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 and only
6 * uses a centralized lock to manage a pool of partial slabs.
8 * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
12 #include <linux/module.h>
13 #include <linux/bit_spinlock.h>
14 #include <linux/interrupt.h>
15 #include <linux/bitops.h>
16 #include <linux/slab.h>
17 #include <linux/seq_file.h>
18 #include <linux/cpu.h>
19 #include <linux/cpuset.h>
20 #include <linux/mempolicy.h>
21 #include <linux/ctype.h>
22 #include <linux/kallsyms.h>
23 #include <linux/memory.h>
30 * The slab_lock protects operations on the object of a particular
31 * slab and its metadata in the page struct. If the slab lock
32 * has been taken then no allocations nor frees can be performed
33 * on the objects in the slab nor can the slab be added or removed
34 * from the partial or full lists since this would mean modifying
35 * the page_struct of the slab.
37 * The list_lock protects the partial and full list on each node and
38 * the partial slab counter. If taken then no new slabs may be added or
39 * removed from the lists nor make the number of partial slabs be modified.
40 * (Note that the total number of slabs is an atomic value that may be
41 * modified without taking the list lock).
43 * The list_lock is a centralized lock and thus we avoid taking it as
44 * much as possible. As long as SLUB does not have to handle partial
45 * slabs, operations can continue without any centralized lock. F.e.
46 * allocating a long series of objects that fill up slabs does not require
49 * The lock order is sometimes inverted when we are trying to get a slab
50 * off a list. We take the list_lock and then look for a page on the list
51 * to use. While we do that objects in the slabs may be freed. We can
52 * only operate on the slab if we have also taken the slab_lock. So we use
53 * a slab_trylock() on the slab. If trylock was successful then no frees
54 * can occur anymore and we can use the slab for allocations etc. If the
55 * slab_trylock() does not succeed then frees are in progress in the slab and
56 * we must stay away from it for a while since we may cause a bouncing
57 * cacheline if we try to acquire the lock. So go onto the next slab.
58 * If all pages are busy then we may allocate a new slab instead of reusing
59 * a partial slab. A new slab has noone operating on it and thus there is
60 * no danger of cacheline contention.
62 * Interrupts are disabled during allocation and deallocation in order to
63 * make the slab allocator safe to use in the context of an irq. In addition
64 * interrupts are disabled to ensure that the processor does not change
65 * while handling per_cpu slabs, due to kernel preemption.
67 * SLUB assigns one slab for allocation to each processor.
68 * Allocations only occur from these slabs called cpu slabs.
70 * Slabs with free elements are kept on a partial list and during regular
71 * operations no list for full slabs is used. If an object in a full slab is
72 * freed then the slab will show up again on the partial lists.
73 * We track full slabs for debugging purposes though because otherwise we
74 * cannot scan all objects.
76 * Slabs are freed when they become empty. Teardown and setup is
77 * minimal so we rely on the page allocators per cpu caches for
78 * fast frees and allocs.
80 * Overloading of page flags that are otherwise used for LRU management.
82 * PageActive The slab is frozen and exempt from list processing.
83 * This means that the slab is dedicated to a purpose
84 * such as satisfying allocations for a specific
85 * processor. Objects may be freed in the slab while
86 * it is frozen but slab_free will then skip the usual
87 * list operations. It is up to the processor holding
88 * the slab to integrate the slab into the slab lists
89 * when the slab is no longer needed.
91 * One use of this flag is to mark slabs that are
92 * used for allocations. Then such a slab becomes a cpu
93 * slab. The cpu slab may be equipped with an additional
94 * freelist that allows lockless access to
95 * free objects in addition to the regular freelist
96 * that requires the slab lock.
98 * PageError Slab requires special handling due to debug
99 * options set. This moves slab handling out of
100 * the fast path and disables lockless freelists.
103 #define FROZEN (1 << PG_active)
105 #ifdef CONFIG_SLUB_DEBUG
106 #define SLABDEBUG (1 << PG_error)
111 static inline int SlabFrozen(struct page
*page
)
113 return page
->flags
& FROZEN
;
116 static inline void SetSlabFrozen(struct page
*page
)
118 page
->flags
|= FROZEN
;
121 static inline void ClearSlabFrozen(struct page
*page
)
123 page
->flags
&= ~FROZEN
;
126 static inline int SlabDebug(struct page
*page
)
128 return page
->flags
& SLABDEBUG
;
131 static inline void SetSlabDebug(struct page
*page
)
133 page
->flags
|= SLABDEBUG
;
136 static inline void ClearSlabDebug(struct page
*page
)
138 page
->flags
&= ~SLABDEBUG
;
142 * Issues still to be resolved:
144 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
146 * - Variable sizing of the per node arrays
149 /* Enable to test recovery from slab corruption on boot */
150 #undef SLUB_RESILIENCY_TEST
155 * Small page size. Make sure that we do not fragment memory
157 #define DEFAULT_MAX_ORDER 1
158 #define DEFAULT_MIN_OBJECTS 4
163 * Large page machines are customarily able to handle larger
166 #define DEFAULT_MAX_ORDER 2
167 #define DEFAULT_MIN_OBJECTS 8
172 * Mininum number of partial slabs. These will be left on the partial
173 * lists even if they are empty. kmem_cache_shrink may reclaim them.
175 #define MIN_PARTIAL 5
178 * Maximum number of desirable partial slabs.
179 * The existence of more partial slabs makes kmem_cache_shrink
180 * sort the partial list by the number of objects in the.
182 #define MAX_PARTIAL 10
184 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
185 SLAB_POISON | SLAB_STORE_USER)
188 * Set of flags that will prevent slab merging
190 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
191 SLAB_TRACE | SLAB_DESTROY_BY_RCU)
193 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
196 #ifndef ARCH_KMALLOC_MINALIGN
197 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
200 #ifndef ARCH_SLAB_MINALIGN
201 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
204 /* Internal SLUB flags */
205 #define __OBJECT_POISON 0x80000000 /* Poison object */
206 #define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
208 /* Not all arches define cache_line_size */
209 #ifndef cache_line_size
210 #define cache_line_size() L1_CACHE_BYTES
213 static int kmem_size
= sizeof(struct kmem_cache
);
216 static struct notifier_block slab_notifier
;
220 DOWN
, /* No slab functionality available */
221 PARTIAL
, /* kmem_cache_open() works but kmalloc does not */
222 UP
, /* Everything works but does not show up in sysfs */
226 /* A list of all slab caches on the system */
227 static DECLARE_RWSEM(slub_lock
);
228 static LIST_HEAD(slab_caches
);
231 * Tracking user of a slab.
234 void *addr
; /* Called from address */
235 int cpu
; /* Was running on cpu */
236 int pid
; /* Pid context */
237 unsigned long when
; /* When did the operation occur */
240 enum track_item
{ TRACK_ALLOC
, TRACK_FREE
};
242 #if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
243 static int sysfs_slab_add(struct kmem_cache
*);
244 static int sysfs_slab_alias(struct kmem_cache
*, const char *);
245 static void sysfs_slab_remove(struct kmem_cache
*);
248 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
249 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
251 static inline void sysfs_slab_remove(struct kmem_cache
*s
)
258 static inline void stat(struct kmem_cache_cpu
*c
, enum stat_item si
)
260 #ifdef CONFIG_SLUB_STATS
265 /********************************************************************
266 * Core slab cache functions
267 *******************************************************************/
269 int slab_is_available(void)
271 return slab_state
>= UP
;
274 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
277 return s
->node
[node
];
279 return &s
->local_node
;
283 static inline struct kmem_cache_cpu
*get_cpu_slab(struct kmem_cache
*s
, int cpu
)
286 return s
->cpu_slab
[cpu
];
292 /* Verify that a pointer has an address that is valid within a slab page */
293 static inline int check_valid_pointer(struct kmem_cache
*s
,
294 struct page
*page
, const void *object
)
301 base
= page_address(page
);
302 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
303 (object
- base
) % s
->size
) {
311 * Slow version of get and set free pointer.
313 * This version requires touching the cache lines of kmem_cache which
314 * we avoid to do in the fast alloc free paths. There we obtain the offset
315 * from the page struct.
317 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
319 return *(void **)(object
+ s
->offset
);
322 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
324 *(void **)(object
+ s
->offset
) = fp
;
327 /* Loop over all objects in a slab */
328 #define for_each_object(__p, __s, __addr, __objects) \
329 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
333 #define for_each_free_object(__p, __s, __free) \
334 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
336 /* Determine object index from a given position */
337 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
339 return (p
- addr
) / s
->size
;
342 static inline struct kmem_cache_order_objects
oo_make(int order
,
345 struct kmem_cache_order_objects x
= {
346 (order
<< 16) + (PAGE_SIZE
<< order
) / size
352 static inline int oo_order(struct kmem_cache_order_objects x
)
357 static inline int oo_objects(struct kmem_cache_order_objects x
)
359 return x
.x
& ((1 << 16) - 1);
362 #ifdef CONFIG_SLUB_DEBUG
366 #ifdef CONFIG_SLUB_DEBUG_ON
367 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
369 static int slub_debug
;
372 static char *slub_debug_slabs
;
377 static void print_section(char *text
, u8
*addr
, unsigned int length
)
385 for (i
= 0; i
< length
; i
++) {
387 printk(KERN_ERR
"%8s 0x%p: ", text
, addr
+ i
);
390 printk(KERN_CONT
" %02x", addr
[i
]);
392 ascii
[offset
] = isgraph(addr
[i
]) ? addr
[i
] : '.';
394 printk(KERN_CONT
" %s\n", ascii
);
401 printk(KERN_CONT
" ");
405 printk(KERN_CONT
" %s\n", ascii
);
409 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
410 enum track_item alloc
)
415 p
= object
+ s
->offset
+ sizeof(void *);
417 p
= object
+ s
->inuse
;
422 static void set_track(struct kmem_cache
*s
, void *object
,
423 enum track_item alloc
, void *addr
)
428 p
= object
+ s
->offset
+ sizeof(void *);
430 p
= object
+ s
->inuse
;
435 p
->cpu
= smp_processor_id();
436 p
->pid
= current
? current
->pid
: -1;
439 memset(p
, 0, sizeof(struct track
));
442 static void init_tracking(struct kmem_cache
*s
, void *object
)
444 if (!(s
->flags
& SLAB_STORE_USER
))
447 set_track(s
, object
, TRACK_FREE
, NULL
);
448 set_track(s
, object
, TRACK_ALLOC
, NULL
);
451 static void print_track(const char *s
, struct track
*t
)
456 printk(KERN_ERR
"INFO: %s in ", s
);
457 __print_symbol("%s", (unsigned long)t
->addr
);
458 printk(" age=%lu cpu=%u pid=%d\n", jiffies
- t
->when
, t
->cpu
, t
->pid
);
461 static void print_tracking(struct kmem_cache
*s
, void *object
)
463 if (!(s
->flags
& SLAB_STORE_USER
))
466 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
467 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
470 static void print_page_info(struct page
*page
)
472 printk(KERN_ERR
"INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
473 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
477 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
483 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
485 printk(KERN_ERR
"========================================"
486 "=====================================\n");
487 printk(KERN_ERR
"BUG %s: %s\n", s
->name
, buf
);
488 printk(KERN_ERR
"----------------------------------------"
489 "-------------------------------------\n\n");
492 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
498 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
500 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
503 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
505 unsigned int off
; /* Offset of last byte */
506 u8
*addr
= page_address(page
);
508 print_tracking(s
, p
);
510 print_page_info(page
);
512 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
513 p
, p
- addr
, get_freepointer(s
, p
));
516 print_section("Bytes b4", p
- 16, 16);
518 print_section("Object", p
, min(s
->objsize
, 128));
520 if (s
->flags
& SLAB_RED_ZONE
)
521 print_section("Redzone", p
+ s
->objsize
,
522 s
->inuse
- s
->objsize
);
525 off
= s
->offset
+ sizeof(void *);
529 if (s
->flags
& SLAB_STORE_USER
)
530 off
+= 2 * sizeof(struct track
);
533 /* Beginning of the filler is the free pointer */
534 print_section("Padding", p
+ off
, s
->size
- off
);
539 static void object_err(struct kmem_cache
*s
, struct page
*page
,
540 u8
*object
, char *reason
)
542 slab_bug(s
, "%s", reason
);
543 print_trailer(s
, page
, object
);
546 static void slab_err(struct kmem_cache
*s
, struct page
*page
, char *fmt
, ...)
