From: Mike Galbraith <bitbucket@online.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Dave Chiluk <chiluk@canonical.com>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: Scheduler accounting inflated for io bound processes.
Date: Wed, 26 Jun 2013 18:01:48 +0200 [thread overview]
Message-ID: <1372262508.8776.83.camel@marge.simpson.net> (raw)
In-Reply-To: <20130626155048.GA7399@gmail.com>
On Wed, 2013-06-26 at 17:50 +0200, Ingo Molnar wrote:
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Wed, Jun 26, 2013 at 11:37:13AM +0200, Ingo Molnar wrote:
> > > Would be very nice to randomize the sampling rate, by randomizing the
> > > intervals within a 1% range or so - perf tooling will probably recognize
> > > the different weights.
> >
> > You're suggesting adding noise to the regular kernel tick?
>
> No, to the perf interval (which I assumed Mike was using to profile this?)
Yeah, perf top -F 250 exhibits the same inaccuracy as 250 Hz tick cpu
accounting. (sufficient sample jitter should cure it, but I think I'd
prefer to just live with it)
-Mike
next prev parent reply other threads:[~2013-06-26 16:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 19:46 Dave Chiluk
2013-06-25 16:01 ` Mike Galbraith
2013-06-25 17:48 ` Mike Galbraith
2013-06-26 9:37 ` Ingo Molnar
2013-06-26 10:42 ` Peter Zijlstra
2013-06-26 15:50 ` Ingo Molnar
2013-06-26 16:01 ` Mike Galbraith [this message]
2013-06-26 16:04 ` David Ahern
2013-06-26 16:10 ` Ingo Molnar
2013-06-26 16:13 ` David Ahern
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