3 * Written by Mark Hemment, 1996/97.
4 * (markhe@nextd.demon.co.uk)
6 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
8 * Major cleanup, different bufctl logic, per-cpu arrays
9 * (c) 2000 Manfred Spraul
11 * Cleanup, make the head arrays unconditional, preparation for NUMA
12 * (c) 2002 Manfred Spraul
14 * An implementation of the Slab Allocator as described in outline in;
15 * UNIX Internals: The New Frontiers by Uresh Vahalia
16 * Pub: Prentice Hall ISBN 0-13-101908-2
17 * or with a little more detail in;
18 * The Slab Allocator: An Object-Caching Kernel Memory Allocator
19 * Jeff Bonwick (Sun Microsystems).
20 * Presented at: USENIX Summer 1994 Technical Conference
22 * The memory is organized in caches, one cache for each object type.
23 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
24 * Each cache consists out of many slabs (they are small (usually one
25 * page long) and always contiguous), and each slab contains multiple
26 * initialized objects.
28 * This means, that your constructor is used only for newly allocated
29 * slabs and you must pass objects with the same intializations to
32 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
33 * normal). If you need a special memory type, then must create a new
34 * cache for that memory type.
36 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
37 * full slabs with 0 free objects
39 * empty slabs with no allocated objects
41 * If partial slabs exist, then new allocations come from these slabs,
42 * otherwise from empty slabs or new slabs are allocated.
44 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
45 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
47 * Each cache has a short per-cpu head array, most allocs
48 * and frees go into that array, and if that array overflows, then 1/2
49 * of the entries in the array are given back into the global cache.
50 * The head array is strictly LIFO and should improve the cache hit rates.
51 * On SMP, it additionally reduces the spinlock operations.
53 * The c_cpuarray may not be read with enabled local interrupts -
54 * it's changed with a smp_call_function().
56 * SMP synchronization:
57 * constructors and destructors are called without any locking.
58 * Several members in struct kmem_cache and struct slab never change, they
59 * are accessed without any locking.
60 * The per-cpu arrays are never accessed from the wrong cpu, no locking,
61 * and local interrupts are disabled so slab code is preempt-safe.
62 * The non-constant members are protected with a per-cache irq spinlock.
64 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
65 * in 2000 - many ideas in the current implementation are derived from
68 * Further notes from the original documentation:
70 * 11 April '97. Started multi-threading - markhe
71 * The global cache-chain is protected by the mutex 'cache_chain_mutex'.
72 * The sem is only needed when accessing/extending the cache-chain, which
73 * can never happen inside an interrupt (kmem_cache_create(),
74 * kmem_cache_shrink() and kmem_cache_reap()).
76 * At present, each engine can be growing a cache. This should be blocked.
78 * 15 March 2005. NUMA slab allocator.
79 * Shai Fultheim <shai@scalex86.org>.
80 * Shobhit Dayal <shobhit@calsoftinc.com>
81 * Alok N Kataria <alokk@calsoftinc.com>
82 * Christoph Lameter <christoph@lameter.com>
84 * Modified the slab allocator to be node aware on NUMA systems.
85 * Each node has its own list of partial, free and full slabs.
86 * All object allocations for a node occur from node specific slab lists.
89 #include <linux/config.h>
90 #include <linux/slab.h>
92 #include <linux/poison.h>
93 #include <linux/swap.h>
94 #include <linux/cache.h>
95 #include <linux/interrupt.h>
96 #include <linux/init.h>
97 #include <linux/compiler.h>
98 #include <linux/cpuset.h>
99 #include <linux/seq_file.h>
100 #include <linux/notifier.h>
101 #include <linux/kallsyms.h>
102 #include <linux/cpu.h>
103 #include <linux/sysctl.h>
104 #include <linux/module.h>
105 #include <linux/rcupdate.h>
106 #include <linux/string.h>
107 #include <linux/nodemask.h>
108 #include <linux/mempolicy.h>
109 #include <linux/mutex.h>
111 #include <asm/uaccess.h>
112 #include <asm/cacheflush.h>
113 #include <asm/tlbflush.h>
114 #include <asm/page.h>
117 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL,
118 * SLAB_RED_ZONE & SLAB_POISON.
119 * 0 for faster, smaller code (especially in the critical paths).
121 * STATS - 1 to collect stats for /proc/slabinfo.
122 * 0 for faster, smaller code (especially in the critical paths).
124 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
127 #ifdef CONFIG_DEBUG_SLAB
130 #define FORCED_DEBUG 1
134 #define FORCED_DEBUG 0
137 /* Shouldn't this be in a header file somewhere? */
138 #define BYTES_PER_WORD sizeof(void *)
140 #ifndef cache_line_size
141 #define cache_line_size() L1_CACHE_BYTES
144 #ifndef ARCH_KMALLOC_MINALIGN
146 * Enforce a minimum alignment for the kmalloc caches.
147 * Usually, the kmalloc caches are cache_line_size() aligned, except when
148 * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned.
149 * Some archs want to perform DMA into kmalloc caches and need a guaranteed
150 * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that.
151 * Note that this flag disables some debug features.
153 #define ARCH_KMALLOC_MINALIGN 0
156 #ifndef ARCH_SLAB_MINALIGN
158 * Enforce a minimum alignment for all caches.
159 * Intended for archs that get misalignment faults even for BYTES_PER_WORD
160 * aligned buffers. Includes ARCH_KMALLOC_MINALIGN.
161 * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables
162 * some debug features.
164 #define ARCH_SLAB_MINALIGN 0
167 #ifndef ARCH_KMALLOC_FLAGS
168 #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
171 /* Legal flag mask for kmem_cache_create(). */
173 # define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \
174 SLAB_POISON | SLAB_HWCACHE_ALIGN | \
176 SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \
177 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
178 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
180 # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
181 SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \
182 SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
183 SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
189 * Bufctl's are used for linking objs within a slab
192 * This implementation relies on "struct page" for locating the cache &
193 * slab an object belongs to.
194 * This allows the bufctl structure to be small (one int), but limits
195 * the number of objects a slab (not a cache) can contain when off-slab
196 * bufctls are used. The limit is the size of the largest general cache
197 * that does not use off-slab slabs.
198 * For 32bit archs with 4 kB pages, is this 56.
199 * This is not serious, as it is only for large objects, when it is unwise
200 * to have too many per slab.
201 * Note: This limit can be raised by introducing a general cache whose size
202 * is less than 512 (PAGE_SIZE<<3), but greater than 256.
205 typedef unsigned int kmem_bufctl_t
;
206 #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0)
207 #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1)
208 #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2)
209 #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3)
214 * Manages the objs in a slab. Placed either at the beginning of mem allocated
215 * for a slab, or allocated from an general cache.
216 * Slabs are chained into three list: fully used, partial, fully free slabs.
219 struct list_head list
;
220 unsigned long colouroff
;
221 void *s_mem
; /* including colour offset */
222 unsigned int inuse
; /* num of objs active in slab */
224 unsigned short nodeid
;
230 * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
231 * arrange for kmem_freepages to be called via RCU. This is useful if
232 * we need to approach a kernel structure obliquely, from its address
233 * obtained without the usual locking. We can lock the structure to
234 * stabilize it and check it's still at the given address, only if we
235 * can be sure that the memory has not been meanwhile reused for some
236 * other kind of object (which our subsystem's lock might corrupt).
238 * rcu_read_lock before reading the address, then rcu_read_unlock after
239 * taking the spinlock within the structure expected at that address.
241 * We assume struct slab_rcu can overlay struct slab when destroying.
244 struct rcu_head head
;
245 struct kmem_cache
*cachep
;
253 * - LIFO ordering, to hand out cache-warm objects from _alloc
254 * - reduce the number of linked list operations
255 * - reduce spinlock operations
257 * The limit is stored in the per-cpu structure to reduce the data cache
264 unsigned int batchcount
;
265 unsigned int touched
;
268 * Must have this definition in here for the proper
269 * alignment of array_cache. Also simplifies accessing
271 * [0] is for gcc 2.95. It should really be [].
276 * bootstrap: The caches do not work without cpuarrays anymore, but the
277 * cpuarrays are allocated from the generic caches...
279 #define BOOT_CPUCACHE_ENTRIES 1
280 struct arraycache_init
{
281 struct array_cache cache
;
282 void *entries
[BOOT_CPUCACHE_ENTRIES
];
286 * The slab lists for all objects.
289 struct list_head slabs_partial
; /* partial list first, better asm code */
290 struct list_head slabs_full
;
291 struct list_head slabs_free
;
292 unsigned long free_objects
;
293 unsigned int free_limit
;
294 unsigned int colour_next
; /* Per-node cache coloring */
295 spinlock_t list_lock
;
296 struct array_cache
*shared
; /* shared per node */
297 struct array_cache
**alien
; /* on other nodes */
298 unsigned long next_reap
; /* updated without locking */
299 int free_touched
; /* updated without locking */
303 * Need this for bootstrapping a per node allocator.
305 #define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
306 struct kmem_list3 __initdata initkmem_list3
[NUM_INIT_LISTS
];
307 #define CACHE_CACHE 0
309 #define SIZE_L3 (1 + MAX_NUMNODES)
312 * This function must be completely optimized away if a constant is passed to
313 * it. Mostly the same as what is in linux/slab.h except it returns an index.
315 static __always_inline
int index_of(const size_t size
)
317 extern void __bad_size(void);
319 if (__builtin_constant_p(size
)) {
327 #include "linux/kmalloc_sizes.h"
335 static int slab_early_init
= 1;
337 #define INDEX_AC index_of(sizeof(struct arraycache_init))
338 #define INDEX_L3 index_of(sizeof(struct kmem_list3))
340 static void kmem_list3_init(struct kmem_list3
*parent
)
342 INIT_LIST_HEAD(&parent
->slabs_full
);
343 INIT_LIST_HEAD(&parent
->slabs_partial
);
344 INIT_LIST_HEAD(&parent
->slabs_free
);
345 parent
->shared
= NULL
;
346 parent
->alien
= NULL
;
347 parent
->colour_next
= 0;
348 spin_lock_init(&parent
->list_lock
);
349 parent
->free_objects
= 0;
350 parent
->free_touched
= 0;
353 #define MAKE_LIST(cachep, listp, slab, nodeid) \
355 INIT_LIST_HEAD(listp); \
356 list_splice(&(cachep->nodelists[nodeid]->slab), listp); \
359 #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
361 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
362 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
363 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
373 /* 1) per-cpu data, touched during every alloc/free */
374 struct array_cache
*array
[NR_CPUS
];
375 /* 2) Cache tunables. Protected by cache_chain_mutex */
376 unsigned int batchcount
;
380 unsigned int buffer_size
;
381 /* 3) touched by every alloc & free from the backend */
382 struct kmem_list3
*nodelists
[MAX_NUMNODES
];
384 unsigned int flags
; /* constant flags */
385 unsigned int num
; /* # of objs per slab */
387 /* 4) cache_grow/shrink */
388 /* order of pgs per slab (2^n) */
389 unsigned int gfporder
;
391 /* force GFP flags, e.g. GFP_DMA */
394 size_t colour
; /* cache colouring range */
395 unsigned int colour_off
; /* colour offset */
396 struct kmem_cache
*slabp_cache
;
397 unsigned int slab_size
;
398 unsigned int dflags
; /* dynamic flags */
400 /* constructor func */
401 void (*ctor
) (void *, struct kmem_cache
*, unsigned long);
403 /* de-constructor func */
404 void (*dtor
) (void *, struct kmem_cache
*, unsigned long);
406 /* 5) cache creation/removal */
408 struct list_head next
;
412 unsigned long num_active
;
413 unsigned long num_allocations
;
414 unsigned long high_mark
;
416 unsigned long reaped
;
417 unsigned long errors
;
418 unsigned long max_freeable
;
419 unsigned long node_allocs
;
420 unsigned long node_frees
;
421 unsigned long node_overflow
;
429 * If debugging is enabled, then the allocator can add additional
430 * fields and/or padding to every object. buffer_size contains the total
431 * object size including these internal fields, the following two
432 * variables contain the offset to the user object and its size.
439 #define CFLGS_OFF_SLAB (0x80000000UL)
440 #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
442 #define BATCHREFILL_LIMIT 16
444 * Optimization question: fewer reaps means less probability for unnessary
445 * cpucache drain/refill cycles.
447 * OTOH the cpuarrays can contain lots of objects,
448 * which could lock up otherwise freeable slabs.
450 #define REAPTIMEOUT_CPUC (2*HZ)
451 #define REAPTIMEOUT_LIST3 (4*HZ)
454 #define STATS_INC_ACTIVE(x) ((x)->num_active++)
455 #define STATS_DEC_ACTIVE(x) ((x)->num_active--)
456 #define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
457 #define STATS_INC_GROWN(x) ((x)->grown++)
458 #define STATS_INC_REAPED(x) ((x)->reaped++)
459 #define STATS_SET_HIGH(x) \
461 if ((x)->num_active > (x)->high_mark) \
462 (x)->high_mark = (x)->num_active; \
464 #define STATS_INC_ERR(x) ((x)->errors++)
465 #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
466 #define STATS_INC_NODEFREES(x) ((x)->node_frees++)
467 #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
468 #define STATS_SET_FREEABLE(x, i) \
470 if ((x)->max_freeable < i) \
471 (x)->max_freeable = i; \
473 #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
474 #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
475 #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
476 #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
478 #define STATS_INC_ACTIVE(x) do { } while (0)
479 #define STATS_DEC_ACTIVE(x) do { } while (0)
480 #define STATS_INC_ALLOCED(x) do { } while (0)
481 #define STATS_INC_GROWN(x) do { } while (0)
482 #define STATS_INC_REAPED(x) do { } while (0)
483 #define STATS_SET_HIGH(x) do { } while (0)
484 #define STATS_INC_ERR(x) do { } while (0)
485 #define STATS_INC_NODEALLOCS(x) do { } while (0)
486 #define STATS_INC_NODEFREES(x) do { } while (0)
487 #define STATS_INC_ACOVERFLOW(x) do { } while (0)
488 #define STATS_SET_FREEABLE(x, i) do { } while (0)
489 #define STATS_INC_ALLOCHIT(x) do { } while (0)
490 #define STATS_INC_ALLOCMISS(x) do { } while (0)
491 #define STATS_INC_FREEHIT(x) do { } while (0)
492 #define STATS_INC_FREEMISS(x) do { } while (0)
498 * memory layout of objects:
500 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
501 * the end of an object is aligned with the end of the real
502 * allocation. Catches writes behind the end of the allocation.
503 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
505 * cachep->obj_offset: The real object.
