From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754405AbZAaNuN (ORCPT ); Sat, 31 Jan 2009 08:50:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752155AbZAaNt7 (ORCPT ); Sat, 31 Jan 2009 08:49:59 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:36672 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750953AbZAaNt6 (ORCPT ); Sat, 31 Jan 2009 08:49:58 -0500 Date: Sat, 31 Jan 2009 14:49:47 +0100 From: Ingo Molnar To: Rusty Russell Cc: linux-kernel@vger.kernel.org, Mike Travis , Steven Rostedt Subject: Re: [PATCH] sched_rt: don't use first_cpu on cpumask created with cpumask_and. Message-ID: <20090131134947.GA23973@elte.hu> References: <200901312321.25344.rusty@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200901312321.25344.rusty@rustcorp.com.au> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 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 * Rusty Russell wrote: > Ingo, please apply to tip/urgent. > > cpumask_and() only initializes nr_cpu_ids bits, so the (deprecated) > first_cpu() might find one of those uninitialized bits if nr_cpu_ids > is less than NR_CPUS (as it can be for CONFIG_CPUMASK_OFFSTACK). > > Signed-off-by: Rusty Russell > --- > kernel/sched_rt.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Applied to tip/sched/urgent, thanks Rusty! Also, Git sorted out the same-content merge with this commit in cpus4096 just fine: d38b223: cpumask: reduce stack usage in find_lowest_rq (this commit is where you backported it from i suspect?) Ingo