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Commit | Line | Data |
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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 | |
9 | */ | |
10 | ||
11 | #include <linux/mm.h> | |
12 | #include <linux/swap.h> /* struct reclaim_state */ | |
13 | #include <linux/module.h> | |
14 | #include <linux/bit_spinlock.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/bitops.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/proc_fs.h> | |
19 | #include <linux/seq_file.h> | |
20 | #include <linux/kmemcheck.h> | |
21 | #include <linux/cpu.h> | |
22 | #include <linux/cpuset.h> | |
23 | #include <linux/mempolicy.h> | |
24 | #include <linux/ctype.h> | |
25 | #include <linux/debugobjects.h> | |
26 | #include <linux/kallsyms.h> | |
27 | #include <linux/memory.h> | |
28 | #include <linux/math64.h> | |
29 | #include <linux/fault-inject.h> | |
30 | ||
31 | /* | |
32 | * Lock order: | |
33 | * 1. slab_lock(page) | |
34 | * 2. slab->list_lock | |
35 | * | |
36 | * The slab_lock protects operations on the object of a particular | |
37 | * slab and its metadata in the page struct. If the slab lock | |
38 | * has been taken then no allocations nor frees can be performed | |
39 | * on the objects in the slab nor can the slab be added or removed | |
40 | * from the partial or full lists since this would mean modifying | |
41 | * the page_struct of the slab. | |
42 | * | |
43 | * The list_lock protects the partial and full list on each node and | |
44 | * the partial slab counter. If taken then no new slabs may be added or | |
45 | * removed from the lists nor make the number of partial slabs be modified. | |
46 | * (Note that the total number of slabs is an atomic value that may be | |
47 | * modified without taking the list lock). | |
48 | * | |
49 | * The list_lock is a centralized lock and thus we avoid taking it as | |
50 | * much as possible. As long as SLUB does not have to handle partial | |
51 | * slabs, operations can continue without any centralized lock. F.e. | |
52 | * allocating a long series of objects that fill up slabs does not require | |
53 | * the list lock. | |
54 | * | |
55 | * The lock order is sometimes inverted when we are trying to get a slab | |
56 | * off a list. We take the list_lock and then look for a page on the list | |
57 | * to use. While we do that objects in the slabs may be freed. We can | |
58 | * only operate on the slab if we have also taken the slab_lock. So we use | |
59 | * a slab_trylock() on the slab. If trylock was successful then no frees | |
60 | * can occur anymore and we can use the slab for allocations etc. If the | |
61 | * slab_trylock() does not succeed then frees are in progress in the slab and | |
62 | * we must stay away from it for a while since we may cause a bouncing | |
63 | * cacheline if we try to acquire the lock. So go onto the next slab. | |
64 | * If all pages are busy then we may allocate a new slab instead of reusing | |
65 | * a partial slab. A new slab has noone operating on it and thus there is | |
66 | * no danger of cacheline contention. | |
67 | * | |
68 | * Interrupts are disabled during allocation and deallocation in order to | |
69 | * make the slab allocator safe to use in the context of an irq. In addition | |
70 | * interrupts are disabled to ensure that the processor does not change | |
71 | * while handling per_cpu slabs, due to kernel preemption. | |
72 | * | |
73 | * SLUB assigns one slab for allocation to each processor. | |
74 | * Allocations only occur from these slabs called cpu slabs. | |
75 | * | |
76 | * Slabs with free elements are kept on a partial list and during regular | |
77 | * operations no list for full slabs is used. If an object in a full slab is | |
78 | * freed then the slab will show up again on the partial lists. | |
79 | * We track full slabs for debugging purposes though because otherwise we | |
80 | * cannot scan all objects. | |
81 | * | |
82 | * Slabs are freed when they become empty. Teardown and setup is | |
83 | * minimal so we rely on the page allocators per cpu caches for | |
84 | * fast frees and allocs. | |
85 | * | |
86 | * Overloading of page flags that are otherwise used for LRU management. | |
87 | * | |
88 | * PageActive The slab is frozen and exempt from list processing. | |
89 | * This means that the slab is dedicated to a purpose | |
90 | * such as satisfying allocations for a specific | |
91 | * processor. Objects may be freed in the slab while | |
92 | * it is frozen but slab_free will then skip the usual | |
93 | * list operations. It is up to the processor holding | |
94 | * the slab to integrate the slab into the slab lists | |
95 | * when the slab is no longer needed. | |
96 | * | |
97 | * One use of this flag is to mark slabs that are | |
98 | * used for allocations. Then such a slab becomes a cpu | |
99 | * slab. The cpu slab may be equipped with an additional | |
100 | * freelist that allows lockless access to | |
101 | * free objects in addition to the regular freelist | |
102 | * that requires the slab lock. | |
103 | * | |
104 | * PageError Slab requires special handling due to debug | |
105 | * options set. This moves slab handling out of | |
106 | * the fast path and disables lockless freelists. | |
107 | */ | |
108 | ||
109 | #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
110 | SLAB_TRACE | SLAB_DEBUG_FREE) | |
111 | ||
112 | static inline int kmem_cache_debug(struct kmem_cache *s) | |
113 | { | |
114 | #ifdef CONFIG_SLUB_DEBUG | |
115 | return unlikely(s->flags & SLAB_DEBUG_FLAGS); | |
116 | #else | |
117 | return 0; | |
118 | #endif | |
119 | } | |
120 | ||
121 | /* | |
122 | * Issues still to be resolved: | |
123 | * | |
124 | * - Support PAGE_ALLOC_DEBUG. Should be easy to do. | |
125 | * | |
126 | * - Variable sizing of the per node arrays | |
127 | */ | |
128 | ||
129 | /* Enable to test recovery from slab corruption on boot */ | |
130 | #undef SLUB_RESILIENCY_TEST | |
131 | ||
132 | /* | |
133 | * Mininum number of partial slabs. These will be left on the partial | |
134 | * lists even if they are empty. kmem_cache_shrink may reclaim them. | |
135 | */ | |
136 | #define MIN_PARTIAL 5 | |
137 | ||
138 | /* | |
139 | * Maximum number of desirable partial slabs. | |
140 | * The existence of more partial slabs makes kmem_cache_shrink | |
141 | * sort the partial list by the number of objects in the. | |
142 | */ | |
143 | #define MAX_PARTIAL 10 | |
144 | ||
145 | #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \ | |
146 | SLAB_POISON | SLAB_STORE_USER) | |
147 | ||
148 | /* | |
149 | * Debugging flags that require metadata to be stored in the slab. These get | |
150 | * disabled when slub_debug=O is used and a cache's min order increases with | |
151 | * metadata. | |
152 | */ | |
153 | #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) | |
154 | ||
155 | /* | |
156 | * Set of flags that will prevent slab merging | |
157 | */ | |
158 | #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
159 | SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ | |
160 | SLAB_FAILSLAB) | |
161 | ||
162 | #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ | |
163 | SLAB_CACHE_DMA | SLAB_NOTRACK) | |
164 | ||
165 | #define OO_SHIFT 16 | |
166 | #define OO_MASK ((1 << OO_SHIFT) - 1) | |
167 | #define MAX_OBJS_PER_PAGE 65535 /* since page.objects is u16 */ | |
168 | ||
169 | /* Internal SLUB flags */ | |
170 | #define __OBJECT_POISON 0x80000000UL /* Poison object */ | |
171 | ||
172 | static int kmem_size = sizeof(struct kmem_cache); | |
173 | ||
174 | #ifdef CONFIG_SMP | |
175 | static struct notifier_block slab_notifier; | |
176 | #endif | |
177 | ||
178 | static enum { | |
179 | DOWN, /* No slab functionality available */ | |
180 | PARTIAL, /* Kmem_cache_node works */ | |
181 | UP, /* Everything works but does not show up in sysfs */ | |
182 | SYSFS /* Sysfs up */ | |
183 | } slab_state = DOWN; | |
184 | ||
185 | /* A list of all slab caches on the system */ | |
186 | static DECLARE_RWSEM(slub_lock); | |
187 | static LIST_HEAD(slab_caches); | |
188 | ||
189 | /* | |
190 | * Tracking user of a slab. | |
191 | */ | |
192 | struct track { | |
193 | unsigned long addr; /* Called from address */ | |
194 | int cpu; /* Was running on cpu */ | |
195 | int pid; /* Pid context */ | |
196 | unsigned long when; /* When did the operation occur */ | |
197 | }; | |
198 | ||
199 | enum track_item { TRACK_ALLOC, TRACK_FREE }; | |
200 | ||
201 | #ifdef CONFIG_SYSFS | |
202 | static int sysfs_slab_add(struct kmem_cache *); | |
203 | static int sysfs_slab_alias(struct kmem_cache *, const char *); | |
204 | static void sysfs_slab_remove(struct kmem_cache *); | |
205 | ||
206 | #else | |
207 | static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; } | |
208 | static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) | |
209 | { return 0; } | |
210 | static inline void sysfs_slab_remove(struct kmem_cache *s) | |
211 | { | |
212 | kfree(s->name); | |
213 | kfree(s); | |
214 | } | |
215 | ||
216 | #endif | |
217 | ||
218 | static inline void stat(struct kmem_cache *s, enum stat_item si) | |
219 | { | |
220 | #ifdef CONFIG_SLUB_STATS | |
221 | __this_cpu_inc(s->cpu_slab->stat[si]); | |
222 | #endif | |
223 | } | |
224 | ||
225 | /******************************************************************** | |
226 | * Core slab cache functions | |
227 | *******************************************************************/ | |
228 | ||
229 | int slab_is_available(void) | |
230 | { | |
231 | return slab_state >= UP; | |
232 | } | |
233 | ||
234 | static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) | |
235 | { | |
236 | return s->node[node]; | |
237 | } | |
238 | ||
239 | /* Verify that a pointer has an address that is valid within a slab page */ | |
240 | static inline int check_valid_pointer(struct kmem_cache *s, | |
241 | struct page *page, const void *object) | |
242 | { | |
243 | void *base; | |
244 | ||
245 | if (!object) | |
246 | return 1; | |
247 | ||
248 | base = page_address(page); | |
249 | if (object < base || object >= base + page->objects * s->size || | |
250 | (object - base) % s->size) { | |
251 | return 0; | |
252 | } | |
253 | ||
254 | return 1; | |
255 | } | |
256 | ||
257 | static inline void *get_freepointer(struct kmem_cache *s, void *object) | |
258 | { | |
259 | return *(void **)(object + s->offset); | |
260 | } | |
261 | ||
262 | static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) | |
263 | { | |
264 | *(void **)(object + s->offset) = fp; | |
265 | } | |
266 | ||
267 | /* Loop over all objects in a slab */ | |
268 | #define for_each_object(__p, __s, __addr, __objects) \ | |
269 | for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\ | |
270 | __p += (__s)->size) | |
271 | ||
272 | /* Scan freelist */ | |
273 | #define for_each_free_object(__p, __s, __free) \ | |
274 | for (__p = (__free); __p; __p = get_freepointer((__s), __p)) | |
275 | ||
276 | /* Determine object index from a given position */ | |
277 | static inline int slab_index(void *p, struct kmem_cache *s, void *addr) | |
278 | { | |
279 | return (p - addr) / s->size; | |
280 | } | |
281 | ||
282 | static inline struct kmem_cache_order_objects oo_make(int order, | |
283 | unsigned long size) | |
284 | { | |
285 | struct kmem_cache_order_objects x = { | |
286 | (order << OO_SHIFT) + (PAGE_SIZE << order) / size | |
287 | }; | |
288 | ||
289 | return x; | |
290 | } | |
291 | ||
292 | static inline int oo_order(struct kmem_cache_order_objects x) | |
293 | { | |
294 | return x.x >> OO_SHIFT; | |
295 | } | |
296 | ||
297 | static inline int oo_objects(struct kmem_cache_order_objects x) | |
298 | { | |
299 | return x.x & OO_MASK; | |
300 | } | |
301 | ||
302 | #ifdef CONFIG_SLUB_DEBUG | |
303 | /* | |
304 | * Debug settings: | |
305 | */ | |
306 | #ifdef CONFIG_SLUB_DEBUG_ON | |
307 | static int slub_debug = DEBUG_DEFAULT_FLAGS; | |
308 | #else | |
309 | static int slub_debug; | |
310 | #endif | |
311 | ||
312 | static char *slub_debug_slabs; | |
313 | static int disable_higher_order_debug; | |
314 | ||
315 | /* | |
316 | * Object debugging | |
317 | */ | |
318 | static void print_section(char *text, u8 *addr, unsigned int length) | |
319 | { | |
320 | int i, offset; | |
321 | int newline = 1; | |
322 | char ascii[17]; | |
323 | ||
324 | ascii[16] = 0; | |
325 | ||
326 | for (i = 0; i < length; i++) { | |
327 | if (newline) { | |
328 | printk(KERN_ERR "%8s 0x%p: ", text, addr + i); | |
329 | newline = 0; | |
330 | } | |
331 | printk(KERN_CONT " %02x", addr[i]); | |
332 | offset = i % 16; | |
333 | ascii[offset] = isgraph(addr[i]) ? addr[i] : '.'; | |
334 | if (offset == 15) { | |
335 | printk(KERN_CONT " %s\n", ascii); | |
336 | newline = 1; | |
337 | } | |
338 | } | |
339 | if (!newline) { | |
340 | i %= 16; | |
341 | while (i < 16) { | |
342 | printk(KERN_CONT " "); | |
343 | ascii[i] = ' '; | |
344 | i++; | |
345 | } | |
346 | printk(KERN_CONT " %s\n", ascii); | |
347 | } | |
348 | } | |
349 | ||
350 | static struct track *get_track(struct kmem_cache *s, void *object, | |
351 | enum track_item alloc) | |
352 | { | |
353 | struct track *p; | |
354 | ||
355 | if (s->offset) | |
356 | p = object + s->offset + sizeof(void *); | |
357 | else | |
358 | p = object + s->inuse; | |
359 | ||
360 | return p + alloc; | |
361 | } | |
362 | ||
363 | static void set_track(struct kmem_cache *s, void *object, | |
364 | enum track_item alloc, unsigned long addr) | |
365 | { | |
366 | struct track *p = get_track(s, object, alloc); | |
367 | ||
368 | if (addr) { | |
369 | p->addr = addr; | |
370 | p->cpu = smp_processor_id(); | |
371 | p->pid = current->pid; | |
372 | p->when = jiffies; | |
373 | } else | |
374 | memset(p, 0, sizeof(struct track)); | |
375 | } | |
376 | ||
377 | static void init_tracking(struct kmem_cache *s, void *object) | |
378 | { | |
379 | if (!(s->flags & SLAB_STORE_USER)) | |
380 | return; | |
381 | ||
382 | set_track(s, object, TRACK_FREE, 0UL); | |
383 | set_track(s, object, TRACK_ALLOC, 0UL); | |
384 | } | |
385 | ||
386 | static void print_track(const char *s, struct track *t) | |
387 | { | |
388 | if (!t->addr) | |
389 | return; | |
390 | ||
391 | printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n", | |
392 | s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid); | |
393 | } | |
394 | ||
395 | static void print_tracking(struct kmem_cache *s, void *object) | |
396 | { | |
397 | if (!(s->flags & SLAB_STORE_USER)) | |
398 | return; | |
399 | ||
400 | print_track("Allocated", get_track(s, object, TRACK_ALLOC)); | |
401 | print_track("Freed", get_track(s, object, TRACK_FREE)); | |
402 | } | |
403 | ||
404 | static void print_page_info(struct page *page) | |
405 | { | |
406 | printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n", | |
407 | page, page->objects, page->inuse, page->freelist, page->flags); | |
408 | ||
409 | } | |
410 | ||
411 | static void slab_bug(struct kmem_cache *s, char *fmt, ...) | |
412 | { | |
413 | va_list args; | |
414 | char buf[100]; | |
415 | ||
416 | va_start(args, fmt); | |
417 | vsnprintf(buf, sizeof(buf), fmt, args); | |
418 | va_end(args); | |
419 | printk(KERN_ERR "========================================" | |
420 | "=====================================\n"); | |
421 | printk(KERN_ERR "BUG %s: %s\n", s->name, buf); | |
422 | printk(KERN_ERR "----------------------------------------" | |
423 | "-------------------------------------\n\n"); | |
424 | } | |
425 | ||
426 | static void slab_fix(struct kmem_cache *s, char *fmt, ...) | |
427 | { | |
428 | va_list args; | |
429 | char buf[100]; | |
430 | ||
431 | va_start(args, fmt); | |
432 | vsnprintf(buf, sizeof(buf), fmt, args); | |
433 | va_end(args); | |
434 | printk(KERN_ERR "FIX %s: %s\n", s->name, buf); | |
435 | } | |
436 | ||
437 | static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p) | |
438 | { | |
439 | unsigned int off; /* Offset of last byte */ | |
440 | u8 *addr = page_address(page); | |
441 | ||
442 | print_tracking(s, p); | |
443 | ||
444 | print_page_info(page); | |
445 | ||
446 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n", | |
447 | p, p - addr, get_freepointer(s, p)); | |
448 | ||
449 | if (p > addr + 16) | |
450 | print_section("Bytes b4", p - 16, 16); | |
451 | ||
452 | print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE)); | |
453 | ||
454 | if (s->flags & SLAB_RED_ZONE) | |
455 | print_section("Redzone", p + s->objsize, | |
456 | s->inuse - s->objsize); | |
457 | ||
458 | if (s->offset) | |
459 | off = s->offset + sizeof(void *); | |
460 | else | |
461 | off = s->inuse; | |
462 | ||
463 | if (s->flags & SLAB_STORE_USER) | |
464 | off += 2 * sizeof(struct track); | |
465 | ||
466 | if (off != s->size) | |
467 | /* Beginning of the filler is the free pointer */ | |
468 | print_section("Padding", p + off, s->size - off); | |
469 | ||
470 | dump_stack(); | |
471 | } | |
472 | ||
473 | static void object_err(struct kmem_cache *s, struct page *page, | |
474 | u8 *object, char *reason) | |
475 | { | |
476 | slab_bug(s, "%s", reason); | |
477 | print_trailer(s, page, object); | |
478 | } | |
479 | ||
480 | static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...) | |
481 | { | |
482 | va_list args; | |
483 | char buf[100]; | |
484 | ||
485 | va_start(args, fmt); | |
486 | vsnprintf(buf, sizeof(buf), fmt, args); | |
487 | va_end(args); | |
488 | slab_bug(s, "%s", buf); | |
489 | print_page_info(page); | |
490 | dump_stack(); | |
491 | } | |
492 | ||
493 | static void init_object(struct kmem_cache *s, void *object, u8 val) | |
494 | { | |
495 | u8 *p = object; | |
496 | ||
497 | if (s->flags & __OBJECT_POISON) { | |
498 | memset(p, POISON_FREE, s->objsize - 1); | |
499 | p[s->objsize - 1] = POISON_END; | |
500 | } | |
501 | ||
502 | if (s->flags & SLAB_RED_ZONE) | |
503 | memset(p + s->objsize, val, s->inuse - s->objsize); | |
504 | } | |
505 | ||
506 | static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes) | |
507 | { | |
508 | while (bytes) { | |
509 | if (*start != (u8)value) | |
510 | return start; | |
511 | start++; | |
512 | bytes--; | |
513 | } | |
514 | return NULL; | |
515 | } | |
516 | ||
517 | static void restore_bytes(struct kmem_cache *s, char *message, u8 data, | |
518 | void *from, void *to) | |
519 | { | |
520 | slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data); | |
521 | memset(from, data, to - from); | |
522 | } | |
523 | ||
524 | static int check_bytes_and_report(struct kmem_cache *s, struct page *page, | |
525 | u8 *object, char *what, | |
526 | u8 *start, unsigned int value, unsigned int bytes) | |
527 | { | |
528 | u8 *fault; | |
529 | u8 *end; | |
530 | ||
531 | fault = check_bytes(start, value, bytes); | |
532 | if (!fault) | |
533 | return 1; | |
534 | ||
535 | end = start + bytes; | |
536 | while (end > fault && end[-1] == value) | |
537 | end--; | |
538 | ||
539 | slab_bug(s, "%s overwritten", what); | |
540 | printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n", | |
541 | fault, end - 1, fault[0], value); | |
542 | print_trailer(s, page, object); | |
543 | ||
544 | restore_bytes(s, what, value, fault, end); | |
545 | return 0; | |
546 | } | |
547 | ||
548 | /* | |
549 | * Object layout: | |
550 | * | |
551 | * object address | |
552 | * Bytes of the object to be managed. | |
553 | * If the freepointer may overlay the object then the free | |
554 | * pointer is the first word of the object. | |
555 | * | |
556 | * Poisoning uses 0x6b (POISON_FREE) and the last byte is | |
557 | * 0xa5 (POISON_END) | |
558 | * | |
559 | * object + s->objsize | |