506 * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
507 * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address
508 * [BYTES_PER_WORD long]
510 static int obj_offset(struct kmem_cache
*cachep
)
512 return cachep
->obj_offset
;
515 static int obj_size(struct kmem_cache
*cachep
)
517 return cachep
->obj_size
;
520 static unsigned long *dbg_redzone1(struct kmem_cache
*cachep
, void *objp
)
522 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
523 return (unsigned long*) (objp
+obj_offset(cachep
)-BYTES_PER_WORD
);
526 static unsigned long *dbg_redzone2(struct kmem_cache
*cachep
, void *objp
)
528 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
529 if (cachep
->flags
& SLAB_STORE_USER
)
530 return (unsigned long *)(objp
+ cachep
->buffer_size
-
532 return (unsigned long *)(objp
+ cachep
->buffer_size
- BYTES_PER_WORD
);
535 static void **dbg_userword(struct kmem_cache
*cachep
, void *objp
)
537 BUG_ON(!(cachep
->flags
& SLAB_STORE_USER
));
538 return (void **)(objp
+ cachep
->buffer_size
- BYTES_PER_WORD
);
543 #define obj_offset(x) 0
544 #define obj_size(cachep) (cachep->buffer_size)
545 #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;})
546 #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;})
547 #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
552 * Maximum size of an obj (in 2^order pages) and absolute limit for the gfp
555 #if defined(CONFIG_LARGE_ALLOCS)
556 #define MAX_OBJ_ORDER 13 /* up to 32Mb */
557 #define MAX_GFP_ORDER 13 /* up to 32Mb */
558 #elif defined(CONFIG_MMU)
559 #define MAX_OBJ_ORDER 5 /* 32 pages */
560 #define MAX_GFP_ORDER 5 /* 32 pages */
562 #define MAX_OBJ_ORDER 8 /* up to 1Mb */
563 #define MAX_GFP_ORDER 8 /* up to 1Mb */
567 * Do not go above this order unless 0 objects fit into the slab.
569 #define BREAK_GFP_ORDER_HI 1
570 #define BREAK_GFP_ORDER_LO 0
571 static int slab_break_gfp_order
= BREAK_GFP_ORDER_LO
;
574 * Functions for storing/retrieving the cachep and or slab from the page
575 * allocator. These are used to find the slab an obj belongs to. With kfree(),
576 * these are used to find the cache which an obj belongs to.
578 static inline void page_set_cache(struct page
*page
, struct kmem_cache
*cache
)
580 page
->lru
.next
= (struct list_head
*)cache
;
583 static inline struct kmem_cache
*page_get_cache(struct page
*page
)
585 if (unlikely(PageCompound(page
)))
586 page
= (struct page
*)page_private(page
);
587 BUG_ON(!PageSlab(page
));
588 return (struct kmem_cache
*)page
->lru
.next
;
591 static inline void page_set_slab(struct page
*page
, struct slab
*slab
)
593 page
->lru
.prev
= (struct list_head
*)slab
;
596 static inline struct slab
*page_get_slab(struct page
*page
)
598 if (unlikely(PageCompound(page
)))
599 page
= (struct page
*)page_private(page
);
600 BUG_ON(!PageSlab(page
));
601 return (struct slab
*)page
->lru
.prev
;
604 static inline struct kmem_cache
*virt_to_cache(const void *obj
)
606 struct page
*page
= virt_to_page(obj
);
607 return page_get_cache(page
);
610 static inline struct slab
*virt_to_slab(const void *obj
)
612 struct page
*page
= virt_to_page(obj
);
613 return page_get_slab(page
);
616 static inline void *index_to_obj(struct kmem_cache
*cache
, struct slab
*slab
,
619 return slab
->s_mem
+ cache
->buffer_size
* idx
;
622 static inline unsigned int obj_to_index(struct kmem_cache
*cache
,
623 struct slab
*slab
, void *obj
)
625 return (unsigned)(obj
- slab
->s_mem
) / cache
->buffer_size
;
629 * These are the default caches for kmalloc. Custom caches can have other sizes.
631 struct cache_sizes malloc_sizes
[] = {
632 #define CACHE(x) { .cs_size = (x) },
633 #include <linux/kmalloc_sizes.h>
637 EXPORT_SYMBOL(malloc_sizes
);
639 /* Must match cache_sizes above. Out of line to keep cache footprint low. */
645 static struct cache_names __initdata cache_names
[] = {
646 #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" },
647 #include <linux/kmalloc_sizes.h>
652 static struct arraycache_init initarray_cache __initdata
=
653 { {0, BOOT_CPUCACHE_ENTRIES
, 1, 0} };
654 static struct arraycache_init initarray_generic
=
655 { {0, BOOT_CPUCACHE_ENTRIES
, 1, 0} };
657 /* internal cache of cache description objs */
658 static struct kmem_cache cache_cache
= {
660 .limit
= BOOT_CPUCACHE_ENTRIES
,
662 .buffer_size
= sizeof(struct kmem_cache
),
663 .name
= "kmem_cache",
665 .obj_size
= sizeof(struct kmem_cache
),
669 /* Guard access to the cache-chain. */
670 static DEFINE_MUTEX(cache_chain_mutex
);
671 static struct list_head cache_chain
;
674 * vm_enough_memory() looks at this to determine how many slab-allocated pages
675 * are possibly freeable under pressure
677 * SLAB_RECLAIM_ACCOUNT turns this on per-slab
679 atomic_t slab_reclaim_pages
;
682 * chicken and egg problem: delay the per-cpu array allocation
683 * until the general caches are up.
693 * used by boot code to determine if it can use slab based allocator
695 int slab_is_available(void)
697 return g_cpucache_up
== FULL
;
700 static DEFINE_PER_CPU(struct work_struct
, reap_work
);
702 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int len
,
704 static void enable_cpucache(struct kmem_cache
*cachep
);
705 static void cache_reap(void *unused
);
706 static int __node_shrink(struct kmem_cache
*cachep
, int node
);
708 static inline struct array_cache
*cpu_cache_get(struct kmem_cache
*cachep
)
710 return cachep
->array
[smp_processor_id()];
713 static inline struct kmem_cache
*__find_general_cachep(size_t size
,
716 struct cache_sizes
*csizep
= malloc_sizes
;
719 /* This happens if someone tries to call
720 * kmem_cache_create(), or __kmalloc(), before
721 * the generic caches are initialized.
723 BUG_ON(malloc_sizes
[INDEX_AC
].cs_cachep
== NULL
);
725 while (size
> csizep
->cs_size
)
729 * Really subtle: The last entry with cs->cs_size==ULONG_MAX
730 * has cs_{dma,}cachep==NULL. Thus no special case
731 * for large kmalloc calls required.
733 if (unlikely(gfpflags
& GFP_DMA
))
734 return csizep
->cs_dmacachep
;
735 return csizep
->cs_cachep
;
738 struct kmem_cache
*kmem_find_general_cachep(size_t size
, gfp_t gfpflags
)
740 return __find_general_cachep(size
, gfpflags
);
742 EXPORT_SYMBOL(kmem_find_general_cachep
);
744 static size_t slab_mgmt_size(size_t nr_objs
, size_t align
)
746 return ALIGN(sizeof(struct slab
)+nr_objs
*sizeof(kmem_bufctl_t
), align
);
750 * Calculate the number of objects and left-over bytes for a given buffer size.
752 static void cache_estimate(unsigned long gfporder
, size_t buffer_size
,
753 size_t align
, int flags
, size_t *left_over
,
758 size_t slab_size
= PAGE_SIZE
<< gfporder
;
761 * The slab management structure can be either off the slab or
762 * on it. For the latter case, the memory allocated for a
766 * - One kmem_bufctl_t for each object
767 * - Padding to respect alignment of @align
768 * - @buffer_size bytes for each object
770 * If the slab management structure is off the slab, then the
771 * alignment will already be calculated into the size. Because
772 * the slabs are all pages aligned, the objects will be at the
773 * correct alignment when allocated.
775 if (flags
& CFLGS_OFF_SLAB
) {
777 nr_objs
= slab_size
/ buffer_size
;
779 if (nr_objs
> SLAB_LIMIT
)
780 nr_objs
= SLAB_LIMIT
;
783 * Ignore padding for the initial guess. The padding
784 * is at most @align-1 bytes, and @buffer_size is at
785 * least @align. In the worst case, this result will
786 * be one greater than the number of objects that fit
787 * into the memory allocation when taking the padding
790 nr_objs
= (slab_size
- sizeof(struct slab
)) /
791 (buffer_size
+ sizeof(kmem_bufctl_t
));
794 * This calculated number will be either the right
795 * amount, or one greater than what we want.
797 if (slab_mgmt_size(nr_objs
, align
) + nr_objs
*buffer_size
801 if (nr_objs
> SLAB_LIMIT
)
802 nr_objs
= SLAB_LIMIT
;
804 mgmt_size
= slab_mgmt_size(nr_objs
, align
);
807 *left_over
= slab_size
- nr_objs
*buffer_size
- mgmt_size
;
810 #define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg)
812 static void __slab_error(const char *function
, struct kmem_cache
*cachep
,
815 printk(KERN_ERR
"slab error in %s(): cache `%s': %s\n",
816 function
, cachep
->name
, msg
);
822 * Special reaping functions for NUMA systems called from cache_reap().
823 * These take care of doing round robin flushing of alien caches (containing
824 * objects freed on different nodes from which they were allocated) and the
825 * flushing of remote pcps by calling drain_node_pages.
827 static DEFINE_PER_CPU(unsigned long, reap_node
);
829 static void init_reap_node(int cpu
)
833 node
= next_node(cpu_to_node(cpu
), node_online_map
);
834 if (node
== MAX_NUMNODES
)
835 node
= first_node(node_online_map
);
837 __get_cpu_var(reap_node
) = node
;
840 static void next_reap_node(void)
842 int node
= __get_cpu_var(reap_node
);
845 * Also drain per cpu pages on remote zones
847 if (node
!= numa_node_id())
848 drain_node_pages(node
);
850 node
= next_node(node
, node_online_map
);
851 if (unlikely(node
>= MAX_NUMNODES
))
852 node
= first_node(node_online_map
);
853 __get_cpu_var(reap_node
) = node
;
857 #define init_reap_node(cpu) do { } while (0)
858 #define next_reap_node(void) do { } while (0)
862 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
863 * via the workqueue/eventd.
864 * Add the CPU number into the expiration time to minimize the possibility of
865 * the CPUs getting into lockstep and contending for the global cache chain
868 static void __devinit
start_cpu_timer(int cpu
)
870 struct work_struct
*reap_work
= &per_cpu(reap_work
, cpu
);
873 * When this gets called from do_initcalls via cpucache_init(),
874 * init_workqueues() has already run, so keventd will be setup
877 if (keventd_up() && reap_work
->func
== NULL
) {
879 INIT_WORK(reap_work
, cache_reap
, NULL
);
880 schedule_delayed_work_on(cpu
, reap_work
, HZ
+ 3 * cpu
);
884 static struct array_cache
*alloc_arraycache(int node
, int entries
,
887 int memsize
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
888 struct array_cache
*nc
= NULL
;
890 nc
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
894 nc
->batchcount
= batchcount
;
896 spin_lock_init(&nc
->lock
);
902 * Transfer objects in one arraycache to another.
903 * Locking must be handled by the caller.
905 * Return the number of entries transferred.
907 static int transfer_objects(struct array_cache
*to
,
908 struct array_cache
*from
, unsigned int max
)
910 /* Figure out how many entries to transfer */
911 int nr
= min(min(from
->avail
, max
), to
->limit
- to
->avail
);
916 memcpy(to
->entry
+ to
->avail
, from
->entry
+ from
->avail
-nr
,
926 static void *__cache_alloc_node(struct kmem_cache
*, gfp_t
, int);
927 static void *alternate_node_alloc(struct kmem_cache
*, gfp_t
);
929 static struct array_cache
**alloc_alien_cache(int node
, int limit
)
931 struct array_cache
**ac_ptr
;
932 int memsize
= sizeof(void *) * MAX_NUMNODES
;
937 ac_ptr
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
940 if (i
== node
|| !node_online(i
)) {
944 ac_ptr
[i
] = alloc_arraycache(node
, limit
, 0xbaadf00d);
946 for (i
--; i
<= 0; i
--)
956 static void free_alien_cache(struct array_cache
**ac_ptr
)
967 static void __drain_alien_cache(struct kmem_cache
*cachep
,
968 struct array_cache
*ac
, int node
)
970 struct kmem_list3
*rl3
= cachep
->nodelists
[node
];
973 spin_lock(&rl3
->list_lock
);
975 * Stuff objects into the remote nodes shared array first.
976 * That way we could avoid the overhead of putting the objects
977 * into the free lists and getting them back later.
980 transfer_objects(rl3
->shared
, ac
, ac
->limit
);
982 free_block(cachep
, ac
->entry
, ac
->avail
, node
);
984 spin_unlock(&rl3
->list_lock
);
989 * Called from cache_reap() to regularly drain alien caches round robin.
991 static void reap_alien(struct kmem_cache
*cachep
, struct kmem_list3
*l3
)
993 int node
= __get_cpu_var(reap_node
);
996 struct array_cache
*ac
= l3
->alien
[node
];
998 if (ac
&& ac
->avail
&& spin_trylock_irq(&ac
->lock
)) {
999 __drain_alien_cache(cachep
, ac
, node
);
1000 spin_unlock_irq(&ac
->lock
);
1005 static void drain_alien_cache(struct kmem_cache
*cachep
,
1006 struct array_cache
**alien
)
1009 struct array_cache
*ac
;
1010 unsigned long flags
;
1012 for_each_online_node(i
) {
1015 spin_lock_irqsave(&ac
->lock
, flags
);
1016 __drain_alien_cache(cachep
, ac
, i
);
1017 spin_unlock_irqrestore(&ac
->lock
, flags
);
1022 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
1024 struct slab
*slabp
= virt_to_slab(objp
);
1025 int nodeid
= slabp
->nodeid
;
1026 struct kmem_list3
*l3
;
1027 struct array_cache
*alien
= NULL
;
1030 * Make sure we are not freeing a object from another node to the array
1031 * cache on this cpu.
1033 if (likely(slabp
->nodeid
== numa_node_id()))
1036 l3
= cachep
->nodelists
[numa_node_id()];
1037 STATS_INC_NODEFREES(cachep
);
1038 if (l3
->alien
&& l3
->alien
[nodeid
]) {
1039 alien
= l3
->alien
[nodeid
];
1040 spin_lock(&alien
->lock
);
1041 if (unlikely(alien
->avail
== alien
->limit
)) {
1042 STATS_INC_ACOVERFLOW(cachep
);
1043 __drain_alien_cache(cachep
, alien
, nodeid
);
1045 alien
->entry
[alien
->avail
++] = objp
;
1046 spin_unlock(&alien
->lock
);
1048 spin_lock(&(cachep
->nodelists
[nodeid
])->list_lock
);
1049 free_block(cachep
, &objp
, 1, nodeid
);
1050 spin_unlock(&(cachep
->nodelists
[nodeid
])->list_lock
);
1057 #define drain_alien_cache(cachep, alien) do { } while (0)
1058 #define reap_alien(cachep, l3) do { } while (0)
1060 static inline struct array_cache
**alloc_alien_cache(int node
, int limit
)
1062 return (struct array_cache
**) 0x01020304ul
;
1065 static inline void free_alien_cache(struct array_cache
**ac_ptr
)
1069 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
1076 static int __devinit
cpuup_callback(struct notifier_block
*nfb
,
1077 unsigned long action
, void *hcpu
)
1079 long cpu
= (long)hcpu
;
1080 struct kmem_cache
*cachep
;
1081 struct kmem_list3
*l3
= NULL
;
1082 int node
= cpu_to_node(cpu
);
1083 int memsize
= sizeof(struct kmem_list3
);
1086 case CPU_UP_PREPARE
:
1087 mutex_lock(&cache_chain_mutex
);
1089 * We need to do this right in the beginning since
1090 * alloc_arraycache's are going to use this list.
