From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752521Ab0ILKbd (ORCPT ); Sun, 12 Sep 2010 06:31:33 -0400 Received: from rhlx01.hs-esslingen.de ([129.143.116.10]:58738 "EHLO rhlx01.hs-esslingen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045Ab0ILKbc (ORCPT ); Sun, 12 Sep 2010 06:31:32 -0400 Date: Sun, 12 Sep 2010 12:31:30 +0200 From: Andreas Mohr To: Louis-David Mitterrand Cc: linux-kernel@vger.kernel.org Subject: Re: ksoftirqd/n permanently eating 60% of a CPU Message-ID: <20100912103130.GA21790@rhlx01.hs-esslingen.de> Mail-Followup-To: linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100905173905.GA7387@apartia.fr> X-Priority: none User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Since there hasn't been a reply in a week, let me try to provide at least a semi-useless one ;) Such high use probably means that something in the kernel keeps retriggering some tasklet(?) since it thinks that something hasn't been done yet (i.e., the tasklet that got triggered didn't manage to satisfy the success criteria of its owner), or it means that something "legitimately" uses obscene amounts of softirqd activity (perhaps some debug infrastructure such as memory tracing or logging or some such). Thus: 1. boot with "single" or "init=/bin/bash" kernel commandline and check whether the activity still happens 2. if not: boot normally, then remove kernel modules via rmmod one at a time, and try shutting down various daemons, to try to find out which component exactly messes it up And perhaps running powertop would provide some clues as to the origin of this CPU hog, despite being a wakeup-specific tracer. HTH, Andreas Mohr