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/notifier.h>
22 #include <linux/seq_file.h>
23 #include <linux/kmemcheck.h>
24 #include <linux/cpu.h>
25 #include <linux/cpuset.h>
26 #include <linux/mempolicy.h>
27 #include <linux/ctype.h>
28 #include <linux/debugobjects.h>
29 #include <linux/kallsyms.h>
30 #include <linux/memory.h>
31 #include <linux/math64.h>
32 #include <linux/fault-inject.h>
33 #include <linux/stacktrace.h>
34 #include <linux/prefetch.h>
35 #include <linux/memcontrol.h>
37 #include <trace/events/kmem.h>
43 * 1. slab_mutex (Global Mutex)
45 * 3. slab_lock(page) (Only on some arches and for debugging)
49 * The role of the slab_mutex is to protect the list of all the slabs
50 * and to synchronize major metadata changes to slab cache structures.
52 * The slab_lock is only used for debugging and on arches that do not
53 * have the ability to do a cmpxchg_double. It only protects the second
54 * double word in the page struct. Meaning
55 * A. page->freelist -> List of object free in a page
56 * B. page->counters -> Counters of objects
57 * C. page->frozen -> frozen state
59 * If a slab is frozen then it is exempt from list management. It is not
60 * on any list. The processor that froze the slab is the one who can
61 * perform list operations on the page. Other processors may put objects
62 * onto the freelist but the processor that froze the slab is the only
63 * one that can retrieve the objects from the page's freelist.
65 * The list_lock protects the partial and full list on each node and
66 * the partial slab counter. If taken then no new slabs may be added or
67 * removed from the lists nor make the number of partial slabs be modified.
68 * (Note that the total number of slabs is an atomic value that may be
69 * modified without taking the list lock).
71 * The list_lock is a centralized lock and thus we avoid taking it as
72 * much as possible. As long as SLUB does not have to handle partial
73 * slabs, operations can continue without any centralized lock. F.e.
74 * allocating a long series of objects that fill up slabs does not require
76 * Interrupts are disabled during allocation and deallocation in order to
77 * make the slab allocator safe to use in the context of an irq. In addition
78 * interrupts are disabled to ensure that the processor does not change
79 * while handling per_cpu slabs, due to kernel preemption.
81 * SLUB assigns one slab for allocation to each processor.
82 * Allocations only occur from these slabs called cpu slabs.
84 * Slabs with free elements are kept on a partial list and during regular
85 * operations no list for full slabs is used. If an object in a full slab is
86 * freed then the slab will show up again on the partial lists.
87 * We track full slabs for debugging purposes though because otherwise we
88 * cannot scan all objects.
90 * Slabs are freed when they become empty. Teardown and setup is
91 * minimal so we rely on the page allocators per cpu caches for
92 * fast frees and allocs.
94 * Overloading of page flags that are otherwise used for LRU management.
96 * PageActive The slab is frozen and exempt from list processing.
97 * This means that the slab is dedicated to a purpose
98 * such as satisfying allocations for a specific
99 * processor. Objects may be freed in the slab while
100 * it is frozen but slab_free will then skip the usual
101 * list operations. It is up to the processor holding
102 * the slab to integrate the slab into the slab lists
103 * when the slab is no longer needed.
105 * One use of this flag is to mark slabs that are
106 * used for allocations. Then such a slab becomes a cpu
107 * slab. The cpu slab may be equipped with an additional
108 * freelist that allows lockless access to
109 * free objects in addition to the regular freelist
110 * that requires the slab lock.
112 * PageError Slab requires special handling due to debug
113 * options set. This moves slab handling out of
114 * the fast path and disables lockless freelists.
117 static inline int kmem_cache_debug(struct kmem_cache
*s
)
119 #ifdef CONFIG_SLUB_DEBUG
120 return unlikely(s
->flags
& SLAB_DEBUG_FLAGS
);
126 static inline bool kmem_cache_has_cpu_partial(struct kmem_cache
*s
)
128 #ifdef CONFIG_SLUB_CPU_PARTIAL
129 return !kmem_cache_debug(s
);
136 * Issues still to be resolved:
138 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
140 * - Variable sizing of the per node arrays
143 /* Enable to test recovery from slab corruption on boot */
144 #undef SLUB_RESILIENCY_TEST
146 /* Enable to log cmpxchg failures */
147 #undef SLUB_DEBUG_CMPXCHG
150 * Mininum number of partial slabs. These will be left on the partial
151 * lists even if they are empty. kmem_cache_shrink may reclaim them.
153 #define MIN_PARTIAL 5
156 * Maximum number of desirable partial slabs.
157 * The existence of more partial slabs makes kmem_cache_shrink
158 * sort the partial list by the number of objects in use.
160 #define MAX_PARTIAL 10
162 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
163 SLAB_POISON | SLAB_STORE_USER)
166 * Debugging flags that require metadata to be stored in the slab. These get
167 * disabled when slub_debug=O is used and a cache's min order increases with
170 #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
173 * Set of flags that will prevent slab merging
175 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
176 SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
179 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
180 SLAB_CACHE_DMA | SLAB_NOTRACK)
183 #define OO_MASK ((1 << OO_SHIFT) - 1)
184 #define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */
186 /* Internal SLUB flags */
187 #define __OBJECT_POISON 0x80000000UL /* Poison object */
188 #define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */
191 static struct notifier_block slab_notifier
;
195 * Tracking user of a slab.
197 #define TRACK_ADDRS_COUNT 16
199 unsigned long addr
; /* Called from address */
200 #ifdef CONFIG_STACKTRACE
201 unsigned long addrs
[TRACK_ADDRS_COUNT
]; /* Called from address */
203 int cpu
; /* Was running on cpu */
204 int pid
; /* Pid context */
205 unsigned long when
; /* When did the operation occur */
208 enum track_item
{ TRACK_ALLOC
, TRACK_FREE
};
211 static int sysfs_slab_add(struct kmem_cache
*);
212 static int sysfs_slab_alias(struct kmem_cache
*, const char *);
213 static void memcg_propagate_slab_attrs(struct kmem_cache
*s
);
215 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
216 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
218 static inline void memcg_propagate_slab_attrs(struct kmem_cache
*s
) { }
221 static inline void stat(const struct kmem_cache
*s
, enum stat_item si
)
223 #ifdef CONFIG_SLUB_STATS
225 * The rmw is racy on a preemptible kernel but this is acceptable, so
226 * avoid this_cpu_add()'s irq-disable overhead.
228 raw_cpu_inc(s
->cpu_slab
->stat
[si
]);
232 /********************************************************************
233 * Core slab cache functions
234 *******************************************************************/
236 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
238 return s
->node
[node
];
241 /* Verify that a pointer has an address that is valid within a slab page */
242 static inline int check_valid_pointer(struct kmem_cache
*s
,
243 struct page
*page
, const void *object
)
250 base
= page_address(page
);
251 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
252 (object
- base
) % s
->size
) {
259 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
261 return *(void **)(object
+ s
->offset
);
264 static void prefetch_freepointer(const struct kmem_cache
*s
, void *object
)
266 prefetch(object
+ s
->offset
);
269 static inline void *get_freepointer_safe(struct kmem_cache
*s
, void *object
)
273 #ifdef CONFIG_DEBUG_PAGEALLOC
274 probe_kernel_read(&p
, (void **)(object
+ s
->offset
), sizeof(p
));
276 p
= get_freepointer(s
, object
);
281 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
283 *(void **)(object
+ s
->offset
) = fp
;
286 /* Loop over all objects in a slab */
287 #define for_each_object(__p, __s, __addr, __objects) \
288 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
291 /* Determine object index from a given position */
292 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
294 return (p
- addr
) / s
->size
;
297 static inline size_t slab_ksize(const struct kmem_cache
*s
)
299 #ifdef CONFIG_SLUB_DEBUG
301 * Debugging requires use of the padding between object
302 * and whatever may come after it.
304 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
305 return s
->object_size
;
309 * If we have the need to store the freelist pointer
310 * back there or track user information then we can
311 * only use the space before that information.
313 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
316 * Else we can use all the padding etc for the allocation
321 static inline int order_objects(int order
, unsigned long size
, int reserved
)
323 return ((PAGE_SIZE
<< order
) - reserved
) / size
;
326 static inline struct kmem_cache_order_objects
oo_make(int order
,
327 unsigned long size
, int reserved
)
329 struct kmem_cache_order_objects x
= {
330 (order
<< OO_SHIFT
) + order_objects(order
, size
, reserved
)
336 static inline int oo_order(struct kmem_cache_order_objects x
)
338 return x
.x
>> OO_SHIFT
;
341 static inline int oo_objects(struct kmem_cache_order_objects x
)
343 return x
.x
& OO_MASK
;
347 * Per slab locking using the pagelock
349 static __always_inline
void slab_lock(struct page
*page
)
351 bit_spin_lock(PG_locked
, &page
->flags
);
354 static __always_inline
void slab_unlock(struct page
*page
)
356 __bit_spin_unlock(PG_locked
, &page
->flags
);
359 static inline void set_page_slub_counters(struct page
*page
, unsigned long counters_new
)
362 tmp
.counters
= counters_new
;
364 * page->counters can cover frozen/inuse/objects as well
365 * as page->_count. If we assign to ->counters directly
366 * we run the risk of losing updates to page->_count, so
367 * be careful and only assign to the fields we need.
369 page
->frozen
= tmp
.frozen
;
370 page
->inuse
= tmp
.inuse
;
371 page
->objects
= tmp
.objects
;
374 /* Interrupts must be disabled (for the fallback code to work right) */
375 static inline bool __cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
376 void *freelist_old
, unsigned long counters_old
,
377 void *freelist_new
, unsigned long counters_new
,
380 VM_BUG_ON(!irqs_disabled());
381 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
382 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
383 if (s
->flags
& __CMPXCHG_DOUBLE
) {
384 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
385 freelist_old
, counters_old
,
386 freelist_new
, counters_new
))
392 if (page
->freelist
== freelist_old
&&
393 page
->counters
== counters_old
) {
394 page
->freelist
= freelist_new
;
395 set_page_slub_counters(page
, counters_new
);
403 stat(s
, CMPXCHG_DOUBLE_FAIL
);
405 #ifdef SLUB_DEBUG_CMPXCHG
406 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
412 static inline bool cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
413 void *freelist_old
, unsigned long counters_old
,
414 void *freelist_new
, unsigned long counters_new
,
417 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
418 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
419 if (s
->flags
& __CMPXCHG_DOUBLE
) {
420 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
421 freelist_old
, counters_old
,
422 freelist_new
, counters_new
))
429 local_irq_save(flags
);
431 if (page
->freelist
== freelist_old
&&
432 page
->counters
== counters_old
) {
433 page
->freelist
= freelist_new
;
434 set_page_slub_counters(page
, counters_new
);
436 local_irq_restore(flags
);
440 local_irq_restore(flags
);
444 stat(s
, CMPXCHG_DOUBLE_FAIL
);
446 #ifdef SLUB_DEBUG_CMPXCHG
447 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
453 #ifdef CONFIG_SLUB_DEBUG
455 * Determine a map of object in use on a page.
457 * Node listlock must be held to guarantee that the page does
458 * not vanish from under us.
460 static void get_map(struct kmem_cache
*s
, struct page
*page
, unsigned long *map
)
463 void *addr
= page_address(page
);
465 for (p
= page
->freelist
; p
; p
= get_freepointer(s
, p
))
466 set_bit(slab_index(p
, s
, addr
), map
);
472 #ifdef CONFIG_SLUB_DEBUG_ON
473 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
475 static int slub_debug
;
478 static char *slub_debug_slabs
;
479 static int disable_higher_order_debug
;
484 static void print_section(char *text
, u8
*addr
, unsigned int length
)
486 print_hex_dump(KERN_ERR
, text
, DUMP_PREFIX_ADDRESS
, 16, 1, addr
,
490 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
491 enum track_item alloc
)
496 p
= object
+ s
->offset
+ sizeof(void *);
498 p
= object
+ s
->inuse
;
503 static void set_track(struct kmem_cache
*s
, void *object
,
504 enum track_item alloc
, unsigned long addr
)
506 struct track
*p
= get_track(s
, object
, alloc
);
509 #ifdef CONFIG_STACKTRACE
510 struct stack_trace trace
;
513 trace
.nr_entries
= 0;
514 trace
.max_entries
= TRACK_ADDRS_COUNT
;
515 trace
.entries
= p
->addrs
;
517 save_stack_trace(&trace
);
519 /* See rant in lockdep.c */
520 if (trace
.nr_entries
!= 0 &&
521 trace
.entries
[trace
.nr_entries
- 1] == ULONG_MAX
)
524 for (i
= trace
.nr_entries
; i
< TRACK_ADDRS_COUNT
; i
++)
528 p
->cpu
= smp_processor_id();
529 p
->pid
= current
->pid
;
532 memset(p
, 0, sizeof(struct track
));
535 static void init_tracking(struct kmem_cache
*s
, void *object
)
537 if (!(s
->flags
& SLAB_STORE_USER
))
540 set_track(s
, object
, TRACK_FREE
, 0UL);
541 set_track(s
, object
, TRACK_ALLOC
, 0UL);
544 static void print_track(const char *s
, struct track
*t
)
549 printk(KERN_ERR
"INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
550 s
, (void *)t
->addr
, jiffies
- t
->when
, t
->cpu
, t
->pid
);
551 #ifdef CONFIG_STACKTRACE
554 for (i
= 0; i
< TRACK_ADDRS_COUNT
; i
++)
556 printk(KERN_ERR
"\t%pS\n", (void *)t
->addrs
[i
]);
563 static void print_tracking(struct kmem_cache
*s
, void *object
)
565 if (!(s
->flags
& SLAB_STORE_USER
))
568 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
569 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
572 static void print_page_info(struct page
*page
)
575 "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
576 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
580 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
586 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
588 printk(KERN_ERR
"========================================"
589 "=====================================\n");
590 printk(KERN_ERR
"BUG %s (%s): %s\n", s
->name
, print_tainted(), buf
);
591 printk(KERN_ERR
"----------------------------------------"
592 "-------------------------------------\n\n");
594 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
597 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
603 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
605 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
608 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
610 unsigned int off
; /* Offset of last byte */
611 u8
*addr
= page_address(page
);
613 print_tracking(s
, p
);
615 print_page_info(page
);
617 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
618 p
, p
- addr
, get_freepointer(s
, p
));
621 print_section("Bytes b4 ", p
- 16, 16);
623 print_section("Object ", p
, min_t(unsigned long, s
->object_size
,
625 if (s
->flags
& SLAB_RED_ZONE
)
626 print_section("Redzone ", p
+ s
->object_size
,
627 s
->inuse
- s
->object_size
);
630 off
= s
->offset
+ sizeof(void *);
634 if (s
->flags
& SLAB_STORE_USER
)
635 off
+= 2 * sizeof(struct track
);
638 /* Beginning of the filler is the free pointer */
639 print_section("Padding ", p
+ off
, s
->size
- off
);
644 static void object_err(struct kmem_cache
*s
, struct page
*page
,
645 u8
*object
, char *reason
)
647 slab_bug(s
, "%s", reason
);
648 print_trailer(s
, page
, object
);
651 static void slab_err(struct kmem_cache
*s
, struct page
*page
,
652 const char *fmt
, ...)
