2 * SLUB: A slab allocator that limits cache line use instead of queuing
3 * objects in per cpu and per node lists.
5 * The allocator synchronizes using per slab locks and only
6 * uses a centralized lock to manage a pool of partial slabs.
8 * (C) 2007 SGI, Christoph Lameter
12 #include <linux/swap.h> /* struct reclaim_state */
13 #include <linux/module.h>
14 #include <linux/bit_spinlock.h>
15 #include <linux/interrupt.h>
16 #include <linux/bitops.h>
17 #include <linux/slab.h>
18 #include <linux/proc_fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/kmemcheck.h>
21 #include <linux/cpu.h>
22 #include <linux/cpuset.h>
23 #include <linux/mempolicy.h>
24 #include <linux/ctype.h>
25 #include <linux/debugobjects.h>
26 #include <linux/kallsyms.h>
27 #include <linux/memory.h>
28 #include <linux/math64.h>
29 #include <linux/fault-inject.h>
31 #include <trace/events/kmem.h>
38 * The slab_lock protects operations on the object of a particular
39 * slab and its metadata in the page struct. If the slab lock
40 * has been taken then no allocations nor frees can be performed
41 * on the objects in the slab nor can the slab be added or removed
42 * from the partial or full lists since this would mean modifying
43 * the page_struct of the slab.
45 * The list_lock protects the partial and full list on each node and
46 * the partial slab counter. If taken then no new slabs may be added or
47 * removed from the lists nor make the number of partial slabs be modified.
48 * (Note that the total number of slabs is an atomic value that may be
49 * modified without taking the list lock).
51 * The list_lock is a centralized lock and thus we avoid taking it as
52 * much as possible. As long as SLUB does not have to handle partial
53 * slabs, operations can continue without any centralized lock. F.e.
54 * allocating a long series of objects that fill up slabs does not require
57 * The lock order is sometimes inverted when we are trying to get a slab
58 * off a list. We take the list_lock and then look for a page on the list
59 * to use. While we do that objects in the slabs may be freed. We can
60 * only operate on the slab if we have also taken the slab_lock. So we use
61 * a slab_trylock() on the slab. If trylock was successful then no frees
62 * can occur anymore and we can use the slab for allocations etc. If the
63 * slab_trylock() does not succeed then frees are in progress in the slab and
64 * we must stay away from it for a while since we may cause a bouncing
65 * cacheline if we try to acquire the lock. So go onto the next slab.
66 * If all pages are busy then we may allocate a new slab instead of reusing
67 * a partial slab. A new slab has noone operating on it and thus there is
68 * no danger of cacheline contention.
70 * Interrupts are disabled during allocation and deallocation in order to
71 * make the slab allocator safe to use in the context of an irq. In addition
72 * interrupts are disabled to ensure that the processor does not change
73 * while handling per_cpu slabs, due to kernel preemption.
75 * SLUB assigns one slab for allocation to each processor.
76 * Allocations only occur from these slabs called cpu slabs.
78 * Slabs with free elements are kept on a partial list and during regular
79 * operations no list for full slabs is used. If an object in a full slab is
80 * freed then the slab will show up again on the partial lists.
81 * We track full slabs for debugging purposes though because otherwise we
82 * cannot scan all objects.
84 * Slabs are freed when they become empty. Teardown and setup is
85 * minimal so we rely on the page allocators per cpu caches for
86 * fast frees and allocs.
88 * Overloading of page flags that are otherwise used for LRU management.
90 * PageActive The slab is frozen and exempt from list processing.
91 * This means that the slab is dedicated to a purpose
92 * such as satisfying allocations for a specific
93 * processor. Objects may be freed in the slab while
94 * it is frozen but slab_free will then skip the usual
95 * list operations. It is up to the processor holding
96 * the slab to integrate the slab into the slab lists
97 * when the slab is no longer needed.
99 * One use of this flag is to mark slabs that are
100 * used for allocations. Then such a slab becomes a cpu
101 * slab. The cpu slab may be equipped with an additional
102 * freelist that allows lockless access to
103 * free objects in addition to the regular freelist
104 * that requires the slab lock.
106 * PageError Slab requires special handling due to debug
107 * options set. This moves slab handling out of
108 * the fast path and disables lockless freelists.
111 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
112 SLAB_TRACE | SLAB_DEBUG_FREE)
114 static inline int kmem_cache_debug(struct kmem_cache *s)
116 #ifdef CONFIG_SLUB_DEBUG
117 return unlikely(s->flags & SLAB_DEBUG_FLAGS);
124 * Issues still to be resolved:
126 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
128 * - Variable sizing of the per node arrays
131 /* Enable to test recovery from slab corruption on boot */
132 #undef SLUB_RESILIENCY_TEST
135 * Mininum number of partial slabs. These will be left on the partial
136 * lists even if they are empty. kmem_cache_shrink may reclaim them.
138 #define MIN_PARTIAL 5
141 * Maximum number of desirable partial slabs.
142 * The existence of more partial slabs makes kmem_cache_shrink
143 * sort the partial list by the number of objects in the.
145 #define MAX_PARTIAL 10
147 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
148 SLAB_POISON | SLAB_STORE_USER)
151 * Debugging flags that require metadata to be stored in the slab. These get
152 * disabled when slub_debug=O is used and a cache's min order increases with
155 #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
158 * Set of flags that will prevent slab merging
160 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
161 SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
164 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
165 SLAB_CACHE_DMA | SLAB_NOTRACK)
168 #define OO_MASK ((1 << OO_SHIFT) - 1)
169 #define MAX_OBJS_PER_PAGE 65535 /* since page.objects is u16 */
171 /* Internal SLUB flags */
172 #define __OBJECT_POISON 0x80000000UL /* Poison object */
174 static int kmem_size = sizeof(struct kmem_cache);
177 static struct notifier_block slab_notifier;
181 DOWN, /* No slab functionality available */
182 PARTIAL, /* Kmem_cache_node works */
183 UP, /* Everything works but does not show up in sysfs */
187 /* A list of all slab caches on the system */
188 static DECLARE_RWSEM(slub_lock);
189 static LIST_HEAD(slab_caches);
192 * Tracking user of a slab.
195 unsigned long addr; /* Called from address */
196 int cpu; /* Was running on cpu */
197 int pid; /* Pid context */
198 unsigned long when; /* When did the operation occur */
201 enum track_item { TRACK_ALLOC, TRACK_FREE };
204 static int sysfs_slab_add(struct kmem_cache *);
205 static int sysfs_slab_alias(struct kmem_cache *, const char *);
206 static void sysfs_slab_remove(struct kmem_cache *);
209 static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
210 static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
212 static inline void sysfs_slab_remove(struct kmem_cache *s)
220 static inline void stat(struct kmem_cache *s, enum stat_item si)
222 #ifdef CONFIG_SLUB_STATS
223 __this_cpu_inc(s->cpu_slab->stat[si]);
227 /********************************************************************
228 * Core slab cache functions
229 *******************************************************************/
231 int slab_is_available(void)
233 return slab_state >= UP;
236 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
238 return s->node[node];
241 /* Verify that a pointer has an address that is valid within a slab page */
242 static inline int check_valid_pointer(struct kmem_cache *s,
243 struct page *page, const void *object)
250 base = page_address(page);
251 if (object < base || object >= base + page->objects * s->size ||
252 (object - base) % s->size) {
259 static inline void *get_freepointer(struct kmem_cache *s, void *object)
261 return *(void **)(object + s->offset);
264 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
266 *(void **)(object + s->offset) = fp;
269 /* Loop over all objects in a slab */
270 #define for_each_object(__p, __s, __addr, __objects) \
271 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
275 #define for_each_free_object(__p, __s, __free) \
276 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
278 /* Determine object index from a given position */
279 static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
281 return (p - addr) / s->size;
284 static inline struct kmem_cache_order_objects oo_make(int order,
287 struct kmem_cache_order_objects x = {
288 (order << OO_SHIFT) + (PAGE_SIZE << order) / size
294 static inline int oo_order(struct kmem_cache_order_objects x)
296 return x.x >> OO_SHIFT;
299 static inline int oo_objects(struct kmem_cache_order_objects x)
301 return x.x & OO_MASK;
304 #ifdef CONFIG_SLUB_DEBUG
308 #ifdef CONFIG_SLUB_DEBUG_ON
309 static int slub_debug = DEBUG_DEFAULT_FLAGS;
311 static int slub_debug;
314 static char *slub_debug_slabs;
315 static int disable_higher_order_debug;
320 static void print_section(char *text, u8 *addr, unsigned int length)
328 for (i = 0; i < length; i++) {
330 printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
333 printk(KERN_CONT " %02x", addr[i]);
335 ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
337 printk(KERN_CONT " %s\n", ascii);
344 printk(KERN_CONT " ");
348 printk(KERN_CONT " %s\n", ascii);
352 static struct track *get_track(struct kmem_cache *s, void *object,
353 enum track_item alloc)
358 p = object + s->offset + sizeof(void *);
360 p = object + s->inuse;
365 static void set_track(struct kmem_cache *s, void *object,
366 enum track_item alloc, unsigned long addr)
368 struct track *p = get_track(s, object, alloc);
372 p->cpu = smp_processor_id();
373 p->pid = current->pid;
376 memset(p, 0, sizeof(struct track));
379 static void init_tracking(struct kmem_cache *s, void *object)
381 if (!(s->flags & SLAB_STORE_USER))
384 set_track(s, object, TRACK_FREE, 0UL);
385 set_track(s, object, TRACK_ALLOC, 0UL);
388 static void print_track(const char *s, struct track *t)
393 printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
394 s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid);
397 static void print_tracking(struct kmem_cache *s, void *object)
399 if (!(s->flags & SLAB_STORE_USER))
402 print_track("Allocated", get_track(s, object, TRACK_ALLOC));
403 print_track("Freed", get_track(s, object, TRACK_FREE));
406 static void print_page_info(struct page *page)
408 printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
409 page, page->objects, page->inuse, page->freelist, page->flags);
413 static void slab_bug(struct kmem_cache *s, char *fmt, ...)
419 vsnprintf(buf, sizeof(buf), fmt, args);
421 printk(KERN_ERR "========================================"
422 "=====================================\n");
423 printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
424 printk(KERN_ERR "----------------------------------------"
425 "-------------------------------------\n\n");
428 static void slab_fix(struct kmem_cache *s, char *fmt, ...)
434 vsnprintf(buf, sizeof(buf), fmt, args);
436 printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
439 static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
441 unsigned int off; /* Offset of last byte */
442 u8 *addr = page_address(page);
444 print_tracking(s, p);
446 print_page_info(page);
448 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
449 p, p - addr, get_freepointer(s, p));
452 print_section("Bytes b4", p - 16, 16);
454 print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE));
456 if (s->flags & SLAB_RED_ZONE)
457 print_section("Redzone", p + s->objsize,
458 s->inuse - s->objsize);
461 off = s->offset + sizeof(void *);
465 if (s->flags & SLAB_STORE_USER)
466 off += 2 * sizeof(struct track);
469 /* Beginning of the filler is the free pointer */
470 print_section("Padding", p + off, s->size - off);
475 static void object_err(struct kmem_cache *s, struct page *page,
476 u8 *object, char *reason)
478 slab_bug(s, "%s", reason);
479 print_trailer(s, page, object);
482 static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
488 vsnprintf(buf, sizeof(buf), fmt, args);
490 slab_bug(s, "%s", buf);
491 print_page_info(page);
495 static void init_object(struct kmem_cache *s, void *object, u8 val)
499 if (s->flags & __OBJECT_POISON) {
500 memset(p, POISON_FREE, s->objsize - 1);
501 p[s->objsize - 1] = POISON_END;
504 if (s->flags & SLAB_RED_ZONE)
505 memset(p + s->objsize, val, s->inuse - s->objsize);
508 static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes)
511 if (*start != (u8)value)
519 static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
520 void *from, void *to)
522 slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
523 memset(from, data, to - from);
526 static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
527 u8 *object, char *what,
528 u8 *start, unsigned int value, unsigned int bytes)
533 fault = check_bytes(start, value, bytes);
538 while (end > fault && end[-1] == value)
541 slab_bug(s, "%s overwritten", what);
542 printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
543 fault, end - 1, fault[0], value);
544 print_trailer(s, page, object);
546 restore_bytes(s, what, value, fault, end);
554 * Bytes of the object to be managed.
555 * If the freepointer may overlay the object then the free
556 * pointer is the first word of the object.
558 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
561 * object + s->objsize
562 * Padding to reach word boundary. This is also used for Redzoning.
563 * Padding is extended by another word if Redzoning is enabled and
566 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
567 * 0xcc (RED_ACTIVE) for objects in use.
570 * Meta data starts here.
572 * A. Free pointer (if we cannot overwrite object on free)
573 * B. Tracking data for SLAB_STORE_USER
574 * C. Padding to reach required alignment boundary or at mininum
575 * one word if debugging is on to be able to detect writes
576 * before the word boundary.
578 * Padding is done using 0x5a (POISON_INUSE)
581 * Nothing is used beyond s->size.
583 * If slabcaches are merged then the objsize and inuse boundaries are mostly
584 * ignored. And therefore no slab options that rely on these boundaries
585 * may be used with merged slabcaches.
