From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: KAMEZAWA Hiroyuki
<kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Cc: Linux Kernel
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org"
<linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org>,
"cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>,
Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
Frederic Weisbecker
<fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>,
Han Ying <yinghan-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
"Aneesh Kumar K.V"
<aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
kamezawa.hiroyuki-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
Subject: Re: [RFC][PATCH 7/9 v2] cgroup: avoid attaching task to a cgroup under rmdir()
Date: Fri, 27 Apr 2012 13:33:36 -0700 [thread overview]
Message-ID: <20120427203336.GM26595@google.com> (raw)
In-Reply-To: <20120427203159.GL26595-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
On Fri, Apr 27, 2012 at 01:31:59PM -0700, Tejun Heo wrote:
> On Fri, Apr 27, 2012 at 03:02:22PM +0900, KAMEZAWA Hiroyuki wrote:
> > attach_task() is done under cgroup_mutex() but ->pre_destroy() callback
> > in rmdir() isn't called under cgroup_mutex().
> >
> > It's better to avoid attaching a task to a cgroup which
> > is under pre_destroy(). Considering memcg, the attached task may
> > increase resource usage after memcg's pre_destroy() confirms that
> > memcg is empty. This is not good.
> >
> > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
>
> Hmm... once memcg's pre_destroy() can't fail, I think what we should
> do is marking a cgroup DEAD before calling pre_destroy() and the
> existing cgroup_is_removed() check should be enough. Patches upto
> this point already make ->pre_destroy() not fail, right?
Ooh, I was confused about patch order. This patch, probably with the
update suggested by Frederic looks good as an interim solution for
now.
Thanks.
--
tejun
next prev parent reply other threads:[~2012-04-27 20:33 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-27 5:45 [RFC][PATCH 0/7 v2] memcg: prevent failure in pre_destroy() KAMEZAWA Hiroyuki
2012-04-27 5:51 ` [RFC][PATCH 2/7 v2] memcg: fix error code in hugetlb_force_memcg_empty() KAMEZAWA Hiroyuki
2012-04-30 8:49 ` Aneesh Kumar K.V
2012-04-27 5:54 ` [RFC][PATCH 4/7 v2] memcg: use res_counter_uncharge_until in move_parent KAMEZAWA Hiroyuki
2012-04-27 17:16 ` Glauber Costa
[not found] ` <4F9AD455.9030306-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2012-04-27 18:26 ` Ying Han
2012-04-27 20:11 ` Glauber Costa
2012-04-27 23:58 ` Hiroyuki Kamezawa
[not found] ` <4F9A34B2.8080103-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 18:20 ` Tejun Heo
2012-04-27 23:59 ` Hiroyuki Kamezawa
2012-04-30 9:00 ` Aneesh Kumar K.V
2012-04-27 5:58 ` [RFC][PATCH 5/9 v2] move charges to root at rmdir if use_hierarchy is unset KAMEZAWA Hiroyuki
[not found] ` <4F9A359C.10107-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 19:12 ` Ying Han
[not found] ` <CALWz4ixHGCqfWh1U+JyiJWTkGmCDtXQy1vbHRjrHaU_pOgGuBw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-28 0:01 ` Hiroyuki Kamezawa
2012-04-30 9:07 ` Aneesh Kumar K.V
[not found] ` <4F9A327A.6050409-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 5:49 ` [RFC][PATCH 1/7 v2] temporal compile-fix in linux-next KAMEZAWA Hiroyuki
[not found] ` <4F9A3364.4090009-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-30 8:47 ` Aneesh Kumar K.V
2012-04-27 5:53 ` [RFC][PATCH 3/7 v2] res_counter: add res_counter_uncharge_until() KAMEZAWA Hiroyuki
2012-04-27 17:08 ` Glauber Costa
[not found] ` <4F9AD28C.60508-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2012-04-27 23:51 ` Hiroyuki Kamezawa
[not found] ` <4F9A343F.7020409-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 18:18 ` Tejun Heo
[not found] ` <20120427181840.GH26595-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-04-27 23:51 ` Hiroyuki Kamezawa
2012-04-27 6:00 ` [RFC][PATCH 6/9 v2] memcg: don't uncharge in mem_cgroup_move_account KAMEZAWA Hiroyuki
2012-04-27 6:04 ` [RFC][PATCH 8/9 v2] cgroup: avoid creating new cgroup under a cgroup being destroyed KAMEZAWA Hiroyuki
2012-04-27 17:18 ` Glauber Costa
[not found] ` <4F9A36DE.30301-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 20:40 ` Tejun Heo
2012-04-27 20:41 ` Tejun Heo
[not found] ` <20120427204035.GN26595-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-04-28 0:20 ` Hiroyuki Kamezawa
2012-04-28 2:00 ` Tejun Heo
2012-04-28 9:31 ` Hiroyuki Kamezawa
2012-04-28 21:31 ` Tejun Heo
2012-04-27 18:16 ` [RFC][PATCH 0/7 v2] memcg: prevent failure in pre_destroy() Tejun Heo
[not found] ` <20120427181642.GG26595-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-04-27 23:48 ` Hiroyuki Kamezawa
[not found] ` <CABEgKgrir3PBGqm_9FmYsZTiFqsZ=Cdt5iZDu5WcOHPtZuEbFg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-28 16:13 ` Michal Hocko
[not found] ` <20120428161358.GA13010-VqjxzfR4DlwKmadIfiO5sKVXKuFTiq87@public.gmane.org>
2012-04-29 6:03 ` Michal Hocko
2012-04-27 6:02 ` [RFC][PATCH 7/9 v2] cgroup: avoid attaching task to a cgroup under rmdir() KAMEZAWA Hiroyuki
2012-04-27 10:39 ` Frederic Weisbecker
[not found] ` <20120427103927.GA3514-oHC15RC7JGTpAmv0O++HtFaTQe2KTcn/@public.gmane.org>
2012-04-28 0:06 ` Hiroyuki Kamezawa
[not found] ` <4F9A366E.9020307-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 20:31 ` Tejun Heo
[not found] ` <20120427203159.GL26595-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-04-27 20:33 ` Tejun Heo [this message]
2012-04-27 6:06 ` [RFC][PATCH 9/9 v2] memcg: never return error at pre_destroy() KAMEZAWA Hiroyuki
2012-04-27 21:28 ` Ying Han
[not found] ` <CALWz4iyiM-CFgVaHiE1Lgd1ZwJzHwY3tx9XX6HeDPUV_wVPAtQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-28 0:25 ` Hiroyuki Kamezawa
2012-04-30 17:02 ` Ying Han
2012-05-01 22:28 ` Suleiman Souhlal
[not found] ` <CABCjUKBhNkGf2QHzONMod3HmHgS-HxB5hUxpfJFHUG-eBkYBRw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-05-02 3:34 ` Hiroyuki Kamezawa
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