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 * bootstrap: The caches do not work without cpuarrays anymore, but the
229 * cpuarrays are allocated from the generic caches...
231 #define BOOT_CPUCACHE_ENTRIES 1
232 struct arraycache_init
{
233 struct array_cache cache
;
234 void *entries
[BOOT_CPUCACHE_ENTRIES
];
238 * Need this for bootstrapping a per node allocator.
240 #define NUM_INIT_LISTS (2 * MAX_NUMNODES)
241 static struct kmem_cache_node __initdata init_kmem_cache_node
[NUM_INIT_LISTS
];
242 #define CACHE_CACHE 0
243 #define SIZE_NODE (MAX_NUMNODES)
245 static int drain_freelist(struct kmem_cache
*cache
,
246 struct kmem_cache_node
*n
, int tofree
);
247 static void free_block(struct kmem_cache
*cachep
, void **objpp
, int len
,
248 int node
, struct list_head
*list
);
249 static void slabs_destroy(struct kmem_cache
*cachep
, struct list_head
*list
);
250 static int enable_cpucache(struct kmem_cache
*cachep
, gfp_t gfp
);
251 static void cache_reap(struct work_struct
*unused
);
253 static int slab_early_init
= 1;
255 #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node))
257 static void kmem_cache_node_init(struct kmem_cache_node
*parent
)
259 INIT_LIST_HEAD(&parent
->slabs_full
);
260 INIT_LIST_HEAD(&parent
->slabs_partial
);
261 INIT_LIST_HEAD(&parent
->slabs_free
);
262 parent
->shared
= NULL
;
263 parent
->alien
= NULL
;
264 parent
->colour_next
= 0;
265 spin_lock_init(&parent
->list_lock
);
266 parent
->free_objects
= 0;
267 parent
->free_touched
= 0;
270 #define MAKE_LIST(cachep, listp, slab, nodeid) \
272 INIT_LIST_HEAD(listp); \
273 list_splice(&get_node(cachep, nodeid)->slab, listp); \
276 #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
278 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
279 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
280 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
283 #define CFLGS_OFF_SLAB (0x80000000UL)
284 #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
285 #define OFF_SLAB_MIN_SIZE (max_t(size_t, PAGE_SIZE >> 5, KMALLOC_MIN_SIZE + 1))
287 #define BATCHREFILL_LIMIT 16
289 * Optimization question: fewer reaps means less probability for unnessary
290 * cpucache drain/refill cycles.
292 * OTOH the cpuarrays can contain lots of objects,
293 * which could lock up otherwise freeable slabs.
295 #define REAPTIMEOUT_AC (2*HZ)
296 #define REAPTIMEOUT_NODE (4*HZ)
299 #define STATS_INC_ACTIVE(x) ((x)->num_active++)
300 #define STATS_DEC_ACTIVE(x) ((x)->num_active--)
301 #define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
302 #define STATS_INC_GROWN(x) ((x)->grown++)
303 #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
304 #define STATS_SET_HIGH(x) \
306 if ((x)->num_active > (x)->high_mark) \
307 (x)->high_mark = (x)->num_active; \
309 #define STATS_INC_ERR(x) ((x)->errors++)
310 #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
311 #define STATS_INC_NODEFREES(x) ((x)->node_frees++)
312 #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
313 #define STATS_SET_FREEABLE(x, i) \
315 if ((x)->max_freeable < i) \
316 (x)->max_freeable = i; \
318 #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
319 #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
320 #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
321 #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
323 #define STATS_INC_ACTIVE(x) do { } while (0)
324 #define STATS_DEC_ACTIVE(x) do { } while (0)
325 #define STATS_INC_ALLOCED(x) do { } while (0)
326 #define STATS_INC_GROWN(x) do { } while (0)
327 #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0)
328 #define STATS_SET_HIGH(x) do { } while (0)
329 #define STATS_INC_ERR(x) do { } while (0)
330 #define STATS_INC_NODEALLOCS(x) do { } while (0)
331 #define STATS_INC_NODEFREES(x) do { } while (0)
332 #define STATS_INC_ACOVERFLOW(x) do { } while (0)
333 #define STATS_SET_FREEABLE(x, i) do { } while (0)
334 #define STATS_INC_ALLOCHIT(x) do { } while (0)
335 #define STATS_INC_ALLOCMISS(x) do { } while (0)
336 #define STATS_INC_FREEHIT(x) do { } while (0)
337 #define STATS_INC_FREEMISS(x) do { } while (0)
343 * memory layout of objects:
345 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
346 * the end of an object is aligned with the end of the real
347 * allocation. Catches writes behind the end of the allocation.
348 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
350 * cachep->obj_offset: The real object.
351 * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
352 * cachep->size - 1* BYTES_PER_WORD: last caller address
353 * [BYTES_PER_WORD long]
355 static int obj_offset(struct kmem_cache
*cachep
)
357 return cachep
->obj_offset
;
360 static unsigned long long *dbg_redzone1(struct kmem_cache
*cachep
, void *objp
)
362 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
363 return (unsigned long long*) (objp
+ obj_offset(cachep
) -
364 sizeof(unsigned long long));
367 static unsigned long long *dbg_redzone2(struct kmem_cache
*cachep
, void *objp
)
369 BUG_ON(!(cachep
->flags
& SLAB_RED_ZONE
));
370 if (cachep
->flags
& SLAB_STORE_USER
)
371 return (unsigned long long *)(objp
+ cachep
->size
-
372 sizeof(unsigned long long) -
374 return (unsigned long long *) (objp
+ cachep
->size
-
375 sizeof(unsigned long long));
378 static void **dbg_userword(struct kmem_cache
*cachep
, void *objp
)
380 BUG_ON(!(cachep
->flags
& SLAB_STORE_USER
));
381 return (void **)(objp
+ cachep
->size
- BYTES_PER_WORD
);
386 #define obj_offset(x) 0
387 #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
388 #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
389 #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
393 #ifdef CONFIG_DEBUG_SLAB_LEAK
395 static inline bool is_store_user_clean(struct kmem_cache
*cachep
)
397 return atomic_read(&cachep
->store_user_clean
) == 1;
400 static inline void set_store_user_clean(struct kmem_cache
*cachep
)
402 atomic_set(&cachep
->store_user_clean
, 1);
405 static inline void set_store_user_dirty(struct kmem_cache
*cachep
)
407 if (is_store_user_clean(cachep
))
408 atomic_set(&cachep
->store_user_clean
, 0);
412 static inline void set_store_user_dirty(struct kmem_cache
*cachep
) {}
417 * Do not go above this order unless 0 objects fit into the slab or
418 * overridden on the command line.
420 #define SLAB_MAX_ORDER_HI 1
421 #define SLAB_MAX_ORDER_LO 0
422 static int slab_max_order
= SLAB_MAX_ORDER_LO
;
423 static bool slab_max_order_set __initdata
;
425 static inline struct kmem_cache
*virt_to_cache(const void *obj
)
427 struct page
*page
= virt_to_head_page(obj
);
428 return page
->slab_cache
;
431 static inline void *index_to_obj(struct kmem_cache
*cache
, struct page
*page
,
434 return page
->s_mem
+ cache
->size
* idx
;
438 * We want to avoid an expensive divide : (offset / cache->size)
439 * Using the fact that size is a constant for a particular cache,
440 * we can replace (offset / cache->size) by
441 * reciprocal_divide(offset, cache->reciprocal_buffer_size)
443 static inline unsigned int obj_to_index(const struct kmem_cache
*cache
,
444 const struct page
*page
, void *obj
)
446 u32 offset
= (obj
- page
->s_mem
);
447 return reciprocal_divide(offset
, cache
->reciprocal_buffer_size
);
450 /* internal cache of cache description objs */
451 static struct kmem_cache kmem_cache_boot
= {
453 .limit
= BOOT_CPUCACHE_ENTRIES
,
455 .size
= sizeof(struct kmem_cache
),
456 .name
= "kmem_cache",
459 #define BAD_ALIEN_MAGIC 0x01020304ul
461 static DEFINE_PER_CPU(struct delayed_work
, slab_reap_work
);
463 static inline struct array_cache
*cpu_cache_get(struct kmem_cache
*cachep
)
465 return this_cpu_ptr(cachep
->cpu_cache
);
468 static size_t calculate_freelist_size(int nr_objs
, size_t align
)
470 size_t freelist_size
;
472 freelist_size
= nr_objs
* sizeof(freelist_idx_t
);
474 freelist_size
= ALIGN(freelist_size
, align
);
476 return freelist_size
;
479 static int calculate_nr_objs(size_t slab_size
, size_t buffer_size
,
480 size_t idx_size
, size_t align
)
483 size_t remained_size
;
484 size_t freelist_size
;
487 * Ignore padding for the initial guess. The padding
488 * is at most @align-1 bytes, and @buffer_size is at
489 * least @align. In the worst case, this result will
490 * be one greater than the number of objects that fit
491 * into the memory allocation when taking the padding
494 nr_objs
= slab_size
/ (buffer_size
+ idx_size
);
497 * This calculated number will be either the right
498 * amount, or one greater than what we want.
500 remained_size
= slab_size
- nr_objs
* buffer_size
;
501 freelist_size
= calculate_freelist_size(nr_objs
, align
);
502 if (remained_size
< freelist_size
)
509 * Calculate the number of objects and left-over bytes for a given buffer size.
511 static void cache_estimate(unsigned long gfporder
, size_t buffer_size
,
512 size_t align
, int flags
, size_t *left_over
,
517 size_t slab_size
= PAGE_SIZE
<< gfporder
;
520 * The slab management structure can be either off the slab or
521 * on it. For the latter case, the memory allocated for a
524 * - One unsigned int for each object
525 * - Padding to respect alignment of @align
526 * - @buffer_size bytes for each object
528 * If the slab management structure is off the slab, then the
529 * alignment will already be calculated into the size. Because
530 * the slabs are all pages aligned, the objects will be at the
531 * correct alignment when allocated.
533 if (flags
& CFLGS_OFF_SLAB
) {
535 nr_objs
= slab_size
/ buffer_size
;
538 nr_objs
= calculate_nr_objs(slab_size
, buffer_size
,
539 sizeof(freelist_idx_t
), align
);
540 mgmt_size
= calculate_freelist_size(nr_objs
, align
);
543 *left_over
= slab_size
- nr_objs
*buffer_size
- mgmt_size
;
547 #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
549 static void __slab_error(const char *function
, struct kmem_cache
*cachep
,
552 printk(KERN_ERR
"slab error in %s(): cache `%s': %s\n",
553 function
, cachep
->name
, msg
);
555 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
560 * By default on NUMA we use alien caches to stage the freeing of
561 * objects allocated from other nodes. This causes massive memory
562 * inefficiencies when using fake NUMA setup to split memory into a
563 * large number of small nodes, so it can be disabled on the command
567 static int use_alien_caches __read_mostly
= 1;
568 static int __init
noaliencache_setup(char *s
)
570 use_alien_caches
= 0;
573 __setup("noaliencache", noaliencache_setup
);
575 static int __init
slab_max_order_setup(char *str
)
577 get_option(&str
, &slab_max_order
);
578 slab_max_order
= slab_max_order
< 0 ? 0 :
579 min(slab_max_order
, MAX_ORDER
- 1);
580 slab_max_order_set
= true;
584 __setup("slab_max_order=", slab_max_order_setup
);
588 * Special reaping functions for NUMA systems called from cache_reap().
589 * These take care of doing round robin flushing of alien caches (containing
590 * objects freed on different nodes from which they were allocated) and the
591 * flushing of remote pcps by calling drain_node_pages.
593 static DEFINE_PER_CPU(unsigned long, slab_reap_node
);
595 static void init_reap_node(int cpu
)
599 node
= next_node(cpu_to_mem(cpu
), node_online_map
);
600 if (node
== MAX_NUMNODES
)
601 node
= first_node(node_online_map
);
603 per_cpu(slab_reap_node
, cpu
) = node
;
606 static void next_reap_node(void)
608 int node
= __this_cpu_read(slab_reap_node
);
610 node
= next_node(node
, node_online_map
);
611 if (unlikely(node
>= MAX_NUMNODES
))
612 node
= first_node(node_online_map
);
613 __this_cpu_write(slab_reap_node
, node
);
617 #define init_reap_node(cpu) do { } while (0)
618 #define next_reap_node(void) do { } while (0)
622 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
623 * via the workqueue/eventd.
624 * Add the CPU number into the expiration time to minimize the possibility of
625 * the CPUs getting into lockstep and contending for the global cache chain
628 static void start_cpu_timer(int cpu
)
630 struct delayed_work
*reap_work
= &per_cpu(slab_reap_work
, cpu
);
633 * When this gets called from do_initcalls via cpucache_init(),
634 * init_workqueues() has already run, so keventd will be setup
637 if (keventd_up() && reap_work
->work
.func
== NULL
) {
639 INIT_DEFERRABLE_WORK(reap_work
, cache_reap
);
640 schedule_delayed_work_on(cpu
, reap_work
,
641 __round_jiffies_relative(HZ
, cpu
));
645 static void init_arraycache(struct array_cache
*ac
, int limit
, int batch
)
648 * The array_cache structures contain pointers to free object.
649 * However, when such objects are allocated or transferred to another
650 * cache the pointers are not cleared and they could be counted as
651 * valid references during a kmemleak scan. Therefore, kmemleak must
652 * not scan such objects.
654 kmemleak_no_scan(ac
);
658 ac
->batchcount
= batch
;
663 static struct array_cache
*alloc_arraycache(int node
, int entries
,
664 int batchcount
, gfp_t gfp
)
666 size_t memsize
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
667 struct array_cache
*ac
= NULL
;
669 ac
= kmalloc_node(memsize
, gfp
, node
);
670 init_arraycache(ac
, entries
, batchcount
);
674 static inline bool is_slab_pfmemalloc(struct page
*page
)
676 return PageSlabPfmemalloc(page
);
679 /* Clears pfmemalloc_active if no slabs have pfmalloc set */
680 static void recheck_pfmemalloc_active(struct kmem_cache
*cachep
,
681 struct array_cache
*ac
)
683 struct kmem_cache_node
*n
= get_node(cachep
, numa_mem_id());
687 if (!pfmemalloc_active
)
690 spin_lock_irqsave(&n
->list_lock
, flags
);
691 list_for_each_entry(page
, &n
->slabs_full
, lru
)
692 if (is_slab_pfmemalloc(page
))
695 list_for_each_entry(page
, &n
->slabs_partial
, lru
)
696 if (is_slab_pfmemalloc(page
))
699 list_for_each_entry(page
, &n
->slabs_free
, lru
)
700 if (is_slab_pfmemalloc(page
))
703 pfmemalloc_active
= false;
705 spin_unlock_irqrestore(&n
->list_lock
, flags
);
708 static void *__ac_get_obj(struct kmem_cache
*cachep
, struct array_cache
*ac
,
709 gfp_t flags
, bool force_refill
)
712 void *objp
= ac
->entry
[--ac
->avail
];
714 /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */
715 if (unlikely(is_obj_pfmemalloc(objp
))) {
716 struct kmem_cache_node
*n
;
718 if (gfp_pfmemalloc_allowed(flags
)) {
719 clear_obj_pfmemalloc(&objp
);
723 /* The caller cannot use PFMEMALLOC objects, find another one */
724 for (i
= 0; i
< ac
->avail
; i
++) {
725 /* If a !PFMEMALLOC object is found, swap them */
726 if (!is_obj_pfmemalloc(ac
->entry
[i
])) {
728 ac
->entry
[i
] = ac
->entry
[ac
->avail
];
729 ac
->entry
[ac
->avail
] = objp
;
735 * If there are empty slabs on the slabs_free list and we are
736 * being forced to refill the cache, mark this one !pfmemalloc.
