From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753569AbYGaQfW (ORCPT ); Thu, 31 Jul 2008 12:35:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751813AbYGaQfJ (ORCPT ); Thu, 31 Jul 2008 12:35:09 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:42370 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751613AbYGaQfI (ORCPT ); Thu, 31 Jul 2008 12:35:08 -0400 Date: Thu, 31 Jul 2008 18:34:56 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: David Miller , linux-kernel@vger.kernel.org Subject: Re: [PATCH] lockdep: change scheduler annotation Message-ID: <20080731163456.GE26393@elte.hu> References: <20080728.161318.38361710.davem@davemloft.net> <20080728235133.GA7956@elte.hu> <20080728.174415.154327359.davem@davemloft.net> <20080729.214503.126934382.davem@davemloft.net> <1217417217.8157.23.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1217417217.8157.23.camel@twins> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.1 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.1 required=5.9 tests=BAYES_05 autolearn=no SpamAssassin version=3.2.3 -1.1 BAYES_05 BODY: Bayesian spam probability is 1 to 5% [score: 0.0190] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > While thinking about David's patch it _finally_ dawned on me that > there is no reason we have a lock class per cpu.. /me arghs too! :) > Sorry for being dense :-/ > > The below changes the annotation from a lock class per cpu, to a > single nested lock, as the scheduler never holds more that 2 rq locks > at a time anyway. > > If there was code requiring holding all rq locks this would not work > and the original annotation would be the only option, but that not > being the case, this is a much lighter one. > > Compiles and boots on a 2-way x86_64. applied to tip/sched/urgent - thanks Peter! Ingo