From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754856Ab1K0LnI (ORCPT ); Sun, 27 Nov 2011 06:43:08 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:58520 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752941Ab1K0LnG (ORCPT ); Sun, 27 Nov 2011 06:43:06 -0500 From: "Rafael J. Wysocki" To: Tino Keitel Subject: Re: [REGRESSION] [Linux 3.2] top/htop and all other CPU usage metering applications has gone crackers Date: Sun, 27 Nov 2011 12:45:57 +0100 User-Agent: KMail/1.13.6 (Linux/3.2.0-rc3+; KDE/4.6.0; x86_64; ; ) Cc: linux-kernel@vger.kernel.org, "Artem S. Tashkinov" References: <1718181782.740375.1322130615898.JavaMail.mail@webmail19> <20111124200553.GA13353@mac.home> <20111127110400.GA4672@mac.home> In-Reply-To: <20111127110400.GA4672@mac.home> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201111271245.57772.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. What's your CPU, BTW? Thanks, Rafael