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>
35 #include <trace/events/kmem.h>
41 * 1. slab_mutex (Global Mutex)
43 * 3. slab_lock(page) (Only on some arches and for debugging)
47 * The role of the slab_mutex is to protect the list of all the slabs
48 * and to synchronize major metadata changes to slab cache structures.
50 * The slab_lock is only used for debugging and on arches that do not
51 * have the ability to do a cmpxchg_double. It only protects the second
52 * double word in the page struct. Meaning
53 * A. page->freelist -> List of object free in a page
54 * B. page->counters -> Counters of objects
55 * C. page->frozen -> frozen state
57 * If a slab is frozen then it is exempt from list management. It is not
58 * on any list. The processor that froze the slab is the one who can
59 * perform list operations on the page. Other processors may put objects
60 * onto the freelist but the processor that froze the slab is the only
61 * one that can retrieve the objects from the page's freelist.
63 * The list_lock protects the partial and full list on each node and
64 * the partial slab counter. If taken then no new slabs may be added or
65 * removed from the lists nor make the number of partial slabs be modified.
66 * (Note that the total number of slabs is an atomic value that may be
67 * modified without taking the list lock).
69 * The list_lock is a centralized lock and thus we avoid taking it as
70 * much as possible. As long as SLUB does not have to handle partial
71 * slabs, operations can continue without any centralized lock. F.e.
72 * allocating a long series of objects that fill up slabs does not require
74 * Interrupts are disabled during allocation and deallocation in order to
75 * make the slab allocator safe to use in the context of an irq. In addition
76 * interrupts are disabled to ensure that the processor does not change
77 * while handling per_cpu slabs, due to kernel preemption.
79 * SLUB assigns one slab for allocation to each processor.
80 * Allocations only occur from these slabs called cpu slabs.
82 * Slabs with free elements are kept on a partial list and during regular
83 * operations no list for full slabs is used. If an object in a full slab is
84 * freed then the slab will show up again on the partial lists.
85 * We track full slabs for debugging purposes though because otherwise we
86 * cannot scan all objects.
88 * Slabs are freed when they become empty. Teardown and setup is
89 * minimal so we rely on the page allocators per cpu caches for
90 * fast frees and allocs.
92 * Overloading of page flags that are otherwise used for LRU management.
94 * PageActive The slab is frozen and exempt from list processing.
95 * This means that the slab is dedicated to a purpose
96 * such as satisfying allocations for a specific
97 * processor. Objects may be freed in the slab while
98 * it is frozen but slab_free will then skip the usual
99 * list operations. It is up to the processor holding
100 * the slab to integrate the slab into the slab lists
101 * when the slab is no longer needed.
103 * One use of this flag is to mark slabs that are
104 * used for allocations. Then such a slab becomes a cpu
105 * slab. The cpu slab may be equipped with an additional
106 * freelist that allows lockless access to
107 * free objects in addition to the regular freelist
108 * that requires the slab lock.
110 * PageError Slab requires special handling due to debug
111 * options set. This moves slab handling out of
112 * the fast path and disables lockless freelists.
115 static inline int kmem_cache_debug(struct kmem_cache
*s
)
117 #ifdef CONFIG_SLUB_DEBUG
118 return unlikely(s
->flags
& SLAB_DEBUG_FLAGS
);
125 * Issues still to be resolved:
127 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
129 * - Variable sizing of the per node arrays
132 /* Enable to test recovery from slab corruption on boot */
133 #undef SLUB_RESILIENCY_TEST
135 /* Enable to log cmpxchg failures */
136 #undef SLUB_DEBUG_CMPXCHG
139 * Mininum number of partial slabs. These will be left on the partial
140 * lists even if they are empty. kmem_cache_shrink may reclaim them.
142 #define MIN_PARTIAL 5
145 * Maximum number of desirable partial slabs.
146 * The existence of more partial slabs makes kmem_cache_shrink
147 * sort the partial list by the number of objects in the.
149 #define MAX_PARTIAL 10
151 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
152 SLAB_POISON | SLAB_STORE_USER)
155 * Debugging flags that require metadata to be stored in the slab. These get
156 * disabled when slub_debug=O is used and a cache's min order increases with
159 #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
162 * Set of flags that will prevent slab merging
164 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
165 SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
168 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
169 SLAB_CACHE_DMA | SLAB_NOTRACK)
172 #define OO_MASK ((1 << OO_SHIFT) - 1)
173 #define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */
175 /* Internal SLUB flags */
176 #define __OBJECT_POISON 0x80000000UL /* Poison object */
177 #define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */
180 static struct notifier_block slab_notifier
;
184 * Tracking user of a slab.
186 #define TRACK_ADDRS_COUNT 16
188 unsigned long addr
; /* Called from address */
189 #ifdef CONFIG_STACKTRACE
190 unsigned long addrs
[TRACK_ADDRS_COUNT
]; /* Called from address */
192 int cpu
; /* Was running on cpu */
193 int pid
; /* Pid context */
194 unsigned long when
; /* When did the operation occur */
197 enum track_item
{ TRACK_ALLOC
, TRACK_FREE
};
200 static int sysfs_slab_add(struct kmem_cache
*);
201 static int sysfs_slab_alias(struct kmem_cache
*, const char *);
202 static void sysfs_slab_remove(struct kmem_cache
*);
205 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
206 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
208 static inline void sysfs_slab_remove(struct kmem_cache
*s
) { }
212 static inline void stat(const struct kmem_cache
*s
, enum stat_item si
)
214 #ifdef CONFIG_SLUB_STATS
215 __this_cpu_inc(s
->cpu_slab
->stat
[si
]);
219 /********************************************************************
220 * Core slab cache functions
221 *******************************************************************/
223 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
225 return s
->node
[node
];
228 /* Verify that a pointer has an address that is valid within a slab page */
229 static inline int check_valid_pointer(struct kmem_cache
*s
,
230 struct page
*page
, const void *object
)
237 base
= page_address(page
);
238 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
239 (object
- base
) % s
->size
) {
246 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
248 return *(void **)(object
+ s
->offset
);
251 static void prefetch_freepointer(const struct kmem_cache
*s
, void *object
)
253 prefetch(object
+ s
->offset
);
256 static inline void *get_freepointer_safe(struct kmem_cache
*s
, void *object
)
260 #ifdef CONFIG_DEBUG_PAGEALLOC
261 probe_kernel_read(&p
, (void **)(object
+ s
->offset
), sizeof(p
));
263 p
= get_freepointer(s
, object
);
268 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
270 *(void **)(object
+ s
->offset
) = fp
;
273 /* Loop over all objects in a slab */
274 #define for_each_object(__p, __s, __addr, __objects) \
275 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
278 /* Determine object index from a given position */
279 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
281 return (p
- addr
) / s
->size
;
284 static inline size_t slab_ksize(const struct kmem_cache
*s
)
286 #ifdef CONFIG_SLUB_DEBUG
288 * Debugging requires use of the padding between object
289 * and whatever may come after it.
291 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
292 return s
->object_size
;
296 * If we have the need to store the freelist pointer
297 * back there or track user information then we can
298 * only use the space before that information.
300 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
303 * Else we can use all the padding etc for the allocation
308 static inline int order_objects(int order
, unsigned long size
, int reserved
)
310 return ((PAGE_SIZE
<< order
) - reserved
) / size
;
313 static inline struct kmem_cache_order_objects
oo_make(int order
,
314 unsigned long size
, int reserved
)
316 struct kmem_cache_order_objects x
= {
317 (order
<< OO_SHIFT
) + order_objects(order
, size
, reserved
)
323 static inline int oo_order(struct kmem_cache_order_objects x
)
325 return x
.x
>> OO_SHIFT
;
328 static inline int oo_objects(struct kmem_cache_order_objects x
)
330 return x
.x
& OO_MASK
;
334 * Per slab locking using the pagelock
336 static __always_inline
void slab_lock(struct page
*page
)
338 bit_spin_lock(PG_locked
, &page
->flags
);
341 static __always_inline
void slab_unlock(struct page
*page
)
343 __bit_spin_unlock(PG_locked
, &page
->flags
);
346 /* Interrupts must be disabled (for the fallback code to work right) */
347 static inline bool __cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
348 void *freelist_old
, unsigned long counters_old
,
349 void *freelist_new
, unsigned long counters_new
,
352 VM_BUG_ON(!irqs_disabled());
353 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
354 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
355 if (s
->flags
& __CMPXCHG_DOUBLE
) {
356 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
357 freelist_old
, counters_old
,
358 freelist_new
, counters_new
))
364 if (page
->freelist
== freelist_old
&& page
->counters
== counters_old
) {
365 page
->freelist
= freelist_new
;
366 page
->counters
= counters_new
;
374 stat(s
, CMPXCHG_DOUBLE_FAIL
);
376 #ifdef SLUB_DEBUG_CMPXCHG
377 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
383 static inline bool cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
384 void *freelist_old
, unsigned long counters_old
,
385 void *freelist_new
, unsigned long counters_new
,
388 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
389 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
390 if (s
->flags
& __CMPXCHG_DOUBLE
) {
391 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
392 freelist_old
, counters_old
,
393 freelist_new
, counters_new
))
400 local_irq_save(flags
);
402 if (page
->freelist
== freelist_old
&& page
->counters
== counters_old
) {
403 page
->freelist
= freelist_new
;
404 page
->counters
= counters_new
;
406 local_irq_restore(flags
);
410 local_irq_restore(flags
);
414 stat(s
, CMPXCHG_DOUBLE_FAIL
);
416 #ifdef SLUB_DEBUG_CMPXCHG
417 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
423 #ifdef CONFIG_SLUB_DEBUG
425 * Determine a map of object in use on a page.
427 * Node listlock must be held to guarantee that the page does
428 * not vanish from under us.
430 static void get_map(struct kmem_cache
*s
, struct page
*page
, unsigned long *map
)
433 void *addr
= page_address(page
);
435 for (p
= page
->freelist
; p
; p
= get_freepointer(s
, p
))
436 set_bit(slab_index(p
, s
, addr
), map
);
442 #ifdef CONFIG_SLUB_DEBUG_ON
443 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
445 static int slub_debug
;
448 static char *slub_debug_slabs
;
449 static int disable_higher_order_debug
;
454 static void print_section(char *text
, u8
*addr
, unsigned int length
)
456 print_hex_dump(KERN_ERR
, text
, DUMP_PREFIX_ADDRESS
, 16, 1, addr
,
460 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
461 enum track_item alloc
)
466 p
= object
+ s
->offset
+ sizeof(void *);
468 p
= object
+ s
->inuse
;
473 static void set_track(struct kmem_cache
*s
, void *object
,
474 enum track_item alloc
, unsigned long addr
)
476 struct track
*p
= get_track(s
, object
, alloc
);
479 #ifdef CONFIG_STACKTRACE
480 struct stack_trace trace
;
483 trace
.nr_entries
= 0;
484 trace
.max_entries
= TRACK_ADDRS_COUNT
;
485 trace
.entries
= p
->addrs
;
487 save_stack_trace(&trace
);
489 /* See rant in lockdep.c */
490 if (trace
.nr_entries
!= 0 &&
491 trace
.entries
[trace
.nr_entries
- 1] == ULONG_MAX
)
494 for (i
= trace
.nr_entries
; i
< TRACK_ADDRS_COUNT
; i
++)
498 p
->cpu
= smp_processor_id();
499 p
->pid
= current
->pid
;
502 memset(p
, 0, sizeof(struct track
));
505 static void init_tracking(struct kmem_cache
*s
, void *object
)
507 if (!(s
->flags
& SLAB_STORE_USER
))
510 set_track(s
, object
, TRACK_FREE
, 0UL);
511 set_track(s
, object
, TRACK_ALLOC
, 0UL);
514 static void print_track(const char *s
, struct track
*t
)
519 printk(KERN_ERR
"INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
520 s
, (void *)t
->addr
, jiffies
- t
->when
, t
->cpu
, t
->pid
);
521 #ifdef CONFIG_STACKTRACE
524 for (i
= 0; i
< TRACK_ADDRS_COUNT
; i
++)
526 printk(KERN_ERR
"\t%pS\n", (void *)t
->addrs
[i
]);
533 static void print_tracking(struct kmem_cache
*s
, void *object
)
535 if (!(s
->flags
& SLAB_STORE_USER
))
538 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
539 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
542 static void print_page_info(struct page
*page
)
544 printk(KERN_ERR
"INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
545 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
549 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
555 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
557 printk(KERN_ERR
"========================================"
558 "=====================================\n");
559 printk(KERN_ERR
"BUG %s (%s): %s\n", s
->name
, print_tainted(), buf
);
560 printk(KERN_ERR
"----------------------------------------"
561 "-------------------------------------\n\n");
563 add_taint(TAINT_BAD_PAGE
);
566 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
572 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
574 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
577 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
579 unsigned int off
; /* Offset of last byte */
580 u8
*addr
= page_address(page
);
582 print_tracking(s
, p
);
584 print_page_info(page
);
586 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
587 p
, p
- addr
, get_freepointer(s
, p
));
590 print_section("Bytes b4 ", p
- 16, 16);
592 print_section("Object ", p
, min_t(unsigned long, s
->object_size
,
594 if (s
->flags
& SLAB_RED_ZONE
)
595 print_section("Redzone ", p
+ s
->object_size
,
596 s
->inuse
- s
->object_size
);
599 off
= s
->offset
+ sizeof(void *);
603 if (s
->flags
& SLAB_STORE_USER
)
604 off
+= 2 * sizeof(struct track
);
607 /* Beginning of the filler is the free pointer */
608 print_section("Padding ", p
+ off
, s
->size
- off
);
613 static void object_err(struct kmem_cache
*s
, struct page
*page
,
614 u8
*object
, char *reason
)
616 slab_bug(s
, "%s", reason
);
617 print_trailer(s
, page
, object
);
620 static void slab_err(struct kmem_cache
*s
, struct page
*page
, const char *fmt
, ...)
626 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
628 slab_bug(s
, "%s", buf
);
629 print_page_info(page
);
633 static void init_object(struct kmem_cache
*s
, void *object
, u8 val
)
637 if (s
->flags
& __OBJECT_POISON
) {
638 memset(p
, POISON_FREE
, s
->object_size
- 1);
639 p
[s
->object_size
- 1] = POISON_END
;
642 if (s
->flags
& SLAB_RED_ZONE
)
643 memset(p
+ s
->object_size
, val
, s
->inuse
- s
->object_size
);
646 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
647 void *from
, void *to
)
649 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
650 memset(from
, data
, to
- from
);
653 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
654 u8
*object
, char *what
,
655 u8
*start
, unsigned int value
, unsigned int bytes
)
660 fault
= memchr_inv(start
, value
, bytes
);
665 while (end
> fault
&& end
[-1] == value
)
668 slab_bug(s
, "%s overwritten", what
);
669 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
670 fault
, end
- 1, fault
[0], value
);
671 print_trailer(s
, page
, object
);
673 restore_bytes(s
, what
, value
, fault
, end
);
681 * Bytes of the object to be managed.
682 * If the freepointer may overlay the object then the free
683 * pointer is the first word of the object.
685 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
688 * object + s->object_size
689 * Padding to reach word boundary. This is also used for Redzoning.
690 * Padding is extended by another word if Redzoning is enabled and
691 * object_size == inuse.
693 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
694 * 0xcc (RED_ACTIVE) for objects in use.
697 * Meta data starts here.
699 * A. Free pointer (if we cannot overwrite object on free)
700 * B. Tracking data for SLAB_STORE_USER
701 * C. Padding to reach required alignment boundary or at mininum
702 * one word if debugging is on to be able to detect writes
703 * before the word boundary.
