2 * SLUB: A slab allocator that limits cache line use instead of queuing
3 * objects in per cpu and per node lists.
5 * The allocator synchronizes using per slab locks or atomic operatios
6 * and only uses a centralized lock to manage a pool of partial slabs.
8 * (C) 2007 SGI, Christoph Lameter
9 * (C) 2011 Linux Foundation, Christoph Lameter
13 #include <linux/swap.h> /* struct reclaim_state */
14 #include <linux/module.h>
15 #include <linux/bit_spinlock.h>
16 #include <linux/interrupt.h>
17 #include <linux/bitops.h>
18 #include <linux/slab.h>
20 #include <linux/proc_fs.h>
21 #include <linux/seq_file.h>
22 #include <linux/kmemcheck.h>
23 #include <linux/cpu.h>
24 #include <linux/cpuset.h>
25 #include <linux/mempolicy.h>
26 #include <linux/ctype.h>
27 #include <linux/debugobjects.h>
28 #include <linux/kallsyms.h>
29 #include <linux/memory.h>
30 #include <linux/math64.h>
31 #include <linux/fault-inject.h>
32 #include <linux/stacktrace.h>
33 #include <linux/prefetch.h>
34 #include <linux/memcontrol.h>
36 #include <trace/events/kmem.h>
42 * 1. slab_mutex (Global Mutex)
44 * 3. slab_lock(page) (Only on some arches and for debugging)
48 * The role of the slab_mutex is to protect the list of all the slabs
49 * and to synchronize major metadata changes to slab cache structures.
51 * The slab_lock is only used for debugging and on arches that do not
52 * have the ability to do a cmpxchg_double. It only protects the second
53 * double word in the page struct. Meaning
54 * A. page->freelist -> List of object free in a page
55 * B. page->counters -> Counters of objects
56 * C. page->frozen -> frozen state
58 * If a slab is frozen then it is exempt from list management. It is not
59 * on any list. The processor that froze the slab is the one who can
60 * perform list operations on the page. Other processors may put objects
61 * onto the freelist but the processor that froze the slab is the only
62 * one that can retrieve the objects from the page's freelist.
64 * The list_lock protects the partial and full list on each node and
65 * the partial slab counter. If taken then no new slabs may be added or
66 * removed from the lists nor make the number of partial slabs be modified.
67 * (Note that the total number of slabs is an atomic value that may be
68 * modified without taking the list lock).
70 * The list_lock is a centralized lock and thus we avoid taking it as
71 * much as possible. As long as SLUB does not have to handle partial
72 * slabs, operations can continue without any centralized lock. F.e.
73 * allocating a long series of objects that fill up slabs does not require
75 * Interrupts are disabled during allocation and deallocation in order to
76 * make the slab allocator safe to use in the context of an irq. In addition
77 * interrupts are disabled to ensure that the processor does not change
78 * while handling per_cpu slabs, due to kernel preemption.
80 * SLUB assigns one slab for allocation to each processor.
81 * Allocations only occur from these slabs called cpu slabs.
83 * Slabs with free elements are kept on a partial list and during regular
84 * operations no list for full slabs is used. If an object in a full slab is
85 * freed then the slab will show up again on the partial lists.
86 * We track full slabs for debugging purposes though because otherwise we
87 * cannot scan all objects.
89 * Slabs are freed when they become empty. Teardown and setup is
90 * minimal so we rely on the page allocators per cpu caches for
91 * fast frees and allocs.
93 * Overloading of page flags that are otherwise used for LRU management.
95 * PageActive The slab is frozen and exempt from list processing.
96 * This means that the slab is dedicated to a purpose
97 * such as satisfying allocations for a specific
98 * processor. Objects may be freed in the slab while
99 * it is frozen but slab_free will then skip the usual
100 * list operations. It is up to the processor holding
101 * the slab to integrate the slab into the slab lists
102 * when the slab is no longer needed.
104 * One use of this flag is to mark slabs that are
105 * used for allocations. Then such a slab becomes a cpu
106 * slab. The cpu slab may be equipped with an additional
107 * freelist that allows lockless access to
108 * free objects in addition to the regular freelist
109 * that requires the slab lock.
111 * PageError Slab requires special handling due to debug
112 * options set. This moves slab handling out of
113 * the fast path and disables lockless freelists.
116 static inline int kmem_cache_debug(struct kmem_cache
*s
)
118 #ifdef CONFIG_SLUB_DEBUG
119 return unlikely(s
->flags
& SLAB_DEBUG_FLAGS
);
126 * Issues still to be resolved:
128 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
130 * - Variable sizing of the per node arrays
133 /* Enable to test recovery from slab corruption on boot */
134 #undef SLUB_RESILIENCY_TEST
136 /* Enable to log cmpxchg failures */
137 #undef SLUB_DEBUG_CMPXCHG
140 * Mininum number of partial slabs. These will be left on the partial
141 * lists even if they are empty. kmem_cache_shrink may reclaim them.
143 #define MIN_PARTIAL 5
146 * Maximum number of desirable partial slabs.
147 * The existence of more partial slabs makes kmem_cache_shrink
148 * sort the partial list by the number of objects in the.
150 #define MAX_PARTIAL 10
152 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
153 SLAB_POISON | SLAB_STORE_USER)
156 * Debugging flags that require metadata to be stored in the slab. These get
157 * disabled when slub_debug=O is used and a cache's min order increases with
160 #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
163 * Set of flags that will prevent slab merging
165 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
166 SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
169 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
170 SLAB_CACHE_DMA | SLAB_NOTRACK)
173 #define OO_MASK ((1 << OO_SHIFT) - 1)
174 #define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */
176 /* Internal SLUB flags */
177 #define __OBJECT_POISON 0x80000000UL /* Poison object */
178 #define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */
181 static struct notifier_block slab_notifier
;
185 * Tracking user of a slab.
187 #define TRACK_ADDRS_COUNT 16
189 unsigned long addr
; /* Called from address */
190 #ifdef CONFIG_STACKTRACE
191 unsigned long addrs
[TRACK_ADDRS_COUNT
]; /* Called from address */
193 int cpu
; /* Was running on cpu */
194 int pid
; /* Pid context */
195 unsigned long when
; /* When did the operation occur */
198 enum track_item
{ TRACK_ALLOC
, TRACK_FREE
};
201 static int sysfs_slab_add(struct kmem_cache
*);
202 static int sysfs_slab_alias(struct kmem_cache
*, const char *);
203 static void sysfs_slab_remove(struct kmem_cache
*);
206 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
207 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
209 static inline void sysfs_slab_remove(struct kmem_cache
*s
) { }
213 static inline void stat(const struct kmem_cache
*s
, enum stat_item si
)
215 #ifdef CONFIG_SLUB_STATS
216 __this_cpu_inc(s
->cpu_slab
->stat
[si
]);
220 /********************************************************************
221 * Core slab cache functions
222 *******************************************************************/
224 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
226 return s
->node
[node
];
229 /* Verify that a pointer has an address that is valid within a slab page */
230 static inline int check_valid_pointer(struct kmem_cache
*s
,
231 struct page
*page
, const void *object
)
238 base
= page_address(page
);
239 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
240 (object
- base
) % s
->size
) {
247 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
249 return *(void **)(object
+ s
->offset
);
252 static void prefetch_freepointer(const struct kmem_cache
*s
, void *object
)
254 prefetch(object
+ s
->offset
);
257 static inline void *get_freepointer_safe(struct kmem_cache
*s
, void *object
)
261 #ifdef CONFIG_DEBUG_PAGEALLOC
262 probe_kernel_read(&p
, (void **)(object
+ s
->offset
), sizeof(p
));
264 p
= get_freepointer(s
, object
);
269 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
271 *(void **)(object
+ s
->offset
) = fp
;
274 /* Loop over all objects in a slab */
275 #define for_each_object(__p, __s, __addr, __objects) \
276 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
279 /* Determine object index from a given position */
280 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
282 return (p
- addr
) / s
->size
;
285 static inline size_t slab_ksize(const struct kmem_cache
*s
)
287 #ifdef CONFIG_SLUB_DEBUG
289 * Debugging requires use of the padding between object
290 * and whatever may come after it.
292 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
293 return s
->object_size
;
297 * If we have the need to store the freelist pointer
298 * back there or track user information then we can
299 * only use the space before that information.
301 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
304 * Else we can use all the padding etc for the allocation
309 static inline int order_objects(int order
, unsigned long size
, int reserved
)
311 return ((PAGE_SIZE
<< order
) - reserved
) / size
;
314 static inline struct kmem_cache_order_objects
oo_make(int order
,
315 unsigned long size
, int reserved
)
317 struct kmem_cache_order_objects x
= {
318 (order
<< OO_SHIFT
) + order_objects(order
, size
, reserved
)
324 static inline int oo_order(struct kmem_cache_order_objects x
)
326 return x
.x
>> OO_SHIFT
;
329 static inline int oo_objects(struct kmem_cache_order_objects x
)
331 return x
.x
& OO_MASK
;
335 * Per slab locking using the pagelock
337 static __always_inline
void slab_lock(struct page
*page
)
339 bit_spin_lock(PG_locked
, &page
->flags
);
342 static __always_inline
void slab_unlock(struct page
*page
)
344 __bit_spin_unlock(PG_locked
, &page
->flags
);
347 /* Interrupts must be disabled (for the fallback code to work right) */
348 static inline bool __cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
349 void *freelist_old
, unsigned long counters_old
,
350 void *freelist_new
, unsigned long counters_new
,
353 VM_BUG_ON(!irqs_disabled());
354 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
355 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
356 if (s
->flags
& __CMPXCHG_DOUBLE
) {
357 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
358 freelist_old
, counters_old
,
359 freelist_new
, counters_new
))
365 if (page
->freelist
== freelist_old
&& page
->counters
== counters_old
) {
366 page
->freelist
= freelist_new
;
367 page
->counters
= counters_new
;
375 stat(s
, CMPXCHG_DOUBLE_FAIL
);
377 #ifdef SLUB_DEBUG_CMPXCHG
378 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
384 static inline bool cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
385 void *freelist_old
, unsigned long counters_old
,
386 void *freelist_new
, unsigned long counters_new
,
389 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
390 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
391 if (s
->flags
& __CMPXCHG_DOUBLE
) {
392 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
393 freelist_old
, counters_old
,
394 freelist_new
, counters_new
))
401 local_irq_save(flags
);
403 if (page
->freelist
== freelist_old
&& page
->counters
== counters_old
) {
404 page
->freelist
= freelist_new
;
405 page
->counters
= counters_new
;
407 local_irq_restore(flags
);
411 local_irq_restore(flags
);
415 stat(s
, CMPXCHG_DOUBLE_FAIL
);
417 #ifdef SLUB_DEBUG_CMPXCHG
418 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
424 #ifdef CONFIG_SLUB_DEBUG
426 * Determine a map of object in use on a page.
428 * Node listlock must be held to guarantee that the page does
429 * not vanish from under us.
431 static void get_map(struct kmem_cache
*s
, struct page
*page
, unsigned long *map
)
434 void *addr
= page_address(page
);
436 for (p
= page
->freelist
; p
; p
= get_freepointer(s
, p
))
437 set_bit(slab_index(p
, s
, addr
), map
);
443 #ifdef CONFIG_SLUB_DEBUG_ON
444 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
446 static int slub_debug
;
449 static char *slub_debug_slabs
;
450 static int disable_higher_order_debug
;
455 static void print_section(char *text
, u8
*addr
, unsigned int length
)
457 print_hex_dump(KERN_ERR
, text
, DUMP_PREFIX_ADDRESS
, 16, 1, addr
,
461 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
462 enum track_item alloc
)
467 p
= object
+ s
->offset
+ sizeof(void *);
469 p
= object
+ s
->inuse
;
474 static void set_track(struct kmem_cache
*s
, void *object
,
475 enum track_item alloc
, unsigned long addr
)
477 struct track
*p
= get_track(s
, object
, alloc
);
480 #ifdef CONFIG_STACKTRACE
481 struct stack_trace trace
;
484 trace
.nr_entries
= 0;
485 trace
.max_entries
= TRACK_ADDRS_COUNT
;
486 trace
.entries
= p
->addrs
;
488 save_stack_trace(&trace
);
490 /* See rant in lockdep.c */
491 if (trace
.nr_entries
!= 0 &&
492 trace
.entries
[trace
.nr_entries
- 1] == ULONG_MAX
)
495 for (i
= trace
.nr_entries
; i
< TRACK_ADDRS_COUNT
; i
++)
499 p
->cpu
= smp_processor_id();
500 p
->pid
= current
->pid
;
503 memset(p
, 0, sizeof(struct track
));
506 static void init_tracking(struct kmem_cache
*s
, void *object
)
508 if (!(s
->flags
& SLAB_STORE_USER
))
511 set_track(s
, object
, TRACK_FREE
, 0UL);
512 set_track(s
, object
, TRACK_ALLOC
, 0UL);
515 static void print_track(const char *s
, struct track
*t
)
520 printk(KERN_ERR
"INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
521 s
, (void *)t
->addr
, jiffies
- t
->when
, t
->cpu
, t
->pid
);
522 #ifdef CONFIG_STACKTRACE
525 for (i
= 0; i
< TRACK_ADDRS_COUNT
; i
++)
527 printk(KERN_ERR
"\t%pS\n", (void *)t
->addrs
[i
]);
534 static void print_tracking(struct kmem_cache
*s
, void *object
)
536 if (!(s
->flags
& SLAB_STORE_USER
))
539 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
540 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
543 static void print_page_info(struct page
*page
)
545 printk(KERN_ERR
"INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
546 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
550 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
556 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
558 printk(KERN_ERR
"========================================"
559 "=====================================\n");
560 printk(KERN_ERR
"BUG %s (%s): %s\n", s
->name
, print_tainted(), buf
);
561 printk(KERN_ERR
"----------------------------------------"
562 "-------------------------------------\n\n");
564 add_taint(TAINT_BAD_PAGE
);
567 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
573 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
575 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
578 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
580 unsigned int off
; /* Offset of last byte */
581 u8
*addr
= page_address(page
);
583 print_tracking(s
, p
);
585 print_page_info(page
);
587 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
588 p
, p
- addr
, get_freepointer(s
, p
));
591 print_section("Bytes b4 ", p
- 16, 16);
593 print_section("Object ", p
, min_t(unsigned long, s
->object_size
,
595 if (s
->flags
& SLAB_RED_ZONE
)
596 print_section("Redzone ", p
+ s
->object_size
,
597 s
->inuse
- s
->object_size
);
600 off
= s
->offset
+ sizeof(void *);
604 if (s
->flags
& SLAB_STORE_USER
)
605 off
+= 2 * sizeof(struct track
);
608 /* Beginning of the filler is the free pointer */
609 print_section("Padding ", p
+ off
, s
->size
- off
);
614 static void object_err(struct kmem_cache
*s
, struct page
*page
,
615 u8
*object
, char *reason
)
617 slab_bug(s
, "%s", reason
);
618 print_trailer(s
, page
, object
);
621 static void slab_err(struct kmem_cache
*s
, struct page
*page
, const char *fmt
, ...)
627 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
629 slab_bug(s
, "%s", buf
);
630 print_page_info(page
);
634 static void init_object(struct kmem_cache
*s
, void *object
, u8 val
)
638 if (s
->flags
& __OBJECT_POISON
) {
639 memset(p
, POISON_FREE
, s
->object_size
- 1);
640 p
[s
->object_size
- 1] = POISON_END
;
643 if (s
->flags
& SLAB_RED_ZONE
)
644 memset(p
+ s
->object_size
, val
, s
->inuse
- s
->object_size
);
647 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
648 void *from
, void *to
)
650 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
651 memset(from
, data
, to
- from
);
654 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
655 u8
*object
, char *what
,
656 u8
*start
, unsigned int value
, unsigned int bytes
)
661 fault
= memchr_inv(start
, value
, bytes
);
666 while (end
> fault
&& end
[-1] == value
)
669 slab_bug(s
, "%s overwritten", what
);
670 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
671 fault
, end
- 1, fault
[0], value
);
672 print_trailer(s
, page
, object
);
674 restore_bytes(s
, what
, value
, fault
, end
);
682 * Bytes of the object to be managed.
