From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755238AbaIKOLB (ORCPT ); Thu, 11 Sep 2014 10:11:01 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:51020 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507AbaIKOLA (ORCPT ); Thu, 11 Sep 2014 10:11:00 -0400 Date: Thu, 11 Sep 2014 16:10:51 +0200 From: Michal Hocko To: "Rafael J. Wysocki" Cc: Tejun Heo , Cong Wang , LKML , David Rientjes , Andrew Morton Subject: Re: [Patch v4 1/2] freezer: check OOM kill while being frozen Message-ID: <20140911141051.GK22042@dhcp22.suse.cz> References: <1409869842-10807-1-git-send-email-xiyou.wangcong@gmail.com> <2362560.tfnxFWQpxu@vostro.rjw.lan> <20140911140448.GJ22042@dhcp22.suse.cz> <1943936.s0DGHUisGb@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1943936.s0DGHUisGb@vostro.rjw.lan> 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 On Thu 11-09-14 16:26:56, Rafael J. Wysocki wrote: > On Thursday, September 11, 2014 04:04:48 PM Michal Hocko wrote: > > On Thu 11-09-14 16:17:56, Rafael J. Wysocki wrote: > > [...] > > > And I'm still wondering if the OOM killer may be made avoid killing frozen > > > tasks. > > > > This is really tricky. OOM killer aims at the biggest memory hog. We > > shouldn't ignore it just because it hides into the fridge... So even > > if we "fix" oom killer to ignore frozen tasks (which is inherently > > racy btw.) then we have a potential problem of freezer abuse (e.g. in > > container environments). So I strongly believe that the OOM killer has > > to be able to kill a frozen tasks. > > OK > > Is the OOM killer the only place where TIF_MEMDIE is set? Yes. To be precise, lowmemorykiller (staging android thingy), global OOM killer and memcg OOM killer. Any other users would be an abuse. -- Michal Hocko SUSE Labs