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From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alex Shi <alex.shi@intel.com>,
	Suresh Siddha <suresh.b.siddha@intel.com>,
	Arjan van de Ven <arjan@linux.intel.com>,
	vincent.guittot@linaro.org, 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>,
	Thomas Gleixner <tglx@linutronix.de>,
	Paul Turner <pjt@google.com>
Subject: Re: [discussion]sched: a rough proposal to enable power saving in scheduler
Date: Wed, 15 Aug 2012 17:23:28 +0100	[thread overview]
Message-ID: <20120815162328.GB14534@srcf.ucam.org> (raw)
In-Reply-To: <1345028738.31459.82.camel@twins>

On Wed, Aug 15, 2012 at 01:05:38PM +0200, Peter Zijlstra wrote:

> Yay, ideally we'd also provide a 3rd option: auto, which simply switches
> between the two based on AC/BAT, UPS status and simple things like that.

Please, really, don't do that. Pushing power policy decisions into 
multiple bits of the stack makes things much more awkward, especially 
when the criteria you're describing are about the least interesting 
reasons for switching these states. They're most relevant on 
multi-socket systems, and the overwhelming power concern there is 
rack-level overcommit or cooling. You're going to need an external 
policy agent to handle the majority of cases people actually care about.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

  parent reply	other threads:[~2012-08-15 16:23 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 [this message]
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

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