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
);
459 static size_t calculate_freelist_size(int nr_objs
, size_t align
)
461 size_t freelist_size
;
463 freelist_size
= nr_objs
* sizeof(freelist_idx_t
);
465 freelist_size
= ALIGN(freelist_size
, align
);
467 return freelist_size
;
470 static int calculate_nr_objs(size_t slab_size
, size_t buffer_size
,
471 size_t idx_size
, size_t align
)
474 size_t remained_size
;
475 size_t freelist_size
;
478 * Ignore padding for the initial guess. The padding
479 * is at most @align-1 bytes, and @buffer_size is at
480 * least @align. In the worst case, this result will
481 * be one greater than the number of objects that fit
482 * into the memory allocation when taking the padding
485 nr_objs
= slab_size
/ (buffer_size
+ idx_size
);
488 * This calculated number will be either the right
489 * amount, or one greater than what we want.
491 remained_size
= slab_size
- nr_objs
* buffer_size
;
492 freelist_size
= calculate_freelist_size(nr_objs
, align
);
493 if (remained_size
< freelist_size
)
500 * Calculate the number of objects and left-over bytes for a given buffer size.
502 static void cache_estimate(unsigned long gfporder
, size_t buffer_size
,
503 size_t align
, int flags
, size_t *left_over
,
508 size_t slab_size
= PAGE_SIZE
<< gfporder
;
511 * The slab management structure can be either off the slab or
512 * on it. For the latter case, the memory allocated for a
515 * - One freelist_idx_t for each object
516 * - Padding to respect alignment of @align
517 * - @buffer_size bytes for each object
519 * If the slab management structure is off the slab, then the
520 * alignment will already be calculated into the size. Because
521 * the slabs are all pages aligned, the objects will be at the
522 * correct alignment when allocated.
524 if (flags
& CFLGS_OFF_SLAB
) {
526 nr_objs
= slab_size
/ buffer_size
;
529 nr_objs
= calculate_nr_objs(slab_size
, buffer_size
,
530 sizeof(freelist_idx_t
), align
);
531 mgmt_size
= calculate_freelist_size(nr_objs
, align
);
534 *left_over
= slab_size
- nr_objs
*buffer_size
- mgmt_size
;
538 #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
540 static void __slab_error(const char *function
, struct kmem_cache
*cachep
,
543 printk(KERN_ERR
"slab error in %s(): cache `%s': %s\n",
544 function
, cachep
->name
, msg
);
546 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
551 * By default on NUMA we use alien caches to stage the freeing of
552 * objects allocated from other nodes. This causes massive memory
553 * inefficiencies when using fake NUMA setup to split memory into a
554 * large number of small nodes, so it can be disabled on the command
558 static int use_alien_caches __read_mostly
= 1;
559 static int __init
noaliencache_setup(char *s
)
561 use_alien_caches
= 0;
564 __setup("noaliencache", noaliencache_setup
);
566 static int __init
slab_max_order_setup(char *str
)
568 get_option(&str
, &slab_max_order
);
569 slab_max_order
= slab_max_order
< 0 ? 0 :
570 min(slab_max_order
, MAX_ORDER
- 1);
571 slab_max_order_set
= true;
575 __setup("slab_max_order=", slab_max_order_setup
);
579 * Special reaping functions for NUMA systems called from cache_reap().
580 * These take care of doing round robin flushing of alien caches (containing
581 * objects freed on different nodes from which they were allocated) and the
582 * flushing of remote pcps by calling drain_node_pages.
584 static DEFINE_PER_CPU(unsigned long, slab_reap_node
);
586 static void init_reap_node(int cpu
)
590 node
= next_node(cpu_to_mem(cpu
), node_online_map
);
591 if (node
== MAX_NUMNODES
)
592 node
= first_node(node_online_map
);
594 per_cpu(slab_reap_node
, cpu
) = node
;
597 static void next_reap_node(void)
599 int node
= __this_cpu_read(slab_reap_node
);
601 node
= next_node(node
, node_online_map
);
602 if (unlikely(node
>= MAX_NUMNODES
))
603 node
= first_node(node_online_map
);
604 __this_cpu_write(slab_reap_node
, node
);
608 #define init_reap_node(cpu) do { } while (0)
609 #define next_reap_node(void) do { } while (0)
613 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
614 * via the workqueue/eventd.
615 * Add the CPU number into the expiration time to minimize the possibility of
616 * the CPUs getting into lockstep and contending for the global cache chain
619 static void start_cpu_timer(int cpu
)
621 struct delayed_work
*reap_work
= &per_cpu(slab_reap_work
, cpu
);
624 * When this gets called from do_initcalls via cpucache_init(),
625 * init_workqueues() has already run, so keventd will be setup
628 if (keventd_up() && reap_work
->work
.func
== NULL
) {
630 INIT_DEFERRABLE_WORK(reap_work
, cache_reap
);
631 schedule_delayed_work_on(cpu
, reap_work
,
632 __round_jiffies_relative(HZ
, cpu
));
636 static void init_arraycache(struct array_cache
*ac
, int limit
, int batch
)
639 * The array_cache structures contain pointers to free object.
640 * However, when such objects are allocated or transferred to another
641 * cache the pointers are not cleared and they could be counted as
642 * valid references during a kmemleak scan. Therefore, kmemleak must
643 * not scan such objects.
645 kmemleak_no_scan(ac
);
649 ac
->batchcount
= batch
;
654 static struct array_cache
*alloc_arraycache(int node
, int entries
,
655 int batchcount
, gfp_t gfp
)
657 size_t memsize
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
658 struct array_cache
*ac
= NULL
;
660 ac
= kmalloc_node(memsize
, gfp
, node
);
661 init_arraycache(ac
, entries
, batchcount
);
665 static inline bool is_slab_pfmemalloc(struct page
*page
)
667 return PageSlabPfmemalloc(page
);
670 /* Clears pfmemalloc_active if no slabs have pfmalloc set */
671 static void recheck_pfmemalloc_active(struct kmem_cache
*cachep
,
672 struct array_cache
*ac
)
674 struct kmem_cache_node
*n
= get_node(cachep
, numa_mem_id());
678 if (!pfmemalloc_active
)
681 spin_lock_irqsave(&n
->list_lock
, flags
);
682 list_for_each_entry(page
, &n
->slabs_full
, lru
)
683 if (is_slab_pfmemalloc(page
))
686 list_for_each_entry(page
, &n
->slabs_partial
, lru
)
687 if (is_slab_pfmemalloc(page
))
690 list_for_each_entry(page
, &n
->slabs_free
, lru
)
691 if (is_slab_pfmemalloc(page
))
694 pfmemalloc_active
= false;
696 spin_unlock_irqrestore(&n
->list_lock
, flags
);
699 static void *__ac_get_obj(struct kmem_cache
*cachep
, struct array_cache
*ac
,
700 gfp_t flags
, bool force_refill
)
703 void *objp
= ac
->entry
[--ac
->avail
];
705 /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */
706 if (unlikely(is_obj_pfmemalloc(objp
))) {
707 struct kmem_cache_node
*n
;
709 if (gfp_pfmemalloc_allowed(flags
)) {
710 clear_obj_pfmemalloc(&objp
);
714 /* The caller cannot use PFMEMALLOC objects, find another one */
715 for (i
= 0; i
< ac
->avail
; i
++) {
716 /* If a !PFMEMALLOC object is found, swap them */
717 if (!is_obj_pfmemalloc(ac
->entry
[i
])) {
719 ac
->entry
[i
] = ac
->entry
[ac
->avail
];
720 ac
->entry
[ac
->avail
] = objp
;
726 * If there are empty slabs on the slabs_free list and we are
727 * being forced to refill the cache, mark this one !pfmemalloc.
729 n
= get_node(cachep
, numa_mem_id());
730 if (!list_empty(&n
->slabs_free
) && force_refill
) {
731 struct page
*page
= virt_to_head_page(objp
);
732 ClearPageSlabPfmemalloc(page
);
733 clear_obj_pfmemalloc(&objp
);
734 recheck_pfmemalloc_active(cachep
, ac
);
738 /* No !PFMEMALLOC objects available */
746 static inline void *ac_get_obj(struct kmem_cache
*cachep
,
747 struct array_cache
*ac
, gfp_t flags
, bool force_refill
)
751 if (unlikely(sk_memalloc_socks()))
752 objp
= __ac_get_obj(cachep
, ac
, flags
, force_refill
);
754 objp
= ac
->entry
[--ac
->avail
];
759 static noinline
void *__ac_put_obj(struct kmem_cache
*cachep
,
760 struct array_cache
*ac
, void *objp
)
762 if (unlikely(pfmemalloc_active
)) {
763 /* Some pfmemalloc slabs exist, check if this is one */
764 struct page
*page
= virt_to_head_page(objp
);
765 if (PageSlabPfmemalloc(page
))
766 set_obj_pfmemalloc(&objp
);
772 static inline void ac_put_obj(struct kmem_cache
*cachep
, struct array_cache
*ac
,
775 if (unlikely(sk_memalloc_socks()))
776 objp
= __ac_put_obj(cachep
, ac
, objp
);
778 ac
->entry
[ac
->avail
++] = objp
;
782 * Transfer objects in one arraycache to another.
783 * Locking must be handled by the caller.
785 * Return the number of entries transferred.
787 static int transfer_objects(struct array_cache
*to
,
788 struct array_cache
*from
, unsigned int max
)
790 /* Figure out how many entries to transfer */
791 int nr
= min3(from
->avail
, max
, to
->limit
- to
->avail
);
796 memcpy(to
->entry
+ to
->avail
, from
->entry
+ from
->avail
-nr
,
806 #define drain_alien_cache(cachep, alien) do { } while (0)
807 #define reap_alien(cachep, n) do { } while (0)
809 static inline struct alien_cache
**alloc_alien_cache(int node
,
810 int limit
, gfp_t gfp
)
812 return (struct alien_cache
**)BAD_ALIEN_MAGIC
;
815 static inline void free_alien_cache(struct alien_cache
**ac_ptr
)
819 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
824 static inline void *alternate_node_alloc(struct kmem_cache
*cachep
,
830 static inline void *____cache_alloc_node(struct kmem_cache
*cachep
,
831 gfp_t flags
, int nodeid
)
836 static inline gfp_t
gfp_exact_node(gfp_t flags
)
841 #else /* CONFIG_NUMA */
843 static void *____cache_alloc_node(struct kmem_cache
*, gfp_t
, int);
844 static void *alternate_node_alloc(struct kmem_cache
*, gfp_t
);
846 static struct alien_cache
*__alloc_alien_cache(int node
, int entries
,
847 int batch
, gfp_t gfp
)
849 size_t memsize
= sizeof(void *) * entries
+ sizeof(struct alien_cache
);
850 struct alien_cache
*alc
= NULL
;
852 alc
= kmalloc_node(memsize
, gfp
, node
);
853 init_arraycache(&alc
->ac
, entries
, batch
);
854 spin_lock_init(&alc
->lock
);
858 static struct alien_cache
**alloc_alien_cache(int node
, int limit
, gfp_t gfp
)
860 struct alien_cache
**alc_ptr
;
861 size_t memsize
= sizeof(void *) * nr_node_ids
;
866 alc_ptr
= kzalloc_node(memsize
, gfp
, node
);
871 if (i
== node
|| !node_online(i
))
873 alc_ptr
[i
] = __alloc_alien_cache(node
, limit
, 0xbaadf00d, gfp
);
875 for (i
--; i
>= 0; i
--)
884 static void free_alien_cache(struct alien_cache
**alc_ptr
)
895 static void __drain_alien_cache(struct kmem_cache
*cachep
,
896 struct array_cache
*ac
, int node
,
897 struct list_head
*list
)
899 struct kmem_cache_node
*n
= get_node(cachep
, node
);
902 spin_lock(&n
->list_lock
);
904 * Stuff objects into the remote nodes shared array first.
905 * That way we could avoid the overhead of putting the objects
906 * into the free lists and getting them back later.
909 transfer_objects(n
->shared
, ac
, ac
->limit
);
911 free_block(cachep
, ac
->entry
, ac
->avail
, node
, list
);
913 spin_unlock(&n
->list_lock
);
918 * Called from cache_reap() to regularly drain alien caches round robin.
920 static void reap_alien(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
)
922 int node
= __this_cpu_read(slab_reap_node
);
925 struct alien_cache
*alc
= n
->alien
[node
];
926 struct array_cache
*ac
;
930 if (ac
->avail
&& spin_trylock_irq(&alc
->lock
)) {
933 __drain_alien_cache(cachep
, ac
, node
, &list
);
934 spin_unlock_irq(&alc
->lock
);
935 slabs_destroy(cachep
, &list
);
941 static void drain_alien_cache(struct kmem_cache
*cachep
,
942 struct alien_cache
**alien
)
945 struct alien_cache
*alc
;
946 struct array_cache
*ac
;
949 for_each_online_node(i
) {
955 spin_lock_irqsave(&alc
->lock
, flags
);
956 __drain_alien_cache(cachep
, ac
, i
, &list
);
957 spin_unlock_irqrestore(&alc
->lock
, flags
);
958 slabs_destroy(cachep
, &list
);
963 static int __cache_free_alien(struct kmem_cache
*cachep
, void *objp
,
964 int node
, int page_node
)
966 struct kmem_cache_node
*n
;
967 struct alien_cache
*alien
= NULL
;
968 struct array_cache
*ac
;
971 n
= get_node(cachep
, node
);
972 STATS_INC_NODEFREES(cachep
);
973 if (n
->alien
&& n
->alien
[page_node
]) {
974 alien
= n
->alien
[page_node
];
976 spin_lock(&alien
->lock
);
977 if (unlikely(ac
->avail
== ac
->limit
)) {
978 STATS_INC_ACOVERFLOW(cachep
);
979 __drain_alien_cache(cachep
, ac
, page_node
, &list
);
981 ac_put_obj(cachep
, ac
, objp
);
982 spin_unlock(&alien
->lock
);
983 slabs_destroy(cachep
, &list
);
985 n
= get_node(cachep
, page_node
);
986 spin_lock(&n
->list_lock
);
987 free_block(cachep
, &objp
, 1, page_node
, &list
);
988 spin_unlock(&n
->list_lock
);
989 slabs_destroy(cachep
, &list
);
994 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
996 int page_node
= page_to_nid(virt_to_page(objp
));
997 int node
= numa_mem_id();
999 * Make sure we are not freeing a object from another node to the array
1000 * cache on this cpu.
