Linux 2.6.25-rc7
[deliverable/linux.git] / mm / slub.c
CommitLineData
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1/*
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>
b9049e23 23#include <linux/memory.h>
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24
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 *
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70 * 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
81819f0f 72 * freed then the slab will show up again on the partial lists.
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73 * We track full slabs for debugging purposes though because otherwise we
74 * cannot scan all objects.
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75 *
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 *
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82 * 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
dfb4f096 94 * freelist that allows lockless access to
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95 * free objects in addition to the regular freelist
96 * that requires the slab lock.
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97 *
98 * PageError Slab requires special handling due to debug
99 * options set. This moves slab handling out of
894b8788 100 * the fast path and disables lockless freelists.
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101 */
102
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103#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
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111static inline int SlabFrozen(struct page *page)
112{
5577bd8a 113 return page->flags & FROZEN;
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114}
115
116static inline void SetSlabFrozen(struct page *page)
117{
5577bd8a 118 page->flags |= FROZEN;
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119}
120
121static inline void ClearSlabFrozen(struct page *page)
122{
5577bd8a 123 page->flags &= ~FROZEN;
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124}
125
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126static inline int SlabDebug(struct page *page)
127{
5577bd8a 128 return page->flags & SLABDEBUG;
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129}
130
131static inline void SetSlabDebug(struct page *page)
132{
5577bd8a 133 page->flags |= SLABDEBUG;
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134}
135
136static inline void ClearSlabDebug(struct page *page)
137{
5577bd8a 138 page->flags &= ~SLABDEBUG;
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139}
140
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141/*
142 * Issues still to be resolved:
143 *
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144 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
145 *
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146 * - 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
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171/*
172 * 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 */
76be8950 175#define MIN_PARTIAL 5
e95eed57 176
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177/*
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
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184#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
185 SLAB_POISON | SLAB_STORE_USER)
672bba3a 186
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187/*
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
47bfdc0d 197#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
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198#endif
199
200#ifndef ARCH_SLAB_MINALIGN
47bfdc0d 201#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
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202#endif
203
204/* Internal SLUB flags */
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205#define __OBJECT_POISON 0x80000000 /* Poison object */
206#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
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207#define __KMALLOC_CACHE 0x20000000 /* objects freed using kfree */
208#define __PAGE_ALLOC_FALLBACK 0x10000000 /* Allow fallback to page alloc */
81819f0f 209
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210/* Not all arches define cache_line_size */
211#ifndef cache_line_size
212#define cache_line_size() L1_CACHE_BYTES
213#endif
214
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215static int kmem_size = sizeof(struct kmem_cache);
216
217#ifdef CONFIG_SMP
218static struct notifier_block slab_notifier;
219#endif
220
221static enum {
222 DOWN, /* No slab functionality available */
223 PARTIAL, /* kmem_cache_open() works but kmalloc does not */
672bba3a 224 UP, /* Everything works but does not show up in sysfs */
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225 SYSFS /* Sysfs up */
226} slab_state = DOWN;
227
228/* A list of all slab caches on the system */
229static DECLARE_RWSEM(slub_lock);
5af328a5 230static LIST_HEAD(slab_caches);
81819f0f 231
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232/*
233 * Tracking user of a slab.
234 */
235struct track {
236 void *addr; /* Called from address */
237 int cpu; /* Was running on cpu */
238 int pid; /* Pid context */
239 unsigned long when; /* When did the operation occur */
240};
241
242enum track_item { TRACK_ALLOC, TRACK_FREE };
243
41ecc55b 244#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
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245static int sysfs_slab_add(struct kmem_cache *);
246static int sysfs_slab_alias(struct kmem_cache *, const char *);
247static void sysfs_slab_remove(struct kmem_cache *);
8ff12cfc 248
81819f0f 249#else
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250static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
251static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
252 { return 0; }
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253static inline void sysfs_slab_remove(struct kmem_cache *s)
254{
255 kfree(s);
256}
8ff12cfc 257
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258#endif
259
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260static inline void stat(struct kmem_cache_cpu *c, enum stat_item si)
261{
262#ifdef CONFIG_SLUB_STATS
263 c->stat[si]++;
264#endif
265}
266
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267/********************************************************************
268 * Core slab cache functions
269 *******************************************************************/
270
271int slab_is_available(void)
272{
273 return slab_state >= UP;
274}
275
276static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
277{
278#ifdef CONFIG_NUMA
279 return s->node[node];
280#else
281 return &s->local_node;
282#endif
283}
284
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285static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu)
286{
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287#ifdef CONFIG_SMP
288 return s->cpu_slab[cpu];
289#else
290 return &s->cpu_slab;
291#endif
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292}
293
6446faa2 294/* Verify that a pointer has an address that is valid within a slab page */
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295static inline int check_valid_pointer(struct kmem_cache *s,
296 struct page *page, const void *object)
297{
298 void *base;
299
a973e9dd 300 if (!object)
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301 return 1;
302
a973e9dd 303 base = page_address(page);
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304 if (object < base || object >= base + s->objects * s->size ||
305 (object - base) % s->size) {
306 return 0;
307 }
308
309 return 1;
310}
311
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312/*
313 * Slow version of get and set free pointer.
314 *
315 * This version requires touching the cache lines of kmem_cache which
316 * we avoid to do in the fast alloc free paths. There we obtain the offset
317 * from the page struct.
318 */
319static inline void *get_freepointer(struct kmem_cache *s, void *object)
320{
321 return *(void **)(object + s->offset);
322}
323
324static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
325{
326 *(void **)(object + s->offset) = fp;
327}
328
329/* Loop over all objects in a slab */
330#define for_each_object(__p, __s, __addr) \
331 for (__p = (__addr); __p < (__addr) + (__s)->objects * (__s)->size;\
332 __p += (__s)->size)
333
334/* Scan freelist */
335#define for_each_free_object(__p, __s, __free) \
a973e9dd 336 for (__p = (__free); __p; __p = get_freepointer((__s), __p))
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337
338/* Determine object index from a given position */
339static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
340{
341 return (p - addr) / s->size;
342}
343
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344#ifdef CONFIG_SLUB_DEBUG
345/*
346 * Debug settings:
347 */
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348#ifdef CONFIG_SLUB_DEBUG_ON
349static int slub_debug = DEBUG_DEFAULT_FLAGS;
350#else
41ecc55b 351static int slub_debug;
f0630fff 352#endif
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353
354static char *slub_debug_slabs;
355
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356/*
357 * Object debugging
358 */
359static void print_section(char *text, u8 *addr, unsigned int length)
360{
361 int i, offset;
362 int newline = 1;
363 char ascii[17];
364
365 ascii[16] = 0;
366
367 for (i = 0; i < length; i++) {
368 if (newline) {
24922684 369 printk(KERN_ERR "%8s 0x%p: ", text, addr + i);
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370 newline = 0;
371 }
06428780 372 printk(KERN_CONT " %02x", addr[i]);
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373 offset = i % 16;
374 ascii[offset] = isgraph(addr[i]) ? addr[i] : '.';
375 if (offset == 15) {
06428780 376 printk(KERN_CONT " %s\n", ascii);
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377 newline = 1;
378 }
379 }
380 if (!newline) {
381 i %= 16;
382 while (i < 16) {
06428780 383 printk(KERN_CONT " ");
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384 ascii[i] = ' ';
385 i++;
386 }
06428780 387 printk(KERN_CONT " %s\n", ascii);
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388 }
389}
390
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391static struct track *get_track(struct kmem_cache *s, void *object,
392 enum track_item alloc)
393{
394 struct track *p;
395
396 if (s->offset)
397 p = object + s->offset + sizeof(void *);
398 else
399 p = object + s->inuse;
400
401 return p + alloc;
402}
403
404static void set_track(struct kmem_cache *s, void *object,
405 enum track_item alloc, void *addr)
406{
407 struct track *p;
408
409 if (s->offset)
410 p = object + s->offset + sizeof(void *);
411 else
412 p = object + s->inuse;
413
414 p += alloc;
415 if (addr) {
416 p->addr = addr;
417 p->cpu = smp_processor_id();
418 p->pid = current ? current->pid : -1;
419 p->when = jiffies;
420 } else
421 memset(p, 0, sizeof(struct track));
422}
423
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424static void init_tracking(struct kmem_cache *s, void *object)
425{
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426 if (!(s->flags & SLAB_STORE_USER))
427 return;
428
429 set_track(s, object, TRACK_FREE, NULL);
430 set_track(s, object, TRACK_ALLOC, NULL);
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431}
432
433static void print_track(const char *s, struct track *t)
434{
435 if (!t->addr)
436 return;
437
24922684 438 printk(KERN_ERR "INFO: %s in ", s);
81819f0f 439 __print_symbol("%s", (unsigned long)t->addr);
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440 printk(" age=%lu cpu=%u pid=%d\n", jiffies - t->when, t->cpu, t->pid);
441}
442
443static void print_tracking(struct kmem_cache *s, void *object)
444{
445 if (!(s->flags & SLAB_STORE_USER))
446 return;
447
448 print_track("Allocated", get_track(s, object, TRACK_ALLOC));
449 print_track("Freed", get_track(s, object, TRACK_FREE));
450}
451
452static void print_page_info(struct page *page)
453{
454 printk(KERN_ERR "INFO: Slab 0x%p used=%u fp=0x%p flags=0x%04lx\n",
455 page, page->inuse, page->freelist, page->flags);
456
457}
458
459static void slab_bug(struct kmem_cache *s, char *fmt, ...)
460{
461 va_list args;
462 char buf[100];
463
464 va_start(args, fmt);
465 vsnprintf(buf, sizeof(buf), fmt, args);
466 va_end(args);
467 printk(KERN_ERR "========================================"
468 "=====================================\n");
469 printk(KERN_ERR "BUG %s: %s\n", s->name, buf);
470 printk(KERN_ERR "----------------------------------------"
471 "-------------------------------------\n\n");
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472}
473
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474static void slab_fix(struct kmem_cache *s, char *fmt, ...)
475{
476 va_list args;
477 char buf[100];
478
479 va_start(args, fmt);
480 vsnprintf(buf, sizeof(buf), fmt, args);
481 va_end(args);
482 printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
483}
484
485static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
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486{
487 unsigned int off; /* Offset of last byte */
a973e9dd 488 u8 *addr = page_address(page);
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489
490 print_tracking(s, p);
491
492 print_page_info(page);
493
494 printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
495 p, p - addr, get_freepointer(s, p));
496
497 if (p > addr + 16)
498 print_section("Bytes b4", p - 16, 16);
499
500 print_section("Object", p, min(s->objsize, 128));
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501
502 if (s->flags & SLAB_RED_ZONE)
503 print_section("Redzone", p + s->objsize,
504 s->inuse - s->objsize);
505
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506 if (s->offset)
507 off = s->offset + sizeof(void *);
508 else
509 off = s->inuse;
510
24922684 511 if (s->flags & SLAB_STORE_USER)
81819f0f 512 off += 2 * sizeof(struct track);
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513
514 if (off != s->size)
515 /* Beginning of the filler is the free pointer */
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516 print_section("Padding", p + off, s->size - off);
517
518 dump_stack();
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519}
520
521static void object_err(struct kmem_cache *s, struct page *page,
522 u8 *object, char *reason)
523{
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524 slab_bug(s, reason);
525 print_trailer(s, page, object);
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526}
527
24922684 528static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
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529{
530 va_list args;
531 char buf[100];
532
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533 va_start(args, fmt);
534 vsnprintf(buf, sizeof(buf), fmt, args);
81819f0f 535 va_end(args);
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536 slab_bug(s, fmt);
537 print_page_info(page);
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538 dump_stack();
539}
540
541static void init_object(struct kmem_cache *s, void *object, int active)
542{
543 u8 *p = object;
544
545 if (s->flags & __OBJECT_POISON) {
546 memset(p, POISON_FREE, s->objsize - 1);
06428780 547 p[s->objsize - 1] = POISON_END;
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548 }
549
550 if (s->flags & SLAB_RED_ZONE)
551 memset(p + s->objsize,
552 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE,
553 s->inuse - s->objsize);
554}
555
24922684 556static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes)
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557{
558 while (bytes) {
559 if (*start != (u8)value)
24922684 560 return start;
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561 start++;
562 bytes--;
563 }
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564 return NULL;
565}
566
567static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
568 void *from, void *to)
569{
570 slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
571 memset(from, data, to - from);
572}
573
574static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
575 u8 *object, char *what,
06428780 576 u8 *start, unsigned int value, unsigned int bytes)
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577{
578 u8 *fault;
579 u8 *end;
580
581 fault = check_bytes(start, value, bytes);
582 if (!fault)
583 return 1;
584
585 end = start + bytes;
586 while (end > fault && end[-1] == value)
587 end--;
588
589 slab_bug(s, "%s overwritten", what);
590 printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
591 fault, end - 1, fault[0], value);
592 print_trailer(s, page, object);
593
594 restore_bytes(s, what, value, fault, end);
595 return 0;
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596}
597
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598/*
599 * Object layout:
600 *
601 * object address
602 * Bytes of the object to be managed.
603 * If the freepointer may overlay the object then the free
604 * pointer is the first word of the object.
672bba3a 605 *
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606 * Poisoning uses 0x6b (POISON_FREE) and the last byte is
607 * 0xa5 (POISON_END)
608 *
609 * object + s->objsize
610 * Padding to reach word boundary. This is also used for Redzoning.
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611 * Padding is extended by another word if Redzoning is enabled and
612 * objsize == inuse.
613 *
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614 * We fill with 0xbb (RED_INACTIVE) for inactive objects and with
615 * 0xcc (RED_ACTIVE) for objects in use.
616 *
617 * object + s->inuse
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618 * Meta data starts here.
619 *
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620 * A. Free pointer (if we cannot overwrite object on free)
621 * B. Tracking data for SLAB_STORE_USER
672bba3a 622 * C. Padding to reach required alignment boundary or at mininum
6446faa2 623 * one word if debugging is on to be able to detect writes
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624 * before the word boundary.
625 *
626 * Padding is done using 0x5a (POISON_INUSE)
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627 *
628 * object + s->size
672bba3a 629 * Nothing is used beyond s->size.
81819f0f 630 *
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631 * If slabcaches are merged then the objsize and inuse boundaries are mostly
632 * ignored. And therefore no slab options that rely on these boundaries
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633 * may be used with merged slabcaches.
634 */
635
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636static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
637{
638 unsigned long off = s->inuse; /* The end of info */
639
640 if (s->offset)
641 /* Freepointer is placed after the object. */
642 off += sizeof(void *);
643
644 if (s->flags & SLAB_STORE_USER)
645 /* We also have user information there */
646 off += 2 * sizeof(struct track);
647
648 if (s->size == off)
649 return 1;
650
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651 return check_bytes_and_report(s, page, p, "Object padding",
652 p + off, POISON_INUSE, s->size - off);
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653}
654
655static int slab_pad_check(struct kmem_cache *s, struct page *page)
656{
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CL
657 u8 *start;
658 u8 *fault;
659 u8 *end;
660 int length;
661 int remainder;
81819f0f
CL
662
663 if (!(s->flags & SLAB_POISON))
664 return 1;
665
a973e9dd 666 start = page_address(page);
24922684 667 end = start + (PAGE_SIZE << s->order);
81819f0f 668 length = s->objects * s->size;
24922684 669 remainder = end - (start + length);
81819f0f
CL
670 if (!remainder)
671 return 1;
672
24922684
CL
673 fault = check_bytes(start + length, POISON_INUSE, remainder);
674 if (!fault)
675 return 1;
676 while (end > fault && end[-1] == POISON_INUSE)
677 end--;
678
679 slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
680 print_section("Padding", start, length);
681
682 restore_bytes(s, "slab padding", POISON_INUSE, start, end);
683 return 0;
81819f0f
CL
684}
685
686static int check_object(struct kmem_cache *s, struct page *page,
687 void *object, int active)
688{
689 u8 *p = object;
690 u8 *endobject = object + s->objsize;
691
692 if (s->flags & SLAB_RED_ZONE) {
693 unsigned int red =
694 active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE;
695
24922684
CL
696 if (!check_bytes_and_report(s, page, object, "Redzone",
697 endobject, red, s->inuse - s->objsize))
81819f0f 698 return 0;
81819f0f 699 } else {
3adbefee
IM
700 if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
701 check_bytes_and_report(s, page, p, "Alignment padding",
702 endobject, POISON_INUSE, s->inuse - s->objsize);
703 }
81819f0f
CL
704 }
705
706 if (s->flags & SLAB_POISON) {
707 if (!active && (s->flags & __OBJECT_POISON) &&
24922684
CL
708 (!check_bytes_and_report(s, page, p, "Poison", p,
709 POISON_FREE, s->objsize - 1) ||
710 !check_bytes_and_report(s, page, p, "Poison",
06428780 711 p + s->objsize - 1, POISON_END, 1)))
81819f0f 712 return 0;
81819f0f
CL
713 /*
714 * check_pad_bytes cleans up on its own.
715 */
716 check_pad_bytes(s, page, p);
717 }
718
719 if (!s->offset && active)
720 /*
721 * Object and freepointer overlap. Cannot check
722 * freepointer while object is allocated.
723 */
724 return 1;
725
726 /* Check free pointer validity */
727 if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
728 object_err(s, page, p, "Freepointer corrupt");
729 /*
730 * No choice but to zap it and thus loose the remainder
731 * of the free objects in this slab. May cause
672bba3a 732 * another error because the object count is now wrong.
81819f0f 733 */
a973e9dd 734 set_freepointer(s, p, NULL);
81819f0f
CL
735 return 0;
736 }
737 return 1;
738}
739
740static int check_slab(struct kmem_cache *s, struct page *page)
741{
742 VM_BUG_ON(!irqs_disabled());
743
744 if (!PageSlab(page)) {
24922684 745 slab_err(s, page, "Not a valid slab page");
81819f0f
CL
746 return 0;
747 }
81819f0f 748 if (page->inuse > s->objects) {
24922684
CL
749 slab_err(s, page, "inuse %u > max %u",
750 s->name, page->inuse, s->objects);
81819f0f
CL
751 return 0;
752 }
753 /* Slab_pad_check fixes things up after itself */
754 slab_pad_check(s, page);
755 return 1;
756}
757
758/*
672bba3a
CL
759 * Determine if a certain object on a page is on the freelist. Must hold the
760 * slab lock to guarantee that the chains are in a consistent state.
