From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932347AbaDVNVI (ORCPT ); Tue, 22 Apr 2014 09:21:08 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39292 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755844AbaDVNVF (ORCPT ); Tue, 22 Apr 2014 09:21:05 -0400 Date: Tue, 22 Apr 2014 15:21:02 +0200 From: Michal Hocko To: Oleg Nesterov Cc: Andrew Morton , Peter Chiang , KAMEZAWA Hiroyuki , Balbir Singh , Johannes Weiner , "ccross@android.com" , "lizefan@huawei.com" , "tj@kernel.org" , "pavel@ucw.cz" , "ebiederm@xmission.com" , "guillaume@morinfr.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 0/2] memcg: mm_update_next_owner() should skip kthreads Message-ID: <20140422132102.GN29311@dhcp22.suse.cz> References: <1397617379-26895-1-git-send-email-pchiang@nvidia.com> <80341664FB79C2419999599F48F738410227327881@HKMAIL01.nvidia.com> <80341664FB79C2419999599F48F738410227327888@HKMAIL01.nvidia.com> <20140416135741.GA9407@redhat.com> <80341664FB79C2419999599F48F7384102273279C3@HKMAIL01.nvidia.com> <20140418162359.GA4398@redhat.com> <20140418172631.GA13323@redhat.com> <20140418182444.GB22235@dhcp22.suse.cz> <20140418184441.GA26046@redhat.com> <20140422105228.GJ29311@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140422105228.GJ29311@dhcp22.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 On Tue 22-04-14 12:52:28, Michal Hocko wrote: > On Fri 18-04-14 20:44:41, Oleg Nesterov wrote: [...] > > I do not even understand why do we have CONFIG_MM_OWNER, perhaps it should > > die? > > I have to dig into history to check why it has been introduced in the > first place. It might be possible it is not relevant anymore. There didn't seem to be any other user of CONFIG_MM_OWNER outside of MEMCG so it seems that a separate config option seems like an overkill. Regarding the mm->owner itself it is hard to live without it at the moment. Most of the charging places do charge the current task_struct but there are some that rely on mm and we would need mm->task mapping. The last obstacle would be threads migration but that one should go away with unified hierarchy AFAIR. -- Michal Hocko SUSE Labs