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 <trace/kmemtrace.h>
20 #include <linux/cpu.h>
21 #include <linux/cpuset.h>
22 #include <linux/mempolicy.h>
23 #include <linux/ctype.h>
24 #include <linux/debugobjects.h>
25 #include <linux/kallsyms.h>
26 #include <linux/memory.h>
27 #include <linux/math64.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)
157 /* Internal SLUB flags */
158 #define __OBJECT_POISON 0x80000000 /* Poison object */
159 #define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
161 static int kmem_size
= sizeof(struct kmem_cache
);
164 static struct notifier_block slab_notifier
;
168 DOWN
, /* No slab functionality available */
169 PARTIAL
, /* kmem_cache_open() works but kmalloc does not */
170 UP
, /* Everything works but does not show up in sysfs */
174 /* A list of all slab caches on the system */
175 static DECLARE_RWSEM(slub_lock
);
176 static LIST_HEAD(slab_caches
);
179 * Tracking user of a slab.
182 unsigned long addr
; /* Called from address */
183 int cpu
; /* Was running on cpu */
184 int pid
; /* Pid context */
185 unsigned long when
; /* When did the operation occur */
188 enum track_item
{ TRACK_ALLOC
, TRACK_FREE
};
190 #ifdef CONFIG_SLUB_DEBUG
191 static int sysfs_slab_add(struct kmem_cache
*);
192 static int sysfs_slab_alias(struct kmem_cache
*, const char *);
193 static void sysfs_slab_remove(struct kmem_cache
*);
196 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
197 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
199 static inline void sysfs_slab_remove(struct kmem_cache
*s
)
206 static inline void stat(struct kmem_cache_cpu
*c
, enum stat_item si
)
208 #ifdef CONFIG_SLUB_STATS
213 /********************************************************************
214 * Core slab cache functions
215 *******************************************************************/
217 int slab_is_available(void)
219 return slab_state
>= UP
;
222 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
225 return s
->node
[node
];
227 return &s
->local_node
;
231 static inline struct kmem_cache_cpu
*get_cpu_slab(struct kmem_cache
*s
, int cpu
)
234 return s
->cpu_slab
[cpu
];
240 /* Verify that a pointer has an address that is valid within a slab page */
241 static inline int check_valid_pointer(struct kmem_cache
*s
,
242 struct page
*page
, const void *object
)
249 base
= page_address(page
);
250 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
251 (object
- base
) % s
->size
) {
259 * Slow version of get and set free pointer.
261 * This version requires touching the cache lines of kmem_cache which
262 * we avoid to do in the fast alloc free paths. There we obtain the offset
263 * from the page struct.
265 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
267 return *(void **)(object
+ s
->offset
);
270 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
272 *(void **)(object
+ s
->offset
) = fp
;
275 /* Loop over all objects in a slab */
276 #define for_each_object(__p, __s, __addr, __objects) \
277 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
281 #define for_each_free_object(__p, __s, __free) \
282 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
284 /* Determine object index from a given position */
285 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
287 return (p
- addr
) / s
->size
;
290 static inline struct kmem_cache_order_objects
oo_make(int order
,
293 struct kmem_cache_order_objects x
= {
294 (order
<< 16) + (PAGE_SIZE
<< order
) / size
300 static inline int oo_order(struct kmem_cache_order_objects x
)
305 static inline int oo_objects(struct kmem_cache_order_objects x
)
307 return x
.x
& ((1 << 16) - 1);
310 #ifdef CONFIG_SLUB_DEBUG
314 #ifdef CONFIG_SLUB_DEBUG_ON
315 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
317 static int slub_debug
;
320 static char *slub_debug_slabs
;
325 static void print_section(char *text
, u8
*addr
, unsigned int length
)
333 for (i
= 0; i
< length
; i
++) {
335 printk(KERN_ERR
"%8s 0x%p: ", text
, addr
+ i
);
338 printk(KERN_CONT
" %02x", addr
[i
]);
340 ascii
[offset
] = isgraph(addr
[i
]) ? addr
[i
] : '.';
342 printk(KERN_CONT
" %s\n", ascii
);
349 printk(KERN_CONT
" ");
353 printk(KERN_CONT
" %s\n", ascii
);
357 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
358 enum track_item alloc
)
363 p
= object
+ s
->offset
+ sizeof(void *);
365 p
= object
+ s
->inuse
;
370 static void set_track(struct kmem_cache
*s
, void *object
,
371 enum track_item alloc
, unsigned long addr
)
376 p
= object
+ s
->offset
+ sizeof(void *);
378 p
= object
+ s
->inuse
;
383 p
->cpu
= smp_processor_id();
384 p
->pid
= current
->pid
;
387 memset(p
, 0, sizeof(struct track
));
390 static void init_tracking(struct kmem_cache
*s
, void *object
)
392 if (!(s
->flags
& SLAB_STORE_USER
))
395 set_track(s
, object
, TRACK_FREE
, 0UL);
396 set_track(s
, object
, TRACK_ALLOC
, 0UL);
399 static void print_track(const char *s
, struct track
*t
)
404 printk(KERN_ERR
"INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
405 s
, (void *)t
->addr
, jiffies
- t
->when
, t
->cpu
, t
->pid
);
408 static void print_tracking(struct kmem_cache
*s
, void *object
)
410 if (!(s
->flags
& SLAB_STORE_USER
))
413 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
414 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
417 static void print_page_info(struct page
*page
)
419 printk(KERN_ERR
"INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
420 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
424 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
430 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
432 printk(KERN_ERR
"========================================"
433 "=====================================\n");
434 printk(KERN_ERR
"BUG %s: %s\n", s
->name
, buf
);
435 printk(KERN_ERR
"----------------------------------------"
436 "-------------------------------------\n\n");
439 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
445 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
447 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
450 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
452 unsigned int off
; /* Offset of last byte */
453 u8
*addr
= page_address(page
);
455 print_tracking(s
, p
);
457 print_page_info(page
);
459 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
460 p
, p
- addr
, get_freepointer(s
, p
));
463 print_section("Bytes b4", p
- 16, 16);
465 print_section("Object", p
, min_t(unsigned long, s
->objsize
, PAGE_SIZE
));
467 if (s
->flags
& SLAB_RED_ZONE
)
468 print_section("Redzone", p
+ s
->objsize
,
469 s
->inuse
- s
->objsize
);
472 off
= s
->offset
+ sizeof(void *);
476 if (s
->flags
& SLAB_STORE_USER
)
477 off
+= 2 * sizeof(struct track
);
480 /* Beginning of the filler is the free pointer */
481 print_section("Padding", p
+ off
, s
->size
- off
);
486 static void object_err(struct kmem_cache
*s
, struct page
*page
,
487 u8
*object
, char *reason
)
489 slab_bug(s
, "%s", reason
);
490 print_trailer(s
, page
, object
);
493 static void slab_err(struct kmem_cache
*s
, struct page
*page
, char *fmt
, ...)
499 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
501 slab_bug(s
, "%s", buf
);
502 print_page_info(page
);
506 static void init_object(struct kmem_cache
*s
, void *object
, int active
)
510 if (s
->flags
& __OBJECT_POISON
) {
511 memset(p
, POISON_FREE
, s
->objsize
- 1);
512 p
[s
->objsize
- 1] = POISON_END
;
515 if (s
->flags
& SLAB_RED_ZONE
)
516 memset(p
+ s
->objsize
,
517 active
? SLUB_RED_ACTIVE
: SLUB_RED_INACTIVE
,
518 s
->inuse
- s
->objsize
);
521 static u8
*check_bytes(u8
*start
, unsigned int value
, unsigned int bytes
)
524 if (*start
!= (u8
)value
)
532 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
533 void *from
, void *to
)
535 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
536 memset(from
, data
, to
- from
);
539 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
540 u8
*object
, char *what
,
541 u8
*start
, unsigned int value
, unsigned int bytes
)
546 fault
= check_bytes(start
, value
, bytes
);
551 while (end
> fault
&& end
[-1] == value
)
554 slab_bug(s
, "%s overwritten", what
);
555 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
556 fault
, end
- 1, fault
[0], value
);
557 print_trailer(s
, page
, object
);
559 restore_bytes(s
, what
, value
, fault
, end
);
567 * Bytes of the object to be managed.
568 * If the freepointer may overlay the object then the free
569 * pointer is the first word of the object.
571 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
574 * object + s->objsize
575 * Padding to reach word boundary. This is also used for Redzoning.
576 * Padding is extended by another word if Redzoning is enabled and
579 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
580 * 0xcc (RED_ACTIVE) for objects in use.
583 * Meta data starts here.
585 * A. Free pointer (if we cannot overwrite object on free)
586 * B. Tracking data for SLAB_STORE_USER
587 * C. Padding to reach required alignment boundary or at mininum
588 * one word if debugging is on to be able to detect writes
589 * before the word boundary.
591 * Padding is done using 0x5a (POISON_INUSE)
594 * Nothing is used beyond s->size.
596 * If slabcaches are merged then the objsize and inuse boundaries are mostly
597 * ignored. And therefore no slab options that rely on these boundaries
598 * may be used with merged slabcaches.
601 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
603 unsigned long off
= s
->inuse
; /* The end of info */
606 /* Freepointer is placed after the object. */
607 off
+= sizeof(void *);
609 if (s
->flags
& SLAB_STORE_USER
)
610 /* We also have user information there */
611 off
+= 2 * sizeof(struct track
);
616 return check_bytes_and_report(s
, page
, p
, "Object padding",
617 p
+ off
, POISON_INUSE
, s
->size
- off
);
620 /* Check the pad bytes at the end of a slab page */
621 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
629 if (!(s
->flags
& SLAB_POISON
))
632 start
= page_address(page
);
633 length
= (PAGE_SIZE
<< compound_order(page
));
634 end
= start
+ length
;
635 remainder
= length
% s
->size
;
639 fault
= check_bytes(end
- remainder
, POISON_INUSE
, remainder
);
642 while (end
> fault
&& end
[-1] == POISON_INUSE
)
645 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
646 print_section("Padding", end
- remainder
, remainder
);
648 restore_bytes(s
, "slab padding", POISON_INUSE
, start
, end
);
652 static int check_object(struct kmem_cache
*s
, struct page
*page
,
653 void *object
, int active
)
656 u8
*endobject
= object
+ s
->objsize
;
658 if (s
->flags
& SLAB_RED_ZONE
) {
660 active
? SLUB_RED_ACTIVE
: SLUB_RED_INACTIVE
;
662 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
663 endobject
, red
, s
->inuse
- s
->objsize
))
666 if ((s
->flags
& SLAB_POISON
) && s
->objsize
< s
->inuse
) {
667 check_bytes_and_report(s
, page
, p
, "Alignment padding",
668 endobject
, POISON_INUSE
, s
->inuse
- s
->objsize
);
672 if (s
->flags
& SLAB_POISON
) {
673 if (!active
&& (s
->flags
& __OBJECT_POISON
) &&
674 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
675 POISON_FREE
, s
->objsize
- 1) ||
676 !check_bytes_and_report(s
, page
, p
, "Poison",
677 p
+ s
->objsize
- 1, POISON_END
, 1)))
680 * check_pad_bytes cleans up on its own.
682 check_pad_bytes(s
, page
, p
);
685 if (!s
->offset
&& active
)
687 * Object and freepointer overlap. Cannot check
688 * freepointer while object is allocated.
692 /* Check free pointer validity */
693 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
694 object_err(s
, page
, p
, "Freepointer corrupt");
696 * No choice but to zap it and thus loose the remainder
697 * of the free objects in this slab. May cause
698 * another error because the object count is now wrong.
700 set_freepointer(s
, p
, NULL
);
706 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
710 VM_BUG_ON(!irqs_disabled());
712 if (!PageSlab(page
)) {
713 slab_err(s
, page
, "Not a valid slab page");
717 maxobj
= (PAGE_SIZE
<< compound_order(page
)) / s
->size
;
718 if (page
->objects
> maxobj
) {
719 slab_err(s
, page
, "objects %u > max %u",
720 s
->name
, page
->objects
, maxobj
);
723 if (page
->inuse
> page
->objects
) {
724 slab_err(s
, page
, "inuse %u > max %u",
725 s
->name
, page
->inuse
, page
->objects
);
728 /* Slab_pad_check fixes things up after itself */
729 slab_pad_check(s
, page
);
734 * Determine if a certain object on a page is on the freelist. Must hold the
735 * slab lock to guarantee that the chains are in a consistent state.
