From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031140AbXDYUzi (ORCPT ); Wed, 25 Apr 2007 16:55:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031143AbXDYUzi (ORCPT ); Wed, 25 Apr 2007 16:55:38 -0400 Received: from nz-out-0506.google.com ([64.233.162.227]:14531 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031140AbXDYUzh (ORCPT ); Wed, 25 Apr 2007 16:55:37 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=lTpIvO3tZnzxWpbYBqJRGtJduy1pfwSypxoUaT2zgrl8tza5CTQDIGdSh8XV9FENBSG2Lfu7oR0Ur75kmGBuXz5ph/x2NOyYz1K9zXqM/eL11Hkmi19DwB3xF97zGxyYoO5oycP/K9/KaNjHJyT0G7ZKKGYvMO0PQe3qUpHQY60= Message-ID: <6bffcb0e0704251355r6de26273s47ba5c857ed0f129@mail.gmail.com> Date: Wed, 25 Apr 2007 22:55:36 +0200 From: "Michal Piotrowski" To: "Andi Kleen" Subject: Re: mm snapshot broken-out-2007-04-25-02-49.tar.gz uploaded Cc: "Jeremy Fitzhardinge" , "Andrew Morton" , "Ingo Molnar" , LKML In-Reply-To: <200704252248.03243.ak@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200704250952.l3P9qIHh032233@shell0.pdx.osdl.net> <462FB8E6.9070501@googlemail.com> <462FBD44.2040103@goop.org> <200704252248.03243.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 25/04/07, Andi Kleen wrote: > On Wednesday 25 April 2007 22:42:44 Jeremy Fitzhardinge wrote: > > Michal Piotrowski wrote: > > > Timing information is broken > > > > > > > This looks like Andi's sched_clock stuff hitting: it returns an > > inherently per-cpu result, so using it for printk timestamps isn't very > > useful. > > It should actually roughly work. There can be some drift, but there shouldn't > be that much error. All CPUs should tick at roughly the same rate because > it's scaled to nanoseconds > > If the drift is a big issue it would also be possible to resync every minute > or so, but I haven't implemented that. > > There will be always some minor monotonicities because it won't try > to stop the CPU from reordering instructions. > > I don't know why it is that off in your case. Maybe because it's P4 HT? Regards, Michal -- Michal K. K. Piotrowski LTG - Linux Testers Group (PL) (http://www.stardust.webpages.pl/ltg/) LTG - Linux Testers Group (EN) (http://www.stardust.webpages.pl/linux_testers_group_en/)