1002 if (likely(node
== page_node
))
1005 return __cache_free_alien(cachep
, objp
, node
, page_node
);
1009 * Construct gfp mask to allocate from a specific node but do not direct reclaim
1010 * or warn about failures. kswapd may still wake to reclaim in the background.
1012 static inline gfp_t
gfp_exact_node(gfp_t flags
)
1014 return (flags
| __GFP_THISNODE
| __GFP_NOWARN
) & ~__GFP_DIRECT_RECLAIM
;
1019 * Allocates and initializes node for a node on each slab cache, used for
1020 * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
1021 * will be allocated off-node since memory is not yet online for the new node.
1022 * When hotplugging memory or a cpu, existing node are not replaced if
1025 * Must hold slab_mutex.
1027 static int init_cache_node_node(int node
)
1029 struct kmem_cache
*cachep
;
1030 struct kmem_cache_node
*n
;
1031 const size_t memsize
= sizeof(struct kmem_cache_node
);
1033 list_for_each_entry(cachep
, &slab_caches
, list
) {
1035 * Set up the kmem_cache_node for cpu before we can
1036 * begin anything. Make sure some other cpu on this
1037 * node has not already allocated this
1039 n
= get_node(cachep
, node
);
1041 n
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
1044 kmem_cache_node_init(n
);
1045 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
+
1046 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
1049 * The kmem_cache_nodes don't come and go as CPUs
1050 * come and go. slab_mutex is sufficient
1053 cachep
->node
[node
] = n
;
1056 spin_lock_irq(&n
->list_lock
);
1058 (1 + nr_cpus_node(node
)) *
1059 cachep
->batchcount
+ cachep
->num
;
1060 spin_unlock_irq(&n
->list_lock
);
1065 static inline int slabs_tofree(struct kmem_cache
*cachep
,
1066 struct kmem_cache_node
*n
)
1068 return (n
->free_objects
+ cachep
->num
- 1) / cachep
->num
;
1071 static void cpuup_canceled(long cpu
)
1073 struct kmem_cache
*cachep
;
1074 struct kmem_cache_node
*n
= NULL
;
1075 int node
= cpu_to_mem(cpu
);
1076 const struct cpumask
*mask
= cpumask_of_node(node
);
1078 list_for_each_entry(cachep
, &slab_caches
, list
) {
1079 struct array_cache
*nc
;
1080 struct array_cache
*shared
;
1081 struct alien_cache
**alien
;
1084 n
= get_node(cachep
, node
);
1088 spin_lock_irq(&n
->list_lock
);
1090 /* Free limit for this kmem_cache_node */
1091 n
->free_limit
-= cachep
->batchcount
;
1093 /* cpu is dead; no one can alloc from it. */
1094 nc
= per_cpu_ptr(cachep
->cpu_cache
, cpu
);
1096 free_block(cachep
, nc
->entry
, nc
->avail
, node
, &list
);
1100 if (!cpumask_empty(mask
)) {
1101 spin_unlock_irq(&n
->list_lock
);
1107 free_block(cachep
, shared
->entry
,
1108 shared
->avail
, node
, &list
);
1115 spin_unlock_irq(&n
->list_lock
);
1119 drain_alien_cache(cachep
, alien
);
1120 free_alien_cache(alien
);
1124 slabs_destroy(cachep
, &list
);
1127 * In the previous loop, all the objects were freed to
1128 * the respective cache's slabs, now we can go ahead and
1129 * shrink each nodelist to its limit.
1131 list_for_each_entry(cachep
, &slab_caches
, list
) {
1132 n
= get_node(cachep
, node
);
1135 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
1139 static int cpuup_prepare(long cpu
)
1141 struct kmem_cache
*cachep
;
1142 struct kmem_cache_node
*n
= NULL
;
1143 int node
= cpu_to_mem(cpu
);
1147 * We need to do this right in the beginning since
1148 * alloc_arraycache's are going to use this list.
1149 * kmalloc_node allows us to add the slab to the right
1150 * kmem_cache_node and not this cpu's kmem_cache_node
1152 err
= init_cache_node_node(node
);
1157 * Now we can go ahead with allocating the shared arrays and
1160 list_for_each_entry(cachep
, &slab_caches
, list
) {
1161 struct array_cache
*shared
= NULL
;
1162 struct alien_cache
**alien
= NULL
;
1164 if (cachep
->shared
) {
1165 shared
= alloc_arraycache(node
,
1166 cachep
->shared
* cachep
->batchcount
,
1167 0xbaadf00d, GFP_KERNEL
);
1171 if (use_alien_caches
) {
1172 alien
= alloc_alien_cache(node
, cachep
->limit
, GFP_KERNEL
);
1178 n
= get_node(cachep
, node
);
1181 spin_lock_irq(&n
->list_lock
);
1184 * We are serialised from CPU_DEAD or
1185 * CPU_UP_CANCELLED by the cpucontrol lock
1196 spin_unlock_irq(&n
->list_lock
);
1198 free_alien_cache(alien
);
1203 cpuup_canceled(cpu
);
1207 static int cpuup_callback(struct notifier_block
*nfb
,
1208 unsigned long action
, void *hcpu
)
1210 long cpu
= (long)hcpu
;
1214 case CPU_UP_PREPARE
:
1215 case CPU_UP_PREPARE_FROZEN
:
1216 mutex_lock(&slab_mutex
);
1217 err
= cpuup_prepare(cpu
);
1218 mutex_unlock(&slab_mutex
);
1221 case CPU_ONLINE_FROZEN
:
1222 start_cpu_timer(cpu
);
1224 #ifdef CONFIG_HOTPLUG_CPU
1225 case CPU_DOWN_PREPARE
:
1226 case CPU_DOWN_PREPARE_FROZEN
:
1228 * Shutdown cache reaper. Note that the slab_mutex is
1229 * held so that if cache_reap() is invoked it cannot do
1230 * anything expensive but will only modify reap_work
1231 * and reschedule the timer.
1233 cancel_delayed_work_sync(&per_cpu(slab_reap_work
, cpu
));
1234 /* Now the cache_reaper is guaranteed to be not running. */
1235 per_cpu(slab_reap_work
, cpu
).work
.func
= NULL
;
1237 case CPU_DOWN_FAILED
:
1238 case CPU_DOWN_FAILED_FROZEN
:
1239 start_cpu_timer(cpu
);
1242 case CPU_DEAD_FROZEN
:
1244 * Even if all the cpus of a node are down, we don't free the
1245 * kmem_cache_node of any cache. This to avoid a race between
1246 * cpu_down, and a kmalloc allocation from another cpu for
1247 * memory from the node of the cpu going down. The node
1248 * structure is usually allocated from kmem_cache_create() and
1249 * gets destroyed at kmem_cache_destroy().
1253 case CPU_UP_CANCELED
:
1254 case CPU_UP_CANCELED_FROZEN
:
1255 mutex_lock(&slab_mutex
);
1256 cpuup_canceled(cpu
);
1257 mutex_unlock(&slab_mutex
);
1260 return notifier_from_errno(err
);
1263 static struct notifier_block cpucache_notifier
= {
1264 &cpuup_callback
, NULL
, 0
1267 #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
1269 * Drains freelist for a node on each slab cache, used for memory hot-remove.
1270 * Returns -EBUSY if all objects cannot be drained so that the node is not
1273 * Must hold slab_mutex.
1275 static int __meminit
drain_cache_node_node(int node
)
1277 struct kmem_cache
*cachep
;
1280 list_for_each_entry(cachep
, &slab_caches
, list
) {
1281 struct kmem_cache_node
*n
;
1283 n
= get_node(cachep
, node
);
1287 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
1289 if (!list_empty(&n
->slabs_full
) ||
1290 !list_empty(&n
->slabs_partial
)) {
1298 static int __meminit
slab_memory_callback(struct notifier_block
*self
,
1299 unsigned long action
, void *arg
)
1301 struct memory_notify
*mnb
= arg
;
1305 nid
= mnb
->status_change_nid
;
1310 case MEM_GOING_ONLINE
:
1311 mutex_lock(&slab_mutex
);
1312 ret
= init_cache_node_node(nid
);
1313 mutex_unlock(&slab_mutex
);
1315 case MEM_GOING_OFFLINE
:
1316 mutex_lock(&slab_mutex
);
1317 ret
= drain_cache_node_node(nid
);
1318 mutex_unlock(&slab_mutex
);
1322 case MEM_CANCEL_ONLINE
:
1323 case MEM_CANCEL_OFFLINE
:
1327 return notifier_from_errno(ret
);
1329 #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
1332 * swap the static kmem_cache_node with kmalloced memory
1334 static void __init
init_list(struct kmem_cache
*cachep
, struct kmem_cache_node
*list
,
1337 struct kmem_cache_node
*ptr
;
1339 ptr
= kmalloc_node(sizeof(struct kmem_cache_node
), GFP_NOWAIT
, nodeid
);
1342 memcpy(ptr
, list
, sizeof(struct kmem_cache_node
));
1344 * Do not assume that spinlocks can be initialized via memcpy:
1346 spin_lock_init(&ptr
->list_lock
);
1348 MAKE_ALL_LISTS(cachep
, ptr
, nodeid
);
1349 cachep
->node
[nodeid
] = ptr
;
1353 * For setting up all the kmem_cache_node for cache whose buffer_size is same as
1354 * size of kmem_cache_node.
1356 static void __init
set_up_node(struct kmem_cache
*cachep
, int index
)
1360 for_each_online_node(node
) {
1361 cachep
->node
[node
] = &init_kmem_cache_node
[index
+ node
];
1362 cachep
->node
[node
]->next_reap
= jiffies
+
1364 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
1369 * Initialisation. Called after the page allocator have been initialised and
1370 * before smp_init().
1372 void __init
kmem_cache_init(void)
1376 BUILD_BUG_ON(sizeof(((struct page
*)NULL
)->lru
) <
1377 sizeof(struct rcu_head
));
1378 kmem_cache
= &kmem_cache_boot
;
1380 if (num_possible_nodes() == 1)
1381 use_alien_caches
= 0;
1383 for (i
= 0; i
< NUM_INIT_LISTS
; i
++)
1384 kmem_cache_node_init(&init_kmem_cache_node
[i
]);
1387 * Fragmentation resistance on low memory - only use bigger
1388 * page orders on machines with more than 32MB of memory if
1389 * not overridden on the command line.
1391 if (!slab_max_order_set
&& totalram_pages
> (32 << 20) >> PAGE_SHIFT
)
1392 slab_max_order
= SLAB_MAX_ORDER_HI
;
1394 /* Bootstrap is tricky, because several objects are allocated
1395 * from caches that do not exist yet:
1396 * 1) initialize the kmem_cache cache: it contains the struct
1397 * kmem_cache structures of all caches, except kmem_cache itself:
1398 * kmem_cache is statically allocated.
1399 * Initially an __init data area is used for the head array and the
1400 * kmem_cache_node structures, it's replaced with a kmalloc allocated
1401 * array at the end of the bootstrap.
1402 * 2) Create the first kmalloc cache.
1403 * The struct kmem_cache for the new cache is allocated normally.
1404 * An __init data area is used for the head array.
1405 * 3) Create the remaining kmalloc caches, with minimally sized
1407 * 4) Replace the __init data head arrays for kmem_cache and the first
1408 * kmalloc cache with kmalloc allocated arrays.
1409 * 5) Replace the __init data for kmem_cache_node for kmem_cache and
1410 * the other cache's with kmalloc allocated memory.
1411 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1414 /* 1) create the kmem_cache */
1417 * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
1419 create_boot_cache(kmem_cache
, "kmem_cache",
1420 offsetof(struct kmem_cache
, node
) +
1421 nr_node_ids
* sizeof(struct kmem_cache_node
*),
1422 SLAB_HWCACHE_ALIGN
);
1423 list_add(&kmem_cache
->list
, &slab_caches
);
1424 slab_state
= PARTIAL
;
1427 * Initialize the caches that provide memory for the kmem_cache_node
1428 * structures first. Without this, further allocations will bug.
