsystem be completely independent of the cgroups framework, it limits its usefulness for debugging the contents of internal data structures. Move the debug subsystem code into the scope of all the cgroups data structures to make more detailed debugging possible. Signed-off-by: Paul Menage Reviewed-by: Li Zefan Reviewed-by: KAMEZAWA Hiroyuki Cc: Balbir Singh Cc: Dhaval Giani Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/Makefile | 1 - kernel/cgroup.c | 88 ++++++++++++++++++++++++++++++++++++++++++ kernel/cgroup_debug.c | 105 -------------------------------------------------- 3 files changed, 88 insertions(+), 106 deletions(-) delete mode 100644 kernel/cgroup_debug.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 187c89b4783d..b8d4cd8ac0b9 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -58,7 +58,6 @@ obj-$(CONFIG_KEXEC) += kexec.o obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o obj-$(CONFIG_COMPAT) += compat.o obj-$(CONFIG_CGROUPS) += cgroup.o -obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o obj-$(CONFIG_CGROUP_FREEZER) += cgroup_freezer.o obj-$(CONFIG_CPUSETS) += cpuset.o obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 03204044622f..ccec722213a4 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3781,3 +3781,91 @@ css_get_next(struct cgroup_subsys *ss, int id, return ret; } +#ifdef CONFIG_CGROUP_DEBUG +static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss, + struct cgroup *cont) +{ + struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL); + + if (!css) + return ERR_PTR(-ENOMEM); + + return css; +} + +static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont) +{ + kfree(cont->subsys[debug_subsys_id]); +} + +static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft) +{ + return atomic_read(&cont->count); +} + +static u64 debug_taskcount_read(struct cgroup *cont, struct cftype *cft) +{ + return cgroup_task_count(cont); +} + +static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft) +{ + return (u64)(unsigned long)current->cgroups; +} + +static u64 current_css_set_refcount_read(struct cgroup *cont, + struct cftype *cft) +{ + u64 count; + + rcu_read_lock(); + count = atomic_read(¤t->cgroups->refcount); + rcu_read_unlock(); + return count; +} + +static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft) +{ + return test_bit(CGRP_RELEASABLE, &cgrp->flags); +} + +static struct cftype debug_files[] = { + { + .name = "cgroup_refcount", + .read_u64 = cgroup_refcount_read, + }, + { + .name = "taskcount", + .read_u64 = debug_taskcount_read, + }, + + { + .name = "current_css_set", + .read_u64 = current_css_set_read, + }, + + { + .name = "current_css_set_refcount", + .read_u64 = current_css_set_refcount_read, + }, + + { + .name = "releasable", + .read_u64 = releasable_read, + }, +}; + +static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont) +{ + return cgroup_add_files(cont, ss, debug_files, + ARRAY_SIZE(debug_files)); +} + +struct cgroup_subsys debug_subsys = { + .name = "debug", + .create = debug_create, + .destroy = debug_destroy, + .populate = debug_populate, + .subsys_id = debug_subsys_id, +}; +#endif /* CONFIG_CGROUP_DEBUG */ diff --git a/kernel/cgroup_debug.c b/kernel/cgroup_debug.c deleted file mode 100644 index 0c92d797baa6..000000000000 --- a/kernel/cgroup_debug.c +++ /dev/null @@ -1,105 +0,0 @@ -/* - * kernel/cgroup_debug.c - Example cgroup subsystem that - * exposes debug info - * - * Copyright (C) Google Inc, 2007 - * - * Developed by Paul Menage (menage@google.com) - * - */ - -#include -#include -#include -#include - -#include - -static struct cgroup_subsys_state *debug_create(struct cgroup_subsys *ss, - struct cgroup *cont) -{ - struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL); - - if (!css) - return ERR_PTR(-ENOMEM); - - return css; -} - -static void debug_destroy(struct cgroup_subsys *ss, struct cgroup *cont) -{ - kfree(cont->subsys[debug_subsys_id]); -} - -static u64 cgroup_refcount_read(struct cgroup *cont, struct cftype *cft) -{ - return atomic_read(&cont->count); -} - -static u64 taskcount_read(struct cgroup *cont, struct cftype *cft) -{ - u64 count; - - count = cgroup_task_count(cont); - return count; -} - -static u64 current_css_set_read(struct cgroup *cont, struct cftype *cft) -{ - return (u64)(long)current->cgroups; -} - -static u64 current_css_set_refcount_read(struct cgroup *cont, - struct cftype *cft) -{ - u64 count; - - rcu_read_lock(); - count = atomic_read(¤t->cgroups->refcount); - rcu_read_unlock(); - return count; -} - -static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft) -{ - return test_bit(CGRP_RELEASABLE, &cgrp->flags); -} - -static struct cftype files[] = { - { - .name = "cgroup_refcount", - .read_u64 = cgroup_refcount_read, - }, - { - .name = "taskcount", - .read_u64 = taskcount_read, - }, - - { - .name = "current_css_set", - .read_u64 = current_css_set_read, - }, - - { - .name = "current_css_set_refcount", - .read_u64 = current_css_set_refcount_read, - }, - - { - .name = "releasable", - .read_u64 = releasable_read, - }, -}; - -static int debug_populate(struct cgroup_subsys *ss, struct cgroup *cont) -{ - return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files)); -} - -struct cgroup_subsys debug_subsys = { - .name = "debug", - .create = debug_create, - .destroy = debug_destroy, - .populate = debug_populate, - .subsys_id = debug_subsys_id, -}; -- cgit v1.2.2 From 7717f7ba92de485bce8293419a20ffef130f4286 Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Wed, 23 Sep 2009 15:56:22 -0700 Subject: cgroups: add a back-pointer from struct cg_cgroup_link to struct cgroup Currently the cgroups code makes the assumption that the subsystem pointers in a struct css_set uniquely identify the hierarchy->cgroup mappings associated with the css_set; and there's no way to directly identify the associated set of cgroups other than by indirecting through the appropriate subsystem state pointers. This patch removes the need for that assumption by adding a back-pointer from struct cg_cgroup_link object to its associated cgroup; this allows the set of cgroups to be determined by traversing the cg_links list in the struct css_set. Signed-off-by: Paul Menage Reviewed-by: Li Zefan Cc: KAMEZAWA Hiroyuki Cc: Balbir Singh Cc: Dhaval Giani Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 248 +++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 199 insertions(+), 49 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index ccec722213a4..8ba680985335 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -207,6 +207,7 @@ struct cg_cgroup_link { * cgroup, anchored on cgroup->css_sets */ struct list_head cgrp_link_list; + struct cgroup *cgrp; /* * List running through cg_cgroup_links pointing at a * single css_set object, anchored on css_set->cg_links @@ -233,8 +234,11 @@ static int cgroup_subsys_init_idr(struct cgroup_subsys *ss); static DEFINE_RWLOCK(css_set_lock); static int css_set_count; -/* hash table for cgroup groups. This improves the performance to - * find an existing css_set */ +/* + * hash table for cgroup groups. This improves the performance to find + * an existing css_set. This hash doesn't (currently) take into + * account cgroups in empty hierarchies. + */ #define CSS_SET_HASH_BITS 7 #define CSS_SET_TABLE_SIZE (1 << CSS_SET_HASH_BITS) static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE]; @@ -343,6 +347,78 @@ static inline void put_css_set_taskexit(struct css_set *cg) __put_css_set(cg, 1); } +/* + * compare_css_sets - helper function for find_existing_css_set(). + * @cg: candidate css_set being tested + * @old_cg: existing css_set for a task + * @new_cgrp: cgroup that's being entered by the task + * @template: desired set of css pointers in css_set (pre-calculated) + * + * Returns true if "cg" matches "old_cg" except for the hierarchy + * which "new_cgrp" belongs to, for which it should match "new_cgrp". + */ +static bool compare_css_sets(struct css_set *cg, + struct css_set *old_cg, + struct cgroup *new_cgrp, + struct cgroup_subsys_state *template[]) +{ + struct list_head *l1, *l2; + + if (memcmp(template, cg->subsys, sizeof(cg->subsys))) { + /* Not all subsystems matched */ + return false; + } + + /* + * Compare cgroup pointers in order to distinguish between + * different cgroups in heirarchies with no subsystems. We + * could get by with just this check alone (and skip the + * memcmp above) but on most setups the memcmp check will + * avoid the need for this more expensive check on almost all + * candidates. + */ + + l1 = &cg->cg_links; + l2 = &old_cg->cg_links; + while (1) { + struct cg_cgroup_link *cgl1, *cgl2; + struct cgroup *cg1, *cg2; + + l1 = l1->next; + l2 = l2->next; + /* See if we reached the end - both lists are equal length. */ + if (l1 == &cg->cg_links) { + BUG_ON(l2 != &old_cg->cg_links); + break; + } else { + BUG_ON(l2 == &old_cg->cg_links); + } + /* Locate the cgroups associated with these links. */ + cgl1 = list_entry(l1, struct cg_cgroup_link, cg_link_list); + cgl2 = list_entry(l2, struct cg_cgroup_link, cg_link_list); + cg1 = cgl1->cgrp; + cg2 = cgl2->cgrp; + /* Hierarchies should be linked in the same order. */ + BUG_ON(cg1->root != cg2->root); + + /* + * If this hierarchy is the hierarchy of the cgroup + * that's changing, then we need to check that this + * css_set points to the new cgroup; if it's any other + * hierarchy, then this css_set should point to the + * same cgroup as the old css_set. + */ + if (cg1->root == new_cgrp->root) { + if (cg1 != new_cgrp) + return false; + } else { + if (cg1 != cg2) + return false; + } + } + return true; +} + /* * find_existing_css_set() is a helper for * find_css_set(), and checks to see whether an existing @@ -384,10 +460,11 @@ static struct css_set *find_existing_css_set( hhead = css_set_hash(template); hlist_for_each_entry(cg, node, hhead, hlist) { - if (!memcmp(template, cg->subsys, sizeof(cg->subsys))) { - /* All subsystems matched */ - return cg; - } + if (!compare_css_sets(cg, oldcg, cgrp, template)) + continue; + + /* This css_set matches what we need */ + return cg; } /* No existing cgroup group matched */ @@ -441,8 +518,13 @@ static void link_css_set(struct list_head *tmp_cg_links, link = list_first_entry(tmp_cg_links, struct cg_cgroup_link, cgrp_link_list); link->cg = cg; + link->cgrp = cgrp; list_move(&link->cgrp_link_list, &cgrp->css_sets); - list_add(&link->cg_link_list, &cg->cg_links); + /* + * Always add links to the tail of the list so that the list + * is sorted by order of hierarchy creation + */ + list_add_tail(&link->cg_link_list, &cg->cg_links); } /* @@ -462,6 +544,7 @@ static struct css_set *find_css_set( struct list_head tmp_cg_links; struct hlist_head *hhead; + struct cg_cgroup_link *link; /* First see if we already have a cgroup group that matches * the desired set */ @@ -497,18 +580,14 @@ static struct css_set *find_css_set( /* Add reference counts and links from the new css_set. */ for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup *cgrp = res->subsys[i]->cgroup; - struct cgroup_subsys *ss = subsys[i]; atomic_inc(&cgrp->count); - /* - * We want to add a link once per cgroup, so we - * only do it for the first subsystem in each - * hierarchy - */ - if (ss->root->subsys_list.next == &ss->sibling) - link_css_set(&tmp_cg_links, res, cgrp); } - if (list_empty(&rootnode.subsys_list)) - link_css_set(&tmp_cg_links, res, dummytop); + list_for_each_entry(link, &oldcg->cg_links, cg_link_list) { + struct cgroup *c = link->cgrp; + if (c->root == cgrp->root) + c = cgrp; + link_css_set(&tmp_cg_links, res, c); + } BUG_ON(!list_empty(&tmp_cg_links)); @@ -523,6 +602,41 @@ static struct css_set *find_css_set( return res; } +/* + * Return the cgroup for "task" from the given hierarchy. Must be + * called with cgroup_mutex held. + */ +static struct cgroup *task_cgroup_from_root(struct task_struct *task, + struct cgroupfs_root *root) +{ + struct css_set *css; + struct cgroup *res = NULL; + + BUG_ON(!mutex_is_locked(&cgroup_mutex)); + read_lock(&css_set_lock); + /* + * No need to lock the task - since we hold cgroup_mutex the + * task can't change groups, so the only thing that can happen + * is that it exits and its css is set back to init_css_set. + */ + css = task->cgroups; + if (css == &init_css_set) { + res = &root->top_cgroup; + } else { + struct cg_cgroup_link *link; + list_for_each_entry(link, &css->cg_links, cg_link_list) { + struct cgroup *c = link->cgrp; + if (c->root == root) { + res = c; + break; + } + } + } + read_unlock(&css_set_lock); + BUG_ON(!res); + return res; +} + /* * There is one global cgroup mutex. We also require taking * task_lock() when dereferencing a task's cgroup subsys pointers. @@ -1361,27 +1475,6 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen) return 0; } -/* - * Return the first subsystem attached to a cgroup's hierarchy, and - * its subsystem id. - */ - -static void get_first_subsys(const struct cgroup *cgrp, - struct cgroup_subsys_state **css, int *subsys_id) -{ - const struct cgroupfs_root *root = cgrp->root; - const struct cgroup_subsys *test_ss; - BUG_ON(list_empty(&root->subsys_list)); - test_ss = list_entry(root->subsys_list.next, - struct cgroup_subsys, sibling); - if (css) { - *css = cgrp->subsys[test_ss->subsys_id]; - BUG_ON(!*css); - } - if (subsys_id) - *subsys_id = test_ss->subsys_id; -} - /** * cgroup_attach_task - attach task 'tsk' to cgroup 'cgrp' * @cgrp: the cgroup the task is attaching to @@ -1398,12 +1491,9 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) struct css_set *cg; struct css_set *newcg; struct cgroupfs_root *root = cgrp->root; - int subsys_id; - - get_first_subsys(cgrp, NULL, &subsys_id); /* Nothing to do if the task is already in that cgroup */ - oldcgrp = task_cgroup(tsk, subsys_id); + oldcgrp = task_cgroup_from_root(tsk, root); if (cgrp == oldcgrp) return 0; @@ -1961,7 +2051,7 @@ int cgroup_task_count(const struct cgroup *cgrp) * the start of a css_set */ static void cgroup_advance_iter(struct cgroup *cgrp, - struct cgroup_iter *it) + struct cgroup_iter *it) { struct list_head *l = it->cg_link; struct cg_cgroup_link *link; @@ -2964,6 +3054,7 @@ int __init cgroup_init_early(void) init_task.cgroups = &init_css_set; init_css_set_link.cg = &init_css_set; + init_css_set_link.cgrp = dummytop; list_add(&init_css_set_link.cgrp_link_list, &rootnode.top_cgroup.css_sets); list_add(&init_css_set_link.cg_link_list, @@ -3071,7 +3162,6 @@ static int proc_cgroup_show(struct seq_file *m, void *v) for_each_active_root(root) { struct cgroup_subsys *ss; struct cgroup *cgrp; - int subsys_id; int count = 0; seq_printf(m, "%lu:", root->subsys_bits); @@ -3081,8 +3171,7 @@ static int proc_cgroup_show(struct seq_file *m, void *v) seq_printf(m, "%sname=%s", count ? "," : "", root->name); seq_putc(m, ':'); - get_first_subsys(&root->top_cgroup, NULL, &subsys_id); - cgrp = task_cgroup(tsk, subsys_id); + cgrp = task_cgroup_from_root(tsk, root); retval = cgroup_path(cgrp, buf, PAGE_SIZE); if (retval < 0) goto out_unlock; @@ -3408,13 +3497,11 @@ int cgroup_is_descendant(const struct cgroup *cgrp, struct task_struct *task) { int ret; struct cgroup *target; - int subsys_id; if (cgrp == dummytop) return 1; - get_first_subsys(cgrp, NULL, &subsys_id); - target = task_cgroup(task, subsys_id); + target = task_cgroup_from_root(task, cgrp->root); while (cgrp != target && cgrp!= cgrp->top_cgroup) cgrp = cgrp->parent; ret = (cgrp == target); @@ -3824,6 +3911,59 @@ static u64 current_css_set_refcount_read(struct cgroup *cont, return count; } +static int current_css_set_cg_links_read(struct cgroup *cont, + struct cftype *cft, + struct seq_file *seq) +{ + struct cg_cgroup_link *link; + struct css_set *cg; + + read_lock(&css_set_lock); + rcu_read_lock(); + cg = rcu_dereference(current->cgroups); + list_for_each_entry(link, &cg->cg_links, cg_link_list) { + struct cgroup *c = link->cgrp; + const char *name; + + if (c->dentry) + name = c->dentry->d_name.name; + else + name = "?"; + seq_printf(seq, "Root %lu group %s\n", + c->root->subsys_bits, name); + } + rcu_read_unlock(); + read_unlock(&css_set_lock); + return 0; +} + +#define MAX_TASKS_SHOWN_PER_CSS 25 +static int cgroup_css_links_read(struct cgroup *cont, + struct cftype *cft, + struct seq_file *seq) +{ + struct cg_cgroup_link *link; + + read_lock(&css_set_lock); + list_for_each_entry(link, &cont->css_sets, cgrp_link_list) { + struct css_set *cg = link->cg; + struct task_struct *task; + int count = 0; + seq_printf(seq, "css_set %p\n", cg); + list_for_each_entry(task, &cg->tasks, cg_list) { + if (count++ > MAX_TASKS_SHOWN_PER_CSS) { + seq_puts(seq, " ...