560 | * Padding to reach word boundary. This is also used for Redzoning. | |
561 | * Padding is extended by another word if Redzoning is enabled and | |
562 | * objsize == inuse. | |
563 | * | |
564 | * We fill with 0xbb (RED_INACTIVE) for inactive objects and with | |
565 | * 0xcc (RED_ACTIVE) for objects in use. | |
566 | * | |
567 | * object + s->inuse | |
568 | * Meta data starts here. | |
569 | * | |
570 | * A. Free pointer (if we cannot overwrite object on free) | |
571 | * B. Tracking data for SLAB_STORE_USER | |
572 | * C. Padding to reach required alignment boundary or at mininum | |
573 | * one word if debugging is on to be able to detect writes | |
574 | * before the word boundary. | |
575 | * | |
576 | * Padding is done using 0x5a (POISON_INUSE) | |
577 | * | |
578 | * object + s->size | |
579 | * Nothing is used beyond s->size. | |
580 | * | |
581 | * If slabcaches are merged then the objsize and inuse boundaries are mostly | |
582 | * ignored. And therefore no slab options that rely on these boundaries | |
583 | * may be used with merged slabcaches. | |
584 | */ | |
585 | ||
586 | static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p) | |
587 | { | |
588 | unsigned long off = s->inuse; /* The end of info */ | |
589 | ||
590 | if (s->offset) | |
591 | /* Freepointer is placed after the object. */ | |
592 | off += sizeof(void *); | |
593 | ||
594 | if (s->flags & SLAB_STORE_USER) | |
595 | /* We also have user information there */ | |
596 | off += 2 * sizeof(struct track); | |
597 | ||
598 | if (s->size == off) | |
599 | return 1; | |
600 | ||
601 | return check_bytes_and_report(s, page, p, "Object padding", | |
602 | p + off, POISON_INUSE, s->size - off); | |
603 | } | |
604 | ||
605 | /* Check the pad bytes at the end of a slab page */ | |
606 | static int slab_pad_check(struct kmem_cache *s, struct page *page) | |
607 | { | |
608 | u8 *start; | |
609 | u8 *fault; | |
610 | u8 *end; | |
611 | int length; | |
612 | int remainder; | |
613 | ||
614 | if (!(s->flags & SLAB_POISON)) | |
615 | return 1; | |
616 | ||
617 | start = page_address(page); | |
618 | length = (PAGE_SIZE << compound_order(page)); | |
619 | end = start + length; | |
620 | remainder = length % s->size; | |
621 | if (!remainder) | |
622 | return 1; | |
623 | ||
624 | fault = check_bytes(end - remainder, POISON_INUSE, remainder); | |
625 | if (!fault) | |
626 | return 1; | |
627 | while (end > fault && end[-1] == POISON_INUSE) | |
628 | end--; | |
629 | ||
630 | slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1); | |
631 | print_section("Padding", end - remainder, remainder); | |
632 | ||
633 | restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end); | |
634 | return 0; | |
635 | } | |
636 | ||
637 | static int check_object(struct kmem_cache *s, struct page *page, | |
638 | void *object, u8 val) | |
639 | { | |
640 | u8 *p = object; | |
641 | u8 *endobject = object + s->objsize; | |
642 | ||
643 | if (s->flags & SLAB_RED_ZONE) { | |
644 | if (!check_bytes_and_report(s, page, object, "Redzone", | |
645 | endobject, val, s->inuse - s->objsize)) | |
646 | return 0; | |
647 | } else { | |
648 | if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) { | |
649 | check_bytes_and_report(s, page, p, "Alignment padding", | |
650 | endobject, POISON_INUSE, s->inuse - s->objsize); | |
651 | } | |
652 | } | |
653 | ||
654 | if (s->flags & SLAB_POISON) { | |
655 | if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) && | |
656 | (!check_bytes_and_report(s, page, p, "Poison", p, | |
657 | POISON_FREE, s->objsize - 1) || | |
658 | !check_bytes_and_report(s, page, p, "Poison", | |
659 | p + s->objsize - 1, POISON_END, 1))) | |
660 | return 0; | |
661 | /* | |
662 | * check_pad_bytes cleans up on its own. | |
663 | */ | |
664 | check_pad_bytes(s, page, p); | |
665 | } | |
666 | ||
667 | if (!s->offset && val == SLUB_RED_ACTIVE) | |
668 | /* | |
669 | * Object and freepointer overlap. Cannot check | |
670 | * freepointer while object is allocated. | |
671 | */ | |
672 | return 1; | |
673 | ||
674 | /* Check free pointer validity */ | |
675 | if (!check_valid_pointer(s, page, get_freepointer(s, p))) { | |
676 | object_err(s, page, p, "Freepointer corrupt"); | |
677 | /* | |
678 | * No choice but to zap it and thus lose the remainder | |
679 | * of the free objects in this slab. May cause | |
680 | * another error because the object count is now wrong. | |
681 | */ | |
682 | set_freepointer(s, p, NULL); | |
683 | return 0; | |
684 | } | |
685 | return 1; | |
686 | } | |
687 | ||
688 | static int check_slab(struct kmem_cache *s, struct page *page) | |
689 | { | |
690 | int maxobj; | |
691 | ||
692 | VM_BUG_ON(!irqs_disabled()); | |
693 | ||
694 | if (!PageSlab(page)) { | |
695 | slab_err(s, page, "Not a valid slab page"); | |
696 | return 0; | |
697 | } | |
698 | ||
699 | maxobj = (PAGE_SIZE << compound_order(page)) / s->size; | |
700 | if (page->objects > maxobj) { | |
701 | slab_err(s, page, "objects %u > max %u", | |
702 | s->name, page->objects, maxobj); | |
703 | return 0; | |
704 | } | |
705 | if (page->inuse > page->objects) { | |
706 | slab_err(s, page, "inuse %u > max %u", | |
707 | s->name, page->inuse, page->objects); | |
708 | return 0; | |
709 | } | |
710 | /* Slab_pad_check fixes things up after itself */ | |
711 | slab_pad_check(s, page); | |
712 | return 1; | |
713 | } | |
714 | ||
715 | /* | |
716 | * Determine if a certain object on a page is on the freelist. Must hold the | |
717 | * slab lock to guarantee that the chains are in a consistent state. | |
718 | */ | |
719 | static int on_freelist(struct kmem_cache *s, struct page *page, void *search) | |
720 | { | |
721 | int nr = 0; | |
722 | void *fp = page->freelist; | |
723 | void *object = NULL; | |
724 | unsigned long max_objects; | |
725 | ||
726 | while (fp && nr <= page->objects) { | |
727 | if (fp == search) | |
728 | return 1; | |
729 | if (!check_valid_pointer(s, page, fp)) { | |
730 | if (object) { | |
731 | object_err(s, page, object, | |
732 | "Freechain corrupt"); | |
733 | set_freepointer(s, object, NULL); | |
734 | break; | |
735 | } else { | |
736 | slab_err(s, page, "Freepointer corrupt"); | |
737 | page->freelist = NULL; | |
738 | page->inuse = page->objects; | |
739 | slab_fix(s, "Freelist cleared"); | |
740 | return 0; | |
741 | } | |
742 | break; | |
743 | } | |
744 | object = fp; | |
745 | fp = get_freepointer(s, object); | |
746 | nr++; | |
747 | } | |
748 | ||
749 | max_objects = (PAGE_SIZE << compound_order(page)) / s->size; | |
750 | if (max_objects > MAX_OBJS_PER_PAGE) | |
751 | max_objects = MAX_OBJS_PER_PAGE; | |
752 | ||
753 | if (page->objects != max_objects) { | |
754 | slab_err(s, page, "Wrong number of objects. Found %d but " | |
755 | "should be %d", page->objects, max_objects); | |
756 | page->objects = max_objects; | |
757 | slab_fix(s, "Number of objects adjusted."); | |
758 | } | |
759 | if (page->inuse != page->objects - nr) { | |
760 | slab_err(s, page, "Wrong object count. Counter is %d but " | |
761 | "counted were %d", page->inuse, page->objects - nr); | |
762 | page->inuse = page->objects - nr; | |
763 | slab_fix(s, "Object count adjusted."); | |
764 | } | |
765 | return search == NULL; | |
766 | } | |
767 | ||
768 | static void trace(struct kmem_cache *s, struct page *page, void *object, | |
769 | int alloc) | |
770 | { | |
771 | if (s->flags & SLAB_TRACE) { | |
772 | printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n", | |
773 | s->name, | |
774 | alloc ? "alloc" : "free", | |
775 | object, page->inuse, | |
776 | page->freelist); | |
777 | ||
778 | if (!alloc) | |
779 | print_section("Object", (void *)object, s->objsize); | |
780 | ||
781 | dump_stack(); | |
782 | } | |
783 | } | |
784 | ||
785 | /* | |
786 | * Hooks for other subsystems that check memory allocations. In a typical | |
787 | * production configuration these hooks all should produce no code at all. | |
788 | */ | |
789 | static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) | |
790 | { | |
791 | flags &= gfp_allowed_mask; | |
792 | lockdep_trace_alloc(flags); | |
793 | might_sleep_if(flags & __GFP_WAIT); | |
794 | ||
795 | return should_failslab(s->objsize, flags, s->flags); | |
796 | } | |
797 | ||
798 | static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object) | |
799 | { | |
800 | flags &= gfp_allowed_mask; | |
801 | kmemcheck_slab_alloc(s, flags, object, s->objsize); | |
802 | kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags); | |
803 | } | |
804 | ||
805 | static inline void slab_free_hook(struct kmem_cache *s, void *x) | |
806 | { | |
807 | kmemleak_free_recursive(x, s->flags); | |
808 | } | |
809 | ||
810 | static inline void slab_free_hook_irq(struct kmem_cache *s, void *object) | |
811 | { | |
812 | kmemcheck_slab_free(s, object, s->objsize); | |
813 | debug_check_no_locks_freed(object, s->objsize); | |
814 | if (!(s->flags & SLAB_DEBUG_OBJECTS)) | |
815 | debug_check_no_obj_freed(object, s->objsize); | |
816 | } | |
817 | ||
818 | /* | |
819 | * Tracking of fully allocated slabs for debugging purposes. | |
820 | */ | |
821 | static void add_full(struct kmem_cache_node *n, struct page *page) | |
822 | { | |
823 | spin_lock(&n->list_lock); | |
824 | list_add(&page->lru, &n->full); | |
825 | spin_unlock(&n->list_lock); | |
826 | } | |
827 | ||
828 | static void remove_full(struct kmem_cache *s, struct page *page) | |
829 | { | |
830 | struct kmem_cache_node *n; | |
831 | ||
832 | if (!(s->flags & SLAB_STORE_USER)) | |
833 | return; | |
834 | ||
835 | n = get_node(s, page_to_nid(page)); | |
836 | ||
837 | spin_lock(&n->list_lock); | |
838 | list_del(&page->lru); | |
839 | spin_unlock(&n->list_lock); | |
840 | } | |
841 | ||
842 | /* Tracking of the number of slabs for debugging purposes */ | |
843 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) | |
844 | { | |
845 | struct kmem_cache_node *n = get_node(s, node); | |
846 | ||
847 | return atomic_long_read(&n->nr_slabs); | |
848 | } | |
849 | ||
850 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) | |
851 | { | |
852 | return atomic_long_read(&n->nr_slabs); | |
853 | } | |
854 | ||
855 | static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects) | |
856 | { | |
857 | struct kmem_cache_node *n = get_node(s, node); | |
858 | ||
859 | /* | |
860 | * May be called early in order to allocate a slab for the | |
861 | * kmem_cache_node structure. Solve the chicken-egg | |
862 | * dilemma by deferring the increment of the count during | |
863 | * bootstrap (see early_kmem_cache_node_alloc). | |
864 | */ | |
865 | if (n) { | |
866 | atomic_long_inc(&n->nr_slabs); | |
867 | atomic_long_add(objects, &n->total_objects); | |
868 | } | |
869 | } | |
870 | static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects) | |
871 | { | |
872 | struct kmem_cache_node *n = get_node(s, node); | |
873 | ||
874 | atomic_long_dec(&n->nr_slabs); | |
875 | atomic_long_sub(objects, &n->total_objects); | |
876 | } | |
877 | ||
878 | /* Object debug checks for alloc/free paths */ | |
879 | static void setup_object_debug(struct kmem_cache *s, struct page *page, | |
880 | void *object) | |
881 | { | |
882 | if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))) | |
883 | return; | |
884 | ||
885 | init_object(s, object, SLUB_RED_INACTIVE); | |
886 | init_tracking(s, object); | |
887 | } | |
888 | ||
889 | static noinline int alloc_debug_processing(struct kmem_cache *s, struct page *page, | |
890 | void *object, unsigned long addr) | |
891 | { | |
892 | if (!check_slab(s, page)) | |
893 | goto bad; | |
894 | ||
895 | if (!on_freelist(s, page, object)) { | |
896 | object_err(s, page, object, "Object already allocated"); | |
897 | goto bad; | |
898 | } | |
899 | ||
900 | if (!check_valid_pointer(s, page, object)) { | |
901 | object_err(s, page, object, "Freelist Pointer check fails"); | |
902 | goto bad; | |
903 | } | |
904 | ||
905 | if (!check_object(s, page, object, SLUB_RED_INACTIVE)) | |
906 | goto bad; | |
907 | ||
908 | /* Success perform special debug activities for allocs */ | |
909 | if (s->flags & SLAB_STORE_USER) | |
910 | set_track(s, object, TRACK_ALLOC, addr); | |
911 | trace(s, page, object, 1); | |
912 | init_object(s, object, SLUB_RED_ACTIVE); | |
913 | return 1; | |
914 | ||
915 | bad: | |
916 | if (PageSlab(page)) { | |
917 | /* | |
918 | * If this is a slab page then lets do the best we can | |
919 | * to avoid issues in the future. Marking all objects | |
920 | * as used avoids touching the remaining objects. | |
921 | */ | |
922 | slab_fix(s, "Marking all objects used"); | |
923 | page->inuse = page->objects; | |
924 | page->freelist = NULL; | |
925 | } | |
926 | return 0; | |
927 | } | |
928 | ||
929 | static noinline int free_debug_processing(struct kmem_cache *s, | |
930 | struct page *page, void *object, unsigned long addr) | |
931 | { | |
932 | if (!check_slab(s, page)) | |
933 | goto fail; | |
934 | ||
935 | if (!check_valid_pointer(s, page, object)) { | |
936 | slab_err(s, page, "Invalid object pointer 0x%p", object); | |
937 | goto fail; | |
938 | } | |
939 | ||
940 | if (on_freelist(s, page, object)) { | |
941 | object_err(s, page, object, "Object already free"); | |
942 | goto fail; | |
943 | } | |
944 | ||
945 | if (!check_object(s, page, object, SLUB_RED_ACTIVE)) | |
946 | return 0; | |
947 | ||
948 | if (unlikely(s != page->slab)) { | |
949 | if (!PageSlab(page)) { | |
950 | slab_err(s, page, "Attempt to free object(0x%p) " | |
951 | "outside of slab", object); | |
952 | } else if (!page->slab) { | |
953 | printk(KERN_ERR | |
954 | "SLUB <none>: no slab for object 0x%p.\n", | |
955 | object); | |
956 | dump_stack(); | |
957 | } else | |
958 | object_err(s, page, object, | |
959 | "page slab pointer corrupt."); | |
960 | goto fail; | |
961 | } | |
962 | ||
963 | /* Special debug activities for freeing objects */ | |
964 | if (!PageSlubFrozen(page) && !page->freelist) | |
965 | remove_full(s, page); | |
966 | if (s->flags & SLAB_STORE_USER) | |
967 | set_track(s, object, TRACK_FREE, addr); | |
968 | trace(s, page, object, 0); | |
969 | init_object(s, object, SLUB_RED_INACTIVE); | |
970 | return 1; | |
971 | ||
972 | fail: | |
973 | slab_fix(s, "Object at 0x%p not freed", object); | |
974 | return 0; | |
975 | } | |
976 | ||
977 | static int __init setup_slub_debug(char *str) | |
978 | { | |
979 | slub_debug = DEBUG_DEFAULT_FLAGS; | |
980 | if (*str++ != '=' || !*str) | |
981 | /* | |
982 | * No options specified. Switch on full debugging. | |
983 | */ | |
984 | goto out; | |
985 | ||
986 | if (*str == ',') | |
987 | /* | |
988 | * No options but restriction on slabs. This means full | |
989 | * debugging for slabs matching a pattern. | |
990 | */ | |
991 | goto check_slabs; | |
992 | ||
993 | if (tolower(*str) == 'o') { | |
994 | /* | |
995 | * Avoid enabling debugging on caches if its minimum order | |
996 | * would increase as a result. | |
997 | */ | |
998 | disable_higher_order_debug = 1; | |
999 | goto out; | |
1000 | } | |
1001 | ||
1002 | slub_debug = 0; | |
1003 | if (*str == '-') | |
1004 | /* | |
1005 | * Switch off all debugging measures. | |
1006 | */ | |
1007 | goto out; | |
1008 | ||
1009 | /* | |
1010 | * Determine which debug features should be switched on | |
1011 | */ | |
1012 | for (; *str && *str != ','; str++) { | |
1013 | switch (tolower(*str)) { | |
1014 | case 'f': | |
1015 | slub_debug |= SLAB_DEBUG_FREE; | |
1016 | break; | |
1017 | case 'z': | |
1018 | slub_debug |= SLAB_RED_ZONE; | |
1019 | break; | |
1020 | case 'p': | |
1021 | slub_debug |= SLAB_POISON; | |
1022 | break; | |
1023 | case 'u': | |
1024 | slub_debug |= SLAB_STORE_USER; | |
1025 | break; | |
1026 | case 't': | |
1027 | slub_debug |= SLAB_TRACE; | |
1028 | break; | |
1029 | case 'a': | |
1030 | slub_debug |= SLAB_FAILSLAB; | |
1031 | break; | |
1032 | default: | |
1033 | printk(KERN_ERR "slub_debug option '%c' " | |
1034 | "unknown. skipped\n", *str); | |
1035 | } | |
1036 | } | |
1037 | ||
1038 | check_slabs: | |
1039 | if (*str == ',') | |
1040 | slub_debug_slabs = str + 1; | |
1041 | out: | |
1042 | return 1; | |
1043 | } | |
1044 | ||
1045 | __setup("slub_debug", setup_slub_debug); | |
1046 | ||
1047 | static unsigned long kmem_cache_flags(unsigned long objsize, | |
1048 | unsigned long flags, const char *name, | |
1049 | void (*ctor)(void *)) | |
1050 | { | |
1051 | /* | |
1052 | * Enable debugging if selected on the kernel commandline. | |
1053 | */ | |
1054 | if (slub_debug && (!slub_debug_slabs || | |
1055 | !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)))) | |
1056 | flags |= slub_debug; | |
1057 | ||
1058 | return flags; | |
1059 | } | |
1060 | #else | |
1061 | static inline void setup_object_debug(struct kmem_cache *s, | |
1062 | struct page *page, void *object) {} | |
1063 | ||
1064 | static inline int alloc_debug_processing(struct kmem_cache *s, | |
1065 | struct page *page, void *object, unsigned long addr) { return 0; } | |
1066 | ||
1067 | static inline int free_debug_processing(struct kmem_cache *s, | |
1068 | struct page *page, void *object, unsigned long addr) { return 0; } | |
1069 | ||
1070 | static inline int slab_pad_check(struct kmem_cache *s, struct page *page) | |
1071 | { return 1; } | |
1072 | static inline int check_object(struct kmem_cache *s, struct page *page, | |
1073 | void *object, u8 val) { return 1; } | |
1074 | static inline void add_full(struct kmem_cache_node *n, struct page *page) {} | |
1075 | static inline unsigned long kmem_cache_flags(unsigned long objsize, | |
1076 | unsigned long flags, const char *name, | |
1077 | void (*ctor)(void *)) | |
1078 | { | |
1079 | return flags; | |
1080 | } | |
1081 | #define slub_debug 0 | |
1082 | ||
1083 | #define disable_higher_order_debug 0 | |
1084 | ||
1085 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) | |
1086 | { return 0; } | |
1087 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) | |
1088 | { return 0; } | |
1089 | static inline void inc_slabs_node(struct kmem_cache *s, int node, | |
1090 | int objects) {} | |
1091 | static inline void dec_slabs_node(struct kmem_cache *s, int node, | |
1092 | int objects) {} | |
1093 | ||
1094 | static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) | |
1095 | { return 0; } | |
1096 | ||
1097 | static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, | |
1098 | void *object) {} | |
1099 | ||
1100 | static inline void slab_free_hook(struct kmem_cache *s, void *x) {} | |
1101 | ||
1102 | static inline void slab_free_hook_irq(struct kmem_cache *s, | |
1103 | void *object) {} | |
1104 | ||
1105 | #endif /* CONFIG_SLUB_DEBUG */ | |
1106 | ||
1107 | /* | |
1108 | * Slab allocation and freeing | |
1109 | */ | |
1110 | static inline struct page *alloc_slab_page(gfp_t flags, int node, | |
1111 | struct kmem_cache_order_objects oo) | |
1112 | { | |
1113 | int order = oo_order(oo); | |
1114 | ||
1115 | flags |= __GFP_NOTRACK; | |
1116 | ||
1117 | if (node == NUMA_NO_NODE) | |
1118 | return alloc_pages(flags, order); | |
1119 | else | |
1120 | return alloc_pages_exact_node(node, flags, order); | |
1121 | } | |
1122 | ||
1123 | static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) | |
1124 | { | |
1125 | struct page *page; | |
1126 | struct kmem_cache_order_objects oo = s->oo; | |
1127 | gfp_t alloc_gfp; | |
1128 | ||
1129 | flags |= s->allocflags; | |
1130 | ||
1131 | /* | |
1132 | * Let the initial higher-order allocation fail under memory pressure | |
1133 | * so we fall-back to the minimum order allocation. | |
1134 | */ | |
1135 | alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL; | |
