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
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/proc_fs.h>
18 #include <linux/seq_file.h>
19 #include <linux/cpu.h>
20 #include <linux/cpuset.h>
21 #include <linux/mempolicy.h>
22 #include <linux/ctype.h>
23 #include <linux/debugobjects.h>
24 #include <linux/kallsyms.h>
25 #include <linux/memory.h>
26 #include <linux/math64.h>
27 #include <linux/fault-inject.h>
34 * The slab_lock protects operations on the object of a particular
35 * slab and its metadata in the page struct. If the slab lock
36 * has been taken then no allocations nor frees can be performed
37 * on the objects in the slab nor can the slab be added or removed
38 * from the partial or full lists since this would mean modifying
39 * the page_struct of the slab.
41 * The list_lock protects the partial and full list on each node and
42 * the partial slab counter. If taken then no new slabs may be added or
43 * removed from the lists nor make the number of partial slabs be modified.
44 * (Note that the total number of slabs is an atomic value that may be
45 * modified without taking the list lock).
47 * The list_lock is a centralized lock and thus we avoid taking it as
48 * much as possible. As long as SLUB does not have to handle partial
49 * slabs, operations can continue without any centralized lock. F.e.
50 * allocating a long series of objects that fill up slabs does not require
53 * The lock order is sometimes inverted when we are trying to get a slab
54 * off a list. We take the list_lock and then look for a page on the list
55 * to use. While we do that objects in the slabs may be freed. We can
56 * only operate on the slab if we have also taken the slab_lock. So we use
57 * a slab_trylock() on the slab. If trylock was successful then no frees
58 * can occur anymore and we can use the slab for allocations etc. If the
59 * slab_trylock() does not succeed then frees are in progress in the slab and
60 * we must stay away from it for a while since we may cause a bouncing
61 * cacheline if we try to acquire the lock. So go onto the next slab.
62 * If all pages are busy then we may allocate a new slab instead of reusing
63 * a partial slab. A new slab has noone operating on it and thus there is
64 * no danger of cacheline contention.
66 * Interrupts are disabled during allocation and deallocation in order to
67 * make the slab allocator safe to use in the context of an irq. In addition
68 * interrupts are disabled to ensure that the processor does not change
69 * while handling per_cpu slabs, due to kernel preemption.
71 * SLUB assigns one slab for allocation to each processor.
72 * Allocations only occur from these slabs called cpu slabs.
74 * Slabs with free elements are kept on a partial list and during regular
75 * operations no list for full slabs is used. If an object in a full slab is
76 * freed then the slab will show up again on the partial lists.
77 * We track full slabs for debugging purposes though because otherwise we
78 * cannot scan all objects.
80 * Slabs are freed when they become empty. Teardown and setup is
81 * minimal so we rely on the page allocators per cpu caches for
82 * fast frees and allocs.
84 * Overloading of page flags that are otherwise used for LRU management.
86 * PageActive The slab is frozen and exempt from list processing.
87 * This means that the slab is dedicated to a purpose
88 * such as satisfying allocations for a specific
89 * processor. Objects may be freed in the slab while
90 * it is frozen but slab_free will then skip the usual
91 * list operations. It is up to the processor holding
92 * the slab to integrate the slab into the slab lists
93 * when the slab is no longer needed.
95 * One use of this flag is to mark slabs that are
96 * used for allocations. Then such a slab becomes a cpu
97 * slab. The cpu slab may be equipped with an additional
98 * freelist that allows lockless access to
99 * free objects in addition to the regular freelist
100 * that requires the slab lock.
102 * PageError Slab requires special handling due to debug
103 * options set. This moves slab handling out of
104 * the fast path and disables lockless freelists.
107 #ifdef CONFIG_SLUB_DEBUG
114 * Issues still to be resolved:
116 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
118 * - Variable sizing of the per node arrays
121 /* Enable to test recovery from slab corruption on boot */
122 #undef SLUB_RESILIENCY_TEST
125 * Mininum number of partial slabs. These will be left on the partial
126 * lists even if they are empty. kmem_cache_shrink may reclaim them.
128 #define MIN_PARTIAL 5
131 * Maximum number of desirable partial slabs.
132 * The existence of more partial slabs makes kmem_cache_shrink
133 * sort the partial list by the number of objects in the.
135 #define MAX_PARTIAL 10
137 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
138 SLAB_POISON | SLAB_STORE_USER)
141 * Set of flags that will prevent slab merging
143 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
144 SLAB_TRACE | SLAB_DESTROY_BY_RCU)
146 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
149 #ifndef ARCH_KMALLOC_MINALIGN
150 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
153 #ifndef ARCH_SLAB_MINALIGN
154 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
158 #define OO_MASK ((1 << OO_SHIFT) - 1)
159 #define MAX_OBJS_PER_PAGE 65535 /* since page.objects is u16 */
161 /* Internal SLUB flags */
162 #define __OBJECT_POISON 0x80000000 /* Poison object */
163 #define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
165 static int kmem_size
= sizeof(struct kmem_cache
);
168 static struct notifier_block slab_notifier
;
172 DOWN
, /* No slab functionality available */
173 PARTIAL
, /* kmem_cache_open() works but kmalloc does not */
174 UP
, /* Everything works but does not show up in sysfs */
178 /* A list of all slab caches on the system */
179 static DECLARE_RWSEM(slub_lock
);
180 static LIST_HEAD(slab_caches
);
183 * Tracking user of a slab.
186 unsigned long addr
; /* Called from address */
187 int cpu
; /* Was running on cpu */
188 int pid
; /* Pid context */
189 unsigned long when
; /* When did the operation occur */
192 enum track_item
{ TRACK_ALLOC
, TRACK_FREE
};
194 #ifdef CONFIG_SLUB_DEBUG
195 static int sysfs_slab_add(struct kmem_cache
*);
196 static int sysfs_slab_alias(struct kmem_cache
*, const char *);
197 static void sysfs_slab_remove(struct kmem_cache
*);
200 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
201 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
203 static inline void sysfs_slab_remove(struct kmem_cache
*s
)
210 static inline void stat(struct kmem_cache_cpu
*c
, enum stat_item si
)
212 #ifdef CONFIG_SLUB_STATS
217 /********************************************************************
218 * Core slab cache functions
219 *******************************************************************/
221 int slab_is_available(void)
223 return slab_state
>= UP
;
226 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
229 return s
->node
[node
];
231 return &s
->local_node
;
235 static inline struct kmem_cache_cpu
*get_cpu_slab(struct kmem_cache
*s
, int cpu
)
238 return s
->cpu_slab
[cpu
];
244 /* Verify that a pointer has an address that is valid within a slab page */
245 static inline int check_valid_pointer(struct kmem_cache
*s
,
246 struct page
*page
, const void *object
)
253 base
= page_address(page
);
254 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
255 (object
- base
) % s
->size
) {
263 * Slow version of get and set free pointer.
265 * This version requires touching the cache lines of kmem_cache which
266 * we avoid to do in the fast alloc free paths. There we obtain the offset
267 * from the page struct.
269 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
271 return *(void **)(object
+ s
->offset
);
274 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
276 *(void **)(object
+ s
->offset
) = fp
;
279 /* Loop over all objects in a slab */
280 #define for_each_object(__p, __s, __addr, __objects) \
281 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
285 #define for_each_free_object(__p, __s, __free) \
286 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
288 /* Determine object index from a given position */
289 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
291 return (p
- addr
) / s
->size
;
294 static inline struct kmem_cache_order_objects
oo_make(int order
,
297 struct kmem_cache_order_objects x
= {
298 (order
<< OO_SHIFT
) + (PAGE_SIZE
<< order
) / size
304 static inline int oo_order(struct kmem_cache_order_objects x
)
306 return x
.x
>> OO_SHIFT
;
309 static inline int oo_objects(struct kmem_cache_order_objects x
)
311 return x
.x
& OO_MASK
;
314 #ifdef CONFIG_SLUB_DEBUG
318 #ifdef CONFIG_SLUB_DEBUG_ON
319 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
321 static int slub_debug
;
324 static char *slub_debug_slabs
;
329 static void print_section(char *text
, u8
*addr
, unsigned int length
)
337 for (i
= 0; i
< length
; i
++) {
339 printk(KERN_ERR
"%8s 0x%p: ", text
, addr
+ i
);
342 printk(KERN_CONT
" %02x", addr
[i
]);
344 ascii
[offset
] = isgraph(addr
[i
]) ? addr
[i
] : '.';
346 printk(KERN_CONT
" %s\n", ascii
);
353 printk(KERN_CONT
" ");
357 printk(KERN_CONT
" %s\n", ascii
);
361 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
362 enum track_item alloc
)
367 p
= object
+ s
->offset
+ sizeof(void *);
369 p
= object
+ s
->inuse
;
374 static void set_track(struct kmem_cache
*s
, void *object
,
375 enum track_item alloc
, unsigned long addr
)
380 p
= object
+ s
->offset
+ sizeof(void *);
382 p
= object
+ s
->inuse
;
387 p
->cpu
= smp_processor_id();
388 p
->pid
= current
->pid
;
391 memset(p
, 0, sizeof(struct track
));
394 static void init_tracking(struct kmem_cache
*s
, void *object
)
396 if (!(s
->flags
& SLAB_STORE_USER
))
399 set_track(s
, object
, TRACK_FREE
, 0UL);
400 set_track(s
, object
, TRACK_ALLOC
, 0UL);
403 static void print_track(const char *s
, struct track
*t
)
408 printk(KERN_ERR
"INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
409 s
, (void *)t
->addr
, jiffies
- t
->when
, t
->cpu
, t
->pid
);
412 static void print_tracking(struct kmem_cache
*s
, void *object
)
414 if (!(s
->flags
& SLAB_STORE_USER
))
417 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
418 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
421 static void print_page_info(struct page
*page
)
423 printk(KERN_ERR
"INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
424 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
428 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
434 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
436 printk(KERN_ERR
"========================================"
437 "=====================================\n");
438 printk(KERN_ERR
"BUG %s: %s\n", s
->name
, buf
);
439 printk(KERN_ERR
"----------------------------------------"
440 "-------------------------------------\n\n");
443 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
449 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
451 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
454 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
456 unsigned int off
; /* Offset of last byte */
457 u8
*addr
= page_address(page
);
459 print_tracking(s
, p
);
461 print_page_info(page
);
463 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
464 p
, p
- addr
, get_freepointer(s
, p
));
467 print_section("Bytes b4", p
- 16, 16);
469 print_section("Object", p
, min_t(unsigned long, s
->objsize
, PAGE_SIZE
));
471 if (s
->flags
& SLAB_RED_ZONE
)
472 print_section("Redzone", p
+ s
->objsize
,
473 s
->inuse
- s
->objsize
);
476 off
= s
->offset
+ sizeof(void *);
480 if (s
->flags
& SLAB_STORE_USER
)
481 off
+= 2 * sizeof(struct track
);
484 /* Beginning of the filler is the free pointer */
485 print_section("Padding", p
+ off
, s
->size
- off
);
490 static void object_err(struct kmem_cache
*s
, struct page
*page
,
491 u8
*object
, char *reason
)
493 slab_bug(s
, "%s", reason
);
494 print_trailer(s
, page
, object
);
497 static void slab_err(struct kmem_cache
*s
, struct page
*page
, char *fmt
, ...)
503 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
505 slab_bug(s
, "%s", buf
);
506 print_page_info(page
);
510 static void init_object(struct kmem_cache
*s
, void *object
, int active
)
514 if (s
->flags
& __OBJECT_POISON
) {
515 memset(p
, POISON_FREE
, s
->objsize
- 1);
516 p
[s
->objsize
- 1] = POISON_END
;
519 if (s
->flags
& SLAB_RED_ZONE
)
520 memset(p
+ s
->objsize
,
521 active
? SLUB_RED_ACTIVE
: SLUB_RED_INACTIVE
,
522 s
->inuse
- s
->objsize
);
525 static u8
*check_bytes(u8
*start
, unsigned int value
, unsigned int bytes
)
528 if (*start
!= (u8
)value
)
536 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
537 void *from
, void *to
)
539 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
540 memset(from
, data
, to
- from
);
543 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
544 u8
*object
, char *what
,
545 u8
*start
, unsigned int value
, unsigned int bytes
)
550 fault
= check_bytes(start
, value
, bytes
);
555 while (end
> fault
&& end
[-1] == value
)
558 slab_bug(s
, "%s overwritten", what
);
559 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
560 fault
, end
- 1, fault
[0], value
);
561 print_trailer(s
, page
, object
);
563 restore_bytes(s
, what
, value
, fault
, end
);
571 * Bytes of the object to be managed.
572 * If the freepointer may overlay the object then the free
573 * pointer is the first word of the object.
575 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
578 * object + s->objsize
579 * Padding to reach word boundary. This is also used for Redzoning.
580 * Padding is extended by another word if Redzoning is enabled and
583 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
584 * 0xcc (RED_ACTIVE) for objects in use.
587 * Meta data starts here.
589 * A. Free pointer (if we cannot overwrite object on free)
590 * B. Tracking data for SLAB_STORE_USER
591 * C. Padding to reach required alignment boundary or at mininum
592 * one word if debugging is on to be able to detect writes
593 * before the word boundary.