658 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
660 slab_bug(s
, "%s", buf
);
661 print_page_info(page
);
665 static void init_object(struct kmem_cache
*s
, void *object
, u8 val
)
669 if (s
->flags
& __OBJECT_POISON
) {
670 memset(p
, POISON_FREE
, s
->object_size
- 1);
671 p
[s
->object_size
- 1] = POISON_END
;
674 if (s
->flags
& SLAB_RED_ZONE
)
675 memset(p
+ s
->object_size
, val
, s
->inuse
- s
->object_size
);
678 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
679 void *from
, void *to
)
681 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
682 memset(from
, data
, to
- from
);
685 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
686 u8
*object
, char *what
,
687 u8
*start
, unsigned int value
, unsigned int bytes
)
692 fault
= memchr_inv(start
, value
, bytes
);
697 while (end
> fault
&& end
[-1] == value
)
700 slab_bug(s
, "%s overwritten", what
);
701 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
702 fault
, end
- 1, fault
[0], value
);
703 print_trailer(s
, page
, object
);
705 restore_bytes(s
, what
, value
, fault
, end
);
713 * Bytes of the object to be managed.
714 * If the freepointer may overlay the object then the free
715 * pointer is the first word of the object.
717 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
720 * object + s->object_size
721 * Padding to reach word boundary. This is also used for Redzoning.
722 * Padding is extended by another word if Redzoning is enabled and
723 * object_size == inuse.
725 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
726 * 0xcc (RED_ACTIVE) for objects in use.
729 * Meta data starts here.
731 * A. Free pointer (if we cannot overwrite object on free)
732 * B. Tracking data for SLAB_STORE_USER
733 * C. Padding to reach required alignment boundary or at mininum
734 * one word if debugging is on to be able to detect writes
735 * before the word boundary.
737 * Padding is done using 0x5a (POISON_INUSE)
740 * Nothing is used beyond s->size.
742 * If slabcaches are merged then the object_size and inuse boundaries are mostly
743 * ignored. And therefore no slab options that rely on these boundaries
744 * may be used with merged slabcaches.
747 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
749 unsigned long off
= s
->inuse
; /* The end of info */
752 /* Freepointer is placed after the object. */
753 off
+= sizeof(void *);
755 if (s
->flags
& SLAB_STORE_USER
)
756 /* We also have user information there */
757 off
+= 2 * sizeof(struct track
);
762 return check_bytes_and_report(s
, page
, p
, "Object padding",
763 p
+ off
, POISON_INUSE
, s
->size
- off
);
766 /* Check the pad bytes at the end of a slab page */
767 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
775 if (!(s
->flags
& SLAB_POISON
))
778 start
= page_address(page
);
779 length
= (PAGE_SIZE
<< compound_order(page
)) - s
->reserved
;
780 end
= start
+ length
;
781 remainder
= length
% s
->size
;
785 fault
= memchr_inv(end
- remainder
, POISON_INUSE
, remainder
);
788 while (end
> fault
&& end
[-1] == POISON_INUSE
)
791 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
792 print_section("Padding ", end
- remainder
, remainder
);
794 restore_bytes(s
, "slab padding", POISON_INUSE
, end
- remainder
, end
);
798 static int check_object(struct kmem_cache
*s
, struct page
*page
,
799 void *object
, u8 val
)
802 u8
*endobject
= object
+ s
->object_size
;
804 if (s
->flags
& SLAB_RED_ZONE
) {
805 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
806 endobject
, val
, s
->inuse
- s
->object_size
))
809 if ((s
->flags
& SLAB_POISON
) && s
->object_size
< s
->inuse
) {
810 check_bytes_and_report(s
, page
, p
, "Alignment padding",
811 endobject
, POISON_INUSE
,
812 s
->inuse
- s
->object_size
);
816 if (s
->flags
& SLAB_POISON
) {
817 if (val
!= SLUB_RED_ACTIVE
&& (s
->flags
& __OBJECT_POISON
) &&
818 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
819 POISON_FREE
, s
->object_size
- 1) ||
820 !check_bytes_and_report(s
, page
, p
, "Poison",
821 p
+ s
->object_size
- 1, POISON_END
, 1)))
824 * check_pad_bytes cleans up on its own.
826 check_pad_bytes(s
, page
, p
);
829 if (!s
->offset
&& val
== SLUB_RED_ACTIVE
)
831 * Object and freepointer overlap. Cannot check
832 * freepointer while object is allocated.
836 /* Check free pointer validity */
837 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
838 object_err(s
, page
, p
, "Freepointer corrupt");
840 * No choice but to zap it and thus lose the remainder
841 * of the free objects in this slab. May cause
842 * another error because the object count is now wrong.
844 set_freepointer(s
, p
, NULL
);
850 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
854 VM_BUG_ON(!irqs_disabled());
856 if (!PageSlab(page
)) {
857 slab_err(s
, page
, "Not a valid slab page");
861 maxobj
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
862 if (page
->objects
> maxobj
) {
863 slab_err(s
, page
, "objects %u > max %u",
864 s
->name
, page
->objects
, maxobj
);
867 if (page
->inuse
> page
->objects
) {
868 slab_err(s
, page
, "inuse %u > max %u",
869 s
->name
, page
->inuse
, page
->objects
);
872 /* Slab_pad_check fixes things up after itself */
873 slab_pad_check(s
, page
);
878 * Determine if a certain object on a page is on the freelist. Must hold the
879 * slab lock to guarantee that the chains are in a consistent state.
881 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
886 unsigned long max_objects
;
889 while (fp
&& nr
<= page
->objects
) {
892 if (!check_valid_pointer(s
, page
, fp
)) {
894 object_err(s
, page
, object
,
895 "Freechain corrupt");
896 set_freepointer(s
, object
, NULL
);
898 slab_err(s
, page
, "Freepointer corrupt");
899 page
->freelist
= NULL
;
900 page
->inuse
= page
->objects
;
901 slab_fix(s
, "Freelist cleared");
907 fp
= get_freepointer(s
, object
);
911 max_objects
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
912 if (max_objects
> MAX_OBJS_PER_PAGE
)
913 max_objects
= MAX_OBJS_PER_PAGE
;
915 if (page
->objects
!= max_objects
) {
916 slab_err(s
, page
, "Wrong number of objects. Found %d but "
917 "should be %d", page
->objects
, max_objects
);
918 page
->objects
= max_objects
;
919 slab_fix(s
, "Number of objects adjusted.");
921 if (page
->inuse
!= page
->objects
- nr
) {
922 slab_err(s
, page
, "Wrong object count. Counter is %d but "
923 "counted were %d", page
->inuse
, page
->objects
- nr
);
924 page
->inuse
= page
->objects
- nr
;
925 slab_fix(s
, "Object count adjusted.");
927 return search
== NULL
;
930 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
,
933 if (s
->flags
& SLAB_TRACE
) {
934 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
936 alloc
? "alloc" : "free",
941 print_section("Object ", (void *)object
,
949 * Hooks for other subsystems that check memory allocations. In a typical
950 * production configuration these hooks all should produce no code at all.
952 static inline void kmalloc_large_node_hook(void *ptr
, size_t size
, gfp_t flags
)
954 kmemleak_alloc(ptr
, size
, 1, flags
);
957 static inline void kfree_hook(const void *x
)
962 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
964 flags
&= gfp_allowed_mask
;
965 lockdep_trace_alloc(flags
);
966 might_sleep_if(flags
& __GFP_WAIT
);
968 return should_failslab(s
->object_size
, flags
, s
->flags
);
971 static inline void slab_post_alloc_hook(struct kmem_cache
*s
,
972 gfp_t flags
, void *object
)
974 flags
&= gfp_allowed_mask
;
975 kmemcheck_slab_alloc(s
, flags
, object
, slab_ksize(s
));
976 kmemleak_alloc_recursive(object
, s
->object_size
, 1, s
->flags
, flags
);
979 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
)
981 kmemleak_free_recursive(x
, s
->flags
);
984 * Trouble is that we may no longer disable interrupts in the fast path
985 * So in order to make the debug calls that expect irqs to be
986 * disabled we need to disable interrupts temporarily.
988 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
992 local_irq_save(flags
);
993 kmemcheck_slab_free(s
, x
, s
->object_size
);
994 debug_check_no_locks_freed(x
, s
->object_size
);
995 local_irq_restore(flags
);
998 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
999 debug_check_no_obj_freed(x
, s
->object_size
);
1003 * Tracking of fully allocated slabs for debugging purposes.
1005 static void add_full(struct kmem_cache
*s
,
1006 struct kmem_cache_node
*n
, struct page
*page
)
1008 if (!(s
->flags
& SLAB_STORE_USER
))
1011 lockdep_assert_held(&n
->list_lock
);
1012 list_add(&page
->lru
, &n
->full
);
1015 static void remove_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
, struct page
*page
)
1017 if (!(s
->flags
& SLAB_STORE_USER
))
1020 lockdep_assert_held(&n
->list_lock
);
1021 list_del(&page
->lru
);
1024 /* Tracking of the number of slabs for debugging purposes */
1025 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1027 struct kmem_cache_node
*n
= get_node(s
, node
);
1029 return atomic_long_read(&n
->nr_slabs
);
1032 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1034 return atomic_long_read(&n
->nr_slabs
);
1037 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1039 struct kmem_cache_node
*n
= get_node(s
, node
);
1042 * May be called early in order to allocate a slab for the
1043 * kmem_cache_node structure. Solve the chicken-egg
1044 * dilemma by deferring the increment of the count during
1045 * bootstrap (see early_kmem_cache_node_alloc).
1048 atomic_long_inc(&n
->nr_slabs
);
1049 atomic_long_add(objects
, &n
->total_objects
);
1052 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1054 struct kmem_cache_node
*n
= get_node(s
, node
);
1056 atomic_long_dec(&n
->nr_slabs
);
1057 atomic_long_sub(objects
, &n
->total_objects
);
1060 /* Object debug checks for alloc/free paths */
1061 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
1064 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
1067 init_object(s
, object
, SLUB_RED_INACTIVE
);
1068 init_tracking(s
, object
);
1071 static noinline
int alloc_debug_processing(struct kmem_cache
*s
,
1073 void *object
, unsigned long addr
)
1075 if (!check_slab(s
, page
))
1078 if (!check_valid_pointer(s
, page
, object
)) {
1079 object_err(s
, page
, object
, "Freelist Pointer check fails");
1083 if (!check_object(s
, page
, object
, SLUB_RED_INACTIVE
))
1086 /* Success perform special debug activities for allocs */
1087 if (s
->flags
& SLAB_STORE_USER
)
1088 set_track(s
, object
, TRACK_ALLOC
, addr
);
1089 trace(s
, page
, object
, 1);
1090 init_object(s
, object
, SLUB_RED_ACTIVE
);
1094 if (PageSlab(page
)) {
1096 * If this is a slab page then lets do the best we can
1097 * to avoid issues in the future. Marking all objects
1098 * as used avoids touching the remaining objects.
1100 slab_fix(s
, "Marking all objects used");
1101 page
->inuse
= page
->objects
;
1102 page
->freelist
= NULL
;
1107 static noinline
struct kmem_cache_node
*free_debug_processing(
1108 struct kmem_cache
*s
, struct page
*page
, void *object
,
1109 unsigned long addr
, unsigned long *flags
)
1111 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1113 spin_lock_irqsave(&n
->list_lock
, *flags
);
1116 if (!check_slab(s
, page
))
1119 if (!check_valid_pointer(s
, page
, object
)) {
1120 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
1124 if (on_freelist(s
, page
, object
)) {
1125 object_err(s
, page
, object
, "Object already free");
1129 if (!check_object(s
, page
, object
, SLUB_RED_ACTIVE
))
1132 if (unlikely(s
!= page
->slab_cache
)) {
1133 if (!PageSlab(page
)) {
1134 slab_err(s
, page
, "Attempt to free object(0x%p) "
1135 "outside of slab", object
);
1136 } else if (!page
->slab_cache
) {
1138 "SLUB <none>: no slab for object 0x%p.\n",
1142 object_err(s
, page
, object
,
1143 "page slab pointer corrupt.");
1147 if (s
->flags
& SLAB_STORE_USER
)
1148 set_track(s
, object
, TRACK_FREE
, addr
);
1149 trace(s
, page
, object
, 0);
1150 init_object(s
, object
, SLUB_RED_INACTIVE
);
1154 * Keep node_lock to preserve integrity
1155 * until the object is actually freed
1161 spin_unlock_irqrestore(&n
->list_lock
, *flags
);
1162 slab_fix(s
, "Object at 0x%p not freed", object
);
1166 static int __init
setup_slub_debug(char *str
)
1168 slub_debug
= DEBUG_DEFAULT_FLAGS
;
1169 if (*str
++ != '=' || !*str
)
1171 * No options specified. Switch on full debugging.
1177 * No options but restriction on slabs. This means full
1178 * debugging for slabs matching a pattern.
1182 if (tolower(*str
) == 'o') {
1184 * Avoid enabling debugging on caches if its minimum order
1185 * would increase as a result.
1187 disable_higher_order_debug
= 1;
1194 * Switch off all debugging measures.
1199 * Determine which debug features should be switched on
1201 for (; *str
&& *str
!= ','; str
++) {
1202 switch (tolower(*str
)) {
1204 slub_debug
|= SLAB_DEBUG_FREE
;
1207 slub_debug
|= SLAB_RED_ZONE
;
1210 slub_debug
|= SLAB_POISON
;
1213 slub_debug
|= SLAB_STORE_USER
;
1216 slub_debug
|= SLAB_TRACE
;
1219 slub_debug
|= SLAB_FAILSLAB
;
1222 printk(KERN_ERR
"slub_debug option '%c' "
1223 "unknown. skipped\n", *str
);
1229 slub_debug_slabs
= str
+ 1;
1234 __setup("slub_debug", setup_slub_debug
);
1236 static unsigned long kmem_cache_flags(unsigned long object_size
,
1237 unsigned long flags
, const char *name
,
1238 void (*ctor
)(void *))
1241 * Enable debugging if selected on the kernel commandline.
1243 if (slub_debug
&& (!slub_debug_slabs
|| (name
&&
1244 !strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
)))))
1245 flags
|= slub_debug
;
1250 static inline void setup_object_debug(struct kmem_cache
*s
,
1251 struct page
*page
, void *object
) {}
1253 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1254 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1256 static inline struct kmem_cache_node
*free_debug_processing(
1257 struct kmem_cache
*s
, struct page
*page
, void *object
,
1258 unsigned long addr
, unsigned long *flags
) { return NULL
; }
1260 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1262 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1263 void *object
, u8 val
) { return 1; }
1264 static inline void add_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1265 struct page
*page
) {}
1266 static inline void remove_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1267 struct page
*page
) {}
1268 static inline unsigned long kmem_cache_flags(unsigned long object_size
,
1269 unsigned long flags
, const char *name
,
1270 void (*ctor
)(void *))
1274 #define slub_debug 0
1276 #define disable_higher_order_debug 0
1278 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1280 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1282 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1284 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1287 static inline void kmalloc_large_node_hook(void *ptr
, size_t size
, gfp_t flags
)
1289 kmemleak_alloc(ptr
, size
, 1, flags
);
1292 static inline void kfree_hook(const void *x
)
1297 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
1300 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
,
1303 kmemleak_alloc_recursive(object
, s
->object_size
, 1, s
->flags
,
1304 flags
& gfp_allowed_mask
);
1307 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
)
1309 kmemleak_free_recursive(x
, s
->flags
);
1312 #endif /* CONFIG_SLUB_DEBUG */
1315 * Slab allocation and freeing
1317 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1318 struct kmem_cache_order_objects oo
)
1320 int order
= oo_order(oo
);
1322 flags
|= __GFP_NOTRACK
;
1324 if (node
== NUMA_NO_NODE
)
1325 return alloc_pages(flags
, order
);
1327 return alloc_pages_exact_node(node
, flags
, order
);
1330 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1333 struct kmem_cache_order_objects oo
= s
->oo
;
1336 flags
&= gfp_allowed_mask
;
1338 if (flags
& __GFP_WAIT
)
1341 flags
|= s
->allocflags
;
1344 * Let the initial higher-order allocation fail under memory pressure
1345 * so we fall-back to the minimum order allocation.
