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/swap.h>
93 #include <linux/cache.h>
94 #include <linux/interrupt.h>
95 #include <linux/init.h>
96 #include <linux/compiler.h>
97 #include <linux/cpuset.h>
98 #include <linux/seq_file.h>
99 #include <linux/notifier.h>
100 #include <linux/kallsyms.h>
101 #include <linux/cpu.h>
102 #include <linux/sysctl.h>
103 #include <linux/module.h>
104 #include <linux/rcupdate.h>
105 #include <linux/string.h>
106 #include <linux/nodemask.h>
107 #include <linux/mempolicy.h>
108 #include <linux/mutex.h>
110 #include <asm/uaccess.h>
111 #include <asm/cacheflush.h>
112 #include <asm/tlbflush.h>
113 #include <asm/page.h>
116 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
117 * SLAB_RED_ZONE & SLAB_POISON.
118 * 0 for faster, smaller code (especially in the critical paths).
120 * STATS - 1 to collect stats for /proc/slabinfo.
121 * 0 for faster, smaller code (especially in the critical paths).
123 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
126 #ifdef CONFIG_DEBUG_SLAB
129 #define FORCED_DEBUG 1
133 #define FORCED_DEBUG 0
136 /* Shouldn't this be in a header file somewhere? */
137 #define BYTES_PER_WORD sizeof(void *)
139 #ifndef cache_line_size
140 #define cache_line_size() L1_CACHE_BYTES
143 #ifndef ARCH_KMALLOC_MINALIGN
145 * Enforce a minimum alignment for the kmalloc caches.
146 * Usually, the kmalloc caches are cache_line_size() aligned, except when
147 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
148 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
149 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
150 * Note that this flag disables some debug features.
152 #define ARCH_KMALLOC_MINALIGN 0
155 #ifndef ARCH_SLAB_MINALIGN
157 * Enforce a minimum alignment for all caches.
158 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
159 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
160 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
161 * some debug features.
163 #define ARCH_SLAB_MINALIGN 0
166 #ifndef ARCH_KMALLOC_FLAGS
167 #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
170 /* Legal flag mask for kmem_cache_create(). */
172 # define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
173 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
175 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
176 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
177 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
179 # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
180 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
181 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
182 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
188 * Bufctl's are used for linking objs within a slab
191 * This implementation relies on "struct page" for locating the cache &
192 * slab an object belongs to.
193 * This allows the bufctl structure to be small (one int), but limits
194 * the number of objects a slab (not a cache) can contain when off-slab
195 * bufctls are used. The limit is the size of the largest general cache
196 * that does not use off-slab slabs.
197 * For 32bit archs with 4 kB pages, is this 56.
198 * This is not serious, as it is only for large objects, when it is unwise
199 * to have too many per slab.
200 * Note: This limit can be raised by introducing a general cache whose size
201 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
204 typedef unsigned int kmem_bufctl_t
;
205 #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
206 #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
207 #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
208 #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
213 * Manages the objs in a slab. Placed either at the beginning of mem allocated
214 * for a slab, or allocated from an general cache.
215 * Slabs are chained into three list: fully used, partial, fully free slabs.
218 struct list_head list
;
219 unsigned long colouroff
;
220 void *s_mem
; /* including colour offset */
221 unsigned int inuse
; /* num of objs active in slab */
223 unsigned short nodeid
;
229 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
230 * arrange for kmem_freepages to be called via RCU. This is useful if
231 * we need to approach a kernel structure obliquely, from its address
232 * obtained without the usual locking. We can lock the structure to
233 * stabilize it and check it's still at the given address, only if we
234 * can be sure that the memory has not been meanwhile reused for some
235 * other kind of object (which our subsystem's lock might corrupt).
237 * rcu_read_lock before reading the address, then rcu_read_unlock after
238 * taking the spinlock within the structure expected at that address.
240 * We assume struct slab_rcu can overlay struct slab when destroying.
243 struct rcu_head head
;
244 struct kmem_cache
*cachep
;
252 * - LIFO ordering, to hand out cache-warm objects from _alloc
253 * - reduce the number of linked list operations
254 * - reduce spinlock operations
256 * The limit is stored in the per-cpu structure to reduce the data cache
263 unsigned int batchcount
;
264 unsigned int touched
;
267 * Must have this definition in here for the proper
268 * alignment of array_cache. Also simplifies accessing
270 * [0] is for gcc 2.95. It should really be [].
275 * bootstrap: The caches do not work without cpuarrays anymore, but the
276 * cpuarrays are allocated from the generic caches...
278 #define BOOT_CPUCACHE_ENTRIES 1
279 struct arraycache_init
{
280 struct array_cache cache
;
281 void *entries
[BOOT_CPUCACHE_ENTRIES
];
285 * The slab lists for all objects.
288 struct list_head slabs_partial
; /* partial list first, better asm code */
289 struct list_head slabs_full
;
290 struct list_head slabs_free
;
291 unsigned long free_objects
;
292 unsigned int free_limit
;
293 unsigned int colour_next
; /* Per-node cache coloring */
294 spinlock_t list_lock
;
295 struct array_cache
*shared
; /* shared per node */
296 struct array_cache
**alien
; /* on other nodes */
297 unsigned long next_reap
; /* updated without locking */
298 int free_touched
; /* updated without locking */
302 * Need this for bootstrapping a per node allocator.
304 #define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
305 struct kmem_list3 __initdata initkmem_list3
[NUM_INIT_LISTS
];
306 #define CACHE_CACHE 0
308 #define SIZE_L3 (1 + MAX_NUMNODES)
311 * This function must be completely optimized away if a constant is passed to
312 * it. Mostly the same as what is in linux/slab.h except it returns an index.
314 static __always_inline
int index_of(const size_t size
)
316 extern void __bad_size(void);
318 if (__builtin_constant_p(size
)) {
326 #include "linux/kmalloc_sizes.h"
334 #define INDEX_AC index_of(sizeof(struct arraycache_init))
335 #define INDEX_L3 index_of(sizeof(struct kmem_list3))
337 static void kmem_list3_init(struct kmem_list3
*parent
)
339 INIT_LIST_HEAD(&parent
->slabs_full
);
340 INIT_LIST_HEAD(&parent
->slabs_partial
);
341 INIT_LIST_HEAD(&parent
->slabs_free
);
342 parent
->shared
= NULL
;
343 parent
->alien
= NULL
;
344 parent
->colour_next
= 0;
345 spin_lock_init(&parent
->list_lock
);
346 parent
->free_objects
= 0;
347 parent
->free_touched
= 0;
350 #define MAKE_LIST(cachep, listp, slab, nodeid) \
352 INIT_LIST_HEAD(listp); \
353 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
356 #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
358 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
359 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
360 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
370 /* 1) per-cpu data, touched during every alloc/free */
371 struct array_cache
*array
[NR_CPUS
];
372 /* 2) Cache tunables. Protected by cache_chain_mutex */
373 unsigned int batchcount
;
377 unsigned int buffer_size
;
378 /* 3) touched by every alloc & free from the backend */
379 struct kmem_list3
*nodelists
[MAX_NUMNODES
];
381 unsigned int flags
; /* constant flags */
382 unsigned int num
; /* # of objs per slab */
384 /* 4) cache_grow/shrink */
385 /* order of pgs per slab (2^n) */
386 unsigned int gfporder
;
388 /* force GFP flags, e.g. GFP_DMA */
391 size_t colour
; /* cache colouring range */
392 unsigned int colour_off
; /* colour offset */
393 struct kmem_cache
*slabp_cache
;
394 unsigned int slab_size
;
395 unsigned int dflags
; /* dynamic flags */
397 /* constructor func */
398 void (*ctor
) (void *, struct kmem_cache
*, unsigned long);
400 /* de-constructor func */
401 void (*dtor
) (void *, struct kmem_cache
*, unsigned long);
403 /* 5) cache creation/removal */
405 struct list_head next
;
409 unsigned long num_active
;
410 unsigned long num_allocations
;
411 unsigned long high_mark
;
413 unsigned long reaped
;
414 unsigned long errors
;
415 unsigned long max_freeable
;
416 unsigned long node_allocs
;
417 unsigned long node_frees
;
418 unsigned long node_overflow
;
426 * If debugging is enabled, then the allocator can add additional
427 * fields and/or padding to every object. buffer_size contains the total
428 * object size including these internal fields, the following two
429 * variables contain the offset to the user object and its size.
436 #define CFLGS_OFF_SLAB (0x80000000UL)
437 #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
439 #define BATCHREFILL_LIMIT 16
441 * Optimization question: fewer reaps means less probability for unnessary
442 * cpucache drain/refill cycles.
444 * OTOH the cpuarrays can contain lots of objects,
445 * which could lock up otherwise freeable slabs.
447 #define REAPTIMEOUT_CPUC (2*HZ)
448 #define REAPTIMEOUT_LIST3 (4*HZ)
451 #define STATS_INC_ACTIVE(x) ((x)->num_active++)
452 #define STATS_DEC_ACTIVE(x) ((x)->num_active--)
453 #define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
454 #define STATS_INC_GROWN(x) ((x)->grown++)
455 #define STATS_INC_REAPED(x) ((x)->reaped++)
456 #define STATS_SET_HIGH(x) \
458 if ((x)->num_active > (x)->high_mark) \
459 (x)->high_mark = (x)->num_active; \
461 #define STATS_INC_ERR(x) ((x)->errors++)
462 #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
463 #define STATS_INC_NODEFREES(x) ((x)->node_frees++)
464 #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
465 #define STATS_SET_FREEABLE(x, i) \
467 if ((x)->max_freeable < i) \
468 (x)->max_freeable = i; \
470 #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
471 #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
472 #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
473 #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
475 #define STATS_INC_ACTIVE(x) do { } while (0)
476 #define STATS_DEC_ACTIVE(x) do { } while (0)
477 #define STATS_INC_ALLOCED(x) do { } while (0)
478 #define STATS_INC_GROWN(x) do { } while (0)
479 #define STATS_INC_REAPED(x) do { } while (0)
480 #define STATS_SET_HIGH(x) do { } while (0)
481 #define STATS_INC_ERR(x) do { } while (0)
482 #define STATS_INC_NODEALLOCS(x) do { } while (0)
483 #define STATS_INC_NODEFREES(x) do { } while (0)
484 #define STATS_INC_ACOVERFLOW(x) do { } while (0)
485 #define STATS_SET_FREEABLE(x, i) do { } while (0)
486 #define STATS_INC_ALLOCHIT(x) do { } while (0)
487 #define STATS_INC_ALLOCMISS(x) do { } while (0)
488 #define STATS_INC_FREEHIT(x) do { } while (0)
489 #define STATS_INC_FREEMISS(x) do { } while (0)
494 * Magic nums for obj red zoning.
495 * Placed in the first word before and the first word after an obj.
497 #define RED_INACTIVE 0x5A2CF071UL /* when obj is inactive */
498 #define RED_ACTIVE 0x170FC2A5UL /* when obj is active */
500 /* ...and for poisoning */
501 #define POISON_INUSE 0x5a /* for use-uninitialised poisoning */
502 #define POISON_FREE 0x6b /* for use-after-free poisoning */
503 #define POISON_END 0xa5 /* end-byte of poisoning */
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 return (struct kmem_cache
*)page
->lru
.next
;
598 static inline void page_set_slab(struct page
*page
, struct slab
*slab
)
600 page
->lru
.prev
= (struct list_head
*)slab
;
603 static inline struct slab
*page_get_slab(struct page
*page
)
605 if (unlikely(PageCompound(page
)))
606 page
= (struct page
*)page_private(page
);
607 return (struct slab
*)page
->lru
.prev
;
610 static inline struct kmem_cache
*virt_to_cache(const void *obj
)
612 struct page
*page
= virt_to_page(obj
);
613 return page_get_cache(page
);
616 static inline struct slab
*virt_to_slab(const void *obj
)
618 struct page
*page
= virt_to_page(obj
);
619 return page_get_slab(page
);
622 static inline void *index_to_obj(struct kmem_cache
*cache
, struct slab
*slab
,
625 return slab
->s_mem
+ cache
->buffer_size
* idx
;
628 static inline unsigned int obj_to_index(struct kmem_cache
*cache
,
629 struct slab
*slab
, void *obj
)
631 return (unsigned)(obj
- slab
->s_mem
) / cache
->buffer_size
;
635 * These are the default caches for kmalloc. Custom caches can have other sizes.
637 struct cache_sizes malloc_sizes
[] = {
638 #define CACHE(x) { .cs_size = (x) },
639 #include <linux/kmalloc_sizes.h>
643 EXPORT_SYMBOL(malloc_sizes
);
645 /* Must match cache_sizes above. Out of line to keep cache footprint low. */
651 static struct cache_names __initdata cache_names
[] = {
652 #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
653 #include <linux/kmalloc_sizes.h>
658 static struct arraycache_init initarray_cache __initdata
=
659 { {0, BOOT_CPUCACHE_ENTRIES
, 1, 0} };
660 static struct arraycache_init initarray_generic
=
661 { {0, BOOT_CPUCACHE_ENTRIES
, 1, 0} };
663 /* internal cache of cache description objs */
664 static struct kmem_cache cache_cache
= {
666 .limit
= BOOT_CPUCACHE_ENTRIES
,
668 .buffer_size
= sizeof(struct kmem_cache
),
669 .name
= "kmem_cache",
671 .obj_size
= sizeof(struct kmem_cache
),
675 /* Guard access to the cache-chain. */
676 static DEFINE_MUTEX(cache_chain_mutex
);
677 static struct list_head cache_chain
;
680 * vm_enough_memory() looks at this to determine how many slab-allocated pages
681 * are possibly freeable under pressure
683 * SLAB_RECLAIM_ACCOUNT turns this on per-slab
685 atomic_t slab_reclaim_pages
;
688 * chicken and egg problem: delay the per-cpu array allocation
689 * until the general caches are up.
699 * used by boot code to determine if it can use slab based allocator
701 int slab_is_available(void)
703 return g_cpucache_up
== FULL
;
706 static DEFINE_PER_CPU(struct work_struct
, reap_work
);
708 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int len
,
710 static void enable_cpucache(struct kmem_cache
*cachep
);
711 static void cache_reap(void *unused
);
712 static int __node_shrink(struct kmem_cache
*cachep
, int node
);
714 static inline struct array_cache
*cpu_cache_get(struct kmem_cache
*cachep
)
716 return cachep
->array
[smp_processor_id()];
719 static inline struct kmem_cache
*__find_general_cachep(size_t size
,
722 struct cache_sizes
*csizep
= malloc_sizes
;
725 /* This happens if someone tries to call
726 * kmem_cache_create(), or __kmalloc(), before
727 * the generic caches are initialized.