595 * Padding is done using 0x5a (POISON_INUSE)
598 * Nothing is used beyond s->size.
600 * If slabcaches are merged then the objsize and inuse boundaries are mostly
601 * ignored. And therefore no slab options that rely on these boundaries
602 * may be used with merged slabcaches.
605 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
607 unsigned long off
= s
->inuse
; /* The end of info */
610 /* Freepointer is placed after the object. */
611 off
+= sizeof(void *);
613 if (s
->flags
& SLAB_STORE_USER
)
614 /* We also have user information there */
615 off
+= 2 * sizeof(struct track
);
620 return check_bytes_and_report(s
, page
, p
, "Object padding",
621 p
+ off
, POISON_INUSE
, s
->size
- off
);
624 /* Check the pad bytes at the end of a slab page */
625 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
633 if (!(s
->flags
& SLAB_POISON
))
636 start
= page_address(page
);
637 length
= (PAGE_SIZE
<< compound_order(page
));
638 end
= start
+ length
;
639 remainder
= length
% s
->size
;
643 fault
= check_bytes(end
- remainder
, POISON_INUSE
, remainder
);
646 while (end
> fault
&& end
[-1] == POISON_INUSE
)
649 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
650 print_section("Padding", end
- remainder
, remainder
);
652 restore_bytes(s
, "slab padding", POISON_INUSE
, start
, end
);
656 static int check_object(struct kmem_cache
*s
, struct page
*page
,
657 void *object
, int active
)
660 u8
*endobject
= object
+ s
->objsize
;
662 if (s
->flags
& SLAB_RED_ZONE
) {
664 active
? SLUB_RED_ACTIVE
: SLUB_RED_INACTIVE
;
666 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
667 endobject
, red
, s
->inuse
- s
->objsize
))
670 if ((s
->flags
& SLAB_POISON
) && s
->objsize
< s
->inuse
) {
671 check_bytes_and_report(s
, page
, p
, "Alignment padding",
672 endobject
, POISON_INUSE
, s
->inuse
- s
->objsize
);
676 if (s
->flags
& SLAB_POISON
) {
677 if (!active
&& (s
->flags
& __OBJECT_POISON
) &&
678 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
679 POISON_FREE
, s
->objsize
- 1) ||
680 !check_bytes_and_report(s
, page
, p
, "Poison",
681 p
+ s
->objsize
- 1, POISON_END
, 1)))
684 * check_pad_bytes cleans up on its own.
686 check_pad_bytes(s
, page
, p
);
689 if (!s
->offset
&& active
)
691 * Object and freepointer overlap. Cannot check
692 * freepointer while object is allocated.
696 /* Check free pointer validity */
697 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
698 object_err(s
, page
, p
, "Freepointer corrupt");
700 * No choice but to zap it and thus lose the remainder
701 * of the free objects in this slab. May cause
702 * another error because the object count is now wrong.
704 set_freepointer(s
, p
, NULL
);
710 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
714 VM_BUG_ON(!irqs_disabled());
716 if (!PageSlab(page
)) {
717 slab_err(s
, page
, "Not a valid slab page");
721 maxobj
= (PAGE_SIZE
<< compound_order(page
)) / s
->size
;
722 if (page
->objects
> maxobj
) {
723 slab_err(s
, page
, "objects %u > max %u",
724 s
->name
, page
->objects
, maxobj
);
727 if (page
->inuse
> page
->objects
) {
728 slab_err(s
, page
, "inuse %u > max %u",
729 s
->name
, page
->inuse
, page
->objects
);
732 /* Slab_pad_check fixes things up after itself */
733 slab_pad_check(s
, page
);
738 * Determine if a certain object on a page is on the freelist. Must hold the
739 * slab lock to guarantee that the chains are in a consistent state.
741 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
744 void *fp
= page
->freelist
;
746 unsigned long max_objects
;
748 while (fp
&& nr
<= page
->objects
) {
751 if (!check_valid_pointer(s
, page
, fp
)) {
753 object_err(s
, page
, object
,
754 "Freechain corrupt");
755 set_freepointer(s
, object
, NULL
);
758 slab_err(s
, page
, "Freepointer corrupt");
759 page
->freelist
= NULL
;
760 page
->inuse
= page
->objects
;
761 slab_fix(s
, "Freelist cleared");
767 fp
= get_freepointer(s
, object
);
771 max_objects
= (PAGE_SIZE
<< compound_order(page
)) / s
->size
;
772 if (max_objects
> MAX_OBJS_PER_PAGE
)
773 max_objects
= MAX_OBJS_PER_PAGE
;
775 if (page
->objects
!= max_objects
) {
776 slab_err(s
, page
, "Wrong number of objects. Found %d but "
777 "should be %d", page
->objects
, max_objects
);
778 page
->objects
= max_objects
;
779 slab_fix(s
, "Number of objects adjusted.");
781 if (page
->inuse
!= page
->objects
- nr
) {
782 slab_err(s
, page
, "Wrong object count. Counter is %d but "
783 "counted were %d", page
->inuse
, page
->objects
- nr
);
784 page
->inuse
= page
->objects
- nr
;
785 slab_fix(s
, "Object count adjusted.");
787 return search
== NULL
;
790 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
,
793 if (s
->flags
& SLAB_TRACE
) {
794 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
796 alloc
? "alloc" : "free",
801 print_section("Object", (void *)object
, s
->objsize
);
808 * Tracking of fully allocated slabs for debugging purposes.
810 static void add_full(struct kmem_cache_node
*n
, struct page
*page
)
812 spin_lock(&n
->list_lock
);
813 list_add(&page
->lru
, &n
->full
);
814 spin_unlock(&n
->list_lock
);
817 static void remove_full(struct kmem_cache
*s
, struct page
*page
)
819 struct kmem_cache_node
*n
;
821 if (!(s
->flags
& SLAB_STORE_USER
))
824 n
= get_node(s
, page_to_nid(page
));
826 spin_lock(&n
->list_lock
);
827 list_del(&page
->lru
);
828 spin_unlock(&n
->list_lock
);
831 /* Tracking of the number of slabs for debugging purposes */
832 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
834 struct kmem_cache_node
*n
= get_node(s
, node
);
836 return atomic_long_read(&n
->nr_slabs
);
839 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
841 struct kmem_cache_node
*n
= get_node(s
, node
);
844 * May be called early in order to allocate a slab for the
845 * kmem_cache_node structure. Solve the chicken-egg
846 * dilemma by deferring the increment of the count during
847 * bootstrap (see early_kmem_cache_node_alloc).
849 if (!NUMA_BUILD
|| n
) {
850 atomic_long_inc(&n
->nr_slabs
);
851 atomic_long_add(objects
, &n
->total_objects
);
854 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
856 struct kmem_cache_node
*n
= get_node(s
, node
);
858 atomic_long_dec(&n
->nr_slabs
);
859 atomic_long_sub(objects
, &n
->total_objects
);
862 /* Object debug checks for alloc/free paths */
863 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
866 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
869 init_object(s
, object
, 0);
870 init_tracking(s
, object
);
873 static int alloc_debug_processing(struct kmem_cache
*s
, struct page
*page
,
874 void *object
, unsigned long addr
)
876 if (!check_slab(s
, page
))
879 if (!on_freelist(s
, page
, object
)) {
880 object_err(s
, page
, object
, "Object already allocated");
884 if (!check_valid_pointer(s
, page
, object
)) {
885 object_err(s
, page
, object
, "Freelist Pointer check fails");
889 if (!check_object(s
, page
, object
, 0))
892 /* Success perform special debug activities for allocs */
893 if (s
->flags
& SLAB_STORE_USER
)
894 set_track(s
, object
, TRACK_ALLOC
, addr
);
895 trace(s
, page
, object
, 1);
896 init_object(s
, object
, 1);
900 if (PageSlab(page
)) {
902 * If this is a slab page then lets do the best we can
903 * to avoid issues in the future. Marking all objects
904 * as used avoids touching the remaining objects.
906 slab_fix(s
, "Marking all objects used");
907 page
->inuse
= page
->objects
;
908 page
->freelist
= NULL
;
913 static int free_debug_processing(struct kmem_cache
*s
, struct page
*page
,
914 void *object
, unsigned long addr
)
916 if (!check_slab(s
, page
))
919 if (!check_valid_pointer(s
, page
, object
)) {
920 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
924 if (on_freelist(s
, page
, object
)) {
925 object_err(s
, page
, object
, "Object already free");
929 if (!check_object(s
, page
, object
, 1))
932 if (unlikely(s
!= page
->slab
)) {
933 if (!PageSlab(page
)) {
934 slab_err(s
, page
, "Attempt to free object(0x%p) "
935 "outside of slab", object
);
936 } else if (!page
->slab
) {
938 "SLUB <none>: no slab for object 0x%p.\n",
942 object_err(s
, page
, object
,
943 "page slab pointer corrupt.");
947 /* Special debug activities for freeing objects */
948 if (!PageSlubFrozen(page
) && !page
->freelist
)
949 remove_full(s
, page
);
950 if (s
->flags
& SLAB_STORE_USER
)
951 set_track(s
, object
, TRACK_FREE
, addr
);
952 trace(s
, page
, object
, 0);
953 init_object(s
, object
, 0);
957 slab_fix(s
, "Object at 0x%p not freed", object
);
961 static int __init
setup_slub_debug(char *str
)
963 slub_debug
= DEBUG_DEFAULT_FLAGS
;
964 if (*str
++ != '=' || !*str
)
966 * No options specified. Switch on full debugging.
972 * No options but restriction on slabs. This means full
973 * debugging for slabs matching a pattern.
980 * Switch off all debugging measures.
985 * Determine which debug features should be switched on
987 for (; *str
&& *str
!= ','; str
++) {
988 switch (tolower(*str
)) {
990 slub_debug
|= SLAB_DEBUG_FREE
;
993 slub_debug
|= SLAB_RED_ZONE
;
996 slub_debug
|= SLAB_POISON
;
999 slub_debug
|= SLAB_STORE_USER
;
1002 slub_debug
|= SLAB_TRACE
;
1005 printk(KERN_ERR
"slub_debug option '%c' "
1006 "unknown. skipped\n", *str
);
1012 slub_debug_slabs
= str
+ 1;
1017 __setup("slub_debug", setup_slub_debug
);
1019 static unsigned long kmem_cache_flags(unsigned long objsize
,
1020 unsigned long flags
, const char *name
,
1021 void (*ctor
)(void *))
1024 * Enable debugging if selected on the kernel commandline.
1026 if (slub_debug
&& (!slub_debug_slabs
||
1027 strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
)) == 0))
1028 flags
|= slub_debug
;
1033 static inline void setup_object_debug(struct kmem_cache
*s
,
1034 struct page
*page
, void *object
) {}
1036 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1037 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1039 static inline int free_debug_processing(struct kmem_cache
*s
,
1040 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1042 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1044 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1045 void *object
, int active
) { return 1; }
1046 static inline void add_full(struct kmem_cache_node
*n
, struct page
*page
) {}
1047 static inline unsigned long kmem_cache_flags(unsigned long objsize
,
1048 unsigned long flags
, const char *name
,
1049 void (*ctor
)(void *))
1053 #define slub_debug 0
1055 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1057 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1059 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1064 * Slab allocation and freeing
1066 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1067 struct kmem_cache_order_objects oo
)
1069 int order
= oo_order(oo
);
1072 return alloc_pages(flags
, order
);
1074 return alloc_pages_node(node
, flags
, order
);
1077 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1080 struct kmem_cache_order_objects oo
= s
->oo
;
1082 flags
|= s
->allocflags
;
1084 page
= alloc_slab_page(flags
| __GFP_NOWARN
| __GFP_NORETRY
, node
,
1086 if (unlikely(!page
)) {
1089 * Allocation may have failed due to fragmentation.
