From: Arjan van de Ven <arjan@linux.intel.com>
To: Vladimir Davydov <vdavydov@parallels.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Len Brown <lenb@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] cpuidle: menu: use nr_running instead of cpuload for calculating perf mult
Date: Mon, 04 Jun 2012 06:15:09 -0700 [thread overview]
Message-ID: <4FCCB4DD.4060407@linux.intel.com> (raw)
In-Reply-To: <1338805485-10874-1-git-send-email-vdavydov@parallels.com>
On 6/4/2012 3:24 AM, Vladimir Davydov wrote:
> rq->cpuload strongly depends on cgroup hierarchy. For example, if hundreds of
> tasks are running inside cpu:/test cgroup, the sum of cpuload over all cpus
> won't exceed 1024 (by default). That makes the cpuidle menu governor take wrong
> decisions, which can negatively affect overall performance.
nr_running is the wrong answer... it is instantaneous, not longer term.
cpuidle wants a longer term, per cpu, notion of "busy", to use as proxy
for performance sensitivity.
next prev parent reply other threads:[~2012-06-04 13:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-04 10:24 [PATCH] cpuidle: menu: use nr_running instead of cpuload for calculating perf mult Vladimir Davydov
2012-06-04 10:32 ` Peter Zijlstra
2012-06-04 10:50 ` Vladimir Davydov
2012-06-04 13:13 ` Arjan van de Ven
2012-06-04 13:45 ` Peter Zijlstra
2012-06-04 13:48 ` Arjan van de Ven
2012-06-04 15:08 ` Peter Zijlstra
2012-06-04 15:14 ` Arjan van de Ven
2012-06-04 15:26 ` Peter Zijlstra
2012-06-04 15:39 ` Arjan van de Ven
2012-06-04 16:33 ` Peter Zijlstra
2012-06-04 16:53 ` Arjan van de Ven
2012-06-04 17:08 ` Vladimir Davydov
2012-06-04 17:17 ` Peter Zijlstra
2012-06-04 17:16 ` Peter Zijlstra
2012-06-04 17:25 ` Arjan van de Ven
2012-06-04 20:31 ` Peter Zijlstra
2012-06-04 20:45 ` Arjan van de Ven
2012-06-04 21:14 ` Peter Zijlstra
2012-06-04 20:40 ` Peter Zijlstra
2012-06-05 3:48 ` Mike Galbraith
2012-06-04 13:15 ` Arjan van de Ven [this message]
2012-06-04 13:19 ` Vladimir Davydov
2012-11-27 19:02 ` Vladimir Davydov
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