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Source at commit cdde9cf73945d547acd3e96f9508c79e84ad0bf1 created 12 years 9 months ago. By Maarten ter Huurne, MMC: JZ4740: Added support for CPU frequency changing | |
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1 | /* |
2 | * SLUB: A slab allocator that limits cache line use instead of queuing |
3 | * objects in per cpu and per node lists. |
4 | * |
5 | * The allocator synchronizes using per slab locks or atomic operatios |
6 | * and only uses a centralized lock to manage a pool of partial slabs. |
7 | * |
8 | * (C) 2007 SGI, Christoph Lameter |
9 | * (C) 2011 Linux Foundation, Christoph Lameter |
10 | */ |
11 | |
12 | #include <linux/mm.h> |
13 | #include <linux/swap.h> /* struct reclaim_state */ |
14 | #include <linux/module.h> |
15 | #include <linux/bit_spinlock.h> |
16 | #include <linux/interrupt.h> |
17 | #include <linux/bitops.h> |
18 | #include <linux/slab.h> |
19 | #include "slab.h" |
20 | #include <linux/proc_fs.h> |
21 | #include <linux/seq_file.h> |
22 | #include <linux/kmemcheck.h> |
23 | #include <linux/cpu.h> |
24 | #include <linux/cpuset.h> |
25 | #include <linux/mempolicy.h> |
26 | #include <linux/ctype.h> |
27 | #include <linux/debugobjects.h> |
28 | #include <linux/kallsyms.h> |
29 | #include <linux/memory.h> |
30 | #include <linux/math64.h> |
31 | #include <linux/fault-inject.h> |
32 | #include <linux/stacktrace.h> |
33 | #include <linux/prefetch.h> |
34 | |
35 | #include <trace/events/kmem.h> |
36 | |
37 | #include "internal.h" |
38 | |
39 | /* |
40 | * Lock order: |
41 | * 1. slab_mutex (Global Mutex) |
42 | * 2. node->list_lock |
43 | * 3. slab_lock(page) (Only on some arches and for debugging) |
44 | * |
45 | * slab_mutex |
46 | * |
47 | * The role of the slab_mutex is to protect the list of all the slabs |
48 | * and to synchronize major metadata changes to slab cache structures. |
49 | * |
50 | * The slab_lock is only used for debugging and on arches that do not |
51 | * have the ability to do a cmpxchg_double. It only protects the second |
52 | * double word in the page struct. Meaning |
53 | * A. page->freelist -> List of object free in a page |
54 | * B. page->counters -> Counters of objects |
55 | * C. page->frozen -> frozen state |
56 | * |
57 | * If a slab is frozen then it is exempt from list management. It is not |
58 | * on any list. The processor that froze the slab is the one who can |
59 | * perform list operations on the page. Other processors may put objects |
60 | * onto the freelist but the processor that froze the slab is the only |
61 | * one that can retrieve the objects from the page's freelist. |
62 | * |
63 | * The list_lock protects the partial and full list on each node and |
64 | * the partial slab counter. If taken then no new slabs may be added or |
65 | * removed from the lists nor make the number of partial slabs be modified. |
66 | * (Note that the total number of slabs is an atomic value that may be |
67 | * modified without taking the list lock). |
68 | * |
69 | * The list_lock is a centralized lock and thus we avoid taking it as |
70 | * much as possible. As long as SLUB does not have to handle partial |
71 | * slabs, operations can continue without any centralized lock. F.e. |
72 | * allocating a long series of objects that fill up slabs does not require |
73 | * the list lock. |
74 | * Interrupts are disabled during allocation and deallocation in order to |
75 | * make the slab allocator safe to use in the context of an irq. In addition |
76 | * interrupts are disabled to ensure that the processor does not change |
77 | * while handling per_cpu slabs, due to kernel preemption. |
78 | * |
79 | * SLUB assigns one slab for allocation to each processor. |
80 | * Allocations only occur from these slabs called cpu slabs. |
81 | * |
82 | * Slabs with free elements are kept on a partial list and during regular |
83 | * operations no list for full slabs is used. If an object in a full slab is |
84 | * freed then the slab will show up again on the partial lists. |
85 | * We track full slabs for debugging purposes though because otherwise we |
86 | * cannot scan all objects. |
87 | * |
88 | * Slabs are freed when they become empty. Teardown and setup is |
89 | * minimal so we rely on the page allocators per cpu caches for |
90 | * fast frees and allocs. |
91 | * |
92 | * Overloading of page flags that are otherwise used for LRU management. |
93 | * |
94 | * PageActive The slab is frozen and exempt from list processing. |
95 | * This means that the slab is dedicated to a purpose |
96 | * such as satisfying allocations for a specific |
97 | * processor. Objects may be freed in the slab while |
98 | * it is frozen but slab_free will then skip the usual |
99 | * list operations. It is up to the processor holding |
100 | * the slab to integrate the slab into the slab lists |
101 | * when the slab is no longer needed. |
102 | * |
103 | * One use of this flag is to mark slabs that are |
104 | * used for allocations. Then such a slab becomes a cpu |
105 | * slab. The cpu slab may be equipped with an additional |
106 | * freelist that allows lockless access to |
107 | * free objects in addition to the regular freelist |
108 | * that requires the slab lock. |
109 | * |
110 | * PageError Slab requires special handling due to debug |
111 | * options set. This moves slab handling out of |
112 | * the fast path and disables lockless freelists. |
113 | */ |
114 | |
115 | #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ |
116 | SLAB_TRACE | SLAB_DEBUG_FREE) |
117 | |
118 | static inline int kmem_cache_debug(struct kmem_cache *s) |
119 | { |
120 | #ifdef CONFIG_SLUB_DEBUG |
121 | return unlikely(s->flags & SLAB_DEBUG_FLAGS); |
122 | #else |
123 | return 0; |
124 | #endif |
125 | } |
126 | |
127 | /* |
128 | * Issues still to be resolved: |
129 | * |
130 | * - Support PAGE_ALLOC_DEBUG. Should be easy to do. |
131 | * |
132 | * - Variable sizing of the per node arrays |
133 | */ |
134 | |
135 | /* Enable to test recovery from slab corruption on boot */ |
136 | #undef SLUB_RESILIENCY_TEST |
137 | |
138 | /* Enable to log cmpxchg failures */ |
139 | #undef SLUB_DEBUG_CMPXCHG |
140 | |
141 | /* |
142 | * Mininum number of partial slabs. These will be left on the partial |
143 | * lists even if they are empty. kmem_cache_shrink may reclaim them. |
144 | */ |
145 | #define MIN_PARTIAL 5 |
146 | |
147 | /* |
148 | * Maximum number of desirable partial slabs. |
149 | * The existence of more partial slabs makes kmem_cache_shrink |
150 | * sort the partial list by the number of objects in the. |
151 | */ |
152 | #define MAX_PARTIAL 10 |
153 | |
154 | #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \ |
155 | SLAB_POISON | SLAB_STORE_USER) |
156 | |
157 | /* |
158 | * Debugging flags that require metadata to be stored in the slab. These get |
159 | * disabled when slub_debug=O is used and a cache's min order increases with |
160 | * metadata. |
161 | */ |
162 | #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) |
163 | |
164 | /* |
165 | * Set of flags that will prevent slab merging |
166 | */ |
167 | #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ |
168 | SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ |
169 | SLAB_FAILSLAB) |
170 | |
171 | #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ |
172 | SLAB_CACHE_DMA | SLAB_NOTRACK) |
173 | |
174 | #define OO_SHIFT 16 |
175 | #define OO_MASK ((1 << OO_SHIFT) - 1) |
176 | #define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */ |
177 | |
178 | /* Internal SLUB flags */ |
179 | #define __OBJECT_POISON 0x80000000UL /* Poison object */ |
180 | #define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */ |
181 | |
182 | static int kmem_size = sizeof(struct kmem_cache); |
183 | |
184 | #ifdef CONFIG_SMP |
185 | static struct notifier_block slab_notifier; |
186 | #endif |
187 | |
188 | /* |
189 | * Tracking user of a slab. |
190 | */ |
191 | #define TRACK_ADDRS_COUNT 16 |
192 | struct track { |
193 | unsigned long addr; /* Called from address */ |
194 | #ifdef CONFIG_STACKTRACE |
195 | unsigned long addrs[TRACK_ADDRS_COUNT]; /* Called from address */ |
196 | #endif |
197 | int cpu; /* Was running on cpu */ |
198 | int pid; /* Pid context */ |
199 | unsigned long when; /* When did the operation occur */ |
200 | }; |
201 | |
202 | enum track_item { TRACK_ALLOC, TRACK_FREE }; |
203 | |
204 | #ifdef CONFIG_SYSFS |
205 | static int sysfs_slab_add(struct kmem_cache *); |
206 | static int sysfs_slab_alias(struct kmem_cache *, const char *); |
207 | static void sysfs_slab_remove(struct kmem_cache *); |
208 | |
209 | #else |
210 | static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; } |
211 | static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) |
212 | { return 0; } |
213 | static inline void sysfs_slab_remove(struct kmem_cache *s) |
214 | { |
215 | kfree(s->name); |
216 | kfree(s); |
217 | } |
218 | |
219 | #endif |
220 | |
221 | static inline void stat(const struct kmem_cache *s, enum stat_item si) |
222 | { |
223 | #ifdef CONFIG_SLUB_STATS |
224 | __this_cpu_inc(s->cpu_slab->stat[si]); |
225 | #endif |
226 | } |
227 | |
228 | /******************************************************************** |
229 | * Core slab cache functions |
230 | *******************************************************************/ |
231 | |
232 | static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) |
233 | { |
234 | return s->node[node]; |
235 | } |
236 | |
237 | /* Verify that a pointer has an address that is valid within a slab page */ |
238 | static inline int check_valid_pointer(struct kmem_cache *s, |
239 | struct page *page, const void *object) |
240 | { |
241 | void *base; |
242 | |
243 | if (!object) |
244 | return 1; |
245 | |
246 | base = page_address(page); |
247 | if (object < base || object >= base + page->objects * s->size || |
248 | (object - base) % s->size) { |
249 | return 0; |
250 | } |
251 | |
252 | return 1; |
253 | } |
254 | |
255 | static inline void *get_freepointer(struct kmem_cache *s, void *object) |
256 | { |
257 | return *(void **)(object + s->offset); |
258 | } |
259 | |
260 | static void prefetch_freepointer(const struct kmem_cache *s, void *object) |
261 | { |
262 | prefetch(object + s->offset); |
263 | } |
264 | |
265 | static inline void *get_freepointer_safe(struct kmem_cache *s, void *object) |
266 | { |
267 | void *p; |
268 | |
269 | #ifdef CONFIG_DEBUG_PAGEALLOC |
270 | probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p)); |
271 | #else |
272 | p = get_freepointer(s, object); |
273 | #endif |
274 | return p; |
275 | } |
276 | |
277 | static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) |
278 | { |
279 | *(void **)(object + s->offset) = fp; |
280 | } |
281 | |
282 | /* Loop over all objects in a slab */ |
283 | #define for_each_object(__p, __s, __addr, __objects) \ |
284 | for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\ |
285 | __p += (__s)->size) |
286 | |
287 | /* Determine object index from a given position */ |
288 | static inline int slab_index(void *p, struct kmem_cache *s, void *addr) |
289 | { |
290 | return (p - addr) / s->size; |
291 | } |
292 | |
293 | static inline size_t slab_ksize(const struct kmem_cache *s) |
294 | { |
295 | #ifdef CONFIG_SLUB_DEBUG |
296 | /* |
297 | * Debugging requires use of the padding between object |
298 | * and whatever may come after it. |
299 | */ |
300 | if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) |
301 | return s->object_size; |
302 | |
303 | #endif |
304 | /* |
305 | * If we have the need to store the freelist pointer |
306 | * back there or track user information then we can |
307 | * only use the space before that information. |
308 | */ |
309 | if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) |
310 | return s->inuse; |
311 | /* |
312 | * Else we can use all the padding etc for the allocation |
313 | */ |
314 | return s->size; |
315 | } |
316 | |
317 | static inline int order_objects(int order, unsigned long size, int reserved) |
318 | { |
319 | return ((PAGE_SIZE << order) - reserved) / size; |
320 | } |
321 | |
322 | static inline struct kmem_cache_order_objects oo_make(int order, |
323 | unsigned long size, int reserved) |
324 | { |
325 | struct kmem_cache_order_objects x = { |
326 | (order << OO_SHIFT) + order_objects(order, size, reserved) |
327 | }; |
328 | |
329 | return x; |
330 | } |
331 | |
332 | static inline int oo_order(struct kmem_cache_order_objects x) |
333 | { |
334 | return x.x >> OO_SHIFT; |
335 | } |
336 | |
337 | static inline int oo_objects(struct kmem_cache_order_objects x) |
338 | { |
339 | return x.x & OO_MASK; |
340 | } |
341 | |
342 | /* |
343 | * Per slab locking using the pagelock |
344 | */ |
345 | static __always_inline void slab_lock(struct page *page) |
346 | { |
347 | bit_spin_lock(PG_locked, &page->flags); |
348 | } |
349 | |
350 | static __always_inline void slab_unlock(struct page *page) |
351 | { |
352 | __bit_spin_unlock(PG_locked, &page->flags); |
353 | } |
354 | |
355 | /* Interrupts must be disabled (for the fallback code to work right) */ |
356 | static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page, |
357 | void *freelist_old, unsigned long counters_old, |
358 | void *freelist_new, unsigned long counters_new, |
359 | const char *n) |
360 | { |
361 | VM_BUG_ON(!irqs_disabled()); |
362 | #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ |
363 | defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) |
364 | if (s->flags & __CMPXCHG_DOUBLE) { |
365 | if (cmpxchg_double(&page->freelist, &page->counters, |
366 | freelist_old, counters_old, |
367 | freelist_new, counters_new)) |
368 | return 1; |
369 | } else |
370 | #endif |
371 | { |
372 | slab_lock(page); |
373 | if (page->freelist == freelist_old && page->counters == counters_old) { |
374 | page->freelist = freelist_new; |
375 | page->counters = counters_new; |
376 | slab_unlock(page); |
377 | return 1; |
378 | } |
379 | slab_unlock(page); |
380 | } |
381 | |
382 | cpu_relax(); |
383 | stat(s, CMPXCHG_DOUBLE_FAIL); |
384 | |
385 | #ifdef SLUB_DEBUG_CMPXCHG |
386 | printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name); |
387 | #endif |
388 | |
389 | return 0; |
390 | } |
391 | |
392 | static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page, |
393 | void *freelist_old, unsigned long counters_old, |
394 | void *freelist_new, unsigned long counters_new, |
395 | const char *n) |
396 | { |
397 | #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ |
398 | defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) |
399 | if (s->flags & __CMPXCHG_DOUBLE) { |
400 | if (cmpxchg_double(&page->freelist, &page->counters, |
401 | freelist_old, counters_old, |
402 | freelist_new, counters_new)) |
403 | return 1; |
404 | } else |
405 | #endif |
406 | { |
407 | unsigned long flags; |
408 | |
409 | local_irq_save(flags); |
410 | slab_lock(page); |
411 | if (page->freelist == freelist_old && page->counters == counters_old) { |
412 | page->freelist = freelist_new; |
413 | page->counters = counters_new; |
414 | slab_unlock(page); |
415 | local_irq_restore(flags); |
416 | return 1; |
417 | } |
418 | slab_unlock(page); |
419 | local_irq_restore(flags); |
420 | } |
421 | |
422 | cpu_relax(); |
423 | stat(s, CMPXCHG_DOUBLE_FAIL); |
424 | |
425 | #ifdef SLUB_DEBUG_CMPXCHG |
426 | printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name); |
427 | #endif |
428 | |
429 | return 0; |
430 | } |
431 | |
432 | #ifdef CONFIG_SLUB_DEBUG |
433 | /* |
434 | * Determine a map of object in use on a page. |
435 | * |
436 | * Node listlock must be held to guarantee that the page does |
437 | * not vanish from under us. |
438 | */ |
439 | static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map) |
440 | { |
441 | void *p; |
442 | void *addr = page_address(page); |
443 | |
444 | for (p = page->freelist; p; p = get_freepointer(s, p)) |
445 | set_bit(slab_index(p, s, addr), map); |
446 | } |
447 | |
448 | /* |
449 | * Debug settings: |
450 | */ |
451 | #ifdef CONFIG_SLUB_DEBUG_ON |
452 | static int slub_debug = DEBUG_DEFAULT_FLAGS; |
453 | #else |
454 | static int slub_debug; |
455 | #endif |
456 | |
457 | static char *slub_debug_slabs; |
458 | static int disable_higher_order_debug; |
459 | |
460 | /* |
461 | * Object debugging |
462 | */ |
463 | static void print_section(char *text, u8 *addr, unsigned int length) |
464 | { |
465 | print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr, |
466 | length, 1); |
467 | } |
468 | |
469 | static struct track *get_track(struct kmem_cache *s, void *object, |
470 | enum track_item alloc) |
471 | { |
472 | struct track *p; |
473 | |
474 | if (s->offset) |
475 | p = object + s->offset + sizeof(void *); |
476 | else |
477 | p = object + s->inuse; |
478 | |
479 | return p + alloc; |
480 | } |
481 | |
482 | static void set_track(struct kmem_cache *s, void *object, |
483 | enum track_item alloc, unsigned long addr) |
484 | { |
485 | struct track *p = get_track(s, object, alloc); |
486 | |
487 | if (addr) { |
488 | #ifdef CONFIG_STACKTRACE |
489 | struct stack_trace trace; |
490 | int i; |
491 | |
492 | trace.nr_entries = 0; |
493 | trace.max_entries = TRACK_ADDRS_COUNT; |
494 | trace.entries = p->addrs; |
495 | trace.skip = 3; |
496 | save_stack_trace(&trace); |
497 | |
498 | /* See rant in lockdep.c */ |
499 | if (trace.nr_entries != 0 && |
500 | trace.entries[trace.nr_entries - 1] == ULONG_MAX) |
501 | trace.nr_entries--; |
502 | |
503 | for (i = trace.nr_entries; i < TRACK_ADDRS_COUNT; i++) |
504 | p->addrs[i] = 0; |
505 | #endif |
506 | p->addr = addr; |
507 | p->cpu = smp_processor_id(); |
508 | p->pid = current->pid; |
509 | p->when = jiffies; |
510 | } else |
511 | memset(p, 0, sizeof(struct track)); |
512 | } |
513 | |
514 | static void init_tracking(struct kmem_cache *s, void *object) |
515 | { |
516 | if (!(s->flags & SLAB_STORE_USER)) |
517 | return; |
518 | |
519 | set_track(s, object, TRACK_FREE, 0UL); |
520 | set_track(s, object, TRACK_ALLOC, 0UL); |
521 | } |
522 | |
523 | static void print_track(const char *s, struct track *t) |
524 | { |
525 | if (!t->addr) |
526 | return; |
527 | |
528 | printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n", |
529 | s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid); |
530 | #ifdef CONFIG_STACKTRACE |
531 | { |
532 | int i; |
533 | for (i = 0; i < TRACK_ADDRS_COUNT; i++) |
534 | if (t->addrs[i]) |
535 | printk(KERN_ERR "\t%pS\n", (void *)t->addrs[i]); |
536 | else |
537 | break; |
538 | } |
539 | #endif |
540 | } |
541 | |
542 | static void print_tracking(struct kmem_cache *s, void *object) |
543 | { |
544 | if (!(s->flags & SLAB_STORE_USER)) |
545 | return; |
546 | |
547 | print_track("Allocated", get_track(s, object, TRACK_ALLOC)); |
548 | print_track("Freed", get_track(s, object, TRACK_FREE)); |
549 | } |
550 | |
551 | static void print_page_info(struct page *page) |
552 | { |
553 | printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n", |
554 | page, page->objects, page->inuse, page->freelist, page->flags); |
555 | |
556 | } |
557 | |
558 | static void slab_bug(struct kmem_cache *s, char *fmt, ...) |
559 | { |
560 | va_list args; |
561 | char buf[100]; |
562 | |
563 | va_start(args, fmt); |
564 | vsnprintf(buf, sizeof(buf), fmt, args); |
565 | va_end(args); |
566 | printk(KERN_ERR "========================================" |
567 | "=====================================\n"); |
568 | printk(KERN_ERR "BUG %s (%s): %s\n", s->name, print_tainted(), buf); |
569 | printk(KERN_ERR "----------------------------------------" |
570 | "-------------------------------------\n\n"); |
571 | } |
572 | |
573 | static void slab_fix(struct kmem_cache *s, char *fmt, ...) |
574 | { |
575 | va_list args; |
576 | char buf[100]; |
577 | |
578 | va_start(args, fmt); |
579 | vsnprintf(buf, sizeof(buf), fmt, args); |
580 | va_end(args); |
581 | printk(KERN_ERR "FIX %s: %s\n", s->name, buf); |
582 | } |
583 | |
584 | static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p) |
585 | { |
586 | unsigned int off; /* Offset of last byte */ |
587 | u8 *addr = page_address(page); |
588 | |
589 | print_tracking(s, p); |
590 | |
591 | print_page_info(page); |
592 | |
593 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n", |
594 | p, p - addr, get_freepointer(s, p)); |
595 | |
596 | if (p > addr + 16) |
597 | print_section("Bytes b4 ", p - 16, 16); |
598 | |
599 | print_section("Object ", p, min_t(unsigned long, s->object_size, |
600 | PAGE_SIZE)); |
601 | if (s->flags & SLAB_RED_ZONE) |
602 | print_section("Redzone ", p + s->object_size, |
603 | s->inuse - s->object_size); |
604 | |
605 | if (s->offset) |
606 | off = s->offset + sizeof(void *); |
607 | else |
608 | off = s->inuse; |
609 | |
610 | if (s->flags & SLAB_STORE_USER) |
611 | off += 2 * sizeof(struct track); |
612 | |
613 | if (off != s->size) |
614 | /* Beginning of the filler is the free pointer */ |
615 | print_section("Padding ", p + off, s->size - off); |
616 | |
617 | dump_stack(); |
618 | } |
619 | |
620 | static void object_err(struct kmem_cache *s, struct page *page, |
621 | u8 *object, char *reason) |
622 | { |
623 | slab_bug(s, "%s", reason); |
624 | print_trailer(s, page, object); |
625 | } |
626 | |
627 | static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...) |
628 | { |
629 | va_list args; |
630 | char buf[100]; |
631 | |
632 | va_start(args, fmt); |
633 | vsnprintf(buf, sizeof(buf), fmt, args); |
634 | va_end(args); |
635 | slab_bug(s, "%s", buf); |
636 | print_page_info(page); |
637 | dump_stack(); |
638 | } |
639 | |
640 | static void init_object(struct kmem_cache *s, void *object, u8 val) |
641 | { |
642 | u8 *p = object; |
643 | |
644 | if (s->flags & __OBJECT_POISON) { |
