From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756903AbXKNV40 (ORCPT ); Wed, 14 Nov 2007 16:56:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763239AbXKNV4F (ORCPT ); Wed, 14 Nov 2007 16:56:05 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:46435 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759906AbXKNV4D (ORCPT ); Wed, 14 Nov 2007 16:56:03 -0500 Subject: Re: [PATCH] Hibernation: Fix lockdep report (v2) From: Peter Zijlstra To: Pavel Machek Cc: "Rafael J. Wysocki" , Andrew Morton , Johannes Berg , LKML , pm list In-Reply-To: <20071114224200.GB7367@ucw.cz> References: <200711142225.58033.rjw@sisk.pl> <20071114224200.GB7367@ucw.cz> Content-Type: text/plain Date: Wed, 14 Nov 2007 22:54:33 +0100 Message-Id: <1195077273.22457.7.camel@lappy> Mime-Version: 1.0 X-Mailer: Evolution 2.12.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2007-11-14 at 22:42 +0000, Pavel Machek wrote: > On Wed 2007-11-14 22:25:57, Rafael J. Wysocki wrote: > > [Andrew, please consider this as 2.6.24 material, thanks.] > > --- > > From: Johannes Berg > > > > Lockdep reports a circular locking dependency in the hibernate code > > because > > - during system boot hibernate code (from an initcall) locks pm_mutex > > and then a sysfs buffer mutex via name_to_dev_t > > - during regular operation hibernate code locks pm_mutex under a > > sysfs buffer mutex because it's called from sysfs methods. > > > > The deadlock can never happen because during initcall invocation nothing > > can write to sysfs yet. This removes the lockdep report by marking the > > initcall locking as being in a different class. > > > > Signed-off-by: Johannes Berg > > Cc: Alan Stern > > Cc: Peter Zijlstra I guess mine got lost too :-) Acked-by: Peter Zijlstra > > Cc: Pavel Machek > > ACK... >