On Mon, Mar 27, 2023 at 11:16 PM Yosry Ahmed <yosryahmed@xxxxxxxxxx> wrote: > > Currently, the only context in which we can invoke an rstat flush from > irq context is through mem_cgroup_usage() on the root memcg when called > from memcg_check_events(). An rstat flush is an expensive operation that > should not be done in irq context, so do not flush stats and use the > stale stats in this case. > > Arguably, usage threshold events are not reliable on the root memcg > anyway since its usage is ill-defined. > > Suggested-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Suggested-by: Shakeel Butt <shakeelb@xxxxxxxxxx> > Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx> Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>