blob: 3f056677fa8fea56ef3a678cc8e9d8a8d27b2371 [file] [log] [blame]
Christoph Lameter81819f02007-05-06 14:49:36 -07001/*
2 * SLUB: A slab allocator that limits cache line use instead of queuing
3 * objects in per cpu and per node lists.
4 *
5 * The allocator synchronizes using per slab locks and only
6 * uses a centralized lock to manage a pool of partial slabs.
7 *
8 * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com>
9 */
10
11#include <linux/mm.h>
12#include <linux/module.h>
13#include <linux/bit_spinlock.h>
14#include <linux/interrupt.h>
15#include <linux/bitops.h>
16#include <linux/slab.h>
17#include <linux/seq_file.h>
18#include <linux/cpu.h>
19#include <linux/cpuset.h>
20#include <linux/mempolicy.h>
21#include <linux/ctype.h>
22#include <linux/kallsyms.h>
Yasunori Gotob9049e22007-10-21 16:41:37 -070023#include <linux/memory.h>
Christoph Lameter81819f02007-05-06 14:49:36 -070024
25/*
26 * Lock order:
27 * 1. slab_lock(page)
28 * 2. slab->list_lock
29 *
30 * The slab_lock protects operations on the object of a particular
31 * slab and its metadata in the page struct. If the slab lock
32 * has been taken then no allocations nor frees can be performed
33 * on the objects in the slab nor can the slab be added or removed
34 * from the partial or full lists since this would mean modifying
35 * the page_struct of the slab.
36 *
37 * The list_lock protects the partial and full list on each node and
38 * the partial slab counter. If taken then no new slabs may be added or
39 * removed from the lists nor make the number of partial slabs be modified.
40 * (Note that the total number of slabs is an atomic value that may be
41 * modified without taking the list lock).
42 *
43 * The list_lock is a centralized lock and thus we avoid taking it as
44 * much as possible. As long as SLUB does not have to handle partial
45 * slabs, operations can continue without any centralized lock. F.e.
46 * allocating a long series of objects that fill up slabs does not require
47 * the list lock.
48 *
49 * The lock order is sometimes inverted when we are trying to get a slab
50 * off a list. We take the list_lock and then look for a page on the list
51 * to use. While we do that objects in the slabs may be freed. We can
52 * only operate on the slab if we have also taken the slab_lock. So we use
53 * a slab_trylock() on the slab. If trylock was successful then no frees
54 * can occur anymore and we can use the slab for allocations etc. If the
55 * slab_trylock() does not succeed then frees are in progress in the slab and
56 * we must stay away from it for a while since we may cause a bouncing
57 * cacheline if we try to acquire the lock. So go onto the next slab.
58 * If all pages are busy then we may allocate a new slab instead of reusing
59 * a partial slab. A new slab has noone operating on it and thus there is
60 * no danger of cacheline contention.
61 *
62 * Interrupts are disabled during allocation and deallocation in order to
63 * make the slab allocator safe to use in the context of an irq. In addition
64 * interrupts are disabled to ensure that the processor does not change
65 * while handling per_cpu slabs, due to kernel preemption.
66 *
67 * SLUB assigns one slab for allocation to each processor.
68 * Allocations only occur from these slabs called cpu slabs.
69 *
Christoph Lameter672bba32007-05-09 02:32:39 -070070 * Slabs with free elements are kept on a partial list and during regular
71 * operations no list for full slabs is used. If an object in a full slab is
Christoph Lameter81819f02007-05-06 14:49:36 -070072 * freed then the slab will show up again on the partial lists.
Christoph Lameter672bba32007-05-09 02:32:39 -070073 * We track full slabs for debugging purposes though because otherwise we
74 * cannot scan all objects.
Christoph Lameter81819f02007-05-06 14:49:36 -070075 *
76 * Slabs are freed when they become empty. Teardown and setup is
77 * minimal so we rely on the page allocators per cpu caches for
78 * fast frees and allocs.
79 *
80 * Overloading of page flags that are otherwise used for LRU management.
81 *
Christoph Lameter4b6f0752007-05-16 22:10:53 -070082 * PageActive The slab is frozen and exempt from list processing.
83 * This means that the slab is dedicated to a purpose
84 * such as satisfying allocations for a specific
85 * processor. Objects may be freed in the slab while
86 * it is frozen but slab_free will then skip the usual
87 * list operations. It is up to the processor holding
88 * the slab to integrate the slab into the slab lists
89 * when the slab is no longer needed.
90 *
91 * One use of this flag is to mark slabs that are
92 * used for allocations. Then such a slab becomes a cpu
93 * slab. The cpu slab may be equipped with an additional
Christoph Lameterdfb4f092007-10-16 01:26:05 -070094 * freelist that allows lockless access to
Christoph Lameter894b8782007-05-10 03:15:16 -070095 * free objects in addition to the regular freelist
96 * that requires the slab lock.
Christoph Lameter81819f02007-05-06 14:49:36 -070097 *
98 * PageError Slab requires special handling due to debug
99 * options set. This moves slab handling out of
Christoph Lameter894b8782007-05-10 03:15:16 -0700100 * the fast path and disables lockless freelists.
Christoph Lameter81819f02007-05-06 14:49:36 -0700101 */
102
Christoph Lameter5577bd82007-05-16 22:10:56 -0700103#define FROZEN (1 << PG_active)
104
105#ifdef CONFIG_SLUB_DEBUG
106#define SLABDEBUG (1 << PG_error)
107#else
108#define SLABDEBUG 0
109#endif
110
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700111static inline int SlabFrozen(struct page *page)
112{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700113 return page->flags & FROZEN;
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700114}
115
116static inline void SetSlabFrozen(struct page *page)
117{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700118 page->flags |= FROZEN;
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700119}
120
121static inline void ClearSlabFrozen(struct page *page)
122{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700123 page->flags &= ~FROZEN;
Christoph Lameter4b6f0752007-05-16 22:10:53 -0700124}
125
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700126static inline int SlabDebug(struct page *page)
127{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700128 return page->flags & SLABDEBUG;
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700129}
130
131static inline void SetSlabDebug(struct page *page)
132{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700133 page->flags |= SLABDEBUG;
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700134}
135
136static inline void ClearSlabDebug(struct page *page)
137{
Christoph Lameter5577bd82007-05-16 22:10:56 -0700138 page->flags &= ~SLABDEBUG;
Christoph Lameter35e5d7e2007-05-09 02:32:42 -0700139}
140
Christoph Lameter81819f02007-05-06 14:49:36 -0700141/*
142 * Issues still to be resolved:
143 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700144 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
145 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700146 * - Variable sizing of the per node arrays
147 */
148
149/* Enable to test recovery from slab corruption on boot */
150#undef SLUB_RESILIENCY_TEST
151
152#if PAGE_SHIFT <= 12
153
154/*
155 * Small page size. Make sure that we do not fragment memory
156 */
157#define DEFAULT_MAX_ORDER 1
158#define DEFAULT_MIN_OBJECTS 4
159
160#else
161
162/*
163 * Large page machines are customarily able to handle larger
164 * page orders.
165 */
166#define DEFAULT_MAX_ORDER 2
167#define DEFAULT_MIN_OBJECTS 8
168
169#endif
170
171/*
Christoph Lameter2086d262007-05-06 14:49:46 -0700172 * Mininum number of partial slabs. These will be left on the partial
173 * lists even if they are empty. kmem_cache_shrink may reclaim them.
174 */
Christoph Lameter76be8952007-12-21 14:37:37 -0800175#define MIN_PARTIAL 5
Christoph Lametere95eed52007-05-06 14:49:44 -0700176
Christoph Lameter2086d262007-05-06 14:49:46 -0700177/*
178 * Maximum number of desirable partial slabs.
179 * The existence of more partial slabs makes kmem_cache_shrink
180 * sort the partial list by the number of objects in the.
181 */
182#define MAX_PARTIAL 10
183
Christoph Lameter81819f02007-05-06 14:49:36 -0700184#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
185 SLAB_POISON | SLAB_STORE_USER)
Christoph Lameter672bba32007-05-09 02:32:39 -0700186
Christoph Lameter81819f02007-05-06 14:49:36 -0700187/*
188 * Set of flags that will prevent slab merging
189 */
190#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
191 SLAB_TRACE | SLAB_DESTROY_BY_RCU)
192
193#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
194 SLAB_CACHE_DMA)
195
196#ifndef ARCH_KMALLOC_MINALIGN
Christoph Lameter47bfdc02007-05-06 14:49:37 -0700197#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
Christoph Lameter81819f02007-05-06 14:49:36 -0700198#endif
199
200#ifndef ARCH_SLAB_MINALIGN
Christoph Lameter47bfdc02007-05-06 14:49:37 -0700201#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
Christoph Lameter81819f02007-05-06 14:49:36 -0700202#endif
203
204/* Internal SLUB flags */
Christoph Lameter1ceef402007-08-07 15:11:48 -0700205#define __OBJECT_POISON 0x80000000 /* Poison object */
206#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
Christoph Lameter81819f02007-05-06 14:49:36 -0700207
Christoph Lameter65c02d42007-05-09 02:32:35 -0700208/* Not all arches define cache_line_size */
209#ifndef cache_line_size
210#define cache_line_size() L1_CACHE_BYTES
211#endif
212
Christoph Lameter81819f02007-05-06 14:49:36 -0700213static int kmem_size = sizeof(struct kmem_cache);
214
215#ifdef CONFIG_SMP
216static struct notifier_block slab_notifier;
217#endif
218
219static enum {
220 DOWN, /* No slab functionality available */
221 PARTIAL, /* kmem_cache_open() works but kmalloc does not */
Christoph Lameter672bba32007-05-09 02:32:39 -0700222 UP, /* Everything works but does not show up in sysfs */
Christoph Lameter81819f02007-05-06 14:49:36 -0700223 SYSFS /* Sysfs up */
224} slab_state = DOWN;
225
226/* A list of all slab caches on the system */
227static DECLARE_RWSEM(slub_lock);
Adrian Bunk5af328a2007-07-17 04:03:27 -0700228static LIST_HEAD(slab_caches);
Christoph Lameter81819f02007-05-06 14:49:36 -0700229
Christoph Lameter02cbc872007-05-09 02:32:43 -0700230/*
231 * Tracking user of a slab.
232 */
233struct track {
234 void *addr; /* Called from address */
235 int cpu; /* Was running on cpu */
236 int pid; /* Pid context */
237 unsigned long when; /* When did the operation occur */
238};
239
240enum track_item { TRACK_ALLOC, TRACK_FREE };
241
Christoph Lameter41ecc552007-05-09 02:32:44 -0700242#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
Christoph Lameter81819f02007-05-06 14:49:36 -0700243static int sysfs_slab_add(struct kmem_cache *);
244static int sysfs_slab_alias(struct kmem_cache *, const char *);
245static void sysfs_slab_remove(struct kmem_cache *);
246#else
Christoph Lameter0c710012007-07-17 04:03:24 -0700247static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
248static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
249 { return 0; }
Christoph Lameter151c6022008-01-07 22:29:05 -0800250static inline void sysfs_slab_remove(struct kmem_cache *s)
251{
252 kfree(s);
253}
Christoph Lameter81819f02007-05-06 14:49:36 -0700254#endif
255
256/********************************************************************
257 * Core slab cache functions
258 *******************************************************************/
259
260int slab_is_available(void)
261{
262 return slab_state >= UP;
263}
264
265static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
266{
267#ifdef CONFIG_NUMA
268 return s->node[node];
269#else
270 return &s->local_node;
271#endif
272}
273
Christoph Lameterdfb4f092007-10-16 01:26:05 -0700274static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu)
275{
Christoph Lameter4c93c3552007-10-16 01:26:08 -0700276#ifdef CONFIG_SMP
277 return s->cpu_slab[cpu];
278#else
279 return &s->cpu_slab;
280#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -0700281}
282
Christoph Lameter02cbc872007-05-09 02:32:43 -0700283static inline int check_valid_pointer(struct kmem_cache *s,
284 struct page *page, const void *object)
285{
286 void *base;
287
288 if (!object)
289 return 1;
290
291 base = page_address(page);
292 if (object < base || object >= base + s->objects * s->size ||
293 (object - base) % s->size) {
294 return 0;
295 }
296
297 return 1;
298}
299
Christoph Lameter81819f02007-05-06 14:49:36 -0700300/*
Christoph Lameter7656c722007-05-09 02:32:40 -0700301 * Slow version of get and set free pointer.
302 *
303 * This version requires touching the cache lines of kmem_cache which
304 * we avoid to do in the fast alloc free paths. There we obtain the offset
305 * from the page struct.
306 */
307static inline void *get_freepointer(struct kmem_cache *s, void *object)
308{
309 return *(void **)(object + s->offset);
310}
311
312static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
313{
314 *(void **)(object + s->offset) = fp;
315}
316
317/* Loop over all objects in a slab */
318#define for_each_object(__p, __s, __addr) \
319 for (__p = (__addr); __p < (__addr) + (__s)->objects * (__s)->size;\
320 __p += (__s)->size)
321
322/* Scan freelist */
323#define for_each_free_object(__p, __s, __free) \
324 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
325
326/* Determine object index from a given position */
327static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
328{
329 return (p - addr) / s->size;
330}
331
Christoph Lameter41ecc552007-05-09 02:32:44 -0700332#ifdef CONFIG_SLUB_DEBUG
333/*
334 * Debug settings:
335 */
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700336#ifdef CONFIG_SLUB_DEBUG_ON
337static int slub_debug = DEBUG_DEFAULT_FLAGS;
338#else
Christoph Lameter41ecc552007-05-09 02:32:44 -0700339static int slub_debug;
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700340#endif
Christoph Lameter41ecc552007-05-09 02:32:44 -0700341
342static char *slub_debug_slabs;
343
Christoph Lameter7656c722007-05-09 02:32:40 -0700344/*
Christoph Lameter81819f02007-05-06 14:49:36 -0700345 * Object debugging
346 */
347static void print_section(char *text, u8 *addr, unsigned int length)
348{
349 int i, offset;
350 int newline = 1;
351 char ascii[17];
352
353 ascii[16] = 0;
354
355 for (i = 0; i < length; i++) {
356 if (newline) {
Christoph Lameter24922682007-07-17 04:03:18 -0700357 printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
Christoph Lameter81819f02007-05-06 14:49:36 -0700358 newline = 0;
359 }
Pekka Enberg06428782008-01-07 23:20:27 -0800360 printk(KERN_CONT " %02x", addr[i]);
Christoph Lameter81819f02007-05-06 14:49:36 -0700361 offset = i % 16;
362 ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
363 if (offset == 15) {
Pekka Enberg06428782008-01-07 23:20:27 -0800364 printk(KERN_CONT " %s\n", ascii);
Christoph Lameter81819f02007-05-06 14:49:36 -0700365 newline = 1;
366 }
367 }
368 if (!newline) {
369 i %= 16;
370 while (i < 16) {
Pekka Enberg06428782008-01-07 23:20:27 -0800371 printk(KERN_CONT " ");
Christoph Lameter81819f02007-05-06 14:49:36 -0700372 ascii[i] = ' ';
373 i++;
374 }
Pekka Enberg06428782008-01-07 23:20:27 -0800375 printk(KERN_CONT " %s\n", ascii);
Christoph Lameter81819f02007-05-06 14:49:36 -0700376 }
377}
378
Christoph Lameter81819f02007-05-06 14:49:36 -0700379static struct track *get_track(struct kmem_cache *s, void *object,
380 enum track_item alloc)
381{
382 struct track *p;
383
384 if (s->offset)
385 p = object + s->offset + sizeof(void *);
386 else
387 p = object + s->inuse;
388
389 return p + alloc;
390}
391
392static void set_track(struct kmem_cache *s, void *object,
393 enum track_item alloc, void *addr)
394{
395 struct track *p;
396
397 if (s->offset)
398 p = object + s->offset + sizeof(void *);
399 else
400 p = object + s->inuse;
401
402 p += alloc;
403 if (addr) {
404 p->addr = addr;
405 p->cpu = smp_processor_id();
406 p->pid = current ? current->pid : -1;
407 p->when = jiffies;
408 } else
409 memset(p, 0, sizeof(struct track));
410}
411
Christoph Lameter81819f02007-05-06 14:49:36 -0700412static void init_tracking(struct kmem_cache *s, void *object)
413{
Christoph Lameter24922682007-07-17 04:03:18 -0700414 if (!(s->flags & SLAB_STORE_USER))
415 return;
416
417 set_track(s, object, TRACK_FREE, NULL);
418 set_track(s, object, TRACK_ALLOC, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -0700419}
420
421static void print_track(const char *s, struct track *t)
422{
423 if (!t->addr)
424 return;
425
Christoph Lameter24922682007-07-17 04:03:18 -0700426 printk(KERN_ERR "INFO: %s in ", s);
Christoph Lameter81819f02007-05-06 14:49:36 -0700427 __print_symbol("%s", (unsigned long)t->addr);
Christoph Lameter24922682007-07-17 04:03:18 -0700428 printk(" age=%lu cpu=%u pid=%d\n", jiffies - t->when, t->cpu, t->pid);
Christoph Lameter81819f02007-05-06 14:49:36 -0700429}
430
Christoph Lameter24922682007-07-17 04:03:18 -0700431static void print_tracking(struct kmem_cache *s, void *object)
432{
433 if (!(s->flags & SLAB_STORE_USER))
434 return;
435
436 print_track("Allocated", get_track(s, object, TRACK_ALLOC));
437 print_track("Freed", get_track(s, object, TRACK_FREE));
438}
439
440static void print_page_info(struct page *page)
441{
442 printk(KERN_ERR "INFO: Slab 0x%p used=%u fp=0x%p flags=0x%04lx\n",
443 page, page->inuse, page->freelist, page->flags);
444
445}
446
447static void slab_bug(struct kmem_cache *s, char *fmt, ...)
448{
449 va_list args;
450 char buf[100];
451
452 va_start(args, fmt);
453 vsnprintf(buf, sizeof(buf), fmt, args);
454 va_end(args);
455 printk(KERN_ERR "========================================"
456 "=====================================\n");
457 printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
458 printk(KERN_ERR "----------------------------------------"
459 "-------------------------------------\n\n");
460}
461
462static void slab_fix(struct kmem_cache *s, char *fmt, ...)
463{
464 va_list args;
465 char buf[100];
466
467 va_start(args, fmt);
468 vsnprintf(buf, sizeof(buf), fmt, args);
469 va_end(args);
470 printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
471}
472
473static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
Christoph Lameter81819f02007-05-06 14:49:36 -0700474{
475 unsigned int off; /* Offset of last byte */
Christoph Lameter24922682007-07-17 04:03:18 -0700476 u8 *addr = page_address(page);
477
478 print_tracking(s, p);
479
480 print_page_info(page);
481
482 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
483 p, p - addr, get_freepointer(s, p));
484
485 if (p > addr + 16)
486 print_section("Bytes b4", p - 16, 16);
487
488 print_section("Object", p, min(s->objsize, 128));
Christoph Lameter81819f02007-05-06 14:49:36 -0700489
490 if (s->flags & SLAB_RED_ZONE)
491 print_section("Redzone", p + s->objsize,
492 s->inuse - s->objsize);
493
Christoph Lameter81819f02007-05-06 14:49:36 -0700494 if (s->offset)
495 off = s->offset + sizeof(void *);
496 else
497 off = s->inuse;
498
Christoph Lameter24922682007-07-17 04:03:18 -0700499 if (s->flags & SLAB_STORE_USER)
Christoph Lameter81819f02007-05-06 14:49:36 -0700500 off += 2 * sizeof(struct track);
Christoph Lameter81819f02007-05-06 14:49:36 -0700501
502 if (off != s->size)
503 /* Beginning of the filler is the free pointer */
Christoph Lameter24922682007-07-17 04:03:18 -0700504 print_section("Padding", p + off, s->size - off);
505
506 dump_stack();
Christoph Lameter81819f02007-05-06 14:49:36 -0700507}
508
509static void object_err(struct kmem_cache *s, struct page *page,
510 u8 *object, char *reason)
511{
Christoph Lameter24922682007-07-17 04:03:18 -0700512 slab_bug(s, reason);
513 print_trailer(s, page, object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700514}
515
Christoph Lameter24922682007-07-17 04:03:18 -0700516static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
Christoph Lameter81819f02007-05-06 14:49:36 -0700517{
518 va_list args;
519 char buf[100];
520
Christoph Lameter24922682007-07-17 04:03:18 -0700521 va_start(args, fmt);
522 vsnprintf(buf, sizeof(buf), fmt, args);
Christoph Lameter81819f02007-05-06 14:49:36 -0700523 va_end(args);
Christoph Lameter24922682007-07-17 04:03:18 -0700524 slab_bug(s, fmt);
525 print_page_info(page);
Christoph Lameter81819f02007-05-06 14:49:36 -0700526 dump_stack();
527}
528
529static void init_object(struct kmem_cache *s, void *object, int active)
530{
531 u8 *p = object;
532
533 if (s->flags & __OBJECT_POISON) {
534 memset(p, POISON_FREE, s->objsize - 1);
Pekka Enberg06428782008-01-07 23:20:27 -0800535 p[s->objsize - 1] = POISON_END;
Christoph Lameter81819f02007-05-06 14:49:36 -0700536 }
537
538 if (s->flags & SLAB_RED_ZONE)
539 memset(p + s->objsize,
540 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE,
541 s->inuse - s->objsize);
542}
543
Christoph Lameter24922682007-07-17 04:03:18 -0700544static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes)
Christoph Lameter81819f02007-05-06 14:49:36 -0700545{
546 while (bytes) {
547 if (*start != (u8)value)
Christoph Lameter24922682007-07-17 04:03:18 -0700548 return start;
Christoph Lameter81819f02007-05-06 14:49:36 -0700549 start++;
550 bytes--;
551 }
Christoph Lameter24922682007-07-17 04:03:18 -0700552 return NULL;
553}
554
555static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
556 void *from, void *to)
557{
558 slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
559 memset(from, data, to - from);
560}
561
562static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
563 u8 *object, char *what,
Pekka Enberg06428782008-01-07 23:20:27 -0800564 u8 *start, unsigned int value, unsigned int bytes)
Christoph Lameter24922682007-07-17 04:03:18 -0700565{
566 u8 *fault;
567 u8 *end;
568
569 fault = check_bytes(start, value, bytes);
570 if (!fault)
571 return 1;
572
573 end = start + bytes;
574 while (end > fault && end[-1] == value)
575 end--;
576
577 slab_bug(s, "%s overwritten", what);
578 printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
579 fault, end - 1, fault[0], value);
580 print_trailer(s, page, object);
581
582 restore_bytes(s, what, value, fault, end);
583 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700584}
585
Christoph Lameter81819f02007-05-06 14:49:36 -0700586/*
587 * Object layout:
588 *
589 * object address
590 * Bytes of the object to be managed.
