Root/
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/notifier.h> |
22 | #include <linux/seq_file.h> |
23 | #include <linux/kmemcheck.h> |
24 | #include <linux/cpu.h> |
25 | #include <linux/cpuset.h> |
26 | #include <linux/mempolicy.h> |
27 | #include <linux/ctype.h> |
28 | #include <linux/debugobjects.h> |
29 | #include <linux/kallsyms.h> |
30 | #include <linux/memory.h> |
31 | #include <linux/math64.h> |
32 | #include <linux/fault-inject.h> |
33 | #include <linux/stacktrace.h> |
34 | #include <linux/prefetch.h> |
35 | #include <linux/memcontrol.h> |
36 | |
37 | #include <trace/events/kmem.h> |
38 | |
39 | #include "internal.h" |
40 | |
41 | /* |
42 | * Lock order: |
43 | * 1. slab_mutex (Global Mutex) |
44 | * 2. node->list_lock |
45 | * 3. slab_lock(page) (Only on some arches and for debugging) |
46 | * |
47 | * slab_mutex |
48 | * |
49 | * The role of the slab_mutex is to protect the list of all the slabs |
50 | * and to synchronize major metadata changes to slab cache structures. |
51 | * |
52 | * The slab_lock is only used for debugging and on arches that do not |
53 | * have the ability to do a cmpxchg_double. It only protects the second |
54 | * double word in the page struct. Meaning |
55 | * A. page->freelist -> List of object free in a page |
56 | * B. page->counters -> Counters of objects |
57 | * C. page->frozen -> frozen state |
58 | * |
59 | * If a slab is frozen then it is exempt from list management. It is not |
60 | * on any list. The processor that froze the slab is the one who can |
61 | * perform list operations on the page. Other processors may put objects |
62 | * onto the freelist but the processor that froze the slab is the only |
63 | * one that can retrieve the objects from the page's freelist. |
64 | * |
65 | * The list_lock protects the partial and full list on each node and |
66 | * the partial slab counter. If taken then no new slabs may be added or |
67 | * removed from the lists nor make the number of partial slabs be modified. |
68 | * (Note that the total number of slabs is an atomic value that may be |
69 | * modified without taking the list lock). |
70 | * |
71 | * The list_lock is a centralized lock and thus we avoid taking it as |
72 | * much as possible. As long as SLUB does not have to handle partial |
73 | * slabs, operations can continue without any centralized lock. F.e. |
74 | * allocating a long series of objects that fill up slabs does not require |
75 | * the list lock. |
76 | * Interrupts are disabled during allocation and deallocation in order to |
77 | * make the slab allocator safe to use in the context of an irq. In addition |
78 | * interrupts are disabled to ensure that the processor does not change |
79 | * while handling per_cpu slabs, due to kernel preemption. |
80 | * |
81 | * SLUB assigns one slab for allocation to each processor. |
82 | * Allocations only occur from these slabs called cpu slabs. |
83 | * |
84 | * Slabs with free elements are kept on a partial list and during regular |
85 | * operations no list for full slabs is used. If an object in a full slab is |
86 | * freed then the slab will show up again on the partial lists. |
87 | * We track full slabs for debugging purposes though because otherwise we |
88 | * cannot scan all objects. |
89 | * |
90 | * Slabs are freed when they become empty. Teardown and setup is |
91 | * minimal so we rely on the page allocators per cpu caches for |
92 | * fast frees and allocs. |
93 | * |
94 | * Overloading of page flags that are otherwise used for LRU management. |
95 | * |
96 | * PageActive The slab is frozen and exempt from list processing. |
97 | * This means that the slab is dedicated to a purpose |
98 | * such as satisfying allocations for a specific |
99 | * processor. Objects may be freed in the slab while |
100 | * it is frozen but slab_free will then skip the usual |
101 | * list operations. It is up to the processor holding |
102 | * the slab to integrate the slab into the slab lists |
103 | * when the slab is no longer needed. |
104 | * |
105 | * One use of this flag is to mark slabs that are |
106 | * used for allocations. Then such a slab becomes a cpu |
107 | * slab. The cpu slab may be equipped with an additional |
108 | * freelist that allows lockless access to |
109 | * free objects in addition to the regular freelist |
110 | * that requires the slab lock. |
111 | * |
112 | * PageError Slab requires special handling due to debug |
113 | * options set. This moves slab handling out of |
114 | * the fast path and disables lockless freelists. |
115 | */ |
116 | |
117 | static inline int kmem_cache_debug(struct kmem_cache *s) |
118 | { |
119 | #ifdef CONFIG_SLUB_DEBUG |
120 | return unlikely(s->flags & SLAB_DEBUG_FLAGS); |
121 | #else |
122 | return 0; |
123 | #endif |
124 | } |
125 | |
126 | static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s) |
127 | { |
128 | #ifdef CONFIG_SLUB_CPU_PARTIAL |
129 | return !kmem_cache_debug(s); |
130 | #else |
131 | return false; |
132 | #endif |
133 | } |
134 | |
135 | /* |
136 | * Issues still to be resolved: |
137 | * |
138 | * - Support PAGE_ALLOC_DEBUG. Should be easy to do. |
139 | * |
140 | * - Variable sizing of the per node arrays |
141 | */ |
142 | |
143 | /* Enable to test recovery from slab corruption on boot */ |
144 | #undef SLUB_RESILIENCY_TEST |
145 | |
146 | /* Enable to log cmpxchg failures */ |
147 | #undef SLUB_DEBUG_CMPXCHG |
148 | |
149 | /* |
150 | * Mininum number of partial slabs. These will be left on the partial |
151 | * lists even if they are empty. kmem_cache_shrink may reclaim them. |
152 | */ |
153 | #define MIN_PARTIAL 5 |
154 | |
155 | /* |
156 | * Maximum number of desirable partial slabs. |
157 | * The existence of more partial slabs makes kmem_cache_shrink |
158 | * sort the partial list by the number of objects in use. |
159 | */ |
160 | #define MAX_PARTIAL 10 |
161 | |
162 | #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \ |
163 | SLAB_POISON | SLAB_STORE_USER) |
164 | |
165 | /* |
166 | * Debugging flags that require metadata to be stored in the slab. These get |
167 | * disabled when slub_debug=O is used and a cache's min order increases with |
168 | * metadata. |
169 | */ |
170 | #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) |
171 | |
172 | /* |
173 | * Set of flags that will prevent slab merging |
174 | */ |
175 | #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ |
176 | SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ |
177 | SLAB_FAILSLAB) |
178 | |
179 | #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ |
180 | SLAB_CACHE_DMA | SLAB_NOTRACK) |
181 | |
182 | #define OO_SHIFT 16 |
183 | #define OO_MASK ((1 << OO_SHIFT) - 1) |
184 | #define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */ |
185 | |
186 | /* Internal SLUB flags */ |
187 | #define __OBJECT_POISON 0x80000000UL /* Poison object */ |
188 | #define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */ |
189 | |
190 | #ifdef CONFIG_SMP |
191 | static struct notifier_block slab_notifier; |
192 | #endif |
193 | |
194 | /* |
195 | * Tracking user of a slab. |
196 | */ |
197 | #define TRACK_ADDRS_COUNT 16 |
198 | struct track { |
199 | unsigned long addr; /* Called from address */ |
200 | #ifdef CONFIG_STACKTRACE |
201 | unsigned long addrs[TRACK_ADDRS_COUNT]; /* Called from address */ |
202 | #endif |
203 | int cpu; /* Was running on cpu */ |
204 | int pid; /* Pid context */ |
205 | unsigned long when; /* When did the operation occur */ |
206 | }; |
207 | |
208 | enum track_item { TRACK_ALLOC, TRACK_FREE }; |
209 | |
210 | #ifdef CONFIG_SYSFS |
211 | static int sysfs_slab_add(struct kmem_cache *); |
212 | static int sysfs_slab_alias(struct kmem_cache *, const char *); |
213 | static void memcg_propagate_slab_attrs(struct kmem_cache *s); |
214 | #else |
215 | static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; } |
216 | static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) |
217 | { return 0; } |
218 | static inline void memcg_propagate_slab_attrs(struct kmem_cache *s) { } |
219 | #endif |
220 | |
221 | static inline void stat(const struct kmem_cache *s, enum stat_item si) |
222 | { |
223 | #ifdef CONFIG_SLUB_STATS |
224 | /* |
225 | * The rmw is racy on a preemptible kernel but this is acceptable, so |
226 | * avoid this_cpu_add()'s irq-disable overhead. |
227 | */ |
228 | raw_cpu_inc(s->cpu_slab->stat[si]); |
229 | #endif |
230 | } |
231 | |
232 | /******************************************************************** |
233 | * Core slab cache functions |
234 | *******************************************************************/ |
235 | |
236 | static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) |
237 | { |
238 | return s->node[node]; |
239 | } |
240 | |
241 | /* Verify that a pointer has an address that is valid within a slab page */ |
242 | static inline int check_valid_pointer(struct kmem_cache *s, |
243 | struct page *page, const void *object) |
244 | { |
245 | void *base; |
246 | |
247 | if (!object) |
248 | return 1; |
249 | |
250 | base = page_address(page); |
251 | if (object < base || object >= base + page->objects * s->size || |
252 | (object - base) % s->size) { |
253 | return 0; |
254 | } |
255 | |
256 | return 1; |
257 | } |
258 | |
259 | static inline void *get_freepointer(struct kmem_cache *s, void *object) |
260 | { |
261 | return *(void **)(object + s->offset); |
262 | } |
263 | |
264 | static void prefetch_freepointer(const struct kmem_cache *s, void *object) |
265 | { |
266 | prefetch(object + s->offset); |
267 | } |
268 | |
269 | static inline void *get_freepointer_safe(struct kmem_cache *s, void *object) |
270 | { |
271 | void *p; |
272 | |
273 | #ifdef CONFIG_DEBUG_PAGEALLOC |
274 | probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p)); |
275 | #else |
276 | p = get_freepointer(s, object); |
277 | #endif |
278 | return p; |
279 | } |
280 | |
281 | static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) |
282 | { |
283 | *(void **)(object + s->offset) = fp; |
284 | } |
285 | |
286 | /* Loop over all objects in a slab */ |
287 | #define for_each_object(__p, __s, __addr, __objects) \ |
288 | for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\ |
289 | __p += (__s)->size) |
290 | |
291 | /* Determine object index from a given position */ |
292 | static inline int slab_index(void *p, struct kmem_cache *s, void *addr) |
293 | { |
294 | return (p - addr) / s->size; |
295 | } |
296 | |
297 | static inline size_t slab_ksize(const struct kmem_cache *s) |
298 | { |
299 | #ifdef CONFIG_SLUB_DEBUG |
300 | /* |
301 | * Debugging requires use of the padding between object |
302 | * and whatever may come after it. |
303 | */ |
304 | if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) |
305 | return s->object_size; |
306 | |
307 | #endif |
308 | /* |
309 | * If we have the need to store the freelist pointer |
310 | * back there or track user information then we can |
311 | * only use the space before that information. |
312 | */ |
313 | if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) |
314 | return s->inuse; |
315 | /* |
316 | * Else we can use all the padding etc for the allocation |
317 | */ |
318 | return s->size; |
319 | } |
320 | |
321 | static inline int order_objects(int order, unsigned long size, int reserved) |
322 | { |
323 | return ((PAGE_SIZE << order) - reserved) / size; |
324 | } |
325 | |
326 | static inline struct kmem_cache_order_objects oo_make(int order, |
327 | unsigned long size, int reserved) |
328 | { |
329 | struct kmem_cache_order_objects x = { |
330 | (order << OO_SHIFT) + order_objects(order, size, reserved) |
331 | }; |
332 | |
333 | return x; |
334 | } |
335 | |
336 | static inline int oo_order(struct kmem_cache_order_objects x) |
337 | { |
338 | return x.x >> OO_SHIFT; |
339 | } |
340 | |
341 | static inline int oo_objects(struct kmem_cache_order_objects x) |
342 | { |
343 | return x.x & OO_MASK; |
344 | } |
345 | |
346 | /* |
347 | * Per slab locking using the pagelock |
348 | */ |
349 | static __always_inline void slab_lock(struct page *page) |
350 | { |
351 | bit_spin_lock(PG_locked, &page->flags); |
352 | } |
353 | |
354 | static __always_inline void slab_unlock(struct page *page) |
355 | { |
356 | __bit_spin_unlock(PG_locked, &page->flags); |
357 | } |
358 | |
359 | static inline void set_page_slub_counters(struct page *page, unsigned long counters_new) |
360 | { |
361 | struct page tmp; |
362 | tmp.counters = counters_new; |
363 | /* |
364 | * page->counters can cover frozen/inuse/objects as well |
365 | * as page->_count. If we assign to ->counters directly |
366 | * we run the risk of losing updates to page->_count, so |
367 | * be careful and only assign to the fields we need. |
368 | */ |
369 | page->frozen = tmp.frozen; |
370 | page->inuse = tmp.inuse; |
371 | page->objects = tmp.objects; |
372 | } |
373 | |
374 | /* Interrupts must be disabled (for the fallback code to work right) */ |
375 | static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page, |
376 | void *freelist_old, unsigned long counters_old, |
377 | void *freelist_new, unsigned long counters_new, |
378 | const char *n) |
379 | { |
380 | VM_BUG_ON(!irqs_disabled()); |
381 | #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ |
382 | defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) |
383 | if (s->flags & __CMPXCHG_DOUBLE) { |
384 | if (cmpxchg_double(&page->freelist, &page->counters, |
385 | freelist_old, counters_old, |
386 | freelist_new, counters_new)) |
387 | return 1; |
388 | } else |
389 | #endif |
390 | { |
391 | slab_lock(page); |
392 | if (page->freelist == freelist_old && |
393 | page->counters == counters_old) { |
394 | page->freelist = freelist_new; |
395 | set_page_slub_counters(page, counters_new); |
396 | slab_unlock(page); |
397 | return 1; |
398 | } |
399 | slab_unlock(page); |
400 | } |
401 | |
402 | cpu_relax(); |
403 | stat(s, CMPXCHG_DOUBLE_FAIL); |
404 | |
405 | #ifdef SLUB_DEBUG_CMPXCHG |
406 | printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name); |
407 | #endif |
408 | |
409 | return 0; |
410 | } |
411 | |
412 | static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page, |
413 | void *freelist_old, unsigned long counters_old, |
414 | void *freelist_new, unsigned long counters_new, |
415 | const char *n) |
416 | { |
417 | #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ |
418 | defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) |
419 | if (s->flags & __CMPXCHG_DOUBLE) { |
420 | if (cmpxchg_double(&page->freelist, &page->counters, |
421 | freelist_old, counters_old, |
422 | freelist_new, counters_new)) |
423 | return 1; |
424 | } else |
425 | #endif |
426 | { |
427 | unsigned long flags; |
428 | |
429 | local_irq_save(flags); |
430 | slab_lock(page); |
431 | if (page->freelist == freelist_old && |
432 | page->counters == counters_old) { |
433 | page->freelist = freelist_new; |
434 | set_page_slub_counters(page, counters_new); |
435 | slab_unlock(page); |
436 | local_irq_restore(flags); |
437 | return 1; |
438 | } |
439 | slab_unlock(page); |
440 | local_irq_restore(flags); |
441 | } |
442 | |
443 | cpu_relax(); |
444 | stat(s, CMPXCHG_DOUBLE_FAIL); |
445 | |
446 | #ifdef SLUB_DEBUG_CMPXCHG |
447 | printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name); |
448 | #endif |
449 | |
450 | return 0; |
451 | } |
452 | |
453 | #ifdef CONFIG_SLUB_DEBUG |
454 | /* |
455 | * Determine a map of object in use on a page. |
456 | * |
457 | * Node listlock must be held to guarantee that the page does |
458 | * not vanish from under us. |
459 | */ |
460 | static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map) |
461 | { |
462 | void *p; |
463 | void *addr = page_address(page); |
464 | |
465 | for (p = page->freelist; p; p = get_freepointer(s, p)) |
466 | set_bit(slab_index(p, s, addr), map); |
467 | } |
468 | |
469 | /* |
470 | * Debug settings: |
471 | */ |
472 | #ifdef CONFIG_SLUB_DEBUG_ON |
473 | static int slub_debug = DEBUG_DEFAULT_FLAGS; |
474 | #else |
475 | static int slub_debug; |
476 | #endif |
477 | |
478 | static char *slub_debug_slabs; |
479 | static int disable_higher_order_debug; |
480 | |
481 | /* |
482 | * Object debugging |
483 | */ |
484 | static void print_section(char *text, u8 *addr, unsigned int length) |
485 | { |
486 | print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr, |
487 | length, 1); |
488 | } |
489 | |
490 | static struct track *get_track(struct kmem_cache *s, void *object, |
491 | enum track_item alloc) |
492 | { |
493 | struct track *p; |
494 | |
495 | if (s->offset) |
496 | p = object + s->offset + sizeof(void *); |
497 | else |
498 | p = object + s->inuse; |
499 | |
500 | return p + alloc; |
501 | } |
502 | |
503 | static void set_track(struct kmem_cache *s, void *object, |
504 | enum track_item alloc, unsigned long addr) |
505 | { |
506 | struct track *p = get_track(s, object, alloc); |
507 | |
508 | if (addr) { |
509 | #ifdef CONFIG_STACKTRACE |
510 | struct stack_trace trace; |
511 | int i; |
512 | |
513 | trace.nr_entries = 0; |
514 | trace.max_entries = TRACK_ADDRS_COUNT; |
515 | trace.entries = p->addrs; |
516 | trace.skip = 3; |
517 | save_stack_trace(&trace); |
518 | |
519 | /* See rant in lockdep.c */ |
520 | if (trace.nr_entries != 0 && |
521 | trace.entries[trace.nr_entries - 1] == ULONG_MAX) |
522 | trace.nr_entries--; |
523 | |
524 | for (i = trace.nr_entries; i < TRACK_ADDRS_COUNT; i++) |
525 | p->addrs[i] = 0; |
526 | #endif |
527 | p->addr = addr; |
528 | p->cpu = smp_processor_id(); |
529 | p->pid = current->pid; |
530 | p->when = jiffies; |
531 | } else |
532 | memset(p, 0, sizeof(struct track)); |
533 | } |
534 | |
535 | static void init_tracking(struct kmem_cache *s, void *object) |
536 | { |
537 | if (!(s->flags & SLAB_STORE_USER)) |
538 | return; |
539 | |
540 | set_track(s, object, TRACK_FREE, 0UL); |
541 | set_track(s, object, TRACK_ALLOC, 0UL); |
542 | } |
543 | |
544 | static void print_track(const char *s, struct track *t) |
545 | { |
546 | if (!t->addr) |
547 | return; |
548 | |
549 | printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n", |
550 | s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid); |
551 | #ifdef CONFIG_STACKTRACE |
552 | { |
553 | int i; |
554 | for (i = 0; i < TRACK_ADDRS_COUNT; i++) |
555 | if (t->addrs[i]) |
556 | printk(KERN_ERR "\t%pS\n", (void *)t->addrs[i]); |
557 | else |
558 | break; |
559 | } |
560 | #endif |
561 | } |
562 | |
563 | static void print_tracking(struct kmem_cache *s, void *object) |
564 | { |
565 | if (!(s->flags & SLAB_STORE_USER)) |
566 | return; |
567 | |
568 | print_track("Allocated", get_track(s, object, TRACK_ALLOC)); |
569 | print_track("Freed", get_track(s, object, TRACK_FREE)); |
570 | } |
571 | |
572 | static void print_page_info(struct page *page) |
573 | { |
574 | printk(KERN_ERR |
575 | "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n", |
576 | page, page->objects, page->inuse, page->freelist, page->flags); |
577 | |
578 | } |
579 | |
580 | static void slab_bug(struct kmem_cache *s, char *fmt, ...) |
581 | { |
582 | va_list args; |
583 | char buf[100]; |
584 | |
585 | va_start(args, fmt); |
586 | vsnprintf(buf, sizeof(buf), fmt, args); |
587 | va_end(args); |
588 | printk(KERN_ERR "========================================" |
589 | "=====================================\n"); |
590 | printk(KERN_ERR "BUG %s (%s): %s\n", s->name, print_tainted(), buf); |
591 | printk(KERN_ERR "----------------------------------------" |
592 | "-------------------------------------\n\n"); |
593 | |
594 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
595 | } |
596 | |
597 | static void slab_fix(struct kmem_cache *s, char *fmt, ...) |
598 | { |
599 | va_list args; |
600 | char buf[100]; |
601 | |
602 | va_start(args, fmt); |
603 | vsnprintf(buf, sizeof(buf), fmt, args); |
604 | va_end(args); |
605 | printk(KERN_ERR "FIX %s: %s\n", s->name, buf); |
606 | } |
607 | |
608 | static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p) |
609 | { |
610 | unsigned int off; /* Offset of last byte */ |
611 | u8 *addr = page_address(page); |
612 | |
613 | print_tracking(s, p); |
614 | |
615 | print_page_info(page); |
616 | |
617 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n", |
618 | p, p - addr, get_freepointer(s, p)); |
619 | |
620 | if (p > addr + 16) |
621 | print_section("Bytes b4 ", p - 16, 16); |
622 | |
623 | print_section("Object ", p, min_t(unsigned long, s->object_size, |
624 | PAGE_SIZE)); |
625 | if (s->flags & SLAB_RED_ZONE) |
626 | print_section("Redzone ", p + s->object_size, |
627 | s->inuse - s->object_size); |
628 | |
629 | if (s->offset) |
630 | off = s->offset + sizeof(void *); |
631 | else |
632 | off = s->inuse; |
633 | |
634 | if (s->flags & SLAB_STORE_USER) |
635 | off += 2 * sizeof(struct track); |
636 | |
637 | if (off != s->size) |
638 | /* Beginning of the filler is the free pointer */ |
639 | print_section("Padding ", p + off, s->size - off); |
640 | |
641 | dump_stack(); |
642 | } |
643 | |
644 | static void object_err(struct kmem_cache *s, struct page *page, |
645 | u8 *object, char *reason) |
646 | { |
647 | slab_bug(s, "%s", reason); |
648 | print_trailer(s, page, object); |
