mmc: SDHI should depend on SUPERH || ARCH_SHMOBILE
[cris-mirror.git] / mm / slub.c
blobf881874843a5ff67a3d1cef595c35bf72a3c3565
1 /*
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
9 */
11 #include <linux/mm.h>
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>
34 * Lock order:
35 * 1. slab_lock(page)
36 * 2. slab->list_lock
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
55 * the list lock.
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);
118 #else
119 return 0;
120 #endif
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
153 * metadata.
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 | \
162 SLAB_FAILSLAB)
164 #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
165 SLAB_CACHE_DMA | SLAB_NOTRACK)
167 #define OO_SHIFT 16
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);
176 #ifdef CONFIG_SMP
177 static struct notifier_block slab_notifier;
178 #endif
180 static enum {
181 DOWN, /* No slab functionality available */
182 PARTIAL, /* Kmem_cache_node works */
183 UP, /* Everything works but does not show up in sysfs */
184 SYSFS /* Sysfs up */
185 } slab_state = DOWN;
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.
194 struct track {
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 };
203 #ifdef CONFIG_SYSFS
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 *);
208 #else
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)
211 { return 0; }
212 static inline void sysfs_slab_remove(struct kmem_cache *s)
214 kfree(s->name);
215 kfree(s);
218 #endif
220 static inline void stat(const struct kmem_cache *s, enum stat_item si)
222 #ifdef CONFIG_SLUB_STATS
223 __this_cpu_inc(s->cpu_slab->stat[si]);
224 #endif
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)
245 void *base;
247 if (!object)
248 return 1;
250 base = page_address(page);
251 if (object < base || object >= base + page->objects * s->size ||
252 (object - base) % s->size) {
253 return 0;
256 return 1;
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;\
272 __p += (__s)->size)
274 /* Scan freelist */
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 size_t slab_ksize(const struct kmem_cache *s)
286 #ifdef CONFIG_SLUB_DEBUG
288 * Debugging requires use of the padding between object
289 * and whatever may come after it.
291 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
292 return s->objsize;
294 #endif
296 * If we have the need to store the freelist pointer
297 * back there or track user information then we can
298 * only use the space before that information.
300 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
301 return s->inuse;
303 * Else we can use all the padding etc for the allocation
305 return s->size;
308 static inline int order_objects(int order, unsigned long size, int reserved)
310 return ((PAGE_SIZE << order) - reserved) / size;
313 static inline struct kmem_cache_order_objects oo_make(int order,
314 unsigned long size, int reserved)
316 struct kmem_cache_order_objects x = {
317 (order << OO_SHIFT) + order_objects(order, size, reserved)
320 return x;
323 static inline int oo_order(struct kmem_cache_order_objects x)
325 return x.x >> OO_SHIFT;
328 static inline int oo_objects(struct kmem_cache_order_objects x)
330 return x.x & OO_MASK;
333 #ifdef CONFIG_SLUB_DEBUG
335 * Debug settings:
337 #ifdef CONFIG_SLUB_DEBUG_ON
338 static int slub_debug = DEBUG_DEFAULT_FLAGS;
339 #else
340 static int slub_debug;
341 #endif
343 static char *slub_debug_slabs;
344 static int disable_higher_order_debug;
347 * Object debugging
349 static void print_section(char *text, u8 *addr, unsigned int length)
351 int i, offset;
352 int newline = 1;
353 char ascii[17];
355 ascii[16] = 0;
357 for (i = 0; i < length; i++) {
358 if (newline) {
359 printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
360 newline = 0;
362 printk(KERN_CONT " %02x", addr[i]);
363 offset = i % 16;
364 ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
365 if (offset == 15) {
366 printk(KERN_CONT " %s\n", ascii);
367 newline = 1;
370 if (!newline) {
371 i %= 16;
372 while (i < 16) {
373 printk(KERN_CONT " ");
374 ascii[i] = ' ';
375 i++;
377 printk(KERN_CONT " %s\n", ascii);
381 static struct track *get_track(struct kmem_cache *s, void *object,
382 enum track_item alloc)
384 struct track *p;
386 if (s->offset)
387 p = object + s->offset + sizeof(void *);
388 else
389 p = object + s->inuse;
391 return p + alloc;
394 static void set_track(struct kmem_cache *s, void *object,
395 enum track_item alloc, unsigned long addr)
397 struct track *p = get_track(s, object, alloc);
399 if (addr) {
400 p->addr = addr;
401 p->cpu = smp_processor_id();
402 p->pid = current->pid;
403 p->when = jiffies;
404 } else
405 memset(p, 0, sizeof(struct track));
408 static void init_tracking(struct kmem_cache *s, void *object)
410 if (!(s->flags & SLAB_STORE_USER))
411 return;
413 set_track(s, object, TRACK_FREE, 0UL);
414 set_track(s, object, TRACK_ALLOC, 0UL);
417 static void print_track(const char *s, struct track *t)
419 if (!t->addr)
420 return;
422 printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
423 s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid);
426 static void print_tracking(struct kmem_cache *s, void *object)
428 if (!(s->flags & SLAB_STORE_USER))
429 return;
431 print_track("Allocated", get_track(s, object, TRACK_ALLOC));
432 print_track("Freed", get_track(s, object, TRACK_FREE));
435 static void print_page_info(struct page *page)
437 printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
438 page, page->objects, page->inuse, page->freelist, page->flags);
442 static void slab_bug(struct kmem_cache *s, char *fmt, ...)
444 va_list args;
445 char buf[100];
447 va_start(args, fmt);
448 vsnprintf(buf, sizeof(buf), fmt, args);
449 va_end(args);
450 printk(KERN_ERR "========================================"
451 "=====================================\n");
452 printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
453 printk(KERN_ERR "----------------------------------------"
454 "-------------------------------------\n\n");
457 static void slab_fix(struct kmem_cache *s, char *fmt, ...)
459 va_list args;
460 char buf[100];
462 va_start(args, fmt);
463 vsnprintf(buf, sizeof(buf), fmt, args);
464 va_end(args);
465 printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
468 static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
470 unsigned int off; /* Offset of last byte */
471 u8 *addr = page_address(page);
473 print_tracking(s, p);
475 print_page_info(page);
477 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
478 p, p - addr, get_freepointer(s, p));
480 if (p > addr + 16)
481 print_section("Bytes b4", p - 16, 16);
483 print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE));
485 if (s->flags & SLAB_RED_ZONE)
486 print_section("Redzone", p + s->objsize,
487 s->inuse - s->objsize);
489 if (s->offset)
490 off = s->offset + sizeof(void *);
491 else
492 off = s->inuse;
494 if (s->flags & SLAB_STORE_USER)
495 off += 2 * sizeof(struct track);
497 if (off != s->size)
498 /* Beginning of the filler is the free pointer */
499 print_section("Padding", p + off, s->size - off);
501 dump_stack();
504 static void object_err(struct kmem_cache *s, struct page *page,
505 u8 *object, char *reason)
507 slab_bug(s, "%s", reason);
508 print_trailer(s, page, object);
511 static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
513 va_list args;
514 char buf[100];
516 va_start(args, fmt);
517 vsnprintf(buf, sizeof(buf), fmt, args);
518 va_end(args);
519 slab_bug(s, "%s", buf);
520 print_page_info(page);
521 dump_stack();
524 static void init_object(struct kmem_cache *s, void *object, u8 val)
526 u8 *p = object;
528 if (s->flags & __OBJECT_POISON) {
529 memset(p, POISON_FREE, s->objsize - 1);
530 p[s->objsize - 1] = POISON_END;
533 if (s->flags & SLAB_RED_ZONE)
534 memset(p + s->objsize, val, s->inuse - s->objsize);
537 static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes)
539 while (bytes) {
540 if (*start != (u8)value)
541 return start;
542 start++;
543 bytes--;
545 return NULL;
548 static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
549 void *from, void *to)
551 slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
552 memset(from, data, to - from);
555 static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
556 u8 *object, char *what,
557 u8 *start, unsigned int value, unsigned int bytes)
559 u8 *fault;
560 u8 *end;
562 fault = check_bytes(start, value, bytes);
563 if (!fault)
564 return 1;
566 end = start + bytes;
567 while (end > fault && end[-1] == value)
568 end--;
570 slab_bug(s, "%s overwritten", what);
571 printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
572 fault, end - 1, fault[0], value);
573 print_trailer(s, page, object);
575 restore_bytes(s, what, value, fault, end);
576 return 0;
580 * Object layout:
582 * object address
583 * Bytes of the object to be managed.
584 * If the freepointer may overlay the object then the free
585 * pointer is the first word of the object.
587 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
588 * 0xa5 (POISON_END)
590 * object + s->objsize
591 * Padding to reach word boundary. This is also used for Redzoning.
592 * Padding is extended by another word if Redzoning is enabled and
593 * objsize == inuse.
595 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
596 * 0xcc (RED_ACTIVE) for objects in use.
598 * object + s->inuse
599 * Meta data starts here.
601 * A. Free pointer (if we cannot overwrite object on free)
602 * B. Tracking data for SLAB_STORE_USER
603 * C. Padding to reach required alignment boundary or at mininum
604 * one word if debugging is on to be able to detect writes
605 * before the word boundary.
607 * Padding is done using 0x5a (POISON_INUSE)
609 * object + s->size
610 * Nothing is used beyond s->size.
612 * If slabcaches are merged then the objsize and inuse boundaries are mostly
613 * ignored. And therefore no slab options that rely on these boundaries
614 * may be used with merged slabcaches.
617 static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
619 unsigned long off = s->inuse; /* The end of info */
621 if (s->offset)
622 /* Freepointer is placed after the object. */
623 off += sizeof(void *);
625 if (s->flags & SLAB_STORE_USER)
626 /* We also have user information there */
627 off += 2 * sizeof(struct track);
629 if (s->size == off)
630 return 1;
632 return check_bytes_and_report(s, page, p, "Object padding",
633 p + off, POISON_INUSE, s->size - off);
636 /* Check the pad bytes at the end of a slab page */
637 static int slab_pad_check(struct kmem_cache *s, struct page *page)
639 u8 *start;
640 u8 *fault;
641 u8 *end;
642 int length;
643 int remainder;
645 if (!(s->flags & SLAB_POISON))
646 return 1;
648 start = page_address(page);
649 length = (PAGE_SIZE << compound_order(page)) - s->reserved;
650 end = start + length;
651 remainder = length % s->size;
652 if (!remainder)
653 return 1;
655 fault = check_bytes(end - remainder, POISON_INUSE, remainder);
656 if (!fault)
657 return 1;
658 while (end > fault && end[-1] == POISON_INUSE)
659 end--;
661 slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
662 print_section("Padding", end - remainder, remainder);
664 restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
665 return 0;
668 static int check_object(struct kmem_cache *s, struct page *page,
669 void *object, u8 val)
671 u8 *p = object;
672 u8 *endobject = object + s->objsize;
674 if (s->flags & SLAB_RED_ZONE) {
675 if (!check_bytes_and_report(s, page, object, "Redzone",
676 endobject, val, s->inuse - s->objsize))
677 return 0;
678 } else {
679 if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
680 check_bytes_and_report(s, page, p, "Alignment padding",
681 endobject, POISON_INUSE, s->inuse - s->objsize);
685 if (s->flags & SLAB_POISON) {
686 if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) &&
687 (!check_bytes_and_report(s, page, p, "Poison", p,
688 POISON_FREE, s->objsize - 1) ||
689 !check_bytes_and_report(s, page, p, "Poison",
690 p + s->objsize - 1, POISON_END, 1)))
691 return 0;
693 * check_pad_bytes cleans up on its own.
695 check_pad_bytes(s, page, p);
698 if (!s->offset && val == SLUB_RED_ACTIVE)
700 * Object and freepointer overlap. Cannot check
701 * freepointer while object is allocated.
703 return 1;
705 /* Check free pointer validity */
706 if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
707 object_err(s, page, p, "Freepointer corrupt");
709 * No choice but to zap it and thus lose the remainder
710 * of the free objects in this slab. May cause
711 * another error because the object count is now wrong.
713 set_freepointer(s, p, NULL);
714 return 0;
716 return 1;
719 static int check_slab(struct kmem_cache *s, struct page *page)
721 int maxobj;
723 VM_BUG_ON(!irqs_disabled());
725 if (!PageSlab(page)) {
726 slab_err(s, page, "Not a valid slab page");
727 return 0;
730 maxobj = order_objects(compound_order(page), s->size, s->reserved);
731 if (page->objects > maxobj) {
732 slab_err(s, page, "objects %u > max %u",
733 s->name, page->objects, maxobj);
734 return 0;
736 if (page->inuse > page->objects) {
737 slab_err(s, page, "inuse %u > max %u",
738 s->name, page->inuse, page->objects);
739 return 0;
741 /* Slab_pad_check fixes things up after itself */
742 slab_pad_check(s, page);
743 return 1;
747 * Determine if a certain object on a page is on the freelist. Must hold the
748 * slab lock to guarantee that the chains are in a consistent state.
750 static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
752 int nr = 0;
753 void *fp = page->freelist;
754 void *object = NULL;
755 unsigned long max_objects;
757 while (fp && nr <= page->objects) {
758 if (fp == search)
759 return 1;
760 if (!check_valid_pointer(s, page, fp)) {
761 if (object) {
762 object_err(s, page, object,
763 "Freechain corrupt");
764 set_freepointer(s, object, NULL);
765 break;
766 } else {
767 slab_err(s, page, "Freepointer corrupt");
768 page->freelist = NULL;
769 page->inuse = page->objects;
770 slab_fix(s, "Freelist cleared");
771 return 0;
773 break;
775 object = fp;
776 fp = get_freepointer(s, object);
777 nr++;
780 max_objects = order_objects(compound_order(page), s->size, s->reserved);
781 if (max_objects > MAX_OBJS_PER_PAGE)
782 max_objects = MAX_OBJS_PER_PAGE;
784 if (page->objects != max_objects) {
785 slab_err(s, page, "Wrong number of objects. Found %d but "
786 "should be %d", page->objects, max_objects);
787 page->objects = max_objects;
788 slab_fix(s, "Number of objects adjusted.");
790 if (page->inuse != page->objects - nr) {
791 slab_err(s, page, "Wrong object count. Counter is %d but "
792 "counted were %d", page->inuse, page->objects - nr);
793 page->inuse = page->objects - nr;
794 slab_fix(s, "Object count adjusted.");
796 return search == NULL;
799 static void trace(struct kmem_cache *s, struct page *page, void *object,
800 int alloc)
802 if (s->flags & SLAB_TRACE) {
803 printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
804 s->name,
805 alloc ? "alloc" : "free",
806 object, page->inuse,
807 page->freelist);
809 if (!alloc)
810 print_section("Object", (void *)object, s->objsize);
812 dump_stack();
817 * Hooks for other subsystems that check memory allocations. In a typical
818 * production configuration these hooks all should produce no code at all.
820 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
822 flags &= gfp_allowed_mask;
823 lockdep_trace_alloc(flags);
824 might_sleep_if(flags & __GFP_WAIT);
826 return should_failslab(s->objsize, flags, s->flags);
829 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object)
831 flags &= gfp_allowed_mask;
832 kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
833 kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags);
836 static inline void slab_free_hook(struct kmem_cache *s, void *x)
838 kmemleak_free_recursive(x, s->flags);
841 * Trouble is that we may no longer disable interupts in the fast path
842 * So in order to make the debug calls that expect irqs to be
843 * disabled we need to disable interrupts temporarily.
845 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
847 unsigned long flags;
849 local_irq_save(flags);
850 kmemcheck_slab_free(s, x, s->objsize);
851 debug_check_no_locks_freed(x, s->objsize);
852 local_irq_restore(flags);
854 #endif
855 if (!(s->flags & SLAB_DEBUG_OBJECTS))
856 debug_check_no_obj_freed(x, s->objsize);
860 * Tracking of fully allocated slabs for debugging purposes.
