From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752368AbWKAUxX (ORCPT ); Wed, 1 Nov 2006 15:53:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752369AbWKAUxX (ORCPT ); Wed, 1 Nov 2006 15:53:23 -0500 Received: from www.osadl.org ([213.239.205.134]:13483 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S1752367AbWKAUxW (ORCPT ); Wed, 1 Nov 2006 15:53:22 -0500 Subject: Re: 2.6.19-rc4-mm1: noidlehz problems From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Matthew Garrett Cc: Arjan van de Ven , Pavel Machek , kernel list , mingo@redhat.com, Andrew Morton In-Reply-To: <20061101152201.GA13634@srcf.ucam.org> References: <20061101122319.GA13056@elf.ucw.cz> <1162386177.23744.17.camel@laptopd505.fenrus.org> <20061101152201.GA13634@srcf.ucam.org> Content-Type: text/plain Date: Wed, 01 Nov 2006 21:55:01 +0100 Message-Id: <1162414502.15900.261.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2006-11-01 at 15:22 +0000, Matthew Garrett wrote: > On Wed, Nov 01, 2006 at 02:02:57PM +0100, Arjan van de Ven wrote: > > > In some (hardware) C-states, the local apic timer stops (as does the > > TSC), while in others it keeps running. If you change from AC to > > battery, the bios can change the meaning of a software C-state from one > > where local apic timer keeps going to one where it stops. This obviously > > upsets the hrtimers/tickless code since that uses local apic timer for > > event generation.... > > Is there any hope of working around this? I'd have expected that the > most useful case for the tickless code was also the case where we want > to be using C3/C4... Can you try the following patches please ? http://tglx.de/projects/hrtimers/2.6.19-rc4-mm1/patch-2.6.19-rc4-mm1-hrt-dyntick1.patch This addresses the C34/C4 issue tglx