588 static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
590 unsigned long off = s->inuse; /* The end of info */
593 /* Freepointer is placed after the object. */
594 off += sizeof(void *);
596 if (s->flags & SLAB_STORE_USER)
597 /* We also have user information there */
598 off += 2 * sizeof(struct track);
603 return check_bytes_and_report(s, page, p, "Object padding",
604 p + off, POISON_INUSE, s->size - off);
607 /* Check the pad bytes at the end of a slab page */
608 static int slab_pad_check(struct kmem_cache *s, struct page *page)
616 if (!(s->flags & SLAB_POISON))
619 start = page_address(page);
620 length = (PAGE_SIZE << compound_order(page));
621 end = start + length;
622 remainder = length % s->size;
626 fault = check_bytes(end - remainder, POISON_INUSE, remainder);
629 while (end > fault && end[-1] == POISON_INUSE)
632 slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
633 print_section("Padding", end - remainder, remainder);
635 restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
639 static int check_object(struct kmem_cache *s, struct page *page,
640 void *object, u8 val)
643 u8 *endobject = object + s->objsize;
645 if (s->flags & SLAB_RED_ZONE) {
646 if (!check_bytes_and_report(s, page, object, "Redzone",
647 endobject, val, s->inuse - s->objsize))
650 if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
651 check_bytes_and_report(s, page, p, "Alignment padding",
652 endobject, POISON_INUSE, s->inuse - s->objsize);
656 if (s->flags & SLAB_POISON) {
657 if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) &&
658 (!check_bytes_and_report(s, page, p, "Poison", p,
659 POISON_FREE, s->objsize - 1) ||
660 !check_bytes_and_report(s, page, p, "Poison",
661 p + s->objsize - 1, POISON_END, 1)))
664 * check_pad_bytes cleans up on its own.
666 check_pad_bytes(s, page, p);
669 if (!s->offset && val == SLUB_RED_ACTIVE)
671 * Object and freepointer overlap. Cannot check
672 * freepointer while object is allocated.
676 /* Check free pointer validity */
677 if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
678 object_err(s, page, p, "Freepointer corrupt");
680 * No choice but to zap it and thus lose the remainder
681 * of the free objects in this slab. May cause
682 * another error because the object count is now wrong.
684 set_freepointer(s, p, NULL);
690 static int check_slab(struct kmem_cache *s, struct page *page)
694 VM_BUG_ON(!irqs_disabled());
696 if (!PageSlab(page)) {
697 slab_err(s, page, "Not a valid slab page");
701 maxobj = (PAGE_SIZE << compound_order(page)) / s->size;
702 if (page->objects > maxobj) {
703 slab_err(s, page, "objects %u > max %u",
704 s->name, page->objects, maxobj);
707 if (page->inuse > page->objects) {
708 slab_err(s, page, "inuse %u > max %u",
709 s->name, page->inuse, page->objects);
712 /* Slab_pad_check fixes things up after itself */
713 slab_pad_check(s, page);
718 * Determine if a certain object on a page is on the freelist. Must hold the
719 * slab lock to guarantee that the chains are in a consistent state.
721 static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
724 void *fp = page->freelist;
726 unsigned long max_objects;
728 while (fp && nr <= page->objects) {
731 if (!check_valid_pointer(s, page, fp)) {
733 object_err(s, page, object,
734 "Freechain corrupt");
735 set_freepointer(s, object, NULL);
738 slab_err(s, page, "Freepointer corrupt");
739 page->freelist = NULL;
740 page->inuse = page->objects;
741 slab_fix(s, "Freelist cleared");
747 fp = get_freepointer(s, object);
751 max_objects = (PAGE_SIZE << compound_order(page)) / s->size;
752 if (max_objects > MAX_OBJS_PER_PAGE)
753 max_objects = MAX_OBJS_PER_PAGE;
755 if (page->objects != max_objects) {
756 slab_err(s, page, "Wrong number of objects. Found %d but "
757 "should be %d", page->objects, max_objects);
758 page->objects = max_objects;
759 slab_fix(s, "Number of objects adjusted.");
761 if (page->inuse != page->objects - nr) {
762 slab_err(s, page, "Wrong object count. Counter is %d but "
763 "counted were %d", page->inuse, page->objects - nr);
764 page->inuse = page->objects - nr;
765 slab_fix(s, "Object count adjusted.");
767 return search == NULL;
770 static void trace(struct kmem_cache *s, struct page *page, void *object,
773 if (s->flags & SLAB_TRACE) {
774 printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
776 alloc ? "alloc" : "free",
781 print_section("Object", (void *)object, s->objsize);
788 * Hooks for other subsystems that check memory allocations. In a typical
789 * production configuration these hooks all should produce no code at all.
791 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
793 flags &= gfp_allowed_mask;
794 lockdep_trace_alloc(flags);
795 might_sleep_if(flags & __GFP_WAIT);
797 return should_failslab(s->objsize, flags, s->flags);
800 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object)
802 flags &= gfp_allowed_mask;
803 kmemcheck_slab_alloc(s, flags, object, s->objsize);
804 kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags);
807 static inline void slab_free_hook(struct kmem_cache *s, void *x)
809 kmemleak_free_recursive(x, s->flags);
812 * Trouble is that we may no longer disable interupts in the fast path
813 * So in order to make the debug calls that expect irqs to be
814 * disabled we need to disable interrupts temporarily.
816 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
820 local_irq_save(flags);
821 kmemcheck_slab_free(s, x, s->objsize);
822 debug_check_no_locks_freed(x, s->objsize);
823 if (!(s->flags & SLAB_DEBUG_OBJECTS))
824 debug_check_no_obj_freed(x, s->objsize);
825 local_irq_restore(flags);
831 * Tracking of fully allocated slabs for debugging purposes.
833 static void add_full(struct kmem_cache_node *n, struct page *page)
835 spin_lock(&n->list_lock);
836 list_add(&page->lru, &n->full);
837 spin_unlock(&n->list_lock);
840 static void remove_full(struct kmem_cache *s, struct page *page)
842 struct kmem_cache_node *n;
844 if (!(s->flags & SLAB_STORE_USER))
847 n = get_node(s, page_to_nid(page));
849 spin_lock(&n->list_lock);
850 list_del(&page->lru);
851 spin_unlock(&n->list_lock);
854 /* Tracking of the number of slabs for debugging purposes */
855 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
857 struct kmem_cache_node *n = get_node(s, node);
859 return atomic_long_read(&n->nr_slabs);
862 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
864 return atomic_long_read(&n->nr_slabs);
867 static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
869 struct kmem_cache_node *n = get_node(s, node);
872 * May be called early in order to allocate a slab for the
873 * kmem_cache_node structure. Solve the chicken-egg
874 * dilemma by deferring the increment of the count during
875 * bootstrap (see early_kmem_cache_node_alloc).
878 atomic_long_inc(&n->nr_slabs);
879 atomic_long_add(objects, &n->total_objects);
882 static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
884 struct kmem_cache_node *n = get_node(s, node);
886 atomic_long_dec(&n->nr_slabs);
887 atomic_long_sub(objects, &n->total_objects);
890 /* Object debug checks for alloc/free paths */
891 static void setup_object_debug(struct kmem_cache *s, struct page *page,
894 if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
897 init_object(s, object, SLUB_RED_INACTIVE);
898 init_tracking(s, object);
901 static noinline int alloc_debug_processing(struct kmem_cache *s, struct page *page,
902 void *object, unsigned long addr)
904 if (!check_slab(s, page))
907 if (!on_freelist(s, page, object)) {
908 object_err(s, page, object, "Object already allocated");
912 if (!check_valid_pointer(s, page, object)) {
913 object_err(s, page, object, "Freelist Pointer check fails");
917 if (!check_object(s, page, object, SLUB_RED_INACTIVE))
920 /* Success perform special debug activities for allocs */
921 if (s->flags & SLAB_STORE_USER)
922 set_track(s, object, TRACK_ALLOC, addr);
923 trace(s, page, object, 1);
924 init_object(s, object, SLUB_RED_ACTIVE);
928 if (PageSlab(page)) {
930 * If this is a slab page then lets do the best we can
931 * to avoid issues in the future. Marking all objects
932 * as used avoids touching the remaining objects.
934 slab_fix(s, "Marking all objects used");
935 page->inuse = page->objects;
936 page->freelist = NULL;
941 static noinline int free_debug_processing(struct kmem_cache *s,
942 struct page *page, void *object, unsigned long addr)
944 if (!check_slab(s, page))
947 if (!check_valid_pointer(s, page, object)) {
948 slab_err(s, page, "Invalid object pointer 0x%p", object);
952 if (on_freelist(s, page, object)) {
953 object_err(s, page, object, "Object already free");
957 if (!check_object(s, page, object, SLUB_RED_ACTIVE))
960 if (unlikely(s != page->slab)) {
961 if (!PageSlab(page)) {
962 slab_err(s, page, "Attempt to free object(0x%p) "
963 "outside of slab", object);
964 } else if (!page->slab) {
966 "SLUB <none>: no slab for object 0x%p.\n",
970 object_err(s, page, object,
971 "page slab pointer corrupt.");
975 /* Special debug activities for freeing objects */
976 if (!PageSlubFrozen(page) && !page->freelist)
977 remove_full(s, page);
978 if (s->flags & SLAB_STORE_USER)
979 set_track(s, object, TRACK_FREE, addr);
980 trace(s, page, object, 0);
981 init_object(s, object, SLUB_RED_INACTIVE);
985 slab_fix(s, "Object at 0x%p not freed", object);
989 static int __init setup_slub_debug(char *str)
991 slub_debug = DEBUG_DEFAULT_FLAGS;
992 if (*str++ != '=' || !*str)
994 * No options specified. Switch on full debugging.
1000 * No options but restriction on slabs. This means full
1001 * debugging for slabs matching a pattern.
1005 if (tolower(*str) == 'o') {
1007 * Avoid enabling debugging on caches if its minimum order
1008 * would increase as a result.
1010 disable_higher_order_debug = 1;
1017 * Switch off all debugging measures.
1022 * Determine which debug features should be switched on
1024 for (; *str && *str != ','; str++) {
1025 switch (tolower(*str)) {
1027 slub_debug |= SLAB_DEBUG_FREE;
1030 slub_debug |= SLAB_RED_ZONE;
1033 slub_debug |= SLAB_POISON;
1036 slub_debug |= SLAB_STORE_USER;
1039 slub_debug |= SLAB_TRACE;
1042 slub_debug |= SLAB_FAILSLAB;
1045 printk(KERN_ERR "slub_debug option '%c' "
1046 "unknown. skipped\n", *str);
1052 slub_debug_slabs = str + 1;
1057 __setup("slub_debug", setup_slub_debug);
1059 static unsigned long kmem_cache_flags(unsigned long objsize,
1060 unsigned long flags, const char *name,
1061 void (*ctor)(void *))
1064 * Enable debugging if selected on the kernel commandline.
1066 if (slub_debug && (!slub_debug_slabs ||
1067 !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
1068 flags |= slub_debug;
1073 static inline void setup_object_debug(struct kmem_cache *s,
1074 struct page *page, void *object) {}
1076 static inline int alloc_debug_processing(struct kmem_cache *s,
1077 struct page *page, void *object, unsigned long addr) { return 0; }
1079 static inline int free_debug_processing(struct kmem_cache *s,
1080 struct page *page, void *object, unsigned long addr) { return 0; }
1082 static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
1084 static inline int check_object(struct kmem_cache *s, struct page *page,
1085 void *object, u8 val) { return 1; }
1086 static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
1087 static inline unsigned long kmem_cache_flags(unsigned long objsize,
1088 unsigned long flags, const char *name,
1089 void (*ctor)(void *))
1093 #define slub_debug 0
1095 #define disable_higher_order_debug 0
1097 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
1099 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
1101 static inline void inc_slabs_node(struct kmem_cache *s, int node,
1103 static inline void dec_slabs_node(struct kmem_cache *s, int node,
1106 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
1109 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
1112 static inline void slab_free_hook(struct kmem_cache *s, void *x) {}
1114 #endif /* CONFIG_SLUB_DEBUG */
1117 * Slab allocation and freeing
1119 static inline struct page *alloc_slab_page(gfp_t flags, int node,
1120 struct kmem_cache_order_objects oo)
1122 int order = oo_order(oo);
1124 flags |= __GFP_NOTRACK;
1126 if (node == NUMA_NO_NODE)
1127 return alloc_pages(flags, order);
1129 return alloc_pages_exact_node(node, flags, order);
1132 static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1135 struct kmem_cache_order_objects oo = s->oo;
1138 flags |= s->allocflags;
1141 * Let the initial higher-order allocation fail under memory pressure
1142 * so we fall-back to the minimum order allocation.
1144 alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
1146 page = alloc_slab_page(alloc_gfp, node, oo);
1147 if (unlikely(!page)) {
1150 * Allocation may have failed due to fragmentation.
1151 * Try a lower order alloc if possible
1153 page = alloc_slab_page(flags, node, oo);
1157 stat(s, ORDER_FALLBACK);
1160 if (kmemcheck_enabled
1161 && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
1162 int pages = 1 << oo_order(oo);
1164 kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
1167 * Objects from caches that have a constructor don't get
1168 * cleared when they're allocated, so we need to do it here.
