hwmon: (sht15) fix bad error code
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / mm / slub.c
blob35f351f26193a47145cd8bcb7f55ae091331ca97
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 no one 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 *get_freepointer_safe(struct kmem_cache *s, void *object)
266 void *p;
268 #ifdef CONFIG_DEBUG_PAGEALLOC
269 probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
270 #else
271 p = get_freepointer(s, object);
272 #endif
273 return p;
276 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
278 *(void **)(object + s->offset) = fp;
281 /* Loop over all objects in a slab */
282 #define for_each_object(__p, __s, __addr, __objects) \
283 for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
284 __p += (__s)->size)
286 /* Determine object index from a given position */
287 static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
289 return (p - addr) / s->size;
292 static inline size_t slab_ksize(const struct kmem_cache *s)
294 #ifdef CONFIG_SLUB_DEBUG
296 * Debugging requires use of the padding between object
297 * and whatever may come after it.
299 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
300 return s->objsize;
302 #endif
304 * If we have the need to store the freelist pointer
305 * back there or track user information then we can
306 * only use the space before that information.
308 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
309 return s->inuse;
311 * Else we can use all the padding etc for the allocation
313 return s->size;
316 static inline int order_objects(int order, unsigned long size, int reserved)
318 return ((PAGE_SIZE << order) - reserved) / size;
321 static inline struct kmem_cache_order_objects oo_make(int order,
322 unsigned long size, int reserved)
324 struct kmem_cache_order_objects x = {
325 (order << OO_SHIFT) + order_objects(order, size, reserved)
328 return x;
331 static inline int oo_order(struct kmem_cache_order_objects x)
333 return x.x >> OO_SHIFT;
336 static inline int oo_objects(struct kmem_cache_order_objects x)
338 return x.x & OO_MASK;
341 #ifdef CONFIG_SLUB_DEBUG
343 * Determine a map of object in use on a page.
345 * Slab lock or node listlock must be held to guarantee that the page does
346 * not vanish from under us.
348 static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
350 void *p;
351 void *addr = page_address(page);
353 for (p = page->freelist; p; p = get_freepointer(s, p))
354 set_bit(slab_index(p, s, addr), map);
358 * Debug settings:
360 #ifdef CONFIG_SLUB_DEBUG_ON
361 static int slub_debug = DEBUG_DEFAULT_FLAGS;
362 #else
363 static int slub_debug;
364 #endif
366 static char *slub_debug_slabs;
367 static int disable_higher_order_debug;
370 * Object debugging
372 static void print_section(char *text, u8 *addr, unsigned int length)
374 int i, offset;
375 int newline = 1;
376 char ascii[17];
378 ascii[16] = 0;
380 for (i = 0; i < length; i++) {
381 if (newline) {
382 printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
383 newline = 0;
385 printk(KERN_CONT " %02x", addr[i]);
386 offset = i % 16;
387 ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
388 if (offset == 15) {
389 printk(KERN_CONT " %s\n", ascii);
390 newline = 1;
393 if (!newline) {
394 i %= 16;
395 while (i < 16) {
396 printk(KERN_CONT " ");
397 ascii[i] = ' ';
398 i++;
400 printk(KERN_CONT " %s\n", ascii);
404 static struct track *get_track(struct kmem_cache *s, void *object,
405 enum track_item alloc)
407 struct track *p;
409 if (s->offset)
410 p = object + s->offset + sizeof(void *);
411 else
412 p = object + s->inuse;
414 return p + alloc;
417 static void set_track(struct kmem_cache *s, void *object,
418 enum track_item alloc, unsigned long addr)
420 struct track *p = get_track(s, object, alloc);
422 if (addr) {
423 p->addr = addr;
424 p->cpu = smp_processor_id();
425 p->pid = current->pid;
426 p->when = jiffies;
427 } else
428 memset(p, 0, sizeof(struct track));
431 static void init_tracking(struct kmem_cache *s, void *object)
433 if (!(s->flags & SLAB_STORE_USER))
434 return;
436 set_track(s, object, TRACK_FREE, 0UL);
437 set_track(s, object, TRACK_ALLOC, 0UL);
440 static void print_track(const char *s, struct track *t)
442 if (!t->addr)
443 return;
445 printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
446 s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid);
449 static void print_tracking(struct kmem_cache *s, void *object)
451 if (!(s->flags & SLAB_STORE_USER))
452 return;
454 print_track("Allocated", get_track(s, object, TRACK_ALLOC));
455 print_track("Freed", get_track(s, object, TRACK_FREE));
458 static void print_page_info(struct page *page)
460 printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
461 page, page->objects, page->inuse, page->freelist, page->flags);
465 static void slab_bug(struct kmem_cache *s, char *fmt, ...)
467 va_list args;
468 char buf[100];
470 va_start(args, fmt);
471 vsnprintf(buf, sizeof(buf), fmt, args);
472 va_end(args);
473 printk(KERN_ERR "========================================"
474 "=====================================\n");
475 printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
476 printk(KERN_ERR "----------------------------------------"
477 "-------------------------------------\n\n");
480 static void slab_fix(struct kmem_cache *s, char *fmt, ...)
482 va_list args;
483 char buf[100];
485 va_start(args, fmt);
486 vsnprintf(buf, sizeof(buf), fmt, args);
487 va_end(args);
488 printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
491 static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
493 unsigned int off; /* Offset of last byte */
494 u8 *addr = page_address(page);
496 print_tracking(s, p);
498 print_page_info(page);
500 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
501 p, p - addr, get_freepointer(s, p));
503 if (p > addr + 16)
504 print_section("Bytes b4", p - 16, 16);
506 print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE));
508 if (s->flags & SLAB_RED_ZONE)
509 print_section("Redzone", p + s->objsize,
510 s->inuse - s->objsize);
512 if (s->offset)
513 off = s->offset + sizeof(void *);
514 else
515 off = s->inuse;
517 if (s->flags & SLAB_STORE_USER)
518 off += 2 * sizeof(struct track);
520 if (off != s->size)
521 /* Beginning of the filler is the free pointer */
522 print_section("Padding", p + off, s->size - off);
524 dump_stack();
527 static void object_err(struct kmem_cache *s, struct page *page,
528 u8 *object, char *reason)
530 slab_bug(s, "%s", reason);
531 print_trailer(s, page, object);
534 static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
536 va_list args;
537 char buf[100];
539 va_start(args, fmt);
540 vsnprintf(buf, sizeof(buf), fmt, args);
541 va_end(args);
542 slab_bug(s, "%s", buf);
543 print_page_info(page);
544 dump_stack();
547 static void init_object(struct kmem_cache *s, void *object, u8 val)
549 u8 *p = object;
551 if (s->flags & __OBJECT_POISON) {
552 memset(p, POISON_FREE, s->objsize - 1);
553 p[s->objsize - 1] = POISON_END;
556 if (s->flags & SLAB_RED_ZONE)
557 memset(p + s->objsize, val, s->inuse - s->objsize);
560 static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes)
562 while (bytes) {
563 if (*start != (u8)value)
564 return start;
565 start++;
566 bytes--;
568 return NULL;
571 static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
572 void *from, void *to)
574 slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
575 memset(from, data, to - from);
578 static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
579 u8 *object, char *what,
580 u8 *start, unsigned int value, unsigned int bytes)
582 u8 *fault;
583 u8 *end;
585 fault = check_bytes(start, value, bytes);
586 if (!fault)
587 return 1;
589 end = start + bytes;
590 while (end > fault && end[-1] == value)
591 end--;
593 slab_bug(s, "%s overwritten", what);
594 printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
595 fault, end - 1, fault[0], value);
596 print_trailer(s, page, object);
598 restore_bytes(s, what, value, fault, end);
599 return 0;
603 * Object layout:
605 * object address
606 * Bytes of the object to be managed.
607 * If the freepointer may overlay the object then the free
608 * pointer is the first word of the object.
610 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
611 * 0xa5 (POISON_END)
613 * object + s->objsize
614 * Padding to reach word boundary. This is also used for Redzoning.
615 * Padding is extended by another word if Redzoning is enabled and
616 * objsize == inuse.
618 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
619 * 0xcc (RED_ACTIVE) for objects in use.
621 * object + s->inuse
622 * Meta data starts here.
624 * A. Free pointer (if we cannot overwrite object on free)
625 * B. Tracking data for SLAB_STORE_USER
626 * C. Padding to reach required alignment boundary or at mininum
627 * one word if debugging is on to be able to detect writes
628 * before the word boundary.
630 * Padding is done using 0x5a (POISON_INUSE)
632 * object + s->size
633 * Nothing is used beyond s->size.
635 * If slabcaches are merged then the objsize and inuse boundaries are mostly
636 * ignored. And therefore no slab options that rely on these boundaries
637 * may be used with merged slabcaches.
640 static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
642 unsigned long off = s->inuse; /* The end of info */
644 if (s->offset)
645 /* Freepointer is placed after the object. */
646 off += sizeof(void *);
648 if (s->flags & SLAB_STORE_USER)
649 /* We also have user information there */
650 off += 2 * sizeof(struct track);
652 if (s->size == off)
653 return 1;
655 return check_bytes_and_report(s, page, p, "Object padding",
656 p + off, POISON_INUSE, s->size - off);
659 /* Check the pad bytes at the end of a slab page */
660 static int slab_pad_check(struct kmem_cache *s, struct page *page)
662 u8 *start;
663 u8 *fault;
664 u8 *end;
665 int length;
666 int remainder;
668 if (!(s->flags & SLAB_POISON))
669 return 1;
671 start = page_address(page);
672 length = (PAGE_SIZE << compound_order(page)) - s->reserved;
673 end = start + length;
674 remainder = length % s->size;
675 if (!remainder)
676 return 1;
678 fault = check_bytes(end - remainder, POISON_INUSE, remainder);
679 if (!fault)
680 return 1;
681 while (end > fault && end[-1] == POISON_INUSE)
682 end--;
684 slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
685 print_section("Padding", end - remainder, remainder);
687 restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
688 return 0;
691 static int check_object(struct kmem_cache *s, struct page *page,
692 void *object, u8 val)
694 u8 *p = object;
695 u8 *endobject = object + s->objsize;
697 if (s->flags & SLAB_RED_ZONE) {
698 if (!check_bytes_and_report(s, page, object, "Redzone",
699 endobject, val, s->inuse - s->objsize))
700 return 0;
701 } else {
702 if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
703 check_bytes_and_report(s, page, p, "Alignment padding",
704 endobject, POISON_INUSE, s->inuse - s->objsize);
708 if (s->flags & SLAB_POISON) {
709 if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) &&
710 (!check_bytes_and_report(s, page, p, "Poison", p,
711 POISON_FREE, s->objsize - 1) ||
712 !check_bytes_and_report(s, page, p, "Poison",
713 p + s->objsize - 1, POISON_END, 1)))
714 return 0;
716 * check_pad_bytes cleans up on its own.
718 check_pad_bytes(s, page, p);
721 if (!s->offset && val == SLUB_RED_ACTIVE)
723 * Object and freepointer overlap. Cannot check
724 * freepointer while object is allocated.
726 return 1;
728 /* Check free pointer validity */
729 if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
730 object_err(s, page, p, "Freepointer corrupt");
732 * No choice but to zap it and thus lose the remainder
733 * of the free objects in this slab. May cause
734 * another error because the object count is now wrong.
736 set_freepointer(s, p, NULL);
737 return 0;
739 return 1;
742 static int check_slab(struct kmem_cache *s, struct page *page)
744 int maxobj;
746 VM_BUG_ON(!irqs_disabled());
748 if (!PageSlab(page)) {
749 slab_err(s, page, "Not a valid slab page");
750 return 0;
753 maxobj = order_objects(compound_order(page), s->size, s->reserved);
754 if (page->objects > maxobj) {
755 slab_err(s, page, "objects %u > max %u",
756 s->name, page->objects, maxobj);
757 return 0;
759 if (page->inuse > page->objects) {
760 slab_err(s, page, "inuse %u > max %u",
761 s->name, page->inuse, page->objects);
762 return 0;
764 /* Slab_pad_check fixes things up after itself */
765 slab_pad_check(s, page);
766 return 1;
770 * Determine if a certain object on a page is on the freelist. Must hold the
771 * slab lock to guarantee that the chains are in a consistent state.
773 static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
775 int nr = 0;
776 void *fp = page->freelist;
777 void *object = NULL;
778 unsigned long max_objects;
780 while (fp && nr <= page->objects) {
781 if (fp == search)
782 return 1;
783 if (!check_valid_pointer(s, page, fp)) {
784 if (object) {
785 object_err(s, page, object,
786 "Freechain corrupt");
787 set_freepointer(s, object, NULL);
788 break;
789 } else {
790 slab_err(s, page, "Freepointer corrupt");
791 page->freelist = NULL;
792 page->inuse = page->objects;
793 slab_fix(s, "Freelist cleared");
794 return 0;
796 break;
798 object = fp;
799 fp = get_freepointer(s, object);
800 nr++;
803 max_objects = order_objects(compound_order(page), s->size, s->reserved);
804 if (max_objects > MAX_OBJS_PER_PAGE)
805 max_objects = MAX_OBJS_PER_PAGE;
807 if (page->objects != max_objects) {
808 slab_err(s, page, "Wrong number of objects. Found %d but "
809 "should be %d", page->objects, max_objects);
810 page->objects = max_objects;
811 slab_fix(s, "Number of objects adjusted.");
813 if (page->inuse != page->objects - nr) {
814 slab_err(s, page, "Wrong object count. Counter is %d but "
815 "counted were %d", page->inuse, page->objects - nr);
816 page->inuse = page->objects - nr;
817 slab_fix(s, "Object count adjusted.");
819 return search == NULL;
822 static void trace(struct kmem_cache *s, struct page *page, void *object,
823 int alloc)
825 if (s->flags & SLAB_TRACE) {
826 printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
827 s->name,
828 alloc ? "alloc" : "free",
829 object, page->inuse,
830 page->freelist);
832 if (!alloc)
833 print_section("Object", (void *)object, s->objsize);
835 dump_stack();
840 * Hooks for other subsystems that check memory allocations. In a typical
841 * production configuration these hooks all should produce no code at all.
843 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
845 flags &= gfp_allowed_mask;
846 lockdep_trace_alloc(flags);
847 might_sleep_if(flags & __GFP_WAIT);
849 return should_failslab(s->objsize, flags, s->flags);
852 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object)
854 flags &= gfp_allowed_mask;
855 kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
856 kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags);
859 static inline void slab_free_hook(struct kmem_cache *s, void *x)
861 kmemleak_free_recursive(x, s->flags);
864 * Trouble is that we may no longer disable interupts in the fast path
865 * So in order to make the debug calls that expect irqs to be
866 * disabled we need to disable interrupts temporarily.
868 #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
870 unsigned long flags;
872 local_irq_save(flags);
873 kmemcheck_slab_free(s, x, s->objsize);
874 debug_check_no_locks_freed(x, s->objsize);
875 local_irq_restore(flags);
877 #endif
878 if (!(s->flags & SLAB_DEBUG_OBJECTS))
879 debug_check_no_obj_freed(x, s->objsize);
883 * Tracking of fully allocated slabs for debugging purposes.
