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Commit | Line | Data |
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81819f0f CL |
1 | /* |
2 | * SLUB: A slab allocator that limits cache line use instead of queuing | |
3 | * objects in per cpu and per node lists. | |
4 | * | |
5 | * The allocator synchronizes using per slab locks and only | |
6 | * uses a centralized lock to manage a pool of partial slabs. | |
7 | * | |
8 | * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com> | |
9 | */ | |
10 | ||
11 | #include <linux/mm.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/bit_spinlock.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/bitops.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/seq_file.h> | |
18 | #include <linux/cpu.h> | |
19 | #include <linux/cpuset.h> | |
20 | #include <linux/mempolicy.h> | |
21 | #include <linux/ctype.h> | |
22 | #include <linux/kallsyms.h> | |
23 | ||
24 | /* | |
25 | * Lock order: | |
26 | * 1. slab_lock(page) | |
27 | * 2. slab->list_lock | |
28 | * | |
29 | * The slab_lock protects operations on the object of a particular | |
30 | * slab and its metadata in the page struct. If the slab lock | |
31 | * has been taken then no allocations nor frees can be performed | |
32 | * on the objects in the slab nor can the slab be added or removed | |
33 | * from the partial or full lists since this would mean modifying | |
34 | * the page_struct of the slab. | |
35 | * | |
36 | * The list_lock protects the partial and full list on each node and | |
37 | * the partial slab counter. If taken then no new slabs may be added or | |
38 | * removed from the lists nor make the number of partial slabs be modified. | |
39 | * (Note that the total number of slabs is an atomic value that may be | |
40 | * modified without taking the list lock). | |
41 | * | |
42 | * The list_lock is a centralized lock and thus we avoid taking it as | |
43 | * much as possible. As long as SLUB does not have to handle partial | |
44 | * slabs, operations can continue without any centralized lock. F.e. | |
45 | * allocating a long series of objects that fill up slabs does not require | |
46 | * the list lock. | |
47 | * | |
48 | * The lock order is sometimes inverted when we are trying to get a slab | |
49 | * off a list. We take the list_lock and then look for a page on the list | |
50 | * to use. While we do that objects in the slabs may be freed. We can | |
51 | * only operate on the slab if we have also taken the slab_lock. So we use | |
52 | * a slab_trylock() on the slab. If trylock was successful then no frees | |
53 | * can occur anymore and we can use the slab for allocations etc. If the | |
54 | * slab_trylock() does not succeed then frees are in progress in the slab and | |
55 | * we must stay away from it for a while since we may cause a bouncing | |
56 | * cacheline if we try to acquire the lock. So go onto the next slab. | |
57 | * If all pages are busy then we may allocate a new slab instead of reusing | |
58 | * a partial slab. A new slab has noone operating on it and thus there is | |
59 | * no danger of cacheline contention. | |
60 | * | |
61 | * Interrupts are disabled during allocation and deallocation in order to | |
62 | * make the slab allocator safe to use in the context of an irq. In addition | |
63 | * interrupts are disabled to ensure that the processor does not change | |
64 | * while handling per_cpu slabs, due to kernel preemption. | |
65 | * | |
66 | * SLUB assigns one slab for allocation to each processor. | |
67 | * Allocations only occur from these slabs called cpu slabs. | |
68 | * | |
69 | * Slabs with free elements are kept on a partial list. | |
70 | * There is no list for full slabs. If an object in a full slab is | |
71 | * freed then the slab will show up again on the partial lists. | |
72 | * Otherwise there is no need to track full slabs unless we have to | |
73 | * track full slabs for debugging purposes. | |
74 | * | |
75 | * Slabs are freed when they become empty. Teardown and setup is | |
76 | * minimal so we rely on the page allocators per cpu caches for | |
77 | * fast frees and allocs. | |
78 | * | |
79 | * Overloading of page flags that are otherwise used for LRU management. | |
80 | * | |
81 | * PageActive The slab is used as a cpu cache. Allocations | |
82 | * may be performed from the slab. The slab is not | |
83 | * on any slab list and cannot be moved onto one. | |
84 | * | |
85 | * PageError Slab requires special handling due to debug | |
86 | * options set. This moves slab handling out of | |
87 | * the fast path. | |
88 | */ | |
89 | ||
90 | /* | |
91 | * Issues still to be resolved: | |
92 | * | |
93 | * - The per cpu array is updated for each new slab and and is a remote | |
94 | * cacheline for most nodes. This could become a bouncing cacheline given | |
95 | * enough frequent updates. There are 16 pointers in a cacheline.so at | |
96 | * max 16 cpus could compete. Likely okay. | |
97 | * | |
98 | * - Support PAGE_ALLOC_DEBUG. Should be easy to do. | |
99 | * | |
81819f0f CL |
100 | * - SLAB_DEBUG_INITIAL is not supported but I have never seen a use of |
101 | * it. | |
102 | * | |
103 | * - Variable sizing of the per node arrays | |
104 | */ | |
105 | ||
106 | /* Enable to test recovery from slab corruption on boot */ | |
107 | #undef SLUB_RESILIENCY_TEST | |
108 | ||
109 | #if PAGE_SHIFT <= 12 | |
110 | ||
111 | /* | |
112 | * Small page size. Make sure that we do not fragment memory | |
113 | */ | |
114 | #define DEFAULT_MAX_ORDER 1 | |
115 | #define DEFAULT_MIN_OBJECTS 4 | |
116 | ||
117 | #else | |
118 | ||
119 | /* | |
120 | * Large page machines are customarily able to handle larger | |
121 | * page orders. | |
122 | */ | |
123 | #define DEFAULT_MAX_ORDER 2 | |
124 | #define DEFAULT_MIN_OBJECTS 8 | |
125 | ||
126 | #endif | |
127 | ||
128 | /* | |
129 | * Flags from the regular SLAB that SLUB does not support: | |
130 | */ | |
131 | #define SLUB_UNIMPLEMENTED (SLAB_DEBUG_INITIAL) | |
132 | ||
2086d26a CL |
133 | /* |
134 | * Mininum number of partial slabs. These will be left on the partial | |
135 | * lists even if they are empty. kmem_cache_shrink may reclaim them. | |
136 | */ | |
e95eed57 CL |
137 | #define MIN_PARTIAL 2 |
138 | ||
2086d26a CL |
139 | /* |
140 | * Maximum number of desirable partial slabs. | |
141 | * The existence of more partial slabs makes kmem_cache_shrink | |
142 | * sort the partial list by the number of objects in the. | |
143 | */ | |
144 | #define MAX_PARTIAL 10 | |
145 | ||
81819f0f CL |
146 | #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \ |
147 | SLAB_POISON | SLAB_STORE_USER) | |
148 | /* | |
149 | * Set of flags that will prevent slab merging | |
150 | */ | |
151 | #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
152 | SLAB_TRACE | SLAB_DESTROY_BY_RCU) | |
153 | ||
154 | #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ | |
155 | SLAB_CACHE_DMA) | |
156 | ||
157 | #ifndef ARCH_KMALLOC_MINALIGN | |
47bfdc0d | 158 | #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) |
81819f0f CL |
159 | #endif |
160 | ||
161 | #ifndef ARCH_SLAB_MINALIGN | |
47bfdc0d | 162 | #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long) |
81819f0f CL |
163 | #endif |
164 | ||
165 | /* Internal SLUB flags */ | |
166 | #define __OBJECT_POISON 0x80000000 /* Poison object */ | |
167 | ||
168 | static int kmem_size = sizeof(struct kmem_cache); | |
169 | ||
170 | #ifdef CONFIG_SMP | |
171 | static struct notifier_block slab_notifier; | |
172 | #endif | |
173 | ||
174 | static enum { | |
175 | DOWN, /* No slab functionality available */ | |
176 | PARTIAL, /* kmem_cache_open() works but kmalloc does not */ | |
177 | UP, /* Everything works */ | |
178 | SYSFS /* Sysfs up */ | |
179 | } slab_state = DOWN; | |
180 | ||
181 | /* A list of all slab caches on the system */ | |
182 | static DECLARE_RWSEM(slub_lock); | |
183 | LIST_HEAD(slab_caches); | |
184 | ||
185 | #ifdef CONFIG_SYSFS | |
186 | static int sysfs_slab_add(struct kmem_cache *); | |
187 | static int sysfs_slab_alias(struct kmem_cache *, const char *); | |
188 | static void sysfs_slab_remove(struct kmem_cache *); | |
189 | #else | |
190 | static int sysfs_slab_add(struct kmem_cache *s) { return 0; } | |
191 | static int sysfs_slab_alias(struct kmem_cache *s, const char *p) { return 0; } | |
192 | static void sysfs_slab_remove(struct kmem_cache *s) {} | |
193 | #endif | |
194 | ||
195 | /******************************************************************** | |
196 | * Core slab cache functions | |
197 | *******************************************************************/ | |
198 | ||
199 | int slab_is_available(void) | |
200 | { | |
201 | return slab_state >= UP; | |
202 | } | |
203 | ||
204 | static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) | |
205 | { | |
206 | #ifdef CONFIG_NUMA | |
207 | return s->node[node]; | |
208 | #else | |
209 | return &s->local_node; | |
210 | #endif | |
211 | } | |
212 | ||
213 | /* | |
214 | * Object debugging | |
215 | */ | |
216 | static void print_section(char *text, u8 *addr, unsigned int length) | |
217 | { | |
218 | int i, offset; | |
219 | int newline = 1; | |
220 | char ascii[17]; | |
221 | ||
222 | ascii[16] = 0; | |
223 | ||
224 | for (i = 0; i < length; i++) { | |
225 | if (newline) { | |
226 | printk(KERN_ERR "%10s 0x%p: ", text, addr + i); | |
227 | newline = 0; | |
228 | } | |
229 | printk(" %02x", addr[i]); | |
230 | offset = i % 16; | |
231 | ascii[offset] = isgraph(addr[i]) ? addr[i] : '.'; | |
232 | if (offset == 15) { | |
233 | printk(" %s\n",ascii); | |
234 | newline = 1; | |
235 | } | |
236 | } | |
237 | if (!newline) { | |
238 | i %= 16; | |
239 | while (i < 16) { | |
240 | printk(" "); | |
241 | ascii[i] = ' '; | |
242 | i++; | |
243 | } | |
244 | printk(" %s\n", ascii); | |
245 | } | |
246 | } | |
247 | ||
248 | /* | |
249 | * Slow version of get and set free pointer. | |
250 | * | |
251 | * This requires touching the cache lines of kmem_cache. | |
252 | * The offset can also be obtained from the page. In that | |
253 | * case it is in the cacheline that we already need to touch. | |
254 | */ | |
255 | static void *get_freepointer(struct kmem_cache *s, void *object) | |
256 | { | |
257 | return *(void **)(object + s->offset); | |
258 | } | |
259 | ||
260 | static void set_freepointer(struct kmem_cache *s, void *object, void *fp) | |
261 | { | |
262 | *(void **)(object + s->offset) = fp; | |
263 | } | |
264 | ||
265 | /* | |
266 | * Tracking user of a slab. | |
267 | */ | |
268 | struct track { | |
269 | void *addr; /* Called from address */ | |
270 | int cpu; /* Was running on cpu */ | |
271 | int pid; /* Pid context */ | |
272 | unsigned long when; /* When did the operation occur */ | |
273 | }; | |
274 | ||
275 | enum track_item { TRACK_ALLOC, TRACK_FREE }; | |
276 | ||
277 | static struct track *get_track(struct kmem_cache *s, void *object, | |
278 | enum track_item alloc) | |
279 | { | |
280 | struct track *p; | |
281 | ||
282 | if (s->offset) | |
283 | p = object + s->offset + sizeof(void *); | |
284 | else | |
285 | p = object + s->inuse; | |
286 | ||
287 | return p + alloc; | |
288 | } | |
289 | ||
290 | static void set_track(struct kmem_cache *s, void *object, | |
291 | enum track_item alloc, void *addr) | |
292 | { | |
293 | struct track *p; | |
294 | ||
295 | if (s->offset) | |
296 | p = object + s->offset + sizeof(void *); | |
297 | else | |
298 | p = object + s->inuse; | |
299 | ||
300 | p += alloc; | |
301 | if (addr) { | |
302 | p->addr = addr; | |
303 | p->cpu = smp_processor_id(); | |
304 | p->pid = current ? current->pid : -1; | |
305 | p->when = jiffies; | |
306 | } else | |
307 | memset(p, 0, sizeof(struct track)); | |
308 | } | |
309 | ||
81819f0f CL |
310 | static void init_tracking(struct kmem_cache *s, void *object) |
311 | { | |
312 | if (s->flags & SLAB_STORE_USER) { | |
313 | set_track(s, object, TRACK_FREE, NULL); | |
314 | set_track(s, object, TRACK_ALLOC, NULL); | |
315 | } | |
316 | } | |
317 | ||
318 | static void print_track(const char *s, struct track *t) | |
319 | { | |
320 | if (!t->addr) | |
321 | return; | |
322 | ||
323 | printk(KERN_ERR "%s: ", s); | |
324 | __print_symbol("%s", (unsigned long)t->addr); | |
325 | printk(" jiffies_ago=%lu cpu=%u pid=%d\n", jiffies - t->when, t->cpu, t->pid); | |
326 | } | |
327 | ||
328 | static void print_trailer(struct kmem_cache *s, u8 *p) | |
329 | { | |
330 | unsigned int off; /* Offset of last byte */ | |
331 | ||
332 | if (s->flags & SLAB_RED_ZONE) | |
333 | print_section("Redzone", p + s->objsize, | |
334 | s->inuse - s->objsize); | |
335 | ||
336 | printk(KERN_ERR "FreePointer 0x%p -> 0x%p\n", | |
337 | p + s->offset, | |
338 | get_freepointer(s, p)); | |
339 | ||
340 | if (s->offset) | |
341 | off = s->offset + sizeof(void *); | |
342 | else | |
343 | off = s->inuse; | |
344 | ||
345 | if (s->flags & SLAB_STORE_USER) { | |
346 | print_track("Last alloc", get_track(s, p, TRACK_ALLOC)); | |
347 | print_track("Last free ", get_track(s, p, TRACK_FREE)); | |
348 | off += 2 * sizeof(struct track); | |
349 | } | |
350 | ||
351 | if (off != s->size) | |
352 | /* Beginning of the filler is the free pointer */ | |
353 | print_section("Filler", p + off, s->size - off); | |
354 | } | |
355 | ||
356 | static void object_err(struct kmem_cache *s, struct page *page, | |
357 | u8 *object, char *reason) | |
358 | { | |
359 | u8 *addr = page_address(page); | |
360 | ||
361 | printk(KERN_ERR "*** SLUB %s: %s@0x%p slab 0x%p\n", | |
362 | s->name, reason, object, page); | |
363 | printk(KERN_ERR " offset=%tu flags=0x%04lx inuse=%u freelist=0x%p\n", | |
364 | object - addr, page->flags, page->inuse, page->freelist); | |
365 | if (object > addr + 16) | |
366 | print_section("Bytes b4", object - 16, 16); | |
367 | print_section("Object", object, min(s->objsize, 128)); | |
368 | print_trailer(s, object); | |
369 | dump_stack(); | |
370 | } | |
371 | ||
372 | static void slab_err(struct kmem_cache *s, struct page *page, char *reason, ...) | |
373 | { | |
374 | va_list args; | |
375 | char buf[100]; | |
376 | ||
377 | va_start(args, reason); | |
378 | vsnprintf(buf, sizeof(buf), reason, args); | |
379 | va_end(args); | |
380 | printk(KERN_ERR "*** SLUB %s: %s in slab @0x%p\n", s->name, buf, | |
381 | page); | |
382 | dump_stack(); | |
383 | } | |
384 | ||
385 | static void init_object(struct kmem_cache *s, void *object, int active) | |
386 | { | |
387 | u8 *p = object; | |
388 | ||
389 | if (s->flags & __OBJECT_POISON) { | |
390 | memset(p, POISON_FREE, s->objsize - 1); | |
391 | p[s->objsize -1] = POISON_END; | |
392 | } | |
393 | ||
394 | if (s->flags & SLAB_RED_ZONE) | |