1091 * kmalloc_node allows us to add the slab to the right
1092 * kmem_list3 and not this cpu's kmem_list3
1095 list_for_each_entry(cachep
, &cache_chain
, next
) {
1097 * Set up the size64 kmemlist for cpu before we can
1098 * begin anything. Make sure some other cpu on this
1099 * node has not already allocated this
1101 if (!cachep
->nodelists
[node
]) {
1102 l3
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
1105 kmem_list3_init(l3
);
1106 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
+
1107 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1110 * The l3s don't come and go as CPUs come and
1111 * go. cache_chain_mutex is sufficient
1114 cachep
->nodelists
[node
] = l3
;
1117 spin_lock_irq(&cachep
->nodelists
[node
]->list_lock
);
1118 cachep
->nodelists
[node
]->free_limit
=
1119 (1 + nr_cpus_node(node
)) *
1120 cachep
->batchcount
+ cachep
->num
;
1121 spin_unlock_irq(&cachep
->nodelists
[node
]->list_lock
);
1125 * Now we can go ahead with allocating the shared arrays and
1128 list_for_each_entry(cachep
, &cache_chain
, next
) {
1129 struct array_cache
*nc
;
1130 struct array_cache
*shared
;
1131 struct array_cache
**alien
;
1133 nc
= alloc_arraycache(node
, cachep
->limit
,
1134 cachep
->batchcount
);
1137 shared
= alloc_arraycache(node
,
1138 cachep
->shared
* cachep
->batchcount
,
1143 alien
= alloc_alien_cache(node
, cachep
->limit
);
1146 cachep
->array
[cpu
] = nc
;
1147 l3
= cachep
->nodelists
[node
];
1150 spin_lock_irq(&l3
->list_lock
);
1153 * We are serialised from CPU_DEAD or
1154 * CPU_UP_CANCELLED by the cpucontrol lock
1156 l3
->shared
= shared
;
1165 spin_unlock_irq(&l3
->list_lock
);
1167 free_alien_cache(alien
);
1169 mutex_unlock(&cache_chain_mutex
);
1172 start_cpu_timer(cpu
);
1174 #ifdef CONFIG_HOTPLUG_CPU
1177 * Even if all the cpus of a node are down, we don't free the
1178 * kmem_list3 of any cache. This to avoid a race between
1179 * cpu_down, and a kmalloc allocation from another cpu for
1180 * memory from the node of the cpu going down. The list3
1181 * structure is usually allocated from kmem_cache_create() and
1182 * gets destroyed at kmem_cache_destroy().
1185 case CPU_UP_CANCELED
:
1186 mutex_lock(&cache_chain_mutex
);
1187 list_for_each_entry(cachep
, &cache_chain
, next
) {
1188 struct array_cache
*nc
;
1189 struct array_cache
*shared
;
1190 struct array_cache
**alien
;
1193 mask
= node_to_cpumask(node
);
1194 /* cpu is dead; no one can alloc from it. */
1195 nc
= cachep
->array
[cpu
];
1196 cachep
->array
[cpu
] = NULL
;
1197 l3
= cachep
->nodelists
[node
];
1200 goto free_array_cache
;
1202 spin_lock_irq(&l3
->list_lock
);
1204 /* Free limit for this kmem_list3 */
1205 l3
->free_limit
-= cachep
->batchcount
;
1207 free_block(cachep
, nc
->entry
, nc
->avail
, node
);
1209 if (!cpus_empty(mask
)) {
1210 spin_unlock_irq(&l3
->list_lock
);
1211 goto free_array_cache
;
1214 shared
= l3
->shared
;
1216 free_block(cachep
, l3
->shared
->entry
,
1217 l3
->shared
->avail
, node
);
1224 spin_unlock_irq(&l3
->list_lock
);
1228 drain_alien_cache(cachep
, alien
);
1229 free_alien_cache(alien
);
1235 * In the previous loop, all the objects were freed to
1236 * the respective cache's slabs, now we can go ahead and
1237 * shrink each nodelist to its limit.
1239 list_for_each_entry(cachep
, &cache_chain
, next
) {
1240 l3
= cachep
->nodelists
[node
];
1243 spin_lock_irq(&l3
->list_lock
);
1244 /* free slabs belonging to this node */
1245 __node_shrink(cachep
, node
);
1246 spin_unlock_irq(&l3
->list_lock
);
1248 mutex_unlock(&cache_chain_mutex
);
1254 mutex_unlock(&cache_chain_mutex
);
1258 static struct notifier_block __cpuinitdata cpucache_notifier
= {
1259 &cpuup_callback
, NULL
, 0
1263 * swap the static kmem_list3 with kmalloced memory
1265 static void init_list(struct kmem_cache
*cachep
, struct kmem_list3
*list
,
1268 struct kmem_list3
*ptr
;
1270 BUG_ON(cachep
->nodelists
[nodeid
] != list
);
1271 ptr
= kmalloc_node(sizeof(struct kmem_list3
), GFP_KERNEL
, nodeid
);
1274 local_irq_disable();
1275 memcpy(ptr
, list
, sizeof(struct kmem_list3
));
1276 MAKE_ALL_LISTS(cachep
, ptr
, nodeid
);
1277 cachep
->nodelists
[nodeid
] = ptr
;
1282 * Initialisation. Called after the page allocator have been initialised and
1283 * before smp_init().
1285 void __init
kmem_cache_init(void)
1288 struct cache_sizes
*sizes
;
1289 struct cache_names
*names
;
1293 for (i
= 0; i
< NUM_INIT_LISTS
; i
++) {
1294 kmem_list3_init(&initkmem_list3
[i
]);
1295 if (i
< MAX_NUMNODES
)
1296 cache_cache
.nodelists
[i
] = NULL
;
1300 * Fragmentation resistance on low memory - only use bigger
1301 * page orders on machines with more than 32MB of memory.
1303 if (num_physpages
> (32 << 20) >> PAGE_SHIFT
)
1304 slab_break_gfp_order
= BREAK_GFP_ORDER_HI
;
1306 /* Bootstrap is tricky, because several objects are allocated
1307 * from caches that do not exist yet:
1308 * 1) initialize the cache_cache cache: it contains the struct
1309 * kmem_cache structures of all caches, except cache_cache itself:
1310 * cache_cache is statically allocated.
1311 * Initially an __init data area is used for the head array and the
1312 * kmem_list3 structures, it's replaced with a kmalloc allocated
1313 * array at the end of the bootstrap.
1314 * 2) Create the first kmalloc cache.
1315 * The struct kmem_cache for the new cache is allocated normally.
1316 * An __init data area is used for the head array.
1317 * 3) Create the remaining kmalloc caches, with minimally sized
1319 * 4) Replace the __init data head arrays for cache_cache and the first
1320 * kmalloc cache with kmalloc allocated arrays.
1321 * 5) Replace the __init data for kmem_list3 for cache_cache and
1322 * the other cache's with kmalloc allocated memory.
1323 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1326 /* 1) create the cache_cache */
1327 INIT_LIST_HEAD(&cache_chain
);
1328 list_add(&cache_cache
.next
, &cache_chain
);
1329 cache_cache
.colour_off
= cache_line_size();
1330 cache_cache
.array
[smp_processor_id()] = &initarray_cache
.cache
;
1331 cache_cache
.nodelists
[numa_node_id()] = &initkmem_list3
[CACHE_CACHE
];
1333 cache_cache
.buffer_size
= ALIGN(cache_cache
.buffer_size
,
1336 for (order
= 0; order
< MAX_ORDER
; order
++) {
1337 cache_estimate(order
, cache_cache
.buffer_size
,
1338 cache_line_size(), 0, &left_over
, &cache_cache
.num
);
1339 if (cache_cache
.num
)
1342 BUG_ON(!cache_cache
.num
);
1343 cache_cache
.gfporder
= order
;
1344 cache_cache
.colour
= left_over
/ cache_cache
.colour_off
;
1345 cache_cache
.slab_size
= ALIGN(cache_cache
.num
* sizeof(kmem_bufctl_t
) +
1346 sizeof(struct slab
), cache_line_size());
1348 /* 2+3) create the kmalloc caches */
1349 sizes
= malloc_sizes
;
1350 names
= cache_names
;
1353 * Initialize the caches that provide memory for the array cache and the
1354 * kmem_list3 structures first. Without this, further allocations will
1358 sizes
[INDEX_AC
].cs_cachep
= kmem_cache_create(names
[INDEX_AC
].name
,
1359 sizes
[INDEX_AC
].cs_size
,
1360 ARCH_KMALLOC_MINALIGN
,
1361 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1364 if (INDEX_AC
!= INDEX_L3
) {
1365 sizes
[INDEX_L3
].cs_cachep
=
1366 kmem_cache_create(names
[INDEX_L3
].name
,
1367 sizes
[INDEX_L3
].cs_size
,
1368 ARCH_KMALLOC_MINALIGN
,
1369 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1373 slab_early_init
= 0;
1375 while (sizes
->cs_size
!= ULONG_MAX
) {
1377 * For performance, all the general caches are L1 aligned.
1378 * This should be particularly beneficial on SMP boxes, as it
1379 * eliminates "false sharing".
1380 * Note for systems short on memory removing the alignment will
1381 * allow tighter packing of the smaller caches.
1383 if (!sizes
->cs_cachep
) {
1384 sizes
->cs_cachep
= kmem_cache_create(names
->name
,
1386 ARCH_KMALLOC_MINALIGN
,
1387 ARCH_KMALLOC_FLAGS
|SLAB_PANIC
,
1391 sizes
->cs_dmacachep
= kmem_cache_create(names
->name_dma
,
1393 ARCH_KMALLOC_MINALIGN
,
1394 ARCH_KMALLOC_FLAGS
|SLAB_CACHE_DMA
|
1400 /* 4) Replace the bootstrap head arrays */
1404 ptr
= kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1406 local_irq_disable();
1407 BUG_ON(cpu_cache_get(&cache_cache
) != &initarray_cache
.cache
);
1408 memcpy(ptr
, cpu_cache_get(&cache_cache
),
1409 sizeof(struct arraycache_init
));
1410 cache_cache
.array
[smp_processor_id()] = ptr
;
1413 ptr
= kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1415 local_irq_disable();
1416 BUG_ON(cpu_cache_get(malloc_sizes
[INDEX_AC
].cs_cachep
)
1417 != &initarray_generic
.cache
);
1418 memcpy(ptr
, cpu_cache_get(malloc_sizes
[INDEX_AC
].cs_cachep
),
1419 sizeof(struct arraycache_init
));
1420 malloc_sizes
[INDEX_AC
].cs_cachep
->array
[smp_processor_id()] =
1424 /* 5) Replace the bootstrap kmem_list3's */
1427 /* Replace the static kmem_list3 structures for the boot cpu */
1428 init_list(&cache_cache
, &initkmem_list3
[CACHE_CACHE
],
1431 for_each_online_node(node
) {
1432 init_list(malloc_sizes
[INDEX_AC
].cs_cachep
,
1433 &initkmem_list3
[SIZE_AC
+ node
], node
);
1435 if (INDEX_AC
!= INDEX_L3
) {
1436 init_list(malloc_sizes
[INDEX_L3
].cs_cachep
,
1437 &initkmem_list3
[SIZE_L3
+ node
],
1443 /* 6) resize the head arrays to their final sizes */
1445 struct kmem_cache
*cachep
;
1446 mutex_lock(&cache_chain_mutex
);
1447 list_for_each_entry(cachep
, &cache_chain
, next
)
1448 enable_cpucache(cachep
);
1449 mutex_unlock(&cache_chain_mutex
);
1453 g_cpucache_up
= FULL
;
1456 * Register a cpu startup notifier callback that initializes
1457 * cpu_cache_get for all new cpus
1459 register_cpu_notifier(&cpucache_notifier
);
1462 * The reap timers are started later, with a module init call: That part
1463 * of the kernel is not yet operational.
1467 static int __init
cpucache_init(void)
1472 * Register the timers that return unneeded pages to the page allocator
1474 for_each_online_cpu(cpu
)
1475 start_cpu_timer(cpu
);
1478 __initcall(cpucache_init
);
1481 * Interface to system's page allocator. No need to hold the cache-lock.
1483 * If we requested dmaable memory, we will get it. Even if we
1484 * did not request dmaable memory, we might get it, but that
1485 * would be relatively rare and ignorable.
1487 static void *kmem_getpages(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
1495 * Nommu uses slab's for process anonymous memory allocations, and thus
1496 * requires __GFP_COMP to properly refcount higher order allocations
1498 flags
|= __GFP_COMP
;
1500 flags
|= cachep
->gfpflags
;
1502 page
= alloc_pages_node(nodeid
, flags
, cachep
->gfporder
);
1506 nr_pages
= (1 << cachep
->gfporder
);
1507 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1508 atomic_add(nr_pages
, &slab_reclaim_pages
);
1509 add_page_state(nr_slab
, nr_pages
);
1510 for (i
= 0; i
< nr_pages
; i
++)
1511 __SetPageSlab(page
+ i
);
1512 return page_address(page
);
1516 * Interface to system's page release.
