From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751591AbZLWA7d (ORCPT ); Tue, 22 Dec 2009 19:59:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751117AbZLWA7c (ORCPT ); Tue, 22 Dec 2009 19:59:32 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:53760 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750940AbZLWA7b (ORCPT ); Tue, 22 Dec 2009 19:59:31 -0500 Message-ID: <4B316B66.2020206@cn.fujitsu.com> Date: Wed, 23 Dec 2009 08:59:18 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b3pre) Gecko/20090513 Fedora/3.0-2.3.beta2.fc11 Thunderbird/3.0b2 MIME-Version: 1.0 To: Peter Zijlstra CC: rostedt@goodmis.org, Ingo Molnar , Frederic Weisbecker , LKML Subject: Re: [PATCH] tracing: Fix lockdep warning in global_clock() References: <4B2F1543.8020300@cn.fujitsu.com> <20091221064356.GA2378@elte.hu> <4B2F2588.8070501@cn.fujitsu.com> <1261406427.4314.155.camel@laptop> <1261410984.25193.8.camel@gandalf.stny.rr.com> <4B305680.4090304@cn.fujitsu.com> <1261470234.4937.1.camel@laptop> In-Reply-To: <1261470234.4937.1.camel@laptop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra wrote: > On Tue, 2009-12-22 at 13:17 +0800, Li Zefan wrote: > >> Looking into sched_clock.c, seems the only place that can trigger lockdep >> is the local_irq_* in cpu_clock(), though I'm not sure for architecture- >> specific sched_clock(). > > But why would you want to do that? that reduces the lockdep coverage for > no good reason, just fix up the tracer. > Then the proper fix is to use local_irq_* in global_clock(), which is what this patch does.