683 * If the freepointer may overlay the object then the free
684 * pointer is the first word of the object.
686 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
689 * object + s->object_size
690 * Padding to reach word boundary. This is also used for Redzoning.
691 * Padding is extended by another word if Redzoning is enabled and
692 * object_size == inuse.
694 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
695 * 0xcc (RED_ACTIVE) for objects in use.
698 * Meta data starts here.
700 * A. Free pointer (if we cannot overwrite object on free)
701 * B. Tracking data for SLAB_STORE_USER
702 * C. Padding to reach required alignment boundary or at mininum
703 * one word if debugging is on to be able to detect writes
704 * before the word boundary.
706 * Padding is done using 0x5a (POISON_INUSE)
709 * Nothing is used beyond s->size.
711 * If slabcaches are merged then the object_size and inuse boundaries are mostly
712 * ignored. And therefore no slab options that rely on these boundaries
713 * may be used with merged slabcaches.
716 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
718 unsigned long off
= s
->inuse
; /* The end of info */
721 /* Freepointer is placed after the object. */
722 off
+= sizeof(void *);
724 if (s
->flags
& SLAB_STORE_USER
)
725 /* We also have user information there */
726 off
+= 2 * sizeof(struct track
);
731 return check_bytes_and_report(s
, page
, p
, "Object padding",
732 p
+ off
, POISON_INUSE
, s
->size
- off
);
735 /* Check the pad bytes at the end of a slab page */
736 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
744 if (!(s
->flags
& SLAB_POISON
))
747 start
= page_address(page
);
748 length
= (PAGE_SIZE
<< compound_order(page
)) - s
->reserved
;
749 end
= start
+ length
;
750 remainder
= length
% s
->size
;
754 fault
= memchr_inv(end
- remainder
, POISON_INUSE
, remainder
);
757 while (end
> fault
&& end
[-1] == POISON_INUSE
)
760 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
761 print_section("Padding ", end
- remainder
, remainder
);
763 restore_bytes(s
, "slab padding", POISON_INUSE
, end
- remainder
, end
);
767 static int check_object(struct kmem_cache
*s
, struct page
*page
,
768 void *object
, u8 val
)
771 u8
*endobject
= object
+ s
->object_size
;
773 if (s
->flags
& SLAB_RED_ZONE
) {
774 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
775 endobject
, val
, s
->inuse
- s
->object_size
))
778 if ((s
->flags
& SLAB_POISON
) && s
->object_size
< s
->inuse
) {
779 check_bytes_and_report(s
, page
, p
, "Alignment padding",
780 endobject
, POISON_INUSE
, s
->inuse
- s
->object_size
);
784 if (s
->flags
& SLAB_POISON
) {
785 if (val
!= SLUB_RED_ACTIVE
&& (s
->flags
& __OBJECT_POISON
) &&
786 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
787 POISON_FREE
, s
->object_size
- 1) ||
788 !check_bytes_and_report(s
, page
, p
, "Poison",
789 p
+ s
->object_size
- 1, POISON_END
, 1)))
792 * check_pad_bytes cleans up on its own.
794 check_pad_bytes(s
, page
, p
);
797 if (!s
->offset
&& val
== SLUB_RED_ACTIVE
)
799 * Object and freepointer overlap. Cannot check
800 * freepointer while object is allocated.
804 /* Check free pointer validity */
805 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
806 object_err(s
, page
, p
, "Freepointer corrupt");
808 * No choice but to zap it and thus lose the remainder
809 * of the free objects in this slab. May cause
810 * another error because the object count is now wrong.
812 set_freepointer(s
, p
, NULL
);
818 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
822 VM_BUG_ON(!irqs_disabled());
824 if (!PageSlab(page
)) {
825 slab_err(s
, page
, "Not a valid slab page");
829 maxobj
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
830 if (page
->objects
> maxobj
) {
831 slab_err(s
, page
, "objects %u > max %u",
832 s
->name
, page
->objects
, maxobj
);
835 if (page
->inuse
> page
->objects
) {
836 slab_err(s
, page
, "inuse %u > max %u",
837 s
->name
, page
->inuse
, page
->objects
);
840 /* Slab_pad_check fixes things up after itself */
841 slab_pad_check(s
, page
);
846 * Determine if a certain object on a page is on the freelist. Must hold the
847 * slab lock to guarantee that the chains are in a consistent state.
849 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
854 unsigned long max_objects
;
857 while (fp
&& nr
<= page
->objects
) {
860 if (!check_valid_pointer(s
, page
, fp
)) {
862 object_err(s
, page
, object
,
863 "Freechain corrupt");
864 set_freepointer(s
, object
, NULL
);
867 slab_err(s
, page
, "Freepointer corrupt");
868 page
->freelist
= NULL
;
869 page
->inuse
= page
->objects
;
870 slab_fix(s
, "Freelist cleared");
876 fp
= get_freepointer(s
, object
);
880 max_objects
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
881 if (max_objects
> MAX_OBJS_PER_PAGE
)
882 max_objects
= MAX_OBJS_PER_PAGE
;
884 if (page
->objects
!= max_objects
) {
885 slab_err(s
, page
, "Wrong number of objects. Found %d but "
886 "should be %d", page
->objects
, max_objects
);
887 page
->objects
= max_objects
;
888 slab_fix(s
, "Number of objects adjusted.");
890 if (page
->inuse
!= page
->objects
- nr
) {
891 slab_err(s
, page
, "Wrong object count. Counter is %d but "
892 "counted were %d", page
->inuse
, page
->objects
- nr
);
893 page
->inuse
= page
->objects
- nr
;
894 slab_fix(s
, "Object count adjusted.");
896 return search
== NULL
;
899 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
,
902 if (s
->flags
& SLAB_TRACE
) {
903 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
905 alloc
? "alloc" : "free",
910 print_section("Object ", (void *)object
, s
->object_size
);
917 * Hooks for other subsystems that check memory allocations. In a typical
918 * production configuration these hooks all should produce no code at all.
920 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
922 flags
&= gfp_allowed_mask
;
923 lockdep_trace_alloc(flags
);
924 might_sleep_if(flags
& __GFP_WAIT
);
926 return should_failslab(s
->object_size
, flags
, s
->flags
);
929 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
, void *object
)
931 flags
&= gfp_allowed_mask
;
932 kmemcheck_slab_alloc(s
, flags
, object
, slab_ksize(s
));
933 kmemleak_alloc_recursive(object
, s
->object_size
, 1, s
->flags
, flags
);
936 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
)
938 kmemleak_free_recursive(x
, s
->flags
);
941 * Trouble is that we may no longer disable interupts in the fast path
942 * So in order to make the debug calls that expect irqs to be
943 * disabled we need to disable interrupts temporarily.
945 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
949 local_irq_save(flags
);
950 kmemcheck_slab_free(s
, x
, s
->object_size
);
951 debug_check_no_locks_freed(x
, s
->object_size
);
952 local_irq_restore(flags
);
955 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
956 debug_check_no_obj_freed(x
, s
->object_size
);
960 * Tracking of fully allocated slabs for debugging purposes.
962 * list_lock must be held.
964 static void add_full(struct kmem_cache
*s
,
965 struct kmem_cache_node
*n
, struct page
*page
)
967 if (!(s
->flags
& SLAB_STORE_USER
))
970 list_add(&page
->lru
, &n
->full
);
974 * list_lock must be held.
976 static void remove_full(struct kmem_cache
*s
, struct page
*page
)
978 if (!(s
->flags
& SLAB_STORE_USER
))
981 list_del(&page
->lru
);
984 /* Tracking of the number of slabs for debugging purposes */
985 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
987 struct kmem_cache_node
*n
= get_node(s
, node
);
989 return atomic_long_read(&n
->nr_slabs
);
992 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
994 return atomic_long_read(&n
->nr_slabs
);
997 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
999 struct kmem_cache_node
*n
= get_node(s
, node
);
1002 * May be called early in order to allocate a slab for the
1003 * kmem_cache_node structure. Solve the chicken-egg
1004 * dilemma by deferring the increment of the count during
1005 * bootstrap (see early_kmem_cache_node_alloc).
1008 atomic_long_inc(&n
->nr_slabs
);
1009 atomic_long_add(objects
, &n
->total_objects
);
1012 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1014 struct kmem_cache_node
*n
= get_node(s
, node
);
1016 atomic_long_dec(&n
->nr_slabs
);
1017 atomic_long_sub(objects
, &n
->total_objects
);
1020 /* Object debug checks for alloc/free paths */
1021 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
1024 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
1027 init_object(s
, object
, SLUB_RED_INACTIVE
);
1028 init_tracking(s
, object
);
1031 static noinline
int alloc_debug_processing(struct kmem_cache
*s
, struct page
*page
,
1032 void *object
, unsigned long addr
)
1034 if (!check_slab(s
, page
))
1037 if (!check_valid_pointer(s
, page
, object
)) {
1038 object_err(s
, page
, object
, "Freelist Pointer check fails");
1042 if (!check_object(s
, page
, object
, SLUB_RED_INACTIVE
))
1045 /* Success perform special debug activities for allocs */
1046 if (s
->flags
& SLAB_STORE_USER
)
1047 set_track(s
, object
, TRACK_ALLOC
, addr
);
1048 trace(s
, page
, object
, 1);
1049 init_object(s
, object
, SLUB_RED_ACTIVE
);
1053 if (PageSlab(page
)) {
1055 * If this is a slab page then lets do the best we can
1056 * to avoid issues in the future. Marking all objects
1057 * as used avoids touching the remaining objects.
1059 slab_fix(s
, "Marking all objects used");
1060 page
->inuse
= page
->objects
;
1061 page
->freelist
= NULL
;
1066 static noinline
struct kmem_cache_node
*free_debug_processing(
1067 struct kmem_cache
*s
, struct page
*page
, void *object
,
1068 unsigned long addr
, unsigned long *flags
)
1070 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1072 spin_lock_irqsave(&n
->list_lock
, *flags
);
1075 if (!check_slab(s
, page
))
1078 if (!check_valid_pointer(s
, page
, object
)) {
1079 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
1083 if (on_freelist(s
, page
, object
)) {
1084 object_err(s
, page
, object
, "Object already free");
1088 if (!check_object(s
, page
, object
, SLUB_RED_ACTIVE
))
1091 if (unlikely(s
!= page
->slab_cache
)) {
1092 if (!PageSlab(page
)) {
1093 slab_err(s
, page
, "Attempt to free object(0x%p) "
1094 "outside of slab", object
);
1095 } else if (!page
->slab_cache
) {
1097 "SLUB <none>: no slab for object 0x%p.\n",
1101 object_err(s
, page
, object
,
1102 "page slab pointer corrupt.");
1106 if (s
->flags
& SLAB_STORE_USER
)
1107 set_track(s
, object
, TRACK_FREE
, addr
);
1108 trace(s
, page
, object
, 0);
1109 init_object(s
, object
, SLUB_RED_INACTIVE
);
1113 * Keep node_lock to preserve integrity
1114 * until the object is actually freed
1120 spin_unlock_irqrestore(&n
->list_lock
, *flags
);
1121 slab_fix(s
, "Object at 0x%p not freed", object
);
1125 static int __init
setup_slub_debug(char *str
)
1127 slub_debug
= DEBUG_DEFAULT_FLAGS
;
1128 if (*str
++ != '=' || !*str
)
1130 * No options specified. Switch on full debugging.
1136 * No options but restriction on slabs. This means full
1137 * debugging for slabs matching a pattern.
1141 if (tolower(*str
) == 'o') {
1143 * Avoid enabling debugging on caches if its minimum order
1144 * would increase as a result.
1146 disable_higher_order_debug
= 1;
1153 * Switch off all debugging measures.
1158 * Determine which debug features should be switched on
1160 for (; *str
&& *str
!= ','; str
++) {
1161 switch (tolower(*str
)) {
1163 slub_debug
|= SLAB_DEBUG_FREE
;
1166 slub_debug
|= SLAB_RED_ZONE
;
1169 slub_debug
|= SLAB_POISON
;
1172 slub_debug
|= SLAB_STORE_USER
;
1175 slub_debug
|= SLAB_TRACE
;
1178 slub_debug
|= SLAB_FAILSLAB
;
1181 printk(KERN_ERR
"slub_debug option '%c' "
1182 "unknown. skipped\n", *str
);
1188 slub_debug_slabs
= str
+ 1;
1193 __setup("slub_debug", setup_slub_debug
);
1195 static unsigned long kmem_cache_flags(unsigned long object_size
,
1196 unsigned long flags
, const char *name
,
1197 void (*ctor
)(void *))
1200 * Enable debugging if selected on the kernel commandline.
1202 if (slub_debug
&& (!slub_debug_slabs
||
1203 !strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
))))
1204 flags
|= slub_debug
;
1209 static inline void setup_object_debug(struct kmem_cache
*s
,
1210 struct page
*page
, void *object
) {}
1212 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1213 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1215 static inline struct kmem_cache_node
*free_debug_processing(
1216 struct kmem_cache
*s
, struct page
*page
, void *object
,
1217 unsigned long addr
, unsigned long *flags
) { return NULL
; }
1219 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1221 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1222 void *object
, u8 val
) { return 1; }
1223 static inline void add_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1224 struct page
*page
) {}
1225 static inline void remove_full(struct kmem_cache
*s
, struct page
*page
) {}
1226 static inline unsigned long kmem_cache_flags(unsigned long object_size
,
1227 unsigned long flags
, const char *name
,
1228 void (*ctor
)(void *))
1232 #define slub_debug 0
1234 #define disable_higher_order_debug 0
1236 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1238 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1240 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1242 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1245 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
1248 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
,
1251 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
) {}
1253 #endif /* CONFIG_SLUB_DEBUG */
1256 * Slab allocation and freeing
1258 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1259 struct kmem_cache_order_objects oo
)
1261 int order
= oo_order(oo
);
1263 flags
|= __GFP_NOTRACK
;
1265 if (node
== NUMA_NO_NODE
)
1266 return alloc_pages(flags
, order
);
1268 return alloc_pages_exact_node(node
, flags
, order
);
1271 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1274 struct kmem_cache_order_objects oo
= s
->oo
;
1277 flags
&= gfp_allowed_mask
;
1279 if (flags
& __GFP_WAIT
)
1282 flags
|= s
->allocflags
;
1285 * Let the initial higher-order allocation fail under memory pressure
1286 * so we fall-back to the minimum order allocation.
1288 alloc_gfp
= (flags
| __GFP_NOWARN
| __GFP_NORETRY
) & ~__GFP_NOFAIL
;
1290 page
= alloc_slab_page(alloc_gfp
, node
, oo
);
1291 if (unlikely(!page
)) {
1294 * Allocation may have failed due to fragmentation.
1295 * Try a lower order alloc if possible
1297 page
= alloc_slab_page(flags
, node
, oo
);
1300 stat(s
, ORDER_FALLBACK
);
1303 if (kmemcheck_enabled
&& page
1304 && !(s
->flags
& (SLAB_NOTRACK
| DEBUG_DEFAULT_FLAGS
))) {
1305 int pages
= 1 << oo_order(oo
);
1307 kmemcheck_alloc_shadow(page
, oo_order(oo
), flags
, node
);
1310 * Objects from caches that have a constructor don't get
1311 * cleared when they're allocated, so we need to do it here.
