Re: About cgroup memory limits

[KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>]

(2012/05/10 19:55), Andre Nathan wrote:

> Thanks a lot Kame.
> 
> On Thu, 2012-05-10 at 18:47 +0900, KAMEZAWA Hiroyuki wrote:
>> From above, rss + mapped_file == resident.
> 
> But if you check the numbers I get from memory.stat and the sum of the
> statm fields for all container processes, this doesn't hold.
> 
> resident    = 28741632
> rss         = 8192000
> mapped_file = 3743744
> 
> Am I missing something here?
> 

Considering again...

file_mapped is accounted into the memcg where it's accounted as 'cache' to.

So, you can know 'mapped_file/caches ratio' but you can't know which cgroup
maps it.

>        size  resident     share     text  lib       data  dt
>   897208320  28741632  20500480  1171456    0  170676224   0
> 
 
resident - share = anon.

28741632  - 20500480 = 8241152 (anon)  near value to rss.

About file_mapped, 3743744(mapped_file)  * 100 /20500480(shared) = 18 %

18% of your app's file-mapping may be accounted into the memcg.

You may be able to different score if you do all test after drop-cache.
echo 3 > /proc/sys/vm/drop_caches

Thanks,
-Kame