\n"); + break; + } else { + seq_printf(seq, " task %d\n", + task_pid_vnr(task)); + } + } + } + read_unlock(&css_set_lock); + return 0; +} + static u64 releasable_read(struct cgroup *cgrp, struct cftype *cft) { return test_bit(CGRP_RELEASABLE, &cgrp->flags); @@ -3849,6 +3989,16 @@ static struct cftype debug_files[] = { .read_u64 = current_css_set_refcount_read, }, + { + .name = "current_css_set_cg_links", + .read_seq_string = current_css_set_cg_links_read, + }, + + { + .name = "cgroup_css_links", + .read_seq_string = cgroup_css_links_read, + }, + { .name = "releasable", .read_u64 = releasable_read, -- cgit v1.2.2 From 2c6ab6d200827e1c41dc71fff3a2ac7473f51777 Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Wed, 23 Sep 2009 15:56:23 -0700 Subject: cgroups: allow cgroup hierarchies to be created with no bound subsystems This patch removes the restriction that a cgroup hierarchy must have at least one bound subsystem. The mount option "none" is treated as an explicit request for no bound subsystems. A hierarchy with no subsystems can be useful for plain task tracking, and is also a step towards the support for multiply-bindable subsystems. As part of this change, the hierarchy id is no longer calculated from the bitmask of subsystems in the hierarchy (since this is not guaranteed to be unique) but is allocated via an ida. Reference counts on cgroups from css_set objects are now taken explicitly one per hierarchy, rather than one per subsystem. Example usage: mount -t cgroup -o none,name=foo cgroup /mnt/cgroup Based on the "no-op"/"none" subsystem concept proposed by kamezawa.hiroyu@jp.fujitsu.com Signed-off-by: Paul Menage Reviewed-by: Li Zefan Cc: KAMEZAWA Hiroyuki Cc: Balbir Singh Cc: Dhaval Giani Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 158 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 99 insertions(+), 59 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 8ba680985335..14efffed72c8 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -49,6 +49,7 @@ #include #include #include +#include #include @@ -77,6 +78,9 @@ struct cgroupfs_root { */ unsigned long subsys_bits; + /* Unique id for this hierarchy. */ + int hierarchy_id; + /* The bitmask of subsystems currently attached to this hierarchy */ unsigned long actual_subsys_bits; @@ -147,6 +151,10 @@ struct css_id { static LIST_HEAD(roots); static int root_count; +static DEFINE_IDA(hierarchy_ida); +static int next_hierarchy_id; +static DEFINE_SPINLOCK(hierarchy_id_lock); + /* dummytop is a shorthand for the dummy hierarchy's top cgroup */ #define dummytop (&rootnode.top_cgroup) @@ -264,42 +272,10 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) * compiled into their kernel but not actually in use */ static int use_task_css_set_links __read_mostly; -/* When we create or destroy a css_set, the operation simply - * takes/releases a reference count on all the cgroups referenced - * by subsystems in this css_set. This can end up multiple-counting - * some cgroups, but that's OK - the ref-count is just a - * busy/not-busy indicator; ensuring that we only count each cgroup - * once would require taking a global lock to ensure that no - * subsystems moved between hierarchies while we were doing so. - * - * Possible TODO: decide at boot time based on the number of - * registered subsystems and the number of CPUs or NUMA nodes whether - * it's better for performance to ref-count every subsystem, or to - * take a global lock and only add one ref count to each hierarchy. - */ - -/* - * unlink a css_set from the list and free it - */ -static void unlink_css_set(struct css_set *cg) +static void __put_css_set(struct css_set *cg, int taskexit) { struct cg_cgroup_link *link; struct cg_cgroup_link *saved_link; - - hlist_del(&cg->hlist); - css_set_count--; - - list_for_each_entry_safe(link, saved_link, &cg->cg_links, - cg_link_list) { - list_del(&link->cg_link_list); - list_del(&link->cgrp_link_list); - kfree(link); - } -} - -static void __put_css_set(struct css_set *cg, int taskexit) -{ - int i; /* * Ensure that the refcount doesn't hit zero while any readers * can see it. Similar to atomic_dec_and_lock(), but for an @@ -312,20 +288,27 @@ static void __put_css_set(struct css_set *cg, int taskexit) write_unlock(&css_set_lock); return; } - unlink_css_set(cg); - write_unlock(&css_set_lock); - rcu_read_lock(); - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { - struct cgroup *cgrp = rcu_dereference(cg->subsys[i]->cgroup); + /* This css_set is dead. unlink it and release cgroup refcounts */ + hlist_del(&cg->hlist); + css_set_count--; + + list_for_each_entry_safe(link, saved_link, &cg->cg_links, + cg_link_list) { + struct cgroup *cgrp = link->cgrp; + list_del(&link->cg_link_list); + list_del(&link->cgrp_link_list); if (atomic_dec_and_test(&cgrp->count) && notify_on_release(cgrp)) { if (taskexit) set_bit(CGRP_RELEASABLE, &cgrp->flags); check_for_release(cgrp); } + + kfree(link); } - rcu_read_unlock(); + + write_unlock(&css_set_lock); kfree(cg); } @@ -519,6 +502,7 @@ static void link_css_set(struct list_head *tmp_cg_links, cgrp_link_list); link->cg = cg; link->cgrp = cgrp; + atomic_inc(&cgrp->count); list_move(&link->cgrp_link_list, &cgrp->css_sets); /* * Always add links to the tail of the list so that the list @@ -539,7 +523,6 @@ static struct css_set *find_css_set( { struct css_set *res; struct cgroup_subsys_state *template[CGROUP_SUBSYS_COUNT]; - int i; struct list_head tmp_cg_links; @@ -578,10 +561,6 @@ static struct css_set *find_css_set( write_lock(&css_set_lock); /* Add reference counts and links from the new css_set. */ - for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { - struct cgroup *cgrp = res->subsys[i]->cgroup; - atomic_inc(&cgrp->count); - } list_for_each_entry(link, &oldcg->cg_links, cg_link_list) { struct cgroup *c = link->cgrp; if (c->root == cgrp->root) @@ -972,8 +951,11 @@ struct cgroup_sb_opts { unsigned long flags; char *release_agent; char *name; + /* User explicitly requested empty subsystem */ + bool none; struct cgroupfs_root *new_root; + }; /* Convert a hierarchy specifier into a bitmask of subsystems and @@ -1002,6 +984,9 @@ static int parse_cgroupfs_options(char *data, if (!ss->disabled) opts->subsys_bits |= 1ul << i; } + } else if (!strcmp(token, "none")) { + /* Explicitly have no subsystems */ + opts->none = true; } else if (!strcmp(token, "noprefix")) { set_bit(ROOT_NOPREFIX, &opts->flags); } else if (!strncmp(token, "release_agent=", 14)) { @@ -1051,6 +1036,8 @@ static int parse_cgroupfs_options(char *data, } } + /* Consistency checks */ + /* * Option noprefix was introduced just for backward compatibility * with the old cpuset, so we allow noprefix only if mounting just @@ -1060,7 +1047,15 @@ static int parse_cgroupfs_options(char *data, (opts->subsys_bits & mask)) return -EINVAL; - /* We can't have an empty hierarchy */ + + /* Can't specify "none" and some subsystems */ + if (opts->subsys_bits && opts->none) + return -EINVAL; + + /* + * We either have to specify by name or by subsystems. (So all + * empty hierarchies must have a name). + */ if (!opts->subsys_bits && !opts->name) return -EINVAL; @@ -1141,6 +1136,31 @@ static void init_cgroup_root(struct cgroupfs_root *root) init_cgroup_housekeeping(cgrp); } +static bool init_root_id(struct cgroupfs_root *root) +{ + int ret = 0; + + do { + if (!ida_pre_get(&hierarchy_ida, GFP_KERNEL)) + return false; + spin_lock(&hierarchy_id_lock); + /* Try to allocate the next unused ID */ + ret = ida_get_new_above(&hierarchy_ida, next_hierarchy_id, + &root->hierarchy_id); + if (ret == -ENOSPC) + /* Try again starting from 0 */ + ret = ida_get_new(&hierarchy_ida, &root->hierarchy_id); + if (!ret) { + next_hierarchy_id = root->hierarchy_id + 1; + } else if (ret != -EAGAIN) { + /* Can only get here if the 31-bit IDR is full ... */ + BUG_ON(ret); + } + spin_unlock(&hierarchy_id_lock); + } while (ret); + return true; +} + static int cgroup_test_super(struct super_block *sb, void *data) { struct cgroup_sb_opts *opts = data; @@ -1150,8 +1170,12 @@ static int cgroup_test_super(struct super_block *sb, void *data) if (opts->name && strcmp(opts->name, root->name)) return 0; - /* If we asked for subsystems then they must match */ - if (opts->subsys_bits && (opts->subsys_bits != root->subsys_bits)) + /* + * If we asked for subsystems (or explicitly for no + * subsystems) then they must match + */ + if ((opts->subsys_bits || opts->none) + && (opts->subsys_bits != root->subsys_bits)) return 0; return 1; @@ -1161,15 +1185,19 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) { struct cgroupfs_root *root; - /* Empty hierarchies aren't supported */ - if (!opts->subsys_bits) + if (!opts->subsys_bits && !opts->none) return NULL; root = kzalloc(sizeof(*root), GFP_KERNEL); if (!root) return ERR_PTR(-ENOMEM); + if (!init_root_id(root)) { + kfree(root); + return ERR_PTR(-ENOMEM); + } init_cgroup_root(root); + root->subsys_bits = opts->subsys_bits; root->flags = opts->flags; if (opts->release_agent) @@ -1179,6 +1207,18 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) return root; } +static void cgroup_drop_root(struct cgroupfs_root *root) +{ + if (!root) + return; + + BUG_ON(!root->hierarchy_id); + spin_lock(&hierarchy_id_lock); + ida_remove(&hierarchy_ida, root->hierarchy_id); + spin_unlock(&hierarchy_id_lock); + kfree(root); +} + static int cgroup_set_super(struct super_block *sb, void *data) { int ret; @@ -1188,7 +1228,7 @@ static int cgroup_set_super(struct super_block *sb, void *data) if (!opts->new_root) return -EINVAL; - BUG_ON(!opts->subsys_bits); + BUG_ON(!opts->subsys_bits && !opts->none); ret = set_anon_super(sb, NULL); if (ret) @@ -1257,7 +1297,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type, sb = sget(fs_type, cgroup_test_super, cgroup_set_super, &opts); if (IS_ERR(sb)) { ret = PTR_ERR(sb); - kfree(opts.new_root); + cgroup_drop_root(opts.new_root); goto out_err; } @@ -1351,7 +1391,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type, * We re-used an existing hierarchy - the new root (if * any) is not needed */ - kfree(opts.new_root); + cgroup_drop_root(opts.new_root); } simple_set_mnt(mnt, sb); @@ -1410,7 +1450,7 @@ static void cgroup_kill_sb(struct super_block *sb) { mutex_unlock(&cgroup_mutex); kill_litter_super(sb); - kfree(root); + cgroup_drop_root(root); } static struct file_system_type cgroup_fs_type = { @@ -3109,7 +3149,7 @@ int __init cgroup_init(void) /* Add init_css_set to the hash table */ hhead = css_set_hash(init_css_set.subsys); hlist_add_head(&init_css_set.hlist, hhead); - + BUG_ON(!init_root_id(&rootnode)); err = register_filesystem(&cgroup_fs_type); if (err < 0) goto out; @@ -3164,7 +3204,7 @@ static int proc_cgroup_show(struct seq_file *m, void *v) struct cgroup *cgrp; int count = 0; - seq_printf(m, "%lu:", root->subsys_bits); + seq_printf(m, "%d:", root->hierarchy_id); for_each_subsys(root, ss) seq_printf(m, "%s%s", count++ ? "," : "", ss->name); if (strlen(root->name)) @@ -3210,8 +3250,8 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v) mutex_lock(&cgroup_mutex); for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; - seq_printf(m, "%s\t%lu\t%d\t%d\n", - ss->name, ss->root->subsys_bits, + seq_printf(m, "%s\t%d\t%d\t%d\n", + ss->name, ss->root->hierarchy_id, ss->root->number_of_cgroups, !ss->disabled); } mutex_unlock(&cgroup_mutex); @@ -3929,8 +3969,8 @@ static int current_css_set_cg_links_read(struct cgroup *cont, name = c->dentry->d_name.name; else name = "?"; - seq_printf(seq, "Root %lu group %s\n", - c->root->subsys_bits, name); + seq_printf(seq, "Root %d group %s\n", + c->root->hierarchy_id, name); } rcu_read_unlock(); read_unlock(&css_set_lock); -- cgit v1.2.2 From 8f3ff20862cfcb85500a2bb55ee64622bd59fd0c Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Wed, 23 Sep 2009 15:56:25 -0700 Subject: cgroups: revert "cgroups: fix pid namespace bug" The following series adds a "cgroup.procs" file to each cgroup that reports unique tgids rather than pids, and allows all threads in a threadgroup to be atomically moved to a new cgroup. The subsystem "attach" interface is modified to support attaching whole threadgroups at a time, which could introduce potential problems if any subsystem were to need to access the old cgroup of every thread being moved. The attach interface may need to be revised if this becomes the case. Also added is functionality for read/write locking all CLONE_THREAD fork()ing within a threadgroup, by means of an rwsem that lives in the sighand_struct, for per-threadgroup-ness and also for sharing a cacheline with the sighand's atomic count. This scheme should introduce no extra overhead in the fork path when there's no contention. The final patch reveals potential for a race when forking before a subsystem's attach function is called - one potential solution in case any subsystem has this problem is to hang on to the group's fork mutex through the attach() calls, though no subsystem yet demonstrates need for an extended critical section. This patch: Revert commit 096b7fe012d66ed55e98bc8022405ede0cc80e96 Author: Li Zefan AuthorDate: Wed Jul 29 15:04:04 2009 -0700 Commit: Linus Torvalds CommitDate: Wed Jul 29 19:10:35 2009 -0700 cgroups: fix pid namespace bug This is in preparation for some clashing cgroups changes that subsume the original commit's functionaliy. The original commit fixed a pid namespace bug which Ben Blum fixed independently (in the same way, but with different code) as part of a series of patches. I played around with trying to reconcile Ben's patch series with Li's patch, but concluded that it was simpler to just revert Li's, given that Ben's patch series contained essentially the same fix. Signed-off-by: Paul Menage Cc: Li Zefan Cc: Matt Helsley Cc: "Eric W. Biederman" Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 95 +++++++++++++++------------------------------------------ 1 file changed, 24 insertions(+), 71 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 14efffed72c8..22db0a7cf1fa 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1121,7 +1121,6 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) INIT_LIST_HEAD(&cgrp->children); INIT_LIST_HEAD(&cgrp->css_sets); INIT_LIST_HEAD(&cgrp->release_list); - INIT_LIST_HEAD(&cgrp->pids_list); init_rwsem(&cgrp->pids_mutex); } @@ -2431,30 +2430,12 @@ err: return ret; } -/* - * Cache pids for all threads in the same pid namespace that are - * opening the same "tasks" file. - */ -struct cgroup_pids { - /* The node in cgrp->pids_list */ - struct list_head list; - /* The cgroup those pids belong to */ - struct cgroup *cgrp; - /* The namepsace those pids belong to */ - struct pid_namespace *ns; - /* Array of process ids in the cgroup */ - pid_t *tasks_pids; - /* How many files are using the this tasks_pids array */ - int use_count; - /* Length of the current tasks_pids array */ - int length; -}; - static int cmppid(const void *a, const void *b) { return *(pid_t *)a - *(pid_t *)b; } + /* * seq_file methods for the "tasks" file. The seq_file position is the * next pid to display; the seq_file iterator is a pointer to the pid @@ -2469,47 +2450,45 @@ static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos) * after a seek to the start). Use a binary-search to find the * next pid to display, if any */ - struct cgroup_pids *cp = s->private; - struct cgroup *cgrp = cp->cgrp; + struct cgroup *cgrp = s->private; int index = 0, pid = *pos; int *iter; down_read(&cgrp->pids_mutex); if (pid) { - int end = cp->length; + int end = cgrp->pids_length; while (index < end) { int mid = (index + end) / 2; - if (cp->tasks_pids[mid] == pid) { + if (cgrp->tasks_pids[mid] == pid) { index = mid; break; - } else if (cp->tasks_pids[mid] <= pid) + } else if (cgrp->tasks_pids[mid] <= pid) index = mid + 1; else end = mid; } } /* If we're off the end of the array, we're done */ - if (index >= cp->length) + if (index >= cgrp->pids_length) return NULL; /* Update the abstract position to be the actual pid that we found */ - iter = cp->tasks_pids + index; + iter = cgrp->tasks_pids + index; *pos = *iter; return iter; } static void cgroup_tasks_stop(struct seq_file *s, void *v) { - struct cgroup_pids *cp = s->private; - struct cgroup *cgrp = cp->cgrp; + struct cgroup *cgrp = s->private; up_read(&cgrp->pids_mutex); } static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos) { - struct cgroup_pids *cp = s->private; + struct cgroup *cgrp = s->private; int *p = v; - int *end = cp->tasks_pids + cp->length; + int *end = cgrp->tasks_pids + cgrp->pids_length; /* * Advance to the next pid in the array. If this goes off the @@ -2536,33 +2515,26 @@ static const struct seq_operations cgroup_tasks_seq_operations = { .show = cgroup_tasks_show, }; -static void release_cgroup_pid_array(struct cgroup_pids *cp) +static void release_cgroup_pid_array(struct cgroup *cgrp) { - struct cgroup *cgrp = cp->cgrp; - down_write(&cgrp->pids_mutex); - BUG_ON(!cp->use_count); - if (!--cp->use_count) { - list_del(&cp->list); - put_pid_ns(cp->ns); - kfree(cp->tasks_pids); - kfree(cp); + BUG_ON(!cgrp->pids_use_count); + if (!--cgrp->pids_use_count) { + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = NULL; + cgrp->pids_length = 0; } up_write(&cgrp->pids_mutex); } static int cgroup_tasks_release(struct inode *inode, struct file *file) { - struct seq_file *seq; - struct cgroup_pids *cp; + struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); if (!