1171 kmemcheck_mark_uninitialized_pages(page, pages);
1173 kmemcheck_mark_unallocated_pages(page, pages);
1176 page->objects = oo_objects(oo);
1177 mod_zone_page_state(page_zone(page),
1178 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1179 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1185 static void setup_object(struct kmem_cache *s, struct page *page,
1188 setup_object_debug(s, page, object);
1189 if (unlikely(s->ctor))
1193 static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1200 BUG_ON(flags & GFP_SLAB_BUG_MASK);
1202 page = allocate_slab(s,
1203 flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
1207 inc_slabs_node(s, page_to_nid(page), page->objects);
1209 page->flags |= 1 << PG_slab;
1211 start = page_address(page);
1213 if (unlikely(s->flags & SLAB_POISON))
1214 memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
1217 for_each_object(p, s, start, page->objects) {
1218 setup_object(s, page, last);
1219 set_freepointer(s, last, p);
1222 setup_object(s, page, last);
1223 set_freepointer(s, last, NULL);
1225 page->freelist = start;
1231 static void __free_slab(struct kmem_cache *s, struct page *page)
1233 int order = compound_order(page);
1234 int pages = 1 << order;
1236 if (kmem_cache_debug(s)) {
1239 slab_pad_check(s, page);
1240 for_each_object(p, s, page_address(page),
1242 check_object(s, page, p, SLUB_RED_INACTIVE);
1245 kmemcheck_free_shadow(page, compound_order(page));
1247 mod_zone_page_state(page_zone(page),
1248 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1249 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1252 __ClearPageSlab(page);
1253 reset_page_mapcount(page);
1254 if (current->reclaim_state)
1255 current->reclaim_state->reclaimed_slab += pages;
1256 __free_pages(page, order);
1259 static void rcu_free_slab(struct rcu_head *h)
1263 page = container_of((struct list_head *)h, struct page, lru);
1264 __free_slab(page->slab, page);
1267 static void free_slab(struct kmem_cache *s, struct page *page)
1269 if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
1271 * RCU free overloads the RCU head over the LRU
1273 struct rcu_head *head = (void *)&page->lru;
1275 call_rcu(head, rcu_free_slab);
1277 __free_slab(s, page);
1280 static void discard_slab(struct kmem_cache *s, struct page *page)
1282 dec_slabs_node(s, page_to_nid(page), page->objects);
1287 * Per slab locking using the pagelock
1289 static __always_inline void slab_lock(struct page *page)
1291 bit_spin_lock(PG_locked, &page->flags);
1294 static __always_inline void slab_unlock(struct page *page)
1296 __bit_spin_unlock(PG_locked, &page->flags);
1299 static __always_inline int slab_trylock(struct page *page)
1303 rc = bit_spin_trylock(PG_locked, &page->flags);
1308 * Management of partially allocated slabs
1310 static void add_partial(struct kmem_cache_node *n,
1311 struct page *page, int tail)
1313 spin_lock(&n->list_lock);
1316 list_add_tail(&page->lru, &n->partial);
1318 list_add(&page->lru, &n->partial);
1319 spin_unlock(&n->list_lock);
1322 static inline void __remove_partial(struct kmem_cache_node *n,
1325 list_del(&page->lru);
1329 static void remove_partial(struct kmem_cache *s, struct page *page)
1331 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1333 spin_lock(&n->list_lock);
1334 __remove_partial(n, page);
1335 spin_unlock(&n->list_lock);
1339 * Lock slab and remove from the partial list.
1341 * Must hold list_lock.
1343 static inline int lock_and_freeze_slab(struct kmem_cache_node *n,
1346 if (slab_trylock(page)) {
1347 __remove_partial(n, page);
1348 __SetPageSlubFrozen(page);
1355 * Try to allocate a partial slab from a specific node.
1357 static struct page *get_partial_node(struct kmem_cache_node *n)
1362 * Racy check. If we mistakenly see no partial slabs then we
1363 * just allocate an empty slab. If we mistakenly try to get a
1364 * partial slab and there is none available then get_partials()
1367 if (!n || !n->nr_partial)
1370 spin_lock(&n->list_lock);
1371 list_for_each_entry(page, &n->partial, lru)
1372 if (lock_and_freeze_slab(n, page))
1376 spin_unlock(&n->list_lock);
1381 * Get a page from somewhere. Search in increasing NUMA distances.
1383 static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
1386 struct zonelist *zonelist;
1389 enum zone_type high_zoneidx = gfp_zone(flags);
1393 * The defrag ratio allows a configuration of the tradeoffs between
1394 * inter node defragmentation and node local allocations. A lower
1395 * defrag_ratio increases the tendency to do local allocations
1396 * instead of attempting to obtain partial slabs from other nodes.
1398 * If the defrag_ratio is set to 0 then kmalloc() always
1399 * returns node local objects. If the ratio is higher then kmalloc()
1400 * may return off node objects because partial slabs are obtained
1401 * from other nodes and filled up.
1403 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1404 * defrag_ratio = 1000) then every (well almost) allocation will
1405 * first attempt to defrag slab caches on other nodes. This means
1406 * scanning over all nodes to look for partial slabs which may be
1407 * expensive if we do it every time we are trying to find a slab
1408 * with available objects.
1410 if (!s->remote_node_defrag_ratio ||
1411 get_cycles() % 1024 > s->remote_node_defrag_ratio)
1415 zonelist = node_zonelist(slab_node(current->mempolicy), flags);
1416 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
1417 struct kmem_cache_node *n;
1419 n = get_node(s, zone_to_nid(zone));
1421 if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
1422 n->nr_partial > s->min_partial) {
1423 page = get_partial_node(n);
1436 * Get a partial page, lock it and return it.
1438 static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
1441 int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
1443 page = get_partial_node(get_node(s, searchnode));
1444 if (page || node != -1)
1447 return get_any_partial(s, flags);
1451 * Move a page back to the lists.
1453 * Must be called with the slab lock held.
1455 * On exit the slab lock will have been dropped.
1457 static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
1460 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1462 __ClearPageSlubFrozen(page);
1465 if (page->freelist) {
1466 add_partial(n, page, tail);
1467 stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
1469 stat(s, DEACTIVATE_FULL);
1470 if (kmem_cache_debug(s) && (s->flags & SLAB_STORE_USER))
1475 stat(s, DEACTIVATE_EMPTY);
1476 if (n->nr_partial < s->min_partial) {
1478 * Adding an empty slab to the partial slabs in order
1479 * to avoid page allocator overhead. This slab needs
1480 * to come after the other slabs with objects in
1481 * so that the others get filled first. That way the
1482 * size of the partial list stays small.
1484 * kmem_cache_shrink can reclaim any empty slabs from
1487 add_partial(n, page, 1);
1492 discard_slab(s, page);
1497 #ifdef CONFIG_CMPXCHG_LOCAL
1498 #ifdef CONFIG_PREEMPT
1500 * Calculate the next globally unique transaction for disambiguiation
1501 * during cmpxchg. The transactions start with the cpu number and are then
1502 * incremented by CONFIG_NR_CPUS.
1504 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1507 * No preemption supported therefore also no need to check for
1513 static inline unsigned long next_tid(unsigned long tid)
1515 return tid + TID_STEP;
1518 static inline unsigned int tid_to_cpu(unsigned long tid)
1520 return tid % TID_STEP;
1523 static inline unsigned long tid_to_event(unsigned long tid)
1525 return tid / TID_STEP;
1528 static inline unsigned int init_tid(int cpu)
1533 static inline void note_cmpxchg_failure(const char *n,
1534 const struct kmem_cache *s, unsigned long tid)
1536 #ifdef SLUB_DEBUG_CMPXCHG
1537 unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
1539 printk(KERN_INFO "%s %s: cmpxchg redo ", n, s->name);
1541 #ifdef CONFIG_PREEMPT
1542 if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
1543 printk("due to cpu change %d -> %d\n",
1544 tid_to_cpu(tid), tid_to_cpu(actual_tid));
1547 if (tid_to_event(tid) != tid_to_event(actual_tid))
1548 printk("due to cpu running other code. Event %ld->%ld\n",
1549 tid_to_event(tid), tid_to_event(actual_tid));
1551 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1552 actual_tid, tid, next_tid(tid));
1558 void init_kmem_cache_cpus(struct kmem_cache *s)
1560 #if defined(CONFIG_CMPXCHG_LOCAL) && defined(CONFIG_PREEMPT)
1563 for_each_possible_cpu(cpu)
1564 per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
1569 * Remove the cpu slab
1571 static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
1574 struct page *page = c->page;
1578 stat(s, DEACTIVATE_REMOTE_FREES);
1580 * Merge cpu freelist into slab freelist. Typically we get here
1581 * because both freelists are empty. So this is unlikely
1584 while (unlikely(c->freelist)) {
1587 tail = 0; /* Hot objects. Put the slab first */
1589 /* Retrieve object from cpu_freelist */
1590 object = c->freelist;
1591 c->freelist = get_freepointer(s, c->freelist);
1593 /* And put onto the regular freelist */
1594 set_freepointer(s, object, page->freelist);
1595 page->freelist = object;
1599 #ifdef CONFIG_CMPXCHG_LOCAL
1600 c->tid = next_tid(c->tid);
1602 unfreeze_slab(s, page, tail);
1605 static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
1607 stat(s, CPUSLAB_FLUSH);
1609 deactivate_slab(s, c);
1615 * Called from IPI handler with interrupts disabled.
1617 static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
1619 struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
1621 if (likely(c && c->page))
1625 static void flush_cpu_slab(void *d)
1627 struct kmem_cache *s = d;
1629 __flush_cpu_slab(s, smp_processor_id());
1632 static void flush_all(struct kmem_cache *s)
1634 on_each_cpu(flush_cpu_slab, s, 1);
1638 * Check if the objects in a per cpu structure fit numa
1639 * locality expectations.
1641 static inline int node_match(struct kmem_cache_cpu *c, int node)
1644 if (node != NUMA_NO_NODE && c->node != node)
1650 static int count_free(struct page *page)
1652 return page->objects - page->inuse;
1655 static unsigned long count_partial(struct kmem_cache_node *n,
1656 int (*get_count)(struct page *))
1658 unsigned long flags;
1659 unsigned long x = 0;
1662 spin_lock_irqsave(&n->list_lock, flags);
1663 list_for_each_entry(page, &n->partial, lru)
1664 x += get_count(page);
1665 spin_unlock_irqrestore(&n->list_lock, flags);
1669 static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
1671 #ifdef CONFIG_SLUB_DEBUG
1672 return atomic_long_read(&n->total_objects);
1678 static noinline void
1679 slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
1684 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
1686 printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, "
1687 "default order: %d, min order: %d\n", s->name, s->objsize,
1688 s->size, oo_order(s->oo), oo_order(s->min));
1690 if (oo_order(s->min) > get_order(s->objsize))
1691 printk(KERN_WARNING " %s debugging increased min order, use "
1692 "slub_debug=O to disable.\n", s->name);
1694 for_each_online_node(node) {
1695 struct kmem_cache_node *n = get_node(s, node);
1696 unsigned long nr_slabs;
1697 unsigned long nr_objs;
1698 unsigned long nr_free;
1703 nr_free = count_partial(n, count_free);
1704 nr_slabs = node_nr_slabs(n);
1705 nr_objs = node_nr_objs(n);
1708 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
1709 node, nr_slabs, nr_objs, nr_free);
1714 * Slow path. The lockless freelist is empty or we need to perform
1717 * Interrupts are disabled.
1719 * Processing is still very fast if new objects have been freed to the
1720 * regular freelist. In that case we simply take over the regular freelist
1721 * as the lockless freelist and zap the regular freelist.
1723 * If that is not working then we fall back to the partial lists. We take the
1724 * first element of the freelist as the object to allocate now and move the
1725 * rest of the freelist to the lockless freelist.
1727 * And if we were unable to get a new slab from the partial slab lists then
1728 * we need to allocate a new slab. This is the slowest path since it involves
1729 * a call to the page allocator and the setup of a new slab.
1731 static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
1732 unsigned long addr, struct kmem_cache_cpu *c)
1736 #ifdef CONFIG_CMPXCHG_LOCAL
1737 unsigned long flags;
1739 local_irq_save(flags);
1740 #ifdef CONFIG_PREEMPT
1742 * We may have been preempted and rescheduled on a different
1743 * cpu before disabling interrupts. Need to reload cpu area
1746 c = this_cpu_ptr(s->cpu_slab);
1750 /* We handle __GFP_ZERO in the caller */
1751 gfpflags &= ~__GFP_ZERO;
1757 if (unlikely(!node_match(c, node)))
1760 stat(s, ALLOC_REFILL);
1763 object = c->page->freelist;
1764 if (unlikely(!object))
1766 if (kmem_cache_debug(s))
1769 c->freelist = get_freepointer(s, object);
1770 c->page->inuse = c->page->objects;
1771 c->page->freelist = NULL;
1772 c->node = page_to_nid(c->page);
1774 slab_unlock(c->page);
1775 #ifdef CONFIG_CMPXCHG_LOCAL
1776 c->tid = next_tid(c->tid);
1777 local_irq_restore(flags);
1779 stat(s, ALLOC_SLOWPATH);
1783 deactivate_slab(s, c);
1786 new = get_partial(s, gfpflags, node);
1789 stat(s, ALLOC_FROM_PARTIAL);
1793 gfpflags &= gfp_allowed_mask;
1794 if (gfpflags & __GFP_WAIT)
1797 new = new_slab(s, gfpflags, node);
1799 if (gfpflags & __GFP_WAIT)
1800 local_irq_disable();
1803 c = __this_cpu_ptr(s->cpu_slab);
1804 stat(s, ALLOC_SLAB);
1808 __SetPageSlubFrozen(new);
1812 if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
1813 slab_out_of_memory(s, gfpflags, node);
1816 if (!alloc_debug_processing(s, c->page, object, addr))
1820 c->page->freelist = get_freepointer(s, object);
1821 c->node = NUMA_NO_NODE;
1826 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1827 * have the fastpath folded into their functions. So no function call
1828 * overhead for requests that can be satisfied on the fastpath.