395 | memset(p + s->objsize, | |
396 | active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE, | |
397 | s->inuse - s->objsize); | |
398 | } | |
399 | ||
400 | static int check_bytes(u8 *start, unsigned int value, unsigned int bytes) | |
401 | { | |
402 | while (bytes) { | |
403 | if (*start != (u8)value) | |
404 | return 0; | |
405 | start++; | |
406 | bytes--; | |
407 | } | |
408 | return 1; | |
409 | } | |
410 | ||
411 | ||
412 | static int check_valid_pointer(struct kmem_cache *s, struct page *page, | |
413 | void *object) | |
414 | { | |
415 | void *base; | |
416 | ||
417 | if (!object) | |
418 | return 1; | |
419 | ||
420 | base = page_address(page); | |
421 | if (object < base || object >= base + s->objects * s->size || | |
422 | (object - base) % s->size) { | |
423 | return 0; | |
424 | } | |
425 | ||
426 | return 1; | |
427 | } | |
428 | ||
429 | /* | |
430 | * Object layout: | |
431 | * | |
432 | * object address | |
433 | * Bytes of the object to be managed. | |
434 | * If the freepointer may overlay the object then the free | |
435 | * pointer is the first word of the object. | |
436 | * Poisoning uses 0x6b (POISON_FREE) and the last byte is | |
437 | * 0xa5 (POISON_END) | |
438 | * | |
439 | * object + s->objsize | |
440 | * Padding to reach word boundary. This is also used for Redzoning. | |
441 | * Padding is extended to word size if Redzoning is enabled | |
442 | * and objsize == inuse. | |
443 | * We fill with 0xbb (RED_INACTIVE) for inactive objects and with | |
444 | * 0xcc (RED_ACTIVE) for objects in use. | |
445 | * | |
446 | * object + s->inuse | |
447 | * A. Free pointer (if we cannot overwrite object on free) | |
448 | * B. Tracking data for SLAB_STORE_USER | |
449 | * C. Padding to reach required alignment boundary | |
450 | * Padding is done using 0x5a (POISON_INUSE) | |
451 | * | |
452 | * object + s->size | |
453 | * | |
454 | * If slabcaches are merged then the objsize and inuse boundaries are to | |
455 | * be ignored. And therefore no slab options that rely on these boundaries | |
456 | * may be used with merged slabcaches. | |
457 | */ | |
458 | ||
459 | static void restore_bytes(struct kmem_cache *s, char *message, u8 data, | |
460 | void *from, void *to) | |
461 | { | |
70d71228 | 462 | printk(KERN_ERR "@@@ SLUB %s: Restoring %s (0x%x) from 0x%p-0x%p\n", |
81819f0f CL |
463 | s->name, message, data, from, to - 1); |
464 | memset(from, data, to - from); | |
465 | } | |
466 | ||
467 | static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p) | |
468 | { | |
469 | unsigned long off = s->inuse; /* The end of info */ | |
470 | ||
471 | if (s->offset) | |
472 | /* Freepointer is placed after the object. */ | |
473 | off += sizeof(void *); | |
474 | ||
475 | if (s->flags & SLAB_STORE_USER) | |
476 | /* We also have user information there */ | |
477 | off += 2 * sizeof(struct track); | |
478 | ||
479 | if (s->size == off) | |
480 | return 1; | |
481 | ||
482 | if (check_bytes(p + off, POISON_INUSE, s->size - off)) | |
483 | return 1; | |
484 | ||
485 | object_err(s, page, p, "Object padding check fails"); | |
486 | ||
487 | /* | |
488 | * Restore padding | |
489 | */ | |
490 | restore_bytes(s, "object padding", POISON_INUSE, p + off, p + s->size); | |
491 | return 0; | |
492 | } | |
493 | ||
494 | static int slab_pad_check(struct kmem_cache *s, struct page *page) | |
495 | { | |
496 | u8 *p; | |
497 | int length, remainder; | |
498 | ||
499 | if (!(s->flags & SLAB_POISON)) | |
500 | return 1; | |
501 | ||
502 | p = page_address(page); | |
503 | length = s->objects * s->size; | |
504 | remainder = (PAGE_SIZE << s->order) - length; | |
505 | if (!remainder) | |
506 | return 1; | |
507 | ||
508 | if (!check_bytes(p + length, POISON_INUSE, remainder)) { | |
70d71228 | 509 | slab_err(s, page, "Padding check failed"); |
81819f0f CL |
510 | restore_bytes(s, "slab padding", POISON_INUSE, p + length, |
511 | p + length + remainder); | |
512 | return 0; | |
513 | } | |
514 | return 1; | |
515 | } | |
516 | ||
517 | static int check_object(struct kmem_cache *s, struct page *page, | |
518 | void *object, int active) | |
519 | { | |
520 | u8 *p = object; | |
521 | u8 *endobject = object + s->objsize; | |
522 | ||
523 | if (s->flags & SLAB_RED_ZONE) { | |
524 | unsigned int red = | |
525 | active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE; | |
526 | ||
527 | if (!check_bytes(endobject, red, s->inuse - s->objsize)) { | |
528 | object_err(s, page, object, | |
529 | active ? "Redzone Active" : "Redzone Inactive"); | |
530 | restore_bytes(s, "redzone", red, | |
531 | endobject, object + s->inuse); | |
532 | return 0; | |
533 | } | |
534 | } else { | |
535 | if ((s->flags & SLAB_POISON) && s->objsize < s->inuse && | |
536 | !check_bytes(endobject, POISON_INUSE, | |
537 | s->inuse - s->objsize)) { | |
538 | object_err(s, page, p, "Alignment padding check fails"); | |
539 | /* | |
540 | * Fix it so that there will not be another report. | |
541 | * | |
542 | * Hmmm... We may be corrupting an object that now expects | |
543 | * to be longer than allowed. | |
544 | */ | |
545 | restore_bytes(s, "alignment padding", POISON_INUSE, | |
546 | endobject, object + s->inuse); | |
547 | } | |
548 | } | |
549 | ||
550 | if (s->flags & SLAB_POISON) { | |
551 | if (!active && (s->flags & __OBJECT_POISON) && | |
552 | (!check_bytes(p, POISON_FREE, s->objsize - 1) || | |
553 | p[s->objsize - 1] != POISON_END)) { | |
554 | ||
555 | object_err(s, page, p, "Poison check failed"); | |
556 | restore_bytes(s, "Poison", POISON_FREE, | |
557 | p, p + s->objsize -1); | |
558 | restore_bytes(s, "Poison", POISON_END, | |
559 | p + s->objsize - 1, p + s->objsize); | |
560 | return 0; | |
561 | } | |
562 | /* | |
563 | * check_pad_bytes cleans up on its own. | |
564 | */ | |
565 | check_pad_bytes(s, page, p); | |
566 | } | |
567 | ||
568 | if (!s->offset && active) | |
569 | /* | |
570 | * Object and freepointer overlap. Cannot check | |
571 | * freepointer while object is allocated. | |
572 | */ | |
573 | return 1; | |
574 | ||
575 | /* Check free pointer validity */ | |
576 | if (!check_valid_pointer(s, page, get_freepointer(s, p))) { | |
577 | object_err(s, page, p, "Freepointer corrupt"); | |
578 | /* | |
579 | * No choice but to zap it and thus loose the remainder | |
580 | * of the free objects in this slab. May cause | |
581 | * another error because the object count maybe | |
582 | * wrong now. | |
583 | */ | |
584 | set_freepointer(s, p, NULL); | |
585 | return 0; | |
586 | } | |
587 | return 1; | |
588 | } | |
589 | ||
590 | static int check_slab(struct kmem_cache *s, struct page *page) | |
591 | { | |
592 | VM_BUG_ON(!irqs_disabled()); | |
593 | ||
594 | if (!PageSlab(page)) { | |
70d71228 CL |
595 | slab_err(s, page, "Not a valid slab page flags=%lx " |
596 | "mapping=0x%p count=%d", page->flags, page->mapping, | |
81819f0f CL |
597 | page_count(page)); |
598 | return 0; | |
599 | } | |
600 | if (page->offset * sizeof(void *) != s->offset) { | |
70d71228 CL |
601 | slab_err(s, page, "Corrupted offset %lu flags=0x%lx " |
602 | "mapping=0x%p count=%d", | |
81819f0f | 603 | (unsigned long)(page->offset * sizeof(void *)), |
81819f0f CL |
604 | page->flags, |
605 | page->mapping, | |
606 | page_count(page)); | |
81819f0f CL |
607 | return 0; |
608 | } | |
609 | if (page->inuse > s->objects) { | |
70d71228 CL |
610 | slab_err(s, page, "inuse %u > max %u @0x%p flags=%lx " |
611 | "mapping=0x%p count=%d", | |
612 | s->name, page->inuse, s->objects, page->flags, | |
81819f0f | 613 | page->mapping, page_count(page)); |
81819f0f CL |
614 | return 0; |
615 | } | |
616 | /* Slab_pad_check fixes things up after itself */ | |
617 | slab_pad_check(s, page); | |
618 | return 1; | |
619 | } | |
620 | ||
621 | /* | |
622 | * Determine if a certain object on a page is on the freelist and | |
623 | * therefore free. Must hold the slab lock for cpu slabs to | |
624 | * guarantee that the chains are consistent. | |
625 | */ | |
626 | static int on_freelist(struct kmem_cache *s, struct page *page, void *search) | |
627 | { | |
628 | int nr = 0; | |
629 | void *fp = page->freelist; | |
630 | void *object = NULL; | |
631 | ||
632 | while (fp && nr <= s->objects) { | |
633 | if (fp == search) | |
634 | return 1; | |
635 | if (!check_valid_pointer(s, page, fp)) { | |
636 | if (object) { | |
637 | object_err(s, page, object, | |
638 | "Freechain corrupt"); | |
639 | set_freepointer(s, object, NULL); | |
640 | break; | |
641 | } else { | |
70d71228 CL |
642 | slab_err(s, page, "Freepointer 0x%p corrupt", |
643 | fp); | |
81819f0f CL |
644 | page->freelist = NULL; |
645 | page->inuse = s->objects; | |
70d71228 CL |
646 | printk(KERN_ERR "@@@ SLUB %s: Freelist " |
647 | "cleared. Slab 0x%p\n", | |
648 | s->name, page); | |
81819f0f CL |
649 | return 0; |
650 | } | |
651 | break; | |
652 | } | |
653 | object = fp; | |
654 | fp = get_freepointer(s, object); | |
655 | nr++; | |
656 | } | |
657 | ||
658 | if (page->inuse != s->objects - nr) { | |
70d71228 CL |
659 | slab_err(s, page, "Wrong object count. Counter is %d but " |
660 | "counted were %d", s, page, page->inuse, | |
661 | s->objects - nr); | |
81819f0f | 662 | page->inuse = s->objects - nr; |
70d71228 CL |
663 | printk(KERN_ERR "@@@ SLUB %s: Object count adjusted. " |
664 | "Slab @0x%p\n", s->name, page); | |
81819f0f CL |
665 | } |
666 | return search == NULL; | |
667 | } | |
668 | ||
643b1138 CL |
669 | /* |
670 | * Tracking of fully allocated slabs for debugging | |
671 | */ | |
e95eed57 | 672 | static void add_full(struct kmem_cache_node *n, struct page *page) |
643b1138 | 673 | { |
643b1138 CL |
674 | spin_lock(&n->list_lock); |
675 | list_add(&page->lru, &n->full); | |
676 | spin_unlock(&n->list_lock); | |
677 | } | |
678 | ||
679 | static void remove_full(struct kmem_cache *s, struct page *page) | |
680 | { | |
681 | struct kmem_cache_node *n; | |
682 | ||
683 | if (!(s->flags & SLAB_STORE_USER)) | |
684 | return; | |
685 | ||
686 | n = get_node(s, page_to_nid(page)); | |
687 | ||
688 | spin_lock(&n->list_lock); | |
689 | list_del(&page->lru); | |
690 | spin_unlock(&n->list_lock); | |
691 | } | |
692 | ||
81819f0f CL |
693 | static int alloc_object_checks(struct kmem_cache *s, struct page *page, |
694 | void *object) | |
695 | { | |
696 | if (!check_slab(s, page)) | |
697 | goto bad; | |
698 | ||
699 | if (object && !on_freelist(s, page, object)) { | |
70d71228 CL |
700 | slab_err(s, page, "Object 0x%p already allocated", object); |
701 | goto bad; | |
81819f0f CL |
702 | } |
703 | ||
704 | if (!check_valid_pointer(s, page, object)) { | |
705 | object_err(s, page, object, "Freelist Pointer check fails"); | |
70d71228 | 706 | goto bad; |
81819f0f CL |
707 | } |
708 | ||
709 | if (!object) | |
710 | return 1; | |
711 | ||
712 | if (!check_object(s, page, object, 0)) | |
713 | goto bad; | |
81819f0f | 714 | |
81819f0f | 715 | return 1; |
81819f0f CL |
716 | bad: |
717 | if (PageSlab(page)) { | |
718 | /* | |
719 | * If this is a slab page then lets do the best we can | |
720 | * to avoid issues in the future. Marking all objects | |
721 | * as used avoids touching the remainder. | |
722 | */ | |
723 | printk(KERN_ERR "@@@ SLUB: %s slab 0x%p. Marking all objects used.\n", | |
724 | s->name, page); | |
725 | page->inuse = s->objects; | |
726 | page->freelist = NULL; | |
727 | /* Fix up fields that may be corrupted */ | |
728 | page->offset = s->offset / sizeof(void *); | |
729 | } | |
730 | return 0; | |
731 | } | |
732 | ||
733 | static int free_object_checks(struct kmem_cache *s, struct page *page, | |
734 | void *object) | |
735 | { | |
736 | if (!check_slab(s, page)) | |
737 | goto fail; | |
738 | ||
739 | if (!check_valid_pointer(s, page, object)) { | |
70d71228 | 740 | slab_err(s, page, "Invalid object pointer 0x%p", object); |
81819f0f CL |
741 | goto fail; |
742 | } | |
743 | ||
744 | if (on_freelist(s, page, object)) { | |
70d71228 | 745 | slab_err(s, page, "Object 0x%p already free", object); |
81819f0f CL |
746 | goto fail; |
747 | } | |
748 | ||
749 | if (!check_object(s, page, object, 1)) | |
750 | return 0; | |
751 | ||
752 | if (unlikely(s != page->slab)) { | |
753 | if (!PageSlab(page)) | |
70d71228 CL |
754 | slab_err(s, page, "Attempt to free object(0x%p) " |
755 | "outside of slab", object); | |
81819f0f | 756 | else |
70d71228 | 757 | if (!page->slab) { |
81819f0f | 758 | printk(KERN_ERR |
70d71228 | 759 | "SLUB <none>: no slab for object 0x%p.\n", |
81819f0f | 760 | object); |
70d71228 CL |
761 | dump_stack(); |
762 | } | |
81819f0f | 763 | else |
70d71228 CL |
764 | slab_err(s, page, "object at 0x%p belongs " |
765 | "to slab %s", object, page->slab->name); | |
81819f0f CL |
766 | goto fail; |
767 | } | |
81819f0f CL |
768 | return 1; |
769 | fail: | |
81819f0f CL |
770 | printk(KERN_ERR "@@@ SLUB: %s slab 0x%p object at 0x%p not freed.\n", |
771 | s->name, page, object); | |
772 | return 0; | |
773 | } | |
774 | ||
775 | /* | |
776 | * Slab allocation and freeing | |
777 | */ | |
778 | static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) | |
779 | { | |
780 | struct page * page; | |
781 | int pages = 1 << s->order; | |
782 | ||
783 | if (s->order) | |
784 | flags |= __GFP_COMP; | |
785 | ||
786 | if (s->flags & SLAB_CACHE_DMA) | |
787 | flags |= SLUB_DMA; | |
788 | ||
789 | if (node == -1) | |
790 | page = alloc_pages(flags, s->order); | |
791 | else | |
792 | page = alloc_pages_node(node, flags, s->order); | |
793 | ||
794 | if (!page) | |
795 | return NULL; | |
796 | ||
797 | mod_zone_page_state(page_zone(page), | |
798 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? | |
799 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, | |
800 | pages); | |
801 | ||
802 | return page; | |
803 | } | |
804 | ||
805 | static void setup_object(struct kmem_cache *s, struct page *page, | |
806 | void *object) | |
807 | { | |
808 | if (PageError(page)) { | |
809 | init_object(s, object, 0); | |
810 | init_tracking(s, object); | |
811 | } | |
812 | ||
813 | if (unlikely(s->ctor)) { | |
814 | int mode = SLAB_CTOR_CONSTRUCTOR; | |
815 | ||
816 | if (!(s->flags & __GFP_WAIT)) | |
817 | mode |= SLAB_CTOR_ATOMIC; | |
818 | ||
819 | s->ctor(object, s, mode); | |
820 | } | |
821 | } | |
822 | ||
823 | static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) | |
824 | { | |
825 | struct page *page; | |
826 | struct kmem_cache_node *n; | |
827 | void *start; | |
828 | void *end; | |
829 | void *last; | |
830 | void *p; | |
831 | ||
832 | if (flags & __GFP_NO_GROW) | |
833 | return NULL; | |
834 | ||
835 | BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK)); | |
836 | ||
837 | if (flags & __GFP_WAIT) | |