1347 alloc_gfp
= (flags
| __GFP_NOWARN
| __GFP_NORETRY
) & ~__GFP_NOFAIL
;
1349 page
= alloc_slab_page(alloc_gfp
, node
, oo
);
1350 if (unlikely(!page
)) {
1354 * Allocation may have failed due to fragmentation.
1355 * Try a lower order alloc if possible
1357 page
= alloc_slab_page(alloc_gfp
, node
, oo
);
1360 stat(s
, ORDER_FALLBACK
);
1363 if (kmemcheck_enabled
&& page
1364 && !(s
->flags
& (SLAB_NOTRACK
| DEBUG_DEFAULT_FLAGS
))) {
1365 int pages
= 1 << oo_order(oo
);
1367 kmemcheck_alloc_shadow(page
, oo_order(oo
), alloc_gfp
, node
);
1370 * Objects from caches that have a constructor don't get
1371 * cleared when they're allocated, so we need to do it here.
1374 kmemcheck_mark_uninitialized_pages(page
, pages
);
1376 kmemcheck_mark_unallocated_pages(page
, pages
);
1379 if (flags
& __GFP_WAIT
)
1380 local_irq_disable();
1384 page
->objects
= oo_objects(oo
);
1385 mod_zone_page_state(page_zone(page
),
1386 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1387 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1393 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1396 setup_object_debug(s
, page
, object
);
1397 if (unlikely(s
->ctor
))
1401 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1409 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1411 page
= allocate_slab(s
,
1412 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1416 order
= compound_order(page
);
1417 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1418 memcg_bind_pages(s
, order
);
1419 page
->slab_cache
= s
;
1420 __SetPageSlab(page
);
1421 if (page
->pfmemalloc
)
1422 SetPageSlabPfmemalloc(page
);
1424 start
= page_address(page
);
1426 if (unlikely(s
->flags
& SLAB_POISON
))
1427 memset(start
, POISON_INUSE
, PAGE_SIZE
<< order
);
1430 for_each_object(p
, s
, start
, page
->objects
) {
1431 setup_object(s
, page
, last
);
1432 set_freepointer(s
, last
, p
);
1435 setup_object(s
, page
, last
);
1436 set_freepointer(s
, last
, NULL
);
1438 page
->freelist
= start
;
1439 page
->inuse
= page
->objects
;
1445 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1447 int order
= compound_order(page
);
1448 int pages
= 1 << order
;
1450 if (kmem_cache_debug(s
)) {
1453 slab_pad_check(s
, page
);
1454 for_each_object(p
, s
, page_address(page
),
1456 check_object(s
, page
, p
, SLUB_RED_INACTIVE
);
1459 kmemcheck_free_shadow(page
, compound_order(page
));
1461 mod_zone_page_state(page_zone(page
),
1462 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1463 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1466 __ClearPageSlabPfmemalloc(page
);
1467 __ClearPageSlab(page
);
1469 memcg_release_pages(s
, order
);
1470 page_mapcount_reset(page
);
1471 if (current
->reclaim_state
)
1472 current
->reclaim_state
->reclaimed_slab
+= pages
;
1473 __free_memcg_kmem_pages(page
, order
);
1476 #define need_reserve_slab_rcu \
1477 (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
1479 static void rcu_free_slab(struct rcu_head
*h
)
1483 if (need_reserve_slab_rcu
)
1484 page
= virt_to_head_page(h
);
1486 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1488 __free_slab(page
->slab_cache
, page
);
1491 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1493 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1494 struct rcu_head
*head
;
1496 if (need_reserve_slab_rcu
) {
1497 int order
= compound_order(page
);
1498 int offset
= (PAGE_SIZE
<< order
) - s
->reserved
;
1500 VM_BUG_ON(s
->reserved
!= sizeof(*head
));
1501 head
= page_address(page
) + offset
;
1504 * RCU free overloads the RCU head over the LRU
1506 head
= (void *)&page
->lru
;
1509 call_rcu(head
, rcu_free_slab
);
1511 __free_slab(s
, page
);
1514 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1516 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1521 * Management of partially allocated slabs.
1524 __add_partial(struct kmem_cache_node
*n
, struct page
*page
, int tail
)
1527 if (tail
== DEACTIVATE_TO_TAIL
)
1528 list_add_tail(&page
->lru
, &n
->partial
);
1530 list_add(&page
->lru
, &n
->partial
);
1533 static inline void add_partial(struct kmem_cache_node
*n
,
1534 struct page
*page
, int tail
)
1536 lockdep_assert_held(&n
->list_lock
);
1537 __add_partial(n
, page
, tail
);
1541 __remove_partial(struct kmem_cache_node
*n
, struct page
*page
)
1543 list_del(&page
->lru
);
1547 static inline void remove_partial(struct kmem_cache_node
*n
,
1550 lockdep_assert_held(&n
->list_lock
);
1551 __remove_partial(n
, page
);
1555 * Remove slab from the partial list, freeze it and
1556 * return the pointer to the freelist.
1558 * Returns a list of objects or NULL if it fails.
1560 static inline void *acquire_slab(struct kmem_cache
*s
,
1561 struct kmem_cache_node
*n
, struct page
*page
,
1562 int mode
, int *objects
)
1565 unsigned long counters
;
1568 lockdep_assert_held(&n
->list_lock
);
1571 * Zap the freelist and set the frozen bit.
1572 * The old freelist is the list of objects for the
1573 * per cpu allocation list.
1575 freelist
= page
->freelist
;
1576 counters
= page
->counters
;
1577 new.counters
= counters
;
1578 *objects
= new.objects
- new.inuse
;
1580 new.inuse
= page
->objects
;
1581 new.freelist
= NULL
;
1583 new.freelist
= freelist
;
1586 VM_BUG_ON(new.frozen
);
1589 if (!__cmpxchg_double_slab(s
, page
,
1591 new.freelist
, new.counters
,
1595 remove_partial(n
, page
);
1600 static void put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
);
1601 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
);
1604 * Try to allocate a partial slab from a specific node.
1606 static void *get_partial_node(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1607 struct kmem_cache_cpu
*c
, gfp_t flags
)
1609 struct page
*page
, *page2
;
1610 void *object
= NULL
;
1615 * Racy check. If we mistakenly see no partial slabs then we
1616 * just allocate an empty slab. If we mistakenly try to get a
1617 * partial slab and there is none available then get_partials()
1620 if (!n
|| !n
->nr_partial
)
1623 spin_lock(&n
->list_lock
);
1624 list_for_each_entry_safe(page
, page2
, &n
->partial
, lru
) {
1627 if (!pfmemalloc_match(page
, flags
))
1630 t
= acquire_slab(s
, n
, page
, object
== NULL
, &objects
);
1634 available
+= objects
;
1637 stat(s
, ALLOC_FROM_PARTIAL
);
1640 put_cpu_partial(s
, page
, 0);
1641 stat(s
, CPU_PARTIAL_NODE
);
1643 if (!kmem_cache_has_cpu_partial(s
)
1644 || available
> s
->cpu_partial
/ 2)
1648 spin_unlock(&n
->list_lock
);
1653 * Get a page from somewhere. Search in increasing NUMA distances.
1655 static void *get_any_partial(struct kmem_cache
*s
, gfp_t flags
,
1656 struct kmem_cache_cpu
*c
)
1659 struct zonelist
*zonelist
;
1662 enum zone_type high_zoneidx
= gfp_zone(flags
);
1664 unsigned int cpuset_mems_cookie
;
1667 * The defrag ratio allows a configuration of the tradeoffs between
1668 * inter node defragmentation and node local allocations. A lower
1669 * defrag_ratio increases the tendency to do local allocations
1670 * instead of attempting to obtain partial slabs from other nodes.
1672 * If the defrag_ratio is set to 0 then kmalloc() always
1673 * returns node local objects. If the ratio is higher then kmalloc()
1674 * may return off node objects because partial slabs are obtained
1675 * from other nodes and filled up.
1677 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1678 * defrag_ratio = 1000) then every (well almost) allocation will
1679 * first attempt to defrag slab caches on other nodes. This means
1680 * scanning over all nodes to look for partial slabs which may be
1681 * expensive if we do it every time we are trying to find a slab
1682 * with available objects.
1684 if (!s
->remote_node_defrag_ratio
||
1685 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1689 cpuset_mems_cookie
= read_mems_allowed_begin();
1690 zonelist
= node_zonelist(mempolicy_slab_node(), flags
);
1691 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
1692 struct kmem_cache_node
*n
;
1694 n
= get_node(s
, zone_to_nid(zone
));
1696 if (n
&& cpuset_zone_allowed_hardwall(zone
, flags
) &&
1697 n
->nr_partial
> s
->min_partial
) {
1698 object
= get_partial_node(s
, n
, c
, flags
);
1701 * Don't check read_mems_allowed_retry()
1702 * here - if mems_allowed was updated in
1703 * parallel, that was a harmless race
1704 * between allocation and the cpuset
1711 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
1717 * Get a partial page, lock it and return it.
1719 static void *get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
,
1720 struct kmem_cache_cpu
*c
)
1723 int searchnode
= (node
== NUMA_NO_NODE
) ? numa_node_id() : node
;
1725 object
= get_partial_node(s
, get_node(s
, searchnode
), c
, flags
);
1726 if (object
|| node
!= NUMA_NO_NODE
)
1729 return get_any_partial(s
, flags
, c
);
1732 #ifdef CONFIG_PREEMPT
1734 * Calculate the next globally unique transaction for disambiguiation
1735 * during cmpxchg. The transactions start with the cpu number and are then
1736 * incremented by CONFIG_NR_CPUS.
1738 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1741 * No preemption supported therefore also no need to check for
1747 static inline unsigned long next_tid(unsigned long tid
)
1749 return tid
+ TID_STEP
;
1752 static inline unsigned int tid_to_cpu(unsigned long tid
)
1754 return tid
% TID_STEP
;
1757 static inline unsigned long tid_to_event(unsigned long tid
)
1759 return tid
/ TID_STEP
;
1762 static inline unsigned int init_tid(int cpu
)
1767 static inline void note_cmpxchg_failure(const char *n
,
1768 const struct kmem_cache
*s
, unsigned long tid
)
1770 #ifdef SLUB_DEBUG_CMPXCHG
1771 unsigned long actual_tid
= __this_cpu_read(s
->cpu_slab
->tid
);
1773 printk(KERN_INFO
"%s %s: cmpxchg redo ", n
, s
->name
);
1775 #ifdef CONFIG_PREEMPT
1776 if (tid_to_cpu(tid
) != tid_to_cpu(actual_tid
))
1777 printk("due to cpu change %d -> %d\n",
1778 tid_to_cpu(tid
), tid_to_cpu(actual_tid
));
1781 if (tid_to_event(tid
) != tid_to_event(actual_tid
))
1782 printk("due to cpu running other code. Event %ld->%ld\n",
1783 tid_to_event(tid
), tid_to_event(actual_tid
));
1785 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1786 actual_tid
, tid
, next_tid(tid
));
1788 stat(s
, CMPXCHG_DOUBLE_CPU_FAIL
);
1791 static void init_kmem_cache_cpus(struct kmem_cache
*s
)
1795 for_each_possible_cpu(cpu
)
1796 per_cpu_ptr(s
->cpu_slab
, cpu
)->tid
= init_tid(cpu
);
1800 * Remove the cpu slab
1802 static void deactivate_slab(struct kmem_cache
*s
, struct page
*page
,
1805 enum slab_modes
{ M_NONE
, M_PARTIAL
, M_FULL
, M_FREE
};
1806 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1808 enum slab_modes l
= M_NONE
, m
= M_NONE
;
1810 int tail
= DEACTIVATE_TO_HEAD
;
1814 if (page
->freelist
) {
1815 stat(s
, DEACTIVATE_REMOTE_FREES
);
1816 tail
= DEACTIVATE_TO_TAIL
;
1820 * Stage one: Free all available per cpu objects back
1821 * to the page freelist while it is still frozen. Leave the
1824 * There is no need to take the list->lock because the page
1827 while (freelist
&& (nextfree
= get_freepointer(s
, freelist
))) {
1829 unsigned long counters
;
1832 prior
= page
->freelist
;
1833 counters
= page
->counters
;
1834 set_freepointer(s
, freelist
, prior
);
1835 new.counters
= counters
;
1837 VM_BUG_ON(!new.frozen
);
1839 } while (!__cmpxchg_double_slab(s
, page
,
1841 freelist
, new.counters
,
1842 "drain percpu freelist"));
1844 freelist
= nextfree
;
1848 * Stage two: Ensure that the page is unfrozen while the
1849 * list presence reflects the actual number of objects
1852 * We setup the list membership and then perform a cmpxchg
1853 * with the count. If there is a mismatch then the page
1854 * is not unfrozen but the page is on the wrong list.
1856 * Then we restart the process which may have to remove
1857 * the page from the list that we just put it on again
1858 * because the number of objects in the slab may have
1863 old
.freelist
= page
->freelist
;
1864 old
.counters
= page
->counters
;
1865 VM_BUG_ON(!old
.frozen
);
1867 /* Determine target state of the slab */
1868 new.counters
= old
.counters
;
1871 set_freepointer(s
, freelist
, old
.freelist
);
1872 new.freelist
= freelist
;
1874 new.freelist
= old
.freelist
;
1878 if (!new.inuse
&& n
->nr_partial
> s
->min_partial
)
1880 else if (new.freelist
) {
1885 * Taking the spinlock removes the possiblity
1886 * that acquire_slab() will see a slab page that
1889 spin_lock(&n
->list_lock
);
1893 if (kmem_cache_debug(s
) && !lock
) {
1896 * This also ensures that the scanning of full
1897 * slabs from diagnostic functions will not see
1900 spin_lock(&n
->list_lock
);
1908 remove_partial(n
, page
);
1910 else if (l
== M_FULL
)
1912 remove_full(s
, n
, page
);
1914 if (m
== M_PARTIAL
) {
1916 add_partial(n
, page
, tail
);
1919 } else if (m
== M_FULL
) {
1921 stat(s
, DEACTIVATE_FULL
);
1922 add_full(s
, n
, page
);
1928 if (!__cmpxchg_double_slab(s
, page
,
1929 old
.freelist
, old
.counters
,
1930 new.freelist
, new.counters
,
1935 spin_unlock(&n
->list_lock
);
1938 stat(s
, DEACTIVATE_EMPTY
);
1939 discard_slab(s
, page
);
1945 * Unfreeze all the cpu partial slabs.
1947 * This function must be called with interrupts disabled
1948 * for the cpu using c (or some other guarantee must be there
1949 * to guarantee no concurrent accesses).
1951 static void unfreeze_partials(struct kmem_cache
*s
,
1952 struct kmem_cache_cpu
*c
)
1954 #ifdef CONFIG_SLUB_CPU_PARTIAL
1955 struct kmem_cache_node
*n
= NULL
, *n2
= NULL
;
1956 struct page
*page
, *discard_page
= NULL
;
1958 while ((page
= c
->partial
)) {
1962 c
->partial
= page
->next
;
1964 n2
= get_node(s
, page_to_nid(page
));
1967 spin_unlock(&n
->list_lock
);
1970 spin_lock(&n
->list_lock
);
1975 old
.freelist
= page
->freelist
;
1976 old
.counters
= page
->counters
;
1977 VM_BUG_ON(!old
.frozen
);
1979 new.counters
= old
.counters
;
1980 new.freelist
= old
.freelist
;
1984 } while (!__cmpxchg_double_slab(s
, page
,
1985 old
.freelist
, old
.counters
,
1986 new.freelist
, new.counters
,
1987 "unfreezing slab"));
1989 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
)) {
1990 page
->next
= discard_page
;
1991 discard_page
= page
;
1993 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
1994 stat(s
, FREE_ADD_PARTIAL
);
1999 spin_unlock(&n
->list_lock
);
2001 while (discard_page
) {
2002 page
= discard_page
;
2003 discard_page
= discard_page
->next
;
2005 stat(s
, DEACTIVATE_EMPTY
);
2006 discard_slab(s
, page
);
2013 * Put a page that was just frozen (in __slab_free) into a partial page
2014 * slot if available. This is done without interrupts disabled and without
2015 * preemption disabled. The cmpxchg is racy and may put the partial page
2016 * onto a random cpus partial slot.
