From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752341AbaBMWPV (ORCPT ); Thu, 13 Feb 2014 17:15:21 -0500 Received: from mail-qa0-f45.google.com ([209.85.216.45]:33714 "EHLO mail-qa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751320AbaBMWPT (ORCPT ); Thu, 13 Feb 2014 17:15:19 -0500 Date: Thu, 13 Feb 2014 17:15:15 -0500 From: Tejun Heo To: Peter Zijlstra Cc: Li Zhong , Tommi Rantala , Ingo Molnar , LKML , Dave Jones , trinity@vger.kernel.org Subject: Re: lockdep: strange %s#5 lock name Message-ID: <20140213221515.GL17608@htj.dyndns.org> References: <20140210192846.GF27965@twins.programming.kicks-ass.net> <20140210215224.GB25350@mtj.dyndns.org> <20140211110036.GT9987@twins.programming.kicks-ass.net> <20140211152741.GA24490@htj.dyndns.org> <1392266124.4974.35.camel@ThinkPad-T5421.cn.ibm.com> <20140213212645.GG17608@htj.dyndns.org> <20140213213253.GF27965@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140213213253.GF27965@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 13, 2014 at 10:32:53PM +0100, Peter Zijlstra wrote: > On Thu, Feb 13, 2014 at 04:26:45PM -0500, Tejun Heo wrote: > > > It seems to me that when the second time alloc_workqueue() is called > > > from the same code path, it would have two locks with the same key, but > > > not the same &wq->name, which doesn't meet lockdep's assumption. > > > > Dang... I reverted the previous patch for now. Peter, does this > > approach sound good to you? > > Whatever works I suppose; like Li said; a little ugly but not sure we > can do better. Cool, Li, can you please spin it on top of v3.14-rc1 w/ SOB and description. Thanks. -- tejun