738 n
= get_node(cachep
, numa_mem_id());
739 if (!list_empty(&n
->slabs_free
) && force_refill
) {
740 struct page
*page
= virt_to_head_page(objp
);
741 ClearPageSlabPfmemalloc(page
);
742 clear_obj_pfmemalloc(&objp
);
743 recheck_pfmemalloc_active(cachep
, ac
);
747 /* No !PFMEMALLOC objects available */
755 static inline void *ac_get_obj(struct kmem_cache
*cachep
,
756 struct array_cache
*ac
, gfp_t flags
, bool force_refill
)
760 if (unlikely(sk_memalloc_socks()))
761 objp
= __ac_get_obj(cachep
, ac
, flags
, force_refill
);
763 objp
= ac
->entry
[--ac
->avail
];
768 static noinline
void *__ac_put_obj(struct kmem_cache
*cachep
,
769 struct array_cache
*ac
, void *objp
)
771 if (unlikely(pfmemalloc_active
)) {
772 /* Some pfmemalloc slabs exist, check if this is one */
773 struct page
*page
= virt_to_head_page(objp
);
774 if (PageSlabPfmemalloc(page
))
775 set_obj_pfmemalloc(&objp
);
781 static inline void ac_put_obj(struct kmem_cache
*cachep
, struct array_cache
*ac
,
784 if (unlikely(sk_memalloc_socks()))
785 objp
= __ac_put_obj(cachep
, ac
, objp
);
787 ac
->entry
[ac
->avail
++] = objp
;
791 * Transfer objects in one arraycache to another.
792 * Locking must be handled by the caller.
794 * Return the number of entries transferred.
796 static int transfer_objects(struct array_cache
*to
,
797 struct array_cache
*from
, unsigned int max
)
799 /* Figure out how many entries to transfer */
800 int nr
= min3(from
->avail
, max
, to
->limit
- to
->avail
);
805 memcpy(to
->entry
+ to
->avail
, from
->entry
+ from
->avail
-nr
,
815 #define drain_alien_cache(cachep, alien) do { } while (0)
816 #define reap_alien(cachep, n) do { } while (0)
818 static inline struct alien_cache
**alloc_alien_cache(int node
,
819 int limit
, gfp_t gfp
)
821 return (struct alien_cache
**)BAD_ALIEN_MAGIC
;
824 static inline void free_alien_cache(struct alien_cache
**ac_ptr
)
828 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
833 static inline void *alternate_node_alloc(struct kmem_cache
*cachep
,
839 static inline void *____cache_alloc_node(struct kmem_cache
*cachep
,
840 gfp_t flags
, int nodeid
)
845 static inline gfp_t
gfp_exact_node(gfp_t flags
)
850 #else /* CONFIG_NUMA */
852 static void *____cache_alloc_node(struct kmem_cache
*, gfp_t
, int);
853 static void *alternate_node_alloc(struct kmem_cache
*, gfp_t
);
855 static struct alien_cache
*__alloc_alien_cache(int node
, int entries
,
856 int batch
, gfp_t gfp
)
858 size_t memsize
= sizeof(void *) * entries
+ sizeof(struct alien_cache
);
859 struct alien_cache
*alc
= NULL
;
861 alc
= kmalloc_node(memsize
, gfp
, node
);
862 init_arraycache(&alc
->ac
, entries
, batch
);
863 spin_lock_init(&alc
->lock
);
867 static struct alien_cache
**alloc_alien_cache(int node
, int limit
, gfp_t gfp
)
869 struct alien_cache
**alc_ptr
;
870 size_t memsize
= sizeof(void *) * nr_node_ids
;
875 alc_ptr
= kzalloc_node(memsize
, gfp
, node
);
880 if (i
== node
|| !node_online(i
))
882 alc_ptr
[i
] = __alloc_alien_cache(node
, limit
, 0xbaadf00d, gfp
);
884 for (i
--; i
>= 0; i
--)
893 static void free_alien_cache(struct alien_cache
**alc_ptr
)
904 static void __drain_alien_cache(struct kmem_cache
*cachep
,
905 struct array_cache
*ac
, int node
,
906 struct list_head
*list
)
908 struct kmem_cache_node
*n
= get_node(cachep
, node
);
911 spin_lock(&n
->list_lock
);
913 * Stuff objects into the remote nodes shared array first.
914 * That way we could avoid the overhead of putting the objects
915 * into the free lists and getting them back later.
918 transfer_objects(n
->shared
, ac
, ac
->limit
);
920 free_block(cachep
, ac
->entry
, ac
->avail
, node
, list
);
922 spin_unlock(&n
->list_lock
);
927 * Called from cache_reap() to regularly drain alien caches round robin.
929 static void reap_alien(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
)
931 int node
= __this_cpu_read(slab_reap_node
);
934 struct alien_cache
*alc
= n
->alien
[node
];
935 struct array_cache
*ac
;
939 if (ac
->avail
&& spin_trylock_irq(&alc
->lock
)) {
942 __drain_alien_cache(cachep
, ac
, node
, &list
);
943 spin_unlock_irq(&alc
->lock
);
944 slabs_destroy(cachep
, &list
);
950 static void drain_alien_cache(struct kmem_cache
*cachep
,
951 struct alien_cache
**alien
)
954 struct alien_cache
*alc
;
955 struct array_cache
*ac
;
958 for_each_online_node(i
) {
964 spin_lock_irqsave(&alc
->lock
, flags
);
965 __drain_alien_cache(cachep
, ac
, i
, &list
);
966 spin_unlock_irqrestore(&alc
->lock
, flags
);
967 slabs_destroy(cachep
, &list
);
972 static int __cache_free_alien(struct kmem_cache
*cachep
, void *objp
,
973 int node
, int page_node
)
975 struct kmem_cache_node
*n
;
976 struct alien_cache
*alien
= NULL
;
977 struct array_cache
*ac
;
980 n
= get_node(cachep
, node
);
981 STATS_INC_NODEFREES(cachep
);
982 if (n
->alien
&& n
->alien
[page_node
]) {
983 alien
= n
->alien
[page_node
];
985 spin_lock(&alien
->lock
);
986 if (unlikely(ac
->avail
== ac
->limit
)) {
987 STATS_INC_ACOVERFLOW(cachep
);
988 __drain_alien_cache(cachep
, ac
, page_node
, &list
);
990 ac_put_obj(cachep
, ac
, objp
);
991 spin_unlock(&alien
->lock
);
992 slabs_destroy(cachep
, &list
);
994 n
= get_node(cachep
, page_node
);
995 spin_lock(&n
->list_lock
);
996 free_block(cachep
, &objp
, 1, page_node
, &list
);
997 spin_unlock(&n
->list_lock
);
998 slabs_destroy(cachep
, &list
);
1003 static inline int cache_free_alien(struct kmem_cache
*cachep
, void *objp
)
1005 int page_node
= page_to_nid(virt_to_page(objp
));
1006 int node
= numa_mem_id();
1008 * Make sure we are not freeing a object from another node to the array
1009 * cache on this cpu.
1011 if (likely(node
== page_node
))
1014 return __cache_free_alien(cachep
, objp
, node
, page_node
);
1018 * Construct gfp mask to allocate from a specific node but do not direct reclaim
1019 * or warn about failures. kswapd may still wake to reclaim in the background.
1021 static inline gfp_t
gfp_exact_node(gfp_t flags
)
1023 return (flags
| __GFP_THISNODE
| __GFP_NOWARN
) & ~__GFP_DIRECT_RECLAIM
;
1028 * Allocates and initializes node for a node on each slab cache, used for
1029 * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
1030 * will be allocated off-node since memory is not yet online for the new node.
1031 * When hotplugging memory or a cpu, existing node are not replaced if
1034 * Must hold slab_mutex.
1036 static int init_cache_node_node(int node
)
1038 struct kmem_cache
*cachep
;
1039 struct kmem_cache_node
*n
;
1040 const size_t memsize
= sizeof(struct kmem_cache_node
);
1042 list_for_each_entry(cachep
, &slab_caches
, list
) {
1044 * Set up the kmem_cache_node for cpu before we can
1045 * begin anything. Make sure some other cpu on this
1046 * node has not already allocated this
1048 n
= get_node(cachep
, node
);
1050 n
= kmalloc_node(memsize
, GFP_KERNEL
, node
);
1053 kmem_cache_node_init(n
);
1054 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
+
1055 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
1058 * The kmem_cache_nodes don't come and go as CPUs
1059 * come and go. slab_mutex is sufficient
1062 cachep
->node
[node
] = n
;
1065 spin_lock_irq(&n
->list_lock
);
1067 (1 + nr_cpus_node(node
)) *
1068 cachep
->batchcount
+ cachep
->num
;
1069 spin_unlock_irq(&n
->list_lock
);
1074 static inline int slabs_tofree(struct kmem_cache
*cachep
,
1075 struct kmem_cache_node
*n
)
1077 return (n
->free_objects
+ cachep
->num
- 1) / cachep
->num
;
1080 static void cpuup_canceled(long cpu
)
1082 struct kmem_cache
*cachep
;
1083 struct kmem_cache_node
*n
= NULL
;
1084 int node
= cpu_to_mem(cpu
);
1085 const struct cpumask
*mask
= cpumask_of_node(node
);
1087 list_for_each_entry(cachep
, &slab_caches
, list
) {
1088 struct array_cache
*nc
;
1089 struct array_cache
*shared
;
1090 struct alien_cache
**alien
;
1093 n
= get_node(cachep
, node
);
1097 spin_lock_irq(&n
->list_lock
);
1099 /* Free limit for this kmem_cache_node */
1100 n
->free_limit
-= cachep
->batchcount
;
1102 /* cpu is dead; no one can alloc from it. */
1103 nc
= per_cpu_ptr(cachep
->cpu_cache
, cpu
);
1105 free_block(cachep
, nc
->entry
, nc
->avail
, node
, &list
);
1109 if (!cpumask_empty(mask
)) {
1110 spin_unlock_irq(&n
->list_lock
);
1116 free_block(cachep
, shared
->entry
,
1117 shared
->avail
, node
, &list
);
1124 spin_unlock_irq(&n
->list_lock
);
1128 drain_alien_cache(cachep
, alien
);
1129 free_alien_cache(alien
);
1133 slabs_destroy(cachep
, &list
);
1136 * In the previous loop, all the objects were freed to
1137 * the respective cache's slabs, now we can go ahead and
1138 * shrink each nodelist to its limit.
1140 list_for_each_entry(cachep
, &slab_caches
, list
) {
1141 n
= get_node(cachep
, node
);
1144 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
1148 static int cpuup_prepare(long cpu
)
1150 struct kmem_cache
*cachep
;
1151 struct kmem_cache_node
*n
= NULL
;
1152 int node
= cpu_to_mem(cpu
);
1156 * We need to do this right in the beginning since
1157 * alloc_arraycache's are going to use this list.
1158 * kmalloc_node allows us to add the slab to the right
1159 * kmem_cache_node and not this cpu's kmem_cache_node
1161 err
= init_cache_node_node(node
);
1166 * Now we can go ahead with allocating the shared arrays and
1169 list_for_each_entry(cachep
, &slab_caches
, list
) {
1170 struct array_cache
*shared
= NULL
;
1171 struct alien_cache
**alien
= NULL
;
1173 if (cachep
->shared
) {
1174 shared
= alloc_arraycache(node
,
1175 cachep
->shared
* cachep
->batchcount
,
1176 0xbaadf00d, GFP_KERNEL
);
1180 if (use_alien_caches
) {
1181 alien
= alloc_alien_cache(node
, cachep
->limit
, GFP_KERNEL
);
1187 n
= get_node(cachep
, node
);
1190 spin_lock_irq(&n
->list_lock
);
1193 * We are serialised from CPU_DEAD or
1194 * CPU_UP_CANCELLED by the cpucontrol lock
1205 spin_unlock_irq(&n
->list_lock
);
1207 free_alien_cache(alien
);
1212 cpuup_canceled(cpu
);
1216 static int cpuup_callback(struct notifier_block
*nfb
,
1217 unsigned long action
, void *hcpu
)
1219 long cpu
= (long)hcpu
;
1223 case CPU_UP_PREPARE
:
1224 case CPU_UP_PREPARE_FROZEN
:
1225 mutex_lock(&slab_mutex
);
1226 err
= cpuup_prepare(cpu
);
1227 mutex_unlock(&slab_mutex
);
1230 case CPU_ONLINE_FROZEN
:
1231 start_cpu_timer(cpu
);
1233 #ifdef CONFIG_HOTPLUG_CPU
1234 case CPU_DOWN_PREPARE
:
1235 case CPU_DOWN_PREPARE_FROZEN
:
1237 * Shutdown cache reaper. Note that the slab_mutex is
1238 * held so that if cache_reap() is invoked it cannot do
1239 * anything expensive but will only modify reap_work
1240 * and reschedule the timer.
1242 cancel_delayed_work_sync(&per_cpu(slab_reap_work
, cpu
));
1243 /* Now the cache_reaper is guaranteed to be not running. */
1244 per_cpu(slab_reap_work
, cpu
).work
.func
= NULL
;
1246 case CPU_DOWN_FAILED
:
1247 case CPU_DOWN_FAILED_FROZEN
:
1248 start_cpu_timer(cpu
);
1251 case CPU_DEAD_FROZEN
:
1253 * Even if all the cpus of a node are down, we don't free the
1254 * kmem_cache_node of any cache. This to avoid a race between
1255 * cpu_down, and a kmalloc allocation from another cpu for
1256 * memory from the node of the cpu going down. The node
1257 * structure is usually allocated from kmem_cache_create() and
1258 * gets destroyed at kmem_cache_destroy().
1262 case CPU_UP_CANCELED
:
1263 case CPU_UP_CANCELED_FROZEN
:
1264 mutex_lock(&slab_mutex
);
1265 cpuup_canceled(cpu
);
1266 mutex_unlock(&slab_mutex
);
1269 return notifier_from_errno(err
);
1272 static struct notifier_block cpucache_notifier
= {
1273 &cpuup_callback
, NULL
, 0
1276 #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
1278 * Drains freelist for a node on each slab cache, used for memory hot-remove.
1279 * Returns -EBUSY if all objects cannot be drained so that the node is not
1282 * Must hold slab_mutex.
