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 sysfs_slab_remove(struct kmem_cache
*);
214 static void memcg_propagate_slab_attrs(struct kmem_cache
*s
);
216 static inline int sysfs_slab_add(struct kmem_cache
*s
) { return 0; }
217 static inline int sysfs_slab_alias(struct kmem_cache
*s
, const char *p
)
219 static inline void sysfs_slab_remove(struct kmem_cache
*s
) { }
221 static inline void memcg_propagate_slab_attrs(struct kmem_cache
*s
) { }
224 static inline void stat(const struct kmem_cache
*s
, enum stat_item si
)
226 #ifdef CONFIG_SLUB_STATS
228 * The rmw is racy on a preemptible kernel but this is acceptable, so
229 * avoid this_cpu_add()'s irq-disable overhead.
231 raw_cpu_inc(s
->cpu_slab
->stat
[si
]);
235 /********************************************************************
236 * Core slab cache functions
237 *******************************************************************/
239 static inline struct kmem_cache_node
*get_node(struct kmem_cache
*s
, int node
)
241 return s
->node
[node
];
244 /* Verify that a pointer has an address that is valid within a slab page */
245 static inline int check_valid_pointer(struct kmem_cache
*s
,
246 struct page
*page
, const void *object
)
253 base
= page_address(page
);
254 if (object
< base
|| object
>= base
+ page
->objects
* s
->size
||
255 (object
- base
) % s
->size
) {
262 static inline void *get_freepointer(struct kmem_cache
*s
, void *object
)
264 return *(void **)(object
+ s
->offset
);
267 static void prefetch_freepointer(const struct kmem_cache
*s
, void *object
)
269 prefetch(object
+ s
->offset
);
272 static inline void *get_freepointer_safe(struct kmem_cache
*s
, void *object
)
276 #ifdef CONFIG_DEBUG_PAGEALLOC
277 probe_kernel_read(&p
, (void **)(object
+ s
->offset
), sizeof(p
));
279 p
= get_freepointer(s
, object
);
284 static inline void set_freepointer(struct kmem_cache
*s
, void *object
, void *fp
)
286 *(void **)(object
+ s
->offset
) = fp
;
289 /* Loop over all objects in a slab */
290 #define for_each_object(__p, __s, __addr, __objects) \
291 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
294 /* Determine object index from a given position */
295 static inline int slab_index(void *p
, struct kmem_cache
*s
, void *addr
)
297 return (p
- addr
) / s
->size
;
300 static inline size_t slab_ksize(const struct kmem_cache
*s
)
302 #ifdef CONFIG_SLUB_DEBUG
304 * Debugging requires use of the padding between object
305 * and whatever may come after it.
307 if (s
->flags
& (SLAB_RED_ZONE
| SLAB_POISON
))
308 return s
->object_size
;
312 * If we have the need to store the freelist pointer
313 * back there or track user information then we can
314 * only use the space before that information.
316 if (s
->flags
& (SLAB_DESTROY_BY_RCU
| SLAB_STORE_USER
))
319 * Else we can use all the padding etc for the allocation
324 static inline int order_objects(int order
, unsigned long size
, int reserved
)
326 return ((PAGE_SIZE
<< order
) - reserved
) / size
;
329 static inline struct kmem_cache_order_objects
oo_make(int order
,
330 unsigned long size
, int reserved
)
332 struct kmem_cache_order_objects x
= {
333 (order
<< OO_SHIFT
) + order_objects(order
, size
, reserved
)
339 static inline int oo_order(struct kmem_cache_order_objects x
)
341 return x
.x
>> OO_SHIFT
;
344 static inline int oo_objects(struct kmem_cache_order_objects x
)
346 return x
.x
& OO_MASK
;
350 * Per slab locking using the pagelock
352 static __always_inline
void slab_lock(struct page
*page
)
354 bit_spin_lock(PG_locked
, &page
->flags
);
357 static __always_inline
void slab_unlock(struct page
*page
)
359 __bit_spin_unlock(PG_locked
, &page
->flags
);
362 static inline void set_page_slub_counters(struct page
*page
, unsigned long counters_new
)
365 tmp
.counters
= counters_new
;
367 * page->counters can cover frozen/inuse/objects as well
368 * as page->_count. If we assign to ->counters directly
369 * we run the risk of losing updates to page->_count, so
370 * be careful and only assign to the fields we need.
372 page
->frozen
= tmp
.frozen
;
373 page
->inuse
= tmp
.inuse
;
374 page
->objects
= tmp
.objects
;
377 /* Interrupts must be disabled (for the fallback code to work right) */
378 static inline bool __cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
379 void *freelist_old
, unsigned long counters_old
,
380 void *freelist_new
, unsigned long counters_new
,
383 VM_BUG_ON(!irqs_disabled());
384 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
385 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
386 if (s
->flags
& __CMPXCHG_DOUBLE
) {
387 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
388 freelist_old
, counters_old
,
389 freelist_new
, counters_new
))
395 if (page
->freelist
== freelist_old
&&
396 page
->counters
== counters_old
) {
397 page
->freelist
= freelist_new
;
398 set_page_slub_counters(page
, counters_new
);
406 stat(s
, CMPXCHG_DOUBLE_FAIL
);
408 #ifdef SLUB_DEBUG_CMPXCHG
409 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
415 static inline bool cmpxchg_double_slab(struct kmem_cache
*s
, struct page
*page
,
416 void *freelist_old
, unsigned long counters_old
,
417 void *freelist_new
, unsigned long counters_new
,
420 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
421 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
422 if (s
->flags
& __CMPXCHG_DOUBLE
) {
423 if (cmpxchg_double(&page
->freelist
, &page
->counters
,
424 freelist_old
, counters_old
,
425 freelist_new
, counters_new
))
432 local_irq_save(flags
);
434 if (page
->freelist
== freelist_old
&&
435 page
->counters
== counters_old
) {
436 page
->freelist
= freelist_new
;
437 set_page_slub_counters(page
, counters_new
);
439 local_irq_restore(flags
);
443 local_irq_restore(flags
);
447 stat(s
, CMPXCHG_DOUBLE_FAIL
);
449 #ifdef SLUB_DEBUG_CMPXCHG
450 printk(KERN_INFO
"%s %s: cmpxchg double redo ", n
, s
->name
);
456 #ifdef CONFIG_SLUB_DEBUG
458 * Determine a map of object in use on a page.
460 * Node listlock must be held to guarantee that the page does
461 * not vanish from under us.
463 static void get_map(struct kmem_cache
*s
, struct page
*page
, unsigned long *map
)
466 void *addr
= page_address(page
);
468 for (p
= page
->freelist
; p
; p
= get_freepointer(s
, p
))
469 set_bit(slab_index(p
, s
, addr
), map
);
475 #ifdef CONFIG_SLUB_DEBUG_ON
476 static int slub_debug
= DEBUG_DEFAULT_FLAGS
;
478 static int slub_debug
;
481 static char *slub_debug_slabs
;
482 static int disable_higher_order_debug
;
487 static void print_section(char *text
, u8
*addr
, unsigned int length
)
489 print_hex_dump(KERN_ERR
, text
, DUMP_PREFIX_ADDRESS
, 16, 1, addr
,
493 static struct track
*get_track(struct kmem_cache
*s
, void *object
,
494 enum track_item alloc
)
499 p
= object
+ s
->offset
+ sizeof(void *);
501 p
= object
+ s
->inuse
;
506 static void set_track(struct kmem_cache
*s
, void *object
,
507 enum track_item alloc
, unsigned long addr
)
509 struct track
*p
= get_track(s
, object
, alloc
);
512 #ifdef CONFIG_STACKTRACE
513 struct stack_trace trace
;
516 trace
.nr_entries
= 0;
517 trace
.max_entries
= TRACK_ADDRS_COUNT
;
518 trace
.entries
= p
->addrs
;
520 save_stack_trace(&trace
);
522 /* See rant in lockdep.c */
523 if (trace
.nr_entries
!= 0 &&
524 trace
.entries
[trace
.nr_entries
- 1] == ULONG_MAX
)
527 for (i
= trace
.nr_entries
; i
< TRACK_ADDRS_COUNT
; i
++)
531 p
->cpu
= smp_processor_id();
532 p
->pid
= current
->pid
;
535 memset(p
, 0, sizeof(struct track
));
538 static void init_tracking(struct kmem_cache
*s
, void *object
)
540 if (!(s
->flags
& SLAB_STORE_USER
))
543 set_track(s
, object
, TRACK_FREE
, 0UL);
544 set_track(s
, object
, TRACK_ALLOC
, 0UL);
547 static void print_track(const char *s
, struct track
*t
)
552 printk(KERN_ERR
"INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
553 s
, (void *)t
->addr
, jiffies
- t
->when
, t
->cpu
, t
->pid
);
554 #ifdef CONFIG_STACKTRACE
557 for (i
= 0; i
< TRACK_ADDRS_COUNT
; i
++)
559 printk(KERN_ERR
"\t%pS\n", (void *)t
->addrs
[i
]);
566 static void print_tracking(struct kmem_cache
*s
, void *object
)
568 if (!(s
->flags
& SLAB_STORE_USER
))
571 print_track("Allocated", get_track(s
, object
, TRACK_ALLOC
));
572 print_track("Freed", get_track(s
, object
, TRACK_FREE
));
575 static void print_page_info(struct page
*page
)
578 "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
579 page
, page
->objects
, page
->inuse
, page
->freelist
, page
->flags
);
583 static void slab_bug(struct kmem_cache
*s
, char *fmt
, ...)
589 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
591 printk(KERN_ERR
"========================================"
592 "=====================================\n");
593 printk(KERN_ERR
"BUG %s (%s): %s\n", s
->name
, print_tainted(), buf
);
594 printk(KERN_ERR
"----------------------------------------"
595 "-------------------------------------\n\n");
597 add_taint(TAINT_BAD_PAGE
, LOCKDEP_NOW_UNRELIABLE
);
600 static void slab_fix(struct kmem_cache
*s
, char *fmt
, ...)
606 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
608 printk(KERN_ERR
"FIX %s: %s\n", s
->name
, buf
);
611 static void print_trailer(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
613 unsigned int off
; /* Offset of last byte */
614 u8
*addr
= page_address(page
);
616 print_tracking(s
, p
);
618 print_page_info(page
);
620 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
621 p
, p
- addr
, get_freepointer(s
, p
));
624 print_section("Bytes b4 ", p
- 16, 16);
626 print_section("Object ", p
, min_t(unsigned long, s
->object_size
,
628 if (s
->flags
& SLAB_RED_ZONE
)
629 print_section("Redzone ", p
+ s
->object_size
,
630 s
->inuse
- s
->object_size
);
633 off
= s
->offset
+ sizeof(void *);
637 if (s
->flags
& SLAB_STORE_USER
)
638 off
+= 2 * sizeof(struct track
);
641 /* Beginning of the filler is the free pointer */
642 print_section("Padding ", p
+ off
, s
->size
- off
);
647 static void object_err(struct kmem_cache
*s
, struct page
*page
,
648 u8
*object
, char *reason
)
650 slab_bug(s
, "%s", reason
);
651 print_trailer(s
, page
, object
);
654 static void slab_err(struct kmem_cache
*s
, struct page
*page
,
655 const char *fmt
, ...)
661 vsnprintf(buf
, sizeof(buf
), fmt
, args
);
663 slab_bug(s
, "%s", buf
);
664 print_page_info(page
);
668 static void init_object(struct kmem_cache
*s
, void *object
, u8 val
)
672 if (s
->flags
& __OBJECT_POISON
) {
673 memset(p
, POISON_FREE
, s
->object_size
- 1);
674 p
[s
->object_size
- 1] = POISON_END
;
677 if (s
->flags
& SLAB_RED_ZONE
)
678 memset(p
+ s
->object_size
, val
, s
->inuse
- s
->object_size
);
681 static void restore_bytes(struct kmem_cache
*s
, char *message
, u8 data
,
682 void *from
, void *to
)
684 slab_fix(s
, "Restoring 0x%p-0x%p=0x%x\n", from
, to
- 1, data
);
685 memset(from
, data
, to
- from
);
688 static int check_bytes_and_report(struct kmem_cache
*s
, struct page
*page
,
689 u8
*object
, char *what
,
690 u8
*start
, unsigned int value
, unsigned int bytes
)
695 fault
= memchr_inv(start
, value
, bytes
);
700 while (end
> fault
&& end
[-1] == value
)
703 slab_bug(s
, "%s overwritten", what
);
704 printk(KERN_ERR
"INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
705 fault
, end
- 1, fault
[0], value
);
706 print_trailer(s
, page
, object
);
708 restore_bytes(s
, what
, value
, fault
, end
);
716 * Bytes of the object to be managed.
717 * If the freepointer may overlay the object then the free
718 * pointer is the first word of the object.
720 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
723 * object + s->object_size
724 * Padding to reach word boundary. This is also used for Redzoning.
725 * Padding is extended by another word if Redzoning is enabled and
726 * object_size == inuse.
728 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
729 * 0xcc (RED_ACTIVE) for objects in use.
732 * Meta data starts here.
734 * A. Free pointer (if we cannot overwrite object on free)
735 * B. Tracking data for SLAB_STORE_USER
736 * C. Padding to reach required alignment boundary or at mininum
737 * one word if debugging is on to be able to detect writes
738 * before the word boundary.
740 * Padding is done using 0x5a (POISON_INUSE)
743 * Nothing is used beyond s->size.
745 * If slabcaches are merged then the object_size and inuse boundaries are mostly
746 * ignored. And therefore no slab options that rely on these boundaries
747 * may be used with merged slabcaches.
750 static int check_pad_bytes(struct kmem_cache
*s
, struct page
*page
, u8
*p
)
752 unsigned long off
= s
->inuse
; /* The end of info */
755 /* Freepointer is placed after the object. */
756 off
+= sizeof(void *);
758 if (s
->flags
& SLAB_STORE_USER
)
759 /* We also have user information there */
760 off
+= 2 * sizeof(struct track
);
765 return check_bytes_and_report(s
, page
, p
, "Object padding",
766 p
+ off
, POISON_INUSE
, s
->size
- off
);
769 /* Check the pad bytes at the end of a slab page */
770 static int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
778 if (!(s
->flags
& SLAB_POISON
))
781 start
= page_address(page
);
782 length
= (PAGE_SIZE
<< compound_order(page
)) - s
->reserved
;
783 end
= start
+ length
;
784 remainder
= length
% s
->size
;
788 fault
= memchr_inv(end
- remainder
, POISON_INUSE
, remainder
);
791 while (end
> fault
&& end
[-1] == POISON_INUSE
)
794 slab_err(s
, page
, "Padding overwritten. 0x%p-0x%p", fault
, end
- 1);
795 print_section("Padding ", end
- remainder
, remainder
);
797 restore_bytes(s
, "slab padding", POISON_INUSE
, end
- remainder
, end
);
801 static int check_object(struct kmem_cache
*s
, struct page
*page
,
802 void *object
, u8 val
)
805 u8
*endobject
= object
+ s
->object_size
;
807 if (s
->flags
& SLAB_RED_ZONE
) {
808 if (!check_bytes_and_report(s
, page
, object
, "Redzone",
809 endobject
, val
, s
->inuse
- s
->object_size
))
812 if ((s
->flags
& SLAB_POISON
) && s
->object_size
< s
->inuse
) {
813 check_bytes_and_report(s
, page
, p
, "Alignment padding",
814 endobject
, POISON_INUSE
,
815 s
->inuse
- s
->object_size
);
819 if (s
->flags
& SLAB_POISON
) {
820 if (val
!= SLUB_RED_ACTIVE
&& (s
->flags
& __OBJECT_POISON
) &&
821 (!check_bytes_and_report(s
, page
, p
, "Poison", p
,
822 POISON_FREE
, s
->object_size
- 1) ||
823 !check_bytes_and_report(s
, page
, p
, "Poison",
824 p
+ s
->object_size
- 1, POISON_END
, 1)))
827 * check_pad_bytes cleans up on its own.
829 check_pad_bytes(s
, page
, p
);
832 if (!s
->offset
&& val
== SLUB_RED_ACTIVE
)
834 * Object and freepointer overlap. Cannot check
835 * freepointer while object is allocated.
839 /* Check free pointer validity */
840 if (!check_valid_pointer(s
, page
, get_freepointer(s
, p
))) {
841 object_err(s
, page
, p
, "Freepointer corrupt");
843 * No choice but to zap it and thus lose the remainder
844 * of the free objects in this slab. May cause
845 * another error because the object count is now wrong.
847 set_freepointer(s
, p
, NULL
);
853 static int check_slab(struct kmem_cache
*s
, struct page
*page
)
857 VM_BUG_ON(!irqs_disabled());
859 if (!PageSlab(page
)) {
860 slab_err(s
, page
, "Not a valid slab page");
864 maxobj
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
865 if (page
->objects
> maxobj
) {
866 slab_err(s
, page
, "objects %u > max %u",
867 s
->name
, page
->objects
, maxobj
);
870 if (page
->inuse
> page
->objects
) {
871 slab_err(s
, page
, "inuse %u > max %u",
872 s
->name
, page
->inuse
, page
->objects
);
875 /* Slab_pad_check fixes things up after itself */
876 slab_pad_check(s
, page
);
881 * Determine if a certain object on a page is on the freelist. Must hold the
882 * slab lock to guarantee that the chains are in a consistent state.