552 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
554 slab_bug(s
, "%s", buf
);
555 print_page_info(page
);
559 static void init_object(struct kmem_cache
*s
, void *object
, int active
)
563 if (s
->flags
& __OBJECT_POISON
) {
564 memset(p
, POISON_FREE
, s
->objsize
- 1);
565 p
[s
->objsize
- 1] = POISON_END
;
568 if (s
->flags
& SLAB_RED_ZONE
)
569 memset(p
+ s
->objsize
,
570 active
? SLUB_RED_ACTIVE
: SLUB_RED_INACTIVE
,
571 s
->inuse
- s
->objsize
);
574 static u8
*check_bytes(u8
*start
, unsigned int value
, unsigned int bytes
)
577 if (*start
!= (u8
)value
)
585 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
586 void *from
, void *to
)
588 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
589 memset(from
, data
, to
- from
);
592 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
593 u8
*object
, char *what
,
594 u8
*start
, unsigned int value
, unsigned int bytes
)
599 fault
= check_bytes(start
, value
, bytes
);
604 while (end
> fault
&& end
[-1] == value
)
607 slab_bug(s
, "%s overwritten", what
);
608 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
609 fault
, end
- 1, fault
[0], value
);
610 print_trailer(s
, page
, object
);
612 restore_bytes(s
, what
, value
, fault
, end
);
620 * Bytes of the object to be managed.
621 * If the freepointer may overlay the object then the free
622 * pointer is the first word of the object.
624 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
627 * object + s->objsize
628 * Padding to reach word boundary. This is also used for Redzoning.
629 * Padding is extended by another word if Redzoning is enabled and
632 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
633 * 0xcc (RED_ACTIVE) for objects in use.
636 * Meta data starts here.
638 * A. Free pointer (if we cannot overwrite object on free)
639 * B. Tracking data for SLAB_STORE_USER
640 * C. Padding to reach required alignment boundary or at mininum
641 * one word if debugging is on to be able to detect writes
642 * before the word boundary.
644 * Padding is done using 0x5a (POISON_INUSE)
647 * Nothing is used beyond s->size.
649 * If slabcaches are merged then the objsize and inuse boundaries are mostly
650 * ignored. And therefore no slab options that rely on these boundaries
651 * may be used with merged slabcaches.
654 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
656 unsigned long off
= s
->inuse
; /* The end of info */
659 /* Freepointer is placed after the object. */
660 off
+= sizeof(void *);
662 if (s
->flags
& SLAB_STORE_USER
)
663 /* We also have user information there */
664 off
+= 2 * sizeof(struct track
);
669 return check_bytes_and_report(s
, page
, p
, "Object padding",
670 p
+ off
, POISON_INUSE
, s
->size
- off
);
673 /* Check the pad bytes at the end of a slab page */
674 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
682 if (!(s
->flags
& SLAB_POISON
))
685 start
= page_address(page
);
686 length
= (PAGE_SIZE
<< compound_order(page
));
687 end
= start
+ length
;
688 remainder
= length
% s
->size
;
692 fault
= check_bytes(end
- remainder
, POISON_INUSE
, remainder
);
695 while (end
> fault
&& end
[-1] == POISON_INUSE
)
698 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
699 print_section("Padding", end
- remainder
, remainder
);
701 restore_bytes(s
, "slab padding", POISON_INUSE
, start
, end
);
705 static int check_object(struct kmem_cache
*s
, struct page
*page
,
706 void *object
, int active
)
709 u8
*endobject
= object
+ s
->objsize
;
711 if (s
->flags
& SLAB_RED_ZONE
) {
713 active
? SLUB_RED_ACTIVE
: SLUB_RED_INACTIVE
;
715 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
716 endobject
, red
, s
->inuse
- s
->objsize
))
719 if ((s
->flags
& SLAB_POISON
) && s
->objsize
< s
->inuse
) {
720 check_bytes_and_report(s
, page
, p
, "Alignment padding",
721 endobject
, POISON_INUSE
, s
->inuse
- s
->objsize
);
725 if (s
->flags
& SLAB_POISON
) {
726 if (!active
&& (s
->flags
& __OBJECT_POISON
) &&
727 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
728 POISON_FREE
, s
->objsize
- 1) ||
729 !check_bytes_and_report(s
, page
, p
, "Poison",
730 p
+ s
->objsize
- 1, POISON_END
, 1)))
733 * check_pad_bytes cleans up on its own.
735 check_pad_bytes(s
, page
, p
);
738 if (!s
->offset
&& active
)
740 * Object and freepointer overlap. Cannot check
741 * freepointer while object is allocated.
745 /* Check free pointer validity */
746 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
747 object_err(s
, page
, p
, "Freepointer corrupt");
749 * No choice but to zap it and thus loose the remainder
750 * of the free objects in this slab. May cause
751 * another error because the object count is now wrong.
753 set_freepointer(s
, p
, NULL
);
759 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
763 VM_BUG_ON(!irqs_disabled());
765 if (!PageSlab(page
)) {
766 slab_err(s
, page
, "Not a valid slab page");
770 maxobj
= (PAGE_SIZE
<< compound_order(page
)) / s
->size
;
771 if (page
->objects
> maxobj
) {
772 slab_err(s
, page
, "objects %u > max %u",
773 s
->name
, page
->objects
, maxobj
);
776 if (page
->inuse
> page
->objects
) {
777 slab_err(s
, page
, "inuse %u > max %u",
778 s
->name
, page
->inuse
, page
->objects
);
781 /* Slab_pad_check fixes things up after itself */
782 slab_pad_check(s
, page
);
787 * Determine if a certain object on a page is on the freelist. Must hold the
788 * slab lock to guarantee that the chains are in a consistent state.
790 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
793 void *fp
= page
->freelist
;
795 unsigned long max_objects
;
797 while (fp
&& nr
<= page
->objects
) {
800 if (!check_valid_pointer(s
, page
, fp
)) {
802 object_err(s
, page
, object
,
803 "Freechain corrupt");
804 set_freepointer(s
, object
, NULL
);
807 slab_err(s
, page
, "Freepointer corrupt");
808 page
->freelist
= NULL
;
809 page
->inuse
= page
->objects
;
810 slab_fix(s
, "Freelist cleared");
816 fp
= get_freepointer(s
, object
);
820 max_objects
= (PAGE_SIZE
<< compound_order(page
)) / s
->size
;
821 if (max_objects
> 65535)
824 if (page
->objects
!= max_objects
) {
825 slab_err(s
, page
, "Wrong number of objects. Found %d but "
826 "should be %d", page
->objects
, max_objects
);
827 page
->objects
= max_objects
;
828 slab_fix(s
, "Number of objects adjusted.");
830 if (page
->inuse
!= page
->objects
- nr
) {
831 slab_err(s
, page
, "Wrong object count. Counter is %d but "
832 "counted were %d", page
->inuse
, page
->objects
- nr
);
833 page
->inuse
= page
->objects
- nr
;
834 slab_fix(s
, "Object count adjusted.");
836 return search
== NULL
;
839 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
, int alloc
)
841 if (s
->flags
& SLAB_TRACE
) {
842 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
844 alloc
? "alloc" : "free",
849 print_section("Object", (void *)object
, s
->objsize
);
856 * Tracking of fully allocated slabs for debugging purposes.
858 static void add_full(struct kmem_cache_node
*n
, struct page
*page
)
860 spin_lock(&n
->list_lock
);
861 list_add(&page
->lru
, &n
->full
);
862 spin_unlock(&n
->list_lock
);
865 static void remove_full(struct kmem_cache
*s
, struct page
*page
)
867 struct kmem_cache_node
*n
;
869 if (!(s
->flags
& SLAB_STORE_USER
))
872 n
= get_node(s
, page_to_nid(page
));
874 spin_lock(&n
->list_lock
);
875 list_del(&page
->lru
);
876 spin_unlock(&n
->list_lock
);
879 /* Tracking of the number of slabs for debugging purposes */
880 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
882 struct kmem_cache_node
*n
= get_node(s
, node
);
884 return atomic_long_read(&n
->nr_slabs
);
887 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
889 struct kmem_cache_node
*n
= get_node(s
, node
);
892 * May be called early in order to allocate a slab for the
893 * kmem_cache_node structure. Solve the chicken-egg
894 * dilemma by deferring the increment of the count during
895 * bootstrap (see early_kmem_cache_node_alloc).
897 if (!NUMA_BUILD
|| n
) {
898 atomic_long_inc(&n
->nr_slabs
);
899 atomic_long_add(objects
, &n
->total_objects
);
902 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
904 struct kmem_cache_node
*n
= get_node(s
, node
);
906 atomic_long_dec(&n
->nr_slabs
);
907 atomic_long_sub(objects
, &n
->total_objects
);
910 /* Object debug checks for alloc/free paths */
911 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
914 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
917 init_object(s
, object
, 0);
918 init_tracking(s
, object
);
921 static int alloc_debug_processing(struct kmem_cache
*s
, struct page
*page
,
922 void *object
, void *addr
)
924 if (!check_slab(s
, page
))
927 if (!on_freelist(s
, page
, object
)) {
928 object_err(s
, page
, object
, "Object already allocated");
932 if (!check_valid_pointer(s
, page
, object
)) {
933 object_err(s
, page
, object
, "Freelist Pointer check fails");
937 if (!check_object(s
, page
, object
, 0))
940 /* Success perform special debug activities for allocs */
941 if (s
->flags
& SLAB_STORE_USER
)
942 set_track(s
, object
, TRACK_ALLOC
, addr
);
943 trace(s
, page
, object
, 1);
944 init_object(s
, object
, 1);
948 if (PageSlab(page
)) {
950 * If this is a slab page then lets do the best we can
951 * to avoid issues in the future. Marking all objects
952 * as used avoids touching the remaining objects.
954 slab_fix(s
, "Marking all objects used");
955 page
->inuse
= page
->objects
;
956 page
->freelist
= NULL
;
961 static int free_debug_processing(struct kmem_cache
*s
, struct page
*page
,
962 void *object
, void *addr
)
964 if (!check_slab(s
, page
))
967 if (!check_valid_pointer(s
, page
, object
)) {
968 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
972 if (on_freelist(s
, page
, object
)) {
973 object_err(s
, page
, object
, "Object already free");
977 if (!check_object(s
, page
, object
, 1))
980 if (unlikely(s
!= page
->slab
)) {
981 if (!PageSlab(page
)) {
982 slab_err(s
, page
, "Attempt to free object(0x%p) "
983 "outside of slab", object
);
984 } else if (!page
->slab
) {
986 "SLUB <none>: no slab for object 0x%p.\n",
990 object_err(s
, page
, object
,
991 "page slab pointer corrupt.");
995 /* Special debug activities for freeing objects */
996 if (!SlabFrozen(page
) && !page
->freelist
)
997 remove_full(s
, page
);
998 if (s
->flags
& SLAB_STORE_USER
)
999 set_track(s
, object
, TRACK_FREE
, addr
);
1000 trace(s
, page
, object
, 0);
1001 init_object(s
, object
, 0);
1005 slab_fix(s
, "Object at 0x%p not freed", object
);
1009 static int __init
setup_slub_debug(char *str
)
1011 slub_debug
= DEBUG_DEFAULT_FLAGS
;
1012 if (*str
++ != '=' || !*str
)
1014 * No options specified. Switch on full debugging.
1020 * No options but restriction on slabs. This means full
1021 * debugging for slabs matching a pattern.
1028 * Switch off all debugging measures.
1033 * Determine which debug features should be switched on
1035 for (; *str
&& *str
!= ','; str
++) {
1036 switch (tolower(*str
)) {
1038 slub_debug
|= SLAB_DEBUG_FREE
;
1041 slub_debug
|= SLAB_RED_ZONE
;
1044 slub_debug
|= SLAB_POISON
;
1047 slub_debug
|= SLAB_STORE_USER
;
1050 slub_debug
|= SLAB_TRACE
;
1053 printk(KERN_ERR
"slub_debug option '%c' "
1054 "unknown. skipped\n", *str
);
1060 slub_debug_slabs
= str
+ 1;
1065 __setup("slub_debug", setup_slub_debug
);
1067 static unsigned long kmem_cache_flags(unsigned long objsize
,
1068 unsigned long flags
, const char *name
,
1069 void (*ctor
)(struct kmem_cache
*, void *))
1072 * Enable debugging if selected on the kernel commandline.
1074 if (slub_debug
&& (!slub_debug_slabs
||
1075 strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
)) == 0))
1076 flags
|= slub_debug
;
1081 static inline void setup_object_debug(struct kmem_cache
*s
,
1082 struct page
*page
, void *object
) {}
1084 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1085 struct page
*page
, void *object
, void *addr
) { return 0; }
1087 static inline int free_debug_processing(struct kmem_cache
*s
,
1088 struct page
*page
, void *object
, void *addr
) { return 0; }
1090 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1092 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1093 void *object
, int active
) { return 1; }
1094 static inline void add_full(struct kmem_cache_node
*n
, struct page
*page
) {}
1095 static inline unsigned long kmem_cache_flags(unsigned long objsize
,
1096 unsigned long flags
, const char *name
,
1097 void (*ctor
)(struct kmem_cache
*, void *))
1101 #define slub_debug 0
1103 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1105 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1107 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1112 * Slab allocation and freeing
1114 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1115 struct kmem_cache_order_objects oo
)
1117 int order
= oo_order(oo
);
1120 return alloc_pages(flags
, order
);
1122 return alloc_pages_node(node
, flags
, order
);
1125 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1128 struct kmem_cache_order_objects oo
= s
->oo
;
1130 flags
|= s
->allocflags
;
1132 page
= alloc_slab_page(flags
| __GFP_NOWARN
| __GFP_NORETRY
, node
,
1134 if (unlikely(!page
)) {
1137 * Allocation may have failed due to fragmentation.