729 BUG_ON(malloc_sizes
[INDEX_AC
].cs_cachep
== NULL
);
731 while (size
> csizep
->cs_size
)
735 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
736 * has cs_{dma,}cachep==NULL. Thus no special case
737 * for large kmalloc calls required.
739 if (unlikely(gfpflags
& GFP_DMA
))
740 return csizep
->cs_dmacachep
;
741 return csizep
->cs_cachep
;
744 struct kmem_cache
*kmem_find_general_cachep(size_t size
, gfp_t gfpflags
)
746 return __find_general_cachep(size
, gfpflags
);
748 EXPORT_SYMBOL(kmem_find_general_cachep
);
750 static size_t slab_mgmt_size(size_t nr_objs
, size_t align
)
752 return ALIGN(sizeof(struct slab
)+nr_objs
*sizeof(kmem_bufctl_t
), align
);
756 * Calculate the number of objects and left-over bytes for a given buffer size.
758 static void cache_estimate(unsigned long gfporder
, size_t buffer_size
,
759 size_t align
, int flags
, size_t *left_over
,
764 size_t slab_size
= PAGE_SIZE
<< gfporder
;
767 * The slab management structure can be either off the slab or
768 * on it. For the latter case, the memory allocated for a
772 * - One kmem_bufctl_t for each object
773 * - Padding to respect alignment of @align
774 * - @buffer_size bytes for each object
776 * If the slab management structure is off the slab, then the
777 * alignment will already be calculated into the size. Because
778 * the slabs are all pages aligned, the objects will be at the
779 * correct alignment when allocated.
781 if (flags
& CFLGS_OFF_SLAB
) {
783 nr_objs
= slab_size
/ buffer_size
;
785 if (nr_objs
> SLAB_LIMIT
)
786 nr_objs
= SLAB_LIMIT
;
789 * Ignore padding for the initial guess. The padding
790 * is at most @align-1 bytes, and @buffer_size is at
791 * least @align. In the worst case, this result will
792 * be one greater than the number of objects that fit
793 * into the memory allocation when taking the padding
796 nr_objs
= (slab_size
- sizeof(struct slab
)) /
797 (buffer_size
+ sizeof(kmem_bufctl_t
));
800 * This calculated number will be either the right
801 * amount, or one greater than what we want.
803 if (slab_mgmt_size(nr_objs
, align
) + nr_objs
*buffer_size
807 if (nr_objs
> SLAB_LIMIT
)
808 nr_objs
= SLAB_LIMIT
;
810 mgmt_size
= slab_mgmt_size(nr_objs
, align
);
813 *left_over
= slab_size
- nr_objs
*buffer_size
- mgmt_size
;
816 #define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
818 static void __slab_error(const char *function
, struct kmem_cache
*cachep
,
821 printk(KERN_ERR
"slab error in %s(): cache `%s': %s\n",
822 function
, cachep
->name
, msg
);
828 * Special reaping functions for NUMA systems called from cache_reap().
829 * These take care of doing round robin flushing of alien caches (containing
830 * objects freed on different nodes from which they were allocated) and the
831 * flushing of remote pcps by calling drain_node_pages.
833 static DEFINE_PER_CPU(unsigned long, reap_node
);
835 static void init_reap_node(int cpu
)
839 node
= next_node(cpu_to_node(cpu
), node_online_map
);
840 if (node
== MAX_NUMNODES
)
841 node
= first_node(node_online_map
);
843 __get_cpu_var(reap_node
) = node
;
846 static void next_reap_node(void)
848 int node
= __get_cpu_var(reap_node
);
851 * Also drain per cpu pages on remote zones
853 if (node
!= numa_node_id())
854 drain_node_pages(node
);
856 node
= next_node(node
, node_online_map
);
857 if (unlikely(node
>= MAX_NUMNODES
))
858 node
= first_node(node_online_map
);
859 __get_cpu_var(reap_node
) = node
;
863 #define init_reap_node(cpu) do { } while (0)
864 #define next_reap_node(void) do { } while (0)
868 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
869 * via the workqueue/eventd.
870 * Add the CPU number into the expiration time to minimize the possibility of
871 * the CPUs getting into lockstep and contending for the global cache chain
874 static void __devinit
start_cpu_timer(int cpu
)
876 struct work_struct
*reap_work
= &per_cpu(reap_work
, cpu
);
879 * When this gets called from do_initcalls via cpucache_init(),
880 * init_workqueues() has already run, so keventd will be setup
883 if (keventd_up() && reap_work
->func
== NULL
) {
885 INIT_WORK(reap_work
, cache_reap
, NULL
);
886 schedule_delayed_work_on(cpu
, reap_work
, HZ
+ 3 * cpu
);
890 static struct array_cache
*alloc_arraycache(int node
, int entries
,
893 int memsize
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
894 struct array_cache
*nc
= NULL
;
896 nc
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
900 nc
->batchcount
= batchcount
;
902 spin_lock_init(&nc
->lock
);
908 * Transfer objects in one arraycache to another.
909 * Locking must be handled by the caller.
911 * Return the number of entries transferred.
913 static int transfer_objects(struct array_cache
*to
,
914 struct array_cache
*from
, unsigned int max
)
916 /* Figure out how many entries to transfer */
917 int nr
= min(min(from
->avail
, max
), to
->limit
- to
->avail
);
922 memcpy(to
->entry
+ to
->avail
, from
->entry
+ from
->avail
-nr
,
932 static void *__cache_alloc_node(struct kmem_cache
*, gfp_t
, int);
933 static void *alternate_node_alloc(struct kmem_cache
*, gfp_t
);
935 static struct array_cache
**alloc_alien_cache(int node
, int limit
)
937 struct array_cache
**ac_ptr
;
938 int memsize
= sizeof(void *) * MAX_NUMNODES
;
943 ac_ptr
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
946 if (i
== node
|| !node_online(i
)) {
950 ac_ptr
[i
] = alloc_arraycache(node
, limit
, 0xbaadf00d);
952 for (i
--; i
<= 0; i
--)
962 static void free_alien_cache(struct array_cache
**ac_ptr
)
973 static void __drain_alien_cache(struct kmem_cache
*cachep
,
974 struct array_cache
*ac
, int node
)
976 struct kmem_list3
*rl3
= cachep
->nodelists
[node
];
979 spin_lock(&rl3
->list_lock
);
981 * Stuff objects into the remote nodes shared array first.
982 * That way we could avoid the overhead of putting the objects
983 * into the free lists and getting them back later.
986 transfer_objects(rl3
->shared
, ac
, ac
->limit
);
988 free_block(cachep
, ac
->entry
, ac
->avail
, node
);
990 spin_unlock(&rl3
->list_lock
);
995 * Called from cache_reap() to regularly drain alien caches round robin.
997 static void reap_alien(struct kmem_cache
*cachep
, struct kmem_list3
*l3
)
999 int node
= __get_cpu_var(reap_node
);
1002 struct array_cache
*ac
= l3
->alien
[node
];
1004 if (ac
&& ac
->avail
&& spin_trylock_irq(&ac
->lock
)) {
1005 __drain_alien_cache(cachep
, ac
, node
);
1006 spin_unlock_irq(&ac
->lock
);
1011 static void drain_alien_cache(struct kmem_cache
*cachep
,
1012 struct array_cache
**alien
)
1015 struct array_cache
*ac
;
1016 unsigned long flags
;
1018 for_each_online_node(i
) {
1021 spin_lock_irqsave(&ac
->lock
, flags
);
1022 __drain_alien_cache(cachep
, ac
, i
);
1023 spin_unlock_irqrestore(&ac
->lock
, flags
);
1028 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
1030 struct slab
*slabp
= virt_to_slab(objp
);
1031 int nodeid
= slabp
->nodeid
;
1032 struct kmem_list3
*l3
;
1033 struct array_cache
*alien
= NULL
;
1036 * Make sure we are not freeing a object from another node to the array
1037 * cache on this cpu.
1039 if (likely(slabp
->nodeid
== numa_node_id()))
1042 l3
= cachep
->nodelists
[numa_node_id()];
1043 STATS_INC_NODEFREES(cachep
);
1044 if (l3
->alien
&& l3
->alien
[nodeid
]) {
1045 alien
= l3
->alien
[nodeid
];
1046 spin_lock(&alien
->lock
);
1047 if (unlikely(alien
->avail
== alien
->limit
)) {
1048 STATS_INC_ACOVERFLOW(cachep
);
1049 __drain_alien_cache(cachep
, alien
, nodeid
);
1051 alien
->entry
[alien
->avail
++] = objp
;
1052 spin_unlock(&alien
->lock
);
1054 spin_lock(&(cachep
->nodelists
[nodeid
])->list_lock
);
1055 free_block(cachep
, &objp
, 1, nodeid
);
1056 spin_unlock(&(cachep
->nodelists
[nodeid
])->list_lock
);
1063 #define drain_alien_cache(cachep, alien) do { } while (0)
1064 #define reap_alien(cachep, l3) do { } while (0)
1066 static inline struct array_cache
**alloc_alien_cache(int node
, int limit
)
1068 return (struct array_cache
**) 0x01020304ul
;
1071 static inline void free_alien_cache(struct array_cache
**ac_ptr
)
1075 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
1082 static int cpuup_callback(struct notifier_block
*nfb
,
1083 unsigned long action
, void *hcpu
)
1085 long cpu
= (long)hcpu
;
1086 struct kmem_cache
*cachep
;
1087 struct kmem_list3
*l3
= NULL
;
1088 int node
= cpu_to_node(cpu
);
1089 int memsize
= sizeof(struct kmem_list3
);
1092 case CPU_UP_PREPARE
:
1093 mutex_lock(&cache_chain_mutex
);
1095 * We need to do this right in the beginning since
1096 * alloc_arraycache's are going to use this list.
1097 * kmalloc_node allows us to add the slab to the right
1098 * kmem_list3 and not this cpu's kmem_list3
1101 list_for_each_entry(cachep
, &cache_chain
, next
) {
1103 * Set up the size64 kmemlist for cpu before we can
1104 * begin anything. Make sure some other cpu on this
1105 * node has not already allocated this
1107 if (!cachep
->nodelists
[node
]) {
1108 l3
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
1111 kmem_list3_init(l3
);
1112 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
+
1113 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1116 * The l3s don't come and go as CPUs come and
1117 * go. cache_chain_mutex is sufficient
1120 cachep
->nodelists
[node
] = l3
;
1123 spin_lock_irq(&cachep
->nodelists
[node
]->list_lock
);
1124 cachep
->nodelists
[node
]->free_limit
=
1125 (1 + nr_cpus_node(node
)) *
1126 cachep
->batchcount
+ cachep
->num
;
1127 spin_unlock_irq(&cachep
->nodelists
[node
]->list_lock
);
1131 * Now we can go ahead with allocating the shared arrays and
1134 list_for_each_entry(cachep
, &cache_chain
, next
) {
1135 struct array_cache
*nc
;
1136 struct array_cache
*shared
;
1137 struct array_cache
**alien
;
1139 nc
= alloc_arraycache(node
, cachep
->limit
,
1140 cachep
->batchcount
);
1143 shared
= alloc_arraycache(node
,
1144 cachep
->shared
* cachep
->batchcount
,
1149 alien
= alloc_alien_cache(node
, cachep
->limit
);
1152 cachep
->array
[cpu
] = nc
;
1153 l3
= cachep
->nodelists
[node
];
1156 spin_lock_irq(&l3
->list_lock
);
1159 * We are serialised from CPU_DEAD or
1160 * CPU_UP_CANCELLED by the cpucontrol lock
1162 l3
->shared
= shared
;
1171 spin_unlock_irq(&l3
->list_lock
);
1173 free_alien_cache(alien
);
1175 mutex_unlock(&cache_chain_mutex
);
1178 start_cpu_timer(cpu
);
1180 #ifdef CONFIG_HOTPLUG_CPU
1183 * Even if all the cpus of a node are down, we don't free the
1184 * kmem_list3 of any cache. This to avoid a race between
1185 * cpu_down, and a kmalloc allocation from another cpu for
1186 * memory from the node of the cpu going down. The list3
1187 * structure is usually allocated from kmem_cache_create() and
1188 * gets destroyed at kmem_cache_destroy().
1191 case CPU_UP_CANCELED
:
1192 mutex_lock(&cache_chain_mutex
);
1193 list_for_each_entry(cachep
, &cache_chain
, next
) {
1194 struct array_cache
*nc
;
1195 struct array_cache
*shared
;
1196 struct array_cache
**alien
;
1199 mask
= node_to_cpumask(node
);
1200 /* cpu is dead; no one can alloc from it. */
1201 nc
= cachep
->array
[cpu
];
1202 cachep
->array
[cpu
] = NULL
;
1203 l3
= cachep
->nodelists
[node
];
1206 goto free_array_cache
;
1208 spin_lock_irq(&l3
->list_lock
);
1210 /* Free limit for this kmem_list3 */
1211 l3
->free_limit
-= cachep
->batchcount
;
1213 free_block(cachep
, nc
->entry
, nc
->avail
, node
);
1215 if (!cpus_empty(mask
)) {
1216 spin_unlock_irq(&l3
->list_lock
);
1217 goto free_array_cache
;
1220 shared
= l3
->shared
;
1222 free_block(cachep
, l3
->shared
->entry
,
1223 l3
->shared
->avail
, node
);
1230 spin_unlock_irq(&l3
->list_lock
);
1234 drain_alien_cache(cachep
, alien
);
1235 free_alien_cache(alien
);
1241 * In the previous loop, all the objects were freed to
1242 * the respective cache's slabs, now we can go ahead and
1243 * shrink each nodelist to its limit.
1245 list_for_each_entry(cachep
, &cache_chain
, next
) {
1246 l3
= cachep
->nodelists
[node
];
1249 spin_lock_irq(&l3
->list_lock
);
1250 /* free slabs belonging to this node */
1251 __node_shrink(cachep
, node
);
1252 spin_unlock_irq(&l3
->list_lock
);
1254 mutex_unlock(&cache_chain_mutex
);
1260 mutex_unlock(&cache_chain_mutex
);
1264 static struct notifier_block cpucache_notifier
= { &cpuup_callback
, NULL
, 0 };
1267 * swap the static kmem_list3 with kmalloced memory
1269 static void init_list(struct kmem_cache
*cachep
, struct kmem_list3
*list
,
1272 struct kmem_list3
*ptr
;
1274 BUG_ON(cachep
->nodelists
[nodeid
] != list
);
1275 ptr
= kmalloc_node(sizeof(struct kmem_list3
), GFP_KERNEL
, nodeid
);
1278 local_irq_disable();
1279 memcpy(ptr
, list
, sizeof(struct kmem_list3
));
1280 MAKE_ALL_LISTS(cachep
, ptr
, nodeid
);
1281 cachep
->nodelists
[nodeid
] = ptr
;
1286 * Initialisation. Called after the page allocator have been initialised and
1287 * before smp_init().