(file->f_mode & FMODE_READ)) return 0; - seq = file->private_data; - cp = seq->private; - - release_cgroup_pid_array(cp); + release_cgroup_pid_array(cgrp); return seq_release(inode, file); } @@ -2581,8 +2553,6 @@ static struct file_operations cgroup_tasks_operations = { static int cgroup_tasks_open(struct inode *unused, struct file *file) { struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); - struct pid_namespace *ns = current->nsproxy->pid_ns; - struct cgroup_pids *cp; pid_t *pidarray; int npids; int retval; @@ -2609,37 +2579,20 @@ static int cgroup_tasks_open(struct inode *unused, struct file *file) * array if necessary */ down_write(&cgrp->pids_mutex); - - list_for_each_entry(cp, &cgrp->pids_list, list) { - if (ns == cp->ns) - goto found; - } - - cp = kzalloc(sizeof(*cp), GFP_KERNEL); - if (!cp) { - up_write(&cgrp->pids_mutex); - kfree(pidarray); - return -ENOMEM; - } - cp->cgrp = cgrp; - cp->ns = ns; - get_pid_ns(ns); - list_add(&cp->list, &cgrp->pids_list); -found: - kfree(cp->tasks_pids); - cp->tasks_pids = pidarray; - cp->length = npids; - cp->use_count++; + kfree(cgrp->tasks_pids); + cgrp->tasks_pids = pidarray; + cgrp->pids_length = npids; + cgrp->pids_use_count++; up_write(&cgrp->pids_mutex); file->f_op = &cgroup_tasks_operations; retval = seq_open(file, &cgroup_tasks_seq_operations); if (retval) { - release_cgroup_pid_array(cp); + release_cgroup_pid_array(cgrp); return retval; } - ((struct seq_file *)file->private_data)->private = cp; + ((struct seq_file *)file->private_data)->private = cgrp; return 0; } -- cgit v1.2.2 From 102a775e3647628727ae83a9a6abf0564c3ca7cb Mon Sep 17 00:00:00 2001 From: Ben Blum Date: Wed, 23 Sep 2009 15:56:26 -0700 Subject: cgroups: add a read-only "procs" file similar to "tasks" that shows only unique tgids struct cgroup used to have a bunch of fields for keeping track of the pidlist for the tasks file. Those are now separated into a new struct cgroup_pidlist, of which two are had, one for procs and one for tasks. The way the seq_file operations are set up is changed so that just the pidlist struct gets passed around as the private data. Interface example: Suppose a multithreaded process has pid 1000 and other threads with ids 1001, 1002, 1003: $ cat tasks 1000 1001 1002 1003 $ cat cgroup.procs 1000 $ Signed-off-by: Ben Blum Signed-off-by: Paul Menage Acked-by: Li Zefan Cc: Matt Helsley Cc: "Eric W. Biederman" Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 278 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 172 insertions(+), 106 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 22db0a7cf1fa..a9433f50e53d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1121,7 +1121,8 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) INIT_LIST_HEAD(&cgrp->children); INIT_LIST_HEAD(&cgrp->css_sets); INIT_LIST_HEAD(&cgrp->release_list); - init_rwsem(&cgrp->pids_mutex); + init_rwsem(&(cgrp->tasks.mutex)); + init_rwsem(&(cgrp->procs.mutex)); } static void init_cgroup_root(struct cgroupfs_root *root) @@ -1637,15 +1638,6 @@ static int cgroup_tasks_write(struct cgroup *cgrp, struct cftype *cft, u64 pid) return ret; } -/* The various types of files and directories in a cgroup file system */ -enum cgroup_filetype { - FILE_ROOT, - FILE_DIR, - FILE_TASKLIST, - FILE_NOTIFY_ON_RELEASE, - FILE_RELEASE_AGENT, -}; - /** * cgroup_lock_live_group - take cgroup_mutex and check that cgrp is alive. * @cgrp: the cgroup to be checked for liveness @@ -2343,7 +2335,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) } /* - * Stuff for reading the 'tasks' file. + * Stuff for reading the 'tasks'/'procs' files. * * Reading this file can return large amounts of data if a cgroup has * *lots* of attached tasks. So it may need several calls to read(), @@ -2353,27 +2345,106 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) */ /* - * Load into 'pidarray' up to 'npids' of the tasks using cgroup - * 'cgrp'. Return actual number of pids loaded. No need to - * task_lock(p) when reading out p->cgroup, since we're in an RCU - * read section, so the css_set can't go away, and is - * immutable after creation. + * pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries + * If the new stripped list is sufficiently smaller and there's enough memory + * to allocate a new buffer, will let go of the unneeded memory. Returns the + * number of unique elements. */ -static int pid_array_load(pid_t *pidarray, int npids, struct cgroup *cgrp) +/* is the size difference enough that we should re-allocate the array? */ +#define PIDLIST_REALLOC_DIFFERENCE(old, new) ((old) - PAGE_SIZE >= (new)) +static int pidlist_uniq(pid_t **p, int length) { - int n = 0, pid; + int src, dest = 1; + pid_t *list = *p; + pid_t *newlist; + + /* + * we presume the 0th element is unique, so i starts at 1. trivial + * edge cases first; no work needs to be done for either + */ + if (length == 0 || length == 1) + return length; + /* src and dest walk down the list; dest counts unique elements */ + for (src = 1; src < length; src++) { + /* find next unique element */ + while (list[src] == list[src-1]) { + src++; + if (src == length) + goto after; + } + /* dest always points to where the next unique element goes */ + list[dest] = list[src]; + dest++; + } +after: + /* + * if the length difference is large enough, we want to allocate a + * smaller buffer to save memory. if this fails due to out of memory, + * we'll just stay with what we've got. + */ + if (PIDLIST_REALLOC_DIFFERENCE(length, dest)) { + newlist = krealloc(list, dest * sizeof(pid_t), GFP_KERNEL); + if (newlist) + *p = newlist; + } + return dest; +} + +static int cmppid(const void *a, const void *b) +{ + return *(pid_t *)a - *(pid_t *)b; +} + +/* + * Load a cgroup's pidarray with either procs' tgids or tasks' pids + */ +static int pidlist_array_load(struct cgroup *cgrp, bool procs) +{ + pid_t *array; + int length; + int pid, n = 0; /* used for populating the array */ struct cgroup_iter it; struct task_struct *tsk; + struct cgroup_pidlist *l; + + /* + * If cgroup gets more users after we read count, we won't have + * enough space - tough. This race is indistinguishable to the + * caller from the case that the additional cgroup users didn't + * show up until sometime later on. + */ + length = cgroup_task_count(cgrp); + array = kmalloc(length * sizeof(pid_t), GFP_KERNEL); + if (!array) + return -ENOMEM; + /* now, populate the array */ cgroup_iter_start(cgrp, &it); while ((tsk = cgroup_iter_next(cgrp, &it))) { - if (unlikely(n == npids)) + if (unlikely(n == length)) break; - pid = task_pid_vnr(tsk); - if (pid > 0) - pidarray[n++] = pid; + /* get tgid or pid for procs or tasks file respectively */ + pid = (procs ? task_tgid_vnr(tsk) : task_pid_vnr(tsk)); + if (pid > 0) /* make sure to only use valid results */ + array[n++] = pid; } cgroup_iter_end(cgrp, &it); - return n; + length = n; + /* now sort & (if procs) strip out duplicates */ + sort(array, length, sizeof(pid_t), cmppid, NULL); + if (procs) { + length = pidlist_uniq(&array, length); + l = &(cgrp->procs); + } else { + l = &(cgrp->tasks); + } + /* store array in cgroup, freeing old if necessary */ + down_write(&l->mutex); + kfree(l->list); + l->list = array; + l->length = length; + l->use_count++; + up_write(&l->mutex); + return 0; } /** @@ -2430,19 +2501,14 @@ err: return ret; } -static int cmppid(const void *a, const void *b) -{ - return *(pid_t *)a - *(pid_t *)b; -} - /* - * seq_file methods for the "tasks" file. The seq_file position is the + * seq_file methods for the tasks/procs files. The seq_file position is the * next pid to display; the seq_file iterator is a pointer to the pid - * in the cgroup->tasks_pids array. + * in the cgroup->l->list array. */ -static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos) +static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos) { /* * Initially we receive a position value that corresponds to @@ -2450,46 +2516,45 @@ static void *cgroup_tasks_start(struct seq_file *s, loff_t *pos) * after a seek to the start). Use a binary-search to find the * next pid to display, if any */ - struct cgroup *cgrp = s->private; + struct cgroup_pidlist *l = s->private; int index = 0, pid = *pos; int *iter; - down_read(&cgrp->pids_mutex); + down_read(&l->mutex); if (pid) { - int end = cgrp->pids_length; + int end = l->length; while (index < end) { int mid = (index + end) / 2; - if (cgrp->tasks_pids[mid] == pid) { + if (l->list[mid] == pid) { index = mid; break; - } else if (cgrp->tasks_pids[mid] <= pid) + } else if (l->list[mid] <= pid) index = mid + 1; else end = mid; } } /* If we're off the end of the array, we're done */ - if (index >= cgrp->pids_length) + if (index >= l->length) return NULL; /* Update the abstract position to be the actual pid that we found */ - iter = cgrp->tasks_pids + index; + iter = l->list + index; *pos = *iter; return iter; } -static void cgroup_tasks_stop(struct seq_file *s, void *v) +static void cgroup_pidlist_stop(struct seq_file *s, void *v) { - struct cgroup *cgrp = s->private; - up_read(&cgrp->pids_mutex); + struct cgroup_pidlist *l = s->private; + up_read(&l->mutex); } -static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos) +static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos) { - struct cgroup *cgrp = s->private; - int *p = v; - int *end = cgrp->tasks_pids + cgrp->pids_length; - + struct cgroup_pidlist *l = s->private; + pid_t *p = v; + pid_t *end = l->list + l->length; /* * Advance to the next pid in the array. If this goes off the * end, we're done @@ -2503,98 +2568,94 @@ static void *cgroup_tasks_next(struct seq_file *s, void *v, loff_t *pos) } } -static int cgroup_tasks_show(struct seq_file *s, void *v) +static int cgroup_pidlist_show(struct seq_file *s, void *v) { return seq_printf(s, "%d\n", *(int *)v); } -static const struct seq_operations cgroup_tasks_seq_operations = { - .start = cgroup_tasks_start, - .stop = cgroup_tasks_stop, - .next = cgroup_tasks_next, - .show = cgroup_tasks_show, +/* + * seq_operations functions for iterating on pidlists through seq_file - + * independent of whether it's tasks or procs + */ +static const struct seq_operations cgroup_pidlist_seq_operations = { + .start = cgroup_pidlist_start, + .stop = cgroup_pidlist_stop, + .next = cgroup_pidlist_next, + .show = cgroup_pidlist_show, }; -static void release_cgroup_pid_array(struct cgroup *cgrp) +static void cgroup_release_pid_array(struct cgroup_pidlist *l) { - down_write(&cgrp->pids_mutex); - BUG_ON(!cgrp->pids_use_count); - if (!--cgrp->pids_use_count) { - kfree(cgrp->tasks_pids); - cgrp->tasks_pids = NULL; - cgrp->pids_length = 0; + down_write(&l->mutex); + BUG_ON(!l->use_count); + if (!--l->use_count) { + kfree(l->list); + l->list = NULL; + l->length = 0; } - up_write(&cgrp->pids_mutex); + up_write(&l->mutex); } -static int cgroup_tasks_release(struct inode *inode, struct file *file) +static int cgroup_pidlist_release(struct inode *inode, struct file *file) { - struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); - + struct cgroup_pidlist *l; if (!(file->f_mode & FMODE_READ)) return 0; - - release_cgroup_pid_array(cgrp); + /* + * the seq_file will only be initialized if the file was opened for + * reading; hence we check if it's not null only in that case. + */ + l = ((struct seq_file *)file->private_data)->private; + cgroup_release_pid_array(l); return seq_release(inode, file); } -static struct file_operations cgroup_tasks_operations = { +static const struct file_operations cgroup_pidlist_operations = { .read = seq_read, .llseek = seq_lseek, .write = cgroup_file_write, - .release = cgroup_tasks_release, + .release = cgroup_pidlist_release, }; /* - * Handle an open on 'tasks' file. Prepare an array containing the - * process id's of tasks currently attached to the cgroup being opened. + * The following functions handle opens on a file that displays a pidlist + * (tasks or procs). Prepare an array of the process/thread IDs of whoever's + * in the cgroup. */ - -static int cgroup_tasks_open(struct inode *unused, struct file *file) +/* helper function for the two below it */ +static int cgroup_pidlist_open(struct file *file, bool procs) { struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); - pid_t *pidarray; - int npids; + struct cgroup_pidlist *l = (procs ? &cgrp->procs : &cgrp->tasks); int retval; /* Nothing to do for write-only files */ if (!(file->f_mode & FMODE_READ)) return 0; - /* - * If cgroup gets more users after we read count, we won't have - * enough space - tough. This race is indistinguishable to the - * caller from the case that the additional cgroup users didn't - * show up until sometime later on. - */ - npids = cgroup_task_count(cgrp); - pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); - if (!pidarray) - return -ENOMEM; - npids = pid_array_load(pidarray, npids, cgrp); - sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); - - /* - * Store the array in the cgroup, freeing the old - * array if necessary - */ - down_write(&cgrp->pids_mutex); - kfree(cgrp->tasks_pids); - cgrp->tasks_pids = pidarray; - cgrp->pids_length = npids; - cgrp->pids_use_count++; - up_write(&cgrp->pids_mutex); - - file->f_op = &cgroup_tasks_operations; + /* have the array populated */ + retval = pidlist_array_load(cgrp, procs); + if (retval) + return retval; + /* configure file information */ + file->f_op = &cgroup_pidlist_operations; - retval = seq_open(file, &cgroup_tasks_seq_operations); + retval = seq_open(file, &cgroup_pidlist_seq_operations); if (retval) { - release_cgroup_pid_array(cgrp); + cgroup_release_pid_array(l); return retval; } - ((struct seq_file *)file->private_data)->private = cgrp; + ((struct seq_file *)file->private_data)->private = l; return 0; } +static int cgroup_tasks_open(struct inode *unused, struct file *file) +{ + return cgroup_pidlist_open(file, false); +} +static int cgroup_procs_open(struct inode *unused, struct file *file) +{ + return cgroup_pidlist_open(file, true); +} static u64 cgroup_read_notify_on_release(struct cgroup *cgrp, struct cftype *cft) @@ -2617,21 +2678,27 @@ static int cgroup_write_notify_on_release(struct cgroup *cgrp, /* * for the common functions, 'private' gives the type of file */ +/* for hysterical raisins, we can't put this on the older files */ +#define CGROUP_FILE_GENERIC_PREFIX "cgroup." static struct cftype files[] = { { .name = "tasks", .open = cgroup_tasks_open, .write_u64 = cgroup_tasks_write, - .release = cgroup_tasks_release, - .private = FILE_TASKLIST, + .release = cgroup_pidlist_release, .mode = S_IRUGO | S_IWUSR, }, - + { + .name = CGROUP_FILE_GENERIC_PREFIX "procs", + .open = cgroup_procs_open, + /* .write_u64 = cgroup_procs_write, TODO */ + .release = cgroup_pidlist_release, + .mode = S_IRUGO, + }, { .name = "notify_on_release", .read_u64 = cgroup_read_notify_on_release, .write_u64 = cgroup_write_notify_on_release, - .private = FILE_NOTIFY_ON_RELEASE, }, }; @@ -2640,7 +2707,6 @@ static struct cftype cft_release_agent = { .read_seq_string = cgroup_release_agent_show, .write_string = cgroup_release_agent_write, .max_write_len = PATH_MAX, - .private = FILE_RELEASE_AGENT, }; static int cgroup_populate_dir(struct cgroup *cgrp) -- cgit v1.2.2 From 72a8cb30d10d4041c455a7054607a7d519167c87 Mon Sep 17 00:00:00 2001 From: Ben Blum Date: Wed, 23 Sep 2009 15:56:27 -0700 Subject: cgroups: ensure correct concurrent opening/reading of pidlists across pid namespaces Previously there was the problem in which two processes from different pid namespaces reading the tasks or procs file could result in one process seeing results from the other's namespace. Rather than one pidlist for each file in a cgroup, we now keep a list of pidlists keyed by namespace and file type (tasks versus procs) in which entries are placed on demand. Each pidlist has its own lock, and that the pidlists themselves are passed around in the seq_file's private pointer means we don't have to touch the cgroup or its master list except when creating and destroying entries. Signed-off-by: Ben Blum Signed-off-by: Paul Menage Cc: Li Zefan Cc: Matt Helsley Cc: "Eric W. Biederman" Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 90 insertions(+), 17 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a9433f50e53d..97194ba12014 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -776,6 +776,12 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode) */ deactivate_super(cgrp->root->sb); + /* + * if we're getting rid of the cgroup, refcount should ensure + * that there are no pidlists left. + */ + BUG_ON(!list_empty(&cgrp->pidlists)); + call_rcu(&cgrp->rcu_head, free_cgroup_rcu); } iput(inode); @@ -1121,8 +1127,8 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) INIT_LIST_HEAD(&cgrp->children); INIT_LIST_HEAD(&cgrp->css_sets); INIT_LIST_HEAD(&cgrp->release_list); - init_rwsem(&(cgrp->tasks.mutex)); - init_rwsem(&(cgrp->procs.mutex)); + INIT_LIST_HEAD(&cgrp->pidlists); + mutex_init(&cgrp->pidlist_mutex); } static void init_cgroup_root(struct cgroupfs_root *root) @@ -2395,10 +2401,60 @@ static int cmppid(const void *a, const void *b) return *(pid_t *)a - *(pid_t *)b; } +/* + * find the appropriate pidlist for our purpose (given procs vs tasks) + * returns with the lock on that pidlist already held, and takes care + * of the use count, or returns NULL with no locks held if we're out of + * memory. + */ +static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp, + enum cgroup_filetype type) +{ + struct cgroup_pidlist *l; + /* don't need task_nsproxy() if we're looking at ourself */ + struct pid_namespace *ns = get_pid_ns(current->nsproxy->pid_ns); + /* + * We can't drop the pidlist_mutex before taking the l->mutex in case + * the last ref-holder is trying to remove l from the list at the same + * time. Holding the pidlist_mutex precludes somebody taking whichever + * list we find out from under us - compare release_pid_array(). + */ + mutex_lock(&cgrp->pidlist_mutex); + list_for_each_entry(l, &cgrp->pidlists, links) { + if (l->key.type == type && l->key.ns == ns) { + /* found a matching list - drop the extra refcount */ + put_pid_ns(ns); + /* make sure l doesn't vanish out from under us */ + down_write(&l->mutex); + mutex_unlock(&cgrp->pidlist_mutex); + l->use_count++; + return l; + } + } + /* entry not found; create a new one */ + l = kmalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL); + if (!l) { + mutex_unlock(&cgrp->pidlist_mutex); + put_pid_ns(ns); + return l; + } + init_rwsem(&l->mutex); + down_write(&l->mutex); + l->key.type = type; + l->key.ns = ns; + l->use_count = 0; /* don't increment here */ + l->list = NULL; + l->owner = cgrp; + list_add(&l->links, &cgrp->pidlists); + mutex_unlock(&cgrp->pidlist_mutex); + return l; +} + /* * Load a cgroup's pidarray with either procs' tgids or tasks' pids */ -static int pidlist_array_load(struct cgroup *cgrp, bool procs) +static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type, + struct cgroup_pidlist **lp) { pid_t *array; int length; @@ -2423,7 +2479,10 @@ static int pidlist_array_load(struct cgroup *cgrp, bool procs) if (unlikely(n == length)) break; /* get tgid or pid for procs or tasks file respectively */ - pid = (procs ? task_tgid_vnr(tsk) : task_pid_vnr(tsk)); + if (type == CGROUP_FILE_PROCS) + pid = task_tgid_vnr(tsk); + else + pid = task_pid_vnr(tsk); if (pid > 0) /* make sure to only use valid results */ array[n++] = pid; } @@ -2431,19 +2490,20 @@ static int pidlist_array_load(struct cgroup *cgrp, bool procs) length = n; /* now sort & (if procs) strip out duplicates */ sort(array, length, sizeof(pid_t), cmppid, NULL); - if (procs) { + if (type == CGROUP_FILE_PROCS) length = pidlist_uniq(&array, length); - l = &(cgrp->procs); - } else { - l = &(cgrp->tasks); + l = cgroup_pidlist_find(cgrp, type); + if (!l) { + kfree(array); + return -ENOMEM; } - /* store array in cgroup, freeing old if necessary */ - down_write(&l->mutex); + /* store array, freeing old if necessary - lock already held */ kfree(l->list); l->list = array; l->length = length; l->use_count++; up_write(&l->mutex); + *lp = l; return 0; } @@ -2586,13 +2646,26 @@ static const struct seq_operations cgroup_pidlist_seq_operations = { static void cgroup_release_pid_array(struct cgroup_pidlist *l) { + /* + * the case where we're the last user of this particular pidlist will + * have us remove it from the cgroup's list, which entails taking the + * mutex. since in pidlist_find the pidlist->lock depends on cgroup-> + * pidlist_mutex, we have to take pidlist_mutex first. + */ + mutex_lock(&l->owner->pidlist_mutex); down_write(&l->mutex); BUG_ON(!l->use_count); if (!--l->use_count) { + /* we're the last user if refcount is 0; remove and free */ + list_del(&l->links); + mutex_unlock(&l->owner->pidlist_mutex); kfree(l->list); - l->list = NULL; - l->length = 0; + put_pid_ns(l->key.ns); + up_write(&l->mutex); + kfree(l); + return; } + mutex_unlock(&l->owner->pidlist_mutex); up_write(&l->mutex); } @@ -2623,10 +2696,10 @@ static const struct file_operations cgroup_pidlist_operations = { * in the cgroup. */ /* helper function for the two below it */ -static int cgroup_pidlist_open(struct file *file, bool procs) +static int cgroup_pidlist_open(struct file *file, enum cgroup_filetype type) { struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent); - struct cgroup_pidlist *l = (procs ? &cgrp->procs : &cgrp->tasks); + struct cgroup_pidlist *l; int retval; /* Nothing to do for write-only files */ @@ -2634,7 +2707,7 @@ static int cgroup_pidlist_open(struct file *file, bool procs) return 0; /* have the array populated */ - retval = pidlist_array_load(cgrp, procs); + retval = pidlist_array_load(cgrp, type, &l); if (retval) return retval; /* configure file information */ @@ -2650,11 +2723,11 @@ static int cgroup_pidlist_open(struct file *file, bool procs) } static int cgroup_tasks_open(struct inode *unused, struct file *file) { - return cgroup_pidlist_open(file, false); + return cgroup_pidlist_open(file, CGROUP_FILE_TASKS); } static int cgroup_procs_open(struct inode *unused, struct file *file) { - return cgroup_pidlist_open(file, true); + return cgroup_pidlist_open(file, CGROUP_FILE_PROCS); } static u64 cgroup_read_notify_on_release(struct cgroup *cgrp, -- cgit v1.2.2 From d1d9fd3308fdef6b4bf564fa3d6cfe35b68b50bc Mon Sep 17 00:00:00 2001 From: Ben Blum Date: Wed, 23 Sep 2009 15:56:28 -0700 Subject: cgroups: use vmalloc for large cgroups pidlist allocations Separates all pidlist allocation requests to a separate function that judges based on the requested size whether or not the array needs to be vmalloced or can be gotten via kmalloc, and similar for kfree/vfree. Signed-off-by: Ben Blum Signed-off-by: Paul Menage Acked-by: Li Zefan Cc: Matt Helsley Cc: "Eric W. Biederman" Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 97194ba12014..3e356b05b2d5 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -50,6 +50,7 @@ #include #include #include +#include /* TODO: replace with more sophisticated array */ #include @@ -2350,6 +2351,42 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) * */ +/* + * The following two functions "fix" the issue where there are more pids + * than kmalloc will give memory for; in such cases, we use vmalloc/vfree. + * TODO: replace with a kernel-wide solution to this problem + */ +#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2)) +static void *pidlist_allocate(int count) +{ + if (PIDLIST_TOO_LARGE(count)) + return vmalloc(count * sizeof(pid_t)); + else + return kmalloc(count * sizeof(pid_t), GFP_KERNEL); +} +static void pidlist_free(void *p) +{ + if (is_vmalloc_addr(p)) + vfree(p); + else + kfree(p); +} +static void *pidlist_resize(void *p, int newcount) +{ + void *newlist; + /* note: if new alloc fails, old p will still be valid either way */ + if (is_vmalloc_addr(p)) { + newlist = vmalloc(newcount * sizeof(pid_t)); + if (!newlist) + return NULL; + memcpy(newlist, p, newcount * sizeof(pid_t)); + vfree(p); + } else { + newlist = krealloc(p, newcount * sizeof(pid_t), GFP_KERNEL); + } + return newlist; +} + /* * pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries * If the new stripped list is sufficiently smaller and there's enough memory @@ -2389,7 +2426,7 @@ after: * we'll just stay with what we've got. */ if (PIDLIST_REALLOC_DIFFERENCE(length, dest)) { - newlist = krealloc(list, dest * sizeof(pid_t), GFP_KERNEL); + newlist = pidlist_resize(list, dest); if (newlist) *p = newlist; } @@ -2470,7 +2507,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type, * show up until sometime later on. */ length = cgroup_task_count(cgrp); - array = kmalloc(length * sizeof(pid_t), GFP_KERNEL); + array = pidlist_allocate(length); if (!array) return -ENOMEM; /* now, populate the array */ @@ -2494,11 +2531,11 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type, length = pidlist_uniq(&array, length); l = cgroup_pidlist_find(cgrp, type); if (!l) { - kfree(array); + pidlist_free(array); return -ENOMEM; } /* store array, freeing old if necessary - lock already held */ - kfree(l->list); + pidlist_free(l->list); l->list = array; l->length = length; l->use_count++; @@ -2659,7 +2696,7 @@ static void cgroup_release_pid_array(struct cgroup_pidlist *l) /* we're the last user if refcount is 0; remove and free */ list_del(&l->links); mutex_unlock(&l->owner->pidlist_mutex); - kfree(l->list); + pidlist_free(l->list); put_pid_ns(l->key.ns); up_write(&l->mutex); kfree(l); -- cgit v1.2.2 From c378369d8b4fa516ff2b1e79c3eded4e0e955ebb Mon Sep 17 00:00:00 2001 From: Ben Blum Date: Wed, 23 Sep 2009 15:56:29 -0700 Subject: cgroups: change css_set freeing mechanism to be under RCU Changes css_set freeing mechanism to be under RCU This is a prepatch for making the procs file writable. In order to free the old css_sets for each task to be moved as they're being moved, the freeing mechanism must be RCU-protected, or else we would have to have a call to synchronize_rcu() for each task before freeing its old css_set. Signed-off-by: Ben Blum Signed-off-by: Paul Menage Cc: "Paul E. McKenney" Acked-by: Li Zefan Cc: Matt Helsley Cc: "Eric W. Biederman" Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 3e356b05b2d5..bf8dd1a9f2d1 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -267,6 +267,12 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) return &css_set_table[index]; } +static void free_css_set_rcu(struct rcu_head *obj) +{ + struct css_set *cg = container_of(obj, struct css_set, rcu_head); + kfree(cg); +} + /* We don't maintain the lists running through each css_set to its * task until after the first call to cgroup_iter_start(). This * reduces the fork()/exit() overhead for people who have cgroups @@ -310,7 +316,7 @@ static void __put_css_set(struct css_set *cg, int taskexit) } write_unlock(&css_set_lock); - kfree(cg); + call_rcu(&cg->rcu_head, free_css_set_rcu); } /* -- cgit v1.2.2 From be367d09927023d081f9199665c8500f69f14d22 Mon Sep 17 00:00:00 2001 From: Ben Blum Date: Wed, 23 Sep 2009 15:56:31 -0700 Subject: cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time Alter the ss->can_attach and ss->attach functions to be able to deal with a whole threadgroup at a time, for use in cgroup_attach_proc. (This is a pre-patch to cgroup-procs-writable.patch.) Currently, new mode of the attach function can only tell the subsystem about the old cgroup of the threadgroup leader. No subsystem currently needs that information for each thread that's being moved, but if one were to be added (for example, one that counts tasks within a group) this bit would need to be reworked a bit to tell the subsystem the right information. [hidave.darkstar@gmail.com: fix build] Signed-off-by: Ben Blum Signed-off-by: Paul Menage Acked-by: Li Zefan Reviewed-by: Matt Helsley Cc: "Eric W. Biederman" Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Dave Young Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 4 +-- kernel/cgroup_freezer.c | 15 ++++++++++- kernel/cpuset.c | 66 ++++++++++++++++++++++++++++++++++++++----------- kernel/ns_cgroup.c | 16 ++++++++++-- kernel/sched.c | 35 +++++++++++++++++++++++--- 5 files changed, 114 insertions(+), 22 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index bf8dd1a9f2d1..7ccba4bc5e3b 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1552,7 +1552,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) for_each_subsys(root, ss) { if (ss->can_attach) { - retval = ss->can_attach(ss, cgrp, tsk); + retval = ss->can_attach(ss, cgrp, tsk, false); if (retval) return retval; } @@ -1590,7 +1590,7 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) for_each_subsys(root, ss) { if (ss->attach) - ss->attach(ss, cgrp, oldcgrp, tsk); + ss->attach(ss, cgrp, oldcgrp, tsk, false); } set_bit(CGRP_RELEASABLE, &oldcgrp->flags); synchronize_rcu(); diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index fb249e2bcada..59e9ef6aab40 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -159,7 +159,7 @@ static bool is_task_frozen_enough(struct task_struct *task) */ static int freezer_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup, - struct task_struct *task) + struct task_struct *task, bool threadgroup) { struct freezer *freezer; @@ -177,6 +177,19 @@ static int freezer_can_attach(struct cgroup_subsys *ss, if (freezer->state == CGROUP_FROZEN) return -EBUSY; + if (threadgroup) { + struct task_struct *c; + + rcu_read_lock(); + list_for_each_entry_rcu(c, &task->thread_group, thread_group) { + if (is_task_frozen_enough(c)) { + rcu_read_unlock(); + return -EBUSY; + } + } + rcu_read_unlock(); + } + return 0; } diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 7e75a41bd508..b5cb469d2545 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1324,9 +1324,10 @@ static int fmeter_getrate(struct fmeter *fmp) static cpumask_var_t cpus_attach; /* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */ -static int cpuset_can_attach(struct cgroup_subsys *ss, - struct cgroup *cont, struct task_struct *tsk) +static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont, + struct task_struct *tsk, bool threadgroup) { + int ret; struct cpuset *cs = cgroup_cs(cont); if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) @@ -1343,18 +1344,51 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, if (tsk->flags & PF_THREAD_BOUND) return -EINVAL; - return security_task_setscheduler(tsk, 0, NULL); + ret = security_task_setscheduler(tsk, 0, NULL); + if (ret) + return ret; + if (threadgroup) { + struct task_struct *c; + + rcu_read_lock(); + list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { + ret = security_task_setscheduler(c, 0, NULL); + if (ret) { + rcu_read_unlock(); + return ret; + } + } + rcu_read_unlock(); + } + return 0; +} + +static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to, + struct cpuset *cs) +{ + int err; + /* + * can_attach beforehand should guarantee that this doesn't fail. + * TODO: have a better way to handle failure here + */ + err = set_cpus_allowed_ptr(tsk, cpus_attach); + WARN_ON_ONCE(err); + + task_lock(tsk); + cpuset_change_task_nodemask(tsk, to); + task_unlock(tsk); + cpuset_update_task_spread_flag(cs, tsk); + } -static void cpuset_attach(struct cgroup_subsys *ss, - struct cgroup *cont, struct cgroup *oldcont, - struct task_struct *tsk) +static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont, + struct cgroup *oldcont, struct task_struct *tsk, + bool threadgroup) { nodemask_t from, to; struct mm_struct *mm; struct cpuset *cs = cgroup_cs(cont); struct cpuset *oldcs = cgroup_cs(oldcont); - int err; if (cs == &top_cpuset) { cpumask_copy(cpus_attach, cpu_possible_mask); @@ -1363,15 +1397,19 @@ static void cpuset_attach(struct cgroup_subsys *ss, guarantee_online_cpus(cs, cpus_attach); guarantee_online_mems(cs, &to); } - err = set_cpus_allowed_ptr(tsk, cpus_attach); - if (err) - return; - task_lock(tsk); - cpuset_change_task_nodemask(tsk, &to); - task_unlock(tsk); - cpuset_update_task_spread_flag(cs, tsk); + /* do per-task migration stuff possibly for each in the threadgroup */ + cpuset_attach_task(tsk, &to, cs); + if (threadgroup) { + struct task_struct *c; + rcu_read_lock(); + list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { + cpuset_attach_task(c, &to, cs); + } + rcu_read_unlock(); + } + /* change mm; only needs to be done once even if threadgroup */ from = oldcs->mems_allowed; to = cs->mems_allowed; mm = get_task_mm(tsk); diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c index 5aa854f9e5ae..2a5dfec8efe0 100644 --- a/kernel/ns_cgroup.c +++ b/kernel/ns_cgroup.c @@ -42,8 +42,8 @@ int ns_cgroup_clone(struct task_struct *task, struct pid *pid) * (hence either you are in the same cgroup as task, or in an * ancestor cgroup thereof) */ -static int ns_can_attach(struct cgroup_subsys *ss, - struct cgroup *new_cgroup, struct task_struct *task) +static int ns_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup, + struct task_struct *task, bool threadgroup) { if (current != task) { if (!capable(CAP_SYS_ADMIN)) @@ -56,6 +56,18 @@ static int ns_can_attach(struct cgroup_subsys *ss, if (!cgroup_is_descendant(new_cgroup, task)) return -EPERM; + if (threadgroup) { + struct task_struct *c; + rcu_read_lock(); + list_for_each_entry_rcu(c, &task->thread_group, thread_group) { + if (!cgroup_is_descendant(new_cgroup, c)) { + rcu_read_unlock(); + return -EPERM; + } + } + rcu_read_unlock(); + } + return 0; } diff --git a/kernel/sched.c b/kernel/sched.c index 2f76e06bea58..0d0361b9dbb3 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -10377,8 +10377,7 @@ cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) } static int -cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct task_struct *tsk) +cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { #ifdef CONFIG_RT_GROUP_SCHED if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) @@ -10388,15 +10387,45 @@ cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, if (tsk->sched_class != &fair_sched_class) return -EINVAL; #endif + return 0; +} +static int +cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, + struct task_struct *tsk, bool threadgroup) +{ + int retval = cpu_cgroup_can_attach_task(cgrp, tsk); + if (retval) + return retval; + if (threadgroup) { + struct task_struct *c; + rcu_read_lock(); + list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { + retval = cpu_cgroup_can_attach_task(cgrp, c); + if (retval) { + rcu_read_unlock(); + return retval; + } + } + rcu_read_unlock(); + } return 0; } static void cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, - struct cgroup *old_cont, struct task_struct *tsk) + struct cgroup *old_cont, struct task_struct *tsk, + bool threadgroup) { sched_move_task(tsk); + if (threadgroup) { + struct task_struct *c; + rcu_read_lock(); + list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { + sched_move_task(c); + } + rcu_read_unlock(); + } } #ifdef CONFIG_FAIR_GROUP_SCHED -- cgit v1.2.2 From 296c81d89f4f14269f7346f81442910158c0a83a Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Wed, 23 Sep 2009 15:56:36 -0700 Subject: memory controller: soft limit interface Add an interface to allow get/set of soft limits. Soft limits for memory plus swap controller (memsw) is currently not supported. Resource counters have been enhanced to support soft limits and new type RES_SOFT_LIMIT has been added. Unlike hard limits, soft limits can be directly set and do not need any reclaim or checks before setting them to a newer value. Kamezawa-San raised a question as to whether soft limit should belong to res_counter. Since all resources understand the basic concepts of hard and soft limits, it is justified to add soft limits here. Soft limits are a generic resource usage feature, even file system quotas support soft limits. Signed-off-by: Balbir Singh Cc: KAMEZAWA Hiroyuki Cc: Li Zefan Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/res_counter.