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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

WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
	Michal Hocko <mhocko@suse.cz>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Glauber Costa <glommer@parallels.com>,
	Han Ying <yinghan@google.com>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	kamezawa.hiroyuki@gmail.com
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@google.com>

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@jp.fujitsu.com>
> 
> 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

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WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
	Michal Hocko <mhocko@suse.cz>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Glauber Costa <glommer@parallels.com>,
	Han Ying <yinghan@google.com>,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	kamezawa.hiroyuki@gmail.com
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@google.com>

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@jp.fujitsu.com>
> 
> 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

  parent reply	other threads:[~2012-04-27 20:33 UTC|newest]

Thread overview: 116+ 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  5:45 ` KAMEZAWA Hiroyuki
2012-04-27  5:45 ` KAMEZAWA Hiroyuki
     [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
2012-04-27  5:49     ` KAMEZAWA Hiroyuki
2012-04-27  5:49     ` KAMEZAWA Hiroyuki
     [not found]     ` <4F9A3364.4090009-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-30  8:47       ` Aneesh Kumar K.V
2012-04-30  8:47         ` Aneesh Kumar K.V
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  5:53     ` KAMEZAWA Hiroyuki
2012-04-27  5:53     ` KAMEZAWA Hiroyuki
2012-04-27 17:08     ` Glauber Costa
     [not found]       ` <4F9AD28C.60508-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2012-04-27 23:51         ` Hiroyuki Kamezawa
2012-04-27 23:51           ` Hiroyuki Kamezawa
2012-04-27 23:51           ` Hiroyuki Kamezawa
     [not found]     ` <4F9A343F.7020409-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 18:18       ` Tejun Heo
2012-04-27 18:18         ` Tejun Heo
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 23:51             ` Hiroyuki Kamezawa
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  6:00     ` KAMEZAWA Hiroyuki
2012-04-27  6:00     ` 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  6:04     ` KAMEZAWA Hiroyuki
2012-04-27  6:04     ` 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 20:40         ` Tejun Heo
2012-04-27 20:40         ` Tejun Heo
2012-04-27 20:41         ` 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  0:20             ` Hiroyuki Kamezawa
2012-04-28  0:20             ` Hiroyuki Kamezawa
2012-04-28  2:00             ` Tejun Heo
2012-04-28  2:00               ` Tejun Heo
2012-04-28  9:31               ` Hiroyuki Kamezawa
2012-04-28  9:31                 ` Hiroyuki Kamezawa
2012-04-28 21:31                 ` Tejun Heo
2012-04-28 21:31                   ` Tejun Heo
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
2012-04-27 18:16     ` Tejun Heo
2012-04-27 18:16     ` Tejun Heo
     [not found]     ` <20120427181642.GG26595-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-04-27 23:48       ` Hiroyuki Kamezawa
2012-04-27 23:48         ` Hiroyuki Kamezawa
2012-04-27 23:48         ` Hiroyuki Kamezawa
     [not found]         ` <CABEgKgrir3PBGqm_9FmYsZTiFqsZ=Cdt5iZDu5WcOHPtZuEbFg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-28 16:13           ` Michal Hocko
2012-04-28 16:13             ` Michal Hocko
2012-04-28 16:13             ` Michal Hocko
     [not found]             ` <20120428161358.GA13010-VqjxzfR4DlwKmadIfiO5sKVXKuFTiq87@public.gmane.org>
2012-04-29  6:03               ` Michal Hocko
2012-04-29  6:03                 ` Michal Hocko
2012-04-29  6:03                 ` Michal Hocko
2012-04-27  5:51 ` [RFC][PATCH 2/7 v2] memcg: fix error code in hugetlb_force_memcg_empty() KAMEZAWA Hiroyuki
2012-04-27  5:51   ` KAMEZAWA Hiroyuki
2012-04-30  8:49   ` Aneesh Kumar K.V
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  5:54   ` 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 18:26         ` Ying Han
2012-04-27 18:26         ` Ying Han
2012-04-27 20:11         ` Glauber Costa
2012-04-27 23:58       ` Hiroyuki Kamezawa
2012-04-27 23:58         ` Hiroyuki Kamezawa
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 18:20       ` Tejun Heo
2012-04-27 18:20       ` Tejun Heo
2012-04-27 23:59       ` Hiroyuki Kamezawa
2012-04-27 23:59         ` Hiroyuki Kamezawa
2012-04-30  9:00     ` Aneesh Kumar K.V
2012-04-30  9:00       ` Aneesh Kumar K.V
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
2012-04-27  5:58   ` KAMEZAWA Hiroyuki
     [not found]   ` <4F9A359C.10107-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 19:12     ` Ying Han
2012-04-27 19:12       ` Ying Han
2012-04-27 19:12       ` Ying Han
     [not found]       ` <CALWz4ixHGCqfWh1U+JyiJWTkGmCDtXQy1vbHRjrHaU_pOgGuBw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-28  0:01         ` Hiroyuki Kamezawa
2012-04-28  0:01           ` Hiroyuki Kamezawa
2012-04-28  0:01           ` Hiroyuki Kamezawa
2012-04-30  9:07     ` Aneesh Kumar K.V
2012-04-30  9:07       ` Aneesh Kumar K.V
2012-04-30  9:07       ` Aneesh Kumar K.V
2012-04-27  6:02 ` [RFC][PATCH 7/9 v2] cgroup: avoid attaching task to a cgroup under rmdir() KAMEZAWA Hiroyuki
2012-04-27  6:02   ` KAMEZAWA Hiroyuki
2012-04-27 10:39   ` Frederic Weisbecker
2012-04-27 10:39     ` Frederic Weisbecker
     [not found]     ` <20120427103927.GA3514-oHC15RC7JGTpAmv0O++HtFaTQe2KTcn/@public.gmane.org>
2012-04-28  0:06       ` Hiroyuki Kamezawa
2012-04-28  0:06         ` Hiroyuki Kamezawa
2012-04-28  0:06         ` Hiroyuki Kamezawa
     [not found]   ` <4F9A366E.9020307-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-04-27 20:31     ` Tejun Heo
2012-04-27 20:31       ` Tejun Heo
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 20:33           ` Tejun Heo
2012-04-27 20:33           ` Tejun Heo
2012-04-27  6:06 ` [RFC][PATCH 9/9 v2] memcg: never return error at pre_destroy() KAMEZAWA Hiroyuki
2012-04-27  6:06   ` KAMEZAWA Hiroyuki
2012-04-27 21:28   ` Ying Han
2012-04-27 21:28     ` Ying Han
     [not found]     ` <CALWz4iyiM-CFgVaHiE1Lgd1ZwJzHwY3tx9XX6HeDPUV_wVPAtQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-04-28  0:25       ` Hiroyuki Kamezawa
2012-04-28  0:25         ` Hiroyuki Kamezawa
2012-04-28  0:25         ` Hiroyuki Kamezawa
2012-04-30 17:02         ` Ying Han
2012-04-30 17:02           ` Ying Han
2012-05-01 22:28   ` Suleiman Souhlal
2012-05-01 22:28     ` Suleiman Souhlal
     [not found]     ` <CABCjUKBhNkGf2QHzONMod3HmHgS-HxB5hUxpfJFHUG-eBkYBRw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-05-02  3:34       ` Hiroyuki Kamezawa
2012-05-02  3:34         ` Hiroyuki Kamezawa
2012-05-02  3:34         ` Hiroyuki Kamezawa

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