Re: Yet more softlockups.

From: Dave Jones
Date: Wed Jul 10 2013 - 11:14:14 EST


On Sat, Jul 06, 2013 at 09:24:08AM +0200, Ingo Molnar wrote:
>
> * Dave Jones <davej@xxxxxxxxxx> wrote:
>
> > On Fri, Jul 05, 2013 at 05:15:07PM +0200, Thomas Gleixner wrote:
> > > On Fri, 5 Jul 2013, Dave Jones wrote:
> > >
> > > > BUG: soft lockup - CPU#3 stuck for 23s! [trinity-child1:14565]
> > > > perf samples too long (2519 > 2500), lowering kernel.perf_event_max_sample_rate to 50000
> > > > INFO: NMI handler (perf_event_nmi_handler) took too long to run: 238147.002 msecs
> > >
> > > So we see a softlockup of 23 seconds and the perf_event_nmi_handler
> > > claims it did run 23.8 seconds.
> > >
> > > Are there more instances of NMI handler messages ?
> >
> > [ 2552.006181] perf samples too long (2511 > 2500), lowering kernel.perf_event_max_sample_rate to 50000
> > [ 2552.008680] INFO: NMI handler (perf_event_nmi_handler) took too long to run: 500392.002 msecs
>
> Dave, could you pull in the latest perf fixes at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/urgent
>
> In particular this:
>
> e5302920da9e perf: Fix interrupt handler timing harness
>
> could make a difference - if your tests somehow end up activating perf.

Something is really fucked up in the kernel side of perf.
I get this right after booting..

[ 114.516619] perf samples too long (4262 > 2500), lowering kernel.perf_event_max_sample_rate to 50000

That's before I even get a chance to log in, so I'm pretty sure perf isn't even being run.

And this is just booting up my desktop, not fuzzing.

Dave

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