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From: Alex Shi <alex.shi@intel.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Suresh Siddha <suresh.b.siddha@intel.com>,
	Arjan van de Ven <arjan@linux.intel.com>,
	svaidy@linux.vnet.ibm.com, Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [discussion]sched: a rough proposal to enable power saving in scheduler
Date: Tue, 21 Aug 2012 09:05:26 +0800	[thread overview]
Message-ID: <5032DED6.9090709@intel.com> (raw)
In-Reply-To: <CAKfTPtA98e8GYGwaj4k9y_-4h3e3UOguqJmdkqF0v3Y+5tPRpw@mail.gmail.com>

On 08/20/2012 11:47 PM, Vincent Guittot wrote:

> On 16 August 2012 07:03, Alex Shi <alex.shi@intel.com> wrote:
>> On 08/16/2012 12:19 AM, Matthew Garrett wrote:
>>
>>> On Mon, Aug 13, 2012 at 08:21:00PM +0800, Alex Shi wrote:
>>>
>>>> power aware scheduling), this proposal will adopt the
>>>> sched_balance_policy concept and use 2 kind of policy: performance, power.
>>>
>>> Are there workloads in which "power" might provide more performance than
>>> "performance"? If so, don't use these terms.
>>>
>>
>>
>> Power scheme should no chance has better performance in design.
> 
> A side effect of packing small tasks on one core is that you always
> use the core with the lowest C-state which will minimize the wake up
> latency so you can sometime get better results than performance mode
> which will try to use a other core in another cluster which will take
> more time to wake up that waiting for the end of the current task.
> 


Sure. some scenario packing tasks into smaller domain will bring
performance benefit.

      reply	other threads:[~2012-08-21  1:06 UTC|newest]

Thread overview: 90+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-13 12:21 [discussion]sched: a rough proposal to enable power saving in scheduler Alex Shi
2012-08-14  7:35 ` Alex Shi
2012-08-15  8:23   ` Peter Zijlstra
2012-08-15 11:05 ` Peter Zijlstra
2012-08-15 13:15   ` Borislav Petkov
2012-08-15 14:43     ` Peter Zijlstra
2012-08-16  3:22       ` Alex Shi
2012-08-16  3:09     ` Alex Shi
2012-08-15 13:45   ` Arjan van de Ven
2012-08-15 14:39     ` Peter Zijlstra
2012-08-15 14:43       ` Arjan van de Ven
2012-08-15 15:04         ` Peter Zijlstra
2012-08-15 17:59           ` Arjan van de Ven
2012-08-20  8:06             ` Ingo Molnar
2012-08-20  8:26               ` Peter Zijlstra
2012-08-20 13:26               ` Arjan van de Ven
2012-08-20 18:16               ` Matthew Garrett
2012-08-21  9:42                 ` Ingo Molnar
2012-08-21 11:39                   ` Matthew Garrett
2012-08-21 15:19                     ` Ingo Molnar
2012-08-21 15:21                       ` Arjan van de Ven
2012-08-21 15:28                       ` Matthew Garrett
2012-08-21 15:59                         ` Ingo Molnar
2012-08-21 16:13                           ` Matthew Garrett
2012-08-21 18:23                             ` Ingo Molnar
2012-08-21 18:34                               ` Matthew Garrett
2012-08-22  9:10                                 ` Ingo Molnar
2012-08-22 11:35                                   ` Matthew Garrett
2012-08-23  8:19                                   ` Alex Shi
2012-08-21 18:52                               ` Alan Cox
2012-08-22  9:03                                 ` Ingo Molnar
2012-08-22 11:00                                   ` Alan Cox
2012-08-22 11:33                                     ` Ingo Molnar
2012-08-22 12:58                                       ` Alan Cox
2012-08-21 16:02                       ` Alan Cox
2012-08-22  5:41                         ` Mike Galbraith
2012-08-22 13:02                           ` Arjan van de Ven
2012-08-22 13:09                             ` Mike Galbraith
2012-08-22 13:21                             ` Matthew Garrett
2012-08-22 13:23                               ` Arjan van de Ven
2012-08-16  1:14         ` Rik van Riel
2012-08-16  1:17           ` Arjan van de Ven
2012-08-16  1:21           ` Arjan van de Ven
2012-08-15 14:19   ` Arjan van de Ven
2012-08-15 14:44     ` Peter Zijlstra
2012-08-15 14:47       ` Thomas Gleixner
2012-08-15 16:23   ` Matthew Garrett
2012-08-15 16:34   ` Matthew Garrett
2012-08-15 18:02     ` Arjan van de Ven
2012-08-17  8:59       ` Paul Turner
2012-08-16  3:07   ` Alex Shi
2012-08-16  6:53   ` preeti
2012-08-16  9:58     ` Alex Shi
2012-08-16 12:45     ` Shilimkar, Santosh
2012-08-16 14:01     ` Arjan van de Ven
2012-08-16 18:45       ` Rik van Riel
2012-08-16 19:20         ` Arjan van de Ven
2012-08-17  1:29       ` Alex Shi
2012-08-17 18:41       ` Matthew Garrett
2012-08-17 18:44         ` Arjan van de Ven
2012-08-17 18:47           ` Matthew Garrett
2012-08-17 19:45             ` Chris Friesen
2012-08-17 19:50               ` Matthew Garrett
2012-08-17 20:16                 ` Chris Friesen
2012-08-18 14:33                   ` Luming Yu
2012-08-18 14:52                     ` Arjan van de Ven
2012-08-16 14:31   ` Morten Rasmussen
2012-08-19 10:12     ` Juri Lelli
2012-08-17  8:43   ` Paul Turner
2012-08-20 15:55     ` Vincent Guittot
2012-08-20 15:36   ` Vincent Guittot
2012-08-21  0:58     ` Alex Shi
2012-08-21 11:05       ` Vincent Guittot
2012-08-15 14:24 ` Rakib Mullick
2012-08-15 14:55   ` Peter Zijlstra
2012-08-15 22:58     ` Rakib Mullick
2012-08-16  5:26     ` Alex Shi
2012-08-16  4:57   ` Alex Shi
2012-08-16  8:05     ` Rakib Mullick
2012-08-15 16:19 ` Matthew Garrett
2012-08-16  5:03   ` Alex Shi
2012-08-16  5:31     ` Matthew Garrett
2012-08-16  5:39       ` Alex Shi
2012-08-16  5:45         ` Matthew Garrett
2012-08-16 13:57     ` Arjan van de Ven
2012-08-20 15:47       ` Christoph Lameter
2012-08-20 15:52         ` Matthew Garrett
2012-08-20 19:22           ` Christoph Lameter
2012-08-20 15:47     ` Vincent Guittot
2012-08-21  1:05       ` Alex Shi [this message]

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