81819f0f
CL
761 */
762static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
763{
764 int nr = 0;
765 void *fp = page->freelist;
766 void *object = NULL;
767
a973e9dd 768 while (fp && nr <= s->objects) {
81819f0f
CL
769 if (fp == search)
770 return 1;
771 if (!check_valid_pointer(s, page, fp)) {
772 if (object) {
773 object_err(s, page, object,
774 "Freechain corrupt");
a973e9dd 775 set_freepointer(s, object, NULL);
81819f0f
CL
776 break;
777 } else {
24922684 778 slab_err(s, page, "Freepointer corrupt");
a973e9dd 779 page->freelist = NULL;
81819f0f 780 page->inuse = s->objects;
24922684 781 slab_fix(s, "Freelist cleared");
81819f0f
CL
782 return 0;
783 }
784 break;
785 }
786 object = fp;
787 fp = get_freepointer(s, object);
788 nr++;
789 }
790
791 if (page->inuse != s->objects - nr) {
70d71228 792 slab_err(s, page, "Wrong object count. Counter is %d but "
24922684 793 "counted were %d", page->inuse, s->objects - nr);
81819f0f 794 page->inuse = s->objects - nr;
24922684 795 slab_fix(s, "Object count adjusted.");
81819f0f
CL
796 }
797 return search == NULL;
798}
799
3ec09742
CL
800static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc)
801{
802 if (s->flags & SLAB_TRACE) {
803 printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
804 s->name,
805 alloc ? "alloc" : "free",
806 object, page->inuse,
807 page->freelist);
808
809 if (!alloc)
810 print_section("Object", (void *)object, s->objsize);
811
812 dump_stack();
813 }
814}
815
643b1138 816/*
672bba3a 817 * Tracking of fully allocated slabs for debugging purposes.
643b1138 818 */
e95eed57 819static void add_full(struct kmem_cache_node *n, struct page *page)
643b1138 820{
643b1138
CL
821 spin_lock(&n->list_lock);
822 list_add(&page->lru, &n->full);
823 spin_unlock(&n->list_lock);
824}
825
826static void remove_full(struct kmem_cache *s, struct page *page)
827{
828 struct kmem_cache_node *n;
829
830 if (!(s->flags & SLAB_STORE_USER))
831 return;
832
833 n = get_node(s, page_to_nid(page));
834
835 spin_lock(&n->list_lock);
836 list_del(&page->lru);
837 spin_unlock(&n->list_lock);
838}
839
3ec09742
CL
840static void setup_object_debug(struct kmem_cache *s, struct page *page,
841 void *object)
842{
843 if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
844 return;
845
846 init_object(s, object, 0);
847 init_tracking(s, object);
848}
849
850static int alloc_debug_processing(struct kmem_cache *s, struct page *page,
851 void *object, void *addr)
81819f0f
CL
852{
853 if (!check_slab(s, page))
854 goto bad;
855
d692ef6d 856 if (!on_freelist(s, page, object)) {
24922684 857 object_err(s, page, object, "Object already allocated");
70d71228 858 goto bad;
81819f0f
CL
859 }
860
861 if (!check_valid_pointer(s, page, object)) {
862 object_err(s, page, object, "Freelist Pointer check fails");
70d71228 863 goto bad;
81819f0f
CL
864 }
865
d692ef6d 866 if (!check_object(s, page, object, 0))
81819f0f 867 goto bad;
81819f0f 868
3ec09742
CL
869 /* Success perform special debug activities for allocs */
870 if (s->flags & SLAB_STORE_USER)
871 set_track(s, object, TRACK_ALLOC, addr);
872 trace(s, page, object, 1);
873 init_object(s, object, 1);
81819f0f 874 return 1;
3ec09742 875
81819f0f
CL
876bad:
877 if (PageSlab(page)) {
878 /*
879 * If this is a slab page then lets do the best we can
880 * to avoid issues in the future. Marking all objects
672bba3a 881 * as used avoids touching the remaining objects.
81819f0f 882 */
24922684 883 slab_fix(s, "Marking all objects used");
81819f0f 884 page->inuse = s->objects;
a973e9dd 885 page->freelist = NULL;
81819f0f
CL
886 }
887 return 0;
888}
889
3ec09742
CL
890static int free_debug_processing(struct kmem_cache *s, struct page *page,
891 void *object, void *addr)
81819f0f
CL
892{
893 if (!check_slab(s, page))
894 goto fail;
895
896 if (!check_valid_pointer(s, page, object)) {
70d71228 897 slab_err(s, page, "Invalid object pointer 0x%p", object);
81819f0f
CL
898 goto fail;
899 }
900
901 if (on_freelist(s, page, object)) {
24922684 902 object_err(s, page, object, "Object already free");
81819f0f
CL
903 goto fail;
904 }
905
906 if (!check_object(s, page, object, 1))
907 return 0;
908
909 if (unlikely(s != page->slab)) {
3adbefee 910 if (!PageSlab(page)) {
70d71228
CL
911 slab_err(s, page, "Attempt to free object(0x%p) "
912 "outside of slab", object);
3adbefee 913 } else if (!page->slab) {
81819f0f 914 printk(KERN_ERR
70d71228 915 "SLUB <none>: no slab for object 0x%p.\n",
81819f0f 916 object);
70d71228 917 dump_stack();
06428780 918 } else
24922684
CL
919 object_err(s, page, object,
920 "page slab pointer corrupt.");
81819f0f
CL
921 goto fail;
922 }
3ec09742
CL
923
924 /* Special debug activities for freeing objects */
a973e9dd 925 if (!SlabFrozen(page) && !page->freelist)
3ec09742
CL
926 remove_full(s, page);
927 if (s->flags & SLAB_STORE_USER)
928 set_track(s, object, TRACK_FREE, addr);
929 trace(s, page, object, 0);
930 init_object(s, object, 0);
81819f0f 931 return 1;
3ec09742 932
81819f0f 933fail:
24922684 934 slab_fix(s, "Object at 0x%p not freed", object);
81819f0f
CL
935 return 0;
936}
937
41ecc55b
CL
938static int __init setup_slub_debug(char *str)
939{
f0630fff
CL
940 slub_debug = DEBUG_DEFAULT_FLAGS;
941 if (*str++ != '=' || !*str)
942 /*
943 * No options specified. Switch on full debugging.
944 */
945 goto out;
946
947 if (*str == ',')
948 /*
949 * No options but restriction on slabs. This means full
950 * debugging for slabs matching a pattern.
951 */
952 goto check_slabs;
953
954 slub_debug = 0;
955 if (*str == '-')
956 /*
957 * Switch off all debugging measures.
958 */
959 goto out;
960
961 /*
962 * Determine which debug features should be switched on
963 */
06428780 964 for (; *str && *str != ','; str++) {
f0630fff
CL
965 switch (tolower(*str)) {
966 case 'f':
967 slub_debug |= SLAB_DEBUG_FREE;
968 break;
969 case 'z':
970 slub_debug |= SLAB_RED_ZONE;
971 break;
972 case 'p':
973 slub_debug |= SLAB_POISON;
974 break;
975 case 'u':
976 slub_debug |= SLAB_STORE_USER;
977 break;
978 case 't':
979 slub_debug |= SLAB_TRACE;
980 break;
981 default:
982 printk(KERN_ERR "slub_debug option '%c' "
06428780 983 "unknown. skipped\n", *str);
f0630fff 984 }
41ecc55b
CL
985 }
986
f0630fff 987check_slabs:
41ecc55b
CL
988 if (*str == ',')
989 slub_debug_slabs = str + 1;
f0630fff 990out:
41ecc55b
CL
991 return 1;
992}
993
994__setup("slub_debug", setup_slub_debug);
995
ba0268a8
CL
996static unsigned long kmem_cache_flags(unsigned long objsize,
997 unsigned long flags, const char *name,
4ba9b9d0 998 void (*ctor)(struct kmem_cache *, void *))
41ecc55b
CL
999{
1000 /*
e153362a 1001 * Enable debugging if selected on the kernel commandline.
41ecc55b 1002 */
e153362a
CL
1003 if (slub_debug && (!slub_debug_slabs ||
1004 strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)) == 0))
1005 flags |= slub_debug;
ba0268a8
CL
1006
1007 return flags;
41ecc55b
CL
1008}
1009#else
3ec09742
CL
1010static inline void setup_object_debug(struct kmem_cache *s,
1011 struct page *page, void *object) {}
41ecc55b 1012
3ec09742
CL
1013static inline int alloc_debug_processing(struct kmem_cache *s,
1014 struct page *page, void *object, void *addr) { return 0; }
41ecc55b 1015
3ec09742
CL
1016static inline int free_debug_processing(struct kmem_cache *s,
1017 struct page *page, void *object, void *addr) { return 0; }
41ecc55b 1018
41ecc55b
CL
1019static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
1020 { return 1; }
1021static inline int check_object(struct kmem_cache *s, struct page *page,
1022 void *object, int active) { return 1; }
3ec09742 1023static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
ba0268a8
CL
1024static inline unsigned long kmem_cache_flags(unsigned long objsize,
1025 unsigned long flags, const char *name,
4ba9b9d0 1026 void (*ctor)(struct kmem_cache *, void *))
ba0268a8
CL
1027{
1028 return flags;
1029}
41ecc55b
CL
1030#define slub_debug 0
1031#endif
81819f0f
CL
1032/*
1033 * Slab allocation and freeing
1034 */
1035static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1036{
06428780 1037 struct page *page;
81819f0f
CL
1038 int pages = 1 << s->order;
1039
b7a49f0d 1040 flags |= s->allocflags;
e12ba74d 1041
81819f0f
CL
1042 if (node == -1)
1043 page = alloc_pages(flags, s->order);
1044 else
1045 page = alloc_pages_node(node, flags, s->order);
1046
1047 if (!page)
1048 return NULL;
1049
1050 mod_zone_page_state(page_zone(page),
1051 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1052 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
1053 pages);
1054
1055 return page;
1056}
1057
1058static void setup_object(struct kmem_cache *s, struct page *page,
1059 void *object)
1060{
3ec09742 1061 setup_object_debug(s, page, object);
4f104934 1062 if (unlikely(s->ctor))
4ba9b9d0 1063 s->ctor(s, object);
81819f0f
CL
1064}
1065
1066static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1067{
1068 struct page *page;
1069 struct kmem_cache_node *n;
1070 void *start;
81819f0f
CL
1071 void *last;
1072 void *p;
1073
6cb06229 1074 BUG_ON(flags & GFP_SLAB_BUG_MASK);
81819f0f 1075
6cb06229
CL
1076 page = allocate_slab(s,
1077 flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
81819f0f
CL
1078 if (!page)
1079 goto out;
1080
1081 n = get_node(s, page_to_nid(page));
1082 if (n)
1083 atomic_long_inc(&n->nr_slabs);
81819f0f
CL
1084 page->slab = s;
1085 page->flags |= 1 << PG_slab;
1086 if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
1087 SLAB_STORE_USER | SLAB_TRACE))
35e5d7ee 1088 SetSlabDebug(page);
81819f0f
CL
1089
1090 start = page_address(page);
81819f0f
CL
1091
1092 if (unlikely(s->flags & SLAB_POISON))
1093 memset(start, POISON_INUSE, PAGE_SIZE << s->order);
1094
1095 last = start;
7656c72b 1096 for_each_object(p, s, start) {
81819f0f
CL
1097 setup_object(s, page, last);
1098 set_freepointer(s, last, p);
1099 last = p;
1100 }
1101 setup_object(s, page, last);
a973e9dd 1102 set_freepointer(s, last, NULL);
81819f0f
CL
1103
1104 page->freelist = start;
1105 page->inuse = 0;
1106out:
81819f0f
CL
1107 return page;
1108}
1109
1110static void __free_slab(struct kmem_cache *s, struct page *page)
1111{
1112 int pages = 1 << s->order;
1113
c59def9f 1114 if (unlikely(SlabDebug(page))) {
81819f0f
CL
1115 void *p;
1116
1117 slab_pad_check(s, page);
a973e9dd 1118 for_each_object(p, s, page_address(page))
81819f0f 1119 check_object(s, page, p, 0);
2208b764 1120 ClearSlabDebug(page);
81819f0f
CL
1121 }
1122
1123 mod_zone_page_state(page_zone(page),
1124 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
1125 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
06428780 1126 -pages);
81819f0f 1127
81819f0f
CL
1128 __free_pages(page, s->order);
1129}
1130
1131static void rcu_free_slab(struct rcu_head *h)
1132{
1133 struct page *page;
1134
1135 page = container_of((struct list_head *)h, struct page, lru);
1136 __free_slab(page->slab, page);
1137}
1138
1139static void free_slab(struct kmem_cache *s, struct page *page)
1140{
1141 if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
1142 /*
1143 * RCU free overloads the RCU head over the LRU
1144 */
1145 struct rcu_head *head = (void *)&page->lru;
1146
1147 call_rcu(head, rcu_free_slab);
1148 } else
1149 __free_slab(s, page);
1150}
1151
1152static void discard_slab(struct kmem_cache *s, struct page *page)
1153{
1154 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1155
1156 atomic_long_dec(&n->nr_slabs);
1157 reset_page_mapcount(page);
35e5d7ee 1158 __ClearPageSlab(page);
81819f0f
CL
1159 free_slab(s, page);
1160}
1161
1162/*
1163 * Per slab locking using the pagelock
1164 */
1165static __always_inline void slab_lock(struct page *page)
1166{
1167 bit_spin_lock(PG_locked, &page->flags);
1168}
1169
1170static __always_inline void slab_unlock(struct page *page)
1171{
a76d3546 1172 __bit_spin_unlock(PG_locked, &page->flags);
81819f0f
CL
1173}
1174
1175static __always_inline int slab_trylock(struct page *page)
1176{
1177 int rc = 1;
1178
1179 rc = bit_spin_trylock(PG_locked, &page->flags);
1180 return rc;
1181}
1182
1183/*
1184 * Management of partially allocated slabs
1185 */
7c2e132c
CL
1186static void add_partial(struct kmem_cache_node *n,
1187 struct page *page, int tail)
81819f0f 1188{
e95eed57
CL
1189 spin_lock(&n->list_lock);
1190 n->nr_partial++;
7c2e132c
CL
1191 if (tail)
1192 list_add_tail(&page->lru, &n->partial);
1193 else
1194 list_add(&page->lru, &n->partial);
81819f0f
CL
1195 spin_unlock(&n->list_lock);
1196}
1197
1198static void remove_partial(struct kmem_cache *s,
1199 struct page *page)
1200{
1201 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
1202
1203 spin_lock(&n->list_lock);
1204 list_del(&page->lru);
1205 n->nr_partial--;
1206 spin_unlock(&n->list_lock);
1207}
1208
1209/*
672bba3a 1210 * Lock slab and remove from the partial list.
81819f0f 1211 *
672bba3a 1212 * Must hold list_lock.
81819f0f 1213 */
4b6f0750 1214static inline int lock_and_freeze_slab(struct kmem_cache_node *n, struct page *page)
81819f0f
CL
1215{
1216 if (slab_trylock(page)) {
1217 list_del(&page->lru);
1218 n->nr_partial--;
4b6f0750 1219 SetSlabFrozen(page);
81819f0f
CL
1220 return 1;
1221 }
1222 return 0;
1223}
1224
1225/*
672bba3a 1226 * Try to allocate a partial slab from a specific node.
81819f0f
CL
1227 */
1228static struct page *get_partial_node(struct kmem_cache_node *n)
1229{
1230 struct page *page;
1231
1232 /*
1233 * Racy check. If we mistakenly see no partial slabs then we
1234 * just allocate an empty slab. If we mistakenly try to get a
672bba3a
CL
1235 * partial slab and there is none available then get_partials()
1236 * will return NULL.
81819f0f
CL
1237 */
1238 if (!n || !n->nr_partial)
1239 return NULL;
1240
1241 spin_lock(&n->list_lock);
1242 list_for_each_entry(page, &n->partial, lru)
4b6f0750 1243 if (lock_and_freeze_slab(n, page))
81819f0f
CL
1244 goto out;
1245 page = NULL;
1246out:
1247 spin_unlock(&n->list_lock);
1248 return page;
1249}
1250
1251/*
672bba3a 1252 * Get a page from somewhere. Search in increasing NUMA distances.
81819f0f
CL
1253 */
1254static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
1255{
1256#ifdef CONFIG_NUMA
1257 struct zonelist *zonelist;
1258 struct zone **z;
1259 struct page *page;
1260
1261 /*
672bba3a
CL
1262 * The defrag ratio allows a configuration of the tradeoffs between
1263 * inter node defragmentation and node local allocations. A lower
1264 * defrag_ratio increases the tendency to do local allocations
1265 * instead of attempting to obtain partial slabs from other nodes.
81819f0f 1266 *
672bba3a
CL
1267 * If the defrag_ratio is set to 0 then kmalloc() always
1268 * returns node local objects. If the ratio is higher then kmalloc()
1269 * may return off node objects because partial slabs are obtained
1270 * from other nodes and filled up.
81819f0f 1271 *
6446faa2 1272 * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
672bba3a
CL
1273 * defrag_ratio = 1000) then every (well almost) allocation will
1274 * first attempt to defrag slab caches on other nodes. This means
1275 * scanning over all nodes to look for partial slabs which may be
1276 * expensive if we do it every time we are trying to find a slab
1277 * with available objects.
81819f0f 1278 */
9824601e
CL
1279 if (!s->remote_node_defrag_ratio ||
1280 get_cycles() % 1024 > s->remote_node_defrag_ratio)
81819f0f
CL
1281 return NULL;
1282
3adbefee
IM
1283 zonelist = &NODE_DATA(
1284 slab_node(current->mempolicy))->node_zonelists[gfp_zone(flags)];
81819f0f
CL
1285 for (z = zonelist->zones; *z; z++) {
1286 struct kmem_cache_node *n;
1287
1288 n = get_node(s, zone_to_nid(*z));
1289
1290 if (n && cpuset_zone_allowed_hardwall(*z, flags) &&
e95eed57 1291 n->nr_partial > MIN_PARTIAL) {
81819f0f
CL
1292 page = get_partial_node(n);
1293 if (page)
1294 return page;
1295 }
1296 }
1297#endif
1298 return NULL;
1299}
1300
1301/*
1302 * Get a partial page, lock it and return it.