705 * Padding is done using 0x5a (POISON_INUSE)
708 * Nothing is used beyond s->size.
710 * If slabcaches are merged then the object_size and inuse boundaries are mostly
711 * ignored. And therefore no slab options that rely on these boundaries
712 * may be used with merged slabcaches.
715 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
717 unsigned long off
= s
->inuse
; /* The end of info */
720 /* Freepointer is placed after the object. */
721 off
+= sizeof(void *);
723 if (s
->flags
& SLAB_STORE_USER
)
724 /* We also have user information there */
725 off
+= 2 * sizeof(struct track
);
730 return check_bytes_and_report(s
, page
, p
, "Object padding",
731 p
+ off
, POISON_INUSE
, s
->size
- off
);
734 /* Check the pad bytes at the end of a slab page */
735 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
743 if (!(s
->flags
& SLAB_POISON
))
746 start
= page_address(page
);
747 length
= (PAGE_SIZE
<< compound_order(page
)) - s
->reserved
;
748 end
= start
+ length
;
749 remainder
= length
% s
->size
;
753 fault
= memchr_inv(end
- remainder
, POISON_INUSE
, remainder
);
756 while (end
> fault
&& end
[-1] == POISON_INUSE
)
759 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
760 print_section("Padding ", end
- remainder
, remainder
);
762 restore_bytes(s
, "slab padding", POISON_INUSE
, end
- remainder
, end
);
766 static int check_object(struct kmem_cache
*s
, struct page
*page
,
767 void *object
, u8 val
)
770 u8
*endobject
= object
+ s
->object_size
;
772 if (s
->flags
& SLAB_RED_ZONE
) {
773 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
774 endobject
, val
, s
->inuse
- s
->object_size
))
777 if ((s
->flags
& SLAB_POISON
) && s
->object_size
< s
->inuse
) {
778 check_bytes_and_report(s
, page
, p
, "Alignment padding",
779 endobject
, POISON_INUSE
, s
->inuse
- s
->object_size
);
783 if (s
->flags
& SLAB_POISON
) {
784 if (val
!= SLUB_RED_ACTIVE
&& (s
->flags
& __OBJECT_POISON
) &&
785 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
786 POISON_FREE
, s
->object_size
- 1) ||
787 !check_bytes_and_report(s
, page
, p
, "Poison",
788 p
+ s
->object_size
- 1, POISON_END
, 1)))
791 * check_pad_bytes cleans up on its own.
793 check_pad_bytes(s
, page
, p
);
796 if (!s
->offset
&& val
== SLUB_RED_ACTIVE
)
798 * Object and freepointer overlap. Cannot check
799 * freepointer while object is allocated.
803 /* Check free pointer validity */
804 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
805 object_err(s
, page
, p
, "Freepointer corrupt");
807 * No choice but to zap it and thus lose the remainder
808 * of the free objects in this slab. May cause
809 * another error because the object count is now wrong.
811 set_freepointer(s
, p
, NULL
);
817 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
821 VM_BUG_ON(!irqs_disabled());
823 if (!PageSlab(page
)) {
824 slab_err(s
, page
, "Not a valid slab page");
828 maxobj
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
829 if (page
->objects
> maxobj
) {
830 slab_err(s
, page
, "objects %u > max %u",
831 s
->name
, page
->objects
, maxobj
);
834 if (page
->inuse
> page
->objects
) {
835 slab_err(s
, page
, "inuse %u > max %u",
836 s
->name
, page
->inuse
, page
->objects
);
839 /* Slab_pad_check fixes things up after itself */
840 slab_pad_check(s
, page
);
845 * Determine if a certain object on a page is on the freelist. Must hold the
846 * slab lock to guarantee that the chains are in a consistent state.
848 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
853 unsigned long max_objects
;
856 while (fp
&& nr
<= page
->objects
) {
859 if (!check_valid_pointer(s
, page
, fp
)) {
861 object_err(s
, page
, object
,
862 "Freechain corrupt");
863 set_freepointer(s
, object
, NULL
);
866 slab_err(s
, page
, "Freepointer corrupt");
867 page
->freelist
= NULL
;
868 page
->inuse
= page
->objects
;
869 slab_fix(s
, "Freelist cleared");
875 fp
= get_freepointer(s
, object
);
879 max_objects
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
880 if (max_objects
> MAX_OBJS_PER_PAGE
)
881 max_objects
= MAX_OBJS_PER_PAGE
;
883 if (page
->objects
!= max_objects
) {
884 slab_err(s
, page
, "Wrong number of objects. Found %d but "
885 "should be %d", page
->objects
, max_objects
);
886 page
->objects
= max_objects
;
887 slab_fix(s
, "Number of objects adjusted.");
889 if (page
->inuse
!= page
->objects
- nr
) {
890 slab_err(s
, page
, "Wrong object count. Counter is %d but "
891 "counted were %d", page
->inuse
, page
->objects
- nr
);
892 page
->inuse
= page
->objects
- nr
;
893 slab_fix(s
, "Object count adjusted.");
895 return search
== NULL
;
898 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
,
901 if (s
->flags
& SLAB_TRACE
) {
902 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
904 alloc
? "alloc" : "free",
909 print_section("Object ", (void *)object
, s
->object_size
);
916 * Hooks for other subsystems that check memory allocations. In a typical
917 * production configuration these hooks all should produce no code at all.
919 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
921 flags
&= gfp_allowed_mask
;
922 lockdep_trace_alloc(flags
);
923 might_sleep_if(flags
& __GFP_WAIT
);
925 return should_failslab(s
->object_size
, flags
, s
->flags
);
928 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
, void *object
)
930 flags
&= gfp_allowed_mask
;
931 kmemcheck_slab_alloc(s
, flags
, object
, slab_ksize(s
));
932 kmemleak_alloc_recursive(object
, s
->object_size
, 1, s
->flags
, flags
);
935 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
)
937 kmemleak_free_recursive(x
, s
->flags
);
940 * Trouble is that we may no longer disable interupts in the fast path
941 * So in order to make the debug calls that expect irqs to be
942 * disabled we need to disable interrupts temporarily.
944 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
948 local_irq_save(flags
);
949 kmemcheck_slab_free(s
, x
, s
->object_size
);
950 debug_check_no_locks_freed(x
, s
->object_size
);
951 local_irq_restore(flags
);
954 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
955 debug_check_no_obj_freed(x
, s
->object_size
);
959 * Tracking of fully allocated slabs for debugging purposes.
961 * list_lock must be held.
963 static void add_full(struct kmem_cache
*s
,
964 struct kmem_cache_node
*n
, struct page
*page
)
966 if (!(s
->flags
& SLAB_STORE_USER
))
969 list_add(&page
->lru
, &n
->full
);
973 * list_lock must be held.
975 static void remove_full(struct kmem_cache
*s
, struct page
*page
)
977 if (!(s
->flags
& SLAB_STORE_USER
))
980 list_del(&page
->lru
);
983 /* Tracking of the number of slabs for debugging purposes */
984 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
986 struct kmem_cache_node
*n
= get_node(s
, node
);
988 return atomic_long_read(&n
->nr_slabs
);
991 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
993 return atomic_long_read(&n
->nr_slabs
);
996 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
998 struct kmem_cache_node
*n
= get_node(s
, node
);
1001 * May be called early in order to allocate a slab for the
1002 * kmem_cache_node structure. Solve the chicken-egg
1003 * dilemma by deferring the increment of the count during
1004 * bootstrap (see early_kmem_cache_node_alloc).
1007 atomic_long_inc(&n
->nr_slabs
);
1008 atomic_long_add(objects
, &n
->total_objects
);
1011 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1013 struct kmem_cache_node
*n
= get_node(s
, node
);
1015 atomic_long_dec(&n
->nr_slabs
);
1016 atomic_long_sub(objects
, &n
->total_objects
);
1019 /* Object debug checks for alloc/free paths */
1020 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
1023 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
1026 init_object(s
, object
, SLUB_RED_INACTIVE
);
1027 init_tracking(s
, object
);
1030 static noinline
int alloc_debug_processing(struct kmem_cache
*s
, struct page
*page
,
1031 void *object
, unsigned long addr
)
1033 if (!check_slab(s
, page
))
1036 if (!check_valid_pointer(s
, page
, object
)) {
1037 object_err(s
, page
, object
, "Freelist Pointer check fails");
1041 if (!check_object(s
, page
, object
, SLUB_RED_INACTIVE
))
1044 /* Success perform special debug activities for allocs */
1045 if (s
->flags
& SLAB_STORE_USER
)
1046 set_track(s
, object
, TRACK_ALLOC
, addr
);
1047 trace(s
, page
, object
, 1);
1048 init_object(s
, object
, SLUB_RED_ACTIVE
);
1052 if (PageSlab(page
)) {
1054 * If this is a slab page then lets do the best we can
1055 * to avoid issues in the future. Marking all objects
1056 * as used avoids touching the remaining objects.
1058 slab_fix(s
, "Marking all objects used");
1059 page
->inuse
= page
->objects
;
1060 page
->freelist
= NULL
;
1065 static noinline
struct kmem_cache_node
*free_debug_processing(
1066 struct kmem_cache
*s
, struct page
*page
, void *object
,
1067 unsigned long addr
, unsigned long *flags
)
1069 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1071 spin_lock_irqsave(&n
->list_lock
, *flags
);
1074 if (!check_slab(s
, page
))
1077 if (!check_valid_pointer(s
, page
, object
)) {
1078 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
1082 if (on_freelist(s
, page
, object
)) {
1083 object_err(s
, page
, object
, "Object already free");
1087 if (!check_object(s
, page
, object
, SLUB_RED_ACTIVE
))
1090 if (unlikely(s
!= page
->slab_cache
)) {
1091 if (!PageSlab(page
)) {
1092 slab_err(s
, page
, "Attempt to free object(0x%p) "
1093 "outside of slab", object
);
1094 } else if (!page
->slab_cache
) {
1096 "SLUB <none>: no slab for object 0x%p.\n",
1100 object_err(s
, page
, object
,
1101 "page slab pointer corrupt.");
1105 if (s
->flags
& SLAB_STORE_USER
)
1106 set_track(s
, object
, TRACK_FREE
, addr
);
1107 trace(s
, page
, object
, 0);
1108 init_object(s
, object
, SLUB_RED_INACTIVE
);
1112 * Keep node_lock to preserve integrity
1113 * until the object is actually freed
1119 spin_unlock_irqrestore(&n
->list_lock
, *flags
);
1120 slab_fix(s
, "Object at 0x%p not freed", object
);
1124 static int __init
setup_slub_debug(char *str
)
1126 slub_debug
= DEBUG_DEFAULT_FLAGS
;
1127 if (*str
++ != '=' || !*str
)
1129 * No options specified. Switch on full debugging.
1135 * No options but restriction on slabs. This means full
1136 * debugging for slabs matching a pattern.
1140 if (tolower(*str
) == 'o') {
1142 * Avoid enabling debugging on caches if its minimum order
1143 * would increase as a result.
1145 disable_higher_order_debug
= 1;
1152 * Switch off all debugging measures.
1157 * Determine which debug features should be switched on
1159 for (; *str
&& *str
!= ','; str
++) {
1160 switch (tolower(*str
)) {
1162 slub_debug
|= SLAB_DEBUG_FREE
;
1165 slub_debug
|= SLAB_RED_ZONE
;
1168 slub_debug
|= SLAB_POISON
;
1171 slub_debug
|= SLAB_STORE_USER
;
1174 slub_debug
|= SLAB_TRACE
;
1177 slub_debug
|= SLAB_FAILSLAB
;
1180 printk(KERN_ERR
"slub_debug option '%c' "
1181 "unknown. skipped\n", *str
);
1187 slub_debug_slabs
= str
+ 1;
1192 __setup("slub_debug", setup_slub_debug
);
1194 static unsigned long kmem_cache_flags(unsigned long object_size
,
1195 unsigned long flags
, const char *name
,
1196 void (*ctor
)(void *))
1199 * Enable debugging if selected on the kernel commandline.
1201 if (slub_debug
&& (!slub_debug_slabs
||
1202 !strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
))))
1203 flags
|= slub_debug
;
1208 static inline void setup_object_debug(struct kmem_cache
*s
,
1209 struct page
*page
, void *object
) {}
1211 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1212 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1214 static inline struct kmem_cache_node
*free_debug_processing(
1215 struct kmem_cache
*s
, struct page
*page
, void *object
,
1216 unsigned long addr
, unsigned long *flags
) { return NULL
; }
1218 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1220 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1221 void *object
, u8 val
) { return 1; }
1222 static inline void add_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1223 struct page
*page
) {}
1224 static inline void remove_full(struct kmem_cache
*s
, struct page
*page
) {}
1225 static inline unsigned long kmem_cache_flags(unsigned long object_size
,
1226 unsigned long flags
, const char *name
,
1227 void (*ctor
)(void *))
1231 #define slub_debug 0
1233 #define disable_higher_order_debug 0
1235 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1237 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1239 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1241 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1244 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
1247 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
,
1250 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
) {}
1252 #endif /* CONFIG_SLUB_DEBUG */
1255 * Slab allocation and freeing
1257 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1258 struct kmem_cache_order_objects oo
)
1260 int order
= oo_order(oo
);
1262 flags
|= __GFP_NOTRACK
;
1264 if (node
== NUMA_NO_NODE
)
1265 return alloc_pages(flags
, order
);
1267 return alloc_pages_exact_node(node
, flags
, order
);
1270 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1273 struct kmem_cache_order_objects oo
= s
->oo
;
1276 flags
&= gfp_allowed_mask
;
1278 if (flags
& __GFP_WAIT
)
1281 flags
|= s
->allocflags
;
1284 * Let the initial higher-order allocation fail under memory pressure
1285 * so we fall-back to the minimum order allocation.
1287 alloc_gfp
= (flags
| __GFP_NOWARN
| __GFP_NORETRY
) & ~__GFP_NOFAIL
;
1289 page
= alloc_slab_page(alloc_gfp
, node
, oo
);
1290 if (unlikely(!page
)) {
1293 * Allocation may have failed due to fragmentation.
1294 * Try a lower order alloc if possible
1296 page
= alloc_slab_page(flags
, node
, oo
);
1299 stat(s
, ORDER_FALLBACK
);
1302 if (kmemcheck_enabled
&& page
1303 && !(s
->flags
& (SLAB_NOTRACK
| DEBUG_DEFAULT_FLAGS
))) {
1304 int pages
= 1 << oo_order(oo
);
1306 kmemcheck_alloc_shadow(page
, oo_order(oo
), flags
, node
);
1309 * Objects from caches that have a constructor don't get
1310 * cleared when they're allocated, so we need to do it here.