1289 void __init
kmem_cache_init(void)
1292 struct cache_sizes
*sizes
;
1293 struct cache_names
*names
;
1297 for (i
= 0; i
< NUM_INIT_LISTS
; i
++) {
1298 kmem_list3_init(&initkmem_list3
[i
]);
1299 if (i
< MAX_NUMNODES
)
1300 cache_cache
.nodelists
[i
] = NULL
;
1304 * Fragmentation resistance on low memory - only use bigger
1305 * page orders on machines with more than 32MB of memory.
1307 if (num_physpages
> (32 << 20) >> PAGE_SHIFT
)
1308 slab_break_gfp_order
= BREAK_GFP_ORDER_HI
;
1310 /* Bootstrap is tricky, because several objects are allocated
1311 * from caches that do not exist yet:
1312 * 1) initialize the cache_cache cache: it contains the struct
1313 * kmem_cache structures of all caches, except cache_cache itself:
1314 * cache_cache is statically allocated.
1315 * Initially an __init data area is used for the head array and the
1316 * kmem_list3 structures, it's replaced with a kmalloc allocated
1317 * array at the end of the bootstrap.
1318 * 2) Create the first kmalloc cache.
1319 * The struct kmem_cache for the new cache is allocated normally.
1320 * An __init data area is used for the head array.
1321 * 3) Create the remaining kmalloc caches, with minimally sized
1323 * 4) Replace the __init data head arrays for cache_cache and the first
1324 * kmalloc cache with kmalloc allocated arrays.
1325 * 5) Replace the __init data for kmem_list3 for cache_cache and
1326 * the other cache's with kmalloc allocated memory.
1327 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1330 /* 1) create the cache_cache */
1331 INIT_LIST_HEAD(&cache_chain
);
1332 list_add(&cache_cache
.next
, &cache_chain
);
1333 cache_cache
.colour_off
= cache_line_size();
1334 cache_cache
.array
[smp_processor_id()] = &initarray_cache
.cache
;
1335 cache_cache
.nodelists
[numa_node_id()] = &initkmem_list3
[CACHE_CACHE
];
1337 cache_cache
.buffer_size
= ALIGN(cache_cache
.buffer_size
,
1340 for (order
= 0; order
< MAX_ORDER
; order
++) {
1341 cache_estimate(order
, cache_cache
.buffer_size
,
1342 cache_line_size(), 0, &left_over
, &cache_cache
.num
);
1343 if (cache_cache
.num
)
1346 BUG_ON(!cache_cache
.num
);
1347 cache_cache
.gfporder
= order
;
1348 cache_cache
.colour
= left_over
/ cache_cache
.colour_off
;
1349 cache_cache
.slab_size
= ALIGN(cache_cache
.num
* sizeof(kmem_bufctl_t
) +
1350 sizeof(struct slab
), cache_line_size());
1352 /* 2+3) create the kmalloc caches */
1353 sizes
= malloc_sizes
;
1354 names
= cache_names
;
1357 * Initialize the caches that provide memory for the array cache and the
1358 * kmem_list3 structures first. Without this, further allocations will
1362 sizes
[INDEX_AC
].cs_cachep
= kmem_cache_create(names
[INDEX_AC
].name
,
1363 sizes
[INDEX_AC
].cs_size
,
1364 ARCH_KMALLOC_MINALIGN
,
1365 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1368 if (INDEX_AC
!= INDEX_L3
) {
1369 sizes
[INDEX_L3
].cs_cachep
=
1370 kmem_cache_create(names
[INDEX_L3
].name
,
1371 sizes
[INDEX_L3
].cs_size
,
1372 ARCH_KMALLOC_MINALIGN
,
1373 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1377 while (sizes
->cs_size
!= ULONG_MAX
) {
1379 * For performance, all the general caches are L1 aligned.
1380 * This should be particularly beneficial on SMP boxes, as it
1381 * eliminates "false sharing".
1382 * Note for systems short on memory removing the alignment will
1383 * allow tighter packing of the smaller caches.
1385 if (!sizes
->cs_cachep
) {
1386 sizes
->cs_cachep
= kmem_cache_create(names
->name
,
1388 ARCH_KMALLOC_MINALIGN
,
1389 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1393 sizes
->cs_dmacachep
= kmem_cache_create(names
->name_dma
,
1395 ARCH_KMALLOC_MINALIGN
,
1396 ARCH_KMALLOC_FLAGS
|SLAB_CACHE_DMA
|
1402 /* 4) Replace the bootstrap head arrays */
1406 ptr
= kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1408 local_irq_disable();
1409 BUG_ON(cpu_cache_get(&cache_cache
) != &initarray_cache
.cache
);
1410 memcpy(ptr
, cpu_cache_get(&cache_cache
),
1411 sizeof(struct arraycache_init
));
1412 cache_cache
.array
[smp_processor_id()] = ptr
;
1415 ptr
= kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1417 local_irq_disable();
1418 BUG_ON(cpu_cache_get(malloc_sizes
[INDEX_AC
].cs_cachep
)
1419 != &initarray_generic
.cache
);
1420 memcpy(ptr
, cpu_cache_get(malloc_sizes
[INDEX_AC
].cs_cachep
),
1421 sizeof(struct arraycache_init
));
1422 malloc_sizes
[INDEX_AC
].cs_cachep
->array
[smp_processor_id()] =
1426 /* 5) Replace the bootstrap kmem_list3's */
1429 /* Replace the static kmem_list3 structures for the boot cpu */
1430 init_list(&cache_cache
, &initkmem_list3
[CACHE_CACHE
],
1433 for_each_online_node(node
) {
1434 init_list(malloc_sizes
[INDEX_AC
].cs_cachep
,
1435 &initkmem_list3
[SIZE_AC
+ node
], node
);
1437 if (INDEX_AC
!= INDEX_L3
) {
1438 init_list(malloc_sizes
[INDEX_L3
].cs_cachep
,
1439 &initkmem_list3
[SIZE_L3
+ node
],
1445 /* 6) resize the head arrays to their final sizes */
1447 struct kmem_cache
*cachep
;
1448 mutex_lock(&cache_chain_mutex
);
1449 list_for_each_entry(cachep
, &cache_chain
, next
)
1450 enable_cpucache(cachep
);
1451 mutex_unlock(&cache_chain_mutex
);
1455 g_cpucache_up
= FULL
;
1458 * Register a cpu startup notifier callback that initializes
1459 * cpu_cache_get for all new cpus
1461 register_cpu_notifier(&cpucache_notifier
);
1464 * The reap timers are started later, with a module init call: That part
1465 * of the kernel is not yet operational.
1469 static int __init
cpucache_init(void)
1474 * Register the timers that return unneeded pages to the page allocator
1476 for_each_online_cpu(cpu
)
1477 start_cpu_timer(cpu
);
1480 __initcall(cpucache_init
);
1483 * Interface to system's page allocator. No need to hold the cache-lock.
1485 * If we requested dmaable memory, we will get it. Even if we
1486 * did not request dmaable memory, we might get it, but that
1487 * would be relatively rare and ignorable.
1489 static void *kmem_getpages(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
1495 flags
|= cachep
->gfpflags
;
1497 /* nommu uses slab's for process anonymous memory allocations, so
1498 * requires __GFP_COMP to properly refcount higher order allocations"
1500 page
= alloc_pages_node(nodeid
, (flags
| __GFP_COMP
), cachep
->gfporder
);
1502 page
= alloc_pages_node(nodeid
, flags
, cachep
->gfporder
);
1506 addr
= page_address(page
);
1508 i
= (1 << cachep
->gfporder
);
1509 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1510 atomic_add(i
, &slab_reclaim_pages
);
1511 add_page_state(nr_slab
, i
);
1513 __SetPageSlab(page
);
1520 * Interface to system's page release.
1522 static void kmem_freepages(struct kmem_cache
*cachep
, void *addr
)
1524 unsigned long i
= (1 << cachep
->gfporder
);
1525 struct page
*page
= virt_to_page(addr
);
1526 const unsigned long nr_freed
= i
;
1529 BUG_ON(!PageSlab(page
));
1530 __ClearPageSlab(page
);
1533 sub_page_state(nr_slab
, nr_freed
);
1534 if (current
->reclaim_state
)
1535 current
->reclaim_state
->reclaimed_slab
+= nr_freed
;
1536 free_pages((unsigned long)addr
, cachep
->gfporder
);
1537 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1538 atomic_sub(1 << cachep
->gfporder
, &slab_reclaim_pages
);
1541 static void kmem_rcu_free(struct rcu_head
*head
)
1543 struct slab_rcu
*slab_rcu
= (struct slab_rcu
*)head
;
1544 struct kmem_cache
*cachep
= slab_rcu
->cachep
;
1546 kmem_freepages(cachep
, slab_rcu
->addr
);
1547 if (OFF_SLAB(cachep
))
1548 kmem_cache_free(cachep
->slabp_cache
, slab_rcu
);
1553 #ifdef CONFIG_DEBUG_PAGEALLOC
1554 static void store_stackinfo(struct kmem_cache
*cachep
, unsigned long *addr
,
1555 unsigned long caller
)
1557 int size
= obj_size(cachep
);
1559 addr
= (unsigned long *)&((char *)addr
)[obj_offset(cachep
)];
1561 if (size
< 5 * sizeof(unsigned long))
1564 *addr
++ = 0x12345678;
1566 *addr
++ = smp_processor_id();
1567 size
-= 3 * sizeof(unsigned long);
1569 unsigned long *sptr
= &caller
;
1570 unsigned long svalue
;
1572 while (!kstack_end(sptr
)) {
1574 if (kernel_text_address(svalue
)) {
1576 size
-= sizeof(unsigned long);
1577 if (size
<= sizeof(unsigned long))
1583 *addr
++ = 0x87654321;
1587 static void poison_obj(struct kmem_cache
*cachep
, void *addr
, unsigned char val
)
1589 int size
= obj_size(cachep
);
1590 addr
= &((char *)addr
)[obj_offset(cachep
)];
1592 memset(addr
, val
, size
);
1593 *(unsigned char *)(addr
+ size
- 1) = POISON_END
;
1596 static void dump_line(char *data
, int offset
, int limit
)
1599 printk(KERN_ERR
"%03x:", offset
);
1600 for (i
= 0; i
< limit
; i
++)
1601 printk(" %02x", (unsigned char)data
[offset
+ i
]);
1608 static void print_objinfo(struct kmem_cache
*cachep
, void *objp
, int lines
)
1613 if (cachep
->flags
& SLAB_RED_ZONE
) {
1614 printk(KERN_ERR
"Redzone: 0x%lx/0x%lx.\n",
1615 *dbg_redzone1(cachep
, objp
),
1616 *dbg_redzone2(cachep
, objp
));
1619 if (cachep
->flags
& SLAB_STORE_USER
) {
1620 printk(KERN_ERR
"Last user: [<%p>]",
1621 *dbg_userword(cachep
, objp
));
1622 print_symbol("(%s)",
1623 (unsigned long)*dbg_userword(cachep
, objp
));
1626 realobj
= (char *)objp
+ obj_offset(cachep
);
1627 size
= obj_size(cachep
);
1628 for (i
= 0; i
< size
&& lines
; i
+= 16, lines
--) {
1631 if (i
+ limit
> size
)
1633 dump_line(realobj
, i
, limit
);
1637 static void check_poison_obj(struct kmem_cache
*cachep
, void *objp
)
1643 realobj
= (char *)objp
+ obj_offset(cachep
);
1644 size
= obj_size(cachep
);
1646 for (i
= 0; i
< size
; i
++) {
1647 char exp
= POISON_FREE
;
1650 if (realobj
[i
] != exp
) {
1656 "Slab corruption: start=%p, len=%d\n",
1658 print_objinfo(cachep
, objp
, 0);
1660 /* Hexdump the affected line */
1663 if (i
+ limit
> size
)
1665 dump_line(realobj
, i
, limit
);
1668 /* Limit to 5 lines */
1674 /* Print some data about the neighboring objects, if they
1677 struct slab
*slabp
= virt_to_slab(objp
);
1680 objnr
= obj_to_index(cachep
, slabp
, objp
);
1682 objp
= index_to_obj(cachep
, slabp
, objnr
- 1);
1683 realobj
= (char *)objp
+ obj_offset(cachep
);
1684 printk(KERN_ERR
"Prev obj: start=%p, len=%d\n",
1686 print_objinfo(cachep
, objp
, 2);
1688 if (objnr
+ 1 < cachep
->num
) {
1689 objp
= index_to_obj(cachep
, slabp
, objnr
+ 1);
1690 realobj
= (char *)objp
+ obj_offset(cachep
);
1691 printk(KERN_ERR
"Next obj: start=%p, len=%d\n",
1693 print_objinfo(cachep
, objp
, 2);
1701 * slab_destroy_objs - destroy a slab and its objects
1702 * @cachep: cache pointer being destroyed
1703 * @slabp: slab pointer being destroyed
1705 * Call the registered destructor for each object in a slab that is being
1708 static void slab_destroy_objs(struct kmem_cache
*cachep
, struct slab
*slabp
)
1711 for (i
= 0; i
< cachep
->num
; i
++) {
1712 void *objp
= index_to_obj(cachep
, slabp
, i
);
1714 if (cachep
->flags
& SLAB_POISON
) {
1715 #ifdef CONFIG_DEBUG_PAGEALLOC
1716 if (cachep
->buffer_size
% PAGE_SIZE
== 0 &&
1718 kernel_map_pages(virt_to_page(objp
),
1719 cachep
->buffer_size
/ PAGE_SIZE
, 1);
1721 check_poison_obj(cachep
, objp
);
1723 check_poison_obj(cachep
, objp
);
1726 if (cachep
->flags
& SLAB_RED_ZONE
) {
1727 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
1728 slab_error(cachep
, "start of a freed object "
1730 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
1731 slab_error(cachep
, "end of a freed object "
1734 if (cachep
->dtor
&& !(cachep
->flags
& SLAB_POISON
))
1735 (cachep
->dtor
) (objp
+ obj_offset(cachep
), cachep
, 0);
1739 static void slab_destroy_objs(struct kmem_cache
*cachep
, struct slab
*slabp
)
1743 for (i
= 0; i
< cachep
->num
; i
++) {
1744 void *objp
= index_to_obj(cachep
, slabp
, i
);
1745 (cachep
->dtor
) (objp
, cachep
, 0);
1752 * slab_destroy - destroy and release all objects in a slab
1753 * @cachep: cache pointer being destroyed
1754 * @slabp: slab pointer being destroyed
1756 * Destroy all the objs in a slab, and release the mem back to the system.