2018 * If we did not find a slot then simply move all the partials to the
2019 * per node partial list.
2021 static void put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
)
2023 #ifdef CONFIG_SLUB_CPU_PARTIAL
2024 struct page
*oldpage
;
2031 oldpage
= this_cpu_read(s
->cpu_slab
->partial
);
2034 pobjects
= oldpage
->pobjects
;
2035 pages
= oldpage
->pages
;
2036 if (drain
&& pobjects
> s
->cpu_partial
) {
2037 unsigned long flags
;
2039 * partial array is full. Move the existing
2040 * set to the per node partial list.
2042 local_irq_save(flags
);
2043 unfreeze_partials(s
, this_cpu_ptr(s
->cpu_slab
));
2044 local_irq_restore(flags
);
2048 stat(s
, CPU_PARTIAL_DRAIN
);
2053 pobjects
+= page
->objects
- page
->inuse
;
2055 page
->pages
= pages
;
2056 page
->pobjects
= pobjects
;
2057 page
->next
= oldpage
;
2059 } while (this_cpu_cmpxchg(s
->cpu_slab
->partial
, oldpage
, page
)
2064 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
2066 stat(s
, CPUSLAB_FLUSH
);
2067 deactivate_slab(s
, c
->page
, c
->freelist
);
2069 c
->tid
= next_tid(c
->tid
);
2077 * Called from IPI handler with interrupts disabled.
2079 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
2081 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2087 unfreeze_partials(s
, c
);
2091 static void flush_cpu_slab(void *d
)
2093 struct kmem_cache
*s
= d
;
2095 __flush_cpu_slab(s
, smp_processor_id());
2098 static bool has_cpu_slab(int cpu
, void *info
)
2100 struct kmem_cache
*s
= info
;
2101 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2103 return c
->page
|| c
->partial
;
2106 static void flush_all(struct kmem_cache
*s
)
2108 on_each_cpu_cond(has_cpu_slab
, flush_cpu_slab
, s
, 1, GFP_ATOMIC
);
2112 * Check if the objects in a per cpu structure fit numa
2113 * locality expectations.
2115 static inline int node_match(struct page
*page
, int node
)
2118 if (!page
|| (node
!= NUMA_NO_NODE
&& page_to_nid(page
) != node
))
2124 static int count_free(struct page
*page
)
2126 return page
->objects
- page
->inuse
;
2129 static unsigned long count_partial(struct kmem_cache_node
*n
,
2130 int (*get_count
)(struct page
*))
2132 unsigned long flags
;
2133 unsigned long x
= 0;
2136 spin_lock_irqsave(&n
->list_lock
, flags
);
2137 list_for_each_entry(page
, &n
->partial
, lru
)
2138 x
+= get_count(page
);
2139 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2143 static inline unsigned long node_nr_objs(struct kmem_cache_node
*n
)
2145 #ifdef CONFIG_SLUB_DEBUG
2146 return atomic_long_read(&n
->total_objects
);
2152 static noinline
void
2153 slab_out_of_memory(struct kmem_cache
*s
, gfp_t gfpflags
, int nid
)
2158 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
2160 printk(KERN_WARNING
" cache: %s, object size: %d, buffer size: %d, "
2161 "default order: %d, min order: %d\n", s
->name
, s
->object_size
,
2162 s
->size
, oo_order(s
->oo
), oo_order(s
->min
));
2164 if (oo_order(s
->min
) > get_order(s
->object_size
))
2165 printk(KERN_WARNING
" %s debugging increased min order, use "
2166 "slub_debug=O to disable.\n", s
->name
);
2168 for_each_online_node(node
) {
2169 struct kmem_cache_node
*n
= get_node(s
, node
);
2170 unsigned long nr_slabs
;
2171 unsigned long nr_objs
;
2172 unsigned long nr_free
;
2177 nr_free
= count_partial(n
, count_free
);
2178 nr_slabs
= node_nr_slabs(n
);
2179 nr_objs
= node_nr_objs(n
);
2182 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
2183 node
, nr_slabs
, nr_objs
, nr_free
);
2187 static inline void *new_slab_objects(struct kmem_cache
*s
, gfp_t flags
,
2188 int node
, struct kmem_cache_cpu
**pc
)
2191 struct kmem_cache_cpu
*c
= *pc
;
2194 freelist
= get_partial(s
, flags
, node
, c
);
2199 page
= new_slab(s
, flags
, node
);
2201 c
= __this_cpu_ptr(s
->cpu_slab
);
2206 * No other reference to the page yet so we can
2207 * muck around with it freely without cmpxchg
2209 freelist
= page
->freelist
;
2210 page
->freelist
= NULL
;
2212 stat(s
, ALLOC_SLAB
);
2221 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
)
2223 if (unlikely(PageSlabPfmemalloc(page
)))
2224 return gfp_pfmemalloc_allowed(gfpflags
);
2230 * Check the page->freelist of a page and either transfer the freelist to the
2231 * per cpu freelist or deactivate the page.
2233 * The page is still frozen if the return value is not NULL.
2235 * If this function returns NULL then the page has been unfrozen.
2237 * This function must be called with interrupt disabled.
2239 static inline void *get_freelist(struct kmem_cache
*s
, struct page
*page
)
2242 unsigned long counters
;
2246 freelist
= page
->freelist
;
2247 counters
= page
->counters
;
2249 new.counters
= counters
;
2250 VM_BUG_ON(!new.frozen
);
2252 new.inuse
= page
->objects
;
2253 new.frozen
= freelist
!= NULL
;
2255 } while (!__cmpxchg_double_slab(s
, page
,
2264 * Slow path. The lockless freelist is empty or we need to perform
2267 * Processing is still very fast if new objects have been freed to the
2268 * regular freelist. In that case we simply take over the regular freelist
2269 * as the lockless freelist and zap the regular freelist.
2271 * If that is not working then we fall back to the partial lists. We take the
2272 * first element of the freelist as the object to allocate now and move the
2273 * rest of the freelist to the lockless freelist.
2275 * And if we were unable to get a new slab from the partial slab lists then
2276 * we need to allocate a new slab. This is the slowest path since it involves
2277 * a call to the page allocator and the setup of a new slab.
2279 static void *__slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, int node
,
2280 unsigned long addr
, struct kmem_cache_cpu
*c
)
2284 unsigned long flags
;
2286 local_irq_save(flags
);
2287 #ifdef CONFIG_PREEMPT
2289 * We may have been preempted and rescheduled on a different
2290 * cpu before disabling interrupts. Need to reload cpu area
2293 c
= this_cpu_ptr(s
->cpu_slab
);
2301 if (unlikely(!node_match(page
, node
))) {
2302 stat(s
, ALLOC_NODE_MISMATCH
);
2303 deactivate_slab(s
, page
, c
->freelist
);
2310 * By rights, we should be searching for a slab page that was
2311 * PFMEMALLOC but right now, we are losing the pfmemalloc
2312 * information when the page leaves the per-cpu allocator
2314 if (unlikely(!pfmemalloc_match(page
, gfpflags
))) {
2315 deactivate_slab(s
, page
, c
->freelist
);
2321 /* must check again c->freelist in case of cpu migration or IRQ */
2322 freelist
= c
->freelist
;
2326 stat(s
, ALLOC_SLOWPATH
);
2328 freelist
= get_freelist(s
, page
);
2332 stat(s
, DEACTIVATE_BYPASS
);
2336 stat(s
, ALLOC_REFILL
);
2340 * freelist is pointing to the list of objects to be used.
2341 * page is pointing to the page from which the objects are obtained.
2342 * That page must be frozen for per cpu allocations to work.
2344 VM_BUG_ON(!c
->page
->frozen
);
2345 c
->freelist
= get_freepointer(s
, freelist
);
2346 c
->tid
= next_tid(c
->tid
);
2347 local_irq_restore(flags
);
2353 page
= c
->page
= c
->partial
;
2354 c
->partial
= page
->next
;
2355 stat(s
, CPU_PARTIAL_ALLOC
);
2360 freelist
= new_slab_objects(s
, gfpflags
, node
, &c
);
2362 if (unlikely(!freelist
)) {
2363 if (!(gfpflags
& __GFP_NOWARN
) && printk_ratelimit())
2364 slab_out_of_memory(s
, gfpflags
, node
);
2366 local_irq_restore(flags
);
2371 if (likely(!kmem_cache_debug(s
) && pfmemalloc_match(page
, gfpflags
)))
2374 /* Only entered in the debug case */
2375 if (kmem_cache_debug(s
) &&
2376 !alloc_debug_processing(s
, page
, freelist
, addr
))
2377 goto new_slab
; /* Slab failed checks. Next slab needed */
2379 deactivate_slab(s
, page
, get_freepointer(s
, freelist
));
2382 local_irq_restore(flags
);
2387 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
2388 * have the fastpath folded into their functions. So no function call
2389 * overhead for requests that can be satisfied on the fastpath.
2391 * The fastpath works by first checking if the lockless freelist can be used.
2392 * If not then __slab_alloc is called for slow processing.
2394 * Otherwise we can simply pick the next object from the lockless free list.
2396 static __always_inline
void *slab_alloc_node(struct kmem_cache
*s
,
2397 gfp_t gfpflags
, int node
, unsigned long addr
)
2400 struct kmem_cache_cpu
*c
;
2404 if (slab_pre_alloc_hook(s
, gfpflags
))
2407 s
= memcg_kmem_get_cache(s
, gfpflags
);
2410 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
2411 * enabled. We may switch back and forth between cpus while
2412 * reading from one cpu area. That does not matter as long
2413 * as we end up on the original cpu again when doing the cmpxchg.
2415 * Preemption is disabled for the retrieval of the tid because that
2416 * must occur from the current processor. We cannot allow rescheduling
2417 * on a different processor between the determination of the pointer
2418 * and the retrieval of the tid.
2421 c
= __this_cpu_ptr(s
->cpu_slab
);
2424 * The transaction ids are globally unique per cpu and per operation on
2425 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
2426 * occurs on the right processor and that there was no operation on the
2427 * linked list in between.
2432 object
= c
->freelist
;
2434 if (unlikely(!object
|| !node_match(page
, node
)))
2435 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
2438 void *next_object
= get_freepointer_safe(s
, object
);
2441 * The cmpxchg will only match if there was no additional
2442 * operation and if we are on the right processor.
2444 * The cmpxchg does the following atomically (without lock
2446 * 1. Relocate first pointer to the current per cpu area.
2447 * 2. Verify that tid and freelist have not been changed
2448 * 3. If they were not changed replace tid and freelist
2450 * Since this is without lock semantics the protection is only
2451 * against code executing on this cpu *not* from access by
2454 if (unlikely(!this_cpu_cmpxchg_double(
2455 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2457 next_object
, next_tid(tid
)))) {
2459 note_cmpxchg_failure("slab_alloc", s
, tid
);
2462 prefetch_freepointer(s
, next_object
);
2463 stat(s
, ALLOC_FASTPATH
);
2466 if (unlikely(gfpflags
& __GFP_ZERO
) && object
)
2467 memset(object
, 0, s
->object_size
);
2469 slab_post_alloc_hook(s
, gfpflags
, object
);
2474 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
2475 gfp_t gfpflags
, unsigned long addr
)
2477 return slab_alloc_node(s
, gfpflags
, NUMA_NO_NODE
, addr
);
2480 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
2482 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2484 trace_kmem_cache_alloc(_RET_IP_
, ret
, s
->object_size
,
2489 EXPORT_SYMBOL(kmem_cache_alloc
);
2491 #ifdef CONFIG_TRACING
2492 void *kmem_cache_alloc_trace(struct kmem_cache
*s
, gfp_t gfpflags
, size_t size
)
2494 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2495 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, gfpflags
);
2498 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
2502 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
2504 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2506 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
2507 s
->object_size
, s
->size
, gfpflags
, node
);
2511 EXPORT_SYMBOL(kmem_cache_alloc_node
);
2513 #ifdef CONFIG_TRACING
2514 void *kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
2516 int node
, size_t size
)
2518 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2520 trace_kmalloc_node(_RET_IP_
, ret
,
2521 size
, s
->size
, gfpflags
, node
);
2524 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
2529 * Slow patch handling. This may still be called frequently since objects
2530 * have a longer lifetime than the cpu slabs in most processing loads.
2532 * So we still attempt to reduce cache line usage. Just take the slab
2533 * lock and free the item. If there is no additional partial page
2534 * handling required then we can return immediately.
2536 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
2537 void *x
, unsigned long addr
)
2540 void **object
= (void *)x
;
2543 unsigned long counters
;
2544 struct kmem_cache_node
*n
= NULL
;
2545 unsigned long uninitialized_var(flags
);
2547 stat(s
, FREE_SLOWPATH
);
2549 if (kmem_cache_debug(s
) &&
2550 !(n
= free_debug_processing(s
, page
, x
, addr
, &flags
)))
2555 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2558 prior
= page
->freelist
;
2559 counters
= page
->counters
;
2560 set_freepointer(s
, object
, prior
);
2561 new.counters
= counters
;
2562 was_frozen
= new.frozen
;
2564 if ((!new.inuse
|| !prior
) && !was_frozen
) {
2566 if (kmem_cache_has_cpu_partial(s
) && !prior
) {
2569 * Slab was on no list before and will be
2571 * We can defer the list move and instead
2576 } else { /* Needs to be taken off a list */
2578 n
= get_node(s
, page_to_nid(page
));
2580 * Speculatively acquire the list_lock.
2581 * If the cmpxchg does not succeed then we may
2582 * drop the list_lock without any processing.
2584 * Otherwise the list_lock will synchronize with
2585 * other processors updating the list of slabs.
2587 spin_lock_irqsave(&n
->list_lock
, flags
);
2592 } while (!cmpxchg_double_slab(s
, page
,
2594 object
, new.counters
,
2600 * If we just froze the page then put it onto the
2601 * per cpu partial list.
2603 if (new.frozen
&& !was_frozen
) {
2604 put_cpu_partial(s
, page
, 1);
2605 stat(s
, CPU_PARTIAL_FREE
);
2608 * The list lock was not taken therefore no list
2609 * activity can be necessary.
2612 stat(s
, FREE_FROZEN
);
2616 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
))
2620 * Objects left in the slab. If it was not on the partial list before
2623 if (!kmem_cache_has_cpu_partial(s
) && unlikely(!prior
)) {
2624 if (kmem_cache_debug(s
))
2625 remove_full(s
, n
, page
);
2626 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
2627 stat(s
, FREE_ADD_PARTIAL
);
2629 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2635 * Slab on the partial list.
2637 remove_partial(n
, page
);
2638 stat(s
, FREE_REMOVE_PARTIAL
);
2640 /* Slab must be on the full list */
2641 remove_full(s
, n
, page
);
2644 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2646 discard_slab(s
, page
);
2650 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2651 * can perform fastpath freeing without additional function calls.
2653 * The fastpath is only possible if we are freeing to the current cpu slab
2654 * of this processor. This typically the case if we have just allocated
2657 * If fastpath is not possible then fall back to __slab_free where we deal
2658 * with all sorts of special processing.
