Re: perf samples too long without perf running (?!?)

From: Mike Galbraith
Date: Sat Mar 08 2014 - 02:52:01 EST


On Fri, 2014-03-07 at 17:57 -0800, Andy Lutomirski wrote:
> On recent (3.13) kernels, I'm frequently getting messages like:
>
> perf samples too long (2503 > 2500), lowering
> kernel.perf_event_max_sample_rate to 50000
>
> a few seconds to minutes after bootup. As far as I know, I'm not
> using perf. What's going on here?

14c63f17b1

I get those all the time too, just building kernels.

[ 598.583918] perf samples too long (2539 > 2500), lowering kernel.perf_event_max_sample_rate to 50000

Darn nmi_watchdog is an expensive employee. Scarier are the ones from
2ab00456ea when using perf. Firing the dog makes it all batter.

-Mike

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