645 | memset(p, POISON_FREE, s->object_size - 1); |
646 | p[s->object_size - 1] = POISON_END; |
647 | } |
648 | |
649 | if (s->flags & SLAB_RED_ZONE) |
650 | memset(p + s->object_size, val, s->inuse - s->object_size); |
651 | } |
652 | |
653 | static void restore_bytes(struct kmem_cache *s, char *message, u8 data, |
654 | void *from, void *to) |
655 | { |
656 | slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data); |
657 | memset(from, data, to - from); |
658 | } |
659 | |
660 | static int check_bytes_and_report(struct kmem_cache *s, struct page *page, |
661 | u8 *object, char *what, |
662 | u8 *start, unsigned int value, unsigned int bytes) |
663 | { |
664 | u8 *fault; |
665 | u8 *end; |
666 | |
667 | fault = memchr_inv(start, value, bytes); |
668 | if (!fault) |
669 | return 1; |
670 | |
671 | end = start + bytes; |
672 | while (end > fault && end[-1] == value) |
673 | end--; |
674 | |
675 | slab_bug(s, "%s overwritten", what); |
676 | printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n", |
677 | fault, end - 1, fault[0], value); |
678 | print_trailer(s, page, object); |
679 | |
680 | restore_bytes(s, what, value, fault, end); |
681 | return 0; |
682 | } |
683 | |
684 | /* |
685 | * Object layout: |
686 | * |
687 | * object address |
688 | * Bytes of the object to be managed. |
689 | * If the freepointer may overlay the object then the free |
690 | * pointer is the first word of the object. |
691 | * |
692 | * Poisoning uses 0x6b (POISON_FREE) and the last byte is |
693 | * 0xa5 (POISON_END) |
694 | * |
695 | * object + s->object_size |
696 | * Padding to reach word boundary. This is also used for Redzoning. |
697 | * Padding is extended by another word if Redzoning is enabled and |
698 | * object_size == inuse. |
699 | * |
700 | * We fill with 0xbb (RED_INACTIVE) for inactive objects and with |
701 | * 0xcc (RED_ACTIVE) for objects in use. |
702 | * |
703 | * object + s->inuse |
704 | * Meta data starts here. |
705 | * |
706 | * A. Free pointer (if we cannot overwrite object on free) |
707 | * B. Tracking data for SLAB_STORE_USER |
708 | * C. Padding to reach required alignment boundary or at mininum |
709 | * one word if debugging is on to be able to detect writes |
710 | * before the word boundary. |
711 | * |
712 | * Padding is done using 0x5a (POISON_INUSE) |
713 | * |
714 | * object + s->size |
715 | * Nothing is used beyond s->size. |
716 | * |
717 | * If slabcaches are merged then the object_size and inuse boundaries are mostly |
718 | * ignored. And therefore no slab options that rely on these boundaries |
719 | * may be used with merged slabcaches. |
720 | */ |
721 | |
722 | static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p) |
723 | { |
724 | unsigned long off = s->inuse; /* The end of info */ |
725 | |
726 | if (s->offset) |
727 | /* Freepointer is placed after the object. */ |
728 | off += sizeof(void *); |
729 | |
730 | if (s->flags & SLAB_STORE_USER) |
731 | /* We also have user information there */ |
732 | off += 2 * sizeof(struct track); |
733 | |
734 | if (s->size == off) |
735 | return 1; |
736 | |
737 | return check_bytes_and_report(s, page, p, "Object padding", |
738 | p + off, POISON_INUSE, s->size - off); |
739 | } |
740 | |
741 | /* Check the pad bytes at the end of a slab page */ |
742 | static int slab_pad_check(struct kmem_cache *s, struct page *page) |
743 | { |
744 | u8 *start; |
745 | u8 *fault; |
746 | u8 *end; |
747 | int length; |
748 | int remainder; |
749 | |
750 | if (!(s->flags & SLAB_POISON)) |
751 | return 1; |
752 | |
753 | start = page_address(page); |
754 | length = (PAGE_SIZE << compound_order(page)) - s->reserved; |
755 | end = start + length; |
756 | remainder = length % s->size; |
757 | if (!remainder) |
758 | return 1; |
759 | |
760 | fault = memchr_inv(end - remainder, POISON_INUSE, remainder); |
761 | if (!fault) |
762 | return 1; |
763 | while (end > fault && end[-1] == POISON_INUSE) |
764 | end--; |
765 | |
766 | slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1); |
767 | print_section("Padding ", end - remainder, remainder); |
768 | |
769 | restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end); |
770 | return 0; |
771 | } |
772 | |
773 | static int check_object(struct kmem_cache *s, struct page *page, |
774 | void *object, u8 val) |
775 | { |
776 | u8 *p = object; |
777 | u8 *endobject = object + s->object_size; |
778 | |
779 | if (s->flags & SLAB_RED_ZONE) { |
780 | if (!check_bytes_and_report(s, page, object, "Redzone", |
781 | endobject, val, s->inuse - s->object_size)) |
782 | return 0; |
783 | } else { |
784 | if ((s->flags & SLAB_POISON) && s->object_size < s->inuse) { |
785 | check_bytes_and_report(s, page, p, "Alignment padding", |
786 | endobject, POISON_INUSE, s->inuse - s->object_size); |
787 | } |
788 | } |
789 | |
790 | if (s->flags & SLAB_POISON) { |
791 | if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) && |
792 | (!check_bytes_and_report(s, page, p, "Poison", p, |
793 | POISON_FREE, s->object_size - 1) || |
794 | !check_bytes_and_report(s, page, p, "Poison", |
795 | p + s->object_size - 1, POISON_END, 1))) |
796 | return 0; |
797 | /* |
798 | * check_pad_bytes cleans up on its own. |
799 | */ |
800 | check_pad_bytes(s, page, p); |
801 | } |
802 | |
803 | if (!s->offset && val == SLUB_RED_ACTIVE) |
804 | /* |
805 | * Object and freepointer overlap. Cannot check |
806 | * freepointer while object is allocated. |
807 | */ |
808 | return 1; |
809 | |
810 | /* Check free pointer validity */ |
811 | if (!check_valid_pointer(s, page, get_freepointer(s, p))) { |
812 | object_err(s, page, p, "Freepointer corrupt"); |
813 | /* |
814 | * No choice but to zap it and thus lose the remainder |
815 | * of the free objects in this slab. May cause |
816 | * another error because the object count is now wrong. |
817 | */ |
818 | set_freepointer(s, p, NULL); |
819 | return 0; |
820 | } |
821 | return 1; |
822 | } |
823 | |
824 | static int check_slab(struct kmem_cache *s, struct page *page) |
825 | { |
826 | int maxobj; |
827 | |
828 | VM_BUG_ON(!irqs_disabled()); |
829 | |
830 | if (!PageSlab(page)) { |
831 | slab_err(s, page, "Not a valid slab page"); |
832 | return 0; |
833 | } |
834 | |
835 | maxobj = order_objects(compound_order(page), s->size, s->reserved); |
836 | if (page->objects > maxobj) { |
837 | slab_err(s, page, "objects %u > max %u", |
838 | s->name, page->objects, maxobj); |
839 | return 0; |
840 | } |
841 | if (page->inuse > page->objects) { |
842 | slab_err(s, page, "inuse %u > max %u", |
843 | s->name, page->inuse, page->objects); |
844 | return 0; |
845 | } |
846 | /* Slab_pad_check fixes things up after itself */ |
847 | slab_pad_check(s, page); |
848 | return 1; |
849 | } |
850 | |
851 | /* |
852 | * Determine if a certain object on a page is on the freelist. Must hold the |
853 | * slab lock to guarantee that the chains are in a consistent state. |
854 | */ |
855 | static int on_freelist(struct kmem_cache *s, struct page *page, void *search) |
856 | { |
857 | int nr = 0; |
858 | void *fp; |
859 | void *object = NULL; |
860 | unsigned long max_objects; |
861 | |
862 | fp = page->freelist; |
863 | while (fp && nr <= page->objects) { |
864 | if (fp == search) |
865 | return 1; |
866 | if (!check_valid_pointer(s, page, fp)) { |
867 | if (object) { |
868 | object_err(s, page, object, |
869 | "Freechain corrupt"); |
870 | set_freepointer(s, object, NULL); |
871 | break; |
872 | } else { |
873 | slab_err(s, page, "Freepointer corrupt"); |
874 | page->freelist = NULL; |
875 | page->inuse = page->objects; |
876 | slab_fix(s, "Freelist cleared"); |
877 | return 0; |
878 | } |
879 | break; |
880 | } |
881 | object = fp; |
882 | fp = get_freepointer(s, object); |
883 | nr++; |
884 | } |
885 | |
886 | max_objects = order_objects(compound_order(page), s->size, s->reserved); |
887 | if (max_objects > MAX_OBJS_PER_PAGE) |
888 | max_objects = MAX_OBJS_PER_PAGE; |
889 | |
890 | if (page->objects != max_objects) { |
891 | slab_err(s, page, "Wrong number of objects. Found %d but " |
892 | "should be %d", page->objects, max_objects); |
893 | page->objects = max_objects; |
894 | slab_fix(s, "Number of objects adjusted."); |
895 | } |
896 | if (page->inuse != page->objects - nr) { |
897 | slab_err(s, page, "Wrong object count. Counter is %d but " |
898 | "counted were %d", page->inuse, page->objects - nr); |
899 | page->inuse = page->objects - nr; |
900 | slab_fix(s, "Object count adjusted."); |
901 | } |
902 | return search == NULL; |
903 | } |
904 | |
905 | static void trace(struct kmem_cache *s, struct page *page, void *object, |
906 | int alloc) |
907 | { |
908 | if (s->flags & SLAB_TRACE) { |
909 | printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n", |
910 | s->name, |
911 | alloc ? "alloc" : "free", |
912 | object, page->inuse, |
913 | page->freelist); |
914 | |
915 | if (!alloc) |
916 | print_section("Object ", (void *)object, s->object_size); |
917 | |
918 | dump_stack(); |
919 | } |
920 | } |
921 | |
922 | /* |
923 | * Hooks for other subsystems that check memory allocations. In a typical |
924 | * production configuration these hooks all should produce no code at all. |
925 | */ |
926 | static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) |
927 | { |
928 | flags &= gfp_allowed_mask; |
929 | lockdep_trace_alloc(flags); |
930 | might_sleep_if(flags & __GFP_WAIT); |
931 | |
932 | return should_failslab(s->object_size, flags, s->flags); |
933 | } |
934 | |
935 | static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object) |
936 | { |
937 | flags &= gfp_allowed_mask; |
938 | kmemcheck_slab_alloc(s, flags, object, slab_ksize(s)); |
939 | kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, flags); |
940 | } |
941 | |
942 | static inline void slab_free_hook(struct kmem_cache *s, void *x) |
943 | { |
944 | kmemleak_free_recursive(x, s->flags); |
945 | |
946 | /* |
947 | * Trouble is that we may no longer disable interupts in the fast path |
948 | * So in order to make the debug calls that expect irqs to be |
949 | * disabled we need to disable interrupts temporarily. |
950 | */ |
951 | #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP) |
952 | { |
953 | unsigned long flags; |
954 | |
955 | local_irq_save(flags); |
956 | kmemcheck_slab_free(s, x, s->object_size); |
957 | debug_check_no_locks_freed(x, s->object_size); |
958 | local_irq_restore(flags); |
959 | } |
960 | #endif |
961 | if (!(s->flags & SLAB_DEBUG_OBJECTS)) |
962 | debug_check_no_obj_freed(x, s->object_size); |
963 | } |
964 | |
965 | /* |
966 | * Tracking of fully allocated slabs for debugging purposes. |
967 | * |
968 | * list_lock must be held. |
969 | */ |
970 | static void add_full(struct kmem_cache *s, |
971 | struct kmem_cache_node *n, struct page *page) |
972 | { |
973 | if (!(s->flags & SLAB_STORE_USER)) |
974 | return; |
975 | |
976 | list_add(&page->lru, &n->full); |
977 | } |
978 | |
979 | /* |
980 | * list_lock must be held. |
981 | */ |
982 | static void remove_full(struct kmem_cache *s, struct page *page) |
983 | { |
984 | if (!(s->flags & SLAB_STORE_USER)) |
985 | return; |
986 | |
987 | list_del(&page->lru); |
988 | } |
989 | |
990 | /* Tracking of the number of slabs for debugging purposes */ |
991 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) |
992 | { |
993 | struct kmem_cache_node *n = get_node(s, node); |
994 | |
995 | return atomic_long_read(&n->nr_slabs); |
996 | } |
997 | |
998 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) |
999 | { |
1000 | return atomic_long_read(&n->nr_slabs); |
1001 | } |
1002 | |
1003 | static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects) |
1004 | { |
1005 | struct kmem_cache_node *n = get_node(s, node); |
1006 | |
1007 | /* |
1008 | * May be called early in order to allocate a slab for the |
1009 | * kmem_cache_node structure. Solve the chicken-egg |
1010 | * dilemma by deferring the increment of the count during |
1011 | * bootstrap (see early_kmem_cache_node_alloc). |
1012 | */ |
1013 | if (n) { |
1014 | atomic_long_inc(&n->nr_slabs); |
1015 | atomic_long_add(objects, &n->total_objects); |
1016 | } |
1017 | } |
1018 | static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects) |
1019 | { |
1020 | struct kmem_cache_node *n = get_node(s, node); |
1021 | |
1022 | atomic_long_dec(&n->nr_slabs); |
1023 | atomic_long_sub(objects, &n->total_objects); |
1024 | } |
1025 | |
1026 | /* Object debug checks for alloc/free paths */ |
1027 | static void setup_object_debug(struct kmem_cache *s, struct page *page, |
1028 | void *object) |
1029 | { |
1030 | if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))) |
1031 | return; |
1032 | |
1033 | init_object(s, object, SLUB_RED_INACTIVE); |
1034 | init_tracking(s, object); |
1035 | } |
1036 | |
1037 | static noinline int alloc_debug_processing(struct kmem_cache *s, struct page *page, |
1038 | void *object, unsigned long addr) |
1039 | { |
1040 | if (!check_slab(s, page)) |
1041 | goto bad; |
1042 | |
1043 | if (!check_valid_pointer(s, page, object)) { |
1044 | object_err(s, page, object, "Freelist Pointer check fails"); |
1045 | goto bad; |
1046 | } |
1047 | |
1048 | if (!check_object(s, page, object, SLUB_RED_INACTIVE)) |
1049 | goto bad; |
1050 | |
1051 | /* Success perform special debug activities for allocs */ |
1052 | if (s->flags & SLAB_STORE_USER) |
1053 | set_track(s, object, TRACK_ALLOC, addr); |
1054 | trace(s, page, object, 1); |
1055 | init_object(s, object, SLUB_RED_ACTIVE); |
1056 | return 1; |
1057 | |
1058 | bad: |
1059 | if (PageSlab(page)) { |
1060 | /* |
1061 | * If this is a slab page then lets do the best we can |
1062 | * to avoid issues in the future. Marking all objects |
1063 | * as used avoids touching the remaining objects. |
1064 | */ |
1065 | slab_fix(s, "Marking all objects used"); |
1066 | page->inuse = page->objects; |
1067 | page->freelist = NULL; |
1068 | } |
1069 | return 0; |
1070 | } |
1071 | |
1072 | static noinline int free_debug_processing(struct kmem_cache *s, |
1073 | struct page *page, void *object, unsigned long addr) |
1074 | { |
1075 | unsigned long flags; |
1076 | int rc = 0; |
1077 | |
1078 | local_irq_save(flags); |
1079 | slab_lock(page); |
1080 | |
1081 | if (!check_slab(s, page)) |
1082 | goto fail; |
1083 | |
1084 | if (!check_valid_pointer(s, page, object)) { |
1085 | slab_err(s, page, "Invalid object pointer 0x%p", object); |
1086 | goto fail; |
1087 | } |
1088 | |
1089 | if (on_freelist(s, page, object)) { |
1090 | object_err(s, page, object, "Object already free"); |
1091 | goto fail; |
1092 | } |
1093 | |
1094 | if (!check_object(s, page, object, SLUB_RED_ACTIVE)) |
1095 | goto out; |
1096 | |
1097 | if (unlikely(s != page->slab)) { |
1098 | if (!PageSlab(page)) { |
1099 | slab_err(s, page, "Attempt to free object(0x%p) " |
1100 | "outside of slab", object); |
1101 | } else if (!page->slab) { |
1102 | printk(KERN_ERR |
1103 | "SLUB <none>: no slab for object 0x%p.\n", |
1104 | object); |
1105 | dump_stack(); |
1106 | } else |
1107 | object_err(s, page, object, |
1108 | "page slab pointer corrupt."); |
1109 | goto fail; |
1110 | } |
1111 | |
1112 | if (s->flags & SLAB_STORE_USER) |
1113 | set_track(s, object, TRACK_FREE, addr); |
1114 | trace(s, page, object, 0); |
1115 | init_object(s, object, SLUB_RED_INACTIVE); |
1116 | rc = 1; |
1117 | out: |
1118 | slab_unlock(page); |
1119 | local_irq_restore(flags); |
1120 | return rc; |
1121 | |
1122 | fail: |
1123 | slab_fix(s, "Object at 0x%p not freed", object); |
1124 | goto out; |
1125 | } |
1126 | |
1127 | static int __init setup_slub_debug(char *str) |
1128 | { |
1129 | slub_debug = DEBUG_DEFAULT_FLAGS; |
1130 | if (*str++ != '=' || !*str) |
1131 | /* |
1132 | * No options specified. Switch on full debugging. |
1133 | */ |
1134 | goto out; |
1135 | |
1136 | if (*str == ',') |
1137 | /* |
1138 | * No options but restriction on slabs. This means full |
1139 | * debugging for slabs matching a pattern. |
1140 | */ |
1141 | goto check_slabs; |
1142 | |
1143 | if (tolower(*str) == 'o') { |
1144 | /* |
1145 | * Avoid enabling debugging on caches if its minimum order |
1146 | * would increase as a result. |
1147 | */ |
1148 | disable_higher_order_debug = 1; |
1149 | goto out; |
1150 | } |
1151 | |
1152 | slub_debug = 0; |
1153 | if (*str == '-') |
1154 | /* |
1155 | * Switch off all debugging measures. |
1156 | */ |
1157 | goto out; |
1158 | |
1159 | /* |
1160 | * Determine which debug features should be switched on |
1161 | */ |
1162 | for (; *str && *str != ','; str++) { |
1163 | switch (tolower(*str)) { |
1164 | case 'f': |
1165 | slub_debug |= SLAB_DEBUG_FREE; |
1166 | break; |
1167 | case 'z': |
1168 | slub_debug |= SLAB_RED_ZONE; |
1169 | break; |
1170 | case 'p': |
1171 | slub_debug |= SLAB_POISON; |
1172 | break; |
1173 | case 'u': |
1174 | slub_debug |= SLAB_STORE_USER; |
1175 | break; |
1176 | case 't': |
1177 | slub_debug |= SLAB_TRACE; |
1178 | break; |
1179 | case 'a': |
1180 | slub_debug |= SLAB_FAILSLAB; |
1181 | break; |
1182 | default: |
1183 | printk(KERN_ERR "slub_debug option '%c' " |
1184 | "unknown. skipped\n", *str); |
1185 | } |
1186 | } |
1187 | |
1188 | check_slabs: |
1189 | if (*str == ',') |
1190 | slub_debug_slabs = str + 1; |
1191 | out: |
1192 | return 1; |
1193 | } |
1194 | |
1195 | __setup("slub_debug", setup_slub_debug); |
1196 | |
1197 | static unsigned long kmem_cache_flags(unsigned long object_size, |
1198 | unsigned long flags, const char *name, |
1199 | void (*ctor)(void *)) |
1200 | { |
1201 | /* |
1202 | * Enable debugging if selected on the kernel commandline. |
1203 | */ |
1204 | if (slub_debug && (!slub_debug_slabs || |
1205 | !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs)))) |
1206 | flags |= slub_debug; |
1207 | |
1208 | return flags; |
1209 | } |
1210 | #else |
1211 | static inline void setup_object_debug(struct kmem_cache *s, |
1212 | struct page *page, void *object) {} |
1213 | |
1214 | static inline int alloc_debug_processing(struct kmem_cache *s, |
1215 | struct page *page, void *object, unsigned long addr) { return 0; } |
1216 | |
1217 | static inline int free_debug_processing(struct kmem_cache *s, |
1218 | struct page *page, void *object, unsigned long addr) { return 0; } |
1219 | |
1220 | static inline int slab_pad_check(struct kmem_cache *s, struct page *page) |
1221 | { return 1; } |
1222 | static inline int check_object(struct kmem_cache *s, struct page *page, |
1223 | void *object, u8 val) { return 1; } |
1224 | static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n, |
1225 | struct page *page) {} |
1226 | static inline void remove_full(struct kmem_cache *s, struct page *page) {} |
1227 | static inline unsigned long kmem_cache_flags(unsigned long object_size, |
1228 | unsigned long flags, const char *name, |
1229 | void (*ctor)(void *)) |
1230 | { |
1231 | return flags; |
1232 | } |
1233 | #define slub_debug 0 |
1234 | |
1235 | #define disable_higher_order_debug 0 |
1236 | |
1237 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) |
1238 | { return 0; } |
1239 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) |
1240 | { return 0; } |
1241 | static inline void inc_slabs_node(struct kmem_cache *s, int node, |
1242 | int objects) {} |
1243 | static inline void dec_slabs_node(struct kmem_cache *s, int node, |
1244 | int objects) {} |
1245 | |
1246 | static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) |
1247 | { return 0; } |
1248 | |
1249 | static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, |
1250 | void *object) {} |
1251 | |
1252 | static inline void slab_free_hook(struct kmem_cache *s, void *x) {} |
1253 | |
1254 | #endif /* CONFIG_SLUB_DEBUG */ |
1255 | |
1256 | /* |
1257 | * Slab allocation and freeing |
1258 | */ |
1259 | static inline struct page *alloc_slab_page(gfp_t flags, int node, |
1260 | struct kmem_cache_order_objects oo) |
1261 | { |
1262 | int order = oo_order(oo); |
1263 | |
1264 | flags |= __GFP_NOTRACK; |
1265 | |
1266 | if (node == NUMA_NO_NODE) |
1267 | return alloc_pages(flags, order); |
1268 | else |
1269 | return alloc_pages_exact_node(node, flags, order); |
1270 | } |
1271 | |
1272 | static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) |
1273 | { |
1274 | struct page *page; |
1275 | struct kmem_cache_order_objects oo = s->oo; |
1276 | gfp_t alloc_gfp; |
1277 | |
1278 | flags &= gfp_allowed_mask; |
1279 | |
1280 | if (flags & __GFP_WAIT) |
1281 | local_irq_enable(); |
1282 | |
1283 | flags |= s->allocflags; |
1284 | |
1285 | /* |
1286 | * Let the initial higher-order allocation fail under memory pressure |
1287 | * so we fall-back to the minimum order allocation. |
1288 | */ |
1289 | alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL; |
1290 | |
1291 | page = alloc_slab_page(alloc_gfp, node, oo); |
1292 | if (unlikely(!page)) { |
1293 | oo = s->min; |
1294 | /* |
1295 | * Allocation may have failed due to fragmentation. |
1296 | * Try a lower order alloc if possible |
1297 | */ |
1298 | page = alloc_slab_page(flags, node, oo); |
1299 | |
1300 | if (page) |
1301 | stat(s, ORDER_FALLBACK); |
1302 | } |
1303 | |
1304 | if (kmemcheck_enabled && page |
1305 | && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) { |
1306 | int pages = 1 << oo_order(oo); |
1307 | |
1308 | kmemcheck_alloc_shadow(page, oo_order(oo), flags, node); |
1309 | |
1310 | /* |
1311 | * Objects from caches that have a constructor don't get |
1312 | * cleared when they're allocated, so we need to do it here. |
1313 | */ |
1314 | if (s->ctor) |
1315 | kmemcheck_mark_uninitialized_pages(page, pages); |
1316 | else |
1317 | kmemcheck_mark_unallocated_pages(page, pages); |
1318 | } |
1319 | |
1320 | if (flags & __GFP_WAIT) |
1321 | local_irq_disable(); |
1322 | if (!page) |
1323 | return NULL; |
1324 | |
1325 | page->objects = oo_objects(oo); |
