2 * SLUB: A slab allocator that limits cache line use instead of queuing
3 * objects in per cpu and per node lists.
5 * The allocator synchronizes using per slab locks or atomic operatios
6 * and only uses a centralized lock to manage a pool of partial slabs.
8 * (C) 2007 SGI, Christoph Lameter
9 * (C) 2011 Linux Foundation, Christoph Lameter
13 #include <linux/swap.h> /* struct reclaim_state */
14 #include <linux/module.h>
15 #include <linux/bit_spinlock.h>
16 #include <linux/interrupt.h>
17 #include <linux/bitops.h>
18 #include <linux/slab.h>
20 #include <linux/proc_fs.h>
21 #include <linux/seq_file.h>
22 #include <linux/kmemcheck.h>
23 #include <linux/cpu.h>
24 #include <linux/cpuset.h>
25 #include <linux/mempolicy.h>
26 #include <linux/ctype.h>
27 #include <linux/debugobjects.h>
28 #include <linux/kallsyms.h>
29 #include <linux/memory.h>
30 #include <linux/math64.h>
31 #include <linux/fault-inject.h>
32 #include <linux/stacktrace.h>
33 #include <linux/prefetch.h>
34 #include <linux/memcontrol.h>
36 #include <trace/events/kmem.h>
42 * 1. slab_mutex (Global Mutex)
44 * 3. slab_lock(page) (Only on some arches and for debugging)
48 * The role of the slab_mutex is to protect the list of all the slabs
49 * and to synchronize major metadata changes to slab cache structures.
51 * The slab_lock is only used for debugging and on arches that do not
52 * have the ability to do a cmpxchg_double. It only protects the second
53 * double word in the page struct. Meaning
54 * A. page->freelist -> List of object free in a page
55 * B. page->counters -> Counters of objects
56 * C. page->frozen -> frozen state
58 * If a slab is frozen then it is exempt from list management. It is not
59 * on any list. The processor that froze the slab is the one who can
60 * perform list operations on the page. Other processors may put objects
61 * onto the freelist but the processor that froze the slab is the only
62 * one that can retrieve the objects from the page's freelist.
64 * The list_lock protects the partial and full list on each node and
65 * the partial slab counter. If taken then no new slabs may be added or
66 * removed from the lists nor make the number of partial slabs be modified.
67 * (Note that the total number of slabs is an atomic value that may be
68 * modified without taking the list lock).
70 * The list_lock is a centralized lock and thus we avoid taking it as
71 * much as possible. As long as SLUB does not have to handle partial
72 * slabs, operations can continue without any centralized lock. F.e.
73 * allocating a long series of objects that fill up slabs does not require
75 * Interrupts are disabled during allocation and deallocation in order to
76 * make the slab allocator safe to use in the context of an irq. In addition
77 * interrupts are disabled to ensure that the processor does not change
78 * while handling per_cpu slabs, due to kernel preemption.
80 * SLUB assigns one slab for allocation to each processor.
81 * Allocations only occur from these slabs called cpu slabs.
83 * Slabs with free elements are kept on a partial list and during regular
84 * operations no list for full slabs is used. If an object in a full slab is
85 * freed then the slab will show up again on the partial lists.
86 * We track full slabs for debugging purposes though because otherwise we
87 * cannot scan all objects.
89 * Slabs are freed when they become empty. Teardown and setup is
90 * minimal so we rely on the page allocators per cpu caches for
91 * fast frees and allocs.
93 * Overloading of page flags that are otherwise used for LRU management.
95 * PageActive The slab is frozen and exempt from list processing.
96 * This means that the slab is dedicated to a purpose
97 * such as satisfying allocations for a specific
98 * processor. Objects may be freed in the slab while
99 * it is frozen but slab_free will then skip the usual
100 * list operations. It is up to the processor holding
101 * the slab to integrate the slab into the slab lists
102 * when the slab is no longer needed.
104 * One use of this flag is to mark slabs that are
105 * used for allocations. Then such a slab becomes a cpu
106 * slab. The cpu slab may be equipped with an additional
107 * freelist that allows lockless access to
108 * free objects in addition to the regular freelist
109 * that requires the slab lock.
111 * PageError Slab requires special handling due to debug
112 * options set. This moves slab handling out of
113 * the fast path and disables lockless freelists.
116 static inline int kmem_cache_debug(struct kmem_cache
*s
)
118 #ifdef CONFIG_SLUB_DEBUG
119 return unlikely(s
->flags
& SLAB_DEBUG_FLAGS
);
125 static inline bool kmem_cache_has_cpu_partial(struct kmem_cache
*s
)
127 #ifdef CONFIG_SLUB_CPU_PARTIAL
128 return !kmem_cache_debug(s
);
135 * Issues still to be resolved:
137 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
139 * - Variable sizing of the per node arrays
142 /* Enable to test recovery from slab corruption on boot */
143 #undef SLUB_RESILIENCY_TEST
145 /* Enable to log cmpxchg failures */
146 #undef SLUB_DEBUG_CMPXCHG
149 * Mininum number of partial slabs. These will be left on the partial
150 * lists even if they are empty. kmem_cache_shrink may reclaim them.
152 #define MIN_PARTIAL 5
155 * Maximum number of desirable partial slabs.
156 * The existence of more partial slabs makes kmem_cache_shrink
157 * sort the partial list by the number of objects in the.
159 #define MAX_PARTIAL 10
161 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
162 SLAB_POISON | SLAB_STORE_USER)
165 * Debugging flags that require metadata to be stored in the slab. These get
166 * disabled when slub_debug=O is used and a cache's min order increases with
169 #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
172 * Set of flags that will prevent slab merging
174 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
175 SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
178 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
179 SLAB_CACHE_DMA | SLAB_NOTRACK)
182 #define OO_MASK ((1 << OO_SHIFT) - 1)
183 #define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */
185 /* Internal SLUB flags */
186 #define __OBJECT_POISON 0x80000000UL /* Poison object */
187 #define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */
190 static struct notifier_block slab_notifier
;
194 * Tracking user of a slab.
196 #define TRACK_ADDRS_COUNT 16
198 unsigned long addr
; /* Called from address */
199 #ifdef CONFIG_STACKTRACE
200 unsigned long addrs
[TRACK_ADDRS_COUNT
]; /* Called from address */
202 int cpu
; /* Was running on cpu */
203 int pid
; /* Pid context */
204 unsigned long when
; /* When did the operation occur */
207 enum track_item
{ TRACK_ALLOC
, TRACK_FREE
};
210 static int sysfs_slab_add(struct kmem_cache
*);
211 static int sysfs_slab_alias(struct kmem_cache
*, const char *);
212 static void sysfs_slab_remove(struct kmem_cache
*);
213 static void memcg_propagate_slab_attrs(struct kmem_cache
*s
);
215 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
216 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
218 static inline void sysfs_slab_remove(struct kmem_cache
*s
) { }
220 static inline void memcg_propagate_slab_attrs(struct kmem_cache
*s
) { }
223 static inline void stat(const struct kmem_cache
*s
, enum stat_item si
)
225 #ifdef CONFIG_SLUB_STATS
226 __this_cpu_inc(s
->cpu_slab
->stat
[si
]);
230 /********************************************************************
231 * Core slab cache functions
232 *******************************************************************/
234 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
236 return s
->node
[node
];
239 /* Verify that a pointer has an address that is valid within a slab page */
240 static inline int check_valid_pointer(struct kmem_cache
*s
,
241 struct page
*page
, const void *object
)
248 base
= page_address(page
);
249 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
250 (object
- base
) % s
->size
) {
257 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
259 return *(void **)(object
+ s
->offset
);
262 static void prefetch_freepointer(const struct kmem_cache
*s
, void *object
)
264 prefetch(object
+ s
->offset
);
267 static inline void *get_freepointer_safe(struct kmem_cache
*s
, void *object
)
271 #ifdef CONFIG_DEBUG_PAGEALLOC
272 probe_kernel_read(&p
, (void **)(object
+ s
->offset
), sizeof(p
));
274 p
= get_freepointer(s
, object
);
279 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
281 *(void **)(object
+ s
->offset
) = fp
;
284 /* Loop over all objects in a slab */
285 #define for_each_object(__p, __s, __addr, __objects) \
286 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
289 /* Determine object index from a given position */
290 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
292 return (p
- addr
) / s
->size
;
295 static inline size_t slab_ksize(const struct kmem_cache
*s
)
297 #ifdef CONFIG_SLUB_DEBUG
299 * Debugging requires use of the padding between object
300 * and whatever may come after it.
302 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
303 return s
->object_size
;
307 * If we have the need to store the freelist pointer
308 * back there or track user information then we can
309 * only use the space before that information.
311 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
314 * Else we can use all the padding etc for the allocation
319 static inline int order_objects(int order
, unsigned long size
, int reserved
)
321 return ((PAGE_SIZE
<< order
) - reserved
) / size
;
324 static inline struct kmem_cache_order_objects
oo_make(int order
,
325 unsigned long size
, int reserved
)
327 struct kmem_cache_order_objects x
= {
328 (order
<< OO_SHIFT
) + order_objects(order
, size
, reserved
)
334 static inline int oo_order(struct kmem_cache_order_objects x
)
336 return x
.x
>> OO_SHIFT
;
339 static inline int oo_objects(struct kmem_cache_order_objects x
)
341 return x
.x
& OO_MASK
;
345 * Per slab locking using the pagelock
347 static __always_inline
void slab_lock(struct page
*page
)
349 bit_spin_lock(PG_locked
, &page
->flags
);
352 static __always_inline
void slab_unlock(struct page
*page
)
354 __bit_spin_unlock(PG_locked
, &page
->flags
);
357 /* Interrupts must be disabled (for the fallback code to work right) */
358 static inline bool __cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
359 void *freelist_old
, unsigned long counters_old
,
360 void *freelist_new
, unsigned long counters_new
,
363 VM_BUG_ON(!irqs_disabled());
364 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
365 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
366 if (s
->flags
& __CMPXCHG_DOUBLE
) {
367 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
368 freelist_old
, counters_old
,
369 freelist_new
, counters_new
))
375 if (page
->freelist
== freelist_old
&& page
->counters
== counters_old
) {
376 page
->freelist
= freelist_new
;
377 page
->counters
= counters_new
;
385 stat(s
, CMPXCHG_DOUBLE_FAIL
);
387 #ifdef SLUB_DEBUG_CMPXCHG
388 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
394 static inline bool cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
395 void *freelist_old
, unsigned long counters_old
,
396 void *freelist_new
, unsigned long counters_new
,
399 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
400 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
401 if (s
->flags
& __CMPXCHG_DOUBLE
) {
402 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
403 freelist_old
, counters_old
,
404 freelist_new
, counters_new
))
411 local_irq_save(flags
);
413 if (page
->freelist
== freelist_old
&& page
->counters
== counters_old
) {
414 page
->freelist
= freelist_new
;
415 page
->counters
= counters_new
;
417 local_irq_restore(flags
);
421 local_irq_restore(flags
);
425 stat(s
, CMPXCHG_DOUBLE_FAIL
);
427 #ifdef SLUB_DEBUG_CMPXCHG
428 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
434 #ifdef CONFIG_SLUB_DEBUG
436 * Determine a map of object in use on a page.
438 * Node listlock must be held to guarantee that the page does
439 * not vanish from under us.
441 static void get_map(struct kmem_cache
*s
, struct page
*page
, unsigned long *map
)
444 void *addr
= page_address(page
);
446 for (p
= page
->freelist
; p
; p
= get_freepointer(s
, p
))
447 set_bit(slab_index(p
, s
, addr
), map
);
453 #ifdef CONFIG_SLUB_DEBUG_ON
454 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
456 static int slub_debug
;
459 static char *slub_debug_slabs
;
460 static int disable_higher_order_debug
;
465 static void print_section(char *text
, u8
*addr
, unsigned int length
)
467 print_hex_dump(KERN_ERR
, text
, DUMP_PREFIX_ADDRESS
, 16, 1, addr
,
471 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
472 enum track_item alloc
)
477 p
= object
+ s
->offset
+ sizeof(void *);
479 p
= object
+ s
->inuse
;
484 static void set_track(struct kmem_cache
*s
, void *object
,
485 enum track_item alloc
, unsigned long addr
)
487 struct track
*p
= get_track(s
, object
, alloc
);
490 #ifdef CONFIG_STACKTRACE
491 struct stack_trace trace
;
494 trace
.nr_entries
= 0;
495 trace
.max_entries
= TRACK_ADDRS_COUNT
;
496 trace
.entries
= p
->addrs
;
498 save_stack_trace(&trace
);
500 /* See rant in lockdep.c */
501 if (trace
.nr_entries
!= 0 &&
502 trace
.entries
[trace
.nr_entries
- 1] == ULONG_MAX
)
505 for (i
= trace
.nr_entries
; i
< TRACK_ADDRS_COUNT
; i
++)
509 p
->cpu
= smp_processor_id();
510 p
->pid
= current
->pid
;
513 memset(p
, 0, sizeof(struct track
));
516 static void init_tracking(struct kmem_cache
*s
, void *object
)
518 if (!(s
->flags
& SLAB_STORE_USER
))
521 set_track(s
, object
, TRACK_FREE
, 0UL);
522 set_track(s
, object
, TRACK_ALLOC
, 0UL);
525 static void print_track(const char *s
, struct track
*t
)
530 printk(KERN_ERR
"INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
531 s
, (void *)t
->addr
, jiffies
- t
->when
, t
->cpu
, t
->pid
);
532 #ifdef CONFIG_STACKTRACE
535 for (i
= 0; i
< TRACK_ADDRS_COUNT
; i
++)
537 printk(KERN_ERR
"\t%pS\n", (void *)t
->addrs
[i
]);
544 static void print_tracking(struct kmem_cache
*s
, void *object
)
546 if (!(s
->flags
& SLAB_STORE_USER
))
549 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
550 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
553 static void print_page_info(struct page
*page
)
555 printk(KERN_ERR
"INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
556 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
560 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
566 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
568 printk(KERN_ERR
"========================================"
569 "=====================================\n");
570 printk(KERN_ERR
"BUG %s (%s): %s\n", s
->name
, print_tainted(), buf
);
571 printk(KERN_ERR
"----------------------------------------"
572 "-------------------------------------\n\n");
574 add_taint(TAINT_BAD_PAGE
);
577 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
583 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
585 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
588 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
590 unsigned int off
; /* Offset of last byte */
591 u8
*addr
= page_address(page
);
593 print_tracking(s
, p
);
595 print_page_info(page
);
597 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
598 p
, p
- addr
, get_freepointer(s
, p
));
601 print_section("Bytes b4 ", p
- 16, 16);
603 print_section("Object ", p
, min_t(unsigned long, s
->object_size
,
605 if (s
->flags
& SLAB_RED_ZONE
)
606 print_section("Redzone ", p
+ s
->object_size
,
607 s
->inuse
- s
->object_size
);
610 off
= s
->offset
+ sizeof(void *);
614 if (s
->flags
& SLAB_STORE_USER
)
615 off
+= 2 * sizeof(struct track
);
618 /* Beginning of the filler is the free pointer */
619 print_section("Padding ", p
+ off
, s
->size
- off
);
624 static void object_err(struct kmem_cache
*s
, struct page
*page
,
625 u8
*object
, char *reason
)
627 slab_bug(s
, "%s", reason
);
628 print_trailer(s
, page
, object
);
631 static void slab_err(struct kmem_cache
*s
, struct page
*page
, const char *fmt
, ...)
