From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757302AbYEOWSS (ORCPT ); Thu, 15 May 2008 18:18:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753205AbYEOWSI (ORCPT ); Thu, 15 May 2008 18:18:08 -0400 Received: from mail.gmx.net ([213.165.64.20]:47810 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751790AbYEOWSH (ORCPT ); Thu, 15 May 2008 18:18:07 -0400 X-Authenticated: #5039886 X-Provags-ID: V01U2FsdGVkX1/nEls1K9Tnrur3NyX8c9BRIE78LUAH9a9nTE257Z rOJxFUiN+Z6VP0 Date: Fri, 16 May 2008 00:18:03 +0200 From: =?iso-8859-1?Q?Bj=F6rn?= Steinbrink To: Pascal =?iso-8859-1?Q?Br=FCckner?= Cc: linux-kernel@vger.kernel.org Subject: Re: Strange C3/C4 sleep state behaviour Message-ID: <20080515221803.GA17259@atjola.homenet> References: <482CA6E4.1010807@web.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <482CA6E4.1010807@web.de> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2008.05.15 23:11:00 +0200, Pascal Brückner wrote: > Hello! > > I'm recompiling my kernel recently to optimize the power usage of my > laptop (IBM ThinkPad X31). So far, my most efficient kernel at the > moment is a self-compiled 2.6.22 with phc patches for undervolting, > suspend2/tuxonice and hrtimers patches to force HPET on my ICH4-M chipset. > > Because everyone says, that newer kernel revisions are much more energy > efficient than my 2.6.22, i tried to compile one to reach at least the > energy usage of my recent kernel. > Sadly, this doesn't work because of only one issue: > With activated wireless networking (atheros chipset with recent madwifi > driver) i'm losing much energy due to the fact, that my cpu is > significant more in C2 state than in C3/C4. Do you have CONFIG_CPU_IDLE enabled? That made a huge difference for me. Before that was available, _disabling_ CONFIG_NO_HZ also helped when wifi was enabled (but IIRC made things worse with wifi disabled). Björn