1138 * Try a lower order alloc if possible
1140 page
= alloc_slab_page(flags
, node
, oo
);
1144 stat(get_cpu_slab(s
, raw_smp_processor_id()), ORDER_FALLBACK
);
1146 page
->objects
= oo_objects(oo
);
1147 mod_zone_page_state(page_zone(page
),
1148 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1149 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1155 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1158 setup_object_debug(s
, page
, object
);
1159 if (unlikely(s
->ctor
))
1163 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1170 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1172 page
= allocate_slab(s
,
1173 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1177 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1179 page
->flags
|= 1 << PG_slab
;
1180 if (s
->flags
& (SLAB_DEBUG_FREE
| SLAB_RED_ZONE
| SLAB_POISON
|
1181 SLAB_STORE_USER
| SLAB_TRACE
))
1184 start
= page_address(page
);
1186 if (unlikely(s
->flags
& SLAB_POISON
))
1187 memset(start
, POISON_INUSE
, PAGE_SIZE
<< compound_order(page
));
1190 for_each_object(p
, s
, start
, page
->objects
) {
1191 setup_object(s
, page
, last
);
1192 set_freepointer(s
, last
, p
);
1195 setup_object(s
, page
, last
);
1196 set_freepointer(s
, last
, NULL
);
1198 page
->freelist
= start
;
1204 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1206 int order
= compound_order(page
);
1207 int pages
= 1 << order
;
1209 if (unlikely(SlabDebug(page
))) {
1212 slab_pad_check(s
, page
);
1213 for_each_object(p
, s
, page_address(page
),
1215 check_object(s
, page
, p
, 0);
1216 ClearSlabDebug(page
);
1219 mod_zone_page_state(page_zone(page
),
1220 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1221 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1224 __ClearPageSlab(page
);
1225 reset_page_mapcount(page
);
1226 __free_pages(page
, order
);
1229 static void rcu_free_slab(struct rcu_head
*h
)
1233 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1234 __free_slab(page
->slab
, page
);
1237 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1239 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1241 * RCU free overloads the RCU head over the LRU
1243 struct rcu_head
*head
= (void *)&page
->lru
;
1245 call_rcu(head
, rcu_free_slab
);
1247 __free_slab(s
, page
);
1250 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1252 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1257 * Per slab locking using the pagelock
1259 static __always_inline
void slab_lock(struct page
*page
)
1261 bit_spin_lock(PG_locked
, &page
->flags
);
1264 static __always_inline
void slab_unlock(struct page
*page
)
1266 __bit_spin_unlock(PG_locked
, &page
->flags
);
1269 static __always_inline
int slab_trylock(struct page
*page
)
1273 rc
= bit_spin_trylock(PG_locked
, &page
->flags
);
1278 * Management of partially allocated slabs
1280 static void add_partial(struct kmem_cache_node
*n
,
1281 struct page
*page
, int tail
)
1283 spin_lock(&n
->list_lock
);
1286 list_add_tail(&page
->lru
, &n
->partial
);
1288 list_add(&page
->lru
, &n
->partial
);
1289 spin_unlock(&n
->list_lock
);
1292 static void remove_partial(struct kmem_cache
*s
,
1295 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1297 spin_lock(&n
->list_lock
);
1298 list_del(&page
->lru
);
1300 spin_unlock(&n
->list_lock
);
1304 * Lock slab and remove from the partial list.
1306 * Must hold list_lock.
1308 static inline int lock_and_freeze_slab(struct kmem_cache_node
*n
, struct page
*page
)
1310 if (slab_trylock(page
)) {
1311 list_del(&page
->lru
);
1313 SetSlabFrozen(page
);
1320 * Try to allocate a partial slab from a specific node.
1322 static struct page
*get_partial_node(struct kmem_cache_node
*n
)
1327 * Racy check. If we mistakenly see no partial slabs then we
1328 * just allocate an empty slab. If we mistakenly try to get a
1329 * partial slab and there is none available then get_partials()
1332 if (!n
|| !n
->nr_partial
)
1335 spin_lock(&n
->list_lock
);
1336 list_for_each_entry(page
, &n
->partial
, lru
)
1337 if (lock_and_freeze_slab(n
, page
))
1341 spin_unlock(&n
->list_lock
);
1346 * Get a page from somewhere. Search in increasing NUMA distances.
1348 static struct page
*get_any_partial(struct kmem_cache
*s
, gfp_t flags
)
1351 struct zonelist
*zonelist
;
1356 * The defrag ratio allows a configuration of the tradeoffs between
1357 * inter node defragmentation and node local allocations. A lower
1358 * defrag_ratio increases the tendency to do local allocations
1359 * instead of attempting to obtain partial slabs from other nodes.
1361 * If the defrag_ratio is set to 0 then kmalloc() always
1362 * returns node local objects. If the ratio is higher then kmalloc()
1363 * may return off node objects because partial slabs are obtained
1364 * from other nodes and filled up.
1366 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1367 * defrag_ratio = 1000) then every (well almost) allocation will
1368 * first attempt to defrag slab caches on other nodes. This means
1369 * scanning over all nodes to look for partial slabs which may be
1370 * expensive if we do it every time we are trying to find a slab
1371 * with available objects.
1373 if (!s
->remote_node_defrag_ratio
||
1374 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1377 zonelist
= &NODE_DATA(
1378 slab_node(current
->mempolicy
))->node_zonelists
[gfp_zone(flags
)];
1379 for (z
= zonelist
->zones
; *z
; z
++) {
1380 struct kmem_cache_node
*n
;
1382 n
= get_node(s
, zone_to_nid(*z
));
1384 if (n
&& cpuset_zone_allowed_hardwall(*z
, flags
) &&
1385 n
->nr_partial
> MIN_PARTIAL
) {
1386 page
= get_partial_node(n
);
1396 * Get a partial page, lock it and return it.
1398 static struct page
*get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
)
1401 int searchnode
= (node
== -1) ? numa_node_id() : node
;
1403 page
= get_partial_node(get_node(s
, searchnode
));
1404 if (page
|| (flags
& __GFP_THISNODE
))
1407 return get_any_partial(s
, flags
);
1411 * Move a page back to the lists.
1413 * Must be called with the slab lock held.
1415 * On exit the slab lock will have been dropped.
1417 static void unfreeze_slab(struct kmem_cache
*s
, struct page
*page
, int tail
)
1419 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1420 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, smp_processor_id());
1422 ClearSlabFrozen(page
);
1425 if (page
->freelist
) {
1426 add_partial(n
, page
, tail
);
1427 stat(c
, tail
? DEACTIVATE_TO_TAIL
: DEACTIVATE_TO_HEAD
);
1429 stat(c
, DEACTIVATE_FULL
);
1430 if (SlabDebug(page
) && (s
->flags
& SLAB_STORE_USER
))
1435 stat(c
, DEACTIVATE_EMPTY
);
1436 if (n
->nr_partial
< MIN_PARTIAL
) {
1438 * Adding an empty slab to the partial slabs in order
1439 * to avoid page allocator overhead. This slab needs
1440 * to come after the other slabs with objects in
1441 * so that the others get filled first. That way the
1442 * size of the partial list stays small.
1444 * kmem_cache_shrink can reclaim any empty slabs from the
1447 add_partial(n
, page
, 1);
1451 stat(get_cpu_slab(s
, raw_smp_processor_id()), FREE_SLAB
);
1452 discard_slab(s
, page
);
1458 * Remove the cpu slab
1460 static void deactivate_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1462 struct page
*page
= c
->page
;
1466 stat(c
, DEACTIVATE_REMOTE_FREES
);
1468 * Merge cpu freelist into slab freelist. Typically we get here
1469 * because both freelists are empty. So this is unlikely
1472 while (unlikely(c
->freelist
)) {
1475 tail
= 0; /* Hot objects. Put the slab first */
1477 /* Retrieve object from cpu_freelist */
1478 object
= c
->freelist
;
1479 c
->freelist
= c
->freelist
[c
->offset
];
1481 /* And put onto the regular freelist */
1482 object
[c
->offset
] = page
->freelist
;
1483 page
->freelist
= object
;
1487 unfreeze_slab(s
, page
, tail
);
1490 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1492 stat(c
, CPUSLAB_FLUSH
);
1494 deactivate_slab(s
, c
);
1500 * Called from IPI handler with interrupts disabled.
1502 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
1504 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
1506 if (likely(c
&& c
->page
))
1510 static void flush_cpu_slab(void *d
)
1512 struct kmem_cache
*s
= d
;
1514 __flush_cpu_slab(s
, smp_processor_id());
1517 static void flush_all(struct kmem_cache
*s
)
1520 on_each_cpu(flush_cpu_slab
, s
, 1, 1);
1522 unsigned long flags
;
1524 local_irq_save(flags
);
1526 local_irq_restore(flags
);
1531 * Check if the objects in a per cpu structure fit numa
1532 * locality expectations.
1534 static inline int node_match(struct kmem_cache_cpu
*c
, int node
)
1537 if (node
!= -1 && c
->node
!= node
)
1544 * Slow path. The lockless freelist is empty or we need to perform
1547 * Interrupts are disabled.
1549 * Processing is still very fast if new objects have been freed to the
1550 * regular freelist. In that case we simply take over the regular freelist
1551 * as the lockless freelist and zap the regular freelist.
1553 * If that is not working then we fall back to the partial lists. We take the
1554 * first element of the freelist as the object to allocate now and move the
1555 * rest of the freelist to the lockless freelist.
1557 * And if we were unable to get a new slab from the partial slab lists then
1558 * we need to allocate a new slab. This is the slowest path since it involves
1559 * a call to the page allocator and the setup of a new slab.
1561 static void *__slab_alloc(struct kmem_cache
*s
,
1562 gfp_t gfpflags
, int node
, void *addr
, struct kmem_cache_cpu
*c
)
1567 /* We handle __GFP_ZERO in the caller */
1568 gfpflags
&= ~__GFP_ZERO
;
1574 if (unlikely(!node_match(c
, node
)))
1577 stat(c
, ALLOC_REFILL
);
1580 object
= c
->page
->freelist
;
1581 if (unlikely(!object
))
1583 if (unlikely(SlabDebug(c
->page
)))
1586 c
->freelist
= object
[c
->offset
];
1587 c
->page
->inuse
= c
->page
->objects
;
1588 c
->page
->freelist
= NULL
;
1589 c
->node
= page_to_nid(c
->page
);
1591 slab_unlock(c
->page
);
1592 stat(c
, ALLOC_SLOWPATH
);
1596 deactivate_slab(s
, c
);
1599 new = get_partial(s
, gfpflags
, node
);
1602 stat(c
, ALLOC_FROM_PARTIAL
);
1606 if (gfpflags
& __GFP_WAIT
)
1609 new = new_slab(s
, gfpflags
, node
);
1611 if (gfpflags
& __GFP_WAIT
)
1612 local_irq_disable();
1615 c
= get_cpu_slab(s
, smp_processor_id());
1616 stat(c
, ALLOC_SLAB
);
1626 if (!alloc_debug_processing(s
, c
->page
, object
, addr
))
1630 c
->page
->freelist
= object
[c
->offset
];
1636 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1637 * have the fastpath folded into their functions. So no function call
1638 * overhead for requests that can be satisfied on the fastpath.
1640 * The fastpath works by first checking if the lockless freelist can be used.
1641 * If not then __slab_alloc is called for slow processing.
1643 * Otherwise we can simply pick the next object from the lockless free list.
1645 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
1646 gfp_t gfpflags
, int node
, void *addr
)
1649 struct kmem_cache_cpu
*c
;
1650 unsigned long flags
;
1652 local_irq_save(flags
);
1653 c
= get_cpu_slab(s
, smp_processor_id());
1654 if (unlikely(!c
->freelist
|| !node_match(c
, node
)))
1656 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
1659 object
= c
->freelist
;
1660 c
->freelist
= object
[c
->offset
];
1661 stat(c
, ALLOC_FASTPATH
);
1663 local_irq_restore(flags
);
1665 if (unlikely((gfpflags
& __GFP_ZERO
) && object
))
1666 memset(object
, 0, c
->objsize
);
1671 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
1673 return slab_alloc(s
, gfpflags
, -1, __builtin_return_address(0));
1675 EXPORT_SYMBOL(kmem_cache_alloc
);
1678 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
1680 return slab_alloc(s
, gfpflags
, node
, __builtin_return_address(0));
1682 EXPORT_SYMBOL(kmem_cache_alloc_node
);
1686 * Slow patch handling. This may still be called frequently since objects
1687 * have a longer lifetime than the cpu slabs in most processing loads.
1689 * So we still attempt to reduce cache line usage. Just take the slab
1690 * lock and free the item. If there is no additional partial page
1691 * handling required then we can return immediately.
