3 * Written by Mark Hemment, 1996/97.
4 * (markhe@nextd.demon.co.uk)
6 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
8 * Major cleanup, different bufctl logic, per-cpu arrays
9 * (c) 2000 Manfred Spraul
11 * Cleanup, make the head arrays unconditional, preparation for NUMA
12 * (c) 2002 Manfred Spraul
14 * An implementation of the Slab Allocator as described in outline in;
15 * UNIX Internals: The New Frontiers by Uresh Vahalia
16 * Pub: Prentice Hall ISBN 0-13-101908-2
17 * or with a little more detail in;
18 * The Slab Allocator: An Object-Caching Kernel Memory Allocator
19 * Jeff Bonwick (Sun Microsystems).
20 * Presented at: USENIX Summer 1994 Technical Conference
22 * The memory is organized in caches, one cache for each object type.
23 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
24 * Each cache consists out of many slabs (they are small (usually one
25 * page long) and always contiguous), and each slab contains multiple
26 * initialized objects.
28 * This means, that your constructor is used only for newly allocated
29 * slabs and you must pass objects with the same initializations to
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 'slab_mutex'.
72 * The sem is only needed when accessing/extending the cache-chain, which
73 * can never happen inside an interrupt (kmem_cache_create(),
74 * kmem_cache_shrink() and kmem_cache_reap()).
76 * At present, each engine can be growing a cache. This should be blocked.
78 * 15 March 2005. NUMA slab allocator.
79 * Shai Fultheim <shai@scalex86.org>.
80 * Shobhit Dayal <shobhit@calsoftinc.com>
81 * Alok N Kataria <alokk@calsoftinc.com>
82 * Christoph Lameter <christoph@lameter.com>
84 * Modified the slab allocator to be node aware on NUMA systems.
85 * Each node has its own list of partial, free and full slabs.
86 * All object allocations for a node occur from node specific slab lists.
89 #include <linux/slab.h>
91 #include <linux/poison.h>
92 #include <linux/swap.h>
93 #include <linux/cache.h>
94 #include <linux/interrupt.h>
95 #include <linux/init.h>
96 #include <linux/compiler.h>
97 #include <linux/cpuset.h>
98 #include <linux/proc_fs.h>
99 #include <linux/seq_file.h>
100 #include <linux/notifier.h>
101 #include <linux/kallsyms.h>
102 #include <linux/cpu.h>
103 #include <linux/sysctl.h>
104 #include <linux/module.h>
105 #include <linux/rcupdate.h>
106 #include <linux/string.h>
107 #include <linux/uaccess.h>
108 #include <linux/nodemask.h>
109 #include <linux/kmemleak.h>
110 #include <linux/mempolicy.h>
111 #include <linux/mutex.h>
112 #include <linux/fault-inject.h>
113 #include <linux/rtmutex.h>
114 #include <linux/reciprocal_div.h>
115 #include <linux/debugobjects.h>
116 #include <linux/kmemcheck.h>
117 #include <linux/memory.h>
118 #include <linux/prefetch.h>
120 #include <net/sock.h>
122 #include <asm/cacheflush.h>
123 #include <asm/tlbflush.h>
124 #include <asm/page.h>
126 #include <trace/events/kmem.h>
128 #include "internal.h"
133 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
134 * 0 for faster, smaller code (especially in the critical paths).
136 * STATS - 1 to collect stats for /proc/slabinfo.
137 * 0 for faster, smaller code (especially in the critical paths).
139 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
142 #ifdef CONFIG_DEBUG_SLAB
145 #define FORCED_DEBUG 1
149 #define FORCED_DEBUG 0
152 /* Shouldn't this be in a header file somewhere? */
153 #define BYTES_PER_WORD sizeof(void *)
154 #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
156 #ifndef ARCH_KMALLOC_FLAGS
157 #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
160 #define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \
161 <= SLAB_OBJ_MIN_SIZE) ? 1 : 0)
163 #if FREELIST_BYTE_INDEX
164 typedef unsigned char freelist_idx_t
;
166 typedef unsigned short freelist_idx_t
;
169 #define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1)
172 * true if a page was allocated from pfmemalloc reserves for network-based
175 static bool pfmemalloc_active __read_mostly
;
181 * - LIFO ordering, to hand out cache-warm objects from _alloc
182 * - reduce the number of linked list operations
183 * - reduce spinlock operations
185 * The limit is stored in the per-cpu structure to reduce the data cache
192 unsigned int batchcount
;
193 unsigned int touched
;
195 * Must have this definition in here for the proper
196 * alignment of array_cache. Also simplifies accessing
199 * Entries should not be directly dereferenced as
200 * entries belonging to slabs marked pfmemalloc will
201 * have the lower bits set SLAB_OBJ_PFMEMALLOC
207 struct array_cache ac
;
210 #define SLAB_OBJ_PFMEMALLOC 1
211 static inline bool is_obj_pfmemalloc(void *objp
)
213 return (unsigned long)objp
& SLAB_OBJ_PFMEMALLOC
;
216 static inline void set_obj_pfmemalloc(void **objp
)
218 *objp
= (void *)((unsigned long)*objp
| SLAB_OBJ_PFMEMALLOC
);
222 static inline void clear_obj_pfmemalloc(void **objp
)
224 *objp
= (void *)((unsigned long)*objp
& ~SLAB_OBJ_PFMEMALLOC
);
228 * Need this for bootstrapping a per node allocator.
230 #define NUM_INIT_LISTS (2 * MAX_NUMNODES)
231 static struct kmem_cache_node __initdata init_kmem_cache_node
[NUM_INIT_LISTS
];
232 #define CACHE_CACHE 0
233 #define SIZE_NODE (MAX_NUMNODES)
235 static int drain_freelist(struct kmem_cache
*cache
,
236 struct kmem_cache_node
*n
, int tofree
);
237 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int len
,
238 int node
, struct list_head
*list
);
239 static void slabs_destroy(struct kmem_cache
*cachep
, struct list_head
*list
);
240 static int enable_cpucache(struct kmem_cache
*cachep
, gfp_t gfp
);
241 static void cache_reap(struct work_struct
*unused
);
243 static int slab_early_init
= 1;
245 #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node))
247 static void kmem_cache_node_init(struct kmem_cache_node
*parent
)
249 INIT_LIST_HEAD(&parent
->slabs_full
);
250 INIT_LIST_HEAD(&parent
->slabs_partial
);
251 INIT_LIST_HEAD(&parent
->slabs_free
);
252 parent
->shared
= NULL
;
253 parent
->alien
= NULL
;
254 parent
->colour_next
= 0;
255 spin_lock_init(&parent
->list_lock
);
256 parent
->free_objects
= 0;
257 parent
->free_touched
= 0;
260 #define MAKE_LIST(cachep, listp, slab, nodeid) \
262 INIT_LIST_HEAD(listp); \
263 list_splice(&get_node(cachep, nodeid)->slab, listp); \
266 #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
268 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
269 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
270 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
273 #define CFLGS_OFF_SLAB (0x80000000UL)
274 #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
275 #define OFF_SLAB_MIN_SIZE (max_t(size_t, PAGE_SIZE >> 5, KMALLOC_MIN_SIZE + 1))
277 #define BATCHREFILL_LIMIT 16
279 * Optimization question: fewer reaps means less probability for unnessary
280 * cpucache drain/refill cycles.
282 * OTOH the cpuarrays can contain lots of objects,
283 * which could lock up otherwise freeable slabs.
285 #define REAPTIMEOUT_AC (2*HZ)
286 #define REAPTIMEOUT_NODE (4*HZ)
289 #define STATS_INC_ACTIVE(x) ((x)->num_active++)
290 #define STATS_DEC_ACTIVE(x) ((x)->num_active--)
291 #define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
292 #define STATS_INC_GROWN(x) ((x)->grown++)
293 #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
294 #define STATS_SET_HIGH(x) \
296 if ((x)->num_active > (x)->high_mark) \
297 (x)->high_mark = (x)->num_active; \
299 #define STATS_INC_ERR(x) ((x)->errors++)
300 #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
301 #define STATS_INC_NODEFREES(x) ((x)->node_frees++)
302 #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
303 #define STATS_SET_FREEABLE(x, i) \
305 if ((x)->max_freeable < i) \
306 (x)->max_freeable = i; \
308 #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
309 #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
310 #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
311 #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
313 #define STATS_INC_ACTIVE(x) do { } while (0)
314 #define STATS_DEC_ACTIVE(x) do { } while (0)
315 #define STATS_INC_ALLOCED(x) do { } while (0)
316 #define STATS_INC_GROWN(x) do { } while (0)
317 #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0)
318 #define STATS_SET_HIGH(x) do { } while (0)
319 #define STATS_INC_ERR(x) do { } while (0)
320 #define STATS_INC_NODEALLOCS(x) do { } while (0)
321 #define STATS_INC_NODEFREES(x) do { } while (0)
322 #define STATS_INC_ACOVERFLOW(x) do { } while (0)
323 #define STATS_SET_FREEABLE(x, i) do { } while (0)
324 #define STATS_INC_ALLOCHIT(x) do { } while (0)
325 #define STATS_INC_ALLOCMISS(x) do { } while (0)
326 #define STATS_INC_FREEHIT(x) do { } while (0)
327 #define STATS_INC_FREEMISS(x) do { } while (0)
333 * memory layout of objects:
335 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
336 * the end of an object is aligned with the end of the real
337 * allocation. Catches writes behind the end of the allocation.
338 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
340 * cachep->obj_offset: The real object.
341 * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
342 * cachep->size - 1* BYTES_PER_WORD: last caller address
343 * [BYTES_PER_WORD long]
345 static int obj_offset(struct kmem_cache
*cachep
)
347 return cachep
->obj_offset
;
350 static unsigned long long *dbg_redzone1(struct kmem_cache
*cachep
, void *objp
)
352 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
353 return (unsigned long long*) (objp
+ obj_offset(cachep
) -
354 sizeof(unsigned long long));
357 static unsigned long long *dbg_redzone2(struct kmem_cache
*cachep
, void *objp
)
359 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
360 if (cachep
->flags
& SLAB_STORE_USER
)
361 return (unsigned long long *)(objp
+ cachep
->size
-
362 sizeof(unsigned long long) -
364 return (unsigned long long *) (objp
+ cachep
->size
-
365 sizeof(unsigned long long));
368 static void **dbg_userword(struct kmem_cache
*cachep
, void *objp
)
370 BUG_ON(!(cachep
->flags
& SLAB_STORE_USER
));
371 return (void **)(objp
+ cachep
->size
- BYTES_PER_WORD
);
376 #define obj_offset(x) 0
377 #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
378 #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
379 #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
383 #ifdef CONFIG_DEBUG_SLAB_LEAK
385 static inline bool is_store_user_clean(struct kmem_cache
*cachep
)
387 return atomic_read(&cachep
->store_user_clean
) == 1;
390 static inline void set_store_user_clean(struct kmem_cache
*cachep
)
392 atomic_set(&cachep
->store_user_clean
, 1);
395 static inline void set_store_user_dirty(struct kmem_cache
*cachep
)
397 if (is_store_user_clean(cachep
))
398 atomic_set(&cachep
->store_user_clean
, 0);
402 static inline void set_store_user_dirty(struct kmem_cache
*cachep
) {}
407 * Do not go above this order unless 0 objects fit into the slab or
408 * overridden on the command line.
410 #define SLAB_MAX_ORDER_HI 1
411 #define SLAB_MAX_ORDER_LO 0
412 static int slab_max_order
= SLAB_MAX_ORDER_LO
;
413 static bool slab_max_order_set __initdata
;
415 static inline struct kmem_cache
*virt_to_cache(const void *obj
)
417 struct page
*page
= virt_to_head_page(obj
);
418 return page
->slab_cache
;
421 static inline void *index_to_obj(struct kmem_cache
*cache
, struct page
*page
,
424 return page
->s_mem
+ cache
->size
* idx
;
428 * We want to avoid an expensive divide : (offset / cache->size)
429 * Using the fact that size is a constant for a particular cache,
430 * we can replace (offset / cache->size) by
431 * reciprocal_divide(offset, cache->reciprocal_buffer_size)
433 static inline unsigned int obj_to_index(const struct kmem_cache
*cache
,
434 const struct page
*page
, void *obj
)
436 u32 offset
= (obj
- page
->s_mem
);
437 return reciprocal_divide(offset
, cache
->reciprocal_buffer_size
);
440 #define BOOT_CPUCACHE_ENTRIES 1
441 /* internal cache of cache description objs */
442 static struct kmem_cache kmem_cache_boot
= {
444 .limit
= BOOT_CPUCACHE_ENTRIES
,
446 .size
= sizeof(struct kmem_cache
),
447 .name
= "kmem_cache",
450 #define BAD_ALIEN_MAGIC 0x01020304ul
452 static DEFINE_PER_CPU(struct delayed_work
, slab_reap_work
);
454 static inline struct array_cache
*cpu_cache_get(struct kmem_cache
*cachep
)
456 return this_cpu_ptr(cachep
->cpu_cache
);
460 * Calculate the number of objects and left-over bytes for a given buffer size.
462 static void cache_estimate(unsigned long gfporder
, size_t buffer_size
,
463 unsigned long flags
, size_t *left_over
, unsigned int *num
)
465 size_t slab_size
= PAGE_SIZE
<< gfporder
;
468 * The slab management structure can be either off the slab or
469 * on it. For the latter case, the memory allocated for a
472 * - @buffer_size bytes for each object
473 * - One freelist_idx_t for each object
475 * We don't need to consider alignment of freelist because
476 * freelist will be at the end of slab page. The objects will be
477 * at the correct alignment.
479 * If the slab management structure is off the slab, then the
480 * alignment will already be calculated into the size. Because
481 * the slabs are all pages aligned, the objects will be at the
482 * correct alignment when allocated.
484 if (flags
& CFLGS_OFF_SLAB
) {
485 *num
= slab_size
/ buffer_size
;
486 *left_over
= slab_size
% buffer_size
;
488 *num
= slab_size
/ (buffer_size
+ sizeof(freelist_idx_t
));
489 *left_over
= slab_size
%
490 (buffer_size
+ sizeof(freelist_idx_t
));
495 #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
497 static void __slab_error(const char *function
, struct kmem_cache
*cachep
,
500 printk(KERN_ERR
"slab error in %s(): cache `%s': %s\n",
501 function
, cachep
->name
, msg
);
503 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
508 * By default on NUMA we use alien caches to stage the freeing of
509 * objects allocated from other nodes. This causes massive memory
510 * inefficiencies when using fake NUMA setup to split memory into a
511 * large number of small nodes, so it can be disabled on the command
515 static int use_alien_caches __read_mostly
= 1;
516 static int __init
noaliencache_setup(char *s
)
518 use_alien_caches
= 0;
521 __setup("noaliencache", noaliencache_setup
);
523 static int __init
slab_max_order_setup(char *str
)
525 get_option(&str
, &slab_max_order
);
526 slab_max_order
= slab_max_order
< 0 ? 0 :
527 min(slab_max_order
, MAX_ORDER
- 1);
528 slab_max_order_set
= true;
532 __setup("slab_max_order=", slab_max_order_setup
);
536 * Special reaping functions for NUMA systems called from cache_reap().
