From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759135AbXGCHP2 (ORCPT ); Tue, 3 Jul 2007 03:15:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755308AbXGCHPV (ORCPT ); Tue, 3 Jul 2007 03:15:21 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:56711 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752579AbXGCHPU (ORCPT ); Tue, 3 Jul 2007 03:15:20 -0400 Date: Tue, 3 Jul 2007 09:15:12 +0200 From: Ingo Molnar To: Vegard Nossum Cc: linux-kernel@vger.kernel.org Subject: Re: [patch] CFS scheduler, -v18 Message-ID: <20070703071512.GA29984@elte.hu> References: <20070622220202.GA16872@elte.hu> <19f34abd0707020444r47221944tf7f33b2a0d17c367@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <19f34abd0707020444r47221944tf7f33b2a0d17c367@mail.gmail.com> 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 -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 * Vegard Nossum wrote: > I'd also like to point out that Folding@Home seems to draw more CPU > than it should. Or, at least, in top, it shows up as using 50% CPU > even though other processes are demanding as much as they can get. The > FAH program should be running with idle priority. I expect it to fall > to near 0% when other programs are running at full speed, but it keeps > trotting along. And I am pretty sure that this is not due to SMP/HT (I > made sure to utilize both CPUs). your FAH processes are running with nice +19 - that should be enough to throttle them. With v18 you can also mark it SCHED_IDLE: schedtool -D $$ # mark the shell idle SCHED_IDLE gets inherited by child tasks so if you mark the shell that starts up FEH as SCHED_IDLE, all FEH threads should be SCHED_IDLE too. (or you can start it up via schedtool -D -e ... ) does it still get more CPU time than you'd expect it to get? A reniced or SCHED_IDLE task will 'fill in' any idle time that it senses, so in itself it's not an anomaly if a task gets 50% and FEH fills in the remaining 50%. Does it still get CPU time if you start two CPU hogs: for (( N=0; N < 2; N++ )); do ( while :; do :; done ) & done ? If yes, that would be an anomaly. > Otherwise, I am satisfied with the performance of CFS. Especially the > desktop is noticably smoother. Thanks! great! :-) Ingo