From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752474AbZIHXVB (ORCPT ); Tue, 8 Sep 2009 19:21:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751708AbZIHXVA (ORCPT ); Tue, 8 Sep 2009 19:21:00 -0400 Received: from cantor.suse.de ([195.135.220.2]:55988 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562AbZIHXVA (ORCPT ); Tue, 8 Sep 2009 19:21:00 -0400 Date: Wed, 9 Sep 2009 01:20:59 +0200 (CEST) From: Jiri Kosina X-X-Sender: jikos@twin.jikos.cz To: Nikos Chantziaras Cc: Juergen Beisert , linux-kernel@vger.kernel.org, Arjan van de Ven Subject: Re: BFS vs. mainline scheduler benchmarks and measurements In-Reply-To: <4AA6D40F.6040600@arcor.de> Message-ID: References: <20090906205952.GA6516@elte.hu> <20090908013800.296a5fb5@infradead.org> <4AA62E4E.4040700@arcor.de> <200909081332.46129.jbe@pengutronix.de> <4AA6D40F.6040600@arcor.de> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 9 Sep 2009, Nikos Chantziaras wrote: > > > Here the result: > > > > > > http://foss.math.aegean.gr/~realnc/pics/latop2.png > > > > > > Again: this is on an Intel Core 2 Duo CPU. > > > > Just an idea: Maybe some system management code hits you? > > I'm not sure what is meant with "system management code." System management interrupt happens when firmware/BIOS/HW-debugger is executed in privilege mode so high, that even OS can't do anything about that. It is used in many situations, such as - memory errors - ACPI (mostly fan control) - TPM OS has small to none possibility to influence SMI/SMM. But if this would be the cause, you should probably obtain completely different results on different hardware configuration (as it is likely to have completely different SMM behavior). -- Jiri Kosina SUSE Labs, Novell Inc.