1090 * Try a lower order alloc if possible
1092 page
= alloc_slab_page(flags
, node
, oo
);
1096 stat(get_cpu_slab(s
, raw_smp_processor_id()), ORDER_FALLBACK
);
1098 page
->objects
= oo_objects(oo
);
1099 mod_zone_page_state(page_zone(page
),
1100 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1101 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1107 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1110 setup_object_debug(s
, page
, object
);
1111 if (unlikely(s
->ctor
))
1115 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1122 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1124 page
= allocate_slab(s
,
1125 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1129 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1131 page
->flags
|= 1 << PG_slab
;
1132 if (s
->flags
& (SLAB_DEBUG_FREE
| SLAB_RED_ZONE
| SLAB_POISON
|
1133 SLAB_STORE_USER
| SLAB_TRACE
))
1134 __SetPageSlubDebug(page
);
1136 start
= page_address(page
);
1138 if (unlikely(s
->flags
& SLAB_POISON
))
1139 memset(start
, POISON_INUSE
, PAGE_SIZE
<< compound_order(page
));
1142 for_each_object(p
, s
, start
, page
->objects
) {
1143 setup_object(s
, page
, last
);
1144 set_freepointer(s
, last
, p
);
1147 setup_object(s
, page
, last
);
1148 set_freepointer(s
, last
, NULL
);
1150 page
->freelist
= start
;
1156 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1158 int order
= compound_order(page
);
1159 int pages
= 1 << order
;
1161 if (unlikely(SLABDEBUG
&& PageSlubDebug(page
))) {
1164 slab_pad_check(s
, page
);
1165 for_each_object(p
, s
, page_address(page
),
1167 check_object(s
, page
, p
, 0);
1168 __ClearPageSlubDebug(page
);
1171 mod_zone_page_state(page_zone(page
),
1172 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1173 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1176 __ClearPageSlab(page
);
1177 reset_page_mapcount(page
);
1178 __free_pages(page
, order
);
1181 static void rcu_free_slab(struct rcu_head
*h
)
1185 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1186 __free_slab(page
->slab
, page
);
1189 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1191 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1193 * RCU free overloads the RCU head over the LRU
1195 struct rcu_head
*head
= (void *)&page
->lru
;
1197 call_rcu(head
, rcu_free_slab
);
1199 __free_slab(s
, page
);
1202 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1204 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1209 * Per slab locking using the pagelock
1211 static __always_inline
void slab_lock(struct page
*page
)
1213 bit_spin_lock(PG_locked
, &page
->flags
);
1216 static __always_inline
void slab_unlock(struct page
*page
)
1218 __bit_spin_unlock(PG_locked
, &page
->flags
);
1221 static __always_inline
int slab_trylock(struct page
*page
)
1225 rc
= bit_spin_trylock(PG_locked
, &page
->flags
);
1230 * Management of partially allocated slabs
1232 static void add_partial(struct kmem_cache_node
*n
,
1233 struct page
*page
, int tail
)
1235 spin_lock(&n
->list_lock
);
1238 list_add_tail(&page
->lru
, &n
->partial
);
1240 list_add(&page
->lru
, &n
->partial
);
1241 spin_unlock(&n
->list_lock
);
1244 static void remove_partial(struct kmem_cache
*s
, struct page
*page
)
1246 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1248 spin_lock(&n
->list_lock
);
1249 list_del(&page
->lru
);
1251 spin_unlock(&n
->list_lock
);
1255 * Lock slab and remove from the partial list.
1257 * Must hold list_lock.
1259 static inline int lock_and_freeze_slab(struct kmem_cache_node
*n
,
1262 if (slab_trylock(page
)) {
1263 list_del(&page
->lru
);
1265 __SetPageSlubFrozen(page
);
1272 * Try to allocate a partial slab from a specific node.
1274 static struct page
*get_partial_node(struct kmem_cache_node
*n
)
1279 * Racy check. If we mistakenly see no partial slabs then we
1280 * just allocate an empty slab. If we mistakenly try to get a
1281 * partial slab and there is none available then get_partials()
1284 if (!n
|| !n
->nr_partial
)
1287 spin_lock(&n
->list_lock
);
1288 list_for_each_entry(page
, &n
->partial
, lru
)
1289 if (lock_and_freeze_slab(n
, page
))
1293 spin_unlock(&n
->list_lock
);
1298 * Get a page from somewhere. Search in increasing NUMA distances.
1300 static struct page
*get_any_partial(struct kmem_cache
*s
, gfp_t flags
)
1303 struct zonelist
*zonelist
;
1306 enum zone_type high_zoneidx
= gfp_zone(flags
);
1310 * The defrag ratio allows a configuration of the tradeoffs between
1311 * inter node defragmentation and node local allocations. A lower
1312 * defrag_ratio increases the tendency to do local allocations
1313 * instead of attempting to obtain partial slabs from other nodes.
1315 * If the defrag_ratio is set to 0 then kmalloc() always
1316 * returns node local objects. If the ratio is higher then kmalloc()
1317 * may return off node objects because partial slabs are obtained
1318 * from other nodes and filled up.
1320 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1321 * defrag_ratio = 1000) then every (well almost) allocation will
1322 * first attempt to defrag slab caches on other nodes. This means
1323 * scanning over all nodes to look for partial slabs which may be
1324 * expensive if we do it every time we are trying to find a slab
1325 * with available objects.
1327 if (!s
->remote_node_defrag_ratio
||
1328 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1331 zonelist
= node_zonelist(slab_node(current
->mempolicy
), flags
);
1332 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
1333 struct kmem_cache_node
*n
;
1335 n
= get_node(s
, zone_to_nid(zone
));
1337 if (n
&& cpuset_zone_allowed_hardwall(zone
, flags
) &&
1338 n
->nr_partial
> s
->min_partial
) {
1339 page
= get_partial_node(n
);
1349 * Get a partial page, lock it and return it.
1351 static struct page
*get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
)
1354 int searchnode
= (node
== -1) ? numa_node_id() : node
;
1356 page
= get_partial_node(get_node(s
, searchnode
));
1357 if (page
|| (flags
& __GFP_THISNODE
))
1360 return get_any_partial(s
, flags
);
1364 * Move a page back to the lists.
1366 * Must be called with the slab lock held.
1368 * On exit the slab lock will have been dropped.
1370 static void unfreeze_slab(struct kmem_cache
*s
, struct page
*page
, int tail
)
1372 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1373 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, smp_processor_id());
1375 __ClearPageSlubFrozen(page
);
1378 if (page
->freelist
) {
1379 add_partial(n
, page
, tail
);
1380 stat(c
, tail
? DEACTIVATE_TO_TAIL
: DEACTIVATE_TO_HEAD
);
1382 stat(c
, DEACTIVATE_FULL
);
1383 if (SLABDEBUG
&& PageSlubDebug(page
) &&
1384 (s
->flags
& SLAB_STORE_USER
))
1389 stat(c
, DEACTIVATE_EMPTY
);
1390 if (n
->nr_partial
< s
->min_partial
) {
1392 * Adding an empty slab to the partial slabs in order
1393 * to avoid page allocator overhead. This slab needs
1394 * to come after the other slabs with objects in
1395 * so that the others get filled first. That way the
1396 * size of the partial list stays small.
1398 * kmem_cache_shrink can reclaim any empty slabs from
1401 add_partial(n
, page
, 1);
1405 stat(get_cpu_slab(s
, raw_smp_processor_id()), FREE_SLAB
);
1406 discard_slab(s
, page
);
1412 * Remove the cpu slab
1414 static void deactivate_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1416 struct page
*page
= c
->page
;
1420 stat(c
, DEACTIVATE_REMOTE_FREES
);
1422 * Merge cpu freelist into slab freelist. Typically we get here
1423 * because both freelists are empty. So this is unlikely
1426 while (unlikely(c
->freelist
)) {
1429 tail
= 0; /* Hot objects. Put the slab first */
1431 /* Retrieve object from cpu_freelist */
1432 object
= c
->freelist
;
1433 c
->freelist
= c
->freelist
[c
->offset
];
1435 /* And put onto the regular freelist */
1436 object
[c
->offset
] = page
->freelist
;
1437 page
->freelist
= object
;
1441 unfreeze_slab(s
, page
, tail
);
1444 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1446 stat(c
, CPUSLAB_FLUSH
);
1448 deactivate_slab(s
, c
);
1454 * Called from IPI handler with interrupts disabled.
1456 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
1458 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
1460 if (likely(c
&& c
->page
))
1464 static void flush_cpu_slab(void *d
)
1466 struct kmem_cache
*s
= d
;
1468 __flush_cpu_slab(s
, smp_processor_id());
1471 static void flush_all(struct kmem_cache
*s
)
1473 on_each_cpu(flush_cpu_slab
, s
, 1);
1477 * Check if the objects in a per cpu structure fit numa
1478 * locality expectations.
1480 static inline int node_match(struct kmem_cache_cpu
*c
, int node
)
1483 if (node
!= -1 && c
->node
!= node
)
1490 * Slow path. The lockless freelist is empty or we need to perform
1493 * Interrupts are disabled.
1495 * Processing is still very fast if new objects have been freed to the
1496 * regular freelist. In that case we simply take over the regular freelist
1497 * as the lockless freelist and zap the regular freelist.
1499 * If that is not working then we fall back to the partial lists. We take the
1500 * first element of the freelist as the object to allocate now and move the
1501 * rest of the freelist to the lockless freelist.
1503 * And if we were unable to get a new slab from the partial slab lists then
1504 * we need to allocate a new slab. This is the slowest path since it involves
1505 * a call to the page allocator and the setup of a new slab.
1507 static void *__slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, int node
,
1508 unsigned long addr
, struct kmem_cache_cpu
*c
)
1513 /* We handle __GFP_ZERO in the caller */
1514 gfpflags
&= ~__GFP_ZERO
;
1520 if (unlikely(!node_match(c
, node
)))
1523 stat(c
, ALLOC_REFILL
);
1526 object
= c
->page
->freelist
;
1527 if (unlikely(!object
))
1529 if (unlikely(SLABDEBUG
&& PageSlubDebug(c
->page
)))
1532 c
->freelist
= object
[c
->offset
];
1533 c
->page
->inuse
= c
->page
->objects
;
1534 c
->page
->freelist
= NULL
;
1535 c
->node
= page_to_nid(c
->page
);
1537 slab_unlock(c
->page
);
1538 stat(c
, ALLOC_SLOWPATH
);
1542 deactivate_slab(s
, c
);
1545 new = get_partial(s
, gfpflags
, node
);
1548 stat(c
, ALLOC_FROM_PARTIAL
);
1552 if (gfpflags
& __GFP_WAIT
)
1555 new = new_slab(s
, gfpflags
, node
);
1557 if (gfpflags
& __GFP_WAIT
)
1558 local_irq_disable();
1561 c
= get_cpu_slab(s
, smp_processor_id());
1562 stat(c
, ALLOC_SLAB
);
1566 __SetPageSlubFrozen(new);
1572 if (!alloc_debug_processing(s
, c
->page
, object
, addr
))
1576 c
->page
->freelist
= object
[c
->offset
];
1582 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1583 * have the fastpath folded into their functions. So no function call
1584 * overhead for requests that can be satisfied on the fastpath.
1586 * The fastpath works by first checking if the lockless freelist can be used.
1587 * If not then __slab_alloc is called for slow processing.
1589 * Otherwise we can simply pick the next object from the lockless free list.
1591 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
1592 gfp_t gfpflags
, int node
, unsigned long addr
)
1595 struct kmem_cache_cpu
*c
;
1596 unsigned long flags
;
1597 unsigned int objsize
;
1599 might_sleep_if(gfpflags
& __GFP_WAIT
);
1601 if (should_failslab(s
->objsize
, gfpflags
))
1604 local_irq_save(flags
);
1605 c
= get_cpu_slab(s
, smp_processor_id());
1606 objsize
= c
->objsize
;
1607 if (unlikely(!c
->freelist
|| !node_match(c
, node
)))
1609 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
1612 object
= c
->freelist
;
1613 c
->freelist
= object
[c
->offset
];
1614 stat(c
, ALLOC_FASTPATH
);
1616 local_irq_restore(flags
);
1618 if (unlikely((gfpflags
& __GFP_ZERO
) && object
))
1619 memset(object
, 0, objsize
);
1624 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
1626 return slab_alloc(s
, gfpflags
, -1, _RET_IP_
);
1628 EXPORT_SYMBOL(kmem_cache_alloc
);
1631 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
1633 return slab_alloc(s
, gfpflags
, node
, _RET_IP_
);
1635 EXPORT_SYMBOL(kmem_cache_alloc_node
);
1639 * Slow patch handling. This may still be called frequently since objects
1640 * have a longer lifetime than the cpu slabs in most processing loads.
1642 * So we still attempt to reduce cache line usage. Just take the slab
1643 * lock and free the item. If there is no additional partial page
1644 * handling required then we can return immediately.
1646 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
1647 void *x
, unsigned long addr
, unsigned int offset
)
1650 void **object
= (void *)x
;
1651 struct kmem_cache_cpu
*c
;
1653 c
= get_cpu_slab(s
, raw_smp_processor_id());
1654 stat(c
, FREE_SLOWPATH
);
1657 if (unlikely(SLABDEBUG
&& PageSlubDebug(page
)))
1661 prior
= object
[offset
] = page
->freelist
;
1662 page
->freelist
= object
;
1665 if (unlikely(PageSlubFrozen(page
))) {
1666 stat(c
, FREE_FROZEN
);
1670 if (unlikely(!page
->inuse
))
1674 * Objects left in the slab. If it was not on the partial list before
1677 if (unlikely(!prior
)) {
1678 add_partial(get_node(s
, page_to_nid(page
)), page
, 1);
1679 stat(c
, FREE_ADD_PARTIAL
);
1689 * Slab still on the partial list.
1691 remove_partial(s
, page
);
1692 stat(c
, FREE_REMOVE_PARTIAL
);
1696 discard_slab(s
, page
);
1700 if (!free_debug_processing(s
, page
, x
, addr
))
1706 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
1707 * can perform fastpath freeing without additional function calls.
1709 * The fastpath is only possible if we are freeing to the current cpu slab
1710 * of this processor. This typically the case if we have just allocated
1713 * If fastpath is not possible then fall back to __slab_free where we deal
1714 * with all sorts of special processing.