537 * These take care of doing round robin flushing of alien caches (containing
538 * objects freed on different nodes from which they were allocated) and the
539 * flushing of remote pcps by calling drain_node_pages.
541 static DEFINE_PER_CPU(unsigned long, slab_reap_node
);
543 static void init_reap_node(int cpu
)
547 node
= next_node(cpu_to_mem(cpu
), node_online_map
);
548 if (node
== MAX_NUMNODES
)
549 node
= first_node(node_online_map
);
551 per_cpu(slab_reap_node
, cpu
) = node
;
554 static void next_reap_node(void)
556 int node
= __this_cpu_read(slab_reap_node
);
558 node
= next_node(node
, node_online_map
);
559 if (unlikely(node
>= MAX_NUMNODES
))
560 node
= first_node(node_online_map
);
561 __this_cpu_write(slab_reap_node
, node
);
565 #define init_reap_node(cpu) do { } while (0)
566 #define next_reap_node(void) do { } while (0)
570 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
571 * via the workqueue/eventd.
572 * Add the CPU number into the expiration time to minimize the possibility of
573 * the CPUs getting into lockstep and contending for the global cache chain
576 static void start_cpu_timer(int cpu
)
578 struct delayed_work
*reap_work
= &per_cpu(slab_reap_work
, cpu
);
581 * When this gets called from do_initcalls via cpucache_init(),
582 * init_workqueues() has already run, so keventd will be setup
585 if (keventd_up() && reap_work
->work
.func
== NULL
) {
587 INIT_DEFERRABLE_WORK(reap_work
, cache_reap
);
588 schedule_delayed_work_on(cpu
, reap_work
,
589 __round_jiffies_relative(HZ
, cpu
));
593 static void init_arraycache(struct array_cache
*ac
, int limit
, int batch
)
596 * The array_cache structures contain pointers to free object.
597 * However, when such objects are allocated or transferred to another
598 * cache the pointers are not cleared and they could be counted as
599 * valid references during a kmemleak scan. Therefore, kmemleak must
600 * not scan such objects.
602 kmemleak_no_scan(ac
);
606 ac
->batchcount
= batch
;
611 static struct array_cache
*alloc_arraycache(int node
, int entries
,
612 int batchcount
, gfp_t gfp
)
614 size_t memsize
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
615 struct array_cache
*ac
= NULL
;
617 ac
= kmalloc_node(memsize
, gfp
, node
);
618 init_arraycache(ac
, entries
, batchcount
);
622 static inline bool is_slab_pfmemalloc(struct page
*page
)
624 return PageSlabPfmemalloc(page
);
627 /* Clears pfmemalloc_active if no slabs have pfmalloc set */
628 static void recheck_pfmemalloc_active(struct kmem_cache
*cachep
,
629 struct array_cache
*ac
)
631 struct kmem_cache_node
*n
= get_node(cachep
, numa_mem_id());
635 if (!pfmemalloc_active
)
638 spin_lock_irqsave(&n
->list_lock
, flags
);
639 list_for_each_entry(page
, &n
->slabs_full
, lru
)
640 if (is_slab_pfmemalloc(page
))
643 list_for_each_entry(page
, &n
->slabs_partial
, lru
)
644 if (is_slab_pfmemalloc(page
))
647 list_for_each_entry(page
, &n
->slabs_free
, lru
)
648 if (is_slab_pfmemalloc(page
))
651 pfmemalloc_active
= false;
653 spin_unlock_irqrestore(&n
->list_lock
, flags
);
656 static void *__ac_get_obj(struct kmem_cache
*cachep
, struct array_cache
*ac
,
657 gfp_t flags
, bool force_refill
)
660 void *objp
= ac
->entry
[--ac
->avail
];
662 /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */
663 if (unlikely(is_obj_pfmemalloc(objp
))) {
664 struct kmem_cache_node
*n
;
666 if (gfp_pfmemalloc_allowed(flags
)) {
667 clear_obj_pfmemalloc(&objp
);
671 /* The caller cannot use PFMEMALLOC objects, find another one */
672 for (i
= 0; i
< ac
->avail
; i
++) {
673 /* If a !PFMEMALLOC object is found, swap them */
674 if (!is_obj_pfmemalloc(ac
->entry
[i
])) {
676 ac
->entry
[i
] = ac
->entry
[ac
->avail
];
677 ac
->entry
[ac
->avail
] = objp
;
683 * If there are empty slabs on the slabs_free list and we are
684 * being forced to refill the cache, mark this one !pfmemalloc.
686 n
= get_node(cachep
, numa_mem_id());
687 if (!list_empty(&n
->slabs_free
) && force_refill
) {
688 struct page
*page
= virt_to_head_page(objp
);
689 ClearPageSlabPfmemalloc(page
);
690 clear_obj_pfmemalloc(&objp
);
691 recheck_pfmemalloc_active(cachep
, ac
);
695 /* No !PFMEMALLOC objects available */
703 static inline void *ac_get_obj(struct kmem_cache
*cachep
,
704 struct array_cache
*ac
, gfp_t flags
, bool force_refill
)
708 if (unlikely(sk_memalloc_socks()))
709 objp
= __ac_get_obj(cachep
, ac
, flags
, force_refill
);
711 objp
= ac
->entry
[--ac
->avail
];
716 static noinline
void *__ac_put_obj(struct kmem_cache
*cachep
,
717 struct array_cache
*ac
, void *objp
)
719 if (unlikely(pfmemalloc_active
)) {
720 /* Some pfmemalloc slabs exist, check if this is one */
721 struct page
*page
= virt_to_head_page(objp
);
722 if (PageSlabPfmemalloc(page
))
723 set_obj_pfmemalloc(&objp
);
729 static inline void ac_put_obj(struct kmem_cache
*cachep
, struct array_cache
*ac
,
732 if (unlikely(sk_memalloc_socks()))
733 objp
= __ac_put_obj(cachep
, ac
, objp
);
735 ac
->entry
[ac
->avail
++] = objp
;
739 * Transfer objects in one arraycache to another.
740 * Locking must be handled by the caller.
742 * Return the number of entries transferred.
744 static int transfer_objects(struct array_cache
*to
,
745 struct array_cache
*from
, unsigned int max
)
747 /* Figure out how many entries to transfer */
748 int nr
= min3(from
->avail
, max
, to
->limit
- to
->avail
);
753 memcpy(to
->entry
+ to
->avail
, from
->entry
+ from
->avail
-nr
,
763 #define drain_alien_cache(cachep, alien) do { } while (0)
764 #define reap_alien(cachep, n) do { } while (0)
766 static inline struct alien_cache
**alloc_alien_cache(int node
,
767 int limit
, gfp_t gfp
)
769 return (struct alien_cache
**)BAD_ALIEN_MAGIC
;
772 static inline void free_alien_cache(struct alien_cache
**ac_ptr
)
776 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
781 static inline void *alternate_node_alloc(struct kmem_cache
*cachep
,
787 static inline void *____cache_alloc_node(struct kmem_cache
*cachep
,
788 gfp_t flags
, int nodeid
)
793 static inline gfp_t
gfp_exact_node(gfp_t flags
)
798 #else /* CONFIG_NUMA */
800 static void *____cache_alloc_node(struct kmem_cache
*, gfp_t
, int);
801 static void *alternate_node_alloc(struct kmem_cache
*, gfp_t
);
803 static struct alien_cache
*__alloc_alien_cache(int node
, int entries
,
804 int batch
, gfp_t gfp
)
806 size_t memsize
= sizeof(void *) * entries
+ sizeof(struct alien_cache
);
807 struct alien_cache
*alc
= NULL
;
809 alc
= kmalloc_node(memsize
, gfp
, node
);
810 init_arraycache(&alc
->ac
, entries
, batch
);
811 spin_lock_init(&alc
->lock
);
815 static struct alien_cache
**alloc_alien_cache(int node
, int limit
, gfp_t gfp
)
817 struct alien_cache
**alc_ptr
;
818 size_t memsize
= sizeof(void *) * nr_node_ids
;
823 alc_ptr
= kzalloc_node(memsize
, gfp
, node
);
828 if (i
== node
|| !node_online(i
))
830 alc_ptr
[i
] = __alloc_alien_cache(node
, limit
, 0xbaadf00d, gfp
);
832 for (i
--; i
>= 0; i
--)
841 static void free_alien_cache(struct alien_cache
**alc_ptr
)
852 static void __drain_alien_cache(struct kmem_cache
*cachep
,
853 struct array_cache
*ac
, int node
,
854 struct list_head
*list
)
856 struct kmem_cache_node
*n
= get_node(cachep
, node
);
859 spin_lock(&n
->list_lock
);
861 * Stuff objects into the remote nodes shared array first.
862 * That way we could avoid the overhead of putting the objects
863 * into the free lists and getting them back later.
866 transfer_objects(n
->shared
, ac
, ac
->limit
);
868 free_block(cachep
, ac
->entry
, ac
->avail
, node
, list
);
870 spin_unlock(&n
->list_lock
);
875 * Called from cache_reap() to regularly drain alien caches round robin.
877 static void reap_alien(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
)
879 int node
= __this_cpu_read(slab_reap_node
);
882 struct alien_cache
*alc
= n
->alien
[node
];
883 struct array_cache
*ac
;
887 if (ac
->avail
&& spin_trylock_irq(&alc
->lock
)) {
890 __drain_alien_cache(cachep
, ac
, node
, &list
);
891 spin_unlock_irq(&alc
->lock
);
892 slabs_destroy(cachep
, &list
);
898 static void drain_alien_cache(struct kmem_cache
*cachep
,
899 struct alien_cache
**alien
)
902 struct alien_cache
*alc
;
903 struct array_cache
*ac
;
906 for_each_online_node(i
) {
912 spin_lock_irqsave(&alc
->lock
, flags
);
913 __drain_alien_cache(cachep
, ac
, i
, &list
);
914 spin_unlock_irqrestore(&alc
->lock
, flags
);
915 slabs_destroy(cachep
, &list
);
920 static int __cache_free_alien(struct kmem_cache
*cachep
, void *objp
,
921 int node
, int page_node
)
923 struct kmem_cache_node
*n
;
924 struct alien_cache
*alien
= NULL
;
925 struct array_cache
*ac
;
928 n
= get_node(cachep
, node
);
929 STATS_INC_NODEFREES(cachep
);
930 if (n
->alien
&& n
->alien
[page_node
]) {
931 alien
= n
->alien
[page_node
];
933 spin_lock(&alien
->lock
);
934 if (unlikely(ac
->avail
== ac
->limit
)) {
935 STATS_INC_ACOVERFLOW(cachep
);
936 __drain_alien_cache(cachep
, ac
, page_node
, &list
);
938 ac_put_obj(cachep
, ac
, objp
);
939 spin_unlock(&alien
->lock
);
940 slabs_destroy(cachep
, &list
);
942 n
= get_node(cachep
, page_node
);
943 spin_lock(&n
->list_lock
);
944 free_block(cachep
, &objp
, 1, page_node
, &list
);
945 spin_unlock(&n
->list_lock
);
946 slabs_destroy(cachep
, &list
);
951 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
953 int page_node
= page_to_nid(virt_to_page(objp
));
954 int node
= numa_mem_id();
956 * Make sure we are not freeing a object from another node to the array
959 if (likely(node
== page_node
))
962 return __cache_free_alien(cachep
, objp
, node
, page_node
);
966 * Construct gfp mask to allocate from a specific node but do not direct reclaim
967 * or warn about failures. kswapd may still wake to reclaim in the background.
969 static inline gfp_t
gfp_exact_node(gfp_t flags
)
971 return (flags
| __GFP_THISNODE
| __GFP_NOWARN
) & ~__GFP_DIRECT_RECLAIM
;
976 * Allocates and initializes node for a node on each slab cache, used for
977 * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
978 * will be allocated off-node since memory is not yet online for the new node.
979 * When hotplugging memory or a cpu, existing node are not replaced if
982 * Must hold slab_mutex.
984 static int init_cache_node_node(int node
)
986 struct kmem_cache
*cachep
;
987 struct kmem_cache_node
*n
;
988 const size_t memsize
= sizeof(struct kmem_cache_node
);
990 list_for_each_entry(cachep
, &slab_caches
, list
) {
992 * Set up the kmem_cache_node for cpu before we can
993 * begin anything. Make sure some other cpu on this
994 * node has not already allocated this
996 n
= get_node(cachep
, node
);
998 n
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
1001 kmem_cache_node_init(n
);
1002 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
+
1003 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
1006 * The kmem_cache_nodes don't come and go as CPUs
1007 * come and go. slab_mutex is sufficient
1010 cachep
->node
[node
] = n
;
1013 spin_lock_irq(&n
->list_lock
);
1015 (1 + nr_cpus_node(node
)) *
1016 cachep
->batchcount
+ cachep
->num
;
1017 spin_unlock_irq(&n
->list_lock
);
1022 static inline int slabs_tofree(struct kmem_cache
*cachep
,
1023 struct kmem_cache_node
*n
)
1025 return (n
->free_objects
+ cachep
->num
- 1) / cachep
->num
;
1028 static void cpuup_canceled(long cpu
)
1030 struct kmem_cache
*cachep
;
1031 struct kmem_cache_node
*n
= NULL
;
1032 int node
= cpu_to_mem(cpu
);
1033 const struct cpumask
*mask
= cpumask_of_node(node
);
1035 list_for_each_entry(cachep
, &slab_caches
, list
) {
1036 struct array_cache
*nc
;
1037 struct array_cache
*shared
;
1038 struct alien_cache
**alien
;
1041 n
= get_node(cachep
, node
);
1045 spin_lock_irq(&n
->list_lock
);
1047 /* Free limit for this kmem_cache_node */
1048 n
->free_limit
-= cachep
->batchcount
;
1050 /* cpu is dead; no one can alloc from it. */
1051 nc
= per_cpu_ptr(cachep
->cpu_cache
, cpu
);
1053 free_block(cachep
, nc
->entry
, nc
->avail
, node
, &list
);
1057 if (!cpumask_empty(mask
)) {
1058 spin_unlock_irq(&n
->list_lock
);
1064 free_block(cachep
, shared
->entry
,
1065 shared
->avail
, node
, &list
);
1072 spin_unlock_irq(&n
->list_lock
);
1076 drain_alien_cache(cachep
, alien
);
1077 free_alien_cache(alien
);
1081 slabs_destroy(cachep
, &list
);
1084 * In the previous loop, all the objects were freed to
1085 * the respective cache's slabs, now we can go ahead and
1086 * shrink each nodelist to its limit.
