From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754313Ab0IMHyE (ORCPT ); Mon, 13 Sep 2010 03:54:04 -0400 Received: from mail.lncsa.com ([213.215.28.11]:60283 "EHLO sargon.lncsa.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751434Ab0IMHyC (ORCPT ); Mon, 13 Sep 2010 03:54:02 -0400 Date: Mon, 13 Sep 2010 09:52:37 +0200 From: Louis-David Mitterrand To: linux-kernel@vger.kernel.org Subject: Re: ksoftirqd/n permanently eating 60% of a CPU Message-ID: <20100913075237.GA18081@apartia.fr> Mail-Followup-To: linux-kernel@vger.kernel.org References: <20100912154138.GA23554@apartia.fr> <20100912185715.GA8775@rhlx01.hs-esslingen.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100912185715.GA8775@rhlx01.hs-esslingen.de> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 12, 2010 at 08:57:15PM +0200, Andreas Mohr wrote: > > Examining /proc/interrupts shows that "Local timer interrupts" are > > mainly firing. > > > Strangely enough, the interrupt storm starts only 5 minutes or so after > > bootup. > > And have you tried running powertop or manually (perhaps via > sophisticated shell script) keeping a watch on > /proc/timer[list|stats]? Hi, powertop seems to give a strong hint: 54.5% (250.2) [kernel core] dsp_cmx_send (dsp_cmx_send) 25.8% (118.6) usbhid-ups 5.8% ( 26.7) [ahci] 2.6% ( 12.0) [kernel core] usb_hcd_poll_rh_status (rh_timer_func) Apparently dsp_cmx_send is in the mISDN stack which, in my kernel, is compiled statically. This happens regardless of the box having isdn hardware.