1757 * Before calling the slab must have been unlinked from the cache. The
1758 * cache-lock is not held/needed.
1760 static void slab_destroy(struct kmem_cache
*cachep
, struct slab
*slabp
)
1762 void *addr
= slabp
->s_mem
- slabp
->colouroff
;
1764 slab_destroy_objs(cachep
, slabp
);
1765 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
)) {
1766 struct slab_rcu
*slab_rcu
;
1768 slab_rcu
= (struct slab_rcu
*)slabp
;
1769 slab_rcu
->cachep
= cachep
;
1770 slab_rcu
->addr
= addr
;
1771 call_rcu(&slab_rcu
->head
, kmem_rcu_free
);
1773 kmem_freepages(cachep
, addr
);
1774 if (OFF_SLAB(cachep
))
1775 kmem_cache_free(cachep
->slabp_cache
, slabp
);
1780 * For setting up all the kmem_list3s for cache whose buffer_size is same as
1781 * size of kmem_list3.
1783 static void set_up_list3s(struct kmem_cache
*cachep
, int index
)
1787 for_each_online_node(node
) {
1788 cachep
->nodelists
[node
] = &initkmem_list3
[index
+ node
];
1789 cachep
->nodelists
[node
]->next_reap
= jiffies
+
1791 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1796 * calculate_slab_order - calculate size (page order) of slabs
1797 * @cachep: pointer to the cache that is being created
1798 * @size: size of objects to be created in this cache.
1799 * @align: required alignment for the objects.
1800 * @flags: slab allocation flags
1802 * Also calculates the number of objects per slab.
1804 * This could be made much more intelligent. For now, try to avoid using
1805 * high order pages for slabs. When the gfp() functions are more friendly
1806 * towards high-order requests, this should be changed.
1808 static size_t calculate_slab_order(struct kmem_cache
*cachep
,
1809 size_t size
, size_t align
, unsigned long flags
)
1811 unsigned long offslab_limit
;
1812 size_t left_over
= 0;
1815 for (gfporder
= 0; gfporder
<= MAX_GFP_ORDER
; gfporder
++) {
1819 cache_estimate(gfporder
, size
, align
, flags
, &remainder
, &num
);
1823 if (flags
& CFLGS_OFF_SLAB
) {
1825 * Max number of objs-per-slab for caches which
1826 * use off-slab slabs. Needed to avoid a possible
1827 * looping condition in cache_grow().
1829 offslab_limit
= size
- sizeof(struct slab
);
1830 offslab_limit
/= sizeof(kmem_bufctl_t
);
1832 if (num
> offslab_limit
)
1836 /* Found something acceptable - save it away */
1838 cachep
->gfporder
= gfporder
;
1839 left_over
= remainder
;
1842 * A VFS-reclaimable slab tends to have most allocations
1843 * as GFP_NOFS and we really don't want to have to be allocating
1844 * higher-order pages when we are unable to shrink dcache.
1846 if (flags
& SLAB_RECLAIM_ACCOUNT
)
1850 * Large number of objects is good, but very large slabs are
1851 * currently bad for the gfp()s.
1853 if (gfporder
>= slab_break_gfp_order
)
1857 * Acceptable internal fragmentation?
1859 if (left_over
* 8 <= (PAGE_SIZE
<< gfporder
))
1865 static void setup_cpu_cache(struct kmem_cache
*cachep
)
1867 if (g_cpucache_up
== FULL
) {
1868 enable_cpucache(cachep
);
1871 if (g_cpucache_up
== NONE
) {
1873 * Note: the first kmem_cache_create must create the cache
1874 * that's used by kmalloc(24), otherwise the creation of
1875 * further caches will BUG().
1877 cachep
->array
[smp_processor_id()] = &initarray_generic
.cache
;
1880 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
1881 * the first cache, then we need to set up all its list3s,
1882 * otherwise the creation of further caches will BUG().
1884 set_up_list3s(cachep
, SIZE_AC
);
1885 if (INDEX_AC
== INDEX_L3
)
1886 g_cpucache_up
= PARTIAL_L3
;
1888 g_cpucache_up
= PARTIAL_AC
;
1890 cachep
->array
[smp_processor_id()] =
1891 kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1893 if (g_cpucache_up
== PARTIAL_AC
) {
1894 set_up_list3s(cachep
, SIZE_L3
);
1895 g_cpucache_up
= PARTIAL_L3
;
1898 for_each_online_node(node
) {
1899 cachep
->nodelists
[node
] =
1900 kmalloc_node(sizeof(struct kmem_list3
),
1902 BUG_ON(!cachep
->nodelists
[node
]);
1903 kmem_list3_init(cachep
->nodelists
[node
]);
1907 cachep
->nodelists
[numa_node_id()]->next_reap
=
1908 jiffies
+ REAPTIMEOUT_LIST3
+
1909 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1911 cpu_cache_get(cachep
)->avail
= 0;
1912 cpu_cache_get(cachep
)->limit
= BOOT_CPUCACHE_ENTRIES
;
1913 cpu_cache_get(cachep
)->batchcount
= 1;
1914 cpu_cache_get(cachep
)->touched
= 0;
1915 cachep
->batchcount
= 1;
1916 cachep
->limit
= BOOT_CPUCACHE_ENTRIES
;
1920 * kmem_cache_create - Create a cache.
1921 * @name: A string which is used in /proc/slabinfo to identify this cache.
1922 * @size: The size of objects to be created in this cache.
1923 * @align: The required alignment for the objects.
1924 * @flags: SLAB flags
1925 * @ctor: A constructor for the objects.
1926 * @dtor: A destructor for the objects.
1928 * Returns a ptr to the cache on success, NULL on failure.
1929 * Cannot be called within a int, but can be interrupted.
1930 * The @ctor is run when new pages are allocated by the cache
1931 * and the @dtor is run before the pages are handed back.
1933 * @name must be valid until the cache is destroyed. This implies that
1934 * the module calling this has to destroy the cache before getting unloaded.
1938 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
1939 * to catch references to uninitialised memory.
1941 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
1942 * for buffer overruns.
1944 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
1945 * cacheline. This can be beneficial if you're counting cycles as closely
1949 kmem_cache_create (const char *name
, size_t size
, size_t align
,
1950 unsigned long flags
,
1951 void (*ctor
)(void*, struct kmem_cache
*, unsigned long),
1952 void (*dtor
)(void*, struct kmem_cache
*, unsigned long))
1954 size_t left_over
, slab_size
, ralign
;
1955 struct kmem_cache
*cachep
= NULL
;
1956 struct list_head
*p
;
1959 * Sanity checks... these are all serious usage bugs.
1961 if (!name
|| in_interrupt() || (size
< BYTES_PER_WORD
) ||
1962 (size
> (1 << MAX_OBJ_ORDER
) * PAGE_SIZE
) || (dtor
&& !ctor
)) {
1963 printk(KERN_ERR
"%s: Early error in slab %s\n", __FUNCTION__
,
1969 * Prevent CPUs from coming and going.
1970 * lock_cpu_hotplug() nests outside cache_chain_mutex
1974 mutex_lock(&cache_chain_mutex
);
1976 list_for_each(p
, &cache_chain
) {
1977 struct kmem_cache
*pc
= list_entry(p
, struct kmem_cache
, next
);
1978 mm_segment_t old_fs
= get_fs();
1983 * This happens when the module gets unloaded and doesn't
1984 * destroy its slab cache and no-one else reuses the vmalloc
1985 * area of the module. Print a warning.
1988 res
= __get_user(tmp
, pc
->name
);
1991 printk("SLAB: cache with size %d has lost its name\n",
1996 if (!strcmp(pc
->name
, name
)) {
1997 printk("kmem_cache_create: duplicate cache %s\n", name
);
2004 WARN_ON(strchr(name
, ' ')); /* It confuses parsers */
2005 if ((flags
& SLAB_DEBUG_INITIAL
) && !ctor
) {
2006 /* No constructor, but inital state check requested */
2007 printk(KERN_ERR
"%s: No con, but init state check "
2008 "requested - %s\n", __FUNCTION__
, name
);
2009 flags
&= ~SLAB_DEBUG_INITIAL
;
2013 * Enable redzoning and last user accounting, except for caches with
2014 * large objects, if the increased size would increase the object size
2015 * above the next power of two: caches with object sizes just above a
2016 * power of two have a significant amount of internal fragmentation.
2018 if (size
< 4096 || fls(size
- 1) == fls(size
-1 + 3 * BYTES_PER_WORD
))
2019 flags
|= SLAB_RED_ZONE
| SLAB_STORE_USER
;
2020 if (!(flags
& SLAB_DESTROY_BY_RCU
))
2021 flags
|= SLAB_POISON
;
2023 if (flags
& SLAB_DESTROY_BY_RCU
)
2024 BUG_ON(flags
& SLAB_POISON
);
2026 if (flags
& SLAB_DESTROY_BY_RCU
)
2030 * Always checks flags, a caller might be expecting debug support which
2033 BUG_ON(flags
& ~CREATE_MASK
);
2036 * Check that size is in terms of words. This is needed to avoid
2037 * unaligned accesses for some archs when redzoning is used, and makes
2038 * sure any on-slab bufctl's are also correctly aligned.
2040 if (size
& (BYTES_PER_WORD
- 1)) {
2041 size
+= (BYTES_PER_WORD
- 1);
2042 size
&= ~(BYTES_PER_WORD
- 1);
2045 /* calculate the final buffer alignment: */
2047 /* 1) arch recommendation: can be overridden for debug */
2048 if (flags
& SLAB_HWCACHE_ALIGN
) {
2050 * Default alignment: as specified by the arch code. Except if
2051 * an object is really small, then squeeze multiple objects into
2054 ralign
= cache_line_size();
2055 while (size
<= ralign
/ 2)
2058 ralign
= BYTES_PER_WORD
;
2060 /* 2) arch mandated alignment: disables debug if necessary */
2061 if (ralign
< ARCH_SLAB_MINALIGN
) {
2062 ralign
= ARCH_SLAB_MINALIGN
;
2063 if (ralign
> BYTES_PER_WORD
)
2064 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2066 /* 3) caller mandated alignment: disables debug if necessary */
2067 if (ralign
< align
) {
2069 if (ralign
> BYTES_PER_WORD
)
2070 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2073 * 4) Store it. Note that the debug code below can reduce
2074 * the alignment to BYTES_PER_WORD.
2078 /* Get cache's description obj. */
2079 cachep
= kmem_cache_zalloc(&cache_cache
, SLAB_KERNEL
);
2084 cachep
->obj_size
= size
;
2086 if (flags
& SLAB_RED_ZONE
) {
2087 /* redzoning only works with word aligned caches */
2088 align
= BYTES_PER_WORD
;
2090 /* add space for red zone words */
2091 cachep
->obj_offset
+= BYTES_PER_WORD
;
2092 size
+= 2 * BYTES_PER_WORD
;
2094 if (flags
& SLAB_STORE_USER
) {
2095 /* user store requires word alignment and
2096 * one word storage behind the end of the real
2099 align
= BYTES_PER_WORD
;
2100 size
+= BYTES_PER_WORD
;
2102 #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
2103 if (size
>= malloc_sizes
[INDEX_L3
+ 1].cs_size
2104 && cachep
->obj_size
> cache_line_size() && size
< PAGE_SIZE
) {
2105 cachep
->obj_offset
+= PAGE_SIZE
- size
;
2111 /* Determine if the slab management is 'on' or 'off' slab. */
2112 if (size
>= (PAGE_SIZE
>> 3))
2114 * Size is large, assume best to place the slab management obj
2115 * off-slab (should allow better packing of objs).
2117 flags
|= CFLGS_OFF_SLAB
;
2119 size
= ALIGN(size
, align
);
2121 left_over
= calculate_slab_order(cachep
, size
, align
, flags
);
2124 printk("kmem_cache_create: couldn't create cache %s.\n", name
);
2125 kmem_cache_free(&cache_cache
, cachep
);
2129 slab_size
= ALIGN(cachep
->num
* sizeof(kmem_bufctl_t
)
2130 + sizeof(struct slab
), align
);
2133 * If the slab has been placed off-slab, and we have enough space then
2134 * move it on-slab. This is at the expense of any extra colouring.
