From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758634Ab2C1Rhe (ORCPT ); Wed, 28 Mar 2012 13:37:34 -0400 Received: from e23smtp09.au.ibm.com ([202.81.31.142]:36606 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753377Ab2C1Rhc (ORCPT ); Wed, 28 Mar 2012 13:37:32 -0400 From: "Aneesh Kumar K.V" To: Michal Hocko Cc: linux-mm@kvack.org, mgorman@suse.de, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, aarcange@redhat.com, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH -V4 04/10] memcg: Add HugeTLB extension In-Reply-To: <20120328134020.GG20949@tiehlicka.suse.cz> References: <1331919570-2264-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1331919570-2264-5-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120328134020.GG20949@tiehlicka.suse.cz>User-Agent: Notmuch/0.11.1+346~g13d19c3 (http://notmuchmail.org) Emacs/23.3.1 (x86_64-pc-linux-gnu) Date: Wed, 28 Mar 2012 23:07:14 +0530 Message-ID: <87y5qk1vat.fsf@skywalker.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii x-cbid: 12032808-3568-0000-0000-0000016EEC3B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michal Hocko writes: > On Fri 16-03-12 23:09:24, Aneesh Kumar K.V wrote: > [...] >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 6728a7a..4b36c5e 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c > [...] >> @@ -4887,6 +5013,7 @@ err_cleanup: >> static struct cgroup_subsys_state * __ref >> mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) >> { >> + int idx; >> struct mem_cgroup *memcg, *parent; >> long error = -ENOMEM; >> int node; >> @@ -4929,9 +5056,14 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) >> * mem_cgroup(see mem_cgroup_put). >> */ >> mem_cgroup_get(parent); >> + for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) >> + res_counter_init(&memcg->hugepage[idx], >> + &parent->hugepage[idx]); > > Hmm, I do not think we want to make groups deeper in the hierarchy > unlimited as we cannot reclaim. Shouldn't we copy the limit from the parent? > Still not ideal but slightly more expected behavior IMO. But we should be limiting the child group based on parent's limit only when hierarchy is set right ? > > The hierarchy setups are still interesting and the limitations should be > described in the documentation... > It should behave similar to memcg. ie, if hierarchy is set, then we limit using MIN(parent's limit, child's limit). May be I am missing some of the details of memcg use_hierarchy config. My goal was to keep it similar to memcg. Can you explain why do you think the patch would make it any different ? -aneesh