1313 kmemcheck_mark_uninitialized_pages(page
, pages
);
1315 kmemcheck_mark_unallocated_pages(page
, pages
);
1318 if (flags
& __GFP_WAIT
)
1319 local_irq_disable();
1323 page
->objects
= oo_objects(oo
);
1324 mod_zone_page_state(page_zone(page
),
1325 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1326 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1332 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1335 setup_object_debug(s
, page
, object
);
1336 if (unlikely(s
->ctor
))
1340 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1347 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1349 page
= allocate_slab(s
,
1350 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1354 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1355 page
->slab_cache
= s
;
1356 __SetPageSlab(page
);
1357 if (page
->pfmemalloc
)
1358 SetPageSlabPfmemalloc(page
);
1360 start
= page_address(page
);
1362 if (unlikely(s
->flags
& SLAB_POISON
))
1363 memset(start
, POISON_INUSE
, PAGE_SIZE
<< compound_order(page
));
1366 for_each_object(p
, s
, start
, page
->objects
) {
1367 setup_object(s
, page
, last
);
1368 set_freepointer(s
, last
, p
);
1371 setup_object(s
, page
, last
);
1372 set_freepointer(s
, last
, NULL
);
1374 page
->freelist
= start
;
1375 page
->inuse
= page
->objects
;
1381 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1383 int order
= compound_order(page
);
1384 int pages
= 1 << order
;
1386 if (kmem_cache_debug(s
)) {
1389 slab_pad_check(s
, page
);
1390 for_each_object(p
, s
, page_address(page
),
1392 check_object(s
, page
, p
, SLUB_RED_INACTIVE
);
1395 kmemcheck_free_shadow(page
, compound_order(page
));
1397 mod_zone_page_state(page_zone(page
),
1398 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1399 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1402 __ClearPageSlabPfmemalloc(page
);
1403 __ClearPageSlab(page
);
1404 reset_page_mapcount(page
);
1405 if (current
->reclaim_state
)
1406 current
->reclaim_state
->reclaimed_slab
+= pages
;
1407 __free_pages(page
, order
);
1410 #define need_reserve_slab_rcu \
1411 (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
1413 static void rcu_free_slab(struct rcu_head
*h
)
1417 if (need_reserve_slab_rcu
)
1418 page
= virt_to_head_page(h
);
1420 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1422 __free_slab(page
->slab_cache
, page
);
1425 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1427 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1428 struct rcu_head
*head
;
1430 if (need_reserve_slab_rcu
) {
1431 int order
= compound_order(page
);
1432 int offset
= (PAGE_SIZE
<< order
) - s
->reserved
;
1434 VM_BUG_ON(s
->reserved
!= sizeof(*head
));
1435 head
= page_address(page
) + offset
;
1438 * RCU free overloads the RCU head over the LRU
1440 head
= (void *)&page
->lru
;
1443 call_rcu(head
, rcu_free_slab
);
1445 __free_slab(s
, page
);
1448 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1450 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1455 * Management of partially allocated slabs.
1457 * list_lock must be held.
1459 static inline void add_partial(struct kmem_cache_node
*n
,
1460 struct page
*page
, int tail
)
1463 if (tail
== DEACTIVATE_TO_TAIL
)
1464 list_add_tail(&page
->lru
, &n
->partial
);
1466 list_add(&page
->lru
, &n
->partial
);
1470 * list_lock must be held.
1472 static inline void remove_partial(struct kmem_cache_node
*n
,
1475 list_del(&page
->lru
);
1480 * Remove slab from the partial list, freeze it and
1481 * return the pointer to the freelist.
1483 * Returns a list of objects or NULL if it fails.
1485 * Must hold list_lock since we modify the partial list.
1487 static inline void *acquire_slab(struct kmem_cache
*s
,
1488 struct kmem_cache_node
*n
, struct page
*page
,
1492 unsigned long counters
;
1496 * Zap the freelist and set the frozen bit.
1497 * The old freelist is the list of objects for the
1498 * per cpu allocation list.
1500 freelist
= page
->freelist
;
1501 counters
= page
->counters
;
1502 new.counters
= counters
;
1504 new.inuse
= page
->objects
;
1505 new.freelist
= NULL
;
1507 new.freelist
= freelist
;
1510 VM_BUG_ON(new.frozen
);
1513 if (!__cmpxchg_double_slab(s
, page
,
1515 new.freelist
, new.counters
,
1519 remove_partial(n
, page
);
1524 static int put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
);
1525 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
);
1528 * Try to allocate a partial slab from a specific node.
1530 static void *get_partial_node(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1531 struct kmem_cache_cpu
*c
, gfp_t flags
)
1533 struct page
*page
, *page2
;
1534 void *object
= NULL
;
1537 * Racy check. If we mistakenly see no partial slabs then we
1538 * just allocate an empty slab. If we mistakenly try to get a
1539 * partial slab and there is none available then get_partials()
1542 if (!n
|| !n
->nr_partial
)
1545 spin_lock(&n
->list_lock
);
1546 list_for_each_entry_safe(page
, page2
, &n
->partial
, lru
) {
1550 if (!pfmemalloc_match(page
, flags
))
1553 t
= acquire_slab(s
, n
, page
, object
== NULL
);
1559 stat(s
, ALLOC_FROM_PARTIAL
);
1561 available
= page
->objects
- page
->inuse
;
1563 available
= put_cpu_partial(s
, page
, 0);
1564 stat(s
, CPU_PARTIAL_NODE
);
1566 if (kmem_cache_debug(s
) || available
> s
->cpu_partial
/ 2)
1570 spin_unlock(&n
->list_lock
);
1575 * Get a page from somewhere. Search in increasing NUMA distances.
1577 static void *get_any_partial(struct kmem_cache
*s
, gfp_t flags
,
1578 struct kmem_cache_cpu
*c
)
1581 struct zonelist
*zonelist
;
1584 enum zone_type high_zoneidx
= gfp_zone(flags
);
1586 unsigned int cpuset_mems_cookie
;
1589 * The defrag ratio allows a configuration of the tradeoffs between
1590 * inter node defragmentation and node local allocations. A lower
1591 * defrag_ratio increases the tendency to do local allocations
1592 * instead of attempting to obtain partial slabs from other nodes.
1594 * If the defrag_ratio is set to 0 then kmalloc() always
1595 * returns node local objects. If the ratio is higher then kmalloc()
1596 * may return off node objects because partial slabs are obtained
1597 * from other nodes and filled up.
1599 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1600 * defrag_ratio = 1000) then every (well almost) allocation will
1601 * first attempt to defrag slab caches on other nodes. This means
1602 * scanning over all nodes to look for partial slabs which may be
1603 * expensive if we do it every time we are trying to find a slab
1604 * with available objects.
1606 if (!s
->remote_node_defrag_ratio
||
1607 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1611 cpuset_mems_cookie
= get_mems_allowed();
1612 zonelist
= node_zonelist(slab_node(), flags
);
1613 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
1614 struct kmem_cache_node
*n
;
1616 n
= get_node(s
, zone_to_nid(zone
));
1618 if (n
&& cpuset_zone_allowed_hardwall(zone
, flags
) &&
1619 n
->nr_partial
> s
->min_partial
) {
1620 object
= get_partial_node(s
, n
, c
, flags
);
1623 * Return the object even if
1624 * put_mems_allowed indicated that
1625 * the cpuset mems_allowed was
1626 * updated in parallel. It's a
1627 * harmless race between the alloc
1628 * and the cpuset update.
1630 put_mems_allowed(cpuset_mems_cookie
);
1635 } while (!put_mems_allowed(cpuset_mems_cookie
));
1641 * Get a partial page, lock it and return it.
1643 static void *get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
,
1644 struct kmem_cache_cpu
*c
)
1647 int searchnode
= (node
== NUMA_NO_NODE
) ? numa_node_id() : node
;
1649 object
= get_partial_node(s
, get_node(s
, searchnode
), c
, flags
);
1650 if (object
|| node
!= NUMA_NO_NODE
)
1653 return get_any_partial(s
, flags
, c
);
1656 #ifdef CONFIG_PREEMPT
1658 * Calculate the next globally unique transaction for disambiguiation
1659 * during cmpxchg. The transactions start with the cpu number and are then
1660 * incremented by CONFIG_NR_CPUS.
1662 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1665 * No preemption supported therefore also no need to check for
1671 static inline unsigned long next_tid(unsigned long tid
)
1673 return tid
+ TID_STEP
;
1676 static inline unsigned int tid_to_cpu(unsigned long tid
)
1678 return tid
% TID_STEP
;
1681 static inline unsigned long tid_to_event(unsigned long tid
)
1683 return tid
/ TID_STEP
;
1686 static inline unsigned int init_tid(int cpu
)
1691 static inline void note_cmpxchg_failure(const char *n
,
1692 const struct kmem_cache
*s
, unsigned long tid
)
1694 #ifdef SLUB_DEBUG_CMPXCHG
1695 unsigned long actual_tid
= __this_cpu_read(s
->cpu_slab
->tid
);
1697 printk(KERN_INFO
"%s %s: cmpxchg redo ", n
, s
->name
);
1699 #ifdef CONFIG_PREEMPT
1700 if (tid_to_cpu(tid
) != tid_to_cpu(actual_tid
))
1701 printk("due to cpu change %d -> %d\n",
1702 tid_to_cpu(tid
), tid_to_cpu(actual_tid
));
1705 if (tid_to_event(tid
) != tid_to_event(actual_tid
))
1706 printk("due to cpu running other code. Event %ld->%ld\n",
1707 tid_to_event(tid
), tid_to_event(actual_tid
));
1709 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1710 actual_tid
, tid
, next_tid(tid
));
1712 stat(s
, CMPXCHG_DOUBLE_CPU_FAIL
);
1715 static void init_kmem_cache_cpus(struct kmem_cache
*s
)
1719 for_each_possible_cpu(cpu
)
1720 per_cpu_ptr(s
->cpu_slab
, cpu
)->tid
= init_tid(cpu
);
1724 * Remove the cpu slab
1726 static void deactivate_slab(struct kmem_cache
*s
, struct page
*page
, void *freelist
)
1728 enum slab_modes
{ M_NONE
, M_PARTIAL
, M_FULL
, M_FREE
};
1729 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1731 enum slab_modes l
= M_NONE
, m
= M_NONE
;
1733 int tail
= DEACTIVATE_TO_HEAD
;
1737 if (page
->freelist
) {
1738 stat(s
, DEACTIVATE_REMOTE_FREES
);
1739 tail
= DEACTIVATE_TO_TAIL
;
1743 * Stage one: Free all available per cpu objects back
1744 * to the page freelist while it is still frozen. Leave the
1747 * There is no need to take the list->lock because the page
1750 while (freelist
&& (nextfree
= get_freepointer(s
, freelist
))) {
1752 unsigned long counters
;
1755 prior
= page
->freelist
;
1756 counters
= page
->counters
;
1757 set_freepointer(s
, freelist
, prior
);
1758 new.counters
= counters
;
1760 VM_BUG_ON(!new.frozen
);
1762 } while (!__cmpxchg_double_slab(s
, page
,
1764 freelist
, new.counters
,
1765 "drain percpu freelist"));
1767 freelist
= nextfree
;
1771 * Stage two: Ensure that the page is unfrozen while the
1772 * list presence reflects the actual number of objects
1775 * We setup the list membership and then perform a cmpxchg
1776 * with the count. If there is a mismatch then the page
1777 * is not unfrozen but the page is on the wrong list.
1779 * Then we restart the process which may have to remove
1780 * the page from the list that we just put it on again
1781 * because the number of objects in the slab may have
1786 old
.freelist
= page
->freelist
;
1787 old
.counters
= page
->counters
;
1788 VM_BUG_ON(!old
.frozen
);
1790 /* Determine target state of the slab */
1791 new.counters
= old
.counters
;
1794 set_freepointer(s
, freelist
, old
.freelist
);
1795 new.freelist
= freelist
;
1797 new.freelist
= old
.freelist
;
1801 if (!new.inuse
&& n
->nr_partial
> s
->min_partial
)
1803 else if (new.freelist
) {
1808 * Taking the spinlock removes the possiblity
1809 * that acquire_slab() will see a slab page that
1812 spin_lock(&n
->list_lock
);
1816 if (kmem_cache_debug(s
) && !lock
) {
1819 * This also ensures that the scanning of full
1820 * slabs from diagnostic functions will not see
1823 spin_lock(&n
->list_lock
);
1831 remove_partial(n
, page
);
1833 else if (l
== M_FULL
)
1835 remove_full(s
, page
);
1837 if (m
== M_PARTIAL
) {
1839 add_partial(n
, page
, tail
);
1842 } else if (m
== M_FULL
) {
1844 stat(s
, DEACTIVATE_FULL
);
1845 add_full(s
, n
, page
);
1851 if (!__cmpxchg_double_slab(s
, page
,
1852 old
.freelist
, old
.counters
,
1853 new.freelist
, new.counters
,
1858 spin_unlock(&n
->list_lock
);
1861 stat(s
, DEACTIVATE_EMPTY
);
1862 discard_slab(s
, page
);
1868 * Unfreeze all the cpu partial slabs.
1870 * This function must be called with interrupts disabled
1871 * for the cpu using c (or some other guarantee must be there
1872 * to guarantee no concurrent accesses).
1874 static void unfreeze_partials(struct kmem_cache
*s
,
1875 struct kmem_cache_cpu
*c
)
1877 struct kmem_cache_node
*n
= NULL
, *n2
= NULL
;
1878 struct page
*page
, *discard_page
= NULL
;
1880 while ((page
= c
->partial
)) {
1884 c
->partial
= page
->next
;
1886 n2
= get_node(s
, page_to_nid(page
));
1889 spin_unlock(&n
->list_lock
);
1892 spin_lock(&n
->list_lock
);
1897 old
.freelist
= page
->freelist
;
1898 old
.counters
= page
->counters
;
1899 VM_BUG_ON(!old
.frozen
);
1901 new.counters
= old
.counters
;
1902 new.freelist
= old
.freelist
;
1906 } while (!__cmpxchg_double_slab(s
, page
,
1907 old
.freelist
, old
.counters
,
1908 new.freelist
, new.counters
,
1909 "unfreezing slab"));
1911 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
)) {
1912 page
->next
= discard_page
;
1913 discard_page
= page
;
1915 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
1916 stat(s
, FREE_ADD_PARTIAL
);
1921 spin_unlock(&n
->list_lock
);
1923 while (discard_page
) {
1924 page
= discard_page
;
1925 discard_page
= discard_page
->next
;
1927 stat(s
, DEACTIVATE_EMPTY
);
1928 discard_slab(s
, page
);
1934 * Put a page that was just frozen (in __slab_free) into a partial page
1935 * slot if available. This is done without interrupts disabled and without
1936 * preemption disabled. The cmpxchg is racy and may put the partial page
1937 * onto a random cpus partial slot.
1939 * If we did not find a slot then simply move all the partials to the
1940 * per node partial list.
1942 static int put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
)
1944 struct page
*oldpage
;
1951 oldpage
= this_cpu_read(s
->cpu_slab
->partial
);
1954 pobjects
= oldpage
->pobjects
;
1955 pages
= oldpage
->pages
;
1956 if (drain
&& pobjects
> s
->cpu_partial
) {
1957 unsigned long flags
;
1959 * partial array is full. Move the existing
1960 * set to the per node partial list.
1962 local_irq_save(flags
);
1963 unfreeze_partials(s
, this_cpu_ptr(s
->cpu_slab
));
1964 local_irq_restore(flags
);
1968 stat(s
, CPU_PARTIAL_DRAIN
);
1973 pobjects
+= page
->objects
- page
->inuse
;
1975 page
->pages
= pages
;
1976 page
->pobjects
= pobjects
;
1977 page
->next
= oldpage
;
1979 } while (this_cpu_cmpxchg(s
->cpu_slab
->partial
, oldpage
, page
) != oldpage
);
1983 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1985 stat(s
, CPUSLAB_FLUSH
);
1986 deactivate_slab(s
, c
->page
, c
->freelist
);
1988 c
->tid
= next_tid(c
->tid
);
1996 * Called from IPI handler with interrupts disabled.