2136 if (flags
& CFLGS_OFF_SLAB
&& left_over
>= slab_size
) {
2137 flags
&= ~CFLGS_OFF_SLAB
;
2138 left_over
-= slab_size
;
2141 if (flags
& CFLGS_OFF_SLAB
) {
2142 /* really off slab. No need for manual alignment */
2144 cachep
->num
* sizeof(kmem_bufctl_t
) + sizeof(struct slab
);
2147 cachep
->colour_off
= cache_line_size();
2148 /* Offset must be a multiple of the alignment. */
2149 if (cachep
->colour_off
< align
)
2150 cachep
->colour_off
= align
;
2151 cachep
->colour
= left_over
/ cachep
->colour_off
;
2152 cachep
->slab_size
= slab_size
;
2153 cachep
->flags
= flags
;
2154 cachep
->gfpflags
= 0;
2155 if (flags
& SLAB_CACHE_DMA
)
2156 cachep
->gfpflags
|= GFP_DMA
;
2157 cachep
->buffer_size
= size
;
2159 if (flags
& CFLGS_OFF_SLAB
)
2160 cachep
->slabp_cache
= kmem_find_general_cachep(slab_size
, 0u);
2161 cachep
->ctor
= ctor
;
2162 cachep
->dtor
= dtor
;
2163 cachep
->name
= name
;
2166 setup_cpu_cache(cachep
);
2168 /* cache setup completed, link it into the list */
2169 list_add(&cachep
->next
, &cache_chain
);
2171 if (!cachep
&& (flags
& SLAB_PANIC
))
2172 panic("kmem_cache_create(): failed to create slab `%s'\n",
2174 mutex_unlock(&cache_chain_mutex
);
2175 unlock_cpu_hotplug();
2178 EXPORT_SYMBOL(kmem_cache_create
);
2181 static void check_irq_off(void)
2183 BUG_ON(!irqs_disabled());
2186 static void check_irq_on(void)
2188 BUG_ON(irqs_disabled());
2191 static void check_spinlock_acquired(struct kmem_cache
*cachep
)
2195 assert_spin_locked(&cachep
->nodelists
[numa_node_id()]->list_lock
);
2199 static void check_spinlock_acquired_node(struct kmem_cache
*cachep
, int node
)
2203 assert_spin_locked(&cachep
->nodelists
[node
]->list_lock
);
2208 #define check_irq_off() do { } while(0)
2209 #define check_irq_on() do { } while(0)
2210 #define check_spinlock_acquired(x) do { } while(0)
2211 #define check_spinlock_acquired_node(x, y) do { } while(0)
2214 static void drain_array(struct kmem_cache
*cachep
, struct kmem_list3
*l3
,
2215 struct array_cache
*ac
,
2216 int force
, int node
);
2218 static void do_drain(void *arg
)
2220 struct kmem_cache
*cachep
= arg
;
2221 struct array_cache
*ac
;
2222 int node
= numa_node_id();
2225 ac
= cpu_cache_get(cachep
);
2226 spin_lock(&cachep
->nodelists
[node
]->list_lock
);
2227 free_block(cachep
, ac
->entry
, ac
->avail
, node
);
2228 spin_unlock(&cachep
->nodelists
[node
]->list_lock
);
2232 static void drain_cpu_caches(struct kmem_cache
*cachep
)
2234 struct kmem_list3
*l3
;
2237 on_each_cpu(do_drain
, cachep
, 1, 1);
2239 for_each_online_node(node
) {
2240 l3
= cachep
->nodelists
[node
];
2241 if (l3
&& l3
->alien
)
2242 drain_alien_cache(cachep
, l3
->alien
);
2245 for_each_online_node(node
) {
2246 l3
= cachep
->nodelists
[node
];
2248 drain_array(cachep
, l3
, l3
->shared
, 1, node
);
2252 static int __node_shrink(struct kmem_cache
*cachep
, int node
)
2255 struct kmem_list3
*l3
= cachep
->nodelists
[node
];
2259 struct list_head
*p
;
2261 p
= l3
->slabs_free
.prev
;
2262 if (p
== &l3
->slabs_free
)
2265 slabp
= list_entry(l3
->slabs_free
.prev
, struct slab
, list
);
2267 BUG_ON(slabp
->inuse
);
2269 list_del(&slabp
->list
);
2271 l3
->free_objects
-= cachep
->num
;
2272 spin_unlock_irq(&l3
->list_lock
);
2273 slab_destroy(cachep
, slabp
);
2274 spin_lock_irq(&l3
->list_lock
);
2276 ret
= !list_empty(&l3
->slabs_full
) || !list_empty(&l3
->slabs_partial
);
2280 static int __cache_shrink(struct kmem_cache
*cachep
)
2283 struct kmem_list3
*l3
;
2285 drain_cpu_caches(cachep
);
2288 for_each_online_node(i
) {
2289 l3
= cachep
->nodelists
[i
];
2291 spin_lock_irq(&l3
->list_lock
);
2292 ret
+= __node_shrink(cachep
, i
);
2293 spin_unlock_irq(&l3
->list_lock
);
2296 return (ret
? 1 : 0);
2300 * kmem_cache_shrink - Shrink a cache.
2301 * @cachep: The cache to shrink.
2303 * Releases as many slabs as possible for a cache.
2304 * To help debugging, a zero exit status indicates all slabs were released.
2306 int kmem_cache_shrink(struct kmem_cache
*cachep
)
2308 BUG_ON(!cachep
|| in_interrupt());
2310 return __cache_shrink(cachep
);
2312 EXPORT_SYMBOL(kmem_cache_shrink
);
2315 * kmem_cache_destroy - delete a cache
2316 * @cachep: the cache to destroy
2318 * Remove a struct kmem_cache object from the slab cache.
2319 * Returns 0 on success.
2321 * It is expected this function will be called by a module when it is
2322 * unloaded. This will remove the cache completely, and avoid a duplicate
2323 * cache being allocated each time a module is loaded and unloaded, if the
2324 * module doesn't have persistent in-kernel storage across loads and unloads.
2326 * The cache must be empty before calling this function.
2328 * The caller must guarantee that noone will allocate memory from the cache
2329 * during the kmem_cache_destroy().
2331 int kmem_cache_destroy(struct kmem_cache
*cachep
)
2334 struct kmem_list3
*l3
;
2336 BUG_ON(!cachep
|| in_interrupt());
2338 /* Don't let CPUs to come and go */
2341 /* Find the cache in the chain of caches. */
2342 mutex_lock(&cache_chain_mutex
);
2344 * the chain is never empty, cache_cache is never destroyed
2346 list_del(&cachep
->next
);
2347 mutex_unlock(&cache_chain_mutex
);
2349 if (__cache_shrink(cachep
)) {
2350 slab_error(cachep
, "Can't free all objects");
2351 mutex_lock(&cache_chain_mutex
);
2352 list_add(&cachep
->next
, &cache_chain
);
2353 mutex_unlock(&cache_chain_mutex
);
2354 unlock_cpu_hotplug();
2358 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
))
2361 for_each_online_cpu(i
)
2362 kfree(cachep
->array
[i
]);
2364 /* NUMA: free the list3 structures */
2365 for_each_online_node(i
) {
2366 l3
= cachep
->nodelists
[i
];
2369 free_alien_cache(l3
->alien
);
2373 kmem_cache_free(&cache_cache
, cachep
);
2374 unlock_cpu_hotplug();
2377 EXPORT_SYMBOL(kmem_cache_destroy
);
2379 /* Get the memory for a slab management obj. */
2380 static struct slab
*alloc_slabmgmt(struct kmem_cache
*cachep
, void *objp
,
2381 int colour_off
, gfp_t local_flags
,
2386 if (OFF_SLAB(cachep
)) {
2387 /* Slab management obj is off-slab. */
2388 slabp
= kmem_cache_alloc_node(cachep
->slabp_cache
,
2389 local_flags
, nodeid
);
2393 slabp
= objp
+ colour_off
;
2394 colour_off
+= cachep
->slab_size
;
2397 slabp
->colouroff
= colour_off
;
2398 slabp
->s_mem
= objp
+ colour_off
;
2399 slabp
->nodeid
= nodeid
;
2403 static inline kmem_bufctl_t
*slab_bufctl(struct slab
*slabp
)
2405 return (kmem_bufctl_t
*) (slabp
+ 1);
2408 static void cache_init_objs(struct kmem_cache
*cachep
,
2409 struct slab
*slabp
, unsigned long ctor_flags
)
2413 for (i
= 0; i
< cachep
->num
; i
++) {
2414 void *objp
= index_to_obj(cachep
, slabp
, i
);
2416 /* need to poison the objs? */
2417 if (cachep
->flags
& SLAB_POISON
)
2418 poison_obj(cachep
, objp
, POISON_FREE
);
2419 if (cachep
->flags
& SLAB_STORE_USER
)
2420 *dbg_userword(cachep
, objp
) = NULL
;
2422 if (cachep
->flags
& SLAB_RED_ZONE
) {
2423 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2424 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2427 * Constructors are not allowed to allocate memory from the same
2428 * cache which they are a constructor for. Otherwise, deadlock.
2429 * They must also be threaded.
2431 if (cachep
->ctor
&& !(cachep
->flags
& SLAB_POISON
))
2432 cachep
->ctor(objp
+ obj_offset(cachep
), cachep
,
2435 if (cachep
->flags
& SLAB_RED_ZONE
) {
2436 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
2437 slab_error(cachep
, "constructor overwrote the"
2438 " end of an object");
2439 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
2440 slab_error(cachep
, "constructor overwrote the"
2441 " start of an object");
2443 if ((cachep
->buffer_size
% PAGE_SIZE
) == 0 &&
2444 OFF_SLAB(cachep
) && cachep
->flags
& SLAB_POISON
)
2445 kernel_map_pages(virt_to_page(objp
),
2446 cachep
->buffer_size
/ PAGE_SIZE
, 0);
2449 cachep
->ctor(objp
, cachep
, ctor_flags
);
2451 slab_bufctl(slabp
)[i
] = i
+ 1;
2453 slab_bufctl(slabp
)[i
- 1] = BUFCTL_END
;
2457 static void kmem_flagcheck(struct kmem_cache
*cachep
, gfp_t flags
)
2459 if (flags
& SLAB_DMA
)
2460 BUG_ON(!(cachep
->gfpflags
& GFP_DMA
));
2462 BUG_ON(cachep
->gfpflags
& GFP_DMA
);
2465 static void *slab_get_obj(struct kmem_cache
*cachep
, struct slab
*slabp
,
2468 void *objp
= index_to_obj(cachep
, slabp
, slabp
->free
);
2472 next
= slab_bufctl(slabp
)[slabp
->free
];
2474 slab_bufctl(slabp
)[slabp
->free
] = BUFCTL_FREE
;
2475 WARN_ON(slabp
->nodeid
!= nodeid
);
2482 static void slab_put_obj(struct kmem_cache
*cachep
, struct slab
*slabp
,
2483 void *objp
, int nodeid
)
2485 unsigned int objnr
= obj_to_index(cachep
, slabp
, objp
);
2488 /* Verify that the slab belongs to the intended node */
2489 WARN_ON(slabp
->nodeid
!= nodeid
);
2491 if (slab_bufctl(slabp
)[objnr
] + 1 <= SLAB_LIMIT
+ 1) {
2492 printk(KERN_ERR
"slab: double free detected in cache "
2493 "'%s', objp %p\n", cachep
->name
, objp
);
2497 slab_bufctl(slabp
)[objnr
] = slabp
->free
;
2498 slabp
->free
= objnr
;
2503 * Map pages beginning at addr to the given cache and slab. This is required
2504 * for the slab allocator to be able to lookup the cache and slab of a
2505 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
2507 static void slab_map_pages(struct kmem_cache
*cache
, struct slab
*slab
,
2513 page
= virt_to_page(addr
);
2516 if (likely(!PageCompound(page
)))
2517 nr_pages
<<= cache
->gfporder
;
2520 page_set_cache(page
, cache
);
2521 page_set_slab(page
, slab
);
2523 } while (--nr_pages
);
2527 * Grow (by 1) the number of slabs within a cache. This is called by
2528 * kmem_cache_alloc() when there are no active objs left in a cache.
2530 static int cache_grow(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
2536 unsigned long ctor_flags
;
2537 struct kmem_list3
*l3
;
2540 * Be lazy and only check for valid flags here, keeping it out of the
2541 * critical path in kmem_cache_alloc().
2543 BUG_ON(flags
& ~(SLAB_DMA
| SLAB_LEVEL_MASK
| SLAB_NO_GROW
));
2544 if (flags
& SLAB_NO_GROW
)
2547 ctor_flags
= SLAB_CTOR_CONSTRUCTOR
;
2548 local_flags
= (flags
& SLAB_LEVEL_MASK
);
2549 if (!(local_flags
& __GFP_WAIT
))
2551 * Not allowed to sleep. Need to tell a constructor about
2552 * this - it might need to know...
2554 ctor_flags
|= SLAB_CTOR_ATOMIC
;
2556 /* Take the l3 list lock to change the colour_next on this node */
2558 l3
= cachep
->nodelists
[nodeid
];
2559 spin_lock(&l3
->list_lock
);
2561 /* Get colour for the slab, and cal the next value. */
2562 offset
= l3
->colour_next
;
2564 if (l3
->colour_next
>= cachep
->colour
)
2565 l3
->colour_next
= 0;
2566 spin_unlock(&l3
->list_lock
);
2568 offset
*= cachep
->colour_off
;
2570 if (local_flags
& __GFP_WAIT
)
2574 * The test for missing atomic flag is performed here, rather than
2575 * the more obvious place, simply to reduce the critical path length
2576 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2577 * will eventually be caught here (where it matters).
2579 kmem_flagcheck(cachep
, flags
);
2582 * Get mem for the objs. Attempt to allocate a physical page from
2585 objp
= kmem_getpages(cachep
, flags
, nodeid
);
2589 /* Get slab management. */
2590 slabp
= alloc_slabmgmt(cachep
, objp
, offset
, local_flags
, nodeid
);
2594 slabp
->nodeid
= nodeid
;
2595 slab_map_pages(cachep
, slabp
, objp
);
2597 cache_init_objs(cachep
, slabp
, ctor_flags
);
2599 if (local_flags
& __GFP_WAIT
)
2600 local_irq_disable();
2602 spin_lock(&l3
->list_lock
);
2604 /* Make slab active. */
2605 list_add_tail(&slabp
->list
, &(l3
->slabs_free
));
2606 STATS_INC_GROWN(cachep
);
2607 l3
->free_objects
+= cachep
->num
;
2608 spin_unlock(&l3
->list_lock
);
2611 kmem_freepages(cachep
, objp
);
2613 if (local_flags
& __GFP_WAIT
)
2614 local_irq_disable();
2621 * Perform extra freeing checks:
2622 * - detect bad pointers.
2623 * - POISON/RED_ZONE checking
2624 * - destructor calls, for caches with POISON+dtor
2626 static void kfree_debugcheck(const void *objp
)
2630 if (!virt_addr_valid(objp
)) {
2631 printk(KERN_ERR
"kfree_debugcheck: out of range ptr %lxh.\n",
2632 (unsigned long)objp
);
2635 page
= virt_to_page(objp
);
2636 if (!PageSlab(page
)) {
2637 printk(KERN_ERR
"kfree_debugcheck: bad ptr %lxh.\n",
2638 (unsigned long)objp
);
2643 static void *cache_free_debugcheck(struct kmem_cache
*cachep
, void *objp
,
2650 objp
-= obj_offset(cachep
);
2651 kfree_debugcheck(objp
);
2652 page
= virt_to_page(objp
);
2654 if (page_get_cache(page
) != cachep
) {
2655 printk(KERN_ERR
"mismatch in kmem_cache_free: expected "
2656 "cache %p, got %p\n",
2657 page_get_cache(page
), cachep
);
2658 printk(KERN_ERR
"%p is %s.\n", cachep
, cachep
->name
);
2659 printk(KERN_ERR
"%p is %s.\n", page_get_cache(page
),
2660 page_get_cache(page
)->name
);
2663 slabp
= page_get_slab(page
);
2665 if (cachep
->flags
& SLAB_RED_ZONE
) {
2666 if (*dbg_redzone1(cachep
, objp
) != RED_ACTIVE
||
2667 *dbg_redzone2(cachep
, objp
) != RED_ACTIVE
) {
2668 slab_error(cachep
, "double free, or memory outside"
2669 " object was overwritten");
2670 printk(KERN_ERR
"%p: redzone 1:0x%lx, "
2671 "redzone 2:0x%lx.\n",
2672 objp
, *dbg_redzone1(cachep
, objp
),
2673 *dbg_redzone2(cachep
, objp
));
2675 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2676 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2678 if (cachep
->flags
& SLAB_STORE_USER
)
2679 *dbg_userword(cachep
, objp
) = caller
;
2681 objnr
= obj_to_index(cachep
, slabp
, objp
);
2683 BUG_ON(objnr
>= cachep
->num
);
2684 BUG_ON(objp
!= index_to_obj(cachep
, slabp
, objnr
));
2686 if (cachep
->flags
& SLAB_DEBUG_INITIAL
) {
2688 * Need to call the slab's constructor so the caller can
2689 * perform a verify of its state (debugging). Called without
2690 * the cache-lock held.