637 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
639 slab_bug(s
, "%s", buf
);
640 print_page_info(page
);
644 static void init_object(struct kmem_cache
*s
, void *object
, u8 val
)
648 if (s
->flags
& __OBJECT_POISON
) {
649 memset(p
, POISON_FREE
, s
->object_size
- 1);
650 p
[s
->object_size
- 1] = POISON_END
;
653 if (s
->flags
& SLAB_RED_ZONE
)
654 memset(p
+ s
->object_size
, val
, s
->inuse
- s
->object_size
);
657 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
658 void *from
, void *to
)
660 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
661 memset(from
, data
, to
- from
);
664 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
665 u8
*object
, char *what
,
666 u8
*start
, unsigned int value
, unsigned int bytes
)
671 fault
= memchr_inv(start
, value
, bytes
);
676 while (end
> fault
&& end
[-1] == value
)
679 slab_bug(s
, "%s overwritten", what
);
680 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
681 fault
, end
- 1, fault
[0], value
);
682 print_trailer(s
, page
, object
);
684 restore_bytes(s
, what
, value
, fault
, end
);
692 * Bytes of the object to be managed.
693 * If the freepointer may overlay the object then the free
694 * pointer is the first word of the object.
696 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
699 * object + s->object_size
700 * Padding to reach word boundary. This is also used for Redzoning.
701 * Padding is extended by another word if Redzoning is enabled and
702 * object_size == inuse.
704 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
705 * 0xcc (RED_ACTIVE) for objects in use.
708 * Meta data starts here.
710 * A. Free pointer (if we cannot overwrite object on free)
711 * B. Tracking data for SLAB_STORE_USER
712 * C. Padding to reach required alignment boundary or at mininum
713 * one word if debugging is on to be able to detect writes
714 * before the word boundary.
716 * Padding is done using 0x5a (POISON_INUSE)
719 * Nothing is used beyond s->size.
721 * If slabcaches are merged then the object_size and inuse boundaries are mostly
722 * ignored. And therefore no slab options that rely on these boundaries
723 * may be used with merged slabcaches.
726 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
728 unsigned long off
= s
->inuse
; /* The end of info */
731 /* Freepointer is placed after the object. */
732 off
+= sizeof(void *);
734 if (s
->flags
& SLAB_STORE_USER
)
735 /* We also have user information there */
736 off
+= 2 * sizeof(struct track
);
741 return check_bytes_and_report(s
, page
, p
, "Object padding",
742 p
+ off
, POISON_INUSE
, s
->size
- off
);
745 /* Check the pad bytes at the end of a slab page */
746 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
754 if (!(s
->flags
& SLAB_POISON
))
757 start
= page_address(page
);
758 length
= (PAGE_SIZE
<< compound_order(page
)) - s
->reserved
;
759 end
= start
+ length
;
760 remainder
= length
% s
->size
;
764 fault
= memchr_inv(end
- remainder
, POISON_INUSE
, remainder
);
767 while (end
> fault
&& end
[-1] == POISON_INUSE
)
770 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
771 print_section("Padding ", end
- remainder
, remainder
);
773 restore_bytes(s
, "slab padding", POISON_INUSE
, end
- remainder
, end
);
777 static int check_object(struct kmem_cache
*s
, struct page
*page
,
778 void *object
, u8 val
)
781 u8
*endobject
= object
+ s
->object_size
;
783 if (s
->flags
& SLAB_RED_ZONE
) {
784 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
785 endobject
, val
, s
->inuse
- s
->object_size
))
788 if ((s
->flags
& SLAB_POISON
) && s
->object_size
< s
->inuse
) {
789 check_bytes_and_report(s
, page
, p
, "Alignment padding",
790 endobject
, POISON_INUSE
, s
->inuse
- s
->object_size
);
794 if (s
->flags
& SLAB_POISON
) {
795 if (val
!= SLUB_RED_ACTIVE
&& (s
->flags
& __OBJECT_POISON
) &&
796 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
797 POISON_FREE
, s
->object_size
- 1) ||
798 !check_bytes_and_report(s
, page
, p
, "Poison",
799 p
+ s
->object_size
- 1, POISON_END
, 1)))
802 * check_pad_bytes cleans up on its own.
804 check_pad_bytes(s
, page
, p
);
807 if (!s
->offset
&& val
== SLUB_RED_ACTIVE
)
809 * Object and freepointer overlap. Cannot check
810 * freepointer while object is allocated.
814 /* Check free pointer validity */
815 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
816 object_err(s
, page
, p
, "Freepointer corrupt");
818 * No choice but to zap it and thus lose the remainder
819 * of the free objects in this slab. May cause
820 * another error because the object count is now wrong.
822 set_freepointer(s
, p
, NULL
);
828 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
832 VM_BUG_ON(!irqs_disabled());
834 if (!PageSlab(page
)) {
835 slab_err(s
, page
, "Not a valid slab page");
839 maxobj
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
840 if (page
->objects
> maxobj
) {
841 slab_err(s
, page
, "objects %u > max %u",
842 s
->name
, page
->objects
, maxobj
);
845 if (page
->inuse
> page
->objects
) {
846 slab_err(s
, page
, "inuse %u > max %u",
847 s
->name
, page
->inuse
, page
->objects
);
850 /* Slab_pad_check fixes things up after itself */
851 slab_pad_check(s
, page
);
856 * Determine if a certain object on a page is on the freelist. Must hold the
857 * slab lock to guarantee that the chains are in a consistent state.
859 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
864 unsigned long max_objects
;
867 while (fp
&& nr
<= page
->objects
) {
870 if (!check_valid_pointer(s
, page
, fp
)) {
872 object_err(s
, page
, object
,
873 "Freechain corrupt");
874 set_freepointer(s
, object
, NULL
);
877 slab_err(s
, page
, "Freepointer corrupt");
878 page
->freelist
= NULL
;
879 page
->inuse
= page
->objects
;
880 slab_fix(s
, "Freelist cleared");
886 fp
= get_freepointer(s
, object
);
890 max_objects
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
891 if (max_objects
> MAX_OBJS_PER_PAGE
)
892 max_objects
= MAX_OBJS_PER_PAGE
;
894 if (page
->objects
!= max_objects
) {
895 slab_err(s
, page
, "Wrong number of objects. Found %d but "
896 "should be %d", page
->objects
, max_objects
);
897 page
->objects
= max_objects
;
898 slab_fix(s
, "Number of objects adjusted.");
900 if (page
->inuse
!= page
->objects
- nr
) {
901 slab_err(s
, page
, "Wrong object count. Counter is %d but "
902 "counted were %d", page
->inuse
, page
->objects
- nr
);
903 page
->inuse
= page
->objects
- nr
;
904 slab_fix(s
, "Object count adjusted.");
906 return search
== NULL
;
909 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
,
912 if (s
->flags
& SLAB_TRACE
) {
913 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
915 alloc
? "alloc" : "free",
920 print_section("Object ", (void *)object
, s
->object_size
);
927 * Hooks for other subsystems that check memory allocations. In a typical
928 * production configuration these hooks all should produce no code at all.
930 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
932 flags
&= gfp_allowed_mask
;
933 lockdep_trace_alloc(flags
);
934 might_sleep_if(flags
& __GFP_WAIT
);
936 return should_failslab(s
->object_size
, flags
, s
->flags
);
939 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
, void *object
)
941 flags
&= gfp_allowed_mask
;
942 kmemcheck_slab_alloc(s
, flags
, object
, slab_ksize(s
));
943 kmemleak_alloc_recursive(object
, s
->object_size
, 1, s
->flags
, flags
);
946 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
)
948 kmemleak_free_recursive(x
, s
->flags
);
951 * Trouble is that we may no longer disable interupts in the fast path
952 * So in order to make the debug calls that expect irqs to be
953 * disabled we need to disable interrupts temporarily.
955 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
959 local_irq_save(flags
);
960 kmemcheck_slab_free(s
, x
, s
->object_size
);
961 debug_check_no_locks_freed(x
, s
->object_size
);
962 local_irq_restore(flags
);
965 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
966 debug_check_no_obj_freed(x
, s
->object_size
);
970 * Tracking of fully allocated slabs for debugging purposes.
972 * list_lock must be held.
974 static void add_full(struct kmem_cache
*s
,
975 struct kmem_cache_node
*n
, struct page
*page
)
977 if (!(s
->flags
& SLAB_STORE_USER
))
980 list_add(&page
->lru
, &n
->full
);
984 * list_lock must be held.
986 static void remove_full(struct kmem_cache
*s
, struct page
*page
)
988 if (!(s
->flags
& SLAB_STORE_USER
))
991 list_del(&page
->lru
);
994 /* Tracking of the number of slabs for debugging purposes */
995 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
997 struct kmem_cache_node
*n
= get_node(s
, node
);
999 return atomic_long_read(&n
->nr_slabs
);
1002 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1004 return atomic_long_read(&n
->nr_slabs
);
1007 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1009 struct kmem_cache_node
*n
= get_node(s
, node
);
1012 * May be called early in order to allocate a slab for the
1013 * kmem_cache_node structure. Solve the chicken-egg
1014 * dilemma by deferring the increment of the count during
1015 * bootstrap (see early_kmem_cache_node_alloc).
1018 atomic_long_inc(&n
->nr_slabs
);
1019 atomic_long_add(objects
, &n
->total_objects
);
1022 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1024 struct kmem_cache_node
*n
= get_node(s
, node
);
1026 atomic_long_dec(&n
->nr_slabs
);
1027 atomic_long_sub(objects
, &n
->total_objects
);
1030 /* Object debug checks for alloc/free paths */
1031 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
1034 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
1037 init_object(s
, object
, SLUB_RED_INACTIVE
);
1038 init_tracking(s
, object
);
1041 static noinline
int alloc_debug_processing(struct kmem_cache
*s
, struct page
*page
,
1042 void *object
, unsigned long addr
)
1044 if (!check_slab(s
, page
))
1047 if (!check_valid_pointer(s
, page
, object
)) {
1048 object_err(s
, page
, object
, "Freelist Pointer check fails");
1052 if (!check_object(s
, page
, object
, SLUB_RED_INACTIVE
))
1055 /* Success perform special debug activities for allocs */
1056 if (s
->flags
& SLAB_STORE_USER
)
1057 set_track(s
, object
, TRACK_ALLOC
, addr
);
1058 trace(s
, page
, object
, 1);
1059 init_object(s
, object
, SLUB_RED_ACTIVE
);
1063 if (PageSlab(page
)) {
1065 * If this is a slab page then lets do the best we can
1066 * to avoid issues in the future. Marking all objects
1067 * as used avoids touching the remaining objects.
1069 slab_fix(s
, "Marking all objects used");
1070 page
->inuse
= page
->objects
;
1071 page
->freelist
= NULL
;
1076 static noinline
struct kmem_cache_node
*free_debug_processing(
1077 struct kmem_cache
*s
, struct page
*page
, void *object
,
1078 unsigned long addr
, unsigned long *flags
)
1080 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1082 spin_lock_irqsave(&n
->list_lock
, *flags
);
1085 if (!check_slab(s
, page
))
1088 if (!check_valid_pointer(s
, page
, object
)) {
1089 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
1093 if (on_freelist(s
, page
, object
)) {
1094 object_err(s
, page
, object
, "Object already free");
1098 if (!check_object(s
, page
, object
, SLUB_RED_ACTIVE
))
1101 if (unlikely(s
!= page
->slab_cache
)) {
1102 if (!PageSlab(page
)) {
1103 slab_err(s
, page
, "Attempt to free object(0x%p) "
1104 "outside of slab", object
);
1105 } else if (!page
->slab_cache
) {
1107 "SLUB <none>: no slab for object 0x%p.\n",
1111 object_err(s
, page
, object
,
1112 "page slab pointer corrupt.");
1116 if (s
->flags
& SLAB_STORE_USER
)
1117 set_track(s
, object
, TRACK_FREE
, addr
);
1118 trace(s
, page
, object
, 0);
1119 init_object(s
, object
, SLUB_RED_INACTIVE
);
1123 * Keep node_lock to preserve integrity
1124 * until the object is actually freed
1130 spin_unlock_irqrestore(&n
->list_lock
, *flags
);
1131 slab_fix(s
, "Object at 0x%p not freed", object
);
1135 static int __init
setup_slub_debug(char *str
)
1137 slub_debug
= DEBUG_DEFAULT_FLAGS
;
1138 if (*str
++ != '=' || !*str
)
1140 * No options specified. Switch on full debugging.
1146 * No options but restriction on slabs. This means full
1147 * debugging for slabs matching a pattern.
1151 if (tolower(*str
) == 'o') {
1153 * Avoid enabling debugging on caches if its minimum order
1154 * would increase as a result.
1156 disable_higher_order_debug
= 1;
1163 * Switch off all debugging measures.
1168 * Determine which debug features should be switched on
1170 for (; *str
&& *str
!= ','; str
++) {
1171 switch (tolower(*str
)) {
1173 slub_debug
|= SLAB_DEBUG_FREE
;
1176 slub_debug
|= SLAB_RED_ZONE
;
1179 slub_debug
|= SLAB_POISON
;
1182 slub_debug
|= SLAB_STORE_USER
;
1185 slub_debug
|= SLAB_TRACE
;
1188 slub_debug
|= SLAB_FAILSLAB
;
1191 printk(KERN_ERR
"slub_debug option '%c' "
1192 "unknown. skipped\n", *str
);
1198 slub_debug_slabs
= str
+ 1;
1203 __setup("slub_debug", setup_slub_debug
);
1205 static unsigned long kmem_cache_flags(unsigned long object_size
,
1206 unsigned long flags
, const char *name
,
1207 void (*ctor
)(void *))
1210 * Enable debugging if selected on the kernel commandline.
1212 if (slub_debug
&& (!slub_debug_slabs
||
1213 !strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
))))
1214 flags
|= slub_debug
;
1219 static inline void setup_object_debug(struct kmem_cache
*s
,
1220 struct page
*page
, void *object
) {}
1222 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1223 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1225 static inline struct kmem_cache_node
*free_debug_processing(
1226 struct kmem_cache
*s
, struct page
*page
, void *object
,
1227 unsigned long addr
, unsigned long *flags
) { return NULL
; }
1229 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1231 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1232 void *object
, u8 val
) { return 1; }
1233 static inline void add_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1234 struct page
*page
) {}
1235 static inline void remove_full(struct kmem_cache
*s
, struct page
*page
) {}
1236 static inline unsigned long kmem_cache_flags(unsigned long object_size
,
1237 unsigned long flags
, const char *name
,
1238 void (*ctor
)(void *))
1242 #define slub_debug 0
1244 #define disable_higher_order_debug 0
1246 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1248 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1250 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1252 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1255 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
1258 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
,
1261 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
) {}
1263 #endif /* CONFIG_SLUB_DEBUG */
1266 * Slab allocation and freeing
1268 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1269 struct kmem_cache_order_objects oo
)
1271 int order
= oo_order(oo
);
1273 flags
|= __GFP_NOTRACK
;
1275 if (node
== NUMA_NO_NODE
)
1276 return alloc_pages(flags
, order
);
1278 return alloc_pages_exact_node(node
, flags
, order
);
1281 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1284 struct kmem_cache_order_objects oo
= s
->oo
;
1287 flags
&= gfp_allowed_mask
;
1289 if (flags
& __GFP_WAIT
)
1292 flags
|= s
->allocflags
;
1295 * Let the initial higher-order allocation fail under memory pressure
1296 * so we fall-back to the minimum order allocation.
1298 alloc_gfp
= (flags
| __GFP_NOWARN
| __GFP_NORETRY
) & ~__GFP_NOFAIL
;
1300 page
= alloc_slab_page(alloc_gfp
, node
, oo
);
1301 if (unlikely(!page
)) {
1304 * Allocation may have failed due to fragmentation.