838 | local_irq_enable(); | |
839 | ||
840 | page = allocate_slab(s, flags & GFP_LEVEL_MASK, node); | |
841 | if (!page) | |
842 | goto out; | |
843 | ||
844 | n = get_node(s, page_to_nid(page)); | |
845 | if (n) | |
846 | atomic_long_inc(&n->nr_slabs); | |
847 | page->offset = s->offset / sizeof(void *); | |
848 | page->slab = s; | |
849 | page->flags |= 1 << PG_slab; | |
850 | if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON | | |
851 | SLAB_STORE_USER | SLAB_TRACE)) | |
852 | page->flags |= 1 << PG_error; | |
853 | ||
854 | start = page_address(page); | |
855 | end = start + s->objects * s->size; | |
856 | ||
857 | if (unlikely(s->flags & SLAB_POISON)) | |
858 | memset(start, POISON_INUSE, PAGE_SIZE << s->order); | |
859 | ||
860 | last = start; | |
861 | for (p = start + s->size; p < end; p += s->size) { | |
862 | setup_object(s, page, last); | |
863 | set_freepointer(s, last, p); | |
864 | last = p; | |
865 | } | |
866 | setup_object(s, page, last); | |
867 | set_freepointer(s, last, NULL); | |
868 | ||
869 | page->freelist = start; | |
870 | page->inuse = 0; | |
871 | out: | |
872 | if (flags & __GFP_WAIT) | |
873 | local_irq_disable(); | |
874 | return page; | |
875 | } | |
876 | ||
877 | static void __free_slab(struct kmem_cache *s, struct page *page) | |
878 | { | |
879 | int pages = 1 << s->order; | |
880 | ||
881 | if (unlikely(PageError(page) || s->dtor)) { | |
882 | void *start = page_address(page); | |
883 | void *end = start + (pages << PAGE_SHIFT); | |
884 | void *p; | |
885 | ||
886 | slab_pad_check(s, page); | |
887 | for (p = start; p <= end - s->size; p += s->size) { | |
888 | if (s->dtor) | |
889 | s->dtor(p, s, 0); | |
890 | check_object(s, page, p, 0); | |
891 | } | |
892 | } | |
893 | ||
894 | mod_zone_page_state(page_zone(page), | |
895 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? | |
896 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, | |
897 | - pages); | |
898 | ||
899 | page->mapping = NULL; | |
900 | __free_pages(page, s->order); | |
901 | } | |
902 | ||
903 | static void rcu_free_slab(struct rcu_head *h) | |
904 | { | |
905 | struct page *page; | |
906 | ||
907 | page = container_of((struct list_head *)h, struct page, lru); | |
908 | __free_slab(page->slab, page); | |
909 | } | |
910 | ||
911 | static void free_slab(struct kmem_cache *s, struct page *page) | |
912 | { | |
913 | if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { | |
914 | /* | |
915 | * RCU free overloads the RCU head over the LRU | |
916 | */ | |
917 | struct rcu_head *head = (void *)&page->lru; | |
918 | ||
919 | call_rcu(head, rcu_free_slab); | |
920 | } else | |
921 | __free_slab(s, page); | |
922 | } | |
923 | ||
924 | static void discard_slab(struct kmem_cache *s, struct page *page) | |
925 | { | |
926 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); | |
927 | ||
928 | atomic_long_dec(&n->nr_slabs); | |
929 | reset_page_mapcount(page); | |
930 | page->flags &= ~(1 << PG_slab | 1 << PG_error); | |
931 | free_slab(s, page); | |
932 | } | |
933 | ||
934 | /* | |
935 | * Per slab locking using the pagelock | |
936 | */ | |
937 | static __always_inline void slab_lock(struct page *page) | |
938 | { | |
939 | bit_spin_lock(PG_locked, &page->flags); | |
940 | } | |
941 | ||
942 | static __always_inline void slab_unlock(struct page *page) | |
943 | { | |
944 | bit_spin_unlock(PG_locked, &page->flags); | |
945 | } | |
946 | ||
947 | static __always_inline int slab_trylock(struct page *page) | |
948 | { | |
949 | int rc = 1; | |
950 | ||
951 | rc = bit_spin_trylock(PG_locked, &page->flags); | |
952 | return rc; | |
953 | } | |
954 | ||
955 | /* | |
956 | * Management of partially allocated slabs | |
957 | */ | |
e95eed57 | 958 | static void add_partial_tail(struct kmem_cache_node *n, struct page *page) |
81819f0f | 959 | { |
e95eed57 CL |
960 | spin_lock(&n->list_lock); |
961 | n->nr_partial++; | |
962 | list_add_tail(&page->lru, &n->partial); | |
963 | spin_unlock(&n->list_lock); | |
964 | } | |
81819f0f | 965 | |
e95eed57 CL |
966 | static void add_partial(struct kmem_cache_node *n, struct page *page) |
967 | { | |
81819f0f CL |
968 | spin_lock(&n->list_lock); |
969 | n->nr_partial++; | |
970 | list_add(&page->lru, &n->partial); | |
971 | spin_unlock(&n->list_lock); | |
972 | } | |
973 | ||
974 | static void remove_partial(struct kmem_cache *s, | |
975 | struct page *page) | |
976 | { | |
977 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); | |
978 | ||
979 | spin_lock(&n->list_lock); | |
980 | list_del(&page->lru); | |
981 | n->nr_partial--; | |
982 | spin_unlock(&n->list_lock); | |
983 | } | |
984 | ||
985 | /* | |
986 | * Lock page and remove it from the partial list | |
987 | * | |
988 | * Must hold list_lock | |
989 | */ | |
990 | static int lock_and_del_slab(struct kmem_cache_node *n, struct page *page) | |
991 | { | |
992 | if (slab_trylock(page)) { | |
993 | list_del(&page->lru); | |
994 | n->nr_partial--; | |
995 | return 1; | |
996 | } | |
997 | return 0; | |
998 | } | |
999 | ||
1000 | /* | |
1001 | * Try to get a partial slab from a specific node | |
1002 | */ | |
1003 | static struct page *get_partial_node(struct kmem_cache_node *n) | |
1004 | { | |
1005 | struct page *page; | |
1006 | ||
1007 | /* | |
1008 | * Racy check. If we mistakenly see no partial slabs then we | |
1009 | * just allocate an empty slab. If we mistakenly try to get a | |
1010 | * partial slab then get_partials() will return NULL. | |
1011 | */ | |
1012 | if (!n || !n->nr_partial) | |
1013 | return NULL; | |
1014 | ||
1015 | spin_lock(&n->list_lock); | |
1016 | list_for_each_entry(page, &n->partial, lru) | |
1017 | if (lock_and_del_slab(n, page)) | |
1018 | goto out; | |
1019 | page = NULL; | |
1020 | out: | |
1021 | spin_unlock(&n->list_lock); | |
1022 | return page; | |
1023 | } | |
1024 | ||
1025 | /* | |
1026 | * Get a page from somewhere. Search in increasing NUMA | |
1027 | * distances. | |
1028 | */ | |
1029 | static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags) | |
1030 | { | |
1031 | #ifdef CONFIG_NUMA | |
1032 | struct zonelist *zonelist; | |
1033 | struct zone **z; | |
1034 | struct page *page; | |
1035 | ||
1036 | /* | |
1037 | * The defrag ratio allows to configure the tradeoffs between | |
1038 | * inter node defragmentation and node local allocations. | |
1039 | * A lower defrag_ratio increases the tendency to do local | |
1040 | * allocations instead of scanning throught the partial | |
1041 | * lists on other nodes. | |
1042 | * | |
1043 | * If defrag_ratio is set to 0 then kmalloc() always | |
1044 | * returns node local objects. If its higher then kmalloc() | |
1045 | * may return off node objects in order to avoid fragmentation. | |
1046 | * | |
1047 | * A higher ratio means slabs may be taken from other nodes | |
1048 | * thus reducing the number of partial slabs on those nodes. | |
1049 | * | |
1050 | * If /sys/slab/xx/defrag_ratio is set to 100 (which makes | |
1051 | * defrag_ratio = 1000) then every (well almost) allocation | |
1052 | * will first attempt to defrag slab caches on other nodes. This | |
1053 | * means scanning over all nodes to look for partial slabs which | |
1054 | * may be a bit expensive to do on every slab allocation. | |
1055 | */ | |
1056 | if (!s->defrag_ratio || get_cycles() % 1024 > s->defrag_ratio) | |
1057 | return NULL; | |
1058 | ||
1059 | zonelist = &NODE_DATA(slab_node(current->mempolicy)) | |
1060 | ->node_zonelists[gfp_zone(flags)]; | |
1061 | for (z = zonelist->zones; *z; z++) { | |
1062 | struct kmem_cache_node *n; | |
1063 | ||
1064 | n = get_node(s, zone_to_nid(*z)); | |
1065 | ||
1066 | if (n && cpuset_zone_allowed_hardwall(*z, flags) && | |
e95eed57 | 1067 | n->nr_partial > MIN_PARTIAL) { |
81819f0f CL |
1068 | page = get_partial_node(n); |
1069 | if (page) | |
1070 | return page; | |
1071 | } | |
1072 | } | |
1073 | #endif | |
1074 | return NULL; | |
1075 | } | |
1076 | ||
1077 | /* | |
1078 | * Get a partial page, lock it and return it. | |
1079 | */ | |
1080 | static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) | |
1081 | { | |
1082 | struct page *page; | |
1083 | int searchnode = (node == -1) ? numa_node_id() : node; | |
1084 | ||
1085 | page = get_partial_node(get_node(s, searchnode)); | |
1086 | if (page || (flags & __GFP_THISNODE)) | |
1087 | return page; | |
1088 | ||
1089 | return get_any_partial(s, flags); | |
1090 | } | |
1091 | ||
1092 | /* | |
1093 | * Move a page back to the lists. | |
1094 | * | |
1095 | * Must be called with the slab lock held. | |
1096 | * | |
1097 | * On exit the slab lock will have been dropped. | |
1098 | */ | |
1099 | static void putback_slab(struct kmem_cache *s, struct page *page) | |
1100 | { | |
e95eed57 CL |
1101 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); |
1102 | ||
81819f0f | 1103 | if (page->inuse) { |
e95eed57 | 1104 | |
81819f0f | 1105 | if (page->freelist) |
e95eed57 CL |
1106 | add_partial(n, page); |
1107 | else if (PageError(page) && (s->flags & SLAB_STORE_USER)) | |
1108 | add_full(n, page); | |
81819f0f | 1109 | slab_unlock(page); |
e95eed57 | 1110 | |
81819f0f | 1111 | } else { |
e95eed57 CL |
1112 | if (n->nr_partial < MIN_PARTIAL) { |
1113 | /* | |
1114 | * Adding an empty page to the partial slabs in order | |
1115 | * to avoid page allocator overhead. This page needs to | |
1116 | * come after all the others that are not fully empty | |
1117 | * in order to make sure that we do maximum | |
1118 | * defragmentation. | |
1119 | */ | |
1120 | add_partial_tail(n, page); | |
1121 | slab_unlock(page); | |
1122 | } else { | |
1123 | slab_unlock(page); | |
1124 | discard_slab(s, page); | |
1125 | } | |
81819f0f CL |
1126 | } |
1127 | } | |
1128 | ||
1129 | /* | |
1130 | * Remove the cpu slab | |
1131 | */ | |
1132 | static void deactivate_slab(struct kmem_cache *s, struct page *page, int cpu) | |
1133 | { | |
1134 | s->cpu_slab[cpu] = NULL; | |
1135 | ClearPageActive(page); | |
1136 | ||
1137 | putback_slab(s, page); | |
1138 | } | |
1139 | ||
1140 | static void flush_slab(struct kmem_cache *s, struct page *page, int cpu) | |
1141 | { | |
1142 | slab_lock(page); | |
1143 | deactivate_slab(s, page, cpu); | |
1144 | } | |
1145 | ||
1146 | /* | |
1147 | * Flush cpu slab. | |
1148 | * Called from IPI handler with interrupts disabled. | |
1149 | */ | |
1150 | static void __flush_cpu_slab(struct kmem_cache *s, int cpu) | |
1151 | { | |
1152 | struct page *page = s->cpu_slab[cpu]; | |
1153 | ||
1154 | if (likely(page)) | |
1155 | flush_slab(s, page, cpu); | |
1156 | } | |
1157 | ||
1158 | static void flush_cpu_slab(void *d) | |
1159 | { | |
1160 | struct kmem_cache *s = d; | |
1161 | int cpu = smp_processor_id(); | |
1162 | ||
1163 | __flush_cpu_slab(s, cpu); | |
1164 | } | |
1165 | ||
1166 | static void flush_all(struct kmem_cache *s) | |
1167 | { | |
1168 | #ifdef CONFIG_SMP | |
1169 | on_each_cpu(flush_cpu_slab, s, 1, 1); | |
1170 | #else | |
1171 | unsigned long flags; | |
1172 | ||
1173 | local_irq_save(flags); | |
1174 | flush_cpu_slab(s); | |
1175 | local_irq_restore(flags); | |
1176 | #endif | |
1177 | } | |
1178 | ||
1179 | /* | |
1180 | * slab_alloc is optimized to only modify two cachelines on the fast path | |
1181 | * (aside from the stack): | |
1182 | * | |
1183 | * 1. The page struct | |
1184 | * 2. The first cacheline of the object to be allocated. | |
1185 | * | |
1186 | * The only cache lines that are read (apart from code) is the | |
1187 | * per cpu array in the kmem_cache struct. | |
1188 | * | |
1189 | * Fastpath is not possible if we need to get a new slab or have | |
1190 | * debugging enabled (which means all slabs are marked with PageError) | |
1191 | */ | |
77c5e2d0 CL |
1192 | static void *slab_alloc(struct kmem_cache *s, |
1193 | gfp_t gfpflags, int node, void *addr) | |
81819f0f CL |
1194 | { |
1195 | struct page *page; | |
1196 | void **object; | |
1197 | unsigned long flags; | |
1198 | int cpu; | |
1199 | ||
1200 | local_irq_save(flags); | |
1201 | cpu = smp_processor_id(); | |
1202 | page = s->cpu_slab[cpu]; | |
1203 | if (!page) | |
1204 | goto new_slab; | |
1205 | ||
1206 | slab_lock(page); | |
1207 | if (unlikely(node != -1 && page_to_nid(page) != node)) | |
1208 | goto another_slab; | |
1209 | redo: | |
1210 | object = page->freelist; | |
1211 | if (unlikely(!object)) | |
1212 | goto another_slab; | |
1213 | if (unlikely(PageError(page))) | |
1214 | goto debug; | |
1215 | ||
1216 | have_object: | |
1217 | page->inuse++; | |
1218 | page->freelist = object[page->offset]; | |
1219 | slab_unlock(page); | |
1220 | local_irq_restore(flags); | |
1221 | return object; | |
1222 | ||
1223 | another_slab: | |
1224 | deactivate_slab(s, page, cpu); | |
1225 | ||
1226 | new_slab: | |
1227 | page = get_partial(s, gfpflags, node); | |
1228 | if (likely(page)) { | |
1229 | have_slab: | |
1230 | s->cpu_slab[cpu] = page; | |
1231 | SetPageActive(page); | |
1232 | goto redo; | |
1233 | } | |
1234 | ||
1235 | page = new_slab(s, gfpflags, node); | |
1236 | if (page) { | |
1237 | cpu = smp_processor_id(); | |
1238 | if (s->cpu_slab[cpu]) { | |
1239 | /* | |
1240 | * Someone else populated the cpu_slab while we enabled | |
1241 | * interrupts, or we have got scheduled on another cpu. | |
1242 | * The page may not be on the requested node. | |
1243 | */ | |
1244 | if (node == -1 || | |
1245 | page_to_nid(s->cpu_slab[cpu]) == node) { | |
1246 | /* | |
1247 | * Current cpuslab is acceptable and we | |
1248 | * want the current one since its cache hot | |
1249 | */ | |
1250 | discard_slab(s, page); | |
1251 | page = s->cpu_slab[cpu]; | |
1252 | slab_lock(page); | |
1253 | goto redo; | |
1254 | } | |
1255 | /* Dump the current slab */ | |
1256 | flush_slab(s, s->cpu_slab[cpu], cpu); | |
1257 | } | |
1258 | slab_lock(page); | |
1259 | goto have_slab; | |
1260 | } | |
1261 | local_irq_restore(flags); | |
1262 | return NULL; | |
1263 | debug: | |
1264 | if (!alloc_object_checks(s, page, object)) | |
1265 | goto another_slab; | |
1266 | if (s->flags & SLAB_STORE_USER) | |
77c5e2d0 | 1267 | set_track(s, object, TRACK_ALLOC, addr); |
70d71228 CL |
1268 | if (s->flags & SLAB_TRACE) { |
1269 | printk(KERN_INFO "TRACE %s alloc 0x%p inuse=%d fp=0x%p\n", | |
1270 | s->name, object, page->inuse, | |
1271 | page->freelist); | |
1272 | dump_stack(); | |
1273 | } | |
1274 | init_object(s, object, 1); | |
81819f0f CL |
1275 | goto have_object; |
1276 | } | |
1277 | ||
1278 | void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) | |
1279 | { | |
77c5e2d0 | 1280 | return slab_alloc(s, gfpflags, -1, __builtin_return_address(0)); |
81819f0f CL |
1281 | } |
1282 | EXPORT_SYMBOL(kmem_cache_alloc); | |
1283 | ||