2692 cachep
->ctor(objp
+ obj_offset(cachep
),
2693 cachep
, SLAB_CTOR_CONSTRUCTOR
| SLAB_CTOR_VERIFY
);
2695 if (cachep
->flags
& SLAB_POISON
&& cachep
->dtor
) {
2696 /* we want to cache poison the object,
2697 * call the destruction callback
2699 cachep
->dtor(objp
+ obj_offset(cachep
), cachep
, 0);
2701 #ifdef CONFIG_DEBUG_SLAB_LEAK
2702 slab_bufctl(slabp
)[objnr
] = BUFCTL_FREE
;
2704 if (cachep
->flags
& SLAB_POISON
) {
2705 #ifdef CONFIG_DEBUG_PAGEALLOC
2706 if ((cachep
->buffer_size
% PAGE_SIZE
)==0 && OFF_SLAB(cachep
)) {
2707 store_stackinfo(cachep
, objp
, (unsigned long)caller
);
2708 kernel_map_pages(virt_to_page(objp
),
2709 cachep
->buffer_size
/ PAGE_SIZE
, 0);
2711 poison_obj(cachep
, objp
, POISON_FREE
);
2714 poison_obj(cachep
, objp
, POISON_FREE
);
2720 static void check_slabp(struct kmem_cache
*cachep
, struct slab
*slabp
)
2725 /* Check slab's freelist to see if this obj is there. */
2726 for (i
= slabp
->free
; i
!= BUFCTL_END
; i
= slab_bufctl(slabp
)[i
]) {
2728 if (entries
> cachep
->num
|| i
>= cachep
->num
)
2731 if (entries
!= cachep
->num
- slabp
->inuse
) {
2733 printk(KERN_ERR
"slab: Internal list corruption detected in "
2734 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2735 cachep
->name
, cachep
->num
, slabp
, slabp
->inuse
);
2737 i
< sizeof(*slabp
) + cachep
->num
* sizeof(kmem_bufctl_t
);
2740 printk("\n%03x:", i
);
2741 printk(" %02x", ((unsigned char *)slabp
)[i
]);
2748 #define kfree_debugcheck(x) do { } while(0)
2749 #define cache_free_debugcheck(x,objp,z) (objp)
2750 #define check_slabp(x,y) do { } while(0)
2753 static void *cache_alloc_refill(struct kmem_cache
*cachep
, gfp_t flags
)
2756 struct kmem_list3
*l3
;
2757 struct array_cache
*ac
;
2760 ac
= cpu_cache_get(cachep
);
2762 batchcount
= ac
->batchcount
;
2763 if (!ac
->touched
&& batchcount
> BATCHREFILL_LIMIT
) {
2765 * If there was little recent activity on this cache, then
2766 * perform only a partial refill. Otherwise we could generate
2769 batchcount
= BATCHREFILL_LIMIT
;
2771 l3
= cachep
->nodelists
[numa_node_id()];
2773 BUG_ON(ac
->avail
> 0 || !l3
);
2774 spin_lock(&l3
->list_lock
);
2776 /* See if we can refill from the shared array */
2777 if (l3
->shared
&& transfer_objects(ac
, l3
->shared
, batchcount
))
2780 while (batchcount
> 0) {
2781 struct list_head
*entry
;
2783 /* Get slab alloc is to come from. */
2784 entry
= l3
->slabs_partial
.next
;
2785 if (entry
== &l3
->slabs_partial
) {
2786 l3
->free_touched
= 1;
2787 entry
= l3
->slabs_free
.next
;
2788 if (entry
== &l3
->slabs_free
)
2792 slabp
= list_entry(entry
, struct slab
, list
);
2793 check_slabp(cachep
, slabp
);
2794 check_spinlock_acquired(cachep
);
2795 while (slabp
->inuse
< cachep
->num
&& batchcount
--) {
2796 STATS_INC_ALLOCED(cachep
);
2797 STATS_INC_ACTIVE(cachep
);
2798 STATS_SET_HIGH(cachep
);
2800 ac
->entry
[ac
->avail
++] = slab_get_obj(cachep
, slabp
,
2803 check_slabp(cachep
, slabp
);
2805 /* move slabp to correct slabp list: */
2806 list_del(&slabp
->list
);
2807 if (slabp
->free
== BUFCTL_END
)
2808 list_add(&slabp
->list
, &l3
->slabs_full
);
2810 list_add(&slabp
->list
, &l3
->slabs_partial
);
2814 l3
->free_objects
-= ac
->avail
;
2816 spin_unlock(&l3
->list_lock
);
2818 if (unlikely(!ac
->avail
)) {
2820 x
= cache_grow(cachep
, flags
, numa_node_id());
2822 /* cache_grow can reenable interrupts, then ac could change. */
2823 ac
= cpu_cache_get(cachep
);
2824 if (!x
&& ac
->avail
== 0) /* no objects in sight? abort */
2827 if (!ac
->avail
) /* objects refilled by interrupt? */
2831 return ac
->entry
[--ac
->avail
];
2834 static inline void cache_alloc_debugcheck_before(struct kmem_cache
*cachep
,
2837 might_sleep_if(flags
& __GFP_WAIT
);
2839 kmem_flagcheck(cachep
, flags
);
2844 static void *cache_alloc_debugcheck_after(struct kmem_cache
*cachep
,
2845 gfp_t flags
, void *objp
, void *caller
)
2849 if (cachep
->flags
& SLAB_POISON
) {
2850 #ifdef CONFIG_DEBUG_PAGEALLOC
2851 if ((cachep
->buffer_size
% PAGE_SIZE
) == 0 && OFF_SLAB(cachep
))
2852 kernel_map_pages(virt_to_page(objp
),
2853 cachep
->buffer_size
/ PAGE_SIZE
, 1);
2855 check_poison_obj(cachep
, objp
);
2857 check_poison_obj(cachep
, objp
);
2859 poison_obj(cachep
, objp
, POISON_INUSE
);
2861 if (cachep
->flags
& SLAB_STORE_USER
)
2862 *dbg_userword(cachep
, objp
) = caller
;
2864 if (cachep
->flags
& SLAB_RED_ZONE
) {
2865 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
||
2866 *dbg_redzone2(cachep
, objp
) != RED_INACTIVE
) {
2867 slab_error(cachep
, "double free, or memory outside"
2868 " object was overwritten");
2870 "%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
2871 objp
, *dbg_redzone1(cachep
, objp
),
2872 *dbg_redzone2(cachep
, objp
));
2874 *dbg_redzone1(cachep
, objp
) = RED_ACTIVE
;
2875 *dbg_redzone2(cachep
, objp
) = RED_ACTIVE
;
2877 #ifdef CONFIG_DEBUG_SLAB_LEAK
2882 slabp
= page_get_slab(virt_to_page(objp
));
2883 objnr
= (unsigned)(objp
- slabp
->s_mem
) / cachep
->buffer_size
;
2884 slab_bufctl(slabp
)[objnr
] = BUFCTL_ACTIVE
;
2887 objp
+= obj_offset(cachep
);
2888 if (cachep
->ctor
&& cachep
->flags
& SLAB_POISON
) {
2889 unsigned long ctor_flags
= SLAB_CTOR_CONSTRUCTOR
;
2891 if (!(flags
& __GFP_WAIT
))
2892 ctor_flags
|= SLAB_CTOR_ATOMIC
;
2894 cachep
->ctor(objp
, cachep
, ctor_flags
);
2899 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
2902 static inline void *____cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2905 struct array_cache
*ac
;
2908 if (unlikely(current
->flags
& (PF_SPREAD_SLAB
| PF_MEMPOLICY
))) {
2909 objp
= alternate_node_alloc(cachep
, flags
);
2916 ac
= cpu_cache_get(cachep
);
2917 if (likely(ac
->avail
)) {
2918 STATS_INC_ALLOCHIT(cachep
);
2920 objp
= ac
->entry
[--ac
->avail
];
2922 STATS_INC_ALLOCMISS(cachep
);
2923 objp
= cache_alloc_refill(cachep
, flags
);
2928 static __always_inline
void *__cache_alloc(struct kmem_cache
*cachep
,
2929 gfp_t flags
, void *caller
)
2931 unsigned long save_flags
;
2934 cache_alloc_debugcheck_before(cachep
, flags
);
2936 local_irq_save(save_flags
);
2937 objp
= ____cache_alloc(cachep
, flags
);
2938 local_irq_restore(save_flags
);
2939 objp
= cache_alloc_debugcheck_after(cachep
, flags
, objp
,
2947 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
2949 * If we are in_interrupt, then process context, including cpusets and
2950 * mempolicy, may not apply and should not be used for allocation policy.
2952 static void *alternate_node_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2954 int nid_alloc
, nid_here
;
2958 nid_alloc
= nid_here
= numa_node_id();
2959 if (cpuset_do_slab_mem_spread() && (cachep
->flags
& SLAB_MEM_SPREAD
))
2960 nid_alloc
= cpuset_mem_spread_node();
2961 else if (current
->mempolicy
)
2962 nid_alloc
= slab_node(current
->mempolicy
);
2963 if (nid_alloc
!= nid_here
)
2964 return __cache_alloc_node(cachep
, flags
, nid_alloc
);
2969 * A interface to enable slab creation on nodeid
2971 static void *__cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
,
2974 struct list_head
*entry
;
2976 struct kmem_list3
*l3
;
2980 l3
= cachep
->nodelists
[nodeid
];
2985 spin_lock(&l3
->list_lock
);
2986 entry
= l3
->slabs_partial
.next
;
2987 if (entry
== &l3
->slabs_partial
) {
2988 l3
->free_touched
= 1;
2989 entry
= l3
->slabs_free
.next
;
2990 if (entry
== &l3
->slabs_free
)
2994 slabp
= list_entry(entry
, struct slab
, list
);
2995 check_spinlock_acquired_node(cachep
, nodeid
);
2996 check_slabp(cachep
, slabp
);
2998 STATS_INC_NODEALLOCS(cachep
);
2999 STATS_INC_ACTIVE(cachep
);
3000 STATS_SET_HIGH(cachep
);
3002 BUG_ON(slabp
->inuse
== cachep
->num
);
3004 obj
= slab_get_obj(cachep
, slabp
, nodeid
);
3005 check_slabp(cachep
, slabp
);
3007 /* move slabp to correct slabp list: */
3008 list_del(&slabp
->list
);
3010 if (slabp
->free
== BUFCTL_END
)
3011 list_add(&slabp
->list
, &l3
->slabs_full
);
3013 list_add(&slabp
->list
, &l3
->slabs_partial
);
3015 spin_unlock(&l3
->list_lock
);
3019 spin_unlock(&l3
->list_lock
);
3020 x
= cache_grow(cachep
, flags
, nodeid
);
3032 * Caller needs to acquire correct kmem_list's list_lock
3034 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int nr_objects
,
3038 struct kmem_list3
*l3
;
3040 for (i
= 0; i
< nr_objects
; i
++) {
3041 void *objp
= objpp
[i
];
3044 slabp
= virt_to_slab(objp
);
3045 l3
= cachep
->nodelists
[node
];
3046 list_del(&slabp
->list
);
3047 check_spinlock_acquired_node(cachep
, node
);
3048 check_slabp(cachep
, slabp
);
3049 slab_put_obj(cachep
, slabp
, objp
, node
);
3050 STATS_DEC_ACTIVE(cachep
);
3052 check_slabp(cachep
, slabp
);
3054 /* fixup slab chains */
3055 if (slabp
->inuse
== 0) {
3056 if (l3
->free_objects
> l3
->free_limit
) {
3057 l3
->free_objects
-= cachep
->num
;
3058 slab_destroy(cachep
, slabp
);
3060 list_add(&slabp
->list
, &l3
->slabs_free
);
3063 /* Unconditionally move a slab to the end of the
3064 * partial list on free - maximum time for the
3065 * other objects to be freed, too.
3067 list_add_tail(&slabp
->list
, &l3
->slabs_partial
);
3072 static void cache_flusharray(struct kmem_cache
*cachep
, struct array_cache
*ac
)
3075 struct kmem_list3
*l3
;
3076 int node
= numa_node_id();
3078 batchcount
= ac
->batchcount
;
3080 BUG_ON(!batchcount
|| batchcount
> ac
->avail
);
3083 l3
= cachep
->nodelists
[node
];
3084 spin_lock(&l3
->list_lock
);
3086 struct array_cache
*shared_array
= l3
->shared
;
3087 int max
= shared_array
->limit
- shared_array
->avail
;
3089 if (batchcount
> max
)
3091 memcpy(&(shared_array
->entry
[shared_array
->avail
]),
3092 ac
->entry
, sizeof(void *) * batchcount
);
3093 shared_array
->avail
+= batchcount
;
3098 free_block(cachep
, ac
->entry
, batchcount
, node
);
3103 struct list_head
*p
;
3105 p
= l3
->slabs_free
.next
;
3106 while (p
!= &(l3
->slabs_free
)) {
3109 slabp
= list_entry(p
, struct slab
, list
);
3110 BUG_ON(slabp
->inuse
);
3115 STATS_SET_FREEABLE(cachep
, i
);
3118 spin_unlock(&l3
->list_lock
);
3119 ac
->avail
-= batchcount
;
3120 memmove(ac
->entry
, &(ac
->entry
[batchcount
]), sizeof(void *)*ac
->avail
);
3124 * Release an obj back to its cache. If the obj has a constructed state, it must
3125 * be in this state _before_ it is released. Called with disabled ints.
