linux-master/mm/slab.h

16  * Internal slab definitions
52 struct slab {
62 					struct slab *next;
96 	static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
104 static_assert(sizeof(struct slab) <= sizeof(struct page));
106 static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t)));
110  * folio_slab - Converts from folio to slab.
113  * Currently struct slab is a different representation of a folio where
116  * Return: The slab which contains this folio.
119 	const struct folio *:	(const struct slab *)(folio),		\
120 	struct folio *:		(struct slab *)(folio)))
123  * slab_folio - The folio allocated for a slab
124  * @slab: The slab.
128  * now accessed by struct slab. It is occasionally necessary to convert back to
134 	const struct slab *:	(const struct folio *)s,		\
135 	struct slab *:		(struct folio *)s))
138  * page_slab - Converts from first struct page to slab.
139  * @p: The first (either head of compound or single) page of slab.
141  * A temporary wrapper to convert struct page to struct slab in situations where
144  * Long-term ideally everything would work with struct slab directly or go
145  * through folio to struct slab.
147  * Return: The slab which contains this page
150 	const struct page *:	(const struct slab *)(p),		\
151 	struct page *:		(struct slab *)(p)))
154  * slab_page - The first struct page allocated for a slab
155  * @slab: The slab.
157  * A convenience wrapper for converting slab to the first struct page of the
159  * struct slab.
167 static inline bool slab_test_pfmemalloc(const struct slab *slab)
169 	return folio_test_active((struct folio *)slab_folio(slab));
172 static inline void slab_set_pfmemalloc(struct slab *slab)
174 	folio_set_active(slab_folio(slab));
177 static inline void slab_clear_pfmemalloc(struct slab *slab)
179 	folio_clear_active(slab_folio(slab));
182 static inline void __slab_clear_pfmemalloc(struct slab *slab)
184 	__folio_clear_active(slab_folio(slab));
187 static inline void *slab_address(const struct slab *slab)
189 	return folio_address(slab_folio(slab));
192 static inline int slab_nid(const struct slab *slab)
194 	return folio_nid(slab_folio(slab));
197 static inline pg_data_t *slab_pgdat(const struct slab *slab)
199 	return folio_pgdat(slab_folio(slab));
202 static inline struct slab *virt_to_slab(const void *addr)
212 static inline int slab_order(const struct slab *slab)
214 	return folio_order((struct folio *)slab_folio(slab));
217 static inline size_t slab_size(const struct slab *slab)
219 	return PAGE_SIZE << slab_order(slab);
241  * contains both the order and the number of objects that a slab of the
273 	int refcount;			/* Refcount for slab cache destroy */
279 	struct list_head list;		/* List of slab caches */
322 				const struct slab *slab, void *x)
324 	void *object = x - (x - slab_address(slab)) % cache->size;
325 	void *last_object = slab_address(slab) +
326 		(slab->objects - 1) * cache->size;
342 					const struct slab *slab, void *obj)
346 	return __obj_to_index(cache, slab_address(slab), obj);
350 				const struct slab *slab)
352 	return slab->objects;
356  * State of the slab allocator.
360  * have the problem that the structures used for managing slab caches are
361  * allocated from slab caches themselves.
364 	DOWN,			/* No slab functionality yet */
372 /* The slab cache mutex protects the management structures during changes */
375 /* The list of all slab caches on the system */
378 /* The slab cache that manages slab cache information */
420 /* Functions provided by the slab allocators */
541  * slab_objcgs - get the object cgroups vector associated with a slab
542  * @slab: a pointer to the slab struct
544  * Returns a pointer to the object cgroups vector associated with the slab,
547 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
549 	unsigned long memcg_data = READ_ONCE(slab->memcg_data);
552 							slab_page(slab));
553 	VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
558 int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
563 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
568 static inline int memcg_alloc_slab_cgroups(struct slab *slab,
658 	struct slab *kp_slab;
666 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
670 			 const struct slab *slab, bool to_user);