1088 list_for_each_entry(cachep
, &slab_caches
, list
) {
1089 n
= get_node(cachep
, node
);
1092 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
1096 static int cpuup_prepare(long cpu
)
1098 struct kmem_cache
*cachep
;
1099 struct kmem_cache_node
*n
= NULL
;
1100 int node
= cpu_to_mem(cpu
);
1104 * We need to do this right in the beginning since
1105 * alloc_arraycache's are going to use this list.
1106 * kmalloc_node allows us to add the slab to the right
1107 * kmem_cache_node and not this cpu's kmem_cache_node
1109 err
= init_cache_node_node(node
);
1114 * Now we can go ahead with allocating the shared arrays and
1117 list_for_each_entry(cachep
, &slab_caches
, list
) {
1118 struct array_cache
*shared
= NULL
;
1119 struct alien_cache
**alien
= NULL
;
1121 if (cachep
->shared
) {
1122 shared
= alloc_arraycache(node
,
1123 cachep
->shared
* cachep
->batchcount
,
1124 0xbaadf00d, GFP_KERNEL
);
1128 if (use_alien_caches
) {
1129 alien
= alloc_alien_cache(node
, cachep
->limit
, GFP_KERNEL
);
1135 n
= get_node(cachep
, node
);
1138 spin_lock_irq(&n
->list_lock
);
1141 * We are serialised from CPU_DEAD or
1142 * CPU_UP_CANCELLED by the cpucontrol lock
1153 spin_unlock_irq(&n
->list_lock
);
1155 free_alien_cache(alien
);
1160 cpuup_canceled(cpu
);
1164 static int cpuup_callback(struct notifier_block
*nfb
,
1165 unsigned long action
, void *hcpu
)
1167 long cpu
= (long)hcpu
;
1171 case CPU_UP_PREPARE
:
1172 case CPU_UP_PREPARE_FROZEN
:
1173 mutex_lock(&slab_mutex
);
1174 err
= cpuup_prepare(cpu
);
1175 mutex_unlock(&slab_mutex
);
1178 case CPU_ONLINE_FROZEN
:
1179 start_cpu_timer(cpu
);
1181 #ifdef CONFIG_HOTPLUG_CPU
1182 case CPU_DOWN_PREPARE
:
1183 case CPU_DOWN_PREPARE_FROZEN
:
1185 * Shutdown cache reaper. Note that the slab_mutex is
1186 * held so that if cache_reap() is invoked it cannot do
1187 * anything expensive but will only modify reap_work
1188 * and reschedule the timer.
1190 cancel_delayed_work_sync(&per_cpu(slab_reap_work
, cpu
));
1191 /* Now the cache_reaper is guaranteed to be not running. */
1192 per_cpu(slab_reap_work
, cpu
).work
.func
= NULL
;
1194 case CPU_DOWN_FAILED
:
1195 case CPU_DOWN_FAILED_FROZEN
:
1196 start_cpu_timer(cpu
);
1199 case CPU_DEAD_FROZEN
:
1201 * Even if all the cpus of a node are down, we don't free the
1202 * kmem_cache_node of any cache. This to avoid a race between
1203 * cpu_down, and a kmalloc allocation from another cpu for
1204 * memory from the node of the cpu going down. The node
1205 * structure is usually allocated from kmem_cache_create() and
1206 * gets destroyed at kmem_cache_destroy().
1210 case CPU_UP_CANCELED
:
1211 case CPU_UP_CANCELED_FROZEN
:
1212 mutex_lock(&slab_mutex
);
1213 cpuup_canceled(cpu
);
1214 mutex_unlock(&slab_mutex
);
1217 return notifier_from_errno(err
);
1220 static struct notifier_block cpucache_notifier
= {
1221 &cpuup_callback
, NULL
, 0
1224 #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
1226 * Drains freelist for a node on each slab cache, used for memory hot-remove.
1227 * Returns -EBUSY if all objects cannot be drained so that the node is not
1230 * Must hold slab_mutex.
1232 static int __meminit
drain_cache_node_node(int node
)
1234 struct kmem_cache
*cachep
;
1237 list_for_each_entry(cachep
, &slab_caches
, list
) {
1238 struct kmem_cache_node
*n
;
1240 n
= get_node(cachep
, node
);
1244 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
1246 if (!list_empty(&n
->slabs_full
) ||
1247 !list_empty(&n
->slabs_partial
)) {
1255 static int __meminit
slab_memory_callback(struct notifier_block
*self
,
1256 unsigned long action
, void *arg
)
1258 struct memory_notify
*mnb
= arg
;
1262 nid
= mnb
->status_change_nid
;
1267 case MEM_GOING_ONLINE
:
1268 mutex_lock(&slab_mutex
);
1269 ret
= init_cache_node_node(nid
);
1270 mutex_unlock(&slab_mutex
);
1272 case MEM_GOING_OFFLINE
:
1273 mutex_lock(&slab_mutex
);
1274 ret
= drain_cache_node_node(nid
);
1275 mutex_unlock(&slab_mutex
);
1279 case MEM_CANCEL_ONLINE
:
1280 case MEM_CANCEL_OFFLINE
:
1284 return notifier_from_errno(ret
);
1286 #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
1289 * swap the static kmem_cache_node with kmalloced memory
1291 static void __init
init_list(struct kmem_cache
*cachep
, struct kmem_cache_node
*list
,
1294 struct kmem_cache_node
*ptr
;
1296 ptr
= kmalloc_node(sizeof(struct kmem_cache_node
), GFP_NOWAIT
, nodeid
);
1299 memcpy(ptr
, list
, sizeof(struct kmem_cache_node
));
1301 * Do not assume that spinlocks can be initialized via memcpy:
1303 spin_lock_init(&ptr
->list_lock
);
1305 MAKE_ALL_LISTS(cachep
, ptr
, nodeid
);
1306 cachep
->node
[nodeid
] = ptr
;
1310 * For setting up all the kmem_cache_node for cache whose buffer_size is same as
1311 * size of kmem_cache_node.
1313 static void __init
set_up_node(struct kmem_cache
*cachep
, int index
)
1317 for_each_online_node(node
) {
1318 cachep
->node
[node
] = &init_kmem_cache_node
[index
+ node
];
1319 cachep
->node
[node
]->next_reap
= jiffies
+
1321 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
1326 * Initialisation. Called after the page allocator have been initialised and
1327 * before smp_init().
1329 void __init
kmem_cache_init(void)
1333 BUILD_BUG_ON(sizeof(((struct page
*)NULL
)->lru
) <
1334 sizeof(struct rcu_head
));
1335 kmem_cache
= &kmem_cache_boot
;
1337 if (num_possible_nodes() == 1)
1338 use_alien_caches
= 0;
1340 for (i
= 0; i
< NUM_INIT_LISTS
; i
++)
1341 kmem_cache_node_init(&init_kmem_cache_node
[i
]);
1344 * Fragmentation resistance on low memory - only use bigger
1345 * page orders on machines with more than 32MB of memory if
1346 * not overridden on the command line.
1348 if (!slab_max_order_set
&& totalram_pages
> (32 << 20) >> PAGE_SHIFT
)
1349 slab_max_order
= SLAB_MAX_ORDER_HI
;
1351 /* Bootstrap is tricky, because several objects are allocated
1352 * from caches that do not exist yet:
1353 * 1) initialize the kmem_cache cache: it contains the struct
1354 * kmem_cache structures of all caches, except kmem_cache itself:
1355 * kmem_cache is statically allocated.
1356 * Initially an __init data area is used for the head array and the
1357 * kmem_cache_node structures, it's replaced with a kmalloc allocated
1358 * array at the end of the bootstrap.
1359 * 2) Create the first kmalloc cache.
1360 * The struct kmem_cache for the new cache is allocated normally.
1361 * An __init data area is used for the head array.
1362 * 3) Create the remaining kmalloc caches, with minimally sized
1364 * 4) Replace the __init data head arrays for kmem_cache and the first
1365 * kmalloc cache with kmalloc allocated arrays.
1366 * 5) Replace the __init data for kmem_cache_node for kmem_cache and
1367 * the other cache's with kmalloc allocated memory.
1368 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1371 /* 1) create the kmem_cache */
1374 * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
1376 create_boot_cache(kmem_cache
, "kmem_cache",
1377 offsetof(struct kmem_cache
, node
) +
1378 nr_node_ids
* sizeof(struct kmem_cache_node
*),
1379 SLAB_HWCACHE_ALIGN
);
1380 list_add(&kmem_cache
->list
, &slab_caches
);
1381 slab_state
= PARTIAL
;
1384 * Initialize the caches that provide memory for the kmem_cache_node
1385 * structures first. Without this, further allocations will bug.
1387 kmalloc_caches
[INDEX_NODE
] = create_kmalloc_cache("kmalloc-node",
1388 kmalloc_size(INDEX_NODE
), ARCH_KMALLOC_FLAGS
);
1389 slab_state
= PARTIAL_NODE
;
1390 setup_kmalloc_cache_index_table();
1392 slab_early_init
= 0;
1394 /* 5) Replace the bootstrap kmem_cache_node */
1398 for_each_online_node(nid
) {
1399 init_list(kmem_cache
, &init_kmem_cache_node
[CACHE_CACHE
+ nid
], nid
);
1401 init_list(kmalloc_caches
[INDEX_NODE
],
1402 &init_kmem_cache_node
[SIZE_NODE
+ nid
], nid
);
1406 create_kmalloc_caches(ARCH_KMALLOC_FLAGS
);
1409 void __init
kmem_cache_init_late(void)
1411 struct kmem_cache
*cachep
;
1415 /* 6) resize the head arrays to their final sizes */
1416 mutex_lock(&slab_mutex
);
1417 list_for_each_entry(cachep
, &slab_caches
, list
)
1418 if (enable_cpucache(cachep
, GFP_NOWAIT
))
1420 mutex_unlock(&slab_mutex
);
1426 * Register a cpu startup notifier callback that initializes
1427 * cpu_cache_get for all new cpus
1429 register_cpu_notifier(&cpucache_notifier
);
1433 * Register a memory hotplug callback that initializes and frees
1436 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
1440 * The reap timers are started later, with a module init call: That part
1441 * of the kernel is not yet operational.
1445 static int __init
cpucache_init(void)
1450 * Register the timers that return unneeded pages to the page allocator
1452 for_each_online_cpu(cpu
)
1453 start_cpu_timer(cpu
);
1459 __initcall(cpucache_init
);
1461 static noinline
void
1462 slab_out_of_memory(struct kmem_cache
*cachep
, gfp_t gfpflags
, int nodeid
)
1465 struct kmem_cache_node
*n
;
1467 unsigned long flags
;
1469 static DEFINE_RATELIMIT_STATE(slab_oom_rs
, DEFAULT_RATELIMIT_INTERVAL
,
1470 DEFAULT_RATELIMIT_BURST
);
1472 if ((gfpflags
& __GFP_NOWARN
) || !__ratelimit(&slab_oom_rs
))
1476 "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n",
1478 printk(KERN_WARNING
" cache: %s, object size: %d, order: %d\n",
1479 cachep
->name
, cachep
->size
, cachep
->gfporder
);
1481 for_each_kmem_cache_node(cachep
, node
, n
) {
1482 unsigned long active_objs
= 0, num_objs
= 0, free_objects
= 0;
1483 unsigned long active_slabs
= 0, num_slabs
= 0;
1485 spin_lock_irqsave(&n
->list_lock
, flags
);
1486 list_for_each_entry(page
, &n
->slabs_full
, lru
) {
1487 active_objs
+= cachep
->num
;
1490 list_for_each_entry(page
, &n
->slabs_partial
, lru
) {
1491 active_objs
+= page
->active
;
1494 list_for_each_entry(page
, &n
->slabs_free
, lru
)
1497 free_objects
+= n
->free_objects
;
1498 spin_unlock_irqrestore(&n
->list_lock
, flags
);
1500 num_slabs
+= active_slabs
;
1501 num_objs
= num_slabs
* cachep
->num
;
1503 " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",
1504 node
, active_slabs
, num_slabs
, active_objs
, num_objs
,
1511 * Interface to system's page allocator. No need to hold the
1512 * kmem_cache_node ->list_lock.
1514 * If we requested dmaable memory, we will get it. Even if we
1515 * did not request dmaable memory, we might get it, but that
1516 * would be relatively rare and ignorable.
1518 static struct page
*kmem_getpages(struct kmem_cache
*cachep
, gfp_t flags
,
1524 flags
|= cachep
->allocflags
;
1525 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1526 flags
|= __GFP_RECLAIMABLE
;
1528 page
= __alloc_pages_node(nodeid
, flags
| __GFP_NOTRACK
, cachep
->gfporder
);
1530 slab_out_of_memory(cachep
, flags
, nodeid
);
1534 if (memcg_charge_slab(page
, flags
, cachep
->gfporder
, cachep
)) {
1535 __free_pages(page
, cachep
->gfporder
);
1539 /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
1540 if (page_is_pfmemalloc(page
))
1541 pfmemalloc_active
= true;
1543 nr_pages
= (1 << cachep
->gfporder
);
1544 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1545 add_zone_page_state(page_zone(page
),
1546 NR_SLAB_RECLAIMABLE
, nr_pages
);
1548 add_zone_page_state(page_zone(page
),
1549 NR_SLAB_UNRECLAIMABLE
, nr_pages
);
1550 __SetPageSlab(page
);
1551 if (page_is_pfmemalloc(page
))
1552 SetPageSlabPfmemalloc(page
);
1554 if (kmemcheck_enabled
&& !(cachep
->flags
& SLAB_NOTRACK
)) {
1555 kmemcheck_alloc_shadow(page
, cachep
->gfporder
, flags
, nodeid
);
1558 kmemcheck_mark_uninitialized_pages(page
, nr_pages
);
1560 kmemcheck_mark_unallocated_pages(page
, nr_pages
);
1567 * Interface to system's page release.
