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 intializations to
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
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
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/config.h>
90 #include <linux/slab.h>
92 #include <linux/poison.h>
93 #include <linux/swap.h>
94 #include <linux/cache.h>
95 #include <linux/interrupt.h>
96 #include <linux/init.h>
97 #include <linux/compiler.h>
98 #include <linux/cpuset.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/rcupdate.h>
106 #include <linux/string.h>
107 #include <linux/nodemask.h>
108 #include <linux/mempolicy.h>
109 #include <linux/mutex.h>
110 #include <linux/rtmutex.h>
112 #include <asm/uaccess.h>
113 #include <asm/cacheflush.h>
114 #include <asm/tlbflush.h>
115 #include <asm/page.h>
118 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
119 * SLAB_RED_ZONE & SLAB_POISON.
120 * 0 for faster, smaller code (especially in the critical paths).
122 * STATS - 1 to collect stats for /proc/slabinfo.
123 * 0 for faster, smaller code (especially in the critical paths).
125 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
128 #ifdef CONFIG_DEBUG_SLAB
131 #define FORCED_DEBUG 1
135 #define FORCED_DEBUG 0
138 /* Shouldn't this be in a header file somewhere? */
139 #define BYTES_PER_WORD sizeof(void *)
141 #ifndef cache_line_size
142 #define cache_line_size() L1_CACHE_BYTES
145 #ifndef ARCH_KMALLOC_MINALIGN
147 * Enforce a minimum alignment for the kmalloc caches.
148 * Usually, the kmalloc caches are cache_line_size() aligned, except when
149 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
150 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
151 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
152 * Note that this flag disables some debug features.
154 #define ARCH_KMALLOC_MINALIGN 0
157 #ifndef ARCH_SLAB_MINALIGN
159 * Enforce a minimum alignment for all caches.
160 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
161 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
162 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
163 * some debug features.
165 #define ARCH_SLAB_MINALIGN 0
168 #ifndef ARCH_KMALLOC_FLAGS
169 #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
172 /* Legal flag mask for kmem_cache_create(). */
174 # define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
175 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
177 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
178 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
179 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
181 # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
182 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
183 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
184 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
190 * Bufctl's are used for linking objs within a slab
193 * This implementation relies on "struct page" for locating the cache &
194 * slab an object belongs to.
195 * This allows the bufctl structure to be small (one int), but limits
196 * the number of objects a slab (not a cache) can contain when off-slab
197 * bufctls are used. The limit is the size of the largest general cache
198 * that does not use off-slab slabs.
199 * For 32bit archs with 4 kB pages, is this 56.
200 * This is not serious, as it is only for large objects, when it is unwise
201 * to have too many per slab.
202 * Note: This limit can be raised by introducing a general cache whose size
203 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
206 typedef unsigned int kmem_bufctl_t
;
207 #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
208 #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
209 #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
210 #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
215 * Manages the objs in a slab. Placed either at the beginning of mem allocated
216 * for a slab, or allocated from an general cache.
217 * Slabs are chained into three list: fully used, partial, fully free slabs.
220 struct list_head list
;
221 unsigned long colouroff
;
222 void *s_mem
; /* including colour offset */
223 unsigned int inuse
; /* num of objs active in slab */
225 unsigned short nodeid
;
231 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
232 * arrange for kmem_freepages to be called via RCU. This is useful if
233 * we need to approach a kernel structure obliquely, from its address
234 * obtained without the usual locking. We can lock the structure to
235 * stabilize it and check it's still at the given address, only if we
236 * can be sure that the memory has not been meanwhile reused for some
237 * other kind of object (which our subsystem's lock might corrupt).
239 * rcu_read_lock before reading the address, then rcu_read_unlock after
240 * taking the spinlock within the structure expected at that address.
242 * We assume struct slab_rcu can overlay struct slab when destroying.
245 struct rcu_head head
;
246 struct kmem_cache
*cachep
;
254 * - LIFO ordering, to hand out cache-warm objects from _alloc
255 * - reduce the number of linked list operations
256 * - reduce spinlock operations
258 * The limit is stored in the per-cpu structure to reduce the data cache
265 unsigned int batchcount
;
266 unsigned int touched
;
269 * Must have this definition in here for the proper
270 * alignment of array_cache. Also simplifies accessing
272 * [0] is for gcc 2.95. It should really be [].
277 * bootstrap: The caches do not work without cpuarrays anymore, but the
278 * cpuarrays are allocated from the generic caches...
280 #define BOOT_CPUCACHE_ENTRIES 1
281 struct arraycache_init
{
282 struct array_cache cache
;
283 void *entries
[BOOT_CPUCACHE_ENTRIES
];
287 * The slab lists for all objects.
290 struct list_head slabs_partial
; /* partial list first, better asm code */
291 struct list_head slabs_full
;
292 struct list_head slabs_free
;
293 unsigned long free_objects
;
294 unsigned int free_limit
;
295 unsigned int colour_next
; /* Per-node cache coloring */
296 spinlock_t list_lock
;
297 struct array_cache
*shared
; /* shared per node */
298 struct array_cache
**alien
; /* on other nodes */
299 unsigned long next_reap
; /* updated without locking */
300 int free_touched
; /* updated without locking */
304 * Need this for bootstrapping a per node allocator.
306 #define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
307 struct kmem_list3 __initdata initkmem_list3
[NUM_INIT_LISTS
];
308 #define CACHE_CACHE 0
310 #define SIZE_L3 (1 + MAX_NUMNODES)
312 static int drain_freelist(struct kmem_cache
*cache
,
313 struct kmem_list3
*l3
, int tofree
);
314 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int len
,
316 static int enable_cpucache(struct kmem_cache
*cachep
);
317 static void cache_reap(void *unused
);
320 * This function must be completely optimized away if a constant is passed to
321 * it. Mostly the same as what is in linux/slab.h except it returns an index.
323 static __always_inline
int index_of(const size_t size
)
325 extern void __bad_size(void);
327 if (__builtin_constant_p(size
)) {
335 #include "linux/kmalloc_sizes.h"
343 static int slab_early_init
= 1;
345 #define INDEX_AC index_of(sizeof(struct arraycache_init))
346 #define INDEX_L3 index_of(sizeof(struct kmem_list3))
348 static void kmem_list3_init(struct kmem_list3
*parent
)
350 INIT_LIST_HEAD(&parent
->slabs_full
);
351 INIT_LIST_HEAD(&parent
->slabs_partial
);
352 INIT_LIST_HEAD(&parent
->slabs_free
);
353 parent
->shared
= NULL
;
354 parent
->alien
= NULL
;
355 parent
->colour_next
= 0;
356 spin_lock_init(&parent
->list_lock
);
357 parent
->free_objects
= 0;
358 parent
->free_touched
= 0;
361 #define MAKE_LIST(cachep, listp, slab, nodeid) \
363 INIT_LIST_HEAD(listp); \
364 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
367 #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
369 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
370 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
371 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
381 /* 1) per-cpu data, touched during every alloc/free */
382 struct array_cache
*array
[NR_CPUS
];
383 /* 2) Cache tunables. Protected by cache_chain_mutex */
384 unsigned int batchcount
;
388 unsigned int buffer_size
;
389 /* 3) touched by every alloc & free from the backend */
390 struct kmem_list3
*nodelists
[MAX_NUMNODES
];
392 unsigned int flags
; /* constant flags */
393 unsigned int num
; /* # of objs per slab */
395 /* 4) cache_grow/shrink */
396 /* order of pgs per slab (2^n) */
397 unsigned int gfporder
;
399 /* force GFP flags, e.g. GFP_DMA */
402 size_t colour
; /* cache colouring range */
403 unsigned int colour_off
; /* colour offset */
404 struct kmem_cache
*slabp_cache
;
405 unsigned int slab_size
;
406 unsigned int dflags
; /* dynamic flags */
408 /* constructor func */
409 void (*ctor
) (void *, struct kmem_cache
*, unsigned long);
411 /* de-constructor func */
412 void (*dtor
) (void *, struct kmem_cache
*, unsigned long);
414 /* 5) cache creation/removal */
416 struct list_head next
;
420 unsigned long num_active
;
421 unsigned long num_allocations
;
422 unsigned long high_mark
;
424 unsigned long reaped
;
425 unsigned long errors
;
426 unsigned long max_freeable
;
427 unsigned long node_allocs
;
428 unsigned long node_frees
;
429 unsigned long node_overflow
;
437 * If debugging is enabled, then the allocator can add additional
438 * fields and/or padding to every object. buffer_size contains the total
439 * object size including these internal fields, the following two
440 * variables contain the offset to the user object and its size.
447 #define CFLGS_OFF_SLAB (0x80000000UL)
448 #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
450 #define BATCHREFILL_LIMIT 16
452 * Optimization question: fewer reaps means less probability for unnessary
453 * cpucache drain/refill cycles.
455 * OTOH the cpuarrays can contain lots of objects,
456 * which could lock up otherwise freeable slabs.
458 #define REAPTIMEOUT_CPUC (2*HZ)
459 #define REAPTIMEOUT_LIST3 (4*HZ)
462 #define STATS_INC_ACTIVE(x) ((x)->num_active++)
463 #define STATS_DEC_ACTIVE(x) ((x)->num_active--)
464 #define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
465 #define STATS_INC_GROWN(x) ((x)->grown++)
466 #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
467 #define STATS_SET_HIGH(x) \
469 if ((x)->num_active > (x)->high_mark) \
470 (x)->high_mark = (x)->num_active; \
472 #define STATS_INC_ERR(x) ((x)->errors++)
473 #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
474 #define STATS_INC_NODEFREES(x) ((x)->node_frees++)
475 #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
476 #define STATS_SET_FREEABLE(x, i) \
478 if ((x)->max_freeable < i) \
479 (x)->max_freeable = i; \
481 #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
482 #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
483 #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
484 #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
486 #define STATS_INC_ACTIVE(x) do { } while (0)
487 #define STATS_DEC_ACTIVE(x) do { } while (0)
488 #define STATS_INC_ALLOCED(x) do { } while (0)
489 #define STATS_INC_GROWN(x) do { } while (0)
490 #define STATS_ADD_REAPED(x,y) do { } while (0)
491 #define STATS_SET_HIGH(x) do { } while (0)
492 #define STATS_INC_ERR(x) do { } while (0)
493 #define STATS_INC_NODEALLOCS(x) do { } while (0)
494 #define STATS_INC_NODEFREES(x) do { } while (0)
495 #define STATS_INC_ACOVERFLOW(x) do { } while (0)
496 #define STATS_SET_FREEABLE(x, i) do { } while (0)
497 #define STATS_INC_ALLOCHIT(x) do { } while (0)
498 #define STATS_INC_ALLOCMISS(x) do { } while (0)
499 #define STATS_INC_FREEHIT(x) do { } while (0)
500 #define STATS_INC_FREEMISS(x) do { } while (0)
506 * memory layout of objects:
508 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
509 * the end of an object is aligned with the end of the real
510 * allocation. Catches writes behind the end of the allocation.
511 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
513 * cachep->obj_offset: The real object.
514 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
515 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
516 * [BYTES_PER_WORD long]
518 static int obj_offset(struct kmem_cache
*cachep
)
520 return cachep
->obj_offset
;
523 static int obj_size(struct kmem_cache
*cachep
)
525 return cachep
->obj_size
;
528 static unsigned long *dbg_redzone1(struct kmem_cache
*cachep
, void *objp
)
530 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
531 return (unsigned long*) (objp
+obj_offset(cachep
)-BYTES_PER_WORD
);
534 static unsigned long *dbg_redzone2(struct kmem_cache
*cachep
, void *objp
)
536 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
537 if (cachep
->flags
& SLAB_STORE_USER
)
538 return (unsigned long *)(objp
+ cachep
->buffer_size
-
540 return (unsigned long *)(objp
+ cachep
->buffer_size
- BYTES_PER_WORD
);
543 static void **dbg_userword(struct kmem_cache
*cachep
, void *objp
)
545 BUG_ON(!(cachep
->flags
& SLAB_STORE_USER
));
546 return (void **)(objp
+ cachep
->buffer_size
- BYTES_PER_WORD
);
551 #define obj_offset(x) 0
552 #define obj_size(cachep) (cachep->buffer_size)
553 #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;})
554 #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;})
555 #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
560 * Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
563 #if defined(CONFIG_LARGE_ALLOCS)
564 #define MAX_OBJ_ORDER 13 /* up to 32Mb */
565 #define MAX_GFP_ORDER 13 /* up to 32Mb */
566 #elif defined(CONFIG_MMU)
567 #define MAX_OBJ_ORDER 5 /* 32 pages */
568 #define MAX_GFP_ORDER 5 /* 32 pages */
570 #define MAX_OBJ_ORDER 8 /* up to 1Mb */
571 #define MAX_GFP_ORDER 8 /* up to 1Mb */
575 * Do not go above this order unless 0 objects fit into the slab.
577 #define BREAK_GFP_ORDER_HI 1
578 #define BREAK_GFP_ORDER_LO 0
579 static int slab_break_gfp_order
= BREAK_GFP_ORDER_LO
;
582 * Functions for storing/retrieving the cachep and or slab from the page
583 * allocator. These are used to find the slab an obj belongs to. With kfree(),
584 * these are used to find the cache which an obj belongs to.
586 static inline void page_set_cache(struct page
*page
, struct kmem_cache
*cache
)
588 page
->lru
.next
= (struct list_head
*)cache
;
591 static inline struct kmem_cache
*page_get_cache(struct page
*page
)
593 if (unlikely(PageCompound(page
)))
594 page
= (struct page
*)page_private(page
);
595 BUG_ON(!PageSlab(page
));
596 return (struct kmem_cache
*)page
->lru
.next
;
599 static inline void page_set_slab(struct page
*page
, struct slab
*slab
)
601 page
->lru
.prev
= (struct list_head
*)slab
;
604 static inline struct slab
*page_get_slab(struct page
*page
)
606 if (unlikely(PageCompound(page
)))
607 page
= (struct page
*)page_private(page
);
608 BUG_ON(!PageSlab(page
));
609 return (struct slab
*)page
->lru
.prev
;
612 static inline struct kmem_cache
*virt_to_cache(const void *obj
)
614 struct page
*page
= virt_to_page(obj
);
615 return page_get_cache(page
);
618 static inline struct slab
*virt_to_slab(const void *obj
)
620 struct page
*page
= virt_to_page(obj
);
621 return page_get_slab(page
);
624 static inline void *index_to_obj(struct kmem_cache
*cache
, struct slab
*slab
,
627 return slab
->s_mem
+ cache
->buffer_size
* idx
;
630 static inline unsigned int obj_to_index(struct kmem_cache
*cache
,
631 struct slab
*slab
, void *obj
)
633 return (unsigned)(obj
- slab
->s_mem
) / cache
->buffer_size
;
637 * These are the default caches for kmalloc. Custom caches can have other sizes.
