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1 | /* |
2 | * linux/mm/slab.c |
3 | * Written by Mark Hemment, 1996/97. |
4 | * (markhe@nextd.demon.co.uk) |
5 | * |
6 | * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli |
7 | * |
8 | * Major cleanup, different bufctl logic, per-cpu arrays |
9 | * (c) 2000 Manfred Spraul |
10 | * |
11 | * Cleanup, make the head arrays unconditional, preparation for NUMA |
12 | * (c) 2002 Manfred Spraul |
13 | * |
14 | * An implementation of the Slab Allocator as described in outline in; |
15 | * UNIX Internals: The New Frontiers by Uresh Vahalia |
16 | * Pub: Prentice Hall ISBN 0-13-101908-2 |
17 | * or with a little more detail in; |
18 | * The Slab Allocator: An Object-Caching Kernel Memory Allocator |
19 | * Jeff Bonwick (Sun Microsystems). |
20 | * Presented at: USENIX Summer 1994 Technical Conference |
21 | * |
22 | * The memory is organized in caches, one cache for each object type. |
23 | * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) |
24 | * Each cache consists out of many slabs (they are small (usually one |
25 | * page long) and always contiguous), and each slab contains multiple |
26 | * initialized objects. |
27 | * |
28 | * This means, that your constructor is used only for newly allocated |
29 | * slabs and you must pass objects with the same initializations to |
30 | * kmem_cache_free. |
31 | * |
32 | * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM, |
33 | * normal). If you need a special memory type, then must create a new |
34 | * cache for that memory type. |
35 | * |
36 | * In order to reduce fragmentation, the slabs are sorted in 3 groups: |
37 | * full slabs with 0 free objects |
38 | * partial slabs |
39 | * empty slabs with no allocated objects |
40 | * |
41 | * If partial slabs exist, then new allocations come from these slabs, |
42 | * otherwise from empty slabs or new slabs are allocated. |
43 | * |
44 | * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache |
45 | * during kmem_cache_destroy(). The caller must prevent concurrent allocs. |
46 | * |
47 | * Each cache has a short per-cpu head array, most allocs |
48 | * and frees go into that array, and if that array overflows, then 1/2 |
49 | * of the entries in the array are given back into the global cache. |
50 | * The head array is strictly LIFO and should improve the cache hit rates. |
51 | * On SMP, it additionally reduces the spinlock operations. |
52 | * |
53 | * The c_cpuarray may not be read with enabled local interrupts - |
54 | * it's changed with a smp_call_function(). |
55 | * |
56 | * SMP synchronization: |
57 | * constructors and destructors are called without any locking. |
58 | * Several members in struct kmem_cache and struct slab never change, they |
59 | * are accessed without any locking. |
60 | * The per-cpu arrays are never accessed from the wrong cpu, no locking, |
61 | * and local interrupts are disabled so slab code is preempt-safe. |
62 | * The non-constant members are protected with a per-cache irq spinlock. |
63 | * |
64 | * Many thanks to Mark Hemment, who wrote another per-cpu slab patch |
65 | * in 2000 - many ideas in the current implementation are derived from |
66 | * his patch. |
67 | * |
68 | * Further notes from the original documentation: |
69 | * |
70 | * 11 April '97. Started multi-threading - markhe |
71 | * The global cache-chain is protected by the mutex 'slab_mutex'. |
72 | * The sem is only needed when accessing/extending the cache-chain, which |
73 | * can never happen inside an interrupt (kmem_cache_create(), |
74 | * kmem_cache_shrink() and kmem_cache_reap()). |
75 | * |
76 | * At present, each engine can be growing a cache. This should be blocked. |
77 | * |
78 | * 15 March 2005. NUMA slab allocator. |
79 | * Shai Fultheim <shai@scalex86.org>. |
80 | * Shobhit Dayal <shobhit@calsoftinc.com> |
81 | * Alok N Kataria <alokk@calsoftinc.com> |
82 | * Christoph Lameter <christoph@lameter.com> |
83 | * |
84 | * Modified the slab allocator to be node aware on NUMA systems. |
85 | * Each node has its own list of partial, free and full slabs. |
86 | * All object allocations for a node occur from node specific slab lists. |
87 | */ |
88 | |
89 | #include <linux/slab.h> |
90 | #include <linux/mm.h> |
91 | #include <linux/poison.h> |
92 | #include <linux/swap.h> |
93 | #include <linux/cache.h> |
94 | #include <linux/interrupt.h> |
95 | #include <linux/init.h> |
96 | #include <linux/compiler.h> |
97 | #include <linux/cpuset.h> |
98 | #include <linux/proc_fs.h> |
99 | #include <linux/seq_file.h> |
100 | #include <linux/notifier.h> |
101 | #include <linux/kallsyms.h> |
102 | #include <linux/cpu.h> |
103 | #include <linux/sysctl.h> |
104 | #include <linux/module.h> |
105 | #include <linux/rcupdate.h> |
106 | #include <linux/string.h> |
107 | #include <linux/uaccess.h> |
108 | #include <linux/nodemask.h> |
109 | #include <linux/kmemleak.h> |
110 | #include <linux/mempolicy.h> |
111 | #include <linux/mutex.h> |
112 | #include <linux/fault-inject.h> |
113 | #include <linux/rtmutex.h> |
114 | #include <linux/reciprocal_div.h> |
115 | #include <linux/debugobjects.h> |
116 | #include <linux/kmemcheck.h> |
117 | #include <linux/memory.h> |
118 | #include <linux/prefetch.h> |
119 | |
120 | #include <net/sock.h> |
121 | |
122 | #include <asm/cacheflush.h> |
123 | #include <asm/tlbflush.h> |
124 | #include <asm/page.h> |
125 | |
126 | #include <trace/events/kmem.h> |
127 | |
128 | #include "internal.h" |
129 | |
130 | #include "slab.h" |
131 | |
132 | /* |
133 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. |
134 | * 0 for faster, smaller code (especially in the critical paths). |
135 | * |
136 | * STATS - 1 to collect stats for /proc/slabinfo. |
137 | * 0 for faster, smaller code (especially in the critical paths). |
138 | * |
139 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) |
140 | */ |
141 | |
142 | #ifdef CONFIG_DEBUG_SLAB |
143 | #define DEBUG 1 |
144 | #define STATS 1 |
145 | #define FORCED_DEBUG 1 |
146 | #else |
147 | #define DEBUG 0 |
148 | #define STATS 0 |
149 | #define FORCED_DEBUG 0 |
150 | #endif |
151 | |
152 | /* Shouldn't this be in a header file somewhere? */ |
153 | #define BYTES_PER_WORD sizeof(void *) |
154 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) |
155 | |
156 | #ifndef ARCH_KMALLOC_FLAGS |
157 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN |
158 | #endif |
159 | |
160 | /* |
161 | * true if a page was allocated from pfmemalloc reserves for network-based |
162 | * swap |
163 | */ |
164 | static bool pfmemalloc_active __read_mostly; |
165 | |
166 | /* |
167 | * struct array_cache |
168 | * |
169 | * Purpose: |
170 | * - LIFO ordering, to hand out cache-warm objects from _alloc |
171 | * - reduce the number of linked list operations |
172 | * - reduce spinlock operations |
173 | * |
174 | * The limit is stored in the per-cpu structure to reduce the data cache |
175 | * footprint. |
176 | * |
177 | */ |
178 | struct array_cache { |
179 | unsigned int avail; |
180 | unsigned int limit; |
181 | unsigned int batchcount; |
182 | unsigned int touched; |
183 | spinlock_t lock; |
184 | void *entry[]; /* |
185 | * Must have this definition in here for the proper |
186 | * alignment of array_cache. Also simplifies accessing |
187 | * the entries. |
188 | * |
189 | * Entries should not be directly dereferenced as |
190 | * entries belonging to slabs marked pfmemalloc will |
191 | * have the lower bits set SLAB_OBJ_PFMEMALLOC |
192 | */ |
193 | }; |
194 | |
195 | #define SLAB_OBJ_PFMEMALLOC 1 |
196 | static inline bool is_obj_pfmemalloc(void *objp) |
197 | { |
198 | return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; |
199 | } |
200 | |
201 | static inline void set_obj_pfmemalloc(void **objp) |
202 | { |
203 | *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); |
204 | return; |
205 | } |
206 | |
207 | static inline void clear_obj_pfmemalloc(void **objp) |
208 | { |
209 | *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); |
210 | } |
211 | |
212 | /* |
213 | * bootstrap: The caches do not work without cpuarrays anymore, but the |