862 static void add_full(struct kmem_cache_node *n, struct page *page)
864 spin_lock(&n->list_lock);
865 list_add(&page->lru, &n->full);
866 spin_unlock(&n->list_lock);
869 static void remove_full(struct kmem_cache *s, struct page *page)
871 struct kmem_cache_node *n;
873 if (!(s->flags & SLAB_STORE_USER))
874 return;
876 n = get_node(s, page_to_nid(page));
878 spin_lock(&n->list_lock);
879 list_del(&page->lru);
880 spin_unlock(&n->list_lock);
883 /* Tracking of the number of slabs for debugging purposes */
884 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
886 struct kmem_cache_node *n = get_node(s, node);
888 return atomic_long_read(&n->nr_slabs);
891 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
893 return atomic_long_read(&n->nr_slabs);
896 static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
898 struct kmem_cache_node *n = get_node(s, node);
901 * May be called early in order to allocate a slab for the
902 * kmem_cache_node structure. Solve the chicken-egg
903 * dilemma by deferring the increment of the count during
904 * bootstrap (see early_kmem_cache_node_alloc).
906 if (n) {
907 atomic_long_inc(&n->nr_slabs);
908 atomic_long_add(objects, &n->total_objects);
911 static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
913 struct kmem_cache_node *n = get_node(s, node);
915 atomic_long_dec(&n->nr_slabs);
916 atomic_long_sub(objects, &n->total_objects);
919 /* Object debug checks for alloc/free paths */
920 static void setup_object_debug(struct kmem_cache *s, struct page *page,
921 void *object)
923 if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
924 return;
926 init_object(s, object, SLUB_RED_INACTIVE);
927 init_tracking(s, object);
930 static noinline int alloc_debug_processing(struct kmem_cache *s, struct page *page,
931 void *object, unsigned long addr)
933 if (!check_slab(s, page))
934 goto bad;
936 if (!on_freelist(s, page, object)) {
937 object_err(s, page, object, "Object already allocated");
938 goto bad;
941 if (!check_valid_pointer(s, page, object)) {
942 object_err(s, page, object, "Freelist Pointer check fails");
943 goto bad;
946 if (!check_object(s, page, object, SLUB_RED_INACTIVE))
947 goto bad;
949 /* Success perform special debug activities for allocs */
950 if (s->flags & SLAB_STORE_USER)
951 set_track(s, object, TRACK_ALLOC, addr);
952 trace(s, page, object, 1);
953 init_object(s, object, SLUB_RED_ACTIVE);
954 return 1;
956 bad:
957 if (PageSlab(page)) {
959 * If this is a slab page then lets do the best we can
960 * to avoid issues in the future. Marking all objects
961 * as used avoids touching the remaining objects.
963 slab_fix(s, "Marking all objects used");
964 page->inuse = page->objects;
965 page->freelist = NULL;
967 return 0;
970 static noinline int free_debug_processing(struct kmem_cache *s,
971 struct page *page, void *object, unsigned long addr)
973 if (!check_slab(s, page))
974 goto fail;
976 if (!check_valid_pointer(s, page, object)) {
977 slab_err(s, page, "Invalid object pointer 0x%p", object);
978 goto fail;
981 if (on_freelist(s, page, object)) {
982 object_err(s, page, object, "Object already free");
983 goto fail;
986 if (!check_object(s, page, object, SLUB_RED_ACTIVE))
987 return 0;
989 if (unlikely(s != page->slab)) {
990 if (!PageSlab(page)) {
991 slab_err(s, page, "Attempt to free object(0x%p) "
992 "outside of slab", object);
993 } else if (!page->slab) {
994 printk(KERN_ERR
995 "SLUB <none>: no slab for object 0x%p.\n",
996 object);
997 dump_stack();
998 } else
999 object_err(s, page, object,
1000 "page slab pointer corrupt.");
1001 goto fail;
1004 /* Special debug activities for freeing objects */
1005 if (!PageSlubFrozen(page) && !page->freelist)
1006 remove_full(s, page);
1007 if (s->flags & SLAB_STORE_USER)
1008 set_track(s, object, TRACK_FREE, addr);
1009 trace(s, page, object, 0);
1010 init_object(s, object, SLUB_RED_INACTIVE);
1011 return 1;
1013 fail:
1014 slab_fix(s, "Object at 0x%p not freed", object);
1015 return 0;
1018 static int __init setup_slub_debug(char *str)
1020 slub_debug = DEBUG_DEFAULT_FLAGS;
1021 if (*str++ != '=' || !*str)
1023 * No options specified. Switch on full debugging.
1025 goto out;
1027 if (*str == ',')
1029 * No options but restriction on slabs. This means full
1030 * debugging for slabs matching a pattern.
1032 goto check_slabs;
1034 if (tolower(*str) == 'o') {
1036 * Avoid enabling debugging on caches if its minimum order
1037 * would increase as a result.
1039 disable_higher_order_debug = 1;
1040 goto out;
1043 slub_debug = 0;
1044 if (*str == '-')
1046 * Switch off all debugging measures.
1048 goto out;
1051 * Determine which debug features should be switched on
1053 for (; *str && *str != ','; str++) {
1054 switch (tolower(*str)) {
1055 case 'f':
1056 slub_debug |= SLAB_DEBUG_FREE;
1057 break;
1058 case 'z':
1059 slub_debug |= SLAB_RED_ZONE;
1060 break;
1061 case 'p':
1062 slub_debug |= SLAB_POISON;
1063 break;
1064 case 'u':
1065 slub_debug |= SLAB_STORE_USER;
1066 break;
1067 case 't':
1068 slub_debug |= SLAB_TRACE;
1069 break;
1070 case 'a':
1071 slub_debug |= SLAB_FAILSLAB;
1072 break;
1073 default:
1074 printk(KERN_ERR "slub_debug option '%c' "
1075 "unknown. skipped\n", *str);
1079 check_slabs:
1080 if (*str == ',')
1081 slub_debug_slabs = str + 1;
1082 out:
1083 return 1;
1086 __setup("slub_debug", setup_slub_debug);
1088 static unsigned long kmem_cache_flags(unsigned long objsize,
1089 unsigned long flags, const char *name,
1090 void (*ctor)(void *))
1093 * Enable debugging if selected on the kernel commandline.
1095 if (slub_debug && (!slub_debug_slabs ||
1096 !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
1097 flags |= slub_debug;
1099 return flags;
1101 #else
1102 static inline void setup_object_debug(struct kmem_cache *s,
1103 struct page *page, void *object) {}
1105 static inline int alloc_debug_processing(struct kmem_cache *s,
1106 struct page *page, void *object, unsigned long addr) { return 0; }
1108 static inline int free_debug_processing(struct kmem_cache *s,
1109 struct page *page, void *object, unsigned long addr) { return 0; }
1111 static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
1112 { return 1; }
1113 static inline int check_object(struct kmem_cache *s, struct page *page,
1114 void *object, u8 val) { return 1; }
1115 static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
1116 static inline unsigned long kmem_cache_flags(unsigned long objsize,
1117 unsigned long flags, const char *name,
1118 void (*ctor)(void *))
1120 return flags;
1122 #define slub_debug 0
1124 #define disable_higher_order_debug 0
1126 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
1127 { return 0; }
1128 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
1129 { return 0; }
1130 static inline void inc_slabs_node(struct kmem_cache *s, int node,
1131 int objects) {}
1132 static inline void dec_slabs_node(struct kmem_cache *s, int node,
1133 int objects) {}
1135 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
1136 { return 0; }
1138 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
1139 void *object) {}
1141 static inline void slab_free_hook(struct kmem_cache *s, void *x) {}
1143 #endif /* CONFIG_SLUB_DEBUG */
1146 * Slab allocation and freeing
1148 static inline struct page *alloc_slab_page(gfp_t flags, int node,
1149 struct kmem_cache_order_objects oo)
1151 int order = oo_order(oo);
1153 flags |= __GFP_NOTRACK;
1155 if (node == NUMA_NO_NODE)
1156 return alloc_pages(flags, order);
1157 else
1158 return alloc_pages_exact_node(node, flags, order);
1161 static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1163 struct page *page;
1164 struct kmem_cache_order_objects oo = s->oo;
1165 gfp_t alloc_gfp;
1167 flags |= s->allocflags;
1170 * Let the initial higher-order allocation fail under memory pressure
1171 * so we fall-back to the minimum order allocation.
1173 alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
1175 page = alloc_slab_page(alloc_gfp, node, oo);
1176 if (unlikely(!page)) {
1177 oo = s->min;
1179 * Allocation may have failed due to fragmentation.
1180 * Try a lower order alloc if possible
1182 page = alloc_slab_page(flags, node, oo);
1183 if (!page)
1184 return NULL;
1186 stat(s, ORDER_FALLBACK);
1189 if (kmemcheck_enabled
1190 && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
1191 int pages = 1 << oo_order(oo);
1193 kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
1196 * Objects from caches that have a constructor don't get
1197 * cleared when they're allocated, so we need to do it here.
1199 if (s->ctor)
1200 kmemcheck_mark_uninitialized_pages(page, pages);
1201 else
1202 kmemcheck_mark_unallocated_pages(page, pages);
1205 page->objects = oo_objects(oo);
1206 mod_zone_page_state(page_zone(page),
1207 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1208 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1209 1 << oo_order(oo));
1211 return page;
1214 static void setup_object(struct kmem_cache *s, struct page *page,
1215 void *object)
1217 setup_object_debug(s, page, object);
1218 if (unlikely(s->ctor))
1219 s->ctor(object);
1222 static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1224 struct page *page;
1225 void *start;
1226 void *last;
1227 void *p;
1229 BUG_ON(flags & GFP_SLAB_BUG_MASK);
1231 page = allocate_slab(s,
1232 flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
1233 if (!page)
1234 goto out;
1236 inc_slabs_node(s, page_to_nid(page), page->objects);
1237 page->slab = s;
1238 page->flags |= 1 << PG_slab;
1240 start = page_address(page);
1242 if (unlikely(s->flags & SLAB_POISON))
1243 memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
1245 last = start;
1246 for_each_object(p, s, start, page->objects) {
1247 setup_object(s, page, last);
1248 set_freepointer(s, last, p);
1249 last = p;
1251 setup_object(s, page, last);
1252 set_freepointer(s, last, NULL);
1254 page->freelist = start;
1255 page->inuse = 0;
1256 out:
1257 return page;
1260 static void __free_slab(struct kmem_cache *s, struct page *page)
1262 int order = compound_order(page);
1263 int pages = 1 << order;
1265 if (kmem_cache_debug(s)) {
1266 void *p;
1268 slab_pad_check(s, page);
1269 for_each_object(p, s, page_address(page),
1270 page->objects)
1271 check_object(s, page, p, SLUB_RED_INACTIVE);
1274 kmemcheck_free_shadow(page, compound_order(page));
1276 mod_zone_page_state(page_zone(page),
1277 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1278 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1279 -pages);
1281 __ClearPageSlab(page);
1282 reset_page_mapcount(page);
1283 if (current->reclaim_state)
1284 current->reclaim_state->reclaimed_slab += pages;
1285 __free_pages(page, order);
1288 #define need_reserve_slab_rcu \
1289 (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
1291 static void rcu_free_slab(struct rcu_head *h)
1293 struct page *page;
1295 if (need_reserve_slab_rcu)
1296 page = virt_to_head_page(h);
1297 else
1298 page = container_of((struct list_head *)h, struct page, lru);
1300 __free_slab(page->slab, page);
1303 static void free_slab(struct kmem_cache *s, struct page *page)
1305 if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
1306 struct rcu_head *head;
1308 if (need_reserve_slab_rcu) {
1309 int order = compound_order(page);
1310 int offset = (PAGE_SIZE << order) - s->reserved;
1312 VM_BUG_ON(s->reserved != sizeof(*head));
1313 head = page_address(page) + offset;
1314 } else {
1316 * RCU free overloads the RCU head over the LRU
1318 head = (void *)&page->lru;
1321 call_rcu(head, rcu_free_slab);
1322 } else
1323 __free_slab(s, page);
1326 static void discard_slab(struct kmem_cache *s, struct page *page)
1328 dec_slabs_node(s, page_to_nid(page), page->objects);
1329 free_slab(s, page);
1333 * Per slab locking using the pagelock
1335 static __always_inline void slab_lock(struct page *page)
1337 bit_spin_lock(PG_locked, &page->flags);
1340 static __always_inline void slab_unlock(struct page *page)
1342 __bit_spin_unlock(PG_locked, &page->flags);
1345 static __always_inline int slab_trylock(struct page *page)
1347 int rc = 1;
1349 rc = bit_spin_trylock(PG_locked, &page->flags);
1350 return rc;
1354 * Management of partially allocated slabs
1356 static void add_partial(struct kmem_cache_node *n,
1357 struct page *page, int tail)
1359 spin_lock(&n->list_lock);
1360 n->nr_partial++;
1361 if (tail)
1362 list_add_tail(&page->lru, &n->partial);
1363 else
1364 list_add(&page->lru, &n->partial);
1365 spin_unlock(&n->list_lock);
1368 static inline void __remove_partial(struct kmem_cache_node *n,
1369 struct page *page)
1371 list_del(&page->lru);
1372 n->nr_partial--;
1375 static void remove_partial(struct kmem_cache *s, struct page *page)
1377 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1379 spin_lock(&n->list_lock);
1380 __remove_partial(n, page);
1381 spin_unlock(&n->list_lock);
1385 * Lock slab and remove from the partial list.
1387 * Must hold list_lock.
1389 static inline int lock_and_freeze_slab(struct kmem_cache_node *n,
1390 struct page *page)
1392 if (slab_trylock(page)) {
1393 __remove_partial(n, page);
1394 __SetPageSlubFrozen(page);
1395 return 1;
1397 return 0;
1401 * Try to allocate a partial slab from a specific node.
1403 static struct page *get_partial_node(struct kmem_cache_node *n)
1405 struct page *page;
1408 * Racy check. If we mistakenly see no partial slabs then we
1409 * just allocate an empty slab. If we mistakenly try to get a
1410 * partial slab and there is none available then get_partials()
1411 * will return NULL.
1413 if (!n || !n->nr_partial)
1414 return NULL;
1416 spin_lock(&n->list_lock);
1417 list_for_each_entry(page, &n->partial, lru)
1418 if (lock_and_freeze_slab(n, page))
1419 goto out;
1420 page = NULL;
1421 out:
1422 spin_unlock(&n->list_lock);
1423 return page;
1427 * Get a page from somewhere. Search in increasing NUMA distances.
1429 static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
1431 #ifdef CONFIG_NUMA
1432 struct zonelist *zonelist;
1433 struct zoneref *z;
1434 struct zone *zone;
1435 enum zone_type high_zoneidx = gfp_zone(flags);
1436 struct page *page;
1439 * The defrag ratio allows a configuration of the tradeoffs between
1440 * inter node defragmentation and node local allocations. A lower
1441 * defrag_ratio increases the tendency to do local allocations
1442 * instead of attempting to obtain partial slabs from other nodes.
1444 * If the defrag_ratio is set to 0 then kmalloc() always
1445 * returns node local objects. If the ratio is higher then kmalloc()
1446 * may return off node objects because partial slabs are obtained
1447 * from other nodes and filled up.
1449 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1450 * defrag_ratio = 1000) then every (well almost) allocation will
1451 * first attempt to defrag slab caches on other nodes. This means
1452 * scanning over all nodes to look for partial slabs which may be
1453 * expensive if we do it every time we are trying to find a slab
1454 * with available objects.