1326 | mod_zone_page_state(page_zone(page), |
1327 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? |
1328 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, |
1329 | 1 << oo_order(oo)); |
1330 | |
1331 | return page; |
1332 | } |
1333 | |
1334 | static void setup_object(struct kmem_cache *s, struct page *page, |
1335 | void *object) |
1336 | { |
1337 | setup_object_debug(s, page, object); |
1338 | if (unlikely(s->ctor)) |
1339 | s->ctor(object); |
1340 | } |
1341 | |
1342 | static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) |
1343 | { |
1344 | struct page *page; |
1345 | void *start; |
1346 | void *last; |
1347 | void *p; |
1348 | |
1349 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
1350 | |
1351 | page = allocate_slab(s, |
1352 | flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); |
1353 | if (!page) |
1354 | goto out; |
1355 | |
1356 | inc_slabs_node(s, page_to_nid(page), page->objects); |
1357 | page->slab = s; |
1358 | __SetPageSlab(page); |
1359 | if (page->pfmemalloc) |
1360 | SetPageSlabPfmemalloc(page); |
1361 | |
1362 | start = page_address(page); |
1363 | |
1364 | if (unlikely(s->flags & SLAB_POISON)) |
1365 | memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page)); |
1366 | |
1367 | last = start; |
1368 | for_each_object(p, s, start, page->objects) { |
1369 | setup_object(s, page, last); |
1370 | set_freepointer(s, last, p); |
1371 | last = p; |
1372 | } |
1373 | setup_object(s, page, last); |
1374 | set_freepointer(s, last, NULL); |
1375 | |
1376 | page->freelist = start; |
1377 | page->inuse = page->objects; |
1378 | page->frozen = 1; |
1379 | out: |
1380 | return page; |
1381 | } |
1382 | |
1383 | static void __free_slab(struct kmem_cache *s, struct page *page) |
1384 | { |
1385 | int order = compound_order(page); |
1386 | int pages = 1 << order; |
1387 | |
1388 | if (kmem_cache_debug(s)) { |
1389 | void *p; |
1390 | |
1391 | slab_pad_check(s, page); |
1392 | for_each_object(p, s, page_address(page), |
1393 | page->objects) |
1394 | check_object(s, page, p, SLUB_RED_INACTIVE); |
1395 | } |
1396 | |
1397 | kmemcheck_free_shadow(page, compound_order(page)); |
1398 | |
1399 | mod_zone_page_state(page_zone(page), |
1400 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? |
1401 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, |
1402 | -pages); |
1403 | |
1404 | __ClearPageSlabPfmemalloc(page); |
1405 | __ClearPageSlab(page); |
1406 | reset_page_mapcount(page); |
1407 | if (current->reclaim_state) |
1408 | current->reclaim_state->reclaimed_slab += pages; |
1409 | __free_pages(page, order); |
1410 | } |
1411 | |
1412 | #define need_reserve_slab_rcu \ |
1413 | (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head)) |
1414 | |
1415 | static void rcu_free_slab(struct rcu_head *h) |
1416 | { |
1417 | struct page *page; |
1418 | |
1419 | if (need_reserve_slab_rcu) |
1420 | page = virt_to_head_page(h); |
1421 | else |
1422 | page = container_of((struct list_head *)h, struct page, lru); |
1423 | |
1424 | __free_slab(page->slab, page); |
1425 | } |
1426 | |
1427 | static void free_slab(struct kmem_cache *s, struct page *page) |
1428 | { |
1429 | if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { |
1430 | struct rcu_head *head; |
1431 | |
1432 | if (need_reserve_slab_rcu) { |
1433 | int order = compound_order(page); |
1434 | int offset = (PAGE_SIZE << order) - s->reserved; |
1435 | |
1436 | VM_BUG_ON(s->reserved != sizeof(*head)); |
1437 | head = page_address(page) + offset; |
1438 | } else { |
1439 | /* |
1440 | * RCU free overloads the RCU head over the LRU |
1441 | */ |
1442 | head = (void *)&page->lru; |
1443 | } |
1444 | |
1445 | call_rcu(head, rcu_free_slab); |
1446 | } else |
1447 | __free_slab(s, page); |
1448 | } |
1449 | |
1450 | static void discard_slab(struct kmem_cache *s, struct page *page) |
1451 | { |
1452 | dec_slabs_node(s, page_to_nid(page), page->objects); |
1453 | free_slab(s, page); |
1454 | } |
1455 | |
1456 | /* |
1457 | * Management of partially allocated slabs. |
1458 | * |
1459 | * list_lock must be held. |
1460 | */ |
1461 | static inline void add_partial(struct kmem_cache_node *n, |
1462 | struct page *page, int tail) |
1463 | { |
1464 | n->nr_partial++; |
1465 | if (tail == DEACTIVATE_TO_TAIL) |
1466 | list_add_tail(&page->lru, &n->partial); |
1467 | else |
1468 | list_add(&page->lru, &n->partial); |
1469 | } |
1470 | |
1471 | /* |
1472 | * list_lock must be held. |
1473 | */ |
1474 | static inline void remove_partial(struct kmem_cache_node *n, |
1475 | struct page *page) |
1476 | { |
1477 | list_del(&page->lru); |
1478 | n->nr_partial--; |
1479 | } |
1480 | |
1481 | /* |
1482 | * Remove slab from the partial list, freeze it and |
1483 | * return the pointer to the freelist. |
1484 | * |
1485 | * Returns a list of objects or NULL if it fails. |
1486 | * |
1487 | * Must hold list_lock since we modify the partial list. |
1488 | */ |
1489 | static inline void *acquire_slab(struct kmem_cache *s, |
1490 | struct kmem_cache_node *n, struct page *page, |
1491 | int mode) |
1492 | { |
1493 | void *freelist; |
1494 | unsigned long counters; |
1495 | struct page new; |
1496 | |
1497 | /* |
1498 | * Zap the freelist and set the frozen bit. |
1499 | * The old freelist is the list of objects for the |
1500 | * per cpu allocation list. |
1501 | */ |
1502 | freelist = page->freelist; |
1503 | counters = page->counters; |
1504 | new.counters = counters; |
1505 | if (mode) { |
1506 | new.inuse = page->objects; |
1507 | new.freelist = NULL; |
1508 | } else { |
1509 | new.freelist = freelist; |
1510 | } |
1511 | |
1512 | VM_BUG_ON(new.frozen); |
1513 | new.frozen = 1; |
1514 | |
1515 | if (!__cmpxchg_double_slab(s, page, |
1516 | freelist, counters, |
1517 | new.freelist, new.counters, |
1518 | "acquire_slab")) |
1519 | return NULL; |
1520 | |
1521 | remove_partial(n, page); |
1522 | WARN_ON(!freelist); |
1523 | return freelist; |
1524 | } |
1525 | |
1526 | static int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain); |
1527 | static inline bool pfmemalloc_match(struct page *page, gfp_t gfpflags); |
1528 | |
1529 | /* |
1530 | * Try to allocate a partial slab from a specific node. |
1531 | */ |
1532 | static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, |
1533 | struct kmem_cache_cpu *c, gfp_t flags) |
1534 | { |
1535 | struct page *page, *page2; |
1536 | void *object = NULL; |
1537 | |
1538 | /* |
1539 | * Racy check. If we mistakenly see no partial slabs then we |
1540 | * just allocate an empty slab. If we mistakenly try to get a |
1541 | * partial slab and there is none available then get_partials() |
1542 | * will return NULL. |
1543 | */ |
1544 | if (!n || !n->nr_partial) |
1545 | return NULL; |
1546 | |
1547 | spin_lock(&n->list_lock); |
1548 | list_for_each_entry_safe(page, page2, &n->partial, lru) { |
1549 | void *t; |
1550 | int available; |
1551 | |
1552 | if (!pfmemalloc_match(page, flags)) |
1553 | continue; |
1554 | |
1555 | t = acquire_slab(s, n, page, object == NULL); |
1556 | if (!t) |
1557 | break; |
1558 | |
1559 | if (!object) { |
1560 | c->page = page; |
1561 | stat(s, ALLOC_FROM_PARTIAL); |
1562 | object = t; |
1563 | available = page->objects - page->inuse; |
1564 | } else { |
1565 | available = put_cpu_partial(s, page, 0); |
1566 | stat(s, CPU_PARTIAL_NODE); |
1567 | } |
1568 | if (kmem_cache_debug(s) || available > s->cpu_partial / 2) |
1569 | break; |
1570 | |
1571 | } |
1572 | spin_unlock(&n->list_lock); |
1573 | return object; |
1574 | } |
1575 | |
1576 | /* |
1577 | * Get a page from somewhere. Search in increasing NUMA distances. |
1578 | */ |
1579 | static void *get_any_partial(struct kmem_cache *s, gfp_t flags, |
1580 | struct kmem_cache_cpu *c) |
1581 | { |
1582 | #ifdef CONFIG_NUMA |
1583 | struct zonelist *zonelist; |
1584 | struct zoneref *z; |
1585 | struct zone *zone; |
1586 | enum zone_type high_zoneidx = gfp_zone(flags); |
1587 | void *object; |
1588 | unsigned int cpuset_mems_cookie; |
1589 | |
1590 | /* |
1591 | * The defrag ratio allows a configuration of the tradeoffs between |
1592 | * inter node defragmentation and node local allocations. A lower |
1593 | * defrag_ratio increases the tendency to do local allocations |
1594 | * instead of attempting to obtain partial slabs from other nodes. |
1595 | * |
1596 | * If the defrag_ratio is set to 0 then kmalloc() always |
1597 | * returns node local objects. If the ratio is higher then kmalloc() |
1598 | * may return off node objects because partial slabs are obtained |
1599 | * from other nodes and filled up. |
1600 | * |
1601 | * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes |
1602 | * defrag_ratio = 1000) then every (well almost) allocation will |
1603 | * first attempt to defrag slab caches on other nodes. This means |
1604 | * scanning over all nodes to look for partial slabs which may be |
1605 | * expensive if we do it every time we are trying to find a slab |
1606 | * with available objects. |
1607 | */ |
1608 | if (!s->remote_node_defrag_ratio || |
1609 | get_cycles() % 1024 > s->remote_node_defrag_ratio) |
1610 | return NULL; |
1611 | |
1612 | do { |
1613 | cpuset_mems_cookie = get_mems_allowed(); |
1614 | zonelist = node_zonelist(slab_node(), flags); |
1615 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
1616 | struct kmem_cache_node *n; |
1617 | |
1618 | n = get_node(s, zone_to_nid(zone)); |
1619 | |
1620 | if (n && cpuset_zone_allowed_hardwall(zone, flags) && |
1621 | n->nr_partial > s->min_partial) { |
1622 | object = get_partial_node(s, n, c, flags); |
1623 | if (object) { |
1624 | /* |
1625 | * Return the object even if |
1626 | * put_mems_allowed indicated that |
1627 | * the cpuset mems_allowed was |
1628 | * updated in parallel. It's a |
1629 | * harmless race between the alloc |
1630 | * and the cpuset update. |
1631 | */ |
1632 | put_mems_allowed(cpuset_mems_cookie); |
1633 | return object; |
1634 | } |
1635 | } |
1636 | } |
1637 | } while (!put_mems_allowed(cpuset_mems_cookie)); |
1638 | #endif |
1639 | return NULL; |
1640 | } |
1641 | |
1642 | /* |
1643 | * Get a partial page, lock it and return it. |
1644 | */ |
1645 | static void *get_partial(struct kmem_cache *s, gfp_t flags, int node, |
1646 | struct kmem_cache_cpu *c) |
1647 | { |
1648 | void *object; |
1649 | int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node; |
1650 | |
1651 | object = get_partial_node(s, get_node(s, searchnode), c, flags); |
1652 | if (object || node != NUMA_NO_NODE) |
1653 | return object; |
1654 | |
1655 | return get_any_partial(s, flags, c); |
1656 | } |
1657 | |
1658 | #ifdef CONFIG_PREEMPT |
1659 | /* |
1660 | * Calculate the next globally unique transaction for disambiguiation |
1661 | * during cmpxchg. The transactions start with the cpu number and are then |
1662 | * incremented by CONFIG_NR_CPUS. |
1663 | */ |
1664 | #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS) |
1665 | #else |
1666 | /* |
1667 | * No preemption supported therefore also no need to check for |
1668 | * different cpus. |
1669 | */ |
1670 | #define TID_STEP 1 |
1671 | #endif |
1672 | |
1673 | static inline unsigned long next_tid(unsigned long tid) |
1674 | { |
1675 | return tid + TID_STEP; |
1676 | } |
1677 | |
1678 | static inline unsigned int tid_to_cpu(unsigned long tid) |
1679 | { |
1680 | return tid % TID_STEP; |
1681 | } |
1682 | |
1683 | static inline unsigned long tid_to_event(unsigned long tid) |
1684 | { |
1685 | return tid / TID_STEP; |
1686 | } |
1687 | |
1688 | static inline unsigned int init_tid(int cpu) |
1689 | { |
1690 | return cpu; |
1691 | } |
1692 | |
1693 | static inline void note_cmpxchg_failure(const char *n, |
1694 | const struct kmem_cache *s, unsigned long tid) |
1695 | { |
1696 | #ifdef SLUB_DEBUG_CMPXCHG |
1697 | unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid); |
1698 | |
1699 | printk(KERN_INFO "%s %s: cmpxchg redo ", n, s->name); |
1700 | |
1701 | #ifdef CONFIG_PREEMPT |
1702 | if (tid_to_cpu(tid) != tid_to_cpu(actual_tid)) |
1703 | printk("due to cpu change %d -> %d\n", |
1704 | tid_to_cpu(tid), tid_to_cpu(actual_tid)); |
1705 | else |
1706 | #endif |
1707 | if (tid_to_event(tid) != tid_to_event(actual_tid)) |
1708 | printk("due to cpu running other code. Event %ld->%ld\n", |
1709 | tid_to_event(tid), tid_to_event(actual_tid)); |
1710 | else |
1711 | printk("for unknown reason: actual=%lx was=%lx target=%lx\n", |
1712 | actual_tid, tid, next_tid(tid)); |
1713 | #endif |
1714 | stat(s, CMPXCHG_DOUBLE_CPU_FAIL); |
1715 | } |
1716 | |
1717 | void init_kmem_cache_cpus(struct kmem_cache *s) |
1718 | { |
1719 | int cpu; |
1720 | |
1721 | for_each_possible_cpu(cpu) |
1722 | per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu); |
1723 | } |
1724 | |
1725 | /* |
1726 | * Remove the cpu slab |
1727 | */ |
1728 | static void deactivate_slab(struct kmem_cache *s, struct page *page, void *freelist) |
1729 | { |
1730 | enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE }; |
1731 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); |
1732 | int lock = 0; |
1733 | enum slab_modes l = M_NONE, m = M_NONE; |
1734 | void *nextfree; |
1735 | int tail = DEACTIVATE_TO_HEAD; |
1736 | struct page new; |
1737 | struct page old; |
1738 | |
1739 | if (page->freelist) { |
1740 | stat(s, DEACTIVATE_REMOTE_FREES); |
1741 | tail = DEACTIVATE_TO_TAIL; |
1742 | } |
1743 | |
1744 | /* |
1745 | * Stage one: Free all available per cpu objects back |
1746 | * to the page freelist while it is still frozen. Leave the |
1747 | * last one. |
1748 | * |
1749 | * There is no need to take the list->lock because the page |
1750 | * is still frozen. |
1751 | */ |
1752 | while (freelist && (nextfree = get_freepointer(s, freelist))) { |
1753 | void *prior; |
1754 | unsigned long counters; |
1755 | |
1756 | do { |
1757 | prior = page->freelist; |
1758 | counters = page->counters; |
1759 | set_freepointer(s, freelist, prior); |
1760 | new.counters = counters; |
1761 | new.inuse--; |
1762 | VM_BUG_ON(!new.frozen); |
1763 | |
1764 | } while (!__cmpxchg_double_slab(s, page, |
1765 | prior, counters, |
1766 | freelist, new.counters, |
1767 | "drain percpu freelist")); |
1768 | |
1769 | freelist = nextfree; |
1770 | } |
1771 | |
1772 | /* |
1773 | * Stage two: Ensure that the page is unfrozen while the |
1774 | * list presence reflects the actual number of objects |
1775 | * during unfreeze. |
1776 | * |
1777 | * We setup the list membership and then perform a cmpxchg |
1778 | * with the count. If there is a mismatch then the page |
1779 | * is not unfrozen but the page is on the wrong list. |
1780 | * |
1781 | * Then we restart the process which may have to remove |
1782 | * the page from the list that we just put it on again |
1783 | * because the number of objects in the slab may have |
1784 | * changed. |
1785 | */ |
1786 | redo: |
1787 | |
1788 | old.freelist = page->freelist; |
1789 | old.counters = page->counters; |
1790 | VM_BUG_ON(!old.frozen); |
1791 | |
1792 | /* Determine target state of the slab */ |
1793 | new.counters = old.counters; |
1794 | if (freelist) { |
1795 | new.inuse--; |
1796 | set_freepointer(s, freelist, old.freelist); |
1797 | new.freelist = freelist; |
1798 | } else |
1799 | new.freelist = old.freelist; |
1800 | |
1801 | new.frozen = 0; |
1802 | |
1803 | if (!new.inuse && n->nr_partial > s->min_partial) |
1804 | m = M_FREE; |
1805 | else if (new.freelist) { |
1806 | m = M_PARTIAL; |
1807 | if (!lock) { |
1808 | lock = 1; |
1809 | /* |
1810 | * Taking the spinlock removes the possiblity |
1811 | * that acquire_slab() will see a slab page that |
1812 | * is frozen |
1813 | */ |
1814 | spin_lock(&n->list_lock); |
1815 | } |
1816 | } else { |
1817 | m = M_FULL; |
1818 | if (kmem_cache_debug(s) && !lock) { |
1819 | lock = 1; |
1820 | /* |
1821 | * This also ensures that the scanning of full |
1822 | * slabs from diagnostic functions will not see |
1823 | * any frozen slabs. |
1824 | */ |
1825 | spin_lock(&n->list_lock); |
1826 | } |
1827 | } |
1828 | |
1829 | if (l != m) { |
1830 | |
1831 | if (l == M_PARTIAL) |
1832 | |
1833 | remove_partial(n, page); |
1834 | |
1835 | else if (l == M_FULL) |
1836 | |
1837 | remove_full(s, page); |
1838 | |
1839 | if (m == M_PARTIAL) { |
1840 | |
1841 | add_partial(n, page, tail); |
1842 | stat(s, tail); |
1843 | |
1844 | } else if (m == M_FULL) { |
1845 | |
1846 | stat(s, DEACTIVATE_FULL); |
1847 | add_full(s, n, page); |
1848 | |
1849 | } |
1850 | } |
1851 | |
1852 | l = m; |
1853 | if (!__cmpxchg_double_slab(s, page, |
1854 | old.freelist, old.counters, |
1855 | new.freelist, new.counters, |
1856 | "unfreezing slab")) |
1857 | goto redo; |
1858 | |
1859 | if (lock) |
1860 | spin_unlock(&n->list_lock); |
1861 | |
1862 | if (m == M_FREE) { |
1863 | stat(s, DEACTIVATE_EMPTY); |
1864 | discard_slab(s, page); |
1865 | stat(s, FREE_SLAB); |
1866 | } |
1867 | } |
1868 | |
1869 | /* |
1870 | * Unfreeze all the cpu partial slabs. |
1871 | * |
1872 | * This function must be called with interrupt disabled. |
1873 | */ |
1874 | static void unfreeze_partials(struct kmem_cache *s) |
1875 | { |
1876 | struct kmem_cache_node *n = NULL, *n2 = NULL; |
1877 | struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab); |
1878 | struct page *page, *discard_page = NULL; |
1879 | |
1880 | while ((page = c->partial)) { |
1881 | struct page new; |
1882 | struct page old; |
1883 | |
1884 | c->partial = page->next; |
1885 | |
1886 | n2 = get_node(s, page_to_nid(page)); |
1887 | if (n != n2) { |
1888 | if (n) |
1889 | spin_unlock(&n->list_lock); |
1890 | |
1891 | n = n2; |
1892 | spin_lock(&n->list_lock); |
1893 | } |
1894 | |
1895 | do { |
1896 | |
1897 | old.freelist = page->freelist; |
1898 | old.counters = page->counters; |
1899 | VM_BUG_ON(!old.frozen); |
1900 | |
1901 | new.counters = old.counters; |
1902 | new.freelist = old.freelist; |
1903 | |
1904 | new.frozen = 0; |
1905 | |
1906 | } while (!__cmpxchg_double_slab(s, page, |
1907 | old.freelist, old.counters, |
1908 | new.freelist, new.counters, |
1909 | "unfreezing slab")); |
1910 | |
1911 | if (unlikely(!new.inuse && n->nr_partial > s->min_partial)) { |
1912 | page->next = discard_page; |
1913 | discard_page = page; |
1914 | } else { |
1915 | add_partial(n, page, DEACTIVATE_TO_TAIL); |
1916 | stat(s, FREE_ADD_PARTIAL); |
1917 | } |
1918 | } |
1919 | |
1920 | if (n) |
1921 | spin_unlock(&n->list_lock); |
1922 | |
1923 | while (discard_page) { |
1924 | page = discard_page; |
1925 | discard_page = discard_page->next; |
1926 | |
1927 | stat(s, DEACTIVATE_EMPTY); |
1928 | discard_slab(s, page); |
1929 | stat(s, FREE_SLAB); |
1930 | } |
1931 | } |
1932 | |
1933 | /* |
1934 | * Put a page that was just frozen (in __slab_free) into a partial page |
1935 | * slot if available. This is done without interrupts disabled and without |
1936 | * preemption disabled. The cmpxchg is racy and may put the partial page |
1937 | * onto a random cpus partial slot. |
1938 | * |
1939 | * If we did not find a slot then simply move all the partials to the |
1940 | * per node partial list. |
1941 | */ |
1942 | int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) |
1943 | { |
1944 | struct page *oldpage; |
1945 | int pages; |
1946 | int pobjects; |
1947 | |
1948 | do { |
1949 | pages = 0; |
1950 | pobjects = 0; |
1951 | oldpage = this_cpu_read(s->cpu_slab->partial); |
1952 | |
1953 | if (oldpage) { |
1954 | pobjects = oldpage->pobjects; |
1955 | pages = oldpage->pages; |
1956 | if (drain && pobjects > s->cpu_partial) { |
1957 | unsigned long flags; |
1958 | /* |
1959 | * partial array is full. Move the existing |
1960 | * set to the per node partial list. |
1961 | */ |
1962 | local_irq_save(flags); |
1963 | unfreeze_partials(s); |
1964 | local_irq_restore(flags); |
1965 | pobjects = 0; |
1966 | pages = 0; |
1967 | stat(s, CPU_PARTIAL_DRAIN); |
1968 | } |
1969 | } |
1970 | |
1971 | pages++; |
1972 | pobjects += page->objects - page->inuse; |
1973 | |
1974 | page->pages = pages; |
1975 | page->pobjects = pobjects; |
1976 | page->next = oldpage; |
1977 | |
1978 | } while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage); |
1979 | return pobjects; |
1980 | } |
1981 | |
1982 | static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) |
1983 | { |
1984 | stat(s, CPUSLAB_FLUSH); |
1985 | deactivate_slab(s, c->page, c->freelist); |
1986 | |
1987 | c->tid = next_tid(c->tid); |
1988 | c->page = NULL; |
1989 | c->freelist = NULL; |
1990 | } |
1991 | |
1992 | /* |
1993 | * Flush cpu slab. |
1994 | * |
1995 | * Called from IPI handler with interrupts disabled. |
1996 | */ |
1997 | static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) |
1998 | { |
1999 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); |
2000 | |
2001 | if (likely(c)) { |
2002 | if (c->page) |
2003 | flush_slab(s, c); |
2004 | |
2005 | unfreeze_partials(s); |
2006 | } |
2007 | } |
2008 | |
2009 | static void flush_cpu_slab(void *d) |
2010 | { |
2011 | struct kmem_cache *s = d; |
2012 | |
2013 | __flush_cpu_slab(s, smp_processor_id()); |
2014 | } |
2015 | |
2016 | static bool has_cpu_slab(int cpu, void *info) |
2017 | { |
2018 | struct kmem_cache *s = info; |
2019 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); |
2020 | |
2021 | return c->page || c->partial; |
2022 | } |
2023 | |
2024 | static void flush_all(struct kmem_cache *s) |
2025 | { |
2026 | on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC); |
2027 | } |
2028 | |
2029 | /* |
2030 | * Check if the objects in a per cpu structure fit numa |
2031 | * locality expectations. |
2032 | */ |
2033 | static inline int node_match(struct page *page, int node) |
2034 | { |
2035 | #ifdef CONFIG_NUMA |
2036 | if (node != NUMA_NO_NODE && page_to_nid(page) != node) |
2037 | return 0; |
2038 | #endif |
2039 | return 1; |
2040 | } |
2041 | |
2042 | static int count_free(struct page *page) |
