Messages in this thread | | | Date | Mon, 13 May 2013 22:01:12 +0200 (CEST) | From | Jiri Kosina <> | Subject | Re: NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule |
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On Mon, 13 May 2013, Thomas Gleixner wrote:
> > > --- a/kernel/time/tick-sched.c > > > +++ b/kernel/time/tick-sched.c > > > @@ -650,6 +650,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, > > > > > > ts->last_tick = hrtimer_get_expires(&ts->sched_timer); > > > ts->tick_stopped = 1; > > > + WARN_ON_ONCE(!cpu_online(cpu)); > > So that warning triggers. > > > WARNING: at kernel/time/tick-sched.c:653 tick_nohz_stop_sched_tick+0x38e/0x3a0() > > The pre full dyntick idle code bailed out when a cpu was offline. The > new fangled can_stop_idle_tick() function dropped that. > > Does the patch below fix the issue? > > Thanks, > > tglx > > diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c > index bc67d42..00a9a97 100644 > --- a/kernel/time/tick-sched.c > +++ b/kernel/time/tick-sched.c > @@ -717,6 +717,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) > if (unlikely(!cpu_online(cpu))) { > if (cpu == tick_do_timer_cpu) > tick_do_timer_cpu = TICK_DO_TIMER_NONE; > + return false; > } > > if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
The warning is gone, so it definitely looks like you found a culprit, Thomas, thanks.
But I am not going to provide my Tested-by: yet, as one of the four suspend-resume cycles I have done during testing of this patch ended up with segfaults when trying to start any userspace binary after resume (i.e. clear memory corruption). The remaining three suspend-resume cycles were fine.
Will be looking into this a little bit more.
-- Jiri Kosina SUSE Labs
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