1693 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
1694 void *x
, void *addr
, unsigned int offset
)
1697 void **object
= (void *)x
;
1698 struct kmem_cache_cpu
*c
;
1700 c
= get_cpu_slab(s
, raw_smp_processor_id());
1701 stat(c
, FREE_SLOWPATH
);
1704 if (unlikely(SlabDebug(page
)))
1708 prior
= object
[offset
] = page
->freelist
;
1709 page
->freelist
= object
;
1712 if (unlikely(SlabFrozen(page
))) {
1713 stat(c
, FREE_FROZEN
);
1717 if (unlikely(!page
->inuse
))
1721 * Objects left in the slab. If it was not on the partial list before
1724 if (unlikely(!prior
)) {
1725 add_partial(get_node(s
, page_to_nid(page
)), page
, 1);
1726 stat(c
, FREE_ADD_PARTIAL
);
1736 * Slab still on the partial list.
1738 remove_partial(s
, page
);
1739 stat(c
, FREE_REMOVE_PARTIAL
);
1743 discard_slab(s
, page
);
1747 if (!free_debug_processing(s
, page
, x
, addr
))
1753 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
1754 * can perform fastpath freeing without additional function calls.
1756 * The fastpath is only possible if we are freeing to the current cpu slab
1757 * of this processor. This typically the case if we have just allocated
1760 * If fastpath is not possible then fall back to __slab_free where we deal
1761 * with all sorts of special processing.
1763 static __always_inline
void slab_free(struct kmem_cache
*s
,
1764 struct page
*page
, void *x
, void *addr
)
1766 void **object
= (void *)x
;
1767 struct kmem_cache_cpu
*c
;
1768 unsigned long flags
;
1770 local_irq_save(flags
);
1771 c
= get_cpu_slab(s
, smp_processor_id());
1772 debug_check_no_locks_freed(object
, c
->objsize
);
1773 if (likely(page
== c
->page
&& c
->node
>= 0)) {
1774 object
[c
->offset
] = c
->freelist
;
1775 c
->freelist
= object
;
1776 stat(c
, FREE_FASTPATH
);
1778 __slab_free(s
, page
, x
, addr
, c
->offset
);
1780 local_irq_restore(flags
);
1783 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
1787 page
= virt_to_head_page(x
);
1789 slab_free(s
, page
, x
, __builtin_return_address(0));
1791 EXPORT_SYMBOL(kmem_cache_free
);
1793 /* Figure out on which slab object the object resides */
1794 static struct page
*get_object_page(const void *x
)
1796 struct page
*page
= virt_to_head_page(x
);
1798 if (!PageSlab(page
))
1805 * Object placement in a slab is made very easy because we always start at
1806 * offset 0. If we tune the size of the object to the alignment then we can
1807 * get the required alignment by putting one properly sized object after
1810 * Notice that the allocation order determines the sizes of the per cpu
1811 * caches. Each processor has always one slab available for allocations.
1812 * Increasing the allocation order reduces the number of times that slabs
1813 * must be moved on and off the partial lists and is therefore a factor in
1818 * Mininum / Maximum order of slab pages. This influences locking overhead
1819 * and slab fragmentation. A higher order reduces the number of partial slabs
1820 * and increases the number of allocations possible without having to
1821 * take the list_lock.
1823 static int slub_min_order
;
1824 static int slub_max_order
= DEFAULT_MAX_ORDER
;
1825 static int slub_min_objects
= DEFAULT_MIN_OBJECTS
;
1828 * Merge control. If this is set then no merging of slab caches will occur.
1829 * (Could be removed. This was introduced to pacify the merge skeptics.)
1831 static int slub_nomerge
;
1834 * Calculate the order of allocation given an slab object size.
1836 * The order of allocation has significant impact on performance and other
1837 * system components. Generally order 0 allocations should be preferred since
1838 * order 0 does not cause fragmentation in the page allocator. Larger objects
1839 * be problematic to put into order 0 slabs because there may be too much
1840 * unused space left. We go to a higher order if more than 1/8th of the slab
1843 * In order to reach satisfactory performance we must ensure that a minimum
1844 * number of objects is in one slab. Otherwise we may generate too much
1845 * activity on the partial lists which requires taking the list_lock. This is
1846 * less a concern for large slabs though which are rarely used.
1848 * slub_max_order specifies the order where we begin to stop considering the
1849 * number of objects in a slab as critical. If we reach slub_max_order then
1850 * we try to keep the page order as low as possible. So we accept more waste
1851 * of space in favor of a small page order.
1853 * Higher order allocations also allow the placement of more objects in a
1854 * slab and thereby reduce object handling overhead. If the user has
1855 * requested a higher mininum order then we start with that one instead of
1856 * the smallest order which will fit the object.
1858 static inline int slab_order(int size
, int min_objects
,
1859 int max_order
, int fract_leftover
)
1863 int min_order
= slub_min_order
;
1865 if ((PAGE_SIZE
<< min_order
) / size
> 65535)
1866 return get_order(size
* 65535) - 1;
1868 for (order
= max(min_order
,
1869 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
1870 order
<= max_order
; order
++) {
1872 unsigned long slab_size
= PAGE_SIZE
<< order
;
1874 if (slab_size
< min_objects
* size
)
1877 rem
= slab_size
% size
;
1879 if (rem
<= slab_size
/ fract_leftover
)
1887 static inline int calculate_order(int size
)
1894 * Attempt to find best configuration for a slab. This
1895 * works by first attempting to generate a layout with
1896 * the best configuration and backing off gradually.
1898 * First we reduce the acceptable waste in a slab. Then
1899 * we reduce the minimum objects required in a slab.
1901 min_objects
= slub_min_objects
;
1902 while (min_objects
> 1) {
1904 while (fraction
>= 4) {
1905 order
= slab_order(size
, min_objects
,
1906 slub_max_order
, fraction
);
1907 if (order
<= slub_max_order
)
1915 * We were unable to place multiple objects in a slab. Now
1916 * lets see if we can place a single object there.
1918 order
= slab_order(size
, 1, slub_max_order
, 1);
1919 if (order
<= slub_max_order
)
1923 * Doh this slab cannot be placed using slub_max_order.
1925 order
= slab_order(size
, 1, MAX_ORDER
, 1);
1926 if (order
<= MAX_ORDER
)
1932 * Figure out what the alignment of the objects will be.
1934 static unsigned long calculate_alignment(unsigned long flags
,
1935 unsigned long align
, unsigned long size
)
1938 * If the user wants hardware cache aligned objects then follow that
1939 * suggestion if the object is sufficiently large.
1941 * The hardware cache alignment cannot override the specified
1942 * alignment though. If that is greater then use it.
1944 if (flags
& SLAB_HWCACHE_ALIGN
) {
1945 unsigned long ralign
= cache_line_size();
1946 while (size
<= ralign
/ 2)
1948 align
= max(align
, ralign
);
1951 if (align
< ARCH_SLAB_MINALIGN
)
1952 align
= ARCH_SLAB_MINALIGN
;
1954 return ALIGN(align
, sizeof(void *));
1957 static void init_kmem_cache_cpu(struct kmem_cache
*s
,
1958 struct kmem_cache_cpu
*c
)
1963 c
->offset
= s
->offset
/ sizeof(void *);
1964 c
->objsize
= s
->objsize
;
1965 #ifdef CONFIG_SLUB_STATS
1966 memset(c
->stat
, 0, NR_SLUB_STAT_ITEMS
* sizeof(unsigned));
1970 static void init_kmem_cache_node(struct kmem_cache_node
*n
)
1973 spin_lock_init(&n
->list_lock
);
1974 INIT_LIST_HEAD(&n
->partial
);
1975 #ifdef CONFIG_SLUB_DEBUG
1976 atomic_long_set(&n
->nr_slabs
, 0);
1977 INIT_LIST_HEAD(&n
->full
);
1983 * Per cpu array for per cpu structures.
1985 * The per cpu array places all kmem_cache_cpu structures from one processor
1986 * close together meaning that it becomes possible that multiple per cpu
1987 * structures are contained in one cacheline. This may be particularly
1988 * beneficial for the kmalloc caches.
1990 * A desktop system typically has around 60-80 slabs. With 100 here we are
1991 * likely able to get per cpu structures for all caches from the array defined
1992 * here. We must be able to cover all kmalloc caches during bootstrap.
1994 * If the per cpu array is exhausted then fall back to kmalloc
1995 * of individual cachelines. No sharing is possible then.
1997 #define NR_KMEM_CACHE_CPU 100
1999 static DEFINE_PER_CPU(struct kmem_cache_cpu
,
2000 kmem_cache_cpu
)[NR_KMEM_CACHE_CPU
];
2002 static DEFINE_PER_CPU(struct kmem_cache_cpu
*, kmem_cache_cpu_free
);
2003 static cpumask_t kmem_cach_cpu_free_init_once
= CPU_MASK_NONE
;
2005 static struct kmem_cache_cpu
*alloc_kmem_cache_cpu(struct kmem_cache
*s
,
2006 int cpu
, gfp_t flags
)
2008 struct kmem_cache_cpu
*c
= per_cpu(kmem_cache_cpu_free
, cpu
);
2011 per_cpu(kmem_cache_cpu_free
, cpu
) =
2012 (void *)c
->freelist
;
2014 /* Table overflow: So allocate ourselves */
2016 ALIGN(sizeof(struct kmem_cache_cpu
), cache_line_size()),
2017 flags
, cpu_to_node(cpu
));
2022 init_kmem_cache_cpu(s
, c
);
2026 static void free_kmem_cache_cpu(struct kmem_cache_cpu
*c
, int cpu
)
2028 if (c
< per_cpu(kmem_cache_cpu
, cpu
) ||
2029 c
> per_cpu(kmem_cache_cpu
, cpu
) + NR_KMEM_CACHE_CPU
) {
2033 c
->freelist
= (void *)per_cpu(kmem_cache_cpu_free
, cpu
);
2034 per_cpu(kmem_cache_cpu_free
, cpu
) = c
;
2037 static void free_kmem_cache_cpus(struct kmem_cache
*s
)
2041 for_each_online_cpu(cpu
) {
2042 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
2045 s
->cpu_slab
[cpu
] = NULL
;
2046 free_kmem_cache_cpu(c
, cpu
);
2051 static int alloc_kmem_cache_cpus(struct kmem_cache
*s
, gfp_t flags
)
2055 for_each_online_cpu(cpu
) {
2056 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
2061 c
= alloc_kmem_cache_cpu(s
, cpu
, flags
);
2063 free_kmem_cache_cpus(s
);
2066 s
->cpu_slab
[cpu
] = c
;
2072 * Initialize the per cpu array.
2074 static void init_alloc_cpu_cpu(int cpu
)
2078 if (cpu_isset(cpu
, kmem_cach_cpu_free_init_once
))
2081 for (i
= NR_KMEM_CACHE_CPU
- 1; i
>= 0; i
--)
2082 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu
, cpu
)[i
], cpu
);
2084 cpu_set(cpu
, kmem_cach_cpu_free_init_once
);
2087 static void __init
init_alloc_cpu(void)
2091 for_each_online_cpu(cpu
)
2092 init_alloc_cpu_cpu(cpu
);
2096 static inline void free_kmem_cache_cpus(struct kmem_cache
*s
) {}
2097 static inline void init_alloc_cpu(void) {}
2099 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
, gfp_t flags
)
2101 init_kmem_cache_cpu(s
, &s
->cpu_slab
);
2108 * No kmalloc_node yet so do it by hand. We know that this is the first
2109 * slab on the node for this slabcache. There are no concurrent accesses
2112 * Note that this function only works on the kmalloc_node_cache
2113 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2114 * memory on a fresh node that has no slab structures yet.
2116 static struct kmem_cache_node
*early_kmem_cache_node_alloc(gfp_t gfpflags
,
2120 struct kmem_cache_node
*n
;
2121 unsigned long flags
;
2123 BUG_ON(kmalloc_caches
->size
< sizeof(struct kmem_cache_node
));
2125 page
= new_slab(kmalloc_caches
, gfpflags
, node
);
2128 if (page_to_nid(page
) != node
) {
2129 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2131 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2132 "in order to be able to continue\n");
2137 page
->freelist
= get_freepointer(kmalloc_caches
, n
);
2139 kmalloc_caches
->node
[node
] = n
;
2140 #ifdef CONFIG_SLUB_DEBUG
2141 init_object(kmalloc_caches
, n
, 1);
2142 init_tracking(kmalloc_caches
, n
);
2144 init_kmem_cache_node(n
);
2145 inc_slabs_node(kmalloc_caches
, node
, page
->objects
);
2148 * lockdep requires consistent irq usage for each lock
2149 * so even though there cannot be a race this early in
2150 * the boot sequence, we still disable irqs.