2660 static __always_inline
void slab_free(struct kmem_cache
*s
,
2661 struct page
*page
, void *x
, unsigned long addr
)
2663 void **object
= (void *)x
;
2664 struct kmem_cache_cpu
*c
;
2667 slab_free_hook(s
, x
);
2671 * Determine the currently cpus per cpu slab.
2672 * The cpu may change afterward. However that does not matter since
2673 * data is retrieved via this pointer. If we are on the same cpu
2674 * during the cmpxchg then the free will succedd.
2677 c
= __this_cpu_ptr(s
->cpu_slab
);
2682 if (likely(page
== c
->page
)) {
2683 set_freepointer(s
, object
, c
->freelist
);
2685 if (unlikely(!this_cpu_cmpxchg_double(
2686 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2688 object
, next_tid(tid
)))) {
2690 note_cmpxchg_failure("slab_free", s
, tid
);
2693 stat(s
, FREE_FASTPATH
);
2695 __slab_free(s
, page
, x
, addr
);
2699 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
2701 s
= cache_from_obj(s
, x
);
2704 slab_free(s
, virt_to_head_page(x
), x
, _RET_IP_
);
2705 trace_kmem_cache_free(_RET_IP_
, x
);
2707 EXPORT_SYMBOL(kmem_cache_free
);
2710 * Object placement in a slab is made very easy because we always start at
2711 * offset 0. If we tune the size of the object to the alignment then we can
2712 * get the required alignment by putting one properly sized object after
2715 * Notice that the allocation order determines the sizes of the per cpu
2716 * caches. Each processor has always one slab available for allocations.
2717 * Increasing the allocation order reduces the number of times that slabs
2718 * must be moved on and off the partial lists and is therefore a factor in
2723 * Mininum / Maximum order of slab pages. This influences locking overhead
2724 * and slab fragmentation. A higher order reduces the number of partial slabs
2725 * and increases the number of allocations possible without having to
2726 * take the list_lock.
2728 static int slub_min_order
;
2729 static int slub_max_order
= PAGE_ALLOC_COSTLY_ORDER
;
2730 static int slub_min_objects
;
2733 * Merge control. If this is set then no merging of slab caches will occur.
2734 * (Could be removed. This was introduced to pacify the merge skeptics.)
2736 static int slub_nomerge
;
2739 * Calculate the order of allocation given an slab object size.
2741 * The order of allocation has significant impact on performance and other
2742 * system components. Generally order 0 allocations should be preferred since
2743 * order 0 does not cause fragmentation in the page allocator. Larger objects
2744 * be problematic to put into order 0 slabs because there may be too much
2745 * unused space left. We go to a higher order if more than 1/16th of the slab
2748 * In order to reach satisfactory performance we must ensure that a minimum
2749 * number of objects is in one slab. Otherwise we may generate too much
2750 * activity on the partial lists which requires taking the list_lock. This is
2751 * less a concern for large slabs though which are rarely used.
2753 * slub_max_order specifies the order where we begin to stop considering the
2754 * number of objects in a slab as critical. If we reach slub_max_order then
2755 * we try to keep the page order as low as possible. So we accept more waste
2756 * of space in favor of a small page order.
2758 * Higher order allocations also allow the placement of more objects in a
2759 * slab and thereby reduce object handling overhead. If the user has
2760 * requested a higher mininum order then we start with that one instead of
2761 * the smallest order which will fit the object.
2763 static inline int slab_order(int size
, int min_objects
,
2764 int max_order
, int fract_leftover
, int reserved
)
2768 int min_order
= slub_min_order
;
2770 if (order_objects(min_order
, size
, reserved
) > MAX_OBJS_PER_PAGE
)
2771 return get_order(size
* MAX_OBJS_PER_PAGE
) - 1;
2773 for (order
= max(min_order
,
2774 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
2775 order
<= max_order
; order
++) {
2777 unsigned long slab_size
= PAGE_SIZE
<< order
;
2779 if (slab_size
< min_objects
* size
+ reserved
)
2782 rem
= (slab_size
- reserved
) % size
;
2784 if (rem
<= slab_size
/ fract_leftover
)
2792 static inline int calculate_order(int size
, int reserved
)
2800 * Attempt to find best configuration for a slab. This
2801 * works by first attempting to generate a layout with
2802 * the best configuration and backing off gradually.
2804 * First we reduce the acceptable waste in a slab. Then
2805 * we reduce the minimum objects required in a slab.
2807 min_objects
= slub_min_objects
;
2809 min_objects
= 4 * (fls(nr_cpu_ids
) + 1);
2810 max_objects
= order_objects(slub_max_order
, size
, reserved
);
2811 min_objects
= min(min_objects
, max_objects
);
2813 while (min_objects
> 1) {
2815 while (fraction
>= 4) {
2816 order
= slab_order(size
, min_objects
,
2817 slub_max_order
, fraction
, reserved
);
2818 if (order
<= slub_max_order
)
2826 * We were unable to place multiple objects in a slab. Now
2827 * lets see if we can place a single object there.
2829 order
= slab_order(size
, 1, slub_max_order
, 1, reserved
);
2830 if (order
<= slub_max_order
)
2834 * Doh this slab cannot be placed using slub_max_order.
2836 order
= slab_order(size
, 1, MAX_ORDER
, 1, reserved
);
2837 if (order
< MAX_ORDER
)
2843 init_kmem_cache_node(struct kmem_cache_node
*n
)
2846 spin_lock_init(&n
->list_lock
);
2847 INIT_LIST_HEAD(&n
->partial
);
2848 #ifdef CONFIG_SLUB_DEBUG
2849 atomic_long_set(&n
->nr_slabs
, 0);
2850 atomic_long_set(&n
->total_objects
, 0);
2851 INIT_LIST_HEAD(&n
->full
);
2855 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
)
2857 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE
<
2858 KMALLOC_SHIFT_HIGH
* sizeof(struct kmem_cache_cpu
));
2861 * Must align to double word boundary for the double cmpxchg
2862 * instructions to work; see __pcpu_double_call_return_bool().
2864 s
->cpu_slab
= __alloc_percpu(sizeof(struct kmem_cache_cpu
),
2865 2 * sizeof(void *));
2870 init_kmem_cache_cpus(s
);
2875 static struct kmem_cache
*kmem_cache_node
;
2878 * No kmalloc_node yet so do it by hand. We know that this is the first
2879 * slab on the node for this slabcache. There are no concurrent accesses
2882 * Note that this function only works on the kmem_cache_node
2883 * when allocating for the kmem_cache_node. This is used for bootstrapping
2884 * memory on a fresh node that has no slab structures yet.
2886 static void early_kmem_cache_node_alloc(int node
)
2889 struct kmem_cache_node
*n
;
2891 BUG_ON(kmem_cache_node
->size
< sizeof(struct kmem_cache_node
));
2893 page
= new_slab(kmem_cache_node
, GFP_NOWAIT
, node
);
2896 if (page_to_nid(page
) != node
) {
2897 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2899 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2900 "in order to be able to continue\n");
2905 page
->freelist
= get_freepointer(kmem_cache_node
, n
);
2908 kmem_cache_node
->node
[node
] = n
;
2909 #ifdef CONFIG_SLUB_DEBUG
2910 init_object(kmem_cache_node
, n
, SLUB_RED_ACTIVE
);
2911 init_tracking(kmem_cache_node
, n
);
2913 init_kmem_cache_node(n
);
2914 inc_slabs_node(kmem_cache_node
, node
, page
->objects
);
2917 * No locks need to be taken here as it has just been
2918 * initialized and there is no concurrent access.
2920 __add_partial(n
, page
, DEACTIVATE_TO_HEAD
);
2923 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2927 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2928 struct kmem_cache_node
*n
= s
->node
[node
];
2931 kmem_cache_free(kmem_cache_node
, n
);
2933 s
->node
[node
] = NULL
;
2937 static int init_kmem_cache_nodes(struct kmem_cache
*s
)
2941 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2942 struct kmem_cache_node
*n
;
2944 if (slab_state
== DOWN
) {
2945 early_kmem_cache_node_alloc(node
);
2948 n
= kmem_cache_alloc_node(kmem_cache_node
,
2952 free_kmem_cache_nodes(s
);
2957 init_kmem_cache_node(n
);
2962 static void set_min_partial(struct kmem_cache
*s
, unsigned long min
)
2964 if (min
< MIN_PARTIAL
)
2966 else if (min
> MAX_PARTIAL
)
2968 s
->min_partial
= min
;
2972 * calculate_sizes() determines the order and the distribution of data within
2975 static int calculate_sizes(struct kmem_cache
*s
, int forced_order
)
2977 unsigned long flags
= s
->flags
;
2978 unsigned long size
= s
->object_size
;
2982 * Round up object size to the next word boundary. We can only
2983 * place the free pointer at word boundaries and this determines
2984 * the possible location of the free pointer.
2986 size
= ALIGN(size
, sizeof(void *));
2988 #ifdef CONFIG_SLUB_DEBUG
2990 * Determine if we can poison the object itself. If the user of
2991 * the slab may touch the object after free or before allocation
2992 * then we should never poison the object itself.
2994 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2996 s
->flags
|= __OBJECT_POISON
;
2998 s
->flags
&= ~__OBJECT_POISON
;
3002 * If we are Redzoning then check if there is some space between the
3003 * end of the object and the free pointer. If not then add an
3004 * additional word to have some bytes to store Redzone information.
3006 if ((flags
& SLAB_RED_ZONE
) && size
== s
->object_size
)
3007 size
+= sizeof(void *);
3011 * With that we have determined the number of bytes in actual use
3012 * by the object. This is the potential offset to the free pointer.
3016 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
3019 * Relocate free pointer after the object if it is not
3020 * permitted to overwrite the first word of the object on
3023 * This is the case if we do RCU, have a constructor or
3024 * destructor or are poisoning the objects.
3027 size
+= sizeof(void *);
3030 #ifdef CONFIG_SLUB_DEBUG
3031 if (flags
& SLAB_STORE_USER
)
3033 * Need to store information about allocs and frees after
3036 size
+= 2 * sizeof(struct track
);
3038 if (flags
& SLAB_RED_ZONE
)
3040 * Add some empty padding so that we can catch
3041 * overwrites from earlier objects rather than let
3042 * tracking information or the free pointer be
3043 * corrupted if a user writes before the start
3046 size
+= sizeof(void *);
3050 * SLUB stores one object immediately after another beginning from
3051 * offset 0. In order to align the objects we have to simply size
3052 * each object to conform to the alignment.
3054 size
= ALIGN(size
, s
->align
);
3056 if (forced_order
>= 0)
3057 order
= forced_order
;
3059 order
= calculate_order(size
, s
->reserved
);
3066 s
->allocflags
|= __GFP_COMP
;
3068 if (s
->flags
& SLAB_CACHE_DMA
)
3069 s
->allocflags
|= GFP_DMA
;
3071 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
3072 s
->allocflags
|= __GFP_RECLAIMABLE
;
3075 * Determine the number of objects per slab
3077 s
->oo
= oo_make(order
, size
, s
->reserved
);
3078 s
->min
= oo_make(get_order(size
), size
, s
->reserved
);
3079 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
3082 return !!oo_objects(s
->oo
);
3085 static int kmem_cache_open(struct kmem_cache
*s
, unsigned long flags
)
3087 s
->flags
= kmem_cache_flags(s
->size
, flags
, s
->name
, s
->ctor
);
3090 if (need_reserve_slab_rcu
&& (s
->flags
& SLAB_DESTROY_BY_RCU
))
3091 s
->reserved
= sizeof(struct rcu_head
);
3093 if (!calculate_sizes(s
, -1))
3095 if (disable_higher_order_debug
) {
3097 * Disable debugging flags that store metadata if the min slab
3100 if (get_order(s
->size
) > get_order(s
->object_size
)) {
3101 s
->flags
&= ~DEBUG_METADATA_FLAGS
;
3103 if (!calculate_sizes(s
, -1))
3108 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
3109 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
3110 if (system_has_cmpxchg_double() && (s
->flags
& SLAB_DEBUG_FLAGS
) == 0)
3111 /* Enable fast mode */
3112 s
->flags
|= __CMPXCHG_DOUBLE
;
3116 * The larger the object size is, the more pages we want on the partial
3117 * list to avoid pounding the page allocator excessively.
3119 set_min_partial(s
, ilog2(s
->size
) / 2);
3122 * cpu_partial determined the maximum number of objects kept in the
3123 * per cpu partial lists of a processor.
3125 * Per cpu partial lists mainly contain slabs that just have one
3126 * object freed. If they are used for allocation then they can be
3127 * filled up again with minimal effort. The slab will never hit the
3128 * per node partial lists and therefore no locking will be required.
3130 * This setting also determines
3132 * A) The number of objects from per cpu partial slabs dumped to the
3133 * per node list when we reach the limit.
3134 * B) The number of objects in cpu partial slabs to extract from the
3135 * per node list when we run out of per cpu objects. We only fetch
3136 * 50% to keep some capacity around for frees.
3138 if (!kmem_cache_has_cpu_partial(s
))
3140 else if (s
->size
>= PAGE_SIZE
)
3142 else if (s
->size
>= 1024)
3144 else if (s
->size
>= 256)
3145 s
->cpu_partial
= 13;
3147 s
->cpu_partial
= 30;
3150 s
->remote_node_defrag_ratio
= 1000;
3152 if (!init_kmem_cache_nodes(s
))
3155 if (alloc_kmem_cache_cpus(s
))
3158 free_kmem_cache_nodes(s
);
3160 if (flags
& SLAB_PANIC
)
3161 panic("Cannot create slab %s size=%lu realsize=%u "
3162 "order=%u offset=%u flags=%lx\n",
3163 s
->name
, (unsigned long)s
->size
, s
->size
,
3164 oo_order(s
->oo
), s
->offset
, flags
);
3168 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
3171 #ifdef CONFIG_SLUB_DEBUG
3172 void *addr
= page_address(page
);
3174 unsigned long *map
= kzalloc(BITS_TO_LONGS(page
->objects
) *
3175 sizeof(long), GFP_ATOMIC
);
3178 slab_err(s
, page
, text
, s
->name
);
3181 get_map(s
, page
, map
);
3182 for_each_object(p
, s
, addr
, page
->objects
) {
3184 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
3185 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
3187 print_tracking(s
, p
);
3196 * Attempt to free all partial slabs on a node.
3197 * This is called from kmem_cache_close(). We must be the last thread
3198 * using the cache and therefore we do not need to lock anymore.
3200 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
3202 struct page
*page
, *h
;
3204 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
3206 __remove_partial(n
, page
);
3207 discard_slab(s
, page
);
3209 list_slab_objects(s
, page
,
3210 "Objects remaining in %s on kmem_cache_close()");
3216 * Release all resources used by a slab cache.
