From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH v2] memcg: debugging facility to access dangling memcgs. Date: Tue, 4 Dec 2012 11:40:42 +0400 Message-ID: <50BDA8FA.4060404@parallels.com> References: <1354541048-12597-1-git-send-email-glommer@parallels.com> <20121203154420.661f8e28.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121203154420.661f8e28.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Tejun Heo , Michal Hocko , kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, Johannes Weiner On 12/04/2012 03:44 AM, Andrew Morton wrote: > On Mon, 3 Dec 2012 17:24:08 +0400 > Glauber Costa wrote: > >> If memcg is tracking anything other than plain user memory (swap, tcp >> buf mem, or slab memory), it is possible - and normal - that a reference >> will be held by the group after it is dead. Still, for developers, it >> would be extremely useful to be able to query about those states during >> debugging. >> >> This patch provides a debugging facility in the root memcg, so we can >> inspect which memcgs still have pending objects, and what is the cause >> of this state. > > As this is a developer-only thing, I suggest that we should avoid > burdening mainline with it. How about we maintain this in -mm (and > hence in -next and mhocko's memcg tree) until we no longer see a need > for it? > I am absolutely fine with that.