1430 kmalloc_caches
[INDEX_NODE
] = create_kmalloc_cache("kmalloc-node",
1431 kmalloc_size(INDEX_NODE
), ARCH_KMALLOC_FLAGS
);
1432 slab_state
= PARTIAL_NODE
;
1433 setup_kmalloc_cache_index_table();
1435 slab_early_init
= 0;
1437 /* 5) Replace the bootstrap kmem_cache_node */
1441 for_each_online_node(nid
) {
1442 init_list(kmem_cache
, &init_kmem_cache_node
[CACHE_CACHE
+ nid
], nid
);
1444 init_list(kmalloc_caches
[INDEX_NODE
],
1445 &init_kmem_cache_node
[SIZE_NODE
+ nid
], nid
);
1449 create_kmalloc_caches(ARCH_KMALLOC_FLAGS
);
1452 void __init
kmem_cache_init_late(void)
1454 struct kmem_cache
*cachep
;
1458 /* 6) resize the head arrays to their final sizes */
1459 mutex_lock(&slab_mutex
);
1460 list_for_each_entry(cachep
, &slab_caches
, list
)
1461 if (enable_cpucache(cachep
, GFP_NOWAIT
))
1463 mutex_unlock(&slab_mutex
);
1469 * Register a cpu startup notifier callback that initializes
1470 * cpu_cache_get for all new cpus
1472 register_cpu_notifier(&cpucache_notifier
);
1476 * Register a memory hotplug callback that initializes and frees
1479 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
1483 * The reap timers are started later, with a module init call: That part
1484 * of the kernel is not yet operational.
1488 static int __init
cpucache_init(void)
1493 * Register the timers that return unneeded pages to the page allocator
1495 for_each_online_cpu(cpu
)
1496 start_cpu_timer(cpu
);
1502 __initcall(cpucache_init
);
1504 static noinline
void
1505 slab_out_of_memory(struct kmem_cache
*cachep
, gfp_t gfpflags
, int nodeid
)
1508 struct kmem_cache_node
*n
;
1510 unsigned long flags
;
1512 static DEFINE_RATELIMIT_STATE(slab_oom_rs
, DEFAULT_RATELIMIT_INTERVAL
,
1513 DEFAULT_RATELIMIT_BURST
);
1515 if ((gfpflags
& __GFP_NOWARN
) || !__ratelimit(&slab_oom_rs
))
1519 "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n",
1521 printk(KERN_WARNING
" cache: %s, object size: %d, order: %d\n",
1522 cachep
->name
, cachep
->size
, cachep
->gfporder
);
1524 for_each_kmem_cache_node(cachep
, node
, n
) {
1525 unsigned long active_objs
= 0, num_objs
= 0, free_objects
= 0;
1526 unsigned long active_slabs
= 0, num_slabs
= 0;
1528 spin_lock_irqsave(&n
->list_lock
, flags
);
1529 list_for_each_entry(page
, &n
->slabs_full
, lru
) {
1530 active_objs
+= cachep
->num
;
1533 list_for_each_entry(page
, &n
->slabs_partial
, lru
) {
1534 active_objs
+= page
->active
;
1537 list_for_each_entry(page
, &n
->slabs_free
, lru
)
1540 free_objects
+= n
->free_objects
;
1541 spin_unlock_irqrestore(&n
->list_lock
, flags
);
1543 num_slabs
+= active_slabs
;
1544 num_objs
= num_slabs
* cachep
->num
;
1546 " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",
1547 node
, active_slabs
, num_slabs
, active_objs
, num_objs
,
1554 * Interface to system's page allocator. No need to hold the
1555 * kmem_cache_node ->list_lock.
1557 * If we requested dmaable memory, we will get it. Even if we
1558 * did not request dmaable memory, we might get it, but that
1559 * would be relatively rare and ignorable.
1561 static struct page
*kmem_getpages(struct kmem_cache
*cachep
, gfp_t flags
,
1567 flags
|= cachep
->allocflags
;
1568 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1569 flags
|= __GFP_RECLAIMABLE
;
1571 page
= __alloc_pages_node(nodeid
, flags
| __GFP_NOTRACK
, cachep
->gfporder
);
1573 slab_out_of_memory(cachep
, flags
, nodeid
);
1577 if (memcg_charge_slab(page
, flags
, cachep
->gfporder
, cachep
)) {
1578 __free_pages(page
, cachep
->gfporder
);
1582 /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
1583 if (page_is_pfmemalloc(page
))
1584 pfmemalloc_active
= true;
1586 nr_pages
= (1 << cachep
->gfporder
);
1587 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1588 add_zone_page_state(page_zone(page
),
1589 NR_SLAB_RECLAIMABLE
, nr_pages
);
1591 add_zone_page_state(page_zone(page
),
1592 NR_SLAB_UNRECLAIMABLE
, nr_pages
);
1593 __SetPageSlab(page
);
1594 if (page_is_pfmemalloc(page
))
1595 SetPageSlabPfmemalloc(page
);
1597 if (kmemcheck_enabled
&& !(cachep
->flags
& SLAB_NOTRACK
)) {
1598 kmemcheck_alloc_shadow(page
, cachep
->gfporder
, flags
, nodeid
);
1601 kmemcheck_mark_uninitialized_pages(page
, nr_pages
);
1603 kmemcheck_mark_unallocated_pages(page
, nr_pages
);
1610 * Interface to system's page release.
1612 static void kmem_freepages(struct kmem_cache
*cachep
, struct page
*page
)
1614 const unsigned long nr_freed
= (1 << cachep
->gfporder
);
1616 kmemcheck_free_shadow(page
, cachep
->gfporder
);
1618 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1619 sub_zone_page_state(page_zone(page
),
1620 NR_SLAB_RECLAIMABLE
, nr_freed
);
1622 sub_zone_page_state(page_zone(page
),
1623 NR_SLAB_UNRECLAIMABLE
, nr_freed
);
1625 BUG_ON(!PageSlab(page
));
1626 __ClearPageSlabPfmemalloc(page
);
1627 __ClearPageSlab(page
);
1628 page_mapcount_reset(page
);
1629 page
->mapping
= NULL
;
1631 if (current
->reclaim_state
)
1632 current
->reclaim_state
->reclaimed_slab
+= nr_freed
;
1633 __free_kmem_pages(page
, cachep
->gfporder
);
1636 static void kmem_rcu_free(struct rcu_head
*head
)
1638 struct kmem_cache
*cachep
;
1641 page
= container_of(head
, struct page
, rcu_head
);
1642 cachep
= page
->slab_cache
;
1644 kmem_freepages(cachep
, page
);
1648 static bool is_debug_pagealloc_cache(struct kmem_cache
*cachep
)
1650 if (debug_pagealloc_enabled() && OFF_SLAB(cachep
) &&
1651 (cachep
->size
% PAGE_SIZE
) == 0)
1657 #ifdef CONFIG_DEBUG_PAGEALLOC
1658 static void store_stackinfo(struct kmem_cache
*cachep
, unsigned long *addr
,
1659 unsigned long caller
)
1661 int size
= cachep
->object_size
;
1663 addr
= (unsigned long *)&((char *)addr
)[obj_offset(cachep
)];
1665 if (size
< 5 * sizeof(unsigned long))
1668 *addr
++ = 0x12345678;
1670 *addr
++ = smp_processor_id();
1671 size
-= 3 * sizeof(unsigned long);
1673 unsigned long *sptr
= &caller
;
1674 unsigned long svalue
;
1676 while (!kstack_end(sptr
)) {
1678 if (kernel_text_address(svalue
)) {
1680 size
-= sizeof(unsigned long);
1681 if (size
<= sizeof(unsigned long))
1687 *addr
++ = 0x87654321;
1690 static void slab_kernel_map(struct kmem_cache
*cachep
, void *objp
,
1691 int map
, unsigned long caller
)
1693 if (!is_debug_pagealloc_cache(cachep
))
1697 store_stackinfo(cachep
, objp
, caller
);
1699 kernel_map_pages(virt_to_page(objp
), cachep
->size
/ PAGE_SIZE
, map
);
1703 static inline void slab_kernel_map(struct kmem_cache
*cachep
, void *objp
,
1704 int map
, unsigned long caller
) {}
1708 static void poison_obj(struct kmem_cache
*cachep
, void *addr
, unsigned char val
)
1710 int size
= cachep
->object_size
;
1711 addr
= &((char *)addr
)[obj_offset(cachep
)];
1713 memset(addr
, val
, size
);
1714 *(unsigned char *)(addr
+ size
- 1) = POISON_END
;
1717 static void dump_line(char *data
, int offset
, int limit
)
1720 unsigned char error
= 0;
1723 printk(KERN_ERR
"%03x: ", offset
);
1724 for (i
= 0; i
< limit
; i
++) {
1725 if (data
[offset
+ i
] != POISON_FREE
) {
1726 error
= data
[offset
+ i
];
1730 print_hex_dump(KERN_CONT
, "", 0, 16, 1,
1731 &data
[offset
], limit
, 1);
1733 if (bad_count
== 1) {
1734 error
^= POISON_FREE
;
1735 if (!(error
& (error
- 1))) {
1736 printk(KERN_ERR
"Single bit error detected. Probably "
1739 printk(KERN_ERR
"Run memtest86+ or a similar memory "
1742 printk(KERN_ERR
"Run a memory test tool.\n");
1751 static void print_objinfo(struct kmem_cache
*cachep
, void *objp
, int lines
)
1756 if (cachep
->flags
& SLAB_RED_ZONE
) {
1757 printk(KERN_ERR
"Redzone: 0x%llx/0x%llx.\n",
1758 *dbg_redzone1(cachep
, objp
),
1759 *dbg_redzone2(cachep
, objp
));
1762 if (cachep
->flags
& SLAB_STORE_USER
) {
1763 printk(KERN_ERR
"Last user: [<%p>](%pSR)\n",
1764 *dbg_userword(cachep
, objp
),
1765 *dbg_userword(cachep
, objp
));
1767 realobj
= (char *)objp
+ obj_offset(cachep
);
1768 size
= cachep
->object_size
;
1769 for (i
= 0; i
< size
&& lines
; i
+= 16, lines
--) {
1772 if (i
+ limit
> size
)
1774 dump_line(realobj
, i
, limit
);
1778 static void check_poison_obj(struct kmem_cache
*cachep
, void *objp
)
1784 if (is_debug_pagealloc_cache(cachep
))
1787 realobj
= (char *)objp
+ obj_offset(cachep
);
1788 size
= cachep
->object_size
;
1790 for (i
= 0; i
< size
; i
++) {
1791 char exp
= POISON_FREE
;
1794 if (realobj
[i
] != exp
) {
1800 "Slab corruption (%s): %s start=%p, len=%d\n",
1801 print_tainted(), cachep
->name
, realobj
, size
);
1802 print_objinfo(cachep
, objp
, 0);
1804 /* Hexdump the affected line */
1807 if (i
+ limit
> size
)
1809 dump_line(realobj
, i
, limit
);
1812 /* Limit to 5 lines */
1818 /* Print some data about the neighboring objects, if they
1821 struct page
*page
= virt_to_head_page(objp
);
1824 objnr
= obj_to_index(cachep
, page
, objp
);
1826 objp
= index_to_obj(cachep
, page
, objnr
- 1);
1827 realobj
= (char *)objp
+ obj_offset(cachep
);
1828 printk(KERN_ERR
"Prev obj: start=%p, len=%d\n",
1830 print_objinfo(cachep
, objp
, 2);
1832 if (objnr
+ 1 < cachep
->num
) {
1833 objp
= index_to_obj(cachep
, page
, objnr
+ 1);
1834 realobj
= (char *)objp
+ obj_offset(cachep
);
1835 printk(KERN_ERR
"Next obj: start=%p, len=%d\n",
1837 print_objinfo(cachep
, objp
, 2);
1844 static void slab_destroy_debugcheck(struct kmem_cache
*cachep
,
1848 for (i
= 0; i
< cachep
->num
; i
++) {
1849 void *objp
= index_to_obj(cachep
, page
, i
);
1851 if (cachep
->flags
& SLAB_POISON
) {
1852 check_poison_obj(cachep
, objp
);
1853 slab_kernel_map(cachep
, objp
, 1, 0);
1855 if (cachep
->flags
& SLAB_RED_ZONE
) {
1856 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
1857 slab_error(cachep
, "start of a freed object "
1859 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
1860 slab_error(cachep
, "end of a freed object "
1866 static void slab_destroy_debugcheck(struct kmem_cache
*cachep
,
1873 * slab_destroy - destroy and release all objects in a slab
1874 * @cachep: cache pointer being destroyed
1875 * @page: page pointer being destroyed
1877 * Destroy all the objs in a slab page, and release the mem back to the system.
1878 * Before calling the slab page must have been unlinked from the cache. The
1879 * kmem_cache_node ->list_lock is not held/needed.
1881 static void slab_destroy(struct kmem_cache
*cachep
, struct page
*page
)
1885 freelist
= page
->freelist
;
1886 slab_destroy_debugcheck(cachep
, page
);
1887 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
))
1888 call_rcu(&page
->rcu_head
, kmem_rcu_free
);
1890 kmem_freepages(cachep
, page
);
1893 * From now on, we don't use freelist
1894 * although actual page can be freed in rcu context
1896 if (OFF_SLAB(cachep
))
1897 kmem_cache_free(cachep
->freelist_cache
, freelist
);
1900 static void slabs_destroy(struct kmem_cache
*cachep
, struct list_head
*list
)
1902 struct page
*page
, *n
;
1904 list_for_each_entry_safe(page
, n
, list
, lru
) {
1905 list_del(&page
->lru
);
1906 slab_destroy(cachep
, page
);
1911 * calculate_slab_order - calculate size (page order) of slabs
1912 * @cachep: pointer to the cache that is being created
1913 * @size: size of objects to be created in this cache.
1914 * @align: required alignment for the objects.
1915 * @flags: slab allocation flags
1917 * Also calculates the number of objects per slab.