649 | } |
650 | |
651 | static void slab_err(struct kmem_cache *s, struct page *page, |
652 | const char *fmt, ...) |
653 | { |
654 | va_list args; |
655 | char buf[100]; |
656 | |
657 | va_start(args, fmt); |
658 | vsnprintf(buf, sizeof(buf), fmt, args); |
659 | va_end(args); |
660 | slab_bug(s, "%s", buf); |
661 | print_page_info(page); |
662 | dump_stack(); |
663 | } |
664 | |
665 | static void init_object(struct kmem_cache *s, void *object, u8 val) |
666 | { |
667 | u8 *p = object; |
668 | |
669 | if (s->flags & __OBJECT_POISON) { |
670 | memset(p, POISON_FREE, s->object_size - 1); |
671 | p[s->object_size - 1] = POISON_END; |
672 | } |
673 | |
674 | if (s->flags & SLAB_RED_ZONE) |
675 | memset(p + s->object_size, val, s->inuse - s->object_size); |
676 | } |
677 | |
678 | static void restore_bytes(struct kmem_cache *s, char *message, u8 data, |
679 | void *from, void *to) |
680 | { |
681 | slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data); |
682 | memset(from, data, to - from); |
683 | } |
684 | |
685 | static int check_bytes_and_report(struct kmem_cache *s, struct page *page, |
686 | u8 *object, char *what, |
687 | u8 *start, unsigned int value, unsigned int bytes) |
688 | { |
689 | u8 *fault; |
690 | u8 *end; |
691 | |
692 | fault = memchr_inv(start, value, bytes); |
693 | if (!fault) |
694 | return 1; |
695 | |
696 | end = start + bytes; |
697 | while (end > fault && end[-1] == value) |
698 | end--; |
699 | |
700 | slab_bug(s, "%s overwritten", what); |
701 | printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n", |
702 | fault, end - 1, fault[0], value); |
703 | print_trailer(s, page, object); |
704 | |
705 | restore_bytes(s, what, value, fault, end); |
706 | return 0; |
707 | } |
708 | |
709 | /* |
710 | * Object layout: |
711 | * |
712 | * object address |
713 | * Bytes of the object to be managed. |
714 | * If the freepointer may overlay the object then the free |
715 | * pointer is the first word of the object. |
716 | * |
717 | * Poisoning uses 0x6b (POISON_FREE) and the last byte is |
718 | * 0xa5 (POISON_END) |
719 | * |
720 | * object + s->object_size |
721 | * Padding to reach word boundary. This is also used for Redzoning. |
722 | * Padding is extended by another word if Redzoning is enabled and |
723 | * object_size == inuse. |
724 | * |
725 | * We fill with 0xbb (RED_INACTIVE) for inactive objects and with |
726 | * 0xcc (RED_ACTIVE) for objects in use. |
727 | * |
728 | * object + s->inuse |
729 | * Meta data starts here. |
730 | * |
731 | * A. Free pointer (if we cannot overwrite object on free) |
732 | * B. Tracking data for SLAB_STORE_USER |
733 | * C. Padding to reach required alignment boundary or at mininum |
734 | * one word if debugging is on to be able to detect writes |
735 | * before the word boundary. |
736 | * |
737 | * Padding is done using 0x5a (POISON_INUSE) |
738 | * |
739 | * object + s->size |
740 | * Nothing is used beyond s->size. |
741 | * |
742 | * If slabcaches are merged then the object_size and inuse boundaries are mostly |
743 | * ignored. And therefore no slab options that rely on these boundaries |
744 | * may be used with merged slabcaches. |
745 | */ |
746 | |
747 | static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p) |
748 | { |
749 | unsigned long off = s->inuse; /* The end of info */ |
750 | |
751 | if (s->offset) |
752 | /* Freepointer is placed after the object. */ |
753 | off += sizeof(void *); |
754 | |
755 | if (s->flags & SLAB_STORE_USER) |
756 | /* We also have user information there */ |
757 | off += 2 * sizeof(struct track); |
758 | |
759 | if (s->size == off) |
760 | return 1; |
761 | |
762 | return check_bytes_and_report(s, page, p, "Object padding", |
763 | p + off, POISON_INUSE, s->size - off); |
764 | } |
765 | |
766 | /* Check the pad bytes at the end of a slab page */ |
767 | static int slab_pad_check(struct kmem_cache *s, struct page *page) |
768 | { |
769 | u8 *start; |
770 | u8 *fault; |
771 | u8 *end; |
772 | int length; |
773 | int remainder; |
774 | |
775 | if (!(s->flags & SLAB_POISON)) |
776 | return 1; |
777 | |
778 | start = page_address(page); |
779 | length = (PAGE_SIZE << compound_order(page)) - s->reserved; |
780 | end = start + length; |
781 | remainder = length % s->size; |
782 | if (!remainder) |
783 | return 1; |
784 | |
785 | fault = memchr_inv(end - remainder, POISON_INUSE, remainder); |
786 | if (!fault) |
787 | return 1; |
788 | while (end > fault && end[-1] == POISON_INUSE) |
789 | end--; |
790 | |
791 | slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1); |
792 | print_section("Padding ", end - remainder, remainder); |
793 | |
794 | restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end); |
795 | return 0; |
796 | } |
797 | |
798 | static int check_object(struct kmem_cache *s, struct page *page, |
799 | void *object, u8 val) |
800 | { |
801 | u8 *p = object; |
802 | u8 *endobject = object + s->object_size; |
803 | |
804 | if (s->flags & SLAB_RED_ZONE) { |
805 | if (!check_bytes_and_report(s, page, object, "Redzone", |
806 | endobject, val, s->inuse - s->object_size)) |
807 | return 0; |
808 | } else { |
809 | if ((s->flags & SLAB_POISON) && s->object_size < s->inuse) { |
810 | check_bytes_and_report(s, page, p, "Alignment padding", |
811 | endobject, POISON_INUSE, |
812 | s->inuse - s->object_size); |
813 | } |
814 | } |
815 | |
816 | if (s->flags & SLAB_POISON) { |
817 | if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) && |
818 | (!check_bytes_and_report(s, page, p, "Poison", p, |
819 | POISON_FREE, s->object_size - 1) || |
820 | !check_bytes_and_report(s, page, p, "Poison", |
821 | p + s->object_size - 1, POISON_END, 1))) |
822 | return 0; |
823 | /* |
824 | * check_pad_bytes cleans up on its own. |
825 | */ |
826 | check_pad_bytes(s, page, p); |
827 | } |
828 | |
829 | if (!s->offset && val == SLUB_RED_ACTIVE) |
830 | /* |
831 | * Object and freepointer overlap. Cannot check |
832 | * freepointer while object is allocated. |
833 | */ |
834 | return 1; |
835 | |
836 | /* Check free pointer validity */ |
837 | if (!check_valid_pointer(s, page, get_freepointer(s, p))) { |
838 | object_err(s, page, p, "Freepointer corrupt"); |
839 | /* |
840 | * No choice but to zap it and thus lose the remainder |
841 | * of the free objects in this slab. May cause |
842 | * another error because the object count is now wrong. |
843 | */ |
844 | set_freepointer(s, p, NULL); |
845 | return 0; |
846 | } |
847 | return 1; |
848 | } |
849 | |
850 | static int check_slab(struct kmem_cache *s, struct page *page) |
851 | { |
852 | int maxobj; |
853 | |
854 | VM_BUG_ON(!irqs_disabled()); |
855 | |
856 | if (!PageSlab(page)) { |
857 | slab_err(s, page, "Not a valid slab page"); |
858 | return 0; |
859 | } |
860 | |
861 | maxobj = order_objects(compound_order(page), s->size, s->reserved); |
862 | if (page->objects > maxobj) { |
863 | slab_err(s, page, "objects %u > max %u", |
864 | s->name, page->objects, maxobj); |
865 | return 0; |
866 | } |
867 | if (page->inuse > page->objects) { |
868 | slab_err(s, page, "inuse %u > max %u", |
869 | s->name, page->inuse, page->objects); |
870 | return 0; |
871 | } |
872 | /* Slab_pad_check fixes things up after itself */ |
873 | slab_pad_check(s, page); |
874 | return 1; |
875 | } |
876 | |
877 | /* |
878 | * Determine if a certain object on a page is on the freelist. Must hold the |
879 | * slab lock to guarantee that the chains are in a consistent state. |
880 | */ |
881 | static int on_freelist(struct kmem_cache *s, struct page *page, void *search) |
882 | { |
883 | int nr = 0; |
884 | void *fp; |
885 | void *object = NULL; |
886 | unsigned long max_objects; |
887 | |
888 | fp = page->freelist; |
889 | while (fp && nr <= page->objects) { |
890 | if (fp == search) |
891 | return 1; |
892 | if (!check_valid_pointer(s, page, fp)) { |
893 | if (object) { |
894 | object_err(s, page, object, |
895 | "Freechain corrupt"); |
896 | set_freepointer(s, object, NULL); |
897 | } else { |
898 | slab_err(s, page, "Freepointer corrupt"); |
899 | page->freelist = NULL; |
900 | page->inuse = page->objects; |
901 | slab_fix(s, "Freelist cleared"); |
902 | return 0; |
903 | } |
904 | break; |
905 | } |
906 | object = fp; |
907 | fp = get_freepointer(s, object); |
908 | nr++; |
909 | } |
910 | |
911 | max_objects = order_objects(compound_order(page), s->size, s->reserved); |
912 | if (max_objects > MAX_OBJS_PER_PAGE) |
913 | max_objects = MAX_OBJS_PER_PAGE; |
914 | |
915 | if (page->objects != max_objects) { |
916 | slab_err(s, page, "Wrong number of objects. Found %d but " |
917 | "should be %d", page->objects, max_objects); |
918 | page->objects = max_objects; |
919 | slab_fix(s, "Number of objects adjusted."); |
920 | } |
921 | if (page->inuse != page->objects - nr) { |
922 | slab_err(s, page, "Wrong object count. Counter is %d but " |
923 | "counted were %d", page->inuse, page->objects - nr); |
924 | page->inuse = page->objects - nr; |
925 | slab_fix(s, "Object count adjusted."); |
926 | } |
927 | return search == NULL; |
928 | } |
929 | |
930 | static void trace(struct kmem_cache *s, struct page *page, void *object, |
931 | int alloc) |
932 | { |
933 | if (s->flags & SLAB_TRACE) { |
934 | printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n", |
935 | s->name, |
936 | alloc ? "alloc" : "free", |
937 | object, page->inuse, |
938 | page->freelist); |
939 | |
940 | if (!alloc) |
941 | print_section("Object ", (void *)object, |
942 | s->object_size); |
943 | |
944 | dump_stack(); |
945 | } |
946 | } |
947 | |
948 | /* |
949 | * Hooks for other subsystems that check memory allocations. In a typical |
950 | * production configuration these hooks all should produce no code at all. |
951 | */ |
952 | static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags) |
953 | { |
954 | kmemleak_alloc(ptr, size, 1, flags); |
955 | } |
956 | |
957 | static inline void kfree_hook(const void *x) |
958 | { |
959 | kmemleak_free(x); |
960 | } |
961 | |
962 | static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) |
963 | { |
964 | flags &= gfp_allowed_mask; |
965 | lockdep_trace_alloc(flags); |
966 | might_sleep_if(flags & __GFP_WAIT); |
967 | |
968 | return should_failslab(s->object_size, flags, s->flags); |
969 | } |
970 | |
971 | static inline void slab_post_alloc_hook(struct kmem_cache *s, |
972 | gfp_t flags, void *object) |
973 | { |
974 | flags &= gfp_allowed_mask; |
975 | kmemcheck_slab_alloc(s, flags, object, slab_ksize(s)); |
976 | kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, flags); |
977 | } |
978 | |
979 | static inline void slab_free_hook(struct kmem_cache *s, void *x) |
980 | { |
981 | kmemleak_free_recursive(x, s->flags); |
982 | |
983 | /* |
984 | * Trouble is that we may no longer disable interrupts in the fast path |
985 | * So in order to make the debug calls that expect irqs to be |
986 | * disabled we need to disable interrupts temporarily. |
987 | */ |
988 | #if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP) |
989 | { |
990 | unsigned long flags; |
991 | |
992 | local_irq_save(flags); |
993 | kmemcheck_slab_free(s, x, s->object_size); |
994 | debug_check_no_locks_freed(x, s->object_size); |
995 | local_irq_restore(flags); |
996 | } |
997 | #endif |
998 | if (!(s->flags & SLAB_DEBUG_OBJECTS)) |
999 | debug_check_no_obj_freed(x, s->object_size); |
1000 | } |
1001 | |
1002 | /* |
1003 | * Tracking of fully allocated slabs for debugging purposes. |
1004 | */ |
1005 | static void add_full(struct kmem_cache *s, |
1006 | struct kmem_cache_node *n, struct page *page) |
1007 | { |
1008 | if (!(s->flags & SLAB_STORE_USER)) |
1009 | return; |
1010 | |
1011 | lockdep_assert_held(&n->list_lock); |
1012 | list_add(&page->lru, &n->full); |
1013 | } |
1014 | |
1015 | static void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, struct page *page) |
1016 | { |
1017 | if (!(s->flags & SLAB_STORE_USER)) |
1018 | return; |
1019 | |
1020 | lockdep_assert_held(&n->list_lock); |
1021 | list_del(&page->lru); |
1022 | } |
1023 | |
1024 | /* Tracking of the number of slabs for debugging purposes */ |
1025 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) |
1026 | { |
1027 | struct kmem_cache_node *n = get_node(s, node); |
1028 | |
1029 | return atomic_long_read(&n->nr_slabs); |
1030 | } |
1031 | |
1032 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) |
1033 | { |
1034 | return atomic_long_read(&n->nr_slabs); |
1035 | } |
1036 | |
1037 | static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects) |
1038 | { |
1039 | struct kmem_cache_node *n = get_node(s, node); |
1040 | |
1041 | /* |
1042 | * May be called early in order to allocate a slab for the |
1043 | * kmem_cache_node structure. Solve the chicken-egg |
1044 | * dilemma by deferring the increment of the count during |
1045 | * bootstrap (see early_kmem_cache_node_alloc). |
1046 | */ |
1047 | if (likely(n)) { |
1048 | atomic_long_inc(&n->nr_slabs); |
1049 | atomic_long_add(objects, &n->total_objects); |
1050 | } |
1051 | } |
1052 | static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects) |
1053 | { |
1054 | struct kmem_cache_node *n = get_node(s, node); |
1055 | |
1056 | atomic_long_dec(&n->nr_slabs); |
1057 | atomic_long_sub(objects, &n->total_objects); |
1058 | } |
1059 | |
1060 | /* Object debug checks for alloc/free paths */ |
1061 | static void setup_object_debug(struct kmem_cache *s, struct page *page, |
1062 | void *object) |
1063 | { |
1064 | if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))) |
1065 | return; |
1066 | |
1067 | init_object(s, object, SLUB_RED_INACTIVE); |
1068 | init_tracking(s, object); |
1069 | } |
1070 | |
1071 | static noinline int alloc_debug_processing(struct kmem_cache *s, |
1072 | struct page *page, |
1073 | void *object, unsigned long addr) |
1074 | { |
1075 | if (!check_slab(s, page)) |
1076 | goto bad; |
1077 | |
1078 | if (!check_valid_pointer(s, page, object)) { |
1079 | object_err(s, page, object, "Freelist Pointer check fails"); |
1080 | goto bad; |
1081 | } |
1082 | |
1083 | if (!check_object(s, page, object, SLUB_RED_INACTIVE)) |
1084 | goto bad; |
1085 | |
1086 | /* Success perform special debug activities for allocs */ |
1087 | if (s->flags & SLAB_STORE_USER) |
1088 | set_track(s, object, TRACK_ALLOC, addr); |
1089 | trace(s, page, object, 1); |
1090 | init_object(s, object, SLUB_RED_ACTIVE); |
1091 | return 1; |
1092 | |
1093 | bad: |
1094 | if (PageSlab(page)) { |
1095 | /* |
1096 | * If this is a slab page then lets do the best we can |
1097 | * to avoid issues in the future. Marking all objects |
1098 | * as used avoids touching the remaining objects. |
1099 | */ |
1100 | slab_fix(s, "Marking all objects used"); |
1101 | page->inuse = page->objects; |
1102 | page->freelist = NULL; |
1103 | } |
1104 | return 0; |
1105 | } |
1106 | |
1107 | static noinline struct kmem_cache_node *free_debug_processing( |
1108 | struct kmem_cache *s, struct page *page, void *object, |
1109 | unsigned long addr, unsigned long *flags) |
1110 | { |
1111 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); |
1112 | |
1113 | spin_lock_irqsave(&n->list_lock, *flags); |
1114 | slab_lock(page); |
1115 | |
1116 | if (!check_slab(s, page)) |
1117 | goto fail; |
1118 | |
1119 | if (!check_valid_pointer(s, page, object)) { |
1120 | slab_err(s, page, "Invalid object pointer 0x%p", object); |
1121 | goto fail; |
1122 | } |
1123 | |
1124 | if (on_freelist(s, page, object)) { |
1125 | object_err(s, page, object, "Object already free"); |
1126 | goto fail; |
1127 | } |
1128 | |
1129 | if (!check_object(s, page, object, SLUB_RED_ACTIVE)) |
1130 | goto out; |
1131 | |
1132 | if (unlikely(s != page->slab_cache)) { |
1133 | if (!PageSlab(page)) { |
1134 | slab_err(s, page, "Attempt to free object(0x%p) " |
1135 | "outside of slab", object); |
1136 | } else if (!page->slab_cache) { |
1137 | printk(KERN_ERR |
1138 | "SLUB <none>: no slab for object 0x%p.\n", |
1139 | object); |
1140 | dump_stack(); |
1141 | } else |
1142 | object_err(s, page, object, |
1143 | "page slab pointer corrupt."); |
1144 | goto fail; |
1145 | } |
1146 | |
1147 | if (s->flags & SLAB_STORE_USER) |
1148 | set_track(s, object, TRACK_FREE, addr); |
1149 | trace(s, page, object, 0); |
1150 | init_object(s, object, SLUB_RED_INACTIVE); |
1151 | out: |
1152 | slab_unlock(page); |
1153 | /* |
1154 | * Keep node_lock to preserve integrity |
1155 | * until the object is actually freed |
1156 | */ |
1157 | return n; |
1158 | |
1159 | fail: |
1160 | slab_unlock(page); |
1161 | spin_unlock_irqrestore(&n->list_lock, *flags); |
1162 | slab_fix(s, "Object at 0x%p not freed", object); |
1163 | return NULL; |
1164 | } |
1165 | |
1166 | static int __init setup_slub_debug(char *str) |
1167 | { |
1168 | slub_debug = DEBUG_DEFAULT_FLAGS; |
1169 | if (*str++ != '=' || !*str) |
1170 | /* |
1171 | * No options specified. Switch on full debugging. |
1172 | */ |
1173 | goto out; |
1174 | |
1175 | if (*str == ',') |
1176 | /* |
1177 | * No options but restriction on slabs. This means full |
1178 | * debugging for slabs matching a pattern. |
1179 | */ |
1180 | goto check_slabs; |
1181 | |
1182 | if (tolower(*str) == 'o') { |
1183 | /* |
1184 | * Avoid enabling debugging on caches if its minimum order |
1185 | * would increase as a result. |
1186 | */ |
1187 | disable_higher_order_debug = 1; |
1188 | goto out; |
1189 | } |
1190 | |
1191 | slub_debug = 0; |
1192 | if (*str == '-') |
1193 | /* |
1194 | * Switch off all debugging measures. |
1195 | */ |
1196 | goto out; |
1197 | |
1198 | /* |
1199 | * Determine which debug features should be switched on |
1200 | */ |
1201 | for (; *str && *str != ','; str++) { |
1202 | switch (tolower(*str)) { |
1203 | case 'f': |
1204 | slub_debug |= SLAB_DEBUG_FREE; |
1205 | break; |
1206 | case 'z': |
1207 | slub_debug |= SLAB_RED_ZONE; |
1208 | break; |
1209 | case 'p': |
1210 | slub_debug |= SLAB_POISON; |
1211 | break; |
1212 | case 'u': |
1213 | slub_debug |= SLAB_STORE_USER; |
1214 | break; |
1215 | case 't': |
1216 | slub_debug |= SLAB_TRACE; |
1217 | break; |
1218 | case 'a': |
1219 | slub_debug |= SLAB_FAILSLAB; |
1220 | break; |
1221 | default: |
1222 | printk(KERN_ERR "slub_debug option '%c' " |
1223 | "unknown. skipped\n", *str); |
1224 | } |
1225 | } |
1226 | |
1227 | check_slabs: |
1228 | if (*str == ',') |
1229 | slub_debug_slabs = str + 1; |
1230 | out: |
1231 | return 1; |
1232 | } |
1233 | |
1234 | __setup("slub_debug", setup_slub_debug); |
1235 | |
1236 | static unsigned long kmem_cache_flags(unsigned long object_size, |
1237 | unsigned long flags, const char *name, |
1238 | void (*ctor)(void *)) |
1239 | { |
1240 | /* |
1241 | * Enable debugging if selected on the kernel commandline. |
1242 | */ |
1243 | if (slub_debug && (!slub_debug_slabs || (name && |
1244 | !strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))) |
1245 | flags |= slub_debug; |
1246 | |
1247 | return flags; |
1248 | } |
1249 | #else |
1250 | static inline void setup_object_debug(struct kmem_cache *s, |
1251 | struct page *page, void *object) {} |
1252 | |
1253 | static inline int alloc_debug_processing(struct kmem_cache *s, |
1254 | struct page *page, void *object, unsigned long addr) { return 0; } |
1255 | |
1256 | static inline struct kmem_cache_node *free_debug_processing( |
1257 | struct kmem_cache *s, struct page *page, void *object, |
1258 | unsigned long addr, unsigned long *flags) { return NULL; } |
1259 | |
1260 | static inline int slab_pad_check(struct kmem_cache *s, struct page *page) |
1261 | { return 1; } |
1262 | static inline int check_object(struct kmem_cache *s, struct page *page, |
1263 | void *object, u8 val) { return 1; } |
1264 | static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n, |
1265 | struct page *page) {} |
1266 | static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, |
1267 | struct page *page) {} |
1268 | static inline unsigned long kmem_cache_flags(unsigned long object_size, |
1269 | unsigned long flags, const char *name, |
1270 | void (*ctor)(void *)) |
1271 | { |
1272 | return flags; |
1273 | } |
1274 | #define slub_debug 0 |
1275 | |
1276 | #define disable_higher_order_debug 0 |
1277 | |
1278 | static inline unsigned long slabs_node(struct kmem_cache *s, int node) |
1279 | { return 0; } |
1280 | static inline unsigned long node_nr_slabs(struct kmem_cache_node *n) |
1281 | { return 0; } |
1282 | static inline void inc_slabs_node(struct kmem_cache *s, int node, |
1283 | int objects) {} |
1284 | static inline void dec_slabs_node(struct kmem_cache *s, int node, |
1285 | int objects) {} |
1286 | |
1287 | static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags) |
1288 | { |
1289 | kmemleak_alloc(ptr, size, 1, flags); |
1290 | } |
1291 | |
1292 | static inline void kfree_hook(const void *x) |
1293 | { |
1294 | kmemleak_free(x); |
1295 | } |
1296 | |
1297 | static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) |
1298 | { return 0; } |
1299 | |
1300 | static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, |
1301 | void *object) |
1302 | { |
1303 | kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, |
1304 | flags & gfp_allowed_mask); |
1305 | } |
1306 | |
