Re: [RFC] mm: bail out in shrin_inactive_list

From: Mel Gorman
Date: Tue Jul 26 2016 - 03:47:01 EST


On Tue, Jul 26, 2016 at 10:21:57AM +0900, Minchan Kim wrote:
> > > I believe proper fix is to modify get_scan_count. IOW, I think
> > > we should introduce lruvec_reclaimable_lru_size with proper
> > > classzone_idx but I don't know how we can fix it with memcg
> > > which doesn't have zone stat now. should introduce zone stat
> > > back to memcg? Or, it's okay to ignore memcg?
> > >
> >
> > I think it's ok to ignore memcg in this case as a memcg shrink is often
> > going to be for pages that can use highmem anyway.
>
> So, you mean it's okay to ignore kmemcg case?
> If memcg guys agree it, I want to make get_scan_count consider
> reclaimable lru size under the reclaim constraint, instead.
>

For now, I believe yet. My understanding is that the primary use cases
for kmemcg is systems running large numbers of containers. It consider
it extremely unlikely that large 32-bit systems are being used for large
numbers of containers and require usage of kmemcg.

--
Mel Gorman
SUSE Labs