1919 * This could be made much more intelligent. For now, try to avoid using
1920 * high order pages for slabs. When the gfp() functions are more friendly
1921 * towards high-order requests, this should be changed.
1923 static size_t calculate_slab_order(struct kmem_cache
*cachep
,
1924 size_t size
, size_t align
, unsigned long flags
)
1926 unsigned long offslab_limit
;
1927 size_t left_over
= 0;
1930 for (gfporder
= 0; gfporder
<= KMALLOC_MAX_ORDER
; gfporder
++) {
1934 cache_estimate(gfporder
, size
, align
, flags
, &remainder
, &num
);
1938 /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
1939 if (num
> SLAB_OBJ_MAX_NUM
)
1942 if (flags
& CFLGS_OFF_SLAB
) {
1944 * Max number of objs-per-slab for caches which
1945 * use off-slab slabs. Needed to avoid a possible
1946 * looping condition in cache_grow().
1948 offslab_limit
= size
;
1949 offslab_limit
/= sizeof(freelist_idx_t
);
1951 if (num
> offslab_limit
)
1955 /* Found something acceptable - save it away */
1957 cachep
->gfporder
= gfporder
;
1958 left_over
= remainder
;
1961 * A VFS-reclaimable slab tends to have most allocations
1962 * as GFP_NOFS and we really don't want to have to be allocating
1963 * higher-order pages when we are unable to shrink dcache.
1965 if (flags
& SLAB_RECLAIM_ACCOUNT
)
1969 * Large number of objects is good, but very large slabs are
1970 * currently bad for the gfp()s.
1972 if (gfporder
>= slab_max_order
)
1976 * Acceptable internal fragmentation?
1978 if (left_over
* 8 <= (PAGE_SIZE
<< gfporder
))
1984 static struct array_cache __percpu
*alloc_kmem_cache_cpus(
1985 struct kmem_cache
*cachep
, int entries
, int batchcount
)
1989 struct array_cache __percpu
*cpu_cache
;
1991 size
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
1992 cpu_cache
= __alloc_percpu(size
, sizeof(void *));
1997 for_each_possible_cpu(cpu
) {
1998 init_arraycache(per_cpu_ptr(cpu_cache
, cpu
),
1999 entries
, batchcount
);
2005 static int __init_refok
setup_cpu_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
2007 if (slab_state
>= FULL
)
2008 return enable_cpucache(cachep
, gfp
);
2010 cachep
->cpu_cache
= alloc_kmem_cache_cpus(cachep
, 1, 1);
2011 if (!cachep
->cpu_cache
)
2014 if (slab_state
== DOWN
) {
2015 /* Creation of first cache (kmem_cache). */
2016 set_up_node(kmem_cache
, CACHE_CACHE
);
2017 } else if (slab_state
== PARTIAL
) {
2018 /* For kmem_cache_node */
2019 set_up_node(cachep
, SIZE_NODE
);
2023 for_each_online_node(node
) {
2024 cachep
->node
[node
] = kmalloc_node(
2025 sizeof(struct kmem_cache_node
), gfp
, node
);
2026 BUG_ON(!cachep
->node
[node
]);
2027 kmem_cache_node_init(cachep
->node
[node
]);
2031 cachep
->node
[numa_mem_id()]->next_reap
=
2032 jiffies
+ REAPTIMEOUT_NODE
+
2033 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
2035 cpu_cache_get(cachep
)->avail
= 0;
2036 cpu_cache_get(cachep
)->limit
= BOOT_CPUCACHE_ENTRIES
;
2037 cpu_cache_get(cachep
)->batchcount
= 1;
2038 cpu_cache_get(cachep
)->touched
= 0;
2039 cachep
->batchcount
= 1;
2040 cachep
->limit
= BOOT_CPUCACHE_ENTRIES
;
2044 unsigned long kmem_cache_flags(unsigned long object_size
,
2045 unsigned long flags
, const char *name
,
2046 void (*ctor
)(void *))
2052 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
2053 unsigned long flags
, void (*ctor
)(void *))
2055 struct kmem_cache
*cachep
;
2057 cachep
= find_mergeable(size
, align
, flags
, name
, ctor
);
2062 * Adjust the object sizes so that we clear
2063 * the complete object on kzalloc.
2065 cachep
->object_size
= max_t(int, cachep
->object_size
, size
);
2071 * __kmem_cache_create - Create a cache.
2072 * @cachep: cache management descriptor
2073 * @flags: SLAB flags
2075 * Returns a ptr to the cache on success, NULL on failure.
2076 * Cannot be called within a int, but can be interrupted.
2077 * The @ctor is run when new pages are allocated by the cache.
2081 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2082 * to catch references to uninitialised memory.
2084 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2085 * for buffer overruns.
2087 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2088 * cacheline. This can be beneficial if you're counting cycles as closely
2092 __kmem_cache_create (struct kmem_cache
*cachep
, unsigned long flags
)
2094 size_t left_over
, freelist_size
;
2095 size_t ralign
= BYTES_PER_WORD
;
2098 size_t size
= cachep
->size
;
2103 * Enable redzoning and last user accounting, except for caches with
2104 * large objects, if the increased size would increase the object size
2105 * above the next power of two: caches with object sizes just above a
2106 * power of two have a significant amount of internal fragmentation.
2108 if (size
< 4096 || fls(size
- 1) == fls(size
-1 + REDZONE_ALIGN
+
2109 2 * sizeof(unsigned long long)))
2110 flags
|= SLAB_RED_ZONE
| SLAB_STORE_USER
;
2111 if (!(flags
& SLAB_DESTROY_BY_RCU
))
2112 flags
|= SLAB_POISON
;
2117 * Check that size is in terms of words. This is needed to avoid
2118 * unaligned accesses for some archs when redzoning is used, and makes
2119 * sure any on-slab bufctl's are also correctly aligned.
2121 if (size
& (BYTES_PER_WORD
- 1)) {
2122 size
+= (BYTES_PER_WORD
- 1);
2123 size
&= ~(BYTES_PER_WORD
- 1);
2126 if (flags
& SLAB_RED_ZONE
) {
2127 ralign
= REDZONE_ALIGN
;
2128 /* If redzoning, ensure that the second redzone is suitably
2129 * aligned, by adjusting the object size accordingly. */
2130 size
+= REDZONE_ALIGN
- 1;
2131 size
&= ~(REDZONE_ALIGN
- 1);
2134 /* 3) caller mandated alignment */
2135 if (ralign
< cachep
->align
) {
2136 ralign
= cachep
->align
;
2138 /* disable debug if necessary */
2139 if (ralign
> __alignof__(unsigned long long))
2140 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2144 cachep
->align
= ralign
;
2146 if (slab_is_available())
2154 * Both debugging options require word-alignment which is calculated
2157 if (flags
& SLAB_RED_ZONE
) {
2158 /* add space for red zone words */
2159 cachep
->obj_offset
+= sizeof(unsigned long long);
2160 size
+= 2 * sizeof(unsigned long long);
2162 if (flags
& SLAB_STORE_USER
) {
2163 /* user store requires one word storage behind the end of
2164 * the real object. But if the second red zone needs to be
2165 * aligned to 64 bits, we must allow that much space.
2167 if (flags
& SLAB_RED_ZONE
)
2168 size
+= REDZONE_ALIGN
;
2170 size
+= BYTES_PER_WORD
;
2173 * To activate debug pagealloc, off-slab management is necessary
2174 * requirement. In early phase of initialization, small sized slab
2175 * doesn't get initialized so it would not be possible. So, we need
2176 * to check size >= 256. It guarantees that all necessary small
2177 * sized slab is initialized in current slab initialization sequence.
2179 if (debug_pagealloc_enabled() && (flags
& SLAB_POISON
) &&
2180 !slab_early_init
&& size
>= kmalloc_size(INDEX_NODE
) &&
2181 size
>= 256 && cachep
->object_size
> cache_line_size() &&
2182 ALIGN(size
, cachep
->align
) < PAGE_SIZE
) {
2183 cachep
->obj_offset
+= PAGE_SIZE
- ALIGN(size
, cachep
->align
);
2189 * Determine if the slab management is 'on' or 'off' slab.
2190 * (bootstrapping cannot cope with offslab caches so don't do
2191 * it too early on. Always use on-slab management when
2192 * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak)
2194 if (size
>= OFF_SLAB_MIN_SIZE
&& !slab_early_init
&&
2195 !(flags
& SLAB_NOLEAKTRACE
))
2197 * Size is large, assume best to place the slab management obj
2198 * off-slab (should allow better packing of objs).
2200 flags
|= CFLGS_OFF_SLAB
;
2202 size
= ALIGN(size
, cachep
->align
);
2204 * We should restrict the number of objects in a slab to implement
2205 * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
2207 if (FREELIST_BYTE_INDEX
&& size
< SLAB_OBJ_MIN_SIZE
)
2208 size
= ALIGN(SLAB_OBJ_MIN_SIZE
, cachep
->align
);
2210 left_over
= calculate_slab_order(cachep
, size
, cachep
->align
, flags
);
2215 freelist_size
= calculate_freelist_size(cachep
->num
, cachep
->align
);
2218 * If the slab has been placed off-slab, and we have enough space then
2219 * move it on-slab. This is at the expense of any extra colouring.
2221 if (flags
& CFLGS_OFF_SLAB
&& left_over
>= freelist_size
) {
2222 flags
&= ~CFLGS_OFF_SLAB
;
2223 left_over
-= freelist_size
;
2226 if (flags
& CFLGS_OFF_SLAB
) {
2227 /* really off slab. No need for manual alignment */
2228 freelist_size
= calculate_freelist_size(cachep
->num
, 0);
2231 cachep
->colour_off
= cache_line_size();
2232 /* Offset must be a multiple of the alignment. */
2233 if (cachep
->colour_off
< cachep
->align
)
2234 cachep
->colour_off
= cachep
->align
;
2235 cachep
->colour
= left_over
/ cachep
->colour_off
;
2236 cachep
->freelist_size
= freelist_size
;
2237 cachep
->flags
= flags
;
2238 cachep
->allocflags
= __GFP_COMP
;
2239 if (CONFIG_ZONE_DMA_FLAG
&& (flags
& SLAB_CACHE_DMA
))
2240 cachep
->allocflags
|= GFP_DMA
;
2241 cachep
->size
= size
;
2242 cachep
->reciprocal_buffer_size
= reciprocal_value(size
);
2246 * If we're going to use the generic kernel_map_pages()
2247 * poisoning, then it's going to smash the contents of
2248 * the redzone and userword anyhow, so switch them off.
2250 if (IS_ENABLED(CONFIG_PAGE_POISONING
) &&
2251 (cachep
->flags
& SLAB_POISON
) &&
2252 is_debug_pagealloc_cache(cachep
))
2253 cachep
->flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2256 if (OFF_SLAB(cachep
)) {
2257 cachep
->freelist_cache
= kmalloc_slab(freelist_size
, 0u);
2259 * This is a possibility for one of the kmalloc_{dma,}_caches.
2260 * But since we go off slab only for object size greater than
2261 * OFF_SLAB_MIN_SIZE, and kmalloc_{dma,}_caches get created
2262 * in ascending order,this should not happen at all.
2263 * But leave a BUG_ON for some lucky dude.
2265 BUG_ON(ZERO_OR_NULL_PTR(cachep
->freelist_cache
));
2268 err
= setup_cpu_cache(cachep
, gfp
);
2270 __kmem_cache_release(cachep
);
2278 static void check_irq_off(void)
2280 BUG_ON(!irqs_disabled());
2283 static void check_irq_on(void)
2285 BUG_ON(irqs_disabled());
2288 static void check_spinlock_acquired(struct kmem_cache
*cachep
)
2292 assert_spin_locked(&get_node(cachep
, numa_mem_id())->list_lock
);
2296 static void check_spinlock_acquired_node(struct kmem_cache
*cachep
, int node
)
2300 assert_spin_locked(&get_node(cachep
, node
)->list_lock
);
2305 #define check_irq_off() do { } while(0)
2306 #define check_irq_on() do { } while(0)
2307 #define check_spinlock_acquired(x) do { } while(0)
2308 #define check_spinlock_acquired_node(x, y) do { } while(0)
2311 static void drain_array(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
,
2312 struct array_cache
*ac
,
2313 int force
, int node
);
2315 static void do_drain(void *arg
)
2317 struct kmem_cache
*cachep
= arg
;
2318 struct array_cache
*ac
;
2319 int node
= numa_mem_id();
2320 struct kmem_cache_node
*n
;
2324 ac
= cpu_cache_get(cachep
);
2325 n
= get_node(cachep
, node
);
2326 spin_lock(&n
->list_lock
);
2327 free_block(cachep
, ac
->entry
, ac
->avail
, node
, &list
);
2328 spin_unlock(&n
->list_lock
);
2329 slabs_destroy(cachep
, &list
);
2333 static void drain_cpu_caches(struct kmem_cache
*cachep
)
2335 struct kmem_cache_node
*n
;
2338 on_each_cpu(do_drain
, cachep
, 1);
2340 for_each_kmem_cache_node(cachep
, node
, n
)
2342 drain_alien_cache(cachep
, n
->alien
);
2344 for_each_kmem_cache_node(cachep
, node
, n
)
2345 drain_array(cachep
, n
, n
->shared
, 1, node
);
2349 * Remove slabs from the list of free slabs.
2350 * Specify the number of slabs to drain in tofree.
2352 * Returns the actual number of slabs released.