1307 | static inline void slab_free_hook(struct kmem_cache *s, void *x) |
1308 | { |
1309 | kmemleak_free_recursive(x, s->flags); |
1310 | } |
1311 | |
1312 | #endif /* CONFIG_SLUB_DEBUG */ |
1313 | |
1314 | /* |
1315 | * Slab allocation and freeing |
1316 | */ |
1317 | static inline struct page *alloc_slab_page(gfp_t flags, int node, |
1318 | struct kmem_cache_order_objects oo) |
1319 | { |
1320 | int order = oo_order(oo); |
1321 | |
1322 | flags |= __GFP_NOTRACK; |
1323 | |
1324 | if (node == NUMA_NO_NODE) |
1325 | return alloc_pages(flags, order); |
1326 | else |
1327 | return alloc_pages_exact_node(node, flags, order); |
1328 | } |
1329 | |
1330 | static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) |
1331 | { |
1332 | struct page *page; |
1333 | struct kmem_cache_order_objects oo = s->oo; |
1334 | gfp_t alloc_gfp; |
1335 | |
1336 | flags &= gfp_allowed_mask; |
1337 | |
1338 | if (flags & __GFP_WAIT) |
1339 | local_irq_enable(); |
1340 | |
1341 | flags |= s->allocflags; |
1342 | |
1343 | /* |
1344 | * Let the initial higher-order allocation fail under memory pressure |
1345 | * so we fall-back to the minimum order allocation. |
1346 | */ |
1347 | alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL; |
1348 | |
1349 | page = alloc_slab_page(alloc_gfp, node, oo); |
1350 | if (unlikely(!page)) { |
1351 | oo = s->min; |
1352 | alloc_gfp = flags; |
1353 | /* |
1354 | * Allocation may have failed due to fragmentation. |
1355 | * Try a lower order alloc if possible |
1356 | */ |
1357 | page = alloc_slab_page(alloc_gfp, node, oo); |
1358 | |
1359 | if (page) |
1360 | stat(s, ORDER_FALLBACK); |
1361 | } |
1362 | |
1363 | if (kmemcheck_enabled && page |
1364 | && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) { |
1365 | int pages = 1 << oo_order(oo); |
1366 | |
1367 | kmemcheck_alloc_shadow(page, oo_order(oo), alloc_gfp, node); |
1368 | |
1369 | /* |
1370 | * Objects from caches that have a constructor don't get |
1371 | * cleared when they're allocated, so we need to do it here. |
1372 | */ |
1373 | if (s->ctor) |
1374 | kmemcheck_mark_uninitialized_pages(page, pages); |
1375 | else |
1376 | kmemcheck_mark_unallocated_pages(page, pages); |
1377 | } |
1378 | |
1379 | if (flags & __GFP_WAIT) |
1380 | local_irq_disable(); |
1381 | if (!page) |
1382 | return NULL; |
1383 | |
1384 | page->objects = oo_objects(oo); |
1385 | mod_zone_page_state(page_zone(page), |
1386 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? |
1387 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, |
1388 | 1 << oo_order(oo)); |
1389 | |
1390 | return page; |
1391 | } |
1392 | |
1393 | static void setup_object(struct kmem_cache *s, struct page *page, |
1394 | void *object) |
1395 | { |
1396 | setup_object_debug(s, page, object); |
1397 | if (unlikely(s->ctor)) |
1398 | s->ctor(object); |
1399 | } |
1400 | |
1401 | static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) |
1402 | { |
1403 | struct page *page; |
1404 | void *start; |
1405 | void *last; |
1406 | void *p; |
1407 | int order; |
1408 | |
1409 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
1410 | |
1411 | page = allocate_slab(s, |
1412 | flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node); |
1413 | if (!page) |
1414 | goto out; |
1415 | |
1416 | order = compound_order(page); |
1417 | inc_slabs_node(s, page_to_nid(page), page->objects); |
1418 | memcg_bind_pages(s, order); |
1419 | page->slab_cache = s; |
1420 | __SetPageSlab(page); |
1421 | if (page->pfmemalloc) |
1422 | SetPageSlabPfmemalloc(page); |
1423 | |
1424 | start = page_address(page); |
1425 | |
1426 | if (unlikely(s->flags & SLAB_POISON)) |
1427 | memset(start, POISON_INUSE, PAGE_SIZE << order); |
1428 | |
1429 | last = start; |
1430 | for_each_object(p, s, start, page->objects) { |
1431 | setup_object(s, page, last); |
1432 | set_freepointer(s, last, p); |
1433 | last = p; |
1434 | } |
1435 | setup_object(s, page, last); |
1436 | set_freepointer(s, last, NULL); |
1437 | |
1438 | page->freelist = start; |
1439 | page->inuse = page->objects; |
1440 | page->frozen = 1; |
1441 | out: |
1442 | return page; |
1443 | } |
1444 | |
1445 | static void __free_slab(struct kmem_cache *s, struct page *page) |
1446 | { |
1447 | int order = compound_order(page); |
1448 | int pages = 1 << order; |
1449 | |
1450 | if (kmem_cache_debug(s)) { |
1451 | void *p; |
1452 | |
1453 | slab_pad_check(s, page); |
1454 | for_each_object(p, s, page_address(page), |
1455 | page->objects) |
1456 | check_object(s, page, p, SLUB_RED_INACTIVE); |
1457 | } |
1458 | |
1459 | kmemcheck_free_shadow(page, compound_order(page)); |
1460 | |
1461 | mod_zone_page_state(page_zone(page), |
1462 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? |
1463 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, |
1464 | -pages); |
1465 | |
1466 | __ClearPageSlabPfmemalloc(page); |
1467 | __ClearPageSlab(page); |
1468 | |
1469 | memcg_release_pages(s, order); |
1470 | page_mapcount_reset(page); |
1471 | if (current->reclaim_state) |
1472 | current->reclaim_state->reclaimed_slab += pages; |
1473 | __free_memcg_kmem_pages(page, order); |
1474 | } |
1475 | |
1476 | #define need_reserve_slab_rcu \ |
1477 | (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head)) |
1478 | |
1479 | static void rcu_free_slab(struct rcu_head *h) |
1480 | { |
1481 | struct page *page; |
1482 | |
1483 | if (need_reserve_slab_rcu) |
1484 | page = virt_to_head_page(h); |
1485 | else |
1486 | page = container_of((struct list_head *)h, struct page, lru); |
1487 | |
1488 | __free_slab(page->slab_cache, page); |
1489 | } |
1490 | |
1491 | static void free_slab(struct kmem_cache *s, struct page *page) |
1492 | { |
1493 | if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { |
1494 | struct rcu_head *head; |
1495 | |
1496 | if (need_reserve_slab_rcu) { |
1497 | int order = compound_order(page); |
1498 | int offset = (PAGE_SIZE << order) - s->reserved; |
1499 | |
1500 | VM_BUG_ON(s->reserved != sizeof(*head)); |
1501 | head = page_address(page) + offset; |
1502 | } else { |
1503 | /* |
1504 | * RCU free overloads the RCU head over the LRU |
1505 | */ |
1506 | head = (void *)&page->lru; |
1507 | } |
1508 | |
1509 | call_rcu(head, rcu_free_slab); |
1510 | } else |
1511 | __free_slab(s, page); |
1512 | } |
1513 | |
1514 | static void discard_slab(struct kmem_cache *s, struct page *page) |
1515 | { |
1516 | dec_slabs_node(s, page_to_nid(page), page->objects); |
1517 | free_slab(s, page); |
1518 | } |
1519 | |
1520 | /* |
1521 | * Management of partially allocated slabs. |
1522 | */ |
1523 | static inline void |
1524 | __add_partial(struct kmem_cache_node *n, struct page *page, int tail) |
1525 | { |
1526 | n->nr_partial++; |
1527 | if (tail == DEACTIVATE_TO_TAIL) |
1528 | list_add_tail(&page->lru, &n->partial); |
1529 | else |
1530 | list_add(&page->lru, &n->partial); |
1531 | } |
1532 | |
1533 | static inline void add_partial(struct kmem_cache_node *n, |
1534 | struct page *page, int tail) |
1535 | { |
1536 | lockdep_assert_held(&n->list_lock); |
1537 | __add_partial(n, page, tail); |
1538 | } |
1539 | |
1540 | static inline void |
1541 | __remove_partial(struct kmem_cache_node *n, struct page *page) |
1542 | { |
1543 | list_del(&page->lru); |
1544 | n->nr_partial--; |
1545 | } |
1546 | |
1547 | static inline void remove_partial(struct kmem_cache_node *n, |
1548 | struct page *page) |
1549 | { |
1550 | lockdep_assert_held(&n->list_lock); |
1551 | __remove_partial(n, page); |
1552 | } |
1553 | |
1554 | /* |
1555 | * Remove slab from the partial list, freeze it and |
1556 | * return the pointer to the freelist. |
1557 | * |
1558 | * Returns a list of objects or NULL if it fails. |
1559 | */ |
1560 | static inline void *acquire_slab(struct kmem_cache *s, |
1561 | struct kmem_cache_node *n, struct page *page, |
1562 | int mode, int *objects) |
1563 | { |
1564 | void *freelist; |
1565 | unsigned long counters; |
1566 | struct page new; |
1567 | |
1568 | lockdep_assert_held(&n->list_lock); |
1569 | |
1570 | /* |
1571 | * Zap the freelist and set the frozen bit. |
1572 | * The old freelist is the list of objects for the |
1573 | * per cpu allocation list. |
1574 | */ |
1575 | freelist = page->freelist; |
1576 | counters = page->counters; |
1577 | new.counters = counters; |
1578 | *objects = new.objects - new.inuse; |
1579 | if (mode) { |
1580 | new.inuse = page->objects; |
1581 | new.freelist = NULL; |
1582 | } else { |
1583 | new.freelist = freelist; |
1584 | } |
1585 | |
1586 | VM_BUG_ON(new.frozen); |
1587 | new.frozen = 1; |
1588 | |
1589 | if (!__cmpxchg_double_slab(s, page, |
1590 | freelist, counters, |
1591 | new.freelist, new.counters, |
1592 | "acquire_slab")) |
1593 | return NULL; |
1594 | |
1595 | remove_partial(n, page); |
1596 | WARN_ON(!freelist); |
1597 | return freelist; |
1598 | } |
1599 | |
1600 | static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain); |
1601 | static inline bool pfmemalloc_match(struct page *page, gfp_t gfpflags); |
1602 | |
1603 | /* |
1604 | * Try to allocate a partial slab from a specific node. |
1605 | */ |
1606 | static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, |
1607 | struct kmem_cache_cpu *c, gfp_t flags) |
1608 | { |
1609 | struct page *page, *page2; |
1610 | void *object = NULL; |
1611 | int available = 0; |
1612 | int objects; |
1613 | |
1614 | /* |
1615 | * Racy check. If we mistakenly see no partial slabs then we |
1616 | * just allocate an empty slab. If we mistakenly try to get a |
1617 | * partial slab and there is none available then get_partials() |
1618 | * will return NULL. |
1619 | */ |
1620 | if (!n || !n->nr_partial) |
1621 | return NULL; |
1622 | |
1623 | spin_lock(&n->list_lock); |
1624 | list_for_each_entry_safe(page, page2, &n->partial, lru) { |
1625 | void *t; |
1626 | |
1627 | if (!pfmemalloc_match(page, flags)) |
1628 | continue; |
1629 | |
1630 | t = acquire_slab(s, n, page, object == NULL, &objects); |
1631 | if (!t) |
1632 | break; |
1633 | |
1634 | available += objects; |
1635 | if (!object) { |
1636 | c->page = page; |
1637 | stat(s, ALLOC_FROM_PARTIAL); |
1638 | object = t; |
1639 | } else { |
1640 | put_cpu_partial(s, page, 0); |
1641 | stat(s, CPU_PARTIAL_NODE); |
1642 | } |
1643 | if (!kmem_cache_has_cpu_partial(s) |
1644 | || available > s->cpu_partial / 2) |
1645 | break; |
1646 | |
1647 | } |
1648 | spin_unlock(&n->list_lock); |
1649 | return object; |
1650 | } |
1651 | |
1652 | /* |
1653 | * Get a page from somewhere. Search in increasing NUMA distances. |
1654 | */ |
1655 | static void *get_any_partial(struct kmem_cache *s, gfp_t flags, |
1656 | struct kmem_cache_cpu *c) |
1657 | { |
1658 | #ifdef CONFIG_NUMA |
1659 | struct zonelist *zonelist; |
1660 | struct zoneref *z; |
1661 | struct zone *zone; |
1662 | enum zone_type high_zoneidx = gfp_zone(flags); |
1663 | void *object; |
1664 | unsigned int cpuset_mems_cookie; |
1665 | |
1666 | /* |
1667 | * The defrag ratio allows a configuration of the tradeoffs between |
1668 | * inter node defragmentation and node local allocations. A lower |
1669 | * defrag_ratio increases the tendency to do local allocations |
1670 | * instead of attempting to obtain partial slabs from other nodes. |
1671 | * |
1672 | * If the defrag_ratio is set to 0 then kmalloc() always |
1673 | * returns node local objects. If the ratio is higher then kmalloc() |
1674 | * may return off node objects because partial slabs are obtained |
1675 | * from other nodes and filled up. |
1676 | * |
1677 | * If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes |
1678 | * defrag_ratio = 1000) then every (well almost) allocation will |
1679 | * first attempt to defrag slab caches on other nodes. This means |
1680 | * scanning over all nodes to look for partial slabs which may be |
1681 | * expensive if we do it every time we are trying to find a slab |
1682 | * with available objects. |
1683 | */ |
1684 | if (!s->remote_node_defrag_ratio || |
1685 | get_cycles() % 1024 > s->remote_node_defrag_ratio) |
1686 | return NULL; |
1687 | |
1688 | do { |
1689 | cpuset_mems_cookie = read_mems_allowed_begin(); |
1690 | zonelist = node_zonelist(mempolicy_slab_node(), flags); |
1691 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
1692 | struct kmem_cache_node *n; |
1693 | |
1694 | n = get_node(s, zone_to_nid(zone)); |
1695 | |
1696 | if (n && cpuset_zone_allowed_hardwall(zone, flags) && |
1697 | n->nr_partial > s->min_partial) { |
1698 | object = get_partial_node(s, n, c, flags); |
1699 | if (object) { |
1700 | /* |
1701 | * Don't check read_mems_allowed_retry() |
1702 | * here - if mems_allowed was updated in |
1703 | * parallel, that was a harmless race |
1704 | * between allocation and the cpuset |
1705 | * update |
1706 | */ |
1707 | return object; |
1708 | } |
1709 | } |
1710 | } |
1711 | } while (read_mems_allowed_retry(cpuset_mems_cookie)); |
1712 | #endif |
1713 | return NULL; |
1714 | } |
1715 | |
1716 | /* |
1717 | * Get a partial page, lock it and return it. |
1718 | */ |
1719 | static void *get_partial(struct kmem_cache *s, gfp_t flags, int node, |
1720 | struct kmem_cache_cpu *c) |
1721 | { |
1722 | void *object; |
1723 | int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node; |
1724 | |
1725 | object = get_partial_node(s, get_node(s, searchnode), c, flags); |
1726 | if (object || node != NUMA_NO_NODE) |
1727 | return object; |
1728 | |
1729 | return get_any_partial(s, flags, c); |
1730 | } |
1731 | |
1732 | #ifdef CONFIG_PREEMPT |
1733 | /* |
1734 | * Calculate the next globally unique transaction for disambiguiation |
1735 | * during cmpxchg. The transactions start with the cpu number and are then |
1736 | * incremented by CONFIG_NR_CPUS. |
1737 | */ |
1738 | #define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS) |
1739 | #else |
1740 | /* |
1741 | * No preemption supported therefore also no need to check for |
1742 | * different cpus. |
1743 | */ |
1744 | #define TID_STEP 1 |
1745 | #endif |
1746 | |
1747 | static inline unsigned long next_tid(unsigned long tid) |
1748 | { |
1749 | return tid + TID_STEP; |
1750 | } |
1751 | |
1752 | static inline unsigned int tid_to_cpu(unsigned long tid) |
1753 | { |
1754 | return tid % TID_STEP; |
1755 | } |
1756 | |
1757 | static inline unsigned long tid_to_event(unsigned long tid) |
1758 | { |
1759 | return tid / TID_STEP; |
1760 | } |
1761 | |
1762 | static inline unsigned int init_tid(int cpu) |
1763 | { |
1764 | return cpu; |
1765 | } |
1766 | |
1767 | static inline void note_cmpxchg_failure(const char *n, |
1768 | const struct kmem_cache *s, unsigned long tid) |
1769 | { |
1770 | #ifdef SLUB_DEBUG_CMPXCHG |
1771 | unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid); |
1772 | |
1773 | printk(KERN_INFO "%s %s: cmpxchg redo ", n, s->name); |
1774 | |
1775 | #ifdef CONFIG_PREEMPT |
1776 | if (tid_to_cpu(tid) != tid_to_cpu(actual_tid)) |
1777 | printk("due to cpu change %d -> %d\n", |
1778 | tid_to_cpu(tid), tid_to_cpu(actual_tid)); |
1779 | else |
1780 | #endif |
1781 | if (tid_to_event(tid) != tid_to_event(actual_tid)) |
1782 | printk("due to cpu running other code. Event %ld->%ld\n", |
1783 | tid_to_event(tid), tid_to_event(actual_tid)); |
1784 | else |
1785 | printk("for unknown reason: actual=%lx was=%lx target=%lx\n", |
1786 | actual_tid, tid, next_tid(tid)); |
1787 | #endif |
1788 | stat(s, CMPXCHG_DOUBLE_CPU_FAIL); |
1789 | } |
1790 | |
1791 | static void init_kmem_cache_cpus(struct kmem_cache *s) |
1792 | { |
1793 | int cpu; |
1794 | |
1795 | for_each_possible_cpu(cpu) |
1796 | per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu); |
1797 | } |
1798 | |
1799 | /* |
1800 | * Remove the cpu slab |
1801 | */ |
1802 | static void deactivate_slab(struct kmem_cache *s, struct page *page, |
1803 | void *freelist) |
1804 | { |
1805 | enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE }; |
1806 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); |
1807 | int lock = 0; |
1808 | enum slab_modes l = M_NONE, m = M_NONE; |
1809 | void *nextfree; |
1810 | int tail = DEACTIVATE_TO_HEAD; |
1811 | struct page new; |
1812 | struct page old; |
1813 | |
1814 | if (page->freelist) { |
1815 | stat(s, DEACTIVATE_REMOTE_FREES); |
1816 | tail = DEACTIVATE_TO_TAIL; |
1817 | } |
1818 | |
1819 | /* |
1820 | * Stage one: Free all available per cpu objects back |
1821 | * to the page freelist while it is still frozen. Leave the |
1822 | * last one. |
1823 | * |
1824 | * There is no need to take the list->lock because the page |
1825 | * is still frozen. |
1826 | */ |
1827 | while (freelist && (nextfree = get_freepointer(s, freelist))) { |
1828 | void *prior; |
1829 | unsigned long counters; |
1830 | |
1831 | do { |
1832 | prior = page->freelist; |
1833 | counters = page->counters; |
1834 | set_freepointer(s, freelist, prior); |
1835 | new.counters = counters; |
1836 | new.inuse--; |
1837 | VM_BUG_ON(!new.frozen); |
1838 | |
1839 | } while (!__cmpxchg_double_slab(s, page, |
1840 | prior, counters, |
1841 | freelist, new.counters, |
1842 | "drain percpu freelist")); |
1843 | |
1844 | freelist = nextfree; |
1845 | } |
1846 | |
1847 | /* |
1848 | * Stage two: Ensure that the page is unfrozen while the |
1849 | * list presence reflects the actual number of objects |
1850 | * during unfreeze. |
1851 | * |
1852 | * We setup the list membership and then perform a cmpxchg |
1853 | * with the count. If there is a mismatch then the page |
1854 | * is not unfrozen but the page is on the wrong list. |
1855 | * |
1856 | * Then we restart the process which may have to remove |
1857 | * the page from the list that we just put it on again |
1858 | * because the number of objects in the slab may have |
1859 | * changed. |
1860 | */ |
1861 | redo: |
1862 | |
1863 | old.freelist = page->freelist; |
1864 | old.counters = page->counters; |
1865 | VM_BUG_ON(!old.frozen); |
1866 | |
1867 | /* Determine target state of the slab */ |
1868 | new.counters = old.counters; |
1869 | if (freelist) { |
1870 | new.inuse--; |
1871 | set_freepointer(s, freelist, old.freelist); |
1872 | new.freelist = freelist; |
1873 | } else |
1874 | new.freelist = old.freelist; |
1875 | |
1876 | new.frozen = 0; |
1877 | |
1878 | if (!new.inuse && n->nr_partial > s->min_partial) |
1879 | m = M_FREE; |
1880 | else if (new.freelist) { |
1881 | m = M_PARTIAL; |
1882 | if (!lock) { |
1883 | lock = 1; |
1884 | /* |
1885 | * Taking the spinlock removes the possiblity |
1886 | * that acquire_slab() will see a slab page that |
1887 | * is frozen |
1888 | */ |
1889 | spin_lock(&n->list_lock); |
1890 | } |
1891 | } else { |
1892 | m = M_FULL; |
1893 | if (kmem_cache_debug(s) && !lock) { |
1894 | lock = 1; |
1895 | /* |
1896 | * This also ensures that the scanning of full |
1897 | * slabs from diagnostic functions will not see |
1898 | * any frozen slabs. |
1899 | */ |
1900 | spin_lock(&n->list_lock); |
1901 | } |
1902 | } |
1903 | |
1904 | if (l != m) { |
1905 | |
1906 | if (l == M_PARTIAL) |
1907 | |
1908 | remove_partial(n, page); |
1909 | |
1910 | else if (l == M_FULL) |
1911 | |
1912 | remove_full(s, n, page); |
1913 | |
1914 | if (m == M_PARTIAL) { |
1915 | |
1916 | add_partial(n, page, tail); |
1917 | stat(s, tail); |
1918 | |
1919 | } else if (m == M_FULL) { |
1920 | |
1921 | stat(s, DEACTIVATE_FULL); |
1922 | add_full(s, n, page); |
1923 | |
1924 | } |
1925 | } |
1926 | |
1927 | l = m; |
1928 | if (!__cmpxchg_double_slab(s, page, |
1929 | old.freelist, old.counters, |
1930 | new.freelist, new.counters, |
1931 | "unfreezing slab")) |
1932 | goto redo; |
1933 | |
1934 | if (lock) |
1935 | spin_unlock(&n->list_lock); |
1936 | |
1937 | if (m == M_FREE) { |
1938 | stat(s, DEACTIVATE_EMPTY); |
1939 | discard_slab(s, page); |
1940 | stat(s, FREE_SLAB); |
1941 | } |
1942 | } |
1943 | |
1944 | /* |
1945 | * Unfreeze all the cpu partial slabs. |
1946 | * |
1947 | * This function must be called with interrupts disabled |
1948 | * for the cpu using c (or some other guarantee must be there |
1949 | * to guarantee no concurrent accesses). |
1950 | */ |
1951 | static void unfreeze_partials(struct kmem_cache *s, |
1952 | struct kmem_cache_cpu *c) |
1953 | { |
1954 | #ifdef CONFIG_SLUB_CPU_PARTIAL |
1955 | struct kmem_cache_node *n = NULL, *n2 = NULL; |
1956 | struct page *page, *discard_page = NULL; |
1957 | |
1958 | while ((page = c->partial)) { |
1959 | struct page new; |
1960 | struct page old; |
1961 | |
1962 | c->partial = page->next; |
1963 | |
1964 | n2 = get_node(s, page_to_nid(page)); |
1965 | if (n != n2) { |
1966 | if (n) |
1967 | spin_unlock(&n->list_lock); |
1968 | |
1969 | n = n2; |
1970 | spin_lock(&n->list_lock); |
1971 | } |
1972 | |
1973 | do { |
1974 | |
1975 | old.freelist = page->freelist; |
1976 | old.counters = page->counters; |
1977 | VM_BUG_ON(!old.frozen); |
1978 | |
1979 | new.counters = old.counters; |
1980 | new.freelist = old.freelist; |
1981 | |
1982 | new.frozen = 0; |
1983 | |
1984 | } while (!__cmpxchg_double_slab(s, page, |
1985 | old.freelist, old.counters, |
1986 | new.freelist, new.counters, |
1987 | "unfreezing slab")); |
1988 | |
1989 | if (unlikely(!new.inuse && n->nr_partial > s->min_partial)) { |
1990 | page->next = discard_page; |
1991 | discard_page = page; |
1992 | } else { |
