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

From: Yosry Ahmed
Date: Tue May 24 2022 - 15:03:56 EST


On Tue, May 24, 2022 at 4:45 AM Johannes Weiner <hannes@xxxxxxxxxxx> 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?