From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932476Ab1KGN1k (ORCPT ); Mon, 7 Nov 2011 08:27:40 -0500 Received: from mail-qy0-f174.google.com ([209.85.216.174]:48587 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754377Ab1KGN1j (ORCPT ); Mon, 7 Nov 2011 08:27:39 -0500 Date: Mon, 7 Nov 2011 21:26:02 +0800 From: Yong Zhang To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, sergey.senozhatsky@gmail.com, bp@alien8.de, Ingo Molnar Subject: Re: [RFC PATCH 4/4] lockdep: fix race condition in __lock_set_class() Message-ID: <20111107132602.GA2783@zhy> Reply-To: Yong Zhang References: <1320398790-21663-1-git-send-email-yong.zhang0@gmail.com> <1320398790-21663-5-git-send-email-yong.zhang0@gmail.com> <1320669054.18053.25.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1320669054.18053.25.camel@twins> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 07, 2011 at 01:30:54PM +0100, Peter Zijlstra wrote: > On Fri, 2011-11-04 at 17:26 +0800, Yong Zhang wrote: > > When someone call lock_set_class() with valid key, nothing > > protect the initializing of 'lockdep_map'; thus could lead > > to flase positive warning from lockdep (such as "key not in > > .data!"). This patch cure that potential issue. > > How? that warning is triggered of the lock_class_key * passed into > lockdep_init_map and is unrelated to the actual content of the > lockdep_map. Oh, my fault, the false positive warning could be "non-static key". But seems we should find the right direction for this bug :) Some comments in replies to patch#1. Thanks, Yong