1569 static void kmem_freepages(struct kmem_cache
*cachep
, struct page
*page
)
1571 const unsigned long nr_freed
= (1 << cachep
->gfporder
);
1573 kmemcheck_free_shadow(page
, cachep
->gfporder
);
1575 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1576 sub_zone_page_state(page_zone(page
),
1577 NR_SLAB_RECLAIMABLE
, nr_freed
);
1579 sub_zone_page_state(page_zone(page
),
1580 NR_SLAB_UNRECLAIMABLE
, nr_freed
);
1582 BUG_ON(!PageSlab(page
));
1583 __ClearPageSlabPfmemalloc(page
);
1584 __ClearPageSlab(page
);
1585 page_mapcount_reset(page
);
1586 page
->mapping
= NULL
;
1588 if (current
->reclaim_state
)
1589 current
->reclaim_state
->reclaimed_slab
+= nr_freed
;
1590 __free_kmem_pages(page
, cachep
->gfporder
);
1593 static void kmem_rcu_free(struct rcu_head
*head
)
1595 struct kmem_cache
*cachep
;
1598 page
= container_of(head
, struct page
, rcu_head
);
1599 cachep
= page
->slab_cache
;
1601 kmem_freepages(cachep
, page
);
1605 static bool is_debug_pagealloc_cache(struct kmem_cache
*cachep
)
1607 if (debug_pagealloc_enabled() && OFF_SLAB(cachep
) &&
1608 (cachep
->size
% PAGE_SIZE
) == 0)
1614 #ifdef CONFIG_DEBUG_PAGEALLOC
1615 static void store_stackinfo(struct kmem_cache
*cachep
, unsigned long *addr
,
1616 unsigned long caller
)
1618 int size
= cachep
->object_size
;
1620 addr
= (unsigned long *)&((char *)addr
)[obj_offset(cachep
)];
1622 if (size
< 5 * sizeof(unsigned long))
1625 *addr
++ = 0x12345678;
1627 *addr
++ = smp_processor_id();
1628 size
-= 3 * sizeof(unsigned long);
1630 unsigned long *sptr
= &caller
;
1631 unsigned long svalue
;
1633 while (!kstack_end(sptr
)) {
1635 if (kernel_text_address(svalue
)) {
1637 size
-= sizeof(unsigned long);
1638 if (size
<= sizeof(unsigned long))
1644 *addr
++ = 0x87654321;
1647 static void slab_kernel_map(struct kmem_cache
*cachep
, void *objp
,
1648 int map
, unsigned long caller
)
1650 if (!is_debug_pagealloc_cache(cachep
))
1654 store_stackinfo(cachep
, objp
, caller
);
1656 kernel_map_pages(virt_to_page(objp
), cachep
->size
/ PAGE_SIZE
, map
);
1660 static inline void slab_kernel_map(struct kmem_cache
*cachep
, void *objp
,
1661 int map
, unsigned long caller
) {}
1665 static void poison_obj(struct kmem_cache
*cachep
, void *addr
, unsigned char val
)
1667 int size
= cachep
->object_size
;
1668 addr
= &((char *)addr
)[obj_offset(cachep
)];
1670 memset(addr
, val
, size
);
1671 *(unsigned char *)(addr
+ size
- 1) = POISON_END
;
1674 static void dump_line(char *data
, int offset
, int limit
)
1677 unsigned char error
= 0;
1680 printk(KERN_ERR
"%03x: ", offset
);
1681 for (i
= 0; i
< limit
; i
++) {
1682 if (data
[offset
+ i
] != POISON_FREE
) {
1683 error
= data
[offset
+ i
];
1687 print_hex_dump(KERN_CONT
, "", 0, 16, 1,
1688 &data
[offset
], limit
, 1);
1690 if (bad_count
== 1) {
1691 error
^= POISON_FREE
;
1692 if (!(error
& (error
- 1))) {
1693 printk(KERN_ERR
"Single bit error detected. Probably "
1696 printk(KERN_ERR
"Run memtest86+ or a similar memory "
1699 printk(KERN_ERR
"Run a memory test tool.\n");
1708 static void print_objinfo(struct kmem_cache
*cachep
, void *objp
, int lines
)
1713 if (cachep
->flags
& SLAB_RED_ZONE
) {
1714 printk(KERN_ERR
"Redzone: 0x%llx/0x%llx.\n",
1715 *dbg_redzone1(cachep
, objp
),
1716 *dbg_redzone2(cachep
, objp
));
1719 if (cachep
->flags
& SLAB_STORE_USER
) {
1720 printk(KERN_ERR
"Last user: [<%p>](%pSR)\n",
1721 *dbg_userword(cachep
, objp
),
1722 *dbg_userword(cachep
, objp
));
1724 realobj
= (char *)objp
+ obj_offset(cachep
);
1725 size
= cachep
->object_size
;
1726 for (i
= 0; i
< size
&& lines
; i
+= 16, lines
--) {
1729 if (i
+ limit
> size
)
1731 dump_line(realobj
, i
, limit
);
1735 static void check_poison_obj(struct kmem_cache
*cachep
, void *objp
)
1741 if (is_debug_pagealloc_cache(cachep
))
1744 realobj
= (char *)objp
+ obj_offset(cachep
);
1745 size
= cachep
->object_size
;
1747 for (i
= 0; i
< size
; i
++) {
1748 char exp
= POISON_FREE
;
1751 if (realobj
[i
] != exp
) {
1757 "Slab corruption (%s): %s start=%p, len=%d\n",
1758 print_tainted(), cachep
->name
, realobj
, size
);
1759 print_objinfo(cachep
, objp
, 0);
1761 /* Hexdump the affected line */
1764 if (i
+ limit
> size
)
1766 dump_line(realobj
, i
, limit
);
1769 /* Limit to 5 lines */
1775 /* Print some data about the neighboring objects, if they
1778 struct page
*page
= virt_to_head_page(objp
);
1781 objnr
= obj_to_index(cachep
, page
, objp
);
1783 objp
= index_to_obj(cachep
, page
, objnr
- 1);
1784 realobj
= (char *)objp
+ obj_offset(cachep
);
1785 printk(KERN_ERR
"Prev obj: start=%p, len=%d\n",
1787 print_objinfo(cachep
, objp
, 2);
1789 if (objnr
+ 1 < cachep
->num
) {
1790 objp
= index_to_obj(cachep
, page
, objnr
+ 1);
1791 realobj
= (char *)objp
+ obj_offset(cachep
);
1792 printk(KERN_ERR
"Next obj: start=%p, len=%d\n",
1794 print_objinfo(cachep
, objp
, 2);
1801 static void slab_destroy_debugcheck(struct kmem_cache
*cachep
,
1805 for (i
= 0; i
< cachep
->num
; i
++) {
1806 void *objp
= index_to_obj(cachep
, page
, i
);
1808 if (cachep
->flags
& SLAB_POISON
) {
1809 check_poison_obj(cachep
, objp
);
1810 slab_kernel_map(cachep
, objp
, 1, 0);
1812 if (cachep
->flags
& SLAB_RED_ZONE
) {
1813 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
1814 slab_error(cachep
, "start of a freed object "
1816 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
1817 slab_error(cachep
, "end of a freed object "
1823 static void slab_destroy_debugcheck(struct kmem_cache
*cachep
,
1830 * slab_destroy - destroy and release all objects in a slab
1831 * @cachep: cache pointer being destroyed
1832 * @page: page pointer being destroyed
1834 * Destroy all the objs in a slab page, and release the mem back to the system.
1835 * Before calling the slab page must have been unlinked from the cache. The
1836 * kmem_cache_node ->list_lock is not held/needed.
1838 static void slab_destroy(struct kmem_cache
*cachep
, struct page
*page
)
1842 freelist
= page
->freelist
;
1843 slab_destroy_debugcheck(cachep
, page
);
1844 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
))
1845 call_rcu(&page
->rcu_head
, kmem_rcu_free
);
1847 kmem_freepages(cachep
, page
);
1850 * From now on, we don't use freelist
1851 * although actual page can be freed in rcu context
1853 if (OFF_SLAB(cachep
))
1854 kmem_cache_free(cachep
->freelist_cache
, freelist
);
1857 static void slabs_destroy(struct kmem_cache
*cachep
, struct list_head
*list
)
1859 struct page
*page
, *n
;
1861 list_for_each_entry_safe(page
, n
, list
, lru
) {
1862 list_del(&page
->lru
);
1863 slab_destroy(cachep
, page
);
1868 * calculate_slab_order - calculate size (page order) of slabs
1869 * @cachep: pointer to the cache that is being created
1870 * @size: size of objects to be created in this cache.
1871 * @flags: slab allocation flags
1873 * Also calculates the number of objects per slab.
1875 * This could be made much more intelligent. For now, try to avoid using
1876 * high order pages for slabs. When the gfp() functions are more friendly
1877 * towards high-order requests, this should be changed.
1879 static size_t calculate_slab_order(struct kmem_cache
*cachep
,
1880 size_t size
, unsigned long flags
)
1882 unsigned long offslab_limit
;
1883 size_t left_over
= 0;
1886 for (gfporder
= 0; gfporder
<= KMALLOC_MAX_ORDER
; gfporder
++) {
1890 cache_estimate(gfporder
, size
, flags
, &remainder
, &num
);
1894 /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
1895 if (num
> SLAB_OBJ_MAX_NUM
)
1898 if (flags
& CFLGS_OFF_SLAB
) {
1900 * Max number of objs-per-slab for caches which
1901 * use off-slab slabs. Needed to avoid a possible
1902 * looping condition in cache_grow().
1904 offslab_limit
= size
;
1905 offslab_limit
/= sizeof(freelist_idx_t
);
1907 if (num
> offslab_limit
)
1911 /* Found something acceptable - save it away */
1913 cachep
->gfporder
= gfporder
;
1914 left_over
= remainder
;
1917 * A VFS-reclaimable slab tends to have most allocations
1918 * as GFP_NOFS and we really don't want to have to be allocating
1919 * higher-order pages when we are unable to shrink dcache.
1921 if (flags
& SLAB_RECLAIM_ACCOUNT
)
1925 * Large number of objects is good, but very large slabs are
1926 * currently bad for the gfp()s.
1928 if (gfporder
>= slab_max_order
)
1932 * Acceptable internal fragmentation?
1934 if (left_over
* 8 <= (PAGE_SIZE
<< gfporder
))
1940 static struct array_cache __percpu
*alloc_kmem_cache_cpus(
1941 struct kmem_cache
*cachep
, int entries
, int batchcount
)
1945 struct array_cache __percpu
*cpu_cache
;
1947 size
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
1948 cpu_cache
= __alloc_percpu(size
, sizeof(void *));
1953 for_each_possible_cpu(cpu
) {
1954 init_arraycache(per_cpu_ptr(cpu_cache
, cpu
),
1955 entries
, batchcount
);
1961 static int __init_refok
setup_cpu_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
1963 if (slab_state
>= FULL
)
1964 return enable_cpucache(cachep
, gfp
);
1966 cachep
->cpu_cache
= alloc_kmem_cache_cpus(cachep
, 1, 1);
1967 if (!cachep
->cpu_cache
)
1970 if (slab_state
== DOWN
) {
1971 /* Creation of first cache (kmem_cache). */
1972 set_up_node(kmem_cache
, CACHE_CACHE
);
1973 } else if (slab_state
== PARTIAL
) {
1974 /* For kmem_cache_node */
1975 set_up_node(cachep
, SIZE_NODE
);
1979 for_each_online_node(node
) {
1980 cachep
->node
[node
] = kmalloc_node(
1981 sizeof(struct kmem_cache_node
), gfp
, node
);
1982 BUG_ON(!cachep
->node
[node
]);
1983 kmem_cache_node_init(cachep
->node
[node
]);
1987 cachep
->node
[numa_mem_id()]->next_reap
=
1988 jiffies
+ REAPTIMEOUT_NODE
+
1989 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
1991 cpu_cache_get(cachep
)->avail
= 0;
1992 cpu_cache_get(cachep
)->limit
= BOOT_CPUCACHE_ENTRIES
;
1993 cpu_cache_get(cachep
)->batchcount
= 1;
1994 cpu_cache_get(cachep
)->touched
= 0;
1995 cachep
->batchcount
= 1;
1996 cachep
->limit
= BOOT_CPUCACHE_ENTRIES
;
2000 unsigned long kmem_cache_flags(unsigned long object_size
,
2001 unsigned long flags
, const char *name
,
2002 void (*ctor
)(void *))
2008 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
2009 unsigned long flags
, void (*ctor
)(void *))
2011 struct kmem_cache
*cachep
;
2013 cachep
= find_mergeable(size
, align
, flags
, name
, ctor
);
2018 * Adjust the object sizes so that we clear
2019 * the complete object on kzalloc.
2021 cachep
->object_size
= max_t(int, cachep
->object_size
, size
);
2026 static bool set_off_slab_cache(struct kmem_cache
*cachep
,
2027 size_t size
, unsigned long flags
)
2034 * Determine if the slab management is 'on' or 'off' slab.
2035 * (bootstrapping cannot cope with offslab caches so don't do
2036 * it too early on. Always use on-slab management when
2037 * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak)
2039 if (size
< OFF_SLAB_MIN_SIZE
)
2042 if (slab_early_init
)
2045 if (flags
& SLAB_NOLEAKTRACE
)
2049 * Size is large, assume best to place the slab management obj
2050 * off-slab (should allow better packing of objs).
2052 left
= calculate_slab_order(cachep
, size
, flags
| CFLGS_OFF_SLAB
);
2057 * If the slab has been placed off-slab, and we have enough space then
2058 * move it on-slab. This is at the expense of any extra colouring.
2060 if (left
>= cachep
->num
* sizeof(freelist_idx_t
))
2063 cachep
->colour
= left
/ cachep
->colour_off
;
2068 static bool set_on_slab_cache(struct kmem_cache
*cachep
,
2069 size_t size
, unsigned long flags
)
2075 left
= calculate_slab_order(cachep
, size
, flags
);
2079 cachep
->colour
= left
/ cachep
->colour_off
;
2085 * __kmem_cache_create - Create a cache.
2086 * @cachep: cache management descriptor
2087 * @flags: SLAB flags
2089 * Returns a ptr to the cache on success, NULL on failure.
2090 * Cannot be called within a int, but can be interrupted.
2091 * The @ctor is run when new pages are allocated by the cache.
2095 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2096 * to catch references to uninitialised memory.
2098 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2099 * for buffer overruns.
2101 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2102 * cacheline. This can be beneficial if you're counting cycles as closely
2106 __kmem_cache_create (struct kmem_cache
*cachep
, unsigned long flags
)
2108 size_t ralign
= BYTES_PER_WORD
;
2111 size_t size
= cachep
->size
;
2116 * Enable redzoning and last user accounting, except for caches with
2117 * large objects, if the increased size would increase the object size
2118 * above the next power of two: caches with object sizes just above a
2119 * power of two have a significant amount of internal fragmentation.
2121 if (size
< 4096 || fls(size
- 1) == fls(size
-1 + REDZONE_ALIGN
+
2122 2 * sizeof(unsigned long long)))
2123 flags
|= SLAB_RED_ZONE
| SLAB_STORE_USER
;
2124 if (!(flags
& SLAB_DESTROY_BY_RCU
))
2125 flags
|= SLAB_POISON
;
2130 * Check that size is in terms of words. This is needed to avoid
2131 * unaligned accesses for some archs when redzoning is used, and makes
2132 * sure any on-slab bufctl's are also correctly aligned.
