From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754800AbZBKGnK (ORCPT ); Wed, 11 Feb 2009 01:43:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751439AbZBKGm4 (ORCPT ); Wed, 11 Feb 2009 01:42:56 -0500 Received: from static-220-247-10-204.b-man.svips.gol.ne.jp ([220.247.10.204]:51442 "EHLO smtp.kamineko.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957AbZBKGmz (ORCPT ); Wed, 11 Feb 2009 01:42:55 -0500 Date: Wed, 11 Feb 2009 15:42:53 +0900 From: Mattia Dongili To: Guilherme Malschitzky Schroeder Cc: linux-kernel@vger.kernel.org, venkatesh.pallipadi@intel.com, CPUFreq Mailing List , ACPI Devel Mailing List Subject: Re: ACPI regression in 2.6.29 - cpufreq_performance doesn't work Message-ID: <20090211064253.GC641@kamineko.org> References: <20090210045803.GA31755@kamineko.org> <20090210110802.GB31755@kamineko.org> <20090211051017.GA641@kamineko.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Message-Flag: Cranky? Try Free Software instead! X-Operating-System: Linux 2.6.26-1 i686 X-Editor: Vim http://www.vim.org/ X-Disclaimer: Buh! User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 11, 2009 at 03:58:07AM -0200, Guilherme Malschitzky Schroeder wrote: > On Wed, Feb 11, 2009 at 3:10 AM, Mattia Dongili wrote: > > On Wed, Feb 11, 2009 at 12:15:35AM -0200, Guilherme Malschitzky Schroeder wrote: ... > > Ha! can you check the value for > > /sys/devices/system/cpu/cpu{0,1}/cpufreq/related_cpus > > ? errr... sorry, I meant to say /sys/devices/system/cpu/cpu{0,1}/cpufreq/affected_cpus > > or even include the full output of cpufreq-info with both kernels. anyway from this you can see that there is actually a change (cpufreq-info reads from affected_cpus and in 2.6.28 sys/.../cpu1/cpufreq should be a link to ../cpu0/cpufreq): > Here it's: > > 2.6.28.4 ... > # cpufreq-info > cpufrequtils 004: cpufreq-info (C) Dominik Brodowski 2004-2006 > Report errors and bugs to cpufreq@lists.linux.org.uk, please. > analyzing CPU 0: > driver: acpi-cpufreq > CPUs which need to switch frequency at the same time: 0 1 ... > 2.6.29-rc4 ... > # cpufreq-info > cpufrequtils 004: cpufreq-info (C) Dominik Brodowski 2004-2006 > Report errors and bugs to cpufreq@lists.linux.org.uk, please. > analyzing CPU 0: > driver: acpi-cpufreq > CPUs which need to switch frequency at the same time: 0 ... > analyzing CPU 1: > driver: acpi-cpufreq > CPUs which need to switch frequency at the same time: 1 So I guess you have one of those bioses that prefer sw coordination if not told to use hw's as explained in the commit message. And cpufreq-set behaves as it always did ;) ... > >> >> >> commit d96f94c604453f87fe24154b87e1e9a3a72511f8 > >> >> >> Author: Pallipadi, Venkatesh > >> >> >> Date: Mon Feb 2 11:57:18 2009 -0800 > >> >> >> > >> >> >> ACPI: Enable bit 11 in _PDC to advertise hw coord > >> >> >> > >> >> >> Bit 11 in intel PDC definitions is meant for OS capability to handle > >> >> >> hardware coordination of P-states. In Linux we have always supported > >> >> >> hwardware coordination of P-states. Just let the BIOSes know that we > >> >> >> support it, by setting this bit. > >> >> >> > >> >> >> Some BIOSes use this bit to choose between hardware or software coordination > >> >> >> and without this change below, BIOSes switch to software coordination, which > >> >> >> is not very optimal in terms of power consumption and extra > >> >> >> wakeups from idle. > >> >> >> > >> >> >> Signed-off-by: Venkatesh Pallipadi > >> >> >> Signed-off-by: Len Brown -- mattia :wq!