1314 kmemcheck_mark_uninitialized_pages(page
, pages
);
1316 kmemcheck_mark_unallocated_pages(page
, pages
);
1319 if (flags
& __GFP_WAIT
)
1320 local_irq_disable();
1324 page
->objects
= oo_objects(oo
);
1325 mod_zone_page_state(page_zone(page
),
1326 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1327 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1333 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1336 setup_object_debug(s
, page
, object
);
1337 if (unlikely(s
->ctor
))
1341 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1348 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1350 page
= allocate_slab(s
,
1351 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1355 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1356 page
->slab_cache
= s
;
1357 __SetPageSlab(page
);
1358 if (page
->pfmemalloc
)
1359 SetPageSlabPfmemalloc(page
);
1361 start
= page_address(page
);
1363 if (unlikely(s
->flags
& SLAB_POISON
))
1364 memset(start
, POISON_INUSE
, PAGE_SIZE
<< compound_order(page
));
1367 for_each_object(p
, s
, start
, page
->objects
) {
1368 setup_object(s
, page
, last
);
1369 set_freepointer(s
, last
, p
);
1372 setup_object(s
, page
, last
);
1373 set_freepointer(s
, last
, NULL
);
1375 page
->freelist
= start
;
1376 page
->inuse
= page
->objects
;
1382 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1384 int order
= compound_order(page
);
1385 int pages
= 1 << order
;
1387 if (kmem_cache_debug(s
)) {
1390 slab_pad_check(s
, page
);
1391 for_each_object(p
, s
, page_address(page
),
1393 check_object(s
, page
, p
, SLUB_RED_INACTIVE
);
1396 kmemcheck_free_shadow(page
, compound_order(page
));
1398 mod_zone_page_state(page_zone(page
),
1399 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1400 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1403 __ClearPageSlabPfmemalloc(page
);
1404 __ClearPageSlab(page
);
1405 reset_page_mapcount(page
);
1406 if (current
->reclaim_state
)
1407 current
->reclaim_state
->reclaimed_slab
+= pages
;
1408 __free_pages(page
, order
);
1411 #define need_reserve_slab_rcu \
1412 (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
1414 static void rcu_free_slab(struct rcu_head
*h
)
1418 if (need_reserve_slab_rcu
)
1419 page
= virt_to_head_page(h
);
1421 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1423 __free_slab(page
->slab_cache
, page
);
1426 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1428 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1429 struct rcu_head
*head
;
1431 if (need_reserve_slab_rcu
) {
1432 int order
= compound_order(page
);
1433 int offset
= (PAGE_SIZE
<< order
) - s
->reserved
;
1435 VM_BUG_ON(s
->reserved
!= sizeof(*head
));
1436 head
= page_address(page
) + offset
;
1439 * RCU free overloads the RCU head over the LRU
1441 head
= (void *)&page
->lru
;
1444 call_rcu(head
, rcu_free_slab
);
1446 __free_slab(s
, page
);
1449 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1451 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1456 * Management of partially allocated slabs.
1458 * list_lock must be held.
1460 static inline void add_partial(struct kmem_cache_node
*n
,
1461 struct page
*page
, int tail
)
1464 if (tail
== DEACTIVATE_TO_TAIL
)
1465 list_add_tail(&page
->lru
, &n
->partial
);
1467 list_add(&page
->lru
, &n
->partial
);
1471 * list_lock must be held.
1473 static inline void remove_partial(struct kmem_cache_node
*n
,
1476 list_del(&page
->lru
);
1481 * Remove slab from the partial list, freeze it and
1482 * return the pointer to the freelist.
1484 * Returns a list of objects or NULL if it fails.
1486 * Must hold list_lock since we modify the partial list.
1488 static inline void *acquire_slab(struct kmem_cache
*s
,
1489 struct kmem_cache_node
*n
, struct page
*page
,
1493 unsigned long counters
;
1497 * Zap the freelist and set the frozen bit.
1498 * The old freelist is the list of objects for the
1499 * per cpu allocation list.
1501 freelist
= page
->freelist
;
1502 counters
= page
->counters
;
1503 new.counters
= counters
;
1505 new.inuse
= page
->objects
;
1506 new.freelist
= NULL
;
1508 new.freelist
= freelist
;
1511 VM_BUG_ON(new.frozen
);
1514 if (!__cmpxchg_double_slab(s
, page
,
1516 new.freelist
, new.counters
,
1520 remove_partial(n
, page
);
1525 static int put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
);
1526 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
);
1529 * Try to allocate a partial slab from a specific node.
1531 static void *get_partial_node(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1532 struct kmem_cache_cpu
*c
, gfp_t flags
)
1534 struct page
*page
, *page2
;
1535 void *object
= NULL
;
1538 * Racy check. If we mistakenly see no partial slabs then we
1539 * just allocate an empty slab. If we mistakenly try to get a
1540 * partial slab and there is none available then get_partials()
1543 if (!n
|| !n
->nr_partial
)
1546 spin_lock(&n
->list_lock
);
1547 list_for_each_entry_safe(page
, page2
, &n
->partial
, lru
) {
1551 if (!pfmemalloc_match(page
, flags
))
1554 t
= acquire_slab(s
, n
, page
, object
== NULL
);
1560 stat(s
, ALLOC_FROM_PARTIAL
);
1562 available
= page
->objects
- page
->inuse
;
1564 available
= put_cpu_partial(s
, page
, 0);
1565 stat(s
, CPU_PARTIAL_NODE
);
1567 if (kmem_cache_debug(s
) || available
> s
->cpu_partial
/ 2)
1571 spin_unlock(&n
->list_lock
);
1576 * Get a page from somewhere. Search in increasing NUMA distances.
1578 static void *get_any_partial(struct kmem_cache
*s
, gfp_t flags
,
1579 struct kmem_cache_cpu
*c
)
1582 struct zonelist
*zonelist
;
1585 enum zone_type high_zoneidx
= gfp_zone(flags
);
1587 unsigned int cpuset_mems_cookie
;
1590 * The defrag ratio allows a configuration of the tradeoffs between
1591 * inter node defragmentation and node local allocations. A lower
1592 * defrag_ratio increases the tendency to do local allocations
1593 * instead of attempting to obtain partial slabs from other nodes.
1595 * If the defrag_ratio is set to 0 then kmalloc() always
1596 * returns node local objects. If the ratio is higher then kmalloc()
1597 * may return off node objects because partial slabs are obtained
1598 * from other nodes and filled up.
1600 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1601 * defrag_ratio = 1000) then every (well almost) allocation will
1602 * first attempt to defrag slab caches on other nodes. This means
1603 * scanning over all nodes to look for partial slabs which may be
1604 * expensive if we do it every time we are trying to find a slab
1605 * with available objects.
1607 if (!s
->remote_node_defrag_ratio
||
1608 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1612 cpuset_mems_cookie
= get_mems_allowed();
1613 zonelist
= node_zonelist(slab_node(), flags
);
1614 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
1615 struct kmem_cache_node
*n
;
1617 n
= get_node(s
, zone_to_nid(zone
));
1619 if (n
&& cpuset_zone_allowed_hardwall(zone
, flags
) &&
1620 n
->nr_partial
> s
->min_partial
) {
1621 object
= get_partial_node(s
, n
, c
, flags
);
1624 * Return the object even if
1625 * put_mems_allowed indicated that
1626 * the cpuset mems_allowed was
1627 * updated in parallel. It's a
1628 * harmless race between the alloc
1629 * and the cpuset update.
1631 put_mems_allowed(cpuset_mems_cookie
);
1636 } while (!put_mems_allowed(cpuset_mems_cookie
));
1642 * Get a partial page, lock it and return it.
1644 static void *get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
,
1645 struct kmem_cache_cpu
*c
)
1648 int searchnode
= (node
== NUMA_NO_NODE
) ? numa_node_id() : node
;
1650 object
= get_partial_node(s
, get_node(s
, searchnode
), c
, flags
);
1651 if (object
|| node
!= NUMA_NO_NODE
)
1654 return get_any_partial(s
, flags
, c
);
1657 #ifdef CONFIG_PREEMPT
1659 * Calculate the next globally unique transaction for disambiguiation
1660 * during cmpxchg. The transactions start with the cpu number and are then
1661 * incremented by CONFIG_NR_CPUS.
1663 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1666 * No preemption supported therefore also no need to check for
1672 static inline unsigned long next_tid(unsigned long tid
)
1674 return tid
+ TID_STEP
;
1677 static inline unsigned int tid_to_cpu(unsigned long tid
)
1679 return tid
% TID_STEP
;
1682 static inline unsigned long tid_to_event(unsigned long tid
)
1684 return tid
/ TID_STEP
;
1687 static inline unsigned int init_tid(int cpu
)
1692 static inline void note_cmpxchg_failure(const char *n
,
1693 const struct kmem_cache
*s
, unsigned long tid
)
1695 #ifdef SLUB_DEBUG_CMPXCHG
1696 unsigned long actual_tid
= __this_cpu_read(s
->cpu_slab
->tid
);
1698 printk(KERN_INFO
"%s %s: cmpxchg redo ", n
, s
->name
);
1700 #ifdef CONFIG_PREEMPT
1701 if (tid_to_cpu(tid
) != tid_to_cpu(actual_tid
))
1702 printk("due to cpu change %d -> %d\n",
1703 tid_to_cpu(tid
), tid_to_cpu(actual_tid
));
1706 if (tid_to_event(tid
) != tid_to_event(actual_tid
))
1707 printk("due to cpu running other code. Event %ld->%ld\n",
1708 tid_to_event(tid
), tid_to_event(actual_tid
));
1710 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1711 actual_tid
, tid
, next_tid(tid
));
1713 stat(s
, CMPXCHG_DOUBLE_CPU_FAIL
);
1716 static void init_kmem_cache_cpus(struct kmem_cache
*s
)
1720 for_each_possible_cpu(cpu
)
1721 per_cpu_ptr(s
->cpu_slab
, cpu
)->tid
= init_tid(cpu
);
1725 * Remove the cpu slab
1727 static void deactivate_slab(struct kmem_cache
*s
, struct page
*page
, void *freelist
)
1729 enum slab_modes
{ M_NONE
, M_PARTIAL
, M_FULL
, M_FREE
};
1730 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1732 enum slab_modes l
= M_NONE
, m
= M_NONE
;
1734 int tail
= DEACTIVATE_TO_HEAD
;
1738 if (page
->freelist
) {
1739 stat(s
, DEACTIVATE_REMOTE_FREES
);
1740 tail
= DEACTIVATE_TO_TAIL
;
1744 * Stage one: Free all available per cpu objects back
1745 * to the page freelist while it is still frozen. Leave the
1748 * There is no need to take the list->lock because the page
1751 while (freelist
&& (nextfree
= get_freepointer(s
, freelist
))) {
1753 unsigned long counters
;
1756 prior
= page
->freelist
;
1757 counters
= page
->counters
;
1758 set_freepointer(s
, freelist
, prior
);
1759 new.counters
= counters
;
1761 VM_BUG_ON(!new.frozen
);
1763 } while (!__cmpxchg_double_slab(s
, page
,
1765 freelist
, new.counters
,
1766 "drain percpu freelist"));
1768 freelist
= nextfree
;
1772 * Stage two: Ensure that the page is unfrozen while the
1773 * list presence reflects the actual number of objects
1776 * We setup the list membership and then perform a cmpxchg
1777 * with the count. If there is a mismatch then the page
1778 * is not unfrozen but the page is on the wrong list.
1780 * Then we restart the process which may have to remove
1781 * the page from the list that we just put it on again
1782 * because the number of objects in the slab may have
1787 old
.freelist
= page
->freelist
;
1788 old
.counters
= page
->counters
;
1789 VM_BUG_ON(!old
.frozen
);
1791 /* Determine target state of the slab */
1792 new.counters
= old
.counters
;
1795 set_freepointer(s
, freelist
, old
.freelist
);
1796 new.freelist
= freelist
;
1798 new.freelist
= old
.freelist
;
1802 if (!new.inuse
&& n
->nr_partial
> s
->min_partial
)
1804 else if (new.freelist
) {
1809 * Taking the spinlock removes the possiblity
1810 * that acquire_slab() will see a slab page that
1813 spin_lock(&n
->list_lock
);
1817 if (kmem_cache_debug(s
) && !lock
) {
1820 * This also ensures that the scanning of full
1821 * slabs from diagnostic functions will not see
1824 spin_lock(&n
->list_lock
);
1832 remove_partial(n
, page
);
1834 else if (l
== M_FULL
)
1836 remove_full(s
, page
);
1838 if (m
== M_PARTIAL
) {
1840 add_partial(n
, page
, tail
);
1843 } else if (m
== M_FULL
) {
1845 stat(s
, DEACTIVATE_FULL
);
1846 add_full(s
, n
, page
);
1852 if (!__cmpxchg_double_slab(s
, page
,
1853 old
.freelist
, old
.counters
,
1854 new.freelist
, new.counters
,
1859 spin_unlock(&n
->list_lock
);
1862 stat(s
, DEACTIVATE_EMPTY
);
1863 discard_slab(s
, page
);
1869 * Unfreeze all the cpu partial slabs.
1871 * This function must be called with interrupts disabled
1872 * for the cpu using c (or some other guarantee must be there
1873 * to guarantee no concurrent accesses).
1875 static void unfreeze_partials(struct kmem_cache
*s
,
1876 struct kmem_cache_cpu
*c
)
1878 struct kmem_cache_node
*n
= NULL
, *n2
= NULL
;
1879 struct page
*page
, *discard_page
= NULL
;
1881 while ((page
= c
->partial
)) {
1885 c
->partial
= page
->next
;
1887 n2
= get_node(s
, page_to_nid(page
));
1890 spin_unlock(&n
->list_lock
);
1893 spin_lock(&n
->list_lock
);
1898 old
.freelist
= page
->freelist
;
1899 old
.counters
= page
->counters
;
1900 VM_BUG_ON(!old
.frozen
);
1902 new.counters
= old
.counters
;
1903 new.freelist
= old
.freelist
;
1907 } while (!__cmpxchg_double_slab(s
, page
,
1908 old
.freelist
, old
.counters
,
1909 new.freelist
, new.counters
,
1910 "unfreezing slab"));
1912 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
)) {
1913 page
->next
= discard_page
;
1914 discard_page
= page
;
1916 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
1917 stat(s
, FREE_ADD_PARTIAL
);
1922 spin_unlock(&n
->list_lock
);
1924 while (discard_page
) {
1925 page
= discard_page
;
1926 discard_page
= discard_page
->next
;
1928 stat(s
, DEACTIVATE_EMPTY
);
1929 discard_slab(s
, page
);
1935 * Put a page that was just frozen (in __slab_free) into a partial page
1936 * slot if available. This is done without interrupts disabled and without
1937 * preemption disabled. The cmpxchg is racy and may put the partial page
1938 * onto a random cpus partial slot.
1940 * If we did not find a slot then simply move all the partials to the
1941 * per node partial list.
1943 static int put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
)
1945 struct page
*oldpage
;
1952 oldpage
= this_cpu_read(s
->cpu_slab
->partial
);
1955 pobjects
= oldpage
->pobjects
;
1956 pages
= oldpage
->pages
;
1957 if (drain
&& pobjects
> s
->cpu_partial
) {
1958 unsigned long flags
;
1960 * partial array is full. Move the existing
1961 * set to the per node partial list.
1963 local_irq_save(flags
);
1964 unfreeze_partials(s
, this_cpu_ptr(s
->cpu_slab
));
1965 local_irq_restore(flags
);
1969 stat(s
, CPU_PARTIAL_DRAIN
);
1974 pobjects
+= page
->objects
- page
->inuse
;
1976 page
->pages
= pages
;
1977 page
->pobjects
= pobjects
;
1978 page
->next
= oldpage
;
1980 } while (this_cpu_cmpxchg(s
->cpu_slab
->partial
, oldpage
, page
) != oldpage
);
1984 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
1986 stat(s
, CPUSLAB_FLUSH
);
1987 deactivate_slab(s
, c
->page
, c
->freelist
);
1989 c
->tid
= next_tid(c
->tid
);
1997 * Called from IPI handler with interrupts disabled.
