Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992996AbXEBKG6 (ORCPT ); Wed, 2 May 2007 06:06:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992963AbXEBKG6 (ORCPT ); Wed, 2 May 2007 06:06:58 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:60033 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992996AbXEBKG5 (ORCPT ); Wed, 2 May 2007 06:06:57 -0400 Date: Wed, 2 May 2007 12:05:45 +0200 From: Ingo Molnar To: Balbir Singh Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Con Kolivas , Nick Piggin , Mike Galbraith , Arjan van de Ven , Peter Williams , Thomas Gleixner , caglar@pardus.org.tr, Willy Tarreau , Gene Heskett , Mark Lord , Zach Carter , buddabrod Subject: Re: [patch] CFS scheduler, -v8 Message-ID: <20070502100545.GA6857@elte.hu> References: <20070501212223.GA29867@elte.hu> <463854F3.3020403@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <463854F3.3020403@linux.vnet.ibm.com> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 984 Lines: 22 * Balbir Singh wrote: > With -v7 I would run the n/n+1 test. Basically on a system with n > cpus, I would run n+1 tasks and see how their load is distributed. I > usually find that the last two tasks would get stuck on one CPU on the > system and would get half the cpu time as their other peers. I think > this issue has been around for long even before CFS. But while I was > investigating that, I found that with -v8, all the n+1 tasks are stuck > on the same cpu. i believe this problem is specific to powerpc - load is distributed fine on i686/x86_64 and your sched_debug shows a cpu_load[0] == 0 on CPU#2 which is 'impossible'. (I sent a few suggestions off-Cc about how to debug this.) Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/