885 static void add_full(struct kmem_cache_node *n, struct page *page)
887 spin_lock(&n->list_lock);
888 list_add(&page->lru, &n->full);
889 spin_unlock(&n->list_lock);
892 static void remove_full(struct kmem_cache *s, struct page *page)
894 struct kmem_cache_node *n;
896 if (!(s->flags & SLAB_STORE_USER))
897 return;
899 n = get_node(s, page_to_nid(page));
901 spin_lock(&n->list_lock);
902 list_del(&page->lru);
903 spin_unlock(&n->list_lock);
906 /* Tracking of the number of slabs for debugging purposes */
907 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
909 struct kmem_cache_node *n = get_node(s, node);
911 return atomic_long_read(&n->nr_slabs);
914 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
916 return atomic_long_read(&n->nr_slabs);
919 static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
921 struct kmem_cache_node *n = get_node(s, node);
924 * May be called early in order to allocate a slab for the
925 * kmem_cache_node structure. Solve the chicken-egg
926 * dilemma by deferring the increment of the count during
927 * bootstrap (see early_kmem_cache_node_alloc).
929 if (n) {
930 atomic_long_inc(&n->nr_slabs);
931 atomic_long_add(objects, &n->total_objects);
934 static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
936 struct kmem_cache_node *n = get_node(s, node);
938 atomic_long_dec(&n->nr_slabs);
939 atomic_long_sub(objects, &n->total_objects);
942 /* Object debug checks for alloc/free paths */
943 static void setup_object_debug(struct kmem_cache *s, struct page *page,
944 void *object)
946 if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
947 return;
949 init_object(s, object, SLUB_RED_INACTIVE);
950 init_tracking(s, object);
953 static noinline int alloc_debug_processing(struct kmem_cache *s, struct page *page,
954 void *object, unsigned long addr)
956 if (!check_slab(s, page))
957 goto bad;
959 if (!on_freelist(s, page, object)) {
960 object_err(s, page, object, "Object already allocated");
961 goto bad;
964 if (!check_valid_pointer(s, page, object)) {
965 object_err(s, page, object, "Freelist Pointer check fails");
966 goto bad;
969 if (!check_object(s, page, object, SLUB_RED_INACTIVE))
970 goto bad;
972 /* Success perform special debug activities for allocs */
973 if (s->flags & SLAB_STORE_USER)
974 set_track(s, object, TRACK_ALLOC, addr);
975 trace(s, page, object, 1);
976 init_object(s, object, SLUB_RED_ACTIVE);
977 return 1;
979 bad:
980 if (PageSlab(page)) {
982 * If this is a slab page then lets do the best we can
983 * to avoid issues in the future. Marking all objects
984 * as used avoids touching the remaining objects.
986 slab_fix(s, "Marking all objects used");
987 page->inuse = page->objects;
988 page->freelist = NULL;
990 return 0;
993 static noinline int free_debug_processing(struct kmem_cache *s,
994 struct page *page, void *object, unsigned long addr)
996 if (!check_slab(s, page))
997 goto fail;
999 if (!check_valid_pointer(s, page, object)) {
1000 slab_err(s, page, "Invalid object pointer 0x%p", object);
1001 goto fail;
1004 if (on_freelist(s, page, object)) {
1005 object_err(s, page, object, "Object already free");
1006 goto fail;
1009 if (!check_object(s, page, object, SLUB_RED_ACTIVE))
1010 return 0;
1012 if (unlikely(s != page->slab)) {
1013 if (!PageSlab(page)) {
1014 slab_err(s, page, "Attempt to free object(0x%p) "
1015 "outside of slab", object);
1016 } else if (!page->slab) {
1017 printk(KERN_ERR
1018 "SLUB <none>: no slab for object 0x%p.\n",
1019 object);
1020 dump_stack();
1021 } else
1022 object_err(s, page, object,
1023 "page slab pointer corrupt.");
1024 goto fail;
1027 /* Special debug activities for freeing objects */
1028 if (!PageSlubFrozen(page) && !page->freelist)
1029 remove_full(s, page);
1030 if (s->flags & SLAB_STORE_USER)
1031 set_track(s, object, TRACK_FREE, addr);
1032 trace(s, page, object, 0);
1033 init_object(s, object, SLUB_RED_INACTIVE);
1034 return 1;
1036 fail:
1037 slab_fix(s, "Object at 0x%p not freed", object);
1038 return 0;
1041 static int __init setup_slub_debug(char *str)
1043 slub_debug = DEBUG_DEFAULT_FLAGS;
1044 if (*str++ != '=' || !*str)
1046 * No options specified. Switch on full debugging.
1048 goto out;
1050 if (*str == ',')
1052 * No options but restriction on slabs. This means full
1053 * debugging for slabs matching a pattern.
1055 goto check_slabs;
1057 if (tolower(*str) == 'o') {
1059 * Avoid enabling debugging on caches if its minimum order
1060 * would increase as a result.
1062 disable_higher_order_debug = 1;
1063 goto out;
1066 slub_debug = 0;
1067 if (*str == '-')
1069 * Switch off all debugging measures.
1071 goto out;
1074 * Determine which debug features should be switched on
1076 for (; *str && *str != ','; str++) {
1077 switch (tolower(*str)) {
1078 case 'f':
1079 slub_debug |= SLAB_DEBUG_FREE;
1080 break;
1081 case 'z':
1082 slub_debug |= SLAB_RED_ZONE;
1083 break;
1084 case 'p':
1085 slub_debug |= SLAB_POISON;
1086 break;
1087 case 'u':
1088 slub_debug |= SLAB_STORE_USER;
1089 break;
1090 case 't':
1091 slub_debug |= SLAB_TRACE;
1092 break;
1093 case 'a':
1094 slub_debug |= SLAB_FAILSLAB;
1095 break;
1096 default:
1097 printk(KERN_ERR "slub_debug option '%c' "
1098 "unknown. skipped\n", *str);
1102 check_slabs:
1103 if (*str == ',')
1104 slub_debug_slabs = str + 1;
1105 out:
1106 return 1;
1109 __setup("slub_debug", setup_slub_debug);
1111 static unsigned long kmem_cache_flags(unsigned long objsize,
1112 unsigned long flags, const char *name,
1113 void (*ctor)(void *))
1116 * Enable debugging if selected on the kernel commandline.
1118 if (slub_debug && (!slub_debug_slabs ||
1119 !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
1120 flags |= slub_debug;
1122 return flags;
1124 #else
1125 static inline void setup_object_debug(struct kmem_cache *s,
1126 struct page *page, void *object) {}
1128 static inline int alloc_debug_processing(struct kmem_cache *s,
1129 struct page *page, void *object, unsigned long addr) { return 0; }
1131 static inline int free_debug_processing(struct kmem_cache *s,
1132 struct page *page, void *object, unsigned long addr) { return 0; }
1134 static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
1135 { return 1; }
1136 static inline int check_object(struct kmem_cache *s, struct page *page,
1137 void *object, u8 val) { return 1; }
1138 static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
1139 static inline unsigned long kmem_cache_flags(unsigned long objsize,
1140 unsigned long flags, const char *name,
1141 void (*ctor)(void *))
1143 return flags;
1145 #define slub_debug 0
1147 #define disable_higher_order_debug 0
1149 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
1150 { return 0; }
1151 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
1152 { return 0; }
1153 static inline void inc_slabs_node(struct kmem_cache *s, int node,
1154 int objects) {}
1155 static inline void dec_slabs_node(struct kmem_cache *s, int node,
1156 int objects) {}
1158 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
1159 { return 0; }
1161 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
1162 void *object) {}
1164 static inline void slab_free_hook(struct kmem_cache *s, void *x) {}
1166 #endif /* CONFIG_SLUB_DEBUG */
1169 * Slab allocation and freeing
1171 static inline struct page *alloc_slab_page(gfp_t flags, int node,
1172 struct kmem_cache_order_objects oo)
1174 int order = oo_order(oo);
1176 flags |= __GFP_NOTRACK;
1178 if (node == NUMA_NO_NODE)
1179 return alloc_pages(flags, order);
1180 else
1181 return alloc_pages_exact_node(node, flags, order);
1184 static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1186 struct page *page;
1187 struct kmem_cache_order_objects oo = s->oo;
1188 gfp_t alloc_gfp;
1190 flags |= s->allocflags;
1193 * Let the initial higher-order allocation fail under memory pressure
1194 * so we fall-back to the minimum order allocation.
1196 alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
1198 page = alloc_slab_page(alloc_gfp, node, oo);
1199 if (unlikely(!page)) {
1200 oo = s->min;
1202 * Allocation may have failed due to fragmentation.
1203 * Try a lower order alloc if possible
1205 page = alloc_slab_page(flags, node, oo);
1206 if (!page)
1207 return NULL;
1209 stat(s, ORDER_FALLBACK);
1212 if (kmemcheck_enabled
1213 && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
1214 int pages = 1 << oo_order(oo);
1216 kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
1219 * Objects from caches that have a constructor don't get
1220 * cleared when they're allocated, so we need to do it here.
1222 if (s->ctor)
1223 kmemcheck_mark_uninitialized_pages(page, pages);
1224 else
1225 kmemcheck_mark_unallocated_pages(page, pages);
1228 page->objects = oo_objects(oo);
1229 mod_zone_page_state(page_zone(page),
1230 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1231 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1232 1 << oo_order(oo));
1234 return page;
1237 static void setup_object(struct kmem_cache *s, struct page *page,
1238 void *object)
1240 setup_object_debug(s, page, object);
1241 if (unlikely(s->ctor))
1242 s->ctor(object);
1245 static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1247 struct page *page;
1248 void *start;
1249 void *last;
1250 void *p;
1252 BUG_ON(flags & GFP_SLAB_BUG_MASK);
1254 page = allocate_slab(s,
1255 flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
1256 if (!page)
1257 goto out;
1259 inc_slabs_node(s, page_to_nid(page), page->objects);
1260 page->slab = s;
1261 page->flags |= 1 << PG_slab;
1263 start = page_address(page);
1265 if (unlikely(s->flags & SLAB_POISON))
1266 memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
1268 last = start;
1269 for_each_object(p, s, start, page->objects) {
1270 setup_object(s, page, last);
1271 set_freepointer(s, last, p);
1272 last = p;
1274 setup_object(s, page, last);
1275 set_freepointer(s, last, NULL);
1277 page->freelist = start;
1278 page->inuse = 0;
1279 out:
1280 return page;
1283 static void __free_slab(struct kmem_cache *s, struct page *page)
1285 int order = compound_order(page);
1286 int pages = 1 << order;
1288 if (kmem_cache_debug(s)) {
1289 void *p;
1291 slab_pad_check(s, page);
1292 for_each_object(p, s, page_address(page),
1293 page->objects)
1294 check_object(s, page, p, SLUB_RED_INACTIVE);
1297 kmemcheck_free_shadow(page, compound_order(page));
1299 mod_zone_page_state(page_zone(page),
1300 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1301 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1302 -pages);
1304 __ClearPageSlab(page);
1305 reset_page_mapcount(page);
1306 if (current->reclaim_state)
1307 current->reclaim_state->reclaimed_slab += pages;
1308 __free_pages(page, order);
1311 #define need_reserve_slab_rcu \
1312 (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
1314 static void rcu_free_slab(struct rcu_head *h)
1316 struct page *page;
1318 if (need_reserve_slab_rcu)
1319 page = virt_to_head_page(h);
1320 else
1321 page = container_of((struct list_head *)h, struct page, lru);
1323 __free_slab(page->slab, page);
1326 static void free_slab(struct kmem_cache *s, struct page *page)
1328 if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
1329 struct rcu_head *head;
1331 if (need_reserve_slab_rcu) {
1332 int order = compound_order(page);
1333 int offset = (PAGE_SIZE << order) - s->reserved;
1335 VM_BUG_ON(s->reserved != sizeof(*head));
1336 head = page_address(page) + offset;
1337 } else {
1339 * RCU free overloads the RCU head over the LRU
1341 head = (void *)&page->lru;
1344 call_rcu(head, rcu_free_slab);
1345 } else
1346 __free_slab(s, page);
1349 static void discard_slab(struct kmem_cache *s, struct page *page)
1351 dec_slabs_node(s, page_to_nid(page), page->objects);
1352 free_slab(s, page);
1356 * Per slab locking using the pagelock
1358 static __always_inline void slab_lock(struct page *page)
1360 bit_spin_lock(PG_locked, &page->flags);
1363 static __always_inline void slab_unlock(struct page *page)
1365 __bit_spin_unlock(PG_locked, &page->flags);
1368 static __always_inline int slab_trylock(struct page *page)
1370 int rc = 1;
1372 rc = bit_spin_trylock(PG_locked, &page->flags);
1373 return rc;
1377 * Management of partially allocated slabs
1379 static void add_partial(struct kmem_cache_node *n,
1380 struct page *page, int tail)
1382 spin_lock(&n->list_lock);
1383 n->nr_partial++;
1384 if (tail)
1385 list_add_tail(&page->lru, &n->partial);
1386 else
1387 list_add(&page->lru, &n->partial);
1388 spin_unlock(&n->list_lock);
1391 static inline void __remove_partial(struct kmem_cache_node *n,
1392 struct page *page)
1394 list_del(&page->lru);
1395 n->nr_partial--;
1398 static void remove_partial(struct kmem_cache *s, struct page *page)
1400 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1402 spin_lock(&n->list_lock);
1403 __remove_partial(n, page);
1404 spin_unlock(&n->list_lock);
1408 * Lock slab and remove from the partial list.
1410 * Must hold list_lock.
1412 static inline int lock_and_freeze_slab(struct kmem_cache_node *n,
1413 struct page *page)
1415 if (slab_trylock(page)) {
1416 __remove_partial(n, page);
1417 __SetPageSlubFrozen(page);
1418 return 1;
1420 return 0;
1424 * Try to allocate a partial slab from a specific node.
1426 static struct page *get_partial_node(struct kmem_cache_node *n)
1428 struct page *page;
1431 * Racy check. If we mistakenly see no partial slabs then we
1432 * just allocate an empty slab. If we mistakenly try to get a
1433 * partial slab and there is none available then get_partials()
1434 * will return NULL.
1436 if (!n || !n->nr_partial)
1437 return NULL;
1439 spin_lock(&n->list_lock);
1440 list_for_each_entry(page, &n->partial, lru)
1441 if (lock_and_freeze_slab(n, page))
1442 goto out;
1443 page = NULL;
1444 out:
1445 spin_unlock(&n->list_lock);
1446 return page;
1450 * Get a page from somewhere. Search in increasing NUMA distances.
1452 static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
1454 #ifdef CONFIG_NUMA
1455 struct zonelist *zonelist;
1456 struct zoneref *z;
1457 struct zone *zone;
1458 enum zone_type high_zoneidx = gfp_zone(flags);
1459 struct page *page;
1462 * The defrag ratio allows a configuration of the tradeoffs between
1463 * inter node defragmentation and node local allocations. A lower
1464 * defrag_ratio increases the tendency to do local allocations
1465 * instead of attempting to obtain partial slabs from other nodes.
1467 * If the defrag_ratio is set to 0 then kmalloc() always
1468 * returns node local objects. If the ratio is higher then kmalloc()
1469 * may return off node objects because partial slabs are obtained
1470 * from other nodes and filled up.
1472 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
1473 * defrag_ratio = 1000) then every (well almost) allocation will
1474 * first attempt to defrag slab caches on other nodes. This means
1475 * scanning over all nodes to look for partial slabs which may be
1476 * expensive if we do it every time we are trying to find a slab
1477 * with available objects.