1284 static int __meminit
drain_cache_node_node(int node
)
1286 struct kmem_cache
*cachep
;
1289 list_for_each_entry(cachep
, &slab_caches
, list
) {
1290 struct kmem_cache_node
*n
;
1292 n
= get_node(cachep
, node
);
1296 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
1298 if (!list_empty(&n
->slabs_full
) ||
1299 !list_empty(&n
->slabs_partial
)) {
1307 static int __meminit
slab_memory_callback(struct notifier_block
*self
,
1308 unsigned long action
, void *arg
)
1310 struct memory_notify
*mnb
= arg
;
1314 nid
= mnb
->status_change_nid
;
1319 case MEM_GOING_ONLINE
:
1320 mutex_lock(&slab_mutex
);
1321 ret
= init_cache_node_node(nid
);
1322 mutex_unlock(&slab_mutex
);
1324 case MEM_GOING_OFFLINE
:
1325 mutex_lock(&slab_mutex
);
1326 ret
= drain_cache_node_node(nid
);
1327 mutex_unlock(&slab_mutex
);
1331 case MEM_CANCEL_ONLINE
:
1332 case MEM_CANCEL_OFFLINE
:
1336 return notifier_from_errno(ret
);
1338 #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
1341 * swap the static kmem_cache_node with kmalloced memory
1343 static void __init
init_list(struct kmem_cache
*cachep
, struct kmem_cache_node
*list
,
1346 struct kmem_cache_node
*ptr
;
1348 ptr
= kmalloc_node(sizeof(struct kmem_cache_node
), GFP_NOWAIT
, nodeid
);
1351 memcpy(ptr
, list
, sizeof(struct kmem_cache_node
));
1353 * Do not assume that spinlocks can be initialized via memcpy:
1355 spin_lock_init(&ptr
->list_lock
);
1357 MAKE_ALL_LISTS(cachep
, ptr
, nodeid
);
1358 cachep
->node
[nodeid
] = ptr
;
1362 * For setting up all the kmem_cache_node for cache whose buffer_size is same as
1363 * size of kmem_cache_node.
1365 static void __init
set_up_node(struct kmem_cache
*cachep
, int index
)
1369 for_each_online_node(node
) {
1370 cachep
->node
[node
] = &init_kmem_cache_node
[index
+ node
];
1371 cachep
->node
[node
]->next_reap
= jiffies
+
1373 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
1378 * Initialisation. Called after the page allocator have been initialised and
1379 * before smp_init().
1381 void __init
kmem_cache_init(void)
1385 BUILD_BUG_ON(sizeof(((struct page
*)NULL
)->lru
) <
1386 sizeof(struct rcu_head
));
1387 kmem_cache
= &kmem_cache_boot
;
1389 if (num_possible_nodes() == 1)
1390 use_alien_caches
= 0;
1392 for (i
= 0; i
< NUM_INIT_LISTS
; i
++)
1393 kmem_cache_node_init(&init_kmem_cache_node
[i
]);
1396 * Fragmentation resistance on low memory - only use bigger
1397 * page orders on machines with more than 32MB of memory if
1398 * not overridden on the command line.
1400 if (!slab_max_order_set
&& totalram_pages
> (32 << 20) >> PAGE_SHIFT
)
1401 slab_max_order
= SLAB_MAX_ORDER_HI
;
1403 /* Bootstrap is tricky, because several objects are allocated
1404 * from caches that do not exist yet:
1405 * 1) initialize the kmem_cache cache: it contains the struct
1406 * kmem_cache structures of all caches, except kmem_cache itself:
1407 * kmem_cache is statically allocated.
1408 * Initially an __init data area is used for the head array and the
1409 * kmem_cache_node structures, it's replaced with a kmalloc allocated
1410 * array at the end of the bootstrap.
1411 * 2) Create the first kmalloc cache.
1412 * The struct kmem_cache for the new cache is allocated normally.
1413 * An __init data area is used for the head array.
1414 * 3) Create the remaining kmalloc caches, with minimally sized
1416 * 4) Replace the __init data head arrays for kmem_cache and the first
1417 * kmalloc cache with kmalloc allocated arrays.
1418 * 5) Replace the __init data for kmem_cache_node for kmem_cache and
1419 * the other cache's with kmalloc allocated memory.
1420 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1423 /* 1) create the kmem_cache */
1426 * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
1428 create_boot_cache(kmem_cache
, "kmem_cache",
1429 offsetof(struct kmem_cache
, node
) +
1430 nr_node_ids
* sizeof(struct kmem_cache_node
*),
1431 SLAB_HWCACHE_ALIGN
);
1432 list_add(&kmem_cache
->list
, &slab_caches
);
1433 slab_state
= PARTIAL
;
1436 * Initialize the caches that provide memory for the kmem_cache_node
1437 * structures first. Without this, further allocations will bug.
1439 kmalloc_caches
[INDEX_NODE
] = create_kmalloc_cache("kmalloc-node",
1440 kmalloc_size(INDEX_NODE
), ARCH_KMALLOC_FLAGS
);
1441 slab_state
= PARTIAL_NODE
;
1442 setup_kmalloc_cache_index_table();
1444 slab_early_init
= 0;
1446 /* 5) Replace the bootstrap kmem_cache_node */
1450 for_each_online_node(nid
) {
1451 init_list(kmem_cache
, &init_kmem_cache_node
[CACHE_CACHE
+ nid
], nid
);
1453 init_list(kmalloc_caches
[INDEX_NODE
],
1454 &init_kmem_cache_node
[SIZE_NODE
+ nid
], nid
);
1458 create_kmalloc_caches(ARCH_KMALLOC_FLAGS
);
1461 void __init
kmem_cache_init_late(void)
1463 struct kmem_cache
*cachep
;
1467 /* 6) resize the head arrays to their final sizes */
1468 mutex_lock(&slab_mutex
);
1469 list_for_each_entry(cachep
, &slab_caches
, list
)
1470 if (enable_cpucache(cachep
, GFP_NOWAIT
))
1472 mutex_unlock(&slab_mutex
);
1478 * Register a cpu startup notifier callback that initializes
1479 * cpu_cache_get for all new cpus
1481 register_cpu_notifier(&cpucache_notifier
);
1485 * Register a memory hotplug callback that initializes and frees
1488 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
1492 * The reap timers are started later, with a module init call: That part
1493 * of the kernel is not yet operational.
1497 static int __init
cpucache_init(void)
1502 * Register the timers that return unneeded pages to the page allocator
1504 for_each_online_cpu(cpu
)
1505 start_cpu_timer(cpu
);
1511 __initcall(cpucache_init
);
1513 static noinline
void
1514 slab_out_of_memory(struct kmem_cache
*cachep
, gfp_t gfpflags
, int nodeid
)
1517 struct kmem_cache_node
*n
;
1519 unsigned long flags
;
1521 static DEFINE_RATELIMIT_STATE(slab_oom_rs
, DEFAULT_RATELIMIT_INTERVAL
,
1522 DEFAULT_RATELIMIT_BURST
);
1524 if ((gfpflags
& __GFP_NOWARN
) || !__ratelimit(&slab_oom_rs
))
1528 "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n",
1530 printk(KERN_WARNING
" cache: %s, object size: %d, order: %d\n",
1531 cachep
->name
, cachep
->size
, cachep
->gfporder
);
1533 for_each_kmem_cache_node(cachep
, node
, n
) {
1534 unsigned long active_objs
= 0, num_objs
= 0, free_objects
= 0;
1535 unsigned long active_slabs
= 0, num_slabs
= 0;
1537 spin_lock_irqsave(&n
->list_lock
, flags
);
1538 list_for_each_entry(page
, &n
->slabs_full
, lru
) {
1539 active_objs
+= cachep
->num
;
1542 list_for_each_entry(page
, &n
->slabs_partial
, lru
) {
1543 active_objs
+= page
->active
;
1546 list_for_each_entry(page
, &n
->slabs_free
, lru
)
1549 free_objects
+= n
->free_objects
;
1550 spin_unlock_irqrestore(&n
->list_lock
, flags
);
1552 num_slabs
+= active_slabs
;
1553 num_objs
= num_slabs
* cachep
->num
;
1555 " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n",
1556 node
, active_slabs
, num_slabs
, active_objs
, num_objs
,
1563 * Interface to system's page allocator. No need to hold the
1564 * kmem_cache_node ->list_lock.
1566 * If we requested dmaable memory, we will get it. Even if we
1567 * did not request dmaable memory, we might get it, but that
1568 * would be relatively rare and ignorable.
1570 static struct page
*kmem_getpages(struct kmem_cache
*cachep
, gfp_t flags
,
1576 flags
|= cachep
->allocflags
;
1577 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1578 flags
|= __GFP_RECLAIMABLE
;
1580 page
= __alloc_pages_node(nodeid
, flags
| __GFP_NOTRACK
, cachep
->gfporder
);
1582 slab_out_of_memory(cachep
, flags
, nodeid
);
1586 if (memcg_charge_slab(page
, flags
, cachep
->gfporder
, cachep
)) {
1587 __free_pages(page
, cachep
->gfporder
);
1591 /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
1592 if (page_is_pfmemalloc(page
))
1593 pfmemalloc_active
= true;
1595 nr_pages
= (1 << cachep
->gfporder
);
1596 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1597 add_zone_page_state(page_zone(page
),
1598 NR_SLAB_RECLAIMABLE
, nr_pages
);
1600 add_zone_page_state(page_zone(page
),
1601 NR_SLAB_UNRECLAIMABLE
, nr_pages
);
1602 __SetPageSlab(page
);
1603 if (page_is_pfmemalloc(page
))
1604 SetPageSlabPfmemalloc(page
);
1606 if (kmemcheck_enabled
&& !(cachep
->flags
& SLAB_NOTRACK
)) {
1607 kmemcheck_alloc_shadow(page
, cachep
->gfporder
, flags
, nodeid
);
1610 kmemcheck_mark_uninitialized_pages(page
, nr_pages
);
1612 kmemcheck_mark_unallocated_pages(page
, nr_pages
);
1619 * Interface to system's page release.
1621 static void kmem_freepages(struct kmem_cache
*cachep
, struct page
*page
)
1623 const unsigned long nr_freed
= (1 << cachep
->gfporder
);
1625 kmemcheck_free_shadow(page
, cachep
->gfporder
);
1627 if (cachep
->flags
& SLAB_RECLAIM_ACCOUNT
)
1628 sub_zone_page_state(page_zone(page
),
1629 NR_SLAB_RECLAIMABLE
, nr_freed
);
1631 sub_zone_page_state(page_zone(page
),
1632 NR_SLAB_UNRECLAIMABLE
, nr_freed
);
1634 BUG_ON(!PageSlab(page
));
1635 __ClearPageSlabPfmemalloc(page
);
1636 __ClearPageSlab(page
);
1637 page_mapcount_reset(page
);
1638 page
->mapping
= NULL
;
1640 if (current
->reclaim_state
)
1641 current
->reclaim_state
->reclaimed_slab
+= nr_freed
;
1642 __free_kmem_pages(page
, cachep
->gfporder
);
1645 static void kmem_rcu_free(struct rcu_head
*head
)
1647 struct kmem_cache
*cachep
;
1650 page
= container_of(head
, struct page
, rcu_head
);
1651 cachep
= page
->slab_cache
;
1653 kmem_freepages(cachep
, page
);
1657 static bool is_debug_pagealloc_cache(struct kmem_cache
*cachep
)
1659 if (debug_pagealloc_enabled() && OFF_SLAB(cachep
) &&
1660 (cachep
->size
% PAGE_SIZE
) == 0)
1666 #ifdef CONFIG_DEBUG_PAGEALLOC
1667 static void store_stackinfo(struct kmem_cache
*cachep
, unsigned long *addr
,
1668 unsigned long caller
)
1670 int size
= cachep
->object_size
;
1672 addr
= (unsigned long *)&((char *)addr
)[obj_offset(cachep
)];
1674 if (size
< 5 * sizeof(unsigned long))
1677 *addr
++ = 0x12345678;
1679 *addr
++ = smp_processor_id();
1680 size
-= 3 * sizeof(unsigned long);
1682 unsigned long *sptr
= &caller
;
1683 unsigned long svalue
;
1685 while (!kstack_end(sptr
)) {
1687 if (kernel_text_address(svalue
)) {
1689 size
-= sizeof(unsigned long);
1690 if (size
<= sizeof(unsigned long))
1696 *addr
++ = 0x87654321;
1699 static void slab_kernel_map(struct kmem_cache
*cachep
, void *objp
,
1700 int map
, unsigned long caller
)
1702 if (!is_debug_pagealloc_cache(cachep
))
1706 store_stackinfo(cachep
, objp
, caller
);
1708 kernel_map_pages(virt_to_page(objp
), cachep
->size
/ PAGE_SIZE
, map
);
1712 static inline void slab_kernel_map(struct kmem_cache
*cachep
, void *objp
,
1713 int map
, unsigned long caller
) {}
1717 static void poison_obj(struct kmem_cache
*cachep
, void *addr
, unsigned char val
)
1719 int size
= cachep
->object_size
;
1720 addr
= &((char *)addr
)[obj_offset(cachep
)];
1722 memset(addr
, val
, size
);
1723 *(unsigned char *)(addr
+ size
- 1) = POISON_END
;
1726 static void dump_line(char *data
, int offset
, int limit
)
1729 unsigned char error
= 0;
1732 printk(KERN_ERR
"%03x: ", offset
);
1733 for (i
= 0; i
< limit
; i
++) {
1734 if (data
[offset
+ i
] != POISON_FREE
) {
1735 error
= data
[offset
+ i
];
1739 print_hex_dump(KERN_CONT
, "", 0, 16, 1,
1740 &data
[offset
], limit
, 1);
1742 if (bad_count
== 1) {
1743 error
^= POISON_FREE
;
1744 if (!(error
& (error
- 1))) {
1745 printk(KERN_ERR
"Single bit error detected. Probably bad RAM.\n");
1747 printk(KERN_ERR
"Run memtest86+ or a similar memory test tool.\n");
1749 printk(KERN_ERR
"Run a memory test tool.\n");
1758 static void print_objinfo(struct kmem_cache
*cachep
, void *objp
, int lines
)
1763 if (cachep
->flags
& SLAB_RED_ZONE
) {
1764 printk(KERN_ERR
"Redzone: 0x%llx/0x%llx.\n",
1765 *dbg_redzone1(cachep
, objp
),
1766 *dbg_redzone2(cachep
, objp
));
1769 if (cachep
->flags
& SLAB_STORE_USER
) {
1770 printk(KERN_ERR
"Last user: [<%p>](%pSR)\n",
1771 *dbg_userword(cachep
, objp
),
1772 *dbg_userword(cachep
, objp
));
1774 realobj
= (char *)objp
+ obj_offset(cachep
);
1775 size
= cachep
->object_size
;
1776 for (i
= 0; i
< size
&& lines
; i
+= 16, lines
--) {
1779 if (i
+ limit
> size
)
1781 dump_line(realobj
, i
, limit
);
1785 static void check_poison_obj(struct kmem_cache
*cachep
, void *objp
)
1791 if (is_debug_pagealloc_cache(cachep
))
1794 realobj
= (char *)objp
+ obj_offset(cachep
);
1795 size
= cachep
->object_size
;
1797 for (i
= 0; i
< size
; i
++) {
1798 char exp
= POISON_FREE
;
1801 if (realobj
[i
] != exp
) {
1807 "Slab corruption (%s): %s start=%p, len=%d\n",
1808 print_tainted(), cachep
->name
, realobj
, size
);
1809 print_objinfo(cachep
, objp
, 0);
1811 /* Hexdump the affected line */
1814 if (i
+ limit
> size
)
1816 dump_line(realobj
, i
, limit
);
1819 /* Limit to 5 lines */
1825 /* Print some data about the neighboring objects, if they
1828 struct page
*page
= virt_to_head_page(objp
);
1831 objnr
= obj_to_index(cachep
, page
, objp
);
1833 objp
= index_to_obj(cachep
, page
, objnr
- 1);
1834 realobj
= (char *)objp
+ obj_offset(cachep
);
1835 printk(KERN_ERR
"Prev obj: start=%p, len=%d\n",
1837 print_objinfo(cachep
, objp
, 2);
1839 if (objnr
+ 1 < cachep
->num
) {
1840 objp
= index_to_obj(cachep
, page
, objnr
+ 1);
1841 realobj
= (char *)objp
+ obj_offset(cachep
);
1842 printk(KERN_ERR
"Next obj: start=%p, len=%d\n",
1844 print_objinfo(cachep
, objp
, 2);
1851 static void slab_destroy_debugcheck(struct kmem_cache
*cachep
,
1855 for (i
= 0; i
< cachep
->num
; i
++) {
1856 void *objp
= index_to_obj(cachep
, page
, i
);
1858 if (cachep
->flags
& SLAB_POISON
) {
1859 check_poison_obj(cachep
, objp
);
1860 slab_kernel_map(cachep
, objp
, 1, 0);
1862 if (cachep
->flags
& SLAB_RED_ZONE
) {
1863 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
1864 slab_error(cachep
, "start of a freed object was overwritten");
1865 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
1866 slab_error(cachep
, "end of a freed object was overwritten");
1871 static void slab_destroy_debugcheck(struct kmem_cache
*cachep
,
1878 * slab_destroy - destroy and release all objects in a slab
1879 * @cachep: cache pointer being destroyed
1880 * @page: page pointer being destroyed
1882 * Destroy all the objs in a slab page, and release the mem back to the system.
