Re: [PATCH v3] mm: memcg: Use larger batches for proactive reclaim

From: Michal Hocko
Date: Mon Feb 05 2024 - 17:05:21 EST


On Mon 05-02-24 12:47:47, T.J. Mercier wrote:
> On Mon, Feb 5, 2024 at 12:36 PM Michal Hocko <mhocko@xxxxxxxx> wrote:
[...]
> > This of something like
> > timeout $TIMEOUT echo $TARGET > $MEMCG_PATH/memory.reclaim
> > where timeout acts as a stop gap if the reclaim cannot finish in
> > TIMEOUT.
>
> Yeah I get the desired behavior, but using sc->nr_reclaimed to achieve
> it is what's bothering me.

I am not really happy about this subtlety. If we have a better way then
let's do it. Better in its own patch, though.

> It's already wired up that way though, so if you want to make this
> change now then I can try to test for the difference using really
> large reclaim targets.

Yes, please. If you want it a separate patch then no objection from me
of course. If you do no like the nr_to_reclaim bailout then maybe we can
go with a simple break out flag in scan_control.

Thanks!
--
Michal Hocko
SUSE Labs