1479 if (!s->remote_node_defrag_ratio ||
1480 get_cycles() % 1024 > s->remote_node_defrag_ratio)
1481 return NULL;
1483 get_mems_allowed();
1484 zonelist = node_zonelist(slab_node(current->mempolicy), flags);
1485 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
1486 struct kmem_cache_node *n;
1488 n = get_node(s, zone_to_nid(zone));
1490 if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
1491 n->nr_partial > s->min_partial) {
1492 page = get_partial_node(n);
1493 if (page) {
1494 put_mems_allowed();
1495 return page;
1499 put_mems_allowed();
1500 #endif
1501 return NULL;
1505 * Get a partial page, lock it and return it.
1507 static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
1509 struct page *page;
1510 int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
1512 page = get_partial_node(get_node(s, searchnode));
1513 if (page || node != NUMA_NO_NODE)
1514 return page;
1516 return get_any_partial(s, flags);
1520 * Move a page back to the lists.
1522 * Must be called with the slab lock held.
1524 * On exit the slab lock will have been dropped.
1526 static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
1527 __releases(bitlock)
1529 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1531 __ClearPageSlubFrozen(page);
1532 if (page->inuse) {
1534 if (page->freelist) {
1535 add_partial(n, page, tail);
1536 stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
1537 } else {
1538 stat(s, DEACTIVATE_FULL);
1539 if (kmem_cache_debug(s) && (s->flags & SLAB_STORE_USER))
1540 add_full(n, page);
1542 slab_unlock(page);
1543 } else {
1544 stat(s, DEACTIVATE_EMPTY);
1545 if (n->nr_partial < s->min_partial) {
1547 * Adding an empty slab to the partial slabs in order
1548 * to avoid page allocator overhead. This slab needs
1549 * to come after the other slabs with objects in
1550 * so that the others get filled first. That way the
1551 * size of the partial list stays small.
1553 * kmem_cache_shrink can reclaim any empty slabs from
1554 * the partial list.
1556 add_partial(n, page, 1);
1557 slab_unlock(page);
1558 } else {
1559 slab_unlock(page);
1560 stat(s, FREE_SLAB);
1561 discard_slab(s, page);
1566 #ifdef CONFIG_PREEMPT
1568 * Calculate the next globally unique transaction for disambiguiation
1569 * during cmpxchg. The transactions start with the cpu number and are then
1570 * incremented by CONFIG_NR_CPUS.
1572 #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
1573 #else
1575 * No preemption supported therefore also no need to check for
1576 * different cpus.
1578 #define TID_STEP 1
1579 #endif
1581 static inline unsigned long next_tid(unsigned long tid)
1583 return tid + TID_STEP;
1586 static inline unsigned int tid_to_cpu(unsigned long tid)
1588 return tid % TID_STEP;
1591 static inline unsigned long tid_to_event(unsigned long tid)
1593 return tid / TID_STEP;
1596 static inline unsigned int init_tid(int cpu)
1598 return cpu;
1601 static inline void note_cmpxchg_failure(const char *n,
1602 const struct kmem_cache *s, unsigned long tid)
1604 #ifdef SLUB_DEBUG_CMPXCHG
1605 unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
1607 printk(KERN_INFO "%s %s: cmpxchg redo ", n, s->name);
1609 #ifdef CONFIG_PREEMPT
1610 if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
1611 printk("due to cpu change %d -> %d\n",
1612 tid_to_cpu(tid), tid_to_cpu(actual_tid));
1613 else
1614 #endif
1615 if (tid_to_event(tid) != tid_to_event(actual_tid))
1616 printk("due to cpu running other code. Event %ld->%ld\n",
1617 tid_to_event(tid), tid_to_event(actual_tid));
1618 else
1619 printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
1620 actual_tid, tid, next_tid(tid));
1621 #endif
1622 stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
1625 void init_kmem_cache_cpus(struct kmem_cache *s)
1627 int cpu;
1629 for_each_possible_cpu(cpu)
1630 per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
1633 * Remove the cpu slab
1635 static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
1636 __releases(bitlock)
1638 struct page *page = c->page;
1639 int tail = 1;
1641 if (page->freelist)
1642 stat(s, DEACTIVATE_REMOTE_FREES);
1644 * Merge cpu freelist into slab freelist. Typically we get here
1645 * because both freelists are empty. So this is unlikely
1646 * to occur.
1648 while (unlikely(c->freelist)) {
1649 void **object;
1651 tail = 0; /* Hot objects. Put the slab first */
1653 /* Retrieve object from cpu_freelist */
1654 object = c->freelist;
1655 c->freelist = get_freepointer(s, c->freelist);
1657 /* And put onto the regular freelist */
1658 set_freepointer(s, object, page->freelist);
1659 page->freelist = object;
1660 page->inuse--;
1662 c->page = NULL;
1663 c->tid = next_tid(c->tid);
1664 unfreeze_slab(s, page, tail);
1667 static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
1669 stat(s, CPUSLAB_FLUSH);
1670 slab_lock(c->page);
1671 deactivate_slab(s, c);
1675 * Flush cpu slab.
1677 * Called from IPI handler with interrupts disabled.
1679 static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
1681 struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
1683 if (likely(c && c->page))
1684 flush_slab(s, c);
1687 static void flush_cpu_slab(void *d)
1689 struct kmem_cache *s = d;
1691 __flush_cpu_slab(s, smp_processor_id());
1694 static void flush_all(struct kmem_cache *s)
1696 on_each_cpu(flush_cpu_slab, s, 1);
1700 * Check if the objects in a per cpu structure fit numa
1701 * locality expectations.
1703 static inline int node_match(struct kmem_cache_cpu *c, int node)
1705 #ifdef CONFIG_NUMA
1706 if (node != NUMA_NO_NODE && c->node != node)
1707 return 0;
1708 #endif
1709 return 1;
1712 static int count_free(struct page *page)
1714 return page->objects - page->inuse;
1717 static unsigned long count_partial(struct kmem_cache_node *n,
1718 int (*get_count)(struct page *))
1720 unsigned long flags;
1721 unsigned long x = 0;
1722 struct page *page;
1724 spin_lock_irqsave(&n->list_lock, flags);
1725 list_for_each_entry(page, &n->partial, lru)
1726 x += get_count(page);
1727 spin_unlock_irqrestore(&n->list_lock, flags);
1728 return x;
1731 static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
1733 #ifdef CONFIG_SLUB_DEBUG
1734 return atomic_long_read(&n->total_objects);
1735 #else
1736 return 0;
1737 #endif
1740 static noinline void
1741 slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
1743 int node;
1745 printk(KERN_WARNING
1746 "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
1747 nid, gfpflags);
1748 printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, "
1749 "default order: %d, min order: %d\n", s->name, s->objsize,
1750 s->size, oo_order(s->oo), oo_order(s->min));
1752 if (oo_order(s->min) > get_order(s->objsize))
1753 printk(KERN_WARNING " %s debugging increased min order, use "
1754 "slub_debug=O to disable.\n", s->name);
1756 for_each_online_node(node) {
1757 struct kmem_cache_node *n = get_node(s, node);
1758 unsigned long nr_slabs;
1759 unsigned long nr_objs;
1760 unsigned long nr_free;
1762 if (!n)
1763 continue;
1765 nr_free = count_partial(n, count_free);
1766 nr_slabs = node_nr_slabs(n);
1767 nr_objs = node_nr_objs(n);
1769 printk(KERN_WARNING
1770 " node %d: slabs: %ld, objs: %ld, free: %ld\n",
1771 node, nr_slabs, nr_objs, nr_free);
1776 * Slow path. The lockless freelist is empty or we need to perform
1777 * debugging duties.
1779 * Interrupts are disabled.
1781 * Processing is still very fast if new objects have been freed to the
1782 * regular freelist. In that case we simply take over the regular freelist
1783 * as the lockless freelist and zap the regular freelist.
1785 * If that is not working then we fall back to the partial lists. We take the
1786 * first element of the freelist as the object to allocate now and move the
1787 * rest of the freelist to the lockless freelist.
1789 * And if we were unable to get a new slab from the partial slab lists then
1790 * we need to allocate a new slab. This is the slowest path since it involves
1791 * a call to the page allocator and the setup of a new slab.
1793 static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
1794 unsigned long addr, struct kmem_cache_cpu *c)
1796 void **object;
1797 struct page *page;
1798 unsigned long flags;
1800 local_irq_save(flags);
1801 #ifdef CONFIG_PREEMPT
1803 * We may have been preempted and rescheduled on a different
1804 * cpu before disabling interrupts. Need to reload cpu area
1805 * pointer.
1807 c = this_cpu_ptr(s->cpu_slab);
1808 #endif
1810 /* We handle __GFP_ZERO in the caller */
1811 gfpflags &= ~__GFP_ZERO;
1813 page = c->page;
1814 if (!page)
1815 goto new_slab;
1817 slab_lock(page);
1818 if (unlikely(!node_match(c, node)))
1819 goto another_slab;
1821 stat(s, ALLOC_REFILL);
1823 load_freelist:
1824 object = page->freelist;
1825 if (unlikely(!object))
1826 goto another_slab;
1827 if (kmem_cache_debug(s))
1828 goto debug;
1830 c->freelist = get_freepointer(s, object);
1831 page->inuse = page->objects;
1832 page->freelist = NULL;
1834 slab_unlock(page);
1835 c->tid = next_tid(c->tid);
1836 local_irq_restore(flags);
1837 stat(s, ALLOC_SLOWPATH);
1838 return object;
1840 another_slab:
1841 deactivate_slab(s, c);
1843 new_slab:
1844 page = get_partial(s, gfpflags, node);
1845 if (page) {
1846 stat(s, ALLOC_FROM_PARTIAL);
1847 c->node = page_to_nid(page);
1848 c->page = page;
1849 goto load_freelist;
1852 gfpflags &= gfp_allowed_mask;
1853 if (gfpflags & __GFP_WAIT)
1854 local_irq_enable();
1856 page = new_slab(s, gfpflags, node);
1858 if (gfpflags & __GFP_WAIT)
1859 local_irq_disable();
1861 if (page) {
1862 c = __this_cpu_ptr(s->cpu_slab);
1863 stat(s, ALLOC_SLAB);
1864 if (c->page)
1865 flush_slab(s, c);
1867 slab_lock(page);
1868 __SetPageSlubFrozen(page);
1869 c->node = page_to_nid(page);
1870 c->page = page;
1871 goto load_freelist;
1873 if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
1874 slab_out_of_memory(s, gfpflags, node);
1875 local_irq_restore(flags);
1876 return NULL;
1877 debug:
1878 if (!alloc_debug_processing(s, page, object, addr))
1879 goto another_slab;
1881 page->inuse++;
1882 page->freelist = get_freepointer(s, object);
1883 deactivate_slab(s, c);
1884 c->page = NULL;
1885 c->node = NUMA_NO_NODE;
1886 local_irq_restore(flags);
1887 return object;
1891 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1892 * have the fastpath folded into their functions. So no function call
1893 * overhead for requests that can be satisfied on the fastpath.
1895 * The fastpath works by first checking if the lockless freelist can be used.
1896 * If not then __slab_alloc is called for slow processing.
1898 * Otherwise we can simply pick the next object from the lockless free list.
1900 static __always_inline void *slab_alloc(struct kmem_cache *s,
1901 gfp_t gfpflags, int node, unsigned long addr)
1903 void **object;
1904 struct kmem_cache_cpu *c;
1905 unsigned long tid;
1907 if (slab_pre_alloc_hook(s, gfpflags))
1908 return NULL;
1910 redo:
1913 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
1914 * enabled. We may switch back and forth between cpus while
1915 * reading from one cpu area. That does not matter as long
1916 * as we end up on the original cpu again when doing the cmpxchg.
1918 c = __this_cpu_ptr(s->cpu_slab);
1921 * The transaction ids are globally unique per cpu and per operation on
1922 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
1923 * occurs on the right processor and that there was no operation on the
1924 * linked list in between.
1926 tid = c->tid;
1927 barrier();
1929 object = c->freelist;
1930 if (unlikely(!object || !node_match(c, node)))
1932 object = __slab_alloc(s, gfpflags, node, addr, c);
1934 else {
1936 * The cmpxchg will only match if there was no additional
1937 * operation and if we are on the right processor.
1939 * The cmpxchg does the following atomically (without lock semantics!)
1940 * 1. Relocate first pointer to the current per cpu area.
1941 * 2. Verify that tid and freelist have not been changed
1942 * 3. If they were not changed replace tid and freelist
1944 * Since this is without lock semantics the protection is only against
1945 * code executing on this cpu *not* from access by other cpus.
1947 if (unlikely(!irqsafe_cpu_cmpxchg_double(
1948 s->cpu_slab->freelist, s->cpu_slab->tid,
1949 object, tid,
1950 get_freepointer_safe(s, object), next_tid(tid)))) {
1952 note_cmpxchg_failure("slab_alloc", s, tid);
1953 goto redo;
1955 stat(s, ALLOC_FASTPATH);
1958 if (unlikely(gfpflags & __GFP_ZERO) && object)
1959 memset(object, 0, s->objsize);
1961 slab_post_alloc_hook(s, gfpflags, object);
1963 return object;
1966 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
1968 void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
1970 trace_kmem_cache_alloc(_RET_IP_, ret, s->objsize, s->size, gfpflags);
1972 return ret;
1974 EXPORT_SYMBOL(kmem_cache_alloc);
1976 #ifdef CONFIG_TRACING
1977 void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
1979 void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
1980 trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
1981 return ret;
1983 EXPORT_SYMBOL(kmem_cache_alloc_trace);
1985 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
1987 void *ret = kmalloc_order(size, flags, order);
1988 trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
1989 return ret;
1991 EXPORT_SYMBOL(kmalloc_order_trace);
1992 #endif
1994 #ifdef CONFIG_NUMA
1995 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
1997 void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
1999 trace_kmem_cache_alloc_node(_RET_IP_, ret,
2000 s->objsize, s->size, gfpflags, node);
2002 return ret;
2004 EXPORT_SYMBOL(kmem_cache_alloc_node);
2006 #ifdef CONFIG_TRACING
2007 void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
2008 gfp_t gfpflags,
2009 int node, size_t size)
2011 void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
2013 trace_kmalloc_node(_RET_IP_, ret,
2014 size, s->size, gfpflags, node);
2015 return ret;
2017 EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
2018 #endif
2019 #endif
2022 * Slow patch handling. This may still be called frequently since objects
2023 * have a longer lifetime than the cpu slabs in most processing loads.
2025 * So we still attempt to reduce cache line usage. Just take the slab
2026 * lock and free the item. If there is no additional partial page
2027 * handling required then we can return immediately.
2029 static void __slab_free(struct kmem_cache *s, struct page *page,
2030 void *x, unsigned long addr)
2032 void *prior;
2033 void **object = (void *)x;
2034 unsigned long flags;
2036 local_irq_save(flags);
2037 slab_lock(page);
2038 stat(s, FREE_SLOWPATH);
2040 if (kmem_cache_debug(s) && !free_debug_processing(s, page, x, addr))
2041 goto out_unlock;
2043 prior = page->freelist;
2044 set_freepointer(s, object, prior);
2045 page->freelist = object;
2046 page->inuse--;
2048 if (unlikely(PageSlubFrozen(page))) {
2049 stat(s, FREE_FROZEN);
2050 goto out_unlock;
2053 if (unlikely(!page->inuse))
2054 goto slab_empty;
2057 * Objects left in the slab. If it was not on the partial list before
2058 * then add it.