1303 */
1304static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
1305{
1306 struct page *page;
1307 int searchnode = (node == -1) ? numa_node_id() : node;
1308
1309 page = get_partial_node(get_node(s, searchnode));
1310 if (page || (flags & __GFP_THISNODE))
1311 return page;
1312
1313 return get_any_partial(s, flags);
1314}
1315
1316/*
1317 * Move a page back to the lists.
1318 *
1319 * Must be called with the slab lock held.
1320 *
1321 * On exit the slab lock will have been dropped.
1322 */
7c2e132c 1323static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
81819f0f 1324{
e95eed57 1325 struct kmem_cache_node *n = get_node(s, page_to_nid(page));
8ff12cfc 1326 struct kmem_cache_cpu *c = get_cpu_slab(s, smp_processor_id());
e95eed57 1327
4b6f0750 1328 ClearSlabFrozen(page);
81819f0f 1329 if (page->inuse) {
e95eed57 1330
a973e9dd 1331 if (page->freelist) {
7c2e132c 1332 add_partial(n, page, tail);
8ff12cfc
CL
1333 stat(c, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
1334 } else {
1335 stat(c, DEACTIVATE_FULL);
1336 if (SlabDebug(page) && (s->flags & SLAB_STORE_USER))
1337 add_full(n, page);
1338 }
81819f0f
CL
1339 slab_unlock(page);
1340 } else {
8ff12cfc 1341 stat(c, DEACTIVATE_EMPTY);
e95eed57
CL
1342 if (n->nr_partial < MIN_PARTIAL) {
1343 /*
672bba3a
CL
1344 * Adding an empty slab to the partial slabs in order
1345 * to avoid page allocator overhead. This slab needs
1346 * to come after the other slabs with objects in
6446faa2
CL
1347 * so that the others get filled first. That way the
1348 * size of the partial list stays small.
1349 *
1350 * kmem_cache_shrink can reclaim any empty slabs from the
1351 * partial list.
e95eed57 1352 */
7c2e132c 1353 add_partial(n, page, 1);
e95eed57
CL
1354 slab_unlock(page);
1355 } else {
1356 slab_unlock(page);
8ff12cfc 1357 stat(get_cpu_slab(s, raw_smp_processor_id()), FREE_SLAB);
e95eed57
CL
1358 discard_slab(s, page);
1359 }
81819f0f
CL
1360 }
1361}
1362
1363/*
1364 * Remove the cpu slab
1365 */
dfb4f096 1366static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
81819f0f 1367{
dfb4f096 1368 struct page *page = c->page;
7c2e132c 1369 int tail = 1;
8ff12cfc 1370
b773ad73 1371 if (page->freelist)
8ff12cfc 1372 stat(c, DEACTIVATE_REMOTE_FREES);
894b8788 1373 /*
6446faa2 1374 * Merge cpu freelist into slab freelist. Typically we get here
894b8788
CL
1375 * because both freelists are empty. So this is unlikely
1376 * to occur.
1377 */
a973e9dd 1378 while (unlikely(c->freelist)) {
894b8788
CL
1379 void **object;
1380
7c2e132c
CL
1381 tail = 0; /* Hot objects. Put the slab first */
1382
894b8788 1383 /* Retrieve object from cpu_freelist */
dfb4f096 1384 object = c->freelist;
b3fba8da 1385 c->freelist = c->freelist[c->offset];
894b8788
CL
1386
1387 /* And put onto the regular freelist */
b3fba8da 1388 object[c->offset] = page->freelist;
894b8788
CL
1389 page->freelist = object;
1390 page->inuse--;
1391 }
dfb4f096 1392 c->page = NULL;
7c2e132c 1393 unfreeze_slab(s, page, tail);
81819f0f
CL
1394}
1395
dfb4f096 1396static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
81819f0f 1397{
8ff12cfc 1398 stat(c, CPUSLAB_FLUSH);
dfb4f096
CL
1399 slab_lock(c->page);
1400 deactivate_slab(s, c);
81819f0f
CL
1401}
1402
1403/*
1404 * Flush cpu slab.
6446faa2 1405 *
81819f0f
CL
1406 * Called from IPI handler with interrupts disabled.
1407 */
0c710013 1408static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
81819f0f 1409{
dfb4f096 1410 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
81819f0f 1411
dfb4f096
CL
1412 if (likely(c && c->page))
1413 flush_slab(s, c);
81819f0f
CL
1414}
1415
1416static void flush_cpu_slab(void *d)
1417{
1418 struct kmem_cache *s = d;
81819f0f 1419
dfb4f096 1420 __flush_cpu_slab(s, smp_processor_id());
81819f0f
CL
1421}
1422
1423static void flush_all(struct kmem_cache *s)
1424{
1425#ifdef CONFIG_SMP
1426 on_each_cpu(flush_cpu_slab, s, 1, 1);
1427#else
1428 unsigned long flags;
1429
1430 local_irq_save(flags);
1431 flush_cpu_slab(s);
1432 local_irq_restore(flags);
1433#endif
1434}
1435
dfb4f096
CL
1436/*
1437 * Check if the objects in a per cpu structure fit numa
1438 * locality expectations.
1439 */
1440static inline int node_match(struct kmem_cache_cpu *c, int node)
1441{
1442#ifdef CONFIG_NUMA
1443 if (node != -1 && c->node != node)
1444 return 0;
1445#endif
1446 return 1;
1447}
1448
81819f0f 1449/*
894b8788
CL
1450 * Slow path. The lockless freelist is empty or we need to perform
1451 * debugging duties.
1452 *
1453 * Interrupts are disabled.
81819f0f 1454 *
894b8788
CL
1455 * Processing is still very fast if new objects have been freed to the
1456 * regular freelist. In that case we simply take over the regular freelist
1457 * as the lockless freelist and zap the regular freelist.
81819f0f 1458 *
894b8788
CL
1459 * If that is not working then we fall back to the partial lists. We take the
1460 * first element of the freelist as the object to allocate now and move the
1461 * rest of the freelist to the lockless freelist.
81819f0f 1462 *
894b8788 1463 * And if we were unable to get a new slab from the partial slab lists then
6446faa2
CL
1464 * we need to allocate a new slab. This is the slowest path since it involves
1465 * a call to the page allocator and the setup of a new slab.
81819f0f 1466 */
894b8788 1467static void *__slab_alloc(struct kmem_cache *s,
dfb4f096 1468 gfp_t gfpflags, int node, void *addr, struct kmem_cache_cpu *c)
81819f0f 1469{
81819f0f 1470 void **object;
dfb4f096 1471 struct page *new;
81819f0f 1472
dfb4f096 1473 if (!c->page)
81819f0f
CL
1474 goto new_slab;
1475
dfb4f096
CL
1476 slab_lock(c->page);
1477 if (unlikely(!node_match(c, node)))
81819f0f 1478 goto another_slab;
6446faa2 1479
8ff12cfc 1480 stat(c, ALLOC_REFILL);
6446faa2 1481
894b8788 1482load_freelist:
dfb4f096 1483 object = c->page->freelist;
a973e9dd 1484 if (unlikely(!object))
81819f0f 1485 goto another_slab;
dfb4f096 1486 if (unlikely(SlabDebug(c->page)))
81819f0f
CL
1487 goto debug;
1488
b3fba8da 1489 c->freelist = object[c->offset];
dfb4f096 1490 c->page->inuse = s->objects;
a973e9dd 1491 c->page->freelist = NULL;
dfb4f096 1492 c->node = page_to_nid(c->page);
1f84260c 1493unlock_out:
dfb4f096 1494 slab_unlock(c->page);
8ff12cfc 1495 stat(c, ALLOC_SLOWPATH);
81819f0f
CL
1496 return object;
1497
1498another_slab:
dfb4f096 1499 deactivate_slab(s, c);
81819f0f
CL
1500
1501new_slab:
dfb4f096
CL
1502 new = get_partial(s, gfpflags, node);
1503 if (new) {
1504 c->page = new;
8ff12cfc 1505 stat(c, ALLOC_FROM_PARTIAL);
894b8788 1506 goto load_freelist;
81819f0f
CL
1507 }
1508
b811c202
CL
1509 if (gfpflags & __GFP_WAIT)
1510 local_irq_enable();
1511
dfb4f096 1512 new = new_slab(s, gfpflags, node);
b811c202
CL
1513
1514 if (gfpflags & __GFP_WAIT)
1515 local_irq_disable();
1516
dfb4f096
CL
1517 if (new) {
1518 c = get_cpu_slab(s, smp_processor_id());
8ff12cfc 1519 stat(c, ALLOC_SLAB);
05aa3450 1520 if (c->page)
dfb4f096 1521 flush_slab(s, c);
dfb4f096
CL
1522 slab_lock(new);
1523 SetSlabFrozen(new);
1524 c->page = new;
4b6f0750 1525 goto load_freelist;
81819f0f 1526 }
00e962c5 1527
71c7a06f
CL
1528 /*
1529 * No memory available.
1530 *
1531 * If the slab uses higher order allocs but the object is
1532 * smaller than a page size then we can fallback in emergencies
1533 * to the page allocator via kmalloc_large. The page allocator may
1534 * have failed to obtain a higher order page and we can try to
1535 * allocate a single page if the object fits into a single page.
1536 * That is only possible if certain conditions are met that are being
1537 * checked when a slab is created.
1538 */
caeab084
CL
1539 if (!(gfpflags & __GFP_NORETRY) &&
1540 (s->flags & __PAGE_ALLOC_FALLBACK)) {
1541 if (gfpflags & __GFP_WAIT)
1542 local_irq_enable();
1543 object = kmalloc_large(s->objsize, gfpflags);
1544 if (gfpflags & __GFP_WAIT)
1545 local_irq_disable();
1546 return object;
1547 }
71c7a06f 1548 return NULL;
81819f0f 1549debug:
dfb4f096 1550 if (!alloc_debug_processing(s, c->page, object, addr))
81819f0f 1551 goto another_slab;
894b8788 1552
dfb4f096 1553 c->page->inuse++;
b3fba8da 1554 c->page->freelist = object[c->offset];
ee3c72a1 1555 c->node = -1;
1f84260c 1556 goto unlock_out;
894b8788
CL
1557}
1558
1559/*
1560 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
1561 * have the fastpath folded into their functions. So no function call
1562 * overhead for requests that can be satisfied on the fastpath.
1563 *
1564 * The fastpath works by first checking if the lockless freelist can be used.
1565 * If not then __slab_alloc is called for slow processing.
1566 *
1567 * Otherwise we can simply pick the next object from the lockless free list.
1568 */
06428780 1569static __always_inline void *slab_alloc(struct kmem_cache *s,
ce15fea8 1570 gfp_t gfpflags, int node, void *addr)
894b8788 1571{
894b8788 1572 void **object;
dfb4f096 1573 struct kmem_cache_cpu *c;
1f84260c
CL
1574 unsigned long flags;
1575
894b8788 1576 local_irq_save(flags);
dfb4f096 1577 c = get_cpu_slab(s, smp_processor_id());
a973e9dd 1578 if (unlikely(!c->freelist || !node_match(c, node)))
894b8788 1579
dfb4f096 1580 object = __slab_alloc(s, gfpflags, node, addr, c);
894b8788
CL
1581
1582 else {
dfb4f096 1583 object = c->freelist;
b3fba8da 1584 c->freelist = object[c->offset];
8ff12cfc 1585 stat(c, ALLOC_FASTPATH);
894b8788
CL
1586 }
1587 local_irq_restore(flags);
d07dbea4
CL
1588
1589 if (unlikely((gfpflags & __GFP_ZERO) && object))
42a9fdbb 1590 memset(object, 0, c->objsize);
d07dbea4 1591
894b8788 1592 return object;
81819f0f
CL
1593}
1594
1595void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
1596{
ce15fea8 1597 return slab_alloc(s, gfpflags, -1, __builtin_return_address(0));
81819f0f
CL
1598}
1599EXPORT_SYMBOL(kmem_cache_alloc);
1600
1601#ifdef CONFIG_NUMA
1602void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
1603{
ce15fea8 1604 return slab_alloc(s, gfpflags, node, __builtin_return_address(0));
81819f0f
CL
1605}
1606EXPORT_SYMBOL(kmem_cache_alloc_node);
1607#endif
1608
1609/*
894b8788
CL
1610 * Slow patch handling. This may still be called frequently since objects
1611 * have a longer lifetime than the cpu slabs in most processing loads.
81819f0f 1612 *
894b8788
CL
1613 * So we still attempt to reduce cache line usage. Just take the slab
1614 * lock and free the item. If there is no additional partial page
1615 * handling required then we can return immediately.
81819f0f 1616 */
894b8788 1617static void __slab_free(struct kmem_cache *s, struct page *page,
b3fba8da 1618 void *x, void *addr, unsigned int offset)
81819f0f
CL
1619{
1620 void *prior;
1621 void **object = (void *)x;
8ff12cfc 1622 struct kmem_cache_cpu *c;
81819f0f 1623
8ff12cfc
CL
1624 c = get_cpu_slab(s, raw_smp_processor_id());
1625 stat(c, FREE_SLOWPATH);
81819f0f
CL
1626 slab_lock(page);
1627
35e5d7ee 1628 if (unlikely(SlabDebug(page)))
81819f0f 1629 goto debug;
6446faa2 1630
81819f0f 1631checks_ok:
b3fba8da 1632 prior = object[offset] = page->freelist;
81819f0f
CL
1633 page->freelist = object;
1634 page->inuse--;
1635
8ff12cfc
CL
1636 if (unlikely(SlabFrozen(page))) {
1637 stat(c, FREE_FROZEN);
81819f0f 1638 goto out_unlock;
8ff12cfc 1639 }
81819f0f
CL
1640
1641 if (unlikely(!page->inuse))
1642 goto slab_empty;
1643
1644 /*
6446faa2 1645 * Objects left in the slab. If it was not on the partial list before
81819f0f
CL
1646 * then add it.
1647 */
a973e9dd 1648 if (unlikely(!prior)) {
7c2e132c 1649 add_partial(get_node(s, page_to_nid(page)), page, 1);
8ff12cfc
CL
1650 stat(c, FREE_ADD_PARTIAL);
1651 }
81819f0f
CL
1652
1653out_unlock:
1654 slab_unlock(page);
81819f0f
CL
1655 return;
1656
1657slab_empty:
a973e9dd 1658 if (prior) {
81819f0f 1659 /*
672bba3a 1660 * Slab still on the partial list.
81819f0f
CL
1661 */
1662 remove_partial(s, page);
8ff12cfc
CL
1663 stat(c, FREE_REMOVE_PARTIAL);
1664 }
81819f0f 1665 slab_unlock(page);
8ff12cfc 1666 stat(c, FREE_SLAB);
81819f0f 1667 discard_slab(s, page);
81819f0f
CL
1668 return;
1669
1670debug:
3ec09742 1671 if (!free_debug_processing(s, page, x, addr))
77c5e2d0 1672 goto out_unlock;
77c5e2d0 1673 goto checks_ok;
81819f0f
CL
1674}
1675
894b8788
CL
1676/*
1677 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
1678 * can perform fastpath freeing without additional function calls.
1679 *
1680 * The fastpath is only possible if we are freeing to the current cpu slab
1681 * of this processor. This typically the case if we have just allocated
1682 * the item before.
1683 *
1684 * If fastpath is not possible then fall back to __slab_free where we deal
1685 * with all sorts of special processing.
1686 */
06428780 1687static __always_inline void slab_free(struct kmem_cache *s,
894b8788
CL
1688 struct page *page, void *x, void *addr)
1689{
1690 void **object = (void *)x;
dfb4f096 1691 struct kmem_cache_cpu *c;
1f84260c
CL
1692 unsigned long flags;
1693
894b8788 1694 local_irq_save(flags);
dfb4f096 1695 c = get_cpu_slab(s, smp_processor_id());
27d9e4e9 1696 debug_check_no_locks_freed(object, c->objsize);
ee3c72a1 1697 if (likely(page == c->page && c->node >= 0)) {
b3fba8da 1698 object[c->offset] = c->freelist;
dfb4f096 1699 c->freelist = object;
8ff12cfc 1700 stat(c, FREE_FASTPATH);
894b8788 1701 } else
b3fba8da 1702 __slab_free(s, page, x, addr, c->offset);
894b8788
CL
1703
1704 local_irq_restore(flags);
1705}
1706
81819f0f
CL
1707void kmem_cache_free(struct kmem_cache *s, void *x)
1708{
77c5e2d0 1709 struct page *page;
81819f0f 1710
b49af68f 1711 page = virt_to_head_page(x);
81819f0f 1712
77c5e2d0 1713 slab_free(s, page, x, __builtin_return_address(0));
81819f0f
CL
1714}
1715EXPORT_SYMBOL(kmem_cache_free);
1716
1717/* Figure out on which slab object the object resides */
1718static struct page *get_object_page(const void *x)
1719{
b49af68f 1720 struct page *page = virt_to_head_page(x);
81819f0f
CL
1721
1722 if (!PageSlab(page))
1723 return NULL;
1724
1725 return page;
1726}
1727
1728/*
672bba3a
CL
1729 * Object placement in a slab is made very easy because we always start at
1730 * offset 0. If we tune the size of the object to the alignment then we can
1731 * get the required alignment by putting one properly sized object after
1732 * another.
81819f0f
CL
1733 *
1734 * Notice that the allocation order determines the sizes of the per cpu
1735 * caches. Each processor has always one slab available for allocations.
1736 * Increasing the allocation order reduces the number of times that slabs
672bba3a 1737 * must be moved on and off the partial lists and is therefore a factor in
81819f0f 1738 * locking overhead.
81819f0f
CL
1739 */
1740
1741/*
1742 * Mininum / Maximum order of slab pages. This influences locking overhead
1743 * and slab fragmentation. A higher order reduces the number of partial slabs
1744 * and increases the number of allocations possible without having to
1745 * take the list_lock.
1746 */
1747static int slub_min_order;
1748static int slub_max_order = DEFAULT_MAX_ORDER;
81819f0f
CL
1749static int slub_min_objects = DEFAULT_MIN_OBJECTS;
1750
1751/*
1752 * Merge control. If this is set then no merging of slab caches will occur.