639 struct cache_sizes malloc_sizes
[] = {
640 #define CACHE(x) { .cs_size = (x) },
641 #include <linux/kmalloc_sizes.h>
645 EXPORT_SYMBOL(malloc_sizes
);
647 /* Must match cache_sizes above. Out of line to keep cache footprint low. */
653 static struct cache_names __initdata cache_names
[] = {
654 #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
655 #include <linux/kmalloc_sizes.h>
660 static struct arraycache_init initarray_cache __initdata
=
661 { {0, BOOT_CPUCACHE_ENTRIES
, 1, 0} };
662 static struct arraycache_init initarray_generic
=
663 { {0, BOOT_CPUCACHE_ENTRIES
, 1, 0} };
665 /* internal cache of cache description objs */
666 static struct kmem_cache cache_cache
= {
668 .limit
= BOOT_CPUCACHE_ENTRIES
,
670 .buffer_size
= sizeof(struct kmem_cache
),
671 .name
= "kmem_cache",
673 .obj_size
= sizeof(struct kmem_cache
),
677 #define BAD_ALIEN_MAGIC 0x01020304ul
679 #ifdef CONFIG_LOCKDEP
682 * Slab sometimes uses the kmalloc slabs to store the slab headers
683 * for other slabs "off slab".
684 * The locking for this is tricky in that it nests within the locks
685 * of all other slabs in a few places; to deal with this special
686 * locking we put on-slab caches into a separate lock-class.
688 * We set lock class for alien array caches which are up during init.
689 * The lock annotation will be lost if all cpus of a node goes down and
690 * then comes back up during hotplug
692 static struct lock_class_key on_slab_l3_key
;
693 static struct lock_class_key on_slab_alc_key
;
695 static inline void init_lock_keys(void)
699 struct cache_sizes
*s
= malloc_sizes
;
701 while (s
->cs_size
!= ULONG_MAX
) {
703 struct array_cache
**alc
;
705 struct kmem_list3
*l3
= s
->cs_cachep
->nodelists
[q
];
706 if (!l3
|| OFF_SLAB(s
->cs_cachep
))
708 lockdep_set_class(&l3
->list_lock
, &on_slab_l3_key
);
711 * FIXME: This check for BAD_ALIEN_MAGIC
712 * should go away when common slab code is taught to
713 * work even without alien caches.
714 * Currently, non NUMA code returns BAD_ALIEN_MAGIC
715 * for alloc_alien_cache,
717 if (!alc
|| (unsigned long)alc
== BAD_ALIEN_MAGIC
)
721 lockdep_set_class(&alc
[r
]->lock
,
729 static inline void init_lock_keys(void)
734 /* Guard access to the cache-chain. */
735 static DEFINE_MUTEX(cache_chain_mutex
);
736 static struct list_head cache_chain
;
739 * vm_enough_memory() looks at this to determine how many slab-allocated pages
740 * are possibly freeable under pressure
742 * SLAB_RECLAIM_ACCOUNT turns this on per-slab
744 atomic_t slab_reclaim_pages
;
747 * chicken and egg problem: delay the per-cpu array allocation
748 * until the general caches are up.
758 * used by boot code to determine if it can use slab based allocator
760 int slab_is_available(void)
762 return g_cpucache_up
== FULL
;
765 static DEFINE_PER_CPU(struct work_struct
, reap_work
);
767 static inline struct array_cache
*cpu_cache_get(struct kmem_cache
*cachep
)
769 return cachep
->array
[smp_processor_id()];
772 static inline struct kmem_cache
*__find_general_cachep(size_t size
,
775 struct cache_sizes
*csizep
= malloc_sizes
;
778 /* This happens if someone tries to call
779 * kmem_cache_create(), or __kmalloc(), before
780 * the generic caches are initialized.
782 BUG_ON(malloc_sizes
[INDEX_AC
].cs_cachep
== NULL
);
784 while (size
> csizep
->cs_size
)
788 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
789 * has cs_{dma,}cachep==NULL. Thus no special case
790 * for large kmalloc calls required.
792 if (unlikely(gfpflags
& GFP_DMA
))
793 return csizep
->cs_dmacachep
;
794 return csizep
->cs_cachep
;
797 static struct kmem_cache
*kmem_find_general_cachep(size_t size
, gfp_t gfpflags
)
799 return __find_general_cachep(size
, gfpflags
);
802 static size_t slab_mgmt_size(size_t nr_objs
, size_t align
)
804 return ALIGN(sizeof(struct slab
)+nr_objs
*sizeof(kmem_bufctl_t
), align
);
808 * Calculate the number of objects and left-over bytes for a given buffer size.
810 static void cache_estimate(unsigned long gfporder
, size_t buffer_size
,
811 size_t align
, int flags
, size_t *left_over
,
816 size_t slab_size
= PAGE_SIZE
<< gfporder
;
819 * The slab management structure can be either off the slab or
820 * on it. For the latter case, the memory allocated for a
824 * - One kmem_bufctl_t for each object
825 * - Padding to respect alignment of @align
826 * - @buffer_size bytes for each object
828 * If the slab management structure is off the slab, then the
829 * alignment will already be calculated into the size. Because
830 * the slabs are all pages aligned, the objects will be at the
831 * correct alignment when allocated.
833 if (flags
& CFLGS_OFF_SLAB
) {
835 nr_objs
= slab_size
/ buffer_size
;
837 if (nr_objs
> SLAB_LIMIT
)
838 nr_objs
= SLAB_LIMIT
;
841 * Ignore padding for the initial guess. The padding
842 * is at most @align-1 bytes, and @buffer_size is at
843 * least @align. In the worst case, this result will
844 * be one greater than the number of objects that fit
845 * into the memory allocation when taking the padding
848 nr_objs
= (slab_size
- sizeof(struct slab
)) /
849 (buffer_size
+ sizeof(kmem_bufctl_t
));
852 * This calculated number will be either the right
853 * amount, or one greater than what we want.
855 if (slab_mgmt_size(nr_objs
, align
) + nr_objs
*buffer_size
859 if (nr_objs
> SLAB_LIMIT
)
860 nr_objs
= SLAB_LIMIT
;
862 mgmt_size
= slab_mgmt_size(nr_objs
, align
);
865 *left_over
= slab_size
- nr_objs
*buffer_size
- mgmt_size
;
868 #define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
870 static void __slab_error(const char *function
, struct kmem_cache
*cachep
,
873 printk(KERN_ERR
"slab error in %s(): cache `%s': %s\n",
874 function
, cachep
->name
, msg
);
880 * Special reaping functions for NUMA systems called from cache_reap().
881 * These take care of doing round robin flushing of alien caches (containing
882 * objects freed on different nodes from which they were allocated) and the
883 * flushing of remote pcps by calling drain_node_pages.
885 static DEFINE_PER_CPU(unsigned long, reap_node
);
887 static void init_reap_node(int cpu
)
891 node
= next_node(cpu_to_node(cpu
), node_online_map
);
892 if (node
== MAX_NUMNODES
)
893 node
= first_node(node_online_map
);
895 __get_cpu_var(reap_node
) = node
;
898 static void next_reap_node(void)
900 int node
= __get_cpu_var(reap_node
);
903 * Also drain per cpu pages on remote zones
905 if (node
!= numa_node_id())
906 drain_node_pages(node
);
908 node
= next_node(node
, node_online_map
);
909 if (unlikely(node
>= MAX_NUMNODES
))
910 node
= first_node(node_online_map
);
911 __get_cpu_var(reap_node
) = node
;
915 #define init_reap_node(cpu) do { } while (0)
916 #define next_reap_node(void) do { } while (0)
920 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
921 * via the workqueue/eventd.
922 * Add the CPU number into the expiration time to minimize the possibility of
923 * the CPUs getting into lockstep and contending for the global cache chain
926 static void __devinit
start_cpu_timer(int cpu
)
928 struct work_struct
*reap_work
= &per_cpu(reap_work
, cpu
);
931 * When this gets called from do_initcalls via cpucache_init(),
932 * init_workqueues() has already run, so keventd will be setup
935 if (keventd_up() && reap_work
->func
== NULL
) {
937 INIT_WORK(reap_work
, cache_reap
, NULL
);
938 schedule_delayed_work_on(cpu
, reap_work
, HZ
+ 3 * cpu
);
942 static struct array_cache
*alloc_arraycache(int node
, int entries
,
945 int memsize
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
946 struct array_cache
*nc
= NULL
;
948 nc
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
952 nc
->batchcount
= batchcount
;
954 spin_lock_init(&nc
->lock
);
960 * Transfer objects in one arraycache to another.
961 * Locking must be handled by the caller.
963 * Return the number of entries transferred.
965 static int transfer_objects(struct array_cache
*to
,
966 struct array_cache
*from
, unsigned int max
)
968 /* Figure out how many entries to transfer */
969 int nr
= min(min(from
->avail
, max
), to
->limit
- to
->avail
);
974 memcpy(to
->entry
+ to
->avail
, from
->entry
+ from
->avail
-nr
,
984 static void *__cache_alloc_node(struct kmem_cache
*, gfp_t
, int);
985 static void *alternate_node_alloc(struct kmem_cache
*, gfp_t
);
987 static struct array_cache
**alloc_alien_cache(int node
, int limit
)
989 struct array_cache
**ac_ptr
;
990 int memsize
= sizeof(void *) * MAX_NUMNODES
;
995 ac_ptr
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
998 if (i
== node
|| !node_online(i
)) {
1002 ac_ptr
[i
] = alloc_arraycache(node
, limit
, 0xbaadf00d);
1004 for (i
--; i
<= 0; i
--)
1014 static void free_alien_cache(struct array_cache
**ac_ptr
)
1025 static void __drain_alien_cache(struct kmem_cache
*cachep
,
1026 struct array_cache
*ac
, int node
)
1028 struct kmem_list3
*rl3
= cachep
->nodelists
[node
];
1031 spin_lock(&rl3
->list_lock
);
1033 * Stuff objects into the remote nodes shared array first.
1034 * That way we could avoid the overhead of putting the objects
1035 * into the free lists and getting them back later.
1038 transfer_objects(rl3
->shared
, ac
, ac
->limit
);
1040 free_block(cachep
, ac
->entry
, ac
->avail
, node
);
1042 spin_unlock(&rl3
->list_lock
);
1047 * Called from cache_reap() to regularly drain alien caches round robin.
1049 static void reap_alien(struct kmem_cache
*cachep
, struct kmem_list3
*l3
)
1051 int node
= __get_cpu_var(reap_node
);
1054 struct array_cache
*ac
= l3
->alien
[node
];
1056 if (ac
&& ac
->avail
&& spin_trylock_irq(&ac
->lock
)) {
1057 __drain_alien_cache(cachep
, ac
, node
);
1058 spin_unlock_irq(&ac
->lock
);
1063 static void drain_alien_cache(struct kmem_cache
*cachep
,
1064 struct array_cache
**alien
)
1067 struct array_cache
*ac
;
1068 unsigned long flags
;
1070 for_each_online_node(i
) {
1073 spin_lock_irqsave(&ac
->lock
, flags
);
1074 __drain_alien_cache(cachep
, ac
, i
);
1075 spin_unlock_irqrestore(&ac
->lock
, flags
);
1080 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
1082 struct slab
*slabp
= virt_to_slab(objp
);
1083 int nodeid
= slabp
->nodeid
;
1084 struct kmem_list3
*l3
;
1085 struct array_cache
*alien
= NULL
;
1088 * Make sure we are not freeing a object from another node to the array
1089 * cache on this cpu.
1091 if (likely(slabp
->nodeid
== numa_node_id()))
1094 l3
= cachep
->nodelists
[numa_node_id()];
1095 STATS_INC_NODEFREES(cachep
);
1096 if (l3
->alien
&& l3
->alien
[nodeid
]) {
1097 alien
= l3
->alien
[nodeid
];
1098 spin_lock(&alien
->lock
);
1099 if (unlikely(alien
->avail
== alien
->limit
)) {
1100 STATS_INC_ACOVERFLOW(cachep
);
1101 __drain_alien_cache(cachep
, alien
, nodeid
);
1103 alien
->entry
[alien
->avail
++] = objp
;
1104 spin_unlock(&alien
->lock
);
1106 spin_lock(&(cachep
->nodelists
[nodeid
])->list_lock
);
1107 free_block(cachep
, &objp
, 1, nodeid
);
1108 spin_unlock(&(cachep
->nodelists
[nodeid
])->list_lock
);
1115 #define drain_alien_cache(cachep, alien) do { } while (0)
1116 #define reap_alien(cachep, l3) do { } while (0)
1118 static inline struct array_cache
**alloc_alien_cache(int node
, int limit
)
1120 return (struct array_cache
**)BAD_ALIEN_MAGIC
;
1123 static inline void free_alien_cache(struct array_cache
**ac_ptr
)
1127 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
1134 static int __cpuinit
cpuup_callback(struct notifier_block
*nfb
,
1135 unsigned long action
, void *hcpu
)
1137 long cpu
= (long)hcpu
;
1138 struct kmem_cache
*cachep
;
1139 struct kmem_list3
*l3
= NULL
;
1140 int node
= cpu_to_node(cpu
);
1141 int memsize
= sizeof(struct kmem_list3
);
1144 case CPU_UP_PREPARE
:
1145 mutex_lock(&cache_chain_mutex
);
1147 * We need to do this right in the beginning since
1148 * alloc_arraycache's are going to use this list.
1149 * kmalloc_node allows us to add the slab to the right
1150 * kmem_list3 and not this cpu's kmem_list3
1153 list_for_each_entry(cachep
, &cache_chain
, next
) {
1155 * Set up the size64 kmemlist for cpu before we can
1156 * begin anything. Make sure some other cpu on this
1157 * node has not already allocated this
1159 if (!cachep
->nodelists
[node
]) {
1160 l3
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
1163 kmem_list3_init(l3
);
1164 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
+
1165 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1168 * The l3s don't come and go as CPUs come and
1169 * go. cache_chain_mutex is sufficient
1172 cachep
->nodelists
[node
] = l3
;
1175 spin_lock_irq(&cachep
->nodelists
[node
]->list_lock
);
1176 cachep
->nodelists
[node
]->free_limit
=
1177 (1 + nr_cpus_node(node
)) *
1178 cachep
->batchcount
+ cachep
->num
;
1179 spin_unlock_irq(&cachep
->nodelists
[node
]->list_lock
);
1183 * Now we can go ahead with allocating the shared arrays and
1186 list_for_each_entry(cachep
, &cache_chain
, next
) {
1187 struct array_cache
*nc
;
1188 struct array_cache
*shared
;
1189 struct array_cache
**alien
;
1191 nc
= alloc_arraycache(node
, cachep
->limit
,
1192 cachep
->batchcount
);
1195 shared
= alloc_arraycache(node
,
1196 cachep
->shared
* cachep
->batchcount
,
1201 alien
= alloc_alien_cache(node
, cachep
->limit
);
1204 cachep
->array
[cpu
] = nc
;
1205 l3
= cachep
->nodelists
[node
];
1208 spin_lock_irq(&l3
->list_lock
);
1211 * We are serialised from CPU_DEAD or
1212 * CPU_UP_CANCELLED by the cpucontrol lock
1214 l3
->shared
= shared
;
1223 spin_unlock_irq(&l3
->list_lock
);
1225 free_alien_cache(alien
);
1227 mutex_unlock(&cache_chain_mutex
);
1230 start_cpu_timer(cpu
);
1232 #ifdef CONFIG_HOTPLUG_CPU
1235 * Even if all the cpus of a node are down, we don't free the
1236 * kmem_list3 of any cache. This to avoid a race between
1237 * cpu_down, and a kmalloc allocation from another cpu for
1238 * memory from the node of the cpu going down. The list3
1239 * structure is usually allocated from kmem_cache_create() and
1240 * gets destroyed at kmem_cache_destroy().
