Re: [PATCH v1 3/3] mm: per-process reclaim

[Johannes Weiner]

On Wed, Jun 15, 2016 at 09:40:27AM +0900, Minchan Kim wrote:
> A question is it seems cgroup2 doesn't have per-cgroup swappiness.
> Why?
> 
> I think we need it in one-cgroup-per-app model.

Can you explain why you think that?

As we have talked about this recently in the LRU balancing thread,
swappiness is the cost factor between file IO and swapping, so the
only situation I can imagine you'd need a memcg swappiness setting is
when you have different cgroups use different storage devices that do
not have comparable speeds.

So I'm not sure I understand the relationship to an app-group model.