672bba3a 1753 * (Could be removed. This was introduced to pacify the merge skeptics.)
81819f0f
CL
1754 */
1755static int slub_nomerge;
1756
81819f0f
CL
1757/*
1758 * Calculate the order of allocation given an slab object size.
1759 *
672bba3a
CL
1760 * The order of allocation has significant impact on performance and other
1761 * system components. Generally order 0 allocations should be preferred since
1762 * order 0 does not cause fragmentation in the page allocator. Larger objects
1763 * be problematic to put into order 0 slabs because there may be too much
1764 * unused space left. We go to a higher order if more than 1/8th of the slab
1765 * would be wasted.
1766 *
1767 * In order to reach satisfactory performance we must ensure that a minimum
1768 * number of objects is in one slab. Otherwise we may generate too much
1769 * activity on the partial lists which requires taking the list_lock. This is
1770 * less a concern for large slabs though which are rarely used.
81819f0f 1771 *
672bba3a
CL
1772 * slub_max_order specifies the order where we begin to stop considering the
1773 * number of objects in a slab as critical. If we reach slub_max_order then
1774 * we try to keep the page order as low as possible. So we accept more waste
1775 * of space in favor of a small page order.
81819f0f 1776 *
672bba3a
CL
1777 * Higher order allocations also allow the placement of more objects in a
1778 * slab and thereby reduce object handling overhead. If the user has
1779 * requested a higher mininum order then we start with that one instead of
1780 * the smallest order which will fit the object.
81819f0f 1781 */
5e6d444e
CL
1782static inline int slab_order(int size, int min_objects,
1783 int max_order, int fract_leftover)
81819f0f
CL
1784{
1785 int order;
1786 int rem;
6300ea75 1787 int min_order = slub_min_order;
81819f0f 1788
6300ea75 1789 for (order = max(min_order,
5e6d444e
CL
1790 fls(min_objects * size - 1) - PAGE_SHIFT);
1791 order <= max_order; order++) {
81819f0f 1792
5e6d444e 1793 unsigned long slab_size = PAGE_SIZE << order;
81819f0f 1794
5e6d444e 1795 if (slab_size < min_objects * size)
81819f0f
CL
1796 continue;
1797
1798 rem = slab_size % size;
1799
5e6d444e 1800 if (rem <= slab_size / fract_leftover)
81819f0f
CL
1801 break;
1802
1803 }
672bba3a 1804
81819f0f
CL
1805 return order;
1806}
1807
5e6d444e
CL
1808static inline int calculate_order(int size)
1809{
1810 int order;
1811 int min_objects;
1812 int fraction;
1813
1814 /*
1815 * Attempt to find best configuration for a slab. This
1816 * works by first attempting to generate a layout with
1817 * the best configuration and backing off gradually.
1818 *
1819 * First we reduce the acceptable waste in a slab. Then
1820 * we reduce the minimum objects required in a slab.
1821 */
1822 min_objects = slub_min_objects;
1823 while (min_objects > 1) {
1824 fraction = 8;
1825 while (fraction >= 4) {
1826 order = slab_order(size, min_objects,
1827 slub_max_order, fraction);
1828 if (order <= slub_max_order)
1829 return order;
1830 fraction /= 2;
1831 }
1832 min_objects /= 2;
1833 }
1834
1835 /*
1836 * We were unable to place multiple objects in a slab. Now
1837 * lets see if we can place a single object there.
1838 */
1839 order = slab_order(size, 1, slub_max_order, 1);
1840 if (order <= slub_max_order)
1841 return order;
1842
1843 /*
1844 * Doh this slab cannot be placed using slub_max_order.
1845 */
1846 order = slab_order(size, 1, MAX_ORDER, 1);
1847 if (order <= MAX_ORDER)
1848 return order;
1849 return -ENOSYS;
1850}
1851
81819f0f 1852/*
672bba3a 1853 * Figure out what the alignment of the objects will be.
81819f0f
CL
1854 */
1855static unsigned long calculate_alignment(unsigned long flags,
1856 unsigned long align, unsigned long size)
1857{
1858 /*
6446faa2
CL
1859 * If the user wants hardware cache aligned objects then follow that
1860 * suggestion if the object is sufficiently large.
81819f0f 1861 *
6446faa2
CL
1862 * The hardware cache alignment cannot override the specified
1863 * alignment though. If that is greater then use it.
81819f0f 1864 */
b6210386
NP
1865 if (flags & SLAB_HWCACHE_ALIGN) {
1866 unsigned long ralign = cache_line_size();
1867 while (size <= ralign / 2)
1868 ralign /= 2;
1869 align = max(align, ralign);
1870 }
81819f0f
CL
1871
1872 if (align < ARCH_SLAB_MINALIGN)
b6210386 1873 align = ARCH_SLAB_MINALIGN;
81819f0f
CL
1874
1875 return ALIGN(align, sizeof(void *));
1876}
1877
dfb4f096
CL
1878static void init_kmem_cache_cpu(struct kmem_cache *s,
1879 struct kmem_cache_cpu *c)
1880{
1881 c->page = NULL;
a973e9dd 1882 c->freelist = NULL;
dfb4f096 1883 c->node = 0;
42a9fdbb
CL
1884 c->offset = s->offset / sizeof(void *);
1885 c->objsize = s->objsize;
dfb4f096
CL
1886}
1887
81819f0f
CL
1888static void init_kmem_cache_node(struct kmem_cache_node *n)
1889{
1890 n->nr_partial = 0;
1891 atomic_long_set(&n->nr_slabs, 0);
1892 spin_lock_init(&n->list_lock);
1893 INIT_LIST_HEAD(&n->partial);
8ab1372f 1894#ifdef CONFIG_SLUB_DEBUG
643b1138 1895 INIT_LIST_HEAD(&n->full);
8ab1372f 1896#endif
81819f0f
CL
1897}
1898
4c93c355
CL
1899#ifdef CONFIG_SMP
1900/*
1901 * Per cpu array for per cpu structures.
1902 *
1903 * The per cpu array places all kmem_cache_cpu structures from one processor
1904 * close together meaning that it becomes possible that multiple per cpu
1905 * structures are contained in one cacheline. This may be particularly
1906 * beneficial for the kmalloc caches.
1907 *
1908 * A desktop system typically has around 60-80 slabs. With 100 here we are
1909 * likely able to get per cpu structures for all caches from the array defined
1910 * here. We must be able to cover all kmalloc caches during bootstrap.
1911 *
1912 * If the per cpu array is exhausted then fall back to kmalloc
1913 * of individual cachelines. No sharing is possible then.
1914 */
1915#define NR_KMEM_CACHE_CPU 100
1916
1917static DEFINE_PER_CPU(struct kmem_cache_cpu,
1918 kmem_cache_cpu)[NR_KMEM_CACHE_CPU];
1919
1920static DEFINE_PER_CPU(struct kmem_cache_cpu *, kmem_cache_cpu_free);
1921static cpumask_t kmem_cach_cpu_free_init_once = CPU_MASK_NONE;
1922
1923static struct kmem_cache_cpu *alloc_kmem_cache_cpu(struct kmem_cache *s,
1924 int cpu, gfp_t flags)
1925{
1926 struct kmem_cache_cpu *c = per_cpu(kmem_cache_cpu_free, cpu);
1927
1928 if (c)
1929 per_cpu(kmem_cache_cpu_free, cpu) =
1930 (void *)c->freelist;
1931 else {
1932 /* Table overflow: So allocate ourselves */
1933 c = kmalloc_node(
1934 ALIGN(sizeof(struct kmem_cache_cpu), cache_line_size()),
1935 flags, cpu_to_node(cpu));
1936 if (!c)
1937 return NULL;
1938 }
1939
1940 init_kmem_cache_cpu(s, c);
1941 return c;
1942}
1943
1944static void free_kmem_cache_cpu(struct kmem_cache_cpu *c, int cpu)
1945{
1946 if (c < per_cpu(kmem_cache_cpu, cpu) ||
1947 c > per_cpu(kmem_cache_cpu, cpu) + NR_KMEM_CACHE_CPU) {
1948 kfree(c);
1949 return;
1950 }
1951 c->freelist = (void *)per_cpu(kmem_cache_cpu_free, cpu);
1952 per_cpu(kmem_cache_cpu_free, cpu) = c;
1953}
1954
1955static void free_kmem_cache_cpus(struct kmem_cache *s)
1956{
1957 int cpu;
1958
1959 for_each_online_cpu(cpu) {
1960 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
1961
1962 if (c) {
1963 s->cpu_slab[cpu] = NULL;
1964 free_kmem_cache_cpu(c, cpu);
1965 }
1966 }
1967}
1968
1969static int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
1970{
1971 int cpu;
1972
1973 for_each_online_cpu(cpu) {
1974 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
1975
1976 if (c)
1977 continue;
1978
1979 c = alloc_kmem_cache_cpu(s, cpu, flags);
1980 if (!c) {
1981 free_kmem_cache_cpus(s);
1982 return 0;
1983 }
1984 s->cpu_slab[cpu] = c;
1985 }
1986 return 1;
1987}
1988
1989/*
1990 * Initialize the per cpu array.
1991 */
1992static void init_alloc_cpu_cpu(int cpu)
1993{
1994 int i;
1995
1996 if (cpu_isset(cpu, kmem_cach_cpu_free_init_once))
1997 return;
1998
1999 for (i = NR_KMEM_CACHE_CPU - 1; i >= 0; i--)
2000 free_kmem_cache_cpu(&per_cpu(kmem_cache_cpu, cpu)[i], cpu);
2001
2002 cpu_set(cpu, kmem_cach_cpu_free_init_once);
2003}
2004
2005static void __init init_alloc_cpu(void)
2006{
2007 int cpu;
2008
2009 for_each_online_cpu(cpu)
2010 init_alloc_cpu_cpu(cpu);
2011 }
2012
2013#else
2014static inline void free_kmem_cache_cpus(struct kmem_cache *s) {}
2015static inline void init_alloc_cpu(void) {}
2016
2017static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags)
2018{
2019 init_kmem_cache_cpu(s, &s->cpu_slab);
2020 return 1;
2021}
2022#endif
2023
81819f0f
CL
2024#ifdef CONFIG_NUMA
2025/*
2026 * No kmalloc_node yet so do it by hand. We know that this is the first
2027 * slab on the node for this slabcache. There are no concurrent accesses
2028 * possible.
2029 *
2030 * Note that this function only works on the kmalloc_node_cache
4c93c355
CL
2031 * when allocating for the kmalloc_node_cache. This is used for bootstrapping
2032 * memory on a fresh node that has no slab structures yet.
81819f0f 2033 */
1cd7daa5
AB
2034static struct kmem_cache_node *early_kmem_cache_node_alloc(gfp_t gfpflags,
2035 int node)
81819f0f
CL
2036{
2037 struct page *page;
2038 struct kmem_cache_node *n;
ba84c73c 2039 unsigned long flags;
81819f0f
CL
2040
2041 BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node));
2042
a2f92ee7 2043 page = new_slab(kmalloc_caches, gfpflags, node);
81819f0f
CL
2044
2045 BUG_ON(!page);
a2f92ee7
CL
2046 if (page_to_nid(page) != node) {
2047 printk(KERN_ERR "SLUB: Unable to allocate memory from "
2048 "node %d\n", node);
2049 printk(KERN_ERR "SLUB: Allocating a useless per node structure "
2050 "in order to be able to continue\n");
2051 }
2052
81819f0f
CL
2053 n = page->freelist;
2054 BUG_ON(!n);
2055 page->freelist = get_freepointer(kmalloc_caches, n);
2056 page->inuse++;
2057 kmalloc_caches->node[node] = n;
8ab1372f 2058#ifdef CONFIG_SLUB_DEBUG
d45f39cb
CL
2059 init_object(kmalloc_caches, n, 1);
2060 init_tracking(kmalloc_caches, n);
8ab1372f 2061#endif
81819f0f
CL
2062 init_kmem_cache_node(n);
2063 atomic_long_inc(&n->nr_slabs);
6446faa2 2064
ba84c73c 2065 /*
2066 * lockdep requires consistent irq usage for each lock
2067 * so even though there cannot be a race this early in
2068 * the boot sequence, we still disable irqs.
2069 */
2070 local_irq_save(flags);
7c2e132c 2071 add_partial(n, page, 0);
ba84c73c 2072 local_irq_restore(flags);
81819f0f
CL
2073 return n;
2074}
2075
2076static void free_kmem_cache_nodes(struct kmem_cache *s)
2077{
2078 int node;
2079
f64dc58c 2080 for_each_node_state(node, N_NORMAL_MEMORY) {
81819f0f
CL
2081 struct kmem_cache_node *n = s->node[node];
2082 if (n && n != &s->local_node)
2083 kmem_cache_free(kmalloc_caches, n);
2084 s->node[node] = NULL;
2085 }
2086}
2087
2088static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2089{
2090 int node;
2091 int local_node;
2092
2093 if (slab_state >= UP)
2094 local_node = page_to_nid(virt_to_page(s));
2095 else
2096 local_node = 0;
2097
f64dc58c 2098 for_each_node_state(node, N_NORMAL_MEMORY) {
81819f0f
CL
2099 struct kmem_cache_node *n;
2100
2101 if (local_node == node)
2102 n = &s->local_node;
2103 else {
2104 if (slab_state == DOWN) {
2105 n = early_kmem_cache_node_alloc(gfpflags,
2106 node);
2107 continue;
2108 }
2109 n = kmem_cache_alloc_node(kmalloc_caches,
2110 gfpflags, node);
2111
2112 if (!n) {
2113 free_kmem_cache_nodes(s);
2114 return 0;
2115 }
2116
2117 }
2118 s->node[node] = n;
2119 init_kmem_cache_node(n);
2120 }
2121 return 1;
2122}
2123#else
2124static void free_kmem_cache_nodes(struct kmem_cache *s)
2125{
2126}
2127
2128static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
2129{
2130 init_kmem_cache_node(&s->local_node);
2131 return 1;
2132}
2133#endif
2134
2135/*
2136 * calculate_sizes() determines the order and the distribution of data within
2137 * a slab object.
2138 */
2139static int calculate_sizes(struct kmem_cache *s)
2140{
2141 unsigned long flags = s->flags;
2142 unsigned long size = s->objsize;
2143 unsigned long align = s->align;
2144
d8b42bf5
CL
2145 /*
2146 * Round up object size to the next word boundary. We can only
2147 * place the free pointer at word boundaries and this determines
2148 * the possible location of the free pointer.
2149 */
2150 size = ALIGN(size, sizeof(void *));
2151
2152#ifdef CONFIG_SLUB_DEBUG
81819f0f
CL
2153 /*
2154 * Determine if we can poison the object itself. If the user of
2155 * the slab may touch the object after free or before allocation
2156 * then we should never poison the object itself.
2157 */
2158 if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
c59def9f 2159 !s->ctor)
81819f0f
CL
2160 s->flags |= __OBJECT_POISON;
2161 else
2162 s->flags &= ~__OBJECT_POISON;
2163
81819f0f
CL
2164
2165 /*
672bba3a 2166 * If we are Redzoning then check if there is some space between the
81819f0f 2167 * end of the object and the free pointer. If not then add an
672bba3a 2168 * additional word to have some bytes to store Redzone information.
81819f0f
CL
2169 */
2170 if ((flags & SLAB_RED_ZONE) && size == s->objsize)
2171 size += sizeof(void *);
41ecc55b 2172#endif
81819f0f
CL
2173
2174 /*
672bba3a
CL
2175 * With that we have determined the number of bytes in actual use
2176 * by the object. This is the potential offset to the free pointer.
81819f0f
CL
2177 */
2178 s->inuse = size;
2179
2180 if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
c59def9f 2181 s->ctor)) {
81819f0f
CL
2182 /*
2183 * Relocate free pointer after the object if it is not
2184 * permitted to overwrite the first word of the object on
2185 * kmem_cache_free.
2186 *
2187 * This is the case if we do RCU, have a constructor or
2188 * destructor or are poisoning the objects.
2189 */
2190 s->offset = size;
2191 size += sizeof(void *);
2192 }
2193
c12b3c62 2194#ifdef CONFIG_SLUB_DEBUG
81819f0f
CL
2195 if (flags & SLAB_STORE_USER)
2196 /*
2197 * Need to store information about allocs and frees after
2198 * the object.
2199 */
2200 size += 2 * sizeof(struct track);
2201
be7b3fbc 2202 if (flags & SLAB_RED_ZONE)
81819f0f
CL
2203 /*
2204 * Add some empty padding so that we can catch
2205 * overwrites from earlier objects rather than let
2206 * tracking information or the free pointer be
2207 * corrupted if an user writes before the start
2208 * of the object.
2209 */
2210 size += sizeof(void *);
41ecc55b 2211#endif
672bba3a 2212
81819f0f
CL
2213 /*
2214 * Determine the alignment based on various parameters that the
65c02d4c
CL
2215 * user specified and the dynamic determination of cache line size
2216 * on bootup.
81819f0f
CL
2217 */
2218 align = calculate_alignment(flags, align, s->objsize);
2219
2220 /*
2221 * SLUB stores one object immediately after another beginning from
2222 * offset 0. In order to align the objects we have to simply size
2223 * each object to conform to the alignment.
2224 */
2225 size = ALIGN(size, align);
2226 s->size = size;
2227
71c7a06f
CL
2228 if ((flags & __KMALLOC_CACHE) &&
2229 PAGE_SIZE / size < slub_min_objects) {
2230 /*
2231 * Kmalloc cache that would not have enough objects in
2232 * an order 0 page. Kmalloc slabs can fallback to
2233 * page allocator order 0 allocs so take a reasonably large
2234 * order that will allows us a good number of objects.
