From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH] mm: memcontrol: Let mem_cgroup_move_account() have effect only if MMU enabled Date: Wed, 4 Mar 2015 12:40:56 -0500 Message-ID: <20150304174056.GA20376@phnom.home.cmpxchg.org> References: <54F4E739.6040805@qq.com> <20150303134524.GE2409@dhcp22.suse.cz> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20150303134524.GE2409-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Michal Hocko Cc: Chen Gang <762976180-9uewiaClKEY@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Andrew Morton , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" On Tue, Mar 03, 2015 at 02:45:24PM +0100, Michal Hocko wrote: > On Tue 03-03-15 06:42:01, Chen Gang wrote: > > When !MMU, it will report warning. The related warning with allmodconfig > > under c6x: > > Does it even make any sense to enable CONFIG_MEMCG when !CONFIG_MMU? > Is anybody using this configuration and is it actually usable? My > knowledge about CONFIG_MMU is close to zero so I might be missing > something but I do not see a point into fixing compile warnings when > the whole subsystem is not usable in the first place. It's very limited, and anonymous memory is not even charged right now, even though it could be -- see nommu.c::do_mmap_private(). But there is nothing inherent in the memcg functionality that would require an MMU I guess, except for these ridiculous charge moving pte walkers. > > Signed-off-by: Chen Gang Acked-by: Johannes Weiner