From: Arjan van de Ven <arjan@infradead.org>
To: Shawn Bohrer <shawn.bohrer@gmail.com>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: High scheduler wake up times
Date: Sat, 30 Jan 2010 15:56:40 -0800 [thread overview]
Message-ID: <20100130155640.62ce3104@infradead.org> (raw)
In-Reply-To: <20100130234551.GA27390@mediacenter.gateway.2wire.net>
On Sat, 30 Jan 2010 17:45:51 -0600
Shawn Bohrer <shawn.bohrer@gmail.com> wrote:
> Hello,
>
> Currently we have a workload that depends on around 50 processes that
> wake up 1000 times a second do a small amount of work and go back to
> sleep. This works great on RHEL 5 (2.6.18-164.6.1.el5), but on recent
> kernels we are unable to achieve 1000 iterations per second. Using
> the simple test application below on RHEL 5 2.6.18-164.6.1.el5 I can
> run 500 of these processes on and still achieve 999.99 iterations per
> second. Running just 10 of these processes on the same machine with
> 2.6.32.6 produces results like:
>
> ...
> Iterations Per Sec: 905.659667
> Iterations Per Sec: 805.099068
> Iterations Per Sec: 925.195578
> Iterations Per Sec: 759.310773
> Iterations Per Sec: 702.849261
> Iterations Per Sec: 782.157292
> Iterations Per Sec: 917.138031
> Iterations Per Sec: 834.770391
> Iterations Per Sec: 850.543755
> ...
>
> I've tried playing with some of the cfs tunables in /proc/sys/kernel/
> without success. Are there any suggestions on how to achieve the
> results we are looking for using a recent kernel?
I'll play a bit, but I wonder idly what kind of machine this is on ?
(number and types of cpus)
next prev parent reply other threads:[~2010-01-30 23:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-30 23:45 Shawn Bohrer
2010-01-30 23:56 ` Arjan van de Ven [this message]
2010-01-31 0:29 ` Shawn Bohrer
2010-01-31 0:02 ` Arjan van de Ven
2010-01-31 0:11 ` Arjan van de Ven
2010-01-31 0:35 ` Shawn Bohrer
2010-01-31 0:46 ` Shawn Bohrer
2010-01-31 0:47 ` Arjan van de Ven
2010-01-31 3:47 ` Shawn Bohrer
2010-01-31 18:28 ` Arjan van de Ven
2010-01-31 20:50 ` Shawn Bohrer
2010-02-01 8:51 ` Peter Zijlstra
2010-02-01 19:37 ` Shawn Bohrer
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