Re: [PATCH v5 03/11] mm: memcontrol: prepare objcg API for non-kmem usage

[Michal Koutný]

Hello.

On Mon, May 30, 2022 at 03:49:11PM +0800, Muchun Song <songmuchun@xxxxxxxxxxxxx> wrote:
> So we also allocate an object cgroup for the root_mem_cgroup.

This change made me wary that this patch also kmem charging in the
root_mem_cgroup. Fortunately, get_obj_cgroup_from_current won't return
this objcg so all is fine.

> +}
> +#else
> +static inline void obj_cgroup_release_bytes(struct obj_cgroup *objcg)
> +{
> +}
> +#endif

This empty body is for !CONFIG_MEMCG_KMEM, however, the subsequent use for LRU
pages makes no use of these, so it's warranted.

Altogether, I find this correct, hence
Reviewed-by: Michal Koutný <mkoutny@xxxxxxxx>