From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753781Ab0BJKdD (ORCPT ); Wed, 10 Feb 2010 05:33:03 -0500 Received: from hera.kernel.org ([140.211.167.34]:36437 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752204Ab0BJKdA (ORCPT ); Wed, 10 Feb 2010 05:33:00 -0500 Message-ID: <4B728CFE.40208@kernel.org> Date: Wed, 10 Feb 2010 19:39:58 +0900 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-1.1.1 Thunderbird/3.0 MIME-Version: 1.0 To: "Eric W. Biederman" CC: =?UTF-8?B?QW3DqXJpY28gV2FuZw==?= , Neil Brown , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: Re: [PATCH] sysfs: differentiate between locking links and non-links References: <19314.1869.847327.15190@notabene.brown> <2375c9f91002091808n713275dsc9ace8f51871364e@mail.gmail.com> <4B7217CF.2080702@kernel.org> In-Reply-To: X-Enigmail-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 10 Feb 2010 10:32:54 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/10/2010 05:03 PM, Eric W. Biederman wrote: > Tejun Heo writes: > >> Hello, >> >> On 02/10/2010 11:08 AM, Américo Wang wrote: >>> This bug report is new for me. Recently we received lots of sysfs lockdep >>> warnings, I am working on a patch to fix all the bogus ones. >>> >>> However, this one is _not_ similar to the other cases, as you decribed. >>> This patch could fix the problem, but not a good fix, IMO. We need more >>> work in sysfs layer to fix this kind of things. I will take care of this. >> >> Can't we just give each s_active lock a separate class? Would that be >> too costly? > > When I asked the question earlier I was told that that locking classes > require static storage. Where would that static storage come from? Maybe I'm glossly misunderstanding it but wouldn't embedding struct lockdep_map into sysfs_node as in work_struct do the trick? Thanks. -- tejun