From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765032AbYEUCF7 (ORCPT ); Tue, 20 May 2008 22:05:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757235AbYEUCFs (ORCPT ); Tue, 20 May 2008 22:05:48 -0400 Received: from ti-out-0910.google.com ([209.85.142.191]:40808 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756687AbYEUCFq (ORCPT ); Tue, 20 May 2008 22:05:46 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=We0t2GtWzkXC21LbpqDnR5TiiFxUUlou4r1ZFFQdBssqLdR+1qZssW0EOmVK6o5N7RONw0D7k74G1qSptbGBaYY8fj1mlzeKtHQrRPByok0EgxYAJFP1Vfz/SfuY0sT1AU+OIj/4uTA7Nm1lsf2u+hNEXemCz0crocDfCXc2JAY= Message-ID: Date: Wed, 21 May 2008 10:05:42 +0800 From: "Dave Young" To: "Andrew Morton" Subject: Re: [PATCH 1/3][-mm] add class_reclassify macro Cc: "Matthew Wilcox" , greg@kroah.com, kay.sievers@vrfy.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org In-Reply-To: <20080520122356.63bd0000.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080520095553.GA3201@darkstar.te-china.tietoenator.com> <20080520030232.fc91b64e.akpm@linux-foundation.org> <20080520103045.2bb0a033.akpm@linux-foundation.org> <20080520173640.GP2638@parisc-linux.org> <20080520122356.63bd0000.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 21, 2008 at 3:23 AM, Andrew Morton wrote: > On Tue, 20 May 2008 11:36:41 -0600 > Matthew Wilcox wrote: > >> On Tue, May 20, 2008 at 10:30:45AM -0700, Andrew Morton wrote: >> > Well what are these lockdep warnings? Normally such a warning means that >> > we have a locking bug. I _assume_ that you've determined that the warnings >> > are false-positives? >> >> Andrew, we already discussed this on the thread you started that you >> then ignored ... > > rofl. > > All pertinent information should be in a patch's changelog. Then this > sort of confusion will not occur. My wrong. should do this in advance. > >> > The warning which Mariusz Kozlowski discovered ("Subject: Re: >> > 2.6.26-rc2-mm1: possible circular locking dependency detected") was >> > triggered by the "class semaphore to mutex" conversion and it looks >> > like a real bug to me. Would your patch prevent warnings such as that >> > one from being available to us? >> >> The problem is that you add one type of class which then adds devices >> that are of another class. This is not a bug. My proposal is to give >> each sysfs class its own lock class; Dave's is to only do it for the >> two classes he knows about that do this. > > Well that sounds reasonable. I'm not sure that we should introduce > generic-looking helper infrastructure to do it, however. > > Anyway I'll happily sit back and let you guys and Greg sort this one out ;) >