2152 local_irq_save(flags
);
2153 add_partial(n
, page
, 0);
2154 local_irq_restore(flags
);
2158 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2162 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2163 struct kmem_cache_node
*n
= s
->node
[node
];
2164 if (n
&& n
!= &s
->local_node
)
2165 kmem_cache_free(kmalloc_caches
, n
);
2166 s
->node
[node
] = NULL
;
2170 static int init_kmem_cache_nodes(struct kmem_cache
*s
, gfp_t gfpflags
)
2175 if (slab_state
>= UP
)
2176 local_node
= page_to_nid(virt_to_page(s
));
2180 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2181 struct kmem_cache_node
*n
;
2183 if (local_node
== node
)
2186 if (slab_state
== DOWN
) {
2187 n
= early_kmem_cache_node_alloc(gfpflags
,
2191 n
= kmem_cache_alloc_node(kmalloc_caches
,
2195 free_kmem_cache_nodes(s
);
2201 init_kmem_cache_node(n
);
2206 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2210 static int init_kmem_cache_nodes(struct kmem_cache
*s
, gfp_t gfpflags
)
2212 init_kmem_cache_node(&s
->local_node
);
2218 * calculate_sizes() determines the order and the distribution of data within
2221 static int calculate_sizes(struct kmem_cache
*s
)
2223 unsigned long flags
= s
->flags
;
2224 unsigned long size
= s
->objsize
;
2225 unsigned long align
= s
->align
;
2229 * Round up object size to the next word boundary. We can only
2230 * place the free pointer at word boundaries and this determines
2231 * the possible location of the free pointer.
2233 size
= ALIGN(size
, sizeof(void *));
2235 #ifdef CONFIG_SLUB_DEBUG
2237 * Determine if we can poison the object itself. If the user of
2238 * the slab may touch the object after free or before allocation
2239 * then we should never poison the object itself.
2241 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2243 s
->flags
|= __OBJECT_POISON
;
2245 s
->flags
&= ~__OBJECT_POISON
;
2249 * If we are Redzoning then check if there is some space between the
2250 * end of the object and the free pointer. If not then add an
2251 * additional word to have some bytes to store Redzone information.
2253 if ((flags
& SLAB_RED_ZONE
) && size
== s
->objsize
)
2254 size
+= sizeof(void *);
2258 * With that we have determined the number of bytes in actual use
2259 * by the object. This is the potential offset to the free pointer.
2263 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
2266 * Relocate free pointer after the object if it is not
2267 * permitted to overwrite the first word of the object on
2270 * This is the case if we do RCU, have a constructor or
2271 * destructor or are poisoning the objects.
2274 size
+= sizeof(void *);
2277 #ifdef CONFIG_SLUB_DEBUG
2278 if (flags
& SLAB_STORE_USER
)
2280 * Need to store information about allocs and frees after
2283 size
+= 2 * sizeof(struct track
);
2285 if (flags
& SLAB_RED_ZONE
)
2287 * Add some empty padding so that we can catch
2288 * overwrites from earlier objects rather than let
2289 * tracking information or the free pointer be
2290 * corrupted if an user writes before the start
2293 size
+= sizeof(void *);
2297 * Determine the alignment based on various parameters that the
2298 * user specified and the dynamic determination of cache line size
2301 align
= calculate_alignment(flags
, align
, s
->objsize
);
2304 * SLUB stores one object immediately after another beginning from
2305 * offset 0. In order to align the objects we have to simply size
2306 * each object to conform to the alignment.
2308 size
= ALIGN(size
, align
);
2310 order
= calculate_order(size
);
2317 s
->allocflags
|= __GFP_COMP
;
2319 if (s
->flags
& SLAB_CACHE_DMA
)
2320 s
->allocflags
|= SLUB_DMA
;
2322 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
2323 s
->allocflags
|= __GFP_RECLAIMABLE
;
2326 * Determine the number of objects per slab
2328 s
->oo
= oo_make(order
, size
);
2329 s
->min
= oo_make(get_order(size
), size
);
2330 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
2333 return !!oo_objects(s
->oo
);
2337 static int kmem_cache_open(struct kmem_cache
*s
, gfp_t gfpflags
,
2338 const char *name
, size_t size
,
2339 size_t align
, unsigned long flags
,
2340 void (*ctor
)(struct kmem_cache
*, void *))
2342 memset(s
, 0, kmem_size
);
2347 s
->flags
= kmem_cache_flags(size
, flags
, name
, ctor
);
2349 if (!calculate_sizes(s
))
2354 s
->remote_node_defrag_ratio
= 100;
2356 if (!init_kmem_cache_nodes(s
, gfpflags
& ~SLUB_DMA
))
2359 if (alloc_kmem_cache_cpus(s
, gfpflags
& ~SLUB_DMA
))
2361 free_kmem_cache_nodes(s
);
2363 if (flags
& SLAB_PANIC
)
2364 panic("Cannot create slab %s size=%lu realsize=%u "
2365 "order=%u offset=%u flags=%lx\n",
2366 s
->name
, (unsigned long)size
, s
->size
, oo_order(s
->oo
),
2372 * Check if a given pointer is valid
2374 int kmem_ptr_validate(struct kmem_cache
*s
, const void *object
)
2378 page
= get_object_page(object
);
2380 if (!page
|| s
!= page
->slab
)
2381 /* No slab or wrong slab */
2384 if (!check_valid_pointer(s
, page
, object
))
2388 * We could also check if the object is on the slabs freelist.
2389 * But this would be too expensive and it seems that the main
2390 * purpose of kmem_ptr_valid() is to check if the object belongs
2391 * to a certain slab.
2395 EXPORT_SYMBOL(kmem_ptr_validate
);
2398 * Determine the size of a slab object
2400 unsigned int kmem_cache_size(struct kmem_cache
*s
)
2404 EXPORT_SYMBOL(kmem_cache_size
);
2406 const char *kmem_cache_name(struct kmem_cache
*s
)
2410 EXPORT_SYMBOL(kmem_cache_name
);
2412 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
2415 #ifdef CONFIG_SLUB_DEBUG
2416 void *addr
= page_address(page
);
2418 DECLARE_BITMAP(map
, page
->objects
);
2420 bitmap_zero(map
, page
->objects
);
2421 slab_err(s
, page
, "%s", text
);
2423 for_each_free_object(p
, s
, page
->freelist
)
2424 set_bit(slab_index(p
, s
, addr
), map
);
2426 for_each_object(p
, s
, addr
, page
->objects
) {
2428 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
2429 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
2431 print_tracking(s
, p
);
2439 * Attempt to free all partial slabs on a node.
2441 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
2443 unsigned long flags
;
2444 struct page
*page
, *h
;
2446 spin_lock_irqsave(&n
->list_lock
, flags
);
2447 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
2449 list_del(&page
->lru
);
2450 discard_slab(s
, page
);
2453 list_slab_objects(s
, page
,
2454 "Objects remaining on kmem_cache_close()");
2457 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2461 * Release all resources used by a slab cache.
2463 static inline int kmem_cache_close(struct kmem_cache
*s
)
2469 /* Attempt to free all objects */
2470 free_kmem_cache_cpus(s
);
2471 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2472 struct kmem_cache_node
*n
= get_node(s
, node
);
2475 if (n
->nr_partial
|| slabs_node(s
, node
))
2478 free_kmem_cache_nodes(s
);
2483 * Close a cache and release the kmem_cache structure
2484 * (must be used for caches created using kmem_cache_create)
2486 void kmem_cache_destroy(struct kmem_cache
*s
)
2488 down_write(&slub_lock
);
2492 up_write(&slub_lock
);
2493 if (kmem_cache_close(s
)) {
2494 printk(KERN_ERR
"SLUB %s: %s called for cache that "
2495 "still has objects.\n", s
->name
, __func__
);
2498 sysfs_slab_remove(s
);
2500 up_write(&slub_lock
);
2502 EXPORT_SYMBOL(kmem_cache_destroy
);
2504 /********************************************************************
2506 *******************************************************************/
2508 struct kmem_cache kmalloc_caches
[PAGE_SHIFT
+ 1] __cacheline_aligned
;
2509 EXPORT_SYMBOL(kmalloc_caches
);
2511 static int __init
setup_slub_min_order(char *str
)
2513 get_option(&str
, &slub_min_order
);
2518 __setup("slub_min_order=", setup_slub_min_order
);
2520 static int __init
setup_slub_max_order(char *str
)
2522 get_option(&str
, &slub_max_order
);
2527 __setup("slub_max_order=", setup_slub_max_order
);
2529 static int __init
setup_slub_min_objects(char *str
)
2531 get_option(&str
, &slub_min_objects
);
2536 __setup("slub_min_objects=", setup_slub_min_objects
);
2538 static int __init
setup_slub_nomerge(char *str
)
2544 __setup("slub_nomerge", setup_slub_nomerge
);
2546 static struct kmem_cache
*create_kmalloc_cache(struct kmem_cache
*s
,
2547 const char *name
, int size
, gfp_t gfp_flags
)
2549 unsigned int flags
= 0;
2551 if (gfp_flags
& SLUB_DMA
)
2552 flags
= SLAB_CACHE_DMA
;
2554 down_write(&slub_lock
);
2555 if (!kmem_cache_open(s
, gfp_flags
, name
, size
, ARCH_KMALLOC_MINALIGN
,
2559 list_add(&s
->list
, &slab_caches
);
2560 up_write(&slub_lock
);
2561 if (sysfs_slab_add(s
))
2566 panic("Creation of kmalloc slab %s size=%d failed.\n", name
, size
);
2569 #ifdef CONFIG_ZONE_DMA
2570 static struct kmem_cache
*kmalloc_caches_dma
[PAGE_SHIFT
+ 1];
2572 static void sysfs_add_func(struct work_struct
*w
)
2574 struct kmem_cache
*s
;
2576 down_write(&slub_lock
);
2577 list_for_each_entry(s
, &slab_caches
, list
) {
2578 if (s
->flags
& __SYSFS_ADD_DEFERRED
) {
2579 s
->flags
&= ~__SYSFS_ADD_DEFERRED
;
2583 up_write(&slub_lock
);
2586 static DECLARE_WORK(sysfs_add_work
, sysfs_add_func
);
2588 static noinline
struct kmem_cache
*dma_kmalloc_cache(int index
, gfp_t flags
)
2590 struct kmem_cache
*s
;
2594 s
= kmalloc_caches_dma
[index
];
2598 /* Dynamically create dma cache */
2599 if (flags
& __GFP_WAIT
)
2600 down_write(&slub_lock
);
2602 if (!down_write_trylock(&slub_lock
))
2606 if (kmalloc_caches_dma
[index
])
2609 realsize
= kmalloc_caches
[index
].objsize
;
2610 text
= kasprintf(flags
& ~SLUB_DMA
, "kmalloc_dma-%d",
2611 (unsigned int)realsize
);
2612 s
= kmalloc(kmem_size
, flags
& ~SLUB_DMA
);
2614 if (!s
|| !text
|| !kmem_cache_open(s
, flags
, text
,
2615 realsize
, ARCH_KMALLOC_MINALIGN
,
2616 SLAB_CACHE_DMA
|__SYSFS_ADD_DEFERRED
, NULL
)) {
2622 list_add(&s
->list
, &slab_caches
);
2623 kmalloc_caches_dma
[index
] = s
;
2625 schedule_work(&sysfs_add_work
);
2628 up_write(&slub_lock
);
2630 return kmalloc_caches_dma
[index
];
2635 * Conversion table for small slabs sizes / 8 to the index in the
2636 * kmalloc array. This is necessary for slabs < 192 since we have non power
2637 * of two cache sizes there. The size of larger slabs can be determined using
2640 static s8 size_index
[24] = {
2667 static struct kmem_cache
*get_slab(size_t size
, gfp_t flags
)
2673 return ZERO_SIZE_PTR
;
2675 index
= size_index
[(size
- 1) / 8];
2677 index
= fls(size
- 1);
2679 #ifdef CONFIG_ZONE_DMA
2680 if (unlikely((flags
& SLUB_DMA
)))
2681 return dma_kmalloc_cache(index
, flags
);
2684 return &kmalloc_caches
[index
];
2687 void *__kmalloc(size_t size
, gfp_t flags
)
2689 struct kmem_cache
*s
;
2691 if (unlikely(size
> PAGE_SIZE
))
2692 return kmalloc_large(size
, flags
);
2694 s
= get_slab(size
, flags
);
2696 if (unlikely(ZERO_OR_NULL_PTR(s
)))
2699 return slab_alloc(s
, flags
, -1, __builtin_return_address(0));
2701 EXPORT_SYMBOL(__kmalloc
);
2703 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
2705 struct page
*page
= alloc_pages_node(node
, flags
| __GFP_COMP
,
2709 return page_address(page
);
2715 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
2717 struct kmem_cache
*s
;
2719 if (unlikely(size
> PAGE_SIZE
))
2720 return kmalloc_large_node(size
, flags
, node
);
2722 s
= get_slab(size
, flags
);
2724 if (unlikely(ZERO_OR_NULL_PTR(s
)))
2727 return slab_alloc(s
, flags
, node
, __builtin_return_address(0));
2729 EXPORT_SYMBOL(__kmalloc_node
);
2732 size_t ksize(const void *object
)
2735 struct kmem_cache
*s
;
2737 if (unlikely(object
== ZERO_SIZE_PTR
))
2740 page
= virt_to_head_page(object
);
2742 if (unlikely(!PageSlab(page
)))
2743 return PAGE_SIZE
<< compound_order(page
);
2747 #ifdef CONFIG_SLUB_DEBUG
2749 * Debugging requires use of the padding between object
2750 * and whatever may come after it.
