Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753975Ab2E3PEf (ORCPT ); Wed, 30 May 2012 11:04:35 -0400 Received: from ernst.netinsight.se ([194.16.221.21]:56503 "HELO ernst.netinsight.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751356Ab2E3PEd (ORCPT ); Wed, 30 May 2012 11:04:33 -0400 X-Greylist: delayed 602 seconds by postgrey-1.27 at vger.kernel.org; Wed, 30 May 2012 11:04:33 EDT Date: Wed, 30 May 2012 16:54:26 +0200 (CEST) Message-Id: <20120530.165426.1421117300206344483.anders@netinsight.net> To: dsmythies@telus.net Cc: jrnieder@gmail.com, linux-kernel@vger.kernel.org, leslaw.kopec@nasza-klasa.pl, aman@tmm1.net, a.p.zijlstra@chello.nl, tglx@linutronix.de Subject: Re: [3.2.16 -> 3.2.17 regression] High reported CPU load when idle From: Anders =?iso-8859-1?Q?Bostr=F6m?= In-Reply-To: <000c01cd3e70$b651dd10$22f59730$@net> References: <20120523215359.GA19798@burratino> <20120524214516.GB1158@burratino> <000c01cd3e70$b651dd10$22f59730$@net> X-Mailer: Mew version 6.4 on Emacs 23.4 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1240 Lines: 23 >>>>> "DS" == Doug Smythies writes: DS> This statement: "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." DS> In my opinion has the following mistakes: DS> . The computer is not actually idle. If it was actually idle the reported load average would be 0. Well, I tested in single user mode, with very few processes running, mostly init, getty, bash and top (+ a lot of kernel threads). And 3.2.17 reported a load of >0.5 . Under the same conditions 3.2.16 typically reports 0.01 or 0.00 . DS> . Yes, the new kernel reported load average is high, as detailed in the PNG file or the web notes. DS> . The older kernel suffers from a different problem, under all other conditions being the same, the reported load average would have been too low. I don't know if 0.01 is *too* low, but it should be much closer to the truth than >0.5. / Anders -- 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/