From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx152.postini.com [74.125.245.152]) by kanga.kvack.org (Postfix) with SMTP id 902FF6B0006 for ; Sun, 7 Apr 2013 04:44:31 -0400 (EDT) Message-ID: <516131D7.8030004@huawei.com> Date: Sun, 7 Apr 2013 16:44:07 +0800 From: Li Zefan MIME-Version: 1.0 Subject: Re: [RFC][PATCH 0/7] memcg: make memcg's life cycle the same as cgroup References: <515BF233.6070308@huawei.com> In-Reply-To: <515BF233.6070308@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa , Michal Hocko Cc: linux-mm@kvack.org, LKML , Cgroups , Tejun Heo , KAMEZAWA Hiroyuki , Johannes Weiner Hi, I'm rebasing this patchset against latest linux-next, and it conflicts with "[PATCH v2] memcg: debugging facility to access dangling memcgs." slightly. That is a debugging patch and will never be pushed into mainline, so should I still base this patchset on that debugging patch? Also that patch needs update (and can be simplified) after this patchset: - move memcg_dangling_add() to mem_cgroup_css_offline() - remove memcg->memcg_name, and use cgroup_path() in mem_cgroup_dangling_read()? On 2013/4/3 17:11, Li Zefan wrote: > (I'll be off from my office soon, and I won't be responsive in the following > 3 days.) > > I'm working on converting memcg to use cgroup->id, and then we can kill css_id. > > Now memcg has its own refcnt, so when a cgroup is destroyed, the memcg can > still be alive. This patchset converts memcg to always use css_get/put, so > memcg will have the same life cycle as its corresponding cgroup, and then > it's always safe for memcg to use cgroup->id. > > The historical reason that memcg didn't use css_get in some cases, is that > cgroup couldn't be removed if there're still css refs. The situation has > changed so that rmdir a cgroup will succeed regardless css refs, but won't > be freed until css refs goes down to 0. > > This is an early post, and it's NOT TESTED. I just want to see if the changes > are fine in general. > > btw, after this patchset I think we don't need to free memcg via RCU, because > cgroup is already freed in RCU callback. > > Note this patchset is based on a few memcg fixes I sent (but hasn't been > accepted) > > -- > kernel/cgroup.c | 10 ++++++++ > mm/memcontrol.c | 129 ++++++++++++++++++++++++++++++++++++++------------------------------------------------------- > 2 files changed, 62 insertions(+), 77 deletions(-) > -- 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