From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755889AbXHBHUP (ORCPT ); Thu, 2 Aug 2007 03:20:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752953AbXHBHUB (ORCPT ); Thu, 2 Aug 2007 03:20:01 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:34344 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752677AbXHBHUA (ORCPT ); Thu, 2 Aug 2007 03:20:00 -0400 Date: Thu, 2 Aug 2007 09:19:56 +0200 From: Ingo Molnar To: Nick Piggin Cc: Linus Torvalds , Andrew Morton , Linux Kernel Mailing List Subject: Re: lmbench ctxsw regression with CFS Message-ID: <20070802071956.GA23300@elte.hu> References: <20070802021525.GC15595@wotan.suse.de> <20070802024132.GD15595@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070802024132.GD15595@wotan.suse.de> User-Agent: Mutt/1.5.14 (2007-02-12) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -1.0 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 * Nick Piggin wrote: > > One thing to check out is whether the lmbench numbers are "correct". > > Especially on SMP systems, the lmbench numbers are actually *best* > > when the two processes run on the same CPU, even though that's not > > really at all the best scheduling - it's just that it artificially > > improves lmbench numbers because of the close cache affinity for the > > pipe data structures. > > Yes, I bound them to a single core. could you send me the .config you used? Ingo