From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752585AbXCUCrH (ORCPT ); Tue, 20 Mar 2007 22:47:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752571AbXCUCrH (ORCPT ); Tue, 20 Mar 2007 22:47:07 -0400 Received: from e32.co.us.ibm.com ([32.97.110.150]:42449 "EHLO e32.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752585AbXCUCrG (ORCPT ); Tue, 20 Mar 2007 22:47:06 -0400 Date: Tue, 20 Mar 2007 19:47:01 -0700 From: sukadev@us.ibm.com To: "Eric W. Biederman" Cc: "Rafael J. Wysocki" , Jiri Slaby , Andrew Morton , Pavel Machek , linux-pm@lists.osdl.org, linux-kernel@vger.kernel.org, Oleg Nesterov Subject: Re: [linux-pm] 2.6.21-rc4-mm1: freezing of processes broken Message-ID: <20070321024701.GC13436@us.ibm.com> References: <20070319205623.299d0378.akpm@linux-foundation.org> <46004B02.7020407@gmail.com> <200703202206.38168.rjw@sisk.pl> <200703210149.33240.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i X-Operating-System: Linux 2.0.32 on an i486 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Eric W. Biederman [ebiederm@xmission.com] wrote: | "Rafael J. Wysocki" writes: | | > On Tuesday, 20 March 2007 22:06, Rafael J. Wysocki wrote: | >> On Tuesday, 20 March 2007 21:58, Jiri Slaby wrote: | >> > Rafael J. Wysocki napsal(a): | >> > > Actually, the problem is 100% reproducible on my system too and I doubt | > it's | >> > > caused by the recent freezer patches. | >> > | >> > I don't know what exactly do you mean by recent, but 2.6.21-rc3-mm2 works | >> > for me. | >> | >> Thanks for the confirmation. | >> | >> The patches I was talking about had already been in 2.6.21-rc3-mm2, so the | >> reason of this failure must be different. | > | > Bisection shows that the freezing of processes has been broken by one of the | > patches: | > | > remove-the-likelypid-check-in-copy_process.patch | | Grr. Oleg's review of remove-the-likelypid-check-in-copy-process | showed it to be questionable (and it was just an optimization) | so we can get rid of that one easily. | | Although all it did that was really questionable was add | the idle process to the global process list and bump a process | count when we forked the idle process. Not dramatically dangerous | things. | | > use-task_pgrp-task_session-in-copy_process.patch | | As I recall that patch was pretty trivial, and shouldn't have | anything to do with the freezer. The process freezer doesn't care | about pids does it? Yes. I think this one is trivial too. Here is the effective change in copy_process(): - attach_pid(p, PIDTYPE_PGID, find_pid(pgid)); - attach_pid(p, PIDTYPE_SID, find_pid(sid)); + attach_pid(p, PIDTYPE_PGID, task_pgrp(current)); + attach_pid(p, PIDTYPE_SID, task_session(current)); | | Eric