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/res_counter.c b/kernel/res_counter.c index e1338f074314..bcdabf37c40b 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -19,6 +19,7 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent) { spin_lock_init(&counter->lock); counter->limit = RESOURCE_MAX; + counter->soft_limit = RESOURCE_MAX; counter->parent = parent; } @@ -101,6 +102,8 @@ res_counter_member(struct res_counter *counter, int member) return &counter->limit; case RES_FAILCNT: return &counter->failcnt; + case RES_SOFT_LIMIT: + return &counter->soft_limit; }; BUG(); -- cgit v1.2.2 From f64c3f54940d6929a2b6dcffaab942bd62be2e66 Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Wed, 23 Sep 2009 15:56:37 -0700 Subject: memory controller: soft limit organize cgroups Organize cgroups over soft limit in a RB-Tree Introduce an RB-Tree for storing memory cgroups that are over their soft limit. The overall goal is to 1. Add a memory cgroup to the RB-Tree when the soft limit is exceeded. We are careful about updates, updates take place only after a particular time interval has passed 2. We remove the node from the RB-Tree when the usage goes below the soft limit The next set of patches will exploit the RB-Tree to get the group that is over its soft limit by the largest amount and reclaim from it, when we face memory contention. [hugh.dickins@tiscali.co.uk: CONFIG_CGROUP_MEM_RES_CTLR=y CONFIG_PREEMPT=y fails to boot] Signed-off-by: Balbir Singh Signed-off-by: KAMEZAWA Hiroyuki Cc: Li Zefan Cc: KOSAKI Motohiro Signed-off-by: Hugh Dickins Cc: Jiri Slaby Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/res_counter.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/res_counter.c b/kernel/res_counter.c index bcdabf37c40b..88faec23e833 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -37,17 +37,27 @@ int res_counter_charge_locked(struct res_counter *counter, unsigned long val) } int res_counter_charge(struct res_counter *counter, unsigned long val, - struct res_counter **limit_fail_at) + struct res_counter **limit_fail_at, + struct res_counter **soft_limit_fail_at) { int ret; unsigned long flags; struct res_counter *c, *u; *limit_fail_at = NULL; + if (soft_limit_fail_at) + *soft_limit_fail_at = NULL; local_irq_save(flags); for (c = counter; c != NULL; c = c->parent) { spin_lock(&c->lock); ret = res_counter_charge_locked(c, val); + /* + * With soft limits, we return the highest ancestor + * that exceeds its soft limit + */ + if (soft_limit_fail_at && + !res_counter_soft_limit_check_locked(c)) + *soft_limit_fail_at = c; spin_unlock(&c->lock); if (ret < 0) { *limit_fail_at = c; @@ -75,7 +85,8 @@ void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val) counter->usage -= val; } -void res_counter_uncharge(struct res_counter *counter, unsigned long val) +void res_counter_uncharge(struct res_counter *counter, unsigned long val, + bool *was_soft_limit_excess) { unsigned long flags; struct res_counter *c; @@ -83,6 +94,9 @@ void res_counter_uncharge(struct res_counter *counter, unsigned long val) local_irq_save(flags); for (c = counter; c != NULL; c = c->parent) { spin_lock(&c->lock); + if (was_soft_limit_excess) + *was_soft_limit_excess = + !res_counter_soft_limit_check_locked(c); res_counter_uncharge_locked(c, val); spin_unlock(&c->lock); } -- cgit v1.2.2 From a7f0765edfd53aed09cb7b0e15863688b39447de Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:56:44 -0700 Subject: ptrace: __ptrace_detach: do __wake_up_parent() if we reap the tracee The bug is old, it wasn't cause by recent changes. Test case: static void *tfunc(void *arg) { int pid = (long)arg; assert(ptrace(PTRACE_ATTACH, pid, NULL, NULL) == 0); kill(pid, SIGKILL); sleep(1); return NULL; } int main(void) { pthread_t th; long pid = fork(); if (!pid) pause(); signal(SIGCHLD, SIG_IGN); assert(pthread_create(&th, NULL, tfunc, (void*)pid) == 0); int r = waitpid(-1, NULL, __WNOTHREAD); printf("waitpid: %d %m\n", r); return 0; } Before the patch this program hangs, after this patch waitpid() correctly fails with errno == -ECHILD. The problem is, __ptrace_detach() reaps the EXIT_ZOMBIE tracee if its ->real_parent is our sub-thread and we ignore SIGCHLD. But in this case we should wake up other threads which can sleep in do_wait(). Signed-off-by: Oleg Nesterov Cc: Roland McGrath Cc: Vitaly Mayatskikh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 5 +++++ kernel/ptrace.c | 11 +++++++---- kernel/signal.c | 9 --------- 3 files changed, 12 insertions(+), 13 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 60d6fdcc9265..782b2e1f7ca2 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1575,6 +1575,11 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk) return 0; } +void __wake_up_parent(struct task_struct *p, struct task_struct *parent) +{ + wake_up_interruptible_sync(&parent->signal->wait_chldexit); +} + static long do_wait(struct wait_opts *wo) { DECLARE_WAITQUEUE(wait, current); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 307c285af59e..23bd09cd042e 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -266,9 +266,10 @@ static int ignoring_children(struct sighand_struct *sigh) * or self-reaping. Do notification now if it would have happened earlier. * If it should reap itself, return true. * - * If it's our own child, there is no notification to do. - * But if our normal children self-reap, then this child - * was prevented by ptrace and we must reap it now. + * If it's our own child, there is no notification to do. But if our normal + * children self-reap, then this child was prevented by ptrace and we must + * reap it now, in that case we must also wake up sub-threads sleeping in + * do_wait(). */ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) { @@ -278,8 +279,10 @@ static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p) if (!task_detached(p) && thread_group_empty(p)) { if (!same_thread_group(p->real_parent, tracer)) do_notify_parent(p, p->exit_signal); - else if (ignoring_children(tracer->sighand)) + else if (ignoring_children(tracer->sighand)) { + __wake_up_parent(p, tracer); p->exit_signal = -1; + } } if (task_detached(p)) { /* Mark it as in the process of being reaped. */ diff --git a/kernel/signal.c b/kernel/signal.c index 64c5deeaca5d..534ea81cde47 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1382,15 +1382,6 @@ ret: return ret; } -/* - * Wake up any threads in the parent blocked in wait* syscalls. - */ -static inline void __wake_up_parent(struct task_struct *p, - struct task_struct *parent) -{ - wake_up_interruptible_sync(&parent->signal->wait_chldexit); -} - /* * Let a parent know about the death of a child. * For a stopped/continued status change, use do_notify_parent_cldstop instead. -- cgit v1.2.2 From a2322e1d272938d192d8c24cdacf57c0c7a2683f Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:56:45 -0700 Subject: do_wait() wakeup optimization: shift security_task_wait() from eligible_child() to wait_consider_task() Preparation, no functional changes. eligible_child() has a single caller, wait_consider_task(). We can move security_task_wait() out from eligible_child(), this allows us to use it for filtered wake_up(). Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Cc: Ingo Molnar Cc: Ratan Nalumasu Cc: Vitaly Mayatskikh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 782b2e1f7ca2..ef2dfa818bf1 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1112,8 +1112,6 @@ static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) static int eligible_child(struct wait_opts *wo, struct task_struct *p) { - int err; - if (wo->wo_type < PIDTYPE_MAX) { if (task_pid_type(p, wo->wo_type) != wo->wo_pid) return 0; @@ -1128,10 +1126,6 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p) && !(wo->wo_flags & __WALL)) return 0; - err = security_task_wait(p); - if (err) - return err; - return 1; } @@ -1492,6 +1486,7 @@ static int wait_consider_task(struct wait_opts *wo, struct task_struct *parent, if (!ret) return ret; + ret = security_task_wait(p); if (unlikely(ret < 0)) { /* * If we have not yet seen any eligible child, -- cgit v1.2.2 From 0b7570e77f7c3abd43107dabc47ea89daf9a1cba Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:56:46 -0700 Subject: do_wait() wakeup optimization: change __wake_up_parent() to use filtered wakeup Ratan Nalumasu reported that in a process with many threads doing unnecessary wakeups. Every waiting thread in the process wakes up to loop through the children and see that the only ones it cares about are still not ready. Now that we have struct wait_opts we can change do_wait/__wake_up_parent to use filtered wakeups. We can make child_wait_callback() more clever later, right now it only checks eligible_child(). Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Cc: Ingo Molnar Cc: Ratan Nalumasu Cc: Vitaly Mayatskikh Acked-by: James Morris Tested-by: Valdis Kletnieks Acked-by: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index ef2dfa818bf1..7838b4d68774 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1097,6 +1097,7 @@ struct wait_opts { int __user *wo_stat; struct rusage __user *wo_rusage; + wait_queue_t child_wait; int notask_error; }; @@ -1570,20 +1571,35 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk) return 0; } +static int child_wait_callback(wait_queue_t *wait, unsigned mode, + int sync, void *key) +{ + struct wait_opts *wo = container_of(wait, struct wait_opts, + child_wait); + struct task_struct *p = key; + + if (!eligible_child(wo, p)) + return 0; + + return default_wake_function(wait, mode, sync, key); +} + void __wake_up_parent(struct task_struct *p, struct task_struct *parent) { - wake_up_interruptible_sync(&parent->signal->wait_chldexit); + __wake_up_sync_key(&parent->signal->wait_chldexit, + TASK_INTERRUPTIBLE, 1, p); } static long do_wait(struct wait_opts *wo) { - DECLARE_WAITQUEUE(wait, current); struct task_struct *tsk; int retval; trace_sched_process_wait(wo->wo_pid); - add_wait_queue(¤t->signal->wait_chldexit,&wait); + init_waitqueue_func_entry(&wo->child_wait, child_wait_callback); + wo->child_wait.private = current; + add_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait); repeat: /* * If there is nothing that can match our critiera just get out. @@ -1624,7 +1640,8 @@ notask: } end: __set_current_state(TASK_RUNNING); - remove_wait_queue(¤t->signal->wait_chldexit,&wait); + remove_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait); + if (wo->wo_info) { struct siginfo __user *infop = wo->wo_info; -- cgit v1.2.2 From b4fe51823d797d6959b2eee7868023e61606daa9 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:56:47 -0700 Subject: do_wait() wakeup optimization: child_wait_callback: check __WNOTHREAD case Suggested by Roland. do_wait(__WNOTHREAD) can only succeed if the caller is either ptracer, or it is ->real_parent and the child is not traced. IOW, caller == p->parent otherwise we should not wake up. Change child_wait_callback() to check this. Ratan reports the workload with CPU load >99% caused by unnecessary wakeups, should be fixed by this patch. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Cc: Ingo Molnar Cc: Ratan Nalumasu Cc: Vitaly Mayatskikh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 7838b4d68774..270a68b7f22f 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1581,6 +1581,9 @@ static int child_wait_callback(wait_queue_t *wait, unsigned mode, if (!eligible_child(wo, p)) return 0; + if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent) + return 0; + return default_wake_function(wait, mode, sync, key); } -- cgit v1.2.2 From 5c01ba49e6647d86bc7576105f82027200d1f303 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:56:48 -0700 Subject: do_wait-wakeup-optimization: fix child_wait_callback()->eligible_child() usage child_wait_callback()->eligible_child() is not right, we can miss the wakeup if the task was detached before __wake_up_parent() and the caller of do_wait() didn't use __WALL. Move ->wo_pid checks from eligible_child() to the new helper, eligible_pid(), and change child_wait_callback() to use it instead of eligible_child(). Note: actually I think it would be better to fix the __WCLONE check in eligible_child(), it doesn't look exactly right. But it is not clear what is the supposed behaviour, and any change is user-visible. Reported-by: KAMEZAWA Hiroyuki Tested-by: KAMEZAWA Hiroyuki Signed-off-by: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 270a68b7f22f..3fb9a77863d5 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1111,13 +1111,16 @@ static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) return pid; } -static int eligible_child(struct wait_opts *wo, struct task_struct *p) +static inline int eligible_pid(struct wait_opts *wo, struct task_struct *p) { - if (wo->wo_type < PIDTYPE_MAX) { - if (task_pid_type(p, wo->wo_type) != wo->wo_pid) - return 0; - } + return wo->wo_type == PIDTYPE_MAX || + task_pid_type(p, wo->wo_type) == wo->wo_pid; +} +static int eligible_child(struct wait_opts *wo, struct task_struct *p) +{ + if (!eligible_pid(wo, p)) + return 0; /* Wait for all children (clone and not) if __WALL is set; * otherwise, wait for clone children *only* if __WCLONE is * set; otherwise, wait for non-clone children *only*. (Note: @@ -1578,7 +1581,7 @@ static int child_wait_callback(wait_queue_t *wait, unsigned mode, child_wait); struct task_struct *p = key; - if (!eligible_child(wo, p)) + if (!eligible_pid(wo, p)) return 0; if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent) -- cgit v1.2.2 From 989264f4645c183331a1279d513f4b1ddc06e1f5 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:56:49 -0700 Subject: do_wait-wakeup-optimization: simplify task_pid_type() task_pid_type() is only used by eligible_pid() which has to check wo_type != PIDTYPE_MAX anyway. Remove this check from task_pid_type() and factor out ->pids[type] access, this shrinks .text a bit and simplifies the code. The matches the behaviour of other similar helpers, say get_task_pid(). The caller must ensure that pid_type is valid, not the callee. Signed-off-by: Oleg Nesterov Cc: Roland McGrath Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 3fb9a77863d5..650c1d1a55d0 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1101,17 +1101,15 @@ struct wait_opts { int notask_error; }; -static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) +static inline +struct pid *task_pid_type(struct task_struct *task, enum pid_type type) { - struct pid *pid = NULL; - if (type == PIDTYPE_PID) - pid = task->pids[type].pid; - else if (type < PIDTYPE_MAX) - pid = task->group_leader->pids[type].pid; - return pid; + if (type != PIDTYPE_PID) + task = task->group_leader; + return task->pids[type].pid; } -static inline int eligible_pid(struct wait_opts *wo, struct task_struct *p) +static int eligible_pid(struct wait_opts *wo, struct task_struct *p) { return wo->wo_type == PIDTYPE_MAX || task_pid_type(p, wo->wo_type) == wo->wo_pid; -- cgit v1.2.2 From b6e763f07fba6243d2a553ed9a4f3e10a789932a Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:56:50 -0700 Subject: wait_consider_task: kill "parent" argument Kill the unused "parent" argument in wait_consider_task(), it was never used. Signed-off-by: Oleg Nesterov Cc: Roland McGrath Cc: Ingo Molnar Cc: Ratan Nalumasu Cc: Vitaly Mayatskikh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 650c1d1a55d0..1daa7f46bccd 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1481,8 +1481,8 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p) * then ->notask_error is 0 if @p is an eligible child, * or another error from security_task_wait(), or still -ECHILD. */ -static int wait_consider_task(struct wait_opts *wo, struct task_struct *parent, - int ptrace, struct task_struct *p) +static int wait_consider_task(struct wait_opts *wo, int ptrace, + struct task_struct *p) { int ret = eligible_child(wo, p); if (!ret) @@ -1550,7 +1550,7 @@ static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk) * Do not consider detached threads. */ if (!task_detached(p)) { - int ret = wait_consider_task(wo, tsk, 0, p); + int ret = wait_consider_task(wo, 0, p); if (ret) return ret; } @@ -1564,7 +1564,7 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk) struct task_struct *p; list_for_each_entry(p, &tsk->ptraced, ptrace_entry) { - int ret = wait_consider_task(wo, tsk, 1, p); + int ret = wait_consider_task(wo, 1, p); if (ret) return ret; } -- cgit v1.2.2 From dfe16dfa4ac178d9a10b489a73d535c6976e48d2 Mon Sep 17 00:00:00 2001 From: Vitaly Mayatskikh Date: Wed, 23 Sep 2009 15:56:51 -0700 Subject: do_wait: fix sys_waitid()-specific behaviour do_wait() checks ->wo_info to figure out who is the caller. If it's not NULL the caller should be sys_waitid(), in that case do_wait() fixes up