2043 | { |
2044 | return page->objects - page->inuse; |
2045 | } |
2046 | |
2047 | static unsigned long count_partial(struct kmem_cache_node *n, |
2048 | int (*get_count)(struct page *)) |
2049 | { |
2050 | unsigned long flags; |
2051 | unsigned long x = 0; |
2052 | struct page *page; |
2053 | |
2054 | spin_lock_irqsave(&n->list_lock, flags); |
2055 | list_for_each_entry(page, &n->partial, lru) |
2056 | x += get_count(page); |
2057 | spin_unlock_irqrestore(&n->list_lock, flags); |
2058 | return x; |
2059 | } |
2060 | |
2061 | static inline unsigned long node_nr_objs(struct kmem_cache_node *n) |
2062 | { |
2063 | #ifdef CONFIG_SLUB_DEBUG |
2064 | return atomic_long_read(&n->total_objects); |
2065 | #else |
2066 | return 0; |
2067 | #endif |
2068 | } |
2069 | |
2070 | static noinline void |
2071 | slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) |
2072 | { |
2073 | int node; |
2074 | |
2075 | printk(KERN_WARNING |
2076 | "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
2077 | nid, gfpflags); |
2078 | printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, " |
2079 | "default order: %d, min order: %d\n", s->name, s->object_size, |
2080 | s->size, oo_order(s->oo), oo_order(s->min)); |
2081 | |
2082 | if (oo_order(s->min) > get_order(s->object_size)) |
2083 | printk(KERN_WARNING " %s debugging increased min order, use " |
2084 | "slub_debug=O to disable.\n", s->name); |
2085 | |
2086 | for_each_online_node(node) { |
2087 | struct kmem_cache_node *n = get_node(s, node); |
2088 | unsigned long nr_slabs; |
2089 | unsigned long nr_objs; |
2090 | unsigned long nr_free; |
2091 | |
2092 | if (!n) |
2093 | continue; |
2094 | |
2095 | nr_free = count_partial(n, count_free); |
2096 | nr_slabs = node_nr_slabs(n); |
2097 | nr_objs = node_nr_objs(n); |
2098 | |
2099 | printk(KERN_WARNING |
2100 | " node %d: slabs: %ld, objs: %ld, free: %ld\n", |
2101 | node, nr_slabs, nr_objs, nr_free); |
2102 | } |
2103 | } |
2104 | |
2105 | static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags, |
2106 | int node, struct kmem_cache_cpu **pc) |
2107 | { |
2108 | void *freelist; |
2109 | struct kmem_cache_cpu *c = *pc; |
2110 | struct page *page; |
2111 | |
2112 | freelist = get_partial(s, flags, node, c); |
2113 | |
2114 | if (freelist) |
2115 | return freelist; |
2116 | |
2117 | page = new_slab(s, flags, node); |
2118 | if (page) { |
2119 | c = __this_cpu_ptr(s->cpu_slab); |
2120 | if (c->page) |
2121 | flush_slab(s, c); |
2122 | |
2123 | /* |
2124 | * No other reference to the page yet so we can |
2125 | * muck around with it freely without cmpxchg |
2126 | */ |
2127 | freelist = page->freelist; |
2128 | page->freelist = NULL; |
2129 | |
2130 | stat(s, ALLOC_SLAB); |
2131 | c->page = page; |
2132 | *pc = c; |
2133 | } else |
2134 | freelist = NULL; |
2135 | |
2136 | return freelist; |
2137 | } |
2138 | |
2139 | static inline bool pfmemalloc_match(struct page *page, gfp_t gfpflags) |
2140 | { |
2141 | if (unlikely(PageSlabPfmemalloc(page))) |
2142 | return gfp_pfmemalloc_allowed(gfpflags); |
2143 | |
2144 | return true; |
2145 | } |
2146 | |
2147 | /* |
2148 | * Check the page->freelist of a page and either transfer the freelist to the per cpu freelist |
2149 | * or deactivate the page. |
2150 | * |
2151 | * The page is still frozen if the return value is not NULL. |
2152 | * |
2153 | * If this function returns NULL then the page has been unfrozen. |
2154 | * |
2155 | * This function must be called with interrupt disabled. |
2156 | */ |
2157 | static inline void *get_freelist(struct kmem_cache *s, struct page *page) |
2158 | { |
2159 | struct page new; |
2160 | unsigned long counters; |
2161 | void *freelist; |
2162 | |
2163 | do { |
2164 | freelist = page->freelist; |
2165 | counters = page->counters; |
2166 | |
2167 | new.counters = counters; |
2168 | VM_BUG_ON(!new.frozen); |
2169 | |
2170 | new.inuse = page->objects; |
2171 | new.frozen = freelist != NULL; |
2172 | |
2173 | } while (!__cmpxchg_double_slab(s, page, |
2174 | freelist, counters, |
2175 | NULL, new.counters, |
2176 | "get_freelist")); |
2177 | |
2178 | return freelist; |
2179 | } |
2180 | |
2181 | /* |
2182 | * Slow path. The lockless freelist is empty or we need to perform |
2183 | * debugging duties. |
2184 | * |
2185 | * Processing is still very fast if new objects have been freed to the |
2186 | * regular freelist. In that case we simply take over the regular freelist |
2187 | * as the lockless freelist and zap the regular freelist. |
2188 | * |
2189 | * If that is not working then we fall back to the partial lists. We take the |
2190 | * first element of the freelist as the object to allocate now and move the |
2191 | * rest of the freelist to the lockless freelist. |
2192 | * |
2193 | * And if we were unable to get a new slab from the partial slab lists then |
2194 | * we need to allocate a new slab. This is the slowest path since it involves |
2195 | * a call to the page allocator and the setup of a new slab. |
2196 | */ |
2197 | static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, |
2198 | unsigned long addr, struct kmem_cache_cpu *c) |
2199 | { |
2200 | void *freelist; |
2201 | struct page *page; |
2202 | unsigned long flags; |
2203 | |
2204 | local_irq_save(flags); |
2205 | #ifdef CONFIG_PREEMPT |
2206 | /* |
2207 | * We may have been preempted and rescheduled on a different |
2208 | * cpu before disabling interrupts. Need to reload cpu area |
2209 | * pointer. |
2210 | */ |
2211 | c = this_cpu_ptr(s->cpu_slab); |
2212 | #endif |
2213 | |
2214 | page = c->page; |
2215 | if (!page) |
2216 | goto new_slab; |
2217 | redo: |
2218 | |
2219 | if (unlikely(!node_match(page, node))) { |
2220 | stat(s, ALLOC_NODE_MISMATCH); |
2221 | deactivate_slab(s, page, c->freelist); |
2222 | c->page = NULL; |
2223 | c->freelist = NULL; |
2224 | goto new_slab; |
2225 | } |
2226 | |
2227 | /* |
2228 | * By rights, we should be searching for a slab page that was |
2229 | * PFMEMALLOC but right now, we are losing the pfmemalloc |
2230 | * information when the page leaves the per-cpu allocator |
2231 | */ |
2232 | if (unlikely(!pfmemalloc_match(page, gfpflags))) { |
2233 | deactivate_slab(s, page, c->freelist); |
2234 | c->page = NULL; |
2235 | c->freelist = NULL; |
2236 | goto new_slab; |
2237 | } |
2238 | |
2239 | /* must check again c->freelist in case of cpu migration or IRQ */ |
2240 | freelist = c->freelist; |
2241 | if (freelist) |
2242 | goto load_freelist; |
2243 | |
2244 | stat(s, ALLOC_SLOWPATH); |
2245 | |
2246 | freelist = get_freelist(s, page); |
2247 | |
2248 | if (!freelist) { |
2249 | c->page = NULL; |
2250 | stat(s, DEACTIVATE_BYPASS); |
2251 | goto new_slab; |
2252 | } |
2253 | |
2254 | stat(s, ALLOC_REFILL); |
2255 | |
2256 | load_freelist: |
2257 | /* |
2258 | * freelist is pointing to the list of objects to be used. |
2259 | * page is pointing to the page from which the objects are obtained. |
2260 | * That page must be frozen for per cpu allocations to work. |
2261 | */ |
2262 | VM_BUG_ON(!c->page->frozen); |
2263 | c->freelist = get_freepointer(s, freelist); |
2264 | c->tid = next_tid(c->tid); |
2265 | local_irq_restore(flags); |
2266 | return freelist; |
2267 | |
2268 | new_slab: |
2269 | |
2270 | if (c->partial) { |
2271 | page = c->page = c->partial; |
2272 | c->partial = page->next; |
2273 | stat(s, CPU_PARTIAL_ALLOC); |
2274 | c->freelist = NULL; |
2275 | goto redo; |
2276 | } |
2277 | |
2278 | freelist = new_slab_objects(s, gfpflags, node, &c); |
2279 | |
2280 | if (unlikely(!freelist)) { |
2281 | if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit()) |
2282 | slab_out_of_memory(s, gfpflags, node); |
2283 | |
2284 | local_irq_restore(flags); |
2285 | return NULL; |
2286 | } |
2287 | |
2288 | page = c->page; |
2289 | if (likely(!kmem_cache_debug(s) && pfmemalloc_match(page, gfpflags))) |
2290 | goto load_freelist; |
2291 | |
2292 | /* Only entered in the debug case */ |
2293 | if (kmem_cache_debug(s) && !alloc_debug_processing(s, page, freelist, addr)) |
2294 | goto new_slab; /* Slab failed checks. Next slab needed */ |
2295 | |
2296 | deactivate_slab(s, page, get_freepointer(s, freelist)); |
2297 | c->page = NULL; |
2298 | c->freelist = NULL; |
2299 | local_irq_restore(flags); |
2300 | return freelist; |
2301 | } |
2302 | |
2303 | /* |
2304 | * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc) |
2305 | * have the fastpath folded into their functions. So no function call |
2306 | * overhead for requests that can be satisfied on the fastpath. |
2307 | * |
2308 | * The fastpath works by first checking if the lockless freelist can be used. |
2309 | * If not then __slab_alloc is called for slow processing. |
2310 | * |
2311 | * Otherwise we can simply pick the next object from the lockless free list. |
2312 | */ |
2313 | static __always_inline void *slab_alloc(struct kmem_cache *s, |
2314 | gfp_t gfpflags, int node, unsigned long addr) |
2315 | { |
2316 | void **object; |
2317 | struct kmem_cache_cpu *c; |
2318 | struct page *page; |
2319 | unsigned long tid; |
2320 | |
2321 | if (slab_pre_alloc_hook(s, gfpflags)) |
2322 | return NULL; |
2323 | |
2324 | redo: |
2325 | |
2326 | /* |
2327 | * Must read kmem_cache cpu data via this cpu ptr. Preemption is |
2328 | * enabled. We may switch back and forth between cpus while |
2329 | * reading from one cpu area. That does not matter as long |
2330 | * as we end up on the original cpu again when doing the cmpxchg. |
2331 | */ |
2332 | c = __this_cpu_ptr(s->cpu_slab); |
2333 | |
2334 | /* |
2335 | * The transaction ids are globally unique per cpu and per operation on |
2336 | * a per cpu queue. Thus they can be guarantee that the cmpxchg_double |
2337 | * occurs on the right processor and that there was no operation on the |
2338 | * linked list in between. |
2339 | */ |
2340 | tid = c->tid; |
2341 | barrier(); |
2342 | |
2343 | object = c->freelist; |
2344 | page = c->page; |
2345 | if (unlikely(!object || !node_match(page, node))) |
2346 | object = __slab_alloc(s, gfpflags, node, addr, c); |
2347 | |
2348 | else { |
2349 | void *next_object = get_freepointer_safe(s, object); |
2350 | |
2351 | /* |
2352 | * The cmpxchg will only match if there was no additional |
2353 | * operation and if we are on the right processor. |
2354 | * |
2355 | * The cmpxchg does the following atomically (without lock semantics!) |
2356 | * 1. Relocate first pointer to the current per cpu area. |
2357 | * 2. Verify that tid and freelist have not been changed |
2358 | * 3. If they were not changed replace tid and freelist |
2359 | * |
2360 | * Since this is without lock semantics the protection is only against |
2361 | * code executing on this cpu *not* from access by other cpus. |
2362 | */ |
2363 | if (unlikely(!this_cpu_cmpxchg_double( |
2364 | s->cpu_slab->freelist, s->cpu_slab->tid, |
2365 | object, tid, |
2366 | next_object, next_tid(tid)))) { |
2367 | |
2368 | note_cmpxchg_failure("slab_alloc", s, tid); |
2369 | goto redo; |
2370 | } |
2371 | prefetch_freepointer(s, next_object); |
2372 | stat(s, ALLOC_FASTPATH); |
2373 | } |
2374 | |
2375 | if (unlikely(gfpflags & __GFP_ZERO) && object) |
2376 | memset(object, 0, s->object_size); |
2377 | |
2378 | slab_post_alloc_hook(s, gfpflags, object); |
2379 | |
2380 | return object; |
2381 | } |
2382 | |
2383 | void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) |
2384 | { |
2385 | void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_); |
2386 | |
2387 | trace_kmem_cache_alloc(_RET_IP_, ret, s->object_size, s->size, gfpflags); |
2388 | |
2389 | return ret; |
2390 | } |
2391 | EXPORT_SYMBOL(kmem_cache_alloc); |
2392 | |
2393 | #ifdef CONFIG_TRACING |
2394 | void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size) |
2395 | { |
2396 | void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_); |
2397 | trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags); |
2398 | return ret; |
2399 | } |
2400 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
2401 | |
2402 | void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) |
2403 | { |
2404 | void *ret = kmalloc_order(size, flags, order); |
2405 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags); |
2406 | return ret; |
2407 | } |
2408 | EXPORT_SYMBOL(kmalloc_order_trace); |
2409 | #endif |
2410 | |
2411 | #ifdef CONFIG_NUMA |
2412 | void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node) |
2413 | { |
2414 | void *ret = slab_alloc(s, gfpflags, node, _RET_IP_); |
2415 | |
2416 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
2417 | s->object_size, s->size, gfpflags, node); |
2418 | |
2419 | return ret; |
2420 | } |
2421 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
2422 | |
2423 | #ifdef CONFIG_TRACING |
2424 | void *kmem_cache_alloc_node_trace(struct kmem_cache *s, |
2425 | gfp_t gfpflags, |
2426 | int node, size_t size) |
2427 | { |
2428 | void *ret = slab_alloc(s, gfpflags, node, _RET_IP_); |
2429 | |
2430 | trace_kmalloc_node(_RET_IP_, ret, |
2431 | size, s->size, gfpflags, node); |
2432 | return ret; |
2433 | } |
2434 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
2435 | #endif |
2436 | #endif |
2437 | |
2438 | /* |
2439 | * Slow patch handling. This may still be called frequently since objects |
2440 | * have a longer lifetime than the cpu slabs in most processing loads. |
2441 | * |
2442 | * So we still attempt to reduce cache line usage. Just take the slab |
2443 | * lock and free the item. If there is no additional partial page |
2444 | * handling required then we can return immediately. |
2445 | */ |
2446 | static void __slab_free(struct kmem_cache *s, struct page *page, |
2447 | void *x, unsigned long addr) |
2448 | { |
2449 | void *prior; |
2450 | void **object = (void *)x; |
2451 | int was_frozen; |
2452 | int inuse; |
2453 | struct page new; |
2454 | unsigned long counters; |
2455 | struct kmem_cache_node *n = NULL; |
2456 | unsigned long uninitialized_var(flags); |
2457 | |
2458 | stat(s, FREE_SLOWPATH); |
2459 | |
2460 | if (kmem_cache_debug(s) && !free_debug_processing(s, page, x, addr)) |
2461 | return; |
2462 | |
2463 | do { |
2464 | prior = page->freelist; |
2465 | counters = page->counters; |
2466 | set_freepointer(s, object, prior); |
2467 | new.counters = counters; |
2468 | was_frozen = new.frozen; |
2469 | new.inuse--; |
2470 | if ((!new.inuse || !prior) && !was_frozen && !n) { |
2471 | |
2472 | if (!kmem_cache_debug(s) && !prior) |
2473 | |
2474 | /* |
2475 | * Slab was on no list before and will be partially empty |
2476 | * We can defer the list move and instead freeze it. |
2477 | */ |
2478 | new.frozen = 1; |
2479 | |
2480 | else { /* Needs to be taken off a list */ |
2481 | |
2482 | n = get_node(s, page_to_nid(page)); |
2483 | /* |
2484 | * Speculatively acquire the list_lock. |
2485 | * If the cmpxchg does not succeed then we may |
2486 | * drop the list_lock without any processing. |
2487 | * |
2488 | * Otherwise the list_lock will synchronize with |
2489 | * other processors updating the list of slabs. |
2490 | */ |
2491 | spin_lock_irqsave(&n->list_lock, flags); |
2492 | |
2493 | } |
2494 | } |
2495 | inuse = new.inuse; |
2496 | |
2497 | } while (!cmpxchg_double_slab(s, page, |
2498 | prior, counters, |
2499 | object, new.counters, |
2500 | "__slab_free")); |
2501 | |
2502 | if (likely(!n)) { |
2503 | |
2504 | /* |
2505 | * If we just froze the page then put it onto the |
2506 | * per cpu partial list. |
2507 | */ |
2508 | if (new.frozen && !was_frozen) { |
2509 | put_cpu_partial(s, page, 1); |
2510 | stat(s, CPU_PARTIAL_FREE); |
2511 | } |
2512 | /* |
2513 | * The list lock was not taken therefore no list |
2514 | * activity can be necessary. |
2515 | */ |
2516 | if (was_frozen) |
2517 | stat(s, FREE_FROZEN); |
2518 | return; |
2519 | } |
2520 | |
2521 | /* |
2522 | * was_frozen may have been set after we acquired the list_lock in |
2523 | * an earlier loop. So we need to check it here again. |
2524 | */ |
2525 | if (was_frozen) |
2526 | stat(s, FREE_FROZEN); |
2527 | else { |
2528 | if (unlikely(!inuse && n->nr_partial > s->min_partial)) |
2529 | goto slab_empty; |
2530 | |
2531 | /* |
2532 | * Objects left in the slab. If it was not on the partial list before |
2533 | * then add it. |
2534 | */ |
2535 | if (unlikely(!prior)) { |
2536 | remove_full(s, page); |
2537 | add_partial(n, page, DEACTIVATE_TO_TAIL); |
2538 | stat(s, FREE_ADD_PARTIAL); |
2539 | } |
2540 | } |
2541 | spin_unlock_irqrestore(&n->list_lock, flags); |
2542 | return; |
2543 | |
2544 | slab_empty: |
2545 | if (prior) { |
2546 | /* |
2547 | * Slab on the partial list. |
2548 | */ |
2549 | remove_partial(n, page); |
2550 | stat(s, FREE_REMOVE_PARTIAL); |
2551 | } else |
2552 | /* Slab must be on the full list */ |
2553 | remove_full(s, page); |
2554 | |
2555 | spin_unlock_irqrestore(&n->list_lock, flags); |
2556 | stat(s, FREE_SLAB); |
2557 | discard_slab(s, page); |
2558 | } |
2559 | |
2560 | /* |
2561 | * Fastpath with forced inlining to produce a kfree and kmem_cache_free that |
2562 | * can perform fastpath freeing without additional function calls. |
2563 | * |
2564 | * The fastpath is only possible if we are freeing to the current cpu slab |
2565 | * of this processor. This typically the case if we have just allocated |
2566 | * the item before. |
2567 | * |
2568 | * If fastpath is not possible then fall back to __slab_free where we deal |
2569 | * with all sorts of special processing. |
2570 | */ |
2571 | static __always_inline void slab_free(struct kmem_cache *s, |
2572 | struct page *page, void *x, unsigned long addr) |
2573 | { |
2574 | void **object = (void *)x; |
2575 | struct kmem_cache_cpu *c; |
2576 | unsigned long tid; |
2577 | |
2578 | slab_free_hook(s, x); |
2579 | |
2580 | redo: |
2581 | /* |
2582 | * Determine the currently cpus per cpu slab. |
2583 | * The cpu may change afterward. However that does not matter since |
2584 | * data is retrieved via this pointer. If we are on the same cpu |
2585 | * during the cmpxchg then the free will succedd. |
2586 | */ |
2587 | c = __this_cpu_ptr(s->cpu_slab); |
2588 | |
2589 | tid = c->tid; |
2590 | barrier(); |
2591 | |
2592 | if (likely(page == c->page)) { |
2593 | set_freepointer(s, object, c->freelist); |
2594 | |
2595 | if (unlikely(!this_cpu_cmpxchg_double( |
2596 | s->cpu_slab->freelist, s->cpu_slab->tid, |
2597 | c->freelist, tid, |
2598 | object, next_tid(tid)))) { |
2599 | |
2600 | note_cmpxchg_failure("slab_free", s, tid); |
2601 | goto redo; |
2602 | } |
2603 | stat(s, FREE_FASTPATH); |
2604 | } else |
2605 | __slab_free(s, page, x, addr); |
2606 | |
2607 | } |
2608 | |
2609 | void kmem_cache_free(struct kmem_cache *s, void *x) |
2610 | { |
2611 | struct page *page; |
2612 | |
2613 | page = virt_to_head_page(x); |
2614 | |
2615 | slab_free(s, page, x, _RET_IP_); |
2616 | |
2617 | trace_kmem_cache_free(_RET_IP_, x); |
2618 | } |
2619 | EXPORT_SYMBOL(kmem_cache_free); |
2620 | |
2621 | /* |
2622 | * Object placement in a slab is made very easy because we always start at |
2623 | * offset 0. If we tune the size of the object to the alignment then we can |
2624 | * get the required alignment by putting one properly sized object after |
2625 | * another. |
2626 | * |
2627 | * Notice that the allocation order determines the sizes of the per cpu |
2628 | * caches. Each processor has always one slab available for allocations. |
2629 | * Increasing the allocation order reduces the number of times that slabs |
2630 | * must be moved on and off the partial lists and is therefore a factor in |
2631 | * locking overhead. |
2632 | */ |
2633 | |
2634 | /* |
2635 | * Mininum / Maximum order of slab pages. This influences locking overhead |
2636 | * and slab fragmentation. A higher order reduces the number of partial slabs |
2637 | * and increases the number of allocations possible without having to |
2638 | * take the list_lock. |
2639 | */ |
2640 | static int slub_min_order; |
2641 | static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER; |
2642 | static int slub_min_objects; |
2643 | |
2644 | /* |
2645 | * Merge control. If this is set then no merging of slab caches will occur. |
2646 | * (Could be removed. This was introduced to pacify the merge skeptics.) |
2647 | */ |
2648 | static int slub_nomerge; |
2649 | |
2650 | /* |
2651 | * Calculate the order of allocation given an slab object size. |
2652 | * |
2653 | * The order of allocation has significant impact on performance and other |
2654 | * system components. Generally order 0 allocations should be preferred since |
2655 | * order 0 does not cause fragmentation in the page allocator. Larger objects |
2656 | * be problematic to put into order 0 slabs because there may be too much |
2657 | * unused space left. We go to a higher order if more than 1/16th of the slab |
2658 | * would be wasted. |
2659 | * |
2660 | * In order to reach satisfactory performance we must ensure that a minimum |
2661 | * number of objects is in one slab. Otherwise we may generate too much |
2662 | * activity on the partial lists which requires taking the list_lock. This is |
2663 | * less a concern for large slabs though which are rarely used. |
2664 | * |
2665 | * slub_max_order specifies the order where we begin to stop considering the |
2666 | * number of objects in a slab as critical. If we reach slub_max_order then |
2667 | * we try to keep the page order as low as possible. So we accept more waste |
2668 | * of space in favor of a small page order. |
2669 | * |
2670 | * Higher order allocations also allow the placement of more objects in a |
2671 | * slab and thereby reduce object handling overhead. If the user has |
2672 | * requested a higher mininum order then we start with that one instead of |
2673 | * the smallest order which will fit the object. |
2674 | */ |