1993 | add_partial(n, page, DEACTIVATE_TO_TAIL); |
1994 | stat(s, FREE_ADD_PARTIAL); |
1995 | } |
1996 | } |
1997 | |
1998 | if (n) |
1999 | spin_unlock(&n->list_lock); |
2000 | |
2001 | while (discard_page) { |
2002 | page = discard_page; |
2003 | discard_page = discard_page->next; |
2004 | |
2005 | stat(s, DEACTIVATE_EMPTY); |
2006 | discard_slab(s, page); |
2007 | stat(s, FREE_SLAB); |
2008 | } |
2009 | #endif |
2010 | } |
2011 | |
2012 | /* |
2013 | * Put a page that was just frozen (in __slab_free) into a partial page |
2014 | * slot if available. This is done without interrupts disabled and without |
2015 | * preemption disabled. The cmpxchg is racy and may put the partial page |
2016 | * onto a random cpus partial slot. |
2017 | * |
2018 | * If we did not find a slot then simply move all the partials to the |
2019 | * per node partial list. |
2020 | */ |
2021 | static void put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) |
2022 | { |
2023 | #ifdef CONFIG_SLUB_CPU_PARTIAL |
2024 | struct page *oldpage; |
2025 | int pages; |
2026 | int pobjects; |
2027 | |
2028 | do { |
2029 | pages = 0; |
2030 | pobjects = 0; |
2031 | oldpage = this_cpu_read(s->cpu_slab->partial); |
2032 | |
2033 | if (oldpage) { |
2034 | pobjects = oldpage->pobjects; |
2035 | pages = oldpage->pages; |
2036 | if (drain && pobjects > s->cpu_partial) { |
2037 | unsigned long flags; |
2038 | /* |
2039 | * partial array is full. Move the existing |
2040 | * set to the per node partial list. |
2041 | */ |
2042 | local_irq_save(flags); |
2043 | unfreeze_partials(s, this_cpu_ptr(s->cpu_slab)); |
2044 | local_irq_restore(flags); |
2045 | oldpage = NULL; |
2046 | pobjects = 0; |
2047 | pages = 0; |
2048 | stat(s, CPU_PARTIAL_DRAIN); |
2049 | } |
2050 | } |
2051 | |
2052 | pages++; |
2053 | pobjects += page->objects - page->inuse; |
2054 | |
2055 | page->pages = pages; |
2056 | page->pobjects = pobjects; |
2057 | page->next = oldpage; |
2058 | |
2059 | } while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) |
2060 | != oldpage); |
2061 | #endif |
2062 | } |
2063 | |
2064 | static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) |
2065 | { |
2066 | stat(s, CPUSLAB_FLUSH); |
2067 | deactivate_slab(s, c->page, c->freelist); |
2068 | |
2069 | c->tid = next_tid(c->tid); |
2070 | c->page = NULL; |
2071 | c->freelist = NULL; |
2072 | } |
2073 | |
2074 | /* |
2075 | * Flush cpu slab. |
2076 | * |
2077 | * Called from IPI handler with interrupts disabled. |
2078 | */ |
2079 | static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) |
2080 | { |
2081 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); |
2082 | |
2083 | if (likely(c)) { |
2084 | if (c->page) |
2085 | flush_slab(s, c); |
2086 | |
2087 | unfreeze_partials(s, c); |
2088 | } |
2089 | } |
2090 | |
2091 | static void flush_cpu_slab(void *d) |
2092 | { |
2093 | struct kmem_cache *s = d; |
2094 | |
2095 | __flush_cpu_slab(s, smp_processor_id()); |
2096 | } |
2097 | |
2098 | static bool has_cpu_slab(int cpu, void *info) |
2099 | { |
2100 | struct kmem_cache *s = info; |
2101 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); |
2102 | |
2103 | return c->page || c->partial; |
2104 | } |
2105 | |
2106 | static void flush_all(struct kmem_cache *s) |
2107 | { |
2108 | on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC); |
2109 | } |
2110 | |
2111 | /* |
2112 | * Check if the objects in a per cpu structure fit numa |
2113 | * locality expectations. |
2114 | */ |
2115 | static inline int node_match(struct page *page, int node) |
2116 | { |
2117 | #ifdef CONFIG_NUMA |
2118 | if (!page || (node != NUMA_NO_NODE && page_to_nid(page) != node)) |
2119 | return 0; |
2120 | #endif |
2121 | return 1; |
2122 | } |
2123 | |
2124 | static int count_free(struct page *page) |
2125 | { |
2126 | return page->objects - page->inuse; |
2127 | } |
2128 | |
2129 | static unsigned long count_partial(struct kmem_cache_node *n, |
2130 | int (*get_count)(struct page *)) |
2131 | { |
2132 | unsigned long flags; |
2133 | unsigned long x = 0; |
2134 | struct page *page; |
2135 | |
2136 | spin_lock_irqsave(&n->list_lock, flags); |
2137 | list_for_each_entry(page, &n->partial, lru) |
2138 | x += get_count(page); |
2139 | spin_unlock_irqrestore(&n->list_lock, flags); |
2140 | return x; |
2141 | } |
2142 | |
2143 | static inline unsigned long node_nr_objs(struct kmem_cache_node *n) |
2144 | { |
2145 | #ifdef CONFIG_SLUB_DEBUG |
2146 | return atomic_long_read(&n->total_objects); |
2147 | #else |
2148 | return 0; |
2149 | #endif |
2150 | } |
2151 | |
2152 | static noinline void |
2153 | slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) |
2154 | { |
2155 | int node; |
2156 | |
2157 | printk(KERN_WARNING |
2158 | "SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
2159 | nid, gfpflags); |
2160 | printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, " |
2161 | "default order: %d, min order: %d\n", s->name, s->object_size, |
2162 | s->size, oo_order(s->oo), oo_order(s->min)); |
2163 | |
2164 | if (oo_order(s->min) > get_order(s->object_size)) |
2165 | printk(KERN_WARNING " %s debugging increased min order, use " |
2166 | "slub_debug=O to disable.\n", s->name); |
2167 | |
2168 | for_each_online_node(node) { |
2169 | struct kmem_cache_node *n = get_node(s, node); |
2170 | unsigned long nr_slabs; |
2171 | unsigned long nr_objs; |
2172 | unsigned long nr_free; |
2173 | |
2174 | if (!n) |
2175 | continue; |
2176 | |
2177 | nr_free = count_partial(n, count_free); |
2178 | nr_slabs = node_nr_slabs(n); |
2179 | nr_objs = node_nr_objs(n); |
2180 | |
2181 | printk(KERN_WARNING |
2182 | " node %d: slabs: %ld, objs: %ld, free: %ld\n", |
2183 | node, nr_slabs, nr_objs, nr_free); |
2184 | } |
2185 | } |
2186 | |
2187 | static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags, |
2188 | int node, struct kmem_cache_cpu **pc) |
2189 | { |
2190 | void *freelist; |
2191 | struct kmem_cache_cpu *c = *pc; |
2192 | struct page *page; |
2193 | |
2194 | freelist = get_partial(s, flags, node, c); |
2195 | |
2196 | if (freelist) |
2197 | return freelist; |
2198 | |
2199 | page = new_slab(s, flags, node); |
2200 | if (page) { |
2201 | c = __this_cpu_ptr(s->cpu_slab); |
2202 | if (c->page) |
2203 | flush_slab(s, c); |
2204 | |
2205 | /* |
2206 | * No other reference to the page yet so we can |
2207 | * muck around with it freely without cmpxchg |
2208 | */ |
2209 | freelist = page->freelist; |
2210 | page->freelist = NULL; |
2211 | |
2212 | stat(s, ALLOC_SLAB); |
2213 | c->page = page; |
2214 | *pc = c; |
2215 | } else |
2216 | freelist = NULL; |
2217 | |
2218 | return freelist; |
2219 | } |
2220 | |
2221 | static inline bool pfmemalloc_match(struct page *page, gfp_t gfpflags) |
2222 | { |
2223 | if (unlikely(PageSlabPfmemalloc(page))) |
2224 | return gfp_pfmemalloc_allowed(gfpflags); |
2225 | |
2226 | return true; |
2227 | } |
2228 | |
2229 | /* |
2230 | * Check the page->freelist of a page and either transfer the freelist to the |
2231 | * per cpu freelist or deactivate the page. |
2232 | * |
2233 | * The page is still frozen if the return value is not NULL. |
2234 | * |
2235 | * If this function returns NULL then the page has been unfrozen. |
2236 | * |
2237 | * This function must be called with interrupt disabled. |
2238 | */ |
2239 | static inline void *get_freelist(struct kmem_cache *s, struct page *page) |
2240 | { |
2241 | struct page new; |
2242 | unsigned long counters; |
2243 | void *freelist; |
2244 | |
2245 | do { |
2246 | freelist = page->freelist; |
2247 | counters = page->counters; |
2248 | |
2249 | new.counters = counters; |
2250 | VM_BUG_ON(!new.frozen); |
2251 | |
2252 | new.inuse = page->objects; |
2253 | new.frozen = freelist != NULL; |
2254 | |
2255 | } while (!__cmpxchg_double_slab(s, page, |
2256 | freelist, counters, |
2257 | NULL, new.counters, |
2258 | "get_freelist")); |
2259 | |
2260 | return freelist; |
2261 | } |
2262 | |
2263 | /* |
2264 | * Slow path. The lockless freelist is empty or we need to perform |
2265 | * debugging duties. |
2266 | * |
2267 | * Processing is still very fast if new objects have been freed to the |
2268 | * regular freelist. In that case we simply take over the regular freelist |
2269 | * as the lockless freelist and zap the regular freelist. |
2270 | * |
2271 | * If that is not working then we fall back to the partial lists. We take the |
2272 | * first element of the freelist as the object to allocate now and move the |
2273 | * rest of the freelist to the lockless freelist. |
2274 | * |
2275 | * And if we were unable to get a new slab from the partial slab lists then |
2276 | * we need to allocate a new slab. This is the slowest path since it involves |
2277 | * a call to the page allocator and the setup of a new slab. |
2278 | */ |
2279 | static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, |
2280 | unsigned long addr, struct kmem_cache_cpu *c) |
2281 | { |
2282 | void *freelist; |
2283 | struct page *page; |
2284 | unsigned long flags; |
2285 | |
2286 | local_irq_save(flags); |
2287 | #ifdef CONFIG_PREEMPT |
2288 | /* |
2289 | * We may have been preempted and rescheduled on a different |
2290 | * cpu before disabling interrupts. Need to reload cpu area |
2291 | * pointer. |
2292 | */ |
2293 | c = this_cpu_ptr(s->cpu_slab); |
2294 | #endif |
2295 | |
2296 | page = c->page; |
2297 | if (!page) |
2298 | goto new_slab; |
2299 | redo: |
2300 | |
2301 | if (unlikely(!node_match(page, node))) { |
2302 | stat(s, ALLOC_NODE_MISMATCH); |
2303 | deactivate_slab(s, page, c->freelist); |
2304 | c->page = NULL; |
2305 | c->freelist = NULL; |
2306 | goto new_slab; |
2307 | } |
2308 | |
2309 | /* |
2310 | * By rights, we should be searching for a slab page that was |
2311 | * PFMEMALLOC but right now, we are losing the pfmemalloc |
2312 | * information when the page leaves the per-cpu allocator |
2313 | */ |
2314 | if (unlikely(!pfmemalloc_match(page, gfpflags))) { |
2315 | deactivate_slab(s, page, c->freelist); |
2316 | c->page = NULL; |
2317 | c->freelist = NULL; |
2318 | goto new_slab; |
2319 | } |
2320 | |
2321 | /* must check again c->freelist in case of cpu migration or IRQ */ |
2322 | freelist = c->freelist; |
2323 | if (freelist) |
2324 | goto load_freelist; |
2325 | |
2326 | stat(s, ALLOC_SLOWPATH); |
2327 | |
2328 | freelist = get_freelist(s, page); |
2329 | |
2330 | if (!freelist) { |
2331 | c->page = NULL; |
2332 | stat(s, DEACTIVATE_BYPASS); |
2333 | goto new_slab; |
2334 | } |
2335 | |
2336 | stat(s, ALLOC_REFILL); |
2337 | |
2338 | load_freelist: |
2339 | /* |
2340 | * freelist is pointing to the list of objects to be used. |
2341 | * page is pointing to the page from which the objects are obtained. |
2342 | * That page must be frozen for per cpu allocations to work. |
2343 | */ |
2344 | VM_BUG_ON(!c->page->frozen); |
2345 | c->freelist = get_freepointer(s, freelist); |
2346 | c->tid = next_tid(c->tid); |
2347 | local_irq_restore(flags); |
2348 | return freelist; |
2349 | |
2350 | new_slab: |
2351 | |
2352 | if (c->partial) { |
2353 | page = c->page = c->partial; |
2354 | c->partial = page->next; |
2355 | stat(s, CPU_PARTIAL_ALLOC); |
2356 | c->freelist = NULL; |
2357 | goto redo; |
2358 | } |
2359 | |
2360 | freelist = new_slab_objects(s, gfpflags, node, &c); |
2361 | |
2362 | if (unlikely(!freelist)) { |
2363 | if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit()) |
2364 | slab_out_of_memory(s, gfpflags, node); |
2365 | |
2366 | local_irq_restore(flags); |
2367 | return NULL; |
2368 | } |
2369 | |
2370 | page = c->page; |
2371 | if (likely(!kmem_cache_debug(s) && pfmemalloc_match(page, gfpflags))) |
2372 | goto load_freelist; |
2373 | |
2374 | /* Only entered in the debug case */ |
2375 | if (kmem_cache_debug(s) && |
2376 | !alloc_debug_processing(s, page, freelist, addr)) |
2377 | goto new_slab; /* Slab failed checks. Next slab needed */ |
2378 | |
2379 | deactivate_slab(s, page, get_freepointer(s, freelist)); |
2380 | c->page = NULL; |
2381 | c->freelist = NULL; |
2382 | local_irq_restore(flags); |
2383 | return freelist; |
2384 | } |
2385 | |
2386 | /* |
2387 | * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc) |
2388 | * have the fastpath folded into their functions. So no function call |
2389 | * overhead for requests that can be satisfied on the fastpath. |
2390 | * |
2391 | * The fastpath works by first checking if the lockless freelist can be used. |
2392 | * If not then __slab_alloc is called for slow processing. |
2393 | * |
2394 | * Otherwise we can simply pick the next object from the lockless free list. |
2395 | */ |
2396 | static __always_inline void *slab_alloc_node(struct kmem_cache *s, |
2397 | gfp_t gfpflags, int node, unsigned long addr) |
2398 | { |
2399 | void **object; |
2400 | struct kmem_cache_cpu *c; |
2401 | struct page *page; |
2402 | unsigned long tid; |
2403 | |
2404 | if (slab_pre_alloc_hook(s, gfpflags)) |
2405 | return NULL; |
2406 | |
2407 | s = memcg_kmem_get_cache(s, gfpflags); |
2408 | redo: |
2409 | /* |
2410 | * Must read kmem_cache cpu data via this cpu ptr. Preemption is |
2411 | * enabled. We may switch back and forth between cpus while |
2412 | * reading from one cpu area. That does not matter as long |
2413 | * as we end up on the original cpu again when doing the cmpxchg. |
2414 | * |
2415 | * Preemption is disabled for the retrieval of the tid because that |
2416 | * must occur from the current processor. We cannot allow rescheduling |
2417 | * on a different processor between the determination of the pointer |
2418 | * and the retrieval of the tid. |
2419 | */ |
2420 | preempt_disable(); |
2421 | c = __this_cpu_ptr(s->cpu_slab); |
2422 | |
2423 | /* |
2424 | * The transaction ids are globally unique per cpu and per operation on |
2425 | * a per cpu queue. Thus they can be guarantee that the cmpxchg_double |
2426 | * occurs on the right processor and that there was no operation on the |
2427 | * linked list in between. |
2428 | */ |
2429 | tid = c->tid; |
2430 | preempt_enable(); |
2431 | |
2432 | object = c->freelist; |
2433 | page = c->page; |
2434 | if (unlikely(!object || !node_match(page, node))) |
2435 | object = __slab_alloc(s, gfpflags, node, addr, c); |
2436 | |
2437 | else { |
2438 | void *next_object = get_freepointer_safe(s, object); |
2439 | |
2440 | /* |
2441 | * The cmpxchg will only match if there was no additional |
2442 | * operation and if we are on the right processor. |
2443 | * |
2444 | * The cmpxchg does the following atomically (without lock |
2445 | * semantics!) |
2446 | * 1. Relocate first pointer to the current per cpu area. |
2447 | * 2. Verify that tid and freelist have not been changed |
2448 | * 3. If they were not changed replace tid and freelist |
2449 | * |
2450 | * Since this is without lock semantics the protection is only |
2451 | * against code executing on this cpu *not* from access by |
2452 | * other cpus. |
2453 | */ |
2454 | if (unlikely(!this_cpu_cmpxchg_double( |
2455 | s->cpu_slab->freelist, s->cpu_slab->tid, |
2456 | object, tid, |
2457 | next_object, next_tid(tid)))) { |
2458 | |
2459 | note_cmpxchg_failure("slab_alloc", s, tid); |
2460 | goto redo; |
2461 | } |
2462 | prefetch_freepointer(s, next_object); |
2463 | stat(s, ALLOC_FASTPATH); |
2464 | } |
2465 | |
2466 | if (unlikely(gfpflags & __GFP_ZERO) && object) |
2467 | memset(object, 0, s->object_size); |
2468 | |
2469 | slab_post_alloc_hook(s, gfpflags, object); |
2470 | |
2471 | return object; |
2472 | } |
2473 | |
2474 | static __always_inline void *slab_alloc(struct kmem_cache *s, |
2475 | gfp_t gfpflags, unsigned long addr) |
2476 | { |
2477 | return slab_alloc_node(s, gfpflags, NUMA_NO_NODE, addr); |
2478 | } |
2479 | |
2480 | void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) |
2481 | { |
2482 | void *ret = slab_alloc(s, gfpflags, _RET_IP_); |
2483 | |
2484 | trace_kmem_cache_alloc(_RET_IP_, ret, s->object_size, |
2485 | s->size, gfpflags); |
2486 | |
2487 | return ret; |
2488 | } |
2489 | EXPORT_SYMBOL(kmem_cache_alloc); |
2490 | |
2491 | #ifdef CONFIG_TRACING |
2492 | void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size) |
2493 | { |
2494 | void *ret = slab_alloc(s, gfpflags, _RET_IP_); |
2495 | trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags); |
2496 | return ret; |
2497 | } |
2498 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
2499 | #endif |
2500 | |
2501 | #ifdef CONFIG_NUMA |
2502 | void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node) |
2503 | { |
2504 | void *ret = slab_alloc_node(s, gfpflags, node, _RET_IP_); |
2505 | |
2506 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
2507 | s->object_size, s->size, gfpflags, node); |
2508 | |
2509 | return ret; |
2510 | } |
2511 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
2512 | |
2513 | #ifdef CONFIG_TRACING |
2514 | void *kmem_cache_alloc_node_trace(struct kmem_cache *s, |
2515 | gfp_t gfpflags, |
2516 | int node, size_t size) |
2517 | { |
2518 | void *ret = slab_alloc_node(s, gfpflags, node, _RET_IP_); |
2519 | |
2520 | trace_kmalloc_node(_RET_IP_, ret, |
2521 | size, s->size, gfpflags, node); |
2522 | return ret; |
2523 | } |
2524 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
2525 | #endif |
2526 | #endif |
2527 | |
2528 | /* |
2529 | * Slow patch handling. This may still be called frequently since objects |
2530 | * have a longer lifetime than the cpu slabs in most processing loads. |
2531 | * |
2532 | * So we still attempt to reduce cache line usage. Just take the slab |
2533 | * lock and free the item. If there is no additional partial page |
2534 | * handling required then we can return immediately. |
2535 | */ |
2536 | static void __slab_free(struct kmem_cache *s, struct page *page, |
2537 | void *x, unsigned long addr) |
2538 | { |
2539 | void *prior; |
2540 | void **object = (void *)x; |
2541 | int was_frozen; |
2542 | struct page new; |
2543 | unsigned long counters; |
2544 | struct kmem_cache_node *n = NULL; |
2545 | unsigned long uninitialized_var(flags); |
2546 | |
2547 | stat(s, FREE_SLOWPATH); |
2548 | |
2549 | if (kmem_cache_debug(s) && |
2550 | !(n = free_debug_processing(s, page, x, addr, &flags))) |
2551 | return; |
2552 | |
2553 | do { |
2554 | if (unlikely(n)) { |
2555 | spin_unlock_irqrestore(&n->list_lock, flags); |
2556 | n = NULL; |
2557 | } |
2558 | prior = page->freelist; |
2559 | counters = page->counters; |
2560 | set_freepointer(s, object, prior); |
2561 | new.counters = counters; |
2562 | was_frozen = new.frozen; |
2563 | new.inuse--; |
2564 | if ((!new.inuse || !prior) && !was_frozen) { |
2565 | |
2566 | if (kmem_cache_has_cpu_partial(s) && !prior) { |
2567 | |
2568 | /* |
2569 | * Slab was on no list before and will be |
2570 | * partially empty |
2571 | * We can defer the list move and instead |
2572 | * freeze it. |
2573 | */ |
2574 | new.frozen = 1; |
2575 | |
2576 | } else { /* Needs to be taken off a list */ |
2577 | |
2578 | n = get_node(s, page_to_nid(page)); |
2579 | /* |
2580 | * Speculatively acquire the list_lock. |
2581 | * If the cmpxchg does not succeed then we may |
2582 | * drop the list_lock without any processing. |
2583 | * |
2584 | * Otherwise the list_lock will synchronize with |
2585 | * other processors updating the list of slabs. |
2586 | */ |
2587 | spin_lock_irqsave(&n->list_lock, flags); |
2588 | |
2589 | } |
2590 | } |
2591 | |
2592 | } while (!cmpxchg_double_slab(s, page, |
2593 | prior, counters, |
2594 | object, new.counters, |
2595 | "__slab_free")); |
2596 | |
2597 | if (likely(!n)) { |
2598 | |
2599 | /* |
2600 | * If we just froze the page then put it onto the |
2601 | * per cpu partial list. |
2602 | */ |
2603 | if (new.frozen && !was_frozen) { |
2604 | put_cpu_partial(s, page, 1); |
2605 | stat(s, CPU_PARTIAL_FREE); |
2606 | } |
2607 | /* |
2608 | * The list lock was not taken therefore no list |
2609 | * activity can be necessary. |
2610 | */ |
2611 | if (was_frozen) |
2612 | stat(s, FREE_FROZEN); |
2613 | return; |
2614 | } |
2615 | |
2616 | if (unlikely(!new.inuse && n->nr_partial > s->min_partial)) |
2617 | goto slab_empty; |
2618 | |
2619 | /* |
2620 | * Objects left in the slab. If it was not on the partial list before |
2621 | * then add it. |
2622 | */ |
2623 | if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) { |
2624 | if (kmem_cache_debug(s)) |
2625 | remove_full(s, n, page); |
2626 | add_partial(n, page, DEACTIVATE_TO_TAIL); |
2627 | stat(s, FREE_ADD_PARTIAL); |
2628 | } |
2629 | spin_unlock_irqrestore(&n->list_lock, flags); |
2630 | return; |
2631 | |
2632 | slab_empty: |
2633 | if (prior) { |
2634 | /* |
2635 | * Slab on the partial list. |
2636 | */ |
2637 | remove_partial(n, page); |
2638 | stat(s, FREE_REMOVE_PARTIAL); |
2639 | } else { |
2640 | /* Slab must be on the full list */ |
2641 | remove_full(s, n, page); |
2642 | } |
2643 | |
2644 | spin_unlock_irqrestore(&n->list_lock, flags); |
2645 | stat(s, FREE_SLAB); |
2646 | discard_slab(s, page); |
2647 | } |
2648 | |
2649 | /* |
2650 | * Fastpath with forced inlining to produce a kfree and kmem_cache_free that |
2651 | * can perform fastpath freeing without additional function calls. |
2652 | * |
2653 | * The fastpath is only possible if we are freeing to the current cpu slab |