884 static int on_freelist(struct kmem_cache
*s
, struct page
*page
, void *search
)
889 unsigned long max_objects
;
892 while (fp
&& nr
<= page
->objects
) {
895 if (!check_valid_pointer(s
, page
, fp
)) {
897 object_err(s
, page
, object
,
898 "Freechain corrupt");
899 set_freepointer(s
, object
, NULL
);
901 slab_err(s
, page
, "Freepointer corrupt");
902 page
->freelist
= NULL
;
903 page
->inuse
= page
->objects
;
904 slab_fix(s
, "Freelist cleared");
910 fp
= get_freepointer(s
, object
);
914 max_objects
= order_objects(compound_order(page
), s
->size
, s
->reserved
);
915 if (max_objects
> MAX_OBJS_PER_PAGE
)
916 max_objects
= MAX_OBJS_PER_PAGE
;
918 if (page
->objects
!= max_objects
) {
919 slab_err(s
, page
, "Wrong number of objects. Found %d but "
920 "should be %d", page
->objects
, max_objects
);
921 page
->objects
= max_objects
;
922 slab_fix(s
, "Number of objects adjusted.");
924 if (page
->inuse
!= page
->objects
- nr
) {
925 slab_err(s
, page
, "Wrong object count. Counter is %d but "
926 "counted were %d", page
->inuse
, page
->objects
- nr
);
927 page
->inuse
= page
->objects
- nr
;
928 slab_fix(s
, "Object count adjusted.");
930 return search
== NULL
;
933 static void trace(struct kmem_cache
*s
, struct page
*page
, void *object
,
936 if (s
->flags
& SLAB_TRACE
) {
937 printk(KERN_INFO
"TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
939 alloc
? "alloc" : "free",
944 print_section("Object ", (void *)object
,
952 * Hooks for other subsystems that check memory allocations. In a typical
953 * production configuration these hooks all should produce no code at all.
955 static inline void kmalloc_large_node_hook(void *ptr
, size_t size
, gfp_t flags
)
957 kmemleak_alloc(ptr
, size
, 1, flags
);
960 static inline void kfree_hook(const void *x
)
965 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
967 flags
&= gfp_allowed_mask
;
968 lockdep_trace_alloc(flags
);
969 might_sleep_if(flags
& __GFP_WAIT
);
971 return should_failslab(s
->object_size
, flags
, s
->flags
);
974 static inline void slab_post_alloc_hook(struct kmem_cache
*s
,
975 gfp_t flags
, void *object
)
977 flags
&= gfp_allowed_mask
;
978 kmemcheck_slab_alloc(s
, flags
, object
, slab_ksize(s
));
979 kmemleak_alloc_recursive(object
, s
->object_size
, 1, s
->flags
, flags
);
982 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
)
984 kmemleak_free_recursive(x
, s
->flags
);
987 * Trouble is that we may no longer disable interrupts in the fast path
988 * So in order to make the debug calls that expect irqs to be
989 * disabled we need to disable interrupts temporarily.
991 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
995 local_irq_save(flags
);
996 kmemcheck_slab_free(s
, x
, s
->object_size
);
997 debug_check_no_locks_freed(x
, s
->object_size
);
998 local_irq_restore(flags
);
1001 if (!(s
->flags
& SLAB_DEBUG_OBJECTS
))
1002 debug_check_no_obj_freed(x
, s
->object_size
);
1006 * Tracking of fully allocated slabs for debugging purposes.
1008 static void add_full(struct kmem_cache
*s
,
1009 struct kmem_cache_node
*n
, struct page
*page
)
1011 if (!(s
->flags
& SLAB_STORE_USER
))
1014 lockdep_assert_held(&n
->list_lock
);
1015 list_add(&page
->lru
, &n
->full
);
1018 static void remove_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
, struct page
*page
)
1020 if (!(s
->flags
& SLAB_STORE_USER
))
1023 lockdep_assert_held(&n
->list_lock
);
1024 list_del(&page
->lru
);
1027 /* Tracking of the number of slabs for debugging purposes */
1028 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1030 struct kmem_cache_node
*n
= get_node(s
, node
);
1032 return atomic_long_read(&n
->nr_slabs
);
1035 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1037 return atomic_long_read(&n
->nr_slabs
);
1040 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1042 struct kmem_cache_node
*n
= get_node(s
, node
);
1045 * May be called early in order to allocate a slab for the
1046 * kmem_cache_node structure. Solve the chicken-egg
1047 * dilemma by deferring the increment of the count during
1048 * bootstrap (see early_kmem_cache_node_alloc).
1051 atomic_long_inc(&n
->nr_slabs
);
1052 atomic_long_add(objects
, &n
->total_objects
);
1055 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
, int objects
)
1057 struct kmem_cache_node
*n
= get_node(s
, node
);
1059 atomic_long_dec(&n
->nr_slabs
);
1060 atomic_long_sub(objects
, &n
->total_objects
);
1063 /* Object debug checks for alloc/free paths */
1064 static void setup_object_debug(struct kmem_cache
*s
, struct page
*page
,
1067 if (!(s
->flags
& (SLAB_STORE_USER
|SLAB_RED_ZONE
|__OBJECT_POISON
)))
1070 init_object(s
, object
, SLUB_RED_INACTIVE
);
1071 init_tracking(s
, object
);
1074 static noinline
int alloc_debug_processing(struct kmem_cache
*s
,
1076 void *object
, unsigned long addr
)
1078 if (!check_slab(s
, page
))
1081 if (!check_valid_pointer(s
, page
, object
)) {
1082 object_err(s
, page
, object
, "Freelist Pointer check fails");
1086 if (!check_object(s
, page
, object
, SLUB_RED_INACTIVE
))
1089 /* Success perform special debug activities for allocs */
1090 if (s
->flags
& SLAB_STORE_USER
)
1091 set_track(s
, object
, TRACK_ALLOC
, addr
);
1092 trace(s
, page
, object
, 1);
1093 init_object(s
, object
, SLUB_RED_ACTIVE
);
1097 if (PageSlab(page
)) {
1099 * If this is a slab page then lets do the best we can
1100 * to avoid issues in the future. Marking all objects
1101 * as used avoids touching the remaining objects.
1103 slab_fix(s
, "Marking all objects used");
1104 page
->inuse
= page
->objects
;
1105 page
->freelist
= NULL
;
1110 static noinline
struct kmem_cache_node
*free_debug_processing(
1111 struct kmem_cache
*s
, struct page
*page
, void *object
,
1112 unsigned long addr
, unsigned long *flags
)
1114 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1116 spin_lock_irqsave(&n
->list_lock
, *flags
);
1119 if (!check_slab(s
, page
))
1122 if (!check_valid_pointer(s
, page
, object
)) {
1123 slab_err(s
, page
, "Invalid object pointer 0x%p", object
);
1127 if (on_freelist(s
, page
, object
)) {
1128 object_err(s
, page
, object
, "Object already free");
1132 if (!check_object(s
, page
, object
, SLUB_RED_ACTIVE
))
1135 if (unlikely(s
!= page
->slab_cache
)) {
1136 if (!PageSlab(page
)) {
1137 slab_err(s
, page
, "Attempt to free object(0x%p) "
1138 "outside of slab", object
);
1139 } else if (!page
->slab_cache
) {
1141 "SLUB <none>: no slab for object 0x%p.\n",
1145 object_err(s
, page
, object
,
1146 "page slab pointer corrupt.");
1150 if (s
->flags
& SLAB_STORE_USER
)
1151 set_track(s
, object
, TRACK_FREE
, addr
);
1152 trace(s
, page
, object
, 0);
1153 init_object(s
, object
, SLUB_RED_INACTIVE
);
1157 * Keep node_lock to preserve integrity
1158 * until the object is actually freed
1164 spin_unlock_irqrestore(&n
->list_lock
, *flags
);
1165 slab_fix(s
, "Object at 0x%p not freed", object
);
1169 static int __init
setup_slub_debug(char *str
)
1171 slub_debug
= DEBUG_DEFAULT_FLAGS
;
1172 if (*str
++ != '=' || !*str
)
1174 * No options specified. Switch on full debugging.
1180 * No options but restriction on slabs. This means full
1181 * debugging for slabs matching a pattern.
1185 if (tolower(*str
) == 'o') {
1187 * Avoid enabling debugging on caches if its minimum order
1188 * would increase as a result.
1190 disable_higher_order_debug
= 1;
1197 * Switch off all debugging measures.
1202 * Determine which debug features should be switched on
1204 for (; *str
&& *str
!= ','; str
++) {
1205 switch (tolower(*str
)) {
1207 slub_debug
|= SLAB_DEBUG_FREE
;
1210 slub_debug
|= SLAB_RED_ZONE
;
1213 slub_debug
|= SLAB_POISON
;
1216 slub_debug
|= SLAB_STORE_USER
;
1219 slub_debug
|= SLAB_TRACE
;
1222 slub_debug
|= SLAB_FAILSLAB
;
1225 printk(KERN_ERR
"slub_debug option '%c' "
1226 "unknown. skipped\n", *str
);
1232 slub_debug_slabs
= str
+ 1;
1237 __setup("slub_debug", setup_slub_debug
);
1239 static unsigned long kmem_cache_flags(unsigned long object_size
,
1240 unsigned long flags
, const char *name
,
1241 void (*ctor
)(void *))
1244 * Enable debugging if selected on the kernel commandline.
1246 if (slub_debug
&& (!slub_debug_slabs
|| (name
&&
1247 !strncmp(slub_debug_slabs
, name
, strlen(slub_debug_slabs
)))))
1248 flags
|= slub_debug
;
1253 static inline void setup_object_debug(struct kmem_cache
*s
,
1254 struct page
*page
, void *object
) {}
1256 static inline int alloc_debug_processing(struct kmem_cache
*s
,
1257 struct page
*page
, void *object
, unsigned long addr
) { return 0; }
1259 static inline struct kmem_cache_node
*free_debug_processing(
1260 struct kmem_cache
*s
, struct page
*page
, void *object
,
1261 unsigned long addr
, unsigned long *flags
) { return NULL
; }
1263 static inline int slab_pad_check(struct kmem_cache
*s
, struct page
*page
)
1265 static inline int check_object(struct kmem_cache
*s
, struct page
*page
,
1266 void *object
, u8 val
) { return 1; }
1267 static inline void add_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1268 struct page
*page
) {}
1269 static inline void remove_full(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1270 struct page
*page
) {}
1271 static inline unsigned long kmem_cache_flags(unsigned long object_size
,
1272 unsigned long flags
, const char *name
,
1273 void (*ctor
)(void *))
1277 #define slub_debug 0
1279 #define disable_higher_order_debug 0
1281 static inline unsigned long slabs_node(struct kmem_cache
*s
, int node
)
1283 static inline unsigned long node_nr_slabs(struct kmem_cache_node
*n
)
1285 static inline void inc_slabs_node(struct kmem_cache
*s
, int node
,
1287 static inline void dec_slabs_node(struct kmem_cache
*s
, int node
,
1290 static inline void kmalloc_large_node_hook(void *ptr
, size_t size
, gfp_t flags
)
1292 kmemleak_alloc(ptr
, size
, 1, flags
);
1295 static inline void kfree_hook(const void *x
)
1300 static inline int slab_pre_alloc_hook(struct kmem_cache
*s
, gfp_t flags
)
1303 static inline void slab_post_alloc_hook(struct kmem_cache
*s
, gfp_t flags
,
1306 kmemleak_alloc_recursive(object
, s
->object_size
, 1, s
->flags
,
1307 flags
& gfp_allowed_mask
);
1310 static inline void slab_free_hook(struct kmem_cache
*s
, void *x
)
1312 kmemleak_free_recursive(x
, s
->flags
);
1315 #endif /* CONFIG_SLUB_DEBUG */
1318 * Slab allocation and freeing
1320 static inline struct page
*alloc_slab_page(gfp_t flags
, int node
,
1321 struct kmem_cache_order_objects oo
)
1323 int order
= oo_order(oo
);
1325 flags
|= __GFP_NOTRACK
;
1327 if (node
== NUMA_NO_NODE
)
1328 return alloc_pages(flags
, order
);
1330 return alloc_pages_exact_node(node
, flags
, order
);
1333 static struct page
*allocate_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1336 struct kmem_cache_order_objects oo
= s
->oo
;
1339 flags
&= gfp_allowed_mask
;
1341 if (flags
& __GFP_WAIT
)
1344 flags
|= s
->allocflags
;
1347 * Let the initial higher-order allocation fail under memory pressure
1348 * so we fall-back to the minimum order allocation.
1350 alloc_gfp
= (flags
| __GFP_NOWARN
| __GFP_NORETRY
) & ~__GFP_NOFAIL
;
1352 page
= alloc_slab_page(alloc_gfp
, node
, oo
);
1353 if (unlikely(!page
)) {
1356 * Allocation may have failed due to fragmentation.
1357 * Try a lower order alloc if possible
1359 page
= alloc_slab_page(flags
, node
, oo
);
1362 stat(s
, ORDER_FALLBACK
);
1365 if (kmemcheck_enabled
&& page
1366 && !(s
->flags
& (SLAB_NOTRACK
| DEBUG_DEFAULT_FLAGS
))) {
1367 int pages
= 1 << oo_order(oo
);
1369 kmemcheck_alloc_shadow(page
, oo_order(oo
), flags
, node
);
1372 * Objects from caches that have a constructor don't get
1373 * cleared when they're allocated, so we need to do it here.
1376 kmemcheck_mark_uninitialized_pages(page
, pages
);
1378 kmemcheck_mark_unallocated_pages(page
, pages
);
1381 if (flags
& __GFP_WAIT
)
1382 local_irq_disable();
1386 page
->objects
= oo_objects(oo
);
1387 mod_zone_page_state(page_zone(page
),
1388 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1389 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1395 static void setup_object(struct kmem_cache
*s
, struct page
*page
,
1398 setup_object_debug(s
, page
, object
);
1399 if (unlikely(s
->ctor
))
1403 static struct page
*new_slab(struct kmem_cache
*s
, gfp_t flags
, int node
)
1411 BUG_ON(flags
& GFP_SLAB_BUG_MASK
);
1413 page
= allocate_slab(s
,
1414 flags
& (GFP_RECLAIM_MASK
| GFP_CONSTRAINT_MASK
), node
);
1418 order
= compound_order(page
);
1419 inc_slabs_node(s
, page_to_nid(page
), page
->objects
);
1420 memcg_bind_pages(s
, order
);
1421 page
->slab_cache
= s
;
1422 __SetPageSlab(page
);
1423 if (page
->pfmemalloc
)
1424 SetPageSlabPfmemalloc(page
);
1426 start
= page_address(page
);
1428 if (unlikely(s
->flags
& SLAB_POISON
))
1429 memset(start
, POISON_INUSE
, PAGE_SIZE
<< order
);
1432 for_each_object(p
, s
, start
, page
->objects
) {
1433 setup_object(s
, page
, last
);
1434 set_freepointer(s
, last
, p
);
1437 setup_object(s
, page
, last
);
1438 set_freepointer(s
, last
, NULL
);
1440 page
->freelist
= start
;
1441 page
->inuse
= page
->objects
;
1447 static void __free_slab(struct kmem_cache
*s
, struct page
*page
)
1449 int order
= compound_order(page
);
1450 int pages
= 1 << order
;
1452 if (kmem_cache_debug(s
)) {
1455 slab_pad_check(s
, page
);
1456 for_each_object(p
, s
, page_address(page
),
1458 check_object(s
, page
, p
, SLUB_RED_INACTIVE
);
1461 kmemcheck_free_shadow(page
, compound_order(page
));
1463 mod_zone_page_state(page_zone(page
),
1464 (s
->flags
& SLAB_RECLAIM_ACCOUNT
) ?
1465 NR_SLAB_RECLAIMABLE
: NR_SLAB_UNRECLAIMABLE
,
1468 __ClearPageSlabPfmemalloc(page
);
1469 __ClearPageSlab(page
);
1471 memcg_release_pages(s
, order
);
1472 page_mapcount_reset(page
);
1473 if (current
->reclaim_state
)
1474 current
->reclaim_state
->reclaimed_slab
+= pages
;
1475 __free_memcg_kmem_pages(page
, order
);
1478 #define need_reserve_slab_rcu \
1479 (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
1481 static void rcu_free_slab(struct rcu_head
*h
)
1485 if (need_reserve_slab_rcu
)
1486 page
= virt_to_head_page(h
);
1488 page
= container_of((struct list_head
*)h
, struct page
, lru
);
1490 __free_slab(page
->slab_cache
, page
);
1493 static void free_slab(struct kmem_cache
*s
, struct page
*page
)
1495 if (unlikely(s
->flags
& SLAB_DESTROY_BY_RCU
)) {
1496 struct rcu_head
*head
;
1498 if (need_reserve_slab_rcu
) {
1499 int order
= compound_order(page
);
1500 int offset
= (PAGE_SIZE
<< order
) - s
->reserved
;
1502 VM_BUG_ON(s
->reserved
!= sizeof(*head
));
1503 head
= page_address(page
) + offset
;
1506 * RCU free overloads the RCU head over the LRU
1508 head
= (void *)&page
->lru
;
1511 call_rcu(head
, rcu_free_slab
);
1513 __free_slab(s
, page
);
1516 static void discard_slab(struct kmem_cache
*s
, struct page
*page
)
1518 dec_slabs_node(s
, page_to_nid(page
), page
->objects
);
1523 * Management of partially allocated slabs.