the retval or zeros ->wo_info, depending on retval from underlying function. This is bug: user can pass ->wo_info == NULL and sys_waitid() will return incorrect value. man 2 waitid says: waitid(): returns 0 on success Test-case: int main(void) { if (fork()) assert(waitid(P_ALL, 0, NULL, WEXITED) == 0); return 0; } Result: Assertion `waitid(P_ALL, 0, ((void *)0), 4) == 0' failed. Move that code to sys_waitid(). User-visible change: sys_waitid() will return 0 on success, either infop is set or not. Note, there's another bug in wait_noreap_copyout() which affects return value of sys_waitid(). It will be fixed in next patch. Signed-off-by: Vitaly Mayatskikh Reviewed-by: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 49 +++++++++++++++++++++++-------------------------- 1 file changed, 23 insertions(+), 26 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 1daa7f46bccd..2cc69eb8db2a 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1645,32 +1645,6 @@ notask: end: __set_current_state(TASK_RUNNING); remove_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait); - - if (wo->wo_info) { - struct siginfo __user *infop = wo->wo_info; - - if (retval > 0) - retval = 0; - else { - /* - * For a WNOHANG return, clear out all the fields - * we would set so the user can easily tell the - * difference. - */ - if (!retval) - retval = put_user(0, &infop->si_signo); - if (!retval) - retval = put_user(0, &infop->si_errno); - if (!retval) - retval = put_user(0, &infop->si_code); - if (!retval) - retval = put_user(0, &infop->si_pid); - if (!retval) - retval = put_user(0, &infop->si_uid); - if (!retval) - retval = put_user(0, &infop->si_status); - } - } return retval; } @@ -1715,6 +1689,29 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, wo.wo_stat = NULL; wo.wo_rusage = ru; ret = do_wait(&wo); + + if (ret > 0) { + ret = 0; + } else if (infop) { + /* + * For a WNOHANG return, clear out all the fields + * we would set so the user can easily tell the + * difference. + */ + if (!ret) + ret = put_user(0, &infop->si_signo); + if (!ret) + ret = put_user(0, &infop->si_errno); + if (!ret) + ret = put_user(0, &infop->si_code); + if (!ret) + ret = put_user(0, &infop->si_pid); + if (!ret) + ret = put_user(0, &infop->si_uid); + if (!ret) + ret = put_user(0, &infop->si_status); + } + put_pid(pid); /* avoid REGPARM breakage on x86: */ -- cgit v1.2.2 From b6fe2d117e98805ee76352e6468f87d494a97292 Mon Sep 17 00:00:00 2001 From: Vitaly Mayatskikh Date: Wed, 23 Sep 2009 15:56:52 -0700 Subject: wait_noreap_copyout(): check for ->wo_info != NULL Current behaviour of sys_waitid() looks odd. If user passes infop == NULL, sys_waitid() returns success. When user additionally specifies flag WNOWAIT, sys_waitid() returns -EFAULT on the same conditions. When user combines WNOWAIT with WCONTINUED, sys_waitid() again returns success. This patch adds check for ->wo_info in wait_noreap_copyout(). User-visible change: starting from this commit, sys_waitid() always checks infop != NULL and does not fail if it is NULL. Signed-off-by: Vitaly Mayatskikh Reviewed-by: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 2cc69eb8db2a..6c75ff83a8fe 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1140,18 +1140,20 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p, put_task_struct(p); infop = wo->wo_info; - if (!retval) - retval = put_user(SIGCHLD, &infop->si_signo); - if (!retval) - retval = put_user(0, &infop->si_errno); - if (!retval) - retval = put_user((short)why, &infop->si_code); - if (!retval) - retval = put_user(pid, &infop->si_pid); - if (!retval) - retval = put_user(uid, &infop->si_uid); - if (!retval) - retval = put_user(status, &infop->si_status); + if (infop) { + if (!retval) + retval = put_user(SIGCHLD, &infop->si_signo); + if (!retval) + retval = put_user(0, &infop->si_errno); + if (!retval) + retval = put_user((short)why, &infop->si_code); + if (!retval) + retval = put_user(pid, &infop->si_pid); + if (!retval) + retval = put_user(uid, &infop->si_uid); + if (!retval) + retval = put_user(status, &infop->si_status); + } if (!retval) retval = pid; return retval; -- cgit v1.2.2 From ae6d2ed7bb3877ff35b9569402025f40ea2e1803 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 23 Sep 2009 15:56:53 -0700 Subject: signals: tracehook_notify_jctl change This changes tracehook_notify_jctl() so it's called with the siglock held, and changes its argument and return value definition. These clean-ups make it a better fit for what new tracing hooks need to check. Tracing needs the siglock here, held from the time TASK_STOPPED was set, to avoid potential SIGCONT races if it wants to allow any blocking in its tracing hooks. This also folds the finish_stop() function into its caller do_signal_stop(). The function is short, called only once and only unconditionally. It aids readability to fold it in. [oleg@redhat.com: do not call tracehook_notify_jctl() in TASK_STOPPED state] [oleg@redhat.com: introduce tracehook_finish_jctl() helper] Signed-off-by: Roland McGrath Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 97 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 47 insertions(+), 50 deletions(-) (limited to 'kernel') diff --git a/kernel/signal.c b/kernel/signal.c index 534ea81cde47..5d3b3f8f219b 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -705,7 +705,7 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) if (why) { /* - * The first thread which returns from finish_stop() + * The first thread which returns from do_signal_stop() * will take ->siglock, notice SIGNAL_CLD_MASK, and * notify its parent. See get_signal_to_deliver(). */ @@ -1664,29 +1664,6 @@ void ptrace_notify(int exit_code) spin_unlock_irq(¤t->sighand->siglock); } -static void -finish_stop(int stop_count) -{ - /* - * If there are no other threads in the group, or if there is - * a group stop in progress and we are the last to stop, - * report to the parent. When ptraced, every thread reports itself. - */ - if (tracehook_notify_jctl(stop_count == 0, CLD_STOPPED)) { - read_lock(&tasklist_lock); - do_notify_parent_cldstop(current, CLD_STOPPED); - read_unlock(&tasklist_lock); - } - - do { - schedule(); - } while (try_to_freeze()); - /* - * Now we don't run again until continued. - */ - current->exit_code = 0; -} - /* * This performs the stopping for SIGSTOP and other stop signals. * We have to stop all threads in the thread group. @@ -1696,15 +1673,9 @@ finish_stop(int stop_count) static int do_signal_stop(int signr) { struct signal_struct *sig = current->signal; - int stop_count; + int notify; - if (sig->group_stop_count > 0) { - /* - * There is a group stop in progress. We don't need to - * start another one. - */ - stop_count = --sig->group_stop_count; - } else { + if (!sig->group_stop_count) { struct task_struct *t; if (!likely(sig->flags & SIGNAL_STOP_DEQUEUED) || @@ -1716,7 +1687,7 @@ static int do_signal_stop(int signr) */ sig->group_exit_code = signr; - stop_count = 0; + sig->group_stop_count = 1; for (t = next_thread(current); t != current; t = next_thread(t)) /* * Setting state to TASK_STOPPED for a group @@ -1725,19 +1696,44 @@ static int do_signal_stop(int signr) */ if (!(t->flags & PF_EXITING) && !task_is_stopped_or_traced(t)) { - stop_count++; + sig->group_stop_count++; signal_wake_up(t, 0); } - sig->group_stop_count = stop_count; } + /* + * If there are no other threads in the group, or if there is + * a group stop in progress and we are the last to stop, report + * to the parent. When ptraced, every thread reports itself. + */ + notify = sig->group_stop_count == 1 ? CLD_STOPPED : 0; + notify = tracehook_notify_jctl(notify, CLD_STOPPED); + /* + * tracehook_notify_jctl() can drop and reacquire siglock, so + * we keep ->group_stop_count != 0 before the call. If SIGCONT + * or SIGKILL comes in between ->group_stop_count == 0. + */ + if (sig->group_stop_count) { + if (!--sig->group_stop_count) + sig->flags = SIGNAL_STOP_STOPPED; + current->exit_code = sig->group_exit_code; + __set_current_state(TASK_STOPPED); + } + spin_unlock_irq(¤t->sighand->siglock); - if (stop_count == 0) - sig->flags = SIGNAL_STOP_STOPPED; - current->exit_code = sig->group_exit_code; - __set_current_state(TASK_STOPPED); + if (notify) { + read_lock(&tasklist_lock); + do_notify_parent_cldstop(current, notify); + read_unlock(&tasklist_lock); + } + + /* Now we don't run again until woken by SIGCONT or SIGKILL */ + do { + schedule(); + } while (try_to_freeze()); + + tracehook_finish_jctl(); + current->exit_code = 0; - spin_unlock_irq(¤t->sighand->siglock); - finish_stop(stop_count); return 1; } @@ -1806,14 +1802,15 @@ relock: int why = (signal->flags & SIGNAL_STOP_CONTINUED) ? CLD_CONTINUED : CLD_STOPPED; signal->flags &= ~SIGNAL_CLD_MASK; - spin_unlock_irq(&sighand->siglock); - if (unlikely(!tracehook_notify_jctl(1, why))) - goto relock; + why = tracehook_notify_jctl(why, CLD_CONTINUED); + spin_unlock_irq(&sighand->siglock); - read_lock(&tasklist_lock); - do_notify_parent_cldstop(current->group_leader, why); - read_unlock(&tasklist_lock); + if (why) { + read_lock(&tasklist_lock); + do_notify_parent_cldstop(current->group_leader, why); + read_unlock(&tasklist_lock); + } goto relock; } @@ -1978,14 +1975,14 @@ void exit_signals(struct task_struct *tsk) if (unlikely(tsk->signal->group_stop_count) && !--tsk->signal->group_stop_count) { tsk->signal->flags = SIGNAL_STOP_STOPPED; - group_stop = 1; + group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED); } out: spin_unlock_irq(&tsk->sighand->siglock); - if (unlikely(group_stop) && tracehook_notify_jctl(1, CLD_STOPPED)) { + if (unlikely(group_stop)) { read_lock(&tasklist_lock); - do_notify_parent_cldstop(tsk, CLD_STOPPED); + do_notify_parent_cldstop(tsk, group_stop); read_unlock(&tasklist_lock); } } -- cgit v1.2.2 From a293980c2e261bd5b0d2a77340dd04f684caff58 Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Wed, 23 Sep 2009 15:56:56 -0700 Subject: exec: let do_coredump() limit the number of concurrent dumps to pipes Introduce core pipe limiting sysctl. Since we can dump cores to pipe, rather than directly to the filesystem, we create a condition in which a user can create a very high load on the system simply by running bad applications. If the pipe reader specified in core_pattern is poorly written, we can have lots of ourstandig resources and processes in the system. This sysctl introduces an ability to limit that resource consumption. core_pipe_limit defines how many in-flight dumps may be run in parallel, dumps beyond this value are skipped and a note is made in the kernel log. A special value of 0 in core_pipe_limit denotes unlimited core dumps may be handled (this is the default value). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Neil Horman Reported-by: Earl Chew Cc: Oleg Nesterov Cc: Andi Kleen Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 7f4f57bea4ce..37abb8c3995b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -76,6 +76,7 @@ extern int max_threads; extern int core_uses_pid; extern int suid_dumpable; extern char core_pattern[]; +extern unsigned int core_pipe_limit; extern int pid_max; extern int min_free_kbytes; extern int pid_max_min, pid_max_max; @@ -423,6 +424,14 @@ static struct ctl_table kern_table[] = { .proc_handler = &proc_dostring, .strategy = &sysctl_string, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "core_pipe_limit", + .data = &core_pipe_limit, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, #ifdef CONFIG_PROC_SYSCTL { .procname = "tainted", -- cgit v1.2.2 From 4a30debfb778240a4b1767d4b0c5a5b25ab97160 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 23 Sep 2009 15:57:00 -0700 Subject: signals: introduce do_send_sig_info() helper Introduce do_send_sig_info() and convert group_send_sig_info(), send_sig_info(), do_send_specific() to use this helper. Hopefully it will have more users soon, it allows to specify specific/group behaviour via "bool group" argument. Shaves 80 bytes from .text. Signed-off-by: Oleg Nesterov Cc: Peter Zijlstra Cc: stephane eranian Cc: Ingo Molnar Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 56 +++++++++++++++++++++++++++----------------------------- 1 file changed, 27 insertions(+), 29 deletions(-) (limited to 'kernel') diff --git a/kernel/signal.c b/kernel/signal.c index 5d3b3f8f219b..c6d7a24a86a1 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -971,6 +971,20 @@ specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) return send_signal(sig, info, t, 0); } +int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, + bool group) +{ + unsigned long flags; + int ret = -ESRCH; + + if (lock_task_sighand(p, &flags)) { + ret = send_signal(sig, info, p, group); + unlock_task_sighand(p, &flags); + } + + return ret; +} + /* * Force a signal that the process can't ignore: if necessary * we unblock the signal and change any SIG_IGN to SIG_DFL. @@ -1068,18 +1082,10 @@ struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long */ int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) { - unsigned long flags; - int ret; - - ret = check_kill_permission(sig, info, p); + int ret = check_kill_permission(sig, info, p); - if (!ret && sig) { - ret = -ESRCH; - if (lock_task_sighand(p, &flags)) { - ret = __group_send_sig_info(sig, info, p); - unlock_task_sighand(p, &flags); - } - } + if (!ret && sig) + ret = do_send_sig_info(sig, info, p, true); return ret; } @@ -1224,15 +1230,9 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid) * These are for backward compatibility with the rest of the kernel source. */ -/* - * The caller must ensure the task can't exit. - */ int send_sig_info(int sig, struct siginfo *info, struct task_struct *p) { - int ret; - unsigned long flags; - /* * Make sure legacy kernel users don't send in bad values * (normal paths check this in check_kill_permission). @@ -1240,10 +1240,7 @@ send_sig_info(int sig, struct siginfo *info, struct task_struct *p) if (!valid_signal(sig)) return -EINVAL; - spin_lock_irqsave(&p->sighand->siglock, flags); - ret = specific_send_sig_info(sig, info, p); - spin_unlock_irqrestore(&p->sighand->siglock, flags); - return ret; + return do_send_sig_info(sig, info, p, false); } #define __si_special(priv) \ @@ -2278,7 +2275,6 @@ static int do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) { struct task_struct *p; - unsigned long flags; int error = -ESRCH; rcu_read_lock(); @@ -2288,14 +2284,16 @@ do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) /* * The null signal is a permissions and process existence * probe. No signal is actually delivered. - * - * If lock_task_sighand() fails we pretend the task dies - * after receiving the signal. The window is tiny, and the - * signal is private anyway. */ - if (!error && sig && lock_task_sighand(p, &flags)) { - error = specific_send_sig_info(sig, info, p); - unlock_task_sighand(p, &flags); + if (!error && sig) { + error = do_send_sig_info(sig, info, p, false); + /* + * If lock_task_sighand() failed we pretend the task + * dies after receiving the signal. The window is tiny, + * and the signal is private anyway. + */ + if (unlikely(error == -ESRCH)) + error = 0; } } rcu_read_unlock(); -- cgit v1.2.2 From d9588725e52650e82989707f8fd2feb67ad2dc8e Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 23 Sep 2009 15:57:04 -0700 Subject: signals: inline __fatal_signal_pending __fatal_signal_pending inlines to one instruction on x86, probably two instructions on other machines. It takes two longer x86 instructions just to call it and test its return value, not to mention the function itself. On my random x86_64 config, this saved 70 bytes of text (59 of those being __fatal_signal_pending itself). Signed-off-by: Roland McGrath Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'kernel') diff --git a/kernel/signal.c b/kernel/signal.c index c6d7a24a86a1..6705320784fd 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1050,12 +1050,6 @@ void zap_other_threads(struct task_struct *p) } } -int __fatal_signal_pending(struct task_struct *tsk) -{ - return sigismember(&tsk->pending.signal, SIGKILL); -} -EXPORT_SYMBOL(__fatal_signal_pending); - struct sighand_struct *lock_task_sighand(struct task_struct *tsk, unsigned long *flags) { struct sighand_struct *sighand; -- cgit v1.2.2 From 8d65af789f3e2cf4cfbdbf71a0f7a61ebcd41d38 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Wed, 23 Sep 2009 15:57:19 -0700 Subject: sysctl: remove "struct file *" argument of ->proc_handler It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan Cc: David Howells Cc: "Eric W. Biederman" Cc: Al Viro Cc: Ralf Baechle Cc: Martin Schwidefsky Cc: Ingo Molnar Cc: "David S. Miller" Cc: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/hung_task.c | 4 +-- kernel/sched.c | 4 +-- kernel/sched_fair.c | 4 +-- kernel/slow-work.c | 12 +++---- kernel/softlockup.c | 4 +-- kernel/sysctl.c | 78 ++++++++++++++++++++-------------------------- kernel/trace/ftrace.c | 4 +-- kernel/trace/trace_stack.c | 4 +-- kernel/utsname_sysctl.c | 4 +-- 9 files changed, 53 insertions(+), 65 deletions(-) (limited to 'kernel') diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 022a4927b785..d4e841747400 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -171,12 +171,12 @@ static unsigned long timeout_jiffies(unsigned long timeout) * Process updating of timeout sysctl */ int