From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965821AbXCPSWa (ORCPT ); Fri, 16 Mar 2007 14:22:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965822AbXCPSWa (ORCPT ); Fri, 16 Mar 2007 14:22:30 -0400 Received: from cantor.suse.de ([195.135.220.2]:44683 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965821AbXCPSWa (ORCPT ); Fri, 16 Mar 2007 14:22:30 -0400 From: Andi Kleen Organization: SUSE Linux Products GmbH, Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg) To: "Guillaume Chazarain" Subject: Re: [PATCH] Add an offset in the cyc2ns computation to fix sched_clock jumps Date: Fri, 16 Mar 2007 19:22:12 +0100 User-Agent: KMail/1.9.5 Cc: "john stultz" , mathieu.desnoyers@polymtl.ca, linux-kernel@vger.kernel.org References: <3d8471ca0703161114o7ad654car60c1a6b801401149@mail.gmail.com> In-Reply-To: <3d8471ca0703161114o7ad654car60c1a6b801401149@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703161922.13450.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 16 March 2007 19:14, Guillaume Chazarain wrote: > Hello, > > The scheduling problems I reported in the thread: > http://lkml.org/lkml/2007/3/3/128 > are caused by the set_cyc2ns_scale() function called when the CPU speed changes. > Changing the scale causes a warp in the value returned by sched_clock(). I already fixed this myself in a similar way (but didn't push it out yet) But for .21 I ended up deciding on your revert patch, even though it will give bad performance. -Andi