1284 | #ifdef CONFIG_NUMA | |
1285 | void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node) | |
1286 | { | |
77c5e2d0 | 1287 | return slab_alloc(s, gfpflags, node, __builtin_return_address(0)); |
81819f0f CL |
1288 | } |
1289 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
1290 | #endif | |
1291 | ||
1292 | /* | |
1293 | * The fastpath only writes the cacheline of the page struct and the first | |
1294 | * cacheline of the object. | |
1295 | * | |
1296 | * No special cachelines need to be read | |
1297 | */ | |
77c5e2d0 CL |
1298 | static void slab_free(struct kmem_cache *s, struct page *page, |
1299 | void *x, void *addr) | |
81819f0f CL |
1300 | { |
1301 | void *prior; | |
1302 | void **object = (void *)x; | |
1303 | unsigned long flags; | |
1304 | ||
1305 | local_irq_save(flags); | |
1306 | slab_lock(page); | |
1307 | ||
1308 | if (unlikely(PageError(page))) | |
1309 | goto debug; | |
1310 | checks_ok: | |
1311 | prior = object[page->offset] = page->freelist; | |
1312 | page->freelist = object; | |
1313 | page->inuse--; | |
1314 | ||
1315 | if (unlikely(PageActive(page))) | |
1316 | /* | |
1317 | * Cpu slabs are never on partial lists and are | |
1318 | * never freed. | |
1319 | */ | |
1320 | goto out_unlock; | |
1321 | ||
1322 | if (unlikely(!page->inuse)) | |
1323 | goto slab_empty; | |
1324 | ||
1325 | /* | |
1326 | * Objects left in the slab. If it | |
1327 | * was not on the partial list before | |
1328 | * then add it. | |
1329 | */ | |
1330 | if (unlikely(!prior)) | |
e95eed57 | 1331 | add_partial(get_node(s, page_to_nid(page)), page); |
81819f0f CL |
1332 | |
1333 | out_unlock: | |
1334 | slab_unlock(page); | |
1335 | local_irq_restore(flags); | |
1336 | return; | |
1337 | ||
1338 | slab_empty: | |
1339 | if (prior) | |
1340 | /* | |
643b1138 | 1341 | * Slab on the partial list. |
81819f0f CL |
1342 | */ |
1343 | remove_partial(s, page); | |
1344 | ||
1345 | slab_unlock(page); | |
1346 | discard_slab(s, page); | |
1347 | local_irq_restore(flags); | |
1348 | return; | |
1349 | ||
1350 | debug: | |
77c5e2d0 CL |
1351 | if (!free_object_checks(s, page, x)) |
1352 | goto out_unlock; | |
643b1138 CL |
1353 | if (!PageActive(page) && !page->freelist) |
1354 | remove_full(s, page); | |
77c5e2d0 CL |
1355 | if (s->flags & SLAB_STORE_USER) |
1356 | set_track(s, x, TRACK_FREE, addr); | |
70d71228 CL |
1357 | if (s->flags & SLAB_TRACE) { |
1358 | printk(KERN_INFO "TRACE %s free 0x%p inuse=%d fp=0x%p\n", | |
1359 | s->name, object, page->inuse, | |
1360 | page->freelist); | |
1361 | print_section("Object", (void *)object, s->objsize); | |
1362 | dump_stack(); | |
1363 | } | |
1364 | init_object(s, object, 0); | |
77c5e2d0 | 1365 | goto checks_ok; |
81819f0f CL |
1366 | } |
1367 | ||
1368 | void kmem_cache_free(struct kmem_cache *s, void *x) | |
1369 | { | |
77c5e2d0 | 1370 | struct page *page; |
81819f0f | 1371 | |
b49af68f | 1372 | page = virt_to_head_page(x); |
81819f0f | 1373 | |
77c5e2d0 | 1374 | slab_free(s, page, x, __builtin_return_address(0)); |
81819f0f CL |
1375 | } |
1376 | EXPORT_SYMBOL(kmem_cache_free); | |
1377 | ||
1378 | /* Figure out on which slab object the object resides */ | |
1379 | static struct page *get_object_page(const void *x) | |
1380 | { | |
b49af68f | 1381 | struct page *page = virt_to_head_page(x); |
81819f0f CL |
1382 | |
1383 | if (!PageSlab(page)) | |
1384 | return NULL; | |
1385 | ||
1386 | return page; | |
1387 | } | |
1388 | ||
1389 | /* | |
1390 | * kmem_cache_open produces objects aligned at "size" and the first object | |
1391 | * is placed at offset 0 in the slab (We have no metainformation on the | |
1392 | * slab, all slabs are in essence "off slab"). | |
1393 | * | |
1394 | * In order to get the desired alignment one just needs to align the | |
1395 | * size. | |
1396 | * | |
1397 | * Notice that the allocation order determines the sizes of the per cpu | |
1398 | * caches. Each processor has always one slab available for allocations. | |
1399 | * Increasing the allocation order reduces the number of times that slabs | |
1400 | * must be moved on and off the partial lists and therefore may influence | |
1401 | * locking overhead. | |
1402 | * | |
1403 | * The offset is used to relocate the free list link in each object. It is | |
1404 | * therefore possible to move the free list link behind the object. This | |
1405 | * is necessary for RCU to work properly and also useful for debugging. | |
1406 | */ | |
1407 | ||
1408 | /* | |
1409 | * Mininum / Maximum order of slab pages. This influences locking overhead | |
1410 | * and slab fragmentation. A higher order reduces the number of partial slabs | |
1411 | * and increases the number of allocations possible without having to | |
1412 | * take the list_lock. | |
1413 | */ | |
1414 | static int slub_min_order; | |
1415 | static int slub_max_order = DEFAULT_MAX_ORDER; | |
1416 | ||
1417 | /* | |
1418 | * Minimum number of objects per slab. This is necessary in order to | |
1419 | * reduce locking overhead. Similar to the queue size in SLAB. | |
1420 | */ | |
1421 | static int slub_min_objects = DEFAULT_MIN_OBJECTS; | |
1422 | ||
1423 | /* | |
1424 | * Merge control. If this is set then no merging of slab caches will occur. | |
1425 | */ | |
1426 | static int slub_nomerge; | |
1427 | ||
1428 | /* | |
1429 | * Debug settings: | |
1430 | */ | |
1431 | static int slub_debug; | |
1432 | ||
1433 | static char *slub_debug_slabs; | |
1434 | ||
1435 | /* | |
1436 | * Calculate the order of allocation given an slab object size. | |
1437 | * | |
1438 | * The order of allocation has significant impact on other elements | |
1439 | * of the system. Generally order 0 allocations should be preferred | |
1440 | * since they do not cause fragmentation in the page allocator. Larger | |
1441 | * objects may have problems with order 0 because there may be too much | |
1442 | * space left unused in a slab. We go to a higher order if more than 1/8th | |
1443 | * of the slab would be wasted. | |
1444 | * | |
1445 | * In order to reach satisfactory performance we must ensure that | |
1446 | * a minimum number of objects is in one slab. Otherwise we may | |
1447 | * generate too much activity on the partial lists. This is less a | |
1448 | * concern for large slabs though. slub_max_order specifies the order | |
1449 | * where we begin to stop considering the number of objects in a slab. | |
1450 | * | |
1451 | * Higher order allocations also allow the placement of more objects | |
1452 | * in a slab and thereby reduce object handling overhead. If the user | |
1453 | * has requested a higher mininum order then we start with that one | |
1454 | * instead of zero. | |
1455 | */ | |
1456 | static int calculate_order(int size) | |
1457 | { | |
1458 | int order; | |
1459 | int rem; | |
1460 | ||
1461 | for (order = max(slub_min_order, fls(size - 1) - PAGE_SHIFT); | |
1462 | order < MAX_ORDER; order++) { | |
1463 | unsigned long slab_size = PAGE_SIZE << order; | |
1464 | ||
1465 | if (slub_max_order > order && | |
1466 | slab_size < slub_min_objects * size) | |
1467 | continue; | |
1468 | ||
1469 | if (slab_size < size) | |
1470 | continue; | |
1471 | ||
1472 | rem = slab_size % size; | |
1473 | ||
1474 | if (rem <= (PAGE_SIZE << order) / 8) | |
1475 | break; | |
1476 | ||
1477 | } | |
1478 | if (order >= MAX_ORDER) | |
1479 | return -E2BIG; | |
1480 | return order; | |
1481 | } | |
1482 | ||
1483 | /* | |
1484 | * Function to figure out which alignment to use from the | |
1485 | * various ways of specifying it. | |
1486 | */ | |
1487 | static unsigned long calculate_alignment(unsigned long flags, | |
1488 | unsigned long align, unsigned long size) | |
1489 | { | |
1490 | /* | |
1491 | * If the user wants hardware cache aligned objects then | |
1492 | * follow that suggestion if the object is sufficiently | |
1493 | * large. | |
1494 | * | |
1495 | * The hardware cache alignment cannot override the | |
1496 | * specified alignment though. If that is greater | |
1497 | * then use it. | |
1498 | */ | |
5af60839 | 1499 | if ((flags & SLAB_HWCACHE_ALIGN) && |
81819f0f CL |
1500 | size > L1_CACHE_BYTES / 2) |
1501 | return max_t(unsigned long, align, L1_CACHE_BYTES); | |
1502 | ||
1503 | if (align < ARCH_SLAB_MINALIGN) | |
1504 | return ARCH_SLAB_MINALIGN; | |
1505 | ||
1506 | return ALIGN(align, sizeof(void *)); | |
1507 | } | |
1508 | ||
1509 | static void init_kmem_cache_node(struct kmem_cache_node *n) | |
1510 | { | |
1511 | n->nr_partial = 0; | |
1512 | atomic_long_set(&n->nr_slabs, 0); | |
1513 | spin_lock_init(&n->list_lock); | |
1514 | INIT_LIST_HEAD(&n->partial); | |
643b1138 | 1515 | INIT_LIST_HEAD(&n->full); |
81819f0f CL |
1516 | } |
1517 | ||
1518 | #ifdef CONFIG_NUMA | |
1519 | /* | |
1520 | * No kmalloc_node yet so do it by hand. We know that this is the first | |
1521 | * slab on the node for this slabcache. There are no concurrent accesses | |
1522 | * possible. | |
1523 | * | |
1524 | * Note that this function only works on the kmalloc_node_cache | |
1525 | * when allocating for the kmalloc_node_cache. | |
1526 | */ | |
1527 | static struct kmem_cache_node * __init early_kmem_cache_node_alloc(gfp_t gfpflags, | |
1528 | int node) | |
1529 | { | |
1530 | struct page *page; | |
1531 | struct kmem_cache_node *n; | |
1532 | ||
1533 | BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node)); | |
1534 | ||
1535 | page = new_slab(kmalloc_caches, gfpflags | GFP_THISNODE, node); | |
1536 | /* new_slab() disables interupts */ | |
1537 | local_irq_enable(); | |
1538 | ||
1539 | BUG_ON(!page); | |
1540 | n = page->freelist; | |
1541 | BUG_ON(!n); | |
1542 | page->freelist = get_freepointer(kmalloc_caches, n); | |
1543 | page->inuse++; | |
1544 | kmalloc_caches->node[node] = n; | |
1545 | init_object(kmalloc_caches, n, 1); | |
1546 | init_kmem_cache_node(n); | |
1547 | atomic_long_inc(&n->nr_slabs); | |
e95eed57 | 1548 | add_partial(n, page); |
81819f0f CL |
1549 | return n; |
1550 | } | |
1551 | ||
1552 | static void free_kmem_cache_nodes(struct kmem_cache *s) | |
1553 | { | |
1554 | int node; | |
1555 | ||
1556 | for_each_online_node(node) { | |
1557 | struct kmem_cache_node *n = s->node[node]; | |
1558 | if (n && n != &s->local_node) | |
1559 | kmem_cache_free(kmalloc_caches, n); | |
1560 | s->node[node] = NULL; | |
1561 | } | |
1562 | } | |
1563 | ||
1564 | static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) | |
1565 | { | |
1566 | int node; | |
1567 | int local_node; | |
1568 | ||
1569 | if (slab_state >= UP) | |
1570 | local_node = page_to_nid(virt_to_page(s)); | |
1571 | else | |
1572 | local_node = 0; | |
1573 | ||
1574 | for_each_online_node(node) { | |
1575 | struct kmem_cache_node *n; | |
1576 | ||
1577 | if (local_node == node) | |
1578 | n = &s->local_node; | |
1579 | else { | |
1580 | if (slab_state == DOWN) { | |
1581 | n = early_kmem_cache_node_alloc(gfpflags, | |
1582 | node); | |
1583 | continue; | |
1584 | } | |
1585 | n = kmem_cache_alloc_node(kmalloc_caches, | |
1586 | gfpflags, node); | |
1587 | ||
1588 | if (!n) { | |
1589 | free_kmem_cache_nodes(s); | |
1590 | return 0; | |
1591 | } | |
1592 | ||
1593 | } | |
1594 | s->node[node] = n; | |
1595 | init_kmem_cache_node(n); | |
1596 | } | |
1597 | return 1; | |
1598 | } | |
1599 | #else | |
1600 | static void free_kmem_cache_nodes(struct kmem_cache *s) | |
1601 | { | |
1602 | } | |
1603 | ||
1604 | static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) | |
1605 | { | |
1606 | init_kmem_cache_node(&s->local_node); | |
1607 | return 1; | |
1608 | } | |
1609 | #endif | |
1610 | ||
1611 | /* | |
1612 | * calculate_sizes() determines the order and the distribution of data within | |
1613 | * a slab object. | |
1614 | */ | |
1615 | static int calculate_sizes(struct kmem_cache *s) | |
1616 | { | |
1617 | unsigned long flags = s->flags; | |
1618 | unsigned long size = s->objsize; | |
1619 | unsigned long align = s->align; | |
1620 | ||
1621 | /* | |
1622 | * Determine if we can poison the object itself. If the user of | |
1623 | * the slab may touch the object after free or before allocation | |
1624 | * then we should never poison the object itself. | |
1625 | */ | |
1626 | if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) && | |
1627 | !s->ctor && !s->dtor) | |
1628 | s->flags |= __OBJECT_POISON; | |
1629 | else | |
1630 | s->flags &= ~__OBJECT_POISON; | |
1631 | ||
1632 | /* | |
1633 | * Round up object size to the next word boundary. We can only | |
1634 | * place the free pointer at word boundaries and this determines | |
1635 | * the possible location of the free pointer. | |
1636 | */ | |
1637 | size = ALIGN(size, sizeof(void *)); | |
1638 | ||
1639 | /* | |
1640 | * If we are redzoning then check if there is some space between the | |
1641 | * end of the object and the free pointer. If not then add an | |
1642 | * additional word, so that we can establish a redzone between | |
1643 | * the object and the freepointer to be able to check for overwrites. | |
1644 | */ | |
1645 | if ((flags & SLAB_RED_ZONE) && size == s->objsize) | |
1646 | size += sizeof(void *); | |
1647 | ||
1648 | /* | |
1649 | * With that we have determined how much of the slab is in actual | |
1650 | * use by the object. This is the potential offset to the free | |
1651 | * pointer. | |
1652 | */ | |
1653 | s->inuse = size; | |
1654 | ||
1655 | if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || | |
1656 | s->ctor || s->dtor)) { | |
1657 | /* | |
1658 | * Relocate free pointer after the object if it is not | |
1659 | * permitted to overwrite the first word of the object on | |
1660 | * kmem_cache_free. | |
1661 | * | |
1662 | * This is the case if we do RCU, have a constructor or | |
1663 | * destructor or are poisoning the objects. | |
1664 | */ | |
1665 | s->offset = size; | |
1666 | size += sizeof(void *); | |
1667 | } | |
1668 | ||
1669 | if (flags & SLAB_STORE_USER) | |
1670 | /* | |
1671 | * Need to store information about allocs and frees after | |
1672 | * the object. | |
1673 | */ | |
1674 | size += 2 * sizeof(struct track); | |
1675 | ||
1676 | if (flags & DEBUG_DEFAULT_FLAGS) | |
1677 | /* | |
1678 | * Add some empty padding so that we can catch | |
1679 | * overwrites from earlier objects rather than let | |
1680 | * tracking information or the free pointer be | |
1681 | * corrupted if an user writes before the start | |
1682 | * of the object. | |
1683 | */ | |
1684 | size += sizeof(void *); | |
1685 | /* | |
1686 | * Determine the alignment based on various parameters that the | |
1687 | * user specified (this is unecessarily complex due to the attempt | |
1688 | * to be compatible with SLAB. Should be cleaned up some day). | |