1136 | ||
1137 | page = alloc_slab_page(alloc_gfp, node, oo); | |
1138 | if (unlikely(!page)) { | |
1139 | oo = s->min; | |
1140 | /* | |
1141 | * Allocation may have failed due to fragmentation. | |
1142 | * Try a lower order alloc if possible | |
1143 | */ | |
1144 | page = alloc_slab_page(flags, node, oo); | |
1145 | if (!page) | |
1146 | return NULL; | |
1147 | ||
1148 | stat(s, ORDER_FALLBACK); | |
1149 | } | |
1150 | ||
1151 | if (kmemcheck_enabled | |
1152 | && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) { | |
1153 | int pages = 1 << oo_order(oo); | |
1154 | ||
1155 | kmemcheck_alloc_shadow(page, oo_order(oo), flags, node); | |
1156 | ||
1157 | /* | |
1158 | * Objects from caches that have a constructor don't get | |
1159 | * cleared when they're allocated, so we need to do it here. | |
1160 | */ | |
1161 | if (s->ctor) | |
1162 | kmemcheck_mark_uninitialized_pages(page, pages); | |
1163 | else | |
1164 | kmemcheck_mark_unallocated_pages(page, pages); | |
1165 | } | |
1166 | ||
1167 | page->objects = oo_objects(oo); | |
1168 | mod_zone_page_state(page_zone(page), | |
1169 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? | |
1170 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, | |
1171 | 1 << oo_order(oo)); | |
1172 | ||
1173 | return page; | |
1174 | } | |
1175 | ||
1176 | static void setup_object(struct kmem_cache *s, struct page *page, | |
1177 | void *object) | |
1178 | { | |
1179 | setup_object_debug(s, page, object); | |
1180 | if (unlikely(s->ctor)) | |
1181 | s->ctor(object); | |
1182 | } | |
1183 | ||
1184 | static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) | |
1185 | { | |
1186 | struct page *page; | |
1187 | void *start; | |
1188 | void *last; | |
1189 | void *p; | |
1190 | ||
1191 | BUG_ON(flags & GFP_SLAB_BUG_MASK); | |
1192 | ||
1193 | page = allocate_slab(s, | |
1194 | flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); | |
1195 | if (!page) | |
1196 | goto out; | |
1197 | ||
1198 | inc_slabs_node(s, page_to_nid(page), page->objects); | |
1199 | page->slab = s; | |
1200 | page->flags |= 1 << PG_slab; | |
1201 | ||
1202 | start = page_address(page); | |
1203 | ||
1204 | if (unlikely(s->flags & SLAB_POISON)) | |
1205 | memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page)); | |
1206 | ||
1207 | last = start; | |
1208 | for_each_object(p, s, start, page->objects) { | |
1209 | setup_object(s, page, last); | |
1210 | set_freepointer(s, last, p); | |
1211 | last = p; | |
1212 | } | |
1213 | setup_object(s, page, last); | |
1214 | set_freepointer(s, last, NULL); | |
1215 | ||
1216 | page->freelist = start; | |
1217 | page->inuse = 0; | |
1218 | out: | |
1219 | return page; | |
1220 | } | |
1221 | ||
1222 | static void __free_slab(struct kmem_cache *s, struct page *page) | |
1223 | { | |
1224 | int order = compound_order(page); | |
1225 | int pages = 1 << order; | |
1226 | ||
1227 | if (kmem_cache_debug(s)) { | |
1228 | void *p; | |
1229 | ||
1230 | slab_pad_check(s, page); | |
1231 | for_each_object(p, s, page_address(page), | |
1232 | page->objects) | |
1233 | check_object(s, page, p, SLUB_RED_INACTIVE); | |
1234 | } | |
1235 | ||
1236 | kmemcheck_free_shadow(page, compound_order(page)); | |
1237 | ||
1238 | mod_zone_page_state(page_zone(page), | |
1239 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? | |
1240 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, | |
1241 | -pages); | |
1242 | ||
1243 | __ClearPageSlab(page); | |
1244 | reset_page_mapcount(page); | |
1245 | if (current->reclaim_state) | |
1246 | current->reclaim_state->reclaimed_slab += pages; | |
1247 | __free_pages(page, order); | |
1248 | } | |
1249 | ||
1250 | static void rcu_free_slab(struct rcu_head *h) | |
1251 | { | |
1252 | struct page *page; | |
1253 | ||
1254 | page = container_of((struct list_head *)h, struct page, lru); | |
1255 | __free_slab(page->slab, page); | |
1256 | } | |
1257 | ||
1258 | static void free_slab(struct kmem_cache *s, struct page *page) | |
1259 | { | |
1260 | if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { | |
1261 | /* | |
1262 | * RCU free overloads the RCU head over the LRU | |
1263 | */ | |
1264 | struct rcu_head *head = (void *)&page->lru; | |
1265 | ||
1266 | call_rcu(head, rcu_free_slab); | |
1267 | } else | |
1268 | __free_slab(s, page); | |
1269 | } | |
1270 | ||
1271 | static void discard_slab(struct kmem_cache *s, struct page *page) | |
1272 | { | |
1273 | dec_slabs_node(s, page_to_nid(page), page->objects); | |
1274 | free_slab(s, page); | |
1275 | } | |
1276 | ||
1277 | /* | |
1278 | * Per slab locking using the pagelock | |
1279 | */ | |
1280 | static __always_inline void slab_lock(struct page *page) | |
1281 | { | |
1282 | bit_spin_lock(PG_locked, &page->flags); | |
1283 | } | |
1284 | ||
1285 | static __always_inline void slab_unlock(struct page *page) | |
1286 | { | |
1287 | __bit_spin_unlock(PG_locked, &page->flags); | |
1288 | } | |
1289 | ||
1290 | static __always_inline int slab_trylock(struct page *page) | |
1291 | { | |
1292 | int rc = 1; | |
1293 | ||
1294 | rc = bit_spin_trylock(PG_locked, &page->flags); | |
1295 | return rc; | |
1296 | } | |
1297 | ||
1298 | /* | |
1299 | * Management of partially allocated slabs | |
1300 | */ | |
1301 | static void add_partial(struct kmem_cache_node *n, | |
1302 | struct page *page, int tail) | |
1303 | { | |
1304 | spin_lock(&n->list_lock); | |
1305 | n->nr_partial++; | |
1306 | if (tail) | |
1307 | list_add_tail(&page->lru, &n->partial); | |
1308 | else | |
1309 | list_add(&page->lru, &n->partial); | |
1310 | spin_unlock(&n->list_lock); | |
1311 | } | |
1312 | ||
1313 | static inline void __remove_partial(struct kmem_cache_node *n, | |
1314 | struct page *page) | |
1315 | { | |
1316 | list_del(&page->lru); | |
1317 | n->nr_partial--; | |
1318 | } | |
1319 | ||
1320 | static void remove_partial(struct kmem_cache *s, struct page *page) | |
1321 | { | |
1322 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); | |
1323 | ||
1324 | spin_lock(&n->list_lock); | |
1325 | __remove_partial(n, page); | |
1326 | spin_unlock(&n->list_lock); | |
1327 | } | |
1328 | ||
1329 | /* | |
1330 | * Lock slab and remove from the partial list. | |
1331 | * | |
1332 | * Must hold list_lock. | |
1333 | */ | |
1334 | static inline int lock_and_freeze_slab(struct kmem_cache_node *n, | |
1335 | struct page *page) | |
1336 | { | |
1337 | if (slab_trylock(page)) { | |
1338 | __remove_partial(n, page); | |
1339 | __SetPageSlubFrozen(page); | |
1340 | return 1; | |
1341 | } | |
1342 | return 0; | |
1343 | } | |
1344 | ||
1345 | /* | |
1346 | * Try to allocate a partial slab from a specific node. | |
1347 | */ | |
1348 | static struct page *get_partial_node(struct kmem_cache_node *n) | |
1349 | { | |
1350 | struct page *page; | |
1351 | ||
1352 | /* | |
1353 | * Racy check. If we mistakenly see no partial slabs then we | |
1354 | * just allocate an empty slab. If we mistakenly try to get a | |
1355 | * partial slab and there is none available then get_partials() | |
1356 | * will return NULL. | |
1357 | */ | |
1358 | if (!n || !n->nr_partial) | |
1359 | return NULL; | |
1360 | ||
1361 | spin_lock(&n->list_lock); | |
1362 | list_for_each_entry(page, &n->partial, lru) | |
1363 | if (lock_and_freeze_slab(n, page)) | |
1364 | goto out; | |
1365 | page = NULL; | |
1366 | out: | |
1367 | spin_unlock(&n->list_lock); | |
1368 | return page; | |
1369 | } | |
1370 | ||
1371 | /* | |
1372 | * Get a page from somewhere. Search in increasing NUMA distances. | |
1373 | */ | |
1374 | static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags) | |
1375 | { | |
1376 | #ifdef CONFIG_NUMA | |
1377 | struct zonelist *zonelist; | |
1378 | struct zoneref *z; | |
1379 | struct zone *zone; | |
1380 | enum zone_type high_zoneidx = gfp_zone(flags); | |
1381 | struct page *page; | |
1382 | ||
1383 | /* | |
1384 | * The defrag ratio allows a configuration of the tradeoffs between | |
1385 | * inter node defragmentation and node local allocations. A lower | |
1386 | * defrag_ratio increases the tendency to do local allocations | |
1387 | * instead of attempting to obtain partial slabs from other nodes. | |
1388 | * | |
1389 | * If the defrag_ratio is set to 0 then kmalloc() always | |
1390 | * returns node local objects. If the ratio is higher then kmalloc() | |
1391 | * may return off node objects because partial slabs are obtained | |
1392 | * from other nodes and filled up. | |
1393 | * | |
1394 | * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes | |
1395 | * defrag_ratio = 1000) then every (well almost) allocation will | |
1396 | * first attempt to defrag slab caches on other nodes. This means | |
1397 | * scanning over all nodes to look for partial slabs which may be | |
1398 | * expensive if we do it every time we are trying to find a slab | |
1399 | * with available objects. | |
1400 | */ | |
1401 | if (!s->remote_node_defrag_ratio || | |
1402 | get_cycles() % 1024 > s->remote_node_defrag_ratio) | |
1403 | return NULL; | |
1404 | ||
1405 | get_mems_allowed(); | |
1406 | zonelist = node_zonelist(slab_node(current->mempolicy), flags); | |
1407 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { | |
1408 | struct kmem_cache_node *n; | |
1409 | ||
1410 | n = get_node(s, zone_to_nid(zone)); | |
1411 | ||
1412 | if (n && cpuset_zone_allowed_hardwall(zone, flags) && | |
1413 | n->nr_partial > s->min_partial) { | |
1414 | page = get_partial_node(n); | |
1415 | if (page) { | |
1416 | put_mems_allowed(); | |
1417 | return page; | |
1418 | } | |
1419 | } | |
1420 | } | |
1421 | put_mems_allowed(); | |
1422 | #endif | |
1423 | return NULL; | |
1424 | } | |
1425 | ||
1426 | /* | |
1427 | * Get a partial page, lock it and return it. | |
1428 | */ | |
1429 | static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) | |
1430 | { | |
1431 | struct page *page; | |
1432 | int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node; | |
1433 | ||
1434 | page = get_partial_node(get_node(s, searchnode)); | |
1435 | if (page || node != -1) | |
1436 | return page; | |
1437 | ||
1438 | return get_any_partial(s, flags); | |
1439 | } | |
1440 | ||
1441 | /* | |
1442 | * Move a page back to the lists. | |
1443 | * | |
1444 | * Must be called with the slab lock held. | |
1445 | * | |
1446 | * On exit the slab lock will have been dropped. | |
1447 | */ | |
1448 | static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail) | |
1449 | __releases(bitlock) | |
1450 | { | |
1451 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); | |
1452 | ||
1453 | __ClearPageSlubFrozen(page); | |
1454 | if (page->inuse) { | |
1455 | ||
1456 | if (page->freelist) { | |
1457 | add_partial(n, page, tail); | |
1458 | stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD); | |
1459 | } else { | |
1460 | stat(s, DEACTIVATE_FULL); | |
1461 | if (kmem_cache_debug(s) && (s->flags & SLAB_STORE_USER)) | |
1462 | add_full(n, page); | |
1463 | } | |
1464 | slab_unlock(page); | |
1465 | } else { | |
1466 | stat(s, DEACTIVATE_EMPTY); | |
1467 | if (n->nr_partial < s->min_partial) { | |
1468 | /* | |
1469 | * Adding an empty slab to the partial slabs in order | |
1470 | * to avoid page allocator overhead. This slab needs | |
1471 | * to come after the other slabs with objects in | |
1472 | * so that the others get filled first. That way the | |
1473 | * size of the partial list stays small. | |
1474 | * | |
1475 | * kmem_cache_shrink can reclaim any empty slabs from | |
1476 | * the partial list. | |
1477 | */ | |
1478 | add_partial(n, page, 1); | |
1479 | slab_unlock(page); | |
1480 | } else { | |
1481 | slab_unlock(page); | |
1482 | stat(s, FREE_SLAB); | |
1483 | discard_slab(s, page); | |
1484 | } | |
1485 | } | |
1486 | } | |
1487 | ||
1488 | /* | |
1489 | * Remove the cpu slab | |
1490 | */ | |
1491 | static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) | |
1492 | __releases(bitlock) | |
1493 | { | |
1494 | struct page *page = c->page; | |
1495 | int tail = 1; | |
1496 | ||
1497 | if (page->freelist) | |
1498 | stat(s, DEACTIVATE_REMOTE_FREES); | |
1499 | /* | |
1500 | * Merge cpu freelist into slab freelist. Typically we get here | |
1501 | * because both freelists are empty. So this is unlikely | |
1502 | * to occur. | |
1503 | */ | |
1504 | while (unlikely(c->freelist)) { | |
1505 | void **object; | |
1506 | ||
1507 | tail = 0; /* Hot objects. Put the slab first */ | |
1508 | ||
1509 | /* Retrieve object from cpu_freelist */ | |
1510 | object = c->freelist; | |
1511 | c->freelist = get_freepointer(s, c->freelist); | |
1512 | ||
1513 | /* And put onto the regular freelist */ | |
1514 | set_freepointer(s, object, page->freelist); | |
1515 | page->freelist = object; | |
1516 | page->inuse--; | |
1517 | } | |
1518 | c->page = NULL; | |
1519 | unfreeze_slab(s, page, tail); | |
1520 | } | |
1521 | ||
1522 | static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) | |
1523 | { | |
1524 | stat(s, CPUSLAB_FLUSH); | |
1525 | slab_lock(c->page); | |
1526 | deactivate_slab(s, c); | |
1527 | } | |
1528 | ||
1529 | /* | |
1530 | * Flush cpu slab. | |
1531 | * | |
1532 | * Called from IPI handler with interrupts disabled. | |
1533 | */ | |
1534 | static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) | |
1535 | { | |
1536 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); | |
1537 | ||
1538 | if (likely(c && c->page)) | |
1539 | flush_slab(s, c); | |
1540 | } | |
1541 | ||
1542 | static void flush_cpu_slab(void *d) | |
1543 | { | |
1544 | struct kmem_cache *s = d; | |
1545 | ||
1546 | __flush_cpu_slab(s, smp_processor_id()); | |
1547 | } | |
1548 | ||
1549 | static void flush_all(struct kmem_cache *s) | |
1550 | { | |
1551 | on_each_cpu(flush_cpu_slab, s, 1); | |
1552 | } | |
1553 | ||
1554 | /* | |
1555 | * Check if the objects in a per cpu structure fit numa | |
1556 | * locality expectations. | |
1557 | */ | |
1558 | static inline int node_match(struct kmem_cache_cpu *c, int node) | |
1559 | { | |
1560 | #ifdef CONFIG_NUMA | |
1561 | if (node != NUMA_NO_NODE && c->node != node) | |
1562 | return 0; | |
1563 | #endif | |
1564 | return 1; | |
1565 | } | |
1566 | ||
1567 | static int count_free(struct page *page) | |
1568 | { | |
1569 | return page->objects - page->inuse; | |
1570 | } | |
1571 | ||
1572 | static unsigned long count_partial(struct kmem_cache_node *n, | |
1573 | int (*get_count)(struct page *)) | |
1574 | { | |
1575 | unsigned long flags; | |
1576 | unsigned long x = 0; | |
1577 | struct page *page; | |
1578 | ||
1579 | spin_lock_irqsave(&n->list_lock, flags); | |
1580 | list_for_each_entry(page, &n->partial, lru) | |
1581 | x += get_count(page); | |
1582 | spin_unlock_irqrestore(&n->list_lock, flags); | |
1583 | return x; | |
1584 | } | |
1585 | ||
1586 | static inline unsigned long node_nr_objs(struct kmem_cache_node *n) | |
1587 | { | |
1588 | #ifdef CONFIG_SLUB_DEBUG | |
1589 | return atomic_long_read(&n->total_objects); | |
1590 | #else | |
1591 | return 0; | |
1592 | #endif | |
1593 | } | |
1594 | ||
1595 | static noinline void | |
1596 | slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) | |
1597 | { | |
1598 | int node; | |
1599 | ||
1600 | printk(KERN_WARNING | |
1601 | "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n", | |
1602 | nid, gfpflags); | |
1603 | printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, " | |
1604 | "default order: %d, min order: %d\n", s->name, s->objsize, | |
1605 | s->size, oo_order(s->oo), oo_order(s->min)); | |
1606 | ||
1607 | if (oo_order(s->min) > get_order(s->objsize)) | |
1608 | printk(KERN_WARNING " %s debugging increased min order, use " | |
1609 | "slub_debug=O to disable.\n", s->name); | |
1610 | ||
1611 | for_each_online_node(node) { | |
1612 | struct kmem_cache_node *n = get_node(s, node); | |
1613 | unsigned long nr_slabs; | |
1614 | unsigned long nr_objs; | |
1615 | unsigned long nr_free; | |
1616 | ||
1617 | if (!n) | |
1618 | continue; | |
1619 | ||
1620 | nr_free = count_partial(n, count_free); | |
1621 | nr_slabs = node_nr_slabs(n); | |
1622 | nr_objs = node_nr_objs(n); | |
1623 | ||
1624 | printk(KERN_WARNING | |
1625 | " node %d: slabs: %ld, objs: %ld, free: %ld\n", | |
1626 | node, nr_slabs, nr_objs, nr_free); | |
1627 | } | |
1628 | } | |
1629 | ||
1630 | /* | |
1631 | * Slow path. The lockless freelist is empty or we need to perform | |
1632 | * debugging duties. | |
1633 | * | |
1634 | * Interrupts are disabled. | |
1635 | * | |
1636 | * Processing is still very fast if new objects have been freed to the | |
1637 | * regular freelist. In that case we simply take over the regular freelist | |
1638 | * as the lockless freelist and zap the regular freelist. | |
1639 | * | |
1640 | * If that is not working then we fall back to the partial lists. We take the | |
1641 | * first element of the freelist as the object to allocate now and move the | |
1642 | * rest of the freelist to the lockless freelist. | |
1643 | * | |
1644 | * And if we were unable to get a new slab from the partial slab lists then | |
1645 | * we need to allocate a new slab. This is the slowest path since it involves | |
1646 | * a call to the page allocator and the setup of a new slab. | |
1647 | */ | |
1648 | static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, | |
1649 | unsigned long addr, struct kmem_cache_cpu *c) | |
1650 | { | |
1651 | void **object; | |
1652 | struct page *new; | |
1653 | ||
1654 | /* We handle __GFP_ZERO in the caller */ | |
1655 | gfpflags &= ~__GFP_ZERO; | |
1656 | ||
1657 | if (!c->page) | |
1658 | goto new_slab; | |
1659 | ||
1660 | slab_lock(c->page); | |
1661 | if (unlikely(!node_match(c, node))) | |
1662 | goto another_slab; | |
1663 | ||
1664 | stat(s, ALLOC_REFILL); | |
1665 | ||
1666 | load_freelist: | |
1667 | object = c->page->freelist; | |
1668 | if (unlikely(!object)) | |
1669 | goto another_slab; | |
1670 | if (kmem_cache_debug(s)) | |
1671 | goto debug; | |
1672 | ||
1673 | c->freelist = get_freepointer(s, object); | |
1674 | c->page->inuse = c->page->objects; | |
1675 | c->page->freelist = NULL; | |
1676 | c->node = page_to_nid(c->page); | |
1677 | unlock_out: | |
1678 | slab_unlock(c->page); | |
1679 | stat(s, ALLOC_SLOWPATH); | |
1680 | return object; | |
1681 | ||
1682 | another_slab: | |
1683 | deactivate_slab(s, c); | |
1684 | ||
1685 | new_slab: | |
1686 | new = get_partial(s, gfpflags, node); | |
1687 | if (new) { | |
1688 | c->page = new; | |
1689 | stat(s, ALLOC_FROM_PARTIAL); | |
1690 | goto load_freelist; | |
1691 | } | |
1692 | ||
1693 | gfpflags &= gfp_allowed_mask; | |
1694 | if (gfpflags & __GFP_WAIT) | |
1695 | local_irq_enable(); | |
1696 | ||
1697 | new = new_slab(s, gfpflags, node); | |
1698 | ||
1699 | if (gfpflags & __GFP_WAIT) | |
1700 | local_irq_disable(); | |
1701 | ||
1702 | if (new) { | |
1703 | c = __this_cpu_ptr(s->cpu_slab); | |
1704 | stat(s, ALLOC_SLAB); | |
1705 | if (c->page) | |
1706 | flush_slab(s, c); | |
1707 | slab_lock(new); | |
1708 | __SetPageSlubFrozen(new); | |
1709 | c->page = new; | |
1710 | goto load_freelist; | |
1711 | } | |
1712 | if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit()) | |
1713 | slab_out_of_memory(s, gfpflags, node); | |
1714 | return NULL; | |
1715 | debug: | |
1716 | if (!alloc_debug_processing(s, c->page, object, addr)) | |
1717 | goto another_slab; | |
1718 | ||
1719 | c->page->inuse++; | |
1720 | c->page->freelist = get_freepointer(s, object); | |
1721 | c->node = NUMA_NO_NODE; | |
1722 | goto unlock_out; | |
1723 | } | |
1724 | ||
1725 | /* | |
1726 | * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc) | |
