On Tue 28-03-23 22:16:44, Yosry Ahmed wrote: > In some situations, we may end up calling memcg_rstat_updated() with a > value of 0, which means the stat was not actually updated. An example is > if we fail to reclaim any pages in shrink_folio_list(). > > Do not add the cgroup to the rstat updated tree in this case, to avoid > unnecessarily flushing it. > > Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx> > Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> > --- > mm/memcontrol.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 361c0bbf7283..a63ee2efa780 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -618,6 +618,9 @@ static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val) > { > unsigned int x; > > + if (!val) > + return; > + > cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id()); > > x = __this_cpu_add_return(stats_updates, abs(val)); > -- > 2.40.0.348.gf938b09366-goog -- Michal Hocko SUSE Labs