Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755527AbXH1ICt (ORCPT ); Tue, 28 Aug 2007 04:02:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751996AbXH1ICe (ORCPT ); Tue, 28 Aug 2007 04:02:34 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:35043 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752029AbXH1ICb (ORCPT ); Tue, 28 Aug 2007 04:02:31 -0400 Date: Tue, 28 Aug 2007 10:02:18 +0200 From: Ingo Molnar To: Xavier Bestel Cc: Al Boldi , Peter Zijlstra , Mike Galbraith , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: CFS review Message-ID: <20070828080218.GA12247@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1188287015.1131.232.camel@frg-rhel40-em64t-04> 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=3.0.3 -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: 1487 Lines: 32 * 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. ] but i agree that on a non-accelerated X setup glxgears is not really meaningful. It can have similar "spam the X server" effects as xperf. 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/