1716 static __always_inline
void slab_free(struct kmem_cache
*s
,
1717 struct page
*page
, void *x
, unsigned long addr
)
1719 void **object
= (void *)x
;
1720 struct kmem_cache_cpu
*c
;
1721 unsigned long flags
;
1723 local_irq_save(flags
);
1724 c
= get_cpu_slab(s
, smp_processor_id());
1725 debug_check_no_locks_freed(object
, c
->objsize
);
1726 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
1727 debug_check_no_obj_freed(object
, s
->objsize
);
1728 if (likely(page
== c
->page
&& c
->node
>= 0)) {
1729 object
[c
->offset
] = c
->freelist
;
1730 c
->freelist
= object
;
1731 stat(c
, FREE_FASTPATH
);
1733 __slab_free(s
, page
, x
, addr
, c
->offset
);
1735 local_irq_restore(flags
);
1738 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
1742 page
= virt_to_head_page(x
);
1744 slab_free(s
, page
, x
, _RET_IP_
);
1746 EXPORT_SYMBOL(kmem_cache_free
);
1748 /* Figure out on which slab page the object resides */
1749 static struct page
*get_object_page(const void *x
)
1751 struct page
*page
= virt_to_head_page(x
);
1753 if (!PageSlab(page
))
1760 * Object placement in a slab is made very easy because we always start at
1761 * offset 0. If we tune the size of the object to the alignment then we can
1762 * get the required alignment by putting one properly sized object after
1765 * Notice that the allocation order determines the sizes of the per cpu
1766 * caches. Each processor has always one slab available for allocations.
1767 * Increasing the allocation order reduces the number of times that slabs
1768 * must be moved on and off the partial lists and is therefore a factor in
1773 * Mininum / Maximum order of slab pages. This influences locking overhead
1774 * and slab fragmentation. A higher order reduces the number of partial slabs
1775 * and increases the number of allocations possible without having to
1776 * take the list_lock.
1778 static int slub_min_order
;
1779 static int slub_max_order
= PAGE_ALLOC_COSTLY_ORDER
;
1780 static int slub_min_objects
;
1783 * Merge control. If this is set then no merging of slab caches will occur.
1784 * (Could be removed. This was introduced to pacify the merge skeptics.)
1786 static int slub_nomerge
;
1789 * Calculate the order of allocation given an slab object size.
1791 * The order of allocation has significant impact on performance and other
1792 * system components. Generally order 0 allocations should be preferred since
1793 * order 0 does not cause fragmentation in the page allocator. Larger objects
1794 * be problematic to put into order 0 slabs because there may be too much
1795 * unused space left. We go to a higher order if more than 1/16th of the slab
1798 * In order to reach satisfactory performance we must ensure that a minimum
1799 * number of objects is in one slab. Otherwise we may generate too much
1800 * activity on the partial lists which requires taking the list_lock. This is
1801 * less a concern for large slabs though which are rarely used.
1803 * slub_max_order specifies the order where we begin to stop considering the
1804 * number of objects in a slab as critical. If we reach slub_max_order then
1805 * we try to keep the page order as low as possible. So we accept more waste
1806 * of space in favor of a small page order.
1808 * Higher order allocations also allow the placement of more objects in a
1809 * slab and thereby reduce object handling overhead. If the user has
1810 * requested a higher mininum order then we start with that one instead of
1811 * the smallest order which will fit the object.
1813 static inline int slab_order(int size
, int min_objects
,
1814 int max_order
, int fract_leftover
)
1818 int min_order
= slub_min_order
;
1820 if ((PAGE_SIZE
<< min_order
) / size
> MAX_OBJS_PER_PAGE
)
1821 return get_order(size
* MAX_OBJS_PER_PAGE
) - 1;
1823 for (order
= max(min_order
,
1824 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
1825 order
<= max_order
; order
++) {
1827 unsigned long slab_size
= PAGE_SIZE
<< order
;
1829 if (slab_size
< min_objects
* size
)
1832 rem
= slab_size
% size
;
1834 if (rem
<= slab_size
/ fract_leftover
)
1842 static inline int calculate_order(int size
)
1849 * Attempt to find best configuration for a slab. This
1850 * works by first attempting to generate a layout with
1851 * the best configuration and backing off gradually.
1853 * First we reduce the acceptable waste in a slab. Then
1854 * we reduce the minimum objects required in a slab.
1856 min_objects
= slub_min_objects
;
1858 min_objects
= 4 * (fls(nr_cpu_ids
) + 1);
1859 while (min_objects
> 1) {
1861 while (fraction
>= 4) {
1862 order
= slab_order(size
, min_objects
,
1863 slub_max_order
, fraction
);
1864 if (order
<= slub_max_order
)
1872 * We were unable to place multiple objects in a slab. Now
1873 * lets see if we can place a single object there.
1875 order
= slab_order(size
, 1, slub_max_order
, 1);
1876 if (order
<= slub_max_order
)
1880 * Doh this slab cannot be placed using slub_max_order.
1882 order
= slab_order(size
, 1, MAX_ORDER
, 1);
1883 if (order
<= MAX_ORDER
)
1889 * Figure out what the alignment of the objects will be.
1891 static unsigned long calculate_alignment(unsigned long flags
,
1892 unsigned long align
, unsigned long size
)
1895 * If the user wants hardware cache aligned objects then follow that
1896 * suggestion if the object is sufficiently large.
1898 * The hardware cache alignment cannot override the specified
1899 * alignment though. If that is greater then use it.
1901 if (flags
& SLAB_HWCACHE_ALIGN
) {
1902 unsigned long ralign
= cache_line_size();
1903 while (size
<= ralign
/ 2)
1905 align
= max(align
, ralign
);
1908 if (align
< ARCH_SLAB_MINALIGN
)
1909 align
= ARCH_SLAB_MINALIGN
;
1911 return ALIGN(align
, sizeof(void *));
1914 static void init_kmem_cache_cpu(struct kmem_cache
*s
,
1915 struct kmem_cache_cpu
*c
)
1920 c
->offset
= s
->offset
/ sizeof(void *);
1921 c
->objsize
= s
->objsize
;
1922 #ifdef CONFIG_SLUB_STATS
1923 memset(c
->stat
, 0, NR_SLUB_STAT_ITEMS
* sizeof(unsigned));
1928 init_kmem_cache_node(struct kmem_cache_node
*n
, struct kmem_cache
*s
)
1931 spin_lock_init(&n
->list_lock
);
1932 INIT_LIST_HEAD(&n
->partial
);
1933 #ifdef CONFIG_SLUB_DEBUG
1934 atomic_long_set(&n
->nr_slabs
, 0);
1935 atomic_long_set(&n
->total_objects
, 0);
1936 INIT_LIST_HEAD(&n
->full
);
1942 * Per cpu array for per cpu structures.
1944 * The per cpu array places all kmem_cache_cpu structures from one processor
1945 * close together meaning that it becomes possible that multiple per cpu
1946 * structures are contained in one cacheline. This may be particularly
1947 * beneficial for the kmalloc caches.
1949 * A desktop system typically has around 60-80 slabs. With 100 here we are
1950 * likely able to get per cpu structures for all caches from the array defined
1951 * here. We must be able to cover all kmalloc caches during bootstrap.
1953 * If the per cpu array is exhausted then fall back to kmalloc
1954 * of individual cachelines. No sharing is possible then.
1956 #define NR_KMEM_CACHE_CPU 100
1958 static DEFINE_PER_CPU(struct kmem_cache_cpu
,
1959 kmem_cache_cpu
)[NR_KMEM_CACHE_CPU
];
1961 static DEFINE_PER_CPU(struct kmem_cache_cpu
*, kmem_cache_cpu_free
);
1962 static DECLARE_BITMAP(kmem_cach_cpu_free_init_once
, CONFIG_NR_CPUS
);
1964 static struct kmem_cache_cpu
*alloc_kmem_cache_cpu(struct kmem_cache
*s
,
1965 int cpu
, gfp_t flags
)
1967 struct kmem_cache_cpu
*c
= per_cpu(kmem_cache_cpu_free
, cpu
);
1970 per_cpu(kmem_cache_cpu_free
, cpu
) =
1971 (void *)c
->freelist
;
1973 /* Table overflow: So allocate ourselves */
1975 ALIGN(sizeof(struct kmem_cache_cpu
), cache_line_size()),
1976 flags
, cpu_to_node(cpu
));
1981 init_kmem_cache_cpu(s
, c
);
1985 static void free_kmem_cache_cpu(struct kmem_cache_cpu
*c
, int cpu
)
1987 if (c
< per_cpu(kmem_cache_cpu
, cpu
) ||
1988 c
>= per_cpu(kmem_cache_cpu
, cpu
) + NR_KMEM_CACHE_CPU
) {
1992 c
->freelist
= (void *)per_cpu(kmem_cache_cpu_free
, cpu
);
1993 per_cpu(kmem_cache_cpu_free
, cpu
) = c
;
1996 static void free_kmem_cache_cpus(struct kmem_cache
*s
)
2000 for_each_online_cpu(cpu
) {
2001 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
2004 s
->cpu_slab
[cpu
] = NULL
;
2005 free_kmem_cache_cpu(c
, cpu
);
2010 static int alloc_kmem_cache_cpus(struct kmem_cache
*s
, gfp_t flags
)
2014 for_each_online_cpu(cpu
) {
2015 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
2020 c
= alloc_kmem_cache_cpu(s
, cpu
, flags
);
2022 free_kmem_cache_cpus(s
);
2025 s
->cpu_slab
[cpu
] = c
;
2031 * Initialize the per cpu array.
2033 static void init_alloc_cpu_cpu(int cpu
)
2037 if (cpumask_test_cpu(cpu
, to_cpumask(kmem_cach_cpu_free_init_once
)))
2040 for (i
= NR_KMEM_CACHE_CPU
- 1; i
>= 0; i
--)
2041 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu
, cpu
)[i
], cpu
);
2043 cpumask_set_cpu(cpu
, to_cpumask(kmem_cach_cpu_free_init_once
));
2046 static void __init
init_alloc_cpu(void)
2050 for_each_online_cpu(cpu
)
2051 init_alloc_cpu_cpu(cpu
);
2055 static inline void free_kmem_cache_cpus(struct kmem_cache
*s
) {}
2056 static inline void init_alloc_cpu(void) {}
2058 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
, gfp_t flags
)
2060 init_kmem_cache_cpu(s
, &s
->cpu_slab
);
2067 * No kmalloc_node yet so do it by hand. We know that this is the first
2068 * slab on the node for this slabcache. There are no concurrent accesses
2071 * Note that this function only works on the kmalloc_node_cache
2072 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2073 * memory on a fresh node that has no slab structures yet.
2075 static void early_kmem_cache_node_alloc(gfp_t gfpflags
, int node
)
2078 struct kmem_cache_node
*n
;
2079 unsigned long flags
;
2081 BUG_ON(kmalloc_caches
->size
< sizeof(struct kmem_cache_node
));
2083 page
= new_slab(kmalloc_caches
, gfpflags
, node
);
2086 if (page_to_nid(page
) != node
) {
2087 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2089 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2090 "in order to be able to continue\n");
2095 page
->freelist
= get_freepointer(kmalloc_caches
, n
);
2097 kmalloc_caches
->node
[node
] = n
;
2098 #ifdef CONFIG_SLUB_DEBUG
2099 init_object(kmalloc_caches
, n
, 1);
2100 init_tracking(kmalloc_caches
, n
);
2102 init_kmem_cache_node(n
, kmalloc_caches
);
2103 inc_slabs_node(kmalloc_caches
, node
, page
->objects
);
2106 * lockdep requires consistent irq usage for each lock
2107 * so even though there cannot be a race this early in
2108 * the boot sequence, we still disable irqs.
2110 local_irq_save(flags
);
2111 add_partial(n
, page
, 0);
2112 local_irq_restore(flags
);
2115 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2119 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2120 struct kmem_cache_node
*n
= s
->node
[node
];
2121 if (n
&& n
!= &s
->local_node
)
2122 kmem_cache_free(kmalloc_caches
, n
);
2123 s
->node
[node
] = NULL
;
2127 static int init_kmem_cache_nodes(struct kmem_cache
*s
, gfp_t gfpflags
)
2132 if (slab_state
>= UP
)
2133 local_node
= page_to_nid(virt_to_page(s
));
2137 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2138 struct kmem_cache_node
*n
;
2140 if (local_node
== node
)
2143 if (slab_state
== DOWN
) {
2144 early_kmem_cache_node_alloc(gfpflags
, node
);
2147 n
= kmem_cache_alloc_node(kmalloc_caches
,
2151 free_kmem_cache_nodes(s
);
2157 init_kmem_cache_node(n
, s
);
2162 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2166 static int init_kmem_cache_nodes(struct kmem_cache
*s
, gfp_t gfpflags
)
2168 init_kmem_cache_node(&s
->local_node
, s
);
2173 static void set_min_partial(struct kmem_cache
*s
, unsigned long min
)
2175 if (min
< MIN_PARTIAL
)
2177 else if (min
> MAX_PARTIAL
)
2179 s
->min_partial
= min
;
2183 * calculate_sizes() determines the order and the distribution of data within
2186 static int calculate_sizes(struct kmem_cache
*s
, int forced_order
)
2188 unsigned long flags
= s
->flags
;
2189 unsigned long size
= s
->objsize
;
2190 unsigned long align
= s
->align
;
2194 * Round up object size to the next word boundary. We can only
2195 * place the free pointer at word boundaries and this determines
2196 * the possible location of the free pointer.
