Re: [PATCH] memcg: provide reclaim stats via 'memory.reclaim'

Michal Hocko
2022-05-25T08:59:18Z

On Tue 24-05-22 12:01:01, Yosry Ahmed wrote:
> On Tue, May 24, 2022 at 4:45 AM Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> wrote:
> >
> > On Mon, May 23, 2022 at 03:50:34PM -0700, Yosry Ahmed wrote:
> > > I think it might be useful to have a dedicated entry in memory.stat
> > > for proactively reclaimed memory. A case where this would be useful is
> > > tuning and evaluating userspace proactive reclaimers. For instance, if
> > > a userspace agent is asking the kernel to reclaim 100M, but it could
> > > only reclaim 10M, then most probably the proactive reclaimer is not
> > > using a good methodology to figure out how much memory do we need to
> > > reclaim.
> > >
> > > IMO this is more useful, and a superset of just reading the last
> > > reclaim request status through memory.reclaim (read stat before and
> > > after).
> >
> > +1
>
> It might also be useful to have a breakdown of this by memory type:
> file, anon, or shrinkers.
>
> It would also fit in nicely with a potential type=file/anon/shrinker
> argument to memory.reclaim. Thoughts on this?

Can we start simple and see what real usecases actually will need?
--
Michal Hocko
SUSE Labs