Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754292AbXEBKlW (ORCPT ); Wed, 2 May 2007 06:41:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754385AbXEBKlW (ORCPT ); Wed, 2 May 2007 06:41:22 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:58327 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750917AbXEBKlV (ORCPT ); Wed, 2 May 2007 06:41:21 -0400 Date: Wed, 2 May 2007 12:40:38 +0200 From: Ingo Molnar To: Mike Galbraith Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Con Kolivas , Nick Piggin , Arjan van de Ven , Peter Williams , Thomas Gleixner , caglar@pardus.org.tr, Willy Tarreau , Gene Heskett , Mark Lord , Zach Carter , buddabrod , Balbir Singh Subject: Re: [patch] CFS scheduler, -v8 Message-ID: <20070502104038.GA11057@elte.hu> References: <20070501212223.GA29867@elte.hu> <1178092794.8926.43.camel@Homer.simpson.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1178092794.8926.43.camel@Homer.simpson.net> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2265 Lines: 51 * Mike Galbraith wrote: > On Tue, 2007-05-01 at 23:22 +0200, Ingo Molnar wrote: > > - interactivity: precise load calculation and load smoothing > > This seems to help quite a bit. great :) > (5 second top sample) > > 2636 root 15 -5 19148 15m 5324 R 73 1.5 1:42.29 0 amarok_libvisua > 5440 root 20 0 320m 36m 8388 S 18 3.6 3:28.55 1 Xorg > 4621 root 20 0 22776 18m 4168 R 12 1.8 0:00.63 1 cc1 > 4616 root 20 0 19456 13m 2200 R 9 1.3 0:00.43 0 cc1 > > I no longer have to renice both X and Gforce to achieve a perfect > display when they are sharing my box with a make -j2. X is displaying > everything it's being fed beautifully with no help. I have to renice > Gforce (amarok_libvisual), but given it's very heavy CPU usage, that > seems perfectly fine. ah! Besides OpenGL behavior and app startup performance i didnt originally have Xorg in mind with this change, but thinking about it, precise load calculations and load smoothing does have a positive effect on 'coupled' workloads where under the previous variant of CFS's load calculation one task component of the workload could become 'invisible' to another task and hence cause macro-scale scheduling artifacts not expected by humans. With smoothing these are dealt with more consistently. Xorg can be a quite strongly coupled workload. > No regressions noticed so far. Box is _very_ responsive under load, > seemingly even more so than with previous releases. That is purely > subjective, but the first impression was very distinct. yeah, make -jN workloads (and any mixture of non-identical scheduling patterns, which most real workloads consist of) should be handled more consistently too by -v8. so your workload (and Gene's workload) were the ones in fact that i had hoped not to _hurt_ with -v8 (neither of you being the hardcore gamer type ;), and in reality -v8 ended up helping them too. These sorts of side-effects are always welcome ;-) Ingo - 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/