2060 if (unlikely(!prior)) {
2061 add_partial(get_node(s, page_to_nid(page)), page, 1);
2062 stat(s, FREE_ADD_PARTIAL);
2065 out_unlock:
2066 slab_unlock(page);
2067 local_irq_restore(flags);
2068 return;
2070 slab_empty:
2071 if (prior) {
2073 * Slab still on the partial list.
2075 remove_partial(s, page);
2076 stat(s, FREE_REMOVE_PARTIAL);
2078 slab_unlock(page);
2079 local_irq_restore(flags);
2080 stat(s, FREE_SLAB);
2081 discard_slab(s, page);
2085 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
2086 * can perform fastpath freeing without additional function calls.
2088 * The fastpath is only possible if we are freeing to the current cpu slab
2089 * of this processor. This typically the case if we have just allocated
2090 * the item before.
2092 * If fastpath is not possible then fall back to __slab_free where we deal
2093 * with all sorts of special processing.
2095 static __always_inline void slab_free(struct kmem_cache *s,
2096 struct page *page, void *x, unsigned long addr)
2098 void **object = (void *)x;
2099 struct kmem_cache_cpu *c;
2100 unsigned long tid;
2102 slab_free_hook(s, x);
2104 redo:
2107 * Determine the currently cpus per cpu slab.
2108 * The cpu may change afterward. However that does not matter since
2109 * data is retrieved via this pointer. If we are on the same cpu
2110 * during the cmpxchg then the free will succedd.
2112 c = __this_cpu_ptr(s->cpu_slab);
2114 tid = c->tid;
2115 barrier();
2117 if (likely(page == c->page)) {
2118 set_freepointer(s, object, c->freelist);
2120 if (unlikely(!irqsafe_cpu_cmpxchg_double(
2121 s->cpu_slab->freelist, s->cpu_slab->tid,
2122 c->freelist, tid,
2123 object, next_tid(tid)))) {
2125 note_cmpxchg_failure("slab_free", s, tid);
2126 goto redo;
2128 stat(s, FREE_FASTPATH);
2129 } else
2130 __slab_free(s, page, x, addr);
2134 void kmem_cache_free(struct kmem_cache *s, void *x)
2136 struct page *page;
2138 page = virt_to_head_page(x);
2140 slab_free(s, page, x, _RET_IP_);
2142 trace_kmem_cache_free(_RET_IP_, x);
2144 EXPORT_SYMBOL(kmem_cache_free);
2147 * Object placement in a slab is made very easy because we always start at
2148 * offset 0. If we tune the size of the object to the alignment then we can
2149 * get the required alignment by putting one properly sized object after
2150 * another.
2152 * Notice that the allocation order determines the sizes of the per cpu
2153 * caches. Each processor has always one slab available for allocations.
2154 * Increasing the allocation order reduces the number of times that slabs
2155 * must be moved on and off the partial lists and is therefore a factor in
2156 * locking overhead.
2160 * Mininum / Maximum order of slab pages. This influences locking overhead
2161 * and slab fragmentation. A higher order reduces the number of partial slabs
2162 * and increases the number of allocations possible without having to
2163 * take the list_lock.
2165 static int slub_min_order;
2166 static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
2167 static int slub_min_objects;
2170 * Merge control. If this is set then no merging of slab caches will occur.
2171 * (Could be removed. This was introduced to pacify the merge skeptics.)
2173 static int slub_nomerge;
2176 * Calculate the order of allocation given an slab object size.
2178 * The order of allocation has significant impact on performance and other
2179 * system components. Generally order 0 allocations should be preferred since
2180 * order 0 does not cause fragmentation in the page allocator. Larger objects
2181 * be problematic to put into order 0 slabs because there may be too much
2182 * unused space left. We go to a higher order if more than 1/16th of the slab
2183 * would be wasted.
2185 * In order to reach satisfactory performance we must ensure that a minimum
2186 * number of objects is in one slab. Otherwise we may generate too much
2187 * activity on the partial lists which requires taking the list_lock. This is
2188 * less a concern for large slabs though which are rarely used.
2190 * slub_max_order specifies the order where we begin to stop considering the
2191 * number of objects in a slab as critical. If we reach slub_max_order then
2192 * we try to keep the page order as low as possible. So we accept more waste
2193 * of space in favor of a small page order.
2195 * Higher order allocations also allow the placement of more objects in a
2196 * slab and thereby reduce object handling overhead. If the user has
2197 * requested a higher mininum order then we start with that one instead of
2198 * the smallest order which will fit the object.
2200 static inline int slab_order(int size, int min_objects,
2201 int max_order, int fract_leftover, int reserved)
2203 int order;
2204 int rem;
2205 int min_order = slub_min_order;
2207 if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE)
2208 return get_order(size * MAX_OBJS_PER_PAGE) - 1;
2210 for (order = max(min_order,
2211 fls(min_objects * size - 1) - PAGE_SHIFT);
2212 order <= max_order; order++) {
2214 unsigned long slab_size = PAGE_SIZE << order;
2216 if (slab_size < min_objects * size + reserved)
2217 continue;
2219 rem = (slab_size - reserved) % size;
2221 if (rem <= slab_size / fract_leftover)
2222 break;
2226 return order;
2229 static inline int calculate_order(int size, int reserved)
2231 int order;
2232 int min_objects;
2233 int fraction;
2234 int max_objects;
2237 * Attempt to find best configuration for a slab. This
2238 * works by first attempting to generate a layout with
2239 * the best configuration and backing off gradually.
2241 * First we reduce the acceptable waste in a slab. Then
2242 * we reduce the minimum objects required in a slab.
2244 min_objects = slub_min_objects;
2245 if (!min_objects)
2246 min_objects = 4 * (fls(nr_cpu_ids) + 1);
2247 max_objects = order_objects(slub_max_order, size, reserved);
2248 min_objects = min(min_objects, max_objects);
2250 while (min_objects > 1) {
2251 fraction = 16;
2252 while (fraction >= 4) {
2253 order = slab_order(size, min_objects,
2254 slub_max_order, fraction, reserved);
2255 if (order <= slub_max_order)
2256 return order;
2257 fraction /= 2;
2259 min_objects--;
2263 * We were unable to place multiple objects in a slab. Now
2264 * lets see if we can place a single object there.
2266 order = slab_order(size, 1, slub_max_order, 1, reserved);
2267 if (order <= slub_max_order)
2268 return order;
2271 * Doh this slab cannot be placed using slub_max_order.
2273 order = slab_order(size, 1, MAX_ORDER, 1, reserved);
2274 if (order < MAX_ORDER)
2275 return order;
2276 return -ENOSYS;
2280 * Figure out what the alignment of the objects will be.
2282 static unsigned long calculate_alignment(unsigned long flags,
2283 unsigned long align, unsigned long size)
2286 * If the user wants hardware cache aligned objects then follow that
2287 * suggestion if the object is sufficiently large.
2289 * The hardware cache alignment cannot override the specified
2290 * alignment though. If that is greater then use it.
2292 if (flags & SLAB_HWCACHE_ALIGN) {
2293 unsigned long ralign = cache_line_size();
2294 while (size <= ralign / 2)
2295 ralign /= 2;
2296 align = max(align, ralign);
2299 if (align < ARCH_SLAB_MINALIGN)
2300 align = ARCH_SLAB_MINALIGN;
2302 return ALIGN(align, sizeof(void *));
2305 static void
2306 init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
2308 n->nr_partial = 0;
2309 spin_lock_init(&n->list_lock);
2310 INIT_LIST_HEAD(&n->partial);
2311 #ifdef CONFIG_SLUB_DEBUG
2312 atomic_long_set(&n->nr_slabs, 0);
2313 atomic_long_set(&n->total_objects, 0);
2314 INIT_LIST_HEAD(&n->full);
2315 #endif
2318 static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
2320 BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
2321 SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
2324 * Must align to double word boundary for the double cmpxchg
2325 * instructions to work; see __pcpu_double_call_return_bool().
2327 s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu),
2328 2 * sizeof(void *));
2330 if (!s->cpu_slab)
2331 return 0;
2333 init_kmem_cache_cpus(s);
2335 return 1;
2338 static struct kmem_cache *kmem_cache_node;
2341 * No kmalloc_node yet so do it by hand. We know that this is the first
2342 * slab on the node for this slabcache. There are no concurrent accesses
2343 * possible.
2345 * Note that this function only works on the kmalloc_node_cache
2346 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2347 * memory on a fresh node that has no slab structures yet.
2349 static void early_kmem_cache_node_alloc(int node)
2351 struct page *page;
2352 struct kmem_cache_node *n;
2353 unsigned long flags;
2355 BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
2357 page = new_slab(kmem_cache_node, GFP_NOWAIT, node);
2359 BUG_ON(!page);
2360 if (page_to_nid(page) != node) {
2361 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2362 "node %d\n", node);
2363 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2364 "in order to be able to continue\n");
2367 n = page->freelist;
2368 BUG_ON(!n);
2369 page->freelist = get_freepointer(kmem_cache_node, n);
2370 page->inuse++;
2371 kmem_cache_node->node[node] = n;
2372 #ifdef CONFIG_SLUB_DEBUG
2373 init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
2374 init_tracking(kmem_cache_node, n);
2375 #endif
2376 init_kmem_cache_node(n, kmem_cache_node);
2377 inc_slabs_node(kmem_cache_node, node, page->objects);
2380 * lockdep requires consistent irq usage for each lock
2381 * so even though there cannot be a race this early in
2382 * the boot sequence, we still disable irqs.
2384 local_irq_save(flags);
2385 add_partial(n, page, 0);
2386 local_irq_restore(flags);
2389 static void free_kmem_cache_nodes(struct kmem_cache *s)
2391 int node;
2393 for_each_node_state(node, N_NORMAL_MEMORY) {
2394 struct kmem_cache_node *n = s->node[node];
2396 if (n)
2397 kmem_cache_free(kmem_cache_node, n);
2399 s->node[node] = NULL;
2403 static int init_kmem_cache_nodes(struct kmem_cache *s)
2405 int node;
2407 for_each_node_state(node, N_NORMAL_MEMORY) {
2408 struct kmem_cache_node *n;
2410 if (slab_state == DOWN) {
2411 early_kmem_cache_node_alloc(node);
2412 continue;
2414 n = kmem_cache_alloc_node(kmem_cache_node,
2415 GFP_KERNEL, node);
2417 if (!n) {
2418 free_kmem_cache_nodes(s);
2419 return 0;
2422 s->node[node] = n;
2423 init_kmem_cache_node(n, s);
2425 return 1;
2428 static void set_min_partial(struct kmem_cache *s, unsigned long min)
2430 if (min < MIN_PARTIAL)
2431 min = MIN_PARTIAL;
2432 else if (min > MAX_PARTIAL)
2433 min = MAX_PARTIAL;
2434 s->min_partial = min;
2438 * calculate_sizes() determines the order and the distribution of data within
2439 * a slab object.
2441 static int calculate_sizes(struct kmem_cache *s, int forced_order)
2443 unsigned long flags = s->flags;
2444 unsigned long size = s->objsize;
2445 unsigned long align = s->align;
2446 int order;
2449 * Round up object size to the next word boundary. We can only
2450 * place the free pointer at word boundaries and this determines
2451 * the possible location of the free pointer.
2453 size = ALIGN(size, sizeof(void *));
2455 #ifdef CONFIG_SLUB_DEBUG
2457 * Determine if we can poison the object itself. If the user of
2458 * the slab may touch the object after free or before allocation
2459 * then we should never poison the object itself.
2461 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
2462 !s->ctor)
2463 s->flags |= __OBJECT_POISON;
2464 else
2465 s->flags &= ~__OBJECT_POISON;
2469 * If we are Redzoning then check if there is some space between the
2470 * end of the object and the free pointer. If not then add an
2471 * additional word to have some bytes to store Redzone information.
2473 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2474 size += sizeof(void *);
2475 #endif
2478 * With that we have determined the number of bytes in actual use
2479 * by the object. This is the potential offset to the free pointer.
2481 s->inuse = size;
2483 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
2484 s->ctor)) {
2486 * Relocate free pointer after the object if it is not
2487 * permitted to overwrite the first word of the object on
2488 * kmem_cache_free.
2490 * This is the case if we do RCU, have a constructor or
2491 * destructor or are poisoning the objects.
2493 s->offset = size;
2494 size += sizeof(void *);
2497 #ifdef CONFIG_SLUB_DEBUG
2498 if (flags & SLAB_STORE_USER)
2500 * Need to store information about allocs and frees after
2501 * the object.
2503 size += 2 * sizeof(struct track);
2505 if (flags & SLAB_RED_ZONE)
2507 * Add some empty padding so that we can catch
2508 * overwrites from earlier objects rather than let
2509 * tracking information or the free pointer be
2510 * corrupted if a user writes before the start
2511 * of the object.
2513 size += sizeof(void *);
2514 #endif
2517 * Determine the alignment based on various parameters that the
2518 * user specified and the dynamic determination of cache line size
2519 * on bootup.
2521 align = calculate_alignment(flags, align, s->objsize);
2522 s->align = align;
2525 * SLUB stores one object immediately after another beginning from
2526 * offset 0. In order to align the objects we have to simply size
2527 * each object to conform to the alignment.
2529 size = ALIGN(size, align);
2530 s->size = size;
2531 if (forced_order >= 0)
2532 order = forced_order;
2533 else
2534 order = calculate_order(size, s->reserved);
2536 if (order < 0)
2537 return 0;
2539 s->allocflags = 0;
2540 if (order)
2541 s->allocflags |= __GFP_COMP;
2543 if (s->flags & SLAB_CACHE_DMA)
2544 s->allocflags |= SLUB_DMA;
2546 if (s->flags & SLAB_RECLAIM_ACCOUNT)
2547 s->allocflags |= __GFP_RECLAIMABLE;
2550 * Determine the number of objects per slab
2552 s->oo = oo_make(order, size, s->reserved);
2553 s->min = oo_make(get_order(size), size, s->reserved);
2554 if (oo_objects(s->oo) > oo_objects(s->max))
2555 s->max = s->oo;
2557 return !!oo_objects(s->oo);
2561 static int kmem_cache_open(struct kmem_cache *s,
2562 const char *name, size_t size,
2563 size_t align, unsigned long flags,
2564 void (*ctor)(void *))
2566 memset(s, 0, kmem_size);
2567 s->name = name;
2568 s->ctor = ctor;
2569 s->objsize = size;
2570 s->align = align;
2571 s->flags = kmem_cache_flags(size, flags, name, ctor);
2572 s->reserved = 0;
2574 if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU))
2575 s->reserved = sizeof(struct rcu_head);
2577 if (!calculate_sizes(s, -1))
2578 goto error;
2579 if (disable_higher_order_debug) {
2581 * Disable debugging flags that store metadata if the min slab
2582 * order increased.
2584 if (get_order(s->size) > get_order(s->objsize)) {
2585 s->flags &= ~DEBUG_METADATA_FLAGS;
2586 s->offset = 0;
2587 if (!calculate_sizes(s, -1))
2588 goto error;
2593 * The larger the object size is, the more pages we want on the partial
2594 * list to avoid pounding the page allocator excessively.
