From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Pallipadi, Venkatesh" Subject: Re: [PATCH] Enable bit 11 in _PDC to advertise hw coord Date: Wed, 04 Feb 2009 12:06:42 -0800 Message-ID: <1233778002.4286.61.camel@localhost.localdomain> References: <20090202195717.GA24510@linux-os.sc.intel.com> <20090204085712.GF30821@kernel.dk> <20090204195331.GA905@khazad-dum.debian.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com ([192.55.52.93]:31954 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751540AbZBDUFh (ORCPT ); Wed, 4 Feb 2009 15:05:37 -0500 In-Reply-To: <20090204195331.GA905@khazad-dum.debian.net> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Henrique de Moraes Holschuh Cc: Jens Axboe , Len Brown , "linux-acpi@vger.kernel.org" , Chris Mason , Greg KH , stable kernel On Wed, 2009-02-04 at 11:53 -0800, Henrique de Moraes Holschuh wrote: > On Wed, 04 Feb 2009, Jens Axboe wrote: > > On Mon, Feb 02 2009, Pallipadi, Venkatesh wrote: > > > > > > 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. > > > > I can confirm that this fixes the excessive reschedule ipi count on an > > x60 with the ondemand governor. Can we please get this into 2.6.29? > > And, after that, -stable? > Agreed. This should also go to -stable once it gets into mainline. Thanks, Venki