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From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Vladimir Davydov <vdavydov@parallels.com>
Cc: Ingo Molnar <mingo@elte.hu>,
	Arjan van de Ven <arjan@linux.intel.com>,
	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 12:32:47 +0200	[thread overview]
Message-ID: <1338805967.28282.12.camel@twins> (raw)
In-Reply-To: <1338805485-10874-1-git-send-email-vdavydov@parallels.com>

On Mon, 2012-06-04 at 14:24 +0400, 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.
> 
> To cope this, use nr_running last seen in __update_cpu_load() instead of
> cpuload for calculating performance multiplier.

What is cpuidle trying to do?

  reply	other threads:[~2012-06-04 10:33 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 [this message]
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
2012-06-04 13:19   ` Vladimir Davydov
2012-11-27 19:02 ` Vladimir Davydov

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