Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966741Ab2EOUdz (ORCPT ); Tue, 15 May 2012 16:33:55 -0400 Received: from merlin.infradead.org ([205.233.59.134]:33199 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966104Ab2EOUdy convert rfc822-to-8bit (ORCPT ); Tue, 15 May 2012 16:33:54 -0400 Message-ID: <1337114026.27694.112.camel@twins> Subject: Re: Plumbers: Tweaking scheduler policy micro-conf RFP From: Peter Zijlstra To: valdis.kletnieks@vt.edu Cc: Pantelis Antoniou , Vincent Guittot , mou Chen , linux-kernel@vger.kernel.org, Ingo Molnar , torvalds@linux-foundation.org Date: Tue, 15 May 2012 22:33:46 +0200 In-Reply-To: <54348.1337113582@turing-police.cc.vt.edu> References: <833A8DB8-1AB4-45E4-8D44-14A0D782807D@gmail.com> <1337077714.27694.21.camel@twins> <9093E8BA-80E4-4113-B036-0259E5FB44F1@gmail.com> <54348.1337113582@turing-police.cc.vt.edu> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1333 Lines: 23 On Tue, 2012-05-15 at 16:26 -0400, valdis.kletnieks@vt.edu wrote: > On Tue, 15 May 2012 14:35:53 +0300, Pantelis Antoniou said: > > > Thermal management: How to distribute load to the processors in such > > a way that the temperature of the die doesn't increase too much that > > we have to either go to a lower OPP or shut down the core all-together. > > This is in direct conflict with throughput since we'd have better performance > > if we could keep the same warmed-up cpu going. > > It's not just "temperature of the die". When you have multiple aisles of 42U > racks full of servers, you often hit "must keep average total BTU load per > server below X" constraints. There's plenty of colo's that are only using 40% > of their floor space due to cooling constraints (you may be able to get the > power company to pull another megawatt of copper into the building, but then > you need to find someplace to put another megawatt worth of cooling). Yeah, I know.. sadly ACPI-4+ is a complete and utter trainwreck. But in case someone wants to fix this proper I'm willing to talk. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/