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[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / mm / slab.c
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1 /*
2 * linux/mm/slab.c
3 * Written by Mark Hemment, 1996/97.
4 * (markhe@nextd.demon.co.uk)
6 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
8 * Major cleanup, different bufctl logic, per-cpu arrays
9 * (c) 2000 Manfred Spraul
11 * Cleanup, make the head arrays unconditional, preparation for NUMA
12 * (c) 2002 Manfred Spraul
14 * An implementation of the Slab Allocator as described in outline in;
15 * UNIX Internals: The New Frontiers by Uresh Vahalia
16 * Pub: Prentice Hall ISBN 0-13-101908-2
17 * or with a little more detail in;
18 * The Slab Allocator: An Object-Caching Kernel Memory Allocator
19 * Jeff Bonwick (Sun Microsystems).
20 * Presented at: USENIX Summer 1994 Technical Conference
22 * The memory is organized in caches, one cache for each object type.
23 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
24 * Each cache consists out of many slabs (they are small (usually one
25 * page long) and always contiguous), and each slab contains multiple
26 * initialized objects.
28 * This means, that your constructor is used only for newly allocated
29 * slabs and you must pass objects with the same initializations to
30 * kmem_cache_free.
32 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
33 * normal). If you need a special memory type, then must create a new
34 * cache for that memory type.
36 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
37 * full slabs with 0 free objects
38 * partial slabs
39 * empty slabs with no allocated objects
41 * If partial slabs exist, then new allocations come from these slabs,
42 * otherwise from empty slabs or new slabs are allocated.
44 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
45 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
47 * Each cache has a short per-cpu head array, most allocs
48 * and frees go into that array, and if that array overflows, then 1/2
49 * of the entries in the array are given back into the global cache.
50 * The head array is strictly LIFO and should improve the cache hit rates.
51 * On SMP, it additionally reduces the spinlock operations.
53 * The c_cpuarray may not be read with enabled local interrupts -
54 * it's changed with a smp_call_function().
56 * SMP synchronization:
57 * constructors and destructors are called without any locking.
58 * Several members in struct kmem_cache and struct slab never change, they
59 * are accessed without any locking.
60 * The per-cpu arrays are never accessed from the wrong cpu, no locking,
61 * and local interrupts are disabled so slab code is preempt-safe.
62 * The non-constant members are protected with a per-cache irq spinlock.
64 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
65 * in 2000 - many ideas in the current implementation are derived from
66 * his patch.
68 * Further notes from the original documentation:
70 * 11 April '97. Started multi-threading - markhe
71 * The global cache-chain is protected by the mutex 'cache_chain_mutex'.
72 * The sem is only needed when accessing/extending the cache-chain, which
73 * can never happen inside an interrupt (kmem_cache_create(),
74 * kmem_cache_shrink() and kmem_cache_reap()).
76 * At present, each engine can be growing a cache. This should be blocked.
78 * 15 March 2005. NUMA slab allocator.
79 * Shai Fultheim <shai@scalex86.org>.
80 * Shobhit Dayal <shobhit@calsoftinc.com>
81 * Alok N Kataria <alokk@calsoftinc.com>
82 * Christoph Lameter <christoph@lameter.com>
84 * Modified the slab allocator to be node aware on NUMA systems.
85 * Each node has its own list of partial, free and full slabs.
86 * All object allocations for a node occur from node specific slab lists.
89 #include <linux/slab.h>
90 #include <linux/mm.h>
91 #include <linux/poison.h>
92 #include <linux/swap.h>
93 #include <linux/cache.h>
94 #include <linux/interrupt.h>
95 #include <linux/init.h>
96 #include <linux/compiler.h>
97 #include <linux/cpuset.h>
98 #include <linux/proc_fs.h>
99 #include <linux/seq_file.h>
100 #include <linux/notifier.h>
101 #include <linux/kallsyms.h>
102 #include <linux/cpu.h>
103 #include <linux/sysctl.h>
104 #include <linux/module.h>
105 #include <linux/kmemtrace.h>
106 #include <linux/rcupdate.h>
107 #include <linux/string.h>
108 #include <linux/uaccess.h>
109 #include <linux/nodemask.h>
110 #include <linux/kmemleak.h>
111 #include <linux/mempolicy.h>
112 #include <linux/mutex.h>
113 #include <linux/fault-inject.h>
114 #include <linux/rtmutex.h>
115 #include <linux/reciprocal_div.h>
116 #include <linux/debugobjects.h>
117 #include <linux/kmemcheck.h>
119 #include <asm/cacheflush.h>
120 #include <asm/tlbflush.h>
121 #include <asm/page.h>
124 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
125 * 0 for faster, smaller code (especially in the critical paths).
127 * STATS - 1 to collect stats for /proc/slabinfo.
128 * 0 for faster, smaller code (especially in the critical paths).
130 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
133 #ifdef CONFIG_DEBUG_SLAB
134 #define DEBUG 1
135 #define STATS 1
136 #define FORCED_DEBUG 1
137 #else
138 #define DEBUG 0
139 #define STATS 0
140 #define FORCED_DEBUG 0
141 #endif
143 /* Shouldn't this be in a header file somewhere? */
144 #define BYTES_PER_WORD sizeof(void *)
145 #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
147 #ifndef ARCH_KMALLOC_MINALIGN
149 * Enforce a minimum alignment for the kmalloc caches.
150 * Usually, the kmalloc caches are cache_line_size() aligned, except when
151 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
152 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
153 * alignment larger than the alignment of a 64-bit integer.
154 * ARCH_KMALLOC_MINALIGN allows that.
155 * Note that increasing this value may disable some debug features.
157 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
158 #endif
160 #ifndef ARCH_SLAB_MINALIGN
162 * Enforce a minimum alignment for all caches.
163 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
164 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
165 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
166 * some debug features.
168 #define ARCH_SLAB_MINALIGN 0
169 #endif
171 #ifndef ARCH_KMALLOC_FLAGS
172 #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
173 #endif
175 /* Legal flag mask for kmem_cache_create(). */
176 #if DEBUG
177 # define CREATE_MASK (SLAB_RED_ZONE | \
178 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
179 SLAB_CACHE_DMA | \
180 SLAB_STORE_USER | \
181 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
182 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
183 SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK)
184 #else
185 # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
186 SLAB_CACHE_DMA | \
187 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
188 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
189 SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK)
190 #endif
193 * kmem_bufctl_t:
195 * Bufctl's are used for linking objs within a slab
196 * linked offsets.
198 * This implementation relies on "struct page" for locating the cache &
199 * slab an object belongs to.
200 * This allows the bufctl structure to be small (one int), but limits
201 * the number of objects a slab (not a cache) can contain when off-slab
202 * bufctls are used. The limit is the size of the largest general cache
203 * that does not use off-slab slabs.
204 * For 32bit archs with 4 kB pages, is this 56.
205 * This is not serious, as it is only for large objects, when it is unwise
206 * to have too many per slab.
207 * Note: This limit can be raised by introducing a general cache whose size
208 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
211 typedef unsigned int kmem_bufctl_t;
212 #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
213 #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
214 #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
215 #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
218 * struct slab
220 * Manages the objs in a slab. Placed either at the beginning of mem allocated
221 * for a slab, or allocated from an general cache.
222 * Slabs are chained into three list: fully used, partial, fully free slabs.
224 struct slab {
225 struct list_head list;
226 unsigned long colouroff;
227 void *s_mem; /* including colour offset */
228 unsigned int inuse; /* num of objs active in slab */
229 kmem_bufctl_t free;
230 unsigned short nodeid;
234 * struct slab_rcu
236 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
237 * arrange for kmem_freepages to be called via RCU. This is useful if
238 * we need to approach a kernel structure obliquely, from its address
239 * obtained without the usual locking. We can lock the structure to
240 * stabilize it and check it's still at the given address, only if we
241 * can be sure that the memory has not been meanwhile reused for some
242 * other kind of object (which our subsystem's lock might corrupt).
244 * rcu_read_lock before reading the address, then rcu_read_unlock after
245 * taking the spinlock within the structure expected at that address.
247 * We assume struct slab_rcu can overlay struct slab when destroying.
249 struct slab_rcu {
250 struct rcu_head head;
251 struct kmem_cache *cachep;
252 void *addr;
256 * struct array_cache
258 * Purpose:
259 * - LIFO ordering, to hand out cache-warm objects from _alloc
260 * - reduce the number of linked list operations
261 * - reduce spinlock operations
263 * The limit is stored in the per-cpu structure to reduce the data cache
264 * footprint.
267 struct array_cache {
268 unsigned int avail;
269 unsigned int limit;
270 unsigned int batchcount;
271 unsigned int touched;
272 spinlock_t lock;
273 void *entry[]; /*
274 * Must have this definition in here for the proper
275 * alignment of array_cache. Also simplifies accessing
276 * the entries.
281 * bootstrap: The caches do not work without cpuarrays anymore, but the
282 * cpuarrays are allocated from the generic caches...
284 #define BOOT_CPUCACHE_ENTRIES 1
285 struct arraycache_init {
286 struct array_cache cache;
287 void *entries[BOOT_CPUCACHE_ENTRIES];
291 * The slab lists for all objects.
293 struct kmem_list3 {
294 struct list_head slabs_partial; /* partial list first, better asm code */
295 struct list_head slabs_full;
296 struct list_head slabs_free;
297 unsigned long free_objects;
298 unsigned int free_limit;
299 unsigned int colour_next; /* Per-node cache coloring */
300 spinlock_t list_lock;
301 struct array_cache *shared; /* shared per node */
302 struct array_cache **alien; /* on other nodes */
303 unsigned long next_reap; /* updated without locking */
304 int free_touched; /* updated without locking */
308 * Need this for bootstrapping a per node allocator.
310 #define NUM_INIT_LISTS (3 * MAX_NUMNODES)
311 struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
312 #define CACHE_CACHE 0
313 #define SIZE_AC MAX_NUMNODES
314 #define SIZE_L3 (2 * MAX_NUMNODES)
316 static int drain_freelist(struct kmem_cache *cache,
317 struct kmem_list3 *l3, int tofree);
318 static void free_block(struct kmem_cache *cachep, void **objpp, int len,
319 int node);
320 static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
321 static void cache_reap(struct work_struct *unused);
324 * This function must be completely optimized away if a constant is passed to
325 * it. Mostly the same as what is in linux/slab.h except it returns an index.
327 static __always_inline int index_of(const size_t size)
329 extern void __bad_size(void);
331 if (__builtin_constant_p(size)) {
332 int i = 0;
334 #define CACHE(x) \
335 if (size <=x) \
336 return i; \
337 else \
338 i++;
339 #include <linux/kmalloc_sizes.h>
340 #undef CACHE
341 __bad_size();
342 } else
343 __bad_size();
344 return 0;
347 static int slab_early_init = 1;
349 #define INDEX_AC index_of(sizeof(struct arraycache_init))
350 #define INDEX_L3 index_of(sizeof(struct kmem_list3))
352 static void kmem_list3_init(struct kmem_list3 *parent)
354 INIT_LIST_HEAD(&parent->slabs_full);
355 INIT_LIST_HEAD(&parent->slabs_partial);
356 INIT_LIST_HEAD(&parent->slabs_free);
357 parent->shared = NULL;
358 parent->alien = NULL;
359 parent->colour_next = 0;
360 spin_lock_init(&parent->list_lock);
361 parent->free_objects = 0;
362 parent->free_touched = 0;
365 #define MAKE_LIST(cachep, listp, slab, nodeid) \
366 do { \
367 INIT_LIST_HEAD(listp); \
368 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
369 } while (0)
371 #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
372 do { \
373 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
374 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
375 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
376 } while (0)
378 #define CFLGS_OFF_SLAB (0x80000000UL)
379 #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
381 #define BATCHREFILL_LIMIT 16
383 * Optimization question: fewer reaps means less probability for unnessary
384 * cpucache drain/refill cycles.
386 * OTOH the cpuarrays can contain lots of objects,
387 * which could lock up otherwise freeable slabs.
389 #define REAPTIMEOUT_CPUC (2*HZ)
390 #define REAPTIMEOUT_LIST3 (4*HZ)
392 #if STATS
393 #define STATS_INC_ACTIVE(x) ((x)->num_active++)
394 #define STATS_DEC_ACTIVE(x) ((x)->num_active--)
395 #define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
396 #define STATS_INC_GROWN(x) ((x)->grown++)
397 #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
398 #define STATS_SET_HIGH(x) \
399 do { \
400 if ((x)->num_active > (x)->high_mark) \
401 (x)->high_mark = (x)->num_active; \
402 } while (0)
403 #define STATS_INC_ERR(x) ((x)->errors++)
404 #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
405 #define STATS_INC_NODEFREES(x) ((x)->node_frees++)
406 #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
407 #define STATS_SET_FREEABLE(x, i) \
408 do { \
409 if ((x)->max_freeable < i) \
410 (x)->max_freeable = i; \
411 } while (0)
412 #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
413 #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
414 #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
415 #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
416 #else
417 #define STATS_INC_ACTIVE(x) do { } while (0)
418 #define STATS_DEC_ACTIVE(x) do { } while (0)
419 #define STATS_INC_ALLOCED(x) do { } while (0)
420 #define STATS_INC_GROWN(x) do { } while (0)
421 #define STATS_ADD_REAPED(x,y) do { } while (0)
422 #define STATS_SET_HIGH(x) do { } while (0)
423 #define STATS_INC_ERR(x) do { } while (0)
424 #define STATS_INC_NODEALLOCS(x) do { } while (0)
425 #define STATS_INC_NODEFREES(x) do { } while (0)
426 #define STATS_INC_ACOVERFLOW(x) do { } while (0)
427 #define STATS_SET_FREEABLE(x, i) do { } while (0)
428 #define STATS_INC_ALLOCHIT(x) do { } while (0)
429 #define STATS_INC_ALLOCMISS(x) do { } while (0)
430 #define STATS_INC_FREEHIT(x) do { } while (0)
431 #define STATS_INC_FREEMISS(x) do { } while (0)
432 #endif
434 #if DEBUG
437 * memory layout of objects:
438 * 0 : objp
439 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
440 * the end of an object is aligned with the end of the real
441 * allocation. Catches writes behind the end of the allocation.
442 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
443 * redzone word.
444 * cachep->obj_offset: The real object.
445 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
446 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
447 * [BYTES_PER_WORD long]
449 static int obj_offset(struct kmem_cache *cachep)
451 return cachep->obj_offset;
454 static int obj_size(struct kmem_cache *cachep)
456 return cachep->obj_size;
459 static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
461 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
462 return (unsigned long long*) (objp + obj_offset(cachep) -
463 sizeof(unsigned long long));
466 static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
468 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
469 if (cachep->flags & SLAB_STORE_USER)
470 return (unsigned long long *)(objp + cachep->buffer_size -
471 sizeof(unsigned long long) -
472 REDZONE_ALIGN);
473 return (unsigned long long *) (objp + cachep->buffer_size -
474 sizeof(unsigned long long));
477 static void **dbg_userword(struct kmem_cache *cachep, void *objp)
479 BUG_ON(!(cachep->flags & SLAB_STORE_USER));
480 return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD);
483 #else
485 #define obj_offset(x) 0
486 #define obj_size(cachep) (cachep->buffer_size)
487 #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
488 #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
489 #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
491 #endif
493 #ifdef CONFIG_TRACING
494 size_t slab_buffer_size(struct kmem_cache *cachep)
496 return cachep->buffer_size;
498 EXPORT_SYMBOL(slab_buffer_size);
499 #endif
502 * Do not go above this order unless 0 objects fit into the slab.
504 #define BREAK_GFP_ORDER_HI 1
505 #define BREAK_GFP_ORDER_LO 0
506 static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
509 * Functions for storing/retrieving the cachep and or slab from the page
510 * allocator. These are used to find the slab an obj belongs to. With kfree(),
511 * these are used to find the cache which an obj belongs to.
513 static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
515 page->lru.next = (struct list_head *)cache;
518 static inline struct kmem_cache *page_get_cache(struct page *page)
520 page = compound_head(page);
521 BUG_ON(!PageSlab(page));
522 return (struct kmem_cache *)page->lru.next;
525 static inline void page_set_slab(struct page *page, struct slab *slab)
527 page->lru.prev = (struct list_head *)slab;
530 static inline struct slab *page_get_slab(struct page *page)
532 BUG_ON(!PageSlab(page));
533 return (struct slab *)page->lru.prev;
536 static inline struct kmem_cache *virt_to_cache(const void *obj)
538 struct page *page = virt_to_head_page(obj);
539 return page_get_cache(page);
542 static inline struct slab *virt_to_slab(const void *obj)
544 struct page *page = virt_to_head_page(obj);
545 return page_get_slab(page);
548 static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
549 unsigned int idx)
551 return slab->s_mem + cache->buffer_size * idx;
555 * We want to avoid an expensive divide : (offset / cache->buffer_size)
556 * Using the fact that buffer_size is a constant for a particular cache,
557 * we can replace (offset / cache->buffer_size) by
558 * reciprocal_divide(offset, cache->reciprocal_buffer_size)
560 static inline unsigned int obj_to_index(const struct kmem_cache *cache,
561 const struct slab *slab, void *obj)
563 u32 offset = (obj - slab->s_mem);
564 return reciprocal_divide(offset, cache->reciprocal_buffer_size);
568 * These are the default caches for kmalloc. Custom caches can have other sizes.