2235 */
2236 s->order = max(slub_max_order, PAGE_ALLOC_COSTLY_ORDER);
2237 s->flags |= __PAGE_ALLOC_FALLBACK;
2238 s->allocflags |= __GFP_NOWARN;
2239 } else
2240 s->order = calculate_order(size);
2241
81819f0f
CL
2242 if (s->order < 0)
2243 return 0;
2244
b7a49f0d
CL
2245 s->allocflags = 0;
2246 if (s->order)
2247 s->allocflags |= __GFP_COMP;
2248
2249 if (s->flags & SLAB_CACHE_DMA)
2250 s->allocflags |= SLUB_DMA;
2251
2252 if (s->flags & SLAB_RECLAIM_ACCOUNT)
2253 s->allocflags |= __GFP_RECLAIMABLE;
2254
81819f0f
CL
2255 /*
2256 * Determine the number of objects per slab
2257 */
2258 s->objects = (PAGE_SIZE << s->order) / size;
2259
b3fba8da 2260 return !!s->objects;
81819f0f
CL
2261
2262}
2263
81819f0f
CL
2264static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
2265 const char *name, size_t size,
2266 size_t align, unsigned long flags,
4ba9b9d0 2267 void (*ctor)(struct kmem_cache *, void *))
81819f0f
CL
2268{
2269 memset(s, 0, kmem_size);
2270 s->name = name;
2271 s->ctor = ctor;
81819f0f 2272 s->objsize = size;
81819f0f 2273 s->align = align;
ba0268a8 2274 s->flags = kmem_cache_flags(size, flags, name, ctor);
81819f0f
CL
2275
2276 if (!calculate_sizes(s))
2277 goto error;
2278
2279 s->refcount = 1;
2280#ifdef CONFIG_NUMA
9824601e 2281 s->remote_node_defrag_ratio = 100;
81819f0f 2282#endif
dfb4f096
CL
2283 if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA))
2284 goto error;
81819f0f 2285
dfb4f096 2286 if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA))
81819f0f 2287 return 1;
4c93c355 2288 free_kmem_cache_nodes(s);
81819f0f
CL
2289error:
2290 if (flags & SLAB_PANIC)
2291 panic("Cannot create slab %s size=%lu realsize=%u "
2292 "order=%u offset=%u flags=%lx\n",
2293 s->name, (unsigned long)size, s->size, s->order,
2294 s->offset, flags);
2295 return 0;
2296}
81819f0f
CL
2297
2298/*
2299 * Check if a given pointer is valid
2300 */
2301int kmem_ptr_validate(struct kmem_cache *s, const void *object)
2302{
06428780 2303 struct page *page;
81819f0f
CL
2304
2305 page = get_object_page(object);
2306
2307 if (!page || s != page->slab)
2308 /* No slab or wrong slab */
2309 return 0;
2310
abcd08a6 2311 if (!check_valid_pointer(s, page, object))
81819f0f
CL
2312 return 0;
2313
2314 /*
2315 * We could also check if the object is on the slabs freelist.
2316 * But this would be too expensive and it seems that the main
6446faa2 2317 * purpose of kmem_ptr_valid() is to check if the object belongs
81819f0f
CL
2318 * to a certain slab.
2319 */
2320 return 1;
2321}
2322EXPORT_SYMBOL(kmem_ptr_validate);
2323
2324/*
2325 * Determine the size of a slab object
2326 */
2327unsigned int kmem_cache_size(struct kmem_cache *s)
2328{
2329 return s->objsize;
2330}
2331EXPORT_SYMBOL(kmem_cache_size);
2332
2333const char *kmem_cache_name(struct kmem_cache *s)
2334{
2335 return s->name;
2336}
2337EXPORT_SYMBOL(kmem_cache_name);
2338
2339/*
672bba3a
CL
2340 * Attempt to free all slabs on a node. Return the number of slabs we
2341 * were unable to free.
81819f0f
CL
2342 */
2343static int free_list(struct kmem_cache *s, struct kmem_cache_node *n,
2344 struct list_head *list)
2345{
2346 int slabs_inuse = 0;
2347 unsigned long flags;
2348 struct page *page, *h;
2349
2350 spin_lock_irqsave(&n->list_lock, flags);
2351 list_for_each_entry_safe(page, h, list, lru)
2352 if (!page->inuse) {
2353 list_del(&page->lru);
2354 discard_slab(s, page);
2355 } else
2356 slabs_inuse++;
2357 spin_unlock_irqrestore(&n->list_lock, flags);
2358 return slabs_inuse;
2359}
2360
2361/*
672bba3a 2362 * Release all resources used by a slab cache.
81819f0f 2363 */
0c710013 2364static inline int kmem_cache_close(struct kmem_cache *s)
81819f0f
CL
2365{
2366 int node;
2367
2368 flush_all(s);
2369
2370 /* Attempt to free all objects */
4c93c355 2371 free_kmem_cache_cpus(s);
f64dc58c 2372 for_each_node_state(node, N_NORMAL_MEMORY) {
81819f0f
CL
2373 struct kmem_cache_node *n = get_node(s, node);
2374
2086d26a 2375 n->nr_partial -= free_list(s, n, &n->partial);
81819f0f
CL
2376 if (atomic_long_read(&n->nr_slabs))
2377 return 1;
2378 }
2379 free_kmem_cache_nodes(s);
2380 return 0;
2381}
2382
2383/*
2384 * Close a cache and release the kmem_cache structure
2385 * (must be used for caches created using kmem_cache_create)
2386 */
2387void kmem_cache_destroy(struct kmem_cache *s)
2388{
2389 down_write(&slub_lock);
2390 s->refcount--;
2391 if (!s->refcount) {
2392 list_del(&s->list);
a0e1d1be 2393 up_write(&slub_lock);
81819f0f
CL
2394 if (kmem_cache_close(s))
2395 WARN_ON(1);
2396 sysfs_slab_remove(s);
a0e1d1be
CL
2397 } else
2398 up_write(&slub_lock);
81819f0f
CL
2399}
2400EXPORT_SYMBOL(kmem_cache_destroy);
2401
2402/********************************************************************
2403 * Kmalloc subsystem
2404 *******************************************************************/
2405
331dc558 2406struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned;
81819f0f
CL
2407EXPORT_SYMBOL(kmalloc_caches);
2408
2409#ifdef CONFIG_ZONE_DMA
331dc558 2410static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
81819f0f
CL
2411#endif
2412
2413static int __init setup_slub_min_order(char *str)
2414{
06428780 2415 get_option(&str, &slub_min_order);
81819f0f
CL
2416
2417 return 1;
2418}
2419
2420__setup("slub_min_order=", setup_slub_min_order);
2421
2422static int __init setup_slub_max_order(char *str)
2423{
06428780 2424 get_option(&str, &slub_max_order);
81819f0f
CL
2425
2426 return 1;
2427}
2428
2429__setup("slub_max_order=", setup_slub_max_order);
2430
2431static int __init setup_slub_min_objects(char *str)
2432{
06428780 2433 get_option(&str, &slub_min_objects);
81819f0f
CL
2434
2435 return 1;
2436}
2437
2438__setup("slub_min_objects=", setup_slub_min_objects);
2439
2440static int __init setup_slub_nomerge(char *str)
2441{
2442 slub_nomerge = 1;
2443 return 1;
2444}
2445
2446__setup("slub_nomerge", setup_slub_nomerge);
2447
81819f0f
CL
2448static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
2449 const char *name, int size, gfp_t gfp_flags)
2450{
2451 unsigned int flags = 0;
2452
2453 if (gfp_flags & SLUB_DMA)
2454 flags = SLAB_CACHE_DMA;
2455
2456 down_write(&slub_lock);
2457 if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
71c7a06f 2458 flags | __KMALLOC_CACHE, NULL))
81819f0f
CL
2459 goto panic;
2460
2461 list_add(&s->list, &slab_caches);
2462 up_write(&slub_lock);
2463 if (sysfs_slab_add(s))
2464 goto panic;
2465 return s;
2466
2467panic:
2468 panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
2469}
2470
2e443fd0 2471#ifdef CONFIG_ZONE_DMA
1ceef402
CL
2472
2473static void sysfs_add_func(struct work_struct *w)
2474{
2475 struct kmem_cache *s;
2476
2477 down_write(&slub_lock);
2478 list_for_each_entry(s, &slab_caches, list) {
2479 if (s->flags & __SYSFS_ADD_DEFERRED) {
2480 s->flags &= ~__SYSFS_ADD_DEFERRED;
2481 sysfs_slab_add(s);
2482 }
2483 }
2484 up_write(&slub_lock);
2485}
2486
2487static DECLARE_WORK(sysfs_add_work, sysfs_add_func);
2488
2e443fd0
CL
2489static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
2490{
2491 struct kmem_cache *s;
2e443fd0
CL
2492 char *text;
2493 size_t realsize;
2494
2495 s = kmalloc_caches_dma[index];
2496 if (s)
2497 return s;
2498
2499 /* Dynamically create dma cache */
1ceef402
CL
2500 if (flags & __GFP_WAIT)
2501 down_write(&slub_lock);
2502 else {
2503 if (!down_write_trylock(&slub_lock))
2504 goto out;
2505 }
2506
2507 if (kmalloc_caches_dma[index])
2508 goto unlock_out;
2e443fd0 2509
7b55f620 2510 realsize = kmalloc_caches[index].objsize;
3adbefee
IM
2511 text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
2512 (unsigned int)realsize);
1ceef402
CL
2513 s = kmalloc(kmem_size, flags & ~SLUB_DMA);
2514
2515 if (!s || !text || !kmem_cache_open(s, flags, text,
2516 realsize, ARCH_KMALLOC_MINALIGN,
2517 SLAB_CACHE_DMA|__SYSFS_ADD_DEFERRED, NULL)) {
2518 kfree(s);
2519 kfree(text);
2520 goto unlock_out;
dfce8648 2521 }
1ceef402
CL
2522
2523 list_add(&s->list, &slab_caches);
2524 kmalloc_caches_dma[index] = s;
2525
2526 schedule_work(&sysfs_add_work);
2527
2528unlock_out:
dfce8648 2529 up_write(&slub_lock);
1ceef402 2530out:
dfce8648 2531 return kmalloc_caches_dma[index];
2e443fd0
CL
2532}
2533#endif
2534
f1b26339
CL
2535/*
2536 * Conversion table for small slabs sizes / 8 to the index in the
2537 * kmalloc array. This is necessary for slabs < 192 since we have non power
2538 * of two cache sizes there. The size of larger slabs can be determined using
2539 * fls.
2540 */
2541static s8 size_index[24] = {
2542 3, /* 8 */
2543 4, /* 16 */
2544 5, /* 24 */
2545 5, /* 32 */
2546 6, /* 40 */
2547 6, /* 48 */
2548 6, /* 56 */
2549 6, /* 64 */
2550 1, /* 72 */
2551 1, /* 80 */
2552 1, /* 88 */
2553 1, /* 96 */
2554 7, /* 104 */
2555 7, /* 112 */
2556 7, /* 120 */
2557 7, /* 128 */
2558 2, /* 136 */
2559 2, /* 144 */
2560 2, /* 152 */
2561 2, /* 160 */
2562 2, /* 168 */
2563 2, /* 176 */
2564 2, /* 184 */
2565 2 /* 192 */
2566};
2567
81819f0f
CL
2568static struct kmem_cache *get_slab(size_t size, gfp_t flags)
2569{
f1b26339 2570 int index;
81819f0f 2571
f1b26339
CL
2572 if (size <= 192) {
2573 if (!size)
2574 return ZERO_SIZE_PTR;
81819f0f 2575
f1b26339 2576 index = size_index[(size - 1) / 8];
aadb4bc4 2577 } else
f1b26339 2578 index = fls(size - 1);
81819f0f
CL
2579
2580#ifdef CONFIG_ZONE_DMA
f1b26339 2581 if (unlikely((flags & SLUB_DMA)))
2e443fd0 2582 return dma_kmalloc_cache(index, flags);
f1b26339 2583
81819f0f
CL
2584#endif
2585 return &kmalloc_caches[index];
2586}
2587
2588void *__kmalloc(size_t size, gfp_t flags)
2589{
aadb4bc4 2590 struct kmem_cache *s;
81819f0f 2591
331dc558 2592 if (unlikely(size > PAGE_SIZE))
eada35ef 2593 return kmalloc_large(size, flags);
aadb4bc4
CL
2594
2595 s = get_slab(size, flags);
2596
2597 if (unlikely(ZERO_OR_NULL_PTR(s)))
6cb8f913
CL
2598 return s;
2599
ce15fea8 2600 return slab_alloc(s, flags, -1, __builtin_return_address(0));
81819f0f
CL
2601}
2602EXPORT_SYMBOL(__kmalloc);
2603
f619cfe1
CL
2604static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
2605{
2606 struct page *page = alloc_pages_node(node, flags | __GFP_COMP,
2607 get_order(size));
2608
2609 if (page)
2610 return page_address(page);
2611 else
2612 return NULL;
2613}
2614
81819f0f
CL
2615#ifdef CONFIG_NUMA
2616void *__kmalloc_node(size_t size, gfp_t flags, int node)
2617{
aadb4bc4 2618 struct kmem_cache *s;
81819f0f 2619
331dc558 2620 if (unlikely(size > PAGE_SIZE))
f619cfe1 2621 return kmalloc_large_node(size, flags, node);
aadb4bc4
CL
2622
2623 s = get_slab(size, flags);
2624
2625 if (unlikely(ZERO_OR_NULL_PTR(s)))
6cb8f913
CL
2626 return s;
2627
ce15fea8 2628 return slab_alloc(s, flags, node, __builtin_return_address(0));
81819f0f
CL
2629}
2630EXPORT_SYMBOL(__kmalloc_node);
2631#endif
2632
2633size_t ksize(const void *object)
2634{
272c1d21 2635 struct page *page;
81819f0f
CL
2636 struct kmem_cache *s;
2637
ef8b4520 2638 if (unlikely(object == ZERO_SIZE_PTR))
272c1d21
CL
2639 return 0;
2640
294a80a8 2641 page = virt_to_head_page(object);
294a80a8
VN
2642
2643 if (unlikely(!PageSlab(page)))
2644 return PAGE_SIZE << compound_order(page);
2645
81819f0f 2646 s = page->slab;
81819f0f 2647
ae20bfda 2648#ifdef CONFIG_SLUB_DEBUG
81819f0f
CL
2649 /*
2650 * Debugging requires use of the padding between object
2651 * and whatever may come after it.
2652 */
2653 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
2654 return s->objsize;
2655
ae20bfda 2656#endif
81819f0f
CL
2657 /*
2658 * If we have the need to store the freelist pointer
2659 * back there or track user information then we can
2660 * only use the space before that information.
2661 */
2662 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
2663 return s->inuse;
81819f0f
CL
2664 /*
2665 * Else we can use all the padding etc for the allocation
2666 */
2667 return s->size;
2668}
2669EXPORT_SYMBOL(ksize);
2670
2671void kfree(const void *x)
2672{
81819f0f 2673 struct page *page;
5bb983b0 2674 void *object = (void *)x;
81819f0f 2675
2408c550 2676 if (unlikely(ZERO_OR_NULL_PTR(x)))
81819f0f
CL
2677 return;
2678
b49af68f 2679 page = virt_to_head_page(x);
aadb4bc4
CL
2680 if (unlikely(!PageSlab(page))) {
2681 put_page(page);
2682 return;
2683 }
5bb983b0 2684 slab_free(page->slab, page, object, __builtin_return_address(0));
81819f0f
CL
2685}
2686EXPORT_SYMBOL(kfree);
2687
f61396ae
CL
2688static unsigned long count_partial(struct kmem_cache_node *n)
2689{
2690 unsigned long flags;
2691 unsigned long x = 0;
2692 struct page *page;
2693
2694 spin_lock_irqsave(&n->list_lock, flags);
2695 list_for_each_entry(page, &n->partial, lru)
2696 x += page->inuse;
2697 spin_unlock_irqrestore(&n->list_lock, flags);
2698 return x;
2699}
2700
2086d26a 2701/*
672bba3a
CL
2702 * kmem_cache_shrink removes empty slabs from the partial lists and sorts
2703 * the remaining slabs by the number of items in use. The slabs with the
2704 * most items in use come first. New allocations will then fill those up
2705 * and thus they can be removed from the partial lists.
2706 *
2707 * The slabs with the least items are placed last. This results in them
2708 * being allocated from last increasing the chance that the last objects
2709 * are freed in them.
2086d26a
CL
2710 */
2711int kmem_cache_shrink(struct kmem_cache *s)
2712{
2713 int node;
2714 int i;
2715 struct kmem_cache_node *n;
2716 struct page *page;
2717 struct page *t;
2718 struct list_head *slabs_by_inuse =
2719 kmalloc(sizeof(struct list_head) * s->objects, GFP_KERNEL);
2720 unsigned long flags;
2721
2722 if (!slabs_by_inuse)
2723 return -ENOMEM;
2724
2725 flush_all(s);
f64dc58c 2726 for_each_node_state(node, N_NORMAL_MEMORY) {
2086d26a
CL
2727 n = get_node(s, node);
2728
2729 if (!n->nr_partial)
2730 continue;
2731
2732 for (i = 0; i < s->objects; i++)
2733 INIT_LIST_HEAD(slabs_by_inuse + i);
2734
2735 spin_lock_irqsave(&n->list_lock, flags);
2736
2737 /*
672bba3a 2738 * Build lists indexed by the items in use in each slab.
2086d26a 2739 *
672bba3a
CL
2740 * Note that concurrent frees may occur while we hold the
2741 * list_lock. page->inuse here is the upper limit.
2086d26a
CL
2742 */
2743 list_for_each_entry_safe(page, t, &n->partial, lru) {
2744 if (!page->inuse && slab_trylock(page)) {
2745 /*
2746 * Must hold slab lock here because slab_free
2747 * may have freed the last object and be
2748 * waiting to release the slab.
2749 */
2750 list_del(&page->lru);
2751 n->nr_partial--;
2752 slab_unlock(page);
2753 discard_slab(s, page);
2754 } else {
fcda3d89
CL
2755 list_move(&page->lru,
2756 slabs_by_inuse + page->inuse);
2086d26a
CL
2757 }
2758 }
2759
2086d26a 2760 /*
672bba3a
CL
2761 * Rebuild the partial list with the slabs filled up most
2762 * first and the least used slabs at the end.