1526 __add_partial(struct kmem_cache_node
*n
, struct page
*page
, int tail
)
1529 if (tail
== DEACTIVATE_TO_TAIL
)
1530 list_add_tail(&page
->lru
, &n
->partial
);
1532 list_add(&page
->lru
, &n
->partial
);
1535 static inline void add_partial(struct kmem_cache_node
*n
,
1536 struct page
*page
, int tail
)
1538 lockdep_assert_held(&n
->list_lock
);
1539 __add_partial(n
, page
, tail
);
1543 __remove_partial(struct kmem_cache_node
*n
, struct page
*page
)
1545 list_del(&page
->lru
);
1549 static inline void remove_partial(struct kmem_cache_node
*n
,
1552 lockdep_assert_held(&n
->list_lock
);
1553 __remove_partial(n
, page
);
1557 * Remove slab from the partial list, freeze it and
1558 * return the pointer to the freelist.
1560 * Returns a list of objects or NULL if it fails.
1562 static inline void *acquire_slab(struct kmem_cache
*s
,
1563 struct kmem_cache_node
*n
, struct page
*page
,
1564 int mode
, int *objects
)
1567 unsigned long counters
;
1570 lockdep_assert_held(&n
->list_lock
);
1573 * Zap the freelist and set the frozen bit.
1574 * The old freelist is the list of objects for the
1575 * per cpu allocation list.
1577 freelist
= page
->freelist
;
1578 counters
= page
->counters
;
1579 new.counters
= counters
;
1580 *objects
= new.objects
- new.inuse
;
1582 new.inuse
= page
->objects
;
1583 new.freelist
= NULL
;
1585 new.freelist
= freelist
;
1588 VM_BUG_ON(new.frozen
);
1591 if (!__cmpxchg_double_slab(s
, page
,
1593 new.freelist
, new.counters
,
1597 remove_partial(n
, page
);
1602 static void put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
);
1603 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
);
1606 * Try to allocate a partial slab from a specific node.
1608 static void *get_partial_node(struct kmem_cache
*s
, struct kmem_cache_node
*n
,
1609 struct kmem_cache_cpu
*c
, gfp_t flags
)
1611 struct page
*page
, *page2
;
1612 void *object
= NULL
;
1617 * Racy check. If we mistakenly see no partial slabs then we
1618 * just allocate an empty slab. If we mistakenly try to get a
1619 * partial slab and there is none available then get_partials()
1622 if (!n
|| !n
->nr_partial
)
1625 spin_lock(&n
->list_lock
);
1626 list_for_each_entry_safe(page
, page2
, &n
->partial
, lru
) {
1629 if (!pfmemalloc_match(page
, flags
))
1632 t
= acquire_slab(s
, n
, page
, object
== NULL
, &objects
);
1636 available
+= objects
;
1639 stat(s
, ALLOC_FROM_PARTIAL
);
1642 put_cpu_partial(s
, page
, 0);
1643 stat(s
, CPU_PARTIAL_NODE
);
1645 if (!kmem_cache_has_cpu_partial(s
)
1646 || available
> s
->cpu_partial
/ 2)
1650 spin_unlock(&n
->list_lock
);
1655 * Get a page from somewhere. Search in increasing NUMA distances.
1657 static void *get_any_partial(struct kmem_cache
*s
, gfp_t flags
,
1658 struct kmem_cache_cpu
*c
)
1661 struct zonelist
*zonelist
;
1664 enum zone_type high_zoneidx
= gfp_zone(flags
);
1666 unsigned int cpuset_mems_cookie
;
1669 * The defrag ratio allows a configuration of the tradeoffs between
1670 * inter node defragmentation and node local allocations. A lower
1671 * defrag_ratio increases the tendency to do local allocations
1672 * instead of attempting to obtain partial slabs from other nodes.
1674 * If the defrag_ratio is set to 0 then kmalloc() always
1675 * returns node local objects. If the ratio is higher then kmalloc()
1676 * may return off node objects because partial slabs are obtained
1677 * from other nodes and filled up.
1679 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1680 * defrag_ratio = 1000) then every (well almost) allocation will
1681 * first attempt to defrag slab caches on other nodes. This means
1682 * scanning over all nodes to look for partial slabs which may be
1683 * expensive if we do it every time we are trying to find a slab
1684 * with available objects.
1686 if (!s
->remote_node_defrag_ratio
||
1687 get_cycles() % 1024 > s
->remote_node_defrag_ratio
)
1691 cpuset_mems_cookie
= read_mems_allowed_begin();
1692 zonelist
= node_zonelist(mempolicy_slab_node(), flags
);
1693 for_each_zone_zonelist(zone
, z
, zonelist
, high_zoneidx
) {
1694 struct kmem_cache_node
*n
;
1696 n
= get_node(s
, zone_to_nid(zone
));
1698 if (n
&& cpuset_zone_allowed_hardwall(zone
, flags
) &&
1699 n
->nr_partial
> s
->min_partial
) {
1700 object
= get_partial_node(s
, n
, c
, flags
);
1703 * Don't check read_mems_allowed_retry()
1704 * here - if mems_allowed was updated in
1705 * parallel, that was a harmless race
1706 * between allocation and the cpuset
1713 } while (read_mems_allowed_retry(cpuset_mems_cookie
));
1719 * Get a partial page, lock it and return it.
1721 static void *get_partial(struct kmem_cache
*s
, gfp_t flags
, int node
,
1722 struct kmem_cache_cpu
*c
)
1725 int searchnode
= (node
== NUMA_NO_NODE
) ? numa_node_id() : node
;
1727 object
= get_partial_node(s
, get_node(s
, searchnode
), c
, flags
);
1728 if (object
|| node
!= NUMA_NO_NODE
)
1731 return get_any_partial(s
, flags
, c
);
1734 #ifdef CONFIG_PREEMPT
1736 * Calculate the next globally unique transaction for disambiguiation
1737 * during cmpxchg. The transactions start with the cpu number and are then
1738 * incremented by CONFIG_NR_CPUS.
1740 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1743 * No preemption supported therefore also no need to check for
1749 static inline unsigned long next_tid(unsigned long tid
)
1751 return tid
+ TID_STEP
;
1754 static inline unsigned int tid_to_cpu(unsigned long tid
)
1756 return tid
% TID_STEP
;
1759 static inline unsigned long tid_to_event(unsigned long tid
)
1761 return tid
/ TID_STEP
;
1764 static inline unsigned int init_tid(int cpu
)
1769 static inline void note_cmpxchg_failure(const char *n
,
1770 const struct kmem_cache
*s
, unsigned long tid
)
1772 #ifdef SLUB_DEBUG_CMPXCHG
1773 unsigned long actual_tid
= __this_cpu_read(s
->cpu_slab
->tid
);
1775 printk(KERN_INFO
"%s %s: cmpxchg redo ", n
, s
->name
);
1777 #ifdef CONFIG_PREEMPT
1778 if (tid_to_cpu(tid
) != tid_to_cpu(actual_tid
))
1779 printk("due to cpu change %d -> %d\n",
1780 tid_to_cpu(tid
), tid_to_cpu(actual_tid
));
1783 if (tid_to_event(tid
) != tid_to_event(actual_tid
))
1784 printk("due to cpu running other code. Event %ld->%ld\n",
1785 tid_to_event(tid
), tid_to_event(actual_tid
));
1787 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1788 actual_tid
, tid
, next_tid(tid
));
1790 stat(s
, CMPXCHG_DOUBLE_CPU_FAIL
);
1793 static void init_kmem_cache_cpus(struct kmem_cache
*s
)
1797 for_each_possible_cpu(cpu
)
1798 per_cpu_ptr(s
->cpu_slab
, cpu
)->tid
= init_tid(cpu
);
1802 * Remove the cpu slab
1804 static void deactivate_slab(struct kmem_cache
*s
, struct page
*page
,
1807 enum slab_modes
{ M_NONE
, M_PARTIAL
, M_FULL
, M_FREE
};
1808 struct kmem_cache_node
*n
= get_node(s
, page_to_nid(page
));
1810 enum slab_modes l
= M_NONE
, m
= M_NONE
;
1812 int tail
= DEACTIVATE_TO_HEAD
;
1816 if (page
->freelist
) {
1817 stat(s
, DEACTIVATE_REMOTE_FREES
);
1818 tail
= DEACTIVATE_TO_TAIL
;
1822 * Stage one: Free all available per cpu objects back
1823 * to the page freelist while it is still frozen. Leave the
1826 * There is no need to take the list->lock because the page
1829 while (freelist
&& (nextfree
= get_freepointer(s
, freelist
))) {
1831 unsigned long counters
;
1834 prior
= page
->freelist
;
1835 counters
= page
->counters
;
1836 set_freepointer(s
, freelist
, prior
);
1837 new.counters
= counters
;
1839 VM_BUG_ON(!new.frozen
);
1841 } while (!__cmpxchg_double_slab(s
, page
,
1843 freelist
, new.counters
,
1844 "drain percpu freelist"));
1846 freelist
= nextfree
;
1850 * Stage two: Ensure that the page is unfrozen while the
1851 * list presence reflects the actual number of objects
1854 * We setup the list membership and then perform a cmpxchg
1855 * with the count. If there is a mismatch then the page
1856 * is not unfrozen but the page is on the wrong list.
1858 * Then we restart the process which may have to remove
1859 * the page from the list that we just put it on again
1860 * because the number of objects in the slab may have
1865 old
.freelist
= page
->freelist
;
1866 old
.counters
= page
->counters
;
1867 VM_BUG_ON(!old
.frozen
);
1869 /* Determine target state of the slab */
1870 new.counters
= old
.counters
;
1873 set_freepointer(s
, freelist
, old
.freelist
);
1874 new.freelist
= freelist
;
1876 new.freelist
= old
.freelist
;
1880 if (!new.inuse
&& n
->nr_partial
> s
->min_partial
)
1882 else if (new.freelist
) {
1887 * Taking the spinlock removes the possiblity
1888 * that acquire_slab() will see a slab page that
1891 spin_lock(&n
->list_lock
);
1895 if (kmem_cache_debug(s
) && !lock
) {
1898 * This also ensures that the scanning of full
1899 * slabs from diagnostic functions will not see
1902 spin_lock(&n
->list_lock
);
1910 remove_partial(n
, page
);
1912 else if (l
== M_FULL
)
1914 remove_full(s
, n
, page
);
1916 if (m
== M_PARTIAL
) {
1918 add_partial(n
, page
, tail
);
1921 } else if (m
== M_FULL
) {
1923 stat(s
, DEACTIVATE_FULL
);
1924 add_full(s
, n
, page
);
1930 if (!__cmpxchg_double_slab(s
, page
,
1931 old
.freelist
, old
.counters
,
1932 new.freelist
, new.counters
,
1937 spin_unlock(&n
->list_lock
);
1940 stat(s
, DEACTIVATE_EMPTY
);
1941 discard_slab(s
, page
);
1947 * Unfreeze all the cpu partial slabs.
1949 * This function must be called with interrupts disabled
1950 * for the cpu using c (or some other guarantee must be there
1951 * to guarantee no concurrent accesses).
1953 static void unfreeze_partials(struct kmem_cache
*s
,
1954 struct kmem_cache_cpu
*c
)
1956 #ifdef CONFIG_SLUB_CPU_PARTIAL
1957 struct kmem_cache_node
*n
= NULL
, *n2
= NULL
;
1958 struct page
*page
, *discard_page
= NULL
;
1960 while ((page
= c
->partial
)) {
1964 c
->partial
= page
->next
;
1966 n2
= get_node(s
, page_to_nid(page
));
1969 spin_unlock(&n
->list_lock
);
1972 spin_lock(&n
->list_lock
);
1977 old
.freelist
= page
->freelist
;
1978 old
.counters
= page
->counters
;
1979 VM_BUG_ON(!old
.frozen
);
1981 new.counters
= old
.counters
;
1982 new.freelist
= old
.freelist
;
1986 } while (!__cmpxchg_double_slab(s
, page
,
1987 old
.freelist
, old
.counters
,
1988 new.freelist
, new.counters
,
1989 "unfreezing slab"));
1991 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
)) {
1992 page
->next
= discard_page
;
1993 discard_page
= page
;
1995 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
1996 stat(s
, FREE_ADD_PARTIAL
);
2001 spin_unlock(&n
->list_lock
);
2003 while (discard_page
) {
2004 page
= discard_page
;
2005 discard_page
= discard_page
->next
;
2007 stat(s
, DEACTIVATE_EMPTY
);
2008 discard_slab(s
, page
);
2015 * Put a page that was just frozen (in __slab_free) into a partial page
2016 * slot if available. This is done without interrupts disabled and without
2017 * preemption disabled. The cmpxchg is racy and may put the partial page
2018 * onto a random cpus partial slot.
2020 * If we did not find a slot then simply move all the partials to the
2021 * per node partial list.
2023 static void put_cpu_partial(struct kmem_cache
*s
, struct page
*page
, int drain
)
2025 #ifdef CONFIG_SLUB_CPU_PARTIAL
2026 struct page
*oldpage
;
2033 oldpage
= this_cpu_read(s
->cpu_slab
->partial
);
2036 pobjects
= oldpage
->pobjects
;
2037 pages
= oldpage
->pages
;
2038 if (drain
&& pobjects
> s
->cpu_partial
) {
2039 unsigned long flags
;
2041 * partial array is full. Move the existing
2042 * set to the per node partial list.
2044 local_irq_save(flags
);
2045 unfreeze_partials(s
, this_cpu_ptr(s
->cpu_slab
));
2046 local_irq_restore(flags
);
2050 stat(s
, CPU_PARTIAL_DRAIN
);
2055 pobjects
+= page
->objects
- page
->inuse
;
2057 page
->pages
= pages
;
2058 page
->pobjects
= pobjects
;
2059 page
->next
= oldpage
;
2061 } while (this_cpu_cmpxchg(s
->cpu_slab
->partial
, oldpage
, page
)
2066 static inline void flush_slab(struct kmem_cache
*s
, struct kmem_cache_cpu
*c
)
2068 stat(s
, CPUSLAB_FLUSH
);
2069 deactivate_slab(s
, c
->page
, c
->freelist
);
2071 c
->tid
= next_tid(c
->tid
);
2079 * Called from IPI handler with interrupts disabled.
2081 static inline void __flush_cpu_slab(struct kmem_cache
*s
, int cpu
)
2083 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2089 unfreeze_partials(s
, c
);
2093 static void flush_cpu_slab(void *d
)
2095 struct kmem_cache
*s
= d
;
2097 __flush_cpu_slab(s
, smp_processor_id());
2100 static bool has_cpu_slab(int cpu
, void *info
)
2102 struct kmem_cache
*s
= info
;
2103 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
, cpu
);
2105 return c
->page
|| c
->partial
;
2108 static void flush_all(struct kmem_cache
*s
)
2110 on_each_cpu_cond(has_cpu_slab
, flush_cpu_slab
, s
, 1, GFP_ATOMIC
);
2114 * Check if the objects in a per cpu structure fit numa
2115 * locality expectations.
2117 static inline int node_match(struct page
*page
, int node
)
2120 if (!page
|| (node
!= NUMA_NO_NODE
&& page_to_nid(page
) != node
))
2126 static int count_free(struct page
*page
)
2128 return page
->objects
- page
->inuse
;
2131 static unsigned long count_partial(struct kmem_cache_node
*n
,
2132 int (*get_count
)(struct page
*))
2134 unsigned long flags
;
2135 unsigned long x
= 0;
2138 spin_lock_irqsave(&n
->list_lock
, flags
);
2139 list_for_each_entry(page
, &n
->partial
, lru
)
2140 x
+= get_count(page
);
2141 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2145 static inline unsigned long node_nr_objs(struct kmem_cache_node
*n
)
2147 #ifdef CONFIG_SLUB_DEBUG
2148 return atomic_long_read(&n
->total_objects
);
2154 static noinline
void
2155 slab_out_of_memory(struct kmem_cache
*s
, gfp_t gfpflags
, int nid
)
2160 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
2162 printk(KERN_WARNING
" cache: %s, object size: %d, buffer size: %d, "
2163 "default order: %d, min order: %d\n", s
->name
, s
->object_size
,
2164 s
->size
, oo_order(s
->oo
), oo_order(s
->min
));
2166 if (oo_order(s
->min
) > get_order(s
->object_size
))
2167 printk(KERN_WARNING
" %s debugging increased min order, use "
2168 "slub_debug=O to disable.\n", s
->name
);
2170 for_each_online_node(node
) {
2171 struct kmem_cache_node
*n
= get_node(s
, node
);
2172 unsigned long nr_slabs
;
2173 unsigned long nr_objs
;
2174 unsigned long nr_free
;
2179 nr_free
= count_partial(n
, count_free
);
2180 nr_slabs
= node_nr_slabs(n
);
2181 nr_objs
= node_nr_objs(n
);
2184 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
2185 node
, nr_slabs
, nr_objs
, nr_free
);
2189 static inline void *new_slab_objects(struct kmem_cache
*s
, gfp_t flags
,
2190 int node
, struct kmem_cache_cpu
**pc
)
2193 struct kmem_cache_cpu
*c
= *pc
;
2196 freelist
= get_partial(s
, flags
, node
, c
);
2201 page
= new_slab(s
, flags
, node
);
2203 c
= __this_cpu_ptr(s
->cpu_slab
);
2208 * No other reference to the page yet so we can
2209 * muck around with it freely without cmpxchg
2211 freelist
= page
->freelist
;
2212 page
->freelist
= NULL
;
2214 stat(s
, ALLOC_SLAB
);
2223 static inline bool pfmemalloc_match(struct page
*page
, gfp_t gfpflags
)
2225 if (unlikely(PageSlabPfmemalloc(page
)))
2226 return gfp_pfmemalloc_allowed(gfpflags
);
2232 * Check the page->freelist of a page and either transfer the freelist to the
2233 * per cpu freelist or deactivate the page.