591 * If the freepointer may overlay the object then the free
592 * pointer is the first word of the object.
Christoph Lameter672bba32007-05-09 02:32:39 -0700593 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700594 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
595 * 0xa5 (POISON_END)
596 *
597 * object + s->objsize
598 * Padding to reach word boundary. This is also used for Redzoning.
Christoph Lameter672bba32007-05-09 02:32:39 -0700599 * Padding is extended by another word if Redzoning is enabled and
600 * objsize == inuse.
601 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700602 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
603 * 0xcc (RED_ACTIVE) for objects in use.
604 *
605 * object + s->inuse
Christoph Lameter672bba32007-05-09 02:32:39 -0700606 * Meta data starts here.
607 *
Christoph Lameter81819f02007-05-06 14:49:36 -0700608 * A. Free pointer (if we cannot overwrite object on free)
609 * B. Tracking data for SLAB_STORE_USER
Christoph Lameter672bba32007-05-09 02:32:39 -0700610 * C. Padding to reach required alignment boundary or at mininum
611 * one word if debuggin is on to be able to detect writes
612 * before the word boundary.
613 *
614 * Padding is done using 0x5a (POISON_INUSE)
Christoph Lameter81819f02007-05-06 14:49:36 -0700615 *
616 * object + s->size
Christoph Lameter672bba32007-05-09 02:32:39 -0700617 * Nothing is used beyond s->size.
Christoph Lameter81819f02007-05-06 14:49:36 -0700618 *
Christoph Lameter672bba32007-05-09 02:32:39 -0700619 * If slabcaches are merged then the objsize and inuse boundaries are mostly
620 * ignored. And therefore no slab options that rely on these boundaries
Christoph Lameter81819f02007-05-06 14:49:36 -0700621 * may be used with merged slabcaches.
622 */
623
Christoph Lameter81819f02007-05-06 14:49:36 -0700624static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
625{
626 unsigned long off = s->inuse; /* The end of info */
627
628 if (s->offset)
629 /* Freepointer is placed after the object. */
630 off += sizeof(void *);
631
632 if (s->flags & SLAB_STORE_USER)
633 /* We also have user information there */
634 off += 2 * sizeof(struct track);
635
636 if (s->size == off)
637 return 1;
638
Christoph Lameter24922682007-07-17 04:03:18 -0700639 return check_bytes_and_report(s, page, p, "Object padding",
640 p + off, POISON_INUSE, s->size - off);
Christoph Lameter81819f02007-05-06 14:49:36 -0700641}
642
643static int slab_pad_check(struct kmem_cache *s, struct page *page)
644{
Christoph Lameter24922682007-07-17 04:03:18 -0700645 u8 *start;
646 u8 *fault;
647 u8 *end;
648 int length;
649 int remainder;
Christoph Lameter81819f02007-05-06 14:49:36 -0700650
651 if (!(s->flags & SLAB_POISON))
652 return 1;
653
Christoph Lameter24922682007-07-17 04:03:18 -0700654 start = page_address(page);
655 end = start + (PAGE_SIZE << s->order);
Christoph Lameter81819f02007-05-06 14:49:36 -0700656 length = s->objects * s->size;
Christoph Lameter24922682007-07-17 04:03:18 -0700657 remainder = end - (start + length);
Christoph Lameter81819f02007-05-06 14:49:36 -0700658 if (!remainder)
659 return 1;
660
Christoph Lameter24922682007-07-17 04:03:18 -0700661 fault = check_bytes(start + length, POISON_INUSE, remainder);
662 if (!fault)
663 return 1;
664 while (end > fault && end[-1] == POISON_INUSE)
665 end--;
666
667 slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
668 print_section("Padding", start, length);
669
670 restore_bytes(s, "slab padding", POISON_INUSE, start, end);
671 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700672}
673
674static int check_object(struct kmem_cache *s, struct page *page,
675 void *object, int active)
676{
677 u8 *p = object;
678 u8 *endobject = object + s->objsize;
679
680 if (s->flags & SLAB_RED_ZONE) {
681 unsigned int red =
682 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE;
683
Christoph Lameter24922682007-07-17 04:03:18 -0700684 if (!check_bytes_and_report(s, page, object, "Redzone",
685 endobject, red, s->inuse - s->objsize))
Christoph Lameter81819f02007-05-06 14:49:36 -0700686 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700687 } else {
Christoph Lameter24922682007-07-17 04:03:18 -0700688 if ((s->flags & SLAB_POISON) && s->objsize < s->inuse)
689 check_bytes_and_report(s, page, p, "Alignment padding", endobject,
690 POISON_INUSE, s->inuse - s->objsize);
Christoph Lameter81819f02007-05-06 14:49:36 -0700691 }
692
693 if (s->flags & SLAB_POISON) {
694 if (!active && (s->flags & __OBJECT_POISON) &&
Christoph Lameter24922682007-07-17 04:03:18 -0700695 (!check_bytes_and_report(s, page, p, "Poison", p,
696 POISON_FREE, s->objsize - 1) ||
697 !check_bytes_and_report(s, page, p, "Poison",
Pekka Enberg06428782008-01-07 23:20:27 -0800698 p + s->objsize - 1, POISON_END, 1)))
Christoph Lameter81819f02007-05-06 14:49:36 -0700699 return 0;
Christoph Lameter81819f02007-05-06 14:49:36 -0700700 /*
701 * check_pad_bytes cleans up on its own.
702 */
703 check_pad_bytes(s, page, p);
704 }
705
706 if (!s->offset && active)
707 /*
708 * Object and freepointer overlap. Cannot check
709 * freepointer while object is allocated.
710 */
711 return 1;
712
713 /* Check free pointer validity */
714 if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
715 object_err(s, page, p, "Freepointer corrupt");
716 /*
717 * No choice but to zap it and thus loose the remainder
718 * of the free objects in this slab. May cause
Christoph Lameter672bba32007-05-09 02:32:39 -0700719 * another error because the object count is now wrong.
Christoph Lameter81819f02007-05-06 14:49:36 -0700720 */
721 set_freepointer(s, p, NULL);
722 return 0;
723 }
724 return 1;
725}
726
727static int check_slab(struct kmem_cache *s, struct page *page)
728{
729 VM_BUG_ON(!irqs_disabled());
730
731 if (!PageSlab(page)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700732 slab_err(s, page, "Not a valid slab page");
Christoph Lameter81819f02007-05-06 14:49:36 -0700733 return 0;
734 }
Christoph Lameter81819f02007-05-06 14:49:36 -0700735 if (page->inuse > s->objects) {
Christoph Lameter24922682007-07-17 04:03:18 -0700736 slab_err(s, page, "inuse %u > max %u",
737 s->name, page->inuse, s->objects);
Christoph Lameter81819f02007-05-06 14:49:36 -0700738 return 0;
739 }
740 /* Slab_pad_check fixes things up after itself */
741 slab_pad_check(s, page);
742 return 1;
743}
744
745/*
Christoph Lameter672bba32007-05-09 02:32:39 -0700746 * Determine if a certain object on a page is on the freelist. Must hold the
747 * slab lock to guarantee that the chains are in a consistent state.
Christoph Lameter81819f02007-05-06 14:49:36 -0700748 */
749static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
750{
751 int nr = 0;
752 void *fp = page->freelist;
753 void *object = NULL;
754
755 while (fp && nr <= s->objects) {
756 if (fp == search)
757 return 1;
758 if (!check_valid_pointer(s, page, fp)) {
759 if (object) {
760 object_err(s, page, object,
761 "Freechain corrupt");
762 set_freepointer(s, object, NULL);
763 break;
764 } else {
Christoph Lameter24922682007-07-17 04:03:18 -0700765 slab_err(s, page, "Freepointer corrupt");
Christoph Lameter81819f02007-05-06 14:49:36 -0700766 page->freelist = NULL;
767 page->inuse = s->objects;
Christoph Lameter24922682007-07-17 04:03:18 -0700768 slab_fix(s, "Freelist cleared");
Christoph Lameter81819f02007-05-06 14:49:36 -0700769 return 0;
770 }
771 break;
772 }
773 object = fp;
774 fp = get_freepointer(s, object);
775 nr++;
776 }
777
778 if (page->inuse != s->objects - nr) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700779 slab_err(s, page, "Wrong object count. Counter is %d but "
Christoph Lameter24922682007-07-17 04:03:18 -0700780 "counted were %d", page->inuse, s->objects - nr);
Christoph Lameter81819f02007-05-06 14:49:36 -0700781 page->inuse = s->objects - nr;
Christoph Lameter24922682007-07-17 04:03:18 -0700782 slab_fix(s, "Object count adjusted.");
Christoph Lameter81819f02007-05-06 14:49:36 -0700783 }
784 return search == NULL;
785}
786
Christoph Lameter3ec09742007-05-16 22:11:00 -0700787static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc)
788{
789 if (s->flags & SLAB_TRACE) {
790 printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
791 s->name,
792 alloc ? "alloc" : "free",
793 object, page->inuse,
794 page->freelist);
795
796 if (!alloc)
797 print_section("Object", (void *)object, s->objsize);
798
799 dump_stack();
800 }
801}
802
Christoph Lameter643b1132007-05-06 14:49:42 -0700803/*
Christoph Lameter672bba32007-05-09 02:32:39 -0700804 * Tracking of fully allocated slabs for debugging purposes.
Christoph Lameter643b1132007-05-06 14:49:42 -0700805 */
Christoph Lametere95eed52007-05-06 14:49:44 -0700806static void add_full(struct kmem_cache_node *n, struct page *page)
Christoph Lameter643b1132007-05-06 14:49:42 -0700807{
Christoph Lameter643b1132007-05-06 14:49:42 -0700808 spin_lock(&n->list_lock);
809 list_add(&page->lru, &n->full);
810 spin_unlock(&n->list_lock);
811}
812
813static void remove_full(struct kmem_cache *s, struct page *page)
814{
815 struct kmem_cache_node *n;
816
817 if (!(s->flags & SLAB_STORE_USER))
818 return;
819
820 n = get_node(s, page_to_nid(page));
821
822 spin_lock(&n->list_lock);
823 list_del(&page->lru);
824 spin_unlock(&n->list_lock);
825}
826
Christoph Lameter3ec09742007-05-16 22:11:00 -0700827static void setup_object_debug(struct kmem_cache *s, struct page *page,
828 void *object)
829{
830 if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
831 return;
832
833 init_object(s, object, 0);
834 init_tracking(s, object);
835}
836
837static int alloc_debug_processing(struct kmem_cache *s, struct page *page,
838 void *object, void *addr)
Christoph Lameter81819f02007-05-06 14:49:36 -0700839{
840 if (!check_slab(s, page))
841 goto bad;
842
843 if (object && !on_freelist(s, page, object)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700844 object_err(s, page, object, "Object already allocated");
Christoph Lameter70d71222007-05-06 14:49:47 -0700845 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700846 }
847
848 if (!check_valid_pointer(s, page, object)) {
849 object_err(s, page, object, "Freelist Pointer check fails");
Christoph Lameter70d71222007-05-06 14:49:47 -0700850 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700851 }
852
Christoph Lameter3ec09742007-05-16 22:11:00 -0700853 if (object && !check_object(s, page, object, 0))
Christoph Lameter81819f02007-05-06 14:49:36 -0700854 goto bad;
Christoph Lameter81819f02007-05-06 14:49:36 -0700855
Christoph Lameter3ec09742007-05-16 22:11:00 -0700856 /* Success perform special debug activities for allocs */
857 if (s->flags & SLAB_STORE_USER)
858 set_track(s, object, TRACK_ALLOC, addr);
859 trace(s, page, object, 1);
860 init_object(s, object, 1);
Christoph Lameter81819f02007-05-06 14:49:36 -0700861 return 1;
Christoph Lameter3ec09742007-05-16 22:11:00 -0700862
Christoph Lameter81819f02007-05-06 14:49:36 -0700863bad:
864 if (PageSlab(page)) {
865 /*
866 * If this is a slab page then lets do the best we can
867 * to avoid issues in the future. Marking all objects
Christoph Lameter672bba32007-05-09 02:32:39 -0700868 * as used avoids touching the remaining objects.
Christoph Lameter81819f02007-05-06 14:49:36 -0700869 */
Christoph Lameter24922682007-07-17 04:03:18 -0700870 slab_fix(s, "Marking all objects used");
Christoph Lameter81819f02007-05-06 14:49:36 -0700871 page->inuse = s->objects;
872 page->freelist = NULL;
Christoph Lameter81819f02007-05-06 14:49:36 -0700873 }
874 return 0;
875}
876
Christoph Lameter3ec09742007-05-16 22:11:00 -0700877static int free_debug_processing(struct kmem_cache *s, struct page *page,
878 void *object, void *addr)
Christoph Lameter81819f02007-05-06 14:49:36 -0700879{
880 if (!check_slab(s, page))
881 goto fail;
882
883 if (!check_valid_pointer(s, page, object)) {
Christoph Lameter70d71222007-05-06 14:49:47 -0700884 slab_err(s, page, "Invalid object pointer 0x%p", object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700885 goto fail;
886 }
887
888 if (on_freelist(s, page, object)) {
Christoph Lameter24922682007-07-17 04:03:18 -0700889 object_err(s, page, object, "Object already free");
Christoph Lameter81819f02007-05-06 14:49:36 -0700890 goto fail;
891 }
892
893 if (!check_object(s, page, object, 1))
894 return 0;
895
896 if (unlikely(s != page->slab)) {
897 if (!PageSlab(page))
Christoph Lameter70d71222007-05-06 14:49:47 -0700898 slab_err(s, page, "Attempt to free object(0x%p) "
899 "outside of slab", object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700900 else
Christoph Lameter70d71222007-05-06 14:49:47 -0700901 if (!page->slab) {
Christoph Lameter81819f02007-05-06 14:49:36 -0700902 printk(KERN_ERR
Christoph Lameter70d71222007-05-06 14:49:47 -0700903 "SLUB <none>: no slab for object 0x%p.\n",
Christoph Lameter81819f02007-05-06 14:49:36 -0700904 object);
Christoph Lameter70d71222007-05-06 14:49:47 -0700905 dump_stack();
Pekka Enberg06428782008-01-07 23:20:27 -0800906 } else
Christoph Lameter24922682007-07-17 04:03:18 -0700907 object_err(s, page, object,
908 "page slab pointer corrupt.");
Christoph Lameter81819f02007-05-06 14:49:36 -0700909 goto fail;
910 }
Christoph Lameter3ec09742007-05-16 22:11:00 -0700911
912 /* Special debug activities for freeing objects */
913 if (!SlabFrozen(page) && !page->freelist)
914 remove_full(s, page);
915 if (s->flags & SLAB_STORE_USER)
916 set_track(s, object, TRACK_FREE, addr);
917 trace(s, page, object, 0);
918 init_object(s, object, 0);
Christoph Lameter81819f02007-05-06 14:49:36 -0700919 return 1;
Christoph Lameter3ec09742007-05-16 22:11:00 -0700920
Christoph Lameter81819f02007-05-06 14:49:36 -0700921fail:
Christoph Lameter24922682007-07-17 04:03:18 -0700922 slab_fix(s, "Object at 0x%p not freed", object);
Christoph Lameter81819f02007-05-06 14:49:36 -0700923 return 0;
924}
925
Christoph Lameter41ecc552007-05-09 02:32:44 -0700926static int __init setup_slub_debug(char *str)
927{
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700928 slub_debug = DEBUG_DEFAULT_FLAGS;
929 if (*str++ != '=' || !*str)
930 /*
931 * No options specified. Switch on full debugging.
932 */
933 goto out;
Christoph Lameter41ecc552007-05-09 02:32:44 -0700934
935 if (*str == ',')
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700936 /*
937 * No options but restriction on slabs. This means full
938 * debugging for slabs matching a pattern.
939 */
940 goto check_slabs;
941
942 slub_debug = 0;
943 if (*str == '-')
944 /*
945 * Switch off all debugging measures.
946 */
947 goto out;
948
949 /*
950 * Determine which debug features should be switched on
951 */
Pekka Enberg06428782008-01-07 23:20:27 -0800952 for (; *str && *str != ','; str++) {
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700953 switch (tolower(*str)) {
954 case 'f':
955 slub_debug |= SLAB_DEBUG_FREE;
956 break;
957 case 'z':
958 slub_debug |= SLAB_RED_ZONE;
959 break;
960 case 'p':
961 slub_debug |= SLAB_POISON;
962 break;
963 case 'u':
964 slub_debug |= SLAB_STORE_USER;
965 break;
966 case 't':
967 slub_debug |= SLAB_TRACE;
968 break;
969 default:
970 printk(KERN_ERR "slub_debug option '%c' "
Pekka Enberg06428782008-01-07 23:20:27 -0800971 "unknown. skipped\n", *str);
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700972 }
973 }
974
975check_slabs:
976 if (*str == ',')
Christoph Lameter41ecc552007-05-09 02:32:44 -0700977 slub_debug_slabs = str + 1;
Christoph Lameterf0630ff2007-07-15 23:38:14 -0700978out:
Christoph Lameter41ecc552007-05-09 02:32:44 -0700979 return 1;
980}
981
982__setup("slub_debug", setup_slub_debug);
983
Christoph Lameterba0268a2007-09-11 15:24:11 -0700984static unsigned long kmem_cache_flags(unsigned long objsize,
985 unsigned long flags, const char *name,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -0700986 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter41ecc552007-05-09 02:32:44 -0700987{
988 /*
989 * The page->offset field is only 16 bit wide. This is an offset
990 * in units of words from the beginning of an object. If the slab
991 * size is bigger then we cannot move the free pointer behind the
992 * object anymore.
993 *
994 * On 32 bit platforms the limit is 256k. On 64bit platforms
995 * the limit is 512k.
996 *
Christoph Lameterc59def9f2007-05-16 22:10:50 -0700997 * Debugging or ctor may create a need to move the free
Christoph Lameter41ecc552007-05-09 02:32:44 -0700998 * pointer. Fail if this happens.
999 */
Christoph Lameterba0268a2007-09-11 15:24:11 -07001000 if (objsize >= 65535 * sizeof(void *)) {
1001 BUG_ON(flags & (SLAB_RED_ZONE | SLAB_POISON |
Christoph Lameter41ecc552007-05-09 02:32:44 -07001002 SLAB_STORE_USER | SLAB_DESTROY_BY_RCU));
Christoph Lameterba0268a2007-09-11 15:24:11 -07001003 BUG_ON(ctor);
1004 } else {
Christoph Lameter41ecc552007-05-09 02:32:44 -07001005 /*
1006 * Enable debugging if selected on the kernel commandline.
