From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757367Ab3BFP4T (ORCPT ); Wed, 6 Feb 2013 10:56:19 -0500 Received: from mail.candelatech.com ([208.74.158.172]:54468 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756034Ab3BFP4S (ORCPT ); Wed, 6 Feb 2013 10:56:18 -0500 Message-ID: <51127D15.7080503@candelatech.com> Date: Wed, 06 Feb 2013 07:56:05 -0800 From: Ben Greear Organization: Candela Technologies User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Steven Rostedt CC: Linux Kernel Mailing List , Peter Zijlstra , Ingo Molnar Subject: Re: Question on lockdep and MAX_LOCK_DEPTH References: <5111AD8D.1080005@candelatech.com> <20130206015430.GA9161@home.goodmis.org> <5111BF51.5010607@candelatech.com> <1360119124.2621.37.camel@gandalf.local.home> <5111CE60.4080403@candelatech.com> <1360125419.2621.39.camel@gandalf.local.home> <5111F6F6.7010402@candelatech.com> <1360156888.2621.42.camel@gandalf.local.home> In-Reply-To: <1360156888.2621.42.camel@gandalf.local.home> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/06/2013 05:21 AM, Steven Rostedt wrote: > On Tue, 2013-02-05 at 22:23 -0800, Ben Greear wrote: >> On 02/05/2013 08:36 PM, Steven Rostedt wrote: >>> On Tue, 2013-02-05 at 19:30 -0800, Ben Greear wrote: >>> >>>> It's huge, so here's a link: >>>> >>>> http://www.candelatech.com/~greearb/debug.tgz >>>> >>> >>> The trace shows that __netif_receive_skb() is grabbing an >>> rcu_read_lock() but never releasing it. But I don't see any possible way >>> that can be true in the code. >>> >>> Can you apply the following patch and run the trace again. I'd like to >>> see if the code is going in the path I expect it is. >> >> I'll look at this in detail tomorrow. I have a few patches in dev.c code, maybe >> I merged something badly.... > > I wish you told me that in the beginning. That you modified the core > code. In that case I would have asked to see your modifications before > anything else. > > I'm 99% sure that the bug is in your modifications. I'm sorry, I tried to make that clear. My tree is here, minus a few debugging patches related to this bug: http://dmz2.candelatech.com/git/gitweb.cgi?p=linux-3.7.dev.y/.git;a=summary It's rebased on top of 3.7.6. The wanlink module I'm using is outside the tree. I recently decided to release this as GPL, so ignore any conflicting copyright notices to the contrary in the code: http://www.candelatech.com/~greearb/wanlink.tgz The wanlink module is a network impairment tool that acts like a 2-port bridge. In my current test case, I'm bridging about 300Mbps of traffic across two ethernet ports. It blows up immediately after starting the emulation. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com