1456 if (!s->remote_node_defrag_ratio ||
1457 get_cycles() % 1024 > s->remote_node_defrag_ratio)
1458 return NULL;
1460 get_mems_allowed();
1461 zonelist = node_zonelist(slab_node(current->mempolicy), flags);
1462 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
1463 struct kmem_cache_node *n;
1465 n = get_node(s, zone_to_nid(zone));
1467 if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
1468 n->nr_partial > s->min_partial) {
1469 page = get_partial_node(n);
1470 if (page) {
1471 put_mems_allowed();
1472 return page;
1476 put_mems_allowed();
1477 #endif
1478 return NULL;
1482 * Get a partial page, lock it and return it.
1484 static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
1486 struct page *page;
1487 int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
1489 page = get_partial_node(get_node(s, searchnode));
1490 if (page || node != -1)
1491 return page;
1493 return get_any_partial(s, flags);
1497 * Move a page back to the lists.
1499 * Must be called with the slab lock held.
1501 * On exit the slab lock will have been dropped.
1503 static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
1504 __releases(bitlock)
1506 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1508 __ClearPageSlubFrozen(page);
1509 if (page->inuse) {
1511 if (page->freelist) {
1512 add_partial(n, page, tail);
1513 stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
1514 } else {
1515 stat(s, DEACTIVATE_FULL);
1516 if (kmem_cache_debug(s) && (s->flags & SLAB_STORE_USER))
1517 add_full(n, page);
1519 slab_unlock(page);
1520 } else {
1521 stat(s, DEACTIVATE_EMPTY);
1522 if (n->nr_partial < s->min_partial) {
1524 * Adding an empty slab to the partial slabs in order
1525 * to avoid page allocator overhead. This slab needs
1526 * to come after the other slabs with objects in
1527 * so that the others get filled first. That way the
1528 * size of the partial list stays small.
1530 * kmem_cache_shrink can reclaim any empty slabs from
1531 * the partial list.
1533 add_partial(n, page, 1);
1534 slab_unlock(page);
1535 } else {
1536 slab_unlock(page);
1537 stat(s, FREE_SLAB);
1538 discard_slab(s, page);
1543 #ifdef CONFIG_CMPXCHG_LOCAL
1544 #ifdef CONFIG_PREEMPT
1546 * Calculate the next globally unique transaction for disambiguiation
1547 * during cmpxchg. The transactions start with the cpu number and are then
1548 * incremented by CONFIG_NR_CPUS.
1550 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1551 #else
1553 * No preemption supported therefore also no need to check for
1554 * different cpus.
1556 #define TID_STEP 1
1557 #endif
1559 static inline unsigned long next_tid(unsigned long tid)
1561 return tid + TID_STEP;
1564 static inline unsigned int tid_to_cpu(unsigned long tid)
1566 return tid % TID_STEP;
1569 static inline unsigned long tid_to_event(unsigned long tid)
1571 return tid / TID_STEP;
1574 static inline unsigned int init_tid(int cpu)
1576 return cpu;
1579 static inline void note_cmpxchg_failure(const char *n,
1580 const struct kmem_cache *s, unsigned long tid)
1582 #ifdef SLUB_DEBUG_CMPXCHG
1583 unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
1585 printk(KERN_INFO "%s %s: cmpxchg redo ", n, s->name);
1587 #ifdef CONFIG_PREEMPT
1588 if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
1589 printk("due to cpu change %d -> %d\n",
1590 tid_to_cpu(tid), tid_to_cpu(actual_tid));
1591 else
1592 #endif
1593 if (tid_to_event(tid) != tid_to_event(actual_tid))
1594 printk("due to cpu running other code. Event %ld->%ld\n",
1595 tid_to_event(tid), tid_to_event(actual_tid));
1596 else
1597 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1598 actual_tid, tid, next_tid(tid));
1599 #endif
1600 stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
1603 #endif
1605 void init_kmem_cache_cpus(struct kmem_cache *s)
1607 #ifdef CONFIG_CMPXCHG_LOCAL
1608 int cpu;
1610 for_each_possible_cpu(cpu)
1611 per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
1612 #endif
1616 * Remove the cpu slab
1618 static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
1619 __releases(bitlock)
1621 struct page *page = c->page;
1622 int tail = 1;
1624 if (page->freelist)
1625 stat(s, DEACTIVATE_REMOTE_FREES);
1627 * Merge cpu freelist into slab freelist. Typically we get here
1628 * because both freelists are empty. So this is unlikely
1629 * to occur.
1631 while (unlikely(c->freelist)) {
1632 void **object;
1634 tail = 0; /* Hot objects. Put the slab first */
1636 /* Retrieve object from cpu_freelist */
1637 object = c->freelist;
1638 c->freelist = get_freepointer(s, c->freelist);
1640 /* And put onto the regular freelist */
1641 set_freepointer(s, object, page->freelist);
1642 page->freelist = object;
1643 page->inuse--;
1645 c->page = NULL;
1646 #ifdef CONFIG_CMPXCHG_LOCAL
1647 c->tid = next_tid(c->tid);
1648 #endif
1649 unfreeze_slab(s, page, tail);
1652 static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
1654 stat(s, CPUSLAB_FLUSH);
1655 slab_lock(c->page);
1656 deactivate_slab(s, c);
1660 * Flush cpu slab.
1662 * Called from IPI handler with interrupts disabled.
1664 static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
1666 struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
1668 if (likely(c && c->page))
1669 flush_slab(s, c);
1672 static void flush_cpu_slab(void *d)
1674 struct kmem_cache *s = d;
1676 __flush_cpu_slab(s, smp_processor_id());
1679 static void flush_all(struct kmem_cache *s)
1681 on_each_cpu(flush_cpu_slab, s, 1);
1685 * Check if the objects in a per cpu structure fit numa
1686 * locality expectations.
1688 static inline int node_match(struct kmem_cache_cpu *c, int node)
1690 #ifdef CONFIG_NUMA
1691 if (node != NUMA_NO_NODE && c->node != node)
1692 return 0;
1693 #endif
1694 return 1;
1697 static int count_free(struct page *page)
1699 return page->objects - page->inuse;
1702 static unsigned long count_partial(struct kmem_cache_node *n,
1703 int (*get_count)(struct page *))
1705 unsigned long flags;
1706 unsigned long x = 0;
1707 struct page *page;
1709 spin_lock_irqsave(&n->list_lock, flags);
1710 list_for_each_entry(page, &n->partial, lru)
1711 x += get_count(page);
1712 spin_unlock_irqrestore(&n->list_lock, flags);
1713 return x;
1716 static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
1718 #ifdef CONFIG_SLUB_DEBUG
1719 return atomic_long_read(&n->total_objects);
1720 #else
1721 return 0;
1722 #endif
1725 static noinline void
1726 slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
1728 int node;
1730 printk(KERN_WARNING
1731 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
1732 nid, gfpflags);
1733 printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, "
1734 "default order: %d, min order: %d\n", s->name, s->objsize,
1735 s->size, oo_order(s->oo), oo_order(s->min));
1737 if (oo_order(s->min) > get_order(s->objsize))
1738 printk(KERN_WARNING " %s debugging increased min order, use "
1739 "slub_debug=O to disable.\n", s->name);
1741 for_each_online_node(node) {
1742 struct kmem_cache_node *n = get_node(s, node);
1743 unsigned long nr_slabs;
1744 unsigned long nr_objs;
1745 unsigned long nr_free;
1747 if (!n)
1748 continue;
1750 nr_free = count_partial(n, count_free);
1751 nr_slabs = node_nr_slabs(n);
1752 nr_objs = node_nr_objs(n);
1754 printk(KERN_WARNING
1755 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
1756 node, nr_slabs, nr_objs, nr_free);
1761 * Slow path. The lockless freelist is empty or we need to perform
1762 * debugging duties.
1764 * Interrupts are disabled.
1766 * Processing is still very fast if new objects have been freed to the
1767 * regular freelist. In that case we simply take over the regular freelist
1768 * as the lockless freelist and zap the regular freelist.
1770 * If that is not working then we fall back to the partial lists. We take the
1771 * first element of the freelist as the object to allocate now and move the
1772 * rest of the freelist to the lockless freelist.
1774 * And if we were unable to get a new slab from the partial slab lists then
1775 * we need to allocate a new slab. This is the slowest path since it involves
1776 * a call to the page allocator and the setup of a new slab.
1778 static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
1779 unsigned long addr, struct kmem_cache_cpu *c)
1781 void **object;
1782 struct page *new;
1783 #ifdef CONFIG_CMPXCHG_LOCAL
1784 unsigned long flags;
1786 local_irq_save(flags);
1787 #ifdef CONFIG_PREEMPT
1789 * We may have been preempted and rescheduled on a different
1790 * cpu before disabling interrupts. Need to reload cpu area
1791 * pointer.
1793 c = this_cpu_ptr(s->cpu_slab);
1794 #endif
1795 #endif
1797 /* We handle __GFP_ZERO in the caller */
1798 gfpflags &= ~__GFP_ZERO;
1800 if (!c->page)
1801 goto new_slab;
1803 slab_lock(c->page);
1804 if (unlikely(!node_match(c, node)))
1805 goto another_slab;
1807 stat(s, ALLOC_REFILL);
1809 load_freelist:
1810 object = c->page->freelist;
1811 if (unlikely(!object))
1812 goto another_slab;
1813 if (kmem_cache_debug(s))
1814 goto debug;
1816 c->freelist = get_freepointer(s, object);
1817 c->page->inuse = c->page->objects;
1818 c->page->freelist = NULL;
1819 c->node = page_to_nid(c->page);
1820 unlock_out:
1821 slab_unlock(c->page);
1822 #ifdef CONFIG_CMPXCHG_LOCAL
1823 c->tid = next_tid(c->tid);
1824 local_irq_restore(flags);
1825 #endif
1826 stat(s, ALLOC_SLOWPATH);
1827 return object;
1829 another_slab:
1830 deactivate_slab(s, c);
1832 new_slab:
1833 new = get_partial(s, gfpflags, node);
1834 if (new) {
1835 c->page = new;
1836 stat(s, ALLOC_FROM_PARTIAL);
1837 goto load_freelist;
1840 gfpflags &= gfp_allowed_mask;
1841 if (gfpflags & __GFP_WAIT)
1842 local_irq_enable();
1844 new = new_slab(s, gfpflags, node);
1846 if (gfpflags & __GFP_WAIT)
1847 local_irq_disable();
1849 if (new) {
1850 c = __this_cpu_ptr(s->cpu_slab);
1851 stat(s, ALLOC_SLAB);
1852 if (c->page)
1853 flush_slab(s, c);
1854 slab_lock(new);
1855 __SetPageSlubFrozen(new);
1856 c->page = new;
1857 goto load_freelist;
1859 if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
1860 slab_out_of_memory(s, gfpflags, node);
1861 #ifdef CONFIG_CMPXCHG_LOCAL
1862 local_irq_restore(flags);
1863 #endif
1864 return NULL;
1865 debug:
1866 if (!alloc_debug_processing(s, c->page, object, addr))
1867 goto another_slab;
1869 c->page->inuse++;
1870 c->page->freelist = get_freepointer(s, object);
1871 c->node = NUMA_NO_NODE;
1872 goto unlock_out;
1876 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1877 * have the fastpath folded into their functions. So no function call
1878 * overhead for requests that can be satisfied on the fastpath.
1880 * The fastpath works by first checking if the lockless freelist can be used.
1881 * If not then __slab_alloc is called for slow processing.
1883 * Otherwise we can simply pick the next object from the lockless free list.
1885 static __always_inline void *slab_alloc(struct kmem_cache *s,
1886 gfp_t gfpflags, int node, unsigned long addr)
1888 void **object;
1889 struct kmem_cache_cpu *c;
1890 #ifdef CONFIG_CMPXCHG_LOCAL
1891 unsigned long tid;
1892 #else
1893 unsigned long flags;
1894 #endif
1896 if (slab_pre_alloc_hook(s, gfpflags))
1897 return NULL;
1899 #ifndef CONFIG_CMPXCHG_LOCAL
1900 local_irq_save(flags);
1901 #else
1902 redo:
1903 #endif
1906 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
1907 * enabled. We may switch back and forth between cpus while
1908 * reading from one cpu area. That does not matter as long
1909 * as we end up on the original cpu again when doing the cmpxchg.
1911 c = __this_cpu_ptr(s->cpu_slab);
1913 #ifdef CONFIG_CMPXCHG_LOCAL
1915 * The transaction ids are globally unique per cpu and per operation on
1916 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
1917 * occurs on the right processor and that there was no operation on the
1918 * linked list in between.
1920 tid = c->tid;
1921 barrier();
1922 #endif
1924 object = c->freelist;
1925 if (unlikely(!object || !node_match(c, node)))
1927 object = __slab_alloc(s, gfpflags, node, addr, c);
1929 else {
1930 #ifdef CONFIG_CMPXCHG_LOCAL
1932 * The cmpxchg will only match if there was no additonal
1933 * operation and if we are on the right processor.
1935 * The cmpxchg does the following atomically (without lock semantics!)
1936 * 1. Relocate first pointer to the current per cpu area.
1937 * 2. Verify that tid and freelist have not been changed
1938 * 3. If they were not changed replace tid and freelist
1940 * Since this is without lock semantics the protection is only against
1941 * code executing on this cpu *not* from access by other cpus.
1943 if (unlikely(!this_cpu_cmpxchg_double(
1944 s->cpu_slab->freelist, s->cpu_slab->tid,
1945 object, tid,
1946 get_freepointer(s, object), next_tid(tid)))) {
1948 note_cmpxchg_failure("slab_alloc", s, tid);
1949 goto redo;
1951 #else
1952 c->freelist = get_freepointer(s, object);
1953 #endif
1954 stat(s, ALLOC_FASTPATH);
1957 #ifndef CONFIG_CMPXCHG_LOCAL
1958 local_irq_restore(flags);
1959 #endif
1961 if (unlikely(gfpflags & __GFP_ZERO) && object)
1962 memset(object, 0, s->objsize);
1964 slab_post_alloc_hook(s, gfpflags, object);
1966 return object;
1969 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
1971 void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
1973 trace_kmem_cache_alloc(_RET_IP_, ret, s->objsize, s->size, gfpflags);
1975 return ret;
1977 EXPORT_SYMBOL(kmem_cache_alloc);
1979 #ifdef CONFIG_TRACING
1980 void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
1982 void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
1983 trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
1984 return ret;
1986 EXPORT_SYMBOL(kmem_cache_alloc_trace);
1988 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
1990 void *ret = kmalloc_order(size, flags, order);
1991 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
1992 return ret;
1994 EXPORT_SYMBOL(kmalloc_order_trace);
1995 #endif
1997 #ifdef CONFIG_NUMA
1998 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
2000 void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
2002 trace_kmem_cache_alloc_node(_RET_IP_, ret,
2003 s->objsize, s->size, gfpflags, node);
2005 return ret;
2007 EXPORT_SYMBOL(kmem_cache_alloc_node);
2009 #ifdef CONFIG_TRACING
2010 void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
2011 gfp_t gfpflags,
2012 int node, size_t size)
2014 void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
2016 trace_kmalloc_node(_RET_IP_, ret,
2017 size, s->size, gfpflags, node);
2018 return ret;
2020 EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
2021 #endif
2022 #endif
2025 * Slow patch handling. This may still be called frequently since objects
2026 * have a longer lifetime than the cpu slabs in most processing loads.
2028 * So we still attempt to reduce cache line usage. Just take the slab
2029 * lock and free the item. If there is no additional partial page
2030 * handling required then we can return immediately.
