From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754607Ab1K1UoQ (ORCPT ); Mon, 28 Nov 2011 15:44:16 -0500 Received: from one.firstfloor.org ([213.235.205.2]:59367 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753522Ab1K1UoP (ORCPT ); Mon, 28 Nov 2011 15:44:15 -0500 Date: Mon, 28 Nov 2011 21:44:12 +0100 From: Andi Kleen To: Nicolas Kalkhof Cc: Andi Kleen , linux-kernel@vger.kernel.org, deepthi@linux.vnet.ibm.com Subject: Re: Too many poll_idle cpu calls in kernel 3.2 rc-series Message-ID: <20111128204412.GM24062@one.firstfloor.org> References: <492649473.3864850.1322512273580.JavaMail.fmail@mwmweb020> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <492649473.3864850.1322512273580.JavaMail.fmail@mwmweb020> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 28, 2011 at 09:31:13PM +0100, Nicolas Kalkhof wrote: > Andi, > > correct. The issue was introduced somewhere between 3.1 final and 3.2-rc1. I've tried to track down the bad commit but so far I haven't been successfull. The only workaround I found is to set the idle boot parameter to mwait and to disable CONFIG_INTEL_IDLE. Somehow the kernel seems to set idle to poll by default - no idea why :-(. I wonder if other mobile sandy bridge cpus are affected as well. There are only a few changesets affecting drivers/idle Can you try to git revert 46bcfad7a819bd17ac4e831b04405152d59784ab 4202735e8ab6ecfb0381631a0d0b58fefe0bd4e2 e978aa7d7d57d04eb5f88a7507c4fb98577def77 ? -Andi