From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756798Ab1KUVLZ (ORCPT ); Mon, 21 Nov 2011 16:11:25 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:41503 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754379Ab1KUVLX convert rfc822-to-8bit (ORCPT ); Mon, 21 Nov 2011 16:11:23 -0500 From: Maciej Rutecki Reply-To: maciej.rutecki@gmail.com To: "Nicolas Kalkhof" Subject: Re: [REGRESSION] sudden cpu hogging in kernel 3.2 rc-series Date: Mon, 21 Nov 2011 22:11:17 +0100 User-Agent: KMail/1.13.7 (Linux/3.2.0-rc2; KDE/4.6.5; i686; ; ) Cc: "linux-kernel@vger.kernel.org" References: <506786689.810044.1321648395265.JavaMail.fmail@mwmweb010> In-Reply-To: <506786689.810044.1321648395265.JavaMail.fmail@mwmweb010> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Message-Id: <201111212211.17717.maciej.rutecki@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On piątek, 18 listopada 2011 o 21:33:15 Nicolas Kalkhof wrote: > Hello, > > since the merges for kernel 3.2 came in late october, my mobile i7 2620M > sandybridge cpu/gpu seems to run hotter (approx 10 °C) when idling and > after some minutes according to top the cpu load goes up on all cores but > the cpu frequency stays low (800 MHz) as well as the gpu (650MHz) and the > system is responding well. Yet still additional 5-8 watts are continously > drained from the power supply. Something is throttling up :(. Oprofile > shows that the kernel hogs the cpu (see dump below). This happens with > every kernel since the 3.2 merge window closed up to latest linux-next. I > wasn't able to track the bad commit down yet. > > Could someone please confirm the issue? > I observed similar behaviour, few minutes after boot, when KDE is working plasma-desktop process (sometimes another) uses 20-50% cpu. System and kernel works without any kernel, but cpu usage is greater than in 3.1 (and older). Hardware: old hp/compaq nx6310 Add this mail to regression list. Regards -- Maciej Rutecki http://www.mrutecki.pl