1689 | */ | |
1690 | align = calculate_alignment(flags, align, s->objsize); | |
1691 | ||
1692 | /* | |
1693 | * SLUB stores one object immediately after another beginning from | |
1694 | * offset 0. In order to align the objects we have to simply size | |
1695 | * each object to conform to the alignment. | |
1696 | */ | |
1697 | size = ALIGN(size, align); | |
1698 | s->size = size; | |
1699 | ||
1700 | s->order = calculate_order(size); | |
1701 | if (s->order < 0) | |
1702 | return 0; | |
1703 | ||
1704 | /* | |
1705 | * Determine the number of objects per slab | |
1706 | */ | |
1707 | s->objects = (PAGE_SIZE << s->order) / size; | |
1708 | ||
1709 | /* | |
1710 | * Verify that the number of objects is within permitted limits. | |
1711 | * The page->inuse field is only 16 bit wide! So we cannot have | |
1712 | * more than 64k objects per slab. | |
1713 | */ | |
1714 | if (!s->objects || s->objects > 65535) | |
1715 | return 0; | |
1716 | return 1; | |
1717 | ||
1718 | } | |
1719 | ||
1720 | static int __init finish_bootstrap(void) | |
1721 | { | |
1722 | struct list_head *h; | |
1723 | int err; | |
1724 | ||
1725 | slab_state = SYSFS; | |
1726 | ||
1727 | list_for_each(h, &slab_caches) { | |
1728 | struct kmem_cache *s = | |
1729 | container_of(h, struct kmem_cache, list); | |
1730 | ||
1731 | err = sysfs_slab_add(s); | |
1732 | BUG_ON(err); | |
1733 | } | |
1734 | return 0; | |
1735 | } | |
1736 | ||
1737 | static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, | |
1738 | const char *name, size_t size, | |
1739 | size_t align, unsigned long flags, | |
1740 | void (*ctor)(void *, struct kmem_cache *, unsigned long), | |
1741 | void (*dtor)(void *, struct kmem_cache *, unsigned long)) | |
1742 | { | |
1743 | memset(s, 0, kmem_size); | |
1744 | s->name = name; | |
1745 | s->ctor = ctor; | |
1746 | s->dtor = dtor; | |
1747 | s->objsize = size; | |
1748 | s->flags = flags; | |
1749 | s->align = align; | |
1750 | ||
1751 | BUG_ON(flags & SLUB_UNIMPLEMENTED); | |
1752 | ||
1753 | /* | |
1754 | * The page->offset field is only 16 bit wide. This is an offset | |
1755 | * in units of words from the beginning of an object. If the slab | |
1756 | * size is bigger then we cannot move the free pointer behind the | |
1757 | * object anymore. | |
1758 | * | |
1759 | * On 32 bit platforms the limit is 256k. On 64bit platforms | |
1760 | * the limit is 512k. | |
1761 | * | |
1762 | * Debugging or ctor/dtors may create a need to move the free | |
1763 | * pointer. Fail if this happens. | |
1764 | */ | |
1765 | if (s->size >= 65535 * sizeof(void *)) { | |
1766 | BUG_ON(flags & (SLAB_RED_ZONE | SLAB_POISON | | |
1767 | SLAB_STORE_USER | SLAB_DESTROY_BY_RCU)); | |
1768 | BUG_ON(ctor || dtor); | |
1769 | } | |
1770 | else | |
1771 | /* | |
1772 | * Enable debugging if selected on the kernel commandline. | |
1773 | */ | |
1774 | if (slub_debug && (!slub_debug_slabs || | |
1775 | strncmp(slub_debug_slabs, name, | |
1776 | strlen(slub_debug_slabs)) == 0)) | |
1777 | s->flags |= slub_debug; | |
1778 | ||
1779 | if (!calculate_sizes(s)) | |
1780 | goto error; | |
1781 | ||
1782 | s->refcount = 1; | |
1783 | #ifdef CONFIG_NUMA | |
1784 | s->defrag_ratio = 100; | |
1785 | #endif | |
1786 | ||
1787 | if (init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA)) | |
1788 | return 1; | |
1789 | error: | |
1790 | if (flags & SLAB_PANIC) | |
1791 | panic("Cannot create slab %s size=%lu realsize=%u " | |
1792 | "order=%u offset=%u flags=%lx\n", | |
1793 | s->name, (unsigned long)size, s->size, s->order, | |
1794 | s->offset, flags); | |
1795 | return 0; | |
1796 | } | |
1797 | EXPORT_SYMBOL(kmem_cache_open); | |
1798 | ||
1799 | /* | |
1800 | * Check if a given pointer is valid | |
1801 | */ | |
1802 | int kmem_ptr_validate(struct kmem_cache *s, const void *object) | |
1803 | { | |
1804 | struct page * page; | |
1805 | void *addr; | |
1806 | ||
1807 | page = get_object_page(object); | |
1808 | ||
1809 | if (!page || s != page->slab) | |
1810 | /* No slab or wrong slab */ | |
1811 | return 0; | |
1812 | ||
1813 | addr = page_address(page); | |
1814 | if (object < addr || object >= addr + s->objects * s->size) | |
1815 | /* Out of bounds */ | |
1816 | return 0; | |
1817 | ||
1818 | if ((object - addr) % s->size) | |
1819 | /* Improperly aligned */ | |
1820 | return 0; | |
1821 | ||
1822 | /* | |
1823 | * We could also check if the object is on the slabs freelist. | |
1824 | * But this would be too expensive and it seems that the main | |
1825 | * purpose of kmem_ptr_valid is to check if the object belongs | |
1826 | * to a certain slab. | |
1827 | */ | |
1828 | return 1; | |
1829 | } | |
1830 | EXPORT_SYMBOL(kmem_ptr_validate); | |
1831 | ||
1832 | /* | |
1833 | * Determine the size of a slab object | |
1834 | */ | |
1835 | unsigned int kmem_cache_size(struct kmem_cache *s) | |
1836 | { | |
1837 | return s->objsize; | |
1838 | } | |
1839 | EXPORT_SYMBOL(kmem_cache_size); | |
1840 | ||
1841 | const char *kmem_cache_name(struct kmem_cache *s) | |
1842 | { | |
1843 | return s->name; | |
1844 | } | |
1845 | EXPORT_SYMBOL(kmem_cache_name); | |
1846 | ||
1847 | /* | |
1848 | * Attempt to free all slabs on a node | |
1849 | */ | |
1850 | static int free_list(struct kmem_cache *s, struct kmem_cache_node *n, | |
1851 | struct list_head *list) | |
1852 | { | |
1853 | int slabs_inuse = 0; | |
1854 | unsigned long flags; | |
1855 | struct page *page, *h; | |
1856 | ||
1857 | spin_lock_irqsave(&n->list_lock, flags); | |
1858 | list_for_each_entry_safe(page, h, list, lru) | |
1859 | if (!page->inuse) { | |
1860 | list_del(&page->lru); | |
1861 | discard_slab(s, page); | |
1862 | } else | |
1863 | slabs_inuse++; | |
1864 | spin_unlock_irqrestore(&n->list_lock, flags); | |
1865 | return slabs_inuse; | |
1866 | } | |
1867 | ||
1868 | /* | |
1869 | * Release all resources used by slab cache | |
1870 | */ | |
1871 | static int kmem_cache_close(struct kmem_cache *s) | |
1872 | { | |
1873 | int node; | |
1874 | ||
1875 | flush_all(s); | |
1876 | ||
1877 | /* Attempt to free all objects */ | |
1878 | for_each_online_node(node) { | |
1879 | struct kmem_cache_node *n = get_node(s, node); | |
1880 | ||
2086d26a | 1881 | n->nr_partial -= free_list(s, n, &n->partial); |
81819f0f CL |
1882 | if (atomic_long_read(&n->nr_slabs)) |
1883 | return 1; | |
1884 | } | |
1885 | free_kmem_cache_nodes(s); | |
1886 | return 0; | |
1887 | } | |
1888 | ||
1889 | /* | |
1890 | * Close a cache and release the kmem_cache structure | |
1891 | * (must be used for caches created using kmem_cache_create) | |
1892 | */ | |
1893 | void kmem_cache_destroy(struct kmem_cache *s) | |
1894 | { | |
1895 | down_write(&slub_lock); | |
1896 | s->refcount--; | |
1897 | if (!s->refcount) { | |
1898 | list_del(&s->list); | |
1899 | if (kmem_cache_close(s)) | |
1900 | WARN_ON(1); | |
1901 | sysfs_slab_remove(s); | |
1902 | kfree(s); | |
1903 | } | |
1904 | up_write(&slub_lock); | |
1905 | } | |
1906 | EXPORT_SYMBOL(kmem_cache_destroy); | |
1907 | ||
1908 | /******************************************************************** | |
1909 | * Kmalloc subsystem | |
1910 | *******************************************************************/ | |
1911 | ||
1912 | struct kmem_cache kmalloc_caches[KMALLOC_SHIFT_HIGH + 1] __cacheline_aligned; | |
1913 | EXPORT_SYMBOL(kmalloc_caches); | |
1914 | ||
1915 | #ifdef CONFIG_ZONE_DMA | |
1916 | static struct kmem_cache *kmalloc_caches_dma[KMALLOC_SHIFT_HIGH + 1]; | |
1917 | #endif | |
1918 | ||
1919 | static int __init setup_slub_min_order(char *str) | |
1920 | { | |
1921 | get_option (&str, &slub_min_order); | |
1922 | ||
1923 | return 1; | |
1924 | } | |
1925 | ||
1926 | __setup("slub_min_order=", setup_slub_min_order); | |
1927 | ||
1928 | static int __init setup_slub_max_order(char *str) | |
1929 | { | |
1930 | get_option (&str, &slub_max_order); | |
1931 | ||
1932 | return 1; | |
1933 | } | |
1934 | ||
1935 | __setup("slub_max_order=", setup_slub_max_order); | |
1936 | ||
1937 | static int __init setup_slub_min_objects(char *str) | |
1938 | { | |
1939 | get_option (&str, &slub_min_objects); | |
1940 | ||
1941 | return 1; | |
1942 | } | |
1943 | ||
1944 | __setup("slub_min_objects=", setup_slub_min_objects); | |
1945 | ||
1946 | static int __init setup_slub_nomerge(char *str) | |
1947 | { | |
1948 | slub_nomerge = 1; | |
1949 | return 1; | |
1950 | } | |
1951 | ||
1952 | __setup("slub_nomerge", setup_slub_nomerge); | |
1953 | ||
1954 | static int __init setup_slub_debug(char *str) | |
1955 | { | |
1956 | if (!str || *str != '=') | |
1957 | slub_debug = DEBUG_DEFAULT_FLAGS; | |
1958 | else { | |
1959 | str++; | |
1960 | if (*str == 0 || *str == ',') | |
1961 | slub_debug = DEBUG_DEFAULT_FLAGS; | |
1962 | else | |
1963 | for( ;*str && *str != ','; str++) | |
1964 | switch (*str) { | |
1965 | case 'f' : case 'F' : | |
1966 | slub_debug |= SLAB_DEBUG_FREE; | |
1967 | break; | |
1968 | case 'z' : case 'Z' : | |
1969 | slub_debug |= SLAB_RED_ZONE; | |
1970 | break; | |
1971 | case 'p' : case 'P' : | |
1972 | slub_debug |= SLAB_POISON; | |
1973 | break; | |
1974 | case 'u' : case 'U' : | |
1975 | slub_debug |= SLAB_STORE_USER; | |
1976 | break; | |
1977 | case 't' : case 'T' : | |
1978 | slub_debug |= SLAB_TRACE; | |
1979 | break; | |
1980 | default: | |
1981 | printk(KERN_ERR "slub_debug option '%c' " | |
1982 | "unknown. skipped\n",*str); | |
1983 | } | |
1984 | } | |
1985 | ||
1986 | if (*str == ',') | |
1987 | slub_debug_slabs = str + 1; | |
1988 | return 1; | |
1989 | } | |
1990 | ||
1991 | __setup("slub_debug", setup_slub_debug); | |
1992 | ||
1993 | static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s, | |
1994 | const char *name, int size, gfp_t gfp_flags) | |
1995 | { | |
1996 | unsigned int flags = 0; | |
1997 | ||
1998 | if (gfp_flags & SLUB_DMA) | |
1999 | flags = SLAB_CACHE_DMA; | |
2000 | ||
2001 | down_write(&slub_lock); | |
2002 | if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN, | |
2003 | flags, NULL, NULL)) | |
2004 | goto panic; | |
2005 | ||
2006 | list_add(&s->list, &slab_caches); | |
2007 | up_write(&slub_lock); | |
2008 | if (sysfs_slab_add(s)) | |
2009 | goto panic; | |
2010 | return s; | |
2011 | ||
2012 | panic: | |
2013 | panic("Creation of kmalloc slab %s size=%d failed.\n", name, size); | |
2014 | } | |
2015 | ||
2016 | static struct kmem_cache *get_slab(size_t size, gfp_t flags) | |
2017 | { | |
2018 | int index = kmalloc_index(size); | |
2019 | ||
614410d5 | 2020 | if (!index) |
81819f0f CL |
2021 | return NULL; |
2022 | ||
2023 | /* Allocation too large? */ | |
2024 | BUG_ON(index < 0); | |
2025 | ||
2026 | #ifdef CONFIG_ZONE_DMA | |
2027 | if ((flags & SLUB_DMA)) { | |
2028 | struct kmem_cache *s; | |
2029 | struct kmem_cache *x; | |
2030 | char *text; | |
2031 | size_t realsize; | |
2032 | ||
2033 | s = kmalloc_caches_dma[index]; | |
2034 | if (s) | |
2035 | return s; | |
2036 | ||
2037 | /* Dynamically create dma cache */ | |
2038 | x = kmalloc(kmem_size, flags & ~SLUB_DMA); | |
2039 | if (!x) | |
2040 | panic("Unable to allocate memory for dma cache\n"); | |
2041 | ||
2042 | if (index <= KMALLOC_SHIFT_HIGH) | |
2043 | realsize = 1 << index; | |
2044 | else { | |
2045 | if (index == 1) | |
2046 | realsize = 96; | |
2047 | else | |
2048 | realsize = 192; | |
2049 | } | |
2050 | ||
2051 | text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d", | |
2052 | (unsigned int)realsize); | |
2053 | s = create_kmalloc_cache(x, text, realsize, flags); | |
2054 | kmalloc_caches_dma[index] = s; | |
2055 | return s; | |
2056 | } | |
2057 | #endif | |
2058 | return &kmalloc_caches[index]; | |
2059 | } | |
2060 | ||
2061 | void *__kmalloc(size_t size, gfp_t flags) | |
2062 | { | |
2063 | struct kmem_cache *s = get_slab(size, flags); | |
2064 | ||
2065 | if (s) | |
77c5e2d0 | 2066 | return slab_alloc(s, flags, -1, __builtin_return_address(0)); |
81819f0f CL |
2067 | return NULL; |
2068 | } | |
2069 | EXPORT_SYMBOL(__kmalloc); | |
2070 | ||
2071 | #ifdef CONFIG_NUMA | |
2072 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
2073 | { | |
2074 | struct kmem_cache *s = get_slab(size, flags); | |
2075 | ||
2076 | if (s) | |
77c5e2d0 | 2077 | return slab_alloc(s, flags, node, __builtin_return_address(0)); |
81819f0f CL |
2078 | return NULL; |
2079 | } | |
2080 | EXPORT_SYMBOL(__kmalloc_node); | |
2081 | #endif | |
2082 | ||
2083 | size_t ksize(const void *object) | |
2084 | { | |
2085 | struct page *page = get_object_page(object); | |
2086 | struct kmem_cache *s; | |
2087 | ||
2088 | BUG_ON(!page); | |
2089 | s = page->slab; | |
2090 | BUG_ON(!s); | |
2091 | ||
2092 | /* | |
2093 | * Debugging requires use of the padding between object | |
2094 | * and whatever may come after it. | |
2095 | */ | |
2096 | if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) | |
2097 | return s->objsize; | |
2098 | ||
2099 | /* | |
2100 | * If we have the need to store the freelist pointer | |
2101 | * back there or track user information then we can | |
2102 | * only use the space before that information. | |
2103 | */ | |
2104 | if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) | |
2105 | return s->inuse; | |
2106 | ||
2107 | /* | |
2108 | * Else we can use all the padding etc for the allocation | |
2109 | */ | |
2110 | return s->size; | |
2111 | } | |
2112 | EXPORT_SYMBOL(ksize); | |
2113 | ||
2114 | void kfree(const void *x) | |
2115 | { | |
2116 | struct kmem_cache *s; | |
2117 | struct page *page; | |
2118 | ||
2119 | if (!x) | |
2120 | return; | |
2121 | ||
b49af68f | 2122 | page = virt_to_head_page(x); |
81819f0f CL |
2123 | s = page->slab; |
2124 | ||
77c5e2d0 | 2125 | slab_free(s, page, (void *)x, __builtin_return_address(0)); |
81819f0f CL |
2126 | } |
2127 | EXPORT_SYMBOL(kfree); | |
2128 | ||
2086d26a CL |
2129 | /* |
2130 | * kmem_cache_shrink removes empty slabs from the partial lists | |
2131 | * and then sorts the partially allocated slabs by the number | |
2132 | * of items in use. The slabs with the most items in use | |
2133 | * come first. New allocations will remove these from the | |
2134 | * partial list because they are full. The slabs with the | |
2135 | * least items are placed last. If it happens that the objects | |
2136 | * are freed then the page can be returned to the page allocator. | |
2137 | */ | |
2138 | int kmem_cache_shrink(struct kmem_cache *s) | |
2139 | { | |
2140 | int node; | |
2141 | int i; | |
2142 | struct kmem_cache_node *n; | |
2143 | struct page *page; | |
2144 | struct page *t; | |
2145 | struct list_head *slabs_by_inuse = | |
2146 | kmalloc(sizeof(struct list_head) * s->objects, GFP_KERNEL); | |
2147 | unsigned long flags; | |
2148 | ||
2149 | if (!slabs_by_inuse) | |