1727 | * have the fastpath folded into their functions. So no function call | |
1728 | * overhead for requests that can be satisfied on the fastpath. | |
1729 | * | |
1730 | * The fastpath works by first checking if the lockless freelist can be used. | |
1731 | * If not then __slab_alloc is called for slow processing. | |
1732 | * | |
1733 | * Otherwise we can simply pick the next object from the lockless free list. | |
1734 | */ | |
1735 | static __always_inline void *slab_alloc(struct kmem_cache *s, | |
1736 | gfp_t gfpflags, int node, unsigned long addr) | |
1737 | { | |
1738 | void **object; | |
1739 | struct kmem_cache_cpu *c; | |
1740 | unsigned long flags; | |
1741 | ||
1742 | if (slab_pre_alloc_hook(s, gfpflags)) | |
1743 | return NULL; | |
1744 | ||
1745 | local_irq_save(flags); | |
1746 | c = __this_cpu_ptr(s->cpu_slab); | |
1747 | object = c->freelist; | |
1748 | if (unlikely(!object || !node_match(c, node))) | |
1749 | ||
1750 | object = __slab_alloc(s, gfpflags, node, addr, c); | |
1751 | ||
1752 | else { | |
1753 | c->freelist = get_freepointer(s, object); | |
1754 | stat(s, ALLOC_FASTPATH); | |
1755 | } | |
1756 | local_irq_restore(flags); | |
1757 | ||
1758 | if (unlikely(gfpflags & __GFP_ZERO) && object) | |
1759 | memset(object, 0, s->objsize); | |
1760 | ||
1761 | slab_post_alloc_hook(s, gfpflags, object); | |
1762 | ||
1763 | return object; | |
1764 | } | |
1765 | ||
1766 | void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) | |
1767 | { | |
1768 | void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_); | |
1769 | ||
1770 | trace_kmem_cache_alloc(_RET_IP_, ret, s->objsize, s->size, gfpflags); | |
1771 | ||
1772 | return ret; | |
1773 | } | |
1774 | EXPORT_SYMBOL(kmem_cache_alloc); | |
1775 | ||
1776 | #ifdef CONFIG_TRACING | |
1777 | void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags) | |
1778 | { | |
1779 | return slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_); | |
1780 | } | |
1781 | EXPORT_SYMBOL(kmem_cache_alloc_notrace); | |
1782 | #endif | |
1783 | ||
1784 | #ifdef CONFIG_NUMA | |
1785 | void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node) | |
1786 | { | |
1787 | void *ret = slab_alloc(s, gfpflags, node, _RET_IP_); | |
1788 | ||
1789 | trace_kmem_cache_alloc_node(_RET_IP_, ret, | |
1790 | s->objsize, s->size, gfpflags, node); | |
1791 | ||
1792 | return ret; | |
1793 | } | |
1794 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
1795 | ||
1796 | #ifdef CONFIG_TRACING | |
1797 | void *kmem_cache_alloc_node_notrace(struct kmem_cache *s, | |
1798 | gfp_t gfpflags, | |
1799 | int node) | |
1800 | { | |
1801 | return slab_alloc(s, gfpflags, node, _RET_IP_); | |
1802 | } | |
1803 | EXPORT_SYMBOL(kmem_cache_alloc_node_notrace); | |
1804 | #endif | |
1805 | #endif | |
1806 | ||
1807 | /* | |
1808 | * Slow patch handling. This may still be called frequently since objects | |
1809 | * have a longer lifetime than the cpu slabs in most processing loads. | |
1810 | * | |
1811 | * So we still attempt to reduce cache line usage. Just take the slab | |
1812 | * lock and free the item. If there is no additional partial page | |
1813 | * handling required then we can return immediately. | |
1814 | */ | |
1815 | static void __slab_free(struct kmem_cache *s, struct page *page, | |
1816 | void *x, unsigned long addr) | |
1817 | { | |
1818 | void *prior; | |
1819 | void **object = (void *)x; | |
1820 | ||
1821 | stat(s, FREE_SLOWPATH); | |
1822 | slab_lock(page); | |
1823 | ||
1824 | if (kmem_cache_debug(s)) | |
1825 | goto debug; | |
1826 | ||
1827 | checks_ok: | |
1828 | prior = page->freelist; | |
1829 | set_freepointer(s, object, prior); | |
1830 | page->freelist = object; | |
1831 | page->inuse--; | |
1832 | ||
1833 | if (unlikely(PageSlubFrozen(page))) { | |
1834 | stat(s, FREE_FROZEN); | |
1835 | goto out_unlock; | |
1836 | } | |
1837 | ||
1838 | if (unlikely(!page->inuse)) | |
1839 | goto slab_empty; | |
1840 | ||
1841 | /* | |
1842 | * Objects left in the slab. If it was not on the partial list before | |
1843 | * then add it. | |
1844 | */ | |
1845 | if (unlikely(!prior)) { | |
1846 | add_partial(get_node(s, page_to_nid(page)), page, 1); | |
1847 | stat(s, FREE_ADD_PARTIAL); | |
1848 | } | |
1849 | ||
1850 | out_unlock: | |
1851 | slab_unlock(page); | |
1852 | return; | |
1853 | ||
1854 | slab_empty: | |
1855 | if (prior) { | |
1856 | /* | |
1857 | * Slab still on the partial list. | |
1858 | */ | |
1859 | remove_partial(s, page); | |
1860 | stat(s, FREE_REMOVE_PARTIAL); | |
1861 | } | |
1862 | slab_unlock(page); | |
1863 | stat(s, FREE_SLAB); | |
1864 | discard_slab(s, page); | |
1865 | return; | |
1866 | ||
1867 | debug: | |
1868 | if (!free_debug_processing(s, page, x, addr)) | |
1869 | goto out_unlock; | |
1870 | goto checks_ok; | |
1871 | } | |
1872 | ||
1873 | /* | |
1874 | * Fastpath with forced inlining to produce a kfree and kmem_cache_free that | |
1875 | * can perform fastpath freeing without additional function calls. | |
1876 | * | |
1877 | * The fastpath is only possible if we are freeing to the current cpu slab | |
1878 | * of this processor. This typically the case if we have just allocated | |
1879 | * the item before. | |
1880 | * | |
1881 | * If fastpath is not possible then fall back to __slab_free where we deal | |
1882 | * with all sorts of special processing. | |
1883 | */ | |
1884 | static __always_inline void slab_free(struct kmem_cache *s, | |
1885 | struct page *page, void *x, unsigned long addr) | |
1886 | { | |
1887 | void **object = (void *)x; | |
1888 | struct kmem_cache_cpu *c; | |
1889 | unsigned long flags; | |
1890 | ||
1891 | slab_free_hook(s, x); | |
1892 | ||
1893 | local_irq_save(flags); | |
1894 | c = __this_cpu_ptr(s->cpu_slab); | |
1895 | ||
1896 | slab_free_hook_irq(s, x); | |
1897 | ||
1898 | if (likely(page == c->page && c->node != NUMA_NO_NODE)) { | |
1899 | set_freepointer(s, object, c->freelist); | |
1900 | c->freelist = object; | |
1901 | stat(s, FREE_FASTPATH); | |
1902 | } else | |
1903 | __slab_free(s, page, x, addr); | |
1904 | ||
1905 | local_irq_restore(flags); | |
1906 | } | |
1907 | ||
1908 | void kmem_cache_free(struct kmem_cache *s, void *x) | |
1909 | { | |
1910 | struct page *page; | |
1911 | ||
1912 | page = virt_to_head_page(x); | |
1913 | ||
1914 | slab_free(s, page, x, _RET_IP_); | |
1915 | ||
1916 | trace_kmem_cache_free(_RET_IP_, x); | |
1917 | } | |
1918 | EXPORT_SYMBOL(kmem_cache_free); | |
1919 | ||
1920 | /* Figure out on which slab page the object resides */ | |
1921 | static struct page *get_object_page(const void *x) | |
1922 | { | |
1923 | struct page *page = virt_to_head_page(x); | |
1924 | ||
1925 | if (!PageSlab(page)) | |
1926 | return NULL; | |
1927 | ||
1928 | return page; | |
1929 | } | |
1930 | ||
1931 | /* | |
1932 | * Object placement in a slab is made very easy because we always start at | |
1933 | * offset 0. If we tune the size of the object to the alignment then we can | |
1934 | * get the required alignment by putting one properly sized object after | |
1935 | * another. | |
1936 | * | |
1937 | * Notice that the allocation order determines the sizes of the per cpu | |
1938 | * caches. Each processor has always one slab available for allocations. | |
1939 | * Increasing the allocation order reduces the number of times that slabs | |
1940 | * must be moved on and off the partial lists and is therefore a factor in | |
1941 | * locking overhead. | |
1942 | */ | |
1943 | ||
1944 | /* | |
1945 | * Mininum / Maximum order of slab pages. This influences locking overhead | |
1946 | * and slab fragmentation. A higher order reduces the number of partial slabs | |
1947 | * and increases the number of allocations possible without having to | |
1948 | * take the list_lock. | |
1949 | */ | |
1950 | static int slub_min_order; | |
1951 | static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER; | |
1952 | static int slub_min_objects; | |
1953 | ||
1954 | /* | |
1955 | * Merge control. If this is set then no merging of slab caches will occur. | |
1956 | * (Could be removed. This was introduced to pacify the merge skeptics.) | |
1957 | */ | |
1958 | static int slub_nomerge; | |
1959 | ||
1960 | /* | |
1961 | * Calculate the order of allocation given an slab object size. | |
1962 | * | |
1963 | * The order of allocation has significant impact on performance and other | |
1964 | * system components. Generally order 0 allocations should be preferred since | |
1965 | * order 0 does not cause fragmentation in the page allocator. Larger objects | |
1966 | * be problematic to put into order 0 slabs because there may be too much | |
1967 | * unused space left. We go to a higher order if more than 1/16th of the slab | |
1968 | * would be wasted. | |
1969 | * | |
1970 | * In order to reach satisfactory performance we must ensure that a minimum | |
1971 | * number of objects is in one slab. Otherwise we may generate too much | |
1972 | * activity on the partial lists which requires taking the list_lock. This is | |
1973 | * less a concern for large slabs though which are rarely used. | |
1974 | * | |
1975 | * slub_max_order specifies the order where we begin to stop considering the | |
1976 | * number of objects in a slab as critical. If we reach slub_max_order then | |
1977 | * we try to keep the page order as low as possible. So we accept more waste | |
1978 | * of space in favor of a small page order. | |
1979 | * | |
1980 | * Higher order allocations also allow the placement of more objects in a | |
1981 | * slab and thereby reduce object handling overhead. If the user has | |
1982 | * requested a higher mininum order then we start with that one instead of | |
1983 | * the smallest order which will fit the object. | |
1984 | */ | |
1985 | static inline int slab_order(int size, int min_objects, | |
1986 | int max_order, int fract_leftover) | |
1987 | { | |
1988 | int order; | |
1989 | int rem; | |
1990 | int min_order = slub_min_order; | |
1991 | ||
1992 | if ((PAGE_SIZE << min_order) / size > MAX_OBJS_PER_PAGE) | |
1993 | return get_order(size * MAX_OBJS_PER_PAGE) - 1; | |
1994 | ||
1995 | for (order = max(min_order, | |
1996 | fls(min_objects * size - 1) - PAGE_SHIFT); | |
1997 | order <= max_order; order++) { | |
1998 | ||
1999 | unsigned long slab_size = PAGE_SIZE << order; | |
2000 | ||
2001 | if (slab_size < min_objects * size) | |
2002 | continue; | |
2003 | ||
2004 | rem = slab_size % size; | |
2005 | ||
2006 | if (rem <= slab_size / fract_leftover) | |
2007 | break; | |
2008 | ||
2009 | } | |
2010 | ||
2011 | return order; | |
2012 | } | |
2013 | ||
2014 | static inline int calculate_order(int size) | |
2015 | { | |
2016 | int order; | |
2017 | int min_objects; | |
2018 | int fraction; | |
2019 | int max_objects; | |
2020 | ||
2021 | /* | |
2022 | * Attempt to find best configuration for a slab. This | |
2023 | * works by first attempting to generate a layout with | |
2024 | * the best configuration and backing off gradually. | |
2025 | * | |
2026 | * First we reduce the acceptable waste in a slab. Then | |
2027 | * we reduce the minimum objects required in a slab. | |
2028 | */ | |
2029 | min_objects = slub_min_objects; | |
2030 | if (!min_objects) | |
2031 | min_objects = 4 * (fls(nr_cpu_ids) + 1); | |
2032 | max_objects = (PAGE_SIZE << slub_max_order)/size; | |
2033 | min_objects = min(min_objects, max_objects); | |
2034 | ||
2035 | while (min_objects > 1) { | |
2036 | fraction = 16; | |
2037 | while (fraction >= 4) { | |
2038 | order = slab_order(size, min_objects, | |
2039 | slub_max_order, fraction); | |
2040 | if (order <= slub_max_order) | |
2041 | return order; | |
2042 | fraction /= 2; | |
2043 | } | |
2044 | min_objects--; | |
2045 | } | |
2046 | ||
2047 | /* | |
2048 | * We were unable to place multiple objects in a slab. Now | |
2049 | * lets see if we can place a single object there. | |
2050 | */ | |
2051 | order = slab_order(size, 1, slub_max_order, 1); | |
2052 | if (order <= slub_max_order) | |
2053 | return order; | |
2054 | ||
2055 | /* | |
2056 | * Doh this slab cannot be placed using slub_max_order. | |
2057 | */ | |
2058 | order = slab_order(size, 1, MAX_ORDER, 1); | |
2059 | if (order < MAX_ORDER) | |
2060 | return order; | |
2061 | return -ENOSYS; | |
2062 | } | |
2063 | ||
2064 | /* | |
2065 | * Figure out what the alignment of the objects will be. | |
2066 | */ | |
2067 | static unsigned long calculate_alignment(unsigned long flags, | |
2068 | unsigned long align, unsigned long size) | |
2069 | { | |
2070 | /* | |
2071 | * If the user wants hardware cache aligned objects then follow that | |
2072 | * suggestion if the object is sufficiently large. | |
2073 | * | |
2074 | * The hardware cache alignment cannot override the specified | |
2075 | * alignment though. If that is greater then use it. | |
2076 | */ | |
2077 | if (flags & SLAB_HWCACHE_ALIGN) { | |
2078 | unsigned long ralign = cache_line_size(); | |
2079 | while (size <= ralign / 2) | |
2080 | ralign /= 2; | |
2081 | align = max(align, ralign); | |
2082 | } | |
2083 | ||
2084 | if (align < ARCH_SLAB_MINALIGN) | |
2085 | align = ARCH_SLAB_MINALIGN; | |
2086 | ||
2087 | return ALIGN(align, sizeof(void *)); | |
2088 | } | |
2089 | ||
2090 | static void | |
2091 | init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s) | |
2092 | { | |
2093 | n->nr_partial = 0; | |
2094 | spin_lock_init(&n->list_lock); | |
2095 | INIT_LIST_HEAD(&n->partial); | |
2096 | #ifdef CONFIG_SLUB_DEBUG | |
2097 | atomic_long_set(&n->nr_slabs, 0); | |
2098 | atomic_long_set(&n->total_objects, 0); | |
2099 | INIT_LIST_HEAD(&n->full); | |
2100 | #endif | |
2101 | } | |
2102 | ||
2103 | static inline int alloc_kmem_cache_cpus(struct kmem_cache *s) | |
2104 | { | |
2105 | BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE < | |
2106 | SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu)); | |
2107 | ||
2108 | s->cpu_slab = alloc_percpu(struct kmem_cache_cpu); | |
2109 | ||
2110 | return s->cpu_slab != NULL; | |
2111 | } | |
2112 | ||
2113 | static struct kmem_cache *kmem_cache_node; | |
2114 | ||
2115 | /* | |
2116 | * No kmalloc_node yet so do it by hand. We know that this is the first | |
2117 | * slab on the node for this slabcache. There are no concurrent accesses | |
2118 | * possible. | |
2119 | * | |
2120 | * Note that this function only works on the kmalloc_node_cache | |
2121 | * when allocating for the kmalloc_node_cache. This is used for bootstrapping | |
2122 | * memory on a fresh node that has no slab structures yet. | |
2123 | */ | |
2124 | static void early_kmem_cache_node_alloc(int node) | |
2125 | { | |
2126 | struct page *page; | |
2127 | struct kmem_cache_node *n; | |
2128 | unsigned long flags; | |
2129 | ||
2130 | BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node)); | |
2131 | ||
2132 | page = new_slab(kmem_cache_node, GFP_NOWAIT, node); | |
2133 | ||
2134 | BUG_ON(!page); | |
2135 | if (page_to_nid(page) != node) { | |
2136 | printk(KERN_ERR "SLUB: Unable to allocate memory from " | |
2137 | "node %d\n", node); | |
2138 | printk(KERN_ERR "SLUB: Allocating a useless per node structure " | |
2139 | "in order to be able to continue\n"); | |
2140 | } | |
2141 | ||
2142 | n = page->freelist; | |
2143 | BUG_ON(!n); | |
2144 | page->freelist = get_freepointer(kmem_cache_node, n); | |
2145 | page->inuse++; | |
2146 | kmem_cache_node->node[node] = n; | |
2147 | #ifdef CONFIG_SLUB_DEBUG | |
2148 | init_object(kmem_cache_node, n, SLUB_RED_ACTIVE); | |
2149 | init_tracking(kmem_cache_node, n); | |
2150 | #endif | |
2151 | init_kmem_cache_node(n, kmem_cache_node); | |
2152 | inc_slabs_node(kmem_cache_node, node, page->objects); | |
2153 | ||
2154 | /* | |
2155 | * lockdep requires consistent irq usage for each lock | |
2156 | * so even though there cannot be a race this early in | |
2157 | * the boot sequence, we still disable irqs. | |
2158 | */ | |
2159 | local_irq_save(flags); | |
2160 | add_partial(n, page, 0); | |
2161 | local_irq_restore(flags); | |
2162 | } | |
2163 | ||
2164 | static void free_kmem_cache_nodes(struct kmem_cache *s) | |
2165 | { | |
2166 | int node; | |
2167 | ||
2168 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
2169 | struct kmem_cache_node *n = s->node[node]; | |
2170 | ||
2171 | if (n) | |
2172 | kmem_cache_free(kmem_cache_node, n); | |
2173 | ||
2174 | s->node[node] = NULL; | |
2175 | } | |
2176 | } | |
2177 | ||
2178 | static int init_kmem_cache_nodes(struct kmem_cache *s) | |
2179 | { | |
2180 | int node; | |
2181 | ||
2182 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
2183 | struct kmem_cache_node *n; | |
2184 | ||
2185 | if (slab_state == DOWN) { | |
2186 | early_kmem_cache_node_alloc(node); | |
2187 | continue; | |
2188 | } | |
2189 | n = kmem_cache_alloc_node(kmem_cache_node, | |
2190 | GFP_KERNEL, node); | |
2191 | ||
2192 | if (!n) { | |
2193 | free_kmem_cache_nodes(s); | |
2194 | return 0; | |
2195 | } | |
2196 | ||
2197 | s->node[node] = n; | |
2198 | init_kmem_cache_node(n, s); | |
2199 | } | |
2200 | return 1; | |
2201 | } | |
2202 | ||
2203 | static void set_min_partial(struct kmem_cache *s, unsigned long min) | |
2204 | { | |
2205 | if (min < MIN_PARTIAL) | |
2206 | min = MIN_PARTIAL; | |
2207 | else if (min > MAX_PARTIAL) | |
2208 | min = MAX_PARTIAL; | |
2209 | s->min_partial = min; | |
2210 | } | |
2211 | ||
2212 | /* | |
2213 | * calculate_sizes() determines the order and the distribution of data within | |
2214 | * a slab object. | |
2215 | */ | |
2216 | static int calculate_sizes(struct kmem_cache *s, int forced_order) | |
2217 | { | |
2218 | unsigned long flags = s->flags; | |
2219 | unsigned long size = s->objsize; | |
2220 | unsigned long align = s->align; | |
2221 | int order; | |
2222 | ||
2223 | /* | |
2224 | * Round up object size to the next word boundary. We can only | |
2225 | * place the free pointer at word boundaries and this determines | |
2226 | * the possible location of the free pointer. | |
2227 | */ | |
2228 | size = ALIGN(size, sizeof(void *)); | |
2229 | ||
2230 | #ifdef CONFIG_SLUB_DEBUG | |
2231 | /* | |
2232 | * Determine if we can poison the object itself. If the user of | |
2233 | * the slab may touch the object after free or before allocation | |
2234 | * then we should never poison the object itself. | |
2235 | */ | |
2236 | if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) && | |
2237 | !s->ctor) | |
2238 | s->flags |= __OBJECT_POISON; | |
2239 | else | |
2240 | s->flags &= ~__OBJECT_POISON; | |
2241 | ||
2242 | ||
2243 | /* | |
2244 | * If we are Redzoning then check if there is some space between the | |
2245 | * end of the object and the free pointer. If not then add an | |
2246 | * additional word to have some bytes to store Redzone information. | |
2247 | */ | |
2248 | if ((flags & SLAB_RED_ZONE) && size == s->objsize) | |
2249 | size += sizeof(void *); | |
2250 | #endif | |
2251 | ||
2252 | /* | |
2253 | * With that we have determined the number of bytes in actual use | |
2254 | * by the object. This is the potential offset to the free pointer. | |
2255 | */ | |
2256 | s->inuse = size; | |
2257 | ||
2258 | if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || | |
2259 | s->ctor)) { | |
2260 | /* | |
2261 | * Relocate free pointer after the object if it is not | |
2262 | * permitted to overwrite the first word of the object on | |
2263 | * kmem_cache_free. | |
2264 | * | |
2265 | * This is the case if we do RCU, have a constructor or | |
2266 | * destructor or are poisoning the objects. | |
2267 | */ | |
2268 | s->offset = size; | |
2269 | size += sizeof(void *); | |
2270 | } | |