737 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
740 void *fp
= page
->freelist
;
742 unsigned long max_objects
;
744 while (fp
&& nr
<= page
->objects
) {
747 if (!check_valid_pointer(s
, page
, fp
)) {
749 object_err(s
, page
, object
,
750 "Freechain corrupt");
751 set_freepointer(s
, object
, NULL
);
754 slab_err(s
, page
, "Freepointer corrupt");
755 page
->freelist
= NULL
;
756 page
->inuse
= page
->objects
;
757 slab_fix(s
, "Freelist cleared");
763 fp
= get_freepointer(s
, object
);
767 max_objects
= (PAGE_SIZE
<< compound_order(page
)) / s
->size
;
768 if (max_objects
> 65535)
771 if (page
->objects
!= max_objects
) {
772 slab_err(s
, page
, "Wrong number of objects. Found %d but "
773 "should be %d", page
->objects
, max_objects
);
774 page
->objects
= max_objects
;
775 slab_fix(s
, "Number of objects adjusted.");
777 if (page
->inuse
!= page
->objects
- nr
) {
778 slab_err(s
, page
, "Wrong object count. Counter is %d but "
779 "counted were %d", page
->inuse
, page
->objects
- nr
);
780 page
->inuse
= page
->objects
- nr
;
781 slab_fix(s
, "Object count adjusted.");
783 return search
== NULL
;
786 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
,
789 if (s
->flags
& SLAB_TRACE
) {
790 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
792 alloc
? "alloc" : "free",
797 print_section("Object", (void *)object
, s
->objsize
);
804 * Tracking of fully allocated slabs for debugging purposes.
806 static void add_full(struct kmem_cache_node
*n
, struct page
*page
)
808 spin_lock(&n
->list_lock
);
809 list_add(&page
->lru
, &n
->full
);
810 spin_unlock(&n
->list_lock
);
813 static void remove_full(struct kmem_cache
*s
, struct page
*page
)
815 struct kmem_cache_node
*n
;
817 if (!(s
->flags
& SLAB_STORE_USER
))
820 n
= get_node(s
, page_to_nid(page
));
822 spin_lock(&n
->list_lock
);
823 list_del(&page
->lru
);
824 spin_unlock(&n
->list_lock
);
827 /* Tracking of the number of slabs for debugging purposes */
828 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
830 struct kmem_cache_node
*n
= get_node(s
, node
);
832 return atomic_long_read(&n
->nr_slabs
);
835 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
837 struct kmem_cache_node
*n
= get_node(s
, node
);
840 * May be called early in order to allocate a slab for the
841 * kmem_cache_node structure. Solve the chicken-egg
842 * dilemma by deferring the increment of the count during
843 * bootstrap (see early_kmem_cache_node_alloc).
845 if (!NUMA_BUILD
|| n
) {
846 atomic_long_inc(&n
->nr_slabs
);
847 atomic_long_add(objects
, &n
->total_objects
);
850 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
852 struct kmem_cache_node
*n
= get_node(s
, node
);
854 atomic_long_dec(&n
->nr_slabs
);
855 atomic_long_sub(objects
, &n
->total_objects
);
858 /* Object debug checks for alloc/free paths */
859 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
862 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
865 init_object(s
, object
, 0);
866 init_tracking(s
, object
);
869 static int alloc_debug_processing(struct kmem_cache
*s
, struct page
*page
,
870 void *object
, unsigned long addr
)
872 if (!check_slab(s
, page
))
875 if (!on_freelist(s
, page
, object
)) {
876 object_err(s
, page
, object
, "Object already allocated");
880 if (!check_valid_pointer(s
, page
, object
)) {
881 object_err(s
, page
, object
, "Freelist Pointer check fails");
885 if (!check_object(s
, page
, object
, 0))
888 /* Success perform special debug activities for allocs */
889 if (s
->flags
& SLAB_STORE_USER
)
890 set_track(s
, object
, TRACK_ALLOC
, addr
);
891 trace(s
, page
, object
, 1);
892 init_object(s
, object
, 1);
896 if (PageSlab(page
)) {
898 * If this is a slab page then lets do the best we can
899 * to avoid issues in the future. Marking all objects
900 * as used avoids touching the remaining objects.
902 slab_fix(s
, "Marking all objects used");
903 page
->inuse
= page
->objects
;
904 page
->freelist
= NULL
;
909 static int free_debug_processing(struct kmem_cache
*s
, struct page
*page
,
910 void *object
, unsigned long addr
)
912 if (!check_slab(s
, page
))
915 if (!check_valid_pointer(s
, page
, object
)) {
916 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
920 if (on_freelist(s
, page
, object
)) {
921 object_err(s
, page
, object
, "Object already free");
925 if (!check_object(s
, page
, object
, 1))
928 if (unlikely(s
!= page
->slab
)) {
929 if (!PageSlab(page
)) {
930 slab_err(s
, page
, "Attempt to free object(0x%p) "
931 "outside of slab", object
);
932 } else if (!page
->slab
) {
934 "SLUB <none>: no slab for object 0x%p.\n",
938 object_err(s
, page
, object
,
939 "page slab pointer corrupt.");
943 /* Special debug activities for freeing objects */
944 if (!PageSlubFrozen(page
) && !page
->freelist
)
945 remove_full(s
, page
);
946 if (s
->flags
& SLAB_STORE_USER
)
947 set_track(s
, object
, TRACK_FREE
, addr
);
948 trace(s
, page
, object
, 0);
949 init_object(s
, object
, 0);
953 slab_fix(s
, "Object at 0x%p not freed", object
);
957 static int __init
setup_slub_debug(char *str
)
959 slub_debug
= DEBUG_DEFAULT_FLAGS
;
960 if (*str
++ != '=' || !*str
)
962 * No options specified. Switch on full debugging.
968 * No options but restriction on slabs. This means full
969 * debugging for slabs matching a pattern.
976 * Switch off all debugging measures.
981 * Determine which debug features should be switched on
983 for (; *str
&& *str
!= ','; str
++) {
984 switch (tolower(*str
)) {
986 slub_debug
|= SLAB_DEBUG_FREE
;
989 slub_debug
|= SLAB_RED_ZONE
;
992 slub_debug
|= SLAB_POISON
;
995 slub_debug
|= SLAB_STORE_USER
;
998 slub_debug
|= SLAB_TRACE
;
1001 printk(KERN_ERR
"slub_debug option '%c' "
1002 "unknown. skipped\n", *str
);
1008 slub_debug_slabs
= str
+ 1;
1013 __setup("slub_debug", setup_slub_debug
);
1015 static unsigned long kmem_cache_flags(unsigned long objsize
,
1016 unsigned long flags
, const char *name
,
1017 void (*ctor
)(void *))
1020 * Enable debugging if selected on the kernel commandline.
1022 if (slub_debug
&& (!slub_debug_slabs
||
1023 strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
)) == 0))
1024 flags
|= slub_debug
;
1029 static inline void setup_object_debug(struct kmem_cache
*s
,
1030 struct page
*page
, void *object
) {}
1032 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1033 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1035 static inline int free_debug_processing(struct kmem_cache
*s
,
1036 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1038 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1040 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1041 void *object
, int active
) { return 1; }
1042 static inline void add_full(struct kmem_cache_node
*n
, struct page
*page
) {}
1043 static inline unsigned long kmem_cache_flags(unsigned long objsize
,
1044 unsigned long flags
, const char *name
,
1045 void (*ctor
)(void *))
1049 #define slub_debug 0
1051 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1053 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1055 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1060 * Slab allocation and freeing
1062 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1063 struct kmem_cache_order_objects oo
)
1065 int order
= oo_order(oo
);
1068 return alloc_pages(flags
, order
);
1070 return alloc_pages_node(node
, flags
, order
);
1073 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1076 struct kmem_cache_order_objects oo
= s
->oo
;
1078 flags
|= s
->allocflags
;
1080 page
= alloc_slab_page(flags
| __GFP_NOWARN
| __GFP_NORETRY
, node
,
1082 if (unlikely(!page
)) {
1085 * Allocation may have failed due to fragmentation.
1086 * Try a lower order alloc if possible
1088 page
= alloc_slab_page(flags
, node
, oo
);
1092 stat(get_cpu_slab(s
, raw_smp_processor_id()), ORDER_FALLBACK
);
1094 page
->objects
= oo_objects(oo
);
1095 mod_zone_page_state(page_zone(page
),
1096 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1097 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1103 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1106 setup_object_debug(s
, page
, object
);
1107 if (unlikely(s
->ctor
))
1111 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1118 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1120 page
= allocate_slab(s
,
1121 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1125 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1127 page
->flags
|= 1 << PG_slab
;
1128 if (s
->flags
& (SLAB_DEBUG_FREE
| SLAB_RED_ZONE
| SLAB_POISON
|
1129 SLAB_STORE_USER
| SLAB_TRACE
))
1130 __SetPageSlubDebug(page
);
1132 start
= page_address(page
);
1134 if (unlikely(s
->flags
& SLAB_POISON
))
1135 memset(start
, POISON_INUSE
, PAGE_SIZE
<< compound_order(page
));
1138 for_each_object(p
, s
, start
, page
->objects
) {
1139 setup_object(s
, page
, last
);
1140 set_freepointer(s
, last
, p
);
1143 setup_object(s
, page
, last
);
1144 set_freepointer(s
, last
, NULL
);
1146 page
->freelist
= start
;
1152 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1154 int order
= compound_order(page
);
1155 int pages
= 1 << order
;
1157 if (unlikely(SLABDEBUG
&& PageSlubDebug(page
))) {
1160 slab_pad_check(s
, page
);
1161 for_each_object(p
, s
, page_address(page
),
1163 check_object(s
, page
, p
, 0);
1164 __ClearPageSlubDebug(page
);
1167 mod_zone_page_state(page_zone(page
),
1168 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1169 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1172 __ClearPageSlab(page
);
1173 reset_page_mapcount(page
);
1174 __free_pages(page
, order
);
1177 static void rcu_free_slab(struct rcu_head
*h
)
1181 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1182 __free_slab(page
->slab
, page
);
1185 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1187 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1189 * RCU free overloads the RCU head over the LRU
1191 struct rcu_head
*head
= (void *)&page
->lru
;
1193 call_rcu(head
, rcu_free_slab
);
1195 __free_slab(s
, page
);
1198 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1200 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1205 * Per slab locking using the pagelock
1207 static __always_inline
void slab_lock(struct page
*page
)
1209 bit_spin_lock(PG_locked
, &page
->flags
);
1212 static __always_inline
void slab_unlock(struct page
*page
)
1214 __bit_spin_unlock(PG_locked
, &page
->flags
);
1217 static __always_inline
int slab_trylock(struct page
*page
)
1221 rc
= bit_spin_trylock(PG_locked
, &page
->flags
);
1226 * Management of partially allocated slabs
1228 static void add_partial(struct kmem_cache_node
*n
,
1229 struct page
*page
, int tail
)
1231 spin_lock(&n
->list_lock
);
1234 list_add_tail(&page
->lru
, &n
->partial
);
1236 list_add(&page
->lru
, &n
->partial
);
1237 spin_unlock(&n
->list_lock
);
1240 static void remove_partial(struct kmem_cache
*s
, struct page
*page
)
1242 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1244 spin_lock(&n
->list_lock
);
1245 list_del(&page
->lru
);
1247 spin_unlock(&n
->list_lock
);
1251 * Lock slab and remove from the partial list.
1253 * Must hold list_lock.
1255 static inline int lock_and_freeze_slab(struct kmem_cache_node
*n
,
1258 if (slab_trylock(page
)) {
1259 list_del(&page
->lru
);
1261 __SetPageSlubFrozen(page
);
1268 * Try to allocate a partial slab from a specific node.
1270 static struct page
*get_partial_node(struct kmem_cache_node
*n
)
1275 * Racy check. If we mistakenly see no partial slabs then we
1276 * just allocate an empty slab. If we mistakenly try to get a
1277 * partial slab and there is none available then get_partials()
1280 if (!n
|| !n
->nr_partial
)
1283 spin_lock(&n
->list_lock
);
1284 list_for_each_entry(page
, &n
->partial
, lru
)
1285 if (lock_and_freeze_slab(n
, page
))
1289 spin_unlock(&n
->list_lock
);
1294 * Get a page from somewhere. Search in increasing NUMA distances.
1296 static struct page
*get_any_partial(struct kmem_cache
*s
, gfp_t flags
)
1299 struct zonelist
*zonelist
;
1302 enum zone_type high_zoneidx
= gfp_zone(flags
);
1306 * The defrag ratio allows a configuration of the tradeoffs between
1307 * inter node defragmentation and node local allocations. A lower
1308 * defrag_ratio increases the tendency to do local allocations
1309 * instead of attempting to obtain partial slabs from other nodes.
1311 * If the defrag_ratio is set to 0 then kmalloc() always
1312 * returns node local objects. If the ratio is higher then kmalloc()
1313 * may return off node objects because partial slabs are obtained
1314 * from other nodes and filled up.
1316 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1317 * defrag_ratio = 1000) then every (well almost) allocation will
1318 * first attempt to defrag slab caches on other nodes. This means
1319 * scanning over all nodes to look for partial slabs which may be
1320 * expensive if we do it every time we are trying to find a slab
1321 * with available objects.