1243 case CPU_UP_CANCELED
:
1244 mutex_lock(&cache_chain_mutex
);
1245 list_for_each_entry(cachep
, &cache_chain
, next
) {
1246 struct array_cache
*nc
;
1247 struct array_cache
*shared
;
1248 struct array_cache
**alien
;
1251 mask
= node_to_cpumask(node
);
1252 /* cpu is dead; no one can alloc from it. */
1253 nc
= cachep
->array
[cpu
];
1254 cachep
->array
[cpu
] = NULL
;
1255 l3
= cachep
->nodelists
[node
];
1258 goto free_array_cache
;
1260 spin_lock_irq(&l3
->list_lock
);
1262 /* Free limit for this kmem_list3 */
1263 l3
->free_limit
-= cachep
->batchcount
;
1265 free_block(cachep
, nc
->entry
, nc
->avail
, node
);
1267 if (!cpus_empty(mask
)) {
1268 spin_unlock_irq(&l3
->list_lock
);
1269 goto free_array_cache
;
1272 shared
= l3
->shared
;
1274 free_block(cachep
, l3
->shared
->entry
,
1275 l3
->shared
->avail
, node
);
1282 spin_unlock_irq(&l3
->list_lock
);
1286 drain_alien_cache(cachep
, alien
);
1287 free_alien_cache(alien
);
1293 * In the previous loop, all the objects were freed to
1294 * the respective cache's slabs, now we can go ahead and
1295 * shrink each nodelist to its limit.
1297 list_for_each_entry(cachep
, &cache_chain
, next
) {
1298 l3
= cachep
->nodelists
[node
];
1301 drain_freelist(cachep
, l3
, l3
->free_objects
);
1303 mutex_unlock(&cache_chain_mutex
);
1309 mutex_unlock(&cache_chain_mutex
);
1313 static struct notifier_block __cpuinitdata cpucache_notifier
= {
1314 &cpuup_callback
, NULL
, 0
1318 * swap the static kmem_list3 with kmalloced memory
1320 static void init_list(struct kmem_cache
*cachep
, struct kmem_list3
*list
,
1323 struct kmem_list3
*ptr
;
1325 BUG_ON(cachep
->nodelists
[nodeid
] != list
);
1326 ptr
= kmalloc_node(sizeof(struct kmem_list3
), GFP_KERNEL
, nodeid
);
1329 local_irq_disable();
1330 memcpy(ptr
, list
, sizeof(struct kmem_list3
));
1332 * Do not assume that spinlocks can be initialized via memcpy:
1334 spin_lock_init(&ptr
->list_lock
);
1336 MAKE_ALL_LISTS(cachep
, ptr
, nodeid
);
1337 cachep
->nodelists
[nodeid
] = ptr
;
1342 * Initialisation. Called after the page allocator have been initialised and
1343 * before smp_init().
1345 void __init
kmem_cache_init(void)
1348 struct cache_sizes
*sizes
;
1349 struct cache_names
*names
;
1353 for (i
= 0; i
< NUM_INIT_LISTS
; i
++) {
1354 kmem_list3_init(&initkmem_list3
[i
]);
1355 if (i
< MAX_NUMNODES
)
1356 cache_cache
.nodelists
[i
] = NULL
;
1360 * Fragmentation resistance on low memory - only use bigger
1361 * page orders on machines with more than 32MB of memory.
1363 if (num_physpages
> (32 << 20) >> PAGE_SHIFT
)
1364 slab_break_gfp_order
= BREAK_GFP_ORDER_HI
;
1366 /* Bootstrap is tricky, because several objects are allocated
1367 * from caches that do not exist yet:
1368 * 1) initialize the cache_cache cache: it contains the struct
1369 * kmem_cache structures of all caches, except cache_cache itself:
1370 * cache_cache is statically allocated.
1371 * Initially an __init data area is used for the head array and the
1372 * kmem_list3 structures, it's replaced with a kmalloc allocated
1373 * array at the end of the bootstrap.
1374 * 2) Create the first kmalloc cache.
1375 * The struct kmem_cache for the new cache is allocated normally.
1376 * An __init data area is used for the head array.
1377 * 3) Create the remaining kmalloc caches, with minimally sized
1379 * 4) Replace the __init data head arrays for cache_cache and the first
1380 * kmalloc cache with kmalloc allocated arrays.
1381 * 5) Replace the __init data for kmem_list3 for cache_cache and
1382 * the other cache's with kmalloc allocated memory.
1383 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1386 /* 1) create the cache_cache */
1387 INIT_LIST_HEAD(&cache_chain
);
1388 list_add(&cache_cache
.next
, &cache_chain
);
1389 cache_cache
.colour_off
= cache_line_size();
1390 cache_cache
.array
[smp_processor_id()] = &initarray_cache
.cache
;
1391 cache_cache
.nodelists
[numa_node_id()] = &initkmem_list3
[CACHE_CACHE
];
1393 cache_cache
.buffer_size
= ALIGN(cache_cache
.buffer_size
,
1396 for (order
= 0; order
< MAX_ORDER
; order
++) {
1397 cache_estimate(order
, cache_cache
.buffer_size
,
1398 cache_line_size(), 0, &left_over
, &cache_cache
.num
);
1399 if (cache_cache
.num
)
1402 BUG_ON(!cache_cache
.num
);
1403 cache_cache
.gfporder
= order
;
1404 cache_cache
.colour
= left_over
/ cache_cache
.colour_off
;
1405 cache_cache
.slab_size
= ALIGN(cache_cache
.num
* sizeof(kmem_bufctl_t
) +
1406 sizeof(struct slab
), cache_line_size());
1408 /* 2+3) create the kmalloc caches */
1409 sizes
= malloc_sizes
;
1410 names
= cache_names
;
1413 * Initialize the caches that provide memory for the array cache and the
1414 * kmem_list3 structures first. Without this, further allocations will
1418 sizes
[INDEX_AC
].cs_cachep
= kmem_cache_create(names
[INDEX_AC
].name
,
1419 sizes
[INDEX_AC
].cs_size
,
1420 ARCH_KMALLOC_MINALIGN
,
1421 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1424 if (INDEX_AC
!= INDEX_L3
) {
1425 sizes
[INDEX_L3
].cs_cachep
=
1426 kmem_cache_create(names
[INDEX_L3
].name
,
1427 sizes
[INDEX_L3
].cs_size
,
1428 ARCH_KMALLOC_MINALIGN
,
1429 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1433 slab_early_init
= 0;
1435 while (sizes
->cs_size
!= ULONG_MAX
) {
1437 * For performance, all the general caches are L1 aligned.
1438 * This should be particularly beneficial on SMP boxes, as it
1439 * eliminates "false sharing".
1440 * Note for systems short on memory removing the alignment will
1441 * allow tighter packing of the smaller caches.
1443 if (!sizes
->cs_cachep
) {
1444 sizes
->cs_cachep
= kmem_cache_create(names
->name
,
1446 ARCH_KMALLOC_MINALIGN
,
1447 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1451 sizes
->cs_dmacachep
= kmem_cache_create(names
->name_dma
,
1453 ARCH_KMALLOC_MINALIGN
,
1454 ARCH_KMALLOC_FLAGS
|SLAB_CACHE_DMA
|
1460 /* 4) Replace the bootstrap head arrays */
1462 struct array_cache
*ptr
;
1464 ptr
= kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1466 local_irq_disable();
1467 BUG_ON(cpu_cache_get(&cache_cache
) != &initarray_cache
.cache
);
1468 memcpy(ptr
, cpu_cache_get(&cache_cache
),
1469 sizeof(struct arraycache_init
));
1471 * Do not assume that spinlocks can be initialized via memcpy:
1473 spin_lock_init(&ptr
->lock
);
1475 cache_cache
.array
[smp_processor_id()] = ptr
;
1478 ptr
= kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1480 local_irq_disable();
1481 BUG_ON(cpu_cache_get(malloc_sizes
[INDEX_AC
].cs_cachep
)
1482 != &initarray_generic
.cache
);
1483 memcpy(ptr
, cpu_cache_get(malloc_sizes
[INDEX_AC
].cs_cachep
),
1484 sizeof(struct arraycache_init
));
1486 * Do not assume that spinlocks can be initialized via memcpy:
1488 spin_lock_init(&ptr
->lock
);
1490 malloc_sizes
[INDEX_AC
].cs_cachep
->array
[smp_processor_id()] =
1494 /* 5) Replace the bootstrap kmem_list3's */
1497 /* Replace the static kmem_list3 structures for the boot cpu */
1498 init_list(&cache_cache
, &initkmem_list3
[CACHE_CACHE
],
1501 for_each_online_node(node
) {
1502 init_list(malloc_sizes
[INDEX_AC
].cs_cachep
,
1503 &initkmem_list3
[SIZE_AC
+ node
], node
);
1505 if (INDEX_AC
!= INDEX_L3
) {
1506 init_list(malloc_sizes
[INDEX_L3
].cs_cachep
,
1507 &initkmem_list3
[SIZE_L3
+ node
],
1513 /* 6) resize the head arrays to their final sizes */
1515 struct kmem_cache
*cachep
;
1516 mutex_lock(&cache_chain_mutex
);
1517 list_for_each_entry(cachep
, &cache_chain
, next
)
1518 if (enable_cpucache(cachep
))
1520 mutex_unlock(&cache_chain_mutex
);
1523 /* Annotate slab for lockdep -- annotate the malloc caches */
1528 g_cpucache_up
= FULL
;
1531 * Register a cpu startup notifier callback that initializes
1532 * cpu_cache_get for all new cpus
1534 register_cpu_notifier(&cpucache_notifier
);
1537 * The reap timers are started later, with a module init call: That part
1538 * of the kernel is not yet operational.
1542 static int __init
cpucache_init(void)
1547 * Register the timers that return unneeded pages to the page allocator
1549 for_each_online_cpu(cpu
)
1550 start_cpu_timer(cpu
);
1553 __initcall(cpucache_init
);
1556 * Interface to system's page allocator. No need to hold the cache-lock.
1558 * If we requested dmaable memory, we will get it. Even if we
1559 * did not request dmaable memory, we might get it, but that
1560 * would be relatively rare and ignorable.
1562 static void *kmem_getpages(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
1570 * Nommu uses slab's for process anonymous memory allocations, and thus
1571 * requires __GFP_COMP to properly refcount higher order allocations
1573 flags
|= __GFP_COMP
;
1575 flags
|= cachep
->gfpflags
;
1577 page
= alloc_pages_node(nodeid
, flags
, cachep
->gfporder
);
1581 nr_pages
= (1 << cachep
->gfporder
);
1582 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1583 atomic_add(nr_pages
, &slab_reclaim_pages
);
1584 add_zone_page_state(page_zone(page
), NR_SLAB
, nr_pages
);
1585 for (i
= 0; i
< nr_pages
; i
++)
1586 __SetPageSlab(page
+ i
);
1587 return page_address(page
);
1591 * Interface to system's page release.
1593 static void kmem_freepages(struct kmem_cache
*cachep
, void *addr
)
1595 unsigned long i
= (1 << cachep
->gfporder
);
1596 struct page
*page
= virt_to_page(addr
);
1597 const unsigned long nr_freed
= i
;
1599 sub_zone_page_state(page_zone(page
), NR_SLAB
, nr_freed
);
1601 BUG_ON(!PageSlab(page
));
1602 __ClearPageSlab(page
);
1605 if (current
->reclaim_state
)
1606 current
->reclaim_state
->reclaimed_slab
+= nr_freed
;
1607 free_pages((unsigned long)addr
, cachep
->gfporder
);
1608 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1609 atomic_sub(1 << cachep
->gfporder
, &slab_reclaim_pages
);
1612 static void kmem_rcu_free(struct rcu_head
*head
)
1614 struct slab_rcu
*slab_rcu
= (struct slab_rcu
*)head
;
1615 struct kmem_cache
*cachep
= slab_rcu
->cachep
;
1617 kmem_freepages(cachep
, slab_rcu
->addr
);
1618 if (OFF_SLAB(cachep
))
1619 kmem_cache_free(cachep
->slabp_cache
, slab_rcu
);
1624 #ifdef CONFIG_DEBUG_PAGEALLOC
1625 static void store_stackinfo(struct kmem_cache
*cachep
, unsigned long *addr
,
1626 unsigned long caller
)
1628 int size
= obj_size(cachep
);
1630 addr
= (unsigned long *)&((char *)addr
)[obj_offset(cachep
)];
1632 if (size
< 5 * sizeof(unsigned long))
1635 *addr
++ = 0x12345678;
1637 *addr
++ = smp_processor_id();
1638 size
-= 3 * sizeof(unsigned long);
1640 unsigned long *sptr
= &caller
;
1641 unsigned long svalue
;
1643 while (!kstack_end(sptr
)) {
1645 if (kernel_text_address(svalue
)) {
1647 size
-= sizeof(unsigned long);
1648 if (size
<= sizeof(unsigned long))
1654 *addr
++ = 0x87654321;
1658 static void poison_obj(struct kmem_cache
*cachep
, void *addr
, unsigned char val
)
1660 int size
= obj_size(cachep
);
1661 addr
= &((char *)addr
)[obj_offset(cachep
)];
1663 memset(addr
, val
, size
);
1664 *(unsigned char *)(addr
+ size
- 1) = POISON_END
;
1667 static void dump_line(char *data
, int offset
, int limit
)
1670 printk(KERN_ERR
"%03x:", offset
);
1671 for (i
= 0; i
< limit
; i
++)
1672 printk(" %02x", (unsigned char)data
[offset
+ i
]);
1679 static void print_objinfo(struct kmem_cache
*cachep
, void *objp
, int lines
)
1684 if (cachep
->flags
& SLAB_RED_ZONE
) {
1685 printk(KERN_ERR
"Redzone: 0x%lx/0x%lx.\n",
1686 *dbg_redzone1(cachep
, objp
),
1687 *dbg_redzone2(cachep
, objp
));
1690 if (cachep
->flags
& SLAB_STORE_USER
) {
1691 printk(KERN_ERR
"Last user: [<%p>]",
1692 *dbg_userword(cachep
, objp
));
1693 print_symbol("(%s)",
1694 (unsigned long)*dbg_userword(cachep
, objp
));
1697 realobj
= (char *)objp
+ obj_offset(cachep
);
1698 size
= obj_size(cachep
);
1699 for (i
= 0; i
< size
&& lines
; i
+= 16, lines
--) {
1702 if (i
+ limit
> size
)
1704 dump_line(realobj
, i
, limit
);
1708 static void check_poison_obj(struct kmem_cache
*cachep
, void *objp
)
1714 realobj
= (char *)objp
+ obj_offset(cachep
);
1715 size
= obj_size(cachep
);
1717 for (i
= 0; i
< size
; i
++) {
1718 char exp
= POISON_FREE
;
1721 if (realobj
[i
] != exp
) {
1727 "Slab corruption: start=%p, len=%d\n",
1729 print_objinfo(cachep
, objp
, 0);
1731 /* Hexdump the affected line */
1734 if (i
+ limit
> size
)
1736 dump_line(realobj
, i
, limit
);
1739 /* Limit to 5 lines */
1745 /* Print some data about the neighboring objects, if they
1748 struct slab
*slabp
= virt_to_slab(objp
);
1751 objnr
= obj_to_index(cachep
, slabp
, objp
);
1753 objp
= index_to_obj(cachep
, slabp
, objnr
- 1);
1754 realobj
= (char *)objp
+ obj_offset(cachep
);
1755 printk(KERN_ERR
"Prev obj: start=%p, len=%d\n",
1757 print_objinfo(cachep
, objp
, 2);
1759 if (objnr
+ 1 < cachep
->num
) {
1760 objp
= index_to_obj(cachep
, slabp
, objnr
+ 1);
1761 realobj
= (char *)objp
+ obj_offset(cachep
);
1762 printk(KERN_ERR
"Next obj: start=%p, len=%d\n",
1764 print_objinfo(cachep
, objp
, 2);
1772 * slab_destroy_objs - destroy a slab and its objects
1773 * @cachep: cache pointer being destroyed
1774 * @slabp: slab pointer being destroyed
1776 * Call the registered destructor for each object in a slab that is being
1779 static void slab_destroy_objs(struct kmem_cache
*cachep
, struct slab
*slabp
)
1782 for (i
= 0; i
< cachep
->num
; i
++) {
1783 void *objp
= index_to_obj(cachep
, slabp
, i
);
1785 if (cachep
->flags
& SLAB_POISON
) {
1786 #ifdef CONFIG_DEBUG_PAGEALLOC
1787 if (cachep
->buffer_size
% PAGE_SIZE
== 0 &&
1789 kernel_map_pages(virt_to_page(objp
),
1790 cachep
->buffer_size
/ PAGE_SIZE
, 1);
1792 check_poison_obj(cachep
, objp
);
1794 check_poison_obj(cachep
, objp
);
1797 if (cachep
->flags
& SLAB_RED_ZONE
) {
1798 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
1799 slab_error(cachep
, "start of a freed object "
1801 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
1802 slab_error(cachep
, "end of a freed object "
1805 if (cachep
->dtor
&& !(cachep
->flags
& SLAB_POISON
))
1806 (cachep
->dtor
) (objp
+ obj_offset(cachep
), cachep
, 0);
1810 static void slab_destroy_objs(struct kmem_cache
*cachep
, struct slab
*slabp
)
1814 for (i
= 0; i
< cachep
->num
; i
++) {
1815 void *objp
= index_to_obj(cachep
, slabp
, i
);
1816 (cachep
->dtor
) (objp
, cachep
, 0);
1823 * slab_destroy - destroy and release all objects in a slab
1824 * @cachep: cache pointer being destroyed
1825 * @slabp: slab pointer being destroyed
1827 * Destroy all the objs in a slab, and release the mem back to the system.