1830 * The fastpath works by first checking if the lockless freelist can be used.
1831 * If not then __slab_alloc is called for slow processing.
1833 * Otherwise we can simply pick the next object from the lockless free list.
1835 static __always_inline void *slab_alloc(struct kmem_cache *s,
1836 gfp_t gfpflags, int node, unsigned long addr)
1839 struct kmem_cache_cpu *c;
1840 #ifdef CONFIG_CMPXCHG_LOCAL
1843 unsigned long flags;
1846 if (slab_pre_alloc_hook(s, gfpflags))
1849 #ifndef CONFIG_CMPXCHG_LOCAL
1850 local_irq_save(flags);
1856 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
1857 * enabled. We may switch back and forth between cpus while
1858 * reading from one cpu area. That does not matter as long
1859 * as we end up on the original cpu again when doing the cmpxchg.
1861 c = __this_cpu_ptr(s->cpu_slab);
1863 #ifdef CONFIG_CMPXCHG_LOCAL
1865 * The transaction ids are globally unique per cpu and per operation on
1866 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
1867 * occurs on the right processor and that there was no operation on the
1868 * linked list in between.
1874 object = c->freelist;
1875 if (unlikely(!object || !node_match(c, node)))
1877 object = __slab_alloc(s, gfpflags, node, addr, c);
1880 #ifdef CONFIG_CMPXCHG_LOCAL
1882 * The cmpxchg will only match if there was no additonal
1883 * operation and if we are on the right processor.
1885 * The cmpxchg does the following atomically (without lock semantics!)
1886 * 1. Relocate first pointer to the current per cpu area.
1887 * 2. Verify that tid and freelist have not been changed
1888 * 3. If they were not changed replace tid and freelist
1890 * Since this is without lock semantics the protection is only against
1891 * code executing on this cpu *not* from access by other cpus.
1893 if (unlikely(!this_cpu_cmpxchg_double(
1894 s->cpu_slab->freelist, s->cpu_slab->tid,
1896 get_freepointer(s, object), next_tid(tid)))) {
1898 note_cmpxchg_failure("slab_alloc", s, tid);
1902 c->freelist = get_freepointer(s, object);
1904 stat(s, ALLOC_FASTPATH);
1907 #ifndef CONFIG_CMPXCHG_LOCAL
1908 local_irq_restore(flags);
1911 if (unlikely(gfpflags & __GFP_ZERO) && object)
1912 memset(object, 0, s->objsize);
1914 slab_post_alloc_hook(s, gfpflags, object);
1919 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
1921 void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
1923 trace_kmem_cache_alloc(_RET_IP_, ret, s->objsize, s->size, gfpflags);
1927 EXPORT_SYMBOL(kmem_cache_alloc);
1929 #ifdef CONFIG_TRACING
1930 void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
1932 void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
1933 trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
1936 EXPORT_SYMBOL(kmem_cache_alloc_trace);
1938 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
1940 void *ret = kmalloc_order(size, flags, order);
1941 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
1944 EXPORT_SYMBOL(kmalloc_order_trace);
1948 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
1950 void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
1952 trace_kmem_cache_alloc_node(_RET_IP_, ret,
1953 s->objsize, s->size, gfpflags, node);
1957 EXPORT_SYMBOL(kmem_cache_alloc_node);
1959 #ifdef CONFIG_TRACING
1960 void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
1962 int node, size_t size)
1964 void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
1966 trace_kmalloc_node(_RET_IP_, ret,
1967 size, s->size, gfpflags, node);
1970 EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
1975 * Slow patch handling. This may still be called frequently since objects
1976 * have a longer lifetime than the cpu slabs in most processing loads.
1978 * So we still attempt to reduce cache line usage. Just take the slab
1979 * lock and free the item. If there is no additional partial page
1980 * handling required then we can return immediately.
1982 static void __slab_free(struct kmem_cache *s, struct page *page,
1983 void *x, unsigned long addr)
1986 void **object = (void *)x;
1987 #ifdef CONFIG_CMPXCHG_LOCAL
1988 unsigned long flags;
1990 local_irq_save(flags);
1993 stat(s, FREE_SLOWPATH);
1995 if (kmem_cache_debug(s))
1999 prior = page->freelist;
2000 set_freepointer(s, object, prior);
2001 page->freelist = object;
2004 if (unlikely(PageSlubFrozen(page))) {
2005 stat(s, FREE_FROZEN);
2009 if (unlikely(!page->inuse))
2013 * Objects left in the slab. If it was not on the partial list before
2016 if (unlikely(!prior)) {
2017 add_partial(get_node(s, page_to_nid(page)), page, 1);
2018 stat(s, FREE_ADD_PARTIAL);
2023 #ifdef CONFIG_CMPXCHG_LOCAL
2024 local_irq_restore(flags);
2031 * Slab still on the partial list.
2033 remove_partial(s, page);
2034 stat(s, FREE_REMOVE_PARTIAL);
2037 #ifdef CONFIG_CMPXCHG_LOCAL
2038 local_irq_restore(flags);
2041 discard_slab(s, page);
2045 if (!free_debug_processing(s, page, x, addr))
2051 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2052 * can perform fastpath freeing without additional function calls.
2054 * The fastpath is only possible if we are freeing to the current cpu slab
2055 * of this processor. This typically the case if we have just allocated
2058 * If fastpath is not possible then fall back to __slab_free where we deal
2059 * with all sorts of special processing.
2061 static __always_inline void slab_free(struct kmem_cache *s,
2062 struct page *page, void *x, unsigned long addr)
2064 void **object = (void *)x;
2065 struct kmem_cache_cpu *c;
2066 #ifdef CONFIG_CMPXCHG_LOCAL
2069 unsigned long flags;
2072 slab_free_hook(s, x);
2074 #ifndef CONFIG_CMPXCHG_LOCAL
2075 local_irq_save(flags);
2080 * Determine the currently cpus per cpu slab.
2081 * The cpu may change afterward. However that does not matter since
2082 * data is retrieved via this pointer. If we are on the same cpu
2083 * during the cmpxchg then the free will succedd.
2085 c = __this_cpu_ptr(s->cpu_slab);
2087 #ifdef CONFIG_CMPXCHG_LOCAL
2092 if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
2093 set_freepointer(s, object, c->freelist);
2095 #ifdef CONFIG_CMPXCHG_LOCAL
2096 if (unlikely(!this_cpu_cmpxchg_double(
2097 s->cpu_slab->freelist, s->cpu_slab->tid,
2099 object, next_tid(tid)))) {
2101 note_cmpxchg_failure("slab_free", s, tid);
2105 c->freelist = object;
2107 stat(s, FREE_FASTPATH);
2109 __slab_free(s, page, x, addr);
2111 #ifndef CONFIG_CMPXCHG_LOCAL
2112 local_irq_restore(flags);
2116 void kmem_cache_free(struct kmem_cache *s, void *x)
2120 page = virt_to_head_page(x);
2122 slab_free(s, page, x, _RET_IP_);
2124 trace_kmem_cache_free(_RET_IP_, x);
2126 EXPORT_SYMBOL(kmem_cache_free);
2129 * Object placement in a slab is made very easy because we always start at
2130 * offset 0. If we tune the size of the object to the alignment then we can
2131 * get the required alignment by putting one properly sized object after
2134 * Notice that the allocation order determines the sizes of the per cpu
2135 * caches. Each processor has always one slab available for allocations.
2136 * Increasing the allocation order reduces the number of times that slabs
2137 * must be moved on and off the partial lists and is therefore a factor in
2142 * Mininum / Maximum order of slab pages. This influences locking overhead
2143 * and slab fragmentation. A higher order reduces the number of partial slabs
2144 * and increases the number of allocations possible without having to
2145 * take the list_lock.
2147 static int slub_min_order;
2148 static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
2149 static int slub_min_objects;
2152 * Merge control. If this is set then no merging of slab caches will occur.
2153 * (Could be removed. This was introduced to pacify the merge skeptics.)
2155 static int slub_nomerge;
2158 * Calculate the order of allocation given an slab object size.
2160 * The order of allocation has significant impact on performance and other
2161 * system components. Generally order 0 allocations should be preferred since
2162 * order 0 does not cause fragmentation in the page allocator. Larger objects
2163 * be problematic to put into order 0 slabs because there may be too much
2164 * unused space left. We go to a higher order if more than 1/16th of the slab
2167 * In order to reach satisfactory performance we must ensure that a minimum
2168 * number of objects is in one slab. Otherwise we may generate too much
2169 * activity on the partial lists which requires taking the list_lock. This is
2170 * less a concern for large slabs though which are rarely used.
2172 * slub_max_order specifies the order where we begin to stop considering the
2173 * number of objects in a slab as critical. If we reach slub_max_order then
2174 * we try to keep the page order as low as possible. So we accept more waste
2175 * of space in favor of a small page order.
2177 * Higher order allocations also allow the placement of more objects in a
2178 * slab and thereby reduce object handling overhead. If the user has
2179 * requested a higher mininum order then we start with that one instead of
2180 * the smallest order which will fit the object.
2182 static inline int slab_order(int size, int min_objects,
2183 int max_order, int fract_leftover)
2187 int min_order = slub_min_order;
2189 if ((PAGE_SIZE << min_order) / size > MAX_OBJS_PER_PAGE)
2190 return get_order(size * MAX_OBJS_PER_PAGE) - 1;
2192 for (order = max(min_order,
2193 fls(min_objects * size - 1) - PAGE_SHIFT);
2194 order <= max_order; order++) {
2196 unsigned long slab_size = PAGE_SIZE << order;
2198 if (slab_size < min_objects * size)
2201 rem = slab_size % size;
2203 if (rem <= slab_size / fract_leftover)
2211 static inline int calculate_order(int size)
2219 * Attempt to find best configuration for a slab. This
2220 * works by first attempting to generate a layout with
2221 * the best configuration and backing off gradually.
2223 * First we reduce the acceptable waste in a slab. Then
2224 * we reduce the minimum objects required in a slab.
2226 min_objects = slub_min_objects;
2228 min_objects = 4 * (fls(nr_cpu_ids) + 1);
2229 max_objects = (PAGE_SIZE << slub_max_order)/size;
2230 min_objects = min(min_objects, max_objects);
2232 while (min_objects > 1) {
2234 while (fraction >= 4) {
2235 order = slab_order(size, min_objects,
2236 slub_max_order, fraction);
2237 if (order <= slub_max_order)
2245 * We were unable to place multiple objects in a slab. Now
2246 * lets see if we can place a single object there.
2248 order = slab_order(size, 1, slub_max_order, 1);
2249 if (order <= slub_max_order)
2253 * Doh this slab cannot be placed using slub_max_order.
2255 order = slab_order(size, 1, MAX_ORDER, 1);
2256 if (order < MAX_ORDER)
2262 * Figure out what the alignment of the objects will be.
2264 static unsigned long calculate_alignment(unsigned long flags,
2265 unsigned long align, unsigned long size)
2268 * If the user wants hardware cache aligned objects then follow that
2269 * suggestion if the object is sufficiently large.
2271 * The hardware cache alignment cannot override the specified
2272 * alignment though. If that is greater then use it.
2274 if (flags & SLAB_HWCACHE_ALIGN) {
2275 unsigned long ralign = cache_line_size();
2276 while (size <= ralign / 2)
2278 align = max(align, ralign);
2281 if (align < ARCH_SLAB_MINALIGN)
2282 align = ARCH_SLAB_MINALIGN;
2284 return ALIGN(align, sizeof(void *));
2288 init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
2291 spin_lock_init(&n->list_lock);
2292 INIT_LIST_HEAD(&n->partial);
2293 #ifdef CONFIG_SLUB_DEBUG
2294 atomic_long_set(&n->nr_slabs, 0);
2295 atomic_long_set(&n->total_objects, 0);
2296 INIT_LIST_HEAD(&n->full);
2300 static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
2302 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
2303 SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
2305 #ifdef CONFIG_CMPXCHG_LOCAL
2307 * Must align to double word boundary for the double cmpxchg instructions
2310 s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu), 2 * sizeof(void *));
2312 /* Regular alignment is sufficient */
2313 s->cpu_slab = alloc_percpu(struct kmem_cache_cpu);
2319 init_kmem_cache_cpus(s);
2324 static struct kmem_cache *kmem_cache_node;
2327 * No kmalloc_node yet so do it by hand. We know that this is the first
2328 * slab on the node for this slabcache. There are no concurrent accesses
2331 * Note that this function only works on the kmalloc_node_cache
2332 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2333 * memory on a fresh node that has no slab structures yet.
2335 static void early_kmem_cache_node_alloc(int node)
2338 struct kmem_cache_node *n;
2339 unsigned long flags;
2341 BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
2343 page = new_slab(kmem_cache_node, GFP_NOWAIT, node);
2346 if (page_to_nid(page) != node) {
2347 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2349 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2350 "in order to be able to continue\n");
2355 page->freelist = get_freepointer(kmem_cache_node, n);
2357 kmem_cache_node->node[node] = n;
2358 #ifdef CONFIG_SLUB_DEBUG
2359 init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
2360 init_tracking(kmem_cache_node, n);
2362 init_kmem_cache_node(n, kmem_cache_node);
2363 inc_slabs_node(kmem_cache_node, node, page->objects);
2366 * lockdep requires consistent irq usage for each lock
2367 * so even though there cannot be a race this early in
2368 * the boot sequence, we still disable irqs.