2675 | static inline int slab_order(int size, int min_objects, |
2676 | int max_order, int fract_leftover, int reserved) |
2677 | { |
2678 | int order; |
2679 | int rem; |
2680 | int min_order = slub_min_order; |
2681 | |
2682 | if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE) |
2683 | return get_order(size * MAX_OBJS_PER_PAGE) - 1; |
2684 | |
2685 | for (order = max(min_order, |
2686 | fls(min_objects * size - 1) - PAGE_SHIFT); |
2687 | order <= max_order; order++) { |
2688 | |
2689 | unsigned long slab_size = PAGE_SIZE << order; |
2690 | |
2691 | if (slab_size < min_objects * size + reserved) |
2692 | continue; |
2693 | |
2694 | rem = (slab_size - reserved) % size; |
2695 | |
2696 | if (rem <= slab_size / fract_leftover) |
2697 | break; |
2698 | |
2699 | } |
2700 | |
2701 | return order; |
2702 | } |
2703 | |
2704 | static inline int calculate_order(int size, int reserved) |
2705 | { |
2706 | int order; |
2707 | int min_objects; |
2708 | int fraction; |
2709 | int max_objects; |
2710 | |
2711 | /* |
2712 | * Attempt to find best configuration for a slab. This |
2713 | * works by first attempting to generate a layout with |
2714 | * the best configuration and backing off gradually. |
2715 | * |
2716 | * First we reduce the acceptable waste in a slab. Then |
2717 | * we reduce the minimum objects required in a slab. |
2718 | */ |
2719 | min_objects = slub_min_objects; |
2720 | if (!min_objects) |
2721 | min_objects = 4 * (fls(nr_cpu_ids) + 1); |
2722 | max_objects = order_objects(slub_max_order, size, reserved); |
2723 | min_objects = min(min_objects, max_objects); |
2724 | |
2725 | while (min_objects > 1) { |
2726 | fraction = 16; |
2727 | while (fraction >= 4) { |
2728 | order = slab_order(size, min_objects, |
2729 | slub_max_order, fraction, reserved); |
2730 | if (order <= slub_max_order) |
2731 | return order; |
2732 | fraction /= 2; |
2733 | } |
2734 | min_objects--; |
2735 | } |
2736 | |
2737 | /* |
2738 | * We were unable to place multiple objects in a slab. Now |
2739 | * lets see if we can place a single object there. |
2740 | */ |
2741 | order = slab_order(size, 1, slub_max_order, 1, reserved); |
2742 | if (order <= slub_max_order) |
2743 | return order; |
2744 | |
2745 | /* |
2746 | * Doh this slab cannot be placed using slub_max_order. |
2747 | */ |
2748 | order = slab_order(size, 1, MAX_ORDER, 1, reserved); |
2749 | if (order < MAX_ORDER) |
2750 | return order; |
2751 | return -ENOSYS; |
2752 | } |
2753 | |
2754 | /* |
2755 | * Figure out what the alignment of the objects will be. |
2756 | */ |
2757 | static unsigned long calculate_alignment(unsigned long flags, |
2758 | unsigned long align, unsigned long size) |
2759 | { |
2760 | /* |
2761 | * If the user wants hardware cache aligned objects then follow that |
2762 | * suggestion if the object is sufficiently large. |
2763 | * |
2764 | * The hardware cache alignment cannot override the specified |
2765 | * alignment though. If that is greater then use it. |
2766 | */ |
2767 | if (flags & SLAB_HWCACHE_ALIGN) { |
2768 | unsigned long ralign = cache_line_size(); |
2769 | while (size <= ralign / 2) |
2770 | ralign /= 2; |
2771 | align = max(align, ralign); |
2772 | } |
2773 | |
2774 | if (align < ARCH_SLAB_MINALIGN) |
2775 | align = ARCH_SLAB_MINALIGN; |
2776 | |
2777 | return ALIGN(align, sizeof(void *)); |
2778 | } |
2779 | |
2780 | static void |
2781 | init_kmem_cache_node(struct kmem_cache_node *n) |
2782 | { |
2783 | n->nr_partial = 0; |
2784 | spin_lock_init(&n->list_lock); |
2785 | INIT_LIST_HEAD(&n->partial); |
2786 | #ifdef CONFIG_SLUB_DEBUG |
2787 | atomic_long_set(&n->nr_slabs, 0); |
2788 | atomic_long_set(&n->total_objects, 0); |
2789 | INIT_LIST_HEAD(&n->full); |
2790 | #endif |
2791 | } |
2792 | |
2793 | static inline int alloc_kmem_cache_cpus(struct kmem_cache *s) |
2794 | { |
2795 | BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE < |
2796 | SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu)); |
2797 | |
2798 | /* |
2799 | * Must align to double word boundary for the double cmpxchg |
2800 | * instructions to work; see __pcpu_double_call_return_bool(). |
2801 | */ |
2802 | s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu), |
2803 | 2 * sizeof(void *)); |
2804 | |
2805 | if (!s->cpu_slab) |
2806 | return 0; |
2807 | |
2808 | init_kmem_cache_cpus(s); |
2809 | |
2810 | return 1; |
2811 | } |
2812 | |
2813 | static struct kmem_cache *kmem_cache_node; |
2814 | |
2815 | /* |
2816 | * No kmalloc_node yet so do it by hand. We know that this is the first |
2817 | * slab on the node for this slabcache. There are no concurrent accesses |
2818 | * possible. |
2819 | * |
2820 | * Note that this function only works on the kmalloc_node_cache |
2821 | * when allocating for the kmalloc_node_cache. This is used for bootstrapping |
2822 | * memory on a fresh node that has no slab structures yet. |
2823 | */ |
2824 | static void early_kmem_cache_node_alloc(int node) |
2825 | { |
2826 | struct page *page; |
2827 | struct kmem_cache_node *n; |
2828 | |
2829 | BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node)); |
2830 | |
2831 | page = new_slab(kmem_cache_node, GFP_NOWAIT, node); |
2832 | |
2833 | BUG_ON(!page); |
2834 | if (page_to_nid(page) != node) { |
2835 | printk(KERN_ERR "SLUB: Unable to allocate memory from " |
2836 | "node %d\n", node); |
2837 | printk(KERN_ERR "SLUB: Allocating a useless per node structure " |
2838 | "in order to be able to continue\n"); |
2839 | } |
2840 | |
2841 | n = page->freelist; |
2842 | BUG_ON(!n); |
2843 | page->freelist = get_freepointer(kmem_cache_node, n); |
2844 | page->inuse = 1; |
2845 | page->frozen = 0; |
2846 | kmem_cache_node->node[node] = n; |
2847 | #ifdef CONFIG_SLUB_DEBUG |
2848 | init_object(kmem_cache_node, n, SLUB_RED_ACTIVE); |
2849 | init_tracking(kmem_cache_node, n); |
2850 | #endif |
2851 | init_kmem_cache_node(n); |
2852 | inc_slabs_node(kmem_cache_node, node, page->objects); |
2853 | |
2854 | add_partial(n, page, DEACTIVATE_TO_HEAD); |
2855 | } |
2856 | |
2857 | static void free_kmem_cache_nodes(struct kmem_cache *s) |
2858 | { |
2859 | int node; |
2860 | |
2861 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2862 | struct kmem_cache_node *n = s->node[node]; |
2863 | |
2864 | if (n) |
2865 | kmem_cache_free(kmem_cache_node, n); |
2866 | |
2867 | s->node[node] = NULL; |
2868 | } |
2869 | } |
2870 | |
2871 | static int init_kmem_cache_nodes(struct kmem_cache *s) |
2872 | { |
2873 | int node; |
2874 | |
2875 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2876 | struct kmem_cache_node *n; |
2877 | |
2878 | if (slab_state == DOWN) { |
2879 | early_kmem_cache_node_alloc(node); |
2880 | continue; |
2881 | } |
2882 | n = kmem_cache_alloc_node(kmem_cache_node, |
2883 | GFP_KERNEL, node); |
2884 | |
2885 | if (!n) { |
2886 | free_kmem_cache_nodes(s); |
2887 | return 0; |
2888 | } |
2889 | |
2890 | s->node[node] = n; |
2891 | init_kmem_cache_node(n); |
2892 | } |
2893 | return 1; |
2894 | } |
2895 | |
2896 | static void set_min_partial(struct kmem_cache *s, unsigned long min) |
2897 | { |
2898 | if (min < MIN_PARTIAL) |
2899 | min = MIN_PARTIAL; |
2900 | else if (min > MAX_PARTIAL) |
2901 | min = MAX_PARTIAL; |
2902 | s->min_partial = min; |
2903 | } |
2904 | |
2905 | /* |
2906 | * calculate_sizes() determines the order and the distribution of data within |
2907 | * a slab object. |
2908 | */ |
2909 | static int calculate_sizes(struct kmem_cache *s, int forced_order) |
2910 | { |
2911 | unsigned long flags = s->flags; |
2912 | unsigned long size = s->object_size; |
2913 | unsigned long align = s->align; |
2914 | int order; |
2915 | |
2916 | /* |
2917 | * Round up object size to the next word boundary. We can only |
2918 | * place the free pointer at word boundaries and this determines |
2919 | * the possible location of the free pointer. |
2920 | */ |
2921 | size = ALIGN(size, sizeof(void *)); |
2922 | |
2923 | #ifdef CONFIG_SLUB_DEBUG |
2924 | /* |
2925 | * Determine if we can poison the object itself. If the user of |
2926 | * the slab may touch the object after free or before allocation |
2927 | * then we should never poison the object itself. |
2928 | */ |
2929 | if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) && |
2930 | !s->ctor) |
2931 | s->flags |= __OBJECT_POISON; |
2932 | else |
2933 | s->flags &= ~__OBJECT_POISON; |
2934 | |
2935 | |
2936 | /* |
2937 | * If we are Redzoning then check if there is some space between the |
2938 | * end of the object and the free pointer. If not then add an |
2939 | * additional word to have some bytes to store Redzone information. |
2940 | */ |
2941 | if ((flags & SLAB_RED_ZONE) && size == s->object_size) |
2942 | size += sizeof(void *); |
2943 | #endif |
2944 | |
2945 | /* |
2946 | * With that we have determined the number of bytes in actual use |
2947 | * by the object. This is the potential offset to the free pointer. |
2948 | */ |
2949 | s->inuse = size; |
2950 | |
2951 | if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || |
2952 | s->ctor)) { |
2953 | /* |
2954 | * Relocate free pointer after the object if it is not |
2955 | * permitted to overwrite the first word of the object on |
2956 | * kmem_cache_free. |
2957 | * |
2958 | * This is the case if we do RCU, have a constructor or |
2959 | * destructor or are poisoning the objects. |
2960 | */ |
2961 | s->offset = size; |
2962 | size += sizeof(void *); |
2963 | } |
2964 | |
2965 | #ifdef CONFIG_SLUB_DEBUG |
2966 | if (flags & SLAB_STORE_USER) |
2967 | /* |
2968 | * Need to store information about allocs and frees after |
2969 | * the object. |
2970 | */ |
2971 | size += 2 * sizeof(struct track); |
2972 | |
2973 | if (flags & SLAB_RED_ZONE) |
2974 | /* |
2975 | * Add some empty padding so that we can catch |
2976 | * overwrites from earlier objects rather than let |
2977 | * tracking information or the free pointer be |
2978 | * corrupted if a user writes before the start |
2979 | * of the object. |
2980 | */ |
2981 | size += sizeof(void *); |
2982 | #endif |
2983 | |
2984 | /* |
2985 | * Determine the alignment based on various parameters that the |
2986 | * user specified and the dynamic determination of cache line size |
2987 | * on bootup. |
2988 | */ |
2989 | align = calculate_alignment(flags, align, s->object_size); |
2990 | s->align = align; |
2991 | |
2992 | /* |
2993 | * SLUB stores one object immediately after another beginning from |
2994 | * offset 0. In order to align the objects we have to simply size |
2995 | * each object to conform to the alignment. |
2996 | */ |
2997 | size = ALIGN(size, align); |
2998 | s->size = size; |
2999 | if (forced_order >= 0) |
3000 | order = forced_order; |
3001 | else |
3002 | order = calculate_order(size, s->reserved); |
3003 | |
3004 | if (order < 0) |
3005 | return 0; |
3006 | |
3007 | s->allocflags = 0; |
3008 | if (order) |
3009 | s->allocflags |= __GFP_COMP; |
3010 | |
3011 | if (s->flags & SLAB_CACHE_DMA) |
3012 | s->allocflags |= SLUB_DMA; |
3013 | |
3014 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
3015 | s->allocflags |= __GFP_RECLAIMABLE; |
3016 | |
3017 | /* |
3018 | * Determine the number of objects per slab |
3019 | */ |
3020 | s->oo = oo_make(order, size, s->reserved); |
3021 | s->min = oo_make(get_order(size), size, s->reserved); |
3022 | if (oo_objects(s->oo) > oo_objects(s->max)) |
3023 | s->max = s->oo; |
3024 | |
3025 | return !!oo_objects(s->oo); |
3026 | |
3027 | } |
3028 | |
3029 | static int kmem_cache_open(struct kmem_cache *s, |
3030 | const char *name, size_t size, |
3031 | size_t align, unsigned long flags, |
3032 | void (*ctor)(void *)) |
3033 | { |
3034 | memset(s, 0, kmem_size); |
3035 | s->name = name; |
3036 | s->ctor = ctor; |
3037 | s->object_size = size; |
3038 | s->align = align; |
3039 | s->flags = kmem_cache_flags(size, flags, name, ctor); |
3040 | s->reserved = 0; |
3041 | |
3042 | if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU)) |
3043 | s->reserved = sizeof(struct rcu_head); |
3044 | |
3045 | if (!calculate_sizes(s, -1)) |
3046 | goto error; |
3047 | if (disable_higher_order_debug) { |
3048 | /* |
3049 | * Disable debugging flags that store metadata if the min slab |
3050 | * order increased. |
3051 | */ |
3052 | if (get_order(s->size) > get_order(s->object_size)) { |
3053 | s->flags &= ~DEBUG_METADATA_FLAGS; |
3054 | s->offset = 0; |
3055 | if (!calculate_sizes(s, -1)) |
3056 | goto error; |
3057 | } |
3058 | } |
3059 | |
3060 | #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ |
3061 | defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) |
3062 | if (system_has_cmpxchg_double() && (s->flags & SLAB_DEBUG_FLAGS) == 0) |
3063 | /* Enable fast mode */ |
3064 | s->flags |= __CMPXCHG_DOUBLE; |
3065 | #endif |
3066 | |
3067 | /* |
3068 | * The larger the object size is, the more pages we want on the partial |
3069 | * list to avoid pounding the page allocator excessively. |
3070 | */ |
3071 | set_min_partial(s, ilog2(s->size) / 2); |
3072 | |
3073 | /* |
3074 | * cpu_partial determined the maximum number of objects kept in the |
3075 | * per cpu partial lists of a processor. |
3076 | * |
3077 | * Per cpu partial lists mainly contain slabs that just have one |
3078 | * object freed. If they are used for allocation then they can be |
3079 | * filled up again with minimal effort. The slab will never hit the |
3080 | * per node partial lists and therefore no locking will be required. |
3081 | * |
3082 | * This setting also determines |
3083 | * |
3084 | * A) The number of objects from per cpu partial slabs dumped to the |
3085 | * per node list when we reach the limit. |
3086 | * B) The number of objects in cpu partial slabs to extract from the |
3087 | * per node list when we run out of per cpu objects. We only fetch 50% |
3088 | * to keep some capacity around for frees. |
3089 | */ |
3090 | if (kmem_cache_debug(s)) |
3091 | s->cpu_partial = 0; |
3092 | else if (s->size >= PAGE_SIZE) |
3093 | s->cpu_partial = 2; |
3094 | else if (s->size >= 1024) |
3095 | s->cpu_partial = 6; |
3096 | else if (s->size >= 256) |
3097 | s->cpu_partial = 13; |
3098 | else |
3099 | s->cpu_partial = 30; |
3100 | |
3101 | s->refcount = 1; |
3102 | #ifdef CONFIG_NUMA |
3103 | s->remote_node_defrag_ratio = 1000; |
3104 | #endif |
3105 | if (!init_kmem_cache_nodes(s)) |
3106 | goto error; |
3107 | |
3108 | if (alloc_kmem_cache_cpus(s)) |
3109 | return 1; |
3110 | |
3111 | free_kmem_cache_nodes(s); |
3112 | error: |
3113 | if (flags & SLAB_PANIC) |
3114 | panic("Cannot create slab %s size=%lu realsize=%u " |
3115 | "order=%u offset=%u flags=%lx\n", |
3116 | s->name, (unsigned long)size, s->size, oo_order(s->oo), |
3117 | s->offset, flags); |
3118 | return 0; |
3119 | } |
3120 | |
3121 | /* |
3122 | * Determine the size of a slab object |
3123 | */ |
3124 | unsigned int kmem_cache_size(struct kmem_cache *s) |
3125 | { |
3126 | return s->object_size; |
3127 | } |
3128 | EXPORT_SYMBOL(kmem_cache_size); |
3129 | |
3130 | static void list_slab_objects(struct kmem_cache *s, struct page *page, |
3131 | const char *text) |
3132 | { |
3133 | #ifdef CONFIG_SLUB_DEBUG |
3134 | void *addr = page_address(page); |
3135 | void *p; |
3136 | unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) * |
3137 | sizeof(long), GFP_ATOMIC); |
3138 | if (!map) |
3139 | return; |
3140 | slab_err(s, page, "%s", text); |
3141 | slab_lock(page); |
3142 | |
3143 | get_map(s, page, map); |
3144 | for_each_object(p, s, addr, page->objects) { |
3145 | |
3146 | if (!test_bit(slab_index(p, s, addr), map)) { |
3147 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n", |
3148 | p, p - addr); |
3149 | print_tracking(s, p); |
3150 | } |
3151 | } |
3152 | slab_unlock(page); |
3153 | kfree(map); |
3154 | #endif |
3155 | } |
3156 | |
3157 | /* |
3158 | * Attempt to free all partial slabs on a node. |
3159 | * This is called from kmem_cache_close(). We must be the last thread |
3160 | * using the cache and therefore we do not need to lock anymore. |
3161 | */ |
3162 | static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) |
3163 | { |
3164 | struct page *page, *h; |
3165 | |
3166 | list_for_each_entry_safe(page, h, &n->partial, lru) { |
3167 | if (!page->inuse) { |
3168 | remove_partial(n, page); |
3169 | discard_slab(s, page); |
3170 | } else { |
3171 | list_slab_objects(s, page, |
3172 | "Objects remaining on kmem_cache_close()"); |
3173 | } |
3174 | } |
3175 | } |
3176 | |
3177 | /* |
3178 | * Release all resources used by a slab cache. |
3179 | */ |
3180 | static inline int kmem_cache_close(struct kmem_cache *s) |
3181 | { |
3182 | int node; |
3183 | |
3184 | flush_all(s); |
3185 | free_percpu(s->cpu_slab); |
3186 | /* Attempt to free all objects */ |
3187 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3188 | struct kmem_cache_node *n = get_node(s, node); |
3189 | |
3190 | free_partial(s, n); |
3191 | if (n->nr_partial || slabs_node(s, node)) |
3192 | return 1; |
3193 | } |
3194 | free_kmem_cache_nodes(s); |
3195 | return 0; |
3196 | } |
3197 | |
3198 | /* |
3199 | * Close a cache and release the kmem_cache structure |
3200 | * (must be used for caches created using kmem_cache_create) |
3201 | */ |
3202 | void kmem_cache_destroy(struct kmem_cache *s) |
3203 | { |
3204 | mutex_lock(&slab_mutex); |
3205 | s->refcount--; |
3206 | if (!s->refcount) { |
3207 | list_del(&s->list); |
3208 | mutex_unlock(&slab_mutex); |
3209 | if (kmem_cache_close(s)) { |
3210 | printk(KERN_ERR "SLUB %s: %s called for cache that " |
3211 | "still has objects.\n", s->name, __func__); |
3212 | dump_stack(); |
3213 | } |
3214 | if (s->flags & SLAB_DESTROY_BY_RCU) |
3215 | rcu_barrier(); |
3216 | sysfs_slab_remove(s); |
3217 | } else |
3218 | mutex_unlock(&slab_mutex); |
3219 | } |
3220 | EXPORT_SYMBOL(kmem_cache_destroy); |
3221 | |
3222 | /******************************************************************** |
3223 | * Kmalloc subsystem |
3224 | *******************************************************************/ |
3225 | |
3226 | struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT]; |
3227 | EXPORT_SYMBOL(kmalloc_caches); |
3228 | |
3229 | static struct kmem_cache *kmem_cache; |
3230 | |
3231 | #ifdef CONFIG_ZONE_DMA |
3232 | static struct kmem_cache *kmalloc_dma_caches[SLUB_PAGE_SHIFT]; |
3233 | #endif |
3234 | |
3235 | static int __init setup_slub_min_order(char *str) |
3236 | { |
3237 | get_option(&str, &slub_min_order); |
3238 | |
3239 | return 1; |
3240 | } |
3241 | |
3242 | __setup("slub_min_order=", setup_slub_min_order); |
3243 | |
3244 | static int __init setup_slub_max_order(char *str) |
3245 | { |
3246 | get_option(&str, &slub_max_order); |
3247 | slub_max_order = min(slub_max_order, MAX_ORDER - 1); |
3248 | |
3249 | return 1; |
3250 | } |
3251 | |
3252 | __setup("slub_max_order=", setup_slub_max_order); |
3253 | |
3254 | static int __init setup_slub_min_objects(char *str) |
3255 | { |
3256 | get_option(&str, &slub_min_objects); |
3257 | |
3258 | return 1; |
3259 | } |
3260 | |
3261 | __setup("slub_min_objects=", setup_slub_min_objects); |
3262 | |
3263 | static int __init setup_slub_nomerge(char *str) |
3264 | { |
3265 | slub_nomerge = 1; |
3266 | return 1; |
3267 | } |
3268 | |
3269 | __setup("slub_nomerge", setup_slub_nomerge); |
3270 | |
3271 | static struct kmem_cache *__init create_kmalloc_cache(const char *name, |
3272 | int size, unsigned int flags) |
3273 | { |
3274 | struct kmem_cache *s; |
3275 | |
3276 | s = kmem_cache_alloc(kmem_cache, GFP_NOWAIT); |
3277 | |
3278 | /* |
3279 | * This function is called with IRQs disabled during early-boot on |
3280 | * single CPU so there's no need to take slab_mutex here. |
3281 | */ |
3282 | if (!kmem_cache_open(s, name, size, ARCH_KMALLOC_MINALIGN, |
3283 | flags, NULL)) |
3284 | goto panic; |
3285 | |
3286 | list_add(&s->list, &slab_caches); |
3287 | return s; |
3288 | |
3289 | panic: |
3290 | panic("Creation of kmalloc slab %s size=%d failed.\n", name, size); |
3291 | return NULL; |
3292 | } |
3293 | |
3294 | /* |
3295 | * Conversion table for small slabs sizes / 8 to the index in the |
3296 | * kmalloc array. This is necessary for slabs < 192 since we have non power |
3297 | * of two cache sizes there. The size of larger slabs can be determined using |
3298 | * fls. |
3299 | */ |
3300 | static s8 size_index[24] = { |
3301 | 3, /* 8 */ |
3302 | 4, /* 16 */ |
3303 | 5, /* 24 */ |
3304 | 5, /* 32 */ |
3305 | 6, /* 40 */ |
3306 | 6, /* 48 */ |
3307 | 6, /* 56 */ |
3308 | 6, /* 64 */ |
3309 | 1, /* 72 */ |
3310 | 1, /* 80 */ |
3311 | 1, /* 88 */ |
3312 | 1, /* 96 */ |
3313 | 7, /* 104 */ |
3314 | 7, /* 112 */ |
3315 | 7, /* 120 */ |
3316 | 7, /* 128 */ |
3317 | 2, /* 136 */ |
3318 | 2, /* 144 */ |
3319 | 2, /* 152 */ |
3320 | 2, /* 160 */ |
3321 | 2, /* 168 */ |
3322 | 2, /* 176 */ |
3323 | 2, /* 184 */ |
3324 | 2 /* 192 */ |
3325 | }; |
3326 | |
3327 | static inline int size_index_elem(size_t bytes) |
3328 | { |
3329 | return (bytes - 1) / 8; |
3330 | } |
3331 | |
3332 | static struct kmem_cache *get_slab(size_t size, gfp_t flags) |
3333 | { |
3334 | int index; |
3335 | |
3336 | if (size <= 192) { |
3337 | if (!size) |
3338 | return ZERO_SIZE_PTR; |
3339 | |
3340 | index = size_index[size_index_elem(size)]; |
3341 | } else |
3342 | index = fls(size - 1); |
3343 | |
3344 | #ifdef CONFIG_ZONE_DMA |
3345 | if (unlikely((flags & SLUB_DMA))) |
3346 | return kmalloc_dma_caches[index]; |
3347 | |
3348 | #endif |
3349 | return kmalloc_caches[index]; |
3350 | } |
3351 | |
3352 | void *__kmalloc(size_t size, gfp_t flags) |
3353 | { |
3354 | struct kmem_cache *s; |
3355 | void *ret; |
3356 | |
3357 | if (unlikely(size > SLUB_MAX_SIZE)) |
3358 | return kmalloc_large(size, flags); |
3359 | |
3360 | s = get_slab(size, flags); |
3361 | |
3362 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3363 | return s; |