2134 if (size
& (BYTES_PER_WORD
- 1)) {
2135 size
+= (BYTES_PER_WORD
- 1);
2136 size
&= ~(BYTES_PER_WORD
- 1);
2139 if (flags
& SLAB_RED_ZONE
) {
2140 ralign
= REDZONE_ALIGN
;
2141 /* If redzoning, ensure that the second redzone is suitably
2142 * aligned, by adjusting the object size accordingly. */
2143 size
+= REDZONE_ALIGN
- 1;
2144 size
&= ~(REDZONE_ALIGN
- 1);
2147 /* 3) caller mandated alignment */
2148 if (ralign
< cachep
->align
) {
2149 ralign
= cachep
->align
;
2151 /* disable debug if necessary */
2152 if (ralign
> __alignof__(unsigned long long))
2153 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2157 cachep
->align
= ralign
;
2158 cachep
->colour_off
= cache_line_size();
2159 /* Offset must be a multiple of the alignment. */
2160 if (cachep
->colour_off
< cachep
->align
)
2161 cachep
->colour_off
= cachep
->align
;
2163 if (slab_is_available())
2171 * Both debugging options require word-alignment which is calculated
2174 if (flags
& SLAB_RED_ZONE
) {
2175 /* add space for red zone words */
2176 cachep
->obj_offset
+= sizeof(unsigned long long);
2177 size
+= 2 * sizeof(unsigned long long);
2179 if (flags
& SLAB_STORE_USER
) {
2180 /* user store requires one word storage behind the end of
2181 * the real object. But if the second red zone needs to be
2182 * aligned to 64 bits, we must allow that much space.
2184 if (flags
& SLAB_RED_ZONE
)
2185 size
+= REDZONE_ALIGN
;
2187 size
+= BYTES_PER_WORD
;
2191 size
= ALIGN(size
, cachep
->align
);
2193 * We should restrict the number of objects in a slab to implement
2194 * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
2196 if (FREELIST_BYTE_INDEX
&& size
< SLAB_OBJ_MIN_SIZE
)
2197 size
= ALIGN(SLAB_OBJ_MIN_SIZE
, cachep
->align
);
2201 * To activate debug pagealloc, off-slab management is necessary
2202 * requirement. In early phase of initialization, small sized slab
2203 * doesn't get initialized so it would not be possible. So, we need
2204 * to check size >= 256. It guarantees that all necessary small
2205 * sized slab is initialized in current slab initialization sequence.
2207 if (debug_pagealloc_enabled() && (flags
& SLAB_POISON
) &&
2208 !slab_early_init
&& size
>= kmalloc_size(INDEX_NODE
) &&
2209 size
>= 256 && cachep
->object_size
> cache_line_size() &&
2211 cachep
->obj_offset
+= PAGE_SIZE
- size
;
2216 if (set_off_slab_cache(cachep
, size
, flags
)) {
2217 flags
|= CFLGS_OFF_SLAB
;
2221 if (set_on_slab_cache(cachep
, size
, flags
))
2227 cachep
->freelist_size
= cachep
->num
* sizeof(freelist_idx_t
);
2228 cachep
->flags
= flags
;
2229 cachep
->allocflags
= __GFP_COMP
;
2230 if (CONFIG_ZONE_DMA_FLAG
&& (flags
& SLAB_CACHE_DMA
))
2231 cachep
->allocflags
|= GFP_DMA
;
2232 cachep
->size
= size
;
2233 cachep
->reciprocal_buffer_size
= reciprocal_value(size
);
2237 * If we're going to use the generic kernel_map_pages()
2238 * poisoning, then it's going to smash the contents of
2239 * the redzone and userword anyhow, so switch them off.
2241 if (IS_ENABLED(CONFIG_PAGE_POISONING
) &&
2242 (cachep
->flags
& SLAB_POISON
) &&
2243 is_debug_pagealloc_cache(cachep
))
2244 cachep
->flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2247 if (OFF_SLAB(cachep
)) {
2248 cachep
->freelist_cache
=
2249 kmalloc_slab(cachep
->freelist_size
, 0u);
2251 * This is a possibility for one of the kmalloc_{dma,}_caches.
2252 * But since we go off slab only for object size greater than
2253 * OFF_SLAB_MIN_SIZE, and kmalloc_{dma,}_caches get created
2254 * in ascending order,this should not happen at all.
2255 * But leave a BUG_ON for some lucky dude.
2257 BUG_ON(ZERO_OR_NULL_PTR(cachep
->freelist_cache
));
2260 err
= setup_cpu_cache(cachep
, gfp
);
2262 __kmem_cache_release(cachep
);
2270 static void check_irq_off(void)
2272 BUG_ON(!irqs_disabled());
2275 static void check_irq_on(void)
2277 BUG_ON(irqs_disabled());
2280 static void check_spinlock_acquired(struct kmem_cache
*cachep
)
2284 assert_spin_locked(&get_node(cachep
, numa_mem_id())->list_lock
);
2288 static void check_spinlock_acquired_node(struct kmem_cache
*cachep
, int node
)
2292 assert_spin_locked(&get_node(cachep
, node
)->list_lock
);
2297 #define check_irq_off() do { } while(0)
2298 #define check_irq_on() do { } while(0)
2299 #define check_spinlock_acquired(x) do { } while(0)
2300 #define check_spinlock_acquired_node(x, y) do { } while(0)
2303 static void drain_array(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
,
2304 struct array_cache
*ac
,
2305 int force
, int node
);
2307 static void do_drain(void *arg
)
2309 struct kmem_cache
*cachep
= arg
;
2310 struct array_cache
*ac
;
2311 int node
= numa_mem_id();
2312 struct kmem_cache_node
*n
;
2316 ac
= cpu_cache_get(cachep
);
2317 n
= get_node(cachep
, node
);
2318 spin_lock(&n
->list_lock
);
2319 free_block(cachep
, ac
->entry
, ac
->avail
, node
, &list
);
2320 spin_unlock(&n
->list_lock
);
2321 slabs_destroy(cachep
, &list
);
2325 static void drain_cpu_caches(struct kmem_cache
*cachep
)
2327 struct kmem_cache_node
*n
;
2330 on_each_cpu(do_drain
, cachep
, 1);
2332 for_each_kmem_cache_node(cachep
, node
, n
)
2334 drain_alien_cache(cachep
, n
->alien
);
2336 for_each_kmem_cache_node(cachep
, node
, n
)
2337 drain_array(cachep
, n
, n
->shared
, 1, node
);
2341 * Remove slabs from the list of free slabs.
2342 * Specify the number of slabs to drain in tofree.
2344 * Returns the actual number of slabs released.
2346 static int drain_freelist(struct kmem_cache
*cache
,
2347 struct kmem_cache_node
*n
, int tofree
)
2349 struct list_head
*p
;
2354 while (nr_freed
< tofree
&& !list_empty(&n
->slabs_free
)) {
2356 spin_lock_irq(&n
->list_lock
);
2357 p
= n
->slabs_free
.prev
;
2358 if (p
== &n
->slabs_free
) {
2359 spin_unlock_irq(&n
->list_lock
);
2363 page
= list_entry(p
, struct page
, lru
);
2364 list_del(&page
->lru
);
2366 * Safe to drop the lock. The slab is no longer linked
2369 n
->free_objects
-= cache
->num
;
2370 spin_unlock_irq(&n
->list_lock
);
2371 slab_destroy(cache
, page
);
2378 int __kmem_cache_shrink(struct kmem_cache
*cachep
, bool deactivate
)
2382 struct kmem_cache_node
*n
;
2384 drain_cpu_caches(cachep
);
2387 for_each_kmem_cache_node(cachep
, node
, n
) {
2388 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
2390 ret
+= !list_empty(&n
->slabs_full
) ||
2391 !list_empty(&n
->slabs_partial
);
2393 return (ret
? 1 : 0);
2396 int __kmem_cache_shutdown(struct kmem_cache
*cachep
)
2398 return __kmem_cache_shrink(cachep
, false);
2401 void __kmem_cache_release(struct kmem_cache
*cachep
)
2404 struct kmem_cache_node
*n
;
2406 free_percpu(cachep
->cpu_cache
);
2408 /* NUMA: free the node structures */
2409 for_each_kmem_cache_node(cachep
, i
, n
) {
2411 free_alien_cache(n
->alien
);
2413 cachep
->node
[i
] = NULL
;
2418 * Get the memory for a slab management obj.
2420 * For a slab cache when the slab descriptor is off-slab, the
2421 * slab descriptor can't come from the same cache which is being created,
2422 * Because if it is the case, that means we defer the creation of
2423 * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
2424 * And we eventually call down to __kmem_cache_create(), which
2425 * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
2426 * This is a "chicken-and-egg" problem.
2428 * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
2429 * which are all initialized during kmem_cache_init().
2431 static void *alloc_slabmgmt(struct kmem_cache
*cachep
,
2432 struct page
*page
, int colour_off
,
2433 gfp_t local_flags
, int nodeid
)
2436 void *addr
= page_address(page
);
2438 page
->s_mem
= addr
+ colour_off
;
2441 if (OFF_SLAB(cachep
)) {
2442 /* Slab management obj is off-slab. */
2443 freelist
= kmem_cache_alloc_node(cachep
->freelist_cache
,
2444 local_flags
, nodeid
);
2448 /* We will use last bytes at the slab for freelist */
2449 freelist
= addr
+ (PAGE_SIZE
<< cachep
->gfporder
) -
2450 cachep
->freelist_size
;
2456 static inline freelist_idx_t
get_free_obj(struct page
*page
, unsigned int idx
)
2458 return ((freelist_idx_t
*)page
->freelist
)[idx
];
2461 static inline void set_free_obj(struct page
*page
,
2462 unsigned int idx
, freelist_idx_t val
)
2464 ((freelist_idx_t
*)(page
->freelist
))[idx
] = val
;
2467 static void cache_init_objs(struct kmem_cache
*cachep
,
2472 for (i
= 0; i
< cachep
->num
; i
++) {
2473 void *objp
= index_to_obj(cachep
, page
, i
);
2475 if (cachep
->flags
& SLAB_STORE_USER
)
2476 *dbg_userword(cachep
, objp
) = NULL
;
2478 if (cachep
->flags
& SLAB_RED_ZONE
) {
2479 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2480 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2483 * Constructors are not allowed to allocate memory from the same
2484 * cache which they are a constructor for. Otherwise, deadlock.
2485 * They must also be threaded.
2487 if (cachep
->ctor
&& !(cachep
->flags
& SLAB_POISON
))
2488 cachep
->ctor(objp
+ obj_offset(cachep
));
2490 if (cachep
->flags
& SLAB_RED_ZONE
) {
2491 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
2492 slab_error(cachep
, "constructor overwrote the"
2493 " end of an object");
2494 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
2495 slab_error(cachep
, "constructor overwrote the"
2496 " start of an object");
2498 /* need to poison the objs? */
2499 if (cachep
->flags
& SLAB_POISON
) {
2500 poison_obj(cachep
, objp
, POISON_FREE
);
2501 slab_kernel_map(cachep
, objp
, 0, 0);
2507 set_free_obj(page
, i
, i
);
2511 static void kmem_flagcheck(struct kmem_cache
*cachep
, gfp_t flags
)
2513 if (CONFIG_ZONE_DMA_FLAG
) {
2514 if (flags
& GFP_DMA
)
2515 BUG_ON(!(cachep
->allocflags
& GFP_DMA
));
2517 BUG_ON(cachep
->allocflags
& GFP_DMA
);
2521 static void *slab_get_obj(struct kmem_cache
*cachep
, struct page
*page
)
2525 objp
= index_to_obj(cachep
, page
, get_free_obj(page
, page
->active
));
2529 if (cachep
->flags
& SLAB_STORE_USER
)
2530 set_store_user_dirty(cachep
);
2536 static void slab_put_obj(struct kmem_cache
*cachep
,
2537 struct page
*page
, void *objp
)
2539 unsigned int objnr
= obj_to_index(cachep
, page
, objp
);
2543 /* Verify double free bug */
2544 for (i
= page
->active
; i
< cachep
->num
; i
++) {
2545 if (get_free_obj(page
, i
) == objnr
) {
2546 printk(KERN_ERR
"slab: double free detected in cache "
2547 "'%s', objp %p\n", cachep
->name
, objp
);
2553 set_free_obj(page
, page
->active
, objnr
);
2557 * Map pages beginning at addr to the given cache and slab. This is required
2558 * for the slab allocator to be able to lookup the cache and slab of a
2559 * virtual address for kfree, ksize, and slab debugging.
2561 static void slab_map_pages(struct kmem_cache
*cache
, struct page
*page
,
2564 page
->slab_cache
= cache
;
2565 page
->freelist
= freelist
;
2569 * Grow (by 1) the number of slabs within a cache. This is called by
2570 * kmem_cache_alloc() when there are no active objs left in a cache.
2572 static int cache_grow(struct kmem_cache
*cachep
,
2573 gfp_t flags
, int nodeid
, struct page
*page
)
2578 struct kmem_cache_node
*n
;
2581 * Be lazy and only check for valid flags here, keeping it out of the
2582 * critical path in kmem_cache_alloc().
2584 if (unlikely(flags
& GFP_SLAB_BUG_MASK
)) {
2585 pr_emerg("gfp: %u\n", flags
& GFP_SLAB_BUG_MASK
);
2588 local_flags
= flags
& (GFP_CONSTRAINT_MASK
|GFP_RECLAIM_MASK
);
2590 /* Take the node list lock to change the colour_next on this node */
2592 n
= get_node(cachep
, nodeid
);
2593 spin_lock(&n
->list_lock
);
2595 /* Get colour for the slab, and cal the next value. */
2596 offset
= n
->colour_next
;
2598 if (n
->colour_next
>= cachep
->colour
)
2600 spin_unlock(&n
->list_lock
);
2602 offset
*= cachep
->colour_off
;
2604 if (gfpflags_allow_blocking(local_flags
))
2608 * The test for missing atomic flag is performed here, rather than
2609 * the more obvious place, simply to reduce the critical path length
2610 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2611 * will eventually be caught here (where it matters).
2613 kmem_flagcheck(cachep
, flags
);
2616 * Get mem for the objs. Attempt to allocate a physical page from
2620 page
= kmem_getpages(cachep
, local_flags
, nodeid
);
2624 /* Get slab management. */
2625 freelist
= alloc_slabmgmt(cachep
, page
, offset
,
2626 local_flags
& ~GFP_CONSTRAINT_MASK
, nodeid
);
2630 slab_map_pages(cachep
, page
, freelist
);
2632 cache_init_objs(cachep
, page
);
2634 if (gfpflags_allow_blocking(local_flags
))
2635 local_irq_disable();
2637 spin_lock(&n
->list_lock
);
2639 /* Make slab active. */
2640 list_add_tail(&page
->lru
, &(n
->slabs_free
));
2641 STATS_INC_GROWN(cachep
);
2642 n
->free_objects
+= cachep
->num
;
2643 spin_unlock(&n
->list_lock
);
2646 kmem_freepages(cachep
, page
);
2648 if (gfpflags_allow_blocking(local_flags
))
2649 local_irq_disable();
2656 * Perform extra freeing checks:
2657 * - detect bad pointers.