1518 static void kmem_freepages(struct kmem_cache
*cachep
, void *addr
)
1520 unsigned long i
= (1 << cachep
->gfporder
);
1521 struct page
*page
= virt_to_page(addr
);
1522 const unsigned long nr_freed
= i
;
1525 BUG_ON(!PageSlab(page
));
1526 __ClearPageSlab(page
);
1529 sub_page_state(nr_slab
, nr_freed
);
1530 if (current
->reclaim_state
)
1531 current
->reclaim_state
->reclaimed_slab
+= nr_freed
;
1532 free_pages((unsigned long)addr
, cachep
->gfporder
);
1533 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1534 atomic_sub(1 << cachep
->gfporder
, &slab_reclaim_pages
);
1537 static void kmem_rcu_free(struct rcu_head
*head
)
1539 struct slab_rcu
*slab_rcu
= (struct slab_rcu
*)head
;
1540 struct kmem_cache
*cachep
= slab_rcu
->cachep
;
1542 kmem_freepages(cachep
, slab_rcu
->addr
);
1543 if (OFF_SLAB(cachep
))
1544 kmem_cache_free(cachep
->slabp_cache
, slab_rcu
);
1549 #ifdef CONFIG_DEBUG_PAGEALLOC
1550 static void store_stackinfo(struct kmem_cache
*cachep
, unsigned long *addr
,
1551 unsigned long caller
)
1553 int size
= obj_size(cachep
);
1555 addr
= (unsigned long *)&((char *)addr
)[obj_offset(cachep
)];
1557 if (size
< 5 * sizeof(unsigned long))
1560 *addr
++ = 0x12345678;
1562 *addr
++ = smp_processor_id();
1563 size
-= 3 * sizeof(unsigned long);
1565 unsigned long *sptr
= &caller
;
1566 unsigned long svalue
;
1568 while (!kstack_end(sptr
)) {
1570 if (kernel_text_address(svalue
)) {
1572 size
-= sizeof(unsigned long);
1573 if (size
<= sizeof(unsigned long))
1579 *addr
++ = 0x87654321;
1583 static void poison_obj(struct kmem_cache
*cachep
, void *addr
, unsigned char val
)
1585 int size
= obj_size(cachep
);
1586 addr
= &((char *)addr
)[obj_offset(cachep
)];
1588 memset(addr
, val
, size
);
1589 *(unsigned char *)(addr
+ size
- 1) = POISON_END
;
1592 static void dump_line(char *data
, int offset
, int limit
)
1595 printk(KERN_ERR
"%03x:", offset
);
1596 for (i
= 0; i
< limit
; i
++)
1597 printk(" %02x", (unsigned char)data
[offset
+ i
]);
1604 static void print_objinfo(struct kmem_cache
*cachep
, void *objp
, int lines
)
1609 if (cachep
->flags
& SLAB_RED_ZONE
) {
1610 printk(KERN_ERR
"Redzone: 0x%lx/0x%lx.\n",
1611 *dbg_redzone1(cachep
, objp
),
1612 *dbg_redzone2(cachep
, objp
));
1615 if (cachep
->flags
& SLAB_STORE_USER
) {
1616 printk(KERN_ERR
"Last user: [<%p>]",
1617 *dbg_userword(cachep
, objp
));
1618 print_symbol("(%s)",
1619 (unsigned long)*dbg_userword(cachep
, objp
));
1622 realobj
= (char *)objp
+ obj_offset(cachep
);
1623 size
= obj_size(cachep
);
1624 for (i
= 0; i
< size
&& lines
; i
+= 16, lines
--) {
1627 if (i
+ limit
> size
)
1629 dump_line(realobj
, i
, limit
);
1633 static void check_poison_obj(struct kmem_cache
*cachep
, void *objp
)
1639 realobj
= (char *)objp
+ obj_offset(cachep
);
1640 size
= obj_size(cachep
);
1642 for (i
= 0; i
< size
; i
++) {
1643 char exp
= POISON_FREE
;
1646 if (realobj
[i
] != exp
) {
1652 "Slab corruption: start=%p, len=%d\n",
1654 print_objinfo(cachep
, objp
, 0);
1656 /* Hexdump the affected line */
1659 if (i
+ limit
> size
)
1661 dump_line(realobj
, i
, limit
);
1664 /* Limit to 5 lines */
1670 /* Print some data about the neighboring objects, if they
1673 struct slab
*slabp
= virt_to_slab(objp
);
1676 objnr
= obj_to_index(cachep
, slabp
, objp
);
1678 objp
= index_to_obj(cachep
, slabp
, objnr
- 1);
1679 realobj
= (char *)objp
+ obj_offset(cachep
);
1680 printk(KERN_ERR
"Prev obj: start=%p, len=%d\n",
1682 print_objinfo(cachep
, objp
, 2);
1684 if (objnr
+ 1 < cachep
->num
) {
1685 objp
= index_to_obj(cachep
, slabp
, objnr
+ 1);
1686 realobj
= (char *)objp
+ obj_offset(cachep
);
1687 printk(KERN_ERR
"Next obj: start=%p, len=%d\n",
1689 print_objinfo(cachep
, objp
, 2);
1697 * slab_destroy_objs - destroy a slab and its objects
1698 * @cachep: cache pointer being destroyed
1699 * @slabp: slab pointer being destroyed
1701 * Call the registered destructor for each object in a slab that is being
1704 static void slab_destroy_objs(struct kmem_cache
*cachep
, struct slab
*slabp
)
1707 for (i
= 0; i
< cachep
->num
; i
++) {
1708 void *objp
= index_to_obj(cachep
, slabp
, i
);
1710 if (cachep
->flags
& SLAB_POISON
) {
1711 #ifdef CONFIG_DEBUG_PAGEALLOC
1712 if (cachep
->buffer_size
% PAGE_SIZE
== 0 &&
1714 kernel_map_pages(virt_to_page(objp
),
1715 cachep
->buffer_size
/ PAGE_SIZE
, 1);
1717 check_poison_obj(cachep
, objp
);
1719 check_poison_obj(cachep
, objp
);
1722 if (cachep
->flags
& SLAB_RED_ZONE
) {
1723 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
1724 slab_error(cachep
, "start of a freed object "
1726 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
1727 slab_error(cachep
, "end of a freed object "
1730 if (cachep
->dtor
&& !(cachep
->flags
& SLAB_POISON
))
1731 (cachep
->dtor
) (objp
+ obj_offset(cachep
), cachep
, 0);
1735 static void slab_destroy_objs(struct kmem_cache
*cachep
, struct slab
*slabp
)
1739 for (i
= 0; i
< cachep
->num
; i
++) {
1740 void *objp
= index_to_obj(cachep
, slabp
, i
);
1741 (cachep
->dtor
) (objp
, cachep
, 0);
1748 * slab_destroy - destroy and release all objects in a slab
1749 * @cachep: cache pointer being destroyed
1750 * @slabp: slab pointer being destroyed
1752 * Destroy all the objs in a slab, and release the mem back to the system.
1753 * Before calling the slab must have been unlinked from the cache. The
1754 * cache-lock is not held/needed.
1756 static void slab_destroy(struct kmem_cache
*cachep
, struct slab
*slabp
)
1758 void *addr
= slabp
->s_mem
- slabp
->colouroff
;
1760 slab_destroy_objs(cachep
, slabp
);
1761 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
)) {
1762 struct slab_rcu
*slab_rcu
;
1764 slab_rcu
= (struct slab_rcu
*)slabp
;
1765 slab_rcu
->cachep
= cachep
;
1766 slab_rcu
->addr
= addr
;
1767 call_rcu(&slab_rcu
->head
, kmem_rcu_free
);
1769 kmem_freepages(cachep
, addr
);
1770 if (OFF_SLAB(cachep
))
1771 kmem_cache_free(cachep
->slabp_cache
, slabp
);
1776 * For setting up all the kmem_list3s for cache whose buffer_size is same as
1777 * size of kmem_list3.
1779 static void set_up_list3s(struct kmem_cache
*cachep
, int index
)
1783 for_each_online_node(node
) {
1784 cachep
->nodelists
[node
] = &initkmem_list3
[index
+ node
];
1785 cachep
->nodelists
[node
]->next_reap
= jiffies
+
1787 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1792 * calculate_slab_order - calculate size (page order) of slabs
1793 * @cachep: pointer to the cache that is being created
1794 * @size: size of objects to be created in this cache.
1795 * @align: required alignment for the objects.
1796 * @flags: slab allocation flags
1798 * Also calculates the number of objects per slab.
1800 * This could be made much more intelligent. For now, try to avoid using
1801 * high order pages for slabs. When the gfp() functions are more friendly
1802 * towards high-order requests, this should be changed.
1804 static size_t calculate_slab_order(struct kmem_cache
*cachep
,
1805 size_t size
, size_t align
, unsigned long flags
)
1807 unsigned long offslab_limit
;
1808 size_t left_over
= 0;
1811 for (gfporder
= 0; gfporder
<= MAX_GFP_ORDER
; gfporder
++) {
1815 cache_estimate(gfporder
, size
, align
, flags
, &remainder
, &num
);
1819 if (flags
& CFLGS_OFF_SLAB
) {
1821 * Max number of objs-per-slab for caches which
1822 * use off-slab slabs. Needed to avoid a possible
1823 * looping condition in cache_grow().
1825 offslab_limit
= size
- sizeof(struct slab
);
1826 offslab_limit
/= sizeof(kmem_bufctl_t
);
1828 if (num
> offslab_limit
)
1832 /* Found something acceptable - save it away */
1834 cachep
->gfporder
= gfporder
;
1835 left_over
= remainder
;
1838 * A VFS-reclaimable slab tends to have most allocations
1839 * as GFP_NOFS and we really don't want to have to be allocating
1840 * higher-order pages when we are unable to shrink dcache.
1842 if (flags
& SLAB_RECLAIM_ACCOUNT
)
1846 * Large number of objects is good, but very large slabs are
1847 * currently bad for the gfp()s.
1849 if (gfporder
>= slab_break_gfp_order
)
1853 * Acceptable internal fragmentation?
1855 if (left_over
* 8 <= (PAGE_SIZE
<< gfporder
))
1861 static void setup_cpu_cache(struct kmem_cache
*cachep
)
1863 if (g_cpucache_up
== FULL
) {
1864 enable_cpucache(cachep
);
1867 if (g_cpucache_up
== NONE
) {
1869 * Note: the first kmem_cache_create must create the cache
1870 * that's used by kmalloc(24), otherwise the creation of
1871 * further caches will BUG().
1873 cachep
->array
[smp_processor_id()] = &initarray_generic
.cache
;
1876 * If the cache that's used by kmalloc(sizeof(kmem_list3)) is
1877 * the first cache, then we need to set up all its list3s,
1878 * otherwise the creation of further caches will BUG().
1880 set_up_list3s(cachep
, SIZE_AC
);
1881 if (INDEX_AC
== INDEX_L3
)
1882 g_cpucache_up
= PARTIAL_L3
;
1884 g_cpucache_up
= PARTIAL_AC
;
1886 cachep
->array
[smp_processor_id()] =
1887 kmalloc(sizeof(struct arraycache_init
), GFP_KERNEL
);
1889 if (g_cpucache_up
== PARTIAL_AC
) {
1890 set_up_list3s(cachep
, SIZE_L3
);
1891 g_cpucache_up
= PARTIAL_L3
;
1894 for_each_online_node(node
) {
1895 cachep
->nodelists
[node
] =
1896 kmalloc_node(sizeof(struct kmem_list3
),
1898 BUG_ON(!cachep
->nodelists
[node
]);
1899 kmem_list3_init(cachep
->nodelists
[node
]);
1903 cachep
->nodelists
[numa_node_id()]->next_reap
=
1904 jiffies
+ REAPTIMEOUT_LIST3
+
1905 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
1907 cpu_cache_get(cachep
)->avail
= 0;
1908 cpu_cache_get(cachep
)->limit
= BOOT_CPUCACHE_ENTRIES
;
1909 cpu_cache_get(cachep
)->batchcount
= 1;
1910 cpu_cache_get(cachep
)->touched
= 0;
1911 cachep
->batchcount
= 1;
1912 cachep
->limit
= BOOT_CPUCACHE_ENTRIES
;
1916 * kmem_cache_create - Create a cache.
1917 * @name: A string which is used in /proc/slabinfo to identify this cache.
1918 * @size: The size of objects to be created in this cache.
1919 * @align: The required alignment for the objects.
1920 * @flags: SLAB flags
1921 * @ctor: A constructor for the objects.
1922 * @dtor: A destructor for the objects.
1924 * Returns a ptr to the cache on success, NULL on failure.
1925 * Cannot be called within a int, but can be interrupted.
1926 * The @ctor is run when new pages are allocated by the cache
1927 * and the @dtor is run before the pages are handed back.
1929 * @name must be valid until the cache is destroyed. This implies that
1930 * the module calling this has to destroy the cache before getting unloaded.
1934 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
1935 * to catch references to uninitialised memory.
1937 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
1938 * for buffer overruns.
1940 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
1941 * cacheline. This can be beneficial if you're counting cycles as closely
1945 kmem_cache_create (const char *name
, size_t size
, size_t align
,
1946 unsigned long flags
,
1947 void (*ctor
)(void*, struct kmem_cache
*, unsigned long),
1948 void (*dtor
)(void*, struct kmem_cache
*, unsigned long))
1950 size_t left_over
, slab_size
, ralign
;
1951 struct kmem_cache
*cachep
= NULL
, *pc
;
1954 * Sanity checks... these are all serious usage bugs.
1956 if (!name
|| in_interrupt() || (size
< BYTES_PER_WORD
) ||
1957 (size
> (1 << MAX_OBJ_ORDER
) * PAGE_SIZE
) || (dtor
&& !ctor
)) {
1958 printk(KERN_ERR
"%s: Early error in slab %s\n", __FUNCTION__
,
1964 * Prevent CPUs from coming and going.
1965 * lock_cpu_hotplug() nests outside cache_chain_mutex
1969 mutex_lock(&cache_chain_mutex
);
1971 list_for_each_entry(pc
, &cache_chain
, next
) {
1972 mm_segment_t old_fs
= get_fs();
1977 * This happens when the module gets unloaded and doesn't
1978 * destroy its slab cache and no-one else reuses the vmalloc
1979 * area of the module. Print a warning.
1982 res
= __get_user(tmp
, pc
->name
);
1985 printk("SLAB: cache with size %d has lost its name\n",
1990 if (!strcmp(pc
->name
, name
)) {
1991 printk("kmem_cache_create: duplicate cache %s\n", name
);
1998 WARN_ON(strchr(name
, ' ')); /* It confuses parsers */
1999 if ((flags
& SLAB_DEBUG_INITIAL
) && !ctor
) {
2000 /* No constructor, but inital state check requested */
2001 printk(KERN_ERR
"%s: No con, but init state check "
2002 "requested - %s\n", __FUNCTION__
, name
);
2003 flags
&= ~SLAB_DEBUG_INITIAL
;
2007 * Enable redzoning and last user accounting, except for caches with
2008 * large objects, if the increased size would increase the object size
2009 * above the next power of two: caches with object sizes just above a
2010 * power of two have a significant amount of internal fragmentation.
2012 if (size
< 4096 || fls(size
- 1) == fls(size
-1 + 3 * BYTES_PER_WORD
))
2013 flags
|= SLAB_RED_ZONE
| SLAB_STORE_USER
;
2014 if (!(flags
& SLAB_DESTROY_BY_RCU
))
2015 flags
|= SLAB_POISON
;
2017 if (flags
& SLAB_DESTROY_BY_RCU
)
2018 BUG_ON(flags
& SLAB_POISON
);
2020 if (flags
& SLAB_DESTROY_BY_RCU
)
2024 * Always checks flags, a caller might be expecting debug support which
2027 BUG_ON(flags
& ~CREATE_MASK
);
2030 * Check that size is in terms of words. This is needed to avoid
2031 * unaligned accesses for some archs when redzoning is used, and makes
2032 * sure any on-slab bufctl's are also correctly aligned.
2034 if (size
& (BYTES_PER_WORD
- 1)) {
2035 size
+= (BYTES_PER_WORD
- 1);
2036 size
&= ~(BYTES_PER_WORD
- 1);
2039 /* calculate the final buffer alignment: */
2041 /* 1) arch recommendation: can be overridden for debug */
2042 if (flags
& SLAB_HWCACHE_ALIGN
) {
2044 * Default alignment: as specified by the arch code. Except if
2045 * an object is really small, then squeeze multiple objects into
2048 ralign
= cache_line_size();
2049 while (size
<= ralign
/ 2)
2052 ralign
= BYTES_PER_WORD
;
2054 /* 2) arch mandated alignment: disables debug if necessary */
2055 if (ralign
< ARCH_SLAB_MINALIGN
) {
2056 ralign
= ARCH_SLAB_MINALIGN
;
2057 if (ralign
> BYTES_PER_WORD
)
2058 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2060 /* 3) caller mandated alignment: disables debug if necessary */
2061 if (ralign
< align
) {
2063 if (ralign
> BYTES_PER_WORD
)
2064 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2067 * 4) Store it. Note that the debug code below can reduce
2068 * the alignment to BYTES_PER_WORD.