2354 static int drain_freelist(struct kmem_cache
*cache
,
2355 struct kmem_cache_node
*n
, int tofree
)
2357 struct list_head
*p
;
2362 while (nr_freed
< tofree
&& !list_empty(&n
->slabs_free
)) {
2364 spin_lock_irq(&n
->list_lock
);
2365 p
= n
->slabs_free
.prev
;
2366 if (p
== &n
->slabs_free
) {
2367 spin_unlock_irq(&n
->list_lock
);
2371 page
= list_entry(p
, struct page
, lru
);
2372 list_del(&page
->lru
);
2374 * Safe to drop the lock. The slab is no longer linked
2377 n
->free_objects
-= cache
->num
;
2378 spin_unlock_irq(&n
->list_lock
);
2379 slab_destroy(cache
, page
);
2386 int __kmem_cache_shrink(struct kmem_cache
*cachep
, bool deactivate
)
2390 struct kmem_cache_node
*n
;
2392 drain_cpu_caches(cachep
);
2395 for_each_kmem_cache_node(cachep
, node
, n
) {
2396 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
2398 ret
+= !list_empty(&n
->slabs_full
) ||
2399 !list_empty(&n
->slabs_partial
);
2401 return (ret
? 1 : 0);
2404 int __kmem_cache_shutdown(struct kmem_cache
*cachep
)
2406 return __kmem_cache_shrink(cachep
, false);
2409 void __kmem_cache_release(struct kmem_cache
*cachep
)
2412 struct kmem_cache_node
*n
;
2414 free_percpu(cachep
->cpu_cache
);
2416 /* NUMA: free the node structures */
2417 for_each_kmem_cache_node(cachep
, i
, n
) {
2419 free_alien_cache(n
->alien
);
2421 cachep
->node
[i
] = NULL
;
2426 * Get the memory for a slab management obj.
2428 * For a slab cache when the slab descriptor is off-slab, the
2429 * slab descriptor can't come from the same cache which is being created,
2430 * Because if it is the case, that means we defer the creation of
2431 * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
2432 * And we eventually call down to __kmem_cache_create(), which
2433 * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
2434 * This is a "chicken-and-egg" problem.
2436 * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
2437 * which are all initialized during kmem_cache_init().
2439 static void *alloc_slabmgmt(struct kmem_cache
*cachep
,
2440 struct page
*page
, int colour_off
,
2441 gfp_t local_flags
, int nodeid
)
2444 void *addr
= page_address(page
);
2446 if (OFF_SLAB(cachep
)) {
2447 /* Slab management obj is off-slab. */
2448 freelist
= kmem_cache_alloc_node(cachep
->freelist_cache
,
2449 local_flags
, nodeid
);
2453 freelist
= addr
+ colour_off
;
2454 colour_off
+= cachep
->freelist_size
;
2457 page
->s_mem
= addr
+ colour_off
;
2461 static inline freelist_idx_t
get_free_obj(struct page
*page
, unsigned int idx
)
2463 return ((freelist_idx_t
*)page
->freelist
)[idx
];
2466 static inline void set_free_obj(struct page
*page
,
2467 unsigned int idx
, freelist_idx_t val
)
2469 ((freelist_idx_t
*)(page
->freelist
))[idx
] = val
;
2472 static void cache_init_objs(struct kmem_cache
*cachep
,
2477 for (i
= 0; i
< cachep
->num
; i
++) {
2478 void *objp
= index_to_obj(cachep
, page
, i
);
2480 if (cachep
->flags
& SLAB_STORE_USER
)
2481 *dbg_userword(cachep
, objp
) = NULL
;
2483 if (cachep
->flags
& SLAB_RED_ZONE
) {
2484 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2485 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2488 * Constructors are not allowed to allocate memory from the same
2489 * cache which they are a constructor for. Otherwise, deadlock.
2490 * They must also be threaded.
2492 if (cachep
->ctor
&& !(cachep
->flags
& SLAB_POISON
))
2493 cachep
->ctor(objp
+ obj_offset(cachep
));
2495 if (cachep
->flags
& SLAB_RED_ZONE
) {
2496 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
2497 slab_error(cachep
, "constructor overwrote the"
2498 " end of an object");
2499 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
2500 slab_error(cachep
, "constructor overwrote the"
2501 " start of an object");
2503 /* need to poison the objs? */
2504 if (cachep
->flags
& SLAB_POISON
) {
2505 poison_obj(cachep
, objp
, POISON_FREE
);
2506 slab_kernel_map(cachep
, objp
, 0, 0);
2512 set_free_obj(page
, i
, i
);
2516 static void kmem_flagcheck(struct kmem_cache
*cachep
, gfp_t flags
)
2518 if (CONFIG_ZONE_DMA_FLAG
) {
2519 if (flags
& GFP_DMA
)
2520 BUG_ON(!(cachep
->allocflags
& GFP_DMA
));
2522 BUG_ON(cachep
->allocflags
& GFP_DMA
);
2526 static void *slab_get_obj(struct kmem_cache
*cachep
, struct page
*page
)
2530 objp
= index_to_obj(cachep
, page
, get_free_obj(page
, page
->active
));
2534 if (cachep
->flags
& SLAB_STORE_USER
)
2535 set_store_user_dirty(cachep
);
2541 static void slab_put_obj(struct kmem_cache
*cachep
,
2542 struct page
*page
, void *objp
)
2544 unsigned int objnr
= obj_to_index(cachep
, page
, objp
);
2548 /* Verify double free bug */
2549 for (i
= page
->active
; i
< cachep
->num
; i
++) {
2550 if (get_free_obj(page
, i
) == objnr
) {
2551 printk(KERN_ERR
"slab: double free detected in cache "
2552 "'%s', objp %p\n", cachep
->name
, objp
);
2558 set_free_obj(page
, page
->active
, objnr
);
2562 * Map pages beginning at addr to the given cache and slab. This is required
2563 * for the slab allocator to be able to lookup the cache and slab of a
2564 * virtual address for kfree, ksize, and slab debugging.
2566 static void slab_map_pages(struct kmem_cache
*cache
, struct page
*page
,
2569 page
->slab_cache
= cache
;
2570 page
->freelist
= freelist
;
2574 * Grow (by 1) the number of slabs within a cache. This is called by
2575 * kmem_cache_alloc() when there are no active objs left in a cache.
2577 static int cache_grow(struct kmem_cache
*cachep
,
2578 gfp_t flags
, int nodeid
, struct page
*page
)
2583 struct kmem_cache_node
*n
;
2586 * Be lazy and only check for valid flags here, keeping it out of the
2587 * critical path in kmem_cache_alloc().
2589 if (unlikely(flags
& GFP_SLAB_BUG_MASK
)) {
2590 pr_emerg("gfp: %u\n", flags
& GFP_SLAB_BUG_MASK
);
2593 local_flags
= flags
& (GFP_CONSTRAINT_MASK
|GFP_RECLAIM_MASK
);
2595 /* Take the node list lock to change the colour_next on this node */
2597 n
= get_node(cachep
, nodeid
);
2598 spin_lock(&n
->list_lock
);
2600 /* Get colour for the slab, and cal the next value. */
2601 offset
= n
->colour_next
;
2603 if (n
->colour_next
>= cachep
->colour
)
2605 spin_unlock(&n
->list_lock
);
2607 offset
*= cachep
->colour_off
;
2609 if (gfpflags_allow_blocking(local_flags
))
2613 * The test for missing atomic flag is performed here, rather than
2614 * the more obvious place, simply to reduce the critical path length
2615 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2616 * will eventually be caught here (where it matters).
2618 kmem_flagcheck(cachep
, flags
);
2621 * Get mem for the objs. Attempt to allocate a physical page from
2625 page
= kmem_getpages(cachep
, local_flags
, nodeid
);
2629 /* Get slab management. */
2630 freelist
= alloc_slabmgmt(cachep
, page
, offset
,
2631 local_flags
& ~GFP_CONSTRAINT_MASK
, nodeid
);
2635 slab_map_pages(cachep
, page
, freelist
);
2637 cache_init_objs(cachep
, page
);
2639 if (gfpflags_allow_blocking(local_flags
))
2640 local_irq_disable();
2642 spin_lock(&n
->list_lock
);
2644 /* Make slab active. */
2645 list_add_tail(&page
->lru
, &(n
->slabs_free
));
2646 STATS_INC_GROWN(cachep
);
2647 n
->free_objects
+= cachep
->num
;
2648 spin_unlock(&n
->list_lock
);
2651 kmem_freepages(cachep
, page
);
2653 if (gfpflags_allow_blocking(local_flags
))
2654 local_irq_disable();
2661 * Perform extra freeing checks:
2662 * - detect bad pointers.
2663 * - POISON/RED_ZONE checking
2665 static void kfree_debugcheck(const void *objp
)
2667 if (!virt_addr_valid(objp
)) {
2668 printk(KERN_ERR
"kfree_debugcheck: out of range ptr %lxh.\n",
2669 (unsigned long)objp
);
2674 static inline void verify_redzone_free(struct kmem_cache
*cache
, void *obj
)
2676 unsigned long long redzone1
, redzone2
;
2678 redzone1
= *dbg_redzone1(cache
, obj
);
2679 redzone2
= *dbg_redzone2(cache
, obj
);
2684 if (redzone1
== RED_ACTIVE
&& redzone2
== RED_ACTIVE
)
2687 if (redzone1
== RED_INACTIVE
&& redzone2
== RED_INACTIVE
)
2688 slab_error(cache
, "double free detected");
2690 slab_error(cache
, "memory outside object was overwritten");
2692 printk(KERN_ERR
"%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
2693 obj
, redzone1
, redzone2
);
2696 static void *cache_free_debugcheck(struct kmem_cache
*cachep
, void *objp
,
2697 unsigned long caller
)
2702 BUG_ON(virt_to_cache(objp
) != cachep
);
2704 objp
-= obj_offset(cachep
);
2705 kfree_debugcheck(objp
);
2706 page
= virt_to_head_page(objp
);
2708 if (cachep
->flags
& SLAB_RED_ZONE
) {
2709 verify_redzone_free(cachep
, objp
);
2710 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2711 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2713 if (cachep
->flags
& SLAB_STORE_USER
) {
2714 set_store_user_dirty(cachep
);
2715 *dbg_userword(cachep
, objp
) = (void *)caller
;
2718 objnr
= obj_to_index(cachep
, page
, objp
);
2720 BUG_ON(objnr
>= cachep
->num
);
2721 BUG_ON(objp
!= index_to_obj(cachep
, page
, objnr
));
2723 if (cachep
->flags
& SLAB_POISON
) {
2724 poison_obj(cachep
, objp
, POISON_FREE
);
2725 slab_kernel_map(cachep
, objp
, 0, caller
);
2731 #define kfree_debugcheck(x) do { } while(0)
2732 #define cache_free_debugcheck(x,objp,z) (objp)
2735 static struct page
*get_first_slab(struct kmem_cache_node
*n
)
2739 page
= list_first_entry_or_null(&n
->slabs_partial
,
2742 n
->free_touched
= 1;
2743 page
= list_first_entry_or_null(&n
->slabs_free
,
2750 static void *cache_alloc_refill(struct kmem_cache
*cachep
, gfp_t flags
,
2754 struct kmem_cache_node
*n
;
2755 struct array_cache
*ac
;
2759 node
= numa_mem_id();
2760 if (unlikely(force_refill
))
2763 ac
= cpu_cache_get(cachep
);
2764 batchcount
= ac
->batchcount
;
2765 if (!ac
->touched
&& batchcount
> BATCHREFILL_LIMIT
) {
2767 * If there was little recent activity on this cache, then
2768 * perform only a partial refill. Otherwise we could generate
2771 batchcount
= BATCHREFILL_LIMIT
;
2773 n
= get_node(cachep
, node
);
2775 BUG_ON(ac
->avail
> 0 || !n
);
2776 spin_lock(&n
->list_lock
);
2778 /* See if we can refill from the shared array */
2779 if (n
->shared
&& transfer_objects(ac
, n
->shared
, batchcount
)) {
2780 n
->shared
->touched
= 1;
2784 while (batchcount
> 0) {
2786 /* Get slab alloc is to come from. */
2787 page
= get_first_slab(n
);
2791 check_spinlock_acquired(cachep
);
2794 * The slab was either on partial or free list so
2795 * there must be at least one object available for
2798 BUG_ON(page
->active
>= cachep
->num
);
2800 while (page
->active
< cachep
->num
&& batchcount
--) {
2801 STATS_INC_ALLOCED(cachep
);
2802 STATS_INC_ACTIVE(cachep
);
2803 STATS_SET_HIGH(cachep
);
2805 ac_put_obj(cachep
, ac
, slab_get_obj(cachep
, page
));
2808 /* move slabp to correct slabp list: */
2809 list_del(&page
->lru
);
2810 if (page
->active
== cachep
->num
)
2811 list_add(&page
->lru
, &n
->slabs_full
);
2813 list_add(&page
->lru
, &n
->slabs_partial
);
2817 n
->free_objects
-= ac
->avail
;
2819 spin_unlock(&n
->list_lock
);
2821 if (unlikely(!ac
->avail
)) {
2824 x
= cache_grow(cachep
, gfp_exact_node(flags
), node
, NULL
);
2826 /* cache_grow can reenable interrupts, then ac could change. */
2827 ac
= cpu_cache_get(cachep
);
2828 node
= numa_mem_id();
2830 /* no objects in sight? abort */
2831 if (!x
&& (ac
->avail
== 0 || force_refill
))
2834 if (!ac
->avail
) /* objects refilled by interrupt? */
2839 return ac_get_obj(cachep
, ac
, flags
, force_refill
);
2842 static inline void cache_alloc_debugcheck_before(struct kmem_cache
*cachep
,
2845 might_sleep_if(gfpflags_allow_blocking(flags
));
2847 kmem_flagcheck(cachep
, flags
);
2852 static void *cache_alloc_debugcheck_after(struct kmem_cache
*cachep
,
2853 gfp_t flags
, void *objp
, unsigned long caller
)
2857 if (cachep
->flags
& SLAB_POISON
) {
2858 check_poison_obj(cachep
, objp
);
2859 slab_kernel_map(cachep
, objp
, 1, 0);
2860 poison_obj(cachep
, objp
, POISON_INUSE
);
2862 if (cachep
->flags
& SLAB_STORE_USER
)
2863 *dbg_userword(cachep
, objp
) = (void *)caller
;
2865 if (cachep
->flags
& SLAB_RED_ZONE
) {
2866 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
||
2867 *dbg_redzone2(cachep
, objp
) != RED_INACTIVE
) {
2868 slab_error(cachep
, "double free, or memory outside"
2869 " object was overwritten");
2871 "%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
2872 objp
, *dbg_redzone1(cachep
, objp
),
2873 *dbg_redzone2(cachep
, objp
));
2875 *dbg_redzone1(cachep
, objp
) = RED_ACTIVE
;
2876 *dbg_redzone2(cachep
, objp
) = RED_ACTIVE
;
2879 objp
+= obj_offset(cachep
);
2880 if (cachep
->ctor
&& cachep
->flags
& SLAB_POISON
)
2882 if (ARCH_SLAB_MINALIGN
&&
2883 ((unsigned long)objp
& (ARCH_SLAB_MINALIGN
-1))) {
2884 printk(KERN_ERR
"0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
2885 objp
, (int)ARCH_SLAB_MINALIGN
);
2890 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
2893 static inline void *____cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2896 struct array_cache
*ac
;
2897 bool force_refill
= false;
2901 ac
= cpu_cache_get(cachep
);
2902 if (likely(ac
->avail
)) {
2904 objp
= ac_get_obj(cachep
, ac
, flags
, false);
2907 * Allow for the possibility all avail objects are not allowed
2908 * by the current flags
2911 STATS_INC_ALLOCHIT(cachep
);
2914 force_refill
= true;
2917 STATS_INC_ALLOCMISS(cachep
);
2918 objp
= cache_alloc_refill(cachep
, flags
, force_refill
);
2920 * the 'ac' may be updated by cache_alloc_refill(),
2921 * and kmemleak_erase() requires its correct value.
