From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759535AbYD3JIs (ORCPT ); Wed, 30 Apr 2008 05:08:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754953AbYD3JIi (ORCPT ); Wed, 30 Apr 2008 05:08:38 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:48813 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755559AbYD3JIh (ORCPT ); Wed, 30 Apr 2008 05:08:37 -0400 Subject: Re: [RFC][PATCH 2/5] Container Freezer: Make refrigerator always available From: Matt Helsley To: Linus Torvalds Cc: Pavel Machek , "Rafael J. Wysocki" , Linux-Kernel , Cedric Le Goater , Paul Menage , Oren Laadan , linux-pm@lists.linux-foundation.org, Linux Containers In-Reply-To: <20080425110456.GF14903@elf.ucw.cz> References: <20080424064756.643890130@us.ibm.com> <20080424064757.227289200@us.ibm.com> <20080425110456.GF14903@elf.ucw.cz> Content-Type: text/plain Organization: IBM Linux Technology Center Date: Wed, 30 Apr 2008 02:08:29 -0700 Message-Id: <1209546509.6095.133.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.12.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2008-04-25 at 13:04 +0200, Pavel Machek wrote: > Hi! > > > Now that the TIF_FREEZE flag is available in all architectures, > > extract the refrigerator() and freeze_task() from kernel/power/process.c > > and make it available to all. > > > > The refrigerator() can now be used in a control group subsystem > > implementing a control group freezer. > > > > Signed-off-by: Cedric Le Goater > > Signed-off-by: Matt Helsley > > Tested-by: Matt Helsley > > There's no problem with doing this... but you should get some debate > (with Linus?) whether using freezer for cgroups is sane. When that is OK, I've sent this reply directly to Linus. Hopefully this time he'll let us know... One potential mitigating factor: I don't think we need the full freezer for checkpoint/restart. Right now, because it shares code with "power management" it's convenient to reuse the freezer. I'm hopeful that once the freezer is no longer necessary for power management some code paths can be simplified since I don't think checkpoint/restart requires freezing kernel threads. > done, there's no problem with this going in, probably through rafael's > patch queue. OK, if all goes well then I'll send the next round to Rafael and Cc the rest. If anyone currently on Cc doesn't care to see that feel free to let me know. > (The first patch -- add freezer for all archs -- is probably > reasonably to go in ASAP, through akpm or something...) > Pavel Well, that should only go in if the subsequent patches go in, correct? Also, since to the best of my knowledge this flag hasn't been in every arch, I'm wondering if I should Cc arch maintainers? Cheers, -Matt Helsley