2752 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
2757 * If we have the need to store the freelist pointer
2758 * back there or track user information then we can
2759 * only use the space before that information.
2761 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
2764 * Else we can use all the padding etc for the allocation
2768 EXPORT_SYMBOL(ksize
);
2770 void kfree(const void *x
)
2773 void *object
= (void *)x
;
2775 if (unlikely(ZERO_OR_NULL_PTR(x
)))
2778 page
= virt_to_head_page(x
);
2779 if (unlikely(!PageSlab(page
))) {
2783 slab_free(page
->slab
, page
, object
, __builtin_return_address(0));
2785 EXPORT_SYMBOL(kfree
);
2788 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2789 * the remaining slabs by the number of items in use. The slabs with the
2790 * most items in use come first. New allocations will then fill those up
2791 * and thus they can be removed from the partial lists.
2793 * The slabs with the least items are placed last. This results in them
2794 * being allocated from last increasing the chance that the last objects
2795 * are freed in them.
2797 int kmem_cache_shrink(struct kmem_cache
*s
)
2801 struct kmem_cache_node
*n
;
2804 int objects
= oo_objects(s
->max
);
2805 struct list_head
*slabs_by_inuse
=
2806 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
2807 unsigned long flags
;
2809 if (!slabs_by_inuse
)
2813 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2814 n
= get_node(s
, node
);
2819 for (i
= 0; i
< objects
; i
++)
2820 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
2822 spin_lock_irqsave(&n
->list_lock
, flags
);
2825 * Build lists indexed by the items in use in each slab.
2827 * Note that concurrent frees may occur while we hold the
2828 * list_lock. page->inuse here is the upper limit.
2830 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
2831 if (!page
->inuse
&& slab_trylock(page
)) {
2833 * Must hold slab lock here because slab_free
2834 * may have freed the last object and be
2835 * waiting to release the slab.
2837 list_del(&page
->lru
);
2840 discard_slab(s
, page
);
2842 list_move(&page
->lru
,
2843 slabs_by_inuse
+ page
->inuse
);
2848 * Rebuild the partial list with the slabs filled up most
2849 * first and the least used slabs at the end.
2851 for (i
= objects
- 1; i
>= 0; i
--)
2852 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
2854 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2857 kfree(slabs_by_inuse
);
2860 EXPORT_SYMBOL(kmem_cache_shrink
);
2862 #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2863 static int slab_mem_going_offline_callback(void *arg
)
2865 struct kmem_cache
*s
;
2867 down_read(&slub_lock
);
2868 list_for_each_entry(s
, &slab_caches
, list
)
2869 kmem_cache_shrink(s
);
2870 up_read(&slub_lock
);
2875 static void slab_mem_offline_callback(void *arg
)
2877 struct kmem_cache_node
*n
;
2878 struct kmem_cache
*s
;
2879 struct memory_notify
*marg
= arg
;
2882 offline_node
= marg
->status_change_nid
;
2885 * If the node still has available memory. we need kmem_cache_node
2888 if (offline_node
< 0)
2891 down_read(&slub_lock
);
2892 list_for_each_entry(s
, &slab_caches
, list
) {
2893 n
= get_node(s
, offline_node
);
2896 * if n->nr_slabs > 0, slabs still exist on the node
2897 * that is going down. We were unable to free them,
2898 * and offline_pages() function shoudn't call this
2899 * callback. So, we must fail.
2901 BUG_ON(slabs_node(s
, offline_node
));
2903 s
->node
[offline_node
] = NULL
;
2904 kmem_cache_free(kmalloc_caches
, n
);
2907 up_read(&slub_lock
);
2910 static int slab_mem_going_online_callback(void *arg
)
2912 struct kmem_cache_node
*n
;
2913 struct kmem_cache
*s
;
2914 struct memory_notify
*marg
= arg
;
2915 int nid
= marg
->status_change_nid
;
2919 * If the node's memory is already available, then kmem_cache_node is
2920 * already created. Nothing to do.
2926 * We are bringing a node online. No memory is availabe yet. We must
2927 * allocate a kmem_cache_node structure in order to bring the node
2930 down_read(&slub_lock
);
2931 list_for_each_entry(s
, &slab_caches
, list
) {
2933 * XXX: kmem_cache_alloc_node will fallback to other nodes
2934 * since memory is not yet available from the node that
2937 n
= kmem_cache_alloc(kmalloc_caches
, GFP_KERNEL
);
2942 init_kmem_cache_node(n
);
2946 up_read(&slub_lock
);
2950 static int slab_memory_callback(struct notifier_block
*self
,
2951 unsigned long action
, void *arg
)
2956 case MEM_GOING_ONLINE
:
2957 ret
= slab_mem_going_online_callback(arg
);
2959 case MEM_GOING_OFFLINE
:
2960 ret
= slab_mem_going_offline_callback(arg
);
2963 case MEM_CANCEL_ONLINE
:
2964 slab_mem_offline_callback(arg
);
2967 case MEM_CANCEL_OFFLINE
:
2971 ret
= notifier_from_errno(ret
);
2975 #endif /* CONFIG_MEMORY_HOTPLUG */
2977 /********************************************************************
2978 * Basic setup of slabs
2979 *******************************************************************/
2981 void __init
kmem_cache_init(void)
2990 * Must first have the slab cache available for the allocations of the
2991 * struct kmem_cache_node's. There is special bootstrap code in
2992 * kmem_cache_open for slab_state == DOWN.
2994 create_kmalloc_cache(&kmalloc_caches
[0], "kmem_cache_node",
2995 sizeof(struct kmem_cache_node
), GFP_KERNEL
);
2996 kmalloc_caches
[0].refcount
= -1;
2999 hotplug_memory_notifier(slab_memory_callback
, 1);
3002 /* Able to allocate the per node structures */
3003 slab_state
= PARTIAL
;
3005 /* Caches that are not of the two-to-the-power-of size */
3006 if (KMALLOC_MIN_SIZE
<= 64) {
3007 create_kmalloc_cache(&kmalloc_caches
[1],
3008 "kmalloc-96", 96, GFP_KERNEL
);
3011 if (KMALLOC_MIN_SIZE
<= 128) {
3012 create_kmalloc_cache(&kmalloc_caches
[2],
3013 "kmalloc-192", 192, GFP_KERNEL
);
3017 for (i
= KMALLOC_SHIFT_LOW
; i
<= PAGE_SHIFT
; i
++) {
3018 create_kmalloc_cache(&kmalloc_caches
[i
],
3019 "kmalloc", 1 << i
, GFP_KERNEL
);
3025 * Patch up the size_index table if we have strange large alignment
3026 * requirements for the kmalloc array. This is only the case for
3027 * MIPS it seems. The standard arches will not generate any code here.
3029 * Largest permitted alignment is 256 bytes due to the way we
3030 * handle the index determination for the smaller caches.
3032 * Make sure that nothing crazy happens if someone starts tinkering
3033 * around with ARCH_KMALLOC_MINALIGN
3035 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 256 ||
3036 (KMALLOC_MIN_SIZE
& (KMALLOC_MIN_SIZE
- 1)));
3038 for (i
= 8; i
< KMALLOC_MIN_SIZE
; i
+= 8)
3039 size_index
[(i
- 1) / 8] = KMALLOC_SHIFT_LOW
;
3043 /* Provide the correct kmalloc names now that the caches are up */
3044 for (i
= KMALLOC_SHIFT_LOW
; i
<= PAGE_SHIFT
; i
++)
3045 kmalloc_caches
[i
]. name
=
3046 kasprintf(GFP_KERNEL
, "kmalloc-%d", 1 << i
);
3049 register_cpu_notifier(&slab_notifier
);
3050 kmem_size
= offsetof(struct kmem_cache
, cpu_slab
) +
3051 nr_cpu_ids
* sizeof(struct kmem_cache_cpu
*);
3053 kmem_size
= sizeof(struct kmem_cache
);
3057 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3058 " CPUs=%d, Nodes=%d\n",
3059 caches
, cache_line_size(),
3060 slub_min_order
, slub_max_order
, slub_min_objects
,
3061 nr_cpu_ids
, nr_node_ids
);
3065 * Find a mergeable slab cache
3067 static int slab_unmergeable(struct kmem_cache
*s
)
3069 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3076 * We may have set a slab to be unmergeable during bootstrap.
3078 if (s
->refcount
< 0)
3084 static struct kmem_cache
*find_mergeable(size_t size
,
3085 size_t align
, unsigned long flags
, const char *name
,
3086 void (*ctor
)(struct kmem_cache
*, void *))
3088 struct kmem_cache
*s
;
3090 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3096 size
= ALIGN(size
, sizeof(void *));
3097 align
= calculate_alignment(flags
, align
, size
);
3098 size
= ALIGN(size
, align
);
3099 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3101 list_for_each_entry(s
, &slab_caches
, list
) {
3102 if (slab_unmergeable(s
))
3108 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3111 * Check if alignment is compatible.
3112 * Courtesy of Adrian Drzewiecki
3114 if ((s
->size
& ~(align
- 1)) != s
->size
)
3117 if (s
->size
- size
>= sizeof(void *))
3125 struct kmem_cache
*kmem_cache_create(const char *name
, size_t size
,
3126 size_t align
, unsigned long flags
,
3127 void (*ctor
)(struct kmem_cache
*, void *))
3129 struct kmem_cache
*s
;
3131 down_write(&slub_lock
);
3132 s
= find_mergeable(size
, align
, flags
, name
, ctor
);
3138 * Adjust the object sizes so that we clear
3139 * the complete object on kzalloc.