3218 static inline int kmem_cache_close(struct kmem_cache
*s
)
3223 /* Attempt to free all objects */
3224 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3225 struct kmem_cache_node
*n
= get_node(s
, node
);
3228 if (n
->nr_partial
|| slabs_node(s
, node
))
3231 free_percpu(s
->cpu_slab
);
3232 free_kmem_cache_nodes(s
);
3236 int __kmem_cache_shutdown(struct kmem_cache
*s
)
3238 return kmem_cache_close(s
);
3241 /********************************************************************
3243 *******************************************************************/
3245 static int __init
setup_slub_min_order(char *str
)
3247 get_option(&str
, &slub_min_order
);
3252 __setup("slub_min_order=", setup_slub_min_order
);
3254 static int __init
setup_slub_max_order(char *str
)
3256 get_option(&str
, &slub_max_order
);
3257 slub_max_order
= min(slub_max_order
, MAX_ORDER
- 1);
3262 __setup("slub_max_order=", setup_slub_max_order
);
3264 static int __init
setup_slub_min_objects(char *str
)
3266 get_option(&str
, &slub_min_objects
);
3271 __setup("slub_min_objects=", setup_slub_min_objects
);
3273 static int __init
setup_slub_nomerge(char *str
)
3279 __setup("slub_nomerge", setup_slub_nomerge
);
3281 void *__kmalloc(size_t size
, gfp_t flags
)
3283 struct kmem_cache
*s
;
3286 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
))
3287 return kmalloc_large(size
, flags
);
3289 s
= kmalloc_slab(size
, flags
);
3291 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3294 ret
= slab_alloc(s
, flags
, _RET_IP_
);
3296 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, flags
);
3300 EXPORT_SYMBOL(__kmalloc
);
3303 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
3308 flags
|= __GFP_COMP
| __GFP_NOTRACK
| __GFP_KMEMCG
;
3309 page
= alloc_pages_node(node
, flags
, get_order(size
));
3311 ptr
= page_address(page
);
3313 kmalloc_large_node_hook(ptr
, size
, flags
);
3317 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3319 struct kmem_cache
*s
;
3322 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
)) {
3323 ret
= kmalloc_large_node(size
, flags
, node
);
3325 trace_kmalloc_node(_RET_IP_
, ret
,
3326 size
, PAGE_SIZE
<< get_order(size
),
3332 s
= kmalloc_slab(size
, flags
);
3334 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3337 ret
= slab_alloc_node(s
, flags
, node
, _RET_IP_
);
3339 trace_kmalloc_node(_RET_IP_
, ret
, size
, s
->size
, flags
, node
);
3343 EXPORT_SYMBOL(__kmalloc_node
);
3346 size_t ksize(const void *object
)
3350 if (unlikely(object
== ZERO_SIZE_PTR
))
3353 page
= virt_to_head_page(object
);
3355 if (unlikely(!PageSlab(page
))) {
3356 WARN_ON(!PageCompound(page
));
3357 return PAGE_SIZE
<< compound_order(page
);
3360 return slab_ksize(page
->slab_cache
);
3362 EXPORT_SYMBOL(ksize
);
3364 void kfree(const void *x
)
3367 void *object
= (void *)x
;
3369 trace_kfree(_RET_IP_
, x
);
3371 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3374 page
= virt_to_head_page(x
);
3375 if (unlikely(!PageSlab(page
))) {
3376 BUG_ON(!PageCompound(page
));
3378 __free_memcg_kmem_pages(page
, compound_order(page
));
3381 slab_free(page
->slab_cache
, page
, object
, _RET_IP_
);
3383 EXPORT_SYMBOL(kfree
);
3386 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
3387 * the remaining slabs by the number of items in use. The slabs with the
3388 * most items in use come first. New allocations will then fill those up
3389 * and thus they can be removed from the partial lists.
3391 * The slabs with the least items are placed last. This results in them
3392 * being allocated from last increasing the chance that the last objects
3393 * are freed in them.
3395 int kmem_cache_shrink(struct kmem_cache
*s
)
3399 struct kmem_cache_node
*n
;
3402 int objects
= oo_objects(s
->max
);
3403 struct list_head
*slabs_by_inuse
=
3404 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
3405 unsigned long flags
;
3407 if (!slabs_by_inuse
)
3411 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3412 n
= get_node(s
, node
);
3417 for (i
= 0; i
< objects
; i
++)
3418 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
3420 spin_lock_irqsave(&n
->list_lock
, flags
);
3423 * Build lists indexed by the items in use in each slab.
3425 * Note that concurrent frees may occur while we hold the
3426 * list_lock. page->inuse here is the upper limit.
3428 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
3429 list_move(&page
->lru
, slabs_by_inuse
+ page
->inuse
);
3435 * Rebuild the partial list with the slabs filled up most
3436 * first and the least used slabs at the end.
3438 for (i
= objects
- 1; i
> 0; i
--)
3439 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
3441 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3443 /* Release empty slabs */
3444 list_for_each_entry_safe(page
, t
, slabs_by_inuse
, lru
)
3445 discard_slab(s
, page
);
3448 kfree(slabs_by_inuse
);
3451 EXPORT_SYMBOL(kmem_cache_shrink
);
3453 static int slab_mem_going_offline_callback(void *arg
)
3455 struct kmem_cache
*s
;
3457 mutex_lock(&slab_mutex
);
3458 list_for_each_entry(s
, &slab_caches
, list
)
3459 kmem_cache_shrink(s
);
3460 mutex_unlock(&slab_mutex
);
3465 static void slab_mem_offline_callback(void *arg
)
3467 struct kmem_cache_node
*n
;
3468 struct kmem_cache
*s
;
3469 struct memory_notify
*marg
= arg
;
3472 offline_node
= marg
->status_change_nid_normal
;
3475 * If the node still has available memory. we need kmem_cache_node
3478 if (offline_node
< 0)
3481 mutex_lock(&slab_mutex
);
3482 list_for_each_entry(s
, &slab_caches
, list
) {
3483 n
= get_node(s
, offline_node
);
3486 * if n->nr_slabs > 0, slabs still exist on the node
3487 * that is going down. We were unable to free them,
3488 * and offline_pages() function shouldn't call this
3489 * callback. So, we must fail.
3491 BUG_ON(slabs_node(s
, offline_node
));
3493 s
->node
[offline_node
] = NULL
;
3494 kmem_cache_free(kmem_cache_node
, n
);
3497 mutex_unlock(&slab_mutex
);
3500 static int slab_mem_going_online_callback(void *arg
)
3502 struct kmem_cache_node
*n
;
3503 struct kmem_cache
*s
;
3504 struct memory_notify
*marg
= arg
;
3505 int nid
= marg
->status_change_nid_normal
;
3509 * If the node's memory is already available, then kmem_cache_node is
3510 * already created. Nothing to do.
3516 * We are bringing a node online. No memory is available yet. We must
3517 * allocate a kmem_cache_node structure in order to bring the node
3520 mutex_lock(&slab_mutex
);
3521 list_for_each_entry(s
, &slab_caches
, list
) {
3523 * XXX: kmem_cache_alloc_node will fallback to other nodes
3524 * since memory is not yet available from the node that
3527 n
= kmem_cache_alloc(kmem_cache_node
, GFP_KERNEL
);
3532 init_kmem_cache_node(n
);
3536 mutex_unlock(&slab_mutex
);
3540 static int slab_memory_callback(struct notifier_block
*self
,
3541 unsigned long action
, void *arg
)
3546 case MEM_GOING_ONLINE
:
3547 ret
= slab_mem_going_online_callback(arg
);
3549 case MEM_GOING_OFFLINE
:
3550 ret
= slab_mem_going_offline_callback(arg
);
3553 case MEM_CANCEL_ONLINE
:
3554 slab_mem_offline_callback(arg
);
3557 case MEM_CANCEL_OFFLINE
:
3561 ret
= notifier_from_errno(ret
);
3567 static struct notifier_block slab_memory_callback_nb
= {
3568 .notifier_call
= slab_memory_callback
,
3569 .priority
= SLAB_CALLBACK_PRI
,
3572 /********************************************************************
3573 * Basic setup of slabs
3574 *******************************************************************/
3577 * Used for early kmem_cache structures that were allocated using
3578 * the page allocator. Allocate them properly then fix up the pointers
3579 * that may be pointing to the wrong kmem_cache structure.
3582 static struct kmem_cache
* __init
bootstrap(struct kmem_cache
*static_cache
)
3585 struct kmem_cache
*s
= kmem_cache_zalloc(kmem_cache
, GFP_NOWAIT
);
3587 memcpy(s
, static_cache
, kmem_cache
->object_size
);
3590 * This runs very early, and only the boot processor is supposed to be
3591 * up. Even if it weren't true, IRQs are not up so we couldn't fire
3594 __flush_cpu_slab(s
, smp_processor_id());
3595 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3596 struct kmem_cache_node
*n
= get_node(s
, node
);
3600 list_for_each_entry(p
, &n
->partial
, lru
)
3603 #ifdef CONFIG_SLUB_DEBUG
3604 list_for_each_entry(p
, &n
->full
, lru
)
3609 list_add(&s
->list
, &slab_caches
);
3613 void __init
kmem_cache_init(void)
3615 static __initdata
struct kmem_cache boot_kmem_cache
,
3616 boot_kmem_cache_node
;
3618 if (debug_guardpage_minorder())
3621 kmem_cache_node
= &boot_kmem_cache_node
;
3622 kmem_cache
= &boot_kmem_cache
;
3624 create_boot_cache(kmem_cache_node
, "kmem_cache_node",
3625 sizeof(struct kmem_cache_node
), SLAB_HWCACHE_ALIGN
);
3627 register_hotmemory_notifier(&slab_memory_callback_nb
);
3629 /* Able to allocate the per node structures */
3630 slab_state
= PARTIAL
;
3632 create_boot_cache(kmem_cache
, "kmem_cache",
3633 offsetof(struct kmem_cache
, node
) +
3634 nr_node_ids
* sizeof(struct kmem_cache_node
*),
3635 SLAB_HWCACHE_ALIGN
);
3637 kmem_cache
= bootstrap(&boot_kmem_cache
);
3640 * Allocate kmem_cache_node properly from the kmem_cache slab.
3641 * kmem_cache_node is separately allocated so no need to
3642 * update any list pointers.
3644 kmem_cache_node
= bootstrap(&boot_kmem_cache_node
);
3646 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3647 create_kmalloc_caches(0);
3650 register_cpu_notifier(&slab_notifier
);
3654 "SLUB: HWalign=%d, Order=%d-%d, MinObjects=%d,"
3655 " CPUs=%d, Nodes=%d\n",
3657 slub_min_order
, slub_max_order
, slub_min_objects
,
3658 nr_cpu_ids
, nr_node_ids
);
3661 void __init
kmem_cache_init_late(void)
3666 * Find a mergeable slab cache
3668 static int slab_unmergeable(struct kmem_cache
*s
)
3670 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3673 if (!is_root_cache(s
))
3680 * We may have set a slab to be unmergeable during bootstrap.
3682 if (s
->refcount
< 0)
3688 static struct kmem_cache
*find_mergeable(size_t size
, size_t align
,
3689 unsigned long flags
, const char *name
, void (*ctor
)(void *))
3691 struct kmem_cache
*s
;
3693 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3699 size
= ALIGN(size
, sizeof(void *));
3700 align
= calculate_alignment(flags
, align
, size
);
3701 size
= ALIGN(size
, align
);
3702 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3704 list_for_each_entry(s
, &slab_caches
, list
) {
3705 if (slab_unmergeable(s
))
3711 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3714 * Check if alignment is compatible.
3715 * Courtesy of Adrian Drzewiecki
3717 if ((s
->size
& ~(align
- 1)) != s
->size
)
3720 if (s
->size
- size
>= sizeof(void *))
3729 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
3730 unsigned long flags
, void (*ctor
)(void *))
3732 struct kmem_cache
*s
;
3734 s
= find_mergeable(size
, align
, flags
, name
, ctor
);
3737 struct kmem_cache
*c
;
3742 * Adjust the object sizes so that we clear
3743 * the complete object on kzalloc.
3745 s
->object_size
= max(s
->object_size
, (int)size
);
3746 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3748 for_each_memcg_cache_index(i
) {
3749 c
= cache_from_memcg_idx(s
, i
);
3752 c
->object_size
= s
->object_size
;
3753 c
->inuse
= max_t(int, c
->inuse
,
3754 ALIGN(size
, sizeof(void *)));
3757 if (sysfs_slab_alias(s
, name
)) {
3766 int __kmem_cache_create(struct kmem_cache
*s
, unsigned long flags
)
3770 err
= kmem_cache_open(s
, flags
);
3774 /* Mutex is not taken during early boot */
3775 if (slab_state
<= UP
)
3778 memcg_propagate_slab_attrs(s
);
3779 err
= sysfs_slab_add(s
);
3781 kmem_cache_close(s
);
3788 * Use the cpu notifier to insure that the cpu slabs are flushed when
3791 static int slab_cpuup_callback(struct notifier_block
*nfb
,
3792 unsigned long action
, void *hcpu
)
3794 long cpu
= (long)hcpu
;
3795 struct kmem_cache
*s
;
3796 unsigned long flags
;
3799 case CPU_UP_CANCELED
:
3800 case CPU_UP_CANCELED_FROZEN
:
3802 case CPU_DEAD_FROZEN
:
3803 mutex_lock(&slab_mutex
);
3804 list_for_each_entry(s
, &slab_caches
, list
) {
3805 local_irq_save(flags
);
3806 __flush_cpu_slab(s
, cpu
);
3807 local_irq_restore(flags
);
3809 mutex_unlock(&slab_mutex
);
3817 static struct notifier_block slab_notifier
= {
3818 .notifier_call
= slab_cpuup_callback
3823 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, unsigned long caller
)
3825 struct kmem_cache
*s
;
3828 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
))
3829 return kmalloc_large(size
, gfpflags
);
3831 s
= kmalloc_slab(size
, gfpflags
);
3833 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3836 ret
= slab_alloc(s
, gfpflags
, caller
);
3838 /* Honor the call site pointer we received. */
3839 trace_kmalloc(caller
, ret
, size
, s
->size
, gfpflags
);
3845 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3846 int node
, unsigned long caller
)
3848 struct kmem_cache
*s
;
3851 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
)) {
3852 ret
= kmalloc_large_node(size
, gfpflags
, node
);
3854 trace_kmalloc_node(caller
, ret
,
3855 size
, PAGE_SIZE
<< get_order(size
),
3861 s
= kmalloc_slab(size
, gfpflags
);
3863 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3866 ret
= slab_alloc_node(s
, gfpflags
, node
, caller
);
3868 /* Honor the call site pointer we received. */
3869 trace_kmalloc_node(caller
, ret
, size
, s
->size
, gfpflags
, node
);
3876 static int count_inuse(struct page
*page
)
3881 static int count_total(struct page
*page
)
3883 return page
->objects
;
3887 #ifdef CONFIG_SLUB_DEBUG
3888 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3892 void *addr
= page_address(page
);
3894 if (!check_slab(s
, page
) ||
3895 !on_freelist(s
, page
, NULL
))
3898 /* Now we know that a valid freelist exists */
3899 bitmap_zero(map
, page
->objects
);
3901 get_map(s
, page
, map
);
3902 for_each_object(p
, s
, addr
, page
->objects
) {
3903 if (test_bit(slab_index(p
, s
, addr
), map
))
3904 if (!check_object(s
, page
, p
, SLUB_RED_INACTIVE
))
3908 for_each_object(p
, s
, addr
, page
->objects
)
3909 if (!test_bit(slab_index(p
, s
, addr
), map
))
3910 if (!check_object(s
, page
, p
, SLUB_RED_ACTIVE
))
3915 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
3919 validate_slab(s
, page
, map
);
3923 static int validate_slab_node(struct kmem_cache
*s
,
3924 struct kmem_cache_node
*n
, unsigned long *map
)
3926 unsigned long count
= 0;
3928 unsigned long flags
;
3930 spin_lock_irqsave(&n
->list_lock
, flags
);
3932 list_for_each_entry(page
, &n
->partial
, lru
) {
3933 validate_slab_slab(s
, page
, map
);
3936 if (count
!= n
->nr_partial
)
3937 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
3938 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
3940 if (!(s
->flags
& SLAB_STORE_USER
))
3943 list_for_each_entry(page
, &n
->full
, lru
) {
3944 validate_slab_slab(s
, page
, map
);
3947 if (count
!= atomic_long_read(&n
->nr_slabs
))
3948 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
3949 "counter=%ld\n", s
->name
, count
,
3950 atomic_long_read(&n
->nr_slabs
));
3953 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3957 static long validate_slab_cache(struct kmem_cache
*s
)
3960 unsigned long count
= 0;
3961 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
3962 sizeof(unsigned long), GFP_KERNEL
);
3968 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3969 struct kmem_cache_node
*n
= get_node(s
, node
);
3971 count
+= validate_slab_node(s
, n
, map
);
3977 * Generate lists of code addresses where slabcache objects are allocated
3982 unsigned long count
;
3989 DECLARE_BITMAP(cpus
, NR_CPUS
);
3995 unsigned long count
;
3996 struct location
*loc
;
3999 static void free_loc_track(struct loc_track
*t
)
4002 free_pages((unsigned long)t
->loc
,
4003 get_order(sizeof(struct location
) * t
->max
));
4006 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
4011 order
= get_order(sizeof(struct location
) * max
);
4013 l
= (void *)__get_free_pages(flags
, order
);
4018 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
4026 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
4027 const struct track
*track
)
4029 long start
, end
, pos
;
4031 unsigned long caddr
;
4032 unsigned long age
= jiffies
- track
->when
;
4038 pos
= start
+ (end
- start
+ 1) / 2;
4041 * There is nothing at "end". If we end up there
4042 * we need to add something to before end.
