Michal Hocko
7a05c0f7bb
watchdog: make sure the watchdog thread gets CPU on loaded system ...
If the system is loaded while hotplugging a CPU we might end up with a
bogus hardlockup detection. This has been seen during LTP pounder test
executed in parallel with hotplug test.
The main problem is that enable_watchdog (called when CPU is brought up)
registers perf event which periodically checks per-cpu counter
(hrtimer_interrupts), updated from a hrtimer callback, but the hrtimer
is fired from the kernel thread.
This means that while we already do check for the hard lockup the kernel
thread might be sitting on the runqueue with zillions of tasks so there
is nobody to update the value we rely on and so we KABOOM.
Let's fix this by boosting the watchdog thread priority before we wake
it up rather than when it's already running. This still doesn't handle
a case where we have the same amount of high prio FIFO tasks but that
doesn't seem to be common. The current implementation doesn't handle
that case anyway so this is not worse at least.
Unfortunately, we cannot start perf counter from the watchdog thread
because we could miss a real lock up and also we cannot start the
hrtimer watchdog_enable because we there is no way (at least I don't
know any) to start a hrtimer from a different CPU.
[dzickus@redhat.com: fix compile issue with param]
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-23 16:58:32 -07:00
Fixes:
2012-03-23 09:29:44 -07:00
Merge branch 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2012-03-20 18:11:21 -07:00
gcov: disable CONSTRUCTORS for UML
2011-07-26 16:49:45 -07:00
Generialize powerpc's irq_host as irq_domain
2012-03-21 10:27:19 -07:00
Power management updates for 3.4
2012-03-21 10:15:51 -07:00
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2012-03-21 13:25:04 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
2012-03-22 20:20:18 -07:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2012-03-21 13:36:41 -07:00
Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2012-01-08 12:19:57 -08:00
kernel/async: remove redundant declaration.
2012-01-13 09:32:18 +10:30
constify path argument of audit_log_d_path()
2012-03-20 21:29:40 -04:00
audit: remove AUDIT_SETUP_CONTEXT as it isn't used
2012-01-17 16:16:57 -05:00
audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()
2011-07-20 14:10:11 -07:00
audit: allow interfield comparison in audit rules
2012-01-17 16:17:01 -05:00
kernel-doc: fix new warnings in auditsc.c
2012-01-23 08:44:53 -08:00
Revert "capabitlies: ns_capable can use the cap helpers rather than lsm call"
2012-01-17 10:19:41 -08:00
Merge branch 'akpm' (Andrew's patch-bomb)
2012-03-22 09:04:48 -07:00
cgroup: remove cgroup_subsys argument from callbacks
2012-02-02 09:20:22 -08:00
kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure
2011-10-31 19:30:05 -04:00
kernel/configs.c: include MODULE_*() when CONFIG_IKCONFIG_PROC=n
2011-07-25 20:57:15 -07:00
Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
2012-01-08 13:10:57 -08:00
cpu_pm: call notifiers during suspend
2011-09-23 12:05:29 +05:30
cpuset: mm: reduce large amounts of memory barrier related damage v3
2012-03-21 17:54:59 -07:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
security: trim security.h
2012-02-14 10:45:42 +11:00
KVM: Steal time implementation
2011-07-14 12:59:14 +03:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel/exit.c: if init dies, log a signal which killed it, if any
2012-03-23 16:58:32 -07:00
extable, core_kernel_data(): Make sure all archs define _sdata
2011-05-20 08:56:56 +02:00
prctl: add PR_{SET,GET}_CHILD_SUBREAPER to allow simple process supervision
2012-03-23 16:58:32 -07:00
PM / Freezer: Remove references to TIF_FREEZE in comments
2012-03-04 23:08:54 +01:00
Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-19 17:11:15 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2011-11-28 08:43:52 -08:00
hung_task: fix the broken rcu_lock_break() logic
2012-03-05 15:49:42 -08:00
kernel: fix two implicit header assumptions in irq_work.c
2011-10-31 09:20:12 -04:00
[S390] cputime: add sparse checking and cleanup
2011-12-15 14:56:19 +01:00
static keys: Inline the static_key_enabled() function
2012-02-28 20:01:08 +01:00
sched: Isolate preempt counting in its own config option
2011-06-10 15:15:40 +02:00
PM / Sleep: Introduce "late suspend" and "early resume" of devices
2012-01-29 20:38:29 +01:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'pm-sleep' into pm-for-linus
