From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755986Ab2JVSdq (ORCPT ); Mon, 22 Oct 2012 14:33:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62561 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755744Ab2JVSdp (ORCPT ); Mon, 22 Oct 2012 14:33:45 -0400 Date: Mon, 22 Oct 2012 20:34:53 +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: <20121022183453.GA24687@redhat.com> References: <1350426526-14254-1-git-send-email-tj@kernel.org> <1350426526-14254-5-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1350426526-14254-5-git-send-email-tj@kernel.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 10/16, Tejun Heo wrote: > > cgroup_freezer doesn't transition from FREEZING to FROZEN if the > cgroup contains PF_NOFREEZE tasks or tasks sleeping with > PF_FREEZER_SKIP set. And thus the patch looks like another bugfix to me. Just one question, and this question is offtopic again, > Only kernel tasks can be non-freezable (PF_NOFREEZE) 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(). Oleg. 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: Mon, 22 Oct 2012 20:34:53 +0200 Message-ID: <20121022183453.GA24687@redhat.com> References: <1350426526-14254-1-git-send-email-tj@kernel.org> <1350426526-14254-5-git-send-email-tj@kernel.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <1350426526-14254-5-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@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 10/16, Tejun Heo wrote: > > cgroup_freezer doesn't transition from FREEZING to FROZEN if the > cgroup contains PF_NOFREEZE tasks or tasks sleeping with > PF_FREEZER_SKIP set. And thus the patch looks like another bugfix to me. Just one question, and this question is offtopic again, > Only kernel tasks can be non-freezable (PF_NOFREEZE) 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(). Oleg.