3141 s
->objsize
= max(s
->objsize
, (int)size
);
3144 * And then we need to update the object size in the
3145 * per cpu structures
3147 for_each_online_cpu(cpu
)
3148 get_cpu_slab(s
, cpu
)->objsize
= s
->objsize
;
3150 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3151 up_write(&slub_lock
);
3153 if (sysfs_slab_alias(s
, name
))
3158 s
= kmalloc(kmem_size
, GFP_KERNEL
);
3160 if (kmem_cache_open(s
, GFP_KERNEL
, name
,
3161 size
, align
, flags
, ctor
)) {
3162 list_add(&s
->list
, &slab_caches
);
3163 up_write(&slub_lock
);
3164 if (sysfs_slab_add(s
))
3170 up_write(&slub_lock
);
3173 if (flags
& SLAB_PANIC
)
3174 panic("Cannot create slabcache %s\n", name
);
3179 EXPORT_SYMBOL(kmem_cache_create
);
3183 * Use the cpu notifier to insure that the cpu slabs are flushed when
3186 static int __cpuinit
slab_cpuup_callback(struct notifier_block
*nfb
,
3187 unsigned long action
, void *hcpu
)
3189 long cpu
= (long)hcpu
;
3190 struct kmem_cache
*s
;
3191 unsigned long flags
;
3194 case CPU_UP_PREPARE
:
3195 case CPU_UP_PREPARE_FROZEN
:
3196 init_alloc_cpu_cpu(cpu
);
3197 down_read(&slub_lock
);
3198 list_for_each_entry(s
, &slab_caches
, list
)
3199 s
->cpu_slab
[cpu
] = alloc_kmem_cache_cpu(s
, cpu
,
3201 up_read(&slub_lock
);
3204 case CPU_UP_CANCELED
:
3205 case CPU_UP_CANCELED_FROZEN
:
3207 case CPU_DEAD_FROZEN
:
3208 down_read(&slub_lock
);
3209 list_for_each_entry(s
, &slab_caches
, list
) {
3210 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
3212 local_irq_save(flags
);
3213 __flush_cpu_slab(s
, cpu
);
3214 local_irq_restore(flags
);
3215 free_kmem_cache_cpu(c
, cpu
);
3216 s
->cpu_slab
[cpu
] = NULL
;
3218 up_read(&slub_lock
);
3226 static struct notifier_block __cpuinitdata slab_notifier
= {
3227 .notifier_call
= slab_cpuup_callback
3232 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, void *caller
)
3234 struct kmem_cache
*s
;
3236 if (unlikely(size
> PAGE_SIZE
))
3237 return kmalloc_large(size
, gfpflags
);
3239 s
= get_slab(size
, gfpflags
);
3241 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3244 return slab_alloc(s
, gfpflags
, -1, caller
);
3247 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3248 int node
, void *caller
)
3250 struct kmem_cache
*s
;
3252 if (unlikely(size
> PAGE_SIZE
))
3253 return kmalloc_large_node(size
, gfpflags
, node
);
3255 s
= get_slab(size
, gfpflags
);
3257 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3260 return slab_alloc(s
, gfpflags
, node
, caller
);
3263 #if (defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)) || defined(CONFIG_SLABINFO)
3264 static unsigned long count_partial(struct kmem_cache_node
*n
,
3265 int (*get_count
)(struct page
*))
3267 unsigned long flags
;
3268 unsigned long x
= 0;
3271 spin_lock_irqsave(&n
->list_lock
, flags
);
3272 list_for_each_entry(page
, &n
->partial
, lru
)
3273 x
+= get_count(page
);
3274 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3278 static int count_inuse(struct page
*page
)
3283 static int count_total(struct page
*page
)
3285 return page
->objects
;
3288 static int count_free(struct page
*page
)
3290 return page
->objects
- page
->inuse
;
3294 #if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
3295 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3299 void *addr
= page_address(page
);
3301 if (!check_slab(s
, page
) ||
3302 !on_freelist(s
, page
, NULL
))
3305 /* Now we know that a valid freelist exists */
3306 bitmap_zero(map
, page
->objects
);
3308 for_each_free_object(p
, s
, page
->freelist
) {
3309 set_bit(slab_index(p
, s
, addr
), map
);
3310 if (!check_object(s
, page
, p
, 0))
3314 for_each_object(p
, s
, addr
, page
->objects
)
3315 if (!test_bit(slab_index(p
, s
, addr
), map
))
3316 if (!check_object(s
, page
, p
, 1))
3321 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
3324 if (slab_trylock(page
)) {
3325 validate_slab(s
, page
, map
);
3328 printk(KERN_INFO
"SLUB %s: Skipped busy slab 0x%p\n",
3331 if (s
->flags
& DEBUG_DEFAULT_FLAGS
) {
3332 if (!SlabDebug(page
))
3333 printk(KERN_ERR
"SLUB %s: SlabDebug not set "
3334 "on slab 0x%p\n", s
->name
, page
);
3336 if (SlabDebug(page
))
3337 printk(KERN_ERR
"SLUB %s: SlabDebug set on "
3338 "slab 0x%p\n", s
->name
, page
);
3342 static int validate_slab_node(struct kmem_cache
*s
,
3343 struct kmem_cache_node
*n
, unsigned long *map
)
3345 unsigned long count
= 0;
3347 unsigned long flags
;
3349 spin_lock_irqsave(&n
->list_lock
, flags
);
3351 list_for_each_entry(page
, &n
->partial
, lru
) {
3352 validate_slab_slab(s
, page
, map
);
3355 if (count
!= n
->nr_partial
)
3356 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
3357 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
3359 if (!(s
->flags
& SLAB_STORE_USER
))
3362 list_for_each_entry(page
, &n
->full
, lru
) {
3363 validate_slab_slab(s
, page
, map
);
3366 if (count
!= atomic_long_read(&n
->nr_slabs
))
3367 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
3368 "counter=%ld\n", s
->name
, count
,
3369 atomic_long_read(&n
->nr_slabs
));
3372 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3376 static long validate_slab_cache(struct kmem_cache
*s
)
3379 unsigned long count
= 0;
3380 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
3381 sizeof(unsigned long), GFP_KERNEL
);
3387 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3388 struct kmem_cache_node
*n
= get_node(s
, node
);
3390 count
+= validate_slab_node(s
, n
, map
);
3396 #ifdef SLUB_RESILIENCY_TEST
3397 static void resiliency_test(void)
3401 printk(KERN_ERR
"SLUB resiliency testing\n");
3402 printk(KERN_ERR
"-----------------------\n");
3403 printk(KERN_ERR
"A. Corruption after allocation\n");
3405 p
= kzalloc(16, GFP_KERNEL
);
3407 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
3408 " 0x12->0x%p\n\n", p
+ 16);
3410 validate_slab_cache(kmalloc_caches
+ 4);
3412 /* Hmmm... The next two are dangerous */
3413 p
= kzalloc(32, GFP_KERNEL
);
3414 p
[32 + sizeof(void *)] = 0x34;
3415 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
3416 " 0x34 -> -0x%p\n", p
);
3418 "If allocated object is overwritten then not detectable\n\n");
3420 validate_slab_cache(kmalloc_caches
+ 5);
3421 p
= kzalloc(64, GFP_KERNEL
);
3422 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
3424 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3427 "If allocated object is overwritten then not detectable\n\n");
3428 validate_slab_cache(kmalloc_caches
+ 6);
3430 printk(KERN_ERR
"\nB. Corruption after free\n");
3431 p
= kzalloc(128, GFP_KERNEL
);
3434 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
3435 validate_slab_cache(kmalloc_caches
+ 7);
3437 p
= kzalloc(256, GFP_KERNEL
);
3440 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3442 validate_slab_cache(kmalloc_caches
+ 8);
3444 p
= kzalloc(512, GFP_KERNEL
);
3447 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
3448 validate_slab_cache(kmalloc_caches
+ 9);
3451 static void resiliency_test(void) {};
3455 * Generate lists of code addresses where slabcache objects are allocated
3460 unsigned long count
;
3473 unsigned long count
;
3474 struct location
*loc
;
3477 static void free_loc_track(struct loc_track
*t
)
3480 free_pages((unsigned long)t
->loc
,
3481 get_order(sizeof(struct location
) * t
->max
));
3484 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
3489 order
= get_order(sizeof(struct location
) * max
);
3491 l
= (void *)__get_free_pages(flags
, order
);
3496 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
3504 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
3505 const struct track
*track
)
3507 long start
, end
, pos
;
3510 unsigned long age
= jiffies
- track
->when
;
3516 pos
= start
+ (end
- start
+ 1) / 2;
3519 * There is nothing at "end". If we end up there
3520 * we need to add something to before end.
3525 caddr
= t
->loc
[pos
].addr
;
3526 if (track
->addr
== caddr
) {
3532 if (age
< l
->min_time
)
3534 if (age
> l
->max_time
)
3537 if (track
->pid
< l
->min_pid
)
3538 l
->min_pid
= track
->pid
;
3539 if (track
->pid
> l
->max_pid
)
3540 l
->max_pid
= track
->pid
;
3542 cpu_set(track
->cpu
, l
->cpus
);
3544 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
3548 if (track
->addr
< caddr
)
3555 * Not found. Insert new tracking element.
3557 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
3563 (t
->count
- pos
) * sizeof(struct location
));
3566 l
->addr
= track
->addr
;
3570 l
->min_pid
= track
->pid
;
3571 l
->max_pid
= track
->pid
;
3572 cpus_clear(l
->cpus
);
3573 cpu_set(track
->cpu
, l
->cpus
);
3574 nodes_clear(l
->nodes
);
3575 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
3579 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
3580 struct page
*page
, enum track_item alloc
)
3582 void *addr
= page_address(page
);
3583 DECLARE_BITMAP(map
, page
->objects
);
3586 bitmap_zero(map
, page
->objects
);
3587 for_each_free_object(p
, s
, page
->freelist
)
3588 set_bit(slab_index(p
, s
, addr
), map
);
3590 for_each_object(p
, s
, addr
, page
->objects
)
3591 if (!test_bit(slab_index(p
, s
, addr
), map
))
3592 add_location(t
, s
, get_track(s
, p
, alloc
));
3595 static int list_locations(struct kmem_cache
*s
, char *buf
,
3596 enum track_item alloc
)
3600 struct loc_track t
= { 0, 0, NULL
};
3603 if (!alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
3605 return sprintf(buf
, "Out of memory\n");
3607 /* Push back cpu slabs */
3610 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3611 struct kmem_cache_node
*n
= get_node(s
, node
);
3612 unsigned long flags
;
3615 if (!atomic_long_read(&n
->nr_slabs
))
3618 spin_lock_irqsave(&n
->list_lock
, flags
);
3619 list_for_each_entry(page
, &n
->partial
, lru
)
3620 process_slab(&t
, s
, page
, alloc
);
3621 list_for_each_entry(page
, &n
->full
, lru
)
3622 process_slab(&t
, s
, page
, alloc
);
3623 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3626 for (i
= 0; i
< t
.count
; i
++) {
3627 struct location
*l
= &t
.loc
[i
];
3629 if (len
> PAGE_SIZE
- 100)
3631 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
3634 len
+= sprint_symbol(buf
+ len
, (unsigned long)l
->addr
);
3636 len
+= sprintf(buf
+ len
, "<not-available>");
3638 if (l
->sum_time
!= l
->min_time
) {
3639 unsigned long remainder
;
3641 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
3643 div_long_long_rem(l
->sum_time
, l
->count
, &remainder
),
3646 len
+= sprintf(buf
+ len
, " age=%ld",
3649 if (l
->min_pid
!= l
->max_pid
)
3650 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
3651 l
->min_pid
, l
->max_pid
);
3653 len
+= sprintf(buf
+ len
, " pid=%ld",
3656 if (num_online_cpus() > 1 && !cpus_empty(l
->cpus
) &&
3657 len
< PAGE_SIZE
- 60) {
3658 len
+= sprintf(buf
+ len
, " cpus=");
3659 len
+= cpulist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
3663 if (num_online_nodes() > 1 && !nodes_empty(l
->nodes
) &&
3664 len
< PAGE_SIZE
- 60) {
3665 len
+= sprintf(buf
+ len
, " nodes=");
3666 len
+= nodelist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
3670 len
+= sprintf(buf
+ len
, "\n");
3675 len
+= sprintf(buf
, "No data\n");
3679 enum slab_stat_type
{
3680 SL_ALL
, /* All slabs */
3681 SL_PARTIAL
, /* Only partially allocated slabs */
3682 SL_CPU
, /* Only slabs used for cpu caches */
3683 SL_OBJECTS
, /* Determine allocated objects not slabs */
3684 SL_TOTAL
/* Determine object capacity not slabs */
3687 #define SO_ALL (1 << SL_ALL)
3688 #define SO_PARTIAL (1 << SL_PARTIAL)
3689 #define SO_CPU (1 << SL_CPU)
3690 #define SO_OBJECTS (1 << SL_OBJECTS)
3691 #define SO_TOTAL (1 << SL_TOTAL)
3693 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
3694 char *buf
, unsigned long flags
)
3696 unsigned long total
= 0;
3699 unsigned long *nodes
;
3700 unsigned long *per_cpu
;
3702 nodes
= kzalloc(2 * sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
3705 per_cpu
= nodes
+ nr_node_ids
;
3707 if (flags
& SO_CPU
) {
3710 for_each_possible_cpu(cpu
) {
3711 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
3713 if (!c
|| c
->node
< 0)
3717 if (flags
& SO_TOTAL
)
3718 x
= c
->page
->objects
;
3719 else if (flags
& SO_OBJECTS
)
3725 nodes
[c
->node
] += x
;
3731 if (flags
& SO_ALL
) {
3732 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3733 struct kmem_cache_node
*n
= get_node(s
, node
);
3735 if (flags
& SO_TOTAL
)
3736 x
= atomic_long_read(&n
->total_objects
);
3737 else if (flags
& SO_OBJECTS
)
3738 x
= atomic_long_read(&n
->total_objects
) -
3739 count_partial(n
, count_free
);
3742 x
= atomic_long_read(&n
->nr_slabs
);
3747 } else if (flags
& SO_PARTIAL
) {
3748 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3749 struct kmem_cache_node
*n
= get_node(s
, node
);
3751 if (flags
& SO_TOTAL
)
3752 x
= count_partial(n
, count_total
);
3753 else if (flags
& SO_OBJECTS
)
3754 x
= count_partial(n
, count_inuse
);
3761 x
= sprintf(buf
, "%lu", total
);
3763 for_each_node_state(node
, N_NORMAL_MEMORY
)
3765 x
+= sprintf(buf
+ x
, " N%d=%lu",
3769 return x
+ sprintf(buf
+ x
, "\n");
3772 static int any_slab_objects(struct kmem_cache
*s
)
3777 for_each_possible_cpu(cpu
) {
3778 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
3784 for_each_online_node(node
) {
3785 struct kmem_cache_node
*n
= get_node(s
, node
);
3790 if (n
->nr_partial
|| atomic_long_read(&n
->nr_slabs
))
3796 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3797 #define to_slab(n) container_of(n, struct kmem_cache, kobj);
3799 struct slab_attribute
{
3800 struct attribute attr
;
3801 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
3802 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
3805 #define SLAB_ATTR_RO(_name) \
3806 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3808 #define SLAB_ATTR(_name) \
3809 static struct slab_attribute _name##_attr = \
3810 __ATTR(_name, 0644, _name##_show, _name##_store)
3812 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
3814 return sprintf(buf
, "%d\n", s
->size
);
3816 SLAB_ATTR_RO(slab_size
);
3818 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
3820 return sprintf(buf
, "%d\n", s
->align
);
3822 SLAB_ATTR_RO(align
);
3824 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
3826 return sprintf(buf