2032 static void __slab_free(struct kmem_cache *s, struct page *page,
2033 void *x, unsigned long addr)
2035 void *prior;
2036 void **object = (void *)x;
2037 #ifdef CONFIG_CMPXCHG_LOCAL
2038 unsigned long flags;
2040 local_irq_save(flags);
2041 #endif
2042 slab_lock(page);
2043 stat(s, FREE_SLOWPATH);
2045 if (kmem_cache_debug(s))
2046 goto debug;
2048 checks_ok:
2049 prior = page->freelist;
2050 set_freepointer(s, object, prior);
2051 page->freelist = object;
2052 page->inuse--;
2054 if (unlikely(PageSlubFrozen(page))) {
2055 stat(s, FREE_FROZEN);
2056 goto out_unlock;
2059 if (unlikely(!page->inuse))
2060 goto slab_empty;
2063 * Objects left in the slab. If it was not on the partial list before
2064 * then add it.
2066 if (unlikely(!prior)) {
2067 add_partial(get_node(s, page_to_nid(page)), page, 1);
2068 stat(s, FREE_ADD_PARTIAL);
2071 out_unlock:
2072 slab_unlock(page);
2073 #ifdef CONFIG_CMPXCHG_LOCAL
2074 local_irq_restore(flags);
2075 #endif
2076 return;
2078 slab_empty:
2079 if (prior) {
2081 * Slab still on the partial list.
2083 remove_partial(s, page);
2084 stat(s, FREE_REMOVE_PARTIAL);
2086 slab_unlock(page);
2087 #ifdef CONFIG_CMPXCHG_LOCAL
2088 local_irq_restore(flags);
2089 #endif
2090 stat(s, FREE_SLAB);
2091 discard_slab(s, page);
2092 return;
2094 debug:
2095 if (!free_debug_processing(s, page, x, addr))
2096 goto out_unlock;
2097 goto checks_ok;
2101 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2102 * can perform fastpath freeing without additional function calls.
2104 * The fastpath is only possible if we are freeing to the current cpu slab
2105 * of this processor. This typically the case if we have just allocated
2106 * the item before.
2108 * If fastpath is not possible then fall back to __slab_free where we deal
2109 * with all sorts of special processing.
2111 static __always_inline void slab_free(struct kmem_cache *s,
2112 struct page *page, void *x, unsigned long addr)
2114 void **object = (void *)x;
2115 struct kmem_cache_cpu *c;
2116 #ifdef CONFIG_CMPXCHG_LOCAL
2117 unsigned long tid;
2118 #else
2119 unsigned long flags;
2120 #endif
2122 slab_free_hook(s, x);
2124 #ifndef CONFIG_CMPXCHG_LOCAL
2125 local_irq_save(flags);
2127 #else
2128 redo:
2129 #endif
2132 * Determine the currently cpus per cpu slab.
2133 * The cpu may change afterward. However that does not matter since
2134 * data is retrieved via this pointer. If we are on the same cpu
2135 * during the cmpxchg then the free will succedd.
2137 c = __this_cpu_ptr(s->cpu_slab);
2139 #ifdef CONFIG_CMPXCHG_LOCAL
2140 tid = c->tid;
2141 barrier();
2142 #endif
2144 if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
2145 set_freepointer(s, object, c->freelist);
2147 #ifdef CONFIG_CMPXCHG_LOCAL
2148 if (unlikely(!this_cpu_cmpxchg_double(
2149 s->cpu_slab->freelist, s->cpu_slab->tid,
2150 c->freelist, tid,
2151 object, next_tid(tid)))) {
2153 note_cmpxchg_failure("slab_free", s, tid);
2154 goto redo;
2156 #else
2157 c->freelist = object;
2158 #endif
2159 stat(s, FREE_FASTPATH);
2160 } else
2161 __slab_free(s, page, x, addr);
2163 #ifndef CONFIG_CMPXCHG_LOCAL
2164 local_irq_restore(flags);
2165 #endif
2168 void kmem_cache_free(struct kmem_cache *s, void *x)
2170 struct page *page;
2172 page = virt_to_head_page(x);
2174 slab_free(s, page, x, _RET_IP_);
2176 trace_kmem_cache_free(_RET_IP_, x);
2178 EXPORT_SYMBOL(kmem_cache_free);
2181 * Object placement in a slab is made very easy because we always start at
2182 * offset 0. If we tune the size of the object to the alignment then we can
2183 * get the required alignment by putting one properly sized object after
2184 * another.
2186 * Notice that the allocation order determines the sizes of the per cpu
2187 * caches. Each processor has always one slab available for allocations.
2188 * Increasing the allocation order reduces the number of times that slabs
2189 * must be moved on and off the partial lists and is therefore a factor in
2190 * locking overhead.
2194 * Mininum / Maximum order of slab pages. This influences locking overhead
2195 * and slab fragmentation. A higher order reduces the number of partial slabs
2196 * and increases the number of allocations possible without having to
2197 * take the list_lock.
2199 static int slub_min_order;
2200 static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
2201 static int slub_min_objects;
2204 * Merge control. If this is set then no merging of slab caches will occur.
2205 * (Could be removed. This was introduced to pacify the merge skeptics.)
2207 static int slub_nomerge;
2210 * Calculate the order of allocation given an slab object size.
2212 * The order of allocation has significant impact on performance and other
2213 * system components. Generally order 0 allocations should be preferred since
2214 * order 0 does not cause fragmentation in the page allocator. Larger objects
2215 * be problematic to put into order 0 slabs because there may be too much
2216 * unused space left. We go to a higher order if more than 1/16th of the slab
2217 * would be wasted.
2219 * In order to reach satisfactory performance we must ensure that a minimum
2220 * number of objects is in one slab. Otherwise we may generate too much
2221 * activity on the partial lists which requires taking the list_lock. This is
2222 * less a concern for large slabs though which are rarely used.
2224 * slub_max_order specifies the order where we begin to stop considering the
2225 * number of objects in a slab as critical. If we reach slub_max_order then
2226 * we try to keep the page order as low as possible. So we accept more waste
2227 * of space in favor of a small page order.
2229 * Higher order allocations also allow the placement of more objects in a
2230 * slab and thereby reduce object handling overhead. If the user has
2231 * requested a higher mininum order then we start with that one instead of
2232 * the smallest order which will fit the object.
2234 static inline int slab_order(int size, int min_objects,
2235 int max_order, int fract_leftover, int reserved)
2237 int order;
2238 int rem;
2239 int min_order = slub_min_order;
2241 if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE)
2242 return get_order(size * MAX_OBJS_PER_PAGE) - 1;
2244 for (order = max(min_order,
2245 fls(min_objects * size - 1) - PAGE_SHIFT);
2246 order <= max_order; order++) {
2248 unsigned long slab_size = PAGE_SIZE << order;
2250 if (slab_size < min_objects * size + reserved)
2251 continue;
2253 rem = (slab_size - reserved) % size;
2255 if (rem <= slab_size / fract_leftover)
2256 break;
2260 return order;
2263 static inline int calculate_order(int size, int reserved)
2265 int order;
2266 int min_objects;
2267 int fraction;
2268 int max_objects;
2271 * Attempt to find best configuration for a slab. This
2272 * works by first attempting to generate a layout with
2273 * the best configuration and backing off gradually.
2275 * First we reduce the acceptable waste in a slab. Then
2276 * we reduce the minimum objects required in a slab.
2278 min_objects = slub_min_objects;
2279 if (!min_objects)
2280 min_objects = 4 * (fls(nr_cpu_ids) + 1);
2281 max_objects = order_objects(slub_max_order, size, reserved);
2282 min_objects = min(min_objects, max_objects);
2284 while (min_objects > 1) {
2285 fraction = 16;
2286 while (fraction >= 4) {
2287 order = slab_order(size, min_objects,
2288 slub_max_order, fraction, reserved);
2289 if (order <= slub_max_order)
2290 return order;
2291 fraction /= 2;
2293 min_objects--;
2297 * We were unable to place multiple objects in a slab. Now
2298 * lets see if we can place a single object there.
2300 order = slab_order(size, 1, slub_max_order, 1, reserved);
2301 if (order <= slub_max_order)
2302 return order;
2305 * Doh this slab cannot be placed using slub_max_order.
2307 order = slab_order(size, 1, MAX_ORDER, 1, reserved);
2308 if (order < MAX_ORDER)
2309 return order;
2310 return -ENOSYS;
2314 * Figure out what the alignment of the objects will be.
2316 static unsigned long calculate_alignment(unsigned long flags,
2317 unsigned long align, unsigned long size)
2320 * If the user wants hardware cache aligned objects then follow that
2321 * suggestion if the object is sufficiently large.
2323 * The hardware cache alignment cannot override the specified
2324 * alignment though. If that is greater then use it.
2326 if (flags & SLAB_HWCACHE_ALIGN) {
2327 unsigned long ralign = cache_line_size();
2328 while (size <= ralign / 2)
2329 ralign /= 2;
2330 align = max(align, ralign);
2333 if (align < ARCH_SLAB_MINALIGN)
2334 align = ARCH_SLAB_MINALIGN;
2336 return ALIGN(align, sizeof(void *));
2339 static void
2340 init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
2342 n->nr_partial = 0;
2343 spin_lock_init(&n->list_lock);
2344 INIT_LIST_HEAD(&n->partial);
2345 #ifdef CONFIG_SLUB_DEBUG
2346 atomic_long_set(&n->nr_slabs, 0);
2347 atomic_long_set(&n->total_objects, 0);
2348 INIT_LIST_HEAD(&n->full);
2349 #endif
2352 static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
2354 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
2355 SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
2357 #ifdef CONFIG_CMPXCHG_LOCAL
2359 * Must align to double word boundary for the double cmpxchg instructions
2360 * to work.
2362 s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu), 2 * sizeof(void *));
2363 #else
2364 /* Regular alignment is sufficient */
2365 s->cpu_slab = alloc_percpu(struct kmem_cache_cpu);
2366 #endif
2368 if (!s->cpu_slab)
2369 return 0;
2371 init_kmem_cache_cpus(s);
2373 return 1;
2376 static struct kmem_cache *kmem_cache_node;
2379 * No kmalloc_node yet so do it by hand. We know that this is the first
2380 * slab on the node for this slabcache. There are no concurrent accesses
2381 * possible.
2383 * Note that this function only works on the kmalloc_node_cache
2384 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2385 * memory on a fresh node that has no slab structures yet.
2387 static void early_kmem_cache_node_alloc(int node)
2389 struct page *page;
2390 struct kmem_cache_node *n;
2391 unsigned long flags;
2393 BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
2395 page = new_slab(kmem_cache_node, GFP_NOWAIT, node);
2397 BUG_ON(!page);
2398 if (page_to_nid(page) != node) {
2399 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2400 "node %d\n", node);
2401 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2402 "in order to be able to continue\n");
2405 n = page->freelist;
2406 BUG_ON(!n);
2407 page->freelist = get_freepointer(kmem_cache_node, n);
2408 page->inuse++;
2409 kmem_cache_node->node[node] = n;
2410 #ifdef CONFIG_SLUB_DEBUG
2411 init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
2412 init_tracking(kmem_cache_node, n);
2413 #endif
2414 init_kmem_cache_node(n, kmem_cache_node);
2415 inc_slabs_node(kmem_cache_node, node, page->objects);
2418 * lockdep requires consistent irq usage for each lock
2419 * so even though there cannot be a race this early in
2420 * the boot sequence, we still disable irqs.
2422 local_irq_save(flags);
2423 add_partial(n, page, 0);
2424 local_irq_restore(flags);
2427 static void free_kmem_cache_nodes(struct kmem_cache *s)
2429 int node;
2431 for_each_node_state(node, N_NORMAL_MEMORY) {
2432 struct kmem_cache_node *n = s->node[node];
2434 if (n)
2435 kmem_cache_free(kmem_cache_node, n);
2437 s->node[node] = NULL;
2441 static int init_kmem_cache_nodes(struct kmem_cache *s)
2443 int node;
2445 for_each_node_state(node, N_NORMAL_MEMORY) {
2446 struct kmem_cache_node *n;
2448 if (slab_state == DOWN) {
2449 early_kmem_cache_node_alloc(node);
2450 continue;
2452 n = kmem_cache_alloc_node(kmem_cache_node,
2453 GFP_KERNEL, node);
2455 if (!n) {
2456 free_kmem_cache_nodes(s);
2457 return 0;
2460 s->node[node] = n;
2461 init_kmem_cache_node(n, s);
2463 return 1;
2466 static void set_min_partial(struct kmem_cache *s, unsigned long min)
2468 if (min < MIN_PARTIAL)
2469 min = MIN_PARTIAL;
2470 else if (min > MAX_PARTIAL)
2471 min = MAX_PARTIAL;
2472 s->min_partial = min;
2476 * calculate_sizes() determines the order and the distribution of data within
2477 * a slab object.
2479 static int calculate_sizes(struct kmem_cache *s, int forced_order)
2481 unsigned long flags = s->flags;
2482 unsigned long size = s->objsize;
2483 unsigned long align = s->align;
2484 int order;
2487 * Round up object size to the next word boundary. We can only
2488 * place the free pointer at word boundaries and this determines
2489 * the possible location of the free pointer.
2491 size = ALIGN(size, sizeof(void *));
2493 #ifdef CONFIG_SLUB_DEBUG
2495 * Determine if we can poison the object itself. If the user of
2496 * the slab may touch the object after free or before allocation
2497 * then we should never poison the object itself.
2499 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
2500 !s->ctor)
2501 s->flags |= __OBJECT_POISON;
2502 else
2503 s->flags &= ~__OBJECT_POISON;
2507 * If we are Redzoning then check if there is some space between the
2508 * end of the object and the free pointer. If not then add an
2509 * additional word to have some bytes to store Redzone information.
2511 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2512 size += sizeof(void *);
2513 #endif
2516 * With that we have determined the number of bytes in actual use
2517 * by the object. This is the potential offset to the free pointer.
2519 s->inuse = size;
2521 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
2522 s->ctor)) {
2524 * Relocate free pointer after the object if it is not
2525 * permitted to overwrite the first word of the object on
2526 * kmem_cache_free.
2528 * This is the case if we do RCU, have a constructor or
2529 * destructor or are poisoning the objects.
2531 s->offset = size;
2532 size += sizeof(void *);
2535 #ifdef CONFIG_SLUB_DEBUG
2536 if (flags & SLAB_STORE_USER)
2538 * Need to store information about allocs and frees after
2539 * the object.
2541 size += 2 * sizeof(struct track);
2543 if (flags & SLAB_RED_ZONE)
2545 * Add some empty padding so that we can catch
2546 * overwrites from earlier objects rather than let
2547 * tracking information or the free pointer be
2548 * corrupted if a user writes before the start
2549 * of the object.
2551 size += sizeof(void *);
2552 #endif
2555 * Determine the alignment based on various parameters that the
2556 * user specified and the dynamic determination of cache line size
2557 * on bootup.
2559 align = calculate_alignment(flags, align, s->objsize);
2560 s->align = align;
2563 * SLUB stores one object immediately after another beginning from
2564 * offset 0. In order to align the objects we have to simply size
2565 * each object to conform to the alignment.
2567 size = ALIGN(size, align);
2568 s->size = size;
2569 if (forced_order >= 0)
2570 order = forced_order;
2571 else
2572 order = calculate_order(size, s->reserved);
2574 if (order < 0)
2575 return 0;
2577 s->allocflags = 0;
2578 if (order)
2579 s->allocflags |= __GFP_COMP;
2581 if (s->flags & SLAB_CACHE_DMA)
2582 s->allocflags |= SLUB_DMA;
2584 if (s->flags & SLAB_RECLAIM_ACCOUNT)
2585 s->allocflags |= __GFP_RECLAIMABLE;
2588 * Determine the number of objects per slab
2590 s->oo = oo_make(order, size, s->reserved);
2591 s->min = oo_make(get_order(size), size, s->reserved);
2592 if (oo_objects(s->oo) > oo_objects(s->max))
2593 s->max = s->oo;
2595 return !!oo_objects(s->oo);
2599 static int kmem_cache_open(struct kmem_cache *s,
2600 const char *name, size_t size,
2601 size_t align, unsigned long flags,
2602 void (*ctor)(void *))
2604 memset(s, 0, kmem_size);
2605 s->name = name;
2606 s->ctor = ctor;
2607 s->objsize = size;
2608 s->align = align;
2609 s->flags = kmem_cache_flags(size, flags, name, ctor);
2610 s->reserved = 0;
2612 if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU))
2613 s->reserved = sizeof(struct rcu_head);
2615 if (!calculate_sizes(s, -1))
2616 goto error;
2617 if (disable_higher_order_debug) {
2619 * Disable debugging flags that store metadata if the min slab
2620 * order increased.