570 struct cache_sizes malloc_sizes[] = {
571 #define CACHE(x) { .cs_size = (x) },
572 #include <linux/kmalloc_sizes.h>
573 CACHE(ULONG_MAX)
574 #undef CACHE
576 EXPORT_SYMBOL(malloc_sizes);
578 /* Must match cache_sizes above. Out of line to keep cache footprint low. */
579 struct cache_names {
580 char *name;
581 char *name_dma;
584 static struct cache_names __initdata cache_names[] = {
585 #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
586 #include <linux/kmalloc_sizes.h>
587 {NULL,}
588 #undef CACHE
591 static struct arraycache_init initarray_cache __initdata =
592 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
593 static struct arraycache_init initarray_generic =
594 { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} };
596 /* internal cache of cache description objs */
597 static struct kmem_cache cache_cache = {
598 .batchcount = 1,
599 .limit = BOOT_CPUCACHE_ENTRIES,
600 .shared = 1,
601 .buffer_size = sizeof(struct kmem_cache),
602 .name = "kmem_cache",
605 #define BAD_ALIEN_MAGIC 0x01020304ul
608 * chicken and egg problem: delay the per-cpu array allocation
609 * until the general caches are up.
611 static enum {
612 NONE,
613 PARTIAL_AC,
614 PARTIAL_L3,
615 EARLY,
616 FULL
617 } g_cpucache_up;
620 * used by boot code to determine if it can use slab based allocator
622 int slab_is_available(void)
624 return g_cpucache_up >= EARLY;
627 #ifdef CONFIG_LOCKDEP
630 * Slab sometimes uses the kmalloc slabs to store the slab headers
631 * for other slabs "off slab".
632 * The locking for this is tricky in that it nests within the locks
633 * of all other slabs in a few places; to deal with this special
634 * locking we put on-slab caches into a separate lock-class.
636 * We set lock class for alien array caches which are up during init.
637 * The lock annotation will be lost if all cpus of a node goes down and
638 * then comes back up during hotplug
640 static struct lock_class_key on_slab_l3_key;
641 static struct lock_class_key on_slab_alc_key;
643 static void init_node_lock_keys(int q)
645 struct cache_sizes *s = malloc_sizes;
647 if (g_cpucache_up != FULL)
648 return;
650 for (s = malloc_sizes; s->cs_size != ULONG_MAX; s++) {
651 struct array_cache **alc;
652 struct kmem_list3 *l3;
653 int r;
655 l3 = s->cs_cachep->nodelists[q];
656 if (!l3 || OFF_SLAB(s->cs_cachep))
657 return;
658 lockdep_set_class(&l3->list_lock, &on_slab_l3_key);
659 alc = l3->alien;
661 * FIXME: This check for BAD_ALIEN_MAGIC
662 * should go away when common slab code is taught to
663 * work even without alien caches.
664 * Currently, non NUMA code returns BAD_ALIEN_MAGIC
665 * for alloc_alien_cache,
667 if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC)
668 return;
669 for_each_node(r) {
670 if (alc[r])
671 lockdep_set_class(&alc[r]->lock,
672 &on_slab_alc_key);
677 static inline void init_lock_keys(void)
679 int node;
681 for_each_node(node)
682 init_node_lock_keys(node);
684 #else
685 static void init_node_lock_keys(int q)
689 static inline void init_lock_keys(void)
692 #endif
695 * Guard access to the cache-chain.
697 static DEFINE_MUTEX(cache_chain_mutex);
698 static struct list_head cache_chain;
700 static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
702 static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
704 return cachep->array[smp_processor_id()];
707 static inline struct kmem_cache *__find_general_cachep(size_t size,
708 gfp_t gfpflags)
710 struct cache_sizes *csizep = malloc_sizes;
712 #if DEBUG
713 /* This happens if someone tries to call
714 * kmem_cache_create(), or __kmalloc(), before
715 * the generic caches are initialized.
717 BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL);
718 #endif
719 if (!size)
720 return ZERO_SIZE_PTR;
722 while (size > csizep->cs_size)
723 csizep++;
726 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
727 * has cs_{dma,}cachep==NULL. Thus no special case
728 * for large kmalloc calls required.
730 #ifdef CONFIG_ZONE_DMA
731 if (unlikely(gfpflags & GFP_DMA))
732 return csizep->cs_dmacachep;
733 #endif
734 return csizep->cs_cachep;
737 static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags)
739 return __find_general_cachep(size, gfpflags);
742 static size_t slab_mgmt_size(size_t nr_objs, size_t align)
744 return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
748 * Calculate the number of objects and left-over bytes for a given buffer size.
750 static void cache_estimate(unsigned long gfporder, size_t buffer_size,
751 size_t align, int flags, size_t *left_over,
752 unsigned int *num)
754 int nr_objs;
755 size_t mgmt_size;
756 size_t slab_size = PAGE_SIZE << gfporder;
759 * The slab management structure can be either off the slab or
760 * on it. For the latter case, the memory allocated for a
761 * slab is used for:
763 * - The struct slab
764 * - One kmem_bufctl_t for each object
765 * - Padding to respect alignment of @align
766 * - @buffer_size bytes for each object
768 * If the slab management structure is off the slab, then the
769 * alignment will already be calculated into the size. Because
770 * the slabs are all pages aligned, the objects will be at the
771 * correct alignment when allocated.
773 if (flags & CFLGS_OFF_SLAB) {
774 mgmt_size = 0;
775 nr_objs = slab_size / buffer_size;
777 if (nr_objs > SLAB_LIMIT)
778 nr_objs = SLAB_LIMIT;
779 } else {
781 * Ignore padding for the initial guess. The padding
782 * is at most @align-1 bytes, and @buffer_size is at
783 * least @align. In the worst case, this result will
784 * be one greater than the number of objects that fit
785 * into the memory allocation when taking the padding
786 * into account.
788 nr_objs = (slab_size - sizeof(struct slab)) /
789 (buffer_size + sizeof(kmem_bufctl_t));
792 * This calculated number will be either the right
793 * amount, or one greater than what we want.
795 if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size
796 > slab_size)
797 nr_objs--;
799 if (nr_objs > SLAB_LIMIT)
800 nr_objs = SLAB_LIMIT;
802 mgmt_size = slab_mgmt_size(nr_objs, align);
804 *num = nr_objs;
805 *left_over = slab_size - nr_objs*buffer_size - mgmt_size;
808 #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
810 static void __slab_error(const char *function, struct kmem_cache *cachep,
811 char *msg)
813 printk(KERN_ERR "slab error in %s(): cache `%s': %s\n",
814 function, cachep->name, msg);
815 dump_stack();
819 * By default on NUMA we use alien caches to stage the freeing of
820 * objects allocated from other nodes. This causes massive memory
821 * inefficiencies when using fake NUMA setup to split memory into a
822 * large number of small nodes, so it can be disabled on the command
823 * line
826 static int use_alien_caches __read_mostly = 1;
827 static int __init noaliencache_setup(char *s)
829 use_alien_caches = 0;
830 return 1;
832 __setup("noaliencache", noaliencache_setup);
834 #ifdef CONFIG_NUMA
836 * Special reaping functions for NUMA systems called from cache_reap().
837 * These take care of doing round robin flushing of alien caches (containing
838 * objects freed on different nodes from which they were allocated) and the
839 * flushing of remote pcps by calling drain_node_pages.
841 static DEFINE_PER_CPU(unsigned long, slab_reap_node);
843 static void init_reap_node(int cpu)
845 int node;
847 node = next_node(cpu_to_node(cpu), node_online_map);
848 if (node == MAX_NUMNODES)
849 node = first_node(node_online_map);
851 per_cpu(slab_reap_node, cpu) = node;
854 static void next_reap_node(void)
856 int node = __get_cpu_var(slab_reap_node);
858 node = next_node(node, node_online_map);
859 if (unlikely(node >= MAX_NUMNODES))
860 node = first_node(node_online_map);
861 __get_cpu_var(slab_reap_node) = node;
864 #else
865 #define init_reap_node(cpu) do { } while (0)
866 #define next_reap_node(void) do { } while (0)
867 #endif
870 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
871 * via the workqueue/eventd.
872 * Add the CPU number into the expiration time to minimize the possibility of
873 * the CPUs getting into lockstep and contending for the global cache chain
874 * lock.
876 static void __cpuinit start_cpu_timer(int cpu)
878 struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu);
881 * When this gets called from do_initcalls via cpucache_init(),
882 * init_workqueues() has already run, so keventd will be setup
883 * at that time.
885 if (keventd_up() && reap_work->work.func == NULL) {
886 init_reap_node(cpu);
887 INIT_DELAYED_WORK(reap_work, cache_reap);
888 schedule_delayed_work_on(cpu, reap_work,
889 __round_jiffies_relative(HZ, cpu));
893 static struct array_cache *alloc_arraycache(int node, int entries,
894 int batchcount, gfp_t gfp)
896 int memsize = sizeof(void *) * entries + sizeof(struct array_cache);
897 struct array_cache *nc = NULL;
899 nc = kmalloc_node(memsize, gfp, node);
901 * The array_cache structures contain pointers to free object.
902 * However, when such objects are allocated or transfered to another
903 * cache the pointers are not cleared and they could be counted as
904 * valid references during a kmemleak scan. Therefore, kmemleak must
905 * not scan such objects.
907 kmemleak_no_scan(nc);
908 if (nc) {
909 nc->avail = 0;
910 nc->limit = entries;
911 nc->batchcount = batchcount;
912 nc->touched = 0;
913 spin_lock_init(&nc->lock);
915 return nc;
919 * Transfer objects in one arraycache to another.
920 * Locking must be handled by the caller.
922 * Return the number of entries transferred.
924 static int transfer_objects(struct array_cache *to,
925 struct array_cache *from, unsigned int max)
927 /* Figure out how many entries to transfer */
928 int nr = min(min(from->avail, max), to->limit - to->avail);
930 if (!nr)
931 return 0;
933 memcpy(to->entry + to->avail, from->entry + from->avail -nr,
934 sizeof(void *) *nr);
936 from->avail -= nr;
937 to->avail += nr;
938 to->touched = 1;
939 return nr;
942 #ifndef CONFIG_NUMA
944 #define drain_alien_cache(cachep, alien) do { } while (0)
945 #define reap_alien(cachep, l3) do { } while (0)
947 static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
949 return (struct array_cache **)BAD_ALIEN_MAGIC;
952 static inline void free_alien_cache(struct array_cache **ac_ptr)
956 static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
958 return 0;
961 static inline void *alternate_node_alloc(struct kmem_cache *cachep,
962 gfp_t flags)
964 return NULL;
967 static inline void *____cache_alloc_node(struct kmem_cache *cachep,
968 gfp_t flags, int nodeid)
970 return NULL;
973 #else /* CONFIG_NUMA */
975 static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
976 static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
978 static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
980 struct array_cache **ac_ptr;
981 int memsize = sizeof(void *) * nr_node_ids;
982 int i;
984 if (limit > 1)
985 limit = 12;
986 ac_ptr = kmalloc_node(memsize, gfp, node);
987 if (ac_ptr) {
988 for_each_node(i) {
989 if (i == node || !node_online(i)) {
990 ac_ptr[i] = NULL;
991 continue;
993 ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp);
994 if (!ac_ptr[i]) {
995 for (i--; i >= 0; i--)
996 kfree(ac_ptr[i]);
997 kfree(ac_ptr);
998 return NULL;
1002 return ac_ptr;
1005 static void free_alien_cache(struct array_cache **ac_ptr)
1007 int i;
1009 if (!ac_ptr)
1010 return;
1011 for_each_node(i)
1012 kfree(ac_ptr[i]);
1013 kfree(ac_ptr);
1016 static void __drain_alien_cache(struct kmem_cache *cachep,
1017 struct array_cache *ac, int node)
1019 struct kmem_list3 *rl3 = cachep->nodelists[node];
1021 if (ac->avail) {
1022 spin_lock(&rl3->list_lock);
1024 * Stuff objects into the remote nodes shared array first.
1025 * That way we could avoid the overhead of putting the objects
1026 * into the free lists and getting them back later.
1028 if (rl3->shared)
1029 transfer_objects(rl3->shared, ac, ac->limit);
1031 free_block(cachep, ac->entry, ac->avail, node);
1032 ac->avail = 0;
1033 spin_unlock(&rl3->list_lock);
1038 * Called from cache_reap() to regularly drain alien caches round robin.
1040 static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3)
1042 int node = __get_cpu_var(slab_reap_node);
1044 if (l3->alien) {
1045 struct array_cache *ac = l3->alien[node];
1047 if (ac && ac->avail && spin_trylock_irq(&ac->lock)) {
1048 __drain_alien_cache(cachep, ac, node);
1049 spin_unlock_irq(&ac->lock);
1054 static void drain_alien_cache(struct kmem_cache *cachep,
1055 struct array_cache **alien)
1057 int i = 0;
1058 struct array_cache *ac;
1059 unsigned long flags;
1061 for_each_online_node(i) {
1062 ac = alien[i];
1063 if (ac) {
1064 spin_lock_irqsave(&ac->lock, flags);
1065 __drain_alien_cache(cachep, ac, i);
1066 spin_unlock_irqrestore(&ac->lock, flags);
1071 static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
1073 struct slab *slabp = virt_to_slab(objp);
1074 int nodeid = slabp->nodeid;
1075 struct kmem_list3 *l3;
1076 struct array_cache *alien = NULL;
1077 int node;
1079 node = numa_node_id();
1082 * Make sure we are not freeing a object from another node to the array
1083 * cache on this cpu.
1085 if (likely(slabp->nodeid == node))
1086 return 0;
1088 l3 = cachep->nodelists[node];
1089 STATS_INC_NODEFREES(cachep);
1090 if (l3->alien && l3->alien[nodeid]) {
1091 alien = l3->alien[nodeid];
1092 spin_lock(&alien->lock);
1093 if (unlikely(alien->avail == alien->limit)) {
1094 STATS_INC_ACOVERFLOW(cachep);
1095 __drain_alien_cache(cachep, alien, nodeid);
1097 alien->entry[alien->avail++] = objp;
1098 spin_unlock(&alien->lock);
1099 } else {
1100 spin_lock(&(cachep->nodelists[nodeid])->list_lock);
1101 free_block(cachep, &objp, 1, nodeid);
1102 spin_unlock(&(cachep->nodelists[nodeid])->list_lock);
1104 return 1;
1106 #endif
1108 static void __cpuinit cpuup_canceled(long cpu)
1110 struct kmem_cache *cachep;
1111 struct kmem_list3 *l3 = NULL;
1112 int node = cpu_to_node(cpu);
1113 const struct cpumask *mask = cpumask_of_node(node);
1115 list_for_each_entry(cachep, &cache_chain, next) {
1116 struct array_cache *nc;
1117 struct array_cache *shared;
1118 struct array_cache **alien;
1120 /* cpu is dead; no one can alloc from it. */
1121 nc = cachep->array[cpu];
1122 cachep->array[cpu] = NULL;
1123 l3 = cachep->nodelists[node];
1125 if (!l3)
1126 goto free_array_cache;
1128 spin_lock_irq(&l3->list_lock);
1130 /* Free limit for this kmem_list3 */
1131 l3->free_limit -= cachep->batchcount;
1132 if (nc)
1133 free_block(cachep, nc->entry, nc->avail, node);
1135 if (!cpus_empty(*mask)) {
1136 spin_unlock_irq(&l3->list_lock);
1137 goto free_array_cache;
1140 shared = l3->shared;
1141 if (shared) {
1142 free_block(cachep, shared->entry,
1143 shared->avail, node);
1144 l3->shared = NULL;
1147 alien = l3->alien;
1148 l3->alien = NULL;
1150 spin_unlock_irq(&l3->list_lock);
1152 kfree(shared);
1153 if (alien) {
1154 drain_alien_cache(cachep, alien);
1155 free_alien_cache(alien);
1157 free_array_cache:
1158 kfree(nc);
1161 * In the previous loop, all the objects were freed to
1162 * the respective cache's slabs, now we can go ahead and
1163 * shrink each nodelist to its limit.
