From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754914AbZBWLMW (ORCPT ); Mon, 23 Feb 2009 06:12:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754676AbZBWLMD (ORCPT ); Mon, 23 Feb 2009 06:12:03 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:60798 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753026AbZBWLMC (ORCPT ); Mon, 23 Feb 2009 06:12:02 -0500 Message-ID: <49A283D2.8060300@cn.fujitsu.com> Date: Mon, 23 Feb 2009 19:09:06 +0800 From: Miao Xie Reply-To: miaox@cn.fujitsu.com User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Peter Zijlstra CC: Ingo Molnar , Linux-Kernel Subject: Re: [BUG] sched: fair group's bug References: <4965573B.60801@cn.fujitsu.com> <1231424195.11687.449.camel@twins> In-Reply-To: <1231424195.11687.449.camel@twins> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org on 2009-1-8 22:16 Peter Zijlstra wrote: > On Thu, 2009-01-08 at 09:30 +0800, Miao Xie wrote: >> I tested fair group scheduler on my hyper-threading x86_64 box(2 CPU * 2 HT) >> and found the deviation of the groups' CPU usage was larger than 2.6.26 >> when *offline* a CPU or do hotplug frequently. It is less than 1% On 2.6.26，but >> On current kernel, it is often greater than 4%, even than 10% by accident. > > Its not a bug -- a scheduler without smp awareness cannot be compared to > one without -- .26 just wasn't a complete group scheduler. > > At best its a regression for your particular workload. > Hi, Peter Do you wait to fix this regression? Thanks! Miao