On Wed, Aug 30, 2017 at 02:36:55PM +0200, Michal Hocko wrote: > On Tue 29-08-17 11:01:50, Roman Gushchin wrote: > [...] > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index b9cf3cf4a3d0..a69d23082abf 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -1792,6 +1792,9 @@ static void refill_stock(struct mem_cgroup *memcg, > > unsigned int nr_pages) > > } > > stock->nr_pages += nr_pages; > > > > + if (stock->nr_pages > CHARGE_BATCH) > > + drain_stock(stock); > > + > > local_irq_restore(flags); > > } > > Why do we need this? In other words, why cannot we rely on draining we > already do?
The existing draining depends on memory pressure, so to keep the accounting (which we expose to a user) reasonable accurate even without memory pressure, we need to limit the size of per-cpu stocks. Thanks!