3364 | |
3365 | ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_); |
3366 | |
3367 | trace_kmalloc(_RET_IP_, ret, size, s->size, flags); |
3368 | |
3369 | return ret; |
3370 | } |
3371 | EXPORT_SYMBOL(__kmalloc); |
3372 | |
3373 | #ifdef CONFIG_NUMA |
3374 | static void *kmalloc_large_node(size_t size, gfp_t flags, int node) |
3375 | { |
3376 | struct page *page; |
3377 | void *ptr = NULL; |
3378 | |
3379 | flags |= __GFP_COMP | __GFP_NOTRACK; |
3380 | page = alloc_pages_node(node, flags, get_order(size)); |
3381 | if (page) |
3382 | ptr = page_address(page); |
3383 | |
3384 | kmemleak_alloc(ptr, size, 1, flags); |
3385 | return ptr; |
3386 | } |
3387 | |
3388 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3389 | { |
3390 | struct kmem_cache *s; |
3391 | void *ret; |
3392 | |
3393 | if (unlikely(size > SLUB_MAX_SIZE)) { |
3394 | ret = kmalloc_large_node(size, flags, node); |
3395 | |
3396 | trace_kmalloc_node(_RET_IP_, ret, |
3397 | size, PAGE_SIZE << get_order(size), |
3398 | flags, node); |
3399 | |
3400 | return ret; |
3401 | } |
3402 | |
3403 | s = get_slab(size, flags); |
3404 | |
3405 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3406 | return s; |
3407 | |
3408 | ret = slab_alloc(s, flags, node, _RET_IP_); |
3409 | |
3410 | trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node); |
3411 | |
3412 | return ret; |
3413 | } |
3414 | EXPORT_SYMBOL(__kmalloc_node); |
3415 | #endif |
3416 | |
3417 | size_t ksize(const void *object) |
3418 | { |
3419 | struct page *page; |
3420 | |
3421 | if (unlikely(object == ZERO_SIZE_PTR)) |
3422 | return 0; |
3423 | |
3424 | page = virt_to_head_page(object); |
3425 | |
3426 | if (unlikely(!PageSlab(page))) { |
3427 | WARN_ON(!PageCompound(page)); |
3428 | return PAGE_SIZE << compound_order(page); |
3429 | } |
3430 | |
3431 | return slab_ksize(page->slab); |
3432 | } |
3433 | EXPORT_SYMBOL(ksize); |
3434 | |
3435 | #ifdef CONFIG_SLUB_DEBUG |
3436 | bool verify_mem_not_deleted(const void *x) |
3437 | { |
3438 | struct page *page; |
3439 | void *object = (void *)x; |
3440 | unsigned long flags; |
3441 | bool rv; |
3442 | |
3443 | if (unlikely(ZERO_OR_NULL_PTR(x))) |
3444 | return false; |
3445 | |
3446 | local_irq_save(flags); |
3447 | |
3448 | page = virt_to_head_page(x); |
3449 | if (unlikely(!PageSlab(page))) { |
3450 | /* maybe it was from stack? */ |
3451 | rv = true; |
3452 | goto out_unlock; |
3453 | } |
3454 | |
3455 | slab_lock(page); |
3456 | if (on_freelist(page->slab, page, object)) { |
3457 | object_err(page->slab, page, object, "Object is on free-list"); |
3458 | rv = false; |
3459 | } else { |
3460 | rv = true; |
3461 | } |
3462 | slab_unlock(page); |
3463 | |
3464 | out_unlock: |
3465 | local_irq_restore(flags); |
3466 | return rv; |
3467 | } |
3468 | EXPORT_SYMBOL(verify_mem_not_deleted); |
3469 | #endif |
3470 | |
3471 | void kfree(const void *x) |
3472 | { |
3473 | struct page *page; |
3474 | void *object = (void *)x; |
3475 | |
3476 | trace_kfree(_RET_IP_, x); |
3477 | |
3478 | if (unlikely(ZERO_OR_NULL_PTR(x))) |
3479 | return; |
3480 | |
3481 | page = virt_to_head_page(x); |
3482 | if (unlikely(!PageSlab(page))) { |
3483 | BUG_ON(!PageCompound(page)); |
3484 | kmemleak_free(x); |
3485 | put_page(page); |
3486 | return; |
3487 | } |
3488 | slab_free(page->slab, page, object, _RET_IP_); |
3489 | } |
3490 | EXPORT_SYMBOL(kfree); |
3491 | |
3492 | /* |
3493 | * kmem_cache_shrink removes empty slabs from the partial lists and sorts |
3494 | * the remaining slabs by the number of items in use. The slabs with the |
3495 | * most items in use come first. New allocations will then fill those up |
3496 | * and thus they can be removed from the partial lists. |
3497 | * |
3498 | * The slabs with the least items are placed last. This results in them |
3499 | * being allocated from last increasing the chance that the last objects |
3500 | * are freed in them. |
3501 | */ |
3502 | int kmem_cache_shrink(struct kmem_cache *s) |
3503 | { |
3504 | int node; |
3505 | int i; |
3506 | struct kmem_cache_node *n; |
3507 | struct page *page; |
3508 | struct page *t; |
3509 | int objects = oo_objects(s->max); |
3510 | struct list_head *slabs_by_inuse = |
3511 | kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL); |
3512 | unsigned long flags; |
3513 | |
3514 | if (!slabs_by_inuse) |
3515 | return -ENOMEM; |
3516 | |
3517 | flush_all(s); |
3518 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3519 | n = get_node(s, node); |
3520 | |
3521 | if (!n->nr_partial) |
3522 | continue; |
3523 | |
3524 | for (i = 0; i < objects; i++) |
3525 | INIT_LIST_HEAD(slabs_by_inuse + i); |
3526 | |
3527 | spin_lock_irqsave(&n->list_lock, flags); |
3528 | |
3529 | /* |
3530 | * Build lists indexed by the items in use in each slab. |
3531 | * |
3532 | * Note that concurrent frees may occur while we hold the |
3533 | * list_lock. page->inuse here is the upper limit. |
3534 | */ |
3535 | list_for_each_entry_safe(page, t, &n->partial, lru) { |
3536 | list_move(&page->lru, slabs_by_inuse + page->inuse); |
3537 | if (!page->inuse) |
3538 | n->nr_partial--; |
3539 | } |
3540 | |
3541 | /* |
3542 | * Rebuild the partial list with the slabs filled up most |
3543 | * first and the least used slabs at the end. |
3544 | */ |
3545 | for (i = objects - 1; i > 0; i--) |
3546 | list_splice(slabs_by_inuse + i, n->partial.prev); |
3547 | |
3548 | spin_unlock_irqrestore(&n->list_lock, flags); |
3549 | |
3550 | /* Release empty slabs */ |
3551 | list_for_each_entry_safe(page, t, slabs_by_inuse, lru) |
3552 | discard_slab(s, page); |
3553 | } |
3554 | |
3555 | kfree(slabs_by_inuse); |
3556 | return 0; |
3557 | } |
3558 | EXPORT_SYMBOL(kmem_cache_shrink); |
3559 | |
3560 | #if defined(CONFIG_MEMORY_HOTPLUG) |
3561 | static int slab_mem_going_offline_callback(void *arg) |
3562 | { |
3563 | struct kmem_cache *s; |
3564 | |
3565 | mutex_lock(&slab_mutex); |
3566 | list_for_each_entry(s, &slab_caches, list) |
3567 | kmem_cache_shrink(s); |
3568 | mutex_unlock(&slab_mutex); |
3569 | |
3570 | return 0; |
3571 | } |
3572 | |
3573 | static void slab_mem_offline_callback(void *arg) |
3574 | { |
3575 | struct kmem_cache_node *n; |
3576 | struct kmem_cache *s; |
3577 | struct memory_notify *marg = arg; |
3578 | int offline_node; |
3579 | |
3580 | offline_node = marg->status_change_nid; |
3581 | |
3582 | /* |
3583 | * If the node still has available memory. we need kmem_cache_node |
3584 | * for it yet. |
3585 | */ |
3586 | if (offline_node < 0) |
3587 | return; |
3588 | |
3589 | mutex_lock(&slab_mutex); |
3590 | list_for_each_entry(s, &slab_caches, list) { |
3591 | n = get_node(s, offline_node); |
3592 | if (n) { |
3593 | /* |
3594 | * if n->nr_slabs > 0, slabs still exist on the node |
3595 | * that is going down. We were unable to free them, |
3596 | * and offline_pages() function shouldn't call this |
3597 | * callback. So, we must fail. |
3598 | */ |
3599 | BUG_ON(slabs_node(s, offline_node)); |
3600 | |
3601 | s->node[offline_node] = NULL; |
3602 | kmem_cache_free(kmem_cache_node, n); |
3603 | } |
3604 | } |
3605 | mutex_unlock(&slab_mutex); |
3606 | } |
3607 | |
3608 | static int slab_mem_going_online_callback(void *arg) |
3609 | { |
3610 | struct kmem_cache_node *n; |
3611 | struct kmem_cache *s; |
3612 | struct memory_notify *marg = arg; |
3613 | int nid = marg->status_change_nid; |
3614 | int ret = 0; |
3615 | |
3616 | /* |
3617 | * If the node's memory is already available, then kmem_cache_node is |
3618 | * already created. Nothing to do. |
3619 | */ |
3620 | if (nid < 0) |
3621 | return 0; |
3622 | |
3623 | /* |
3624 | * We are bringing a node online. No memory is available yet. We must |
3625 | * allocate a kmem_cache_node structure in order to bring the node |
3626 | * online. |
3627 | */ |
3628 | mutex_lock(&slab_mutex); |
3629 | list_for_each_entry(s, &slab_caches, list) { |
3630 | /* |
3631 | * XXX: kmem_cache_alloc_node will fallback to other nodes |
3632 | * since memory is not yet available from the node that |
3633 | * is brought up. |
3634 | */ |
3635 | n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL); |
3636 | if (!n) { |
3637 | ret = -ENOMEM; |
3638 | goto out; |
3639 | } |
3640 | init_kmem_cache_node(n); |
3641 | s->node[nid] = n; |
3642 | } |
3643 | out: |
3644 | mutex_unlock(&slab_mutex); |
3645 | return ret; |
3646 | } |
3647 | |
3648 | static int slab_memory_callback(struct notifier_block *self, |
3649 | unsigned long action, void *arg) |
3650 | { |
3651 | int ret = 0; |
3652 | |
3653 | switch (action) { |
3654 | case MEM_GOING_ONLINE: |
3655 | ret = slab_mem_going_online_callback(arg); |
3656 | break; |
3657 | case MEM_GOING_OFFLINE: |
3658 | ret = slab_mem_going_offline_callback(arg); |
3659 | break; |
3660 | case MEM_OFFLINE: |
3661 | case MEM_CANCEL_ONLINE: |
3662 | slab_mem_offline_callback(arg); |
3663 | break; |
3664 | case MEM_ONLINE: |
3665 | case MEM_CANCEL_OFFLINE: |
3666 | break; |
3667 | } |
3668 | if (ret) |
3669 | ret = notifier_from_errno(ret); |
3670 | else |
3671 | ret = NOTIFY_OK; |
3672 | return ret; |
3673 | } |
3674 | |
3675 | #endif /* CONFIG_MEMORY_HOTPLUG */ |
3676 | |
3677 | /******************************************************************** |
3678 | * Basic setup of slabs |
3679 | *******************************************************************/ |
3680 | |
3681 | /* |
3682 | * Used for early kmem_cache structures that were allocated using |
3683 | * the page allocator |
3684 | */ |
3685 | |
3686 | static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s) |
3687 | { |
3688 | int node; |
3689 | |
3690 | list_add(&s->list, &slab_caches); |
3691 | s->refcount = -1; |
3692 | |
3693 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3694 | struct kmem_cache_node *n = get_node(s, node); |
3695 | struct page *p; |
3696 | |
3697 | if (n) { |
3698 | list_for_each_entry(p, &n->partial, lru) |
3699 | p->slab = s; |
3700 | |
3701 | #ifdef CONFIG_SLUB_DEBUG |
3702 | list_for_each_entry(p, &n->full, lru) |
3703 | p->slab = s; |
3704 | #endif |
3705 | } |
3706 | } |
3707 | } |
3708 | |
3709 | void __init kmem_cache_init(void) |
3710 | { |
3711 | int i; |
3712 | int caches = 0; |
3713 | struct kmem_cache *temp_kmem_cache; |
3714 | int order; |
3715 | struct kmem_cache *temp_kmem_cache_node; |
3716 | unsigned long kmalloc_size; |
3717 | |
3718 | if (debug_guardpage_minorder()) |
3719 | slub_max_order = 0; |
3720 | |
3721 | kmem_size = offsetof(struct kmem_cache, node) + |
3722 | nr_node_ids * sizeof(struct kmem_cache_node *); |
3723 | |
3724 | /* Allocate two kmem_caches from the page allocator */ |
3725 | kmalloc_size = ALIGN(kmem_size, cache_line_size()); |
3726 | order = get_order(2 * kmalloc_size); |
3727 | kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order); |
3728 | |
3729 | /* |
3730 | * Must first have the slab cache available for the allocations of the |
3731 | * struct kmem_cache_node's. There is special bootstrap code in |
3732 | * kmem_cache_open for slab_state == DOWN. |
3733 | */ |
3734 | kmem_cache_node = (void *)kmem_cache + kmalloc_size; |
3735 | |
3736 | kmem_cache_open(kmem_cache_node, "kmem_cache_node", |
3737 | sizeof(struct kmem_cache_node), |
3738 | 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
3739 | |
3740 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
3741 | |
3742 | /* Able to allocate the per node structures */ |
3743 | slab_state = PARTIAL; |
3744 | |
3745 | temp_kmem_cache = kmem_cache; |
3746 | kmem_cache_open(kmem_cache, "kmem_cache", kmem_size, |
3747 | 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); |
3748 | kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT); |
3749 | memcpy(kmem_cache, temp_kmem_cache, kmem_size); |
3750 | |
3751 | /* |
3752 | * Allocate kmem_cache_node properly from the kmem_cache slab. |
3753 | * kmem_cache_node is separately allocated so no need to |
3754 | * update any list pointers. |
3755 | */ |
3756 | temp_kmem_cache_node = kmem_cache_node; |
3757 | |
3758 | kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT); |
3759 | memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size); |
3760 | |
3761 | kmem_cache_bootstrap_fixup(kmem_cache_node); |
3762 | |
3763 | caches++; |
3764 | kmem_cache_bootstrap_fixup(kmem_cache); |
3765 | caches++; |
3766 | /* Free temporary boot structure */ |
3767 | free_pages((unsigned long)temp_kmem_cache, order); |
3768 | |
3769 | /* Now we can use the kmem_cache to allocate kmalloc slabs */ |
3770 | |
3771 | /* |
3772 | * Patch up the size_index table if we have strange large alignment |
3773 | * requirements for the kmalloc array. This is only the case for |
3774 | * MIPS it seems. The standard arches will not generate any code here. |
3775 | * |
3776 | * Largest permitted alignment is 256 bytes due to the way we |
3777 | * handle the index determination for the smaller caches. |
3778 | * |
3779 | * Make sure that nothing crazy happens if someone starts tinkering |
3780 | * around with ARCH_KMALLOC_MINALIGN |
3781 | */ |
3782 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || |
3783 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); |
3784 | |
3785 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { |
3786 | int elem = size_index_elem(i); |
3787 | if (elem >= ARRAY_SIZE(size_index)) |
3788 | break; |
3789 | size_index[elem] = KMALLOC_SHIFT_LOW; |
3790 | } |
3791 | |
3792 | if (KMALLOC_MIN_SIZE == 64) { |
3793 | /* |
3794 | * The 96 byte size cache is not used if the alignment |
3795 | * is 64 byte. |
3796 | */ |
3797 | for (i = 64 + 8; i <= 96; i += 8) |
3798 | size_index[size_index_elem(i)] = 7; |
3799 | } else if (KMALLOC_MIN_SIZE == 128) { |
3800 | /* |
3801 | * The 192 byte sized cache is not used if the alignment |
3802 | * is 128 byte. Redirect kmalloc to use the 256 byte cache |
3803 | * instead. |
3804 | */ |
3805 | for (i = 128 + 8; i <= 192; i += 8) |
3806 | size_index[size_index_elem(i)] = 8; |
3807 | } |
3808 | |
3809 | /* Caches that are not of the two-to-the-power-of size */ |
3810 | if (KMALLOC_MIN_SIZE <= 32) { |
3811 | kmalloc_caches[1] = create_kmalloc_cache("kmalloc-96", 96, 0); |
3812 | caches++; |
3813 | } |
3814 | |
3815 | if (KMALLOC_MIN_SIZE <= 64) { |
3816 | kmalloc_caches[2] = create_kmalloc_cache("kmalloc-192", 192, 0); |
3817 | caches++; |
3818 | } |
3819 | |
3820 | for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) { |
3821 | kmalloc_caches[i] = create_kmalloc_cache("kmalloc", 1 << i, 0); |
3822 | caches++; |
3823 | } |
3824 | |
3825 | slab_state = UP; |
3826 | |
3827 | /* Provide the correct kmalloc names now that the caches are up */ |
3828 | if (KMALLOC_MIN_SIZE <= 32) { |
3829 | kmalloc_caches[1]->name = kstrdup(kmalloc_caches[1]->name, GFP_NOWAIT); |
3830 | BUG_ON(!kmalloc_caches[1]->name); |
3831 | } |
3832 | |
3833 | if (KMALLOC_MIN_SIZE <= 64) { |
3834 | kmalloc_caches[2]->name = kstrdup(kmalloc_caches[2]->name, GFP_NOWAIT); |
3835 | BUG_ON(!kmalloc_caches[2]->name); |
3836 | } |
3837 | |
3838 | for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) { |
3839 | char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i); |
3840 | |
3841 | BUG_ON(!s); |
3842 | kmalloc_caches[i]->name = s; |
3843 | } |
3844 | |
3845 | #ifdef CONFIG_SMP |
3846 | register_cpu_notifier(&slab_notifier); |
3847 | #endif |
3848 | |
3849 | #ifdef CONFIG_ZONE_DMA |
3850 | for (i = 0; i < SLUB_PAGE_SHIFT; i++) { |
3851 | struct kmem_cache *s = kmalloc_caches[i]; |
3852 | |
3853 | if (s && s->size) { |
3854 | char *name = kasprintf(GFP_NOWAIT, |
3855 | "dma-kmalloc-%d", s->object_size); |
3856 | |
3857 | BUG_ON(!name); |
3858 | kmalloc_dma_caches[i] = create_kmalloc_cache(name, |
3859 | s->object_size, SLAB_CACHE_DMA); |
3860 | } |
3861 | } |
3862 | #endif |
3863 | printk(KERN_INFO |
3864 | "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," |
3865 | " CPUs=%d, Nodes=%d\n", |
3866 | caches, cache_line_size(), |
3867 | slub_min_order, slub_max_order, slub_min_objects, |
3868 | nr_cpu_ids, nr_node_ids); |
3869 | } |
3870 | |
3871 | void __init kmem_cache_init_late(void) |
3872 | { |
3873 | } |
3874 | |
3875 | /* |
3876 | * Find a mergeable slab cache |
3877 | */ |
3878 | static int slab_unmergeable(struct kmem_cache *s) |
3879 | { |
3880 | if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) |
3881 | return 1; |
3882 | |
3883 | if (s->ctor) |
3884 | return 1; |
3885 | |
3886 | /* |
3887 | * We may have set a slab to be unmergeable during bootstrap. |
3888 | */ |
3889 | if (s->refcount < 0) |
3890 | return 1; |
3891 | |
3892 | return 0; |
3893 | } |
3894 | |
3895 | static struct kmem_cache *find_mergeable(size_t size, |
3896 | size_t align, unsigned long flags, const char *name, |
3897 | void (*ctor)(void *)) |
3898 | { |
3899 | struct kmem_cache *s; |
3900 | |
3901 | if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) |
3902 | return NULL; |
3903 | |
3904 | if (ctor) |
3905 | return NULL; |
3906 | |
3907 | size = ALIGN(size, sizeof(void *)); |
3908 | align = calculate_alignment(flags, align, size); |
3909 | size = ALIGN(size, align); |
3910 | flags = kmem_cache_flags(size, flags, name, NULL); |
3911 | |
3912 | list_for_each_entry(s, &slab_caches, list) { |
3913 | if (slab_unmergeable(s)) |
3914 | continue; |
3915 | |
3916 | if (size > s->size) |
3917 | continue; |
3918 | |
3919 | if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) |
3920 | continue; |
3921 | /* |
3922 | * Check if alignment is compatible. |
3923 | * Courtesy of Adrian Drzewiecki |
3924 | */ |
3925 | if ((s->size & ~(align - 1)) != s->size) |
3926 | continue; |
3927 | |
3928 | if (s->size - size >= sizeof(void *)) |
3929 | continue; |
3930 | |
3931 | return s; |
3932 | } |
3933 | return NULL; |
3934 | } |
3935 | |
3936 | struct kmem_cache *__kmem_cache_create(const char *name, size_t size, |
3937 | size_t align, unsigned long flags, void (*ctor)(void *)) |
3938 | { |
3939 | struct kmem_cache *s; |
3940 | char *n; |
3941 | |
3942 | s = find_mergeable(size, align, flags, name, ctor); |
3943 | if (s) { |
3944 | s->refcount++; |
3945 | /* |
3946 | * Adjust the object sizes so that we clear |
3947 | * the complete object on kzalloc. |
3948 | */ |
3949 | s->object_size = max(s->object_size, (int)size); |
3950 | s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *))); |
3951 | |
3952 | if (sysfs_slab_alias(s, name)) { |
3953 | s->refcount--; |
3954 | return NULL; |
3955 | } |
3956 | return s; |
3957 | } |
3958 | |
3959 | n = kstrdup(name, GFP_KERNEL); |
3960 | if (!n) |
3961 | return NULL; |
3962 | |
3963 | s = kmalloc(kmem_size, GFP_KERNEL); |
3964 | if (s) { |
3965 | if (kmem_cache_open(s, n, |
3966 | size, align, flags, ctor)) { |
3967 | int r; |
3968 | |
3969 | list_add(&s->list, &slab_caches); |
3970 | mutex_unlock(&slab_mutex); |
3971 | r = sysfs_slab_add(s); |
3972 | mutex_lock(&slab_mutex); |
3973 | |
3974 | if (!r) |
3975 | return s; |
3976 | |
3977 | list_del(&s->list); |
3978 | kmem_cache_close(s); |
3979 | } |
3980 | kfree(s); |
3981 | } |
3982 | kfree(n); |
3983 | return NULL; |
3984 | } |
3985 | |
3986 | #ifdef CONFIG_SMP |
3987 | /* |
3988 | * Use the cpu notifier to insure that the cpu slabs are flushed when |
3989 | * necessary. |
3990 | */ |
3991 | static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb, |
3992 | unsigned long action, void *hcpu) |
3993 | { |
3994 | long cpu = (long)hcpu; |
3995 | struct kmem_cache *s; |
3996 | unsigned long flags; |
3997 | |
3998 | switch (action) { |
3999 | case CPU_UP_CANCELED: |
4000 | case CPU_UP_CANCELED_FROZEN: |
4001 | case CPU_DEAD: |
4002 | case CPU_DEAD_FROZEN: |
4003 | mutex_lock(&slab_mutex); |
4004 | list_for_each_entry(s, &slab_caches, list) { |
4005 | local_irq_save(flags); |
4006 | __flush_cpu_slab(s, cpu); |
4007 | local_irq_restore(flags); |
4008 | } |
4009 | mutex_unlock(&slab_mutex); |
4010 | break; |
4011 | default: |
4012 | break; |
4013 | } |
4014 | return NOTIFY_OK; |
4015 | } |
4016 | |
4017 | static struct notifier_block __cpuinitdata slab_notifier = { |
4018 | .notifier_call = slab_cpuup_callback |
4019 | }; |
4020 | |
4021 | #endif |
4022 | |
4023 | void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller) |
4024 | { |
4025 | struct kmem_cache *s; |
4026 | void *ret; |
4027 | |
4028 | if (unlikely(size > SLUB_MAX_SIZE)) |
4029 | return kmalloc_large(size, gfpflags); |
4030 | |
4031 | s = get_slab(size, gfpflags); |
4032 | |
4033 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
4034 | return s; |
4035 | |
4036 | ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller); |
4037 | |
4038 | /* Honor the call site pointer we received. */ |
4039 | trace_kmalloc(caller, ret, size, s->size, gfpflags); |
4040 | |
4041 | return ret; |
4042 | } |
4043 | |
4044 | #ifdef CONFIG_NUMA |
4045 | void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, |
4046 | int node, unsigned long caller) |
4047 | { |
4048 | struct kmem_cache *s; |
4049 | void *ret; |
4050 | |
4051 | if (unlikely(size > SLUB_MAX_SIZE)) { |
4052 | ret = kmalloc_large_node(size, gfpflags, node); |
4053 | |
4054 | trace_kmalloc_node(caller, ret, |
4055 | size, PAGE_SIZE << get_order(size), |
4056 | gfpflags, node); |
4057 | |
4058 | return ret; |
4059 | } |
4060 | |
4061 | s = get_slab(size, gfpflags); |
4062 | |
4063 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
4064 | return s; |
4065 | |
4066 | ret = slab_alloc(s, gfpflags, node, caller); |
4067 | |
4068 | /* Honor the call site pointer we received. */ |
4069 | trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node); |
4070 | |
4071 | return ret; |
4072 | } |
4073 | #endif |
4074 | |
4075 | #ifdef CONFIG_SYSFS |
4076 | static int count_inuse(struct page *page) |
4077 | { |
4078 | return page->inuse; |
4079 | } |
4080 | |
4081 | static int count_total(struct page *page) |
4082 | { |
4083 | return page->objects; |
4084 | } |
