Re: [PATCH 3/3] mm/memcg: add next_mz back if not reclaimed yet

Michal Hocko
2022-03-09T13:48:50Z

[Cc Tim - the patch is http://lkml.kernel.org/r/20220308012047.26638-3-richard.weiyang@gmail.com]

On Wed 09-03-22 00:46:20, Wei Yang wrote:
> On Tue, Mar 08, 2022 at 09:17:58AM +0100, Michal Hocko wrote:
> >On Tue 08-03-22 01:20:47, Wei Yang wrote:
> >> next_mz is removed from rb_tree, let's add it back if no reclaim has
> >> been tried.
> >
> >Could you elaborate more why we need/want this?
> >
>
> Per my understanding, we add back the right most node even reclaim makes no
> progress, so it is reasonable to add back a node if we didn't get a chance to
> do reclaim on it.

Your patch sounded familiar and I can remember now. The same fix has
been posted by Tim last year
https://lore.kernel.org/linux-mm/8d35206601ccf0e1fe021d24405b2a0c2f4e052f.1613584277.git.tim.c.chen@linux.intel.com/
It was posted with other changes to the soft limit code which I didn't
like but I have acked this particular one. Not sure what has happened
with it afterwards.
--
Michal Hocko
SUSE Labs