Re: [PATCH 2/2] mm: Consider subtrees in memory.events

Johannes Weiner
2019-01-30T19:27:17Z

On Wed, Jan 30, 2019 at 11:11:44AM -0800, Shakeel Butt wrote:
> Hi Tejun,
>
> On Wed, Jan 30, 2019 at 9:07 AM Tejun Heo <tj@kernel.org> wrote:
> >
> > Hello, Michal.
> >
> > On Wed, Jan 30, 2019 at 05:50:58PM +0100, Michal Hocko wrote:
> > > > Yeah, cgroup.events and .stat files as some of the local stats would
> > > > be useful too, so if we don't flip memory.events we'll end up with sth
> > > > like cgroup.events.local, memory.events.tree and memory.stats.local,
> > > > which is gonna be hilarious.
> > >
> > > Why cannot we simply have memory.events_tree and be done with it? Sure
> > > the file names are not goin to be consistent which is a minus but that
> > > ship has already sailed some time ago.
> >
> > Because the overall cost of shitty interface will be way higher in the
> > longer term. cgroup2 interface is far from perfect but is way better
> > than cgroup1 especially for the memory controller. Why do you think
> > that is?
> >
>
> I thought you are fine with the separate interface for the hierarchical events.

Every other file in cgroup2 is hierarchical, but for recursive
memory.events you'd need to read memory.events_tree?

Do we hate our users that much? :(