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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 | #define __SYSFS_ADD_DEFERRED 0x40000000UL /* Not yet visible via sysfs */ |
172 | |
173 | static int kmem_size = sizeof(struct kmem_cache); |
174 | |
175 | #ifdef CONFIG_SMP |
176 | static struct notifier_block slab_notifier; |
177 | #endif |
178 | |
179 | static enum { |
180 | DOWN, /* No slab functionality available */ |
181 | PARTIAL, /* kmem_cache_open() works but kmalloc does not */ |
182 | UP, /* Everything works but does not show up in sysfs */ |
183 | SYSFS /* Sysfs up */ |
184 | } slab_state = DOWN; |
185 | |
186 | /* A list of all slab caches on the system */ |
187 | static DECLARE_RWSEM(slub_lock); |
188 | static LIST_HEAD(slab_caches); |
189 | |
190 | /* |
191 | * Tracking user of a slab. |
192 | */ |
193 | struct track { |
194 | unsigned long addr; /* Called from address */ |
195 | int cpu; /* Was running on cpu */ |
196 | int pid; /* Pid context */ |
197 | unsigned long when; /* When did the operation occur */ |
198 | }; |
199 | |
200 | enum track_item { TRACK_ALLOC, TRACK_FREE }; |
201 | |
202 | #ifdef CONFIG_SLUB_DEBUG |
203 | static int sysfs_slab_add(struct kmem_cache *); |
204 | static int sysfs_slab_alias(struct kmem_cache *, const char *); |
205 | static void sysfs_slab_remove(struct kmem_cache *); |
206 | |
207 | #else |
208 | static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; } |
209 | static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) |
210 | { return 0; } |
211 | static inline void sysfs_slab_remove(struct kmem_cache *s) |
212 | { |
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 | #ifdef CONFIG_NUMA |
237 | return s->node[node]; |
238 | #else |
239 | return &s->local_node; |
240 | #endif |
241 | } |
242 | |
243 | /* Verify that a pointer has an address that is valid within a slab page */ |
244 | static inline int check_valid_pointer(struct kmem_cache *s, |
245 | struct page *page, const void *object) |
246 | { |
247 | void *base; |
248 | |
249 | if (!object) |
250 | return 1; |
251 | |
252 | base = page_address(page); |
253 | if (object < base || object >= base + page->objects * s->size || |
254 | (object - base) % s->size) { |
255 | return 0; |
256 | } |
257 | |
258 | return 1; |
259 | } |
260 | |
261 | static inline void *get_freepointer(struct kmem_cache *s, void *object) |
262 | { |
263 | return *(void **)(object + s->offset); |
264 | } |
265 | |
266 | static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) |
267 | { |
268 | *(void **)(object + s->offset) = fp; |
269 | } |
270 | |
271 | /* Loop over all objects in a slab */ |
272 | #define for_each_object(__p, __s, __addr, __objects) \ |
273 | for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\ |
274 | __p += (__s)->size) |
275 | |
276 | /* Scan freelist */ |
277 | #define for_each_free_object(__p, __s, __free) \ |
278 | for (__p = (__free); __p; __p = get_freepointer((__s), __p)) |
279 | |
280 | /* Determine object index from a given position */ |
281 | static inline int slab_index(void *p, struct kmem_cache *s, void *addr) |
282 | { |
283 | return (p - addr) / s->size; |
284 | } |
285 | |
286 | static inline struct kmem_cache_order_objects oo_make(int order, |
287 | unsigned long size) |
288 | { |
289 | struct kmem_cache_order_objects x = { |
290 | (order << OO_SHIFT) + (PAGE_SIZE << order) / size |
291 | }; |
292 | |
293 | return x; |
294 | } |
295 | |
296 | static inline int oo_order(struct kmem_cache_order_objects x) |
297 | { |
298 | return x.x >> OO_SHIFT; |
299 | } |
300 | |
301 | static inline int oo_objects(struct kmem_cache_order_objects x) |
302 | { |
303 | return x.x & OO_MASK; |
304 | } |
305 | |
306 | #ifdef CONFIG_SLUB_DEBUG |
307 | /* |
308 | * Debug settings: |
309 | */ |
310 | #ifdef CONFIG_SLUB_DEBUG_ON |
311 | static int slub_debug = DEBUG_DEFAULT_FLAGS; |
312 | #else |
313 | static int slub_debug; |
314 | #endif |
315 | |
316 | static char *slub_debug_slabs; |
317 | static int disable_higher_order_debug; |
318 | |
319 | /* |
320 | * Object debugging |
321 | */ |
322 | static void print_section(char *text, u8 *addr, unsigned int length) |
323 | { |
324 | int i, offset; |
325 | int newline = 1; |
326 | char ascii[17]; |
327 | |
328 | ascii[16] = 0; |
329 | |
330 | for (i = 0; i < length; i++) { |
331 | if (newline) { |
332 | printk(KERN_ERR "%8s 0x%p: ", text, addr + i); |
333 | newline = 0; |
334 | } |
335 | printk(KERN_CONT " %02x", addr[i]); |
336 | offset = i % 16; |
337 | ascii[offset] = isgraph(addr[i]) ? addr[i] : '.'; |
338 | if (offset == 15) { |
339 | printk(KERN_CONT " %s\n", ascii); |
340 | newline = 1; |
341 | } |
342 | } |
343 | if (!newline) { |
344 | i %= 16; |
345 | while (i < 16) { |
346 | printk(KERN_CONT " "); |
347 | ascii[i] = ' '; |
348 | i++; |
349 | } |
350 | printk(KERN_CONT " %s\n", ascii); |
351 | } |
352 | } |
353 | |
354 | static struct track *get_track(struct kmem_cache *s, void *object, |
355 | enum track_item alloc) |
356 | { |
357 | struct track *p; |
358 | |
359 | if (s->offset) |
360 | p = object + s->offset + sizeof(void *); |
361 | else |
362 | p = object + s->inuse; |
363 | |
364 | return p + alloc; |
365 | } |
366 | |
367 | static void set_track(struct kmem_cache *s, void *object, |
368 | enum track_item alloc, unsigned long addr) |
369 | { |
370 | struct track *p = get_track(s, object, alloc); |
371 | |
372 | if (addr) { |
373 | p->addr = addr; |
374 | p->cpu = smp_processor_id(); |
375 | p->pid = current->pid; |
376 | p->when = jiffies; |
377 | } else |
378 | memset(p, 0, sizeof(struct track)); |
379 | } |
380 | |
381 | static void init_tracking(struct kmem_cache *s, void *object) |
382 | { |
383 | if (!(s->flags & SLAB_STORE_USER)) |
384 | return; |
385 | |
386 | set_track(s, object, TRACK_FREE, 0UL); |
387 | set_track(s, object, TRACK_ALLOC, 0UL); |
388 | } |
389 | |
390 | static void print_track(const char *s, struct track *t) |
391 | { |
392 | if (!t->addr) |
393 | return; |
394 | |
395 | printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n", |
396 | s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid); |
397 | } |
398 | |
399 | static void print_tracking(struct kmem_cache *s, void *object) |
400 | { |
401 | if (!(s->flags & SLAB_STORE_USER)) |
402 | return; |
403 | |
404 | print_track("Allocated", get_track(s, object, TRACK_ALLOC)); |
405 | print_track("Freed", get_track(s, object, TRACK_FREE)); |
406 | } |
407 | |
408 | static void print_page_info(struct page *page) |
409 | { |
410 | printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n", |
411 | page, page->objects, page->inuse, page->freelist, page->flags); |
412 | |
413 | } |
414 | |
415 | static void slab_bug(struct kmem_cache *s, char *fmt, ...) |
416 | { |
417 | va_list args; |
418 | char buf[100]; |
419 | |
420 | va_start(args, fmt); |
421 | vsnprintf(buf, sizeof(buf), fmt, args); |
422 | va_end(args); |
423 | printk(KERN_ERR "========================================" |
424 | "=====================================\n"); |
425 | printk(KERN_ERR "BUG %s: %s\n", s->name, buf); |
426 | printk(KERN_ERR "----------------------------------------" |
427 | "-------------------------------------\n\n"); |
428 | } |
429 | |
430 | static void slab_fix(struct kmem_cache *s, char *fmt, ...) |
431 | { |
432 | va_list args; |
433 | char buf[100]; |
434 | |
435 | va_start(args, fmt); |
436 | vsnprintf(buf, sizeof(buf), fmt, args); |
437 | va_end(args); |
438 | printk(KERN_ERR "FIX %s: %s\n", s->name, buf); |
439 | } |
440 | |
441 | static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p) |
442 | { |
443 | unsigned int off; /* Offset of last byte */ |
444 | u8 *addr = page_address(page); |
445 | |
446 | print_tracking(s, p); |
447 | |
448 | print_page_info(page); |
449 | |
450 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n", |
451 | p, p - addr, get_freepointer(s, p)); |
452 | |
453 | if (p > addr + 16) |
454 | print_section("Bytes b4", p - 16, 16); |
455 | |
456 | print_section("Object", p, min_t(unsigned long, s->objsize, PAGE_SIZE)); |
457 | |
458 | if (s->flags & SLAB_RED_ZONE) |
459 | print_section("Redzone", p + s->objsize, |
460 | s->inuse - s->objsize); |
461 | |
462 | if (s->offset) |
463 | off = s->offset + sizeof(void *); |
464 | else |
465 | off = s->inuse; |
466 | |
467 | if (s->flags & SLAB_STORE_USER) |
468 | off += 2 * sizeof(struct track); |
469 | |
470 | if (off != s->size) |
471 | /* Beginning of the filler is the free pointer */ |
472 | print_section("Padding", p + off, s->size - off); |
473 | |
474 | dump_stack(); |
475 | } |
476 | |
477 | static void object_err(struct kmem_cache *s, struct page *page, |
478 | u8 *object, char *reason) |
479 | { |
480 | slab_bug(s, "%s", reason); |
481 | print_trailer(s, page, object); |
482 | } |
483 | |
484 | static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...) |
485 | { |
486 | va_list args; |
487 | char buf[100]; |
488 | |
489 | va_start(args, fmt); |
490 | vsnprintf(buf, sizeof(buf), fmt, args); |
491 | va_end(args); |
492 | slab_bug(s, "%s", buf); |
493 | print_page_info(page); |
494 | dump_stack(); |
495 | } |
496 | |
497 | static void init_object(struct kmem_cache *s, void *object, int active) |
498 | { |
499 | u8 *p = object; |
500 | |
501 | if (s->flags & __OBJECT_POISON) { |
502 | memset(p, POISON_FREE, s->objsize - 1); |
503 | p[s->objsize - 1] = POISON_END; |
504 | } |
505 | |
506 | if (s->flags & SLAB_RED_ZONE) |
507 | memset(p + s->objsize, |
508 | active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE, |
509 | s->inuse - s->objsize); |
510 | } |
511 | |
512 | static u8 *check_bytes(u8 *start, unsigned int value, unsigned int bytes) |
513 | { |
514 | while (bytes) { |
515 | if (*start != (u8)value) |
516 | return start; |
517 | start++; |
518 | bytes--; |
519 | } |
520 | return NULL; |
521 | } |
522 | |
523 | static void restore_bytes(struct kmem_cache *s, char *message, u8 data, |
524 | void *from, void *to) |
525 | { |
526 | slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data); |
527 | memset(from, data, to - from); |
528 | } |
529 | |
530 | static int check_bytes_and_report(struct kmem_cache *s, struct page *page, |
531 | u8 *object, char *what, |
532 | u8 *start, unsigned int value, unsigned int bytes) |
533 | { |
534 | u8 *fault; |
535 | u8 *end; |
536 | |
537 | fault = check_bytes(start, value, bytes); |
538 | if (!fault) |
539 | return 1; |
540 | |
541 | end = start + bytes; |
542 | while (end > fault && end[-1] == value) |
543 | end--; |
544 | |
545 | slab_bug(s, "%s overwritten", what); |
546 | printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n", |
547 | fault, end - 1, fault[0], value); |
548 | print_trailer(s, page, object); |
549 | |
550 | restore_bytes(s, what, value, fault, end); |
551 | return 0; |
552 | } |
553 | |
554 | /* |
555 | * Object layout: |
556 | * |
557 | * object address |
558 | * Bytes of the object to be managed. |
559 | * If the freepointer may overlay the object then the free |
560 | * pointer is the first word of the object. |
561 | * |
562 | * Poisoning uses 0x6b (POISON_FREE) and the last byte is |
563 | * 0xa5 (POISON_END) |
564 | * |
565 | * object + s->objsize |
566 | * Padding to reach word boundary. This is also used for Redzoning. |
567 | * Padding is extended by another word if Redzoning is enabled and |
568 | * objsize == inuse. |
569 | * |
570 | * We fill with 0xbb (RED_INACTIVE) for inactive objects and with |
571 | * 0xcc (RED_ACTIVE) for objects in use. |
572 | * |
573 | * object + s->inuse |
574 | * Meta data starts here. |
575 | * |
576 | * A. Free pointer (if we cannot overwrite object on free) |
577 | * B. Tracking data for SLAB_STORE_USER |
578 | * C. Padding to reach required alignment boundary or at mininum |
579 | * one word if debugging is on to be able to detect writes |
580 | * before the word boundary. |
581 | * |
582 | * Padding is done using 0x5a (POISON_INUSE) |
583 | * |
584 | * object + s->size |
585 | * Nothing is used beyond s->size. |
586 | * |
587 | * If slabcaches are merged then the objsize and inuse boundaries are mostly |
588 | * ignored. And therefore no slab options that rely on these boundaries |
589 | * may be used with merged slabcaches. |
590 | */ |
591 | |
592 | static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p) |
593 | { |
594 | unsigned long off = s->inuse; /* The end of info */ |
595 | |
596 | if (s->offset) |
597 | /* Freepointer is placed after the object. */ |
598 | off += sizeof(void *); |
599 | |
600 | if (s->flags & SLAB_STORE_USER) |
601 | /* We also have user information there */ |
602 | off += 2 * sizeof(struct track); |
603 | |
604 | if (s->size == off) |
605 | return 1; |
606 | |
607 | return check_bytes_and_report(s, page, p, "Object padding", |
608 | p + off, POISON_INUSE, s->size - off); |
609 | } |
610 | |
611 | /* Check the pad bytes at the end of a slab page */ |
612 | static int slab_pad_check(struct kmem_cache *s, struct page *page) |
613 | { |
614 | u8 *start; |
615 | u8 *fault; |
616 | u8 *end; |
617 | int length; |
618 | int remainder; |
619 | |
620 | if (!(s->flags & SLAB_POISON)) |
621 | return 1; |
622 | |
623 | start = page_address(page); |
624 | length = (PAGE_SIZE << compound_order(page)); |
625 | end = start + length; |
626 | remainder = length % s->size; |
627 | if (!remainder) |
628 | return 1; |
629 | |
630 | fault = check_bytes(end - remainder, POISON_INUSE, remainder); |
631 | if (!fault) |
632 | return 1; |
633 | while (end > fault && end[-1] == POISON_INUSE) |
634 | end--; |
635 | |
636 | slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1); |
637 | print_section("Padding", end - remainder, remainder); |
638 | |
639 | restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end); |
640 | return 0; |
641 | } |
642 | |
643 | static int check_object(struct kmem_cache *s, struct page *page, |
644 | void *object, int active) |
645 | { |
646 | u8 *p = object; |
647 | u8 *endobject = object + s->objsize; |
648 | |
649 | if (s->flags & SLAB_RED_ZONE) { |
650 | unsigned int red = |
651 | active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE; |
652 | |
653 | if (!check_bytes_and_report(s, page, object, "Redzone", |
654 | endobject, red, s->inuse - s->objsize)) |
655 | return 0; |
656 | } else { |
657 | if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) { |
658 | check_bytes_and_report(s, page, p, "Alignment padding", |
659 | endobject, POISON_INUSE, s->inuse - s->objsize); |
660 | } |
661 | } |
662 | |
663 | if (s->flags & SLAB_POISON) { |
664 | if (!active && (s->flags & __OBJECT_POISON) && |
665 | (!check_bytes_and_report(s, page, p, "Poison", p, |
666 | POISON_FREE, s->objsize - 1) || |
667 | !check_bytes_and_report(s, page, p, "Poison", |
668 | p + s->objsize - 1, POISON_END, 1))) |
669 | return 0; |
670 | /* |
671 | * check_pad_bytes cleans up on its own. |
672 | */ |
673 | check_pad_bytes(s, page, p); |
674 | } |
675 | |
676 | if (!s->offset && active) |
677 | /* |
678 | * Object and freepointer overlap. Cannot check |
679 | * freepointer while object is allocated. |
680 | */ |
681 | return 1; |
682 | |
683 | /* Check free pointer validity */ |
684 | if (!check_valid_pointer(s, page, get_freepointer(s, p))) { |
685 | object_err(s, page, p, "Freepointer corrupt"); |
686 | /* |
687 | * No choice but to zap it and thus lose the remainder |
688 | * of the free objects in this slab. May cause |
689 | * another error because the object count is now wrong. |
690 | */ |
691 | set_freepointer(s, p, NULL); |
692 | return 0; |
693 | } |
694 | return 1; |
695 | } |
696 | |
697 | static int check_slab(struct kmem_cache *s, struct page *page) |
698 | { |
699 | int maxobj; |
700 | |
701 | VM_BUG_ON(!irqs_disabled()); |
702 | |
703 | if (!PageSlab(page)) { |
704 | slab_err(s, page, "Not a valid slab page"); |
705 | return 0; |
706 | } |
707 | |
708 | maxobj = (PAGE_SIZE << compound_order(page)) / s->size; |
709 | if (page->objects > maxobj) { |
710 | slab_err(s, page, "objects %u > max %u", |
711 | s->name, page->objects, maxobj); |
712 | return 0; |
713 | } |
714 | if (page->inuse > page->objects) { |
715 | slab_err(s, page, "inuse %u > max %u", |
716 | s->name, page->inuse, page->objects); |
717 | return 0; |
718 | } |
719 | /* Slab_pad_check fixes things up after itself */ |
720 | slab_pad_check(s, page); |
721 | return 1; |
722 | } |
723 | |
724 | /* |
725 | * Determine if a certain object on a page is on the freelist. Must hold the |
726 | * slab lock to guarantee that the chains are in a consistent state. |
727 | */ |
728 | static int on_freelist(struct kmem_cache *s, struct page *page, void *search) |
729 | { |
730 | int nr = 0; |
731 | void *fp = page->freelist; |
732 | void *object = NULL; |
733 | unsigned long max_objects; |
734 | |
735 | while (fp && nr <= page->objects) { |
736 | if (fp == search) |
737 | return 1; |
738 | if (!check_valid_pointer(s, page, fp)) { |
739 | if (object) { |
740 | object_err(s, page, object, |
741 | "Freechain corrupt"); |
742 | set_freepointer(s, object, NULL); |
743 | break; |
744 | } else { |
745 | slab_err(s, page, "Freepointer corrupt"); |
746 | page->freelist = NULL; |
747 | page->inuse = page->objects; |
748 | slab_fix(s, "Freelist cleared"); |
749 | return 0; |
750 | } |
751 | break; |
752 | } |
753 | object = fp; |
754 | fp = get_freepointer(s, object); |
755 | nr++; |
