Re: [PATCH v1 3/9] memcg: do not flush stats in irq context

[Johannes Weiner]

On Tue, Mar 28, 2023 at 06:16:32AM +0000, Yosry Ahmed 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>

Excellent, thanks!

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>