1998 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
2000 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2006 unfreeze_partials(s
, c
);
2010 static void flush_cpu_slab(void *d
)
2012 struct kmem_cache
*s
= d
;
2014 __flush_cpu_slab(s
, smp_processor_id());
2017 static bool has_cpu_slab(int cpu
, void *info
)
2019 struct kmem_cache
*s
= info
;
2020 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2022 return c
->page
|| c
->partial
;
2025 static void flush_all(struct kmem_cache
*s
)
2027 on_each_cpu_cond(has_cpu_slab
, flush_cpu_slab
, s
, 1, GFP_ATOMIC
);
2031 * Check if the objects in a per cpu structure fit numa
2032 * locality expectations.
2034 static inline int node_match(struct page
*page
, int node
)
2037 if (node
!= NUMA_NO_NODE
&& page_to_nid(page
) != node
)
2043 static int count_free(struct page
*page
)
2045 return page
->objects
- page
->inuse
;
2048 static unsigned long count_partial(struct kmem_cache_node
*n
,
2049 int (*get_count
)(struct page
*))
2051 unsigned long flags
;
2052 unsigned long x
= 0;
2055 spin_lock_irqsave(&n
->list_lock
, flags
);
2056 list_for_each_entry(page
, &n
->partial
, lru
)
2057 x
+= get_count(page
);
2058 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2062 static inline unsigned long node_nr_objs(struct kmem_cache_node
*n
)
2064 #ifdef CONFIG_SLUB_DEBUG
2065 return atomic_long_read(&n
->total_objects
);
2071 static noinline
void
2072 slab_out_of_memory(struct kmem_cache
*s
, gfp_t gfpflags
, int nid
)
2077 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
2079 printk(KERN_WARNING
" cache: %s, object size: %d, buffer size: %d, "
2080 "default order: %d, min order: %d\n", s
->name
, s
->object_size
,
2081 s
->size
, oo_order(s
->oo
), oo_order(s
->min
));
2083 if (oo_order(s
->min
) > get_order(s
->object_size
))
2084 printk(KERN_WARNING
" %s debugging increased min order, use "
2085 "slub_debug=O to disable.\n", s
->name
);
2087 for_each_online_node(node
) {
2088 struct kmem_cache_node
*n
= get_node(s
, node
);
2089 unsigned long nr_slabs
;
2090 unsigned long nr_objs
;
2091 unsigned long nr_free
;
2096 nr_free
= count_partial(n
, count_free
);
2097 nr_slabs
= node_nr_slabs(n
);
2098 nr_objs
= node_nr_objs(n
);
2101 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
2102 node
, nr_slabs
, nr_objs
, nr_free
);
2106 static inline void *new_slab_objects(struct kmem_cache
*s
, gfp_t flags
,
2107 int node
, struct kmem_cache_cpu
**pc
)
2110 struct kmem_cache_cpu
*c
= *pc
;
2113 freelist
= get_partial(s
, flags
, node
, c
);
2118 page
= new_slab(s
, flags
, node
);
2120 c
= __this_cpu_ptr(s
->cpu_slab
);
2125 * No other reference to the page yet so we can
2126 * muck around with it freely without cmpxchg
2128 freelist
= page
->freelist
;
2129 page
->freelist
= NULL
;
2131 stat(s
, ALLOC_SLAB
);
2140 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
)
2142 if (unlikely(PageSlabPfmemalloc(page
)))
2143 return gfp_pfmemalloc_allowed(gfpflags
);
2149 * Check the page->freelist of a page and either transfer the freelist to the per cpu freelist
2150 * or deactivate the page.
2152 * The page is still frozen if the return value is not NULL.
2154 * If this function returns NULL then the page has been unfrozen.
2156 * This function must be called with interrupt disabled.
2158 static inline void *get_freelist(struct kmem_cache
*s
, struct page
*page
)
2161 unsigned long counters
;
2165 freelist
= page
->freelist
;
2166 counters
= page
->counters
;
2168 new.counters
= counters
;
2169 VM_BUG_ON(!new.frozen
);
2171 new.inuse
= page
->objects
;
2172 new.frozen
= freelist
!= NULL
;
2174 } while (!__cmpxchg_double_slab(s
, page
,
2183 * Slow path. The lockless freelist is empty or we need to perform
2186 * Processing is still very fast if new objects have been freed to the
2187 * regular freelist. In that case we simply take over the regular freelist
2188 * as the lockless freelist and zap the regular freelist.
2190 * If that is not working then we fall back to the partial lists. We take the
2191 * first element of the freelist as the object to allocate now and move the
2192 * rest of the freelist to the lockless freelist.
2194 * And if we were unable to get a new slab from the partial slab lists then
2195 * we need to allocate a new slab. This is the slowest path since it involves
2196 * a call to the page allocator and the setup of a new slab.
2198 static void *__slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, int node
,
2199 unsigned long addr
, struct kmem_cache_cpu
*c
)
2203 unsigned long flags
;
2205 local_irq_save(flags
);
2206 #ifdef CONFIG_PREEMPT
2208 * We may have been preempted and rescheduled on a different
2209 * cpu before disabling interrupts. Need to reload cpu area
2212 c
= this_cpu_ptr(s
->cpu_slab
);
2220 if (unlikely(!node_match(page
, node
))) {
2221 stat(s
, ALLOC_NODE_MISMATCH
);
2222 deactivate_slab(s
, page
, c
->freelist
);
2229 * By rights, we should be searching for a slab page that was
2230 * PFMEMALLOC but right now, we are losing the pfmemalloc
2231 * information when the page leaves the per-cpu allocator
2233 if (unlikely(!pfmemalloc_match(page
, gfpflags
))) {
2234 deactivate_slab(s
, page
, c
->freelist
);
2240 /* must check again c->freelist in case of cpu migration or IRQ */
2241 freelist
= c
->freelist
;
2245 stat(s
, ALLOC_SLOWPATH
);
2247 freelist
= get_freelist(s
, page
);
2251 stat(s
, DEACTIVATE_BYPASS
);
2255 stat(s
, ALLOC_REFILL
);
2259 * freelist is pointing to the list of objects to be used.
2260 * page is pointing to the page from which the objects are obtained.
2261 * That page must be frozen for per cpu allocations to work.
2263 VM_BUG_ON(!c
->page
->frozen
);
2264 c
->freelist
= get_freepointer(s
, freelist
);
2265 c
->tid
= next_tid(c
->tid
);
2266 local_irq_restore(flags
);
2272 page
= c
->page
= c
->partial
;
2273 c
->partial
= page
->next
;
2274 stat(s
, CPU_PARTIAL_ALLOC
);
2279 freelist
= new_slab_objects(s
, gfpflags
, node
, &c
);
2281 if (unlikely(!freelist
)) {
2282 if (!(gfpflags
& __GFP_NOWARN
) && printk_ratelimit())
2283 slab_out_of_memory(s
, gfpflags
, node
);
2285 local_irq_restore(flags
);
2290 if (likely(!kmem_cache_debug(s
) && pfmemalloc_match(page
, gfpflags
)))
2293 /* Only entered in the debug case */
2294 if (kmem_cache_debug(s
) && !alloc_debug_processing(s
, page
, freelist
, addr
))
2295 goto new_slab
; /* Slab failed checks. Next slab needed */
2297 deactivate_slab(s
, page
, get_freepointer(s
, freelist
));
2300 local_irq_restore(flags
);
2305 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
2306 * have the fastpath folded into their functions. So no function call
2307 * overhead for requests that can be satisfied on the fastpath.
2309 * The fastpath works by first checking if the lockless freelist can be used.
2310 * If not then __slab_alloc is called for slow processing.
2312 * Otherwise we can simply pick the next object from the lockless free list.
2314 static __always_inline
void *slab_alloc_node(struct kmem_cache
*s
,
2315 gfp_t gfpflags
, int node
, unsigned long addr
)
2318 struct kmem_cache_cpu
*c
;
2322 if (slab_pre_alloc_hook(s
, gfpflags
))
2328 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
2329 * enabled. We may switch back and forth between cpus while
2330 * reading from one cpu area. That does not matter as long
2331 * as we end up on the original cpu again when doing the cmpxchg.
2333 c
= __this_cpu_ptr(s
->cpu_slab
);
2336 * The transaction ids are globally unique per cpu and per operation on
2337 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
2338 * occurs on the right processor and that there was no operation on the
2339 * linked list in between.
2344 object
= c
->freelist
;
2346 if (unlikely(!object
|| !node_match(page
, node
)))
2347 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
2350 void *next_object
= get_freepointer_safe(s
, object
);
2353 * The cmpxchg will only match if there was no additional
2354 * operation and if we are on the right processor.
2356 * The cmpxchg does the following atomically (without lock semantics!)
2357 * 1. Relocate first pointer to the current per cpu area.
2358 * 2. Verify that tid and freelist have not been changed
2359 * 3. If they were not changed replace tid and freelist
2361 * Since this is without lock semantics the protection is only against
2362 * code executing on this cpu *not* from access by other cpus.
2364 if (unlikely(!this_cpu_cmpxchg_double(
2365 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2367 next_object
, next_tid(tid
)))) {
2369 note_cmpxchg_failure("slab_alloc", s
, tid
);
2372 prefetch_freepointer(s
, next_object
);
2373 stat(s
, ALLOC_FASTPATH
);
2376 if (unlikely(gfpflags
& __GFP_ZERO
) && object
)
2377 memset(object
, 0, s
->object_size
);
2379 slab_post_alloc_hook(s
, gfpflags
, object
);
2384 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
2385 gfp_t gfpflags
, unsigned long addr
)
2387 return slab_alloc_node(s
, gfpflags
, NUMA_NO_NODE
, addr
);
2390 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
2392 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2394 trace_kmem_cache_alloc(_RET_IP_
, ret
, s
->object_size
, s
->size
, gfpflags
);
2398 EXPORT_SYMBOL(kmem_cache_alloc
);
2400 #ifdef CONFIG_TRACING
2401 void *kmem_cache_alloc_trace(struct kmem_cache
*s
, gfp_t gfpflags
, size_t size
)
2403 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2404 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, gfpflags
);
2407 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
2409 void *kmalloc_order_trace(size_t size
, gfp_t flags
, unsigned int order
)
2411 void *ret
= kmalloc_order(size
, flags
, order
);
2412 trace_kmalloc(_RET_IP_
, ret
, size
, PAGE_SIZE
<< order
, flags
);
2415 EXPORT_SYMBOL(kmalloc_order_trace
);
2419 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
2421 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2423 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
2424 s
->object_size
, s
->size
, gfpflags
, node
);
2428 EXPORT_SYMBOL(kmem_cache_alloc_node
);
2430 #ifdef CONFIG_TRACING
2431 void *kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
2433 int node
, size_t size
)
2435 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2437 trace_kmalloc_node(_RET_IP_
, ret
,
2438 size
, s
->size
, gfpflags
, node
);
2441 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
2446 * Slow patch handling. This may still be called frequently since objects
2447 * have a longer lifetime than the cpu slabs in most processing loads.
2449 * So we still attempt to reduce cache line usage. Just take the slab
2450 * lock and free the item. If there is no additional partial page
2451 * handling required then we can return immediately.
2453 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
2454 void *x
, unsigned long addr
)
2457 void **object
= (void *)x
;
2460 unsigned long counters
;
2461 struct kmem_cache_node
*n
= NULL
;
2462 unsigned long uninitialized_var(flags
);
2464 stat(s
, FREE_SLOWPATH
);
2466 if (kmem_cache_debug(s
) &&
2467 !(n
= free_debug_processing(s
, page
, x
, addr
, &flags
)))
2472 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2475 prior
= page
->freelist
;
2476 counters
= page
->counters
;
2477 set_freepointer(s
, object
, prior
);
2478 new.counters
= counters
;
2479 was_frozen
= new.frozen
;
2481 if ((!new.inuse
|| !prior
) && !was_frozen
) {
2483 if (!kmem_cache_debug(s
) && !prior
)
2486 * Slab was on no list before and will be partially empty
2487 * We can defer the list move and instead freeze it.
2491 else { /* Needs to be taken off a list */
2493 n
= get_node(s
, page_to_nid(page
));
2495 * Speculatively acquire the list_lock.
2496 * If the cmpxchg does not succeed then we may
2497 * drop the list_lock without any processing.
2499 * Otherwise the list_lock will synchronize with
2500 * other processors updating the list of slabs.
2502 spin_lock_irqsave(&n
->list_lock
, flags
);
2507 } while (!cmpxchg_double_slab(s
, page
,
2509 object
, new.counters
,
2515 * If we just froze the page then put it onto the
2516 * per cpu partial list.
2518 if (new.frozen
&& !was_frozen
) {
2519 put_cpu_partial(s
, page
, 1);
2520 stat(s
, CPU_PARTIAL_FREE
);
2523 * The list lock was not taken therefore no list
2524 * activity can be necessary.
2527 stat(s
, FREE_FROZEN
);
2531 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
))
2535 * Objects left in the slab. If it was not on the partial list before
2538 if (kmem_cache_debug(s
) && unlikely(!prior
)) {
2539 remove_full(s
, page
);
2540 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
2541 stat(s
, FREE_ADD_PARTIAL
);
2543 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2549 * Slab on the partial list.
2551 remove_partial(n
, page
);
2552 stat(s
, FREE_REMOVE_PARTIAL
);
2554 /* Slab must be on the full list */
2555 remove_full(s
, page
);
2557 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2559 discard_slab(s
, page
);
2563 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2564 * can perform fastpath freeing without additional function calls.
2566 * The fastpath is only possible if we are freeing to the current cpu slab
2567 * of this processor. This typically the case if we have just allocated
2570 * If fastpath is not possible then fall back to __slab_free where we deal
2571 * with all sorts of special processing.
2573 static __always_inline
void slab_free(struct kmem_cache
*s
,
2574 struct page
*page
, void *x
, unsigned long addr
)
2576 void **object
= (void *)x
;
2577 struct kmem_cache_cpu
*c
;
2580 slab_free_hook(s
, x
);
2584 * Determine the currently cpus per cpu slab.
2585 * The cpu may change afterward. However that does not matter since
2586 * data is retrieved via this pointer. If we are on the same cpu
2587 * during the cmpxchg then the free will succedd.
2589 c
= __this_cpu_ptr(s
->cpu_slab
);
2594 if (likely(page
== c
->page
)) {
2595 set_freepointer(s
, object
, c
->freelist
);
2597 if (unlikely(!this_cpu_cmpxchg_double(
2598 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2600 object
, next_tid(tid
)))) {
2602 note_cmpxchg_failure("slab_free", s
, tid
);
2605 stat(s
, FREE_FASTPATH
);
2607 __slab_free(s
, page
, x
, addr
);
2611 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
2615 page
= virt_to_head_page(x
);
2617 if (kmem_cache_debug(s
) && page
->slab_cache
!= s
) {
2618 pr_err("kmem_cache_free: Wrong slab cache. %s but object"
2619 " is from %s\n", page
->slab_cache
->name
, s
->name
);
2624 slab_free(s
, page
, x
, _RET_IP_
);
2626 trace_kmem_cache_free(_RET_IP_
, x
);
2628 EXPORT_SYMBOL(kmem_cache_free
);
2631 * Object placement in a slab is made very easy because we always start at
2632 * offset 0. If we tune the size of the object to the alignment then we can
2633 * get the required alignment by putting one properly sized object after
2636 * Notice that the allocation order determines the sizes of the per cpu
2637 * caches. Each processor has always one slab available for allocations.
2638 * Increasing the allocation order reduces the number of times that slabs
2639 * must be moved on and off the partial lists and is therefore a factor in
2644 * Mininum / Maximum order of slab pages. This influences locking overhead
2645 * and slab fragmentation. A higher order reduces the number of partial slabs
2646 * and increases the number of allocations possible without having to
2647 * take the list_lock.
