Re: [RFC PROPOSAL] memcg: per-memcg user space reclaim interface

From: Michal Hocko
Date: Fri Jul 03 2020 - 02:35:53 EST


On Thu 02-07-20 08:22:22, Shakeel Butt wrote:
[...]
> Interface options:
> ------------------
>
> 1) memcg interface e.g. 'echo 10M > memory.reclaim'
>
> + simple
> + can be extended to target specific type of memory (anon, file, kmem).
> - most probably restricted to cgroup v2.
>
> 2) fadvise(PAGEOUT) on cgroup_dir_fd
>
> + more general and applicable to other FSes (actually we are using
> something similar for tmpfs).
> + can be extended in future to just age the LRUs instead of reclaim or
> some new use cases.

Could you explain why memory.high as an interface to trigger pro-active
memory reclaim is not sufficient. Also memory.low limit to protect
latency sensitve workloads?
--
Michal Hocko
SUSE Labs