From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752370AbZKPLTk (ORCPT ); Mon, 16 Nov 2009 06:19:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751181AbZKPLTk (ORCPT ); Mon, 16 Nov 2009 06:19:40 -0500 Received: from hera.kernel.org ([140.211.167.34]:45655 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751134AbZKPLTj (ORCPT ); Mon, 16 Nov 2009 06:19:39 -0500 Date: Mon, 16 Nov 2009 11:18:36 GMT From: tip-bot for Peter Zijlstra Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, suresh.b.siddha@intel.com, tglx@linutronix.de, ghaskins@novell.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, suresh.b.siddha@intel.com, tglx@linutronix.de, ghaskins@novell.com, mingo@elte.hu In-Reply-To: <1258363873.26714.83.camel@laptop> References: <1258363873.26714.83.camel@laptop> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched: Sched_rt_periodic_timer vs cpu hotplug Message-ID: Git-Commit-ID: 047106adcc85e3023da210143a6ab8a55df9e0fc X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 047106adcc85e3023da210143a6ab8a55df9e0fc Gitweb: http://git.kernel.org/tip/047106adcc85e3023da210143a6ab8a55df9e0fc Author: Peter Zijlstra AuthorDate: Mon, 16 Nov 2009 10:28:09 +0100 Committer: Ingo Molnar CommitDate: Mon, 16 Nov 2009 10:46:27 +0100 sched: Sched_rt_periodic_timer vs cpu hotplug Heiko reported a case where a timer interrupt managed to reference a root_domain structure that was already freed by a concurrent hot-un-plug operation. Solve this like the regular sched_domain stuff is also synchronized, by adding a synchronize_sched() stmt to the free path, this ensures that a root_domain stays present for any atomic section that could have observed it. Reported-by: Heiko Carstens Signed-off-by: Peter Zijlstra Acked-by: Heiko Carstens Cc: Gregory Haskins Cc: Siddha Suresh B Cc: Martin Schwidefsky LKML-Reference: <1258363873.26714.83.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index cea2bea..3c91f11 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7912,6 +7912,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) static void free_rootdomain(struct root_domain *rd) { + synchronize_sched(); + cpupri_cleanup(&rd->cpupri); free_cpumask_var(rd->rto_mask);