1323 if (!s
->remote_node_defrag_ratio
||
1324 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1327 zonelist
= node_zonelist(slab_node(current
->mempolicy
), flags
);
1328 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
1329 struct kmem_cache_node
*n
;
1331 n
= get_node(s
, zone_to_nid(zone
));
1333 if (n
&& cpuset_zone_allowed_hardwall(zone
, flags
) &&
1334 n
->nr_partial
> n
->min_partial
) {
1335 page
= get_partial_node(n
);
1345 * Get a partial page, lock it and return it.
1347 static struct page
*get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
)
1350 int searchnode
= (node
== -1) ? numa_node_id() : node
;
1352 page
= get_partial_node(get_node(s
, searchnode
));
1353 if (page
|| (flags
& __GFP_THISNODE
))
1356 return get_any_partial(s
, flags
);
1360 * Move a page back to the lists.
1362 * Must be called with the slab lock held.
1364 * On exit the slab lock will have been dropped.
1366 static void unfreeze_slab(struct kmem_cache
*s
, struct page
*page
, int tail
)
1368 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1369 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, smp_processor_id());
1371 __ClearPageSlubFrozen(page
);
1374 if (page
->freelist
) {
1375 add_partial(n
, page
, tail
);
1376 stat(c
, tail
? DEACTIVATE_TO_TAIL
: DEACTIVATE_TO_HEAD
);
1378 stat(c
, DEACTIVATE_FULL
);
1379 if (SLABDEBUG
&& PageSlubDebug(page
) &&
1380 (s
->flags
& SLAB_STORE_USER
))
1385 stat(c
, DEACTIVATE_EMPTY
);
1386 if (n
->nr_partial
< n
->min_partial
) {
1388 * Adding an empty slab to the partial slabs in order
1389 * to avoid page allocator overhead. This slab needs
1390 * to come after the other slabs with objects in
1391 * so that the others get filled first. That way the
1392 * size of the partial list stays small.
1394 * kmem_cache_shrink can reclaim any empty slabs from
1397 add_partial(n
, page
, 1);
1401 stat(get_cpu_slab(s
, raw_smp_processor_id()), FREE_SLAB
);
1402 discard_slab(s
, page
);
1408 * Remove the cpu slab
1410 static void deactivate_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1412 struct page
*page
= c
->page
;
1416 stat(c
, DEACTIVATE_REMOTE_FREES
);
1418 * Merge cpu freelist into slab freelist. Typically we get here
1419 * because both freelists are empty. So this is unlikely
1422 while (unlikely(c
->freelist
)) {
1425 tail
= 0; /* Hot objects. Put the slab first */
1427 /* Retrieve object from cpu_freelist */
1428 object
= c
->freelist
;
1429 c
->freelist
= c
->freelist
[c
->offset
];
1431 /* And put onto the regular freelist */
1432 object
[c
->offset
] = page
->freelist
;
1433 page
->freelist
= object
;
1437 unfreeze_slab(s
, page
, tail
);
1440 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1442 stat(c
, CPUSLAB_FLUSH
);
1444 deactivate_slab(s
, c
);
1450 * Called from IPI handler with interrupts disabled.
1452 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
1454 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
1456 if (likely(c
&& c
->page
))
1460 static void flush_cpu_slab(void *d
)
1462 struct kmem_cache
*s
= d
;
1464 __flush_cpu_slab(s
, smp_processor_id());
1467 static void flush_all(struct kmem_cache
*s
)
1469 on_each_cpu(flush_cpu_slab
, s
, 1);
1473 * Check if the objects in a per cpu structure fit numa
1474 * locality expectations.
1476 static inline int node_match(struct kmem_cache_cpu
*c
, int node
)
1479 if (node
!= -1 && c
->node
!= node
)
1486 * Slow path. The lockless freelist is empty or we need to perform
1489 * Interrupts are disabled.
1491 * Processing is still very fast if new objects have been freed to the
1492 * regular freelist. In that case we simply take over the regular freelist
1493 * as the lockless freelist and zap the regular freelist.
1495 * If that is not working then we fall back to the partial lists. We take the
1496 * first element of the freelist as the object to allocate now and move the
1497 * rest of the freelist to the lockless freelist.
1499 * And if we were unable to get a new slab from the partial slab lists then
1500 * we need to allocate a new slab. This is the slowest path since it involves
1501 * a call to the page allocator and the setup of a new slab.
1503 static void *__slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, int node
,
1504 unsigned long addr
, struct kmem_cache_cpu
*c
)
1509 /* We handle __GFP_ZERO in the caller */
1510 gfpflags
&= ~__GFP_ZERO
;
1516 if (unlikely(!node_match(c
, node
)))
1519 stat(c
, ALLOC_REFILL
);
1522 object
= c
->page
->freelist
;
1523 if (unlikely(!object
))
1525 if (unlikely(SLABDEBUG
&& PageSlubDebug(c
->page
)))
1528 c
->freelist
= object
[c
->offset
];
1529 c
->page
->inuse
= c
->page
->objects
;
1530 c
->page
->freelist
= NULL
;
1531 c
->node
= page_to_nid(c
->page
);
1533 slab_unlock(c
->page
);
1534 stat(c
, ALLOC_SLOWPATH
);
1538 deactivate_slab(s
, c
);
1541 new = get_partial(s
, gfpflags
, node
);
1544 stat(c
, ALLOC_FROM_PARTIAL
);
1548 if (gfpflags
& __GFP_WAIT
)
1551 new = new_slab(s
, gfpflags
, node
);
1553 if (gfpflags
& __GFP_WAIT
)
1554 local_irq_disable();
1557 c
= get_cpu_slab(s
, smp_processor_id());
1558 stat(c
, ALLOC_SLAB
);
1562 __SetPageSlubFrozen(new);
1568 if (!alloc_debug_processing(s
, c
->page
, object
, addr
))
1572 c
->page
->freelist
= object
[c
->offset
];
1578 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1579 * have the fastpath folded into their functions. So no function call
1580 * overhead for requests that can be satisfied on the fastpath.
1582 * The fastpath works by first checking if the lockless freelist can be used.
1583 * If not then __slab_alloc is called for slow processing.
1585 * Otherwise we can simply pick the next object from the lockless free list.
1587 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
1588 gfp_t gfpflags
, int node
, unsigned long addr
)
1591 struct kmem_cache_cpu
*c
;
1592 unsigned long flags
;
1593 unsigned int objsize
;
1595 local_irq_save(flags
);
1596 c
= get_cpu_slab(s
, smp_processor_id());
1597 objsize
= c
->objsize
;
1598 if (unlikely(!c
->freelist
|| !node_match(c
, node
)))
1600 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
1603 object
= c
->freelist
;
1604 c
->freelist
= object
[c
->offset
];
1605 stat(c
, ALLOC_FASTPATH
);
1607 local_irq_restore(flags
);
1609 if (unlikely((gfpflags
& __GFP_ZERO
) && object
))
1610 memset(object
, 0, objsize
);
1615 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
1617 void *ret
= slab_alloc(s
, gfpflags
, -1, _RET_IP_
);
1619 kmemtrace_mark_alloc(KMEMTRACE_TYPE_CACHE
, _RET_IP_
, ret
,
1620 s
->objsize
, s
->size
, gfpflags
);
1624 EXPORT_SYMBOL(kmem_cache_alloc
);
1626 #ifdef CONFIG_KMEMTRACE
1627 void *kmem_cache_alloc_notrace(struct kmem_cache
*s
, gfp_t gfpflags
)
1629 return slab_alloc(s
, gfpflags
, -1, _RET_IP_
);
1631 EXPORT_SYMBOL(kmem_cache_alloc_notrace
);
1635 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
1637 void *ret
= slab_alloc(s
, gfpflags
, node
, _RET_IP_
);
1639 kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_CACHE
, _RET_IP_
, ret
,
1640 s
->objsize
, s
->size
, gfpflags
, node
);
1644 EXPORT_SYMBOL(kmem_cache_alloc_node
);
1647 #ifdef CONFIG_KMEMTRACE
1648 void *kmem_cache_alloc_node_notrace(struct kmem_cache
*s
,
1652 return slab_alloc(s
, gfpflags
, node
, _RET_IP_
);
1654 EXPORT_SYMBOL(kmem_cache_alloc_node_notrace
);
1658 * Slow patch handling. This may still be called frequently since objects
1659 * have a longer lifetime than the cpu slabs in most processing loads.
1661 * So we still attempt to reduce cache line usage. Just take the slab
1662 * lock and free the item. If there is no additional partial page
1663 * handling required then we can return immediately.
1665 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
1666 void *x
, unsigned long addr
, unsigned int offset
)
1669 void **object
= (void *)x
;
1670 struct kmem_cache_cpu
*c
;
1672 c
= get_cpu_slab(s
, raw_smp_processor_id());
1673 stat(c
, FREE_SLOWPATH
);
1676 if (unlikely(SLABDEBUG
&& PageSlubDebug(page
)))
1680 prior
= object
[offset
] = page
->freelist
;
1681 page
->freelist
= object
;
1684 if (unlikely(PageSlubFrozen(page
))) {
1685 stat(c
, FREE_FROZEN
);
1689 if (unlikely(!page
->inuse
))
1693 * Objects left in the slab. If it was not on the partial list before
1696 if (unlikely(!prior
)) {
1697 add_partial(get_node(s
, page_to_nid(page
)), page
, 1);
1698 stat(c
, FREE_ADD_PARTIAL
);
1708 * Slab still on the partial list.
1710 remove_partial(s
, page
);
1711 stat(c
, FREE_REMOVE_PARTIAL
);
1715 discard_slab(s
, page
);
1719 if (!free_debug_processing(s
, page
, x
, addr
))
1725 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
1726 * can perform fastpath freeing without additional function calls.
1728 * The fastpath is only possible if we are freeing to the current cpu slab
1729 * of this processor. This typically the case if we have just allocated
1732 * If fastpath is not possible then fall back to __slab_free where we deal
1733 * with all sorts of special processing.
1735 static __always_inline
void slab_free(struct kmem_cache
*s
,
1736 struct page
*page
, void *x
, unsigned long addr
)
1738 void **object
= (void *)x
;
1739 struct kmem_cache_cpu
*c
;
1740 unsigned long flags
;
1742 local_irq_save(flags
);
1743 c
= get_cpu_slab(s
, smp_processor_id());
1744 debug_check_no_locks_freed(object
, c
->objsize
);
1745 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
1746 debug_check_no_obj_freed(object
, s
->objsize
);
1747 if (likely(page
== c
->page
&& c
->node
>= 0)) {
1748 object
[c
->offset
] = c
->freelist
;
1749 c
->freelist
= object
;
1750 stat(c
, FREE_FASTPATH
);
1752 __slab_free(s
, page
, x
, addr
, c
->offset
);
1754 local_irq_restore(flags
);
1757 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
1761 page
= virt_to_head_page(x
);
1763 slab_free(s
, page
, x
, _RET_IP_
);
1765 kmemtrace_mark_free(KMEMTRACE_TYPE_CACHE
, _RET_IP_
, x
);
1767 EXPORT_SYMBOL(kmem_cache_free
);
1769 /* Figure out on which slab object the object resides */
1770 static struct page
*get_object_page(const void *x
)
1772 struct page
*page
= virt_to_head_page(x
);
1774 if (!PageSlab(page
))
1781 * Object placement in a slab is made very easy because we always start at
1782 * offset 0. If we tune the size of the object to the alignment then we can
1783 * get the required alignment by putting one properly sized object after
1786 * Notice that the allocation order determines the sizes of the per cpu
1787 * caches. Each processor has always one slab available for allocations.
1788 * Increasing the allocation order reduces the number of times that slabs
1789 * must be moved on and off the partial lists and is therefore a factor in
1794 * Mininum / Maximum order of slab pages. This influences locking overhead
1795 * and slab fragmentation. A higher order reduces the number of partial slabs
1796 * and increases the number of allocations possible without having to
1797 * take the list_lock.
1799 static int slub_min_order
;
1800 static int slub_max_order
= PAGE_ALLOC_COSTLY_ORDER
;
1801 static int slub_min_objects
;
1804 * Merge control. If this is set then no merging of slab caches will occur.
1805 * (Could be removed. This was introduced to pacify the merge skeptics.)
1807 static int slub_nomerge
;
1810 * Calculate the order of allocation given an slab object size.
1812 * The order of allocation has significant impact on performance and other
1813 * system components. Generally order 0 allocations should be preferred since
1814 * order 0 does not cause fragmentation in the page allocator. Larger objects
1815 * be problematic to put into order 0 slabs because there may be too much
1816 * unused space left. We go to a higher order if more than 1/16th of the slab
1819 * In order to reach satisfactory performance we must ensure that a minimum
1820 * number of objects is in one slab. Otherwise we may generate too much
1821 * activity on the partial lists which requires taking the list_lock. This is
1822 * less a concern for large slabs though which are rarely used.