1305 * Try a lower order alloc if possible
1307 page
= alloc_slab_page(flags
, node
, oo
);
1310 stat(s
, ORDER_FALLBACK
);
1313 if (kmemcheck_enabled
&& page
1314 && !(s
->flags
& (SLAB_NOTRACK
| DEBUG_DEFAULT_FLAGS
))) {
1315 int pages
= 1 << oo_order(oo
);
1317 kmemcheck_alloc_shadow(page
, oo_order(oo
), flags
, node
);
1320 * Objects from caches that have a constructor don't get
1321 * cleared when they're allocated, so we need to do it here.
1324 kmemcheck_mark_uninitialized_pages(page
, pages
);
1326 kmemcheck_mark_unallocated_pages(page
, pages
);
1329 if (flags
& __GFP_WAIT
)
1330 local_irq_disable();
1334 page
->objects
= oo_objects(oo
);
1335 mod_zone_page_state(page_zone(page
),
1336 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1337 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1343 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1346 setup_object_debug(s
, page
, object
);
1347 if (unlikely(s
->ctor
))
1351 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1359 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1361 page
= allocate_slab(s
,
1362 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1366 order
= compound_order(page
);
1367 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1368 memcg_bind_pages(s
, order
);
1369 page
->slab_cache
= s
;
1370 __SetPageSlab(page
);
1371 if (page
->pfmemalloc
)
1372 SetPageSlabPfmemalloc(page
);
1374 start
= page_address(page
);
1376 if (unlikely(s
->flags
& SLAB_POISON
))
1377 memset(start
, POISON_INUSE
, PAGE_SIZE
<< order
);
1380 for_each_object(p
, s
, start
, page
->objects
) {
1381 setup_object(s
, page
, last
);
1382 set_freepointer(s
, last
, p
);
1385 setup_object(s
, page
, last
);
1386 set_freepointer(s
, last
, NULL
);
1388 page
->freelist
= start
;
1389 page
->inuse
= page
->objects
;
1395 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1397 int order
= compound_order(page
);
1398 int pages
= 1 << order
;
1400 if (kmem_cache_debug(s
)) {
1403 slab_pad_check(s
, page
);
1404 for_each_object(p
, s
, page_address(page
),
1406 check_object(s
, page
, p
, SLUB_RED_INACTIVE
);
1409 kmemcheck_free_shadow(page
, compound_order(page
));
1411 mod_zone_page_state(page_zone(page
),
1412 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1413 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1416 __ClearPageSlabPfmemalloc(page
);
1417 __ClearPageSlab(page
);
1419 memcg_release_pages(s
, order
);
1420 reset_page_mapcount(page
);
1421 if (current
->reclaim_state
)
1422 current
->reclaim_state
->reclaimed_slab
+= pages
;
1423 __free_memcg_kmem_pages(page
, order
);
1426 #define need_reserve_slab_rcu \
1427 (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
1429 static void rcu_free_slab(struct rcu_head
*h
)
1433 if (need_reserve_slab_rcu
)
1434 page
= virt_to_head_page(h
);
1436 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1438 __free_slab(page
->slab_cache
, page
);
1441 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1443 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1444 struct rcu_head
*head
;
1446 if (need_reserve_slab_rcu
) {
1447 int order
= compound_order(page
);
1448 int offset
= (PAGE_SIZE
<< order
) - s
->reserved
;
1450 VM_BUG_ON(s
->reserved
!= sizeof(*head
));
1451 head
= page_address(page
) + offset
;
1454 * RCU free overloads the RCU head over the LRU
1456 head
= (void *)&page
->lru
;
1459 call_rcu(head
, rcu_free_slab
);
1461 __free_slab(s
, page
);
1464 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1466 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1471 * Management of partially allocated slabs.
1473 * list_lock must be held.
1475 static inline void add_partial(struct kmem_cache_node
*n
,
1476 struct page
*page
, int tail
)
1479 if (tail
== DEACTIVATE_TO_TAIL
)
1480 list_add_tail(&page
->lru
, &n
->partial
);
1482 list_add(&page
->lru
, &n
->partial
);
1486 * list_lock must be held.
1488 static inline void remove_partial(struct kmem_cache_node
*n
,
1491 list_del(&page
->lru
);
1496 * Remove slab from the partial list, freeze it and
1497 * return the pointer to the freelist.
1499 * Returns a list of objects or NULL if it fails.
1501 * Must hold list_lock since we modify the partial list.
1503 static inline void *acquire_slab(struct kmem_cache
*s
,
1504 struct kmem_cache_node
*n
, struct page
*page
,
1505 int mode
, int *objects
)
1508 unsigned long counters
;
1512 * Zap the freelist and set the frozen bit.
1513 * The old freelist is the list of objects for the
1514 * per cpu allocation list.
1516 freelist
= page
->freelist
;
1517 counters
= page
->counters
;
1518 new.counters
= counters
;
1519 *objects
= new.objects
- new.inuse
;
1521 new.inuse
= page
->objects
;
1522 new.freelist
= NULL
;
1524 new.freelist
= freelist
;
1527 VM_BUG_ON(new.frozen
);
1530 if (!__cmpxchg_double_slab(s
, page
,
1532 new.freelist
, new.counters
,
1536 remove_partial(n
, page
);
1541 static void put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
);
1542 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
);
1545 * Try to allocate a partial slab from a specific node.
1547 static void *get_partial_node(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1548 struct kmem_cache_cpu
*c
, gfp_t flags
)
1550 struct page
*page
, *page2
;
1551 void *object
= NULL
;
1556 * Racy check. If we mistakenly see no partial slabs then we
1557 * just allocate an empty slab. If we mistakenly try to get a
1558 * partial slab and there is none available then get_partials()
1561 if (!n
|| !n
->nr_partial
)
1564 spin_lock(&n
->list_lock
);
1565 list_for_each_entry_safe(page
, page2
, &n
->partial
, lru
) {
1568 if (!pfmemalloc_match(page
, flags
))
1571 t
= acquire_slab(s
, n
, page
, object
== NULL
, &objects
);
1575 available
+= objects
;
1578 stat(s
, ALLOC_FROM_PARTIAL
);
1581 put_cpu_partial(s
, page
, 0);
1582 stat(s
, CPU_PARTIAL_NODE
);
1584 if (!kmem_cache_has_cpu_partial(s
)
1585 || available
> s
->cpu_partial
/ 2)
1589 spin_unlock(&n
->list_lock
);
1594 * Get a page from somewhere. Search in increasing NUMA distances.
1596 static void *get_any_partial(struct kmem_cache
*s
, gfp_t flags
,
1597 struct kmem_cache_cpu
*c
)
1600 struct zonelist
*zonelist
;
1603 enum zone_type high_zoneidx
= gfp_zone(flags
);
1605 unsigned int cpuset_mems_cookie
;
1608 * The defrag ratio allows a configuration of the tradeoffs between
1609 * inter node defragmentation and node local allocations. A lower
1610 * defrag_ratio increases the tendency to do local allocations
1611 * instead of attempting to obtain partial slabs from other nodes.
1613 * If the defrag_ratio is set to 0 then kmalloc() always
1614 * returns node local objects. If the ratio is higher then kmalloc()
1615 * may return off node objects because partial slabs are obtained
1616 * from other nodes and filled up.
1618 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1619 * defrag_ratio = 1000) then every (well almost) allocation will
1620 * first attempt to defrag slab caches on other nodes. This means
1621 * scanning over all nodes to look for partial slabs which may be
1622 * expensive if we do it every time we are trying to find a slab
1623 * with available objects.
1625 if (!s
->remote_node_defrag_ratio
||
1626 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1630 cpuset_mems_cookie
= get_mems_allowed();
1631 zonelist
= node_zonelist(slab_node(), flags
);
1632 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
1633 struct kmem_cache_node
*n
;
1635 n
= get_node(s
, zone_to_nid(zone
));
1637 if (n
&& cpuset_zone_allowed_hardwall(zone
, flags
) &&
1638 n
->nr_partial
> s
->min_partial
) {
1639 object
= get_partial_node(s
, n
, c
, flags
);
1642 * Return the object even if
1643 * put_mems_allowed indicated that
1644 * the cpuset mems_allowed was
1645 * updated in parallel. It's a
1646 * harmless race between the alloc
1647 * and the cpuset update.
1649 put_mems_allowed(cpuset_mems_cookie
);
1654 } while (!put_mems_allowed(cpuset_mems_cookie
));
1660 * Get a partial page, lock it and return it.
1662 static void *get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
,
1663 struct kmem_cache_cpu
*c
)
1666 int searchnode
= (node
== NUMA_NO_NODE
) ? numa_node_id() : node
;
1668 object
= get_partial_node(s
, get_node(s
, searchnode
), c
, flags
);
1669 if (object
|| node
!= NUMA_NO_NODE
)
1672 return get_any_partial(s
, flags
, c
);
1675 #ifdef CONFIG_PREEMPT
1677 * Calculate the next globally unique transaction for disambiguiation
1678 * during cmpxchg. The transactions start with the cpu number and are then
1679 * incremented by CONFIG_NR_CPUS.
1681 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1684 * No preemption supported therefore also no need to check for
1690 static inline unsigned long next_tid(unsigned long tid
)
1692 return tid
+ TID_STEP
;
1695 static inline unsigned int tid_to_cpu(unsigned long tid
)
1697 return tid
% TID_STEP
;
1700 static inline unsigned long tid_to_event(unsigned long tid
)
1702 return tid
/ TID_STEP
;
1705 static inline unsigned int init_tid(int cpu
)
1710 static inline void note_cmpxchg_failure(const char *n
,
1711 const struct kmem_cache
*s
, unsigned long tid
)
1713 #ifdef SLUB_DEBUG_CMPXCHG
1714 unsigned long actual_tid
= __this_cpu_read(s
->cpu_slab
->tid
);
1716 printk(KERN_INFO
"%s %s: cmpxchg redo ", n
, s
->name
);
1718 #ifdef CONFIG_PREEMPT
1719 if (tid_to_cpu(tid
) != tid_to_cpu(actual_tid
))
1720 printk("due to cpu change %d -> %d\n",
1721 tid_to_cpu(tid
), tid_to_cpu(actual_tid
));
1724 if (tid_to_event(tid
) != tid_to_event(actual_tid
))
1725 printk("due to cpu running other code. Event %ld->%ld\n",
1726 tid_to_event(tid
), tid_to_event(actual_tid
));
1728 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1729 actual_tid
, tid
, next_tid(tid
));
1731 stat(s
, CMPXCHG_DOUBLE_CPU_FAIL
);
1734 static void init_kmem_cache_cpus(struct kmem_cache
*s
)
1738 for_each_possible_cpu(cpu
)
1739 per_cpu_ptr(s
->cpu_slab
, cpu
)->tid
= init_tid(cpu
);
1743 * Remove the cpu slab
1745 static void deactivate_slab(struct kmem_cache
*s
, struct page
*page
, void *freelist
)
1747 enum slab_modes
{ M_NONE
, M_PARTIAL
, M_FULL
, M_FREE
};
1748 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1750 enum slab_modes l
= M_NONE
, m
= M_NONE
;
1752 int tail
= DEACTIVATE_TO_HEAD
;
1756 if (page
->freelist
) {
1757 stat(s
, DEACTIVATE_REMOTE_FREES
);
1758 tail
= DEACTIVATE_TO_TAIL
;
1762 * Stage one: Free all available per cpu objects back
1763 * to the page freelist while it is still frozen. Leave the
1766 * There is no need to take the list->lock because the page
1769 while (freelist
&& (nextfree
= get_freepointer(s
, freelist
))) {
1771 unsigned long counters
;
1774 prior
= page
->freelist
;
1775 counters
= page
->counters
;
1776 set_freepointer(s
, freelist
, prior
);
1777 new.counters
= counters
;
1779 VM_BUG_ON(!new.frozen
);
1781 } while (!__cmpxchg_double_slab(s
, page
,
1783 freelist
, new.counters
,
1784 "drain percpu freelist"));
1786 freelist
= nextfree
;
1790 * Stage two: Ensure that the page is unfrozen while the
1791 * list presence reflects the actual number of objects
1794 * We setup the list membership and then perform a cmpxchg
1795 * with the count. If there is a mismatch then the page
1796 * is not unfrozen but the page is on the wrong list.
1798 * Then we restart the process which may have to remove
1799 * the page from the list that we just put it on again
1800 * because the number of objects in the slab may have
1805 old
.freelist
= page
->freelist
;
1806 old
.counters
= page
->counters
;
1807 VM_BUG_ON(!old
.frozen
);
1809 /* Determine target state of the slab */
1810 new.counters
= old
.counters
;
1813 set_freepointer(s
, freelist
, old
.freelist
);
1814 new.freelist
= freelist
;
1816 new.freelist
= old
.freelist
;
1820 if (!new.inuse
&& n
->nr_partial
> s
->min_partial
)
1822 else if (new.freelist
) {
1827 * Taking the spinlock removes the possiblity
1828 * that acquire_slab() will see a slab page that
1831 spin_lock(&n
->list_lock
);
1835 if (kmem_cache_debug(s
) && !lock
) {
1838 * This also ensures that the scanning of full
1839 * slabs from diagnostic functions will not see
1842 spin_lock(&n
->list_lock
);
1850 remove_partial(n
, page
);
1852 else if (l
== M_FULL
)
1854 remove_full(s
, page
);
1856 if (m
== M_PARTIAL
) {
1858 add_partial(n
, page
, tail
);
1861 } else if (m
== M_FULL
) {
1863 stat(s
, DEACTIVATE_FULL
);
1864 add_full(s
, n
, page
);
1870 if (!__cmpxchg_double_slab(s
, page
,
1871 old
.freelist
, old
.counters
,
1872 new.freelist
, new.counters
,
1877 spin_unlock(&n
->list_lock
);
1880 stat(s
, DEACTIVATE_EMPTY
);
1881 discard_slab(s
, page
);
1887 * Unfreeze all the cpu partial slabs.
1889 * This function must be called with interrupts disabled
1890 * for the cpu using c (or some other guarantee must be there
1891 * to guarantee no concurrent accesses).
1893 static void unfreeze_partials(struct kmem_cache
*s
,
1894 struct kmem_cache_cpu
*c
)
1896 #ifdef CONFIG_SLUB_CPU_PARTIAL
1897 struct kmem_cache_node
*n
= NULL
, *n2
= NULL
;
1898 struct page
*page
, *discard_page
= NULL
;
1900 while ((page
= c
->partial
)) {
1904 c
->partial
= page
->next
;
1906 n2
= get_node(s
, page_to_nid(page
));
1909 spin_unlock(&n
->list_lock
);
1912 spin_lock(&n
->list_lock
);
1917 old
.freelist
= page
->freelist
;
1918 old
.counters
= page
->counters
;
1919 VM_BUG_ON(!old
.frozen
);
1921 new.counters
= old
.counters
;
1922 new.freelist
= old
.freelist
;
1926 } while (!__cmpxchg_double_slab(s
, page
,
1927 old
.freelist
, old
.counters
,
1928 new.freelist
, new.counters
,
1929 "unfreezing slab"));
1931 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
)) {
1932 page
->next
= discard_page
;
1933 discard_page
= page
;
1935 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
1936 stat(s
, FREE_ADD_PARTIAL
);
1941 spin_unlock(&n
->list_lock
);
1943 while (discard_page
) {
1944 page
= discard_page
;
1945 discard_page
= discard_page
->next
;
1947 stat(s
, DEACTIVATE_EMPTY
);
1948 discard_slab(s
, page
);
1955 * Put a page that was just frozen (in __slab_free) into a partial page
1956 * slot if available. This is done without interrupts disabled and without
1957 * preemption disabled. The cmpxchg is racy and may put the partial page
1958 * onto a random cpus partial slot.
