From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: Re: [PATCH 4/7] cgroup_freezer: don't stall transition to FROZEN for PF_NOFREEZE or PF_FREEZER_SKIP tasks Date: Tue, 23 Oct 2012 17:55:33 +0200 Message-ID: <20121023155533.GC16201@redhat.com> References: <1350426526-14254-1-git-send-email-tj@kernel.org> <1350426526-14254-5-git-send-email-tj@kernel.org> <20121022183453.GA24687@redhat.com> <20121022211822.GF5951@atj.dyndns.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20121022211822.GF5951-OlzNCW9NnSVy/B6EtB590w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: rjw-KKrjLPT3xs0@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On 10/22, Tejun Heo wrote: > > On Mon, Oct 22, 2012 at 08:34:53PM +0200, Oleg Nesterov wrote: > > > > Hmm. We seem to "leak" PF_NOFREEZE if a kernel thread execs? > > Perhaps do_execve_common() should do set_freezable() before return. > > > > Or, at least, simply clear this flag along with PF_KTHREAD in > > flush_old_exec(). > > Ooh, ouch, definitely. We should clear that. Can you please make a > patch? Sure... but what do you think is better? I'd prefer to simply clear PF_NOFREEZE (without set_freezable), but obviously this doesn't look exactly right from cgroup_freezer pov. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933115Ab2JWPy0 (ORCPT ); Tue, 23 Oct 2012 11:54:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6484 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754833Ab2JWPyZ (ORCPT ); Tue, 23 Oct 2012 11:54:25 -0400 Date: Tue, 23 Oct 2012 17:55:33 +0200 From: Oleg Nesterov To: Tejun Heo Cc: rjw@sisk.pl, linux-kernel@vger.kernel.org, lizefan@huawei.com, containers@lists.linux-foundation.org, cgroups@vger.kernel.org Subject: Re: [PATCH 4/7] cgroup_freezer: don't stall transition to FROZEN for PF_NOFREEZE or PF_FREEZER_SKIP tasks Message-ID: <20121023155533.GC16201@redhat.com> References: <1350426526-14254-1-git-send-email-tj@kernel.org> <1350426526-14254-5-git-send-email-tj@kernel.org> <20121022183453.GA24687@redhat.com> <20121022211822.GF5951@atj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121022211822.GF5951@atj.dyndns.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/22, Tejun Heo wrote: > > On Mon, Oct 22, 2012 at 08:34:53PM +0200, Oleg Nesterov wrote: > > > > Hmm. We seem to "leak" PF_NOFREEZE if a kernel thread execs? > > Perhaps do_execve_common() should do set_freezable() before return. > > > > Or, at least, simply clear this flag along with PF_KTHREAD in > > flush_old_exec(). > > Ooh, ouch, definitely. We should clear that. Can you please make a > patch? Sure... but what do you think is better? I'd prefer to simply clear PF_NOFREEZE (without set_freezable), but obviously this doesn't look exactly right from cgroup_freezer pov. Oleg.