214 | * cpuarrays are allocated from the generic caches... |
215 | */ |
216 | #define BOOT_CPUCACHE_ENTRIES 1 |
217 | struct arraycache_init { |
218 | struct array_cache cache; |
219 | void *entries[BOOT_CPUCACHE_ENTRIES]; |
220 | }; |
221 | |
222 | /* |
223 | * Need this for bootstrapping a per node allocator. |
224 | */ |
225 | #define NUM_INIT_LISTS (3 * MAX_NUMNODES) |
226 | static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; |
227 | #define CACHE_CACHE 0 |
228 | #define SIZE_AC MAX_NUMNODES |
229 | #define SIZE_NODE (2 * MAX_NUMNODES) |
230 | |
231 | static int drain_freelist(struct kmem_cache *cache, |
232 | struct kmem_cache_node *n, int tofree); |
233 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, |
234 | int node); |
235 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); |
236 | static void cache_reap(struct work_struct *unused); |
237 | |
238 | static int slab_early_init = 1; |
239 | |
240 | #define INDEX_AC kmalloc_index(sizeof(struct arraycache_init)) |
241 | #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) |
242 | |
243 | static void kmem_cache_node_init(struct kmem_cache_node *parent) |
244 | { |
245 | INIT_LIST_HEAD(&parent->slabs_full); |
246 | INIT_LIST_HEAD(&parent->slabs_partial); |
247 | INIT_LIST_HEAD(&parent->slabs_free); |
248 | parent->shared = NULL; |
249 | parent->alien = NULL; |
250 | parent->colour_next = 0; |
251 | spin_lock_init(&parent->list_lock); |
252 | parent->free_objects = 0; |
253 | parent->free_touched = 0; |
254 | } |
255 | |
256 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ |
257 | do { \ |
258 | INIT_LIST_HEAD(listp); \ |
259 | list_splice(&(cachep->node[nodeid]->slab), listp); \ |
260 | } while (0) |
261 | |
262 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ |
263 | do { \ |
264 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ |
265 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ |
266 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ |
267 | } while (0) |
268 | |
269 | #define CFLGS_OFF_SLAB (0x80000000UL) |
270 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
271 | |
272 | #define BATCHREFILL_LIMIT 16 |
273 | /* |
274 | * Optimization question: fewer reaps means less probability for unnessary |
275 | * cpucache drain/refill cycles. |
276 | * |
277 | * OTOH the cpuarrays can contain lots of objects, |
278 | * which could lock up otherwise freeable slabs. |
279 | */ |
280 | #define REAPTIMEOUT_CPUC (2*HZ) |
281 | #define REAPTIMEOUT_LIST3 (4*HZ) |
282 | |
283 | #if STATS |
284 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
285 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
286 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
287 | #define STATS_INC_GROWN(x) ((x)->grown++) |
288 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) |
289 | #define STATS_SET_HIGH(x) \ |
290 | do { \ |
291 | if ((x)->num_active > (x)->high_mark) \ |
292 | (x)->high_mark = (x)->num_active; \ |
293 | } while (0) |
294 | #define STATS_INC_ERR(x) ((x)->errors++) |
295 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
296 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
297 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) |
298 | #define STATS_SET_FREEABLE(x, i) \ |
299 | do { \ |
300 | if ((x)->max_freeable < i) \ |
301 | (x)->max_freeable = i; \ |
302 | } while (0) |
303 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
304 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
305 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
306 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
307 | #else |
308 | #define STATS_INC_ACTIVE(x) do { } while (0) |
309 | #define STATS_DEC_ACTIVE(x) do { } while (0) |
310 | #define STATS_INC_ALLOCED(x) do { } while (0) |
311 | #define STATS_INC_GROWN(x) do { } while (0) |
312 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) |
313 | #define STATS_SET_HIGH(x) do { } while (0) |
314 | #define STATS_INC_ERR(x) do { } while (0) |
315 | #define STATS_INC_NODEALLOCS(x) do { } while (0) |
316 | #define STATS_INC_NODEFREES(x) do { } while (0) |
317 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) |
318 | #define STATS_SET_FREEABLE(x, i) do { } while (0) |
319 | #define STATS_INC_ALLOCHIT(x) do { } while (0) |
320 | #define STATS_INC_ALLOCMISS(x) do { } while (0) |
321 | #define STATS_INC_FREEHIT(x) do { } while (0) |
322 | #define STATS_INC_FREEMISS(x) do { } while (0) |
323 | #endif |
324 | |
325 | #if DEBUG |
326 | |
327 | /* |
328 | * memory layout of objects: |
329 | * 0 : objp |
330 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that |
331 | * the end of an object is aligned with the end of the real |
332 | * allocation. Catches writes behind the end of the allocation. |
333 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: |
334 | * redzone word. |
335 | * cachep->obj_offset: The real object. |
336 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
337 | * cachep->size - 1* BYTES_PER_WORD: last caller address |
338 | * [BYTES_PER_WORD long] |
339 | */ |
340 | static int obj_offset(struct kmem_cache *cachep) |
341 | { |
342 | return cachep->obj_offset; |
343 | } |
344 | |
345 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) |
346 | { |
347 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
348 | return (unsigned long long*) (objp + obj_offset(cachep) - |
349 | sizeof(unsigned long long)); |
350 | } |
351 | |
352 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) |
353 | { |
354 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
355 | if (cachep->flags & SLAB_STORE_USER) |
356 | return (unsigned long long *)(objp + cachep->size - |
357 | sizeof(unsigned long long) - |
358 | REDZONE_ALIGN); |
359 | return (unsigned long long *) (objp + cachep->size - |
360 | sizeof(unsigned long long)); |
361 | } |
362 | |
363 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) |
364 | { |
365 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
366 | return (void **)(objp + cachep->size - BYTES_PER_WORD); |
367 | } |
368 | |
369 | #else |
370 | |
371 | #define obj_offset(x) 0 |
372 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
373 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
374 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
375 | |
376 | #endif |
377 | |
378 | /* |
379 | * Do not go above this order unless 0 objects fit into the slab or |
380 | * overridden on the command line. |
381 | */ |
382 | #define SLAB_MAX_ORDER_HI 1 |
383 | #define SLAB_MAX_ORDER_LO 0 |
384 | static int slab_max_order = SLAB_MAX_ORDER_LO; |
385 | static bool slab_max_order_set __initdata; |
386 | |
387 | static inline struct kmem_cache *virt_to_cache(const void *obj) |
388 | { |
389 | struct page *page = virt_to_head_page(obj); |
390 | return page->slab_cache; |
391 | } |
392 | |
393 | static inline void *index_to_obj(struct kmem_cache *cache, struct page *page, |
394 | unsigned int idx) |
395 | { |
396 | return page->s_mem + cache->size * idx; |
397 | } |
398 | |
399 | /* |
400 | * We want to avoid an expensive divide : (offset / cache->size) |
401 | * Using the fact that size is a constant for a particular cache, |
402 | * we can replace (offset / cache->size) by |
403 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) |
404 | */ |
405 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, |
406 | const struct page *page, void *obj) |
407 | { |
408 | u32 offset = (obj - page->s_mem); |
409 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); |
410 | } |
411 | |
412 | static struct arraycache_init initarray_generic = |
413 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
414 | |
415 | /* internal cache of cache description objs */ |
416 | static struct kmem_cache kmem_cache_boot = { |
417 | .batchcount = 1, |
418 | .limit = BOOT_CPUCACHE_ENTRIES, |
419 | .shared = 1, |
420 | .size = sizeof(struct kmem_cache), |
421 | .name = "kmem_cache", |
422 | }; |
423 | |
424 | #define BAD_ALIEN_MAGIC 0x01020304ul |
425 | |
426 | #ifdef CONFIG_LOCKDEP |
427 | |
428 | /* |
429 | * Slab sometimes uses the kmalloc slabs to store the slab headers |
430 | * for other slabs "off slab". |