1960 * If we did not find a slot then simply move all the partials to the
1961 * per node partial list.
1963 static void put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
)
1965 #ifdef CONFIG_SLUB_CPU_PARTIAL
1966 struct page
*oldpage
;
1970 if (!s
->cpu_partial
)
1976 oldpage
= this_cpu_read(s
->cpu_slab
->partial
);
1979 pobjects
= oldpage
->pobjects
;
1980 pages
= oldpage
->pages
;
1981 if (drain
&& pobjects
> s
->cpu_partial
) {
1982 unsigned long flags
;
1984 * partial array is full. Move the existing
1985 * set to the per node partial list.
1987 local_irq_save(flags
);
1988 unfreeze_partials(s
, this_cpu_ptr(s
->cpu_slab
));
1989 local_irq_restore(flags
);
1993 stat(s
, CPU_PARTIAL_DRAIN
);
1998 pobjects
+= page
->objects
- page
->inuse
;
2000 page
->pages
= pages
;
2001 page
->pobjects
= pobjects
;
2002 page
->next
= oldpage
;
2004 } while (this_cpu_cmpxchg(s
->cpu_slab
->partial
, oldpage
, page
) != oldpage
);
2008 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
2010 stat(s
, CPUSLAB_FLUSH
);
2011 deactivate_slab(s
, c
->page
, c
->freelist
);
2013 c
->tid
= next_tid(c
->tid
);
2021 * Called from IPI handler with interrupts disabled.
2023 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
2025 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2031 unfreeze_partials(s
, c
);
2035 static void flush_cpu_slab(void *d
)
2037 struct kmem_cache
*s
= d
;
2039 __flush_cpu_slab(s
, smp_processor_id());
2042 static bool has_cpu_slab(int cpu
, void *info
)
2044 struct kmem_cache
*s
= info
;
2045 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2047 return c
->page
|| c
->partial
;
2050 static void flush_all(struct kmem_cache
*s
)
2052 on_each_cpu_cond(has_cpu_slab
, flush_cpu_slab
, s
, 1, GFP_ATOMIC
);
2056 * Check if the objects in a per cpu structure fit numa
2057 * locality expectations.
2059 static inline int node_match(struct page
*page
, int node
)
2062 if (!page
|| (node
!= NUMA_NO_NODE
&& page_to_nid(page
) != node
))
2068 static int count_free(struct page
*page
)
2070 return page
->objects
- page
->inuse
;
2073 static unsigned long count_partial(struct kmem_cache_node
*n
,
2074 int (*get_count
)(struct page
*))
2076 unsigned long flags
;
2077 unsigned long x
= 0;
2080 spin_lock_irqsave(&n
->list_lock
, flags
);
2081 list_for_each_entry(page
, &n
->partial
, lru
)
2082 x
+= get_count(page
);
2083 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2087 static inline unsigned long node_nr_objs(struct kmem_cache_node
*n
)
2089 #ifdef CONFIG_SLUB_DEBUG
2090 return atomic_long_read(&n
->total_objects
);
2096 static noinline
void
2097 slab_out_of_memory(struct kmem_cache
*s
, gfp_t gfpflags
, int nid
)
2102 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
2104 printk(KERN_WARNING
" cache: %s, object size: %d, buffer size: %d, "
2105 "default order: %d, min order: %d\n", s
->name
, s
->object_size
,
2106 s
->size
, oo_order(s
->oo
), oo_order(s
->min
));
2108 if (oo_order(s
->min
) > get_order(s
->object_size
))
2109 printk(KERN_WARNING
" %s debugging increased min order, use "
2110 "slub_debug=O to disable.\n", s
->name
);
2112 for_each_online_node(node
) {
2113 struct kmem_cache_node
*n
= get_node(s
, node
);
2114 unsigned long nr_slabs
;
2115 unsigned long nr_objs
;
2116 unsigned long nr_free
;
2121 nr_free
= count_partial(n
, count_free
);
2122 nr_slabs
= node_nr_slabs(n
);
2123 nr_objs
= node_nr_objs(n
);
2126 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
2127 node
, nr_slabs
, nr_objs
, nr_free
);
2131 static inline void *new_slab_objects(struct kmem_cache
*s
, gfp_t flags
,
2132 int node
, struct kmem_cache_cpu
**pc
)
2135 struct kmem_cache_cpu
*c
= *pc
;
2138 freelist
= get_partial(s
, flags
, node
, c
);
2143 page
= new_slab(s
, flags
, node
);
2145 c
= __this_cpu_ptr(s
->cpu_slab
);
2150 * No other reference to the page yet so we can
2151 * muck around with it freely without cmpxchg
2153 freelist
= page
->freelist
;
2154 page
->freelist
= NULL
;
2156 stat(s
, ALLOC_SLAB
);
2165 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
)
2167 if (unlikely(PageSlabPfmemalloc(page
)))
2168 return gfp_pfmemalloc_allowed(gfpflags
);
2174 * Check the page->freelist of a page and either transfer the freelist to the per cpu freelist
2175 * or deactivate the page.
2177 * The page is still frozen if the return value is not NULL.
2179 * If this function returns NULL then the page has been unfrozen.
2181 * This function must be called with interrupt disabled.
2183 static inline void *get_freelist(struct kmem_cache
*s
, struct page
*page
)
2186 unsigned long counters
;
2190 freelist
= page
->freelist
;
2191 counters
= page
->counters
;
2193 new.counters
= counters
;
2194 VM_BUG_ON(!new.frozen
);
2196 new.inuse
= page
->objects
;
2197 new.frozen
= freelist
!= NULL
;
2199 } while (!__cmpxchg_double_slab(s
, page
,
2208 * Slow path. The lockless freelist is empty or we need to perform
2211 * Processing is still very fast if new objects have been freed to the
2212 * regular freelist. In that case we simply take over the regular freelist
2213 * as the lockless freelist and zap the regular freelist.
2215 * If that is not working then we fall back to the partial lists. We take the
2216 * first element of the freelist as the object to allocate now and move the
2217 * rest of the freelist to the lockless freelist.
2219 * And if we were unable to get a new slab from the partial slab lists then
2220 * we need to allocate a new slab. This is the slowest path since it involves
2221 * a call to the page allocator and the setup of a new slab.
2223 static void *__slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, int node
,
2224 unsigned long addr
, struct kmem_cache_cpu
*c
)
2228 unsigned long flags
;
2230 local_irq_save(flags
);
2231 #ifdef CONFIG_PREEMPT
2233 * We may have been preempted and rescheduled on a different
2234 * cpu before disabling interrupts. Need to reload cpu area
2237 c
= this_cpu_ptr(s
->cpu_slab
);
2245 if (unlikely(!node_match(page
, node
))) {
2246 stat(s
, ALLOC_NODE_MISMATCH
);
2247 deactivate_slab(s
, page
, c
->freelist
);
2254 * By rights, we should be searching for a slab page that was
2255 * PFMEMALLOC but right now, we are losing the pfmemalloc
2256 * information when the page leaves the per-cpu allocator
2258 if (unlikely(!pfmemalloc_match(page
, gfpflags
))) {
2259 deactivate_slab(s
, page
, c
->freelist
);
2265 /* must check again c->freelist in case of cpu migration or IRQ */
2266 freelist
= c
->freelist
;
2270 stat(s
, ALLOC_SLOWPATH
);
2272 freelist
= get_freelist(s
, page
);
2276 stat(s
, DEACTIVATE_BYPASS
);
2280 stat(s
, ALLOC_REFILL
);
2284 * freelist is pointing to the list of objects to be used.
2285 * page is pointing to the page from which the objects are obtained.
2286 * That page must be frozen for per cpu allocations to work.
2288 VM_BUG_ON(!c
->page
->frozen
);
2289 c
->freelist
= get_freepointer(s
, freelist
);
2290 c
->tid
= next_tid(c
->tid
);
2291 local_irq_restore(flags
);
2297 page
= c
->page
= c
->partial
;
2298 c
->partial
= page
->next
;
2299 stat(s
, CPU_PARTIAL_ALLOC
);
2304 freelist
= new_slab_objects(s
, gfpflags
, node
, &c
);
2306 if (unlikely(!freelist
)) {
2307 if (!(gfpflags
& __GFP_NOWARN
) && printk_ratelimit())
2308 slab_out_of_memory(s
, gfpflags
, node
);
2310 local_irq_restore(flags
);
2315 if (likely(!kmem_cache_debug(s
) && pfmemalloc_match(page
, gfpflags
)))
2318 /* Only entered in the debug case */
2319 if (kmem_cache_debug(s
) && !alloc_debug_processing(s
, page
, freelist
, addr
))
2320 goto new_slab
; /* Slab failed checks. Next slab needed */
2322 deactivate_slab(s
, page
, get_freepointer(s
, freelist
));
2325 local_irq_restore(flags
);
2330 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
2331 * have the fastpath folded into their functions. So no function call
2332 * overhead for requests that can be satisfied on the fastpath.
2334 * The fastpath works by first checking if the lockless freelist can be used.
2335 * If not then __slab_alloc is called for slow processing.
2337 * Otherwise we can simply pick the next object from the lockless free list.
2339 static __always_inline
void *slab_alloc_node(struct kmem_cache
*s
,
2340 gfp_t gfpflags
, int node
, unsigned long addr
)
2343 struct kmem_cache_cpu
*c
;
2347 if (slab_pre_alloc_hook(s
, gfpflags
))
2350 s
= memcg_kmem_get_cache(s
, gfpflags
);
2353 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
2354 * enabled. We may switch back and forth between cpus while
2355 * reading from one cpu area. That does not matter as long
2356 * as we end up on the original cpu again when doing the cmpxchg.
2358 * Preemption is disabled for the retrieval of the tid because that
2359 * must occur from the current processor. We cannot allow rescheduling
2360 * on a different processor between the determination of the pointer
2361 * and the retrieval of the tid.
2364 c
= __this_cpu_ptr(s
->cpu_slab
);
2367 * The transaction ids are globally unique per cpu and per operation on
2368 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
2369 * occurs on the right processor and that there was no operation on the
2370 * linked list in between.
2375 object
= c
->freelist
;
2377 if (unlikely(!object
|| !page
|| !node_match(page
, node
)))
2378 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
2381 void *next_object
= get_freepointer_safe(s
, object
);
2384 * The cmpxchg will only match if there was no additional
2385 * operation and if we are on the right processor.
2387 * The cmpxchg does the following atomically (without lock semantics!)
2388 * 1. Relocate first pointer to the current per cpu area.
2389 * 2. Verify that tid and freelist have not been changed
2390 * 3. If they were not changed replace tid and freelist
2392 * Since this is without lock semantics the protection is only against
2393 * code executing on this cpu *not* from access by other cpus.
2395 if (unlikely(!this_cpu_cmpxchg_double(
2396 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2398 next_object
, next_tid(tid
)))) {
2400 note_cmpxchg_failure("slab_alloc", s
, tid
);
2403 prefetch_freepointer(s
, next_object
);
2404 stat(s
, ALLOC_FASTPATH
);
2407 if (unlikely(gfpflags
& __GFP_ZERO
) && object
)
2408 memset(object
, 0, s
->object_size
);
2410 slab_post_alloc_hook(s
, gfpflags
, object
);
2415 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
2416 gfp_t gfpflags
, unsigned long addr
)
2418 return slab_alloc_node(s
, gfpflags
, NUMA_NO_NODE
, addr
);
2421 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
2423 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2425 trace_kmem_cache_alloc(_RET_IP_
, ret
, s
->object_size
, s
->size
, gfpflags
);
2429 EXPORT_SYMBOL(kmem_cache_alloc
);
2431 #ifdef CONFIG_TRACING
2432 void *kmem_cache_alloc_trace(struct kmem_cache
*s
, gfp_t gfpflags
, size_t size
)
2434 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2435 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, gfpflags
);
2438 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
2440 void *kmalloc_order_trace(size_t size
, gfp_t flags
, unsigned int order
)
2442 void *ret
= kmalloc_order(size
, flags
, order
);
2443 trace_kmalloc(_RET_IP_
, ret
, size
, PAGE_SIZE
<< order
, flags
);
2446 EXPORT_SYMBOL(kmalloc_order_trace
);
2450 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
2452 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2454 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
2455 s
->object_size
, s
->size
, gfpflags
, node
);
2459 EXPORT_SYMBOL(kmem_cache_alloc_node
);
2461 #ifdef CONFIG_TRACING
2462 void *kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
2464 int node
, size_t size
)
2466 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2468 trace_kmalloc_node(_RET_IP_
, ret
,
2469 size
, s
->size
, gfpflags
, node
);
2472 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
2477 * Slow patch handling. This may still be called frequently since objects
2478 * have a longer lifetime than the cpu slabs in most processing loads.
2480 * So we still attempt to reduce cache line usage. Just take the slab
2481 * lock and free the item. If there is no additional partial page
2482 * handling required then we can return immediately.
2484 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
2485 void *x
, unsigned long addr
)
2488 void **object
= (void *)x
;
2491 unsigned long counters
;
2492 struct kmem_cache_node
*n
= NULL
;
2493 unsigned long uninitialized_var(flags
);
2495 stat(s
, FREE_SLOWPATH
);
2497 if (kmem_cache_debug(s
) &&
2498 !(n
= free_debug_processing(s
, page
, x
, addr
, &flags
)))
2503 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2506 prior
= page
->freelist
;
2507 counters
= page
->counters
;
2508 set_freepointer(s
, object
, prior
);
2509 new.counters
= counters
;
2510 was_frozen
= new.frozen
;
2512 if ((!new.inuse
|| !prior
) && !was_frozen
) {
2514 if (kmem_cache_has_cpu_partial(s
) && !prior
)
2517 * Slab was on no list before and will be partially empty
2518 * We can defer the list move and instead freeze it.
2522 else { /* Needs to be taken off a list */
2524 n
= get_node(s
, page_to_nid(page
));
2526 * Speculatively acquire the list_lock.
2527 * If the cmpxchg does not succeed then we may
2528 * drop the list_lock without any processing.
2530 * Otherwise the list_lock will synchronize with
2531 * other processors updating the list of slabs.
2533 spin_lock_irqsave(&n
->list_lock
, flags
);
2538 } while (!cmpxchg_double_slab(s
, page
,
2540 object
, new.counters
,
2546 * If we just froze the page then put it onto the
2547 * per cpu partial list.
2549 if (new.frozen
&& !was_frozen
) {
2550 put_cpu_partial(s
, page
, 1);
2551 stat(s
, CPU_PARTIAL_FREE
);
2554 * The list lock was not taken therefore no list
2555 * activity can be necessary.
2558 stat(s
, FREE_FROZEN
);
2562 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
))
2566 * Objects left in the slab. If it was not on the partial list before
2569 if (!kmem_cache_has_cpu_partial(s
) && unlikely(!prior
)) {
2570 if (kmem_cache_debug(s
))
2571 remove_full(s
, page
);
2572 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
2573 stat(s
, FREE_ADD_PARTIAL
);
2575 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2581 * Slab on the partial list.
2583 remove_partial(n
, page
);
2584 stat(s
, FREE_REMOVE_PARTIAL
);
2586 /* Slab must be on the full list */
2587 remove_full(s
, page
);
2589 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2591 discard_slab(s
, page
);
2595 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2596 * can perform fastpath freeing without additional function calls.
2598 * The fastpath is only possible if we are freeing to the current cpu slab
2599 * of this processor. This typically the case if we have just allocated
2602 * If fastpath is not possible then fall back to __slab_free where we deal
2603 * with all sorts of special processing.
