From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx141.postini.com [74.125.245.141]) by kanga.kvack.org (Postfix) with SMTP id 6A8366B004D for ; Mon, 18 Jun 2012 08:46:17 -0400 (EDT) Message-ID: <4FDF227B.3080601@parallels.com> Date: Mon, 18 Jun 2012 16:43:39 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v4 23/25] memcg: propagate kmem limiting information to children References: <1340015298-14133-1-git-send-email-glommer@parallels.com> <1340015298-14133-24-git-send-email-glommer@parallels.com> <4FDF20ED.4090401@jp.fujitsu.com> In-Reply-To: <4FDF20ED.4090401@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Kamezawa Hiroyuki Cc: linux-mm@kvack.org, Pekka Enberg , Cristoph Lameter , David Rientjes , cgroups@vger.kernel.org, devel@openvz.org, linux-kernel@vger.kernel.org, Frederic Weisbecker , Suleiman Souhlal , Pekka Enberg , Michal Hocko , Johannes Weiner On 06/18/2012 04:37 PM, Kamezawa Hiroyuki wrote: > (2012/06/18 19:28), Glauber Costa wrote: >> The current memcg slab cache management fails to present satisfatory hierarchical >> behavior in the following scenario: >> >> -> /cgroups/memory/A/B/C >> >> * kmem limit set at A >> * A and B empty taskwise >> * bash in C does find / >> >> Because kmem_accounted is a boolean that was not set for C, no accounting >> would be done. This is, however, not what we expect. >> > > Hmm....do we need this new routines even while we have mem_cgroup_iter() ? > > Doesn't this work ? > > struct mem_cgroup { > ..... > bool kmem_accounted_this; > atomic_t kmem_accounted; > .... > } > > at set limit > > ....set_limit(memcg) { > > if (newly accounted) { > mem_cgroup_iter() { > atomic_inc(&iter->kmem_accounted) > } > } else { > mem_cgroup_iter() { > atomic_dec(&iter->kmem_accounted); > } > } > > > hm ? Then, you can see kmem is accounted or not by atomic_read(&memcg->kmem_accounted); > Accounted by itself / parent is still useful, and I see no reason to use an atomic + bool if we can use a pair of bits. As for the routine, I guess mem_cgroup_iter will work... It does a lot more than I need, but for the sake of using what's already in there, I can switch to it with no problems. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org