proc_dohung_task_timeout_secs(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, + void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; - ret = proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos); + ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos); if (ret || !write) goto out; diff --git a/kernel/sched.c b/kernel/sched.c index 0d0361b9dbb3..ee61f454a98b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -10312,7 +10312,7 @@ static int sched_rt_global_constraints(void) #endif /* CONFIG_RT_GROUP_SCHED */ int sched_rt_handler(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, + void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; @@ -10323,7 +10323,7 @@ int sched_rt_handler(struct ctl_table *table, int write, old_period = sysctl_sched_rt_period; old_runtime = sysctl_sched_rt_runtime; - ret = proc_dointvec(table, write, filp, buffer, lenp, ppos); + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (!ret && write) { ret = sched_rt_global_constraints(); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ecc637a0d591..4e777b47eeda 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -384,10 +384,10 @@ static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq) #ifdef CONFIG_SCHED_DEBUG int sched_nr_latency_handler(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, + void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos); + int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (ret || !write) return ret; diff --git a/kernel/slow-work.c b/kernel/slow-work.c index 09d7519557d3..0d31135efbf4 100644 --- a/kernel/slow-work.c +++ b/kernel/slow-work.c @@ -26,10 +26,10 @@ static void slow_work_cull_timeout(unsigned long); static void slow_work_oom_timeout(unsigned long); #ifdef CONFIG_SYSCTL -static int slow_work_min_threads_sysctl(struct ctl_table *, int, struct file *, +static int slow_work_min_threads_sysctl(struct ctl_table *, int, void __user *, size_t *, loff_t *); -static int slow_work_max_threads_sysctl(struct ctl_table *, int , struct file *, +static int slow_work_max_threads_sysctl(struct ctl_table *, int , void __user *, size_t *, loff_t *); #endif @@ -493,10 +493,10 @@ static void slow_work_oom_timeout(unsigned long data) * Handle adjustment of the minimum number of threads */ static int slow_work_min_threads_sysctl(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, + void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos); + int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); int n; if (ret == 0) { @@ -521,10 +521,10 @@ static int slow_work_min_threads_sysctl(struct ctl_table *table, int write, * Handle adjustment of the maximum number of threads */ static int slow_work_max_threads_sysctl(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, + void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret = proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos); + int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); int n; if (ret == 0) { diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 88796c330838..81324d12eb35 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -90,11 +90,11 @@ void touch_all_softlockup_watchdogs(void) EXPORT_SYMBOL(touch_all_softlockup_watchdogs); int proc_dosoftlockup_thresh(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, + void __user *buffer, size_t *lenp, loff_t *ppos) { touch_all_softlockup_watchdogs(); - return proc_dointvec_minmax(table, write, filp, buffer, lenp, ppos); + return proc_dointvec_minmax(table, write, buffer, lenp, ppos); } /* diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 37abb8c3995b..a02697b7cb97 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -163,9 +163,9 @@ extern int max_lock_depth; #endif #ifdef CONFIG_PROC_SYSCTL -static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp, +static int proc_do_cad_pid(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); -static int proc_taint(struct ctl_table *table, int write, struct file *filp, +static int proc_taint(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); #endif @@ -2226,7 +2226,7 @@ void sysctl_head_put(struct ctl_table_header *head) #ifdef CONFIG_PROC_SYSCTL static int _proc_do_string(void* data, int maxlen, int write, - struct file *filp, void __user *buffer, + void __user *buffer, size_t *lenp, loff_t *ppos) { size_t len; @@ -2287,7 +2287,6 @@ static int _proc_do_string(void* data, int maxlen, int write, * proc_dostring - read a string sysctl * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position @@ -2301,10 +2300,10 @@ static int _proc_do_string(void* data, int maxlen, int write, * * Returns 0 on success. */ -int proc_dostring(struct ctl_table *table, int write, struct file *filp, +int proc_dostring(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - return _proc_do_string(table->data, table->maxlen, write, filp, + return _proc_do_string(table->data, table->maxlen, write, buffer, lenp, ppos); } @@ -2329,7 +2328,7 @@ static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp, } static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table, - int write, struct file *filp, void __user *buffer, + int write, void __user *buffer, size_t *lenp, loff_t *ppos, int (*conv)(int *negp, unsigned long *lvalp, int *valp, int write, void *data), @@ -2436,13 +2435,13 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table, #undef TMPBUFLEN } -static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp, +static int do_proc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos, int (*conv)(int *negp, unsigned long *lvalp, int *valp, int write, void *data), void *data) { - return __do_proc_dointvec(table->data, table, write, filp, + return __do_proc_dointvec(table->data, table, write, buffer, lenp, ppos, conv, data); } @@ -2450,7 +2449,6 @@ static int do_proc_dointvec(struct ctl_table *table, int write, struct file *fil * proc_dointvec - read a vector of integers * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position @@ -2460,10 +2458,10 @@ static int do_proc_dointvec(struct ctl_table *table, int write, struct file *fil * * Returns 0 on success. */ -int proc_dointvec(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, + return do_proc_dointvec(table,write,buffer,lenp,ppos, NULL,NULL); } @@ -2471,7 +2469,7 @@ int proc_dointvec(struct ctl_table *table, int write, struct file *filp, * Taint values can only be increased * This means we can safely use a temporary. */ -static int proc_taint(struct ctl_table *table, int write, struct file *filp, +static int proc_taint(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table t; @@ -2483,7 +2481,7 @@ static int proc_taint(struct ctl_table *table, int write, struct file *filp, t = *table; t.data = &tmptaint; - err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos); + err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos); if (err < 0) return err; @@ -2535,7 +2533,6 @@ static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, * proc_dointvec_minmax - read a vector of integers with min/max values * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position @@ -2548,19 +2545,18 @@ static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, * * Returns 0 on success. */ -int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct do_proc_dointvec_minmax_conv_param param = { .min = (int *) table->extra1, .max = (int *) table->extra2, }; - return do_proc_dointvec(table, write, filp, buffer, lenp, ppos, + return do_proc_dointvec(table, write, buffer, lenp, ppos, do_proc_dointvec_minmax_conv, ¶m); } static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul, @@ -2665,21 +2661,19 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int } static int do_proc_doulongvec_minmax(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul, unsigned long convdiv) { return __do_proc_doulongvec_minmax(table->data, table, write, - filp, buffer, lenp, ppos, convmul, convdiv); + buffer, lenp, ppos, convmul, convdiv); } /** * proc_doulongvec_minmax - read a vector of long integers with min/max values * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position @@ -2692,17 +2686,16 @@ static int do_proc_doulongvec_minmax(struct ctl_table *table, int write, * * Returns 0 on success. */ -int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp, +int proc_doulongvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l); + return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l); } /** * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position @@ -2717,11 +2710,10 @@ int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp * Returns 0 on success. */ int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) { - return do_proc_doulongvec_minmax(table, write, filp, buffer, + return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, HZ, 1000l); } @@ -2797,7 +2789,6 @@ static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp, * proc_dointvec_jiffies - read a vector of integers as seconds * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position @@ -2809,10 +2800,10 @@ static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp, * * Returns 0 on success. */ -int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, + return do_proc_dointvec(table,write,buffer,lenp,ppos, do_proc_dointvec_jiffies_conv,NULL); } @@ -2820,7 +2811,6 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp, * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: pointer to the file position @@ -2832,10 +2822,10 @@ int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp, * * Returns 0 on success. */ -int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - return do_proc_dointvec(table,write,filp,buffer,lenp,ppos, + return do_proc_dointvec(table,write,buffer,lenp,ppos, do_proc_dointvec_userhz_jiffies_conv,NULL); } @@ -2843,7 +2833,6 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file - * @filp: the file structure * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position @@ -2856,14 +2845,14 @@ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file * * Returns 0 on success. */ -int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - return do_proc_dointvec(table, write, filp, buffer, lenp, ppos, + return do_proc_dointvec(table, write, buffer, lenp, ppos, do_proc_dointvec_ms_jiffies_conv, NULL); } -static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp, +static int proc_do_cad_pid(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct pid *new_pid; @@ -2872,7 +2861,7 @@ static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp tmp = pid_vnr(cad_pid); - r = __do_proc_dointvec(&tmp, table, write, filp, buffer, + r = __do_proc_dointvec(&tmp, table, write, buffer, lenp, ppos, NULL, NULL); if (r || !write) return r; @@ -2887,50 +2876,49 @@ static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp #else /* CONFIG_PROC_FS */ -int proc_dostring(struct ctl_table *table, int write, struct file *filp, +int proc_dostring(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } -int proc_dointvec(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } -int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } -int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } -int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } -int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp, +int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } -int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp, +int proc_doulongvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write, - struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) { diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 23df7771c937..a142579765bf 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3015,7 +3015,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops) int ftrace_enable_sysctl(struct ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *lenp, + void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; @@ -3025,7 +3025,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, mutex_lock(&ftrace_lock); - ret = proc_dointvec(table, write, file, buffer, lenp, ppos); + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) goto out; diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 0f6facb050a1..8504ac71e4e8 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -296,14 +296,14 @@ static const struct file_operations stack_trace_fops = { int stack_trace_sysctl(struct ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *lenp, + void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; mutex_lock(&stack_sysctl_mutex); - ret = proc_dointvec(table, write, file, buffer, lenp, ppos); + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret || !write || (last_stack_tracer_enabled == !!stack_tracer_enabled)) diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c index 92359cc747a7..69eae358a726 100644 --- a/kernel/utsname_sysctl.c +++ b/kernel/utsname_sysctl.c @@ -42,14 +42,14 @@ static void put_uts(ctl_table *table, int write, void *which) * Special case of dostring for the UTS structure. This has locks * to observe. Should this be in kernel/sys.c ???? */ -static int proc_do_uts_string(ctl_table *table, int write, struct file *filp, +static int proc_do_uts_string(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table uts_table; int r; memcpy(&uts_table, table, sizeof(uts_table)); uts_table.data = get_uts(table, write); - r = proc_dostring(&uts_table,write,filp,buffer,lenp, ppos); + r = proc_dostring(&uts_table,write,buffer,lenp, ppos); put_uts(table, write, uts_table.data); return r; } -- cgit v1.2.2 From 123be07b0b399670a7cc3d82fef0cb4f93ef885c Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Wed, 23 Sep 2009 15:57:20 -0700 Subject: fork(): disable CLONE_PARENT for init When global or container-init processes use CLONE_PARENT, they create a multi-rooted process tree. Besides siblings of global init remain as zombies on exit since they are not reaped by their parent (swapper). So prevent global and container-inits from creating siblings. Signed-off-by: Sukadev Bhattiprolu Acked-by: Eric W. Biederman Acked-by: Roland McGrath Cc: Oren Laadan Cc: Oleg Nesterov Cc: Serge Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index 51ad0b0b7266..b51fd2ccb2f1 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -979,6 +979,16 @@ static struct task_struct *copy_process(unsigned long clone_flags, if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM)) return ERR_PTR(-EINVAL); + /* + * Siblings of global init remain as zombies on exit since they are + * not reaped by their parent (swapper). To solve this and to avoid + * multi-rooted process trees, prevent global and container-inits + * from creating siblings. + */ + if ((clone_flags & CLONE_PARENT) && + current->signal->flags & SIGNAL_UNKILLABLE) + return ERR_PTR(-EINVAL); + retval = security_task_create(clone_flags); if (retval) goto fork_out; -- cgit v1.2.2 From e5a4738699d6eca408dcb225bd350413927701e2 Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu Date: Wed, 23 Sep 2009 15:57:22 -0700 Subject: pidns: deny CLONE_PARENT|CLONE_NEWPID combination CLONE_PARENT was used to implement an older threading model. For consistency with the CLONE_THREAD check in copy_pid_ns(), disable CLONE_PARENT with CLONE_NEWPID, at least until the required semantics of pid namespaces are clear. Signed-off-by: Sukadev Bhattiprolu Acked-by: Roland McGrath Acked-by: Serge Hallyn Cc: Oren Laadan Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/pid_namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 821722ae58a7..86b3796b0436 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -118,7 +118,7 @@ struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old { if (!(flags & CLONE_NEWPID)) return get_pid_ns(old_ns); - if (flags & CLONE_THREAD) + if (flags & (CLONE_THREAD|CLONE_PARENT)) return ERR_PTR(-EINVAL); return create_pid_namespace(old_ns); } -- cgit v1.2.2 From 858f09930b32c11b40fd0c5c467982ba09b10894 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Wed, 23 Sep 2009 15:57:32 -0700 Subject: aio: ifdef fields in mm_struct ->ioctx_lock and ->ioctx_list are used only under CONFIG_AIO. Signed-off-by: Alexey Dobriyan Cc: Zach Brown Cc: Benjamin LaHaise Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/fork.