1007 */
1008 if (slub_debug && (!slub_debug_slabs ||
Christoph Lameterba0268a2007-09-11 15:24:11 -07001009 strncmp(slub_debug_slabs, name,
Christoph Lameter41ecc552007-05-09 02:32:44 -07001010 strlen(slub_debug_slabs)) == 0))
Christoph Lameterba0268a2007-09-11 15:24:11 -07001011 flags |= slub_debug;
1012 }
1013
1014 return flags;
Christoph Lameter41ecc552007-05-09 02:32:44 -07001015}
1016#else
Christoph Lameter3ec09742007-05-16 22:11:00 -07001017static inline void setup_object_debug(struct kmem_cache *s,
1018 struct page *page, void *object) {}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001019
Christoph Lameter3ec09742007-05-16 22:11:00 -07001020static inline int alloc_debug_processing(struct kmem_cache *s,
1021 struct page *page, void *object, void *addr) { return 0; }
Christoph Lameter41ecc552007-05-09 02:32:44 -07001022
Christoph Lameter3ec09742007-05-16 22:11:00 -07001023static inline int free_debug_processing(struct kmem_cache *s,
1024 struct page *page, void *object, void *addr) { return 0; }
Christoph Lameter41ecc552007-05-09 02:32:44 -07001025
Christoph Lameter41ecc552007-05-09 02:32:44 -07001026static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
1027 { return 1; }
1028static inline int check_object(struct kmem_cache *s, struct page *page,
1029 void *object, int active) { return 1; }
Christoph Lameter3ec09742007-05-16 22:11:00 -07001030static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
Christoph Lameterba0268a2007-09-11 15:24:11 -07001031static inline unsigned long kmem_cache_flags(unsigned long objsize,
1032 unsigned long flags, const char *name,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07001033 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameterba0268a2007-09-11 15:24:11 -07001034{
1035 return flags;
1036}
Christoph Lameter41ecc552007-05-09 02:32:44 -07001037#define slub_debug 0
1038#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07001039/*
1040 * Slab allocation and freeing
1041 */
1042static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1043{
Pekka Enberg06428782008-01-07 23:20:27 -08001044 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07001045 int pages = 1 << s->order;
1046
1047 if (s->order)
1048 flags |= __GFP_COMP;
1049
1050 if (s->flags & SLAB_CACHE_DMA)
1051 flags |= SLUB_DMA;
1052
Mel Gormane12ba742007-10-16 01:25:52 -07001053 if (s->flags & SLAB_RECLAIM_ACCOUNT)
1054 flags |= __GFP_RECLAIMABLE;
1055
Christoph Lameter81819f02007-05-06 14:49:36 -07001056 if (node == -1)
1057 page = alloc_pages(flags, s->order);
1058 else
1059 page = alloc_pages_node(node, flags, s->order);
1060
1061 if (!page)
1062 return NULL;
1063
1064 mod_zone_page_state(page_zone(page),
1065 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1066 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1067 pages);
1068
1069 return page;
1070}
1071
1072static void setup_object(struct kmem_cache *s, struct page *page,
1073 void *object)
1074{
Christoph Lameter3ec09742007-05-16 22:11:00 -07001075 setup_object_debug(s, page, object);
Christoph Lameter4f104932007-05-06 14:50:17 -07001076 if (unlikely(s->ctor))
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07001077 s->ctor(s, object);
Christoph Lameter81819f02007-05-06 14:49:36 -07001078}
1079
1080static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1081{
1082 struct page *page;
1083 struct kmem_cache_node *n;
1084 void *start;
Christoph Lameter81819f02007-05-06 14:49:36 -07001085 void *last;
1086 void *p;
1087
Christoph Lameter6cb06222007-10-16 01:25:41 -07001088 BUG_ON(flags & GFP_SLAB_BUG_MASK);
Christoph Lameter81819f02007-05-06 14:49:36 -07001089
Christoph Lameter6cb06222007-10-16 01:25:41 -07001090 page = allocate_slab(s,
1091 flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
Christoph Lameter81819f02007-05-06 14:49:36 -07001092 if (!page)
1093 goto out;
1094
1095 n = get_node(s, page_to_nid(page));
1096 if (n)
1097 atomic_long_inc(&n->nr_slabs);
Christoph Lameter81819f02007-05-06 14:49:36 -07001098 page->slab = s;
1099 page->flags |= 1 << PG_slab;
1100 if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
1101 SLAB_STORE_USER | SLAB_TRACE))
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07001102 SetSlabDebug(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001103
1104 start = page_address(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001105
1106 if (unlikely(s->flags & SLAB_POISON))
1107 memset(start, POISON_INUSE, PAGE_SIZE << s->order);
1108
1109 last = start;
Christoph Lameter7656c722007-05-09 02:32:40 -07001110 for_each_object(p, s, start) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001111 setup_object(s, page, last);
1112 set_freepointer(s, last, p);
1113 last = p;
1114 }
1115 setup_object(s, page, last);
1116 set_freepointer(s, last, NULL);
1117
1118 page->freelist = start;
1119 page->inuse = 0;
1120out:
Christoph Lameter81819f02007-05-06 14:49:36 -07001121 return page;
1122}
1123
1124static void __free_slab(struct kmem_cache *s, struct page *page)
1125{
1126 int pages = 1 << s->order;
1127
Christoph Lameterc59def9f2007-05-16 22:10:50 -07001128 if (unlikely(SlabDebug(page))) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001129 void *p;
1130
1131 slab_pad_check(s, page);
Christoph Lameterc59def9f2007-05-16 22:10:50 -07001132 for_each_object(p, s, page_address(page))
Christoph Lameter81819f02007-05-06 14:49:36 -07001133 check_object(s, page, p, 0);
Peter Zijlstra2208b762007-07-26 20:54:34 +02001134 ClearSlabDebug(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001135 }
1136
1137 mod_zone_page_state(page_zone(page),
1138 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1139 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
Pekka Enberg06428782008-01-07 23:20:27 -08001140 -pages);
Christoph Lameter81819f02007-05-06 14:49:36 -07001141
Christoph Lameter81819f02007-05-06 14:49:36 -07001142 __free_pages(page, s->order);
1143}
1144
1145static void rcu_free_slab(struct rcu_head *h)
1146{
1147 struct page *page;
1148
1149 page = container_of((struct list_head *)h, struct page, lru);
1150 __free_slab(page->slab, page);
1151}
1152
1153static void free_slab(struct kmem_cache *s, struct page *page)
1154{
1155 if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
1156 /*
1157 * RCU free overloads the RCU head over the LRU
1158 */
1159 struct rcu_head *head = (void *)&page->lru;
1160
1161 call_rcu(head, rcu_free_slab);
1162 } else
1163 __free_slab(s, page);
1164}
1165
1166static void discard_slab(struct kmem_cache *s, struct page *page)
1167{
1168 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1169
1170 atomic_long_dec(&n->nr_slabs);
1171 reset_page_mapcount(page);
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07001172 __ClearPageSlab(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001173 free_slab(s, page);
1174}
1175
1176/*
1177 * Per slab locking using the pagelock
1178 */
1179static __always_inline void slab_lock(struct page *page)
1180{
1181 bit_spin_lock(PG_locked, &page->flags);
1182}
1183
1184static __always_inline void slab_unlock(struct page *page)
1185{
1186 bit_spin_unlock(PG_locked, &page->flags);
1187}
1188
1189static __always_inline int slab_trylock(struct page *page)
1190{
1191 int rc = 1;
1192
1193 rc = bit_spin_trylock(PG_locked, &page->flags);
1194 return rc;
1195}
1196
1197/*
1198 * Management of partially allocated slabs
1199 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001200static void add_partial(struct kmem_cache_node *n,
1201 struct page *page, int tail)
Christoph Lameter81819f02007-05-06 14:49:36 -07001202{
Christoph Lametere95eed52007-05-06 14:49:44 -07001203 spin_lock(&n->list_lock);
1204 n->nr_partial++;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001205 if (tail)
1206 list_add_tail(&page->lru, &n->partial);
1207 else
1208 list_add(&page->lru, &n->partial);
Christoph Lameter81819f02007-05-06 14:49:36 -07001209 spin_unlock(&n->list_lock);
1210}
1211
1212static void remove_partial(struct kmem_cache *s,
1213 struct page *page)
1214{
1215 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1216
1217 spin_lock(&n->list_lock);
1218 list_del(&page->lru);
1219 n->nr_partial--;
1220 spin_unlock(&n->list_lock);
1221}
1222
1223/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001224 * Lock slab and remove from the partial list.
Christoph Lameter81819f02007-05-06 14:49:36 -07001225 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001226 * Must hold list_lock.
Christoph Lameter81819f02007-05-06 14:49:36 -07001227 */
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001228static inline int lock_and_freeze_slab(struct kmem_cache_node *n, struct page *page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001229{
1230 if (slab_trylock(page)) {
1231 list_del(&page->lru);
1232 n->nr_partial--;
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001233 SetSlabFrozen(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001234 return 1;
1235 }
1236 return 0;
1237}
1238
1239/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001240 * Try to allocate a partial slab from a specific node.
Christoph Lameter81819f02007-05-06 14:49:36 -07001241 */
1242static struct page *get_partial_node(struct kmem_cache_node *n)
1243{
1244 struct page *page;
1245
1246 /*
1247 * Racy check. If we mistakenly see no partial slabs then we
1248 * just allocate an empty slab. If we mistakenly try to get a
Christoph Lameter672bba32007-05-09 02:32:39 -07001249 * partial slab and there is none available then get_partials()
1250 * will return NULL.
Christoph Lameter81819f02007-05-06 14:49:36 -07001251 */
1252 if (!n || !n->nr_partial)
1253 return NULL;
1254
1255 spin_lock(&n->list_lock);
1256 list_for_each_entry(page, &n->partial, lru)
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001257 if (lock_and_freeze_slab(n, page))
Christoph Lameter81819f02007-05-06 14:49:36 -07001258 goto out;
1259 page = NULL;
1260out:
1261 spin_unlock(&n->list_lock);
1262 return page;
1263}
1264
1265/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001266 * Get a page from somewhere. Search in increasing NUMA distances.
Christoph Lameter81819f02007-05-06 14:49:36 -07001267 */
1268static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
1269{
1270#ifdef CONFIG_NUMA
1271 struct zonelist *zonelist;
1272 struct zone **z;
1273 struct page *page;
1274
1275 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001276 * The defrag ratio allows a configuration of the tradeoffs between
1277 * inter node defragmentation and node local allocations. A lower
1278 * defrag_ratio increases the tendency to do local allocations
1279 * instead of attempting to obtain partial slabs from other nodes.
Christoph Lameter81819f02007-05-06 14:49:36 -07001280 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001281 * If the defrag_ratio is set to 0 then kmalloc() always
1282 * returns node local objects. If the ratio is higher then kmalloc()
1283 * may return off node objects because partial slabs are obtained
1284 * from other nodes and filled up.
Christoph Lameter81819f02007-05-06 14:49:36 -07001285 *
1286 * If /sys/slab/xx/defrag_ratio is set to 100 (which makes
Christoph Lameter672bba32007-05-09 02:32:39 -07001287 * defrag_ratio = 1000) then every (well almost) allocation will
1288 * first attempt to defrag slab caches on other nodes. This means
1289 * scanning over all nodes to look for partial slabs which may be
1290 * expensive if we do it every time we are trying to find a slab
1291 * with available objects.
Christoph Lameter81819f02007-05-06 14:49:36 -07001292 */
Christoph Lameter98246012008-01-07 23:20:26 -08001293 if (!s->remote_node_defrag_ratio ||
1294 get_cycles() % 1024 > s->remote_node_defrag_ratio)
Christoph Lameter81819f02007-05-06 14:49:36 -07001295 return NULL;
1296
1297 zonelist = &NODE_DATA(slab_node(current->mempolicy))
1298 ->node_zonelists[gfp_zone(flags)];
1299 for (z = zonelist->zones; *z; z++) {
1300 struct kmem_cache_node *n;
1301
1302 n = get_node(s, zone_to_nid(*z));
1303
1304 if (n && cpuset_zone_allowed_hardwall(*z, flags) &&
Christoph Lametere95eed52007-05-06 14:49:44 -07001305 n->nr_partial > MIN_PARTIAL) {
Christoph Lameter81819f02007-05-06 14:49:36 -07001306 page = get_partial_node(n);
1307 if (page)
1308 return page;
1309 }
1310 }
1311#endif
1312 return NULL;
1313}
1314
1315/*
1316 * Get a partial page, lock it and return it.
1317 */
1318static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
1319{
1320 struct page *page;
1321 int searchnode = (node == -1) ? numa_node_id() : node;
1322
1323 page = get_partial_node(get_node(s, searchnode));
1324 if (page || (flags & __GFP_THISNODE))
1325 return page;
1326
1327 return get_any_partial(s, flags);
1328}
1329
1330/*
1331 * Move a page back to the lists.
1332 *
1333 * Must be called with the slab lock held.
1334 *
1335 * On exit the slab lock will have been dropped.
1336 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001337static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
Christoph Lameter81819f02007-05-06 14:49:36 -07001338{
Christoph Lametere95eed52007-05-06 14:49:44 -07001339 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1340
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001341 ClearSlabFrozen(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001342 if (page->inuse) {
Christoph Lametere95eed52007-05-06 14:49:44 -07001343
Christoph Lameter81819f02007-05-06 14:49:36 -07001344 if (page->freelist)
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001345 add_partial(n, page, tail);
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07001346 else if (SlabDebug(page) && (s->flags & SLAB_STORE_USER))
Christoph Lametere95eed52007-05-06 14:49:44 -07001347 add_full(n, page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001348 slab_unlock(page);
Christoph Lametere95eed52007-05-06 14:49:44 -07001349
Christoph Lameter81819f02007-05-06 14:49:36 -07001350 } else {
Christoph Lametere95eed52007-05-06 14:49:44 -07001351 if (n->nr_partial < MIN_PARTIAL) {
1352 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001353 * Adding an empty slab to the partial slabs in order
1354 * to avoid page allocator overhead. This slab needs
1355 * to come after the other slabs with objects in
1356 * order to fill them up. That way the size of the
1357 * partial list stays small. kmem_cache_shrink can
1358 * reclaim empty slabs from the partial list.
Christoph Lametere95eed52007-05-06 14:49:44 -07001359 */
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001360 add_partial(n, page, 1);
Christoph Lametere95eed52007-05-06 14:49:44 -07001361 slab_unlock(page);
1362 } else {
1363 slab_unlock(page);
1364 discard_slab(s, page);
1365 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001366 }
1367}
1368
1369/*
1370 * Remove the cpu slab
1371 */
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001372static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001373{
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001374 struct page *page = c->page;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001375 int tail = 1;
Christoph Lameter894b8782007-05-10 03:15:16 -07001376 /*
1377 * Merge cpu freelist into freelist. Typically we get here
1378 * because both freelists are empty. So this is unlikely
1379 * to occur.
1380 */
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001381 while (unlikely(c->freelist)) {
Christoph Lameter894b8782007-05-10 03:15:16 -07001382 void **object;
1383
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001384 tail = 0; /* Hot objects. Put the slab first */
1385
Christoph Lameter894b8782007-05-10 03:15:16 -07001386 /* Retrieve object from cpu_freelist */
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001387 object = c->freelist;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001388 c->freelist = c->freelist[c->offset];
Christoph Lameter894b8782007-05-10 03:15:16 -07001389
1390 /* And put onto the regular freelist */
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001391 object[c->offset] = page->freelist;
Christoph Lameter894b8782007-05-10 03:15:16 -07001392 page->freelist = object;
1393 page->inuse--;
1394 }
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001395 c->page = NULL;
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001396 unfreeze_slab(s, page, tail);
Christoph Lameter81819f02007-05-06 14:49:36 -07001397}
1398
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001399static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001400{
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001401 slab_lock(c->page);
1402 deactivate_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001403}
1404
1405/*
1406 * Flush cpu slab.
1407 * Called from IPI handler with interrupts disabled.
1408 */
Christoph Lameter0c710012007-07-17 04:03:24 -07001409static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
Christoph Lameter81819f02007-05-06 14:49:36 -07001410{
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001411 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameter81819f02007-05-06 14:49:36 -07001412
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001413 if (likely(c && c->page))
1414 flush_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001415}
1416
1417static void flush_cpu_slab(void *d)
1418{
1419 struct kmem_cache *s = d;
Christoph Lameter81819f02007-05-06 14:49:36 -07001420
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001421 __flush_cpu_slab(s, smp_processor_id());
Christoph Lameter81819f02007-05-06 14:49:36 -07001422}
1423
1424static void flush_all(struct kmem_cache *s)
1425{
1426#ifdef CONFIG_SMP
1427 on_each_cpu(flush_cpu_slab, s, 1, 1);
1428#else
1429 unsigned long flags;
1430
1431 local_irq_save(flags);
1432 flush_cpu_slab(s);
1433 local_irq_restore(flags);
1434#endif
1435}
1436
1437/*
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001438 * Check if the objects in a per cpu structure fit numa
1439 * locality expectations.
1440 */
1441static inline int node_match(struct kmem_cache_cpu *c, int node)
1442{
1443#ifdef CONFIG_NUMA
1444 if (node != -1 && c->node != node)
1445 return 0;
1446#endif
1447 return 1;
1448}
1449
1450/*
Christoph Lameter894b8782007-05-10 03:15:16 -07001451 * Slow path. The lockless freelist is empty or we need to perform
1452 * debugging duties.
Christoph Lameter81819f02007-05-06 14:49:36 -07001453 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001454 * Interrupts are disabled.
Christoph Lameter81819f02007-05-06 14:49:36 -07001455 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001456 * Processing is still very fast if new objects have been freed to the
1457 * regular freelist. In that case we simply take over the regular freelist
1458 * as the lockless freelist and zap the regular freelist.
Christoph Lameter81819f02007-05-06 14:49:36 -07001459 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001460 * If that is not working then we fall back to the partial lists. We take the
1461 * first element of the freelist as the object to allocate now and move the
1462 * rest of the freelist to the lockless freelist.
1463 *
1464 * And if we were unable to get a new slab from the partial slab lists then
1465 * we need to allocate a new slab. This is slowest path since we may sleep.
Christoph Lameter81819f02007-05-06 14:49:36 -07001466 */
Christoph Lameter894b8782007-05-10 03:15:16 -07001467static void *__slab_alloc(struct kmem_cache *s,
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001468 gfp_t gfpflags, int node, void *addr, struct kmem_cache_cpu *c)
Christoph Lameter81819f02007-05-06 14:49:36 -07001469{
Christoph Lameter81819f02007-05-06 14:49:36 -07001470 void **object;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001471 struct page *new;
Christoph Lameter81819f02007-05-06 14:49:36 -07001472
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001473 if (!c->page)
Christoph Lameter81819f02007-05-06 14:49:36 -07001474 goto new_slab;
1475
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001476 slab_lock(c->page);
1477 if (unlikely(!node_match(c, node)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001478 goto another_slab;
Christoph Lameter894b8782007-05-10 03:15:16 -07001479load_freelist:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001480 object = c->page->freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001481 if (unlikely(!object))
1482 goto another_slab;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001483 if (unlikely(SlabDebug(c->page)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001484 goto debug;
1485
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001486 object = c->page->freelist;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001487 c->freelist = object[c->offset];
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001488 c->page->inuse = s->objects;
1489 c->page->freelist = NULL;
1490 c->node = page_to_nid(c->page);
1491 slab_unlock(c->page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001492 return object;
1493
1494another_slab:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001495 deactivate_slab(s, c);
Christoph Lameter81819f02007-05-06 14:49:36 -07001496
1497new_slab:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001498 new = get_partial(s, gfpflags, node);
1499 if (new) {
1500 c->page = new;
Christoph Lameter894b8782007-05-10 03:15:16 -07001501 goto load_freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001502 }
1503
Christoph Lameterb811c202007-10-16 23:25:51 -07001504 if (gfpflags & __GFP_WAIT)
1505 local_irq_enable();
1506
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001507 new = new_slab(s, gfpflags, node);
Christoph Lameterb811c202007-10-16 23:25:51 -07001508
1509 if (gfpflags & __GFP_WAIT)
1510 local_irq_disable();
1511
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001512 if (new) {
1513 c = get_cpu_slab(s, smp_processor_id());
Christoph Lameter05aa3452007-11-05 11:31:58 -08001514 if (c->page)
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001515 flush_slab(s, c);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001516 slab_lock(new);
1517 SetSlabFrozen(new);
1518 c->page = new;
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001519 goto load_freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001520 }
Christoph Lameter81819f02007-05-06 14:49:36 -07001521 return NULL;
1522debug:
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001523 object = c->page->freelist;
1524 if (!alloc_debug_processing(s, c->page, object, addr))
Christoph Lameter81819f02007-05-06 14:49:36 -07001525 goto another_slab;
Christoph Lameter894b8782007-05-10 03:15:16 -07001526
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001527 c->page->inuse++;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001528 c->page->freelist = object[c->offset];
Christoph Lameteree3c72a2007-10-16 01:26:07 -07001529 c->node = -1;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001530 slab_unlock(c->page);
Christoph Lameter894b8782007-05-10 03:15:16 -07001531 return object;
1532}
1533
1534/*
1535 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1536 * have the fastpath folded into their functions. So no function call
1537 * overhead for requests that can be satisfied on the fastpath.