2086d26a
CL
2763 */
2764 for (i = s->objects - 1; i >= 0; i--)
2765 list_splice(slabs_by_inuse + i, n->partial.prev);
2766
2086d26a
CL
2767 spin_unlock_irqrestore(&n->list_lock, flags);
2768 }
2769
2770 kfree(slabs_by_inuse);
2771 return 0;
2772}
2773EXPORT_SYMBOL(kmem_cache_shrink);
2774
b9049e23
YG
2775#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
2776static int slab_mem_going_offline_callback(void *arg)
2777{
2778 struct kmem_cache *s;
2779
2780 down_read(&slub_lock);
2781 list_for_each_entry(s, &slab_caches, list)
2782 kmem_cache_shrink(s);
2783 up_read(&slub_lock);
2784
2785 return 0;
2786}
2787
2788static void slab_mem_offline_callback(void *arg)
2789{
2790 struct kmem_cache_node *n;
2791 struct kmem_cache *s;
2792 struct memory_notify *marg = arg;
2793 int offline_node;
2794
2795 offline_node = marg->status_change_nid;
2796
2797 /*
2798 * If the node still has available memory. we need kmem_cache_node
2799 * for it yet.
2800 */
2801 if (offline_node < 0)
2802 return;
2803
2804 down_read(&slub_lock);
2805 list_for_each_entry(s, &slab_caches, list) {
2806 n = get_node(s, offline_node);
2807 if (n) {
2808 /*
2809 * if n->nr_slabs > 0, slabs still exist on the node
2810 * that is going down. We were unable to free them,
2811 * and offline_pages() function shoudn't call this
2812 * callback. So, we must fail.
2813 */
27bb628a 2814 BUG_ON(atomic_long_read(&n->nr_slabs));
b9049e23
YG
2815
2816 s->node[offline_node] = NULL;
2817 kmem_cache_free(kmalloc_caches, n);
2818 }
2819 }
2820 up_read(&slub_lock);
2821}
2822
2823static int slab_mem_going_online_callback(void *arg)
2824{
2825 struct kmem_cache_node *n;
2826 struct kmem_cache *s;
2827 struct memory_notify *marg = arg;
2828 int nid = marg->status_change_nid;
2829 int ret = 0;
2830
2831 /*
2832 * If the node's memory is already available, then kmem_cache_node is
2833 * already created. Nothing to do.
2834 */
2835 if (nid < 0)
2836 return 0;
2837
2838 /*
2839 * We are bringing a node online. No memory is availabe yet. We must
2840 * allocate a kmem_cache_node structure in order to bring the node
2841 * online.
2842 */
2843 down_read(&slub_lock);
2844 list_for_each_entry(s, &slab_caches, list) {
2845 /*
2846 * XXX: kmem_cache_alloc_node will fallback to other nodes
2847 * since memory is not yet available from the node that
2848 * is brought up.
2849 */
2850 n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL);
2851 if (!n) {
2852 ret = -ENOMEM;
2853 goto out;
2854 }
2855 init_kmem_cache_node(n);
2856 s->node[nid] = n;
2857 }
2858out:
2859 up_read(&slub_lock);
2860 return ret;
2861}
2862
2863static int slab_memory_callback(struct notifier_block *self,
2864 unsigned long action, void *arg)
2865{
2866 int ret = 0;
2867
2868 switch (action) {
2869 case MEM_GOING_ONLINE:
2870 ret = slab_mem_going_online_callback(arg);
2871 break;
2872 case MEM_GOING_OFFLINE:
2873 ret = slab_mem_going_offline_callback(arg);
2874 break;
2875 case MEM_OFFLINE:
2876 case MEM_CANCEL_ONLINE:
2877 slab_mem_offline_callback(arg);
2878 break;
2879 case MEM_ONLINE:
2880 case MEM_CANCEL_OFFLINE:
2881 break;
2882 }
2883
2884 ret = notifier_from_errno(ret);
2885 return ret;
2886}
2887
2888#endif /* CONFIG_MEMORY_HOTPLUG */
2889
81819f0f
CL
2890/********************************************************************
2891 * Basic setup of slabs
2892 *******************************************************************/
2893
2894void __init kmem_cache_init(void)
2895{
2896 int i;
4b356be0 2897 int caches = 0;
81819f0f 2898
4c93c355
CL
2899 init_alloc_cpu();
2900
81819f0f
CL
2901#ifdef CONFIG_NUMA
2902 /*
2903 * Must first have the slab cache available for the allocations of the
672bba3a 2904 * struct kmem_cache_node's. There is special bootstrap code in
81819f0f
CL
2905 * kmem_cache_open for slab_state == DOWN.
2906 */
2907 create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
2908 sizeof(struct kmem_cache_node), GFP_KERNEL);
8ffa6875 2909 kmalloc_caches[0].refcount = -1;
4b356be0 2910 caches++;
b9049e23
YG
2911
2912 hotplug_memory_notifier(slab_memory_callback, 1);
81819f0f
CL
2913#endif
2914
2915 /* Able to allocate the per node structures */
2916 slab_state = PARTIAL;
2917
2918 /* Caches that are not of the two-to-the-power-of size */
4b356be0
CL
2919 if (KMALLOC_MIN_SIZE <= 64) {
2920 create_kmalloc_cache(&kmalloc_caches[1],
81819f0f 2921 "kmalloc-96", 96, GFP_KERNEL);
4b356be0
CL
2922 caches++;
2923 }
2924 if (KMALLOC_MIN_SIZE <= 128) {
2925 create_kmalloc_cache(&kmalloc_caches[2],
81819f0f 2926 "kmalloc-192", 192, GFP_KERNEL);
4b356be0
CL
2927 caches++;
2928 }
81819f0f 2929
331dc558 2930 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) {
81819f0f
CL
2931 create_kmalloc_cache(&kmalloc_caches[i],
2932 "kmalloc", 1 << i, GFP_KERNEL);
4b356be0
CL
2933 caches++;
2934 }
81819f0f 2935
f1b26339
CL
2936
2937 /*
2938 * Patch up the size_index table if we have strange large alignment
2939 * requirements for the kmalloc array. This is only the case for
6446faa2 2940 * MIPS it seems. The standard arches will not generate any code here.
f1b26339
CL
2941 *
2942 * Largest permitted alignment is 256 bytes due to the way we
2943 * handle the index determination for the smaller caches.
2944 *
2945 * Make sure that nothing crazy happens if someone starts tinkering
2946 * around with ARCH_KMALLOC_MINALIGN
2947 */
2948 BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
2949 (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
2950
12ad6843 2951 for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
f1b26339
CL
2952 size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;
2953
81819f0f
CL
2954 slab_state = UP;
2955
2956 /* Provide the correct kmalloc names now that the caches are up */
331dc558 2957 for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++)
81819f0f
CL
2958 kmalloc_caches[i]. name =
2959 kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
2960
2961#ifdef CONFIG_SMP
2962 register_cpu_notifier(&slab_notifier);
4c93c355
CL
2963 kmem_size = offsetof(struct kmem_cache, cpu_slab) +
2964 nr_cpu_ids * sizeof(struct kmem_cache_cpu *);
2965#else
2966 kmem_size = sizeof(struct kmem_cache);
81819f0f
CL
2967#endif
2968
3adbefee
IM
2969 printk(KERN_INFO
2970 "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
4b356be0
CL
2971 " CPUs=%d, Nodes=%d\n",
2972 caches, cache_line_size(),
81819f0f
CL
2973 slub_min_order, slub_max_order, slub_min_objects,
2974 nr_cpu_ids, nr_node_ids);
2975}
2976
2977/*
2978 * Find a mergeable slab cache
2979 */
2980static int slab_unmergeable(struct kmem_cache *s)
2981{
2982 if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
2983 return 1;
2984
331dc558 2985 if ((s->flags & __PAGE_ALLOC_FALLBACK))
71c7a06f
CL
2986 return 1;
2987
c59def9f 2988 if (s->ctor)
81819f0f
CL
2989 return 1;
2990
8ffa6875
CL
2991 /*
2992 * We may have set a slab to be unmergeable during bootstrap.
2993 */
2994 if (s->refcount < 0)
2995 return 1;
2996
81819f0f
CL
2997 return 0;
2998}
2999
3000static struct kmem_cache *find_mergeable(size_t size,
ba0268a8 3001 size_t align, unsigned long flags, const char *name,
4ba9b9d0 3002 void (*ctor)(struct kmem_cache *, void *))
81819f0f 3003{
5b95a4ac 3004 struct kmem_cache *s;
81819f0f
CL
3005
3006 if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
3007 return NULL;
3008
c59def9f 3009 if (ctor)
81819f0f
CL
3010 return NULL;
3011
3012 size = ALIGN(size, sizeof(void *));
3013 align = calculate_alignment(flags, align, size);
3014 size = ALIGN(size, align);
ba0268a8 3015 flags = kmem_cache_flags(size, flags, name, NULL);
81819f0f 3016
5b95a4ac 3017 list_for_each_entry(s, &slab_caches, list) {
81819f0f
CL
3018 if (slab_unmergeable(s))
3019 continue;
3020
3021 if (size > s->size)
3022 continue;
3023
ba0268a8 3024 if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
81819f0f
CL
3025 continue;
3026 /*
3027 * Check if alignment is compatible.
3028 * Courtesy of Adrian Drzewiecki
3029 */
06428780 3030 if ((s->size & ~(align - 1)) != s->size)
81819f0f
CL
3031 continue;
3032
3033 if (s->size - size >= sizeof(void *))
3034 continue;
3035
3036 return s;
3037 }
3038 return NULL;
3039}
3040
3041struct kmem_cache *kmem_cache_create(const char *name, size_t size,
3042 size_t align, unsigned long flags,
4ba9b9d0 3043 void (*ctor)(struct kmem_cache *, void *))
81819f0f
CL
3044{
3045 struct kmem_cache *s;
3046
3047 down_write(&slub_lock);
ba0268a8 3048 s = find_mergeable(size, align, flags, name, ctor);
81819f0f 3049 if (s) {
42a9fdbb
CL
3050 int cpu;
3051
81819f0f
CL
3052 s->refcount++;
3053 /*
3054 * Adjust the object sizes so that we clear
3055 * the complete object on kzalloc.
3056 */
3057 s->objsize = max(s->objsize, (int)size);
42a9fdbb
CL
3058
3059 /*
3060 * And then we need to update the object size in the
3061 * per cpu structures
3062 */
3063 for_each_online_cpu(cpu)
3064 get_cpu_slab(s, cpu)->objsize = s->objsize;
6446faa2 3065
81819f0f 3066 s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
a0e1d1be 3067 up_write(&slub_lock);
6446faa2 3068
81819f0f
CL
3069 if (sysfs_slab_alias(s, name))
3070 goto err;
a0e1d1be
CL
3071 return s;
3072 }
6446faa2 3073
a0e1d1be
CL
3074 s = kmalloc(kmem_size, GFP_KERNEL);
3075 if (s) {
3076 if (kmem_cache_open(s, GFP_KERNEL, name,
c59def9f 3077 size, align, flags, ctor)) {
81819f0f 3078 list_add(&s->list, &slab_caches);
a0e1d1be
CL
3079 up_write(&slub_lock);
3080 if (sysfs_slab_add(s))
3081 goto err;
3082 return s;
3083 }
3084 kfree(s);
81819f0f
CL
3085 }
3086 up_write(&slub_lock);
81819f0f
CL
3087
3088err:
81819f0f
CL
3089 if (flags & SLAB_PANIC)
3090 panic("Cannot create slabcache %s\n", name);
3091 else
3092 s = NULL;
3093 return s;
3094}
3095EXPORT_SYMBOL(kmem_cache_create);
3096
81819f0f 3097#ifdef CONFIG_SMP
81819f0f 3098/*
672bba3a
CL
3099 * Use the cpu notifier to insure that the cpu slabs are flushed when
3100 * necessary.
81819f0f
CL
3101 */
3102static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
3103 unsigned long action, void *hcpu)
3104{
3105 long cpu = (long)hcpu;
5b95a4ac
CL
3106 struct kmem_cache *s;
3107 unsigned long flags;
81819f0f
CL
3108
3109 switch (action) {
4c93c355
CL
3110 case CPU_UP_PREPARE:
3111 case CPU_UP_PREPARE_FROZEN:
3112 init_alloc_cpu_cpu(cpu);
3113 down_read(&slub_lock);
3114 list_for_each_entry(s, &slab_caches, list)
3115 s->cpu_slab[cpu] = alloc_kmem_cache_cpu(s, cpu,
3116 GFP_KERNEL);
3117 up_read(&slub_lock);
3118 break;
3119
81819f0f 3120 case CPU_UP_CANCELED:
8bb78442 3121 case CPU_UP_CANCELED_FROZEN:
81819f0f 3122 case CPU_DEAD:
8bb78442 3123 case CPU_DEAD_FROZEN:
5b95a4ac
CL
3124 down_read(&slub_lock);
3125 list_for_each_entry(s, &slab_caches, list) {
4c93c355
CL
3126 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
3127
5b95a4ac
CL
3128 local_irq_save(flags);
3129 __flush_cpu_slab(s, cpu);
3130 local_irq_restore(flags);
4c93c355
CL
3131 free_kmem_cache_cpu(c, cpu);
3132 s->cpu_slab[cpu] = NULL;
5b95a4ac
CL
3133 }
3134 up_read(&slub_lock);
81819f0f
CL
3135 break;
3136 default:
3137 break;
3138 }
3139 return NOTIFY_OK;
3140}
3141
06428780 3142static struct notifier_block __cpuinitdata slab_notifier = {
3adbefee 3143 .notifier_call = slab_cpuup_callback
06428780 3144};
81819f0f
CL
3145
3146#endif
3147
81819f0f
CL
3148void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
3149{
aadb4bc4
CL
3150 struct kmem_cache *s;
3151
331dc558 3152 if (unlikely(size > PAGE_SIZE))
eada35ef
PE
3153 return kmalloc_large(size, gfpflags);
3154
aadb4bc4 3155 s = get_slab(size, gfpflags);
81819f0f 3156
2408c550 3157 if (unlikely(ZERO_OR_NULL_PTR(s)))
6cb8f913 3158 return s;
81819f0f 3159
ce15fea8 3160 return slab_alloc(s, gfpflags, -1, caller);
81819f0f
CL
3161}
3162
3163void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
3164 int node, void *caller)
3165{
aadb4bc4
CL
3166 struct kmem_cache *s;
3167
331dc558 3168 if (unlikely(size > PAGE_SIZE))
f619cfe1 3169 return kmalloc_large_node(size, gfpflags, node);
eada35ef 3170
aadb4bc4 3171 s = get_slab(size, gfpflags);
81819f0f 3172
2408c550 3173 if (unlikely(ZERO_OR_NULL_PTR(s)))
6cb8f913 3174 return s;
81819f0f 3175
ce15fea8 3176 return slab_alloc(s, gfpflags, node, caller);
81819f0f
CL
3177}
3178
41ecc55b 3179#if defined(CONFIG_SYSFS) && defined(CONFIG_SLUB_DEBUG)
434e245d
CL
3180static int validate_slab(struct kmem_cache *s, struct page *page,
3181 unsigned long *map)
53e15af0
CL
3182{
3183 void *p;
a973e9dd 3184 void *addr = page_address(page);
53e15af0
CL
3185
3186 if (!check_slab(s, page) ||
3187 !on_freelist(s, page, NULL))
3188 return 0;
3189
3190 /* Now we know that a valid freelist exists */
3191 bitmap_zero(map, s->objects);
3192
7656c72b
CL
3193 for_each_free_object(p, s, page->freelist) {
3194 set_bit(slab_index(p, s, addr), map);
53e15af0
CL
3195 if (!check_object(s, page, p, 0))
3196 return 0;
3197 }
3198
7656c72b
CL
3199 for_each_object(p, s, addr)
3200 if (!test_bit(slab_index(p, s, addr), map))
53e15af0
CL
3201 if (!check_object(s, page, p, 1))
3202 return 0;
3203 return 1;
3204}
3205
434e245d
CL
3206static void validate_slab_slab(struct kmem_cache *s, struct page *page,
3207 unsigned long *map)
53e15af0
CL
3208{
3209 if (slab_trylock(page)) {
434e245d 3210 validate_slab(s, page, map);
53e15af0
CL
3211 slab_unlock(page);
3212 } else
3213 printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n",
3214 s->name, page);
3215
3216 if (s->flags & DEBUG_DEFAULT_FLAGS) {
35e5d7ee
CL
3217 if (!SlabDebug(page))
3218 printk(KERN_ERR "SLUB %s: SlabDebug not set "
53e15af0
CL
3219 "on slab 0x%p\n", s->name, page);
3220 } else {
35e5d7ee
CL
3221 if (SlabDebug(page))
3222 printk(KERN_ERR "SLUB %s: SlabDebug set on "
53e15af0
CL
3223 "slab 0x%p\n", s->name, page);
3224 }
3225}
3226
434e245d
CL
3227static int validate_slab_node(struct kmem_cache *s,
3228 struct kmem_cache_node *n, unsigned long *map)
53e15af0
CL
3229{
3230 unsigned long count = 0;
3231 struct page *page;
3232 unsigned long flags;
3233
3234 spin_lock_irqsave(&n->list_lock, flags);
3235
3236 list_for_each_entry(page, &n->partial, lru) {
434e245d 3237 validate_slab_slab(s, page, map);
53e15af0
CL
3238 count++;
3239 }
3240 if (count != n->nr_partial)
3241 printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
3242 "counter=%ld\n", s->name, count, n->nr_partial);
3243
3244 if (!(s->flags & SLAB_STORE_USER))
3245 goto out;
3246
3247 list_for_each_entry(page, &n->full, lru) {
434e245d 3248 validate_slab_slab(s, page, map);
53e15af0
CL
3249 count++;
3250 }
3251 if (count != atomic_long_read(&n->nr_slabs))
3252 printk(KERN_ERR "SLUB: %s %ld slabs counted but "
3253 "counter=%ld\n", s->name, count,
3254 atomic_long_read(&n->nr_slabs));
3255
3256out:
3257 spin_unlock_irqrestore(&n->list_lock, flags);
3258 return count;
3259}
3260
434e245d 3261static long validate_slab_cache(struct kmem_cache *s)
53e15af0
CL
3262{
3263 int node;
3264 unsigned long count = 0;
434e245d
CL
3265 unsigned long *map = kmalloc(BITS_TO_LONGS(s->objects) *
3266 sizeof(unsigned long), GFP_KERNEL);
3267
3268 if (!map)
3269 return -ENOMEM;
53e15af0
CL
3270
3271 flush_all(s);
f64dc58c 3272 for_each_node_state(node, N_NORMAL_MEMORY) {
53e15af0
CL
3273 struct kmem_cache_node *n = get_node(s, node);
3274
434e245d 3275 count += validate_slab_node(s, n, map);
53e15af0 3276 }
434e245d 3277 kfree(map);
53e15af0
CL
3278 return count;
3279}
3280
b3459709
CL
3281#ifdef SLUB_RESILIENCY_TEST
3282static void resiliency_test(void)
3283{
3284 u8 *p;
3285
3286 printk(KERN_ERR "SLUB resiliency testing\n");
3287 printk(KERN_ERR "-----------------------\n");
3288 printk(KERN_ERR "A. Corruption after allocation\n");
3289
3290 p = kzalloc(16, GFP_KERNEL);
3291 p[16] = 0x12;
3292 printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
3293 " 0x12->0x%p\n\n", p + 16);
3294
3295 validate_slab_cache(kmalloc_caches + 4);
3296
3297 /* Hmmm... The next two are dangerous */
3298 p = kzalloc(32, GFP_KERNEL);
3299 p[32 + sizeof(void *)] = 0x34;
3300 printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
3adbefee
IM
3301 " 0x34 -> -0x%p\n", p);
3302 printk(KERN_ERR
3303 "If allocated object is overwritten then not detectable\n\n");
b3459709
CL
3304
3305 validate_slab_cache(kmalloc_caches + 5);
3306 p = kzalloc(64, GFP_KERNEL);
3307 p += 64 + (get_cycles() & 0xff) * sizeof(void *);
3308 *p = 0x56;
3309 printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
3310 p);
3adbefee
IM
3311 printk(KERN_ERR
3312 "If allocated object is overwritten then not detectable\n\n");
b3459709
CL
3313 validate_slab_cache(kmalloc_caches + 6);
3314
3315 printk(KERN_ERR "\nB. Corruption after free\n");
3316 p = kzalloc(128, GFP_KERNEL);
3317 kfree(p);
3318 *p = 0x78;
3319 printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
3320 validate_slab_cache(kmalloc_caches + 7);
3321
3322 p = kzalloc(256, GFP_KERNEL);
3323 kfree(p);
3324 p[50] = 0x9a;
3adbefee
IM
3325 printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
3326 p);
b3459709
CL
3327 validate_slab_cache(kmalloc_caches + 8);
3328
3329 p = kzalloc(512, GFP_KERNEL);
3330 kfree(p);
3331 p[512] = 0xab;
3332 printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
3333 validate_slab_cache(kmalloc_caches + 9);
3334}
3335#else
3336static void resiliency_test(void) {};
3337#endif
3338
88a420e4 3339/*
672bba3a 3340 * Generate lists of code addresses where slabcache objects are allocated
88a420e4
CL
3341 * and freed.