2622 if (get_order(s->size) > get_order(s->objsize)) {
2623 s->flags &= ~DEBUG_METADATA_FLAGS;
2624 s->offset = 0;
2625 if (!calculate_sizes(s, -1))
2626 goto error;
2631 * The larger the object size is, the more pages we want on the partial
2632 * list to avoid pounding the page allocator excessively.
2634 set_min_partial(s, ilog2(s->size));
2635 s->refcount = 1;
2636 #ifdef CONFIG_NUMA
2637 s->remote_node_defrag_ratio = 1000;
2638 #endif
2639 if (!init_kmem_cache_nodes(s))
2640 goto error;
2642 if (alloc_kmem_cache_cpus(s))
2643 return 1;
2645 free_kmem_cache_nodes(s);
2646 error:
2647 if (flags & SLAB_PANIC)
2648 panic("Cannot create slab %s size=%lu realsize=%u "
2649 "order=%u offset=%u flags=%lx\n",
2650 s->name, (unsigned long)size, s->size, oo_order(s->oo),
2651 s->offset, flags);
2652 return 0;
2656 * Determine the size of a slab object
2658 unsigned int kmem_cache_size(struct kmem_cache *s)
2660 return s->objsize;
2662 EXPORT_SYMBOL(kmem_cache_size);
2664 static void list_slab_objects(struct kmem_cache *s, struct page *page,
2665 const char *text)
2667 #ifdef CONFIG_SLUB_DEBUG
2668 void *addr = page_address(page);
2669 void *p;
2670 unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) *
2671 sizeof(long), GFP_ATOMIC);
2672 if (!map)
2673 return;
2674 slab_err(s, page, "%s", text);
2675 slab_lock(page);
2676 for_each_free_object(p, s, page->freelist)
2677 set_bit(slab_index(p, s, addr), map);
2679 for_each_object(p, s, addr, page->objects) {
2681 if (!test_bit(slab_index(p, s, addr), map)) {
2682 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
2683 p, p - addr);
2684 print_tracking(s, p);
2687 slab_unlock(page);
2688 kfree(map);
2689 #endif
2693 * Attempt to free all partial slabs on a node.
2695 static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
2697 unsigned long flags;
2698 struct page *page, *h;
2700 spin_lock_irqsave(&n->list_lock, flags);
2701 list_for_each_entry_safe(page, h, &n->partial, lru) {
2702 if (!page->inuse) {
2703 __remove_partial(n, page);
2704 discard_slab(s, page);
2705 } else {
2706 list_slab_objects(s, page,
2707 "Objects remaining on kmem_cache_close()");
2710 spin_unlock_irqrestore(&n->list_lock, flags);
2714 * Release all resources used by a slab cache.
2716 static inline int kmem_cache_close(struct kmem_cache *s)
2718 int node;
2720 flush_all(s);
2721 free_percpu(s->cpu_slab);
2722 /* Attempt to free all objects */
2723 for_each_node_state(node, N_NORMAL_MEMORY) {
2724 struct kmem_cache_node *n = get_node(s, node);
2726 free_partial(s, n);
2727 if (n->nr_partial || slabs_node(s, node))
2728 return 1;
2730 free_kmem_cache_nodes(s);
2731 return 0;
2735 * Close a cache and release the kmem_cache structure
2736 * (must be used for caches created using kmem_cache_create)
2738 void kmem_cache_destroy(struct kmem_cache *s)
2740 down_write(&slub_lock);
2741 s->refcount--;
2742 if (!s->refcount) {
2743 list_del(&s->list);
2744 if (kmem_cache_close(s)) {
2745 printk(KERN_ERR "SLUB %s: %s called for cache that "
2746 "still has objects.\n", s->name, __func__);
2747 dump_stack();
2749 if (s->flags & SLAB_DESTROY_BY_RCU)
2750 rcu_barrier();
2751 sysfs_slab_remove(s);
2753 up_write(&slub_lock);
2755 EXPORT_SYMBOL(kmem_cache_destroy);
2757 /********************************************************************
2758 * Kmalloc subsystem
2759 *******************************************************************/
2761 struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
2762 EXPORT_SYMBOL(kmalloc_caches);
2764 static struct kmem_cache *kmem_cache;
2766 #ifdef CONFIG_ZONE_DMA
2767 static struct kmem_cache *kmalloc_dma_caches[SLUB_PAGE_SHIFT];
2768 #endif
2770 static int __init setup_slub_min_order(char *str)
2772 get_option(&str, &slub_min_order);
2774 return 1;
2777 __setup("slub_min_order=", setup_slub_min_order);
2779 static int __init setup_slub_max_order(char *str)
2781 get_option(&str, &slub_max_order);
2782 slub_max_order = min(slub_max_order, MAX_ORDER - 1);
2784 return 1;
2787 __setup("slub_max_order=", setup_slub_max_order);
2789 static int __init setup_slub_min_objects(char *str)
2791 get_option(&str, &slub_min_objects);
2793 return 1;
2796 __setup("slub_min_objects=", setup_slub_min_objects);
2798 static int __init setup_slub_nomerge(char *str)
2800 slub_nomerge = 1;
2801 return 1;
2804 __setup("slub_nomerge", setup_slub_nomerge);
2806 static struct kmem_cache *__init create_kmalloc_cache(const char *name,
2807 int size, unsigned int flags)
2809 struct kmem_cache *s;
2811 s = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
2814 * This function is called with IRQs disabled during early-boot on
2815 * single CPU so there's no need to take slub_lock here.
2817 if (!kmem_cache_open(s, name, size, ARCH_KMALLOC_MINALIGN,
2818 flags, NULL))
2819 goto panic;
2821 list_add(&s->list, &slab_caches);
2822 return s;
2824 panic:
2825 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2826 return NULL;
2830 * Conversion table for small slabs sizes / 8 to the index in the
2831 * kmalloc array. This is necessary for slabs < 192 since we have non power
2832 * of two cache sizes there. The size of larger slabs can be determined using
2833 * fls.
2835 static s8 size_index[24] = {
2836 3, /* 8 */
2837 4, /* 16 */
2838 5, /* 24 */
2839 5, /* 32 */
2840 6, /* 40 */
2841 6, /* 48 */
2842 6, /* 56 */
2843 6, /* 64 */
2844 1, /* 72 */
2845 1, /* 80 */
2846 1, /* 88 */
2847 1, /* 96 */
2848 7, /* 104 */
2849 7, /* 112 */
2850 7, /* 120 */
2851 7, /* 128 */
2852 2, /* 136 */
2853 2, /* 144 */
2854 2, /* 152 */
2855 2, /* 160 */
2856 2, /* 168 */
2857 2, /* 176 */
2858 2, /* 184 */
2859 2 /* 192 */
2862 static inline int size_index_elem(size_t bytes)
2864 return (bytes - 1) / 8;
2867 static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2869 int index;
2871 if (size <= 192) {
2872 if (!size)
2873 return ZERO_SIZE_PTR;
2875 index = size_index[size_index_elem(size)];
2876 } else
2877 index = fls(size - 1);
2879 #ifdef CONFIG_ZONE_DMA
2880 if (unlikely((flags & SLUB_DMA)))
2881 return kmalloc_dma_caches[index];
2883 #endif
2884 return kmalloc_caches[index];
2887 void *__kmalloc(size_t size, gfp_t flags)
2889 struct kmem_cache *s;
2890 void *ret;
2892 if (unlikely(size > SLUB_MAX_SIZE))
2893 return kmalloc_large(size, flags);
2895 s = get_slab(size, flags);
2897 if (unlikely(ZERO_OR_NULL_PTR(s)))
2898 return s;
2900 ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_);
2902 trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
2904 return ret;
2906 EXPORT_SYMBOL(__kmalloc);
2908 #ifdef CONFIG_NUMA
2909 static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
2911 struct page *page;
2912 void *ptr = NULL;
2914 flags |= __GFP_COMP | __GFP_NOTRACK;
2915 page = alloc_pages_node(node, flags, get_order(size));
2916 if (page)
2917 ptr = page_address(page);
2919 kmemleak_alloc(ptr, size, 1, flags);
2920 return ptr;
2923 void *__kmalloc_node(size_t size, gfp_t flags, int node)
2925 struct kmem_cache *s;
2926 void *ret;
2928 if (unlikely(size > SLUB_MAX_SIZE)) {
2929 ret = kmalloc_large_node(size, flags, node);
2931 trace_kmalloc_node(_RET_IP_, ret,
2932 size, PAGE_SIZE << get_order(size),
2933 flags, node);
2935 return ret;
2938 s = get_slab(size, flags);
2940 if (unlikely(ZERO_OR_NULL_PTR(s)))
2941 return s;
2943 ret = slab_alloc(s, flags, node, _RET_IP_);
2945 trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
2947 return ret;
2949 EXPORT_SYMBOL(__kmalloc_node);
2950 #endif
2952 size_t ksize(const void *object)
2954 struct page *page;
2956 if (unlikely(object == ZERO_SIZE_PTR))
2957 return 0;
2959 page = virt_to_head_page(object);
2961 if (unlikely(!PageSlab(page))) {
2962 WARN_ON(!PageCompound(page));
2963 return PAGE_SIZE << compound_order(page);
2966 return slab_ksize(page->slab);
2968 EXPORT_SYMBOL(ksize);
2970 void kfree(const void *x)
2972 struct page *page;
2973 void *object = (void *)x;
2975 trace_kfree(_RET_IP_, x);
2977 if (unlikely(ZERO_OR_NULL_PTR(x)))
2978 return;
2980 page = virt_to_head_page(x);
2981 if (unlikely(!PageSlab(page))) {
2982 BUG_ON(!PageCompound(page));
2983 kmemleak_free(x);
2984 put_page(page);
2985 return;
2987 slab_free(page->slab, page, object, _RET_IP_);
2989 EXPORT_SYMBOL(kfree);
2992 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2993 * the remaining slabs by the number of items in use. The slabs with the
2994 * most items in use come first. New allocations will then fill those up
2995 * and thus they can be removed from the partial lists.
2997 * The slabs with the least items are placed last. This results in them
2998 * being allocated from last increasing the chance that the last objects
2999 * are freed in them.
3001 int kmem_cache_shrink(struct kmem_cache *s)
3003 int node;
3004 int i;
3005 struct kmem_cache_node *n;
3006 struct page *page;
3007 struct page *t;
3008 int objects = oo_objects(s->max);
3009 struct list_head *slabs_by_inuse =
3010 kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
3011 unsigned long flags;
3013 if (!slabs_by_inuse)
3014 return -ENOMEM;
3016 flush_all(s);
3017 for_each_node_state(node, N_NORMAL_MEMORY) {
3018 n = get_node(s, node);
3020 if (!n->nr_partial)
3021 continue;
3023 for (i = 0; i < objects; i++)
3024 INIT_LIST_HEAD(slabs_by_inuse + i);
3026 spin_lock_irqsave(&n->list_lock, flags);
3029 * Build lists indexed by the items in use in each slab.
3031 * Note that concurrent frees may occur while we hold the
3032 * list_lock. page->inuse here is the upper limit.
3034 list_for_each_entry_safe(page, t, &n->partial, lru) {
3035 if (!page->inuse && slab_trylock(page)) {
3037 * Must hold slab lock here because slab_free
3038 * may have freed the last object and be
3039 * waiting to release the slab.
3041 __remove_partial(n, page);
3042 slab_unlock(page);
3043 discard_slab(s, page);
3044 } else {
3045 list_move(&page->lru,
3046 slabs_by_inuse + page->inuse);
3051 * Rebuild the partial list with the slabs filled up most
3052 * first and the least used slabs at the end.
3054 for (i = objects - 1; i >= 0; i--)
3055 list_splice(slabs_by_inuse + i, n->partial.prev);
3057 spin_unlock_irqrestore(&n->list_lock, flags);
3060 kfree(slabs_by_inuse);
3061 return 0;
3063 EXPORT_SYMBOL(kmem_cache_shrink);
3065 #if defined(CONFIG_MEMORY_HOTPLUG)
3066 static int slab_mem_going_offline_callback(void *arg)
3068 struct kmem_cache *s;
3070 down_read(&slub_lock);
3071 list_for_each_entry(s, &slab_caches, list)
3072 kmem_cache_shrink(s);
3073 up_read(&slub_lock);
3075 return 0;
3078 static void slab_mem_offline_callback(void *arg)
3080 struct kmem_cache_node *n;
3081 struct kmem_cache *s;
3082 struct memory_notify *marg = arg;
3083 int offline_node;
3085 offline_node = marg->status_change_nid;
3088 * If the node still has available memory. we need kmem_cache_node
3089 * for it yet.
3091 if (offline_node < 0)
3092 return;
3094 down_read(&slub_lock);
3095 list_for_each_entry(s, &slab_caches, list) {
3096 n = get_node(s, offline_node);
3097 if (n) {
3099 * if n->nr_slabs > 0, slabs still exist on the node
3100 * that is going down. We were unable to free them,
3101 * and offline_pages() function shouldn't call this
3102 * callback. So, we must fail.
3104 BUG_ON(slabs_node(s, offline_node));
3106 s->node[offline_node] = NULL;
3107 kmem_cache_free(kmem_cache_node, n);
3110 up_read(&slub_lock);
3113 static int slab_mem_going_online_callback(void *arg)
3115 struct kmem_cache_node *n;
3116 struct kmem_cache *s;
3117 struct memory_notify *marg = arg;
3118 int nid = marg->status_change_nid;
3119 int ret = 0;
3122 * If the node's memory is already available, then kmem_cache_node is
3123 * already created. Nothing to do.
3125 if (nid < 0)
3126 return 0;
3129 * We are bringing a node online. No memory is available yet. We must
3130 * allocate a kmem_cache_node structure in order to bring the node
3131 * online.
3133 down_read(&slub_lock);
3134 list_for_each_entry(s, &slab_caches, list) {
3136 * XXX: kmem_cache_alloc_node will fallback to other nodes
3137 * since memory is not yet available from the node that
3138 * is brought up.