431 | * The locking for this is tricky in that it nests within the locks |
432 | * of all other slabs in a few places; to deal with this special |
433 | * locking we put on-slab caches into a separate lock-class. |
434 | * |
435 | * We set lock class for alien array caches which are up during init. |
436 | * The lock annotation will be lost if all cpus of a node goes down and |
437 | * then comes back up during hotplug |
438 | */ |
439 | static struct lock_class_key on_slab_l3_key; |
440 | static struct lock_class_key on_slab_alc_key; |
441 | |
442 | static struct lock_class_key debugobj_l3_key; |
443 | static struct lock_class_key debugobj_alc_key; |
444 | |
445 | static void slab_set_lock_classes(struct kmem_cache *cachep, |
446 | struct lock_class_key *l3_key, struct lock_class_key *alc_key, |
447 | int q) |
448 | { |
449 | struct array_cache **alc; |
450 | struct kmem_cache_node *n; |
451 | int r; |
452 | |
453 | n = cachep->node[q]; |
454 | if (!n) |
455 | return; |
456 | |
457 | lockdep_set_class(&n->list_lock, l3_key); |
458 | alc = n->alien; |
459 | /* |
460 | * FIXME: This check for BAD_ALIEN_MAGIC |
461 | * should go away when common slab code is taught to |
462 | * work even without alien caches. |
463 | * Currently, non NUMA code returns BAD_ALIEN_MAGIC |
464 | * for alloc_alien_cache, |
465 | */ |
466 | if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) |
467 | return; |
468 | for_each_node(r) { |
469 | if (alc[r]) |
470 | lockdep_set_class(&alc[r]->lock, alc_key); |
471 | } |
472 | } |
473 | |
474 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
475 | { |
476 | slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node); |
477 | } |
478 | |
479 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
480 | { |
481 | int node; |
482 | |
483 | for_each_online_node(node) |
484 | slab_set_debugobj_lock_classes_node(cachep, node); |
485 | } |
486 | |
487 | static void init_node_lock_keys(int q) |
488 | { |
489 | int i; |
490 | |
491 | if (slab_state < UP) |
492 | return; |
493 | |
494 | for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) { |
495 | struct kmem_cache_node *n; |
496 | struct kmem_cache *cache = kmalloc_caches[i]; |
497 | |
498 | if (!cache) |
499 | continue; |
500 | |
501 | n = cache->node[q]; |
502 | if (!n || OFF_SLAB(cache)) |
503 | continue; |
504 | |
505 | slab_set_lock_classes(cache, &on_slab_l3_key, |
506 | &on_slab_alc_key, q); |
507 | } |
508 | } |
509 | |
510 | static void on_slab_lock_classes_node(struct kmem_cache *cachep, int q) |
511 | { |
512 | if (!cachep->node[q]) |
513 | return; |
514 | |
515 | slab_set_lock_classes(cachep, &on_slab_l3_key, |
516 | &on_slab_alc_key, q); |
517 | } |
518 | |
519 | static inline void on_slab_lock_classes(struct kmem_cache *cachep) |
520 | { |
521 | int node; |
522 | |
523 | VM_BUG_ON(OFF_SLAB(cachep)); |
524 | for_each_node(node) |
525 | on_slab_lock_classes_node(cachep, node); |
526 | } |
527 | |
528 | static inline void init_lock_keys(void) |
529 | { |
530 | int node; |
531 | |
532 | for_each_node(node) |
533 | init_node_lock_keys(node); |
534 | } |
535 | #else |
536 | static void init_node_lock_keys(int q) |
537 | { |
538 | } |
539 | |
540 | static inline void init_lock_keys(void) |
541 | { |
542 | } |
543 | |
544 | static inline void on_slab_lock_classes(struct kmem_cache *cachep) |
545 | { |
546 | } |
547 | |
548 | static inline void on_slab_lock_classes_node(struct kmem_cache *cachep, int node) |
549 | { |
550 | } |
551 | |
552 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
553 | { |
554 | } |
555 | |
556 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
557 | { |
558 | } |
559 | #endif |
560 | |
561 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); |
562 | |
563 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) |
564 | { |
565 | return cachep->array[smp_processor_id()]; |
566 | } |
567 | |
568 | static size_t slab_mgmt_size(size_t nr_objs, size_t align) |
569 | { |
570 | return ALIGN(nr_objs * sizeof(unsigned int), align); |
571 | } |
572 | |
573 | /* |
574 | * Calculate the number of objects and left-over bytes for a given buffer size. |
575 | */ |
576 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, |
577 | size_t align, int flags, size_t *left_over, |
578 | unsigned int *num) |
579 | { |
580 | int nr_objs; |
581 | size_t mgmt_size; |
582 | size_t slab_size = PAGE_SIZE << gfporder; |
583 | |
584 | /* |
585 | * The slab management structure can be either off the slab or |
586 | * on it. For the latter case, the memory allocated for a |
587 | * slab is used for: |
588 | * |
589 | * - One unsigned int for each object |
590 | * - Padding to respect alignment of @align |
591 | * - @buffer_size bytes for each object |
592 | * |
593 | * If the slab management structure is off the slab, then the |
594 | * alignment will already be calculated into the size. Because |
595 | * the slabs are all pages aligned, the objects will be at the |
596 | * correct alignment when allocated. |
597 | */ |
598 | if (flags & CFLGS_OFF_SLAB) { |
599 | mgmt_size = 0; |
600 | nr_objs = slab_size / buffer_size; |
601 | |
602 | } else { |
603 | /* |
604 | * Ignore padding for the initial guess. The padding |
605 | * is at most @align-1 bytes, and @buffer_size is at |
606 | * least @align. In the worst case, this result will |
607 | * be one greater than the number of objects that fit |
608 | * into the memory allocation when taking the padding |
609 | * into account. |
610 | */ |
611 | nr_objs = (slab_size) / (buffer_size + sizeof(unsigned int)); |
612 | |
613 | /* |
614 | * This calculated number will be either the right |
615 | * amount, or one greater than what we want. |
616 | */ |
617 | if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size |
618 | > slab_size) |
619 | nr_objs--; |
620 | |
621 | mgmt_size = slab_mgmt_size(nr_objs, align); |
622 | } |
623 | *num = nr_objs; |
624 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; |
625 | } |
626 | |
627 | #if DEBUG |
628 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) |
629 | |
630 | static void __slab_error(const char *function, struct kmem_cache *cachep, |
631 | char *msg) |
632 | { |
633 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
634 | function, cachep->name, msg); |
635 | dump_stack(); |
636 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
637 | } |
638 | #endif |
639 | |
640 | /* |
641 | * By default on NUMA we use alien caches to stage the freeing of |
642 | * objects allocated from other nodes. This causes massive memory |
643 | * inefficiencies when using fake NUMA setup to split memory into a |
644 | * large number of small nodes, so it can be disabled on the command |
645 | * line |
646 | */ |
647 | |
648 | static int use_alien_caches __read_mostly = 1; |
649 | static int __init noaliencache_setup(char *s) |
650 | { |
651 | use_alien_caches = 0; |
652 | return 1; |
653 | } |
654 | __setup("noaliencache", noaliencache_setup); |
655 | |
656 | static int __init slab_max_order_setup(char *str) |
657 | { |
658 | get_option(&str, &slab_max_order); |
659 | slab_max_order = slab_max_order < 0 ? 0 : |
660 | min(slab_max_order, MAX_ORDER - 1); |
661 | slab_max_order_set = true; |
662 | |
663 | return 1; |
664 | } |
665 | __setup("slab_max_order=", slab_max_order_setup); |
666 | |
667 | #ifdef CONFIG_NUMA |
668 | /* |
669 | * Special reaping functions for NUMA systems called from cache_reap(). |
670 | * These take care of doing round robin flushing of alien caches (containing |
671 | * objects freed on different nodes from which they were allocated) and the |
672 | * flushing of remote pcps by calling drain_node_pages. |
673 | */ |
674 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); |
675 | |
676 | static void init_reap_node(int cpu) |
677 | { |
678 | int node; |
679 | |
680 | node = next_node(cpu_to_mem(cpu), node_online_map); |
681 | if (node == MAX_NUMNODES) |
682 | node = first_node(node_online_map); |
683 | |
684 | per_cpu(slab_reap_node, cpu) = node; |
685 | } |
686 | |
687 | static void next_reap_node(void) |
688 | { |
689 | int node = __this_cpu_read(slab_reap_node); |
