From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754758Ab1K1UbP (ORCPT ); Mon, 28 Nov 2011 15:31:15 -0500 Received: from fmmailgate04.web.de ([217.72.192.242]:56461 "EHLO fmmailgate04.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754402Ab1K1UbO convert rfc822-to-8bit (ORCPT ); Mon, 28 Nov 2011 15:31:14 -0500 Date: Mon, 28 Nov 2011 21:31:13 +0100 (CET) From: "Nicolas Kalkhof" To: "Andi Kleen" Cc: linux-kernel@vger.kernel.org Message-ID: <492649473.3864850.1322512273580.JavaMail.fmail@mwmweb020> Subject: Re: Too many poll_idle cpu calls in kernel 3.2 rc-series MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Priority: 3 Importance: normal Sensitivity: Normal X-Provags-ID: V01U2FsdGVkX19XpxYdMAmW1ArwEp2RoB386ZUlWbBoNrgCJH8joGBwnkfFMkv67ZkM uRH13VKkcKcskMC20JacfA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Regards, Nic -----Ursprüngliche Nachricht----- Von: "Andi Kleen" Gesendet: Nov 28, 2011 8:33:28 PM An: "Nicolas Kalkhof" Betreff: Re: Too many poll_idle cpu calls in kernel 3.2 rc-series >"Nicolas Kalkhof" writes: > >> the kernel v3.2 series shows excessive poll_idle calls during system idle phases causing the cpu >> (mobile i7 2620M) to heat up and draw additional 10% more power.  All kernel versions between >> 3.2-rc1 and 3.2-rc3 are affected. Perf Top and Powertop both show the same issue. >> I've posted a similar bug report before: http://marc.info/?l=linux-kernel&m=132164909313594&w=2 >> and used perf top -U to verify the poll_idle calls as requested. > >So it didn't happen with earlier kernels? >I would suggest a git bisect in this case. > >-Andi > >-- >ak@linux.intel.com -- Speaking for myself only >-- >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html >Please read the FAQ at http://www.tux.org/lkml/ ___________________________________________________________ SMS schreiben mit WEB.DE FreeMail - einfach, schnell und kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192