2596 set_min_partial(s, ilog2(s->size));
2597 s->refcount = 1;
2598 #ifdef CONFIG_NUMA
2599 s->remote_node_defrag_ratio = 1000;
2600 #endif
2601 if (!init_kmem_cache_nodes(s))
2602 goto error;
2604 if (alloc_kmem_cache_cpus(s))
2605 return 1;
2607 free_kmem_cache_nodes(s);
2608 error:
2609 if (flags & SLAB_PANIC)
2610 panic("Cannot create slab %s size=%lu realsize=%u "
2611 "order=%u offset=%u flags=%lx\n",
2612 s->name, (unsigned long)size, s->size, oo_order(s->oo),
2613 s->offset, flags);
2614 return 0;
2618 * Determine the size of a slab object
2620 unsigned int kmem_cache_size(struct kmem_cache *s)
2622 return s->objsize;
2624 EXPORT_SYMBOL(kmem_cache_size);
2626 static void list_slab_objects(struct kmem_cache *s, struct page *page,
2627 const char *text)
2629 #ifdef CONFIG_SLUB_DEBUG
2630 void *addr = page_address(page);
2631 void *p;
2632 unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) *
2633 sizeof(long), GFP_ATOMIC);
2634 if (!map)
2635 return;
2636 slab_err(s, page, "%s", text);
2637 slab_lock(page);
2639 get_map(s, page, map);
2640 for_each_object(p, s, addr, page->objects) {
2642 if (!test_bit(slab_index(p, s, addr), map)) {
2643 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
2644 p, p - addr);
2645 print_tracking(s, p);
2648 slab_unlock(page);
2649 kfree(map);
2650 #endif
2654 * Attempt to free all partial slabs on a node.
2656 static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
2658 unsigned long flags;
2659 struct page *page, *h;
2661 spin_lock_irqsave(&n->list_lock, flags);
2662 list_for_each_entry_safe(page, h, &n->partial, lru) {
2663 if (!page->inuse) {
2664 __remove_partial(n, page);
2665 discard_slab(s, page);
2666 } else {
2667 list_slab_objects(s, page,
2668 "Objects remaining on kmem_cache_close()");
2671 spin_unlock_irqrestore(&n->list_lock, flags);
2675 * Release all resources used by a slab cache.
2677 static inline int kmem_cache_close(struct kmem_cache *s)
2679 int node;
2681 flush_all(s);
2682 free_percpu(s->cpu_slab);
2683 /* Attempt to free all objects */
2684 for_each_node_state(node, N_NORMAL_MEMORY) {
2685 struct kmem_cache_node *n = get_node(s, node);
2687 free_partial(s, n);
2688 if (n->nr_partial || slabs_node(s, node))
2689 return 1;
2691 free_kmem_cache_nodes(s);
2692 return 0;
2696 * Close a cache and release the kmem_cache structure
2697 * (must be used for caches created using kmem_cache_create)
2699 void kmem_cache_destroy(struct kmem_cache *s)
2701 down_write(&slub_lock);
2702 s->refcount--;
2703 if (!s->refcount) {
2704 list_del(&s->list);
2705 if (kmem_cache_close(s)) {
2706 printk(KERN_ERR "SLUB %s: %s called for cache that "
2707 "still has objects.\n", s->name, __func__);
2708 dump_stack();
2710 if (s->flags & SLAB_DESTROY_BY_RCU)
2711 rcu_barrier();
2712 sysfs_slab_remove(s);
2714 up_write(&slub_lock);
2716 EXPORT_SYMBOL(kmem_cache_destroy);
2718 /********************************************************************
2719 * Kmalloc subsystem
2720 *******************************************************************/
2722 struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
2723 EXPORT_SYMBOL(kmalloc_caches);
2725 static struct kmem_cache *kmem_cache;
2727 #ifdef CONFIG_ZONE_DMA
2728 static struct kmem_cache *kmalloc_dma_caches[SLUB_PAGE_SHIFT];
2729 #endif
2731 static int __init setup_slub_min_order(char *str)
2733 get_option(&str, &slub_min_order);
2735 return 1;
2738 __setup("slub_min_order=", setup_slub_min_order);
2740 static int __init setup_slub_max_order(char *str)
2742 get_option(&str, &slub_max_order);
2743 slub_max_order = min(slub_max_order, MAX_ORDER - 1);
2745 return 1;
2748 __setup("slub_max_order=", setup_slub_max_order);
2750 static int __init setup_slub_min_objects(char *str)
2752 get_option(&str, &slub_min_objects);
2754 return 1;
2757 __setup("slub_min_objects=", setup_slub_min_objects);
2759 static int __init setup_slub_nomerge(char *str)
2761 slub_nomerge = 1;
2762 return 1;
2765 __setup("slub_nomerge", setup_slub_nomerge);
2767 static struct kmem_cache *__init create_kmalloc_cache(const char *name,
2768 int size, unsigned int flags)
2770 struct kmem_cache *s;
2772 s = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
2775 * This function is called with IRQs disabled during early-boot on
2776 * single CPU so there's no need to take slub_lock here.
2778 if (!kmem_cache_open(s, name, size, ARCH_KMALLOC_MINALIGN,
2779 flags, NULL))
2780 goto panic;
2782 list_add(&s->list, &slab_caches);
2783 return s;
2785 panic:
2786 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2787 return NULL;
2791 * Conversion table for small slabs sizes / 8 to the index in the
2792 * kmalloc array. This is necessary for slabs < 192 since we have non power
2793 * of two cache sizes there. The size of larger slabs can be determined using
2794 * fls.
2796 static s8 size_index[24] = {
2797 3, /* 8 */
2798 4, /* 16 */
2799 5, /* 24 */
2800 5, /* 32 */
2801 6, /* 40 */
2802 6, /* 48 */
2803 6, /* 56 */
2804 6, /* 64 */
2805 1, /* 72 */
2806 1, /* 80 */
2807 1, /* 88 */
2808 1, /* 96 */
2809 7, /* 104 */
2810 7, /* 112 */
2811 7, /* 120 */
2812 7, /* 128 */
2813 2, /* 136 */
2814 2, /* 144 */
2815 2, /* 152 */
2816 2, /* 160 */
2817 2, /* 168 */
2818 2, /* 176 */
2819 2, /* 184 */
2820 2 /* 192 */
2823 static inline int size_index_elem(size_t bytes)
2825 return (bytes - 1) / 8;
2828 static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2830 int index;
2832 if (size <= 192) {
2833 if (!size)
2834 return ZERO_SIZE_PTR;
2836 index = size_index[size_index_elem(size)];
2837 } else
2838 index = fls(size - 1);
2840 #ifdef CONFIG_ZONE_DMA
2841 if (unlikely((flags & SLUB_DMA)))
2842 return kmalloc_dma_caches[index];
2844 #endif
2845 return kmalloc_caches[index];
2848 void *__kmalloc(size_t size, gfp_t flags)
2850 struct kmem_cache *s;
2851 void *ret;
2853 if (unlikely(size > SLUB_MAX_SIZE))
2854 return kmalloc_large(size, flags);
2856 s = get_slab(size, flags);
2858 if (unlikely(ZERO_OR_NULL_PTR(s)))
2859 return s;
2861 ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_);
2863 trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
2865 return ret;
2867 EXPORT_SYMBOL(__kmalloc);
2869 #ifdef CONFIG_NUMA
2870 static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
2872 struct page *page;
2873 void *ptr = NULL;
2875 flags |= __GFP_COMP | __GFP_NOTRACK;
2876 page = alloc_pages_node(node, flags, get_order(size));
2877 if (page)
2878 ptr = page_address(page);
2880 kmemleak_alloc(ptr, size, 1, flags);
2881 return ptr;
2884 void *__kmalloc_node(size_t size, gfp_t flags, int node)
2886 struct kmem_cache *s;
2887 void *ret;
2889 if (unlikely(size > SLUB_MAX_SIZE)) {
2890 ret = kmalloc_large_node(size, flags, node);
2892 trace_kmalloc_node(_RET_IP_, ret,
2893 size, PAGE_SIZE << get_order(size),
2894 flags, node);
2896 return ret;
2899 s = get_slab(size, flags);
2901 if (unlikely(ZERO_OR_NULL_PTR(s)))
2902 return s;
2904 ret = slab_alloc(s, flags, node, _RET_IP_);
2906 trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
2908 return ret;
2910 EXPORT_SYMBOL(__kmalloc_node);
2911 #endif
2913 size_t ksize(const void *object)
2915 struct page *page;
2917 if (unlikely(object == ZERO_SIZE_PTR))
2918 return 0;
2920 page = virt_to_head_page(object);
2922 if (unlikely(!PageSlab(page))) {
2923 WARN_ON(!PageCompound(page));
2924 return PAGE_SIZE << compound_order(page);
2927 return slab_ksize(page->slab);
2929 EXPORT_SYMBOL(ksize);
2931 void kfree(const void *x)
2933 struct page *page;
2934 void *object = (void *)x;
2936 trace_kfree(_RET_IP_, x);
2938 if (unlikely(ZERO_OR_NULL_PTR(x)))
2939 return;
2941 page = virt_to_head_page(x);
2942 if (unlikely(!PageSlab(page))) {
2943 BUG_ON(!PageCompound(page));
2944 kmemleak_free(x);
2945 put_page(page);
2946 return;
2948 slab_free(page->slab, page, object, _RET_IP_);
2950 EXPORT_SYMBOL(kfree);
2953 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2954 * the remaining slabs by the number of items in use. The slabs with the
2955 * most items in use come first. New allocations will then fill those up
2956 * and thus they can be removed from the partial lists.
2958 * The slabs with the least items are placed last. This results in them
2959 * being allocated from last increasing the chance that the last objects
2960 * are freed in them.
2962 int kmem_cache_shrink(struct kmem_cache *s)
2964 int node;
2965 int i;
2966 struct kmem_cache_node *n;
2967 struct page *page;
2968 struct page *t;
2969 int objects = oo_objects(s->max);
2970 struct list_head *slabs_by_inuse =
2971 kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
2972 unsigned long flags;
2974 if (!slabs_by_inuse)
2975 return -ENOMEM;
2977 flush_all(s);
2978 for_each_node_state(node, N_NORMAL_MEMORY) {
2979 n = get_node(s, node);
2981 if (!n->nr_partial)
2982 continue;
2984 for (i = 0; i < objects; i++)
2985 INIT_LIST_HEAD(slabs_by_inuse + i);
2987 spin_lock_irqsave(&n->list_lock, flags);
2990 * Build lists indexed by the items in use in each slab.
2992 * Note that concurrent frees may occur while we hold the
2993 * list_lock. page->inuse here is the upper limit.
2995 list_for_each_entry_safe(page, t, &n->partial, lru) {
2996 if (!page->inuse && slab_trylock(page)) {
2998 * Must hold slab lock here because slab_free
2999 * may have freed the last object and be
3000 * waiting to release the slab.
3002 __remove_partial(n, page);
3003 slab_unlock(page);
3004 discard_slab(s, page);
3005 } else {
3006 list_move(&page->lru,
3007 slabs_by_inuse + page->inuse);
3012 * Rebuild the partial list with the slabs filled up most
3013 * first and the least used slabs at the end.
3015 for (i = objects - 1; i >= 0; i--)
3016 list_splice(slabs_by_inuse + i, n->partial.prev);
3018 spin_unlock_irqrestore(&n->list_lock, flags);
3021 kfree(slabs_by_inuse);
3022 return 0;
3024 EXPORT_SYMBOL(kmem_cache_shrink);
3026 #if defined(CONFIG_MEMORY_HOTPLUG)
3027 static int slab_mem_going_offline_callback(void *arg)
3029 struct kmem_cache *s;
3031 down_read(&slub_lock);
3032 list_for_each_entry(s, &slab_caches, list)
3033 kmem_cache_shrink(s);
3034 up_read(&slub_lock);
3036 return 0;
3039 static void slab_mem_offline_callback(void *arg)
3041 struct kmem_cache_node *n;
3042 struct kmem_cache *s;
3043 struct memory_notify *marg = arg;
3044 int offline_node;
3046 offline_node = marg->status_change_nid;
3049 * If the node still has available memory. we need kmem_cache_node
3050 * for it yet.
3052 if (offline_node < 0)
3053 return;
3055 down_read(&slub_lock);
3056 list_for_each_entry(s, &slab_caches, list) {
3057 n = get_node(s, offline_node);
3058 if (n) {
3060 * if n->nr_slabs > 0, slabs still exist on the node
3061 * that is going down. We were unable to free them,
3062 * and offline_pages() function shouldn't call this
3063 * callback. So, we must fail.
3065 BUG_ON(slabs_node(s, offline_node));
3067 s->node[offline_node] = NULL;
3068 kmem_cache_free(kmem_cache_node, n);
3071 up_read(&slub_lock);
3074 static int slab_mem_going_online_callback(void *arg)
3076 struct kmem_cache_node *n;
3077 struct kmem_cache *s;
3078 struct memory_notify *marg = arg;
3079 int nid = marg->status_change_nid;
3080 int ret = 0;
3083 * If the node's memory is already available, then kmem_cache_node is
3084 * already created. Nothing to do.
3086 if (nid < 0)
3087 return 0;
3090 * We are bringing a node online. No memory is available yet. We must
3091 * allocate a kmem_cache_node structure in order to bring the node
3092 * online.
3094 down_read(&slub_lock);
3095 list_for_each_entry(s, &slab_caches, list) {
3097 * XXX: kmem_cache_alloc_node will fallback to other nodes
3098 * since memory is not yet available from the node that
3099 * is brought up.
3101 n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
3102 if (!n) {
3103 ret = -ENOMEM;
3104 goto out;
3106 init_kmem_cache_node(n, s);
3107 s->node[nid] = n;
3109 out:
3110 up_read(&slub_lock);
3111 return ret;
3114 static int slab_memory_callback(struct notifier_block *self,
3115 unsigned long action, void *arg)
3117 int ret = 0;
3119 switch (action) {
3120 case MEM_GOING_ONLINE:
3121 ret = slab_mem_going_online_callback(arg);
3122 break;
3123 case MEM_GOING_OFFLINE:
3124 ret = slab_mem_going_offline_callback(arg);
3125 break;
3126 case MEM_OFFLINE:
3127 case MEM_CANCEL_ONLINE:
3128 slab_mem_offline_callback(arg);
3129 break;
3130 case MEM_ONLINE:
3131 case MEM_CANCEL_OFFLINE:
3132 break;
3134 if (ret)
3135 ret = notifier_from_errno(ret);
3136 else
3137 ret = NOTIFY_OK;
3138 return ret;
3141 #endif /* CONFIG_MEMORY_HOTPLUG */
3143 /********************************************************************
3144 * Basic setup of slabs
3145 *******************************************************************/
3148 * Used for early kmem_cache structures that were allocated using
3149 * the page allocator
3152 static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)
3154 int node;
3156 list_add(&s->list, &slab_caches);
3157 s->refcount = -1;
3159 for_each_node_state(node, N_NORMAL_MEMORY) {
3160 struct kmem_cache_node *n = get_node(s, node);
3161 struct page *p;
3163 if (n) {
3164 list_for_each_entry(p, &n->partial, lru)
3165 p->slab = s;
3167 #ifdef CONFIG_SLUB_DEBUG
3168 list_for_each_entry(p, &n->full, lru)
3169 p->slab = s;
3170 #endif
3175 void __init kmem_cache_init(void)
3177 int i;
3178 int caches = 0;
3179 struct kmem_cache *temp_kmem_cache;
3180 int order;
3181 struct kmem_cache *temp_kmem_cache_node;
3182 unsigned long kmalloc_size;
3184 kmem_size = offsetof(struct kmem_cache, node) +
3185 nr_node_ids * sizeof(struct kmem_cache_node *);
3187 /* Allocate two kmem_caches from the page allocator */
3188 kmalloc_size = ALIGN(kmem_size, cache_line_size());
3189 order = get_order(2 * kmalloc_size);
3190 kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order);
3193 * Must first have the slab cache available for the allocations of the
3194 * struct kmem_cache_node's. There is special bootstrap code in
3195 * kmem_cache_open for slab_state == DOWN.