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index b51fd2ccb2f1..e49f181ba1ca 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -434,6 +434,14 @@ __setup("coredump_filter=", coredump_filter_setup); #include +static void mm_init_aio(struct mm_struct *mm) +{ +#ifdef CONFIG_AIO + spin_lock_init(&mm->ioctx_lock); + INIT_HLIST_HEAD(&mm->ioctx_list); +#endif +} + static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) { atomic_set(&mm->mm_users, 1); @@ -447,10 +455,9 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p) set_mm_counter(mm, file_rss, 0); set_mm_counter(mm, anon_rss, 0); spin_lock_init(&mm->page_table_lock); - spin_lock_init(&mm->ioctx_lock); - INIT_HLIST_HEAD(&mm->ioctx_list); mm->free_area_cache = TASK_UNMAPPED_BASE; mm->cached_hole_size = ~0UL; + mm_init_aio(mm); mm_init_owner(mm, p); if (likely(!mm_alloc_pgd(mm))) { -- cgit v1.2.2 From 801460d0cf5c5288153b722565773059b0f44348 Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto Date: Wed, 23 Sep 2009 15:57:41 -0700 Subject: task_struct cleanup: move binfmt field to mm_struct Because the binfmt is not different between threads in the same process, it can be moved from task_struct to mm_struct. And binfmt moudle is handled per mm_struct instead of task_struct. Signed-off-by: Hiroshi Shimamoto Acked-by: Oleg Nesterov Cc: Rusty Russell Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 2 -- kernel/fork.c | 13 +++++++------ 2 files changed, 7 insertions(+), 8 deletions(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index 6c75ff83a8fe..5859f598c951 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -976,8 +976,6 @@ NORET_TYPE void do_exit(long code) disassociate_ctty(1); module_put(task_thread_info(tsk)->exec_domain->module); - if (tsk->binfmt) - module_put(tsk->binfmt->module); proc_exit_connector(tsk); diff --git a/kernel/fork.c b/kernel/fork.c index e49f181ba1ca..266c6af6ef1b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -518,6 +518,8 @@ void mmput(struct mm_struct *mm) spin_unlock(&mmlist_lock); } put_swap_token(mm); + if (mm->binfmt) + module_put(mm->binfmt->module); mmdrop(mm); } } @@ -643,9 +645,14 @@ struct mm_struct *dup_mm(struct task_struct *tsk) mm->hiwater_rss = get_mm_rss(mm); mm->hiwater_vm = mm->total_vm; + if (mm->binfmt && !try_module_get(mm->binfmt->module)) + goto free_pt; + return mm; free_pt: + /* don't put binfmt in mmput, we haven't got module yet */ + mm->binfmt = NULL; mmput(mm); fail_nomem: @@ -1037,9 +1044,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, if (!try_module_get(task_thread_info(p)->exec_domain->module)) goto bad_fork_cleanup_count; - if (p->binfmt && !try_module_get(p->binfmt->module)) - goto bad_fork_cleanup_put_domain; - p->did_exec = 0; delayacct_tsk_init(p); /* Must remain after dup_task_struct() */ copy_flags(clone_flags, p); @@ -1327,9 +1331,6 @@ bad_fork_cleanup_cgroup: #endif cgroup_exit(p, cgroup_callbacks_done); delayacct_tsk_free(p); - if (p->binfmt) - module_put(p->binfmt->module); -bad_fork_cleanup_put_domain: module_put(task_thread_info(p)->exec_domain->module); bad_fork_cleanup_count: atomic_dec(&p->cred->user->processes); -- cgit v1.2.2 From 4a4962263f07d14660849ec134ee42b63e95ea9a Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 6 Jul 2009 14:50:42 +0100 Subject: module: reduce symbol table for loaded modules (v2) Discard all symbols not interesting for kallsyms use: absolute, section, and in the common case (!KALLSYMS_ALL) data ones. Signed-off-by: Jan Beulich Signed-off-by: Rusty Russell --- kernel/module.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 87 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index e6bc4b28aa62..97f4d5e15535 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1862,13 +1862,68 @@ static char elf_type(const Elf_Sym *sym, return '?'; } +static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, + unsigned int shnum) +{ + const Elf_Shdr *sec; + + if (src->st_shndx == SHN_UNDEF + || src->st_shndx >= shnum + || !src->st_name) + return false; + + sec = sechdrs + src->st_shndx; + if (!(sec->sh_flags & SHF_ALLOC) +#ifndef CONFIG_KALLSYMS_ALL + || !(sec->sh_flags & SHF_EXECINSTR) +#endif + || (sec->sh_entsize & INIT_OFFSET_MASK)) + return false; + + return true; +} + +static unsigned long layout_symtab(struct module *mod, + Elf_Shdr *sechdrs, + unsigned int symindex, + const Elf_Ehdr *hdr, + const char *secstrings) +{ + unsigned long symoffs; + Elf_Shdr *symsect = sechdrs + symindex; + const Elf_Sym *src; + unsigned int i, nsrc, ndst; + + /* Put symbol section at end of init part of module. */ + symsect->sh_flags |= SHF_ALLOC; + symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect, + symindex) | INIT_OFFSET_MASK; + DEBUGP("\t%s\n", secstrings + symsect->sh_name); + + src = (void *)hdr + symsect->sh_offset; + nsrc = symsect->sh_size / sizeof(*src); + for (ndst = i = 1; i < nsrc; ++i, ++src) + if (is_core_symbol(src, sechdrs, hdr->e_shnum)) + ++ndst; + + /* Append room for core symbols at end of core part. */ + symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1); + mod->core_size = symoffs + ndst * sizeof(Elf_Sym); + + return symoffs; +} + static void add_kallsyms(struct module *mod, Elf_Shdr *sechdrs, + unsigned int shnum, unsigned int symindex, unsigned int strindex, + unsigned long symoffs, const char *secstrings) { - unsigned int i; + unsigned int i, ndst; + const Elf_Sym *src; + Elf_Sym *dst; mod->symtab = (void *)sechdrs[symindex].sh_addr; mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym); @@ -1878,12 +1933,32 @@ static void add_kallsyms(struct module *mod, for (i = 0; i < mod->num_symtab; i++) mod->symtab[i].st_info = elf_type(&mod->symtab[i], sechdrs, secstrings, mod); + + mod->core_symtab = dst = mod->module_core + symoffs; + src = mod->symtab; + *dst = *src; + for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) { + if (!is_core_symbol(src, sechdrs, shnum)) + continue; + dst[ndst] = *src; + ++ndst; + } + mod->core_num_syms = ndst; } #else +static inline unsigned long layout_symtab(struct module *mod, + Elf_Shdr *sechdrs, + unsigned int symindex, + const Elf_Hdr *hdr, + const char *secstrings) +{ +} static inline void add_kallsyms(struct module *mod, Elf_Shdr *sechdrs, + unsigned int shnum, unsigned int symindex, unsigned int strindex, + unsigned long symoffs, const char *secstrings) { } @@ -1959,6 +2034,9 @@ static noinline struct module *load_module(void __user *umod, struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ +#ifdef CONFIG_KALLSYMS + unsigned long symoffs; +#endif mm_segment_t old_fs; DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", @@ -2041,8 +2119,7 @@ static noinline struct module *load_module(void __user *umod, sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC; sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC; #ifdef CONFIG_KALLSYMS - /* Keep symbol and string tables for decoding later. */ - sechdrs[symindex].sh_flags |= SHF_ALLOC; + /* Keep string table for decoding later. */ sechdrs[strindex].sh_flags |= SHF_ALLOC; #endif @@ -2109,6 +2186,7 @@ static noinline struct module *load_module(void __user *umod, this is done generically; there doesn't appear to be any special cases for the architectures. */ layout_sections(mod, hdr, sechdrs, secstrings); + symoffs = layout_symtab(mod, sechdrs, symindex, hdr, secstrings); /* Do the allocs. */ ptr = module_alloc_update_bounds(mod->core_size); @@ -2313,7 +2391,8 @@ static noinline struct module *load_module(void __user *umod, percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr, sechdrs[pcpuindex].sh_size); - add_kallsyms(mod, sechdrs, symindex, strindex, secstrings); + add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex, + symoffs, secstrings); if (!mod->taints) { struct _ddebug *debug; @@ -2491,6 +2570,10 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, /* Drop initial reference. */ module_put(mod); trim_init_extable(mod); +#ifdef CONFIG_KALLSYMS + mod->num_symtab = mod->core_num_syms; + mod->symtab = mod->core_symtab; +#endif module_free(mod, mod->module_init); mod->module_init = NULL; mod->init_size = 0; -- cgit v1.2.2 From 554bdfe5acf3715e87c8d5e25a4f9a896ac9f014 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 6 Jul 2009 14:51:44 +0100 Subject: module: reduce string table for loaded modules (v2) Also remove all parts of the string table (referenced by the symbol table) that are not needed for kallsyms use (i.e. which were only referenced by symbols discarded by the previous patch, or not referenced at all for whatever reason). Signed-off-by: Jan Beulich Signed-off-by: Rusty Russell --- kernel/module.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 56 insertions(+), 12 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 97f4d5e15535..39827c3d9484 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1886,12 +1886,17 @@ static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, static unsigned long layout_symtab(struct module *mod, Elf_Shdr *sechdrs, unsigned int symindex, + unsigned int strindex, const Elf_Ehdr *hdr, - const char *secstrings) + const char *secstrings, + unsigned long *pstroffs, + unsigned long *strmap) { unsigned long symoffs; Elf_Shdr *symsect = sechdrs + symindex; + Elf_Shdr *strsect = sechdrs + strindex; const Elf_Sym *src; + const char *strtab; unsigned int i, nsrc, ndst; /* Put symbol section at end of init part of module. */ @@ -1902,14 +1907,31 @@ static unsigned long layout_symtab(struct module *mod, src = (void *)hdr + symsect->sh_offset; nsrc = symsect->sh_size / sizeof(*src); + strtab = (void *)hdr + strsect->sh_offset; for (ndst = i = 1; i < nsrc; ++i, ++src) - if (is_core_symbol(src, sechdrs, hdr->e_shnum)) + if (is_core_symbol(src, sechdrs, hdr->e_shnum)) { + unsigned int j = src->st_name; + + while(!__test_and_set_bit(j, strmap) && strtab[j]) + ++j; ++ndst; + } /* Append room for core symbols at end of core part. */ symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1); mod->core_size = symoffs + ndst * sizeof(Elf_Sym); + /* Put string table section at end of init part of module. */ + strsect->sh_flags |= SHF_ALLOC; + strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect, + strindex) | INIT_OFFSET_MASK; + DEBUGP("\t%s\n", secstrings + strsect->sh_name); + + /* Append room for core symbols' strings at end of core part. */ + *pstroffs = mod->core_size; + __set_bit(0, strmap); + mod->core_size += bitmap_weight(strmap, strsect->sh_size); + return symoffs; } @@ -1919,11 +1941,14 @@ static void add_kallsyms(struct module *mod, unsigned int symindex, unsigned int strindex, unsigned long symoffs, - const char *secstrings) + unsigned long stroffs, + const char *secstrings, + unsigned long *strmap) { unsigned int i, ndst; const Elf_Sym *src; Elf_Sym *dst; + char *s; mod->symtab = (void *)sechdrs[symindex].sh_addr; mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym); @@ -1941,16 +1966,25 @@ static void add_kallsyms(struct module *mod, if (!is_core_symbol(src, sechdrs, shnum)) continue; dst[ndst] = *src; + dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name); ++ndst; } mod->core_num_syms = ndst; + + mod->core_strtab = s = mod->module_core + stroffs; + for (*s = 0, i = 1; i < sechdrs[strindex].sh_size; ++i) + if (test_bit(i, strmap)) + *++s = mod->strtab[i]; } #else static inline unsigned long layout_symtab(struct module *mod, Elf_Shdr *sechdrs, unsigned int symindex, + unsigned int strindex, const Elf_Hdr *hdr, - const char *secstrings) + const char *secstrings, + unsigned long *pstroffs, + unsigned long *strmap) { } static inline void add_kallsyms(struct module *mod, @@ -1959,7 +1993,9 @@ static inline void add_kallsyms(struct module *mod, unsigned int symindex, unsigned int strindex, unsigned long symoffs, - const char *secstrings) + unsigned long stroffs, + const char *secstrings, + const unsigned long *strmap) { } #endif /* CONFIG_KALLSYMS */ @@ -2035,7 +2071,7 @@ static noinline struct module *load_module(void __user *umod, long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ #ifdef CONFIG_KALLSYMS - unsigned long symoffs; + unsigned long symoffs, stroffs, *strmap; #endif mm_segment_t old_fs; @@ -2118,10 +2154,6 @@ static noinline struct module *load_module(void __user *umod, /* Don't keep modinfo and version sections. */ sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC; sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC; -#ifdef CONFIG_KALLSYMS - /* Keep string table for decoding later. */ - sechdrs[strindex].sh_flags |= SHF_ALLOC; -#endif /* Check module struct version now, before we try to use module. */ if (!check_modstruct_version(sechdrs, versindex, mod)) { @@ -2157,6 +2189,13 @@ static noinline struct module *load_module(void __user *umod, goto free_hdr; } + strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size) + * sizeof(long), GFP_KERNEL); + if (!strmap) { + err = -ENOMEM; + goto free_mod; + } + if (find_module(mod->name)) { err = -EEXIST; goto free_mod; @@ -2186,7 +2225,8 @@ static noinline struct module *load_module(void __user *umod, this is done generically; there doesn't appear to be any special cases for the architectures. */ layout_sections(mod, hdr, sechdrs, secstrings); - symoffs = layout_symtab(mod, sechdrs, symindex, hdr, secstrings); + symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr, + secstrings, &stroffs, strmap); /* Do the allocs. */ ptr = module_alloc_update_bounds(mod->core_size); @@ -2392,7 +2432,9 @@ static noinline struct module *load_module(void __user *umod, sechdrs[pcpuindex].sh_size); add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex, - symoffs, secstrings); + symoffs, stroffs, secstrings, strmap); + kfree(strmap); + strmap = NULL; if (!mod->taints) { struct _ddebug *debug; @@ -2481,6 +2523,7 @@ static noinline struct module *load_module(void __user *umod, percpu_modfree(percpu); free_mod: kfree(args); + kfree(strmap); free_hdr: vfree(hdr); return ERR_PTR(err); @@ -2573,6 +2616,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, #ifdef CONFIG_KALLSYMS mod->num_symtab = mod->core_num_syms; mod->symtab = mod->core_symtab; + mod->strtab = mod->core_strtab; #endif module_free(mod, mod->module_init); mod->module_init = NULL; -- cgit v1.2.2 From 26d052bfce799ef0e7262695b46e3525ca4d381d Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter Date: Mon, 6 Jul 2009 17:11:22 +0200 Subject: param: allow whitespace as kernel parameter separator Some boot mechanisms require that kernel parameters are stored in a separate file which is loaded to memory without further processing (e.g. the "Load from FTP" method on s390). When such a file contains newline characters, the kernel parameter preceding the newline might not be correctly parsed (due to the newline being stuck to the end of the actual parameter value) which can lead to boot failures. This patch improves kernel command line usability in such a situation by allowing generic whitespace characters as separators between kernel parameters. Signed-off-by: Peter Oberparleiter Signed-off-by: Rusty Russell --- kernel/params.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel') diff --git a/kernel/params.c b/kernel/params.c index 7f6912ced2ba..9da58eabdcb2 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -23,6 +23,7 @@ #include #include #include +#include #if 0 #define DEBUGP printk @@ -87,7 +88,7 @@ static char *next_arg(char *args, char **param, char **val) } for (i = 0; args[i]; i++) { - if (args[i] == ' ' && !in_quote) + if (isspace(args[i]) && !in_quote) break; if (equals == 0) { if (args[i] == '=') @@ -121,7 +122,7 @@ static char *next_arg(char *args, char **param, char **val) next = args + i; /* Chew up trailing spaces. */ - while (*next == ' ') + while (isspace(*next)) next++; return next; } @@ -138,7 +139,7 @@ int parse_args(const char *name, DEBUGP("Parsing ARGS: %s\n", args); /* Chew leading spaces */ - while (*args == ' ') + while (isspace(*args)) args++; while (*args) { -- cgit v1.2.2 From a263f7763c364015f92e7c097fa46c6673f6fcb0 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 25 Sep 2009 00:32:58 -0600 Subject: module: fix memory leak when load fails after srcversion/version allocated Normally the twisty paths of sysfs will free the attributes, but not if we fail before we hook it into sysfs (which is the last thing we do in load_module). (This sysfs code is a turd, no doubt there are other issues lurking too). Reported-by: Tetsuo Handa Signed-off-by: Rusty Russell Cc: Catalin Marinas Tested-by: Tetsuo Handa --- kernel/module.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 39827c3d9484..c54f10d90e1c 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1797,6 +1797,17 @@ static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs, } } +static void free_modinfo(struct module *mod) +{ + struct module_attribute *attr; + int i; + + for (i = 0; (attr = modinfo_attrs[i]); i++) { + if (attr->free) + attr->free(mod); + } +} + #ifdef CONFIG_KALLSYMS /* lookup symbol in given range of kernel_symbols */ @@ -2506,6 +2517,7 @@ static noinline struct module *load_module(void __user *umod, synchronize_sched(); module_arch_cleanup(mod); cleanup: + free_modinfo(mod); kobject_del(&mod->mkobj.kobj); kobject_put(&mod->mkobj.kobj); free_unload: -- cgit v1.2.2 From ffa9f12a41ec117207e8d953f90b9c179546c8d7 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 25 Sep 2009 00:32:59 -0600 Subject: module: don't call percpu_modfree on NULL pointer. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The general one handles NULL, the static obsolescent (CONFIG_HAVE_LEGACY_PER_CPU_AREA) one in module.c doesn't; Eric's commit 720eba31 assumed it did, and various frobbings since then kept that assumption. All other callers in module.c all protect it with an if; this effectively does the same as free_init is only goto if we fail percpu_modalloc(). Reported-by: Kamalesh Babulal Signed-off-by: Rusty Russell Cc: Eric Dumazet Cc: Masami Hiramatsu Cc: Américo Wang Tested-by: Kamalesh Babulal --- kernel/module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index c54f10d90e1c..5a29397ca4b6 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2523,8 +2523,8 @@ static noinline struct module *load_module(void __user *umod, free_unload: module_unload_free(mod); #if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP) - free_init: percpu_modfree(mod->refptr); + free_init: #endif module_free(mod, mod->module_init); free_core: -- cgit v1.2.2