1828 * Before calling the slab must have been unlinked from the cache. The
1829 * cache-lock is not held/needed.
1831 static void slab_destroy(struct kmem_cache
*cachep
, struct slab
*slabp
)
1833 void *addr
= slabp
->s_mem
- slabp
->colouroff
;
1835 slab_destroy_objs(cachep
, slabp
);
1836 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
)) {
1837 struct slab_rcu
*slab_rcu
;
1839 slab_rcu
= (struct slab_rcu
*)slabp
;
1840 slab_rcu
->cachep
= cachep
;
1841 slab_rcu
->addr
= addr
;
1842 call_rcu(&slab_rcu
->head
, kmem_rcu_free
);
1844 kmem_freepages(cachep
, addr
);
1845 if (OFF_SLAB(cachep
))
1846 kmem_cache_free(cachep
->slabp_cache
, slabp
);
1851 * For setting up all the kmem_list3s for cache whose buffer_size is same as
1852 * size of kmem_list3.
1854 static void set_up_list3s(struct kmem_cache
*cachep
, int index
)
1858 for_each_online_node(node
) {
1859 cachep
->nodelists
[node
] = &initkmem_list3
[index
+ node
];
1860 cachep
->nodelists
[node
]->next_reap
= jiffies
+
1862 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1866 static void __kmem_cache_destroy(struct kmem_cache
*cachep
)
1869 struct kmem_list3
*l3
;
1871 for_each_online_cpu(i
)
1872 kfree(cachep
->array
[i
]);
1874 /* NUMA: free the list3 structures */
1875 for_each_online_node(i
) {
1876 l3
= cachep
->nodelists
[i
];
1879 free_alien_cache(l3
->alien
);
1883 kmem_cache_free(&cache_cache
, cachep
);
1888 * calculate_slab_order - calculate size (page order) of slabs
1889 * @cachep: pointer to the cache that is being created
1890 * @size: size of objects to be created in this cache.
1891 * @align: required alignment for the objects.
1892 * @flags: slab allocation flags
1894 * Also calculates the number of objects per slab.
1896 * This could be made much more intelligent. For now, try to avoid using
1897 * high order pages for slabs. When the gfp() functions are more friendly
1898 * towards high-order requests, this should be changed.
1900 static size_t calculate_slab_order(struct kmem_cache
*cachep
,
1901 size_t size
, size_t align
, unsigned long flags
)
1903 unsigned long offslab_limit
;
1904 size_t left_over
= 0;
1907 for (gfporder
= 0; gfporder
<= MAX_GFP_ORDER
; gfporder
++) {
1911 cache_estimate(gfporder
, size
, align
, flags
, &remainder
, &num
);
1915 if (flags
& CFLGS_OFF_SLAB
) {
1917 * Max number of objs-per-slab for caches which
1918 * use off-slab slabs. Needed to avoid a possible
1919 * looping condition in cache_grow().
1921 offslab_limit
= size
- sizeof(struct slab
);
1922 offslab_limit
/= sizeof(kmem_bufctl_t
);
1924 if (num
> offslab_limit
)
1928 /* Found something acceptable - save it away */
1930 cachep
->gfporder
= gfporder
;
1931 left_over
= remainder
;
1934 * A VFS-reclaimable slab tends to have most allocations
1935 * as GFP_NOFS and we really don't want to have to be allocating
1936 * higher-order pages when we are unable to shrink dcache.
1938 if (flags
& SLAB_RECLAIM_ACCOUNT
)
1942 * Large number of objects is good, but very large slabs are
1943 * currently bad for the gfp()s.
1945 if (gfporder
>= slab_break_gfp_order
)
1949 * Acceptable internal fragmentation?
1951 if (left_over
* 8 <= (PAGE_SIZE
<< gfporder
))
1957 static int setup_cpu_cache(struct kmem_cache
*cachep
)
1959 if (g_cpucache_up
== FULL
)
1960 return enable_cpucache(cachep
);
1962 if (g_cpucache_up
== NONE
) {
1964 * Note: the first kmem_cache_create must create the cache
1965 * that's used by kmalloc(24), otherwise the creation of
1966 * further caches will BUG().
1968 cachep
->array
[smp_processor_id()] = &initarray_generic
.cache
;
1971 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
1972 * the first cache, then we need to set up all its list3s,
1973 * otherwise the creation of further caches will BUG().
1975 set_up_list3s(cachep
, SIZE_AC
);
1976 if (INDEX_AC
== INDEX_L3
)
1977 g_cpucache_up
= PARTIAL_L3
;
1979 g_cpucache_up
= PARTIAL_AC
;
1981 cachep
->array
[smp_processor_id()] =
1982 kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1984 if (g_cpucache_up
== PARTIAL_AC
) {
1985 set_up_list3s(cachep
, SIZE_L3
);
1986 g_cpucache_up
= PARTIAL_L3
;
1989 for_each_online_node(node
) {
1990 cachep
->nodelists
[node
] =
1991 kmalloc_node(sizeof(struct kmem_list3
),
1993 BUG_ON(!cachep
->nodelists
[node
]);
1994 kmem_list3_init(cachep
->nodelists
[node
]);
1998 cachep
->nodelists
[numa_node_id()]->next_reap
=
1999 jiffies
+ REAPTIMEOUT_LIST3
+
2000 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
2002 cpu_cache_get(cachep
)->avail
= 0;
2003 cpu_cache_get(cachep
)->limit
= BOOT_CPUCACHE_ENTRIES
;
2004 cpu_cache_get(cachep
)->batchcount
= 1;
2005 cpu_cache_get(cachep
)->touched
= 0;
2006 cachep
->batchcount
= 1;
2007 cachep
->limit
= BOOT_CPUCACHE_ENTRIES
;
2012 * kmem_cache_create - Create a cache.
2013 * @name: A string which is used in /proc/slabinfo to identify this cache.
2014 * @size: The size of objects to be created in this cache.
2015 * @align: The required alignment for the objects.
2016 * @flags: SLAB flags
2017 * @ctor: A constructor for the objects.
2018 * @dtor: A destructor for the objects.
2020 * Returns a ptr to the cache on success, NULL on failure.
2021 * Cannot be called within a int, but can be interrupted.
2022 * The @ctor is run when new pages are allocated by the cache
2023 * and the @dtor is run before the pages are handed back.
2025 * @name must be valid until the cache is destroyed. This implies that
2026 * the module calling this has to destroy the cache before getting unloaded.
2030 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2031 * to catch references to uninitialised memory.
2033 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2034 * for buffer overruns.
2036 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2037 * cacheline. This can be beneficial if you're counting cycles as closely
2041 kmem_cache_create (const char *name
, size_t size
, size_t align
,
2042 unsigned long flags
,
2043 void (*ctor
)(void*, struct kmem_cache
*, unsigned long),
2044 void (*dtor
)(void*, struct kmem_cache
*, unsigned long))
2046 size_t left_over
, slab_size
, ralign
;
2047 struct kmem_cache
*cachep
= NULL
, *pc
;
2050 * Sanity checks... these are all serious usage bugs.
2052 if (!name
|| in_interrupt() || (size
< BYTES_PER_WORD
) ||
2053 (size
> (1 << MAX_OBJ_ORDER
) * PAGE_SIZE
) || (dtor
&& !ctor
)) {
2054 printk(KERN_ERR
"%s: Early error in slab %s\n", __FUNCTION__
,
2060 * Prevent CPUs from coming and going.
2061 * lock_cpu_hotplug() nests outside cache_chain_mutex
2065 mutex_lock(&cache_chain_mutex
);
2067 list_for_each_entry(pc
, &cache_chain
, next
) {
2068 mm_segment_t old_fs
= get_fs();
2073 * This happens when the module gets unloaded and doesn't
2074 * destroy its slab cache and no-one else reuses the vmalloc
2075 * area of the module. Print a warning.
2078 res
= __get_user(tmp
, pc
->name
);
2081 printk("SLAB: cache with size %d has lost its name\n",
2086 if (!strcmp(pc
->name
, name
)) {
2087 printk("kmem_cache_create: duplicate cache %s\n", name
);
2094 WARN_ON(strchr(name
, ' ')); /* It confuses parsers */
2095 if ((flags
& SLAB_DEBUG_INITIAL
) && !ctor
) {
2096 /* No constructor, but inital state check requested */
2097 printk(KERN_ERR
"%s: No con, but init state check "
2098 "requested - %s\n", __FUNCTION__
, name
);
2099 flags
&= ~SLAB_DEBUG_INITIAL
;
2103 * Enable redzoning and last user accounting, except for caches with
2104 * large objects, if the increased size would increase the object size
2105 * above the next power of two: caches with object sizes just above a
2106 * power of two have a significant amount of internal fragmentation.
2108 if (size
< 4096 || fls(size
- 1) == fls(size
-1 + 3 * BYTES_PER_WORD
))
2109 flags
|= SLAB_RED_ZONE
| SLAB_STORE_USER
;
2110 if (!(flags
& SLAB_DESTROY_BY_RCU
))
2111 flags
|= SLAB_POISON
;
2113 if (flags
& SLAB_DESTROY_BY_RCU
)
2114 BUG_ON(flags
& SLAB_POISON
);
2116 if (flags
& SLAB_DESTROY_BY_RCU
)
2120 * Always checks flags, a caller might be expecting debug support which
2123 BUG_ON(flags
& ~CREATE_MASK
);
2126 * Check that size is in terms of words. This is needed to avoid
2127 * unaligned accesses for some archs when redzoning is used, and makes
2128 * sure any on-slab bufctl's are also correctly aligned.
2130 if (size
& (BYTES_PER_WORD
- 1)) {
2131 size
+= (BYTES_PER_WORD
- 1);
2132 size
&= ~(BYTES_PER_WORD
- 1);
2135 /* calculate the final buffer alignment: */
2137 /* 1) arch recommendation: can be overridden for debug */
2138 if (flags
& SLAB_HWCACHE_ALIGN
) {
2140 * Default alignment: as specified by the arch code. Except if
2141 * an object is really small, then squeeze multiple objects into
2144 ralign
= cache_line_size();
2145 while (size
<= ralign
/ 2)
2148 ralign
= BYTES_PER_WORD
;
2152 * Redzoning and user store require word alignment. Note this will be
2153 * overridden by architecture or caller mandated alignment if either
2154 * is greater than BYTES_PER_WORD.
2156 if (flags
& SLAB_RED_ZONE
|| flags
& SLAB_STORE_USER
)
2157 ralign
= BYTES_PER_WORD
;
2159 /* 2) arch mandated alignment: disables debug if necessary */
2160 if (ralign
< ARCH_SLAB_MINALIGN
) {
2161 ralign
= ARCH_SLAB_MINALIGN
;
2162 if (ralign
> BYTES_PER_WORD
)
2163 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2165 /* 3) caller mandated alignment: disables debug if necessary */
2166 if (ralign
< align
) {
2168 if (ralign
> BYTES_PER_WORD
)
2169 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2176 /* Get cache's description obj. */
2177 cachep
= kmem_cache_zalloc(&cache_cache
, SLAB_KERNEL
);
2182 cachep
->obj_size
= size
;
2185 * Both debugging options require word-alignment which is calculated
2188 if (flags
& SLAB_RED_ZONE
) {
2189 /* add space for red zone words */
2190 cachep
->obj_offset
+= BYTES_PER_WORD
;
2191 size
+= 2 * BYTES_PER_WORD
;
2193 if (flags
& SLAB_STORE_USER
) {
2194 /* user store requires one word storage behind the end of
2197 size
+= BYTES_PER_WORD
;
2199 #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
2200 if (size
>= malloc_sizes
[INDEX_L3
+ 1].cs_size
2201 && cachep
->obj_size
> cache_line_size() && size
< PAGE_SIZE
) {
2202 cachep
->obj_offset
+= PAGE_SIZE
- size
;
2209 * Determine if the slab management is 'on' or 'off' slab.
2210 * (bootstrapping cannot cope with offslab caches so don't do
2213 if ((size
>= (PAGE_SIZE
>> 3)) && !slab_early_init
)
2215 * Size is large, assume best to place the slab management obj
2216 * off-slab (should allow better packing of objs).
2218 flags
|= CFLGS_OFF_SLAB
;
2220 size
= ALIGN(size
, align
);
2222 left_over
= calculate_slab_order(cachep
, size
, align
, flags
);
2225 printk("kmem_cache_create: couldn't create cache %s.\n", name
);
2226 kmem_cache_free(&cache_cache
, cachep
);
2230 slab_size
= ALIGN(cachep
->num
* sizeof(kmem_bufctl_t
)
2231 + sizeof(struct slab
), align
);
2234 * If the slab has been placed off-slab, and we have enough space then
2235 * move it on-slab. This is at the expense of any extra colouring.
