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Date: Sat, 6 Jul 2013 09:24:08 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Dave Jones <davej@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        Peter Anvin <hpa@zytor.com>, Peter Zijlstra <peterz@infradead.org>
Subject: Re: Yet more softlockups.
Message-ID: <20130706072408.GA14865@gmail.com>
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* Dave Jones <davej@redhat.com> 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.

Thanks,

	Ingo