2072 /* Get cache's description obj. */
2073 cachep
= kmem_cache_zalloc(&cache_cache
, SLAB_KERNEL
);
2078 cachep
->obj_size
= size
;
2080 if (flags
& SLAB_RED_ZONE
) {
2081 /* redzoning only works with word aligned caches */
2082 align
= BYTES_PER_WORD
;
2084 /* add space for red zone words */
2085 cachep
->obj_offset
+= BYTES_PER_WORD
;
2086 size
+= 2 * BYTES_PER_WORD
;
2088 if (flags
& SLAB_STORE_USER
) {
2089 /* user store requires word alignment and
2090 * one word storage behind the end of the real
2093 align
= BYTES_PER_WORD
;
2094 size
+= BYTES_PER_WORD
;
2096 #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
2097 if (size
>= malloc_sizes
[INDEX_L3
+ 1].cs_size
2098 && cachep
->obj_size
> cache_line_size() && size
< PAGE_SIZE
) {
2099 cachep
->obj_offset
+= PAGE_SIZE
- size
;
2106 * Determine if the slab management is 'on' or 'off' slab.
2107 * (bootstrapping cannot cope with offslab caches so don't do
2110 if ((size
>= (PAGE_SIZE
>> 3)) && !slab_early_init
)
2112 * Size is large, assume best to place the slab management obj
2113 * off-slab (should allow better packing of objs).
2115 flags
|= CFLGS_OFF_SLAB
;
2117 size
= ALIGN(size
, align
);
2119 left_over
= calculate_slab_order(cachep
, size
, align
, flags
);
2122 printk("kmem_cache_create: couldn't create cache %s.\n", name
);
2123 kmem_cache_free(&cache_cache
, cachep
);
2127 slab_size
= ALIGN(cachep
->num
* sizeof(kmem_bufctl_t
)
2128 + sizeof(struct slab
), align
);
2131 * If the slab has been placed off-slab, and we have enough space then
2132 * move it on-slab. This is at the expense of any extra colouring.
2134 if (flags
& CFLGS_OFF_SLAB
&& left_over
>= slab_size
) {
2135 flags
&= ~CFLGS_OFF_SLAB
;
2136 left_over
-= slab_size
;
2139 if (flags
& CFLGS_OFF_SLAB
) {
2140 /* really off slab. No need for manual alignment */
2142 cachep
->num
* sizeof(kmem_bufctl_t
) + sizeof(struct slab
);
2145 cachep
->colour_off
= cache_line_size();
2146 /* Offset must be a multiple of the alignment. */
2147 if (cachep
->colour_off
< align
)
2148 cachep
->colour_off
= align
;
2149 cachep
->colour
= left_over
/ cachep
->colour_off
;
2150 cachep
->slab_size
= slab_size
;
2151 cachep
->flags
= flags
;
2152 cachep
->gfpflags
= 0;
2153 if (flags
& SLAB_CACHE_DMA
)
2154 cachep
->gfpflags
|= GFP_DMA
;
2155 cachep
->buffer_size
= size
;
2157 if (flags
& CFLGS_OFF_SLAB
)
2158 cachep
->slabp_cache
= kmem_find_general_cachep(slab_size
, 0u);
2159 cachep
->ctor
= ctor
;
2160 cachep
->dtor
= dtor
;
2161 cachep
->name
= name
;
2164 setup_cpu_cache(cachep
);
2166 /* cache setup completed, link it into the list */
2167 list_add(&cachep
->next
, &cache_chain
);
2169 if (!cachep
&& (flags
& SLAB_PANIC
))
2170 panic("kmem_cache_create(): failed to create slab `%s'\n",
2172 mutex_unlock(&cache_chain_mutex
);
2173 unlock_cpu_hotplug();
2176 EXPORT_SYMBOL(kmem_cache_create
);
2179 static void check_irq_off(void)
2181 BUG_ON(!irqs_disabled());
2184 static void check_irq_on(void)
2186 BUG_ON(irqs_disabled());
2189 static void check_spinlock_acquired(struct kmem_cache
*cachep
)
2193 assert_spin_locked(&cachep
->nodelists
[numa_node_id()]->list_lock
);
2197 static void check_spinlock_acquired_node(struct kmem_cache
*cachep
, int node
)
2201 assert_spin_locked(&cachep
->nodelists
[node
]->list_lock
);
2206 #define check_irq_off() do { } while(0)
2207 #define check_irq_on() do { } while(0)
2208 #define check_spinlock_acquired(x) do { } while(0)
2209 #define check_spinlock_acquired_node(x, y) do { } while(0)
2212 static void drain_array(struct kmem_cache
*cachep
, struct kmem_list3
*l3
,
2213 struct array_cache
*ac
,
2214 int force
, int node
);
2216 static void do_drain(void *arg
)
2218 struct kmem_cache
*cachep
= arg
;
2219 struct array_cache
*ac
;
2220 int node
= numa_node_id();
2223 ac
= cpu_cache_get(cachep
);
2224 spin_lock(&cachep
->nodelists
[node
]->list_lock
);
2225 free_block(cachep
, ac
->entry
, ac
->avail
, node
);
2226 spin_unlock(&cachep
->nodelists
[node
]->list_lock
);
2230 static void drain_cpu_caches(struct kmem_cache
*cachep
)
2232 struct kmem_list3
*l3
;
2235 on_each_cpu(do_drain
, cachep
, 1, 1);
2237 for_each_online_node(node
) {
2238 l3
= cachep
->nodelists
[node
];
2239 if (l3
&& l3
->alien
)
2240 drain_alien_cache(cachep
, l3
->alien
);
2243 for_each_online_node(node
) {
2244 l3
= cachep
->nodelists
[node
];
2246 drain_array(cachep
, l3
, l3
->shared
, 1, node
);
2250 static int __node_shrink(struct kmem_cache
*cachep
, int node
)
2253 struct kmem_list3
*l3
= cachep
->nodelists
[node
];
2257 struct list_head
*p
;
2259 p
= l3
->slabs_free
.prev
;
2260 if (p
== &l3
->slabs_free
)
2263 slabp
= list_entry(l3
->slabs_free
.prev
, struct slab
, list
);
2265 BUG_ON(slabp
->inuse
);
2267 list_del(&slabp
->list
);
2269 l3
->free_objects
-= cachep
->num
;
2270 spin_unlock_irq(&l3
->list_lock
);
2271 slab_destroy(cachep
, slabp
);
2272 spin_lock_irq(&l3
->list_lock
);
2274 ret
= !list_empty(&l3
->slabs_full
) || !list_empty(&l3
->slabs_partial
);
2278 static int __cache_shrink(struct kmem_cache
*cachep
)
2281 struct kmem_list3
*l3
;
2283 drain_cpu_caches(cachep
);
2286 for_each_online_node(i
) {
2287 l3
= cachep
->nodelists
[i
];
2289 spin_lock_irq(&l3
->list_lock
);
2290 ret
+= __node_shrink(cachep
, i
);
2291 spin_unlock_irq(&l3
->list_lock
);
2294 return (ret
? 1 : 0);
2298 * kmem_cache_shrink - Shrink a cache.
2299 * @cachep: The cache to shrink.
2301 * Releases as many slabs as possible for a cache.
2302 * To help debugging, a zero exit status indicates all slabs were released.
2304 int kmem_cache_shrink(struct kmem_cache
*cachep
)
2306 BUG_ON(!cachep
|| in_interrupt());
2308 return __cache_shrink(cachep
);
2310 EXPORT_SYMBOL(kmem_cache_shrink
);
2313 * kmem_cache_destroy - delete a cache
2314 * @cachep: the cache to destroy
2316 * Remove a struct kmem_cache object from the slab cache.
2317 * Returns 0 on success.
2319 * It is expected this function will be called by a module when it is
2320 * unloaded. This will remove the cache completely, and avoid a duplicate
2321 * cache being allocated each time a module is loaded and unloaded, if the
2322 * module doesn't have persistent in-kernel storage across loads and unloads.
2324 * The cache must be empty before calling this function.
2326 * The caller must guarantee that noone will allocate memory from the cache
2327 * during the kmem_cache_destroy().
2329 int kmem_cache_destroy(struct kmem_cache
*cachep
)
2332 struct kmem_list3
*l3
;
2334 BUG_ON(!cachep
|| in_interrupt());
2336 /* Don't let CPUs to come and go */
2339 /* Find the cache in the chain of caches. */
2340 mutex_lock(&cache_chain_mutex
);
2342 * the chain is never empty, cache_cache is never destroyed
2344 list_del(&cachep
->next
);
2345 mutex_unlock(&cache_chain_mutex
);
2347 if (__cache_shrink(cachep
)) {
2348 slab_error(cachep
, "Can't free all objects");
2349 mutex_lock(&cache_chain_mutex
);
2350 list_add(&cachep
->next
, &cache_chain
);
2351 mutex_unlock(&cache_chain_mutex
);
2352 unlock_cpu_hotplug();
2356 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
))
2359 for_each_online_cpu(i
)
2360 kfree(cachep
->array
[i
]);
2362 /* NUMA: free the list3 structures */
2363 for_each_online_node(i
) {
2364 l3
= cachep
->nodelists
[i
];
2367 free_alien_cache(l3
->alien
);
2371 kmem_cache_free(&cache_cache
, cachep
);
2372 unlock_cpu_hotplug();
2375 EXPORT_SYMBOL(kmem_cache_destroy
);
2377 /* Get the memory for a slab management obj. */
2378 static struct slab
*alloc_slabmgmt(struct kmem_cache
*cachep
, void *objp
,
2379 int colour_off
, gfp_t local_flags
,
2384 if (OFF_SLAB(cachep
)) {
2385 /* Slab management obj is off-slab. */
2386 slabp
= kmem_cache_alloc_node(cachep
->slabp_cache
,
2387 local_flags
, nodeid
);
2391 slabp
= objp
+ colour_off
;
2392 colour_off
+= cachep
->slab_size
;
2395 slabp
->colouroff
= colour_off
;
2396 slabp
->s_mem
= objp
+ colour_off
;
2397 slabp
->nodeid
= nodeid
;
2401 static inline kmem_bufctl_t
*slab_bufctl(struct slab
*slabp
)
2403 return (kmem_bufctl_t
*) (slabp
+ 1);
2406 static void cache_init_objs(struct kmem_cache
*cachep
,
2407 struct slab
*slabp
, unsigned long ctor_flags
)
2411 for (i
= 0; i
< cachep
->num
; i
++) {
2412 void *objp
= index_to_obj(cachep
, slabp
, i
);
2414 /* need to poison the objs? */
2415 if (cachep
->flags
& SLAB_POISON
)
2416 poison_obj(cachep
, objp
, POISON_FREE
);
2417 if (cachep
->flags
& SLAB_STORE_USER
)
2418 *dbg_userword(cachep
, objp
) = NULL
;
2420 if (cachep
->flags
& SLAB_RED_ZONE
) {
2421 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2422 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2425 * Constructors are not allowed to allocate memory from the same
2426 * cache which they are a constructor for. Otherwise, deadlock.
2427 * They must also be threaded.
2429 if (cachep
->ctor
&& !(cachep
->flags
& SLAB_POISON
))
2430 cachep
->ctor(objp
+ obj_offset(cachep
), cachep
,
2433 if (cachep
->flags
& SLAB_RED_ZONE
) {
2434 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
2435 slab_error(cachep
, "constructor overwrote the"
2436 " end of an object");
2437 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
2438 slab_error(cachep
, "constructor overwrote the"
2439 " start of an object");
2441 if ((cachep
->buffer_size
% PAGE_SIZE
) == 0 &&
2442 OFF_SLAB(cachep
) && cachep
->flags
& SLAB_POISON
)
2443 kernel_map_pages(virt_to_page(objp
),
2444 cachep
->buffer_size
/ PAGE_SIZE
, 0);
2447 cachep
->ctor(objp
, cachep
, ctor_flags
);
2449 slab_bufctl(slabp
)[i
] = i
+ 1;
2451 slab_bufctl(slabp
)[i
- 1] = BUFCTL_END
;
2455 static void kmem_flagcheck(struct kmem_cache
*cachep
, gfp_t flags
)
2457 if (flags
& SLAB_DMA
)
2458 BUG_ON(!(cachep
->gfpflags
& GFP_DMA
));
2460 BUG_ON(cachep
->gfpflags
& GFP_DMA
);
2463 static void *slab_get_obj(struct kmem_cache
*cachep
, struct slab
*slabp
,
2466 void *objp
= index_to_obj(cachep
, slabp
, slabp
->free
);
2470 next
= slab_bufctl(slabp
)[slabp
->free
];
2472 slab_bufctl(slabp
)[slabp
->free
] = BUFCTL_FREE
;
2473 WARN_ON(slabp
->nodeid
!= nodeid
);
2480 static void slab_put_obj(struct kmem_cache
*cachep
, struct slab
*slabp
,
2481 void *objp
, int nodeid
)
2483 unsigned int objnr
= obj_to_index(cachep
, slabp
, objp
);
2486 /* Verify that the slab belongs to the intended node */
2487 WARN_ON(slabp
->nodeid
!= nodeid
);
2489 if (slab_bufctl(slabp
)[objnr
] + 1 <= SLAB_LIMIT
+ 1) {
2490 printk(KERN_ERR
"slab: double free detected in cache "
2491 "'%s', objp %p\n", cachep
->name
, objp
);
2495 slab_bufctl(slabp
)[objnr
] = slabp
->free
;
2496 slabp
->free
= objnr
;
2501 * Map pages beginning at addr to the given cache and slab. This is required
2502 * for the slab allocator to be able to lookup the cache and slab of a
2503 * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
2505 static void slab_map_pages(struct kmem_cache
*cache
, struct slab
*slab
,
2511 page
= virt_to_page(addr
);
2514 if (likely(!PageCompound(page
)))
2515 nr_pages
<<= cache
->gfporder
;
2518 page_set_cache(page
, cache
);
2519 page_set_slab(page
, slab
);
2521 } while (--nr_pages
);
2525 * Grow (by 1) the number of slabs within a cache. This is called by
2526 * kmem_cache_alloc() when there are no active objs left in a cache.
2528 static int cache_grow(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
2534 unsigned long ctor_flags
;
2535 struct kmem_list3
*l3
;
2538 * Be lazy and only check for valid flags here, keeping it out of the
2539 * critical path in kmem_cache_alloc().
2541 BUG_ON(flags
& ~(SLAB_DMA
| SLAB_LEVEL_MASK
| SLAB_NO_GROW
));
2542 if (flags
& SLAB_NO_GROW
)
2545 ctor_flags
= SLAB_CTOR_CONSTRUCTOR
;
2546 local_flags
= (flags
& SLAB_LEVEL_MASK
);
2547 if (!(local_flags
& __GFP_WAIT
))
2549 * Not allowed to sleep. Need to tell a constructor about
2550 * this - it might need to know...
2552 ctor_flags
|= SLAB_CTOR_ATOMIC
;
2554 /* Take the l3 list lock to change the colour_next on this node */
2556 l3
= cachep
->nodelists
[nodeid
];
2557 spin_lock(&l3
->list_lock
);
2559 /* Get colour for the slab, and cal the next value. */
2560 offset
= l3
->colour_next
;
2562 if (l3
->colour_next
>= cachep
->colour
)
2563 l3
->colour_next
= 0;
2564 spin_unlock(&l3
->list_lock
);
2566 offset
*= cachep
->colour_off
;
2568 if (local_flags
& __GFP_WAIT
)
2572 * The test for missing atomic flag is performed here, rather than
2573 * the more obvious place, simply to reduce the critical path length
2574 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2575 * will eventually be caught here (where it matters).
