From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753075Ab1G2VXb (ORCPT ); Fri, 29 Jul 2011 17:23:31 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:34796 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753044Ab1G2VX3 (ORCPT ); Fri, 29 Jul 2011 17:23:29 -0400 From: "Rafael J. Wysocki" To: Pavel Machek Subject: Re: [linux-pm] better oopsing when frozen Date: Fri, 29 Jul 2011 22:27:54 +0200 User-Agent: KMail/1.13.6 (Linux/3.0.0+; KDE/4.6.0; x86_64; ; ) Cc: Oliver Neukum , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Andrew Morton References: <201107251043.19932.oneukum@suse.de> <20110729195430.GB1720@ucw.cz> In-Reply-To: <20110729195430.GB1720@ucw.cz> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201107292227.54948.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, July 29, 2011, Pavel Machek wrote: > On Mon 2011-07-25 10:43:19, Oliver Neukum wrote: > > Hi Rafael, > > > > I had a problem with the kernel stopping the machine forever because I got an > > oops while tasks were frozen. It seems to me that we should thaw when this > > happens. How about this approach? > > Danger, Will Robinson. You must not write to the filesystems after > hibernation started. By thawing, you may do just that. > > It should be safe to thaw as long as final suspend signature is not > on disk and will not be written there. This only applies to hibernation and only when we're going to restore from the image the presumably hasn't been saved yet, right? However, there's another problem I didn't think of before. Namely, we cannot thaw tasks before resuming devices in case we've already suspended them, because that will defeat the very purpose of the freezing in the first place. Thanks, Rafael