From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753696AbXLEVQK (ORCPT ); Wed, 5 Dec 2007 16:16:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751970AbXLEVP6 (ORCPT ); Wed, 5 Dec 2007 16:15:58 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:46020 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752015AbXLEVP5 (ORCPT ); Wed, 5 Dec 2007 16:15:57 -0500 X-Greylist: delayed 2299 seconds by postgrey-1.27 at vger.kernel.org; Wed, 05 Dec 2007 16:15:57 EST Subject: Re: Scheduler behaviour From: Peter Zijlstra To: Holger.Wolf@de.ibm.com Cc: mingo@elte.hu, schwidefsky@de.ibm.com, linux-kernel@vger.kernel.org In-Reply-To: <475706E2.50805@linux.vnet.ibm.com> References: <475706E2.50805@linux.vnet.ibm.com> Content-Type: text/plain Date: Wed, 05 Dec 2007 22:15:02 +0100 Message-Id: <1196889302.6353.29.camel@lappy> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2007-12-05 at 21:15 +0100, Holger Wolf wrote: > We discovered performance degradation with dbench when using kernel 2.6.23 compared to kernel 2.6.22. We've fixed a lot of regressions and made a lot of other changes to the scheduler since .23. Could you please try the backport of the latest scheduler on top of .23 to see if any of our recent work solved your problem? (using a backport against .23 or even .22 allows you to test just the scheduler changes in isolation) http://people.redhat.com/mingo/cfs-scheduler/sched-cfs-v2.6.22.13-v24.patch http://people.redhat.com/mingo/cfs-scheduler/sched-cfs-v2.6.23.9-v24.patch Also, it could be dbench is one of those benchmarks that favours unfairness, I seem to remember so.. still we should not regress too much without a very good reason.