2923 ac
= cpu_cache_get(cachep
);
2927 * To avoid a false negative, if an object that is in one of the
2928 * per-CPU caches is leaked, we need to make sure kmemleak doesn't
2929 * treat the array pointers as a reference to the object.
2932 kmemleak_erase(&ac
->entry
[ac
->avail
]);
2938 * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set.
2940 * If we are in_interrupt, then process context, including cpusets and
2941 * mempolicy, may not apply and should not be used for allocation policy.
2943 static void *alternate_node_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2945 int nid_alloc
, nid_here
;
2947 if (in_interrupt() || (flags
& __GFP_THISNODE
))
2949 nid_alloc
= nid_here
= numa_mem_id();
2950 if (cpuset_do_slab_mem_spread() && (cachep
->flags
& SLAB_MEM_SPREAD
))
2951 nid_alloc
= cpuset_slab_spread_node();
2952 else if (current
->mempolicy
)
2953 nid_alloc
= mempolicy_slab_node();
2954 if (nid_alloc
!= nid_here
)
2955 return ____cache_alloc_node(cachep
, flags
, nid_alloc
);
2960 * Fallback function if there was no memory available and no objects on a
2961 * certain node and fall back is permitted. First we scan all the
2962 * available node for available objects. If that fails then we
2963 * perform an allocation without specifying a node. This allows the page
2964 * allocator to do its reclaim / fallback magic. We then insert the
2965 * slab into the proper nodelist and then allocate from it.
2967 static void *fallback_alloc(struct kmem_cache
*cache
, gfp_t flags
)
2969 struct zonelist
*zonelist
;
2973 enum zone_type high_zoneidx
= gfp_zone(flags
);
2976 unsigned int cpuset_mems_cookie
;
2978 if (flags
& __GFP_THISNODE
)
2981 local_flags
= flags
& (GFP_CONSTRAINT_MASK
|GFP_RECLAIM_MASK
);
2984 cpuset_mems_cookie
= read_mems_allowed_begin();
2985 zonelist
= node_zonelist(mempolicy_slab_node(), flags
);
2989 * Look through allowed nodes for objects available
2990 * from existing per node queues.
2992 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
2993 nid
= zone_to_nid(zone
);
2995 if (cpuset_zone_allowed(zone
, flags
) &&
2996 get_node(cache
, nid
) &&
2997 get_node(cache
, nid
)->free_objects
) {
2998 obj
= ____cache_alloc_node(cache
,
2999 gfp_exact_node(flags
), nid
);
3007 * This allocation will be performed within the constraints
3008 * of the current cpuset / memory policy requirements.
3009 * We may trigger various forms of reclaim on the allowed
3010 * set and go into memory reserves if necessary.
3014 if (gfpflags_allow_blocking(local_flags
))
3016 kmem_flagcheck(cache
, flags
);
3017 page
= kmem_getpages(cache
, local_flags
, numa_mem_id());
3018 if (gfpflags_allow_blocking(local_flags
))
3019 local_irq_disable();
3022 * Insert into the appropriate per node queues
3024 nid
= page_to_nid(page
);
3025 if (cache_grow(cache
, flags
, nid
, page
)) {
3026 obj
= ____cache_alloc_node(cache
,
3027 gfp_exact_node(flags
), nid
);
3030 * Another processor may allocate the
3031 * objects in the slab since we are
3032 * not holding any locks.
3036 /* cache_grow already freed obj */
3042 if (unlikely(!obj
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3048 * A interface to enable slab creation on nodeid
3050 static void *____cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
,
3054 struct kmem_cache_node
*n
;
3058 VM_BUG_ON(nodeid
< 0 || nodeid
>= MAX_NUMNODES
);
3059 n
= get_node(cachep
, nodeid
);
3064 spin_lock(&n
->list_lock
);
3065 page
= get_first_slab(n
);
3069 check_spinlock_acquired_node(cachep
, nodeid
);
3071 STATS_INC_NODEALLOCS(cachep
);
3072 STATS_INC_ACTIVE(cachep
);
3073 STATS_SET_HIGH(cachep
);
3075 BUG_ON(page
->active
== cachep
->num
);
3077 obj
= slab_get_obj(cachep
, page
);
3079 /* move slabp to correct slabp list: */
3080 list_del(&page
->lru
);
3082 if (page
->active
== cachep
->num
)
3083 list_add(&page
->lru
, &n
->slabs_full
);
3085 list_add(&page
->lru
, &n
->slabs_partial
);
3087 spin_unlock(&n
->list_lock
);
3091 spin_unlock(&n
->list_lock
);
3092 x
= cache_grow(cachep
, gfp_exact_node(flags
), nodeid
, NULL
);
3096 return fallback_alloc(cachep
, flags
);
3102 static __always_inline
void *
3103 slab_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
,
3104 unsigned long caller
)
3106 unsigned long save_flags
;
3108 int slab_node
= numa_mem_id();
3110 flags
&= gfp_allowed_mask
;
3111 cachep
= slab_pre_alloc_hook(cachep
, flags
);
3112 if (unlikely(!cachep
))
3115 cache_alloc_debugcheck_before(cachep
, flags
);
3116 local_irq_save(save_flags
);
3118 if (nodeid
== NUMA_NO_NODE
)
3121 if (unlikely(!get_node(cachep
, nodeid
))) {
3122 /* Node not bootstrapped yet */
3123 ptr
= fallback_alloc(cachep
, flags
);
3127 if (nodeid
== slab_node
) {
3129 * Use the locally cached objects if possible.
3130 * However ____cache_alloc does not allow fallback
3131 * to other nodes. It may fail while we still have
3132 * objects on other nodes available.
3134 ptr
= ____cache_alloc(cachep
, flags
);
3138 /* ___cache_alloc_node can fall back to other nodes */
3139 ptr
= ____cache_alloc_node(cachep
, flags
, nodeid
);
3141 local_irq_restore(save_flags
);
3142 ptr
= cache_alloc_debugcheck_after(cachep
, flags
, ptr
, caller
);
3144 if (unlikely(flags
& __GFP_ZERO
) && ptr
)
3145 memset(ptr
, 0, cachep
->object_size
);
3147 slab_post_alloc_hook(cachep
, flags
, 1, &ptr
);
3151 static __always_inline
void *
3152 __do_cache_alloc(struct kmem_cache
*cache
, gfp_t flags
)
3156 if (current
->mempolicy
|| cpuset_do_slab_mem_spread()) {
3157 objp
= alternate_node_alloc(cache
, flags
);
3161 objp
= ____cache_alloc(cache
, flags
);
3164 * We may just have run out of memory on the local node.
3165 * ____cache_alloc_node() knows how to locate memory on other nodes
3168 objp
= ____cache_alloc_node(cache
, flags
, numa_mem_id());
3175 static __always_inline
void *
3176 __do_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3178 return ____cache_alloc(cachep
, flags
);
3181 #endif /* CONFIG_NUMA */
3183 static __always_inline
void *
3184 slab_alloc(struct kmem_cache
*cachep
, gfp_t flags
, unsigned long caller
)
3186 unsigned long save_flags
;
3189 flags
&= gfp_allowed_mask
;
3190 cachep
= slab_pre_alloc_hook(cachep
, flags
);
3191 if (unlikely(!cachep
))
3194 cache_alloc_debugcheck_before(cachep
, flags
);
3195 local_irq_save(save_flags
);
3196 objp
= __do_cache_alloc(cachep
, flags
);
3197 local_irq_restore(save_flags
);
3198 objp
= cache_alloc_debugcheck_after(cachep
, flags
, objp
, caller
);
3201 if (unlikely(flags
& __GFP_ZERO
) && objp
)
3202 memset(objp
, 0, cachep
->object_size
);
3204 slab_post_alloc_hook(cachep
, flags
, 1, &objp
);
3209 * Caller needs to acquire correct kmem_cache_node's list_lock
3210 * @list: List of detached free slabs should be freed by caller
3212 static void free_block(struct kmem_cache
*cachep
, void **objpp
,
3213 int nr_objects
, int node
, struct list_head
*list
)
3216 struct kmem_cache_node
*n
= get_node(cachep
, node
);
3218 for (i
= 0; i
< nr_objects
; i
++) {
3222 clear_obj_pfmemalloc(&objpp
[i
]);
3225 page
= virt_to_head_page(objp
);
3226 list_del(&page
->lru
);
3227 check_spinlock_acquired_node(cachep
, node
);
3228 slab_put_obj(cachep
, page
, objp
);
3229 STATS_DEC_ACTIVE(cachep
);
3232 /* fixup slab chains */
3233 if (page
->active
== 0) {
3234 if (n
->free_objects
> n
->free_limit
) {
3235 n
->free_objects
-= cachep
->num
;
3236 list_add_tail(&page
->lru
, list
);
3238 list_add(&page
->lru
, &n
->slabs_free
);
3241 /* Unconditionally move a slab to the end of the
3242 * partial list on free - maximum time for the
3243 * other objects to be freed, too.
3245 list_add_tail(&page
->lru
, &n
->slabs_partial
);
3250 static void cache_flusharray(struct kmem_cache
*cachep
, struct array_cache
*ac
)
3253 struct kmem_cache_node
*n
;
3254 int node
= numa_mem_id();
3257 batchcount
= ac
->batchcount
;
3260 n
= get_node(cachep
, node
);
3261 spin_lock(&n
->list_lock
);
3263 struct array_cache
*shared_array
= n
->shared
;
3264 int max
= shared_array
->limit
- shared_array
->avail
;
3266 if (batchcount
> max
)
3268 memcpy(&(shared_array
->entry
[shared_array
->avail
]),
3269 ac
->entry
, sizeof(void *) * batchcount
);
3270 shared_array
->avail
+= batchcount
;
3275 free_block(cachep
, ac
->entry
, batchcount
, node
, &list
);
3282 list_for_each_entry(page
, &n
->slabs_free
, lru
) {
3283 BUG_ON(page
->active
);
3287 STATS_SET_FREEABLE(cachep
, i
);
3290 spin_unlock(&n
->list_lock
);
3291 slabs_destroy(cachep
, &list
);
3292 ac
->avail
-= batchcount
;
3293 memmove(ac
->entry
, &(ac
->entry
[batchcount
]), sizeof(void *)*ac
->avail
);
3297 * Release an obj back to its cache. If the obj has a constructed state, it must
3298 * be in this state _before_ it is released. Called with disabled ints.
3300 static inline void __cache_free(struct kmem_cache
*cachep
, void *objp
,
3301 unsigned long caller
)
3303 struct array_cache
*ac
= cpu_cache_get(cachep
);
3306 kmemleak_free_recursive(objp
, cachep
->flags
);
3307 objp
= cache_free_debugcheck(cachep
, objp
, caller
);
3309 kmemcheck_slab_free(cachep
, objp
, cachep
->object_size
);
3312 * Skip calling cache_free_alien() when the platform is not numa.