1165 list_for_each_entry(cachep, &cache_chain, next) {
1166 l3 = cachep->nodelists[node];
1167 if (!l3)
1168 continue;
1169 drain_freelist(cachep, l3, l3->free_objects);
1173 static int __cpuinit cpuup_prepare(long cpu)
1175 struct kmem_cache *cachep;
1176 struct kmem_list3 *l3 = NULL;
1177 int node = cpu_to_node(cpu);
1178 const int memsize = sizeof(struct kmem_list3);
1181 * We need to do this right in the beginning since
1182 * alloc_arraycache's are going to use this list.
1183 * kmalloc_node allows us to add the slab to the right
1184 * kmem_list3 and not this cpu's kmem_list3
1187 list_for_each_entry(cachep, &cache_chain, next) {
1189 * Set up the size64 kmemlist for cpu before we can
1190 * begin anything. Make sure some other cpu on this
1191 * node has not already allocated this
1193 if (!cachep->nodelists[node]) {
1194 l3 = kmalloc_node(memsize, GFP_KERNEL, node);
1195 if (!l3)
1196 goto bad;
1197 kmem_list3_init(l3);
1198 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
1199 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1202 * The l3s don't come and go as CPUs come and
1203 * go. cache_chain_mutex is sufficient
1204 * protection here.
1206 cachep->nodelists[node] = l3;
1209 spin_lock_irq(&cachep->nodelists[node]->list_lock);
1210 cachep->nodelists[node]->free_limit =
1211 (1 + nr_cpus_node(node)) *
1212 cachep->batchcount + cachep->num;
1213 spin_unlock_irq(&cachep->nodelists[node]->list_lock);
1217 * Now we can go ahead with allocating the shared arrays and
1218 * array caches
1220 list_for_each_entry(cachep, &cache_chain, next) {
1221 struct array_cache *nc;
1222 struct array_cache *shared = NULL;
1223 struct array_cache **alien = NULL;
1225 nc = alloc_arraycache(node, cachep->limit,
1226 cachep->batchcount, GFP_KERNEL);
1227 if (!nc)
1228 goto bad;
1229 if (cachep->shared) {
1230 shared = alloc_arraycache(node,
1231 cachep->shared * cachep->batchcount,
1232 0xbaadf00d, GFP_KERNEL);
1233 if (!shared) {
1234 kfree(nc);
1235 goto bad;
1238 if (use_alien_caches) {
1239 alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL);
1240 if (!alien) {
1241 kfree(shared);
1242 kfree(nc);
1243 goto bad;
1246 cachep->array[cpu] = nc;
1247 l3 = cachep->nodelists[node];
1248 BUG_ON(!l3);
1250 spin_lock_irq(&l3->list_lock);
1251 if (!l3->shared) {
1253 * We are serialised from CPU_DEAD or
1254 * CPU_UP_CANCELLED by the cpucontrol lock
1256 l3->shared = shared;
1257 shared = NULL;
1259 #ifdef CONFIG_NUMA
1260 if (!l3->alien) {
1261 l3->alien = alien;
1262 alien = NULL;
1264 #endif
1265 spin_unlock_irq(&l3->list_lock);
1266 kfree(shared);
1267 free_alien_cache(alien);
1269 init_node_lock_keys(node);
1271 return 0;
1272 bad:
1273 cpuup_canceled(cpu);
1274 return -ENOMEM;
1277 static int __cpuinit cpuup_callback(struct notifier_block *nfb,
1278 unsigned long action, void *hcpu)
1280 long cpu = (long)hcpu;
1281 int err = 0;
1283 switch (action) {
1284 case CPU_UP_PREPARE:
1285 case CPU_UP_PREPARE_FROZEN:
1286 mutex_lock(&cache_chain_mutex);
1287 err = cpuup_prepare(cpu);
1288 mutex_unlock(&cache_chain_mutex);
1289 break;
1290 case CPU_ONLINE:
1291 case CPU_ONLINE_FROZEN:
1292 start_cpu_timer(cpu);
1293 break;
1294 #ifdef CONFIG_HOTPLUG_CPU
1295 case CPU_DOWN_PREPARE:
1296 case CPU_DOWN_PREPARE_FROZEN:
1298 * Shutdown cache reaper. Note that the cache_chain_mutex is
1299 * held so that if cache_reap() is invoked it cannot do
1300 * anything expensive but will only modify reap_work
1301 * and reschedule the timer.
1303 cancel_rearming_delayed_work(&per_cpu(slab_reap_work, cpu));
1304 /* Now the cache_reaper is guaranteed to be not running. */
1305 per_cpu(slab_reap_work, cpu).work.func = NULL;
1306 break;
1307 case CPU_DOWN_FAILED:
1308 case CPU_DOWN_FAILED_FROZEN:
1309 start_cpu_timer(cpu);
1310 break;
1311 case CPU_DEAD:
1312 case CPU_DEAD_FROZEN:
1314 * Even if all the cpus of a node are down, we don't free the
1315 * kmem_list3 of any cache. This to avoid a race between
1316 * cpu_down, and a kmalloc allocation from another cpu for
1317 * memory from the node of the cpu going down. The list3
1318 * structure is usually allocated from kmem_cache_create() and
1319 * gets destroyed at kmem_cache_destroy().
1321 /* fall through */
1322 #endif
1323 case CPU_UP_CANCELED:
1324 case CPU_UP_CANCELED_FROZEN:
1325 mutex_lock(&cache_chain_mutex);
1326 cpuup_canceled(cpu);
1327 mutex_unlock(&cache_chain_mutex);
1328 break;
1330 return err ? NOTIFY_BAD : NOTIFY_OK;
1333 static struct notifier_block __cpuinitdata cpucache_notifier = {
1334 &cpuup_callback, NULL, 0
1338 * swap the static kmem_list3 with kmalloced memory
1340 static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list,
1341 int nodeid)
1343 struct kmem_list3 *ptr;
1345 ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_NOWAIT, nodeid);
1346 BUG_ON(!ptr);
1348 memcpy(ptr, list, sizeof(struct kmem_list3));
1350 * Do not assume that spinlocks can be initialized via memcpy:
1352 spin_lock_init(&ptr->list_lock);
1354 MAKE_ALL_LISTS(cachep, ptr, nodeid);
1355 cachep->nodelists[nodeid] = ptr;
1359 * For setting up all the kmem_list3s for cache whose buffer_size is same as
1360 * size of kmem_list3.
1362 static void __init set_up_list3s(struct kmem_cache *cachep, int index)
1364 int node;
1366 for_each_online_node(node) {
1367 cachep->nodelists[node] = &initkmem_list3[index + node];
1368 cachep->nodelists[node]->next_reap = jiffies +
1369 REAPTIMEOUT_LIST3 +
1370 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
1375 * Initialisation. Called after the page allocator have been initialised and
1376 * before smp_init().
1378 void __init kmem_cache_init(void)
1380 size_t left_over;
1381 struct cache_sizes *sizes;
1382 struct cache_names *names;
1383 int i;
1384 int order;
1385 int node;
1387 if (num_possible_nodes() == 1)
1388 use_alien_caches = 0;
1390 for (i = 0; i < NUM_INIT_LISTS; i++) {
1391 kmem_list3_init(&initkmem_list3[i]);
1392 if (i < MAX_NUMNODES)
1393 cache_cache.nodelists[i] = NULL;
1395 set_up_list3s(&cache_cache, CACHE_CACHE);
1398 * Fragmentation resistance on low memory - only use bigger
1399 * page orders on machines with more than 32MB of memory.
1401 if (totalram_pages > (32 << 20) >> PAGE_SHIFT)
1402 slab_break_gfp_order = BREAK_GFP_ORDER_HI;
1404 /* Bootstrap is tricky, because several objects are allocated
1405 * from caches that do not exist yet:
1406 * 1) initialize the cache_cache cache: it contains the struct
1407 * kmem_cache structures of all caches, except cache_cache itself:
1408 * cache_cache is statically allocated.
1409 * Initially an __init data area is used for the head array and the
1410 * kmem_list3 structures, it's replaced with a kmalloc allocated
1411 * array at the end of the bootstrap.
1412 * 2) Create the first kmalloc cache.
1413 * The struct kmem_cache for the new cache is allocated normally.
1414 * An __init data area is used for the head array.
1415 * 3) Create the remaining kmalloc caches, with minimally sized
1416 * head arrays.
1417 * 4) Replace the __init data head arrays for cache_cache and the first
1418 * kmalloc cache with kmalloc allocated arrays.
1419 * 5) Replace the __init data for kmem_list3 for cache_cache and
1420 * the other cache's with kmalloc allocated memory.
1421 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1424 node = numa_node_id();
1426 /* 1) create the cache_cache */
1427 INIT_LIST_HEAD(&cache_chain);
1428 list_add(&cache_cache.next, &cache_chain);
1429 cache_cache.colour_off = cache_line_size();
1430 cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
1431 cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE + node];
1434 * struct kmem_cache size depends on nr_node_ids, which
1435 * can be less than MAX_NUMNODES.
1437 cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) +
1438 nr_node_ids * sizeof(struct kmem_list3 *);
1439 #if DEBUG
1440 cache_cache.obj_size = cache_cache.buffer_size;
1441 #endif
1442 cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
1443 cache_line_size());
1444 cache_cache.reciprocal_buffer_size =
1445 reciprocal_value(cache_cache.buffer_size);
1447 for (order = 0; order < MAX_ORDER; order++) {
1448 cache_estimate(order, cache_cache.buffer_size,
1449 cache_line_size(), 0, &left_over, &cache_cache.num);
1450 if (cache_cache.num)
1451 break;
1453 BUG_ON(!cache_cache.num);
1454 cache_cache.gfporder = order;
1455 cache_cache.colour = left_over / cache_cache.colour_off;
1456 cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) +
1457 sizeof(struct slab), cache_line_size());
1459 /* 2+3) create the kmalloc caches */
1460 sizes = malloc_sizes;
1461 names = cache_names;
1464 * Initialize the caches that provide memory for the array cache and the
1465 * kmem_list3 structures first. Without this, further allocations will
1466 * bug.
1469 sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name,
1470 sizes[INDEX_AC].cs_size,
1471 ARCH_KMALLOC_MINALIGN,
1472 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1473 NULL);
1475 if (INDEX_AC != INDEX_L3) {
1476 sizes[INDEX_L3].cs_cachep =
1477 kmem_cache_create(names[INDEX_L3].name,
1478 sizes[INDEX_L3].cs_size,
1479 ARCH_KMALLOC_MINALIGN,
1480 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1481 NULL);
1484 slab_early_init = 0;
1486 while (sizes->cs_size != ULONG_MAX) {
1488 * For performance, all the general caches are L1 aligned.
1489 * This should be particularly beneficial on SMP boxes, as it
1490 * eliminates "false sharing".
1491 * Note for systems short on memory removing the alignment will
1492 * allow tighter packing of the smaller caches.
1494 if (!sizes->cs_cachep) {
1495 sizes->cs_cachep = kmem_cache_create(names->name,
1496 sizes->cs_size,
1497 ARCH_KMALLOC_MINALIGN,
1498 ARCH_KMALLOC_FLAGS|SLAB_PANIC,
1499 NULL);
1501 #ifdef CONFIG_ZONE_DMA
1502 sizes->cs_dmacachep = kmem_cache_create(
1503 names->name_dma,
1504 sizes->cs_size,
1505 ARCH_KMALLOC_MINALIGN,
1506 ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
1507 SLAB_PANIC,
1508 NULL);
1509 #endif
1510 sizes++;
1511 names++;
1513 /* 4) Replace the bootstrap head arrays */
1515 struct array_cache *ptr;
1517 ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT);
1519 BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache);
1520 memcpy(ptr, cpu_cache_get(&cache_cache),
1521 sizeof(struct arraycache_init));
1523 * Do not assume that spinlocks can be initialized via memcpy:
1525 spin_lock_init(&ptr->lock);
1527 cache_cache.array[smp_processor_id()] = ptr;
1529 ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT);
1531 BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep)
1532 != &initarray_generic.cache);
1533 memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep),
1534 sizeof(struct arraycache_init));
1536 * Do not assume that spinlocks can be initialized via memcpy:
1538 spin_lock_init(&ptr->lock);
1540 malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] =
1541 ptr;
1543 /* 5) Replace the bootstrap kmem_list3's */
1545 int nid;
1547 for_each_online_node(nid) {
1548 init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid);
1550 init_list(malloc_sizes[INDEX_AC].cs_cachep,
1551 &initkmem_list3[SIZE_AC + nid], nid);
1553 if (INDEX_AC != INDEX_L3) {
1554 init_list(malloc_sizes[INDEX_L3].cs_cachep,
1555 &initkmem_list3[SIZE_L3 + nid], nid);
1560 g_cpucache_up = EARLY;
1563 void __init kmem_cache_init_late(void)
1565 struct kmem_cache *cachep;
1567 /* 6) resize the head arrays to their final sizes */
1568 mutex_lock(&cache_chain_mutex);
1569 list_for_each_entry(cachep, &cache_chain, next)
1570 if (enable_cpucache(cachep, GFP_NOWAIT))
1571 BUG();
1572 mutex_unlock(&cache_chain_mutex);
1574 /* Done! */
1575 g_cpucache_up = FULL;
1577 /* Annotate slab for lockdep -- annotate the malloc caches */
1578 init_lock_keys();
1581 * Register a cpu startup notifier callback that initializes
1582 * cpu_cache_get for all new cpus
1584 register_cpu_notifier(&cpucache_notifier);
1587 * The reap timers are started later, with a module init call: That part
1588 * of the kernel is not yet operational.
1592 static int __init cpucache_init(void)
1594 int cpu;
1597 * Register the timers that return unneeded pages to the page allocator
1599 for_each_online_cpu(cpu)
1600 start_cpu_timer(cpu);
1601 return 0;
1603 __initcall(cpucache_init);
1606 * Interface to system's page allocator. No need to hold the cache-lock.
1608 * If we requested dmaable memory, we will get it. Even if we
1609 * did not request dmaable memory, we might get it, but that
1610 * would be relatively rare and ignorable.
1612 static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
1614 struct page *page;
1615 int nr_pages;
1616 int i;
1618 #ifndef CONFIG_MMU
1620 * Nommu uses slab's for process anonymous memory allocations, and thus
1621 * requires __GFP_COMP to properly refcount higher order allocations
1623 flags |= __GFP_COMP;
1624 #endif
1626 flags |= cachep->gfpflags;
1627 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1628 flags |= __GFP_RECLAIMABLE;
1630 page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
1631 if (!page)
1632 return NULL;
1634 nr_pages = (1 << cachep->gfporder);
1635 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1636 add_zone_page_state(page_zone(page),
1637 NR_SLAB_RECLAIMABLE, nr_pages);
1638 else
1639 add_zone_page_state(page_zone(page),
1640 NR_SLAB_UNRECLAIMABLE, nr_pages);
1641 for (i = 0; i < nr_pages; i++)
1642 __SetPageSlab(page + i);
1644 if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
1645 kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid);
1647 if (cachep->ctor)
1648 kmemcheck_mark_uninitialized_pages(page, nr_pages);
1649 else
1650 kmemcheck_mark_unallocated_pages(page, nr_pages);
1653 return page_address(page);
1657 * Interface to system's page release.
