From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755243AbbCBR61 (ORCPT ); Mon, 2 Mar 2015 12:58:27 -0500 Received: from mail-wi0-f182.google.com ([209.85.212.182]:42219 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753719AbbCBR6Z (ORCPT ); Mon, 2 Mar 2015 12:58:25 -0500 Date: Mon, 2 Mar 2015 18:58:21 +0100 From: Michal Hocko To: Johannes Weiner Cc: Andrew Morton , Vladimir Davydov , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch] memcg: disable hierarchy support if bound to the legacy cgroup hierarchy Message-ID: <20150302175821.GA18345@dhcp22.suse.cz> References: <1425317939-13305-1-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1425317939-13305-1-git-send-email-hannes@cmpxchg.org> 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 Mon 02-03-15 12:38:59, Johannes Weiner wrote: > From: Vladimir Davydov > > If the memory cgroup controller is initially mounted in the scope of the > default cgroup hierarchy and then remounted to a legacy hierarchy, it > will still have hierarchy support enabled, which is incorrect. We should > disable hierarchy support if bound to the legacy cgroup hierarchy. > > Signed-off-by: Vladimir Davydov > Signed-off-by: Johannes Weiner I had this one on the radar but I wasn't sure about the first cgroup part so I haven't acked it. Once Tejun picked it up this one is good as well. Acked-by: Michal Hocko > --- > mm/memcontrol.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > Andrew, could you please pick this up for 4.0? I don't think it's > urgent enough for -stable, though. Thanks! > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 0c86945bcc9a..68d4890fc4bd 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -5238,7 +5238,9 @@ static void mem_cgroup_bind(struct cgroup_subsys_state *root_css) > * on for the root memcg is enough. > */ > if (cgroup_on_dfl(root_css->cgroup)) > - mem_cgroup_from_css(root_css)->use_hierarchy = true; > + root_mem_cgroup->use_hierarchy = true; > + else > + root_mem_cgroup->use_hierarchy = false; > } > > static u64 memory_current_read(struct cgroup_subsys_state *css, > -- > 2.3.0 > -- Michal Hocko SUSE Labs