1824 * slub_max_order specifies the order where we begin to stop considering the
1825 * number of objects in a slab as critical. If we reach slub_max_order then
1826 * we try to keep the page order as low as possible. So we accept more waste
1827 * of space in favor of a small page order.
1829 * Higher order allocations also allow the placement of more objects in a
1830 * slab and thereby reduce object handling overhead. If the user has
1831 * requested a higher mininum order then we start with that one instead of
1832 * the smallest order which will fit the object.
1834 static inline int slab_order(int size
, int min_objects
,
1835 int max_order
, int fract_leftover
)
1839 int min_order
= slub_min_order
;
1841 if ((PAGE_SIZE
<< min_order
) / size
> 65535)
1842 return get_order(size
* 65535) - 1;
1844 for (order
= max(min_order
,
1845 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
1846 order
<= max_order
; order
++) {
1848 unsigned long slab_size
= PAGE_SIZE
<< order
;
1850 if (slab_size
< min_objects
* size
)
1853 rem
= slab_size
% size
;
1855 if (rem
<= slab_size
/ fract_leftover
)
1863 static inline int calculate_order(int size
)
1870 * Attempt to find best configuration for a slab. This
1871 * works by first attempting to generate a layout with
1872 * the best configuration and backing off gradually.
1874 * First we reduce the acceptable waste in a slab. Then
1875 * we reduce the minimum objects required in a slab.
1877 min_objects
= slub_min_objects
;
1879 min_objects
= 4 * (fls(nr_cpu_ids
) + 1);
1880 while (min_objects
> 1) {
1882 while (fraction
>= 4) {
1883 order
= slab_order(size
, min_objects
,
1884 slub_max_order
, fraction
);
1885 if (order
<= slub_max_order
)
1893 * We were unable to place multiple objects in a slab. Now
1894 * lets see if we can place a single object there.
1896 order
= slab_order(size
, 1, slub_max_order
, 1);
1897 if (order
<= slub_max_order
)
1901 * Doh this slab cannot be placed using slub_max_order.
1903 order
= slab_order(size
, 1, MAX_ORDER
, 1);
1904 if (order
<= MAX_ORDER
)
1910 * Figure out what the alignment of the objects will be.
1912 static unsigned long calculate_alignment(unsigned long flags
,
1913 unsigned long align
, unsigned long size
)
1916 * If the user wants hardware cache aligned objects then follow that
1917 * suggestion if the object is sufficiently large.
1919 * The hardware cache alignment cannot override the specified
1920 * alignment though. If that is greater then use it.
1922 if (flags
& SLAB_HWCACHE_ALIGN
) {
1923 unsigned long ralign
= cache_line_size();
1924 while (size
<= ralign
/ 2)
1926 align
= max(align
, ralign
);
1929 if (align
< ARCH_SLAB_MINALIGN
)
1930 align
= ARCH_SLAB_MINALIGN
;
1932 return ALIGN(align
, sizeof(void *));
1935 static void init_kmem_cache_cpu(struct kmem_cache
*s
,
1936 struct kmem_cache_cpu
*c
)
1941 c
->offset
= s
->offset
/ sizeof(void *);
1942 c
->objsize
= s
->objsize
;
1943 #ifdef CONFIG_SLUB_STATS
1944 memset(c
->stat
, 0, NR_SLUB_STAT_ITEMS
* sizeof(unsigned));
1949 init_kmem_cache_node(struct kmem_cache_node
*n
, struct kmem_cache
*s
)
1954 * The larger the object size is, the more pages we want on the partial
1955 * list to avoid pounding the page allocator excessively.
1957 n
->min_partial
= ilog2(s
->size
);
1958 if (n
->min_partial
< MIN_PARTIAL
)
1959 n
->min_partial
= MIN_PARTIAL
;
1960 else if (n
->min_partial
> MAX_PARTIAL
)
1961 n
->min_partial
= MAX_PARTIAL
;
1963 spin_lock_init(&n
->list_lock
);
1964 INIT_LIST_HEAD(&n
->partial
);
1965 #ifdef CONFIG_SLUB_DEBUG
1966 atomic_long_set(&n
->nr_slabs
, 0);
1967 atomic_long_set(&n
->total_objects
, 0);
1968 INIT_LIST_HEAD(&n
->full
);
1974 * Per cpu array for per cpu structures.
1976 * The per cpu array places all kmem_cache_cpu structures from one processor
1977 * close together meaning that it becomes possible that multiple per cpu
1978 * structures are contained in one cacheline. This may be particularly
1979 * beneficial for the kmalloc caches.
1981 * A desktop system typically has around 60-80 slabs. With 100 here we are
1982 * likely able to get per cpu structures for all caches from the array defined
1983 * here. We must be able to cover all kmalloc caches during bootstrap.
1985 * If the per cpu array is exhausted then fall back to kmalloc
1986 * of individual cachelines. No sharing is possible then.
1988 #define NR_KMEM_CACHE_CPU 100
1990 static DEFINE_PER_CPU(struct kmem_cache_cpu
,
1991 kmem_cache_cpu
)[NR_KMEM_CACHE_CPU
];
1993 static DEFINE_PER_CPU(struct kmem_cache_cpu
*, kmem_cache_cpu_free
);
1994 static cpumask_t kmem_cach_cpu_free_init_once
= CPU_MASK_NONE
;
1996 static struct kmem_cache_cpu
*alloc_kmem_cache_cpu(struct kmem_cache
*s
,
1997 int cpu
, gfp_t flags
)
1999 struct kmem_cache_cpu
*c
= per_cpu(kmem_cache_cpu_free
, cpu
);
2002 per_cpu(kmem_cache_cpu_free
, cpu
) =
2003 (void *)c
->freelist
;
2005 /* Table overflow: So allocate ourselves */
2007 ALIGN(sizeof(struct kmem_cache_cpu
), cache_line_size()),
2008 flags
, cpu_to_node(cpu
));
2013 init_kmem_cache_cpu(s
, c
);
2017 static void free_kmem_cache_cpu(struct kmem_cache_cpu
*c
, int cpu
)
2019 if (c
< per_cpu(kmem_cache_cpu
, cpu
) ||
2020 c
> per_cpu(kmem_cache_cpu
, cpu
) + NR_KMEM_CACHE_CPU
) {
2024 c
->freelist
= (void *)per_cpu(kmem_cache_cpu_free
, cpu
);
2025 per_cpu(kmem_cache_cpu_free
, cpu
) = c
;
2028 static void free_kmem_cache_cpus(struct kmem_cache
*s
)
2032 for_each_online_cpu(cpu
) {
2033 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
2036 s
->cpu_slab
[cpu
] = NULL
;
2037 free_kmem_cache_cpu(c
, cpu
);
2042 static int alloc_kmem_cache_cpus(struct kmem_cache
*s
, gfp_t flags
)
2046 for_each_online_cpu(cpu
) {
2047 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
2052 c
= alloc_kmem_cache_cpu(s
, cpu
, flags
);
2054 free_kmem_cache_cpus(s
);
2057 s
->cpu_slab
[cpu
] = c
;
2063 * Initialize the per cpu array.
2065 static void init_alloc_cpu_cpu(int cpu
)
2069 if (cpu_isset(cpu
, kmem_cach_cpu_free_init_once
))
2072 for (i
= NR_KMEM_CACHE_CPU
- 1; i
>= 0; i
--)
2073 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu
, cpu
)[i
], cpu
);
2075 cpu_set(cpu
, kmem_cach_cpu_free_init_once
);
2078 static void __init
init_alloc_cpu(void)
2082 for_each_online_cpu(cpu
)
2083 init_alloc_cpu_cpu(cpu
);
2087 static inline void free_kmem_cache_cpus(struct kmem_cache
*s
) {}
2088 static inline void init_alloc_cpu(void) {}
2090 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
, gfp_t flags
)
2092 init_kmem_cache_cpu(s
, &s
->cpu_slab
);
2099 * No kmalloc_node yet so do it by hand. We know that this is the first
2100 * slab on the node for this slabcache. There are no concurrent accesses
2103 * Note that this function only works on the kmalloc_node_cache
2104 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2105 * memory on a fresh node that has no slab structures yet.
2107 static struct kmem_cache_node
*early_kmem_cache_node_alloc(gfp_t gfpflags
,
2111 struct kmem_cache_node
*n
;
2112 unsigned long flags
;
2114 BUG_ON(kmalloc_caches
->size
< sizeof(struct kmem_cache_node
));
2116 page
= new_slab(kmalloc_caches
, gfpflags
, node
);
2119 if (page_to_nid(page
) != node
) {
2120 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2122 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2123 "in order to be able to continue\n");
2128 page
->freelist
= get_freepointer(kmalloc_caches
, n
);
2130 kmalloc_caches
->node
[node
] = n
;
2131 #ifdef CONFIG_SLUB_DEBUG
2132 init_object(kmalloc_caches
, n
, 1);
2133 init_tracking(kmalloc_caches
, n
);
2135 init_kmem_cache_node(n
, kmalloc_caches
);
2136 inc_slabs_node(kmalloc_caches
, node
, page
->objects
);
2139 * lockdep requires consistent irq usage for each lock
2140 * so even though there cannot be a race this early in
2141 * the boot sequence, we still disable irqs.
2143 local_irq_save(flags
);
2144 add_partial(n
, page
, 0);
2145 local_irq_restore(flags
);
2149 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2153 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2154 struct kmem_cache_node
*n
= s
->node
[node
];
2155 if (n
&& n
!= &s
->local_node
)
2156 kmem_cache_free(kmalloc_caches
, n
);
2157 s
->node
[node
] = NULL
;
2161 static int init_kmem_cache_nodes(struct kmem_cache
*s
, gfp_t gfpflags
)
2166 if (slab_state
>= UP
)
2167 local_node
= page_to_nid(virt_to_page(s
));
2171 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2172 struct kmem_cache_node
*n
;
2174 if (local_node
== node
)
2177 if (slab_state
== DOWN
) {
2178 n
= early_kmem_cache_node_alloc(gfpflags
,
2182 n
= kmem_cache_alloc_node(kmalloc_caches
,
2186 free_kmem_cache_nodes(s
);
2192 init_kmem_cache_node(n
, s
);
2197 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2201 static int init_kmem_cache_nodes(struct kmem_cache
*s
, gfp_t gfpflags
)
2203 init_kmem_cache_node(&s
->local_node
, s
);
2209 * calculate_sizes() determines the order and the distribution of data within
2212 static int calculate_sizes(struct kmem_cache
*s
, int forced_order
)
2214 unsigned long flags
= s
->flags
;
2215 unsigned long size
= s
->objsize
;
2216 unsigned long align
= s
->align
;
2220 * Round up object size to the next word boundary. We can only
2221 * place the free pointer at word boundaries and this determines
2222 * the possible location of the free pointer.
2224 size
= ALIGN(size
, sizeof(void *));
2226 #ifdef CONFIG_SLUB_DEBUG
2228 * Determine if we can poison the object itself. If the user of
2229 * the slab may touch the object after free or before allocation
2230 * then we should never poison the object itself.
2232 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2234 s
->flags
|= __OBJECT_POISON
;
2236 s
->flags
&= ~__OBJECT_POISON
;
2240 * If we are Redzoning then check if there is some space between the
2241 * end of the object and the free pointer. If not then add an
2242 * additional word to have some bytes to store Redzone information.
2244 if ((flags
& SLAB_RED_ZONE
) && size
== s
->objsize
)
2245 size
+= sizeof(void *);
2249 * With that we have determined the number of bytes in actual use
2250 * by the object. This is the potential offset to the free pointer.
2254 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
2257 * Relocate free pointer after the object if it is not
2258 * permitted to overwrite the first word of the object on
2261 * This is the case if we do RCU, have a constructor or
2262 * destructor or are poisoning the objects.
2265 size
+= sizeof(void *);
2268 #ifdef CONFIG_SLUB_DEBUG
2269 if (flags
& SLAB_STORE_USER
)
2271 * Need to store information about allocs and frees after
2274 size
+= 2 * sizeof(struct track
);
2276 if (flags
& SLAB_RED_ZONE
)
2278 * Add some empty padding so that we can catch
2279 * overwrites from earlier objects rather than let
2280 * tracking information or the free pointer be
2281 * corrupted if an user writes before the start
2284 size
+= sizeof(void *);
2288 * Determine the alignment based on various parameters that the
2289 * user specified and the dynamic determination of cache line size
2292 align
= calculate_alignment(flags
, align
, s
->objsize
);
2295 * SLUB stores one object immediately after another beginning from
2296 * offset 0. In order to align the objects we have to simply size
2297 * each object to conform to the alignment.