2235 * The page is still frozen if the return value is not NULL.
2237 * If this function returns NULL then the page has been unfrozen.
2239 * This function must be called with interrupt disabled.
2241 static inline void *get_freelist(struct kmem_cache
*s
, struct page
*page
)
2244 unsigned long counters
;
2248 freelist
= page
->freelist
;
2249 counters
= page
->counters
;
2251 new.counters
= counters
;
2252 VM_BUG_ON(!new.frozen
);
2254 new.inuse
= page
->objects
;
2255 new.frozen
= freelist
!= NULL
;
2257 } while (!__cmpxchg_double_slab(s
, page
,
2266 * Slow path. The lockless freelist is empty or we need to perform
2269 * Processing is still very fast if new objects have been freed to the
2270 * regular freelist. In that case we simply take over the regular freelist
2271 * as the lockless freelist and zap the regular freelist.
2273 * If that is not working then we fall back to the partial lists. We take the
2274 * first element of the freelist as the object to allocate now and move the
2275 * rest of the freelist to the lockless freelist.
2277 * And if we were unable to get a new slab from the partial slab lists then
2278 * we need to allocate a new slab. This is the slowest path since it involves
2279 * a call to the page allocator and the setup of a new slab.
2281 static void *__slab_alloc(struct kmem_cache
*s
, gfp_t gfpflags
, int node
,
2282 unsigned long addr
, struct kmem_cache_cpu
*c
)
2286 unsigned long flags
;
2288 local_irq_save(flags
);
2289 #ifdef CONFIG_PREEMPT
2291 * We may have been preempted and rescheduled on a different
2292 * cpu before disabling interrupts. Need to reload cpu area
2295 c
= this_cpu_ptr(s
->cpu_slab
);
2303 if (unlikely(!node_match(page
, node
))) {
2304 stat(s
, ALLOC_NODE_MISMATCH
);
2305 deactivate_slab(s
, page
, c
->freelist
);
2312 * By rights, we should be searching for a slab page that was
2313 * PFMEMALLOC but right now, we are losing the pfmemalloc
2314 * information when the page leaves the per-cpu allocator
2316 if (unlikely(!pfmemalloc_match(page
, gfpflags
))) {
2317 deactivate_slab(s
, page
, c
->freelist
);
2323 /* must check again c->freelist in case of cpu migration or IRQ */
2324 freelist
= c
->freelist
;
2328 stat(s
, ALLOC_SLOWPATH
);
2330 freelist
= get_freelist(s
, page
);
2334 stat(s
, DEACTIVATE_BYPASS
);
2338 stat(s
, ALLOC_REFILL
);
2342 * freelist is pointing to the list of objects to be used.
2343 * page is pointing to the page from which the objects are obtained.
2344 * That page must be frozen for per cpu allocations to work.
2346 VM_BUG_ON(!c
->page
->frozen
);
2347 c
->freelist
= get_freepointer(s
, freelist
);
2348 c
->tid
= next_tid(c
->tid
);
2349 local_irq_restore(flags
);
2355 page
= c
->page
= c
->partial
;
2356 c
->partial
= page
->next
;
2357 stat(s
, CPU_PARTIAL_ALLOC
);
2362 freelist
= new_slab_objects(s
, gfpflags
, node
, &c
);
2364 if (unlikely(!freelist
)) {
2365 if (!(gfpflags
& __GFP_NOWARN
) && printk_ratelimit())
2366 slab_out_of_memory(s
, gfpflags
, node
);
2368 local_irq_restore(flags
);
2373 if (likely(!kmem_cache_debug(s
) && pfmemalloc_match(page
, gfpflags
)))
2376 /* Only entered in the debug case */
2377 if (kmem_cache_debug(s
) &&
2378 !alloc_debug_processing(s
, page
, freelist
, addr
))
2379 goto new_slab
; /* Slab failed checks. Next slab needed */
2381 deactivate_slab(s
, page
, get_freepointer(s
, freelist
));
2384 local_irq_restore(flags
);
2389 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
2390 * have the fastpath folded into their functions. So no function call
2391 * overhead for requests that can be satisfied on the fastpath.
2393 * The fastpath works by first checking if the lockless freelist can be used.
2394 * If not then __slab_alloc is called for slow processing.
2396 * Otherwise we can simply pick the next object from the lockless free list.
2398 static __always_inline
void *slab_alloc_node(struct kmem_cache
*s
,
2399 gfp_t gfpflags
, int node
, unsigned long addr
)
2402 struct kmem_cache_cpu
*c
;
2406 if (slab_pre_alloc_hook(s
, gfpflags
))
2409 s
= memcg_kmem_get_cache(s
, gfpflags
);
2412 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
2413 * enabled. We may switch back and forth between cpus while
2414 * reading from one cpu area. That does not matter as long
2415 * as we end up on the original cpu again when doing the cmpxchg.
2417 * Preemption is disabled for the retrieval of the tid because that
2418 * must occur from the current processor. We cannot allow rescheduling
2419 * on a different processor between the determination of the pointer
2420 * and the retrieval of the tid.
2423 c
= __this_cpu_ptr(s
->cpu_slab
);
2426 * The transaction ids are globally unique per cpu and per operation on
2427 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
2428 * occurs on the right processor and that there was no operation on the
2429 * linked list in between.
2434 object
= c
->freelist
;
2436 if (unlikely(!object
|| !node_match(page
, node
)))
2437 object
= __slab_alloc(s
, gfpflags
, node
, addr
, c
);
2440 void *next_object
= get_freepointer_safe(s
, object
);
2443 * The cmpxchg will only match if there was no additional
2444 * operation and if we are on the right processor.
2446 * The cmpxchg does the following atomically (without lock
2448 * 1. Relocate first pointer to the current per cpu area.
2449 * 2. Verify that tid and freelist have not been changed
2450 * 3. If they were not changed replace tid and freelist
2452 * Since this is without lock semantics the protection is only
2453 * against code executing on this cpu *not* from access by
2456 if (unlikely(!this_cpu_cmpxchg_double(
2457 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2459 next_object
, next_tid(tid
)))) {
2461 note_cmpxchg_failure("slab_alloc", s
, tid
);
2464 prefetch_freepointer(s
, next_object
);
2465 stat(s
, ALLOC_FASTPATH
);
2468 if (unlikely(gfpflags
& __GFP_ZERO
) && object
)
2469 memset(object
, 0, s
->object_size
);
2471 slab_post_alloc_hook(s
, gfpflags
, object
);
2476 static __always_inline
void *slab_alloc(struct kmem_cache
*s
,
2477 gfp_t gfpflags
, unsigned long addr
)
2479 return slab_alloc_node(s
, gfpflags
, NUMA_NO_NODE
, addr
);
2482 void *kmem_cache_alloc(struct kmem_cache
*s
, gfp_t gfpflags
)
2484 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2486 trace_kmem_cache_alloc(_RET_IP_
, ret
, s
->object_size
,
2491 EXPORT_SYMBOL(kmem_cache_alloc
);
2493 #ifdef CONFIG_TRACING
2494 void *kmem_cache_alloc_trace(struct kmem_cache
*s
, gfp_t gfpflags
, size_t size
)
2496 void *ret
= slab_alloc(s
, gfpflags
, _RET_IP_
);
2497 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, gfpflags
);
2500 EXPORT_SYMBOL(kmem_cache_alloc_trace
);
2504 void *kmem_cache_alloc_node(struct kmem_cache
*s
, gfp_t gfpflags
, int node
)
2506 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2508 trace_kmem_cache_alloc_node(_RET_IP_
, ret
,
2509 s
->object_size
, s
->size
, gfpflags
, node
);
2513 EXPORT_SYMBOL(kmem_cache_alloc_node
);
2515 #ifdef CONFIG_TRACING
2516 void *kmem_cache_alloc_node_trace(struct kmem_cache
*s
,
2518 int node
, size_t size
)
2520 void *ret
= slab_alloc_node(s
, gfpflags
, node
, _RET_IP_
);
2522 trace_kmalloc_node(_RET_IP_
, ret
,
2523 size
, s
->size
, gfpflags
, node
);
2526 EXPORT_SYMBOL(kmem_cache_alloc_node_trace
);
2531 * Slow patch handling. This may still be called frequently since objects
2532 * have a longer lifetime than the cpu slabs in most processing loads.
2534 * So we still attempt to reduce cache line usage. Just take the slab
2535 * lock and free the item. If there is no additional partial page
2536 * handling required then we can return immediately.
2538 static void __slab_free(struct kmem_cache
*s
, struct page
*page
,
2539 void *x
, unsigned long addr
)
2542 void **object
= (void *)x
;
2545 unsigned long counters
;
2546 struct kmem_cache_node
*n
= NULL
;
2547 unsigned long uninitialized_var(flags
);
2549 stat(s
, FREE_SLOWPATH
);
2551 if (kmem_cache_debug(s
) &&
2552 !(n
= free_debug_processing(s
, page
, x
, addr
, &flags
)))
2557 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2560 prior
= page
->freelist
;
2561 counters
= page
->counters
;
2562 set_freepointer(s
, object
, prior
);
2563 new.counters
= counters
;
2564 was_frozen
= new.frozen
;
2566 if ((!new.inuse
|| !prior
) && !was_frozen
) {
2568 if (kmem_cache_has_cpu_partial(s
) && !prior
) {
2571 * Slab was on no list before and will be
2573 * We can defer the list move and instead
2578 } else { /* Needs to be taken off a list */
2580 n
= get_node(s
, page_to_nid(page
));
2582 * Speculatively acquire the list_lock.
2583 * If the cmpxchg does not succeed then we may
2584 * drop the list_lock without any processing.
2586 * Otherwise the list_lock will synchronize with
2587 * other processors updating the list of slabs.
2589 spin_lock_irqsave(&n
->list_lock
, flags
);
2594 } while (!cmpxchg_double_slab(s
, page
,
2596 object
, new.counters
,
2602 * If we just froze the page then put it onto the
2603 * per cpu partial list.
2605 if (new.frozen
&& !was_frozen
) {
2606 put_cpu_partial(s
, page
, 1);
2607 stat(s
, CPU_PARTIAL_FREE
);
2610 * The list lock was not taken therefore no list
2611 * activity can be necessary.
2614 stat(s
, FREE_FROZEN
);
2618 if (unlikely(!new.inuse
&& n
->nr_partial
> s
->min_partial
))
2622 * Objects left in the slab. If it was not on the partial list before
2625 if (!kmem_cache_has_cpu_partial(s
) && unlikely(!prior
)) {
2626 if (kmem_cache_debug(s
))
2627 remove_full(s
, n
, page
);
2628 add_partial(n
, page
, DEACTIVATE_TO_TAIL
);
2629 stat(s
, FREE_ADD_PARTIAL
);
2631 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2637 * Slab on the partial list.
2639 remove_partial(n
, page
);
2640 stat(s
, FREE_REMOVE_PARTIAL
);
2642 /* Slab must be on the full list */
2643 remove_full(s
, n
, page
);
2646 spin_unlock_irqrestore(&n
->list_lock
, flags
);
2648 discard_slab(s
, page
);
2652 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2653 * can perform fastpath freeing without additional function calls.
2655 * The fastpath is only possible if we are freeing to the current cpu slab
2656 * of this processor. This typically the case if we have just allocated
2659 * If fastpath is not possible then fall back to __slab_free where we deal
2660 * with all sorts of special processing.
2662 static __always_inline
void slab_free(struct kmem_cache
*s
,
2663 struct page
*page
, void *x
, unsigned long addr
)
2665 void **object
= (void *)x
;
2666 struct kmem_cache_cpu
*c
;
2669 slab_free_hook(s
, x
);
2673 * Determine the currently cpus per cpu slab.
2674 * The cpu may change afterward. However that does not matter since
2675 * data is retrieved via this pointer. If we are on the same cpu
2676 * during the cmpxchg then the free will succedd.
2679 c
= __this_cpu_ptr(s
->cpu_slab
);
2684 if (likely(page
== c
->page
)) {
2685 set_freepointer(s
, object
, c
->freelist
);
2687 if (unlikely(!this_cpu_cmpxchg_double(
2688 s
->cpu_slab
->freelist
, s
->cpu_slab
->tid
,
2690 object
, next_tid(tid
)))) {
2692 note_cmpxchg_failure("slab_free", s
, tid
);
2695 stat(s
, FREE_FASTPATH
);
2697 __slab_free(s
, page
, x
, addr
);
2701 void kmem_cache_free(struct kmem_cache
*s
, void *x
)
2703 s
= cache_from_obj(s
, x
);
2706 slab_free(s
, virt_to_head_page(x
), x
, _RET_IP_
);
2707 trace_kmem_cache_free(_RET_IP_
, x
);
2709 EXPORT_SYMBOL(kmem_cache_free
);
2712 * Object placement in a slab is made very easy because we always start at
2713 * offset 0. If we tune the size of the object to the alignment then we can
2714 * get the required alignment by putting one properly sized object after
2717 * Notice that the allocation order determines the sizes of the per cpu
2718 * caches. Each processor has always one slab available for allocations.
2719 * Increasing the allocation order reduces the number of times that slabs
2720 * must be moved on and off the partial lists and is therefore a factor in
2725 * Mininum / Maximum order of slab pages. This influences locking overhead
2726 * and slab fragmentation. A higher order reduces the number of partial slabs
2727 * and increases the number of allocations possible without having to
2728 * take the list_lock.
2730 static int slub_min_order
;
2731 static int slub_max_order
= PAGE_ALLOC_COSTLY_ORDER
;
2732 static int slub_min_objects
;
2735 * Merge control. If this is set then no merging of slab caches will occur.
2736 * (Could be removed. This was introduced to pacify the merge skeptics.)
2738 static int slub_nomerge
;
2741 * Calculate the order of allocation given an slab object size.
2743 * The order of allocation has significant impact on performance and other
2744 * system components. Generally order 0 allocations should be preferred since
2745 * order 0 does not cause fragmentation in the page allocator. Larger objects
2746 * be problematic to put into order 0 slabs because there may be too much
2747 * unused space left. We go to a higher order if more than 1/16th of the slab
2750 * In order to reach satisfactory performance we must ensure that a minimum
2751 * number of objects is in one slab. Otherwise we may generate too much
2752 * activity on the partial lists which requires taking the list_lock. This is
2753 * less a concern for large slabs though which are rarely used.
2755 * slub_max_order specifies the order where we begin to stop considering the
2756 * number of objects in a slab as critical. If we reach slub_max_order then
2757 * we try to keep the page order as low as possible. So we accept more waste
2758 * of space in favor of a small page order.
2760 * Higher order allocations also allow the placement of more objects in a
2761 * slab and thereby reduce object handling overhead. If the user has
2762 * requested a higher mininum order then we start with that one instead of
2763 * the smallest order which will fit the object.
2765 static inline int slab_order(int size
, int min_objects
,
2766 int max_order
, int fract_leftover
, int reserved
)
2770 int min_order
= slub_min_order
;
2772 if (order_objects(min_order
, size
, reserved
) > MAX_OBJS_PER_PAGE
)
2773 return get_order(size
* MAX_OBJS_PER_PAGE
) - 1;
2775 for (order
= max(min_order
,
2776 fls(min_objects
* size
- 1) - PAGE_SHIFT
);
2777 order
<= max_order
; order
++) {
2779 unsigned long slab_size
= PAGE_SIZE
<< order
;
2781 if (slab_size
< min_objects
* size
+ reserved
)
2784 rem
= (slab_size
- reserved
) % size
;
2786 if (rem
<= slab_size
/ fract_leftover
)
2794 static inline int calculate_order(int size
, int reserved
)
2802 * Attempt to find best configuration for a slab. This
2803 * works by first attempting to generate a layout with
2804 * the best configuration and backing off gradually.
2806 * First we reduce the acceptable waste in a slab. Then
2807 * we reduce the minimum objects required in a slab.
2809 min_objects
= slub_min_objects
;
2811 min_objects
= 4 * (fls(nr_cpu_ids
) + 1);
2812 max_objects
= order_objects(slub_max_order
, size
, reserved
);
2813 min_objects
= min(min_objects
, max_objects
);
2815 while (min_objects
> 1) {
2817 while (fraction
>= 4) {
2818 order
= slab_order(size
, min_objects
,
2819 slub_max_order
, fraction
, reserved
);
2820 if (order
<= slub_max_order
)
2828 * We were unable to place multiple objects in a slab. Now
2829 * lets see if we can place a single object there.
2831 order
= slab_order(size
, 1, slub_max_order
, 1, reserved
);
2832 if (order
<= slub_max_order
)
2836 * Doh this slab cannot be placed using slub_max_order.
