From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753643Ab0HYOZb (ORCPT ); Wed, 25 Aug 2010 10:25:31 -0400 Received: from he.sipsolutions.net ([78.46.109.217]:33238 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753193Ab0HYOZ3 (ORCPT ); Wed, 25 Aug 2010 10:25:29 -0400 Subject: Re: [PATCH] workqueue: fix cwq->nr_active underflow From: Johannes Berg To: Tejun Heo Cc: lkml In-Reply-To: <4C74DE62.6040208@kernel.org> References: <4C74D9E4.5070403@kernel.org> <1282727501.3685.7.camel@jlt3.sipsolutions.net> <4C74DE62.6040208@kernel.org> Content-Type: text/plain; charset="UTF-8" Date: Wed, 25 Aug 2010 16:25:26 +0200 Message-ID: <1282746326.3667.8.camel@jlt3.sipsolutions.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. johannes