3342 */
3343
3344struct location {
3345 unsigned long count;
3346 void *addr;
45edfa58
CL
3347 long long sum_time;
3348 long min_time;
3349 long max_time;
3350 long min_pid;
3351 long max_pid;
3352 cpumask_t cpus;
3353 nodemask_t nodes;
88a420e4
CL
3354};
3355
3356struct loc_track {
3357 unsigned long max;
3358 unsigned long count;
3359 struct location *loc;
3360};
3361
3362static void free_loc_track(struct loc_track *t)
3363{
3364 if (t->max)
3365 free_pages((unsigned long)t->loc,
3366 get_order(sizeof(struct location) * t->max));
3367}
3368
68dff6a9 3369static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
88a420e4
CL
3370{
3371 struct location *l;
3372 int order;
3373
88a420e4
CL
3374 order = get_order(sizeof(struct location) * max);
3375
68dff6a9 3376 l = (void *)__get_free_pages(flags, order);
88a420e4
CL
3377 if (!l)
3378 return 0;
3379
3380 if (t->count) {
3381 memcpy(l, t->loc, sizeof(struct location) * t->count);
3382 free_loc_track(t);
3383 }
3384 t->max = max;
3385 t->loc = l;
3386 return 1;
3387}
3388
3389static int add_location(struct loc_track *t, struct kmem_cache *s,
45edfa58 3390 const struct track *track)
88a420e4
CL
3391{
3392 long start, end, pos;
3393 struct location *l;
3394 void *caddr;
45edfa58 3395 unsigned long age = jiffies - track->when;
88a420e4
CL
3396
3397 start = -1;
3398 end = t->count;
3399
3400 for ( ; ; ) {
3401 pos = start + (end - start + 1) / 2;
3402
3403 /*
3404 * There is nothing at "end". If we end up there
3405 * we need to add something to before end.
3406 */
3407 if (pos == end)
3408 break;
3409
3410 caddr = t->loc[pos].addr;
45edfa58
CL
3411 if (track->addr == caddr) {
3412
3413 l = &t->loc[pos];
3414 l->count++;
3415 if (track->when) {
3416 l->sum_time += age;
3417 if (age < l->min_time)
3418 l->min_time = age;
3419 if (age > l->max_time)
3420 l->max_time = age;
3421
3422 if (track->pid < l->min_pid)
3423 l->min_pid = track->pid;
3424 if (track->pid > l->max_pid)
3425 l->max_pid = track->pid;
3426
3427 cpu_set(track->cpu, l->cpus);
3428 }
3429 node_set(page_to_nid(virt_to_page(track)), l->nodes);
88a420e4
CL
3430 return 1;
3431 }
3432
45edfa58 3433 if (track->addr < caddr)
88a420e4
CL
3434 end = pos;
3435 else
3436 start = pos;
3437 }
3438
3439 /*
672bba3a 3440 * Not found. Insert new tracking element.
88a420e4 3441 */
68dff6a9 3442 if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
88a420e4
CL
3443 return 0;
3444
3445 l = t->loc + pos;
3446 if (pos < t->count)
3447 memmove(l + 1, l,
3448 (t->count - pos) * sizeof(struct location));
3449 t->count++;
3450 l->count = 1;
45edfa58
CL
3451 l->addr = track->addr;
3452 l->sum_time = age;
3453 l->min_time = age;
3454 l->max_time = age;
3455 l->min_pid = track->pid;
3456 l->max_pid = track->pid;
3457 cpus_clear(l->cpus);
3458 cpu_set(track->cpu, l->cpus);
3459 nodes_clear(l->nodes);
3460 node_set(page_to_nid(virt_to_page(track)), l->nodes);
88a420e4
CL
3461 return 1;
3462}
3463
3464static void process_slab(struct loc_track *t, struct kmem_cache *s,
3465 struct page *page, enum track_item alloc)
3466{
a973e9dd 3467 void *addr = page_address(page);
7656c72b 3468 DECLARE_BITMAP(map, s->objects);
88a420e4
CL
3469 void *p;
3470
3471 bitmap_zero(map, s->objects);
7656c72b
CL
3472 for_each_free_object(p, s, page->freelist)
3473 set_bit(slab_index(p, s, addr), map);
88a420e4 3474
7656c72b 3475 for_each_object(p, s, addr)
45edfa58
CL
3476 if (!test_bit(slab_index(p, s, addr), map))
3477 add_location(t, s, get_track(s, p, alloc));
88a420e4
CL
3478}
3479
3480static int list_locations(struct kmem_cache *s, char *buf,
3481 enum track_item alloc)
3482{
e374d483 3483 int len = 0;
88a420e4 3484 unsigned long i;
68dff6a9 3485 struct loc_track t = { 0, 0, NULL };
88a420e4
CL
3486 int node;
3487
68dff6a9 3488 if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
ea3061d2 3489 GFP_TEMPORARY))
68dff6a9 3490 return sprintf(buf, "Out of memory\n");
88a420e4
CL
3491
3492 /* Push back cpu slabs */
3493 flush_all(s);
3494
f64dc58c 3495 for_each_node_state(node, N_NORMAL_MEMORY) {
88a420e4
CL
3496 struct kmem_cache_node *n = get_node(s, node);
3497 unsigned long flags;
3498 struct page *page;
3499
9e86943b 3500 if (!atomic_long_read(&n->nr_slabs))
88a420e4
CL
3501 continue;
3502
3503 spin_lock_irqsave(&n->list_lock, flags);
3504 list_for_each_entry(page, &n->partial, lru)
3505 process_slab(&t, s, page, alloc);
3506 list_for_each_entry(page, &n->full, lru)
3507 process_slab(&t, s, page, alloc);
3508 spin_unlock_irqrestore(&n->list_lock, flags);
3509 }
3510
3511 for (i = 0; i < t.count; i++) {
45edfa58 3512 struct location *l = &t.loc[i];
88a420e4 3513
e374d483 3514 if (len > PAGE_SIZE - 100)
88a420e4 3515 break;
e374d483 3516 len += sprintf(buf + len, "%7ld ", l->count);
45edfa58
CL
3517
3518 if (l->addr)
e374d483 3519 len += sprint_symbol(buf + len, (unsigned long)l->addr);
88a420e4 3520 else
e374d483 3521 len += sprintf(buf + len, "<not-available>");
45edfa58
CL
3522
3523 if (l->sum_time != l->min_time) {
3524 unsigned long remainder;
3525
e374d483 3526 len += sprintf(buf + len, " age=%ld/%ld/%ld",
45edfa58
CL
3527 l->min_time,
3528 div_long_long_rem(l->sum_time, l->count, &remainder),
3529 l->max_time);
3530 } else
e374d483 3531 len += sprintf(buf + len, " age=%ld",
45edfa58
CL
3532 l->min_time);
3533
3534 if (l->min_pid != l->max_pid)
e374d483 3535 len += sprintf(buf + len, " pid=%ld-%ld",
45edfa58
CL
3536 l->min_pid, l->max_pid);
3537 else
e374d483 3538 len += sprintf(buf + len, " pid=%ld",
45edfa58
CL
3539 l->min_pid);
3540
84966343 3541 if (num_online_cpus() > 1 && !cpus_empty(l->cpus) &&
e374d483
HH
3542 len < PAGE_SIZE - 60) {
3543 len += sprintf(buf + len, " cpus=");
3544 len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
45edfa58
CL
3545 l->cpus);
3546 }
3547
84966343 3548 if (num_online_nodes() > 1 && !nodes_empty(l->nodes) &&
e374d483
HH
3549 len < PAGE_SIZE - 60) {
3550 len += sprintf(buf + len, " nodes=");
3551 len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
45edfa58
CL
3552 l->nodes);
3553 }
3554
e374d483 3555 len += sprintf(buf + len, "\n");
88a420e4
CL
3556 }
3557
3558 free_loc_track(&t);
3559 if (!t.count)
e374d483
HH
3560 len += sprintf(buf, "No data\n");
3561 return len;
88a420e4
CL
3562}
3563
81819f0f
CL
3564enum slab_stat_type {
3565 SL_FULL,
3566 SL_PARTIAL,
3567 SL_CPU,
3568 SL_OBJECTS
3569};
3570
3571#define SO_FULL (1 << SL_FULL)
3572#define SO_PARTIAL (1 << SL_PARTIAL)
3573#define SO_CPU (1 << SL_CPU)
3574#define SO_OBJECTS (1 << SL_OBJECTS)
3575
62e5c4b4
CG
3576static ssize_t show_slab_objects(struct kmem_cache *s,
3577 char *buf, unsigned long flags)
81819f0f
CL
3578{
3579 unsigned long total = 0;
3580 int cpu;
3581 int node;
3582 int x;
3583 unsigned long *nodes;
3584 unsigned long *per_cpu;
3585
3586 nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
62e5c4b4
CG
3587 if (!nodes)
3588 return -ENOMEM;
81819f0f
CL
3589 per_cpu = nodes + nr_node_ids;
3590
3591 for_each_possible_cpu(cpu) {
dfb4f096
CL
3592 struct page *page;
3593 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
81819f0f 3594
dfb4f096
CL
3595 if (!c)
3596 continue;
3597
3598 page = c->page;
ee3c72a1
CL
3599 node = c->node;
3600 if (node < 0)
3601 continue;
81819f0f 3602 if (page) {
81819f0f 3603 if (flags & SO_CPU) {
81819f0f
CL
3604 if (flags & SO_OBJECTS)
3605 x = page->inuse;
3606 else
3607 x = 1;
3608 total += x;
ee3c72a1 3609 nodes[node] += x;
81819f0f 3610 }
ee3c72a1 3611 per_cpu[node]++;
81819f0f
CL
3612 }
3613 }
3614
f64dc58c 3615 for_each_node_state(node, N_NORMAL_MEMORY) {
81819f0f
CL
3616 struct kmem_cache_node *n = get_node(s, node);
3617
3618 if (flags & SO_PARTIAL) {
3619 if (flags & SO_OBJECTS)
3620 x = count_partial(n);
3621 else
3622 x = n->nr_partial;
3623 total += x;
3624 nodes[node] += x;
3625 }
3626
3627 if (flags & SO_FULL) {
9e86943b 3628 int full_slabs = atomic_long_read(&n->nr_slabs)
81819f0f
CL
3629 - per_cpu[node]
3630 - n->nr_partial;
3631
3632 if (flags & SO_OBJECTS)
3633 x = full_slabs * s->objects;
3634 else
3635 x = full_slabs;
3636 total += x;
3637 nodes[node] += x;
3638 }
3639 }
3640
3641 x = sprintf(buf, "%lu", total);
3642#ifdef CONFIG_NUMA
f64dc58c 3643 for_each_node_state(node, N_NORMAL_MEMORY)
81819f0f
CL
3644 if (nodes[node])
3645 x += sprintf(buf + x, " N%d=%lu",
3646 node, nodes[node]);
3647#endif
3648 kfree(nodes);
3649 return x + sprintf(buf + x, "\n");
3650}
3651
3652static int any_slab_objects(struct kmem_cache *s)
3653{
3654 int node;
3655 int cpu;
3656
dfb4f096
CL
3657 for_each_possible_cpu(cpu) {
3658 struct kmem_cache_cpu *c = get_cpu_slab(s, cpu);
3659
3660 if (c && c->page)
81819f0f 3661 return 1;
dfb4f096 3662 }
81819f0f 3663
dfb4f096 3664 for_each_online_node(node) {
81819f0f
CL
3665 struct kmem_cache_node *n = get_node(s, node);
3666
dfb4f096
CL
3667 if (!n)
3668 continue;
3669
9e86943b 3670 if (n->nr_partial || atomic_long_read(&n->nr_slabs))
81819f0f
CL
3671 return 1;
3672 }
3673 return 0;
3674}
3675
3676#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
3677#define to_slab(n) container_of(n, struct kmem_cache, kobj);
3678
3679struct slab_attribute {
3680 struct attribute attr;
3681 ssize_t (*show)(struct kmem_cache *s, char *buf);
3682 ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
3683};
3684
3685#define SLAB_ATTR_RO(_name) \
3686 static struct slab_attribute _name##_attr = __ATTR_RO(_name)
3687
3688#define SLAB_ATTR(_name) \
3689 static struct slab_attribute _name##_attr = \
3690 __ATTR(_name, 0644, _name##_show, _name##_store)
3691
81819f0f
CL
3692static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
3693{
3694 return sprintf(buf, "%d\n", s->size);
3695}
3696SLAB_ATTR_RO(slab_size);
3697
3698static ssize_t align_show(struct kmem_cache *s, char *buf)
3699{
3700 return sprintf(buf, "%d\n", s->align);
3701}
3702SLAB_ATTR_RO(align);
3703
3704static ssize_t object_size_show(struct kmem_cache *s, char *buf)
3705{
3706 return sprintf(buf, "%d\n", s->objsize);
3707}
3708SLAB_ATTR_RO(object_size);
3709
3710static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
3711{
3712 return sprintf(buf, "%d\n", s->objects);
3713}
3714SLAB_ATTR_RO(objs_per_slab);
3715
3716static ssize_t order_show(struct kmem_cache *s, char *buf)
3717{
3718 return sprintf(buf, "%d\n", s->order);
3719}
3720SLAB_ATTR_RO(order);
3721
3722static ssize_t ctor_show(struct kmem_cache *s, char *buf)
3723{
3724 if (s->ctor) {
3725 int n = sprint_symbol(buf, (unsigned long)s->ctor);
3726
3727 return n + sprintf(buf + n, "\n");
3728 }
3729 return 0;
3730}
3731SLAB_ATTR_RO(ctor);
3732
81819f0f
CL
3733static ssize_t aliases_show(struct kmem_cache *s, char *buf)
3734{
3735 return sprintf(buf, "%d\n", s->refcount - 1);
3736}
3737SLAB_ATTR_RO(aliases);
3738
3739static ssize_t slabs_show(struct kmem_cache *s, char *buf)
3740{
d9acf4b7 3741 return show_slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU);
81819f0f
CL
3742}
3743SLAB_ATTR_RO(slabs);
3744
3745static ssize_t partial_show(struct kmem_cache *s, char *buf)
3746{
d9acf4b7 3747 return show_slab_objects(s, buf, SO_PARTIAL);
81819f0f
CL
3748}
3749SLAB_ATTR_RO(partial);
3750
3751static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
3752{
d9acf4b7 3753 return show_slab_objects(s, buf, SO_CPU);
81819f0f
CL
3754}
3755SLAB_ATTR_RO(cpu_slabs);
3756
3757static ssize_t objects_show(struct kmem_cache *s, char *buf)
3758{
d9acf4b7 3759 return show_slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS);
81819f0f
CL
3760}
3761SLAB_ATTR_RO(objects);
3762
3763static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
3764{
3765 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
3766}
3767
3768static ssize_t sanity_checks_store(struct kmem_cache *s,
3769 const char *buf, size_t length)
3770{
3771 s->flags &= ~SLAB_DEBUG_FREE;
3772 if (buf[0] == '1')
3773 s->flags |= SLAB_DEBUG_FREE;
3774 return length;
3775}
3776SLAB_ATTR(sanity_checks);
3777
3778static ssize_t trace_show(struct kmem_cache *s, char *buf)
3779{
3780 return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
3781}
3782
3783static ssize_t trace_store(struct kmem_cache *s, const char *buf,
3784 size_t length)
3785{
3786 s->flags &= ~SLAB_TRACE;
3787 if (buf[0] == '1')
3788 s->flags |= SLAB_TRACE;
3789 return length;
3790}
3791SLAB_ATTR(trace);
3792
3793static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
3794{
3795 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
3796}
3797
3798static ssize_t reclaim_account_store(struct kmem_cache *s,
3799 const char *buf, size_t length)
3800{
3801 s->flags &= ~SLAB_RECLAIM_ACCOUNT;
3802 if (buf[0] == '1')
3803 s->flags |= SLAB_RECLAIM_ACCOUNT;
3804 return length;
3805}
3806SLAB_ATTR(reclaim_account);
3807
3808static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
3809{
5af60839 3810 return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
81819f0f
CL
3811}
3812SLAB_ATTR_RO(hwcache_align);
3813
3814#ifdef CONFIG_ZONE_DMA
3815static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
3816{
3817 return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
3818}
3819SLAB_ATTR_RO(cache_dma);
3820#endif
3821
3822static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
3823{
3824 return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
3825}
3826SLAB_ATTR_RO(destroy_by_rcu);
3827
3828static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
3829{
3830 return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
3831}
3832
3833static ssize_t red_zone_store(struct kmem_cache *s,
3834 const char *buf, size_t length)
3835{
3836 if (any_slab_objects(s))
3837 return -EBUSY;
3838
3839 s->flags &= ~SLAB_RED_ZONE;
3840 if (buf[0] == '1')
3841 s->flags |= SLAB_RED_ZONE;
3842 calculate_sizes(s);
3843 return length;
3844}
3845SLAB_ATTR(red_zone);
3846
3847static ssize_t poison_show(struct kmem_cache *s, char *buf)
3848{
3849 return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
3850}
3851
3852static ssize_t poison_store(struct kmem_cache *s,
3853 const char *buf, size_t length)
3854{
3855 if (any_slab_objects(s))
3856 return -EBUSY;