2150 | return -ENOMEM; | |
2151 | ||
2152 | flush_all(s); | |
2153 | for_each_online_node(node) { | |
2154 | n = get_node(s, node); | |
2155 | ||
2156 | if (!n->nr_partial) | |
2157 | continue; | |
2158 | ||
2159 | for (i = 0; i < s->objects; i++) | |
2160 | INIT_LIST_HEAD(slabs_by_inuse + i); | |
2161 | ||
2162 | spin_lock_irqsave(&n->list_lock, flags); | |
2163 | ||
2164 | /* | |
2165 | * Build lists indexed by the items in use in | |
2166 | * each slab or free slabs if empty. | |
2167 | * | |
2168 | * Note that concurrent frees may occur while | |
2169 | * we hold the list_lock. page->inuse here is | |
2170 | * the upper limit. | |
2171 | */ | |
2172 | list_for_each_entry_safe(page, t, &n->partial, lru) { | |
2173 | if (!page->inuse && slab_trylock(page)) { | |
2174 | /* | |
2175 | * Must hold slab lock here because slab_free | |
2176 | * may have freed the last object and be | |
2177 | * waiting to release the slab. | |
2178 | */ | |
2179 | list_del(&page->lru); | |
2180 | n->nr_partial--; | |
2181 | slab_unlock(page); | |
2182 | discard_slab(s, page); | |
2183 | } else { | |
2184 | if (n->nr_partial > MAX_PARTIAL) | |
2185 | list_move(&page->lru, | |
2186 | slabs_by_inuse + page->inuse); | |
2187 | } | |
2188 | } | |
2189 | ||
2190 | if (n->nr_partial <= MAX_PARTIAL) | |
2191 | goto out; | |
2192 | ||
2193 | /* | |
2194 | * Rebuild the partial list with the slabs filled up | |
2195 | * most first and the least used slabs at the end. | |
2196 | */ | |
2197 | for (i = s->objects - 1; i >= 0; i--) | |
2198 | list_splice(slabs_by_inuse + i, n->partial.prev); | |
2199 | ||
2200 | out: | |
2201 | spin_unlock_irqrestore(&n->list_lock, flags); | |
2202 | } | |
2203 | ||
2204 | kfree(slabs_by_inuse); | |
2205 | return 0; | |
2206 | } | |
2207 | EXPORT_SYMBOL(kmem_cache_shrink); | |
2208 | ||
81819f0f CL |
2209 | /** |
2210 | * krealloc - reallocate memory. The contents will remain unchanged. | |
2211 | * | |
2212 | * @p: object to reallocate memory for. | |
2213 | * @new_size: how many bytes of memory are required. | |
2214 | * @flags: the type of memory to allocate. | |
2215 | * | |
2216 | * The contents of the object pointed to are preserved up to the | |
2217 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
2218 | * behaves exactly like kmalloc(). If @size is 0 and @p is not a | |
2219 | * %NULL pointer, the object pointed to is freed. | |
2220 | */ | |
2221 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
2222 | { | |
2223 | struct kmem_cache *new_cache; | |
2224 | void *ret; | |
2225 | struct page *page; | |
2226 | ||
2227 | if (unlikely(!p)) | |
2228 | return kmalloc(new_size, flags); | |
2229 | ||
2230 | if (unlikely(!new_size)) { | |
2231 | kfree(p); | |
2232 | return NULL; | |
2233 | } | |
2234 | ||
b49af68f | 2235 | page = virt_to_head_page(p); |
81819f0f CL |
2236 | |
2237 | new_cache = get_slab(new_size, flags); | |
2238 | ||
2239 | /* | |
2240 | * If new size fits in the current cache, bail out. | |
2241 | */ | |
2242 | if (likely(page->slab == new_cache)) | |
2243 | return (void *)p; | |
2244 | ||
2245 | ret = kmalloc(new_size, flags); | |
2246 | if (ret) { | |
2247 | memcpy(ret, p, min(new_size, ksize(p))); | |
2248 | kfree(p); | |
2249 | } | |
2250 | return ret; | |
2251 | } | |
2252 | EXPORT_SYMBOL(krealloc); | |
2253 | ||
2254 | /******************************************************************** | |
2255 | * Basic setup of slabs | |
2256 | *******************************************************************/ | |
2257 | ||
2258 | void __init kmem_cache_init(void) | |
2259 | { | |
2260 | int i; | |
2261 | ||
2262 | #ifdef CONFIG_NUMA | |
2263 | /* | |
2264 | * Must first have the slab cache available for the allocations of the | |
2265 | * struct kmalloc_cache_node's. There is special bootstrap code in | |
2266 | * kmem_cache_open for slab_state == DOWN. | |
2267 | */ | |
2268 | create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node", | |
2269 | sizeof(struct kmem_cache_node), GFP_KERNEL); | |
2270 | #endif | |
2271 | ||
2272 | /* Able to allocate the per node structures */ | |
2273 | slab_state = PARTIAL; | |
2274 | ||
2275 | /* Caches that are not of the two-to-the-power-of size */ | |
2276 | create_kmalloc_cache(&kmalloc_caches[1], | |
2277 | "kmalloc-96", 96, GFP_KERNEL); | |
2278 | create_kmalloc_cache(&kmalloc_caches[2], | |
2279 | "kmalloc-192", 192, GFP_KERNEL); | |
2280 | ||
2281 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) | |
2282 | create_kmalloc_cache(&kmalloc_caches[i], | |
2283 | "kmalloc", 1 << i, GFP_KERNEL); | |
2284 | ||
2285 | slab_state = UP; | |
2286 | ||
2287 | /* Provide the correct kmalloc names now that the caches are up */ | |
2288 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) | |
2289 | kmalloc_caches[i]. name = | |
2290 | kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i); | |
2291 | ||
2292 | #ifdef CONFIG_SMP | |
2293 | register_cpu_notifier(&slab_notifier); | |
2294 | #endif | |
2295 | ||
2296 | if (nr_cpu_ids) /* Remove when nr_cpu_ids is fixed upstream ! */ | |
2297 | kmem_size = offsetof(struct kmem_cache, cpu_slab) | |
2298 | + nr_cpu_ids * sizeof(struct page *); | |
2299 | ||
2300 | printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," | |
2301 | " Processors=%d, Nodes=%d\n", | |
2302 | KMALLOC_SHIFT_HIGH, L1_CACHE_BYTES, | |
2303 | slub_min_order, slub_max_order, slub_min_objects, | |
2304 | nr_cpu_ids, nr_node_ids); | |
2305 | } | |
2306 | ||
2307 | /* | |
2308 | * Find a mergeable slab cache | |
2309 | */ | |
2310 | static int slab_unmergeable(struct kmem_cache *s) | |
2311 | { | |
2312 | if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) | |
2313 | return 1; | |
2314 | ||
2315 | if (s->ctor || s->dtor) | |
2316 | return 1; | |
2317 | ||
2318 | return 0; | |
2319 | } | |
2320 | ||
2321 | static struct kmem_cache *find_mergeable(size_t size, | |
2322 | size_t align, unsigned long flags, | |
2323 | void (*ctor)(void *, struct kmem_cache *, unsigned long), | |
2324 | void (*dtor)(void *, struct kmem_cache *, unsigned long)) | |
2325 | { | |
2326 | struct list_head *h; | |
2327 | ||
2328 | if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) | |
2329 | return NULL; | |
2330 | ||
2331 | if (ctor || dtor) | |
2332 | return NULL; | |
2333 | ||
2334 | size = ALIGN(size, sizeof(void *)); | |
2335 | align = calculate_alignment(flags, align, size); | |
2336 | size = ALIGN(size, align); | |
2337 | ||
2338 | list_for_each(h, &slab_caches) { | |
2339 | struct kmem_cache *s = | |
2340 | container_of(h, struct kmem_cache, list); | |
2341 | ||
2342 | if (slab_unmergeable(s)) | |
2343 | continue; | |
2344 | ||
2345 | if (size > s->size) | |
2346 | continue; | |
2347 | ||
2348 | if (((flags | slub_debug) & SLUB_MERGE_SAME) != | |
2349 | (s->flags & SLUB_MERGE_SAME)) | |
2350 | continue; | |
2351 | /* | |
2352 | * Check if alignment is compatible. | |
2353 | * Courtesy of Adrian Drzewiecki | |
2354 | */ | |
2355 | if ((s->size & ~(align -1)) != s->size) | |
2356 | continue; | |
2357 | ||
2358 | if (s->size - size >= sizeof(void *)) | |
2359 | continue; | |
2360 | ||
2361 | return s; | |
2362 | } | |
2363 | return NULL; | |
2364 | } | |
2365 | ||
2366 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |
2367 | size_t align, unsigned long flags, | |
2368 | void (*ctor)(void *, struct kmem_cache *, unsigned long), | |
2369 | void (*dtor)(void *, struct kmem_cache *, unsigned long)) | |
2370 | { | |
2371 | struct kmem_cache *s; | |
2372 | ||
2373 | down_write(&slub_lock); | |
2374 | s = find_mergeable(size, align, flags, dtor, ctor); | |
2375 | if (s) { | |
2376 | s->refcount++; | |
2377 | /* | |
2378 | * Adjust the object sizes so that we clear | |
2379 | * the complete object on kzalloc. | |
2380 | */ | |
2381 | s->objsize = max(s->objsize, (int)size); | |
2382 | s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *))); | |
2383 | if (sysfs_slab_alias(s, name)) | |
2384 | goto err; | |
2385 | } else { | |
2386 | s = kmalloc(kmem_size, GFP_KERNEL); | |
2387 | if (s && kmem_cache_open(s, GFP_KERNEL, name, | |
2388 | size, align, flags, ctor, dtor)) { | |
2389 | if (sysfs_slab_add(s)) { | |
2390 | kfree(s); | |
2391 | goto err; | |
2392 | } | |
2393 | list_add(&s->list, &slab_caches); | |
2394 | } else | |
2395 | kfree(s); | |
2396 | } | |
2397 | up_write(&slub_lock); | |
2398 | return s; | |
2399 | ||
2400 | err: | |
2401 | up_write(&slub_lock); | |
2402 | if (flags & SLAB_PANIC) | |
2403 | panic("Cannot create slabcache %s\n", name); | |
2404 | else | |
2405 | s = NULL; | |
2406 | return s; | |
2407 | } | |
2408 | EXPORT_SYMBOL(kmem_cache_create); | |
2409 | ||
2410 | void *kmem_cache_zalloc(struct kmem_cache *s, gfp_t flags) | |
2411 | { | |
2412 | void *x; | |
2413 | ||
77c5e2d0 | 2414 | x = slab_alloc(s, flags, -1, __builtin_return_address(0)); |
81819f0f CL |
2415 | if (x) |
2416 | memset(x, 0, s->objsize); | |
2417 | return x; | |
2418 | } | |
2419 | EXPORT_SYMBOL(kmem_cache_zalloc); | |
2420 | ||
2421 | #ifdef CONFIG_SMP | |
2422 | static void for_all_slabs(void (*func)(struct kmem_cache *, int), int cpu) | |
2423 | { | |
2424 | struct list_head *h; | |
2425 | ||
2426 | down_read(&slub_lock); | |
2427 | list_for_each(h, &slab_caches) { | |
2428 | struct kmem_cache *s = | |
2429 | container_of(h, struct kmem_cache, list); | |
2430 | ||
2431 | func(s, cpu); | |
2432 | } | |
2433 | up_read(&slub_lock); | |
2434 | } | |
2435 | ||
2436 | /* | |
2437 | * Use the cpu notifier to insure that the slab are flushed | |
2438 | * when necessary. | |
2439 | */ | |
2440 | static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb, | |
2441 | unsigned long action, void *hcpu) | |
2442 | { | |
2443 | long cpu = (long)hcpu; | |
2444 | ||
2445 | switch (action) { | |
2446 | case CPU_UP_CANCELED: | |
2447 | case CPU_DEAD: | |
2448 | for_all_slabs(__flush_cpu_slab, cpu); | |
2449 | break; | |
2450 | default: | |
2451 | break; | |
2452 | } | |
2453 | return NOTIFY_OK; | |
2454 | } | |
2455 | ||
2456 | static struct notifier_block __cpuinitdata slab_notifier = | |
2457 | { &slab_cpuup_callback, NULL, 0 }; | |
2458 | ||
2459 | #endif | |
2460 | ||
81819f0f CL |
2461 | #ifdef CONFIG_NUMA |
2462 | ||
2463 | /***************************************************************** | |
2464 | * Generic reaper used to support the page allocator | |
2465 | * (the cpu slabs are reaped by a per slab workqueue). | |
2466 | * | |
2467 | * Maybe move this to the page allocator? | |
2468 | ****************************************************************/ | |
2469 | ||
2470 | static DEFINE_PER_CPU(unsigned long, reap_node); | |
2471 | ||
2472 | static void init_reap_node(int cpu) | |
2473 | { | |
2474 | int node; | |
2475 | ||
2476 | node = next_node(cpu_to_node(cpu), node_online_map); | |
2477 | if (node == MAX_NUMNODES) | |
2478 | node = first_node(node_online_map); | |
2479 | ||
2480 | __get_cpu_var(reap_node) = node; | |
2481 | } | |
2482 | ||
2483 | static void next_reap_node(void) | |
2484 | { | |
2485 | int node = __get_cpu_var(reap_node); | |
2486 | ||
2487 | /* | |
2488 | * Also drain per cpu pages on remote zones | |
2489 | */ | |
2490 | if (node != numa_node_id()) | |
2491 | drain_node_pages(node); | |
2492 | ||
2493 | node = next_node(node, node_online_map); | |
2494 | if (unlikely(node >= MAX_NUMNODES)) | |
2495 | node = first_node(node_online_map); | |
2496 | __get_cpu_var(reap_node) = node; | |
2497 | } | |
2498 | #else | |
2499 | #define init_reap_node(cpu) do { } while (0) | |
2500 | #define next_reap_node(void) do { } while (0) | |
2501 | #endif | |
2502 | ||
2503 | #define REAPTIMEOUT_CPUC (2*HZ) | |
2504 | ||
2505 | #ifdef CONFIG_SMP | |
2506 | static DEFINE_PER_CPU(struct delayed_work, reap_work); | |
2507 | ||
2508 | static void cache_reap(struct work_struct *unused) | |
2509 | { | |
2510 | next_reap_node(); | |
2511 | refresh_cpu_vm_stats(smp_processor_id()); | |
2512 | schedule_delayed_work(&__get_cpu_var(reap_work), | |
2513 | REAPTIMEOUT_CPUC); | |
2514 | } | |
2515 | ||
2516 | static void __devinit start_cpu_timer(int cpu) | |
2517 | { | |
2518 | struct delayed_work *reap_work = &per_cpu(reap_work, cpu); | |
2519 | ||
2520 | /* | |
2521 | * When this gets called from do_initcalls via cpucache_init(), | |
2522 | * init_workqueues() has already run, so keventd will be setup | |
2523 | * at that time. | |
2524 | */ | |
2525 | if (keventd_up() && reap_work->work.func == NULL) { | |
2526 | init_reap_node(cpu); | |
2527 | INIT_DELAYED_WORK(reap_work, cache_reap); | |
2528 | schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu); | |
2529 | } | |
2530 | } | |
2531 | ||
2532 | static int __init cpucache_init(void) | |
2533 | { | |
2534 | int cpu; | |
2535 | ||
2536 | /* | |
2537 | * Register the timers that drain pcp pages and update vm statistics | |
2538 | */ | |
2539 | for_each_online_cpu(cpu) | |
2540 | start_cpu_timer(cpu); | |
2541 | return 0; | |
2542 | } | |
2543 | __initcall(cpucache_init); | |
2544 | #endif | |
2545 | ||
2546 | #ifdef SLUB_RESILIENCY_TEST | |
2547 | static unsigned long validate_slab_cache(struct kmem_cache *s); | |
2548 | ||
2549 | static void resiliency_test(void) | |
2550 | { | |
2551 | u8 *p; | |
2552 | ||
2553 | printk(KERN_ERR "SLUB resiliency testing\n"); | |
2554 | printk(KERN_ERR "-----------------------\n"); | |
2555 | printk(KERN_ERR "A. Corruption after allocation\n"); | |
2556 | ||
2557 | p = kzalloc(16, GFP_KERNEL); | |
2558 | p[16] = 0x12; | |
2559 | printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer" | |
2560 | " 0x12->0x%p\n\n", p + 16); | |
2561 | ||
2562 | validate_slab_cache(kmalloc_caches + 4); | |
2563 | ||
2564 | /* Hmmm... The next two are dangerous */ | |
2565 | p = kzalloc(32, GFP_KERNEL); | |
2566 | p[32 + sizeof(void *)] = 0x34; | |
2567 | printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab" | |
2568 | " 0x34 -> -0x%p\n", p); | |
2569 | printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n"); | |
2570 | ||
2571 | validate_slab_cache(kmalloc_caches + 5); | |
2572 | p = kzalloc(64, GFP_KERNEL); | |
2573 | p += 64 + (get_cycles() & 0xff) * sizeof(void *); | |
2574 | *p = 0x56; | |
2575 | printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n", | |
2576 | p); | |
2577 | printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n"); | |
2578 | validate_slab_cache(kmalloc_caches + 6); | |
2579 | ||
2580 | printk(KERN_ERR "\nB. Corruption after free\n"); | |
2581 | p = kzalloc(128, GFP_KERNEL); | |
2582 | kfree(p); | |
2583 | *p = 0x78; | |
2584 | printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p); | |
2585 | validate_slab_cache(kmalloc_caches + 7); | |
2586 | ||
2587 | p = kzalloc(256, GFP_KERNEL); | |