2237 if (flags
& CFLGS_OFF_SLAB
&& left_over
>= slab_size
) {
2238 flags
&= ~CFLGS_OFF_SLAB
;
2239 left_over
-= slab_size
;
2242 if (flags
& CFLGS_OFF_SLAB
) {
2243 /* really off slab. No need for manual alignment */
2245 cachep
->num
* sizeof(kmem_bufctl_t
) + sizeof(struct slab
);
2248 cachep
->colour_off
= cache_line_size();
2249 /* Offset must be a multiple of the alignment. */
2250 if (cachep
->colour_off
< align
)
2251 cachep
->colour_off
= align
;
2252 cachep
->colour
= left_over
/ cachep
->colour_off
;
2253 cachep
->slab_size
= slab_size
;
2254 cachep
->flags
= flags
;
2255 cachep
->gfpflags
= 0;
2256 if (flags
& SLAB_CACHE_DMA
)
2257 cachep
->gfpflags
|= GFP_DMA
;
2258 cachep
->buffer_size
= size
;
2260 if (flags
& CFLGS_OFF_SLAB
) {
2261 cachep
->slabp_cache
= kmem_find_general_cachep(slab_size
, 0u);
2263 * This is a possibility for one of the malloc_sizes caches.
2264 * But since we go off slab only for object size greater than
2265 * PAGE_SIZE/8, and malloc_sizes gets created in ascending order,
2266 * this should not happen at all.
2267 * But leave a BUG_ON for some lucky dude.
2269 BUG_ON(!cachep
->slabp_cache
);
2271 cachep
->ctor
= ctor
;
2272 cachep
->dtor
= dtor
;
2273 cachep
->name
= name
;
2275 if (setup_cpu_cache(cachep
)) {
2276 __kmem_cache_destroy(cachep
);
2281 /* cache setup completed, link it into the list */
2282 list_add(&cachep
->next
, &cache_chain
);
2284 if (!cachep
&& (flags
& SLAB_PANIC
))
2285 panic("kmem_cache_create(): failed to create slab `%s'\n",
2287 mutex_unlock(&cache_chain_mutex
);
2288 unlock_cpu_hotplug();
2291 EXPORT_SYMBOL(kmem_cache_create
);
2294 static void check_irq_off(void)
2296 BUG_ON(!irqs_disabled());
2299 static void check_irq_on(void)
2301 BUG_ON(irqs_disabled());
2304 static void check_spinlock_acquired(struct kmem_cache
*cachep
)
2308 assert_spin_locked(&cachep
->nodelists
[numa_node_id()]->list_lock
);
2312 static void check_spinlock_acquired_node(struct kmem_cache
*cachep
, int node
)
2316 assert_spin_locked(&cachep
->nodelists
[node
]->list_lock
);
2321 #define check_irq_off() do { } while(0)
2322 #define check_irq_on() do { } while(0)
2323 #define check_spinlock_acquired(x) do { } while(0)
2324 #define check_spinlock_acquired_node(x, y) do { } while(0)
2327 static void drain_array(struct kmem_cache
*cachep
, struct kmem_list3
*l3
,
2328 struct array_cache
*ac
,
2329 int force
, int node
);
2331 static void do_drain(void *arg
)
2333 struct kmem_cache
*cachep
= arg
;
2334 struct array_cache
*ac
;
2335 int node
= numa_node_id();
2338 ac
= cpu_cache_get(cachep
);
2339 spin_lock(&cachep
->nodelists
[node
]->list_lock
);
2340 free_block(cachep
, ac
->entry
, ac
->avail
, node
);
2341 spin_unlock(&cachep
->nodelists
[node
]->list_lock
);
2345 static void drain_cpu_caches(struct kmem_cache
*cachep
)
2347 struct kmem_list3
*l3
;
2350 on_each_cpu(do_drain
, cachep
, 1, 1);
2352 for_each_online_node(node
) {
2353 l3
= cachep
->nodelists
[node
];
2354 if (l3
&& l3
->alien
)
2355 drain_alien_cache(cachep
, l3
->alien
);
2358 for_each_online_node(node
) {
2359 l3
= cachep
->nodelists
[node
];
2361 drain_array(cachep
, l3
, l3
->shared
, 1, node
);
2366 * Remove slabs from the list of free slabs.
2367 * Specify the number of slabs to drain in tofree.
2369 * Returns the actual number of slabs released.
2371 static int drain_freelist(struct kmem_cache
*cache
,
2372 struct kmem_list3
*l3
, int tofree
)
2374 struct list_head
*p
;
2379 while (nr_freed
< tofree
&& !list_empty(&l3
->slabs_free
)) {
2381 spin_lock_irq(&l3
->list_lock
);
2382 p
= l3
->slabs_free
.prev
;
2383 if (p
== &l3
->slabs_free
) {
2384 spin_unlock_irq(&l3
->list_lock
);
2388 slabp
= list_entry(p
, struct slab
, list
);
2390 BUG_ON(slabp
->inuse
);
2392 list_del(&slabp
->list
);
2394 * Safe to drop the lock. The slab is no longer linked
2397 l3
->free_objects
-= cache
->num
;
2398 spin_unlock_irq(&l3
->list_lock
);
2399 slab_destroy(cache
, slabp
);
2406 static int __cache_shrink(struct kmem_cache
*cachep
)
2409 struct kmem_list3
*l3
;
2411 drain_cpu_caches(cachep
);
2414 for_each_online_node(i
) {
2415 l3
= cachep
->nodelists
[i
];
2419 drain_freelist(cachep
, l3
, l3
->free_objects
);
2421 ret
+= !list_empty(&l3
->slabs_full
) ||
2422 !list_empty(&l3
->slabs_partial
);
2424 return (ret
? 1 : 0);
2428 * kmem_cache_shrink - Shrink a cache.
2429 * @cachep: The cache to shrink.
2431 * Releases as many slabs as possible for a cache.
2432 * To help debugging, a zero exit status indicates all slabs were released.
2434 int kmem_cache_shrink(struct kmem_cache
*cachep
)
2436 BUG_ON(!cachep
|| in_interrupt());
2438 return __cache_shrink(cachep
);
2440 EXPORT_SYMBOL(kmem_cache_shrink
);
2443 * kmem_cache_destroy - delete a cache
2444 * @cachep: the cache to destroy
2446 * Remove a struct kmem_cache object from the slab cache.
2447 * Returns 0 on success.
2449 * It is expected this function will be called by a module when it is
2450 * unloaded. This will remove the cache completely, and avoid a duplicate
2451 * cache being allocated each time a module is loaded and unloaded, if the
2452 * module doesn't have persistent in-kernel storage across loads and unloads.
2454 * The cache must be empty before calling this function.
2456 * The caller must guarantee that noone will allocate memory from the cache
2457 * during the kmem_cache_destroy().
2459 int kmem_cache_destroy(struct kmem_cache
*cachep
)
2461 BUG_ON(!cachep
|| in_interrupt());
2463 /* Don't let CPUs to come and go */
2466 /* Find the cache in the chain of caches. */
2467 mutex_lock(&cache_chain_mutex
);
2469 * the chain is never empty, cache_cache is never destroyed
2471 list_del(&cachep
->next
);
2472 mutex_unlock(&cache_chain_mutex
);
2474 if (__cache_shrink(cachep
)) {
2475 slab_error(cachep
, "Can't free all objects");
2476 mutex_lock(&cache_chain_mutex
);
2477 list_add(&cachep
->next
, &cache_chain
);
2478 mutex_unlock(&cache_chain_mutex
);
2479 unlock_cpu_hotplug();
2483 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
))
2486 __kmem_cache_destroy(cachep
);
2487 unlock_cpu_hotplug();
2490 EXPORT_SYMBOL(kmem_cache_destroy
);
2493 * Get the memory for a slab management obj.
2494 * For a slab cache when the slab descriptor is off-slab, slab descriptors
2495 * always come from malloc_sizes caches. The slab descriptor cannot
2496 * come from the same cache which is getting created because,
2497 * when we are searching for an appropriate cache for these
2498 * descriptors in kmem_cache_create, we search through the malloc_sizes array.
2499 * If we are creating a malloc_sizes cache here it would not be visible to
2500 * kmem_find_general_cachep till the initialization is complete.
2501 * Hence we cannot have slabp_cache same as the original cache.
2503 static struct slab
*alloc_slabmgmt(struct kmem_cache
*cachep
, void *objp
,
2504 int colour_off
, gfp_t local_flags
,
2509 if (OFF_SLAB(cachep
)) {
2510 /* Slab management obj is off-slab. */
2511 slabp
= kmem_cache_alloc_node(cachep
->slabp_cache
,
2512 local_flags
, nodeid
);
2516 slabp
= objp
+ colour_off
;
2517 colour_off
+= cachep
->slab_size
;
2520 slabp
->colouroff
= colour_off
;
2521 slabp
->s_mem
= objp
+ colour_off
;
2522 slabp
->nodeid
= nodeid
;
2526 static inline kmem_bufctl_t
*slab_bufctl(struct slab
*slabp
)
2528 return (kmem_bufctl_t
*) (slabp
+ 1);
2531 static void cache_init_objs(struct kmem_cache
*cachep
,
2532 struct slab
*slabp
, unsigned long ctor_flags
)
2536 for (i
= 0; i
< cachep
->num
; i
++) {
2537 void *objp
= index_to_obj(cachep
, slabp
, i
);
2539 /* need to poison the objs? */
2540 if (cachep
->flags
& SLAB_POISON
)
2541 poison_obj(cachep
, objp
, POISON_FREE
);
2542 if (cachep
->flags
& SLAB_STORE_USER
)
2543 *dbg_userword(cachep
, objp
) = NULL
;
2545 if (cachep
->flags
& SLAB_RED_ZONE
) {
2546 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2547 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2550 * Constructors are not allowed to allocate memory from the same
2551 * cache which they are a constructor for. Otherwise, deadlock.
2552 * They must also be threaded.
2554 if (cachep
->ctor
&& !(cachep
->flags
& SLAB_POISON
))
2555 cachep
->ctor(objp
+ obj_offset(cachep
), cachep
,
2558 if (cachep
->flags
& SLAB_RED_ZONE
) {
2559 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
2560 slab_error(cachep
, "constructor overwrote the"
2561 " end of an object");
2562 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
2563 slab_error(cachep
, "constructor overwrote the"
2564 " start of an object");
2566 if ((cachep
->buffer_size
% PAGE_SIZE
) == 0 &&
2567 OFF_SLAB(cachep
) && cachep
->flags
& SLAB_POISON
)
2568 kernel_map_pages(virt_to_page(objp
),
2569 cachep
->buffer_size
/ PAGE_SIZE
, 0);
2572 cachep
->ctor(objp
, cachep
, ctor_flags
);
2574 slab_bufctl(slabp
)[i
] = i
+ 1;
2576 slab_bufctl(slabp
)[i
- 1] = BUFCTL_END
;
2580 static void kmem_flagcheck(struct kmem_cache
*cachep
, gfp_t flags
)
2582 if (flags
& SLAB_DMA
)
2583 BUG_ON(!(cachep
->gfpflags
& GFP_DMA
));
2585 BUG_ON(cachep
->gfpflags
& GFP_DMA
);
2588 static void *slab_get_obj(struct kmem_cache
*cachep
, struct slab
*slabp
,
2591 void *objp
= index_to_obj(cachep
, slabp
, slabp
->free
);
2595 next
= slab_bufctl(slabp
)[slabp
->free
];
2597 slab_bufctl(slabp
)[slabp
->free
] = BUFCTL_FREE
;
2598 WARN_ON(slabp
->nodeid
!= nodeid
);
2605 static void slab_put_obj(struct kmem_cache
*cachep
, struct slab
*slabp
,
2606 void *objp
, int nodeid
)
2608 unsigned int objnr
= obj_to_index(cachep
, slabp
, objp
);
2611 /* Verify that the slab belongs to the intended node */
2612 WARN_ON(slabp
->nodeid
!= nodeid
);
2614 if (slab_bufctl(slabp
)[objnr
] + 1 <= SLAB_LIMIT
+ 1) {
2615 printk(KERN_ERR
"slab: double free detected in cache "
2616 "'%s', objp %p\n", cachep
->name
, objp
);
2620 slab_bufctl(slabp
)[objnr
] = slabp
->free
;
2621 slabp
->free
= objnr
;
2626 * Map pages beginning at addr to the given cache and slab. This is required
2627 * for the slab allocator to be able to lookup the cache and slab of a
2628 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
2630 static void slab_map_pages(struct kmem_cache
*cache
, struct slab
*slab
,
2636 page
= virt_to_page(addr
);
2639 if (likely(!PageCompound(page
)))
2640 nr_pages
<<= cache
->gfporder
;
2643 page_set_cache(page
, cache
);
2644 page_set_slab(page
, slab
);
2646 } while (--nr_pages
);
2650 * Grow (by 1) the number of slabs within a cache. This is called by
2651 * kmem_cache_alloc() when there are no active objs left in a cache.
2653 static int cache_grow(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
2659 unsigned long ctor_flags
;
2660 struct kmem_list3
*l3
;
2663 * Be lazy and only check for valid flags here, keeping it out of the
2664 * critical path in kmem_cache_alloc().
2666 BUG_ON(flags
& ~(SLAB_DMA
| SLAB_LEVEL_MASK
| SLAB_NO_GROW
));
2667 if (flags
& SLAB_NO_GROW
)
2670 ctor_flags
= SLAB_CTOR_CONSTRUCTOR
;
2671 local_flags
= (flags
& SLAB_LEVEL_MASK
);
2672 if (!(local_flags
& __GFP_WAIT
))
2674 * Not allowed to sleep. Need to tell a constructor about
2675 * this - it might need to know...
2677 ctor_flags
|= SLAB_CTOR_ATOMIC
;
2679 /* Take the l3 list lock to change the colour_next on this node */
2681 l3
= cachep
->nodelists
[nodeid
];
2682 spin_lock(&l3
->list_lock
);
2684 /* Get colour for the slab, and cal the next value. */
2685 offset
= l3
->colour_next
;
2687 if (l3
->colour_next
>= cachep
->colour
)
2688 l3
->colour_next
= 0;
2689 spin_unlock(&l3
->list_lock
);
2691 offset
*= cachep
->colour_off
;
2693 if (local_flags
& __GFP_WAIT
)
2697 * The test for missing atomic flag is performed here, rather than
2698 * the more obvious place, simply to reduce the critical path length
2699 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2700 * will eventually be caught here (where it matters).
2702 kmem_flagcheck(cachep
, flags
);
2705 * Get mem for the objs. Attempt to allocate a physical page from
2708 objp
= kmem_getpages(cachep
, flags
, nodeid
);
2712 /* Get slab management. */
2713 slabp
= alloc_slabmgmt(cachep
, objp
, offset
, local_flags
, nodeid
);
2717 slabp
->nodeid
= nodeid
;
2718 slab_map_pages(cachep
, slabp
, objp
);
2720 cache_init_objs(cachep
, slabp
, ctor_flags
);
2722 if (local_flags
& __GFP_WAIT
)
2723 local_irq_disable();
2725 spin_lock(&l3
->list_lock
);
2727 /* Make slab active. */
2728 list_add_tail(&slabp
->list
, &(l3
->slabs_free
));
2729 STATS_INC_GROWN(cachep
);
2730 l3
->free_objects
+= cachep
->num
;
2731 spin_unlock(&l3
->list_lock
);
2734 kmem_freepages(cachep
, objp
);
2736 if (local_flags
& __GFP_WAIT
)
2737 local_irq_disable();
2744 * Perform extra freeing checks:
2745 * - detect bad pointers.
