Re: [PATCH] mm/memcontrol: Add the drop_cache interface for cgroup v2

Michal Hocko
2020-09-22T10:01:52Z

On Tue 22-09-20 16:06:31, Yafang Shao wrote:
> On Tue, Sep 22, 2020 at 3:27 PM Michal Hocko <mhocko@suse.com> wrote:
[...]
> > What is the latency triggered by the memory reclaim? It should be mostly
> > a clean page cache right as drop_caches only drops clean pages. Or is
> > this more about [id]cache? Do you have any profiles where is the time
> > spent?
> >
>
> Yes, we have analyzed the issues in the direct reclaim, but that is
> not the point.

Are those fixed?

> The point is that each case may take us several days to analyze, while
> the user can't wait, so they will use drop_caches to workaround it
> until we find the solution.

As I've said there are several options to achieve an immediate action.
Careful resource domains configuration will certainly help with that.
--
Michal Hocko
SUSE Labs