2011-12-25 23:42:20 +01:00
kprobes: return proper error code from register_kprobe()
2012-03-05 15:49:42 -08:00
kernel: ksysfs.c is implicitly using stat.h
2011-10-31 09:20:13 -04:00
freezer: kill unused set_freezable_with_signal()
2011-11-23 09:28:17 -08:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
lockdep: Add CPU-idle/offline warning to lockdep-RCU splat
2012-02-21 09:06:06 -08:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
PM: Make sysrq-o be available for CONFIG_PM unset
2012-01-14 00:33:03 +01:00
error: implicit declaration of function 'module_flags_taint'
2012-01-15 16:21:07 -08:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
sched/rt: Use schedule_preempt_disabled()
2012-03-01 10:28:03 +01:00
mutex: Use p->on_cpu for the adaptive spin
2011-04-14 08:52:33 +02:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
padata: Fix race on sequence number wrap
2012-03-14 17:25:56 +08:00
panic: don't print redundant backtraces on oops
2012-01-12 20:13:11 -08:00
module: make module param bint handle nul value
2012-02-14 11:02:15 +10:30
vfs: fix panic in __d_lookup() with high dentry hashtable counts
2012-02-13 20:45:38 -05:00
sysctl: add the kernel.ns_last_pid control
2012-01-12 20:13:11 -08:00
[S390] cputime: add sparse checking and cleanup
2011-12-15 14:56:19 +01:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-20 10:31:44 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security
2012-01-14 18:36:33 -08:00
range: fix bogus misuse of module.h to get printk()
2011-10-31 09:20:11 -04:00
rcu: Allow nesting of rcu_idle_enter() and rcu_idle_exit()
2012-02-21 09:06:12 -08:00
rcu: Check for illegal use of RCU from offlined CPUs
2012-02-21 09:06:03 -08:00
rcu: Add RCU_NONIDLE() for idle-loop RCU read-side critical sections
2012-02-21 09:06:13 -08:00
rcu: Simplify unboosting checks
2012-02-21 09:03:43 -08:00
PTR_ERR should be called before its argument is cleared.
2012-02-21 09:06:10 -08:00
rcu: Stop spurious warnings from synchronize_sched_expedited
2012-02-21 15:33:34 -08:00
rcu: Rework detection of use of RCU by offline CPUs
2012-02-21 09:06:07 -08:00
rcu: Hold off RCU_FAST_NO_HZ after timer posted
2012-02-21 09:42:30 -08:00
rcu: Rework detection of use of RCU by offline CPUs
2012-02-21 09:06:07 -08:00
relay: prevent integer overflow in relay_open()
2012-02-10 09:04:49 +01:00
net: introduce res_counter_charge_nofail() for socket allocations
2012-01-22 15:08:46 -05:00
kernel/resource.c: move EXPORT_SYMBOL right after definition
2012-02-03 23:37:07 +01:00
lockdep, rtmutex, bug: Show taint flags on error
2011-12-06 08:16:49 +01:00
rtmutex-tester: convert sysdev_class to a regular subsystem
2011-12-14 14:54:22 -08:00
Revert "rcu: Permit rt_mutex_unlock() with irqs disabled"
2011-12-11 10:33:18 -08:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
seccomp: audit abnormal end to a process due to seccomp
2012-01-17 16:16:55 -05:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
exit_signal: fix the "parent has changed security domain" logic
2012-03-20 14:16:50 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-03-20 10:32:09 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
rcu: Call out dangers of expedited RCU primitives
2012-02-21 09:06:08 -08:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
prctl: add PR_{SET,GET}_CHILD_SUBREAPER to allow simple process supervision
2012-03-23 16:58:32 -07:00
Cross Memory Attach
2011-10-31 17:30:44 -07:00
security: trim security.h
2012-02-14 10:45:42 +11:00
binary_sysctl(): fix memory leak
2011-12-20 10:25:04 -08:00
xfs: remove subdirectories
2011-08-12 16:21:35 -05:00
Make TASKSTATS require root access
2011-09-19 17:04:37 -07:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-01-06 07:53:34 -08:00
static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]()
2012-02-24 10:05:59 +01:00
[S390] cputime: add sparse checking and cleanup
2011-12-15 14:56:19 +01:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
kernel: Map most files to use export.h instead of module.h
2011-10-31 09:20:12 -04:00
Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2011-11-06 19:44:47 -08:00
lockdep/waitqueues: Add better annotation
2011-12-21 10:07:39 +01:00
watchdog: make sure the watchdog thread gets CPU on loaded system
2012-03-23 16:58:32 -07:00
Merge branch 'for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2012-03-20 18:13:22 -07:00
7a05c0f7bb