2299 size
= ALIGN(size
, align
);
2301 if (forced_order
>= 0)
2302 order
= forced_order
;
2304 order
= calculate_order(size
);
2311 s
->allocflags
|= __GFP_COMP
;
2313 if (s
->flags
& SLAB_CACHE_DMA
)
2314 s
->allocflags
|= SLUB_DMA
;
2316 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
2317 s
->allocflags
|= __GFP_RECLAIMABLE
;
2320 * Determine the number of objects per slab
2322 s
->oo
= oo_make(order
, size
);
2323 s
->min
= oo_make(get_order(size
), size
);
2324 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
2327 return !!oo_objects(s
->oo
);
2331 static int kmem_cache_open(struct kmem_cache
*s
, gfp_t gfpflags
,
2332 const char *name
, size_t size
,
2333 size_t align
, unsigned long flags
,
2334 void (*ctor
)(void *))
2336 memset(s
, 0, kmem_size
);
2341 s
->flags
= kmem_cache_flags(size
, flags
, name
, ctor
);
2343 if (!calculate_sizes(s
, -1))
2348 s
->remote_node_defrag_ratio
= 1000;
2350 if (!init_kmem_cache_nodes(s
, gfpflags
& ~SLUB_DMA
))
2353 if (alloc_kmem_cache_cpus(s
, gfpflags
& ~SLUB_DMA
))
2355 free_kmem_cache_nodes(s
);
2357 if (flags
& SLAB_PANIC
)
2358 panic("Cannot create slab %s size=%lu realsize=%u "
2359 "order=%u offset=%u flags=%lx\n",
2360 s
->name
, (unsigned long)size
, s
->size
, oo_order(s
->oo
),
2366 * Check if a given pointer is valid
2368 int kmem_ptr_validate(struct kmem_cache
*s
, const void *object
)
2372 page
= get_object_page(object
);
2374 if (!page
|| s
!= page
->slab
)
2375 /* No slab or wrong slab */
2378 if (!check_valid_pointer(s
, page
, object
))
2382 * We could also check if the object is on the slabs freelist.
2383 * But this would be too expensive and it seems that the main
2384 * purpose of kmem_ptr_valid() is to check if the object belongs
2385 * to a certain slab.
2389 EXPORT_SYMBOL(kmem_ptr_validate
);
2392 * Determine the size of a slab object
2394 unsigned int kmem_cache_size(struct kmem_cache
*s
)
2398 EXPORT_SYMBOL(kmem_cache_size
);
2400 const char *kmem_cache_name(struct kmem_cache
*s
)
2404 EXPORT_SYMBOL(kmem_cache_name
);
2406 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
2409 #ifdef CONFIG_SLUB_DEBUG
2410 void *addr
= page_address(page
);
2412 DECLARE_BITMAP(map
, page
->objects
);
2414 bitmap_zero(map
, page
->objects
);
2415 slab_err(s
, page
, "%s", text
);
2417 for_each_free_object(p
, s
, page
->freelist
)
2418 set_bit(slab_index(p
, s
, addr
), map
);
2420 for_each_object(p
, s
, addr
, page
->objects
) {
2422 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
2423 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
2425 print_tracking(s
, p
);
2433 * Attempt to free all partial slabs on a node.
2435 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
2437 unsigned long flags
;
2438 struct page
*page
, *h
;
2440 spin_lock_irqsave(&n
->list_lock
, flags
);
2441 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
2443 list_del(&page
->lru
);
2444 discard_slab(s
, page
);
2447 list_slab_objects(s
, page
,
2448 "Objects remaining on kmem_cache_close()");
2451 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2455 * Release all resources used by a slab cache.
2457 static inline int kmem_cache_close(struct kmem_cache
*s
)
2463 /* Attempt to free all objects */
2464 free_kmem_cache_cpus(s
);
2465 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2466 struct kmem_cache_node
*n
= get_node(s
, node
);
2469 if (n
->nr_partial
|| slabs_node(s
, node
))
2472 free_kmem_cache_nodes(s
);
2477 * Close a cache and release the kmem_cache structure
2478 * (must be used for caches created using kmem_cache_create)
2480 void kmem_cache_destroy(struct kmem_cache
*s
)
2482 down_write(&slub_lock
);
2486 up_write(&slub_lock
);
2487 if (kmem_cache_close(s
)) {
2488 printk(KERN_ERR
"SLUB %s: %s called for cache that "
2489 "still has objects.\n", s
->name
, __func__
);
2492 sysfs_slab_remove(s
);
2494 up_write(&slub_lock
);
2496 EXPORT_SYMBOL(kmem_cache_destroy
);
2498 /********************************************************************
2500 *******************************************************************/
2502 struct kmem_cache kmalloc_caches
[PAGE_SHIFT
+ 1] __cacheline_aligned
;
2503 EXPORT_SYMBOL(kmalloc_caches
);
2505 static int __init
setup_slub_min_order(char *str
)
2507 get_option(&str
, &slub_min_order
);
2512 __setup("slub_min_order=", setup_slub_min_order
);
2514 static int __init
setup_slub_max_order(char *str
)
2516 get_option(&str
, &slub_max_order
);
2521 __setup("slub_max_order=", setup_slub_max_order
);
2523 static int __init
setup_slub_min_objects(char *str
)
2525 get_option(&str
, &slub_min_objects
);
2530 __setup("slub_min_objects=", setup_slub_min_objects
);
2532 static int __init
setup_slub_nomerge(char *str
)
2538 __setup("slub_nomerge", setup_slub_nomerge
);
2540 static struct kmem_cache
*create_kmalloc_cache(struct kmem_cache
*s
,
2541 const char *name
, int size
, gfp_t gfp_flags
)
2543 unsigned int flags
= 0;
2545 if (gfp_flags
& SLUB_DMA
)
2546 flags
= SLAB_CACHE_DMA
;
2548 down_write(&slub_lock
);
2549 if (!kmem_cache_open(s
, gfp_flags
, name
, size
, ARCH_KMALLOC_MINALIGN
,
2553 list_add(&s
->list
, &slab_caches
);
2554 up_write(&slub_lock
);
2555 if (sysfs_slab_add(s
))
2560 panic("Creation of kmalloc slab %s size=%d failed.\n", name
, size
);
2563 #ifdef CONFIG_ZONE_DMA
2564 static struct kmem_cache
*kmalloc_caches_dma
[PAGE_SHIFT
+ 1];
2566 static void sysfs_add_func(struct work_struct
*w
)
2568 struct kmem_cache
*s
;
2570 down_write(&slub_lock
);
2571 list_for_each_entry(s
, &slab_caches
, list
) {
2572 if (s
->flags
& __SYSFS_ADD_DEFERRED
) {
2573 s
->flags
&= ~__SYSFS_ADD_DEFERRED
;
2577 up_write(&slub_lock
);
2580 static DECLARE_WORK(sysfs_add_work
, sysfs_add_func
);
2582 static noinline
struct kmem_cache
*dma_kmalloc_cache(int index
, gfp_t flags
)
2584 struct kmem_cache
*s
;
2588 s
= kmalloc_caches_dma
[index
];
2592 /* Dynamically create dma cache */
2593 if (flags
& __GFP_WAIT
)
2594 down_write(&slub_lock
);
2596 if (!down_write_trylock(&slub_lock
))
2600 if (kmalloc_caches_dma
[index
])
2603 realsize
= kmalloc_caches
[index
].objsize
;
2604 text
= kasprintf(flags
& ~SLUB_DMA
, "kmalloc_dma-%d",
2605 (unsigned int)realsize
);
2606 s
= kmalloc(kmem_size
, flags
& ~SLUB_DMA
);
2608 if (!s
|| !text
|| !kmem_cache_open(s
, flags
, text
,
2609 realsize
, ARCH_KMALLOC_MINALIGN
,
2610 SLAB_CACHE_DMA
|__SYSFS_ADD_DEFERRED
, NULL
)) {
2616 list_add(&s
->list
, &slab_caches
);
2617 kmalloc_caches_dma
[index
] = s
;
2619 schedule_work(&sysfs_add_work
);
2622 up_write(&slub_lock
);
2624 return kmalloc_caches_dma
[index
];
2629 * Conversion table for small slabs sizes / 8 to the index in the
2630 * kmalloc array. This is necessary for slabs < 192 since we have non power
2631 * of two cache sizes there. The size of larger slabs can be determined using
2634 static s8 size_index
[24] = {
2661 static struct kmem_cache
*get_slab(size_t size
, gfp_t flags
)
2667 return ZERO_SIZE_PTR
;
2669 index
= size_index
[(size
- 1) / 8];
2671 index
= fls(size
- 1);
2673 #ifdef CONFIG_ZONE_DMA
2674 if (unlikely((flags
& SLUB_DMA
)))
2675 return dma_kmalloc_cache(index
, flags
);
2678 return &kmalloc_caches
[index
];
2681 void *__kmalloc(size_t size
, gfp_t flags
)
2683 struct kmem_cache
*s
;
2686 if (unlikely(size
> PAGE_SIZE
))
2687 return kmalloc_large(size
, flags
);
2689 s
= get_slab(size
, flags
);
2691 if (unlikely(ZERO_OR_NULL_PTR(s
)))
2694 ret
= slab_alloc(s
, flags
, -1, _RET_IP_
);
2696 kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC
, _RET_IP_
, ret
,
2697 size
, s
->size
, flags
);
2701 EXPORT_SYMBOL(__kmalloc
);
2703 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
2705 struct page
*page
= alloc_pages_node(node
, flags
| __GFP_COMP
,
2709 return page_address(page
);
2715 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
2717 struct kmem_cache
*s
;
2720 if (unlikely(size
> PAGE_SIZE
)) {
2721 ret
= kmalloc_large_node(size
, flags
, node
);
2723 kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC
,
2725 size
, PAGE_SIZE
<< get_order(size
),
2731 s
= get_slab(size
, flags
);
2733 if (unlikely(ZERO_OR_NULL_PTR(s
)))
2736 ret
= slab_alloc(s
, flags
, node
, _RET_IP_
);
2738 kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC
, _RET_IP_
, ret
,
2739 size
, s
->size
, flags
, node
);
2743 EXPORT_SYMBOL(__kmalloc_node
);
2746 size_t ksize(const void *object
)
2749 struct kmem_cache
*s
;
2751 if (unlikely(object
== ZERO_SIZE_PTR
))
2754 page
= virt_to_head_page(object
);
2756 if (unlikely(!PageSlab(page
))) {
2757 WARN_ON(!PageCompound(page
));
2758 return PAGE_SIZE
<< compound_order(page
);
2762 #ifdef CONFIG_SLUB_DEBUG
2764 * Debugging requires use of the padding between object
2765 * and whatever may come after it.
2767 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
2772 * If we have the need to store the freelist pointer
2773 * back there or track user information then we can
2774 * only use the space before that information.
2776 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
2779 * Else we can use all the padding etc for the allocation
2784 void kfree(const void *x
)
2787 void *object
= (void *)x
;
2789 if (unlikely(ZERO_OR_NULL_PTR(x
)))
2792 page
= virt_to_head_page(x
);
2793 if (unlikely(!PageSlab(page
))) {
2794 BUG_ON(!PageCompound(page
));
2798 slab_free(page
->slab
, page
, object
, _RET_IP_
);
2800 kmemtrace_mark_free(KMEMTRACE_TYPE_KMALLOC
, _RET_IP_
, x
);
2802 EXPORT_SYMBOL(kfree
);
2805 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2806 * the remaining slabs by the number of items in use. The slabs with the
2807 * most items in use come first. New allocations will then fill those up
2808 * and thus they can be removed from the partial lists.
2810 * The slabs with the least items are placed last. This results in them
2811 * being allocated from last increasing the chance that the last objects
2812 * are freed in them.
2814 int kmem_cache_shrink(struct kmem_cache
*s
)
2818 struct kmem_cache_node
*n
;
2821 int objects
= oo_objects(s
->max
);
2822 struct list_head
*slabs_by_inuse
=
2823 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
2824 unsigned long flags
;
2826 if (!slabs_by_inuse
)
2830 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2831 n
= get_node(s
, node
);
2836 for (i
= 0; i
< objects
; i
++)
2837 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
2839 spin_lock_irqsave(&n
->list_lock
, flags
);
2842 * Build lists indexed by the items in use in each slab.
2844 * Note that concurrent frees may occur while we hold the
2845 * list_lock. page->inuse here is the upper limit.
2847 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
2848 if (!page
->inuse
&& slab_trylock(page
)) {
2850 * Must hold slab lock here because slab_free
2851 * may have freed the last object and be
2852 * waiting to release the slab.
2854 list_del(&page
->lru
);
2857 discard_slab(s
, page
);
2859 list_move(&page
->lru
,
2860 slabs_by_inuse
+ page
->inuse
);
2865 * Rebuild the partial list with the slabs filled up most
2866 * first and the least used slabs at the end.
