From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757049AbXGEMD5 (ORCPT ); Thu, 5 Jul 2007 08:03:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757946AbXGEMDl (ORCPT ); Thu, 5 Jul 2007 08:03:41 -0400 Received: from crystal.sipsolutions.net ([195.210.38.204]:43118 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760957AbXGEMDk (ORCPT ); Thu, 5 Jul 2007 08:03:40 -0400 Message-Id: <20070705110744.564273000@sipsolutions.net> User-Agent: quilt/0.46-1 Date: Thu, 05 Jul 2007 13:07:44 +0200 From: Johannes Berg To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Oleg Nesterov , Ingo Molnar , Peter Zijlstra Subject: [PATCH 0/2] workqueue lockup debugging Mime-Version: 1.0 X-Mailer: Evolution 2.10.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I recently experienced a lockup in the wireless code due to the scenario described in patch 1 and wanted to have lockdep warn about such scenarios as a way to catch such bugs in other subsystems as well as to make sure we wouldn't get such things ever again. In discussions with Oleg and Ingo it turned out that there's another possible deadlock with the now-recommended API of cancel_work_sync() and I also found a way to make lockdep catch that; it is addressed by patch 2. Ingo thinks this could also have caught a similar lockup in the DVB subsystem (I haven't found a patch for it yet) and would like to see it in .23 early on. johannes