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