Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759896AbXHCGba (ORCPT ); Fri, 3 Aug 2007 02:31:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755901AbXHCGbX (ORCPT ); Fri, 3 Aug 2007 02:31:23 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:50931 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755783AbXHCGbW (ORCPT ); Fri, 3 Aug 2007 02:31:22 -0400 Date: Fri, 3 Aug 2007 08:31:04 +0200 From: Ingo Molnar To: Kasper Sandberg Cc: Peter Zijlstra , Linus Torvalds , Linux Kernel Mailing List , ck@vds.kolivas.org Subject: Re: SD still better than CFS for 3d ?(was Re: 2.6.23-rc1) Message-ID: <20070803063104.GA24598@elte.hu> References: <1185536610.502.8.camel@localhost> <20070729170641.GA26220@elte.hu> <1185839164.27166.7.camel@localhost> <1185863461.3092.4.camel@twins> <20070731085713.GA15136@elte.hu> <1186011827.2482.1.camel@localhost> <20070802121018.GA11900@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070802121018.GA11900@elte.hu> 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: 1838 Lines: 39 * Ingo Molnar wrote: > do you have any filesystem that is not reiserfs? If yes, could you, as > a test, check whether file activities on _that_ file system still > cause these lags, or is the lag purely connected to the reiser3 > filesystem? i still have little debug info from you to start from: no cfs-debug-info.sh output of the problematic workload and no kernel .config. i tried to reproduce your problems based on your existing description: i did a lot of reiser3 testing yesterday and i also wrote a 'BKL latency simulator' (which does a faux lock_kernel() + unlock_kernel() so that the testcode runs into the BKL all the time) - but still this had no visible effect on desktop latencies so either i have some subtle difference in my setup or this aspect of your workload is not the cause of the smoothness problem. could please give us more debug info and try to simplify the "bad" case down to something that can be pinpointed and triggered more exactly? Do you see any particular 'ruckle' in the 3D game when you see a smoothness problem? Anything that we could clearly label as 'anomalous latency' in a tracer output? (in that case i'll send you tracing patches so that we can catch a trace of that 'hickup') You said the imap stuff could be causing the smoothness problem: as a debugging thing could you try to renice all the imap activities (imap daemon / mailer) to nice +19, does that make the game magically smooth again? If yes then this is an indicator that the problem is interaction between the game and the imap activities. 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/