2577 kmem_flagcheck(cachep
, flags
);
2580 * Get mem for the objs. Attempt to allocate a physical page from
2583 objp
= kmem_getpages(cachep
, flags
, nodeid
);
2587 /* Get slab management. */
2588 slabp
= alloc_slabmgmt(cachep
, objp
, offset
, local_flags
, nodeid
);
2592 slabp
->nodeid
= nodeid
;
2593 slab_map_pages(cachep
, slabp
, objp
);
2595 cache_init_objs(cachep
, slabp
, ctor_flags
);
2597 if (local_flags
& __GFP_WAIT
)
2598 local_irq_disable();
2600 spin_lock(&l3
->list_lock
);
2602 /* Make slab active. */
2603 list_add_tail(&slabp
->list
, &(l3
->slabs_free
));
2604 STATS_INC_GROWN(cachep
);
2605 l3
->free_objects
+= cachep
->num
;
2606 spin_unlock(&l3
->list_lock
);
2609 kmem_freepages(cachep
, objp
);
2611 if (local_flags
& __GFP_WAIT
)
2612 local_irq_disable();
2619 * Perform extra freeing checks:
2620 * - detect bad pointers.
2621 * - POISON/RED_ZONE checking
2622 * - destructor calls, for caches with POISON+dtor
2624 static void kfree_debugcheck(const void *objp
)
2628 if (!virt_addr_valid(objp
)) {
2629 printk(KERN_ERR
"kfree_debugcheck: out of range ptr %lxh.\n",
2630 (unsigned long)objp
);
2633 page
= virt_to_page(objp
);
2634 if (!PageSlab(page
)) {
2635 printk(KERN_ERR
"kfree_debugcheck: bad ptr %lxh.\n",
2636 (unsigned long)objp
);
2641 static inline void verify_redzone_free(struct kmem_cache
*cache
, void *obj
)
2643 unsigned long redzone1
, redzone2
;
2645 redzone1
= *dbg_redzone1(cache
, obj
);
2646 redzone2
= *dbg_redzone2(cache
, obj
);
2651 if (redzone1
== RED_ACTIVE
&& redzone2
== RED_ACTIVE
)
2654 if (redzone1
== RED_INACTIVE
&& redzone2
== RED_INACTIVE
)
2655 slab_error(cache
, "double free detected");
2657 slab_error(cache
, "memory outside object was overwritten");
2659 printk(KERN_ERR
"%p: redzone 1:0x%lx, redzone 2:0x%lx.\n",
2660 obj
, redzone1
, redzone2
);
2663 static void *cache_free_debugcheck(struct kmem_cache
*cachep
, void *objp
,
2670 objp
-= obj_offset(cachep
);
2671 kfree_debugcheck(objp
);
2672 page
= virt_to_page(objp
);
2674 slabp
= page_get_slab(page
);
2676 if (cachep
->flags
& SLAB_RED_ZONE
) {
2677 verify_redzone_free(cachep
, objp
);
2678 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2679 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2681 if (cachep
->flags
& SLAB_STORE_USER
)
2682 *dbg_userword(cachep
, objp
) = caller
;
2684 objnr
= obj_to_index(cachep
, slabp
, objp
);
2686 BUG_ON(objnr
>= cachep
->num
);
2687 BUG_ON(objp
!= index_to_obj(cachep
, slabp
, objnr
));
2689 if (cachep
->flags
& SLAB_DEBUG_INITIAL
) {
2691 * Need to call the slab's constructor so the caller can
2692 * perform a verify of its state (debugging). Called without
2693 * the cache-lock held.
2695 cachep
->ctor(objp
+ obj_offset(cachep
),
2696 cachep
, SLAB_CTOR_CONSTRUCTOR
| SLAB_CTOR_VERIFY
);
2698 if (cachep
->flags
& SLAB_POISON
&& cachep
->dtor
) {
2699 /* we want to cache poison the object,
2700 * call the destruction callback
2702 cachep
->dtor(objp
+ obj_offset(cachep
), cachep
, 0);
2704 #ifdef CONFIG_DEBUG_SLAB_LEAK
2705 slab_bufctl(slabp
)[objnr
] = BUFCTL_FREE
;
2707 if (cachep
->flags
& SLAB_POISON
) {
2708 #ifdef CONFIG_DEBUG_PAGEALLOC
2709 if ((cachep
->buffer_size
% PAGE_SIZE
)==0 && OFF_SLAB(cachep
)) {
2710 store_stackinfo(cachep
, objp
, (unsigned long)caller
);
2711 kernel_map_pages(virt_to_page(objp
),
2712 cachep
->buffer_size
/ PAGE_SIZE
, 0);
2714 poison_obj(cachep
, objp
, POISON_FREE
);
2717 poison_obj(cachep
, objp
, POISON_FREE
);
2723 static void check_slabp(struct kmem_cache
*cachep
, struct slab
*slabp
)
2728 /* Check slab's freelist to see if this obj is there. */
2729 for (i
= slabp
->free
; i
!= BUFCTL_END
; i
= slab_bufctl(slabp
)[i
]) {
2731 if (entries
> cachep
->num
|| i
>= cachep
->num
)
2734 if (entries
!= cachep
->num
- slabp
->inuse
) {
2736 printk(KERN_ERR
"slab: Internal list corruption detected in "
2737 "cache '%s'(%d), slabp %p(%d). Hexdump:\n",
2738 cachep
->name
, cachep
->num
, slabp
, slabp
->inuse
);
2740 i
< sizeof(*slabp
) + cachep
->num
* sizeof(kmem_bufctl_t
);
2743 printk("\n%03x:", i
);
2744 printk(" %02x", ((unsigned char *)slabp
)[i
]);
2751 #define kfree_debugcheck(x) do { } while(0)
2752 #define cache_free_debugcheck(x,objp,z) (objp)
2753 #define check_slabp(x,y) do { } while(0)
2756 static void *cache_alloc_refill(struct kmem_cache
*cachep
, gfp_t flags
)
2759 struct kmem_list3
*l3
;
2760 struct array_cache
*ac
;
2763 ac
= cpu_cache_get(cachep
);
2765 batchcount
= ac
->batchcount
;
2766 if (!ac
->touched
&& batchcount
> BATCHREFILL_LIMIT
) {
2768 * If there was little recent activity on this cache, then
2769 * perform only a partial refill. Otherwise we could generate
2772 batchcount
= BATCHREFILL_LIMIT
;
2774 l3
= cachep
->nodelists
[numa_node_id()];
2776 BUG_ON(ac
->avail
> 0 || !l3
);
2777 spin_lock(&l3
->list_lock
);
2779 /* See if we can refill from the shared array */
2780 if (l3
->shared
&& transfer_objects(ac
, l3
->shared
, batchcount
))
2783 while (batchcount
> 0) {
2784 struct list_head
*entry
;
2786 /* Get slab alloc is to come from. */
2787 entry
= l3
->slabs_partial
.next
;
2788 if (entry
== &l3
->slabs_partial
) {
2789 l3
->free_touched
= 1;
2790 entry
= l3
->slabs_free
.next
;
2791 if (entry
== &l3
->slabs_free
)
2795 slabp
= list_entry(entry
, struct slab
, list
);
2796 check_slabp(cachep
, slabp
);
2797 check_spinlock_acquired(cachep
);
2798 while (slabp
->inuse
< cachep
->num
&& batchcount
--) {
2799 STATS_INC_ALLOCED(cachep
);
2800 STATS_INC_ACTIVE(cachep
);
2801 STATS_SET_HIGH(cachep
);
2803 ac
->entry
[ac
->avail
++] = slab_get_obj(cachep
, slabp
,
2806 check_slabp(cachep
, slabp
);
2808 /* move slabp to correct slabp list: */
2809 list_del(&slabp
->list
);
2810 if (slabp
->free
== BUFCTL_END
)
2811 list_add(&slabp
->list
, &l3
->slabs_full
);
2813 list_add(&slabp
->list
, &l3
->slabs_partial
);
2817 l3
->free_objects
-= ac
->avail
;
2819 spin_unlock(&l3
->list_lock
);
2821 if (unlikely(!ac
->avail
)) {
2823 x
= cache_grow(cachep
, flags
, numa_node_id());
2825 /* cache_grow can reenable interrupts, then ac could change. */
2826 ac
= cpu_cache_get(cachep
);
2827 if (!x
&& ac
->avail
== 0) /* no objects in sight? abort */
2830 if (!ac
->avail
) /* objects refilled by interrupt? */
2834 return ac
->entry
[--ac
->avail
];
2837 static inline void cache_alloc_debugcheck_before(struct kmem_cache
*cachep
,
2840 might_sleep_if(flags
& __GFP_WAIT
);
2842 kmem_flagcheck(cachep
, flags
);
2847 static void *cache_alloc_debugcheck_after(struct kmem_cache
*cachep
,
2848 gfp_t flags
, void *objp
, void *caller
)
2852 if (cachep
->flags
& SLAB_POISON
) {
2853 #ifdef CONFIG_DEBUG_PAGEALLOC
2854 if ((cachep
->buffer_size
% PAGE_SIZE
) == 0 && OFF_SLAB(cachep
))
2855 kernel_map_pages(virt_to_page(objp
),
2856 cachep
->buffer_size
/ PAGE_SIZE
, 1);
2858 check_poison_obj(cachep
, objp
);
2860 check_poison_obj(cachep
, objp
);
2862 poison_obj(cachep
, objp
, POISON_INUSE
);
2864 if (cachep
->flags
& SLAB_STORE_USER
)
2865 *dbg_userword(cachep
, objp
) = caller
;
2867 if (cachep
->flags
& SLAB_RED_ZONE
) {
2868 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
||
2869 *dbg_redzone2(cachep
, objp
) != RED_INACTIVE
) {
2870 slab_error(cachep
, "double free, or memory outside"
2871 " object was overwritten");
2873 "%p: redzone 1:0x%lx, redzone 2:0x%lx\n",
2874 objp
, *dbg_redzone1(cachep
, objp
),
2875 *dbg_redzone2(cachep
, objp
));
2877 *dbg_redzone1(cachep
, objp
) = RED_ACTIVE
;
2878 *dbg_redzone2(cachep
, objp
) = RED_ACTIVE
;
2880 #ifdef CONFIG_DEBUG_SLAB_LEAK
2885 slabp
= page_get_slab(virt_to_page(objp
));
2886 objnr
= (unsigned)(objp
- slabp
->s_mem
) / cachep
->buffer_size
;
2887 slab_bufctl(slabp
)[objnr
] = BUFCTL_ACTIVE
;
2890 objp
+= obj_offset(cachep
);
2891 if (cachep
->ctor
&& cachep
->flags
& SLAB_POISON
) {
2892 unsigned long ctor_flags
= SLAB_CTOR_CONSTRUCTOR
;
2894 if (!(flags
& __GFP_WAIT
))
2895 ctor_flags
|= SLAB_CTOR_ATOMIC
;
2897 cachep
->ctor(objp
, cachep
, ctor_flags
);
2902 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
2905 static inline void *____cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2908 struct array_cache
*ac
;
2911 if (unlikely(current
->flags
& (PF_SPREAD_SLAB
| PF_MEMPOLICY
))) {
2912 objp
= alternate_node_alloc(cachep
, flags
);
2919 ac
= cpu_cache_get(cachep
);
2920 if (likely(ac
->avail
)) {
2921 STATS_INC_ALLOCHIT(cachep
);
2923 objp
= ac
->entry
[--ac
->avail
];
2925 STATS_INC_ALLOCMISS(cachep
);
2926 objp
= cache_alloc_refill(cachep
, flags
);
2931 static __always_inline
void *__cache_alloc(struct kmem_cache
*cachep
,
2932 gfp_t flags
, void *caller
)
2934 unsigned long save_flags
;
2937 cache_alloc_debugcheck_before(cachep
, flags
);
2939 local_irq_save(save_flags
);
2940 objp
= ____cache_alloc(cachep
, flags
);
2941 local_irq_restore(save_flags
);
2942 objp
= cache_alloc_debugcheck_after(cachep
, flags
, objp
,
2950 * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY.
2952 * If we are in_interrupt, then process context, including cpusets and
2953 * mempolicy, may not apply and should not be used for allocation policy.
2955 static void *alternate_node_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2957 int nid_alloc
, nid_here
;
2961 nid_alloc
= nid_here
= numa_node_id();
2962 if (cpuset_do_slab_mem_spread() && (cachep
->flags
& SLAB_MEM_SPREAD
))
2963 nid_alloc
= cpuset_mem_spread_node();
2964 else if (current
->mempolicy
)
2965 nid_alloc
= slab_node(current
->mempolicy
);
2966 if (nid_alloc
!= nid_here
)
2967 return __cache_alloc_node(cachep
, flags
, nid_alloc
);
2972 * A interface to enable slab creation on nodeid
2974 static void *__cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
,
2977 struct list_head
*entry
;
2979 struct kmem_list3
*l3
;
2983 l3
= cachep
->nodelists
[nodeid
];
2988 spin_lock(&l3
->list_lock
);
2989 entry
= l3
->slabs_partial
.next
;
2990 if (entry
== &l3
->slabs_partial
) {
2991 l3
->free_touched
= 1;
2992 entry
= l3
->slabs_free
.next
;
2993 if (entry
== &l3
->slabs_free
)
2997 slabp
= list_entry(entry
, struct slab
, list
);
2998 check_spinlock_acquired_node(cachep
, nodeid
);
2999 check_slabp(cachep
, slabp
);
3001 STATS_INC_NODEALLOCS(cachep
);
3002 STATS_INC_ACTIVE(cachep
);
3003 STATS_SET_HIGH(cachep
);
3005 BUG_ON(slabp
->inuse
== cachep
->num
);
3007 obj
= slab_get_obj(cachep
, slabp
, nodeid
);
3008 check_slabp(cachep
, slabp
);
3010 /* move slabp to correct slabp list: */
3011 list_del(&slabp
->list
);
3013 if (slabp
->free
== BUFCTL_END
)
3014 list_add(&slabp
->list
, &l3
->slabs_full
);
3016 list_add(&slabp
->list
, &l3
->slabs_partial
);
3018 spin_unlock(&l3
->list_lock
);
3022 spin_unlock(&l3
->list_lock
);
3023 x
= cache_grow(cachep
, flags
, nodeid
);
3035 * Caller needs to acquire correct kmem_list's list_lock
3037 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int nr_objects
,
3041 struct kmem_list3
*l3
;
3043 for (i
= 0; i
< nr_objects
; i
++) {
3044 void *objp
= objpp
[i
];
3047 slabp
= virt_to_slab(objp
);
3048 l3
= cachep
->nodelists
[node
];
3049 list_del(&slabp
->list
);
3050 check_spinlock_acquired_node(cachep
, node
);
3051 check_slabp(cachep
, slabp
);
3052 slab_put_obj(cachep
, slabp
, objp
, node
);
3053 STATS_DEC_ACTIVE(cachep
);
3055 check_slabp(cachep
, slabp
);
3057 /* fixup slab chains */
3058 if (slabp
->inuse
== 0) {
3059 if (l3
->free_objects
> l3
->free_limit
) {
3060 l3
->free_objects
-= cachep
->num
;
3061 slab_destroy(cachep
, slabp
);
3063 list_add(&slabp
->list
, &l3
->slabs_free
);
3066 /* Unconditionally move a slab to the end of the
3067 * partial list on free - maximum time for the
3068 * other objects to be freed, too.
