From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161654AbaKNRzk (ORCPT ); Fri, 14 Nov 2014 12:55:40 -0500 Received: from mail-qg0-f42.google.com ([209.85.192.42]:58573 "EHLO mail-qg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161175AbaKNRzj (ORCPT ); Fri, 14 Nov 2014 12:55:39 -0500 Date: Fri, 14 Nov 2014 12:55:34 -0500 From: Tejun Heo To: Michal Hocko Cc: LKML , linux-mm@kvack.org, linux-pm@vger.kernel.org, Andrew Morton , "\\\"Rafael J. Wysocki\\\"" , David Rientjes , Oleg Nesterov , Cong Wang Subject: Re: [RFC 1/4] OOM, PM: Do not miss OOM killed frozen tasks Message-ID: <20141114175534.GH25889@htj.dyndns.org> References: <20141110163055.GC18373@dhcp22.suse.cz> <1415818732-27712-1-git-send-email-mhocko@suse.cz> <1415818732-27712-2-git-send-email-mhocko@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1415818732-27712-2-git-send-email-mhocko@suse.cz> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Michal. On Wed, Nov 12, 2014 at 07:58:49PM +0100, Michal Hocko wrote: > Also change the return value semantic as the current one is little bit > awkward. There is just one caller (try_to_freeze_tasks) which checks > the return value and it is only interested whether the request was > successful or the task blocks the freezing progress. It is natural to > reflect the success by true rather than false. I don't know about this. It's also customary to return %true when further action needs to be taken. I don't think either is particularly wrong but the flip seems gratuitous. > bool freeze_task(struct task_struct *p) > { > @@ -129,12 +130,20 @@ bool freeze_task(struct task_struct *p) > * normally. > */ > if (freezer_should_skip(p)) > + return true; > + > + /* > + * Do not check freezing state or attempt to freeze a task > + * which has been killed by OOM killer. We are just waiting > + * for the task to wake up and die. Maybe saying sth like "consider the task freezing as ...." is a clearer way to put it? > + */ > + if (!test_tsk_thread_flag(p, TIF_MEMDIE)) > return false; Thanks. -- tejun