From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758159AbXGHVz5 (ORCPT ); Sun, 8 Jul 2007 17:55:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757323AbXGHVzt (ORCPT ); Sun, 8 Jul 2007 17:55:49 -0400 Received: from gate.crashing.org ([63.228.1.57]:50970 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757202AbXGHVzs (ORCPT ); Sun, 8 Jul 2007 17:55:48 -0400 Subject: Re: [PATCH] Remove process freezer from suspend to RAM pathway From: Benjamin Herrenschmidt To: "Rafael J. Wysocki" Cc: Alan Stern , Kyle Moffett , Nigel Cunningham , Pavel Machek , Matthew Garrett , linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org In-Reply-To: <200707082345.27859.rjw@sisk.pl> References: <200707082115.27363.rjw@sisk.pl> <1183928612.3388.289.camel@localhost.localdomain> <200707082345.27859.rjw@sisk.pl> Content-Type: text/plain Date: Mon, 09 Jul 2007 07:54:48 +1000 Message-Id: <1183931688.3388.316.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2007-07-08 at 23:45 +0200, Rafael J. Wysocki wrote: > > Workqueues are kernel threads and the creator decides if they are going to > freeze. There are only two freezable worqueues in the entire tree right now. That and keventd workqueues... my point is you may well end up with something in a workqueue doing things that should have been blocked after the freeze. > Actaully, I'm perfectly fine with that, as long as each task blocked by the > driver due to suspend has PF_FROZEN (or something similar) set. Then, at > least theoretically, we'll be able to drop the freezer from the suspend code > path and move it after device_suspend() (or the hibernation-specific > equivalent) for hibernation (in that case there shouldn't be a problem with > any task waiting on I/O while the freezer is running ;-)). I don't see the need for a freezer for snapshot but that's a different issue. (stop_machine looks good enough to me). Ben