From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751435AbZEWEnH (ORCPT ); Sat, 23 May 2009 00:43:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750808AbZEWEm4 (ORCPT ); Sat, 23 May 2009 00:42:56 -0400 Received: from mail.candelatech.com ([208.74.158.172]:44188 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750736AbZEWEm4 (ORCPT ); Sat, 23 May 2009 00:42:56 -0400 Message-ID: <4A177ECE.7080508@candelatech.com> Date: Fri, 22 May 2009 21:42:54 -0700 From: Ben Greear Organization: Candela Technologies User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Ming Lei CC: linux-kernel Subject: Re: Question on lockdep and sysrq - d References: <4A1743C5.9020803@candelatech.com> 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 Ming Lei wrote: > See http://marc.info/?l=linux-kernel&m=124211522525625&w=2. > That is about some real bug in the official kernel. I am almost 100% certain that my own code is at fault here. I'm just trying to better understand the way lockdep prints out all of the locks so I can easier debug my issue. Thanks, Ben > thanks. > > 2009/5/23 Ben Greear : > >> Hello! >> >> I'm trying to debug an apparent deadlock in some code I'm >> writing. >> >> When I do a sysrq 'd', I get a nice dump of locks (I have lockdep enabled). >> >> However, the output appears to show multiple processes holding the >> same locks (rtnl_mutex, for example): >> >> Showing all locks held in the system: >> 3 locks held by events/11/63: >> #0: (events){--..}, at: [] run_workqueue+0xb1/0x216 >> #1: ((linkwatch_work).work){--..}, at: [] >> run_workqueue+0xb1/0x216 >> #2: (rtnl_mutex){--..}, at: [] rtnl_lock+0x12/0x14 >> 1 lock held by irqbalance/3360: >> #0: (rtnl_mutex){--..}, at: [] rtnl_lock+0x12/0x14 >> 1 lock held by hald/3605: >> #0: (rtnl_mutex){--..}, at: [] rtnl_lock+0x12/0x14 >> ... >> >> Is this merely showing processes that are blocked on trying to acquire these >> locks? >> >> If so, is there any way to tell which processes have fully acquired locks >> v/s >> just waiting to acquire them? >> >> Thanks, >> Ben >> -- Ben Greear Candela Technologies Inc http://www.candelatech.com