3857
3858 s->flags &= ~SLAB_POISON;
3859 if (buf[0] == '1')
3860 s->flags |= SLAB_POISON;
3861 calculate_sizes(s);
3862 return length;
3863}
3864SLAB_ATTR(poison);
3865
3866static ssize_t store_user_show(struct kmem_cache *s, char *buf)
3867{
3868 return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
3869}
3870
3871static ssize_t store_user_store(struct kmem_cache *s,
3872 const char *buf, size_t length)
3873{
3874 if (any_slab_objects(s))
3875 return -EBUSY;
3876
3877 s->flags &= ~SLAB_STORE_USER;
3878 if (buf[0] == '1')
3879 s->flags |= SLAB_STORE_USER;
3880 calculate_sizes(s);
3881 return length;
3882}
3883SLAB_ATTR(store_user);
3884
53e15af0
CL
3885static ssize_t validate_show(struct kmem_cache *s, char *buf)
3886{
3887 return 0;
3888}
3889
3890static ssize_t validate_store(struct kmem_cache *s,
3891 const char *buf, size_t length)
3892{
434e245d
CL
3893 int ret = -EINVAL;
3894
3895 if (buf[0] == '1') {
3896 ret = validate_slab_cache(s);
3897 if (ret >= 0)
3898 ret = length;
3899 }
3900 return ret;
53e15af0
CL
3901}
3902SLAB_ATTR(validate);
3903
2086d26a
CL
3904static ssize_t shrink_show(struct kmem_cache *s, char *buf)
3905{
3906 return 0;
3907}
3908
3909static ssize_t shrink_store(struct kmem_cache *s,
3910 const char *buf, size_t length)
3911{
3912 if (buf[0] == '1') {
3913 int rc = kmem_cache_shrink(s);
3914
3915 if (rc)
3916 return rc;
3917 } else
3918 return -EINVAL;
3919 return length;
3920}
3921SLAB_ATTR(shrink);
3922
88a420e4
CL
3923static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
3924{
3925 if (!(s->flags & SLAB_STORE_USER))
3926 return -ENOSYS;
3927 return list_locations(s, buf, TRACK_ALLOC);
3928}
3929SLAB_ATTR_RO(alloc_calls);
3930
3931static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
3932{
3933 if (!(s->flags & SLAB_STORE_USER))
3934 return -ENOSYS;
3935 return list_locations(s, buf, TRACK_FREE);
3936}
3937SLAB_ATTR_RO(free_calls);
3938
81819f0f 3939#ifdef CONFIG_NUMA
9824601e 3940static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
81819f0f 3941{
9824601e 3942 return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
81819f0f
CL
3943}
3944
9824601e 3945static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
81819f0f
CL
3946 const char *buf, size_t length)
3947{
3948 int n = simple_strtoul(buf, NULL, 10);
3949
3950 if (n < 100)
9824601e 3951 s->remote_node_defrag_ratio = n * 10;
81819f0f
CL
3952 return length;
3953}
9824601e 3954SLAB_ATTR(remote_node_defrag_ratio);
81819f0f
CL
3955#endif
3956
8ff12cfc 3957#ifdef CONFIG_SLUB_STATS
8ff12cfc
CL
3958static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
3959{
3960 unsigned long sum = 0;
3961 int cpu;
3962 int len;
3963 int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
3964
3965 if (!data)
3966 return -ENOMEM;
3967
3968 for_each_online_cpu(cpu) {
3969 unsigned x = get_cpu_slab(s, cpu)->stat[si];
3970
3971 data[cpu] = x;
3972 sum += x;
3973 }
3974
3975 len = sprintf(buf, "%lu", sum);
3976
3977 for_each_online_cpu(cpu) {
3978 if (data[cpu] && len < PAGE_SIZE - 20)
3979 len += sprintf(buf + len, " c%d=%u", cpu, data[cpu]);
3980 }
3981 kfree(data);
3982 return len + sprintf(buf + len, "\n");
3983}
3984
3985#define STAT_ATTR(si, text) \
3986static ssize_t text##_show(struct kmem_cache *s, char *buf) \
3987{ \
3988 return show_stat(s, buf, si); \
3989} \
3990SLAB_ATTR_RO(text); \
3991
3992STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
3993STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
3994STAT_ATTR(FREE_FASTPATH, free_fastpath);
3995STAT_ATTR(FREE_SLOWPATH, free_slowpath);
3996STAT_ATTR(FREE_FROZEN, free_frozen);
3997STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
3998STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
3999STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
4000STAT_ATTR(ALLOC_SLAB, alloc_slab);
4001STAT_ATTR(ALLOC_REFILL, alloc_refill);
4002STAT_ATTR(FREE_SLAB, free_slab);
4003STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
4004STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
4005STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
4006STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
4007STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
4008STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
4009
4010#endif
4011
06428780 4012static struct attribute *slab_attrs[] = {
81819f0f
CL
4013 &slab_size_attr.attr,
4014 &object_size_attr.attr,
4015 &objs_per_slab_attr.attr,
4016 &order_attr.attr,
4017 &objects_attr.attr,
4018 &slabs_attr.attr,
4019 &partial_attr.attr,
4020 &cpu_slabs_attr.attr,
4021 &ctor_attr.attr,
81819f0f
CL
4022 &aliases_attr.attr,
4023 &align_attr.attr,
4024 &sanity_checks_attr.attr,
4025 &trace_attr.attr,
4026 &hwcache_align_attr.attr,
4027 &reclaim_account_attr.attr,
4028 &destroy_by_rcu_attr.attr,
4029 &red_zone_attr.attr,
4030 &poison_attr.attr,
4031 &store_user_attr.attr,
53e15af0 4032 &validate_attr.attr,
2086d26a 4033 &shrink_attr.attr,
88a420e4
CL
4034 &alloc_calls_attr.attr,
4035 &free_calls_attr.attr,
81819f0f
CL
4036#ifdef CONFIG_ZONE_DMA
4037 &cache_dma_attr.attr,
4038#endif
4039#ifdef CONFIG_NUMA
9824601e 4040 &remote_node_defrag_ratio_attr.attr,
8ff12cfc
CL
4041#endif
4042#ifdef CONFIG_SLUB_STATS
4043 &alloc_fastpath_attr.attr,
4044 &alloc_slowpath_attr.attr,
4045 &free_fastpath_attr.attr,
4046 &free_slowpath_attr.attr,
4047 &free_frozen_attr.attr,
4048 &free_add_partial_attr.attr,
4049 &free_remove_partial_attr.attr,
4050 &alloc_from_partial_attr.attr,
4051 &alloc_slab_attr.attr,
4052 &alloc_refill_attr.attr,
4053 &free_slab_attr.attr,
4054 &cpuslab_flush_attr.attr,
4055 &deactivate_full_attr.attr,
4056 &deactivate_empty_attr.attr,
4057 &deactivate_to_head_attr.attr,
4058 &deactivate_to_tail_attr.attr,
4059 &deactivate_remote_frees_attr.attr,
81819f0f
CL
4060#endif
4061 NULL
4062};
4063
4064static struct attribute_group slab_attr_group = {
4065 .attrs = slab_attrs,
4066};
4067
4068static ssize_t slab_attr_show(struct kobject *kobj,
4069 struct attribute *attr,
4070 char *buf)
4071{
4072 struct slab_attribute *attribute;
4073 struct kmem_cache *s;
4074 int err;
4075
4076 attribute = to_slab_attr(attr);
4077 s = to_slab(kobj);
4078
4079 if (!attribute->show)
4080 return -EIO;
4081
4082 err = attribute->show(s, buf);
4083
4084 return err;
4085}
4086
4087static ssize_t slab_attr_store(struct kobject *kobj,
4088 struct attribute *attr,
4089 const char *buf, size_t len)
4090{
4091 struct slab_attribute *attribute;
4092 struct kmem_cache *s;
4093 int err;
4094
4095 attribute = to_slab_attr(attr);
4096 s = to_slab(kobj);
4097
4098 if (!attribute->store)
4099 return -EIO;
4100
4101 err = attribute->store(s, buf, len);
4102
4103 return err;
4104}
4105
151c602f
CL
4106static void kmem_cache_release(struct kobject *kobj)
4107{
4108 struct kmem_cache *s = to_slab(kobj);
4109
4110 kfree(s);
4111}
4112
81819f0f
CL
4113static struct sysfs_ops slab_sysfs_ops = {
4114 .show = slab_attr_show,
4115 .store = slab_attr_store,
4116};
4117
4118static struct kobj_type slab_ktype = {
4119 .sysfs_ops = &slab_sysfs_ops,
151c602f 4120 .release = kmem_cache_release
81819f0f
CL
4121};
4122
4123static int uevent_filter(struct kset *kset, struct kobject *kobj)
4124{
4125 struct kobj_type *ktype = get_ktype(kobj);
4126
4127 if (ktype == &slab_ktype)
4128 return 1;
4129 return 0;
4130}
4131
4132static struct kset_uevent_ops slab_uevent_ops = {
4133 .filter = uevent_filter,
4134};
4135
27c3a314 4136static struct kset *slab_kset;
81819f0f
CL
4137
4138#define ID_STR_LENGTH 64
4139
4140/* Create a unique string id for a slab cache:
6446faa2
CL
4141 *
4142 * Format :[flags-]size
81819f0f
CL
4143 */
4144static char *create_unique_id(struct kmem_cache *s)
4145{
4146 char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
4147 char *p = name;
4148
4149 BUG_ON(!name);
4150
4151 *p++ = ':';
4152 /*
4153 * First flags affecting slabcache operations. We will only
4154 * get here for aliasable slabs so we do not need to support
4155 * too many flags. The flags here must cover all flags that
4156 * are matched during merging to guarantee that the id is
4157 * unique.
4158 */
4159 if (s->flags & SLAB_CACHE_DMA)
4160 *p++ = 'd';
4161 if (s->flags & SLAB_RECLAIM_ACCOUNT)
4162 *p++ = 'a';
4163 if (s->flags & SLAB_DEBUG_FREE)
4164 *p++ = 'F';
4165 if (p != name + 1)
4166 *p++ = '-';
4167 p += sprintf(p, "%07d", s->size);
4168 BUG_ON(p > name + ID_STR_LENGTH - 1);
4169 return name;
4170}
4171
4172static int sysfs_slab_add(struct kmem_cache *s)
4173{
4174 int err;
4175 const char *name;
4176 int unmergeable;
4177
4178 if (slab_state < SYSFS)
4179 /* Defer until later */
4180 return 0;
4181
4182 unmergeable = slab_unmergeable(s);
4183 if (unmergeable) {
4184 /*
4185 * Slabcache can never be merged so we can use the name proper.
4186 * This is typically the case for debug situations. In that
4187 * case we can catch duplicate names easily.
4188 */
27c3a314 4189 sysfs_remove_link(&slab_kset->kobj, s->name);
81819f0f
CL
4190 name = s->name;
4191 } else {
4192 /*
4193 * Create a unique name for the slab as a target
4194 * for the symlinks.
4195 */
4196 name = create_unique_id(s);
4197 }
4198
27c3a314 4199 s->kobj.kset = slab_kset;
1eada11c
GKH
4200 err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
4201 if (err) {
4202 kobject_put(&s->kobj);
81819f0f 4203 return err;
1eada11c 4204 }
81819f0f
CL
4205
4206 err = sysfs_create_group(&s->kobj, &slab_attr_group);
4207 if (err)
4208 return err;
4209 kobject_uevent(&s->kobj, KOBJ_ADD);
4210 if (!unmergeable) {
4211 /* Setup first alias */
4212 sysfs_slab_alias(s, s->name);
4213 kfree(name);
4214 }
4215 return 0;
4216}
4217
4218static void sysfs_slab_remove(struct kmem_cache *s)
4219{
4220 kobject_uevent(&s->kobj, KOBJ_REMOVE);
4221 kobject_del(&s->kobj);
151c602f 4222 kobject_put(&s->kobj);
81819f0f
CL
4223}
4224
4225/*
4226 * Need to buffer aliases during bootup until sysfs becomes
4227 * available lest we loose that information.
4228 */
4229struct saved_alias {
4230 struct kmem_cache *s;
4231 const char *name;
4232 struct saved_alias *next;
4233};
4234
5af328a5 4235static struct saved_alias *alias_list;
81819f0f
CL
4236
4237static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
4238{
4239 struct saved_alias *al;
4240
4241 if (slab_state == SYSFS) {
4242 /*
4243 * If we have a leftover link then remove it.
4244 */
27c3a314
GKH
4245 sysfs_remove_link(&slab_kset->kobj, name);
4246 return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
81819f0f
CL
4247 }
4248
4249 al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
4250 if (!al)
4251 return -ENOMEM;
4252
4253 al->s = s;
4254 al->name = name;
4255 al->next = alias_list;
4256 alias_list = al;
4257 return 0;
4258}
4259
4260static int __init slab_sysfs_init(void)
4261{
5b95a4ac 4262 struct kmem_cache *s;
81819f0f
CL
4263 int err;
4264
0ff21e46 4265 slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
27c3a314 4266 if (!slab_kset) {
81819f0f
CL
4267 printk(KERN_ERR "Cannot register slab subsystem.\n");
4268 return -ENOSYS;
4269 }
4270
26a7bd03
CL
4271 slab_state = SYSFS;
4272
5b95a4ac 4273 list_for_each_entry(s, &slab_caches, list) {
26a7bd03 4274 err = sysfs_slab_add(s);
5d540fb7
CL
4275 if (err)
4276 printk(KERN_ERR "SLUB: Unable to add boot slab %s"
4277 " to sysfs\n", s->name);
26a7bd03 4278 }
81819f0f
CL
4279
4280 while (alias_list) {
4281 struct saved_alias *al = alias_list;
4282
4283 alias_list = alias_list->next;
4284 err = sysfs_slab_alias(al->s, al->name);
5d540fb7
CL
4285 if (err)
4286 printk(KERN_ERR "SLUB: Unable to add boot slab alias"
4287 " %s to sysfs\n", s->name);
81819f0f
CL
4288 kfree(al);
4289 }
4290
4291 resiliency_test();
4292 return 0;
4293}
4294
4295__initcall(slab_sysfs_init);
81819f0f 4296#endif
57ed3eda
PE
4297
4298/*
4299 * The /proc/slabinfo ABI
4300 */
158a9624
LT
4301#ifdef CONFIG_SLABINFO
4302
4303ssize_t slabinfo_write(struct file *file, const char __user * buffer,
4304 size_t count, loff_t *ppos)
4305{
4306 return -EINVAL;
4307}
4308
57ed3eda
PE
4309
4310static void print_slabinfo_header(struct seq_file *m)
4311{
4312 seq_puts(m, "slabinfo - version: 2.1\n");
4313 seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
4314 "<objperslab> <pagesperslab>");
4315 seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
4316 seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
4317 seq_putc(m, '\n');
4318}
4319
4320static void *s_start(struct seq_file *m, loff_t *pos)
4321{
4322 loff_t n = *pos;
4323
4324 down_read(&slub_lock);
4325 if (!n)
4326 print_slabinfo_header(m);
4327
4328 return seq_list_start(&slab_caches, *pos);
4329}
4330
4331static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4332{
4333 return seq_list_next(p, &slab_caches, pos);
4334}
4335
4336static void s_stop(struct seq_file *m, void *p)
4337{
4338 up_read(&slub_lock);
4339}
4340
4341static int s_show(struct seq_file *m, void *p)
4342{
4343 unsigned long nr_partials = 0;
4344 unsigned long nr_slabs = 0;
4345 unsigned long nr_inuse = 0;
4346 unsigned long nr_objs;
4347 struct kmem_cache *s;
4348 int node;
4349
4350 s = list_entry(p, struct kmem_cache, list);
4351
4352 for_each_online_node(node) {
4353 struct kmem_cache_node *n = get_node(s, node);
4354
4355 if (!n)
4356 continue;
4357
4358 nr_partials += n->nr_partial;
4359 nr_slabs += atomic_long_read(&n->nr_slabs);
4360 nr_inuse += count_partial(n);
4361 }
4362
4363 nr_objs = nr_slabs * s->objects;
4364 nr_inuse += (nr_slabs - nr_partials) * s->objects;
4365
4366 seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
4367 nr_objs, s->size, s->objects, (1 << s->order));
4368 seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
4369 seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
4370 0UL);
4371 seq_putc(m, '\n');
4372 return 0;
4373}
4374
4375const struct seq_operations slabinfo_op = {
4376 .start = s_start,
4377 .next = s_next,
4378 .stop = s_stop,
4379 .show = s_show,
4380};
4381
158a9624 4382#endif /* CONFIG_SLABINFO */
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