2654 | * of this processor. This typically the case if we have just allocated |
2655 | * the item before. |
2656 | * |
2657 | * If fastpath is not possible then fall back to __slab_free where we deal |
2658 | * with all sorts of special processing. |
2659 | */ |
2660 | static __always_inline void slab_free(struct kmem_cache *s, |
2661 | struct page *page, void *x, unsigned long addr) |
2662 | { |
2663 | void **object = (void *)x; |
2664 | struct kmem_cache_cpu *c; |
2665 | unsigned long tid; |
2666 | |
2667 | slab_free_hook(s, x); |
2668 | |
2669 | redo: |
2670 | /* |
2671 | * Determine the currently cpus per cpu slab. |
2672 | * The cpu may change afterward. However that does not matter since |
2673 | * data is retrieved via this pointer. If we are on the same cpu |
2674 | * during the cmpxchg then the free will succedd. |
2675 | */ |
2676 | preempt_disable(); |
2677 | c = __this_cpu_ptr(s->cpu_slab); |
2678 | |
2679 | tid = c->tid; |
2680 | preempt_enable(); |
2681 | |
2682 | if (likely(page == c->page)) { |
2683 | set_freepointer(s, object, c->freelist); |
2684 | |
2685 | if (unlikely(!this_cpu_cmpxchg_double( |
2686 | s->cpu_slab->freelist, s->cpu_slab->tid, |
2687 | c->freelist, tid, |
2688 | object, next_tid(tid)))) { |
2689 | |
2690 | note_cmpxchg_failure("slab_free", s, tid); |
2691 | goto redo; |
2692 | } |
2693 | stat(s, FREE_FASTPATH); |
2694 | } else |
2695 | __slab_free(s, page, x, addr); |
2696 | |
2697 | } |
2698 | |
2699 | void kmem_cache_free(struct kmem_cache *s, void *x) |
2700 | { |
2701 | s = cache_from_obj(s, x); |
2702 | if (!s) |
2703 | return; |
2704 | slab_free(s, virt_to_head_page(x), x, _RET_IP_); |
2705 | trace_kmem_cache_free(_RET_IP_, x); |
2706 | } |
2707 | EXPORT_SYMBOL(kmem_cache_free); |
2708 | |
2709 | /* |
2710 | * Object placement in a slab is made very easy because we always start at |
2711 | * offset 0. If we tune the size of the object to the alignment then we can |
2712 | * get the required alignment by putting one properly sized object after |
2713 | * another. |
2714 | * |
2715 | * Notice that the allocation order determines the sizes of the per cpu |
2716 | * caches. Each processor has always one slab available for allocations. |
2717 | * Increasing the allocation order reduces the number of times that slabs |
2718 | * must be moved on and off the partial lists and is therefore a factor in |
2719 | * locking overhead. |
2720 | */ |
2721 | |
2722 | /* |
2723 | * Mininum / Maximum order of slab pages. This influences locking overhead |
2724 | * and slab fragmentation. A higher order reduces the number of partial slabs |
2725 | * and increases the number of allocations possible without having to |
2726 | * take the list_lock. |
2727 | */ |
2728 | static int slub_min_order; |
2729 | static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER; |
2730 | static int slub_min_objects; |
2731 | |
2732 | /* |
2733 | * Merge control. If this is set then no merging of slab caches will occur. |
2734 | * (Could be removed. This was introduced to pacify the merge skeptics.) |
2735 | */ |
2736 | static int slub_nomerge; |
2737 | |
2738 | /* |
2739 | * Calculate the order of allocation given an slab object size. |
2740 | * |
2741 | * The order of allocation has significant impact on performance and other |
2742 | * system components. Generally order 0 allocations should be preferred since |
2743 | * order 0 does not cause fragmentation in the page allocator. Larger objects |
2744 | * be problematic to put into order 0 slabs because there may be too much |
2745 | * unused space left. We go to a higher order if more than 1/16th of the slab |
2746 | * would be wasted. |
2747 | * |
2748 | * In order to reach satisfactory performance we must ensure that a minimum |
2749 | * number of objects is in one slab. Otherwise we may generate too much |
2750 | * activity on the partial lists which requires taking the list_lock. This is |
2751 | * less a concern for large slabs though which are rarely used. |
2752 | * |
2753 | * slub_max_order specifies the order where we begin to stop considering the |
2754 | * number of objects in a slab as critical. If we reach slub_max_order then |
2755 | * we try to keep the page order as low as possible. So we accept more waste |
2756 | * of space in favor of a small page order. |
2757 | * |
2758 | * Higher order allocations also allow the placement of more objects in a |
2759 | * slab and thereby reduce object handling overhead. If the user has |
2760 | * requested a higher mininum order then we start with that one instead of |
2761 | * the smallest order which will fit the object. |
2762 | */ |
2763 | static inline int slab_order(int size, int min_objects, |
2764 | int max_order, int fract_leftover, int reserved) |
2765 | { |
2766 | int order; |
2767 | int rem; |
2768 | int min_order = slub_min_order; |
2769 | |
2770 | if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE) |
2771 | return get_order(size * MAX_OBJS_PER_PAGE) - 1; |
2772 | |
2773 | for (order = max(min_order, |
2774 | fls(min_objects * size - 1) - PAGE_SHIFT); |
2775 | order <= max_order; order++) { |
2776 | |
2777 | unsigned long slab_size = PAGE_SIZE << order; |
2778 | |
2779 | if (slab_size < min_objects * size + reserved) |
2780 | continue; |
2781 | |
2782 | rem = (slab_size - reserved) % size; |
2783 | |
2784 | if (rem <= slab_size / fract_leftover) |
2785 | break; |
2786 | |
2787 | } |
2788 | |
2789 | return order; |
2790 | } |
2791 | |
2792 | static inline int calculate_order(int size, int reserved) |
2793 | { |
2794 | int order; |
2795 | int min_objects; |
2796 | int fraction; |
2797 | int max_objects; |
2798 | |
2799 | /* |
2800 | * Attempt to find best configuration for a slab. This |
2801 | * works by first attempting to generate a layout with |
2802 | * the best configuration and backing off gradually. |
2803 | * |
2804 | * First we reduce the acceptable waste in a slab. Then |
2805 | * we reduce the minimum objects required in a slab. |
2806 | */ |
2807 | min_objects = slub_min_objects; |
2808 | if (!min_objects) |
2809 | min_objects = 4 * (fls(nr_cpu_ids) + 1); |
2810 | max_objects = order_objects(slub_max_order, size, reserved); |
2811 | min_objects = min(min_objects, max_objects); |
2812 | |
2813 | while (min_objects > 1) { |
2814 | fraction = 16; |
2815 | while (fraction >= 4) { |
2816 | order = slab_order(size, min_objects, |
2817 | slub_max_order, fraction, reserved); |
2818 | if (order <= slub_max_order) |
2819 | return order; |
2820 | fraction /= 2; |
2821 | } |
2822 | min_objects--; |
2823 | } |
2824 | |
2825 | /* |
2826 | * We were unable to place multiple objects in a slab. Now |
2827 | * lets see if we can place a single object there. |
2828 | */ |
2829 | order = slab_order(size, 1, slub_max_order, 1, reserved); |
2830 | if (order <= slub_max_order) |
2831 | return order; |
2832 | |
2833 | /* |
2834 | * Doh this slab cannot be placed using slub_max_order. |
2835 | */ |
2836 | order = slab_order(size, 1, MAX_ORDER, 1, reserved); |
2837 | if (order < MAX_ORDER) |
2838 | return order; |
2839 | return -ENOSYS; |
2840 | } |
2841 | |
2842 | static void |
2843 | init_kmem_cache_node(struct kmem_cache_node *n) |
2844 | { |
2845 | n->nr_partial = 0; |
2846 | spin_lock_init(&n->list_lock); |
2847 | INIT_LIST_HEAD(&n->partial); |
2848 | #ifdef CONFIG_SLUB_DEBUG |
2849 | atomic_long_set(&n->nr_slabs, 0); |
2850 | atomic_long_set(&n->total_objects, 0); |
2851 | INIT_LIST_HEAD(&n->full); |
2852 | #endif |
2853 | } |
2854 | |
2855 | static inline int alloc_kmem_cache_cpus(struct kmem_cache *s) |
2856 | { |
2857 | BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE < |
2858 | KMALLOC_SHIFT_HIGH * sizeof(struct kmem_cache_cpu)); |
2859 | |
2860 | /* |
2861 | * Must align to double word boundary for the double cmpxchg |
2862 | * instructions to work; see __pcpu_double_call_return_bool(). |
2863 | */ |
2864 | s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu), |
2865 | 2 * sizeof(void *)); |
2866 | |
2867 | if (!s->cpu_slab) |
2868 | return 0; |
2869 | |
2870 | init_kmem_cache_cpus(s); |
2871 | |
2872 | return 1; |
2873 | } |
2874 | |
2875 | static struct kmem_cache *kmem_cache_node; |
2876 | |
2877 | /* |
2878 | * No kmalloc_node yet so do it by hand. We know that this is the first |
2879 | * slab on the node for this slabcache. There are no concurrent accesses |
2880 | * possible. |
2881 | * |
2882 | * Note that this function only works on the kmem_cache_node |
2883 | * when allocating for the kmem_cache_node. This is used for bootstrapping |
2884 | * memory on a fresh node that has no slab structures yet. |
2885 | */ |
2886 | static void early_kmem_cache_node_alloc(int node) |
2887 | { |
2888 | struct page *page; |
2889 | struct kmem_cache_node *n; |
2890 | |
2891 | BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node)); |
2892 | |
2893 | page = new_slab(kmem_cache_node, GFP_NOWAIT, node); |
2894 | |
2895 | BUG_ON(!page); |
2896 | if (page_to_nid(page) != node) { |
2897 | printk(KERN_ERR "SLUB: Unable to allocate memory from " |
2898 | "node %d\n", node); |
2899 | printk(KERN_ERR "SLUB: Allocating a useless per node structure " |
2900 | "in order to be able to continue\n"); |
2901 | } |
2902 | |
2903 | n = page->freelist; |
2904 | BUG_ON(!n); |
2905 | page->freelist = get_freepointer(kmem_cache_node, n); |
2906 | page->inuse = 1; |
2907 | page->frozen = 0; |
2908 | kmem_cache_node->node[node] = n; |
2909 | #ifdef CONFIG_SLUB_DEBUG |
2910 | init_object(kmem_cache_node, n, SLUB_RED_ACTIVE); |
2911 | init_tracking(kmem_cache_node, n); |
2912 | #endif |
2913 | init_kmem_cache_node(n); |
2914 | inc_slabs_node(kmem_cache_node, node, page->objects); |
2915 | |
2916 | /* |
2917 | * No locks need to be taken here as it has just been |
2918 | * initialized and there is no concurrent access. |
2919 | */ |
2920 | __add_partial(n, page, DEACTIVATE_TO_HEAD); |
2921 | } |
2922 | |
2923 | static void free_kmem_cache_nodes(struct kmem_cache *s) |
2924 | { |
2925 | int node; |
2926 | |
2927 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2928 | struct kmem_cache_node *n = s->node[node]; |
2929 | |
2930 | if (n) |
2931 | kmem_cache_free(kmem_cache_node, n); |
2932 | |
2933 | s->node[node] = NULL; |
2934 | } |
2935 | } |
2936 | |
2937 | static int init_kmem_cache_nodes(struct kmem_cache *s) |
2938 | { |
2939 | int node; |
2940 | |
2941 | for_each_node_state(node, N_NORMAL_MEMORY) { |
2942 | struct kmem_cache_node *n; |
2943 | |
2944 | if (slab_state == DOWN) { |
2945 | early_kmem_cache_node_alloc(node); |
2946 | continue; |
2947 | } |
2948 | n = kmem_cache_alloc_node(kmem_cache_node, |
2949 | GFP_KERNEL, node); |
2950 | |
2951 | if (!n) { |
2952 | free_kmem_cache_nodes(s); |
2953 | return 0; |
2954 | } |
2955 | |
2956 | s->node[node] = n; |
2957 | init_kmem_cache_node(n); |
2958 | } |
2959 | return 1; |
2960 | } |
2961 | |
2962 | static void set_min_partial(struct kmem_cache *s, unsigned long min) |
2963 | { |
2964 | if (min < MIN_PARTIAL) |
2965 | min = MIN_PARTIAL; |
2966 | else if (min > MAX_PARTIAL) |
2967 | min = MAX_PARTIAL; |
2968 | s->min_partial = min; |
2969 | } |
2970 | |
2971 | /* |
2972 | * calculate_sizes() determines the order and the distribution of data within |
2973 | * a slab object. |
2974 | */ |
2975 | static int calculate_sizes(struct kmem_cache *s, int forced_order) |
2976 | { |
2977 | unsigned long flags = s->flags; |
2978 | unsigned long size = s->object_size; |
2979 | int order; |
2980 | |
2981 | /* |
2982 | * Round up object size to the next word boundary. We can only |
2983 | * place the free pointer at word boundaries and this determines |
2984 | * the possible location of the free pointer. |
2985 | */ |
2986 | size = ALIGN(size, sizeof(void *)); |
2987 | |
2988 | #ifdef CONFIG_SLUB_DEBUG |
2989 | /* |
2990 | * Determine if we can poison the object itself. If the user of |
2991 | * the slab may touch the object after free or before allocation |
2992 | * then we should never poison the object itself. |
2993 | */ |
2994 | if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) && |
2995 | !s->ctor) |
2996 | s->flags |= __OBJECT_POISON; |
2997 | else |
2998 | s->flags &= ~__OBJECT_POISON; |
2999 | |
3000 | |
3001 | /* |
3002 | * If we are Redzoning then check if there is some space between the |
3003 | * end of the object and the free pointer. If not then add an |
3004 | * additional word to have some bytes to store Redzone information. |
3005 | */ |
3006 | if ((flags & SLAB_RED_ZONE) && size == s->object_size) |
3007 | size += sizeof(void *); |
3008 | #endif |
3009 | |
3010 | /* |
3011 | * With that we have determined the number of bytes in actual use |
3012 | * by the object. This is the potential offset to the free pointer. |
3013 | */ |
3014 | s->inuse = size; |
3015 | |
3016 | if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || |
3017 | s->ctor)) { |
3018 | /* |
3019 | * Relocate free pointer after the object if it is not |
3020 | * permitted to overwrite the first word of the object on |
3021 | * kmem_cache_free. |
3022 | * |
3023 | * This is the case if we do RCU, have a constructor or |
3024 | * destructor or are poisoning the objects. |
3025 | */ |
3026 | s->offset = size; |
3027 | size += sizeof(void *); |
3028 | } |
3029 | |
3030 | #ifdef CONFIG_SLUB_DEBUG |
3031 | if (flags & SLAB_STORE_USER) |
3032 | /* |
3033 | * Need to store information about allocs and frees after |
3034 | * the object. |
3035 | */ |
3036 | size += 2 * sizeof(struct track); |
3037 | |
3038 | if (flags & SLAB_RED_ZONE) |
3039 | /* |
3040 | * Add some empty padding so that we can catch |
3041 | * overwrites from earlier objects rather than let |
3042 | * tracking information or the free pointer be |
3043 | * corrupted if a user writes before the start |
3044 | * of the object. |
3045 | */ |
3046 | size += sizeof(void *); |
3047 | #endif |
3048 | |
3049 | /* |
3050 | * SLUB stores one object immediately after another beginning from |
3051 | * offset 0. In order to align the objects we have to simply size |
3052 | * each object to conform to the alignment. |
3053 | */ |
3054 | size = ALIGN(size, s->align); |
3055 | s->size = size; |
3056 | if (forced_order >= 0) |
3057 | order = forced_order; |
3058 | else |
3059 | order = calculate_order(size, s->reserved); |
3060 | |
3061 | if (order < 0) |
3062 | return 0; |
3063 | |
3064 | s->allocflags = 0; |
3065 | if (order) |
3066 | s->allocflags |= __GFP_COMP; |
3067 | |
3068 | if (s->flags & SLAB_CACHE_DMA) |
3069 | s->allocflags |= GFP_DMA; |
3070 | |
3071 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
3072 | s->allocflags |= __GFP_RECLAIMABLE; |
3073 | |
3074 | /* |
3075 | * Determine the number of objects per slab |
3076 | */ |
3077 | s->oo = oo_make(order, size, s->reserved); |
3078 | s->min = oo_make(get_order(size), size, s->reserved); |
3079 | if (oo_objects(s->oo) > oo_objects(s->max)) |
3080 | s->max = s->oo; |
3081 | |
3082 | return !!oo_objects(s->oo); |
3083 | } |
3084 | |
3085 | static int kmem_cache_open(struct kmem_cache *s, unsigned long flags) |
3086 | { |
3087 | s->flags = kmem_cache_flags(s->size, flags, s->name, s->ctor); |
3088 | s->reserved = 0; |
3089 | |
3090 | if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU)) |
3091 | s->reserved = sizeof(struct rcu_head); |
3092 | |
3093 | if (!calculate_sizes(s, -1)) |
3094 | goto error; |
3095 | if (disable_higher_order_debug) { |
3096 | /* |
3097 | * Disable debugging flags that store metadata if the min slab |
3098 | * order increased. |
3099 | */ |
3100 | if (get_order(s->size) > get_order(s->object_size)) { |
3101 | s->flags &= ~DEBUG_METADATA_FLAGS; |
3102 | s->offset = 0; |
3103 | if (!calculate_sizes(s, -1)) |
3104 | goto error; |
3105 | } |
3106 | } |
3107 | |
3108 | #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ |
3109 | defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) |
3110 | if (system_has_cmpxchg_double() && (s->flags & SLAB_DEBUG_FLAGS) == 0) |
3111 | /* Enable fast mode */ |
3112 | s->flags |= __CMPXCHG_DOUBLE; |
3113 | #endif |
3114 | |
3115 | /* |
3116 | * The larger the object size is, the more pages we want on the partial |
3117 | * list to avoid pounding the page allocator excessively. |
3118 | */ |
3119 | set_min_partial(s, ilog2(s->size) / 2); |
3120 | |
3121 | /* |
3122 | * cpu_partial determined the maximum number of objects kept in the |
3123 | * per cpu partial lists of a processor. |
3124 | * |
3125 | * Per cpu partial lists mainly contain slabs that just have one |
3126 | * object freed. If they are used for allocation then they can be |
3127 | * filled up again with minimal effort. The slab will never hit the |
3128 | * per node partial lists and therefore no locking will be required. |
3129 | * |
3130 | * This setting also determines |
3131 | * |
3132 | * A) The number of objects from per cpu partial slabs dumped to the |
3133 | * per node list when we reach the limit. |
3134 | * B) The number of objects in cpu partial slabs to extract from the |
3135 | * per node list when we run out of per cpu objects. We only fetch |
3136 | * 50% to keep some capacity around for frees. |
3137 | */ |
3138 | if (!kmem_cache_has_cpu_partial(s)) |
3139 | s->cpu_partial = 0; |
3140 | else if (s->size >= PAGE_SIZE) |
3141 | s->cpu_partial = 2; |
3142 | else if (s->size >= 1024) |
3143 | s->cpu_partial = 6; |
3144 | else if (s->size >= 256) |
3145 | s->cpu_partial = 13; |
3146 | else |
3147 | s->cpu_partial = 30; |
3148 | |
3149 | #ifdef CONFIG_NUMA |
3150 | s->remote_node_defrag_ratio = 1000; |
3151 | #endif |
3152 | if (!init_kmem_cache_nodes(s)) |
3153 | goto error; |
3154 | |
3155 | if (alloc_kmem_cache_cpus(s)) |
3156 | return 0; |
3157 | |
3158 | free_kmem_cache_nodes(s); |
3159 | error: |
3160 | if (flags & SLAB_PANIC) |
3161 | panic("Cannot create slab %s size=%lu realsize=%u " |
3162 | "order=%u offset=%u flags=%lx\n", |
3163 | s->name, (unsigned long)s->size, s->size, |
3164 | oo_order(s->oo), s->offset, flags); |
3165 | return -EINVAL; |
3166 | } |
3167 | |
3168 | static void list_slab_objects(struct kmem_cache *s, struct page *page, |
3169 | const char *text) |
3170 | { |
3171 | #ifdef CONFIG_SLUB_DEBUG |
3172 | void *addr = page_address(page); |
3173 | void *p; |
3174 | unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) * |
3175 | sizeof(long), GFP_ATOMIC); |
3176 | if (!map) |
3177 | return; |
3178 | slab_err(s, page, text, s->name); |
3179 | slab_lock(page); |
3180 | |
3181 | get_map(s, page, map); |
3182 | for_each_object(p, s, addr, page->objects) { |
3183 | |
3184 | if (!test_bit(slab_index(p, s, addr), map)) { |
3185 | printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n", |
3186 | p, p - addr); |
3187 | print_tracking(s, p); |
3188 | } |
3189 | } |
3190 | slab_unlock(page); |
3191 | kfree(map); |
3192 | #endif |
3193 | } |
3194 | |
3195 | /* |
3196 | * Attempt to free all partial slabs on a node. |
3197 | * This is called from kmem_cache_close(). We must be the last thread |
3198 | * using the cache and therefore we do not need to lock anymore. |
3199 | */ |
3200 | static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) |
3201 | { |
3202 | struct page *page, *h; |
3203 | |
3204 | list_for_each_entry_safe(page, h, &n->partial, lru) { |
3205 | if (!page->inuse) { |
3206 | __remove_partial(n, page); |
3207 | discard_slab(s, page); |
3208 | } else { |
3209 | list_slab_objects(s, page, |
3210 | "Objects remaining in %s on kmem_cache_close()"); |
3211 | } |
3212 | } |
3213 | } |
3214 | |
3215 | /* |
3216 | * Release all resources used by a slab cache. |
3217 | */ |
3218 | static inline int kmem_cache_close(struct kmem_cache *s) |
3219 | { |
3220 | int node; |
3221 | |
3222 | flush_all(s); |
3223 | /* Attempt to free all objects */ |
3224 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3225 | struct kmem_cache_node *n = get_node(s, node); |
3226 | |
3227 | free_partial(s, n); |
3228 | if (n->nr_partial || slabs_node(s, node)) |
3229 | return 1; |
3230 | } |
3231 | free_percpu(s->cpu_slab); |
3232 | free_kmem_cache_nodes(s); |
3233 | return 0; |
3234 | } |
3235 | |
3236 | int __kmem_cache_shutdown(struct kmem_cache *s) |
3237 | { |
3238 | return kmem_cache_close(s); |
3239 | } |
3240 | |
3241 | /******************************************************************** |
3242 | * Kmalloc subsystem |
3243 | *******************************************************************/ |
3244 | |
3245 | static int __init setup_slub_min_order(char *str) |
3246 | { |
3247 | get_option(&str, &slub_min_order); |
3248 | |
3249 | return 1; |
3250 | } |
3251 | |
3252 | __setup("slub_min_order=", setup_slub_min_order); |
3253 | |
3254 | static int __init setup_slub_max_order(char *str) |
3255 | { |
3256 | get_option(&str, &slub_max_order); |
3257 | slub_max_order = min(slub_max_order, MAX_ORDER - 1); |
3258 | |
3259 | return 1; |
3260 | } |
3261 | |
3262 | __setup("slub_max_order=", setup_slub_max_order); |
3263 | |
3264 | static int __init setup_slub_min_objects(char *str) |
3265 | { |
3266 | get_option(&str, &slub_min_objects); |
3267 | |
3268 | return 1; |
3269 | } |
3270 | |
3271 | __setup("slub_min_objects=", setup_slub_min_objects); |
