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 12:59:33 +0400
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To: Kamezawa Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Cc: David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, 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 12:51 PM, Kamezawa Hiroyuki wrote:
>> One think to keep in mind: A file in memcg does not need to follow the
>> same format
>> of /proc/meminfo so we can bind mount. We should be able to
>> reconstruct that in
>>  userspace based on information available from the kernel. You can
>> even collect that
>> from multiple locations, and *then* you bind mount.
>
> I'm sorry I couldn't fully understand. Could you explain more ?
> Do you mean
>   - bind mount memory cgroup directory into the container for exporting
> information
>   - Some user-space apps, FUSE-procfs or some, can provide enough
> information
>

Implementation details aside, the idea is to have something like FUSE to 
hook the read(), and then construct the information it needs to present 
in the proper format.

Alternatively, for files that doesn't change a lot, you can create a 
file /container-storage-area/my_copy_of_meminfo at container creation, 
and bind mount *that* file.

There is no reason to bind mount a kernel-provided file directly.