4085 | #endif |
4086 | |
4087 | #ifdef CONFIG_SLUB_DEBUG |
4088 | static int validate_slab(struct kmem_cache *s, struct page *page, |
4089 | unsigned long *map) |
4090 | { |
4091 | void *p; |
4092 | void *addr = page_address(page); |
4093 | |
4094 | if (!check_slab(s, page) || |
4095 | !on_freelist(s, page, NULL)) |
4096 | return 0; |
4097 | |
4098 | /* Now we know that a valid freelist exists */ |
4099 | bitmap_zero(map, page->objects); |
4100 | |
4101 | get_map(s, page, map); |
4102 | for_each_object(p, s, addr, page->objects) { |
4103 | if (test_bit(slab_index(p, s, addr), map)) |
4104 | if (!check_object(s, page, p, SLUB_RED_INACTIVE)) |
4105 | return 0; |
4106 | } |
4107 | |
4108 | for_each_object(p, s, addr, page->objects) |
4109 | if (!test_bit(slab_index(p, s, addr), map)) |
4110 | if (!check_object(s, page, p, SLUB_RED_ACTIVE)) |
4111 | return 0; |
4112 | return 1; |
4113 | } |
4114 | |
4115 | static void validate_slab_slab(struct kmem_cache *s, struct page *page, |
4116 | unsigned long *map) |
4117 | { |
4118 | slab_lock(page); |
4119 | validate_slab(s, page, map); |
4120 | slab_unlock(page); |
4121 | } |
4122 | |
4123 | static int validate_slab_node(struct kmem_cache *s, |
4124 | struct kmem_cache_node *n, unsigned long *map) |
4125 | { |
4126 | unsigned long count = 0; |
4127 | struct page *page; |
4128 | unsigned long flags; |
4129 | |
4130 | spin_lock_irqsave(&n->list_lock, flags); |
4131 | |
4132 | list_for_each_entry(page, &n->partial, lru) { |
4133 | validate_slab_slab(s, page, map); |
4134 | count++; |
4135 | } |
4136 | if (count != n->nr_partial) |
4137 | printk(KERN_ERR "SLUB %s: %ld partial slabs counted but " |
4138 | "counter=%ld\n", s->name, count, n->nr_partial); |
4139 | |
4140 | if (!(s->flags & SLAB_STORE_USER)) |
4141 | goto out; |
4142 | |
4143 | list_for_each_entry(page, &n->full, lru) { |
4144 | validate_slab_slab(s, page, map); |
4145 | count++; |
4146 | } |
4147 | if (count != atomic_long_read(&n->nr_slabs)) |
4148 | printk(KERN_ERR "SLUB: %s %ld slabs counted but " |
4149 | "counter=%ld\n", s->name, count, |
4150 | atomic_long_read(&n->nr_slabs)); |
4151 | |
4152 | out: |
4153 | spin_unlock_irqrestore(&n->list_lock, flags); |
4154 | return count; |
4155 | } |
4156 | |
4157 | static long validate_slab_cache(struct kmem_cache *s) |
4158 | { |
4159 | int node; |
4160 | unsigned long count = 0; |
4161 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * |
4162 | sizeof(unsigned long), GFP_KERNEL); |
4163 | |
4164 | if (!map) |
4165 | return -ENOMEM; |
4166 | |
4167 | flush_all(s); |
4168 | for_each_node_state(node, N_NORMAL_MEMORY) { |
4169 | struct kmem_cache_node *n = get_node(s, node); |
4170 | |
4171 | count += validate_slab_node(s, n, map); |
4172 | } |
4173 | kfree(map); |
4174 | return count; |
4175 | } |
4176 | /* |
4177 | * Generate lists of code addresses where slabcache objects are allocated |
4178 | * and freed. |
4179 | */ |
4180 | |
4181 | struct location { |
4182 | unsigned long count; |
4183 | unsigned long addr; |
4184 | long long sum_time; |
4185 | long min_time; |
4186 | long max_time; |
4187 | long min_pid; |
4188 | long max_pid; |
4189 | DECLARE_BITMAP(cpus, NR_CPUS); |
4190 | nodemask_t nodes; |
4191 | }; |
4192 | |
4193 | struct loc_track { |
4194 | unsigned long max; |
4195 | unsigned long count; |
4196 | struct location *loc; |
4197 | }; |
4198 | |
4199 | static void free_loc_track(struct loc_track *t) |
4200 | { |
4201 | if (t->max) |
4202 | free_pages((unsigned long)t->loc, |
4203 | get_order(sizeof(struct location) * t->max)); |
4204 | } |
4205 | |
4206 | static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags) |
4207 | { |
4208 | struct location *l; |
4209 | int order; |
4210 | |
4211 | order = get_order(sizeof(struct location) * max); |
4212 | |
4213 | l = (void *)__get_free_pages(flags, order); |
4214 | if (!l) |
4215 | return 0; |
4216 | |
4217 | if (t->count) { |
4218 | memcpy(l, t->loc, sizeof(struct location) * t->count); |
4219 | free_loc_track(t); |
4220 | } |
4221 | t->max = max; |
4222 | t->loc = l; |
4223 | return 1; |
4224 | } |
4225 | |
4226 | static int add_location(struct loc_track *t, struct kmem_cache *s, |
4227 | const struct track *track) |
4228 | { |
4229 | long start, end, pos; |
4230 | struct location *l; |
4231 | unsigned long caddr; |
4232 | unsigned long age = jiffies - track->when; |
4233 | |
4234 | start = -1; |
4235 | end = t->count; |
4236 | |
4237 | for ( ; ; ) { |
4238 | pos = start + (end - start + 1) / 2; |
4239 | |
4240 | /* |
4241 | * There is nothing at "end". If we end up there |
4242 | * we need to add something to before end. |
4243 | */ |
4244 | if (pos == end) |
4245 | break; |
4246 | |
4247 | caddr = t->loc[pos].addr; |
4248 | if (track->addr == caddr) { |
4249 | |
4250 | l = &t->loc[pos]; |
4251 | l->count++; |
4252 | if (track->when) { |
4253 | l->sum_time += age; |
4254 | if (age < l->min_time) |
4255 | l->min_time = age; |
4256 | if (age > l->max_time) |
4257 | l->max_time = age; |
4258 | |
4259 | if (track->pid < l->min_pid) |
4260 | l->min_pid = track->pid; |
4261 | if (track->pid > l->max_pid) |
4262 | l->max_pid = track->pid; |
4263 | |
4264 | cpumask_set_cpu(track->cpu, |
4265 | to_cpumask(l->cpus)); |
4266 | } |
4267 | node_set(page_to_nid(virt_to_page(track)), l->nodes); |
4268 | return 1; |
4269 | } |
4270 | |
4271 | if (track->addr < caddr) |
4272 | end = pos; |
4273 | else |
4274 | start = pos; |
4275 | } |
4276 | |
4277 | /* |
4278 | * Not found. Insert new tracking element. |
4279 | */ |
4280 | if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC)) |
4281 | return 0; |
4282 | |
4283 | l = t->loc + pos; |
4284 | if (pos < t->count) |
4285 | memmove(l + 1, l, |
4286 | (t->count - pos) * sizeof(struct location)); |
4287 | t->count++; |
4288 | l->count = 1; |
4289 | l->addr = track->addr; |
4290 | l->sum_time = age; |
4291 | l->min_time = age; |
4292 | l->max_time = age; |
4293 | l->min_pid = track->pid; |
4294 | l->max_pid = track->pid; |
4295 | cpumask_clear(to_cpumask(l->cpus)); |
4296 | cpumask_set_cpu(track->cpu, to_cpumask(l->cpus)); |
4297 | nodes_clear(l->nodes); |
4298 | node_set(page_to_nid(virt_to_page(track)), l->nodes); |
4299 | return 1; |
4300 | } |
4301 | |
4302 | static void process_slab(struct loc_track *t, struct kmem_cache *s, |
4303 | struct page *page, enum track_item alloc, |
4304 | unsigned long *map) |
4305 | { |
4306 | void *addr = page_address(page); |
4307 | void *p; |
4308 | |
4309 | bitmap_zero(map, page->objects); |
4310 | get_map(s, page, map); |
4311 | |
4312 | for_each_object(p, s, addr, page->objects) |
4313 | if (!test_bit(slab_index(p, s, addr), map)) |
4314 | add_location(t, s, get_track(s, p, alloc)); |
4315 | } |
4316 | |
4317 | static int list_locations(struct kmem_cache *s, char *buf, |
4318 | enum track_item alloc) |
4319 | { |
4320 | int len = 0; |
4321 | unsigned long i; |
4322 | struct loc_track t = { 0, 0, NULL }; |
4323 | int node; |
4324 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * |
4325 | sizeof(unsigned long), GFP_KERNEL); |
4326 | |
4327 | if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), |
4328 | GFP_TEMPORARY)) { |
4329 | kfree(map); |
4330 | return sprintf(buf, "Out of memory\n"); |
4331 | } |
4332 | /* Push back cpu slabs */ |
4333 | flush_all(s); |
4334 | |
4335 | for_each_node_state(node, N_NORMAL_MEMORY) { |
4336 | struct kmem_cache_node *n = get_node(s, node); |
4337 | unsigned long flags; |
4338 | struct page *page; |
4339 | |
4340 | if (!atomic_long_read(&n->nr_slabs)) |
4341 | continue; |
4342 | |
4343 | spin_lock_irqsave(&n->list_lock, flags); |
4344 | list_for_each_entry(page, &n->partial, lru) |
4345 | process_slab(&t, s, page, alloc, map); |
4346 | list_for_each_entry(page, &n->full, lru) |
4347 | process_slab(&t, s, page, alloc, map); |
4348 | spin_unlock_irqrestore(&n->list_lock, flags); |
4349 | } |
4350 | |
4351 | for (i = 0; i < t.count; i++) { |
4352 | struct location *l = &t.loc[i]; |
4353 | |
4354 | if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100) |
4355 | break; |
4356 | len += sprintf(buf + len, "%7ld ", l->count); |
4357 | |
4358 | if (l->addr) |
4359 | len += sprintf(buf + len, "%pS", (void *)l->addr); |
4360 | else |
4361 | len += sprintf(buf + len, "<not-available>"); |
4362 | |
4363 | if (l->sum_time != l->min_time) { |
4364 | len += sprintf(buf + len, " age=%ld/%ld/%ld", |
4365 | l->min_time, |
4366 | (long)div_u64(l->sum_time, l->count), |
4367 | l->max_time); |
4368 | } else |
4369 | len += sprintf(buf + len, " age=%ld", |
4370 | l->min_time); |
4371 | |
4372 | if (l->min_pid != l->max_pid) |
4373 | len += sprintf(buf + len, " pid=%ld-%ld", |
4374 | l->min_pid, l->max_pid); |
4375 | else |
4376 | len += sprintf(buf + len, " pid=%ld", |
4377 | l->min_pid); |
4378 | |
4379 | if (num_online_cpus() > 1 && |
4380 | !cpumask_empty(to_cpumask(l->cpus)) && |
4381 | len < PAGE_SIZE - 60) { |
4382 | len += sprintf(buf + len, " cpus="); |
4383 | len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50, |
4384 | to_cpumask(l->cpus)); |
4385 | } |
4386 | |
4387 | if (nr_online_nodes > 1 && !nodes_empty(l->nodes) && |
4388 | len < PAGE_SIZE - 60) { |
4389 | len += sprintf(buf + len, " nodes="); |
4390 | len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50, |
4391 | l->nodes); |
4392 | } |
4393 | |
4394 | len += sprintf(buf + len, "\n"); |
4395 | } |
4396 | |
4397 | free_loc_track(&t); |
4398 | kfree(map); |
4399 | if (!t.count) |
4400 | len += sprintf(buf, "No data\n"); |
4401 | return len; |
4402 | } |
4403 | #endif |
4404 | |
4405 | #ifdef SLUB_RESILIENCY_TEST |
4406 | static void resiliency_test(void) |
4407 | { |
4408 | u8 *p; |
4409 | |
4410 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || SLUB_PAGE_SHIFT < 10); |
4411 | |
4412 | printk(KERN_ERR "SLUB resiliency testing\n"); |
4413 | printk(KERN_ERR "-----------------------\n"); |
4414 | printk(KERN_ERR "A. Corruption after allocation\n"); |
4415 | |
4416 | p = kzalloc(16, GFP_KERNEL); |
4417 | p[16] = 0x12; |
4418 | printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer" |
4419 | " 0x12->0x%p\n\n", p + 16); |
4420 | |
4421 | validate_slab_cache(kmalloc_caches[4]); |
4422 | |
4423 | /* Hmmm... The next two are dangerous */ |
4424 | p = kzalloc(32, GFP_KERNEL); |
4425 | p[32 + sizeof(void *)] = 0x34; |
4426 | printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab" |
4427 | " 0x34 -> -0x%p\n", p); |
4428 | printk(KERN_ERR |
4429 | "If allocated object is overwritten then not detectable\n\n"); |
4430 | |
4431 | validate_slab_cache(kmalloc_caches[5]); |
4432 | p = kzalloc(64, GFP_KERNEL); |
4433 | p += 64 + (get_cycles() & 0xff) * sizeof(void *); |
4434 | *p = 0x56; |
4435 | printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n", |
4436 | p); |
4437 | printk(KERN_ERR |
4438 | "If allocated object is overwritten then not detectable\n\n"); |
4439 | validate_slab_cache(kmalloc_caches[6]); |
4440 | |
4441 | printk(KERN_ERR "\nB. Corruption after free\n"); |
4442 | p = kzalloc(128, GFP_KERNEL); |
4443 | kfree(p); |
4444 | *p = 0x78; |
4445 | printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p); |
4446 | validate_slab_cache(kmalloc_caches[7]); |
4447 | |
4448 | p = kzalloc(256, GFP_KERNEL); |
4449 | kfree(p); |
4450 | p[50] = 0x9a; |
4451 | printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", |
4452 | p); |
4453 | validate_slab_cache(kmalloc_caches[8]); |
4454 | |
4455 | p = kzalloc(512, GFP_KERNEL); |
4456 | kfree(p); |
4457 | p[512] = 0xab; |
4458 | printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p); |
4459 | validate_slab_cache(kmalloc_caches[9]); |
4460 | } |
4461 | #else |
4462 | #ifdef CONFIG_SYSFS |
4463 | static void resiliency_test(void) {}; |
4464 | #endif |
4465 | #endif |
4466 | |
4467 | #ifdef CONFIG_SYSFS |
4468 | enum slab_stat_type { |
4469 | SL_ALL, /* All slabs */ |
4470 | SL_PARTIAL, /* Only partially allocated slabs */ |
4471 | SL_CPU, /* Only slabs used for cpu caches */ |
4472 | SL_OBJECTS, /* Determine allocated objects not slabs */ |
4473 | SL_TOTAL /* Determine object capacity not slabs */ |
4474 | }; |
4475 | |
4476 | #define SO_ALL (1 << SL_ALL) |
4477 | #define SO_PARTIAL (1 << SL_PARTIAL) |
4478 | #define SO_CPU (1 << SL_CPU) |
4479 | #define SO_OBJECTS (1 << SL_OBJECTS) |
4480 | #define SO_TOTAL (1 << SL_TOTAL) |
4481 | |
4482 | static ssize_t show_slab_objects(struct kmem_cache *s, |
4483 | char *buf, unsigned long flags) |
4484 | { |
4485 | unsigned long total = 0; |
4486 | int node; |
4487 | int x; |
4488 | unsigned long *nodes; |
4489 | unsigned long *per_cpu; |
4490 | |
4491 | nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); |
4492 | if (!nodes) |
4493 | return -ENOMEM; |
4494 | per_cpu = nodes + nr_node_ids; |
4495 | |
4496 | if (flags & SO_CPU) { |
4497 | int cpu; |
4498 | |
4499 | for_each_possible_cpu(cpu) { |
4500 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); |
4501 | int node; |
4502 | struct page *page; |
4503 | |
4504 | page = ACCESS_ONCE(c->page); |
4505 | if (!page) |
4506 | continue; |
4507 | |
4508 | node = page_to_nid(page); |
4509 | if (flags & SO_TOTAL) |
4510 | x = page->objects; |
4511 | else if (flags & SO_OBJECTS) |
4512 | x = page->inuse; |
4513 | else |
4514 | x = 1; |
4515 | |
4516 | total += x; |
4517 | nodes[node] += x; |
4518 | |
4519 | page = ACCESS_ONCE(c->partial); |
4520 | if (page) { |
4521 | x = page->pobjects; |
4522 | total += x; |
4523 | nodes[node] += x; |
4524 | } |
4525 | |
4526 | per_cpu[node]++; |
4527 | } |
4528 | } |
4529 | |
4530 | lock_memory_hotplug(); |
4531 | #ifdef CONFIG_SLUB_DEBUG |
4532 | if (flags & SO_ALL) { |
4533 | for_each_node_state(node, N_NORMAL_MEMORY) { |
4534 | struct kmem_cache_node *n = get_node(s, node); |
4535 | |
4536 | if (flags & SO_TOTAL) |
4537 | x = atomic_long_read(&n->total_objects); |
4538 | else if (flags & SO_OBJECTS) |
4539 | x = atomic_long_read(&n->total_objects) - |
4540 | count_partial(n, count_free); |
4541 | |
4542 | else |
4543 | x = atomic_long_read(&n->nr_slabs); |
4544 | total += x; |
4545 | nodes[node] += x; |
4546 | } |
4547 | |
4548 | } else |
4549 | #endif |
4550 | if (flags & SO_PARTIAL) { |
4551 | for_each_node_state(node, N_NORMAL_MEMORY) { |
4552 | struct kmem_cache_node *n = get_node(s, node); |
4553 | |
4554 | if (flags & SO_TOTAL) |
4555 | x = count_partial(n, count_total); |
4556 | else if (flags & SO_OBJECTS) |
4557 | x = count_partial(n, count_inuse); |
4558 | else |
4559 | x = n->nr_partial; |
4560 | total += x; |
4561 | nodes[node] += x; |
4562 | } |
4563 | } |
4564 | x = sprintf(buf, "%lu", total); |
4565 | #ifdef CONFIG_NUMA |
4566 | for_each_node_state(node, N_NORMAL_MEMORY) |
4567 | if (nodes[node]) |
4568 | x += sprintf(buf + x, " N%d=%lu", |
4569 | node, nodes[node]); |
4570 | #endif |
4571 | unlock_memory_hotplug(); |
4572 | kfree(nodes); |
4573 | return x + sprintf(buf + x, "\n"); |
4574 | } |
4575 | |
4576 | #ifdef CONFIG_SLUB_DEBUG |
4577 | static int any_slab_objects(struct kmem_cache *s) |
4578 | { |
4579 | int node; |
4580 | |
4581 | for_each_online_node(node) { |
4582 | struct kmem_cache_node *n = get_node(s, node); |
4583 | |
4584 | if (!n) |
4585 | continue; |
4586 | |
4587 | if (atomic_long_read(&n->total_objects)) |
4588 | return 1; |
4589 | } |
4590 | return 0; |
4591 | } |
4592 | #endif |
4593 | |
4594 | #define to_slab_attr(n) container_of(n, struct slab_attribute, attr) |
4595 | #define to_slab(n) container_of(n, struct kmem_cache, kobj) |
4596 | |
4597 | struct slab_attribute { |
4598 | struct attribute attr; |
4599 | ssize_t (*show)(struct kmem_cache *s, char *buf); |
4600 | ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); |
4601 | }; |
4602 | |
4603 | #define SLAB_ATTR_RO(_name) \ |
4604 | static struct slab_attribute _name##_attr = \ |
4605 | __ATTR(_name, 0400, _name##_show, NULL) |
4606 | |
4607 | #define SLAB_ATTR(_name) \ |
4608 | static struct slab_attribute _name##_attr = \ |
4609 | __ATTR(_name, 0600, _name##_show, _name##_store) |
4610 | |
4611 | static ssize_t slab_size_show(struct kmem_cache *s, char *buf) |
4612 | { |
4613 | return sprintf(buf, "%d\n", s->size); |
4614 | } |
4615 | SLAB_ATTR_RO(slab_size); |
4616 | |
4617 | static ssize_t align_show(struct kmem_cache *s, char *buf) |
4618 | { |
4619 | return sprintf(buf, "%d\n", s->align); |
4620 | } |
4621 | SLAB_ATTR_RO(align); |
4622 | |
4623 | static ssize_t object_size_show(struct kmem_cache *s, char *buf) |
4624 | { |
4625 | return sprintf(buf, "%d\n", s->object_size); |
4626 | } |
4627 | SLAB_ATTR_RO(object_size); |
4628 | |
4629 | static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf) |
4630 | { |
4631 | return sprintf(buf, "%d\n", oo_objects(s->oo)); |
4632 | } |
4633 | SLAB_ATTR_RO(objs_per_slab); |
4634 | |
4635 | static ssize_t order_store(struct kmem_cache *s, |
4636 | const char *buf, size_t length) |
4637 | { |
4638 | unsigned long order; |
4639 | int err; |
4640 | |
4641 | err = strict_strtoul(buf, 10, &order); |
4642 | if (err) |
4643 | return err; |
4644 | |
4645 | if (order > slub_max_order || order < slub_min_order) |
4646 | return -EINVAL; |
4647 | |
4648 | calculate_sizes(s, order); |
4649 | return length; |
4650 | } |
4651 | |
4652 | static ssize_t order_show(struct kmem_cache *s, char *buf) |
4653 | { |
4654 | return sprintf(buf, "%d\n", oo_order(s->oo)); |
4655 | } |
4656 | SLAB_ATTR(order); |
4657 | |
4658 | static ssize_t min_partial_show(struct kmem_cache *s, char *buf) |
4659 | { |
4660 | return sprintf(buf, "%lu\n", s->min_partial); |
4661 | } |
4662 | |
4663 | static ssize_t min_partial_store(struct kmem_cache *s, const char *buf, |
4664 | size_t length) |
4665 | { |
4666 | unsigned long min; |
4667 | int err; |
4668 | |
4669 | err = strict_strtoul(buf, 10, &min); |
4670 | if (err) |
4671 | return err; |
4672 | |
4673 | set_min_partial(s, min); |
4674 | return length; |
4675 | } |
4676 | SLAB_ATTR(min_partial); |
4677 | |
4678 | static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf) |
4679 | { |
4680 | return sprintf(buf, "%u\n", s->cpu_partial); |
4681 | } |
4682 | |
4683 | static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf, |
4684 | size_t length) |
4685 | { |
4686 | unsigned long objects; |
4687 | int err; |
4688 | |
4689 | err = strict_strtoul(buf, 10, &objects); |
4690 | if (err) |
4691 | return err; |
4692 | if (objects && kmem_cache_debug(s)) |
4693 | return -EINVAL; |
4694 | |
4695 | s->cpu_partial = objects; |
4696 | flush_all(s); |
4697 | return length; |
4698 | } |
4699 | SLAB_ATTR(cpu_partial); |
4700 | |
4701 | static ssize_t ctor_show(struct kmem_cache *s, char *buf) |
4702 | { |
4703 | if (!s->ctor) |
4704 | return 0; |
4705 | return sprintf(buf, "%pS\n", s->ctor); |
4706 | } |
4707 | SLAB_ATTR_RO(ctor); |
4708 | |
4709 | static ssize_t aliases_show(struct kmem_cache *s, char *buf) |
4710 | { |
4711 | return sprintf(buf, "%d\n", s->refcount - 1); |
4712 | } |
4713 | SLAB_ATTR_RO(aliases); |
4714 | |
4715 | static ssize_t partial_show(struct kmem_cache *s, char *buf) |
4716 | { |
4717 | return show_slab_objects(s, buf, SO_PARTIAL); |
4718 | } |
4719 | SLAB_ATTR_RO(partial); |
4720 | |
4721 | static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) |
4722 | { |
4723 | return show_slab_objects(s, buf, SO_CPU); |
4724 | } |
4725 | SLAB_ATTR_RO(cpu_slabs); |
4726 | |
4727 | static ssize_t objects_show(struct kmem_cache *s, char *buf) |
4728 | { |
4729 | return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS); |
4730 | } |
4731 | SLAB_ATTR_RO(objects); |
4732 | |
4733 | static ssize_t objects_partial_show(struct kmem_cache *s, char *buf) |
4734 | { |
4735 | return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS); |
4736 | } |
4737 | SLAB_ATTR_RO(objects_partial); |
4738 | |
4739 | static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf) |
4740 | { |
4741 | int objects = 0; |
4742 | int pages = 0; |
4743 | int cpu; |
4744 | int len; |
4745 | |
4746 | for_each_online_cpu(cpu) { |
4747 | struct page *page = per_cpu_ptr(s->cpu_slab, cpu)->partial; |
4748 | |
4749 | if (page) { |
4750 | pages += page->pages; |
4751 | objects += page->pobjects; |
4752 | } |
4753 | } |
4754 | |
4755 | len = sprintf(buf, "%d(%d)", objects, pages); |
4756 | |
4757 | #ifdef CONFIG_SMP |
4758 | for_each_online_cpu(cpu) { |
4759 | struct page *page = per_cpu_ptr(s->cpu_slab, cpu) ->partial; |
4760 | |
4761 | if (page && len < PAGE_SIZE - 20) |
4762 | len += sprintf(buf + len, " C%d=%d(%d)", cpu, |
4763 | page->pobjects, page->pages); |
4764 | } |
4765 | #endif |
4766 | return len + sprintf(buf + len, "\n"); |
4767 | } |
4768 | SLAB_ATTR_RO(slabs_cpu_partial); |
4769 | |
4770 | static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) |
4771 | { |
4772 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); |
4773 | } |
4774 | |
4775 | static ssize_t reclaim_account_store(struct kmem_cache *s, |
4776 | const char *buf, size_t length) |
4777 | { |
4778 | s->flags &= ~SLAB_RECLAIM_ACCOUNT; |
4779 | if (buf[0] == '1') |
4780 | s->flags |= SLAB_RECLAIM_ACCOUNT; |
4781 | return length; |
4782 | } |
4783 | SLAB_ATTR(reclaim_account); |
4784 | |
4785 | static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) |
4786 | { |
4787 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN)); |
4788 | } |
4789 | SLAB_ATTR_RO(hwcache_align); |
4790 | |
4791 | #ifdef CONFIG_ZONE_DMA |
4792 | static ssize_t cache_dma_show(struct kmem_cache *s, char *buf) |
4793 | { |
4794 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA)); |
4795 | } |
4796 | SLAB_ATTR_RO(cache_dma); |
4797 | #endif |
4798 | |
4799 | static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) |
4800 | { |
4801 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU)); |
4802 | } |
4803 | SLAB_ATTR_RO(destroy_by_rcu); |
4804 | |