2649 static int slub_min_order
;
2650 static int slub_max_order
= PAGE_ALLOC_COSTLY_ORDER
;
2651 static int slub_min_objects
;
2654 * Merge control. If this is set then no merging of slab caches will occur.
2655 * (Could be removed. This was introduced to pacify the merge skeptics.)
2657 static int slub_nomerge
;
2660 * Calculate the order of allocation given an slab object size.
2662 * The order of allocation has significant impact on performance and other
2663 * system components. Generally order 0 allocations should be preferred since
2664 * order 0 does not cause fragmentation in the page allocator. Larger objects
2665 * be problematic to put into order 0 slabs because there may be too much
2666 * unused space left. We go to a higher order if more than 1/16th of the slab
2669 * In order to reach satisfactory performance we must ensure that a minimum
2670 * number of objects is in one slab. Otherwise we may generate too much
2671 * activity on the partial lists which requires taking the list_lock. This is
2672 * less a concern for large slabs though which are rarely used.
2674 * slub_max_order specifies the order where we begin to stop considering the
2675 * number of objects in a slab as critical. If we reach slub_max_order then
2676 * we try to keep the page order as low as possible. So we accept more waste
2677 * of space in favor of a small page order.
2679 * Higher order allocations also allow the placement of more objects in a
2680 * slab and thereby reduce object handling overhead. If the user has
2681 * requested a higher mininum order then we start with that one instead of
2682 * the smallest order which will fit the object.
2684 static inline int slab_order(int size
, int min_objects
,
2685 int max_order
, int fract_leftover
, int reserved
)
2689 int min_order
= slub_min_order
;
2691 if (order_objects(min_order
, size
, reserved
) > MAX_OBJS_PER_PAGE
)
2692 return get_order(size
* MAX_OBJS_PER_PAGE
) - 1;
2694 for (order
= max(min_order
,
2695 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
2696 order
<= max_order
; order
++) {
2698 unsigned long slab_size
= PAGE_SIZE
<< order
;
2700 if (slab_size
< min_objects
* size
+ reserved
)
2703 rem
= (slab_size
- reserved
) % size
;
2705 if (rem
<= slab_size
/ fract_leftover
)
2713 static inline int calculate_order(int size
, int reserved
)
2721 * Attempt to find best configuration for a slab. This
2722 * works by first attempting to generate a layout with
2723 * the best configuration and backing off gradually.
2725 * First we reduce the acceptable waste in a slab. Then
2726 * we reduce the minimum objects required in a slab.
2728 min_objects
= slub_min_objects
;
2730 min_objects
= 4 * (fls(nr_cpu_ids
) + 1);
2731 max_objects
= order_objects(slub_max_order
, size
, reserved
);
2732 min_objects
= min(min_objects
, max_objects
);
2734 while (min_objects
> 1) {
2736 while (fraction
>= 4) {
2737 order
= slab_order(size
, min_objects
,
2738 slub_max_order
, fraction
, reserved
);
2739 if (order
<= slub_max_order
)
2747 * We were unable to place multiple objects in a slab. Now
2748 * lets see if we can place a single object there.
2750 order
= slab_order(size
, 1, slub_max_order
, 1, reserved
);
2751 if (order
<= slub_max_order
)
2755 * Doh this slab cannot be placed using slub_max_order.
2757 order
= slab_order(size
, 1, MAX_ORDER
, 1, reserved
);
2758 if (order
< MAX_ORDER
)
2764 init_kmem_cache_node(struct kmem_cache_node
*n
)
2767 spin_lock_init(&n
->list_lock
);
2768 INIT_LIST_HEAD(&n
->partial
);
2769 #ifdef CONFIG_SLUB_DEBUG
2770 atomic_long_set(&n
->nr_slabs
, 0);
2771 atomic_long_set(&n
->total_objects
, 0);
2772 INIT_LIST_HEAD(&n
->full
);
2776 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
)
2778 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE
<
2779 SLUB_PAGE_SHIFT
* sizeof(struct kmem_cache_cpu
));
2782 * Must align to double word boundary for the double cmpxchg
2783 * instructions to work; see __pcpu_double_call_return_bool().
2785 s
->cpu_slab
= __alloc_percpu(sizeof(struct kmem_cache_cpu
),
2786 2 * sizeof(void *));
2791 init_kmem_cache_cpus(s
);
2796 static struct kmem_cache
*kmem_cache_node
;
2799 * No kmalloc_node yet so do it by hand. We know that this is the first
2800 * slab on the node for this slabcache. There are no concurrent accesses
2803 * Note that this function only works on the kmalloc_node_cache
2804 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2805 * memory on a fresh node that has no slab structures yet.
2807 static void early_kmem_cache_node_alloc(int node
)
2810 struct kmem_cache_node
*n
;
2812 BUG_ON(kmem_cache_node
->size
< sizeof(struct kmem_cache_node
));
2814 page
= new_slab(kmem_cache_node
, GFP_NOWAIT
, node
);
2817 if (page_to_nid(page
) != node
) {
2818 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2820 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2821 "in order to be able to continue\n");
2826 page
->freelist
= get_freepointer(kmem_cache_node
, n
);
2829 kmem_cache_node
->node
[node
] = n
;
2830 #ifdef CONFIG_SLUB_DEBUG
2831 init_object(kmem_cache_node
, n
, SLUB_RED_ACTIVE
);
2832 init_tracking(kmem_cache_node
, n
);
2834 init_kmem_cache_node(n
);
2835 inc_slabs_node(kmem_cache_node
, node
, page
->objects
);
2837 add_partial(n
, page
, DEACTIVATE_TO_HEAD
);
2840 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2844 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2845 struct kmem_cache_node
*n
= s
->node
[node
];
2848 kmem_cache_free(kmem_cache_node
, n
);
2850 s
->node
[node
] = NULL
;
2854 static int init_kmem_cache_nodes(struct kmem_cache
*s
)
2858 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2859 struct kmem_cache_node
*n
;
2861 if (slab_state
== DOWN
) {
2862 early_kmem_cache_node_alloc(node
);
2865 n
= kmem_cache_alloc_node(kmem_cache_node
,
2869 free_kmem_cache_nodes(s
);
2874 init_kmem_cache_node(n
);
2879 static void set_min_partial(struct kmem_cache
*s
, unsigned long min
)
2881 if (min
< MIN_PARTIAL
)
2883 else if (min
> MAX_PARTIAL
)
2885 s
->min_partial
= min
;
2889 * calculate_sizes() determines the order and the distribution of data within
2892 static int calculate_sizes(struct kmem_cache
*s
, int forced_order
)
2894 unsigned long flags
= s
->flags
;
2895 unsigned long size
= s
->object_size
;
2899 * Round up object size to the next word boundary. We can only
2900 * place the free pointer at word boundaries and this determines
2901 * the possible location of the free pointer.
2903 size
= ALIGN(size
, sizeof(void *));
2905 #ifdef CONFIG_SLUB_DEBUG
2907 * Determine if we can poison the object itself. If the user of
2908 * the slab may touch the object after free or before allocation
2909 * then we should never poison the object itself.
2911 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2913 s
->flags
|= __OBJECT_POISON
;
2915 s
->flags
&= ~__OBJECT_POISON
;
2919 * If we are Redzoning then check if there is some space between the
2920 * end of the object and the free pointer. If not then add an
2921 * additional word to have some bytes to store Redzone information.
2923 if ((flags
& SLAB_RED_ZONE
) && size
== s
->object_size
)
2924 size
+= sizeof(void *);
2928 * With that we have determined the number of bytes in actual use
2929 * by the object. This is the potential offset to the free pointer.
2933 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
2936 * Relocate free pointer after the object if it is not
2937 * permitted to overwrite the first word of the object on
2940 * This is the case if we do RCU, have a constructor or
2941 * destructor or are poisoning the objects.
2944 size
+= sizeof(void *);
2947 #ifdef CONFIG_SLUB_DEBUG
2948 if (flags
& SLAB_STORE_USER
)
2950 * Need to store information about allocs and frees after
2953 size
+= 2 * sizeof(struct track
);
2955 if (flags
& SLAB_RED_ZONE
)
2957 * Add some empty padding so that we can catch
2958 * overwrites from earlier objects rather than let
2959 * tracking information or the free pointer be
2960 * corrupted if a user writes before the start
2963 size
+= sizeof(void *);
2967 * SLUB stores one object immediately after another beginning from
2968 * offset 0. In order to align the objects we have to simply size
2969 * each object to conform to the alignment.
2971 size
= ALIGN(size
, s
->align
);
2973 if (forced_order
>= 0)
2974 order
= forced_order
;
2976 order
= calculate_order(size
, s
->reserved
);
2983 s
->allocflags
|= __GFP_COMP
;
2985 if (s
->flags
& SLAB_CACHE_DMA
)
2986 s
->allocflags
|= SLUB_DMA
;
2988 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
2989 s
->allocflags
|= __GFP_RECLAIMABLE
;
2992 * Determine the number of objects per slab
2994 s
->oo
= oo_make(order
, size
, s
->reserved
);
2995 s
->min
= oo_make(get_order(size
), size
, s
->reserved
);
2996 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
2999 return !!oo_objects(s
->oo
);
3002 static int kmem_cache_open(struct kmem_cache
*s
, unsigned long flags
)
3004 s
->flags
= kmem_cache_flags(s
->size
, flags
, s
->name
, s
->ctor
);
3007 if (need_reserve_slab_rcu
&& (s
->flags
& SLAB_DESTROY_BY_RCU
))
3008 s
->reserved
= sizeof(struct rcu_head
);
3010 if (!calculate_sizes(s
, -1))
3012 if (disable_higher_order_debug
) {
3014 * Disable debugging flags that store metadata if the min slab
3017 if (get_order(s
->size
) > get_order(s
->object_size
)) {
3018 s
->flags
&= ~DEBUG_METADATA_FLAGS
;
3020 if (!calculate_sizes(s
, -1))
3025 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
3026 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
3027 if (system_has_cmpxchg_double() && (s
->flags
& SLAB_DEBUG_FLAGS
) == 0)
3028 /* Enable fast mode */
3029 s
->flags
|= __CMPXCHG_DOUBLE
;
3033 * The larger the object size is, the more pages we want on the partial
3034 * list to avoid pounding the page allocator excessively.
3036 set_min_partial(s
, ilog2(s
->size
) / 2);
3039 * cpu_partial determined the maximum number of objects kept in the
3040 * per cpu partial lists of a processor.
3042 * Per cpu partial lists mainly contain slabs that just have one
3043 * object freed. If they are used for allocation then they can be
3044 * filled up again with minimal effort. The slab will never hit the
3045 * per node partial lists and therefore no locking will be required.
3047 * This setting also determines
3049 * A) The number of objects from per cpu partial slabs dumped to the
3050 * per node list when we reach the limit.
3051 * B) The number of objects in cpu partial slabs to extract from the
3052 * per node list when we run out of per cpu objects. We only fetch 50%
3053 * to keep some capacity around for frees.
3055 if (kmem_cache_debug(s
))
3057 else if (s
->size
>= PAGE_SIZE
)
3059 else if (s
->size
>= 1024)
3061 else if (s
->size
>= 256)
3062 s
->cpu_partial
= 13;
3064 s
->cpu_partial
= 30;
3067 s
->remote_node_defrag_ratio
= 1000;
3069 if (!init_kmem_cache_nodes(s
))
3072 if (alloc_kmem_cache_cpus(s
))
3075 free_kmem_cache_nodes(s
);
3077 if (flags
& SLAB_PANIC
)
3078 panic("Cannot create slab %s size=%lu realsize=%u "
3079 "order=%u offset=%u flags=%lx\n",
3080 s
->name
, (unsigned long)s
->size
, s
->size
, oo_order(s
->oo
),
3085 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
3088 #ifdef CONFIG_SLUB_DEBUG
3089 void *addr
= page_address(page
);
3091 unsigned long *map
= kzalloc(BITS_TO_LONGS(page
->objects
) *
3092 sizeof(long), GFP_ATOMIC
);
3095 slab_err(s
, page
, text
, s
->name
);
3098 get_map(s
, page
, map
);
3099 for_each_object(p
, s
, addr
, page
->objects
) {
3101 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
3102 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
3104 print_tracking(s
, p
);
3113 * Attempt to free all partial slabs on a node.
3114 * This is called from kmem_cache_close(). We must be the last thread
3115 * using the cache and therefore we do not need to lock anymore.
3117 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
3119 struct page
*page
, *h
;
3121 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
3123 remove_partial(n
, page
);
3124 discard_slab(s
, page
);
3126 list_slab_objects(s
, page
,
3127 "Objects remaining in %s on kmem_cache_close()");
3133 * Release all resources used by a slab cache.
3135 static inline int kmem_cache_close(struct kmem_cache
*s
)
3140 /* Attempt to free all objects */
3141 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3142 struct kmem_cache_node
*n
= get_node(s
, node
);
3145 if (n
->nr_partial
|| slabs_node(s
, node
))
3148 free_percpu(s
->cpu_slab
);
3149 free_kmem_cache_nodes(s
);
3153 int __kmem_cache_shutdown(struct kmem_cache
*s
)
3155 int rc
= kmem_cache_close(s
);
3158 sysfs_slab_remove(s
);
3163 /********************************************************************
3165 *******************************************************************/
3167 struct kmem_cache
*kmalloc_caches
[SLUB_PAGE_SHIFT
];
3168 EXPORT_SYMBOL(kmalloc_caches
);
3170 #ifdef CONFIG_ZONE_DMA
3171 static struct kmem_cache
*kmalloc_dma_caches
[SLUB_PAGE_SHIFT
];
3174 static int __init
setup_slub_min_order(char *str
)
3176 get_option(&str
, &slub_min_order
);
3181 __setup("slub_min_order=", setup_slub_min_order
);
3183 static int __init
setup_slub_max_order(char *str
)
3185 get_option(&str
, &slub_max_order
);
3186 slub_max_order
= min(slub_max_order
, MAX_ORDER
- 1);
3191 __setup("slub_max_order=", setup_slub_max_order
);
3193 static int __init
setup_slub_min_objects(char *str
)
3195 get_option(&str
, &slub_min_objects
);
3200 __setup("slub_min_objects=", setup_slub_min_objects
);
3202 static int __init
setup_slub_nomerge(char *str
)
3208 __setup("slub_nomerge", setup_slub_nomerge
);
3211 * Conversion table for small slabs sizes / 8 to the index in the
3212 * kmalloc array. This is necessary for slabs < 192 since we have non power
3213 * of two cache sizes there. The size of larger slabs can be determined using
3216 static s8 size_index
[24] = {
3243 static inline int size_index_elem(size_t bytes
)
3245 return (bytes
- 1) / 8;
3248 static struct kmem_cache
*get_slab(size_t size
, gfp_t flags
)
3254 return ZERO_SIZE_PTR
;
3256 index
= size_index
[size_index_elem(size
)];
3258 index
= fls(size
- 1);
3260 #ifdef CONFIG_ZONE_DMA
3261 if (unlikely((flags
& SLUB_DMA
)))
3262 return kmalloc_dma_caches
[index
];
3265 return kmalloc_caches
[index
];
3268 void *__kmalloc(size_t size
, gfp_t flags
)
3270 struct kmem_cache
*s
;
3273 if (unlikely(size
> SLUB_MAX_SIZE
))
3274 return kmalloc_large(size
, flags
);
3276 s
= get_slab(size
, flags
);
3278 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3281 ret
= slab_alloc(s
, flags
, _RET_IP_
);
3283 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, flags
);
3287 EXPORT_SYMBOL(__kmalloc
);
3290 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
3295 flags
|= __GFP_COMP
| __GFP_NOTRACK
;
3296 page
= alloc_pages_node(node
, flags
, get_order(size
));
3298 ptr
= page_address(page
);
3300 kmemleak_alloc(ptr
, size
, 1, flags
);
3304 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3306 struct kmem_cache
*s
;
3309 if (unlikely(size
> SLUB_MAX_SIZE
)) {
3310 ret
= kmalloc_large_node(size
, flags
, node
);
3312 trace_kmalloc_node(_RET_IP_
, ret
,
3313 size
, PAGE_SIZE
<< get_order(size
),
3319 s
= get_slab(size
, flags
);
3321 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3324 ret
= slab_alloc_node(s
, flags
, node
, _RET_IP_
);
3326 trace_kmalloc_node(_RET_IP_
, ret
, size
, s
->size
, flags
, node
);
3330 EXPORT_SYMBOL(__kmalloc_node
);
3333 size_t ksize(const void *object
)
3337 if (unlikely(object
== ZERO_SIZE_PTR
))
3340 page
= virt_to_head_page(object
);
3342 if (unlikely(!PageSlab(page
))) {
3343 WARN_ON(!PageCompound(page
));
3344 return PAGE_SIZE
<< compound_order(page
);
3347 return slab_ksize(page
->slab_cache
);
3349 EXPORT_SYMBOL(ksize
);
3351 #ifdef CONFIG_SLUB_DEBUG
3352 bool verify_mem_not_deleted(const void *x
)
3355 void *object
= (void *)x
;
3356 unsigned long flags
;
3359 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3362 local_irq_save(flags
);
3364 page
= virt_to_head_page(x
);
3365 if (unlikely(!PageSlab(page
))) {
3366 /* maybe it was from stack? */
3372 if (on_freelist(page
->slab_cache
, page
, object
)) {
3373 object_err(page
->slab_cache
, page
, object
, "Object is on free-list");
3381 local_irq_restore(flags
);
3384 EXPORT_SYMBOL(verify_mem_not_deleted
);
3387 void kfree(const void *x
)
3390 void *object
= (void *)x
;
3392 trace_kfree(_RET_IP_
, x
);
3394 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3397 page
= virt_to_head_page(x
);
3398 if (unlikely(!PageSlab(page
))) {
3399 BUG_ON(!PageCompound(page
));
3401 __free_pages(page
, compound_order(page
));
3404 slab_free(page
->slab_cache
, page
, object
, _RET_IP_
);
3406 EXPORT_SYMBOL(kfree
);
3409 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
3410 * the remaining slabs by the number of items in use. The slabs with the
3411 * most items in use come first. New allocations will then fill those up
3412 * and thus they can be removed from the partial lists.
