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

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Message-ID: <20140308091331.GA282@x4>
Date:	Sat, 8 Mar 2014 10:13:31 +0100
From:	Markus Trippelsdorf <markus@...ppelsdorf.de>
To:	Mike Galbraith <umgwanakikbuti@...il.com>
Cc:	Andy Lutomirski <luto@...capital.net>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: perf samples too long without perf running (?!?)

On 2014.03.08 at 08:51 +0100, Mike Galbraith wrote:
> 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.

I have:
 echo 0 > /proc/sys/kernel/perf_cpu_time_max_percent
in my local startup script since that commit.

-- 
Markus
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