From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753976Ab0HYO10 (ORCPT ); Wed, 25 Aug 2010 10:27:26 -0400 Received: from hera.kernel.org ([140.211.167.34]:45817 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752014Ab0HYO1X (ORCPT ); Wed, 25 Aug 2010 10:27:23 -0400 Message-ID: <4C752704.1030806@kernel.org> Date: Wed, 25 Aug 2010 16:21:56 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.8) Gecko/20100802 Thunderbird/3.1.2 MIME-Version: 1.0 To: Johannes Berg CC: lkml Subject: Re: [PATCH] workqueue: fix cwq->nr_active underflow References: <4C74D9E4.5070403@kernel.org> <1282727501.3685.7.camel@jlt3.sipsolutions.net> <4C74DE62.6040208@kernel.org> <1282746326.3667.8.camel@jlt3.sipsolutions.net> In-Reply-To: <1282746326.3667.8.camel@jlt3.sipsolutions.net> X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 25 Aug 2010 14:27:18 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/25/2010 04:25 PM, Johannes Berg wrote: > On Wed, 2010-08-25 at 11:12 +0200, Tejun Heo wrote: > >> Yeap, without the fix patch applied, that should confirm that we're >> seeing the same failure, and with the patch applied, you can add a >> printk in the else part of !delayed check in cwq_dec_nr_in_flight(). >> If the printk triggers and later rmmod dosen't trigger BUG_ON(), we >> can be fairly sure the problem is fixed. > > Unfortunately, I haven't been able to trigger either code path today. > I'll happily believe that this was the problem though, and will just let > you know if I run into it again, I'm keeping the debug patch for now. > It's certainly a valid fix regardless of whether I can reproduce the > problem or not. Thanks. I'll push it to Linus tomorrow. -- tejun