3414 * The slabs with the least items are placed last. This results in them
3415 * being allocated from last increasing the chance that the last objects
3416 * are freed in them.
3418 int kmem_cache_shrink(struct kmem_cache
*s
)
3422 struct kmem_cache_node
*n
;
3425 int objects
= oo_objects(s
->max
);
3426 struct list_head
*slabs_by_inuse
=
3427 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
3428 unsigned long flags
;
3430 if (!slabs_by_inuse
)
3434 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3435 n
= get_node(s
, node
);
3440 for (i
= 0; i
< objects
; i
++)
3441 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
3443 spin_lock_irqsave(&n
->list_lock
, flags
);
3446 * Build lists indexed by the items in use in each slab.
3448 * Note that concurrent frees may occur while we hold the
3449 * list_lock. page->inuse here is the upper limit.
3451 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
3452 list_move(&page
->lru
, slabs_by_inuse
+ page
->inuse
);
3458 * Rebuild the partial list with the slabs filled up most
3459 * first and the least used slabs at the end.
3461 for (i
= objects
- 1; i
> 0; i
--)
3462 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
3464 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3466 /* Release empty slabs */
3467 list_for_each_entry_safe(page
, t
, slabs_by_inuse
, lru
)
3468 discard_slab(s
, page
);
3471 kfree(slabs_by_inuse
);
3474 EXPORT_SYMBOL(kmem_cache_shrink
);
3476 #if defined(CONFIG_MEMORY_HOTPLUG)
3477 static int slab_mem_going_offline_callback(void *arg
)
3479 struct kmem_cache
*s
;
3481 mutex_lock(&slab_mutex
);
3482 list_for_each_entry(s
, &slab_caches
, list
)
3483 kmem_cache_shrink(s
);
3484 mutex_unlock(&slab_mutex
);
3489 static void slab_mem_offline_callback(void *arg
)
3491 struct kmem_cache_node
*n
;
3492 struct kmem_cache
*s
;
3493 struct memory_notify
*marg
= arg
;
3496 offline_node
= marg
->status_change_nid_normal
;
3499 * If the node still has available memory. we need kmem_cache_node
3502 if (offline_node
< 0)
3505 mutex_lock(&slab_mutex
);
3506 list_for_each_entry(s
, &slab_caches
, list
) {
3507 n
= get_node(s
, offline_node
);
3510 * if n->nr_slabs > 0, slabs still exist on the node
3511 * that is going down. We were unable to free them,
3512 * and offline_pages() function shouldn't call this
3513 * callback. So, we must fail.
3515 BUG_ON(slabs_node(s
, offline_node
));
3517 s
->node
[offline_node
] = NULL
;
3518 kmem_cache_free(kmem_cache_node
, n
);
3521 mutex_unlock(&slab_mutex
);
3524 static int slab_mem_going_online_callback(void *arg
)
3526 struct kmem_cache_node
*n
;
3527 struct kmem_cache
*s
;
3528 struct memory_notify
*marg
= arg
;
3529 int nid
= marg
->status_change_nid_normal
;
3533 * If the node's memory is already available, then kmem_cache_node is
3534 * already created. Nothing to do.
3540 * We are bringing a node online. No memory is available yet. We must
3541 * allocate a kmem_cache_node structure in order to bring the node
3544 mutex_lock(&slab_mutex
);
3545 list_for_each_entry(s
, &slab_caches
, list
) {
3547 * XXX: kmem_cache_alloc_node will fallback to other nodes
3548 * since memory is not yet available from the node that
3551 n
= kmem_cache_alloc(kmem_cache_node
, GFP_KERNEL
);
3556 init_kmem_cache_node(n
);
3560 mutex_unlock(&slab_mutex
);
3564 static int slab_memory_callback(struct notifier_block
*self
,
3565 unsigned long action
, void *arg
)
3570 case MEM_GOING_ONLINE
:
3571 ret
= slab_mem_going_online_callback(arg
);
3573 case MEM_GOING_OFFLINE
:
3574 ret
= slab_mem_going_offline_callback(arg
);
3577 case MEM_CANCEL_ONLINE
:
3578 slab_mem_offline_callback(arg
);
3581 case MEM_CANCEL_OFFLINE
:
3585 ret
= notifier_from_errno(ret
);
3591 #endif /* CONFIG_MEMORY_HOTPLUG */
3593 /********************************************************************
3594 * Basic setup of slabs
3595 *******************************************************************/
3598 * Used for early kmem_cache structures that were allocated using
3599 * the page allocator. Allocate them properly then fix up the pointers
3600 * that may be pointing to the wrong kmem_cache structure.
3603 static struct kmem_cache
* __init
bootstrap(struct kmem_cache
*static_cache
)
3606 struct kmem_cache
*s
= kmem_cache_zalloc(kmem_cache
, GFP_NOWAIT
);
3608 memcpy(s
, static_cache
, kmem_cache
->object_size
);
3610 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3611 struct kmem_cache_node
*n
= get_node(s
, node
);
3615 list_for_each_entry(p
, &n
->partial
, lru
)
3618 #ifdef CONFIG_SLUB_DEBUG
3619 list_for_each_entry(p
, &n
->full
, lru
)
3624 list_add(&s
->list
, &slab_caches
);
3628 void __init
kmem_cache_init(void)
3630 static __initdata
struct kmem_cache boot_kmem_cache
,
3631 boot_kmem_cache_node
;
3635 if (debug_guardpage_minorder())
3638 kmem_cache_node
= &boot_kmem_cache_node
;
3639 kmem_cache
= &boot_kmem_cache
;
3641 create_boot_cache(kmem_cache_node
, "kmem_cache_node",
3642 sizeof(struct kmem_cache_node
), SLAB_HWCACHE_ALIGN
);
3644 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
3646 /* Able to allocate the per node structures */
3647 slab_state
= PARTIAL
;
3649 create_boot_cache(kmem_cache
, "kmem_cache",
3650 offsetof(struct kmem_cache
, node
) +
3651 nr_node_ids
* sizeof(struct kmem_cache_node
*),
3652 SLAB_HWCACHE_ALIGN
);
3654 kmem_cache
= bootstrap(&boot_kmem_cache
);
3657 * Allocate kmem_cache_node properly from the kmem_cache slab.
3658 * kmem_cache_node is separately allocated so no need to
3659 * update any list pointers.
3661 kmem_cache_node
= bootstrap(&boot_kmem_cache_node
);
3663 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3666 * Patch up the size_index table if we have strange large alignment
3667 * requirements for the kmalloc array. This is only the case for
3668 * MIPS it seems. The standard arches will not generate any code here.
3670 * Largest permitted alignment is 256 bytes due to the way we
3671 * handle the index determination for the smaller caches.
3673 * Make sure that nothing crazy happens if someone starts tinkering
3674 * around with ARCH_KMALLOC_MINALIGN
3676 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 256 ||
3677 (KMALLOC_MIN_SIZE
& (KMALLOC_MIN_SIZE
- 1)));
3679 for (i
= 8; i
< KMALLOC_MIN_SIZE
; i
+= 8) {
3680 int elem
= size_index_elem(i
);
3681 if (elem
>= ARRAY_SIZE(size_index
))
3683 size_index
[elem
] = KMALLOC_SHIFT_LOW
;
3686 if (KMALLOC_MIN_SIZE
== 64) {
3688 * The 96 byte size cache is not used if the alignment
3691 for (i
= 64 + 8; i
<= 96; i
+= 8)
3692 size_index
[size_index_elem(i
)] = 7;
3693 } else if (KMALLOC_MIN_SIZE
== 128) {
3695 * The 192 byte sized cache is not used if the alignment
3696 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3699 for (i
= 128 + 8; i
<= 192; i
+= 8)
3700 size_index
[size_index_elem(i
)] = 8;
3703 /* Caches that are not of the two-to-the-power-of size */
3704 if (KMALLOC_MIN_SIZE
<= 32) {
3705 kmalloc_caches
[1] = create_kmalloc_cache("kmalloc-96", 96, 0);
3709 if (KMALLOC_MIN_SIZE
<= 64) {
3710 kmalloc_caches
[2] = create_kmalloc_cache("kmalloc-192", 192, 0);
3714 for (i
= KMALLOC_SHIFT_LOW
; i
< SLUB_PAGE_SHIFT
; i
++) {
3715 kmalloc_caches
[i
] = create_kmalloc_cache("kmalloc", 1 << i
, 0);
3721 /* Provide the correct kmalloc names now that the caches are up */
3722 if (KMALLOC_MIN_SIZE
<= 32) {
3723 kmalloc_caches
[1]->name
= kstrdup(kmalloc_caches
[1]->name
, GFP_NOWAIT
);
3724 BUG_ON(!kmalloc_caches
[1]->name
);
3727 if (KMALLOC_MIN_SIZE
<= 64) {
3728 kmalloc_caches
[2]->name
= kstrdup(kmalloc_caches
[2]->name
, GFP_NOWAIT
);
3729 BUG_ON(!kmalloc_caches
[2]->name
);
3732 for (i
= KMALLOC_SHIFT_LOW
; i
< SLUB_PAGE_SHIFT
; i
++) {
3733 char *s
= kasprintf(GFP_NOWAIT
, "kmalloc-%d", 1 << i
);
3736 kmalloc_caches
[i
]->name
= s
;
3740 register_cpu_notifier(&slab_notifier
);
3743 #ifdef CONFIG_ZONE_DMA
3744 for (i
= 0; i
< SLUB_PAGE_SHIFT
; i
++) {
3745 struct kmem_cache
*s
= kmalloc_caches
[i
];
3748 char *name
= kasprintf(GFP_NOWAIT
,
3749 "dma-kmalloc-%d", s
->object_size
);
3752 kmalloc_dma_caches
[i
] = create_kmalloc_cache(name
,
3753 s
->object_size
, SLAB_CACHE_DMA
);
3758 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3759 " CPUs=%d, Nodes=%d\n",
3760 caches
, cache_line_size(),
3761 slub_min_order
, slub_max_order
, slub_min_objects
,
3762 nr_cpu_ids
, nr_node_ids
);
3765 void __init
kmem_cache_init_late(void)
3770 * Find a mergeable slab cache
3772 static int slab_unmergeable(struct kmem_cache
*s
)
3774 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3781 * We may have set a slab to be unmergeable during bootstrap.
3783 if (s
->refcount
< 0)
3789 static struct kmem_cache
*find_mergeable(size_t size
,
3790 size_t align
, unsigned long flags
, const char *name
,
3791 void (*ctor
)(void *))
3793 struct kmem_cache
*s
;
3795 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3801 size
= ALIGN(size
, sizeof(void *));
3802 align
= calculate_alignment(flags
, align
, size
);
3803 size
= ALIGN(size
, align
);
3804 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3806 list_for_each_entry(s
, &slab_caches
, list
) {
3807 if (slab_unmergeable(s
))
3813 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3816 * Check if alignment is compatible.
3817 * Courtesy of Adrian Drzewiecki
3819 if ((s
->size
& ~(align
- 1)) != s
->size
)
3822 if (s
->size
- size
>= sizeof(void *))
3830 struct kmem_cache
*__kmem_cache_alias(const char *name
, size_t size
,
3831 size_t align
, unsigned long flags
, void (*ctor
)(void *))
3833 struct kmem_cache
*s
;
3835 s
= find_mergeable(size
, align
, flags
, name
, ctor
);
3839 * Adjust the object sizes so that we clear
3840 * the complete object on kzalloc.