2838 order
= slab_order(size
, 1, MAX_ORDER
, 1, reserved
);
2839 if (order
< MAX_ORDER
)
2845 init_kmem_cache_node(struct kmem_cache_node
*n
)
2848 spin_lock_init(&n
->list_lock
);
2849 INIT_LIST_HEAD(&n
->partial
);
2850 #ifdef CONFIG_SLUB_DEBUG
2851 atomic_long_set(&n
->nr_slabs
, 0);
2852 atomic_long_set(&n
->total_objects
, 0);
2853 INIT_LIST_HEAD(&n
->full
);
2857 static inline int alloc_kmem_cache_cpus(struct kmem_cache
*s
)
2859 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE
<
2860 KMALLOC_SHIFT_HIGH
* sizeof(struct kmem_cache_cpu
));
2863 * Must align to double word boundary for the double cmpxchg
2864 * instructions to work; see __pcpu_double_call_return_bool().
2866 s
->cpu_slab
= __alloc_percpu(sizeof(struct kmem_cache_cpu
),
2867 2 * sizeof(void *));
2872 init_kmem_cache_cpus(s
);
2877 static struct kmem_cache
*kmem_cache_node
;
2880 * No kmalloc_node yet so do it by hand. We know that this is the first
2881 * slab on the node for this slabcache. There are no concurrent accesses
2884 * Note that this function only works on the kmem_cache_node
2885 * when allocating for the kmem_cache_node. This is used for bootstrapping
2886 * memory on a fresh node that has no slab structures yet.
2888 static void early_kmem_cache_node_alloc(int node
)
2891 struct kmem_cache_node
*n
;
2893 BUG_ON(kmem_cache_node
->size
< sizeof(struct kmem_cache_node
));
2895 page
= new_slab(kmem_cache_node
, GFP_NOWAIT
, node
);
2898 if (page_to_nid(page
) != node
) {
2899 printk(KERN_ERR
"SLUB: Unable to allocate memory from "
2901 printk(KERN_ERR
"SLUB: Allocating a useless per node structure "
2902 "in order to be able to continue\n");
2907 page
->freelist
= get_freepointer(kmem_cache_node
, n
);
2910 kmem_cache_node
->node
[node
] = n
;
2911 #ifdef CONFIG_SLUB_DEBUG
2912 init_object(kmem_cache_node
, n
, SLUB_RED_ACTIVE
);
2913 init_tracking(kmem_cache_node
, n
);
2915 init_kmem_cache_node(n
);
2916 inc_slabs_node(kmem_cache_node
, node
, page
->objects
);
2919 * No locks need to be taken here as it has just been
2920 * initialized and there is no concurrent access.
2922 __add_partial(n
, page
, DEACTIVATE_TO_HEAD
);
2925 static void free_kmem_cache_nodes(struct kmem_cache
*s
)
2929 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2930 struct kmem_cache_node
*n
= s
->node
[node
];
2933 kmem_cache_free(kmem_cache_node
, n
);
2935 s
->node
[node
] = NULL
;
2939 static int init_kmem_cache_nodes(struct kmem_cache
*s
)
2943 for_each_node_state(node
, N_NORMAL_MEMORY
) {
2944 struct kmem_cache_node
*n
;
2946 if (slab_state
== DOWN
) {
2947 early_kmem_cache_node_alloc(node
);
2950 n
= kmem_cache_alloc_node(kmem_cache_node
,
2954 free_kmem_cache_nodes(s
);
2959 init_kmem_cache_node(n
);
2964 static void set_min_partial(struct kmem_cache
*s
, unsigned long min
)
2966 if (min
< MIN_PARTIAL
)
2968 else if (min
> MAX_PARTIAL
)
2970 s
->min_partial
= min
;
2974 * calculate_sizes() determines the order and the distribution of data within
2977 static int calculate_sizes(struct kmem_cache
*s
, int forced_order
)
2979 unsigned long flags
= s
->flags
;
2980 unsigned long size
= s
->object_size
;
2984 * Round up object size to the next word boundary. We can only
2985 * place the free pointer at word boundaries and this determines
2986 * the possible location of the free pointer.
2988 size
= ALIGN(size
, sizeof(void *));
2990 #ifdef CONFIG_SLUB_DEBUG
2992 * Determine if we can poison the object itself. If the user of
2993 * the slab may touch the object after free or before allocation
2994 * then we should never poison the object itself.
2996 if ((flags
& SLAB_POISON
) && !(flags
& SLAB_DESTROY_BY_RCU
) &&
2998 s
->flags
|= __OBJECT_POISON
;
3000 s
->flags
&= ~__OBJECT_POISON
;
3004 * If we are Redzoning then check if there is some space between the
3005 * end of the object and the free pointer. If not then add an
3006 * additional word to have some bytes to store Redzone information.
3008 if ((flags
& SLAB_RED_ZONE
) && size
== s
->object_size
)
3009 size
+= sizeof(void *);
3013 * With that we have determined the number of bytes in actual use
3014 * by the object. This is the potential offset to the free pointer.
3018 if (((flags
& (SLAB_DESTROY_BY_RCU
| SLAB_POISON
)) ||
3021 * Relocate free pointer after the object if it is not
3022 * permitted to overwrite the first word of the object on
3025 * This is the case if we do RCU, have a constructor or
3026 * destructor or are poisoning the objects.
3029 size
+= sizeof(void *);
3032 #ifdef CONFIG_SLUB_DEBUG
3033 if (flags
& SLAB_STORE_USER
)
3035 * Need to store information about allocs and frees after
3038 size
+= 2 * sizeof(struct track
);
3040 if (flags
& SLAB_RED_ZONE
)
3042 * Add some empty padding so that we can catch
3043 * overwrites from earlier objects rather than let
3044 * tracking information or the free pointer be
3045 * corrupted if a user writes before the start
3048 size
+= sizeof(void *);
3052 * SLUB stores one object immediately after another beginning from
3053 * offset 0. In order to align the objects we have to simply size
3054 * each object to conform to the alignment.
3056 size
= ALIGN(size
, s
->align
);
3058 if (forced_order
>= 0)
3059 order
= forced_order
;
3061 order
= calculate_order(size
, s
->reserved
);
3068 s
->allocflags
|= __GFP_COMP
;
3070 if (s
->flags
& SLAB_CACHE_DMA
)
3071 s
->allocflags
|= GFP_DMA
;
3073 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
3074 s
->allocflags
|= __GFP_RECLAIMABLE
;
3077 * Determine the number of objects per slab
3079 s
->oo
= oo_make(order
, size
, s
->reserved
);
3080 s
->min
= oo_make(get_order(size
), size
, s
->reserved
);
3081 if (oo_objects(s
->oo
) > oo_objects(s
->max
))
3084 return !!oo_objects(s
->oo
);
3087 static int kmem_cache_open(struct kmem_cache
*s
, unsigned long flags
)
3089 s
->flags
= kmem_cache_flags(s
->size
, flags
, s
->name
, s
->ctor
);
3092 if (need_reserve_slab_rcu
&& (s
->flags
& SLAB_DESTROY_BY_RCU
))
3093 s
->reserved
= sizeof(struct rcu_head
);
3095 if (!calculate_sizes(s
, -1))
3097 if (disable_higher_order_debug
) {
3099 * Disable debugging flags that store metadata if the min slab
3102 if (get_order(s
->size
) > get_order(s
->object_size
)) {
3103 s
->flags
&= ~DEBUG_METADATA_FLAGS
;
3105 if (!calculate_sizes(s
, -1))
3110 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
3111 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
3112 if (system_has_cmpxchg_double() && (s
->flags
& SLAB_DEBUG_FLAGS
) == 0)
3113 /* Enable fast mode */
3114 s
->flags
|= __CMPXCHG_DOUBLE
;
3118 * The larger the object size is, the more pages we want on the partial
3119 * list to avoid pounding the page allocator excessively.
3121 set_min_partial(s
, ilog2(s
->size
) / 2);
3124 * cpu_partial determined the maximum number of objects kept in the
3125 * per cpu partial lists of a processor.
3127 * Per cpu partial lists mainly contain slabs that just have one
3128 * object freed. If they are used for allocation then they can be
3129 * filled up again with minimal effort. The slab will never hit the
3130 * per node partial lists and therefore no locking will be required.
3132 * This setting also determines
3134 * A) The number of objects from per cpu partial slabs dumped to the
3135 * per node list when we reach the limit.
3136 * B) The number of objects in cpu partial slabs to extract from the
3137 * per node list when we run out of per cpu objects. We only fetch
3138 * 50% to keep some capacity around for frees.
3140 if (!kmem_cache_has_cpu_partial(s
))
3142 else if (s
->size
>= PAGE_SIZE
)
3144 else if (s
->size
>= 1024)
3146 else if (s
->size
>= 256)
3147 s
->cpu_partial
= 13;
3149 s
->cpu_partial
= 30;
3152 s
->remote_node_defrag_ratio
= 1000;
3154 if (!init_kmem_cache_nodes(s
))
3157 if (alloc_kmem_cache_cpus(s
))
3160 free_kmem_cache_nodes(s
);
3162 if (flags
& SLAB_PANIC
)
3163 panic("Cannot create slab %s size=%lu realsize=%u "
3164 "order=%u offset=%u flags=%lx\n",
3165 s
->name
, (unsigned long)s
->size
, s
->size
,
3166 oo_order(s
->oo
), s
->offset
, flags
);
3170 static void list_slab_objects(struct kmem_cache
*s
, struct page
*page
,
3173 #ifdef CONFIG_SLUB_DEBUG
3174 void *addr
= page_address(page
);
3176 unsigned long *map
= kzalloc(BITS_TO_LONGS(page
->objects
) *
3177 sizeof(long), GFP_ATOMIC
);
3180 slab_err(s
, page
, text
, s
->name
);
3183 get_map(s
, page
, map
);
3184 for_each_object(p
, s
, addr
, page
->objects
) {
3186 if (!test_bit(slab_index(p
, s
, addr
), map
)) {
3187 printk(KERN_ERR
"INFO: Object 0x%p @offset=%tu\n",
3189 print_tracking(s
, p
);
3198 * Attempt to free all partial slabs on a node.
3199 * This is called from kmem_cache_close(). We must be the last thread
3200 * using the cache and therefore we do not need to lock anymore.
3202 static void free_partial(struct kmem_cache
*s
, struct kmem_cache_node
*n
)
3204 struct page
*page
, *h
;
3206 list_for_each_entry_safe(page
, h
, &n
->partial
, lru
) {
3208 __remove_partial(n
, page
);
3209 discard_slab(s
, page
);
3211 list_slab_objects(s
, page
,
3212 "Objects remaining in %s on kmem_cache_close()");
3218 * Release all resources used by a slab cache.
3220 static inline int kmem_cache_close(struct kmem_cache
*s
)
3225 /* Attempt to free all objects */
3226 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3227 struct kmem_cache_node
*n
= get_node(s
, node
);
3230 if (n
->nr_partial
|| slabs_node(s
, node
))
3233 free_percpu(s
->cpu_slab
);
3234 free_kmem_cache_nodes(s
);
3238 int __kmem_cache_shutdown(struct kmem_cache
*s
)
3240 int rc
= kmem_cache_close(s
);
3244 * Since slab_attr_store may take the slab_mutex, we should
3245 * release the lock while removing the sysfs entry in order to
3246 * avoid a deadlock. Because this is pretty much the last
3247 * operation we do and the lock will be released shortly after
3248 * that in slab_common.c, we could just move sysfs_slab_remove
3249 * to a later point in common code. We should do that when we
3250 * have a common sysfs framework for all allocators.
3252 mutex_unlock(&slab_mutex
);
3253 sysfs_slab_remove(s
);
3254 mutex_lock(&slab_mutex
);
3260 /********************************************************************
3262 *******************************************************************/
3264 static int __init
setup_slub_min_order(char *str
)
3266 get_option(&str
, &slub_min_order
);
3271 __setup("slub_min_order=", setup_slub_min_order
);
3273 static int __init
setup_slub_max_order(char *str
)
3275 get_option(&str
, &slub_max_order
);
3276 slub_max_order
= min(slub_max_order
, MAX_ORDER
- 1);
3281 __setup("slub_max_order=", setup_slub_max_order
);
3283 static int __init
setup_slub_min_objects(char *str
)
3285 get_option(&str
, &slub_min_objects
);
3290 __setup("slub_min_objects=", setup_slub_min_objects
);
3292 static int __init
setup_slub_nomerge(char *str
)
3298 __setup("slub_nomerge", setup_slub_nomerge
);
3300 void *__kmalloc(size_t size
, gfp_t flags
)
3302 struct kmem_cache
*s
;
3305 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
))
3306 return kmalloc_large(size
, flags
);
3308 s
= kmalloc_slab(size
, flags
);
3310 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3313 ret
= slab_alloc(s
, flags
, _RET_IP_
);
3315 trace_kmalloc(_RET_IP_
, ret
, size
, s
->size
, flags
);
3319 EXPORT_SYMBOL(__kmalloc
);
3322 static void *kmalloc_large_node(size_t size
, gfp_t flags
, int node
)
3327 flags
|= __GFP_COMP
| __GFP_NOTRACK
| __GFP_KMEMCG
;
3328 page
= alloc_pages_node(node
, flags
, get_order(size
));
3330 ptr
= page_address(page
);
3332 kmalloc_large_node_hook(ptr
, size
, flags
);
3336 void *__kmalloc_node(size_t size
, gfp_t flags
, int node
)
3338 struct kmem_cache
*s
;
3341 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
)) {
3342 ret
= kmalloc_large_node(size
, flags
, node
);
3344 trace_kmalloc_node(_RET_IP_
, ret
,
3345 size
, PAGE_SIZE
<< get_order(size
),
3351 s
= kmalloc_slab(size
, flags
);
3353 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3356 ret
= slab_alloc_node(s
, flags
, node
, _RET_IP_
);
3358 trace_kmalloc_node(_RET_IP_
, ret
, size
, s
->size
, flags
, node
);
3362 EXPORT_SYMBOL(__kmalloc_node
);
3365 size_t ksize(const void *object
)
3369 if (unlikely(object
== ZERO_SIZE_PTR
))
3372 page
= virt_to_head_page(object
);
3374 if (unlikely(!PageSlab(page
))) {
3375 WARN_ON(!PageCompound(page
));
3376 return PAGE_SIZE
<< compound_order(page
);
3379 return slab_ksize(page
->slab_cache
);
3381 EXPORT_SYMBOL(ksize
);
3383 void kfree(const void *x
)
3386 void *object
= (void *)x
;
3388 trace_kfree(_RET_IP_
, x
);
3390 if (unlikely(ZERO_OR_NULL_PTR(x
)))
3393 page
= virt_to_head_page(x
);
3394 if (unlikely(!PageSlab(page
))) {
3395 BUG_ON(!PageCompound(page
));
3397 __free_memcg_kmem_pages(page
, compound_order(page
));
3400 slab_free(page
->slab_cache
, page
, object
, _RET_IP_
);
3402 EXPORT_SYMBOL(kfree
);
3405 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
3406 * the remaining slabs by the number of items in use. The slabs with the
3407 * most items in use come first. New allocations will then fill those up
3408 * and thus they can be removed from the partial lists.
3410 * The slabs with the least items are placed last. This results in them
3411 * being allocated from last increasing the chance that the last objects
3412 * are freed in them.
3414 int kmem_cache_shrink(struct kmem_cache
*s
)
3418 struct kmem_cache_node
*n
;
3421 int objects
= oo_objects(s
->max
);
3422 struct list_head
*slabs_by_inuse
=
3423 kmalloc(sizeof(struct list_head
) * objects
, GFP_KERNEL
);
3424 unsigned long flags
;
3426 if (!slabs_by_inuse
)
3430 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3431 n
= get_node(s
, node
);
3436 for (i
= 0; i
< objects
; i
++)
3437 INIT_LIST_HEAD(slabs_by_inuse
+ i
);
3439 spin_lock_irqsave(&n
->list_lock
, flags
);
3442 * Build lists indexed by the items in use in each slab.
3444 * Note that concurrent frees may occur while we hold the
3445 * list_lock. page->inuse here is the upper limit.
3447 list_for_each_entry_safe(page
, t
, &n
->partial
, lru
) {
3448 list_move(&page
->lru
, slabs_by_inuse
+ page
->inuse
);
3454 * Rebuild the partial list with the slabs filled up most
3455 * first and the least used slabs at the end.
3457 for (i
= objects
- 1; i
> 0; i
--)
3458 list_splice(slabs_by_inuse
+ i
, n
->partial
.prev
);
3460 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3462 /* Release empty slabs */
3463 list_for_each_entry_safe(page
, t
, slabs_by_inuse
, lru
)
3464 discard_slab(s
, page
);
3467 kfree(slabs_by_inuse
);
3470 EXPORT_SYMBOL(kmem_cache_shrink
);
3472 static int slab_mem_going_offline_callback(void *arg
)
3474 struct kmem_cache
*s
;
3476 mutex_lock(&slab_mutex
);
3477 list_for_each_entry(s
, &slab_caches
, list
)
3478 kmem_cache_shrink(s
);
3479 mutex_unlock(&slab_mutex
);
3484 static void slab_mem_offline_callback(void *arg
)
3486 struct kmem_cache_node
*n
;
3487 struct kmem_cache
*s
;
3488 struct memory_notify
*marg
= arg
;
3491 offline_node
= marg
->status_change_nid_normal
;
3494 * If the node still has available memory. we need kmem_cache_node
3497 if (offline_node
< 0)
3500 mutex_lock(&slab_mutex
);
3501 list_for_each_entry(s
, &slab_caches
, list
) {
3502 n
= get_node(s
, offline_node
);
3505 * if n->nr_slabs > 0, slabs still exist on the node
3506 * that is going down. We were unable to free them,
3507 * and offline_pages() function shouldn't call this
3508 * callback. So, we must fail.