756 | } |
757 | |
758 | max_objects = (PAGE_SIZE << compound_order(page)) / s->size; |
759 | if (max_objects > MAX_OBJS_PER_PAGE) |
760 | max_objects = MAX_OBJS_PER_PAGE; |
761 | |
762 | if (page->objects != max_objects) { |
763 | slab_err(s, page, "Wrong number of objects. Found %d but " |
764 | "should be %d", page->objects, max_objects); |
765 | page->objects = max_objects; |
766 | slab_fix(s, "Number of objects adjusted."); |
767 | } |
768 | if (page->inuse != page->objects - nr) { |
769 | slab_err(s, page, "Wrong object count. Counter is %d but " |
770 | "counted were %d", page->inuse, page->objects - nr); |
771 | page->inuse = page->objects - nr; |
772 | slab_fix(s, "Object count adjusted."); |
773 | } |
774 | return search == NULL; |
775 | } |
776 | |
777 | static void trace(struct kmem_cache *s, struct page *page, void *object, |
778 | int alloc) |
779 | { |
780 | if (s->flags & SLAB_TRACE) { |
781 | printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n", |
782 | s->name, |
783 | alloc ? "alloc" : "free", |
784 | object, page->inuse, |
785 | page->freelist); |
786 | |
787 | if (!alloc) |
788 | print_section("Object", (void *)object, s->objsize); |
789 | |
790 | dump_stack(); |
791 | } |
792 | } |
793 | |
794 | /* |
795 | * Tracking of fully allocated slabs for debugging purposes. |
796 | */ |
797 | static void add_full(struct kmem_cache_node *n, struct page *page) |
798 | { |
799 | spin_lock(&n->list_lock); |
800 | list_add(&page->lru, &n->full); |
801 | spin_unlock(&n->list_lock); |
802 | } |
803 | |
804 | static void remove_full(struct kmem_cache *s, struct page *page) |
805 | { |
806 | struct kmem_cache_node *n; |
807 | |
808 | if (!(s->flags & SLAB_STORE_USER)) |
809 | return; |
810 | |
811 | n = get_node(s, page_to_nid(page)); |
812 | |
813 | spin_lock(&n->list_lock); |
814 | list_del(&page->lru); |
815 | spin_unlock(&n->list_lock); |
816 | } |
817 | |
818 | /* Tracking of the number of slabs for debugging purposes */ |
819 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) |
820 | { |
821 | struct kmem_cache_node *n = get_node(s, node); |
822 | |
823 | return atomic_long_read(&n->nr_slabs); |
824 | } |
825 | |
826 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) |
827 | { |
828 | return atomic_long_read(&n->nr_slabs); |
829 | } |
830 | |
831 | static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects) |
832 | { |
833 | struct kmem_cache_node *n = get_node(s, node); |
834 | |
835 | /* |
836 | * May be called early in order to allocate a slab for the |
837 | * kmem_cache_node structure. Solve the chicken-egg |
838 | * dilemma by deferring the increment of the count during |
839 | * bootstrap (see early_kmem_cache_node_alloc). |
840 | */ |
841 | if (!NUMA_BUILD || n) { |
842 | atomic_long_inc(&n->nr_slabs); |
843 | atomic_long_add(objects, &n->total_objects); |
844 | } |
845 | } |
846 | static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects) |
847 | { |
848 | struct kmem_cache_node *n = get_node(s, node); |
849 | |
850 | atomic_long_dec(&n->nr_slabs); |
851 | atomic_long_sub(objects, &n->total_objects); |
852 | } |
853 | |
854 | /* Object debug checks for alloc/free paths */ |
855 | static void setup_object_debug(struct kmem_cache *s, struct page *page, |
856 | void *object) |
857 | { |
858 | if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))) |
859 | return; |
860 | |
861 | init_object(s, object, 0); |
862 | init_tracking(s, object); |
863 | } |
864 | |
865 | static int alloc_debug_processing(struct kmem_cache *s, struct page *page, |
866 | void *object, unsigned long addr) |
867 | { |
868 | if (!check_slab(s, page)) |
869 | goto bad; |
870 | |
871 | if (!on_freelist(s, page, object)) { |
872 | object_err(s, page, object, "Object already allocated"); |
873 | goto bad; |
874 | } |
875 | |
876 | if (!check_valid_pointer(s, page, object)) { |
877 | object_err(s, page, object, "Freelist Pointer check fails"); |
878 | goto bad; |
879 | } |
880 | |
881 | if (!check_object(s, page, object, 0)) |
882 | goto bad; |
883 | |
884 | /* Success perform special debug activities for allocs */ |
885 | if (s->flags & SLAB_STORE_USER) |
886 | set_track(s, object, TRACK_ALLOC, addr); |
887 | trace(s, page, object, 1); |
888 | init_object(s, object, 1); |
889 | return 1; |
890 | |
891 | bad: |
892 | if (PageSlab(page)) { |
893 | /* |
894 | * If this is a slab page then lets do the best we can |
895 | * to avoid issues in the future. Marking all objects |
896 | * as used avoids touching the remaining objects. |
897 | */ |
898 | slab_fix(s, "Marking all objects used"); |
899 | page->inuse = page->objects; |
900 | page->freelist = NULL; |
901 | } |
902 | return 0; |
903 | } |
904 | |
905 | static int free_debug_processing(struct kmem_cache *s, struct page *page, |
906 | void *object, unsigned long addr) |
907 | { |
908 | if (!check_slab(s, page)) |
909 | goto fail; |
910 | |
911 | if (!check_valid_pointer(s, page, object)) { |
912 | slab_err(s, page, "Invalid object pointer 0x%p", object); |
913 | goto fail; |
914 | } |
915 | |
916 | if (on_freelist(s, page, object)) { |
917 | object_err(s, page, object, "Object already free"); |
918 | goto fail; |
919 | } |
920 | |
921 | if (!check_object(s, page, object, 1)) |
922 | return 0; |
923 | |
924 | if (unlikely(s != page->slab)) { |
925 | if (!PageSlab(page)) { |
926 | slab_err(s, page, "Attempt to free object(0x%p) " |
927 | "outside of slab", object); |
928 | } else if (!page->slab) { |
929 | printk(KERN_ERR |
930 | "SLUB <none>: no slab for object 0x%p.\n", |
931 | object); |
932 | dump_stack(); |
933 | } else |
934 | object_err(s, page, object, |
935 | "page slab pointer corrupt."); |
936 | goto fail; |
937 | } |
938 | |
939 | /* Special debug activities for freeing objects */ |
940 | if (!PageSlubFrozen(page) && !page->freelist) |
941 | remove_full(s, page); |
942 | if (s->flags & SLAB_STORE_USER) |
943 | set_track(s, object, TRACK_FREE, addr); |
944 | trace(s, page, object, 0); |
945 | init_object(s, object, 0); |
946 | return 1; |
947 | |
948 | fail: |
949 | slab_fix(s, "Object at 0x%p not freed", object); |
950 | return 0; |
951 | } |
952 | |
953 | static int __init setup_slub_debug(char *str) |
954 | { |
955 | slub_debug = DEBUG_DEFAULT_FLAGS; |
956 | if (*str++ != '=' || !*str) |
957 | /* |
958 | * No options specified. Switch on full debugging. |
959 | */ |
960 | goto out; |
961 | |
962 | if (*str == ',') |
963 | /* |
964 | * No options but restriction on slabs. This means full |
965 | * debugging for slabs matching a pattern. |
966 | */ |
967 | goto check_slabs; |
968 | |
969 | if (tolower(*str) == 'o') { |
970 | /* |
971 | * Avoid enabling debugging on caches if its minimum order |
972 | * would increase as a result. |
973 | */ |
974 | disable_higher_order_debug = 1; |
975 | goto out; |
976 | } |
977 | |
978 | slub_debug = 0; |
979 | if (*str == '-') |
980 | /* |
981 | * Switch off all debugging measures. |
982 | */ |
983 | goto out; |
984 | |
985 | /* |
986 | * Determine which debug features should be switched on |
987 | */ |
988 | for (; *str && *str != ','; str++) { |
989 | switch (tolower(*str)) { |
990 | case 'f': |
991 | slub_debug |= SLAB_DEBUG_FREE; |
992 | break; |
993 | case 'z': |
994 | slub_debug |= SLAB_RED_ZONE; |
995 | break; |
996 | case 'p': |
997 | slub_debug |= SLAB_POISON; |
998 | break; |
999 | case 'u': |
1000 | slub_debug |= SLAB_STORE_USER; |
1001 | break; |
1002 | case 't': |
1003 | slub_debug |= SLAB_TRACE; |
1004 | break; |
1005 | case 'a': |
1006 | slub_debug |= SLAB_FAILSLAB; |
1007 | break; |
1008 | default: |
1009 | printk(KERN_ERR "slub_debug option '%c' " |
1010 | "unknown. skipped\n", *str); |
1011 | } |
1012 | } |
1013 | |
1014 | check_slabs: |
1015 | if (*str == ',') |
1016 | slub_debug_slabs = str + 1; |
1017 | out: |
1018 | return 1; |
1019 | } |
1020 | |
1021 | __setup("slub_debug", setup_slub_debug); |
1022 | |
1023 | static unsigned long kmem_cache_flags(unsigned long objsize, |
1024 | unsigned long flags, const char *name, |
1025 | void (*ctor)(void *)) |
1026 | { |
1027 | /* |
1028 | * Enable debugging if selected on the kernel commandline. |
1029 | */ |
1030 | if (slub_debug && (!slub_debug_slabs || |
1031 | !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)))) |
1032 | flags |= slub_debug; |
1033 | |
1034 | return flags; |
1035 | } |
1036 | #else |
1037 | static inline void setup_object_debug(struct kmem_cache *s, |
1038 | struct page *page, void *object) {} |
1039 | |
1040 | static inline int alloc_debug_processing(struct kmem_cache *s, |
1041 | struct page *page, void *object, unsigned long addr) { return 0; } |
1042 | |
1043 | static inline int free_debug_processing(struct kmem_cache *s, |
1044 | struct page *page, void *object, unsigned long addr) { return 0; } |
1045 | |
1046 | static inline int slab_pad_check(struct kmem_cache *s, struct page *page) |
1047 | { return 1; } |
1048 | static inline int check_object(struct kmem_cache *s, struct page *page, |
1049 | void *object, int active) { return 1; } |
1050 | static inline void add_full(struct kmem_cache_node *n, struct page *page) {} |
1051 | static inline unsigned long kmem_cache_flags(unsigned long objsize, |
1052 | unsigned long flags, const char *name, |
1053 | void (*ctor)(void *)) |
1054 | { |
1055 | return flags; |
1056 | } |
1057 | #define slub_debug 0 |
1058 | |
1059 | #define disable_higher_order_debug 0 |
1060 | |
1061 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) |
1062 | { return 0; } |
1063 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) |
1064 | { return 0; } |
1065 | static inline void inc_slabs_node(struct kmem_cache *s, int node, |
1066 | int objects) {} |
1067 | static inline void dec_slabs_node(struct kmem_cache *s, int node, |
1068 | int objects) {} |
1069 | #endif |
1070 | |
1071 | /* |
1072 | * Slab allocation and freeing |
1073 | */ |
1074 | static inline struct page *alloc_slab_page(gfp_t flags, int node, |
1075 | struct kmem_cache_order_objects oo) |
1076 | { |
1077 | int order = oo_order(oo); |
1078 | |
1079 | flags |= __GFP_NOTRACK; |
1080 | |
1081 | if (node == NUMA_NO_NODE) |
1082 | return alloc_pages(flags, order); |
1083 | else |
1084 | return alloc_pages_exact_node(node, flags, order); |
1085 | } |
1086 | |
1087 | static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) |
1088 | { |
1089 | struct page *page; |
1090 | struct kmem_cache_order_objects oo = s->oo; |
1091 | gfp_t alloc_gfp; |
1092 | |
1093 | flags |= s->allocflags; |
1094 | |
1095 | /* |
1096 | * Let the initial higher-order allocation fail under memory pressure |
1097 | * so we fall-back to the minimum order allocation. |
1098 | */ |
1099 | alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL; |
1100 | |
1101 | page = alloc_slab_page(alloc_gfp, node, oo); |
1102 | if (unlikely(!page)) { |
1103 | oo = s->min; |
1104 | /* |
1105 | * Allocation may have failed due to fragmentation. |
1106 | * Try a lower order alloc if possible |
1107 | */ |
1108 | page = alloc_slab_page(flags, node, oo); |
1109 | if (!page) |
1110 | return NULL; |
1111 | |
1112 | stat(s, ORDER_FALLBACK); |
1113 | } |
1114 | |
1115 | if (kmemcheck_enabled |
1116 | && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) { |
1117 | int pages = 1 << oo_order(oo); |
1118 | |
1119 | kmemcheck_alloc_shadow(page, oo_order(oo), flags, node); |
1120 | |
1121 | /* |
1122 | * Objects from caches that have a constructor don't get |
1123 | * cleared when they're allocated, so we need to do it here. |
1124 | */ |
1125 | if (s->ctor) |
1126 | kmemcheck_mark_uninitialized_pages(page, pages); |
1127 | else |
1128 | kmemcheck_mark_unallocated_pages(page, pages); |
1129 | } |
1130 | |
1131 | page->objects = oo_objects(oo); |
1132 | mod_zone_page_state(page_zone(page), |
1133 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? |
1134 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, |
1135 | 1 << oo_order(oo)); |
1136 | |
1137 | return page; |
1138 | } |
1139 | |
1140 | static void setup_object(struct kmem_cache *s, struct page *page, |
1141 | void *object) |
1142 | { |
1143 | setup_object_debug(s, page, object); |
1144 | if (unlikely(s->ctor)) |
1145 | s->ctor(object); |
1146 | } |
1147 | |
1148 | static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) |
1149 | { |
1150 | struct page *page; |
1151 | void *start; |
1152 | void *last; |
1153 | void *p; |
1154 | |
1155 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
1156 | |
1157 | page = allocate_slab(s, |
1158 | flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); |
1159 | if (!page) |
1160 | goto out; |
1161 | |
1162 | inc_slabs_node(s, page_to_nid(page), page->objects); |
1163 | page->slab = s; |
1164 | page->flags |= 1 << PG_slab; |
1165 | |
1166 | start = page_address(page); |
1167 | |
1168 | if (unlikely(s->flags & SLAB_POISON)) |
1169 | memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page)); |
1170 | |
1171 | last = start; |
1172 | for_each_object(p, s, start, page->objects) { |
1173 | setup_object(s, page, last); |
1174 | set_freepointer(s, last, p); |
1175 | last = p; |
1176 | } |
1177 | setup_object(s, page, last); |
1178 | set_freepointer(s, last, NULL); |
1179 | |
1180 | page->freelist = start; |
1181 | page->inuse = 0; |
1182 | out: |
1183 | return page; |
1184 | } |
1185 | |
1186 | static void __free_slab(struct kmem_cache *s, struct page *page) |
1187 | { |
1188 | int order = compound_order(page); |
1189 | int pages = 1 << order; |
1190 | |
1191 | if (kmem_cache_debug(s)) { |
1192 | void *p; |
1193 | |
1194 | slab_pad_check(s, page); |
1195 | for_each_object(p, s, page_address(page), |
1196 | page->objects) |
1197 | check_object(s, page, p, 0); |
1198 | } |
1199 | |
1200 | kmemcheck_free_shadow(page, compound_order(page)); |
1201 | |
1202 | mod_zone_page_state(page_zone(page), |
1203 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? |
1204 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, |
1205 | -pages); |
1206 | |
1207 | __ClearPageSlab(page); |
1208 | reset_page_mapcount(page); |
1209 | if (current->reclaim_state) |
1210 | current->reclaim_state->reclaimed_slab += pages; |
1211 | __free_pages(page, order); |
1212 | } |
1213 | |
1214 | static void rcu_free_slab(struct rcu_head *h) |
1215 | { |
1216 | struct page *page; |
1217 | |
1218 | page = container_of((struct list_head *)h, struct page, lru); |
1219 | __free_slab(page->slab, page); |
1220 | } |
1221 | |
1222 | static void free_slab(struct kmem_cache *s, struct page *page) |
1223 | { |
1224 | if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { |
1225 | /* |
1226 | * RCU free overloads the RCU head over the LRU |
1227 | */ |
1228 | struct rcu_head *head = (void *)&page->lru; |
1229 | |
1230 | call_rcu(head, rcu_free_slab); |
1231 | } else |
1232 | __free_slab(s, page); |
1233 | } |
1234 | |
1235 | static void discard_slab(struct kmem_cache *s, struct page *page) |
1236 | { |
1237 | dec_slabs_node(s, page_to_nid(page), page->objects); |
1238 | free_slab(s, page); |
1239 | } |
1240 | |
1241 | /* |
1242 | * Per slab locking using the pagelock |
1243 | */ |
1244 | static __always_inline void slab_lock(struct page *page) |
1245 | { |
1246 | bit_spin_lock(PG_locked, &page->flags); |
1247 | } |
1248 | |
1249 | static __always_inline void slab_unlock(struct page *page) |
1250 | { |
1251 | __bit_spin_unlock(PG_locked, &page->flags); |
1252 | } |
1253 | |
1254 | static __always_inline int slab_trylock(struct page *page) |
1255 | { |
1256 | int rc = 1; |
1257 | |
1258 | rc = bit_spin_trylock(PG_locked, &page->flags); |
1259 | return rc; |
1260 | } |
1261 | |
1262 | /* |
1263 | * Management of partially allocated slabs |
1264 | */ |
1265 | static void add_partial(struct kmem_cache_node *n, |
1266 | struct page *page, int tail) |
1267 | { |
1268 | spin_lock(&n->list_lock); |
1269 | n->nr_partial++; |
1270 | if (tail) |
1271 | list_add_tail(&page->lru, &n->partial); |
1272 | else |
1273 | list_add(&page->lru, &n->partial); |
1274 | spin_unlock(&n->list_lock); |
1275 | } |
1276 | |
1277 | static void remove_partial(struct kmem_cache *s, struct page *page) |
1278 | { |
1279 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); |
1280 | |
1281 | spin_lock(&n->list_lock); |
1282 | list_del(&page->lru); |
1283 | n->nr_partial--; |
1284 | spin_unlock(&n->list_lock); |
1285 | } |
1286 | |
1287 | /* |
1288 | * Lock slab and remove from the partial list. |
1289 | * |
1290 | * Must hold list_lock. |
1291 | */ |
1292 | static inline int lock_and_freeze_slab(struct kmem_cache_node *n, |
1293 | struct page *page) |
1294 | { |
1295 | if (slab_trylock(page)) { |
1296 | list_del(&page->lru); |
1297 | n->nr_partial--; |
1298 | __SetPageSlubFrozen(page); |
1299 | return 1; |
1300 | } |
1301 | return 0; |
1302 | } |
1303 | |
1304 | /* |
1305 | * Try to allocate a partial slab from a specific node. |
1306 | */ |
1307 | static struct page *get_partial_node(struct kmem_cache_node *n) |
1308 | { |
1309 | struct page *page; |
1310 | |
1311 | /* |
1312 | * Racy check. If we mistakenly see no partial slabs then we |
1313 | * just allocate an empty slab. If we mistakenly try to get a |
1314 | * partial slab and there is none available then get_partials() |
1315 | * will return NULL. |
1316 | */ |
1317 | if (!n || !n->nr_partial) |
1318 | return NULL; |
1319 | |
1320 | spin_lock(&n->list_lock); |