2271 | ||
2272 | #ifdef CONFIG_SLUB_DEBUG | |
2273 | if (flags & SLAB_STORE_USER) | |
2274 | /* | |
2275 | * Need to store information about allocs and frees after | |
2276 | * the object. | |
2277 | */ | |
2278 | size += 2 * sizeof(struct track); | |
2279 | ||
2280 | if (flags & SLAB_RED_ZONE) | |
2281 | /* | |
2282 | * Add some empty padding so that we can catch | |
2283 | * overwrites from earlier objects rather than let | |
2284 | * tracking information or the free pointer be | |
2285 | * corrupted if a user writes before the start | |
2286 | * of the object. | |
2287 | */ | |
2288 | size += sizeof(void *); | |
2289 | #endif | |
2290 | ||
2291 | /* | |
2292 | * Determine the alignment based on various parameters that the | |
2293 | * user specified and the dynamic determination of cache line size | |
2294 | * on bootup. | |
2295 | */ | |
2296 | align = calculate_alignment(flags, align, s->objsize); | |
2297 | s->align = align; | |
2298 | ||
2299 | /* | |
2300 | * SLUB stores one object immediately after another beginning from | |
2301 | * offset 0. In order to align the objects we have to simply size | |
2302 | * each object to conform to the alignment. | |
2303 | */ | |
2304 | size = ALIGN(size, align); | |
2305 | s->size = size; | |
2306 | if (forced_order >= 0) | |
2307 | order = forced_order; | |
2308 | else | |
2309 | order = calculate_order(size); | |
2310 | ||
2311 | if (order < 0) | |
2312 | return 0; | |
2313 | ||
2314 | s->allocflags = 0; | |
2315 | if (order) | |
2316 | s->allocflags |= __GFP_COMP; | |
2317 | ||
2318 | if (s->flags & SLAB_CACHE_DMA) | |
2319 | s->allocflags |= SLUB_DMA; | |
2320 | ||
2321 | if (s->flags & SLAB_RECLAIM_ACCOUNT) | |
2322 | s->allocflags |= __GFP_RECLAIMABLE; | |
2323 | ||
2324 | /* | |
2325 | * Determine the number of objects per slab | |
2326 | */ | |
2327 | s->oo = oo_make(order, size); | |
2328 | s->min = oo_make(get_order(size), size); | |
2329 | if (oo_objects(s->oo) > oo_objects(s->max)) | |
2330 | s->max = s->oo; | |
2331 | ||
2332 | return !!oo_objects(s->oo); | |
2333 | ||
2334 | } | |
2335 | ||
2336 | static int kmem_cache_open(struct kmem_cache *s, | |
2337 | const char *name, size_t size, | |
2338 | size_t align, unsigned long flags, | |
2339 | void (*ctor)(void *)) | |
2340 | { | |
2341 | memset(s, 0, kmem_size); | |
2342 | s->name = name; | |
2343 | s->ctor = ctor; | |
2344 | s->objsize = size; | |
2345 | s->align = align; | |
2346 | s->flags = kmem_cache_flags(size, flags, name, ctor); | |
2347 | ||
2348 | if (!calculate_sizes(s, -1)) | |
2349 | goto error; | |
2350 | if (disable_higher_order_debug) { | |
2351 | /* | |
2352 | * Disable debugging flags that store metadata if the min slab | |
2353 | * order increased. | |
2354 | */ | |
2355 | if (get_order(s->size) > get_order(s->objsize)) { | |
2356 | s->flags &= ~DEBUG_METADATA_FLAGS; | |
2357 | s->offset = 0; | |
2358 | if (!calculate_sizes(s, -1)) | |
2359 | goto error; | |
2360 | } | |
2361 | } | |
2362 | ||
2363 | /* | |
2364 | * The larger the object size is, the more pages we want on the partial | |
2365 | * list to avoid pounding the page allocator excessively. | |
2366 | */ | |
2367 | set_min_partial(s, ilog2(s->size)); | |
2368 | s->refcount = 1; | |
2369 | #ifdef CONFIG_NUMA | |
2370 | s->remote_node_defrag_ratio = 1000; | |
2371 | #endif | |
2372 | if (!init_kmem_cache_nodes(s)) | |
2373 | goto error; | |
2374 | ||
2375 | if (alloc_kmem_cache_cpus(s)) | |
2376 | return 1; | |
2377 | ||
2378 | free_kmem_cache_nodes(s); | |
2379 | error: | |
2380 | if (flags & SLAB_PANIC) | |
2381 | panic("Cannot create slab %s size=%lu realsize=%u " | |
2382 | "order=%u offset=%u flags=%lx\n", | |
2383 | s->name, (unsigned long)size, s->size, oo_order(s->oo), | |
2384 | s->offset, flags); | |
2385 | return 0; | |
2386 | } | |
2387 | ||
2388 | /* | |
2389 | * Check if a given pointer is valid | |
2390 | */ | |
2391 | int kmem_ptr_validate(struct kmem_cache *s, const void *object) | |
2392 | { | |
2393 | struct page *page; | |
2394 | ||
2395 | if (!kern_ptr_validate(object, s->size)) | |
2396 | return 0; | |
2397 | ||
2398 | page = get_object_page(object); | |
2399 | ||
2400 | if (!page || s != page->slab) | |
2401 | /* No slab or wrong slab */ | |
2402 | return 0; | |
2403 | ||
2404 | if (!check_valid_pointer(s, page, object)) | |
2405 | return 0; | |
2406 | ||
2407 | /* | |
2408 | * We could also check if the object is on the slabs freelist. | |
2409 | * But this would be too expensive and it seems that the main | |
2410 | * purpose of kmem_ptr_valid() is to check if the object belongs | |
2411 | * to a certain slab. | |
2412 | */ | |
2413 | return 1; | |
2414 | } | |
2415 | EXPORT_SYMBOL(kmem_ptr_validate); | |
2416 | ||
2417 | /* | |
2418 | * Determine the size of a slab object | |
2419 | */ | |
2420 | unsigned int kmem_cache_size(struct kmem_cache *s) | |
2421 | { | |
2422 | return s->objsize; | |
2423 | } | |
2424 | EXPORT_SYMBOL(kmem_cache_size); | |
2425 | ||
2426 | const char *kmem_cache_name(struct kmem_cache *s) | |
2427 | { | |
2428 | return s->name; | |
2429 | } | |
2430 | EXPORT_SYMBOL(kmem_cache_name); | |
2431 | ||
2432 | static void list_slab_objects(struct kmem_cache *s, struct page *page, | |
2433 | const char *text) | |
2434 | { | |
2435 | #ifdef CONFIG_SLUB_DEBUG | |
2436 | void *addr = page_address(page); | |
2437 | void *p; | |
2438 | unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) * | |
2439 | sizeof(long), GFP_ATOMIC); | |
2440 | if (!map) | |
2441 | return; | |
2442 | slab_err(s, page, "%s", text); | |
2443 | slab_lock(page); | |
2444 | for_each_free_object(p, s, page->freelist) | |
2445 | set_bit(slab_index(p, s, addr), map); | |
2446 | ||
2447 | for_each_object(p, s, addr, page->objects) { | |
2448 | ||
2449 | if (!test_bit(slab_index(p, s, addr), map)) { | |
2450 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n", | |
2451 | p, p - addr); | |
2452 | print_tracking(s, p); | |
2453 | } | |
2454 | } | |
2455 | slab_unlock(page); | |
2456 | kfree(map); | |
2457 | #endif | |
2458 | } | |
2459 | ||
2460 | /* | |
2461 | * Attempt to free all partial slabs on a node. | |
2462 | */ | |
2463 | static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) | |
2464 | { | |
2465 | unsigned long flags; | |
2466 | struct page *page, *h; | |
2467 | ||
2468 | spin_lock_irqsave(&n->list_lock, flags); | |
2469 | list_for_each_entry_safe(page, h, &n->partial, lru) { | |
2470 | if (!page->inuse) { | |
2471 | __remove_partial(n, page); | |
2472 | discard_slab(s, page); | |
2473 | } else { | |
2474 | list_slab_objects(s, page, | |
2475 | "Objects remaining on kmem_cache_close()"); | |
2476 | } | |
2477 | } | |
2478 | spin_unlock_irqrestore(&n->list_lock, flags); | |
2479 | } | |
2480 | ||
2481 | /* | |
2482 | * Release all resources used by a slab cache. | |
2483 | */ | |
2484 | static inline int kmem_cache_close(struct kmem_cache *s) | |
2485 | { | |
2486 | int node; | |
2487 | ||
2488 | flush_all(s); | |
2489 | free_percpu(s->cpu_slab); | |
2490 | /* Attempt to free all objects */ | |
2491 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
2492 | struct kmem_cache_node *n = get_node(s, node); | |
2493 | ||
2494 | free_partial(s, n); | |
2495 | if (n->nr_partial || slabs_node(s, node)) | |
2496 | return 1; | |
2497 | } | |
2498 | free_kmem_cache_nodes(s); | |
2499 | return 0; | |
2500 | } | |
2501 | ||
2502 | /* | |
2503 | * Close a cache and release the kmem_cache structure | |
2504 | * (must be used for caches created using kmem_cache_create) | |
2505 | */ | |
2506 | void kmem_cache_destroy(struct kmem_cache *s) | |
2507 | { | |
2508 | down_write(&slub_lock); | |
2509 | s->refcount--; | |
2510 | if (!s->refcount) { | |
2511 | list_del(&s->list); | |
2512 | if (kmem_cache_close(s)) { | |
2513 | printk(KERN_ERR "SLUB %s: %s called for cache that " | |
2514 | "still has objects.\n", s->name, __func__); | |
2515 | dump_stack(); | |
2516 | } | |
2517 | if (s->flags & SLAB_DESTROY_BY_RCU) | |
2518 | rcu_barrier(); | |
2519 | sysfs_slab_remove(s); | |
2520 | } | |
2521 | up_write(&slub_lock); | |
2522 | } | |
2523 | EXPORT_SYMBOL(kmem_cache_destroy); | |
2524 | ||
2525 | /******************************************************************** | |
2526 | * Kmalloc subsystem | |
2527 | *******************************************************************/ | |
2528 | ||
2529 | struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT]; | |
2530 | EXPORT_SYMBOL(kmalloc_caches); | |
2531 | ||
2532 | static struct kmem_cache *kmem_cache; | |
2533 | ||
2534 | #ifdef CONFIG_ZONE_DMA | |
2535 | static struct kmem_cache *kmalloc_dma_caches[SLUB_PAGE_SHIFT]; | |
2536 | #endif | |
2537 | ||
2538 | static int __init setup_slub_min_order(char *str) | |
2539 | { | |
2540 | get_option(&str, &slub_min_order); | |
2541 | ||
2542 | return 1; | |
2543 | } | |
2544 | ||
2545 | __setup("slub_min_order=", setup_slub_min_order); | |
2546 | ||
2547 | static int __init setup_slub_max_order(char *str) | |
2548 | { | |
2549 | get_option(&str, &slub_max_order); | |
2550 | slub_max_order = min(slub_max_order, MAX_ORDER - 1); | |
2551 | ||
2552 | return 1; | |
2553 | } | |
2554 | ||
2555 | __setup("slub_max_order=", setup_slub_max_order); | |
2556 | ||
2557 | static int __init setup_slub_min_objects(char *str) | |
2558 | { | |
2559 | get_option(&str, &slub_min_objects); | |
2560 | ||
2561 | return 1; | |
2562 | } | |
2563 | ||
2564 | __setup("slub_min_objects=", setup_slub_min_objects); | |
2565 | ||
2566 | static int __init setup_slub_nomerge(char *str) | |
2567 | { | |
2568 | slub_nomerge = 1; | |
2569 | return 1; | |
2570 | } | |
2571 | ||
2572 | __setup("slub_nomerge", setup_slub_nomerge); | |
2573 | ||
2574 | static struct kmem_cache *__init create_kmalloc_cache(const char *name, | |
2575 | int size, unsigned int flags) | |
2576 | { | |
2577 | struct kmem_cache *s; | |
2578 | ||
2579 | s = kmem_cache_alloc(kmem_cache, GFP_NOWAIT); | |
2580 | ||
2581 | /* | |
2582 | * This function is called with IRQs disabled during early-boot on | |
2583 | * single CPU so there's no need to take slub_lock here. | |
2584 | */ | |
2585 | if (!kmem_cache_open(s, name, size, ARCH_KMALLOC_MINALIGN, | |
2586 | flags, NULL)) | |
2587 | goto panic; | |
2588 | ||
2589 | list_add(&s->list, &slab_caches); | |
2590 | return s; | |
2591 | ||
2592 | panic: | |
2593 | panic("Creation of kmalloc slab %s size=%d failed.\n", name, size); | |
2594 | return NULL; | |
2595 | } | |
2596 | ||
2597 | /* | |
2598 | * Conversion table for small slabs sizes / 8 to the index in the | |
2599 | * kmalloc array. This is necessary for slabs < 192 since we have non power | |
2600 | * of two cache sizes there. The size of larger slabs can be determined using | |
2601 | * fls. | |
2602 | */ | |
2603 | static s8 size_index[24] = { | |
2604 | 3, /* 8 */ | |
2605 | 4, /* 16 */ | |
2606 | 5, /* 24 */ | |
2607 | 5, /* 32 */ | |
2608 | 6, /* 40 */ | |
2609 | 6, /* 48 */ | |
2610 | 6, /* 56 */ | |
2611 | 6, /* 64 */ | |
2612 | 1, /* 72 */ | |
2613 | 1, /* 80 */ | |
2614 | 1, /* 88 */ | |
2615 | 1, /* 96 */ | |
2616 | 7, /* 104 */ | |
2617 | 7, /* 112 */ | |
2618 | 7, /* 120 */ | |
2619 | 7, /* 128 */ | |
2620 | 2, /* 136 */ | |
2621 | 2, /* 144 */ | |
2622 | 2, /* 152 */ | |
2623 | 2, /* 160 */ | |
2624 | 2, /* 168 */ | |
2625 | 2, /* 176 */ | |
2626 | 2, /* 184 */ | |
2627 | 2 /* 192 */ | |
2628 | }; | |
2629 | ||
2630 | static inline int size_index_elem(size_t bytes) | |
2631 | { | |
2632 | return (bytes - 1) / 8; | |
2633 | } | |
2634 | ||
2635 | static struct kmem_cache *get_slab(size_t size, gfp_t flags) | |
2636 | { | |
2637 | int index; | |
2638 | ||
2639 | if (size <= 192) { | |
2640 | if (!size) | |
2641 | return ZERO_SIZE_PTR; | |
2642 | ||
2643 | index = size_index[size_index_elem(size)]; | |
2644 | } else | |
2645 | index = fls(size - 1); | |
2646 | ||
2647 | #ifdef CONFIG_ZONE_DMA | |
2648 | if (unlikely((flags & SLUB_DMA))) | |
2649 | return kmalloc_dma_caches[index]; | |
2650 | ||
2651 | #endif | |
2652 | return kmalloc_caches[index]; | |
2653 | } | |
2654 | ||
2655 | void *__kmalloc(size_t size, gfp_t flags) | |
2656 | { | |
2657 | struct kmem_cache *s; | |
2658 | void *ret; | |
2659 | ||
2660 | if (unlikely(size > SLUB_MAX_SIZE)) | |
2661 | return kmalloc_large(size, flags); | |
2662 | ||
2663 | s = get_slab(size, flags); | |
2664 | ||
2665 | if (unlikely(ZERO_OR_NULL_PTR(s))) | |
2666 | return s; | |
2667 | ||
2668 | ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_); | |
2669 | ||
2670 | trace_kmalloc(_RET_IP_, ret, size, s->size, flags); | |
2671 | ||
2672 | return ret; | |
2673 | } | |
2674 | EXPORT_SYMBOL(__kmalloc); | |
2675 | ||
2676 | #ifdef CONFIG_NUMA | |
2677 | static void *kmalloc_large_node(size_t size, gfp_t flags, int node) | |
2678 | { | |
2679 | struct page *page; | |
2680 | void *ptr = NULL; | |
2681 | ||
2682 | flags |= __GFP_COMP | __GFP_NOTRACK; | |
2683 | page = alloc_pages_node(node, flags, get_order(size)); | |
2684 | if (page) | |
2685 | ptr = page_address(page); | |
2686 | ||
2687 | kmemleak_alloc(ptr, size, 1, flags); | |
2688 | return ptr; | |
2689 | } | |
2690 | ||
2691 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
2692 | { | |
2693 | struct kmem_cache *s; | |
2694 | void *ret; | |
2695 | ||
2696 | if (unlikely(size > SLUB_MAX_SIZE)) { | |
2697 | ret = kmalloc_large_node(size, flags, node); | |
2698 | ||
2699 | trace_kmalloc_node(_RET_IP_, ret, | |
2700 | size, PAGE_SIZE << get_order(size), | |
2701 | flags, node); | |
2702 | ||
2703 | return ret; | |
2704 | } | |
2705 | ||
2706 | s = get_slab(size, flags); | |
2707 | ||
2708 | if (unlikely(ZERO_OR_NULL_PTR(s))) | |
2709 | return s; | |
2710 | ||
2711 | ret = slab_alloc(s, flags, node, _RET_IP_); | |
2712 | ||
2713 | trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node); | |
2714 | ||
2715 | return ret; | |
2716 | } | |
2717 | EXPORT_SYMBOL(__kmalloc_node); | |
2718 | #endif | |
2719 | ||
2720 | size_t ksize(const void *object) | |
2721 | { | |
2722 | struct page *page; | |
2723 | struct kmem_cache *s; | |
2724 | ||
2725 | if (unlikely(object == ZERO_SIZE_PTR)) | |
2726 | return 0; | |
2727 | ||
2728 | page = virt_to_head_page(object); | |
2729 | ||
2730 | if (unlikely(!PageSlab(page))) { | |
2731 | WARN_ON(!PageCompound(page)); | |
2732 | return PAGE_SIZE << compound_order(page); | |
2733 | } | |
2734 | s = page->slab; | |
2735 | ||
2736 | #ifdef CONFIG_SLUB_DEBUG | |
2737 | /* | |
2738 | * Debugging requires use of the padding between object | |
2739 | * and whatever may come after it. | |
2740 | */ | |
2741 | if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) | |
2742 | return s->objsize; | |
2743 | ||
2744 | #endif | |
2745 | /* | |
2746 | * If we have the need to store the freelist pointer | |
2747 | * back there or track user information then we can | |
2748 | * only use the space before that information. | |
2749 | */ | |
2750 | if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) | |
2751 | return s->inuse; | |
2752 | /* | |
2753 | * Else we can use all the padding etc for the allocation | |
2754 | */ | |
2755 | return s->size; | |
2756 | } | |
2757 | EXPORT_SYMBOL(ksize); | |
2758 | ||
2759 | void kfree(const void *x) | |
2760 | { | |
2761 | struct page *page; | |
2762 | void *object = (void *)x; | |
2763 | ||
2764 | trace_kfree(_RET_IP_, x); | |
2765 | ||
2766 | if (unlikely(ZERO_OR_NULL_PTR(x))) | |
2767 | return; | |
2768 | ||
2769 | page = virt_to_head_page(x); | |
2770 | if (unlikely(!PageSlab(page))) { | |
2771 | BUG_ON(!PageCompound(page)); | |
2772 | kmemleak_free(x); | |
2773 | put_page(page); | |
2774 | return; | |
2775 | } | |
2776 | slab_free(page->slab, page, object, _RET_IP_); | |
2777 | } | |
2778 | EXPORT_SYMBOL(kfree); | |
2779 | ||
2780 | /* | |
2781 | * kmem_cache_shrink removes empty slabs from the partial lists and sorts | |
2782 | * the remaining slabs by the number of items in use. The slabs with the | |
2783 | * most items in use come first. New allocations will then fill those up | |
2784 | * and thus they can be removed from the partial lists. | |
2785 | * | |
2786 | * The slabs with the least items are placed last. This results in them | |
2787 | * being allocated from last increasing the chance that the last objects | |
2788 | * are freed in them. | |
2789 | */ | |
2790 | int kmem_cache_shrink(struct kmem_cache *s) | |
2791 | { | |
2792 | int node; | |
2793 | int i; | |
2794 | struct kmem_cache_node *n; | |
2795 | struct page *page; | |
2796 | struct page *t; | |
2797 | int objects = oo_objects(s->max); | |
2798 | struct list_head *slabs_by_inuse = | |
2799 | kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL); | |
2800 | unsigned long flags; | |
2801 | ||
2802 | if (!slabs_by_inuse) | |
2803 | return -ENOMEM; | |
2804 | ||
2805 | flush_all(s); | |
2806 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
2807 | n = get_node(s, node); | |
2808 | ||
2809 | if (!n->nr_partial) | |
2810 | continue; | |
2811 | ||
2812 | for (i = 0; i < objects; i++) | |
2813 | INIT_LIST_HEAD(slabs_by_inuse + i); | |
2814 | ||
2815 | spin_lock_irqsave(&n->list_lock, flags); | |
2816 | ||
2817 | /* | |
2818 | * Build lists indexed by the items in use in each slab. | |
2819 | * | |
2820 | * Note that concurrent frees may occur while we hold the | |
2821 | * list_lock. page->inuse here is the upper limit. | |
2822 | */ | |
2823 | list_for_each_entry_safe(page, t, &n->partial, lru) { | |
2824 | if (!page->inuse && slab_trylock(page)) { | |
2825 | /* | |
2826 | * Must hold slab lock here because slab_free | |
2827 | * may have freed the last object and be | |
2828 | * waiting to release the slab. | |
2829 | */ | |
2830 | __remove_partial(n, page); | |
2831 | slab_unlock(page); | |
2832 | discard_slab(s, page); | |
2833 | } else { | |
2834 | list_move(&page->lru, | |
2835 | slabs_by_inuse + page->inuse); | |
2836 | } | |
2837 | } | |
2838 | ||
2839 | /* | |
2840 | * Rebuild the partial list with the slabs filled up most | |
2841 | * first and the least used slabs at the end. | |
2842 | */ | |
2843 | for (i = objects - 1; i >= 0; i--) | |
2844 | list_splice(slabs_by_inuse + i, n->partial.prev); | |
2845 | ||
2846 | spin_unlock_irqrestore(&n->list_lock, flags); | |
2847 | } | |
2848 | ||
2849 | kfree(slabs_by_inuse); | |
2850 | return 0; | |
2851 | } | |
2852 | EXPORT_SYMBOL(kmem_cache_shrink); | |
2853 | ||
2854 | #if defined(CONFIG_MEMORY_HOTPLUG) | |
2855 | static int slab_mem_going_offline_callback(void *arg) | |
2856 | { | |
2857 | struct kmem_cache *s; | |
2858 | ||
2859 | down_read(&slub_lock); | |
2860 | list_for_each_entry(s, &slab_caches, list) | |
2861 | kmem_cache_shrink(s); | |
2862 | up_read(&slub_lock); | |
2863 | ||
2864 | return 0; | |
2865 | } | |
2866 | ||
2867 | static void slab_mem_offline_callback(void *arg) | |
2868 | { | |
2869 | struct kmem_cache_node *n; | |
2870 | struct kmem_cache *s; | |
2871 | struct memory_notify *marg = arg; | |
2872 | int offline_node; | |
2873 | ||
2874 | offline_node = marg->status_change_nid; | |
2875 | ||
2876 | /* | |
2877 | * If the node still has available memory. we need kmem_cache_node | |
2878 | * for it yet. | |
2879 | */ | |
2880 | if (offline_node < 0) | |
2881 | return; | |
2882 | ||
2883 | down_read(&slub_lock); | |
2884 | list_for_each_entry(s, &slab_caches, list) { | |
2885 | n = get_node(s, offline_node); | |
2886 | if (n) { | |
2887 | /* | |
2888 | * if n->nr_slabs > 0, slabs still exist on the node | |
2889 | * that is going down. We were unable to free them, | |
2890 | * and offline_pages() function shouldn't call this | |
2891 | * callback. So, we must fail. | |