3140 n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
3141 if (!n) {
3142 ret = -ENOMEM;
3143 goto out;
3145 init_kmem_cache_node(n, s);
3146 s->node[nid] = n;
3148 out:
3149 up_read(&slub_lock);
3150 return ret;
3153 static int slab_memory_callback(struct notifier_block *self,
3154 unsigned long action, void *arg)
3156 int ret = 0;
3158 switch (action) {
3159 case MEM_GOING_ONLINE:
3160 ret = slab_mem_going_online_callback(arg);
3161 break;
3162 case MEM_GOING_OFFLINE:
3163 ret = slab_mem_going_offline_callback(arg);
3164 break;
3165 case MEM_OFFLINE:
3166 case MEM_CANCEL_ONLINE:
3167 slab_mem_offline_callback(arg);
3168 break;
3169 case MEM_ONLINE:
3170 case MEM_CANCEL_OFFLINE:
3171 break;
3173 if (ret)
3174 ret = notifier_from_errno(ret);
3175 else
3176 ret = NOTIFY_OK;
3177 return ret;
3180 #endif /* CONFIG_MEMORY_HOTPLUG */
3182 /********************************************************************
3183 * Basic setup of slabs
3184 *******************************************************************/
3187 * Used for early kmem_cache structures that were allocated using
3188 * the page allocator
3191 static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)
3193 int node;
3195 list_add(&s->list, &slab_caches);
3196 s->refcount = -1;
3198 for_each_node_state(node, N_NORMAL_MEMORY) {
3199 struct kmem_cache_node *n = get_node(s, node);
3200 struct page *p;
3202 if (n) {
3203 list_for_each_entry(p, &n->partial, lru)
3204 p->slab = s;
3206 #ifdef CONFIG_SLAB_DEBUG
3207 list_for_each_entry(p, &n->full, lru)
3208 p->slab = s;
3209 #endif
3214 void __init kmem_cache_init(void)
3216 int i;
3217 int caches = 0;
3218 struct kmem_cache *temp_kmem_cache;
3219 int order;
3220 struct kmem_cache *temp_kmem_cache_node;
3221 unsigned long kmalloc_size;
3223 kmem_size = offsetof(struct kmem_cache, node) +
3224 nr_node_ids * sizeof(struct kmem_cache_node *);
3226 /* Allocate two kmem_caches from the page allocator */
3227 kmalloc_size = ALIGN(kmem_size, cache_line_size());
3228 order = get_order(2 * kmalloc_size);
3229 kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order);
3232 * Must first have the slab cache available for the allocations of the
3233 * struct kmem_cache_node's. There is special bootstrap code in
3234 * kmem_cache_open for slab_state == DOWN.
3236 kmem_cache_node = (void *)kmem_cache + kmalloc_size;
3238 kmem_cache_open(kmem_cache_node, "kmem_cache_node",
3239 sizeof(struct kmem_cache_node),
3240 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
3242 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
3244 /* Able to allocate the per node structures */
3245 slab_state = PARTIAL;
3247 temp_kmem_cache = kmem_cache;
3248 kmem_cache_open(kmem_cache, "kmem_cache", kmem_size,
3249 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
3250 kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
3251 memcpy(kmem_cache, temp_kmem_cache, kmem_size);
3254 * Allocate kmem_cache_node properly from the kmem_cache slab.
3255 * kmem_cache_node is separately allocated so no need to
3256 * update any list pointers.
3258 temp_kmem_cache_node = kmem_cache_node;
3260 kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
3261 memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size);
3263 kmem_cache_bootstrap_fixup(kmem_cache_node);
3265 caches++;
3266 kmem_cache_bootstrap_fixup(kmem_cache);
3267 caches++;
3268 /* Free temporary boot structure */
3269 free_pages((unsigned long)temp_kmem_cache, order);
3271 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3274 * Patch up the size_index table if we have strange large alignment
3275 * requirements for the kmalloc array. This is only the case for
3276 * MIPS it seems. The standard arches will not generate any code here.
3278 * Largest permitted alignment is 256 bytes due to the way we
3279 * handle the index determination for the smaller caches.
3281 * Make sure that nothing crazy happens if someone starts tinkering
3282 * around with ARCH_KMALLOC_MINALIGN
3284 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
3285 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
3287 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
3288 int elem = size_index_elem(i);
3289 if (elem >= ARRAY_SIZE(size_index))
3290 break;
3291 size_index[elem] = KMALLOC_SHIFT_LOW;
3294 if (KMALLOC_MIN_SIZE == 64) {
3296 * The 96 byte size cache is not used if the alignment
3297 * is 64 byte.
3299 for (i = 64 + 8; i <= 96; i += 8)
3300 size_index[size_index_elem(i)] = 7;
3301 } else if (KMALLOC_MIN_SIZE == 128) {
3303 * The 192 byte sized cache is not used if the alignment
3304 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3305 * instead.
3307 for (i = 128 + 8; i <= 192; i += 8)
3308 size_index[size_index_elem(i)] = 8;
3311 /* Caches that are not of the two-to-the-power-of size */
3312 if (KMALLOC_MIN_SIZE <= 32) {
3313 kmalloc_caches[1] = create_kmalloc_cache("kmalloc-96", 96, 0);
3314 caches++;
3317 if (KMALLOC_MIN_SIZE <= 64) {
3318 kmalloc_caches[2] = create_kmalloc_cache("kmalloc-192", 192, 0);
3319 caches++;
3322 for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
3323 kmalloc_caches[i] = create_kmalloc_cache("kmalloc", 1 << i, 0);
3324 caches++;
3327 slab_state = UP;
3329 /* Provide the correct kmalloc names now that the caches are up */
3330 if (KMALLOC_MIN_SIZE <= 32) {
3331 kmalloc_caches[1]->name = kstrdup(kmalloc_caches[1]->name, GFP_NOWAIT);
3332 BUG_ON(!kmalloc_caches[1]->name);
3335 if (KMALLOC_MIN_SIZE <= 64) {
3336 kmalloc_caches[2]->name = kstrdup(kmalloc_caches[2]->name, GFP_NOWAIT);
3337 BUG_ON(!kmalloc_caches[2]->name);
3340 for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
3341 char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i);
3343 BUG_ON(!s);
3344 kmalloc_caches[i]->name = s;
3347 #ifdef CONFIG_SMP
3348 register_cpu_notifier(&slab_notifier);
3349 #endif
3351 #ifdef CONFIG_ZONE_DMA
3352 for (i = 0; i < SLUB_PAGE_SHIFT; i++) {
3353 struct kmem_cache *s = kmalloc_caches[i];
3355 if (s && s->size) {
3356 char *name = kasprintf(GFP_NOWAIT,
3357 "dma-kmalloc-%d", s->objsize);
3359 BUG_ON(!name);
3360 kmalloc_dma_caches[i] = create_kmalloc_cache(name,
3361 s->objsize, SLAB_CACHE_DMA);
3364 #endif
3365 printk(KERN_INFO
3366 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3367 " CPUs=%d, Nodes=%d\n",
3368 caches, cache_line_size(),
3369 slub_min_order, slub_max_order, slub_min_objects,
3370 nr_cpu_ids, nr_node_ids);
3373 void __init kmem_cache_init_late(void)
3378 * Find a mergeable slab cache
3380 static int slab_unmergeable(struct kmem_cache *s)
3382 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
3383 return 1;
3385 if (s->ctor)
3386 return 1;
3389 * We may have set a slab to be unmergeable during bootstrap.
3391 if (s->refcount < 0)
3392 return 1;
3394 return 0;
3397 static struct kmem_cache *find_mergeable(size_t size,
3398 size_t align, unsigned long flags, const char *name,
3399 void (*ctor)(void *))
3401 struct kmem_cache *s;
3403 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
3404 return NULL;
3406 if (ctor)
3407 return NULL;
3409 size = ALIGN(size, sizeof(void *));
3410 align = calculate_alignment(flags, align, size);
3411 size = ALIGN(size, align);
3412 flags = kmem_cache_flags(size, flags, name, NULL);
3414 list_for_each_entry(s, &slab_caches, list) {
3415 if (slab_unmergeable(s))
3416 continue;
3418 if (size > s->size)
3419 continue;
3421 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
3422 continue;
3424 * Check if alignment is compatible.
3425 * Courtesy of Adrian Drzewiecki
3427 if ((s->size & ~(align - 1)) != s->size)
3428 continue;
3430 if (s->size - size >= sizeof(void *))
3431 continue;
3433 return s;
3435 return NULL;
3438 struct kmem_cache *kmem_cache_create(const char *name, size_t size,
3439 size_t align, unsigned long flags, void (*ctor)(void *))
3441 struct kmem_cache *s;
3442 char *n;
3444 if (WARN_ON(!name))
3445 return NULL;
3447 down_write(&slub_lock);
3448 s = find_mergeable(size, align, flags, name, ctor);
3449 if (s) {
3450 s->refcount++;
3452 * Adjust the object sizes so that we clear
3453 * the complete object on kzalloc.
3455 s->objsize = max(s->objsize, (int)size);
3456 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
3458 if (sysfs_slab_alias(s, name)) {
3459 s->refcount--;
3460 goto err;
3462 up_write(&slub_lock);
3463 return s;
3466 n = kstrdup(name, GFP_KERNEL);
3467 if (!n)
3468 goto err;
3470 s = kmalloc(kmem_size, GFP_KERNEL);
3471 if (s) {
3472 if (kmem_cache_open(s, n,
3473 size, align, flags, ctor)) {
3474 list_add(&s->list, &slab_caches);
3475 if (sysfs_slab_add(s)) {
3476 list_del(&s->list);
3477 kfree(n);
3478 kfree(s);
3479 goto err;
3481 up_write(&slub_lock);
3482 return s;
3484 kfree(n);
3485 kfree(s);
3487 err:
3488 up_write(&slub_lock);
3490 if (flags & SLAB_PANIC)
3491 panic("Cannot create slabcache %s\n", name);
3492 else
3493 s = NULL;
3494 return s;
3496 EXPORT_SYMBOL(kmem_cache_create);
3498 #ifdef CONFIG_SMP
3500 * Use the cpu notifier to insure that the cpu slabs are flushed when
3501 * necessary.
3503 static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3504 unsigned long action, void *hcpu)
3506 long cpu = (long)hcpu;
3507 struct kmem_cache *s;
3508 unsigned long flags;
3510 switch (action) {
3511 case CPU_UP_CANCELED:
3512 case CPU_UP_CANCELED_FROZEN:
3513 case CPU_DEAD:
3514 case CPU_DEAD_FROZEN:
3515 down_read(&slub_lock);
3516 list_for_each_entry(s, &slab_caches, list) {
3517 local_irq_save(flags);
3518 __flush_cpu_slab(s, cpu);
3519 local_irq_restore(flags);
3521 up_read(&slub_lock);
3522 break;
3523 default:
3524 break;
3526 return NOTIFY_OK;
3529 static struct notifier_block __cpuinitdata slab_notifier = {
3530 .notifier_call = slab_cpuup_callback
3533 #endif
3535 void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
3537 struct kmem_cache *s;
3538 void *ret;
3540 if (unlikely(size > SLUB_MAX_SIZE))
3541 return kmalloc_large(size, gfpflags);
3543 s = get_slab(size, gfpflags);
3545 if (unlikely(ZERO_OR_NULL_PTR(s)))
3546 return s;
3548 ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller);
3550 /* Honor the call site pointer we recieved. */
3551 trace_kmalloc(caller, ret, size, s->size, gfpflags);
3553 return ret;
3556 #ifdef CONFIG_NUMA
3557 void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3558 int node, unsigned long caller)
3560 struct kmem_cache *s;
3561 void *ret;
3563 if (unlikely(size > SLUB_MAX_SIZE)) {
3564 ret = kmalloc_large_node(size, gfpflags, node);
3566 trace_kmalloc_node(caller, ret,
3567 size, PAGE_SIZE << get_order(size),
3568 gfpflags, node);
3570 return ret;
3573 s = get_slab(size, gfpflags);
3575 if (unlikely(ZERO_OR_NULL_PTR(s)))
3576 return s;
3578 ret = slab_alloc(s, gfpflags, node, caller);
3580 /* Honor the call site pointer we recieved. */
3581 trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
3583 return ret;
3585 #endif
3587 #ifdef CONFIG_SYSFS
3588 static int count_inuse(struct page *page)
3590 return page->inuse;
3593 static int count_total(struct page *page)
3595 return page->objects;
3597 #endif
3599 #ifdef CONFIG_SLUB_DEBUG
3600 static int validate_slab(struct kmem_cache *s, struct page *page,
3601 unsigned long *map)
3603 void *p;
3604 void *addr = page_address(page);
3606 if (!check_slab(s, page) ||
3607 !on_freelist(s, page, NULL))
3608 return 0;
3610 /* Now we know that a valid freelist exists */
3611 bitmap_zero(map, page->objects);
3613 for_each_free_object(p, s, page->freelist) {
3614 set_bit(slab_index(p, s, addr), map);
3615 if (!check_object(s, page, p, SLUB_RED_INACTIVE))
3616 return 0;
3619 for_each_object(p, s, addr, page->objects)
3620 if (!test_bit(slab_index(p, s, addr), map))
3621 if (!check_object(s, page, p, SLUB_RED_ACTIVE))
3622 return 0;
3623 return 1;
3626 static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3627 unsigned long *map)
3629 if (slab_trylock(page)) {
3630 validate_slab(s, page, map);
3631 slab_unlock(page);
3632 } else
3633 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3634 s->name, page);
3637 static int validate_slab_node(struct kmem_cache *s,
3638 struct kmem_cache_node *n, unsigned long *map)
3640 unsigned long count = 0;
3641 struct page *page;
3642 unsigned long flags;
3644 spin_lock_irqsave(&n->list_lock, flags);
3646 list_for_each_entry(page, &n->partial, lru) {
3647 validate_slab_slab(s, page, map);
3648 count++;
3650 if (count != n->nr_partial)
3651 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3652 "counter=%ld\n", s->name, count, n->nr_partial);
3654 if (!(s->flags & SLAB_STORE_USER))
3655 goto out;
3657 list_for_each_entry(page, &n->full, lru) {
3658 validate_slab_slab(s, page, map);
3659 count++;
3661 if (count != atomic_long_read(&n->nr_slabs))
3662 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3663 "counter=%ld\n", s->name, count,
3664 atomic_long_read(&n->nr_slabs));
3666 out:
3667 spin_unlock_irqrestore(&n->list_lock, flags);
3668 return count;
3671 static long validate_slab_cache(struct kmem_cache *s)
3673 int node;
3674 unsigned long count = 0;
3675 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
3676 sizeof(unsigned long), GFP_KERNEL);
3678 if (!map)
3679 return -ENOMEM;
3681 flush_all(s);
3682 for_each_node_state(node, N_NORMAL_MEMORY) {
3683 struct kmem_cache_node *n = get_node(s, node);
3685 count += validate_slab_node(s, n, map);
3687 kfree(map);
3688 return count;
3691 * Generate lists of code addresses where slabcache objects are allocated
3692 * and freed.
3695 struct location {
3696 unsigned long count;
3697 unsigned long addr;
3698 long long sum_time;
3699 long min_time;
3700 long max_time;
3701 long min_pid;
3702 long max_pid;
3703 DECLARE_BITMAP(cpus, NR_CPUS);
3704 nodemask_t nodes;
3707 struct loc_track {
3708 unsigned long max;
3709 unsigned long count;
3710 struct location *loc;
3713 static void free_loc_track(struct loc_track *t)
3715 if (t->max)
3716 free_pages((unsigned long)t->loc,
3717 get_order(sizeof(struct location) * t->max));
3720 static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
3722 struct location *l;
3723 int order;
3725 order = get_order(sizeof(struct location) * max);
3727 l = (void *)__get_free_pages(flags, order);
3728 if (!l)
3729 return 0;
3731 if (t->count) {
3732 memcpy(l, t->loc, sizeof(struct location) * t->count);
3733 free_loc_track(t);
3735 t->max = max;
3736 t->loc = l;
3737 return 1;
3740 static int add_location(struct loc_track *t, struct kmem_cache *s,
3741 const struct track *track)
3743 long start, end, pos;
3744 struct location *l;
3745 unsigned long caddr;
3746 unsigned long age = jiffies - track->when;
3748 start = -1;
3749 end = t->count;
3751 for ( ; ; ) {
3752 pos = start + (end - start + 1) / 2;
3755 * There is nothing at "end". If we end up there
3756 * we need to add something to before end.