690 | |
691 | node = next_node(node, node_online_map); |
692 | if (unlikely(node >= MAX_NUMNODES)) |
693 | node = first_node(node_online_map); |
694 | __this_cpu_write(slab_reap_node, node); |
695 | } |
696 | |
697 | #else |
698 | #define init_reap_node(cpu) do { } while (0) |
699 | #define next_reap_node(void) do { } while (0) |
700 | #endif |
701 | |
702 | /* |
703 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
704 | * via the workqueue/eventd. |
705 | * Add the CPU number into the expiration time to minimize the possibility of |
706 | * the CPUs getting into lockstep and contending for the global cache chain |
707 | * lock. |
708 | */ |
709 | static void start_cpu_timer(int cpu) |
710 | { |
711 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); |
712 | |
713 | /* |
714 | * When this gets called from do_initcalls via cpucache_init(), |
715 | * init_workqueues() has already run, so keventd will be setup |
716 | * at that time. |
717 | */ |
718 | if (keventd_up() && reap_work->work.func == NULL) { |
719 | init_reap_node(cpu); |
720 | INIT_DEFERRABLE_WORK(reap_work, cache_reap); |
721 | schedule_delayed_work_on(cpu, reap_work, |
722 | __round_jiffies_relative(HZ, cpu)); |
723 | } |
724 | } |
725 | |
726 | static struct array_cache *alloc_arraycache(int node, int entries, |
727 | int batchcount, gfp_t gfp) |
728 | { |
729 | int memsize = sizeof(void *) * entries + sizeof(struct array_cache); |
730 | struct array_cache *nc = NULL; |
731 | |
732 | nc = kmalloc_node(memsize, gfp, node); |
733 | /* |
734 | * The array_cache structures contain pointers to free object. |
735 | * However, when such objects are allocated or transferred to another |
736 | * cache the pointers are not cleared and they could be counted as |
737 | * valid references during a kmemleak scan. Therefore, kmemleak must |
738 | * not scan such objects. |
739 | */ |
740 | kmemleak_no_scan(nc); |
741 | if (nc) { |
742 | nc->avail = 0; |
743 | nc->limit = entries; |
744 | nc->batchcount = batchcount; |
745 | nc->touched = 0; |
746 | spin_lock_init(&nc->lock); |
747 | } |
748 | return nc; |
749 | } |
750 | |
751 | static inline bool is_slab_pfmemalloc(struct page *page) |
752 | { |
753 | return PageSlabPfmemalloc(page); |
754 | } |
755 | |
756 | /* Clears pfmemalloc_active if no slabs have pfmalloc set */ |
757 | static void recheck_pfmemalloc_active(struct kmem_cache *cachep, |
758 | struct array_cache *ac) |
759 | { |
760 | struct kmem_cache_node *n = cachep->node[numa_mem_id()]; |
761 | struct page *page; |
762 | unsigned long flags; |
763 | |
764 | if (!pfmemalloc_active) |
765 | return; |
766 | |
767 | spin_lock_irqsave(&n->list_lock, flags); |
768 | list_for_each_entry(page, &n->slabs_full, lru) |
769 | if (is_slab_pfmemalloc(page)) |
770 | goto out; |
771 | |
772 | list_for_each_entry(page, &n->slabs_partial, lru) |
773 | if (is_slab_pfmemalloc(page)) |
774 | goto out; |
775 | |
776 | list_for_each_entry(page, &n->slabs_free, lru) |
777 | if (is_slab_pfmemalloc(page)) |
778 | goto out; |
779 | |
780 | pfmemalloc_active = false; |
781 | out: |
782 | spin_unlock_irqrestore(&n->list_lock, flags); |
783 | } |
784 | |
785 | static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, |
786 | gfp_t flags, bool force_refill) |
787 | { |
788 | int i; |
789 | void *objp = ac->entry[--ac->avail]; |
790 | |
791 | /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ |
792 | if (unlikely(is_obj_pfmemalloc(objp))) { |
793 | struct kmem_cache_node *n; |
794 | |
795 | if (gfp_pfmemalloc_allowed(flags)) { |
796 | clear_obj_pfmemalloc(&objp); |
797 | return objp; |
798 | } |
799 | |
800 | /* The caller cannot use PFMEMALLOC objects, find another one */ |
801 | for (i = 0; i < ac->avail; i++) { |
802 | /* If a !PFMEMALLOC object is found, swap them */ |
803 | if (!is_obj_pfmemalloc(ac->entry[i])) { |
804 | objp = ac->entry[i]; |
805 | ac->entry[i] = ac->entry[ac->avail]; |
806 | ac->entry[ac->avail] = objp; |
807 | return objp; |
808 | } |
809 | } |
810 | |
811 | /* |
812 | * If there are empty slabs on the slabs_free list and we are |
813 | * being forced to refill the cache, mark this one !pfmemalloc. |
814 | */ |
815 | n = cachep->node[numa_mem_id()]; |
816 | if (!list_empty(&n->slabs_free) && force_refill) { |
817 | struct page *page = virt_to_head_page(objp); |
818 | ClearPageSlabPfmemalloc(page); |
819 | clear_obj_pfmemalloc(&objp); |
820 | recheck_pfmemalloc_active(cachep, ac); |
821 | return objp; |
822 | } |
823 | |
824 | /* No !PFMEMALLOC objects available */ |
825 | ac->avail++; |
826 | objp = NULL; |
827 | } |
828 | |
829 | return objp; |
830 | } |
831 | |
832 | static inline void *ac_get_obj(struct kmem_cache *cachep, |
833 | struct array_cache *ac, gfp_t flags, bool force_refill) |
834 | { |
835 | void *objp; |
836 | |
837 | if (unlikely(sk_memalloc_socks())) |
838 | objp = __ac_get_obj(cachep, ac, flags, force_refill); |
839 | else |
840 | objp = ac->entry[--ac->avail]; |
841 | |
842 | return objp; |
843 | } |
844 | |
845 | static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
846 | void *objp) |
847 | { |
848 | if (unlikely(pfmemalloc_active)) { |
849 | /* Some pfmemalloc slabs exist, check if this is one */ |
850 | struct page *page = virt_to_head_page(objp); |
851 | if (PageSlabPfmemalloc(page)) |
852 | set_obj_pfmemalloc(&objp); |
853 | } |
854 | |
855 | return objp; |
856 | } |
857 | |
858 | static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
859 | void *objp) |
860 | { |
861 | if (unlikely(sk_memalloc_socks())) |
862 | objp = __ac_put_obj(cachep, ac, objp); |
863 | |
864 | ac->entry[ac->avail++] = objp; |
865 | } |
866 | |
867 | /* |
868 | * Transfer objects in one arraycache to another. |
869 | * Locking must be handled by the caller. |
870 | * |
871 | * Return the number of entries transferred. |
872 | */ |
873 | static int transfer_objects(struct array_cache *to, |
874 | struct array_cache *from, unsigned int max) |
875 | { |
876 | /* Figure out how many entries to transfer */ |
877 | int nr = min3(from->avail, max, to->limit - to->avail); |
878 | |
879 | if (!nr) |
880 | return 0; |
881 | |
882 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, |
883 | sizeof(void *) *nr); |
884 | |
885 | from->avail -= nr; |
886 | to->avail += nr; |
887 | return nr; |
888 | } |
889 | |
890 | #ifndef CONFIG_NUMA |
891 | |
892 | #define drain_alien_cache(cachep, alien) do { } while (0) |
893 | #define reap_alien(cachep, n) do { } while (0) |
894 | |
895 | static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
896 | { |
897 | return (struct array_cache **)BAD_ALIEN_MAGIC; |
898 | } |
899 | |
900 | static inline void free_alien_cache(struct array_cache **ac_ptr) |
901 | { |
902 | } |
903 | |
904 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
905 | { |
906 | return 0; |
907 | } |
908 | |
909 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, |
910 | gfp_t flags) |
911 | { |
912 | return NULL; |
913 | } |
914 | |
915 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, |
916 | gfp_t flags, int nodeid) |
917 | { |
918 | return NULL; |
919 | } |
920 | |
921 | #else /* CONFIG_NUMA */ |
922 | |
923 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); |
924 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); |
925 | |
926 | static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
927 | { |
928 | struct array_cache **ac_ptr; |
929 | int memsize = sizeof(void *) * nr_node_ids; |
930 | int i; |
931 | |
932 | if (limit > 1) |
933 | limit = 12; |
934 | ac_ptr = kzalloc_node(memsize, gfp, node); |
935 | if (ac_ptr) { |
936 | for_each_node(i) { |
937 | if (i == node || !node_online(i)) |
938 | continue; |
939 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); |
940 | if (!ac_ptr[i]) { |
941 | for (i--; i >= 0; i--) |
942 | kfree(ac_ptr[i]); |
943 | kfree(ac_ptr); |
944 | return NULL; |
945 | } |
946 | } |
947 | } |
948 | return ac_ptr; |
949 | } |
950 | |
951 | static void free_alien_cache(struct array_cache **ac_ptr) |
952 | { |
953 | int i; |
954 | |
955 | if (!ac_ptr) |
956 | return; |
957 | for_each_node(i) |
958 | kfree(ac_ptr[i]); |
