Re: [PATCH][GIT PULL] tracing: Fix compile issue fortrace_sched_wakeup.c

From: Ingo Molnar
Date: Thu Oct 21 2010 - 07:26:41 EST



* Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Wed, 2010-10-20 at 17:40 +0200, Ingo Molnar wrote:
> > FYI, there's a new mystery hang (sometimes crash) that triggers in -tip - and which
> > seems to be tracing related. See the crashlog below - config attached.
> >
> > It's not bisectable - small changes in the kernel make the bug come/go. (might be a
> > race of some sorts)
> >
>
>
> > [ 42.324027] Testing all events:
> > [ 245.668090] INFO: task swapper:1 blocked for more than 120 seconds.
> > [ 245.672051] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> > [ 245.676026] swapper D f6420b40 6544 1 0 0x00000000
> > [ 245.684051] f6437dac 00000046 f694aac0 f6420b40 f6438000 f6437d74 f6438294 f6438290
> > [ 245.692237] c2192ac0 c204e6c0 c2192ac0 c2192ac0 f6438290 00000000 f6438000 ff2ffa7d
> > [ 245.701068] 00000009 f6420b40 f6437e5c 7fffffff f6438000 f6437dfc f6437e5c 7fffffff
> > [ 245.709071] Call Trace:
> > [ 245.711551] [<c1a7f561>] schedule_timeout+0x1c/0x1e7
> > [ 245.712036] [<c1a818b6>] ? _raw_spin_unlock_irq+0x2d/0x43
> > [ 245.716037] [<c1027f2d>] ? sub_preempt_count+0x4/0x98
> > [ 245.720061] [<c1a818b6>] ? _raw_spin_unlock_irq+0x2d/0x43
> > [ 245.724036] [<c1027fb4>] ? sub_preempt_count+0x8b/0x98
> > [ 245.728036] [<c1a7e76b>] wait_for_common+0xc1/0x11a
> > [ 245.732062] [<c102de32>] ? default_wake_function+0x0/0x12
> > [ 245.736041] [<c1a7e863>] wait_for_completion+0x17/0x19
> > [ 245.740069] [<c10667a2>] __stop_cpus+0xdd/0x103
> > [ 245.744072] [<c1a7e6db>] ? wait_for_common+0x31/0x11a
> > [ 245.748040] [<c10665a4>] ? stop_machine_cpu_stop+0x0/0x9a
> > [ 245.752040] [<c106683d>] stop_cpus+0x2c/0x3f
> > [ 245.756069] [<c10668af>] __stop_machine+0x5f/0x67
> > [ 245.760186] [<c1006240>] ? stop_machine_text_poke+0x0/0x43
> > [ 245.764040] [<c1006240>] ? stop_machine_text_poke+0x0/0x43
> > [ 245.768071] [<c19f0a73>] ? cfdgml_create+0x2b/0xde
> > [ 245.772040] [<c10060fd>] text_poke_smp+0x3a/0x42
> > [ 245.776039] [<c19f0a73>] ? cfdgml_create+0x2b/0xde
>
>
> > [ 245.780098] [<c1005b9c>] arch_jump_label_transform+0x53/0x67
> > [ 245.784042] [<c104ef0d>] jump_label_update+0x49/0x98
>
> Looks like this code had jump labels enabled. Do you have a dump where
> they are not enabled?

No. Good find - and the timeline agrees too, these crashes started triggering when i
pulled jump labels from you.

Thanks,

Ingo
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