Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750806AbWCYFLO (ORCPT ); Sat, 25 Mar 2006 00:11:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750812AbWCYFLO (ORCPT ); Sat, 25 Mar 2006 00:11:14 -0500 Received: from mail.gmx.net ([213.165.64.20]:5504 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1750806AbWCYFLO (ORCPT ); Sat, 25 Mar 2006 00:11:14 -0500 X-Authenticated: #14349625 Subject: Re: [2.6.16-mm1 patch] throttling tree patches From: Mike Galbraith To: Peter Williams Cc: lkml , Ingo Molnar , Andrew Morton , Nick Piggin , Con Kolivas In-Reply-To: <442490CC.8090200@bigpond.net.au> References: <1143198208.7741.8.camel@homer> <442490CC.8090200@bigpond.net.au> Content-Type: text/plain Date: Sat, 25 Mar 2006 06:11:59 +0100 Message-Id: <1143263519.7930.21.camel@homer> Mime-Version: 1.0 X-Mailer: Evolution 2.4.0 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1443 Lines: 42 On Sat, 2006-03-25 at 11:37 +1100, Peter Williams wrote: > Mike Galbraith wrote: > > Greetings, > > > > I've broken down my throttling tree into 6 patches, which I'll send as > > replies to this start-point. > > > > Patch 1/6 > > > > Ignore timewarps caused by SMP timestamp rounding. Also, don't stamp a > > task with a computed timestamp, stamp with the already called clock. > > > > Signed-off-by: Mike Galbraith > > > > --- linux-2.6.16-mm1/kernel/sched.c.org 2006-03-23 15:01:41.000000000 +0100 > > +++ linux-2.6.16-mm1/kernel/sched.c 2006-03-23 15:02:25.000000000 +0100 > > @@ -805,6 +805,16 @@ > > unsigned long long __sleep_time = now - p->timestamp; > > unsigned long sleep_time; > > > > + /* > > + * On SMP systems, a task can go to sleep on one CPU and > > + * wake up on another. When this happens, the timestamp > > + * is rounded to the nearest tick, > > Is this true? There's no rounding that I can see. Instrumenting it looked the same as rounding down, putting now in the past was the result. > Of course, that doesn't mean that this chunk of code isn't required just > that the comment is misleading. I'm not attached to the comment. -Mike - 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/