Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760316AbXH2Dmu (ORCPT ); Tue, 28 Aug 2007 23:42:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757726AbXH2Dmj (ORCPT ); Tue, 28 Aug 2007 23:42:39 -0400 Received: from mail.tmr.com ([64.65.253.246]:34883 "EHLO gaimboi.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759197AbXH2Dmi (ORCPT ); Tue, 28 Aug 2007 23:42:38 -0400 Message-ID: <46D4EB2E.9000300@tmr.com> Date: Tue, 28 Aug 2007 23:42:38 -0400 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061105 SeaMonkey/1.0.6 MIME-Version: 1.0 To: Ingo Molnar CC: Al Boldi , Peter Zijlstra , Mike Galbraith , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org Subject: Re: CFS review References: <200708111344.42934.a1426z@gawab.com> <200708220127.30698.a1426z@gawab.com> <20070824134510.GA21382@elte.hu> <200708260127.32238.a1426z@gawab.com> <20070825231525.GA334@elte.hu> In-Reply-To: <20070825231525.GA334@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1679 Lines: 50 Ingo Molnar wrote: > * Al Boldi wrote: > >>> ok. I think i might finally have found the bug causing this. Could >>> you try the fix below, does your webserver thread-startup test work >>> any better? >> It seems to help somewhat, but the problem is still visible. Even >> v20.3 on 2.6.22.5 didn't help. >> >> It does look related to ia-boosting, so I turned off __update_curr >> like Roman mentioned, which had an enormous smoothing effect, but then >> nice levels completely break down and lockup the system. > > you can turn sleeper-fairness off via: > > echo 28 > /proc/sys/kernel/sched_features > > another thing to try would be: > > echo 12 > /proc/sys/kernel/sched_features 14, and drop the granularity to 500000. > > (that's the new-task penalty turned off.) > > Another thing to try would be to edit this: > > if (sysctl_sched_features & SCHED_FEAT_START_DEBIT) > p->se.wait_runtime = -(sched_granularity(cfs_rq) / 2); > > to: > > if (sysctl_sched_features & SCHED_FEAT_START_DEBIT) > p->se.wait_runtime = -(sched_granularity(cfs_rq); > > and could you also check 20.4 on 2.6.22.5 perhaps, or very latest -git? > (Peter has experienced smaller spikes with that.) > > Ingo -- Bill Davidsen "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot - 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/