From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758762AbXGEAC4 (ORCPT ); Wed, 4 Jul 2007 20:02:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756074AbXGEACt (ORCPT ); Wed, 4 Jul 2007 20:02:49 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:41191 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756046AbXGEACs (ORCPT ); Wed, 4 Jul 2007 20:02:48 -0400 Date: Thu, 5 Jul 2007 02:02:35 +0200 From: Pavel Machek To: Miklos Szeredi Cc: oliver@neukum.org, linux-pm@lists.linux-foundation.org, benh@kernel.crashing.org, nigel@nigel.suspend2.net, mjg59@srcf.ucam.org, linux-kernel@vger.kernel.org Subject: Re: [linux-pm] Re: [PATCH] Remove process freezer from suspend to RAM pathway Message-ID: <20070705000235.GD2719@elf.ucw.cz> References: <20070703042916.GA17240@srcf.ucam.org> <200707030944.18702.oliver@neukum.org> <200707031307.41366.oliver@neukum.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > > I don't claim to know anything about how STR or hibernate works, but > > > neither seem to have any problem with I/O on the fuse device "racing" > > > with them. > > > > The problem is not with fuse. The problem is generic in nature. > > > > If you remove the freezer, user space remains active until the last CPU > > goes into suspend. It can do syscalls. Or do you know a clean way to exempt > > only the tasks fuse might use? > > You are talking about hibernate, right? Suspending (to ram) is > instantaneous, in that _after_ suspend no CPU is active obviously. No, suspend to ram is not instantaneous. We may have 16 cpus, and we may have 250 disks that need to be spun down. That takes time, and is really not atomic operation. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html