2658 * - POISON/RED_ZONE checking
2660 static void kfree_debugcheck(const void *objp
)
2662 if (!virt_addr_valid(objp
)) {
2663 printk(KERN_ERR
"kfree_debugcheck: out of range ptr %lxh.\n",
2664 (unsigned long)objp
);
2669 static inline void verify_redzone_free(struct kmem_cache
*cache
, void *obj
)
2671 unsigned long long redzone1
, redzone2
;
2673 redzone1
= *dbg_redzone1(cache
, obj
);
2674 redzone2
= *dbg_redzone2(cache
, obj
);
2679 if (redzone1
== RED_ACTIVE
&& redzone2
== RED_ACTIVE
)
2682 if (redzone1
== RED_INACTIVE
&& redzone2
== RED_INACTIVE
)
2683 slab_error(cache
, "double free detected");
2685 slab_error(cache
, "memory outside object was overwritten");
2687 printk(KERN_ERR
"%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
2688 obj
, redzone1
, redzone2
);
2691 static void *cache_free_debugcheck(struct kmem_cache
*cachep
, void *objp
,
2692 unsigned long caller
)
2697 BUG_ON(virt_to_cache(objp
) != cachep
);
2699 objp
-= obj_offset(cachep
);
2700 kfree_debugcheck(objp
);
2701 page
= virt_to_head_page(objp
);
2703 if (cachep
->flags
& SLAB_RED_ZONE
) {
2704 verify_redzone_free(cachep
, objp
);
2705 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2706 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2708 if (cachep
->flags
& SLAB_STORE_USER
) {
2709 set_store_user_dirty(cachep
);
2710 *dbg_userword(cachep
, objp
) = (void *)caller
;
2713 objnr
= obj_to_index(cachep
, page
, objp
);
2715 BUG_ON(objnr
>= cachep
->num
);
2716 BUG_ON(objp
!= index_to_obj(cachep
, page
, objnr
));
2718 if (cachep
->flags
& SLAB_POISON
) {
2719 poison_obj(cachep
, objp
, POISON_FREE
);
2720 slab_kernel_map(cachep
, objp
, 0, caller
);
2726 #define kfree_debugcheck(x) do { } while(0)
2727 #define cache_free_debugcheck(x,objp,z) (objp)
2730 static struct page
*get_first_slab(struct kmem_cache_node
*n
)
2734 page
= list_first_entry_or_null(&n
->slabs_partial
,
2737 n
->free_touched
= 1;
2738 page
= list_first_entry_or_null(&n
->slabs_free
,
2745 static void *cache_alloc_refill(struct kmem_cache
*cachep
, gfp_t flags
,
2749 struct kmem_cache_node
*n
;
2750 struct array_cache
*ac
;
2754 node
= numa_mem_id();
2755 if (unlikely(force_refill
))
2758 ac
= cpu_cache_get(cachep
);
2759 batchcount
= ac
->batchcount
;
2760 if (!ac
->touched
&& batchcount
> BATCHREFILL_LIMIT
) {
2762 * If there was little recent activity on this cache, then
2763 * perform only a partial refill. Otherwise we could generate
2766 batchcount
= BATCHREFILL_LIMIT
;
2768 n
= get_node(cachep
, node
);
2770 BUG_ON(ac
->avail
> 0 || !n
);
2771 spin_lock(&n
->list_lock
);
2773 /* See if we can refill from the shared array */
2774 if (n
->shared
&& transfer_objects(ac
, n
->shared
, batchcount
)) {
2775 n
->shared
->touched
= 1;
2779 while (batchcount
> 0) {
2781 /* Get slab alloc is to come from. */
2782 page
= get_first_slab(n
);
2786 check_spinlock_acquired(cachep
);
2789 * The slab was either on partial or free list so
2790 * there must be at least one object available for
2793 BUG_ON(page
->active
>= cachep
->num
);
2795 while (page
->active
< cachep
->num
&& batchcount
--) {
2796 STATS_INC_ALLOCED(cachep
);
2797 STATS_INC_ACTIVE(cachep
);
2798 STATS_SET_HIGH(cachep
);
2800 ac_put_obj(cachep
, ac
, slab_get_obj(cachep
, page
));
2803 /* move slabp to correct slabp list: */
2804 list_del(&page
->lru
);
2805 if (page
->active
== cachep
->num
)
2806 list_add(&page
->lru
, &n
->slabs_full
);
2808 list_add(&page
->lru
, &n
->slabs_partial
);
2812 n
->free_objects
-= ac
->avail
;
2814 spin_unlock(&n
->list_lock
);
2816 if (unlikely(!ac
->avail
)) {
2819 x
= cache_grow(cachep
, gfp_exact_node(flags
), node
, NULL
);
2821 /* cache_grow can reenable interrupts, then ac could change. */
2822 ac
= cpu_cache_get(cachep
);
2823 node
= numa_mem_id();
2825 /* no objects in sight? abort */
2826 if (!x
&& (ac
->avail
== 0 || force_refill
))
2829 if (!ac
->avail
) /* objects refilled by interrupt? */
2834 return ac_get_obj(cachep
, ac
, flags
, force_refill
);
2837 static inline void cache_alloc_debugcheck_before(struct kmem_cache
*cachep
,
2840 might_sleep_if(gfpflags_allow_blocking(flags
));
2842 kmem_flagcheck(cachep
, flags
);
2847 static void *cache_alloc_debugcheck_after(struct kmem_cache
*cachep
,
2848 gfp_t flags
, void *objp
, unsigned long caller
)
2852 if (cachep
->flags
& SLAB_POISON
) {
2853 check_poison_obj(cachep
, objp
);
2854 slab_kernel_map(cachep
, objp
, 1, 0);
2855 poison_obj(cachep
, objp
, POISON_INUSE
);
2857 if (cachep
->flags
& SLAB_STORE_USER
)
2858 *dbg_userword(cachep
, objp
) = (void *)caller
;
2860 if (cachep
->flags
& SLAB_RED_ZONE
) {
2861 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
||
2862 *dbg_redzone2(cachep
, objp
) != RED_INACTIVE
) {
2863 slab_error(cachep
, "double free, or memory outside"
2864 " object was overwritten");
2866 "%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
2867 objp
, *dbg_redzone1(cachep
, objp
),
2868 *dbg_redzone2(cachep
, objp
));
2870 *dbg_redzone1(cachep
, objp
) = RED_ACTIVE
;
2871 *dbg_redzone2(cachep
, objp
) = RED_ACTIVE
;
2874 objp
+= obj_offset(cachep
);
2875 if (cachep
->ctor
&& cachep
->flags
& SLAB_POISON
)
2877 if (ARCH_SLAB_MINALIGN
&&
2878 ((unsigned long)objp
& (ARCH_SLAB_MINALIGN
-1))) {
2879 printk(KERN_ERR
"0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
2880 objp
, (int)ARCH_SLAB_MINALIGN
);
2885 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
2888 static inline void *____cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2891 struct array_cache
*ac
;
2892 bool force_refill
= false;
2896 ac
= cpu_cache_get(cachep
);
2897 if (likely(ac
->avail
)) {
2899 objp
= ac_get_obj(cachep
, ac
, flags
, false);
2902 * Allow for the possibility all avail objects are not allowed
2903 * by the current flags
2906 STATS_INC_ALLOCHIT(cachep
);
2909 force_refill
= true;
2912 STATS_INC_ALLOCMISS(cachep
);
2913 objp
= cache_alloc_refill(cachep
, flags
, force_refill
);
2915 * the 'ac' may be updated by cache_alloc_refill(),
2916 * and kmemleak_erase() requires its correct value.
2918 ac
= cpu_cache_get(cachep
);
2922 * To avoid a false negative, if an object that is in one of the
2923 * per-CPU caches is leaked, we need to make sure kmemleak doesn't
2924 * treat the array pointers as a reference to the object.
2927 kmemleak_erase(&ac
->entry
[ac
->avail
]);
2933 * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set.
2935 * If we are in_interrupt, then process context, including cpusets and
2936 * mempolicy, may not apply and should not be used for allocation policy.
2938 static void *alternate_node_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2940 int nid_alloc
, nid_here
;
2942 if (in_interrupt() || (flags
& __GFP_THISNODE
))
2944 nid_alloc
= nid_here
= numa_mem_id();
2945 if (cpuset_do_slab_mem_spread() && (cachep
->flags
& SLAB_MEM_SPREAD
))
2946 nid_alloc
= cpuset_slab_spread_node();
2947 else if (current
->mempolicy
)
2948 nid_alloc
= mempolicy_slab_node();
2949 if (nid_alloc
!= nid_here
)
2950 return ____cache_alloc_node(cachep
, flags
, nid_alloc
);
2955 * Fallback function if there was no memory available and no objects on a
2956 * certain node and fall back is permitted. First we scan all the
2957 * available node for available objects. If that fails then we
2958 * perform an allocation without specifying a node. This allows the page
2959 * allocator to do its reclaim / fallback magic. We then insert the
2960 * slab into the proper nodelist and then allocate from it.
2962 static void *fallback_alloc(struct kmem_cache
*cache
, gfp_t flags
)
2964 struct zonelist
*zonelist
;
2968 enum zone_type high_zoneidx
= gfp_zone(flags
);
2971 unsigned int cpuset_mems_cookie
;
2973 if (flags
& __GFP_THISNODE
)
2976 local_flags
= flags
& (GFP_CONSTRAINT_MASK
|GFP_RECLAIM_MASK
);
2979 cpuset_mems_cookie
= read_mems_allowed_begin();
2980 zonelist
= node_zonelist(mempolicy_slab_node(), flags
);
2984 * Look through allowed nodes for objects available
2985 * from existing per node queues.
2987 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
2988 nid
= zone_to_nid(zone
);
2990 if (cpuset_zone_allowed(zone
, flags
) &&
2991 get_node(cache
, nid
) &&
2992 get_node(cache
, nid
)->free_objects
) {
2993 obj
= ____cache_alloc_node(cache
,
2994 gfp_exact_node(flags
), nid
);
3002 * This allocation will be performed within the constraints
3003 * of the current cpuset / memory policy requirements.
3004 * We may trigger various forms of reclaim on the allowed
3005 * set and go into memory reserves if necessary.
3009 if (gfpflags_allow_blocking(local_flags
))
3011 kmem_flagcheck(cache
, flags
);
3012 page
= kmem_getpages(cache
, local_flags
, numa_mem_id());
3013 if (gfpflags_allow_blocking(local_flags
))
3014 local_irq_disable();
3017 * Insert into the appropriate per node queues
3019 nid
= page_to_nid(page
);
3020 if (cache_grow(cache
, flags
, nid
, page
)) {
3021 obj
= ____cache_alloc_node(cache
,
3022 gfp_exact_node(flags
), nid
);
3025 * Another processor may allocate the
3026 * objects in the slab since we are
3027 * not holding any locks.
3031 /* cache_grow already freed obj */
3037 if (unlikely(!obj
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3043 * A interface to enable slab creation on nodeid
3045 static void *____cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
,
3049 struct kmem_cache_node
*n
;
3053 VM_BUG_ON(nodeid
< 0 || nodeid
>= MAX_NUMNODES
);
3054 n
= get_node(cachep
, nodeid
);
3059 spin_lock(&n
->list_lock
);
3060 page
= get_first_slab(n
);
3064 check_spinlock_acquired_node(cachep
, nodeid
);
3066 STATS_INC_NODEALLOCS(cachep
);
3067 STATS_INC_ACTIVE(cachep
);
3068 STATS_SET_HIGH(cachep
);
3070 BUG_ON(page
->active
== cachep
->num
);
3072 obj
= slab_get_obj(cachep
, page
);
3074 /* move slabp to correct slabp list: */
3075 list_del(&page
->lru
);
3077 if (page
->active
== cachep
->num
)
3078 list_add(&page
->lru
, &n
->slabs_full
);
3080 list_add(&page
->lru
, &n
->slabs_partial
);
3082 spin_unlock(&n
->list_lock
);
3086 spin_unlock(&n
->list_lock
);
3087 x
= cache_grow(cachep
, gfp_exact_node(flags
), nodeid
, NULL
);
3091 return fallback_alloc(cachep
, flags
);
3097 static __always_inline
void *
3098 slab_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
,
3099 unsigned long caller
)
3101 unsigned long save_flags
;
3103 int slab_node
= numa_mem_id();
3105 flags
&= gfp_allowed_mask
;
3106 cachep
= slab_pre_alloc_hook(cachep
, flags
);
3107 if (unlikely(!cachep
))
3110 cache_alloc_debugcheck_before(cachep
, flags
);
3111 local_irq_save(save_flags
);
3113 if (nodeid
== NUMA_NO_NODE
)
3116 if (unlikely(!get_node(cachep
, nodeid
))) {
3117 /* Node not bootstrapped yet */
3118 ptr
= fallback_alloc(cachep
, flags
);
3122 if (nodeid
== slab_node
) {
3124 * Use the locally cached objects if possible.
3125 * However ____cache_alloc does not allow fallback
3126 * to other nodes. It may fail while we still have
3127 * objects on other nodes available.
3129 ptr
= ____cache_alloc(cachep
, flags
);
3133 /* ___cache_alloc_node can fall back to other nodes */
3134 ptr
= ____cache_alloc_node(cachep
, flags
, nodeid
);
3136 local_irq_restore(save_flags
);
3137 ptr
= cache_alloc_debugcheck_after(cachep
, flags
, ptr
, caller
);
3139 if (unlikely(flags
& __GFP_ZERO
) && ptr
)
3140 memset(ptr
, 0, cachep
->object_size
);
3142 slab_post_alloc_hook(cachep
, flags
, 1, &ptr
);
3146 static __always_inline
void *
3147 __do_cache_alloc(struct kmem_cache
*cache
, gfp_t flags
)
3151 if (current
->mempolicy
|| cpuset_do_slab_mem_spread()) {
3152 objp
= alternate_node_alloc(cache
, flags
);
3156 objp
= ____cache_alloc(cache
, flags
);
3159 * We may just have run out of memory on the local node.
3160 * ____cache_alloc_node() knows how to locate memory on other nodes
3163 objp
= ____cache_alloc_node(cache
, flags
, numa_mem_id());
3170 static __always_inline
void *
3171 __do_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3173 return ____cache_alloc(cachep
, flags
);
3176 #endif /* CONFIG_NUMA */
3178 static __always_inline
void *
3179 slab_alloc(struct kmem_cache
*cachep
, gfp_t flags
, unsigned long caller
)
3181 unsigned long save_flags
;
3184 flags
&= gfp_allowed_mask
;
3185 cachep
= slab_pre_alloc_hook(cachep
, flags
);
3186 if (unlikely(!cachep
))
3189 cache_alloc_debugcheck_before(cachep
, flags
);
3190 local_irq_save(save_flags
);
3191 objp
= __do_cache_alloc(cachep
, flags
);
3192 local_irq_restore(save_flags
);
3193 objp
= cache_alloc_debugcheck_after(cachep
, flags
, objp
, caller
);
3196 if (unlikely(flags
& __GFP_ZERO
) && objp
)
3197 memset(objp
, 0, cachep
->object_size
);
3199 slab_post_alloc_hook(cachep
, flags
, 1, &objp
);
3204 * Caller needs to acquire correct kmem_cache_node's list_lock
3205 * @list: List of detached free slabs should be freed by caller
3207 static void free_block(struct kmem_cache
*cachep
, void **objpp
,
3208 int nr_objects
, int node
, struct list_head
*list
)
3211 struct kmem_cache_node
*n
= get_node(cachep
, node
);
3213 for (i
= 0; i
< nr_objects
; i
++) {
3217 clear_obj_pfmemalloc(&objpp
[i
]);
3220 page
= virt_to_head_page(objp
);
3221 list_del(&page
->lru
);
3222 check_spinlock_acquired_node(cachep
, node
);
3223 slab_put_obj(cachep
, page
, objp
);
3224 STATS_DEC_ACTIVE(cachep
);
3227 /* fixup slab chains */
3228 if (page
->active
== 0) {
3229 if (n
->free_objects
> n
->free_limit
) {
3230 n
->free_objects
-= cachep
->num
;
3231 list_add_tail(&page
->lru
, list
);
3233 list_add(&page
->lru
, &n
->slabs_free
);
3236 /* Unconditionally move a slab to the end of the
3237 * partial list on free - maximum time for the
3238 * other objects to be freed, too.
