Re: [PATCH] mm/memcg: support control THP behaviour in cgroup

[Shakeel Butt]

On Tue, May 10, 2022 at 7:19 PM CGEL <cgel.zte@xxxxxxxxx> wrote:
>
[...]
> > > >
> > > > All controls in cgroup v2 should be hierarchical. This is really
> > > > required for a proper delegation semantic.
> > > >
> > >
> > > Could we align to the semantic of /sys/fs/cgroup/memory.swappiness?
> > > Some distributions like Ubuntu is still using cgroup v1.
> >
> > Other than enable flag, how would you handle the defrag flag
> > hierarchically? It is much more complicated.
>
> Refer to memory.swappiness for cgroup, this new interface better be independent.

Let me give my 0.02. I buy the use-case of Admin restricting THPs to
low priority jobs but I don't think memory controller is the right
place to enforce that policy. Michal gave one way (prctl()) to enforce
that policy. Have you explored the BPF way to enforce this policy?