2198 size
= ALIGN(size
, sizeof(void *));
2200 #ifdef CONFIG_SLUB_DEBUG
2202 * Determine if we can poison the object itself. If the user of
2203 * the slab may touch the object after free or before allocation
2204 * then we should never poison the object itself.
2206 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2208 s
->flags
|= __OBJECT_POISON
;
2210 s
->flags
&= ~__OBJECT_POISON
;
2214 * If we are Redzoning then check if there is some space between the
2215 * end of the object and the free pointer. If not then add an
2216 * additional word to have some bytes to store Redzone information.
2218 if ((flags
& SLAB_RED_ZONE
) && size
== s
->objsize
)
2219 size
+= sizeof(void *);
2223 * With that we have determined the number of bytes in actual use
2224 * by the object. This is the potential offset to the free pointer.
2228 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
2231 * Relocate free pointer after the object if it is not
2232 * permitted to overwrite the first word of the object on
2235 * This is the case if we do RCU, have a constructor or
2236 * destructor or are poisoning the objects.
2239 size
+= sizeof(void *);
2242 #ifdef CONFIG_SLUB_DEBUG
2243 if (flags
& SLAB_STORE_USER
)
2245 * Need to store information about allocs and frees after
2248 size
+= 2 * sizeof(struct track
);
2250 if (flags
& SLAB_RED_ZONE
)
2252 * Add some empty padding so that we can catch
2253 * overwrites from earlier objects rather than let
2254 * tracking information or the free pointer be
2255 * corrupted if a user writes before the start
2258 size
+= sizeof(void *);
2262 * Determine the alignment based on various parameters that the
2263 * user specified and the dynamic determination of cache line size
2266 align
= calculate_alignment(flags
, align
, s
->objsize
);
2269 * SLUB stores one object immediately after another beginning from
2270 * offset 0. In order to align the objects we have to simply size
2271 * each object to conform to the alignment.
2273 size
= ALIGN(size
, align
);
2275 if (forced_order
>= 0)
2276 order
= forced_order
;
2278 order
= calculate_order(size
);
2285 s
->allocflags
|= __GFP_COMP
;
2287 if (s
->flags
& SLAB_CACHE_DMA
)
2288 s
->allocflags
|= SLUB_DMA
;
2290 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
2291 s
->allocflags
|= __GFP_RECLAIMABLE
;
2294 * Determine the number of objects per slab
2296 s
->oo
= oo_make(order
, size
);
2297 s
->min
= oo_make(get_order(size
), size
);
2298 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
2301 return !!oo_objects(s
->oo
);
2305 static int kmem_cache_open(struct kmem_cache
*s
, gfp_t gfpflags
,
2306 const char *name
, size_t size
,
2307 size_t align
, unsigned long flags
,
2308 void (*ctor
)(void *))
2310 memset(s
, 0, kmem_size
);
2315 s
->flags
= kmem_cache_flags(size
, flags
, name
, ctor
);
2317 if (!calculate_sizes(s
, -1))
2321 * The larger the object size is, the more pages we want on the partial
2322 * list to avoid pounding the page allocator excessively.
2324 set_min_partial(s
, ilog2(s
->size
));
2327 s
->remote_node_defrag_ratio
= 1000;
2329 if (!init_kmem_cache_nodes(s
, gfpflags
& ~SLUB_DMA
))
2332 if (alloc_kmem_cache_cpus(s
, gfpflags
& ~SLUB_DMA
))
2334 free_kmem_cache_nodes(s
);
2336 if (flags
& SLAB_PANIC
)
2337 panic("Cannot create slab %s size=%lu realsize=%u "
2338 "order=%u offset=%u flags=%lx\n",
2339 s
->name
, (unsigned long)size
, s
->size
, oo_order(s
->oo
),
2345 * Check if a given pointer is valid
2347 int kmem_ptr_validate(struct kmem_cache
*s
, const void *object
)
2351 page
= get_object_page(object
);
2353 if (!page
|| s
!= page
->slab
)
2354 /* No slab or wrong slab */
2357 if (!check_valid_pointer(s
, page
, object
))
2361 * We could also check if the object is on the slabs freelist.
2362 * But this would be too expensive and it seems that the main
2363 * purpose of kmem_ptr_valid() is to check if the object belongs
2364 * to a certain slab.
2368 EXPORT_SYMBOL(kmem_ptr_validate
);
2371 * Determine the size of a slab object
2373 unsigned int kmem_cache_size(struct kmem_cache
*s
)
2377 EXPORT_SYMBOL(kmem_cache_size
);
2379 const char *kmem_cache_name(struct kmem_cache
*s
)
2383 EXPORT_SYMBOL(kmem_cache_name
);
2385 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
2388 #ifdef CONFIG_SLUB_DEBUG
2389 void *addr
= page_address(page
);
2391 DECLARE_BITMAP(map
, page
->objects
);
2393 bitmap_zero(map
, page
->objects
);
2394 slab_err(s
, page
, "%s", text
);
2396 for_each_free_object(p
, s
, page
->freelist
)
2397 set_bit(slab_index(p
, s
, addr
), map
);
2399 for_each_object(p
, s
, addr
, page
->objects
) {
2401 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
2402 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
2404 print_tracking(s
, p
);
2412 * Attempt to free all partial slabs on a node.
2414 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
2416 unsigned long flags
;
2417 struct page
*page
, *h
;
2419 spin_lock_irqsave(&n
->list_lock
, flags
);
2420 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
2422 list_del(&page
->lru
);
2423 discard_slab(s
, page
);
2426 list_slab_objects(s
, page
,
2427 "Objects remaining on kmem_cache_close()");
2430 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2434 * Release all resources used by a slab cache.
2436 static inline int kmem_cache_close(struct kmem_cache
*s
)
2442 /* Attempt to free all objects */
2443 free_kmem_cache_cpus(s
);
2444 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2445 struct kmem_cache_node
*n
= get_node(s
, node
);
2448 if (n
->nr_partial
|| slabs_node(s
, node
))
2451 free_kmem_cache_nodes(s
);
2456 * Close a cache and release the kmem_cache structure
2457 * (must be used for caches created using kmem_cache_create)
2459 void kmem_cache_destroy(struct kmem_cache
*s
)
2461 down_write(&slub_lock
);
2465 up_write(&slub_lock
);
2466 if (kmem_cache_close(s
)) {
2467 printk(KERN_ERR
"SLUB %s: %s called for cache that "
2468 "still has objects.\n", s
->name
, __func__
);
2471 sysfs_slab_remove(s
);
2473 up_write(&slub_lock
);
2475 EXPORT_SYMBOL(kmem_cache_destroy
);
2477 /********************************************************************
2479 *******************************************************************/
2481 struct kmem_cache kmalloc_caches
[PAGE_SHIFT
+ 1] __cacheline_aligned
;
2482 EXPORT_SYMBOL(kmalloc_caches
);
2484 static int __init
setup_slub_min_order(char *str
)
2486 get_option(&str
, &slub_min_order
);
2491 __setup("slub_min_order=", setup_slub_min_order
);
2493 static int __init
setup_slub_max_order(char *str
)
2495 get_option(&str
, &slub_max_order
);
2500 __setup("slub_max_order=", setup_slub_max_order
);
2502 static int __init
setup_slub_min_objects(char *str
)
2504 get_option(&str
, &slub_min_objects
);
2509 __setup("slub_min_objects=", setup_slub_min_objects
);
2511 static int __init
setup_slub_nomerge(char *str
)
2517 __setup("slub_nomerge", setup_slub_nomerge
);
2519 static struct kmem_cache
*create_kmalloc_cache(struct kmem_cache
*s
,
2520 const char *name
, int size
, gfp_t gfp_flags
)
2522 unsigned int flags
= 0;
2524 if (gfp_flags
& SLUB_DMA
)
2525 flags
= SLAB_CACHE_DMA
;
2527 down_write(&slub_lock
);
2528 if (!kmem_cache_open(s
, gfp_flags
, name
, size
, ARCH_KMALLOC_MINALIGN
,
2532 list_add(&s
->list
, &slab_caches
);
2533 up_write(&slub_lock
);
2534 if (sysfs_slab_add(s
))
2539 panic("Creation of kmalloc slab %s size=%d failed.\n", name
, size
);
2542 #ifdef CONFIG_ZONE_DMA
2543 static struct kmem_cache
*kmalloc_caches_dma
[PAGE_SHIFT
+ 1];
2545 static void sysfs_add_func(struct work_struct
*w
)
2547 struct kmem_cache
*s
;
2549 down_write(&slub_lock
);
2550 list_for_each_entry(s
, &slab_caches
, list
) {
2551 if (s
->flags
& __SYSFS_ADD_DEFERRED
) {
2552 s
->flags
&= ~__SYSFS_ADD_DEFERRED
;
2556 up_write(&slub_lock
);
2559 static DECLARE_WORK(sysfs_add_work
, sysfs_add_func
);
2561 static noinline
struct kmem_cache
*dma_kmalloc_cache(int index
, gfp_t flags
)
2563 struct kmem_cache
*s
;
2567 s
= kmalloc_caches_dma
[index
];
2571 /* Dynamically create dma cache */
2572 if (flags
& __GFP_WAIT
)
2573 down_write(&slub_lock
);
2575 if (!down_write_trylock(&slub_lock
))
2579 if (kmalloc_caches_dma
[index
])
2582 realsize
= kmalloc_caches
[index
].objsize
;
2583 text
= kasprintf(flags
& ~SLUB_DMA
, "kmalloc_dma-%d",
2584 (unsigned int)realsize
);
2585 s
= kmalloc(kmem_size
, flags
& ~SLUB_DMA
);
2587 if (!s
|| !text
|| !kmem_cache_open(s
, flags
, text
,
2588 realsize
, ARCH_KMALLOC_MINALIGN
,
2589 SLAB_CACHE_DMA
|__SYSFS_ADD_DEFERRED
, NULL
)) {
2595 list_add(&s
->list
, &slab_caches
);
2596 kmalloc_caches_dma
[index
] = s
;
2598 schedule_work(&sysfs_add_work
);
2601 up_write(&slub_lock
);
2603 return kmalloc_caches_dma
[index
];
2608 * Conversion table for small slabs sizes / 8 to the index in the
2609 * kmalloc array. This is necessary for slabs < 192 since we have non power
2610 * of two cache sizes there. The size of larger slabs can be determined using
2613 static s8 size_index
[24] = {
2640 static struct kmem_cache
*get_slab(size_t size
, gfp_t flags
)
2646 return ZERO_SIZE_PTR
;
2648 index
= size_index
[(size
- 1) / 8];
2650 index
= fls(size
- 1);
2652 #ifdef CONFIG_ZONE_DMA
2653 if (unlikely((flags
& SLUB_DMA
)))
2654 return dma_kmalloc_cache(index
, flags
);
2657 return &kmalloc_caches
[index
];
2660 void *__kmalloc(size_t size
, gfp_t flags
)
2662 struct kmem_cache
*s
;
2664 if (unlikely(size
> PAGE_SIZE
))
2665 return kmalloc_large(size
, flags
);
2667 s
= get_slab(size
, flags
);
2669 if (unlikely(ZERO_OR_NULL_PTR(s
)))
2672 return slab_alloc(s
, flags
, -1, _RET_IP_
);
2674 EXPORT_SYMBOL(__kmalloc
);
2676 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
2678 struct page
*page
= alloc_pages_node(node
, flags
| __GFP_COMP
,
2682 return page_address(page
);
2688 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
2690 struct kmem_cache
*s
;
2692 if (unlikely(size
> PAGE_SIZE
))
2693 return kmalloc_large_node(size
, flags
, node
);
2695 s
= get_slab(size
, flags
);
2697 if (unlikely(ZERO_OR_NULL_PTR(s
)))
2700 return slab_alloc(s
, flags
, node
, _RET_IP_
);
2702 EXPORT_SYMBOL(__kmalloc_node
);
2705 size_t ksize(const void *object
)
2708 struct kmem_cache
*s
;
2710 if (unlikely(object
== ZERO_SIZE_PTR
))
2713 page
= virt_to_head_page(object
);
2715 if (unlikely(!PageSlab(page
))) {
2716 WARN_ON(!PageCompound(page
));
2717 return PAGE_SIZE
<< compound_order(page
);
2721 #ifdef CONFIG_SLUB_DEBUG
2723 * Debugging requires use of the padding between object
2724 * and whatever may come after it.
2726 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
2731 * If we have the need to store the freelist pointer
2732 * back there or track user information then we can
2733 * only use the space before that information.
2735 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
2738 * Else we can use all the padding etc for the allocation
2743 void kfree(const void *x
)
2746 void *object
= (void *)x
;
2748 if (unlikely(ZERO_OR_NULL_PTR(x
)))
2751 page
= virt_to_head_page(x
);
2752 if (unlikely(!PageSlab(page
))) {
2753 BUG_ON(!PageCompound(page
));
2757 slab_free(page
->slab
, page
, object
, _RET_IP_
);
2759 EXPORT_SYMBOL(kfree
);
2762 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2763 * the remaining slabs by the number of items in use. The slabs with the
2764 * most items in use come first. New allocations will then fill those up
2765 * and thus they can be removed from the partial lists.
2767 * The slabs with the least items are placed last. This results in them
2768 * being allocated from last increasing the chance that the last objects
2769 * are freed in them.