1883 * Before calling the slab page must have been unlinked from the cache. The
1884 * kmem_cache_node ->list_lock is not held/needed.
1886 static void slab_destroy(struct kmem_cache
*cachep
, struct page
*page
)
1890 freelist
= page
->freelist
;
1891 slab_destroy_debugcheck(cachep
, page
);
1892 if (unlikely(cachep
->flags
& SLAB_DESTROY_BY_RCU
))
1893 call_rcu(&page
->rcu_head
, kmem_rcu_free
);
1895 kmem_freepages(cachep
, page
);
1898 * From now on, we don't use freelist
1899 * although actual page can be freed in rcu context
1901 if (OFF_SLAB(cachep
))
1902 kmem_cache_free(cachep
->freelist_cache
, freelist
);
1905 static void slabs_destroy(struct kmem_cache
*cachep
, struct list_head
*list
)
1907 struct page
*page
, *n
;
1909 list_for_each_entry_safe(page
, n
, list
, lru
) {
1910 list_del(&page
->lru
);
1911 slab_destroy(cachep
, page
);
1916 * calculate_slab_order - calculate size (page order) of slabs
1917 * @cachep: pointer to the cache that is being created
1918 * @size: size of objects to be created in this cache.
1919 * @align: required alignment for the objects.
1920 * @flags: slab allocation flags
1922 * Also calculates the number of objects per slab.
1924 * This could be made much more intelligent. For now, try to avoid using
1925 * high order pages for slabs. When the gfp() functions are more friendly
1926 * towards high-order requests, this should be changed.
1928 static size_t calculate_slab_order(struct kmem_cache
*cachep
,
1929 size_t size
, size_t align
, unsigned long flags
)
1931 unsigned long offslab_limit
;
1932 size_t left_over
= 0;
1935 for (gfporder
= 0; gfporder
<= KMALLOC_MAX_ORDER
; gfporder
++) {
1939 cache_estimate(gfporder
, size
, align
, flags
, &remainder
, &num
);
1943 /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
1944 if (num
> SLAB_OBJ_MAX_NUM
)
1947 if (flags
& CFLGS_OFF_SLAB
) {
1949 * Max number of objs-per-slab for caches which
1950 * use off-slab slabs. Needed to avoid a possible
1951 * looping condition in cache_grow().
1953 offslab_limit
= size
;
1954 offslab_limit
/= sizeof(freelist_idx_t
);
1956 if (num
> offslab_limit
)
1960 /* Found something acceptable - save it away */
1962 cachep
->gfporder
= gfporder
;
1963 left_over
= remainder
;
1966 * A VFS-reclaimable slab tends to have most allocations
1967 * as GFP_NOFS and we really don't want to have to be allocating
1968 * higher-order pages when we are unable to shrink dcache.
1970 if (flags
& SLAB_RECLAIM_ACCOUNT
)
1974 * Large number of objects is good, but very large slabs are
1975 * currently bad for the gfp()s.
1977 if (gfporder
>= slab_max_order
)
1981 * Acceptable internal fragmentation?
1983 if (left_over
* 8 <= (PAGE_SIZE
<< gfporder
))
1989 static struct array_cache __percpu
*alloc_kmem_cache_cpus(
1990 struct kmem_cache
*cachep
, int entries
, int batchcount
)
1994 struct array_cache __percpu
*cpu_cache
;
1996 size
= sizeof(void *) * entries
+ sizeof(struct array_cache
);
1997 cpu_cache
= __alloc_percpu(size
, sizeof(void *));
2002 for_each_possible_cpu(cpu
) {
2003 init_arraycache(per_cpu_ptr(cpu_cache
, cpu
),
2004 entries
, batchcount
);
2010 static int __init_refok
setup_cpu_cache(struct kmem_cache
*cachep
, gfp_t gfp
)
2012 if (slab_state
>= FULL
)
2013 return enable_cpucache(cachep
, gfp
);
2015 cachep
->cpu_cache
= alloc_kmem_cache_cpus(cachep
, 1, 1);
2016 if (!cachep
->cpu_cache
)
2019 if (slab_state
== DOWN
) {
2020 /* Creation of first cache (kmem_cache). */
2021 set_up_node(kmem_cache
, CACHE_CACHE
);
2022 } else if (slab_state
== PARTIAL
) {
2023 /* For kmem_cache_node */
2024 set_up_node(cachep
, SIZE_NODE
);
2028 for_each_online_node(node
) {
2029 cachep
->node
[node
] = kmalloc_node(
2030 sizeof(struct kmem_cache_node
), gfp
, node
);
2031 BUG_ON(!cachep
->node
[node
]);
2032 kmem_cache_node_init(cachep
->node
[node
]);
2036 cachep
->node
[numa_mem_id()]->next_reap
=
2037 jiffies
+ REAPTIMEOUT_NODE
+
2038 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
2040 cpu_cache_get(cachep
)->avail
= 0;
2041 cpu_cache_get(cachep
)->limit
= BOOT_CPUCACHE_ENTRIES
;
2042 cpu_cache_get(cachep
)->batchcount
= 1;
2043 cpu_cache_get(cachep
)->touched
= 0;
2044 cachep
->batchcount
= 1;
2045 cachep
->limit
= BOOT_CPUCACHE_ENTRIES
;
2049 unsigned long kmem_cache_flags(unsigned long object_size
,
2050 unsigned long flags
, const char *name
,
2051 void (*ctor
)(void *))
2057 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
2058 unsigned long flags
, void (*ctor
)(void *))
2060 struct kmem_cache
*cachep
;
2062 cachep
= find_mergeable(size
, align
, flags
, name
, ctor
);
2067 * Adjust the object sizes so that we clear
2068 * the complete object on kzalloc.
2070 cachep
->object_size
= max_t(int, cachep
->object_size
, size
);
2076 * __kmem_cache_create - Create a cache.
2077 * @cachep: cache management descriptor
2078 * @flags: SLAB flags
2080 * Returns a ptr to the cache on success, NULL on failure.
2081 * Cannot be called within a int, but can be interrupted.
2082 * The @ctor is run when new pages are allocated by the cache.
2086 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2087 * to catch references to uninitialised memory.
2089 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2090 * for buffer overruns.
2092 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2093 * cacheline. This can be beneficial if you're counting cycles as closely
2097 __kmem_cache_create (struct kmem_cache
*cachep
, unsigned long flags
)
2099 size_t left_over
, freelist_size
;
2100 size_t ralign
= BYTES_PER_WORD
;
2103 size_t size
= cachep
->size
;
2108 * Enable redzoning and last user accounting, except for caches with
2109 * large objects, if the increased size would increase the object size
2110 * above the next power of two: caches with object sizes just above a
2111 * power of two have a significant amount of internal fragmentation.
2113 if (size
< 4096 || fls(size
- 1) == fls(size
-1 + REDZONE_ALIGN
+
2114 2 * sizeof(unsigned long long)))
2115 flags
|= SLAB_RED_ZONE
| SLAB_STORE_USER
;
2116 if (!(flags
& SLAB_DESTROY_BY_RCU
))
2117 flags
|= SLAB_POISON
;
2119 if (flags
& SLAB_DESTROY_BY_RCU
)
2120 BUG_ON(flags
& SLAB_POISON
);
2124 * Check that size is in terms of words. This is needed to avoid
2125 * unaligned accesses for some archs when redzoning is used, and makes
2126 * sure any on-slab bufctl's are also correctly aligned.
2128 if (size
& (BYTES_PER_WORD
- 1)) {
2129 size
+= (BYTES_PER_WORD
- 1);
2130 size
&= ~(BYTES_PER_WORD
- 1);
2133 if (flags
& SLAB_RED_ZONE
) {
2134 ralign
= REDZONE_ALIGN
;
2135 /* If redzoning, ensure that the second redzone is suitably
2136 * aligned, by adjusting the object size accordingly. */
2137 size
+= REDZONE_ALIGN
- 1;
2138 size
&= ~(REDZONE_ALIGN
- 1);
2141 /* 3) caller mandated alignment */
2142 if (ralign
< cachep
->align
) {
2143 ralign
= cachep
->align
;
2145 /* disable debug if necessary */
2146 if (ralign
> __alignof__(unsigned long long))
2147 flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2151 cachep
->align
= ralign
;
2153 if (slab_is_available())
2161 * Both debugging options require word-alignment which is calculated
2164 if (flags
& SLAB_RED_ZONE
) {
2165 /* add space for red zone words */
2166 cachep
->obj_offset
+= sizeof(unsigned long long);
2167 size
+= 2 * sizeof(unsigned long long);
2169 if (flags
& SLAB_STORE_USER
) {
2170 /* user store requires one word storage behind the end of
2171 * the real object. But if the second red zone needs to be
2172 * aligned to 64 bits, we must allow that much space.
2174 if (flags
& SLAB_RED_ZONE
)
2175 size
+= REDZONE_ALIGN
;
2177 size
+= BYTES_PER_WORD
;
2181 kasan_cache_create(cachep
, &size
, &flags
);
2183 size
= ALIGN(size
, cachep
->align
);
2185 * We should restrict the number of objects in a slab to implement
2186 * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
2188 if (FREELIST_BYTE_INDEX
&& size
< SLAB_OBJ_MIN_SIZE
)
2189 size
= ALIGN(SLAB_OBJ_MIN_SIZE
, cachep
->align
);
2193 * To activate debug pagealloc, off-slab management is necessary
2194 * requirement. In early phase of initialization, small sized slab
2195 * doesn't get initialized so it would not be possible. So, we need
2196 * to check size >= 256. It guarantees that all necessary small
2197 * sized slab is initialized in current slab initialization sequence.
2199 if (debug_pagealloc_enabled() && (flags
& SLAB_POISON
) &&
2200 !slab_early_init
&& size
>= kmalloc_size(INDEX_NODE
) &&
2201 size
>= 256 && cachep
->object_size
> cache_line_size() &&
2203 cachep
->obj_offset
+= PAGE_SIZE
- size
;
2209 * Determine if the slab management is 'on' or 'off' slab.
2210 * (bootstrapping cannot cope with offslab caches so don't do
2211 * it too early on. Always use on-slab management when
2212 * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak)
2214 if (size
>= OFF_SLAB_MIN_SIZE
&& !slab_early_init
&&
2215 !(flags
& SLAB_NOLEAKTRACE
)) {
2217 * Size is large, assume best to place the slab management obj
2218 * off-slab (should allow better packing of objs).
2220 flags
|= CFLGS_OFF_SLAB
;
2223 left_over
= calculate_slab_order(cachep
, size
, cachep
->align
, flags
);
2228 freelist_size
= calculate_freelist_size(cachep
->num
, cachep
->align
);
2231 * If the slab has been placed off-slab, and we have enough space then
2232 * move it on-slab. This is at the expense of any extra colouring.
2234 if (flags
& CFLGS_OFF_SLAB
&& left_over
>= freelist_size
) {
2235 flags
&= ~CFLGS_OFF_SLAB
;
2236 left_over
-= freelist_size
;
2239 if (flags
& CFLGS_OFF_SLAB
) {
2240 /* really off slab. No need for manual alignment */
2241 freelist_size
= calculate_freelist_size(cachep
->num
, 0);
2244 cachep
->colour_off
= cache_line_size();
2245 /* Offset must be a multiple of the alignment. */
2246 if (cachep
->colour_off
< cachep
->align
)
2247 cachep
->colour_off
= cachep
->align
;
2248 cachep
->colour
= left_over
/ cachep
->colour_off
;
2249 cachep
->freelist_size
= freelist_size
;
2250 cachep
->flags
= flags
;
2251 cachep
->allocflags
= __GFP_COMP
;
2252 if (CONFIG_ZONE_DMA_FLAG
&& (flags
& SLAB_CACHE_DMA
))
2253 cachep
->allocflags
|= GFP_DMA
;
2254 cachep
->size
= size
;
2255 cachep
->reciprocal_buffer_size
= reciprocal_value(size
);
2259 * If we're going to use the generic kernel_map_pages()
2260 * poisoning, then it's going to smash the contents of
2261 * the redzone and userword anyhow, so switch them off.
2263 if (IS_ENABLED(CONFIG_PAGE_POISONING
) &&
2264 (cachep
->flags
& SLAB_POISON
) &&
2265 is_debug_pagealloc_cache(cachep
))
2266 cachep
->flags
&= ~(SLAB_RED_ZONE
| SLAB_STORE_USER
);
2269 if (OFF_SLAB(cachep
)) {
2270 cachep
->freelist_cache
= kmalloc_slab(freelist_size
, 0u);
2272 * This is a possibility for one of the kmalloc_{dma,}_caches.