2370 local_irq_save(flags);
2371 add_partial(n, page, 0);
2372 local_irq_restore(flags);
2375 static void free_kmem_cache_nodes(struct kmem_cache *s)
2379 for_each_node_state(node, N_NORMAL_MEMORY) {
2380 struct kmem_cache_node *n = s->node[node];
2383 kmem_cache_free(kmem_cache_node, n);
2385 s->node[node] = NULL;
2389 static int init_kmem_cache_nodes(struct kmem_cache *s)
2393 for_each_node_state(node, N_NORMAL_MEMORY) {
2394 struct kmem_cache_node *n;
2396 if (slab_state == DOWN) {
2397 early_kmem_cache_node_alloc(node);
2400 n = kmem_cache_alloc_node(kmem_cache_node,
2404 free_kmem_cache_nodes(s);
2409 init_kmem_cache_node(n, s);
2414 static void set_min_partial(struct kmem_cache *s, unsigned long min)
2416 if (min < MIN_PARTIAL)
2418 else if (min > MAX_PARTIAL)
2420 s->min_partial = min;
2424 * calculate_sizes() determines the order and the distribution of data within
2427 static int calculate_sizes(struct kmem_cache *s, int forced_order)
2429 unsigned long flags = s->flags;
2430 unsigned long size = s->objsize;
2431 unsigned long align = s->align;
2435 * Round up object size to the next word boundary. We can only
2436 * place the free pointer at word boundaries and this determines
2437 * the possible location of the free pointer.
2439 size = ALIGN(size, sizeof(void *));
2441 #ifdef CONFIG_SLUB_DEBUG
2443 * Determine if we can poison the object itself. If the user of
2444 * the slab may touch the object after free or before allocation
2445 * then we should never poison the object itself.
2447 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
2449 s->flags |= __OBJECT_POISON;
2451 s->flags &= ~__OBJECT_POISON;
2455 * If we are Redzoning then check if there is some space between the
2456 * end of the object and the free pointer. If not then add an
2457 * additional word to have some bytes to store Redzone information.
2459 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2460 size += sizeof(void *);
2464 * With that we have determined the number of bytes in actual use
2465 * by the object. This is the potential offset to the free pointer.
2469 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
2472 * Relocate free pointer after the object if it is not
2473 * permitted to overwrite the first word of the object on
2476 * This is the case if we do RCU, have a constructor or
2477 * destructor or are poisoning the objects.
2480 size += sizeof(void *);
2483 #ifdef CONFIG_SLUB_DEBUG
2484 if (flags & SLAB_STORE_USER)
2486 * Need to store information about allocs and frees after
2489 size += 2 * sizeof(struct track);
2491 if (flags & SLAB_RED_ZONE)
2493 * Add some empty padding so that we can catch
2494 * overwrites from earlier objects rather than let
2495 * tracking information or the free pointer be
2496 * corrupted if a user writes before the start
2499 size += sizeof(void *);
2503 * Determine the alignment based on various parameters that the
2504 * user specified and the dynamic determination of cache line size
2507 align = calculate_alignment(flags, align, s->objsize);
2511 * SLUB stores one object immediately after another beginning from
2512 * offset 0. In order to align the objects we have to simply size
2513 * each object to conform to the alignment.
2515 size = ALIGN(size, align);
2517 if (forced_order >= 0)
2518 order = forced_order;
2520 order = calculate_order(size);
2527 s->allocflags |= __GFP_COMP;
2529 if (s->flags & SLAB_CACHE_DMA)
2530 s->allocflags |= SLUB_DMA;
2532 if (s->flags & SLAB_RECLAIM_ACCOUNT)
2533 s->allocflags |= __GFP_RECLAIMABLE;
2536 * Determine the number of objects per slab
2538 s->oo = oo_make(order, size);
2539 s->min = oo_make(get_order(size), size);
2540 if (oo_objects(s->oo) > oo_objects(s->max))
2543 return !!oo_objects(s->oo);
2547 static int kmem_cache_open(struct kmem_cache *s,
2548 const char *name, size_t size,
2549 size_t align, unsigned long flags,
2550 void (*ctor)(void *))
2552 memset(s, 0, kmem_size);
2557 s->flags = kmem_cache_flags(size, flags, name, ctor);
2559 if (!calculate_sizes(s, -1))
2561 if (disable_higher_order_debug) {
2563 * Disable debugging flags that store metadata if the min slab
2566 if (get_order(s->size) > get_order(s->objsize)) {
2567 s->flags &= ~DEBUG_METADATA_FLAGS;
2569 if (!calculate_sizes(s, -1))
2575 * The larger the object size is, the more pages we want on the partial
2576 * list to avoid pounding the page allocator excessively.
2578 set_min_partial(s, ilog2(s->size));
2581 s->remote_node_defrag_ratio = 1000;
2583 if (!init_kmem_cache_nodes(s))
2586 if (alloc_kmem_cache_cpus(s))
2589 free_kmem_cache_nodes(s);
2591 if (flags & SLAB_PANIC)
2592 panic("Cannot create slab %s size=%lu realsize=%u "
2593 "order=%u offset=%u flags=%lx\n",
2594 s->name, (unsigned long)size, s->size, oo_order(s->oo),
2600 * Determine the size of a slab object
2602 unsigned int kmem_cache_size(struct kmem_cache *s)
2606 EXPORT_SYMBOL(kmem_cache_size);
2608 const char *kmem_cache_name(struct kmem_cache *s)
2612 EXPORT_SYMBOL(kmem_cache_name);
2614 static void list_slab_objects(struct kmem_cache *s, struct page *page,
2617 #ifdef CONFIG_SLUB_DEBUG
2618 void *addr = page_address(page);
2620 unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) *
2621 sizeof(long), GFP_ATOMIC);
2624 slab_err(s, page, "%s", text);
2626 for_each_free_object(p, s, page->freelist)
2627 set_bit(slab_index(p, s, addr), map);
2629 for_each_object(p, s, addr, page->objects) {
2631 if (!test_bit(slab_index(p, s, addr), map)) {
2632 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
2634 print_tracking(s, p);
2643 * Attempt to free all partial slabs on a node.
2645 static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
2647 unsigned long flags;
2648 struct page *page, *h;
2650 spin_lock_irqsave(&n->list_lock, flags);
2651 list_for_each_entry_safe(page, h, &n->partial, lru) {
2653 __remove_partial(n, page);
2654 discard_slab(s, page);
2656 list_slab_objects(s, page,
2657 "Objects remaining on kmem_cache_close()");
2660 spin_unlock_irqrestore(&n->list_lock, flags);
2664 * Release all resources used by a slab cache.
2666 static inline int kmem_cache_close(struct kmem_cache *s)
2671 free_percpu(s->cpu_slab);
2672 /* Attempt to free all objects */
2673 for_each_node_state(node, N_NORMAL_MEMORY) {
2674 struct kmem_cache_node *n = get_node(s, node);
2677 if (n->nr_partial || slabs_node(s, node))
2680 free_kmem_cache_nodes(s);
2685 * Close a cache and release the kmem_cache structure
2686 * (must be used for caches created using kmem_cache_create)
2688 void kmem_cache_destroy(struct kmem_cache *s)
2690 down_write(&slub_lock);
2694 if (kmem_cache_close(s)) {
2695 printk(KERN_ERR "SLUB %s: %s called for cache that "
2696 "still has objects.\n", s->name, __func__);
2699 if (s->flags & SLAB_DESTROY_BY_RCU)
2701 sysfs_slab_remove(s);
2703 up_write(&slub_lock);
2705 EXPORT_SYMBOL(kmem_cache_destroy);
2707 /********************************************************************
2709 *******************************************************************/
2711 struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
2712 EXPORT_SYMBOL(kmalloc_caches);
2714 static struct kmem_cache *kmem_cache;
2716 #ifdef CONFIG_ZONE_DMA
2717 static struct kmem_cache *kmalloc_dma_caches[SLUB_PAGE_SHIFT];
2720 static int __init setup_slub_min_order(char *str)
2722 get_option(&str, &slub_min_order);
2727 __setup("slub_min_order=", setup_slub_min_order);
2729 static int __init setup_slub_max_order(char *str)
2731 get_option(&str, &slub_max_order);
2732 slub_max_order = min(slub_max_order, MAX_ORDER - 1);
2737 __setup("slub_max_order=", setup_slub_max_order);
2739 static int __init setup_slub_min_objects(char *str)
2741 get_option(&str, &slub_min_objects);
2746 __setup("slub_min_objects=", setup_slub_min_objects);
2748 static int __init setup_slub_nomerge(char *str)
2754 __setup("slub_nomerge", setup_slub_nomerge);
2756 static struct kmem_cache *__init create_kmalloc_cache(const char *name,
2757 int size, unsigned int flags)
2759 struct kmem_cache *s;
2761 s = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
2764 * This function is called with IRQs disabled during early-boot on
2765 * single CPU so there's no need to take slub_lock here.
2767 if (!kmem_cache_open(s, name, size, ARCH_KMALLOC_MINALIGN,
2771 list_add(&s->list, &slab_caches);
2775 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2780 * Conversion table for small slabs sizes / 8 to the index in the
2781 * kmalloc array. This is necessary for slabs < 192 since we have non power
2782 * of two cache sizes there. The size of larger slabs can be determined using
2785 static s8 size_index[24] = {
2812 static inline int size_index_elem(size_t bytes)
2814 return (bytes - 1) / 8;
2817 static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2823 return ZERO_SIZE_PTR;
2825 index = size_index[size_index_elem(size)];
2827 index = fls(size - 1);
2829 #ifdef CONFIG_ZONE_DMA
2830 if (unlikely((flags & SLUB_DMA)))
2831 return kmalloc_dma_caches[index];
2834 return kmalloc_caches[index];
2837 void *__kmalloc(size_t size, gfp_t flags)
2839 struct kmem_cache *s;
2842 if (unlikely(size > SLUB_MAX_SIZE))
2843 return kmalloc_large(size, flags);
2845 s = get_slab(size, flags);
2847 if (unlikely(ZERO_OR_NULL_PTR(s)))
2850 ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_);
2852 trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
2856 EXPORT_SYMBOL(__kmalloc);
2859 static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
2864 flags |= __GFP_COMP | __GFP_NOTRACK;
2865 page = alloc_pages_node(node, flags, get_order(size));
2867 ptr = page_address(page);
2869 kmemleak_alloc(ptr, size, 1, flags);
2873 void *__kmalloc_node(size_t size, gfp_t flags, int node)
2875 struct kmem_cache *s;
2878 if (unlikely(size > SLUB_MAX_SIZE)) {
2879 ret = kmalloc_large_node(size, flags, node);
2881 trace_kmalloc_node(_RET_IP_, ret,
2882 size, PAGE_SIZE << get_order(size),
2888 s = get_slab(size, flags);
2890 if (unlikely(ZERO_OR_NULL_PTR(s)))
2893 ret = slab_alloc(s, flags, node, _RET_IP_);
2895 trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
2899 EXPORT_SYMBOL(__kmalloc_node);
2902 size_t ksize(const void *object)
2905 struct kmem_cache *s;
2907 if (unlikely(object == ZERO_SIZE_PTR))
2910 page = virt_to_head_page(object);
2912 if (unlikely(!PageSlab(page))) {
2913 WARN_ON(!PageCompound(page));
2914 return PAGE_SIZE << compound_order(page);
2918 #ifdef CONFIG_SLUB_DEBUG
2920 * Debugging requires use of the padding between object
2921 * and whatever may come after it.
2923 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
2928 * If we have the need to store the freelist pointer
2929 * back there or track user information then we can
2930 * only use the space before that information.
2932 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
2935 * Else we can use all the padding etc for the allocation
2939 EXPORT_SYMBOL(ksize);
2941 void kfree(const void *x)
2944 void *object = (void *)x;
2946 trace_kfree(_RET_IP_, x);
2948 if (unlikely(ZERO_OR_NULL_PTR(x)))
2951 page = virt_to_head_page(x);
2952 if (unlikely(!PageSlab(page))) {
2953 BUG_ON(!PageCompound(page));
2958 slab_free(page->slab, page, object, _RET_IP_);
2960 EXPORT_SYMBOL(kfree);
2963 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2964 * the remaining slabs by the number of items in use. The slabs with the
2965 * most items in use come first. New allocations will then fill those up
2966 * and thus they can be removed from the partial lists.
2968 * The slabs with the least items are placed last. This results in them
2969 * being allocated from last increasing the chance that the last objects
2970 * are freed in them.
2972 int kmem_cache_shrink(struct kmem_cache *s)
2976 struct kmem_cache_node *n;
2979 int objects = oo_objects(s->max);
2980 struct list_head *slabs_by_inuse =
2981 kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
2982 unsigned long flags;
2984 if (!slabs_by_inuse)
2988 for_each_node_state(node, N_NORMAL_MEMORY) {
2989 n = get_node(s, node);
2994 for (i = 0; i < objects; i++)
2995 INIT_LIST_HEAD(slabs_by_inuse + i);
2997 spin_lock_irqsave(&n->list_lock, flags);
3000 * Build lists indexed by the items in use in each slab.
3002 * Note that concurrent frees may occur while we hold the
3003 * list_lock. page->inuse here is the upper limit.
3005 list_for_each_entry_safe(page, t, &n->partial, lru) {
3006 if (!page->inuse && slab_trylock(page)) {
3008 * Must hold slab lock here because slab_free
3009 * may have freed the last object and be
3010 * waiting to release the slab.