3510 BUG_ON(slabs_node(s
, offline_node
));
3512 s
->node
[offline_node
] = NULL
;
3513 kmem_cache_free(kmem_cache_node
, n
);
3516 mutex_unlock(&slab_mutex
);
3519 static int slab_mem_going_online_callback(void *arg
)
3521 struct kmem_cache_node
*n
;
3522 struct kmem_cache
*s
;
3523 struct memory_notify
*marg
= arg
;
3524 int nid
= marg
->status_change_nid_normal
;
3528 * If the node's memory is already available, then kmem_cache_node is
3529 * already created. Nothing to do.
3535 * We are bringing a node online. No memory is available yet. We must
3536 * allocate a kmem_cache_node structure in order to bring the node
3539 mutex_lock(&slab_mutex
);
3540 list_for_each_entry(s
, &slab_caches
, list
) {
3542 * XXX: kmem_cache_alloc_node will fallback to other nodes
3543 * since memory is not yet available from the node that
3546 n
= kmem_cache_alloc(kmem_cache_node
, GFP_KERNEL
);
3551 init_kmem_cache_node(n
);
3555 mutex_unlock(&slab_mutex
);
3559 static int slab_memory_callback(struct notifier_block
*self
,
3560 unsigned long action
, void *arg
)
3565 case MEM_GOING_ONLINE
:
3566 ret
= slab_mem_going_online_callback(arg
);
3568 case MEM_GOING_OFFLINE
:
3569 ret
= slab_mem_going_offline_callback(arg
);
3572 case MEM_CANCEL_ONLINE
:
3573 slab_mem_offline_callback(arg
);
3576 case MEM_CANCEL_OFFLINE
:
3580 ret
= notifier_from_errno(ret
);
3586 static struct notifier_block slab_memory_callback_nb
= {
3587 .notifier_call
= slab_memory_callback
,
3588 .priority
= SLAB_CALLBACK_PRI
,
3591 /********************************************************************
3592 * Basic setup of slabs
3593 *******************************************************************/
3596 * Used for early kmem_cache structures that were allocated using
3597 * the page allocator. Allocate them properly then fix up the pointers
3598 * that may be pointing to the wrong kmem_cache structure.
3601 static struct kmem_cache
* __init
bootstrap(struct kmem_cache
*static_cache
)
3604 struct kmem_cache
*s
= kmem_cache_zalloc(kmem_cache
, GFP_NOWAIT
);
3606 memcpy(s
, static_cache
, kmem_cache
->object_size
);
3609 * This runs very early, and only the boot processor is supposed to be
3610 * up. Even if it weren't true, IRQs are not up so we couldn't fire
3613 __flush_cpu_slab(s
, smp_processor_id());
3614 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3615 struct kmem_cache_node
*n
= get_node(s
, node
);
3619 list_for_each_entry(p
, &n
->partial
, lru
)
3622 #ifdef CONFIG_SLUB_DEBUG
3623 list_for_each_entry(p
, &n
->full
, lru
)
3628 list_add(&s
->list
, &slab_caches
);
3632 void __init
kmem_cache_init(void)
3634 static __initdata
struct kmem_cache boot_kmem_cache
,
3635 boot_kmem_cache_node
;
3637 if (debug_guardpage_minorder())
3640 kmem_cache_node
= &boot_kmem_cache_node
;
3641 kmem_cache
= &boot_kmem_cache
;
3643 create_boot_cache(kmem_cache_node
, "kmem_cache_node",
3644 sizeof(struct kmem_cache_node
), SLAB_HWCACHE_ALIGN
);
3646 register_hotmemory_notifier(&slab_memory_callback_nb
);
3648 /* Able to allocate the per node structures */
3649 slab_state
= PARTIAL
;
3651 create_boot_cache(kmem_cache
, "kmem_cache",
3652 offsetof(struct kmem_cache
, node
) +
3653 nr_node_ids
* sizeof(struct kmem_cache_node
*),
3654 SLAB_HWCACHE_ALIGN
);
3656 kmem_cache
= bootstrap(&boot_kmem_cache
);
3659 * Allocate kmem_cache_node properly from the kmem_cache slab.
3660 * kmem_cache_node is separately allocated so no need to
3661 * update any list pointers.
3663 kmem_cache_node
= bootstrap(&boot_kmem_cache_node
);
3665 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3666 create_kmalloc_caches(0);
3669 register_cpu_notifier(&slab_notifier
);
3673 "SLUB: HWalign=%d, Order=%d-%d, MinObjects=%d,"
3674 " CPUs=%d, Nodes=%d\n",
3676 slub_min_order
, slub_max_order
, slub_min_objects
,
3677 nr_cpu_ids
, nr_node_ids
);
3680 void __init
kmem_cache_init_late(void)
3685 * Find a mergeable slab cache
3687 static int slab_unmergeable(struct kmem_cache
*s
)
3689 if (slub_nomerge
|| (s
->flags
& SLUB_NEVER_MERGE
))
3692 if (!is_root_cache(s
))
3699 * We may have set a slab to be unmergeable during bootstrap.
3701 if (s
->refcount
< 0)
3707 static struct kmem_cache
*find_mergeable(size_t size
, size_t align
,
3708 unsigned long flags
, const char *name
, void (*ctor
)(void *))
3710 struct kmem_cache
*s
;
3712 if (slub_nomerge
|| (flags
& SLUB_NEVER_MERGE
))
3718 size
= ALIGN(size
, sizeof(void *));
3719 align
= calculate_alignment(flags
, align
, size
);
3720 size
= ALIGN(size
, align
);
3721 flags
= kmem_cache_flags(size
, flags
, name
, NULL
);
3723 list_for_each_entry(s
, &slab_caches
, list
) {
3724 if (slab_unmergeable(s
))
3730 if ((flags
& SLUB_MERGE_SAME
) != (s
->flags
& SLUB_MERGE_SAME
))
3733 * Check if alignment is compatible.
3734 * Courtesy of Adrian Drzewiecki
3736 if ((s
->size
& ~(align
- 1)) != s
->size
)
3739 if (s
->size
- size
>= sizeof(void *))
3748 __kmem_cache_alias(const char *name
, size_t size
, size_t align
,
3749 unsigned long flags
, void (*ctor
)(void *))
3751 struct kmem_cache
*s
;
3753 s
= find_mergeable(size
, align
, flags
, name
, ctor
);
3756 struct kmem_cache
*c
;
3761 * Adjust the object sizes so that we clear
3762 * the complete object on kzalloc.
3764 s
->object_size
= max(s
->object_size
, (int)size
);
3765 s
->inuse
= max_t(int, s
->inuse
, ALIGN(size
, sizeof(void *)));
3767 for_each_memcg_cache_index(i
) {
3768 c
= cache_from_memcg_idx(s
, i
);
3771 c
->object_size
= s
->object_size
;
3772 c
->inuse
= max_t(int, c
->inuse
,
3773 ALIGN(size
, sizeof(void *)));
3776 if (sysfs_slab_alias(s
, name
)) {
3785 int __kmem_cache_create(struct kmem_cache
*s
, unsigned long flags
)
3789 err
= kmem_cache_open(s
, flags
);
3793 /* Mutex is not taken during early boot */
3794 if (slab_state
<= UP
)
3797 memcg_propagate_slab_attrs(s
);
3798 err
= sysfs_slab_add(s
);
3800 kmem_cache_close(s
);
3807 * Use the cpu notifier to insure that the cpu slabs are flushed when
3810 static int slab_cpuup_callback(struct notifier_block
*nfb
,
3811 unsigned long action
, void *hcpu
)
3813 long cpu
= (long)hcpu
;
3814 struct kmem_cache
*s
;
3815 unsigned long flags
;
3818 case CPU_UP_CANCELED
:
3819 case CPU_UP_CANCELED_FROZEN
:
3821 case CPU_DEAD_FROZEN
:
3822 mutex_lock(&slab_mutex
);
3823 list_for_each_entry(s
, &slab_caches
, list
) {
3824 local_irq_save(flags
);
3825 __flush_cpu_slab(s
, cpu
);
3826 local_irq_restore(flags
);
3828 mutex_unlock(&slab_mutex
);
3836 static struct notifier_block slab_notifier
= {
3837 .notifier_call
= slab_cpuup_callback
3842 void *__kmalloc_track_caller(size_t size
, gfp_t gfpflags
, unsigned long caller
)
3844 struct kmem_cache
*s
;
3847 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
))
3848 return kmalloc_large(size
, gfpflags
);
3850 s
= kmalloc_slab(size
, gfpflags
);
3852 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3855 ret
= slab_alloc(s
, gfpflags
, caller
);
3857 /* Honor the call site pointer we received. */
3858 trace_kmalloc(caller
, ret
, size
, s
->size
, gfpflags
);
3864 void *__kmalloc_node_track_caller(size_t size
, gfp_t gfpflags
,
3865 int node
, unsigned long caller
)
3867 struct kmem_cache
*s
;
3870 if (unlikely(size
> KMALLOC_MAX_CACHE_SIZE
)) {
3871 ret
= kmalloc_large_node(size
, gfpflags
, node
);
3873 trace_kmalloc_node(caller
, ret
,
3874 size
, PAGE_SIZE
<< get_order(size
),
3880 s
= kmalloc_slab(size
, gfpflags
);
3882 if (unlikely(ZERO_OR_NULL_PTR(s
)))
3885 ret
= slab_alloc_node(s
, gfpflags
, node
, caller
);
3887 /* Honor the call site pointer we received. */
3888 trace_kmalloc_node(caller
, ret
, size
, s
->size
, gfpflags
, node
);
3895 static int count_inuse(struct page
*page
)
3900 static int count_total(struct page
*page
)
3902 return page
->objects
;
3906 #ifdef CONFIG_SLUB_DEBUG
3907 static int validate_slab(struct kmem_cache
*s
, struct page
*page
,
3911 void *addr
= page_address(page
);
3913 if (!check_slab(s
, page
) ||
3914 !on_freelist(s
, page
, NULL
))
3917 /* Now we know that a valid freelist exists */
3918 bitmap_zero(map
, page
->objects
);
3920 get_map(s
, page
, map
);
3921 for_each_object(p
, s
, addr
, page
->objects
) {
3922 if (test_bit(slab_index(p
, s
, addr
), map
))
3923 if (!check_object(s
, page
, p
, SLUB_RED_INACTIVE
))
3927 for_each_object(p
, s
, addr
, page
->objects
)
3928 if (!test_bit(slab_index(p
, s
, addr
), map
))
3929 if (!check_object(s
, page
, p
, SLUB_RED_ACTIVE
))
3934 static void validate_slab_slab(struct kmem_cache
*s
, struct page
*page
,
3938 validate_slab(s
, page
, map
);
3942 static int validate_slab_node(struct kmem_cache
*s
,
3943 struct kmem_cache_node
*n
, unsigned long *map
)
3945 unsigned long count
= 0;
3947 unsigned long flags
;
3949 spin_lock_irqsave(&n
->list_lock
, flags
);
3951 list_for_each_entry(page
, &n
->partial
, lru
) {
3952 validate_slab_slab(s
, page
, map
);
3955 if (count
!= n
->nr_partial
)
3956 printk(KERN_ERR
"SLUB %s: %ld partial slabs counted but "
3957 "counter=%ld\n", s
->name
, count
, n
->nr_partial
);
3959 if (!(s
->flags
& SLAB_STORE_USER
))
3962 list_for_each_entry(page
, &n
->full
, lru
) {
3963 validate_slab_slab(s
, page
, map
);
3966 if (count
!= atomic_long_read(&n
->nr_slabs
))
3967 printk(KERN_ERR
"SLUB: %s %ld slabs counted but "
3968 "counter=%ld\n", s
->name
, count
,
3969 atomic_long_read(&n
->nr_slabs
));
3972 spin_unlock_irqrestore(&n
->list_lock
, flags
);
3976 static long validate_slab_cache(struct kmem_cache
*s
)
3979 unsigned long count
= 0;
3980 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
3981 sizeof(unsigned long), GFP_KERNEL
);
3987 for_each_node_state(node
, N_NORMAL_MEMORY
) {
3988 struct kmem_cache_node
*n
= get_node(s
, node
);
3990 count
+= validate_slab_node(s
, n
, map
);
3996 * Generate lists of code addresses where slabcache objects are allocated
4001 unsigned long count
;
4008 DECLARE_BITMAP(cpus
, NR_CPUS
);
4014 unsigned long count
;
4015 struct location
*loc
;
4018 static void free_loc_track(struct loc_track
*t
)
4021 free_pages((unsigned long)t
->loc
,
4022 get_order(sizeof(struct location
) * t
->max
));
4025 static int alloc_loc_track(struct loc_track
*t
, unsigned long max
, gfp_t flags
)
4030 order
= get_order(sizeof(struct location
) * max
);
4032 l
= (void *)__get_free_pages(flags
, order
);
4037 memcpy(l
, t
->loc
, sizeof(struct location
) * t
->count
);
4045 static int add_location(struct loc_track
*t
, struct kmem_cache
*s
,
4046 const struct track
*track
)
4048 long start
, end
, pos
;
4050 unsigned long caddr
;
4051 unsigned long age
= jiffies
- track
->when
;
4057 pos
= start
+ (end
- start
+ 1) / 2;
4060 * There is nothing at "end". If we end up there
4061 * we need to add something to before end.
4066 caddr
= t
->loc
[pos
].addr
;
4067 if (track
->addr
== caddr
) {
4073 if (age
< l
->min_time
)
4075 if (age
> l
->max_time
)
4078 if (track
->pid
< l
->min_pid
)
4079 l
->min_pid
= track
->pid
;
4080 if (track
->pid
> l
->max_pid
)
4081 l
->max_pid
= track
->pid
;
4083 cpumask_set_cpu(track
->cpu
,
4084 to_cpumask(l
->cpus
));
4086 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4090 if (track
->addr
< caddr
)
4097 * Not found. Insert new tracking element.