1659 static void kmem_freepages(struct kmem_cache *cachep, void *addr)
1661 unsigned long i = (1 << cachep->gfporder);
1662 struct page *page = virt_to_page(addr);
1663 const unsigned long nr_freed = i;
1665 kmemcheck_free_shadow(page, cachep->gfporder);
1667 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1668 sub_zone_page_state(page_zone(page),
1669 NR_SLAB_RECLAIMABLE, nr_freed);
1670 else
1671 sub_zone_page_state(page_zone(page),
1672 NR_SLAB_UNRECLAIMABLE, nr_freed);
1673 while (i--) {
1674 BUG_ON(!PageSlab(page));
1675 __ClearPageSlab(page);
1676 page++;
1678 if (current->reclaim_state)
1679 current->reclaim_state->reclaimed_slab += nr_freed;
1680 free_pages((unsigned long)addr, cachep->gfporder);
1683 static void kmem_rcu_free(struct rcu_head *head)
1685 struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
1686 struct kmem_cache *cachep = slab_rcu->cachep;
1688 kmem_freepages(cachep, slab_rcu->addr);
1689 if (OFF_SLAB(cachep))
1690 kmem_cache_free(cachep->slabp_cache, slab_rcu);
1693 #if DEBUG
1695 #ifdef CONFIG_DEBUG_PAGEALLOC
1696 static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
1697 unsigned long caller)
1699 int size = obj_size(cachep);
1701 addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
1703 if (size < 5 * sizeof(unsigned long))
1704 return;
1706 *addr++ = 0x12345678;
1707 *addr++ = caller;
1708 *addr++ = smp_processor_id();
1709 size -= 3 * sizeof(unsigned long);
1711 unsigned long *sptr = &caller;
1712 unsigned long svalue;
1714 while (!kstack_end(sptr)) {
1715 svalue = *sptr++;
1716 if (kernel_text_address(svalue)) {
1717 *addr++ = svalue;
1718 size -= sizeof(unsigned long);
1719 if (size <= sizeof(unsigned long))
1720 break;
1725 *addr++ = 0x87654321;
1727 #endif
1729 static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
1731 int size = obj_size(cachep);
1732 addr = &((char *)addr)[obj_offset(cachep)];
1734 memset(addr, val, size);
1735 *(unsigned char *)(addr + size - 1) = POISON_END;
1738 static void dump_line(char *data, int offset, int limit)
1740 int i;
1741 unsigned char error = 0;
1742 int bad_count = 0;
1744 printk(KERN_ERR "%03x:", offset);
1745 for (i = 0; i < limit; i++) {
1746 if (data[offset + i] != POISON_FREE) {
1747 error = data[offset + i];
1748 bad_count++;
1750 printk(" %02x", (unsigned char)data[offset + i]);
1752 printk("\n");
1754 if (bad_count == 1) {
1755 error ^= POISON_FREE;
1756 if (!(error & (error - 1))) {
1757 printk(KERN_ERR "Single bit error detected. Probably "
1758 "bad RAM.\n");
1759 #ifdef CONFIG_X86
1760 printk(KERN_ERR "Run memtest86+ or a similar memory "
1761 "test tool.\n");
1762 #else
1763 printk(KERN_ERR "Run a memory test tool.\n");
1764 #endif
1768 #endif
1770 #if DEBUG
1772 static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
1774 int i, size;
1775 char *realobj;
1777 if (cachep->flags & SLAB_RED_ZONE) {
1778 printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n",
1779 *dbg_redzone1(cachep, objp),
1780 *dbg_redzone2(cachep, objp));
1783 if (cachep->flags & SLAB_STORE_USER) {
1784 printk(KERN_ERR "Last user: [<%p>]",
1785 *dbg_userword(cachep, objp));
1786 print_symbol("(%s)",
1787 (unsigned long)*dbg_userword(cachep, objp));
1788 printk("\n");
1790 realobj = (char *)objp + obj_offset(cachep);
1791 size = obj_size(cachep);
1792 for (i = 0; i < size && lines; i += 16, lines--) {
1793 int limit;
1794 limit = 16;
1795 if (i + limit > size)
1796 limit = size - i;
1797 dump_line(realobj, i, limit);
1801 static void check_poison_obj(struct kmem_cache *cachep, void *objp)
1803 char *realobj;
1804 int size, i;
1805 int lines = 0;
1807 realobj = (char *)objp + obj_offset(cachep);
1808 size = obj_size(cachep);
1810 for (i = 0; i < size; i++) {
1811 char exp = POISON_FREE;
1812 if (i == size - 1)
1813 exp = POISON_END;
1814 if (realobj[i] != exp) {
1815 int limit;
1816 /* Mismatch ! */
1817 /* Print header */
1818 if (lines == 0) {
1819 printk(KERN_ERR
1820 "Slab corruption: %s start=%p, len=%d\n",
1821 cachep->name, realobj, size);
1822 print_objinfo(cachep, objp, 0);
1824 /* Hexdump the affected line */
1825 i = (i / 16) * 16;
1826 limit = 16;
1827 if (i + limit > size)
1828 limit = size - i;
1829 dump_line(realobj, i, limit);
1830 i += 16;
1831 lines++;
1832 /* Limit to 5 lines */
1833 if (lines > 5)
1834 break;
1837 if (lines != 0) {
1838 /* Print some data about the neighboring objects, if they
1839 * exist:
1841 struct slab *slabp = virt_to_slab(objp);
1842 unsigned int objnr;
1844 objnr = obj_to_index(cachep, slabp, objp);
1845 if (objnr) {
1846 objp = index_to_obj(cachep, slabp, objnr - 1);
1847 realobj = (char *)objp + obj_offset(cachep);
1848 printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
1849 realobj, size);
1850 print_objinfo(cachep, objp, 2);
1852 if (objnr + 1 < cachep->num) {
1853 objp = index_to_obj(cachep, slabp, objnr + 1);
1854 realobj = (char *)objp + obj_offset(cachep);
1855 printk(KERN_ERR "Next obj: start=%p, len=%d\n",
1856 realobj, size);
1857 print_objinfo(cachep, objp, 2);
1861 #endif
1863 #if DEBUG
1864 static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
1866 int i;
1867 for (i = 0; i < cachep->num; i++) {
1868 void *objp = index_to_obj(cachep, slabp, i);
1870 if (cachep->flags & SLAB_POISON) {
1871 #ifdef CONFIG_DEBUG_PAGEALLOC
1872 if (cachep->buffer_size % PAGE_SIZE == 0 &&
1873 OFF_SLAB(cachep))
1874 kernel_map_pages(virt_to_page(objp),
1875 cachep->buffer_size / PAGE_SIZE, 1);
1876 else
1877 check_poison_obj(cachep, objp);
1878 #else
1879 check_poison_obj(cachep, objp);
1880 #endif
1882 if (cachep->flags & SLAB_RED_ZONE) {
1883 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
1884 slab_error(cachep, "start of a freed object "
1885 "was overwritten");
1886 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
1887 slab_error(cachep, "end of a freed object "
1888 "was overwritten");
1892 #else
1893 static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
1896 #endif
1899 * slab_destroy - destroy and release all objects in a slab
1900 * @cachep: cache pointer being destroyed
1901 * @slabp: slab pointer being destroyed
1903 * Destroy all the objs in a slab, and release the mem back to the system.
1904 * Before calling the slab must have been unlinked from the cache. The
1905 * cache-lock is not held/needed.
1907 static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
1909 void *addr = slabp->s_mem - slabp->colouroff;
1911 slab_destroy_debugcheck(cachep, slabp);
1912 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
1913 struct slab_rcu *slab_rcu;
1915 slab_rcu = (struct slab_rcu *)slabp;
1916 slab_rcu->cachep = cachep;
1917 slab_rcu->addr = addr;
1918 call_rcu(&slab_rcu->head, kmem_rcu_free);
1919 } else {
1920 kmem_freepages(cachep, addr);
1921 if (OFF_SLAB(cachep))
1922 kmem_cache_free(cachep->slabp_cache, slabp);
1926 static void __kmem_cache_destroy(struct kmem_cache *cachep)
1928 int i;
1929 struct kmem_list3 *l3;
1931 for_each_online_cpu(i)
1932 kfree(cachep->array[i]);
1934 /* NUMA: free the list3 structures */
1935 for_each_online_node(i) {
1936 l3 = cachep->nodelists[i];
1937 if (l3) {
1938 kfree(l3->shared);
1939 free_alien_cache(l3->alien);
1940 kfree(l3);
1943 kmem_cache_free(&cache_cache, cachep);
1948 * calculate_slab_order - calculate size (page order) of slabs
1949 * @cachep: pointer to the cache that is being created
1950 * @size: size of objects to be created in this cache.
1951 * @align: required alignment for the objects.
1952 * @flags: slab allocation flags
1954 * Also calculates the number of objects per slab.
1956 * This could be made much more intelligent. For now, try to avoid using
1957 * high order pages for slabs. When the gfp() functions are more friendly
1958 * towards high-order requests, this should be changed.
1960 static size_t calculate_slab_order(struct kmem_cache *cachep,
1961 size_t size, size_t align, unsigned long flags)
1963 unsigned long offslab_limit;
1964 size_t left_over = 0;
1965 int gfporder;
1967 for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
1968 unsigned int num;
1969 size_t remainder;
1971 cache_estimate(gfporder, size, align, flags, &remainder, &num);
1972 if (!num)
1973 continue;
1975 if (flags & CFLGS_OFF_SLAB) {
1977 * Max number of objs-per-slab for caches which
1978 * use off-slab slabs. Needed to avoid a possible
1979 * looping condition in cache_grow().
1981 offslab_limit = size - sizeof(struct slab);
1982 offslab_limit /= sizeof(kmem_bufctl_t);
1984 if (num > offslab_limit)
1985 break;
1988 /* Found something acceptable - save it away */
1989 cachep->num = num;
1990 cachep->gfporder = gfporder;
1991 left_over = remainder;
1994 * A VFS-reclaimable slab tends to have most allocations
1995 * as GFP_NOFS and we really don't want to have to be allocating
1996 * higher-order pages when we are unable to shrink dcache.
1998 if (flags & SLAB_RECLAIM_ACCOUNT)
1999 break;
2002 * Large number of objects is good, but very large slabs are
2003 * currently bad for the gfp()s.
2005 if (gfporder >= slab_break_gfp_order)
2006 break;
2009 * Acceptable internal fragmentation?
2011 if (left_over * 8 <= (PAGE_SIZE << gfporder))
2012 break;
2014 return left_over;
2017 static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
2019 if (g_cpucache_up == FULL)
2020 return enable_cpucache(cachep, gfp);
2022 if (g_cpucache_up == NONE) {
2024 * Note: the first kmem_cache_create must create the cache
2025 * that's used by kmalloc(24), otherwise the creation of
2026 * further caches will BUG().
2028 cachep->array[smp_processor_id()] = &initarray_generic.cache;
2031 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
2032 * the first cache, then we need to set up all its list3s,
2033 * otherwise the creation of further caches will BUG().
2035 set_up_list3s(cachep, SIZE_AC);
2036 if (INDEX_AC == INDEX_L3)
2037 g_cpucache_up = PARTIAL_L3;
2038 else
2039 g_cpucache_up = PARTIAL_AC;
2040 } else {
2041 cachep->array[smp_processor_id()] =
2042 kmalloc(sizeof(struct arraycache_init), gfp);
2044 if (g_cpucache_up == PARTIAL_AC) {
2045 set_up_list3s(cachep, SIZE_L3);
2046 g_cpucache_up = PARTIAL_L3;
2047 } else {
2048 int node;
2049 for_each_online_node(node) {
2050 cachep->nodelists[node] =
2051 kmalloc_node(sizeof(struct kmem_list3),
2052 gfp, node);
2053 BUG_ON(!cachep->nodelists[node]);
2054 kmem_list3_init(cachep->nodelists[node]);
2058 cachep->nodelists[numa_node_id()]->next_reap =
2059 jiffies + REAPTIMEOUT_LIST3 +
2060 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
2062 cpu_cache_get(cachep)->avail = 0;
2063 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
2064 cpu_cache_get(cachep)->batchcount = 1;
2065 cpu_cache_get(cachep)->touched = 0;
2066 cachep->batchcount = 1;
2067 cachep->limit = BOOT_CPUCACHE_ENTRIES;
2068 return 0;
2072 * kmem_cache_create - Create a cache.
2073 * @name: A string which is used in /proc/slabinfo to identify this cache.
2074 * @size: The size of objects to be created in this cache.
2075 * @align: The required alignment for the objects.
2076 * @flags: SLAB flags
2077 * @ctor: A constructor for the objects.
2079 * Returns a ptr to the cache on success, NULL on failure.
2080 * Cannot be called within a int, but can be interrupted.
2081 * The @ctor is run when new pages are allocated by the cache.
2083 * @name must be valid until the cache is destroyed. This implies that
2084 * the module calling this has to destroy the cache before getting unloaded.
2085 * Note that kmem_cache_name() is not guaranteed to return the same pointer,
2086 * therefore applications must manage it themselves.
2088 * The flags are
2090 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2091 * to catch references to uninitialised memory.
2093 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2094 * for buffer overruns.
2096 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2097 * cacheline. This can be beneficial if you're counting cycles as closely
2098 * as davem.
2100 struct kmem_cache *
2101 kmem_cache_create (const char *name, size_t size, size_t align,
2102 unsigned long flags, void (*ctor)(void *))
2104 size_t left_over, slab_size, ralign;
2105 struct kmem_cache *cachep = NULL, *pc;
2106 gfp_t gfp;
2109 * Sanity checks... these are all serious usage bugs.
2111 if (!name || in_interrupt() || (size < BYTES_PER_WORD) ||
2112 size > KMALLOC_MAX_SIZE) {
2113 printk(KERN_ERR "%s: Early error in slab %s\n", __func__,
2114 name);
2115 BUG();
2119 * We use cache_chain_mutex to ensure a consistent view of
2120 * cpu_online_mask as well. Please see cpuup_callback
2122 if (slab_is_available()) {
2123 get_online_cpus();
2124 mutex_lock(&cache_chain_mutex);
2127 list_for_each_entry(pc, &cache_chain, next) {
2128 char tmp;
2129 int res;
2132 * This happens when the module gets unloaded and doesn't
2133 * destroy its slab cache and no-one else reuses the vmalloc
2134 * area of the module. Print a warning.
2136 res = probe_kernel_address(pc->name, tmp);
2137 if (res) {
2138 printk(KERN_ERR
2139 "SLAB: cache with size %d has lost its name\n",
2140 pc->buffer_size);
2141 continue;
2144 if (!strcmp(pc->name, name)) {
2145 printk(KERN_ERR
2146 "kmem_cache_create: duplicate cache %s\n", name);
2147 dump_stack();
2148 goto oops;
2152 #if DEBUG
2153 WARN_ON(strchr(name, ' ')); /* It confuses parsers */
2154 #if FORCED_DEBUG
2156 * Enable redzoning and last user accounting, except for caches with
2157 * large objects, if the increased size would increase the object size
2158 * above the next power of two: caches with object sizes just above a
2159 * power of two have a significant amount of internal fragmentation.
2161 if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
2162 2 * sizeof(unsigned long long)))
2163 flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
2164 if (!(flags & SLAB_DESTROY_BY_RCU))
2165 flags |= SLAB_POISON;
2166 #endif
2167 if (flags & SLAB_DESTROY_BY_RCU)
2168 BUG_ON(flags & SLAB_POISON);
2169 #endif
2171 * Always checks flags, a caller might be expecting debug support which
2172 * isn't available.
2174 BUG_ON(flags & ~CREATE_MASK);
2177 * Check that size is in terms of words. This is needed to avoid
2178 * unaligned accesses for some archs when redzoning is used, and makes
2179 * sure any on-slab bufctl's are also correctly aligned.
2181 if (size & (BYTES_PER_WORD - 1)) {
2182 size += (BYTES_PER_WORD - 1);
2183 size &= ~(BYTES_PER_WORD - 1);
2186 /* calculate the final buffer alignment: */
2188 /* 1) arch recommendation: can be overridden for debug */
2189 if (flags & SLAB_HWCACHE_ALIGN) {
2191 * Default alignment: as specified by the arch code. Except if
2192 * an object is really small, then squeeze multiple objects into
2193 * one cacheline.
2195 ralign = cache_line_size();
2196 while (size <= ralign / 2)
2197 ralign /= 2;
2198 } else {
2199 ralign = BYTES_PER_WORD;
2203 * Redzoning and user store require word alignment or possibly larger.
2204 * Note this will be overridden by architecture or caller mandated
2205 * alignment if either is greater than BYTES_PER_WORD.
2207 if (flags & SLAB_STORE_USER)
2208 ralign = BYTES_PER_WORD;
2210 if (flags & SLAB_RED_ZONE) {
2211 ralign = REDZONE_ALIGN;
2212 /* If redzoning, ensure that the second redzone is suitably
2213 * aligned, by adjusting the object size accordingly. */
2214 size += REDZONE_ALIGN - 1;
2215 size &= ~(REDZONE_ALIGN - 1);
2218 /* 2) arch mandated alignment */
2219 if (ralign < ARCH_SLAB_MINALIGN) {
2220 ralign = ARCH_SLAB_MINALIGN;
2222 /* 3) caller mandated alignment */
2223 if (ralign < align) {
2224 ralign = align;
2226 /* disable debug if necessary */
2227 if (ralign > __alignof__(unsigned long long))
2228 flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
2230 * 4) Store it.
2232 align = ralign;
2234 if (slab_is_available())
2235 gfp = GFP_KERNEL;
2236 else
2237 gfp = GFP_NOWAIT;
2239 /* Get cache's description obj. */
2240 cachep = kmem_cache_zalloc(&cache_cache, gfp);
2241 if (!cachep)
2242 goto oops;
2244 #if DEBUG
2245 cachep->obj_size = size;
2248 * Both debugging options require word-alignment which is calculated
2249 * into align above.