3758 if (pos == end)
3759 break;
3761 caddr = t->loc[pos].addr;
3762 if (track->addr == caddr) {
3764 l = &t->loc[pos];
3765 l->count++;
3766 if (track->when) {
3767 l->sum_time += age;
3768 if (age < l->min_time)
3769 l->min_time = age;
3770 if (age > l->max_time)
3771 l->max_time = age;
3773 if (track->pid < l->min_pid)
3774 l->min_pid = track->pid;
3775 if (track->pid > l->max_pid)
3776 l->max_pid = track->pid;
3778 cpumask_set_cpu(track->cpu,
3779 to_cpumask(l->cpus));
3781 node_set(page_to_nid(virt_to_page(track)), l->nodes);
3782 return 1;
3785 if (track->addr < caddr)
3786 end = pos;
3787 else
3788 start = pos;
3792 * Not found. Insert new tracking element.
3794 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
3795 return 0;
3797 l = t->loc + pos;
3798 if (pos < t->count)
3799 memmove(l + 1, l,
3800 (t->count - pos) * sizeof(struct location));
3801 t->count++;
3802 l->count = 1;
3803 l->addr = track->addr;
3804 l->sum_time = age;
3805 l->min_time = age;
3806 l->max_time = age;
3807 l->min_pid = track->pid;
3808 l->max_pid = track->pid;
3809 cpumask_clear(to_cpumask(l->cpus));
3810 cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
3811 nodes_clear(l->nodes);
3812 node_set(page_to_nid(virt_to_page(track)), l->nodes);
3813 return 1;
3816 static void process_slab(struct loc_track *t, struct kmem_cache *s,
3817 struct page *page, enum track_item alloc,
3818 unsigned long *map)
3820 void *addr = page_address(page);
3821 void *p;
3823 bitmap_zero(map, page->objects);
3824 for_each_free_object(p, s, page->freelist)
3825 set_bit(slab_index(p, s, addr), map);
3827 for_each_object(p, s, addr, page->objects)
3828 if (!test_bit(slab_index(p, s, addr), map))
3829 add_location(t, s, get_track(s, p, alloc));
3832 static int list_locations(struct kmem_cache *s, char *buf,
3833 enum track_item alloc)
3835 int len = 0;
3836 unsigned long i;
3837 struct loc_track t = { 0, 0, NULL };
3838 int node;
3839 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
3840 sizeof(unsigned long), GFP_KERNEL);
3842 if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
3843 GFP_TEMPORARY)) {
3844 kfree(map);
3845 return sprintf(buf, "Out of memory\n");
3847 /* Push back cpu slabs */
3848 flush_all(s);
3850 for_each_node_state(node, N_NORMAL_MEMORY) {
3851 struct kmem_cache_node *n = get_node(s, node);
3852 unsigned long flags;
3853 struct page *page;
3855 if (!atomic_long_read(&n->nr_slabs))
3856 continue;
3858 spin_lock_irqsave(&n->list_lock, flags);
3859 list_for_each_entry(page, &n->partial, lru)
3860 process_slab(&t, s, page, alloc, map);
3861 list_for_each_entry(page, &n->full, lru)
3862 process_slab(&t, s, page, alloc, map);
3863 spin_unlock_irqrestore(&n->list_lock, flags);
3866 for (i = 0; i < t.count; i++) {
3867 struct location *l = &t.loc[i];
3869 if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100)
3870 break;
3871 len += sprintf(buf + len, "%7ld ", l->count);
3873 if (l->addr)
3874 len += sprintf(buf + len, "%pS", (void *)l->addr);
3875 else
3876 len += sprintf(buf + len, "<not-available>");
3878 if (l->sum_time != l->min_time) {
3879 len += sprintf(buf + len, " age=%ld/%ld/%ld",
3880 l->min_time,
3881 (long)div_u64(l->sum_time, l->count),
3882 l->max_time);
3883 } else
3884 len += sprintf(buf + len, " age=%ld",
3885 l->min_time);
3887 if (l->min_pid != l->max_pid)
3888 len += sprintf(buf + len, " pid=%ld-%ld",
3889 l->min_pid, l->max_pid);
3890 else
3891 len += sprintf(buf + len, " pid=%ld",
3892 l->min_pid);
3894 if (num_online_cpus() > 1 &&
3895 !cpumask_empty(to_cpumask(l->cpus)) &&
3896 len < PAGE_SIZE - 60) {
3897 len += sprintf(buf + len, " cpus=");
3898 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
3899 to_cpumask(l->cpus));
3902 if (nr_online_nodes > 1 && !nodes_empty(l->nodes) &&
3903 len < PAGE_SIZE - 60) {
3904 len += sprintf(buf + len, " nodes=");
3905 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
3906 l->nodes);
3909 len += sprintf(buf + len, "\n");
3912 free_loc_track(&t);
3913 kfree(map);
3914 if (!t.count)
3915 len += sprintf(buf, "No data\n");
3916 return len;
3918 #endif
3920 #ifdef SLUB_RESILIENCY_TEST
3921 static void resiliency_test(void)
3923 u8 *p;
3925 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || SLUB_PAGE_SHIFT < 10);
3927 printk(KERN_ERR "SLUB resiliency testing\n");
3928 printk(KERN_ERR "-----------------------\n");
3929 printk(KERN_ERR "A. Corruption after allocation\n");
3931 p = kzalloc(16, GFP_KERNEL);
3932 p[16] = 0x12;
3933 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3934 " 0x12->0x%p\n\n", p + 16);
3936 validate_slab_cache(kmalloc_caches[4]);
3938 /* Hmmm... The next two are dangerous */
3939 p = kzalloc(32, GFP_KERNEL);
3940 p[32 + sizeof(void *)] = 0x34;
3941 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
3942 " 0x34 -> -0x%p\n", p);
3943 printk(KERN_ERR
3944 "If allocated object is overwritten then not detectable\n\n");
3946 validate_slab_cache(kmalloc_caches[5]);
3947 p = kzalloc(64, GFP_KERNEL);
3948 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3949 *p = 0x56;
3950 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3952 printk(KERN_ERR
3953 "If allocated object is overwritten then not detectable\n\n");
3954 validate_slab_cache(kmalloc_caches[6]);
3956 printk(KERN_ERR "\nB. Corruption after free\n");
3957 p = kzalloc(128, GFP_KERNEL);
3958 kfree(p);
3959 *p = 0x78;
3960 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3961 validate_slab_cache(kmalloc_caches[7]);
3963 p = kzalloc(256, GFP_KERNEL);
3964 kfree(p);
3965 p[50] = 0x9a;
3966 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3968 validate_slab_cache(kmalloc_caches[8]);
3970 p = kzalloc(512, GFP_KERNEL);
3971 kfree(p);
3972 p[512] = 0xab;
3973 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3974 validate_slab_cache(kmalloc_caches[9]);
3976 #else
3977 #ifdef CONFIG_SYSFS
3978 static void resiliency_test(void) {};
3979 #endif
3980 #endif
3982 #ifdef CONFIG_SYSFS
3983 enum slab_stat_type {
3984 SL_ALL, /* All slabs */
3985 SL_PARTIAL, /* Only partially allocated slabs */
3986 SL_CPU, /* Only slabs used for cpu caches */
3987 SL_OBJECTS, /* Determine allocated objects not slabs */
3988 SL_TOTAL /* Determine object capacity not slabs */
3991 #define SO_ALL (1 << SL_ALL)
3992 #define SO_PARTIAL (1 << SL_PARTIAL)
3993 #define SO_CPU (1 << SL_CPU)
3994 #define SO_OBJECTS (1 << SL_OBJECTS)
3995 #define SO_TOTAL (1 << SL_TOTAL)
3997 static ssize_t show_slab_objects(struct kmem_cache *s,
3998 char *buf, unsigned long flags)
4000 unsigned long total = 0;
4001 int node;
4002 int x;
4003 unsigned long *nodes;
4004 unsigned long *per_cpu;
4006 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
4007 if (!nodes)
4008 return -ENOMEM;
4009 per_cpu = nodes + nr_node_ids;
4011 if (flags & SO_CPU) {
4012 int cpu;
4014 for_each_possible_cpu(cpu) {
4015 struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
4017 if (!c || c->node < 0)
4018 continue;
4020 if (c->page) {
4021 if (flags & SO_TOTAL)
4022 x = c->page->objects;
4023 else if (flags & SO_OBJECTS)
4024 x = c->page->inuse;
4025 else
4026 x = 1;
4028 total += x;
4029 nodes[c->node] += x;
4031 per_cpu[c->node]++;
4035 lock_memory_hotplug();
4036 #ifdef CONFIG_SLUB_DEBUG
4037 if (flags & SO_ALL) {
4038 for_each_node_state(node, N_NORMAL_MEMORY) {
4039 struct kmem_cache_node *n = get_node(s, node);
4041 if (flags & SO_TOTAL)
4042 x = atomic_long_read(&n->total_objects);
4043 else if (flags & SO_OBJECTS)
4044 x = atomic_long_read(&n->total_objects) -
4045 count_partial(n, count_free);
4047 else
4048 x = atomic_long_read(&n->nr_slabs);
4049 total += x;
4050 nodes[node] += x;
4053 } else
4054 #endif
4055 if (flags & SO_PARTIAL) {
4056 for_each_node_state(node, N_NORMAL_MEMORY) {
4057 struct kmem_cache_node *n = get_node(s, node);
4059 if (flags & SO_TOTAL)
4060 x = count_partial(n, count_total);
4061 else if (flags & SO_OBJECTS)
4062 x = count_partial(n, count_inuse);
4063 else
4064 x = n->nr_partial;
4065 total += x;
4066 nodes[node] += x;
4069 x = sprintf(buf, "%lu", total);
4070 #ifdef CONFIG_NUMA
4071 for_each_node_state(node, N_NORMAL_MEMORY)
4072 if (nodes[node])
4073 x += sprintf(buf + x, " N%d=%lu",
4074 node, nodes[node]);
4075 #endif
4076 unlock_memory_hotplug();
4077 kfree(nodes);
4078 return x + sprintf(buf + x, "\n");
4081 #ifdef CONFIG_SLUB_DEBUG
4082 static int any_slab_objects(struct kmem_cache *s)
4084 int node;
4086 for_each_online_node(node) {
4087 struct kmem_cache_node *n = get_node(s, node);
4089 if (!n)
4090 continue;
4092 if (atomic_long_read(&n->total_objects))
4093 return 1;
4095 return 0;
4097 #endif
4099 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4100 #define to_slab(n) container_of(n, struct kmem_cache, kobj);
4102 struct slab_attribute {
4103 struct attribute attr;
4104 ssize_t (*show)(struct kmem_cache *s, char *buf);
4105 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
4108 #define SLAB_ATTR_RO(_name) \
4109 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
4111 #define SLAB_ATTR(_name) \
4112 static struct slab_attribute _name##_attr = \
4113 __ATTR(_name, 0644, _name##_show, _name##_store)
4115 static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
4117 return sprintf(buf, "%d\n", s->size);
4119 SLAB_ATTR_RO(slab_size);
4121 static ssize_t align_show(struct kmem_cache *s, char *buf)
4123 return sprintf(buf, "%d\n", s->align);
4125 SLAB_ATTR_RO(align);
4127 static ssize_t object_size_show(struct kmem_cache *s, char *buf)
4129 return sprintf(buf, "%d\n", s->objsize);
4131 SLAB_ATTR_RO(object_size);
4133 static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
4135 return sprintf(buf, "%d\n", oo_objects(s->oo));
4137 SLAB_ATTR_RO(objs_per_slab);
4139 static ssize_t order_store(struct kmem_cache *s,
4140 const char *buf, size_t length)
4142 unsigned long order;
4143 int err;
4145 err = strict_strtoul(buf, 10, &order);
4146 if (err)
4147 return err;
4149 if (order > slub_max_order || order < slub_min_order)
4150 return -EINVAL;
4152 calculate_sizes(s, order);
4153 return length;
4156 static ssize_t order_show(struct kmem_cache *s, char *buf)
4158 return sprintf(buf, "%d\n", oo_order(s->oo));
4160 SLAB_ATTR(order);
4162 static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
4164 return sprintf(buf, "%lu\n", s->min_partial);
4167 static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
4168 size_t length)
4170 unsigned long min;
4171 int err;
4173 err = strict_strtoul(buf, 10, &min);
4174 if (err)
4175 return err;
4177 set_min_partial(s, min);
4178 return length;
4180 SLAB_ATTR(min_partial);
4182 static ssize_t ctor_show(struct kmem_cache *s, char *buf)
4184 if (!s->ctor)
4185 return 0;
4186 return sprintf(buf, "%pS\n", s->ctor);
4188 SLAB_ATTR_RO(ctor);
4190 static ssize_t aliases_show(struct kmem_cache *s, char *buf)
4192 return sprintf(buf, "%d\n", s->refcount - 1);
4194 SLAB_ATTR_RO(aliases);
4196 static ssize_t partial_show(struct kmem_cache *s, char *buf)
4198 return show_slab_objects(s, buf, SO_PARTIAL);
4200 SLAB_ATTR_RO(partial);
4202 static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
4204 return show_slab_objects(s, buf, SO_CPU);
4206 SLAB_ATTR_RO(cpu_slabs);
4208 static ssize_t objects_show(struct kmem_cache *s, char *buf)
4210 return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
4212 SLAB_ATTR_RO(objects);
4214 static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
4216 return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
4218 SLAB_ATTR_RO(objects_partial);
4220 static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
4222 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
4225 static ssize_t reclaim_account_store(struct kmem_cache *s,
4226 const char *buf, size_t length)
4228 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
4229 if (buf[0] == '1')
4230 s->flags |= SLAB_RECLAIM_ACCOUNT;
4231 return length;
4233 SLAB_ATTR(reclaim_account);
4235 static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
4237 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
4239 SLAB_ATTR_RO(hwcache_align);
4241 #ifdef CONFIG_ZONE_DMA
4242 static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
4244 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
4246 SLAB_ATTR_RO(cache_dma);
4247 #endif
4249 static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
4251 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
4253 SLAB_ATTR_RO(destroy_by_rcu);
4255 static ssize_t reserved_show(struct kmem_cache *s, char *buf)
4257 return sprintf(buf, "%d\n", s->reserved);
4259 SLAB_ATTR_RO(reserved);
4261 #ifdef CONFIG_SLUB_DEBUG
4262 static ssize_t slabs_show(struct kmem_cache *s, char *buf)
4264 return show_slab_objects(s, buf, SO_ALL);
4266 SLAB_ATTR_RO(slabs);
4268 static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
4270 return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
4272 SLAB_ATTR_RO(total_objects);
4274 static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
4276 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
4279 static ssize_t sanity_checks_store(struct kmem_cache *s,
4280 const char *buf, size_t length)
4282 s->flags &= ~SLAB_DEBUG_FREE;
4283 if (buf[0] == '1')
4284 s->flags |= SLAB_DEBUG_FREE;
4285 return length;
4287 SLAB_ATTR(sanity_checks);
4289 static ssize_t trace_show(struct kmem_cache *s, char *buf)
4291 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
4294 static ssize_t trace_store(struct kmem_cache *s, const char *buf,
4295 size_t length)
4297 s->flags &= ~SLAB_TRACE;
4298 if (buf[0] == '1')
4299 s->flags |= SLAB_TRACE;
4300 return length;
4302 SLAB_ATTR(trace);
4304 static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
4306 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
4309 static ssize_t red_zone_store(struct kmem_cache *s,
4310 const char *buf, size_t length)
4312 if (any_slab_objects(s))
4313 return -EBUSY;
4315 s->flags &= ~SLAB_RED_ZONE;
4316 if (buf[0] == '1')
4317 s->flags |= SLAB_RED_ZONE;
4318 calculate_sizes(s, -1);
4319 return length;
4321 SLAB_ATTR(red_zone);
4323 static ssize_t poison_show(struct kmem_cache *s, char *buf)
4325 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
4328 static ssize_t poison_store(struct kmem_cache *s,
4329 const char *buf, size_t length)
4331 if (any_slab_objects(s))
