Re: [PATCHv2] memcg: reclaim memory from node in round-robin

[KOSAKI Motohiro]

> I changed the logic a little and add a filter for skipping nodes.
> With large NUMA, tasks may under cpuset or mempolicy and the usage of memory
> can be unbalanced. So, I think a filter is required.
> 
> ==
> Now, memory cgroup's direct reclaim frees memory from the current node.
> But this has some troubles. In usual, when a set of threads works in
> cooperative way, they are tend to on the same node. So, if they hit
> limits under memcg, it will reclaim memory from themselves, it may be
> active working set.
> 
> For example, assume 2 node system which has Node 0 and Node 1
> and a memcg which has 1G limit. After some work, file cacne remains and
> and usages are
>    Node 0:  1M
>    Node 1:  998M.
> 
> and run an application on Node 0, it will eats its foot before freeing
> unnecessary file caches.
> 
> This patch adds round-robin for NUMA and adds equal pressure to each
> node. When using cpuset's spread memory feature, this will work very well.

Looks nice. And it would be more nice if global reclaim has the same feature.
Do you have a plan to do it?


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