2771 int kmem_cache_shrink(struct kmem_cache
*s
)
2775 struct kmem_cache_node
*n
;
2778 int objects
= oo_objects(s
->max
);
2779 struct list_head
*slabs_by_inuse
=
2780 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
2781 unsigned long flags
;
2783 if (!slabs_by_inuse
)
2787 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2788 n
= get_node(s
, node
);
2793 for (i
= 0; i
< objects
; i
++)
2794 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
2796 spin_lock_irqsave(&n
->list_lock
, flags
);
2799 * Build lists indexed by the items in use in each slab.
2801 * Note that concurrent frees may occur while we hold the
2802 * list_lock. page->inuse here is the upper limit.
2804 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
2805 if (!page
->inuse
&& slab_trylock(page
)) {
2807 * Must hold slab lock here because slab_free
2808 * may have freed the last object and be
2809 * waiting to release the slab.
2811 list_del(&page
->lru
);
2814 discard_slab(s
, page
);
2816 list_move(&page
->lru
,
2817 slabs_by_inuse
+ page
->inuse
);
2822 * Rebuild the partial list with the slabs filled up most
2823 * first and the least used slabs at the end.
2825 for (i
= objects
- 1; i
>= 0; i
--)
2826 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
2828 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2831 kfree(slabs_by_inuse
);
2834 EXPORT_SYMBOL(kmem_cache_shrink
);
2836 #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2837 static int slab_mem_going_offline_callback(void *arg
)
2839 struct kmem_cache
*s
;
2841 down_read(&slub_lock
);
2842 list_for_each_entry(s
, &slab_caches
, list
)
2843 kmem_cache_shrink(s
);
2844 up_read(&slub_lock
);
2849 static void slab_mem_offline_callback(void *arg
)
2851 struct kmem_cache_node
*n
;
2852 struct kmem_cache
*s
;
2853 struct memory_notify
*marg
= arg
;
2856 offline_node
= marg
->status_change_nid
;
2859 * If the node still has available memory. we need kmem_cache_node
2862 if (offline_node
< 0)
2865 down_read(&slub_lock
);
2866 list_for_each_entry(s
, &slab_caches
, list
) {
2867 n
= get_node(s
, offline_node
);
2870 * if n->nr_slabs > 0, slabs still exist on the node
2871 * that is going down. We were unable to free them,
2872 * and offline_pages() function shoudn't call this
2873 * callback. So, we must fail.
2875 BUG_ON(slabs_node(s
, offline_node
));
2877 s
->node
[offline_node
] = NULL
;
2878 kmem_cache_free(kmalloc_caches
, n
);
2881 up_read(&slub_lock
);
2884 static int slab_mem_going_online_callback(void *arg
)
2886 struct kmem_cache_node
*n
;
2887 struct kmem_cache
*s
;
2888 struct memory_notify
*marg
= arg
;
2889 int nid
= marg
->status_change_nid
;
2893 * If the node's memory is already available, then kmem_cache_node is
2894 * already created. Nothing to do.
2900 * We are bringing a node online. No memory is available yet. We must
2901 * allocate a kmem_cache_node structure in order to bring the node
2904 down_read(&slub_lock
);
2905 list_for_each_entry(s
, &slab_caches
, list
) {
2907 * XXX: kmem_cache_alloc_node will fallback to other nodes
2908 * since memory is not yet available from the node that
2911 n
= kmem_cache_alloc(kmalloc_caches
, GFP_KERNEL
);
2916 init_kmem_cache_node(n
, s
);
2920 up_read(&slub_lock
);
2924 static int slab_memory_callback(struct notifier_block
*self
,
2925 unsigned long action
, void *arg
)
2930 case MEM_GOING_ONLINE
:
2931 ret
= slab_mem_going_online_callback(arg
);
2933 case MEM_GOING_OFFLINE
:
2934 ret
= slab_mem_going_offline_callback(arg
);
2937 case MEM_CANCEL_ONLINE
:
2938 slab_mem_offline_callback(arg
);
2941 case MEM_CANCEL_OFFLINE
:
2945 ret
= notifier_from_errno(ret
);
2951 #endif /* CONFIG_MEMORY_HOTPLUG */
2953 /********************************************************************
2954 * Basic setup of slabs
2955 *******************************************************************/
2957 void __init
kmem_cache_init(void)
2966 * Must first have the slab cache available for the allocations of the
2967 * struct kmem_cache_node's. There is special bootstrap code in
2968 * kmem_cache_open for slab_state == DOWN.
2970 create_kmalloc_cache(&kmalloc_caches
[0], "kmem_cache_node",
2971 sizeof(struct kmem_cache_node
), GFP_KERNEL
);
2972 kmalloc_caches
[0].refcount
= -1;
2975 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
2978 /* Able to allocate the per node structures */
2979 slab_state
= PARTIAL
;
2981 /* Caches that are not of the two-to-the-power-of size */
2982 if (KMALLOC_MIN_SIZE
<= 64) {
2983 create_kmalloc_cache(&kmalloc_caches
[1],
2984 "kmalloc-96", 96, GFP_KERNEL
);
2986 create_kmalloc_cache(&kmalloc_caches
[2],
2987 "kmalloc-192", 192, GFP_KERNEL
);
2991 for (i
= KMALLOC_SHIFT_LOW
; i
<= PAGE_SHIFT
; i
++) {
2992 create_kmalloc_cache(&kmalloc_caches
[i
],
2993 "kmalloc", 1 << i
, GFP_KERNEL
);
2999 * Patch up the size_index table if we have strange large alignment
3000 * requirements for the kmalloc array. This is only the case for
3001 * MIPS it seems. The standard arches will not generate any code here.
3003 * Largest permitted alignment is 256 bytes due to the way we
3004 * handle the index determination for the smaller caches.
3006 * Make sure that nothing crazy happens if someone starts tinkering
3007 * around with ARCH_KMALLOC_MINALIGN
3009 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 256 ||
3010 (KMALLOC_MIN_SIZE
& (KMALLOC_MIN_SIZE
- 1)));
3012 for (i
= 8; i
< KMALLOC_MIN_SIZE
; i
+= 8)
3013 size_index
[(i
- 1) / 8] = KMALLOC_SHIFT_LOW
;
3015 if (KMALLOC_MIN_SIZE
== 128) {
3017 * The 192 byte sized cache is not used if the alignment
3018 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3021 for (i
= 128 + 8; i
<= 192; i
+= 8)
3022 size_index
[(i
- 1) / 8] = 8;
3027 /* Provide the correct kmalloc names now that the caches are up */
3028 for (i
= KMALLOC_SHIFT_LOW
; i
<= PAGE_SHIFT
; i
++)
3029 kmalloc_caches
[i
]. name
=
3030 kasprintf(GFP_KERNEL
, "kmalloc-%d", 1 << i
);
3033 register_cpu_notifier(&slab_notifier
);
3034 kmem_size
= offsetof(struct kmem_cache
, cpu_slab
) +
3035 nr_cpu_ids
* sizeof(struct kmem_cache_cpu
*);
3037 kmem_size
= sizeof(struct kmem_cache
);
3041 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3042 " CPUs=%d, Nodes=%d\n",
3043 caches
, cache_line_size(),
3044 slub_min_order
, slub_max_order
, slub_min_objects
,
3045 nr_cpu_ids
, nr_node_ids
);
3049 * Find a mergeable slab cache
3051 static int slab_unmergeable(struct kmem_cache
*s
)
3053 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3060 * We may have set a slab to be unmergeable during bootstrap.
3062 if (s
->refcount
< 0)
3068 static struct kmem_cache
*find_mergeable(size_t size
,
3069 size_t align
, unsigned long flags
, const char *name
,
3070 void (*ctor
)(void *))
3072 struct kmem_cache
*s
;
3074 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3080 size
= ALIGN(size
, sizeof(void *));
3081 align
= calculate_alignment(flags
, align
, size
);
3082 size
= ALIGN(size
, align
);
3083 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3085 list_for_each_entry(s
, &slab_caches
, list
) {
3086 if (slab_unmergeable(s
))
3092 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3095 * Check if alignment is compatible.
3096 * Courtesy of Adrian Drzewiecki
3098 if ((s
->size
& ~(align
- 1)) != s
->size
)
3101 if (s
->size
- size
>= sizeof(void *))
3109 struct kmem_cache
*kmem_cache_create(const char *name
, size_t size
,
3110 size_t align
, unsigned long flags
, void (*ctor
)(void *))
3112 struct kmem_cache
*s
;
3114 down_write(&slub_lock
);
3115 s
= find_mergeable(size
, align
, flags
, name
, ctor
);
3121 * Adjust the object sizes so that we clear
3122 * the complete object on kzalloc.
3124 s
->objsize
= max(s
->objsize
, (int)size
);
3127 * And then we need to update the object size in the
3128 * per cpu structures
3130 for_each_online_cpu(cpu
)
3131 get_cpu_slab(s
, cpu
)->objsize
= s
->objsize
;
3133 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3134 up_write(&slub_lock
);
3136 if (sysfs_slab_alias(s
, name
)) {
3137 down_write(&slub_lock
);
3139 up_write(&slub_lock
);
3145 s
= kmalloc(kmem_size
, GFP_KERNEL
);
3147 if (kmem_cache_open(s
, GFP_KERNEL
, name
,
3148 size
, align
, flags
, ctor
)) {
3149 list_add(&s
->list
, &slab_caches
);
3150 up_write(&slub_lock
);
3151 if (sysfs_slab_add(s
)) {
3152 down_write(&slub_lock
);
3154 up_write(&slub_lock
);
3162 up_write(&slub_lock
);
3165 if (flags
& SLAB_PANIC
)
3166 panic("Cannot create slabcache %s\n", name
);
3171 EXPORT_SYMBOL(kmem_cache_create
);
3175 * Use the cpu notifier to insure that the cpu slabs are flushed when
3178 static int __cpuinit
slab_cpuup_callback(struct notifier_block
*nfb
,
3179 unsigned long action
, void *hcpu
)
3181 long cpu
= (long)hcpu
;
3182 struct kmem_cache
*s
;
3183 unsigned long flags
;
3186 case CPU_UP_PREPARE
:
3187 case CPU_UP_PREPARE_FROZEN
:
3188 init_alloc_cpu_cpu(cpu
);
3189 down_read(&slub_lock
);
3190 list_for_each_entry(s
, &slab_caches
, list
)
3191 s
->cpu_slab
[cpu
] = alloc_kmem_cache_cpu(s
, cpu
,
3193 up_read(&slub_lock
);
3196 case CPU_UP_CANCELED
:
3197 case CPU_UP_CANCELED_FROZEN
:
3199 case CPU_DEAD_FROZEN
:
3200 down_read(&slub_lock
);
3201 list_for_each_entry(s
, &slab_caches
, list
) {
3202 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
3204 local_irq_save(flags
);
3205 __flush_cpu_slab(s
, cpu
);
3206 local_irq_restore(flags
);
3207 free_kmem_cache_cpu(c
, cpu
);
3208 s
->cpu_slab
[cpu
] = NULL
;
3210 up_read(&slub_lock
);
3218 static struct notifier_block __cpuinitdata slab_notifier
= {
3219 .notifier_call
= slab_cpuup_callback
3224 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, unsigned long caller
)
3226 struct kmem_cache
*s
;
3228 if (unlikely(size
> PAGE_SIZE
))
3229 return kmalloc_large(size
, gfpflags
);
3231 s
= get_slab(size
, gfpflags
);
3233 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3236 return slab_alloc(s
, gfpflags
, -1, caller
);
3239 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3240 int node
, unsigned long caller
)
3242 struct kmem_cache
*s
;
3244 if (unlikely(size
> PAGE_SIZE
))
3245 return kmalloc_large_node(size
, gfpflags
, node
);
3247 s
= get_slab(size
, gfpflags
);
3249 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3252 return slab_alloc(s
, gfpflags
, node
, caller
);
3255 #ifdef CONFIG_SLUB_DEBUG
3256 static unsigned long count_partial(struct kmem_cache_node
*n
,
3257 int (*get_count
)(struct page
*))
3259 unsigned long flags
;
3260 unsigned long x
= 0;
3263 spin_lock_irqsave(&n
->list_lock
, flags
);
3264 list_for_each_entry(page
, &n
->partial
, lru
)
3265 x
+= get_count(page
);
3266 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3270 static int count_inuse(struct page
*page
)
3275 static int count_total(struct page
*page
)
3277 return page
->objects
;
3280 static int count_free(struct page
*page
)
3282 return page
->objects
- page
->inuse
;
3285 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3289 void *addr
= page_address(page
);
3291 if (!check_slab(s
, page
) ||
3292 !on_freelist(s
, page
, NULL
))
3295 /* Now we know that a valid freelist exists */
3296 bitmap_zero(map
, page
->objects
);
3298 for_each_free_object(p
, s
, page
->freelist
) {
3299 set_bit(slab_index(p
, s
, addr
), map
);
3300 if (!check_object(s
, page
, p
, 0))
3304 for_each_object(p
, s
, addr
, page
->objects
)
3305 if (!test_bit(slab_index(p
, s
, addr
), map
))
3306 if (!check_object(s
, page
, p
, 1))
3311 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
3314 if (slab_trylock(page
)) {
3315 validate_slab(s
, page
, map
);
3318 printk(KERN_INFO
"SLUB %s: Skipped busy slab 0x%p\n",
3321 if (s
->flags
& DEBUG_DEFAULT_FLAGS
) {
3322 if (!PageSlubDebug(page
))
3323 printk(KERN_ERR
"SLUB %s: SlubDebug not set "
3324 "on slab 0x%p\n", s
->name
, page
);
3326 if (PageSlubDebug(page
))
3327 printk(KERN_ERR
"SLUB %s: SlubDebug set on "
3328 "slab 0x%p\n", s
->name
, page
);
3332 static int validate_slab_node(struct kmem_cache
*s
,
3333 struct kmem_cache_node
*n
, unsigned long *map
)
3335 unsigned long count
= 0;
3337 unsigned long flags
;
3339 spin_lock_irqsave(&n
->list_lock
, flags
);
3341 list_for_each_entry(page
, &n
->partial
, lru
) {
3342 validate_slab_slab(s
, page
, map
);
3345 if (count
!= n
->nr_partial
)
3346 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
3347 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