1538 *
1539 * The fastpath works by first checking if the lockless freelist can be used.
1540 * If not then __slab_alloc is called for slow processing.
1541 *
1542 * Otherwise we can simply pick the next object from the lockless free list.
1543 */
Pekka Enberg06428782008-01-07 23:20:27 -08001544static __always_inline void *slab_alloc(struct kmem_cache *s,
Christoph Lameterce15fea2007-07-17 04:03:28 -07001545 gfp_t gfpflags, int node, void *addr)
Christoph Lameter894b8782007-05-10 03:15:16 -07001546{
Christoph Lameter894b8782007-05-10 03:15:16 -07001547 void **object;
1548 unsigned long flags;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001549 struct kmem_cache_cpu *c;
Christoph Lameter894b8782007-05-10 03:15:16 -07001550
1551 local_irq_save(flags);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001552 c = get_cpu_slab(s, smp_processor_id());
Christoph Lameteree3c72a2007-10-16 01:26:07 -07001553 if (unlikely(!c->freelist || !node_match(c, node)))
Christoph Lameter894b8782007-05-10 03:15:16 -07001554
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001555 object = __slab_alloc(s, gfpflags, node, addr, c);
Christoph Lameter894b8782007-05-10 03:15:16 -07001556
1557 else {
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001558 object = c->freelist;
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001559 c->freelist = object[c->offset];
Christoph Lameter894b8782007-05-10 03:15:16 -07001560 }
1561 local_irq_restore(flags);
Christoph Lameterd07dbea2007-07-17 04:03:23 -07001562
1563 if (unlikely((gfpflags & __GFP_ZERO) && object))
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07001564 memset(object, 0, c->objsize);
Christoph Lameterd07dbea2007-07-17 04:03:23 -07001565
Christoph Lameter894b8782007-05-10 03:15:16 -07001566 return object;
Christoph Lameter81819f02007-05-06 14:49:36 -07001567}
1568
1569void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
1570{
Christoph Lameterce15fea2007-07-17 04:03:28 -07001571 return slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001572}
1573EXPORT_SYMBOL(kmem_cache_alloc);
1574
1575#ifdef CONFIG_NUMA
1576void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
1577{
Christoph Lameterce15fea2007-07-17 04:03:28 -07001578 return slab_alloc(s, gfpflags, node, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001579}
1580EXPORT_SYMBOL(kmem_cache_alloc_node);
1581#endif
1582
1583/*
Christoph Lameter894b8782007-05-10 03:15:16 -07001584 * Slow patch handling. This may still be called frequently since objects
1585 * have a longer lifetime than the cpu slabs in most processing loads.
Christoph Lameter81819f02007-05-06 14:49:36 -07001586 *
Christoph Lameter894b8782007-05-10 03:15:16 -07001587 * So we still attempt to reduce cache line usage. Just take the slab
1588 * lock and free the item. If there is no additional partial page
1589 * handling required then we can return immediately.
Christoph Lameter81819f02007-05-06 14:49:36 -07001590 */
Christoph Lameter894b8782007-05-10 03:15:16 -07001591static void __slab_free(struct kmem_cache *s, struct page *page,
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001592 void *x, void *addr, unsigned int offset)
Christoph Lameter81819f02007-05-06 14:49:36 -07001593{
1594 void *prior;
1595 void **object = (void *)x;
Christoph Lameter81819f02007-05-06 14:49:36 -07001596
Christoph Lameter81819f02007-05-06 14:49:36 -07001597 slab_lock(page);
1598
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07001599 if (unlikely(SlabDebug(page)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001600 goto debug;
1601checks_ok:
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001602 prior = object[offset] = page->freelist;
Christoph Lameter81819f02007-05-06 14:49:36 -07001603 page->freelist = object;
1604 page->inuse--;
1605
Christoph Lameter4b6f0752007-05-16 22:10:53 -07001606 if (unlikely(SlabFrozen(page)))
Christoph Lameter81819f02007-05-06 14:49:36 -07001607 goto out_unlock;
1608
1609 if (unlikely(!page->inuse))
1610 goto slab_empty;
1611
1612 /*
1613 * Objects left in the slab. If it
1614 * was not on the partial list before
1615 * then add it.
1616 */
1617 if (unlikely(!prior))
Christoph Lameter7c2e1322008-01-07 23:20:27 -08001618 add_partial(get_node(s, page_to_nid(page)), page, 1);
Christoph Lameter81819f02007-05-06 14:49:36 -07001619
1620out_unlock:
1621 slab_unlock(page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001622 return;
1623
1624slab_empty:
1625 if (prior)
1626 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07001627 * Slab still on the partial list.
Christoph Lameter81819f02007-05-06 14:49:36 -07001628 */
1629 remove_partial(s, page);
1630
1631 slab_unlock(page);
1632 discard_slab(s, page);
Christoph Lameter81819f02007-05-06 14:49:36 -07001633 return;
1634
1635debug:
Christoph Lameter3ec09742007-05-16 22:11:00 -07001636 if (!free_debug_processing(s, page, x, addr))
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001637 goto out_unlock;
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001638 goto checks_ok;
Christoph Lameter81819f02007-05-06 14:49:36 -07001639}
1640
Christoph Lameter894b8782007-05-10 03:15:16 -07001641/*
1642 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
1643 * can perform fastpath freeing without additional function calls.
1644 *
1645 * The fastpath is only possible if we are freeing to the current cpu slab
1646 * of this processor. This typically the case if we have just allocated
1647 * the item before.
1648 *
1649 * If fastpath is not possible then fall back to __slab_free where we deal
1650 * with all sorts of special processing.
1651 */
Pekka Enberg06428782008-01-07 23:20:27 -08001652static __always_inline void slab_free(struct kmem_cache *s,
Christoph Lameter894b8782007-05-10 03:15:16 -07001653 struct page *page, void *x, void *addr)
1654{
1655 void **object = (void *)x;
1656 unsigned long flags;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001657 struct kmem_cache_cpu *c;
Christoph Lameter894b8782007-05-10 03:15:16 -07001658
1659 local_irq_save(flags);
Peter Zijlstra02febdf2007-07-26 20:01:38 +02001660 debug_check_no_locks_freed(object, s->objsize);
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001661 c = get_cpu_slab(s, smp_processor_id());
Christoph Lameteree3c72a2007-10-16 01:26:07 -07001662 if (likely(page == c->page && c->node >= 0)) {
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001663 object[c->offset] = c->freelist;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001664 c->freelist = object;
Christoph Lameter894b8782007-05-10 03:15:16 -07001665 } else
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07001666 __slab_free(s, page, x, addr, c->offset);
Christoph Lameter894b8782007-05-10 03:15:16 -07001667
1668 local_irq_restore(flags);
1669}
1670
Christoph Lameter81819f02007-05-06 14:49:36 -07001671void kmem_cache_free(struct kmem_cache *s, void *x)
1672{
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001673 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07001674
Christoph Lameterb49af682007-05-06 14:49:41 -07001675 page = virt_to_head_page(x);
Christoph Lameter81819f02007-05-06 14:49:36 -07001676
Christoph Lameter77c5e2d2007-05-06 14:49:42 -07001677 slab_free(s, page, x, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07001678}
1679EXPORT_SYMBOL(kmem_cache_free);
1680
1681/* Figure out on which slab object the object resides */
1682static struct page *get_object_page(const void *x)
1683{
Christoph Lameterb49af682007-05-06 14:49:41 -07001684 struct page *page = virt_to_head_page(x);
Christoph Lameter81819f02007-05-06 14:49:36 -07001685
1686 if (!PageSlab(page))
1687 return NULL;
1688
1689 return page;
1690}
1691
1692/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001693 * Object placement in a slab is made very easy because we always start at
1694 * offset 0. If we tune the size of the object to the alignment then we can
1695 * get the required alignment by putting one properly sized object after
1696 * another.
Christoph Lameter81819f02007-05-06 14:49:36 -07001697 *
1698 * Notice that the allocation order determines the sizes of the per cpu
1699 * caches. Each processor has always one slab available for allocations.
1700 * Increasing the allocation order reduces the number of times that slabs
Christoph Lameter672bba32007-05-09 02:32:39 -07001701 * must be moved on and off the partial lists and is therefore a factor in
Christoph Lameter81819f02007-05-06 14:49:36 -07001702 * locking overhead.
Christoph Lameter81819f02007-05-06 14:49:36 -07001703 */
1704
1705/*
1706 * Mininum / Maximum order of slab pages. This influences locking overhead
1707 * and slab fragmentation. A higher order reduces the number of partial slabs
1708 * and increases the number of allocations possible without having to
1709 * take the list_lock.
1710 */
1711static int slub_min_order;
1712static int slub_max_order = DEFAULT_MAX_ORDER;
Christoph Lameter81819f02007-05-06 14:49:36 -07001713static int slub_min_objects = DEFAULT_MIN_OBJECTS;
1714
1715/*
1716 * Merge control. If this is set then no merging of slab caches will occur.
Christoph Lameter672bba32007-05-09 02:32:39 -07001717 * (Could be removed. This was introduced to pacify the merge skeptics.)
Christoph Lameter81819f02007-05-06 14:49:36 -07001718 */
1719static int slub_nomerge;
1720
1721/*
Christoph Lameter81819f02007-05-06 14:49:36 -07001722 * Calculate the order of allocation given an slab object size.
1723 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001724 * The order of allocation has significant impact on performance and other
1725 * system components. Generally order 0 allocations should be preferred since
1726 * order 0 does not cause fragmentation in the page allocator. Larger objects
1727 * be problematic to put into order 0 slabs because there may be too much
1728 * unused space left. We go to a higher order if more than 1/8th of the slab
1729 * would be wasted.
Christoph Lameter81819f02007-05-06 14:49:36 -07001730 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001731 * In order to reach satisfactory performance we must ensure that a minimum
1732 * number of objects is in one slab. Otherwise we may generate too much
1733 * activity on the partial lists which requires taking the list_lock. This is
1734 * less a concern for large slabs though which are rarely used.
Christoph Lameter81819f02007-05-06 14:49:36 -07001735 *
Christoph Lameter672bba32007-05-09 02:32:39 -07001736 * slub_max_order specifies the order where we begin to stop considering the
1737 * number of objects in a slab as critical. If we reach slub_max_order then
1738 * we try to keep the page order as low as possible. So we accept more waste
1739 * of space in favor of a small page order.
1740 *
1741 * Higher order allocations also allow the placement of more objects in a
1742 * slab and thereby reduce object handling overhead. If the user has
1743 * requested a higher mininum order then we start with that one instead of
1744 * the smallest order which will fit the object.
Christoph Lameter81819f02007-05-06 14:49:36 -07001745 */
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001746static inline int slab_order(int size, int min_objects,
1747 int max_order, int fract_leftover)
Christoph Lameter81819f02007-05-06 14:49:36 -07001748{
1749 int order;
1750 int rem;
Christoph Lameter6300ea72007-07-17 04:03:20 -07001751 int min_order = slub_min_order;
Christoph Lameter81819f02007-05-06 14:49:36 -07001752
Christoph Lameter6300ea72007-07-17 04:03:20 -07001753 for (order = max(min_order,
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001754 fls(min_objects * size - 1) - PAGE_SHIFT);
1755 order <= max_order; order++) {
1756
Christoph Lameter81819f02007-05-06 14:49:36 -07001757 unsigned long slab_size = PAGE_SIZE << order;
1758
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001759 if (slab_size < min_objects * size)
Christoph Lameter81819f02007-05-06 14:49:36 -07001760 continue;
1761
Christoph Lameter81819f02007-05-06 14:49:36 -07001762 rem = slab_size % size;
1763
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001764 if (rem <= slab_size / fract_leftover)
Christoph Lameter81819f02007-05-06 14:49:36 -07001765 break;
1766
1767 }
Christoph Lameter672bba32007-05-09 02:32:39 -07001768
Christoph Lameter81819f02007-05-06 14:49:36 -07001769 return order;
1770}
1771
Christoph Lameter5e6d4442007-05-09 02:32:46 -07001772static inline int calculate_order(int size)
1773{
1774 int order;
1775 int min_objects;
1776 int fraction;
1777
1778 /*
1779 * Attempt to find best configuration for a slab. This
1780 * works by first attempting to generate a layout with
1781 * the best configuration and backing off gradually.
1782 *
1783 * First we reduce the acceptable waste in a slab. Then
1784 * we reduce the minimum objects required in a slab.
1785 */
1786 min_objects = slub_min_objects;
1787 while (min_objects > 1) {
1788 fraction = 8;
1789 while (fraction >= 4) {
1790 order = slab_order(size, min_objects,
1791 slub_max_order, fraction);
1792 if (order <= slub_max_order)
1793 return order;
1794 fraction /= 2;
1795 }
1796 min_objects /= 2;
1797 }
1798
1799 /*
1800 * We were unable to place multiple objects in a slab. Now
1801 * lets see if we can place a single object there.
1802 */
1803 order = slab_order(size, 1, slub_max_order, 1);
1804 if (order <= slub_max_order)
1805 return order;
1806
1807 /*
1808 * Doh this slab cannot be placed using slub_max_order.
1809 */
1810 order = slab_order(size, 1, MAX_ORDER, 1);
1811 if (order <= MAX_ORDER)
1812 return order;
1813 return -ENOSYS;
1814}
1815
Christoph Lameter81819f02007-05-06 14:49:36 -07001816/*
Christoph Lameter672bba32007-05-09 02:32:39 -07001817 * Figure out what the alignment of the objects will be.
Christoph Lameter81819f02007-05-06 14:49:36 -07001818 */
1819static unsigned long calculate_alignment(unsigned long flags,
1820 unsigned long align, unsigned long size)
1821{
1822 /*
1823 * If the user wants hardware cache aligned objects then
1824 * follow that suggestion if the object is sufficiently
1825 * large.
1826 *
1827 * The hardware cache alignment cannot override the
1828 * specified alignment though. If that is greater
1829 * then use it.
1830 */
Christoph Lameter5af60832007-05-06 14:49:56 -07001831 if ((flags & SLAB_HWCACHE_ALIGN) &&
Christoph Lameter65c02d42007-05-09 02:32:35 -07001832 size > cache_line_size() / 2)
1833 return max_t(unsigned long, align, cache_line_size());
Christoph Lameter81819f02007-05-06 14:49:36 -07001834
1835 if (align < ARCH_SLAB_MINALIGN)
1836 return ARCH_SLAB_MINALIGN;
1837
1838 return ALIGN(align, sizeof(void *));
1839}
1840
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001841static void init_kmem_cache_cpu(struct kmem_cache *s,
1842 struct kmem_cache_cpu *c)
1843{
1844 c->page = NULL;
1845 c->freelist = NULL;
1846 c->node = 0;
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07001847 c->offset = s->offset / sizeof(void *);
1848 c->objsize = s->objsize;
Christoph Lameterdfb4f092007-10-16 01:26:05 -07001849}
1850
Christoph Lameter81819f02007-05-06 14:49:36 -07001851static void init_kmem_cache_node(struct kmem_cache_node *n)
1852{
1853 n->nr_partial = 0;
1854 atomic_long_set(&n->nr_slabs, 0);
1855 spin_lock_init(&n->list_lock);
1856 INIT_LIST_HEAD(&n->partial);
Christoph Lameter8ab13722007-07-17 04:03:32 -07001857#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter643b1132007-05-06 14:49:42 -07001858 INIT_LIST_HEAD(&n->full);
Christoph Lameter8ab13722007-07-17 04:03:32 -07001859#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07001860}
1861
Christoph Lameter4c93c3552007-10-16 01:26:08 -07001862#ifdef CONFIG_SMP
1863/*
1864 * Per cpu array for per cpu structures.
1865 *
1866 * The per cpu array places all kmem_cache_cpu structures from one processor
1867 * close together meaning that it becomes possible that multiple per cpu
1868 * structures are contained in one cacheline. This may be particularly
1869 * beneficial for the kmalloc caches.
1870 *
1871 * A desktop system typically has around 60-80 slabs. With 100 here we are
1872 * likely able to get per cpu structures for all caches from the array defined
1873 * here. We must be able to cover all kmalloc caches during bootstrap.
1874 *
1875 * If the per cpu array is exhausted then fall back to kmalloc
1876 * of individual cachelines. No sharing is possible then.
1877 */
1878#define NR_KMEM_CACHE_CPU 100
1879
1880static DEFINE_PER_CPU(struct kmem_cache_cpu,
1881 kmem_cache_cpu)[NR_KMEM_CACHE_CPU];
1882
1883static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free);
1884static cpumask_t kmem_cach_cpu_free_init_once = CPU_MASK_NONE;
1885
1886static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s,
1887 int cpu, gfp_t flags)
1888{
1889 struct kmem_cache_cpu *c = per_cpu(kmem_cache_cpu_free, cpu);
1890
1891 if (c)
1892 per_cpu(kmem_cache_cpu_free, cpu) =
1893 (void *)c->freelist;
1894 else {
1895 /* Table overflow: So allocate ourselves */
1896 c = kmalloc_node(
1897 ALIGN(sizeof(struct kmem_cache_cpu), cache_line_size()),
1898 flags, cpu_to_node(cpu));
1899 if (!c)
1900 return NULL;
1901 }
1902
1903 init_kmem_cache_cpu(s, c);
1904 return c;
1905}
1906
1907static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu)
1908{
1909 if (c < per_cpu(kmem_cache_cpu, cpu) ||
1910 c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
1911 kfree(c);
1912 return;
1913 }
1914 c->freelist = (void *)per_cpu(kmem_cache_cpu_free, cpu);
1915 per_cpu(kmem_cache_cpu_free, cpu) = c;
1916}
1917
1918static void free_kmem_cache_cpus(struct kmem_cache *s)
1919{
1920 int cpu;
1921
1922 for_each_online_cpu(cpu) {
1923 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
1924
1925 if (c) {
1926 s->cpu_slab[cpu] = NULL;
1927 free_kmem_cache_cpu(c, cpu);
1928 }
1929 }
1930}
1931
1932static int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
1933{
1934 int cpu;
1935
1936 for_each_online_cpu(cpu) {
1937 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
1938
1939 if (c)
1940 continue;
1941
1942 c = alloc_kmem_cache_cpu(s, cpu, flags);
1943 if (!c) {
1944 free_kmem_cache_cpus(s);
1945 return 0;
1946 }
1947 s->cpu_slab[cpu] = c;
1948 }
1949 return 1;
1950}
1951
1952/*
1953 * Initialize the per cpu array.
1954 */
1955static void init_alloc_cpu_cpu(int cpu)
1956{
1957 int i;
1958
1959 if (cpu_isset(cpu, kmem_cach_cpu_free_init_once))
1960 return;
1961
1962 for (i = NR_KMEM_CACHE_CPU - 1; i >= 0; i--)
1963 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu, cpu)[i], cpu);
1964
1965 cpu_set(cpu, kmem_cach_cpu_free_init_once);
1966}
1967
1968static void __init init_alloc_cpu(void)
1969{
1970 int cpu;
1971
1972 for_each_online_cpu(cpu)
1973 init_alloc_cpu_cpu(cpu);
1974 }
1975
1976#else
1977static inline void free_kmem_cache_cpus(struct kmem_cache *s) {}
1978static inline void init_alloc_cpu(void) {}
1979
1980static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
1981{
1982 init_kmem_cache_cpu(s, &s->cpu_slab);
1983 return 1;
1984}
1985#endif
1986
Christoph Lameter81819f02007-05-06 14:49:36 -07001987#ifdef CONFIG_NUMA
1988/*
1989 * No kmalloc_node yet so do it by hand. We know that this is the first
1990 * slab on the node for this slabcache. There are no concurrent accesses
1991 * possible.
1992 *
1993 * Note that this function only works on the kmalloc_node_cache
Christoph Lameter4c93c3552007-10-16 01:26:08 -07001994 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
1995 * memory on a fresh node that has no slab structures yet.
