Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933409AbYBUBLA (ORCPT ); Wed, 20 Feb 2008 20:11:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755940AbYBUBKv (ORCPT ); Wed, 20 Feb 2008 20:10:51 -0500 Received: from cavan.codon.org.uk ([78.32.9.130]:43458 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755159AbYBUBKt (ORCPT ); Wed, 20 Feb 2008 20:10:49 -0500 Date: Thu, 21 Feb 2008 01:10:32 +0000 From: Matthew Garrett To: Nigel Cunningham Cc: Jesse Barnes , Linus Torvalds , "Rafael J. Wysocki" , Jeff Chua , lkml , Dave Airlie , linux-acpi@vger.kernel.org, suspend-devel List , Greg KH Message-ID: <20080221011032.GA30606@srcf.ucam.org> References: <200802201241.30952.jesse.barnes@intel.com> <200802201344.11643.jesse.barnes@intel.com> <47BCAD6E.9080704@nigel.suspend2.net> <20080221001357.GA29796@srcf.ucam.org> <47BCC866.9000102@nigel.suspend2.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47BCC866.9000102@nigel.suspend2.net> User-Agent: Mutt/1.5.12-2006-07-14 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: mjg59@codon.org.uk Subject: Re: 2.6.25-rc2 System no longer powers off after suspend-to-disk. Screen becomes green. X-SA-Exim-Version: 4.2.1 (built Tue, 20 Jun 2006 01:35:45 +0000) X-SA-Exim-Scanned: Yes (on vavatch.codon.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2167 Lines: 41 On Thu, Feb 21, 2008 at 11:40:06AM +1100, Nigel Cunningham wrote: > Matthew Garrett wrote: > >No, with a freezer-based model you can basically *never* suspend to > >anything related to FUSE or a userspace USB device or anything involving > >userspace iSCSI initiators or whatever. Sure, there are cases where > >moving away from the current model doesn't buy you anything, but that > >doesn't mean that the current model is a good thing. It's not. The > >freezer is a fundamentally broken concept. > > Putting drivers and filesystems in userspace is the fundamentally broken > concept. Not just when it comes to the freezer. The whole idea is > inherently racy. You can draw silly diagrams about how the freezer > supposedly works in LCA slides and spread FUD as much as you like. In > the end, though, it's not nearly as hit-and-miss as you say, and > replacing the freezer with a kexec based freezer is only going to create > as many problems as it removes. I'm really not interested in debating the matter. There are all sorts of potential uses for the freezer, but hibernation isn't one of them. We *need* to get rid of the freezer for suspend to RAM (because a band-aid to ensure atomicity is kind of pointless when the operation you're entering is inherently atomic), and once all the drivers are able to deal with that then it's trivial to get rid of it for hibernation as well. Arguing that the reality of userspace drivers is broken doesn't help here. It's what we have to work with. > >You're looking at a tiny amount of memory when compared to current > >systems. It's really not a problem. > > Please, quantify 'tiny'. In embedded, 5MB can be too much. I've worked > on embedded solutions. I'm not pulling problems out of thin air. Then the in-kernel solution has already lost anyway, and I'm desperately unconcerned about out of tree stuff. -- Matthew Garrett | mjg59@srcf.ucam.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/