2588 | kfree(p); | |
2589 | p[50] = 0x9a; | |
2590 | printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", p); | |
2591 | validate_slab_cache(kmalloc_caches + 8); | |
2592 | ||
2593 | p = kzalloc(512, GFP_KERNEL); | |
2594 | kfree(p); | |
2595 | p[512] = 0xab; | |
2596 | printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p); | |
2597 | validate_slab_cache(kmalloc_caches + 9); | |
2598 | } | |
2599 | #else | |
2600 | static void resiliency_test(void) {}; | |
2601 | #endif | |
2602 | ||
2603 | /* | |
2604 | * These are not as efficient as kmalloc for the non debug case. | |
2605 | * We do not have the page struct available so we have to touch one | |
2606 | * cacheline in struct kmem_cache to check slab flags. | |
2607 | */ | |
2608 | void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller) | |
2609 | { | |
2610 | struct kmem_cache *s = get_slab(size, gfpflags); | |
81819f0f CL |
2611 | |
2612 | if (!s) | |
2613 | return NULL; | |
2614 | ||
77c5e2d0 | 2615 | return slab_alloc(s, gfpflags, -1, caller); |
81819f0f CL |
2616 | } |
2617 | ||
2618 | void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, | |
2619 | int node, void *caller) | |
2620 | { | |
2621 | struct kmem_cache *s = get_slab(size, gfpflags); | |
81819f0f CL |
2622 | |
2623 | if (!s) | |
2624 | return NULL; | |
2625 | ||
77c5e2d0 | 2626 | return slab_alloc(s, gfpflags, node, caller); |
81819f0f CL |
2627 | } |
2628 | ||
2629 | #ifdef CONFIG_SYSFS | |
2630 | ||
53e15af0 CL |
2631 | static int validate_slab(struct kmem_cache *s, struct page *page) |
2632 | { | |
2633 | void *p; | |
2634 | void *addr = page_address(page); | |
2635 | unsigned long map[BITS_TO_LONGS(s->objects)]; | |
2636 | ||
2637 | if (!check_slab(s, page) || | |
2638 | !on_freelist(s, page, NULL)) | |
2639 | return 0; | |
2640 | ||
2641 | /* Now we know that a valid freelist exists */ | |
2642 | bitmap_zero(map, s->objects); | |
2643 | ||
2644 | for(p = page->freelist; p; p = get_freepointer(s, p)) { | |
2645 | set_bit((p - addr) / s->size, map); | |
2646 | if (!check_object(s, page, p, 0)) | |
2647 | return 0; | |
2648 | } | |
2649 | ||
2650 | for(p = addr; p < addr + s->objects * s->size; p += s->size) | |
2651 | if (!test_bit((p - addr) / s->size, map)) | |
2652 | if (!check_object(s, page, p, 1)) | |
2653 | return 0; | |
2654 | return 1; | |
2655 | } | |
2656 | ||
2657 | static void validate_slab_slab(struct kmem_cache *s, struct page *page) | |
2658 | { | |
2659 | if (slab_trylock(page)) { | |
2660 | validate_slab(s, page); | |
2661 | slab_unlock(page); | |
2662 | } else | |
2663 | printk(KERN_INFO "SLUB %s: Skipped busy slab 0x%p\n", | |
2664 | s->name, page); | |
2665 | ||
2666 | if (s->flags & DEBUG_DEFAULT_FLAGS) { | |
2667 | if (!PageError(page)) | |
2668 | printk(KERN_ERR "SLUB %s: PageError not set " | |
2669 | "on slab 0x%p\n", s->name, page); | |
2670 | } else { | |
2671 | if (PageError(page)) | |
2672 | printk(KERN_ERR "SLUB %s: PageError set on " | |
2673 | "slab 0x%p\n", s->name, page); | |
2674 | } | |
2675 | } | |
2676 | ||
2677 | static int validate_slab_node(struct kmem_cache *s, struct kmem_cache_node *n) | |
2678 | { | |
2679 | unsigned long count = 0; | |
2680 | struct page *page; | |
2681 | unsigned long flags; | |
2682 | ||
2683 | spin_lock_irqsave(&n->list_lock, flags); | |
2684 | ||
2685 | list_for_each_entry(page, &n->partial, lru) { | |
2686 | validate_slab_slab(s, page); | |
2687 | count++; | |
2688 | } | |
2689 | if (count != n->nr_partial) | |
2690 | printk(KERN_ERR "SLUB %s: %ld partial slabs counted but " | |
2691 | "counter=%ld\n", s->name, count, n->nr_partial); | |
2692 | ||
2693 | if (!(s->flags & SLAB_STORE_USER)) | |
2694 | goto out; | |
2695 | ||
2696 | list_for_each_entry(page, &n->full, lru) { | |
2697 | validate_slab_slab(s, page); | |
2698 | count++; | |
2699 | } | |
2700 | if (count != atomic_long_read(&n->nr_slabs)) | |
2701 | printk(KERN_ERR "SLUB: %s %ld slabs counted but " | |
2702 | "counter=%ld\n", s->name, count, | |
2703 | atomic_long_read(&n->nr_slabs)); | |
2704 | ||
2705 | out: | |
2706 | spin_unlock_irqrestore(&n->list_lock, flags); | |
2707 | return count; | |
2708 | } | |
2709 | ||
2710 | static unsigned long validate_slab_cache(struct kmem_cache *s) | |
2711 | { | |
2712 | int node; | |
2713 | unsigned long count = 0; | |
2714 | ||
2715 | flush_all(s); | |
2716 | for_each_online_node(node) { | |
2717 | struct kmem_cache_node *n = get_node(s, node); | |
2718 | ||
2719 | count += validate_slab_node(s, n); | |
2720 | } | |
2721 | return count; | |
2722 | } | |
2723 | ||
88a420e4 CL |
2724 | /* |
2725 | * Generate lists of locations where slabcache objects are allocated | |
2726 | * and freed. | |
2727 | */ | |
2728 | ||
2729 | struct location { | |
2730 | unsigned long count; | |
2731 | void *addr; | |
2732 | }; | |
2733 | ||
2734 | struct loc_track { | |
2735 | unsigned long max; | |
2736 | unsigned long count; | |
2737 | struct location *loc; | |
2738 | }; | |
2739 | ||
2740 | static void free_loc_track(struct loc_track *t) | |
2741 | { | |
2742 | if (t->max) | |
2743 | free_pages((unsigned long)t->loc, | |
2744 | get_order(sizeof(struct location) * t->max)); | |
2745 | } | |
2746 | ||
2747 | static int alloc_loc_track(struct loc_track *t, unsigned long max) | |
2748 | { | |
2749 | struct location *l; | |
2750 | int order; | |
2751 | ||
2752 | if (!max) | |
2753 | max = PAGE_SIZE / sizeof(struct location); | |
2754 | ||
2755 | order = get_order(sizeof(struct location) * max); | |
2756 | ||
2757 | l = (void *)__get_free_pages(GFP_KERNEL, order); | |
2758 | ||
2759 | if (!l) | |
2760 | return 0; | |
2761 | ||
2762 | if (t->count) { | |
2763 | memcpy(l, t->loc, sizeof(struct location) * t->count); | |
2764 | free_loc_track(t); | |
2765 | } | |
2766 | t->max = max; | |
2767 | t->loc = l; | |
2768 | return 1; | |
2769 | } | |
2770 | ||
2771 | static int add_location(struct loc_track *t, struct kmem_cache *s, | |
2772 | void *addr) | |
2773 | { | |
2774 | long start, end, pos; | |
2775 | struct location *l; | |
2776 | void *caddr; | |
2777 | ||
2778 | start = -1; | |
2779 | end = t->count; | |
2780 | ||
2781 | for ( ; ; ) { | |
2782 | pos = start + (end - start + 1) / 2; | |
2783 | ||
2784 | /* | |
2785 | * There is nothing at "end". If we end up there | |
2786 | * we need to add something to before end. | |
2787 | */ | |
2788 | if (pos == end) | |
2789 | break; | |
2790 | ||
2791 | caddr = t->loc[pos].addr; | |
2792 | if (addr == caddr) { | |
2793 | t->loc[pos].count++; | |
2794 | return 1; | |
2795 | } | |
2796 | ||
2797 | if (addr < caddr) | |
2798 | end = pos; | |
2799 | else | |
2800 | start = pos; | |
2801 | } | |
2802 | ||
2803 | /* | |
2804 | * Not found. Insert new tracking element | |
2805 | */ | |
2806 | if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max)) | |
2807 | return 0; | |
2808 | ||
2809 | l = t->loc + pos; | |
2810 | if (pos < t->count) | |
2811 | memmove(l + 1, l, | |
2812 | (t->count - pos) * sizeof(struct location)); | |
2813 | t->count++; | |
2814 | l->count = 1; | |
2815 | l->addr = addr; | |
2816 | return 1; | |
2817 | } | |
2818 | ||
2819 | static void process_slab(struct loc_track *t, struct kmem_cache *s, | |
2820 | struct page *page, enum track_item alloc) | |
2821 | { | |
2822 | void *addr = page_address(page); | |
2823 | unsigned long map[BITS_TO_LONGS(s->objects)]; | |
2824 | void *p; | |
2825 | ||
2826 | bitmap_zero(map, s->objects); | |
2827 | for (p = page->freelist; p; p = get_freepointer(s, p)) | |
2828 | set_bit((p - addr) / s->size, map); | |
2829 | ||
2830 | for (p = addr; p < addr + s->objects * s->size; p += s->size) | |
2831 | if (!test_bit((p - addr) / s->size, map)) { | |
2832 | void *addr = get_track(s, p, alloc)->addr; | |
2833 | ||
2834 | add_location(t, s, addr); | |
2835 | } | |
2836 | } | |
2837 | ||
2838 | static int list_locations(struct kmem_cache *s, char *buf, | |
2839 | enum track_item alloc) | |
2840 | { | |
2841 | int n = 0; | |
2842 | unsigned long i; | |
2843 | struct loc_track t; | |
2844 | int node; | |
2845 | ||
2846 | t.count = 0; | |
2847 | t.max = 0; | |
2848 | ||
2849 | /* Push back cpu slabs */ | |
2850 | flush_all(s); | |
2851 | ||
2852 | for_each_online_node(node) { | |
2853 | struct kmem_cache_node *n = get_node(s, node); | |
2854 | unsigned long flags; | |
2855 | struct page *page; | |
2856 | ||
2857 | if (!atomic_read(&n->nr_slabs)) | |
2858 | continue; | |
2859 | ||
2860 | spin_lock_irqsave(&n->list_lock, flags); | |
2861 | list_for_each_entry(page, &n->partial, lru) | |
2862 | process_slab(&t, s, page, alloc); | |
2863 | list_for_each_entry(page, &n->full, lru) | |
2864 | process_slab(&t, s, page, alloc); | |
2865 | spin_unlock_irqrestore(&n->list_lock, flags); | |
2866 | } | |
2867 | ||
2868 | for (i = 0; i < t.count; i++) { | |
2869 | void *addr = t.loc[i].addr; | |
2870 | ||
2871 | if (n > PAGE_SIZE - 100) | |
2872 | break; | |
2873 | n += sprintf(buf + n, "%7ld ", t.loc[i].count); | |
2874 | if (addr) | |
2875 | n += sprint_symbol(buf + n, (unsigned long)t.loc[i].addr); | |
2876 | else | |
2877 | n += sprintf(buf + n, "<not-available>"); | |
2878 | n += sprintf(buf + n, "\n"); | |
2879 | } | |
2880 | ||
2881 | free_loc_track(&t); | |
2882 | if (!t.count) | |
2883 | n += sprintf(buf, "No data\n"); | |
2884 | return n; | |
2885 | } | |
2886 | ||
81819f0f CL |
2887 | static unsigned long count_partial(struct kmem_cache_node *n) |
2888 | { | |
2889 | unsigned long flags; | |
2890 | unsigned long x = 0; | |
2891 | struct page *page; | |
2892 | ||
2893 | spin_lock_irqsave(&n->list_lock, flags); | |
2894 | list_for_each_entry(page, &n->partial, lru) | |
2895 | x += page->inuse; | |
2896 | spin_unlock_irqrestore(&n->list_lock, flags); | |
2897 | return x; | |
2898 | } | |
2899 | ||
2900 | enum slab_stat_type { | |
2901 | SL_FULL, | |
2902 | SL_PARTIAL, | |
2903 | SL_CPU, | |
2904 | SL_OBJECTS | |
2905 | }; | |
2906 | ||
2907 | #define SO_FULL (1 << SL_FULL) | |
2908 | #define SO_PARTIAL (1 << SL_PARTIAL) | |
2909 | #define SO_CPU (1 << SL_CPU) | |
2910 | #define SO_OBJECTS (1 << SL_OBJECTS) | |
2911 | ||
2912 | static unsigned long slab_objects(struct kmem_cache *s, | |
2913 | char *buf, unsigned long flags) | |
2914 | { | |
2915 | unsigned long total = 0; | |
2916 | int cpu; | |
2917 | int node; | |
2918 | int x; | |
2919 | unsigned long *nodes; | |
2920 | unsigned long *per_cpu; | |
2921 | ||
2922 | nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); | |
2923 | per_cpu = nodes + nr_node_ids; | |
2924 | ||
2925 | for_each_possible_cpu(cpu) { | |
2926 | struct page *page = s->cpu_slab[cpu]; | |
2927 | int node; | |
2928 | ||
2929 | if (page) { | |
2930 | node = page_to_nid(page); | |
2931 | if (flags & SO_CPU) { | |
2932 | int x = 0; | |
2933 | ||
2934 | if (flags & SO_OBJECTS) | |
2935 | x = page->inuse; | |
2936 | else | |
2937 | x = 1; | |
2938 | total += x; | |
2939 | nodes[node] += x; | |
2940 | } | |
2941 | per_cpu[node]++; | |
2942 | } | |
2943 | } | |
2944 | ||
2945 | for_each_online_node(node) { | |
2946 | struct kmem_cache_node *n = get_node(s, node); | |
2947 | ||
2948 | if (flags & SO_PARTIAL) { | |
2949 | if (flags & SO_OBJECTS) | |
2950 | x = count_partial(n); | |
2951 | else | |
2952 | x = n->nr_partial; | |
2953 | total += x; | |
2954 | nodes[node] += x; | |
2955 | } | |
2956 | ||
2957 | if (flags & SO_FULL) { | |
2958 | int full_slabs = atomic_read(&n->nr_slabs) | |
2959 | - per_cpu[node] | |
2960 | - n->nr_partial; | |
2961 | ||
2962 | if (flags & SO_OBJECTS) | |
2963 | x = full_slabs * s->objects; | |
2964 | else | |
2965 | x = full_slabs; | |
2966 | total += x; | |
2967 | nodes[node] += x; | |
2968 | } | |
2969 | } | |
2970 | ||
2971 | x = sprintf(buf, "%lu", total); | |
2972 | #ifdef CONFIG_NUMA | |
2973 | for_each_online_node(node) | |
2974 | if (nodes[node]) | |
2975 | x += sprintf(buf + x, " N%d=%lu", | |
2976 | node, nodes[node]); | |
2977 | #endif | |
2978 | kfree(nodes); | |
2979 | return x + sprintf(buf + x, "\n"); | |
2980 | } | |
2981 | ||
2982 | static int any_slab_objects(struct kmem_cache *s) | |
2983 | { | |
2984 | int node; | |
2985 | int cpu; | |
2986 | ||
2987 | for_each_possible_cpu(cpu) | |
2988 | if (s->cpu_slab[cpu]) | |
2989 | return 1; | |
2990 | ||
2991 | for_each_node(node) { | |
2992 | struct kmem_cache_node *n = get_node(s, node); | |
2993 | ||
2994 | if (n->nr_partial || atomic_read(&n->nr_slabs)) | |
2995 | return 1; | |
2996 | } | |
2997 | return 0; | |
2998 | } | |
2999 | ||
3000 | #define to_slab_attr(n) container_of(n, struct slab_attribute, attr) | |
3001 | #define to_slab(n) container_of(n, struct kmem_cache, kobj); | |
3002 | ||
3003 | struct slab_attribute { | |
3004 | struct attribute attr; | |
3005 | ssize_t (*show)(struct kmem_cache *s, char *buf); | |
3006 | ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); | |
3007 | }; | |
3008 | ||
3009 | #define SLAB_ATTR_RO(_name) \ | |
3010 | static struct slab_attribute _name##_attr = __ATTR_RO(_name) | |
3011 | ||
3012 | #define SLAB_ATTR(_name) \ | |
3013 | static struct slab_attribute _name##_attr = \ | |
3014 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
3015 | ||
81819f0f CL |
3016 | static ssize_t slab_size_show(struct kmem_cache *s, char *buf) |
3017 | { | |
3018 | return sprintf(buf, "%d\n", s->size); | |
3019 | } | |
3020 | SLAB_ATTR_RO(slab_size); | |
3021 | ||
3022 | static ssize_t align_show(struct kmem_cache *s, char *buf) | |
3023 | { | |
3024 | return sprintf(buf, "%d\n", s->align); | |
3025 | } | |
3026 | SLAB_ATTR_RO(align); | |
3027 | ||
3028 | static ssize_t object_size_show(struct kmem_cache *s, char *buf) | |
3029 | { | |
3030 | return sprintf(buf, "%d\n", s->objsize); | |
3031 | } | |
3032 | SLAB_ATTR_RO(object_size); | |
3033 | ||
3034 | static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf) | |
3035 | { | |
3036 | return sprintf(buf, "%d\n", s->objects); | |
3037 | } | |
3038 | SLAB_ATTR_RO(objs_per_slab); | |
3039 | ||
3040 | static ssize_t order_show(struct kmem_cache *s, char *buf) | |
3041 | { | |
3042 | return sprintf(buf, "%d\n", s->order); | |
3043 | } | |
3044 | SLAB_ATTR_RO(order); | |
3045 | ||
3046 | static ssize_t ctor_show(struct kmem_cache *s, char *buf) | |
3047 | { | |
3048 | if (s->ctor) { | |
3049 | int n = sprint_symbol(buf, (unsigned long)s->ctor); | |
3050 | ||
3051 | return n + sprintf(buf + n, "\n"); | |
3052 | } | |
3053 | return 0; | |
3054 | } | |
3055 | SLAB_ATTR_RO(ctor); | |
3056 | ||
3057 | static ssize_t dtor_show(struct kmem_cache *s, char *buf) | |
3058 | { | |
3059 | if (s->dtor) { | |
3060 | int n = sprint_symbol(buf, (unsigned long)s->dtor); | |
3061 | ||
3062 | return n + sprintf(buf + n, "\n"); | |