959 | kfree(ac_ptr); |
960 | } |
961 | |
962 | static void __drain_alien_cache(struct kmem_cache *cachep, |
963 | struct array_cache *ac, int node) |
964 | { |
965 | struct kmem_cache_node *n = cachep->node[node]; |
966 | |
967 | if (ac->avail) { |
968 | spin_lock(&n->list_lock); |
969 | /* |
970 | * Stuff objects into the remote nodes shared array first. |
971 | * That way we could avoid the overhead of putting the objects |
972 | * into the free lists and getting them back later. |
973 | */ |
974 | if (n->shared) |
975 | transfer_objects(n->shared, ac, ac->limit); |
976 | |
977 | free_block(cachep, ac->entry, ac->avail, node); |
978 | ac->avail = 0; |
979 | spin_unlock(&n->list_lock); |
980 | } |
981 | } |
982 | |
983 | /* |
984 | * Called from cache_reap() to regularly drain alien caches round robin. |
985 | */ |
986 | static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) |
987 | { |
988 | int node = __this_cpu_read(slab_reap_node); |
989 | |
990 | if (n->alien) { |
991 | struct array_cache *ac = n->alien[node]; |
992 | |
993 | if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { |
994 | __drain_alien_cache(cachep, ac, node); |
995 | spin_unlock_irq(&ac->lock); |
996 | } |
997 | } |
998 | } |
999 | |
1000 | static void drain_alien_cache(struct kmem_cache *cachep, |
1001 | struct array_cache **alien) |
1002 | { |
1003 | int i = 0; |
1004 | struct array_cache *ac; |
1005 | unsigned long flags; |
1006 | |
1007 | for_each_online_node(i) { |
1008 | ac = alien[i]; |
1009 | if (ac) { |
1010 | spin_lock_irqsave(&ac->lock, flags); |
1011 | __drain_alien_cache(cachep, ac, i); |
1012 | spin_unlock_irqrestore(&ac->lock, flags); |
1013 | } |
1014 | } |
1015 | } |
1016 | |
1017 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
1018 | { |
1019 | int nodeid = page_to_nid(virt_to_page(objp)); |
1020 | struct kmem_cache_node *n; |
1021 | struct array_cache *alien = NULL; |
1022 | int node; |
1023 | |
1024 | node = numa_mem_id(); |
1025 | |
1026 | /* |
1027 | * Make sure we are not freeing a object from another node to the array |
1028 | * cache on this cpu. |
1029 | */ |
1030 | if (likely(nodeid == node)) |
1031 | return 0; |
1032 | |
1033 | n = cachep->node[node]; |
1034 | STATS_INC_NODEFREES(cachep); |
1035 | if (n->alien && n->alien[nodeid]) { |
1036 | alien = n->alien[nodeid]; |
1037 | spin_lock(&alien->lock); |
1038 | if (unlikely(alien->avail == alien->limit)) { |
1039 | STATS_INC_ACOVERFLOW(cachep); |
1040 | __drain_alien_cache(cachep, alien, nodeid); |
1041 | } |
1042 | ac_put_obj(cachep, alien, objp); |
1043 | spin_unlock(&alien->lock); |
1044 | } else { |
1045 | spin_lock(&(cachep->node[nodeid])->list_lock); |
1046 | free_block(cachep, &objp, 1, nodeid); |
1047 | spin_unlock(&(cachep->node[nodeid])->list_lock); |
1048 | } |
1049 | return 1; |
1050 | } |
1051 | #endif |
1052 | |
1053 | /* |
1054 | * Allocates and initializes node for a node on each slab cache, used for |
1055 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node |
1056 | * will be allocated off-node since memory is not yet online for the new node. |
1057 | * When hotplugging memory or a cpu, existing node are not replaced if |
1058 | * already in use. |
1059 | * |
1060 | * Must hold slab_mutex. |
1061 | */ |
1062 | static int init_cache_node_node(int node) |
1063 | { |
1064 | struct kmem_cache *cachep; |
1065 | struct kmem_cache_node *n; |
1066 | const int memsize = sizeof(struct kmem_cache_node); |
1067 | |
1068 | list_for_each_entry(cachep, &slab_caches, list) { |
1069 | /* |
1070 | * Set up the size64 kmemlist for cpu before we can |
1071 | * begin anything. Make sure some other cpu on this |
1072 | * node has not already allocated this |
1073 | */ |
1074 | if (!cachep->node[node]) { |
1075 | n = kmalloc_node(memsize, GFP_KERNEL, node); |
1076 | if (!n) |
1077 | return -ENOMEM; |
1078 | kmem_cache_node_init(n); |
1079 | n->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
1080 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1081 | |
1082 | /* |
1083 | * The l3s don't come and go as CPUs come and |
1084 | * go. slab_mutex is sufficient |
1085 | * protection here. |
1086 | */ |
1087 | cachep->node[node] = n; |
1088 | } |
1089 | |
1090 | spin_lock_irq(&cachep->node[node]->list_lock); |
1091 | cachep->node[node]->free_limit = |
1092 | (1 + nr_cpus_node(node)) * |
1093 | cachep->batchcount + cachep->num; |
1094 | spin_unlock_irq(&cachep->node[node]->list_lock); |
1095 | } |
1096 | return 0; |
1097 | } |
1098 | |
1099 | static inline int slabs_tofree(struct kmem_cache *cachep, |
1100 | struct kmem_cache_node *n) |
1101 | { |
1102 | return (n->free_objects + cachep->num - 1) / cachep->num; |
1103 | } |
1104 | |
1105 | static void cpuup_canceled(long cpu) |
1106 | { |
1107 | struct kmem_cache *cachep; |
1108 | struct kmem_cache_node *n = NULL; |
1109 | int node = cpu_to_mem(cpu); |
1110 | const struct cpumask *mask = cpumask_of_node(node); |
1111 | |
1112 | list_for_each_entry(cachep, &slab_caches, list) { |
1113 | struct array_cache *nc; |
1114 | struct array_cache *shared; |
1115 | struct array_cache **alien; |
1116 | |
1117 | /* cpu is dead; no one can alloc from it. */ |
1118 | nc = cachep->array[cpu]; |
1119 | cachep->array[cpu] = NULL; |
1120 | n = cachep->node[node]; |
1121 | |
1122 | if (!n) |
1123 | goto free_array_cache; |
1124 | |
1125 | spin_lock_irq(&n->list_lock); |
1126 | |
1127 | /* Free limit for this kmem_cache_node */ |
1128 | n->free_limit -= cachep->batchcount; |
1129 | if (nc) |
1130 | free_block(cachep, nc->entry, nc->avail, node); |
1131 | |
1132 | if (!cpumask_empty(mask)) { |
1133 | spin_unlock_irq(&n->list_lock); |
1134 | goto free_array_cache; |
1135 | } |
1136 | |
1137 | shared = n->shared; |
1138 | if (shared) { |
1139 | free_block(cachep, shared->entry, |
1140 | shared->avail, node); |
1141 | n->shared = NULL; |
1142 | } |
1143 | |
1144 | alien = n->alien; |
1145 | n->alien = NULL; |
1146 | |
1147 | spin_unlock_irq(&n->list_lock); |
1148 | |
1149 | kfree(shared); |
1150 | if (alien) { |
1151 | drain_alien_cache(cachep, alien); |
1152 | free_alien_cache(alien); |
1153 | } |
1154 | free_array_cache: |
1155 | kfree(nc); |
1156 | } |
1157 | /* |
1158 | * In the previous loop, all the objects were freed to |
1159 | * the respective cache's slabs, now we can go ahead and |
1160 | * shrink each nodelist to its limit. |
1161 | */ |
1162 | list_for_each_entry(cachep, &slab_caches, list) { |
1163 | n = cachep->node[node]; |
1164 | if (!n) |
1165 | continue; |
1166 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
1167 | } |
1168 | } |
1169 | |
1170 | static int cpuup_prepare(long cpu) |
1171 | { |
1172 | struct kmem_cache *cachep; |
1173 | struct kmem_cache_node *n = NULL; |
1174 | int node = cpu_to_mem(cpu); |
1175 | int err; |
1176 | |
1177 | /* |
1178 | * We need to do this right in the beginning since |
1179 | * alloc_arraycache's are going to use this list. |
1180 | * kmalloc_node allows us to add the slab to the right |
1181 | * kmem_cache_node and not this cpu's kmem_cache_node |
1182 | */ |
1183 | err = init_cache_node_node(node); |
1184 | if (err < 0) |
1185 | goto bad; |
1186 | |
1187 | /* |
1188 | * Now we can go ahead with allocating the shared arrays and |
1189 | * array caches |
1190 | */ |
1191 | list_for_each_entry(cachep, &slab_caches, list) { |
1192 | struct array_cache *nc; |
1193 | struct array_cache *shared = NULL; |
1194 | struct array_cache **alien = NULL; |
1195 | |
1196 | nc = alloc_arraycache(node, cachep->limit, |
1197 | cachep->batchcount, GFP_KERNEL); |
1198 | if (!nc) |
1199 | goto bad; |
1200 | if (cachep->shared) { |
1201 | shared = alloc_arraycache(node, |
1202 | cachep->shared * cachep->batchcount, |
1203 | 0xbaadf00d, GFP_KERNEL); |
1204 | if (!shared) { |
1205 | kfree(nc); |
1206 | goto bad; |
1207 | } |
1208 | } |
1209 | if (use_alien_caches) { |
1210 | alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); |
1211 | if (!alien) { |
1212 | kfree(shared); |
1213 | kfree(nc); |
1214 | goto bad; |
1215 | } |
1216 | } |
1217 | cachep->array[cpu] = nc; |
1218 | n = cachep->node[node]; |
1219 | BUG_ON(!n); |