3349 if (!(s
->flags
& SLAB_STORE_USER
))
3352 list_for_each_entry(page
, &n
->full
, lru
) {
3353 validate_slab_slab(s
, page
, map
);
3356 if (count
!= atomic_long_read(&n
->nr_slabs
))
3357 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
3358 "counter=%ld\n", s
->name
, count
,
3359 atomic_long_read(&n
->nr_slabs
));
3362 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3366 static long validate_slab_cache(struct kmem_cache
*s
)
3369 unsigned long count
= 0;
3370 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
3371 sizeof(unsigned long), GFP_KERNEL
);
3377 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3378 struct kmem_cache_node
*n
= get_node(s
, node
);
3380 count
+= validate_slab_node(s
, n
, map
);
3386 #ifdef SLUB_RESILIENCY_TEST
3387 static void resiliency_test(void)
3391 printk(KERN_ERR
"SLUB resiliency testing\n");
3392 printk(KERN_ERR
"-----------------------\n");
3393 printk(KERN_ERR
"A. Corruption after allocation\n");
3395 p
= kzalloc(16, GFP_KERNEL
);
3397 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
3398 " 0x12->0x%p\n\n", p
+ 16);
3400 validate_slab_cache(kmalloc_caches
+ 4);
3402 /* Hmmm... The next two are dangerous */
3403 p
= kzalloc(32, GFP_KERNEL
);
3404 p
[32 + sizeof(void *)] = 0x34;
3405 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
3406 " 0x34 -> -0x%p\n", p
);
3408 "If allocated object is overwritten then not detectable\n\n");
3410 validate_slab_cache(kmalloc_caches
+ 5);
3411 p
= kzalloc(64, GFP_KERNEL
);
3412 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
3414 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3417 "If allocated object is overwritten then not detectable\n\n");
3418 validate_slab_cache(kmalloc_caches
+ 6);
3420 printk(KERN_ERR
"\nB. Corruption after free\n");
3421 p
= kzalloc(128, GFP_KERNEL
);
3424 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
3425 validate_slab_cache(kmalloc_caches
+ 7);
3427 p
= kzalloc(256, GFP_KERNEL
);
3430 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3432 validate_slab_cache(kmalloc_caches
+ 8);
3434 p
= kzalloc(512, GFP_KERNEL
);
3437 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
3438 validate_slab_cache(kmalloc_caches
+ 9);
3441 static void resiliency_test(void) {};
3445 * Generate lists of code addresses where slabcache objects are allocated
3450 unsigned long count
;
3457 DECLARE_BITMAP(cpus
, NR_CPUS
);
3463 unsigned long count
;
3464 struct location
*loc
;
3467 static void free_loc_track(struct loc_track
*t
)
3470 free_pages((unsigned long)t
->loc
,
3471 get_order(sizeof(struct location
) * t
->max
));
3474 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
3479 order
= get_order(sizeof(struct location
) * max
);
3481 l
= (void *)__get_free_pages(flags
, order
);
3486 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
3494 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
3495 const struct track
*track
)
3497 long start
, end
, pos
;
3499 unsigned long caddr
;
3500 unsigned long age
= jiffies
- track
->when
;
3506 pos
= start
+ (end
- start
+ 1) / 2;
3509 * There is nothing at "end". If we end up there
3510 * we need to add something to before end.
3515 caddr
= t
->loc
[pos
].addr
;
3516 if (track
->addr
== caddr
) {
3522 if (age
< l
->min_time
)
3524 if (age
> l
->max_time
)
3527 if (track
->pid
< l
->min_pid
)
3528 l
->min_pid
= track
->pid
;
3529 if (track
->pid
> l
->max_pid
)
3530 l
->max_pid
= track
->pid
;
3532 cpumask_set_cpu(track
->cpu
,
3533 to_cpumask(l
->cpus
));
3535 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
3539 if (track
->addr
< caddr
)
3546 * Not found. Insert new tracking element.
3548 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
3554 (t
->count
- pos
) * sizeof(struct location
));
3557 l
->addr
= track
->addr
;
3561 l
->min_pid
= track
->pid
;
3562 l
->max_pid
= track
->pid
;
3563 cpumask_clear(to_cpumask(l
->cpus
));
3564 cpumask_set_cpu(track
->cpu
, to_cpumask(l
->cpus
));
3565 nodes_clear(l
->nodes
);
3566 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
3570 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
3571 struct page
*page
, enum track_item alloc
)
3573 void *addr
= page_address(page
);
3574 DECLARE_BITMAP(map
, page
->objects
);
3577 bitmap_zero(map
, page
->objects
);
3578 for_each_free_object(p
, s
, page
->freelist
)
3579 set_bit(slab_index(p
, s
, addr
), map
);
3581 for_each_object(p
, s
, addr
, page
->objects
)
3582 if (!test_bit(slab_index(p
, s
, addr
), map
))
3583 add_location(t
, s
, get_track(s
, p
, alloc
));
3586 static int list_locations(struct kmem_cache
*s
, char *buf
,
3587 enum track_item alloc
)
3591 struct loc_track t
= { 0, 0, NULL
};
3594 if (!alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
3596 return sprintf(buf
, "Out of memory\n");
3598 /* Push back cpu slabs */
3601 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3602 struct kmem_cache_node
*n
= get_node(s
, node
);
3603 unsigned long flags
;
3606 if (!atomic_long_read(&n
->nr_slabs
))
3609 spin_lock_irqsave(&n
->list_lock
, flags
);
3610 list_for_each_entry(page
, &n
->partial
, lru
)
3611 process_slab(&t
, s
, page
, alloc
);
3612 list_for_each_entry(page
, &n
->full
, lru
)
3613 process_slab(&t
, s
, page
, alloc
);
3614 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3617 for (i
= 0; i
< t
.count
; i
++) {
3618 struct location
*l
= &t
.loc
[i
];
3620 if (len
> PAGE_SIZE
- KSYM_SYMBOL_LEN
- 100)
3622 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
3625 len
+= sprint_symbol(buf
+ len
, (unsigned long)l
->addr
);
3627 len
+= sprintf(buf
+ len
, "<not-available>");
3629 if (l
->sum_time
!= l
->min_time
) {
3630 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
3632 (long)div_u64(l
->sum_time
, l
->count
),
3635 len
+= sprintf(buf
+ len
, " age=%ld",
3638 if (l
->min_pid
!= l
->max_pid
)
3639 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
3640 l
->min_pid
, l
->max_pid
);
3642 len
+= sprintf(buf
+ len
, " pid=%ld",
3645 if (num_online_cpus() > 1 &&
3646 !cpumask_empty(to_cpumask(l
->cpus
)) &&
3647 len
< PAGE_SIZE
- 60) {
3648 len
+= sprintf(buf
+ len
, " cpus=");
3649 len
+= cpulist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
3650 to_cpumask(l
->cpus
));
3653 if (num_online_nodes() > 1 && !nodes_empty(l
->nodes
) &&
3654 len
< PAGE_SIZE
- 60) {
3655 len
+= sprintf(buf
+ len
, " nodes=");
3656 len
+= nodelist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
3660 len
+= sprintf(buf
+ len
, "\n");
3665 len
+= sprintf(buf
, "No data\n");
3669 enum slab_stat_type
{
3670 SL_ALL
, /* All slabs */
3671 SL_PARTIAL
, /* Only partially allocated slabs */
3672 SL_CPU
, /* Only slabs used for cpu caches */
3673 SL_OBJECTS
, /* Determine allocated objects not slabs */
3674 SL_TOTAL
/* Determine object capacity not slabs */
3677 #define SO_ALL (1 << SL_ALL)
3678 #define SO_PARTIAL (1 << SL_PARTIAL)
3679 #define SO_CPU (1 << SL_CPU)
3680 #define SO_OBJECTS (1 << SL_OBJECTS)
3681 #define SO_TOTAL (1 << SL_TOTAL)
3683 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
3684 char *buf
, unsigned long flags
)
3686 unsigned long total
= 0;
3689 unsigned long *nodes
;
3690 unsigned long *per_cpu
;
3692 nodes
= kzalloc(2 * sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
3695 per_cpu
= nodes
+ nr_node_ids
;
3697 if (flags
& SO_CPU
) {
3700 for_each_possible_cpu(cpu
) {
3701 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
3703 if (!c
|| c
->node
< 0)
3707 if (flags
& SO_TOTAL
)
3708 x
= c
->page
->objects
;
3709 else if (flags
& SO_OBJECTS
)
3715 nodes
[c
->node
] += x
;
3721 if (flags
& SO_ALL
) {
3722 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3723 struct kmem_cache_node
*n
= get_node(s
, node
);
3725 if (flags
& SO_TOTAL
)
3726 x
= atomic_long_read(&n
->total_objects
);
3727 else if (flags
& SO_OBJECTS
)
3728 x
= atomic_long_read(&n
->total_objects
) -
3729 count_partial(n
, count_free
);
3732 x
= atomic_long_read(&n
->nr_slabs
);
3737 } else if (flags
& SO_PARTIAL
) {
3738 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3739 struct kmem_cache_node
*n
= get_node(s
, node
);
3741 if (flags
& SO_TOTAL
)
3742 x
= count_partial(n
, count_total
);
3743 else if (flags
& SO_OBJECTS
)
3744 x
= count_partial(n
, count_inuse
);
3751 x
= sprintf(buf
, "%lu", total
);
3753 for_each_node_state(node
, N_NORMAL_MEMORY
)
3755 x
+= sprintf(buf
+ x
, " N%d=%lu",
3759 return x
+ sprintf(buf
+ x
, "\n");
3762 static int any_slab_objects(struct kmem_cache
*s
)
3766 for_each_online_node(node
) {
3767 struct kmem_cache_node
*n
= get_node(s
, node
);
3772 if (atomic_long_read(&n
->total_objects
))
3778 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3779 #define to_slab(n) container_of(n, struct kmem_cache, kobj);
3781 struct slab_attribute
{
3782 struct attribute attr
;
3783 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
3784 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
3787 #define SLAB_ATTR_RO(_name) \
3788 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3790 #define SLAB_ATTR(_name) \
3791 static struct slab_attribute _name##_attr = \
3792 __ATTR(_name, 0644, _name##_show, _name##_store)
3794 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
3796 return sprintf(buf
, "%d\n", s
->size
);
3798 SLAB_ATTR_RO(slab_size
);
3800 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
3802 return sprintf(buf
, "%d\n", s
->align
);
3804 SLAB_ATTR_RO(align
);
3806 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
3808 return sprintf(buf
, "%d\n", s
->objsize
);
3810 SLAB_ATTR_RO(object_size
);
3812 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
3814 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
3816 SLAB_ATTR_RO(objs_per_slab
);
3818 static ssize_t
order_store(struct kmem_cache
*s
,
3819 const char *buf
, size_t length
)
3821 unsigned long order
;
3824 err
= strict_strtoul(buf
, 10, &order
);
3828 if (order
> slub_max_order
|| order
< slub_min_order
)
3831 calculate_sizes(s
, order
);
3835 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
3837 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
3841 static ssize_t
min_partial_show(struct kmem_cache
*s
, char *buf
)
3843 return sprintf(buf
, "%lu\n", s
->min_partial
);
3846 static ssize_t
min_partial_store(struct kmem_cache
*s
, const char *buf
,
3852 err
= strict_strtoul(buf
, 10, &min
);
3856 set_min_partial(s
, min
);
3859 SLAB_ATTR(min_partial
);
3861 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
3864 int n
= sprint_symbol(buf
, (unsigned long)s
->ctor
);
3866 return n
+ sprintf(buf
+ n
, "\n");
3872 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
3874 return sprintf(buf
, "%d\n", s
->refcount
- 1);
3876 SLAB_ATTR_RO(aliases
);
3878 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
3880 return show_slab_objects(s
, buf
, SO_ALL
);
3882 SLAB_ATTR_RO(slabs
);
3884 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
3886 return show_slab_objects(s
, buf
, SO_PARTIAL
);
3888 SLAB_ATTR_RO(partial
);
3890 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
3892 return show_slab_objects(s
, buf
, SO_CPU
);
3894 SLAB_ATTR_RO(cpu_slabs
);
3896 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
3898 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
3900 SLAB_ATTR_RO(objects
);
3902 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
3904 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
3906 SLAB_ATTR_RO(objects_partial
);
3908 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
3910 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
3912 SLAB_ATTR_RO(total_objects
);
3914 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
3916 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
3919 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
3920 const char *buf
, size_t length
)
3922 s
->flags
&= ~SLAB_DEBUG_FREE
;
3924 s
->flags
|= SLAB_DEBUG_FREE
;
3927 SLAB_ATTR(sanity_checks
);
3929 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
3931 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
3934 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
3937 s
->flags
&= ~SLAB_TRACE
;
3939 s
->flags
|= SLAB_TRACE
;
3944 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
3946 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
3949 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
3950 const char *buf