Christoph Lameter81819f02007-05-06 14:49:36 -07001996 */
Adrian Bunk1cd7daa2007-10-16 01:24:18 -07001997static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags,
1998 int node)
Christoph Lameter81819f02007-05-06 14:49:36 -07001999{
2000 struct page *page;
2001 struct kmem_cache_node *n;
rootba84c732008-01-07 23:20:28 -08002002 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07002003
2004 BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node));
2005
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002006 page = new_slab(kmalloc_caches, gfpflags, node);
Christoph Lameter81819f02007-05-06 14:49:36 -07002007
2008 BUG_ON(!page);
Christoph Lametera2f92ee2007-08-22 14:01:57 -07002009 if (page_to_nid(page) != node) {
2010 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2011 "node %d\n", node);
2012 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2013 "in order to be able to continue\n");
2014 }
2015
Christoph Lameter81819f02007-05-06 14:49:36 -07002016 n = page->freelist;
2017 BUG_ON(!n);
2018 page->freelist = get_freepointer(kmalloc_caches, n);
2019 page->inuse++;
2020 kmalloc_caches->node[node] = n;
Christoph Lameter8ab13722007-07-17 04:03:32 -07002021#ifdef CONFIG_SLUB_DEBUG
Christoph Lameterd45f39c2007-07-17 04:03:21 -07002022 init_object(kmalloc_caches, n, 1);
2023 init_tracking(kmalloc_caches, n);
Christoph Lameter8ab13722007-07-17 04:03:32 -07002024#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002025 init_kmem_cache_node(n);
2026 atomic_long_inc(&n->nr_slabs);
rootba84c732008-01-07 23:20:28 -08002027 /*
2028 * lockdep requires consistent irq usage for each lock
2029 * so even though there cannot be a race this early in
2030 * the boot sequence, we still disable irqs.
2031 */
2032 local_irq_save(flags);
Christoph Lameter7c2e1322008-01-07 23:20:27 -08002033 add_partial(n, page, 0);
rootba84c732008-01-07 23:20:28 -08002034 local_irq_restore(flags);
Christoph Lameter81819f02007-05-06 14:49:36 -07002035 return n;
2036}
2037
2038static void free_kmem_cache_nodes(struct kmem_cache *s)
2039{
2040 int node;
2041
Christoph Lameterf64dc582007-10-16 01:25:33 -07002042 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002043 struct kmem_cache_node *n = s->node[node];
2044 if (n && n != &s->local_node)
2045 kmem_cache_free(kmalloc_caches, n);
2046 s->node[node] = NULL;
2047 }
2048}
2049
2050static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2051{
2052 int node;
2053 int local_node;
2054
2055 if (slab_state >= UP)
2056 local_node = page_to_nid(virt_to_page(s));
2057 else
2058 local_node = 0;
2059
Christoph Lameterf64dc582007-10-16 01:25:33 -07002060 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002061 struct kmem_cache_node *n;
2062
2063 if (local_node == node)
2064 n = &s->local_node;
2065 else {
2066 if (slab_state == DOWN) {
2067 n = early_kmem_cache_node_alloc(gfpflags,
2068 node);
2069 continue;
2070 }
2071 n = kmem_cache_alloc_node(kmalloc_caches,
2072 gfpflags, node);
2073
2074 if (!n) {
2075 free_kmem_cache_nodes(s);
2076 return 0;
2077 }
2078
2079 }
2080 s->node[node] = n;
2081 init_kmem_cache_node(n);
2082 }
2083 return 1;
2084}
2085#else
2086static void free_kmem_cache_nodes(struct kmem_cache *s)
2087{
2088}
2089
2090static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2091{
2092 init_kmem_cache_node(&s->local_node);
2093 return 1;
2094}
2095#endif
2096
2097/*
2098 * calculate_sizes() determines the order and the distribution of data within
2099 * a slab object.
2100 */
2101static int calculate_sizes(struct kmem_cache *s)
2102{
2103 unsigned long flags = s->flags;
2104 unsigned long size = s->objsize;
2105 unsigned long align = s->align;
2106
2107 /*
2108 * Determine if we can poison the object itself. If the user of
2109 * the slab may touch the object after free or before allocation
2110 * then we should never poison the object itself.
2111 */
2112 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002113 !s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07002114 s->flags |= __OBJECT_POISON;
2115 else
2116 s->flags &= ~__OBJECT_POISON;
2117
2118 /*
2119 * Round up object size to the next word boundary. We can only
2120 * place the free pointer at word boundaries and this determines
2121 * the possible location of the free pointer.
2122 */
2123 size = ALIGN(size, sizeof(void *));
2124
Christoph Lameter41ecc552007-05-09 02:32:44 -07002125#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002126 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002127 * If we are Redzoning then check if there is some space between the
Christoph Lameter81819f02007-05-06 14:49:36 -07002128 * end of the object and the free pointer. If not then add an
Christoph Lameter672bba32007-05-09 02:32:39 -07002129 * additional word to have some bytes to store Redzone information.
Christoph Lameter81819f02007-05-06 14:49:36 -07002130 */
2131 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2132 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002133#endif
Christoph Lameter81819f02007-05-06 14:49:36 -07002134
2135 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002136 * With that we have determined the number of bytes in actual use
2137 * by the object. This is the potential offset to the free pointer.
Christoph Lameter81819f02007-05-06 14:49:36 -07002138 */
2139 s->inuse = size;
2140
2141 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002142 s->ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002143 /*
2144 * Relocate free pointer after the object if it is not
2145 * permitted to overwrite the first word of the object on
2146 * kmem_cache_free.
2147 *
2148 * This is the case if we do RCU, have a constructor or
2149 * destructor or are poisoning the objects.
2150 */
2151 s->offset = size;
2152 size += sizeof(void *);
2153 }
2154
Christoph Lameterc12b3c62007-05-23 13:57:31 -07002155#ifdef CONFIG_SLUB_DEBUG
Christoph Lameter81819f02007-05-06 14:49:36 -07002156 if (flags & SLAB_STORE_USER)
2157 /*
2158 * Need to store information about allocs and frees after
2159 * the object.
2160 */
2161 size += 2 * sizeof(struct track);
2162
Christoph Lameterbe7b3fb2007-05-09 02:32:36 -07002163 if (flags & SLAB_RED_ZONE)
Christoph Lameter81819f02007-05-06 14:49:36 -07002164 /*
2165 * Add some empty padding so that we can catch
2166 * overwrites from earlier objects rather than let
2167 * tracking information or the free pointer be
2168 * corrupted if an user writes before the start
2169 * of the object.
2170 */
2171 size += sizeof(void *);
Christoph Lameter41ecc552007-05-09 02:32:44 -07002172#endif
Christoph Lameter672bba32007-05-09 02:32:39 -07002173
Christoph Lameter81819f02007-05-06 14:49:36 -07002174 /*
2175 * Determine the alignment based on various parameters that the
Christoph Lameter65c02d42007-05-09 02:32:35 -07002176 * user specified and the dynamic determination of cache line size
2177 * on bootup.
Christoph Lameter81819f02007-05-06 14:49:36 -07002178 */
2179 align = calculate_alignment(flags, align, s->objsize);
2180
2181 /*
2182 * SLUB stores one object immediately after another beginning from
2183 * offset 0. In order to align the objects we have to simply size
2184 * each object to conform to the alignment.
2185 */
2186 size = ALIGN(size, align);
2187 s->size = size;
2188
2189 s->order = calculate_order(size);
2190 if (s->order < 0)
2191 return 0;
2192
2193 /*
2194 * Determine the number of objects per slab
2195 */
2196 s->objects = (PAGE_SIZE << s->order) / size;
2197
Christoph Lameterb3fba8d2007-10-16 01:26:06 -07002198 return !!s->objects;
Christoph Lameter81819f02007-05-06 14:49:36 -07002199
2200}
2201
Christoph Lameter81819f02007-05-06 14:49:36 -07002202static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
2203 const char *name, size_t size,
2204 size_t align, unsigned long flags,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07002205 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07002206{
2207 memset(s, 0, kmem_size);
2208 s->name = name;
2209 s->ctor = ctor;
Christoph Lameter81819f02007-05-06 14:49:36 -07002210 s->objsize = size;
Christoph Lameter81819f02007-05-06 14:49:36 -07002211 s->align = align;
Christoph Lameterba0268a2007-09-11 15:24:11 -07002212 s->flags = kmem_cache_flags(size, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07002213
2214 if (!calculate_sizes(s))
2215 goto error;
2216
2217 s->refcount = 1;
2218#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08002219 s->remote_node_defrag_ratio = 100;
Christoph Lameter81819f02007-05-06 14:49:36 -07002220#endif
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002221 if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
2222 goto error;
Christoph Lameter81819f02007-05-06 14:49:36 -07002223
Christoph Lameterdfb4f092007-10-16 01:26:05 -07002224 if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA))
Christoph Lameter81819f02007-05-06 14:49:36 -07002225 return 1;
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002226 free_kmem_cache_nodes(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07002227error:
2228 if (flags & SLAB_PANIC)
2229 panic("Cannot create slab %s size=%lu realsize=%u "
2230 "order=%u offset=%u flags=%lx\n",
2231 s->name, (unsigned long)size, s->size, s->order,
2232 s->offset, flags);
2233 return 0;
2234}
Christoph Lameter81819f02007-05-06 14:49:36 -07002235
2236/*
2237 * Check if a given pointer is valid
2238 */
2239int kmem_ptr_validate(struct kmem_cache *s, const void *object)
2240{
Pekka Enberg06428782008-01-07 23:20:27 -08002241 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002242
2243 page = get_object_page(object);
2244
2245 if (!page || s != page->slab)
2246 /* No slab or wrong slab */
2247 return 0;
2248
Christoph Lameterabcd08a2007-05-09 02:32:37 -07002249 if (!check_valid_pointer(s, page, object))
Christoph Lameter81819f02007-05-06 14:49:36 -07002250 return 0;
2251
2252 /*
2253 * We could also check if the object is on the slabs freelist.
2254 * But this would be too expensive and it seems that the main
2255 * purpose of kmem_ptr_valid is to check if the object belongs
2256 * to a certain slab.
2257 */
2258 return 1;
2259}
2260EXPORT_SYMBOL(kmem_ptr_validate);
2261
2262/*
2263 * Determine the size of a slab object
2264 */
2265unsigned int kmem_cache_size(struct kmem_cache *s)
2266{
2267 return s->objsize;
2268}
2269EXPORT_SYMBOL(kmem_cache_size);
2270
2271const char *kmem_cache_name(struct kmem_cache *s)
2272{
2273 return s->name;
2274}
2275EXPORT_SYMBOL(kmem_cache_name);
2276
2277/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002278 * Attempt to free all slabs on a node. Return the number of slabs we
2279 * were unable to free.
Christoph Lameter81819f02007-05-06 14:49:36 -07002280 */
2281static int free_list(struct kmem_cache *s, struct kmem_cache_node *n,
2282 struct list_head *list)
2283{
2284 int slabs_inuse = 0;
2285 unsigned long flags;
2286 struct page *page, *h;
2287
2288 spin_lock_irqsave(&n->list_lock, flags);
2289 list_for_each_entry_safe(page, h, list, lru)
2290 if (!page->inuse) {
2291 list_del(&page->lru);
2292 discard_slab(s, page);
2293 } else
2294 slabs_inuse++;
2295 spin_unlock_irqrestore(&n->list_lock, flags);
2296 return slabs_inuse;
2297}
2298
2299/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002300 * Release all resources used by a slab cache.
Christoph Lameter81819f02007-05-06 14:49:36 -07002301 */
Christoph Lameter0c710012007-07-17 04:03:24 -07002302static inline int kmem_cache_close(struct kmem_cache *s)
Christoph Lameter81819f02007-05-06 14:49:36 -07002303{
2304 int node;
2305
2306 flush_all(s);
2307
2308 /* Attempt to free all objects */
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002309 free_kmem_cache_cpus(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002310 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002311 struct kmem_cache_node *n = get_node(s, node);
2312
Christoph Lameter2086d262007-05-06 14:49:46 -07002313 n->nr_partial -= free_list(s, n, &n->partial);
Christoph Lameter81819f02007-05-06 14:49:36 -07002314 if (atomic_long_read(&n->nr_slabs))
2315 return 1;
2316 }
2317 free_kmem_cache_nodes(s);
2318 return 0;
2319}
2320
2321/*
2322 * Close a cache and release the kmem_cache structure
2323 * (must be used for caches created using kmem_cache_create)
2324 */
2325void kmem_cache_destroy(struct kmem_cache *s)
2326{
2327 down_write(&slub_lock);
2328 s->refcount--;
2329 if (!s->refcount) {
2330 list_del(&s->list);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002331 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07002332 if (kmem_cache_close(s))
2333 WARN_ON(1);
2334 sysfs_slab_remove(s);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002335 } else
2336 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07002337}
2338EXPORT_SYMBOL(kmem_cache_destroy);
2339
2340/********************************************************************
2341 * Kmalloc subsystem
2342 *******************************************************************/
2343
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002344struct kmem_cache kmalloc_caches[PAGE_SHIFT] __cacheline_aligned;
Christoph Lameter81819f02007-05-06 14:49:36 -07002345EXPORT_SYMBOL(kmalloc_caches);
2346
2347#ifdef CONFIG_ZONE_DMA
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002348static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT];
Christoph Lameter81819f02007-05-06 14:49:36 -07002349#endif
2350
2351static int __init setup_slub_min_order(char *str)
2352{
Pekka Enberg06428782008-01-07 23:20:27 -08002353 get_option(&str, &slub_min_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002354
2355 return 1;
2356}
2357
2358__setup("slub_min_order=", setup_slub_min_order);
2359
2360static int __init setup_slub_max_order(char *str)
2361{
Pekka Enberg06428782008-01-07 23:20:27 -08002362 get_option(&str, &slub_max_order);
Christoph Lameter81819f02007-05-06 14:49:36 -07002363
2364 return 1;
2365}
2366
2367__setup("slub_max_order=", setup_slub_max_order);
2368
2369static int __init setup_slub_min_objects(char *str)
2370{
Pekka Enberg06428782008-01-07 23:20:27 -08002371 get_option(&str, &slub_min_objects);
Christoph Lameter81819f02007-05-06 14:49:36 -07002372
2373 return 1;
2374}
2375
2376__setup("slub_min_objects=", setup_slub_min_objects);
2377
2378static int __init setup_slub_nomerge(char *str)
2379{
2380 slub_nomerge = 1;
2381 return 1;
2382}
2383
2384__setup("slub_nomerge", setup_slub_nomerge);
2385
Christoph Lameter81819f02007-05-06 14:49:36 -07002386static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
2387 const char *name, int size, gfp_t gfp_flags)
2388{
2389 unsigned int flags = 0;
2390
2391 if (gfp_flags & SLUB_DMA)
2392 flags = SLAB_CACHE_DMA;
2393
2394 down_write(&slub_lock);
2395 if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002396 flags, NULL))
Christoph Lameter81819f02007-05-06 14:49:36 -07002397 goto panic;
2398
2399 list_add(&s->list, &slab_caches);
2400 up_write(&slub_lock);
2401 if (sysfs_slab_add(s))
2402 goto panic;
2403 return s;
2404
2405panic:
2406 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2407}
2408
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002409#ifdef CONFIG_ZONE_DMA
Christoph Lameter1ceef402007-08-07 15:11:48 -07002410
2411static void sysfs_add_func(struct work_struct *w)
2412{
2413 struct kmem_cache *s;
2414
2415 down_write(&slub_lock);
2416 list_for_each_entry(s, &slab_caches, list) {
2417 if (s->flags & __SYSFS_ADD_DEFERRED) {
2418 s->flags &= ~__SYSFS_ADD_DEFERRED;
2419 sysfs_slab_add(s);
2420 }
2421 }
2422 up_write(&slub_lock);
2423}
2424
2425static DECLARE_WORK(sysfs_add_work, sysfs_add_func);
2426
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002427static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
2428{
2429 struct kmem_cache *s;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002430 char *text;
2431 size_t realsize;
2432
2433 s = kmalloc_caches_dma[index];
2434 if (s)
2435 return s;
2436
2437 /* Dynamically create dma cache */
Christoph Lameter1ceef402007-08-07 15:11:48 -07002438 if (flags & __GFP_WAIT)
2439 down_write(&slub_lock);
2440 else {
2441 if (!down_write_trylock(&slub_lock))
2442 goto out;
2443 }
2444
2445 if (kmalloc_caches_dma[index])
2446 goto unlock_out;
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002447
Christoph Lameter7b55f622007-07-17 04:03:27 -07002448 realsize = kmalloc_caches[index].objsize;
Christoph Lameter1ceef402007-08-07 15:11:48 -07002449 text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d", (unsigned int)realsize),
2450 s = kmalloc(kmem_size, flags & ~SLUB_DMA);
2451
2452 if (!s || !text || !kmem_cache_open(s, flags, text,
2453 realsize, ARCH_KMALLOC_MINALIGN,
2454 SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) {
2455 kfree(s);
2456 kfree(text);
2457 goto unlock_out;
Christoph Lameterdfce8642007-07-17 04:03:25 -07002458 }
Christoph Lameter1ceef402007-08-07 15:11:48 -07002459
2460 list_add(&s->list, &slab_caches);
2461 kmalloc_caches_dma[index] = s;
2462
2463 schedule_work(&sysfs_add_work);
2464
2465unlock_out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002466 up_write(&slub_lock);
Christoph Lameter1ceef402007-08-07 15:11:48 -07002467out:
Christoph Lameterdfce8642007-07-17 04:03:25 -07002468 return kmalloc_caches_dma[index];
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002469}
2470#endif
2471
Christoph Lameterf1b26332007-07-17 04:03:26 -07002472/*
2473 * Conversion table for small slabs sizes / 8 to the index in the
2474 * kmalloc array. This is necessary for slabs < 192 since we have non power
2475 * of two cache sizes there. The size of larger slabs can be determined using
2476 * fls.
2477 */
2478static s8 size_index[24] = {
2479 3, /* 8 */
2480 4, /* 16 */
2481 5, /* 24 */
2482 5, /* 32 */
2483 6, /* 40 */
2484 6, /* 48 */
2485 6, /* 56 */
2486 6, /* 64 */
2487 1, /* 72 */
2488 1, /* 80 */
2489 1, /* 88 */
2490 1, /* 96 */
2491 7, /* 104 */
2492 7, /* 112 */
2493 7, /* 120 */
2494 7, /* 128 */
2495 2, /* 136 */
2496 2, /* 144 */
2497 2, /* 152 */
2498 2, /* 160 */
2499 2, /* 168 */
2500 2, /* 176 */
2501 2, /* 184 */
2502 2 /* 192 */
2503};
2504
Christoph Lameter81819f02007-05-06 14:49:36 -07002505static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2506{
Christoph Lameterf1b26332007-07-17 04:03:26 -07002507 int index;
Christoph Lameter81819f02007-05-06 14:49:36 -07002508
Christoph Lameterf1b26332007-07-17 04:03:26 -07002509 if (size <= 192) {
2510 if (!size)
2511 return ZERO_SIZE_PTR;
Christoph Lameter81819f02007-05-06 14:49:36 -07002512
Christoph Lameterf1b26332007-07-17 04:03:26 -07002513 index = size_index[(size - 1) / 8];
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002514 } else
Christoph Lameterf1b26332007-07-17 04:03:26 -07002515 index = fls(size - 1);
Christoph Lameter81819f02007-05-06 14:49:36 -07002516
2517#ifdef CONFIG_ZONE_DMA
Christoph Lameterf1b26332007-07-17 04:03:26 -07002518 if (unlikely((flags & SLUB_DMA)))
Christoph Lameter2e443fd2007-07-17 04:03:24 -07002519 return dma_kmalloc_cache(index, flags);
Christoph Lameterf1b26332007-07-17 04:03:26 -07002520
Christoph Lameter81819f02007-05-06 14:49:36 -07002521#endif
2522 return &kmalloc_caches[index];
2523}
2524
2525void *__kmalloc(size_t size, gfp_t flags)
2526{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002527 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002528
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002529 if (unlikely(size > PAGE_SIZE / 2))
2530 return (void *)__get_free_pages(flags | __GFP_COMP,
2531 get_order(size));
2532
2533 s = get_slab(size, flags);
2534
2535 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002536 return s;
2537
Christoph Lameterce15fea2007-07-17 04:03:28 -07002538 return slab_alloc(s, flags, -1, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002539}
2540EXPORT_SYMBOL(__kmalloc);
2541
2542#ifdef CONFIG_NUMA
2543void *__kmalloc_node(size_t size, gfp_t flags, int node)
2544{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002545 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002546
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002547 if (unlikely(size > PAGE_SIZE / 2))
2548 return (void *)__get_free_pages(flags | __GFP_COMP,
2549 get_order(size));
2550
2551 s = get_slab(size, flags);
2552
2553 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07002554 return s;
2555
Christoph Lameterce15fea2007-07-17 04:03:28 -07002556 return slab_alloc(s, flags, node, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002557}
2558EXPORT_SYMBOL(__kmalloc_node);
2559#endif
2560
2561size_t ksize(const void *object)
2562{
Christoph Lameter272c1d22007-06-08 13:46:49 -07002563 struct page *page;
Christoph Lameter81819f02007-05-06 14:49:36 -07002564 struct kmem_cache *s;
2565
Christoph Lameteref8b4522007-10-16 01:24:46 -07002566 BUG_ON(!object);
2567 if (unlikely(object == ZERO_SIZE_PTR))
Christoph Lameter272c1d22007-06-08 13:46:49 -07002568 return 0;
2569
Vegard Nossum294a80a2007-12-04 23:45:30 -08002570 page = virt_to_head_page(object);
Christoph Lameter81819f02007-05-06 14:49:36 -07002571 BUG_ON(!page);
Vegard Nossum294a80a2007-12-04 23:45:30 -08002572
2573 if (unlikely(!PageSlab(page)))
2574 return PAGE_SIZE << compound_order(page);
2575
Christoph Lameter81819f02007-05-06 14:49:36 -07002576 s = page->slab;
2577 BUG_ON(!s);
2578
2579 /*
2580 * Debugging requires use of the padding between object
2581 * and whatever may come after it.