3197 kmem_cache_node = (void *)kmem_cache + kmalloc_size;
3199 kmem_cache_open(kmem_cache_node, "kmem_cache_node",
3200 sizeof(struct kmem_cache_node),
3201 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
3203 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
3205 /* Able to allocate the per node structures */
3206 slab_state = PARTIAL;
3208 temp_kmem_cache = kmem_cache;
3209 kmem_cache_open(kmem_cache, "kmem_cache", kmem_size,
3210 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
3211 kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
3212 memcpy(kmem_cache, temp_kmem_cache, kmem_size);
3215 * Allocate kmem_cache_node properly from the kmem_cache slab.
3216 * kmem_cache_node is separately allocated so no need to
3217 * update any list pointers.
3219 temp_kmem_cache_node = kmem_cache_node;
3221 kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
3222 memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size);
3224 kmem_cache_bootstrap_fixup(kmem_cache_node);
3226 caches++;
3227 kmem_cache_bootstrap_fixup(kmem_cache);
3228 caches++;
3229 /* Free temporary boot structure */
3230 free_pages((unsigned long)temp_kmem_cache, order);
3232 /* Now we can use the kmem_cache to allocate kmalloc slabs */
3235 * Patch up the size_index table if we have strange large alignment
3236 * requirements for the kmalloc array. This is only the case for
3237 * MIPS it seems. The standard arches will not generate any code here.
3239 * Largest permitted alignment is 256 bytes due to the way we
3240 * handle the index determination for the smaller caches.
3242 * Make sure that nothing crazy happens if someone starts tinkering
3243 * around with ARCH_KMALLOC_MINALIGN
3245 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
3246 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
3248 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
3249 int elem = size_index_elem(i);
3250 if (elem >= ARRAY_SIZE(size_index))
3251 break;
3252 size_index[elem] = KMALLOC_SHIFT_LOW;
3255 if (KMALLOC_MIN_SIZE == 64) {
3257 * The 96 byte size cache is not used if the alignment
3258 * is 64 byte.
3260 for (i = 64 + 8; i <= 96; i += 8)
3261 size_index[size_index_elem(i)] = 7;
3262 } else if (KMALLOC_MIN_SIZE == 128) {
3264 * The 192 byte sized cache is not used if the alignment
3265 * is 128 byte. Redirect kmalloc to use the 256 byte cache
3266 * instead.
3268 for (i = 128 + 8; i <= 192; i += 8)
3269 size_index[size_index_elem(i)] = 8;
3272 /* Caches that are not of the two-to-the-power-of size */
3273 if (KMALLOC_MIN_SIZE <= 32) {
3274 kmalloc_caches[1] = create_kmalloc_cache("kmalloc-96", 96, 0);
3275 caches++;
3278 if (KMALLOC_MIN_SIZE <= 64) {
3279 kmalloc_caches[2] = create_kmalloc_cache("kmalloc-192", 192, 0);
3280 caches++;
3283 for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
3284 kmalloc_caches[i] = create_kmalloc_cache("kmalloc", 1 << i, 0);
3285 caches++;
3288 slab_state = UP;
3290 /* Provide the correct kmalloc names now that the caches are up */
3291 if (KMALLOC_MIN_SIZE <= 32) {
3292 kmalloc_caches[1]->name = kstrdup(kmalloc_caches[1]->name, GFP_NOWAIT);
3293 BUG_ON(!kmalloc_caches[1]->name);
3296 if (KMALLOC_MIN_SIZE <= 64) {
3297 kmalloc_caches[2]->name = kstrdup(kmalloc_caches[2]->name, GFP_NOWAIT);
3298 BUG_ON(!kmalloc_caches[2]->name);
3301 for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
3302 char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i);
3304 BUG_ON(!s);
3305 kmalloc_caches[i]->name = s;
3308 #ifdef CONFIG_SMP
3309 register_cpu_notifier(&slab_notifier);
3310 #endif
3312 #ifdef CONFIG_ZONE_DMA
3313 for (i = 0; i < SLUB_PAGE_SHIFT; i++) {
3314 struct kmem_cache *s = kmalloc_caches[i];
3316 if (s && s->size) {
3317 char *name = kasprintf(GFP_NOWAIT,
3318 "dma-kmalloc-%d", s->objsize);
3320 BUG_ON(!name);
3321 kmalloc_dma_caches[i] = create_kmalloc_cache(name,
3322 s->objsize, SLAB_CACHE_DMA);
3325 #endif
3326 printk(KERN_INFO
3327 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
3328 " CPUs=%d, Nodes=%d\n",
3329 caches, cache_line_size(),
3330 slub_min_order, slub_max_order, slub_min_objects,
3331 nr_cpu_ids, nr_node_ids);
3334 void __init kmem_cache_init_late(void)
3339 * Find a mergeable slab cache
3341 static int slab_unmergeable(struct kmem_cache *s)
3343 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
3344 return 1;
3346 if (s->ctor)
3347 return 1;
3350 * We may have set a slab to be unmergeable during bootstrap.
3352 if (s->refcount < 0)
3353 return 1;
3355 return 0;
3358 static struct kmem_cache *find_mergeable(size_t size,
3359 size_t align, unsigned long flags, const char *name,
3360 void (*ctor)(void *))
3362 struct kmem_cache *s;
3364 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
3365 return NULL;
3367 if (ctor)
3368 return NULL;
3370 size = ALIGN(size, sizeof(void *));
3371 align = calculate_alignment(flags, align, size);
3372 size = ALIGN(size, align);
3373 flags = kmem_cache_flags(size, flags, name, NULL);
3375 list_for_each_entry(s, &slab_caches, list) {
3376 if (slab_unmergeable(s))
3377 continue;
3379 if (size > s->size)
3380 continue;
3382 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
3383 continue;
3385 * Check if alignment is compatible.
3386 * Courtesy of Adrian Drzewiecki
3388 if ((s->size & ~(align - 1)) != s->size)
3389 continue;
3391 if (s->size - size >= sizeof(void *))
3392 continue;
3394 return s;
3396 return NULL;
3399 struct kmem_cache *kmem_cache_create(const char *name, size_t size,
3400 size_t align, unsigned long flags, void (*ctor)(void *))
3402 struct kmem_cache *s;
3403 char *n;
3405 if (WARN_ON(!name))
3406 return NULL;
3408 down_write(&slub_lock);
3409 s = find_mergeable(size, align, flags, name, ctor);
3410 if (s) {
3411 s->refcount++;
3413 * Adjust the object sizes so that we clear
3414 * the complete object on kzalloc.
3416 s->objsize = max(s->objsize, (int)size);
3417 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
3419 if (sysfs_slab_alias(s, name)) {
3420 s->refcount--;
3421 goto err;
3423 up_write(&slub_lock);
3424 return s;
3427 n = kstrdup(name, GFP_KERNEL);
3428 if (!n)
3429 goto err;
3431 s = kmalloc(kmem_size, GFP_KERNEL);
3432 if (s) {
3433 if (kmem_cache_open(s, n,
3434 size, align, flags, ctor)) {
3435 list_add(&s->list, &slab_caches);
3436 if (sysfs_slab_add(s)) {
3437 list_del(&s->list);
3438 kfree(n);
3439 kfree(s);
3440 goto err;
3442 up_write(&slub_lock);
3443 return s;
3445 kfree(n);
3446 kfree(s);
3448 err:
3449 up_write(&slub_lock);
3451 if (flags & SLAB_PANIC)
3452 panic("Cannot create slabcache %s\n", name);
3453 else
3454 s = NULL;
3455 return s;
3457 EXPORT_SYMBOL(kmem_cache_create);
3459 #ifdef CONFIG_SMP
3461 * Use the cpu notifier to insure that the cpu slabs are flushed when
3462 * necessary.
3464 static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3465 unsigned long action, void *hcpu)
3467 long cpu = (long)hcpu;
3468 struct kmem_cache *s;
3469 unsigned long flags;
3471 switch (action) {
3472 case CPU_UP_CANCELED:
3473 case CPU_UP_CANCELED_FROZEN:
3474 case CPU_DEAD:
3475 case CPU_DEAD_FROZEN:
3476 down_read(&slub_lock);
3477 list_for_each_entry(s, &slab_caches, list) {
3478 local_irq_save(flags);
3479 __flush_cpu_slab(s, cpu);
3480 local_irq_restore(flags);
3482 up_read(&slub_lock);
3483 break;
3484 default:
3485 break;
3487 return NOTIFY_OK;
3490 static struct notifier_block __cpuinitdata slab_notifier = {
3491 .notifier_call = slab_cpuup_callback
3494 #endif
3496 void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
3498 struct kmem_cache *s;
3499 void *ret;
3501 if (unlikely(size > SLUB_MAX_SIZE))
3502 return kmalloc_large(size, gfpflags);
3504 s = get_slab(size, gfpflags);
3506 if (unlikely(ZERO_OR_NULL_PTR(s)))
3507 return s;
3509 ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller);
3511 /* Honor the call site pointer we received. */
3512 trace_kmalloc(caller, ret, size, s->size, gfpflags);
3514 return ret;
3517 #ifdef CONFIG_NUMA
3518 void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3519 int node, unsigned long caller)
3521 struct kmem_cache *s;
3522 void *ret;
3524 if (unlikely(size > SLUB_MAX_SIZE)) {
3525 ret = kmalloc_large_node(size, gfpflags, node);
3527 trace_kmalloc_node(caller, ret,
3528 size, PAGE_SIZE << get_order(size),
3529 gfpflags, node);
3531 return ret;
3534 s = get_slab(size, gfpflags);
3536 if (unlikely(ZERO_OR_NULL_PTR(s)))
3537 return s;
3539 ret = slab_alloc(s, gfpflags, node, caller);
3541 /* Honor the call site pointer we received. */
3542 trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
3544 return ret;
3546 #endif
3548 #ifdef CONFIG_SYSFS
3549 static int count_inuse(struct page *page)
3551 return page->inuse;
3554 static int count_total(struct page *page)
3556 return page->objects;
3558 #endif
3560 #ifdef CONFIG_SLUB_DEBUG
3561 static int validate_slab(struct kmem_cache *s, struct page *page,
3562 unsigned long *map)
3564 void *p;
3565 void *addr = page_address(page);
3567 if (!check_slab(s, page) ||
3568 !on_freelist(s, page, NULL))
3569 return 0;
3571 /* Now we know that a valid freelist exists */
3572 bitmap_zero(map, page->objects);
3574 get_map(s, page, map);
3575 for_each_object(p, s, addr, page->objects) {
3576 if (test_bit(slab_index(p, s, addr), map))
3577 if (!check_object(s, page, p, SLUB_RED_INACTIVE))
3578 return 0;
3581 for_each_object(p, s, addr, page->objects)
3582 if (!test_bit(slab_index(p, s, addr), map))
3583 if (!check_object(s, page, p, SLUB_RED_ACTIVE))
3584 return 0;
3585 return 1;
3588 static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3589 unsigned long *map)
3591 if (slab_trylock(page)) {
3592 validate_slab(s, page, map);
3593 slab_unlock(page);
3594 } else
3595 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3596 s->name, page);
3599 static int validate_slab_node(struct kmem_cache *s,
3600 struct kmem_cache_node *n, unsigned long *map)
3602 unsigned long count = 0;
3603 struct page *page;
3604 unsigned long flags;
3606 spin_lock_irqsave(&n->list_lock, flags);
3608 list_for_each_entry(page, &n->partial, lru) {
3609 validate_slab_slab(s, page, map);
3610 count++;
3612 if (count != n->nr_partial)
3613 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3614 "counter=%ld\n", s->name, count, n->nr_partial);
3616 if (!(s->flags & SLAB_STORE_USER))
3617 goto out;
3619 list_for_each_entry(page, &n->full, lru) {
3620 validate_slab_slab(s, page, map);
3621 count++;
3623 if (count != atomic_long_read(&n->nr_slabs))
3624 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3625 "counter=%ld\n", s->name, count,
3626 atomic_long_read(&n->nr_slabs));
3628 out:
3629 spin_unlock_irqrestore(&n->list_lock, flags);
3630 return count;
3633 static long validate_slab_cache(struct kmem_cache *s)
3635 int node;
3636 unsigned long count = 0;
3637 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
3638 sizeof(unsigned long), GFP_KERNEL);
3640 if (!map)
3641 return -ENOMEM;
3643 flush_all(s);
3644 for_each_node_state(node, N_NORMAL_MEMORY) {
3645 struct kmem_cache_node *n = get_node(s, node);
3647 count += validate_slab_node(s, n, map);
3649 kfree(map);
3650 return count;
3653 * Generate lists of code addresses where slabcache objects are allocated
3654 * and freed.
3657 struct location {
3658 unsigned long count;
3659 unsigned long addr;
3660 long long sum_time;
3661 long min_time;
3662 long max_time;
3663 long min_pid;
3664 long max_pid;
3665 DECLARE_BITMAP(cpus, NR_CPUS);
3666 nodemask_t nodes;
3669 struct loc_track {
3670 unsigned long max;
3671 unsigned long count;
3672 struct location *loc;
3675 static void free_loc_track(struct loc_track *t)
3677 if (t->max)
3678 free_pages((unsigned long)t->loc,
3679 get_order(sizeof(struct location) * t->max));
3682 static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
3684 struct location *l;
3685 int order;
3687 order = get_order(sizeof(struct location) * max);
3689 l = (void *)__get_free_pages(flags, order);
3690 if (!l)
3691 return 0;
3693 if (t->count) {
3694 memcpy(l, t->loc, sizeof(struct location) * t->count);
3695 free_loc_track(t);
3697 t->max = max;
3698 t->loc = l;
3699 return 1;
3702 static int add_location(struct loc_track *t, struct kmem_cache *s,
3703 const struct track *track)
3705 long start, end, pos;
3706 struct location *l;
3707 unsigned long caddr;
3708 unsigned long age = jiffies - track->when;
3710 start = -1;
3711 end = t->count;
3713 for ( ; ; ) {
3714 pos = start + (end - start + 1) / 2;
3717 * There is nothing at "end". If we end up there
3718 * we need to add something to before end.
3720 if (pos == end)
3721 break;
3723 caddr = t->loc[pos].addr;
3724 if (track->addr == caddr) {
3726 l = &t->loc[pos];
3727 l->count++;
3728 if (track->when) {
3729 l->sum_time += age;
3730 if (age < l->min_time)
3731 l->min_time = age;
3732 if (age > l->max_time)
3733 l->max_time = age;
3735 if (track->pid < l->min_pid)
3736 l->min_pid = track->pid;
3737 if (track->pid > l->max_pid)
3738 l->max_pid = track->pid;
3740 cpumask_set_cpu(track->cpu,
3741 to_cpumask(l->cpus));
3743 node_set(page_to_nid(virt_to_page(track)), l->nodes);
3744 return 1;
3747 if (track->addr < caddr)
3748 end = pos;
3749 else
3750 start = pos;
3754 * Not found. Insert new tracking element.
