Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757409Ab0BHDGU (ORCPT ); Sun, 7 Feb 2010 22:06:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55834 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754134Ab0BHDGS (ORCPT ); Sun, 7 Feb 2010 22:06:18 -0500 Message-ID: <4B6F7FD0.9010500@redhat.com> Date: Mon, 08 Feb 2010 11:06:56 +0800 From: Cong Wang User-Agent: Thunderbird 2.0.0.23 (X11/20091001) MIME-Version: 1.0 To: Alan Stern CC: Peter Zijlstra , "Eric W. Biederman" , Greg KH , Thomas Gleixner , Kernel development list , Tejun Heo , Miles Lane , Heiko Carstens , Benjamin Herrenschmidt , Larry Finger , Andrew Morton Subject: Re: [Patch 0/2] sysfs: fix s_active lockdep warning References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 956 Lines: 26 Alan Stern wrote: > On Fri, 5 Feb 2010, Peter Zijlstra wrote: > >> Right, so this device stuff is much more complicated than I was led to >> believe ;-) > > Haven't I told you all along that tree-structured locking is > complicated? :-) > >> So the device core doesn't know, so how are you guys making sure there >> really are no deadlocks hidden in there somewhere? > > In the code I've seen, deadlocks are avoided by always taking the locks > in the same order. But who knows? Maybe there _are_ some hidden > deadlocks lurking. For now we can't rely on lockdep to find them, > though, because it gets sidetracked by all the false positives. > This is almost the same with the sysfs case... Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/