Re: [RFC] mm: memcg: add priority for soft limit reclaiming

Hillf Danton
2019-09-25T02:35:46Z

On Tue, 24 Sep 2019 17:23:35 +0000 from Roman Gushchin
>
> On Tue, Sep 24, 2019 at 03:30:16PM +0200, Michal Hocko wrote:
> >
> > But really, make sure you look into the existing feature set that memcg
> > v2 provides already and come back if you find it unsuitable and we can
> > move from there. Soft limit reclaim is dead and we should let it RIP.
>
> Can't agree more here.
>
> Cgroup v2 memory protection mechanisms (memory.low/min) should perfectly
> solve the described problem. If not, let's fix them rather than extend soft
> reclaim which is already dead.
>
Hehe, IIUC memory.low/min is essentially drawing a line that reclaimers
would try their best not to cross. Page preemption OTOH is near ten miles
away from that line though it is now on the shoulder of soft reclaiming.