3127 static inline void __cache_free(struct kmem_cache
*cachep
, void *objp
)
3129 struct array_cache
*ac
= cpu_cache_get(cachep
);
3132 objp
= cache_free_debugcheck(cachep
, objp
, __builtin_return_address(0));
3134 if (cache_free_alien(cachep
, objp
))
3137 if (likely(ac
->avail
< ac
->limit
)) {
3138 STATS_INC_FREEHIT(cachep
);
3139 ac
->entry
[ac
->avail
++] = objp
;
3142 STATS_INC_FREEMISS(cachep
);
3143 cache_flusharray(cachep
, ac
);
3144 ac
->entry
[ac
->avail
++] = objp
;
3149 * kmem_cache_alloc - Allocate an object
3150 * @cachep: The cache to allocate from.
3151 * @flags: See kmalloc().
3153 * Allocate an object from this cache. The flags are only relevant
3154 * if the cache has no available objects.
3156 void *kmem_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3158 return __cache_alloc(cachep
, flags
, __builtin_return_address(0));
3160 EXPORT_SYMBOL(kmem_cache_alloc
);
3163 * kmem_cache_alloc - Allocate an object. The memory is set to zero.
3164 * @cache: The cache to allocate from.
3165 * @flags: See kmalloc().
3167 * Allocate an object from this cache and set the allocated memory to zero.
3168 * The flags are only relevant if the cache has no available objects.
3170 void *kmem_cache_zalloc(struct kmem_cache
*cache
, gfp_t flags
)
3172 void *ret
= __cache_alloc(cache
, flags
, __builtin_return_address(0));
3174 memset(ret
, 0, obj_size(cache
));
3177 EXPORT_SYMBOL(kmem_cache_zalloc
);
3180 * kmem_ptr_validate - check if an untrusted pointer might
3182 * @cachep: the cache we're checking against
3183 * @ptr: pointer to validate
3185 * This verifies that the untrusted pointer looks sane:
3186 * it is _not_ a guarantee that the pointer is actually
3187 * part of the slab cache in question, but it at least
3188 * validates that the pointer can be dereferenced and
3189 * looks half-way sane.
3191 * Currently only used for dentry validation.
3193 int fastcall
kmem_ptr_validate(struct kmem_cache
*cachep
, void *ptr
)
3195 unsigned long addr
= (unsigned long)ptr
;
3196 unsigned long min_addr
= PAGE_OFFSET
;
3197 unsigned long align_mask
= BYTES_PER_WORD
- 1;
3198 unsigned long size
= cachep
->buffer_size
;
3201 if (unlikely(addr
< min_addr
))
3203 if (unlikely(addr
> (unsigned long)high_memory
- size
))
3205 if (unlikely(addr
& align_mask
))
3207 if (unlikely(!kern_addr_valid(addr
)))
3209 if (unlikely(!kern_addr_valid(addr
+ size
- 1)))
3211 page
= virt_to_page(ptr
);
3212 if (unlikely(!PageSlab(page
)))
3214 if (unlikely(page_get_cache(page
) != cachep
))
3223 * kmem_cache_alloc_node - Allocate an object on the specified node
3224 * @cachep: The cache to allocate from.
3225 * @flags: See kmalloc().
3226 * @nodeid: node number of the target node.
3228 * Identical to kmem_cache_alloc, except that this function is slow
3229 * and can sleep. And it will allocate memory on the given node, which
3230 * can improve the performance for cpu bound structures.
3231 * New and improved: it will now make sure that the object gets
3232 * put on the correct node list so that there is no false sharing.
3234 void *kmem_cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
3236 unsigned long save_flags
;
3239 cache_alloc_debugcheck_before(cachep
, flags
);
3240 local_irq_save(save_flags
);
3242 if (nodeid
== -1 || nodeid
== numa_node_id() ||
3243 !cachep
->nodelists
[nodeid
])
3244 ptr
= ____cache_alloc(cachep
, flags
);
3246 ptr
= __cache_alloc_node(cachep
, flags
, nodeid
);
3247 local_irq_restore(save_flags
);
3249 ptr
= cache_alloc_debugcheck_after(cachep
, flags
, ptr
,
3250 __builtin_return_address(0));
3254 EXPORT_SYMBOL(kmem_cache_alloc_node
);
3256 void *kmalloc_node(size_t size
, gfp_t flags
, int node
)
3258 struct kmem_cache
*cachep
;
3260 cachep
= kmem_find_general_cachep(size
, flags
);
3261 if (unlikely(cachep
== NULL
))
3263 return kmem_cache_alloc_node(cachep
, flags
, node
);
3265 EXPORT_SYMBOL(kmalloc_node
);
3269 * kmalloc - allocate memory
3270 * @size: how many bytes of memory are required.
3271 * @flags: the type of memory to allocate.
3272 * @caller: function caller for debug tracking of the caller
3274 * kmalloc is the normal method of allocating memory
3277 * The @flags argument may be one of:
3279 * %GFP_USER - Allocate memory on behalf of user. May sleep.
3281 * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
3283 * %GFP_ATOMIC - Allocation will not sleep. Use inside interrupt handlers.
3285 * Additionally, the %GFP_DMA flag may be set to indicate the memory
3286 * must be suitable for DMA. This can mean different things on different
3287 * platforms. For example, on i386, it means that the memory must come
3288 * from the first 16MB.
3290 static __always_inline
void *__do_kmalloc(size_t size
, gfp_t flags
,
3293 struct kmem_cache
*cachep
;
3295 /* If you want to save a few bytes .text space: replace
3297 * Then kmalloc uses the uninlined functions instead of the inline
3300 cachep
= __find_general_cachep(size
, flags
);
3301 if (unlikely(cachep
== NULL
))
3303 return __cache_alloc(cachep
, flags
, caller
);
3307 void *__kmalloc(size_t size
, gfp_t flags
)
3309 #ifndef CONFIG_DEBUG_SLAB
3310 return __do_kmalloc(size
, flags
, NULL
);
3312 return __do_kmalloc(size
, flags
, __builtin_return_address(0));
3315 EXPORT_SYMBOL(__kmalloc
);
3317 #ifdef CONFIG_DEBUG_SLAB
3318 void *__kmalloc_track_caller(size_t size
, gfp_t flags
, void *caller
)
3320 return __do_kmalloc(size
, flags
, caller
);
3322 EXPORT_SYMBOL(__kmalloc_track_caller
);
3327 * __alloc_percpu - allocate one copy of the object for every present
3328 * cpu in the system, zeroing them.
3329 * Objects should be dereferenced using the per_cpu_ptr macro only.
3331 * @size: how many bytes of memory are required.
3333 void *__alloc_percpu(size_t size
)
3336 struct percpu_data
*pdata
= kmalloc(sizeof(*pdata
), GFP_KERNEL
);
3342 * Cannot use for_each_online_cpu since a cpu may come online
3343 * and we have no way of figuring out how to fix the array
3344 * that we have allocated then....
3346 for_each_possible_cpu(i
) {
3347 int node
= cpu_to_node(i
);
3349 if (node_online(node
))
3350 pdata
->ptrs
[i
] = kmalloc_node(size
, GFP_KERNEL
, node
);
3352 pdata
->ptrs
[i
] = kmalloc(size
, GFP_KERNEL
);
3354 if (!pdata
->ptrs
[i
])
3356 memset(pdata
->ptrs
[i
], 0, size
);
3359 /* Catch derefs w/o wrappers */
3360 return (void *)(~(unsigned long)pdata
);
3364 if (!cpu_possible(i
))
3366 kfree(pdata
->ptrs
[i
]);
3371 EXPORT_SYMBOL(__alloc_percpu
);
3375 * kmem_cache_free - Deallocate an object
3376 * @cachep: The cache the allocation was from.
3377 * @objp: The previously allocated object.
3379 * Free an object which was previously allocated from this
3382 void kmem_cache_free(struct kmem_cache
*cachep
, void *objp
)
3384 unsigned long flags
;
3386 local_irq_save(flags
);
3387 __cache_free(cachep
, objp
);
3388 local_irq_restore(flags
);
3390 EXPORT_SYMBOL(kmem_cache_free
);
3393 * kfree - free previously allocated memory
3394 * @objp: pointer returned by kmalloc.
3396 * If @objp is NULL, no operation is performed.
3398 * Don't free memory not originally allocated by kmalloc()
3399 * or you will run into trouble.
3401 void kfree(const void *objp
)
3403 struct kmem_cache
*c
;
3404 unsigned long flags
;
3406 if (unlikely(!objp
))
3408 local_irq_save(flags
);
3409 kfree_debugcheck(objp
);
3410 c
= virt_to_cache(objp
);
3411 mutex_debug_check_no_locks_freed(objp
, obj_size(c
));
3412 __cache_free(c
, (void *)objp
);
3413 local_irq_restore(flags
);
3415 EXPORT_SYMBOL(kfree
);
3419 * free_percpu - free previously allocated percpu memory
3420 * @objp: pointer returned by alloc_percpu.
3422 * Don't free memory not originally allocated by alloc_percpu()
3423 * The complemented objp is to check for that.
3425 void free_percpu(const void *objp
)
3428 struct percpu_data
*p
= (struct percpu_data
*)(~(unsigned long)objp
);
3431 * We allocate for all cpus so we cannot use for online cpu here.
3433 for_each_possible_cpu(i
)
3437 EXPORT_SYMBOL(free_percpu
);
3440 unsigned int kmem_cache_size(struct kmem_cache
*cachep
)
3442 return obj_size(cachep
);
3444 EXPORT_SYMBOL(kmem_cache_size
);
3446 const char *kmem_cache_name(struct kmem_cache
*cachep
)
3448 return cachep
->name
;
3450 EXPORT_SYMBOL_GPL(kmem_cache_name
);
3453 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3455 static int alloc_kmemlist(struct kmem_cache
*cachep
)
3458 struct kmem_list3
*l3
;
3459 struct array_cache
*new_shared
;
3460 struct array_cache
**new_alien
;
3462 for_each_online_node(node
) {
3464 new_alien
= alloc_alien_cache(node
, cachep
->limit
);
3468 new_shared
= alloc_arraycache(node
,
3469 cachep
->shared
*cachep
->batchcount
,
3472 free_alien_cache(new_alien
);
3476 l3
= cachep
->nodelists
[node
];
3478 struct array_cache
*shared
= l3
->shared
;
3480 spin_lock_irq(&l3
->list_lock
);
3483 free_block(cachep
, shared
->entry
,
3484 shared
->avail
, node
);
3486 l3
->shared
= new_shared
;
3488 l3
->alien
= new_alien
;
3491 l3
->free_limit
= (1 + nr_cpus_node(node
)) *
3492 cachep
->batchcount
+ cachep
->num
;
3493 spin_unlock_irq(&l3
->list_lock
);
3495 free_alien_cache(new_alien
);
3498 l3
= kmalloc_node(sizeof(struct kmem_list3
), GFP_KERNEL
, node
);
3500 free_alien_cache(new_alien
);
3505 kmem_list3_init(l3
);
3506 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
+
3507 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
3508 l3
->shared
= new_shared
;
3509 l3
->alien
= new_alien
;
3510 l3
->free_limit
= (1 + nr_cpus_node(node
)) *
3511 cachep
->batchcount
+ cachep
->num
;
3512 cachep
->nodelists
[node
] = l3
;
3517 if (!cachep
->next
.next
) {
3518 /* Cache is not active yet. Roll back what we did */
3521 if (cachep
->nodelists
[node
]) {
3522 l3
= cachep
->nodelists
[node
];
3525 free_alien_cache(l3
->alien
);
3527 cachep
->nodelists
[node
] = NULL
;
3535 struct ccupdate_struct
{
3536 struct kmem_cache
*cachep
;
3537 struct array_cache
*new[NR_CPUS
];
3540 static void do_ccupdate_local(void *info
)
3542 struct ccupdate_struct
*new = info
;
3543 struct array_cache
*old
;
3546 old
= cpu_cache_get(new->cachep
);
3548 new->cachep
->array
[smp_processor_id()] = new->new[smp_processor_id()];
3549 new->new[smp_processor_id()] = old
;
3552 /* Always called with the cache_chain_mutex held */
3553 static int do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3554 int batchcount
, int shared
)
3556 struct ccupdate_struct
new;
3559 memset(&new.new, 0, sizeof(new.new));
3560 for_each_online_cpu(i
) {
3561 new.new[i
] = alloc_arraycache(cpu_to_node(i
), limit
,
3564 for (i
--; i
>= 0; i
--)
3569 new.cachep
= cachep
;
3571 on_each_cpu(do_ccupdate_local
, (void *)&new, 1, 1);
3574 cachep
->batchcount
= batchcount
;
3575 cachep
->limit
= limit
;
3576 cachep
->shared
= shared
;
3578 for_each_online_cpu(i
) {
3579 struct array_cache
*ccold
= new.new[i
];
3582 spin_lock_irq(&cachep
->nodelists
[cpu_to_node(i
)]->list_lock
);
3583 free_block(cachep
, ccold
->entry
, ccold
->avail
, cpu_to_node(i
));
3584 spin_unlock_irq(&cachep
->nodelists
[cpu_to_node(i
)]->list_lock
);
3588 err
= alloc_kmemlist(cachep
);
3590 printk(KERN_ERR
"alloc_kmemlist failed for %s, error %d.\n",
3591 cachep
->name
, -err
);
3597 /* Called with cache_chain_mutex held always */
3598 static void enable_cpucache(struct kmem_cache
*cachep
)
3604 * The head array serves three purposes:
3605 * - create a LIFO ordering, i.e. return objects that are cache-warm
3606 * - reduce the number of spinlock operations.
3607 * - reduce the number of linked list operations on the slab and
3608 * bufctl chains: array operations are cheaper.
3609 * The numbers are guessed, we should auto-tune as described by
3612 if (cachep
->buffer_size
> 131072)
3614 else if (cachep
->buffer_size
> PAGE_SIZE
)
3616 else if (cachep
->buffer_size
> 1024)
3618 else if (cachep
->buffer_size
> 256)
3624 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3625 * allocation behaviour: Most allocs on one cpu, most free operations
3626 * on another cpu. For these cases, an efficient object passing between
3627 * cpus is necessary. This is provided by a shared array. The array
3628 * replaces Bonwick's magazine layer.
3629 * On uniprocessor, it's functionally equivalent (but less efficient)
3630 * to a larger limit. Thus disabled by default.
3634 if (cachep
->buffer_size
<= PAGE_SIZE
)
3640 * With debugging enabled, large batchcount lead to excessively long
3641 * periods with disabled local interrupts. Limit the batchcount
3646 err
= do_tune_cpucache(cachep
, limit
, (limit
+ 1) / 2, shared
);
3648 printk(KERN_ERR
"enable_cpucache failed for %s, error %d.\n",
3649 cachep
->name
, -err
);
3653 * Drain an array if it contains any elements taking the l3 lock only if
3654 * necessary. Note that the l3 listlock also protects the array_cache
3655 * if drain_array() is used on the shared array.
