From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Kamezawa Hiroyuki
<kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Cc: "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>,
Han Ying <yinghan-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>,
"Aneesh Kumar K.V"
<aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Hiroyuki Kamezawa
<kamezawa.hiroyuki-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Linux Kernel
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH v3][0/6] memcg: prevent -ENOMEM in pre_destroy()
Date: Thu, 28 Jun 2012 09:06:25 -0700 [thread overview]
Message-ID: <CAOS58YNuSMjDB00UgOPjGCSFcRx-gjvMrW+e4uW0ug8WMsuFSw@mail.gmail.com> (raw)
In-Reply-To: <4FEC16EF.40408-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Hello, KAME.
On Thu, Jun 28, 2012 at 1:33 AM, Kamezawa Hiroyuki
<kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org> wrote:
>> Ooh, once memcg drops the __DEPRECATED_clear_css_refs, cgroup_rmdir()
>> will mark the cgroup dead before start calling pre_destroy() and none
>> of the above will happen.
>>
>
> Hm, threads which touches memcg should hold memcg's reference count rather
> than css.
> Right ? IIUC, one of reason is a reference from kswapd etc...hm. I'll check
> it.
Not sure I'm following. I meant that css_tryget() will always fail
once pre_destroy() calls being for the cgroup, so no new child or
reference can be created for it after that point.
Thanks.
--
tejun
prev parent reply other threads:[~2012-06-28 16:06 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-11 9:41 [PATCH v3][0/6] memcg: prevent -ENOMEM in pre_destroy() KAMEZAWA Hiroyuki
2012-05-11 9:45 ` [PATCH v3 1/6] memcg: fix error code in hugetlb_force_memcg_empty() KAMEZAWA Hiroyuki
[not found] ` <4FACDFAE.5050808-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-05-11 21:17 ` Andrew Morton
[not found] ` <20120511141754.e0719c26.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2012-05-14 1:07 ` KAMEZAWA Hiroyuki
2012-05-14 18:15 ` Tejun Heo
[not found] ` <20120514181556.GE2366-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-05-14 18:32 ` Tejun Heo
[not found] ` <20120514183219.GG2366-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-05-15 1:10 ` KAMEZAWA Hiroyuki
2012-05-15 15:12 ` Tejun Heo
2012-05-11 9:47 ` [PATCH 2/6] add res_counter_uncharge_until() KAMEZAWA Hiroyuki
[not found] ` <4FACE01A.4040405-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-05-11 21:19 ` Andrew Morton
[not found] ` <20120511141945.c487e94c.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2012-05-14 1:10 ` KAMEZAWA Hiroyuki
2012-05-14 10:08 ` Frederic Weisbecker
[not found] ` <CAFTL4hwGEhyxZO0sXx5gVyK_xjhMQEbHojJbHzQmVKafNyVWtw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-05-14 10:32 ` KAMEZAWA Hiroyuki
[not found] ` <4FB0DF4A.5010506-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-05-14 10:56 ` Frederic Weisbecker
2012-05-14 18:17 ` Tejun Heo
2012-05-11 9:48 ` [PATCH v3 3/6] memcg: use res_counter_uncharge_until in move_parent() KAMEZAWA Hiroyuki
[not found] ` <4FACDED0.3020400-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-05-11 9:49 ` [PATCH v3 4/6] memcg: move charges to root cgroup if use_hierarchy=0 KAMEZAWA Hiroyuki
[not found] ` <4FACE0A2.30608-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-05-14 20:14 ` Tejun Heo
[not found] ` <20120514201438.GI2366-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-05-15 0:04 ` KAMEZAWA Hiroyuki
2012-05-11 9:50 ` [PATCH v3 5/6] memcg: don't uncharge in mem_cgroup_move_account KAMEZAWA Hiroyuki
2012-05-11 9:53 ` [PATCH v3 6/6] remove __must_check for res_counter_charge_nofail() KAMEZAWA Hiroyuki
[not found] ` <4FACE184.6020307-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-05-14 20:09 ` Tejun Heo
[not found] ` <20120514200925.GH2366-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-05-15 0:02 ` KAMEZAWA Hiroyuki
2012-06-21 20:20 ` [PATCH v3][0/6] memcg: prevent -ENOMEM in pre_destroy() Tejun Heo
[not found] ` <20120621202043.GD4642-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-06-21 23:27 ` Kamezawa Hiroyuki
[not found] ` <4FE3ADDD.9060908-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-06-27 17:58 ` Tejun Heo
[not found] ` <20120627175818.GM15811-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2012-06-28 8:33 ` Kamezawa Hiroyuki
[not found] ` <4FEC16EF.40408-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2012-06-28 16:06 ` Tejun Heo [this message]
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