2892 | */ | |
2893 | BUG_ON(slabs_node(s, offline_node)); | |
2894 | ||
2895 | s->node[offline_node] = NULL; | |
2896 | kmem_cache_free(kmem_cache_node, n); | |
2897 | } | |
2898 | } | |
2899 | up_read(&slub_lock); | |
2900 | } | |
2901 | ||
2902 | static int slab_mem_going_online_callback(void *arg) | |
2903 | { | |
2904 | struct kmem_cache_node *n; | |
2905 | struct kmem_cache *s; | |
2906 | struct memory_notify *marg = arg; | |
2907 | int nid = marg->status_change_nid; | |
2908 | int ret = 0; | |
2909 | ||
2910 | /* | |
2911 | * If the node's memory is already available, then kmem_cache_node is | |
2912 | * already created. Nothing to do. | |
2913 | */ | |
2914 | if (nid < 0) | |
2915 | return 0; | |
2916 | ||
2917 | /* | |
2918 | * We are bringing a node online. No memory is available yet. We must | |
2919 | * allocate a kmem_cache_node structure in order to bring the node | |
2920 | * online. | |
2921 | */ | |
2922 | down_read(&slub_lock); | |
2923 | list_for_each_entry(s, &slab_caches, list) { | |
2924 | /* | |
2925 | * XXX: kmem_cache_alloc_node will fallback to other nodes | |
2926 | * since memory is not yet available from the node that | |
2927 | * is brought up. | |
2928 | */ | |
2929 | n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL); | |
2930 | if (!n) { | |
2931 | ret = -ENOMEM; | |
2932 | goto out; | |
2933 | } | |
2934 | init_kmem_cache_node(n, s); | |
2935 | s->node[nid] = n; | |
2936 | } | |
2937 | out: | |
2938 | up_read(&slub_lock); | |
2939 | return ret; | |
2940 | } | |
2941 | ||
2942 | static int slab_memory_callback(struct notifier_block *self, | |
2943 | unsigned long action, void *arg) | |
2944 | { | |
2945 | int ret = 0; | |
2946 | ||
2947 | switch (action) { | |
2948 | case MEM_GOING_ONLINE: | |
2949 | ret = slab_mem_going_online_callback(arg); | |
2950 | break; | |
2951 | case MEM_GOING_OFFLINE: | |
2952 | ret = slab_mem_going_offline_callback(arg); | |
2953 | break; | |
2954 | case MEM_OFFLINE: | |
2955 | case MEM_CANCEL_ONLINE: | |
2956 | slab_mem_offline_callback(arg); | |
2957 | break; | |
2958 | case MEM_ONLINE: | |
2959 | case MEM_CANCEL_OFFLINE: | |
2960 | break; | |
2961 | } | |
2962 | if (ret) | |
2963 | ret = notifier_from_errno(ret); | |
2964 | else | |
2965 | ret = NOTIFY_OK; | |
2966 | return ret; | |
2967 | } | |
2968 | ||
2969 | #endif /* CONFIG_MEMORY_HOTPLUG */ | |
2970 | ||
2971 | /******************************************************************** | |
2972 | * Basic setup of slabs | |
2973 | *******************************************************************/ | |
2974 | ||
2975 | /* | |
2976 | * Used for early kmem_cache structures that were allocated using | |
2977 | * the page allocator | |
2978 | */ | |
2979 | ||
2980 | static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s) | |
2981 | { | |
2982 | int node; | |
2983 | ||
2984 | list_add(&s->list, &slab_caches); | |
2985 | s->refcount = -1; | |
2986 | ||
2987 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
2988 | struct kmem_cache_node *n = get_node(s, node); | |
2989 | struct page *p; | |
2990 | ||
2991 | if (n) { | |
2992 | list_for_each_entry(p, &n->partial, lru) | |
2993 | p->slab = s; | |
2994 | ||
2995 | #ifdef CONFIG_SLAB_DEBUG | |
2996 | list_for_each_entry(p, &n->full, lru) | |
2997 | p->slab = s; | |
2998 | #endif | |
2999 | } | |
3000 | } | |
3001 | } | |
3002 | ||
3003 | void __init kmem_cache_init(void) | |
3004 | { | |
3005 | int i; | |
3006 | int caches = 0; | |
3007 | struct kmem_cache *temp_kmem_cache; | |
3008 | int order; | |
3009 | struct kmem_cache *temp_kmem_cache_node; | |
3010 | unsigned long kmalloc_size; | |
3011 | ||
3012 | kmem_size = offsetof(struct kmem_cache, node) + | |
3013 | nr_node_ids * sizeof(struct kmem_cache_node *); | |
3014 | ||
3015 | /* Allocate two kmem_caches from the page allocator */ | |
3016 | kmalloc_size = ALIGN(kmem_size, cache_line_size()); | |
3017 | order = get_order(2 * kmalloc_size); | |
3018 | kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order); | |
3019 | ||
3020 | /* | |
3021 | * Must first have the slab cache available for the allocations of the | |
3022 | * struct kmem_cache_node's. There is special bootstrap code in | |
3023 | * kmem_cache_open for slab_state == DOWN. | |
3024 | */ | |
3025 | kmem_cache_node = (void *)kmem_cache + kmalloc_size; | |
3026 | ||
3027 | kmem_cache_open(kmem_cache_node, "kmem_cache_node", | |
3028 | sizeof(struct kmem_cache_node), | |
3029 | 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); | |
3030 | ||
3031 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); | |
3032 | ||
3033 | /* Able to allocate the per node structures */ | |
3034 | slab_state = PARTIAL; | |
3035 | ||
3036 | temp_kmem_cache = kmem_cache; | |
3037 | kmem_cache_open(kmem_cache, "kmem_cache", kmem_size, | |
3038 | 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); | |
3039 | kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT); | |
3040 | memcpy(kmem_cache, temp_kmem_cache, kmem_size); | |
3041 | ||
3042 | /* | |
3043 | * Allocate kmem_cache_node properly from the kmem_cache slab. | |
3044 | * kmem_cache_node is separately allocated so no need to | |
3045 | * update any list pointers. | |
3046 | */ | |
3047 | temp_kmem_cache_node = kmem_cache_node; | |
3048 | ||
3049 | kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT); | |
3050 | memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size); | |
3051 | ||
3052 | kmem_cache_bootstrap_fixup(kmem_cache_node); | |
3053 | ||
3054 | caches++; | |
3055 | kmem_cache_bootstrap_fixup(kmem_cache); | |
3056 | caches++; | |
3057 | /* Free temporary boot structure */ | |
3058 | free_pages((unsigned long)temp_kmem_cache, order); | |
3059 | ||
3060 | /* Now we can use the kmem_cache to allocate kmalloc slabs */ | |
3061 | ||
3062 | /* | |
3063 | * Patch up the size_index table if we have strange large alignment | |
3064 | * requirements for the kmalloc array. This is only the case for | |
3065 | * MIPS it seems. The standard arches will not generate any code here. | |
3066 | * | |
3067 | * Largest permitted alignment is 256 bytes due to the way we | |
3068 | * handle the index determination for the smaller caches. | |
3069 | * | |
3070 | * Make sure that nothing crazy happens if someone starts tinkering | |
3071 | * around with ARCH_KMALLOC_MINALIGN | |
3072 | */ | |
3073 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || | |
3074 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); | |
3075 | ||
3076 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { | |
3077 | int elem = size_index_elem(i); | |
3078 | if (elem >= ARRAY_SIZE(size_index)) | |
3079 | break; | |
3080 | size_index[elem] = KMALLOC_SHIFT_LOW; | |
3081 | } | |
3082 | ||
3083 | if (KMALLOC_MIN_SIZE == 64) { | |
3084 | /* | |
3085 | * The 96 byte size cache is not used if the alignment | |
3086 | * is 64 byte. | |
3087 | */ | |
3088 | for (i = 64 + 8; i <= 96; i += 8) | |
3089 | size_index[size_index_elem(i)] = 7; | |
3090 | } else if (KMALLOC_MIN_SIZE == 128) { | |
3091 | /* | |
3092 | * The 192 byte sized cache is not used if the alignment | |
3093 | * is 128 byte. Redirect kmalloc to use the 256 byte cache | |
3094 | * instead. | |
3095 | */ | |
3096 | for (i = 128 + 8; i <= 192; i += 8) | |
3097 | size_index[size_index_elem(i)] = 8; | |
3098 | } | |
3099 | ||
3100 | /* Caches that are not of the two-to-the-power-of size */ | |
3101 | if (KMALLOC_MIN_SIZE <= 32) { | |
3102 | kmalloc_caches[1] = create_kmalloc_cache("kmalloc-96", 96, 0); | |
3103 | caches++; | |
3104 | } | |
3105 | ||
3106 | if (KMALLOC_MIN_SIZE <= 64) { | |
3107 | kmalloc_caches[2] = create_kmalloc_cache("kmalloc-192", 192, 0); | |
3108 | caches++; | |
3109 | } | |
3110 | ||
3111 | for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) { | |
3112 | kmalloc_caches[i] = create_kmalloc_cache("kmalloc", 1 << i, 0); | |
3113 | caches++; | |
3114 | } | |
3115 | ||
3116 | slab_state = UP; | |
3117 | ||
3118 | /* Provide the correct kmalloc names now that the caches are up */ | |
3119 | if (KMALLOC_MIN_SIZE <= 32) { | |
3120 | kmalloc_caches[1]->name = kstrdup(kmalloc_caches[1]->name, GFP_NOWAIT); | |
3121 | BUG_ON(!kmalloc_caches[1]->name); | |
3122 | } | |
3123 | ||
3124 | if (KMALLOC_MIN_SIZE <= 64) { | |
3125 | kmalloc_caches[2]->name = kstrdup(kmalloc_caches[2]->name, GFP_NOWAIT); | |
3126 | BUG_ON(!kmalloc_caches[2]->name); | |
3127 | } | |
3128 | ||
3129 | for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) { | |
3130 | char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i); | |
3131 | ||
3132 | BUG_ON(!s); | |
3133 | kmalloc_caches[i]->name = s; | |
3134 | } | |
3135 | ||
3136 | #ifdef CONFIG_SMP | |
3137 | register_cpu_notifier(&slab_notifier); | |
3138 | #endif | |
3139 | ||
3140 | #ifdef CONFIG_ZONE_DMA | |
3141 | for (i = 0; i < SLUB_PAGE_SHIFT; i++) { | |
3142 | struct kmem_cache *s = kmalloc_caches[i]; | |
3143 | ||
3144 | if (s && s->size) { | |
3145 | char *name = kasprintf(GFP_NOWAIT, | |
3146 | "dma-kmalloc-%d", s->objsize); | |
3147 | ||
3148 | BUG_ON(!name); | |
3149 | kmalloc_dma_caches[i] = create_kmalloc_cache(name, | |
3150 | s->objsize, SLAB_CACHE_DMA); | |
3151 | } | |
3152 | } | |
3153 | #endif | |
3154 | printk(KERN_INFO | |
3155 | "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," | |
3156 | " CPUs=%d, Nodes=%d\n", | |
3157 | caches, cache_line_size(), | |
3158 | slub_min_order, slub_max_order, slub_min_objects, | |
3159 | nr_cpu_ids, nr_node_ids); | |
3160 | } | |
3161 | ||
3162 | void __init kmem_cache_init_late(void) | |
3163 | { | |
3164 | } | |
3165 | ||
3166 | /* | |
3167 | * Find a mergeable slab cache | |
3168 | */ | |
3169 | static int slab_unmergeable(struct kmem_cache *s) | |
3170 | { | |
3171 | if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) | |
3172 | return 1; | |
3173 | ||
3174 | if (s->ctor) | |
3175 | return 1; | |
3176 | ||
3177 | /* | |
3178 | * We may have set a slab to be unmergeable during bootstrap. | |
3179 | */ | |
3180 | if (s->refcount < 0) | |
3181 | return 1; | |
3182 | ||
3183 | return 0; | |
3184 | } | |
3185 | ||
3186 | static struct kmem_cache *find_mergeable(size_t size, | |
3187 | size_t align, unsigned long flags, const char *name, | |
3188 | void (*ctor)(void *)) | |
3189 | { | |
3190 | struct kmem_cache *s; | |
3191 | ||
3192 | if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) | |
3193 | return NULL; | |
3194 | ||
3195 | if (ctor) | |
3196 | return NULL; | |
3197 | ||
3198 | size = ALIGN(size, sizeof(void *)); | |
3199 | align = calculate_alignment(flags, align, size); | |
3200 | size = ALIGN(size, align); | |
3201 | flags = kmem_cache_flags(size, flags, name, NULL); | |
3202 | ||
3203 | list_for_each_entry(s, &slab_caches, list) { | |
3204 | if (slab_unmergeable(s)) | |
3205 | continue; | |
3206 | ||
3207 | if (size > s->size) | |
3208 | continue; | |
3209 | ||
3210 | if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) | |
3211 | continue; | |
3212 | /* | |
3213 | * Check if alignment is compatible. | |
3214 | * Courtesy of Adrian Drzewiecki | |
3215 | */ | |
3216 | if ((s->size & ~(align - 1)) != s->size) | |
3217 | continue; | |
3218 | ||
3219 | if (s->size - size >= sizeof(void *)) | |
3220 | continue; | |
3221 | ||
3222 | return s; | |
3223 | } | |
3224 | return NULL; | |
3225 | } | |
3226 | ||
3227 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |
3228 | size_t align, unsigned long flags, void (*ctor)(void *)) | |
3229 | { | |
3230 | struct kmem_cache *s; | |
3231 | char *n; | |
3232 | ||
3233 | if (WARN_ON(!name)) | |
3234 | return NULL; | |
3235 | ||
3236 | down_write(&slub_lock); | |
3237 | s = find_mergeable(size, align, flags, name, ctor); | |
3238 | if (s) { | |
3239 | s->refcount++; | |
3240 | /* | |
3241 | * Adjust the object sizes so that we clear | |
3242 | * the complete object on kzalloc. | |
3243 | */ | |
3244 | s->objsize = max(s->objsize, (int)size); | |
3245 | s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *))); | |
3246 | ||
3247 | if (sysfs_slab_alias(s, name)) { | |
3248 | s->refcount--; | |
3249 | goto err; | |
3250 | } | |
3251 | up_write(&slub_lock); | |
3252 | return s; | |
3253 | } | |
3254 | ||
3255 | n = kstrdup(name, GFP_KERNEL); | |
3256 | if (!n) | |
3257 | goto err; | |
3258 | ||
3259 | s = kmalloc(kmem_size, GFP_KERNEL); | |
3260 | if (s) { | |
3261 | if (kmem_cache_open(s, n, | |
3262 | size, align, flags, ctor)) { | |
3263 | list_add(&s->list, &slab_caches); | |
3264 | if (sysfs_slab_add(s)) { | |
3265 | list_del(&s->list); | |
3266 | kfree(n); | |
3267 | kfree(s); | |
3268 | goto err; | |
3269 | } | |
3270 | up_write(&slub_lock); | |
3271 | return s; | |
3272 | } | |
3273 | kfree(n); | |
3274 | kfree(s); | |
3275 | } | |
3276 | err: | |
3277 | up_write(&slub_lock); | |
3278 | ||
3279 | if (flags & SLAB_PANIC) | |
3280 | panic("Cannot create slabcache %s\n", name); | |
3281 | else | |
3282 | s = NULL; | |
3283 | return s; | |
3284 | } | |
3285 | EXPORT_SYMBOL(kmem_cache_create); | |
3286 | ||
3287 | #ifdef CONFIG_SMP | |
3288 | /* | |
3289 | * Use the cpu notifier to insure that the cpu slabs are flushed when | |
3290 | * necessary. | |
3291 | */ | |
3292 | static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb, | |
3293 | unsigned long action, void *hcpu) | |
3294 | { | |
3295 | long cpu = (long)hcpu; | |
3296 | struct kmem_cache *s; | |
3297 | unsigned long flags; | |
3298 | ||
3299 | switch (action) { | |
3300 | case CPU_UP_CANCELED: | |
3301 | case CPU_UP_CANCELED_FROZEN: | |
3302 | case CPU_DEAD: | |
3303 | case CPU_DEAD_FROZEN: | |
3304 | down_read(&slub_lock); | |
3305 | list_for_each_entry(s, &slab_caches, list) { | |
3306 | local_irq_save(flags); | |
3307 | __flush_cpu_slab(s, cpu); | |
3308 | local_irq_restore(flags); | |
3309 | } | |
3310 | up_read(&slub_lock); | |
3311 | break; | |
3312 | default: | |
3313 | break; | |
3314 | } | |
3315 | return NOTIFY_OK; | |
3316 | } | |
3317 | ||
3318 | static struct notifier_block __cpuinitdata slab_notifier = { | |
3319 | .notifier_call = slab_cpuup_callback | |
3320 | }; | |
3321 | ||
3322 | #endif | |
3323 | ||
3324 | void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller) | |
3325 | { | |
3326 | struct kmem_cache *s; | |
3327 | void *ret; | |
3328 | ||
3329 | if (unlikely(size > SLUB_MAX_SIZE)) | |
3330 | return kmalloc_large(size, gfpflags); | |
3331 | ||
3332 | s = get_slab(size, gfpflags); | |
3333 | ||
3334 | if (unlikely(ZERO_OR_NULL_PTR(s))) | |
3335 | return s; | |
3336 | ||
3337 | ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller); | |
3338 | ||
3339 | /* Honor the call site pointer we recieved. */ | |
3340 | trace_kmalloc(caller, ret, size, s->size, gfpflags); | |
3341 | ||
3342 | return ret; | |
3343 | } | |
3344 | ||
3345 | #ifdef CONFIG_NUMA | |
3346 | void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, | |
3347 | int node, unsigned long caller) | |
3348 | { | |
3349 | struct kmem_cache *s; | |
3350 | void *ret; | |
3351 | ||
3352 | if (unlikely(size > SLUB_MAX_SIZE)) { | |
3353 | ret = kmalloc_large_node(size, gfpflags, node); | |
3354 | ||
3355 | trace_kmalloc_node(caller, ret, | |
3356 | size, PAGE_SIZE << get_order(size), | |
3357 | gfpflags, node); | |
3358 | ||
3359 | return ret; | |
3360 | } | |
3361 | ||
3362 | s = get_slab(size, gfpflags); | |
3363 | ||
3364 | if (unlikely(ZERO_OR_NULL_PTR(s))) | |
3365 | return s; | |
3366 | ||
3367 | ret = slab_alloc(s, gfpflags, node, caller); | |
3368 | ||
3369 | /* Honor the call site pointer we recieved. */ | |
3370 | trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node); | |
3371 | ||
3372 | return ret; | |
3373 | } | |
3374 | #endif | |
3375 | ||
3376 | #ifdef CONFIG_SYSFS | |
3377 | static int count_inuse(struct page *page) | |
3378 | { | |
3379 | return page->inuse; | |
3380 | } | |
3381 | ||
3382 | static int count_total(struct page *page) | |
3383 | { | |
3384 | return page->objects; | |
3385 | } | |
3386 | #endif | |
3387 | ||
3388 | #ifdef CONFIG_SLUB_DEBUG | |
3389 | static int validate_slab(struct kmem_cache *s, struct page *page, | |
3390 | unsigned long *map) | |
3391 | { | |
3392 | void *p; | |
3393 | void *addr = page_address(page); | |
3394 | ||
3395 | if (!check_slab(s, page) || | |
3396 | !on_freelist(s, page, NULL)) | |
3397 | return 0; | |
3398 | ||
3399 | /* Now we know that a valid freelist exists */ | |
3400 | bitmap_zero(map, page->objects); | |
3401 | ||
3402 | for_each_free_object(p, s, page->freelist) { | |
3403 | set_bit(slab_index(p, s, addr), map); | |
3404 | if (!check_object(s, page, p, 0)) | |
3405 | return 0; | |
3406 | } | |
3407 | ||
3408 | for_each_object(p, s, addr, page->objects) | |
3409 | if (!test_bit(slab_index(p, s, addr), map)) | |
3410 | if (!check_object(s, page, p, 1)) | |
3411 | return 0; | |
3412 | return 1; | |
3413 | } | |
3414 | ||
3415 | static void validate_slab_slab(struct kmem_cache *s, struct page *page, | |
3416 | unsigned long *map) | |
3417 | { | |
3418 | if (slab_trylock(page)) { | |
3419 | validate_slab(s, page, map); | |
3420 | slab_unlock(page); | |
3421 | } else | |
3422 | printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n", | |
3423 | s->name, page); | |
3424 | } | |
3425 | ||
3426 | static int validate_slab_node(struct kmem_cache *s, | |
3427 | struct kmem_cache_node *n, unsigned long *map) | |
3428 | { | |
3429 | unsigned long count = 0; | |
3430 | struct page *page; | |
3431 | unsigned long flags; | |
3432 | ||
3433 | spin_lock_irqsave(&n->list_lock, flags); | |
3434 | ||
3435 | list_for_each_entry(page, &n->partial, lru) { | |
3436 | validate_slab_slab(s, page, map); | |
3437 | count++; | |
3438 | } | |
3439 | if (count != n->nr_partial) | |
3440 | printk(KERN_ERR "SLUB %s: %ld partial slabs counted but " | |
3441 | "counter=%ld\n", s->name, count, n->nr_partial); | |
3442 | ||
3443 | if (!(s->flags & SLAB_STORE_USER)) | |
3444 | goto out; | |
3445 | ||
3446 | list_for_each_entry(page, &n->full, lru) { | |
3447 | validate_slab_slab(s, page, map); | |
3448 | count++; | |
3449 | } | |
3450 | if (count != atomic_long_read(&n->nr_slabs)) | |
3451 | printk(KERN_ERR "SLUB: %s %ld slabs counted but " | |
3452 | "counter=%ld\n", s->name, count, | |
3453 | atomic_long_read(&n->nr_slabs)); | |
3454 | ||
3455 | out: | |
3456 | spin_unlock_irqrestore(&n->list_lock, flags); | |
3457 | return count; | |
3458 | } | |
3459 | ||
3460 | static long validate_slab_cache(struct kmem_cache *s) | |
3461 | { | |
3462 | int node; | |
3463 | unsigned long count = 0; | |
3464 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * | |
3465 | sizeof(unsigned long), GFP_KERNEL); | |
3466 | ||
3467 | if (!map) | |
3468 | return -ENOMEM; | |
3469 | ||
3470 | flush_all(s); | |
3471 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
3472 | struct kmem_cache_node *n = get_node(s, node); | |
3473 | ||
3474 | count += validate_slab_node(s, n, map); | |
3475 | } | |
3476 | kfree(map); | |
3477 | return count; | |
3478 | } | |
3479 | /* | |
3480 | * Generate lists of code addresses where slabcache objects are allocated | |
3481 | * and freed. | |
3482 | */ | |
3483 | ||
3484 | struct location { | |
3485 | unsigned long count; | |
3486 | unsigned long addr; | |
3487 | long long sum_time; | |
3488 | long min_time; | |
3489 | long max_time; | |
3490 | long min_pid; | |
3491 | long max_pid; | |
3492 | DECLARE_BITMAP(cpus, NR_CPUS); | |
3493 | nodemask_t nodes; | |
3494 | }; | |
3495 | ||
3496 | struct loc_track { | |
3497 | unsigned long max; | |
3498 | unsigned long count; | |
3499 | struct location *loc; | |
3500 | }; | |
3501 | ||
3502 | static void free_loc_track(struct loc_track *t) | |
