Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760857Ab2EWVyT (ORCPT ); Wed, 23 May 2012 17:54:19 -0400 Received: from mail-gg0-f174.google.com ([209.85.161.174]:49320 "EHLO mail-gg0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754397Ab2EWVyR convert rfc822-to-8bit (ORCPT ); Wed, 23 May 2012 17:54:17 -0400 Date: Wed, 23 May 2012 16:53:59 -0500 From: Jonathan Nieder To: Anders =?utf-8?Q?Bostr=C3=B6m?= Cc: linux-kernel@vger.kernel.org, =?utf-8?B?TGVzxYJhdyBLb3BlxIc=?= , Aman Gupta , Doug Smythies Subject: Re: [3.2.16 -> 3.2.17 regression] High reported CPU load when idle Message-ID: <20120523215359.GA19798@burratino> References: <20120523.144057.899060240318474097.anders@netinsight.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <20120523.144057.899060240318474097.anders@netinsight.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1712 Lines: 46 Hi Anders, Anders Boström wrote[1]: > Starting with 3.2.17-1, the CPU load accounting is broken when the > computer is idle. The CPU load is reported as >0.50 when > idle. 3.2.16-1 don't suffer from this problem. > > Suspected patch is the upstream patch > "sched: Fix nohz load accounting -- again!" > commit 5e2d50da11f0e6ec3ce8fe658d7c83b0b4346c68 to 3.2 and > originating from c308b56b5398779cd3da0f62ab26b0453494c3d4 . > > See also: > > https://bugs.launchpad.net/unity/+bug/991370 > https://lkml.org/lkml/2012/5/22/310 > https://bugzilla.redhat.com/show_bug.cgi?id=822877 > https://bbs.archlinux.org/viewtopic.php?id=141289 Thanks for writing. If I understand correctly, the load average calculation both before and after that commit is broken, in different ways. I'm cc-ing Lesław Kopeć, Aman Gupta, and Doug Smythies who worked on the above change[2]. I recommend pulling Thomas Gleixner into the conversation once you have a better idea of what's going on or a new change to recommend. If you'd like to also track this on a bugtracker, http://bugzilla.kernel.org/, product Process Management, component Scheduler might be a good place. Aside from that, I can't really offer much to help you, but others on linux-kernel might. Hope that helps, Jonathan [1] http://bugs.debian.org/674153 [2] http://thread.gmane.org/gmane.linux.kernel/1249223/focus=1262319 [3] http://thread.gmane.org/gmane.linux.kernel/1291870/focus=1292058 -- 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/