3272 | |
3273 | static int __init setup_slub_nomerge(char *str) |
3274 | { |
3275 | slub_nomerge = 1; |
3276 | return 1; |
3277 | } |
3278 | |
3279 | __setup("slub_nomerge", setup_slub_nomerge); |
3280 | |
3281 | void *__kmalloc(size_t size, gfp_t flags) |
3282 | { |
3283 | struct kmem_cache *s; |
3284 | void *ret; |
3285 | |
3286 | if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) |
3287 | return kmalloc_large(size, flags); |
3288 | |
3289 | s = kmalloc_slab(size, flags); |
3290 | |
3291 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3292 | return s; |
3293 | |
3294 | ret = slab_alloc(s, flags, _RET_IP_); |
3295 | |
3296 | trace_kmalloc(_RET_IP_, ret, size, s->size, flags); |
3297 | |
3298 | return ret; |
3299 | } |
3300 | EXPORT_SYMBOL(__kmalloc); |
3301 | |
3302 | #ifdef CONFIG_NUMA |
3303 | static void *kmalloc_large_node(size_t size, gfp_t flags, int node) |
3304 | { |
3305 | struct page *page; |
3306 | void *ptr = NULL; |
3307 | |
3308 | flags |= __GFP_COMP | __GFP_NOTRACK | __GFP_KMEMCG; |
3309 | page = alloc_pages_node(node, flags, get_order(size)); |
3310 | if (page) |
3311 | ptr = page_address(page); |
3312 | |
3313 | kmalloc_large_node_hook(ptr, size, flags); |
3314 | return ptr; |
3315 | } |
3316 | |
3317 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3318 | { |
3319 | struct kmem_cache *s; |
3320 | void *ret; |
3321 | |
3322 | if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) { |
3323 | ret = kmalloc_large_node(size, flags, node); |
3324 | |
3325 | trace_kmalloc_node(_RET_IP_, ret, |
3326 | size, PAGE_SIZE << get_order(size), |
3327 | flags, node); |
3328 | |
3329 | return ret; |
3330 | } |
3331 | |
3332 | s = kmalloc_slab(size, flags); |
3333 | |
3334 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3335 | return s; |
3336 | |
3337 | ret = slab_alloc_node(s, flags, node, _RET_IP_); |
3338 | |
3339 | trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node); |
3340 | |
3341 | return ret; |
3342 | } |
3343 | EXPORT_SYMBOL(__kmalloc_node); |
3344 | #endif |
3345 | |
3346 | size_t ksize(const void *object) |
3347 | { |
3348 | struct page *page; |
3349 | |
3350 | if (unlikely(object == ZERO_SIZE_PTR)) |
3351 | return 0; |
3352 | |
3353 | page = virt_to_head_page(object); |
3354 | |
3355 | if (unlikely(!PageSlab(page))) { |
3356 | WARN_ON(!PageCompound(page)); |
3357 | return PAGE_SIZE << compound_order(page); |
3358 | } |
3359 | |
3360 | return slab_ksize(page->slab_cache); |
3361 | } |
3362 | EXPORT_SYMBOL(ksize); |
3363 | |
3364 | void kfree(const void *x) |
3365 | { |
3366 | struct page *page; |
3367 | void *object = (void *)x; |
3368 | |
3369 | trace_kfree(_RET_IP_, x); |
3370 | |
3371 | if (unlikely(ZERO_OR_NULL_PTR(x))) |
3372 | return; |
3373 | |
3374 | page = virt_to_head_page(x); |
3375 | if (unlikely(!PageSlab(page))) { |
3376 | BUG_ON(!PageCompound(page)); |
3377 | kfree_hook(x); |
3378 | __free_memcg_kmem_pages(page, compound_order(page)); |
3379 | return; |
3380 | } |
3381 | slab_free(page->slab_cache, page, object, _RET_IP_); |
3382 | } |
3383 | EXPORT_SYMBOL(kfree); |
3384 | |
3385 | /* |
3386 | * kmem_cache_shrink removes empty slabs from the partial lists and sorts |
3387 | * the remaining slabs by the number of items in use. The slabs with the |
3388 | * most items in use come first. New allocations will then fill those up |
3389 | * and thus they can be removed from the partial lists. |
3390 | * |
3391 | * The slabs with the least items are placed last. This results in them |
3392 | * being allocated from last increasing the chance that the last objects |
3393 | * are freed in them. |
3394 | */ |
3395 | int kmem_cache_shrink(struct kmem_cache *s) |
3396 | { |
3397 | int node; |
3398 | int i; |
3399 | struct kmem_cache_node *n; |
3400 | struct page *page; |
3401 | struct page *t; |
3402 | int objects = oo_objects(s->max); |
3403 | struct list_head *slabs_by_inuse = |
3404 | kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL); |
3405 | unsigned long flags; |
3406 | |
3407 | if (!slabs_by_inuse) |
3408 | return -ENOMEM; |
3409 | |
3410 | flush_all(s); |
3411 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3412 | n = get_node(s, node); |
3413 | |
3414 | if (!n->nr_partial) |
3415 | continue; |
3416 | |
3417 | for (i = 0; i < objects; i++) |
3418 | INIT_LIST_HEAD(slabs_by_inuse + i); |
3419 | |
3420 | spin_lock_irqsave(&n->list_lock, flags); |
3421 | |
3422 | /* |
3423 | * Build lists indexed by the items in use in each slab. |
3424 | * |
3425 | * Note that concurrent frees may occur while we hold the |
3426 | * list_lock. page->inuse here is the upper limit. |
3427 | */ |
3428 | list_for_each_entry_safe(page, t, &n->partial, lru) { |
3429 | list_move(&page->lru, slabs_by_inuse + page->inuse); |
3430 | if (!page->inuse) |
3431 | n->nr_partial--; |
3432 | } |
3433 | |
3434 | /* |
3435 | * Rebuild the partial list with the slabs filled up most |
3436 | * first and the least used slabs at the end. |
3437 | */ |
3438 | for (i = objects - 1; i > 0; i--) |
3439 | list_splice(slabs_by_inuse + i, n->partial.prev); |
3440 | |
3441 | spin_unlock_irqrestore(&n->list_lock, flags); |
3442 | |
3443 | /* Release empty slabs */ |
3444 | list_for_each_entry_safe(page, t, slabs_by_inuse, lru) |
3445 | discard_slab(s, page); |
3446 | } |
3447 | |
3448 | kfree(slabs_by_inuse); |
3449 | return 0; |
3450 | } |
3451 | EXPORT_SYMBOL(kmem_cache_shrink); |
3452 | |
3453 | static int slab_mem_going_offline_callback(void *arg) |
3454 | { |
3455 | struct kmem_cache *s; |
3456 | |
3457 | mutex_lock(&slab_mutex); |
3458 | list_for_each_entry(s, &slab_caches, list) |
3459 | kmem_cache_shrink(s); |
3460 | mutex_unlock(&slab_mutex); |
3461 | |
3462 | return 0; |
3463 | } |
3464 | |
3465 | static void slab_mem_offline_callback(void *arg) |
3466 | { |
3467 | struct kmem_cache_node *n; |
3468 | struct kmem_cache *s; |
3469 | struct memory_notify *marg = arg; |
3470 | int offline_node; |
3471 | |
3472 | offline_node = marg->status_change_nid_normal; |
3473 | |
3474 | /* |
3475 | * If the node still has available memory. we need kmem_cache_node |
3476 | * for it yet. |
3477 | */ |
3478 | if (offline_node < 0) |
3479 | return; |
3480 | |
3481 | mutex_lock(&slab_mutex); |
3482 | list_for_each_entry(s, &slab_caches, list) { |
3483 | n = get_node(s, offline_node); |
3484 | if (n) { |
3485 | /* |
3486 | * if n->nr_slabs > 0, slabs still exist on the node |
3487 | * that is going down. We were unable to free them, |
3488 | * and offline_pages() function shouldn't call this |
3489 | * callback. So, we must fail. |
3490 | */ |
3491 | BUG_ON(slabs_node(s, offline_node)); |
3492 | |
3493 | s->node[offline_node] = NULL; |
3494 | kmem_cache_free(kmem_cache_node, n); |
3495 | } |
3496 | } |
3497 | mutex_unlock(&slab_mutex); |
3498 | } |
3499 | |
3500 | static int slab_mem_going_online_callback(void *arg) |
3501 | { |
3502 | struct kmem_cache_node *n; |
3503 | struct kmem_cache *s; |
3504 | struct memory_notify *marg = arg; |
3505 | int nid = marg->status_change_nid_normal; |
3506 | int ret = 0; |
3507 | |
3508 | /* |
3509 | * If the node's memory is already available, then kmem_cache_node is |
3510 | * already created. Nothing to do. |
3511 | */ |
3512 | if (nid < 0) |
3513 | return 0; |
3514 | |
3515 | /* |
3516 | * We are bringing a node online. No memory is available yet. We must |
3517 | * allocate a kmem_cache_node structure in order to bring the node |
3518 | * online. |
3519 | */ |
3520 | mutex_lock(&slab_mutex); |
3521 | list_for_each_entry(s, &slab_caches, list) { |
3522 | /* |
3523 | * XXX: kmem_cache_alloc_node will fallback to other nodes |
3524 | * since memory is not yet available from the node that |
3525 | * is brought up. |
3526 | */ |
3527 | n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL); |
3528 | if (!n) { |
3529 | ret = -ENOMEM; |
3530 | goto out; |
3531 | } |
3532 | init_kmem_cache_node(n); |
3533 | s->node[nid] = n; |
3534 | } |
3535 | out: |
3536 | mutex_unlock(&slab_mutex); |
3537 | return ret; |
3538 | } |
3539 | |
3540 | static int slab_memory_callback(struct notifier_block *self, |
3541 | unsigned long action, void *arg) |
3542 | { |
3543 | int ret = 0; |
3544 | |
3545 | switch (action) { |
3546 | case MEM_GOING_ONLINE: |
3547 | ret = slab_mem_going_online_callback(arg); |
3548 | break; |
3549 | case MEM_GOING_OFFLINE: |
3550 | ret = slab_mem_going_offline_callback(arg); |
3551 | break; |
3552 | case MEM_OFFLINE: |
3553 | case MEM_CANCEL_ONLINE: |
3554 | slab_mem_offline_callback(arg); |
3555 | break; |
3556 | case MEM_ONLINE: |
3557 | case MEM_CANCEL_OFFLINE: |
3558 | break; |
3559 | } |
3560 | if (ret) |
3561 | ret = notifier_from_errno(ret); |
3562 | else |
3563 | ret = NOTIFY_OK; |
3564 | return ret; |
3565 | } |
3566 | |
3567 | static struct notifier_block slab_memory_callback_nb = { |
3568 | .notifier_call = slab_memory_callback, |
3569 | .priority = SLAB_CALLBACK_PRI, |
3570 | }; |
3571 | |
3572 | /******************************************************************** |
3573 | * Basic setup of slabs |
3574 | *******************************************************************/ |
3575 | |
3576 | /* |
3577 | * Used for early kmem_cache structures that were allocated using |
3578 | * the page allocator. Allocate them properly then fix up the pointers |
3579 | * that may be pointing to the wrong kmem_cache structure. |
3580 | */ |
3581 | |
3582 | static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache) |
3583 | { |
3584 | int node; |
3585 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); |
3586 | |
3587 | memcpy(s, static_cache, kmem_cache->object_size); |
3588 | |
3589 | /* |
3590 | * This runs very early, and only the boot processor is supposed to be |
3591 | * up. Even if it weren't true, IRQs are not up so we couldn't fire |
3592 | * IPIs around. |
3593 | */ |
3594 | __flush_cpu_slab(s, smp_processor_id()); |
3595 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3596 | struct kmem_cache_node *n = get_node(s, node); |
3597 | struct page *p; |
3598 | |
3599 | if (n) { |
3600 | list_for_each_entry(p, &n->partial, lru) |
3601 | p->slab_cache = s; |
3602 | |
3603 | #ifdef CONFIG_SLUB_DEBUG |
3604 | list_for_each_entry(p, &n->full, lru) |
3605 | p->slab_cache = s; |
3606 | #endif |
3607 | } |
3608 | } |
3609 | list_add(&s->list, &slab_caches); |
3610 | return s; |
3611 | } |
3612 | |
3613 | void __init kmem_cache_init(void) |
3614 | { |
3615 | static __initdata struct kmem_cache boot_kmem_cache, |
3616 | boot_kmem_cache_node; |
3617 | |
3618 | if (debug_guardpage_minorder()) |
3619 | slub_max_order = 0; |
3620 | |
3621 | kmem_cache_node = &boot_kmem_cache_node; |
3622 | kmem_cache = &boot_kmem_cache; |
3623 | |
3624 | create_boot_cache(kmem_cache_node, "kmem_cache_node", |
3625 | sizeof(struct kmem_cache_node), SLAB_HWCACHE_ALIGN); |
3626 | |
3627 | register_hotmemory_notifier(&slab_memory_callback_nb); |
3628 | |
3629 | /* Able to allocate the per node structures */ |
3630 | slab_state = PARTIAL; |
3631 | |
3632 | create_boot_cache(kmem_cache, "kmem_cache", |
3633 | offsetof(struct kmem_cache, node) + |
3634 | nr_node_ids * sizeof(struct kmem_cache_node *), |
3635 | SLAB_HWCACHE_ALIGN); |
3636 | |
3637 | kmem_cache = bootstrap(&boot_kmem_cache); |
3638 | |
3639 | /* |
3640 | * Allocate kmem_cache_node properly from the kmem_cache slab. |
3641 | * kmem_cache_node is separately allocated so no need to |
3642 | * update any list pointers. |
3643 | */ |
3644 | kmem_cache_node = bootstrap(&boot_kmem_cache_node); |
3645 | |
3646 | /* Now we can use the kmem_cache to allocate kmalloc slabs */ |
3647 | create_kmalloc_caches(0); |
3648 | |
3649 | #ifdef CONFIG_SMP |
3650 | register_cpu_notifier(&slab_notifier); |
3651 | #endif |
3652 | |
3653 | printk(KERN_INFO |
3654 | "SLUB: HWalign=%d, Order=%d-%d, MinObjects=%d," |
3655 | " CPUs=%d, Nodes=%d\n", |
3656 | cache_line_size(), |
3657 | slub_min_order, slub_max_order, slub_min_objects, |
3658 | nr_cpu_ids, nr_node_ids); |
3659 | } |
3660 | |
3661 | void __init kmem_cache_init_late(void) |
3662 | { |
3663 | } |
3664 | |
3665 | /* |
3666 | * Find a mergeable slab cache |
3667 | */ |
3668 | static int slab_unmergeable(struct kmem_cache *s) |
3669 | { |
3670 | if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) |
3671 | return 1; |
3672 | |
3673 | if (!is_root_cache(s)) |
3674 | return 1; |
3675 | |
3676 | if (s->ctor) |
3677 | return 1; |
3678 | |
3679 | /* |
3680 | * We may have set a slab to be unmergeable during bootstrap. |
3681 | */ |
3682 | if (s->refcount < 0) |
3683 | return 1; |
3684 | |
3685 | return 0; |
3686 | } |
3687 | |
3688 | static struct kmem_cache *find_mergeable(size_t size, size_t align, |
3689 | unsigned long flags, const char *name, void (*ctor)(void *)) |
3690 | { |
3691 | struct kmem_cache *s; |
3692 | |
3693 | if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) |
3694 | return NULL; |
3695 | |
3696 | if (ctor) |
3697 | return NULL; |
3698 | |
3699 | size = ALIGN(size, sizeof(void *)); |
3700 | align = calculate_alignment(flags, align, size); |
3701 | size = ALIGN(size, align); |
3702 | flags = kmem_cache_flags(size, flags, name, NULL); |
3703 | |
3704 | list_for_each_entry(s, &slab_caches, list) { |
3705 | if (slab_unmergeable(s)) |
3706 | continue; |
3707 | |
3708 | if (size > s->size) |
3709 | continue; |
3710 | |
3711 | if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME)) |
3712 | continue; |
3713 | /* |
3714 | * Check if alignment is compatible. |
3715 | * Courtesy of Adrian Drzewiecki |
3716 | */ |
3717 | if ((s->size & ~(align - 1)) != s->size) |
3718 | continue; |
3719 | |
3720 | if (s->size - size >= sizeof(void *)) |
3721 | continue; |
3722 | |
3723 | return s; |
3724 | } |
3725 | return NULL; |
3726 | } |
3727 | |
3728 | struct kmem_cache * |
3729 | __kmem_cache_alias(const char *name, size_t size, size_t align, |
3730 | unsigned long flags, void (*ctor)(void *)) |
3731 | { |
3732 | struct kmem_cache *s; |
3733 | |
3734 | s = find_mergeable(size, align, flags, name, ctor); |
3735 | if (s) { |
3736 | int i; |
3737 | struct kmem_cache *c; |
3738 | |
3739 | s->refcount++; |
3740 | |
3741 | /* |
3742 | * Adjust the object sizes so that we clear |
3743 | * the complete object on kzalloc. |
3744 | */ |
3745 | s->object_size = max(s->object_size, (int)size); |
3746 | s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *))); |
3747 | |
3748 | for_each_memcg_cache_index(i) { |
3749 | c = cache_from_memcg_idx(s, i); |
3750 | if (!c) |
3751 | continue; |
3752 | c->object_size = s->object_size; |
3753 | c->inuse = max_t(int, c->inuse, |
3754 | ALIGN(size, sizeof(void *))); |
3755 | } |
3756 | |
3757 | if (sysfs_slab_alias(s, name)) { |
3758 | s->refcount--; |
3759 | s = NULL; |
3760 | } |
3761 | } |
3762 | |
3763 | return s; |
3764 | } |
3765 | |
3766 | int __kmem_cache_create(struct kmem_cache *s, unsigned long flags) |
3767 | { |
3768 | int err; |
3769 | |
3770 | err = kmem_cache_open(s, flags); |
3771 | if (err) |
3772 | return err; |
3773 | |
3774 | /* Mutex is not taken during early boot */ |
3775 | if (slab_state <= UP) |
3776 | return 0; |
3777 | |
3778 | memcg_propagate_slab_attrs(s); |
3779 | err = sysfs_slab_add(s); |
3780 | if (err) |
3781 | kmem_cache_close(s); |
3782 | |
3783 | return err; |
3784 | } |
3785 | |
3786 | #ifdef CONFIG_SMP |
3787 | /* |
3788 | * Use the cpu notifier to insure that the cpu slabs are flushed when |
3789 | * necessary. |
3790 | */ |
3791 | static int slab_cpuup_callback(struct notifier_block *nfb, |
3792 | unsigned long action, void *hcpu) |
3793 | { |
3794 | long cpu = (long)hcpu; |
3795 | struct kmem_cache *s; |
3796 | unsigned long flags; |
3797 | |
3798 | switch (action) { |
3799 | case CPU_UP_CANCELED: |
3800 | case CPU_UP_CANCELED_FROZEN: |
3801 | case CPU_DEAD: |
3802 | case CPU_DEAD_FROZEN: |
3803 | mutex_lock(&slab_mutex); |
3804 | list_for_each_entry(s, &slab_caches, list) { |
3805 | local_irq_save(flags); |
3806 | __flush_cpu_slab(s, cpu); |
3807 | local_irq_restore(flags); |
3808 | } |
3809 | mutex_unlock(&slab_mutex); |
3810 | break; |
3811 | default: |
3812 | break; |
3813 | } |
3814 | return NOTIFY_OK; |
3815 | } |
3816 | |
3817 | static struct notifier_block slab_notifier = { |
3818 | .notifier_call = slab_cpuup_callback |
3819 | }; |
3820 | |
3821 | #endif |
3822 | |
3823 | void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller) |
3824 | { |
3825 | struct kmem_cache *s; |
3826 | void *ret; |
3827 | |
3828 | if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) |
3829 | return kmalloc_large(size, gfpflags); |
3830 | |
3831 | s = kmalloc_slab(size, gfpflags); |
3832 | |
3833 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3834 | return s; |
3835 | |
3836 | ret = slab_alloc(s, gfpflags, caller); |
3837 | |
3838 | /* Honor the call site pointer we received. */ |
3839 | trace_kmalloc(caller, ret, size, s->size, gfpflags); |
3840 | |
3841 | return ret; |
3842 | } |
3843 | |
3844 | #ifdef CONFIG_NUMA |
3845 | void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, |
3846 | int node, unsigned long caller) |
3847 | { |
3848 | struct kmem_cache *s; |
3849 | void *ret; |
3850 | |
3851 | if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) { |
3852 | ret = kmalloc_large_node(size, gfpflags, node); |
3853 | |
3854 | trace_kmalloc_node(caller, ret, |
3855 | size, PAGE_SIZE << get_order(size), |
3856 | gfpflags, node); |
3857 | |
3858 | return ret; |
3859 | } |
3860 | |
3861 | s = kmalloc_slab(size, gfpflags); |
3862 | |
3863 | if (unlikely(ZERO_OR_NULL_PTR(s))) |
3864 | return s; |
3865 | |
3866 | ret = slab_alloc_node(s, gfpflags, node, caller); |
3867 | |
3868 | /* Honor the call site pointer we received. */ |
3869 | trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node); |
3870 | |
3871 | return ret; |
3872 | } |
3873 | #endif |
3874 | |
3875 | #ifdef CONFIG_SYSFS |
3876 | static int count_inuse(struct page *page) |
3877 | { |
3878 | return page->inuse; |
3879 | } |
3880 | |
3881 | static int count_total(struct page *page) |
3882 | { |
3883 | return page->objects; |
3884 | } |
3885 | #endif |
3886 | |
3887 | #ifdef CONFIG_SLUB_DEBUG |
3888 | static int validate_slab(struct kmem_cache *s, struct page *page, |
3889 | unsigned long *map) |
3890 | { |
3891 | void *p; |
3892 | void *addr = page_address(page); |
3893 | |
3894 | if (!check_slab(s, page) || |
3895 | !on_freelist(s, page, NULL)) |
3896 | return 0; |
3897 | |
3898 | /* Now we know that a valid freelist exists */ |
3899 | bitmap_zero(map, page->objects); |
3900 | |
3901 | get_map(s, page, map); |
3902 | for_each_object(p, s, addr, page->objects) { |
3903 | if (test_bit(slab_index(p, s, addr), map)) |
3904 | if (!check_object(s, page, p, SLUB_RED_INACTIVE)) |
3905 | return 0; |
3906 | } |
3907 | |
3908 | for_each_object(p, s, addr, page->objects) |
3909 | if (!test_bit(slab_index(p, s, addr), map)) |
3910 | if (!check_object(s, page, p, SLUB_RED_ACTIVE)) |
3911 | return 0; |
3912 | return 1; |
3913 | } |
3914 | |
3915 | static void validate_slab_slab(struct kmem_cache *s, struct page *page, |
3916 | unsigned long *map) |
3917 | { |
3918 | slab_lock(page); |
3919 | validate_slab(s, page, map); |
3920 | slab_unlock(page); |
3921 | } |
3922 | |
3923 | static int validate_slab_node(struct kmem_cache *s, |
3924 | struct kmem_cache_node *n, unsigned long *map) |
3925 | { |
3926 | unsigned long count = 0; |
3927 | struct page *page; |
3928 | unsigned long flags; |
3929 | |
3930 | spin_lock_irqsave(&n->list_lock, flags); |
3931 | |
3932 | list_for_each_entry(page, &n->partial, lru) { |
3933 | validate_slab_slab(s, page, map); |
3934 | count++; |
3935 | } |
3936 | if (count != n->nr_partial) |
3937 | printk(KERN_ERR "SLUB %s: %ld partial slabs counted but " |
3938 | "counter=%ld\n", s->name, count, n->nr_partial); |
3939 | |
3940 | if (!(s->flags & SLAB_STORE_USER)) |
3941 | goto out; |
3942 | |
3943 | list_for_each_entry(page, &n->full, lru) { |
3944 | validate_slab_slab(s, page, map); |
3945 | count++; |
3946 | } |
3947 | if (count != atomic_long_read(&n->nr_slabs)) |
3948 | printk(KERN_ERR "SLUB: %s %ld slabs counted but " |
3949 | "counter=%ld\n", s->name, count, |
3950 | atomic_long_read(&n->nr_slabs)); |
3951 | |
3952 | out: |
3953 | spin_unlock_irqrestore(&n->list_lock, flags); |
3954 | return count; |
3955 | } |
3956 | |
3957 | static long validate_slab_cache(struct kmem_cache *s) |
3958 | { |
3959 | int node; |
3960 | unsigned long count = 0; |
3961 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * |
3962 | sizeof(unsigned long), GFP_KERNEL); |
3963 | |
3964 | if (!map) |
3965 | return -ENOMEM; |
3966 | |
3967 | flush_all(s); |
3968 | for_each_node_state(node, N_NORMAL_MEMORY) { |
3969 | struct kmem_cache_node *n = get_node(s, node); |
3970 | |
3971 | count += validate_slab_node(s, n, map); |
3972 | } |
3973 | kfree(map); |
3974 | return count; |
3975 | } |
3976 | /* |
3977 | * Generate lists of code addresses where slabcache objects are allocated |
3978 | * and freed. |
3979 | */ |
3980 | |
3981 | struct location { |
3982 | unsigned long count; |
3983 | unsigned long addr; |
3984 | long long sum_time; |
3985 | long min_time; |
3986 | long max_time; |
3987 | long min_pid; |