4805 | static ssize_t reserved_show(struct kmem_cache *s, char *buf) |
4806 | { |
4807 | return sprintf(buf, "%d\n", s->reserved); |
4808 | } |
4809 | SLAB_ATTR_RO(reserved); |
4810 | |
4811 | #ifdef CONFIG_SLUB_DEBUG |
4812 | static ssize_t slabs_show(struct kmem_cache *s, char *buf) |
4813 | { |
4814 | return show_slab_objects(s, buf, SO_ALL); |
4815 | } |
4816 | SLAB_ATTR_RO(slabs); |
4817 | |
4818 | static ssize_t total_objects_show(struct kmem_cache *s, char *buf) |
4819 | { |
4820 | return show_slab_objects(s, buf, SO_ALL|SO_TOTAL); |
4821 | } |
4822 | SLAB_ATTR_RO(total_objects); |
4823 | |
4824 | static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf) |
4825 | { |
4826 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE)); |
4827 | } |
4828 | |
4829 | static ssize_t sanity_checks_store(struct kmem_cache *s, |
4830 | const char *buf, size_t length) |
4831 | { |
4832 | s->flags &= ~SLAB_DEBUG_FREE; |
4833 | if (buf[0] == '1') { |
4834 | s->flags &= ~__CMPXCHG_DOUBLE; |
4835 | s->flags |= SLAB_DEBUG_FREE; |
4836 | } |
4837 | return length; |
4838 | } |
4839 | SLAB_ATTR(sanity_checks); |
4840 | |
4841 | static ssize_t trace_show(struct kmem_cache *s, char *buf) |
4842 | { |
4843 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE)); |
4844 | } |
4845 | |
4846 | static ssize_t trace_store(struct kmem_cache *s, const char *buf, |
4847 | size_t length) |
4848 | { |
4849 | s->flags &= ~SLAB_TRACE; |
4850 | if (buf[0] == '1') { |
4851 | s->flags &= ~__CMPXCHG_DOUBLE; |
4852 | s->flags |= SLAB_TRACE; |
4853 | } |
4854 | return length; |
4855 | } |
4856 | SLAB_ATTR(trace); |
4857 | |
4858 | static ssize_t red_zone_show(struct kmem_cache *s, char *buf) |
4859 | { |
4860 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE)); |
4861 | } |
4862 | |
4863 | static ssize_t red_zone_store(struct kmem_cache *s, |
4864 | const char *buf, size_t length) |
4865 | { |
4866 | if (any_slab_objects(s)) |
4867 | return -EBUSY; |
4868 | |
4869 | s->flags &= ~SLAB_RED_ZONE; |
4870 | if (buf[0] == '1') { |
4871 | s->flags &= ~__CMPXCHG_DOUBLE; |
4872 | s->flags |= SLAB_RED_ZONE; |
4873 | } |
4874 | calculate_sizes(s, -1); |
4875 | return length; |
4876 | } |
4877 | SLAB_ATTR(red_zone); |
4878 | |
4879 | static ssize_t poison_show(struct kmem_cache *s, char *buf) |
4880 | { |
4881 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON)); |
4882 | } |
4883 | |
4884 | static ssize_t poison_store(struct kmem_cache *s, |
4885 | const char *buf, size_t length) |
4886 | { |
4887 | if (any_slab_objects(s)) |
4888 | return -EBUSY; |
4889 | |
4890 | s->flags &= ~SLAB_POISON; |
4891 | if (buf[0] == '1') { |
4892 | s->flags &= ~__CMPXCHG_DOUBLE; |
4893 | s->flags |= SLAB_POISON; |
4894 | } |
4895 | calculate_sizes(s, -1); |
4896 | return length; |
4897 | } |
4898 | SLAB_ATTR(poison); |
4899 | |
4900 | static ssize_t store_user_show(struct kmem_cache *s, char *buf) |
4901 | { |
4902 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER)); |
4903 | } |
4904 | |
4905 | static ssize_t store_user_store(struct kmem_cache *s, |
4906 | const char *buf, size_t length) |
4907 | { |
4908 | if (any_slab_objects(s)) |
4909 | return -EBUSY; |
4910 | |
4911 | s->flags &= ~SLAB_STORE_USER; |
4912 | if (buf[0] == '1') { |
4913 | s->flags &= ~__CMPXCHG_DOUBLE; |
4914 | s->flags |= SLAB_STORE_USER; |
4915 | } |
4916 | calculate_sizes(s, -1); |
4917 | return length; |
4918 | } |
4919 | SLAB_ATTR(store_user); |
4920 | |
4921 | static ssize_t validate_show(struct kmem_cache *s, char *buf) |
4922 | { |
4923 | return 0; |
4924 | } |
4925 | |
4926 | static ssize_t validate_store(struct kmem_cache *s, |
4927 | const char *buf, size_t length) |
4928 | { |
4929 | int ret = -EINVAL; |
4930 | |
4931 | if (buf[0] == '1') { |
4932 | ret = validate_slab_cache(s); |
4933 | if (ret >= 0) |
4934 | ret = length; |
4935 | } |
4936 | return ret; |
4937 | } |
4938 | SLAB_ATTR(validate); |
4939 | |
4940 | static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) |
4941 | { |
4942 | if (!(s->flags & SLAB_STORE_USER)) |
4943 | return -ENOSYS; |
4944 | return list_locations(s, buf, TRACK_ALLOC); |
4945 | } |
4946 | SLAB_ATTR_RO(alloc_calls); |
4947 | |
4948 | static ssize_t free_calls_show(struct kmem_cache *s, char *buf) |
4949 | { |
4950 | if (!(s->flags & SLAB_STORE_USER)) |
4951 | return -ENOSYS; |
4952 | return list_locations(s, buf, TRACK_FREE); |
4953 | } |
4954 | SLAB_ATTR_RO(free_calls); |
4955 | #endif /* CONFIG_SLUB_DEBUG */ |
4956 | |
4957 | #ifdef CONFIG_FAILSLAB |
4958 | static ssize_t failslab_show(struct kmem_cache *s, char *buf) |
4959 | { |
4960 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB)); |
4961 | } |
4962 | |
4963 | static ssize_t failslab_store(struct kmem_cache *s, const char *buf, |
4964 | size_t length) |
4965 | { |
4966 | s->flags &= ~SLAB_FAILSLAB; |
4967 | if (buf[0] == '1') |
4968 | s->flags |= SLAB_FAILSLAB; |
4969 | return length; |
4970 | } |
4971 | SLAB_ATTR(failslab); |
4972 | #endif |
4973 | |
4974 | static ssize_t shrink_show(struct kmem_cache *s, char *buf) |
4975 | { |
4976 | return 0; |
4977 | } |
4978 | |
4979 | static ssize_t shrink_store(struct kmem_cache *s, |
4980 | const char *buf, size_t length) |
4981 | { |
4982 | if (buf[0] == '1') { |
4983 | int rc = kmem_cache_shrink(s); |
4984 | |
4985 | if (rc) |
4986 | return rc; |
4987 | } else |
4988 | return -EINVAL; |
4989 | return length; |
4990 | } |
4991 | SLAB_ATTR(shrink); |
4992 | |
4993 | #ifdef CONFIG_NUMA |
4994 | static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf) |
4995 | { |
4996 | return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10); |
4997 | } |
4998 | |
4999 | static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s, |
5000 | const char *buf, size_t length) |
5001 | { |
5002 | unsigned long ratio; |
5003 | int err; |
5004 | |
5005 | err = strict_strtoul(buf, 10, &ratio); |
5006 | if (err) |
5007 | return err; |
5008 | |
5009 | if (ratio <= 100) |
5010 | s->remote_node_defrag_ratio = ratio * 10; |
5011 | |
5012 | return length; |
5013 | } |
5014 | SLAB_ATTR(remote_node_defrag_ratio); |
5015 | #endif |
5016 | |
5017 | #ifdef CONFIG_SLUB_STATS |
5018 | static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si) |
5019 | { |
5020 | unsigned long sum = 0; |
5021 | int cpu; |
5022 | int len; |
5023 | int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL); |
5024 | |
5025 | if (!data) |
5026 | return -ENOMEM; |
5027 | |
5028 | for_each_online_cpu(cpu) { |
5029 | unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si]; |
5030 | |
5031 | data[cpu] = x; |
5032 | sum += x; |
5033 | } |
5034 | |
5035 | len = sprintf(buf, "%lu", sum); |
5036 | |
5037 | #ifdef CONFIG_SMP |
5038 | for_each_online_cpu(cpu) { |
5039 | if (data[cpu] && len < PAGE_SIZE - 20) |
5040 | len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]); |
5041 | } |
5042 | #endif |
5043 | kfree(data); |
5044 | return len + sprintf(buf + len, "\n"); |
5045 | } |
5046 | |
5047 | static void clear_stat(struct kmem_cache *s, enum stat_item si) |
5048 | { |
5049 | int cpu; |
5050 | |
5051 | for_each_online_cpu(cpu) |
5052 | per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0; |
5053 | } |
5054 | |
5055 | #define STAT_ATTR(si, text) \ |
5056 | static ssize_t text##_show(struct kmem_cache *s, char *buf) \ |
5057 | { \ |
5058 | return show_stat(s, buf, si); \ |
5059 | } \ |
5060 | static ssize_t text##_store(struct kmem_cache *s, \ |
5061 | const char *buf, size_t length) \ |
5062 | { \ |
5063 | if (buf[0] != '0') \ |
5064 | return -EINVAL; \ |
5065 | clear_stat(s, si); \ |
5066 | return length; \ |
5067 | } \ |
5068 | SLAB_ATTR(text); \ |
5069 | |
5070 | STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath); |
5071 | STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath); |
5072 | STAT_ATTR(FREE_FASTPATH, free_fastpath); |
5073 | STAT_ATTR(FREE_SLOWPATH, free_slowpath); |
5074 | STAT_ATTR(FREE_FROZEN, free_frozen); |
5075 | STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial); |
5076 | STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial); |
5077 | STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial); |
5078 | STAT_ATTR(ALLOC_SLAB, alloc_slab); |
5079 | STAT_ATTR(ALLOC_REFILL, alloc_refill); |
5080 | STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch); |
5081 | STAT_ATTR(FREE_SLAB, free_slab); |
5082 | STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush); |
5083 | STAT_ATTR(DEACTIVATE_FULL, deactivate_full); |
5084 | STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty); |
5085 | STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head); |
5086 | STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail); |
5087 | STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees); |
5088 | STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass); |
5089 | STAT_ATTR(ORDER_FALLBACK, order_fallback); |
5090 | STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail); |
5091 | STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail); |
5092 | STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc); |
5093 | STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free); |
5094 | STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node); |
5095 | STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain); |
5096 | #endif |
5097 | |
5098 | static struct attribute *slab_attrs[] = { |
5099 | &slab_size_attr.attr, |
5100 | &object_size_attr.attr, |
5101 | &objs_per_slab_attr.attr, |
5102 | &order_attr.attr, |
5103 | &min_partial_attr.attr, |
5104 | &cpu_partial_attr.attr, |
5105 | &objects_attr.attr, |
5106 | &objects_partial_attr.attr, |
5107 | &partial_attr.attr, |
5108 | &cpu_slabs_attr.attr, |
5109 | &ctor_attr.attr, |
5110 | &aliases_attr.attr, |
5111 | &align_attr.attr, |
5112 | &hwcache_align_attr.attr, |
5113 | &reclaim_account_attr.attr, |
5114 | &destroy_by_rcu_attr.attr, |
5115 | &shrink_attr.attr, |
5116 | &reserved_attr.attr, |
5117 | &slabs_cpu_partial_attr.attr, |
5118 | #ifdef CONFIG_SLUB_DEBUG |
5119 | &total_objects_attr.attr, |
5120 | &slabs_attr.attr, |
5121 | &sanity_checks_attr.attr, |
5122 | &trace_attr.attr, |
5123 | &red_zone_attr.attr, |
5124 | &poison_attr.attr, |
5125 | &store_user_attr.attr, |
5126 | &validate_attr.attr, |
5127 | &alloc_calls_attr.attr, |
5128 | &free_calls_attr.attr, |
5129 | #endif |
5130 | #ifdef CONFIG_ZONE_DMA |
5131 | &cache_dma_attr.attr, |
5132 | #endif |
5133 | #ifdef CONFIG_NUMA |
5134 | &remote_node_defrag_ratio_attr.attr, |
5135 | #endif |
5136 | #ifdef CONFIG_SLUB_STATS |
5137 | &alloc_fastpath_attr.attr, |
5138 | &alloc_slowpath_attr.attr, |
5139 | &free_fastpath_attr.attr, |
5140 | &free_slowpath_attr.attr, |
5141 | &free_frozen_attr.attr, |
5142 | &free_add_partial_attr.attr, |
5143 | &free_remove_partial_attr.attr, |
5144 | &alloc_from_partial_attr.attr, |
5145 | &alloc_slab_attr.attr, |
5146 | &alloc_refill_attr.attr, |
5147 | &alloc_node_mismatch_attr.attr, |
5148 | &free_slab_attr.attr, |
5149 | &cpuslab_flush_attr.attr, |
5150 | &deactivate_full_attr.attr, |
5151 | &deactivate_empty_attr.attr, |
5152 | &deactivate_to_head_attr.attr, |
5153 | &deactivate_to_tail_attr.attr, |
5154 | &deactivate_remote_frees_attr.attr, |
5155 | &deactivate_bypass_attr.attr, |
5156 | &order_fallback_attr.attr, |
5157 | &cmpxchg_double_fail_attr.attr, |
5158 | &cmpxchg_double_cpu_fail_attr.attr, |
5159 | &cpu_partial_alloc_attr.attr, |
5160 | &cpu_partial_free_attr.attr, |
5161 | &cpu_partial_node_attr.attr, |
5162 | &cpu_partial_drain_attr.attr, |
5163 | #endif |
5164 | #ifdef CONFIG_FAILSLAB |
5165 | &failslab_attr.attr, |
5166 | #endif |
5167 | |
5168 | NULL |
5169 | }; |
5170 | |
5171 | static struct attribute_group slab_attr_group = { |
5172 | .attrs = slab_attrs, |
5173 | }; |
5174 | |
5175 | static ssize_t slab_attr_show(struct kobject *kobj, |
5176 | struct attribute *attr, |
5177 | char *buf) |
5178 | { |
5179 | struct slab_attribute *attribute; |
5180 | struct kmem_cache *s; |
5181 | int err; |
5182 | |
5183 | attribute = to_slab_attr(attr); |
5184 | s = to_slab(kobj); |
5185 | |
5186 | if (!attribute->show) |
5187 | return -EIO; |
5188 | |
5189 | err = attribute->show(s, buf); |
5190 | |
5191 | return err; |
5192 | } |
5193 | |
5194 | static ssize_t slab_attr_store(struct kobject *kobj, |
5195 | struct attribute *attr, |
5196 | const char *buf, size_t len) |
5197 | { |
5198 | struct slab_attribute *attribute; |
5199 | struct kmem_cache *s; |
5200 | int err; |
5201 | |
5202 | attribute = to_slab_attr(attr); |
5203 | s = to_slab(kobj); |
5204 | |
5205 | if (!attribute->store) |
5206 | return -EIO; |
5207 | |
5208 | err = attribute->store(s, buf, len); |
5209 | |
5210 | return err; |
5211 | } |
5212 | |
5213 | static void kmem_cache_release(struct kobject *kobj) |
5214 | { |
5215 | struct kmem_cache *s = to_slab(kobj); |
5216 | |
5217 | kfree(s->name); |
5218 | kfree(s); |
5219 | } |
5220 | |
5221 | static const struct sysfs_ops slab_sysfs_ops = { |
5222 | .show = slab_attr_show, |
5223 | .store = slab_attr_store, |
5224 | }; |
5225 | |
5226 | static struct kobj_type slab_ktype = { |
5227 | .sysfs_ops = &slab_sysfs_ops, |
5228 | .release = kmem_cache_release |
5229 | }; |
5230 | |
5231 | static int uevent_filter(struct kset *kset, struct kobject *kobj) |
5232 | { |
5233 | struct kobj_type *ktype = get_ktype(kobj); |
5234 | |
5235 | if (ktype == &slab_ktype) |
5236 | return 1; |
5237 | return 0; |
5238 | } |
5239 | |
5240 | static const struct kset_uevent_ops slab_uevent_ops = { |
5241 | .filter = uevent_filter, |
5242 | }; |
5243 | |
5244 | static struct kset *slab_kset; |
5245 | |
5246 | #define ID_STR_LENGTH 64 |
5247 | |
5248 | /* Create a unique string id for a slab cache: |
5249 | * |
5250 | * Format :[flags-]size |
5251 | */ |
5252 | static char *create_unique_id(struct kmem_cache *s) |
5253 | { |
5254 | char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); |
5255 | char *p = name; |
5256 | |
5257 | BUG_ON(!name); |
5258 | |
5259 | *p++ = ':'; |
5260 | /* |
5261 | * First flags affecting slabcache operations. We will only |
5262 | * get here for aliasable slabs so we do not need to support |
5263 | * too many flags. The flags here must cover all flags that |
5264 | * are matched during merging to guarantee that the id is |
5265 | * unique. |
5266 | */ |
5267 | if (s->flags & SLAB_CACHE_DMA) |
5268 | *p++ = 'd'; |
5269 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
5270 | *p++ = 'a'; |
5271 | if (s->flags & SLAB_DEBUG_FREE) |
5272 | *p++ = 'F'; |
5273 | if (!(s->flags & SLAB_NOTRACK)) |
5274 | *p++ = 't'; |
5275 | if (p != name + 1) |
5276 | *p++ = '-'; |
5277 | p += sprintf(p, "%07d", s->size); |
5278 | BUG_ON(p > name + ID_STR_LENGTH - 1); |
5279 | return name; |
5280 | } |
5281 | |
5282 | static int sysfs_slab_add(struct kmem_cache *s) |
5283 | { |
5284 | int err; |
5285 | const char *name; |
5286 | int unmergeable; |
5287 | |
5288 | if (slab_state < FULL) |
5289 | /* Defer until later */ |
5290 | return 0; |
5291 | |
5292 | unmergeable = slab_unmergeable(s); |
5293 | if (unmergeable) { |
5294 | /* |
5295 | * Slabcache can never be merged so we can use the name proper. |
5296 | * This is typically the case for debug situations. In that |
5297 | * case we can catch duplicate names easily. |
5298 | */ |
5299 | sysfs_remove_link(&slab_kset->kobj, s->name); |
5300 | name = s->name; |
5301 | } else { |
5302 | /* |
5303 | * Create a unique name for the slab as a target |
5304 | * for the symlinks. |
5305 | */ |
5306 | name = create_unique_id(s); |
5307 | } |
5308 | |
5309 | s->kobj.kset = slab_kset; |
5310 | err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name); |
5311 | if (err) { |
5312 | kobject_put(&s->kobj); |
5313 | return err; |
5314 | } |
5315 | |
5316 | err = sysfs_create_group(&s->kobj, &slab_attr_group); |
5317 | if (err) { |
5318 | kobject_del(&s->kobj); |
5319 | kobject_put(&s->kobj); |
5320 | return err; |
5321 | } |
5322 | kobject_uevent(&s->kobj, KOBJ_ADD); |
5323 | if (!unmergeable) { |
5324 | /* Setup first alias */ |
5325 | sysfs_slab_alias(s, s->name); |
5326 | kfree(name); |
5327 | } |
5328 | return 0; |
5329 | } |
5330 | |
5331 | static void sysfs_slab_remove(struct kmem_cache *s) |
5332 | { |
5333 | if (slab_state < FULL) |
5334 | /* |
5335 | * Sysfs has not been setup yet so no need to remove the |
5336 | * cache from sysfs. |
5337 | */ |
5338 | return; |
5339 | |
5340 | kobject_uevent(&s->kobj, KOBJ_REMOVE); |
5341 | kobject_del(&s->kobj); |
5342 | kobject_put(&s->kobj); |
5343 | } |
5344 | |
5345 | /* |
5346 | * Need to buffer aliases during bootup until sysfs becomes |
5347 | * available lest we lose that information. |
5348 | */ |
5349 | struct saved_alias { |
5350 | struct kmem_cache *s; |
5351 | const char *name; |
5352 | struct saved_alias *next; |
5353 | }; |
5354 | |
5355 | static struct saved_alias *alias_list; |
5356 | |
5357 | static int sysfs_slab_alias(struct kmem_cache *s, const char *name) |
5358 | { |
5359 | struct saved_alias *al; |
5360 | |
5361 | if (slab_state == FULL) { |
5362 | /* |
5363 | * If we have a leftover link then remove it. |
5364 | */ |
5365 | sysfs_remove_link(&slab_kset->kobj, name); |
5366 | return sysfs_create_link(&slab_kset->kobj, &s->kobj, name); |
5367 | } |
5368 | |
5369 | al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); |
5370 | if (!al) |
5371 | return -ENOMEM; |
5372 | |
5373 | al->s = s; |
5374 | al->name = name; |
5375 | al->next = alias_list; |
5376 | alias_list = al; |
5377 | return 0; |
5378 | } |
5379 | |
5380 | static int __init slab_sysfs_init(void) |
5381 | { |
5382 | struct kmem_cache *s; |
5383 | int err; |
5384 | |
5385 | mutex_lock(&slab_mutex); |
5386 | |
5387 | slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj); |
5388 | if (!slab_kset) { |
5389 | mutex_unlock(&slab_mutex); |
5390 | printk(KERN_ERR "Cannot register slab subsystem.\n"); |
5391 | return -ENOSYS; |
5392 | } |
5393 | |
5394 | slab_state = FULL; |
5395 | |
5396 | list_for_each_entry(s, &slab_caches, list) { |
5397 | err = sysfs_slab_add(s); |
5398 | if (err) |
5399 | printk(KERN_ERR "SLUB: Unable to add boot slab %s" |
5400 | " to sysfs\n", s->name); |
5401 | } |
5402 | |
5403 | while (alias_list) { |
5404 | struct saved_alias *al = alias_list; |
5405 | |
5406 | alias_list = alias_list->next; |
5407 | err = sysfs_slab_alias(al->s, al->name); |
5408 | if (err) |
5409 | printk(KERN_ERR "SLUB: Unable to add boot slab alias" |
5410 | " %s to sysfs\n", al->name); |
5411 | kfree(al); |
5412 | } |
5413 | |
5414 | mutex_unlock(&slab_mutex); |
5415 | resiliency_test(); |
5416 | return 0; |
5417 | } |
5418 | |
5419 | __initcall(slab_sysfs_init); |
5420 | #endif /* CONFIG_SYSFS */ |
5421 | |
5422 | /* |
5423 | * The /proc/slabinfo ABI |
5424 | */ |
5425 | #ifdef CONFIG_SLABINFO |
5426 | static void print_slabinfo_header(struct seq_file *m) |
5427 | { |
5428 | seq_puts(m, "slabinfo - version: 2.1\n"); |
5429 | seq_puts(m, "# name <active_objs> <num_objs> <object_size> " |
5430 | "<objperslab> <pagesperslab>"); |
5431 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
5432 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); |
5433 | seq_putc(m, '\n'); |
5434 | } |
5435 | |
5436 | static void *s_start(struct seq_file *m, loff_t *pos) |
5437 | { |
5438 | loff_t n = *pos; |
5439 | |
5440 | mutex_lock(&slab_mutex); |
5441 | if (!n) |
5442 | print_slabinfo_header(m); |
5443 | |
5444 | return seq_list_start(&slab_caches, *pos); |
5445 | } |
5446 | |
5447 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) |
5448 | { |
5449 | return seq_list_next(p, &slab_caches, pos); |
5450 | } |
5451 | |
5452 | static void s_stop(struct seq_file *m, void *p) |
5453 | { |
5454 | mutex_unlock(&slab_mutex); |
5455 | } |
5456 | |
5457 | static int s_show(struct seq_file *m, void *p) |
5458 | { |
5459 | unsigned long nr_partials = 0; |
5460 | unsigned long nr_slabs = 0; |
5461 | unsigned long nr_inuse = 0; |
5462 | unsigned long nr_objs = 0; |
5463 | unsigned long nr_free = 0; |
5464 | struct kmem_cache *s; |
5465 | int node; |
5466 | |
5467 | s = list_entry(p, struct kmem_cache, list); |
5468 | |
5469 | for_each_online_node(node) { |
5470 | struct kmem_cache_node *n = get_node(s, node); |
5471 | |
5472 | if (!n) |
5473 | continue; |
5474 | |
5475 | nr_partials += n->nr_partial; |
5476 | nr_slabs += atomic_long_read(&n->nr_slabs); |
5477 | nr_objs += atomic_long_read(&n->total_objects); |
5478 | nr_free += count_partial(n, count_free); |
5479 | } |
5480 | |
5481 | nr_inuse = nr_objs - nr_free; |
5482 | |
5483 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse, |
5484 | nr_objs, s->size, oo_objects(s->oo), |
5485 | (1 << oo_order(s->oo))); |
5486 | seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0); |
5487 | seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs, |
5488 | 0UL); |
5489 | seq_putc(m, '\n'); |
5490 | return 0; |
5491 | } |
5492 | |
5493 | static const struct seq_operations slabinfo_op = { |
5494 | .start = s_start, |
5495 | .next = s_next, |
5496 | .stop = s_stop, |
5497 | .show = s_show, |
5498 | }; |
5499 | |
5500 | static int slabinfo_open(struct inode *inode, struct file *file) |
5501 | { |
5502 | return seq_open(file, &slabinfo_op); |
5503 | } |
5504 | |
5505 | static const struct file_operations proc_slabinfo_operations = { |
5506 | .open = slabinfo_open, |
5507 | .read = seq_read, |
5508 | .llseek = seq_lseek, |
5509 | .release = seq_release, |
5510 | }; |
5511 | |
5512 | static int __init slab_proc_init(void) |
5513 | { |
5514 | proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations); |
5515 | return 0; |
5516 | } |
5517 | module_init(slab_proc_init); |
5518 | #endif /* CONFIG_SLABINFO */ |
5519 |
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javiroman/ks7010
jz-2.6.34
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9