1999 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
2001 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2007 unfreeze_partials(s
, c
);
2011 static void flush_cpu_slab(void *d
)
2013 struct kmem_cache
*s
= d
;
2015 __flush_cpu_slab(s
, smp_processor_id());
2018 static bool has_cpu_slab(int cpu
, void *info
)
2020 struct kmem_cache
*s
= info
;
2021 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2023 return c
->page
|| c
->partial
;
2026 static void flush_all(struct kmem_cache
*s
)
2028 on_each_cpu_cond(has_cpu_slab
, flush_cpu_slab
, s
, 1, GFP_ATOMIC
);
2032 * Check if the objects in a per cpu structure fit numa
2033 * locality expectations.
2035 static inline int node_match(struct page
*page
, int node
)
2038 if (node
!= NUMA_NO_NODE
&& page_to_nid(page
) != node
)
2044 static int count_free(struct page
*page
)
2046 return page
->objects
- page
->inuse
;
2049 static unsigned long count_partial(struct kmem_cache_node
*n
,
2050 int (*get_count
)(struct page
*))
2052 unsigned long flags
;
2053 unsigned long x
= 0;
2056 spin_lock_irqsave(&n
->list_lock
, flags
);
2057 list_for_each_entry(page
, &n
->partial
, lru
)
2058 x
+= get_count(page
);
2059 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2063 static inline unsigned long node_nr_objs(struct kmem_cache_node
*n
)
2065 #ifdef CONFIG_SLUB_DEBUG
2066 return atomic_long_read(&n
->total_objects
);
2072 static noinline
void
2073 slab_out_of_memory(struct kmem_cache
*s
, gfp_t gfpflags
, int nid
)
2078 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
2080 printk(KERN_WARNING
" cache: %s, object size: %d, buffer size: %d, "
2081 "default order: %d, min order: %d\n", s
->name
, s
->object_size
,
2082 s
->size
, oo_order(s
->oo
), oo_order(s
->min
));
2084 if (oo_order(s
->min
) > get_order(s
->object_size
))
2085 printk(KERN_WARNING
" %s debugging increased min order, use "
2086 "slub_debug=O to disable.\n", s
->name
);
2088 for_each_online_node(node
) {
2089 struct kmem_cache_node
*n
= get_node(s
, node
);
2090 unsigned long nr_slabs
;
2091 unsigned long nr_objs
;
2092 unsigned long nr_free
;
2097 nr_free
= count_partial(n
, count_free
);
2098 nr_slabs
= node_nr_slabs(n
);
2099 nr_objs
= node_nr_objs(n
);
2102 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
2103 node
, nr_slabs
, nr_objs
, nr_free
);
2107 static inline void *new_slab_objects(struct kmem_cache
*s
, gfp_t flags
,
2108 int node
, struct kmem_cache_cpu
**pc
)
2111 struct kmem_cache_cpu
*c
= *pc
;
2114 freelist
= get_partial(s
, flags
, node
, c
);
2119 page
= new_slab(s
, flags
, node
);
2121 c
= __this_cpu_ptr(s
->cpu_slab
);
2126 * No other reference to the page yet so we can
2127 * muck around with it freely without cmpxchg
2129 freelist
= page
->freelist
;
2130 page
->freelist
= NULL
;
2132 stat(s
, ALLOC_SLAB
);
2141 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
)
2143 if (unlikely(PageSlabPfmemalloc(page
)))
2144 return gfp_pfmemalloc_allowed(gfpflags
);
2150 * Check the page->freelist of a page and either transfer the freelist to the per cpu freelist
2151 * or deactivate the page.
2153 * The page is still frozen if the return value is not NULL.
2155 * If this function returns NULL then the page has been unfrozen.
2157 * This function must be called with interrupt disabled.
2159 static inline void *get_freelist(struct kmem_cache
*s
, struct page
*page
)
2162 unsigned long counters
;
2166 freelist
= page
->freelist
;
2167 counters
= page
->counters
;
2169 new.counters
= counters
;
2170 VM_BUG_ON(!new.frozen
);
2172 new.inuse
= page
->objects
;
2173 new.frozen
= freelist
!= NULL
;
2175 } while (!__cmpxchg_double_slab(s
, page
,
2184 * Slow path. The lockless freelist is empty or we need to perform
2187 * Processing is still very fast if new objects have been freed to the
2188 * regular freelist. In that case we simply take over the regular freelist
2189 * as the lockless freelist and zap the regular freelist.
2191 * If that is not working then we fall back to the partial lists. We take the
2192 * first element of the freelist as the object to allocate now and move the
2193 * rest of the freelist to the lockless freelist.
2195 * And if we were unable to get a new slab from the partial slab lists then
2196 * we need to allocate a new slab. This is the slowest path since it involves
2197 * a call to the page allocator and the setup of a new slab.
2199 static void *__slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, int node
,
2200 unsigned long addr
, struct kmem_cache_cpu
*c
)
2204 unsigned long flags
;
2206 local_irq_save(flags
);
2207 #ifdef CONFIG_PREEMPT
2209 * We may have been preempted and rescheduled on a different
2210 * cpu before disabling interrupts. Need to reload cpu area
2213 c
= this_cpu_ptr(s
->cpu_slab
);
2221 if (unlikely(!node_match(page
, node
))) {
2222 stat(s
, ALLOC_NODE_MISMATCH
);
2223 deactivate_slab(s
, page
, c
->freelist
);
2230 * By rights, we should be searching for a slab page that was
2231 * PFMEMALLOC but right now, we are losing the pfmemalloc
2232 * information when the page leaves the per-cpu allocator
2234 if (unlikely(!pfmemalloc_match(page
, gfpflags
))) {
2235 deactivate_slab(s
, page
, c
->freelist
);
2241 /* must check again c->freelist in case of cpu migration or IRQ */
2242 freelist
= c
->freelist
;
2246 stat(s
, ALLOC_SLOWPATH
);
2248 freelist
= get_freelist(s
, page
);
2252 stat(s
, DEACTIVATE_BYPASS
);
2256 stat(s
, ALLOC_REFILL
);
2260 * freelist is pointing to the list of objects to be used.
2261 * page is pointing to the page from which the objects are obtained.
2262 * That page must be frozen for per cpu allocations to work.
2264 VM_BUG_ON(!c
->page
->frozen
);
2265 c
->freelist
= get_freepointer(s
, freelist
);
2266 c
->tid
= next_tid(c
->tid
);
2267 local_irq_restore(flags
);
2273 page
= c
->page
= c
->partial
;
2274 c
->partial
= page
->next
;
2275 stat(s
, CPU_PARTIAL_ALLOC
);
2280 freelist
= new_slab_objects(s
, gfpflags
, node
, &c
);
2282 if (unlikely(!freelist
)) {
2283 if (!(gfpflags
& __GFP_NOWARN
) && printk_ratelimit())
2284 slab_out_of_memory(s
, gfpflags
, node
);
2286 local_irq_restore(flags
);
2291 if (likely(!kmem_cache_debug(s
) && pfmemalloc_match(page
, gfpflags
)))
2294 /* Only entered in the debug case */
2295 if (kmem_cache_debug(s
) && !alloc_debug_processing(s
, page
, freelist
, addr
))
2296 goto new_slab
; /* Slab failed checks. Next slab needed */
2298 deactivate_slab(s
, page
, get_freepointer(s
, freelist
));
2301 local_irq_restore(flags
);
2306 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
2307 * have the fastpath folded into their functions. So no function call
2308 * overhead for requests that can be satisfied on the fastpath.
2310 * The fastpath works by first checking if the lockless freelist can be used.
2311 * If not then __slab_alloc is called for slow processing.
2313 * Otherwise we can simply pick the next object from the lockless free list.
2315 static __always_inline
void *slab_alloc_node(struct kmem_cache
*s
,
2316 gfp_t gfpflags
, int node
, unsigned long addr
)
2319 struct kmem_cache_cpu
*c
;
2323 if (slab_pre_alloc_hook(s
, gfpflags
))
2329 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
2330 * enabled. We may switch back and forth between cpus while
2331 * reading from one cpu area. That does not matter as long
2332 * as we end up on the original cpu again when doing the cmpxchg.
2334 c
= __this_cpu_ptr(s
->cpu_slab
);
2337 * The transaction ids are globally unique per cpu and per operation on
2338 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
2339 * occurs on the right processor and that there was no operation on the
2340 * linked list in between.
2345 object
= c
->freelist
;
2347 if (unlikely(!object
|| !node_match(page
, node
)))
2348 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
2351 void *next_object
= get_freepointer_safe(s
, object
);
2354 * The cmpxchg will only match if there was no additional
2355 * operation and if we are on the right processor.
2357 * The cmpxchg does the following atomically (without lock semantics!)
2358 * 1. Relocate first pointer to the current per cpu area.
2359 * 2. Verify that tid and freelist have not been changed
2360 * 3. If they were not changed replace tid and freelist
2362 * Since this is without lock semantics the protection is only against
2363 * code executing on this cpu *not* from access by other cpus.
2365 if (unlikely(!this_cpu_cmpxchg_double(
2366 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2368 next_object
, next_tid(tid
)))) {
2370 note_cmpxchg_failure("slab_alloc", s
, tid
);
2373 prefetch_freepointer(s
, next_object
);
2374 stat(s
, ALLOC_FASTPATH
);
2377 if (unlikely(gfpflags
& __GFP_ZERO
) && object
)
2378 memset(object
, 0, s
->object_size
);
2380 slab_post_alloc_hook(s
, gfpflags
, object
);
2385 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
2386 gfp_t gfpflags
, unsigned long addr
)
2388 return slab_alloc_node(s
, gfpflags
, NUMA_NO_NODE
, addr
);
2391 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
2393 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2395 trace_kmem_cache_alloc(_RET_IP_
, ret
, s
->object_size
, s
->size
, gfpflags
);
2399 EXPORT_SYMBOL(kmem_cache_alloc
);
2401 #ifdef CONFIG_TRACING
2402 void *kmem_cache_alloc_trace(struct kmem_cache
*s
, gfp_t gfpflags
, size_t size
)
2404 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2405 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, gfpflags
);
2408 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
2410 void *kmalloc_order_trace(size_t size
, gfp_t flags
, unsigned int order
)
2412 void *ret
= kmalloc_order(size
, flags
, order
);
2413 trace_kmalloc(_RET_IP_
, ret
, size
, PAGE_SIZE
<< order
, flags
);
2416 EXPORT_SYMBOL(kmalloc_order_trace
);
2420 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
2422 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2424 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
2425 s
->object_size
, s
->size
, gfpflags
, node
);
2429 EXPORT_SYMBOL(kmem_cache_alloc_node
);
2431 #ifdef CONFIG_TRACING
2432 void *kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
2434 int node
, size_t size
)
2436 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2438 trace_kmalloc_node(_RET_IP_
, ret
,
2439 size
, s
->size
, gfpflags
, node
);
2442 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
2447 * Slow patch handling. This may still be called frequently since objects
2448 * have a longer lifetime than the cpu slabs in most processing loads.
2450 * So we still attempt to reduce cache line usage. Just take the slab
2451 * lock and free the item. If there is no additional partial page
2452 * handling required then we can return immediately.
2454 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
2455 void *x
, unsigned long addr
)
2458 void **object
= (void *)x
;
2461 unsigned long counters
;
2462 struct kmem_cache_node
*n
= NULL
;
2463 unsigned long uninitialized_var(flags
);
2465 stat(s
, FREE_SLOWPATH
);
2467 if (kmem_cache_debug(s
) &&
2468 !(n
= free_debug_processing(s
, page
, x
, addr
, &flags
)))
2473 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2476 prior
= page
->freelist
;
2477 counters
= page
->counters
;
2478 set_freepointer(s
, object
, prior
);
2479 new.counters
= counters
;
2480 was_frozen
= new.frozen
;
2482 if ((!new.inuse
|| !prior
) && !was_frozen
) {
2484 if (!kmem_cache_debug(s
) && !prior
)
2487 * Slab was on no list before and will be partially empty
2488 * We can defer the list move and instead freeze it.
2492 else { /* Needs to be taken off a list */
2494 n
= get_node(s
, page_to_nid(page
));
2496 * Speculatively acquire the list_lock.
2497 * If the cmpxchg does not succeed then we may
2498 * drop the list_lock without any processing.
2500 * Otherwise the list_lock will synchronize with
2501 * other processors updating the list of slabs.
2503 spin_lock_irqsave(&n
->list_lock
, flags
);
2508 } while (!cmpxchg_double_slab(s
, page
,
2510 object
, new.counters
,
2516 * If we just froze the page then put it onto the
2517 * per cpu partial list.
2519 if (new.frozen
&& !was_frozen
) {
2520 put_cpu_partial(s
, page
, 1);
2521 stat(s
, CPU_PARTIAL_FREE
);
2524 * The list lock was not taken therefore no list
2525 * activity can be necessary.
2528 stat(s
, FREE_FROZEN
);
2532 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
))
2536 * Objects left in the slab. If it was not on the partial list before
2539 if (kmem_cache_debug(s
) && unlikely(!prior
)) {
2540 remove_full(s
, page
);
2541 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
2542 stat(s
, FREE_ADD_PARTIAL
);
2544 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2550 * Slab on the partial list.
2552 remove_partial(n
, page
);
2553 stat(s
, FREE_REMOVE_PARTIAL
);
2555 /* Slab must be on the full list */
2556 remove_full(s
, page
);
2558 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2560 discard_slab(s
, page
);
2564 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2565 * can perform fastpath freeing without additional function calls.
2567 * The fastpath is only possible if we are freeing to the current cpu slab
2568 * of this processor. This typically the case if we have just allocated
2571 * If fastpath is not possible then fall back to __slab_free where we deal
2572 * with all sorts of special processing.
2574 static __always_inline
void slab_free(struct kmem_cache
*s
,
2575 struct page
*page
, void *x
, unsigned long addr
)
2577 void **object
= (void *)x
;
2578 struct kmem_cache_cpu
*c
;
2581 slab_free_hook(s
, x
);
2585 * Determine the currently cpus per cpu slab.
2586 * The cpu may change afterward. However that does not matter since
2587 * data is retrieved via this pointer. If we are on the same cpu
2588 * during the cmpxchg then the free will succedd.
2590 c
= __this_cpu_ptr(s
->cpu_slab
);
2595 if (likely(page
== c
->page
)) {
2596 set_freepointer(s
, object
, c
->freelist
);
2598 if (unlikely(!this_cpu_cmpxchg_double(
2599 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2601 object
, next_tid(tid
)))) {
2603 note_cmpxchg_failure("slab_free", s
, tid
);
2606 stat(s
, FREE_FASTPATH
);
2608 __slab_free(s
, page
, x
, addr
);
2612 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
2614 s
= cache_from_obj(s
, x
);
2617 slab_free(s
, virt_to_head_page(x
), x
, _RET_IP_
);
2618 trace_kmem_cache_free(_RET_IP_
, x
);
2620 EXPORT_SYMBOL(kmem_cache_free
);
2623 * Object placement in a slab is made very easy because we always start at
2624 * offset 0. If we tune the size of the object to the alignment then we can
2625 * get the required alignment by putting one properly sized object after
2628 * Notice that the allocation order determines the sizes of the per cpu
2629 * caches. Each processor has always one slab available for allocations.