3240 list_add_tail(&page
->lru
, &n
->slabs_partial
);
3245 static void cache_flusharray(struct kmem_cache
*cachep
, struct array_cache
*ac
)
3248 struct kmem_cache_node
*n
;
3249 int node
= numa_mem_id();
3252 batchcount
= ac
->batchcount
;
3255 n
= get_node(cachep
, node
);
3256 spin_lock(&n
->list_lock
);
3258 struct array_cache
*shared_array
= n
->shared
;
3259 int max
= shared_array
->limit
- shared_array
->avail
;
3261 if (batchcount
> max
)
3263 memcpy(&(shared_array
->entry
[shared_array
->avail
]),
3264 ac
->entry
, sizeof(void *) * batchcount
);
3265 shared_array
->avail
+= batchcount
;
3270 free_block(cachep
, ac
->entry
, batchcount
, node
, &list
);
3277 list_for_each_entry(page
, &n
->slabs_free
, lru
) {
3278 BUG_ON(page
->active
);
3282 STATS_SET_FREEABLE(cachep
, i
);
3285 spin_unlock(&n
->list_lock
);
3286 slabs_destroy(cachep
, &list
);
3287 ac
->avail
-= batchcount
;
3288 memmove(ac
->entry
, &(ac
->entry
[batchcount
]), sizeof(void *)*ac
->avail
);
3292 * Release an obj back to its cache. If the obj has a constructed state, it must
3293 * be in this state _before_ it is released. Called with disabled ints.
3295 static inline void __cache_free(struct kmem_cache
*cachep
, void *objp
,
3296 unsigned long caller
)
3298 struct array_cache
*ac
= cpu_cache_get(cachep
);
3301 kmemleak_free_recursive(objp
, cachep
->flags
);
3302 objp
= cache_free_debugcheck(cachep
, objp
, caller
);
3304 kmemcheck_slab_free(cachep
, objp
, cachep
->object_size
);
3307 * Skip calling cache_free_alien() when the platform is not numa.
3308 * This will avoid cache misses that happen while accessing slabp (which
3309 * is per page memory reference) to get nodeid. Instead use a global
3310 * variable to skip the call, which is mostly likely to be present in
3313 if (nr_online_nodes
> 1 && cache_free_alien(cachep
, objp
))
3316 if (ac
->avail
< ac
->limit
) {
3317 STATS_INC_FREEHIT(cachep
);
3319 STATS_INC_FREEMISS(cachep
);
3320 cache_flusharray(cachep
, ac
);
3323 ac_put_obj(cachep
, ac
, objp
);
3327 * kmem_cache_alloc - Allocate an object
3328 * @cachep: The cache to allocate from.
3329 * @flags: See kmalloc().
3331 * Allocate an object from this cache. The flags are only relevant
3332 * if the cache has no available objects.
3334 void *kmem_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3336 void *ret
= slab_alloc(cachep
, flags
, _RET_IP_
);
3338 trace_kmem_cache_alloc(_RET_IP_
, ret
,
3339 cachep
->object_size
, cachep
->size
, flags
);
3343 EXPORT_SYMBOL(kmem_cache_alloc
);
3345 static __always_inline
void
3346 cache_alloc_debugcheck_after_bulk(struct kmem_cache
*s
, gfp_t flags
,
3347 size_t size
, void **p
, unsigned long caller
)
3351 for (i
= 0; i
< size
; i
++)
3352 p
[i
] = cache_alloc_debugcheck_after(s
, flags
, p
[i
], caller
);
3355 int kmem_cache_alloc_bulk(struct kmem_cache
*s
, gfp_t flags
, size_t size
,
3360 s
= slab_pre_alloc_hook(s
, flags
);
3364 cache_alloc_debugcheck_before(s
, flags
);
3366 local_irq_disable();
3367 for (i
= 0; i
< size
; i
++) {
3368 void *objp
= __do_cache_alloc(s
, flags
);
3370 if (unlikely(!objp
))
3376 cache_alloc_debugcheck_after_bulk(s
, flags
, size
, p
, _RET_IP_
);
3378 /* Clear memory outside IRQ disabled section */
3379 if (unlikely(flags
& __GFP_ZERO
))
3380 for (i
= 0; i
< size
; i
++)
3381 memset(p
[i
], 0, s
->object_size
);
3383 slab_post_alloc_hook(s
, flags
, size
, p
);
3384 /* FIXME: Trace call missing. Christoph would like a bulk variant */
3388 cache_alloc_debugcheck_after_bulk(s
, flags
, i
, p
, _RET_IP_
);
3389 slab_post_alloc_hook(s
, flags
, i
, p
);
3390 __kmem_cache_free_bulk(s
, i
, p
);
3393 EXPORT_SYMBOL(kmem_cache_alloc_bulk
);
3395 #ifdef CONFIG_TRACING
3397 kmem_cache_alloc_trace(struct kmem_cache
*cachep
, gfp_t flags
, size_t size
)
3401 ret
= slab_alloc(cachep
, flags
, _RET_IP_
);
3403 trace_kmalloc(_RET_IP_
, ret
,
3404 size
, cachep
->size
, flags
);
3407 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
3412 * kmem_cache_alloc_node - Allocate an object on the specified node
3413 * @cachep: The cache to allocate from.
3414 * @flags: See kmalloc().
3415 * @nodeid: node number of the target node.
3417 * Identical to kmem_cache_alloc but it will allocate memory on the given
3418 * node, which can improve the performance for cpu bound structures.
3420 * Fallback to other node is possible if __GFP_THISNODE is not set.
3422 void *kmem_cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
3424 void *ret
= slab_alloc_node(cachep
, flags
, nodeid
, _RET_IP_
);
3426 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
3427 cachep
->object_size
, cachep
->size
,
3432 EXPORT_SYMBOL(kmem_cache_alloc_node
);
3434 #ifdef CONFIG_TRACING
3435 void *kmem_cache_alloc_node_trace(struct kmem_cache
*cachep
,
3442 ret
= slab_alloc_node(cachep
, flags
, nodeid
, _RET_IP_
);
3444 trace_kmalloc_node(_RET_IP_
, ret
,
3449 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
3452 static __always_inline
void *
3453 __do_kmalloc_node(size_t size
, gfp_t flags
, int node
, unsigned long caller
)
3455 struct kmem_cache
*cachep
;
3457 cachep
= kmalloc_slab(size
, flags
);
3458 if (unlikely(ZERO_OR_NULL_PTR(cachep
)))
3460 return kmem_cache_alloc_node_trace(cachep
, flags
, node
, size
);
3463 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3465 return __do_kmalloc_node(size
, flags
, node
, _RET_IP_
);
3467 EXPORT_SYMBOL(__kmalloc_node
);
3469 void *__kmalloc_node_track_caller(size_t size
, gfp_t flags
,
3470 int node
, unsigned long caller
)
3472 return __do_kmalloc_node(size
, flags
, node
, caller
);
3474 EXPORT_SYMBOL(__kmalloc_node_track_caller
);
3475 #endif /* CONFIG_NUMA */
3478 * __do_kmalloc - allocate memory
3479 * @size: how many bytes of memory are required.
3480 * @flags: the type of memory to allocate (see kmalloc).
3481 * @caller: function caller for debug tracking of the caller
3483 static __always_inline
void *__do_kmalloc(size_t size
, gfp_t flags
,
3484 unsigned long caller
)
3486 struct kmem_cache
*cachep
;
3489 cachep
= kmalloc_slab(size
, flags
);
3490 if (unlikely(ZERO_OR_NULL_PTR(cachep
)))
3492 ret
= slab_alloc(cachep
, flags
, caller
);
3494 trace_kmalloc(caller
, ret
,
3495 size
, cachep
->size
, flags
);
3500 void *__kmalloc(size_t size
, gfp_t flags
)
3502 return __do_kmalloc(size
, flags
, _RET_IP_
);
3504 EXPORT_SYMBOL(__kmalloc
);
3506 void *__kmalloc_track_caller(size_t size
, gfp_t flags
, unsigned long caller
)
3508 return __do_kmalloc(size
, flags
, caller
);
3510 EXPORT_SYMBOL(__kmalloc_track_caller
);
3513 * kmem_cache_free - Deallocate an object
3514 * @cachep: The cache the allocation was from.
3515 * @objp: The previously allocated object.
3517 * Free an object which was previously allocated from this
3520 void kmem_cache_free(struct kmem_cache
*cachep
, void *objp
)
3522 unsigned long flags
;
3523 cachep
= cache_from_obj(cachep
, objp
);
3527 local_irq_save(flags
);
3528 debug_check_no_locks_freed(objp
, cachep
->object_size
);
3529 if (!(cachep
->flags
& SLAB_DEBUG_OBJECTS
))
3530 debug_check_no_obj_freed(objp
, cachep
->object_size
);
3531 __cache_free(cachep
, objp
, _RET_IP_
);
3532 local_irq_restore(flags
);
3534 trace_kmem_cache_free(_RET_IP_
, objp
);
3536 EXPORT_SYMBOL(kmem_cache_free
);
3538 void kmem_cache_free_bulk(struct kmem_cache
*orig_s
, size_t size
, void **p
)
3540 struct kmem_cache
*s
;
3543 local_irq_disable();
3544 for (i
= 0; i
< size
; i
++) {
3547 if (!orig_s
) /* called via kfree_bulk */
3548 s
= virt_to_cache(objp
);
3550 s
= cache_from_obj(orig_s
, objp
);
3552 debug_check_no_locks_freed(objp
, s
->object_size
);
3553 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
3554 debug_check_no_obj_freed(objp
, s
->object_size
);
3556 __cache_free(s
, objp
, _RET_IP_
);
3560 /* FIXME: add tracing */
3562 EXPORT_SYMBOL(kmem_cache_free_bulk
);
3565 * kfree - free previously allocated memory
3566 * @objp: pointer returned by kmalloc.
3568 * If @objp is NULL, no operation is performed.
3570 * Don't free memory not originally allocated by kmalloc()
3571 * or you will run into trouble.
3573 void kfree(const void *objp
)
3575 struct kmem_cache
*c
;
3576 unsigned long flags
;
3578 trace_kfree(_RET_IP_
, objp
);
3580 if (unlikely(ZERO_OR_NULL_PTR(objp
)))
3582 local_irq_save(flags
);
3583 kfree_debugcheck(objp
);
3584 c
= virt_to_cache(objp
);
3585 debug_check_no_locks_freed(objp
, c
->object_size
);
3587 debug_check_no_obj_freed(objp
, c
->object_size
);
3588 __cache_free(c
, (void *)objp
, _RET_IP_
);
3589 local_irq_restore(flags
);
3591 EXPORT_SYMBOL(kfree
);
3594 * This initializes kmem_cache_node or resizes various caches for all nodes.
3596 static int alloc_kmem_cache_node(struct kmem_cache
*cachep
, gfp_t gfp
)
3599 struct kmem_cache_node
*n
;
3600 struct array_cache
*new_shared
;
3601 struct alien_cache
**new_alien
= NULL
;
3603 for_each_online_node(node
) {
3605 if (use_alien_caches
) {
3606 new_alien
= alloc_alien_cache(node
, cachep
->limit
, gfp
);
3612 if (cachep
->shared
) {
3613 new_shared
= alloc_arraycache(node
,
3614 cachep
->shared
*cachep
->batchcount
,
3617 free_alien_cache(new_alien
);
3622 n
= get_node(cachep
, node
);
3624 struct array_cache
*shared
= n
->shared
;
3627 spin_lock_irq(&n
->list_lock
);
3630 free_block(cachep
, shared
->entry
,
3631 shared
->avail
, node
, &list
);
3633 n
->shared
= new_shared
;
3635 n
->alien
= new_alien
;
3638 n
->free_limit
= (1 + nr_cpus_node(node
)) *
3639 cachep
->batchcount
+ cachep
->num
;
3640 spin_unlock_irq(&n
->list_lock
);
3641 slabs_destroy(cachep
, &list
);
3643 free_alien_cache(new_alien
);
3646 n
= kmalloc_node(sizeof(struct kmem_cache_node
), gfp
, node
);
3648 free_alien_cache(new_alien
);
3653 kmem_cache_node_init(n
);
3654 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
+
3655 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
3656 n
->shared
= new_shared
;
3657 n
->alien
= new_alien
;
3658 n
->free_limit
= (1 + nr_cpus_node(node
)) *
3659 cachep
->batchcount
+ cachep
->num
;
3660 cachep
->node
[node
] = n
;
3665 if (!cachep
->list
.next
) {
3666 /* Cache is not active yet. Roll back what we did */
3669 n
= get_node(cachep
, node
);
3672 free_alien_cache(n
->alien
);
3674 cachep
->node
[node
] = NULL
;
3682 /* Always called with the slab_mutex held */
3683 static int __do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3684 int batchcount
, int shared
, gfp_t gfp
)
3686 struct array_cache __percpu
*cpu_cache
, *prev
;
3689 cpu_cache
= alloc_kmem_cache_cpus(cachep
, limit
, batchcount
);
3693 prev
= cachep
->cpu_cache
;
3694 cachep
->cpu_cache
= cpu_cache
;
3695 kick_all_cpus_sync();
3698 cachep
->batchcount
= batchcount
;
3699 cachep
->limit
= limit
;
3700 cachep
->shared
= shared
;
3705 for_each_online_cpu(cpu
) {
3708 struct kmem_cache_node
*n
;
3709 struct array_cache
*ac
= per_cpu_ptr(prev
, cpu
);
3711 node
= cpu_to_mem(cpu
);
3712 n
= get_node(cachep
, node
);
3713 spin_lock_irq(&n
->list_lock
);
3714 free_block(cachep
, ac
->entry
, ac
->avail
, node
, &list
);
3715 spin_unlock_irq(&n
->list_lock
);
3716 slabs_destroy(cachep
, &list
);
3721 return alloc_kmem_cache_node(cachep
, gfp
);
3724 static int do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3725 int batchcount
, int shared
, gfp_t gfp
)
3728 struct kmem_cache
*c
;
3730 ret
= __do_tune_cpucache(cachep
, limit
, batchcount
, shared
, gfp
);
3732 if (slab_state
< FULL
)
3735 if ((ret
< 0) || !is_root_cache(cachep
))
3738 lockdep_assert_held(&slab_mutex
);
3739 for_each_memcg_cache(c
, cachep
) {
3740 /* return value determined by the root cache only */
3741 __do_tune_cpucache(c
, limit
, batchcount
, shared
, gfp
);
3747 /* Called with slab_mutex held always */
3748 static int enable_cpucache(struct kmem_cache
*cachep
, gfp_t gfp
)
3755 if (!is_root_cache(cachep
)) {
3756 struct kmem_cache
*root
= memcg_root_cache(cachep
);
3757 limit
= root
->limit
;
3758 shared
= root
->shared
;
3759 batchcount
= root
->batchcount
;
3762 if (limit
&& shared
&& batchcount
)
3765 * The head array serves three purposes:
3766 * - create a LIFO ordering, i.e. return objects that are cache-warm
3767 * - reduce the number of spinlock operations.