2746 * - POISON/RED_ZONE checking
2747 * - destructor calls, for caches with POISON+dtor
2749 static void kfree_debugcheck(const void *objp
)
2753 if (!virt_addr_valid(objp
)) {
2754 printk(KERN_ERR
"kfree_debugcheck: out of range ptr %lxh.\n",
2755 (unsigned long)objp
);
2758 page
= virt_to_page(objp
);
2759 if (!PageSlab(page
)) {
2760 printk(KERN_ERR
"kfree_debugcheck: bad ptr %lxh.\n",
2761 (unsigned long)objp
);
2766 static inline void verify_redzone_free(struct kmem_cache
*cache
, void *obj
)
2768 unsigned long redzone1
, redzone2
;
2770 redzone1
= *dbg_redzone1(cache
, obj
);
2771 redzone2
= *dbg_redzone2(cache
, obj
);
2776 if (redzone1
== RED_ACTIVE
&& redzone2
== RED_ACTIVE
)
2779 if (redzone1
== RED_INACTIVE
&& redzone2
== RED_INACTIVE
)
2780 slab_error(cache
, "double free detected");
2782 slab_error(cache
, "memory outside object was overwritten");
2784 printk(KERN_ERR
"%p: redzone 1:0x%lx, redzone 2:0x%lx.\n",
2785 obj
, redzone1
, redzone2
);
2788 static void *cache_free_debugcheck(struct kmem_cache
*cachep
, void *objp
,
2795 objp
-= obj_offset(cachep
);
2796 kfree_debugcheck(objp
);
2797 page
= virt_to_page(objp
);
2799 slabp
= page_get_slab(page
);
2801 if (cachep
->flags
& SLAB_RED_ZONE
) {
2802 verify_redzone_free(cachep
, objp
);
2803 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2804 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2806 if (cachep
->flags
& SLAB_STORE_USER
)
2807 *dbg_userword(cachep
, objp
) = caller
;
2809 objnr
= obj_to_index(cachep
, slabp
, objp
);
2811 BUG_ON(objnr
>= cachep
->num
);
2812 BUG_ON(objp
!= index_to_obj(cachep
, slabp
, objnr
));
2814 if (cachep
->flags
& SLAB_DEBUG_INITIAL
) {
2816 * Need to call the slab's constructor so the caller can
2817 * perform a verify of its state (debugging). Called without
2818 * the cache-lock held.
2820 cachep
->ctor(objp
+ obj_offset(cachep
),
2821 cachep
, SLAB_CTOR_CONSTRUCTOR
| SLAB_CTOR_VERIFY
);
2823 if (cachep
->flags
& SLAB_POISON
&& cachep
->dtor
) {
2824 /* we want to cache poison the object,
2825 * call the destruction callback
2827 cachep
->dtor(objp
+ obj_offset(cachep
), cachep
, 0);
2829 #ifdef CONFIG_DEBUG_SLAB_LEAK
2830 slab_bufctl(slabp
)[objnr
] = BUFCTL_FREE
;
2832 if (cachep
->flags
& SLAB_POISON
) {
2833 #ifdef CONFIG_DEBUG_PAGEALLOC
2834 if ((cachep
->buffer_size
% PAGE_SIZE
)==0 && OFF_SLAB(cachep
)) {
2835 store_stackinfo(cachep
, objp
, (unsigned long)caller
);
2836 kernel_map_pages(virt_to_page(objp
),
2837 cachep
->buffer_size
/ PAGE_SIZE
, 0);
2839 poison_obj(cachep
, objp
, POISON_FREE
);
2842 poison_obj(cachep
, objp
, POISON_FREE
);
2848 static void check_slabp(struct kmem_cache
*cachep
, struct slab
*slabp
)
2853 /* Check slab's freelist to see if this obj is there. */
2854 for (i
= slabp
->free
; i
!= BUFCTL_END
; i
= slab_bufctl(slabp
)[i
]) {
2856 if (entries
> cachep
->num
|| i
>= cachep
->num
)
2859 if (entries
!= cachep
->num
- slabp
->inuse
) {
2861 printk(KERN_ERR
"slab: Internal list corruption detected in "
2862 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2863 cachep
->name
, cachep
->num
, slabp
, slabp
->inuse
);
2865 i
< sizeof(*slabp
) + cachep
->num
* sizeof(kmem_bufctl_t
);
2868 printk("\n%03x:", i
);
2869 printk(" %02x", ((unsigned char *)slabp
)[i
]);
2876 #define kfree_debugcheck(x) do { } while(0)
2877 #define cache_free_debugcheck(x,objp,z) (objp)
2878 #define check_slabp(x,y) do { } while(0)
2881 static void *cache_alloc_refill(struct kmem_cache
*cachep
, gfp_t flags
)
2884 struct kmem_list3
*l3
;
2885 struct array_cache
*ac
;
2888 ac
= cpu_cache_get(cachep
);
2890 batchcount
= ac
->batchcount
;
2891 if (!ac
->touched
&& batchcount
> BATCHREFILL_LIMIT
) {
2893 * If there was little recent activity on this cache, then
2894 * perform only a partial refill. Otherwise we could generate
2897 batchcount
= BATCHREFILL_LIMIT
;
2899 l3
= cachep
->nodelists
[numa_node_id()];
2901 BUG_ON(ac
->avail
> 0 || !l3
);
2902 spin_lock(&l3
->list_lock
);
2904 /* See if we can refill from the shared array */
2905 if (l3
->shared
&& transfer_objects(ac
, l3
->shared
, batchcount
))
2908 while (batchcount
> 0) {
2909 struct list_head
*entry
;
2911 /* Get slab alloc is to come from. */
2912 entry
= l3
->slabs_partial
.next
;
2913 if (entry
== &l3
->slabs_partial
) {
2914 l3
->free_touched
= 1;
2915 entry
= l3
->slabs_free
.next
;
2916 if (entry
== &l3
->slabs_free
)
2920 slabp
= list_entry(entry
, struct slab
, list
);
2921 check_slabp(cachep
, slabp
);
2922 check_spinlock_acquired(cachep
);
2923 while (slabp
->inuse
< cachep
->num
&& batchcount
--) {
2924 STATS_INC_ALLOCED(cachep
);
2925 STATS_INC_ACTIVE(cachep
);
2926 STATS_SET_HIGH(cachep
);
2928 ac
->entry
[ac
->avail
++] = slab_get_obj(cachep
, slabp
,
2931 check_slabp(cachep
, slabp
);
2933 /* move slabp to correct slabp list: */
2934 list_del(&slabp
->list
);
2935 if (slabp
->free
== BUFCTL_END
)
2936 list_add(&slabp
->list
, &l3
->slabs_full
);
2938 list_add(&slabp
->list
, &l3
->slabs_partial
);
2942 l3
->free_objects
-= ac
->avail
;
2944 spin_unlock(&l3
->list_lock
);
2946 if (unlikely(!ac
->avail
)) {
2948 x
= cache_grow(cachep
, flags
, numa_node_id());
2950 /* cache_grow can reenable interrupts, then ac could change. */
2951 ac
= cpu_cache_get(cachep
);
2952 if (!x
&& ac
->avail
== 0) /* no objects in sight? abort */
2955 if (!ac
->avail
) /* objects refilled by interrupt? */
2959 return ac
->entry
[--ac
->avail
];
2962 static inline void cache_alloc_debugcheck_before(struct kmem_cache
*cachep
,
2965 might_sleep_if(flags
& __GFP_WAIT
);
2967 kmem_flagcheck(cachep
, flags
);
2972 static void *cache_alloc_debugcheck_after(struct kmem_cache
*cachep
,
2973 gfp_t flags
, void *objp
, void *caller
)
2977 if (cachep
->flags
& SLAB_POISON
) {
2978 #ifdef CONFIG_DEBUG_PAGEALLOC
2979 if ((cachep
->buffer_size
% PAGE_SIZE
) == 0 && OFF_SLAB(cachep
))
2980 kernel_map_pages(virt_to_page(objp
),
2981 cachep
->buffer_size
/ PAGE_SIZE
, 1);
2983 check_poison_obj(cachep
, objp
);
2985 check_poison_obj(cachep
, objp
);
2987 poison_obj(cachep
, objp
, POISON_INUSE
);
2989 if (cachep
->flags
& SLAB_STORE_USER
)
2990 *dbg_userword(cachep
, objp
) = caller
;
2992 if (cachep
->flags
& SLAB_RED_ZONE
) {
2993 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
||
2994 *dbg_redzone2(cachep
, objp
) != RED_INACTIVE
) {
2995 slab_error(cachep
, "double free, or memory outside"
2996 " object was overwritten");
2998 "%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
2999 objp
, *dbg_redzone1(cachep
, objp
),
3000 *dbg_redzone2(cachep
, objp
));
3002 *dbg_redzone1(cachep
, objp
) = RED_ACTIVE
;
3003 *dbg_redzone2(cachep
, objp
) = RED_ACTIVE
;
3005 #ifdef CONFIG_DEBUG_SLAB_LEAK
3010 slabp
= page_get_slab(virt_to_page(objp
));
3011 objnr
= (unsigned)(objp
- slabp
->s_mem
) / cachep
->buffer_size
;
3012 slab_bufctl(slabp
)[objnr
] = BUFCTL_ACTIVE
;
3015 objp
+= obj_offset(cachep
);
3016 if (cachep
->ctor
&& cachep
->flags
& SLAB_POISON
) {
3017 unsigned long ctor_flags
= SLAB_CTOR_CONSTRUCTOR
;
3019 if (!(flags
& __GFP_WAIT
))
3020 ctor_flags
|= SLAB_CTOR_ATOMIC
;
3022 cachep
->ctor(objp
, cachep
, ctor_flags
);
3027 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
3030 static inline void *____cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3033 struct array_cache
*ac
;
3036 if (unlikely(current
->flags
& (PF_SPREAD_SLAB
| PF_MEMPOLICY
))) {
3037 objp
= alternate_node_alloc(cachep
, flags
);
3044 ac
= cpu_cache_get(cachep
);
3045 if (likely(ac
->avail
)) {
3046 STATS_INC_ALLOCHIT(cachep
);
3048 objp
= ac
->entry
[--ac
->avail
];
3050 STATS_INC_ALLOCMISS(cachep
);
3051 objp
= cache_alloc_refill(cachep
, flags
);
3056 static __always_inline
void *__cache_alloc(struct kmem_cache
*cachep
,
3057 gfp_t flags
, void *caller
)
3059 unsigned long save_flags
;
3062 cache_alloc_debugcheck_before(cachep
, flags
);
3064 local_irq_save(save_flags
);
3065 objp
= ____cache_alloc(cachep
, flags
);
3066 local_irq_restore(save_flags
);
3067 objp
= cache_alloc_debugcheck_after(cachep
, flags
, objp
,
3075 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
3077 * If we are in_interrupt, then process context, including cpusets and
3078 * mempolicy, may not apply and should not be used for allocation policy.
3080 static void *alternate_node_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3082 int nid_alloc
, nid_here
;
3086 nid_alloc
= nid_here
= numa_node_id();
3087 if (cpuset_do_slab_mem_spread() && (cachep
->flags
& SLAB_MEM_SPREAD
))
3088 nid_alloc
= cpuset_mem_spread_node();
3089 else if (current
->mempolicy
)
3090 nid_alloc
= slab_node(current
->mempolicy
);
3091 if (nid_alloc
!= nid_here
)
3092 return __cache_alloc_node(cachep
, flags
, nid_alloc
);
3097 * A interface to enable slab creation on nodeid
3099 static void *__cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
,
3102 struct list_head
*entry
;
3104 struct kmem_list3
*l3
;
3108 l3
= cachep
->nodelists
[nodeid
];
3113 spin_lock(&l3
->list_lock
);
3114 entry
= l3
->slabs_partial
.next
;
3115 if (entry
== &l3
->slabs_partial
) {
3116 l3
->free_touched
= 1;
3117 entry
= l3
->slabs_free
.next
;
3118 if (entry
== &l3
->slabs_free
)
3122 slabp
= list_entry(entry
, struct slab
, list
);
3123 check_spinlock_acquired_node(cachep
, nodeid
);
3124 check_slabp(cachep
, slabp
);
3126 STATS_INC_NODEALLOCS(cachep
);
3127 STATS_INC_ACTIVE(cachep
);
3128 STATS_SET_HIGH(cachep
);
3130 BUG_ON(slabp
->inuse
== cachep
->num
);
3132 obj
= slab_get_obj(cachep
, slabp
, nodeid
);
3133 check_slabp(cachep
, slabp
);
3135 /* move slabp to correct slabp list: */
3136 list_del(&slabp
->list
);
3138 if (slabp
->free
== BUFCTL_END
)
3139 list_add(&slabp
->list
, &l3
->slabs_full
);
3141 list_add(&slabp
->list
, &l3
->slabs_partial
);
3143 spin_unlock(&l3
->list_lock
);
3147 spin_unlock(&l3
->list_lock
);
3148 x
= cache_grow(cachep
, flags
, nodeid
);
3160 * Caller needs to acquire correct kmem_list's list_lock
3162 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int nr_objects
,
3166 struct kmem_list3
*l3
;
3168 for (i
= 0; i
< nr_objects
; i
++) {
3169 void *objp
= objpp
[i
];
3172 slabp
= virt_to_slab(objp
);
3173 l3
= cachep
->nodelists
[node
];
3174 list_del(&slabp
->list
);
3175 check_spinlock_acquired_node(cachep
, node
);
3176 check_slabp(cachep
, slabp
);
3177 slab_put_obj(cachep
, slabp
, objp
, node
);
3178 STATS_DEC_ACTIVE(cachep
);
3180 check_slabp(cachep
, slabp
);
3182 /* fixup slab chains */
3183 if (slabp
->inuse
== 0) {
3184 if (l3
->free_objects
> l3
->free_limit
) {
3185 l3
->free_objects
-= cachep
->num
;
3186 /* No need to drop any previously held
3187 * lock here, even if we have a off-slab slab
3188 * descriptor it is guaranteed to come from
3189 * a different cache, refer to comments before
3192 slab_destroy(cachep
, slabp
);
3194 list_add(&slabp
->list
, &l3
->slabs_free
);
3197 /* Unconditionally move a slab to the end of the
3198 * partial list on free - maximum time for the
3199 * other objects to be freed, too.
3201 list_add_tail(&slabp
->list
, &l3
->slabs_partial
);
3206 static void cache_flusharray(struct kmem_cache
*cachep
, struct array_cache
*ac
)
3209 struct kmem_list3
*l3
;
3210 int node
= numa_node_id();
3212 batchcount
= ac
->batchcount
;
3214 BUG_ON(!batchcount
|| batchcount
> ac
->avail
);
3217 l3
= cachep
->nodelists
[node
];
3218 spin_lock(&l3
->list_lock
);
3220 struct array_cache
*shared_array
= l3
->shared
;
3221 int max
= shared_array
->limit
- shared_array
->avail
;
3223 if (batchcount
> max
)
3225 memcpy(&(shared_array
->entry
[shared_array
->avail
]),
3226 ac
->entry
, sizeof(void *) * batchcount
);
3227 shared_array
->avail
+= batchcount
;
3232 free_block(cachep
, ac
->entry
, batchcount
, node
);
3237 struct list_head
*p
;
3239 p
= l3
->slabs_free
.next
;
3240 while (p
!= &(l3
->slabs_free
)) {
3243 slabp
= list_entry(p
, struct slab
, list
);
3244 BUG_ON(slabp
->inuse
);
3249 STATS_SET_FREEABLE(cachep
, i
);
3252 spin_unlock(&l3
->list_lock
);
3253 ac
->avail
-= batchcount
;
3254 memmove(ac
->entry
, &(ac
->entry
[batchcount
]), sizeof(void *)*ac
->avail
);
3258 * Release an obj back to its cache. If the obj has a constructed state, it must
3259 * be in this state _before_ it is released. Called with disabled ints.