2630 * Increasing the allocation order reduces the number of times that slabs
2631 * must be moved on and off the partial lists and is therefore a factor in
2636 * Mininum / Maximum order of slab pages. This influences locking overhead
2637 * and slab fragmentation. A higher order reduces the number of partial slabs
2638 * and increases the number of allocations possible without having to
2639 * take the list_lock.
2641 static int slub_min_order
;
2642 static int slub_max_order
= PAGE_ALLOC_COSTLY_ORDER
;
2643 static int slub_min_objects
;
2646 * Merge control. If this is set then no merging of slab caches will occur.
2647 * (Could be removed. This was introduced to pacify the merge skeptics.)
2649 static int slub_nomerge
;
2652 * Calculate the order of allocation given an slab object size.
2654 * The order of allocation has significant impact on performance and other
2655 * system components. Generally order 0 allocations should be preferred since
2656 * order 0 does not cause fragmentation in the page allocator. Larger objects
2657 * be problematic to put into order 0 slabs because there may be too much
2658 * unused space left. We go to a higher order if more than 1/16th of the slab
2661 * In order to reach satisfactory performance we must ensure that a minimum
2662 * number of objects is in one slab. Otherwise we may generate too much
2663 * activity on the partial lists which requires taking the list_lock. This is
2664 * less a concern for large slabs though which are rarely used.
2666 * slub_max_order specifies the order where we begin to stop considering the
2667 * number of objects in a slab as critical. If we reach slub_max_order then
2668 * we try to keep the page order as low as possible. So we accept more waste
2669 * of space in favor of a small page order.
2671 * Higher order allocations also allow the placement of more objects in a
2672 * slab and thereby reduce object handling overhead. If the user has
2673 * requested a higher mininum order then we start with that one instead of
2674 * the smallest order which will fit the object.
2676 static inline int slab_order(int size
, int min_objects
,
2677 int max_order
, int fract_leftover
, int reserved
)
2681 int min_order
= slub_min_order
;
2683 if (order_objects(min_order
, size
, reserved
) > MAX_OBJS_PER_PAGE
)
2684 return get_order(size
* MAX_OBJS_PER_PAGE
) - 1;
2686 for (order
= max(min_order
,
2687 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
2688 order
<= max_order
; order
++) {
2690 unsigned long slab_size
= PAGE_SIZE
<< order
;
2692 if (slab_size
< min_objects
* size
+ reserved
)
2695 rem
= (slab_size
- reserved
) % size
;
2697 if (rem
<= slab_size
/ fract_leftover
)
2705 static inline int calculate_order(int size
, int reserved
)
2713 * Attempt to find best configuration for a slab. This
2714 * works by first attempting to generate a layout with
2715 * the best configuration and backing off gradually.
2717 * First we reduce the acceptable waste in a slab. Then
2718 * we reduce the minimum objects required in a slab.
2720 min_objects
= slub_min_objects
;
2722 min_objects
= 4 * (fls(nr_cpu_ids
) + 1);
2723 max_objects
= order_objects(slub_max_order
, size
, reserved
);
2724 min_objects
= min(min_objects
, max_objects
);
2726 while (min_objects
> 1) {
2728 while (fraction
>= 4) {
2729 order
= slab_order(size
, min_objects
,
2730 slub_max_order
, fraction
, reserved
);
2731 if (order
<= slub_max_order
)
2739 * We were unable to place multiple objects in a slab. Now
2740 * lets see if we can place a single object there.
2742 order
= slab_order(size
, 1, slub_max_order
, 1, reserved
);
2743 if (order
<= slub_max_order
)
2747 * Doh this slab cannot be placed using slub_max_order.
2749 order
= slab_order(size
, 1, MAX_ORDER
, 1, reserved
);
2750 if (order
< MAX_ORDER
)
2756 init_kmem_cache_node(struct kmem_cache_node
*n
)
2759 spin_lock_init(&n
->list_lock
);
2760 INIT_LIST_HEAD(&n
->partial
);
2761 #ifdef CONFIG_SLUB_DEBUG
2762 atomic_long_set(&n
->nr_slabs
, 0);
2763 atomic_long_set(&n
->total_objects
, 0);
2764 INIT_LIST_HEAD(&n
->full
);
2768 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
)
2770 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE
<
2771 SLUB_PAGE_SHIFT
* sizeof(struct kmem_cache_cpu
));
2774 * Must align to double word boundary for the double cmpxchg
2775 * instructions to work; see __pcpu_double_call_return_bool().
2777 s
->cpu_slab
= __alloc_percpu(sizeof(struct kmem_cache_cpu
),
2778 2 * sizeof(void *));
2783 init_kmem_cache_cpus(s
);
2788 static struct kmem_cache
*kmem_cache_node
;
2791 * No kmalloc_node yet so do it by hand. We know that this is the first
2792 * slab on the node for this slabcache. There are no concurrent accesses
2795 * Note that this function only works on the kmalloc_node_cache
2796 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2797 * memory on a fresh node that has no slab structures yet.
2799 static void early_kmem_cache_node_alloc(int node
)
2802 struct kmem_cache_node
*n
;
2804 BUG_ON(kmem_cache_node
->size
< sizeof(struct kmem_cache_node
));
2806 page
= new_slab(kmem_cache_node
, GFP_NOWAIT
, node
);
2809 if (page_to_nid(page
) != node
) {
2810 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2812 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2813 "in order to be able to continue\n");
2818 page
->freelist
= get_freepointer(kmem_cache_node
, n
);
2821 kmem_cache_node
->node
[node
] = n
;
2822 #ifdef CONFIG_SLUB_DEBUG
2823 init_object(kmem_cache_node
, n
, SLUB_RED_ACTIVE
);
2824 init_tracking(kmem_cache_node
, n
);
2826 init_kmem_cache_node(n
);
2827 inc_slabs_node(kmem_cache_node
, node
, page
->objects
);
2829 add_partial(n
, page
, DEACTIVATE_TO_HEAD
);
2832 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2836 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2837 struct kmem_cache_node
*n
= s
->node
[node
];
2840 kmem_cache_free(kmem_cache_node
, n
);
2842 s
->node
[node
] = NULL
;
2846 static int init_kmem_cache_nodes(struct kmem_cache
*s
)
2850 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2851 struct kmem_cache_node
*n
;
2853 if (slab_state
== DOWN
) {
2854 early_kmem_cache_node_alloc(node
);
2857 n
= kmem_cache_alloc_node(kmem_cache_node
,
2861 free_kmem_cache_nodes(s
);
2866 init_kmem_cache_node(n
);
2871 static void set_min_partial(struct kmem_cache
*s
, unsigned long min
)
2873 if (min
< MIN_PARTIAL
)
2875 else if (min
> MAX_PARTIAL
)
2877 s
->min_partial
= min
;
2881 * calculate_sizes() determines the order and the distribution of data within
2884 static int calculate_sizes(struct kmem_cache
*s
, int forced_order
)
2886 unsigned long flags
= s
->flags
;
2887 unsigned long size
= s
->object_size
;
2891 * Round up object size to the next word boundary. We can only
2892 * place the free pointer at word boundaries and this determines
2893 * the possible location of the free pointer.
2895 size
= ALIGN(size
, sizeof(void *));
2897 #ifdef CONFIG_SLUB_DEBUG
2899 * Determine if we can poison the object itself. If the user of
2900 * the slab may touch the object after free or before allocation
2901 * then we should never poison the object itself.
2903 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2905 s
->flags
|= __OBJECT_POISON
;
2907 s
->flags
&= ~__OBJECT_POISON
;
2911 * If we are Redzoning then check if there is some space between the
2912 * end of the object and the free pointer. If not then add an
2913 * additional word to have some bytes to store Redzone information.
2915 if ((flags
& SLAB_RED_ZONE
) && size
== s
->object_size
)
2916 size
+= sizeof(void *);
2920 * With that we have determined the number of bytes in actual use
2921 * by the object. This is the potential offset to the free pointer.
2925 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
2928 * Relocate free pointer after the object if it is not
2929 * permitted to overwrite the first word of the object on
2932 * This is the case if we do RCU, have a constructor or
2933 * destructor or are poisoning the objects.
2936 size
+= sizeof(void *);
2939 #ifdef CONFIG_SLUB_DEBUG
2940 if (flags
& SLAB_STORE_USER
)
2942 * Need to store information about allocs and frees after
2945 size
+= 2 * sizeof(struct track
);
2947 if (flags
& SLAB_RED_ZONE
)
2949 * Add some empty padding so that we can catch
2950 * overwrites from earlier objects rather than let
2951 * tracking information or the free pointer be
2952 * corrupted if a user writes before the start
2955 size
+= sizeof(void *);
2959 * SLUB stores one object immediately after another beginning from
2960 * offset 0. In order to align the objects we have to simply size
2961 * each object to conform to the alignment.
2963 size
= ALIGN(size
, s
->align
);
2965 if (forced_order
>= 0)
2966 order
= forced_order
;
2968 order
= calculate_order(size
, s
->reserved
);
2975 s
->allocflags
|= __GFP_COMP
;
2977 if (s
->flags
& SLAB_CACHE_DMA
)
2978 s
->allocflags
|= SLUB_DMA
;
2980 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
2981 s
->allocflags
|= __GFP_RECLAIMABLE
;
2984 * Determine the number of objects per slab
2986 s
->oo
= oo_make(order
, size
, s
->reserved
);
2987 s
->min
= oo_make(get_order(size
), size
, s
->reserved
);
2988 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
2991 return !!oo_objects(s
->oo
);
2994 static int kmem_cache_open(struct kmem_cache
*s
, unsigned long flags
)
2996 s
->flags
= kmem_cache_flags(s
->size
, flags
, s
->name
, s
->ctor
);
2999 if (need_reserve_slab_rcu
&& (s
->flags
& SLAB_DESTROY_BY_RCU
))
3000 s
->reserved
= sizeof(struct rcu_head
);
3002 if (!calculate_sizes(s
, -1))
3004 if (disable_higher_order_debug
) {
3006 * Disable debugging flags that store metadata if the min slab
3009 if (get_order(s
->size
) > get_order(s
->object_size
)) {
3010 s
->flags
&= ~DEBUG_METADATA_FLAGS
;
3012 if (!calculate_sizes(s
, -1))
3017 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
3018 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
3019 if (system_has_cmpxchg_double() && (s
->flags
& SLAB_DEBUG_FLAGS
) == 0)
3020 /* Enable fast mode */
3021 s
->flags
|= __CMPXCHG_DOUBLE
;
3025 * The larger the object size is, the more pages we want on the partial
3026 * list to avoid pounding the page allocator excessively.
3028 set_min_partial(s
, ilog2(s
->size
) / 2);
3031 * cpu_partial determined the maximum number of objects kept in the
3032 * per cpu partial lists of a processor.
3034 * Per cpu partial lists mainly contain slabs that just have one
3035 * object freed. If they are used for allocation then they can be
3036 * filled up again with minimal effort. The slab will never hit the
3037 * per node partial lists and therefore no locking will be required.
3039 * This setting also determines
3041 * A) The number of objects from per cpu partial slabs dumped to the
3042 * per node list when we reach the limit.
3043 * B) The number of objects in cpu partial slabs to extract from the
3044 * per node list when we run out of per cpu objects. We only fetch 50%
3045 * to keep some capacity around for frees.
3047 if (kmem_cache_debug(s
))
3049 else if (s
->size
>= PAGE_SIZE
)
3051 else if (s
->size
>= 1024)
3053 else if (s
->size
>= 256)
3054 s
->cpu_partial
= 13;
3056 s
->cpu_partial
= 30;
3059 s
->remote_node_defrag_ratio
= 1000;
3061 if (!init_kmem_cache_nodes(s
))
3064 if (alloc_kmem_cache_cpus(s
))
3067 free_kmem_cache_nodes(s
);
3069 if (flags
& SLAB_PANIC
)
3070 panic("Cannot create slab %s size=%lu realsize=%u "
3071 "order=%u offset=%u flags=%lx\n",
3072 s
->name
, (unsigned long)s
->size
, s
->size
, oo_order(s
->oo
),
3077 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
3080 #ifdef CONFIG_SLUB_DEBUG
3081 void *addr
= page_address(page
);
3083 unsigned long *map
= kzalloc(BITS_TO_LONGS(page
->objects
) *
3084 sizeof(long), GFP_ATOMIC
);
3087 slab_err(s
, page
, text
, s
->name
);
3090 get_map(s
, page
, map
);
3091 for_each_object(p
, s
, addr
, page
->objects
) {
3093 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
3094 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
3096 print_tracking(s
, p
);
3105 * Attempt to free all partial slabs on a node.
3106 * This is called from kmem_cache_close(). We must be the last thread
3107 * using the cache and therefore we do not need to lock anymore.
3109 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
3111 struct page
*page
, *h
;
3113 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
3115 remove_partial(n
, page
);
3116 discard_slab(s
, page
);
3118 list_slab_objects(s
, page
,
3119 "Objects remaining in %s on kmem_cache_close()");
3125 * Release all resources used by a slab cache.
3127 static inline int kmem_cache_close(struct kmem_cache
*s
)
3132 /* Attempt to free all objects */
3133 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3134 struct kmem_cache_node
*n
= get_node(s
, node
);
3137 if (n
->nr_partial
|| slabs_node(s
, node
))
3140 free_percpu(s
->cpu_slab
);
3141 free_kmem_cache_nodes(s
);
3145 int __kmem_cache_shutdown(struct kmem_cache
*s
)
3147 int rc
= kmem_cache_close(s
);
3150 sysfs_slab_remove(s
);
3155 /********************************************************************
3157 *******************************************************************/
3159 struct kmem_cache
*kmalloc_caches
[SLUB_PAGE_SHIFT
];
3160 EXPORT_SYMBOL(kmalloc_caches
);
3162 #ifdef CONFIG_ZONE_DMA
3163 static struct kmem_cache
*kmalloc_dma_caches
[SLUB_PAGE_SHIFT
];
3166 static int __init
setup_slub_min_order(char *str
)
3168 get_option(&str
, &slub_min_order
);
3173 __setup("slub_min_order=", setup_slub_min_order
);
3175 static int __init
setup_slub_max_order(char *str
)
3177 get_option(&str
, &slub_max_order
);
3178 slub_max_order
= min(slub_max_order
, MAX_ORDER
- 1);
3183 __setup("slub_max_order=", setup_slub_max_order
);
3185 static int __init
setup_slub_min_objects(char *str
)
3187 get_option(&str
, &slub_min_objects
);
3192 __setup("slub_min_objects=", setup_slub_min_objects
);
3194 static int __init
setup_slub_nomerge(char *str
)
3200 __setup("slub_nomerge", setup_slub_nomerge
);
3203 * Conversion table for small slabs sizes / 8 to the index in the
3204 * kmalloc array. This is necessary for slabs < 192 since we have non power
3205 * of two cache sizes there. The size of larger slabs can be determined using
3208 static s8 size_index
[24] = {
3235 static inline int size_index_elem(size_t bytes
)
3237 return (bytes
- 1) / 8;
3240 static struct kmem_cache
*get_slab(size_t size
, gfp_t flags
)
3246 return ZERO_SIZE_PTR
;
3248 index
= size_index
[size_index_elem(size
)];
3250 index
= fls(size
- 1);
3252 #ifdef CONFIG_ZONE_DMA
3253 if (unlikely((flags
& SLUB_DMA
)))
3254 return kmalloc_dma_caches
[index
];
3257 return kmalloc_caches
[index
];
3260 void *__kmalloc(size_t size
, gfp_t flags
)
3262 struct kmem_cache
*s
;
3265 if (unlikely(size
> SLUB_MAX_SIZE
))
3266 return kmalloc_large(size
, flags
);
3268 s
= get_slab(size
, flags
);
3270 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3273 ret
= slab_alloc(s
, flags
, _RET_IP_
);
3275 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, flags
);
3279 EXPORT_SYMBOL(__kmalloc
);
3282 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
3287 flags
|= __GFP_COMP
| __GFP_NOTRACK
;
3288 page
= alloc_pages_node(node
, flags
, get_order(size
));
3290 ptr
= page_address(page
);
3292 kmemleak_alloc(ptr
, size
, 1, flags
);
3296 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3298 struct kmem_cache
*s
;
3301 if (unlikely(size
> SLUB_MAX_SIZE
)) {
3302 ret
= kmalloc_large_node(size
, flags
, node
);
3304 trace_kmalloc_node(_RET_IP_
, ret
,
3305 size
, PAGE_SIZE
<< get_order(size
),
3311 s
= get_slab(size
, flags
);
3313 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3316 ret
= slab_alloc_node(s
, flags
, node
, _RET_IP_
);
3318 trace_kmalloc_node(_RET_IP_
, ret
, size
, s
->size
, flags
, node
);
3322 EXPORT_SYMBOL(__kmalloc_node
);
3325 size_t ksize(const void *object
)
3329 if (unlikely(object
== ZERO_SIZE_PTR
))
3332 page
= virt_to_head_page(object
);
3334 if (unlikely(!PageSlab(page
))) {
3335 WARN_ON(!PageCompound(page
));
3336 return PAGE_SIZE
<< compound_order(page
);
3339 return slab_ksize(page
->slab_cache
);
3341 EXPORT_SYMBOL(ksize
);
3343 #ifdef CONFIG_SLUB_DEBUG
3344 bool verify_mem_not_deleted(const void *x
)
3347 void *object
= (void *)x
;
3348 unsigned long flags
;
3351 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3354 local_irq_save(flags
);
3356 page
= virt_to_head_page(x
);
3357 if (unlikely(!PageSlab(page
))) {
3358 /* maybe it was from stack? */
3364 if (on_freelist(page
->slab_cache
, page
, object
)) {
3365 object_err(page
->slab_cache
, page
, object
, "Object is on free-list");
3373 local_irq_restore(flags
);
3376 EXPORT_SYMBOL(verify_mem_not_deleted
);
3379 void kfree(const void *x
)
3382 void *object
= (void *)x
;
3384 trace_kfree(_RET_IP_
, x
);
3386 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3389 page
= virt_to_head_page(x
);
3390 if (unlikely(!PageSlab(page
))) {
3391 BUG_ON(!PageCompound(page
));
3393 __free_pages(page
, compound_order(page
));
3396 slab_free(page
->slab_cache
, page
, object
, _RET_IP_
);
3398 EXPORT_SYMBOL(kfree
);
3401 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
3402 * the remaining slabs by the number of items in use. The slabs with the
3403 * most items in use come first. New allocations will then fill those up
3404 * and thus they can be removed from the partial lists.