2251 if (flags & SLAB_RED_ZONE) {
2252 /* add space for red zone words */
2253 cachep->obj_offset += sizeof(unsigned long long);
2254 size += 2 * sizeof(unsigned long long);
2256 if (flags & SLAB_STORE_USER) {
2257 /* user store requires one word storage behind the end of
2258 * the real object. But if the second red zone needs to be
2259 * aligned to 64 bits, we must allow that much space.
2261 if (flags & SLAB_RED_ZONE)
2262 size += REDZONE_ALIGN;
2263 else
2264 size += BYTES_PER_WORD;
2266 #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
2267 if (size >= malloc_sizes[INDEX_L3 + 1].cs_size
2268 && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) {
2269 cachep->obj_offset += PAGE_SIZE - size;
2270 size = PAGE_SIZE;
2272 #endif
2273 #endif
2276 * Determine if the slab management is 'on' or 'off' slab.
2277 * (bootstrapping cannot cope with offslab caches so don't do
2278 * it too early on.)
2280 if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init)
2282 * Size is large, assume best to place the slab management obj
2283 * off-slab (should allow better packing of objs).
2285 flags |= CFLGS_OFF_SLAB;
2287 size = ALIGN(size, align);
2289 left_over = calculate_slab_order(cachep, size, align, flags);
2291 if (!cachep->num) {
2292 printk(KERN_ERR
2293 "kmem_cache_create: couldn't create cache %s.\n", name);
2294 kmem_cache_free(&cache_cache, cachep);
2295 cachep = NULL;
2296 goto oops;
2298 slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
2299 + sizeof(struct slab), align);
2302 * If the slab has been placed off-slab, and we have enough space then
2303 * move it on-slab. This is at the expense of any extra colouring.
2305 if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
2306 flags &= ~CFLGS_OFF_SLAB;
2307 left_over -= slab_size;
2310 if (flags & CFLGS_OFF_SLAB) {
2311 /* really off slab. No need for manual alignment */
2312 slab_size =
2313 cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
2315 #ifdef CONFIG_PAGE_POISONING
2316 /* If we're going to use the generic kernel_map_pages()
2317 * poisoning, then it's going to smash the contents of
2318 * the redzone and userword anyhow, so switch them off.
2320 if (size % PAGE_SIZE == 0 && flags & SLAB_POISON)
2321 flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
2322 #endif
2325 cachep->colour_off = cache_line_size();
2326 /* Offset must be a multiple of the alignment. */
2327 if (cachep->colour_off < align)
2328 cachep->colour_off = align;
2329 cachep->colour = left_over / cachep->colour_off;
2330 cachep->slab_size = slab_size;
2331 cachep->flags = flags;
2332 cachep->gfpflags = 0;
2333 if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
2334 cachep->gfpflags |= GFP_DMA;
2335 cachep->buffer_size = size;
2336 cachep->reciprocal_buffer_size = reciprocal_value(size);
2338 if (flags & CFLGS_OFF_SLAB) {
2339 cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u);
2341 * This is a possibility for one of the malloc_sizes caches.
2342 * But since we go off slab only for object size greater than
2343 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
2344 * this should not happen at all.
2345 * But leave a BUG_ON for some lucky dude.
2347 BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));
2349 cachep->ctor = ctor;
2350 cachep->name = name;
2352 if (setup_cpu_cache(cachep, gfp)) {
2353 __kmem_cache_destroy(cachep);
2354 cachep = NULL;
2355 goto oops;
2358 /* cache setup completed, link it into the list */
2359 list_add(&cachep->next, &cache_chain);
2360 oops:
2361 if (!cachep && (flags & SLAB_PANIC))
2362 panic("kmem_cache_create(): failed to create slab `%s'\n",
2363 name);
2364 if (slab_is_available()) {
2365 mutex_unlock(&cache_chain_mutex);
2366 put_online_cpus();
2368 return cachep;
2370 EXPORT_SYMBOL(kmem_cache_create);
2372 #if DEBUG
2373 static void check_irq_off(void)
2375 BUG_ON(!irqs_disabled());
2378 static void check_irq_on(void)
2380 BUG_ON(irqs_disabled());
2383 static void check_spinlock_acquired(struct kmem_cache *cachep)
2385 #ifdef CONFIG_SMP
2386 check_irq_off();
2387 assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock);
2388 #endif
2391 static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2393 #ifdef CONFIG_SMP
2394 check_irq_off();
2395 assert_spin_locked(&cachep->nodelists[node]->list_lock);
2396 #endif
2399 #else
2400 #define check_irq_off() do { } while(0)
2401 #define check_irq_on() do { } while(0)
2402 #define check_spinlock_acquired(x) do { } while(0)
2403 #define check_spinlock_acquired_node(x, y) do { } while(0)
2404 #endif
2406 static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
2407 struct array_cache *ac,
2408 int force, int node);
2410 static void do_drain(void *arg)
2412 struct kmem_cache *cachep = arg;
2413 struct array_cache *ac;
2414 int node = numa_node_id();
2416 check_irq_off();
2417 ac = cpu_cache_get(cachep);
2418 spin_lock(&cachep->nodelists[node]->list_lock);
2419 free_block(cachep, ac->entry, ac->avail, node);
2420 spin_unlock(&cachep->nodelists[node]->list_lock);
2421 ac->avail = 0;
2424 static void drain_cpu_caches(struct kmem_cache *cachep)
2426 struct kmem_list3 *l3;
2427 int node;
2429 on_each_cpu(do_drain, cachep, 1);
2430 check_irq_on();
2431 for_each_online_node(node) {
2432 l3 = cachep->nodelists[node];
2433 if (l3 && l3->alien)
2434 drain_alien_cache(cachep, l3->alien);
2437 for_each_online_node(node) {
2438 l3 = cachep->nodelists[node];
2439 if (l3)
2440 drain_array(cachep, l3, l3->shared, 1, node);
2445 * Remove slabs from the list of free slabs.
2446 * Specify the number of slabs to drain in tofree.
2448 * Returns the actual number of slabs released.
2450 static int drain_freelist(struct kmem_cache *cache,
2451 struct kmem_list3 *l3, int tofree)
2453 struct list_head *p;
2454 int nr_freed;
2455 struct slab *slabp;
2457 nr_freed = 0;
2458 while (nr_freed < tofree && !list_empty(&l3->slabs_free)) {
2460 spin_lock_irq(&l3->list_lock);
2461 p = l3->slabs_free.prev;
2462 if (p == &l3->slabs_free) {
2463 spin_unlock_irq(&l3->list_lock);
2464 goto out;
2467 slabp = list_entry(p, struct slab, list);
2468 #if DEBUG
2469 BUG_ON(slabp->inuse);
2470 #endif
2471 list_del(&slabp->list);
2473 * Safe to drop the lock. The slab is no longer linked
2474 * to the cache.
2476 l3->free_objects -= cache->num;
2477 spin_unlock_irq(&l3->list_lock);
2478 slab_destroy(cache, slabp);
2479 nr_freed++;
2481 out:
2482 return nr_freed;
2485 /* Called with cache_chain_mutex held to protect against cpu hotplug */
2486 static int __cache_shrink(struct kmem_cache *cachep)
2488 int ret = 0, i = 0;
2489 struct kmem_list3 *l3;
2491 drain_cpu_caches(cachep);
2493 check_irq_on();
2494 for_each_online_node(i) {
2495 l3 = cachep->nodelists[i];
2496 if (!l3)
2497 continue;
2499 drain_freelist(cachep, l3, l3->free_objects);
2501 ret += !list_empty(&l3->slabs_full) ||
2502 !list_empty(&l3->slabs_partial);
2504 return (ret ? 1 : 0);
2508 * kmem_cache_shrink - Shrink a cache.
2509 * @cachep: The cache to shrink.
2511 * Releases as many slabs as possible for a cache.
2512 * To help debugging, a zero exit status indicates all slabs were released.
2514 int kmem_cache_shrink(struct kmem_cache *cachep)
2516 int ret;
2517 BUG_ON(!cachep || in_interrupt());
2519 get_online_cpus();
2520 mutex_lock(&cache_chain_mutex);
2521 ret = __cache_shrink(cachep);
2522 mutex_unlock(&cache_chain_mutex);
2523 put_online_cpus();
2524 return ret;
2526 EXPORT_SYMBOL(kmem_cache_shrink);
2529 * kmem_cache_destroy - delete a cache
2530 * @cachep: the cache to destroy
2532 * Remove a &struct kmem_cache object from the slab cache.
2534 * It is expected this function will be called by a module when it is
2535 * unloaded. This will remove the cache completely, and avoid a duplicate
2536 * cache being allocated each time a module is loaded and unloaded, if the
2537 * module doesn't have persistent in-kernel storage across loads and unloads.
2539 * The cache must be empty before calling this function.
2541 * The caller must guarantee that noone will allocate memory from the cache
2542 * during the kmem_cache_destroy().
2544 void kmem_cache_destroy(struct kmem_cache *cachep)
2546 BUG_ON(!cachep || in_interrupt());
2548 /* Find the cache in the chain of caches. */
2549 get_online_cpus();
2550 mutex_lock(&cache_chain_mutex);
2552 * the chain is never empty, cache_cache is never destroyed
2554 list_del(&cachep->next);
2555 if (__cache_shrink(cachep)) {
2556 slab_error(cachep, "Can't free all objects");
2557 list_add(&cachep->next, &cache_chain);
2558 mutex_unlock(&cache_chain_mutex);
2559 put_online_cpus();
2560 return;
2563 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
2564 rcu_barrier();
2566 __kmem_cache_destroy(cachep);
2567 mutex_unlock(&cache_chain_mutex);
2568 put_online_cpus();
2570 EXPORT_SYMBOL(kmem_cache_destroy);
2573 * Get the memory for a slab management obj.
2574 * For a slab cache when the slab descriptor is off-slab, slab descriptors
2575 * always come from malloc_sizes caches. The slab descriptor cannot
2576 * come from the same cache which is getting created because,
2577 * when we are searching for an appropriate cache for these
2578 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
2579 * If we are creating a malloc_sizes cache here it would not be visible to
2580 * kmem_find_general_cachep till the initialization is complete.
2581 * Hence we cannot have slabp_cache same as the original cache.
2583 static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
2584 int colour_off, gfp_t local_flags,
2585 int nodeid)
2587 struct slab *slabp;
2589 if (OFF_SLAB(cachep)) {
2590 /* Slab management obj is off-slab. */
2591 slabp = kmem_cache_alloc_node(cachep->slabp_cache,
2592 local_flags, nodeid);
2594 * If the first object in the slab is leaked (it's allocated
2595 * but no one has a reference to it), we want to make sure
2596 * kmemleak does not treat the ->s_mem pointer as a reference
2597 * to the object. Otherwise we will not report the leak.
2599 kmemleak_scan_area(slabp, offsetof(struct slab, list),
2600 sizeof(struct list_head), local_flags);
2601 if (!slabp)
2602 return NULL;
2603 } else {
2604 slabp = objp + colour_off;
2605 colour_off += cachep->slab_size;
2607 slabp->inuse = 0;
2608 slabp->colouroff = colour_off;
2609 slabp->s_mem = objp + colour_off;
2610 slabp->nodeid = nodeid;
2611 slabp->free = 0;
2612 return slabp;
2615 static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
2617 return (kmem_bufctl_t *) (slabp + 1);
2620 static void cache_init_objs(struct kmem_cache *cachep,
2621 struct slab *slabp)
2623 int i;
2625 for (i = 0; i < cachep->num; i++) {
2626 void *objp = index_to_obj(cachep, slabp, i);
2627 #if DEBUG
2628 /* need to poison the objs? */
2629 if (cachep->flags & SLAB_POISON)
2630 poison_obj(cachep, objp, POISON_FREE);
2631 if (cachep->flags & SLAB_STORE_USER)
2632 *dbg_userword(cachep, objp) = NULL;
2634 if (cachep->flags & SLAB_RED_ZONE) {
2635 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2636 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2639 * Constructors are not allowed to allocate memory from the same
2640 * cache which they are a constructor for. Otherwise, deadlock.
2641 * They must also be threaded.
2643 if (cachep->ctor && !(cachep->flags & SLAB_POISON))
2644 cachep->ctor(objp + obj_offset(cachep));
2646 if (cachep->flags & SLAB_RED_ZONE) {
2647 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
2648 slab_error(cachep, "constructor overwrote the"
2649 " end of an object");
2650 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
2651 slab_error(cachep, "constructor overwrote the"
2652 " start of an object");
2654 if ((cachep->buffer_size % PAGE_SIZE) == 0 &&
2655 OFF_SLAB(cachep) && cachep->flags & SLAB_POISON)
2656 kernel_map_pages(virt_to_page(objp),
2657 cachep->buffer_size / PAGE_SIZE, 0);
2658 #else
2659 if (cachep->ctor)
2660 cachep->ctor(objp);
2661 #endif
2662 slab_bufctl(slabp)[i] = i + 1;
2664 slab_bufctl(slabp)[i - 1] = BUFCTL_END;
2667 static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
2669 if (CONFIG_ZONE_DMA_FLAG) {
2670 if (flags & GFP_DMA)
2671 BUG_ON(!(cachep->gfpflags & GFP_DMA));
2672 else
2673 BUG_ON(cachep->gfpflags & GFP_DMA);
2677 static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
2678 int nodeid)
2680 void *objp = index_to_obj(cachep, slabp, slabp->free);
2681 kmem_bufctl_t next;
2683 slabp->inuse++;
2684 next = slab_bufctl(slabp)[slabp->free];
2685 #if DEBUG
2686 slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
2687 WARN_ON(slabp->nodeid != nodeid);
2688 #endif
2689 slabp->free = next;
2691 return objp;
2694 static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
2695 void *objp, int nodeid)
2697 unsigned int objnr = obj_to_index(cachep, slabp, objp);
2699 #if DEBUG
2700 /* Verify that the slab belongs to the intended node */
2701 WARN_ON(slabp->nodeid != nodeid);
2703 if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
2704 printk(KERN_ERR "slab: double free detected in cache "
2705 "'%s', objp %p\n", cachep->name, objp);
2706 BUG();
2708 #endif
2709 slab_bufctl(slabp)[objnr] = slabp->free;
2710 slabp->free = objnr;
2711 slabp->inuse--;
2715 * Map pages beginning at addr to the given cache and slab. This is required
2716 * for the slab allocator to be able to lookup the cache and slab of a
2717 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
2719 static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
2720 void *addr)
2722 int nr_pages;
2723 struct page *page;
2725 page = virt_to_page(addr);
2727 nr_pages = 1;
2728 if (likely(!PageCompound(page)))
2729 nr_pages <<= cache->gfporder;
2731 do {
2732 page_set_cache(page, cache);
2733 page_set_slab(page, slab);
2734 page++;
2735 } while (--nr_pages);
2739 * Grow (by 1) the number of slabs within a cache. This is called by
2740 * kmem_cache_alloc() when there are no active objs left in a cache.
2742 static int cache_grow(struct kmem_cache *cachep,
2743 gfp_t flags, int nodeid, void *objp)
2745 struct slab *slabp;
2746 size_t offset;
2747 gfp_t local_flags;
2748 struct kmem_list3 *l3;
2751 * Be lazy and only check for valid flags here, keeping it out of the
2752 * critical path in kmem_cache_alloc().
2754 BUG_ON(flags & GFP_SLAB_BUG_MASK);
2755 local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
2757 /* Take the l3 list lock to change the colour_next on this node */
2758 check_irq_off();
2759 l3 = cachep->nodelists[nodeid];
2760 spin_lock(&l3->list_lock);
2762 /* Get colour for the slab, and cal the next value. */
2763 offset = l3->colour_next;
2764 l3->colour_next++;
2765 if (l3->colour_next >= cachep->colour)
2766 l3->colour_next = 0;
2767 spin_unlock(&l3->list_lock);
2769 offset *= cachep->colour_off;
2771 if (local_flags & __GFP_WAIT)
2772 local_irq_enable();
2775 * The test for missing atomic flag is performed here, rather than
2776 * the more obvious place, simply to reduce the critical path length
2777 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2778 * will eventually be caught here (where it matters).
2780 kmem_flagcheck(cachep, flags);
2783 * Get mem for the objs. Attempt to allocate a physical page from
2784 * 'nodeid'.
