diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 2e08b05bc6bf..26667bf16da5 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -466,34 +466,34 @@ static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio) } /* - * page_memcg_check - get the memory cgroup associated with a page - * @page: a pointer to the page struct + * folio_memcg_check - Get the memory cgroup associated with a folio. + * @folio: Pointer to the folio. * - * Returns a pointer to the memory cgroup associated with the page, - * or NULL. This function unlike page_memcg() can take any page - * as an argument. It has to be used in cases when it's not known if a page + * Returns a pointer to the memory cgroup associated with the folio, + * or NULL. This function unlike folio_memcg() can take any folio + * as an argument. It has to be used in cases when it's not known if a folio * has an associated memory cgroup pointer or an object cgroups vector or * an object cgroup. * - * For a non-kmem page any of the following ensures page and memcg binding + * For a non-kmem folio any of the following ensures folio and memcg binding * stability: * - * - the page lock + * - the folio lock * - LRU isolation - * - lock_page_memcg() + * - lock_folio_memcg() * - exclusive reference * - mem_cgroup_trylock_pages() * - * For a kmem page a caller should hold an rcu read lock to protect memcg - * associated with a kmem page from being released. + * For a kmem folio a caller should hold an rcu read lock to protect memcg + * associated with a kmem folio from being released. */ -static inline struct mem_cgroup *page_memcg_check(struct page *page) +static inline struct mem_cgroup *folio_memcg_check(struct folio *folio) { /* - * Because page->memcg_data might be changed asynchronously - * for slab pages, READ_ONCE() should be used here. + * Because folio->memcg_data might be changed asynchronously + * for slabs, READ_ONCE() should be used here. */ - unsigned long memcg_data = READ_ONCE(page->memcg_data); + unsigned long memcg_data = READ_ONCE(folio->memcg_data); if (memcg_data & MEMCG_DATA_OBJCGS) return NULL; @@ -508,6 +508,13 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page) return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); } +static inline struct mem_cgroup *page_memcg_check(struct page *page) +{ + if (PageTail(page)) + return NULL; + return folio_memcg_check((struct folio *)page); +} + static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg) { struct mem_cgroup *memcg; @@ -1170,6 +1177,11 @@ static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio) return NULL; } +static inline struct mem_cgroup *folio_memcg_check(struct folio *folio) +{ + return NULL; +} + static inline struct mem_cgroup *page_memcg_check(struct page *page) { return NULL; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2758b67eb169..17965e558ab7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2952,13 +2952,13 @@ struct mem_cgroup *mem_cgroup_from_obj_folio(struct folio *folio, void *p) } /* - * page_memcg_check() is used here, because in theory we can encounter + * folio_memcg_check() is used here, because in theory we can encounter * a folio where the slab flag has been cleared already, but * slab->memcg_data has not been freed yet - * page_memcg_check(page) will guarantee that a proper memory + * folio_memcg_check() will guarantee that a proper memory * cgroup pointer or NULL will be returned. */ - return page_memcg_check(folio_page(folio, 0)); + return folio_memcg_check(folio); } /*