1220 | |
1221 | spin_lock_irq(&n->list_lock); |
1222 | if (!n->shared) { |
1223 | /* |
1224 | * We are serialised from CPU_DEAD or |
1225 | * CPU_UP_CANCELLED by the cpucontrol lock |
1226 | */ |
1227 | n->shared = shared; |
1228 | shared = NULL; |
1229 | } |
1230 | #ifdef CONFIG_NUMA |
1231 | if (!n->alien) { |
1232 | n->alien = alien; |
1233 | alien = NULL; |
1234 | } |
1235 | #endif |
1236 | spin_unlock_irq(&n->list_lock); |
1237 | kfree(shared); |
1238 | free_alien_cache(alien); |
1239 | if (cachep->flags & SLAB_DEBUG_OBJECTS) |
1240 | slab_set_debugobj_lock_classes_node(cachep, node); |
1241 | else if (!OFF_SLAB(cachep) && |
1242 | !(cachep->flags & SLAB_DESTROY_BY_RCU)) |
1243 | on_slab_lock_classes_node(cachep, node); |
1244 | } |
1245 | init_node_lock_keys(node); |
1246 | |
1247 | return 0; |
1248 | bad: |
1249 | cpuup_canceled(cpu); |
1250 | return -ENOMEM; |
1251 | } |
1252 | |
1253 | static int cpuup_callback(struct notifier_block *nfb, |
1254 | unsigned long action, void *hcpu) |
1255 | { |
1256 | long cpu = (long)hcpu; |
1257 | int err = 0; |
1258 | |
1259 | switch (action) { |
1260 | case CPU_UP_PREPARE: |
1261 | case CPU_UP_PREPARE_FROZEN: |
1262 | mutex_lock(&slab_mutex); |
1263 | err = cpuup_prepare(cpu); |
1264 | mutex_unlock(&slab_mutex); |
1265 | break; |
1266 | case CPU_ONLINE: |
1267 | case CPU_ONLINE_FROZEN: |
1268 | start_cpu_timer(cpu); |
1269 | break; |
1270 | #ifdef CONFIG_HOTPLUG_CPU |
1271 | case CPU_DOWN_PREPARE: |
1272 | case CPU_DOWN_PREPARE_FROZEN: |
1273 | /* |
1274 | * Shutdown cache reaper. Note that the slab_mutex is |
1275 | * held so that if cache_reap() is invoked it cannot do |
1276 | * anything expensive but will only modify reap_work |
1277 | * and reschedule the timer. |
1278 | */ |
1279 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); |
1280 | /* Now the cache_reaper is guaranteed to be not running. */ |
1281 | per_cpu(slab_reap_work, cpu).work.func = NULL; |
1282 | break; |
1283 | case CPU_DOWN_FAILED: |
1284 | case CPU_DOWN_FAILED_FROZEN: |
1285 | start_cpu_timer(cpu); |
1286 | break; |
1287 | case CPU_DEAD: |
1288 | case CPU_DEAD_FROZEN: |
1289 | /* |
1290 | * Even if all the cpus of a node are down, we don't free the |
1291 | * kmem_cache_node of any cache. This to avoid a race between |
1292 | * cpu_down, and a kmalloc allocation from another cpu for |
1293 | * memory from the node of the cpu going down. The node |
1294 | * structure is usually allocated from kmem_cache_create() and |
1295 | * gets destroyed at kmem_cache_destroy(). |
1296 | */ |
1297 | /* fall through */ |
1298 | #endif |
1299 | case CPU_UP_CANCELED: |
1300 | case CPU_UP_CANCELED_FROZEN: |
1301 | mutex_lock(&slab_mutex); |
1302 | cpuup_canceled(cpu); |
1303 | mutex_unlock(&slab_mutex); |
1304 | break; |
1305 | } |
1306 | return notifier_from_errno(err); |
1307 | } |
1308 | |
1309 | static struct notifier_block cpucache_notifier = { |
1310 | &cpuup_callback, NULL, 0 |
1311 | }; |
1312 | |
1313 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
1314 | /* |
1315 | * Drains freelist for a node on each slab cache, used for memory hot-remove. |
1316 | * Returns -EBUSY if all objects cannot be drained so that the node is not |
1317 | * removed. |
1318 | * |
1319 | * Must hold slab_mutex. |
1320 | */ |
1321 | static int __meminit drain_cache_node_node(int node) |
1322 | { |
1323 | struct kmem_cache *cachep; |
1324 | int ret = 0; |
1325 | |
1326 | list_for_each_entry(cachep, &slab_caches, list) { |
1327 | struct kmem_cache_node *n; |
1328 | |
1329 | n = cachep->node[node]; |
1330 | if (!n) |
1331 | continue; |
1332 | |
1333 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
1334 | |
1335 | if (!list_empty(&n->slabs_full) || |
1336 | !list_empty(&n->slabs_partial)) { |
1337 | ret = -EBUSY; |
1338 | break; |
1339 | } |
1340 | } |
1341 | return ret; |
1342 | } |
1343 | |
1344 | static int __meminit slab_memory_callback(struct notifier_block *self, |
1345 | unsigned long action, void *arg) |
1346 | { |
1347 | struct memory_notify *mnb = arg; |
1348 | int ret = 0; |
1349 | int nid; |
1350 | |
1351 | nid = mnb->status_change_nid; |
1352 | if (nid < 0) |
1353 | goto out; |
1354 | |
1355 | switch (action) { |
1356 | case MEM_GOING_ONLINE: |
1357 | mutex_lock(&slab_mutex); |
1358 | ret = init_cache_node_node(nid); |
1359 | mutex_unlock(&slab_mutex); |
1360 | break; |
1361 | case MEM_GOING_OFFLINE: |
1362 | mutex_lock(&slab_mutex); |
1363 | ret = drain_cache_node_node(nid); |
1364 | mutex_unlock(&slab_mutex); |
1365 | break; |
1366 | case MEM_ONLINE: |
1367 | case MEM_OFFLINE: |
1368 | case MEM_CANCEL_ONLINE: |
1369 | case MEM_CANCEL_OFFLINE: |
1370 | break; |
1371 | } |
1372 | out: |
1373 | return notifier_from_errno(ret); |
1374 | } |
1375 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ |
1376 | |
1377 | /* |
1378 | * swap the static kmem_cache_node with kmalloced memory |
1379 | */ |
1380 | static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, |
1381 | int nodeid) |
1382 | { |
1383 | struct kmem_cache_node *ptr; |
1384 | |
1385 | ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); |
1386 | BUG_ON(!ptr); |
1387 | |
1388 | memcpy(ptr, list, sizeof(struct kmem_cache_node)); |
1389 | /* |
1390 | * Do not assume that spinlocks can be initialized via memcpy: |
1391 | */ |
1392 | spin_lock_init(&ptr->list_lock); |
1393 | |
1394 | MAKE_ALL_LISTS(cachep, ptr, nodeid); |
1395 | cachep->node[nodeid] = ptr; |
1396 | } |
1397 | |
1398 | /* |
1399 | * For setting up all the kmem_cache_node for cache whose buffer_size is same as |
1400 | * size of kmem_cache_node. |
1401 | */ |
1402 | static void __init set_up_node(struct kmem_cache *cachep, int index) |
1403 | { |
1404 | int node; |
1405 | |
1406 | for_each_online_node(node) { |
1407 | cachep->node[node] = &init_kmem_cache_node[index + node]; |
1408 | cachep->node[node]->next_reap = jiffies + |
1409 | REAPTIMEOUT_LIST3 + |
1410 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1411 | } |
1412 | } |
1413 | |
1414 | /* |
1415 | * The memory after the last cpu cache pointer is used for the |
1416 | * the node pointer. |
1417 | */ |
1418 | static void setup_node_pointer(struct kmem_cache *cachep) |
1419 | { |
1420 | cachep->node = (struct kmem_cache_node **)&cachep->array[nr_cpu_ids]; |
1421 | } |
1422 | |
1423 | /* |
1424 | * Initialisation. Called after the page allocator have been initialised and |
1425 | * before smp_init(). |
1426 | */ |
1427 | void __init kmem_cache_init(void) |
1428 | { |
1429 | int i; |
1430 | |
1431 | BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) < |
1432 | sizeof(struct rcu_head)); |
1433 | kmem_cache = &kmem_cache_boot; |
1434 | setup_node_pointer(kmem_cache); |
1435 | |
1436 | if (num_possible_nodes() == 1) |
1437 | use_alien_caches = 0; |
1438 | |
1439 | for (i = 0; i < NUM_INIT_LISTS; i++) |
1440 | kmem_cache_node_init(&init_kmem_cache_node[i]); |
1441 | |
1442 | set_up_node(kmem_cache, CACHE_CACHE); |
1443 | |
1444 | /* |
1445 | * Fragmentation resistance on low memory - only use bigger |
1446 | * page orders on machines with more than 32MB of memory if |
1447 | * not overridden on the command line. |
1448 | */ |
1449 | if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) |
1450 | slab_max_order = SLAB_MAX_ORDER_HI; |
1451 | |
1452 | /* Bootstrap is tricky, because several objects are allocated |
1453 | * from caches that do not exist yet: |
1454 | * 1) initialize the kmem_cache cache: it contains the struct |
1455 | * kmem_cache structures of all caches, except kmem_cache itself: |
1456 | * kmem_cache is statically allocated. |
1457 | * Initially an __init data area is used for the head array and the |
1458 | * kmem_cache_node structures, it's replaced with a kmalloc allocated |
1459 | * array at the end of the bootstrap. |
1460 | * 2) Create the first kmalloc cache. |
1461 | * The struct kmem_cache for the new cache is allocated normally. |
1462 | * An __init data area is used for the head array. |
1463 | * 3) Create the remaining kmalloc caches, with minimally sized |
1464 | * head arrays. |
1465 | * 4) Replace the __init data head arrays for kmem_cache and the first |
