Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752952AbZJZSTf (ORCPT ); Mon, 26 Oct 2009 14:19:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752301AbZJZSTf (ORCPT ); Mon, 26 Oct 2009 14:19:35 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:56638 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752473AbZJZSTe (ORCPT ); Mon, 26 Oct 2009 14:19:34 -0400 Date: Mon, 26 Oct 2009 18:19:34 +0000 From: Matthew Garrett To: Robert Bradbury Cc: linux-kernel@vger.kernel.org Subject: Re: Broken ondemand scheduler in Linux 2.6.30+ on Pentium IVs Message-ID: <20091026181934.GA4657@srcf.ucam.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@cavan.codon.org.uk X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 656 Lines: 14 The ondemand governor assumes that frequency transitions occur at low latency. This isn't usefully the case with p4-clockmod, and running ondemand there will generally show obvious performance regressions. If you have a recent enough P4 use the acpi-cpufreq driver instead. If not, the conservative governor should still work and is a better fit to the hardware. -- Matthew Garrett | mjg59@srcf.ucam.org -- 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/