2605 static __always_inline
void slab_free(struct kmem_cache
*s
,
2606 struct page
*page
, void *x
, unsigned long addr
)
2608 void **object
= (void *)x
;
2609 struct kmem_cache_cpu
*c
;
2612 slab_free_hook(s
, x
);
2616 * Determine the currently cpus per cpu slab.
2617 * The cpu may change afterward. However that does not matter since
2618 * data is retrieved via this pointer. If we are on the same cpu
2619 * during the cmpxchg then the free will succedd.
2622 c
= __this_cpu_ptr(s
->cpu_slab
);
2627 if (likely(page
== c
->page
)) {
2628 set_freepointer(s
, object
, c
->freelist
);
2630 if (unlikely(!this_cpu_cmpxchg_double(
2631 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2633 object
, next_tid(tid
)))) {
2635 note_cmpxchg_failure("slab_free", s
, tid
);
2638 stat(s
, FREE_FASTPATH
);
2640 __slab_free(s
, page
, x
, addr
);
2644 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
2646 s
= cache_from_obj(s
, x
);
2649 slab_free(s
, virt_to_head_page(x
), x
, _RET_IP_
);
2650 trace_kmem_cache_free(_RET_IP_
, x
);
2652 EXPORT_SYMBOL(kmem_cache_free
);
2655 * Object placement in a slab is made very easy because we always start at
2656 * offset 0. If we tune the size of the object to the alignment then we can
2657 * get the required alignment by putting one properly sized object after
2660 * Notice that the allocation order determines the sizes of the per cpu
2661 * caches. Each processor has always one slab available for allocations.
2662 * Increasing the allocation order reduces the number of times that slabs
2663 * must be moved on and off the partial lists and is therefore a factor in
2668 * Mininum / Maximum order of slab pages. This influences locking overhead
2669 * and slab fragmentation. A higher order reduces the number of partial slabs
2670 * and increases the number of allocations possible without having to
2671 * take the list_lock.
2673 static int slub_min_order
;
2674 static int slub_max_order
= PAGE_ALLOC_COSTLY_ORDER
;
2675 static int slub_min_objects
;
2678 * Merge control. If this is set then no merging of slab caches will occur.
2679 * (Could be removed. This was introduced to pacify the merge skeptics.)
2681 static int slub_nomerge
;
2684 * Calculate the order of allocation given an slab object size.
2686 * The order of allocation has significant impact on performance and other
2687 * system components. Generally order 0 allocations should be preferred since
2688 * order 0 does not cause fragmentation in the page allocator. Larger objects
2689 * be problematic to put into order 0 slabs because there may be too much
2690 * unused space left. We go to a higher order if more than 1/16th of the slab
2693 * In order to reach satisfactory performance we must ensure that a minimum
2694 * number of objects is in one slab. Otherwise we may generate too much
2695 * activity on the partial lists which requires taking the list_lock. This is
2696 * less a concern for large slabs though which are rarely used.
2698 * slub_max_order specifies the order where we begin to stop considering the
2699 * number of objects in a slab as critical. If we reach slub_max_order then
2700 * we try to keep the page order as low as possible. So we accept more waste
2701 * of space in favor of a small page order.
2703 * Higher order allocations also allow the placement of more objects in a
2704 * slab and thereby reduce object handling overhead. If the user has
2705 * requested a higher mininum order then we start with that one instead of
2706 * the smallest order which will fit the object.
2708 static inline int slab_order(int size
, int min_objects
,
2709 int max_order
, int fract_leftover
, int reserved
)
2713 int min_order
= slub_min_order
;
2715 if (order_objects(min_order
, size
, reserved
) > MAX_OBJS_PER_PAGE
)
2716 return get_order(size
* MAX_OBJS_PER_PAGE
) - 1;
2718 for (order
= max(min_order
,
2719 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
2720 order
<= max_order
; order
++) {
2722 unsigned long slab_size
= PAGE_SIZE
<< order
;
2724 if (slab_size
< min_objects
* size
+ reserved
)
2727 rem
= (slab_size
- reserved
) % size
;
2729 if (rem
<= slab_size
/ fract_leftover
)
2737 static inline int calculate_order(int size
, int reserved
)
2745 * Attempt to find best configuration for a slab. This
2746 * works by first attempting to generate a layout with
2747 * the best configuration and backing off gradually.
2749 * First we reduce the acceptable waste in a slab. Then
2750 * we reduce the minimum objects required in a slab.
2752 min_objects
= slub_min_objects
;
2754 min_objects
= 4 * (fls(nr_cpu_ids
) + 1);
2755 max_objects
= order_objects(slub_max_order
, size
, reserved
);
2756 min_objects
= min(min_objects
, max_objects
);
2758 while (min_objects
> 1) {
2760 while (fraction
>= 4) {
2761 order
= slab_order(size
, min_objects
,
2762 slub_max_order
, fraction
, reserved
);
2763 if (order
<= slub_max_order
)
2771 * We were unable to place multiple objects in a slab. Now
2772 * lets see if we can place a single object there.
2774 order
= slab_order(size
, 1, slub_max_order
, 1, reserved
);
2775 if (order
<= slub_max_order
)
2779 * Doh this slab cannot be placed using slub_max_order.
2781 order
= slab_order(size
, 1, MAX_ORDER
, 1, reserved
);
2782 if (order
< MAX_ORDER
)
2788 init_kmem_cache_node(struct kmem_cache_node
*n
)
2791 spin_lock_init(&n
->list_lock
);
2792 INIT_LIST_HEAD(&n
->partial
);
2793 #ifdef CONFIG_SLUB_DEBUG
2794 atomic_long_set(&n
->nr_slabs
, 0);
2795 atomic_long_set(&n
->total_objects
, 0);
2796 INIT_LIST_HEAD(&n
->full
);
2800 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
)
2802 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE
<
2803 KMALLOC_SHIFT_HIGH
* sizeof(struct kmem_cache_cpu
));
2806 * Must align to double word boundary for the double cmpxchg
2807 * instructions to work; see __pcpu_double_call_return_bool().
2809 s
->cpu_slab
= __alloc_percpu(sizeof(struct kmem_cache_cpu
),
2810 2 * sizeof(void *));
2815 init_kmem_cache_cpus(s
);
2820 static struct kmem_cache
*kmem_cache_node
;
2823 * No kmalloc_node yet so do it by hand. We know that this is the first
2824 * slab on the node for this slabcache. There are no concurrent accesses
2827 * Note that this function only works on the kmalloc_node_cache
2828 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2829 * memory on a fresh node that has no slab structures yet.
2831 static void early_kmem_cache_node_alloc(int node
)
2834 struct kmem_cache_node
*n
;
2836 BUG_ON(kmem_cache_node
->size
< sizeof(struct kmem_cache_node
));
2838 page
= new_slab(kmem_cache_node
, GFP_NOWAIT
, node
);
2841 if (page_to_nid(page
) != node
) {
2842 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2844 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2845 "in order to be able to continue\n");
2850 page
->freelist
= get_freepointer(kmem_cache_node
, n
);
2853 kmem_cache_node
->node
[node
] = n
;
2854 #ifdef CONFIG_SLUB_DEBUG
2855 init_object(kmem_cache_node
, n
, SLUB_RED_ACTIVE
);
2856 init_tracking(kmem_cache_node
, n
);
2858 init_kmem_cache_node(n
);
2859 inc_slabs_node(kmem_cache_node
, node
, page
->objects
);
2861 add_partial(n
, page
, DEACTIVATE_TO_HEAD
);
2864 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2868 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2869 struct kmem_cache_node
*n
= s
->node
[node
];
2872 kmem_cache_free(kmem_cache_node
, n
);
2874 s
->node
[node
] = NULL
;
2878 static int init_kmem_cache_nodes(struct kmem_cache
*s
)
2882 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2883 struct kmem_cache_node
*n
;
2885 if (slab_state
== DOWN
) {
2886 early_kmem_cache_node_alloc(node
);
2889 n
= kmem_cache_alloc_node(kmem_cache_node
,
2893 free_kmem_cache_nodes(s
);
2898 init_kmem_cache_node(n
);
2903 static void set_min_partial(struct kmem_cache
*s
, unsigned long min
)
2905 if (min
< MIN_PARTIAL
)
2907 else if (min
> MAX_PARTIAL
)
2909 s
->min_partial
= min
;
2913 * calculate_sizes() determines the order and the distribution of data within
2916 static int calculate_sizes(struct kmem_cache
*s
, int forced_order
)
2918 unsigned long flags
= s
->flags
;
2919 unsigned long size
= s
->object_size
;
2923 * Round up object size to the next word boundary. We can only
2924 * place the free pointer at word boundaries and this determines
2925 * the possible location of the free pointer.
2927 size
= ALIGN(size
, sizeof(void *));
2929 #ifdef CONFIG_SLUB_DEBUG
2931 * Determine if we can poison the object itself. If the user of
2932 * the slab may touch the object after free or before allocation
2933 * then we should never poison the object itself.
2935 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2937 s
->flags
|= __OBJECT_POISON
;
2939 s
->flags
&= ~__OBJECT_POISON
;
2943 * If we are Redzoning then check if there is some space between the
2944 * end of the object and the free pointer. If not then add an
2945 * additional word to have some bytes to store Redzone information.
2947 if ((flags
& SLAB_RED_ZONE
) && size
== s
->object_size
)
2948 size
+= sizeof(void *);
2952 * With that we have determined the number of bytes in actual use
2953 * by the object. This is the potential offset to the free pointer.
2957 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
2960 * Relocate free pointer after the object if it is not
2961 * permitted to overwrite the first word of the object on
2964 * This is the case if we do RCU, have a constructor or
2965 * destructor or are poisoning the objects.
2968 size
+= sizeof(void *);
2971 #ifdef CONFIG_SLUB_DEBUG
2972 if (flags
& SLAB_STORE_USER
)
2974 * Need to store information about allocs and frees after
2977 size
+= 2 * sizeof(struct track
);
2979 if (flags
& SLAB_RED_ZONE
)
2981 * Add some empty padding so that we can catch
2982 * overwrites from earlier objects rather than let
2983 * tracking information or the free pointer be
2984 * corrupted if a user writes before the start
2987 size
+= sizeof(void *);
2991 * SLUB stores one object immediately after another beginning from
2992 * offset 0. In order to align the objects we have to simply size
2993 * each object to conform to the alignment.
2995 size
= ALIGN(size
, s
->align
);
2997 if (forced_order
>= 0)
2998 order
= forced_order
;
3000 order
= calculate_order(size
, s
->reserved
);
3007 s
->allocflags
|= __GFP_COMP
;
3009 if (s
->flags
& SLAB_CACHE_DMA
)
3010 s
->allocflags
|= GFP_DMA
;
3012 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
3013 s
->allocflags
|= __GFP_RECLAIMABLE
;
3016 * Determine the number of objects per slab
3018 s
->oo
= oo_make(order
, size
, s
->reserved
);
3019 s
->min
= oo_make(get_order(size
), size
, s
->reserved
);
3020 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
3023 return !!oo_objects(s
->oo
);
3026 static int kmem_cache_open(struct kmem_cache
*s
, unsigned long flags
)
3028 s
->flags
= kmem_cache_flags(s
->size
, flags
, s
->name
, s
->ctor
);
3031 if (need_reserve_slab_rcu
&& (s
->flags
& SLAB_DESTROY_BY_RCU
))
3032 s
->reserved
= sizeof(struct rcu_head
);
3034 if (!calculate_sizes(s
, -1))
3036 if (disable_higher_order_debug
) {
3038 * Disable debugging flags that store metadata if the min slab
3041 if (get_order(s
->size
) > get_order(s
->object_size
)) {
3042 s
->flags
&= ~DEBUG_METADATA_FLAGS
;
3044 if (!calculate_sizes(s
, -1))
3049 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
3050 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
3051 if (system_has_cmpxchg_double() && (s
->flags
& SLAB_DEBUG_FLAGS
) == 0)
3052 /* Enable fast mode */
3053 s
->flags
|= __CMPXCHG_DOUBLE
;
3057 * The larger the object size is, the more pages we want on the partial
3058 * list to avoid pounding the page allocator excessively.
3060 set_min_partial(s
, ilog2(s
->size
) / 2);
3063 * cpu_partial determined the maximum number of objects kept in the
3064 * per cpu partial lists of a processor.
3066 * Per cpu partial lists mainly contain slabs that just have one
3067 * object freed. If they are used for allocation then they can be
3068 * filled up again with minimal effort. The slab will never hit the
3069 * per node partial lists and therefore no locking will be required.
3071 * This setting also determines
3073 * A) The number of objects from per cpu partial slabs dumped to the
3074 * per node list when we reach the limit.
3075 * B) The number of objects in cpu partial slabs to extract from the
3076 * per node list when we run out of per cpu objects. We only fetch 50%
3077 * to keep some capacity around for frees.
3079 if (!kmem_cache_has_cpu_partial(s
))
3081 else if (s
->size
>= PAGE_SIZE
)
3083 else if (s
->size
>= 1024)
3085 else if (s
->size
>= 256)
3086 s
->cpu_partial
= 13;
3088 s
->cpu_partial
= 30;
3091 s
->remote_node_defrag_ratio
= 1000;
3093 if (!init_kmem_cache_nodes(s
))
3096 if (alloc_kmem_cache_cpus(s
))
3099 free_kmem_cache_nodes(s
);
3101 if (flags
& SLAB_PANIC
)
3102 panic("Cannot create slab %s size=%lu realsize=%u "
3103 "order=%u offset=%u flags=%lx\n",
3104 s
->name
, (unsigned long)s
->size
, s
->size
, oo_order(s
->oo
),
3109 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
3112 #ifdef CONFIG_SLUB_DEBUG
3113 void *addr
= page_address(page
);
3115 unsigned long *map
= kzalloc(BITS_TO_LONGS(page
->objects
) *
3116 sizeof(long), GFP_ATOMIC
);
3119 slab_err(s
, page
, text
, s
->name
);
3122 get_map(s
, page
, map
);
3123 for_each_object(p
, s
, addr
, page
->objects
) {
3125 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
3126 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
3128 print_tracking(s
, p
);
3137 * Attempt to free all partial slabs on a node.
3138 * This is called from kmem_cache_close(). We must be the last thread
3139 * using the cache and therefore we do not need to lock anymore.
3141 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
3143 struct page
*page
, *h
;
3145 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
3147 remove_partial(n
, page
);
3148 discard_slab(s
, page
);
3150 list_slab_objects(s
, page
,
3151 "Objects remaining in %s on kmem_cache_close()");
3157 * Release all resources used by a slab cache.
3159 static inline int kmem_cache_close(struct kmem_cache
*s
)
3164 /* Attempt to free all objects */
3165 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3166 struct kmem_cache_node
*n
= get_node(s
, node
);
3169 if (n
->nr_partial
|| slabs_node(s
, node
))
3172 free_percpu(s
->cpu_slab
);
3173 free_kmem_cache_nodes(s
);
3177 int __kmem_cache_shutdown(struct kmem_cache
*s
)
3179 int rc
= kmem_cache_close(s
);
3183 * We do the same lock strategy around sysfs_slab_add, see
3184 * __kmem_cache_create. Because this is pretty much the last
3185 * operation we do and the lock will be released shortly after
3186 * that in slab_common.c, we could just move sysfs_slab_remove
3187 * to a later point in common code. We should do that when we
3188 * have a common sysfs framework for all allocators.