4099 if (t
->count
>= t
->max
&& !alloc_loc_track(t
, 2 * t
->max
, GFP_ATOMIC
))
4105 (t
->count
- pos
) * sizeof(struct location
));
4108 l
->addr
= track
->addr
;
4112 l
->min_pid
= track
->pid
;
4113 l
->max_pid
= track
->pid
;
4114 cpumask_clear(to_cpumask(l
->cpus
));
4115 cpumask_set_cpu(track
->cpu
, to_cpumask(l
->cpus
));
4116 nodes_clear(l
->nodes
);
4117 node_set(page_to_nid(virt_to_page(track
)), l
->nodes
);
4121 static void process_slab(struct loc_track
*t
, struct kmem_cache
*s
,
4122 struct page
*page
, enum track_item alloc
,
4125 void *addr
= page_address(page
);
4128 bitmap_zero(map
, page
->objects
);
4129 get_map(s
, page
, map
);
4131 for_each_object(p
, s
, addr
, page
->objects
)
4132 if (!test_bit(slab_index(p
, s
, addr
), map
))
4133 add_location(t
, s
, get_track(s
, p
, alloc
));
4136 static int list_locations(struct kmem_cache
*s
, char *buf
,
4137 enum track_item alloc
)
4141 struct loc_track t
= { 0, 0, NULL
};
4143 unsigned long *map
= kmalloc(BITS_TO_LONGS(oo_objects(s
->max
)) *
4144 sizeof(unsigned long), GFP_KERNEL
);
4146 if (!map
|| !alloc_loc_track(&t
, PAGE_SIZE
/ sizeof(struct location
),
4149 return sprintf(buf
, "Out of memory\n");
4151 /* Push back cpu slabs */
4154 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4155 struct kmem_cache_node
*n
= get_node(s
, node
);
4156 unsigned long flags
;
4159 if (!atomic_long_read(&n
->nr_slabs
))
4162 spin_lock_irqsave(&n
->list_lock
, flags
);
4163 list_for_each_entry(page
, &n
->partial
, lru
)
4164 process_slab(&t
, s
, page
, alloc
, map
);
4165 list_for_each_entry(page
, &n
->full
, lru
)
4166 process_slab(&t
, s
, page
, alloc
, map
);
4167 spin_unlock_irqrestore(&n
->list_lock
, flags
);
4170 for (i
= 0; i
< t
.count
; i
++) {
4171 struct location
*l
= &t
.loc
[i
];
4173 if (len
> PAGE_SIZE
- KSYM_SYMBOL_LEN
- 100)
4175 len
+= sprintf(buf
+ len
, "%7ld ", l
->count
);
4178 len
+= sprintf(buf
+ len
, "%pS", (void *)l
->addr
);
4180 len
+= sprintf(buf
+ len
, "<not-available>");
4182 if (l
->sum_time
!= l
->min_time
) {
4183 len
+= sprintf(buf
+ len
, " age=%ld/%ld/%ld",
4185 (long)div_u64(l
->sum_time
, l
->count
),
4188 len
+= sprintf(buf
+ len
, " age=%ld",
4191 if (l
->min_pid
!= l
->max_pid
)
4192 len
+= sprintf(buf
+ len
, " pid=%ld-%ld",
4193 l
->min_pid
, l
->max_pid
);
4195 len
+= sprintf(buf
+ len
, " pid=%ld",
4198 if (num_online_cpus() > 1 &&
4199 !cpumask_empty(to_cpumask(l
->cpus
)) &&
4200 len
< PAGE_SIZE
- 60) {
4201 len
+= sprintf(buf
+ len
, " cpus=");
4202 len
+= cpulist_scnprintf(buf
+ len
,
4203 PAGE_SIZE
- len
- 50,
4204 to_cpumask(l
->cpus
));
4207 if (nr_online_nodes
> 1 && !nodes_empty(l
->nodes
) &&
4208 len
< PAGE_SIZE
- 60) {
4209 len
+= sprintf(buf
+ len
, " nodes=");
4210 len
+= nodelist_scnprintf(buf
+ len
,
4211 PAGE_SIZE
- len
- 50,
4215 len
+= sprintf(buf
+ len
, "\n");
4221 len
+= sprintf(buf
, "No data\n");
4226 #ifdef SLUB_RESILIENCY_TEST
4227 static void resiliency_test(void)
4231 BUILD_BUG_ON(KMALLOC_MIN_SIZE
> 16 || KMALLOC_SHIFT_HIGH
< 10);
4233 printk(KERN_ERR
"SLUB resiliency testing\n");
4234 printk(KERN_ERR
"-----------------------\n");
4235 printk(KERN_ERR
"A. Corruption after allocation\n");
4237 p
= kzalloc(16, GFP_KERNEL
);
4239 printk(KERN_ERR
"\n1. kmalloc-16: Clobber Redzone/next pointer"
4240 " 0x12->0x%p\n\n", p
+ 16);
4242 validate_slab_cache(kmalloc_caches
[4]);
4244 /* Hmmm... The next two are dangerous */
4245 p
= kzalloc(32, GFP_KERNEL
);
4246 p
[32 + sizeof(void *)] = 0x34;
4247 printk(KERN_ERR
"\n2. kmalloc-32: Clobber next pointer/next slab"
4248 " 0x34 -> -0x%p\n", p
);
4250 "If allocated object is overwritten then not detectable\n\n");
4252 validate_slab_cache(kmalloc_caches
[5]);
4253 p
= kzalloc(64, GFP_KERNEL
);
4254 p
+= 64 + (get_cycles() & 0xff) * sizeof(void *);
4256 printk(KERN_ERR
"\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
4259 "If allocated object is overwritten then not detectable\n\n");
4260 validate_slab_cache(kmalloc_caches
[6]);
4262 printk(KERN_ERR
"\nB. Corruption after free\n");
4263 p
= kzalloc(128, GFP_KERNEL
);
4266 printk(KERN_ERR
"1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p
);
4267 validate_slab_cache(kmalloc_caches
[7]);
4269 p
= kzalloc(256, GFP_KERNEL
);
4272 printk(KERN_ERR
"\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
4274 validate_slab_cache(kmalloc_caches
[8]);
4276 p
= kzalloc(512, GFP_KERNEL
);
4279 printk(KERN_ERR
"\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p
);
4280 validate_slab_cache(kmalloc_caches
[9]);
4284 static void resiliency_test(void) {};
4289 enum slab_stat_type
{
4290 SL_ALL
, /* All slabs */
4291 SL_PARTIAL
, /* Only partially allocated slabs */
4292 SL_CPU
, /* Only slabs used for cpu caches */
4293 SL_OBJECTS
, /* Determine allocated objects not slabs */
4294 SL_TOTAL
/* Determine object capacity not slabs */
4297 #define SO_ALL (1 << SL_ALL)
4298 #define SO_PARTIAL (1 << SL_PARTIAL)
4299 #define SO_CPU (1 << SL_CPU)
4300 #define SO_OBJECTS (1 << SL_OBJECTS)
4301 #define SO_TOTAL (1 << SL_TOTAL)
4303 static ssize_t
show_slab_objects(struct kmem_cache
*s
,
4304 char *buf
, unsigned long flags
)
4306 unsigned long total
= 0;
4309 unsigned long *nodes
;
4311 nodes
= kzalloc(sizeof(unsigned long) * nr_node_ids
, GFP_KERNEL
);
4315 if (flags
& SO_CPU
) {
4318 for_each_possible_cpu(cpu
) {
4319 struct kmem_cache_cpu
*c
= per_cpu_ptr(s
->cpu_slab
,
4324 page
= ACCESS_ONCE(c
->page
);
4328 node
= page_to_nid(page
);
4329 if (flags
& SO_TOTAL
)
4331 else if (flags
& SO_OBJECTS
)
4339 page
= ACCESS_ONCE(c
->partial
);
4341 node
= page_to_nid(page
);
4342 if (flags
& SO_TOTAL
)
4344 else if (flags
& SO_OBJECTS
)
4354 lock_memory_hotplug();
4355 #ifdef CONFIG_SLUB_DEBUG
4356 if (flags
& SO_ALL
) {
4357 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4358 struct kmem_cache_node
*n
= get_node(s
, node
);
4360 if (flags
& SO_TOTAL
)
4361 x
= atomic_long_read(&n
->total_objects
);
4362 else if (flags
& SO_OBJECTS
)
4363 x
= atomic_long_read(&n
->total_objects
) -
4364 count_partial(n
, count_free
);
4366 x
= atomic_long_read(&n
->nr_slabs
);
4373 if (flags
& SO_PARTIAL
) {
4374 for_each_node_state(node
, N_NORMAL_MEMORY
) {
4375 struct kmem_cache_node
*n
= get_node(s
, node
);
4377 if (flags
& SO_TOTAL
)
4378 x
= count_partial(n
, count_total
);
4379 else if (flags
& SO_OBJECTS
)
4380 x
= count_partial(n
, count_inuse
);
4387 x
= sprintf(buf
, "%lu", total
);
4389 for_each_node_state(node
, N_NORMAL_MEMORY
)
4391 x
+= sprintf(buf
+ x
, " N%d=%lu",
4394 unlock_memory_hotplug();
4396 return x
+ sprintf(buf
+ x
, "\n");
4399 #ifdef CONFIG_SLUB_DEBUG
4400 static int any_slab_objects(struct kmem_cache
*s
)
4404 for_each_online_node(node
) {
4405 struct kmem_cache_node
*n
= get_node(s
, node
);
4410 if (atomic_long_read(&n
->total_objects
))
4417 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4418 #define to_slab(n) container_of(n, struct kmem_cache, kobj)
4420 struct slab_attribute
{
4421 struct attribute attr
;
4422 ssize_t (*show
)(struct kmem_cache
*s
, char *buf
);
4423 ssize_t (*store
)(struct kmem_cache
*s
, const char *x
, size_t count
);
4426 #define SLAB_ATTR_RO(_name) \
4427 static struct slab_attribute _name##_attr = \
4428 __ATTR(_name, 0400, _name##_show, NULL)
4430 #define SLAB_ATTR(_name) \
4431 static struct slab_attribute _name##_attr = \
4432 __ATTR(_name, 0600, _name##_show, _name##_store)
4434 static ssize_t
slab_size_show(struct kmem_cache
*s
, char *buf
)
4436 return sprintf(buf
, "%d\n", s
->size
);
4438 SLAB_ATTR_RO(slab_size
);
4440 static ssize_t
align_show(struct kmem_cache
*s
, char *buf
)
4442 return sprintf(buf
, "%d\n", s
->align
);
4444 SLAB_ATTR_RO(align
);
4446 static ssize_t
object_size_show(struct kmem_cache
*s
, char *buf
)
4448 return sprintf(buf
, "%d\n", s
->object_size
);
4450 SLAB_ATTR_RO(object_size
);
4452 static ssize_t
objs_per_slab_show(struct kmem_cache
*s
, char *buf
)
4454 return sprintf(buf
, "%d\n", oo_objects(s
->oo
));
4456 SLAB_ATTR_RO(objs_per_slab
);
4458 static ssize_t
order_store(struct kmem_cache
*s
,
4459 const char *buf
, size_t length
)
4461 unsigned long order
;
4464 err
= kstrtoul(buf
, 10, &order
);
4468 if (order
> slub_max_order
|| order
< slub_min_order
)
4471 calculate_sizes(s
, order
);
4475 static ssize_t
order_show(struct kmem_cache
*s
, char *buf
)
4477 return sprintf(buf
, "%d\n", oo_order(s
->oo
));
4481 static ssize_t
min_partial_show(struct kmem_cache
*s
, char *buf
)
4483 return sprintf(buf
, "%lu\n", s
->min_partial
);
4486 static ssize_t
min_partial_store(struct kmem_cache
*s
, const char *buf
,
4492 err
= kstrtoul(buf
, 10, &min
);
4496 set_min_partial(s
, min
);
4499 SLAB_ATTR(min_partial
);
4501 static ssize_t
cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4503 return sprintf(buf
, "%u\n", s
->cpu_partial
);
4506 static ssize_t
cpu_partial_store(struct kmem_cache
*s
, const char *buf
,
4509 unsigned long objects
;
4512 err
= kstrtoul(buf
, 10, &objects
);
4515 if (objects
&& !kmem_cache_has_cpu_partial(s
))
4518 s
->cpu_partial
= objects
;
4522 SLAB_ATTR(cpu_partial
);
4524 static ssize_t
ctor_show(struct kmem_cache
*s
, char *buf
)
4528 return sprintf(buf
, "%pS\n", s
->ctor
);
4532 static ssize_t
aliases_show(struct kmem_cache
*s
, char *buf
)
4534 return sprintf(buf
, "%d\n", s
->refcount
- 1);
4536 SLAB_ATTR_RO(aliases
);
4538 static ssize_t
partial_show(struct kmem_cache
*s
, char *buf
)
4540 return show_slab_objects(s
, buf
, SO_PARTIAL
);
4542 SLAB_ATTR_RO(partial
);
4544 static ssize_t
cpu_slabs_show(struct kmem_cache
*s
, char *buf
)
4546 return show_slab_objects(s
, buf
, SO_CPU
);
4548 SLAB_ATTR_RO(cpu_slabs
);
4550 static ssize_t
objects_show(struct kmem_cache
*s
, char *buf
)
4552 return show_slab_objects(s
, buf
, SO_ALL
|SO_OBJECTS
);
4554 SLAB_ATTR_RO(objects
);
4556 static ssize_t
objects_partial_show(struct kmem_cache
*s
, char *buf
)
4558 return show_slab_objects(s
, buf
, SO_PARTIAL
|SO_OBJECTS
);
4560 SLAB_ATTR_RO(objects_partial
);
4562 static ssize_t
slabs_cpu_partial_show(struct kmem_cache
*s
, char *buf
)
4569 for_each_online_cpu(cpu
) {
4570 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
)->partial
;
4573 pages
+= page
->pages
;
4574 objects
+= page
->pobjects
;
4578 len
= sprintf(buf
, "%d(%d)", objects
, pages
);
4581 for_each_online_cpu(cpu
) {
4582 struct page
*page
= per_cpu_ptr(s
->cpu_slab
, cpu
) ->partial
;
4584 if (page
&& len
< PAGE_SIZE
- 20)
4585 len
+= sprintf(buf
+ len
, " C%d=%d(%d)", cpu
,
4586 page
->pobjects
, page
->pages
);
4589 return len
+ sprintf(buf
+ len
, "\n");
4591 SLAB_ATTR_RO(slabs_cpu_partial
);
4593 static ssize_t
reclaim_account_show(struct kmem_cache
*s
, char *buf
)
4595 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RECLAIM_ACCOUNT
));
4598 static ssize_t
reclaim_account_store(struct kmem_cache
*s
,
4599 const char *buf
, size_t length
)
4601 s
->flags
&= ~SLAB_RECLAIM_ACCOUNT
;
4603 s
->flags
|= SLAB_RECLAIM_ACCOUNT
;
4606 SLAB_ATTR(reclaim_account
);
4608 static ssize_t
hwcache_align_show(struct kmem_cache
*s
, char *buf
)
4610 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_HWCACHE_ALIGN
));
4612 SLAB_ATTR_RO(hwcache_align
);
4614 #ifdef CONFIG_ZONE_DMA
4615 static ssize_t
cache_dma_show(struct kmem_cache
*s
, char *buf
)
4617 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_CACHE_DMA
));
4619 SLAB_ATTR_RO(cache_dma
);
4622 static ssize_t
destroy_by_rcu_show(struct kmem_cache
*s
, char *buf
)
4624 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DESTROY_BY_RCU
));
4626 SLAB_ATTR_RO(destroy_by_rcu
);
4628 static ssize_t
reserved_show(struct kmem_cache
*s
, char *buf
)
4630 return sprintf(buf
, "%d\n", s
->reserved
);
4632 SLAB_ATTR_RO(reserved
);
4634 #ifdef CONFIG_SLUB_DEBUG
4635 static ssize_t
slabs_show(struct kmem_cache
*s
, char *buf
)
4637 return show_slab_objects(s
, buf
, SO_ALL
);
4639 SLAB_ATTR_RO(slabs
);
4641 static ssize_t
total_objects_show(struct kmem_cache
*s
, char *buf
)
4643 return show_slab_objects(s
, buf
, SO_ALL
|SO_TOTAL
);
4645 SLAB_ATTR_RO(total_objects
);
4647 static ssize_t
sanity_checks_show(struct kmem_cache
*s
, char *buf
)
4649 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_DEBUG_FREE
));
4652 static ssize_t
sanity_checks_store(struct kmem_cache
*s
,
4653 const char *buf
, size_t length
)
4655 s
->flags
&= ~SLAB_DEBUG_FREE
;
4656 if (buf
[0] == '1') {
4657 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4658 s
->flags
|= SLAB_DEBUG_FREE
;
4662 SLAB_ATTR(sanity_checks
);
4664 static ssize_t
trace_show(struct kmem_cache
*s
, char *buf
)
4666 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_TRACE
));
4669 static ssize_t
trace_store(struct kmem_cache
*s
, const char *buf
,
4672 s
->flags
&= ~SLAB_TRACE
;
4673 if (buf
[0] == '1') {
4674 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4675 s
->flags
|= SLAB_TRACE
;
4681 static ssize_t
red_zone_show(struct kmem_cache
*s
, char *buf
)
4683 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_RED_ZONE
));
4686 static ssize_t
red_zone_store(struct kmem_cache
*s
,
4687 const char *buf
, size_t length
)
4689 if (any_slab_objects(s
))
4692 s
->flags
&= ~SLAB_RED_ZONE
;
4693 if (buf
[0] == '1') {
4694 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4695 s
->flags
|= SLAB_RED_ZONE
;
4697 calculate_sizes(s
, -1);
4700 SLAB_ATTR(red_zone
);
4702 static ssize_t
poison_show(struct kmem_cache
*s
, char *buf
)
4704 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_POISON
));
4707 static ssize_t
poison_store(struct kmem_cache
*s
,
4708 const char *buf
, size_t length
)
4710 if (any_slab_objects(s
))
4713 s
->flags
&= ~SLAB_POISON
;
4714 if (buf
[0] == '1') {
4715 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4716 s
->flags
|= SLAB_POISON
;
4718 calculate_sizes(s
, -1);
4723 static ssize_t
store_user_show(struct kmem_cache
*s
, char *buf
)
4725 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_STORE_USER
));
4728 static ssize_t
store_user_store(struct kmem_cache
*s
,
4729 const char *buf
, size_t length
)
4731 if (any_slab_objects(s
))
4734 s