2786 if (!objp)
2787 objp = kmem_getpages(cachep, local_flags, nodeid);
2788 if (!objp)
2789 goto failed;
2791 /* Get slab management. */
2792 slabp = alloc_slabmgmt(cachep, objp, offset,
2793 local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
2794 if (!slabp)
2795 goto opps1;
2797 slab_map_pages(cachep, slabp, objp);
2799 cache_init_objs(cachep, slabp);
2801 if (local_flags & __GFP_WAIT)
2802 local_irq_disable();
2803 check_irq_off();
2804 spin_lock(&l3->list_lock);
2806 /* Make slab active. */
2807 list_add_tail(&slabp->list, &(l3->slabs_free));
2808 STATS_INC_GROWN(cachep);
2809 l3->free_objects += cachep->num;
2810 spin_unlock(&l3->list_lock);
2811 return 1;
2812 opps1:
2813 kmem_freepages(cachep, objp);
2814 failed:
2815 if (local_flags & __GFP_WAIT)
2816 local_irq_disable();
2817 return 0;
2820 #if DEBUG
2823 * Perform extra freeing checks:
2824 * - detect bad pointers.
2825 * - POISON/RED_ZONE checking
2827 static void kfree_debugcheck(const void *objp)
2829 if (!virt_addr_valid(objp)) {
2830 printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n",
2831 (unsigned long)objp);
2832 BUG();
2836 static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
2838 unsigned long long redzone1, redzone2;
2840 redzone1 = *dbg_redzone1(cache, obj);
2841 redzone2 = *dbg_redzone2(cache, obj);
2844 * Redzone is ok.
2846 if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
2847 return;
2849 if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
2850 slab_error(cache, "double free detected");
2851 else
2852 slab_error(cache, "memory outside object was overwritten");
2854 printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
2855 obj, redzone1, redzone2);
2858 static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
2859 void *caller)
2861 struct page *page;
2862 unsigned int objnr;
2863 struct slab *slabp;
2865 BUG_ON(virt_to_cache(objp) != cachep);
2867 objp -= obj_offset(cachep);
2868 kfree_debugcheck(objp);
2869 page = virt_to_head_page(objp);
2871 slabp = page_get_slab(page);
2873 if (cachep->flags & SLAB_RED_ZONE) {
2874 verify_redzone_free(cachep, objp);
2875 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2876 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2878 if (cachep->flags & SLAB_STORE_USER)
2879 *dbg_userword(cachep, objp) = caller;
2881 objnr = obj_to_index(cachep, slabp, objp);
2883 BUG_ON(objnr >= cachep->num);
2884 BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
2886 #ifdef CONFIG_DEBUG_SLAB_LEAK
2887 slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
2888 #endif
2889 if (cachep->flags & SLAB_POISON) {
2890 #ifdef CONFIG_DEBUG_PAGEALLOC
2891 if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
2892 store_stackinfo(cachep, objp, (unsigned long)caller);
2893 kernel_map_pages(virt_to_page(objp),
2894 cachep->buffer_size / PAGE_SIZE, 0);
2895 } else {
2896 poison_obj(cachep, objp, POISON_FREE);
2898 #else
2899 poison_obj(cachep, objp, POISON_FREE);
2900 #endif
2902 return objp;
2905 static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
2907 kmem_bufctl_t i;
2908 int entries = 0;
2910 /* Check slab's freelist to see if this obj is there. */
2911 for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
2912 entries++;
2913 if (entries > cachep->num || i >= cachep->num)
2914 goto bad;
2916 if (entries != cachep->num - slabp->inuse) {
2917 bad:
2918 printk(KERN_ERR "slab: Internal list corruption detected in "
2919 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2920 cachep->name, cachep->num, slabp, slabp->inuse);
2921 for (i = 0;
2922 i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t);
2923 i++) {
2924 if (i % 16 == 0)
2925 printk("\n%03x:", i);
2926 printk(" %02x", ((unsigned char *)slabp)[i]);
2928 printk("\n");
2929 BUG();
2932 #else
2933 #define kfree_debugcheck(x) do { } while(0)
2934 #define cache_free_debugcheck(x,objp,z) (objp)
2935 #define check_slabp(x,y) do { } while(0)
2936 #endif
2938 static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
2940 int batchcount;
2941 struct kmem_list3 *l3;
2942 struct array_cache *ac;
2943 int node;
2945 retry:
2946 check_irq_off();
2947 node = numa_node_id();
2948 ac = cpu_cache_get(cachep);
2949 batchcount = ac->batchcount;
2950 if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
2952 * If there was little recent activity on this cache, then
2953 * perform only a partial refill. Otherwise we could generate
2954 * refill bouncing.
2956 batchcount = BATCHREFILL_LIMIT;
2958 l3 = cachep->nodelists[node];
2960 BUG_ON(ac->avail > 0 || !l3);
2961 spin_lock(&l3->list_lock);
2963 /* See if we can refill from the shared array */
2964 if (l3->shared && transfer_objects(ac, l3->shared, batchcount))
2965 goto alloc_done;
2967 while (batchcount > 0) {
2968 struct list_head *entry;
2969 struct slab *slabp;
2970 /* Get slab alloc is to come from. */
2971 entry = l3->slabs_partial.next;
2972 if (entry == &l3->slabs_partial) {
2973 l3->free_touched = 1;
2974 entry = l3->slabs_free.next;
2975 if (entry == &l3->slabs_free)
2976 goto must_grow;
2979 slabp = list_entry(entry, struct slab, list);
2980 check_slabp(cachep, slabp);
2981 check_spinlock_acquired(cachep);
2984 * The slab was either on partial or free list so
2985 * there must be at least one object available for
2986 * allocation.
2988 BUG_ON(slabp->inuse >= cachep->num);
2990 while (slabp->inuse < cachep->num && batchcount--) {
2991 STATS_INC_ALLOCED(cachep);
2992 STATS_INC_ACTIVE(cachep);
2993 STATS_SET_HIGH(cachep);
2995 ac->entry[ac->avail++] = slab_get_obj(cachep, slabp,
2996 node);
2998 check_slabp(cachep, slabp);
3000 /* move slabp to correct slabp list: */
3001 list_del(&slabp->list);
3002 if (slabp->free == BUFCTL_END)
3003 list_add(&slabp->list, &l3->slabs_full);
3004 else
3005 list_add(&slabp->list, &l3->slabs_partial);
3008 must_grow:
3009 l3->free_objects -= ac->avail;
3010 alloc_done:
3011 spin_unlock(&l3->list_lock);
3013 if (unlikely(!ac->avail)) {
3014 int x;
3015 x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL);
3017 /* cache_grow can reenable interrupts, then ac could change. */
3018 ac = cpu_cache_get(cachep);
3019 if (!x && ac->avail == 0) /* no objects in sight? abort */
3020 return NULL;
3022 if (!ac->avail) /* objects refilled by interrupt? */
3023 goto retry;
3025 ac->touched = 1;
3026 return ac->entry[--ac->avail];
3029 static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
3030 gfp_t flags)
3032 might_sleep_if(flags & __GFP_WAIT);
3033 #if DEBUG
3034 kmem_flagcheck(cachep, flags);
3035 #endif
3038 #if DEBUG
3039 static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
3040 gfp_t flags, void *objp, void *caller)
3042 if (!objp)
3043 return objp;
3044 if (cachep->flags & SLAB_POISON) {
3045 #ifdef CONFIG_DEBUG_PAGEALLOC
3046 if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
3047 kernel_map_pages(virt_to_page(objp),
3048 cachep->buffer_size / PAGE_SIZE, 1);
3049 else
3050 check_poison_obj(cachep, objp);
3051 #else
3052 check_poison_obj(cachep, objp);
3053 #endif
3054 poison_obj(cachep, objp, POISON_INUSE);
3056 if (cachep->flags & SLAB_STORE_USER)
3057 *dbg_userword(cachep, objp) = caller;
3059 if (cachep->flags & SLAB_RED_ZONE) {
3060 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
3061 *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
3062 slab_error(cachep, "double free, or memory outside"
3063 " object was overwritten");
3064 printk(KERN_ERR
3065 "%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
3066 objp, *dbg_redzone1(cachep, objp),
3067 *dbg_redzone2(cachep, objp));
3069 *dbg_redzone1(cachep, objp) = RED_ACTIVE;
3070 *dbg_redzone2(cachep, objp) = RED_ACTIVE;
3072 #ifdef CONFIG_DEBUG_SLAB_LEAK
3074 struct slab *slabp;
3075 unsigned objnr;
3077 slabp = page_get_slab(virt_to_head_page(objp));
3078 objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
3079 slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
3081 #endif
3082 objp += obj_offset(cachep);
3083 if (cachep->ctor && cachep->flags & SLAB_POISON)
3084 cachep->ctor(objp);
3085 #if ARCH_SLAB_MINALIGN
3086 if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
3087 printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
3088 objp, ARCH_SLAB_MINALIGN);
3090 #endif
3091 return objp;
3093 #else
3094 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
3095 #endif
3097 static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags)
3099 if (cachep == &cache_cache)
3100 return false;
3102 return should_failslab(obj_size(cachep), flags);
3105 static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3107 void *objp;
3108 struct array_cache *ac;
3110 check_irq_off();
3112 ac = cpu_cache_get(cachep);
3113 if (likely(ac->avail)) {
3114 STATS_INC_ALLOCHIT(cachep);
3115 ac->touched = 1;
3116 objp = ac->entry[--ac->avail];
3117 } else {
3118 STATS_INC_ALLOCMISS(cachep);
3119 objp = cache_alloc_refill(cachep, flags);
3121 * the 'ac' may be updated by cache_alloc_refill(),
3122 * and kmemleak_erase() requires its correct value.
3124 ac = cpu_cache_get(cachep);
3127 * To avoid a false negative, if an object that is in one of the
3128 * per-CPU caches is leaked, we need to make sure kmemleak doesn't
3129 * treat the array pointers as a reference to the object.
3131 if (objp)
3132 kmemleak_erase(&ac->entry[ac->avail]);
3133 return objp;
3136 #ifdef CONFIG_NUMA
3138 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3140 * If we are in_interrupt, then process context, including cpusets and
3141 * mempolicy, may not apply and should not be used for allocation policy.
3143 static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
3145 int nid_alloc, nid_here;
3147 if (in_interrupt() || (flags & __GFP_THISNODE))
3148 return NULL;
3149 nid_alloc = nid_here = numa_node_id();
3150 if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
3151 nid_alloc = cpuset_mem_spread_node();
3152 else if (current->mempolicy)
3153 nid_alloc = slab_node(current->mempolicy);
3154 if (nid_alloc != nid_here)
3155 return ____cache_alloc_node(cachep, flags, nid_alloc);
3156 return NULL;
3160 * Fallback function if there was no memory available and no objects on a
3161 * certain node and fall back is permitted. First we scan all the
3162 * available nodelists for available objects. If that fails then we
3163 * perform an allocation without specifying a node. This allows the page
3164 * allocator to do its reclaim / fallback magic. We then insert the
3165 * slab into the proper nodelist and then allocate from it.
3167 static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3169 struct zonelist *zonelist;
3170 gfp_t local_flags;
3171 struct zoneref *z;
3172 struct zone *zone;
3173 enum zone_type high_zoneidx = gfp_zone(flags);
3174 void *obj = NULL;
3175 int nid;
3177 if (flags & __GFP_THISNODE)
3178 return NULL;
3180 zonelist = node_zonelist(slab_node(current->mempolicy), flags);
3181 local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
3183 retry:
3185 * Look through allowed nodes for objects available
3186 * from existing per node queues.
3188 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
3189 nid = zone_to_nid(zone);
3191 if (cpuset_zone_allowed_hardwall(zone, flags) &&
3192 cache->nodelists[nid] &&
3193 cache->nodelists[nid]->free_objects) {
3194 obj = ____cache_alloc_node(cache,
3195 flags | GFP_THISNODE, nid);
3196 if (obj)
3197 break;
3201 if (!obj) {
3203 * This allocation will be performed within the constraints
3204 * of the current cpuset / memory policy requirements.
3205 * We may trigger various forms of reclaim on the allowed
3206 * set and go into memory reserves if necessary.
3208 if (local_flags & __GFP_WAIT)
3209 local_irq_enable();
3210 kmem_flagcheck(cache, flags);
3211 obj = kmem_getpages(cache, local_flags, numa_node_id());
3212 if (local_flags & __GFP_WAIT)
3213 local_irq_disable();
3214 if (obj) {
3216 * Insert into the appropriate per node queues
3218 nid = page_to_nid(virt_to_page(obj));
3219 if (cache_grow(cache, flags, nid, obj)) {
3220 obj = ____cache_alloc_node(cache,
3221 flags | GFP_THISNODE, nid);
3222 if (!obj)
3224 * Another processor may allocate the
3225 * objects in the slab since we are
3226 * not holding any locks.
3228 goto retry;
3229 } else {
3230 /* cache_grow already freed obj */
3231 obj = NULL;
3235 return obj;
3239 * A interface to enable slab creation on nodeid
3241 static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
3242 int nodeid)
3244 struct list_head *entry;
3245 struct slab *slabp;
3246 struct kmem_list3 *l3;
3247 void *obj;
3248 int x;
3250 l3 = cachep->nodelists[nodeid];
3251 BUG_ON(!l3);
3253 retry:
3254 check_irq_off();
3255 spin_lock(&l3->list_lock);
3256 entry = l3->slabs_partial.next;
3257 if (entry == &l3->slabs_partial) {
3258 l3->free_touched = 1;
3259 entry = l3->slabs_free.next;
3260 if (entry == &l3->slabs_free)
3261 goto must_grow;
3264 slabp = list_entry(entry, struct slab, list);
3265 check_spinlock_acquired_node(cachep, nodeid);
3266 check_slabp(cachep, slabp);
3268 STATS_INC_NODEALLOCS(cachep);
3269 STATS_INC_ACTIVE(cachep);
3270 STATS_SET_HIGH(cachep);
3272 BUG_ON(slabp->inuse == cachep->num);
3274 obj = slab_get_obj(cachep, slabp, nodeid);
3275 check_slabp(cachep, slabp);
3276 l3->free_objects--;
3277 /* move slabp to correct slabp list: */
3278 list_del(&slabp->list);
3280 if (slabp->free == BUFCTL_END)
3281 list_add(&slabp->list, &l3->slabs_full);
3282 else
3283 list_add(&slabp->list, &l3->slabs_partial);
3285 spin_unlock(&l3->list_lock);
3286 goto done;
3288 must_grow:
3289 spin_unlock(&l3->list_lock);
3290 x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL);
3291 if (x)
3292 goto retry;
3294 return fallback_alloc(cachep, flags);
3296 done:
3297 return obj;
3301 * kmem_cache_alloc_node - Allocate an object on the specified node
3302 * @cachep: The cache to allocate from.
3303 * @flags: See kmalloc().
3304 * @nodeid: node number of the target node.
3305 * @caller: return address of caller, used for debug information
3307 * Identical to kmem_cache_alloc but it will allocate memory on the given
3308 * node, which can improve the performance for cpu bound structures.
3310 * Fallback to other node is possible if __GFP_THISNODE is not set.
3312 static __always_inline void *
3313 __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
3314 void *caller)
3316 unsigned long save_flags;
3317 void *ptr;
3319 flags &= gfp_allowed_mask;
3321 lockdep_trace_alloc(flags);
3323 if (slab_should_failslab(cachep, flags))
3324 return NULL;
3326 cache_alloc_debugcheck_before(cachep, flags);
3327 local_irq_save(save_flags);
3329 if (nodeid == -1)
3330 nodeid = numa_node_id();
3332 if (unlikely(!cachep->nodelists[nodeid])) {
3333 /* Node not bootstrapped yet */
3334 ptr = fallback_alloc(cachep, flags);
3335 goto out;
3338 if (nodeid == numa_node_id()) {
3340 * Use the locally cached objects if possible.
3341 * However ____cache_alloc does not allow fallback
3342 * to other nodes. It may fail while we still have
3343 * objects on other nodes available.
3345 ptr = ____cache_alloc(cachep, flags);
3346 if (ptr)
3347 goto out;
3349 /* ___cache_alloc_node can fall back to other nodes */
3350 ptr = ____cache_alloc_node(cachep, flags, nodeid);
3351 out:
3352 local_irq_restore(save_flags);
3353 ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
3354 kmemleak_alloc_recursive(ptr, obj_size(cachep), 1, cachep->flags,
3355 flags);
3357 if (likely(ptr))
3358 kmemcheck_slab_alloc(cachep, flags, ptr, obj_size(cachep));
3360 if (unlikely((flags & __GFP_ZERO) && ptr))
3361 memset(ptr, 0, obj_size(cachep));
3363 return ptr;
3366 static __always_inline void *
3367 __do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
3369 void *objp;
3371 if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
3372 objp = alternate_node_alloc(cache, flags);
3373 if (objp)
3374 goto out;
3376 objp = ____cache_alloc(cache, flags);
3379 * We may just have run out of memory on the local node.
