From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756008Ab0IPTgO (ORCPT ); Thu, 16 Sep 2010 15:36:14 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:28494 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752517Ab0IPTgM (ORCPT ); Thu, 16 Sep 2010 15:36:12 -0400 Message-ID: <4C92719E.5070103@oracle.com> Date: Thu, 16 Sep 2010 12:35:58 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.11) Gecko/20100714 SUSE/3.0.6 Thunderbird/3.0.6 MIME-Version: 1.0 To: Greg KH CC: Mike Galbraith , Ingo Molnar , Peter Zijlstra , "linux-kernel@vger.kernel.org" , John Wright Subject: Re: 2.6.32.y stable kernel regression with taskset References: <4C9114A6.6040500@oracle.com> <1284608712.7403.10.camel@marge.simson.net> <20100916144216.GA4794@suse.de> In-Reply-To: <20100916144216.GA4794@suse.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/16/2010 07:42 AM, Greg KH wrote: > 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. > why not just revert that patch? wonder if SLES11SP1 or RHEL 6 have this patch or not. Yinghai