3768 * - reduce the number of linked list operations on the slab and
3769 * bufctl chains: array operations are cheaper.
3770 * The numbers are guessed, we should auto-tune as described by
3773 if (cachep
->size
> 131072)
3775 else if (cachep
->size
> PAGE_SIZE
)
3777 else if (cachep
->size
> 1024)
3779 else if (cachep
->size
> 256)
3785 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3786 * allocation behaviour: Most allocs on one cpu, most free operations
3787 * on another cpu. For these cases, an efficient object passing between
3788 * cpus is necessary. This is provided by a shared array. The array
3789 * replaces Bonwick's magazine layer.
3790 * On uniprocessor, it's functionally equivalent (but less efficient)
3791 * to a larger limit. Thus disabled by default.
3794 if (cachep
->size
<= PAGE_SIZE
&& num_possible_cpus() > 1)
3799 * With debugging enabled, large batchcount lead to excessively long
3800 * periods with disabled local interrupts. Limit the batchcount
3805 batchcount
= (limit
+ 1) / 2;
3807 err
= do_tune_cpucache(cachep
, limit
, batchcount
, shared
, gfp
);
3809 printk(KERN_ERR
"enable_cpucache failed for %s, error %d.\n",
3810 cachep
->name
, -err
);
3815 * Drain an array if it contains any elements taking the node lock only if
3816 * necessary. Note that the node listlock also protects the array_cache
3817 * if drain_array() is used on the shared array.
3819 static void drain_array(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
,
3820 struct array_cache
*ac
, int force
, int node
)
3825 if (!ac
|| !ac
->avail
)
3827 if (ac
->touched
&& !force
) {
3830 spin_lock_irq(&n
->list_lock
);
3832 tofree
= force
? ac
->avail
: (ac
->limit
+ 4) / 5;
3833 if (tofree
> ac
->avail
)
3834 tofree
= (ac
->avail
+ 1) / 2;
3835 free_block(cachep
, ac
->entry
, tofree
, node
, &list
);
3836 ac
->avail
-= tofree
;
3837 memmove(ac
->entry
, &(ac
->entry
[tofree
]),
3838 sizeof(void *) * ac
->avail
);
3840 spin_unlock_irq(&n
->list_lock
);
3841 slabs_destroy(cachep
, &list
);
3846 * cache_reap - Reclaim memory from caches.
3847 * @w: work descriptor
3849 * Called from workqueue/eventd every few seconds.
3851 * - clear the per-cpu caches for this CPU.
3852 * - return freeable pages to the main free memory pool.
3854 * If we cannot acquire the cache chain mutex then just give up - we'll try
3855 * again on the next iteration.
3857 static void cache_reap(struct work_struct
*w
)
3859 struct kmem_cache
*searchp
;
3860 struct kmem_cache_node
*n
;
3861 int node
= numa_mem_id();
3862 struct delayed_work
*work
= to_delayed_work(w
);
3864 if (!mutex_trylock(&slab_mutex
))
3865 /* Give up. Setup the next iteration. */
3868 list_for_each_entry(searchp
, &slab_caches
, list
) {
3872 * We only take the node lock if absolutely necessary and we
3873 * have established with reasonable certainty that
3874 * we can do some work if the lock was obtained.
3876 n
= get_node(searchp
, node
);
3878 reap_alien(searchp
, n
);
3880 drain_array(searchp
, n
, cpu_cache_get(searchp
), 0, node
);
3883 * These are racy checks but it does not matter
3884 * if we skip one check or scan twice.
3886 if (time_after(n
->next_reap
, jiffies
))
3889 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
;
3891 drain_array(searchp
, n
, n
->shared
, 0, node
);
3893 if (n
->free_touched
)
3894 n
->free_touched
= 0;
3898 freed
= drain_freelist(searchp
, n
, (n
->free_limit
+
3899 5 * searchp
->num
- 1) / (5 * searchp
->num
));
3900 STATS_ADD_REAPED(searchp
, freed
);
3906 mutex_unlock(&slab_mutex
);
3909 /* Set up the next iteration */
3910 schedule_delayed_work(work
, round_jiffies_relative(REAPTIMEOUT_AC
));
3913 #ifdef CONFIG_SLABINFO
3914 void get_slabinfo(struct kmem_cache
*cachep
, struct slabinfo
*sinfo
)
3917 unsigned long active_objs
;
3918 unsigned long num_objs
;
3919 unsigned long active_slabs
= 0;
3920 unsigned long num_slabs
, free_objects
= 0, shared_avail
= 0;
3924 struct kmem_cache_node
*n
;
3928 for_each_kmem_cache_node(cachep
, node
, n
) {
3931 spin_lock_irq(&n
->list_lock
);
3933 list_for_each_entry(page
, &n
->slabs_full
, lru
) {
3934 if (page
->active
!= cachep
->num
&& !error
)
3935 error
= "slabs_full accounting error";
3936 active_objs
+= cachep
->num
;
3939 list_for_each_entry(page
, &n
->slabs_partial
, lru
) {
3940 if (page
->active
== cachep
->num
&& !error
)
3941 error
= "slabs_partial accounting error";
3942 if (!page
->active
&& !error
)
3943 error
= "slabs_partial accounting error";
3944 active_objs
+= page
->active
;
3947 list_for_each_entry(page
, &n
->slabs_free
, lru
) {
3948 if (page
->active
&& !error
)
3949 error
= "slabs_free accounting error";
3952 free_objects
+= n
->free_objects
;
3954 shared_avail
+= n
->shared
->avail
;
3956 spin_unlock_irq(&n
->list_lock
);
3958 num_slabs
+= active_slabs
;
3959 num_objs
= num_slabs
* cachep
->num
;
3960 if (num_objs
- active_objs
!= free_objects
&& !error
)
3961 error
= "free_objects accounting error";
3963 name
= cachep
->name
;
3965 printk(KERN_ERR
"slab: cache %s error: %s\n", name
, error
);
3967 sinfo
->active_objs
= active_objs
;
3968 sinfo
->num_objs
= num_objs
;
3969 sinfo
->active_slabs
= active_slabs
;
3970 sinfo
->num_slabs
= num_slabs
;
3971 sinfo
->shared_avail
= shared_avail
;
3972 sinfo
->limit
= cachep
->limit
;
3973 sinfo
->batchcount
= cachep
->batchcount
;
3974 sinfo
->shared
= cachep
->shared
;
3975 sinfo
->objects_per_slab
= cachep
->num
;
3976 sinfo
->cache_order
= cachep
->gfporder
;
3979 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*cachep
)
3983 unsigned long high
= cachep
->high_mark
;
3984 unsigned long allocs
= cachep
->num_allocations
;
3985 unsigned long grown
= cachep
->grown
;
3986 unsigned long reaped
= cachep
->reaped
;
3987 unsigned long errors
= cachep
->errors
;
3988 unsigned long max_freeable
= cachep
->max_freeable
;
3989 unsigned long node_allocs
= cachep
->node_allocs
;
3990 unsigned long node_frees
= cachep
->node_frees
;
3991 unsigned long overflows
= cachep
->node_overflow
;
3993 seq_printf(m
, " : globalstat %7lu %6lu %5lu %4lu "
3994 "%4lu %4lu %4lu %4lu %4lu",
3995 allocs
, high
, grown
,
3996 reaped
, errors
, max_freeable
, node_allocs
,
3997 node_frees
, overflows
);
4001 unsigned long allochit
= atomic_read(&cachep
->allochit
);
4002 unsigned long allocmiss
= atomic_read(&cachep
->allocmiss
);
4003 unsigned long freehit
= atomic_read(&cachep
->freehit
);
4004 unsigned long freemiss
= atomic_read(&cachep
->freemiss
);
4006 seq_printf(m
, " : cpustat %6lu %6lu %6lu %6lu",
4007 allochit
, allocmiss
, freehit
, freemiss
);
4012 #define MAX_SLABINFO_WRITE 128
4014 * slabinfo_write - Tuning for the slab allocator
4016 * @buffer: user buffer
4017 * @count: data length
4020 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
4021 size_t count
, loff_t
*ppos
)
4023 char kbuf
[MAX_SLABINFO_WRITE
+ 1], *tmp
;
4024 int limit
, batchcount
, shared
, res
;
4025 struct kmem_cache
*cachep
;
4027 if (count
> MAX_SLABINFO_WRITE
)
4029 if (copy_from_user(&kbuf
, buffer
, count
))
4031 kbuf
[MAX_SLABINFO_WRITE
] = '\0';
4033 tmp
= strchr(kbuf
, ' ');
4038 if (sscanf(tmp
, " %d %d %d", &limit
, &batchcount
, &shared
) != 3)
4041 /* Find the cache in the chain of caches. */
4042 mutex_lock(&slab_mutex
);
4044 list_for_each_entry(cachep
, &slab_caches
, list
) {
4045 if (!strcmp(cachep
->name
, kbuf
)) {
4046 if (limit
< 1 || batchcount
< 1 ||
4047 batchcount
> limit
|| shared
< 0) {
4050 res
= do_tune_cpucache(cachep
, limit
,
4057 mutex_unlock(&slab_mutex
);
4063 #ifdef CONFIG_DEBUG_SLAB_LEAK
4065 static inline int add_caller(unsigned long *n
, unsigned long v
)
4075 unsigned long *q
= p
+ 2 * i
;
4089 memmove(p
+ 2, p
, n
[1] * 2 * sizeof(unsigned long) - ((void *)p
- (void *)n
));
4095 static void handle_slab(unsigned long *n
, struct kmem_cache
*c
,
4104 for (i
= 0, p
= page
->s_mem
; i
< c
->num
; i
++, p
+= c
->size
) {
4107 for (j
= page
->active
; j
< c
->num
; j
++) {
4108 if (get_free_obj(page
, j
) == i
) {
4118 * probe_kernel_read() is used for DEBUG_PAGEALLOC. page table
4119 * mapping is established when actual object allocation and
4120 * we could mistakenly access the unmapped object in the cpu
4123 if (probe_kernel_read(&v
, dbg_userword(c
, p
), sizeof(v
)))
4126 if (!add_caller(n
, v
))
4131 static void show_symbol(struct seq_file
*m
, unsigned long address
)
4133 #ifdef CONFIG_KALLSYMS
4134 unsigned long offset
, size
;
4135 char modname
[MODULE_NAME_LEN
], name
[KSYM_NAME_LEN
];
4137 if (lookup_symbol_attrs(address
, &size
, &offset
, modname
, name
) == 0) {
4138 seq_printf(m
, "%s+%#lx/%#lx", name
, offset
, size
);
4140 seq_printf(m
, " [%s]", modname
);
4144 seq_printf(m
, "%p", (void *)address
);
4147 static int leaks_show(struct seq_file
*m
, void *p
)
4149 struct kmem_cache
*cachep
= list_entry(p
, struct kmem_cache
, list
);
4151 struct kmem_cache_node
*n
;
4153 unsigned long *x
= m
->private;
4157 if (!(cachep
->flags
& SLAB_STORE_USER
))
4159 if (!(cachep
->flags
& SLAB_RED_ZONE
))
4163 * Set store_user_clean and start to grab stored user information
4164 * for all objects on this cache. If some alloc/free requests comes
4165 * during the processing, information would be wrong so restart
4169 set_store_user_clean(cachep
);
4170 drain_cpu_caches(cachep
);
4174 for_each_kmem_cache_node(cachep
, node
, n
) {
4177 spin_lock_irq(&n
->list_lock
);
4179 list_for_each_entry(page
, &n
->slabs_full
, lru
)
4180 handle_slab(x
, cachep
, page
);
4181 list_for_each_entry(page
, &n
->slabs_partial
, lru
)
4182 handle_slab(x
, cachep
, page
);
4183 spin_unlock_irq(&n
->list_lock
);
4185 } while (!is_store_user_clean(cachep
));
4187 name
= cachep
->name
;
4189 /* Increase the buffer size */
4190 mutex_unlock(&slab_mutex
);
4191 m
->private = kzalloc(x
[0] * 4 * sizeof(unsigned long), GFP_KERNEL
);
4193 /* Too bad, we are really out */
4195 mutex_lock(&slab_mutex
);
4198 *(unsigned long *)m
->private = x
[0] * 2;
4200 mutex_lock(&slab_mutex
);
4201 /* Now make sure this entry will be retried */
4205 for (i
= 0; i
< x
[1]; i
++) {
4206 seq_printf(m
, "%s: %lu ", name
, x
[2*i
+3]);
4207 show_symbol(m
, x
[2*i
+2]);
4214 static const struct seq_operations slabstats_op
= {
4215 .start
= slab_start
,
4221 static int slabstats_open(struct inode
*inode
, struct file
*file
)
4225 n
= __seq_open_private(file
, &slabstats_op
, PAGE_SIZE
);
4229 *n
= PAGE_SIZE
/ (2 * sizeof(unsigned long));
4234 static const struct file_operations proc_slabstats_operations
= {
4235 .open
= slabstats_open
,
4237 .llseek
= seq_lseek
,
4238 .release
= seq_release_private
,
4242 static int __init
slab_proc_init(void)
4244 #ifdef CONFIG_DEBUG_SLAB_LEAK
4245 proc_create("slab_allocators", 0, NULL
, &proc_slabstats_operations
);
4249 module_init(slab_proc_init
);
4253 * ksize - get the actual amount of memory allocated for a given object
4254 * @objp: Pointer to the object
4256 * kmalloc may internally round up allocations and return more memory
4257 * than requested. ksize() can be used to determine the actual amount of
4258 * memory allocated. The caller may use this additional memory, even though
4259 * a smaller amount of memory was initially specified with the kmalloc call.
4260 * The caller must guarantee that objp points to a valid object previously
4261 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4262 * must not be freed during the duration of the call.
4264 size_t ksize(const void *objp
)
4267 if (unlikely(objp
== ZERO_SIZE_PTR
))
4270 return virt_to_cache(objp
)->object_size
;
4272 EXPORT_SYMBOL(ksize
);