Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763278AbXH1T4V (ORCPT ); Tue, 28 Aug 2007 15:56:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757326AbXH1Tzq (ORCPT ); Tue, 28 Aug 2007 15:55:46 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:55568 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760891AbXH1Tzp (ORCPT ); Tue, 28 Aug 2007 15:55:45 -0400 Date: Tue, 28 Aug 2007 21:55:25 +0200 From: Ingo Molnar To: Willy Tarreau Cc: Xavier Bestel , Al Boldi , Peter Zijlstra , Mike Galbraith , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: CFS review Message-ID: <20070828195525.GB30537@elte.hu> References: <200708111344.42934.a1426z@gawab.com> <200708271746.47685.a1426z@gawab.com> <20070827204116.GA12495@elte.hu> <200708280737.53439.a1426z@gawab.com> <1188287015.1131.232.camel@frg-rhel40-em64t-04> <20070828080218.GA12247@elte.hu> <20070828191924.GT6002@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070828191924.GT6002@1wt.eu> User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.0 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: 1971 Lines: 43 * Willy Tarreau wrote: > On Tue, Aug 28, 2007 at 10:02:18AM +0200, Ingo Molnar wrote: > > > > * Xavier Bestel wrote: > > > > > Are you sure they are stalled ? What you may have is simple gears > > > running at a multiple of your screen refresh rate, so they only appear > > > stalled. > > > > > > Plus, as said Linus, you're not really testing the kernel scheduler. > > > gears is really bad benchmark, it should die. > > > > i like glxgears as long as it runs on _real_ 3D hardware, because there > > it has minimal interaction with X and so it's an excellent visual test > > about consistency of scheduling. You can immediately see (literally) > > scheduling hickups down to a millisecond range (!). In this sense, if > > done and interpreted carefully, glxgears gives more feedback than many > > audio tests. (audio latency problems are audible, but on most sound hw > > it takes quite a bit of latency to produce an xrun.) So basically > > glxgears is the "early warning system" that tells us about the potential > > for xruns earlier than an xrun would happen for real. > > > > [ of course you can also run all the other tools to get numeric results, > > but glxgears is nice in that it gives immediate visual feedback. ] > > Al could also test ocbench, which brings visual feedback without > harnessing the X server : http://linux.1wt.eu/sched/ > > I packaged it exactly for this problem and it has already helped. It > uses X after each loop, so if you run it with large run time, X is > nearly not sollicitated. yeah, and ocbench is one of my favorite cross-task-fairness tests - i dont release a CFS patch without checking it with ocbench first :-) 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/