3313 * This will avoid cache misses that happen while accessing slabp (which
3314 * is per page memory reference) to get nodeid. Instead use a global
3315 * variable to skip the call, which is mostly likely to be present in
3318 if (nr_online_nodes
> 1 && cache_free_alien(cachep
, objp
))
3321 if (ac
->avail
< ac
->limit
) {
3322 STATS_INC_FREEHIT(cachep
);
3324 STATS_INC_FREEMISS(cachep
);
3325 cache_flusharray(cachep
, ac
);
3328 ac_put_obj(cachep
, ac
, objp
);
3332 * kmem_cache_alloc - Allocate an object
3333 * @cachep: The cache to allocate from.
3334 * @flags: See kmalloc().
3336 * Allocate an object from this cache. The flags are only relevant
3337 * if the cache has no available objects.
3339 void *kmem_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3341 void *ret
= slab_alloc(cachep
, flags
, _RET_IP_
);
3343 trace_kmem_cache_alloc(_RET_IP_
, ret
,
3344 cachep
->object_size
, cachep
->size
, flags
);
3348 EXPORT_SYMBOL(kmem_cache_alloc
);
3350 static __always_inline
void
3351 cache_alloc_debugcheck_after_bulk(struct kmem_cache
*s
, gfp_t flags
,
3352 size_t size
, void **p
, unsigned long caller
)
3356 for (i
= 0; i
< size
; i
++)
3357 p
[i
] = cache_alloc_debugcheck_after(s
, flags
, p
[i
], caller
);
3360 int kmem_cache_alloc_bulk(struct kmem_cache
*s
, gfp_t flags
, size_t size
,
3365 s
= slab_pre_alloc_hook(s
, flags
);
3369 cache_alloc_debugcheck_before(s
, flags
);
3371 local_irq_disable();
3372 for (i
= 0; i
< size
; i
++) {
3373 void *objp
= __do_cache_alloc(s
, flags
);
3375 if (unlikely(!objp
))
3381 cache_alloc_debugcheck_after_bulk(s
, flags
, size
, p
, _RET_IP_
);
3383 /* Clear memory outside IRQ disabled section */
3384 if (unlikely(flags
& __GFP_ZERO
))
3385 for (i
= 0; i
< size
; i
++)
3386 memset(p
[i
], 0, s
->object_size
);
3388 slab_post_alloc_hook(s
, flags
, size
, p
);
3389 /* FIXME: Trace call missing. Christoph would like a bulk variant */
3393 cache_alloc_debugcheck_after_bulk(s
, flags
, i
, p
, _RET_IP_
);
3394 slab_post_alloc_hook(s
, flags
, i
, p
);
3395 __kmem_cache_free_bulk(s
, i
, p
);
3398 EXPORT_SYMBOL(kmem_cache_alloc_bulk
);
3400 #ifdef CONFIG_TRACING
3402 kmem_cache_alloc_trace(struct kmem_cache
*cachep
, gfp_t flags
, size_t size
)
3406 ret
= slab_alloc(cachep
, flags
, _RET_IP_
);
3408 trace_kmalloc(_RET_IP_
, ret
,
3409 size
, cachep
->size
, flags
);
3412 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
3417 * kmem_cache_alloc_node - Allocate an object on the specified node
3418 * @cachep: The cache to allocate from.
3419 * @flags: See kmalloc().
3420 * @nodeid: node number of the target node.
3422 * Identical to kmem_cache_alloc but it will allocate memory on the given
3423 * node, which can improve the performance for cpu bound structures.
3425 * Fallback to other node is possible if __GFP_THISNODE is not set.
3427 void *kmem_cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
3429 void *ret
= slab_alloc_node(cachep
, flags
, nodeid
, _RET_IP_
);
3431 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
3432 cachep
->object_size
, cachep
->size
,
3437 EXPORT_SYMBOL(kmem_cache_alloc_node
);
3439 #ifdef CONFIG_TRACING
3440 void *kmem_cache_alloc_node_trace(struct kmem_cache
*cachep
,
3447 ret
= slab_alloc_node(cachep
, flags
, nodeid
, _RET_IP_
);
3449 trace_kmalloc_node(_RET_IP_
, ret
,
3454 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
3457 static __always_inline
void *
3458 __do_kmalloc_node(size_t size
, gfp_t flags
, int node
, unsigned long caller
)
3460 struct kmem_cache
*cachep
;
3462 cachep
= kmalloc_slab(size
, flags
);
3463 if (unlikely(ZERO_OR_NULL_PTR(cachep
)))
3465 return kmem_cache_alloc_node_trace(cachep
, flags
, node
, size
);
3468 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3470 return __do_kmalloc_node(size
, flags
, node
, _RET_IP_
);
3472 EXPORT_SYMBOL(__kmalloc_node
);
3474 void *__kmalloc_node_track_caller(size_t size
, gfp_t flags
,
3475 int node
, unsigned long caller
)
3477 return __do_kmalloc_node(size
, flags
, node
, caller
);
3479 EXPORT_SYMBOL(__kmalloc_node_track_caller
);
3480 #endif /* CONFIG_NUMA */
3483 * __do_kmalloc - allocate memory
3484 * @size: how many bytes of memory are required.
3485 * @flags: the type of memory to allocate (see kmalloc).
3486 * @caller: function caller for debug tracking of the caller
3488 static __always_inline
void *__do_kmalloc(size_t size
, gfp_t flags
,
3489 unsigned long caller
)
3491 struct kmem_cache
*cachep
;
3494 cachep
= kmalloc_slab(size
, flags
);
3495 if (unlikely(ZERO_OR_NULL_PTR(cachep
)))
3497 ret
= slab_alloc(cachep
, flags
, caller
);
3499 trace_kmalloc(caller
, ret
,
3500 size
, cachep
->size
, flags
);
3505 void *__kmalloc(size_t size
, gfp_t flags
)
3507 return __do_kmalloc(size
, flags
, _RET_IP_
);
3509 EXPORT_SYMBOL(__kmalloc
);
3511 void *__kmalloc_track_caller(size_t size
, gfp_t flags
, unsigned long caller
)
3513 return __do_kmalloc(size
, flags
, caller
);
3515 EXPORT_SYMBOL(__kmalloc_track_caller
);
3518 * kmem_cache_free - Deallocate an object
3519 * @cachep: The cache the allocation was from.
3520 * @objp: The previously allocated object.
3522 * Free an object which was previously allocated from this
3525 void kmem_cache_free(struct kmem_cache
*cachep
, void *objp
)
3527 unsigned long flags
;
3528 cachep
= cache_from_obj(cachep
, objp
);
3532 local_irq_save(flags
);
3533 debug_check_no_locks_freed(objp
, cachep
->object_size
);
3534 if (!(cachep
->flags
& SLAB_DEBUG_OBJECTS
))
3535 debug_check_no_obj_freed(objp
, cachep
->object_size
);
3536 __cache_free(cachep
, objp
, _RET_IP_
);
3537 local_irq_restore(flags
);
3539 trace_kmem_cache_free(_RET_IP_
, objp
);
3541 EXPORT_SYMBOL(kmem_cache_free
);
3543 void kmem_cache_free_bulk(struct kmem_cache
*orig_s
, size_t size
, void **p
)
3545 struct kmem_cache
*s
;
3548 local_irq_disable();
3549 for (i
= 0; i
< size
; i
++) {
3552 if (!orig_s
) /* called via kfree_bulk */
3553 s
= virt_to_cache(objp
);
3555 s
= cache_from_obj(orig_s
, objp
);
3557 debug_check_no_locks_freed(objp
, s
->object_size
);
3558 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
3559 debug_check_no_obj_freed(objp
, s
->object_size
);
3561 __cache_free(s
, objp
, _RET_IP_
);
3565 /* FIXME: add tracing */
3567 EXPORT_SYMBOL(kmem_cache_free_bulk
);
3570 * kfree - free previously allocated memory
3571 * @objp: pointer returned by kmalloc.
3573 * If @objp is NULL, no operation is performed.
3575 * Don't free memory not originally allocated by kmalloc()
3576 * or you will run into trouble.
3578 void kfree(const void *objp
)
3580 struct kmem_cache
*c
;
3581 unsigned long flags
;
3583 trace_kfree(_RET_IP_
, objp
);
3585 if (unlikely(ZERO_OR_NULL_PTR(objp
)))
3587 local_irq_save(flags
);
3588 kfree_debugcheck(objp
);
3589 c
= virt_to_cache(objp
);
3590 debug_check_no_locks_freed(objp
, c
->object_size
);
3592 debug_check_no_obj_freed(objp
, c
->object_size
);
3593 __cache_free(c
, (void *)objp
, _RET_IP_
);
3594 local_irq_restore(flags
);
3596 EXPORT_SYMBOL(kfree
);
3599 * This initializes kmem_cache_node or resizes various caches for all nodes.
3601 static int alloc_kmem_cache_node(struct kmem_cache
*cachep
, gfp_t gfp
)
3604 struct kmem_cache_node
*n
;
3605 struct array_cache
*new_shared
;
3606 struct alien_cache
**new_alien
= NULL
;
3608 for_each_online_node(node
) {
3610 if (use_alien_caches
) {
3611 new_alien
= alloc_alien_cache(node
, cachep
->limit
, gfp
);
3617 if (cachep
->shared
) {
3618 new_shared
= alloc_arraycache(node
,
3619 cachep
->shared
*cachep
->batchcount
,
3622 free_alien_cache(new_alien
);
3627 n
= get_node(cachep
, node
);
3629 struct array_cache
*shared
= n
->shared
;
3632 spin_lock_irq(&n
->list_lock
);
3635 free_block(cachep
, shared
->entry
,
3636 shared
->avail
, node
, &list
);
3638 n
->shared
= new_shared
;
3640 n
->alien
= new_alien
;
3643 n
->free_limit
= (1 + nr_cpus_node(node
)) *
3644 cachep
->batchcount
+ cachep
->num
;
3645 spin_unlock_irq(&n
->list_lock
);
3646 slabs_destroy(cachep
, &list
);
3648 free_alien_cache(new_alien
);
3651 n
= kmalloc_node(sizeof(struct kmem_cache_node
), gfp
, node
);
3653 free_alien_cache(new_alien
);
3658 kmem_cache_node_init(n
);
3659 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
+
3660 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
3661 n
->shared
= new_shared
;
3662 n
->alien
= new_alien
;
3663 n
->free_limit
= (1 + nr_cpus_node(node
)) *
3664 cachep
->batchcount
+ cachep
->num
;
3665 cachep
->node
[node
] = n
;
3670 if (!cachep
->list
.next
) {
3671 /* Cache is not active yet. Roll back what we did */
3674 n
= get_node(cachep
, node
);
3677 free_alien_cache(n
->alien
);
3679 cachep
->node
[node
] = NULL
;
3687 /* Always called with the slab_mutex held */
3688 static int __do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3689 int batchcount
, int shared
, gfp_t gfp
)
3691 struct array_cache __percpu
*cpu_cache
, *prev
;
3694 cpu_cache
= alloc_kmem_cache_cpus(cachep
, limit
, batchcount
);
3698 prev
= cachep
->cpu_cache
;
3699 cachep
->cpu_cache
= cpu_cache
;
3700 kick_all_cpus_sync();
3703 cachep
->batchcount
= batchcount
;
3704 cachep
->limit
= limit
;
3705 cachep
->shared
= shared
;
3710 for_each_online_cpu(cpu
) {
3713 struct kmem_cache_node
*n
;
3714 struct array_cache
*ac
= per_cpu_ptr(prev
, cpu
);
3716 node
= cpu_to_mem(cpu
);
3717 n
= get_node(cachep
, node
);
3718 spin_lock_irq(&n
->list_lock
);
3719 free_block(cachep
, ac
->entry
, ac
->avail
, node
, &list
);
3720 spin_unlock_irq(&n
->list_lock
);
3721 slabs_destroy(cachep
, &list
);
3726 return alloc_kmem_cache_node(cachep
, gfp
);
3729 static int do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3730 int batchcount
, int shared
, gfp_t gfp
)
3733 struct kmem_cache
*c
;
3735 ret
= __do_tune_cpucache(cachep
, limit
, batchcount
, shared
, gfp
);
3737 if (slab_state
< FULL
)
3740 if ((ret
< 0) || !is_root_cache(cachep
))
3743 lockdep_assert_held(&slab_mutex
);
3744 for_each_memcg_cache(c
, cachep
) {
3745 /* return value determined by the root cache only */
3746 __do_tune_cpucache(c
, limit
, batchcount
, shared
, gfp
);
3752 /* Called with slab_mutex held always */
3753 static int enable_cpucache(struct kmem_cache
*cachep
, gfp_t gfp
)
3760 if (!is_root_cache(cachep
)) {
3761 struct kmem_cache
*root
= memcg_root_cache(cachep
);
3762 limit
= root
->limit
;
3763 shared
= root
->shared
;
3764 batchcount
= root
->batchcount
;
3767 if (limit
&& shared
&& batchcount
)
3770 * The head array serves three purposes:
3771 * - create a LIFO ordering, i.e. return objects that are cache-warm
3772 * - reduce the number of spinlock operations.
3773 * - reduce the number of linked list operations on the slab and
3774 * bufctl chains: array operations are cheaper.
3775 * The numbers are guessed, we should auto-tune as described by
3778 if (cachep
->size
> 131072)
3780 else if (cachep
->size
> PAGE_SIZE
)
3782 else if (cachep
->size
> 1024)
3784 else if (cachep
->size
> 256)
3790 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3791 * allocation behaviour: Most allocs on one cpu, most free operations
3792 * on another cpu. For these cases, an efficient object passing between
3793 * cpus is necessary. This is provided by a shared array. The array
3794 * replaces Bonwick's magazine layer.