3190 mutex_unlock(&slab_mutex
);
3191 sysfs_slab_remove(s
);
3192 mutex_lock(&slab_mutex
);
3198 /********************************************************************
3200 *******************************************************************/
3202 static int __init
setup_slub_min_order(char *str
)
3204 get_option(&str
, &slub_min_order
);
3209 __setup("slub_min_order=", setup_slub_min_order
);
3211 static int __init
setup_slub_max_order(char *str
)
3213 get_option(&str
, &slub_max_order
);
3214 slub_max_order
= min(slub_max_order
, MAX_ORDER
- 1);
3219 __setup("slub_max_order=", setup_slub_max_order
);
3221 static int __init
setup_slub_min_objects(char *str
)
3223 get_option(&str
, &slub_min_objects
);
3228 __setup("slub_min_objects=", setup_slub_min_objects
);
3230 static int __init
setup_slub_nomerge(char *str
)
3236 __setup("slub_nomerge", setup_slub_nomerge
);
3238 void *__kmalloc(size_t size
, gfp_t flags
)
3240 struct kmem_cache
*s
;
3243 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
))
3244 return kmalloc_large(size
, flags
);
3246 s
= kmalloc_slab(size
, flags
);
3248 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3251 ret
= slab_alloc(s
, flags
, _RET_IP_
);
3253 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, flags
);
3257 EXPORT_SYMBOL(__kmalloc
);
3260 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
3265 flags
|= __GFP_COMP
| __GFP_NOTRACK
| __GFP_KMEMCG
;
3266 page
= alloc_pages_node(node
, flags
, get_order(size
));
3268 ptr
= page_address(page
);
3270 kmemleak_alloc(ptr
, size
, 1, flags
);
3274 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3276 struct kmem_cache
*s
;
3279 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
)) {
3280 ret
= kmalloc_large_node(size
, flags
, node
);
3282 trace_kmalloc_node(_RET_IP_
, ret
,
3283 size
, PAGE_SIZE
<< get_order(size
),
3289 s
= kmalloc_slab(size
, flags
);
3291 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3294 ret
= slab_alloc_node(s
, flags
, node
, _RET_IP_
);
3296 trace_kmalloc_node(_RET_IP_
, ret
, size
, s
->size
, flags
, node
);
3300 EXPORT_SYMBOL(__kmalloc_node
);
3303 size_t ksize(const void *object
)
3307 if (unlikely(object
== ZERO_SIZE_PTR
))
3310 page
= virt_to_head_page(object
);
3312 if (unlikely(!PageSlab(page
))) {
3313 WARN_ON(!PageCompound(page
));
3314 return PAGE_SIZE
<< compound_order(page
);
3317 return slab_ksize(page
->slab_cache
);
3319 EXPORT_SYMBOL(ksize
);
3321 #ifdef CONFIG_SLUB_DEBUG
3322 bool verify_mem_not_deleted(const void *x
)
3325 void *object
= (void *)x
;
3326 unsigned long flags
;
3329 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3332 local_irq_save(flags
);
3334 page
= virt_to_head_page(x
);
3335 if (unlikely(!PageSlab(page
))) {
3336 /* maybe it was from stack? */
3342 if (on_freelist(page
->slab_cache
, page
, object
)) {
3343 object_err(page
->slab_cache
, page
, object
, "Object is on free-list");
3351 local_irq_restore(flags
);
3354 EXPORT_SYMBOL(verify_mem_not_deleted
);
3357 void kfree(const void *x
)
3360 void *object
= (void *)x
;
3362 trace_kfree(_RET_IP_
, x
);
3364 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3367 page
= virt_to_head_page(x
);
3368 if (unlikely(!PageSlab(page
))) {
3369 BUG_ON(!PageCompound(page
));
3371 __free_memcg_kmem_pages(page
, compound_order(page
));
3374 slab_free(page
->slab_cache
, page
, object
, _RET_IP_
);
3376 EXPORT_SYMBOL(kfree
);
3379 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
3380 * the remaining slabs by the number of items in use. The slabs with the
3381 * most items in use come first. New allocations will then fill those up
3382 * and thus they can be removed from the partial lists.
3384 * The slabs with the least items are placed last. This results in them
3385 * being allocated from last increasing the chance that the last objects
3386 * are freed in them.
3388 int kmem_cache_shrink(struct kmem_cache
*s
)
3392 struct kmem_cache_node
*n
;
3395 int objects
= oo_objects(s
->max
);
3396 struct list_head
*slabs_by_inuse
=
3397 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
3398 unsigned long flags
;
3400 if (!slabs_by_inuse
)
3404 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3405 n
= get_node(s
, node
);
3410 for (i
= 0; i
< objects
; i
++)
3411 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
3413 spin_lock_irqsave(&n
->list_lock
, flags
);
3416 * Build lists indexed by the items in use in each slab.
3418 * Note that concurrent frees may occur while we hold the
3419 * list_lock. page->inuse here is the upper limit.
3421 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
3422 list_move(&page
->lru
, slabs_by_inuse
+ page
->inuse
);
3428 * Rebuild the partial list with the slabs filled up most
3429 * first and the least used slabs at the end.
3431 for (i
= objects
- 1; i
> 0; i
--)
3432 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
3434 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3436 /* Release empty slabs */
3437 list_for_each_entry_safe(page
, t
, slabs_by_inuse
, lru
)
3438 discard_slab(s
, page
);
3441 kfree(slabs_by_inuse
);
3444 EXPORT_SYMBOL(kmem_cache_shrink
);
3446 #if defined(CONFIG_MEMORY_HOTPLUG)
3447 static int slab_mem_going_offline_callback(void *arg
)
3449 struct kmem_cache
*s
;
3451 mutex_lock(&slab_mutex
);
3452 list_for_each_entry(s
, &slab_caches
, list
)
3453 kmem_cache_shrink(s
);
3454 mutex_unlock(&slab_mutex
);
3459 static void slab_mem_offline_callback(void *arg
)
3461 struct kmem_cache_node
*n
;
3462 struct kmem_cache
*s
;
3463 struct memory_notify
*marg
= arg
;
3466 offline_node
= marg
->status_change_nid_normal
;
3469 * If the node still has available memory. we need kmem_cache_node
3472 if (offline_node
< 0)
3475 mutex_lock(&slab_mutex
);
3476 list_for_each_entry(s
, &slab_caches
, list
) {
3477 n
= get_node(s
, offline_node
);
3480 * if n->nr_slabs > 0, slabs still exist on the node
3481 * that is going down. We were unable to free them,
3482 * and offline_pages() function shouldn't call this
3483 * callback. So, we must fail.
3485 BUG_ON(slabs_node(s
, offline_node
));
3487 s
->node
[offline_node
] = NULL
;
3488 kmem_cache_free(kmem_cache_node
, n
);
3491 mutex_unlock(&slab_mutex
);
3494 static int slab_mem_going_online_callback(void *arg
)
3496 struct kmem_cache_node
*n
;
3497 struct kmem_cache
*s
;
3498 struct memory_notify
*marg
= arg
;
3499 int nid
= marg
->status_change_nid_normal
;
3503 * If the node's memory is already available, then kmem_cache_node is
3504 * already created. Nothing to do.
3510 * We are bringing a node online. No memory is available yet. We must
3511 * allocate a kmem_cache_node structure in order to bring the node
3514 mutex_lock(&slab_mutex
);
3515 list_for_each_entry(s
, &slab_caches
, list
) {
3517 * XXX: kmem_cache_alloc_node will fallback to other nodes
3518 * since memory is not yet available from the node that
3521 n
= kmem_cache_alloc(kmem_cache_node
, GFP_KERNEL
);
3526 init_kmem_cache_node(n
);
3530 mutex_unlock(&slab_mutex
);
3534 static int slab_memory_callback(struct notifier_block
*self
,
3535 unsigned long action
, void *arg
)
3540 case MEM_GOING_ONLINE
:
3541 ret
= slab_mem_going_online_callback(arg
);
3543 case MEM_GOING_OFFLINE
:
3544 ret
= slab_mem_going_offline_callback(arg
);
3547 case MEM_CANCEL_ONLINE
:
3548 slab_mem_offline_callback(arg
);
3551 case MEM_CANCEL_OFFLINE
:
3555 ret
= notifier_from_errno(ret
);
3561 #endif /* CONFIG_MEMORY_HOTPLUG */
3563 /********************************************************************
3564 * Basic setup of slabs
3565 *******************************************************************/
3568 * Used for early kmem_cache structures that were allocated using
3569 * the page allocator. Allocate them properly then fix up the pointers
3570 * that may be pointing to the wrong kmem_cache structure.
3573 static struct kmem_cache
* __init
bootstrap(struct kmem_cache
*static_cache
)
3576 struct kmem_cache
*s
= kmem_cache_zalloc(kmem_cache
, GFP_NOWAIT
);
3578 memcpy(s
, static_cache
, kmem_cache
->object_size
);
3581 * This runs very early, and only the boot processor is supposed to be
3582 * up. Even if it weren't true, IRQs are not up so we couldn't fire
3585 __flush_cpu_slab(s
, smp_processor_id());
3586 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3587 struct kmem_cache_node
*n
= get_node(s
, node
);
3591 list_for_each_entry(p
, &n
->partial
, lru
)
3594 #ifdef CONFIG_SLUB_DEBUG
3595 list_for_each_entry(p
, &n
->full
, lru
)
3600 list_add(&s
->list
, &slab_caches
);
3604 void __init
kmem_cache_init(void)
3606 static __initdata
struct kmem_cache boot_kmem_cache
,
3607 boot_kmem_cache_node
;
3609 if (debug_guardpage_minorder())
3612 kmem_cache_node
= &boot_kmem_cache_node
;
3613 kmem_cache
= &boot_kmem_cache
;
3615 create_boot_cache(kmem_cache_node
, "kmem_cache_node",
3616 sizeof(struct kmem_cache_node
), SLAB_HWCACHE_ALIGN
);
3618 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
3620 /* Able to allocate the per node structures */
3621 slab_state
= PARTIAL
;
3623 create_boot_cache(kmem_cache
, "kmem_cache",
3624 offsetof(struct kmem_cache
, node
) +
3625 nr_node_ids
* sizeof(struct kmem_cache_node
*),
3626 SLAB_HWCACHE_ALIGN
);
3628 kmem_cache
= bootstrap(&boot_kmem_cache
);
3631 * Allocate kmem_cache_node properly from the kmem_cache slab.
3632 * kmem_cache_node is separately allocated so no need to
3633 * update any list pointers.
3635 kmem_cache_node
= bootstrap(&boot_kmem_cache_node
);
3637 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3638 create_kmalloc_caches(0);
3641 register_cpu_notifier(&slab_notifier
);
3645 "SLUB: HWalign=%d, Order=%d-%d, MinObjects=%d,"
3646 " CPUs=%d, Nodes=%d\n",
3648 slub_min_order
, slub_max_order
, slub_min_objects
,
3649 nr_cpu_ids
, nr_node_ids
);
3652 void __init
kmem_cache_init_late(void)
3657 * Find a mergeable slab cache
3659 static int slab_unmergeable(struct kmem_cache
*s
)
3661 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3668 * We may have set a slab to be unmergeable during bootstrap.
3670 if (s
->refcount
< 0)
3676 static struct kmem_cache
*find_mergeable(struct mem_cgroup
*memcg
, size_t size
,
3677 size_t align
, unsigned long flags
, const char *name
,
3678 void (*ctor
)(void *))
3680 struct kmem_cache
*s
;
3682 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3688 size
= ALIGN(size
, sizeof(void *));
3689 align
= calculate_alignment(flags
, align
, size
);
3690 size
= ALIGN(size
, align
);
3691 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3693 list_for_each_entry(s
, &slab_caches
, list
) {
3694 if (slab_unmergeable(s
))
3700 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3703 * Check if alignment is compatible.
3704 * Courtesy of Adrian Drzewiecki
3706 if ((s
->size
& ~(align
- 1)) != s
->size
)
3709 if (s
->size
- size
>= sizeof(void *))
3712 if (!cache_match_memcg(s
, memcg
))
3721 __kmem_cache_alias(struct mem_cgroup
*memcg
, const char *name
, size_t size
,
3722 size_t align
, unsigned long flags
, void (*ctor
)(void *))
3724 struct kmem_cache
*s
;
3726 s
= find_mergeable(memcg
, size
, align
, flags
, name
, ctor
);
3730 * Adjust the object sizes so that we clear
3731 * the complete object on kzalloc.
3733 s
->object_size
= max(s
->object_size
, (int)size
);
3734 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3736 if (sysfs_slab_alias(s
, name
)) {
3745 int __kmem_cache_create(struct kmem_cache
*s
, unsigned long flags
)
3749 err
= kmem_cache_open(s
, flags
);
3753 /* Mutex is not taken during early boot */
3754 if (slab_state
<= UP
)
3757 memcg_propagate_slab_attrs(s
);
3758 mutex_unlock(&slab_mutex
);
3759 err
= sysfs_slab_add(s
);
3760 mutex_lock(&slab_mutex
);
3763 kmem_cache_close(s
);
3770 * Use the cpu notifier to insure that the cpu slabs are flushed when
3773 static int __cpuinit
slab_cpuup_callback(struct notifier_block
*nfb
,
3774 unsigned long action
, void *hcpu
)
3776 long cpu
= (long)hcpu
;
3777 struct kmem_cache
*s
;
3778 unsigned long flags
;
3781 case CPU_UP_CANCELED
:
3782 case CPU_UP_CANCELED_FROZEN
:
3784 case CPU_DEAD_FROZEN
:
3785 mutex_lock(&slab_mutex
);
3786 list_for_each_entry(s
, &slab_caches
, list
) {
3787 local_irq_save(flags
);
3788 __flush_cpu_slab(s
, cpu
);
3789 local_irq_restore(flags
);
3791 mutex_unlock(&slab_mutex
);
3799 static struct notifier_block __cpuinitdata slab_notifier
= {
3800 .notifier_call
= slab_cpuup_callback
3805 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, unsigned long caller
)
3807 struct kmem_cache
*s
;
3810 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
))
3811 return kmalloc_large(size
, gfpflags
);
3813 s
= kmalloc_slab(size
, gfpflags
);
3815 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3818 ret
= slab_alloc(s
, gfpflags
, caller
);
3820 /* Honor the call site pointer we received. */
3821 trace_kmalloc(caller
, ret
, size
, s
->size
, gfpflags
);
3827 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3828 int node
, unsigned long caller
)
3830 struct kmem_cache
*s
;
3833 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
)) {
3834 ret
= kmalloc_large_node(size
, gfpflags
, node
);
3836 trace_kmalloc_node(caller
, ret
,
3837 size
, PAGE_SIZE
<< get_order(size
),
3843 s
= kmalloc_slab(size
, gfpflags
);
3845 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3848 ret
= slab_alloc_node(s
, gfpflags
, node
, caller
);
3850 /* Honor the call site pointer we received. */
3851 trace_kmalloc_node(caller
, ret
, size
, s
->size
, gfpflags
, node
);
3858 static int count_inuse(struct page
*page
)
3863 static int count_total(struct page
*page
)
3865 return page
->objects
;
3869 #ifdef CONFIG_SLUB_DEBUG
3870 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3874 void *addr
= page_address(page
);
3876 if (!check_slab(s
, page
) ||
3877 !on_freelist(s
, page
, NULL
))
3880 /* Now we know that a valid freelist exists */
3881 bitmap_zero(map
, page
->objects
);
3883 get_map(s
, page
, map
);
3884 for_each_object(p
, s
, addr
, page
->objects
) {
3885 if (test_bit(slab_index(p
, s
, addr
), map
))
3886 if (!check_object(s
, page
, p
, SLUB_RED_INACTIVE
))
3890 for_each_object(p
, s
, addr
, page
->objects
)
3891 if (!test_bit(slab_index(p
, s
, addr
), map
))
3892 if (!check_object(s
, page
, p
, SLUB_RED_ACTIVE
))
3897 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
3901 validate_slab(s
, page
, map
);
3905 static int validate_slab_node(struct kmem_cache
*s
,
3906 struct kmem_cache_node
*n
, unsigned long *map
)
3908 unsigned long count
= 0;
3910 unsigned long flags
;
3912 spin_lock_irqsave(&n
->list_lock
, flags
);
3914 list_for_each_entry(page
, &n
->partial
, lru
) {
3915 validate_slab_slab(s
, page
, map
);
3918 if (count
!= n
->nr_partial
)
3919 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
3920 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
3922 if (!(s
->flags
& SLAB_STORE_USER
))
3925 list_for_each_entry(page
, &n
->full
, lru
) {
3926 validate_slab_slab(s
, page
, map
);
3929 if (count
!= atomic_long_read(&n
->nr_slabs
))
3930 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
3931 "counter=%ld\n", s
->name
, count
,
3932 atomic_long_read(&n
->nr_slabs
));
3935 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3939 static long validate_slab_cache(struct kmem_cache
*s
)
3942 unsigned long count
= 0;
3943 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
3944 sizeof(unsigned long), GFP_KERNEL
);
3950 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3951 struct kmem_cache_node
*n
= get_node(s
, node
);
3953 count
+= validate_slab_node(s
, n
, map
);
3959 * Generate lists of code addresses where slabcache objects are allocated
3964 unsigned long count
;
3971 DECLARE_BITMAP(cpus
, NR_CPUS
);
3977 unsigned long count
;
3978 struct location
*loc
;
3981 static void free_loc_track(struct loc_track
*t
)
3984 free_pages((unsigned long)t
->loc
,
3985 get_order(sizeof(struct location
) * t
->max
));
3988 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
3993 order
= get_order(sizeof(struct location
) * max
);
3995 l
= (void *)__get_free_pages(flags
, order
);
4000 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
4008 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
4009 const struct track
*track
)
4011 long start
, end
, pos
;
4013 unsigned long caddr
;
4014 unsigned long age
= jiffies
- track
->when
;
4020 pos
= start
+ (end
- start
+ 1) / 2;
4023 * There is nothing at "end". If we end up there
4024 * we need to add something to before end.