2868 for (i
= objects
- 1; i
>= 0; i
--)
2869 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
2871 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2874 kfree(slabs_by_inuse
);
2877 EXPORT_SYMBOL(kmem_cache_shrink
);
2879 #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2880 static int slab_mem_going_offline_callback(void *arg
)
2882 struct kmem_cache
*s
;
2884 down_read(&slub_lock
);
2885 list_for_each_entry(s
, &slab_caches
, list
)
2886 kmem_cache_shrink(s
);
2887 up_read(&slub_lock
);
2892 static void slab_mem_offline_callback(void *arg
)
2894 struct kmem_cache_node
*n
;
2895 struct kmem_cache
*s
;
2896 struct memory_notify
*marg
= arg
;
2899 offline_node
= marg
->status_change_nid
;
2902 * If the node still has available memory. we need kmem_cache_node
2905 if (offline_node
< 0)
2908 down_read(&slub_lock
);
2909 list_for_each_entry(s
, &slab_caches
, list
) {
2910 n
= get_node(s
, offline_node
);
2913 * if n->nr_slabs > 0, slabs still exist on the node
2914 * that is going down. We were unable to free them,
2915 * and offline_pages() function shoudn't call this
2916 * callback. So, we must fail.
2918 BUG_ON(slabs_node(s
, offline_node
));
2920 s
->node
[offline_node
] = NULL
;
2921 kmem_cache_free(kmalloc_caches
, n
);
2924 up_read(&slub_lock
);
2927 static int slab_mem_going_online_callback(void *arg
)
2929 struct kmem_cache_node
*n
;
2930 struct kmem_cache
*s
;
2931 struct memory_notify
*marg
= arg
;
2932 int nid
= marg
->status_change_nid
;
2936 * If the node's memory is already available, then kmem_cache_node is
2937 * already created. Nothing to do.
2943 * We are bringing a node online. No memory is available yet. We must
2944 * allocate a kmem_cache_node structure in order to bring the node
2947 down_read(&slub_lock
);
2948 list_for_each_entry(s
, &slab_caches
, list
) {
2950 * XXX: kmem_cache_alloc_node will fallback to other nodes
2951 * since memory is not yet available from the node that
2954 n
= kmem_cache_alloc(kmalloc_caches
, GFP_KERNEL
);
2959 init_kmem_cache_node(n
, s
);
2963 up_read(&slub_lock
);
2967 static int slab_memory_callback(struct notifier_block
*self
,
2968 unsigned long action
, void *arg
)
2973 case MEM_GOING_ONLINE
:
2974 ret
= slab_mem_going_online_callback(arg
);
2976 case MEM_GOING_OFFLINE
:
2977 ret
= slab_mem_going_offline_callback(arg
);
2980 case MEM_CANCEL_ONLINE
:
2981 slab_mem_offline_callback(arg
);
2984 case MEM_CANCEL_OFFLINE
:
2988 ret
= notifier_from_errno(ret
);
2994 #endif /* CONFIG_MEMORY_HOTPLUG */
2996 /********************************************************************
2997 * Basic setup of slabs
2998 *******************************************************************/
3000 void __init
kmem_cache_init(void)
3009 * Must first have the slab cache available for the allocations of the
3010 * struct kmem_cache_node's. There is special bootstrap code in
3011 * kmem_cache_open for slab_state == DOWN.
3013 create_kmalloc_cache(&kmalloc_caches
[0], "kmem_cache_node",
3014 sizeof(struct kmem_cache_node
), GFP_KERNEL
);
3015 kmalloc_caches
[0].refcount
= -1;
3018 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
3021 /* Able to allocate the per node structures */
3022 slab_state
= PARTIAL
;
3024 /* Caches that are not of the two-to-the-power-of size */
3025 if (KMALLOC_MIN_SIZE
<= 64) {
3026 create_kmalloc_cache(&kmalloc_caches
[1],
3027 "kmalloc-96", 96, GFP_KERNEL
);
3029 create_kmalloc_cache(&kmalloc_caches
[2],
3030 "kmalloc-192", 192, GFP_KERNEL
);
3034 for (i
= KMALLOC_SHIFT_LOW
; i
<= PAGE_SHIFT
; i
++) {
3035 create_kmalloc_cache(&kmalloc_caches
[i
],
3036 "kmalloc", 1 << i
, GFP_KERNEL
);
3042 * Patch up the size_index table if we have strange large alignment
3043 * requirements for the kmalloc array. This is only the case for
3044 * MIPS it seems. The standard arches will not generate any code here.
3046 * Largest permitted alignment is 256 bytes due to the way we
3047 * handle the index determination for the smaller caches.
3049 * Make sure that nothing crazy happens if someone starts tinkering
3050 * around with ARCH_KMALLOC_MINALIGN
3052 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 256 ||
3053 (KMALLOC_MIN_SIZE
& (KMALLOC_MIN_SIZE
- 1)));
3055 for (i
= 8; i
< KMALLOC_MIN_SIZE
; i
+= 8)
3056 size_index
[(i
- 1) / 8] = KMALLOC_SHIFT_LOW
;
3058 if (KMALLOC_MIN_SIZE
== 128) {
3060 * The 192 byte sized cache is not used if the alignment
3061 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3064 for (i
= 128 + 8; i
<= 192; i
+= 8)
3065 size_index
[(i
- 1) / 8] = 8;
3070 /* Provide the correct kmalloc names now that the caches are up */
3071 for (i
= KMALLOC_SHIFT_LOW
; i
<= PAGE_SHIFT
; i
++)
3072 kmalloc_caches
[i
]. name
=
3073 kasprintf(GFP_KERNEL
, "kmalloc-%d", 1 << i
);
3076 register_cpu_notifier(&slab_notifier
);
3077 kmem_size
= offsetof(struct kmem_cache
, cpu_slab
) +
3078 nr_cpu_ids
* sizeof(struct kmem_cache_cpu
*);
3080 kmem_size
= sizeof(struct kmem_cache
);
3084 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3085 " CPUs=%d, Nodes=%d\n",
3086 caches
, cache_line_size(),
3087 slub_min_order
, slub_max_order
, slub_min_objects
,
3088 nr_cpu_ids
, nr_node_ids
);
3092 * Find a mergeable slab cache
3094 static int slab_unmergeable(struct kmem_cache
*s
)
3096 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3103 * We may have set a slab to be unmergeable during bootstrap.
3105 if (s
->refcount
< 0)
3111 static struct kmem_cache
*find_mergeable(size_t size
,
3112 size_t align
, unsigned long flags
, const char *name
,
3113 void (*ctor
)(void *))
3115 struct kmem_cache
*s
;
3117 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3123 size
= ALIGN(size
, sizeof(void *));
3124 align
= calculate_alignment(flags
, align
, size
);
3125 size
= ALIGN(size
, align
);
3126 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3128 list_for_each_entry(s
, &slab_caches
, list
) {
3129 if (slab_unmergeable(s
))
3135 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3138 * Check if alignment is compatible.
3139 * Courtesy of Adrian Drzewiecki
3141 if ((s
->size
& ~(align
- 1)) != s
->size
)
3144 if (s
->size
- size
>= sizeof(void *))
3152 struct kmem_cache
*kmem_cache_create(const char *name
, size_t size
,
3153 size_t align
, unsigned long flags
, void (*ctor
)(void *))
3155 struct kmem_cache
*s
;
3157 down_write(&slub_lock
);
3158 s
= find_mergeable(size
, align
, flags
, name
, ctor
);
3164 * Adjust the object sizes so that we clear
3165 * the complete object on kzalloc.
3167 s
->objsize
= max(s
->objsize
, (int)size
);
3170 * And then we need to update the object size in the
3171 * per cpu structures
3173 for_each_online_cpu(cpu
)
3174 get_cpu_slab(s
, cpu
)->objsize
= s
->objsize
;
3176 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3177 up_write(&slub_lock
);
3179 if (sysfs_slab_alias(s
, name
))
3184 s
= kmalloc(kmem_size
, GFP_KERNEL
);
3186 if (kmem_cache_open(s
, GFP_KERNEL
, name
,
3187 size
, align
, flags
, ctor
)) {
3188 list_add(&s
->list
, &slab_caches
);
3189 up_write(&slub_lock
);
3190 if (sysfs_slab_add(s
))
3196 up_write(&slub_lock
);
3199 if (flags
& SLAB_PANIC
)
3200 panic("Cannot create slabcache %s\n", name
);
3205 EXPORT_SYMBOL(kmem_cache_create
);
3209 * Use the cpu notifier to insure that the cpu slabs are flushed when
3212 static int __cpuinit
slab_cpuup_callback(struct notifier_block
*nfb
,
3213 unsigned long action
, void *hcpu
)
3215 long cpu
= (long)hcpu
;
3216 struct kmem_cache
*s
;
3217 unsigned long flags
;
3220 case CPU_UP_PREPARE
:
3221 case CPU_UP_PREPARE_FROZEN
:
3222 init_alloc_cpu_cpu(cpu
);
3223 down_read(&slub_lock
);
3224 list_for_each_entry(s
, &slab_caches
, list
)
3225 s
->cpu_slab
[cpu
] = alloc_kmem_cache_cpu(s
, cpu
,
3227 up_read(&slub_lock
);
3230 case CPU_UP_CANCELED
:
3231 case CPU_UP_CANCELED_FROZEN
:
3233 case CPU_DEAD_FROZEN
:
3234 down_read(&slub_lock
);
3235 list_for_each_entry(s
, &slab_caches
, list
) {
3236 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
3238 local_irq_save(flags
);
3239 __flush_cpu_slab(s
, cpu
);
3240 local_irq_restore(flags
);
3241 free_kmem_cache_cpu(c
, cpu
);
3242 s
->cpu_slab
[cpu
] = NULL
;
3244 up_read(&slub_lock
);
3252 static struct notifier_block __cpuinitdata slab_notifier
= {
3253 .notifier_call
= slab_cpuup_callback
3258 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, unsigned long caller
)
3260 struct kmem_cache
*s
;
3263 if (unlikely(size
> PAGE_SIZE
))
3264 return kmalloc_large(size
, gfpflags
);
3266 s
= get_slab(size
, gfpflags
);
3268 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3271 ret
= slab_alloc(s
, gfpflags
, -1, caller
);
3273 /* Honor the call site pointer we recieved. */
3274 kmemtrace_mark_alloc(KMEMTRACE_TYPE_KMALLOC
, caller
, ret
, size
,
3280 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3281 int node
, unsigned long caller
)
3283 struct kmem_cache
*s
;
3286 if (unlikely(size
> PAGE_SIZE
))
3287 return kmalloc_large_node(size
, gfpflags
, node
);
3289 s
= get_slab(size
, gfpflags
);
3291 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3294 ret
= slab_alloc(s
, gfpflags
, node
, caller
);
3296 /* Honor the call site pointer we recieved. */
3297 kmemtrace_mark_alloc_node(KMEMTRACE_TYPE_KMALLOC
, caller
, ret
,
3298 size
, s
->size
, gfpflags
, node
);
3303 #ifdef CONFIG_SLUB_DEBUG
3304 static unsigned long count_partial(struct kmem_cache_node
*n
,
3305 int (*get_count
)(struct page
*))
3307 unsigned long flags
;
3308 unsigned long x
= 0;
3311 spin_lock_irqsave(&n
->list_lock
, flags
);
3312 list_for_each_entry(page
, &n
->partial
, lru
)
3313 x
+= get_count(page
);
3314 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3318 static int count_inuse(struct page
*page
)
3323 static int count_total(struct page
*page
)
3325 return page
->objects
;
3328 static int count_free(struct page
*page
)
3330 return page
->objects
- page
->inuse
;
3333 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3337 void *addr
= page_address(page
);
3339 if (!check_slab(s
, page
) ||
3340 !on_freelist(s
, page
, NULL
))
3343 /* Now we know that a valid freelist exists */
3344 bitmap_zero(map
, page
->objects
);
3346 for_each_free_object(p
, s
, page
->freelist
) {
3347 set_bit(slab_index(p
, s
, addr
), map
);
3348 if (!check_object(s
, page
, p
, 0))
3352 for_each_object(p
, s
, addr
, page
->objects
)
3353 if (!test_bit(slab_index(p
, s
, addr
), map
))
3354 if (!check_object(s
, page
, p
, 1))
3359 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
3362 if (slab_trylock(page
)) {
3363 validate_slab(s
, page
, map
);
3366 printk(KERN_INFO
"SLUB %s: Skipped busy slab 0x%p\n",
3369 if (s
->flags
& DEBUG_DEFAULT_FLAGS
) {
3370 if (!PageSlubDebug(page
))
3371 printk(KERN_ERR
"SLUB %s: SlubDebug not set "
3372 "on slab 0x%p\n", s
->name
, page
);
3374 if (PageSlubDebug(page
))
3375 printk(KERN_ERR
"SLUB %s: SlubDebug set on "
3376 "slab 0x%p\n", s
->name
, page
);
3380 static int validate_slab_node(struct kmem_cache
*s
,
3381 struct kmem_cache_node
*n
, unsigned long *map
)
3383 unsigned long count
= 0;
3385 unsigned long flags
;
3387 spin_lock_irqsave(&n
->list_lock
, flags
);
3389 list_for_each_entry(page
, &n
->partial
, lru
) {
3390 validate_slab_slab(s
, page
, map
);
3393 if (count
!= n
->nr_partial
)
3394 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
3395 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
3397 if (!(s
->flags
& SLAB_STORE_USER
))
3400 list_for_each_entry(page
, &n
->full
, lru
) {
3401 validate_slab_slab(s
, page
, map
);
3404 if (count
!= atomic_long_read(&n
->nr_slabs
))
3405 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
3406 "counter=%ld\n", s
->name
, count
,
3407 atomic_long_read(&n
->nr_slabs
));
3410 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3414 static long validate_slab_cache(struct kmem_cache
*s
)
3417 unsigned long count
= 0;