3756 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
3757 return 0;
3759 l = t->loc + pos;
3760 if (pos < t->count)
3761 memmove(l + 1, l,
3762 (t->count - pos) * sizeof(struct location));
3763 t->count++;
3764 l->count = 1;
3765 l->addr = track->addr;
3766 l->sum_time = age;
3767 l->min_time = age;
3768 l->max_time = age;
3769 l->min_pid = track->pid;
3770 l->max_pid = track->pid;
3771 cpumask_clear(to_cpumask(l->cpus));
3772 cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
3773 nodes_clear(l->nodes);
3774 node_set(page_to_nid(virt_to_page(track)), l->nodes);
3775 return 1;
3778 static void process_slab(struct loc_track *t, struct kmem_cache *s,
3779 struct page *page, enum track_item alloc,
3780 unsigned long *map)
3782 void *addr = page_address(page);
3783 void *p;
3785 bitmap_zero(map, page->objects);
3786 get_map(s, page, map);
3788 for_each_object(p, s, addr, page->objects)
3789 if (!test_bit(slab_index(p, s, addr), map))
3790 add_location(t, s, get_track(s, p, alloc));
3793 static int list_locations(struct kmem_cache *s, char *buf,
3794 enum track_item alloc)
3796 int len = 0;
3797 unsigned long i;
3798 struct loc_track t = { 0, 0, NULL };
3799 int node;
3800 unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
3801 sizeof(unsigned long), GFP_KERNEL);
3803 if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
3804 GFP_TEMPORARY)) {
3805 kfree(map);
3806 return sprintf(buf, "Out of memory\n");
3808 /* Push back cpu slabs */
3809 flush_all(s);
3811 for_each_node_state(node, N_NORMAL_MEMORY) {
3812 struct kmem_cache_node *n = get_node(s, node);
3813 unsigned long flags;
3814 struct page *page;
3816 if (!atomic_long_read(&n->nr_slabs))
3817 continue;
3819 spin_lock_irqsave(&n->list_lock, flags);
3820 list_for_each_entry(page, &n->partial, lru)
3821 process_slab(&t, s, page, alloc, map);
3822 list_for_each_entry(page, &n->full, lru)
3823 process_slab(&t, s, page, alloc, map);
3824 spin_unlock_irqrestore(&n->list_lock, flags);
3827 for (i = 0; i < t.count; i++) {
3828 struct location *l = &t.loc[i];
3830 if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100)
3831 break;
3832 len += sprintf(buf + len, "%7ld ", l->count);
3834 if (l->addr)
3835 len += sprintf(buf + len, "%pS", (void *)l->addr);
3836 else
3837 len += sprintf(buf + len, "<not-available>");
3839 if (l->sum_time != l->min_time) {
3840 len += sprintf(buf + len, " age=%ld/%ld/%ld",
3841 l->min_time,
3842 (long)div_u64(l->sum_time, l->count),
3843 l->max_time);
3844 } else
3845 len += sprintf(buf + len, " age=%ld",
3846 l->min_time);
3848 if (l->min_pid != l->max_pid)
3849 len += sprintf(buf + len, " pid=%ld-%ld",
3850 l->min_pid, l->max_pid);
3851 else
3852 len += sprintf(buf + len, " pid=%ld",
3853 l->min_pid);
3855 if (num_online_cpus() > 1 &&
3856 !cpumask_empty(to_cpumask(l->cpus)) &&
3857 len < PAGE_SIZE - 60) {
3858 len += sprintf(buf + len, " cpus=");
3859 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
3860 to_cpumask(l->cpus));
3863 if (nr_online_nodes > 1 && !nodes_empty(l->nodes) &&
3864 len < PAGE_SIZE - 60) {
3865 len += sprintf(buf + len, " nodes=");
3866 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
3867 l->nodes);
3870 len += sprintf(buf + len, "\n");
3873 free_loc_track(&t);
3874 kfree(map);
3875 if (!t.count)
3876 len += sprintf(buf, "No data\n");
3877 return len;
3879 #endif
3881 #ifdef SLUB_RESILIENCY_TEST
3882 static void resiliency_test(void)
3884 u8 *p;
3886 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || SLUB_PAGE_SHIFT < 10);
3888 printk(KERN_ERR "SLUB resiliency testing\n");
3889 printk(KERN_ERR "-----------------------\n");
3890 printk(KERN_ERR "A. Corruption after allocation\n");
3892 p = kzalloc(16, GFP_KERNEL);
3893 p[16] = 0x12;
3894 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3895 " 0x12->0x%p\n\n", p + 16);
3897 validate_slab_cache(kmalloc_caches[4]);
3899 /* Hmmm... The next two are dangerous */
3900 p = kzalloc(32, GFP_KERNEL);
3901 p[32 + sizeof(void *)] = 0x34;
3902 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
3903 " 0x34 -> -0x%p\n", p);
3904 printk(KERN_ERR
3905 "If allocated object is overwritten then not detectable\n\n");
3907 validate_slab_cache(kmalloc_caches[5]);
3908 p = kzalloc(64, GFP_KERNEL);
3909 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3910 *p = 0x56;
3911 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3913 printk(KERN_ERR
3914 "If allocated object is overwritten then not detectable\n\n");
3915 validate_slab_cache(kmalloc_caches[6]);
3917 printk(KERN_ERR "\nB. Corruption after free\n");
3918 p = kzalloc(128, GFP_KERNEL);
3919 kfree(p);
3920 *p = 0x78;
3921 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3922 validate_slab_cache(kmalloc_caches[7]);
3924 p = kzalloc(256, GFP_KERNEL);
3925 kfree(p);
3926 p[50] = 0x9a;
3927 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3929 validate_slab_cache(kmalloc_caches[8]);
3931 p = kzalloc(512, GFP_KERNEL);
3932 kfree(p);
3933 p[512] = 0xab;
3934 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3935 validate_slab_cache(kmalloc_caches[9]);
3937 #else
3938 #ifdef CONFIG_SYSFS
3939 static void resiliency_test(void) {};
3940 #endif
3941 #endif
3943 #ifdef CONFIG_SYSFS
3944 enum slab_stat_type {
3945 SL_ALL, /* All slabs */
3946 SL_PARTIAL, /* Only partially allocated slabs */
3947 SL_CPU, /* Only slabs used for cpu caches */
3948 SL_OBJECTS, /* Determine allocated objects not slabs */
3949 SL_TOTAL /* Determine object capacity not slabs */
3952 #define SO_ALL (1 << SL_ALL)
3953 #define SO_PARTIAL (1 << SL_PARTIAL)
3954 #define SO_CPU (1 << SL_CPU)
3955 #define SO_OBJECTS (1 << SL_OBJECTS)
3956 #define SO_TOTAL (1 << SL_TOTAL)
3958 static ssize_t show_slab_objects(struct kmem_cache *s,
3959 char *buf, unsigned long flags)
3961 unsigned long total = 0;
3962 int node;
3963 int x;
3964 unsigned long *nodes;
3965 unsigned long *per_cpu;
3967 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
3968 if (!nodes)
3969 return -ENOMEM;
3970 per_cpu = nodes + nr_node_ids;
3972 if (flags & SO_CPU) {
3973 int cpu;
3975 for_each_possible_cpu(cpu) {
3976 struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
3978 if (!c || c->node < 0)
3979 continue;
3981 if (c->page) {
3982 if (flags & SO_TOTAL)
3983 x = c->page->objects;
3984 else if (flags & SO_OBJECTS)
3985 x = c->page->inuse;
3986 else
3987 x = 1;
3989 total += x;
3990 nodes[c->node] += x;
3992 per_cpu[c->node]++;
3996 lock_memory_hotplug();
3997 #ifdef CONFIG_SLUB_DEBUG
3998 if (flags & SO_ALL) {
3999 for_each_node_state(node, N_NORMAL_MEMORY) {
4000 struct kmem_cache_node *n = get_node(s, node);
4002 if (flags & SO_TOTAL)
4003 x = atomic_long_read(&n->total_objects);
4004 else if (flags & SO_OBJECTS)
4005 x = atomic_long_read(&n->total_objects) -
4006 count_partial(n, count_free);
4008 else
4009 x = atomic_long_read(&n->nr_slabs);
4010 total += x;
4011 nodes[node] += x;
4014 } else
4015 #endif
4016 if (flags & SO_PARTIAL) {
4017 for_each_node_state(node, N_NORMAL_MEMORY) {
4018 struct kmem_cache_node *n = get_node(s, node);
4020 if (flags & SO_TOTAL)
4021 x = count_partial(n, count_total);
4022 else if (flags & SO_OBJECTS)
4023 x = count_partial(n, count_inuse);
4024 else
4025 x = n->nr_partial;
4026 total += x;
4027 nodes[node] += x;
4030 x = sprintf(buf, "%lu", total);
4031 #ifdef CONFIG_NUMA
4032 for_each_node_state(node, N_NORMAL_MEMORY)
4033 if (nodes[node])
4034 x += sprintf(buf + x, " N%d=%lu",
4035 node, nodes[node]);
4036 #endif
4037 unlock_memory_hotplug();
4038 kfree(nodes);
4039 return x + sprintf(buf + x, "\n");
4042 #ifdef CONFIG_SLUB_DEBUG
4043 static int any_slab_objects(struct kmem_cache *s)
4045 int node;
4047 for_each_online_node(node) {
4048 struct kmem_cache_node *n = get_node(s, node);
4050 if (!n)
4051 continue;
4053 if (atomic_long_read(&n->total_objects))
4054 return 1;
4056 return 0;
4058 #endif
4060 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
4061 #define to_slab(n) container_of(n, struct kmem_cache, kobj);
4063 struct slab_attribute {
4064 struct attribute attr;
4065 ssize_t (*show)(struct kmem_cache *s, char *buf);
4066 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
4069 #define SLAB_ATTR_RO(_name) \
4070 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
4072 #define SLAB_ATTR(_name) \
4073 static struct slab_attribute _name##_attr = \
4074 __ATTR(_name, 0644, _name##_show, _name##_store)
4076 static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
4078 return sprintf(buf, "%d\n", s->size);
4080 SLAB_ATTR_RO(slab_size);
4082 static ssize_t align_show(struct kmem_cache *s, char *buf)
4084 return sprintf(buf, "%d\n", s->align);
4086 SLAB_ATTR_RO(align);
4088 static ssize_t object_size_show(struct kmem_cache *s, char *buf)
4090 return sprintf(buf, "%d\n", s->objsize);
4092 SLAB_ATTR_RO(object_size);
4094 static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
4096 return sprintf(buf, "%d\n", oo_objects(s->oo));
4098 SLAB_ATTR_RO(objs_per_slab);
4100 static ssize_t order_store(struct kmem_cache *s,
4101 const char *buf, size_t length)
4103 unsigned long order;
4104 int err;
4106 err = strict_strtoul(buf, 10, &order);
4107 if (err)
4108 return err;
4110 if (order > slub_max_order || order < slub_min_order)
4111 return -EINVAL;
4113 calculate_sizes(s, order);
4114 return length;
4117 static ssize_t order_show(struct kmem_cache *s, char *buf)
4119 return sprintf(buf, "%d\n", oo_order(s->oo));
4121 SLAB_ATTR(order);
4123 static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
4125 return sprintf(buf, "%lu\n", s->min_partial);
4128 static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
4129 size_t length)
4131 unsigned long min;
4132 int err;
4134 err = strict_strtoul(buf, 10, &min);
4135 if (err)
4136 return err;
4138 set_min_partial(s, min);
4139 return length;
4141 SLAB_ATTR(min_partial);
4143 static ssize_t ctor_show(struct kmem_cache *s, char *buf)
4145 if (!s->ctor)
4146 return 0;
4147 return sprintf(buf, "%pS\n", s->ctor);
4149 SLAB_ATTR_RO(ctor);
4151 static ssize_t aliases_show(struct kmem_cache *s, char *buf)
4153 return sprintf(buf, "%d\n", s->refcount - 1);
4155 SLAB_ATTR_RO(aliases);
4157 static ssize_t partial_show(struct kmem_cache *s, char *buf)
4159 return show_slab_objects(s, buf, SO_PARTIAL);
4161 SLAB_ATTR_RO(partial);
4163 static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
4165 return show_slab_objects(s, buf, SO_CPU);
4167 SLAB_ATTR_RO(cpu_slabs);
4169 static ssize_t objects_show(struct kmem_cache *s, char *buf)
4171 return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
4173 SLAB_ATTR_RO(objects);
4175 static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
4177 return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
4179 SLAB_ATTR_RO(objects_partial);
4181 static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
4183 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
4186 static ssize_t reclaim_account_store(struct kmem_cache *s,
4187 const char *buf, size_t length)
4189 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
4190 if (buf[0] == '1')
4191 s->flags |= SLAB_RECLAIM_ACCOUNT;
4192 return length;
4194 SLAB_ATTR(reclaim_account);
4196 static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
4198 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
4200 SLAB_ATTR_RO(hwcache_align);
4202 #ifdef CONFIG_ZONE_DMA
4203 static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
4205 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
4207 SLAB_ATTR_RO(cache_dma);
4208 #endif
4210 static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
4212 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
4214 SLAB_ATTR_RO(destroy_by_rcu);
4216 static ssize_t reserved_show(struct kmem_cache *s, char *buf)
4218 return sprintf(buf, "%d\n", s->reserved);
4220 SLAB_ATTR_RO(reserved);
4222 #ifdef CONFIG_SLUB_DEBUG
4223 static ssize_t slabs_show(struct kmem_cache *s, char *buf)
4225 return show_slab_objects(s, buf, SO_ALL);
4227 SLAB_ATTR_RO(slabs);
4229 static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
4231 return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
4233 SLAB_ATTR_RO(total_objects);
4235 static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
4237 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
4240 static ssize_t sanity_checks_store(struct kmem_cache *s,
4241 const char *buf, size_t length)
4243 s->flags &= ~SLAB_DEBUG_FREE;
4244 if (buf[0] == '1')
4245 s->flags |= SLAB_DEBUG_FREE;
4246 return length;
4248 SLAB_ATTR(sanity_checks);
4250 static ssize_t trace_show(struct kmem_cache *s, char *buf)
4252 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
4255 static ssize_t trace_store(struct kmem_cache *s, const char *buf,
4256 size_t length)
4258 s->flags &= ~SLAB_TRACE;
4259 if (buf[0] == '1')
4260 s->flags |= SLAB_TRACE;
4261 return length;
4263 SLAB_ATTR(trace);
4265 static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
4267 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
4270 static ssize_t red_zone_store(struct kmem_cache *s,
4271 const char *buf, size_t length)
4273 if (any_slab_objects(s))
4274 return -EBUSY;
4276 s->flags &= ~SLAB_RED_ZONE;
4277 if (buf[0] == '1')
4278 s->flags |= SLAB_RED_ZONE;
4279 calculate_sizes(s, -1);
4280 return length;
4282 SLAB_ATTR(red_zone);
4284 static ssize_t poison_show(struct kmem_cache *s, char *buf)
4286 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
4289 static ssize_t poison_store(struct kmem_cache *s,
4290 const char *buf, size_t length)
4292 if (any_slab_objects(s))
4293 return -EBUSY;
4295 s->flags &= ~SLAB_POISON;
4296 if (buf[0] == '1')
4297 s->flags |= SLAB_POISON;
4298 calculate_sizes(s, -1);
4299 return length;
4301 SLAB_ATTR(poison);
4303 static ssize_t store_user_show(struct kmem_cache *s, char *buf)
4305 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
4308 static ssize_t store_user_store(struct kmem_cache *s,
4309 const char *buf, size_t length)