3380 * ____cache_alloc_node() knows how to locate memory on other nodes
3382 if (!objp)
3383 objp = ____cache_alloc_node(cache, flags, numa_node_id());
3385 out:
3386 return objp;
3388 #else
3390 static __always_inline void *
3391 __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3393 return ____cache_alloc(cachep, flags);
3396 #endif /* CONFIG_NUMA */
3398 static __always_inline void *
3399 __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
3401 unsigned long save_flags;
3402 void *objp;
3404 flags &= gfp_allowed_mask;
3406 lockdep_trace_alloc(flags);
3408 if (slab_should_failslab(cachep, flags))
3409 return NULL;
3411 cache_alloc_debugcheck_before(cachep, flags);
3412 local_irq_save(save_flags);
3413 objp = __do_cache_alloc(cachep, flags);
3414 local_irq_restore(save_flags);
3415 objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
3416 kmemleak_alloc_recursive(objp, obj_size(cachep), 1, cachep->flags,
3417 flags);
3418 prefetchw(objp);
3420 if (likely(objp))
3421 kmemcheck_slab_alloc(cachep, flags, objp, obj_size(cachep));
3423 if (unlikely((flags & __GFP_ZERO) && objp))
3424 memset(objp, 0, obj_size(cachep));
3426 return objp;
3430 * Caller needs to acquire correct kmem_list's list_lock
3432 static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
3433 int node)
3435 int i;
3436 struct kmem_list3 *l3;
3438 for (i = 0; i < nr_objects; i++) {
3439 void *objp = objpp[i];
3440 struct slab *slabp;
3442 slabp = virt_to_slab(objp);
3443 l3 = cachep->nodelists[node];
3444 list_del(&slabp->list);
3445 check_spinlock_acquired_node(cachep, node);
3446 check_slabp(cachep, slabp);
3447 slab_put_obj(cachep, slabp, objp, node);
3448 STATS_DEC_ACTIVE(cachep);
3449 l3->free_objects++;
3450 check_slabp(cachep, slabp);
3452 /* fixup slab chains */
3453 if (slabp->inuse == 0) {
3454 if (l3->free_objects > l3->free_limit) {
3455 l3->free_objects -= cachep->num;
3456 /* No need to drop any previously held
3457 * lock here, even if we have a off-slab slab
3458 * descriptor it is guaranteed to come from
3459 * a different cache, refer to comments before
3460 * alloc_slabmgmt.
3462 slab_destroy(cachep, slabp);
3463 } else {
3464 list_add(&slabp->list, &l3->slabs_free);
3466 } else {
3467 /* Unconditionally move a slab to the end of the
3468 * partial list on free - maximum time for the
3469 * other objects to be freed, too.
3471 list_add_tail(&slabp->list, &l3->slabs_partial);
3476 static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
3478 int batchcount;
3479 struct kmem_list3 *l3;
3480 int node = numa_node_id();
3482 batchcount = ac->batchcount;
3483 #if DEBUG
3484 BUG_ON(!batchcount || batchcount > ac->avail);
3485 #endif
3486 check_irq_off();
3487 l3 = cachep->nodelists[node];
3488 spin_lock(&l3->list_lock);
3489 if (l3->shared) {
3490 struct array_cache *shared_array = l3->shared;
3491 int max = shared_array->limit - shared_array->avail;
3492 if (max) {
3493 if (batchcount > max)
3494 batchcount = max;
3495 memcpy(&(shared_array->entry[shared_array->avail]),
3496 ac->entry, sizeof(void *) * batchcount);
3497 shared_array->avail += batchcount;
3498 goto free_done;
3502 free_block(cachep, ac->entry, batchcount, node);
3503 free_done:
3504 #if STATS
3506 int i = 0;
3507 struct list_head *p;
3509 p = l3->slabs_free.next;
3510 while (p != &(l3->slabs_free)) {
3511 struct slab *slabp;
3513 slabp = list_entry(p, struct slab, list);
3514 BUG_ON(slabp->inuse);
3516 i++;
3517 p = p->next;
3519 STATS_SET_FREEABLE(cachep, i);
3521 #endif
3522 spin_unlock(&l3->list_lock);
3523 ac->avail -= batchcount;
3524 memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
3528 * Release an obj back to its cache. If the obj has a constructed state, it must
3529 * be in this state _before_ it is released. Called with disabled ints.
3531 static inline void __cache_free(struct kmem_cache *cachep, void *objp)
3533 struct array_cache *ac = cpu_cache_get(cachep);
3535 check_irq_off();
3536 kmemleak_free_recursive(objp, cachep->flags);
3537 objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
3539 kmemcheck_slab_free(cachep, objp, obj_size(cachep));
3542 * Skip calling cache_free_alien() when the platform is not numa.
3543 * This will avoid cache misses that happen while accessing slabp (which
3544 * is per page memory reference) to get nodeid. Instead use a global
3545 * variable to skip the call, which is mostly likely to be present in
3546 * the cache.
3548 if (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
3549 return;
3551 if (likely(ac->avail < ac->limit)) {
3552 STATS_INC_FREEHIT(cachep);
3553 ac->entry[ac->avail++] = objp;
3554 return;
3555 } else {
3556 STATS_INC_FREEMISS(cachep);
3557 cache_flusharray(cachep, ac);
3558 ac->entry[ac->avail++] = objp;
3563 * kmem_cache_alloc - Allocate an object
3564 * @cachep: The cache to allocate from.
3565 * @flags: See kmalloc().
3567 * Allocate an object from this cache. The flags are only relevant
3568 * if the cache has no available objects.
3570 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3572 void *ret = __cache_alloc(cachep, flags, __builtin_return_address(0));
3574 trace_kmem_cache_alloc(_RET_IP_, ret,
3575 obj_size(cachep), cachep->buffer_size, flags);
3577 return ret;
3579 EXPORT_SYMBOL(kmem_cache_alloc);
3581 #ifdef CONFIG_TRACING
3582 void *kmem_cache_alloc_notrace(struct kmem_cache *cachep, gfp_t flags)
3584 return __cache_alloc(cachep, flags, __builtin_return_address(0));
3586 EXPORT_SYMBOL(kmem_cache_alloc_notrace);
3587 #endif
3590 * kmem_ptr_validate - check if an untrusted pointer might be a slab entry.
3591 * @cachep: the cache we're checking against
3592 * @ptr: pointer to validate
3594 * This verifies that the untrusted pointer looks sane;
3595 * it is _not_ a guarantee that the pointer is actually
3596 * part of the slab cache in question, but it at least
3597 * validates that the pointer can be dereferenced and
3598 * looks half-way sane.
3600 * Currently only used for dentry validation.
3602 int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr)
3604 unsigned long addr = (unsigned long)ptr;
3605 unsigned long min_addr = PAGE_OFFSET;
3606 unsigned long align_mask = BYTES_PER_WORD - 1;
3607 unsigned long size = cachep->buffer_size;
3608 struct page *page;
3610 if (unlikely(addr < min_addr))
3611 goto out;
3612 if (unlikely(addr > (unsigned long)high_memory - size))
3613 goto out;
3614 if (unlikely(addr & align_mask))
3615 goto out;
3616 if (unlikely(!kern_addr_valid(addr)))
3617 goto out;
3618 if (unlikely(!kern_addr_valid(addr + size - 1)))
3619 goto out;
3620 page = virt_to_page(ptr);
3621 if (unlikely(!PageSlab(page)))
3622 goto out;
3623 if (unlikely(page_get_cache(page) != cachep))
3624 goto out;
3625 return 1;
3626 out:
3627 return 0;
3630 #ifdef CONFIG_NUMA
3631 void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
3633 void *ret = __cache_alloc_node(cachep, flags, nodeid,
3634 __builtin_return_address(0));
3636 trace_kmem_cache_alloc_node(_RET_IP_, ret,
3637 obj_size(cachep), cachep->buffer_size,
3638 flags, nodeid);
3640 return ret;
3642 EXPORT_SYMBOL(kmem_cache_alloc_node);
3644 #ifdef CONFIG_TRACING
3645 void *kmem_cache_alloc_node_notrace(struct kmem_cache *cachep,
3646 gfp_t flags,
3647 int nodeid)
3649 return __cache_alloc_node(cachep, flags, nodeid,
3650 __builtin_return_address(0));
3652 EXPORT_SYMBOL(kmem_cache_alloc_node_notrace);
3653 #endif
3655 static __always_inline void *
3656 __do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller)
3658 struct kmem_cache *cachep;
3659 void *ret;
3661 cachep = kmem_find_general_cachep(size, flags);
3662 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3663 return cachep;
3664 ret = kmem_cache_alloc_node_notrace(cachep, flags, node);
3666 trace_kmalloc_node((unsigned long) caller, ret,
3667 size, cachep->buffer_size, flags, node);
3669 return ret;
3672 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING)
3673 void *__kmalloc_node(size_t size, gfp_t flags, int node)
3675 return __do_kmalloc_node(size, flags, node,
3676 __builtin_return_address(0));
3678 EXPORT_SYMBOL(__kmalloc_node);
3680 void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
3681 int node, unsigned long caller)
3683 return __do_kmalloc_node(size, flags, node, (void *)caller);
3685 EXPORT_SYMBOL(__kmalloc_node_track_caller);
3686 #else
3687 void *__kmalloc_node(size_t size, gfp_t flags, int node)
3689 return __do_kmalloc_node(size, flags, node, NULL);
3691 EXPORT_SYMBOL(__kmalloc_node);
3692 #endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */
3693 #endif /* CONFIG_NUMA */
3696 * __do_kmalloc - allocate memory
3697 * @size: how many bytes of memory are required.
3698 * @flags: the type of memory to allocate (see kmalloc).
3699 * @caller: function caller for debug tracking of the caller
3701 static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
3702 void *caller)
3704 struct kmem_cache *cachep;
3705 void *ret;
3707 /* If you want to save a few bytes .text space: replace
3708 * __ with kmem_.
3709 * Then kmalloc uses the uninlined functions instead of the inline
3710 * functions.
3712 cachep = __find_general_cachep(size, flags);
3713 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3714 return cachep;
3715 ret = __cache_alloc(cachep, flags, caller);
3717 trace_kmalloc((unsigned long) caller, ret,
3718 size, cachep->buffer_size, flags);
3720 return ret;
3724 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING)
3725 void *__kmalloc(size_t size, gfp_t flags)
3727 return __do_kmalloc(size, flags, __builtin_return_address(0));
3729 EXPORT_SYMBOL(__kmalloc);
3731 void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller)
3733 return __do_kmalloc(size, flags, (void *)caller);
3735 EXPORT_SYMBOL(__kmalloc_track_caller);
3737 #else
3738 void *__kmalloc(size_t size, gfp_t flags)
3740 return __do_kmalloc(size, flags, NULL);
3742 EXPORT_SYMBOL(__kmalloc);
3743 #endif
3746 * kmem_cache_free - Deallocate an object
3747 * @cachep: The cache the allocation was from.
3748 * @objp: The previously allocated object.
3750 * Free an object which was previously allocated from this
3751 * cache.
3753 void kmem_cache_free(struct kmem_cache *cachep, void *objp)
3755 unsigned long flags;
3757 local_irq_save(flags);
3758 debug_check_no_locks_freed(objp, obj_size(cachep));
3759 if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
3760 debug_check_no_obj_freed(objp, obj_size(cachep));
3761 __cache_free(cachep, objp);
3762 local_irq_restore(flags);
3764 trace_kmem_cache_free(_RET_IP_, objp);
3766 EXPORT_SYMBOL(kmem_cache_free);
3769 * kfree - free previously allocated memory
3770 * @objp: pointer returned by kmalloc.
3772 * If @objp is NULL, no operation is performed.
3774 * Don't free memory not originally allocated by kmalloc()
3775 * or you will run into trouble.
3777 void kfree(const void *objp)
3779 struct kmem_cache *c;
3780 unsigned long flags;
3782 trace_kfree(_RET_IP_, objp);
3784 if (unlikely(ZERO_OR_NULL_PTR(objp)))
3785 return;
3786 local_irq_save(flags);
3787 kfree_debugcheck(objp);
3788 c = virt_to_cache(objp);
3789 debug_check_no_locks_freed(objp, obj_size(c));
3790 debug_check_no_obj_freed(objp, obj_size(c));
3791 __cache_free(c, (void *)objp);
3792 local_irq_restore(flags);
3794 EXPORT_SYMBOL(kfree);
3796 unsigned int kmem_cache_size(struct kmem_cache *cachep)
3798 return obj_size(cachep);
3800 EXPORT_SYMBOL(kmem_cache_size);
3802 const char *kmem_cache_name(struct kmem_cache *cachep)
3804 return cachep->name;
3806 EXPORT_SYMBOL_GPL(kmem_cache_name);
3809 * This initializes kmem_list3 or resizes various caches for all nodes.
3811 static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp)
3813 int node;
3814 struct kmem_list3 *l3;
3815 struct array_cache *new_shared;
3816 struct array_cache **new_alien = NULL;
3818 for_each_online_node(node) {
3820 if (use_alien_caches) {
3821 new_alien = alloc_alien_cache(node, cachep->limit, gfp);
3822 if (!new_alien)
3823 goto fail;
3826 new_shared = NULL;
3827 if (cachep->shared) {
3828 new_shared = alloc_arraycache(node,
3829 cachep->shared*cachep->batchcount,
3830 0xbaadf00d, gfp);
3831 if (!new_shared) {
3832 free_alien_cache(new_alien);
3833 goto fail;
3837 l3 = cachep->nodelists[node];
3838 if (l3) {
3839 struct array_cache *shared = l3->shared;
3841 spin_lock_irq(&l3->list_lock);
3843 if (shared)
3844 free_block(cachep, shared->entry,
3845 shared->avail, node);
3847 l3->shared = new_shared;
3848 if (!l3->alien) {
3849 l3->alien = new_alien;
3850 new_alien = NULL;
3852 l3->free_limit = (1 + nr_cpus_node(node)) *
3853 cachep->batchcount + cachep->num;
3854 spin_unlock_irq(&l3->list_lock);
3855 kfree(shared);
3856 free_alien_cache(new_alien);
3857 continue;
3859 l3 = kmalloc_node(sizeof(struct kmem_list3), gfp, node);
3860 if (!l3) {
3861 free_alien_cache(new_alien);
3862 kfree(new_shared);
3863 goto fail;
3866 kmem_list3_init(l3);
3867 l3->next_reap = jiffies + REAPTIMEOUT_LIST3 +
3868 ((unsigned long)cachep) % REAPTIMEOUT_LIST3;
3869 l3->shared = new_shared;
3870 l3->alien = new_alien;
3871 l3->free_limit = (1 + nr_cpus_node(node)) *
3872 cachep->batchcount + cachep->num;
3873 cachep->nodelists[node] = l3;
3875 return 0;
3877 fail:
3878 if (!cachep->next.next) {
3879 /* Cache is not active yet. Roll back what we did */
3880 node--;
3881 while (node >= 0) {
3882 if (cachep->nodelists[node]) {
3883 l3 = cachep->nodelists[node];
3885 kfree(l3->shared);
3886 free_alien_cache(l3->alien);
3887 kfree(l3);
3888 cachep->nodelists[node] = NULL;
3890 node--;
3893 return -ENOMEM;
3896 struct ccupdate_struct {
3897 struct kmem_cache *cachep;
3898 struct array_cache *new[NR_CPUS];
3901 static void do_ccupdate_local(void *info)
3903 struct ccupdate_struct *new = info;
3904 struct array_cache *old;
3906 check_irq_off();
3907 old = cpu_cache_get(new->cachep);
3909 new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()];
3910 new->new[smp_processor_id()] = old;
3913 /* Always called with the cache_chain_mutex held */
3914 static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
3915 int batchcount, int shared, gfp_t gfp)
3917 struct ccupdate_struct *new;
3918 int i;
3920 new = kzalloc(sizeof(*new), gfp);
3921 if (!new)
3922 return -ENOMEM;
3924 for_each_online_cpu(i) {
3925 new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
3926 batchcount, gfp);
3927 if (!new->new[i]) {
3928 for (i--; i >= 0; i--)
3929 kfree(new->new[i]);
3930 kfree(new);
3931 return -ENOMEM;
3934 new->cachep = cachep;
3936 on_each_cpu(do_ccupdate_local, (void *)new, 1);
3938 check_irq_on();
3939 cachep->batchcount = batchcount;
3940 cachep->limit = limit;
3941 cachep->shared = shared;
3943 for_each_online_cpu(i) {
3944 struct array_cache *ccold = new->new[i];
3945 if (!ccold)
3946 continue;
3947 spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3948 free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i));
3949 spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
3950 kfree(ccold);
3952 kfree(new);
3953 return alloc_kmemlist(cachep, gfp);
3956 /* Called with cache_chain_mutex held always */
3957 static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
3959 int err;
3960 int limit, shared;
3963 * The head array serves three purposes:
3964 * - create a LIFO ordering, i.e. return objects that are cache-warm
3965 * - reduce the number of spinlock operations.