3988 | long max_pid; |
3989 | DECLARE_BITMAP(cpus, NR_CPUS); |
3990 | nodemask_t nodes; |
3991 | }; |
3992 | |
3993 | struct loc_track { |
3994 | unsigned long max; |
3995 | unsigned long count; |
3996 | struct location *loc; |
3997 | }; |
3998 | |
3999 | static void free_loc_track(struct loc_track *t) |
4000 | { |
4001 | if (t->max) |
4002 | free_pages((unsigned long)t->loc, |
4003 | get_order(sizeof(struct location) * t->max)); |
4004 | } |
4005 | |
4006 | static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags) |
4007 | { |
4008 | struct location *l; |
4009 | int order; |
4010 | |
4011 | order = get_order(sizeof(struct location) * max); |
4012 | |
4013 | l = (void *)__get_free_pages(flags, order); |
4014 | if (!l) |
4015 | return 0; |
4016 | |
4017 | if (t->count) { |
4018 | memcpy(l, t->loc, sizeof(struct location) * t->count); |
4019 | free_loc_track(t); |
4020 | } |
4021 | t->max = max; |
4022 | t->loc = l; |
4023 | return 1; |
4024 | } |
4025 | |
4026 | static int add_location(struct loc_track *t, struct kmem_cache *s, |
4027 | const struct track *track) |
4028 | { |
4029 | long start, end, pos; |
4030 | struct location *l; |
4031 | unsigned long caddr; |
4032 | unsigned long age = jiffies - track->when; |
4033 | |
4034 | start = -1; |
4035 | end = t->count; |
4036 | |
4037 | for ( ; ; ) { |
4038 | pos = start + (end - start + 1) / 2; |
4039 | |
4040 | /* |
4041 | * There is nothing at "end". If we end up there |
4042 | * we need to add something to before end. |
4043 | */ |
4044 | if (pos == end) |
4045 | break; |
4046 | |
4047 | caddr = t->loc[pos].addr; |
4048 | if (track->addr == caddr) { |
4049 | |
4050 | l = &t->loc[pos]; |
4051 | l->count++; |
4052 | if (track->when) { |
4053 | l->sum_time += age; |
4054 | if (age < l->min_time) |
4055 | l->min_time = age; |
4056 | if (age > l->max_time) |
4057 | l->max_time = age; |
4058 | |
4059 | if (track->pid < l->min_pid) |
4060 | l->min_pid = track->pid; |
4061 | if (track->pid > l->max_pid) |
4062 | l->max_pid = track->pid; |
4063 | |
4064 | cpumask_set_cpu(track->cpu, |
4065 | to_cpumask(l->cpus)); |
4066 | } |
4067 | node_set(page_to_nid(virt_to_page(track)), l->nodes); |
4068 | return 1; |
4069 | } |
4070 | |
4071 | if (track->addr < caddr) |
4072 | end = pos; |
4073 | else |
4074 | start = pos; |
4075 | } |
4076 | |
4077 | /* |
4078 | * Not found. Insert new tracking element. |
4079 | */ |
4080 | if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC)) |
4081 | return 0; |
4082 | |
4083 | l = t->loc + pos; |
4084 | if (pos < t->count) |
4085 | memmove(l + 1, l, |
4086 | (t->count - pos) * sizeof(struct location)); |
4087 | t->count++; |
4088 | l->count = 1; |
4089 | l->addr = track->addr; |
4090 | l->sum_time = age; |
4091 | l->min_time = age; |
4092 | l->max_time = age; |
4093 | l->min_pid = track->pid; |
4094 | l->max_pid = track->pid; |
4095 | cpumask_clear(to_cpumask(l->cpus)); |
4096 | cpumask_set_cpu(track->cpu, to_cpumask(l->cpus)); |
4097 | nodes_clear(l->nodes); |
4098 | node_set(page_to_nid(virt_to_page(track)), l->nodes); |
4099 | return 1; |
4100 | } |
4101 | |
4102 | static void process_slab(struct loc_track *t, struct kmem_cache *s, |
4103 | struct page *page, enum track_item alloc, |
4104 | unsigned long *map) |
4105 | { |
4106 | void *addr = page_address(page); |
4107 | void *p; |
4108 | |
4109 | bitmap_zero(map, page->objects); |
4110 | get_map(s, page, map); |
4111 | |
4112 | for_each_object(p, s, addr, page->objects) |
4113 | if (!test_bit(slab_index(p, s, addr), map)) |
4114 | add_location(t, s, get_track(s, p, alloc)); |
4115 | } |
4116 | |
4117 | static int list_locations(struct kmem_cache *s, char *buf, |
4118 | enum track_item alloc) |
4119 | { |
4120 | int len = 0; |
4121 | unsigned long i; |
4122 | struct loc_track t = { 0, 0, NULL }; |
4123 | int node; |
4124 | unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) * |
4125 | sizeof(unsigned long), GFP_KERNEL); |
4126 | |
4127 | if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), |
4128 | GFP_TEMPORARY)) { |
4129 | kfree(map); |
4130 | return sprintf(buf, "Out of memory\n"); |
4131 | } |
4132 | /* Push back cpu slabs */ |
4133 | flush_all(s); |
4134 | |
4135 | for_each_node_state(node, N_NORMAL_MEMORY) { |
4136 | struct kmem_cache_node *n = get_node(s, node); |
4137 | unsigned long flags; |
4138 | struct page *page; |
4139 | |
4140 | if (!atomic_long_read(&n->nr_slabs)) |
4141 | continue; |
4142 | |
4143 | spin_lock_irqsave(&n->list_lock, flags); |
4144 | list_for_each_entry(page, &n->partial, lru) |
4145 | process_slab(&t, s, page, alloc, map); |
4146 | list_for_each_entry(page, &n->full, lru) |
4147 | process_slab(&t, s, page, alloc, map); |
4148 | spin_unlock_irqrestore(&n->list_lock, flags); |
4149 | } |
4150 | |
4151 | for (i = 0; i < t.count; i++) { |
4152 | struct location *l = &t.loc[i]; |
4153 | |
4154 | if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100) |
4155 | break; |
4156 | len += sprintf(buf + len, "%7ld ", l->count); |
4157 | |
4158 | if (l->addr) |
4159 | len += sprintf(buf + len, "%pS", (void *)l->addr); |
4160 | else |
4161 | len += sprintf(buf + len, "<not-available>"); |
4162 | |
4163 | if (l->sum_time != l->min_time) { |
4164 | len += sprintf(buf + len, " age=%ld/%ld/%ld", |
4165 | l->min_time, |
4166 | (long)div_u64(l->sum_time, l->count), |
4167 | l->max_time); |
4168 | } else |
4169 | len += sprintf(buf + len, " age=%ld", |
4170 | l->min_time); |
4171 | |
4172 | if (l->min_pid != l->max_pid) |
4173 | len += sprintf(buf + len, " pid=%ld-%ld", |
4174 | l->min_pid, l->max_pid); |
4175 | else |
4176 | len += sprintf(buf + len, " pid=%ld", |
4177 | l->min_pid); |
4178 | |
4179 | if (num_online_cpus() > 1 && |
4180 | !cpumask_empty(to_cpumask(l->cpus)) && |
4181 | len < PAGE_SIZE - 60) { |
4182 | len += sprintf(buf + len, " cpus="); |
4183 | len += cpulist_scnprintf(buf + len, |
4184 | PAGE_SIZE - len - 50, |
4185 | to_cpumask(l->cpus)); |
4186 | } |
4187 | |
4188 | if (nr_online_nodes > 1 && !nodes_empty(l->nodes) && |
4189 | len < PAGE_SIZE - 60) { |
4190 | len += sprintf(buf + len, " nodes="); |
4191 | len += nodelist_scnprintf(buf + len, |
4192 | PAGE_SIZE - len - 50, |
4193 | l->nodes); |
4194 | } |
4195 | |
4196 | len += sprintf(buf + len, "\n"); |
4197 | } |
4198 | |
4199 | free_loc_track(&t); |
4200 | kfree(map); |
4201 | if (!t.count) |
4202 | len += sprintf(buf, "No data\n"); |
4203 | return len; |
4204 | } |
4205 | #endif |
4206 | |
4207 | #ifdef SLUB_RESILIENCY_TEST |
4208 | static void resiliency_test(void) |
4209 | { |
4210 | u8 *p; |
4211 | |
4212 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || KMALLOC_SHIFT_HIGH < 10); |
4213 | |
4214 | printk(KERN_ERR "SLUB resiliency testing\n"); |
4215 | printk(KERN_ERR "-----------------------\n"); |
4216 | printk(KERN_ERR "A. Corruption after allocation\n"); |
4217 | |
4218 | p = kzalloc(16, GFP_KERNEL); |
4219 | p[16] = 0x12; |
4220 | printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer" |
4221 | " 0x12->0x%p\n\n", p + 16); |
4222 | |
4223 | validate_slab_cache(kmalloc_caches[4]); |
4224 | |
4225 | /* Hmmm... The next two are dangerous */ |
4226 | p = kzalloc(32, GFP_KERNEL); |
4227 | p[32 + sizeof(void *)] = 0x34; |
4228 | printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab" |
4229 | " 0x34 -> -0x%p\n", p); |
4230 | printk(KERN_ERR |
4231 | "If allocated object is overwritten then not detectable\n\n"); |
4232 | |
4233 | validate_slab_cache(kmalloc_caches[5]); |
4234 | p = kzalloc(64, GFP_KERNEL); |
4235 | p += 64 + (get_cycles() & 0xff) * sizeof(void *); |
4236 | *p = 0x56; |
4237 | printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n", |
4238 | p); |
4239 | printk(KERN_ERR |
4240 | "If allocated object is overwritten then not detectable\n\n"); |
4241 | validate_slab_cache(kmalloc_caches[6]); |
4242 | |
4243 | printk(KERN_ERR "\nB. Corruption after free\n"); |
4244 | p = kzalloc(128, GFP_KERNEL); |
4245 | kfree(p); |
4246 | *p = 0x78; |
4247 | printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p); |
4248 | validate_slab_cache(kmalloc_caches[7]); |
4249 | |
4250 | p = kzalloc(256, GFP_KERNEL); |
4251 | kfree(p); |
4252 | p[50] = 0x9a; |
4253 | printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", |
4254 | p); |
4255 | validate_slab_cache(kmalloc_caches[8]); |
4256 | |
4257 | p = kzalloc(512, GFP_KERNEL); |
4258 | kfree(p); |
4259 | p[512] = 0xab; |
4260 | printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p); |
4261 | validate_slab_cache(kmalloc_caches[9]); |
4262 | } |
4263 | #else |
4264 | #ifdef CONFIG_SYSFS |
4265 | static void resiliency_test(void) {}; |
4266 | #endif |
4267 | #endif |
4268 | |
4269 | #ifdef CONFIG_SYSFS |
4270 | enum slab_stat_type { |
4271 | SL_ALL, /* All slabs */ |
4272 | SL_PARTIAL, /* Only partially allocated slabs */ |
4273 | SL_CPU, /* Only slabs used for cpu caches */ |
4274 | SL_OBJECTS, /* Determine allocated objects not slabs */ |
4275 | SL_TOTAL /* Determine object capacity not slabs */ |
4276 | }; |
4277 | |
4278 | #define SO_ALL (1 << SL_ALL) |
4279 | #define SO_PARTIAL (1 << SL_PARTIAL) |
4280 | #define SO_CPU (1 << SL_CPU) |
4281 | #define SO_OBJECTS (1 << SL_OBJECTS) |
4282 | #define SO_TOTAL (1 << SL_TOTAL) |
4283 | |
4284 | static ssize_t show_slab_objects(struct kmem_cache *s, |
4285 | char *buf, unsigned long flags) |
4286 | { |
4287 | unsigned long total = 0; |
4288 | int node; |
4289 | int x; |
4290 | unsigned long *nodes; |
4291 | |
4292 | nodes = kzalloc(sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); |
4293 | if (!nodes) |
4294 | return -ENOMEM; |
4295 | |
4296 | if (flags & SO_CPU) { |
4297 | int cpu; |
4298 | |
4299 | for_each_possible_cpu(cpu) { |
4300 | struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, |
4301 | cpu); |
4302 | int node; |
4303 | struct page *page; |
4304 | |
4305 | page = ACCESS_ONCE(c->page); |
4306 | if (!page) |
4307 | continue; |
4308 | |
4309 | node = page_to_nid(page); |
4310 | if (flags & SO_TOTAL) |
4311 | x = page->objects; |
4312 | else if (flags & SO_OBJECTS) |
4313 | x = page->inuse; |
4314 | else |
4315 | x = 1; |
4316 | |
4317 | total += x; |
4318 | nodes[node] += x; |
4319 | |
4320 | page = ACCESS_ONCE(c->partial); |
4321 | if (page) { |
4322 | node = page_to_nid(page); |
4323 | if (flags & SO_TOTAL) |
4324 | WARN_ON_ONCE(1); |
4325 | else if (flags & SO_OBJECTS) |
4326 | WARN_ON_ONCE(1); |
4327 | else |
4328 | x = page->pages; |
4329 | total += x; |
4330 | nodes[node] += x; |
4331 | } |
4332 | } |
4333 | } |
4334 | |
4335 | lock_memory_hotplug(); |
4336 | #ifdef CONFIG_SLUB_DEBUG |
4337 | if (flags & SO_ALL) { |
4338 | for_each_node_state(node, N_NORMAL_MEMORY) { |
4339 | struct kmem_cache_node *n = get_node(s, node); |
4340 | |
4341 | if (flags & SO_TOTAL) |
4342 | x = atomic_long_read(&n->total_objects); |
4343 | else if (flags & SO_OBJECTS) |
4344 | x = atomic_long_read(&n->total_objects) - |
4345 | count_partial(n, count_free); |
4346 | else |
4347 | x = atomic_long_read(&n->nr_slabs); |
4348 | total += x; |
4349 | nodes[node] += x; |
4350 | } |
4351 | |
4352 | } else |
4353 | #endif |
4354 | if (flags & SO_PARTIAL) { |
4355 | for_each_node_state(node, N_NORMAL_MEMORY) { |
4356 | struct kmem_cache_node *n = get_node(s, node); |
4357 | |
4358 | if (flags & SO_TOTAL) |
4359 | x = count_partial(n, count_total); |
4360 | else if (flags & SO_OBJECTS) |
4361 | x = count_partial(n, count_inuse); |
4362 | else |
4363 | x = n->nr_partial; |
4364 | total += x; |
4365 | nodes[node] += x; |
4366 | } |
4367 | } |
4368 | x = sprintf(buf, "%lu", total); |
4369 | #ifdef CONFIG_NUMA |
4370 | for_each_node_state(node, N_NORMAL_MEMORY) |
4371 | if (nodes[node]) |
4372 | x += sprintf(buf + x, " N%d=%lu", |
4373 | node, nodes[node]); |
4374 | #endif |
4375 | unlock_memory_hotplug(); |
4376 | kfree(nodes); |
4377 | return x + sprintf(buf + x, "\n"); |
4378 | } |
4379 | |
4380 | #ifdef CONFIG_SLUB_DEBUG |
4381 | static int any_slab_objects(struct kmem_cache *s) |
4382 | { |
4383 | int node; |
4384 | |
4385 | for_each_online_node(node) { |
4386 | struct kmem_cache_node *n = get_node(s, node); |
4387 | |
4388 | if (!n) |
4389 | continue; |
4390 | |
4391 | if (atomic_long_read(&n->total_objects)) |
4392 | return 1; |
4393 | } |
4394 | return 0; |
4395 | } |
4396 | #endif |
4397 | |
4398 | #define to_slab_attr(n) container_of(n, struct slab_attribute, attr) |
4399 | #define to_slab(n) container_of(n, struct kmem_cache, kobj) |
4400 | |
4401 | struct slab_attribute { |
4402 | struct attribute attr; |
4403 | ssize_t (*show)(struct kmem_cache *s, char *buf); |
4404 | ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); |
4405 | }; |
4406 | |
4407 | #define SLAB_ATTR_RO(_name) \ |
4408 | static struct slab_attribute _name##_attr = \ |
4409 | __ATTR(_name, 0400, _name##_show, NULL) |
4410 | |
4411 | #define SLAB_ATTR(_name) \ |
4412 | static struct slab_attribute _name##_attr = \ |
4413 | __ATTR(_name, 0600, _name##_show, _name##_store) |
4414 | |
4415 | static ssize_t slab_size_show(struct kmem_cache *s, char *buf) |
4416 | { |
4417 | return sprintf(buf, "%d\n", s->size); |
4418 | } |
4419 | SLAB_ATTR_RO(slab_size); |
4420 | |
4421 | static ssize_t align_show(struct kmem_cache *s, char *buf) |
4422 | { |
4423 | return sprintf(buf, "%d\n", s->align); |
4424 | } |
4425 | SLAB_ATTR_RO(align); |
4426 | |
4427 | static ssize_t object_size_show(struct kmem_cache *s, char *buf) |
4428 | { |
4429 | return sprintf(buf, "%d\n", s->object_size); |
4430 | } |
4431 | SLAB_ATTR_RO(object_size); |
4432 | |
4433 | static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf) |
4434 | { |
4435 | return sprintf(buf, "%d\n", oo_objects(s->oo)); |
4436 | } |
4437 | SLAB_ATTR_RO(objs_per_slab); |
4438 | |
4439 | static ssize_t order_store(struct kmem_cache *s, |
4440 | const char *buf, size_t length) |
4441 | { |
4442 | unsigned long order; |
4443 | int err; |
4444 | |
4445 | err = kstrtoul(buf, 10, &order); |
4446 | if (err) |
4447 | return err; |
4448 | |
4449 | if (order > slub_max_order || order < slub_min_order) |
4450 | return -EINVAL; |
4451 | |
4452 | calculate_sizes(s, order); |
4453 | return length; |
4454 | } |
4455 | |
4456 | static ssize_t order_show(struct kmem_cache *s, char *buf) |
4457 | { |
4458 | return sprintf(buf, "%d\n", oo_order(s->oo)); |
4459 | } |
4460 | SLAB_ATTR(order); |
4461 | |
4462 | static ssize_t min_partial_show(struct kmem_cache *s, char *buf) |
4463 | { |
4464 | return sprintf(buf, "%lu\n", s->min_partial); |
4465 | } |
4466 | |
4467 | static ssize_t min_partial_store(struct kmem_cache *s, const char *buf, |
4468 | size_t length) |
4469 | { |
4470 | unsigned long min; |
4471 | int err; |
4472 | |
4473 | err = kstrtoul(buf, 10, &min); |
4474 | if (err) |
4475 | return err; |
4476 | |
4477 | set_min_partial(s, min); |
4478 | return length; |
4479 | } |
4480 | SLAB_ATTR(min_partial); |
4481 | |
4482 | static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf) |
4483 | { |
4484 | return sprintf(buf, "%u\n", s->cpu_partial); |
4485 | } |
4486 | |
4487 | static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf, |
4488 | size_t length) |
4489 | { |
4490 | unsigned long objects; |
4491 | int err; |
4492 | |
4493 | err = kstrtoul(buf, 10, &objects); |
4494 | if (err) |
4495 | return err; |
4496 | if (objects && !kmem_cache_has_cpu_partial(s)) |
4497 | return -EINVAL; |
4498 | |
4499 | s->cpu_partial = objects; |
4500 | flush_all(s); |
4501 | return length; |
4502 | } |
4503 | SLAB_ATTR(cpu_partial); |
4504 | |
4505 | static ssize_t ctor_show(struct kmem_cache *s, char *buf) |
4506 | { |
4507 | if (!s->ctor) |
4508 | return 0; |
4509 | return sprintf(buf, "%pS\n", s->ctor); |
4510 | } |
4511 | SLAB_ATTR_RO(ctor); |
4512 | |
4513 | static ssize_t aliases_show(struct kmem_cache *s, char *buf) |
4514 | { |
4515 | return sprintf(buf, "%d\n", s->refcount - 1); |
4516 | } |
4517 | SLAB_ATTR_RO(aliases); |
4518 | |
4519 | static ssize_t partial_show(struct kmem_cache *s, char *buf) |
4520 | { |
4521 | return show_slab_objects(s, buf, SO_PARTIAL); |
4522 | } |
4523 | SLAB_ATTR_RO(partial); |
4524 | |
4525 | static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) |
4526 | { |
4527 | return show_slab_objects(s, buf, SO_CPU); |
4528 | } |
4529 | SLAB_ATTR_RO(cpu_slabs); |
4530 | |
4531 | static ssize_t objects_show(struct kmem_cache *s, char *buf) |
4532 | { |
4533 | return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS); |
4534 | } |
4535 | SLAB_ATTR_RO(objects); |
4536 | |
4537 | static ssize_t objects_partial_show(struct kmem_cache *s, char *buf) |
4538 | { |
4539 | return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS); |
4540 | } |
4541 | SLAB_ATTR_RO(objects_partial); |
4542 | |
4543 | static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf) |
4544 | { |
4545 | int objects = 0; |
4546 | int pages = 0; |
4547 | int cpu; |
4548 | int len; |
4549 | |
4550 | for_each_online_cpu(cpu) { |
4551 | struct page *page = per_cpu_ptr(s->cpu_slab, cpu)->partial; |
4552 | |
4553 | if (page) { |
4554 | pages += page->pages; |
4555 | objects += page->pobjects; |
4556 | } |
4557 | } |
4558 | |
4559 | len = sprintf(buf, "%d(%d)", objects, pages); |
4560 | |
4561 | #ifdef CONFIG_SMP |
4562 | for_each_online_cpu(cpu) { |
4563 | struct page *page = per_cpu_ptr(s->cpu_slab, cpu) ->partial; |
4564 | |
4565 | if (page && len < PAGE_SIZE - 20) |
4566 | len += sprintf(buf + len, " C%d=%d(%d)", cpu, |
4567 | page->pobjects, page->pages); |
4568 | } |
4569 | #endif |
4570 | return len + sprintf(buf + len, "\n"); |
4571 | } |
4572 | SLAB_ATTR_RO(slabs_cpu_partial); |
4573 | |
4574 | static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) |
4575 | { |
4576 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); |
4577 | } |
4578 | |
4579 | static ssize_t reclaim_account_store(struct kmem_cache *s, |
4580 | const char *buf, size_t length) |
4581 | { |
4582 | s->flags &= ~SLAB_RECLAIM_ACCOUNT; |
4583 | if (buf[0] == '1') |
4584 | s->flags |= SLAB_RECLAIM_ACCOUNT; |
4585 | return length; |
4586 | } |
4587 | SLAB_ATTR(reclaim_account); |
4588 | |
4589 | static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) |
4590 | { |
4591 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN)); |
4592 | } |
4593 | SLAB_ATTR_RO(hwcache_align); |
4594 | |
4595 | #ifdef CONFIG_ZONE_DMA |
4596 | static ssize_t cache_dma_show(struct kmem_cache *s, char *buf) |
4597 | { |
4598 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA)); |
4599 | } |
4600 | SLAB_ATTR_RO(cache_dma); |
4601 | #endif |
4602 | |
4603 | static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) |
4604 | { |
4605 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU)); |
4606 | } |
4607 | SLAB_ATTR_RO(destroy_by_rcu); |
4608 | |
4609 | static ssize_t reserved_show(struct kmem_cache *s, char *buf) |
4610 | { |
4611 | return sprintf(buf, "%d\n", s->reserved); |
4612 | } |
4613 | SLAB_ATTR_RO(reserved); |
4614 | |
4615 | #ifdef CONFIG_SLUB_DEBUG |
4616 | static ssize_t slabs_show(struct kmem_cache *s, char *buf) |
4617 | { |
4618 | return show_slab_objects(s, buf, SO_ALL); |
4619 | } |
4620 | SLAB_ATTR_RO(slabs); |
4621 | |
4622 | static ssize_t total_objects_show(struct kmem_cache *s, char *buf) |
4623 | { |
4624 | return show_slab_objects(s, buf, SO_ALL|SO_TOTAL); |
4625 | } |
4626 | SLAB_ATTR_RO(total_objects); |
4627 | |
4628 | static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf) |
4629 | { |
4630 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE)); |
4631 | } |
4632 | |
4633 | static ssize_t sanity_checks_store(struct kmem_cache *s, |
4634 | const char *buf, size_t length) |
4635 | { |
4636 | s->flags &= ~SLAB_DEBUG_FREE; |
4637 | if (buf[0] == '1') { |
4638 | s->flags &= ~__CMPXCHG_DOUBLE; |
4639 | s->flags |= SLAB_DEBUG_FREE; |
4640 | } |
4641 | return length; |
4642 | } |
4643 | SLAB_ATTR(sanity_checks); |
4644 | |
4645 | static ssize_t trace_show(struct kmem_cache *s, char *buf) |
4646 | { |
4647 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE)); |
4648 | } |
4649 | |
4650 | static ssize_t trace_store(struct kmem_cache *s, const char *buf, |
4651 | size_t length) |
4652 | { |
4653 | s->flags &= ~SLAB_TRACE; |
4654 | if (buf[0] == '1') { |
4655 | s->flags &= ~__CMPXCHG_DOUBLE; |
4656 | s->flags |= SLAB_TRACE; |
4657 | } |
4658 | return length; |
4659 | } |
4660 | SLAB_ATTR(trace); |
4661 | |
4662 | static ssize_t red_zone_show(struct kmem_cache *s, char *buf) |
4663 | { |
4664 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE)); |
4665 | } |
4666 | |
4667 | static ssize_t red_zone_store(struct kmem_cache *s, |
4668 | const char *buf, size_t length) |
4669 | { |
4670 | if (any_slab_objects(s)) |
4671 | return -EBUSY; |
4672 | |
4673 | s->flags &= ~SLAB_RED_ZONE; |
4674 | if (buf[0] == '1') { |
4675 | s->flags &= ~__CMPXCHG_DOUBLE; |
4676 | s->flags |= SLAB_RED_ZONE; |
4677 | } |
4678 | calculate_sizes(s, -1); |
4679 | return length; |
4680 | } |
4681 | SLAB_ATTR(red_zone); |
4682 | |
4683 | static ssize_t poison_show(struct kmem_cache *s, char *buf) |
4684 | { |
4685 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON)); |
4686 | } |
4687 | |
4688 | static ssize_t poison_store(struct kmem_cache *s, |