3842 s
->object_size
= max(s
->object_size
, (int)size
);
3843 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3845 if (sysfs_slab_alias(s
, name
)) {
3854 int __kmem_cache_create(struct kmem_cache
*s
, unsigned long flags
)
3858 err
= kmem_cache_open(s
, flags
);
3862 /* Mutex is not taken during early boot */
3863 if (slab_state
<= UP
)
3866 mutex_unlock(&slab_mutex
);
3867 err
= sysfs_slab_add(s
);
3868 mutex_lock(&slab_mutex
);
3871 kmem_cache_close(s
);
3878 * Use the cpu notifier to insure that the cpu slabs are flushed when
3881 static int __cpuinit
slab_cpuup_callback(struct notifier_block
*nfb
,
3882 unsigned long action
, void *hcpu
)
3884 long cpu
= (long)hcpu
;
3885 struct kmem_cache
*s
;
3886 unsigned long flags
;
3889 case CPU_UP_CANCELED
:
3890 case CPU_UP_CANCELED_FROZEN
:
3892 case CPU_DEAD_FROZEN
:
3893 mutex_lock(&slab_mutex
);
3894 list_for_each_entry(s
, &slab_caches
, list
) {
3895 local_irq_save(flags
);
3896 __flush_cpu_slab(s
, cpu
);
3897 local_irq_restore(flags
);
3899 mutex_unlock(&slab_mutex
);
3907 static struct notifier_block __cpuinitdata slab_notifier
= {
3908 .notifier_call
= slab_cpuup_callback
3913 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, unsigned long caller
)
3915 struct kmem_cache
*s
;
3918 if (unlikely(size
> SLUB_MAX_SIZE
))
3919 return kmalloc_large(size
, gfpflags
);
3921 s
= get_slab(size
, gfpflags
);
3923 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3926 ret
= slab_alloc(s
, gfpflags
, caller
);
3928 /* Honor the call site pointer we received. */
3929 trace_kmalloc(caller
, ret
, size
, s
->size
, gfpflags
);
3935 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3936 int node
, unsigned long caller
)
3938 struct kmem_cache
*s
;
3941 if (unlikely(size
> SLUB_MAX_SIZE
)) {
3942 ret
= kmalloc_large_node(size
, gfpflags
, node
);
3944 trace_kmalloc_node(caller
, ret
,
3945 size
, PAGE_SIZE
<< get_order(size
),
3951 s
= get_slab(size
, gfpflags
);
3953 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3956 ret
= slab_alloc_node(s
, gfpflags
, node
, caller
);
3958 /* Honor the call site pointer we received. */
3959 trace_kmalloc_node(caller
, ret
, size
, s
->size
, gfpflags
, node
);
3966 static int count_inuse(struct page
*page
)
3971 static int count_total(struct page
*page
)
3973 return page
->objects
;
3977 #ifdef CONFIG_SLUB_DEBUG
3978 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3982 void *addr
= page_address(page
);
3984 if (!check_slab(s
, page
) ||
3985 !on_freelist(s
, page
, NULL
))
3988 /* Now we know that a valid freelist exists */
3989 bitmap_zero(map
, page
->objects
);
3991 get_map(s
, page
, map
);
3992 for_each_object(p
, s
, addr
, page
->objects
) {
3993 if (test_bit(slab_index(p
, s
, addr
), map
))
3994 if (!check_object(s
, page
, p
, SLUB_RED_INACTIVE
))
3998 for_each_object(p
, s
, addr
, page
->objects
)
3999 if (!test_bit(slab_index(p
, s
, addr
), map
))
4000 if (!check_object(s
, page
, p
, SLUB_RED_ACTIVE
))
4005 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
4009 validate_slab(s
, page
, map
);
4013 static int validate_slab_node(struct kmem_cache
*s
,
4014 struct kmem_cache_node
*n
, unsigned long *map
)
4016 unsigned long count
= 0;
4018 unsigned long flags
;
4020 spin_lock_irqsave(&n
->list_lock
, flags
);
4022 list_for_each_entry(page
, &n
->partial
, lru
) {
4023 validate_slab_slab(s
, page
, map
);
4026 if (count
!= n
->nr_partial
)
4027 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
4028 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
4030 if (!(s
->flags
& SLAB_STORE_USER
))
4033 list_for_each_entry(page
, &n
->full
, lru
) {
4034 validate_slab_slab(s
, page
, map
);
4037 if (count
!= atomic_long_read(&n
->nr_slabs
))
4038 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
4039 "counter=%ld\n", s
->name
, count
,
4040 atomic_long_read(&n
->nr_slabs
));
4043 spin_unlock_irqrestore(&n
->list_lock
, flags
);
4047 static long validate_slab_cache(struct kmem_cache
*s
)
4050 unsigned long count
= 0;
4051 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
4052 sizeof(unsigned long), GFP_KERNEL
);
4058 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4059 struct kmem_cache_node
*n
= get_node(s
, node
);
4061 count
+= validate_slab_node(s
, n
, map
);
4067 * Generate lists of code addresses where slabcache objects are allocated
4072 unsigned long count
;
4079 DECLARE_BITMAP(cpus
, NR_CPUS
);
4085 unsigned long count
;
4086 struct location
*loc
;
4089 static void free_loc_track(struct loc_track
*t
)
4092 free_pages((unsigned long)t
->loc
,
4093 get_order(sizeof(struct location
) * t
->max
));
4096 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
4101 order
= get_order(sizeof(struct location
) * max
);
4103 l
= (void *)__get_free_pages(flags
, order
);
4108 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
4116 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
4117 const struct track
*track
)
4119 long start
, end
, pos
;
4121 unsigned long caddr
;
4122 unsigned long age
= jiffies
- track
->when
;
4128 pos
= start
+ (end
- start
+ 1) / 2;
4131 * There is nothing at "end". If we end up there
4132 * we need to add something to before end.
4137 caddr
= t
->loc
[pos
].addr
;
4138 if (track
->addr
== caddr
) {
4144 if (age
< l
->min_time
)
4146 if (age
> l
->max_time
)
4149 if (track
->pid
< l
->min_pid
)
4150 l
->min_pid
= track
->pid
;
4151 if (track
->pid
> l
->max_pid
)
4152 l
->max_pid
= track
->pid
;
4154 cpumask_set_cpu(track
->cpu
,
4155 to_cpumask(l
->cpus
));
4157 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4161 if (track
->addr
< caddr
)
4168 * Not found. Insert new tracking element.
4170 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
4176 (t
->count
- pos
) * sizeof(struct location
));
4179 l
->addr
= track
->addr
;
4183 l
->min_pid
= track
->pid
;
4184 l
->max_pid
= track
->pid
;
4185 cpumask_clear(to_cpumask(l
->cpus
));
4186 cpumask_set_cpu(track
->cpu
, to_cpumask(l
->cpus
));
4187 nodes_clear(l
->nodes
);
4188 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4192 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
4193 struct page
*page
, enum track_item alloc
,
4196 void *addr
= page_address(page
);
4199 bitmap_zero(map
, page
->objects
);
4200 get_map(s
, page
, map
);
4202 for_each_object(p
, s
, addr
, page
->objects
)
4203 if (!test_bit(slab_index(p
, s
, addr
), map
))
4204 add_location(t
, s
, get_track(s
, p
, alloc
));
4207 static int list_locations(struct kmem_cache
*s
, char *buf
,
4208 enum track_item alloc
)
4212 struct loc_track t
= { 0, 0, NULL
};
4214 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
4215 sizeof(unsigned long), GFP_KERNEL
);
4217 if (!map
|| !alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
4220 return sprintf(buf
, "Out of memory\n");
4222 /* Push back cpu slabs */
4225 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4226 struct kmem_cache_node
*n
= get_node(s
, node
);
4227 unsigned long flags
;
4230 if (!atomic_long_read(&n
->nr_slabs
))
4233 spin_lock_irqsave(&n
->list_lock
, flags
);
4234 list_for_each_entry(page
, &n
->partial
, lru
)
4235 process_slab(&t
, s
, page
, alloc
, map
);
4236 list_for_each_entry(page
, &n
->full
, lru
)
4237 process_slab(&t
, s
, page
, alloc
, map
);
4238 spin_unlock_irqrestore(&n
->list_lock
, flags
);
4241 for (i
= 0; i
< t
.count
; i
++) {
4242 struct location
*l
= &t
.loc
[i
];
4244 if (len
> PAGE_SIZE
- KSYM_SYMBOL_LEN
- 100)
4246 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
4249 len
+= sprintf(buf
+ len
, "%pS", (void *)l
->addr
);
4251 len
+= sprintf(buf
+ len
, "<not-available>");
4253 if (l
->sum_time
!= l
->min_time
) {
4254 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
4256 (long)div_u64(l
->sum_time
, l
->count
),
4259 len
+= sprintf(buf
+ len
, " age=%ld",
4262 if (l
->min_pid
!= l
->max_pid
)
4263 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
4264 l
->min_pid
, l
->max_pid
);
4266 len
+= sprintf(buf
+ len
, " pid=%ld",
4269 if (num_online_cpus() > 1 &&
4270 !cpumask_empty(to_cpumask(l
->cpus
)) &&
4271 len
< PAGE_SIZE
- 60) {
4272 len
+= sprintf(buf
+ len
, " cpus=");
4273 len
+= cpulist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
4274 to_cpumask(l
->cpus
));
4277 if (nr_online_nodes
> 1 && !nodes_empty(l
->nodes
) &&
4278 len
< PAGE_SIZE
- 60) {
4279 len
+= sprintf(buf
+ len
, " nodes=");
4280 len
+= nodelist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
4284 len
+= sprintf(buf
+ len
, "\n");
4290 len
+= sprintf(buf
, "No data\n");
4295 #ifdef SLUB_RESILIENCY_TEST
4296 static void resiliency_test(void)
4300 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 16 || SLUB_PAGE_SHIFT
< 10);
4302 printk(KERN_ERR
"SLUB resiliency testing\n");
4303 printk(KERN_ERR
"-----------------------\n");
4304 printk(KERN_ERR
"A. Corruption after allocation\n");
4306 p
= kzalloc(16, GFP_KERNEL
);
4308 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
4309 " 0x12->0x%p\n\n", p
+ 16);
4311 validate_slab_cache(kmalloc_caches
[4]);
4313 /* Hmmm... The next two are dangerous */
4314 p
= kzalloc(32, GFP_KERNEL
);
4315 p
[32 + sizeof(void *)] = 0x34;
4316 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
4317 " 0x34 -> -0x%p\n", p
);
4319 "If allocated object is overwritten then not detectable\n\n");
4321 validate_slab_cache(kmalloc_caches
[5]);
4322 p
= kzalloc(64, GFP_KERNEL
);
4323 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
4325 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
4328 "If allocated object is overwritten then not detectable\n\n");
4329 validate_slab_cache(kmalloc_caches
[6]);
4331 printk(KERN_ERR
"\nB. Corruption after free\n");
4332 p
= kzalloc(128, GFP_KERNEL
);
4335 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
4336 validate_slab_cache(kmalloc_caches
[7]);
4338 p
= kzalloc(256, GFP_KERNEL
);
4341 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
4343 validate_slab_cache(kmalloc_caches
[8]);
4345 p
= kzalloc(512, GFP_KERNEL
);
4348 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
4349 validate_slab_cache(kmalloc_caches
[9]);
4353 static void resiliency_test(void) {};
4358 enum slab_stat_type
{
4359 SL_ALL
, /* All slabs */
4360 SL_PARTIAL
, /* Only partially allocated slabs */
4361 SL_CPU
, /* Only slabs used for cpu caches */
4362 SL_OBJECTS
, /* Determine allocated objects not slabs */
4363 SL_TOTAL
/* Determine object capacity not slabs */
4366 #define SO_ALL (1 << SL_ALL)
4367 #define SO_PARTIAL (1 << SL_PARTIAL)
4368 #define SO_CPU (1 << SL_CPU)
4369 #define SO_OBJECTS (1 << SL_OBJECTS)
4370 #define SO_TOTAL (1 << SL_TOTAL)
4372 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
4373 char *buf
, unsigned long flags
)
4375 unsigned long total
= 0;
4378 unsigned long *nodes
;
4379 unsigned long *per_cpu
;
4381 nodes
= kzalloc(2 * sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
4384 per_cpu
= nodes
+ nr_node_ids
;
4386 if (flags
& SO_CPU
) {
4389 for_each_possible_cpu(cpu
) {
4390 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
4394 page
= ACCESS_ONCE(c
->page
);
4398 node
= page_to_nid(page
);
4399 if (flags
& SO_TOTAL
)
4401 else if (flags
& SO_OBJECTS
)
4409 page
= ACCESS_ONCE(c
->partial
);
4420 lock_memory_hotplug();
4421 #ifdef CONFIG_SLUB_DEBUG
4422 if (flags
& SO_ALL
) {
4423 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4424 struct kmem_cache_node
*n
= get_node(s
, node
);
4426 if (flags
& SO_TOTAL
)
4427 x
= atomic_long_read(&n
->total_objects
);
4428 else if (flags
& SO_OBJECTS
)
4429 x
= atomic_long_read(&n
->total_objects
) -
4430 count_partial(n
, count_free
);
4433 x
= atomic_long_read(&n
->nr_slabs
);
4440 if (flags
& SO_PARTIAL
) {
4441 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4442 struct kmem_cache_node
*n
= get_node(s
, node
);
4444 if (flags
& SO_TOTAL
)
4445 x
= count_partial(n
, count_total
);
4446 else if (flags
& SO_OBJECTS
)
4447 x
= count_partial(n
, count_inuse
);
4454 x
= sprintf(buf
, "%lu", total
);
4456 for_each_node_state(node
, N_NORMAL_MEMORY
)
4458 x
+= sprintf(buf
+ x
, " N%d=%lu",
4461 unlock_memory_hotplug();
4463 return x
+ sprintf(buf
+ x
, "\n");
4466 #ifdef CONFIG_SLUB_DEBUG
4467 static int any_slab_objects(struct kmem_cache
*s
)
4471 for_each_online_node(node
) {
4472 struct kmem_cache_node
*n
= get_node(s
, node
);
4477 if (atomic_long_read(&n
->total_objects
))
4484 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4485 #define to_slab(n) container_of(n, struct kmem_cache, kobj)
4487 struct slab_attribute
{
4488 struct attribute attr
;
4489 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
4490 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
4493 #define SLAB_ATTR_RO(_name) \
4494 static struct slab_attribute _name##_attr = \
4495 __ATTR(_name, 0400, _name##_show, NULL)
4497 #define SLAB_ATTR(_name) \
4498 static struct slab_attribute _name##_attr = \
4499 __ATTR(_name, 0600, _name##_show, _name##_store)
4501 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
4503 return sprintf(buf
, "%d\n", s
->size
);
4505 SLAB_ATTR_RO(slab_size
);
4507 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
4509 return sprintf(buf
, "%d\n", s
->align
);
4511 SLAB_ATTR_RO(align
);
4513 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
4515 return sprintf(buf
, "%d\n", s
->object_size
);
4517 SLAB_ATTR_RO(object_size
);
4519 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
4521 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
4523 SLAB_ATTR_RO(objs_per_slab
);
4525 static ssize_t
order_store(struct kmem_cache
*s
,
4526 const char *buf
, size_t length
)
4528 unsigned long order
;
4531 err
= strict_strtoul(buf
, 10, &order
);
4535 if (order
> slub_max_order
|| order
< slub_min_order
)
4538 calculate_sizes(s
, order
);
4542 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
4544 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
4548 static ssize_t
min_partial_show(struct kmem_cache
*s
, char *buf
)
4550 return sprintf(buf
, "%lu\n", s
->min_partial
);
4553 static ssize_t
min_partial_store(struct kmem_cache
*s
, const char *buf
,
4559 err
= strict_strtoul(buf
, 10, &min
);
4563 set_min_partial(s
, min
);
4566 SLAB_ATTR(min_partial
);
4568 static ssize_t
cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4570 return sprintf(buf
, "%u\n", s
->cpu_partial
);
4573 static ssize_t
cpu_partial_store(struct kmem_cache
*s
, const char *buf
,
4576 unsigned long objects
;
4579 err
= strict_strtoul(buf
, 10, &objects
);
4582 if (objects
&& kmem_cache_debug(s
))
4585 s
->cpu_partial
= objects
;
4589 SLAB_ATTR(cpu_partial
);
4591 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
4595 return sprintf(buf
, "%pS\n", s
->ctor
);
4599 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
4601 return sprintf(buf
, "%d\n", s
->refcount
- 1);
4603 SLAB_ATTR_RO(aliases
);
4605 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
4607 return show_slab_objects(s
, buf
, SO_PARTIAL
);
4609 SLAB_ATTR_RO(partial
);
4611 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
4613 return show_slab_objects(s
, buf
, SO_CPU
);
4615 SLAB_ATTR_RO(cpu_slabs
);
4617 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
4619 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
4621 SLAB_ATTR_RO(objects
);
4623 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