2273 * But since we go off slab only for object size greater than
2274 * OFF_SLAB_MIN_SIZE, and kmalloc_{dma,}_caches get created
2275 * in ascending order,this should not happen at all.
2276 * But leave a BUG_ON for some lucky dude.
2278 BUG_ON(ZERO_OR_NULL_PTR(cachep
->freelist_cache
));
2281 err
= setup_cpu_cache(cachep
, gfp
);
2283 __kmem_cache_shutdown(cachep
);
2291 static void check_irq_off(void)
2293 BUG_ON(!irqs_disabled());
2296 static void check_irq_on(void)
2298 BUG_ON(irqs_disabled());
2301 static void check_spinlock_acquired(struct kmem_cache
*cachep
)
2305 assert_spin_locked(&get_node(cachep
, numa_mem_id())->list_lock
);
2309 static void check_spinlock_acquired_node(struct kmem_cache
*cachep
, int node
)
2313 assert_spin_locked(&get_node(cachep
, node
)->list_lock
);
2318 #define check_irq_off() do { } while(0)
2319 #define check_irq_on() do { } while(0)
2320 #define check_spinlock_acquired(x) do { } while(0)
2321 #define check_spinlock_acquired_node(x, y) do { } while(0)
2324 static void drain_array(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
,
2325 struct array_cache
*ac
,
2326 int force
, int node
);
2328 static void do_drain(void *arg
)
2330 struct kmem_cache
*cachep
= arg
;
2331 struct array_cache
*ac
;
2332 int node
= numa_mem_id();
2333 struct kmem_cache_node
*n
;
2337 ac
= cpu_cache_get(cachep
);
2338 n
= get_node(cachep
, node
);
2339 spin_lock(&n
->list_lock
);
2340 free_block(cachep
, ac
->entry
, ac
->avail
, node
, &list
);
2341 spin_unlock(&n
->list_lock
);
2342 slabs_destroy(cachep
, &list
);
2346 static void drain_cpu_caches(struct kmem_cache
*cachep
)
2348 struct kmem_cache_node
*n
;
2351 on_each_cpu(do_drain
, cachep
, 1);
2353 for_each_kmem_cache_node(cachep
, node
, n
)
2355 drain_alien_cache(cachep
, n
->alien
);
2357 for_each_kmem_cache_node(cachep
, node
, n
)
2358 drain_array(cachep
, n
, n
->shared
, 1, node
);
2362 * Remove slabs from the list of free slabs.
2363 * Specify the number of slabs to drain in tofree.
2365 * Returns the actual number of slabs released.
2367 static int drain_freelist(struct kmem_cache
*cache
,
2368 struct kmem_cache_node
*n
, int tofree
)
2370 struct list_head
*p
;
2375 while (nr_freed
< tofree
&& !list_empty(&n
->slabs_free
)) {
2377 spin_lock_irq(&n
->list_lock
);
2378 p
= n
->slabs_free
.prev
;
2379 if (p
== &n
->slabs_free
) {
2380 spin_unlock_irq(&n
->list_lock
);
2384 page
= list_entry(p
, struct page
, lru
);
2386 BUG_ON(page
->active
);
2388 list_del(&page
->lru
);
2390 * Safe to drop the lock. The slab is no longer linked
2393 n
->free_objects
-= cache
->num
;
2394 spin_unlock_irq(&n
->list_lock
);
2395 slab_destroy(cache
, page
);
2402 int __kmem_cache_shrink(struct kmem_cache
*cachep
, bool deactivate
)
2406 struct kmem_cache_node
*n
;
2408 drain_cpu_caches(cachep
);
2411 for_each_kmem_cache_node(cachep
, node
, n
) {
2412 drain_freelist(cachep
, n
, slabs_tofree(cachep
, n
));
2414 ret
+= !list_empty(&n
->slabs_full
) ||
2415 !list_empty(&n
->slabs_partial
);
2417 return (ret
? 1 : 0);
2420 int __kmem_cache_shutdown(struct kmem_cache
*cachep
)
2423 struct kmem_cache_node
*n
;
2424 int rc
= __kmem_cache_shrink(cachep
, false);
2429 free_percpu(cachep
->cpu_cache
);
2431 /* NUMA: free the node structures */
2432 for_each_kmem_cache_node(cachep
, i
, n
) {
2434 free_alien_cache(n
->alien
);
2436 cachep
->node
[i
] = NULL
;
2442 * Get the memory for a slab management obj.
2444 * For a slab cache when the slab descriptor is off-slab, the
2445 * slab descriptor can't come from the same cache which is being created,
2446 * Because if it is the case, that means we defer the creation of
2447 * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
2448 * And we eventually call down to __kmem_cache_create(), which
2449 * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
2450 * This is a "chicken-and-egg" problem.
2452 * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
2453 * which are all initialized during kmem_cache_init().
2455 static void *alloc_slabmgmt(struct kmem_cache
*cachep
,
2456 struct page
*page
, int colour_off
,
2457 gfp_t local_flags
, int nodeid
)
2460 void *addr
= page_address(page
);
2462 if (OFF_SLAB(cachep
)) {
2463 /* Slab management obj is off-slab. */
2464 freelist
= kmem_cache_alloc_node(cachep
->freelist_cache
,
2465 local_flags
, nodeid
);
2469 freelist
= addr
+ colour_off
;
2470 colour_off
+= cachep
->freelist_size
;
2473 page
->s_mem
= addr
+ colour_off
;
2477 static inline freelist_idx_t
get_free_obj(struct page
*page
, unsigned int idx
)
2479 return ((freelist_idx_t
*)page
->freelist
)[idx
];
2482 static inline void set_free_obj(struct page
*page
,
2483 unsigned int idx
, freelist_idx_t val
)
2485 ((freelist_idx_t
*)(page
->freelist
))[idx
] = val
;
2488 static void cache_init_objs_debug(struct kmem_cache
*cachep
, struct page
*page
)
2493 for (i
= 0; i
< cachep
->num
; i
++) {
2494 void *objp
= index_to_obj(cachep
, page
, i
);
2495 kasan_init_slab_obj(cachep
, objp
);
2496 if (cachep
->flags
& SLAB_STORE_USER
)
2497 *dbg_userword(cachep
, objp
) = NULL
;
2499 if (cachep
->flags
& SLAB_RED_ZONE
) {
2500 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2501 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2504 * Constructors are not allowed to allocate memory from the same
2505 * cache which they are a constructor for. Otherwise, deadlock.
2506 * They must also be threaded.
2508 if (cachep
->ctor
&& !(cachep
->flags
& SLAB_POISON
)) {
2509 kasan_unpoison_object_data(cachep
,
2510 objp
+ obj_offset(cachep
));
2511 cachep
->ctor(objp
+ obj_offset(cachep
));
2512 kasan_poison_object_data(
2513 cachep
, objp
+ obj_offset(cachep
));
2516 if (cachep
->flags
& SLAB_RED_ZONE
) {
2517 if (*dbg_redzone2(cachep
, objp
) != RED_INACTIVE
)
2518 slab_error(cachep
, "constructor overwrote the end of an object");
2519 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
)
2520 slab_error(cachep
, "constructor overwrote the start of an object");
2522 /* need to poison the objs? */
2523 if (cachep
->flags
& SLAB_POISON
) {
2524 poison_obj(cachep
, objp
, POISON_FREE
);
2525 slab_kernel_map(cachep
, objp
, 0, 0);
2531 static void cache_init_objs(struct kmem_cache
*cachep
,
2537 cache_init_objs_debug(cachep
, page
);
2539 for (i
= 0; i
< cachep
->num
; i
++) {
2540 /* constructor could break poison info */
2541 if (DEBUG
== 0 && cachep
->ctor
) {
2542 objp
= index_to_obj(cachep
, page
, i
);
2543 kasan_unpoison_object_data(cachep
, objp
);
2545 kasan_poison_object_data(cachep
, objp
);
2548 set_free_obj(page
, i
, i
);
2552 static void kmem_flagcheck(struct kmem_cache
*cachep
, gfp_t flags
)
2554 if (CONFIG_ZONE_DMA_FLAG
) {
2555 if (flags
& GFP_DMA
)
2556 BUG_ON(!(cachep
->allocflags
& GFP_DMA
));
2558 BUG_ON(cachep
->allocflags
& GFP_DMA
);
2562 static void *slab_get_obj(struct kmem_cache
*cachep
, struct page
*page
,
2567 objp
= index_to_obj(cachep
, page
, get_free_obj(page
, page
->active
));
2570 WARN_ON(page_to_nid(virt_to_page(objp
)) != nodeid
);
2574 if (cachep
->flags
& SLAB_STORE_USER
)
2575 set_store_user_dirty(cachep
);
2581 static void slab_put_obj(struct kmem_cache
*cachep
, struct page
*page
,
2582 void *objp
, int nodeid
)
2584 unsigned int objnr
= obj_to_index(cachep
, page
, objp
);
2588 /* Verify that the slab belongs to the intended node */
2589 WARN_ON(page_to_nid(virt_to_page(objp
)) != nodeid
);
2591 /* Verify double free bug */
2592 for (i
= page
->active
; i
< cachep
->num
; i
++) {
2593 if (get_free_obj(page
, i
) == objnr
) {
2594 printk(KERN_ERR
"slab: double free detected in cache '%s', objp %p\n",
2595 cachep
->name
, objp
);
2601 set_free_obj(page
, page
->active
, objnr
);
2605 * Map pages beginning at addr to the given cache and slab. This is required
2606 * for the slab allocator to be able to lookup the cache and slab of a
2607 * virtual address for kfree, ksize, and slab debugging.
2609 static void slab_map_pages(struct kmem_cache
*cache
, struct page
*page
,
2612 page
->slab_cache
= cache
;
2613 page
->freelist
= freelist
;
2617 * Grow (by 1) the number of slabs within a cache. This is called by
2618 * kmem_cache_alloc() when there are no active objs left in a cache.
2620 static int cache_grow(struct kmem_cache
*cachep
,
2621 gfp_t flags
, int nodeid
, struct page
*page
)
2626 struct kmem_cache_node
*n
;
2629 * Be lazy and only check for valid flags here, keeping it out of the
2630 * critical path in kmem_cache_alloc().
2632 if (unlikely(flags
& GFP_SLAB_BUG_MASK
)) {
2633 pr_emerg("gfp: %u\n", flags
& GFP_SLAB_BUG_MASK
);
2636 local_flags
= flags
& (GFP_CONSTRAINT_MASK
|GFP_RECLAIM_MASK
);
2638 /* Take the node list lock to change the colour_next on this node */
2640 n
= get_node(cachep
, nodeid
);
2641 spin_lock(&n
->list_lock
);
2643 /* Get colour for the slab, and cal the next value. */
2644 offset
= n
->colour_next
;
2646 if (n
->colour_next
>= cachep
->colour
)
2648 spin_unlock(&n
->list_lock
);
2650 offset
*= cachep
->colour_off
;
2652 if (gfpflags_allow_blocking(local_flags
))
2656 * The test for missing atomic flag is performed here, rather than
2657 * the more obvious place, simply to reduce the critical path length
2658 * in kmem_cache_alloc(). If a caller is seriously mis-behaving they
2659 * will eventually be caught here (where it matters).
2661 kmem_flagcheck(cachep
, flags
);
2664 * Get mem for the objs. Attempt to allocate a physical page from
2668 page
= kmem_getpages(cachep
, local_flags
, nodeid
);
2672 /* Get slab management. */
2673 freelist
= alloc_slabmgmt(cachep
, page
, offset
,
2674 local_flags
& ~GFP_CONSTRAINT_MASK
, nodeid
);
2678 slab_map_pages(cachep
, page
, freelist
);
2680 kasan_poison_slab(page
);
2681 cache_init_objs(cachep
, page
);
2683 if (gfpflags_allow_blocking(local_flags
))
2684 local_irq_disable();
2686 spin_lock(&n
->list_lock
);
2688 /* Make slab active. */
2689 list_add_tail(&page
->lru
, &(n
->slabs_free
));
2690 STATS_INC_GROWN(cachep
);
2691 n
->free_objects
+= cachep
->num
;
2692 spin_unlock(&n
->list_lock
);
2695 kmem_freepages(cachep
, page
);
2697 if (gfpflags_allow_blocking(local_flags
))
2698 local_irq_disable();
2705 * Perform extra freeing checks:
2706 * - detect bad pointers.
