Re: [PATCH v5 2/4] mm: memcontrol/slab: use helpers to access slab page's memcg_data

From: Shakeel Butt
Date: Mon Oct 05 2020 - 11:13:18 EST


On Fri, Oct 2, 2020 at 10:26 AM Roman Gushchin <guro@xxxxxx> wrote:
>
> To gather all direct accesses to struct page's memcg_data field
> in one place, let's introduce 3 new helpers to use in the slab
> accounting code:
> struct obj_cgroup **page_objcgs(struct page *page);
> struct obj_cgroup **page_objcgs_check(struct page *page);
> bool set_page_objcgs(struct page *page, struct obj_cgroup **objcgs);
>
> They are similar to the corresponding API for generic pages, except
> that the setter can return false, indicating that the value has been
> already set from a different thread.
>
> Signed-off-by: Roman Gushchin <guro@xxxxxx>
> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>