From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752397AbZISTVQ (ORCPT ); Sat, 19 Sep 2009 15:21:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752088AbZISTVP (ORCPT ); Sat, 19 Sep 2009 15:21:15 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:45953 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751734AbZISTVO (ORCPT ); Sat, 19 Sep 2009 15:21:14 -0400 Subject: Re: + sched-fix-raciness-in-runqueue_is_locked.patch added to -mm tree From: Steven Rostedt Reply-To: rostedt@goodmis.org To: akpm@linux-foundation.org Cc: mm-commits@vger.kernel.org, mingo@elte.hu, LKML In-Reply-To: <200909191855.n8JItiko022148@imap1.linux-foundation.org> References: <200909191855.n8JItiko022148@imap1.linux-foundation.org> Content-Type: text/plain Organization: Kihon Technologies Inc. Date: Sat, 19 Sep 2009 15:21:16 -0400 Message-Id: <1253388076.20020.360.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2009-09-19 at 11:55 -0700, akpm@linux-foundation.org wrote: > The patch titled > sched(): fix raciness in runqueue_is_locked() > has been added to the -mm tree. Its filename is > sched-fix-raciness-in-runqueue_is_locked.patch > > Before you just go and hit "reply", please: > a) Consider who else should be cc'ed > b) Prefer to cc a suitable mailing list as well > c) Ideally: find the original patch on the mailing list and do a > reply-to-all to that, adding suitable additional cc's > > *** Remember to use Documentation/SubmitChecklist when testing your code *** > > See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find > out what to do about this > > The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ > > ------------------------------------------------------ > Subject: sched(): fix raciness in runqueue_is_locked() > From: Andrew Morton > > runqueue_is_locked() is unavoidably racy due to a poor interface design. > It does > > cpu = get_cpu() > ret = some_perpcu_thing(cpu); > put_cpu(cpu); > return ret; > > Its return value is unreliable. > > Fix. > > Cc: Ingo Molnar Acked-by: Steven Rostedt > Signed-off-by: Andrew Morton > --- >