1321 | list_for_each_entry(page, &n->partial, lru) |
1322 | if (lock_and_freeze_slab(n, page)) |
1323 | goto out; |
1324 | page = NULL; |
1325 | out: |
1326 | spin_unlock(&n->list_lock); |
1327 | return page; |
1328 | } |
1329 | |
1330 | /* |
1331 | * Get a page from somewhere. Search in increasing NUMA distances. |
1332 | */ |
1333 | static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags) |
1334 | { |
1335 | #ifdef CONFIG_NUMA |
1336 | struct zonelist *zonelist; |
1337 | struct zoneref *z; |
1338 | struct zone *zone; |
1339 | enum zone_type high_zoneidx = gfp_zone(flags); |
1340 | struct page *page; |
1341 | |
1342 | /* |
1343 | * The defrag ratio allows a configuration of the tradeoffs between |
1344 | * inter node defragmentation and node local allocations. A lower |
1345 | * defrag_ratio increases the tendency to do local allocations |
1346 | * instead of attempting to obtain partial slabs from other nodes. |
1347 | * |
1348 | * If the defrag_ratio is set to 0 then kmalloc() always |
1349 | * returns node local objects. If the ratio is higher then kmalloc() |
1350 | * may return off node objects because partial slabs are obtained |
1351 | * from other nodes and filled up. |
1352 | * |
1353 | * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes |
1354 | * defrag_ratio = 1000) then every (well almost) allocation will |
1355 | * first attempt to defrag slab caches on other nodes. This means |
1356 | * scanning over all nodes to look for partial slabs which may be |
1357 | * expensive if we do it every time we are trying to find a slab |
1358 | * with available objects. |
1359 | */ |
1360 | if (!s->remote_node_defrag_ratio || |
1361 | get_cycles() % 1024 > s->remote_node_defrag_ratio) |
1362 | return NULL; |
1363 | |
1364 | get_mems_allowed(); |
1365 | zonelist = node_zonelist(slab_node(current->mempolicy), flags); |
1366 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
1367 | struct kmem_cache_node *n; |
1368 | |
1369 | n = get_node(s, zone_to_nid(zone)); |
1370 | |
1371 | if (n && cpuset_zone_allowed_hardwall(zone, flags) && |
1372 | n->nr_partial > s->min_partial) { |
1373 | page = get_partial_node(n); |
1374 | if (page) { |
1375 | put_mems_allowed(); |
1376 | return page; |
1377 | } |
1378 | } |
1379 | } |
1380 | put_mems_allowed(); |
1381 | #endif |
1382 | return NULL; |
1383 | } |
1384 | |
1385 | /* |
1386 | * Get a partial page, lock it and return it. |
1387 | */ |
1388 | static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) |
1389 | { |
1390 | struct page *page; |
1391 | int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node; |
1392 | |
1393 | page = get_partial_node(get_node(s, searchnode)); |
1394 | if (page || node != -1) |
1395 | return page; |
1396 | |
1397 | return get_any_partial(s, flags); |
1398 | } |
1399 | |
1400 | /* |
1401 | * Move a page back to the lists. |
1402 | * |
1403 | * Must be called with the slab lock held. |
1404 | * |
1405 | * On exit the slab lock will have been dropped. |
1406 | */ |
1407 | static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail) |
1408 | { |
1409 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); |
1410 | |
1411 | __ClearPageSlubFrozen(page); |
1412 | if (page->inuse) { |
1413 | |
1414 | if (page->freelist) { |
1415 | add_partial(n, page, tail); |
1416 | stat(s, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD); |
1417 | } else { |
1418 | stat(s, DEACTIVATE_FULL); |
1419 | if (kmem_cache_debug(s) && (s->flags & SLAB_STORE_USER)) |
1420 | add_full(n, page); |
1421 | } |
1422 | slab_unlock(page); |
1423 | } else { |
1424 | stat(s, DEACTIVATE_EMPTY); |
1425 | if (n->nr_partial < s->min_partial) { |
1426 | /* |
1427 | * Adding an empty slab to the partial slabs in order |
1428 | * to avoid page allocator overhead. This slab needs |
1429 | * to come after the other slabs with objects in |
1430 | * so that the others get filled first. That way the |
1431 | * size of the partial list stays small. |
1432 | * |
1433 | * kmem_cache_shrink can reclaim any empty slabs from |
1434 | * the partial list. |
1435 | */ |
1436 | add_partial(n, page, 1); |
1437 | slab_unlock(page); |
1438 | } else { |
1439 | slab_unlock(page); |
1440 | stat(s, FREE_SLAB); |
1441 | discard_slab(s, page); |
1442 | } |
1443 | } |
1444 | } |
1445 | |
1446 | /* |
1447 | * Remove the cpu slab |
1448 | */ |
1449 | static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) |
1450 | { |
1451 | struct page *page = c->page; |
1452 | int tail = 1; |
1453 | |
1454 | if (page->freelist) |
1455 | stat(s, DEACTIVATE_REMOTE_FREES); |
1456 | /* |
1457 | * Merge cpu freelist into slab freelist. Typically we get here |
1458 | * because both freelists are empty. So this is unlikely |
1459 | * to occur. |
1460 | */ |
1461 | while (unlikely(c->freelist)) { |
1462 | void **object; |
1463 | |
1464 | tail = 0; /* Hot objects. Put the slab first */ |
1465 | |
1466 | /* Retrieve object from cpu_freelist */ |
1467 | object = c->freelist; |
1468 | c->freelist = get_freepointer(s, c->freelist); |
1469 | |
1470 | /* And put onto the regular freelist */ |
1471 | set_freepointer(s, object, page->freelist); |
1472 | page->freelist = object; |
1473 | page->inuse--; |
1474 | } |
1475 | c->page = NULL; |
1476 | unfreeze_slab(s, page, tail); |
1477 | } |
1478 | |
1479 | static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) |
1480 | { |
1481 | stat(s, CPUSLAB_FLUSH); |
1482 | slab_lock(c->page); |
1483 | deactivate_slab(s, c); |
1484 | } |
1485 | |
1486 | /* |
1487 | * Flush cpu slab. |
1488 | * |
1489 | * Called from IPI handler with interrupts disabled. |
1490 | */ |
1491 | static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) |
1492 | { |
1493 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); |
1494 | |
1495 | if (likely(c && c->page)) |
1496 | flush_slab(s, c); |
1497 | } |
1498 | |
1499 | static void flush_cpu_slab(void *d) |
1500 | { |
1501 | struct kmem_cache *s = d; |
1502 | |
1503 | __flush_cpu_slab(s, smp_processor_id()); |
1504 | } |
1505 | |
1506 | static void flush_all(struct kmem_cache *s) |
1507 | { |
1508 | on_each_cpu(flush_cpu_slab, s, 1); |
1509 | } |
1510 | |
1511 | /* |
1512 | * Check if the objects in a per cpu structure fit numa |
1513 | * locality expectations. |
1514 | */ |
1515 | static inline int node_match(struct kmem_cache_cpu *c, int node) |
1516 | { |
1517 | #ifdef CONFIG_NUMA |
1518 | if (node != NUMA_NO_NODE && c->node != node) |
1519 | return 0; |
1520 | #endif |
1521 | return 1; |
1522 | } |
1523 | |
1524 | static int count_free(struct page *page) |
1525 | { |
1526 | return page->objects - page->inuse; |
1527 | } |
1528 | |
1529 | static unsigned long count_partial(struct kmem_cache_node *n, |
1530 | int (*get_count)(struct page *)) |
1531 | { |
1532 | unsigned long flags; |
1533 | unsigned long x = 0; |
1534 | struct page *page; |
1535 | |
1536 | spin_lock_irqsave(&n->list_lock, flags); |
1537 | list_for_each_entry(page, &n->partial, lru) |
1538 | x += get_count(page); |
1539 | spin_unlock_irqrestore(&n->list_lock, flags); |
1540 | return x; |
1541 | } |
1542 | |
1543 | static inline unsigned long node_nr_objs(struct kmem_cache_node *n) |
1544 | { |
1545 | #ifdef CONFIG_SLUB_DEBUG |
1546 | return atomic_long_read(&n->total_objects); |
1547 | #else |
1548 | return 0; |
1549 | #endif |
1550 | } |
1551 | |
1552 | static noinline void |
1553 | slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) |
1554 | { |
1555 | int node; |
1556 | |
1557 | printk(KERN_WARNING |
1558 | "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
1559 | nid, gfpflags); |
1560 | printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, " |
1561 | "default order: %d, min order: %d\n", s->name, s->objsize, |
1562 | s->size, oo_order(s->oo), oo_order(s->min)); |
1563 | |
1564 | if (oo_order(s->min) > get_order(s->objsize)) |
1565 | printk(KERN_WARNING " %s debugging increased min order, use " |
1566 | "slub_debug=O to disable.\n", s->name); |
1567 | |
1568 | for_each_online_node(node) { |
1569 | struct kmem_cache_node *n = get_node(s, node); |
1570 | unsigned long nr_slabs; |
1571 | unsigned long nr_objs; |
1572 | unsigned long nr_free; |
1573 | |
1574 | if (!n) |
1575 | continue; |
1576 | |
1577 | nr_free = count_partial(n, count_free); |
1578 | nr_slabs = node_nr_slabs(n); |
1579 | nr_objs = node_nr_objs(n); |
1580 | |
1581 | printk(KERN_WARNING |
1582 | " node %d: slabs: %ld, objs: %ld, free: %ld\n", |
1583 | node, nr_slabs, nr_objs, nr_free); |
1584 | } |
1585 | } |
1586 | |
1587 | /* |
1588 | * Slow path. The lockless freelist is empty or we need to perform |
1589 | * debugging duties. |
1590 | * |
1591 | * Interrupts are disabled. |
1592 | * |
1593 | * Processing is still very fast if new objects have been freed to the |
1594 | * regular freelist. In that case we simply take over the regular freelist |
1595 | * as the lockless freelist and zap the regular freelist. |
1596 | * |
1597 | * If that is not working then we fall back to the partial lists. We take the |
1598 | * first element of the freelist as the object to allocate now and move the |
1599 | * rest of the freelist to the lockless freelist. |
1600 | * |
1601 | * And if we were unable to get a new slab from the partial slab lists then |
1602 | * we need to allocate a new slab. This is the slowest path since it involves |
1603 | * a call to the page allocator and the setup of a new slab. |
1604 | */ |
1605 | static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, |
1606 | unsigned long addr, struct kmem_cache_cpu *c) |
1607 | { |
1608 | void **object; |
1609 | struct page *new; |
1610 | |
1611 | /* We handle __GFP_ZERO in the caller */ |
1612 | gfpflags &= ~__GFP_ZERO; |
1613 | |
1614 | if (!c->page) |
1615 | goto new_slab; |
1616 | |
1617 | slab_lock(c->page); |
1618 | if (unlikely(!node_match(c, node))) |
1619 | goto another_slab; |
1620 | |
1621 | stat(s, ALLOC_REFILL); |
1622 | |
1623 | load_freelist: |
1624 | object = c->page->freelist; |
1625 | if (unlikely(!object)) |
1626 | goto another_slab; |
1627 | if (kmem_cache_debug(s)) |
1628 | goto debug; |
1629 | |
1630 | c->freelist = get_freepointer(s, object); |
1631 | c->page->inuse = c->page->objects; |
1632 | c->page->freelist = NULL; |
1633 | c->node = page_to_nid(c->page); |
1634 | unlock_out: |
1635 | slab_unlock(c->page); |
1636 | stat(s, ALLOC_SLOWPATH); |
1637 | return object; |
1638 | |
1639 | another_slab: |
1640 | deactivate_slab(s, c); |
1641 | |
1642 | new_slab: |
1643 | new = get_partial(s, gfpflags, node); |
1644 | if (new) { |
1645 | c->page = new; |
1646 | stat(s, ALLOC_FROM_PARTIAL); |
1647 | goto load_freelist; |
1648 | } |
1649 | |
1650 | if (gfpflags & __GFP_WAIT) |
1651 | local_irq_enable(); |
1652 | |
1653 | new = new_slab(s, gfpflags, node); |
1654 | |
1655 | if (gfpflags & __GFP_WAIT) |
1656 | local_irq_disable(); |
1657 | |
1658 | if (new) { |
1659 | c = __this_cpu_ptr(s->cpu_slab); |
1660 | stat(s, ALLOC_SLAB); |
1661 | if (c->page) |
1662 | flush_slab(s, c); |
1663 | slab_lock(new); |
1664 | __SetPageSlubFrozen(new); |
1665 | c->page = new; |
1666 | goto load_freelist; |
1667 | } |
1668 | if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit()) |
1669 | slab_out_of_memory(s, gfpflags, node); |
1670 | return NULL; |
1671 | debug: |
1672 | if (!alloc_debug_processing(s, c->page, object, addr)) |
1673 | goto another_slab; |
1674 | |
1675 | c->page->inuse++; |
1676 | c->page->freelist = get_freepointer(s, object); |
1677 | c->node = -1; |
1678 | goto unlock_out; |
1679 | } |
1680 | |
1681 | /* |
1682 | * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc) |
1683 | * have the fastpath folded into their functions. So no function call |
1684 | * overhead for requests that can be satisfied on the fastpath. |
1685 | * |
1686 | * The fastpath works by first checking if the lockless freelist can be used. |
1687 | * If not then __slab_alloc is called for slow processing. |
1688 | * |
1689 | * Otherwise we can simply pick the next object from the lockless free list. |
1690 | */ |
1691 | static __always_inline void *slab_alloc(struct kmem_cache *s, |
1692 | gfp_t gfpflags, int node, unsigned long addr) |
1693 | { |
1694 | void **object; |
1695 | struct kmem_cache_cpu *c; |
1696 | unsigned long flags; |
1697 | |
1698 | gfpflags &= gfp_allowed_mask; |
1699 | |
1700 | lockdep_trace_alloc(gfpflags); |
1701 | might_sleep_if(gfpflags & __GFP_WAIT); |
1702 | |
1703 | if (should_failslab(s->objsize, gfpflags, s->flags)) |
1704 | return NULL; |
1705 | |
1706 | local_irq_save(flags); |
1707 | c = __this_cpu_ptr(s->cpu_slab); |
1708 | object = c->freelist; |
1709 | if (unlikely(!object || !node_match(c, node))) |
1710 | |
1711 | object = __slab_alloc(s, gfpflags, node, addr, c); |
1712 | |
1713 | else { |
1714 | c->freelist = get_freepointer(s, object); |
1715 | stat(s, ALLOC_FASTPATH); |
1716 | } |
1717 | local_irq_restore(flags); |
1718 | |
1719 | if (unlikely(gfpflags & __GFP_ZERO) && object) |
1720 | memset(object, 0, s->objsize); |
1721 | |
1722 | kmemcheck_slab_alloc(s, gfpflags, object, s->objsize); |
1723 | kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, gfpflags); |
1724 | |
1725 | return object; |
1726 | } |
1727 | |
1728 | void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) |
1729 | { |
1730 | void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_); |
1731 | |
1732 | trace_kmem_cache_alloc(_RET_IP_, ret, s->objsize, s->size, gfpflags); |
1733 | |
1734 | return ret; |
1735 | } |
1736 | EXPORT_SYMBOL(kmem_cache_alloc); |
1737 | |
1738 | #ifdef CONFIG_TRACING |
1739 | void *kmem_cache_alloc_notrace(struct kmem_cache *s, gfp_t gfpflags) |
1740 | { |
1741 | return slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_); |
1742 | } |
1743 | EXPORT_SYMBOL(kmem_cache_alloc_notrace); |
1744 | #endif |
1745 | |
1746 | #ifdef CONFIG_NUMA |
1747 | void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node) |
1748 | { |
1749 | void *ret = slab_alloc(s, gfpflags, node, _RET_IP_); |
1750 | |
1751 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
1752 | s->objsize, s->size, gfpflags, node); |
1753 | |
1754 | return ret; |
1755 | } |
1756 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
1757 | #endif |
1758 | |
1759 | #ifdef CONFIG_TRACING |
1760 | void *kmem_cache_alloc_node_notrace(struct kmem_cache *s, |
1761 | gfp_t gfpflags, |
1762 | int node) |
1763 | { |
1764 | return slab_alloc(s, gfpflags, node, _RET_IP_); |
1765 | } |
1766 | EXPORT_SYMBOL(kmem_cache_alloc_node_notrace); |
1767 | #endif |
1768 | |
1769 | /* |
1770 | * Slow patch handling. This may still be called frequently since objects |
1771 | * have a longer lifetime than the cpu slabs in most processing loads. |
1772 | * |
1773 | * So we still attempt to reduce cache line usage. Just take the slab |
1774 | * lock and free the item. If there is no additional partial page |
1775 | * handling required then we can return immediately. |
1776 | */ |
1777 | static void __slab_free(struct kmem_cache *s, struct page *page, |
1778 | void *x, unsigned long addr) |
1779 | { |
1780 | void *prior; |
1781 | void **object = (void *)x; |
1782 | |
1783 | stat(s, FREE_SLOWPATH); |
1784 | slab_lock(page); |
1785 | |
1786 | if (kmem_cache_debug(s)) |
1787 | goto debug; |
1788 | |
1789 | checks_ok: |
1790 | prior = page->freelist; |
1791 | set_freepointer(s, object, prior); |
1792 | page->freelist = object; |
1793 | page->inuse--; |
1794 | |
1795 | if (unlikely(PageSlubFrozen(page))) { |
1796 | stat(s, FREE_FROZEN); |
1797 | goto out_unlock; |
1798 | } |
1799 | |
1800 | if (unlikely(!page->inuse)) |
1801 | goto slab_empty; |
1802 | |
1803 | /* |
1804 | * Objects left in the slab. If it was not on the partial list before |
1805 | * then add it. |
1806 | */ |
1807 | if (unlikely(!prior)) { |
1808 | add_partial(get_node(s, page_to_nid(page)), page, 1); |
1809 | stat(s, FREE_ADD_PARTIAL); |
1810 | } |
1811 | |
1812 | out_unlock: |
1813 | slab_unlock(page); |
1814 | return; |
1815 | |
1816 | slab_empty: |
1817 | if (prior) { |
1818 | /* |
1819 | * Slab still on the partial list. |
1820 | */ |
1821 | remove_partial(s, page); |
1822 | stat(s, FREE_REMOVE_PARTIAL); |
1823 | } |
1824 | slab_unlock(page); |
1825 | stat(s, FREE_SLAB); |
1826 | discard_slab(s, page); |
1827 | return; |
1828 | |
1829 | debug: |
1830 | if (!free_debug_processing(s, page, x, addr)) |
1831 | goto out_unlock; |
1832 | goto checks_ok; |
1833 | } |
1834 | |
1835 | /* |
1836 | * Fastpath with forced inlining to produce a kfree and kmem_cache_free that |
1837 | * can perform fastpath freeing without additional function calls. |
1838 | * |
1839 | * The fastpath is only possible if we are freeing to the current cpu slab |
1840 | * of this processor. This typically the case if we have just allocated |
1841 | * the item before. |
1842 | * |
1843 | * If fastpath is not possible then fall back to __slab_free where we deal |
1844 | * with all sorts of special processing. |
1845 | */ |
1846 | static __always_inline void slab_free(struct kmem_cache *s, |
1847 | struct page *page, void *x, unsigned long addr) |
1848 | { |
1849 | void **object = (void *)x; |
1850 | struct kmem_cache_cpu *c; |
1851 | unsigned long flags; |
1852 | |
1853 | kmemleak_free_recursive(x, s->flags); |
1854 | local_irq_save(flags); |
1855 | c = __this_cpu_ptr(s->cpu_slab); |
1856 | kmemcheck_slab_free(s, object, s->objsize); |