2707 * - POISON/RED_ZONE checking
2709 static void kfree_debugcheck(const void *objp
)
2711 if (!virt_addr_valid(objp
)) {
2712 printk(KERN_ERR
"kfree_debugcheck: out of range ptr %lxh.\n",
2713 (unsigned long)objp
);
2718 static inline void verify_redzone_free(struct kmem_cache
*cache
, void *obj
)
2720 unsigned long long redzone1
, redzone2
;
2722 redzone1
= *dbg_redzone1(cache
, obj
);
2723 redzone2
= *dbg_redzone2(cache
, obj
);
2728 if (redzone1
== RED_ACTIVE
&& redzone2
== RED_ACTIVE
)
2731 if (redzone1
== RED_INACTIVE
&& redzone2
== RED_INACTIVE
)
2732 slab_error(cache
, "double free detected");
2734 slab_error(cache
, "memory outside object was overwritten");
2736 printk(KERN_ERR
"%p: redzone 1:0x%llx, redzone 2:0x%llx.\n",
2737 obj
, redzone1
, redzone2
);
2740 static void *cache_free_debugcheck(struct kmem_cache
*cachep
, void *objp
,
2741 unsigned long caller
)
2746 BUG_ON(virt_to_cache(objp
) != cachep
);
2748 objp
-= obj_offset(cachep
);
2749 kfree_debugcheck(objp
);
2750 page
= virt_to_head_page(objp
);
2752 if (cachep
->flags
& SLAB_RED_ZONE
) {
2753 verify_redzone_free(cachep
, objp
);
2754 *dbg_redzone1(cachep
, objp
) = RED_INACTIVE
;
2755 *dbg_redzone2(cachep
, objp
) = RED_INACTIVE
;
2757 if (cachep
->flags
& SLAB_STORE_USER
) {
2758 set_store_user_dirty(cachep
);
2759 *dbg_userword(cachep
, objp
) = (void *)caller
;
2762 objnr
= obj_to_index(cachep
, page
, objp
);
2764 BUG_ON(objnr
>= cachep
->num
);
2765 BUG_ON(objp
!= index_to_obj(cachep
, page
, objnr
));
2767 if (cachep
->flags
& SLAB_POISON
) {
2768 poison_obj(cachep
, objp
, POISON_FREE
);
2769 slab_kernel_map(cachep
, objp
, 0, caller
);
2775 #define kfree_debugcheck(x) do { } while(0)
2776 #define cache_free_debugcheck(x,objp,z) (objp)
2779 static void *cache_alloc_refill(struct kmem_cache
*cachep
, gfp_t flags
,
2783 struct kmem_cache_node
*n
;
2784 struct array_cache
*ac
;
2788 node
= numa_mem_id();
2789 if (unlikely(force_refill
))
2792 ac
= cpu_cache_get(cachep
);
2793 batchcount
= ac
->batchcount
;
2794 if (!ac
->touched
&& batchcount
> BATCHREFILL_LIMIT
) {
2796 * If there was little recent activity on this cache, then
2797 * perform only a partial refill. Otherwise we could generate
2800 batchcount
= BATCHREFILL_LIMIT
;
2802 n
= get_node(cachep
, node
);
2804 BUG_ON(ac
->avail
> 0 || !n
);
2805 spin_lock(&n
->list_lock
);
2807 /* See if we can refill from the shared array */
2808 if (n
->shared
&& transfer_objects(ac
, n
->shared
, batchcount
)) {
2809 n
->shared
->touched
= 1;
2813 while (batchcount
> 0) {
2814 struct list_head
*entry
;
2816 /* Get slab alloc is to come from. */
2817 entry
= n
->slabs_partial
.next
;
2818 if (entry
== &n
->slabs_partial
) {
2819 n
->free_touched
= 1;
2820 entry
= n
->slabs_free
.next
;
2821 if (entry
== &n
->slabs_free
)
2825 page
= list_entry(entry
, struct page
, lru
);
2826 check_spinlock_acquired(cachep
);
2829 * The slab was either on partial or free list so
2830 * there must be at least one object available for
2833 BUG_ON(page
->active
>= cachep
->num
);
2835 while (page
->active
< cachep
->num
&& batchcount
--) {
2836 STATS_INC_ALLOCED(cachep
);
2837 STATS_INC_ACTIVE(cachep
);
2838 STATS_SET_HIGH(cachep
);
2840 ac_put_obj(cachep
, ac
, slab_get_obj(cachep
, page
,
2844 /* move slabp to correct slabp list: */
2845 list_del(&page
->lru
);
2846 if (page
->active
== cachep
->num
)
2847 list_add(&page
->lru
, &n
->slabs_full
);
2849 list_add(&page
->lru
, &n
->slabs_partial
);
2853 n
->free_objects
-= ac
->avail
;
2855 spin_unlock(&n
->list_lock
);
2857 if (unlikely(!ac
->avail
)) {
2860 x
= cache_grow(cachep
, gfp_exact_node(flags
), node
, NULL
);
2862 /* cache_grow can reenable interrupts, then ac could change. */
2863 ac
= cpu_cache_get(cachep
);
2864 node
= numa_mem_id();
2866 /* no objects in sight? abort */
2867 if (!x
&& (ac
->avail
== 0 || force_refill
))
2870 if (!ac
->avail
) /* objects refilled by interrupt? */
2875 return ac_get_obj(cachep
, ac
, flags
, force_refill
);
2878 static inline void cache_alloc_debugcheck_before(struct kmem_cache
*cachep
,
2881 might_sleep_if(gfpflags_allow_blocking(flags
));
2883 kmem_flagcheck(cachep
, flags
);
2888 static void *cache_alloc_debugcheck_after(struct kmem_cache
*cachep
,
2889 gfp_t flags
, void *objp
, unsigned long caller
)
2893 if (cachep
->flags
& SLAB_POISON
) {
2894 check_poison_obj(cachep
, objp
);
2895 slab_kernel_map(cachep
, objp
, 1, 0);
2896 poison_obj(cachep
, objp
, POISON_INUSE
);
2898 if (cachep
->flags
& SLAB_STORE_USER
)
2899 *dbg_userword(cachep
, objp
) = (void *)caller
;
2901 if (cachep
->flags
& SLAB_RED_ZONE
) {
2902 if (*dbg_redzone1(cachep
, objp
) != RED_INACTIVE
||
2903 *dbg_redzone2(cachep
, objp
) != RED_INACTIVE
) {
2904 slab_error(cachep
, "double free, or memory outside object was overwritten");
2906 "%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
2907 objp
, *dbg_redzone1(cachep
, objp
),
2908 *dbg_redzone2(cachep
, objp
));
2910 *dbg_redzone1(cachep
, objp
) = RED_ACTIVE
;
2911 *dbg_redzone2(cachep
, objp
) = RED_ACTIVE
;
2914 objp
+= obj_offset(cachep
);
2915 if (cachep
->ctor
&& cachep
->flags
& SLAB_POISON
)
2917 if (ARCH_SLAB_MINALIGN
&&
2918 ((unsigned long)objp
& (ARCH_SLAB_MINALIGN
-1))) {
2919 printk(KERN_ERR
"0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
2920 objp
, (int)ARCH_SLAB_MINALIGN
);
2925 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
2928 static bool slab_should_failslab(struct kmem_cache
*cachep
, gfp_t flags
)
2930 if (unlikely(cachep
== kmem_cache
))
2933 return should_failslab(cachep
->object_size
, flags
, cachep
->flags
);
2936 static inline void *____cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2939 struct array_cache
*ac
;
2940 bool force_refill
= false;
2944 ac
= cpu_cache_get(cachep
);
2945 if (likely(ac
->avail
)) {
2947 objp
= ac_get_obj(cachep
, ac
, flags
, false);
2950 * Allow for the possibility all avail objects are not allowed
2951 * by the current flags
2954 STATS_INC_ALLOCHIT(cachep
);
2957 force_refill
= true;
2960 STATS_INC_ALLOCMISS(cachep
);
2961 objp
= cache_alloc_refill(cachep
, flags
, force_refill
);
2963 * the 'ac' may be updated by cache_alloc_refill(),
2964 * and kmemleak_erase() requires its correct value.
2966 ac
= cpu_cache_get(cachep
);
2970 * To avoid a false negative, if an object that is in one of the
2971 * per-CPU caches is leaked, we need to make sure kmemleak doesn't
2972 * treat the array pointers as a reference to the object.
2975 kmemleak_erase(&ac
->entry
[ac
->avail
]);
2981 * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set.
2983 * If we are in_interrupt, then process context, including cpusets and
2984 * mempolicy, may not apply and should not be used for allocation policy.
2986 static void *alternate_node_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
2988 int nid_alloc
, nid_here
;
2990 if (in_interrupt() || (flags
& __GFP_THISNODE
))
2992 nid_alloc
= nid_here
= numa_mem_id();
2993 if (cpuset_do_slab_mem_spread() && (cachep
->flags
& SLAB_MEM_SPREAD
))
2994 nid_alloc
= cpuset_slab_spread_node();
2995 else if (current
->mempolicy
)
2996 nid_alloc
= mempolicy_slab_node();
2997 if (nid_alloc
!= nid_here
)
2998 return ____cache_alloc_node(cachep
, flags
, nid_alloc
);
3003 * Fallback function if there was no memory available and no objects on a
3004 * certain node and fall back is permitted. First we scan all the
3005 * available node for available objects. If that fails then we
3006 * perform an allocation without specifying a node. This allows the page
3007 * allocator to do its reclaim / fallback magic. We then insert the
3008 * slab into the proper nodelist and then allocate from it.
3010 static void *fallback_alloc(struct kmem_cache
*cache
, gfp_t flags
)
3012 struct zonelist
*zonelist
;
3016 enum zone_type high_zoneidx
= gfp_zone(flags
);
3019 unsigned int cpuset_mems_cookie
;
3021 if (flags
& __GFP_THISNODE
)
3024 local_flags
= flags
& (GFP_CONSTRAINT_MASK
|GFP_RECLAIM_MASK
);
3027 cpuset_mems_cookie
= read_mems_allowed_begin();
3028 zonelist
= node_zonelist(mempolicy_slab_node(), flags
);
3032 * Look through allowed nodes for objects available
3033 * from existing per node queues.
3035 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
3036 nid
= zone_to_nid(zone
);
3038 if (cpuset_zone_allowed(zone
, flags
) &&
3039 get_node(cache
, nid
) &&
3040 get_node(cache
, nid
)->free_objects
) {
3041 obj
= ____cache_alloc_node(cache
,
3042 gfp_exact_node(flags
), nid
);
3050 * This allocation will be performed within the constraints
3051 * of the current cpuset / memory policy requirements.
3052 * We may trigger various forms of reclaim on the allowed
3053 * set and go into memory reserves if necessary.
3057 if (gfpflags_allow_blocking(local_flags
))
3059 kmem_flagcheck(cache
, flags
);
3060 page
= kmem_getpages(cache
, local_flags
, numa_mem_id());
3061 if (gfpflags_allow_blocking(local_flags
))
3062 local_irq_disable();
3065 * Insert into the appropriate per node queues
3067 nid
= page_to_nid(page
);
3068 if (cache_grow(cache
, flags
, nid
, page
)) {
3069 obj
= ____cache_alloc_node(cache
,
3070 gfp_exact_node(flags
), nid
);
3073 * Another processor may allocate the
3074 * objects in the slab since we are
3075 * not holding any locks.
3079 /* cache_grow already freed obj */
3085 if (unlikely(!obj
&& read_mems_allowed_retry(cpuset_mems_cookie
)))
3091 * A interface to enable slab creation on nodeid
3093 static void *____cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
,
3096 struct list_head
*entry
;
3098 struct kmem_cache_node
*n
;
3102 VM_BUG_ON(nodeid
< 0 || nodeid
>= MAX_NUMNODES
);
3103 n
= get_node(cachep
, nodeid
);
3108 spin_lock(&n
->list_lock
);
3109 entry
= n
->slabs_partial
.next
;
3110 if (entry
== &n
->slabs_partial
) {
3111 n
->free_touched
= 1;
3112 entry
= n
->slabs_free
.next
;
3113 if (entry
== &n
->slabs_free
)
3117 page
= list_entry(entry
, struct page
, lru
);
3118 check_spinlock_acquired_node(cachep
, nodeid
);
3120 STATS_INC_NODEALLOCS(cachep
);
3121 STATS_INC_ACTIVE(cachep
);
3122 STATS_SET_HIGH(cachep
);
3124 BUG_ON(page
->active
== cachep
->num
);
3126 obj
= slab_get_obj(cachep
, page
, nodeid
);
3128 /* move slabp to correct slabp list: */
3129 list_del(&page
->lru
);
3131 if (page
->active
== cachep
->num
)
3132 list_add(&page
->lru
, &n
->slabs_full
);
3134 list_add(&page
->lru
, &n
->slabs_partial
);
3136 spin_unlock(&n
->list_lock
);
3140 spin_unlock(&n
->list_lock
);
3141 x
= cache_grow(cachep
, gfp_exact_node(flags
), nodeid
, NULL
);
3145 return fallback_alloc(cachep
, flags
);
3151 static __always_inline
void *
3152 slab_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
,
3153 unsigned long caller
)
3155 unsigned long save_flags
;
3157 int slab_node
= numa_mem_id();
3159 flags
&= gfp_allowed_mask
;
3161 lockdep_trace_alloc(flags
);
3163 if (slab_should_failslab(cachep
, flags
))
3166 cachep
= memcg_kmem_get_cache(cachep
, flags
);
3168 cache_alloc_debugcheck_before(cachep
, flags
);
3169 local_irq_save(save_flags
);
3171 if (nodeid
== NUMA_NO_NODE
)
3174 if (unlikely(!get_node(cachep
, nodeid
))) {
3175 /* Node not bootstrapped yet */
3176 ptr
= fallback_alloc(cachep
, flags
);
3180 if (nodeid
== slab_node
) {
3182 * Use the locally cached objects if possible.
3183 * However ____cache_alloc does not allow fallback
3184 * to other nodes. It may fail while we still have
3185 * objects on other nodes available.
3187 ptr
= ____cache_alloc(cachep
, flags
);
3191 /* ___cache_alloc_node can fall back to other nodes */
3192 ptr
= ____cache_alloc_node(cachep
, flags
, nodeid
);
3194 local_irq_restore(save_flags
);
3195 ptr
= cache_alloc_debugcheck_after(cachep
, flags
, ptr
, caller
);
3196 kmemleak_alloc_recursive(ptr
, cachep
->object_size
, 1, cachep
->flags
,
3200 kmemcheck_slab_alloc(cachep
, flags
, ptr
, cachep
->object_size
);
3201 if (unlikely(flags
& __GFP_ZERO
))
3202 memset(ptr
, 0, cachep
->object_size
);
3205 memcg_kmem_put_cache(cachep
);
3209 static __always_inline
void *
3210 __do_cache_alloc(struct kmem_cache
*cache
, gfp_t flags
)
3214 if (current
->mempolicy
|| cpuset_do_slab_mem_spread()) {
3215 objp
= alternate_node_alloc(cache
, flags
);
3219 objp
= ____cache_alloc(cache
, flags
);
3222 * We may just have run out of memory on the local node.
3223 * ____cache_alloc_node() knows how to locate memory on other nodes
3226 objp
= ____cache_alloc_node(cache
, flags
, numa_mem_id());
3233 static __always_inline
void *
3234 __do_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3236 return ____cache_alloc(cachep
, flags
);
3239 #endif /* CONFIG_NUMA */
3241 static __always_inline
void *
3242 slab_alloc(struct kmem_cache
*cachep
, gfp_t flags
, unsigned long caller
)
3244 unsigned long save_flags
;
3247 flags
&= gfp_allowed_mask
;
3249 lockdep_trace_alloc(flags
);
3251 if (slab_should_failslab(cachep
, flags
))
3254 cachep
= memcg_kmem_get_cache(cachep
, flags
);
3256 cache_alloc_debugcheck_before(cachep
, flags
);
3257 local_irq_save(save_flags
);
3258 objp
= __do_cache_alloc(cachep
, flags
);
3259 local_irq_restore(save_flags
);
3260 objp
= cache_alloc_debugcheck_after(cachep
, flags
, objp
, caller
);
3261 kmemleak_alloc_recursive(objp
, cachep
->object_size
, 1, cachep
->flags
,
3266 kmemcheck_slab_alloc(cachep
, flags
, objp
, cachep
->object_size
);
3267 if (unlikely(flags
& __GFP_ZERO
))
3268 memset(objp
, 0, cachep
->object_size
);
3271 memcg_kmem_put_cache(cachep
);
3276 * Caller needs to acquire correct kmem_cache_node's list_lock
3277 * @list: List of detached free slabs should be freed by caller
3279 static void free_block(struct kmem_cache
*cachep
, void **objpp
,
3280 int nr_objects
, int node
, struct list_head
*list
)
3283 struct kmem_cache_node
*n
= get_node(cachep
, node
);
3285 for (i
= 0; i
< nr_objects
; i
++) {
3289 clear_obj_pfmemalloc(&objpp
[i
]);
3292 page
= virt_to_head_page(objp
);
3293 list_del(&page
->lru
);
3294 check_spinlock_acquired_node(cachep
, node
);
3295 slab_put_obj(cachep
, page
, objp
, node
);
3296 STATS_DEC_ACTIVE(cachep
);
3299 /* fixup slab chains */
3300 if (page
->active
== 0) {
3301 if (n
->free_objects
> n
->free_limit
) {
3302 n
->free_objects
-= cachep
->num
;
3303 list_add_tail(&page
->lru
, list
);
3305 list_add(&page
->lru
, &n
->slabs_free
);
3308 /* Unconditionally move a slab to the end of the
3309 * partial list on free - maximum time for the
3310 * other objects to be freed, too.