3657 void drain_array(struct kmem_cache
*cachep
, struct kmem_list3
*l3
,
3658 struct array_cache
*ac
, int force
, int node
)
3662 if (!ac
|| !ac
->avail
)
3664 if (ac
->touched
&& !force
) {
3667 spin_lock_irq(&l3
->list_lock
);
3669 tofree
= force
? ac
->avail
: (ac
->limit
+ 4) / 5;
3670 if (tofree
> ac
->avail
)
3671 tofree
= (ac
->avail
+ 1) / 2;
3672 free_block(cachep
, ac
->entry
, tofree
, node
);
3673 ac
->avail
-= tofree
;
3674 memmove(ac
->entry
, &(ac
->entry
[tofree
]),
3675 sizeof(void *) * ac
->avail
);
3677 spin_unlock_irq(&l3
->list_lock
);
3682 * cache_reap - Reclaim memory from caches.
3683 * @unused: unused parameter
3685 * Called from workqueue/eventd every few seconds.
3687 * - clear the per-cpu caches for this CPU.
3688 * - return freeable pages to the main free memory pool.
3690 * If we cannot acquire the cache chain mutex then just give up - we'll try
3691 * again on the next iteration.
3693 static void cache_reap(void *unused
)
3695 struct list_head
*walk
;
3696 struct kmem_list3
*l3
;
3697 int node
= numa_node_id();
3699 if (!mutex_trylock(&cache_chain_mutex
)) {
3700 /* Give up. Setup the next iteration. */
3701 schedule_delayed_work(&__get_cpu_var(reap_work
),
3706 list_for_each(walk
, &cache_chain
) {
3707 struct kmem_cache
*searchp
;
3708 struct list_head
*p
;
3712 searchp
= list_entry(walk
, struct kmem_cache
, next
);
3716 * We only take the l3 lock if absolutely necessary and we
3717 * have established with reasonable certainty that
3718 * we can do some work if the lock was obtained.
3720 l3
= searchp
->nodelists
[node
];
3722 reap_alien(searchp
, l3
);
3724 drain_array(searchp
, l3
, cpu_cache_get(searchp
), 0, node
);
3727 * These are racy checks but it does not matter
3728 * if we skip one check or scan twice.
3730 if (time_after(l3
->next_reap
, jiffies
))
3733 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
;
3735 drain_array(searchp
, l3
, l3
->shared
, 0, node
);
3737 if (l3
->free_touched
) {
3738 l3
->free_touched
= 0;
3742 tofree
= (l3
->free_limit
+ 5 * searchp
->num
- 1) /
3746 * Do not lock if there are no free blocks.
3748 if (list_empty(&l3
->slabs_free
))
3751 spin_lock_irq(&l3
->list_lock
);
3752 p
= l3
->slabs_free
.next
;
3753 if (p
== &(l3
->slabs_free
)) {
3754 spin_unlock_irq(&l3
->list_lock
);
3758 slabp
= list_entry(p
, struct slab
, list
);
3759 BUG_ON(slabp
->inuse
);
3760 list_del(&slabp
->list
);
3761 STATS_INC_REAPED(searchp
);
3764 * Safe to drop the lock. The slab is no longer linked
3765 * to the cache. searchp cannot disappear, we hold
3768 l3
->free_objects
-= searchp
->num
;
3769 spin_unlock_irq(&l3
->list_lock
);
3770 slab_destroy(searchp
, slabp
);
3771 } while (--tofree
> 0);
3776 mutex_unlock(&cache_chain_mutex
);
3778 /* Set up the next iteration */
3779 schedule_delayed_work(&__get_cpu_var(reap_work
), REAPTIMEOUT_CPUC
);
3782 #ifdef CONFIG_PROC_FS
3784 static void print_slabinfo_header(struct seq_file
*m
)
3787 * Output format version, so at least we can change it
3788 * without _too_ many complaints.
3791 seq_puts(m
, "slabinfo - version: 2.1 (statistics)\n");
3793 seq_puts(m
, "slabinfo - version: 2.1\n");
3795 seq_puts(m
, "# name <active_objs> <num_objs> <objsize> "
3796 "<objperslab> <pagesperslab>");
3797 seq_puts(m
, " : tunables <limit> <batchcount> <sharedfactor>");
3798 seq_puts(m
, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
3800 seq_puts(m
, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
3801 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
3802 seq_puts(m
, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
3807 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
3810 struct list_head
*p
;
3812 mutex_lock(&cache_chain_mutex
);
3814 print_slabinfo_header(m
);
3815 p
= cache_chain
.next
;
3818 if (p
== &cache_chain
)
3821 return list_entry(p
, struct kmem_cache
, next
);
3824 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
3826 struct kmem_cache
*cachep
= p
;
3828 return cachep
->next
.next
== &cache_chain
?
3829 NULL
: list_entry(cachep
->next
.next
, struct kmem_cache
, next
);
3832 static void s_stop(struct seq_file
*m
, void *p
)
3834 mutex_unlock(&cache_chain_mutex
);
3837 static int s_show(struct seq_file
*m
, void *p
)
3839 struct kmem_cache
*cachep
= p
;
3840 struct list_head
*q
;
3842 unsigned long active_objs
;
3843 unsigned long num_objs
;
3844 unsigned long active_slabs
= 0;
3845 unsigned long num_slabs
, free_objects
= 0, shared_avail
= 0;
3849 struct kmem_list3
*l3
;
3853 for_each_online_node(node
) {
3854 l3
= cachep
->nodelists
[node
];
3859 spin_lock_irq(&l3
->list_lock
);
3861 list_for_each(q
, &l3
->slabs_full
) {
3862 slabp
= list_entry(q
, struct slab
, list
);
3863 if (slabp
->inuse
!= cachep
->num
&& !error
)
3864 error
= "slabs_full accounting error";
3865 active_objs
+= cachep
->num
;
3868 list_for_each(q
, &l3
->slabs_partial
) {
3869 slabp
= list_entry(q
, struct slab
, list
);
3870 if (slabp
->inuse
== cachep
->num
&& !error
)
3871 error
= "slabs_partial inuse accounting error";
3872 if (!slabp
->inuse
&& !error
)
3873 error
= "slabs_partial/inuse accounting error";
3874 active_objs
+= slabp
->inuse
;
3877 list_for_each(q
, &l3
->slabs_free
) {
3878 slabp
= list_entry(q
, struct slab
, list
);
3879 if (slabp
->inuse
&& !error
)
3880 error
= "slabs_free/inuse accounting error";
3883 free_objects
+= l3
->free_objects
;
3885 shared_avail
+= l3
->shared
->avail
;
3887 spin_unlock_irq(&l3
->list_lock
);
3889 num_slabs
+= active_slabs
;
3890 num_objs
= num_slabs
* cachep
->num
;
3891 if (num_objs
- active_objs
!= free_objects
&& !error
)
3892 error
= "free_objects accounting error";
3894 name
= cachep
->name
;
3896 printk(KERN_ERR
"slab: cache %s error: %s\n", name
, error
);
3898 seq_printf(m
, "%-17s %6lu %6lu %6u %4u %4d",
3899 name
, active_objs
, num_objs
, cachep
->buffer_size
,
3900 cachep
->num
, (1 << cachep
->gfporder
));
3901 seq_printf(m
, " : tunables %4u %4u %4u",
3902 cachep
->limit
, cachep
->batchcount
, cachep
->shared
);
3903 seq_printf(m
, " : slabdata %6lu %6lu %6lu",
3904 active_slabs
, num_slabs
, shared_avail
);
3907 unsigned long high
= cachep
->high_mark
;
3908 unsigned long allocs
= cachep
->num_allocations
;
3909 unsigned long grown
= cachep
->grown
;
3910 unsigned long reaped
= cachep
->reaped
;
3911 unsigned long errors
= cachep
->errors
;
3912 unsigned long max_freeable
= cachep
->max_freeable
;
3913 unsigned long node_allocs
= cachep
->node_allocs
;
3914 unsigned long node_frees
= cachep
->node_frees
;
3915 unsigned long overflows
= cachep
->node_overflow
;
3917 seq_printf(m
, " : globalstat %7lu %6lu %5lu %4lu \
3918 %4lu %4lu %4lu %4lu %4lu", allocs
, high
, grown
,
3919 reaped
, errors
, max_freeable
, node_allocs
,
3920 node_frees
, overflows
);
3924 unsigned long allochit
= atomic_read(&cachep
->allochit
);
3925 unsigned long allocmiss
= atomic_read(&cachep
->allocmiss
);
3926 unsigned long freehit
= atomic_read(&cachep
->freehit
);
3927 unsigned long freemiss
= atomic_read(&cachep
->freemiss
);
3929 seq_printf(m
, " : cpustat %6lu %6lu %6lu %6lu",
3930 allochit
, allocmiss
, freehit
, freemiss
);
3938 * slabinfo_op - iterator that generates /proc/slabinfo
3947 * num-pages-per-slab
3948 * + further values on SMP and with statistics enabled
3951 struct seq_operations slabinfo_op
= {
3958 #define MAX_SLABINFO_WRITE 128
3960 * slabinfo_write - Tuning for the slab allocator
3962 * @buffer: user buffer
3963 * @count: data length
3966 ssize_t
slabinfo_write(struct file
*file
, const char __user
* buffer
,
3967 size_t count
, loff_t
*ppos
)
3969 char kbuf
[MAX_SLABINFO_WRITE
+ 1], *tmp
;
3970 int limit
, batchcount
, shared
, res
;
3971 struct list_head
*p
;
3973 if (count
> MAX_SLABINFO_WRITE
)
3975 if (copy_from_user(&kbuf
, buffer
, count
))
3977 kbuf
[MAX_SLABINFO_WRITE
] = '\0';
3979 tmp
= strchr(kbuf
, ' ');
3984 if (sscanf(tmp
, " %d %d %d", &limit
, &batchcount
, &shared
) != 3)
3987 /* Find the cache in the chain of caches. */
3988 mutex_lock(&cache_chain_mutex
);
3990 list_for_each(p
, &cache_chain
) {
3991 struct kmem_cache
*cachep
;
3993 cachep
= list_entry(p
, struct kmem_cache
, next
);
3994 if (!strcmp(cachep
->name
, kbuf
)) {
3995 if (limit
< 1 || batchcount
< 1 ||
3996 batchcount
> limit
|| shared
< 0) {
3999 res
= do_tune_cpucache(cachep
, limit
,
4000 batchcount
, shared
);
4005 mutex_unlock(&cache_chain_mutex
);
4011 #ifdef CONFIG_DEBUG_SLAB_LEAK
4013 static void *leaks_start(struct seq_file
*m
, loff_t
*pos
)
4016 struct list_head
*p
;
4018 mutex_lock(&cache_chain_mutex
);
4019 p
= cache_chain
.next
;
4022 if (p
== &cache_chain
)
4025 return list_entry(p
, struct kmem_cache
, next
);
4028 static inline int add_caller(unsigned long *n
, unsigned long v
)
4038 unsigned long *q
= p
+ 2 * i
;
4052 memmove(p
+ 2, p
, n
[1] * 2 * sizeof(unsigned long) - ((void *)p
- (void *)n
));
4058 static void handle_slab(unsigned long *n
, struct kmem_cache
*c
, struct slab
*s
)
4064 for (i
= 0, p
= s
->s_mem
; i
< c
->num
; i
++, p
+= c
->buffer_size
) {
4065 if (slab_bufctl(s
)[i
] != BUFCTL_ACTIVE
)
4067 if (!add_caller(n
, (unsigned long)*dbg_userword(c
, p
)))
4072 static void show_symbol(struct seq_file
*m
, unsigned long address
)
4074 #ifdef CONFIG_KALLSYMS
4077 unsigned long offset
, size
;
4078 char namebuf
[KSYM_NAME_LEN
+1];
4080 name
= kallsyms_lookup(address
, &size
, &offset
, &modname
, namebuf
);
4083 seq_printf(m
, "%s+%#lx/%#lx", name
, offset
, size
);
4085 seq_printf(m
, " [%s]", modname
);
4089 seq_printf(m
, "%p", (void *)address
);
4092 static int leaks_show(struct seq_file
*m
, void *p
)
4094 struct kmem_cache
*cachep
= p
;
4095 struct list_head
*q
;
4097 struct kmem_list3
*l3
;
4099 unsigned long *n
= m
->private;
4103 if (!(cachep
->flags
& SLAB_STORE_USER
))
4105 if (!(cachep
->flags
& SLAB_RED_ZONE
))
4108 /* OK, we can do it */
4112 for_each_online_node(node
) {
4113 l3
= cachep
->nodelists
[node
];
4118 spin_lock_irq(&l3
->list_lock
);
4120 list_for_each(q
, &l3
->slabs_full
) {
4121 slabp
= list_entry(q
, struct slab
, list
);
4122 handle_slab(n
, cachep
, slabp
);
4124 list_for_each(q
, &l3
->slabs_partial
) {
4125 slabp
= list_entry(q
, struct slab
, list
);
4126 handle_slab(n
, cachep
, slabp
);
4128 spin_unlock_irq(&l3
->list_lock
);
4130 name
= cachep
->name
;
4132 /* Increase the buffer size */
4133 mutex_unlock(&cache_chain_mutex
);
4134 m
->private = kzalloc(n
[0] * 4 * sizeof(unsigned long), GFP_KERNEL
);
4136 /* Too bad, we are really out */
4138 mutex_lock(&cache_chain_mutex
);
4141 *(unsigned long *)m
->private = n
[0] * 2;
4143 mutex_lock(&cache_chain_mutex
);
4144 /* Now make sure this entry will be retried */
4148 for (i
= 0; i
< n
[1]; i
++) {
4149 seq_printf(m
, "%s: %lu ", name
, n
[2*i
+3]);
4150 show_symbol(m
, n
[2*i
+2]);
4156 struct seq_operations slabstats_op
= {
4157 .start
= leaks_start
,
4166 * ksize - get the actual amount of memory allocated for a given object
4167 * @objp: Pointer to the object
4169 * kmalloc may internally round up allocations and return more memory
4170 * than requested. ksize() can be used to determine the actual amount of
4171 * memory allocated. The caller may use this additional memory, even though
4172 * a smaller amount of memory was initially specified with the kmalloc call.
4173 * The caller must guarantee that objp points to a valid object previously
4174 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4175 * must not be freed during the duration of the call.
4177 unsigned int ksize(const void *objp
)
4179 if (unlikely(objp
== NULL
))
4182 return obj_size(virt_to_cache(objp
));