1857 | debug_check_no_locks_freed(object, s->objsize); |
1858 | if (!(s->flags & SLAB_DEBUG_OBJECTS)) |
1859 | debug_check_no_obj_freed(object, s->objsize); |
1860 | if (likely(page == c->page && c->node >= 0)) { |
1861 | set_freepointer(s, object, c->freelist); |
1862 | c->freelist = object; |
1863 | stat(s, FREE_FASTPATH); |
1864 | } else |
1865 | __slab_free(s, page, x, addr); |
1866 | |
1867 | local_irq_restore(flags); |
1868 | } |
1869 | |
1870 | void kmem_cache_free(struct kmem_cache *s, void *x) |
1871 | { |
1872 | struct page *page; |
1873 | |
1874 | page = virt_to_head_page(x); |
1875 | |
1876 | slab_free(s, page, x, _RET_IP_); |
1877 | |
1878 | trace_kmem_cache_free(_RET_IP_, x); |
1879 | } |
1880 | EXPORT_SYMBOL(kmem_cache_free); |
1881 | |
1882 | /* Figure out on which slab page the object resides */ |
1883 | static struct page *get_object_page(const void *x) |
1884 | { |
1885 | struct page *page = virt_to_head_page(x); |
1886 | |
1887 | if (!PageSlab(page)) |
1888 | return NULL; |
1889 | |
1890 | return page; |
1891 | } |
1892 | |
1893 | /* |
1894 | * Object placement in a slab is made very easy because we always start at |
1895 | * offset 0. If we tune the size of the object to the alignment then we can |
1896 | * get the required alignment by putting one properly sized object after |
1897 | * another. |
1898 | * |
1899 | * Notice that the allocation order determines the sizes of the per cpu |
1900 | * caches. Each processor has always one slab available for allocations. |
1901 | * Increasing the allocation order reduces the number of times that slabs |
1902 | * must be moved on and off the partial lists and is therefore a factor in |
1903 | * locking overhead. |
1904 | */ |
1905 | |
1906 | /* |
1907 | * Mininum / Maximum order of slab pages. This influences locking overhead |
1908 | * and slab fragmentation. A higher order reduces the number of partial slabs |
1909 | * and increases the number of allocations possible without having to |
1910 | * take the list_lock. |
1911 | */ |
1912 | static int slub_min_order; |
1913 | static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER; |
1914 | static int slub_min_objects; |
1915 | |
1916 | /* |
1917 | * Merge control. If this is set then no merging of slab caches will occur. |
1918 | * (Could be removed. This was introduced to pacify the merge skeptics.) |
1919 | */ |
1920 | static int slub_nomerge; |
1921 | |
1922 | /* |
1923 | * Calculate the order of allocation given an slab object size. |
1924 | * |
1925 | * The order of allocation has significant impact on performance and other |
1926 | * system components. Generally order 0 allocations should be preferred since |
1927 | * order 0 does not cause fragmentation in the page allocator. Larger objects |
1928 | * be problematic to put into order 0 slabs because there may be too much |
1929 | * unused space left. We go to a higher order if more than 1/16th of the slab |
1930 | * would be wasted. |
1931 | * |
1932 | * In order to reach satisfactory performance we must ensure that a minimum |
1933 | * number of objects is in one slab. Otherwise we may generate too much |
1934 | * activity on the partial lists which requires taking the list_lock. This is |
1935 | * less a concern for large slabs though which are rarely used. |
1936 | * |
1937 | * slub_max_order specifies the order where we begin to stop considering the |
1938 | * number of objects in a slab as critical. If we reach slub_max_order then |
1939 | * we try to keep the page order as low as possible. So we accept more waste |
1940 | * of space in favor of a small page order. |
1941 | * |
1942 | * Higher order allocations also allow the placement of more objects in a |
1943 | * slab and thereby reduce object handling overhead. If the user has |
1944 | * requested a higher mininum order then we start with that one instead of |
1945 | * the smallest order which will fit the object. |
1946 | */ |
1947 | static inline int slab_order(int size, int min_objects, |
1948 | int max_order, int fract_leftover) |
1949 | { |
1950 | int order; |
1951 | int rem; |
1952 | int min_order = slub_min_order; |
1953 | |
1954 | if ((PAGE_SIZE << min_order) / size > MAX_OBJS_PER_PAGE) |
1955 | return get_order(size * MAX_OBJS_PER_PAGE) - 1; |
1956 | |
1957 | for (order = max(min_order, |
1958 | fls(min_objects * size - 1) - PAGE_SHIFT); |
1959 | order <= max_order; order++) { |
1960 | |
1961 | unsigned long slab_size = PAGE_SIZE << order; |
1962 | |
1963 | if (slab_size < min_objects * size) |
1964 | continue; |
1965 | |
1966 | rem = slab_size % size; |
1967 | |
1968 | if (rem <= slab_size / fract_leftover) |
1969 | break; |
1970 | |
1971 | } |
1972 | |
1973 | return order; |
1974 | } |
1975 | |
1976 | static inline int calculate_order(int size) |
1977 | { |
1978 | int order; |
1979 | int min_objects; |
1980 | int fraction; |
1981 | int max_objects; |
1982 | |
1983 | /* |
1984 | * Attempt to find best configuration for a slab. This |
1985 | * works by first attempting to generate a layout with |
1986 | * the best configuration and backing off gradually. |
1987 | * |
1988 | * First we reduce the acceptable waste in a slab. Then |
1989 | * we reduce the minimum objects required in a slab. |
1990 | */ |
1991 | min_objects = slub_min_objects; |
1992 | if (!min_objects) |
1993 | min_objects = 4 * (fls(nr_cpu_ids) + 1); |
1994 | max_objects = (PAGE_SIZE << slub_max_order)/size; |
1995 | min_objects = min(min_objects, max_objects); |
1996 | |
1997 | while (min_objects > 1) { |
1998 | fraction = 16; |
1999 | while (fraction >= 4) { |
2000 | order = slab_order(size, min_objects, |
2001 | slub_max_order, fraction); |
2002 | if (order <= slub_max_order) |
2003 | return order; |
2004 | fraction /= 2; |
2005 | } |
2006 | min_objects--; |
2007 | } |
2008 | |
2009 | /* |
2010 | * We were unable to place multiple objects in a slab. Now |
2011 | * lets see if we can place a single object there. |
2012 | */ |
2013 | order = slab_order(size, 1, slub_max_order, 1); |
2014 | if (order <= slub_max_order) |
2015 | return order; |
2016 | |
2017 | /* |
2018 | * Doh this slab cannot be placed using slub_max_order. |
2019 | */ |
2020 | order = slab_order(size, 1, MAX_ORDER, 1); |
2021 | if (order < MAX_ORDER) |
2022 | return order; |
2023 | return -ENOSYS; |
2024 | } |
2025 | |
2026 | /* |
2027 | * Figure out what the alignment of the objects will be. |
2028 | */ |
2029 | static unsigned long calculate_alignment(unsigned long flags, |
2030 | unsigned long align, unsigned long size) |
2031 | { |
2032 | /* |
2033 | * If the user wants hardware cache aligned objects then follow that |
2034 | * suggestion if the object is sufficiently large. |
2035 | * |
2036 | * The hardware cache alignment cannot override the specified |
2037 | * alignment though. If that is greater then use it. |
2038 | */ |
2039 | if (flags & SLAB_HWCACHE_ALIGN) { |
2040 | unsigned long ralign = cache_line_size(); |
2041 | while (size <= ralign / 2) |
2042 | ralign /= 2; |
2043 | align = max(align, ralign); |
2044 | } |
2045 | |
2046 | if (align < ARCH_SLAB_MINALIGN) |
2047 | align = ARCH_SLAB_MINALIGN; |
2048 | |
2049 | return ALIGN(align, sizeof(void *)); |
2050 | } |
2051 | |
2052 | static void |
2053 | init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s) |
2054 | { |
2055 | n->nr_partial = 0; |
2056 | spin_lock_init(&n->list_lock); |
2057 | INIT_LIST_HEAD(&n->partial); |
2058 | #ifdef CONFIG_SLUB_DEBUG |
2059 | atomic_long_set(&n->nr_slabs, 0); |
2060 | atomic_long_set(&n->total_objects, 0); |
2061 | INIT_LIST_HEAD(&n->full); |
2062 | #endif |
2063 | } |
2064 | |
2065 | static DEFINE_PER_CPU(struct kmem_cache_cpu, kmalloc_percpu[KMALLOC_CACHES]); |
2066 | |
2067 | static inline int alloc_kmem_cache_cpus(struct kmem_cache *s, gfp_t flags) |
2068 | { |
2069 | if (s < kmalloc_caches + KMALLOC_CACHES && s >= kmalloc_caches) |
2070 | /* |
2071 | * Boot time creation of the kmalloc array. Use static per cpu data |
2072 | * since the per cpu allocator is not available yet. |
2073 | */ |
2074 | s->cpu_slab = kmalloc_percpu + (s - kmalloc_caches); |
2075 | else |
2076 | s->cpu_slab = alloc_percpu(struct kmem_cache_cpu); |
2077 | |
2078 | if (!s->cpu_slab) |
2079 | return 0; |
2080 | |
2081 | return 1; |
2082 | } |
2083 | |
2084 | #ifdef CONFIG_NUMA |
2085 | /* |
2086 | * No kmalloc_node yet so do it by hand. We know that this is the first |
2087 | * slab on the node for this slabcache. There are no concurrent accesses |
2088 | * possible. |
2089 | * |
2090 | * Note that this function only works on the kmalloc_node_cache |
2091 | * when allocating for the kmalloc_node_cache. This is used for bootstrapping |
2092 | * memory on a fresh node that has no slab structures yet. |
2093 | */ |
2094 | static void early_kmem_cache_node_alloc(gfp_t gfpflags, int node) |
2095 | { |
2096 | struct page *page; |
2097 | struct kmem_cache_node *n; |
2098 | unsigned long flags; |
2099 | |
2100 | BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node)); |
2101 | |
2102 | page = new_slab(kmalloc_caches, gfpflags, node); |
2103 | |
2104 | BUG_ON(!page); |
2105 | if (page_to_nid(page) != node) { |
2106 | printk(KERN_ERR "SLUB: Unable to allocate memory from " |
2107 | "node %d\n", node); |
2108 | printk(KERN_ERR "SLUB: Allocating a useless per node structure " |
2109 | "in order to be able to continue\n"); |
2110 | } |
2111 | |
2112 | n = page->freelist; |
2113 | BUG_ON(!n); |
2114 | page->freelist = get_freepointer(kmalloc_caches, n); |
2115 | page->inuse++; |
2116 | kmalloc_caches->node[node] = n; |
2117 | #ifdef CONFIG_SLUB_DEBUG |
2118 | init_object(kmalloc_caches, n, 1); |
2119 | init_tracking(kmalloc_caches, n); |
2120 | #endif |
2121 | init_kmem_cache_node(n, kmalloc_caches); |
2122 | inc_slabs_node(kmalloc_caches, node, page->objects); |
2123 | |
2124 | /* |
2125 | * lockdep requires consistent irq usage for each lock |
2126 | * so even though there cannot be a race this early in |
2127 | * the boot sequence, we still disable irqs. |
2128 | */ |
2129 | local_irq_save(flags); |
2130 | add_partial(n, page, 0); |
2131 | local_irq_restore(flags); |
2132 | } |
2133 | |
2134 | static void free_kmem_cache_nodes(struct kmem_cache *s) |
2135 | { |
2136 | int node; |
2137 | |
2138 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2139 | struct kmem_cache_node *n = s->node[node]; |
2140 | if (n) |
2141 | kmem_cache_free(kmalloc_caches, n); |
2142 | s->node[node] = NULL; |
2143 | } |
2144 | } |
2145 | |
2146 | static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) |
2147 | { |
2148 | int node; |
2149 | |
2150 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2151 | struct kmem_cache_node *n; |
2152 | |
2153 | if (slab_state == DOWN) { |
2154 | early_kmem_cache_node_alloc(gfpflags, node); |
2155 | continue; |
2156 | } |
2157 | n = kmem_cache_alloc_node(kmalloc_caches, |
2158 | gfpflags, node); |
2159 | |
2160 | if (!n) { |
2161 | free_kmem_cache_nodes(s); |
2162 | return 0; |
2163 | } |
2164 | |
2165 | s->node[node] = n; |
2166 | init_kmem_cache_node(n, s); |
2167 | } |
2168 | return 1; |
2169 | } |
2170 | #else |
2171 | static void free_kmem_cache_nodes(struct kmem_cache *s) |
2172 | { |
2173 | } |
2174 | |
2175 | static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) |
2176 | { |
2177 | init_kmem_cache_node(&s->local_node, s); |
2178 | return 1; |
2179 | } |
2180 | #endif |
2181 | |
2182 | static void set_min_partial(struct kmem_cache *s, unsigned long min) |
2183 | { |
2184 | if (min < MIN_PARTIAL) |
2185 | min = MIN_PARTIAL; |
2186 | else if (min > MAX_PARTIAL) |
2187 | min = MAX_PARTIAL; |
2188 | s->min_partial = min; |
2189 | } |
2190 | |
2191 | /* |
2192 | * calculate_sizes() determines the order and the distribution of data within |
2193 | * a slab object. |
2194 | */ |
2195 | static int calculate_sizes(struct kmem_cache *s, int forced_order) |
2196 | { |
2197 | unsigned long flags = s->flags; |
2198 | unsigned long size = s->objsize; |
2199 | unsigned long align = s->align; |
2200 | int order; |
2201 | |
2202 | /* |
2203 | * Round up object size to the next word boundary. We can only |
2204 | * place the free pointer at word boundaries and this determines |
2205 | * the possible location of the free pointer. |
2206 | */ |
2207 | size = ALIGN(size, sizeof(void *)); |
2208 | |
2209 | #ifdef CONFIG_SLUB_DEBUG |
2210 | /* |
2211 | * Determine if we can poison the object itself. If the user of |
2212 | * the slab may touch the object after free or before allocation |
2213 | * then we should never poison the object itself. |
2214 | */ |
2215 | if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) && |
2216 | !s->ctor) |
2217 | s->flags |= __OBJECT_POISON; |
2218 | else |
2219 | s->flags &= ~__OBJECT_POISON; |
2220 | |
2221 | |
2222 | /* |
2223 | * If we are Redzoning then check if there is some space between the |
2224 | * end of the object and the free pointer. If not then add an |
2225 | * additional word to have some bytes to store Redzone information. |
2226 | */ |
2227 | if ((flags & SLAB_RED_ZONE) && size == s->objsize) |
2228 | size += sizeof(void *); |
2229 | #endif |
2230 | |
2231 | /* |
2232 | * With that we have determined the number of bytes in actual use |
2233 | * by the object. This is the potential offset to the free pointer. |
2234 | */ |
2235 | s->inuse = size; |
2236 | |
2237 | if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || |
2238 | s->ctor)) { |
2239 | /* |
2240 | * Relocate free pointer after the object if it is not |
2241 | * permitted to overwrite the first word of the object on |
2242 | * kmem_cache_free. |
2243 | * |
2244 | * This is the case if we do RCU, have a constructor or |
2245 | * destructor or are poisoning the objects. |
2246 | */ |
2247 | s->offset = size; |
2248 | size += sizeof(void *); |
2249 | } |
2250 | |
2251 | #ifdef CONFIG_SLUB_DEBUG |
2252 | if (flags & SLAB_STORE_USER) |
2253 | /* |
2254 | * Need to store information about allocs and frees after |
2255 | * the object. |
2256 | */ |
2257 | size += 2 * sizeof(struct track); |
2258 | |
2259 | if (flags & SLAB_RED_ZONE) |
2260 | /* |
2261 | * Add some empty padding so that we can catch |
2262 | * overwrites from earlier objects rather than let |
2263 | * tracking information or the free pointer be |
2264 | * corrupted if a user writes before the start |
2265 | * of the object. |
2266 | */ |
2267 | size += sizeof(void *); |
2268 | #endif |
2269 | |
2270 | /* |
2271 | * Determine the alignment based on various parameters that the |
2272 | * user specified and the dynamic determination of cache line size |
2273 | * on bootup. |
2274 | */ |
2275 | align = calculate_alignment(flags, align, s->objsize); |
2276 | s->align = align; |
2277 | |
2278 | /* |
2279 | * SLUB stores one object immediately after another beginning from |
2280 | * offset 0. In order to align the objects we have to simply size |
2281 | * each object to conform to the alignment. |
2282 | */ |
2283 | size = ALIGN(size, align); |
2284 | s->size = size; |
2285 | if (forced_order >= 0) |
2286 | order = forced_order; |
2287 | else |
2288 | order = calculate_order(size); |
2289 | |
2290 | if (order < 0) |
2291 | return 0; |
2292 | |
2293 | s->allocflags = 0; |
2294 | if (order) |
2295 | s->allocflags |= __GFP_COMP; |
2296 | |
2297 | if (s->flags & SLAB_CACHE_DMA) |
2298 | s->allocflags |= SLUB_DMA; |
2299 | |
2300 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
2301 | s->allocflags |= __GFP_RECLAIMABLE; |
2302 | |
2303 | /* |
2304 | * Determine the number of objects per slab |
2305 | */ |
2306 | s->oo = oo_make(order, size); |
2307 | s->min = oo_make(get_order(size), size); |
2308 | if (oo_objects(s->oo) > oo_objects(s->max)) |
2309 | s->max = s->oo; |
2310 | |
2311 | return !!oo_objects(s->oo); |
2312 | |
2313 | } |
2314 | |
2315 | static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, |
2316 | const char *name, size_t size, |
2317 | size_t align, unsigned long flags, |
2318 | void (*ctor)(void *)) |
2319 | { |
2320 | memset(s, 0, kmem_size); |
2321 | s->name = name; |
2322 | s->ctor = ctor; |
2323 | s->objsize = size; |
2324 | s->align = align; |
2325 | s->flags = kmem_cache_flags(size, flags, name, ctor); |
2326 | |
2327 | if (!calculate_sizes(s, -1)) |
2328 | goto error; |
2329 | if (disable_higher_order_debug) { |
2330 | /* |
2331 | * Disable debugging flags that store metadata if the min slab |
2332 | * order increased. |
2333 | */ |
2334 | if (get_order(s->size) > get_order(s->objsize)) { |
2335 | s->flags &= ~DEBUG_METADATA_FLAGS; |
2336 | s->offset = 0; |
2337 | if (!calculate_sizes(s, -1)) |
2338 | goto error; |
2339 | } |
2340 | } |
2341 | |
2342 | /* |
2343 | * The larger the object size is, the more pages we want on the partial |
2344 | * list to avoid pounding the page allocator excessively. |
2345 | */ |
2346 | set_min_partial(s, ilog2(s->size)); |
2347 | s->refcount = 1; |
2348 | #ifdef CONFIG_NUMA |
2349 | s->remote_node_defrag_ratio = 1000; |
2350 | #endif |
2351 | if (!init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA)) |
2352 | goto error; |
2353 | |
2354 | if (alloc_kmem_cache_cpus(s, gfpflags & ~SLUB_DMA)) |
2355 | return 1; |
2356 | |
2357 | free_kmem_cache_nodes(s); |
2358 | error: |
2359 | if (flags & SLAB_PANIC) |
2360 | panic("Cannot create slab %s size=%lu realsize=%u " |
2361 | "order=%u offset=%u flags=%lx\n", |