3406 * The slabs with the least items are placed last. This results in them
3407 * being allocated from last increasing the chance that the last objects
3408 * are freed in them.
3410 int kmem_cache_shrink(struct kmem_cache
*s
)
3414 struct kmem_cache_node
*n
;
3417 int objects
= oo_objects(s
->max
);
3418 struct list_head
*slabs_by_inuse
=
3419 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
3420 unsigned long flags
;
3422 if (!slabs_by_inuse
)
3426 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3427 n
= get_node(s
, node
);
3432 for (i
= 0; i
< objects
; i
++)
3433 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
3435 spin_lock_irqsave(&n
->list_lock
, flags
);
3438 * Build lists indexed by the items in use in each slab.
3440 * Note that concurrent frees may occur while we hold the
3441 * list_lock. page->inuse here is the upper limit.
3443 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
3444 list_move(&page
->lru
, slabs_by_inuse
+ page
->inuse
);
3450 * Rebuild the partial list with the slabs filled up most
3451 * first and the least used slabs at the end.
3453 for (i
= objects
- 1; i
> 0; i
--)
3454 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
3456 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3458 /* Release empty slabs */
3459 list_for_each_entry_safe(page
, t
, slabs_by_inuse
, lru
)
3460 discard_slab(s
, page
);
3463 kfree(slabs_by_inuse
);
3466 EXPORT_SYMBOL(kmem_cache_shrink
);
3468 #if defined(CONFIG_MEMORY_HOTPLUG)
3469 static int slab_mem_going_offline_callback(void *arg
)
3471 struct kmem_cache
*s
;
3473 mutex_lock(&slab_mutex
);
3474 list_for_each_entry(s
, &slab_caches
, list
)
3475 kmem_cache_shrink(s
);
3476 mutex_unlock(&slab_mutex
);
3481 static void slab_mem_offline_callback(void *arg
)
3483 struct kmem_cache_node
*n
;
3484 struct kmem_cache
*s
;
3485 struct memory_notify
*marg
= arg
;
3488 offline_node
= marg
->status_change_nid_normal
;
3491 * If the node still has available memory. we need kmem_cache_node
3494 if (offline_node
< 0)
3497 mutex_lock(&slab_mutex
);
3498 list_for_each_entry(s
, &slab_caches
, list
) {
3499 n
= get_node(s
, offline_node
);
3502 * if n->nr_slabs > 0, slabs still exist on the node
3503 * that is going down. We were unable to free them,
3504 * and offline_pages() function shouldn't call this
3505 * callback. So, we must fail.
3507 BUG_ON(slabs_node(s
, offline_node
));
3509 s
->node
[offline_node
] = NULL
;
3510 kmem_cache_free(kmem_cache_node
, n
);
3513 mutex_unlock(&slab_mutex
);
3516 static int slab_mem_going_online_callback(void *arg
)
3518 struct kmem_cache_node
*n
;
3519 struct kmem_cache
*s
;
3520 struct memory_notify
*marg
= arg
;
3521 int nid
= marg
->status_change_nid_normal
;
3525 * If the node's memory is already available, then kmem_cache_node is
3526 * already created. Nothing to do.
3532 * We are bringing a node online. No memory is available yet. We must
3533 * allocate a kmem_cache_node structure in order to bring the node
3536 mutex_lock(&slab_mutex
);
3537 list_for_each_entry(s
, &slab_caches
, list
) {
3539 * XXX: kmem_cache_alloc_node will fallback to other nodes
3540 * since memory is not yet available from the node that
3543 n
= kmem_cache_alloc(kmem_cache_node
, GFP_KERNEL
);
3548 init_kmem_cache_node(n
);
3552 mutex_unlock(&slab_mutex
);
3556 static int slab_memory_callback(struct notifier_block
*self
,
3557 unsigned long action
, void *arg
)
3562 case MEM_GOING_ONLINE
:
3563 ret
= slab_mem_going_online_callback(arg
);
3565 case MEM_GOING_OFFLINE
:
3566 ret
= slab_mem_going_offline_callback(arg
);
3569 case MEM_CANCEL_ONLINE
:
3570 slab_mem_offline_callback(arg
);
3573 case MEM_CANCEL_OFFLINE
:
3577 ret
= notifier_from_errno(ret
);
3583 #endif /* CONFIG_MEMORY_HOTPLUG */
3585 /********************************************************************
3586 * Basic setup of slabs
3587 *******************************************************************/
3590 * Used for early kmem_cache structures that were allocated using
3591 * the page allocator. Allocate them properly then fix up the pointers
3592 * that may be pointing to the wrong kmem_cache structure.
3595 static struct kmem_cache
* __init
bootstrap(struct kmem_cache
*static_cache
)
3598 struct kmem_cache
*s
= kmem_cache_zalloc(kmem_cache
, GFP_NOWAIT
);
3600 memcpy(s
, static_cache
, kmem_cache
->object_size
);
3602 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3603 struct kmem_cache_node
*n
= get_node(s
, node
);
3607 list_for_each_entry(p
, &n
->partial
, lru
)
3610 #ifdef CONFIG_SLUB_DEBUG
3611 list_for_each_entry(p
, &n
->full
, lru
)
3616 list_add(&s
->list
, &slab_caches
);
3620 void __init
kmem_cache_init(void)
3622 static __initdata
struct kmem_cache boot_kmem_cache
,
3623 boot_kmem_cache_node
;
3627 if (debug_guardpage_minorder())
3630 kmem_cache_node
= &boot_kmem_cache_node
;
3631 kmem_cache
= &boot_kmem_cache
;
3633 create_boot_cache(kmem_cache_node
, "kmem_cache_node",
3634 sizeof(struct kmem_cache_node
), SLAB_HWCACHE_ALIGN
);
3636 hotplug_memory_notifier(slab_memory_callback
, SLAB_CALLBACK_PRI
);
3638 /* Able to allocate the per node structures */
3639 slab_state
= PARTIAL
;
3641 create_boot_cache(kmem_cache
, "kmem_cache",
3642 offsetof(struct kmem_cache
, node
) +
3643 nr_node_ids
* sizeof(struct kmem_cache_node
*),
3644 SLAB_HWCACHE_ALIGN
);
3646 kmem_cache
= bootstrap(&boot_kmem_cache
);
3649 * Allocate kmem_cache_node properly from the kmem_cache slab.
3650 * kmem_cache_node is separately allocated so no need to
3651 * update any list pointers.
3653 kmem_cache_node
= bootstrap(&boot_kmem_cache_node
);
3655 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3658 * Patch up the size_index table if we have strange large alignment
3659 * requirements for the kmalloc array. This is only the case for
3660 * MIPS it seems. The standard arches will not generate any code here.
3662 * Largest permitted alignment is 256 bytes due to the way we
3663 * handle the index determination for the smaller caches.
3665 * Make sure that nothing crazy happens if someone starts tinkering
3666 * around with ARCH_KMALLOC_MINALIGN
3668 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 256 ||
3669 (KMALLOC_MIN_SIZE
& (KMALLOC_MIN_SIZE
- 1)));
3671 for (i
= 8; i
< KMALLOC_MIN_SIZE
; i
+= 8) {
3672 int elem
= size_index_elem(i
);
3673 if (elem
>= ARRAY_SIZE(size_index
))
3675 size_index
[elem
] = KMALLOC_SHIFT_LOW
;
3678 if (KMALLOC_MIN_SIZE
== 64) {
3680 * The 96 byte size cache is not used if the alignment
3683 for (i
= 64 + 8; i
<= 96; i
+= 8)
3684 size_index
[size_index_elem(i
)] = 7;
3685 } else if (KMALLOC_MIN_SIZE
== 128) {
3687 * The 192 byte sized cache is not used if the alignment
3688 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3691 for (i
= 128 + 8; i
<= 192; i
+= 8)
3692 size_index
[size_index_elem(i
)] = 8;
3695 /* Caches that are not of the two-to-the-power-of size */
3696 if (KMALLOC_MIN_SIZE
<= 32) {
3697 kmalloc_caches
[1] = create_kmalloc_cache("kmalloc-96", 96, 0);
3701 if (KMALLOC_MIN_SIZE
<= 64) {
3702 kmalloc_caches
[2] = create_kmalloc_cache("kmalloc-192", 192, 0);
3706 for (i
= KMALLOC_SHIFT_LOW
; i
< SLUB_PAGE_SHIFT
; i
++) {
3707 kmalloc_caches
[i
] = create_kmalloc_cache("kmalloc", 1 << i
, 0);
3713 /* Provide the correct kmalloc names now that the caches are up */
3714 if (KMALLOC_MIN_SIZE
<= 32) {
3715 kmalloc_caches
[1]->name
= kstrdup(kmalloc_caches
[1]->name
, GFP_NOWAIT
);
3716 BUG_ON(!kmalloc_caches
[1]->name
);
3719 if (KMALLOC_MIN_SIZE
<= 64) {
3720 kmalloc_caches
[2]->name
= kstrdup(kmalloc_caches
[2]->name
, GFP_NOWAIT
);
3721 BUG_ON(!kmalloc_caches
[2]->name
);
3724 for (i
= KMALLOC_SHIFT_LOW
; i
< SLUB_PAGE_SHIFT
; i
++) {
3725 char *s
= kasprintf(GFP_NOWAIT
, "kmalloc-%d", 1 << i
);
3728 kmalloc_caches
[i
]->name
= s
;
3732 register_cpu_notifier(&slab_notifier
);
3735 #ifdef CONFIG_ZONE_DMA
3736 for (i
= 0; i
< SLUB_PAGE_SHIFT
; i
++) {
3737 struct kmem_cache
*s
= kmalloc_caches
[i
];
3740 char *name
= kasprintf(GFP_NOWAIT
,
3741 "dma-kmalloc-%d", s
->object_size
);
3744 kmalloc_dma_caches
[i
] = create_kmalloc_cache(name
,
3745 s
->object_size
, SLAB_CACHE_DMA
);
3750 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3751 " CPUs=%d, Nodes=%d\n",
3752 caches
, cache_line_size(),
3753 slub_min_order
, slub_max_order
, slub_min_objects
,
3754 nr_cpu_ids
, nr_node_ids
);
3757 void __init
kmem_cache_init_late(void)
3762 * Find a mergeable slab cache
3764 static int slab_unmergeable(struct kmem_cache
*s
)
3766 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3773 * We may have set a slab to be unmergeable during bootstrap.
3775 if (s
->refcount
< 0)
3781 static struct kmem_cache
*find_mergeable(struct mem_cgroup
*memcg
, size_t size
,
3782 size_t align
, unsigned long flags
, const char *name
,
3783 void (*ctor
)(void *))
3785 struct kmem_cache
*s
;
3787 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3793 size
= ALIGN(size
, sizeof(void *));
3794 align
= calculate_alignment(flags
, align
, size
);
3795 size
= ALIGN(size
, align
);
3796 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3798 list_for_each_entry(s
, &slab_caches
, list
) {
3799 if (slab_unmergeable(s
))
3805 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3808 * Check if alignment is compatible.
3809 * Courtesy of Adrian Drzewiecki
3811 if ((s
->size
& ~(align
- 1)) != s
->size
)
3814 if (s
->size
- size
>= sizeof(void *))
3817 if (!cache_match_memcg(s
, memcg
))
3826 __kmem_cache_alias(struct mem_cgroup
*memcg
, const char *name
, size_t size
,
3827 size_t align
, unsigned long flags
, void (*ctor
)(void *))
3829 struct kmem_cache
*s
;
3831 s
= find_mergeable(memcg
, size
, align
, flags
, name
, ctor
);
3835 * Adjust the object sizes so that we clear
3836 * the complete object on kzalloc.
