From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754678Ab1K1TzO (ORCPT ); Mon, 28 Nov 2011 14:55:14 -0500 Received: from eazy.amigager.de ([213.239.192.238]:56518 "EHLO eazy.amigager.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754449Ab1K1TzK (ORCPT ); Mon, 28 Nov 2011 14:55:10 -0500 Date: Mon, 28 Nov 2011 20:55:34 +0100 From: Tino Keitel To: "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org, "Artem S. Tashkinov" Subject: Re: [REGRESSION] [Linux 3.2] top/htop and all other CPU usage metering applications has gone crackers Message-ID: <20111128195533.GA26460@mac.home> Mail-Followup-To: "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, "Artem S. Tashkinov" References: <1718181782.740375.1322130615898.JavaMail.mail@webmail19> <20111124200553.GA13353@mac.home> <20111127110400.GA4672@mac.home> <201111271245.57772.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201111271245.57772.rjw@sisk.pl> 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 On Sun, Nov 27, 2011 at 12:45:57 +0100, Rafael J. Wysocki wrote: > On Sunday, November 27, 2011, Tino Keitel wrote: > > On Thu, Nov 24, 2011 at 21:05:53 +0100, Tino Keitel wrote: > > > On Thu, Nov 24, 2011 at 10:30:15 +0000, Artem S. Tashkinov wrote: > > > > Hello, > > > > > > > > I'd like to report a weird regression in Linux 3.2 (running rc3 now) - all CPU metering applications have gone terribly mad > > > > under this kernel: > > > > > > I get the same using top, htop and the gnome system monitor with kernel > > > 3.2 on a Sandy Bridge quad core box, running Debian unstable. > > > > I just tested 3.2-rc2, and see the same bug. > > I'm seeing that too on one of my test boxes, but not all the time > (i.e. there are periods in which the readings are correct). The other boxes > I've tested with 3.2-rc are fine in that respect. > > Also, it seems that it shows 100%-(real load) when it is wrong. So, it looks > like there's an overflow somewhere in the CPU load measuring code, at least > on some CPUs. Hi, I reverted this commit and so far it looks good: commit a25cac5198d4ff2842ccca63b423962848ad24b2 Author: Michal Hocko Date: Wed Aug 24 09:40:25 2011 +0200 proc: Consider NO_HZ when printing idle and iowait times I'll report back tomorrow how the kernel behaves. Regards, Tino