3261 static inline void __cache_free(struct kmem_cache
*cachep
, void *objp
)
3263 struct array_cache
*ac
= cpu_cache_get(cachep
);
3266 objp
= cache_free_debugcheck(cachep
, objp
, __builtin_return_address(0));
3268 if (cache_free_alien(cachep
, objp
))
3271 if (likely(ac
->avail
< ac
->limit
)) {
3272 STATS_INC_FREEHIT(cachep
);
3273 ac
->entry
[ac
->avail
++] = objp
;
3276 STATS_INC_FREEMISS(cachep
);
3277 cache_flusharray(cachep
, ac
);
3278 ac
->entry
[ac
->avail
++] = objp
;
3283 * kmem_cache_alloc - Allocate an object
3284 * @cachep: The cache to allocate from.
3285 * @flags: See kmalloc().
3287 * Allocate an object from this cache. The flags are only relevant
3288 * if the cache has no available objects.
3290 void *kmem_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3292 return __cache_alloc(cachep
, flags
, __builtin_return_address(0));
3294 EXPORT_SYMBOL(kmem_cache_alloc
);
3297 * kmem_cache_zalloc - Allocate an object. The memory is set to zero.
3298 * @cache: The cache to allocate from.
3299 * @flags: See kmalloc().
3301 * Allocate an object from this cache and set the allocated memory to zero.
3302 * The flags are only relevant if the cache has no available objects.
3304 void *kmem_cache_zalloc(struct kmem_cache
*cache
, gfp_t flags
)
3306 void *ret
= __cache_alloc(cache
, flags
, __builtin_return_address(0));
3308 memset(ret
, 0, obj_size(cache
));
3311 EXPORT_SYMBOL(kmem_cache_zalloc
);
3314 * kmem_ptr_validate - check if an untrusted pointer might
3316 * @cachep: the cache we're checking against
3317 * @ptr: pointer to validate
3319 * This verifies that the untrusted pointer looks sane:
3320 * it is _not_ a guarantee that the pointer is actually
3321 * part of the slab cache in question, but it at least
3322 * validates that the pointer can be dereferenced and
3323 * looks half-way sane.
3325 * Currently only used for dentry validation.
3327 int fastcall
kmem_ptr_validate(struct kmem_cache
*cachep
, void *ptr
)
3329 unsigned long addr
= (unsigned long)ptr
;
3330 unsigned long min_addr
= PAGE_OFFSET
;
3331 unsigned long align_mask
= BYTES_PER_WORD
- 1;
3332 unsigned long size
= cachep
->buffer_size
;
3335 if (unlikely(addr
< min_addr
))
3337 if (unlikely(addr
> (unsigned long)high_memory
- size
))
3339 if (unlikely(addr
& align_mask
))
3341 if (unlikely(!kern_addr_valid(addr
)))
3343 if (unlikely(!kern_addr_valid(addr
+ size
- 1)))
3345 page
= virt_to_page(ptr
);
3346 if (unlikely(!PageSlab(page
)))
3348 if (unlikely(page_get_cache(page
) != cachep
))
3357 * kmem_cache_alloc_node - Allocate an object on the specified node
3358 * @cachep: The cache to allocate from.
3359 * @flags: See kmalloc().
3360 * @nodeid: node number of the target node.
3362 * Identical to kmem_cache_alloc, except that this function is slow
3363 * and can sleep. And it will allocate memory on the given node, which
3364 * can improve the performance for cpu bound structures.
3365 * New and improved: it will now make sure that the object gets
3366 * put on the correct node list so that there is no false sharing.
3368 void *kmem_cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
3370 unsigned long save_flags
;
3373 cache_alloc_debugcheck_before(cachep
, flags
);
3374 local_irq_save(save_flags
);
3376 if (nodeid
== -1 || nodeid
== numa_node_id() ||
3377 !cachep
->nodelists
[nodeid
])
3378 ptr
= ____cache_alloc(cachep
, flags
);
3380 ptr
= __cache_alloc_node(cachep
, flags
, nodeid
);
3381 local_irq_restore(save_flags
);
3383 ptr
= cache_alloc_debugcheck_after(cachep
, flags
, ptr
,
3384 __builtin_return_address(0));
3388 EXPORT_SYMBOL(kmem_cache_alloc_node
);
3390 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3392 struct kmem_cache
*cachep
;
3394 cachep
= kmem_find_general_cachep(size
, flags
);
3395 if (unlikely(cachep
== NULL
))
3397 return kmem_cache_alloc_node(cachep
, flags
, node
);
3399 EXPORT_SYMBOL(__kmalloc_node
);
3403 * __do_kmalloc - allocate memory
3404 * @size: how many bytes of memory are required.
3405 * @flags: the type of memory to allocate (see kmalloc).
3406 * @caller: function caller for debug tracking of the caller
3408 static __always_inline
void *__do_kmalloc(size_t size
, gfp_t flags
,
3411 struct kmem_cache
*cachep
;
3413 /* If you want to save a few bytes .text space: replace
3415 * Then kmalloc uses the uninlined functions instead of the inline
3418 cachep
= __find_general_cachep(size
, flags
);
3419 if (unlikely(cachep
== NULL
))
3421 return __cache_alloc(cachep
, flags
, caller
);
3425 void *__kmalloc(size_t size
, gfp_t flags
)
3427 #ifndef CONFIG_DEBUG_SLAB
3428 return __do_kmalloc(size
, flags
, NULL
);
3430 return __do_kmalloc(size
, flags
, __builtin_return_address(0));
3433 EXPORT_SYMBOL(__kmalloc
);
3435 #ifdef CONFIG_DEBUG_SLAB
3436 void *__kmalloc_track_caller(size_t size
, gfp_t flags
, void *caller
)
3438 return __do_kmalloc(size
, flags
, caller
);
3440 EXPORT_SYMBOL(__kmalloc_track_caller
);
3445 * percpu_depopulate - depopulate per-cpu data for given cpu
3446 * @__pdata: per-cpu data to depopulate
3447 * @cpu: depopulate per-cpu data for this cpu
3449 * Depopulating per-cpu data for a cpu going offline would be a typical
3450 * use case. You need to register a cpu hotplug handler for that purpose.
3452 void percpu_depopulate(void *__pdata
, int cpu
)
3454 struct percpu_data
*pdata
= __percpu_disguise(__pdata
);
3455 if (pdata
->ptrs
[cpu
]) {
3456 kfree(pdata
->ptrs
[cpu
]);
3457 pdata
->ptrs
[cpu
] = NULL
;
3460 EXPORT_SYMBOL_GPL(percpu_depopulate
);
3463 * percpu_depopulate_mask - depopulate per-cpu data for some cpu's
3464 * @__pdata: per-cpu data to depopulate
3465 * @mask: depopulate per-cpu data for cpu's selected through mask bits
3467 void __percpu_depopulate_mask(void *__pdata
, cpumask_t
*mask
)
3470 for_each_cpu_mask(cpu
, *mask
)
3471 percpu_depopulate(__pdata
, cpu
);
3473 EXPORT_SYMBOL_GPL(__percpu_depopulate_mask
);
3476 * percpu_populate - populate per-cpu data for given cpu
3477 * @__pdata: per-cpu data to populate further
3478 * @size: size of per-cpu object
3479 * @gfp: may sleep or not etc.
3480 * @cpu: populate per-data for this cpu
3482 * Populating per-cpu data for a cpu coming online would be a typical
3483 * use case. You need to register a cpu hotplug handler for that purpose.
3484 * Per-cpu object is populated with zeroed buffer.
3486 void *percpu_populate(void *__pdata
, size_t size
, gfp_t gfp
, int cpu
)
3488 struct percpu_data
*pdata
= __percpu_disguise(__pdata
);
3489 int node
= cpu_to_node(cpu
);
3491 BUG_ON(pdata
->ptrs
[cpu
]);
3492 if (node_online(node
)) {
3493 /* FIXME: kzalloc_node(size, gfp, node) */
3494 pdata
->ptrs
[cpu
] = kmalloc_node(size
, gfp
, node
);
3495 if (pdata
->ptrs
[cpu
])
3496 memset(pdata
->ptrs
[cpu
], 0, size
);
3498 pdata
->ptrs
[cpu
] = kzalloc(size
, gfp
);
3499 return pdata
->ptrs
[cpu
];
3501 EXPORT_SYMBOL_GPL(percpu_populate
);
3504 * percpu_populate_mask - populate per-cpu data for more cpu's
3505 * @__pdata: per-cpu data to populate further
3506 * @size: size of per-cpu object
3507 * @gfp: may sleep or not etc.
3508 * @mask: populate per-cpu data for cpu's selected through mask bits
3510 * Per-cpu objects are populated with zeroed buffers.
3512 int __percpu_populate_mask(void *__pdata
, size_t size
, gfp_t gfp
,
3515 cpumask_t populated
= CPU_MASK_NONE
;
3518 for_each_cpu_mask(cpu
, *mask
)
3519 if (unlikely(!percpu_populate(__pdata
, size
, gfp
, cpu
))) {
3520 __percpu_depopulate_mask(__pdata
, &populated
);
3523 cpu_set(cpu
, populated
);
3526 EXPORT_SYMBOL_GPL(__percpu_populate_mask
);
3529 * percpu_alloc_mask - initial setup of per-cpu data
3530 * @size: size of per-cpu object
3531 * @gfp: may sleep or not etc.
3532 * @mask: populate per-data for cpu's selected through mask bits
3534 * Populating per-cpu data for all online cpu's would be a typical use case,
3535 * which is simplified by the percpu_alloc() wrapper.
3536 * Per-cpu objects are populated with zeroed buffers.
3538 void *__percpu_alloc_mask(size_t size
, gfp_t gfp
, cpumask_t
*mask
)
3540 void *pdata
= kzalloc(sizeof(struct percpu_data
), gfp
);
3541 void *__pdata
= __percpu_disguise(pdata
);
3543 if (unlikely(!pdata
))
3545 if (likely(!__percpu_populate_mask(__pdata
, size
, gfp
, mask
)))
3550 EXPORT_SYMBOL_GPL(__percpu_alloc_mask
);
3553 * percpu_free - final cleanup of per-cpu data
3554 * @__pdata: object to clean up
3556 * We simply clean up any per-cpu object left. No need for the client to
3557 * track and specify through a bis mask which per-cpu objects are to free.
3559 void percpu_free(void *__pdata
)
3561 __percpu_depopulate_mask(__pdata
, &cpu_possible_map
);
3562 kfree(__percpu_disguise(__pdata
));
3564 EXPORT_SYMBOL_GPL(percpu_free
);
3565 #endif /* CONFIG_SMP */
3568 * kmem_cache_free - Deallocate an object
3569 * @cachep: The cache the allocation was from.
3570 * @objp: The previously allocated object.
3572 * Free an object which was previously allocated from this
3575 void kmem_cache_free(struct kmem_cache
*cachep
, void *objp
)
3577 unsigned long flags
;
3579 BUG_ON(virt_to_cache(objp
) != cachep
);
3581 local_irq_save(flags
);
3582 __cache_free(cachep
, objp
);
3583 local_irq_restore(flags
);
3585 EXPORT_SYMBOL(kmem_cache_free
);
3588 * kfree - free previously allocated memory
3589 * @objp: pointer returned by kmalloc.
3591 * If @objp is NULL, no operation is performed.
3593 * Don't free memory not originally allocated by kmalloc()
3594 * or you will run into trouble.
3596 void kfree(const void *objp
)
3598 struct kmem_cache
*c
;
3599 unsigned long flags
;
3601 if (unlikely(!objp
))
3603 local_irq_save(flags
);
3604 kfree_debugcheck(objp
);
3605 c
= virt_to_cache(objp
);
3606 debug_check_no_locks_freed(objp
, obj_size(c
));
3607 __cache_free(c
, (void *)objp
);
3608 local_irq_restore(flags
);
3610 EXPORT_SYMBOL(kfree
);
3612 unsigned int kmem_cache_size(struct kmem_cache
*cachep
)
3614 return obj_size(cachep
);
3616 EXPORT_SYMBOL(kmem_cache_size
);
3618 const char *kmem_cache_name(struct kmem_cache
*cachep
)
3620 return cachep
->name
;
3622 EXPORT_SYMBOL_GPL(kmem_cache_name
);
3625 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3627 static int alloc_kmemlist(struct kmem_cache
*cachep
)
3630 struct kmem_list3
*l3
;
3631 struct array_cache
*new_shared
;
3632 struct array_cache
**new_alien
;
3634 for_each_online_node(node
) {
3636 new_alien
= alloc_alien_cache(node
, cachep
->limit
);
3640 new_shared
= alloc_arraycache(node
,
3641 cachep
->shared
*cachep
->batchcount
,
3644 free_alien_cache(new_alien
);
3648 l3
= cachep
->nodelists
[node
];
3650 struct array_cache
*shared
= l3
->shared
;
3652 spin_lock_irq(&l3
->list_lock
);
3655 free_block(cachep
, shared
->entry
,
3656 shared
->avail
, node
);
3658 l3
->shared
= new_shared
;
3660 l3
->alien
= new_alien
;
3663 l3
->free_limit
= (1 + nr_cpus_node(node
)) *
3664 cachep
->batchcount
+ cachep
->num
;
3665 spin_unlock_irq(&l3
->list_lock
);
3667 free_alien_cache(new_alien
);
3670 l3
= kmalloc_node(sizeof(struct kmem_list3
), GFP_KERNEL
, node
);
3672 free_alien_cache(new_alien
);
3677 kmem_list3_init(l3
);
3678 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
+
3679 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
3680 l3
->shared
= new_shared
;
3681 l3
->alien
= new_alien
;
3682 l3
->free_limit
= (1 + nr_cpus_node(node
)) *
3683 cachep
->batchcount
+ cachep
->num
;
3684 cachep
->nodelists
[node
] = l3
;
3689 if (!cachep
->next
.next
) {
3690 /* Cache is not active yet. Roll back what we did */
3693 if (cachep
->nodelists
[node
]) {
3694 l3
= cachep
->nodelists
[node
];
3697 free_alien_cache(l3
->alien
);
3699 cachep
->nodelists
[node
] = NULL
;
3707 struct ccupdate_struct
{
3708 struct kmem_cache
*cachep
;
3709 struct array_cache
*new[NR_CPUS
];
3712 static void do_ccupdate_local(void *info
)
3714 struct ccupdate_struct
*new = info
;
3715 struct array_cache
*old
;
3718 old
= cpu_cache_get(new->cachep
);
3720 new->cachep
->array
[smp_processor_id()] = new->new[smp_processor_id()];
3721 new->new[smp_processor_id()] = old
;
3724 /* Always called with the cache_chain_mutex held */
3725 static int do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3726 int batchcount
, int shared
)
3728 struct ccupdate_struct
new;
3731 memset(&new.new, 0, sizeof(new.new));
3732 for_each_online_cpu(i
) {
3733 new.new[i
] = alloc_arraycache(cpu_to_node(i
), limit
,
3736 for (i
--; i
>= 0; i
--)
3741 new.cachep
= cachep
;
3743 on_each_cpu(do_ccupdate_local
, (void *)&new, 1, 1);
3746 cachep
->batchcount
= batchcount
;
3747 cachep
->limit
= limit
;
3748 cachep
->shared
= shared
;
3750 for_each_online_cpu(i
) {
3751 struct array_cache
*ccold
= new.new[i
];
3754 spin_lock_irq(&cachep
->nodelists
[cpu_to_node(i
)]->list_lock
);
3755 free_block(cachep
, ccold
->entry
, ccold
->avail
, cpu_to_node(i
));
3756 spin_unlock_irq(&cachep
->nodelists
[cpu_to_node(i
)]->list_lock
);
3760 return alloc_kmemlist(cachep
);
3763 /* Called with cache_chain_mutex held always */
3764 static int enable_cpucache(struct kmem_cache
*cachep
)
3770 * The head array serves three purposes:
3771 * - create a LIFO ordering, i.e. return objects that are cache-warm
3772 * - reduce the number of spinlock operations.
