From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752665Ab1AOO3a (ORCPT ); Sat, 15 Jan 2011 09:29:30 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:45626 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750966Ab1AOO32 (ORCPT ); Sat, 15 Jan 2011 09:29:28 -0500 Date: Sat, 15 Jan 2011 15:28:57 +0100 From: Ingo Molnar To: linux-kernel@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, paul.mckenney@linaro.org, rmk+kernel@arm.linux.org.uk, weber@corscience.de, paulmck@linux.vnet.ibm.com, tglx@linutronix.de Cc: linux-tip-commits@vger.kernel.org Subject: Re: [tip:core/urgent] rcu: avoid pointless blocked-task warnings Message-ID: <20110115142857.GA8610@elte.hu> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * tip-bot for Paul E. McKenney wrote: > Commit-ID: b24efdfdf679cf9b05947c531971905fc727dd40 > Gitweb: http://git.kernel.org/tip/b24efdfdf679cf9b05947c531971905fc727dd40 > Author: Paul E. McKenney > AuthorDate: Wed, 12 Jan 2011 14:18:11 -0800 > Committer: Paul E. McKenney > CommitDate: Fri, 14 Jan 2011 04:58:08 -0800 > > rcu: avoid pointless blocked-task warnings > > If the RCU callback-processing kthread has nothing to do, it parks in > a wait_event(). If RCU remains idle for more than two minutes, the > kernel complains about this. This commit changes from wait_event() > to wait_event_interruptible() to prevent the kernel from complaining > just because RCU is idle. Btw., a sidenote, it's not just about the blocked-tasks lockup detector warning, uninterruptible sleeps will also artificially inflate the load average of the box, +1.0 per such task. So it's definitely a bug to sleep for a very long time uninterruptible. Thanks, Ingo