3012 __remove_partial(n, page);
3014 discard_slab(s, page);
3016 list_move(&page->lru,
3017 slabs_by_inuse + page->inuse);
3022 * Rebuild the partial list with the slabs filled up most
3023 * first and the least used slabs at the end.
3025 for (i = objects - 1; i >= 0; i--)
3026 list_splice(slabs_by_inuse + i, n->partial.prev);
3028 spin_unlock_irqrestore(&n->list_lock, flags);
3031 kfree(slabs_by_inuse);
3034 EXPORT_SYMBOL(kmem_cache_shrink);
3036 #if defined(CONFIG_MEMORY_HOTPLUG)
3037 static int slab_mem_going_offline_callback(void *arg)
3039 struct kmem_cache *s;
3041 down_read(&slub_lock);
3042 list_for_each_entry(s, &slab_caches, list)
3043 kmem_cache_shrink(s);
3044 up_read(&slub_lock);
3049 static void slab_mem_offline_callback(void *arg)
3051 struct kmem_cache_node *n;
3052 struct kmem_cache *s;
3053 struct memory_notify *marg = arg;
3056 offline_node = marg->status_change_nid;
3059 * If the node still has available memory. we need kmem_cache_node
3062 if (offline_node < 0)
3065 down_read(&slub_lock);
3066 list_for_each_entry(s, &slab_caches, list) {
3067 n = get_node(s, offline_node);
3070 * if n->nr_slabs > 0, slabs still exist on the node
3071 * that is going down. We were unable to free them,
3072 * and offline_pages() function shouldn't call this
3073 * callback. So, we must fail.
3075 BUG_ON(slabs_node(s, offline_node));
3077 s->node[offline_node] = NULL;
3078 kmem_cache_free(kmem_cache_node, n);
3081 up_read(&slub_lock);
3084 static int slab_mem_going_online_callback(void *arg)
3086 struct kmem_cache_node *n;
3087 struct kmem_cache *s;
3088 struct memory_notify *marg = arg;
3089 int nid = marg->status_change_nid;
3093 * If the node's memory is already available, then kmem_cache_node is
3094 * already created. Nothing to do.
3100 * We are bringing a node online. No memory is available yet. We must
3101 * allocate a kmem_cache_node structure in order to bring the node
3104 down_read(&slub_lock);
3105 list_for_each_entry(s, &slab_caches, list) {
3107 * XXX: kmem_cache_alloc_node will fallback to other nodes
3108 * since memory is not yet available from the node that
3111 n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
3116 init_kmem_cache_node(n, s);
3120 up_read(&slub_lock);
3124 static int slab_memory_callback(struct notifier_block *self,
3125 unsigned long action, void *arg)
3130 case MEM_GOING_ONLINE:
3131 ret = slab_mem_going_online_callback(arg);
3133 case MEM_GOING_OFFLINE:
3134 ret = slab_mem_going_offline_callback(arg);
3137 case MEM_CANCEL_ONLINE:
3138 slab_mem_offline_callback(arg);
3141 case MEM_CANCEL_OFFLINE:
3145 ret = notifier_from_errno(ret);
3151 #endif /* CONFIG_MEMORY_HOTPLUG */
3153 /********************************************************************
3154 * Basic setup of slabs
3155 *******************************************************************/
3158 * Used for early kmem_cache structures that were allocated using
3159 * the page allocator
3162 static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)
3166 list_add(&s->list, &slab_caches);
3169 for_each_node_state(node, N_NORMAL_MEMORY) {
3170 struct kmem_cache_node *n = get_node(s, node);
3174 list_for_each_entry(p, &n->partial, lru)
3177 #ifdef CONFIG_SLAB_DEBUG
3178 list_for_each_entry(p, &n->full, lru)
3185 void __init kmem_cache_init(void)
3189 struct kmem_cache *temp_kmem_cache;
3191 struct kmem_cache *temp_kmem_cache_node;
3192 unsigned long kmalloc_size;
3194 kmem_size = offsetof(struct kmem_cache, node) +
3195 nr_node_ids * sizeof(struct kmem_cache_node *);
3197 /* Allocate two kmem_caches from the page allocator */
3198 kmalloc_size = ALIGN(kmem_size, cache_line_size());
3199 order = get_order(2 * kmalloc_size);
3200 kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order);
3203 * Must first have the slab cache available for the allocations of the
3204 * struct kmem_cache_node's. There is special bootstrap code in
3205 * kmem_cache_open for slab_state == DOWN.
3207 kmem_cache_node = (void *)kmem_cache + kmalloc_size;
3209 kmem_cache_open(kmem_cache_node, "kmem_cache_node",
3210 sizeof(struct kmem_cache_node),
3211 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
3213 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
3215 /* Able to allocate the per node structures */
3216 slab_state = PARTIAL;
3218 temp_kmem_cache = kmem_cache;
3219 kmem_cache_open(kmem_cache, "kmem_cache", kmem_size,
3220 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
3221 kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
3222 memcpy(kmem_cache, temp_kmem_cache, kmem_size);
3225 * Allocate kmem_cache_node properly from the kmem_cache slab.
3226 * kmem_cache_node is separately allocated so no need to
3227 * update any list pointers.
3229 temp_kmem_cache_node = kmem_cache_node;
3231 kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
3232 memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size);
3234 kmem_cache_bootstrap_fixup(kmem_cache_node);
3237 kmem_cache_bootstrap_fixup(kmem_cache);
3239 /* Free temporary boot structure */
3240 free_pages((unsigned long)temp_kmem_cache, order);
3242 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3245 * Patch up the size_index table if we have strange large alignment
3246 * requirements for the kmalloc array. This is only the case for
3247 * MIPS it seems. The standard arches will not generate any code here.
3249 * Largest permitted alignment is 256 bytes due to the way we
3250 * handle the index determination for the smaller caches.
3252 * Make sure that nothing crazy happens if someone starts tinkering
3253 * around with ARCH_KMALLOC_MINALIGN
3255 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
3256 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
3258 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
3259 int elem = size_index_elem(i);
3260 if (elem >= ARRAY_SIZE(size_index))
3262 size_index[elem] = KMALLOC_SHIFT_LOW;
3265 if (KMALLOC_MIN_SIZE == 64) {
3267 * The 96 byte size cache is not used if the alignment
3270 for (i = 64 + 8; i <= 96; i += 8)
3271 size_index[size_index_elem(i)] = 7;
3272 } else if (KMALLOC_MIN_SIZE == 128) {
3274 * The 192 byte sized cache is not used if the alignment
3275 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3278 for (i = 128 + 8; i <= 192; i += 8)
3279 size_index[size_index_elem(i)] = 8;
3282 /* Caches that are not of the two-to-the-power-of size */
3283 if (KMALLOC_MIN_SIZE <= 32) {
3284 kmalloc_caches[1] = create_kmalloc_cache("kmalloc-96", 96, 0);
3288 if (KMALLOC_MIN_SIZE <= 64) {
3289 kmalloc_caches[2] = create_kmalloc_cache("kmalloc-192", 192, 0);
3293 for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
3294 kmalloc_caches[i] = create_kmalloc_cache("kmalloc", 1 << i, 0);
3300 /* Provide the correct kmalloc names now that the caches are up */
3301 if (KMALLOC_MIN_SIZE <= 32) {
3302 kmalloc_caches[1]->name = kstrdup(kmalloc_caches[1]->name, GFP_NOWAIT);
3303 BUG_ON(!kmalloc_caches[1]->name);
3306 if (KMALLOC_MIN_SIZE <= 64) {
3307 kmalloc_caches[2]->name = kstrdup(kmalloc_caches[2]->name, GFP_NOWAIT);
3308 BUG_ON(!kmalloc_caches[2]->name);
3311 for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
3312 char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i);
3315 kmalloc_caches[i]->name = s;
3319 register_cpu_notifier(&slab_notifier);
3322 #ifdef CONFIG_ZONE_DMA
3323 for (i = 0; i < SLUB_PAGE_SHIFT; i++) {
3324 struct kmem_cache *s = kmalloc_caches[i];
3327 char *name = kasprintf(GFP_NOWAIT,
3328 "dma-kmalloc-%d", s->objsize);
3331 kmalloc_dma_caches[i] = create_kmalloc_cache(name,
3332 s->objsize, SLAB_CACHE_DMA);
3337 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3338 " CPUs=%d, Nodes=%d\n",
3339 caches, cache_line_size(),
3340 slub_min_order, slub_max_order, slub_min_objects,
3341 nr_cpu_ids, nr_node_ids);
3344 void __init kmem_cache_init_late(void)
3349 * Find a mergeable slab cache
3351 static int slab_unmergeable(struct kmem_cache *s)
3353 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
3360 * We may have set a slab to be unmergeable during bootstrap.
3362 if (s->refcount < 0)
3368 static struct kmem_cache *find_mergeable(size_t size,
3369 size_t align, unsigned long flags, const char *name,
3370 void (*ctor)(void *))
3372 struct kmem_cache *s;
3374 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
3380 size = ALIGN(size, sizeof(void *));
3381 align = calculate_alignment(flags, align, size);
3382 size = ALIGN(size, align);
3383 flags = kmem_cache_flags(size, flags, name, NULL);
3385 list_for_each_entry(s, &slab_caches, list) {
3386 if (slab_unmergeable(s))
3392 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
3395 * Check if alignment is compatible.
3396 * Courtesy of Adrian Drzewiecki
3398 if ((s->size & ~(align - 1)) != s->size)
3401 if (s->size - size >= sizeof(void *))
3409 struct kmem_cache *kmem_cache_create(const char *name, size_t size,
3410 size_t align, unsigned long flags, void (*ctor)(void *))
3412 struct kmem_cache *s;
3418 down_write(&slub_lock);
3419 s = find_mergeable(size, align, flags, name, ctor);
3423 * Adjust the object sizes so that we clear
3424 * the complete object on kzalloc.
3426 s->objsize = max(s->objsize, (int)size);
3427 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
3429 if (sysfs_slab_alias(s, name)) {
3433 up_write(&slub_lock);
3437 n = kstrdup(name, GFP_KERNEL);
3441 s = kmalloc(kmem_size, GFP_KERNEL);
3443 if (kmem_cache_open(s, n,
3444 size, align, flags, ctor)) {
3445 list_add(&s->list, &slab_caches);
3446 if (sysfs_slab_add(s)) {
3452 up_write(&slub_lock);
3459 up_write(&slub_lock);
3461 if (flags & SLAB_PANIC)
3462 panic("Cannot create slabcache %s\n", name);
3467 EXPORT_SYMBOL(kmem_cache_create);
3471 * Use the cpu notifier to insure that the cpu slabs are flushed when
3474 static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3475 unsigned long action, void *hcpu)
3477 long cpu = (long)hcpu;
3478 struct kmem_cache *s;
3479 unsigned long flags;
3482 case CPU_UP_CANCELED:
3483 case CPU_UP_CANCELED_FROZEN:
3485 case CPU_DEAD_FROZEN:
3486 down_read(&slub_lock);
3487 list_for_each_entry(s, &slab_caches, list) {
3488 local_irq_save(flags);
3489 __flush_cpu_slab(s, cpu);
3490 local_irq_restore(flags);
3492 up_read(&slub_lock);
3500 static struct notifier_block __cpuinitdata slab_notifier = {
3501 .notifier_call = slab_cpuup_callback
3506 void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
3508 struct kmem_cache *s;
3511 if (unlikely(size > SLUB_MAX_SIZE))
3512 return kmalloc_large(size, gfpflags);
3514 s = get_slab(size, gfpflags);
3516 if (unlikely(ZERO_OR_NULL_PTR(s)))
3519 ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller);
3521 /* Honor the call site pointer we recieved. */
3522 trace_kmalloc(caller, ret, size, s->size, gfpflags);
3528 void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3529 int node, unsigned long caller)
3531 struct kmem_cache *s;
3534 if (unlikely(size > SLUB_MAX_SIZE)) {
3535 ret = kmalloc_large_node(size, gfpflags, node);
3537 trace_kmalloc_node(caller, ret,
3538 size, PAGE_SIZE << get_order(size),
3544 s = get_slab(size, gfpflags);
3546 if (unlikely(ZERO_OR_NULL_PTR(s)))
3549 ret = slab_alloc(s, gfpflags, node, caller);
3551 /* Honor the call site pointer we recieved. */
3552 trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
3559 static int count_inuse(struct page *page)
3564 static int count_total(struct page *page)
3566 return page->objects;
3570 #ifdef CONFIG_SLUB_DEBUG
3571 static int validate_slab(struct kmem_cache *s, struct page *page,
3575 void *addr = page_address(page);
3577 if (!check_slab(s, page) ||
3578 !on_freelist(s, page, NULL))
3581 /* Now we know that a valid freelist exists */
3582 bitmap_zero(map, page->objects);
3584 for_each_free_object(p, s, page->freelist) {
3585 set_bit(slab_index(p, s, addr), map);
3586 if (!check_object(s, page, p, SLUB_RED_INACTIVE))
3590 for_each_object(p, s, addr, page->objects)
3591 if (!test_bit(slab_index(p, s, addr), map))
3592 if (!check_object(s, page, p, SLUB_RED_ACTIVE))
3597 static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3600 if (slab_trylock(page)) {
3601 validate_slab(s, page, map);
3604 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3608 static int validate_slab_node(struct kmem_cache *s,
3609 struct kmem_cache_node *n, unsigned long *map)
3611 unsigned long count = 0;
3613 unsigned long flags;
3615 spin_lock_irqsave(&n->list_lock, flags);
3617 list_for_each_entry(page, &n->partial, lru) {
3618 validate_slab_slab(s, page, map);
3621 if (count != n->nr_partial)
3622 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3623 "counter=%ld\n", s->name, count, n->nr_partial);
3625 if (!(s->flags & SLAB_STORE_USER))
3628 list_for_each_entry(page, &n->full, lru) {
3629 validate_slab_slab(s, page, map);
3632 if (count != atomic_long_read(&n->nr_slabs))
3633 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3634 "counter=%ld\n", s->name, count,
3635 atomic_long_read(&n->nr_slabs));
3638 spin_unlock_irqrestore(&n->list_lock, flags);
3642 static long validate_slab_cache(struct kmem_cache *s)
3645 unsigned long count = 0;
3646 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
3647 sizeof(unsigned long), GFP_KERNEL);
3653 for_each_node_state(node, N_NORMAL_MEMORY) {
3654 struct kmem_cache_node *n = get_node(s, node);
3656 count += validate_slab_node(s, n, map);
3662 * Generate lists of code addresses where slabcache objects are allocated
3667 unsigned long count;
3674 DECLARE_BITMAP(cpus, NR_CPUS);
3680 unsigned long count;
3681 struct location *loc;
3684 static void free_loc_track(struct loc_track *t)
3687 free_pages((unsigned long)t->loc,
3688 get_order(sizeof(struct location) * t->max));
3691 static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
3696 order = get_order(sizeof(struct location) * max);
3698 l = (void *)__get_free_pages(flags, order);
3703 memcpy(l, t->loc, sizeof(struct location) * t->count);
3711 static int add_location(struct loc_track *t, struct kmem_cache *s,
3712 const struct track *track)
3714 long start, end, pos;
3716 unsigned long caddr;
3717 unsigned long age = jiffies - track->when;
3723 pos = start + (end - start + 1) / 2;
3726 * There is nothing at "end". If we end up there
3727 * we need to add something to before end.