4689 | const char *buf, size_t length) |
4690 | { |
4691 | if (any_slab_objects(s)) |
4692 | return -EBUSY; |
4693 | |
4694 | s->flags &= ~SLAB_POISON; |
4695 | if (buf[0] == '1') { |
4696 | s->flags &= ~__CMPXCHG_DOUBLE; |
4697 | s->flags |= SLAB_POISON; |
4698 | } |
4699 | calculate_sizes(s, -1); |
4700 | return length; |
4701 | } |
4702 | SLAB_ATTR(poison); |
4703 | |
4704 | static ssize_t store_user_show(struct kmem_cache *s, char *buf) |
4705 | { |
4706 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER)); |
4707 | } |
4708 | |
4709 | static ssize_t store_user_store(struct kmem_cache *s, |
4710 | const char *buf, size_t length) |
4711 | { |
4712 | if (any_slab_objects(s)) |
4713 | return -EBUSY; |
4714 | |
4715 | s->flags &= ~SLAB_STORE_USER; |
4716 | if (buf[0] == '1') { |
4717 | s->flags &= ~__CMPXCHG_DOUBLE; |
4718 | s->flags |= SLAB_STORE_USER; |
4719 | } |
4720 | calculate_sizes(s, -1); |
4721 | return length; |
4722 | } |
4723 | SLAB_ATTR(store_user); |
4724 | |
4725 | static ssize_t validate_show(struct kmem_cache *s, char *buf) |
4726 | { |
4727 | return 0; |
4728 | } |
4729 | |
4730 | static ssize_t validate_store(struct kmem_cache *s, |
4731 | const char *buf, size_t length) |
4732 | { |
4733 | int ret = -EINVAL; |
4734 | |
4735 | if (buf[0] == '1') { |
4736 | ret = validate_slab_cache(s); |
4737 | if (ret >= 0) |
4738 | ret = length; |
4739 | } |
4740 | return ret; |
4741 | } |
4742 | SLAB_ATTR(validate); |
4743 | |
4744 | static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) |
4745 | { |
4746 | if (!(s->flags & SLAB_STORE_USER)) |
4747 | return -ENOSYS; |
4748 | return list_locations(s, buf, TRACK_ALLOC); |
4749 | } |
4750 | SLAB_ATTR_RO(alloc_calls); |
4751 | |
4752 | static ssize_t free_calls_show(struct kmem_cache *s, char *buf) |
4753 | { |
4754 | if (!(s->flags & SLAB_STORE_USER)) |
4755 | return -ENOSYS; |
4756 | return list_locations(s, buf, TRACK_FREE); |
4757 | } |
4758 | SLAB_ATTR_RO(free_calls); |
4759 | #endif /* CONFIG_SLUB_DEBUG */ |
4760 | |
4761 | #ifdef CONFIG_FAILSLAB |
4762 | static ssize_t failslab_show(struct kmem_cache *s, char *buf) |
4763 | { |
4764 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB)); |
4765 | } |
4766 | |
4767 | static ssize_t failslab_store(struct kmem_cache *s, const char *buf, |
4768 | size_t length) |
4769 | { |
4770 | s->flags &= ~SLAB_FAILSLAB; |
4771 | if (buf[0] == '1') |
4772 | s->flags |= SLAB_FAILSLAB; |
4773 | return length; |
4774 | } |
4775 | SLAB_ATTR(failslab); |
4776 | #endif |
4777 | |
4778 | static ssize_t shrink_show(struct kmem_cache *s, char *buf) |
4779 | { |
4780 | return 0; |
4781 | } |
4782 | |
4783 | static ssize_t shrink_store(struct kmem_cache *s, |
4784 | const char *buf, size_t length) |
4785 | { |
4786 | if (buf[0] == '1') { |
4787 | int rc = kmem_cache_shrink(s); |
4788 | |
4789 | if (rc) |
4790 | return rc; |
4791 | } else |
4792 | return -EINVAL; |
4793 | return length; |
4794 | } |
4795 | SLAB_ATTR(shrink); |
4796 | |
4797 | #ifdef CONFIG_NUMA |
4798 | static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf) |
4799 | { |
4800 | return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10); |
4801 | } |
4802 | |
4803 | static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s, |
4804 | const char *buf, size_t length) |
4805 | { |
4806 | unsigned long ratio; |
4807 | int err; |
4808 | |
4809 | err = kstrtoul(buf, 10, &ratio); |
4810 | if (err) |
4811 | return err; |
4812 | |
4813 | if (ratio <= 100) |
4814 | s->remote_node_defrag_ratio = ratio * 10; |
4815 | |
4816 | return length; |
4817 | } |
4818 | SLAB_ATTR(remote_node_defrag_ratio); |
4819 | #endif |
4820 | |
4821 | #ifdef CONFIG_SLUB_STATS |
4822 | static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si) |
4823 | { |
4824 | unsigned long sum = 0; |
4825 | int cpu; |
4826 | int len; |
4827 | int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL); |
4828 | |
4829 | if (!data) |
4830 | return -ENOMEM; |
4831 | |
4832 | for_each_online_cpu(cpu) { |
4833 | unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si]; |
4834 | |
4835 | data[cpu] = x; |
4836 | sum += x; |
4837 | } |
4838 | |
4839 | len = sprintf(buf, "%lu", sum); |
4840 | |
4841 | #ifdef CONFIG_SMP |
4842 | for_each_online_cpu(cpu) { |
4843 | if (data[cpu] && len < PAGE_SIZE - 20) |
4844 | len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]); |
4845 | } |
4846 | #endif |
4847 | kfree(data); |
4848 | return len + sprintf(buf + len, "\n"); |
4849 | } |
4850 | |
4851 | static void clear_stat(struct kmem_cache *s, enum stat_item si) |
4852 | { |
4853 | int cpu; |
4854 | |
4855 | for_each_online_cpu(cpu) |
4856 | per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0; |
4857 | } |
4858 | |
4859 | #define STAT_ATTR(si, text) \ |
4860 | static ssize_t text##_show(struct kmem_cache *s, char *buf) \ |
4861 | { \ |
4862 | return show_stat(s, buf, si); \ |
4863 | } \ |
4864 | static ssize_t text##_store(struct kmem_cache *s, \ |
4865 | const char *buf, size_t length) \ |
4866 | { \ |
4867 | if (buf[0] != '0') \ |
4868 | return -EINVAL; \ |
4869 | clear_stat(s, si); \ |
4870 | return length; \ |
4871 | } \ |
4872 | SLAB_ATTR(text); \ |
4873 | |
4874 | STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath); |
4875 | STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath); |
4876 | STAT_ATTR(FREE_FASTPATH, free_fastpath); |
4877 | STAT_ATTR(FREE_SLOWPATH, free_slowpath); |
4878 | STAT_ATTR(FREE_FROZEN, free_frozen); |
4879 | STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial); |
4880 | STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial); |
4881 | STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial); |
4882 | STAT_ATTR(ALLOC_SLAB, alloc_slab); |
4883 | STAT_ATTR(ALLOC_REFILL, alloc_refill); |
4884 | STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch); |
4885 | STAT_ATTR(FREE_SLAB, free_slab); |
4886 | STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush); |
4887 | STAT_ATTR(DEACTIVATE_FULL, deactivate_full); |
4888 | STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty); |
4889 | STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head); |
4890 | STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail); |
4891 | STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees); |
4892 | STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass); |
4893 | STAT_ATTR(ORDER_FALLBACK, order_fallback); |
4894 | STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail); |
4895 | STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail); |
4896 | STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc); |
4897 | STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free); |
4898 | STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node); |
4899 | STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain); |
4900 | #endif |
4901 | |
4902 | static struct attribute *slab_attrs[] = { |
4903 | &slab_size_attr.attr, |
4904 | &object_size_attr.attr, |
4905 | &objs_per_slab_attr.attr, |
4906 | &order_attr.attr, |
4907 | &min_partial_attr.attr, |
4908 | &cpu_partial_attr.attr, |
4909 | &objects_attr.attr, |
4910 | &objects_partial_attr.attr, |
4911 | &partial_attr.attr, |
4912 | &cpu_slabs_attr.attr, |
4913 | &ctor_attr.attr, |
4914 | &aliases_attr.attr, |
4915 | &align_attr.attr, |
4916 | &hwcache_align_attr.attr, |
4917 | &reclaim_account_attr.attr, |
4918 | &destroy_by_rcu_attr.attr, |
4919 | &shrink_attr.attr, |
4920 | &reserved_attr.attr, |
4921 | &slabs_cpu_partial_attr.attr, |
4922 | #ifdef CONFIG_SLUB_DEBUG |
4923 | &total_objects_attr.attr, |
4924 | &slabs_attr.attr, |
4925 | &sanity_checks_attr.attr, |
4926 | &trace_attr.attr, |
4927 | &red_zone_attr.attr, |
4928 | &poison_attr.attr, |
4929 | &store_user_attr.attr, |
4930 | &validate_attr.attr, |
4931 | &alloc_calls_attr.attr, |
4932 | &free_calls_attr.attr, |
4933 | #endif |
4934 | #ifdef CONFIG_ZONE_DMA |
4935 | &cache_dma_attr.attr, |
4936 | #endif |
4937 | #ifdef CONFIG_NUMA |
4938 | &remote_node_defrag_ratio_attr.attr, |
4939 | #endif |
4940 | #ifdef CONFIG_SLUB_STATS |
4941 | &alloc_fastpath_attr.attr, |
4942 | &alloc_slowpath_attr.attr, |
4943 | &free_fastpath_attr.attr, |
4944 | &free_slowpath_attr.attr, |
4945 | &free_frozen_attr.attr, |
4946 | &free_add_partial_attr.attr, |
4947 | &free_remove_partial_attr.attr, |
4948 | &alloc_from_partial_attr.attr, |
4949 | &alloc_slab_attr.attr, |
4950 | &alloc_refill_attr.attr, |
4951 | &alloc_node_mismatch_attr.attr, |
4952 | &free_slab_attr.attr, |
4953 | &cpuslab_flush_attr.attr, |
4954 | &deactivate_full_attr.attr, |
4955 | &deactivate_empty_attr.attr, |
4956 | &deactivate_to_head_attr.attr, |
4957 | &deactivate_to_tail_attr.attr, |
4958 | &deactivate_remote_frees_attr.attr, |
4959 | &deactivate_bypass_attr.attr, |
4960 | &order_fallback_attr.attr, |
4961 | &cmpxchg_double_fail_attr.attr, |
4962 | &cmpxchg_double_cpu_fail_attr.attr, |
4963 | &cpu_partial_alloc_attr.attr, |
4964 | &cpu_partial_free_attr.attr, |
4965 | &cpu_partial_node_attr.attr, |
4966 | &cpu_partial_drain_attr.attr, |
4967 | #endif |
4968 | #ifdef CONFIG_FAILSLAB |
4969 | &failslab_attr.attr, |
4970 | #endif |
4971 | |
4972 | NULL |
4973 | }; |
4974 | |
4975 | static struct attribute_group slab_attr_group = { |
4976 | .attrs = slab_attrs, |
4977 | }; |
4978 | |
4979 | static ssize_t slab_attr_show(struct kobject *kobj, |
4980 | struct attribute *attr, |
4981 | char *buf) |
4982 | { |
4983 | struct slab_attribute *attribute; |
4984 | struct kmem_cache *s; |
4985 | int err; |
4986 | |
4987 | attribute = to_slab_attr(attr); |
4988 | s = to_slab(kobj); |
4989 | |
4990 | if (!attribute->show) |
4991 | return -EIO; |
4992 | |
4993 | err = attribute->show(s, buf); |
4994 | |
4995 | return err; |
4996 | } |
4997 | |
4998 | static ssize_t slab_attr_store(struct kobject *kobj, |
4999 | struct attribute *attr, |
5000 | const char *buf, size_t len) |
5001 | { |
5002 | struct slab_attribute *attribute; |
5003 | struct kmem_cache *s; |
5004 | int err; |
5005 | |
5006 | attribute = to_slab_attr(attr); |
5007 | s = to_slab(kobj); |
5008 | |
5009 | if (!attribute->store) |
5010 | return -EIO; |
5011 | |
5012 | err = attribute->store(s, buf, len); |
5013 | #ifdef CONFIG_MEMCG_KMEM |
5014 | if (slab_state >= FULL && err >= 0 && is_root_cache(s)) { |
5015 | int i; |
5016 | |
5017 | mutex_lock(&slab_mutex); |
5018 | if (s->max_attr_size < len) |
5019 | s->max_attr_size = len; |
5020 | |
5021 | /* |
5022 | * This is a best effort propagation, so this function's return |
5023 | * value will be determined by the parent cache only. This is |
5024 | * basically because not all attributes will have a well |
5025 | * defined semantics for rollbacks - most of the actions will |
5026 | * have permanent effects. |
5027 | * |
5028 | * Returning the error value of any of the children that fail |
5029 | * is not 100 % defined, in the sense that users seeing the |
5030 | * error code won't be able to know anything about the state of |
5031 | * the cache. |
5032 | * |
5033 | * Only returning the error code for the parent cache at least |
5034 | * has well defined semantics. The cache being written to |
5035 | * directly either failed or succeeded, in which case we loop |
5036 | * through the descendants with best-effort propagation. |
5037 | */ |
5038 | for_each_memcg_cache_index(i) { |
5039 | struct kmem_cache *c = cache_from_memcg_idx(s, i); |
5040 | if (c) |
5041 | attribute->store(c, buf, len); |
5042 | } |
5043 | mutex_unlock(&slab_mutex); |
5044 | } |
5045 | #endif |
5046 | return err; |
5047 | } |
5048 | |
5049 | static void memcg_propagate_slab_attrs(struct kmem_cache *s) |
5050 | { |
5051 | #ifdef CONFIG_MEMCG_KMEM |
5052 | int i; |
5053 | char *buffer = NULL; |
5054 | struct kmem_cache *root_cache; |
5055 | |
5056 | if (is_root_cache(s)) |
5057 | return; |
5058 | |
5059 | root_cache = s->memcg_params->root_cache; |
5060 | |
5061 | /* |
5062 | * This mean this cache had no attribute written. Therefore, no point |
5063 | * in copying default values around |
5064 | */ |
5065 | if (!root_cache->max_attr_size) |
5066 | return; |
5067 | |
5068 | for (i = 0; i < ARRAY_SIZE(slab_attrs); i++) { |
5069 | char mbuf[64]; |
5070 | char *buf; |
5071 | struct slab_attribute *attr = to_slab_attr(slab_attrs[i]); |
5072 | |
5073 | if (!attr || !attr->store || !attr->show) |
5074 | continue; |
5075 | |
5076 | /* |
5077 | * It is really bad that we have to allocate here, so we will |
5078 | * do it only as a fallback. If we actually allocate, though, |
5079 | * we can just use the allocated buffer until the end. |
5080 | * |
5081 | * Most of the slub attributes will tend to be very small in |
5082 | * size, but sysfs allows buffers up to a page, so they can |
5083 | * theoretically happen. |
5084 | */ |
5085 | if (buffer) |
5086 | buf = buffer; |
5087 | else if (root_cache->max_attr_size < ARRAY_SIZE(mbuf)) |
5088 | buf = mbuf; |
5089 | else { |
5090 | buffer = (char *) get_zeroed_page(GFP_KERNEL); |
5091 | if (WARN_ON(!buffer)) |
5092 | continue; |
5093 | buf = buffer; |
5094 | } |
5095 | |
5096 | attr->show(root_cache, buf); |
5097 | attr->store(s, buf, strlen(buf)); |
5098 | } |
5099 | |
5100 | if (buffer) |
5101 | free_page((unsigned long)buffer); |
5102 | #endif |
5103 | } |
5104 | |
5105 | static void kmem_cache_release(struct kobject *k) |
5106 | { |
5107 | slab_kmem_cache_release(to_slab(k)); |
5108 | } |
5109 | |
5110 | static const struct sysfs_ops slab_sysfs_ops = { |
5111 | .show = slab_attr_show, |
5112 | .store = slab_attr_store, |
5113 | }; |
5114 | |
5115 | static struct kobj_type slab_ktype = { |
5116 | .sysfs_ops = &slab_sysfs_ops, |
5117 | .release = kmem_cache_release, |
5118 | }; |
5119 | |
5120 | static int uevent_filter(struct kset *kset, struct kobject *kobj) |
5121 | { |
5122 | struct kobj_type *ktype = get_ktype(kobj); |
5123 | |
5124 | if (ktype == &slab_ktype) |
5125 | return 1; |
5126 | return 0; |
5127 | } |
5128 | |
5129 | static const struct kset_uevent_ops slab_uevent_ops = { |
5130 | .filter = uevent_filter, |
5131 | }; |
5132 | |
5133 | static struct kset *slab_kset; |
5134 | |
5135 | static inline struct kset *cache_kset(struct kmem_cache *s) |
5136 | { |
5137 | #ifdef CONFIG_MEMCG_KMEM |
5138 | if (!is_root_cache(s)) |
5139 | return s->memcg_params->root_cache->memcg_kset; |
5140 | #endif |
5141 | return slab_kset; |
5142 | } |
5143 | |
5144 | #define ID_STR_LENGTH 64 |
5145 | |
5146 | /* Create a unique string id for a slab cache: |
5147 | * |
5148 | * Format :[flags-]size |
5149 | */ |
5150 | static char *create_unique_id(struct kmem_cache *s) |
5151 | { |
5152 | char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); |
5153 | char *p = name; |
5154 | |
5155 | BUG_ON(!name); |
5156 | |
5157 | *p++ = ':'; |
5158 | /* |
5159 | * First flags affecting slabcache operations. We will only |
5160 | * get here for aliasable slabs so we do not need to support |
5161 | * too many flags. The flags here must cover all flags that |
5162 | * are matched during merging to guarantee that the id is |
5163 | * unique. |
5164 | */ |
5165 | if (s->flags & SLAB_CACHE_DMA) |
5166 | *p++ = 'd'; |
5167 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
5168 | *p++ = 'a'; |
5169 | if (s->flags & SLAB_DEBUG_FREE) |
5170 | *p++ = 'F'; |
5171 | if (!(s->flags & SLAB_NOTRACK)) |
5172 | *p++ = 't'; |
5173 | if (p != name + 1) |
5174 | *p++ = '-'; |
5175 | p += sprintf(p, "%07d", s->size); |
5176 | |
5177 | #ifdef CONFIG_MEMCG_KMEM |
5178 | if (!is_root_cache(s)) |
5179 | p += sprintf(p, "-%08d", |
5180 | memcg_cache_id(s->memcg_params->memcg)); |
5181 | #endif |
5182 | |
5183 | BUG_ON(p > name + ID_STR_LENGTH - 1); |
5184 | return name; |
5185 | } |
5186 | |
5187 | static int sysfs_slab_add(struct kmem_cache *s) |
5188 | { |
5189 | int err; |
5190 | const char *name; |
5191 | int unmergeable = slab_unmergeable(s); |
5192 | |
5193 | if (unmergeable) { |
5194 | /* |
5195 | * Slabcache can never be merged so we can use the name proper. |
5196 | * This is typically the case for debug situations. In that |
5197 | * case we can catch duplicate names easily. |
5198 | */ |
5199 | sysfs_remove_link(&slab_kset->kobj, s->name); |
5200 | name = s->name; |
5201 | } else { |
5202 | /* |
5203 | * Create a unique name for the slab as a target |
5204 | * for the symlinks. |
5205 | */ |
5206 | name = create_unique_id(s); |
5207 | } |
5208 | |
5209 | s->kobj.kset = cache_kset(s); |
5210 | err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name); |
5211 | if (err) |
5212 | goto out_put_kobj; |
5213 | |
5214 | err = sysfs_create_group(&s->kobj, &slab_attr_group); |
5215 | if (err) |
5216 | goto out_del_kobj; |
5217 | |
5218 | #ifdef CONFIG_MEMCG_KMEM |
5219 | if (is_root_cache(s)) { |
5220 | s->memcg_kset = kset_create_and_add("cgroup", NULL, &s->kobj); |
5221 | if (!s->memcg_kset) { |
5222 | err = -ENOMEM; |
5223 | goto out_del_kobj; |
5224 | } |
5225 | } |
5226 | #endif |
5227 | |
5228 | kobject_uevent(&s->kobj, KOBJ_ADD); |
5229 | if (!unmergeable) { |
5230 | /* Setup first alias */ |
5231 | sysfs_slab_alias(s, s->name); |
5232 | } |
5233 | out: |
5234 | if (!unmergeable) |
5235 | kfree(name); |
5236 | return err; |
5237 | out_del_kobj: |
5238 | kobject_del(&s->kobj); |
5239 | out_put_kobj: |
5240 | kobject_put(&s->kobj); |
5241 | goto out; |
5242 | } |
5243 | |
5244 | void sysfs_slab_remove(struct kmem_cache *s) |
5245 | { |
5246 | if (slab_state < FULL) |
5247 | /* |
5248 | * Sysfs has not been setup yet so no need to remove the |
5249 | * cache from sysfs. |
5250 | */ |
5251 | return; |
5252 | |
5253 | #ifdef CONFIG_MEMCG_KMEM |
5254 | kset_unregister(s->memcg_kset); |
5255 | #endif |
5256 | kobject_uevent(&s->kobj, KOBJ_REMOVE); |
5257 | kobject_del(&s->kobj); |
5258 | kobject_put(&s->kobj); |
5259 | } |
5260 | |
5261 | /* |
5262 | * Need to buffer aliases during bootup until sysfs becomes |
5263 | * available lest we lose that information. |
5264 | */ |
5265 | struct saved_alias { |
5266 | struct kmem_cache *s; |
5267 | const char *name; |
5268 | struct saved_alias *next; |
5269 | }; |
5270 | |
5271 | static struct saved_alias *alias_list; |
5272 | |
5273 | static int sysfs_slab_alias(struct kmem_cache *s, const char *name) |
5274 | { |
5275 | struct saved_alias *al; |
5276 | |
5277 | if (slab_state == FULL) { |
5278 | /* |
5279 | * If we have a leftover link then remove it. |
5280 | */ |
5281 | sysfs_remove_link(&slab_kset->kobj, name); |
5282 | return sysfs_create_link(&slab_kset->kobj, &s->kobj, name); |
5283 | } |
5284 | |
5285 | al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); |
5286 | if (!al) |
5287 | return -ENOMEM; |
5288 | |
5289 | al->s = s; |
5290 | al->name = name; |
5291 | al->next = alias_list; |
5292 | alias_list = al; |
5293 | return 0; |
5294 | } |
5295 | |
5296 | static int __init slab_sysfs_init(void) |
5297 | { |
5298 | struct kmem_cache *s; |
5299 | int err; |
5300 | |
5301 | mutex_lock(&slab_mutex); |
5302 | |
5303 | slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj); |
5304 | if (!slab_kset) { |
5305 | mutex_unlock(&slab_mutex); |
5306 | printk(KERN_ERR "Cannot register slab subsystem.\n"); |
5307 | return -ENOSYS; |
5308 | } |
5309 | |
5310 | slab_state = FULL; |
5311 | |
5312 | list_for_each_entry(s, &slab_caches, list) { |
5313 | err = sysfs_slab_add(s); |
5314 | if (err) |
5315 | printk(KERN_ERR "SLUB: Unable to add boot slab %s" |
5316 | " to sysfs\n", s->name); |
5317 | } |
5318 | |
5319 | while (alias_list) { |
5320 | struct saved_alias *al = alias_list; |
5321 | |
5322 | alias_list = alias_list->next; |
5323 | err = sysfs_slab_alias(al->s, al->name); |
5324 | if (err) |
5325 | printk(KERN_ERR "SLUB: Unable to add boot slab alias" |
5326 | " %s to sysfs\n", al->name); |
5327 | kfree(al); |
5328 | } |
5329 | |
5330 | mutex_unlock(&slab_mutex); |
5331 | resiliency_test(); |
5332 | return 0; |
5333 | } |
5334 | |
5335 | __initcall(slab_sysfs_init); |
5336 | #endif /* CONFIG_SYSFS */ |
5337 | |
5338 | /* |
5339 | * The /proc/slabinfo ABI |
5340 | */ |
5341 | #ifdef CONFIG_SLABINFO |
5342 | void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo) |
5343 | { |
5344 | unsigned long nr_slabs = 0; |
5345 | unsigned long nr_objs = 0; |
5346 | unsigned long nr_free = 0; |
5347 | int node; |
5348 | |
5349 | for_each_online_node(node) { |
5350 | struct kmem_cache_node *n = get_node(s, node); |
5351 | |
5352 | if (!n) |
5353 | continue; |
5354 | |
5355 | nr_slabs += node_nr_slabs(n); |
5356 | nr_objs += node_nr_objs(n); |
5357 | nr_free += count_partial(n, count_free); |
5358 | } |
5359 | |
5360 | sinfo->active_objs = nr_objs - nr_free; |
5361 | sinfo->num_objs = nr_objs; |
5362 | sinfo->active_slabs = nr_slabs; |
5363 | sinfo->num_slabs = nr_slabs; |
5364 | sinfo->objects_per_slab = oo_objects(s->oo); |
5365 | sinfo->cache_order = oo_order(s->oo); |
5366 | } |
5367 | |
5368 | void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s) |
5369 | { |
5370 | } |
5371 | |
5372 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
5373 | size_t count, loff_t *ppos) |
5374 | { |
5375 | return -EIO; |
5376 | } |
5377 | #endif /* CONFIG_SLABINFO */ |
5378 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9