3966 * - reduce the number of linked list operations on the slab and
3967 * bufctl chains: array operations are cheaper.
3968 * The numbers are guessed, we should auto-tune as described by
3969 * Bonwick.
3971 if (cachep->buffer_size > 131072)
3972 limit = 1;
3973 else if (cachep->buffer_size > PAGE_SIZE)
3974 limit = 8;
3975 else if (cachep->buffer_size > 1024)
3976 limit = 24;
3977 else if (cachep->buffer_size > 256)
3978 limit = 54;
3979 else
3980 limit = 120;
3983 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3984 * allocation behaviour: Most allocs on one cpu, most free operations
3985 * on another cpu. For these cases, an efficient object passing between
3986 * cpus is necessary. This is provided by a shared array. The array
3987 * replaces Bonwick's magazine layer.
3988 * On uniprocessor, it's functionally equivalent (but less efficient)
3989 * to a larger limit. Thus disabled by default.
3991 shared = 0;
3992 if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1)
3993 shared = 8;
3995 #if DEBUG
3997 * With debugging enabled, large batchcount lead to excessively long
3998 * periods with disabled local interrupts. Limit the batchcount
4000 if (limit > 32)
4001 limit = 32;
4002 #endif
4003 err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared, gfp);
4004 if (err)
4005 printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n",
4006 cachep->name, -err);
4007 return err;
4011 * Drain an array if it contains any elements taking the l3 lock only if
4012 * necessary. Note that the l3 listlock also protects the array_cache
4013 * if drain_array() is used on the shared array.
4015 void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3,
4016 struct array_cache *ac, int force, int node)
4018 int tofree;
4020 if (!ac || !ac->avail)
4021 return;
4022 if (ac->touched && !force) {
4023 ac->touched = 0;
4024 } else {
4025 spin_lock_irq(&l3->list_lock);
4026 if (ac->avail) {
4027 tofree = force ? ac->avail : (ac->limit + 4) / 5;
4028 if (tofree > ac->avail)
4029 tofree = (ac->avail + 1) / 2;
4030 free_block(cachep, ac->entry, tofree, node);
4031 ac->avail -= tofree;
4032 memmove(ac->entry, &(ac->entry[tofree]),
4033 sizeof(void *) * ac->avail);
4035 spin_unlock_irq(&l3->list_lock);
4040 * cache_reap - Reclaim memory from caches.
4041 * @w: work descriptor
4043 * Called from workqueue/eventd every few seconds.
4044 * Purpose:
4045 * - clear the per-cpu caches for this CPU.
4046 * - return freeable pages to the main free memory pool.
4048 * If we cannot acquire the cache chain mutex then just give up - we'll try
4049 * again on the next iteration.
4051 static void cache_reap(struct work_struct *w)
4053 struct kmem_cache *searchp;
4054 struct kmem_list3 *l3;
4055 int node = numa_node_id();
4056 struct delayed_work *work = to_delayed_work(w);
4058 if (!mutex_trylock(&cache_chain_mutex))
4059 /* Give up. Setup the next iteration. */
4060 goto out;
4062 list_for_each_entry(searchp, &cache_chain, next) {
4063 check_irq_on();
4066 * We only take the l3 lock if absolutely necessary and we
4067 * have established with reasonable certainty that
4068 * we can do some work if the lock was obtained.
4070 l3 = searchp->nodelists[node];
4072 reap_alien(searchp, l3);
4074 drain_array(searchp, l3, cpu_cache_get(searchp), 0, node);
4077 * These are racy checks but it does not matter
4078 * if we skip one check or scan twice.
4080 if (time_after(l3->next_reap, jiffies))
4081 goto next;
4083 l3->next_reap = jiffies + REAPTIMEOUT_LIST3;
4085 drain_array(searchp, l3, l3->shared, 0, node);
4087 if (l3->free_touched)
4088 l3->free_touched = 0;
4089 else {
4090 int freed;
4092 freed = drain_freelist(searchp, l3, (l3->free_limit +
4093 5 * searchp->num - 1) / (5 * searchp->num));
4094 STATS_ADD_REAPED(searchp, freed);
4096 next:
4097 cond_resched();
4099 check_irq_on();
4100 mutex_unlock(&cache_chain_mutex);
4101 next_reap_node();
4102 out:
4103 /* Set up the next iteration */
4104 schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC));
4107 #ifdef CONFIG_SLABINFO
4109 static void print_slabinfo_header(struct seq_file *m)
4112 * Output format version, so at least we can change it
4113 * without _too_ many complaints.
4115 #if STATS
4116 seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
4117 #else
4118 seq_puts(m, "slabinfo - version: 2.1\n");
4119 #endif
4120 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4121 "<objperslab> <pagesperslab>");
4122 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4123 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4124 #if STATS
4125 seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
4126 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
4127 seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
4128 #endif
4129 seq_putc(m, '\n');
4132 static void *s_start(struct seq_file *m, loff_t *pos)
4134 loff_t n = *pos;
4136 mutex_lock(&cache_chain_mutex);
4137 if (!n)
4138 print_slabinfo_header(m);
4140 return seq_list_start(&cache_chain, *pos);
4143 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4145 return seq_list_next(p, &cache_chain, pos);
4148 static void s_stop(struct seq_file *m, void *p)
4150 mutex_unlock(&cache_chain_mutex);
4153 static int s_show(struct seq_file *m, void *p)
4155 struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
4156 struct slab *slabp;
4157 unsigned long active_objs;
4158 unsigned long num_objs;
4159 unsigned long active_slabs = 0;
4160 unsigned long num_slabs, free_objects = 0, shared_avail = 0;
4161 const char *name;
4162 char *error = NULL;
4163 int node;
4164 struct kmem_list3 *l3;
4166 active_objs = 0;
4167 num_slabs = 0;
4168 for_each_online_node(node) {
4169 l3 = cachep->nodelists[node];
4170 if (!l3)
4171 continue;
4173 check_irq_on();
4174 spin_lock_irq(&l3->list_lock);
4176 list_for_each_entry(slabp, &l3->slabs_full, list) {
4177 if (slabp->inuse != cachep->num && !error)
4178 error = "slabs_full accounting error";
4179 active_objs += cachep->num;
4180 active_slabs++;
4182 list_for_each_entry(slabp, &l3->slabs_partial, list) {
4183 if (slabp->inuse == cachep->num && !error)
4184 error = "slabs_partial inuse accounting error";
4185 if (!slabp->inuse && !error)
4186 error = "slabs_partial/inuse accounting error";
4187 active_objs += slabp->inuse;
4188 active_slabs++;
4190 list_for_each_entry(slabp, &l3->slabs_free, list) {
4191 if (slabp->inuse && !error)
4192 error = "slabs_free/inuse accounting error";
4193 num_slabs++;
4195 free_objects += l3->free_objects;
4196 if (l3->shared)
4197 shared_avail += l3->shared->avail;
4199 spin_unlock_irq(&l3->list_lock);
4201 num_slabs += active_slabs;
4202 num_objs = num_slabs * cachep->num;
4203 if (num_objs - active_objs != free_objects && !error)
4204 error = "free_objects accounting error";
4206 name = cachep->name;
4207 if (error)
4208 printk(KERN_ERR "slab: cache %s error: %s\n", name, error);
4210 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
4211 name, active_objs, num_objs, cachep->buffer_size,
4212 cachep->num, (1 << cachep->gfporder));
4213 seq_printf(m, " : tunables %4u %4u %4u",
4214 cachep->limit, cachep->batchcount, cachep->shared);
4215 seq_printf(m, " : slabdata %6lu %6lu %6lu",
4216 active_slabs, num_slabs, shared_avail);
4217 #if STATS
4218 { /* list3 stats */
4219 unsigned long high = cachep->high_mark;
4220 unsigned long allocs = cachep->num_allocations;
4221 unsigned long grown = cachep->grown;
4222 unsigned long reaped = cachep->reaped;
4223 unsigned long errors = cachep->errors;
4224 unsigned long max_freeable = cachep->max_freeable;
4225 unsigned long node_allocs = cachep->node_allocs;
4226 unsigned long node_frees = cachep->node_frees;
4227 unsigned long overflows = cachep->node_overflow;
4229 seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
4230 %4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
4231 reaped, errors, max_freeable, node_allocs,
4232 node_frees, overflows);
4234 /* cpu stats */
4236 unsigned long allochit = atomic_read(&cachep->allochit);
4237 unsigned long allocmiss = atomic_read(&cachep->allocmiss);
4238 unsigned long freehit = atomic_read(&cachep->freehit);
4239 unsigned long freemiss = atomic_read(&cachep->freemiss);
4241 seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
4242 allochit, allocmiss, freehit, freemiss);
4244 #endif
4245 seq_putc(m, '\n');
4246 return 0;
4250 * slabinfo_op - iterator that generates /proc/slabinfo
4252 * Output layout:
4253 * cache-name
4254 * num-active-objs
4255 * total-objs
4256 * object size
4257 * num-active-slabs
4258 * total-slabs
4259 * num-pages-per-slab
4260 * + further values on SMP and with statistics enabled
4263 static const struct seq_operations slabinfo_op = {
4264 .start = s_start,
4265 .next = s_next,
4266 .stop = s_stop,
4267 .show = s_show,
4270 #define MAX_SLABINFO_WRITE 128
4272 * slabinfo_write - Tuning for the slab allocator
4273 * @file: unused
4274 * @buffer: user buffer
4275 * @count: data length
4276 * @ppos: unused
4278 ssize_t slabinfo_write(struct file *file, const char __user * buffer,
4279 size_t count, loff_t *ppos)
4281 char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
4282 int limit, batchcount, shared, res;
4283 struct kmem_cache *cachep;
4285 if (count > MAX_SLABINFO_WRITE)
4286 return -EINVAL;
4287 if (copy_from_user(&kbuf, buffer, count))
4288 return -EFAULT;
4289 kbuf[MAX_SLABINFO_WRITE] = '\0';
4291 tmp = strchr(kbuf, ' ');
4292 if (!tmp)
4293 return -EINVAL;
4294 *tmp = '\0';
4295 tmp++;
4296 if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
4297 return -EINVAL;
4299 /* Find the cache in the chain of caches. */
4300 mutex_lock(&cache_chain_mutex);
4301 res = -EINVAL;
4302 list_for_each_entry(cachep, &cache_chain, next) {
4303 if (!strcmp(cachep->name, kbuf)) {
4304 if (limit < 1 || batchcount < 1 ||
4305 batchcount > limit || shared < 0) {
4306 res = 0;
4307 } else {
4308 res = do_tune_cpucache(cachep, limit,
4309 batchcount, shared,
4310 GFP_KERNEL);
4312 break;
4315 mutex_unlock(&cache_chain_mutex);
4316 if (res >= 0)
4317 res = count;
4318 return res;
4321 static int slabinfo_open(struct inode *inode, struct file *file)
4323 return seq_open(file, &slabinfo_op);
4326 static const struct file_operations proc_slabinfo_operations = {
4327 .open = slabinfo_open,
4328 .read = seq_read,
4329 .write = slabinfo_write,
4330 .llseek = seq_lseek,
4331 .release = seq_release,
4334 #ifdef CONFIG_DEBUG_SLAB_LEAK
4336 static void *leaks_start(struct seq_file *m, loff_t *pos)
4338 mutex_lock(&cache_chain_mutex);
4339 return seq_list_start(&cache_chain, *pos);
4342 static inline int add_caller(unsigned long *n, unsigned long v)
4344 unsigned long *p;
4345 int l;
4346 if (!v)
4347 return 1;
4348 l = n[1];
4349 p = n + 2;
4350 while (l) {
4351 int i = l/2;
4352 unsigned long *q = p + 2 * i;
4353 if (*q == v) {
4354 q[1]++;
4355 return 1;
4357 if (*q > v) {
4358 l = i;
4359 } else {
4360 p = q + 2;
4361 l -= i + 1;
4364 if (++n[1] == n[0])
4365 return 0;
4366 memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
4367 p[0] = v;
4368 p[1] = 1;
4369 return 1;
4372 static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
4374 void *p;
4375 int i;
4376 if (n[0] == n[1])
4377 return;
4378 for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) {
4379 if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
4380 continue;
4381 if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
4382 return;
4386 static void show_symbol(struct seq_file *m, unsigned long address)
4388 #ifdef CONFIG_KALLSYMS
4389 unsigned long offset, size;
4390 char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN];
4392 if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
4393 seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
4394 if (modname[0])
4395 seq_printf(m, " [%s]", modname);
4396 return;
4398 #endif
4399 seq_printf(m, "%p", (void *)address);
4402 static int leaks_show(struct seq_file *m, void *p)
4404 struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next);
4405 struct slab *slabp;
4406 struct kmem_list3 *l3;
4407 const char *name;
4408 unsigned long *n = m->private;
4409 int node;
4410 int i;
4412 if (!(cachep->flags & SLAB_STORE_USER))
4413 return 0;
4414 if (!(cachep->flags & SLAB_RED_ZONE))
4415 return 0;
4417 /* OK, we can do it */
4419 n[1] = 0;
4421 for_each_online_node(node) {
4422 l3 = cachep->nodelists[node];
4423 if (!l3)
4424 continue;
4426 check_irq_on();
4427 spin_lock_irq(&l3->list_lock);
4429 list_for_each_entry(slabp, &l3->slabs_full, list)
4430 handle_slab(n, cachep, slabp);
4431 list_for_each_entry(slabp, &l3->slabs_partial, list)
4432 handle_slab(n, cachep, slabp);
4433 spin_unlock_irq(&l3->list_lock);
4435 name = cachep->name;
4436 if (n[0] == n[1]) {
4437 /* Increase the buffer size */
4438 mutex_unlock(&cache_chain_mutex);
4439 m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
4440 if (!m->private) {
4441 /* Too bad, we are really out */
4442 m->private = n;
4443 mutex_lock(&cache_chain_mutex);
4444 return -ENOMEM;
4446 *(unsigned long *)m->private = n[0] * 2;
4447 kfree(n);
4448 mutex_lock(&cache_chain_mutex);
4449 /* Now make sure this entry will be retried */
4450 m->count = m->size;
4451 return 0;
4453 for (i = 0; i < n[1]; i++) {
4454 seq_printf(m, "%s: %lu ", name, n[2*i+3]);
4455 show_symbol(m, n[2*i+2]);
4456 seq_putc(m, '\n');
4459 return 0;
4462 static const struct seq_operations slabstats_op = {
4463 .start = leaks_start,
4464 .next = s_next,
4465 .stop = s_stop,
4466 .show = leaks_show,
4469 static int slabstats_open(struct inode *inode, struct file *file)
4471 unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL);
4472 int ret = -ENOMEM;
4473 if (n) {
4474 ret = seq_open(file, &slabstats_op);
4475 if (!ret) {
4476 struct seq_file *m = file->private_data;
4477 *n = PAGE_SIZE / (2 * sizeof(unsigned long));
4478 m->private = n;
4479 n = NULL;
4481 kfree(n);
4483 return ret;
4486 static const struct file_operations proc_slabstats_operations = {
4487 .open = slabstats_open,
4488 .read = seq_read,
4489 .llseek = seq_lseek,
4490 .release = seq_release_private,
4492 #endif
4494 static int __init slab_proc_init(void)
4496 proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations);
4497 #ifdef CONFIG_DEBUG_SLAB_LEAK
4498 proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations);
4499 #endif
4500 return 0;
4502 module_init(slab_proc_init);
4503 #endif
4506 * ksize - get the actual amount of memory allocated for a given object
4507 * @objp: Pointer to the object
4509 * kmalloc may internally round up allocations and return more memory
4510 * than requested. ksize() can be used to determine the actual amount of
4511 * memory allocated. The caller may use this additional memory, even though
4512 * a smaller amount of memory was initially specified with the kmalloc call.
4513 * The caller must guarantee that objp points to a valid object previously
4514 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4515 * must not be freed during the duration of the call.
4517 size_t ksize(const void *objp)
4519 BUG_ON(!objp);
4520 if (unlikely(objp == ZERO_SIZE_PTR))
4521 return 0;
4523 return obj_size(virt_to_cache(objp));
4525 EXPORT_SYMBOL(ksize);