3838 s
->object_size
= max(s
->object_size
, (int)size
);
3839 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3841 if (sysfs_slab_alias(s
, name
)) {
3850 int __kmem_cache_create(struct kmem_cache
*s
, unsigned long flags
)
3854 err
= kmem_cache_open(s
, flags
);
3858 /* Mutex is not taken during early boot */
3859 if (slab_state
<= UP
)
3862 mutex_unlock(&slab_mutex
);
3863 err
= sysfs_slab_add(s
);
3864 mutex_lock(&slab_mutex
);
3867 kmem_cache_close(s
);
3874 * Use the cpu notifier to insure that the cpu slabs are flushed when
3877 static int __cpuinit
slab_cpuup_callback(struct notifier_block
*nfb
,
3878 unsigned long action
, void *hcpu
)
3880 long cpu
= (long)hcpu
;
3881 struct kmem_cache
*s
;
3882 unsigned long flags
;
3885 case CPU_UP_CANCELED
:
3886 case CPU_UP_CANCELED_FROZEN
:
3888 case CPU_DEAD_FROZEN
:
3889 mutex_lock(&slab_mutex
);
3890 list_for_each_entry(s
, &slab_caches
, list
) {
3891 local_irq_save(flags
);
3892 __flush_cpu_slab(s
, cpu
);
3893 local_irq_restore(flags
);
3895 mutex_unlock(&slab_mutex
);
3903 static struct notifier_block __cpuinitdata slab_notifier
= {
3904 .notifier_call
= slab_cpuup_callback
3909 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, unsigned long caller
)
3911 struct kmem_cache
*s
;
3914 if (unlikely(size
> SLUB_MAX_SIZE
))
3915 return kmalloc_large(size
, gfpflags
);
3917 s
= get_slab(size
, gfpflags
);
3919 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3922 ret
= slab_alloc(s
, gfpflags
, caller
);
3924 /* Honor the call site pointer we received. */
3925 trace_kmalloc(caller
, ret
, size
, s
->size
, gfpflags
);
3931 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3932 int node
, unsigned long caller
)
3934 struct kmem_cache
*s
;
3937 if (unlikely(size
> SLUB_MAX_SIZE
)) {
3938 ret
= kmalloc_large_node(size
, gfpflags
, node
);
3940 trace_kmalloc_node(caller
, ret
,
3941 size
, PAGE_SIZE
<< get_order(size
),
3947 s
= get_slab(size
, gfpflags
);
3949 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3952 ret
= slab_alloc_node(s
, gfpflags
, node
, caller
);
3954 /* Honor the call site pointer we received. */
3955 trace_kmalloc_node(caller
, ret
, size
, s
->size
, gfpflags
, node
);
3962 static int count_inuse(struct page
*page
)
3967 static int count_total(struct page
*page
)
3969 return page
->objects
;
3973 #ifdef CONFIG_SLUB_DEBUG
3974 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3978 void *addr
= page_address(page
);
3980 if (!check_slab(s
, page
) ||
3981 !on_freelist(s
, page
, NULL
))
3984 /* Now we know that a valid freelist exists */
3985 bitmap_zero(map
, page
->objects
);
3987 get_map(s
, page
, map
);
3988 for_each_object(p
, s
, addr
, page
->objects
) {
3989 if (test_bit(slab_index(p
, s
, addr
), map
))
3990 if (!check_object(s
, page
, p
, SLUB_RED_INACTIVE
))
3994 for_each_object(p
, s
, addr
, page
->objects
)
3995 if (!test_bit(slab_index(p
, s
, addr
), map
))
3996 if (!check_object(s
, page
, p
, SLUB_RED_ACTIVE
))
4001 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
4005 validate_slab(s
, page
, map
);
4009 static int validate_slab_node(struct kmem_cache
*s
,
4010 struct kmem_cache_node
*n
, unsigned long *map
)
4012 unsigned long count
= 0;
4014 unsigned long flags
;
4016 spin_lock_irqsave(&n
->list_lock
, flags
);
4018 list_for_each_entry(page
, &n
->partial
, lru
) {
4019 validate_slab_slab(s
, page
, map
);
4022 if (count
!= n
->nr_partial
)
4023 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
4024 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
4026 if (!(s
->flags
& SLAB_STORE_USER
))
4029 list_for_each_entry(page
, &n
->full
, lru
) {
4030 validate_slab_slab(s
, page
, map
);
4033 if (count
!= atomic_long_read(&n
->nr_slabs
))
4034 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
4035 "counter=%ld\n", s
->name
, count
,
4036 atomic_long_read(&n
->nr_slabs
));
4039 spin_unlock_irqrestore(&n
->list_lock
, flags
);
4043 static long validate_slab_cache(struct kmem_cache
*s
)
4046 unsigned long count
= 0;
4047 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
4048 sizeof(unsigned long), GFP_KERNEL
);
4054 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4055 struct kmem_cache_node
*n
= get_node(s
, node
);
4057 count
+= validate_slab_node(s
, n
, map
);
4063 * Generate lists of code addresses where slabcache objects are allocated
4068 unsigned long count
;
4075 DECLARE_BITMAP(cpus
, NR_CPUS
);
4081 unsigned long count
;
4082 struct location
*loc
;
4085 static void free_loc_track(struct loc_track
*t
)
4088 free_pages((unsigned long)t
->loc
,
4089 get_order(sizeof(struct location
) * t
->max
));
4092 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
4097 order
= get_order(sizeof(struct location
) * max
);
4099 l
= (void *)__get_free_pages(flags
, order
);
4104 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
4112 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
4113 const struct track
*track
)
4115 long start
, end
, pos
;
4117 unsigned long caddr
;
4118 unsigned long age
= jiffies
- track
->when
;
4124 pos
= start
+ (end
- start
+ 1) / 2;
4127 * There is nothing at "end". If we end up there
4128 * we need to add something to before end.
4133 caddr
= t
->loc
[pos
].addr
;
4134 if (track
->addr
== caddr
) {
4140 if (age
< l
->min_time
)
4142 if (age
> l
->max_time
)
4145 if (track
->pid
< l
->min_pid
)
4146 l
->min_pid
= track
->pid
;
4147 if (track
->pid
> l
->max_pid
)
4148 l
->max_pid
= track
->pid
;
4150 cpumask_set_cpu(track
->cpu
,
4151 to_cpumask(l
->cpus
));
4153 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4157 if (track
->addr
< caddr
)
4164 * Not found. Insert new tracking element.
4166 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
4172 (t
->count
- pos
) * sizeof(struct location
));
4175 l
->addr
= track
->addr
;
4179 l
->min_pid
= track
->pid
;
4180 l
->max_pid
= track
->pid
;
4181 cpumask_clear(to_cpumask(l
->cpus
));
4182 cpumask_set_cpu(track
->cpu
, to_cpumask(l
->cpus
));
4183 nodes_clear(l
->nodes
);
4184 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4188 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
4189 struct page
*page
, enum track_item alloc
,
4192 void *addr
= page_address(page
);
4195 bitmap_zero(map
, page
->objects
);
4196 get_map(s
, page
, map
);
4198 for_each_object(p
, s
, addr
, page
->objects
)
4199 if (!test_bit(slab_index(p
, s
, addr
), map
))
4200 add_location(t
, s
, get_track(s
, p
, alloc
));
4203 static int list_locations(struct kmem_cache
*s
, char *buf
,
4204 enum track_item alloc
)
4208 struct loc_track t
= { 0, 0, NULL
};
4210 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
4211 sizeof(unsigned long), GFP_KERNEL
);
4213 if (!map
|| !alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
4216 return sprintf(buf
, "Out of memory\n");
4218 /* Push back cpu slabs */
4221 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4222 struct kmem_cache_node
*n
= get_node(s
, node
);
4223 unsigned long flags
;
4226 if (!atomic_long_read(&n
->nr_slabs
))
4229 spin_lock_irqsave(&n
->list_lock
, flags
);
4230 list_for_each_entry(page
, &n
->partial
, lru
)
4231 process_slab(&t
, s
, page
, alloc
, map
);
4232 list_for_each_entry(page
, &n
->full
, lru
)
4233 process_slab(&t
, s
, page
, alloc
, map
);
4234 spin_unlock_irqrestore(&n
->list_lock
, flags
);
4237 for (i
= 0; i
< t
.count
; i
++) {
4238 struct location
*l
= &t
.loc
[i
];
4240 if (len
> PAGE_SIZE
- KSYM_SYMBOL_LEN
- 100)
4242 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
4245 len
+= sprintf(buf
+ len
, "%pS", (void *)l
->addr
);
4247 len
+= sprintf(buf
+ len
, "<not-available>");
4249 if (l
->sum_time
!= l
->min_time
) {
4250 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
4252 (long)div_u64(l
->sum_time
, l
->count
),
4255 len
+= sprintf(buf
+ len
, " age=%ld",
4258 if (l
->min_pid
!= l
->max_pid
)
4259 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
4260 l
->min_pid
, l
->max_pid
);
4262 len
+= sprintf(buf
+ len
, " pid=%ld",
4265 if (num_online_cpus() > 1 &&
4266 !cpumask_empty(to_cpumask(l
->cpus
)) &&
4267 len
< PAGE_SIZE
- 60) {
4268 len
+= sprintf(buf
+ len
, " cpus=");
4269 len
+= cpulist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
4270 to_cpumask(l
->cpus
));
4273 if (nr_online_nodes
> 1 && !nodes_empty(l
->nodes
) &&
4274 len
< PAGE_SIZE
- 60) {
4275 len
+= sprintf(buf
+ len
, " nodes=");
4276 len
+= nodelist_scnprintf(buf
+ len
, PAGE_SIZE
- len
- 50,
4280 len
+= sprintf(buf
+ len
, "\n");
4286 len
+= sprintf(buf
, "No data\n");
4291 #ifdef SLUB_RESILIENCY_TEST
4292 static void resiliency_test(void)
4296 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 16 || SLUB_PAGE_SHIFT
< 10);
4298 printk(KERN_ERR
"SLUB resiliency testing\n");
4299 printk(KERN_ERR
"-----------------------\n");
4300 printk(KERN_ERR
"A. Corruption after allocation\n");
4302 p
= kzalloc(16, GFP_KERNEL
);
4304 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
4305 " 0x12->0x%p\n\n", p
+ 16);
4307 validate_slab_cache(kmalloc_caches
[4]);
4309 /* Hmmm... The next two are dangerous */
4310 p
= kzalloc(32, GFP_KERNEL
);
4311 p
[32 + sizeof(void *)] = 0x34;
4312 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
4313 " 0x34 -> -0x%p\n", p
);
4315 "If allocated object is overwritten then not detectable\n\n");
4317 validate_slab_cache(kmalloc_caches
[5]);
4318 p
= kzalloc(64, GFP_KERNEL
);
4319 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
4321 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
4324 "If allocated object is overwritten then not detectable\n\n");
4325 validate_slab_cache(kmalloc_caches
[6]);
4327 printk(KERN_ERR
"\nB. Corruption after free\n");
4328 p
= kzalloc(128, GFP_KERNEL
);
4331 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
4332 validate_slab_cache(kmalloc_caches
[7]);
4334 p
= kzalloc(256, GFP_KERNEL
);
4337 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
4339 validate_slab_cache(kmalloc_caches
[8]);
4341 p
= kzalloc(512, GFP_KERNEL
);
4344 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
4345 validate_slab_cache(kmalloc_caches
[9]);
4349 static void resiliency_test(void) {};
4354 enum slab_stat_type
{
4355 SL_ALL
, /* All slabs */
4356 SL_PARTIAL
, /* Only partially allocated slabs */
4357 SL_CPU
, /* Only slabs used for cpu caches */
4358 SL_OBJECTS
, /* Determine allocated objects not slabs */
4359 SL_TOTAL
/* Determine object capacity not slabs */
4362 #define SO_ALL (1 << SL_ALL)
4363 #define SO_PARTIAL (1 << SL_PARTIAL)
4364 #define SO_CPU (1 << SL_CPU)
4365 #define SO_OBJECTS (1 << SL_OBJECTS)
4366 #define SO_TOTAL (1 << SL_TOTAL)
4368 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
4369 char *buf
, unsigned long flags
)
4371 unsigned long total
= 0;
4374 unsigned long *nodes
;
4375 unsigned long *per_cpu
;
4377 nodes
= kzalloc(2 * sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
4380 per_cpu
= nodes
+ nr_node_ids
;
4382 if (flags
& SO_CPU
) {
4385 for_each_possible_cpu(cpu
) {
4386 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
4390 page
= ACCESS_ONCE(c
->page
);
4394 node
= page_to_nid(page
);
4395 if (flags
& SO_TOTAL
)
4397 else if (flags
& SO_OBJECTS
)
4405 page
= ACCESS_ONCE(c
->partial
);
4416 lock_memory_hotplug();
4417 #ifdef CONFIG_SLUB_DEBUG
4418 if (flags
& SO_ALL
) {
4419 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4420 struct kmem_cache_node
*n
= get_node(s
, node
);
4422 if (flags
& SO_TOTAL
)
4423 x
= atomic_long_read(&n
->total_objects
);
4424 else if (flags
& SO_OBJECTS
)
4425 x
= atomic_long_read(&n
->total_objects
) -
4426 count_partial(n
, count_free
);
4429 x
= atomic_long_read(&n
->nr_slabs
);
4436 if (flags
& SO_PARTIAL
) {
4437 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4438 struct kmem_cache_node
*n
= get_node(s
, node
);
4440 if (flags
& SO_TOTAL
)
4441 x
= count_partial(n
, count_total
);
4442 else if (flags
& SO_OBJECTS
)
4443 x
= count_partial(n
, count_inuse
);
4450 x
= sprintf(buf
, "%lu", total
);
4452 for_each_node_state(node
, N_NORMAL_MEMORY
)
4454 x
+= sprintf(buf
+ x
, " N%d=%lu",
4457 unlock_memory_hotplug();
4459 return x
+ sprintf(buf
+ x
, "\n");
4462 #ifdef CONFIG_SLUB_DEBUG
4463 static int any_slab_objects(struct kmem_cache
*s
)
4467 for_each_online_node(node
) {
4468 struct kmem_cache_node
*n
= get_node(s
, node
);
4473 if (atomic_long_read(&n
->total_objects
))
4480 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4481 #define to_slab(n) container_of(n, struct kmem_cache, kobj)
4483 struct slab_attribute
{
4484 struct attribute attr
;
4485 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
4486 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
4489 #define SLAB_ATTR_RO(_name) \
4490 static struct slab_attribute _name##_attr = \
4491 __ATTR(_name, 0400, _name##_show, NULL)
4493 #define SLAB_ATTR(_name) \
4494 static struct slab_attribute _name##_attr = \
4495 __ATTR(_name, 0600, _name##_show, _name##_store)
4497 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
4499 return sprintf(buf
, "%d\n", s
->size
);
4501 SLAB_ATTR_RO(slab_size
);
4503 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
4505 return sprintf(buf
, "%d\n", s
->align
);
4507 SLAB_ATTR_RO(align
);
4509 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
4511 return sprintf(buf
, "%d\n", s
->object_size
);
4513 SLAB_ATTR_RO(object_size
);
4515 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
4517 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
4519 SLAB_ATTR_RO(objs_per_slab
);
4521 static ssize_t
order_store(struct kmem_cache
*s
,
4522 const char *buf
, size_t length
)
4524 unsigned long order
;
4527 err
= strict_strtoul(buf
, 10, &order
);
4531 if (order
> slub_max_order
|| order
< slub_min_order
)
4534 calculate_sizes(s
, order
);
4538 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
4540 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
4544 static ssize_t
min_partial_show(struct kmem_cache
*s
, char *buf
)
4546 return sprintf(buf
, "%lu\n", s
->min_partial
);
4549 static ssize_t
min_partial_store(struct kmem_cache
*s
, const char *buf
,
4555 err
= strict_strtoul(buf
, 10, &min
);
4559 set_min_partial(s
, min
);
4562 SLAB_ATTR(min_partial
);
4564 static ssize_t
cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4566 return sprintf(buf
, "%u\n", s
->cpu_partial
);
4569 static ssize_t
cpu_partial_store(struct kmem_cache
*s
, const char *buf
,
4572 unsigned long objects
;
4575 err
= strict_strtoul(buf
, 10, &objects
);
4578 if (objects
&& kmem_cache_debug(s
))
4581 s
->cpu_partial
= objects
;
4585 SLAB_ATTR(cpu_partial
);
4587 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
4591 return sprintf(buf
, "%pS\n", s
->ctor
);
4595 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
4597 return sprintf(buf
, "%d\n", s
->refcount
- 1);
4599 SLAB_ATTR_RO(aliases
);
4601 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
4603 return show_slab_objects(s
, buf
, SO_PARTIAL
);
4605 SLAB_ATTR_RO(partial
);
4607 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
4609 return show_slab_objects(s
, buf
, SO_CPU
);
4611 SLAB_ATTR_RO(cpu_slabs
);
4613 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
4615 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
4617 SLAB_ATTR_RO(objects
);
4619 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
4621 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
4623 SLAB_ATTR_RO(objects_partial