4047 caddr
= t
->loc
[pos
].addr
;
4048 if (track
->addr
== caddr
) {
4054 if (age
< l
->min_time
)
4056 if (age
> l
->max_time
)
4059 if (track
->pid
< l
->min_pid
)
4060 l
->min_pid
= track
->pid
;
4061 if (track
->pid
> l
->max_pid
)
4062 l
->max_pid
= track
->pid
;
4064 cpumask_set_cpu(track
->cpu
,
4065 to_cpumask(l
->cpus
));
4067 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4071 if (track
->addr
< caddr
)
4078 * Not found. Insert new tracking element.
4080 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
4086 (t
->count
- pos
) * sizeof(struct location
));
4089 l
->addr
= track
->addr
;
4093 l
->min_pid
= track
->pid
;
4094 l
->max_pid
= track
->pid
;
4095 cpumask_clear(to_cpumask(l
->cpus
));
4096 cpumask_set_cpu(track
->cpu
, to_cpumask(l
->cpus
));
4097 nodes_clear(l
->nodes
);
4098 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4102 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
4103 struct page
*page
, enum track_item alloc
,
4106 void *addr
= page_address(page
);
4109 bitmap_zero(map
, page
->objects
);
4110 get_map(s
, page
, map
);
4112 for_each_object(p
, s
, addr
, page
->objects
)
4113 if (!test_bit(slab_index(p
, s
, addr
), map
))
4114 add_location(t
, s
, get_track(s
, p
, alloc
));
4117 static int list_locations(struct kmem_cache
*s
, char *buf
,
4118 enum track_item alloc
)
4122 struct loc_track t
= { 0, 0, NULL
};
4124 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
4125 sizeof(unsigned long), GFP_KERNEL
);
4127 if (!map
|| !alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
4130 return sprintf(buf
, "Out of memory\n");
4132 /* Push back cpu slabs */
4135 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4136 struct kmem_cache_node
*n
= get_node(s
, node
);
4137 unsigned long flags
;
4140 if (!atomic_long_read(&n
->nr_slabs
))
4143 spin_lock_irqsave(&n
->list_lock
, flags
);
4144 list_for_each_entry(page
, &n
->partial
, lru
)
4145 process_slab(&t
, s
, page
, alloc
, map
);
4146 list_for_each_entry(page
, &n
->full
, lru
)
4147 process_slab(&t
, s
, page
, alloc
, map
);
4148 spin_unlock_irqrestore(&n
->list_lock
, flags
);
4151 for (i
= 0; i
< t
.count
; i
++) {
4152 struct location
*l
= &t
.loc
[i
];
4154 if (len
> PAGE_SIZE
- KSYM_SYMBOL_LEN
- 100)
4156 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
4159 len
+= sprintf(buf
+ len
, "%pS", (void *)l
->addr
);
4161 len
+= sprintf(buf
+ len
, "<not-available>");
4163 if (l
->sum_time
!= l
->min_time
) {
4164 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
4166 (long)div_u64(l
->sum_time
, l
->count
),
4169 len
+= sprintf(buf
+ len
, " age=%ld",
4172 if (l
->min_pid
!= l
->max_pid
)
4173 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
4174 l
->min_pid
, l
->max_pid
);
4176 len
+= sprintf(buf
+ len
, " pid=%ld",
4179 if (num_online_cpus() > 1 &&
4180 !cpumask_empty(to_cpumask(l
->cpus
)) &&
4181 len
< PAGE_SIZE
- 60) {
4182 len
+= sprintf(buf
+ len
, " cpus=");
4183 len
+= cpulist_scnprintf(buf
+ len
,
4184 PAGE_SIZE
- len
- 50,
4185 to_cpumask(l
->cpus
));
4188 if (nr_online_nodes
> 1 && !nodes_empty(l
->nodes
) &&
4189 len
< PAGE_SIZE
- 60) {
4190 len
+= sprintf(buf
+ len
, " nodes=");
4191 len
+= nodelist_scnprintf(buf
+ len
,
4192 PAGE_SIZE
- len
- 50,
4196 len
+= sprintf(buf
+ len
, "\n");
4202 len
+= sprintf(buf
, "No data\n");
4207 #ifdef SLUB_RESILIENCY_TEST
4208 static void resiliency_test(void)
4212 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 16 || KMALLOC_SHIFT_HIGH
< 10);
4214 printk(KERN_ERR
"SLUB resiliency testing\n");
4215 printk(KERN_ERR
"-----------------------\n");
4216 printk(KERN_ERR
"A. Corruption after allocation\n");
4218 p
= kzalloc(16, GFP_KERNEL
);
4220 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
4221 " 0x12->0x%p\n\n", p
+ 16);
4223 validate_slab_cache(kmalloc_caches
[4]);
4225 /* Hmmm... The next two are dangerous */
4226 p
= kzalloc(32, GFP_KERNEL
);
4227 p
[32 + sizeof(void *)] = 0x34;
4228 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
4229 " 0x34 -> -0x%p\n", p
);
4231 "If allocated object is overwritten then not detectable\n\n");
4233 validate_slab_cache(kmalloc_caches
[5]);
4234 p
= kzalloc(64, GFP_KERNEL
);
4235 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
4237 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
4240 "If allocated object is overwritten then not detectable\n\n");
4241 validate_slab_cache(kmalloc_caches
[6]);
4243 printk(KERN_ERR
"\nB. Corruption after free\n");
4244 p
= kzalloc(128, GFP_KERNEL
);
4247 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
4248 validate_slab_cache(kmalloc_caches
[7]);
4250 p
= kzalloc(256, GFP_KERNEL
);
4253 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
4255 validate_slab_cache(kmalloc_caches
[8]);
4257 p
= kzalloc(512, GFP_KERNEL
);
4260 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
4261 validate_slab_cache(kmalloc_caches
[9]);
4265 static void resiliency_test(void) {};
4270 enum slab_stat_type
{
4271 SL_ALL
, /* All slabs */
4272 SL_PARTIAL
, /* Only partially allocated slabs */
4273 SL_CPU
, /* Only slabs used for cpu caches */
4274 SL_OBJECTS
, /* Determine allocated objects not slabs */
4275 SL_TOTAL
/* Determine object capacity not slabs */
4278 #define SO_ALL (1 << SL_ALL)
4279 #define SO_PARTIAL (1 << SL_PARTIAL)
4280 #define SO_CPU (1 << SL_CPU)
4281 #define SO_OBJECTS (1 << SL_OBJECTS)
4282 #define SO_TOTAL (1 << SL_TOTAL)
4284 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
4285 char *buf
, unsigned long flags
)
4287 unsigned long total
= 0;
4290 unsigned long *nodes
;
4292 nodes
= kzalloc(sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
4296 if (flags
& SO_CPU
) {
4299 for_each_possible_cpu(cpu
) {
4300 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
,
4305 page
= ACCESS_ONCE(c
->page
);
4309 node
= page_to_nid(page
);
4310 if (flags
& SO_TOTAL
)
4312 else if (flags
& SO_OBJECTS
)
4320 page
= ACCESS_ONCE(c
->partial
);
4322 node
= page_to_nid(page
);
4323 if (flags
& SO_TOTAL
)
4325 else if (flags
& SO_OBJECTS
)
4335 lock_memory_hotplug();
4336 #ifdef CONFIG_SLUB_DEBUG
4337 if (flags
& SO_ALL
) {
4338 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4339 struct kmem_cache_node
*n
= get_node(s
, node
);
4341 if (flags
& SO_TOTAL
)
4342 x
= atomic_long_read(&n
->total_objects
);
4343 else if (flags
& SO_OBJECTS
)
4344 x
= atomic_long_read(&n
->total_objects
) -
4345 count_partial(n
, count_free
);
4347 x
= atomic_long_read(&n
->nr_slabs
);
4354 if (flags
& SO_PARTIAL
) {
4355 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4356 struct kmem_cache_node
*n
= get_node(s
, node
);
4358 if (flags
& SO_TOTAL
)
4359 x
= count_partial(n
, count_total
);
4360 else if (flags
& SO_OBJECTS
)
4361 x
= count_partial(n
, count_inuse
);
4368 x
= sprintf(buf
, "%lu", total
);
4370 for_each_node_state(node
, N_NORMAL_MEMORY
)
4372 x
+= sprintf(buf
+ x
, " N%d=%lu",
4375 unlock_memory_hotplug();
4377 return x
+ sprintf(buf
+ x
, "\n");
4380 #ifdef CONFIG_SLUB_DEBUG
4381 static int any_slab_objects(struct kmem_cache
*s
)
4385 for_each_online_node(node
) {
4386 struct kmem_cache_node
*n
= get_node(s
, node
);
4391 if (atomic_long_read(&n
->total_objects
))
4398 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4399 #define to_slab(n) container_of(n, struct kmem_cache, kobj)
4401 struct slab_attribute
{
4402 struct attribute attr
;
4403 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
4404 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
4407 #define SLAB_ATTR_RO(_name) \
4408 static struct slab_attribute _name##_attr = \
4409 __ATTR(_name, 0400, _name##_show, NULL)
4411 #define SLAB_ATTR(_name) \
4412 static struct slab_attribute _name##_attr = \
4413 __ATTR(_name, 0600, _name##_show, _name##_store)
4415 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
4417 return sprintf(buf
, "%d\n", s
->size
);
4419 SLAB_ATTR_RO(slab_size
);
4421 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
4423 return sprintf(buf
, "%d\n", s
->align
);
4425 SLAB_ATTR_RO(align
);
4427 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
4429 return sprintf(buf
, "%d\n", s
->object_size
);
4431 SLAB_ATTR_RO(object_size
);
4433 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
4435 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
4437 SLAB_ATTR_RO(objs_per_slab
);
4439 static ssize_t
order_store(struct kmem_cache
*s
,
4440 const char *buf
, size_t length
)
4442 unsigned long order
;
4445 err
= kstrtoul(buf
, 10, &order
);
4449 if (order
> slub_max_order
|| order
< slub_min_order
)
4452 calculate_sizes(s
, order
);
4456 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
4458 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
4462 static ssize_t
min_partial_show(struct kmem_cache
*s
, char *buf
)
4464 return sprintf(buf
, "%lu\n", s
->min_partial
);
4467 static ssize_t
min_partial_store(struct kmem_cache
*s
, const char *buf
,
4473 err
= kstrtoul(buf
, 10, &min
);
4477 set_min_partial(s
, min
);
4480 SLAB_ATTR(min_partial
);
4482 static ssize_t
cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4484 return sprintf(buf
, "%u\n", s
->cpu_partial
);
4487 static ssize_t
cpu_partial_store(struct kmem_cache
*s
, const char *buf
,
4490 unsigned long objects
;
4493 err
= kstrtoul(buf
, 10, &objects
);
4496 if (objects
&& !kmem_cache_has_cpu_partial(s
))
4499 s
->cpu_partial
= objects
;
4503 SLAB_ATTR(cpu_partial
);
4505 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
4509 return sprintf(buf
, "%pS\n", s
->ctor
);
4513 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
4515 return sprintf(buf
, "%d\n", s
->refcount
- 1);
4517 SLAB_ATTR_RO(aliases
);
4519 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
4521 return show_slab_objects(s
, buf
, SO_PARTIAL
);
4523 SLAB_ATTR_RO(partial
);
4525 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
4527 return show_slab_objects(s
, buf
, SO_CPU
);
4529 SLAB_ATTR_RO(cpu_slabs
);
4531 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
4533 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
4535 SLAB_ATTR_RO(objects
);
4537 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
4539 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
4541 SLAB_ATTR_RO(objects_partial
);
4543 static ssize_t
slabs_cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4550 for_each_online_cpu(cpu
) {
4551 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
)->partial
;
4554 pages
+= page
->pages
;
4555 objects
+= page
->pobjects
;
4559 len
= sprintf(buf
, "%d(%d)", objects
, pages
);
4562 for_each_online_cpu(cpu
) {
4563 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
) ->partial
;
4565 if (page
&& len
< PAGE_SIZE
- 20)
4566 len
+= sprintf(buf
+ len
, " C%d=%d(%d)", cpu
,
4567 page
->pobjects
, page
->pages
);
4570 return len
+ sprintf(buf
+ len
, "\n");
4572 SLAB_ATTR_RO(slabs_cpu_partial
);
4574 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
4576 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
4579 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
4580 const char *buf
, size_t length
)
4582 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
4584 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
4587 SLAB_ATTR(reclaim_account
);
4589 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
4591 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
4593 SLAB_ATTR_RO(hwcache_align
);
4595 #ifdef CONFIG_ZONE_DMA
4596 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
4598 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
4600 SLAB_ATTR_RO(cache_dma
);
4603 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
4605 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
4607 SLAB_ATTR_RO(destroy_by_rcu
);
4609 static ssize_t
reserved_show(struct kmem_cache
*s
, char *buf
)
4611 return sprintf(buf
, "%d\n", s
->reserved
);
4613 SLAB_ATTR_RO(reserved
);
4615 #ifdef CONFIG_SLUB_DEBUG
4616 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
4618 return show_slab_objects(s
, buf
, SO_ALL
);
4620 SLAB_ATTR_RO(slabs
);
4622 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
4624 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
4626 SLAB_ATTR_RO(total_objects
);
4628 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
4630 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
4633 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
4634 const char *buf
, size_t length
)
4636 s
->flags
&= ~SLAB_DEBUG_FREE
;
4637 if (buf
[0] == '1') {
4638 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4639 s
->flags
|= SLAB_DEBUG_FREE
;
4643 SLAB_ATTR(sanity_checks
);
4645 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
4647 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
4650 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
4653 s
->flags
&= ~SLAB_TRACE
;
4654 if (buf
[0] == '1') {
4655 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4656 s
->flags
|= SLAB_TRACE
;
4662 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
4664 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
4667 static ssize_t
red_zone_store(struct kmem_cache
*s
,
4668 const char *buf
, size_t length
)
4670 if (any_slab_objects(s
))
4673 s
->flags
&= ~SLAB_RED_ZONE
;
4674 if (buf
[0] == '1') {
4675 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4676 s
->flags
|= SLAB_RED_ZONE
;
4678 calculate_sizes(s
, -1);
4681 SLAB_ATTR(red_zone
);
4683 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
4685 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
4688 static ssize_t
poison_store(struct kmem_cache
*s
,
4689 const char *buf
, size_t length
)
4691 if (any_slab_objects(s
))
4694 s
->flags
&= ~SLAB_POISON
;
4695 if (buf
[0] == '1') {
4696 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4697 s
->flags
|= SLAB_POISON
;
4699 calculate_sizes(s
, -1);
4704 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4706 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4709 static ssize_t
store_user_store(struct kmem_cache
*s
,
4710 const char *buf
, size_t length
)
4712 if (any_slab_objects(s
))
4715 s
->flags
&= ~SLAB_STORE_USER
;
4716 if (buf
[0] == '1') {
4717 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4718 s