1466 | * kmalloc cache with kmalloc allocated arrays. |
1467 | * 5) Replace the __init data for kmem_cache_node for kmem_cache and |
1468 | * the other cache's with kmalloc allocated memory. |
1469 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. |
1470 | */ |
1471 | |
1472 | /* 1) create the kmem_cache */ |
1473 | |
1474 | /* |
1475 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids |
1476 | */ |
1477 | create_boot_cache(kmem_cache, "kmem_cache", |
1478 | offsetof(struct kmem_cache, array[nr_cpu_ids]) + |
1479 | nr_node_ids * sizeof(struct kmem_cache_node *), |
1480 | SLAB_HWCACHE_ALIGN); |
1481 | list_add(&kmem_cache->list, &slab_caches); |
1482 | |
1483 | /* 2+3) create the kmalloc caches */ |
1484 | |
1485 | /* |
1486 | * Initialize the caches that provide memory for the array cache and the |
1487 | * kmem_cache_node structures first. Without this, further allocations will |
1488 | * bug. |
1489 | */ |
1490 | |
1491 | kmalloc_caches[INDEX_AC] = create_kmalloc_cache("kmalloc-ac", |
1492 | kmalloc_size(INDEX_AC), ARCH_KMALLOC_FLAGS); |
1493 | |
1494 | if (INDEX_AC != INDEX_NODE) |
1495 | kmalloc_caches[INDEX_NODE] = |
1496 | create_kmalloc_cache("kmalloc-node", |
1497 | kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); |
1498 | |
1499 | slab_early_init = 0; |
1500 | |
1501 | /* 4) Replace the bootstrap head arrays */ |
1502 | { |
1503 | struct array_cache *ptr; |
1504 | |
1505 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1506 | |
1507 | memcpy(ptr, cpu_cache_get(kmem_cache), |
1508 | sizeof(struct arraycache_init)); |
1509 | /* |
1510 | * Do not assume that spinlocks can be initialized via memcpy: |
1511 | */ |
1512 | spin_lock_init(&ptr->lock); |
1513 | |
1514 | kmem_cache->array[smp_processor_id()] = ptr; |
1515 | |
1516 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1517 | |
1518 | BUG_ON(cpu_cache_get(kmalloc_caches[INDEX_AC]) |
1519 | != &initarray_generic.cache); |
1520 | memcpy(ptr, cpu_cache_get(kmalloc_caches[INDEX_AC]), |
1521 | sizeof(struct arraycache_init)); |
1522 | /* |
1523 | * Do not assume that spinlocks can be initialized via memcpy: |
1524 | */ |
1525 | spin_lock_init(&ptr->lock); |
1526 | |
1527 | kmalloc_caches[INDEX_AC]->array[smp_processor_id()] = ptr; |
1528 | } |
1529 | /* 5) Replace the bootstrap kmem_cache_node */ |
1530 | { |
1531 | int nid; |
1532 | |
1533 | for_each_online_node(nid) { |
1534 | init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); |
1535 | |
1536 | init_list(kmalloc_caches[INDEX_AC], |
1537 | &init_kmem_cache_node[SIZE_AC + nid], nid); |
1538 | |
1539 | if (INDEX_AC != INDEX_NODE) { |
1540 | init_list(kmalloc_caches[INDEX_NODE], |
1541 | &init_kmem_cache_node[SIZE_NODE + nid], nid); |
1542 | } |
1543 | } |
1544 | } |
1545 | |
1546 | create_kmalloc_caches(ARCH_KMALLOC_FLAGS); |
1547 | } |
1548 | |
1549 | void __init kmem_cache_init_late(void) |
1550 | { |
1551 | struct kmem_cache *cachep; |
1552 | |
1553 | slab_state = UP; |
1554 | |
1555 | /* 6) resize the head arrays to their final sizes */ |
1556 | mutex_lock(&slab_mutex); |
1557 | list_for_each_entry(cachep, &slab_caches, list) |
1558 | if (enable_cpucache(cachep, GFP_NOWAIT)) |
1559 | BUG(); |
1560 | mutex_unlock(&slab_mutex); |
1561 | |
1562 | /* Annotate slab for lockdep -- annotate the malloc caches */ |
1563 | init_lock_keys(); |
1564 | |
1565 | /* Done! */ |
1566 | slab_state = FULL; |
1567 | |
1568 | /* |
1569 | * Register a cpu startup notifier callback that initializes |
1570 | * cpu_cache_get for all new cpus |
1571 | */ |
1572 | register_cpu_notifier(&cpucache_notifier); |
1573 | |
1574 | #ifdef CONFIG_NUMA |
1575 | /* |
1576 | * Register a memory hotplug callback that initializes and frees |
1577 | * node. |
1578 | */ |
1579 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
1580 | #endif |
1581 | |
1582 | /* |
1583 | * The reap timers are started later, with a module init call: That part |
1584 | * of the kernel is not yet operational. |
1585 | */ |
1586 | } |
1587 | |
1588 | static int __init cpucache_init(void) |
1589 | { |
1590 | int cpu; |
1591 | |
1592 | /* |
1593 | * Register the timers that return unneeded pages to the page allocator |
1594 | */ |
1595 | for_each_online_cpu(cpu) |
1596 | start_cpu_timer(cpu); |
1597 | |
1598 | /* Done! */ |
1599 | slab_state = FULL; |
1600 | return 0; |
1601 | } |
1602 | __initcall(cpucache_init); |
1603 | |
1604 | static noinline void |
1605 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) |
1606 | { |
1607 | struct kmem_cache_node *n; |
1608 | struct page *page; |
1609 | unsigned long flags; |
1610 | int node; |
1611 | |
1612 | printk(KERN_WARNING |
1613 | "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
1614 | nodeid, gfpflags); |
1615 | printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", |
1616 | cachep->name, cachep->size, cachep->gfporder); |
1617 | |
1618 | for_each_online_node(node) { |
1619 | unsigned long active_objs = 0, num_objs = 0, free_objects = 0; |
1620 | unsigned long active_slabs = 0, num_slabs = 0; |
1621 | |
1622 | n = cachep->node[node]; |
1623 | if (!n) |
1624 | continue; |
1625 | |
1626 | spin_lock_irqsave(&n->list_lock, flags); |
1627 | list_for_each_entry(page, &n->slabs_full, lru) { |
1628 | active_objs += cachep->num; |
1629 | active_slabs++; |
1630 | } |
1631 | list_for_each_entry(page, &n->slabs_partial, lru) { |
1632 | active_objs += page->active; |
1633 | active_slabs++; |
1634 | } |
1635 | list_for_each_entry(page, &n->slabs_free, lru) |
1636 | num_slabs++; |
1637 | |
1638 | free_objects += n->free_objects; |
1639 | spin_unlock_irqrestore(&n->list_lock, flags); |
1640 | |
1641 | num_slabs += active_slabs; |
1642 | num_objs = num_slabs * cachep->num; |
1643 | printk(KERN_WARNING |
1644 | " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", |
1645 | node, active_slabs, num_slabs, active_objs, num_objs, |
1646 | free_objects); |
1647 | } |
1648 | } |
1649 | |
1650 | /* |
1651 | * Interface to system's page allocator. No need to hold the cache-lock. |
1652 | * |
1653 | * If we requested dmaable memory, we will get it. Even if we |
1654 | * did not request dmaable memory, we might get it, but that |
1655 | * would be relatively rare and ignorable. |
1656 | */ |
1657 | static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, |
1658 | int nodeid) |
1659 | { |
1660 | struct page *page; |
1661 | int nr_pages; |
1662 | |
1663 | flags |= cachep->allocflags; |
1664 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1665 | flags |= __GFP_RECLAIMABLE; |
1666 | |
1667 | page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); |
1668 | if (!page) { |
1669 | if (!(flags & __GFP_NOWARN) && printk_ratelimit()) |
1670 | slab_out_of_memory(cachep, flags, nodeid); |
1671 | return NULL; |
1672 | } |
1673 | |
1674 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ |
1675 | if (unlikely(page->pfmemalloc)) |
1676 | pfmemalloc_active = true; |
1677 | |
1678 | nr_pages = (1 << cachep->gfporder); |
1679 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1680 | add_zone_page_state(page_zone(page), |
1681 | NR_SLAB_RECLAIMABLE, nr_pages); |
1682 | else |
1683 | add_zone_page_state(page_zone(page), |
1684 | NR_SLAB_UNRECLAIMABLE, nr_pages); |
1685 | __SetPageSlab(page); |
1686 | if (page->pfmemalloc) |
1687 | SetPageSlabPfmemalloc(page); |
1688 | memcg_bind_pages(cachep, cachep->gfporder); |
1689 | |
1690 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { |
1691 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); |
1692 | |
1693 | if (cachep->ctor) |
1694 | kmemcheck_mark_uninitialized_pages(page, nr_pages); |
1695 | else |
1696 | kmemcheck_mark_unallocated_pages(page, nr_pages); |
1697 | } |
1698 | |
1699 | return page; |
1700 | } |
1701 | |
1702 | /* |
1703 | * Interface to system's page release. |
1704 | */ |
1705 | static void kmem_freepages(struct kmem_cache *cachep, struct page *page) |
1706 | { |
1707 | const unsigned long nr_freed = (1 << cachep->gfporder); |
1708 | |
1709 | kmemcheck_free_shadow(page, cachep->gfporder); |
1710 | |
