Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030408AbWCUOcw (ORCPT ); Tue, 21 Mar 2006 09:32:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030410AbWCUOcw (ORCPT ); Tue, 21 Mar 2006 09:32:52 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:24221 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1030408AbWCUOcv (ORCPT ); Tue, 21 Mar 2006 09:32:51 -0500 Date: Tue, 21 Mar 2006 15:30:42 +0100 From: Ingo Molnar To: Con Kolivas Cc: Mike Galbraith , Willy Tarreau , lkml , Andrew Morton , bugsplatter@gmail.com Subject: Re: interactive task starvation Message-ID: <20060321143042.GA32173@elte.hu> References: <1142592375.7895.43.camel@homer> <200603220119.50331.kernel@kolivas.org> <20060321142504.GA31258@elte.hu> <200603220128.07550.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200603220128.07550.kernel@kolivas.org> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.6 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.6 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] 0.7 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1267 Lines: 29 * Con Kolivas wrote: > On Wednesday 22 March 2006 01:25, Ingo Molnar wrote: > > * Con Kolivas wrote: > > > What you're fixing with unfairness is worth pursuing. The 'ls' issue > > > just blows my mind though for reasons I've just said. Where are the > > > magic cycles going when nothing else is running that make it take ten > > > times longer? > > > > i believe such artifacts are due to array switches not happening (due to > > the workload getting queued back to rq->active, not rq->expired), and > > 'ls' only gets a timeslice once in a while, every STARVATION_LIMIT > > times. I.e. such workloads penalize the CPU-bound 'ls' process quite > > heavily. > > With nothing else running on the machine it should still get all the > cpu no matter which array it's on though. yes. I thought you were asking why 'ls' pauses so long during the aforementioned workloads (of loadavg 7-8) - and i answered that. If you meant something else then please re-explain it to me. 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/