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

[Kamezawa Hiroyuki]

(2012/05/31 9:22), KOSAKI Motohiro wrote:
> On Wed, May 30, 2012 at 8:08 PM, Kamezawa Hiroyuki
> <kamezawa.hiroyu at jp.fujitsu.com>  wrote:
>> (2012/05/31 6:38), David Rientjes wrote:
>>>
>>> On Tue, 29 May 2012, Gao feng wrote:
>>>
>>>> cgroup and namespaces are used for creating containers but some of
>>>> information is not isolated/virtualized. This patch is for isolating
>>>> /proc/meminfo
>>>> information per container, which uses memory cgroup. By this, top,free
>>>> and other tools under container can work as expected(show container's
>>>> usage) without changes.
>>>>
>>>> This patch is a trial to show memcg's info in /proc/meminfo if 'current'
>>>> is under a memcg other than root.
>>>>
>>>> we show /proc/meminfo base on container's memory cgroup.
>>>> because there are lots of info can't be provide by memcg, and
>>>> the cmds such as top, free just use some entries of /proc/meminfo,
>>>> we replace those entries by memory cgroup.
>>>>
>>>> if container has no memcg, we will show host's /proc/meminfo
>>>> as before.
>>>>
>>>> there is no idea how to deal with Buffers,I just set it zero,
>>>> It's strange if Buffers bigger than MemTotal.
>>>>
>>>> Signed-off-by: Gao feng<gaofeng at cn.fujitsu.com>
>>>
>>>
>>> Nack, this type of thing was initially tried with cpusets when a thread
>>> was bound to a subset of nodes, i.e. only show the total amount of memory
>>> spanned by those nodes.
>>>
>>
>> Hmm. How about having memory.meminfo under memory cgroup directory and
>> use it with bind mount ? (container tools will be able to help it.)
>> Then, container applications(top,free,etc..) can read the values they wants.
>> If admins don't want it, they'll not use bind mount.
>
> +1. 50% users need namespace separation and others don't. We need a
> selectability.

My test with sysfs node's meminfo seems to work...

[root at rx100-1 qqm]# mount --bind /sys/devices/system/node/node0/meminfo /proc/meminfo
[root at rx100-1 qqm]# cat /proc/meminfo

Node 0 MemTotal:        8379636 kB
Node 0 MemFree:         4050224 kB
Node 0 MemUsed:         4329412 kB
Node 0 Active:          3010876 kB
Node 0 Inactive:         507480 kB
Node 0 Active(anon):    2671920 kB
Node 0 Inactive(anon):   111596 kB
Node 0 Active(file):     338956 kB
Node 0 Inactive(file):   395884 kB
Node 0 Unevictable:       48316 kB
Node 0 Mlocked:           11524 kB
Node 0 Dirty:                 8 kB
Node 0 Writeback:             0 kB
Node 0 FilePages:        744908 kB
Node 0 Mapped:            20604 kB
Node 0 AnonPages:       1344940 kB
Node 0 Shmem:              1448 kB
Node 0 KernelStack:        3528 kB
Node 0 PageTables:        53840 kB
Node 0 NFS_Unstable:          0 kB
Node 0 Bounce:                0 kB
Node 0 WritebackTmp:          0 kB
Node 0 Slab:             184404 kB
Node 0 SReclaimable:     131060 kB
Node 0 SUnreclaim:        53344 kB
Node 0 HugePages_Total:     0
Node 0 HugePages_Free:      0
Node 0 HugePages_Surp:      0

Thanks,
-Kame