3312 list_add_tail(&page
->lru
, &n
->slabs_partial
);
3317 static void cache_flusharray(struct kmem_cache
*cachep
, struct array_cache
*ac
)
3320 struct kmem_cache_node
*n
;
3321 int node
= numa_mem_id();
3324 batchcount
= ac
->batchcount
;
3326 BUG_ON(!batchcount
|| batchcount
> ac
->avail
);
3329 n
= get_node(cachep
, node
);
3330 spin_lock(&n
->list_lock
);
3332 struct array_cache
*shared_array
= n
->shared
;
3333 int max
= shared_array
->limit
- shared_array
->avail
;
3335 if (batchcount
> max
)
3337 memcpy(&(shared_array
->entry
[shared_array
->avail
]),
3338 ac
->entry
, sizeof(void *) * batchcount
);
3339 shared_array
->avail
+= batchcount
;
3344 free_block(cachep
, ac
->entry
, batchcount
, node
, &list
);
3349 struct list_head
*p
;
3351 p
= n
->slabs_free
.next
;
3352 while (p
!= &(n
->slabs_free
)) {
3355 page
= list_entry(p
, struct page
, lru
);
3356 BUG_ON(page
->active
);
3361 STATS_SET_FREEABLE(cachep
, i
);
3364 spin_unlock(&n
->list_lock
);
3365 slabs_destroy(cachep
, &list
);
3366 ac
->avail
-= batchcount
;
3367 memmove(ac
->entry
, &(ac
->entry
[batchcount
]), sizeof(void *)*ac
->avail
);
3371 * Release an obj back to its cache. If the obj has a constructed state, it must
3372 * be in this state _before_ it is released. Called with disabled ints.
3374 static inline void __cache_free(struct kmem_cache
*cachep
, void *objp
,
3375 unsigned long caller
)
3377 /* Put the object into the quarantine, don't touch it for now. */
3378 if (kasan_slab_free(cachep
, objp
))
3381 ___cache_free(cachep
, objp
, caller
);
3384 void ___cache_free(struct kmem_cache
*cachep
, void *objp
,
3385 unsigned long caller
)
3387 struct array_cache
*ac
= cpu_cache_get(cachep
);
3390 kmemleak_free_recursive(objp
, cachep
->flags
);
3391 objp
= cache_free_debugcheck(cachep
, objp
, caller
);
3393 kmemcheck_slab_free(cachep
, objp
, cachep
->object_size
);
3396 * Skip calling cache_free_alien() when the platform is not numa.
3397 * This will avoid cache misses that happen while accessing slabp (which
3398 * is per page memory reference) to get nodeid. Instead use a global
3399 * variable to skip the call, which is mostly likely to be present in
3402 if (nr_online_nodes
> 1 && cache_free_alien(cachep
, objp
))
3405 if (ac
->avail
< ac
->limit
) {
3406 STATS_INC_FREEHIT(cachep
);
3408 STATS_INC_FREEMISS(cachep
);
3409 cache_flusharray(cachep
, ac
);
3412 ac_put_obj(cachep
, ac
, objp
);
3416 * kmem_cache_alloc - Allocate an object
3417 * @cachep: The cache to allocate from.
3418 * @flags: See kmalloc().
3420 * Allocate an object from this cache. The flags are only relevant
3421 * if the cache has no available objects.
3423 void *kmem_cache_alloc(struct kmem_cache
*cachep
, gfp_t flags
)
3425 void *ret
= slab_alloc(cachep
, flags
, _RET_IP_
);
3427 kasan_slab_alloc(cachep
, ret
, flags
);
3428 trace_kmem_cache_alloc(_RET_IP_
, ret
,
3429 cachep
->object_size
, cachep
->size
, flags
);
3433 EXPORT_SYMBOL(kmem_cache_alloc
);
3435 void kmem_cache_free_bulk(struct kmem_cache
*s
, size_t size
, void **p
)
3437 __kmem_cache_free_bulk(s
, size
, p
);
3439 EXPORT_SYMBOL(kmem_cache_free_bulk
);
3441 int kmem_cache_alloc_bulk(struct kmem_cache
*s
, gfp_t flags
, size_t size
,
3444 return __kmem_cache_alloc_bulk(s
, flags
, size
, p
);
3446 EXPORT_SYMBOL(kmem_cache_alloc_bulk
);
3448 #ifdef CONFIG_TRACING
3450 kmem_cache_alloc_trace(struct kmem_cache
*cachep
, gfp_t flags
, size_t size
)
3454 ret
= slab_alloc(cachep
, flags
, _RET_IP_
);
3456 kasan_kmalloc(cachep
, ret
, size
, flags
);
3457 trace_kmalloc(_RET_IP_
, ret
,
3458 size
, cachep
->size
, flags
);
3461 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
3466 * kmem_cache_alloc_node - Allocate an object on the specified node
3467 * @cachep: The cache to allocate from.
3468 * @flags: See kmalloc().
3469 * @nodeid: node number of the target node.
3471 * Identical to kmem_cache_alloc but it will allocate memory on the given
3472 * node, which can improve the performance for cpu bound structures.
3474 * Fallback to other node is possible if __GFP_THISNODE is not set.
3476 void *kmem_cache_alloc_node(struct kmem_cache
*cachep
, gfp_t flags
, int nodeid
)
3478 void *ret
= slab_alloc_node(cachep
, flags
, nodeid
, _RET_IP_
);
3480 kasan_slab_alloc(cachep
, ret
, flags
);
3481 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
3482 cachep
->object_size
, cachep
->size
,
3487 EXPORT_SYMBOL(kmem_cache_alloc_node
);
3489 #ifdef CONFIG_TRACING
3490 void *kmem_cache_alloc_node_trace(struct kmem_cache
*cachep
,
3497 ret
= slab_alloc_node(cachep
, flags
, nodeid
, _RET_IP_
);
3499 kasan_kmalloc(cachep
, ret
, size
, flags
);
3500 trace_kmalloc_node(_RET_IP_
, ret
,
3505 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
3508 static __always_inline
void *
3509 __do_kmalloc_node(size_t size
, gfp_t flags
, int node
, unsigned long caller
)
3511 struct kmem_cache
*cachep
;
3514 cachep
= kmalloc_slab(size
, flags
);
3515 if (unlikely(ZERO_OR_NULL_PTR(cachep
)))
3517 ret
= kmem_cache_alloc_node_trace(cachep
, flags
, node
, size
);
3518 kasan_kmalloc(cachep
, ret
, size
, flags
);
3523 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3525 return __do_kmalloc_node(size
, flags
, node
, _RET_IP_
);
3527 EXPORT_SYMBOL(__kmalloc_node
);
3529 void *__kmalloc_node_track_caller(size_t size
, gfp_t flags
,
3530 int node
, unsigned long caller
)
3532 return __do_kmalloc_node(size
, flags
, node
, caller
);
3534 EXPORT_SYMBOL(__kmalloc_node_track_caller
);
3535 #endif /* CONFIG_NUMA */
3538 * __do_kmalloc - allocate memory
3539 * @size: how many bytes of memory are required.
3540 * @flags: the type of memory to allocate (see kmalloc).
3541 * @caller: function caller for debug tracking of the caller
3543 static __always_inline
void *__do_kmalloc(size_t size
, gfp_t flags
,
3544 unsigned long caller
)
3546 struct kmem_cache
*cachep
;
3549 cachep
= kmalloc_slab(size
, flags
);
3550 if (unlikely(ZERO_OR_NULL_PTR(cachep
)))
3552 ret
= slab_alloc(cachep
, flags
, caller
);
3554 kasan_kmalloc(cachep
, ret
, size
, flags
);
3555 trace_kmalloc(caller
, ret
,
3556 size
, cachep
->size
, flags
);
3561 void *__kmalloc(size_t size
, gfp_t flags
)
3563 return __do_kmalloc(size
, flags
, _RET_IP_
);
3565 EXPORT_SYMBOL(__kmalloc
);
3567 void *__kmalloc_track_caller(size_t size
, gfp_t flags
, unsigned long caller
)
3569 return __do_kmalloc(size
, flags
, caller
);
3571 EXPORT_SYMBOL(__kmalloc_track_caller
);
3574 * kmem_cache_free - Deallocate an object
3575 * @cachep: The cache the allocation was from.
3576 * @objp: The previously allocated object.
3578 * Free an object which was previously allocated from this
3581 void kmem_cache_free(struct kmem_cache
*cachep
, void *objp
)
3583 unsigned long flags
;
3584 cachep
= cache_from_obj(cachep
, objp
);
3588 local_irq_save(flags
);
3589 debug_check_no_locks_freed(objp
, cachep
->object_size
);
3590 if (!(cachep
->flags
& SLAB_DEBUG_OBJECTS
))
3591 debug_check_no_obj_freed(objp
, cachep
->object_size
);
3592 __cache_free(cachep
, objp
, _RET_IP_
);
3593 local_irq_restore(flags
);
3595 trace_kmem_cache_free(_RET_IP_
, objp
);
3597 EXPORT_SYMBOL(kmem_cache_free
);
3600 * kfree - free previously allocated memory
3601 * @objp: pointer returned by kmalloc.
3603 * If @objp is NULL, no operation is performed.
3605 * Don't free memory not originally allocated by kmalloc()
3606 * or you will run into trouble.
3608 void kfree(const void *objp
)
3610 struct kmem_cache
*c
;
3611 unsigned long flags
;
3613 trace_kfree(_RET_IP_
, objp
);
3615 if (unlikely(ZERO_OR_NULL_PTR(objp
)))
3617 local_irq_save(flags
);
3618 kfree_debugcheck(objp
);
3619 c
= virt_to_cache(objp
);
3620 debug_check_no_locks_freed(objp
, c
->object_size
);
3622 debug_check_no_obj_freed(objp
, c
->object_size
);
3623 __cache_free(c
, (void *)objp
, _RET_IP_
);
3624 local_irq_restore(flags
);
3626 EXPORT_SYMBOL(kfree
);
3629 * This initializes kmem_cache_node or resizes various caches for all nodes.
3631 static int alloc_kmem_cache_node(struct kmem_cache
*cachep
, gfp_t gfp
)
3634 struct kmem_cache_node
*n
;
3635 struct array_cache
*new_shared
;
3636 struct alien_cache
**new_alien
= NULL
;
3638 for_each_online_node(node
) {
3640 if (use_alien_caches
) {
3641 new_alien
= alloc_alien_cache(node
, cachep
->limit
, gfp
);
3647 if (cachep
->shared
) {
3648 new_shared
= alloc_arraycache(node
,
3649 cachep
->shared
*cachep
->batchcount
,
3652 free_alien_cache(new_alien
);
3657 n
= get_node(cachep
, node
);
3659 struct array_cache
*shared
= n
->shared
;
3662 spin_lock_irq(&n
->list_lock
);
3665 free_block(cachep
, shared
->entry
,
3666 shared
->avail
, node
, &list
);
3668 n
->shared
= new_shared
;
3670 n
->alien
= new_alien
;
3673 n
->free_limit
= (1 + nr_cpus_node(node
)) *
3674 cachep
->batchcount
+ cachep
->num
;
3675 spin_unlock_irq(&n
->list_lock
);
3676 slabs_destroy(cachep
, &list
);
3678 free_alien_cache(new_alien
);
3681 n
= kmalloc_node(sizeof(struct kmem_cache_node
), gfp
, node
);
3683 free_alien_cache(new_alien
);
3688 kmem_cache_node_init(n
);
3689 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
+
3690 ((unsigned long)cachep
) % REAPTIMEOUT_NODE
;
3691 n
->shared
= new_shared
;
3692 n
->alien
= new_alien
;
3693 n
->free_limit
= (1 + nr_cpus_node(node
)) *
3694 cachep
->batchcount
+ cachep
->num
;
3695 cachep
->node
[node
] = n
;
3700 if (!cachep
->list
.next
) {
3701 /* Cache is not active yet. Roll back what we did */
3704 n
= get_node(cachep
, node
);
3707 free_alien_cache(n
->alien
);
3709 cachep
->node
[node
] = NULL
;
3717 /* Always called with the slab_mutex held */
3718 static int __do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3719 int batchcount
, int shared
, gfp_t gfp
)
3721 struct array_cache __percpu
*cpu_cache
, *prev
;
3724 cpu_cache
= alloc_kmem_cache_cpus(cachep
, limit
, batchcount
);
3728 prev
= cachep
->cpu_cache
;
3729 cachep
->cpu_cache
= cpu_cache
;
3730 kick_all_cpus_sync();
3733 cachep
->batchcount
= batchcount
;
3734 cachep
->limit
= limit
;
3735 cachep
->shared
= shared
;
3740 for_each_online_cpu(cpu
) {
3743 struct kmem_cache_node
*n
;
3744 struct array_cache
*ac
= per_cpu_ptr(prev
, cpu
);
3746 node
= cpu_to_mem(cpu
);
3747 n
= get_node(cachep
, node
);
3748 spin_lock_irq(&n
->list_lock
);
3749 free_block(cachep
, ac
->entry
, ac
->avail
, node
, &list
);
3750 spin_unlock_irq(&n
->list_lock
);
3751 slabs_destroy(cachep
, &list
);
3756 return alloc_kmem_cache_node(cachep
, gfp
);
3759 static int do_tune_cpucache(struct kmem_cache
*cachep
, int limit
,
3760 int batchcount
, int shared
, gfp_t gfp
)
3763 struct kmem_cache
*c
;
3765 ret
= __do_tune_cpucache(cachep
, limit
, batchcount
, shared
, gfp
);
3767 if (slab_state
< FULL
)
3770 if ((ret
< 0) || !is_root_cache(cachep
))
3773 lockdep_assert_held(&slab_mutex
);
3774 for_each_memcg_cache(c
, cachep
) {
3775 /* return value determined by the root cache only */
3776 __do_tune_cpucache(c
, limit
, batchcount
, shared
, gfp
);
3782 /* Called with slab_mutex held always */
3783 static int enable_cpucache(struct kmem_cache
*cachep
, gfp_t gfp
)
3790 if (!is_root_cache(cachep
)) {
3791 struct kmem_cache
*root
= memcg_root_cache(cachep
);
3792 limit
= root
->limit
;
3793 shared
= root
->shared
;
3794 batchcount
= root
->batchcount
;
3797 if (limit
&& shared
&& batchcount
)
3800 * The head array serves three purposes:
3801 * - create a LIFO ordering, i.e. return objects that are cache-warm
3802 * - reduce the number of spinlock operations.
3803 * - reduce the number of linked list operations on the slab and
3804 * bufctl chains: array operations are cheaper.