4625 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
4627 SLAB_ATTR_RO(objects_partial
);
4629 static ssize_t
slabs_cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4636 for_each_online_cpu(cpu
) {
4637 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
)->partial
;
4640 pages
+= page
->pages
;
4641 objects
+= page
->pobjects
;
4645 len
= sprintf(buf
, "%d(%d)", objects
, pages
);
4648 for_each_online_cpu(cpu
) {
4649 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
) ->partial
;
4651 if (page
&& len
< PAGE_SIZE
- 20)
4652 len
+= sprintf(buf
+ len
, " C%d=%d(%d)", cpu
,
4653 page
->pobjects
, page
->pages
);
4656 return len
+ sprintf(buf
+ len
, "\n");
4658 SLAB_ATTR_RO(slabs_cpu_partial
);
4660 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
4662 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
4665 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
4666 const char *buf
, size_t length
)
4668 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
4670 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
4673 SLAB_ATTR(reclaim_account
);
4675 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
4677 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
4679 SLAB_ATTR_RO(hwcache_align
);
4681 #ifdef CONFIG_ZONE_DMA
4682 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
4684 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
4686 SLAB_ATTR_RO(cache_dma
);
4689 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
4691 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
4693 SLAB_ATTR_RO(destroy_by_rcu
);
4695 static ssize_t
reserved_show(struct kmem_cache
*s
, char *buf
)
4697 return sprintf(buf
, "%d\n", s
->reserved
);
4699 SLAB_ATTR_RO(reserved
);
4701 #ifdef CONFIG_SLUB_DEBUG
4702 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
4704 return show_slab_objects(s
, buf
, SO_ALL
);
4706 SLAB_ATTR_RO(slabs
);
4708 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
4710 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
4712 SLAB_ATTR_RO(total_objects
);
4714 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
4716 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
4719 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
4720 const char *buf
, size_t length
)
4722 s
->flags
&= ~SLAB_DEBUG_FREE
;
4723 if (buf
[0] == '1') {
4724 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4725 s
->flags
|= SLAB_DEBUG_FREE
;
4729 SLAB_ATTR(sanity_checks
);
4731 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
4733 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
4736 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
4739 s
->flags
&= ~SLAB_TRACE
;
4740 if (buf
[0] == '1') {
4741 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4742 s
->flags
|= SLAB_TRACE
;
4748 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
4750 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
4753 static ssize_t
red_zone_store(struct kmem_cache
*s
,
4754 const char *buf
, size_t length
)
4756 if (any_slab_objects(s
))
4759 s
->flags
&= ~SLAB_RED_ZONE
;
4760 if (buf
[0] == '1') {
4761 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4762 s
->flags
|= SLAB_RED_ZONE
;
4764 calculate_sizes(s
, -1);
4767 SLAB_ATTR(red_zone
);
4769 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
4771 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
4774 static ssize_t
poison_store(struct kmem_cache
*s
,
4775 const char *buf
, size_t length
)
4777 if (any_slab_objects(s
))
4780 s
->flags
&= ~SLAB_POISON
;
4781 if (buf
[0] == '1') {
4782 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4783 s
->flags
|= SLAB_POISON
;
4785 calculate_sizes(s
, -1);
4790 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4792 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4795 static ssize_t
store_user_store(struct kmem_cache
*s
,
4796 const char *buf
, size_t length
)
4798 if (any_slab_objects(s
))
4801 s
->flags
&= ~SLAB_STORE_USER
;
4802 if (buf
[0] == '1') {
4803 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4804 s
->flags
|= SLAB_STORE_USER
;
4806 calculate_sizes(s
, -1);
4809 SLAB_ATTR(store_user
);
4811 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4816 static ssize_t
validate_store(struct kmem_cache
*s
,
4817 const char *buf
, size_t length
)
4821 if (buf
[0] == '1') {
4822 ret
= validate_slab_cache(s
);
4828 SLAB_ATTR(validate
);
4830 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4832 if (!(s
->flags
& SLAB_STORE_USER
))
4834 return list_locations(s
, buf
, TRACK_ALLOC
);
4836 SLAB_ATTR_RO(alloc_calls
);
4838 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4840 if (!(s
->flags
& SLAB_STORE_USER
))
4842 return list_locations(s
, buf
, TRACK_FREE
);
4844 SLAB_ATTR_RO(free_calls
);
4845 #endif /* CONFIG_SLUB_DEBUG */
4847 #ifdef CONFIG_FAILSLAB
4848 static ssize_t
failslab_show(struct kmem_cache
*s
, char *buf
)
4850 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_FAILSLAB
));
4853 static ssize_t
failslab_store(struct kmem_cache
*s
, const char *buf
,
4856 s
->flags
&= ~SLAB_FAILSLAB
;
4858 s
->flags
|= SLAB_FAILSLAB
;
4861 SLAB_ATTR(failslab
);
4864 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4869 static ssize_t
shrink_store(struct kmem_cache
*s
,
4870 const char *buf
, size_t length
)
4872 if (buf
[0] == '1') {
4873 int rc
= kmem_cache_shrink(s
);
4884 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4886 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4889 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4890 const char *buf
, size_t length
)
4892 unsigned long ratio
;
4895 err
= strict_strtoul(buf
, 10, &ratio
);
4900 s
->remote_node_defrag_ratio
= ratio
* 10;
4904 SLAB_ATTR(remote_node_defrag_ratio
);
4907 #ifdef CONFIG_SLUB_STATS
4908 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4910 unsigned long sum
= 0;
4913 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4918 for_each_online_cpu(cpu
) {
4919 unsigned x
= per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
];
4925 len
= sprintf(buf
, "%lu", sum
);
4928 for_each_online_cpu(cpu
) {
4929 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4930 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4934 return len
+ sprintf(buf
+ len
, "\n");
4937 static void clear_stat(struct kmem_cache
*s
, enum stat_item si
)
4941 for_each_online_cpu(cpu
)
4942 per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
] = 0;
4945 #define STAT_ATTR(si, text) \
4946 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4948 return show_stat(s, buf, si); \
4950 static ssize_t text##_store(struct kmem_cache *s, \
4951 const char *buf, size_t length) \
4953 if (buf[0] != '0') \
4955 clear_stat(s, si); \
4960 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4961 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4962 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4963 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4964 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4965 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4966 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4967 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4968 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4969 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4970 STAT_ATTR(ALLOC_NODE_MISMATCH
, alloc_node_mismatch
);
4971 STAT_ATTR(FREE_SLAB
, free_slab
);
4972 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4973 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4974 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4975 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4976 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4977 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4978 STAT_ATTR(DEACTIVATE_BYPASS
, deactivate_bypass
);
4979 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4980 STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL
, cmpxchg_double_cpu_fail
);
4981 STAT_ATTR(CMPXCHG_DOUBLE_FAIL
, cmpxchg_double_fail
);
4982 STAT_ATTR(CPU_PARTIAL_ALLOC
, cpu_partial_alloc
);
4983 STAT_ATTR(CPU_PARTIAL_FREE
, cpu_partial_free
);
4984 STAT_ATTR(CPU_PARTIAL_NODE
, cpu_partial_node
);
4985 STAT_ATTR(CPU_PARTIAL_DRAIN
, cpu_partial_drain
);
4988 static struct attribute
*slab_attrs
[] = {
4989 &slab_size_attr
.attr
,
4990 &object_size_attr
.attr
,
4991 &objs_per_slab_attr
.attr
,
4993 &min_partial_attr
.attr
,
4994 &cpu_partial_attr
.attr
,
4996 &objects_partial_attr
.attr
,
4998 &cpu_slabs_attr
.attr
,
5002 &hwcache_align_attr
.attr
,
5003 &reclaim_account_attr
.attr
,
5004 &destroy_by_rcu_attr
.attr
,
5006 &reserved_attr
.attr
,
5007 &slabs_cpu_partial_attr
.attr
,
5008 #ifdef CONFIG_SLUB_DEBUG
5009 &total_objects_attr
.attr
,
5011 &sanity_checks_attr
.attr
,
5013 &red_zone_attr
.attr
,
5015 &store_user_attr
.attr
,
5016 &validate_attr
.attr
,
5017 &alloc_calls_attr
.attr
,
5018 &free_calls_attr
.attr
,
5020 #ifdef CONFIG_ZONE_DMA
5021 &cache_dma_attr
.attr
,
5024 &remote_node_defrag_ratio_attr
.attr
,
5026 #ifdef CONFIG_SLUB_STATS
5027 &alloc_fastpath_attr
.attr
,
5028 &alloc_slowpath_attr
.attr
,
5029 &free_fastpath_attr
.attr
,
5030 &free_slowpath_attr
.attr
,
5031 &free_frozen_attr
.attr
,
5032 &free_add_partial_attr
.attr
,
5033 &free_remove_partial_attr
.attr
,
5034 &alloc_from_partial_attr
.attr
,
5035 &alloc_slab_attr
.attr
,
5036 &alloc_refill_attr
.attr
,
5037 &alloc_node_mismatch_attr
.attr
,
5038 &free_slab_attr
.attr
,
5039 &cpuslab_flush_attr
.attr
,
5040 &deactivate_full_attr
.attr
,
5041 &deactivate_empty_attr
.attr
,
5042 &deactivate_to_head_attr
.attr
,
5043 &deactivate_to_tail_attr
.attr
,
5044 &deactivate_remote_frees_attr
.attr
,
5045 &deactivate_bypass_attr
.attr
,
5046 &order_fallback_attr
.attr
,
5047 &cmpxchg_double_fail_attr
.attr
,
5048 &cmpxchg_double_cpu_fail_attr
.attr
,
5049 &cpu_partial_alloc_attr
.attr
,
5050 &cpu_partial_free_attr
.attr
,
5051 &cpu_partial_node_attr
.attr
,
5052 &cpu_partial_drain_attr
.attr
,
5054 #ifdef CONFIG_FAILSLAB
5055 &failslab_attr
.attr
,
5061 static struct attribute_group slab_attr_group
= {
5062 .attrs
= slab_attrs
,
5065 static ssize_t
slab_attr_show(struct kobject
*kobj
,
5066 struct attribute
*attr
,
5069 struct slab_attribute
*attribute
;
5070 struct kmem_cache
*s
;
5073 attribute
= to_slab_attr(attr
);
5076 if (!attribute
->show
)
5079 err
= attribute
->show(s
, buf
);
5084 static ssize_t
slab_attr_store(struct kobject
*kobj
,
5085 struct attribute
*attr
,
5086 const char *buf
, size_t len
)
5088 struct slab_attribute
*attribute
;
5089 struct kmem_cache
*s
;
5092 attribute
= to_slab_attr(attr
);
5095 if (!attribute
->store
)
5098 err
= attribute
->store(s
, buf
, len
);
5103 static const struct sysfs_ops slab_sysfs_ops
= {
5104 .show
= slab_attr_show
,
5105 .store
= slab_attr_store
,
5108 static struct kobj_type slab_ktype
= {
5109 .sysfs_ops
= &slab_sysfs_ops
,
5112 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
5114 struct kobj_type
*ktype
= get_ktype(kobj
);
5116 if (ktype
== &slab_ktype
)
5121 static const struct kset_uevent_ops slab_uevent_ops
= {
5122 .filter
= uevent_filter
,
5125 static struct kset
*slab_kset
;
5127 #define ID_STR_LENGTH 64
5129 /* Create a unique string id for a slab cache:
5131 * Format :[flags-]size
5133 static char *create_unique_id(struct kmem_cache
*s
)
5135 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
5142 * First flags affecting slabcache operations. We will only
5143 * get here for aliasable slabs so we do not need to support
5144 * too many flags. The flags here must cover all flags that
5145 * are matched during merging to guarantee that the id is
5148 if (s
->flags
& SLAB_CACHE_DMA
)
5150 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
5152 if (s
->flags
& SLAB_DEBUG_FREE
)
5154 if (!(s
->flags
& SLAB_NOTRACK
))
5158 p
+= sprintf(p
, "%07d", s
->size
);
5159 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
5163 static int sysfs_slab_add(struct kmem_cache
*s
)
5167 int unmergeable
= slab_unmergeable(s
);
5171 * Slabcache can never be merged so we can use the name proper.
5172 * This is typically the case for debug situations. In that
5173 * case we can catch duplicate names easily.
5175 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
5179 * Create a unique name for the slab as a target
5182 name
= create_unique_id(s
);
5185 s
->kobj
.kset
= slab_kset
;
5186 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, name
);
5188 kobject_put(&s
->kobj
);
5192 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
5194 kobject_del(&s
->kobj
);
5195 kobject_put(&s
->kobj
);
5198 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
5200 /* Setup first alias */
5201 sysfs_slab_alias(s
, s
->name
);
5207 static void sysfs_slab_remove(struct kmem_cache
*s
)
5209 if (slab_state
< FULL
)
5211 * Sysfs has not been setup yet so no need to remove the
5216 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
5217 kobject_del(&s
->kobj
);
5218 kobject_put(&s
->kobj
);
5222 * Need to buffer aliases during bootup until sysfs becomes
5223 * available lest we lose that information.
5225 struct saved_alias
{
5226 struct kmem_cache
*s
;
5228 struct saved_alias
*next
;
5231 static struct saved_alias
*alias_list
;
5233 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
5235 struct saved_alias
*al
;
5237 if (slab_state
== FULL
) {
5239 * If we have a leftover link then remove it.
5241 sysfs_remove_link(&slab_kset
->kobj
, name
);
5242 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
5245 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
5251 al
->next
= alias_list
;
5256 static int __init
slab_sysfs_init(void)
5258 struct kmem_cache
*s
;
5261 mutex_lock(&slab_mutex
);
5263 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
5265 mutex_unlock(&slab_mutex
);
5266 printk(KERN_ERR
"Cannot register slab subsystem.\n");
5272 list_for_each_entry(s
, &slab_caches
, list
) {
5273 err
= sysfs_slab_add(s
);
5275 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
5276 " to sysfs\n", s
->name
);
5279 while (alias_list
) {
5280 struct saved_alias
*al
= alias_list
;
5282 alias_list
= alias_list
->next
;
5283 err
= sysfs_slab_alias(al
->s
, al
->name
);
5285 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
5286 " %s to sysfs\n", al
->name
);
5290 mutex_unlock(&slab_mutex
);
5295 __initcall(slab_sysfs_init
);
5296 #endif /* CONFIG_SYSFS */
5299 * The /proc/slabinfo ABI
5301 #ifdef CONFIG_SLABINFO
5302 void get_slabinfo(struct kmem_cache
*s
, struct slabinfo
*sinfo
)
5304 unsigned long nr_partials
= 0;
5305 unsigned long nr_slabs
= 0;
5306 unsigned long nr_objs
= 0;
5307 unsigned long nr_free
= 0;
5310 for_each_online_node(node
) {
5311 struct kmem_cache_node
*n
= get_node(s
, node
);
5316 nr_partials
+= n
->nr_partial
;
5317 nr_slabs
+= atomic_long_read(&n
->nr_slabs
);
5318 nr_objs
+= atomic_long_read(&n
->total_objects
);
5319 nr_free
+= count_partial(n
, count_free
);
5322 sinfo
->active_objs
= nr_objs
- nr_free
;
5323 sinfo
->num_objs
= nr_objs
;
5324 sinfo
->active_slabs
= nr_slabs
;
5325 sinfo
->num_slabs
= nr_slabs
;
5326 sinfo
->objects_per_slab
= oo_objects(s
->oo
);
5327 sinfo
->cache_order
= oo_order(s
->oo
);
5330 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*s
)
5334 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
5335 size_t count
, loff_t
*ppos
)
5339 #endif /* CONFIG_SLABINFO */