3503 | { | |
3504 | if (t->max) | |
3505 | free_pages((unsigned long)t->loc, | |
3506 | get_order(sizeof(struct location) * t->max)); | |
3507 | } | |
3508 | ||
3509 | static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags) | |
3510 | { | |
3511 | struct location *l; | |
3512 | int order; | |
3513 | ||
3514 | order = get_order(sizeof(struct location) * max); | |
3515 | ||
3516 | l = (void *)__get_free_pages(flags, order); | |
3517 | if (!l) | |
3518 | return 0; | |
3519 | ||
3520 | if (t->count) { | |
3521 | memcpy(l, t->loc, sizeof(struct location) * t->count); | |
3522 | free_loc_track(t); | |
3523 | } | |
3524 | t->max = max; | |
3525 | t->loc = l; | |
3526 | return 1; | |
3527 | } | |
3528 | ||
3529 | static int add_location(struct loc_track *t, struct kmem_cache *s, | |
3530 | const struct track *track) | |
3531 | { | |
3532 | long start, end, pos; | |
3533 | struct location *l; | |
3534 | unsigned long caddr; | |
3535 | unsigned long age = jiffies - track->when; | |
3536 | ||
3537 | start = -1; | |
3538 | end = t->count; | |
3539 | ||
3540 | for ( ; ; ) { | |
3541 | pos = start + (end - start + 1) / 2; | |
3542 | ||
3543 | /* | |
3544 | * There is nothing at "end". If we end up there | |
3545 | * we need to add something to before end. | |
3546 | */ | |
3547 | if (pos == end) | |
3548 | break; | |
3549 | ||
3550 | caddr = t->loc[pos].addr; | |
3551 | if (track->addr == caddr) { | |
3552 | ||
3553 | l = &t->loc[pos]; | |
3554 | l->count++; | |
3555 | if (track->when) { | |
3556 | l->sum_time += age; | |
3557 | if (age < l->min_time) | |
3558 | l->min_time = age; | |
3559 | if (age > l->max_time) | |
3560 | l->max_time = age; | |
3561 | ||
3562 | if (track->pid < l->min_pid) | |
3563 | l->min_pid = track->pid; | |
3564 | if (track->pid > l->max_pid) | |
3565 | l->max_pid = track->pid; | |
3566 | ||
3567 | cpumask_set_cpu(track->cpu, | |
3568 | to_cpumask(l->cpus)); | |
3569 | } | |
3570 | node_set(page_to_nid(virt_to_page(track)), l->nodes); | |
3571 | return 1; | |
3572 | } | |
3573 | ||
3574 | if (track->addr < caddr) | |
3575 | end = pos; | |
3576 | else | |
3577 | start = pos; | |
3578 | } | |
3579 | ||
3580 | /* | |
3581 | * Not found. Insert new tracking element. | |
3582 | */ | |
3583 | if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC)) | |
3584 | return 0; | |
3585 | ||
3586 | l = t->loc + pos; | |
3587 | if (pos < t->count) | |
3588 | memmove(l + 1, l, | |
3589 | (t->count - pos) * sizeof(struct location)); | |
3590 | t->count++; | |
3591 | l->count = 1; | |
3592 | l->addr = track->addr; | |
3593 | l->sum_time = age; | |
3594 | l->min_time = age; | |
3595 | l->max_time = age; | |
3596 | l->min_pid = track->pid; | |
3597 | l->max_pid = track->pid; | |
3598 | cpumask_clear(to_cpumask(l->cpus)); | |
3599 | cpumask_set_cpu(track->cpu, to_cpumask(l->cpus)); | |
3600 | nodes_clear(l->nodes); | |
3601 | node_set(page_to_nid(virt_to_page(track)), l->nodes); | |
3602 | return 1; | |
3603 | } | |
3604 | ||
3605 | static void process_slab(struct loc_track *t, struct kmem_cache *s, | |
3606 | struct page *page, enum track_item alloc, | |
3607 | unsigned long *map) | |
3608 | { | |
3609 | void *addr = page_address(page); | |
3610 | void *p; | |
3611 | ||
3612 | bitmap_zero(map, page->objects); | |
3613 | for_each_free_object(p, s, page->freelist) | |
3614 | set_bit(slab_index(p, s, addr), map); | |
3615 | ||
3616 | for_each_object(p, s, addr, page->objects) | |
3617 | if (!test_bit(slab_index(p, s, addr), map)) | |
3618 | add_location(t, s, get_track(s, p, alloc)); | |
3619 | } | |
3620 | ||
3621 | static int list_locations(struct kmem_cache *s, char *buf, | |
3622 | enum track_item alloc) | |
3623 | { | |
3624 | int len = 0; | |
3625 | unsigned long i; | |
3626 | struct loc_track t = { 0, 0, NULL }; | |
3627 | int node; | |
3628 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * | |
3629 | sizeof(unsigned long), GFP_KERNEL); | |
3630 | ||
3631 | if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), | |
3632 | GFP_TEMPORARY)) { | |
3633 | kfree(map); | |
3634 | return sprintf(buf, "Out of memory\n"); | |
3635 | } | |
3636 | /* Push back cpu slabs */ | |
3637 | flush_all(s); | |
3638 | ||
3639 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
3640 | struct kmem_cache_node *n = get_node(s, node); | |
3641 | unsigned long flags; | |
3642 | struct page *page; | |
3643 | ||
3644 | if (!atomic_long_read(&n->nr_slabs)) | |
3645 | continue; | |
3646 | ||
3647 | spin_lock_irqsave(&n->list_lock, flags); | |
3648 | list_for_each_entry(page, &n->partial, lru) | |
3649 | process_slab(&t, s, page, alloc, map); | |
3650 | list_for_each_entry(page, &n->full, lru) | |
3651 | process_slab(&t, s, page, alloc, map); | |
3652 | spin_unlock_irqrestore(&n->list_lock, flags); | |
3653 | } | |
3654 | ||
3655 | for (i = 0; i < t.count; i++) { | |
3656 | struct location *l = &t.loc[i]; | |
3657 | ||
3658 | if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100) | |
3659 | break; | |
3660 | len += sprintf(buf + len, "%7ld ", l->count); | |
3661 | ||
3662 | if (l->addr) | |
3663 | len += sprint_symbol(buf + len, (unsigned long)l->addr); | |
3664 | else | |
3665 | len += sprintf(buf + len, "<not-available>"); | |
3666 | ||
3667 | if (l->sum_time != l->min_time) { | |
3668 | len += sprintf(buf + len, " age=%ld/%ld/%ld", | |
3669 | l->min_time, | |
3670 | (long)div_u64(l->sum_time, l->count), | |
3671 | l->max_time); | |
3672 | } else | |
3673 | len += sprintf(buf + len, " age=%ld", | |
3674 | l->min_time); | |
3675 | ||
3676 | if (l->min_pid != l->max_pid) | |
3677 | len += sprintf(buf + len, " pid=%ld-%ld", | |
3678 | l->min_pid, l->max_pid); | |
3679 | else | |
3680 | len += sprintf(buf + len, " pid=%ld", | |
3681 | l->min_pid); | |
3682 | ||
3683 | if (num_online_cpus() > 1 && | |
3684 | !cpumask_empty(to_cpumask(l->cpus)) && | |
3685 | len < PAGE_SIZE - 60) { | |
3686 | len += sprintf(buf + len, " cpus="); | |
3687 | len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50, | |
3688 | to_cpumask(l->cpus)); | |
3689 | } | |
3690 | ||
3691 | if (nr_online_nodes > 1 && !nodes_empty(l->nodes) && | |
3692 | len < PAGE_SIZE - 60) { | |
3693 | len += sprintf(buf + len, " nodes="); | |
3694 | len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50, | |
3695 | l->nodes); | |
3696 | } | |
3697 | ||
3698 | len += sprintf(buf + len, "\n"); | |
3699 | } | |
3700 | ||
3701 | free_loc_track(&t); | |
3702 | kfree(map); | |
3703 | if (!t.count) | |
3704 | len += sprintf(buf, "No data\n"); | |
3705 | return len; | |
3706 | } | |
3707 | #endif | |
3708 | ||
3709 | #ifdef SLUB_RESILIENCY_TEST | |
3710 | static void resiliency_test(void) | |
3711 | { | |
3712 | u8 *p; | |
3713 | ||
3714 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || SLUB_PAGE_SHIFT < 10); | |
3715 | ||
3716 | printk(KERN_ERR "SLUB resiliency testing\n"); | |
3717 | printk(KERN_ERR "-----------------------\n"); | |
3718 | printk(KERN_ERR "A. Corruption after allocation\n"); | |
3719 | ||
3720 | p = kzalloc(16, GFP_KERNEL); | |
3721 | p[16] = 0x12; | |
3722 | printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer" | |
3723 | " 0x12->0x%p\n\n", p + 16); | |
3724 | ||
3725 | validate_slab_cache(kmalloc_caches[4]); | |
3726 | ||
3727 | /* Hmmm... The next two are dangerous */ | |
3728 | p = kzalloc(32, GFP_KERNEL); | |
3729 | p[32 + sizeof(void *)] = 0x34; | |
3730 | printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab" | |
3731 | " 0x34 -> -0x%p\n", p); | |
3732 | printk(KERN_ERR | |
3733 | "If allocated object is overwritten then not detectable\n\n"); | |
3734 | ||
3735 | validate_slab_cache(kmalloc_caches[5]); | |
3736 | p = kzalloc(64, GFP_KERNEL); | |
3737 | p += 64 + (get_cycles() & 0xff) * sizeof(void *); | |
3738 | *p = 0x56; | |
3739 | printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n", | |
3740 | p); | |
3741 | printk(KERN_ERR | |
3742 | "If allocated object is overwritten then not detectable\n\n"); | |
3743 | validate_slab_cache(kmalloc_caches[6]); | |
3744 | ||
3745 | printk(KERN_ERR "\nB. Corruption after free\n"); | |
3746 | p = kzalloc(128, GFP_KERNEL); | |
3747 | kfree(p); | |
3748 | *p = 0x78; | |
3749 | printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p); | |
3750 | validate_slab_cache(kmalloc_caches[7]); | |
3751 | ||
3752 | p = kzalloc(256, GFP_KERNEL); | |
3753 | kfree(p); | |
3754 | p[50] = 0x9a; | |
3755 | printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", | |
3756 | p); | |
3757 | validate_slab_cache(kmalloc_caches[8]); | |
3758 | ||
3759 | p = kzalloc(512, GFP_KERNEL); | |
3760 | kfree(p); | |
3761 | p[512] = 0xab; | |
3762 | printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p); | |
3763 | validate_slab_cache(kmalloc_caches[9]); | |
3764 | } | |
3765 | #else | |
3766 | #ifdef CONFIG_SYSFS | |
3767 | static void resiliency_test(void) {}; | |
3768 | #endif | |
3769 | #endif | |
3770 | ||
3771 | #ifdef CONFIG_SYSFS | |
3772 | enum slab_stat_type { | |
3773 | SL_ALL, /* All slabs */ | |
3774 | SL_PARTIAL, /* Only partially allocated slabs */ | |
3775 | SL_CPU, /* Only slabs used for cpu caches */ | |
3776 | SL_OBJECTS, /* Determine allocated objects not slabs */ | |
3777 | SL_TOTAL /* Determine object capacity not slabs */ | |
3778 | }; | |
3779 | ||
3780 | #define SO_ALL (1 << SL_ALL) | |
3781 | #define SO_PARTIAL (1 << SL_PARTIAL) | |
3782 | #define SO_CPU (1 << SL_CPU) | |
3783 | #define SO_OBJECTS (1 << SL_OBJECTS) | |
3784 | #define SO_TOTAL (1 << SL_TOTAL) | |
3785 | ||
3786 | static ssize_t show_slab_objects(struct kmem_cache *s, | |
3787 | char *buf, unsigned long flags) | |
3788 | { | |
3789 | unsigned long total = 0; | |
3790 | int node; | |
3791 | int x; | |
3792 | unsigned long *nodes; | |
3793 | unsigned long *per_cpu; | |
3794 | ||
3795 | nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); | |
3796 | if (!nodes) | |
3797 | return -ENOMEM; | |
3798 | per_cpu = nodes + nr_node_ids; | |
3799 | ||
3800 | if (flags & SO_CPU) { | |
3801 | int cpu; | |
3802 | ||
3803 | for_each_possible_cpu(cpu) { | |
3804 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); | |
3805 | ||
3806 | if (!c || c->node < 0) | |
3807 | continue; | |
3808 | ||
3809 | if (c->page) { | |
3810 | if (flags & SO_TOTAL) | |
3811 | x = c->page->objects; | |
3812 | else if (flags & SO_OBJECTS) | |
3813 | x = c->page->inuse; | |
3814 | else | |
3815 | x = 1; | |
3816 | ||
3817 | total += x; | |
3818 | nodes[c->node] += x; | |
3819 | } | |
3820 | per_cpu[c->node]++; | |
3821 | } | |
3822 | } | |
3823 | ||
3824 | down_read(&slub_lock); | |
3825 | #ifdef CONFIG_SLUB_DEBUG | |
3826 | if (flags & SO_ALL) { | |
3827 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
3828 | struct kmem_cache_node *n = get_node(s, node); | |
3829 | ||
3830 | if (flags & SO_TOTAL) | |
3831 | x = atomic_long_read(&n->total_objects); | |
3832 | else if (flags & SO_OBJECTS) | |
3833 | x = atomic_long_read(&n->total_objects) - | |
3834 | count_partial(n, count_free); | |
3835 | ||
3836 | else | |
3837 | x = atomic_long_read(&n->nr_slabs); | |
3838 | total += x; | |
3839 | nodes[node] += x; | |
3840 | } | |
3841 | ||
3842 | } else | |
3843 | #endif | |
3844 | if (flags & SO_PARTIAL) { | |
3845 | for_each_node_state(node, N_NORMAL_MEMORY) { | |
3846 | struct kmem_cache_node *n = get_node(s, node); | |
3847 | ||
3848 | if (flags & SO_TOTAL) | |
3849 | x = count_partial(n, count_total); | |
3850 | else if (flags & SO_OBJECTS) | |
3851 | x = count_partial(n, count_inuse); | |
3852 | else | |
3853 | x = n->nr_partial; | |
3854 | total += x; | |
3855 | nodes[node] += x; | |
3856 | } | |
3857 | } | |
3858 | x = sprintf(buf, "%lu", total); | |
3859 | #ifdef CONFIG_NUMA | |
3860 | for_each_node_state(node, N_NORMAL_MEMORY) | |
3861 | if (nodes[node]) | |
3862 | x += sprintf(buf + x, " N%d=%lu", | |
3863 | node, nodes[node]); | |
3864 | #endif | |
3865 | up_read(&slub_lock); | |
3866 | kfree(nodes); | |
3867 | return x + sprintf(buf + x, "\n"); | |
3868 | } | |
3869 | ||
3870 | #ifdef CONFIG_SLUB_DEBUG | |
3871 | static int any_slab_objects(struct kmem_cache *s) | |
3872 | { | |
3873 | int node; | |
3874 | ||
3875 | for_each_online_node(node) { | |
3876 | struct kmem_cache_node *n = get_node(s, node); | |
3877 | ||
3878 | if (!n) | |
3879 | continue; | |
3880 | ||
3881 | if (atomic_long_read(&n->total_objects)) | |
3882 | return 1; | |
3883 | } | |
3884 | return 0; | |
3885 | } | |
3886 | #endif | |
3887 | ||
3888 | #define to_slab_attr(n) container_of(n, struct slab_attribute, attr) | |
3889 | #define to_slab(n) container_of(n, struct kmem_cache, kobj); | |
3890 | ||
3891 | struct slab_attribute { | |
3892 | struct attribute attr; | |
3893 | ssize_t (*show)(struct kmem_cache *s, char *buf); | |
3894 | ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); | |
3895 | }; | |
3896 | ||
3897 | #define SLAB_ATTR_RO(_name) \ | |
3898 | static struct slab_attribute _name##_attr = __ATTR_RO(_name) | |
3899 | ||
3900 | #define SLAB_ATTR(_name) \ | |
3901 | static struct slab_attribute _name##_attr = \ | |
3902 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
3903 | ||
3904 | static ssize_t slab_size_show(struct kmem_cache *s, char *buf) | |
3905 | { | |
3906 | return sprintf(buf, "%d\n", s->size); | |
3907 | } | |
3908 | SLAB_ATTR_RO(slab_size); | |
3909 | ||
3910 | static ssize_t align_show(struct kmem_cache *s, char *buf) | |
3911 | { | |
3912 | return sprintf(buf, "%d\n", s->align); | |
3913 | } | |
3914 | SLAB_ATTR_RO(align); | |
3915 | ||
3916 | static ssize_t object_size_show(struct kmem_cache *s, char *buf) | |
3917 | { | |
3918 | return sprintf(buf, "%d\n", s->objsize); | |
3919 | } | |
3920 | SLAB_ATTR_RO(object_size); | |
3921 | ||
3922 | static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf) | |
3923 | { | |
3924 | return sprintf(buf, "%d\n", oo_objects(s->oo)); | |
3925 | } | |
3926 | SLAB_ATTR_RO(objs_per_slab); | |
3927 | ||
3928 | static ssize_t order_store(struct kmem_cache *s, | |
3929 | const char *buf, size_t length) | |
3930 | { | |
3931 | unsigned long order; | |
3932 | int err; | |
3933 | ||
3934 | err = strict_strtoul(buf, 10, &order); | |
3935 | if (err) | |
3936 | return err; | |
3937 | ||
3938 | if (order > slub_max_order || order < slub_min_order) | |
3939 | return -EINVAL; | |
3940 | ||
3941 | calculate_sizes(s, order); | |
3942 | return length; | |
3943 | } | |
3944 | ||
3945 | static ssize_t order_show(struct kmem_cache *s, char *buf) | |
3946 | { | |
3947 | return sprintf(buf, "%d\n", oo_order(s->oo)); | |
3948 | } | |
3949 | SLAB_ATTR(order); | |
3950 | ||
3951 | static ssize_t min_partial_show(struct kmem_cache *s, char *buf) | |
3952 | { | |
3953 | return sprintf(buf, "%lu\n", s->min_partial); | |
3954 | } | |
3955 | ||
3956 | static ssize_t min_partial_store(struct kmem_cache *s, const char *buf, | |
3957 | size_t length) | |
3958 | { | |
3959 | unsigned long min; | |
3960 | int err; | |
3961 | ||
3962 | err = strict_strtoul(buf, 10, &min); | |
3963 | if (err) | |
3964 | return err; | |
3965 | ||
3966 | set_min_partial(s, min); | |
3967 | return length; | |
3968 | } | |
3969 | SLAB_ATTR(min_partial); | |
3970 | ||
3971 | static ssize_t ctor_show(struct kmem_cache *s, char *buf) | |
3972 | { | |
3973 | if (s->ctor) { | |
3974 | int n = sprint_symbol(buf, (unsigned long)s->ctor); | |
3975 | ||
3976 | return n + sprintf(buf + n, "\n"); | |
3977 | } | |
3978 | return 0; | |
3979 | } | |
3980 | SLAB_ATTR_RO(ctor); | |
3981 | ||
3982 | static ssize_t aliases_show(struct kmem_cache *s, char *buf) | |
3983 | { | |
3984 | return sprintf(buf, "%d\n", s->refcount - 1); | |
3985 | } | |
3986 | SLAB_ATTR_RO(aliases); | |
3987 | ||
3988 | static ssize_t partial_show(struct kmem_cache *s, char *buf) | |
3989 | { | |
3990 | return show_slab_objects(s, buf, SO_PARTIAL); | |
3991 | } | |
3992 | SLAB_ATTR_RO(partial); | |
3993 | ||
3994 | static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) | |
3995 | { | |
3996 | return show_slab_objects(s, buf, SO_CPU); | |
3997 | } | |
3998 | SLAB_ATTR_RO(cpu_slabs); | |
3999 | ||
4000 | static ssize_t objects_show(struct kmem_cache *s, char *buf) | |
4001 | { | |
4002 | return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS); | |
4003 | } | |
4004 | SLAB_ATTR_RO(objects); | |
4005 | ||
4006 | static ssize_t objects_partial_show(struct kmem_cache *s, char *buf) | |
4007 | { | |
4008 | return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS); | |
4009 | } | |
4010 | SLAB_ATTR_RO(objects_partial); | |
4011 | ||
4012 | static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) | |
4013 | { | |
4014 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); | |
4015 | } | |
4016 | ||
4017 | static ssize_t reclaim_account_store(struct kmem_cache *s, | |
4018 | const char *buf, size_t length) | |
4019 | { | |
4020 | s->flags &= ~SLAB_RECLAIM_ACCOUNT; | |
4021 | if (buf[0] == '1') | |
4022 | s->flags |= SLAB_RECLAIM_ACCOUNT; | |
4023 | return length; | |
4024 | } | |
4025 | SLAB_ATTR(reclaim_account); | |
4026 | ||
4027 | static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) | |
4028 | { | |
4029 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN)); | |
4030 | } | |
4031 | SLAB_ATTR_RO(hwcache_align); | |
4032 | ||
4033 | #ifdef CONFIG_ZONE_DMA | |
4034 | static ssize_t cache_dma_show(struct kmem_cache *s, char *buf) | |
4035 | { | |
4036 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA)); | |
4037 | } | |
4038 | SLAB_ATTR_RO(cache_dma); | |
4039 | #endif | |
4040 | ||
4041 | static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) | |
4042 | { | |
4043 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU)); | |
4044 | } | |
4045 | SLAB_ATTR_RO(destroy_by_rcu); | |
4046 | ||
4047 | #ifdef CONFIG_SLUB_DEBUG | |
4048 | static ssize_t slabs_show(struct kmem_cache *s, char *buf) | |
4049 | { | |
4050 | return show_slab_objects(s, buf, SO_ALL); | |
4051 | } | |
4052 | SLAB_ATTR_RO(slabs); | |
4053 | ||
4054 | static ssize_t total_objects_show(struct kmem_cache *s, char *buf) | |
4055 | { | |
4056 | return show_slab_objects(s, buf, SO_ALL|SO_TOTAL); | |
4057 | } | |
4058 | SLAB_ATTR_RO(total_objects); | |
4059 | ||
4060 | static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf) | |
4061 | { | |
4062 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE)); | |
4063 | } | |
4064 | ||
4065 | static ssize_t sanity_checks_store(struct kmem_cache *s, | |
4066 | const char *buf, size_t length) | |
4067 | { | |
4068 | s->flags &= ~SLAB_DEBUG_FREE; | |
4069 | if (buf[0] == '1') | |
4070 | s->flags |= SLAB_DEBUG_FREE; | |
4071 | return length; | |
4072 | } | |
4073 | SLAB_ATTR(sanity_checks); | |
4074 | ||
4075 | static ssize_t trace_show(struct kmem_cache *s, char *buf) | |
4076 | { | |
4077 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE)); | |
4078 | } | |
4079 | ||
4080 | static ssize_t trace_store(struct kmem_cache *s, const char *buf, | |
4081 | size_t length) | |
4082 | { | |
4083 | s->flags &= ~SLAB_TRACE; | |
4084 | if (buf[0] == '1') | |
4085 | s->flags |= SLAB_TRACE; | |
4086 | return length; | |
4087 | } | |
4088 | SLAB_ATTR(trace); | |
4089 | ||
4090 | static ssize_t red_zone_show(struct kmem_cache *s, char *buf) | |
4091 | { | |
4092 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE)); | |
4093 | } | |
4094 | ||
4095 | static ssize_t red_zone_store(struct kmem_cache *s, | |
4096 | const char *buf, size_t length) | |
4097 | { | |
4098 | if (any_slab_objects(s)) | |
4099 | return -EBUSY; | |
4100 | ||
4101 | s->flags &= ~SLAB_RED_ZONE; | |
4102 | if (buf[0] == '1') | |