, "%d\n", s
->objsize
);
3828 SLAB_ATTR_RO(object_size
);
3830 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
3832 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
3834 SLAB_ATTR_RO(objs_per_slab
);
3836 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
3838 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
3840 SLAB_ATTR_RO(order
);
3842 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
3845 int n
= sprint_symbol(buf
, (unsigned long)s
->ctor
);
3847 return n
+ sprintf(buf
+ n
, "\n");
3853 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
3855 return sprintf(buf
, "%d\n", s
->refcount
- 1);
3857 SLAB_ATTR_RO(aliases
);
3859 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
3861 return show_slab_objects(s
, buf
, SO_ALL
);
3863 SLAB_ATTR_RO(slabs
);
3865 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
3867 return show_slab_objects(s
, buf
, SO_PARTIAL
);
3869 SLAB_ATTR_RO(partial
);
3871 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
3873 return show_slab_objects(s
, buf
, SO_CPU
);
3875 SLAB_ATTR_RO(cpu_slabs
);
3877 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
3879 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
3881 SLAB_ATTR_RO(objects
);
3883 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
3885 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
3887 SLAB_ATTR_RO(objects_partial
);
3889 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
3891 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
3893 SLAB_ATTR_RO(total_objects
);
3895 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
3897 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
3900 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
3901 const char *buf
, size_t length
)
3903 s
->flags
&= ~SLAB_DEBUG_FREE
;
3905 s
->flags
|= SLAB_DEBUG_FREE
;
3908 SLAB_ATTR(sanity_checks
);
3910 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
3912 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
3915 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
3918 s
->flags
&= ~SLAB_TRACE
;
3920 s
->flags
|= SLAB_TRACE
;
3925 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
3927 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
3930 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
3931 const char *buf
, size_t length
)
3933 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
3935 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
3938 SLAB_ATTR(reclaim_account
);
3940 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
3942 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
3944 SLAB_ATTR_RO(hwcache_align
);
3946 #ifdef CONFIG_ZONE_DMA
3947 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
3949 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
3951 SLAB_ATTR_RO(cache_dma
);
3954 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
3956 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
3958 SLAB_ATTR_RO(destroy_by_rcu
);
3960 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
3962 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
3965 static ssize_t
red_zone_store(struct kmem_cache
*s
,
3966 const char *buf
, size_t length
)
3968 if (any_slab_objects(s
))
3971 s
->flags
&= ~SLAB_RED_ZONE
;
3973 s
->flags
|= SLAB_RED_ZONE
;
3977 SLAB_ATTR(red_zone
);
3979 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
3981 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
3984 static ssize_t
poison_store(struct kmem_cache
*s
,
3985 const char *buf
, size_t length
)
3987 if (any_slab_objects(s
))
3990 s
->flags
&= ~SLAB_POISON
;
3992 s
->flags
|= SLAB_POISON
;
3998 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4000 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4003 static ssize_t
store_user_store(struct kmem_cache
*s
,
4004 const char *buf
, size_t length
)
4006 if (any_slab_objects(s
))
4009 s
->flags
&= ~SLAB_STORE_USER
;
4011 s
->flags
|= SLAB_STORE_USER
;
4015 SLAB_ATTR(store_user
);
4017 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4022 static ssize_t
validate_store(struct kmem_cache
*s
,
4023 const char *buf
, size_t length
)
4027 if (buf
[0] == '1') {
4028 ret
= validate_slab_cache(s
);
4034 SLAB_ATTR(validate
);
4036 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4041 static ssize_t
shrink_store(struct kmem_cache
*s
,
4042 const char *buf
, size_t length
)
4044 if (buf
[0] == '1') {
4045 int rc
= kmem_cache_shrink(s
);
4055 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4057 if (!(s
->flags
& SLAB_STORE_USER
))
4059 return list_locations(s
, buf
, TRACK_ALLOC
);
4061 SLAB_ATTR_RO(alloc_calls
);
4063 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4065 if (!(s
->flags
& SLAB_STORE_USER
))
4067 return list_locations(s
, buf
, TRACK_FREE
);
4069 SLAB_ATTR_RO(free_calls
);
4072 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4074 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4077 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4078 const char *buf
, size_t length
)
4080 int n
= simple_strtoul(buf
, NULL
, 10);
4083 s
->remote_node_defrag_ratio
= n
* 10;
4086 SLAB_ATTR(remote_node_defrag_ratio
);
4089 #ifdef CONFIG_SLUB_STATS
4090 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4092 unsigned long sum
= 0;
4095 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4100 for_each_online_cpu(cpu
) {
4101 unsigned x
= get_cpu_slab(s
, cpu
)->stat
[si
];
4107 len
= sprintf(buf
, "%lu", sum
);
4110 for_each_online_cpu(cpu
) {
4111 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4112 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4116 return len
+ sprintf(buf
+ len
, "\n");
4119 #define STAT_ATTR(si, text) \
4120 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4122 return show_stat(s, buf, si); \
4124 SLAB_ATTR_RO(text); \
4126 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4127 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4128 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4129 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4130 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4131 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4132 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4133 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4134 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4135 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4136 STAT_ATTR(FREE_SLAB
, free_slab
);
4137 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4138 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4139 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4140 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4141 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4142 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4143 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4146 static struct attribute
*slab_attrs
[] = {
4147 &slab_size_attr
.attr
,
4148 &object_size_attr
.attr
,
4149 &objs_per_slab_attr
.attr
,
4152 &objects_partial_attr
.attr
,
4153 &total_objects_attr
.attr
,
4156 &cpu_slabs_attr
.attr
,
4160 &sanity_checks_attr
.attr
,
4162 &hwcache_align_attr
.attr
,
4163 &reclaim_account_attr
.attr
,
4164 &destroy_by_rcu_attr
.attr
,
4165 &red_zone_attr
.attr
,
4167 &store_user_attr
.attr
,
4168 &validate_attr
.attr
,
4170 &alloc_calls_attr
.attr
,
4171 &free_calls_attr
.attr
,
4172 #ifdef CONFIG_ZONE_DMA
4173 &cache_dma_attr
.attr
,
4176 &remote_node_defrag_ratio_attr
.attr
,
4178 #ifdef CONFIG_SLUB_STATS
4179 &alloc_fastpath_attr
.attr
,
4180 &alloc_slowpath_attr
.attr
,
4181 &free_fastpath_attr
.attr
,
4182 &free_slowpath_attr
.attr
,
4183 &free_frozen_attr
.attr
,
4184 &free_add_partial_attr
.attr
,
4185 &free_remove_partial_attr
.attr
,
4186 &alloc_from_partial_attr
.attr
,
4187 &alloc_slab_attr
.attr
,
4188 &alloc_refill_attr
.attr
,
4189 &free_slab_attr
.attr
,
4190 &cpuslab_flush_attr
.attr
,
4191 &deactivate_full_attr
.attr
,
4192 &deactivate_empty_attr
.attr
,
4193 &deactivate_to_head_attr
.attr
,
4194 &deactivate_to_tail_attr
.attr
,
4195 &deactivate_remote_frees_attr
.attr
,
4196 &order_fallback_attr
.attr
,
4201 static struct attribute_group slab_attr_group
= {
4202 .attrs
= slab_attrs
,
4205 static ssize_t
slab_attr_show(struct kobject
*kobj
,
4206 struct attribute
*attr
,
4209 struct slab_attribute
*attribute
;
4210 struct kmem_cache
*s
;
4213 attribute
= to_slab_attr(attr
);
4216 if (!attribute
->show
)
4219 err
= attribute
->show(s
, buf
);
4224 static ssize_t
slab_attr_store(struct kobject
*kobj
,
4225 struct attribute
*attr
,
4226 const char *buf
, size_t len
)
4228 struct slab_attribute
*attribute
;
4229 struct kmem_cache
*s
;
4232 attribute
= to_slab_attr(attr
);
4235 if (!attribute
->store
)
4238 err
= attribute
->store(s
, buf
, len
);
4243 static void kmem_cache_release(struct kobject
*kobj
)
4245 struct kmem_cache
*s
= to_slab(kobj
);
4250 static struct sysfs_ops slab_sysfs_ops
= {
4251 .show
= slab_attr_show
,
4252 .store
= slab_attr_store
,
4255 static struct kobj_type slab_ktype
= {
4256 .sysfs_ops
= &slab_sysfs_ops
,
4257 .release
= kmem_cache_release
4260 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
4262 struct kobj_type
*ktype
= get_ktype(kobj
);
4264 if (ktype
== &slab_ktype
)
4269 static struct kset_uevent_ops slab_uevent_ops
= {
4270 .filter
= uevent_filter
,
4273 static struct kset
*slab_kset
;
4275 #define ID_STR_LENGTH 64
4277 /* Create a unique string id for a slab cache:
4279 * Format :[flags-]size
4281 static char *create_unique_id(struct kmem_cache
*s
)
4283 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
4290 * First flags affecting slabcache operations. We will only
4291 * get here for aliasable slabs so we do not need to support
4292 * too many flags. The flags here must cover all flags that
4293 * are matched during merging to guarantee that the id is
4296 if (s
->flags
& SLAB_CACHE_DMA
)
4298 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
4300 if (s
->flags
& SLAB_DEBUG_FREE
)
4304 p
+= sprintf(p
, "%07d", s
->size
);
4305 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
4309 static int sysfs_slab_add(struct kmem_cache
*s
)
4315 if (slab_state
< SYSFS
)
4316 /* Defer until later */
4319 unmergeable
= slab_unmergeable(s
);
4322 * Slabcache can never be merged so we can use the name proper.
4323 * This is typically the case for debug situations. In that
4324 * case we can catch duplicate names easily.
4326 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
4330 * Create a unique name for the slab as a target
4333 name
= create_unique_id(s
);
4336 s
->kobj
.kset
= slab_kset
;
4337 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, name
);
4339 kobject_put(&s
->kobj
);
4343 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
4346 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
4348 /* Setup first alias */
4349 sysfs_slab_alias(s
, s
->name
);
4355 static void sysfs_slab_remove(struct kmem_cache
*s
)
4357 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
4358 kobject_del(&s
->kobj
);
4359 kobject_put(&s
->kobj
);
4363 * Need to buffer aliases during bootup until sysfs becomes
4364 * available lest we loose that information.
4366 struct saved_alias
{
4367 struct kmem_cache
*s
;
4369 struct saved_alias
*next
;
4372 static struct saved_alias
*alias_list
;
4374 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
4376 struct saved_alias
*al
;
4378 if (slab_state
== SYSFS
) {
4380 * If we have a leftover link then remove it.
4382 sysfs_remove_link(&slab_kset
->kobj
, name
);
4383 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
4386 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
4392 al
->next
= alias_list
;
4397 static int __init
slab_sysfs_init(void)
4399 struct kmem_cache
*s
;
4402 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
4404 printk(KERN_ERR
"Cannot register slab subsystem.\n");
4410 list_for_each_entry(s
, &slab_caches
, list
) {
4411 err
= sysfs_slab_add(s
);
4413 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
4414 " to sysfs\n", s
->name
);
4417 while (alias_list
) {
4418 struct saved_alias
*al
= alias_list
;
4420 alias_list
= alias_list
->next
;
4421 err
= sysfs_slab_alias(al
->s
, al
->name
);
4423 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
4424 " %s to sysfs\n", s
->name
);
4432 __initcall(slab_sysfs_init
);
4436 * The /proc/slabinfo ABI
4438 #ifdef CONFIG_SLABINFO
4440 ssize_t
slabinfo_write(struct file
*file
, const char __user
* buffer
,
4441 size_t count
, loff_t
*ppos
)
4447 static void print_slabinfo_header(struct seq_file
*m
)
4449 seq_puts(m
, "slabinfo - version: 2.1\n");
4450 seq_puts(m
, "# name <active_objs> <num_objs> <objsize> "
4451 "<objperslab> <pagesperslab>");
4452 seq_puts(m
, " : tunables <limit> <batchcount> <sharedfactor>");
4453 seq_puts(m
, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4457 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
4461 down_read(&slub_lock
);
4463 print_slabinfo_header(m
);
4465 return seq_list_start(&slab_caches
, *pos
);
4468 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4470 return seq_list_next(p
, &slab_caches
, pos
);
4473 static void s_stop(struct seq_file
*m
, void *p
)
4475 up_read(&slub_lock
);
4478 static int s_show(struct seq_file
*m
, void *p
)
4480 unsigned long nr_partials
= 0;
4481 unsigned long nr_slabs
= 0;
4482 unsigned long nr_inuse
= 0;
4483 unsigned long nr_objs
= 0;
4484 unsigned long nr_free
= 0;
4485 struct kmem_cache
*s
;
4488 s
= list_entry(p
, struct kmem_cache
, list
);
4490 for_each_online_node(node
) {
4491 struct kmem_cache_node
*n
= get_node(s
, node
);
4496 nr_partials
+= n
->nr_partial
;
4497 nr_slabs
+= atomic_long_read(&n
->nr_slabs
);
4498 nr_objs
+= atomic_long_read(&n
->total_objects
);
4499 nr_free
+= count_partial(n
, count_free
);
4502 nr_inuse
= nr_objs
- nr_free
;
4504 seq_printf(m
, "%-17s %6lu %6lu %6u %4u %4d", s
->name
, nr_inuse
,
4505 nr_objs
, s
->size
, oo_objects(s
->oo
),
4506 (1 << oo_order(s
->oo
)));
4507 seq_printf(m
, " : tunables %4u %4u %4u", 0, 0, 0);
4508 seq_printf(m
, " : slabdata %6lu %6lu %6lu", nr_slabs
, nr_slabs
,
4514 const struct seq_operations slabinfo_op
= {
4521 #endif /* CONFIG_SLABINFO */