3795 * On uniprocessor, it's functionally equivalent (but less efficient)
3796 * to a larger limit. Thus disabled by default.
3799 if (cachep
->size
<= PAGE_SIZE
&& num_possible_cpus() > 1)
3804 * With debugging enabled, large batchcount lead to excessively long
3805 * periods with disabled local interrupts. Limit the batchcount
3810 batchcount
= (limit
+ 1) / 2;
3812 err
= do_tune_cpucache(cachep
, limit
, batchcount
, shared
, gfp
);
3814 printk(KERN_ERR
"enable_cpucache failed for %s, error %d.\n",
3815 cachep
->name
, -err
);
3820 * Drain an array if it contains any elements taking the node lock only if
3821 * necessary. Note that the node listlock also protects the array_cache
3822 * if drain_array() is used on the shared array.
3824 static void drain_array(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
,
3825 struct array_cache
*ac
, int force
, int node
)
3830 if (!ac
|| !ac
->avail
)
3832 if (ac
->touched
&& !force
) {
3835 spin_lock_irq(&n
->list_lock
);
3837 tofree
= force
? ac
->avail
: (ac
->limit
+ 4) / 5;
3838 if (tofree
> ac
->avail
)
3839 tofree
= (ac
->avail
+ 1) / 2;
3840 free_block(cachep
, ac
->entry
, tofree
, node
, &list
);
3841 ac
->avail
-= tofree
;
3842 memmove(ac
->entry
, &(ac
->entry
[tofree
]),
3843 sizeof(void *) * ac
->avail
);
3845 spin_unlock_irq(&n
->list_lock
);
3846 slabs_destroy(cachep
, &list
);
3851 * cache_reap - Reclaim memory from caches.
3852 * @w: work descriptor
3854 * Called from workqueue/eventd every few seconds.
3856 * - clear the per-cpu caches for this CPU.
3857 * - return freeable pages to the main free memory pool.
3859 * If we cannot acquire the cache chain mutex then just give up - we'll try
3860 * again on the next iteration.
3862 static void cache_reap(struct work_struct
*w
)
3864 struct kmem_cache
*searchp
;
3865 struct kmem_cache_node
*n
;
3866 int node
= numa_mem_id();
3867 struct delayed_work
*work
= to_delayed_work(w
);
3869 if (!mutex_trylock(&slab_mutex
))
3870 /* Give up. Setup the next iteration. */
3873 list_for_each_entry(searchp
, &slab_caches
, list
) {
3877 * We only take the node lock if absolutely necessary and we
3878 * have established with reasonable certainty that
3879 * we can do some work if the lock was obtained.
3881 n
= get_node(searchp
, node
);
3883 reap_alien(searchp
, n
);
3885 drain_array(searchp
, n
, cpu_cache_get(searchp
), 0, node
);
3888 * These are racy checks but it does not matter
3889 * if we skip one check or scan twice.
3891 if (time_after(n
->next_reap
, jiffies
))
3894 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
;
3896 drain_array(searchp
, n
, n
->shared
, 0, node
);
3898 if (n
->free_touched
)
3899 n
->free_touched
= 0;
3903 freed
= drain_freelist(searchp
, n
, (n
->free_limit
+
3904 5 * searchp
->num
- 1) / (5 * searchp
->num
));
3905 STATS_ADD_REAPED(searchp
, freed
);
3911 mutex_unlock(&slab_mutex
);
3914 /* Set up the next iteration */
3915 schedule_delayed_work(work
, round_jiffies_relative(REAPTIMEOUT_AC
));
3918 #ifdef CONFIG_SLABINFO
3919 void get_slabinfo(struct kmem_cache
*cachep
, struct slabinfo
*sinfo
)
3922 unsigned long active_objs
;
3923 unsigned long num_objs
;
3924 unsigned long active_slabs
= 0;
3925 unsigned long num_slabs
, free_objects
= 0, shared_avail
= 0;
3929 struct kmem_cache_node
*n
;
3933 for_each_kmem_cache_node(cachep
, node
, n
) {
3936 spin_lock_irq(&n
->list_lock
);
3938 list_for_each_entry(page
, &n
->slabs_full
, lru
) {
3939 if (page
->active
!= cachep
->num
&& !error
)
3940 error
= "slabs_full accounting error";
3941 active_objs
+= cachep
->num
;
3944 list_for_each_entry(page
, &n
->slabs_partial
, lru
) {
3945 if (page
->active
== cachep
->num
&& !error
)
3946 error
= "slabs_partial accounting error";
3947 if (!page
->active
&& !error
)
3948 error
= "slabs_partial accounting error";
3949 active_objs
+= page
->active
;
3952 list_for_each_entry(page
, &n
->slabs_free
, lru
) {
3953 if (page
->active
&& !error
)
3954 error
= "slabs_free accounting error";
3957 free_objects
+= n
->free_objects
;
3959 shared_avail
+= n
->shared
->avail
;
3961 spin_unlock_irq(&n
->list_lock
);
3963 num_slabs
+= active_slabs
;
3964 num_objs
= num_slabs
* cachep
->num
;
3965 if (num_objs
- active_objs
!= free_objects
&& !error
)
3966 error
= "free_objects accounting error";
3968 name
= cachep
->name
;
3970 printk(KERN_ERR
"slab: cache %s error: %s\n", name
, error
);
3972 sinfo
->active_objs
= active_objs
;
3973 sinfo
->num_objs
= num_objs
;
3974 sinfo
->active_slabs
= active_slabs
;
3975 sinfo
->num_slabs
= num_slabs
;
3976 sinfo
->shared_avail
= shared_avail
;
3977 sinfo
->limit
= cachep
->limit
;
3978 sinfo
->batchcount
= cachep
->batchcount
;
3979 sinfo
->shared
= cachep
->shared
;
3980 sinfo
->objects_per_slab
= cachep
->num
;
3981 sinfo
->cache_order
= cachep
->gfporder
;
3984 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*cachep
)
3988 unsigned long high
= cachep
->high_mark
;
3989 unsigned long allocs
= cachep
->num_allocations
;
3990 unsigned long grown
= cachep
->grown
;
3991 unsigned long reaped
= cachep
->reaped
;
3992 unsigned long errors
= cachep
->errors
;
3993 unsigned long max_freeable
= cachep
->max_freeable
;
3994 unsigned long node_allocs
= cachep
->node_allocs
;
3995 unsigned long node_frees
= cachep
->node_frees
;
3996 unsigned long overflows
= cachep
->node_overflow
;
3998 seq_printf(m
, " : globalstat %7lu %6lu %5lu %4lu "
3999 "%4lu %4lu %4lu %4lu %4lu",
4000 allocs
, high
, grown
,
4001 reaped
, errors
, max_freeable
, node_allocs
,
4002 node_frees
, overflows
);
4006 unsigned long allochit
= atomic_read(&cachep
->allochit
);
4007 unsigned long allocmiss
= atomic_read(&cachep
->allocmiss
);
4008 unsigned long freehit
= atomic_read(&cachep
->freehit
);
4009 unsigned long freemiss
= atomic_read(&cachep
->freemiss
);
4011 seq_printf(m
, " : cpustat %6lu %6lu %6lu %6lu",
4012 allochit
, allocmiss
, freehit
, freemiss
);
4017 #define MAX_SLABINFO_WRITE 128
4019 * slabinfo_write - Tuning for the slab allocator
4021 * @buffer: user buffer
4022 * @count: data length
4025 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
4026 size_t count
, loff_t
*ppos
)
4028 char kbuf
[MAX_SLABINFO_WRITE
+ 1], *tmp
;
4029 int limit
, batchcount
, shared
, res
;
4030 struct kmem_cache
*cachep
;
4032 if (count
> MAX_SLABINFO_WRITE
)
4034 if (copy_from_user(&kbuf
, buffer
, count
))
4036 kbuf
[MAX_SLABINFO_WRITE
] = '\0';
4038 tmp
= strchr(kbuf
, ' ');
4043 if (sscanf(tmp
, " %d %d %d", &limit
, &batchcount
, &shared
) != 3)
4046 /* Find the cache in the chain of caches. */
4047 mutex_lock(&slab_mutex
);
4049 list_for_each_entry(cachep
, &slab_caches
, list
) {
4050 if (!strcmp(cachep
->name
, kbuf
)) {
4051 if (limit
< 1 || batchcount
< 1 ||
4052 batchcount
> limit
|| shared
< 0) {
4055 res
= do_tune_cpucache(cachep
, limit
,
4062 mutex_unlock(&slab_mutex
);
4068 #ifdef CONFIG_DEBUG_SLAB_LEAK
4070 static inline int add_caller(unsigned long *n
, unsigned long v
)
4080 unsigned long *q
= p
+ 2 * i
;
4094 memmove(p
+ 2, p
, n
[1] * 2 * sizeof(unsigned long) - ((void *)p
- (void *)n
));
4100 static void handle_slab(unsigned long *n
, struct kmem_cache
*c
,
4109 for (i
= 0, p
= page
->s_mem
; i
< c
->num
; i
++, p
+= c
->size
) {
4112 for (j
= page
->active
; j
< c
->num
; j
++) {
4113 if (get_free_obj(page
, j
) == i
) {
4123 * probe_kernel_read() is used for DEBUG_PAGEALLOC. page table
4124 * mapping is established when actual object allocation and
4125 * we could mistakenly access the unmapped object in the cpu
4128 if (probe_kernel_read(&v
, dbg_userword(c
, p
), sizeof(v
)))
4131 if (!add_caller(n
, v
))
4136 static void show_symbol(struct seq_file
*m
, unsigned long address
)
4138 #ifdef CONFIG_KALLSYMS
4139 unsigned long offset
, size
;
4140 char modname
[MODULE_NAME_LEN
], name
[KSYM_NAME_LEN
];
4142 if (lookup_symbol_attrs(address
, &size
, &offset
, modname
, name
) == 0) {
4143 seq_printf(m
, "%s+%#lx/%#lx", name
, offset
, size
);
4145 seq_printf(m
, " [%s]", modname
);
4149 seq_printf(m
, "%p", (void *)address
);
4152 static int leaks_show(struct seq_file
*m
, void *p
)
4154 struct kmem_cache
*cachep
= list_entry(p
, struct kmem_cache
, list
);
4156 struct kmem_cache_node
*n
;
4158 unsigned long *x
= m
->private;
4162 if (!(cachep
->flags
& SLAB_STORE_USER
))
4164 if (!(cachep
->flags
& SLAB_RED_ZONE
))
4168 * Set store_user_clean and start to grab stored user information
4169 * for all objects on this cache. If some alloc/free requests comes
4170 * during the processing, information would be wrong so restart
4174 set_store_user_clean(cachep
);
4175 drain_cpu_caches(cachep
);
4179 for_each_kmem_cache_node(cachep
, node
, n
) {
4182 spin_lock_irq(&n
->list_lock
);
4184 list_for_each_entry(page
, &n
->slabs_full
, lru
)
4185 handle_slab(x
, cachep
, page
);
4186 list_for_each_entry(page
, &n
->slabs_partial
, lru
)
4187 handle_slab(x
, cachep
, page
);
4188 spin_unlock_irq(&n
->list_lock
);
4190 } while (!is_store_user_clean(cachep
));
4192 name
= cachep
->name
;
4194 /* Increase the buffer size */
4195 mutex_unlock(&slab_mutex
);
4196 m
->private = kzalloc(x
[0] * 4 * sizeof(unsigned long), GFP_KERNEL
);
4198 /* Too bad, we are really out */
4200 mutex_lock(&slab_mutex
);
4203 *(unsigned long *)m
->private = x
[0] * 2;
4205 mutex_lock(&slab_mutex
);
4206 /* Now make sure this entry will be retried */
4210 for (i
= 0; i
< x
[1]; i
++) {
4211 seq_printf(m
, "%s: %lu ", name
, x
[2*i
+3]);
4212 show_symbol(m
, x
[2*i
+2]);
4219 static const struct seq_operations slabstats_op
= {
4220 .start
= slab_start
,
4226 static int slabstats_open(struct inode
*inode
, struct file
*file
)
4230 n
= __seq_open_private(file
, &slabstats_op
, PAGE_SIZE
);
4234 *n
= PAGE_SIZE
/ (2 * sizeof(unsigned long));
4239 static const struct file_operations proc_slabstats_operations
= {
4240 .open
= slabstats_open
,
4242 .llseek
= seq_lseek
,
4243 .release
= seq_release_private
,
4247 static int __init
slab_proc_init(void)
4249 #ifdef CONFIG_DEBUG_SLAB_LEAK
4250 proc_create("slab_allocators", 0, NULL
, &proc_slabstats_operations
);
4254 module_init(slab_proc_init
);
4258 * ksize - get the actual amount of memory allocated for a given object
4259 * @objp: Pointer to the object
4261 * kmalloc may internally round up allocations and return more memory
4262 * than requested. ksize() can be used to determine the actual amount of
4263 * memory allocated. The caller may use this additional memory, even though
4264 * a smaller amount of memory was initially specified with the kmalloc call.
4265 * The caller must guarantee that objp points to a valid object previously
4266 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4267 * must not be freed during the duration of the call.
4269 size_t ksize(const void *objp
)
4272 if (unlikely(objp
== ZERO_SIZE_PTR
))
4275 return virt_to_cache(objp
)->object_size
;
4277 EXPORT_SYMBOL(ksize
);