3070 list_add_tail(&slabp
->list
, &l3
->slabs_partial
);
3075 static void cache_flusharray(struct kmem_cache
*cachep
, struct array_cache
*ac
)
3078 struct kmem_list3
*l3
;
3079 int node
= numa_node_id();
3081 batchcount
= ac
->batchcount
;
3083 BUG_ON(!batchcount
|| batchcount
> ac
->avail
);
3086 l3
= cachep
->nodelists
[node
];
3087 spin_lock(&l3
->list_lock
);
3089 struct array_cache
*shared_array
= l3
->shared
;
3090 int max
= shared_array
->limit
- shared_array
->avail
;
3092 if (batchcount
> max
)
3094 memcpy(&(shared_array
->entry
[shared_array
->avail
]),
3095 ac
->entry
, sizeof(void *) * batchcount
);
3096 shared_array
->avail
+= batchcount
;
3101 free_block(cachep
, ac
->entry
, batchcount
, node
);
3106 struct list_head
*p
;
3108 p
= l3
->slabs_free
.next
;
3109 while (p
!= &(l3
->slabs_free
)) {
3112 slabp
= list_entry(p
, struct slab
, list
);
3113 BUG_ON(slabp
->inuse
);
3118 STATS_SET_FREEABLE(cachep
, i
);
3121 spin_unlock(&l3
->list_lock
);
3122 ac
->avail
-= batchcount
;
3123 memmove(ac
->entry
, &(ac
->entry
[batchcount
]), sizeof(void *)*ac
->avail
);
3127 * Release an obj back to its cache. If the obj has a constructed state, it must
3128 * be in this state _before_ it is released. Called with disabled ints.
3130 static inline void __cache_free(struct kmem_cache
*cachep
, void *objp
)
3132 struct array_cache
*ac
= cpu_cache_get(cachep
);
3135 objp
= cache_free_debugcheck(cachep
, objp
, __builtin_return_address(0));
3137 if (cache_free_alien(cachep
, objp
))
3140 if (likely(ac
->avail
< ac
->limit
)) {
3141 STATS_INC_FREEHIT(cachep
);
3142 ac
->entry
[ac
->avail
++] = objp
;
3145 STATS_INC_FREEMISS(cachep
);
3146 cache_flusharray(cachep
, ac
);
3147 ac
->entry
[ac
->avail
++] = objp
;
3152 * kmem_cache_alloc - Allocate an object
3153 * @cachep: The cache to allocate from.
3154 * @flags: See kmalloc().
3156 * Allocate an object from this cache. The flags are only relevant
3157 * if the cache has no available objects.
3159 void *kmem_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3161 return __cache_alloc(cachep
, flags
, __builtin_return_address(0));
3163 EXPORT_SYMBOL(kmem_cache_alloc
);
3166 * kmem_cache_alloc - Allocate an object. The memory is set to zero.
3167 * @cache: The cache to allocate from.
3168 * @flags: See kmalloc().
3170 * Allocate an object from this cache and set the allocated memory to zero.
3171 * The flags are only relevant if the cache has no available objects.
3173 void *kmem_cache_zalloc(struct kmem_cache
*cache
, gfp_t flags
)
3175 void *ret
= __cache_alloc(cache
, flags
, __builtin_return_address(0));
3177 memset(ret
, 0, obj_size(cache
));
3180 EXPORT_SYMBOL(kmem_cache_zalloc
);
3183 * kmem_ptr_validate - check if an untrusted pointer might
3185 * @cachep: the cache we're checking against
3186 * @ptr: pointer to validate
3188 * This verifies that the untrusted pointer looks sane:
3189 * it is _not_ a guarantee that the pointer is actually
3190 * part of the slab cache in question, but it at least
3191 * validates that the pointer can be dereferenced and
3192 * looks half-way sane.
3194 * Currently only used for dentry validation.
3196 int fastcall
kmem_ptr_validate(struct kmem_cache
*cachep
, void *ptr
)
3198 unsigned long addr
= (unsigned long)ptr
;
3199 unsigned long min_addr
= PAGE_OFFSET
;
3200 unsigned long align_mask
= BYTES_PER_WORD
- 1;
3201 unsigned long size
= cachep
->buffer_size
;
3204 if (unlikely(addr
< min_addr
))
3206 if (unlikely(addr
> (unsigned long)high_memory
- size
))
3208 if (unlikely(addr
& align_mask
))
3210 if (unlikely(!kern_addr_valid(addr
)))
3212 if (unlikely(!kern_addr_valid(addr
+ size
- 1)))
3214 page
= virt_to_page(ptr
);
3215 if (unlikely(!PageSlab(page
)))
3217 if (unlikely(page_get_cache(page
) != cachep
))
3226 * kmem_cache_alloc_node - Allocate an object on the specified node
3227 * @cachep: The cache to allocate from.
3228 * @flags: See kmalloc().
3229 * @nodeid: node number of the target node.
3231 * Identical to kmem_cache_alloc, except that this function is slow
3232 * and can sleep. And it will allocate memory on the given node, which
3233 * can improve the performance for cpu bound structures.
3234 * New and improved: it will now make sure that the object gets
3235 * put on the correct node list so that there is no false sharing.
3237 void *kmem_cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
3239 unsigned long save_flags
;
3242 cache_alloc_debugcheck_before(cachep
, flags
);
3243 local_irq_save(save_flags
);
3245 if (nodeid
== -1 || nodeid
== numa_node_id() ||
3246 !cachep
->nodelists
[nodeid
])
3247 ptr
= ____cache_alloc(cachep
, flags
);
3249 ptr
= __cache_alloc_node(cachep
, flags
, nodeid
);
3250 local_irq_restore(save_flags
);
3252 ptr
= cache_alloc_debugcheck_after(cachep
, flags
, ptr
,
3253 __builtin_return_address(0));
3257 EXPORT_SYMBOL(kmem_cache_alloc_node
);
3259 void *kmalloc_node(size_t size
, gfp_t flags
, int node
)
3261 struct kmem_cache
*cachep
;
3263 cachep
= kmem_find_general_cachep(size
, flags
);
3264 if (unlikely(cachep
== NULL
))
3266 return kmem_cache_alloc_node(cachep
, flags
, node
);
3268 EXPORT_SYMBOL(kmalloc_node
);
3272 * __do_kmalloc - allocate memory
3273 * @size: how many bytes of memory are required.
3274 * @flags: the type of memory to allocate (see kmalloc).
3275 * @caller: function caller for debug tracking of the caller
3277 static __always_inline
void *__do_kmalloc(size_t size
, gfp_t flags
,
3280 struct kmem_cache
*cachep
;
3282 /* If you want to save a few bytes .text space: replace
3284 * Then kmalloc uses the uninlined functions instead of the inline
3287 cachep
= __find_general_cachep(size
, flags
);
3288 if (unlikely(cachep
== NULL
))
3290 return __cache_alloc(cachep
, flags
, caller
);
3294 void *__kmalloc(size_t size
, gfp_t flags
)
3296 #ifndef CONFIG_DEBUG_SLAB
3297 return __do_kmalloc(size
, flags
, NULL
);
3299 return __do_kmalloc(size
, flags
, __builtin_return_address(0));
3302 EXPORT_SYMBOL(__kmalloc
);
3304 #ifdef CONFIG_DEBUG_SLAB
3305 void *__kmalloc_track_caller(size_t size
, gfp_t flags
, void *caller
)
3307 return __do_kmalloc(size
, flags
, caller
);
3309 EXPORT_SYMBOL(__kmalloc_track_caller
);
3314 * __alloc_percpu - allocate one copy of the object for every present
3315 * cpu in the system, zeroing them.
3316 * Objects should be dereferenced using the per_cpu_ptr macro only.
3318 * @size: how many bytes of memory are required.
3320 void *__alloc_percpu(size_t size
)
3323 struct percpu_data
*pdata
= kmalloc(sizeof(*pdata
), GFP_KERNEL
);
3329 * Cannot use for_each_online_cpu since a cpu may come online
3330 * and we have no way of figuring out how to fix the array
3331 * that we have allocated then....
3333 for_each_possible_cpu(i
) {
3334 int node
= cpu_to_node(i
);
3336 if (node_online(node
))
3337 pdata
->ptrs
[i
] = kmalloc_node(size
, GFP_KERNEL
, node
);
3339 pdata
->ptrs
[i
] = kmalloc(size
, GFP_KERNEL
);
3341 if (!pdata
->ptrs
[i
])
3343 memset(pdata
->ptrs
[i
], 0, size
);
3346 /* Catch derefs w/o wrappers */
3347 return (void *)(~(unsigned long)pdata
);
3351 if (!cpu_possible(i
))
3353 kfree(pdata
->ptrs
[i
]);
3358 EXPORT_SYMBOL(__alloc_percpu
);
3362 * kmem_cache_free - Deallocate an object
3363 * @cachep: The cache the allocation was from.
3364 * @objp: The previously allocated object.
3366 * Free an object which was previously allocated from this
3369 void kmem_cache_free(struct kmem_cache
*cachep
, void *objp
)
3371 unsigned long flags
;
3373 BUG_ON(virt_to_cache(objp
) != cachep
);
3375 local_irq_save(flags
);
3376 __cache_free(cachep
, objp
);
3377 local_irq_restore(flags
);
3379 EXPORT_SYMBOL(kmem_cache_free
);
3382 * kfree - free previously allocated memory
3383 * @objp: pointer returned by kmalloc.
3385 * If @objp is NULL, no operation is performed.
3387 * Don't free memory not originally allocated by kmalloc()
3388 * or you will run into trouble.
3390 void kfree(const void *objp
)
3392 struct kmem_cache
*c
;
3393 unsigned long flags
;
3395 if (unlikely(!objp
))
3397 local_irq_save(flags
);
3398 kfree_debugcheck(objp
);
3399 c
= virt_to_cache(objp
);
3400 mutex_debug_check_no_locks_freed(objp
, obj_size(c
));
3401 __cache_free(c
, (void *)objp
);
3402 local_irq_restore(flags
);
3404 EXPORT_SYMBOL(kfree
);
3408 * free_percpu - free previously allocated percpu memory
3409 * @objp: pointer returned by alloc_percpu.
3411 * Don't free memory not originally allocated by alloc_percpu()
3412 * The complemented objp is to check for that.
3414 void free_percpu(const void *objp
)
3417 struct percpu_data
*p
= (struct percpu_data
*)(~(unsigned long)objp
);
3420 * We allocate for all cpus so we cannot use for online cpu here.
3422 for_each_possible_cpu(i
)
3426 EXPORT_SYMBOL(free_percpu
);
3429 unsigned int kmem_cache_size(struct kmem_cache
*cachep
)
3431 return obj_size(cachep
);
3433 EXPORT_SYMBOL(kmem_cache_size
);
3435 const char *kmem_cache_name(struct kmem_cache
*cachep
)
3437 return cachep
->name
;
3439 EXPORT_SYMBOL_GPL(kmem_cache_name
);
3442 * This initializes kmem_list3 or resizes varioius caches for all nodes.
3444 static int alloc_kmemlist(struct kmem_cache
*cachep
)
3447 struct kmem_list3
*l3
;
3448 struct array_cache
*new_shared
;
3449 struct array_cache
**new_alien
;
3451 for_each_online_node(node
) {
3453 new_alien
= alloc_alien_cache(node
, cachep
->limit
);
3457 new_shared
= alloc_arraycache(node
,
3458 cachep
->shared
*cachep
->batchcount
,
3461 free_alien_cache(new_alien
);
3465 l3
= cachep
->nodelists
[node
];
3467 struct array_cache
*shared
= l3
->shared
;
3469 spin_lock_irq(&l3
->list_lock
);
3472 free_block(cachep
, shared
->entry
,
3473 shared
->avail
, node
);
3475 l3
->shared
= new_shared
;
3477 l3
->alien
= new_alien
;
3480 l3
->free_limit
= (1 + nr_cpus_node(node
)) *
3481 cachep
->batchcount
+ cachep
->num
;
3482 spin_unlock_irq(&l3
->list_lock
);
3484 free_alien_cache(new_alien
);
3487 l3
= kmalloc_node(sizeof(struct kmem_list3
), GFP_KERNEL
, node
);
3489 free_alien_cache(new_alien
);
3494 kmem_list3_init(l3
);
3495 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
+
3496 ((unsigned long)cachep
) % REAPTIMEOUT_LIST3
;
3497 l3
->shared
= new_shared
;
3498 l3
->alien
= new_alien
;
3499 l3
->free_limit
= (1 + nr_cpus_node(node
)) *
3500 cachep
->batchcount
+ cachep
->num
;
3501 cachep
->nodelists
[node
] = l3
;
3506 if (!cachep
->next
.next
) {
3507 /* Cache is not active yet. Roll back what we did */
3510 if (cachep
->nodelists
[node
]) {
3511 l3
= cachep
->nodelists
[node
];
3514 free_alien_cache(l3
->alien
);
3516 cachep
->nodelists
[node
] = NULL
;
3524 struct ccupdate_struct
{
3525 struct kmem_cache
*cachep
;
3526 struct array_cache
*new[NR_CPUS
];
3529 static void do_ccupdate_local(void *info
)
3531 struct ccupdate_struct
*new = info
;
3532 struct array_cache
*old
;
3535 old
= cpu_cache_get(new->cachep
);
3537 new->cachep
->array
[smp_processor_id()] = new->new[smp_processor_id()];
3538 new->new[smp_processor_id()] = old
;
3541 /* Always called with the cache_chain_mutex held */
3542 static int do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3543 int batchcount
, int shared
)
3545 struct ccupdate_struct
new;
3548 memset(&new.new, 0, sizeof(new.new));
3549 for_each_online_cpu(i
) {
3550 new.new[i
] = alloc_arraycache(cpu_to_node(i
), limit
,
3553 for (i
--; i
>= 0; i
--)
3558 new.cachep
= cachep
;
3560 on_each_cpu(do_ccupdate_local
, (void *)&new, 1, 1);
3563 cachep
->batchcount
= batchcount
;
3564 cachep
->limit
= limit
;
3565 cachep
->shared
= shared
;
3567 for_each_online_cpu(i
) {
3568 struct array_cache
*ccold
= new.new[i
];
3571 spin_lock_irq(&cachep
->nodelists
[cpu_to_node(i
)]->list_lock
);
3572 free_block(cachep
, ccold
->entry
, ccold
->avail
, cpu_to_node(i
));
3573 spin_unlock_irq(&cachep
->nodelists
[cpu_to_node(i
)]->list_lock
);
3577 err
= alloc_kmemlist(cachep
);
3579 printk(KERN_ERR
"alloc_kmemlist failed for %s, error %d.\n",
3580 cachep
->name
, -err
);
3586 /* Called with cache_chain_mutex held always */
3587 static void enable_cpucache(struct kmem_cache
*cachep
)
3593 * The head array serves three purposes:
3594 * - create a LIFO ordering, i.e. return objects that are cache-warm
3595 * - reduce the number of spinlock operations.
3596 * - reduce the number of linked list operations on the slab and
3597 * bufctl chains: array operations are cheaper.