2362 | s->name, (unsigned long)size, s->size, oo_order(s->oo), |
2363 | s->offset, flags); |
2364 | return 0; |
2365 | } |
2366 | |
2367 | /* |
2368 | * Check if a given pointer is valid |
2369 | */ |
2370 | int kmem_ptr_validate(struct kmem_cache *s, const void *object) |
2371 | { |
2372 | struct page *page; |
2373 | |
2374 | if (!kern_ptr_validate(object, s->size)) |
2375 | return 0; |
2376 | |
2377 | page = get_object_page(object); |
2378 | |
2379 | if (!page || s != page->slab) |
2380 | /* No slab or wrong slab */ |
2381 | return 0; |
2382 | |
2383 | if (!check_valid_pointer(s, page, object)) |
2384 | return 0; |
2385 | |
2386 | /* |
2387 | * We could also check if the object is on the slabs freelist. |
2388 | * But this would be too expensive and it seems that the main |
2389 | * purpose of kmem_ptr_valid() is to check if the object belongs |
2390 | * to a certain slab. |
2391 | */ |
2392 | return 1; |
2393 | } |
2394 | EXPORT_SYMBOL(kmem_ptr_validate); |
2395 | |
2396 | /* |
2397 | * Determine the size of a slab object |
2398 | */ |
2399 | unsigned int kmem_cache_size(struct kmem_cache *s) |
2400 | { |
2401 | return s->objsize; |
2402 | } |
2403 | EXPORT_SYMBOL(kmem_cache_size); |
2404 | |
2405 | const char *kmem_cache_name(struct kmem_cache *s) |
2406 | { |
2407 | return s->name; |
2408 | } |
2409 | EXPORT_SYMBOL(kmem_cache_name); |
2410 | |
2411 | static void list_slab_objects(struct kmem_cache *s, struct page *page, |
2412 | const char *text) |
2413 | { |
2414 | #ifdef CONFIG_SLUB_DEBUG |
2415 | void *addr = page_address(page); |
2416 | void *p; |
2417 | long *map = kzalloc(BITS_TO_LONGS(page->objects) * sizeof(long), |
2418 | GFP_ATOMIC); |
2419 | |
2420 | if (!map) |
2421 | return; |
2422 | slab_err(s, page, "%s", text); |
2423 | slab_lock(page); |
2424 | for_each_free_object(p, s, page->freelist) |
2425 | set_bit(slab_index(p, s, addr), map); |
2426 | |
2427 | for_each_object(p, s, addr, page->objects) { |
2428 | |
2429 | if (!test_bit(slab_index(p, s, addr), map)) { |
2430 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n", |
2431 | p, p - addr); |
2432 | print_tracking(s, p); |
2433 | } |
2434 | } |
2435 | slab_unlock(page); |
2436 | kfree(map); |
2437 | #endif |
2438 | } |
2439 | |
2440 | /* |
2441 | * Attempt to free all partial slabs on a node. |
2442 | */ |
2443 | static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) |
2444 | { |
2445 | unsigned long flags; |
2446 | struct page *page, *h; |
2447 | |
2448 | spin_lock_irqsave(&n->list_lock, flags); |
2449 | list_for_each_entry_safe(page, h, &n->partial, lru) { |
2450 | if (!page->inuse) { |
2451 | list_del(&page->lru); |
2452 | discard_slab(s, page); |
2453 | n->nr_partial--; |
2454 | } else { |
2455 | list_slab_objects(s, page, |
2456 | "Objects remaining on kmem_cache_close()"); |
2457 | } |
2458 | } |
2459 | spin_unlock_irqrestore(&n->list_lock, flags); |
2460 | } |
2461 | |
2462 | /* |
2463 | * Release all resources used by a slab cache. |
2464 | */ |
2465 | static inline int kmem_cache_close(struct kmem_cache *s) |
2466 | { |
2467 | int node; |
2468 | |
2469 | flush_all(s); |
2470 | free_percpu(s->cpu_slab); |
2471 | /* Attempt to free all objects */ |
2472 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2473 | struct kmem_cache_node *n = get_node(s, node); |
2474 | |
2475 | free_partial(s, n); |
2476 | if (n->nr_partial || slabs_node(s, node)) |
2477 | return 1; |
2478 | } |
2479 | free_kmem_cache_nodes(s); |
2480 | return 0; |
2481 | } |
2482 | |
2483 | /* |
2484 | * Close a cache and release the kmem_cache structure |
2485 | * (must be used for caches created using kmem_cache_create) |
2486 | */ |
2487 | void kmem_cache_destroy(struct kmem_cache *s) |
2488 | { |
2489 | down_write(&slub_lock); |
2490 | s->refcount--; |
2491 | if (!s->refcount) { |
2492 | list_del(&s->list); |
2493 | if (kmem_cache_close(s)) { |
2494 | printk(KERN_ERR "SLUB %s: %s called for cache that " |
2495 | "still has objects.\n", s->name, __func__); |
2496 | dump_stack(); |
2497 | } |
2498 | if (s->flags & SLAB_DESTROY_BY_RCU) |
2499 | rcu_barrier(); |
2500 | sysfs_slab_remove(s); |
2501 | } |
2502 | up_write(&slub_lock); |
2503 | } |
2504 | EXPORT_SYMBOL(kmem_cache_destroy); |
2505 | |
2506 | /******************************************************************** |
2507 | * Kmalloc subsystem |
2508 | *******************************************************************/ |
2509 | |
2510 | struct kmem_cache kmalloc_caches[KMALLOC_CACHES] __cacheline_aligned; |
2511 | EXPORT_SYMBOL(kmalloc_caches); |
2512 | |
2513 | static int __init setup_slub_min_order(char *str) |
2514 | { |
2515 | get_option(&str, &slub_min_order); |
2516 | |
2517 | return 1; |
2518 | } |
2519 | |
2520 | __setup("slub_min_order=", setup_slub_min_order); |
2521 | |
2522 | static int __init setup_slub_max_order(char *str) |
2523 | { |
2524 | get_option(&str, &slub_max_order); |
2525 | slub_max_order = min(slub_max_order, MAX_ORDER - 1); |
2526 | |
2527 | return 1; |
2528 | } |
2529 | |
2530 | __setup("slub_max_order=", setup_slub_max_order); |
2531 | |
2532 | static int __init setup_slub_min_objects(char *str) |
2533 | { |
2534 | get_option(&str, &slub_min_objects); |
2535 | |
2536 | return 1; |
2537 | } |
2538 | |
2539 | __setup("slub_min_objects=", setup_slub_min_objects); |
2540 | |
2541 | static int __init setup_slub_nomerge(char *str) |
2542 | { |
2543 | slub_nomerge = 1; |
2544 | return 1; |
2545 | } |
2546 | |
2547 | __setup("slub_nomerge", setup_slub_nomerge); |
2548 | |
2549 | static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s, |
2550 | const char *name, int size, gfp_t gfp_flags) |
2551 | { |
2552 | unsigned int flags = 0; |
2553 | |
2554 | if (gfp_flags & SLUB_DMA) |
2555 | flags = SLAB_CACHE_DMA; |
2556 | |
2557 | /* |
2558 | * This function is called with IRQs disabled during early-boot on |
2559 | * single CPU so there's no need to take slub_lock here. |
2560 | */ |
2561 | if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN, |
2562 | flags, NULL)) |
2563 | goto panic; |
2564 | |
2565 | list_add(&s->list, &slab_caches); |
2566 | |
2567 | if (sysfs_slab_add(s)) |
2568 | goto panic; |
2569 | return s; |
2570 | |
2571 | panic: |
2572 | panic("Creation of kmalloc slab %s size=%d failed.\n", name, size); |
2573 | } |
2574 | |
2575 | #ifdef CONFIG_ZONE_DMA |
2576 | static struct kmem_cache *kmalloc_caches_dma[SLUB_PAGE_SHIFT]; |
2577 | |
2578 | static void sysfs_add_func(struct work_struct *w) |
2579 | { |
2580 | struct kmem_cache *s; |
2581 | |
2582 | down_write(&slub_lock); |
2583 | list_for_each_entry(s, &slab_caches, list) { |
2584 | if (s->flags & __SYSFS_ADD_DEFERRED) { |
2585 | s->flags &= ~__SYSFS_ADD_DEFERRED; |
2586 | sysfs_slab_add(s); |
2587 | } |
2588 | } |
2589 | up_write(&slub_lock); |
2590 | } |
2591 | |
2592 | static DECLARE_WORK(sysfs_add_work, sysfs_add_func); |
2593 | |
2594 | static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags) |
2595 | { |
2596 | struct kmem_cache *s; |
2597 | char *text; |
2598 | size_t realsize; |
2599 | unsigned long slabflags; |
2600 | int i; |
2601 | |
2602 | s = kmalloc_caches_dma[index]; |
2603 | if (s) |
2604 | return s; |
2605 | |
2606 | /* Dynamically create dma cache */ |
2607 | if (flags & __GFP_WAIT) |
2608 | down_write(&slub_lock); |
2609 | else { |
2610 | if (!down_write_trylock(&slub_lock)) |
2611 | goto out; |
2612 | } |
2613 | |
2614 | if (kmalloc_caches_dma[index]) |
2615 | goto unlock_out; |
2616 | |
2617 | realsize = kmalloc_caches[index].objsize; |
2618 | text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d", |
2619 | (unsigned int)realsize); |
2620 | |
2621 | s = NULL; |
2622 | for (i = 0; i < KMALLOC_CACHES; i++) |
2623 | if (!kmalloc_caches[i].size) |
2624 | break; |
2625 | |
2626 | BUG_ON(i >= KMALLOC_CACHES); |
2627 | s = kmalloc_caches + i; |
2628 | |
2629 | /* |
2630 | * Must defer sysfs creation to a workqueue because we don't know |
2631 | * what context we are called from. Before sysfs comes up, we don't |
2632 | * need to do anything because our sysfs initcall will start by |
2633 | * adding all existing slabs to sysfs. |
2634 | */ |
2635 | slabflags = SLAB_CACHE_DMA|SLAB_NOTRACK; |
2636 | if (slab_state >= SYSFS) |
2637 | slabflags |= __SYSFS_ADD_DEFERRED; |
2638 | |
2639 | if (!text || !kmem_cache_open(s, flags, text, |
2640 | realsize, ARCH_KMALLOC_MINALIGN, slabflags, NULL)) { |
2641 | s->size = 0; |
2642 | kfree(text); |
2643 | goto unlock_out; |
2644 | } |
2645 | |
2646 | list_add(&s->list, &slab_caches); |
2647 | kmalloc_caches_dma[index] = s; |
2648 | |
2649 | if (slab_state >= SYSFS) |
2650 | schedule_work(&sysfs_add_work); |
2651 | |
2652 | unlock_out: |
2653 | up_write(&slub_lock); |
2654 | out: |
2655 | return kmalloc_caches_dma[index]; |
2656 | } |
2657 | #endif |
2658 | |
2659 | /* |
2660 | * Conversion table for small slabs sizes / 8 to the index in the |
2661 | * kmalloc array. This is necessary for slabs < 192 since we have non power |
2662 | * of two cache sizes there. The size of larger slabs can be determined using |
2663 | * fls. |
2664 | */ |
2665 | static s8 size_index[24] = { |
2666 | 3, /* 8 */ |
2667 | 4, /* 16 */ |
2668 | 5, /* 24 */ |
2669 | 5, /* 32 */ |
2670 | 6, /* 40 */ |
2671 | 6, /* 48 */ |
2672 | 6, /* 56 */ |
2673 | 6, /* 64 */ |
2674 | 1, /* 72 */ |
2675 | 1, /* 80 */ |
2676 | 1, /* 88 */ |
2677 | 1, /* 96 */ |
2678 | 7, /* 104 */ |
2679 | 7, /* 112 */ |
2680 | 7, /* 120 */ |
2681 | 7, /* 128 */ |
2682 | 2, /* 136 */ |
2683 | 2, /* 144 */ |
2684 | 2, /* 152 */ |
2685 | 2, /* 160 */ |
2686 | 2, /* 168 */ |
2687 | 2, /* 176 */ |
2688 | 2, /* 184 */ |
2689 | 2 /* 192 */ |
2690 | }; |
2691 | |
2692 | static inline int size_index_elem(size_t bytes) |
2693 | { |
2694 | return (bytes - 1) / 8; |
2695 | } |
2696 | |
2697 | static struct kmem_cache *get_slab(size_t size, gfp_t flags) |
2698 | { |
2699 | int index; |
2700 | |
2701 | if (size <= 192) { |
2702 | if (!size) |
2703 | return ZERO_SIZE_PTR; |
2704 | |
2705 | index = size_index[size_index_elem(size)]; |
2706 | } else |
2707 | index = fls(size - 1); |
2708 | |
2709 | #ifdef CONFIG_ZONE_DMA |
2710 | if (unlikely((flags & SLUB_DMA))) |
2711 | return dma_kmalloc_cache(index, flags); |
2712 | |
2713 | #endif |
2714 | return &kmalloc_caches[index]; |
2715 | } |
2716 | |
2717 | void *__kmalloc(size_t size, gfp_t flags) |
2718 | { |
2719 | struct kmem_cache *s; |
2720 | void *ret; |
2721 | |
2722 | if (unlikely(size > SLUB_MAX_SIZE)) |
2723 | return kmalloc_large(size, flags); |
2724 | |
2725 | s = get_slab(size, flags); |
2726 | |
2727 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
2728 | return s; |
2729 | |
2730 | ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_); |
2731 | |
2732 | trace_kmalloc(_RET_IP_, ret, size, s->size, flags); |
2733 | |
2734 | return ret; |
2735 | } |
2736 | EXPORT_SYMBOL(__kmalloc); |
2737 | |
2738 | static void *kmalloc_large_node(size_t size, gfp_t flags, int node) |
2739 | { |
2740 | struct page *page; |
2741 | void *ptr = NULL; |
2742 | |
2743 | flags |= __GFP_COMP | __GFP_NOTRACK; |
2744 | page = alloc_pages_node(node, flags, get_order(size)); |
2745 | if (page) |
2746 | ptr = page_address(page); |
2747 | |
2748 | kmemleak_alloc(ptr, size, 1, flags); |
2749 | return ptr; |
2750 | } |
2751 | |
2752 | #ifdef CONFIG_NUMA |
2753 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
2754 | { |
2755 | struct kmem_cache *s; |
2756 | void *ret; |
2757 | |
2758 | if (unlikely(size > SLUB_MAX_SIZE)) { |
2759 | ret = kmalloc_large_node(size, flags, node); |
2760 | |
2761 | trace_kmalloc_node(_RET_IP_, ret, |
2762 | size, PAGE_SIZE << get_order(size), |
2763 | flags, node); |
2764 | |
2765 | return ret; |
2766 | } |
2767 | |
2768 | s = get_slab(size, flags); |
2769 | |
2770 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
2771 | return s; |
2772 | |
2773 | ret = slab_alloc(s, flags, node, _RET_IP_); |
2774 | |
2775 | trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node); |
2776 | |
2777 | return ret; |
2778 | } |
2779 | EXPORT_SYMBOL(__kmalloc_node); |
2780 | #endif |
2781 | |
2782 | size_t ksize(const void *object) |
2783 | { |
2784 | struct page *page; |
2785 | struct kmem_cache *s; |
2786 | |
2787 | if (unlikely(object == ZERO_SIZE_PTR)) |
2788 | return 0; |
2789 | |
2790 | page = virt_to_head_page(object); |
2791 | |
2792 | if (unlikely(!PageSlab(page))) { |
2793 | WARN_ON(!PageCompound(page)); |
2794 | return PAGE_SIZE << compound_order(page); |
2795 | } |
2796 | s = page->slab; |
2797 | |
2798 | #ifdef CONFIG_SLUB_DEBUG |
2799 | /* |
2800 | * Debugging requires use of the padding between object |
2801 | * and whatever may come after it. |
2802 | */ |
2803 | if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) |
2804 | return s->objsize; |
2805 | |
2806 | #endif |
2807 | /* |
2808 | * If we have the need to store the freelist pointer |
2809 | * back there or track user information then we can |
2810 | * only use the space before that information. |
2811 | */ |
2812 | if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) |
2813 | return s->inuse; |
2814 | /* |
2815 | * Else we can use all the padding etc for the allocation |
2816 | */ |
2817 | return s->size; |
2818 | } |
2819 | EXPORT_SYMBOL(ksize); |
2820 | |
2821 | void kfree(const void *x) |
2822 | { |
2823 | struct page *page; |
2824 | void *object = (void *)x; |
2825 | |
2826 | trace_kfree(_RET_IP_, x); |
2827 | |
2828 | if (unlikely(ZERO_OR_NULL_PTR(x))) |
2829 | return; |
2830 | |
2831 | page = virt_to_head_page(x); |
2832 | if (unlikely(!PageSlab(page))) { |
2833 | BUG_ON(!PageCompound(page)); |
2834 | kmemleak_free(x); |
2835 | put_page(page); |
2836 | return; |
2837 | } |
2838 | slab_free(page->slab, page, object, _RET_IP_); |
2839 | } |
2840 | EXPORT_SYMBOL(kfree); |
2841 | |
2842 | /* |
2843 | * kmem_cache_shrink removes empty slabs from the partial lists and sorts |
2844 | * the remaining slabs by the number of items in use. The slabs with the |
2845 | * most items in use come first. New allocations will then fill those up |
2846 | * and thus they can be removed from the partial lists. |
2847 | * |
2848 | * The slabs with the least items are placed last. This results in them |
2849 | * being allocated from last increasing the chance that the last objects |
2850 | * are freed in them. |
2851 | */ |
2852 | int kmem_cache_shrink(struct kmem_cache *s) |
2853 | { |
2854 | int node; |
2855 | int i; |
2856 | struct kmem_cache_node *n; |
2857 | struct page *page; |
2858 | struct page *t; |
2859 | int objects = oo_objects(s->max); |
2860 | struct list_head *slabs_by_inuse = |
2861 | kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL); |
2862 | unsigned long flags; |
2863 | |
2864 | if (!slabs_by_inuse) |
2865 | return -ENOMEM; |
2866 | |
2867 | flush_all(s); |
2868 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2869 | n = get_node(s, node); |
2870 | |
2871 | if (!n->nr_partial) |
2872 | continue; |
2873 | |
2874 | for (i = 0; i < objects; i++) |
2875 | INIT_LIST_HEAD(slabs_by_inuse + i); |
2876 | |
2877 | spin_lock_irqsave(&n->list_lock, flags); |
2878 | |
2879 | /* |
2880 | * Build lists indexed by the items in use in each slab. |
2881 | * |
2882 | * Note that concurrent frees may occur while we hold the |
2883 | * list_lock. page->inuse here is the upper limit. |
2884 | */ |
2885 | list_for_each_entry_safe(page, t, &n->partial, lru) { |
2886 | if (!page->inuse && slab_trylock(page)) { |
2887 | /* |
2888 | * Must hold slab lock here because slab_free |
2889 | * may have freed the last object and be |
2890 | * waiting to release the slab. |
2891 | */ |
2892 | list_del(&page->lru); |
2893 | n->nr_partial--; |
2894 | slab_unlock(page); |
2895 | discard_slab(s, page); |
2896 | } else { |
2897 | list_move(&page->lru, |
2898 | slabs_by_inuse + page->inuse); |
2899 | } |
2900 | } |
2901 | |
2902 | /* |
2903 | * Rebuild the partial list with the slabs filled up most |
2904 | * first and the least used slabs at the end. |
2905 | */ |
2906 | for (i = objects - 1; i >= 0; i--) |
2907 | list_splice(slabs_by_inuse + i, n->partial.prev); |
2908 | |
2909 | spin_unlock_irqrestore(&n->list_lock, flags); |
2910 | } |
2911 | |
2912 | kfree(slabs_by_inuse); |
2913 | return 0; |
2914 | } |
2915 | EXPORT_SYMBOL(kmem_cache_shrink); |
2916 | |
2917 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
2918 | static int slab_mem_going_offline_callback(void *arg) |
2919 | { |
2920 | struct kmem_cache *s; |
2921 | |
2922 | down_read(&slub_lock); |
2923 | list_for_each_entry(s, &slab_caches, list) |
2924 | kmem_cache_shrink(s); |
2925 | up_read(&slub_lock); |
2926 | |
2927 | return 0; |
2928 | } |
2929 | |
2930 | static void slab_mem_offline_callback(void *arg) |
2931 | { |
2932 | struct kmem_cache_node *n; |
2933 | struct kmem_cache *s; |
2934 | struct memory_notify *marg = arg; |
2935 | int offline_node; |
2936 | |
2937 | offline_node = marg->status_change_nid; |
2938 | |
2939 | /* |
2940 | * If the node still has available memory. we need kmem_cache_node |
2941 | * for it yet. |
2942 | */ |
2943 | if (offline_node < 0) |
2944 | return; |
2945 | |
2946 | down_read(&slub_lock); |
2947 | list_for_each_entry(s, &slab_caches, list) { |
2948 | n = get_node(s, offline_node); |
2949 | if (n) { |
2950 | /* |
2951 | * if n->nr_slabs > 0, slabs still exist on the node |
2952 | * that is going down. We were unable to free them, |
