Re: [PATCH] meminfo: show /proc/meminfo base on container's memcg

From: Gao feng
Date: Thu May 31 2012 - 03:58:08 EST


ä 2012å05æ31æ 15:42, KOSAKI Motohiro åé:
> (5/31/12 3:35 AM), David Rientjes wrote:
>> On Thu, 31 May 2012, KOSAKI Motohiro wrote:
>>
>>>> As I said, LXC and namespace isolation is a tangent to the discussion of
>>>> faking the /proc/meminfo for the memcg context of a thread.
>>>
>>> Because of, /proc/meminfo affect a lot of libraries behavior. So, it's not only
>>> application issue. If you can't rewrite _all_ of userland assets, fake meminfo
>>> can't be escaped. Again see alternative container implementation.
>>>
>>
>> It's a tangent because it isn't a complete psuedo /proc/meminfo for all
>> threads attached to a memcg regardless of any namespace isolation; the LXC
>> solution has existed for a couple of years by its procfs patchset that
>> overlaps procfs with fuse and can suppress or modify any output in the
>> context of a memory controller using things like
>> memory.{limit,usage}_in_bytes. I'm sure all other fields could be
>> modified if outputted in some structured way via memcg; it looks like
>> memory.stat would need to be extended to provide that. If that's mounted
>> prior to executing the application, then your isolation is achieved and
>> all libraries should see the new output that you've defined in LXC.
>>
>> However, this seems like a seperate topic than the patch at hand which
>> does this directly to /proc/meminfo based on a thread's memcg context,
>> that's the part that I'm nacking.
>
> Then, I NAKed current patch too. Yeah, current one is ugly. It assume _all_
> user need namespace isolation and it clearly is not.
>
>
>> I'd recommend to Gao to expose this
>> information via memory.stat and then use fuse and the procfs lxc support
>> as your way of contextualizing the resources.
>
> It's one of a option. But, I seriously doubt fuse can make simpler than kamezawa-san's
> idea. But yeah, I might NACK kamezawa-san's one if he will post ugly patch.
>

It seams I should do some homework to make the implement beautifully.

I think kamezawa-san's idea is more simpler.
thanks for your advice.

>
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