4029 caddr
= t
->loc
[pos
].addr
;
4030 if (track
->addr
== caddr
) {
4036 if (age
< l
->min_time
)
4038 if (age
> l
->max_time
)
4041 if (track
->pid
< l
->min_pid
)
4042 l
->min_pid
= track
->pid
;
4043 if (track
->pid
> l
->max_pid
)
4044 l
->max_pid
= track
->pid
;
4046 cpumask_set_cpu(track
->cpu
,
4047 to_cpumask(l
->cpus
));
4049 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4053 if (track
->addr
< caddr
)
4060 * Not found. Insert new tracking element.
4062 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
4068 (t
->count
- pos
) * sizeof(struct location
));
4071 l
->addr
= track
->addr
;
4075 l
->min_pid
= track
->pid
;
4076 l
->max_pid
= track
->pid
;
4077 cpumask_clear(to_cpumask(l
->cpus
));
4078 cpumask_set_cpu(track
->cpu
, to_cpumask(l
->cpus
));
4079 nodes_clear(l
->nodes
);
4080 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4084 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
4085 struct page
*page
, enum track_item alloc
,
4088 void *addr
= page_address(page
);
4091 bitmap_zero(map
, page
->objects
);
4092 get_map(s
, page
, map
);
4094 for_each_object(p
, s
, addr
, page
->objects
)
4095 if (!test_bit(slab_index(p
, s
, addr
), map
))
4096 add_location(t
, s
, get_track(s
, p
, alloc
));
4099 static int list_locations(struct kmem_cache
*s
, char *buf
,
4100 enum track_item alloc
)
4104 struct loc_track t
= { 0, 0, NULL
};
4106 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
4107 sizeof(unsigned long), GFP_KERNEL
);
4109 if (!map
|| !alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
4112 return sprintf(buf
, "Out of memory\n");
4114 /* Push back cpu slabs */
4117 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4118 struct kmem_cache_node
*n
= get_node(s
, node
);
4119 unsigned long flags
;
4122 if (!atomic_long_read(&n
->nr_slabs
))
4125 spin_lock_irqsave(&n
->list_lock
, flags
);
4126 list_for_each_entry(page
, &n
->partial
, lru
)
4127 process_slab(&t
, s
, page
, alloc
, map
);
4128 list_for_each_entry(page
, &n
->full
, lru
)
4129 process_slab(&t
, s
, page
, alloc
, map
);
4130 spin_unlock_irqrestore(&n
->list_lock
, flags
);
4133 for (i
= 0; i
< t
.count
; i
++) {
4134 struct location
*l
= &t
.loc
[i
];
4136 if (len
> PAGE_SIZE
- KSYM_SYMBOL_LEN
- 100)
4138 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
4141 len
+= sprintf(buf
+ len
, "%pS", (void *)l
->addr
);
4143 len
+= sprintf(buf
+ len
, "<not-available>");
4145 if (l
->sum_time
!= l
->min_time
) {
4146 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
4148 (long)div_u64(l
->sum_time
, l
->count
),
4151 len
+= sprintf(buf
+ len
, " age=%ld",
4154 if (l
->min_pid
!= l
->max_pid
)
4155 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
4156 l
->min_pid
, l
->max_pid
);
4158 len
+= sprintf(buf
+ len
, " pid=%ld",
4161 if (num_online_cpus() > 1 &&
4162 !cpumask_empty(to_cpumask(l
->cpus
)) &&
4163 len
< PAGE_SIZE
- 60) {
4164 len
+= sprintf(buf
+ len
, " cpus=");
4165 len
+= cpulist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
4166 to_cpumask(l
->cpus
));
4169 if (nr_online_nodes
> 1 && !nodes_empty(l
->nodes
) &&
4170 len
< PAGE_SIZE
- 60) {
4171 len
+= sprintf(buf
+ len
, " nodes=");
4172 len
+= nodelist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
4176 len
+= sprintf(buf
+ len
, "\n");
4182 len
+= sprintf(buf
, "No data\n");
4187 #ifdef SLUB_RESILIENCY_TEST
4188 static void resiliency_test(void)
4192 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 16 || KMALLOC_SHIFT_HIGH
< 10);
4194 printk(KERN_ERR
"SLUB resiliency testing\n");
4195 printk(KERN_ERR
"-----------------------\n");
4196 printk(KERN_ERR
"A. Corruption after allocation\n");
4198 p
= kzalloc(16, GFP_KERNEL
);
4200 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
4201 " 0x12->0x%p\n\n", p
+ 16);
4203 validate_slab_cache(kmalloc_caches
[4]);
4205 /* Hmmm... The next two are dangerous */
4206 p
= kzalloc(32, GFP_KERNEL
);
4207 p
[32 + sizeof(void *)] = 0x34;
4208 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
4209 " 0x34 -> -0x%p\n", p
);
4211 "If allocated object is overwritten then not detectable\n\n");
4213 validate_slab_cache(kmalloc_caches
[5]);
4214 p
= kzalloc(64, GFP_KERNEL
);
4215 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
4217 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
4220 "If allocated object is overwritten then not detectable\n\n");
4221 validate_slab_cache(kmalloc_caches
[6]);
4223 printk(KERN_ERR
"\nB. Corruption after free\n");
4224 p
= kzalloc(128, GFP_KERNEL
);
4227 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
4228 validate_slab_cache(kmalloc_caches
[7]);
4230 p
= kzalloc(256, GFP_KERNEL
);
4233 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
4235 validate_slab_cache(kmalloc_caches
[8]);
4237 p
= kzalloc(512, GFP_KERNEL
);
4240 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
4241 validate_slab_cache(kmalloc_caches
[9]);
4245 static void resiliency_test(void) {};
4250 enum slab_stat_type
{
4251 SL_ALL
, /* All slabs */
4252 SL_PARTIAL
, /* Only partially allocated slabs */
4253 SL_CPU
, /* Only slabs used for cpu caches */
4254 SL_OBJECTS
, /* Determine allocated objects not slabs */
4255 SL_TOTAL
/* Determine object capacity not slabs */
4258 #define SO_ALL (1 << SL_ALL)
4259 #define SO_PARTIAL (1 << SL_PARTIAL)
4260 #define SO_CPU (1 << SL_CPU)
4261 #define SO_OBJECTS (1 << SL_OBJECTS)
4262 #define SO_TOTAL (1 << SL_TOTAL)
4264 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
4265 char *buf
, unsigned long flags
)
4267 unsigned long total
= 0;
4270 unsigned long *nodes
;
4271 unsigned long *per_cpu
;
4273 nodes
= kzalloc(2 * sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
4276 per_cpu
= nodes
+ nr_node_ids
;
4278 if (flags
& SO_CPU
) {
4281 for_each_possible_cpu(cpu
) {
4282 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
4286 page
= ACCESS_ONCE(c
->page
);
4290 node
= page_to_nid(page
);
4291 if (flags
& SO_TOTAL
)
4293 else if (flags
& SO_OBJECTS
)
4301 page
= ACCESS_ONCE(c
->partial
);
4312 lock_memory_hotplug();
4313 #ifdef CONFIG_SLUB_DEBUG
4314 if (flags
& SO_ALL
) {
4315 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4316 struct kmem_cache_node
*n
= get_node(s
, node
);
4318 if (flags
& SO_TOTAL
)
4319 x
= atomic_long_read(&n
->total_objects
);
4320 else if (flags
& SO_OBJECTS
)
4321 x
= atomic_long_read(&n
->total_objects
) -
4322 count_partial(n
, count_free
);
4325 x
= atomic_long_read(&n
->nr_slabs
);
4332 if (flags
& SO_PARTIAL
) {
4333 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4334 struct kmem_cache_node
*n
= get_node(s
, node
);
4336 if (flags
& SO_TOTAL
)
4337 x
= count_partial(n
, count_total
);
4338 else if (flags
& SO_OBJECTS
)
4339 x
= count_partial(n
, count_inuse
);
4346 x
= sprintf(buf
, "%lu", total
);
4348 for_each_node_state(node
, N_NORMAL_MEMORY
)
4350 x
+= sprintf(buf
+ x
, " N%d=%lu",
4353 unlock_memory_hotplug();
4355 return x
+ sprintf(buf
+ x
, "\n");
4358 #ifdef CONFIG_SLUB_DEBUG
4359 static int any_slab_objects(struct kmem_cache
*s
)
4363 for_each_online_node(node
) {
4364 struct kmem_cache_node
*n
= get_node(s
, node
);
4369 if (atomic_long_read(&n
->total_objects
))
4376 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4377 #define to_slab(n) container_of(n, struct kmem_cache, kobj)
4379 struct slab_attribute
{
4380 struct attribute attr
;
4381 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
4382 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
4385 #define SLAB_ATTR_RO(_name) \
4386 static struct slab_attribute _name##_attr = \
4387 __ATTR(_name, 0400, _name##_show, NULL)
4389 #define SLAB_ATTR(_name) \
4390 static struct slab_attribute _name##_attr = \
4391 __ATTR(_name, 0600, _name##_show, _name##_store)
4393 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
4395 return sprintf(buf
, "%d\n", s
->size
);
4397 SLAB_ATTR_RO(slab_size
);
4399 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
4401 return sprintf(buf
, "%d\n", s
->align
);
4403 SLAB_ATTR_RO(align
);
4405 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
4407 return sprintf(buf
, "%d\n", s
->object_size
);
4409 SLAB_ATTR_RO(object_size
);
4411 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
4413 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
4415 SLAB_ATTR_RO(objs_per_slab
);
4417 static ssize_t
order_store(struct kmem_cache
*s
,
4418 const char *buf
, size_t length
)
4420 unsigned long order
;
4423 err
= strict_strtoul(buf
, 10, &order
);
4427 if (order
> slub_max_order
|| order
< slub_min_order
)
4430 calculate_sizes(s
, order
);
4434 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
4436 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
4440 static ssize_t
min_partial_show(struct kmem_cache
*s
, char *buf
)
4442 return sprintf(buf
, "%lu\n", s
->min_partial
);
4445 static ssize_t
min_partial_store(struct kmem_cache
*s
, const char *buf
,
4451 err
= strict_strtoul(buf
, 10, &min
);
4455 set_min_partial(s
, min
);
4458 SLAB_ATTR(min_partial
);
4460 static ssize_t
cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4462 return sprintf(buf
, "%u\n", s
->cpu_partial
);
4465 static ssize_t
cpu_partial_store(struct kmem_cache
*s
, const char *buf
,
4468 unsigned long objects
;
4471 err
= strict_strtoul(buf
, 10, &objects
);
4474 if (objects
&& !kmem_cache_has_cpu_partial(s
))
4477 s
->cpu_partial
= objects
;
4481 SLAB_ATTR(cpu_partial
);
4483 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
4487 return sprintf(buf
, "%pS\n", s
->ctor
);
4491 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
4493 return sprintf(buf
, "%d\n", s
->refcount
- 1);
4495 SLAB_ATTR_RO(aliases
);
4497 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
4499 return show_slab_objects(s
, buf
, SO_PARTIAL
);
4501 SLAB_ATTR_RO(partial
);
4503 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
4505 return show_slab_objects(s
, buf
, SO_CPU
);
4507 SLAB_ATTR_RO(cpu_slabs
);
4509 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
4511 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
4513 SLAB_ATTR_RO(objects
);
4515 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
4517 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
4519 SLAB_ATTR_RO(objects_partial
);
4521 static ssize_t
slabs_cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4528 for_each_online_cpu(cpu
) {
4529 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
)->partial
;
4532 pages
+= page
->pages
;
4533 objects
+= page
->pobjects
;
4537 len
= sprintf(buf
, "%d(%d)", objects
, pages
);
4540 for_each_online_cpu(cpu
) {
4541 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
) ->partial
;
4543 if (page
&& len
< PAGE_SIZE
- 20)
4544 len
+= sprintf(buf
+ len
, " C%d=%d(%d)", cpu
,
4545 page
->pobjects
, page
->pages
);
4548 return len
+ sprintf(buf
+ len
, "\n");
4550 SLAB_ATTR_RO(slabs_cpu_partial
);
4552 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
4554 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
4557 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
4558 const char *buf
, size_t length
)
4560 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
4562 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
4565 SLAB_ATTR(reclaim_account
);
4567 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
4569 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
4571 SLAB_ATTR_RO(hwcache_align
);
4573 #ifdef CONFIG_ZONE_DMA
4574 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
4576 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
4578 SLAB_ATTR_RO(cache_dma
);
4581 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
4583 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
4585 SLAB_ATTR_RO(destroy_by_rcu
);
4587 static ssize_t
reserved_show(struct kmem_cache
*s
, char *buf
)
4589 return sprintf(buf
, "%d\n", s
->reserved
);
4591 SLAB_ATTR_RO(reserved
);
4593 #ifdef CONFIG_SLUB_DEBUG
4594 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
4596 return show_slab_objects(s
, buf
, SO_ALL
);
4598 SLAB_ATTR_RO(slabs
);
4600 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
4602 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
4604 SLAB_ATTR_RO(total_objects
);
4606 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
4608 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
4611 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
4612 const char *buf
, size_t length
)
4614 s
->flags
&= ~SLAB_DEBUG_FREE
;
4615 if (buf
[0] == '1') {
4616 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4617 s
->flags
|= SLAB_DEBUG_FREE
;
4621 SLAB_ATTR(sanity_checks
);
4623 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
4625 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
4628 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
4631 s
->flags
&= ~SLAB_TRACE
;
4632 if (buf
[0] == '1') {
4633 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4634 s
->flags
|= SLAB_TRACE
;
4640 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
4642 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
4645 static ssize_t
red_zone_store(struct kmem_cache
*s
,
4646 const char *buf
, size_t length
)
4648 if (any_slab_objects(s
))
4651 s
->flags
&= ~SLAB_RED_ZONE
;
4652 if (buf
[0] == '1') {
4653 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4654 s
->flags
|= SLAB_RED_ZONE
;
4656 calculate_sizes(s
, -1);
4659 SLAB_ATTR(red_zone
);
4661 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
4663 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
4666 static ssize_t
poison_store(struct kmem_cache
*s
,
4667 const char *buf
, size_t length
)
4669 if (any_slab_objects(s
))
4672 s
->flags
&= ~SLAB_POISON
;
4673 if (buf
[0] == '1') {
4674 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4675 s
->flags
|= SLAB_POISON
;
4677 calculate_sizes(s
, -1);
