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>