2953 | * and offline_pages() function shouldn't call this |
2954 | * callback. So, we must fail. |
2955 | */ |
2956 | BUG_ON(slabs_node(s, offline_node)); |
2957 | |
2958 | s->node[offline_node] = NULL; |
2959 | kmem_cache_free(kmalloc_caches, n); |
2960 | } |
2961 | } |
2962 | up_read(&slub_lock); |
2963 | } |
2964 | |
2965 | static int slab_mem_going_online_callback(void *arg) |
2966 | { |
2967 | struct kmem_cache_node *n; |
2968 | struct kmem_cache *s; |
2969 | struct memory_notify *marg = arg; |
2970 | int nid = marg->status_change_nid; |
2971 | int ret = 0; |
2972 | |
2973 | /* |
2974 | * If the node's memory is already available, then kmem_cache_node is |
2975 | * already created. Nothing to do. |
2976 | */ |
2977 | if (nid < 0) |
2978 | return 0; |
2979 | |
2980 | /* |
2981 | * We are bringing a node online. No memory is available yet. We must |
2982 | * allocate a kmem_cache_node structure in order to bring the node |
2983 | * online. |
2984 | */ |
2985 | down_read(&slub_lock); |
2986 | list_for_each_entry(s, &slab_caches, list) { |
2987 | /* |
2988 | * XXX: kmem_cache_alloc_node will fallback to other nodes |
2989 | * since memory is not yet available from the node that |
2990 | * is brought up. |
2991 | */ |
2992 | n = kmem_cache_alloc(kmalloc_caches, GFP_KERNEL); |
2993 | if (!n) { |
2994 | ret = -ENOMEM; |
2995 | goto out; |
2996 | } |
2997 | init_kmem_cache_node(n, s); |
2998 | s->node[nid] = n; |
2999 | } |
3000 | out: |
3001 | up_read(&slub_lock); |
3002 | return ret; |
3003 | } |
3004 | |
3005 | static int slab_memory_callback(struct notifier_block *self, |
3006 | unsigned long action, void *arg) |
3007 | { |
3008 | int ret = 0; |
3009 | |
3010 | switch (action) { |
3011 | case MEM_GOING_ONLINE: |
3012 | ret = slab_mem_going_online_callback(arg); |
3013 | break; |
3014 | case MEM_GOING_OFFLINE: |
3015 | ret = slab_mem_going_offline_callback(arg); |
3016 | break; |
3017 | case MEM_OFFLINE: |
3018 | case MEM_CANCEL_ONLINE: |
3019 | slab_mem_offline_callback(arg); |
3020 | break; |
3021 | case MEM_ONLINE: |
3022 | case MEM_CANCEL_OFFLINE: |
3023 | break; |
3024 | } |
3025 | if (ret) |
3026 | ret = notifier_from_errno(ret); |
3027 | else |
3028 | ret = NOTIFY_OK; |
3029 | return ret; |
3030 | } |
3031 | |
3032 | #endif /* CONFIG_MEMORY_HOTPLUG */ |
3033 | |
3034 | /******************************************************************** |
3035 | * Basic setup of slabs |
3036 | *******************************************************************/ |
3037 | |
3038 | void __init kmem_cache_init(void) |
3039 | { |
3040 | int i; |
3041 | int caches = 0; |
3042 | |
3043 | #ifdef CONFIG_NUMA |
3044 | /* |
3045 | * Must first have the slab cache available for the allocations of the |
3046 | * struct kmem_cache_node's. There is special bootstrap code in |
3047 | * kmem_cache_open for slab_state == DOWN. |
3048 | */ |
3049 | create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node", |
3050 | sizeof(struct kmem_cache_node), GFP_NOWAIT); |
3051 | kmalloc_caches[0].refcount = -1; |
3052 | caches++; |
3053 | |
3054 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
3055 | #endif |
3056 | |
3057 | /* Able to allocate the per node structures */ |
3058 | slab_state = PARTIAL; |
3059 | |
3060 | /* Caches that are not of the two-to-the-power-of size */ |
3061 | if (KMALLOC_MIN_SIZE <= 32) { |
3062 | create_kmalloc_cache(&kmalloc_caches[1], |
3063 | "kmalloc-96", 96, GFP_NOWAIT); |
3064 | caches++; |
3065 | } |
3066 | if (KMALLOC_MIN_SIZE <= 64) { |
3067 | create_kmalloc_cache(&kmalloc_caches[2], |
3068 | "kmalloc-192", 192, GFP_NOWAIT); |
3069 | caches++; |
3070 | } |
3071 | |
3072 | for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) { |
3073 | create_kmalloc_cache(&kmalloc_caches[i], |
3074 | "kmalloc", 1 << i, GFP_NOWAIT); |
3075 | caches++; |
3076 | } |
3077 | |
3078 | |
3079 | /* |
3080 | * Patch up the size_index table if we have strange large alignment |
3081 | * requirements for the kmalloc array. This is only the case for |
3082 | * MIPS it seems. The standard arches will not generate any code here. |
3083 | * |
3084 | * Largest permitted alignment is 256 bytes due to the way we |
3085 | * handle the index determination for the smaller caches. |
3086 | * |
3087 | * Make sure that nothing crazy happens if someone starts tinkering |
3088 | * around with ARCH_KMALLOC_MINALIGN |
3089 | */ |
3090 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || |
3091 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); |
3092 | |
3093 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { |
3094 | int elem = size_index_elem(i); |
3095 | if (elem >= ARRAY_SIZE(size_index)) |
3096 | break; |
3097 | size_index[elem] = KMALLOC_SHIFT_LOW; |
3098 | } |
3099 | |
3100 | if (KMALLOC_MIN_SIZE == 64) { |
3101 | /* |
3102 | * The 96 byte size cache is not used if the alignment |
3103 | * is 64 byte. |
3104 | */ |
3105 | for (i = 64 + 8; i <= 96; i += 8) |
3106 | size_index[size_index_elem(i)] = 7; |
3107 | } else if (KMALLOC_MIN_SIZE == 128) { |
3108 | /* |
3109 | * The 192 byte sized cache is not used if the alignment |
3110 | * is 128 byte. Redirect kmalloc to use the 256 byte cache |
3111 | * instead. |
3112 | */ |
3113 | for (i = 128 + 8; i <= 192; i += 8) |
3114 | size_index[size_index_elem(i)] = 8; |
3115 | } |
3116 | |
3117 | slab_state = UP; |
3118 | |
3119 | /* Provide the correct kmalloc names now that the caches are up */ |
3120 | for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) { |
3121 | char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i); |
3122 | |
3123 | BUG_ON(!s); |
3124 | kmalloc_caches[i].name = s; |
3125 | } |
3126 | |
3127 | #ifdef CONFIG_SMP |
3128 | register_cpu_notifier(&slab_notifier); |
3129 | #endif |
3130 | #ifdef CONFIG_NUMA |
3131 | kmem_size = offsetof(struct kmem_cache, node) + |
3132 | nr_node_ids * sizeof(struct kmem_cache_node *); |
3133 | #else |
3134 | kmem_size = sizeof(struct kmem_cache); |
3135 | #endif |
3136 | |
3137 | printk(KERN_INFO |
3138 | "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," |
3139 | " CPUs=%d, Nodes=%d\n", |
3140 | caches, cache_line_size(), |
3141 | slub_min_order, slub_max_order, slub_min_objects, |
3142 | nr_cpu_ids, nr_node_ids); |
3143 | } |
3144 | |
3145 | void __init kmem_cache_init_late(void) |
3146 | { |
3147 | } |
3148 | |
3149 | /* |
3150 | * Find a mergeable slab cache |
3151 | */ |
3152 | static int slab_unmergeable(struct kmem_cache *s) |
3153 | { |
3154 | if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) |
3155 | return 1; |
3156 | |
3157 | if (s->ctor) |
3158 | return 1; |
3159 | |
3160 | /* |
3161 | * We may have set a slab to be unmergeable during bootstrap. |
3162 | */ |
3163 | if (s->refcount < 0) |
3164 | return 1; |
3165 | |
3166 | return 0; |
3167 | } |
3168 | |
3169 | static struct kmem_cache *find_mergeable(size_t size, |
3170 | size_t align, unsigned long flags, const char *name, |
3171 | void (*ctor)(void *)) |
3172 | { |
3173 | struct kmem_cache *s; |
3174 | |
3175 | if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) |
3176 | return NULL; |
3177 | |
3178 | if (ctor) |
3179 | return NULL; |
3180 | |
3181 | size = ALIGN(size, sizeof(void *)); |
3182 | align = calculate_alignment(flags, align, size); |
3183 | size = ALIGN(size, align); |
3184 | flags = kmem_cache_flags(size, flags, name, NULL); |
3185 | |
3186 | list_for_each_entry(s, &slab_caches, list) { |
3187 | if (slab_unmergeable(s)) |
3188 | continue; |
3189 | |
3190 | if (size > s->size) |
3191 | continue; |
3192 | |
3193 | if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) |
3194 | continue; |
3195 | /* |
3196 | * Check if alignment is compatible. |
3197 | * Courtesy of Adrian Drzewiecki |
3198 | */ |
3199 | if ((s->size & ~(align - 1)) != s->size) |
3200 | continue; |
3201 | |
3202 | if (s->size - size >= sizeof(void *)) |
3203 | continue; |
3204 | |
3205 | return s; |
3206 | } |
3207 | return NULL; |
3208 | } |
3209 | |
3210 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, |
3211 | size_t align, unsigned long flags, void (*ctor)(void *)) |
3212 | { |
3213 | struct kmem_cache *s; |
3214 | |
3215 | if (WARN_ON(!name)) |
3216 | return NULL; |
3217 | |
3218 | down_write(&slub_lock); |
3219 | s = find_mergeable(size, align, flags, name, ctor); |
3220 | if (s) { |
3221 | s->refcount++; |
3222 | /* |
3223 | * Adjust the object sizes so that we clear |
3224 | * the complete object on kzalloc. |
3225 | */ |
3226 | s->objsize = max(s->objsize, (int)size); |
3227 | s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *))); |
3228 | |
3229 | if (sysfs_slab_alias(s, name)) { |
3230 | s->refcount--; |
3231 | goto err; |
3232 | } |
3233 | up_write(&slub_lock); |
3234 | return s; |
3235 | } |
3236 | |
3237 | s = kmalloc(kmem_size, GFP_KERNEL); |
3238 | if (s) { |
3239 | if (kmem_cache_open(s, GFP_KERNEL, name, |
3240 | size, align, flags, ctor)) { |
3241 | list_add(&s->list, &slab_caches); |
3242 | if (sysfs_slab_add(s)) { |
3243 | list_del(&s->list); |
3244 | kfree(s); |
3245 | goto err; |
3246 | } |
3247 | up_write(&slub_lock); |
3248 | return s; |
3249 | } |
3250 | kfree(s); |
3251 | } |
3252 | up_write(&slub_lock); |
3253 | |
3254 | err: |
3255 | if (flags & SLAB_PANIC) |
3256 | panic("Cannot create slabcache %s\n", name); |
3257 | else |
3258 | s = NULL; |
3259 | return s; |
3260 | } |
3261 | EXPORT_SYMBOL(kmem_cache_create); |
3262 | |
3263 | #ifdef CONFIG_SMP |
3264 | /* |
3265 | * Use the cpu notifier to insure that the cpu slabs are flushed when |
3266 | * necessary. |
3267 | */ |
3268 | static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb, |
3269 | unsigned long action, void *hcpu) |
3270 | { |
3271 | long cpu = (long)hcpu; |
3272 | struct kmem_cache *s; |
3273 | unsigned long flags; |
3274 | |
3275 | switch (action) { |
3276 | case CPU_UP_CANCELED: |
3277 | case CPU_UP_CANCELED_FROZEN: |
3278 | case CPU_DEAD: |
3279 | case CPU_DEAD_FROZEN: |
3280 | down_read(&slub_lock); |
3281 | list_for_each_entry(s, &slab_caches, list) { |
3282 | local_irq_save(flags); |
3283 | __flush_cpu_slab(s, cpu); |
3284 | local_irq_restore(flags); |
3285 | } |
3286 | up_read(&slub_lock); |
3287 | break; |
3288 | default: |
3289 | break; |
3290 | } |
3291 | return NOTIFY_OK; |
3292 | } |
3293 | |
3294 | static struct notifier_block __cpuinitdata slab_notifier = { |
3295 | .notifier_call = slab_cpuup_callback |
3296 | }; |
3297 | |
3298 | #endif |
3299 | |
3300 | void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller) |
3301 | { |
3302 | struct kmem_cache *s; |
3303 | void *ret; |
3304 | |
3305 | if (unlikely(size > SLUB_MAX_SIZE)) |
3306 | return kmalloc_large(size, gfpflags); |
3307 | |
3308 | s = get_slab(size, gfpflags); |
3309 | |
3310 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3311 | return s; |
3312 | |
3313 | ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller); |
3314 | |
3315 | /* Honor the call site pointer we recieved. */ |
3316 | trace_kmalloc(caller, ret, size, s->size, gfpflags); |
3317 | |
3318 | return ret; |
3319 | } |
3320 | |
3321 | void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, |
3322 | int node, unsigned long caller) |
3323 | { |
3324 | struct kmem_cache *s; |
3325 | void *ret; |
3326 | |
3327 | if (unlikely(size > SLUB_MAX_SIZE)) { |
3328 | ret = kmalloc_large_node(size, gfpflags, node); |
3329 | |
3330 | trace_kmalloc_node(caller, ret, |
3331 | size, PAGE_SIZE << get_order(size), |
3332 | gfpflags, node); |
3333 | |
3334 | return ret; |
3335 | } |
3336 | |
3337 | s = get_slab(size, gfpflags); |
3338 | |
3339 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3340 | return s; |
3341 | |
3342 | ret = slab_alloc(s, gfpflags, node, caller); |
3343 | |
3344 | /* Honor the call site pointer we recieved. */ |
3345 | trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node); |
3346 | |
3347 | return ret; |
3348 | } |
3349 | |
3350 | #ifdef CONFIG_SLUB_DEBUG |
3351 | static int count_inuse(struct page *page) |
3352 | { |
3353 | return page->inuse; |
3354 | } |
3355 | |
3356 | static int count_total(struct page *page) |
3357 | { |
3358 | return page->objects; |
3359 | } |
3360 | |
3361 | static int validate_slab(struct kmem_cache *s, struct page *page, |
3362 | unsigned long *map) |
3363 | { |
3364 | void *p; |
3365 | void *addr = page_address(page); |
3366 | |
3367 | if (!check_slab(s, page) || |
3368 | !on_freelist(s, page, NULL)) |
3369 | return 0; |
3370 | |
3371 | /* Now we know that a valid freelist exists */ |
3372 | bitmap_zero(map, page->objects); |
3373 | |
3374 | for_each_free_object(p, s, page->freelist) { |
3375 | set_bit(slab_index(p, s, addr), map); |
3376 | if (!check_object(s, page, p, 0)) |
3377 | return 0; |
3378 | } |
3379 | |
3380 | for_each_object(p, s, addr, page->objects) |
3381 | if (!test_bit(slab_index(p, s, addr), map)) |
3382 | if (!check_object(s, page, p, 1)) |
3383 | return 0; |
3384 | return 1; |
3385 | } |
3386 | |
3387 | static void validate_slab_slab(struct kmem_cache *s, struct page *page, |
3388 | unsigned long *map) |
3389 | { |
3390 | if (slab_trylock(page)) { |
3391 | validate_slab(s, page, map); |
3392 | slab_unlock(page); |
3393 | } else |
3394 | printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n", |
3395 | s->name, page); |
3396 | } |
3397 | |
3398 | static int validate_slab_node(struct kmem_cache *s, |
3399 | struct kmem_cache_node *n, unsigned long *map) |
3400 | { |
3401 | unsigned long count = 0; |
3402 | struct page *page; |
3403 | unsigned long flags; |
3404 | |
3405 | spin_lock_irqsave(&n->list_lock, flags); |
3406 | |
3407 | list_for_each_entry(page, &n->partial, lru) { |
3408 | validate_slab_slab(s, page, map); |
3409 | count++; |
3410 | } |
3411 | if (count != n->nr_partial) |
3412 | printk(KERN_ERR "SLUB %s: %ld partial slabs counted but " |
3413 | "counter=%ld\n", s->name, count, n->nr_partial); |
3414 | |
3415 | if (!(s->flags & SLAB_STORE_USER)) |
3416 | goto out; |
3417 | |
3418 | list_for_each_entry(page, &n->full, lru) { |
3419 | validate_slab_slab(s, page, map); |
3420 | count++; |
3421 | } |
3422 | if (count != atomic_long_read(&n->nr_slabs)) |
3423 | printk(KERN_ERR "SLUB: %s %ld slabs counted but " |
3424 | "counter=%ld\n", s->name, count, |
3425 | atomic_long_read(&n->nr_slabs)); |
3426 | |
3427 | out: |
3428 | spin_unlock_irqrestore(&n->list_lock, flags); |
3429 | return count; |
3430 | } |
3431 | |
3432 | static long validate_slab_cache(struct kmem_cache *s) |
3433 | { |
3434 | int node; |
3435 | unsigned long count = 0; |
3436 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * |
3437 | sizeof(unsigned long), GFP_KERNEL); |
3438 | |
3439 | if (!map) |
3440 | return -ENOMEM; |
3441 | |
3442 | flush_all(s); |
3443 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3444 | struct kmem_cache_node *n = get_node(s, node); |
3445 | |
3446 | count += validate_slab_node(s, n, map); |
3447 | } |
3448 | kfree(map); |
3449 | return count; |
3450 | } |
3451 | |
3452 | #ifdef SLUB_RESILIENCY_TEST |
3453 | static void resiliency_test(void) |
3454 | { |
3455 | u8 *p; |
3456 | |
3457 | printk(KERN_ERR "SLUB resiliency testing\n"); |
3458 | printk(KERN_ERR "-----------------------\n"); |
3459 | printk(KERN_ERR "A. Corruption after allocation\n"); |
3460 | |
3461 | p = kzalloc(16, GFP_KERNEL); |
3462 | p[16] = 0x12; |
3463 | printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer" |
3464 | " 0x12->0x%p\n\n", p + 16); |
3465 | |
3466 | validate_slab_cache(kmalloc_caches + 4); |
3467 | |
3468 | /* Hmmm... The next two are dangerous */ |
3469 | p = kzalloc(32, GFP_KERNEL); |
3470 | p[32 + sizeof(void *)] = 0x34; |
3471 | printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab" |
3472 | " 0x34 -> -0x%p\n", p); |
3473 | printk(KERN_ERR |
3474 | "If allocated object is overwritten then not detectable\n\n"); |
3475 | |
3476 | validate_slab_cache(kmalloc_caches + 5); |
3477 | p = kzalloc(64, GFP_KERNEL); |
3478 | p += 64 + (get_cycles() & 0xff) * sizeof(void *); |
3479 | *p = 0x56; |
3480 | printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n", |
3481 | p); |
3482 | printk(KERN_ERR |
3483 | "If allocated object is overwritten then not detectable\n\n"); |
3484 | validate_slab_cache(kmalloc_caches + 6); |
3485 | |
3486 | printk(KERN_ERR "\nB. Corruption after free\n"); |
3487 | p = kzalloc(128, GFP_KERNEL); |
3488 | kfree(p); |
3489 | *p = 0x78; |
3490 | printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p); |
3491 | validate_slab_cache(kmalloc_caches + 7); |
3492 | |
3493 | p = kzalloc(256, GFP_KERNEL); |
3494 | kfree(p); |
3495 | p[50] = 0x9a; |
3496 | printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", |
3497 | p); |
3498 | validate_slab_cache(kmalloc_caches + 8); |
3499 | |
3500 | p = kzalloc(512, GFP_KERNEL); |
3501 | kfree(p); |
3502 | p[512] = 0xab; |
3503 | printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p); |
3504 | validate_slab_cache(kmalloc_caches + 9); |
3505 | } |
3506 | #else |
3507 | static void resiliency_test(void) {}; |
3508 | #endif |
3509 | |
3510 | /* |
3511 | * Generate lists of code addresses where slabcache objects are allocated |
3512 | * and freed. |
3513 | */ |
3514 | |
3515 | struct location { |
3516 | unsigned long count; |
3517 | unsigned long addr; |
3518 | long long sum_time; |
3519 | long min_time; |
3520 | long max_time; |
3521 | long min_pid; |