3063 | } | |
3064 | return 0; | |
3065 | } | |
3066 | SLAB_ATTR_RO(dtor); | |
3067 | ||
3068 | static ssize_t aliases_show(struct kmem_cache *s, char *buf) | |
3069 | { | |
3070 | return sprintf(buf, "%d\n", s->refcount - 1); | |
3071 | } | |
3072 | SLAB_ATTR_RO(aliases); | |
3073 | ||
3074 | static ssize_t slabs_show(struct kmem_cache *s, char *buf) | |
3075 | { | |
3076 | return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU); | |
3077 | } | |
3078 | SLAB_ATTR_RO(slabs); | |
3079 | ||
3080 | static ssize_t partial_show(struct kmem_cache *s, char *buf) | |
3081 | { | |
3082 | return slab_objects(s, buf, SO_PARTIAL); | |
3083 | } | |
3084 | SLAB_ATTR_RO(partial); | |
3085 | ||
3086 | static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) | |
3087 | { | |
3088 | return slab_objects(s, buf, SO_CPU); | |
3089 | } | |
3090 | SLAB_ATTR_RO(cpu_slabs); | |
3091 | ||
3092 | static ssize_t objects_show(struct kmem_cache *s, char *buf) | |
3093 | { | |
3094 | return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS); | |
3095 | } | |
3096 | SLAB_ATTR_RO(objects); | |
3097 | ||
3098 | static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf) | |
3099 | { | |
3100 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE)); | |
3101 | } | |
3102 | ||
3103 | static ssize_t sanity_checks_store(struct kmem_cache *s, | |
3104 | const char *buf, size_t length) | |
3105 | { | |
3106 | s->flags &= ~SLAB_DEBUG_FREE; | |
3107 | if (buf[0] == '1') | |
3108 | s->flags |= SLAB_DEBUG_FREE; | |
3109 | return length; | |
3110 | } | |
3111 | SLAB_ATTR(sanity_checks); | |
3112 | ||
3113 | static ssize_t trace_show(struct kmem_cache *s, char *buf) | |
3114 | { | |
3115 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE)); | |
3116 | } | |
3117 | ||
3118 | static ssize_t trace_store(struct kmem_cache *s, const char *buf, | |
3119 | size_t length) | |
3120 | { | |
3121 | s->flags &= ~SLAB_TRACE; | |
3122 | if (buf[0] == '1') | |
3123 | s->flags |= SLAB_TRACE; | |
3124 | return length; | |
3125 | } | |
3126 | SLAB_ATTR(trace); | |
3127 | ||
3128 | static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) | |
3129 | { | |
3130 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); | |
3131 | } | |
3132 | ||
3133 | static ssize_t reclaim_account_store(struct kmem_cache *s, | |
3134 | const char *buf, size_t length) | |
3135 | { | |
3136 | s->flags &= ~SLAB_RECLAIM_ACCOUNT; | |
3137 | if (buf[0] == '1') | |
3138 | s->flags |= SLAB_RECLAIM_ACCOUNT; | |
3139 | return length; | |
3140 | } | |
3141 | SLAB_ATTR(reclaim_account); | |
3142 | ||
3143 | static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) | |
3144 | { | |
5af60839 | 3145 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN)); |
81819f0f CL |
3146 | } |
3147 | SLAB_ATTR_RO(hwcache_align); | |
3148 | ||
3149 | #ifdef CONFIG_ZONE_DMA | |
3150 | static ssize_t cache_dma_show(struct kmem_cache *s, char *buf) | |
3151 | { | |
3152 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA)); | |
3153 | } | |
3154 | SLAB_ATTR_RO(cache_dma); | |
3155 | #endif | |
3156 | ||
3157 | static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) | |
3158 | { | |
3159 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU)); | |
3160 | } | |
3161 | SLAB_ATTR_RO(destroy_by_rcu); | |
3162 | ||
3163 | static ssize_t red_zone_show(struct kmem_cache *s, char *buf) | |
3164 | { | |
3165 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE)); | |
3166 | } | |
3167 | ||
3168 | static ssize_t red_zone_store(struct kmem_cache *s, | |
3169 | const char *buf, size_t length) | |
3170 | { | |
3171 | if (any_slab_objects(s)) | |
3172 | return -EBUSY; | |
3173 | ||
3174 | s->flags &= ~SLAB_RED_ZONE; | |
3175 | if (buf[0] == '1') | |
3176 | s->flags |= SLAB_RED_ZONE; | |
3177 | calculate_sizes(s); | |
3178 | return length; | |
3179 | } | |
3180 | SLAB_ATTR(red_zone); | |
3181 | ||
3182 | static ssize_t poison_show(struct kmem_cache *s, char *buf) | |
3183 | { | |
3184 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON)); | |
3185 | } | |
3186 | ||
3187 | static ssize_t poison_store(struct kmem_cache *s, | |
3188 | const char *buf, size_t length) | |
3189 | { | |
3190 | if (any_slab_objects(s)) | |
3191 | return -EBUSY; | |
3192 | ||
3193 | s->flags &= ~SLAB_POISON; | |
3194 | if (buf[0] == '1') | |
3195 | s->flags |= SLAB_POISON; | |
3196 | calculate_sizes(s); | |
3197 | return length; | |
3198 | } | |
3199 | SLAB_ATTR(poison); | |
3200 | ||
3201 | static ssize_t store_user_show(struct kmem_cache *s, char *buf) | |
3202 | { | |
3203 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER)); | |
3204 | } | |
3205 | ||
3206 | static ssize_t store_user_store(struct kmem_cache *s, | |
3207 | const char *buf, size_t length) | |
3208 | { | |
3209 | if (any_slab_objects(s)) | |
3210 | return -EBUSY; | |
3211 | ||
3212 | s->flags &= ~SLAB_STORE_USER; | |
3213 | if (buf[0] == '1') | |
3214 | s->flags |= SLAB_STORE_USER; | |
3215 | calculate_sizes(s); | |
3216 | return length; | |
3217 | } | |
3218 | SLAB_ATTR(store_user); | |
3219 | ||
53e15af0 CL |
3220 | static ssize_t validate_show(struct kmem_cache *s, char *buf) |
3221 | { | |
3222 | return 0; | |
3223 | } | |
3224 | ||
3225 | static ssize_t validate_store(struct kmem_cache *s, | |
3226 | const char *buf, size_t length) | |
3227 | { | |
3228 | if (buf[0] == '1') | |
3229 | validate_slab_cache(s); | |
3230 | else | |
3231 | return -EINVAL; | |
3232 | return length; | |
3233 | } | |
3234 | SLAB_ATTR(validate); | |
3235 | ||
2086d26a CL |
3236 | static ssize_t shrink_show(struct kmem_cache *s, char *buf) |
3237 | { | |
3238 | return 0; | |
3239 | } | |
3240 | ||
3241 | static ssize_t shrink_store(struct kmem_cache *s, | |
3242 | const char *buf, size_t length) | |
3243 | { | |
3244 | if (buf[0] == '1') { | |
3245 | int rc = kmem_cache_shrink(s); | |
3246 | ||
3247 | if (rc) | |
3248 | return rc; | |
3249 | } else | |
3250 | return -EINVAL; | |
3251 | return length; | |
3252 | } | |
3253 | SLAB_ATTR(shrink); | |
3254 | ||
88a420e4 CL |
3255 | static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) |
3256 | { | |
3257 | if (!(s->flags & SLAB_STORE_USER)) | |
3258 | return -ENOSYS; | |
3259 | return list_locations(s, buf, TRACK_ALLOC); | |
3260 | } | |
3261 | SLAB_ATTR_RO(alloc_calls); | |
3262 | ||
3263 | static ssize_t free_calls_show(struct kmem_cache *s, char *buf) | |
3264 | { | |
3265 | if (!(s->flags & SLAB_STORE_USER)) | |
3266 | return -ENOSYS; | |
3267 | return list_locations(s, buf, TRACK_FREE); | |
3268 | } | |
3269 | SLAB_ATTR_RO(free_calls); | |
3270 | ||
81819f0f CL |
3271 | #ifdef CONFIG_NUMA |
3272 | static ssize_t defrag_ratio_show(struct kmem_cache *s, char *buf) | |
3273 | { | |
3274 | return sprintf(buf, "%d\n", s->defrag_ratio / 10); | |
3275 | } | |
3276 | ||
3277 | static ssize_t defrag_ratio_store(struct kmem_cache *s, | |
3278 | const char *buf, size_t length) | |
3279 | { | |
3280 | int n = simple_strtoul(buf, NULL, 10); | |
3281 | ||
3282 | if (n < 100) | |
3283 | s->defrag_ratio = n * 10; | |
3284 | return length; | |
3285 | } | |
3286 | SLAB_ATTR(defrag_ratio); | |
3287 | #endif | |
3288 | ||
3289 | static struct attribute * slab_attrs[] = { | |
3290 | &slab_size_attr.attr, | |
3291 | &object_size_attr.attr, | |
3292 | &objs_per_slab_attr.attr, | |
3293 | &order_attr.attr, | |
3294 | &objects_attr.attr, | |
3295 | &slabs_attr.attr, | |
3296 | &partial_attr.attr, | |
3297 | &cpu_slabs_attr.attr, | |
3298 | &ctor_attr.attr, | |
3299 | &dtor_attr.attr, | |
3300 | &aliases_attr.attr, | |
3301 | &align_attr.attr, | |
3302 | &sanity_checks_attr.attr, | |
3303 | &trace_attr.attr, | |
3304 | &hwcache_align_attr.attr, | |
3305 | &reclaim_account_attr.attr, | |
3306 | &destroy_by_rcu_attr.attr, | |
3307 | &red_zone_attr.attr, | |
3308 | &poison_attr.attr, | |
3309 | &store_user_attr.attr, | |
53e15af0 | 3310 | &validate_attr.attr, |
2086d26a | 3311 | &shrink_attr.attr, |
88a420e4 CL |
3312 | &alloc_calls_attr.attr, |
3313 | &free_calls_attr.attr, | |
81819f0f CL |
3314 | #ifdef CONFIG_ZONE_DMA |
3315 | &cache_dma_attr.attr, | |
3316 | #endif | |
3317 | #ifdef CONFIG_NUMA | |
3318 | &defrag_ratio_attr.attr, | |
3319 | #endif | |
3320 | NULL | |
3321 | }; | |
3322 | ||
3323 | static struct attribute_group slab_attr_group = { | |
3324 | .attrs = slab_attrs, | |
3325 | }; | |
3326 | ||
3327 | static ssize_t slab_attr_show(struct kobject *kobj, | |
3328 | struct attribute *attr, | |
3329 | char *buf) | |
3330 | { | |
3331 | struct slab_attribute *attribute; | |
3332 | struct kmem_cache *s; | |
3333 | int err; | |
3334 | ||
3335 | attribute = to_slab_attr(attr); | |
3336 | s = to_slab(kobj); | |
3337 | ||
3338 | if (!attribute->show) | |
3339 | return -EIO; | |
3340 | ||
3341 | err = attribute->show(s, buf); | |
3342 | ||
3343 | return err; | |
3344 | } | |
3345 | ||
3346 | static ssize_t slab_attr_store(struct kobject *kobj, | |
3347 | struct attribute *attr, | |
3348 | const char *buf, size_t len) | |
3349 | { | |
3350 | struct slab_attribute *attribute; | |
3351 | struct kmem_cache *s; | |
3352 | int err; | |
3353 | ||
3354 | attribute = to_slab_attr(attr); | |
3355 | s = to_slab(kobj); | |
3356 | ||
3357 | if (!attribute->store) | |
3358 | return -EIO; | |
3359 | ||
3360 | err = attribute->store(s, buf, len); | |
3361 | ||
3362 | return err; | |
3363 | } | |
3364 | ||
3365 | static struct sysfs_ops slab_sysfs_ops = { | |
3366 | .show = slab_attr_show, | |
3367 | .store = slab_attr_store, | |
3368 | }; | |
3369 | ||
3370 | static struct kobj_type slab_ktype = { | |
3371 | .sysfs_ops = &slab_sysfs_ops, | |
3372 | }; | |
3373 | ||
3374 | static int uevent_filter(struct kset *kset, struct kobject *kobj) | |
3375 | { | |
3376 | struct kobj_type *ktype = get_ktype(kobj); | |
3377 | ||
3378 | if (ktype == &slab_ktype) | |
3379 | return 1; | |
3380 | return 0; | |
3381 | } | |
3382 | ||
3383 | static struct kset_uevent_ops slab_uevent_ops = { | |
3384 | .filter = uevent_filter, | |
3385 | }; | |
3386 | ||
3387 | decl_subsys(slab, &slab_ktype, &slab_uevent_ops); | |
3388 | ||
3389 | #define ID_STR_LENGTH 64 | |
3390 | ||
3391 | /* Create a unique string id for a slab cache: | |
3392 | * format | |
3393 | * :[flags-]size:[memory address of kmemcache] | |
3394 | */ | |
3395 | static char *create_unique_id(struct kmem_cache *s) | |
3396 | { | |
3397 | char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); | |
3398 | char *p = name; | |
3399 | ||
3400 | BUG_ON(!name); | |
3401 | ||
3402 | *p++ = ':'; | |
3403 | /* | |
3404 | * First flags affecting slabcache operations. We will only | |
3405 | * get here for aliasable slabs so we do not need to support | |
3406 | * too many flags. The flags here must cover all flags that | |
3407 | * are matched during merging to guarantee that the id is | |
3408 | * unique. | |
3409 | */ | |
3410 | if (s->flags & SLAB_CACHE_DMA) | |
3411 | *p++ = 'd'; | |
3412 | if (s->flags & SLAB_RECLAIM_ACCOUNT) | |
3413 | *p++ = 'a'; | |
3414 | if (s->flags & SLAB_DEBUG_FREE) | |
3415 | *p++ = 'F'; | |
3416 | if (p != name + 1) | |
3417 | *p++ = '-'; | |
3418 | p += sprintf(p, "%07d", s->size); | |
3419 | BUG_ON(p > name + ID_STR_LENGTH - 1); | |
3420 | return name; | |
3421 | } | |
3422 | ||
3423 | static int sysfs_slab_add(struct kmem_cache *s) | |
3424 | { | |
3425 | int err; | |
3426 | const char *name; | |
3427 | int unmergeable; | |
3428 | ||
3429 | if (slab_state < SYSFS) | |
3430 | /* Defer until later */ | |
3431 | return 0; | |
3432 | ||
3433 | unmergeable = slab_unmergeable(s); | |
3434 | if (unmergeable) { | |
3435 | /* | |
3436 | * Slabcache can never be merged so we can use the name proper. | |
3437 | * This is typically the case for debug situations. In that | |
3438 | * case we can catch duplicate names easily. | |
3439 | */ | |
3440 | sysfs_remove_link(&slab_subsys.kset.kobj, s->name); | |
3441 | name = s->name; | |
3442 | } else { | |
3443 | /* | |
3444 | * Create a unique name for the slab as a target | |
3445 | * for the symlinks. | |
3446 | */ | |
3447 | name = create_unique_id(s); | |
3448 | } | |
3449 | ||
3450 | kobj_set_kset_s(s, slab_subsys); | |
3451 | kobject_set_name(&s->kobj, name); | |
3452 | kobject_init(&s->kobj); | |
3453 | err = kobject_add(&s->kobj); | |
3454 | if (err) | |
3455 | return err; | |
3456 | ||
3457 | err = sysfs_create_group(&s->kobj, &slab_attr_group); | |
3458 | if (err) | |
3459 | return err; | |
3460 | kobject_uevent(&s->kobj, KOBJ_ADD); | |
3461 | if (!unmergeable) { | |
3462 | /* Setup first alias */ | |
3463 | sysfs_slab_alias(s, s->name); | |
3464 | kfree(name); | |
3465 | } | |
3466 | return 0; | |
3467 | } | |
3468 | ||
3469 | static void sysfs_slab_remove(struct kmem_cache *s) | |
3470 | { | |
3471 | kobject_uevent(&s->kobj, KOBJ_REMOVE); | |
3472 | kobject_del(&s->kobj); | |
3473 | } | |
3474 | ||
3475 | /* | |
3476 | * Need to buffer aliases during bootup until sysfs becomes | |
3477 | * available lest we loose that information. | |
3478 | */ | |
3479 | struct saved_alias { | |
3480 | struct kmem_cache *s; | |
3481 | const char *name; | |
3482 | struct saved_alias *next; | |
3483 | }; | |
3484 | ||
3485 | struct saved_alias *alias_list; | |
3486 | ||
3487 | static int sysfs_slab_alias(struct kmem_cache *s, const char *name) | |
3488 | { | |
3489 | struct saved_alias *al; | |
3490 | ||
3491 | if (slab_state == SYSFS) { | |
3492 | /* | |
3493 | * If we have a leftover link then remove it. | |
3494 | */ | |
3495 | sysfs_remove_link(&slab_subsys.kset.kobj, name); | |
3496 | return sysfs_create_link(&slab_subsys.kset.kobj, | |
3497 | &s->kobj, name); | |
3498 | } | |
3499 | ||
3500 | al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); | |
3501 | if (!al) | |
3502 | return -ENOMEM; | |
3503 | ||
3504 | al->s = s; | |
3505 | al->name = name; | |
3506 | al->next = alias_list; | |
3507 | alias_list = al; | |
3508 | return 0; | |
3509 | } | |
3510 | ||
3511 | static int __init slab_sysfs_init(void) | |
3512 | { | |
3513 | int err; | |
3514 | ||
3515 | err = subsystem_register(&slab_subsys); | |
3516 | if (err) { | |
3517 | printk(KERN_ERR "Cannot register slab subsystem.\n"); | |
3518 | return -ENOSYS; | |
3519 | } | |
3520 | ||
3521 | finish_bootstrap(); | |
3522 | ||
3523 | while (alias_list) { | |
3524 | struct saved_alias *al = alias_list; | |
3525 | ||
3526 | alias_list = alias_list->next; | |
3527 | err = sysfs_slab_alias(al->s, al->name); | |
3528 | BUG_ON(err); | |
3529 | kfree(al); | |
3530 | } | |
3531 | ||
3532 | resiliency_test(); | |
3533 | return 0; | |
3534 | } | |
3535 | ||
3536 | __initcall(slab_sysfs_init); | |
3537 | #else | |
3538 | __initcall(finish_bootstrap); | |
3539 | #endif |