4332 return -EBUSY;
4334 s->flags &= ~SLAB_POISON;
4335 if (buf[0] == '1')
4336 s->flags |= SLAB_POISON;
4337 calculate_sizes(s, -1);
4338 return length;
4340 SLAB_ATTR(poison);
4342 static ssize_t store_user_show(struct kmem_cache *s, char *buf)
4344 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
4347 static ssize_t store_user_store(struct kmem_cache *s,
4348 const char *buf, size_t length)
4350 if (any_slab_objects(s))
4351 return -EBUSY;
4353 s->flags &= ~SLAB_STORE_USER;
4354 if (buf[0] == '1')
4355 s->flags |= SLAB_STORE_USER;
4356 calculate_sizes(s, -1);
4357 return length;
4359 SLAB_ATTR(store_user);
4361 static ssize_t validate_show(struct kmem_cache *s, char *buf)
4363 return 0;
4366 static ssize_t validate_store(struct kmem_cache *s,
4367 const char *buf, size_t length)
4369 int ret = -EINVAL;
4371 if (buf[0] == '1') {
4372 ret = validate_slab_cache(s);
4373 if (ret >= 0)
4374 ret = length;
4376 return ret;
4378 SLAB_ATTR(validate);
4380 static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
4382 if (!(s->flags & SLAB_STORE_USER))
4383 return -ENOSYS;
4384 return list_locations(s, buf, TRACK_ALLOC);
4386 SLAB_ATTR_RO(alloc_calls);
4388 static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
4390 if (!(s->flags & SLAB_STORE_USER))
4391 return -ENOSYS;
4392 return list_locations(s, buf, TRACK_FREE);
4394 SLAB_ATTR_RO(free_calls);
4395 #endif /* CONFIG_SLUB_DEBUG */
4397 #ifdef CONFIG_FAILSLAB
4398 static ssize_t failslab_show(struct kmem_cache *s, char *buf)
4400 return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
4403 static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
4404 size_t length)
4406 s->flags &= ~SLAB_FAILSLAB;
4407 if (buf[0] == '1')
4408 s->flags |= SLAB_FAILSLAB;
4409 return length;
4411 SLAB_ATTR(failslab);
4412 #endif
4414 static ssize_t shrink_show(struct kmem_cache *s, char *buf)
4416 return 0;
4419 static ssize_t shrink_store(struct kmem_cache *s,
4420 const char *buf, size_t length)
4422 if (buf[0] == '1') {
4423 int rc = kmem_cache_shrink(s);
4425 if (rc)
4426 return rc;
4427 } else
4428 return -EINVAL;
4429 return length;
4431 SLAB_ATTR(shrink);
4433 #ifdef CONFIG_NUMA
4434 static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
4436 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
4439 static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
4440 const char *buf, size_t length)
4442 unsigned long ratio;
4443 int err;
4445 err = strict_strtoul(buf, 10, &ratio);
4446 if (err)
4447 return err;
4449 if (ratio <= 100)
4450 s->remote_node_defrag_ratio = ratio * 10;
4452 return length;
4454 SLAB_ATTR(remote_node_defrag_ratio);
4455 #endif
4457 #ifdef CONFIG_SLUB_STATS
4458 static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
4460 unsigned long sum = 0;
4461 int cpu;
4462 int len;
4463 int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
4465 if (!data)
4466 return -ENOMEM;
4468 for_each_online_cpu(cpu) {
4469 unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
4471 data[cpu] = x;
4472 sum += x;
4475 len = sprintf(buf, "%lu", sum);
4477 #ifdef CONFIG_SMP
4478 for_each_online_cpu(cpu) {
4479 if (data[cpu] && len < PAGE_SIZE - 20)
4480 len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
4482 #endif
4483 kfree(data);
4484 return len + sprintf(buf + len, "\n");
4487 static void clear_stat(struct kmem_cache *s, enum stat_item si)
4489 int cpu;
4491 for_each_online_cpu(cpu)
4492 per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
4495 #define STAT_ATTR(si, text) \
4496 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4498 return show_stat(s, buf, si); \
4500 static ssize_t text##_store(struct kmem_cache *s, \
4501 const char *buf, size_t length) \
4503 if (buf[0] != '0') \
4504 return -EINVAL; \
4505 clear_stat(s, si); \
4506 return length; \
4508 SLAB_ATTR(text); \
4510 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4511 STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
4512 STAT_ATTR(FREE_FASTPATH, free_fastpath);
4513 STAT_ATTR(FREE_SLOWPATH, free_slowpath);
4514 STAT_ATTR(FREE_FROZEN, free_frozen);
4515 STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
4516 STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
4517 STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
4518 STAT_ATTR(ALLOC_SLAB, alloc_slab);
4519 STAT_ATTR(ALLOC_REFILL, alloc_refill);
4520 STAT_ATTR(FREE_SLAB, free_slab);
4521 STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
4522 STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
4523 STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
4524 STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
4525 STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
4526 STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
4527 STAT_ATTR(ORDER_FALLBACK, order_fallback);
4528 #endif
4530 static struct attribute *slab_attrs[] = {
4531 &slab_size_attr.attr,
4532 &object_size_attr.attr,
4533 &objs_per_slab_attr.attr,
4534 &order_attr.attr,
4535 &min_partial_attr.attr,
4536 &objects_attr.attr,
4537 &objects_partial_attr.attr,
4538 &partial_attr.attr,
4539 &cpu_slabs_attr.attr,
4540 &ctor_attr.attr,
4541 &aliases_attr.attr,
4542 &align_attr.attr,
4543 &hwcache_align_attr.attr,
4544 &reclaim_account_attr.attr,
4545 &destroy_by_rcu_attr.attr,
4546 &shrink_attr.attr,
4547 &reserved_attr.attr,
4548 #ifdef CONFIG_SLUB_DEBUG
4549 &total_objects_attr.attr,
4550 &slabs_attr.attr,
4551 &sanity_checks_attr.attr,
4552 &trace_attr.attr,
4553 &red_zone_attr.attr,
4554 &poison_attr.attr,
4555 &store_user_attr.attr,
4556 &validate_attr.attr,
4557 &alloc_calls_attr.attr,
4558 &free_calls_attr.attr,
4559 #endif
4560 #ifdef CONFIG_ZONE_DMA
4561 &cache_dma_attr.attr,
4562 #endif
4563 #ifdef CONFIG_NUMA
4564 &remote_node_defrag_ratio_attr.attr,
4565 #endif
4566 #ifdef CONFIG_SLUB_STATS
4567 &alloc_fastpath_attr.attr,
4568 &alloc_slowpath_attr.attr,
4569 &free_fastpath_attr.attr,
4570 &free_slowpath_attr.attr,
4571 &free_frozen_attr.attr,
4572 &free_add_partial_attr.attr,
4573 &free_remove_partial_attr.attr,
4574 &alloc_from_partial_attr.attr,
4575 &alloc_slab_attr.attr,
4576 &alloc_refill_attr.attr,
4577 &free_slab_attr.attr,
4578 &cpuslab_flush_attr.attr,
4579 &deactivate_full_attr.attr,
4580 &deactivate_empty_attr.attr,
4581 &deactivate_to_head_attr.attr,
4582 &deactivate_to_tail_attr.attr,
4583 &deactivate_remote_frees_attr.attr,
4584 &order_fallback_attr.attr,
4585 #endif
4586 #ifdef CONFIG_FAILSLAB
4587 &failslab_attr.attr,
4588 #endif
4590 NULL
4593 static struct attribute_group slab_attr_group = {
4594 .attrs = slab_attrs,
4597 static ssize_t slab_attr_show(struct kobject *kobj,
4598 struct attribute *attr,
4599 char *buf)
4601 struct slab_attribute *attribute;
4602 struct kmem_cache *s;
4603 int err;
4605 attribute = to_slab_attr(attr);
4606 s = to_slab(kobj);
4608 if (!attribute->show)
4609 return -EIO;
4611 err = attribute->show(s, buf);
4613 return err;
4616 static ssize_t slab_attr_store(struct kobject *kobj,
4617 struct attribute *attr,
4618 const char *buf, size_t len)
4620 struct slab_attribute *attribute;
4621 struct kmem_cache *s;
4622 int err;
4624 attribute = to_slab_attr(attr);
4625 s = to_slab(kobj);
4627 if (!attribute->store)
4628 return -EIO;
4630 err = attribute->store(s, buf, len);
4632 return err;
4635 static void kmem_cache_release(struct kobject *kobj)
4637 struct kmem_cache *s = to_slab(kobj);
4639 kfree(s->name);
4640 kfree(s);
4643 static const struct sysfs_ops slab_sysfs_ops = {
4644 .show = slab_attr_show,
4645 .store = slab_attr_store,
4648 static struct kobj_type slab_ktype = {
4649 .sysfs_ops = &slab_sysfs_ops,
4650 .release = kmem_cache_release
4653 static int uevent_filter(struct kset *kset, struct kobject *kobj)
4655 struct kobj_type *ktype = get_ktype(kobj);
4657 if (ktype == &slab_ktype)
4658 return 1;
4659 return 0;
4662 static const struct kset_uevent_ops slab_uevent_ops = {
4663 .filter = uevent_filter,
4666 static struct kset *slab_kset;
4668 #define ID_STR_LENGTH 64
4670 /* Create a unique string id for a slab cache:
4672 * Format :[flags-]size
4674 static char *create_unique_id(struct kmem_cache *s)
4676 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
4677 char *p = name;
4679 BUG_ON(!name);
4681 *p++ = ':';
4683 * First flags affecting slabcache operations. We will only
4684 * get here for aliasable slabs so we do not need to support
4685 * too many flags. The flags here must cover all flags that
4686 * are matched during merging to guarantee that the id is
4687 * unique.
4689 if (s->flags & SLAB_CACHE_DMA)
4690 *p++ = 'd';
4691 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4692 *p++ = 'a';
4693 if (s->flags & SLAB_DEBUG_FREE)
4694 *p++ = 'F';
4695 if (!(s->flags & SLAB_NOTRACK))
4696 *p++ = 't';
4697 if (p != name + 1)
4698 *p++ = '-';
4699 p += sprintf(p, "%07d", s->size);
4700 BUG_ON(p > name + ID_STR_LENGTH - 1);
4701 return name;
4704 static int sysfs_slab_add(struct kmem_cache *s)
4706 int err;
4707 const char *name;
4708 int unmergeable;
4710 if (slab_state < SYSFS)
4711 /* Defer until later */
4712 return 0;
4714 unmergeable = slab_unmergeable(s);
4715 if (unmergeable) {
4717 * Slabcache can never be merged so we can use the name proper.
4718 * This is typically the case for debug situations. In that
4719 * case we can catch duplicate names easily.
4721 sysfs_remove_link(&slab_kset->kobj, s->name);
4722 name = s->name;
4723 } else {
4725 * Create a unique name for the slab as a target
4726 * for the symlinks.
4728 name = create_unique_id(s);
4731 s->kobj.kset = slab_kset;
4732 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4733 if (err) {
4734 kobject_put(&s->kobj);
4735 return err;
4738 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4739 if (err) {
4740 kobject_del(&s->kobj);
4741 kobject_put(&s->kobj);
4742 return err;
4744 kobject_uevent(&s->kobj, KOBJ_ADD);
4745 if (!unmergeable) {
4746 /* Setup first alias */
4747 sysfs_slab_alias(s, s->name);
4748 kfree(name);
4750 return 0;
4753 static void sysfs_slab_remove(struct kmem_cache *s)
4755 if (slab_state < SYSFS)
4757 * Sysfs has not been setup yet so no need to remove the
4758 * cache from sysfs.
4760 return;
4762 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4763 kobject_del(&s->kobj);
4764 kobject_put(&s->kobj);
4768 * Need to buffer aliases during bootup until sysfs becomes
4769 * available lest we lose that information.
4771 struct saved_alias {
4772 struct kmem_cache *s;
4773 const char *name;
4774 struct saved_alias *next;
4777 static struct saved_alias *alias_list;
4779 static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4781 struct saved_alias *al;
4783 if (slab_state == SYSFS) {
4785 * If we have a leftover link then remove it.
4787 sysfs_remove_link(&slab_kset->kobj, name);
4788 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
4791 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4792 if (!al)
4793 return -ENOMEM;
4795 al->s = s;
4796 al->name = name;
4797 al->next = alias_list;
4798 alias_list = al;
4799 return 0;
4802 static int __init slab_sysfs_init(void)
4804 struct kmem_cache *s;
4805 int err;
4807 down_write(&slub_lock);
4809 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
4810 if (!slab_kset) {
4811 up_write(&slub_lock);
4812 printk(KERN_ERR "Cannot register slab subsystem.\n");
4813 return -ENOSYS;
4816 slab_state = SYSFS;
4818 list_for_each_entry(s, &slab_caches, list) {
4819 err = sysfs_slab_add(s);
4820 if (err)
4821 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4822 " to sysfs\n", s->name);
4825 while (alias_list) {
4826 struct saved_alias *al = alias_list;
4828 alias_list = alias_list->next;
4829 err = sysfs_slab_alias(al->s, al->name);
4830 if (err)
4831 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4832 " %s to sysfs\n", s->name);
4833 kfree(al);
4836 up_write(&slub_lock);
4837 resiliency_test();
4838 return 0;
4841 __initcall(slab_sysfs_init);
4842 #endif /* CONFIG_SYSFS */
4845 * The /proc/slabinfo ABI
4847 #ifdef CONFIG_SLABINFO
4848 static void print_slabinfo_header(struct seq_file *m)
4850 seq_puts(m, "slabinfo - version: 2.1\n");
4851 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4852 "<objperslab> <pagesperslab>");
4853 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4854 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4855 seq_putc(m, '\n');
4858 static void *s_start(struct seq_file *m, loff_t *pos)
4860 loff_t n = *pos;
4862 down_read(&slub_lock);
4863 if (!n)
4864 print_slabinfo_header(m);
4866 return seq_list_start(&slab_caches, *pos);
4869 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4871 return seq_list_next(p, &slab_caches, pos);
4874 static void s_stop(struct seq_file *m, void *p)
4876 up_read(&slub_lock);
4879 static int s_show(struct seq_file *m, void *p)
4881 unsigned long nr_partials = 0;
4882 unsigned long nr_slabs = 0;
4883 unsigned long nr_inuse = 0;
4884 unsigned long nr_objs = 0;
4885 unsigned long nr_free = 0;
4886 struct kmem_cache *s;
4887 int node;
4889 s = list_entry(p, struct kmem_cache, list);
4891 for_each_online_node(node) {
4892 struct kmem_cache_node *n = get_node(s, node);
4894 if (!n)
4895 continue;
4897 nr_partials += n->nr_partial;
4898 nr_slabs += atomic_long_read(&n->nr_slabs);
4899 nr_objs += atomic_long_read(&n->total_objects);
4900 nr_free += count_partial(n, count_free);
4903 nr_inuse = nr_objs - nr_free;
4905 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
4906 nr_objs, s->size, oo_objects(s->oo),
4907 (1 << oo_order(s->oo)));
4908 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4909 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4910 0UL);
4911 seq_putc(m, '\n');
4912 return 0;
4915 static const struct seq_operations slabinfo_op = {
4916 .start = s_start,
4917 .next = s_next,
4918 .stop = s_stop,
4919 .show = s_show,
4922 static int slabinfo_open(struct inode *inode, struct file *file)
4924 return seq_open(file, &slabinfo_op);
4927 static const struct file_operations proc_slabinfo_operations = {
4928 .open = slabinfo_open,
4929 .read = seq_read,
4930 .llseek = seq_lseek,
4931 .release = seq_release,
4934 static int __init slab_proc_init(void)
4936 proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
4937 return 0;
4939 module_init(slab_proc_init);
4940 #endif /* CONFIG_SLABINFO */