3773 * - reduce the number of linked list operations on the slab and
3774 * bufctl chains: array operations are cheaper.
3775 * The numbers are guessed, we should auto-tune as described by
3778 if (cachep
->buffer_size
> 131072)
3780 else if (cachep
->buffer_size
> PAGE_SIZE
)
3782 else if (cachep
->buffer_size
> 1024)
3784 else if (cachep
->buffer_size
> 256)
3790 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3791 * allocation behaviour: Most allocs on one cpu, most free operations
3792 * on another cpu. For these cases, an efficient object passing between
3793 * cpus is necessary. This is provided by a shared array. The array
3794 * replaces Bonwick's magazine layer.
3795 * On uniprocessor, it's functionally equivalent (but less efficient)
3796 * to a larger limit. Thus disabled by default.
3800 if (cachep
->buffer_size
<= PAGE_SIZE
)
3806 * With debugging enabled, large batchcount lead to excessively long
3807 * periods with disabled local interrupts. Limit the batchcount
3812 err
= do_tune_cpucache(cachep
, limit
, (limit
+ 1) / 2, shared
);
3814 printk(KERN_ERR
"enable_cpucache failed for %s, error %d.\n",
3815 cachep
->name
, -err
);
3820 * Drain an array if it contains any elements taking the l3 lock only if
3821 * necessary. Note that the l3 listlock also protects the array_cache
3822 * if drain_array() is used on the shared array.
3824 void drain_array(struct kmem_cache
*cachep
, struct kmem_list3
*l3
,
3825 struct array_cache
*ac
, int force
, int node
)
3829 if (!ac
|| !ac
->avail
)
3831 if (ac
->touched
&& !force
) {
3834 spin_lock_irq(&l3
->list_lock
);
3836 tofree
= force
? ac
->avail
: (ac
->limit
+ 4) / 5;
3837 if (tofree
> ac
->avail
)
3838 tofree
= (ac
->avail
+ 1) / 2;
3839 free_block(cachep
, ac
->entry
, tofree
, node
);
3840 ac
->avail
-= tofree
;
3841 memmove(ac
->entry
, &(ac
->entry
[tofree
]),
3842 sizeof(void *) * ac
->avail
);
3844 spin_unlock_irq(&l3
->list_lock
);
3849 * cache_reap - Reclaim memory from caches.
3850 * @unused: unused parameter
3852 * Called from workqueue/eventd every few seconds.
3854 * - clear the per-cpu caches for this CPU.
3855 * - return freeable pages to the main free memory pool.
3857 * If we cannot acquire the cache chain mutex then just give up - we'll try
3858 * again on the next iteration.
3860 static void cache_reap(void *unused
)
3862 struct kmem_cache
*searchp
;
3863 struct kmem_list3
*l3
;
3864 int node
= numa_node_id();
3866 if (!mutex_trylock(&cache_chain_mutex
)) {
3867 /* Give up. Setup the next iteration. */
3868 schedule_delayed_work(&__get_cpu_var(reap_work
),
3873 list_for_each_entry(searchp
, &cache_chain
, next
) {
3877 * We only take the l3 lock if absolutely necessary and we
3878 * have established with reasonable certainty that
3879 * we can do some work if the lock was obtained.
3881 l3
= searchp
->nodelists
[node
];
3883 reap_alien(searchp
, l3
);
3885 drain_array(searchp
, l3
, cpu_cache_get(searchp
), 0, node
);
3888 * These are racy checks but it does not matter
3889 * if we skip one check or scan twice.
3891 if (time_after(l3
->next_reap
, jiffies
))
3894 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
;
3896 drain_array(searchp
, l3
, l3
->shared
, 0, node
);
3898 if (l3
->free_touched
)
3899 l3
->free_touched
= 0;
3903 freed
= drain_freelist(searchp
, l3
, (l3
->free_limit
+
3904 5 * searchp
->num
- 1) / (5 * searchp
->num
));
3905 STATS_ADD_REAPED(searchp
, freed
);
3911 mutex_unlock(&cache_chain_mutex
);
3913 refresh_cpu_vm_stats(smp_processor_id());
3914 /* Set up the next iteration */
3915 schedule_delayed_work(&__get_cpu_var(reap_work
), REAPTIMEOUT_CPUC
);
3918 #ifdef CONFIG_PROC_FS
3920 static void print_slabinfo_header(struct seq_file
*m
)
3923 * Output format version, so at least we can change it
3924 * without _too_ many complaints.
3927 seq_puts(m
, "slabinfo - version: 2.1 (statistics)\n");
3929 seq_puts(m
, "slabinfo - version: 2.1\n");
3931 seq_puts(m
, "# name <active_objs> <num_objs> <objsize> "
3932 "<objperslab> <pagesperslab>");
3933 seq_puts(m
, " : tunables <limit> <batchcount> <sharedfactor>");
3934 seq_puts(m
, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
3936 seq_puts(m
, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
3937 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
3938 seq_puts(m
, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
3943 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
3946 struct list_head
*p
;
3948 mutex_lock(&cache_chain_mutex
);
3950 print_slabinfo_header(m
);
3951 p
= cache_chain
.next
;
3954 if (p
== &cache_chain
)
3957 return list_entry(p
, struct kmem_cache
, next
);
3960 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
3962 struct kmem_cache
*cachep
= p
;
3964 return cachep
->next
.next
== &cache_chain
?
3965 NULL
: list_entry(cachep
->next
.next
, struct kmem_cache
, next
);
3968 static void s_stop(struct seq_file
*m
, void *p
)
3970 mutex_unlock(&cache_chain_mutex
);
3973 static int s_show(struct seq_file
*m
, void *p
)
3975 struct kmem_cache
*cachep
= p
;
3977 unsigned long active_objs
;
3978 unsigned long num_objs
;
3979 unsigned long active_slabs
= 0;
3980 unsigned long num_slabs
, free_objects
= 0, shared_avail
= 0;
3984 struct kmem_list3
*l3
;
3988 for_each_online_node(node
) {
3989 l3
= cachep
->nodelists
[node
];
3994 spin_lock_irq(&l3
->list_lock
);
3996 list_for_each_entry(slabp
, &l3
->slabs_full
, list
) {
3997 if (slabp
->inuse
!= cachep
->num
&& !error
)
3998 error
= "slabs_full accounting error";
3999 active_objs
+= cachep
->num
;
4002 list_for_each_entry(slabp
, &l3
->slabs_partial
, list
) {
4003 if (slabp
->inuse
== cachep
->num
&& !error
)
4004 error
= "slabs_partial inuse accounting error";
4005 if (!slabp
->inuse
&& !error
)
4006 error
= "slabs_partial/inuse accounting error";
4007 active_objs
+= slabp
->inuse
;
4010 list_for_each_entry(slabp
, &l3
->slabs_free
, list
) {
4011 if (slabp
->inuse
&& !error
)
4012 error
= "slabs_free/inuse accounting error";
4015 free_objects
+= l3
->free_objects
;
4017 shared_avail
+= l3
->shared
->avail
;
4019 spin_unlock_irq(&l3
->list_lock
);
4021 num_slabs
+= active_slabs
;
4022 num_objs
= num_slabs
* cachep
->num
;
4023 if (num_objs
- active_objs
!= free_objects
&& !error
)
4024 error
= "free_objects accounting error";
4026 name
= cachep
->name
;
4028 printk(KERN_ERR
"slab: cache %s error: %s\n", name
, error
);
4030 seq_printf(m
, "%-17s %6lu %6lu %6u %4u %4d",
4031 name
, active_objs
, num_objs
, cachep
->buffer_size
,
4032 cachep
->num
, (1 << cachep
->gfporder
));
4033 seq_printf(m
, " : tunables %4u %4u %4u",
4034 cachep
->limit
, cachep
->batchcount
, cachep
->shared
);
4035 seq_printf(m
, " : slabdata %6lu %6lu %6lu",
4036 active_slabs
, num_slabs
, shared_avail
);
4039 unsigned long high
= cachep
->high_mark
;
4040 unsigned long allocs
= cachep
->num_allocations
;
4041 unsigned long grown
= cachep
->grown
;
4042 unsigned long reaped
= cachep
->reaped
;
4043 unsigned long errors
= cachep
->errors
;
4044 unsigned long max_freeable
= cachep
->max_freeable
;
4045 unsigned long node_allocs
= cachep
->node_allocs
;
4046 unsigned long node_frees
= cachep
->node_frees
;
4047 unsigned long overflows
= cachep
->node_overflow
;
4049 seq_printf(m
, " : globalstat %7lu %6lu %5lu %4lu \
4050 %4lu %4lu %4lu %4lu %4lu", allocs
, high
, grown
,
4051 reaped
, errors
, max_freeable
, node_allocs
,
4052 node_frees
, overflows
);
4056 unsigned long allochit
= atomic_read(&cachep
->allochit
);
4057 unsigned long allocmiss
= atomic_read(&cachep
->allocmiss
);
4058 unsigned long freehit
= atomic_read(&cachep
->freehit
);
4059 unsigned long freemiss
= atomic_read(&cachep
->freemiss
);
4061 seq_printf(m
, " : cpustat %6lu %6lu %6lu %6lu",
4062 allochit
, allocmiss
, freehit
, freemiss
);
4070 * slabinfo_op - iterator that generates /proc/slabinfo
4079 * num-pages-per-slab
4080 * + further values on SMP and with statistics enabled
4083 struct seq_operations slabinfo_op
= {
4090 #define MAX_SLABINFO_WRITE 128
4092 * slabinfo_write - Tuning for the slab allocator
4094 * @buffer: user buffer
4095 * @count: data length
4098 ssize_t
slabinfo_write(struct file
*file
, const char __user
* buffer
,
4099 size_t count
, loff_t
*ppos
)
4101 char kbuf
[MAX_SLABINFO_WRITE
+ 1], *tmp
;
4102 int limit
, batchcount
, shared
, res
;
4103 struct kmem_cache
*cachep
;
4105 if (count
> MAX_SLABINFO_WRITE
)
4107 if (copy_from_user(&kbuf
, buffer
, count
))
4109 kbuf
[MAX_SLABINFO_WRITE
] = '\0';
4111 tmp
= strchr(kbuf
, ' ');
4116 if (sscanf(tmp
, " %d %d %d", &limit
, &batchcount
, &shared
) != 3)
4119 /* Find the cache in the chain of caches. */
4120 mutex_lock(&cache_chain_mutex
);
4122 list_for_each_entry(cachep
, &cache_chain
, next
) {
4123 if (!strcmp(cachep
->name
, kbuf
)) {
4124 if (limit
< 1 || batchcount
< 1 ||
4125 batchcount
> limit
|| shared
< 0) {
4128 res
= do_tune_cpucache(cachep
, limit
,
4129 batchcount
, shared
);
4134 mutex_unlock(&cache_chain_mutex
);
4140 #ifdef CONFIG_DEBUG_SLAB_LEAK
4142 static void *leaks_start(struct seq_file
*m
, loff_t
*pos
)
4145 struct list_head
*p
;
4147 mutex_lock(&cache_chain_mutex
);
4148 p
= cache_chain
.next
;
4151 if (p
== &cache_chain
)
4154 return list_entry(p
, struct kmem_cache
, next
);
4157 static inline int add_caller(unsigned long *n
, unsigned long v
)
4167 unsigned long *q
= p
+ 2 * i
;
4181 memmove(p
+ 2, p
, n
[1] * 2 * sizeof(unsigned long) - ((void *)p
- (void *)n
));
4187 static void handle_slab(unsigned long *n
, struct kmem_cache
*c
, struct slab
*s
)
4193 for (i
= 0, p
= s
->s_mem
; i
< c
->num
; i
++, p
+= c
->buffer_size
) {
4194 if (slab_bufctl(s
)[i
] != BUFCTL_ACTIVE
)
4196 if (!add_caller(n
, (unsigned long)*dbg_userword(c
, p
)))
4201 static void show_symbol(struct seq_file
*m
, unsigned long address
)
4203 #ifdef CONFIG_KALLSYMS
4206 unsigned long offset
, size
;
4207 char namebuf
[KSYM_NAME_LEN
+1];
4209 name
= kallsyms_lookup(address
, &size
, &offset
, &modname
, namebuf
);
4212 seq_printf(m
, "%s+%#lx/%#lx", name
, offset
, size
);
4214 seq_printf(m
, " [%s]", modname
);
4218 seq_printf(m
, "%p", (void *)address
);
4221 static int leaks_show(struct seq_file
*m
, void *p
)
4223 struct kmem_cache
*cachep
= p
;
4225 struct kmem_list3
*l3
;
4227 unsigned long *n
= m
->private;
4231 if (!(cachep
->flags
& SLAB_STORE_USER
))
4233 if (!(cachep
->flags
& SLAB_RED_ZONE
))
4236 /* OK, we can do it */
4240 for_each_online_node(node
) {
4241 l3
= cachep
->nodelists
[node
];
4246 spin_lock_irq(&l3
->list_lock
);
4248 list_for_each_entry(slabp
, &l3
->slabs_full
, list
)
4249 handle_slab(n
, cachep
, slabp
);
4250 list_for_each_entry(slabp
, &l3
->slabs_partial
, list
)
4251 handle_slab(n
, cachep
, slabp
);
4252 spin_unlock_irq(&l3
->list_lock
);
4254 name
= cachep
->name
;
4256 /* Increase the buffer size */
4257 mutex_unlock(&cache_chain_mutex
);
4258 m
->private = kzalloc(n
[0] * 4 * sizeof(unsigned long), GFP_KERNEL
);
4260 /* Too bad, we are really out */
4262 mutex_lock(&cache_chain_mutex
);
4265 *(unsigned long *)m
->private = n
[0] * 2;
4267 mutex_lock(&cache_chain_mutex
);
4268 /* Now make sure this entry will be retried */
4272 for (i
= 0; i
< n
[1]; i
++) {
4273 seq_printf(m
, "%s: %lu ", name
, n
[2*i
+3]);
4274 show_symbol(m
, n
[2*i
+2]);
4280 struct seq_operations slabstats_op
= {
4281 .start
= leaks_start
,
4290 * ksize - get the actual amount of memory allocated for a given object
4291 * @objp: Pointer to the object
4293 * kmalloc may internally round up allocations and return more memory
4294 * than requested. ksize() can be used to determine the actual amount of
4295 * memory allocated. The caller may use this additional memory, even though
4296 * a smaller amount of memory was initially specified with the kmalloc call.
4297 * The caller must guarantee that objp points to a valid object previously
4298 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4299 * must not be freed during the duration of the call.
4301 unsigned int ksize(const void *objp
)
4303 if (unlikely(objp
== NULL
))
4306 return obj_size(virt_to_cache(objp
));