2582 */
2583 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
2584 return s->objsize;
2585
2586 /*
2587 * If we have the need to store the freelist pointer
2588 * back there or track user information then we can
2589 * only use the space before that information.
2590 */
2591 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
2592 return s->inuse;
2593
2594 /*
2595 * Else we can use all the padding etc for the allocation
2596 */
2597 return s->size;
2598}
2599EXPORT_SYMBOL(ksize);
2600
2601void kfree(const void *x)
2602{
Christoph Lameter81819f02007-05-06 14:49:36 -07002603 struct page *page;
2604
Satyam Sharma2408c552007-10-16 01:24:44 -07002605 if (unlikely(ZERO_OR_NULL_PTR(x)))
Christoph Lameter81819f02007-05-06 14:49:36 -07002606 return;
2607
Christoph Lameterb49af682007-05-06 14:49:41 -07002608 page = virt_to_head_page(x);
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002609 if (unlikely(!PageSlab(page))) {
2610 put_page(page);
2611 return;
2612 }
2613 slab_free(page->slab, page, (void *)x, __builtin_return_address(0));
Christoph Lameter81819f02007-05-06 14:49:36 -07002614}
2615EXPORT_SYMBOL(kfree);
2616
Christoph Lameterf61396a2008-01-07 23:20:26 -08002617static unsigned long count_partial(struct kmem_cache_node *n)
2618{
2619 unsigned long flags;
2620 unsigned long x = 0;
2621 struct page *page;
2622
2623 spin_lock_irqsave(&n->list_lock, flags);
2624 list_for_each_entry(page, &n->partial, lru)
2625 x += page->inuse;
2626 spin_unlock_irqrestore(&n->list_lock, flags);
2627 return x;
2628}
2629
Christoph Lameter2086d262007-05-06 14:49:46 -07002630/*
Christoph Lameter672bba32007-05-09 02:32:39 -07002631 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2632 * the remaining slabs by the number of items in use. The slabs with the
2633 * most items in use come first. New allocations will then fill those up
2634 * and thus they can be removed from the partial lists.
2635 *
2636 * The slabs with the least items are placed last. This results in them
2637 * being allocated from last increasing the chance that the last objects
2638 * are freed in them.
Christoph Lameter2086d262007-05-06 14:49:46 -07002639 */
2640int kmem_cache_shrink(struct kmem_cache *s)
2641{
2642 int node;
2643 int i;
2644 struct kmem_cache_node *n;
2645 struct page *page;
2646 struct page *t;
2647 struct list_head *slabs_by_inuse =
2648 kmalloc(sizeof(struct list_head) * s->objects, GFP_KERNEL);
2649 unsigned long flags;
2650
2651 if (!slabs_by_inuse)
2652 return -ENOMEM;
2653
2654 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07002655 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter2086d262007-05-06 14:49:46 -07002656 n = get_node(s, node);
2657
2658 if (!n->nr_partial)
2659 continue;
2660
2661 for (i = 0; i < s->objects; i++)
2662 INIT_LIST_HEAD(slabs_by_inuse + i);
2663
2664 spin_lock_irqsave(&n->list_lock, flags);
2665
2666 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002667 * Build lists indexed by the items in use in each slab.
Christoph Lameter2086d262007-05-06 14:49:46 -07002668 *
Christoph Lameter672bba32007-05-09 02:32:39 -07002669 * Note that concurrent frees may occur while we hold the
2670 * list_lock. page->inuse here is the upper limit.
Christoph Lameter2086d262007-05-06 14:49:46 -07002671 */
2672 list_for_each_entry_safe(page, t, &n->partial, lru) {
2673 if (!page->inuse && slab_trylock(page)) {
2674 /*
2675 * Must hold slab lock here because slab_free
2676 * may have freed the last object and be
2677 * waiting to release the slab.
2678 */
2679 list_del(&page->lru);
2680 n->nr_partial--;
2681 slab_unlock(page);
2682 discard_slab(s, page);
2683 } else {
Christoph Lameterfcda3d82007-07-30 13:06:46 -07002684 list_move(&page->lru,
2685 slabs_by_inuse + page->inuse);
Christoph Lameter2086d262007-05-06 14:49:46 -07002686 }
2687 }
2688
Christoph Lameter2086d262007-05-06 14:49:46 -07002689 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07002690 * Rebuild the partial list with the slabs filled up most
2691 * first and the least used slabs at the end.
Christoph Lameter2086d262007-05-06 14:49:46 -07002692 */
2693 for (i = s->objects - 1; i >= 0; i--)
2694 list_splice(slabs_by_inuse + i, n->partial.prev);
2695
Christoph Lameter2086d262007-05-06 14:49:46 -07002696 spin_unlock_irqrestore(&n->list_lock, flags);
2697 }
2698
2699 kfree(slabs_by_inuse);
2700 return 0;
2701}
2702EXPORT_SYMBOL(kmem_cache_shrink);
2703
Yasunori Gotob9049e22007-10-21 16:41:37 -07002704#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2705static int slab_mem_going_offline_callback(void *arg)
2706{
2707 struct kmem_cache *s;
2708
2709 down_read(&slub_lock);
2710 list_for_each_entry(s, &slab_caches, list)
2711 kmem_cache_shrink(s);
2712 up_read(&slub_lock);
2713
2714 return 0;
2715}
2716
2717static void slab_mem_offline_callback(void *arg)
2718{
2719 struct kmem_cache_node *n;
2720 struct kmem_cache *s;
2721 struct memory_notify *marg = arg;
2722 int offline_node;
2723
2724 offline_node = marg->status_change_nid;
2725
2726 /*
2727 * If the node still has available memory. we need kmem_cache_node
2728 * for it yet.
2729 */
2730 if (offline_node < 0)
2731 return;
2732
2733 down_read(&slub_lock);
2734 list_for_each_entry(s, &slab_caches, list) {
2735 n = get_node(s, offline_node);
2736 if (n) {
2737 /*
2738 * if n->nr_slabs > 0, slabs still exist on the node
2739 * that is going down. We were unable to free them,
2740 * and offline_pages() function shoudn't call this
2741 * callback. So, we must fail.
2742 */
Al Viro27bb6282007-10-29 04:42:55 +00002743 BUG_ON(atomic_long_read(&n->nr_slabs));
Yasunori Gotob9049e22007-10-21 16:41:37 -07002744
2745 s->node[offline_node] = NULL;
2746 kmem_cache_free(kmalloc_caches, n);
2747 }
2748 }
2749 up_read(&slub_lock);
2750}
2751
2752static int slab_mem_going_online_callback(void *arg)
2753{
2754 struct kmem_cache_node *n;
2755 struct kmem_cache *s;
2756 struct memory_notify *marg = arg;
2757 int nid = marg->status_change_nid;
2758 int ret = 0;
2759
2760 /*
2761 * If the node's memory is already available, then kmem_cache_node is
2762 * already created. Nothing to do.
2763 */
2764 if (nid < 0)
2765 return 0;
2766
2767 /*
2768 * We are bringing a node online. No memory is availabe yet. We must
2769 * allocate a kmem_cache_node structure in order to bring the node
2770 * online.
2771 */
2772 down_read(&slub_lock);
2773 list_for_each_entry(s, &slab_caches, list) {
2774 /*
2775 * XXX: kmem_cache_alloc_node will fallback to other nodes
2776 * since memory is not yet available from the node that
2777 * is brought up.
2778 */
2779 n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL);
2780 if (!n) {
2781 ret = -ENOMEM;
2782 goto out;
2783 }
2784 init_kmem_cache_node(n);
2785 s->node[nid] = n;
2786 }
2787out:
2788 up_read(&slub_lock);
2789 return ret;
2790}
2791
2792static int slab_memory_callback(struct notifier_block *self,
2793 unsigned long action, void *arg)
2794{
2795 int ret = 0;
2796
2797 switch (action) {
2798 case MEM_GOING_ONLINE:
2799 ret = slab_mem_going_online_callback(arg);
2800 break;
2801 case MEM_GOING_OFFLINE:
2802 ret = slab_mem_going_offline_callback(arg);
2803 break;
2804 case MEM_OFFLINE:
2805 case MEM_CANCEL_ONLINE:
2806 slab_mem_offline_callback(arg);
2807 break;
2808 case MEM_ONLINE:
2809 case MEM_CANCEL_OFFLINE:
2810 break;
2811 }
2812
2813 ret = notifier_from_errno(ret);
2814 return ret;
2815}
2816
2817#endif /* CONFIG_MEMORY_HOTPLUG */
2818
Christoph Lameter81819f02007-05-06 14:49:36 -07002819/********************************************************************
2820 * Basic setup of slabs
2821 *******************************************************************/
2822
2823void __init kmem_cache_init(void)
2824{
2825 int i;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002826 int caches = 0;
Christoph Lameter81819f02007-05-06 14:49:36 -07002827
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002828 init_alloc_cpu();
2829
Christoph Lameter81819f02007-05-06 14:49:36 -07002830#ifdef CONFIG_NUMA
2831 /*
2832 * Must first have the slab cache available for the allocations of the
Christoph Lameter672bba32007-05-09 02:32:39 -07002833 * struct kmem_cache_node's. There is special bootstrap code in
Christoph Lameter81819f02007-05-06 14:49:36 -07002834 * kmem_cache_open for slab_state == DOWN.
2835 */
2836 create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
2837 sizeof(struct kmem_cache_node), GFP_KERNEL);
Christoph Lameter8ffa6872007-05-31 00:40:51 -07002838 kmalloc_caches[0].refcount = -1;
Christoph Lameter4b356be2007-06-16 10:16:13 -07002839 caches++;
Yasunori Gotob9049e22007-10-21 16:41:37 -07002840
2841 hotplug_memory_notifier(slab_memory_callback, 1);
Christoph Lameter81819f02007-05-06 14:49:36 -07002842#endif
2843
2844 /* Able to allocate the per node structures */
2845 slab_state = PARTIAL;
2846
2847 /* Caches that are not of the two-to-the-power-of size */
Christoph Lameter4b356be2007-06-16 10:16:13 -07002848 if (KMALLOC_MIN_SIZE <= 64) {
2849 create_kmalloc_cache(&kmalloc_caches[1],
Christoph Lameter81819f02007-05-06 14:49:36 -07002850 "kmalloc-96", 96, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002851 caches++;
2852 }
2853 if (KMALLOC_MIN_SIZE <= 128) {
2854 create_kmalloc_cache(&kmalloc_caches[2],
Christoph Lameter81819f02007-05-06 14:49:36 -07002855 "kmalloc-192", 192, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002856 caches++;
2857 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002858
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002859 for (i = KMALLOC_SHIFT_LOW; i < PAGE_SHIFT; i++) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002860 create_kmalloc_cache(&kmalloc_caches[i],
2861 "kmalloc", 1 << i, GFP_KERNEL);
Christoph Lameter4b356be2007-06-16 10:16:13 -07002862 caches++;
2863 }
Christoph Lameter81819f02007-05-06 14:49:36 -07002864
Christoph Lameterf1b26332007-07-17 04:03:26 -07002865
2866 /*
2867 * Patch up the size_index table if we have strange large alignment
2868 * requirements for the kmalloc array. This is only the case for
2869 * mips it seems. The standard arches will not generate any code here.
2870 *
2871 * Largest permitted alignment is 256 bytes due to the way we
2872 * handle the index determination for the smaller caches.
2873 *
2874 * Make sure that nothing crazy happens if someone starts tinkering
2875 * around with ARCH_KMALLOC_MINALIGN
2876 */
2877 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
2878 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
2879
Christoph Lameter12ad6842007-07-17 04:03:28 -07002880 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
Christoph Lameterf1b26332007-07-17 04:03:26 -07002881 size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
2882
Christoph Lameter81819f02007-05-06 14:49:36 -07002883 slab_state = UP;
2884
2885 /* Provide the correct kmalloc names now that the caches are up */
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07002886 for (i = KMALLOC_SHIFT_LOW; i < PAGE_SHIFT; i++)
Christoph Lameter81819f02007-05-06 14:49:36 -07002887 kmalloc_caches[i]. name =
2888 kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
2889
2890#ifdef CONFIG_SMP
2891 register_cpu_notifier(&slab_notifier);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07002892 kmem_size = offsetof(struct kmem_cache, cpu_slab) +
2893 nr_cpu_ids * sizeof(struct kmem_cache_cpu *);
2894#else
2895 kmem_size = sizeof(struct kmem_cache);
Christoph Lameter81819f02007-05-06 14:49:36 -07002896#endif
2897
Christoph Lameter81819f02007-05-06 14:49:36 -07002898
2899 printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
Christoph Lameter4b356be2007-06-16 10:16:13 -07002900 " CPUs=%d, Nodes=%d\n",
2901 caches, cache_line_size(),
Christoph Lameter81819f02007-05-06 14:49:36 -07002902 slub_min_order, slub_max_order, slub_min_objects,
2903 nr_cpu_ids, nr_node_ids);
2904}
2905
2906/*
2907 * Find a mergeable slab cache
2908 */
2909static int slab_unmergeable(struct kmem_cache *s)
2910{
2911 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
2912 return 1;
2913
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002914 if (s->ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07002915 return 1;
2916
Christoph Lameter8ffa6872007-05-31 00:40:51 -07002917 /*
2918 * We may have set a slab to be unmergeable during bootstrap.
2919 */
2920 if (s->refcount < 0)
2921 return 1;
2922
Christoph Lameter81819f02007-05-06 14:49:36 -07002923 return 0;
2924}
2925
2926static struct kmem_cache *find_mergeable(size_t size,
Christoph Lameterba0268a2007-09-11 15:24:11 -07002927 size_t align, unsigned long flags, const char *name,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07002928 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07002929{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07002930 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07002931
2932 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
2933 return NULL;
2934
Christoph Lameterc59def9f2007-05-16 22:10:50 -07002935 if (ctor)
Christoph Lameter81819f02007-05-06 14:49:36 -07002936 return NULL;
2937
2938 size = ALIGN(size, sizeof(void *));
2939 align = calculate_alignment(flags, align, size);
2940 size = ALIGN(size, align);
Christoph Lameterba0268a2007-09-11 15:24:11 -07002941 flags = kmem_cache_flags(size, flags, name, NULL);
Christoph Lameter81819f02007-05-06 14:49:36 -07002942
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07002943 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter81819f02007-05-06 14:49:36 -07002944 if (slab_unmergeable(s))
2945 continue;
2946
2947 if (size > s->size)
2948 continue;
2949
Christoph Lameterba0268a2007-09-11 15:24:11 -07002950 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
Christoph Lameter81819f02007-05-06 14:49:36 -07002951 continue;
2952 /*
2953 * Check if alignment is compatible.
2954 * Courtesy of Adrian Drzewiecki
2955 */
Pekka Enberg06428782008-01-07 23:20:27 -08002956 if ((s->size & ~(align - 1)) != s->size)
Christoph Lameter81819f02007-05-06 14:49:36 -07002957 continue;
2958
2959 if (s->size - size >= sizeof(void *))
2960 continue;
2961
2962 return s;
2963 }
2964 return NULL;
2965}
2966
2967struct kmem_cache *kmem_cache_create(const char *name, size_t size,
2968 size_t align, unsigned long flags,
Christoph Lameter4ba9b9d2007-10-16 23:25:51 -07002969 void (*ctor)(struct kmem_cache *, void *))
Christoph Lameter81819f02007-05-06 14:49:36 -07002970{
2971 struct kmem_cache *s;
2972
2973 down_write(&slub_lock);
Christoph Lameterba0268a2007-09-11 15:24:11 -07002974 s = find_mergeable(size, align, flags, name, ctor);
Christoph Lameter81819f02007-05-06 14:49:36 -07002975 if (s) {
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07002976 int cpu;
2977
Christoph Lameter81819f02007-05-06 14:49:36 -07002978 s->refcount++;
2979 /*
2980 * Adjust the object sizes so that we clear
2981 * the complete object on kzalloc.
2982 */
2983 s->objsize = max(s->objsize, (int)size);
Christoph Lameter42a9fdb2007-10-16 01:26:09 -07002984
2985 /*
2986 * And then we need to update the object size in the
2987 * per cpu structures
2988 */
2989 for_each_online_cpu(cpu)
2990 get_cpu_slab(s, cpu)->objsize = s->objsize;
Christoph Lameter81819f02007-05-06 14:49:36 -07002991 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002992 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07002993 if (sysfs_slab_alias(s, name))
2994 goto err;
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07002995 return s;
2996 }
2997 s = kmalloc(kmem_size, GFP_KERNEL);
2998 if (s) {
2999 if (kmem_cache_open(s, GFP_KERNEL, name,
Christoph Lameterc59def9f2007-05-16 22:10:50 -07003000 size, align, flags, ctor)) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003001 list_add(&s->list, &slab_caches);
Christoph Lametera0e1d1b2007-07-17 04:03:31 -07003002 up_write(&slub_lock);
3003 if (sysfs_slab_add(s))
3004 goto err;
3005 return s;
3006 }
3007 kfree(s);
Christoph Lameter81819f02007-05-06 14:49:36 -07003008 }
3009 up_write(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003010
3011err:
Christoph Lameter81819f02007-05-06 14:49:36 -07003012 if (flags & SLAB_PANIC)
3013 panic("Cannot create slabcache %s\n", name);
3014 else
3015 s = NULL;
3016 return s;
3017}
3018EXPORT_SYMBOL(kmem_cache_create);
3019
Christoph Lameter81819f02007-05-06 14:49:36 -07003020#ifdef CONFIG_SMP
Christoph Lameter27390bc2007-06-01 00:47:09 -07003021/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003022 * Use the cpu notifier to insure that the cpu slabs are flushed when
3023 * necessary.