->flags
&= ~SLAB_STORE_USER
;
4735 if (buf
[0] == '1') {
4736 s
->flags
&= ~__CMPXCHG_DOUBLE
;
4737 s
->flags
|= SLAB_STORE_USER
;
4739 calculate_sizes(s
, -1);
4742 SLAB_ATTR(store_user
);
4744 static ssize_t
validate_show(struct kmem_cache
*s
, char *buf
)
4749 static ssize_t
validate_store(struct kmem_cache
*s
,
4750 const char *buf
, size_t length
)
4754 if (buf
[0] == '1') {
4755 ret
= validate_slab_cache(s
);
4761 SLAB_ATTR(validate
);
4763 static ssize_t
alloc_calls_show(struct kmem_cache
*s
, char *buf
)
4765 if (!(s
->flags
& SLAB_STORE_USER
))
4767 return list_locations(s
, buf
, TRACK_ALLOC
);
4769 SLAB_ATTR_RO(alloc_calls
);
4771 static ssize_t
free_calls_show(struct kmem_cache
*s
, char *buf
)
4773 if (!(s
->flags
& SLAB_STORE_USER
))
4775 return list_locations(s
, buf
, TRACK_FREE
);
4777 SLAB_ATTR_RO(free_calls
);
4778 #endif /* CONFIG_SLUB_DEBUG */
4780 #ifdef CONFIG_FAILSLAB
4781 static ssize_t
failslab_show(struct kmem_cache
*s
, char *buf
)
4783 return sprintf(buf
, "%d\n", !!(s
->flags
& SLAB_FAILSLAB
));
4786 static ssize_t
failslab_store(struct kmem_cache
*s
, const char *buf
,
4789 s
->flags
&= ~SLAB_FAILSLAB
;
4791 s
->flags
|= SLAB_FAILSLAB
;
4794 SLAB_ATTR(failslab
);
4797 static ssize_t
shrink_show(struct kmem_cache
*s
, char *buf
)
4802 static ssize_t
shrink_store(struct kmem_cache
*s
,
4803 const char *buf
, size_t length
)
4805 if (buf
[0] == '1') {
4806 int rc
= kmem_cache_shrink(s
);
4817 static ssize_t
remote_node_defrag_ratio_show(struct kmem_cache
*s
, char *buf
)
4819 return sprintf(buf
, "%d\n", s
->remote_node_defrag_ratio
/ 10);
4822 static ssize_t
remote_node_defrag_ratio_store(struct kmem_cache
*s
,
4823 const char *buf
, size_t length
)
4825 unsigned long ratio
;
4828 err
= kstrtoul(buf
, 10, &ratio
);
4833 s
->remote_node_defrag_ratio
= ratio
* 10;
4837 SLAB_ATTR(remote_node_defrag_ratio
);
4840 #ifdef CONFIG_SLUB_STATS
4841 static int show_stat(struct kmem_cache
*s
, char *buf
, enum stat_item si
)
4843 unsigned long sum
= 0;
4846 int *data
= kmalloc(nr_cpu_ids
* sizeof(int), GFP_KERNEL
);
4851 for_each_online_cpu(cpu
) {
4852 unsigned x
= per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
];
4858 len
= sprintf(buf
, "%lu", sum
);
4861 for_each_online_cpu(cpu
) {
4862 if (data
[cpu
] && len
< PAGE_SIZE
- 20)
4863 len
+= sprintf(buf
+ len
, " C%d=%u", cpu
, data
[cpu
]);
4867 return len
+ sprintf(buf
+ len
, "\n");
4870 static void clear_stat(struct kmem_cache
*s
, enum stat_item si
)
4874 for_each_online_cpu(cpu
)
4875 per_cpu_ptr(s
->cpu_slab
, cpu
)->stat
[si
] = 0;
4878 #define STAT_ATTR(si, text) \
4879 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4881 return show_stat(s, buf, si); \
4883 static ssize_t text##_store(struct kmem_cache *s, \
4884 const char *buf, size_t length) \
4886 if (buf[0] != '0') \
4888 clear_stat(s, si); \
4893 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4894 STAT_ATTR(ALLOC_SLOWPATH
, alloc_slowpath
);
4895 STAT_ATTR(FREE_FASTPATH
, free_fastpath
);
4896 STAT_ATTR(FREE_SLOWPATH
, free_slowpath
);
4897 STAT_ATTR(FREE_FROZEN
, free_frozen
);
4898 STAT_ATTR(FREE_ADD_PARTIAL
, free_add_partial
);
4899 STAT_ATTR(FREE_REMOVE_PARTIAL
, free_remove_partial
);
4900 STAT_ATTR(ALLOC_FROM_PARTIAL
, alloc_from_partial
);
4901 STAT_ATTR(ALLOC_SLAB
, alloc_slab
);
4902 STAT_ATTR(ALLOC_REFILL
, alloc_refill
);
4903 STAT_ATTR(ALLOC_NODE_MISMATCH
, alloc_node_mismatch
);
4904 STAT_ATTR(FREE_SLAB
, free_slab
);
4905 STAT_ATTR(CPUSLAB_FLUSH
, cpuslab_flush
);
4906 STAT_ATTR(DEACTIVATE_FULL
, deactivate_full
);
4907 STAT_ATTR(DEACTIVATE_EMPTY
, deactivate_empty
);
4908 STAT_ATTR(DEACTIVATE_TO_HEAD
, deactivate_to_head
);
4909 STAT_ATTR(DEACTIVATE_TO_TAIL
, deactivate_to_tail
);
4910 STAT_ATTR(DEACTIVATE_REMOTE_FREES
, deactivate_remote_frees
);
4911 STAT_ATTR(DEACTIVATE_BYPASS
, deactivate_bypass
);
4912 STAT_ATTR(ORDER_FALLBACK
, order_fallback
);
4913 STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL
, cmpxchg_double_cpu_fail
);
4914 STAT_ATTR(CMPXCHG_DOUBLE_FAIL
, cmpxchg_double_fail
);
4915 STAT_ATTR(CPU_PARTIAL_ALLOC
, cpu_partial_alloc
);
4916 STAT_ATTR(CPU_PARTIAL_FREE
, cpu_partial_free
);
4917 STAT_ATTR(CPU_PARTIAL_NODE
, cpu_partial_node
);
4918 STAT_ATTR(CPU_PARTIAL_DRAIN
, cpu_partial_drain
);
4921 static struct attribute
*slab_attrs
[] = {
4922 &slab_size_attr
.attr
,
4923 &object_size_attr
.attr
,
4924 &objs_per_slab_attr
.attr
,
4926 &min_partial_attr
.attr
,
4927 &cpu_partial_attr
.attr
,
4929 &objects_partial_attr
.attr
,
4931 &cpu_slabs_attr
.attr
,
4935 &hwcache_align_attr
.attr
,
4936 &reclaim_account_attr
.attr
,
4937 &destroy_by_rcu_attr
.attr
,
4939 &reserved_attr
.attr
,
4940 &slabs_cpu_partial_attr
.attr
,
4941 #ifdef CONFIG_SLUB_DEBUG
4942 &total_objects_attr
.attr
,
4944 &sanity_checks_attr
.attr
,
4946 &red_zone_attr
.attr
,
4948 &store_user_attr
.attr
,
4949 &validate_attr
.attr
,
4950 &alloc_calls_attr
.attr
,
4951 &free_calls_attr
.attr
,
4953 #ifdef CONFIG_ZONE_DMA
4954 &cache_dma_attr
.attr
,
4957 &remote_node_defrag_ratio_attr
.attr
,
4959 #ifdef CONFIG_SLUB_STATS
4960 &alloc_fastpath_attr
.attr
,
4961 &alloc_slowpath_attr
.attr
,
4962 &free_fastpath_attr
.attr
,
4963 &free_slowpath_attr
.attr
,
4964 &free_frozen_attr
.attr
,
4965 &free_add_partial_attr
.attr
,
4966 &free_remove_partial_attr
.attr
,
4967 &alloc_from_partial_attr
.attr
,
4968 &alloc_slab_attr
.attr
,
4969 &alloc_refill_attr
.attr
,
4970 &alloc_node_mismatch_attr
.attr
,
4971 &free_slab_attr
.attr
,
4972 &cpuslab_flush_attr
.attr
,
4973 &deactivate_full_attr
.attr
,
4974 &deactivate_empty_attr
.attr
,
4975 &deactivate_to_head_attr
.attr
,
4976 &deactivate_to_tail_attr
.attr
,
4977 &deactivate_remote_frees_attr
.attr
,
4978 &deactivate_bypass_attr
.attr
,
4979 &order_fallback_attr
.attr
,
4980 &cmpxchg_double_fail_attr
.attr
,
4981 &cmpxchg_double_cpu_fail_attr
.attr
,
4982 &cpu_partial_alloc_attr
.attr
,
4983 &cpu_partial_free_attr
.attr
,
4984 &cpu_partial_node_attr
.attr
,
4985 &cpu_partial_drain_attr
.attr
,
4987 #ifdef CONFIG_FAILSLAB
4988 &failslab_attr
.attr
,
4994 static struct attribute_group slab_attr_group
= {
4995 .attrs
= slab_attrs
,
4998 static ssize_t
slab_attr_show(struct kobject
*kobj
,
4999 struct attribute
*attr
,
5002 struct slab_attribute
*attribute
;
5003 struct kmem_cache
*s
;
5006 attribute
= to_slab_attr(attr
);
5009 if (!attribute
->show
)
5012 err
= attribute
->show(s
, buf
);
5017 static ssize_t
slab_attr_store(struct kobject
*kobj
,
5018 struct attribute
*attr
,
5019 const char *buf
, size_t len
)
5021 struct slab_attribute
*attribute
;
5022 struct kmem_cache
*s
;
5025 attribute
= to_slab_attr(attr
);
5028 if (!attribute
->store
)
5031 err
= attribute
->store(s
, buf
, len
);
5032 #ifdef CONFIG_MEMCG_KMEM
5033 if (slab_state
>= FULL
&& err
>= 0 && is_root_cache(s
)) {
5036 mutex_lock(&slab_mutex
);
5037 if (s
->max_attr_size
< len
)
5038 s
->max_attr_size
= len
;
5041 * This is a best effort propagation, so this function's return
5042 * value will be determined by the parent cache only. This is
5043 * basically because not all attributes will have a well
5044 * defined semantics for rollbacks - most of the actions will
5045 * have permanent effects.
5047 * Returning the error value of any of the children that fail
5048 * is not 100 % defined, in the sense that users seeing the
5049 * error code won't be able to know anything about the state of
5052 * Only returning the error code for the parent cache at least
5053 * has well defined semantics. The cache being written to
5054 * directly either failed or succeeded, in which case we loop
5055 * through the descendants with best-effort propagation.
5057 for_each_memcg_cache_index(i
) {
5058 struct kmem_cache
*c
= cache_from_memcg_idx(s
, i
);
5060 attribute
->store(c
, buf
, len
);
5062 mutex_unlock(&slab_mutex
);
5068 static void memcg_propagate_slab_attrs(struct kmem_cache
*s
)
5070 #ifdef CONFIG_MEMCG_KMEM
5072 char *buffer
= NULL
;
5074 if (!is_root_cache(s
))
5078 * This mean this cache had no attribute written. Therefore, no point
5079 * in copying default values around
5081 if (!s
->max_attr_size
)
5084 for (i
= 0; i
< ARRAY_SIZE(slab_attrs
); i
++) {
5087 struct slab_attribute
*attr
= to_slab_attr(slab_attrs
[i
]);
5089 if (!attr
|| !attr
->store
|| !attr
->show
)
5093 * It is really bad that we have to allocate here, so we will
5094 * do it only as a fallback. If we actually allocate, though,
5095 * we can just use the allocated buffer until the end.
5097 * Most of the slub attributes will tend to be very small in
5098 * size, but sysfs allows buffers up to a page, so they can
5099 * theoretically happen.
5103 else if (s
->max_attr_size
< ARRAY_SIZE(mbuf
))
5106 buffer
= (char *) get_zeroed_page(GFP_KERNEL
);
5107 if (WARN_ON(!buffer
))
5112 attr
->show(s
->memcg_params
->root_cache
, buf
);
5113 attr
->store(s
, buf
, strlen(buf
));
5117 free_page((unsigned long)buffer
);
5121 static const struct sysfs_ops slab_sysfs_ops
= {
5122 .show
= slab_attr_show
,
5123 .store
= slab_attr_store
,
5126 static struct kobj_type slab_ktype
= {
5127 .sysfs_ops
= &slab_sysfs_ops
,
5130 static int uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
5132 struct kobj_type
*ktype
= get_ktype(kobj
);
5134 if (ktype
== &slab_ktype
)
5139 static const struct kset_uevent_ops slab_uevent_ops
= {
5140 .filter
= uevent_filter
,
5143 static struct kset
*slab_kset
;
5145 static inline struct kset
*cache_kset(struct kmem_cache
*s
)
5147 #ifdef CONFIG_MEMCG_KMEM
5148 if (!is_root_cache(s
))
5149 return s
->memcg_params
->root_cache
->memcg_kset
;
5154 #define ID_STR_LENGTH 64
5156 /* Create a unique string id for a slab cache:
5158 * Format :[flags-]size
5160 static char *create_unique_id(struct kmem_cache
*s
)
5162 char *name
= kmalloc(ID_STR_LENGTH
, GFP_KERNEL
);
5169 * First flags affecting slabcache operations. We will only
5170 * get here for aliasable slabs so we do not need to support
5171 * too many flags. The flags here must cover all flags that
5172 * are matched during merging to guarantee that the id is
5175 if (s
->flags
& SLAB_CACHE_DMA
)
5177 if (s
->flags
& SLAB_RECLAIM_ACCOUNT
)
5179 if (s
->flags
& SLAB_DEBUG_FREE
)
5181 if (!(s
->flags
& SLAB_NOTRACK
))
5185 p
+= sprintf(p
, "%07d", s
->size
);
5187 #ifdef CONFIG_MEMCG_KMEM
5188 if (!is_root_cache(s
))
5189 p
+= sprintf(p
, "-%08d",
5190 memcg_cache_id(s
->memcg_params
->memcg
));
5193 BUG_ON(p
> name
+ ID_STR_LENGTH
- 1);
5197 static int sysfs_slab_add(struct kmem_cache
*s
)
5201 int unmergeable
= slab_unmergeable(s
);
5205 * Slabcache can never be merged so we can use the name proper.
5206 * This is typically the case for debug situations. In that
5207 * case we can catch duplicate names easily.
5209 sysfs_remove_link(&slab_kset
->kobj
, s
->name
);
5213 * Create a unique name for the slab as a target
5216 name
= create_unique_id(s
);
5219 s
->kobj
.kset
= cache_kset(s
);
5220 err
= kobject_init_and_add(&s
->kobj
, &slab_ktype
, NULL
, "%s", name
);
5224 err
= sysfs_create_group(&s
->kobj
, &slab_attr_group
);
5228 #ifdef CONFIG_MEMCG_KMEM
5229 if (is_root_cache(s
)) {
5230 s
->memcg_kset
= kset_create_and_add("cgroup", NULL
, &s
->kobj
);
5231 if (!s
->memcg_kset
) {
5238 kobject_uevent(&s
->kobj
, KOBJ_ADD
);
5240 /* Setup first alias */
5241 sysfs_slab_alias(s
, s
->name
);
5248 kobject_del(&s
->kobj
);
5250 kobject_put(&s
->kobj
);
5254 static void sysfs_slab_remove(struct kmem_cache
*s
)
5256 if (slab_state
< FULL
)
5258 * Sysfs has not been setup yet so no need to remove the
5263 #ifdef CONFIG_MEMCG_KMEM
5264 kset_unregister(s
->memcg_kset
);
5266 kobject_uevent(&s
->kobj
, KOBJ_REMOVE
);
5267 kobject_del(&s
->kobj
);
5268 kobject_put(&s
->kobj
);
5272 * Need to buffer aliases during bootup until sysfs becomes
5273 * available lest we lose that information.
5275 struct saved_alias
{
5276 struct kmem_cache
*s
;
5278 struct saved_alias
*next
;
5281 static struct saved_alias
*alias_list
;
5283 static int sysfs_slab_alias(struct kmem_cache
*s
, const char *name
)
5285 struct saved_alias
*al
;
5287 if (slab_state
== FULL
) {
5289 * If we have a leftover link then remove it.
5291 sysfs_remove_link(&slab_kset
->kobj
, name
);
5292 return sysfs_create_link(&slab_kset
->kobj
, &s
->kobj
, name
);
5295 al
= kmalloc(sizeof(struct saved_alias
), GFP_KERNEL
);
5301 al
->next
= alias_list
;
5306 static int __init
slab_sysfs_init(void)
5308 struct kmem_cache
*s
;
5311 mutex_lock(&slab_mutex
);
5313 slab_kset
= kset_create_and_add("slab", &slab_uevent_ops
, kernel_kobj
);
5315 mutex_unlock(&slab_mutex
);
5316 printk(KERN_ERR
"Cannot register slab subsystem.\n");
5322 list_for_each_entry(s
, &slab_caches
, list
) {
5323 err
= sysfs_slab_add(s
);
5325 printk(KERN_ERR
"SLUB: Unable to add boot slab %s"
5326 " to sysfs\n", s
->name
);
5329 while (alias_list
) {
5330 struct saved_alias
*al
= alias_list
;
5332 alias_list
= alias_list
->next
;
5333 err
= sysfs_slab_alias(al
->s
, al
->name
);
5335 printk(KERN_ERR
"SLUB: Unable to add boot slab alias"
5336 " %s to sysfs\n", al
->name
);
5340 mutex_unlock(&slab_mutex
);
5345 __initcall(slab_sysfs_init
);
5346 #endif /* CONFIG_SYSFS */
5349 * The /proc/slabinfo ABI
5351 #ifdef CONFIG_SLABINFO
5352 void get_slabinfo(struct kmem_cache
*s
, struct slabinfo
*sinfo
)
5354 unsigned long nr_slabs
= 0;
5355 unsigned long nr_objs
= 0;
5356 unsigned long nr_free
= 0;
5359 for_each_online_node(node
) {
5360 struct kmem_cache_node
*n
= get_node(s
, node
);
5365 nr_slabs
+= node_nr_slabs(n
);
5366 nr_objs
+= node_nr_objs(n
);
5367 nr_free
+= count_partial(n
, count_free
);
5370 sinfo
->active_objs
= nr_objs
- nr_free
;
5371 sinfo
->num_objs
= nr_objs
;
5372 sinfo
->active_slabs
= nr_slabs
;
5373 sinfo
->num_slabs
= nr_slabs
;
5374 sinfo
->objects_per_slab
= oo_objects(s
->oo
);
5375 sinfo
->cache_order
= oo_order(s
->oo
);
5378 void slabinfo_show_stats(struct seq_file
*m
, struct kmem_cache
*s
)
5382 ssize_t
slabinfo_write(struct file
*file
, const char __user
*buffer
,
5383 size_t count
, loff_t
*ppos
)
5387 #endif /* CONFIG_SLABINFO */