4311 if (any_slab_objects(s))
4312 return -EBUSY;
4314 s->flags &= ~SLAB_STORE_USER;
4315 if (buf[0] == '1')
4316 s->flags |= SLAB_STORE_USER;
4317 calculate_sizes(s, -1);
4318 return length;
4320 SLAB_ATTR(store_user);
4322 static ssize_t validate_show(struct kmem_cache *s, char *buf)
4324 return 0;
4327 static ssize_t validate_store(struct kmem_cache *s,
4328 const char *buf, size_t length)
4330 int ret = -EINVAL;
4332 if (buf[0] == '1') {
4333 ret = validate_slab_cache(s);
4334 if (ret >= 0)
4335 ret = length;
4337 return ret;
4339 SLAB_ATTR(validate);
4341 static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
4343 if (!(s->flags & SLAB_STORE_USER))
4344 return -ENOSYS;
4345 return list_locations(s, buf, TRACK_ALLOC);
4347 SLAB_ATTR_RO(alloc_calls);
4349 static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
4351 if (!(s->flags & SLAB_STORE_USER))
4352 return -ENOSYS;
4353 return list_locations(s, buf, TRACK_FREE);
4355 SLAB_ATTR_RO(free_calls);
4356 #endif /* CONFIG_SLUB_DEBUG */
4358 #ifdef CONFIG_FAILSLAB
4359 static ssize_t failslab_show(struct kmem_cache *s, char *buf)
4361 return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
4364 static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
4365 size_t length)
4367 s->flags &= ~SLAB_FAILSLAB;
4368 if (buf[0] == '1')
4369 s->flags |= SLAB_FAILSLAB;
4370 return length;
4372 SLAB_ATTR(failslab);
4373 #endif
4375 static ssize_t shrink_show(struct kmem_cache *s, char *buf)
4377 return 0;
4380 static ssize_t shrink_store(struct kmem_cache *s,
4381 const char *buf, size_t length)
4383 if (buf[0] == '1') {
4384 int rc = kmem_cache_shrink(s);
4386 if (rc)
4387 return rc;
4388 } else
4389 return -EINVAL;
4390 return length;
4392 SLAB_ATTR(shrink);
4394 #ifdef CONFIG_NUMA
4395 static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
4397 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
4400 static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
4401 const char *buf, size_t length)
4403 unsigned long ratio;
4404 int err;
4406 err = strict_strtoul(buf, 10, &ratio);
4407 if (err)
4408 return err;
4410 if (ratio <= 100)
4411 s->remote_node_defrag_ratio = ratio * 10;
4413 return length;
4415 SLAB_ATTR(remote_node_defrag_ratio);
4416 #endif
4418 #ifdef CONFIG_SLUB_STATS
4419 static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
4421 unsigned long sum = 0;
4422 int cpu;
4423 int len;
4424 int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
4426 if (!data)
4427 return -ENOMEM;
4429 for_each_online_cpu(cpu) {
4430 unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
4432 data[cpu] = x;
4433 sum += x;
4436 len = sprintf(buf, "%lu", sum);
4438 #ifdef CONFIG_SMP
4439 for_each_online_cpu(cpu) {
4440 if (data[cpu] && len < PAGE_SIZE - 20)
4441 len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
4443 #endif
4444 kfree(data);
4445 return len + sprintf(buf + len, "\n");
4448 static void clear_stat(struct kmem_cache *s, enum stat_item si)
4450 int cpu;
4452 for_each_online_cpu(cpu)
4453 per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
4456 #define STAT_ATTR(si, text) \
4457 static ssize_t text##_show(struct kmem_cache *s, char *buf) \
4459 return show_stat(s, buf, si); \
4461 static ssize_t text##_store(struct kmem_cache *s, \
4462 const char *buf, size_t length) \
4464 if (buf[0] != '0') \
4465 return -EINVAL; \
4466 clear_stat(s, si); \
4467 return length; \
4469 SLAB_ATTR(text); \
4471 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
4472 STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
4473 STAT_ATTR(FREE_FASTPATH, free_fastpath);
4474 STAT_ATTR(FREE_SLOWPATH, free_slowpath);
4475 STAT_ATTR(FREE_FROZEN, free_frozen);
4476 STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
4477 STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
4478 STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
4479 STAT_ATTR(ALLOC_SLAB, alloc_slab);
4480 STAT_ATTR(ALLOC_REFILL, alloc_refill);
4481 STAT_ATTR(FREE_SLAB, free_slab);
4482 STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
4483 STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
4484 STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
4485 STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
4486 STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
4487 STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
4488 STAT_ATTR(ORDER_FALLBACK, order_fallback);
4489 #endif
4491 static struct attribute *slab_attrs[] = {
4492 &slab_size_attr.attr,
4493 &object_size_attr.attr,
4494 &objs_per_slab_attr.attr,
4495 &order_attr.attr,
4496 &min_partial_attr.attr,
4497 &objects_attr.attr,
4498 &objects_partial_attr.attr,
4499 &partial_attr.attr,
4500 &cpu_slabs_attr.attr,
4501 &ctor_attr.attr,
4502 &aliases_attr.attr,
4503 &align_attr.attr,
4504 &hwcache_align_attr.attr,
4505 &reclaim_account_attr.attr,
4506 &destroy_by_rcu_attr.attr,
4507 &shrink_attr.attr,
4508 &reserved_attr.attr,
4509 #ifdef CONFIG_SLUB_DEBUG
4510 &total_objects_attr.attr,
4511 &slabs_attr.attr,
4512 &sanity_checks_attr.attr,
4513 &trace_attr.attr,
4514 &red_zone_attr.attr,
4515 &poison_attr.attr,
4516 &store_user_attr.attr,
4517 &validate_attr.attr,
4518 &alloc_calls_attr.attr,
4519 &free_calls_attr.attr,
4520 #endif
4521 #ifdef CONFIG_ZONE_DMA
4522 &cache_dma_attr.attr,
4523 #endif
4524 #ifdef CONFIG_NUMA
4525 &remote_node_defrag_ratio_attr.attr,
4526 #endif
4527 #ifdef CONFIG_SLUB_STATS
4528 &alloc_fastpath_attr.attr,
4529 &alloc_slowpath_attr.attr,
4530 &free_fastpath_attr.attr,
4531 &free_slowpath_attr.attr,
4532 &free_frozen_attr.attr,
4533 &free_add_partial_attr.attr,
4534 &free_remove_partial_attr.attr,
4535 &alloc_from_partial_attr.attr,
4536 &alloc_slab_attr.attr,
4537 &alloc_refill_attr.attr,
4538 &free_slab_attr.attr,
4539 &cpuslab_flush_attr.attr,
4540 &deactivate_full_attr.attr,
4541 &deactivate_empty_attr.attr,
4542 &deactivate_to_head_attr.attr,
4543 &deactivate_to_tail_attr.attr,
4544 &deactivate_remote_frees_attr.attr,
4545 &order_fallback_attr.attr,
4546 #endif
4547 #ifdef CONFIG_FAILSLAB
4548 &failslab_attr.attr,
4549 #endif
4551 NULL
4554 static struct attribute_group slab_attr_group = {
4555 .attrs = slab_attrs,
4558 static ssize_t slab_attr_show(struct kobject *kobj,
4559 struct attribute *attr,
4560 char *buf)
4562 struct slab_attribute *attribute;
4563 struct kmem_cache *s;
4564 int err;
4566 attribute = to_slab_attr(attr);
4567 s = to_slab(kobj);
4569 if (!attribute->show)
4570 return -EIO;
4572 err = attribute->show(s, buf);
4574 return err;
4577 static ssize_t slab_attr_store(struct kobject *kobj,
4578 struct attribute *attr,
4579 const char *buf, size_t len)
4581 struct slab_attribute *attribute;
4582 struct kmem_cache *s;
4583 int err;
4585 attribute = to_slab_attr(attr);
4586 s = to_slab(kobj);
4588 if (!attribute->store)
4589 return -EIO;
4591 err = attribute->store(s, buf, len);
4593 return err;
4596 static void kmem_cache_release(struct kobject *kobj)
4598 struct kmem_cache *s = to_slab(kobj);
4600 kfree(s->name);
4601 kfree(s);
4604 static const struct sysfs_ops slab_sysfs_ops = {
4605 .show = slab_attr_show,
4606 .store = slab_attr_store,
4609 static struct kobj_type slab_ktype = {
4610 .sysfs_ops = &slab_sysfs_ops,
4611 .release = kmem_cache_release
4614 static int uevent_filter(struct kset *kset, struct kobject *kobj)
4616 struct kobj_type *ktype = get_ktype(kobj);
4618 if (ktype == &slab_ktype)
4619 return 1;
4620 return 0;
4623 static const struct kset_uevent_ops slab_uevent_ops = {
4624 .filter = uevent_filter,
4627 static struct kset *slab_kset;
4629 #define ID_STR_LENGTH 64
4631 /* Create a unique string id for a slab cache:
4633 * Format :[flags-]size
4635 static char *create_unique_id(struct kmem_cache *s)
4637 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
4638 char *p = name;
4640 BUG_ON(!name);
4642 *p++ = ':';
4644 * First flags affecting slabcache operations. We will only
4645 * get here for aliasable slabs so we do not need to support
4646 * too many flags. The flags here must cover all flags that
4647 * are matched during merging to guarantee that the id is
4648 * unique.
4650 if (s->flags & SLAB_CACHE_DMA)
4651 *p++ = 'd';
4652 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4653 *p++ = 'a';
4654 if (s->flags & SLAB_DEBUG_FREE)
4655 *p++ = 'F';
4656 if (!(s->flags & SLAB_NOTRACK))
4657 *p++ = 't';
4658 if (p != name + 1)
4659 *p++ = '-';
4660 p += sprintf(p, "%07d", s->size);
4661 BUG_ON(p > name + ID_STR_LENGTH - 1);
4662 return name;
4665 static int sysfs_slab_add(struct kmem_cache *s)
4667 int err;
4668 const char *name;
4669 int unmergeable;
4671 if (slab_state < SYSFS)
4672 /* Defer until later */
4673 return 0;
4675 unmergeable = slab_unmergeable(s);
4676 if (unmergeable) {
4678 * Slabcache can never be merged so we can use the name proper.
4679 * This is typically the case for debug situations. In that
4680 * case we can catch duplicate names easily.
4682 sysfs_remove_link(&slab_kset->kobj, s->name);
4683 name = s->name;
4684 } else {
4686 * Create a unique name for the slab as a target
4687 * for the symlinks.
4689 name = create_unique_id(s);
4692 s->kobj.kset = slab_kset;
4693 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4694 if (err) {
4695 kobject_put(&s->kobj);
4696 return err;
4699 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4700 if (err) {
4701 kobject_del(&s->kobj);
4702 kobject_put(&s->kobj);
4703 return err;
4705 kobject_uevent(&s->kobj, KOBJ_ADD);
4706 if (!unmergeable) {
4707 /* Setup first alias */
4708 sysfs_slab_alias(s, s->name);
4709 kfree(name);
4711 return 0;
4714 static void sysfs_slab_remove(struct kmem_cache *s)
4716 if (slab_state < SYSFS)
4718 * Sysfs has not been setup yet so no need to remove the
4719 * cache from sysfs.
4721 return;
4723 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4724 kobject_del(&s->kobj);
4725 kobject_put(&s->kobj);
4729 * Need to buffer aliases during bootup until sysfs becomes
4730 * available lest we lose that information.
4732 struct saved_alias {
4733 struct kmem_cache *s;
4734 const char *name;
4735 struct saved_alias *next;
4738 static struct saved_alias *alias_list;
4740 static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4742 struct saved_alias *al;
4744 if (slab_state == SYSFS) {
4746 * If we have a leftover link then remove it.
4748 sysfs_remove_link(&slab_kset->kobj, name);
4749 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
4752 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4753 if (!al)
4754 return -ENOMEM;
4756 al->s = s;
4757 al->name = name;
4758 al->next = alias_list;
4759 alias_list = al;
4760 return 0;
4763 static int __init slab_sysfs_init(void)
4765 struct kmem_cache *s;
4766 int err;
4768 down_write(&slub_lock);
4770 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
4771 if (!slab_kset) {
4772 up_write(&slub_lock);
4773 printk(KERN_ERR "Cannot register slab subsystem.\n");
4774 return -ENOSYS;
4777 slab_state = SYSFS;
4779 list_for_each_entry(s, &slab_caches, list) {
4780 err = sysfs_slab_add(s);
4781 if (err)
4782 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4783 " to sysfs\n", s->name);
4786 while (alias_list) {
4787 struct saved_alias *al = alias_list;
4789 alias_list = alias_list->next;
4790 err = sysfs_slab_alias(al->s, al->name);
4791 if (err)
4792 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4793 " %s to sysfs\n", s->name);
4794 kfree(al);
4797 up_write(&slub_lock);
4798 resiliency_test();
4799 return 0;
4802 __initcall(slab_sysfs_init);
4803 #endif /* CONFIG_SYSFS */
4806 * The /proc/slabinfo ABI
4808 #ifdef CONFIG_SLABINFO
4809 static void print_slabinfo_header(struct seq_file *m)
4811 seq_puts(m, "slabinfo - version: 2.1\n");
4812 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4813 "<objperslab> <pagesperslab>");
4814 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4815 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4816 seq_putc(m, '\n');
4819 static void *s_start(struct seq_file *m, loff_t *pos)
4821 loff_t n = *pos;
4823 down_read(&slub_lock);
4824 if (!n)
4825 print_slabinfo_header(m);
4827 return seq_list_start(&slab_caches, *pos);
4830 static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4832 return seq_list_next(p, &slab_caches, pos);
4835 static void s_stop(struct seq_file *m, void *p)
4837 up_read(&slub_lock);
4840 static int s_show(struct seq_file *m, void *p)
4842 unsigned long nr_partials = 0;
4843 unsigned long nr_slabs = 0;
4844 unsigned long nr_inuse = 0;
4845 unsigned long nr_objs = 0;
4846 unsigned long nr_free = 0;
4847 struct kmem_cache *s;
4848 int node;
4850 s = list_entry(p, struct kmem_cache, list);
4852 for_each_online_node(node) {
4853 struct kmem_cache_node *n = get_node(s, node);
4855 if (!n)
4856 continue;
4858 nr_partials += n->nr_partial;
4859 nr_slabs += atomic_long_read(&n->nr_slabs);
4860 nr_objs += atomic_long_read(&n->total_objects);
4861 nr_free += count_partial(n, count_free);
4864 nr_inuse = nr_objs - nr_free;
4866 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
4867 nr_objs, s->size, oo_objects(s->oo),
4868 (1 << oo_order(s->oo)));
4869 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4870 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4871 0UL);
4872 seq_putc(m, '\n');
4873 return 0;
4876 static const struct seq_operations slabinfo_op = {
4877 .start = s_start,
4878 .next = s_next,
4879 .stop = s_stop,
4880 .show = s_show,
4883 static int slabinfo_open(struct inode *inode, struct file *file)
4885 return seq_open(file, &slabinfo_op);
4888 static const struct file_operations proc_slabinfo_operations = {
4889 .open = slabinfo_open,
4890 .read = seq_read,
4891 .llseek = seq_lseek,
4892 .release = seq_release,
4895 static int __init slab_proc_init(void)
4897 proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations);
4898 return 0;
4900 module_init(slab_proc_init);
4901 #endif /* CONFIG_SLABINFO */