Christoph Lameter81819f02007-05-06 14:49:36 -07003024 */
3025static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3026 unsigned long action, void *hcpu)
3027{
3028 long cpu = (long)hcpu;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003029 struct kmem_cache *s;
3030 unsigned long flags;
Christoph Lameter81819f02007-05-06 14:49:36 -07003031
3032 switch (action) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003033 case CPU_UP_PREPARE:
3034 case CPU_UP_PREPARE_FROZEN:
3035 init_alloc_cpu_cpu(cpu);
3036 down_read(&slub_lock);
3037 list_for_each_entry(s, &slab_caches, list)
3038 s->cpu_slab[cpu] = alloc_kmem_cache_cpu(s, cpu,
3039 GFP_KERNEL);
3040 up_read(&slub_lock);
3041 break;
3042
Christoph Lameter81819f02007-05-06 14:49:36 -07003043 case CPU_UP_CANCELED:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003044 case CPU_UP_CANCELED_FROZEN:
Christoph Lameter81819f02007-05-06 14:49:36 -07003045 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07003046 case CPU_DEAD_FROZEN:
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003047 down_read(&slub_lock);
3048 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003049 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
3050
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003051 local_irq_save(flags);
3052 __flush_cpu_slab(s, cpu);
3053 local_irq_restore(flags);
Christoph Lameter4c93c3552007-10-16 01:26:08 -07003054 free_kmem_cache_cpu(c, cpu);
3055 s->cpu_slab[cpu] = NULL;
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07003056 }
3057 up_read(&slub_lock);
Christoph Lameter81819f02007-05-06 14:49:36 -07003058 break;
3059 default:
3060 break;
3061 }
3062 return NOTIFY_OK;
3063}
3064
Pekka Enberg06428782008-01-07 23:20:27 -08003065static struct notifier_block __cpuinitdata slab_notifier = {
3066 &slab_cpuup_callback, NULL, 0
3067};
Christoph Lameter81819f02007-05-06 14:49:36 -07003068
3069#endif
3070
Christoph Lameter81819f02007-05-06 14:49:36 -07003071void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
3072{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003073 struct kmem_cache *s;
3074
3075 if (unlikely(size > PAGE_SIZE / 2))
3076 return (void *)__get_free_pages(gfpflags | __GFP_COMP,
3077 get_order(size));
3078 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003079
Satyam Sharma2408c552007-10-16 01:24:44 -07003080 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003081 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003082
Christoph Lameterce15fea2007-07-17 04:03:28 -07003083 return slab_alloc(s, gfpflags, -1, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003084}
3085
3086void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3087 int node, void *caller)
3088{
Christoph Lameteraadb4bc2007-10-16 01:24:38 -07003089 struct kmem_cache *s;
3090
3091 if (unlikely(size > PAGE_SIZE / 2))
3092 return (void *)__get_free_pages(gfpflags | __GFP_COMP,
3093 get_order(size));
3094 s = get_slab(size, gfpflags);
Christoph Lameter81819f02007-05-06 14:49:36 -07003095
Satyam Sharma2408c552007-10-16 01:24:44 -07003096 if (unlikely(ZERO_OR_NULL_PTR(s)))
Christoph Lameter6cb8f912007-07-17 04:03:22 -07003097 return s;
Christoph Lameter81819f02007-05-06 14:49:36 -07003098
Christoph Lameterce15fea2007-07-17 04:03:28 -07003099 return slab_alloc(s, gfpflags, node, caller);
Christoph Lameter81819f02007-05-06 14:49:36 -07003100}
3101
Christoph Lameter41ecc552007-05-09 02:32:44 -07003102#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
Christoph Lameter434e2452007-07-17 04:03:30 -07003103static int validate_slab(struct kmem_cache *s, struct page *page,
3104 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003105{
3106 void *p;
3107 void *addr = page_address(page);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003108
3109 if (!check_slab(s, page) ||
3110 !on_freelist(s, page, NULL))
3111 return 0;
3112
3113 /* Now we know that a valid freelist exists */
3114 bitmap_zero(map, s->objects);
3115
Christoph Lameter7656c722007-05-09 02:32:40 -07003116 for_each_free_object(p, s, page->freelist) {
3117 set_bit(slab_index(p, s, addr), map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003118 if (!check_object(s, page, p, 0))
3119 return 0;
3120 }
3121
Christoph Lameter7656c722007-05-09 02:32:40 -07003122 for_each_object(p, s, addr)
3123 if (!test_bit(slab_index(p, s, addr), map))
Christoph Lameter53e15af2007-05-06 14:49:43 -07003124 if (!check_object(s, page, p, 1))
3125 return 0;
3126 return 1;
3127}
3128
Christoph Lameter434e2452007-07-17 04:03:30 -07003129static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3130 unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003131{
3132 if (slab_trylock(page)) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003133 validate_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003134 slab_unlock(page);
3135 } else
3136 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3137 s->name, page);
3138
3139 if (s->flags & DEBUG_DEFAULT_FLAGS) {
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07003140 if (!SlabDebug(page))
3141 printk(KERN_ERR "SLUB %s: SlabDebug not set "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003142 "on slab 0x%p\n", s->name, page);
3143 } else {
Christoph Lameter35e5d7e2007-05-09 02:32:42 -07003144 if (SlabDebug(page))
3145 printk(KERN_ERR "SLUB %s: SlabDebug set on "
Christoph Lameter53e15af2007-05-06 14:49:43 -07003146 "slab 0x%p\n", s->name, page);
3147 }
3148}
3149
Christoph Lameter434e2452007-07-17 04:03:30 -07003150static int validate_slab_node(struct kmem_cache *s,
3151 struct kmem_cache_node *n, unsigned long *map)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003152{
3153 unsigned long count = 0;
3154 struct page *page;
3155 unsigned long flags;
3156
3157 spin_lock_irqsave(&n->list_lock, flags);
3158
3159 list_for_each_entry(page, &n->partial, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003160 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003161 count++;
3162 }
3163 if (count != n->nr_partial)
3164 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3165 "counter=%ld\n", s->name, count, n->nr_partial);
3166
3167 if (!(s->flags & SLAB_STORE_USER))
3168 goto out;
3169
3170 list_for_each_entry(page, &n->full, lru) {
Christoph Lameter434e2452007-07-17 04:03:30 -07003171 validate_slab_slab(s, page, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003172 count++;
3173 }
3174 if (count != atomic_long_read(&n->nr_slabs))
3175 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3176 "counter=%ld\n", s->name, count,
3177 atomic_long_read(&n->nr_slabs));
3178
3179out:
3180 spin_unlock_irqrestore(&n->list_lock, flags);
3181 return count;
3182}
3183
Christoph Lameter434e2452007-07-17 04:03:30 -07003184static long validate_slab_cache(struct kmem_cache *s)
Christoph Lameter53e15af2007-05-06 14:49:43 -07003185{
3186 int node;
3187 unsigned long count = 0;
Christoph Lameter434e2452007-07-17 04:03:30 -07003188 unsigned long *map = kmalloc(BITS_TO_LONGS(s->objects) *
3189 sizeof(unsigned long), GFP_KERNEL);
3190
3191 if (!map)
3192 return -ENOMEM;
Christoph Lameter53e15af2007-05-06 14:49:43 -07003193
3194 flush_all(s);
Christoph Lameterf64dc582007-10-16 01:25:33 -07003195 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter53e15af2007-05-06 14:49:43 -07003196 struct kmem_cache_node *n = get_node(s, node);
3197
Christoph Lameter434e2452007-07-17 04:03:30 -07003198 count += validate_slab_node(s, n, map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003199 }
Christoph Lameter434e2452007-07-17 04:03:30 -07003200 kfree(map);
Christoph Lameter53e15af2007-05-06 14:49:43 -07003201 return count;
3202}
3203
Christoph Lameterb3459702007-05-09 02:32:41 -07003204#ifdef SLUB_RESILIENCY_TEST
3205static void resiliency_test(void)
3206{
3207 u8 *p;
3208
3209 printk(KERN_ERR "SLUB resiliency testing\n");
3210 printk(KERN_ERR "-----------------------\n");
3211 printk(KERN_ERR "A. Corruption after allocation\n");
3212
3213 p = kzalloc(16, GFP_KERNEL);
3214 p[16] = 0x12;
3215 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3216 " 0x12->0x%p\n\n", p + 16);
3217
3218 validate_slab_cache(kmalloc_caches + 4);
3219
3220 /* Hmmm... The next two are dangerous */
3221 p = kzalloc(32, GFP_KERNEL);
3222 p[32 + sizeof(void *)] = 0x34;
3223 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
3224 " 0x34 -> -0x%p\n", p);
3225 printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n");
3226
3227 validate_slab_cache(kmalloc_caches + 5);
3228 p = kzalloc(64, GFP_KERNEL);
3229 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3230 *p = 0x56;
3231 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3232 p);
3233 printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n");
3234 validate_slab_cache(kmalloc_caches + 6);
3235
3236 printk(KERN_ERR "\nB. Corruption after free\n");
3237 p = kzalloc(128, GFP_KERNEL);
3238 kfree(p);
3239 *p = 0x78;
3240 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3241 validate_slab_cache(kmalloc_caches + 7);
3242
3243 p = kzalloc(256, GFP_KERNEL);
3244 kfree(p);
3245 p[50] = 0x9a;
3246 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", p);
3247 validate_slab_cache(kmalloc_caches + 8);
3248
3249 p = kzalloc(512, GFP_KERNEL);
3250 kfree(p);
3251 p[512] = 0xab;
3252 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3253 validate_slab_cache(kmalloc_caches + 9);
3254}
3255#else
3256static void resiliency_test(void) {};
3257#endif
3258
Christoph Lameter88a420e2007-05-06 14:49:45 -07003259/*
Christoph Lameter672bba32007-05-09 02:32:39 -07003260 * Generate lists of code addresses where slabcache objects are allocated
Christoph Lameter88a420e2007-05-06 14:49:45 -07003261 * and freed.
3262 */
3263
3264struct location {
3265 unsigned long count;
3266 void *addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003267 long long sum_time;
3268 long min_time;
3269 long max_time;
3270 long min_pid;
3271 long max_pid;
3272 cpumask_t cpus;
3273 nodemask_t nodes;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003274};
3275
3276struct loc_track {
3277 unsigned long max;
3278 unsigned long count;
3279 struct location *loc;
3280};
3281
3282static void free_loc_track(struct loc_track *t)
3283{
3284 if (t->max)
3285 free_pages((unsigned long)t->loc,
3286 get_order(sizeof(struct location) * t->max));
3287}
3288
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003289static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003290{
3291 struct location *l;
3292 int order;
3293
Christoph Lameter88a420e2007-05-06 14:49:45 -07003294 order = get_order(sizeof(struct location) * max);
3295
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003296 l = (void *)__get_free_pages(flags, order);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003297 if (!l)
3298 return 0;
3299
3300 if (t->count) {
3301 memcpy(l, t->loc, sizeof(struct location) * t->count);
3302 free_loc_track(t);
3303 }
3304 t->max = max;
3305 t->loc = l;
3306 return 1;
3307}
3308
3309static int add_location(struct loc_track *t, struct kmem_cache *s,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003310 const struct track *track)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003311{
3312 long start, end, pos;
3313 struct location *l;
3314 void *caddr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003315 unsigned long age = jiffies - track->when;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003316
3317 start = -1;
3318 end = t->count;
3319
3320 for ( ; ; ) {
3321 pos = start + (end - start + 1) / 2;
3322
3323 /*
3324 * There is nothing at "end". If we end up there
3325 * we need to add something to before end.
3326 */
3327 if (pos == end)
3328 break;
3329
3330 caddr = t->loc[pos].addr;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003331 if (track->addr == caddr) {
3332
3333 l = &t->loc[pos];
3334 l->count++;
3335 if (track->when) {
3336 l->sum_time += age;
3337 if (age < l->min_time)
3338 l->min_time = age;
3339 if (age > l->max_time)
3340 l->max_time = age;
3341
3342 if (track->pid < l->min_pid)
3343 l->min_pid = track->pid;
3344 if (track->pid > l->max_pid)
3345 l->max_pid = track->pid;
3346
3347 cpu_set(track->cpu, l->cpus);
3348 }
3349 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003350 return 1;
3351 }
3352
Christoph Lameter45edfa52007-05-09 02:32:45 -07003353 if (track->addr < caddr)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003354 end = pos;
3355 else
3356 start = pos;
3357 }
3358
3359 /*
Christoph Lameter672bba32007-05-09 02:32:39 -07003360 * Not found. Insert new tracking element.
Christoph Lameter88a420e2007-05-06 14:49:45 -07003361 */
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003362 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003363 return 0;
3364
3365 l = t->loc + pos;
3366 if (pos < t->count)
3367 memmove(l + 1, l,
3368 (t->count - pos) * sizeof(struct location));
3369 t->count++;
3370 l->count = 1;
Christoph Lameter45edfa52007-05-09 02:32:45 -07003371 l->addr = track->addr;
3372 l->sum_time = age;
3373 l->min_time = age;
3374 l->max_time = age;
3375 l->min_pid = track->pid;
3376 l->max_pid = track->pid;
3377 cpus_clear(l->cpus);
3378 cpu_set(track->cpu, l->cpus);
3379 nodes_clear(l->nodes);
3380 node_set(page_to_nid(virt_to_page(track)), l->nodes);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003381 return 1;
3382}
3383
3384static void process_slab(struct loc_track *t, struct kmem_cache *s,
3385 struct page *page, enum track_item alloc)
3386{
3387 void *addr = page_address(page);
Christoph Lameter7656c722007-05-09 02:32:40 -07003388 DECLARE_BITMAP(map, s->objects);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003389 void *p;
3390
3391 bitmap_zero(map, s->objects);
Christoph Lameter7656c722007-05-09 02:32:40 -07003392 for_each_free_object(p, s, page->freelist)
3393 set_bit(slab_index(p, s, addr), map);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003394
Christoph Lameter7656c722007-05-09 02:32:40 -07003395 for_each_object(p, s, addr)
Christoph Lameter45edfa52007-05-09 02:32:45 -07003396 if (!test_bit(slab_index(p, s, addr), map))
3397 add_location(t, s, get_track(s, p, alloc));
Christoph Lameter88a420e2007-05-06 14:49:45 -07003398}
3399
3400static int list_locations(struct kmem_cache *s, char *buf,
3401 enum track_item alloc)
3402{
Harvey Harrisone374d482008-01-31 15:20:50 -08003403 int len = 0;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003404 unsigned long i;
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003405 struct loc_track t = { 0, 0, NULL };
Christoph Lameter88a420e2007-05-06 14:49:45 -07003406 int node;
3407
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003408 if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
Andrew Mortonea3061d2007-10-16 01:26:09 -07003409 GFP_TEMPORARY))
Christoph Lameter68dff6a2007-07-17 04:03:20 -07003410 return sprintf(buf, "Out of memory\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003411
3412 /* Push back cpu slabs */
3413 flush_all(s);
3414
Christoph Lameterf64dc582007-10-16 01:25:33 -07003415 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter88a420e2007-05-06 14:49:45 -07003416 struct kmem_cache_node *n = get_node(s, node);
3417 unsigned long flags;
3418 struct page *page;
3419
Christoph Lameter9e869432007-08-22 14:01:56 -07003420 if (!atomic_long_read(&n->nr_slabs))
Christoph Lameter88a420e2007-05-06 14:49:45 -07003421 continue;
3422
3423 spin_lock_irqsave(&n->list_lock, flags);
3424 list_for_each_entry(page, &n->partial, lru)
3425 process_slab(&t, s, page, alloc);
3426 list_for_each_entry(page, &n->full, lru)
3427 process_slab(&t, s, page, alloc);
3428 spin_unlock_irqrestore(&n->list_lock, flags);
3429 }
3430
3431 for (i = 0; i < t.count; i++) {
Christoph Lameter45edfa52007-05-09 02:32:45 -07003432 struct location *l = &t.loc[i];
Christoph Lameter88a420e2007-05-06 14:49:45 -07003433
Harvey Harrisone374d482008-01-31 15:20:50 -08003434 if (len > PAGE_SIZE - 100)
Christoph Lameter88a420e2007-05-06 14:49:45 -07003435 break;
Harvey Harrisone374d482008-01-31 15:20:50 -08003436 len += sprintf(buf + len, "%7ld ", l->count);
Christoph Lameter45edfa52007-05-09 02:32:45 -07003437
3438 if (l->addr)
Harvey Harrisone374d482008-01-31 15:20:50 -08003439 len += sprint_symbol(buf + len, (unsigned long)l->addr);
Christoph Lameter88a420e2007-05-06 14:49:45 -07003440 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003441 len += sprintf(buf + len, "<not-available>");
Christoph Lameter45edfa52007-05-09 02:32:45 -07003442
3443 if (l->sum_time != l->min_time) {
3444 unsigned long remainder;
3445
Harvey Harrisone374d482008-01-31 15:20:50 -08003446 len += sprintf(buf + len, " age=%ld/%ld/%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003447 l->min_time,
3448 div_long_long_rem(l->sum_time, l->count, &remainder),
3449 l->max_time);
3450 } else
Harvey Harrisone374d482008-01-31 15:20:50 -08003451 len += sprintf(buf + len, " age=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003452 l->min_time);
3453
3454 if (l->min_pid != l->max_pid)
Harvey Harrisone374d482008-01-31 15:20:50 -08003455 len += sprintf(buf + len, " pid=%ld-%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003456 l->min_pid, l->max_pid);
3457 else
Harvey Harrisone374d482008-01-31 15:20:50 -08003458 len += sprintf(buf + len, " pid=%ld",
Christoph Lameter45edfa52007-05-09 02:32:45 -07003459 l->min_pid);
3460
Christoph Lameter84966342007-06-23 17:16:32 -07003461 if (num_online_cpus() > 1 && !cpus_empty(l->cpus) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003462 len < PAGE_SIZE - 60) {
3463 len += sprintf(buf + len, " cpus=");
3464 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003465 l->cpus);
3466 }
3467
Christoph Lameter84966342007-06-23 17:16:32 -07003468 if (num_online_nodes() > 1 && !nodes_empty(l->nodes) &&
Harvey Harrisone374d482008-01-31 15:20:50 -08003469 len < PAGE_SIZE - 60) {
3470 len += sprintf(buf + len, " nodes=");
3471 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
Christoph Lameter45edfa52007-05-09 02:32:45 -07003472 l->nodes);
3473 }
3474
Harvey Harrisone374d482008-01-31 15:20:50 -08003475 len += sprintf(buf + len, "\n");
Christoph Lameter88a420e2007-05-06 14:49:45 -07003476 }
3477
3478 free_loc_track(&t);
3479 if (!t.count)
Harvey Harrisone374d482008-01-31 15:20:50 -08003480 len += sprintf(buf, "No data\n");
3481 return len;
Christoph Lameter88a420e2007-05-06 14:49:45 -07003482}
3483
Christoph Lameter81819f02007-05-06 14:49:36 -07003484enum slab_stat_type {
3485 SL_FULL,
3486 SL_PARTIAL,
3487 SL_CPU,
3488 SL_OBJECTS
3489};
3490
3491#define SO_FULL (1 << SL_FULL)
3492#define SO_PARTIAL (1 << SL_PARTIAL)
3493#define SO_CPU (1 << SL_CPU)
3494#define SO_OBJECTS (1 << SL_OBJECTS)
3495
3496static unsigned long slab_objects(struct kmem_cache *s,
3497 char *buf, unsigned long flags)
3498{
3499 unsigned long total = 0;
3500 int cpu;
3501 int node;
3502 int x;
3503 unsigned long *nodes;
3504 unsigned long *per_cpu;
3505
3506 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
3507 per_cpu = nodes + nr_node_ids;
3508
3509 for_each_possible_cpu(cpu) {
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003510 struct page *page;
3511 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameter81819f02007-05-06 14:49:36 -07003512
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003513 if (!c)
3514 continue;
3515
3516 page = c->page;
Christoph Lameteree3c72a2007-10-16 01:26:07 -07003517 node = c->node;
3518 if (node < 0)
3519 continue;
Christoph Lameter81819f02007-05-06 14:49:36 -07003520 if (page) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003521 if (flags & SO_CPU) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003522 if (flags & SO_OBJECTS)
3523 x = page->inuse;
3524 else
3525 x = 1;
3526 total += x;
Christoph Lameteree3c72a2007-10-16 01:26:07 -07003527 nodes[node] += x;
Christoph Lameter81819f02007-05-06 14:49:36 -07003528 }
Christoph Lameteree3c72a2007-10-16 01:26:07 -07003529 per_cpu[node]++;
Christoph Lameter81819f02007-05-06 14:49:36 -07003530 }
3531 }
3532
Christoph Lameterf64dc582007-10-16 01:25:33 -07003533 for_each_node_state(node, N_NORMAL_MEMORY) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003534 struct kmem_cache_node *n = get_node(s, node);
3535
3536 if (flags & SO_PARTIAL) {
3537 if (flags & SO_OBJECTS)
3538 x = count_partial(n);
3539 else
3540 x = n->nr_partial;
3541 total += x;
3542 nodes[node] += x;
3543 }
3544
3545 if (flags & SO_FULL) {