3732 caddr = t->loc[pos].addr;
3733 if (track->addr == caddr) {
3739 if (age < l->min_time)
3741 if (age > l->max_time)
3744 if (track->pid < l->min_pid)
3745 l->min_pid = track->pid;
3746 if (track->pid > l->max_pid)
3747 l->max_pid = track->pid;
3749 cpumask_set_cpu(track->cpu,
3750 to_cpumask(l->cpus));
3752 node_set(page_to_nid(virt_to_page(track)), l->nodes);
3756 if (track->addr < caddr)
3763 * Not found. Insert new tracking element.
3765 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
3771 (t->count - pos) * sizeof(struct location));
3774 l->addr = track->addr;
3778 l->min_pid = track->pid;
3779 l->max_pid = track->pid;
3780 cpumask_clear(to_cpumask(l->cpus));
3781 cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
3782 nodes_clear(l->nodes);
3783 node_set(page_to_nid(virt_to_page(track)), l->nodes);
3787 static void process_slab(struct loc_track *t, struct kmem_cache *s,
3788 struct page *page, enum track_item alloc,
3791 void *addr = page_address(page);
3794 bitmap_zero(map, page->objects);
3795 for_each_free_object(p, s, page->freelist)
3796 set_bit(slab_index(p, s, addr), map);
3798 for_each_object(p, s, addr, page->objects)
3799 if (!test_bit(slab_index(p, s, addr), map))
3800 add_location(t, s, get_track(s, p, alloc));
3803 static int list_locations(struct kmem_cache *s, char *buf,
3804 enum track_item alloc)
3808 struct loc_track t = { 0, 0, NULL };
3810 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
3811 sizeof(unsigned long), GFP_KERNEL);
3813 if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
3816 return sprintf(buf, "Out of memory\n");
3818 /* Push back cpu slabs */
3821 for_each_node_state(node, N_NORMAL_MEMORY) {
3822 struct kmem_cache_node *n = get_node(s, node);
3823 unsigned long flags;
3826 if (!atomic_long_read(&n->nr_slabs))
3829 spin_lock_irqsave(&n->list_lock, flags);
3830 list_for_each_entry(page, &n->partial, lru)
3831 process_slab(&t, s, page, alloc, map);
3832 list_for_each_entry(page, &n->full, lru)
3833 process_slab(&t, s, page, alloc, map);
3834 spin_unlock_irqrestore(&n->list_lock, flags);
3837 for (i = 0; i < t.count; i++) {
3838 struct location *l = &t.loc[i];
3840 if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100)
3842 len += sprintf(buf + len, "%7ld ", l->count);
3845 len += sprintf(buf + len, "%pS", (void *)l->addr);
3847 len += sprintf(buf + len, "<not-available>");
3849 if (l->sum_time != l->min_time) {
3850 len += sprintf(buf + len, " age=%ld/%ld/%ld",
3852 (long)div_u64(l->sum_time, l->count),
3855 len += sprintf(buf + len, " age=%ld",
3858 if (l->min_pid != l->max_pid)
3859 len += sprintf(buf + len, " pid=%ld-%ld",
3860 l->min_pid, l->max_pid);
3862 len += sprintf(buf + len, " pid=%ld",
3865 if (num_online_cpus() > 1 &&
3866 !cpumask_empty(to_cpumask(l->cpus)) &&
3867 len < PAGE_SIZE - 60) {
3868 len += sprintf(buf + len, " cpus=");
3869 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
3870 to_cpumask(l->cpus));
3873 if (nr_online_nodes > 1 && !nodes_empty(l->nodes) &&
3874 len < PAGE_SIZE - 60) {
3875 len += sprintf(buf + len, " nodes=");
3876 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
3880 len += sprintf(buf + len, "\n");
3886 len += sprintf(buf, "No data\n");
3891 #ifdef SLUB_RESILIENCY_TEST
3892 static void resiliency_test(void)
3896 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || SLUB_PAGE_SHIFT < 10);
3898 printk(KERN_ERR "SLUB resiliency testing\n");
3899 printk(KERN_ERR "-----------------------\n");
3900 printk(KERN_ERR "A. Corruption after allocation\n");
3902 p = kzalloc(16, GFP_KERNEL);
3904 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3905 " 0x12->0x%p\n\n", p + 16);
3907 validate_slab_cache(kmalloc_caches[4]);
3909 /* Hmmm... The next two are dangerous */
3910 p = kzalloc(32, GFP_KERNEL);
3911 p[32 + sizeof(void *)] = 0x34;
3912 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
3913 " 0x34 -> -0x%p\n", p);
3915 "If allocated object is overwritten then not detectable\n\n");
3917 validate_slab_cache(kmalloc_caches[5]);
3918 p = kzalloc(64, GFP_KERNEL);
3919 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3921 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3924 "If allocated object is overwritten then not detectable\n\n");
3925 validate_slab_cache(kmalloc_caches[6]);
3927 printk(KERN_ERR "\nB. Corruption after free\n");
3928 p = kzalloc(128, GFP_KERNEL);
3931 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3932 validate_slab_cache(kmalloc_caches[7]);
3934 p = kzalloc(256, GFP_KERNEL);
3937 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3939 validate_slab_cache(kmalloc_caches[8]);
3941 p = kzalloc(512, GFP_KERNEL);
3944 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3945 validate_slab_cache(kmalloc_caches[9]);
3949 static void resiliency_test(void) {};
3954 enum slab_stat_type {
3955 SL_ALL, /* All slabs */
3956 SL_PARTIAL, /* Only partially allocated slabs */
3957 SL_CPU, /* Only slabs used for cpu caches */
3958 SL_OBJECTS, /* Determine allocated objects not slabs */
3959 SL_TOTAL /* Determine object capacity not slabs */
3962 #define SO_ALL (1 << SL_ALL)
3963 #define SO_PARTIAL (1 << SL_PARTIAL)
3964 #define SO_CPU (1 << SL_CPU)
3965 #define SO_OBJECTS (1 << SL_OBJECTS)
3966 #define SO_TOTAL (1 << SL_TOTAL)
3968 static ssize_t show_slab_objects(struct kmem_cache *s,
3969 char *buf, unsigned long flags)
3971 unsigned long total = 0;
3974 unsigned long *nodes;
3975 unsigned long *per_cpu;
3977 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
3980 per_cpu = nodes + nr_node_ids;
3982 if (flags & SO_CPU) {
3985 for_each_possible_cpu(cpu) {
3986 struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
3988 if (!c || c->node < 0)
3992 if (flags & SO_TOTAL)
3993 x = c->page->objects;
3994 else if (flags & SO_OBJECTS)
4000 nodes[c->node] += x;
4006 lock_memory_hotplug();
4007 #ifdef CONFIG_SLUB_DEBUG
4008 if (flags & SO_ALL) {
4009 for_each_node_state(node, N_NORMAL_MEMORY) {
4010 struct kmem_cache_node *n = get_node(s, node);
4012 if (flags & SO_TOTAL)
4013 x = atomic_long_read(&n->total_objects);
4014 else if (flags & SO_OBJECTS)
4015 x = atomic_long_read(&n->total_objects) -
4016 count_partial(n, count_free);
4019 x = atomic_long_read(&n->nr_slabs);
4026 if (flags & SO_PARTIAL) {
4027 for_each_node_state(node, N_NORMAL_MEMORY) {
4028 struct kmem_cache_node *n = get_node(s, node);
4030 if (flags & SO_TOTAL)
4031 x = count_partial(n, count_total);
4032 else if (flags & SO_OBJECTS)
4033 x = count_partial(n, count_inuse);
4040 x = sprintf(buf, "%lu", total);
4042 for_each_node_state(node, N_NORMAL_MEMORY)
4044 x += sprintf(buf + x, " N%d=%lu",
4047 unlock_memory_hotplug();
4049 return x + sprintf(buf + x, "\n");
4052 #ifdef CONFIG_SLUB_DEBUG
4053 static int any_slab_objects(struct kmem_cache *s)
4057 for_each_online_node(node) {
4058 struct kmem_cache_node *n = get_node(s, node);
4063 if (atomic_long_read(&n->total_objects))
4070 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4071 #define to_slab(n) container_of(n, struct kmem_cache, kobj);
4073 struct slab_attribute {
4074 struct attribute attr;
4075 ssize_t (*show)(struct kmem_cache *s, char *buf);
4076 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
4079 #define SLAB_ATTR_RO(_name) \
4080 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
4082 #define SLAB_ATTR(_name) \
4083 static struct slab_attribute _name##_attr = \
4084 __ATTR(_name, 0644, _name##_show, _name##_store)
4086 static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
4088 return sprintf(buf, "%d\n", s->size);
4090 SLAB_ATTR_RO(slab_size);
4092 static ssize_t align_show(struct kmem_cache *s, char *buf)
4094 return sprintf(buf, "%d\n", s->align);
4096 SLAB_ATTR_RO(align);
4098 static ssize_t object_size_show(struct kmem_cache *s, char *buf)
4100 return sprintf(buf, "%d\n", s->objsize);
4102 SLAB_ATTR_RO(object_size);
4104 static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
4106 return sprintf(buf, "%d\n", oo_objects(s->oo));
4108 SLAB_ATTR_RO(objs_per_slab);
4110 static ssize_t order_store(struct kmem_cache *s,
4111 const char *buf, size_t length)
4113 unsigned long order;
4116 err = strict_strtoul(buf, 10, &order);
4120 if (order > slub_max_order || order < slub_min_order)
4123 calculate_sizes(s, order);
4127 static ssize_t order_show(struct kmem_cache *s, char *buf)
4129 return sprintf(buf, "%d\n", oo_order(s->oo));
4133 static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
4135 return sprintf(buf, "%lu\n", s->min_partial);
4138 static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
4144 err = strict_strtoul(buf, 10, &min);
4148 set_min_partial(s, min);
4151 SLAB_ATTR(min_partial);
4153 static ssize_t ctor_show(struct kmem_cache *s, char *buf)
4157 return sprintf(buf, "%pS\n", s->ctor);
4161 static ssize_t aliases_show(struct kmem_cache *s, char *buf)
4163 return sprintf(buf, "%d\n", s->refcount - 1);
4165 SLAB_ATTR_RO(aliases);
4167 static ssize_t partial_show(struct kmem_cache *s, char *buf)
4169 return show_slab_objects(s, buf, SO_PARTIAL);
4171 SLAB_ATTR_RO(partial);
4173 static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
4175 return show_slab_objects(s, buf, SO_CPU);
4177 SLAB_ATTR_RO(cpu_slabs);
4179 static ssize_t objects_show(struct kmem_cache *s, char *buf)
4181 return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
4183 SLAB_ATTR_RO(objects);
4185 static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
4187 return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
4189 SLAB_ATTR_RO(objects_partial);
4191 static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
4193 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
4196 static ssize_t reclaim_account_store(struct kmem_cache *s,
4197 const char *buf, size_t length)
4199 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
4201 s->flags |= SLAB_RECLAIM_ACCOUNT;
4204 SLAB_ATTR(reclaim_account);
4206 static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
4208 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
4210 SLAB_ATTR_RO(hwcache_align);
4212 #ifdef CONFIG_ZONE_DMA
4213 static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
4215 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
4217 SLAB_ATTR_RO(cache_dma);
4220 static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
4222 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
4224 SLAB_ATTR_RO(destroy_by_rcu);
4226 #ifdef CONFIG_SLUB_DEBUG
4227 static ssize_t slabs_show(struct kmem_cache *s, char *buf)
4229 return show_slab_objects(s, buf, SO_ALL);
4231 SLAB_ATTR_RO(slabs);
4233 static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
4235 return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
4237 SLAB_ATTR_RO(total_objects);
4239 static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
4241 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
4244 static ssize_t sanity_checks_store(struct kmem_cache *s,
4245 const char *buf, size_t length)
4247 s->flags &= ~SLAB_DEBUG_FREE;
4249 s->flags |= SLAB_DEBUG_FREE;
4252 SLAB_ATTR(sanity_checks);
4254 static ssize_t trace_show(struct kmem_cache *s, char *buf)
4256 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
4259 static ssize_t trace_store(struct kmem_cache *s, const char *buf,
4262 s->flags &= ~SLAB_TRACE;
4264 s->flags |= SLAB_TRACE;
4269 static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
4271 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
4274 static ssize_t red_zone_store(struct kmem_cache *s,
4275 const char *buf, size_t length)
4277 if (any_slab_objects(s))
4280 s->flags &= ~SLAB_RED_ZONE;
4282 s->flags |= SLAB_RED_ZONE;
4283 calculate_sizes(s, -1);
4286 SLAB_ATTR(red_zone);
4288 static ssize_t poison_show(struct kmem_cache *s, char *buf)
4290 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
4293 static ssize_t poison_store(struct kmem_cache *s,