, size_t length
)
3952 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
3954 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
3957 SLAB_ATTR(reclaim_account
);
3959 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
3961 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
3963 SLAB_ATTR_RO(hwcache_align
);
3965 #ifdef CONFIG_ZONE_DMA
3966 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
3968 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
3970 SLAB_ATTR_RO(cache_dma
);
3973 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
3975 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
3977 SLAB_ATTR_RO(destroy_by_rcu
);
3979 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
3981 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
3984 static ssize_t
red_zone_store(struct kmem_cache
*s
,
3985 const char *buf
, size_t length
)
3987 if (any_slab_objects(s
))
3990 s
->flags
&= ~SLAB_RED_ZONE
;
3992 s
->flags
|= SLAB_RED_ZONE
;
3993 calculate_sizes(s
, -1);
3996 SLAB_ATTR(red_zone
);
3998 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
4000 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
4003 static ssize_t
poison_store(struct kmem_cache
*s
,
4004 const char *buf
, size_t length
)
4006 if (any_slab_objects(s
))
4009 s
->flags
&= ~SLAB_POISON
;
4011 s
->flags
|= SLAB_POISON
;
4012 calculate_sizes(s
, -1);
4017 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4019 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4022 static ssize_t
store_user_store(struct kmem_cache
*s
,
4023 const char *buf
, size_t length
)
4025 if (any_slab_objects(s
))
4028 s
->flags
&= ~SLAB_STORE_USER
;
4030 s
->flags
|= SLAB_STORE_USER
;
4031 calculate_sizes(s
, -1);
4034 SLAB_ATTR(store_user
);
4036 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4041 static ssize_t
validate_store(struct kmem_cache
*s
,
4042 const char *buf
, size_t length
)
4046 if (buf
[0] == '1') {
4047 ret
= validate_slab_cache(s
);
4053 SLAB_ATTR(validate
);
4055 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4060 static ssize_t
shrink_store(struct kmem_cache
*s
,
4061 const char *buf
, size_t length
)
4063 if (buf
[0] == '1') {
4064 int rc
= kmem_cache_shrink(s
);
4074 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4076 if (!(s
->flags
& SLAB_STORE_USER
))
4078 return list_locations(s
, buf
, TRACK_ALLOC
);
4080 SLAB_ATTR_RO(alloc_calls
);
4082 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4084 if (!(s
->flags
& SLAB_STORE_USER
))
4086 return list_locations(s
, buf
, TRACK_FREE
);
4088 SLAB_ATTR_RO(free_calls
);
4091 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4093 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4096 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4097 const char *buf
, size_t length
)
4099 unsigned long ratio
;
4102 err
= strict_strtoul(buf
, 10, &ratio
);
4107 s
->remote_node_defrag_ratio
= ratio
* 10;
4111 SLAB_ATTR(remote_node_defrag_ratio
);
4114 #ifdef CONFIG_SLUB_STATS
4115 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4117 unsigned long sum
= 0;
4120 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4125 for_each_online_cpu(cpu
) {
4126 unsigned x
= get_cpu_slab(s
, cpu
)->stat
[si
];
4132 len
= sprintf(buf
, "%lu", sum
);
4135 for_each_online_cpu(cpu
) {
4136 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4137 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4141 return len
+ sprintf(buf
+ len
, "\n");
4144 #define STAT_ATTR(si, text) \
4145 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4147 return show_stat(s, buf, si); \
4149 SLAB_ATTR_RO(text); \
4151 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4152 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4153 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4154 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4155 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4156 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4157 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4158 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4159 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4160 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4161 STAT_ATTR(FREE_SLAB
, free_slab
);
4162 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4163 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4164 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4165 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4166 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4167 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4168 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4171 static struct attribute
*slab_attrs
[] = {
4172 &slab_size_attr
.attr
,
4173 &object_size_attr
.attr
,
4174 &objs_per_slab_attr
.attr
,
4176 &min_partial_attr
.attr
,
4178 &objects_partial_attr
.attr
,
4179 &total_objects_attr
.attr
,
4182 &cpu_slabs_attr
.attr
,
4186 &sanity_checks_attr
.attr
,
4188 &hwcache_align_attr
.attr
,
4189 &reclaim_account_attr
.attr
,
4190 &destroy_by_rcu_attr
.attr
,
4191 &red_zone_attr
.attr
,
4193 &store_user_attr
.attr
,
4194 &validate_attr
.attr
,
4196 &alloc_calls_attr
.attr
,
4197 &free_calls_attr
.attr
,
4198 #ifdef CONFIG_ZONE_DMA
4199 &cache_dma_attr
.attr
,
4202 &remote_node_defrag_ratio_attr
.attr
,
4204 #ifdef CONFIG_SLUB_STATS
4205 &alloc_fastpath_attr
.attr
,
4206 &alloc_slowpath_attr
.attr
,
4207 &free_fastpath_attr
.attr
,
4208 &free_slowpath_attr
.attr
,
4209 &free_frozen_attr
.attr
,
4210 &free_add_partial_attr
.attr
,
4211 &free_remove_partial_attr
.attr
,
4212 &alloc_from_partial_attr
.attr
,
4213 &alloc_slab_attr
.attr
,
4214 &alloc_refill_attr
.attr
,
4215 &free_slab_attr
.attr
,
4216 &cpuslab_flush_attr
.attr
,
4217 &deactivate_full_attr
.attr
,
4218 &deactivate_empty_attr
.attr
,
4219 &deactivate_to_head_attr
.attr
,
4220 &deactivate_to_tail_attr
.attr
,
4221 &deactivate_remote_frees_attr
.attr
,
4222 &order_fallback_attr
.attr
,
4227 static struct attribute_group slab_attr_group
= {
4228 .attrs
= slab_attrs
,
4231 static ssize_t
slab_attr_show(struct kobject
*kobj
,
4232 struct attribute
*attr
,
4235 struct slab_attribute
*attribute
;
4236 struct kmem_cache
*s
;
4239 attribute
= to_slab_attr(attr
);
4242 if (!attribute
->show
)
4245 err
= attribute
->show(s
, buf
);
4250 static ssize_t
slab_attr_store(struct kobject
*kobj
,
4251 struct attribute
*attr
,
4252 const char *buf
, size_t len
)
4254 struct slab_attribute
*attribute
;
4255 struct kmem_cache
*s
;
4258 attribute
= to_slab_attr(attr
);
4261 if (!attribute
->store
)
4264 err
= attribute
->store(s
, buf
, len
);
4269 static void kmem_cache_release(struct kobject
*kobj
)
4271 struct kmem_cache
*s
= to_slab(kobj
);
4276 static struct sysfs_ops slab_sysfs_ops
= {
4277 .show
= slab_attr_show
,
4278 .store
= slab_attr_store
,
4281 static struct kobj_type slab_ktype
= {
4282 .sysfs_ops
= &slab_sysfs_ops
,
4283 .release
= kmem_cache_release
4286 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
4288 struct kobj_type
*ktype
= get_ktype(kobj
);
4290 if (ktype
== &slab_ktype
)
4295 static struct kset_uevent_ops slab_uevent_ops
= {
4296 .filter
= uevent_filter
,
4299 static struct kset
*slab_kset
;
4301 #define ID_STR_LENGTH 64
4303 /* Create a unique string id for a slab cache:
4305 * Format :[flags-]size
4307 static char *create_unique_id(struct kmem_cache
*s
)
4309 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
4316 * First flags affecting slabcache operations. We will only
4317 * get here for aliasable slabs so we do not need to support
4318 * too many flags. The flags here must cover all flags that
4319 * are matched during merging to guarantee that the id is
4322 if (s
->flags
& SLAB_CACHE_DMA
)
4324 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
4326 if (s
->flags
& SLAB_DEBUG_FREE
)
4330 p
+= sprintf(p
, "%07d", s
->size
);
4331 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
4335 static int sysfs_slab_add(struct kmem_cache
*s
)
4341 if (slab_state
< SYSFS
)
4342 /* Defer until later */
4345 unmergeable
= slab_unmergeable(s
);
4348 * Slabcache can never be merged so we can use the name proper.
4349 * This is typically the case for debug situations. In that
4350 * case we can catch duplicate names easily.
4352 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
4356 * Create a unique name for the slab as a target
4359 name
= create_unique_id(s
);
4362 s
->kobj
.kset
= slab_kset
;
4363 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, name
);
4365 kobject_put(&s
->kobj
);
4369 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
4372 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
4374 /* Setup first alias */
4375 sysfs_slab_alias(s
, s
->name
);
4381 static void sysfs_slab_remove(struct kmem_cache
*s
)
4383 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
4384 kobject_del(&s
->kobj
);
4385 kobject_put(&s
->kobj
);
4389 * Need to buffer aliases during bootup until sysfs becomes
4390 * available lest we lose that information.
4392 struct saved_alias
{
4393 struct kmem_cache
*s
;
4395 struct saved_alias
*next
;
4398 static struct saved_alias
*alias_list
;
4400 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
4402 struct saved_alias
*al
;
4404 if (slab_state
== SYSFS
) {
4406 * If we have a leftover link then remove it.
4408 sysfs_remove_link(&slab_kset
->kobj
, name
);
4409 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
4412 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
4418 al
->next
= alias_list
;
4423 static int __init
slab_sysfs_init(void)
4425 struct kmem_cache
*s
;
4428 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
4430 printk(KERN_ERR
"Cannot register slab subsystem.\n");
4436 list_for_each_entry(s
, &slab_caches
, list
) {
4437 err
= sysfs_slab_add(s
);
4439 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
4440 " to sysfs\n", s
->name
);
4443 while (alias_list
) {
4444 struct saved_alias
*al
= alias_list
;
4446 alias_list
= alias_list
->next
;
4447 err
= sysfs_slab_alias(al
->s
, al
->name
);
4449 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
4450 " %s to sysfs\n", s
->name
);
4458 __initcall(slab_sysfs_init
);
4462 * The /proc/slabinfo ABI
4464 #ifdef CONFIG_SLABINFO
4465 static void print_slabinfo_header(struct seq_file
*m
)
4467 seq_puts(m
, "slabinfo - version: 2.1\n");
4468 seq_puts(m
, "# name <active_objs> <num_objs> <objsize> "
4469 "<objperslab> <pagesperslab>");
4470 seq_puts(m
, " : tunables <limit> <batchcount> <sharedfactor>");
4471 seq_puts(m
, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4475 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
4479 down_read(&slub_lock
);
4481 print_slabinfo_header(m
);
4483 return seq_list_start(&slab_caches
, *pos
);
4486 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4488 return seq_list_next(p
, &slab_caches
, pos
);
4491 static void s_stop(struct seq_file
*m
, void *p
)
4493 up_read(&slub_lock
);
4496 static int s_show(struct seq_file
*m
, void *p
)
4498 unsigned long nr_partials
= 0;
4499 unsigned long nr_slabs
= 0;
4500 unsigned long nr_inuse
= 0;
4501 unsigned long nr_objs
= 0;
4502 unsigned long nr_free
= 0;
4503 struct kmem_cache
*s
;
4506 s
= list_entry(p
, struct kmem_cache
, list
);
4508 for_each_online_node(node
) {
4509 struct kmem_cache_node
*n
= get_node(s
, node
);
4514 nr_partials
+= n
->nr_partial
;
4515 nr_slabs
+= atomic_long_read(&n
->nr_slabs
);
4516 nr_objs
+= atomic_long_read(&n
->total_objects
);
4517 nr_free
+= count_partial(n
, count_free
);
4520 nr_inuse
= nr_objs
- nr_free
;
4522 seq_printf(m
, "%-17s %6lu %6lu %6u %4u %4d", s
->name
, nr_inuse
,
4523 nr_objs
, s
->size
, oo_objects(s
->oo
),
4524 (1 << oo_order(s
->oo
)));
4525 seq_printf(m
, " : tunables %4u %4u %4u", 0, 0, 0);
4526 seq_printf(m
, " : slabdata %6lu %6lu %6lu", nr_slabs
, nr_slabs
,
4532 static const struct seq_operations slabinfo_op
= {
4539 static int slabinfo_open(struct inode
*inode
, struct file
*file
)
4541 return seq_open(file
, &slabinfo_op
);
4544 static const struct file_operations proc_slabinfo_operations
= {
4545 .open
= slabinfo_open
,
4547 .llseek
= seq_lseek
,
4548 .release
= seq_release
,
4551 static int __init
slab_proc_init(void)
4553 proc_create("slabinfo",S_IWUSR
|S_IRUGO
,NULL
,&proc_slabinfo_operations
);
4556 module_init(slab_proc_init
);
4557 #endif /* CONFIG_SLABINFO */