3522 | long max_pid; |
3523 | DECLARE_BITMAP(cpus, NR_CPUS); |
3524 | nodemask_t nodes; |
3525 | }; |
3526 | |
3527 | struct loc_track { |
3528 | unsigned long max; |
3529 | unsigned long count; |
3530 | struct location *loc; |
3531 | }; |
3532 | |
3533 | static void free_loc_track(struct loc_track *t) |
3534 | { |
3535 | if (t->max) |
3536 | free_pages((unsigned long)t->loc, |
3537 | get_order(sizeof(struct location) * t->max)); |
3538 | } |
3539 | |
3540 | static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags) |
3541 | { |
3542 | struct location *l; |
3543 | int order; |
3544 | |
3545 | order = get_order(sizeof(struct location) * max); |
3546 | |
3547 | l = (void *)__get_free_pages(flags, order); |
3548 | if (!l) |
3549 | return 0; |
3550 | |
3551 | if (t->count) { |
3552 | memcpy(l, t->loc, sizeof(struct location) * t->count); |
3553 | free_loc_track(t); |
3554 | } |
3555 | t->max = max; |
3556 | t->loc = l; |
3557 | return 1; |
3558 | } |
3559 | |
3560 | static int add_location(struct loc_track *t, struct kmem_cache *s, |
3561 | const struct track *track) |
3562 | { |
3563 | long start, end, pos; |
3564 | struct location *l; |
3565 | unsigned long caddr; |
3566 | unsigned long age = jiffies - track->when; |
3567 | |
3568 | start = -1; |
3569 | end = t->count; |
3570 | |
3571 | for ( ; ; ) { |
3572 | pos = start + (end - start + 1) / 2; |
3573 | |
3574 | /* |
3575 | * There is nothing at "end". If we end up there |
3576 | * we need to add something to before end. |
3577 | */ |
3578 | if (pos == end) |
3579 | break; |
3580 | |
3581 | caddr = t->loc[pos].addr; |
3582 | if (track->addr == caddr) { |
3583 | |
3584 | l = &t->loc[pos]; |
3585 | l->count++; |
3586 | if (track->when) { |
3587 | l->sum_time += age; |
3588 | if (age < l->min_time) |
3589 | l->min_time = age; |
3590 | if (age > l->max_time) |
3591 | l->max_time = age; |
3592 | |
3593 | if (track->pid < l->min_pid) |
3594 | l->min_pid = track->pid; |
3595 | if (track->pid > l->max_pid) |
3596 | l->max_pid = track->pid; |
3597 | |
3598 | cpumask_set_cpu(track->cpu, |
3599 | to_cpumask(l->cpus)); |
3600 | } |
3601 | node_set(page_to_nid(virt_to_page(track)), l->nodes); |
3602 | return 1; |
3603 | } |
3604 | |
3605 | if (track->addr < caddr) |
3606 | end = pos; |
3607 | else |
3608 | start = pos; |
3609 | } |
3610 | |
3611 | /* |
3612 | * Not found. Insert new tracking element. |
3613 | */ |
3614 | if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC)) |
3615 | return 0; |
3616 | |
3617 | l = t->loc + pos; |
3618 | if (pos < t->count) |
3619 | memmove(l + 1, l, |
3620 | (t->count - pos) * sizeof(struct location)); |
3621 | t->count++; |
3622 | l->count = 1; |
3623 | l->addr = track->addr; |
3624 | l->sum_time = age; |
3625 | l->min_time = age; |
3626 | l->max_time = age; |
3627 | l->min_pid = track->pid; |
3628 | l->max_pid = track->pid; |
3629 | cpumask_clear(to_cpumask(l->cpus)); |
3630 | cpumask_set_cpu(track->cpu, to_cpumask(l->cpus)); |
3631 | nodes_clear(l->nodes); |
3632 | node_set(page_to_nid(virt_to_page(track)), l->nodes); |
3633 | return 1; |
3634 | } |
3635 | |
3636 | static void process_slab(struct loc_track *t, struct kmem_cache *s, |
3637 | struct page *page, enum track_item alloc, |
3638 | long *map) |
3639 | { |
3640 | void *addr = page_address(page); |
3641 | void *p; |
3642 | |
3643 | bitmap_zero(map, page->objects); |
3644 | for_each_free_object(p, s, page->freelist) |
3645 | set_bit(slab_index(p, s, addr), map); |
3646 | |
3647 | for_each_object(p, s, addr, page->objects) |
3648 | if (!test_bit(slab_index(p, s, addr), map)) |
3649 | add_location(t, s, get_track(s, p, alloc)); |
3650 | } |
3651 | |
3652 | static int list_locations(struct kmem_cache *s, char *buf, |
3653 | enum track_item alloc) |
3654 | { |
3655 | int len = 0; |
3656 | unsigned long i; |
3657 | struct loc_track t = { 0, 0, NULL }; |
3658 | int node; |
3659 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * |
3660 | sizeof(unsigned long), GFP_KERNEL); |
3661 | |
3662 | if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), |
3663 | GFP_TEMPORARY)) { |
3664 | kfree(map); |
3665 | return sprintf(buf, "Out of memory\n"); |
3666 | } |
3667 | /* Push back cpu slabs */ |
3668 | flush_all(s); |
3669 | |
3670 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3671 | struct kmem_cache_node *n = get_node(s, node); |
3672 | unsigned long flags; |
3673 | struct page *page; |
3674 | |
3675 | if (!atomic_long_read(&n->nr_slabs)) |
3676 | continue; |
3677 | |
3678 | spin_lock_irqsave(&n->list_lock, flags); |
3679 | list_for_each_entry(page, &n->partial, lru) |
3680 | process_slab(&t, s, page, alloc, map); |
3681 | list_for_each_entry(page, &n->full, lru) |
3682 | process_slab(&t, s, page, alloc, map); |
3683 | spin_unlock_irqrestore(&n->list_lock, flags); |
3684 | } |
3685 | |
3686 | for (i = 0; i < t.count; i++) { |
3687 | struct location *l = &t.loc[i]; |
3688 | |
3689 | if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100) |
3690 | break; |
3691 | len += sprintf(buf + len, "%7ld ", l->count); |
3692 | |
3693 | if (l->addr) |
3694 | len += sprint_symbol(buf + len, (unsigned long)l->addr); |
3695 | else |
3696 | len += sprintf(buf + len, "<not-available>"); |
3697 | |
3698 | if (l->sum_time != l->min_time) { |
3699 | len += sprintf(buf + len, " age=%ld/%ld/%ld", |
3700 | l->min_time, |
3701 | (long)div_u64(l->sum_time, l->count), |
3702 | l->max_time); |
3703 | } else |
3704 | len += sprintf(buf + len, " age=%ld", |
3705 | l->min_time); |
3706 | |
3707 | if (l->min_pid != l->max_pid) |
3708 | len += sprintf(buf + len, " pid=%ld-%ld", |
3709 | l->min_pid, l->max_pid); |
3710 | else |
3711 | len += sprintf(buf + len, " pid=%ld", |
3712 | l->min_pid); |
3713 | |
3714 | if (num_online_cpus() > 1 && |
3715 | !cpumask_empty(to_cpumask(l->cpus)) && |
3716 | len < PAGE_SIZE - 60) { |
3717 | len += sprintf(buf + len, " cpus="); |
3718 | len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50, |
3719 | to_cpumask(l->cpus)); |
3720 | } |
3721 | |
3722 | if (nr_online_nodes > 1 && !nodes_empty(l->nodes) && |
3723 | len < PAGE_SIZE - 60) { |
3724 | len += sprintf(buf + len, " nodes="); |
3725 | len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50, |
3726 | l->nodes); |
3727 | } |
3728 | |
3729 | len += sprintf(buf + len, "\n"); |
3730 | } |
3731 | |
3732 | free_loc_track(&t); |
3733 | kfree(map); |
3734 | if (!t.count) |
3735 | len += sprintf(buf, "No data\n"); |
3736 | return len; |
3737 | } |
3738 | |
3739 | enum slab_stat_type { |
3740 | SL_ALL, /* All slabs */ |
3741 | SL_PARTIAL, /* Only partially allocated slabs */ |
3742 | SL_CPU, /* Only slabs used for cpu caches */ |
3743 | SL_OBJECTS, /* Determine allocated objects not slabs */ |
3744 | SL_TOTAL /* Determine object capacity not slabs */ |
3745 | }; |
3746 | |
3747 | #define SO_ALL (1 << SL_ALL) |
3748 | #define SO_PARTIAL (1 << SL_PARTIAL) |
3749 | #define SO_CPU (1 << SL_CPU) |
3750 | #define SO_OBJECTS (1 << SL_OBJECTS) |
3751 | #define SO_TOTAL (1 << SL_TOTAL) |
3752 | |
3753 | static ssize_t show_slab_objects(struct kmem_cache *s, |
3754 | char *buf, unsigned long flags) |
3755 | { |
3756 | unsigned long total = 0; |
3757 | int node; |
3758 | int x; |
3759 | unsigned long *nodes; |
3760 | unsigned long *per_cpu; |
3761 | |
3762 | nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); |
3763 | if (!nodes) |
3764 | return -ENOMEM; |
3765 | per_cpu = nodes + nr_node_ids; |
3766 | |
3767 | if (flags & SO_CPU) { |
3768 | int cpu; |
3769 | |
3770 | for_each_possible_cpu(cpu) { |
3771 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); |
3772 | |
3773 | if (!c || c->node < 0) |
3774 | continue; |
3775 | |
3776 | if (c->page) { |
3777 | if (flags & SO_TOTAL) |
3778 | x = c->page->objects; |
3779 | else if (flags & SO_OBJECTS) |
3780 | x = c->page->inuse; |
3781 | else |
3782 | x = 1; |
3783 | |
3784 | total += x; |
3785 | nodes[c->node] += x; |
3786 | } |
3787 | per_cpu[c->node]++; |
3788 | } |
3789 | } |
3790 | |
3791 | if (flags & SO_ALL) { |
3792 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3793 | struct kmem_cache_node *n = get_node(s, node); |
3794 | |
3795 | if (flags & SO_TOTAL) |
3796 | x = atomic_long_read(&n->total_objects); |
3797 | else if (flags & SO_OBJECTS) |
3798 | x = atomic_long_read(&n->total_objects) - |
3799 | count_partial(n, count_free); |
3800 | |
3801 | else |
3802 | x = atomic_long_read(&n->nr_slabs); |
3803 | total += x; |
3804 | nodes[node] += x; |
3805 | } |
3806 | |
3807 | } else if (flags & SO_PARTIAL) { |
3808 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3809 | struct kmem_cache_node *n = get_node(s, node); |
3810 | |
3811 | if (flags & SO_TOTAL) |
3812 | x = count_partial(n, count_total); |
3813 | else if (flags & SO_OBJECTS) |
3814 | x = count_partial(n, count_inuse); |
3815 | else |
3816 | x = n->nr_partial; |
3817 | total += x; |
3818 | nodes[node] += x; |
3819 | } |
3820 | } |
3821 | x = sprintf(buf, "%lu", total); |
3822 | #ifdef CONFIG_NUMA |
3823 | for_each_node_state(node, N_NORMAL_MEMORY) |
3824 | if (nodes[node]) |
3825 | x += sprintf(buf + x, " N%d=%lu", |
3826 | node, nodes[node]); |
3827 | #endif |
3828 | kfree(nodes); |
3829 | return x + sprintf(buf + x, "\n"); |
3830 | } |
3831 | |
3832 | static int any_slab_objects(struct kmem_cache *s) |
3833 | { |
3834 | int node; |
3835 | |
3836 | for_each_online_node(node) { |
3837 | struct kmem_cache_node *n = get_node(s, node); |
3838 | |
3839 | if (!n) |
3840 | continue; |
3841 | |
3842 | if (atomic_long_read(&n->total_objects)) |
3843 | return 1; |
3844 | } |
3845 | return 0; |
3846 | } |
3847 | |
3848 | #define to_slab_attr(n) container_of(n, struct slab_attribute, attr) |
3849 | #define to_slab(n) container_of(n, struct kmem_cache, kobj); |
3850 | |
3851 | struct slab_attribute { |
3852 | struct attribute attr; |
3853 | ssize_t (*show)(struct kmem_cache *s, char *buf); |
3854 | ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); |
3855 | }; |
3856 | |
3857 | #define SLAB_ATTR_RO(_name) \ |
3858 | static struct slab_attribute _name##_attr = __ATTR_RO(_name) |
3859 | |
3860 | #define SLAB_ATTR(_name) \ |
3861 | static struct slab_attribute _name##_attr = \ |
3862 | __ATTR(_name, 0644, _name##_show, _name##_store) |
3863 | |
3864 | static ssize_t slab_size_show(struct kmem_cache *s, char *buf) |
3865 | { |
3866 | return sprintf(buf, "%d\n", s->size); |
3867 | } |
3868 | SLAB_ATTR_RO(slab_size); |
3869 | |
3870 | static ssize_t align_show(struct kmem_cache *s, char *buf) |
3871 | { |
3872 | return sprintf(buf, "%d\n", s->align); |
3873 | } |
3874 | SLAB_ATTR_RO(align); |
3875 | |
3876 | static ssize_t object_size_show(struct kmem_cache *s, char *buf) |
3877 | { |
3878 | return sprintf(buf, "%d\n", s->objsize); |
3879 | } |
3880 | SLAB_ATTR_RO(object_size); |
3881 | |
3882 | static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf) |
3883 | { |
3884 | return sprintf(buf, "%d\n", oo_objects(s->oo)); |
3885 | } |
3886 | SLAB_ATTR_RO(objs_per_slab); |
3887 | |
3888 | static ssize_t order_store(struct kmem_cache *s, |
3889 | const char *buf, size_t length) |
3890 | { |
3891 | unsigned long order; |
3892 | int err; |
3893 | |
3894 | err = strict_strtoul(buf, 10, &order); |
3895 | if (err) |
3896 | return err; |
3897 | |
3898 | if (order > slub_max_order || order < slub_min_order) |
3899 | return -EINVAL; |
3900 | |
3901 | calculate_sizes(s, order); |
3902 | return length; |
3903 | } |
3904 | |
3905 | static ssize_t order_show(struct kmem_cache *s, char *buf) |
3906 | { |
3907 | return sprintf(buf, "%d\n", oo_order(s->oo)); |
3908 | } |
3909 | SLAB_ATTR(order); |
3910 | |
3911 | static ssize_t min_partial_show(struct kmem_cache *s, char *buf) |
3912 | { |
3913 | return sprintf(buf, "%lu\n", s->min_partial); |
3914 | } |
3915 | |
3916 | static ssize_t min_partial_store(struct kmem_cache *s, const char *buf, |
3917 | size_t length) |
3918 | { |
3919 | unsigned long min; |
3920 | int err; |
3921 | |
3922 | err = strict_strtoul(buf, 10, &min); |
3923 | if (err) |
3924 | return err; |
3925 | |
3926 | set_min_partial(s, min); |
3927 | return length; |
3928 | } |
3929 | SLAB_ATTR(min_partial); |
3930 | |
3931 | static ssize_t ctor_show(struct kmem_cache *s, char *buf) |
3932 | { |
3933 | if (s->ctor) { |
3934 | int n = sprint_symbol(buf, (unsigned long)s->ctor); |
3935 | |
3936 | return n + sprintf(buf + n, "\n"); |
3937 | } |
3938 | return 0; |
3939 | } |
3940 | SLAB_ATTR_RO(ctor); |
3941 | |
3942 | static ssize_t aliases_show(struct kmem_cache *s, char *buf) |
3943 | { |
3944 | return sprintf(buf, "%d\n", s->refcount - 1); |
3945 | } |
3946 | SLAB_ATTR_RO(aliases); |
3947 | |
3948 | static ssize_t slabs_show(struct kmem_cache *s, char *buf) |
3949 | { |
3950 | return show_slab_objects(s, buf, SO_ALL); |
3951 | } |
3952 | SLAB_ATTR_RO(slabs); |
3953 | |
3954 | static ssize_t partial_show(struct kmem_cache *s, char *buf) |
3955 | { |
3956 | return show_slab_objects(s, buf, SO_PARTIAL); |
3957 | } |
3958 | SLAB_ATTR_RO(partial); |
3959 | |
3960 | static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) |
3961 | { |
3962 | return show_slab_objects(s, buf, SO_CPU); |
3963 | } |
3964 | SLAB_ATTR_RO(cpu_slabs); |
3965 | |
3966 | static ssize_t objects_show(struct kmem_cache *s, char *buf) |
3967 | { |
3968 | return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS); |
3969 | } |
3970 | SLAB_ATTR_RO(objects); |
3971 | |
3972 | static ssize_t objects_partial_show(struct kmem_cache *s, char *buf) |
3973 | { |
3974 | return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS); |
3975 | } |
3976 | SLAB_ATTR_RO(objects_partial); |
3977 | |
3978 | static ssize_t total_objects_show(struct kmem_cache *s, char *buf) |
3979 | { |
3980 | return show_slab_objects(s, buf, SO_ALL|SO_TOTAL); |
3981 | } |
3982 | SLAB_ATTR_RO(total_objects); |
3983 | |
3984 | static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf) |
3985 | { |
3986 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE)); |
3987 | } |
3988 | |
3989 | static ssize_t sanity_checks_store(struct kmem_cache *s, |
3990 | const char *buf, size_t length) |
3991 | { |
3992 | s->flags &= ~SLAB_DEBUG_FREE; |
3993 | if (buf[0] == '1') |
3994 | s->flags |= SLAB_DEBUG_FREE; |
3995 | return length; |
3996 | } |
3997 | SLAB_ATTR(sanity_checks); |
3998 | |
3999 | static ssize_t trace_show(struct kmem_cache *s, char *buf) |
4000 | { |
4001 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE)); |
4002 | } |
4003 | |
4004 | static ssize_t trace_store(struct kmem_cache *s, const char *buf, |
4005 | size_t length) |
4006 | { |
4007 | s->flags &= ~SLAB_TRACE; |
4008 | if (buf[0] == '1') |
4009 | s->flags |= SLAB_TRACE; |
4010 | return length; |
4011 | } |
4012 | SLAB_ATTR(trace); |
4013 | |
4014 | #ifdef CONFIG_FAILSLAB |
4015 | static ssize_t failslab_show(struct kmem_cache *s, char *buf) |
4016 | { |
4017 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB)); |
4018 | } |
4019 | |
4020 | static ssize_t failslab_store(struct kmem_cache *s, const char *buf, |
4021 | size_t length) |
4022 | { |
4023 | s->flags &= ~SLAB_FAILSLAB; |
4024 | if (buf[0] == '1') |
4025 | s->flags |= SLAB_FAILSLAB; |
4026 | return length; |
4027 | } |
4028 | SLAB_ATTR(failslab); |
4029 | #endif |
4030 | |
4031 | static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) |
4032 | { |
4033 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); |
4034 | } |
4035 | |
4036 | static ssize_t reclaim_account_store(struct kmem_cache *s, |
4037 | const char *buf, size_t length) |
4038 | { |
4039 | s->flags &= ~SLAB_RECLAIM_ACCOUNT; |
4040 | if (buf[0] == '1') |
4041 | s->flags |= SLAB_RECLAIM_ACCOUNT; |
4042 | return length; |
4043 | } |
4044 | SLAB_ATTR(reclaim_account); |
4045 | |
4046 | static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) |
4047 | { |
4048 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN)); |
4049 | } |
4050 | SLAB_ATTR_RO(hwcache_align); |
4051 | |
4052 | #ifdef CONFIG_ZONE_DMA |
4053 | static ssize_t cache_dma_show(struct kmem_cache *s, char *buf) |
4054 | { |
4055 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA)); |
4056 | } |
4057 | SLAB_ATTR_RO(cache_dma); |
4058 | #endif |
4059 | |
4060 | static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) |
4061 | { |
4062 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU)); |
4063 | } |
4064 | SLAB_ATTR_RO(destroy_by_rcu); |
4065 | |
4066 | static ssize_t red_zone_show(struct kmem_cache *s, char *buf) |
4067 | { |
4068 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE)); |
4069 | } |
4070 | |
4071 | static ssize_t red_zone_store(struct kmem_cache *s, |
4072 | const char *buf, size_t length) |
4073 | { |
4074 | if (any_slab_objects(s)) |
4075 | return -EBUSY; |
4076 | |
4077 | s->flags &= ~SLAB_RED_ZONE; |
4078 | if (buf[0] == '1') |
4079 | s->flags |= SLAB_RED_ZONE; |
4080 | calculate_sizes(s, -1); |
4081 | return length; |
4082 | } |
4083 | SLAB_ATTR(red_zone); |
4084 | |
4085 | static ssize_t poison_show(struct kmem_cache *s, char *buf) |
4086 | { |
4087 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON)); |
4088 | } |
4089 | |
4090 | static ssize_t poison_store(struct kmem_cache *s, |
4091 | const char *buf, size_t length) |
4092 | { |
4093 | if (any_slab_objects(s)) |
4094 | return -EBUSY; |
4095 | |
4096 | s->flags &= ~SLAB_POISON; |
4097 | if (buf[0] == '1') |