4294 const char *buf, size_t length)
4296 if (any_slab_objects(s))
4299 s->flags &= ~SLAB_POISON;
4301 s->flags |= SLAB_POISON;
4302 calculate_sizes(s, -1);
4307 static ssize_t store_user_show(struct kmem_cache *s, char *buf)
4309 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
4312 static ssize_t store_user_store(struct kmem_cache *s,
4313 const char *buf, size_t length)
4315 if (any_slab_objects(s))
4318 s->flags &= ~SLAB_STORE_USER;
4320 s->flags |= SLAB_STORE_USER;
4321 calculate_sizes(s, -1);
4324 SLAB_ATTR(store_user);
4326 static ssize_t validate_show(struct kmem_cache *s, char *buf)
4331 static ssize_t validate_store(struct kmem_cache *s,
4332 const char *buf, size_t length)
4336 if (buf[0] == '1') {
4337 ret = validate_slab_cache(s);
4343 SLAB_ATTR(validate);
4345 static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
4347 if (!(s->flags & SLAB_STORE_USER))
4349 return list_locations(s, buf, TRACK_ALLOC);
4351 SLAB_ATTR_RO(alloc_calls);
4353 static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
4355 if (!(s->flags & SLAB_STORE_USER))
4357 return list_locations(s, buf, TRACK_FREE);
4359 SLAB_ATTR_RO(free_calls);
4360 #endif /* CONFIG_SLUB_DEBUG */
4362 #ifdef CONFIG_FAILSLAB
4363 static ssize_t failslab_show(struct kmem_cache *s, char *buf)
4365 return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
4368 static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
4371 s->flags &= ~SLAB_FAILSLAB;
4373 s->flags |= SLAB_FAILSLAB;
4376 SLAB_ATTR(failslab);
4379 static ssize_t shrink_show(struct kmem_cache *s, char *buf)
4384 static ssize_t shrink_store(struct kmem_cache *s,
4385 const char *buf, size_t length)
4387 if (buf[0] == '1') {
4388 int rc = kmem_cache_shrink(s);
4399 static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
4401 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
4404 static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
4405 const char *buf, size_t length)
4407 unsigned long ratio;
4410 err = strict_strtoul(buf, 10, &ratio);
4415 s->remote_node_defrag_ratio = ratio * 10;
4419 SLAB_ATTR(remote_node_defrag_ratio);
4422 #ifdef CONFIG_SLUB_STATS
4423 static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
4425 unsigned long sum = 0;
4428 int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
4433 for_each_online_cpu(cpu) {
4434 unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
4440 len = sprintf(buf, "%lu", sum);
4443 for_each_online_cpu(cpu) {
4444 if (data[cpu] && len < PAGE_SIZE - 20)
4445 len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
4449 return len + sprintf(buf + len, "\n");
4452 static void clear_stat(struct kmem_cache *s, enum stat_item si)
4456 for_each_online_cpu(cpu)
4457 per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
4460 #define STAT_ATTR(si, text) \
4461 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4463 return show_stat(s, buf, si); \
4465 static ssize_t text##_store(struct kmem_cache *s, \
4466 const char *buf, size_t length) \
4468 if (buf[0] != '0') \
4470 clear_stat(s, si); \
4475 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4476 STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
4477 STAT_ATTR(FREE_FASTPATH, free_fastpath);
4478 STAT_ATTR(FREE_SLOWPATH, free_slowpath);
4479 STAT_ATTR(FREE_FROZEN, free_frozen);
4480 STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
4481 STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
4482 STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
4483 STAT_ATTR(ALLOC_SLAB, alloc_slab);
4484 STAT_ATTR(ALLOC_REFILL, alloc_refill);
4485 STAT_ATTR(FREE_SLAB, free_slab);
4486 STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
4487 STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
4488 STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
4489 STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
4490 STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
4491 STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
4492 STAT_ATTR(ORDER_FALLBACK, order_fallback);
4495 static struct attribute *slab_attrs[] = {
4496 &slab_size_attr.attr,
4497 &object_size_attr.attr,
4498 &objs_per_slab_attr.attr,
4500 &min_partial_attr.attr,
4502 &objects_partial_attr.attr,
4504 &cpu_slabs_attr.attr,
4508 &hwcache_align_attr.attr,
4509 &reclaim_account_attr.attr,
4510 &destroy_by_rcu_attr.attr,
4512 #ifdef CONFIG_SLUB_DEBUG
4513 &total_objects_attr.attr,
4515 &sanity_checks_attr.attr,
4517 &red_zone_attr.attr,
4519 &store_user_attr.attr,
4520 &validate_attr.attr,
4521 &alloc_calls_attr.attr,
4522 &free_calls_attr.attr,
4524 #ifdef CONFIG_ZONE_DMA
4525 &cache_dma_attr.attr,
4528 &remote_node_defrag_ratio_attr.attr,
4530 #ifdef CONFIG_SLUB_STATS
4531 &alloc_fastpath_attr.attr,
4532 &alloc_slowpath_attr.attr,
4533 &free_fastpath_attr.attr,
4534 &free_slowpath_attr.attr,
4535 &free_frozen_attr.attr,
4536 &free_add_partial_attr.attr,
4537 &free_remove_partial_attr.attr,
4538 &alloc_from_partial_attr.attr,
4539 &alloc_slab_attr.attr,
4540 &alloc_refill_attr.attr,
4541 &free_slab_attr.attr,
4542 &cpuslab_flush_attr.attr,
4543 &deactivate_full_attr.attr,
4544 &deactivate_empty_attr.attr,
4545 &deactivate_to_head_attr.attr,
4546 &deactivate_to_tail_attr.attr,
4547 &deactivate_remote_frees_attr.attr,
4548 &order_fallback_attr.attr,
4550 #ifdef CONFIG_FAILSLAB
4551 &failslab_attr.attr,
4557 static struct attribute_group slab_attr_group = {
4558 .attrs = slab_attrs,
4561 static ssize_t slab_attr_show(struct kobject *kobj,
4562 struct attribute *attr,
4565 struct slab_attribute *attribute;
4566 struct kmem_cache *s;
4569 attribute = to_slab_attr(attr);
4572 if (!attribute->show)
4575 err = attribute->show(s, buf);
4580 static ssize_t slab_attr_store(struct kobject *kobj,
4581 struct attribute *attr,
4582 const char *buf, size_t len)
4584 struct slab_attribute *attribute;
4585 struct kmem_cache *s;
4588 attribute = to_slab_attr(attr);
4591 if (!attribute->store)
4594 err = attribute->store(s, buf, len);
4599 static void kmem_cache_release(struct kobject *kobj)
4601 struct kmem_cache *s = to_slab(kobj);
4607 static const struct sysfs_ops slab_sysfs_ops = {
4608 .show = slab_attr_show,
4609 .store = slab_attr_store,
4612 static struct kobj_type slab_ktype = {
4613 .sysfs_ops = &slab_sysfs_ops,
4614 .release = kmem_cache_release
4617 static int uevent_filter(struct kset *kset, struct kobject *kobj)
4619 struct kobj_type *ktype = get_ktype(kobj);
4621 if (ktype == &slab_ktype)
4626 static const struct kset_uevent_ops slab_uevent_ops = {
4627 .filter = uevent_filter,
4630 static struct kset *slab_kset;
4632 #define ID_STR_LENGTH 64
4634 /* Create a unique string id for a slab cache:
4636 * Format :[flags-]size
4638 static char *create_unique_id(struct kmem_cache *s)
4640 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
4647 * First flags affecting slabcache operations. We will only
4648 * get here for aliasable slabs so we do not need to support
4649 * too many flags. The flags here must cover all flags that
4650 * are matched during merging to guarantee that the id is
4653 if (s->flags & SLAB_CACHE_DMA)
4655 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4657 if (s->flags & SLAB_DEBUG_FREE)
4659 if (!(s->flags & SLAB_NOTRACK))
4663 p += sprintf(p, "%07d", s->size);
4664 BUG_ON(p > name + ID_STR_LENGTH - 1);
4668 static int sysfs_slab_add(struct kmem_cache *s)
4674 if (slab_state < SYSFS)
4675 /* Defer until later */
4678 unmergeable = slab_unmergeable(s);
4681 * Slabcache can never be merged so we can use the name proper.
4682 * This is typically the case for debug situations. In that
4683 * case we can catch duplicate names easily.
4685 sysfs_remove_link(&slab_kset->kobj, s->name);
4689 * Create a unique name for the slab as a target
4692 name = create_unique_id(s);
4695 s->kobj.kset = slab_kset;
4696 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4698 kobject_put(&s->kobj);
4702 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4704 kobject_del(&s->kobj);
4705 kobject_put(&s->kobj);
4708 kobject_uevent(&s->kobj, KOBJ_ADD);
4710 /* Setup first alias */
4711 sysfs_slab_alias(s, s->name);
4717 static void sysfs_slab_remove(struct kmem_cache *s)
4719 if (slab_state < SYSFS)
4721 * Sysfs has not been setup yet so no need to remove the
4726 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4727 kobject_del(&s->kobj);
4728 kobject_put(&s->kobj);
4732 * Need to buffer aliases during bootup until sysfs becomes
4733 * available lest we lose that information.
4735 struct saved_alias {
4736 struct kmem_cache *s;
4738 struct saved_alias *next;
4741 static struct saved_alias *alias_list;
4743 static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4745 struct saved_alias *al;
4747 if (slab_state == SYSFS) {
4749 * If we have a leftover link then remove it.
4751 sysfs_remove_link(&slab_kset->kobj, name);
4752 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
4755 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4761 al->next = alias_list;
4766 static int __init slab_sysfs_init(void)
4768 struct kmem_cache *s;
4771 down_write(&slub_lock);
4773 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
4775 up_write(&slub_lock);
4776 printk(KERN_ERR "Cannot register slab subsystem.\n");
4782 list_for_each_entry(s, &slab_caches, list) {
4783 err = sysfs_slab_add(s);
4785 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4786 " to sysfs\n", s->name);
4789 while (alias_list) {
4790 struct saved_alias *al = alias_list;
4792 alias_list = alias_list->next;
4793 err = sysfs_slab_alias(al->s, al->name);
4795 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4796 " %s to sysfs\n", s->name);
4800 up_write(&slub_lock);
4805 __initcall(slab_sysfs_init);
4806 #endif /* CONFIG_SYSFS */
4809 * The /proc/slabinfo ABI
4811 #ifdef CONFIG_SLABINFO
4812 static void print_slabinfo_header(struct seq_file *m)
4814 seq_puts(m, "slabinfo - version: 2.1\n");
4815 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4816 "<objperslab> <pagesperslab>");
4817 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4818 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4822 static void *s_start(struct seq_file *m, loff_t *pos)
4826 down_read(&slub_lock);
4828 print_slabinfo_header(m);
4830 return seq_list_start(&slab_caches, *pos);
4833 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4835 return seq_list_next(p, &slab_caches, pos);
4838 static void s_stop(struct seq_file *m, void *p)
4840 up_read(&slub_lock);
4843 static int s_show(struct seq_file *m, void *p)
4845 unsigned long nr_partials = 0;
4846 unsigned long nr_slabs = 0;
4847 unsigned long nr_inuse = 0;
4848 unsigned long nr_objs = 0;
4849 unsigned long nr_free = 0;
4850 struct kmem_cache *s;
4853 s = list_entry(p, struct kmem_cache, list);
4855 for_each_online_node(node) {
4856 struct kmem_cache_node *n = get_node(s, node);
4861 nr_partials += n->nr_partial;
4862 nr_slabs += atomic_long_read(&n->nr_slabs);
4863 nr_objs += atomic_long_read(&n->total_objects);
4864 nr_free += count_partial(n, count_free);
4867 nr_inuse = nr_objs - nr_free;
4869 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
4870 nr_objs, s->size, oo_objects(s->oo),
4871 (1 << oo_order(s->oo)));
4872 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4873 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4879 static const struct seq_operations slabinfo_op = {
4886 static int slabinfo_open(struct inode *inode, struct file *file)
4888 return seq_open(file, &slabinfo_op);
4891 static const struct file_operations proc_slabinfo_operations = {
4892 .open = slabinfo_open,
4894 .llseek = seq_lseek,
4895 .release = seq_release,
4898 static int __init slab_proc_init(void)
4900 proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
4903 module_init(slab_proc_init);
4904 #endif /* CONFIG_SLABINFO */