Re: [RFC PATCH 0/3] Cgroup-based THP control

[Michal Hocko]

On Wed 30-10-24 14:45:24, Chris Down wrote:
> gutierrez.asier@xxxxxxxxxxxxxxxxxxx writes:
> > New memcg files are exposed: memory.thp_enabled and memory.thp_defrag, which
> > have completely the same format as global THP enabled/defrag.
> 
> cgroup controls exist because there are things we want to do for an entire
> class of processes (group OOM, resource control, etc). Enabling or disabling
> some specific setting is generally not one of them, hence why we got rid of
> things like per-cgroup vm.swappiness. We know that these controls do not
> compose well and have caused a lot of pain in the past. So my immediate
> reaction is a nack on the general concept, unless there's some absolutely
> compelling case here.
> 
> I talked a little at Kernel Recipes last year about moving away from sysctl
> and other global interfaces and making things more granular. Don't get me
> wrong, I think that is a good thing (although, of course, a very large
> undertaking) -- but it is a mistake to overload the amount of controls we
> expose as part of the cgroup interface.

Completely agreed!

-- 
Michal Hocko
SUSE Labs