);
4625 static ssize_t
slabs_cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4632 for_each_online_cpu(cpu
) {
4633 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
)->partial
;
4636 pages
+= page
->pages
;
4637 objects
+= page
->pobjects
;
4641 len
= sprintf(buf
, "%d(%d)", objects
, pages
);
4644 for_each_online_cpu(cpu
) {
4645 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
) ->partial
;
4647 if (page
&& len
< PAGE_SIZE
- 20)
4648 len
+= sprintf(buf
+ len
, " C%d=%d(%d)", cpu
,
4649 page
->pobjects
, page
->pages
);
4652 return len
+ sprintf(buf
+ len
, "\n");
4654 SLAB_ATTR_RO(slabs_cpu_partial
);
4656 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
4658 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
4661 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
4662 const char *buf
, size_t length
)
4664 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
4666 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
4669 SLAB_ATTR(reclaim_account
);
4671 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
4673 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
4675 SLAB_ATTR_RO(hwcache_align
);
4677 #ifdef CONFIG_ZONE_DMA
4678 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
4680 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
4682 SLAB_ATTR_RO(cache_dma
);
4685 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
4687 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
4689 SLAB_ATTR_RO(destroy_by_rcu
);
4691 static ssize_t
reserved_show(struct kmem_cache
*s
, char *buf
)
4693 return sprintf(buf
, "%d\n", s
->reserved
);
4695 SLAB_ATTR_RO(reserved
);
4697 #ifdef CONFIG_SLUB_DEBUG
4698 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
4700 return show_slab_objects(s
, buf
, SO_ALL
);
4702 SLAB_ATTR_RO(slabs
);
4704 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
4706 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
4708 SLAB_ATTR_RO(total_objects
);
4710 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
4712 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
4715 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
4716 const char *buf
, size_t length
)
4718 s
->flags
&= ~SLAB_DEBUG_FREE
;
4719 if (buf
[0] == '1') {
4720 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4721 s
->flags
|= SLAB_DEBUG_FREE
;
4725 SLAB_ATTR(sanity_checks
);
4727 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
4729 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
4732 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
4735 s
->flags
&= ~SLAB_TRACE
;
4736 if (buf
[0] == '1') {
4737 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4738 s
->flags
|= SLAB_TRACE
;
4744 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
4746 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
4749 static ssize_t
red_zone_store(struct kmem_cache
*s
,
4750 const char *buf
, size_t length
)
4752 if (any_slab_objects(s
))
4755 s
->flags
&= ~SLAB_RED_ZONE
;
4756 if (buf
[0] == '1') {
4757 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4758 s
->flags
|= SLAB_RED_ZONE
;
4760 calculate_sizes(s
, -1);
4763 SLAB_ATTR(red_zone
);
4765 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
4767 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
4770 static ssize_t
poison_store(struct kmem_cache
*s
,
4771 const char *buf
, size_t length
)
4773 if (any_slab_objects(s
))
4776 s
->flags
&= ~SLAB_POISON
;
4777 if (buf
[0] == '1') {
4778 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4779 s
->flags
|= SLAB_POISON
;
4781 calculate_sizes(s
, -1);
4786 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4788 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4791 static ssize_t
store_user_store(struct kmem_cache
*s
,
4792 const char *buf
, size_t length
)
4794 if (any_slab_objects(s
))
4797 s
->flags
&= ~SLAB_STORE_USER
;
4798 if (buf
[0] == '1') {
4799 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4800 s
->flags
|= SLAB_STORE_USER
;
4802 calculate_sizes(s
, -1);
4805 SLAB_ATTR(store_user
);
4807 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4812 static ssize_t
validate_store(struct kmem_cache
*s
,
4813 const char *buf
, size_t length
)
4817 if (buf
[0] == '1') {
4818 ret
= validate_slab_cache(s
);
4824 SLAB_ATTR(validate
);
4826 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4828 if (!(s
->flags
& SLAB_STORE_USER
))
4830 return list_locations(s
, buf
, TRACK_ALLOC
);
4832 SLAB_ATTR_RO(alloc_calls
);
4834 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4836 if (!(s
->flags
& SLAB_STORE_USER
))
4838 return list_locations(s
, buf
, TRACK_FREE
);
4840 SLAB_ATTR_RO(free_calls
);
4841 #endif /* CONFIG_SLUB_DEBUG */
4843 #ifdef CONFIG_FAILSLAB
4844 static ssize_t
failslab_show(struct kmem_cache
*s
, char *buf
)
4846 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_FAILSLAB
));
4849 static ssize_t
failslab_store(struct kmem_cache
*s
, const char *buf
,
4852 s
->flags
&= ~SLAB_FAILSLAB
;
4854 s
->flags
|= SLAB_FAILSLAB
;
4857 SLAB_ATTR(failslab
);
4860 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4865 static ssize_t
shrink_store(struct kmem_cache
*s
,
4866 const char *buf
, size_t length
)
4868 if (buf
[0] == '1') {
4869 int rc
= kmem_cache_shrink(s
);
4880 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4882 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4885 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4886 const char *buf
, size_t length
)
4888 unsigned long ratio
;
4891 err
= strict_strtoul(buf
, 10, &ratio
);
4896 s
->remote_node_defrag_ratio
= ratio
* 10;
4900 SLAB_ATTR(remote_node_defrag_ratio
);
4903 #ifdef CONFIG_SLUB_STATS
4904 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4906 unsigned long sum
= 0;
4909 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4914 for_each_online_cpu(cpu
) {
4915 unsigned x
= per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
];
4921 len
= sprintf(buf
, "%lu", sum
);
4924 for_each_online_cpu(cpu
) {
4925 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4926 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4930 return len
+ sprintf(buf
+ len
, "\n");
4933 static void clear_stat(struct kmem_cache
*s
, enum stat_item si
)
4937 for_each_online_cpu(cpu
)
4938 per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
] = 0;
4941 #define STAT_ATTR(si, text) \
4942 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4944 return show_stat(s, buf, si); \
4946 static ssize_t text##_store(struct kmem_cache *s, \
4947 const char *buf, size_t length) \
4949 if (buf[0] != '0') \
4951 clear_stat(s, si); \
4956 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4957 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4958 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4959 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4960 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4961 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4962 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4963 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4964 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4965 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4966 STAT_ATTR(ALLOC_NODE_MISMATCH
, alloc_node_mismatch
);
4967 STAT_ATTR(FREE_SLAB
, free_slab
);
4968 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4969 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4970 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4971 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4972 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4973 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4974 STAT_ATTR(DEACTIVATE_BYPASS
, deactivate_bypass
);
4975 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4976 STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL
, cmpxchg_double_cpu_fail
);
4977 STAT_ATTR(CMPXCHG_DOUBLE_FAIL
, cmpxchg_double_fail
);
4978 STAT_ATTR(CPU_PARTIAL_ALLOC
, cpu_partial_alloc
);
4979 STAT_ATTR(CPU_PARTIAL_FREE
, cpu_partial_free
);
4980 STAT_ATTR(CPU_PARTIAL_NODE
, cpu_partial_node
);
4981 STAT_ATTR(CPU_PARTIAL_DRAIN
, cpu_partial_drain
);
4984 static struct attribute
*slab_attrs
[] = {
4985 &slab_size_attr
.attr
,
4986 &object_size_attr
.attr
,
4987 &objs_per_slab_attr
.attr
,
4989 &min_partial_attr
.attr
,
4990 &cpu_partial_attr
.attr
,
4992 &objects_partial_attr
.attr
,
4994 &cpu_slabs_attr
.attr
,
4998 &hwcache_align_attr
.attr
,
4999 &reclaim_account_attr
.attr
,
5000 &destroy_by_rcu_attr
.attr
,
5002 &reserved_attr
.attr
,
5003 &slabs_cpu_partial_attr
.attr
,
5004 #ifdef CONFIG_SLUB_DEBUG
5005 &total_objects_attr
.attr
,
5007 &sanity_checks_attr
.attr
,
5009 &red_zone_attr
.attr
,
5011 &store_user_attr
.attr
,
5012 &validate_attr
.attr
,
5013 &alloc_calls_attr
.attr
,
5014 &free_calls_attr
.attr
,
5016 #ifdef CONFIG_ZONE_DMA
5017 &cache_dma_attr
.attr
,
5020 &remote_node_defrag_ratio_attr
.attr
,
5022 #ifdef CONFIG_SLUB_STATS
5023 &alloc_fastpath_attr
.attr
,
5024 &alloc_slowpath_attr
.attr
,
5025 &free_fastpath_attr
.attr
,
5026 &free_slowpath_attr
.attr
,
5027 &free_frozen_attr
.attr
,
5028 &free_add_partial_attr
.attr
,
5029 &free_remove_partial_attr
.attr
,
5030 &alloc_from_partial_attr
.attr
,
5031 &alloc_slab_attr
.attr
,
5032 &alloc_refill_attr
.attr
,
5033 &alloc_node_mismatch_attr
.attr
,
5034 &free_slab_attr
.attr
,
5035 &cpuslab_flush_attr
.attr
,
5036 &deactivate_full_attr
.attr
,
5037 &deactivate_empty_attr
.attr
,
5038 &deactivate_to_head_attr
.attr
,
5039 &deactivate_to_tail_attr
.attr
,
5040 &deactivate_remote_frees_attr
.attr
,
5041 &deactivate_bypass_attr
.attr
,
5042 &order_fallback_attr
.attr
,
5043 &cmpxchg_double_fail_attr
.attr
,
5044 &cmpxchg_double_cpu_fail_attr
.attr
,
5045 &cpu_partial_alloc_attr
.attr
,
5046 &cpu_partial_free_attr
.attr
,
5047 &cpu_partial_node_attr
.attr
,
5048 &cpu_partial_drain_attr
.attr
,
5050 #ifdef CONFIG_FAILSLAB
5051 &failslab_attr
.attr
,
5057 static struct attribute_group slab_attr_group
= {
5058 .attrs
= slab_attrs
,
5061 static ssize_t
slab_attr_show(struct kobject
*kobj
,
5062 struct attribute
*attr
,
5065 struct slab_attribute
*attribute
;
5066 struct kmem_cache
*s
;
5069 attribute
= to_slab_attr(attr
);
5072 if (!attribute
->show
)
5075 err
= attribute
->show(s
, buf
);
5080 static ssize_t
slab_attr_store(struct kobject
*kobj
,
5081 struct attribute
*attr
,
5082 const char *buf
, size_t len
)
5084 struct slab_attribute
*attribute
;
5085 struct kmem_cache
*s
;
5088 attribute
= to_slab_attr(attr
);
5091 if (!attribute
->store
)
5094 err
= attribute
->store(s
, buf
, len
);
5099 static const struct sysfs_ops slab_sysfs_ops
= {
5100 .show
= slab_attr_show
,
5101 .store
= slab_attr_store
,
5104 static struct kobj_type slab_ktype
= {
5105 .sysfs_ops
= &slab_sysfs_ops
,
5108 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
5110 struct kobj_type
*ktype
= get_ktype(kobj
);
5112 if (ktype
== &slab_ktype
)
5117 static const struct kset_uevent_ops slab_uevent_ops
= {
5118 .filter
= uevent_filter
,
5121 static struct kset
*slab_kset
;
5123 #define ID_STR_LENGTH 64
5125 /* Create a unique string id for a slab cache:
5127 * Format :[flags-]size
5129 static char *create_unique_id(struct kmem_cache
*s
)
5131 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
5138 * First flags affecting slabcache operations. We will only
5139 * get here for aliasable slabs so we do not need to support
5140 * too many flags. The flags here must cover all flags that
5141 * are matched during merging to guarantee that the id is
5144 if (s
->flags
& SLAB_CACHE_DMA
)
5146 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
5148 if (s
->flags
& SLAB_DEBUG_FREE
)
5150 if (!(s
->flags
& SLAB_NOTRACK
))
5154 p
+= sprintf(p
, "%07d", s
->size
);
5156 #ifdef CONFIG_MEMCG_KMEM
5157 if (!is_root_cache(s
))
5158 p
+= sprintf(p
, "-%08d", memcg_cache_id(s
->memcg_params
->memcg
));
5161 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
5165 static int sysfs_slab_add(struct kmem_cache
*s
)
5169 int unmergeable
= slab_unmergeable(s
);
5173 * Slabcache can never be merged so we can use the name proper.
5174 * This is typically the case for debug situations. In that
5175 * case we can catch duplicate names easily.
5177 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
5181 * Create a unique name for the slab as a target
5184 name
= create_unique_id(s
);
5187 s
->kobj
.kset
= slab_kset
;
5188 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, name
);
5190 kobject_put(&s
->kobj
);
5194 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
5196 kobject_del(&s
->kobj
);
5197 kobject_put(&s
->kobj
);
5200 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
5202 /* Setup first alias */
5203 sysfs_slab_alias(s
, s
->name
);
5209 static void sysfs_slab_remove(struct kmem_cache
*s
)
5211 if (slab_state
< FULL
)
5213 * Sysfs has not been setup yet so no need to remove the
5218 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
5219 kobject_del(&s
->kobj
);
5220 kobject_put(&s
->kobj
);
5224 * Need to buffer aliases during bootup until sysfs becomes
5225 * available lest we lose that information.
5227 struct saved_alias
{
5228 struct kmem_cache
*s
;
5230 struct saved_alias
*next
;
5233 static struct saved_alias
*alias_list
;
5235 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
5237 struct saved_alias
*al
;
5239 if (slab_state
== FULL
) {
5241 * If we have a leftover link then remove it.
5243 sysfs_remove_link(&slab_kset
->kobj
, name
);
5244 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
5247 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
5253 al
->next
= alias_list
;
5258 static int __init
slab_sysfs_init(void)
5260 struct kmem_cache
*s
;
5263 mutex_lock(&slab_mutex
);
5265 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
5267 mutex_unlock(&slab_mutex
);
5268 printk(KERN_ERR
"Cannot register slab subsystem.\n");
5274 list_for_each_entry(s
, &slab_caches
, list
) {
5275 err
= sysfs_slab_add(s
);
5277 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
5278 " to sysfs\n", s
->name
);
5281 while (alias_list
) {
5282 struct saved_alias
*al
= alias_list
;
5284 alias_list
= alias_list
->next
;
5285 err
= sysfs_slab_alias(al
->s
, al
->name
);
5287 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
5288 " %s to sysfs\n", al
->name
);
5292 mutex_unlock(&slab_mutex
);
5297 __initcall(slab_sysfs_init
);
5298 #endif /* CONFIG_SYSFS */
5301 * The /proc/slabinfo ABI
5303 #ifdef CONFIG_SLABINFO
5304 void get_slabinfo(struct kmem_cache
*s
, struct slabinfo
*sinfo
)
5306 unsigned long nr_partials
= 0;
5307 unsigned long nr_slabs
= 0;
5308 unsigned long nr_objs
= 0;
5309 unsigned long nr_free
= 0;
5312 for_each_online_node(node
) {
5313 struct kmem_cache_node
*n
= get_node(s
, node
);
5318 nr_partials
+= n
->nr_partial
;
5319 nr_slabs
+= atomic_long_read(&n
->nr_slabs
);
5320 nr_objs
+= atomic_long_read(&n
->total_objects
);
5321 nr_free
+= count_partial(n
, count_free
);
5324 sinfo
->active_objs
= nr_objs
- nr_free
;
5325 sinfo
->num_objs
= nr_objs
;
5326 sinfo
->active_slabs
= nr_slabs
;
5327 sinfo
->num_slabs
= nr_slabs
;
5328 sinfo
->objects_per_slab
= oo_objects(s
->oo
);
5329 sinfo
->cache_order
= oo_order(s
->oo
);
5332 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*s
)
5336 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
5337 size_t count
, loff_t
*ppos
)
5341 #endif /* CONFIG_SLABINFO */