3805 * The numbers are guessed, we should auto-tune as described by
3808 if (cachep
->size
> 131072)
3810 else if (cachep
->size
> PAGE_SIZE
)
3812 else if (cachep
->size
> 1024)
3814 else if (cachep
->size
> 256)
3820 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3821 * allocation behaviour: Most allocs on one cpu, most free operations
3822 * on another cpu. For these cases, an efficient object passing between
3823 * cpus is necessary. This is provided by a shared array. The array
3824 * replaces Bonwick's magazine layer.
3825 * On uniprocessor, it's functionally equivalent (but less efficient)
3826 * to a larger limit. Thus disabled by default.
3829 if (cachep
->size
<= PAGE_SIZE
&& num_possible_cpus() > 1)
3834 * With debugging enabled, large batchcount lead to excessively long
3835 * periods with disabled local interrupts. Limit the batchcount
3840 batchcount
= (limit
+ 1) / 2;
3842 err
= do_tune_cpucache(cachep
, limit
, batchcount
, shared
, gfp
);
3844 printk(KERN_ERR
"enable_cpucache failed for %s, error %d.\n",
3845 cachep
->name
, -err
);
3850 * Drain an array if it contains any elements taking the node lock only if
3851 * necessary. Note that the node listlock also protects the array_cache
3852 * if drain_array() is used on the shared array.
3854 static void drain_array(struct kmem_cache
*cachep
, struct kmem_cache_node
*n
,
3855 struct array_cache
*ac
, int force
, int node
)
3860 if (!ac
|| !ac
->avail
)
3862 if (ac
->touched
&& !force
) {
3865 spin_lock_irq(&n
->list_lock
);
3867 tofree
= force
? ac
->avail
: (ac
->limit
+ 4) / 5;
3868 if (tofree
> ac
->avail
)
3869 tofree
= (ac
->avail
+ 1) / 2;
3870 free_block(cachep
, ac
->entry
, tofree
, node
, &list
);
3871 ac
->avail
-= tofree
;
3872 memmove(ac
->entry
, &(ac
->entry
[tofree
]),
3873 sizeof(void *) * ac
->avail
);
3875 spin_unlock_irq(&n
->list_lock
);
3876 slabs_destroy(cachep
, &list
);
3881 * cache_reap - Reclaim memory from caches.
3882 * @w: work descriptor
3884 * Called from workqueue/eventd every few seconds.
3886 * - clear the per-cpu caches for this CPU.
3887 * - return freeable pages to the main free memory pool.
3889 * If we cannot acquire the cache chain mutex then just give up - we'll try
3890 * again on the next iteration.
3892 static void cache_reap(struct work_struct
*w
)
3894 struct kmem_cache
*searchp
;
3895 struct kmem_cache_node
*n
;
3896 int node
= numa_mem_id();
3897 struct delayed_work
*work
= to_delayed_work(w
);
3899 if (!mutex_trylock(&slab_mutex
))
3900 /* Give up. Setup the next iteration. */
3903 list_for_each_entry(searchp
, &slab_caches
, list
) {
3907 * We only take the node lock if absolutely necessary and we
3908 * have established with reasonable certainty that
3909 * we can do some work if the lock was obtained.
3911 n
= get_node(searchp
, node
);
3913 reap_alien(searchp
, n
);
3915 drain_array(searchp
, n
, cpu_cache_get(searchp
), 0, node
);
3918 * These are racy checks but it does not matter
3919 * if we skip one check or scan twice.
3921 if (time_after(n
->next_reap
, jiffies
))
3924 n
->next_reap
= jiffies
+ REAPTIMEOUT_NODE
;
3926 drain_array(searchp
, n
, n
->shared
, 0, node
);
3928 if (n
->free_touched
)
3929 n
->free_touched
= 0;
3933 freed
= drain_freelist(searchp
, n
, (n
->free_limit
+
3934 5 * searchp
->num
- 1) / (5 * searchp
->num
));
3935 STATS_ADD_REAPED(searchp
, freed
);
3941 mutex_unlock(&slab_mutex
);
3944 /* Set up the next iteration */
3945 schedule_delayed_work(work
, round_jiffies_relative(REAPTIMEOUT_AC
));
3948 #ifdef CONFIG_SLABINFO
3949 void get_slabinfo(struct kmem_cache
*cachep
, struct slabinfo
*sinfo
)
3952 unsigned long active_objs
;
3953 unsigned long num_objs
;
3954 unsigned long active_slabs
= 0;
3955 unsigned long num_slabs
, free_objects
= 0, shared_avail
= 0;
3959 struct kmem_cache_node
*n
;
3963 for_each_kmem_cache_node(cachep
, node
, n
) {
3966 spin_lock_irq(&n
->list_lock
);
3968 list_for_each_entry(page
, &n
->slabs_full
, lru
) {
3969 if (page
->active
!= cachep
->num
&& !error
)
3970 error
= "slabs_full accounting error";
3971 active_objs
+= cachep
->num
;
3974 list_for_each_entry(page
, &n
->slabs_partial
, lru
) {
3975 if (page
->active
== cachep
->num
&& !error
)
3976 error
= "slabs_partial accounting error";
3977 if (!page
->active
&& !error
)
3978 error
= "slabs_partial accounting error";
3979 active_objs
+= page
->active
;
3982 list_for_each_entry(page
, &n
->slabs_free
, lru
) {
3983 if (page
->active
&& !error
)
3984 error
= "slabs_free accounting error";
3987 free_objects
+= n
->free_objects
;
3989 shared_avail
+= n
->shared
->avail
;
3991 spin_unlock_irq(&n
->list_lock
);
3993 num_slabs
+= active_slabs
;
3994 num_objs
= num_slabs
* cachep
->num
;
3995 if (num_objs
- active_objs
!= free_objects
&& !error
)
3996 error
= "free_objects accounting error";
3998 name
= cachep
->name
;
4000 printk(KERN_ERR
"slab: cache %s error: %s\n", name
, error
);
4002 sinfo
->active_objs
= active_objs
;
4003 sinfo
->num_objs
= num_objs
;
4004 sinfo
->active_slabs
= active_slabs
;
4005 sinfo
->num_slabs
= num_slabs
;
4006 sinfo
->shared_avail
= shared_avail
;
4007 sinfo
->limit
= cachep
->limit
;
4008 sinfo
->batchcount
= cachep
->batchcount
;
4009 sinfo
->shared
= cachep
->shared
;
4010 sinfo
->objects_per_slab
= cachep
->num
;
4011 sinfo
->cache_order
= cachep
->gfporder
;
4014 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*cachep
)
4018 unsigned long high
= cachep
->high_mark
;
4019 unsigned long allocs
= cachep
->num_allocations
;
4020 unsigned long grown
= cachep
->grown
;
4021 unsigned long reaped
= cachep
->reaped
;
4022 unsigned long errors
= cachep
->errors
;
4023 unsigned long max_freeable
= cachep
->max_freeable
;
4024 unsigned long node_allocs
= cachep
->node_allocs
;
4025 unsigned long node_frees
= cachep
->node_frees
;
4026 unsigned long overflows
= cachep
->node_overflow
;
4028 seq_printf(m
, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu",
4029 allocs
, high
, grown
,
4030 reaped
, errors
, max_freeable
, node_allocs
,
4031 node_frees
, overflows
);
4035 unsigned long allochit
= atomic_read(&cachep
->allochit
);
4036 unsigned long allocmiss
= atomic_read(&cachep
->allocmiss
);
4037 unsigned long freehit
= atomic_read(&cachep
->freehit
);
4038 unsigned long freemiss
= atomic_read(&cachep
->freemiss
);
4040 seq_printf(m
, " : cpustat %6lu %6lu %6lu %6lu",
4041 allochit
, allocmiss
, freehit
, freemiss
);
4046 #define MAX_SLABINFO_WRITE 128
4048 * slabinfo_write - Tuning for the slab allocator
4050 * @buffer: user buffer
4051 * @count: data length
4054 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
4055 size_t count
, loff_t
*ppos
)
4057 char kbuf
[MAX_SLABINFO_WRITE
+ 1], *tmp
;
4058 int limit
, batchcount
, shared
, res
;
4059 struct kmem_cache
*cachep
;
4061 if (count
> MAX_SLABINFO_WRITE
)
4063 if (copy_from_user(&kbuf
, buffer
, count
))
4065 kbuf
[MAX_SLABINFO_WRITE
] = '\0';
4067 tmp
= strchr(kbuf
, ' ');
4072 if (sscanf(tmp
, " %d %d %d", &limit
, &batchcount
, &shared
) != 3)
4075 /* Find the cache in the chain of caches. */
4076 mutex_lock(&slab_mutex
);
4078 list_for_each_entry(cachep
, &slab_caches
, list
) {
4079 if (!strcmp(cachep
->name
, kbuf
)) {
4080 if (limit
< 1 || batchcount
< 1 ||
4081 batchcount
> limit
|| shared
< 0) {
4084 res
= do_tune_cpucache(cachep
, limit
,
4091 mutex_unlock(&slab_mutex
);
4097 #ifdef CONFIG_DEBUG_SLAB_LEAK
4099 static inline int add_caller(unsigned long *n
, unsigned long v
)
4109 unsigned long *q
= p
+ 2 * i
;
4123 memmove(p
+ 2, p
, n
[1] * 2 * sizeof(unsigned long) - ((void *)p
- (void *)n
));
4129 static void handle_slab(unsigned long *n
, struct kmem_cache
*c
,
4138 for (i
= 0, p
= page
->s_mem
; i
< c
->num
; i
++, p
+= c
->size
) {
4141 for (j
= page
->active
; j
< c
->num
; j
++) {
4142 if (get_free_obj(page
, j
) == i
) {
4152 * probe_kernel_read() is used for DEBUG_PAGEALLOC. page table
4153 * mapping is established when actual object allocation and
4154 * we could mistakenly access the unmapped object in the cpu
4157 if (probe_kernel_read(&v
, dbg_userword(c
, p
), sizeof(v
)))
4160 if (!add_caller(n
, v
))
4165 static void show_symbol(struct seq_file
*m
, unsigned long address
)
4167 #ifdef CONFIG_KALLSYMS
4168 unsigned long offset
, size
;
4169 char modname
[MODULE_NAME_LEN
], name
[KSYM_NAME_LEN
];
4171 if (lookup_symbol_attrs(address
, &size
, &offset
, modname
, name
) == 0) {
4172 seq_printf(m
, "%s+%#lx/%#lx", name
, offset
, size
);
4174 seq_printf(m
, " [%s]", modname
);
4178 seq_printf(m
, "%p", (void *)address
);
4181 static int leaks_show(struct seq_file
*m
, void *p
)
4183 struct kmem_cache
*cachep
= list_entry(p
, struct kmem_cache
, list
);
4185 struct kmem_cache_node
*n
;
4187 unsigned long *x
= m
->private;
4191 if (!(cachep
->flags
& SLAB_STORE_USER
))
4193 if (!(cachep
->flags
& SLAB_RED_ZONE
))
4197 * Set store_user_clean and start to grab stored user information
4198 * for all objects on this cache. If some alloc/free requests comes
4199 * during the processing, information would be wrong so restart
4203 set_store_user_clean(cachep
);
4204 drain_cpu_caches(cachep
);
4208 for_each_kmem_cache_node(cachep
, node
, n
) {
4211 spin_lock_irq(&n
->list_lock
);
4213 list_for_each_entry(page
, &n
->slabs_full
, lru
)
4214 handle_slab(x
, cachep
, page
);
4215 list_for_each_entry(page
, &n
->slabs_partial
, lru
)
4216 handle_slab(x
, cachep
, page
);
4217 spin_unlock_irq(&n
->list_lock
);
4219 } while (!is_store_user_clean(cachep
));
4221 name
= cachep
->name
;
4223 /* Increase the buffer size */
4224 mutex_unlock(&slab_mutex
);
4225 m
->private = kzalloc(x
[0] * 4 * sizeof(unsigned long), GFP_KERNEL
);
4227 /* Too bad, we are really out */
4229 mutex_lock(&slab_mutex
);
4232 *(unsigned long *)m
->private = x
[0] * 2;
4234 mutex_lock(&slab_mutex
);
4235 /* Now make sure this entry will be retried */
4239 for (i
= 0; i
< x
[1]; i
++) {
4240 seq_printf(m
, "%s: %lu ", name
, x
[2*i
+3]);
4241 show_symbol(m
, x
[2*i
+2]);
4248 static const struct seq_operations slabstats_op
= {
4249 .start
= slab_start
,
4255 static int slabstats_open(struct inode
*inode
, struct file
*file
)
4259 n
= __seq_open_private(file
, &slabstats_op
, PAGE_SIZE
);
4263 *n
= PAGE_SIZE
/ (2 * sizeof(unsigned long));
4268 static const struct file_operations proc_slabstats_operations
= {
4269 .open
= slabstats_open
,
4271 .llseek
= seq_lseek
,
4272 .release
= seq_release_private
,
4276 static int __init
slab_proc_init(void)
4278 #ifdef CONFIG_DEBUG_SLAB_LEAK
4279 proc_create("slab_allocators", 0, NULL
, &proc_slabstats_operations
);
4283 module_init(slab_proc_init
);
4286 #ifdef CONFIG_HARDENED_USERCOPY
4288 * Rejects objects that are incorrectly sized.
4290 * Returns NULL if check passes, otherwise const char * to name of cache
4291 * to indicate an error.
4293 const char *__check_heap_object(const void *ptr
, unsigned long n
,
4296 struct kmem_cache
*cachep
;
4298 unsigned long offset
;
4300 /* Find and validate object. */
4301 cachep
= page
->slab_cache
;
4302 objnr
= obj_to_index(cachep
, page
, (void *)ptr
);
4303 BUG_ON(objnr
>= cachep
->num
);
4305 /* Find offset within object. */
4306 offset
= ptr
- index_to_obj(cachep
, page
, objnr
) - obj_offset(cachep
);
4308 /* Allow address range falling entirely within object size. */
4309 if (offset
<= cachep
->object_size
&& n
<= cachep
->object_size
- offset
)
4312 return cachep
->name
;
4314 #endif /* CONFIG_HARDENED_USERCOPY */
4317 * ksize - get the actual amount of memory allocated for a given object
4318 * @objp: Pointer to the object
4320 * kmalloc may internally round up allocations and return more memory
4321 * than requested. ksize() can be used to determine the actual amount of
4322 * memory allocated. The caller may use this additional memory, even though
4323 * a smaller amount of memory was initially specified with the kmalloc call.
4324 * The caller must guarantee that objp points to a valid object previously
4325 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4326 * must not be freed during the duration of the call.
4328 size_t ksize(const void *objp
)
4333 if (unlikely(objp
== ZERO_SIZE_PTR
))
4336 size
= virt_to_cache(objp
)->object_size
;
4337 /* We assume that ksize callers could use the whole allocated area,
4338 * so we need to unpoison this area.
4340 kasan_krealloc(objp
, size
, GFP_NOWAIT
);
4344 EXPORT_SYMBOL(ksize
);