From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755350Ab0IPOlr (ORCPT ); Thu, 16 Sep 2010 10:41:47 -0400 Received: from cantor2.suse.de ([195.135.220.15]:44445 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755287Ab0IPOlq (ORCPT ); Thu, 16 Sep 2010 10:41:46 -0400 Date: Thu, 16 Sep 2010 07:42:16 -0700 From: Greg KH To: Mike Galbraith Cc: Yinghai Lu , Ingo Molnar , Peter Zijlstra , "linux-kernel@vger.kernel.org" , John Wright Subject: Re: 2.6.32.y stable kernel regression with taskset Message-ID: <20100916144216.GA4794@suse.de> References: <4C9114A6.6040500@oracle.com> <1284608712.7403.10.camel@marge.simson.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1284608712.7403.10.camel@marge.simson.net> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 16, 2010 at 05:45:12AM +0200, Mike Galbraith wrote: > On Wed, 2010-09-15 at 11:47 -0700, Yinghai Lu wrote: > > found problem with cpuscaling test. > > > > Under 2.6.32.21 Userspace gov > > min freq load test time is nearly the same as max freq load test time around ~16 seconds > > > > under 2.6.18-194 > > min freq load test time is ~40 seconds > > max freq load test time is ~ 17 seconds > > > > the test is > > 1. set governor for one cpu to userspace > > 2. set freq to min for that cpu > > 3. using taskset to put load test only on that cpu, and get the time for load test. > > > > so that mean taskset did not put load test on cpu that we want. and other cpu still have ondemand governor and load test get done much faster > > > > git bisect report: > > > > c6fc81afa2d7ef2f775e48672693d8a0a8a7325d is the first bad commit > > commit c6fc81afa2d7ef2f775e48672693d8a0a8a7325d > > Author: John Wright > > Date: Tue Apr 13 16:55:37 2010 -0600 > > > > sched: Fix a race between ttwu() and migrate_task() > > Known issue. There's a sched series for 32-stable in the pipeline. Yes, sorry, I'm working my way through to them, hope to have them finished and applied soon. thanks, greg k-h