Christoph Lameter9e869432007-08-22 14:01:56 -07003546 int full_slabs = atomic_long_read(&n->nr_slabs)
Christoph Lameter81819f02007-05-06 14:49:36 -07003547 - per_cpu[node]
3548 - n->nr_partial;
3549
3550 if (flags & SO_OBJECTS)
3551 x = full_slabs * s->objects;
3552 else
3553 x = full_slabs;
3554 total += x;
3555 nodes[node] += x;
3556 }
3557 }
3558
3559 x = sprintf(buf, "%lu", total);
3560#ifdef CONFIG_NUMA
Christoph Lameterf64dc582007-10-16 01:25:33 -07003561 for_each_node_state(node, N_NORMAL_MEMORY)
Christoph Lameter81819f02007-05-06 14:49:36 -07003562 if (nodes[node])
3563 x += sprintf(buf + x, " N%d=%lu",
3564 node, nodes[node]);
3565#endif
3566 kfree(nodes);
3567 return x + sprintf(buf + x, "\n");
3568}
3569
3570static int any_slab_objects(struct kmem_cache *s)
3571{
3572 int node;
3573 int cpu;
3574
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003575 for_each_possible_cpu(cpu) {
3576 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
Christoph Lameter81819f02007-05-06 14:49:36 -07003577
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003578 if (c && c->page)
3579 return 1;
3580 }
3581
3582 for_each_online_node(node) {
Christoph Lameter81819f02007-05-06 14:49:36 -07003583 struct kmem_cache_node *n = get_node(s, node);
3584
Christoph Lameterdfb4f092007-10-16 01:26:05 -07003585 if (!n)
3586 continue;
3587
Christoph Lameter9e869432007-08-22 14:01:56 -07003588 if (n->nr_partial || atomic_long_read(&n->nr_slabs))
Christoph Lameter81819f02007-05-06 14:49:36 -07003589 return 1;
3590 }
3591 return 0;
3592}
3593
3594#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3595#define to_slab(n) container_of(n, struct kmem_cache, kobj);
3596
3597struct slab_attribute {
3598 struct attribute attr;
3599 ssize_t (*show)(struct kmem_cache *s, char *buf);
3600 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
3601};
3602
3603#define SLAB_ATTR_RO(_name) \
3604 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3605
3606#define SLAB_ATTR(_name) \
3607 static struct slab_attribute _name##_attr = \
3608 __ATTR(_name, 0644, _name##_show, _name##_store)
3609
Christoph Lameter81819f02007-05-06 14:49:36 -07003610static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
3611{
3612 return sprintf(buf, "%d\n", s->size);
3613}
3614SLAB_ATTR_RO(slab_size);
3615
3616static ssize_t align_show(struct kmem_cache *s, char *buf)
3617{
3618 return sprintf(buf, "%d\n", s->align);
3619}
3620SLAB_ATTR_RO(align);
3621
3622static ssize_t object_size_show(struct kmem_cache *s, char *buf)
3623{
3624 return sprintf(buf, "%d\n", s->objsize);
3625}
3626SLAB_ATTR_RO(object_size);
3627
3628static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
3629{
3630 return sprintf(buf, "%d\n", s->objects);
3631}
3632SLAB_ATTR_RO(objs_per_slab);
3633
3634static ssize_t order_show(struct kmem_cache *s, char *buf)
3635{
3636 return sprintf(buf, "%d\n", s->order);
3637}
3638SLAB_ATTR_RO(order);
3639
3640static ssize_t ctor_show(struct kmem_cache *s, char *buf)
3641{
3642 if (s->ctor) {
3643 int n = sprint_symbol(buf, (unsigned long)s->ctor);
3644
3645 return n + sprintf(buf + n, "\n");
3646 }
3647 return 0;
3648}
3649SLAB_ATTR_RO(ctor);
3650
Christoph Lameter81819f02007-05-06 14:49:36 -07003651static ssize_t aliases_show(struct kmem_cache *s, char *buf)
3652{
3653 return sprintf(buf, "%d\n", s->refcount - 1);
3654}
3655SLAB_ATTR_RO(aliases);
3656
3657static ssize_t slabs_show(struct kmem_cache *s, char *buf)
3658{
3659 return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU);
3660}
3661SLAB_ATTR_RO(slabs);
3662
3663static ssize_t partial_show(struct kmem_cache *s, char *buf)
3664{
3665 return slab_objects(s, buf, SO_PARTIAL);
3666}
3667SLAB_ATTR_RO(partial);
3668
3669static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
3670{
3671 return slab_objects(s, buf, SO_CPU);
3672}
3673SLAB_ATTR_RO(cpu_slabs);
3674
3675static ssize_t objects_show(struct kmem_cache *s, char *buf)
3676{
3677 return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS);
3678}
3679SLAB_ATTR_RO(objects);
3680
3681static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
3682{
3683 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
3684}
3685
3686static ssize_t sanity_checks_store(struct kmem_cache *s,
3687 const char *buf, size_t length)
3688{
3689 s->flags &= ~SLAB_DEBUG_FREE;
3690 if (buf[0] == '1')
3691 s->flags |= SLAB_DEBUG_FREE;
3692 return length;
3693}
3694SLAB_ATTR(sanity_checks);
3695
3696static ssize_t trace_show(struct kmem_cache *s, char *buf)
3697{
3698 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
3699}
3700
3701static ssize_t trace_store(struct kmem_cache *s, const char *buf,
3702 size_t length)
3703{
3704 s->flags &= ~SLAB_TRACE;
3705 if (buf[0] == '1')
3706 s->flags |= SLAB_TRACE;
3707 return length;
3708}
3709SLAB_ATTR(trace);
3710
3711static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
3712{
3713 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
3714}
3715
3716static ssize_t reclaim_account_store(struct kmem_cache *s,
3717 const char *buf, size_t length)
3718{
3719 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
3720 if (buf[0] == '1')
3721 s->flags |= SLAB_RECLAIM_ACCOUNT;
3722 return length;
3723}
3724SLAB_ATTR(reclaim_account);
3725
3726static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
3727{
Christoph Lameter5af60832007-05-06 14:49:56 -07003728 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
Christoph Lameter81819f02007-05-06 14:49:36 -07003729}
3730SLAB_ATTR_RO(hwcache_align);
3731
3732#ifdef CONFIG_ZONE_DMA
3733static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
3734{
3735 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
3736}
3737SLAB_ATTR_RO(cache_dma);
3738#endif
3739
3740static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
3741{
3742 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
3743}
3744SLAB_ATTR_RO(destroy_by_rcu);
3745
3746static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
3747{
3748 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
3749}
3750
3751static ssize_t red_zone_store(struct kmem_cache *s,
3752 const char *buf, size_t length)
3753{
3754 if (any_slab_objects(s))
3755 return -EBUSY;
3756
3757 s->flags &= ~SLAB_RED_ZONE;
3758 if (buf[0] == '1')
3759 s->flags |= SLAB_RED_ZONE;
3760 calculate_sizes(s);
3761 return length;
3762}
3763SLAB_ATTR(red_zone);
3764
3765static ssize_t poison_show(struct kmem_cache *s, char *buf)
3766{
3767 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
3768}
3769
3770static ssize_t poison_store(struct kmem_cache *s,
3771 const char *buf, size_t length)
3772{
3773 if (any_slab_objects(s))
3774 return -EBUSY;
3775
3776 s->flags &= ~SLAB_POISON;
3777 if (buf[0] == '1')
3778 s->flags |= SLAB_POISON;
3779 calculate_sizes(s);
3780 return length;
3781}
3782SLAB_ATTR(poison);
3783
3784static ssize_t store_user_show(struct kmem_cache *s, char *buf)
3785{
3786 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
3787}
3788
3789static ssize_t store_user_store(struct kmem_cache *s,
3790 const char *buf, size_t length)
3791{
3792 if (any_slab_objects(s))
3793 return -EBUSY;
3794
3795 s->flags &= ~SLAB_STORE_USER;
3796 if (buf[0] == '1')
3797 s->flags |= SLAB_STORE_USER;
3798 calculate_sizes(s);
3799 return length;
3800}
3801SLAB_ATTR(store_user);
3802
Christoph Lameter53e15af2007-05-06 14:49:43 -07003803static ssize_t validate_show(struct kmem_cache *s, char *buf)
3804{
3805 return 0;
3806}
3807
3808static ssize_t validate_store(struct kmem_cache *s,
3809 const char *buf, size_t length)
3810{
Christoph Lameter434e2452007-07-17 04:03:30 -07003811 int ret = -EINVAL;
3812
3813 if (buf[0] == '1') {
3814 ret = validate_slab_cache(s);
3815 if (ret >= 0)
3816 ret = length;
3817 }
3818 return ret;
Christoph Lameter53e15af2007-05-06 14:49:43 -07003819}
3820SLAB_ATTR(validate);
3821
Christoph Lameter2086d262007-05-06 14:49:46 -07003822static ssize_t shrink_show(struct kmem_cache *s, char *buf)
3823{
3824 return 0;
3825}
3826
3827static ssize_t shrink_store(struct kmem_cache *s,
3828 const char *buf, size_t length)
3829{
3830 if (buf[0] == '1') {
3831 int rc = kmem_cache_shrink(s);
3832
3833 if (rc)
3834 return rc;
3835 } else
3836 return -EINVAL;
3837 return length;
3838}
3839SLAB_ATTR(shrink);
3840
Christoph Lameter88a420e2007-05-06 14:49:45 -07003841static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
3842{
3843 if (!(s->flags & SLAB_STORE_USER))
3844 return -ENOSYS;
3845 return list_locations(s, buf, TRACK_ALLOC);
3846}
3847SLAB_ATTR_RO(alloc_calls);
3848
3849static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
3850{
3851 if (!(s->flags & SLAB_STORE_USER))
3852 return -ENOSYS;
3853 return list_locations(s, buf, TRACK_FREE);
3854}
3855SLAB_ATTR_RO(free_calls);
3856
Christoph Lameter81819f02007-05-06 14:49:36 -07003857#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08003858static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
Christoph Lameter81819f02007-05-06 14:49:36 -07003859{
Christoph Lameter98246012008-01-07 23:20:26 -08003860 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
Christoph Lameter81819f02007-05-06 14:49:36 -07003861}
3862
Christoph Lameter98246012008-01-07 23:20:26 -08003863static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
Christoph Lameter81819f02007-05-06 14:49:36 -07003864 const char *buf, size_t length)
3865{
3866 int n = simple_strtoul(buf, NULL, 10);
3867
3868 if (n < 100)
Christoph Lameter98246012008-01-07 23:20:26 -08003869 s->remote_node_defrag_ratio = n * 10;
Christoph Lameter81819f02007-05-06 14:49:36 -07003870 return length;
3871}
Christoph Lameter98246012008-01-07 23:20:26 -08003872SLAB_ATTR(remote_node_defrag_ratio);
Christoph Lameter81819f02007-05-06 14:49:36 -07003873#endif
3874
Pekka Enberg06428782008-01-07 23:20:27 -08003875static struct attribute *slab_attrs[] = {
Christoph Lameter81819f02007-05-06 14:49:36 -07003876 &slab_size_attr.attr,
3877 &object_size_attr.attr,
3878 &objs_per_slab_attr.attr,
3879 &order_attr.attr,
3880 &objects_attr.attr,
3881 &slabs_attr.attr,
3882 &partial_attr.attr,
3883 &cpu_slabs_attr.attr,
3884 &ctor_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07003885 &aliases_attr.attr,
3886 &align_attr.attr,
3887 &sanity_checks_attr.attr,
3888 &trace_attr.attr,
3889 &hwcache_align_attr.attr,
3890 &reclaim_account_attr.attr,
3891 &destroy_by_rcu_attr.attr,
3892 &red_zone_attr.attr,
3893 &poison_attr.attr,
3894 &store_user_attr.attr,
Christoph Lameter53e15af2007-05-06 14:49:43 -07003895 &validate_attr.attr,
Christoph Lameter2086d262007-05-06 14:49:46 -07003896 &shrink_attr.attr,
Christoph Lameter88a420e2007-05-06 14:49:45 -07003897 &alloc_calls_attr.attr,
3898 &free_calls_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07003899#ifdef CONFIG_ZONE_DMA
3900 &cache_dma_attr.attr,
3901#endif
3902#ifdef CONFIG_NUMA
Christoph Lameter98246012008-01-07 23:20:26 -08003903 &remote_node_defrag_ratio_attr.attr,
Christoph Lameter81819f02007-05-06 14:49:36 -07003904#endif
3905 NULL
3906};
3907
3908static struct attribute_group slab_attr_group = {
3909 .attrs = slab_attrs,
3910};
3911
3912static ssize_t slab_attr_show(struct kobject *kobj,
3913 struct attribute *attr,
3914 char *buf)
3915{
3916 struct slab_attribute *attribute;
3917 struct kmem_cache *s;
3918 int err;
3919
3920 attribute = to_slab_attr(attr);
3921 s = to_slab(kobj);
3922
3923 if (!attribute->show)
3924 return -EIO;
3925
3926 err = attribute->show(s, buf);
3927
3928 return err;
3929}
3930
3931static ssize_t slab_attr_store(struct kobject *kobj,
3932 struct attribute *attr,
3933 const char *buf, size_t len)
3934{
3935 struct slab_attribute *attribute;
3936 struct kmem_cache *s;
3937 int err;
3938
3939 attribute = to_slab_attr(attr);
3940 s = to_slab(kobj);
3941
3942 if (!attribute->store)
3943 return -EIO;
3944
3945 err = attribute->store(s, buf, len);
3946
3947 return err;
3948}
3949
Christoph Lameter151c6022008-01-07 22:29:05 -08003950static void kmem_cache_release(struct kobject *kobj)
3951{
3952 struct kmem_cache *s = to_slab(kobj);
3953
3954 kfree(s);
3955}
3956
Christoph Lameter81819f02007-05-06 14:49:36 -07003957static struct sysfs_ops slab_sysfs_ops = {
3958 .show = slab_attr_show,
3959 .store = slab_attr_store,
3960};
3961
3962static struct kobj_type slab_ktype = {
3963 .sysfs_ops = &slab_sysfs_ops,
Christoph Lameter151c6022008-01-07 22:29:05 -08003964 .release = kmem_cache_release
Christoph Lameter81819f02007-05-06 14:49:36 -07003965};
3966
3967static int uevent_filter(struct kset *kset, struct kobject *kobj)
3968{
3969 struct kobj_type *ktype = get_ktype(kobj);
3970
3971 if (ktype == &slab_ktype)
3972 return 1;
3973 return 0;
3974}
3975
3976static struct kset_uevent_ops slab_uevent_ops = {
3977 .filter = uevent_filter,
3978};
3979
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06003980static struct kset *slab_kset;
Christoph Lameter81819f02007-05-06 14:49:36 -07003981
3982#define ID_STR_LENGTH 64
3983
3984/* Create a unique string id for a slab cache:
3985 * format
3986 * :[flags-]size:[memory address of kmemcache]
3987 */
3988static char *create_unique_id(struct kmem_cache *s)
3989{
3990 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
3991 char *p = name;
3992
3993 BUG_ON(!name);
3994
3995 *p++ = ':';
3996 /*
3997 * First flags affecting slabcache operations. We will only
3998 * get here for aliasable slabs so we do not need to support
3999 * too many flags. The flags here must cover all flags that
4000 * are matched during merging to guarantee that the id is
4001 * unique.
4002 */
4003 if (s->flags & SLAB_CACHE_DMA)
4004 *p++ = 'd';
4005 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4006 *p++ = 'a';
4007 if (s->flags & SLAB_DEBUG_FREE)
4008 *p++ = 'F';
4009 if (p != name + 1)
4010 *p++ = '-';
4011 p += sprintf(p, "%07d", s->size);
4012 BUG_ON(p > name + ID_STR_LENGTH - 1);
4013 return name;
4014}
4015
4016static int sysfs_slab_add(struct kmem_cache *s)
4017{
4018 int err;
4019 const char *name;
4020 int unmergeable;
4021
4022 if (slab_state < SYSFS)
4023 /* Defer until later */
4024 return 0;
4025
4026 unmergeable = slab_unmergeable(s);
4027 if (unmergeable) {
4028 /*
4029 * Slabcache can never be merged so we can use the name proper.
4030 * This is typically the case for debug situations. In that
4031 * case we can catch duplicate names easily.
4032 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004033 sysfs_remove_link(&slab_kset->kobj, s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004034 name = s->name;
4035 } else {
4036 /*
4037 * Create a unique name for the slab as a target
4038 * for the symlinks.
4039 */
4040 name = create_unique_id(s);
4041 }
4042
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004043 s->kobj.kset = slab_kset;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004044 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4045 if (err) {
4046 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004047 return err;
Greg Kroah-Hartman1eada112007-12-17 23:05:35 -07004048 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004049
4050 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4051 if (err)
4052 return err;
4053 kobject_uevent(&s->kobj, KOBJ_ADD);
4054 if (!unmergeable) {
4055 /* Setup first alias */
4056 sysfs_slab_alias(s, s->name);
4057 kfree(name);
4058 }
4059 return 0;
4060}
4061
4062static void sysfs_slab_remove(struct kmem_cache *s)
4063{
4064 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4065 kobject_del(&s->kobj);
Christoph Lameter151c6022008-01-07 22:29:05 -08004066 kobject_put(&s->kobj);
Christoph Lameter81819f02007-05-06 14:49:36 -07004067}
4068
4069/*
4070 * Need to buffer aliases during bootup until sysfs becomes
4071 * available lest we loose that information.
4072 */
4073struct saved_alias {
4074 struct kmem_cache *s;
4075 const char *name;
4076 struct saved_alias *next;
4077};
4078
Adrian Bunk5af328a2007-07-17 04:03:27 -07004079static struct saved_alias *alias_list;
Christoph Lameter81819f02007-05-06 14:49:36 -07004080
4081static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4082{
4083 struct saved_alias *al;
4084
4085 if (slab_state == SYSFS) {
4086 /*
4087 * If we have a leftover link then remove it.
4088 */
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004089 sysfs_remove_link(&slab_kset->kobj, name);
4090 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004091 }
4092
4093 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4094 if (!al)
4095 return -ENOMEM;
4096
4097 al->s = s;
4098 al->name = name;
4099 al->next = alias_list;
4100 alias_list = al;
4101 return 0;
4102}
4103
4104static int __init slab_sysfs_init(void)
4105{
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004106 struct kmem_cache *s;
Christoph Lameter81819f02007-05-06 14:49:36 -07004107 int err;
4108
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -08004109 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
Greg Kroah-Hartman27c3a312007-11-01 09:29:06 -06004110 if (!slab_kset) {
Christoph Lameter81819f02007-05-06 14:49:36 -07004111 printk(KERN_ERR "Cannot register slab subsystem.\n");
4112 return -ENOSYS;
4113 }
4114
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004115 slab_state = SYSFS;
4116
Christoph Lameter5b95a4a2007-07-17 04:03:19 -07004117 list_for_each_entry(s, &slab_caches, list) {
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004118 err = sysfs_slab_add(s);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004119 if (err)
4120 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4121 " to sysfs\n", s->name);
Christoph Lameter26a7bd02007-05-09 02:32:39 -07004122 }
Christoph Lameter81819f02007-05-06 14:49:36 -07004123
4124 while (alias_list) {
4125 struct saved_alias *al = alias_list;
4126
4127 alias_list = alias_list->next;
4128 err = sysfs_slab_alias(al->s, al->name);
Christoph Lameter5d540fb2007-08-30 23:56:26 -07004129 if (err)
4130 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4131 " %s to sysfs\n", s->name);
Christoph Lameter81819f02007-05-06 14:49:36 -07004132 kfree(al);
4133 }
4134
4135 resiliency_test();
4136 return 0;
4137}
4138
4139__initcall(slab_sysfs_init);
Christoph Lameter81819f02007-05-06 14:49:36 -07004140#endif
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004141
4142/*
4143 * The /proc/slabinfo ABI
4144 */
Linus Torvalds158a9622008-01-02 13:04:48 -08004145#ifdef CONFIG_SLABINFO
4146
4147ssize_t slabinfo_write(struct file *file, const char __user * buffer,
4148 size_t count, loff_t *ppos)
4149{
4150 return -EINVAL;
4151}
4152
Pekka J Enberg57ed3ed2008-01-01 17:23:28 +01004153
4154static void print_slabinfo_header(struct seq_file *m)
4155{
4156 seq_puts(m, "slabinfo - version: 2.1\n");
4157 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4158 "<objperslab> <pagesperslab>");
4159 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4160 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4161 seq_putc(m, '\n');
4162}
4163
4164static void *s_start(struct seq_file *m, loff_t *pos)
4165{
4166 loff_t n = *pos;
4167
4168 down_read(&slub_lock);
4169 if (!n)
4170 print_slabinfo_header(m);
4171
4172 return seq_list_start(&slab_caches, *pos);
4173}
4174
4175static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4176{
4177 return seq_list_next(p, &slab_caches, pos);
4178}
4179
4180static void s_stop(struct seq_file *m, void *p)
4181{
4182 up_read(&slub_lock);
4183}
4184
4185static int s_show(struct seq_file *m, void *p)
4186{
4187 unsigned long nr_partials = 0;
4188 unsigned long nr_slabs = 0;
4189 unsigned long nr_inuse = 0;
4190 unsigned long nr_objs;
4191 struct kmem_cache *s;
4192 int node;
4193
4194 s = list_entry(p, struct kmem_cache, list);
4195
4196 for_each_online_node(node) {
4197 struct kmem_cache_node *n = get_node(s, node);
4198
4199 if (!n)
4200 continue;
4201
4202 nr_partials += n->nr_partial;
4203 nr_slabs += atomic_long_read(&n->nr_slabs);
4204 nr_inuse += count_partial(n);
4205 }
4206
4207 nr_objs = nr_slabs * s->objects;
4208 nr_inuse += (nr_slabs - nr_partials) * s->objects;
4209
4210 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
4211 nr_objs, s->size, s->objects, (1 << s->order));
4212 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4213 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4214 0UL);
4215 seq_putc(m, '\n');
4216 return 0;
4217}
4218
4219const struct seq_operations slabinfo_op = {
4220 .start = s_start,
4221 .next = s_next,
4222 .stop = s_stop,
4223 .show = s_show,
4224};
4225
Linus Torvalds158a9622008-01-02 13:04:48 -08004226#endif /* CONFIG_SLABINFO */