From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751103AbWFWIXP (ORCPT ); Fri, 23 Jun 2006 04:23:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751119AbWFWIXO (ORCPT ); Fri, 23 Jun 2006 04:23:14 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:43153 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S1751103AbWFWIXN (ORCPT ); Fri, 23 Jun 2006 04:23:13 -0400 Date: Fri, 23 Jun 2006 10:18:15 +0200 From: Ingo Molnar To: Kirill Korotaev Cc: Linux Kernel Mailing List , Con Kolivas , Andrew Morton Subject: Re: [PATCH] sched: CPU hotplug race vs. set_cpus_allowed() Message-ID: <20060623081815.GA919@elte.hu> References: <449BA349.6040901@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <449BA349.6040901@openvz.org> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5013] 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Kirill Korotaev wrote: > Looks like there is a race between set_cpus_allowed() and > move_task_off_dead_cpu(). __migrate_task() doesn't report any err > code, so task can be left on its runqueue if its cpus_allowed mask > changed so that dest_cpu is not longer a possible target. Also, > chaning cpus_allowed mask requires rq->lock being held. > > Signed-Off-By: Kirill Korotaev good one! Acked-by: Ingo Molnar Ingo