4098 | s->flags |= SLAB_POISON; |
4099 | calculate_sizes(s, -1); |
4100 | return length; |
4101 | } |
4102 | SLAB_ATTR(poison); |
4103 | |
4104 | static ssize_t store_user_show(struct kmem_cache *s, char *buf) |
4105 | { |
4106 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER)); |
4107 | } |
4108 | |
4109 | static ssize_t store_user_store(struct kmem_cache *s, |
4110 | const char *buf, size_t length) |
4111 | { |
4112 | if (any_slab_objects(s)) |
4113 | return -EBUSY; |
4114 | |
4115 | s->flags &= ~SLAB_STORE_USER; |
4116 | if (buf[0] == '1') |
4117 | s->flags |= SLAB_STORE_USER; |
4118 | calculate_sizes(s, -1); |
4119 | return length; |
4120 | } |
4121 | SLAB_ATTR(store_user); |
4122 | |
4123 | static ssize_t validate_show(struct kmem_cache *s, char *buf) |
4124 | { |
4125 | return 0; |
4126 | } |
4127 | |
4128 | static ssize_t validate_store(struct kmem_cache *s, |
4129 | const char *buf, size_t length) |
4130 | { |
4131 | int ret = -EINVAL; |
4132 | |
4133 | if (buf[0] == '1') { |
4134 | ret = validate_slab_cache(s); |
4135 | if (ret >= 0) |
4136 | ret = length; |
4137 | } |
4138 | return ret; |
4139 | } |
4140 | SLAB_ATTR(validate); |
4141 | |
4142 | static ssize_t shrink_show(struct kmem_cache *s, char *buf) |
4143 | { |
4144 | return 0; |
4145 | } |
4146 | |
4147 | static ssize_t shrink_store(struct kmem_cache *s, |
4148 | const char *buf, size_t length) |
4149 | { |
4150 | if (buf[0] == '1') { |
4151 | int rc = kmem_cache_shrink(s); |
4152 | |
4153 | if (rc) |
4154 | return rc; |
4155 | } else |
4156 | return -EINVAL; |
4157 | return length; |
4158 | } |
4159 | SLAB_ATTR(shrink); |
4160 | |
4161 | static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) |
4162 | { |
4163 | if (!(s->flags & SLAB_STORE_USER)) |
4164 | return -ENOSYS; |
4165 | return list_locations(s, buf, TRACK_ALLOC); |
4166 | } |
4167 | SLAB_ATTR_RO(alloc_calls); |
4168 | |
4169 | static ssize_t free_calls_show(struct kmem_cache *s, char *buf) |
4170 | { |
4171 | if (!(s->flags & SLAB_STORE_USER)) |
4172 | return -ENOSYS; |
4173 | return list_locations(s, buf, TRACK_FREE); |
4174 | } |
4175 | SLAB_ATTR_RO(free_calls); |
4176 | |
4177 | #ifdef CONFIG_NUMA |
4178 | static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf) |
4179 | { |
4180 | return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10); |
4181 | } |
4182 | |
4183 | static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s, |
4184 | const char *buf, size_t length) |
4185 | { |
4186 | unsigned long ratio; |
4187 | int err; |
4188 | |
4189 | err = strict_strtoul(buf, 10, &ratio); |
4190 | if (err) |
4191 | return err; |
4192 | |
4193 | if (ratio <= 100) |
4194 | s->remote_node_defrag_ratio = ratio * 10; |
4195 | |
4196 | return length; |
4197 | } |
4198 | SLAB_ATTR(remote_node_defrag_ratio); |
4199 | #endif |
4200 | |
4201 | #ifdef CONFIG_SLUB_STATS |
4202 | static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si) |
4203 | { |
4204 | unsigned long sum = 0; |
4205 | int cpu; |
4206 | int len; |
4207 | int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL); |
4208 | |
4209 | if (!data) |
4210 | return -ENOMEM; |
4211 | |
4212 | for_each_online_cpu(cpu) { |
4213 | unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si]; |
4214 | |
4215 | data[cpu] = x; |
4216 | sum += x; |
4217 | } |
4218 | |
4219 | len = sprintf(buf, "%lu", sum); |
4220 | |
4221 | #ifdef CONFIG_SMP |
4222 | for_each_online_cpu(cpu) { |
4223 | if (data[cpu] && len < PAGE_SIZE - 20) |
4224 | len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]); |
4225 | } |
4226 | #endif |
4227 | kfree(data); |
4228 | return len + sprintf(buf + len, "\n"); |
4229 | } |
4230 | |
4231 | static void clear_stat(struct kmem_cache *s, enum stat_item si) |
4232 | { |
4233 | int cpu; |
4234 | |
4235 | for_each_online_cpu(cpu) |
4236 | per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0; |
4237 | } |
4238 | |
4239 | #define STAT_ATTR(si, text) \ |
4240 | static ssize_t text##_show(struct kmem_cache *s, char *buf) \ |
4241 | { \ |
4242 | return show_stat(s, buf, si); \ |
4243 | } \ |
4244 | static ssize_t text##_store(struct kmem_cache *s, \ |
4245 | const char *buf, size_t length) \ |
4246 | { \ |
4247 | if (buf[0] != '0') \ |
4248 | return -EINVAL; \ |
4249 | clear_stat(s, si); \ |
4250 | return length; \ |
4251 | } \ |
4252 | SLAB_ATTR(text); \ |
4253 | |
4254 | STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath); |
4255 | STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath); |
4256 | STAT_ATTR(FREE_FASTPATH, free_fastpath); |
4257 | STAT_ATTR(FREE_SLOWPATH, free_slowpath); |
4258 | STAT_ATTR(FREE_FROZEN, free_frozen); |
4259 | STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial); |
4260 | STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial); |
4261 | STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial); |
4262 | STAT_ATTR(ALLOC_SLAB, alloc_slab); |
4263 | STAT_ATTR(ALLOC_REFILL, alloc_refill); |
4264 | STAT_ATTR(FREE_SLAB, free_slab); |
4265 | STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush); |
4266 | STAT_ATTR(DEACTIVATE_FULL, deactivate_full); |
4267 | STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty); |
4268 | STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head); |
4269 | STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail); |
4270 | STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees); |
4271 | STAT_ATTR(ORDER_FALLBACK, order_fallback); |
4272 | #endif |
4273 | |
4274 | static struct attribute *slab_attrs[] = { |
4275 | &slab_size_attr.attr, |
4276 | &object_size_attr.attr, |
4277 | &objs_per_slab_attr.attr, |
4278 | &order_attr.attr, |
4279 | &min_partial_attr.attr, |
4280 | &objects_attr.attr, |
4281 | &objects_partial_attr.attr, |
4282 | &total_objects_attr.attr, |
4283 | &slabs_attr.attr, |
4284 | &partial_attr.attr, |
4285 | &cpu_slabs_attr.attr, |
4286 | &ctor_attr.attr, |
4287 | &aliases_attr.attr, |
4288 | &align_attr.attr, |
4289 | &sanity_checks_attr.attr, |
4290 | &trace_attr.attr, |
4291 | &hwcache_align_attr.attr, |
4292 | &reclaim_account_attr.attr, |
4293 | &destroy_by_rcu_attr.attr, |
4294 | &red_zone_attr.attr, |
4295 | &poison_attr.attr, |
4296 | &store_user_attr.attr, |
4297 | &validate_attr.attr, |
4298 | &shrink_attr.attr, |
4299 | &alloc_calls_attr.attr, |
4300 | &free_calls_attr.attr, |
4301 | #ifdef CONFIG_ZONE_DMA |
4302 | &cache_dma_attr.attr, |
4303 | #endif |
4304 | #ifdef CONFIG_NUMA |
4305 | &remote_node_defrag_ratio_attr.attr, |
4306 | #endif |
4307 | #ifdef CONFIG_SLUB_STATS |
4308 | &alloc_fastpath_attr.attr, |
4309 | &alloc_slowpath_attr.attr, |
4310 | &free_fastpath_attr.attr, |
4311 | &free_slowpath_attr.attr, |
4312 | &free_frozen_attr.attr, |
4313 | &free_add_partial_attr.attr, |
4314 | &free_remove_partial_attr.attr, |
4315 | &alloc_from_partial_attr.attr, |
4316 | &alloc_slab_attr.attr, |
4317 | &alloc_refill_attr.attr, |
4318 | &free_slab_attr.attr, |
4319 | &cpuslab_flush_attr.attr, |
4320 | &deactivate_full_attr.attr, |
4321 | &deactivate_empty_attr.attr, |
4322 | &deactivate_to_head_attr.attr, |
4323 | &deactivate_to_tail_attr.attr, |
4324 | &deactivate_remote_frees_attr.attr, |
4325 | &order_fallback_attr.attr, |
4326 | #endif |
4327 | #ifdef CONFIG_FAILSLAB |
4328 | &failslab_attr.attr, |
4329 | #endif |
4330 | |
4331 | NULL |
4332 | }; |
4333 | |
4334 | static struct attribute_group slab_attr_group = { |
4335 | .attrs = slab_attrs, |
4336 | }; |
4337 | |
4338 | static ssize_t slab_attr_show(struct kobject *kobj, |
4339 | struct attribute *attr, |
4340 | char *buf) |
4341 | { |
4342 | struct slab_attribute *attribute; |
4343 | struct kmem_cache *s; |
4344 | int err; |
4345 | |
4346 | attribute = to_slab_attr(attr); |
4347 | s = to_slab(kobj); |
4348 | |
4349 | if (!attribute->show) |
4350 | return -EIO; |
4351 | |
4352 | err = attribute->show(s, buf); |
4353 | |
4354 | return err; |
4355 | } |
4356 | |
4357 | static ssize_t slab_attr_store(struct kobject *kobj, |
4358 | struct attribute *attr, |
4359 | const char *buf, size_t len) |
4360 | { |
4361 | struct slab_attribute *attribute; |
4362 | struct kmem_cache *s; |
4363 | int err; |
4364 | |
4365 | attribute = to_slab_attr(attr); |
4366 | s = to_slab(kobj); |
4367 | |
4368 | if (!attribute->store) |
4369 | return -EIO; |
4370 | |
4371 | err = attribute->store(s, buf, len); |
4372 | |
4373 | return err; |
4374 | } |
4375 | |
4376 | static void kmem_cache_release(struct kobject *kobj) |
4377 | { |
4378 | struct kmem_cache *s = to_slab(kobj); |
4379 | |
4380 | kfree(s); |
4381 | } |
4382 | |
4383 | static const struct sysfs_ops slab_sysfs_ops = { |
4384 | .show = slab_attr_show, |
4385 | .store = slab_attr_store, |
4386 | }; |
4387 | |
4388 | static struct kobj_type slab_ktype = { |
4389 | .sysfs_ops = &slab_sysfs_ops, |
4390 | .release = kmem_cache_release |
4391 | }; |
4392 | |
4393 | static int uevent_filter(struct kset *kset, struct kobject *kobj) |
4394 | { |
4395 | struct kobj_type *ktype = get_ktype(kobj); |
4396 | |
4397 | if (ktype == &slab_ktype) |
4398 | return 1; |
4399 | return 0; |
4400 | } |
4401 | |
4402 | static const struct kset_uevent_ops slab_uevent_ops = { |
4403 | .filter = uevent_filter, |
4404 | }; |
4405 | |
4406 | static struct kset *slab_kset; |
4407 | |
4408 | #define ID_STR_LENGTH 64 |
4409 | |
4410 | /* Create a unique string id for a slab cache: |
4411 | * |
4412 | * Format :[flags-]size |
4413 | */ |
4414 | static char *create_unique_id(struct kmem_cache *s) |
4415 | { |
4416 | char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); |
4417 | char *p = name; |
4418 | |
4419 | BUG_ON(!name); |
4420 | |
4421 | *p++ = ':'; |
4422 | /* |
4423 | * First flags affecting slabcache operations. We will only |
4424 | * get here for aliasable slabs so we do not need to support |
4425 | * too many flags. The flags here must cover all flags that |
4426 | * are matched during merging to guarantee that the id is |
4427 | * unique. |
4428 | */ |
4429 | if (s->flags & SLAB_CACHE_DMA) |
4430 | *p++ = 'd'; |
4431 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
4432 | *p++ = 'a'; |
4433 | if (s->flags & SLAB_DEBUG_FREE) |
4434 | *p++ = 'F'; |
4435 | if (!(s->flags & SLAB_NOTRACK)) |
4436 | *p++ = 't'; |
4437 | if (p != name + 1) |
4438 | *p++ = '-'; |
4439 | p += sprintf(p, "%07d", s->size); |
4440 | BUG_ON(p > name + ID_STR_LENGTH - 1); |
4441 | return name; |
4442 | } |
4443 | |
4444 | static int sysfs_slab_add(struct kmem_cache *s) |
4445 | { |
4446 | int err; |
4447 | const char *name; |
4448 | int unmergeable; |
4449 | |
4450 | if (slab_state < SYSFS) |
4451 | /* Defer until later */ |
4452 | return 0; |
4453 | |
4454 | unmergeable = slab_unmergeable(s); |
4455 | if (unmergeable) { |
4456 | /* |
4457 | * Slabcache can never be merged so we can use the name proper. |
4458 | * This is typically the case for debug situations. In that |
4459 | * case we can catch duplicate names easily. |
4460 | */ |
4461 | sysfs_remove_link(&slab_kset->kobj, s->name); |
4462 | name = s->name; |
4463 | } else { |
4464 | /* |
4465 | * Create a unique name for the slab as a target |
4466 | * for the symlinks. |
4467 | */ |
4468 | name = create_unique_id(s); |
4469 | } |
4470 | |
4471 | s->kobj.kset = slab_kset; |
4472 | err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name); |
4473 | if (err) { |
4474 | kobject_put(&s->kobj); |
4475 | return err; |
4476 | } |
4477 | |
4478 | err = sysfs_create_group(&s->kobj, &slab_attr_group); |
4479 | if (err) { |
4480 | kobject_del(&s->kobj); |
4481 | kobject_put(&s->kobj); |
4482 | return err; |
4483 | } |
4484 | kobject_uevent(&s->kobj, KOBJ_ADD); |
4485 | if (!unmergeable) { |
4486 | /* Setup first alias */ |
4487 | sysfs_slab_alias(s, s->name); |
4488 | kfree(name); |
4489 | } |
4490 | return 0; |
4491 | } |
4492 | |
4493 | static void sysfs_slab_remove(struct kmem_cache *s) |
4494 | { |
4495 | if (slab_state < SYSFS) |
4496 | /* |
4497 | * Sysfs has not been setup yet so no need to remove the |
4498 | * cache from sysfs. |
4499 | */ |
4500 | return; |
4501 | |
4502 | kobject_uevent(&s->kobj, KOBJ_REMOVE); |
4503 | kobject_del(&s->kobj); |
4504 | kobject_put(&s->kobj); |
4505 | } |
4506 | |
4507 | /* |
4508 | * Need to buffer aliases during bootup until sysfs becomes |
4509 | * available lest we lose that information. |
4510 | */ |
4511 | struct saved_alias { |
4512 | struct kmem_cache *s; |
4513 | const char *name; |
4514 | struct saved_alias *next; |
4515 | }; |
4516 | |
4517 | static struct saved_alias *alias_list; |
4518 | |
4519 | static int sysfs_slab_alias(struct kmem_cache *s, const char *name) |
4520 | { |
4521 | struct saved_alias *al; |
4522 | |
4523 | if (slab_state == SYSFS) { |
4524 | /* |
4525 | * If we have a leftover link then remove it. |
4526 | */ |
4527 | sysfs_remove_link(&slab_kset->kobj, name); |
4528 | return sysfs_create_link(&slab_kset->kobj, &s->kobj, name); |
4529 | } |
4530 | |
4531 | al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); |
4532 | if (!al) |
4533 | return -ENOMEM; |
4534 | |
4535 | al->s = s; |
4536 | al->name = name; |
4537 | al->next = alias_list; |
4538 | alias_list = al; |
4539 | return 0; |
4540 | } |
4541 | |
4542 | static int __init slab_sysfs_init(void) |
4543 | { |
4544 | struct kmem_cache *s; |
4545 | int err; |
4546 | |
4547 | down_write(&slub_lock); |
4548 | |
4549 | slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj); |
4550 | if (!slab_kset) { |
4551 | up_write(&slub_lock); |
4552 | printk(KERN_ERR "Cannot register slab subsystem.\n"); |
4553 | return -ENOSYS; |
4554 | } |
4555 | |
4556 | slab_state = SYSFS; |
4557 | |
4558 | list_for_each_entry(s, &slab_caches, list) { |
4559 | err = sysfs_slab_add(s); |
4560 | if (err) |
4561 | printk(KERN_ERR "SLUB: Unable to add boot slab %s" |
4562 | " to sysfs\n", s->name); |
4563 | } |
4564 | |
4565 | while (alias_list) { |
4566 | struct saved_alias *al = alias_list; |
4567 | |
4568 | alias_list = alias_list->next; |
4569 | err = sysfs_slab_alias(al->s, al->name); |
4570 | if (err) |
4571 | printk(KERN_ERR "SLUB: Unable to add boot slab alias" |
4572 | " %s to sysfs\n", s->name); |
4573 | kfree(al); |
4574 | } |
4575 | |
4576 | up_write(&slub_lock); |
4577 | resiliency_test(); |
4578 | return 0; |
4579 | } |
4580 | |
4581 | __initcall(slab_sysfs_init); |
4582 | #endif |
4583 | |
4584 | /* |
4585 | * The /proc/slabinfo ABI |
4586 | */ |
4587 | #ifdef CONFIG_SLABINFO |
4588 | static void print_slabinfo_header(struct seq_file *m) |
4589 | { |
4590 | seq_puts(m, "slabinfo - version: 2.1\n"); |
4591 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " |
4592 | "<objperslab> <pagesperslab>"); |
4593 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
4594 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); |
4595 | seq_putc(m, '\n'); |
4596 | } |
4597 | |
4598 | static void *s_start(struct seq_file *m, loff_t *pos) |
4599 | { |
4600 | loff_t n = *pos; |
4601 | |
4602 | down_read(&slub_lock); |
4603 | if (!n) |
4604 | print_slabinfo_header(m); |
4605 | |
4606 | return seq_list_start(&slab_caches, *pos); |
4607 | } |
4608 | |
4609 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) |
4610 | { |
4611 | return seq_list_next(p, &slab_caches, pos); |
4612 | } |
4613 | |
4614 | static void s_stop(struct seq_file *m, void *p) |
4615 | { |
4616 | up_read(&slub_lock); |
4617 | } |
4618 | |
4619 | static int s_show(struct seq_file *m, void *p) |
4620 | { |
4621 | unsigned long nr_partials = 0; |
4622 | unsigned long nr_slabs = 0; |
4623 | unsigned long nr_inuse = 0; |
4624 | unsigned long nr_objs = 0; |
4625 | unsigned long nr_free = 0; |
4626 | struct kmem_cache *s; |
4627 | int node; |
4628 | |
4629 | s = list_entry(p, struct kmem_cache, list); |
4630 | |
4631 | for_each_online_node(node) { |
4632 | struct kmem_cache_node *n = get_node(s, node); |
4633 | |
4634 | if (!n) |
4635 | continue; |
4636 | |
4637 | nr_partials += n->nr_partial; |
4638 | nr_slabs += atomic_long_read(&n->nr_slabs); |
4639 | nr_objs += atomic_long_read(&n->total_objects); |
4640 | nr_free += count_partial(n, count_free); |
4641 | } |
4642 | |
4643 | nr_inuse = nr_objs - nr_free; |
4644 | |
4645 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse, |
4646 | nr_objs, s->size, oo_objects(s->oo), |
4647 | (1 << oo_order(s->oo))); |
4648 | seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0); |
4649 | seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs, |
4650 | 0UL); |
4651 | seq_putc(m, '\n'); |
4652 | return 0; |
4653 | } |
4654 | |
4655 | static const struct seq_operations slabinfo_op = { |
4656 | .start = s_start, |
4657 | .next = s_next, |
4658 | .stop = s_stop, |
4659 | .show = s_show, |
4660 | }; |
4661 | |
4662 | static int slabinfo_open(struct inode *inode, struct file *file) |
4663 | { |
4664 | return seq_open(file, &slabinfo_op); |
4665 | } |
4666 | |
4667 | static const struct file_operations proc_slabinfo_operations = { |
4668 | .open = slabinfo_open, |
4669 | .read = seq_read, |
4670 | .llseek = seq_lseek, |
4671 | .release = seq_release, |
4672 | }; |
4673 | |
4674 | static int __init slab_proc_init(void) |
4675 | { |
4676 | proc_create("slabinfo", S_IRUGO, NULL, &proc_slabinfo_operations); |
4677 | return 0; |
4678 | } |
4679 | module_init(slab_proc_init); |
4680 | #endif /* CONFIG_SLABINFO */ |
4681 |
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