3418 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
3419 sizeof(unsigned long), GFP_KERNEL
);
3425 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3426 struct kmem_cache_node
*n
= get_node(s
, node
);
3428 count
+= validate_slab_node(s
, n
, map
);
3434 #ifdef SLUB_RESILIENCY_TEST
3435 static void resiliency_test(void)
3439 printk(KERN_ERR
"SLUB resiliency testing\n");
3440 printk(KERN_ERR
"-----------------------\n");
3441 printk(KERN_ERR
"A. Corruption after allocation\n");
3443 p
= kzalloc(16, GFP_KERNEL
);
3445 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
3446 " 0x12->0x%p\n\n", p
+ 16);
3448 validate_slab_cache(kmalloc_caches
+ 4);
3450 /* Hmmm... The next two are dangerous */
3451 p
= kzalloc(32, GFP_KERNEL
);
3452 p
[32 + sizeof(void *)] = 0x34;
3453 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
3454 " 0x34 -> -0x%p\n", p
);
3456 "If allocated object is overwritten then not detectable\n\n");
3458 validate_slab_cache(kmalloc_caches
+ 5);
3459 p
= kzalloc(64, GFP_KERNEL
);
3460 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
3462 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3465 "If allocated object is overwritten then not detectable\n\n");
3466 validate_slab_cache(kmalloc_caches
+ 6);
3468 printk(KERN_ERR
"\nB. Corruption after free\n");
3469 p
= kzalloc(128, GFP_KERNEL
);
3472 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
3473 validate_slab_cache(kmalloc_caches
+ 7);
3475 p
= kzalloc(256, GFP_KERNEL
);
3478 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3480 validate_slab_cache(kmalloc_caches
+ 8);
3482 p
= kzalloc(512, GFP_KERNEL
);
3485 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
3486 validate_slab_cache(kmalloc_caches
+ 9);
3489 static void resiliency_test(void) {};
3493 * Generate lists of code addresses where slabcache objects are allocated
3498 unsigned long count
;
3511 unsigned long count
;
3512 struct location
*loc
;
3515 static void free_loc_track(struct loc_track
*t
)
3518 free_pages((unsigned long)t
->loc
,
3519 get_order(sizeof(struct location
) * t
->max
));
3522 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
3527 order
= get_order(sizeof(struct location
) * max
);
3529 l
= (void *)__get_free_pages(flags
, order
);
3534 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
3542 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
3543 const struct track
*track
)
3545 long start
, end
, pos
;
3547 unsigned long caddr
;
3548 unsigned long age
= jiffies
- track
->when
;
3554 pos
= start
+ (end
- start
+ 1) / 2;
3557 * There is nothing at "end". If we end up there
3558 * we need to add something to before end.
3563 caddr
= t
->loc
[pos
].addr
;
3564 if (track
->addr
== caddr
) {
3570 if (age
< l
->min_time
)
3572 if (age
> l
->max_time
)
3575 if (track
->pid
< l
->min_pid
)
3576 l
->min_pid
= track
->pid
;
3577 if (track
->pid
> l
->max_pid
)
3578 l
->max_pid
= track
->pid
;
3580 cpu_set(track
->cpu
, l
->cpus
);
3582 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
3586 if (track
->addr
< caddr
)
3593 * Not found. Insert new tracking element.
3595 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
3601 (t
->count
- pos
) * sizeof(struct location
));
3604 l
->addr
= track
->addr
;
3608 l
->min_pid
= track
->pid
;
3609 l
->max_pid
= track
->pid
;
3610 cpus_clear(l
->cpus
);
3611 cpu_set(track
->cpu
, l
->cpus
);
3612 nodes_clear(l
->nodes
);
3613 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
3617 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
3618 struct page
*page
, enum track_item alloc
)
3620 void *addr
= page_address(page
);
3621 DECLARE_BITMAP(map
, page
->objects
);
3624 bitmap_zero(map
, page
->objects
);
3625 for_each_free_object(p
, s
, page
->freelist
)
3626 set_bit(slab_index(p
, s
, addr
), map
);
3628 for_each_object(p
, s
, addr
, page
->objects
)
3629 if (!test_bit(slab_index(p
, s
, addr
), map
))
3630 add_location(t
, s
, get_track(s
, p
, alloc
));
3633 static int list_locations(struct kmem_cache
*s
, char *buf
,
3634 enum track_item alloc
)
3638 struct loc_track t
= { 0, 0, NULL
};
3641 if (!alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
3643 return sprintf(buf
, "Out of memory\n");
3645 /* Push back cpu slabs */
3648 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3649 struct kmem_cache_node
*n
= get_node(s
, node
);
3650 unsigned long flags
;
3653 if (!atomic_long_read(&n
->nr_slabs
))
3656 spin_lock_irqsave(&n
->list_lock
, flags
);
3657 list_for_each_entry(page
, &n
->partial
, lru
)
3658 process_slab(&t
, s
, page
, alloc
);
3659 list_for_each_entry(page
, &n
->full
, lru
)
3660 process_slab(&t
, s
, page
, alloc
);
3661 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3664 for (i
= 0; i
< t
.count
; i
++) {
3665 struct location
*l
= &t
.loc
[i
];
3667 if (len
> PAGE_SIZE
- KSYM_SYMBOL_LEN
- 100)
3669 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
3672 len
+= sprint_symbol(buf
+ len
, (unsigned long)l
->addr
);
3674 len
+= sprintf(buf
+ len
, "<not-available>");
3676 if (l
->sum_time
!= l
->min_time
) {
3677 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
3679 (long)div_u64(l
->sum_time
, l
->count
),
3682 len
+= sprintf(buf
+ len
, " age=%ld",
3685 if (l
->min_pid
!= l
->max_pid
)
3686 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
3687 l
->min_pid
, l
->max_pid
);
3689 len
+= sprintf(buf
+ len
, " pid=%ld",
3692 if (num_online_cpus() > 1 && !cpus_empty(l
->cpus
) &&
3693 len
< PAGE_SIZE
- 60) {
3694 len
+= sprintf(buf
+ len
, " cpus=");
3695 len
+= cpulist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
3699 if (num_online_nodes() > 1 && !nodes_empty(l
->nodes
) &&
3700 len
< PAGE_SIZE
- 60) {
3701 len
+= sprintf(buf
+ len
, " nodes=");
3702 len
+= nodelist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
3706 len
+= sprintf(buf
+ len
, "\n");
3711 len
+= sprintf(buf
, "No data\n");
3715 enum slab_stat_type
{
3716 SL_ALL
, /* All slabs */
3717 SL_PARTIAL
, /* Only partially allocated slabs */
3718 SL_CPU
, /* Only slabs used for cpu caches */
3719 SL_OBJECTS
, /* Determine allocated objects not slabs */
3720 SL_TOTAL
/* Determine object capacity not slabs */
3723 #define SO_ALL (1 << SL_ALL)
3724 #define SO_PARTIAL (1 << SL_PARTIAL)
3725 #define SO_CPU (1 << SL_CPU)
3726 #define SO_OBJECTS (1 << SL_OBJECTS)
3727 #define SO_TOTAL (1 << SL_TOTAL)
3729 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
3730 char *buf
, unsigned long flags
)
3732 unsigned long total
= 0;
3735 unsigned long *nodes
;
3736 unsigned long *per_cpu
;
3738 nodes
= kzalloc(2 * sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
3741 per_cpu
= nodes
+ nr_node_ids
;
3743 if (flags
& SO_CPU
) {
3746 for_each_possible_cpu(cpu
) {
3747 struct kmem_cache_cpu
*c
= get_cpu_slab(s
, cpu
);
3749 if (!c
|| c
->node
< 0)
3753 if (flags
& SO_TOTAL
)
3754 x
= c
->page
->objects
;
3755 else if (flags
& SO_OBJECTS
)
3761 nodes
[c
->node
] += x
;
3767 if (flags
& SO_ALL
) {
3768 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3769 struct kmem_cache_node
*n
= get_node(s
, node
);
3771 if (flags
& SO_TOTAL
)
3772 x
= atomic_long_read(&n
->total_objects
);
3773 else if (flags
& SO_OBJECTS
)
3774 x
= atomic_long_read(&n
->total_objects
) -
3775 count_partial(n
, count_free
);
3778 x
= atomic_long_read(&n
->nr_slabs
);
3783 } else if (flags
& SO_PARTIAL
) {
3784 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3785 struct kmem_cache_node
*n
= get_node(s
, node
);
3787 if (flags
& SO_TOTAL
)
3788 x
= count_partial(n
, count_total
);
3789 else if (flags
& SO_OBJECTS
)
3790 x
= count_partial(n
, count_inuse
);
3797 x
= sprintf(buf
, "%lu", total
);
3799 for_each_node_state(node
, N_NORMAL_MEMORY
)
3801 x
+= sprintf(buf
+ x
, " N%d=%lu",
3805 return x
+ sprintf(buf
+ x
, "\n");
3808 static int any_slab_objects(struct kmem_cache
*s
)
3812 for_each_online_node(node
) {
3813 struct kmem_cache_node
*n
= get_node(s
, node
);
3818 if (atomic_long_read(&n
->total_objects
))
3824 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3825 #define to_slab(n) container_of(n, struct kmem_cache, kobj);
3827 struct slab_attribute
{
3828 struct attribute attr
;
3829 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
3830 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
3833 #define SLAB_ATTR_RO(_name) \
3834 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3836 #define SLAB_ATTR(_name) \
3837 static struct slab_attribute _name##_attr = \
3838 __ATTR(_name, 0644, _name##_show, _name##_store)
3840 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
3842 return sprintf(buf
, "%d\n", s
->size
);
3844 SLAB_ATTR_RO(slab_size
);
3846 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
3848 return sprintf(buf
, "%d\n", s
->align
);
3850 SLAB_ATTR_RO(align
);
3852 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
3854 return sprintf(buf
, "%d\n", s
->objsize
);
3856 SLAB_ATTR_RO(object_size
);
3858 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
3860 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
3862 SLAB_ATTR_RO(objs_per_slab
);
3864 static ssize_t
order_store(struct kmem_cache
*s
,
3865 const char *buf
, size_t length
)
3867 unsigned long order
;
3870 err
= strict_strtoul(buf
, 10, &order
);
3874 if (order
> slub_max_order
|| order
< slub_min_order
)
3877 calculate_sizes(s
, order
);
3881 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
3883 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
3887 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
3890 int n
= sprint_symbol(buf
, (unsigned long)s
->ctor
);
3892 return n
+ sprintf(buf
+ n
, "\n");
3898 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
3900 return sprintf(buf
, "%d\n", s
->refcount
- 1);
3902 SLAB_ATTR_RO(aliases
);
3904 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
3906 return show_slab_objects(s
, buf
, SO_ALL
);
3908 SLAB_ATTR_RO(slabs
);
3910 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
3912 return show_slab_objects(s
, buf
, SO_PARTIAL
);
3914 SLAB_ATTR_RO(partial
);
3916 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
3918 return show_slab_objects(s
, buf
, SO_CPU
);
3920 SLAB_ATTR_RO(cpu_slabs
);
3922 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
3924 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
3926 SLAB_ATTR_RO(objects
);
3928 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
3930 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
3932 SLAB_ATTR_RO(objects_partial
);
3934 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
3936 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
3938 SLAB_ATTR_RO(total_objects
);
3940 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
3942 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
3945 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
3946 const char *buf
, size_t length
)
3948 s
->flags
&= ~SLAB_DEBUG_FREE
;
3950 s
->flags
|= SLAB_DEBUG_FREE
;
3953 SLAB_ATTR(sanity_checks
);
3955 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
3957 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
3960 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
3963 s
->flags
&= ~SLAB_TRACE
;
3965 s
->flags
|= SLAB_TRACE
;
3970 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
3972 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
3975 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
3976 const char *buf
, size_t length
)
3978 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
3980 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
3983 SLAB_ATTR(reclaim_account
);
3985 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
3987 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
3989 SLAB_ATTR_RO(hwcache_align
);
3991 #ifdef CONFIG_ZONE_DMA
3992 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
3994 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