->flags
|= SLAB_STORE_USER
;
4720 calculate_sizes(s
, -1);
4723 SLAB_ATTR(store_user
);
4725 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4730 static ssize_t
validate_store(struct kmem_cache
*s
,
4731 const char *buf
, size_t length
)
4735 if (buf
[0] == '1') {
4736 ret
= validate_slab_cache(s
);
4742 SLAB_ATTR(validate
);
4744 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4746 if (!(s
->flags
& SLAB_STORE_USER
))
4748 return list_locations(s
, buf
, TRACK_ALLOC
);
4750 SLAB_ATTR_RO(alloc_calls
);
4752 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4754 if (!(s
->flags
& SLAB_STORE_USER
))
4756 return list_locations(s
, buf
, TRACK_FREE
);
4758 SLAB_ATTR_RO(free_calls
);
4759 #endif /* CONFIG_SLUB_DEBUG */
4761 #ifdef CONFIG_FAILSLAB
4762 static ssize_t
failslab_show(struct kmem_cache
*s
, char *buf
)
4764 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_FAILSLAB
));
4767 static ssize_t
failslab_store(struct kmem_cache
*s
, const char *buf
,
4770 s
->flags
&= ~SLAB_FAILSLAB
;
4772 s
->flags
|= SLAB_FAILSLAB
;
4775 SLAB_ATTR(failslab
);
4778 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4783 static ssize_t
shrink_store(struct kmem_cache
*s
,
4784 const char *buf
, size_t length
)
4786 if (buf
[0] == '1') {
4787 int rc
= kmem_cache_shrink(s
);
4798 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4800 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4803 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4804 const char *buf
, size_t length
)
4806 unsigned long ratio
;
4809 err
= kstrtoul(buf
, 10, &ratio
);
4814 s
->remote_node_defrag_ratio
= ratio
* 10;
4818 SLAB_ATTR(remote_node_defrag_ratio
);
4821 #ifdef CONFIG_SLUB_STATS
4822 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4824 unsigned long sum
= 0;
4827 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4832 for_each_online_cpu(cpu
) {
4833 unsigned x
= per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
];
4839 len
= sprintf(buf
, "%lu", sum
);
4842 for_each_online_cpu(cpu
) {
4843 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4844 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4848 return len
+ sprintf(buf
+ len
, "\n");
4851 static void clear_stat(struct kmem_cache
*s
, enum stat_item si
)
4855 for_each_online_cpu(cpu
)
4856 per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
] = 0;
4859 #define STAT_ATTR(si, text) \
4860 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4862 return show_stat(s, buf, si); \
4864 static ssize_t text##_store(struct kmem_cache *s, \
4865 const char *buf, size_t length) \
4867 if (buf[0] != '0') \
4869 clear_stat(s, si); \
4874 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4875 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4876 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4877 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4878 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4879 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4880 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4881 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4882 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4883 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4884 STAT_ATTR(ALLOC_NODE_MISMATCH
, alloc_node_mismatch
);
4885 STAT_ATTR(FREE_SLAB
, free_slab
);
4886 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4887 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4888 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4889 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4890 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4891 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4892 STAT_ATTR(DEACTIVATE_BYPASS
, deactivate_bypass
);
4893 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4894 STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL
, cmpxchg_double_cpu_fail
);
4895 STAT_ATTR(CMPXCHG_DOUBLE_FAIL
, cmpxchg_double_fail
);
4896 STAT_ATTR(CPU_PARTIAL_ALLOC
, cpu_partial_alloc
);
4897 STAT_ATTR(CPU_PARTIAL_FREE
, cpu_partial_free
);
4898 STAT_ATTR(CPU_PARTIAL_NODE
, cpu_partial_node
);
4899 STAT_ATTR(CPU_PARTIAL_DRAIN
, cpu_partial_drain
);
4902 static struct attribute
*slab_attrs
[] = {
4903 &slab_size_attr
.attr
,
4904 &object_size_attr
.attr
,
4905 &objs_per_slab_attr
.attr
,
4907 &min_partial_attr
.attr
,
4908 &cpu_partial_attr
.attr
,
4910 &objects_partial_attr
.attr
,
4912 &cpu_slabs_attr
.attr
,
4916 &hwcache_align_attr
.attr
,
4917 &reclaim_account_attr
.attr
,
4918 &destroy_by_rcu_attr
.attr
,
4920 &reserved_attr
.attr
,
4921 &slabs_cpu_partial_attr
.attr
,
4922 #ifdef CONFIG_SLUB_DEBUG
4923 &total_objects_attr
.attr
,
4925 &sanity_checks_attr
.attr
,
4927 &red_zone_attr
.attr
,
4929 &store_user_attr
.attr
,
4930 &validate_attr
.attr
,
4931 &alloc_calls_attr
.attr
,
4932 &free_calls_attr
.attr
,
4934 #ifdef CONFIG_ZONE_DMA
4935 &cache_dma_attr
.attr
,
4938 &remote_node_defrag_ratio_attr
.attr
,
4940 #ifdef CONFIG_SLUB_STATS
4941 &alloc_fastpath_attr
.attr
,
4942 &alloc_slowpath_attr
.attr
,
4943 &free_fastpath_attr
.attr
,
4944 &free_slowpath_attr
.attr
,
4945 &free_frozen_attr
.attr
,
4946 &free_add_partial_attr
.attr
,
4947 &free_remove_partial_attr
.attr
,
4948 &alloc_from_partial_attr
.attr
,
4949 &alloc_slab_attr
.attr
,
4950 &alloc_refill_attr
.attr
,
4951 &alloc_node_mismatch_attr
.attr
,
4952 &free_slab_attr
.attr
,
4953 &cpuslab_flush_attr
.attr
,
4954 &deactivate_full_attr
.attr
,
4955 &deactivate_empty_attr
.attr
,
4956 &deactivate_to_head_attr
.attr
,
4957 &deactivate_to_tail_attr
.attr
,
4958 &deactivate_remote_frees_attr
.attr
,
4959 &deactivate_bypass_attr
.attr
,
4960 &order_fallback_attr
.attr
,
4961 &cmpxchg_double_fail_attr
.attr
,
4962 &cmpxchg_double_cpu_fail_attr
.attr
,
4963 &cpu_partial_alloc_attr
.attr
,
4964 &cpu_partial_free_attr
.attr
,
4965 &cpu_partial_node_attr
.attr
,
4966 &cpu_partial_drain_attr
.attr
,
4968 #ifdef CONFIG_FAILSLAB
4969 &failslab_attr
.attr
,
4975 static struct attribute_group slab_attr_group
= {
4976 .attrs
= slab_attrs
,
4979 static ssize_t
slab_attr_show(struct kobject
*kobj
,
4980 struct attribute
*attr
,
4983 struct slab_attribute
*attribute
;
4984 struct kmem_cache
*s
;
4987 attribute
= to_slab_attr(attr
);
4990 if (!attribute
->show
)
4993 err
= attribute
->show(s
, buf
);
4998 static ssize_t
slab_attr_store(struct kobject
*kobj
,
4999 struct attribute
*attr
,
5000 const char *buf
, size_t len
)
5002 struct slab_attribute
*attribute
;
5003 struct kmem_cache
*s
;
5006 attribute
= to_slab_attr(attr
);
5009 if (!attribute
->store
)
5012 err
= attribute
->store(s
, buf
, len
);
5013 #ifdef CONFIG_MEMCG_KMEM
5014 if (slab_state
>= FULL
&& err
>= 0 && is_root_cache(s
)) {
5017 mutex_lock(&slab_mutex
);
5018 if (s
->max_attr_size
< len
)
5019 s
->max_attr_size
= len
;
5022 * This is a best effort propagation, so this function's return
5023 * value will be determined by the parent cache only. This is
5024 * basically because not all attributes will have a well
5025 * defined semantics for rollbacks - most of the actions will
5026 * have permanent effects.
5028 * Returning the error value of any of the children that fail
5029 * is not 100 % defined, in the sense that users seeing the
5030 * error code won't be able to know anything about the state of
5033 * Only returning the error code for the parent cache at least
5034 * has well defined semantics. The cache being written to
5035 * directly either failed or succeeded, in which case we loop
5036 * through the descendants with best-effort propagation.
5038 for_each_memcg_cache_index(i
) {
5039 struct kmem_cache
*c
= cache_from_memcg_idx(s
, i
);
5041 attribute
->store(c
, buf
, len
);
5043 mutex_unlock(&slab_mutex
);
5049 static void memcg_propagate_slab_attrs(struct kmem_cache
*s
)
5051 #ifdef CONFIG_MEMCG_KMEM
5053 char *buffer
= NULL
;
5054 struct kmem_cache
*root_cache
;
5056 if (is_root_cache(s
))
5059 root_cache
= s
->memcg_params
->root_cache
;
5062 * This mean this cache had no attribute written. Therefore, no point
5063 * in copying default values around
5065 if (!root_cache
->max_attr_size
)
5068 for (i
= 0; i
< ARRAY_SIZE(slab_attrs
); i
++) {
5071 struct slab_attribute
*attr
= to_slab_attr(slab_attrs
[i
]);
5073 if (!attr
|| !attr
->store
|| !attr
->show
)
5077 * It is really bad that we have to allocate here, so we will
5078 * do it only as a fallback. If we actually allocate, though,
5079 * we can just use the allocated buffer until the end.
5081 * Most of the slub attributes will tend to be very small in
5082 * size, but sysfs allows buffers up to a page, so they can
5083 * theoretically happen.
5087 else if (root_cache
->max_attr_size
< ARRAY_SIZE(mbuf
))
5090 buffer
= (char *) get_zeroed_page(GFP_KERNEL
);
5091 if (WARN_ON(!buffer
))
5096 attr
->show(root_cache
, buf
);
5097 attr
->store(s
, buf
, strlen(buf
));
5101 free_page((unsigned long)buffer
);
5105 static void kmem_cache_release(struct kobject
*k
)
5107 slab_kmem_cache_release(to_slab(k
));
5110 static const struct sysfs_ops slab_sysfs_ops
= {
5111 .show
= slab_attr_show
,
5112 .store
= slab_attr_store
,
5115 static struct kobj_type slab_ktype
= {
5116 .sysfs_ops
= &slab_sysfs_ops
,
5117 .release
= kmem_cache_release
,
5120 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
5122 struct kobj_type
*ktype
= get_ktype(kobj
);
5124 if (ktype
== &slab_ktype
)
5129 static const struct kset_uevent_ops slab_uevent_ops
= {
5130 .filter
= uevent_filter
,
5133 static struct kset
*slab_kset
;
5135 static inline struct kset
*cache_kset(struct kmem_cache
*s
)
5137 #ifdef CONFIG_MEMCG_KMEM
5138 if (!is_root_cache(s
))
5139 return s
->memcg_params
->root_cache
->memcg_kset
;
5144 #define ID_STR_LENGTH 64
5146 /* Create a unique string id for a slab cache:
5148 * Format :[flags-]size
5150 static char *create_unique_id(struct kmem_cache
*s
)
5152 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
5159 * First flags affecting slabcache operations. We will only
5160 * get here for aliasable slabs so we do not need to support
5161 * too many flags. The flags here must cover all flags that
5162 * are matched during merging to guarantee that the id is
5165 if (s
->flags
& SLAB_CACHE_DMA
)
5167 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
5169 if (s
->flags
& SLAB_DEBUG_FREE
)
5171 if (!(s
->flags
& SLAB_NOTRACK
))
5175 p
+= sprintf(p
, "%07d", s
->size
);
5177 #ifdef CONFIG_MEMCG_KMEM
5178 if (!is_root_cache(s
))
5179 p
+= sprintf(p
, "-%08d",
5180 memcg_cache_id(s
->memcg_params
->memcg
));
5183 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
5187 static int sysfs_slab_add(struct kmem_cache
*s
)
5191 int unmergeable
= slab_unmergeable(s
);
5195 * Slabcache can never be merged so we can use the name proper.
5196 * This is typically the case for debug situations. In that
5197 * case we can catch duplicate names easily.
5199 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
5203 * Create a unique name for the slab as a target
5206 name
= create_unique_id(s
);
5209 s
->kobj
.kset
= cache_kset(s
);
5210 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, "%s", name
);
5214 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
5218 #ifdef CONFIG_MEMCG_KMEM
5219 if (is_root_cache(s
)) {
5220 s
->memcg_kset
= kset_create_and_add("cgroup", NULL
, &s
->kobj
);
5221 if (!s
->memcg_kset
) {
5228 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
5230 /* Setup first alias */
5231 sysfs_slab_alias(s
, s
->name
);
5238 kobject_del(&s
->kobj
);
5240 kobject_put(&s
->kobj
);
5244 void sysfs_slab_remove(struct kmem_cache
*s
)
5246 if (slab_state
< FULL
)
5248 * Sysfs has not been setup yet so no need to remove the
5253 #ifdef CONFIG_MEMCG_KMEM
5254 kset_unregister(s
->memcg_kset
);
5256 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
5257 kobject_del(&s
->kobj
);
5258 kobject_put(&s
->kobj
);
5262 * Need to buffer aliases during bootup until sysfs becomes
5263 * available lest we lose that information.
5265 struct saved_alias
{
5266 struct kmem_cache
*s
;
5268 struct saved_alias
*next
;
5271 static struct saved_alias
*alias_list
;
5273 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
5275 struct saved_alias
*al
;
5277 if (slab_state
== FULL
) {
5279 * If we have a leftover link then remove it.
5281 sysfs_remove_link(&slab_kset
->kobj
, name
);
5282 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
5285 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
5291 al
->next
= alias_list
;
5296 static int __init
slab_sysfs_init(void)
5298 struct kmem_cache
*s
;
5301 mutex_lock(&slab_mutex
);
5303 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
5305 mutex_unlock(&slab_mutex
);
5306 printk(KERN_ERR
"Cannot register slab subsystem.\n");
5312 list_for_each_entry(s
, &slab_caches
, list
) {
5313 err
= sysfs_slab_add(s
);
5315 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
5316 " to sysfs\n", s
->name
);
5319 while (alias_list
) {
5320 struct saved_alias
*al
= alias_list
;
5322 alias_list
= alias_list
->next
;
5323 err
= sysfs_slab_alias(al
->s
, al
->name
);
5325 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
5326 " %s to sysfs\n", al
->name
);
5330 mutex_unlock(&slab_mutex
);
5335 __initcall(slab_sysfs_init
);
5336 #endif /* CONFIG_SYSFS */
5339 * The /proc/slabinfo ABI
5341 #ifdef CONFIG_SLABINFO
5342 void get_slabinfo(struct kmem_cache
*s
, struct slabinfo
*sinfo
)
5344 unsigned long nr_slabs
= 0;
5345 unsigned long nr_objs
= 0;
5346 unsigned long nr_free
= 0;
5349 for_each_online_node(node
) {
5350 struct kmem_cache_node
*n
= get_node(s
, node
);
5355 nr_slabs
+= node_nr_slabs(n
);
5356 nr_objs
+= node_nr_objs(n
);
5357 nr_free
+= count_partial(n
, count_free
);
5360 sinfo
->active_objs
= nr_objs
- nr_free
;
5361 sinfo
->num_objs
= nr_objs
;
5362 sinfo
->active_slabs
= nr_slabs
;
5363 sinfo
->num_slabs
= nr_slabs
;
5364 sinfo
->objects_per_slab
= oo_objects(s
->oo
);
5365 sinfo
->cache_order
= oo_order(s
->oo
);
5368 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*s
)
5372 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
5373 size_t count
, loff_t
*ppos
)
5377 #endif /* CONFIG_SLABINFO */