4682 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4684 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4687 static ssize_t
store_user_store(struct kmem_cache
*s
,
4688 const char *buf
, size_t length
)
4690 if (any_slab_objects(s
))
4693 s
->flags
&= ~SLAB_STORE_USER
;
4694 if (buf
[0] == '1') {
4695 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4696 s
->flags
|= SLAB_STORE_USER
;
4698 calculate_sizes(s
, -1);
4701 SLAB_ATTR(store_user
);
4703 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4708 static ssize_t
validate_store(struct kmem_cache
*s
,
4709 const char *buf
, size_t length
)
4713 if (buf
[0] == '1') {
4714 ret
= validate_slab_cache(s
);
4720 SLAB_ATTR(validate
);
4722 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4724 if (!(s
->flags
& SLAB_STORE_USER
))
4726 return list_locations(s
, buf
, TRACK_ALLOC
);
4728 SLAB_ATTR_RO(alloc_calls
);
4730 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4732 if (!(s
->flags
& SLAB_STORE_USER
))
4734 return list_locations(s
, buf
, TRACK_FREE
);
4736 SLAB_ATTR_RO(free_calls
);
4737 #endif /* CONFIG_SLUB_DEBUG */
4739 #ifdef CONFIG_FAILSLAB
4740 static ssize_t
failslab_show(struct kmem_cache
*s
, char *buf
)
4742 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_FAILSLAB
));
4745 static ssize_t
failslab_store(struct kmem_cache
*s
, const char *buf
,
4748 s
->flags
&= ~SLAB_FAILSLAB
;
4750 s
->flags
|= SLAB_FAILSLAB
;
4753 SLAB_ATTR(failslab
);
4756 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4761 static ssize_t
shrink_store(struct kmem_cache
*s
,
4762 const char *buf
, size_t length
)
4764 if (buf
[0] == '1') {
4765 int rc
= kmem_cache_shrink(s
);
4776 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4778 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4781 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4782 const char *buf
, size_t length
)
4784 unsigned long ratio
;
4787 err
= strict_strtoul(buf
, 10, &ratio
);
4792 s
->remote_node_defrag_ratio
= ratio
* 10;
4796 SLAB_ATTR(remote_node_defrag_ratio
);
4799 #ifdef CONFIG_SLUB_STATS
4800 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4802 unsigned long sum
= 0;
4805 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4810 for_each_online_cpu(cpu
) {
4811 unsigned x
= per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
];
4817 len
= sprintf(buf
, "%lu", sum
);
4820 for_each_online_cpu(cpu
) {
4821 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4822 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4826 return len
+ sprintf(buf
+ len
, "\n");
4829 static void clear_stat(struct kmem_cache
*s
, enum stat_item si
)
4833 for_each_online_cpu(cpu
)
4834 per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
] = 0;
4837 #define STAT_ATTR(si, text) \
4838 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4840 return show_stat(s, buf, si); \
4842 static ssize_t text##_store(struct kmem_cache *s, \
4843 const char *buf, size_t length) \
4845 if (buf[0] != '0') \
4847 clear_stat(s, si); \
4852 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4853 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4854 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4855 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4856 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4857 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4858 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4859 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4860 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4861 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4862 STAT_ATTR(ALLOC_NODE_MISMATCH
, alloc_node_mismatch
);
4863 STAT_ATTR(FREE_SLAB
, free_slab
);
4864 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4865 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4866 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4867 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4868 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4869 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4870 STAT_ATTR(DEACTIVATE_BYPASS
, deactivate_bypass
);
4871 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4872 STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL
, cmpxchg_double_cpu_fail
);
4873 STAT_ATTR(CMPXCHG_DOUBLE_FAIL
, cmpxchg_double_fail
);
4874 STAT_ATTR(CPU_PARTIAL_ALLOC
, cpu_partial_alloc
);
4875 STAT_ATTR(CPU_PARTIAL_FREE
, cpu_partial_free
);
4876 STAT_ATTR(CPU_PARTIAL_NODE
, cpu_partial_node
);
4877 STAT_ATTR(CPU_PARTIAL_DRAIN
, cpu_partial_drain
);
4880 static struct attribute
*slab_attrs
[] = {
4881 &slab_size_attr
.attr
,
4882 &object_size_attr
.attr
,
4883 &objs_per_slab_attr
.attr
,
4885 &min_partial_attr
.attr
,
4886 &cpu_partial_attr
.attr
,
4888 &objects_partial_attr
.attr
,
4890 &cpu_slabs_attr
.attr
,
4894 &hwcache_align_attr
.attr
,
4895 &reclaim_account_attr
.attr
,
4896 &destroy_by_rcu_attr
.attr
,
4898 &reserved_attr
.attr
,
4899 &slabs_cpu_partial_attr
.attr
,
4900 #ifdef CONFIG_SLUB_DEBUG
4901 &total_objects_attr
.attr
,
4903 &sanity_checks_attr
.attr
,
4905 &red_zone_attr
.attr
,
4907 &store_user_attr
.attr
,
4908 &validate_attr
.attr
,
4909 &alloc_calls_attr
.attr
,
4910 &free_calls_attr
.attr
,
4912 #ifdef CONFIG_ZONE_DMA
4913 &cache_dma_attr
.attr
,
4916 &remote_node_defrag_ratio_attr
.attr
,
4918 #ifdef CONFIG_SLUB_STATS
4919 &alloc_fastpath_attr
.attr
,
4920 &alloc_slowpath_attr
.attr
,
4921 &free_fastpath_attr
.attr
,
4922 &free_slowpath_attr
.attr
,
4923 &free_frozen_attr
.attr
,
4924 &free_add_partial_attr
.attr
,
4925 &free_remove_partial_attr
.attr
,
4926 &alloc_from_partial_attr
.attr
,
4927 &alloc_slab_attr
.attr
,
4928 &alloc_refill_attr
.attr
,
4929 &alloc_node_mismatch_attr
.attr
,
4930 &free_slab_attr
.attr
,
4931 &cpuslab_flush_attr
.attr
,
4932 &deactivate_full_attr
.attr
,
4933 &deactivate_empty_attr
.attr
,
4934 &deactivate_to_head_attr
.attr
,
4935 &deactivate_to_tail_attr
.attr
,
4936 &deactivate_remote_frees_attr
.attr
,
4937 &deactivate_bypass_attr
.attr
,
4938 &order_fallback_attr
.attr
,
4939 &cmpxchg_double_fail_attr
.attr
,
4940 &cmpxchg_double_cpu_fail_attr
.attr
,
4941 &cpu_partial_alloc_attr
.attr
,
4942 &cpu_partial_free_attr
.attr
,
4943 &cpu_partial_node_attr
.attr
,
4944 &cpu_partial_drain_attr
.attr
,
4946 #ifdef CONFIG_FAILSLAB
4947 &failslab_attr
.attr
,
4953 static struct attribute_group slab_attr_group
= {
4954 .attrs
= slab_attrs
,
4957 static ssize_t
slab_attr_show(struct kobject
*kobj
,
4958 struct attribute
*attr
,
4961 struct slab_attribute
*attribute
;
4962 struct kmem_cache
*s
;
4965 attribute
= to_slab_attr(attr
);
4968 if (!attribute
->show
)
4971 err
= attribute
->show(s
, buf
);
4976 static ssize_t
slab_attr_store(struct kobject
*kobj
,
4977 struct attribute
*attr
,
4978 const char *buf
, size_t len
)
4980 struct slab_attribute
*attribute
;
4981 struct kmem_cache
*s
;
4984 attribute
= to_slab_attr(attr
);
4987 if (!attribute
->store
)
4990 err
= attribute
->store(s
, buf
, len
);
4991 #ifdef CONFIG_MEMCG_KMEM
4992 if (slab_state
>= FULL
&& err
>= 0 && is_root_cache(s
)) {
4995 mutex_lock(&slab_mutex
);
4996 if (s
->max_attr_size
< len
)
4997 s
->max_attr_size
= len
;
5000 * This is a best effort propagation, so this function's return
5001 * value will be determined by the parent cache only. This is
5002 * basically because not all attributes will have a well
5003 * defined semantics for rollbacks - most of the actions will
5004 * have permanent effects.
5006 * Returning the error value of any of the children that fail
5007 * is not 100 % defined, in the sense that users seeing the
5008 * error code won't be able to know anything about the state of
5011 * Only returning the error code for the parent cache at least
5012 * has well defined semantics. The cache being written to
5013 * directly either failed or succeeded, in which case we loop
5014 * through the descendants with best-effort propagation.
5016 for_each_memcg_cache_index(i
) {
5017 struct kmem_cache
*c
= cache_from_memcg(s
, i
);
5019 attribute
->store(c
, buf
, len
);
5021 mutex_unlock(&slab_mutex
);
5027 static void memcg_propagate_slab_attrs(struct kmem_cache
*s
)
5029 #ifdef CONFIG_MEMCG_KMEM
5031 char *buffer
= NULL
;
5033 if (!is_root_cache(s
))
5037 * This mean this cache had no attribute written. Therefore, no point
5038 * in copying default values around
5040 if (!s
->max_attr_size
)
5043 for (i
= 0; i
< ARRAY_SIZE(slab_attrs
); i
++) {
5046 struct slab_attribute
*attr
= to_slab_attr(slab_attrs
[i
]);
5048 if (!attr
|| !attr
->store
|| !attr
->show
)
5052 * It is really bad that we have to allocate here, so we will
5053 * do it only as a fallback. If we actually allocate, though,
5054 * we can just use the allocated buffer until the end.
5056 * Most of the slub attributes will tend to be very small in
5057 * size, but sysfs allows buffers up to a page, so they can
5058 * theoretically happen.
5062 else if (s
->max_attr_size
< ARRAY_SIZE(mbuf
))
5065 buffer
= (char *) get_zeroed_page(GFP_KERNEL
);
5066 if (WARN_ON(!buffer
))
5071 attr
->show(s
->memcg_params
->root_cache
, buf
);
5072 attr
->store(s
, buf
, strlen(buf
));
5076 free_page((unsigned long)buffer
);
5080 static const struct sysfs_ops slab_sysfs_ops
= {
5081 .show
= slab_attr_show
,
5082 .store
= slab_attr_store
,
5085 static struct kobj_type slab_ktype
= {
5086 .sysfs_ops
= &slab_sysfs_ops
,
5089 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
5091 struct kobj_type
*ktype
= get_ktype(kobj
);
5093 if (ktype
== &slab_ktype
)
5098 static const struct kset_uevent_ops slab_uevent_ops
= {
5099 .filter
= uevent_filter
,
5102 static struct kset
*slab_kset
;
5104 #define ID_STR_LENGTH 64
5106 /* Create a unique string id for a slab cache:
5108 * Format :[flags-]size
5110 static char *create_unique_id(struct kmem_cache
*s
)
5112 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
5119 * First flags affecting slabcache operations. We will only
5120 * get here for aliasable slabs so we do not need to support
5121 * too many flags. The flags here must cover all flags that
5122 * are matched during merging to guarantee that the id is
5125 if (s
->flags
& SLAB_CACHE_DMA
)
5127 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
5129 if (s
->flags
& SLAB_DEBUG_FREE
)
5131 if (!(s
->flags
& SLAB_NOTRACK
))
5135 p
+= sprintf(p
, "%07d", s
->size
);
5137 #ifdef CONFIG_MEMCG_KMEM
5138 if (!is_root_cache(s
))
5139 p
+= sprintf(p
, "-%08d", memcg_cache_id(s
->memcg_params
->memcg
));
5142 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
5146 static int sysfs_slab_add(struct kmem_cache
*s
)
5150 int unmergeable
= slab_unmergeable(s
);
5154 * Slabcache can never be merged so we can use the name proper.
5155 * This is typically the case for debug situations. In that
5156 * case we can catch duplicate names easily.
5158 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
5162 * Create a unique name for the slab as a target
5165 name
= create_unique_id(s
);
5168 s
->kobj
.kset
= slab_kset
;
5169 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, name
);
5171 kobject_put(&s
->kobj
);
5175 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
5177 kobject_del(&s
->kobj
);
5178 kobject_put(&s
->kobj
);
5181 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
5183 /* Setup first alias */
5184 sysfs_slab_alias(s
, s
->name
);
5190 static void sysfs_slab_remove(struct kmem_cache
*s
)
5192 if (slab_state
< FULL
)
5194 * Sysfs has not been setup yet so no need to remove the
5199 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
5200 kobject_del(&s
->kobj
);
5201 kobject_put(&s
->kobj
);
5205 * Need to buffer aliases during bootup until sysfs becomes
5206 * available lest we lose that information.
5208 struct saved_alias
{
5209 struct kmem_cache
*s
;
5211 struct saved_alias
*next
;
5214 static struct saved_alias
*alias_list
;
5216 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
5218 struct saved_alias
*al
;
5220 if (slab_state
== FULL
) {
5222 * If we have a leftover link then remove it.
5224 sysfs_remove_link(&slab_kset
->kobj
, name
);
5225 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
5228 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
5234 al
->next
= alias_list
;
5239 static int __init
slab_sysfs_init(void)
5241 struct kmem_cache
*s
;
5244 mutex_lock(&slab_mutex
);
5246 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
5248 mutex_unlock(&slab_mutex
);
5249 printk(KERN_ERR
"Cannot register slab subsystem.\n");
5255 list_for_each_entry(s
, &slab_caches
, list
) {
5256 err
= sysfs_slab_add(s
);
5258 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
5259 " to sysfs\n", s
->name
);
5262 while (alias_list
) {
5263 struct saved_alias
*al
= alias_list
;
5265 alias_list
= alias_list
->next
;
5266 err
= sysfs_slab_alias(al
->s
, al
->name
);
5268 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
5269 " %s to sysfs\n", al
->name
);
5273 mutex_unlock(&slab_mutex
);
5278 __initcall(slab_sysfs_init
);
5279 #endif /* CONFIG_SYSFS */
5282 * The /proc/slabinfo ABI
5284 #ifdef CONFIG_SLABINFO
5285 void get_slabinfo(struct kmem_cache
*s
, struct slabinfo
*sinfo
)
5287 unsigned long nr_slabs
= 0;
5288 unsigned long nr_objs
= 0;
5289 unsigned long nr_free
= 0;
5292 for_each_online_node(node
) {
5293 struct kmem_cache_node
*n
= get_node(s
, node
);
5298 nr_slabs
+= node_nr_slabs(n
);
5299 nr_objs
+= node_nr_objs(n
);
5300 nr_free
+= count_partial(n
, count_free
);
5303 sinfo
->active_objs
= nr_objs
- nr_free
;
5304 sinfo
->num_objs
= nr_objs
;
5305 sinfo
->active_slabs
= nr_slabs
;
5306 sinfo
->num_slabs
= nr_slabs
;
5307 sinfo
->objects_per_slab
= oo_objects(s
->oo
);
5308 sinfo
->cache_order
= oo_order(s
->oo
);
5311 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*s
)
5315 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
5316 size_t count
, loff_t
*ppos
)
5320 #endif /* CONFIG_SLABINFO */