3996 SLAB_ATTR_RO(cache_dma
);
3999 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
4001 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
4003 SLAB_ATTR_RO(destroy_by_rcu
);
4005 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
4007 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
4010 static ssize_t
red_zone_store(struct kmem_cache
*s
,
4011 const char *buf
, size_t length
)
4013 if (any_slab_objects(s
))
4016 s
->flags
&= ~SLAB_RED_ZONE
;
4018 s
->flags
|= SLAB_RED_ZONE
;
4019 calculate_sizes(s
, -1);
4022 SLAB_ATTR(red_zone
);
4024 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
4026 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
4029 static ssize_t
poison_store(struct kmem_cache
*s
,
4030 const char *buf
, size_t length
)
4032 if (any_slab_objects(s
))
4035 s
->flags
&= ~SLAB_POISON
;
4037 s
->flags
|= SLAB_POISON
;
4038 calculate_sizes(s
, -1);
4043 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4045 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4048 static ssize_t
store_user_store(struct kmem_cache
*s
,
4049 const char *buf
, size_t length
)
4051 if (any_slab_objects(s
))
4054 s
->flags
&= ~SLAB_STORE_USER
;
4056 s
->flags
|= SLAB_STORE_USER
;
4057 calculate_sizes(s
, -1);
4060 SLAB_ATTR(store_user
);
4062 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4067 static ssize_t
validate_store(struct kmem_cache
*s
,
4068 const char *buf
, size_t length
)
4072 if (buf
[0] == '1') {
4073 ret
= validate_slab_cache(s
);
4079 SLAB_ATTR(validate
);
4081 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4086 static ssize_t
shrink_store(struct kmem_cache
*s
,
4087 const char *buf
, size_t length
)
4089 if (buf
[0] == '1') {
4090 int rc
= kmem_cache_shrink(s
);
4100 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4102 if (!(s
->flags
& SLAB_STORE_USER
))
4104 return list_locations(s
, buf
, TRACK_ALLOC
);
4106 SLAB_ATTR_RO(alloc_calls
);
4108 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4110 if (!(s
->flags
& SLAB_STORE_USER
))
4112 return list_locations(s
, buf
, TRACK_FREE
);
4114 SLAB_ATTR_RO(free_calls
);
4117 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4119 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4122 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4123 const char *buf
, size_t length
)
4125 unsigned long ratio
;
4128 err
= strict_strtoul(buf
, 10, &ratio
);
4133 s
->remote_node_defrag_ratio
= ratio
* 10;
4137 SLAB_ATTR(remote_node_defrag_ratio
);
4140 #ifdef CONFIG_SLUB_STATS
4141 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4143 unsigned long sum
= 0;
4146 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4151 for_each_online_cpu(cpu
) {
4152 unsigned x
= get_cpu_slab(s
, cpu
)->stat
[si
];
4158 len
= sprintf(buf
, "%lu", sum
);
4161 for_each_online_cpu(cpu
) {
4162 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4163 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4167 return len
+ sprintf(buf
+ len
, "\n");
4170 #define STAT_ATTR(si, text) \
4171 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4173 return show_stat(s, buf, si); \
4175 SLAB_ATTR_RO(text); \
4177 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4178 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4179 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4180 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4181 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4182 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4183 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4184 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4185 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4186 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4187 STAT_ATTR(FREE_SLAB
, free_slab
);
4188 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4189 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4190 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4191 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4192 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4193 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4194 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4197 static struct attribute
*slab_attrs
[] = {
4198 &slab_size_attr
.attr
,
4199 &object_size_attr
.attr
,
4200 &objs_per_slab_attr
.attr
,
4203 &objects_partial_attr
.attr
,
4204 &total_objects_attr
.attr
,
4207 &cpu_slabs_attr
.attr
,
4211 &sanity_checks_attr
.attr
,
4213 &hwcache_align_attr
.attr
,
4214 &reclaim_account_attr
.attr
,
4215 &destroy_by_rcu_attr
.attr
,
4216 &red_zone_attr
.attr
,
4218 &store_user_attr
.attr
,
4219 &validate_attr
.attr
,
4221 &alloc_calls_attr
.attr
,
4222 &free_calls_attr
.attr
,
4223 #ifdef CONFIG_ZONE_DMA
4224 &cache_dma_attr
.attr
,
4227 &remote_node_defrag_ratio_attr
.attr
,
4229 #ifdef CONFIG_SLUB_STATS
4230 &alloc_fastpath_attr
.attr
,
4231 &alloc_slowpath_attr
.attr
,
4232 &free_fastpath_attr
.attr
,
4233 &free_slowpath_attr
.attr
,
4234 &free_frozen_attr
.attr
,
4235 &free_add_partial_attr
.attr
,
4236 &free_remove_partial_attr
.attr
,
4237 &alloc_from_partial_attr
.attr
,
4238 &alloc_slab_attr
.attr
,
4239 &alloc_refill_attr
.attr
,
4240 &free_slab_attr
.attr
,
4241 &cpuslab_flush_attr
.attr
,
4242 &deactivate_full_attr
.attr
,
4243 &deactivate_empty_attr
.attr
,
4244 &deactivate_to_head_attr
.attr
,
4245 &deactivate_to_tail_attr
.attr
,
4246 &deactivate_remote_frees_attr
.attr
,
4247 &order_fallback_attr
.attr
,
4252 static struct attribute_group slab_attr_group
= {
4253 .attrs
= slab_attrs
,
4256 static ssize_t
slab_attr_show(struct kobject
*kobj
,
4257 struct attribute
*attr
,
4260 struct slab_attribute
*attribute
;
4261 struct kmem_cache
*s
;
4264 attribute
= to_slab_attr(attr
);
4267 if (!attribute
->show
)
4270 err
= attribute
->show(s
, buf
);
4275 static ssize_t
slab_attr_store(struct kobject
*kobj
,
4276 struct attribute
*attr
,
4277 const char *buf
, size_t len
)
4279 struct slab_attribute
*attribute
;
4280 struct kmem_cache
*s
;
4283 attribute
= to_slab_attr(attr
);
4286 if (!attribute
->store
)
4289 err
= attribute
->store(s
, buf
, len
);
4294 static void kmem_cache_release(struct kobject
*kobj
)
4296 struct kmem_cache
*s
= to_slab(kobj
);
4301 static struct sysfs_ops slab_sysfs_ops
= {
4302 .show
= slab_attr_show
,
4303 .store
= slab_attr_store
,
4306 static struct kobj_type slab_ktype
= {
4307 .sysfs_ops
= &slab_sysfs_ops
,
4308 .release
= kmem_cache_release
4311 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
4313 struct kobj_type
*ktype
= get_ktype(kobj
);
4315 if (ktype
== &slab_ktype
)
4320 static struct kset_uevent_ops slab_uevent_ops
= {
4321 .filter
= uevent_filter
,
4324 static struct kset
*slab_kset
;
4326 #define ID_STR_LENGTH 64
4328 /* Create a unique string id for a slab cache:
4330 * Format :[flags-]size
4332 static char *create_unique_id(struct kmem_cache
*s
)
4334 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
4341 * First flags affecting slabcache operations. We will only
4342 * get here for aliasable slabs so we do not need to support
4343 * too many flags. The flags here must cover all flags that
4344 * are matched during merging to guarantee that the id is
4347 if (s
->flags
& SLAB_CACHE_DMA
)
4349 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
4351 if (s
->flags
& SLAB_DEBUG_FREE
)
4355 p
+= sprintf(p
, "%07d", s
->size
);
4356 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
4360 static int sysfs_slab_add(struct kmem_cache
*s
)
4366 if (slab_state
< SYSFS
)
4367 /* Defer until later */
4370 unmergeable
= slab_unmergeable(s
);
4373 * Slabcache can never be merged so we can use the name proper.
4374 * This is typically the case for debug situations. In that
4375 * case we can catch duplicate names easily.
4377 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
4381 * Create a unique name for the slab as a target
4384 name
= create_unique_id(s
);
4387 s
->kobj
.kset
= slab_kset
;
4388 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, name
);
4390 kobject_put(&s
->kobj
);
4394 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
4397 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
4399 /* Setup first alias */
4400 sysfs_slab_alias(s
, s
->name
);
4406 static void sysfs_slab_remove(struct kmem_cache
*s
)
4408 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
4409 kobject_del(&s
->kobj
);
4410 kobject_put(&s
->kobj
);
4414 * Need to buffer aliases during bootup until sysfs becomes
4415 * available lest we loose that information.
4417 struct saved_alias
{
4418 struct kmem_cache
*s
;
4420 struct saved_alias
*next
;
4423 static struct saved_alias
*alias_list
;
4425 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
4427 struct saved_alias
*al
;
4429 if (slab_state
== SYSFS
) {
4431 * If we have a leftover link then remove it.
4433 sysfs_remove_link(&slab_kset
->kobj
, name
);
4434 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
4437 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
4443 al
->next
= alias_list
;
4448 static int __init
slab_sysfs_init(void)
4450 struct kmem_cache
*s
;
4453 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
4455 printk(KERN_ERR
"Cannot register slab subsystem.\n");
4461 list_for_each_entry(s
, &slab_caches
, list
) {
4462 err
= sysfs_slab_add(s
);
4464 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
4465 " to sysfs\n", s
->name
);
4468 while (alias_list
) {
4469 struct saved_alias
*al
= alias_list
;
4471 alias_list
= alias_list
->next
;
4472 err
= sysfs_slab_alias(al
->s
, al
->name
);
4474 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
4475 " %s to sysfs\n", s
->name
);
4483 __initcall(slab_sysfs_init
);
4487 * The /proc/slabinfo ABI
4489 #ifdef CONFIG_SLABINFO
4490 static void print_slabinfo_header(struct seq_file
*m
)
4492 seq_puts(m
, "slabinfo - version: 2.1\n");
4493 seq_puts(m
, "# name <active_objs> <num_objs> <objsize> "
4494 "<objperslab> <pagesperslab>");
4495 seq_puts(m
, " : tunables <limit> <batchcount> <sharedfactor>");
4496 seq_puts(m
, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4500 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
4504 down_read(&slub_lock
);
4506 print_slabinfo_header(m
);
4508 return seq_list_start(&slab_caches
, *pos
);
4511 static void *s_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4513 return seq_list_next(p
, &slab_caches
, pos
);
4516 static void s_stop(struct seq_file
*m
, void *p
)
4518 up_read(&slub_lock
);
4521 static int s_show(struct seq_file
*m
, void *p
)
4523 unsigned long nr_partials
= 0;
4524 unsigned long nr_slabs
= 0;
4525 unsigned long nr_inuse
= 0;
4526 unsigned long nr_objs
= 0;
4527 unsigned long nr_free
= 0;
4528 struct kmem_cache
*s
;
4531 s
= list_entry(p
, struct kmem_cache
, list
);
4533 for_each_online_node(node
) {
4534 struct kmem_cache_node
*n
= get_node(s
, node
);
4539 nr_partials
+= n
->nr_partial
;
4540 nr_slabs
+= atomic_long_read(&n
->nr_slabs
);
4541 nr_objs
+= atomic_long_read(&n
->total_objects
);
4542 nr_free
+= count_partial(n
, count_free
);
4545 nr_inuse
= nr_objs
- nr_free
;
4547 seq_printf(m
, "%-17s %6lu %6lu %6u %4u %4d", s
->name
, nr_inuse
,
4548 nr_objs
, s
->size
, oo_objects(s
->oo
),
4549 (1 << oo_order(s
->oo
)));
4550 seq_printf(m
, " : tunables %4u %4u %4u", 0, 0, 0);
4551 seq_printf(m
, " : slabdata %6lu %6lu %6lu", nr_slabs
, nr_slabs
,
4557 static const struct seq_operations slabinfo_op
= {
4564 static int slabinfo_open(struct inode
*inode
, struct file
*file
)
4566 return seq_open(file
, &slabinfo_op
);
4569 static const struct file_operations proc_slabinfo_operations
= {
4570 .open
= slabinfo_open
,
4572 .llseek
= seq_lseek
,
4573 .release
= seq_release
,
4576 static int __init
slab_proc_init(void)
4578 proc_create("slabinfo",S_IWUSR
|S_IRUGO
,NULL
,&proc_slabinfo_operations
);
4581 module_init(slab_proc_init
);
4582 #endif /* CONFIG_SLABINFO */