3598 * The numbers are guessed, we should auto-tune as described by
3601 if (cachep
->buffer_size
> 131072)
3603 else if (cachep
->buffer_size
> PAGE_SIZE
)
3605 else if (cachep
->buffer_size
> 1024)
3607 else if (cachep
->buffer_size
> 256)
3613 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3614 * allocation behaviour: Most allocs on one cpu, most free operations
3615 * on another cpu. For these cases, an efficient object passing between
3616 * cpus is necessary. This is provided by a shared array. The array
3617 * replaces Bonwick's magazine layer.
3618 * On uniprocessor, it's functionally equivalent (but less efficient)
3619 * to a larger limit. Thus disabled by default.
3623 if (cachep
->buffer_size
<= PAGE_SIZE
)
3629 * With debugging enabled, large batchcount lead to excessively long
3630 * periods with disabled local interrupts. Limit the batchcount
3635 err
= do_tune_cpucache(cachep
, limit
, (limit
+ 1) / 2, shared
);
3637 printk(KERN_ERR
"enable_cpucache failed for %s, error %d.\n",
3638 cachep
->name
, -err
);
3642 * Drain an array if it contains any elements taking the l3 lock only if
3643 * necessary. Note that the l3 listlock also protects the array_cache
3644 * if drain_array() is used on the shared array.
3646 void drain_array(struct kmem_cache
*cachep
, struct kmem_list3
*l3
,
3647 struct array_cache
*ac
, int force
, int node
)
3651 if (!ac
|| !ac
->avail
)
3653 if (ac
->touched
&& !force
) {
3656 spin_lock_irq(&l3
->list_lock
);
3658 tofree
= force
? ac
->avail
: (ac
->limit
+ 4) / 5;
3659 if (tofree
> ac
->avail
)
3660 tofree
= (ac
->avail
+ 1) / 2;
3661 free_block(cachep
, ac
->entry
, tofree
, node
);
3662 ac
->avail
-= tofree
;
3663 memmove(ac
->entry
, &(ac
->entry
[tofree
]),
3664 sizeof(void *) * ac
->avail
);
3666 spin_unlock_irq(&l3
->list_lock
);
3671 * cache_reap - Reclaim memory from caches.
3672 * @unused: unused parameter
3674 * Called from workqueue/eventd every few seconds.
3676 * - clear the per-cpu caches for this CPU.
3677 * - return freeable pages to the main free memory pool.
3679 * If we cannot acquire the cache chain mutex then just give up - we'll try
3680 * again on the next iteration.
3682 static void cache_reap(void *unused
)
3684 struct kmem_cache
*searchp
;
3685 struct kmem_list3
*l3
;
3686 int node
= numa_node_id();
3688 if (!mutex_trylock(&cache_chain_mutex
)) {
3689 /* Give up. Setup the next iteration. */
3690 schedule_delayed_work(&__get_cpu_var(reap_work
),
3695 list_for_each_entry(searchp
, &cache_chain
, next
) {
3696 struct list_head
*p
;
3703 * We only take the l3 lock if absolutely necessary and we
3704 * have established with reasonable certainty that
3705 * we can do some work if the lock was obtained.
3707 l3
= searchp
->nodelists
[node
];
3709 reap_alien(searchp
, l3
);
3711 drain_array(searchp
, l3
, cpu_cache_get(searchp
), 0, node
);
3714 * These are racy checks but it does not matter
3715 * if we skip one check or scan twice.
3717 if (time_after(l3
->next_reap
, jiffies
))
3720 l3
->next_reap
= jiffies
+ REAPTIMEOUT_LIST3
;
3722 drain_array(searchp
, l3
, l3
->shared
, 0, node
);
3724 if (l3
->free_touched
) {
3725 l3
->free_touched
= 0;
3729 tofree
= (l3
->free_limit
+ 5 * searchp
->num
- 1) /
3733 * Do not lock if there are no free blocks.
3735 if (list_empty(&l3
->slabs_free
))
3738 spin_lock_irq(&l3
->list_lock
);
3739 p
= l3
->slabs_free
.next
;
3740 if (p
== &(l3
->slabs_free
)) {
3741 spin_unlock_irq(&l3
->list_lock
);
3745 slabp
= list_entry(p
, struct slab
, list
);
3746 BUG_ON(slabp
->inuse
);
3747 list_del(&slabp
->list
);
3748 STATS_INC_REAPED(searchp
);
3751 * Safe to drop the lock. The slab is no longer linked
3752 * to the cache. searchp cannot disappear, we hold
3755 l3
->free_objects
-= searchp
->num
;
3756 spin_unlock_irq(&l3
->list_lock
);
3757 slab_destroy(searchp
, slabp
);
3758 } while (--tofree
> 0);
3763 mutex_unlock(&cache_chain_mutex
);
3765 /* Set up the next iteration */
3766 schedule_delayed_work(&__get_cpu_var(reap_work
), REAPTIMEOUT_CPUC
);
3769 #ifdef CONFIG_PROC_FS
3771 static void print_slabinfo_header(struct seq_file
*m
)
3774 * Output format version, so at least we can change it
3775 * without _too_ many complaints.
3778 seq_puts(m
, "slabinfo - version: 2.1 (statistics)\n");
3780 seq_puts(m
, "slabinfo - version: 2.1\n");
3782 seq_puts(m
, "# name <active_objs> <num_objs> <objsize> "
3783 "<objperslab> <pagesperslab>");
3784 seq_puts(m
, " : tunables <limit> <batchcount> <sharedfactor>");
3785 seq_puts(m
, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
3787 seq_puts(m
, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
3788 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
3789 seq_puts(m
, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
3794 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
3797 struct list_head
*p
;
3799 mutex_lock(&cache_chain_mutex
);
3801 print_slabinfo_header(m
);
3802 p
= cache_chain
.next
;
3805 if (p
== &cache_chain
)
3808 return list_entry(p
, struct kmem_cache
, next
);
3811 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
3813 struct kmem_cache
*cachep
= p
;
3815 return cachep
->next
.next
== &cache_chain
?
3816 NULL
: list_entry(cachep
->next
.next
, struct kmem_cache
, next
);
3819 static void s_stop(struct seq_file
*m
, void *p
)
3821 mutex_unlock(&cache_chain_mutex
);
3824 static int s_show(struct seq_file
*m
, void *p
)
3826 struct kmem_cache
*cachep
= p
;
3828 unsigned long active_objs
;
3829 unsigned long num_objs
;
3830 unsigned long active_slabs
= 0;
3831 unsigned long num_slabs
, free_objects
= 0, shared_avail
= 0;
3835 struct kmem_list3
*l3
;
3839 for_each_online_node(node
) {
3840 l3
= cachep
->nodelists
[node
];
3845 spin_lock_irq(&l3
->list_lock
);
3847 list_for_each_entry(slabp
, &l3
->slabs_full
, list
) {
3848 if (slabp
->inuse
!= cachep
->num
&& !error
)
3849 error
= "slabs_full accounting error";
3850 active_objs
+= cachep
->num
;
3853 list_for_each_entry(slabp
, &l3
->slabs_partial
, list
) {
3854 if (slabp
->inuse
== cachep
->num
&& !error
)
3855 error
= "slabs_partial inuse accounting error";
3856 if (!slabp
->inuse
&& !error
)
3857 error
= "slabs_partial/inuse accounting error";
3858 active_objs
+= slabp
->inuse
;
3861 list_for_each_entry(slabp
, &l3
->slabs_free
, list
) {
3862 if (slabp
->inuse
&& !error
)
3863 error
= "slabs_free/inuse accounting error";
3866 free_objects
+= l3
->free_objects
;
3868 shared_avail
+= l3
->shared
->avail
;
3870 spin_unlock_irq(&l3
->list_lock
);
3872 num_slabs
+= active_slabs
;
3873 num_objs
= num_slabs
* cachep
->num
;
3874 if (num_objs
- active_objs
!= free_objects
&& !error
)
3875 error
= "free_objects accounting error";
3877 name
= cachep
->name
;
3879 printk(KERN_ERR
"slab: cache %s error: %s\n", name
, error
);
3881 seq_printf(m
, "%-17s %6lu %6lu %6u %4u %4d",
3882 name
, active_objs
, num_objs
, cachep
->buffer_size
,
3883 cachep
->num
, (1 << cachep
->gfporder
));
3884 seq_printf(m
, " : tunables %4u %4u %4u",
3885 cachep
->limit
, cachep
->batchcount
, cachep
->shared
);
3886 seq_printf(m
, " : slabdata %6lu %6lu %6lu",
3887 active_slabs
, num_slabs
, shared_avail
);
3890 unsigned long high
= cachep
->high_mark
;
3891 unsigned long allocs
= cachep
->num_allocations
;
3892 unsigned long grown
= cachep
->grown
;
3893 unsigned long reaped
= cachep
->reaped
;
3894 unsigned long errors
= cachep
->errors
;
3895 unsigned long max_freeable
= cachep
->max_freeable
;
3896 unsigned long node_allocs
= cachep
->node_allocs
;
3897 unsigned long node_frees
= cachep
->node_frees
;
3898 unsigned long overflows
= cachep
->node_overflow
;
3900 seq_printf(m
, " : globalstat %7lu %6lu %5lu %4lu \
3901 %4lu %4lu %4lu %4lu %4lu", allocs
, high
, grown
,
3902 reaped
, errors
, max_freeable
, node_allocs
,
3903 node_frees
, overflows
);
3907 unsigned long allochit
= atomic_read(&cachep
->allochit
);
3908 unsigned long allocmiss
= atomic_read(&cachep
->allocmiss
);
3909 unsigned long freehit
= atomic_read(&cachep
->freehit
);
3910 unsigned long freemiss
= atomic_read(&cachep
->freemiss
);
3912 seq_printf(m
, " : cpustat %6lu %6lu %6lu %6lu",
3913 allochit
, allocmiss
, freehit
, freemiss
);
3921 * slabinfo_op - iterator that generates /proc/slabinfo
3930 * num-pages-per-slab
3931 * + further values on SMP and with statistics enabled
3934 struct seq_operations slabinfo_op
= {
3941 #define MAX_SLABINFO_WRITE 128
3943 * slabinfo_write - Tuning for the slab allocator
3945 * @buffer: user buffer
3946 * @count: data length
3949 ssize_t
slabinfo_write(struct file
*file
, const char __user
* buffer
,
3950 size_t count
, loff_t
*ppos
)
3952 char kbuf
[MAX_SLABINFO_WRITE
+ 1], *tmp
;
3953 int limit
, batchcount
, shared
, res
;
3954 struct kmem_cache
*cachep
;
3956 if (count
> MAX_SLABINFO_WRITE
)
3958 if (copy_from_user(&kbuf
, buffer
, count
))
3960 kbuf
[MAX_SLABINFO_WRITE
] = '\0';
3962 tmp
= strchr(kbuf
, ' ');
3967 if (sscanf(tmp
, " %d %d %d", &limit
, &batchcount
, &shared
) != 3)
3970 /* Find the cache in the chain of caches. */
3971 mutex_lock(&cache_chain_mutex
);
3973 list_for_each_entry(cachep
, &cache_chain
, next
) {
3974 if (!strcmp(cachep
->name
, kbuf
)) {
3975 if (limit
< 1 || batchcount
< 1 ||
3976 batchcount
> limit
|| shared
< 0) {
3979 res
= do_tune_cpucache(cachep
, limit
,
3980 batchcount
, shared
);
3985 mutex_unlock(&cache_chain_mutex
);
3991 #ifdef CONFIG_DEBUG_SLAB_LEAK
3993 static void *leaks_start(struct seq_file
*m
, loff_t
*pos
)
3996 struct list_head
*p
;
3998 mutex_lock(&cache_chain_mutex
);
3999 p
= cache_chain
.next
;
4002 if (p
== &cache_chain
)
4005 return list_entry(p
, struct kmem_cache
, next
);
4008 static inline int add_caller(unsigned long *n
, unsigned long v
)
4018 unsigned long *q
= p
+ 2 * i
;
4032 memmove(p
+ 2, p
, n
[1] * 2 * sizeof(unsigned long) - ((void *)p
- (void *)n
));
4038 static void handle_slab(unsigned long *n
, struct kmem_cache
*c
, struct slab
*s
)
4044 for (i
= 0, p
= s
->s_mem
; i
< c
->num
; i
++, p
+= c
->buffer_size
) {
4045 if (slab_bufctl(s
)[i
] != BUFCTL_ACTIVE
)
4047 if (!add_caller(n
, (unsigned long)*dbg_userword(c
, p
)))
4052 static void show_symbol(struct seq_file
*m
, unsigned long address
)
4054 #ifdef CONFIG_KALLSYMS
4057 unsigned long offset
, size
;
4058 char namebuf
[KSYM_NAME_LEN
+1];
4060 name
= kallsyms_lookup(address
, &size
, &offset
, &modname
, namebuf
);
4063 seq_printf(m
, "%s+%#lx/%#lx", name
, offset
, size
);
4065 seq_printf(m
, " [%s]", modname
);
4069 seq_printf(m
, "%p", (void *)address
);
4072 static int leaks_show(struct seq_file
*m
, void *p
)
4074 struct kmem_cache
*cachep
= p
;
4076 struct kmem_list3
*l3
;
4078 unsigned long *n
= m
->private;
4082 if (!(cachep
->flags
& SLAB_STORE_USER
))
4084 if (!(cachep
->flags
& SLAB_RED_ZONE
))
4087 /* OK, we can do it */
4091 for_each_online_node(node
) {
4092 l3
= cachep
->nodelists
[node
];
4097 spin_lock_irq(&l3
->list_lock
);
4099 list_for_each_entry(slabp
, &l3
->slabs_full
, list
)
4100 handle_slab(n
, cachep
, slabp
);
4101 list_for_each_entry(slabp
, &l3
->slabs_partial
, list
)
4102 handle_slab(n
, cachep
, slabp
);
4103 spin_unlock_irq(&l3
->list_lock
);
4105 name
= cachep
->name
;
4107 /* Increase the buffer size */
4108 mutex_unlock(&cache_chain_mutex
);
4109 m
->private = kzalloc(n
[0] * 4 * sizeof(unsigned long), GFP_KERNEL
);
4111 /* Too bad, we are really out */
4113 mutex_lock(&cache_chain_mutex
);
4116 *(unsigned long *)m
->private = n
[0] * 2;
4118 mutex_lock(&cache_chain_mutex
);
4119 /* Now make sure this entry will be retried */
4123 for (i
= 0; i
< n
[1]; i
++) {
4124 seq_printf(m
, "%s: %lu ", name
, n
[2*i
+3]);
4125 show_symbol(m
, n
[2*i
+2]);
4131 struct seq_operations slabstats_op
= {
4132 .start
= leaks_start
,
4141 * ksize - get the actual amount of memory allocated for a given object
4142 * @objp: Pointer to the object
4144 * kmalloc may internally round up allocations and return more memory
4145 * than requested. ksize() can be used to determine the actual amount of
4146 * memory allocated. The caller may use this additional memory, even though
4147 * a smaller amount of memory was initially specified with the kmalloc call.
4148 * The caller must guarantee that objp points to a valid object previously
4149 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4150 * must not be freed during the duration of the call.
4152 unsigned int ksize(const void *objp
)
4154 if (unlikely(objp
== NULL
))
4157 return obj_size(virt_to_cache(objp
));