From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752326AbaIIUeH (ORCPT ); Tue, 9 Sep 2014 16:34:07 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:49244 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751965AbaIIUeF (ORCPT ); Tue, 9 Sep 2014 16:34:05 -0400 From: "Rafael J. Wysocki" To: Tejun Heo Cc: Michal Hocko , Cong Wang , LKML , David Rientjes , Andrew Morton Subject: Re: [Patch v4 1/2] freezer: check OOM kill while being frozen Date: Tue, 09 Sep 2014 22:53:32 +0200 Message-ID: <2008100.1EF7gjK5Z6@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <20140909164658.GB11748@mtj.dyndns.org> References: <1409869842-10807-1-git-send-email-xiyou.wangcong@gmail.com> <20140909160625.GC4851@dhcp22.suse.cz> <20140909164658.GB11748@mtj.dyndns.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, September 10, 2014 01:46:58 AM Tejun Heo wrote: > Hello, > > On Tue, Sep 09, 2014 at 06:06:25PM +0200, Michal Hocko wrote: > > > Even for userland tasks, try_to_freeze() can currently be anywhere in > > > the kernel. The frequently used ones are few but there are some odd > > > > I always thought that user space tasks can be in the fridge only on the > > way out from the kernel (get_signal_to_deliver). I have quickly greped > > It *can* be anywhere. We used to have some deep in nfs. They got > removed later due to deadlocks but in theory they still can be > anywhere. Well, it would be good to determine the difference between theory and practice in this particular respect, because if in practice it can't be anywhere, we can just set an "every new instance of try_to_freeze() has to be documented" rule (which may not be a bad idea anyway) and disallow people to break things. Rafael