Return-path: Received: from mx1.redhat.com ([66.187.233.31]:47925 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751993AbXF3IG0 (ORCPT ); Sat, 30 Jun 2007 04:06:26 -0400 Subject: Re: [RFC/PATCH] debug workqueue deadlocks with lockdep From: Ingo Molnar To: Johannes Berg Cc: Arjan van de Ven , Linux Kernel list , linux-wireless , Peter Zijlstra , Oleg Nesterov , mingo@elte.hu, Thomas Sattler In-Reply-To: <1183052001.4089.2.camel@johannes.berg> References: <1182969638.4769.56.camel@johannes.berg> <1183048429.4089.1.camel@johannes.berg> <1183052001.4089.2.camel@johannes.berg> Content-Type: text/plain Date: Sat, 30 Jun 2007 10:05:28 +0200 Message-Id: <1183190728.7932.43.camel@earth4> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, 2007-06-28 at 19:33 +0200, Johannes Berg wrote: > No, that's not right either, but Arjan just helped me a bit with how > lockdep works and I think I have the right idea now. Ignore this for > now, I'll send a new patch in a few days. ok. But in general, this is a very nice idea! i've Cc:-ed Oleg. Oleg, what do you think? I think we should keep all the workqueue APIs specified in a form that makes them lockdep coverable like Johannes did. This debug mechanism could have helped with the recent DVB lockup that Thomas Sattler reported. Ingo