4103 | s->flags |= SLAB_RED_ZONE; | |
4104 | calculate_sizes(s, -1); | |
4105 | return length; | |
4106 | } | |
4107 | SLAB_ATTR(red_zone); | |
4108 | ||
4109 | static ssize_t poison_show(struct kmem_cache *s, char *buf) | |
4110 | { | |
4111 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON)); | |
4112 | } | |
4113 | ||
4114 | static ssize_t poison_store(struct kmem_cache *s, | |
4115 | const char *buf, size_t length) | |
4116 | { | |
4117 | if (any_slab_objects(s)) | |
4118 | return -EBUSY; | |
4119 | ||
4120 | s->flags &= ~SLAB_POISON; | |
4121 | if (buf[0] == '1') | |
4122 | s->flags |= SLAB_POISON; | |
4123 | calculate_sizes(s, -1); | |
4124 | return length; | |
4125 | } | |
4126 | SLAB_ATTR(poison); | |
4127 | ||
4128 | static ssize_t store_user_show(struct kmem_cache *s, char *buf) | |
4129 | { | |
4130 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER)); | |
4131 | } | |
4132 | ||
4133 | static ssize_t store_user_store(struct kmem_cache *s, | |
4134 | const char *buf, size_t length) | |
4135 | { | |
4136 | if (any_slab_objects(s)) | |
4137 | return -EBUSY; | |
4138 | ||
4139 | s->flags &= ~SLAB_STORE_USER; | |
4140 | if (buf[0] == '1') | |
4141 | s->flags |= SLAB_STORE_USER; | |
4142 | calculate_sizes(s, -1); | |
4143 | return length; | |
4144 | } | |
4145 | SLAB_ATTR(store_user); | |
4146 | ||
4147 | static ssize_t validate_show(struct kmem_cache *s, char *buf) | |
4148 | { | |
4149 | return 0; | |
4150 | } | |
4151 | ||
4152 | static ssize_t validate_store(struct kmem_cache *s, | |
4153 | const char *buf, size_t length) | |
4154 | { | |
4155 | int ret = -EINVAL; | |
4156 | ||
4157 | if (buf[0] == '1') { | |
4158 | ret = validate_slab_cache(s); | |
4159 | if (ret >= 0) | |
4160 | ret = length; | |
4161 | } | |
4162 | return ret; | |
4163 | } | |
4164 | SLAB_ATTR(validate); | |
4165 | ||
4166 | static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) | |
4167 | { | |
4168 | if (!(s->flags & SLAB_STORE_USER)) | |
4169 | return -ENOSYS; | |
4170 | return list_locations(s, buf, TRACK_ALLOC); | |
4171 | } | |
4172 | SLAB_ATTR_RO(alloc_calls); | |
4173 | ||
4174 | static ssize_t free_calls_show(struct kmem_cache *s, char *buf) | |
4175 | { | |
4176 | if (!(s->flags & SLAB_STORE_USER)) | |
4177 | return -ENOSYS; | |
4178 | return list_locations(s, buf, TRACK_FREE); | |
4179 | } | |
4180 | SLAB_ATTR_RO(free_calls); | |
4181 | #endif /* CONFIG_SLUB_DEBUG */ | |
4182 | ||
4183 | #ifdef CONFIG_FAILSLAB | |
4184 | static ssize_t failslab_show(struct kmem_cache *s, char *buf) | |
4185 | { | |
4186 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB)); | |
4187 | } | |
4188 | ||
4189 | static ssize_t failslab_store(struct kmem_cache *s, const char *buf, | |
4190 | size_t length) | |
4191 | { | |
4192 | s->flags &= ~SLAB_FAILSLAB; | |
4193 | if (buf[0] == '1') | |
4194 | s->flags |= SLAB_FAILSLAB; | |
4195 | return length; | |
4196 | } | |
4197 | SLAB_ATTR(failslab); | |
4198 | #endif | |
4199 | ||
4200 | static ssize_t shrink_show(struct kmem_cache *s, char *buf) | |
4201 | { | |
4202 | return 0; | |
4203 | } | |
4204 | ||
4205 | static ssize_t shrink_store(struct kmem_cache *s, | |
4206 | const char *buf, size_t length) | |
4207 | { | |
4208 | if (buf[0] == '1') { | |
4209 | int rc = kmem_cache_shrink(s); | |
4210 | ||
4211 | if (rc) | |
4212 | return rc; | |
4213 | } else | |
4214 | return -EINVAL; | |
4215 | return length; | |
4216 | } | |
4217 | SLAB_ATTR(shrink); | |
4218 | ||
4219 | #ifdef CONFIG_NUMA | |
4220 | static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf) | |
4221 | { | |
4222 | return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10); | |
4223 | } | |
4224 | ||
4225 | static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s, | |
4226 | const char *buf, size_t length) | |
4227 | { | |
4228 | unsigned long ratio; | |
4229 | int err; | |
4230 | ||
4231 | err = strict_strtoul(buf, 10, &ratio); | |
4232 | if (err) | |
4233 | return err; | |
4234 | ||
4235 | if (ratio <= 100) | |
4236 | s->remote_node_defrag_ratio = ratio * 10; | |
4237 | ||
4238 | return length; | |
4239 | } | |
4240 | SLAB_ATTR(remote_node_defrag_ratio); | |
4241 | #endif | |
4242 | ||
4243 | #ifdef CONFIG_SLUB_STATS | |
4244 | static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si) | |
4245 | { | |
4246 | unsigned long sum = 0; | |
4247 | int cpu; | |
4248 | int len; | |
4249 | int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL); | |
4250 | ||
4251 | if (!data) | |
4252 | return -ENOMEM; | |
4253 | ||
4254 | for_each_online_cpu(cpu) { | |
4255 | unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si]; | |
4256 | ||
4257 | data[cpu] = x; | |
4258 | sum += x; | |
4259 | } | |
4260 | ||
4261 | len = sprintf(buf, "%lu", sum); | |
4262 | ||
4263 | #ifdef CONFIG_SMP | |
4264 | for_each_online_cpu(cpu) { | |
4265 | if (data[cpu] && len < PAGE_SIZE - 20) | |
4266 | len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]); | |
4267 | } | |
4268 | #endif | |
4269 | kfree(data); | |
4270 | return len + sprintf(buf + len, "\n"); | |
4271 | } | |
4272 | ||
4273 | static void clear_stat(struct kmem_cache *s, enum stat_item si) | |
4274 | { | |
4275 | int cpu; | |
4276 | ||
4277 | for_each_online_cpu(cpu) | |
4278 | per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0; | |
4279 | } | |
4280 | ||
4281 | #define STAT_ATTR(si, text) \ | |
4282 | static ssize_t text##_show(struct kmem_cache *s, char *buf) \ | |
4283 | { \ | |
4284 | return show_stat(s, buf, si); \ | |
4285 | } \ | |
4286 | static ssize_t text##_store(struct kmem_cache *s, \ | |
4287 | const char *buf, size_t length) \ | |
4288 | { \ | |
4289 | if (buf[0] != '0') \ | |
4290 | return -EINVAL; \ | |
4291 | clear_stat(s, si); \ | |
4292 | return length; \ | |
4293 | } \ | |
4294 | SLAB_ATTR(text); \ | |
4295 | ||
4296 | STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath); | |
4297 | STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath); | |
4298 | STAT_ATTR(FREE_FASTPATH, free_fastpath); | |
4299 | STAT_ATTR(FREE_SLOWPATH, free_slowpath); | |
4300 | STAT_ATTR(FREE_FROZEN, free_frozen); | |
4301 | STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial); | |
4302 | STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial); | |
4303 | STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial); | |
4304 | STAT_ATTR(ALLOC_SLAB, alloc_slab); | |
4305 | STAT_ATTR(ALLOC_REFILL, alloc_refill); | |
4306 | STAT_ATTR(FREE_SLAB, free_slab); | |
4307 | STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush); | |
4308 | STAT_ATTR(DEACTIVATE_FULL, deactivate_full); | |
4309 | STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty); | |
4310 | STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head); | |
4311 | STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail); | |
4312 | STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees); | |
4313 | STAT_ATTR(ORDER_FALLBACK, order_fallback); | |
4314 | #endif | |
4315 | ||
4316 | static struct attribute *slab_attrs[] = { | |
4317 | &slab_size_attr.attr, | |
4318 | &object_size_attr.attr, | |
4319 | &objs_per_slab_attr.attr, | |
4320 | &order_attr.attr, | |
4321 | &min_partial_attr.attr, | |
4322 | &objects_attr.attr, | |
4323 | &objects_partial_attr.attr, | |
4324 | &partial_attr.attr, | |
4325 | &cpu_slabs_attr.attr, | |
4326 | &ctor_attr.attr, | |
4327 | &aliases_attr.attr, | |
4328 | &align_attr.attr, | |
4329 | &hwcache_align_attr.attr, | |
4330 | &reclaim_account_attr.attr, | |
4331 | &destroy_by_rcu_attr.attr, | |
4332 | &shrink_attr.attr, | |
4333 | #ifdef CONFIG_SLUB_DEBUG | |
4334 | &total_objects_attr.attr, | |
4335 | &slabs_attr.attr, | |
4336 | &sanity_checks_attr.attr, | |
4337 | &trace_attr.attr, | |
4338 | &red_zone_attr.attr, | |
4339 | &poison_attr.attr, | |
4340 | &store_user_attr.attr, | |
4341 | &validate_attr.attr, | |
4342 | &alloc_calls_attr.attr, | |
4343 | &free_calls_attr.attr, | |
4344 | #endif | |
4345 | #ifdef CONFIG_ZONE_DMA | |
4346 | &cache_dma_attr.attr, | |
4347 | #endif | |
4348 | #ifdef CONFIG_NUMA | |
4349 | &remote_node_defrag_ratio_attr.attr, | |
4350 | #endif | |
4351 | #ifdef CONFIG_SLUB_STATS | |
4352 | &alloc_fastpath_attr.attr, | |
4353 | &alloc_slowpath_attr.attr, | |
4354 | &free_fastpath_attr.attr, | |
4355 | &free_slowpath_attr.attr, | |
4356 | &free_frozen_attr.attr, | |
4357 | &free_add_partial_attr.attr, | |
4358 | &free_remove_partial_attr.attr, | |
4359 | &alloc_from_partial_attr.attr, | |
4360 | &alloc_slab_attr.attr, | |
4361 | &alloc_refill_attr.attr, | |
4362 | &free_slab_attr.attr, | |
4363 | &cpuslab_flush_attr.attr, | |
4364 | &deactivate_full_attr.attr, | |
4365 | &deactivate_empty_attr.attr, | |
4366 | &deactivate_to_head_attr.attr, | |
4367 | &deactivate_to_tail_attr.attr, | |
4368 | &deactivate_remote_frees_attr.attr, | |
4369 | &order_fallback_attr.attr, | |
4370 | #endif | |
4371 | #ifdef CONFIG_FAILSLAB | |
4372 | &failslab_attr.attr, | |
4373 | #endif | |
4374 | ||
4375 | NULL | |
4376 | }; | |
4377 | ||
4378 | static struct attribute_group slab_attr_group = { | |
4379 | .attrs = slab_attrs, | |
4380 | }; | |
4381 | ||
4382 | static ssize_t slab_attr_show(struct kobject *kobj, | |
4383 | struct attribute *attr, | |
4384 | char *buf) | |
4385 | { | |
4386 | struct slab_attribute *attribute; | |
4387 | struct kmem_cache *s; | |
4388 | int err; | |
4389 | ||
4390 | attribute = to_slab_attr(attr); | |
4391 | s = to_slab(kobj); | |
4392 | ||
4393 | if (!attribute->show) | |
4394 | return -EIO; | |
4395 | ||
4396 | err = attribute->show(s, buf); | |
4397 | ||
4398 | return err; | |
4399 | } | |
4400 | ||
4401 | static ssize_t slab_attr_store(struct kobject *kobj, | |
4402 | struct attribute *attr, | |
4403 | const char *buf, size_t len) | |
4404 | { | |
4405 | struct slab_attribute *attribute; | |
4406 | struct kmem_cache *s; | |
4407 | int err; | |
4408 | ||
4409 | attribute = to_slab_attr(attr); | |
4410 | s = to_slab(kobj); | |
4411 | ||
4412 | if (!attribute->store) | |
4413 | return -EIO; | |
4414 | ||
4415 | err = attribute->store(s, buf, len); | |
4416 | ||
4417 | return err; | |
4418 | } | |
4419 | ||
4420 | static void kmem_cache_release(struct kobject *kobj) | |
4421 | { | |
4422 | struct kmem_cache *s = to_slab(kobj); | |
4423 | ||
4424 | kfree(s->name); | |
4425 | kfree(s); | |
4426 | } | |
4427 | ||
4428 | static const struct sysfs_ops slab_sysfs_ops = { | |
4429 | .show = slab_attr_show, | |
4430 | .store = slab_attr_store, | |
4431 | }; | |
4432 | ||
4433 | static struct kobj_type slab_ktype = { | |
4434 | .sysfs_ops = &slab_sysfs_ops, | |
4435 | .release = kmem_cache_release | |
4436 | }; | |
4437 | ||
4438 | static int uevent_filter(struct kset *kset, struct kobject *kobj) | |
4439 | { | |
4440 | struct kobj_type *ktype = get_ktype(kobj); | |
4441 | ||
4442 | if (ktype == &slab_ktype) | |
4443 | return 1; | |
4444 | return 0; | |
4445 | } | |
4446 | ||
4447 | static const struct kset_uevent_ops slab_uevent_ops = { | |
4448 | .filter = uevent_filter, | |
4449 | }; | |
4450 | ||
4451 | static struct kset *slab_kset; | |
4452 | ||
4453 | #define ID_STR_LENGTH 64 | |
4454 | ||
4455 | /* Create a unique string id for a slab cache: | |
4456 | * | |
4457 | * Format :[flags-]size | |
4458 | */ | |
4459 | static char *create_unique_id(struct kmem_cache *s) | |
4460 | { | |
4461 | char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); | |
4462 | char *p = name; | |
4463 | ||
4464 | BUG_ON(!name); | |
4465 | ||
4466 | *p++ = ':'; | |
4467 | /* | |
4468 | * First flags affecting slabcache operations. We will only | |
4469 | * get here for aliasable slabs so we do not need to support | |
4470 | * too many flags. The flags here must cover all flags that | |
4471 | * are matched during merging to guarantee that the id is | |
4472 | * unique. | |
4473 | */ | |
4474 | if (s->flags & SLAB_CACHE_DMA) | |
4475 | *p++ = 'd'; | |
4476 | if (s->flags & SLAB_RECLAIM_ACCOUNT) | |
4477 | *p++ = 'a'; | |
4478 | if (s->flags & SLAB_DEBUG_FREE) | |
4479 | *p++ = 'F'; | |
4480 | if (!(s->flags & SLAB_NOTRACK)) | |
4481 | *p++ = 't'; | |
4482 | if (p != name + 1) | |
4483 | *p++ = '-'; | |
4484 | p += sprintf(p, "%07d", s->size); | |
4485 | BUG_ON(p > name + ID_STR_LENGTH - 1); | |
4486 | return name; | |
4487 | } | |
4488 | ||
4489 | static int sysfs_slab_add(struct kmem_cache *s) | |
4490 | { | |
4491 | int err; | |
4492 | const char *name; | |
4493 | int unmergeable; | |
4494 | ||
4495 | if (slab_state < SYSFS) | |
4496 | /* Defer until later */ | |
4497 | return 0; | |
4498 | ||
4499 | unmergeable = slab_unmergeable(s); | |
4500 | if (unmergeable) { | |
4501 | /* | |
4502 | * Slabcache can never be merged so we can use the name proper. | |
4503 | * This is typically the case for debug situations. In that | |
4504 | * case we can catch duplicate names easily. | |
4505 | */ | |
4506 | sysfs_remove_link(&slab_kset->kobj, s->name); | |
4507 | name = s->name; | |
4508 | } else { | |
4509 | /* | |
4510 | * Create a unique name for the slab as a target | |
4511 | * for the symlinks. | |
4512 | */ | |
4513 | name = create_unique_id(s); | |
4514 | } | |
4515 | ||
4516 | s->kobj.kset = slab_kset; | |
4517 | err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name); | |
4518 | if (err) { | |
4519 | kobject_put(&s->kobj); | |
4520 | return err; | |
4521 | } | |
4522 | ||
4523 | err = sysfs_create_group(&s->kobj, &slab_attr_group); | |
4524 | if (err) { | |
4525 | kobject_del(&s->kobj); | |
4526 | kobject_put(&s->kobj); | |
4527 | return err; | |
4528 | } | |
4529 | kobject_uevent(&s->kobj, KOBJ_ADD); | |
4530 | if (!unmergeable) { | |
4531 | /* Setup first alias */ | |
4532 | sysfs_slab_alias(s, s->name); | |
4533 | kfree(name); | |
4534 | } | |
4535 | return 0; | |
4536 | } | |
4537 | ||
4538 | static void sysfs_slab_remove(struct kmem_cache *s) | |
4539 | { | |
4540 | if (slab_state < SYSFS) | |
4541 | /* | |
4542 | * Sysfs has not been setup yet so no need to remove the | |
4543 | * cache from sysfs. | |
4544 | */ | |
4545 | return; | |
4546 | ||
4547 | kobject_uevent(&s->kobj, KOBJ_REMOVE); | |
4548 | kobject_del(&s->kobj); | |
4549 | kobject_put(&s->kobj); | |
4550 | } | |
4551 | ||
4552 | /* | |
4553 | * Need to buffer aliases during bootup until sysfs becomes | |
4554 | * available lest we lose that information. | |
4555 | */ | |
4556 | struct saved_alias { | |
4557 | struct kmem_cache *s; | |
4558 | const char *name; | |
4559 | struct saved_alias *next; | |
4560 | }; | |
4561 | ||
4562 | static struct saved_alias *alias_list; | |
4563 | ||
4564 | static int sysfs_slab_alias(struct kmem_cache *s, const char *name) | |
4565 | { | |
4566 | struct saved_alias *al; | |
4567 | ||
4568 | if (slab_state == SYSFS) { | |
4569 | /* | |
4570 | * If we have a leftover link then remove it. | |
4571 | */ | |
4572 | sysfs_remove_link(&slab_kset->kobj, name); | |
4573 | return sysfs_create_link(&slab_kset->kobj, &s->kobj, name); | |
4574 | } | |
4575 | ||
4576 | al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); | |
4577 | if (!al) | |
4578 | return -ENOMEM; | |
4579 | ||
4580 | al->s = s; | |
4581 | al->name = name; | |
4582 | al->next = alias_list; | |
4583 | alias_list = al; | |
4584 | return 0; | |
4585 | } | |
4586 | ||
4587 | static int __init slab_sysfs_init(void) | |
4588 | { | |
4589 | struct kmem_cache *s; | |
4590 | int err; | |
4591 | ||
4592 | down_write(&slub_lock); | |
4593 | ||
4594 | slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj); | |
4595 | if (!slab_kset) { | |
4596 | up_write(&slub_lock); | |
4597 | printk(KERN_ERR "Cannot register slab subsystem.\n"); | |
4598 | return -ENOSYS; | |
4599 | } | |
4600 | ||
4601 | slab_state = SYSFS; | |
4602 | ||
4603 | list_for_each_entry(s, &slab_caches, list) { | |
4604 | err = sysfs_slab_add(s); | |
4605 | if (err) | |
4606 | printk(KERN_ERR "SLUB: Unable to add boot slab %s" | |
4607 | " to sysfs\n", s->name); | |
4608 | } | |
4609 | ||
4610 | while (alias_list) { | |
4611 | struct saved_alias *al = alias_list; | |
4612 | ||
4613 | alias_list = alias_list->next; | |
4614 | err = sysfs_slab_alias(al->s, al->name); | |
4615 | if (err) | |
4616 | printk(KERN_ERR "SLUB: Unable to add boot slab alias" | |
4617 | " %s to sysfs\n", s->name); | |
4618 | kfree(al); | |
4619 | } | |
4620 | ||
4621 | up_write(&slub_lock); | |
4622 | resiliency_test(); | |
4623 | return 0; | |
4624 | } | |
4625 | ||
4626 | __initcall(slab_sysfs_init); | |
4627 | #endif /* CONFIG_SYSFS */ | |
4628 | ||
4629 | /* | |
4630 | * The /proc/slabinfo ABI | |
4631 | */ | |
4632 | #ifdef CONFIG_SLABINFO | |
4633 | static void print_slabinfo_header(struct seq_file *m) | |
4634 | { | |
4635 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
4636 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " | |
4637 | "<objperslab> <pagesperslab>"); | |
4638 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); | |
4639 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
4640 | seq_putc(m, '\n'); | |
4641 | } | |
4642 | ||
4643 | static void *s_start(struct seq_file *m, loff_t *pos) | |
4644 | { | |
4645 | loff_t n = *pos; | |
4646 | ||
4647 | down_read(&slub_lock); | |
4648 | if (!n) | |
4649 | print_slabinfo_header(m); | |
4650 | ||
4651 | return seq_list_start(&slab_caches, *pos); | |
4652 | } | |
4653 | ||
4654 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
4655 | { | |
4656 | return seq_list_next(p, &slab_caches, pos); | |
4657 | } | |
4658 | ||
4659 | static void s_stop(struct seq_file *m, void *p) | |
4660 | { | |
4661 | up_read(&slub_lock); | |
4662 | } | |
4663 | ||
4664 | static int s_show(struct seq_file *m, void *p) | |
4665 | { | |
4666 | unsigned long nr_partials = 0; | |
4667 | unsigned long nr_slabs = 0; | |
4668 | unsigned long nr_inuse = 0; | |
4669 | unsigned long nr_objs = 0; | |
4670 | unsigned long nr_free = 0; | |
4671 | struct kmem_cache *s; | |
4672 | int node; | |
4673 | ||
4674 | s = list_entry(p, struct kmem_cache, list); | |
4675 | ||
4676 | for_each_online_node(node) { | |
4677 | struct kmem_cache_node *n = get_node(s, node); | |
4678 | ||
4679 | if (!n) | |
4680 | continue; | |
4681 | ||
4682 | nr_partials += n->nr_partial; | |
4683 | nr_slabs += atomic_long_read(&n->nr_slabs); | |
4684 | nr_objs += atomic_long_read(&n->total_objects); | |
4685 | nr_free += count_partial(n, count_free); | |
4686 | } | |
4687 | ||
4688 | nr_inuse = nr_objs - nr_free; | |
4689 | ||
4690 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse, | |
4691 | nr_objs, s->size, oo_objects(s->oo), | |
4692 | (1 << oo_order(s->oo))); | |
4693 | seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0); | |
4694 | seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs, | |
4695 | 0UL); | |
4696 | seq_putc(m, '\n'); | |
4697 | return 0; | |
4698 | } | |
4699 | ||
4700 | static const struct seq_operations slabinfo_op = { | |
4701 | .start = s_start, | |
4702 | .next = s_next, | |
4703 | .stop = s_stop, | |
4704 | .show = s_show, | |
4705 | }; | |
4706 | ||
4707 | static int slabinfo_open(struct inode *inode, struct file *file) | |
4708 | { | |
4709 | return seq_open(file, &slabinfo_op); | |
4710 | } | |
4711 | ||
4712 | static const struct file_operations proc_slabinfo_operations = { | |
4713 | .open = slabinfo_open, | |
4714 | .read = seq_read, | |
4715 | .llseek = seq_lseek, | |
4716 | .release = seq_release, | |
4717 | }; | |
4718 | ||
4719 | static int __init slab_proc_init(void) | |
4720 | { | |
4721 | proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations); | |
4722 | return 0; | |
4723 | } | |
4724 | module_init(slab_proc_init); | |
4725 | #endif /* CONFIG_SLABINFO */ |