From mboxrd@z Thu Jan  1 00:00:00 1970
From: Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
Subject: Re: [PATCH] meminfo: show /proc/meminfo base on container's memcg
Date: Thu, 31 May 2012 12:29:01 +0400
Message-ID: <4FC72BCD.7040403@parallels.com>
References: <1338260214-21919-1-git-send-email-gaofeng@cn.fujitsu.com>
	<alpine.DEB.2.00.1205301433490.9716@chino.kir.corp.google.com>
	<4FC6B68C.2070703@jp.fujitsu.com>
	<CAHGf_=pFbsy4FO_UNu6O1-KyTd6O=pkmR8=3EGuZB5Reu3Vb9w@mail.gmail.com>
	<4FC6BC3E.5010807@jp.fujitsu.com>
	<alpine.DEB.2.00.1205301737530.25774@chino.kir.corp.google.com>
	<4FC6C111.2060108@jp.fujitsu.com>
	<alpine.DEB.2.00.1205301831270.25774@chino.kir.corp.google.com>
	<4FC6D881.4090706@jp.fujitsu.com>
	<alpine.DEB.2.00.1205302156090.25774@chino.kir.corp.google.com>
	<4FC70355.70805@jp.fujitsu.com>
	<alpine.DEB.2.00.1205302314190.25774@chino.kir.corp.google.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Content-Transfer-Encoding: 7bit
Return-path: <containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
In-Reply-To: <alpine.DEB.2.00.1205302314190.25774-X6Q0R45D7oAcqpCFd4KODRPsWskHk0ljAL8bYrjMMd8@public.gmane.org>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/containers>,
	<mailto:containers-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/containers/>
List-Post: <mailto:containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>
List-Help: <mailto:containers-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/containers>,
	<mailto:containers-request-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org?subject=subscribe>
Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
To: David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, mhocko-AlSwsSmVLrQ@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, KOSAKI Motohiro <kosaki.motohiro-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
List-Id: containers.vger.kernel.org

On 05/31/2012 10:17 AM, David Rientjes wrote:
>> >  Hmm....maybe need to mount cgroup in the container (again) and get an access
>> >  to cgroup
>> >  hierarchy and find the cgroup it belongs to......if it's allowed.
> An application should always know the cgroup that its attached to and be
> able to read its state using the command that I gave earlier.

I disagree. For simple applications, yes. For full containers, the 
cgroup in which it lives in is considered part of the external world.
It should not have any kind of access to it.

Also, tools need to work transparently.

That's the same case with /proc/stat, used for top. We can't expect 
people to recode top to work on containerized environments.