Re: [RFC PATCH v2 02/18] mm: memcontrol: bail out early when !mm in get_mem_cgroup_from_mm

[Shakeel Butt]

On Fri, Apr 9, 2021 at 5:32 AM Muchun Song <songmuchun@xxxxxxxxxxxxx> wrote:
>
> When mm is NULL, we do not need to hold rcu lock and call css_tryget for
> the root memcg. And we also do not need to check !mm in every loop of
> while. So bail out early when !mm.
>
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>