1711 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1712 | sub_zone_page_state(page_zone(page), |
1713 | NR_SLAB_RECLAIMABLE, nr_freed); |
1714 | else |
1715 | sub_zone_page_state(page_zone(page), |
1716 | NR_SLAB_UNRECLAIMABLE, nr_freed); |
1717 | |
1718 | BUG_ON(!PageSlab(page)); |
1719 | __ClearPageSlabPfmemalloc(page); |
1720 | __ClearPageSlab(page); |
1721 | page_mapcount_reset(page); |
1722 | page->mapping = NULL; |
1723 | |
1724 | memcg_release_pages(cachep, cachep->gfporder); |
1725 | if (current->reclaim_state) |
1726 | current->reclaim_state->reclaimed_slab += nr_freed; |
1727 | __free_memcg_kmem_pages(page, cachep->gfporder); |
1728 | } |
1729 | |
1730 | static void kmem_rcu_free(struct rcu_head *head) |
1731 | { |
1732 | struct kmem_cache *cachep; |
1733 | struct page *page; |
1734 | |
1735 | page = container_of(head, struct page, rcu_head); |
1736 | cachep = page->slab_cache; |
1737 | |
1738 | kmem_freepages(cachep, page); |
1739 | } |
1740 | |
1741 | #if DEBUG |
1742 | |
1743 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1744 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, |
1745 | unsigned long caller) |
1746 | { |
1747 | int size = cachep->object_size; |
1748 | |
1749 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; |
1750 | |
1751 | if (size < 5 * sizeof(unsigned long)) |
1752 | return; |
1753 | |
1754 | *addr++ = 0x12345678; |
1755 | *addr++ = caller; |
1756 | *addr++ = smp_processor_id(); |
1757 | size -= 3 * sizeof(unsigned long); |
1758 | { |
1759 | unsigned long *sptr = &caller; |
1760 | unsigned long svalue; |
1761 | |
1762 | while (!kstack_end(sptr)) { |
1763 | svalue = *sptr++; |
1764 | if (kernel_text_address(svalue)) { |
1765 | *addr++ = svalue; |
1766 | size -= sizeof(unsigned long); |
1767 | if (size <= sizeof(unsigned long)) |
1768 | break; |
1769 | } |
1770 | } |
1771 | |
1772 | } |
1773 | *addr++ = 0x87654321; |
1774 | } |
1775 | #endif |
1776 | |
1777 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) |
1778 | { |
1779 | int size = cachep->object_size; |
1780 | addr = &((char *)addr)[obj_offset(cachep)]; |
1781 | |
1782 | memset(addr, val, size); |
1783 | *(unsigned char *)(addr + size - 1) = POISON_END; |
1784 | } |
1785 | |
1786 | static void dump_line(char *data, int offset, int limit) |
1787 | { |
1788 | int i; |
1789 | unsigned char error = 0; |
1790 | int bad_count = 0; |
1791 | |
1792 | printk(KERN_ERR "%03x: ", offset); |
1793 | for (i = 0; i < limit; i++) { |
1794 | if (data[offset + i] != POISON_FREE) { |
1795 | error = data[offset + i]; |
1796 | bad_count++; |
1797 | } |
1798 | } |
1799 | print_hex_dump(KERN_CONT, "", 0, 16, 1, |
1800 | &data[offset], limit, 1); |
1801 | |
1802 | if (bad_count == 1) { |
1803 | error ^= POISON_FREE; |
1804 | if (!(error & (error - 1))) { |
1805 | printk(KERN_ERR "Single bit error detected. Probably " |
1806 | "bad RAM.\n"); |
1807 | #ifdef CONFIG_X86 |
1808 | printk(KERN_ERR "Run memtest86+ or a similar memory " |
1809 | "test tool.\n"); |
1810 | #else |
1811 | printk(KERN_ERR "Run a memory test tool.\n"); |
1812 | #endif |
1813 | } |
1814 | } |
1815 | } |
1816 | #endif |
1817 | |
1818 | #if DEBUG |
1819 | |
1820 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) |
1821 | { |
1822 | int i, size; |
1823 | char *realobj; |
1824 | |
1825 | if (cachep->flags & SLAB_RED_ZONE) { |
1826 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", |
1827 | *dbg_redzone1(cachep, objp), |
1828 | *dbg_redzone2(cachep, objp)); |
1829 | } |
1830 | |
1831 | if (cachep->flags & SLAB_STORE_USER) { |
1832 | printk(KERN_ERR "Last user: [<%p>](%pSR)\n", |
1833 | *dbg_userword(cachep, objp), |
1834 | *dbg_userword(cachep, objp)); |
1835 | } |
1836 | realobj = (char *)objp + obj_offset(cachep); |
1837 | size = cachep->object_size; |
1838 | for (i = 0; i < size && lines; i += 16, lines--) { |
1839 | int limit; |
1840 | limit = 16; |
1841 | if (i + limit > size) |
1842 | limit = size - i; |
1843 | dump_line(realobj, i, limit); |
1844 | } |
1845 | } |
1846 | |
1847 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) |
1848 | { |
1849 | char *realobj; |
1850 | int size, i; |
1851 | int lines = 0; |
1852 | |
1853 | realobj = (char *)objp + obj_offset(cachep); |
1854 | size = cachep->object_size; |
1855 | |
1856 | for (i = 0; i < size; i++) { |
1857 | char exp = POISON_FREE; |
1858 | if (i == size - 1) |
1859 | exp = POISON_END; |
1860 | if (realobj[i] != exp) { |
1861 | int limit; |
1862 | /* Mismatch ! */ |
1863 | /* Print header */ |
1864 | if (lines == 0) { |
1865 | printk(KERN_ERR |
1866 | "Slab corruption (%s): %s start=%p, len=%d\n", |
1867 | print_tainted(), cachep->name, realobj, size); |
1868 | print_objinfo(cachep, objp, 0); |
1869 | } |
1870 | /* Hexdump the affected line */ |
1871 | i = (i / 16) * 16; |
1872 | limit = 16; |
1873 | if (i + limit > size) |
1874 | limit = size - i; |
1875 | dump_line(realobj, i, limit); |
1876 | i += 16; |
1877 | lines++; |
1878 | /* Limit to 5 lines */ |
1879 | if (lines > 5) |
1880 | break; |
1881 | } |
1882 | } |
1883 | if (lines != 0) { |
1884 | /* Print some data about the neighboring objects, if they |
1885 | * exist: |
1886 | */ |
1887 | struct page *page = virt_to_head_page(objp); |
1888 | unsigned int objnr; |
1889 | |
1890 | objnr = obj_to_index(cachep, page, objp); |
1891 | if (objnr) { |
1892 | objp = index_to_obj(cachep, page, objnr - 1); |
1893 | realobj = (char *)objp + obj_offset(cachep); |
1894 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
1895 | realobj, size); |
1896 | print_objinfo(cachep, objp, 2); |
1897 | } |
1898 | if (objnr + 1 < cachep->num) { |
1899 | objp = index_to_obj(cachep, page, objnr + 1); |
1900 | realobj = (char *)objp + obj_offset(cachep); |
1901 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
1902 | realobj, size); |
1903 | print_objinfo(cachep, objp, 2); |
1904 | } |
1905 | } |
1906 | } |
1907 | #endif |
1908 | |
1909 | #if DEBUG |
1910 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
1911 | struct page *page) |
1912 | { |
1913 | int i; |
1914 | for (i = 0; i < cachep->num; i++) { |
1915 | void *objp = index_to_obj(cachep, page, i); |
1916 | |
1917 | if (cachep->flags & SLAB_POISON) { |
1918 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1919 | if (cachep->size % PAGE_SIZE == 0 && |
1920 | OFF_SLAB(cachep)) |
1921 | kernel_map_pages(virt_to_page(objp), |
1922 | cachep->size / PAGE_SIZE, 1); |
1923 | else |
1924 | check_poison_obj(cachep, objp); |
1925 | #else |
1926 | check_poison_obj(cachep, objp); |
1927 | #endif |
1928 | } |
1929 | if (cachep->flags & SLAB_RED_ZONE) { |
1930 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
1931 | slab_error(cachep, "start of a freed object " |
1932 | "was overwritten"); |
1933 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
1934 | slab_error(cachep, "end of a freed object " |
1935 | "was overwritten"); |
1936 | } |
1937 | } |
1938 | } |
1939 | #else |
1940 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
1941 | struct page *page) |
1942 | { |
1943 | } |
1944 | #endif |
1945 | |
1946 | /** |
1947 | * slab_destroy - destroy and release all objects in a slab |
1948 | * @cachep: cache pointer being destroyed |
1949 | * @slabp: slab pointer being destroyed |
1950 | * |
1951 | * Destroy all the objs in a slab, and release the mem back to the system. |
1952 | * Before calling the slab must have been unlinked from the cache. The |
1953 | * cache-lock is not held/needed. |
1954 | */ |
1955 | static void slab_destroy(struct kmem_cache *cachep, struct page *page) |
1956 | { |
1957 | void *freelist; |
1958 | |
1959 | freelist = page->freelist; |
1960 | slab_destroy_debugcheck(cachep, page); |
1961 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { |
1962 | struct rcu_head *head; |
1963 | |
1964 | /* |
1965 | * RCU free overloads the RCU head over the LRU. |
1966 | * slab_page has been overloeaded over the LRU, |
1967 | * however it is not used from now on so that |
1968 | * we can use it safely. |
1969 | */ |
1970 | head = (void *)&page->rcu_head; |
1971 | call_rcu(head, kmem_rcu_free); |
1972 | |
1973 | } else { |
1974 | kmem_freepages(cachep, page); |
1975 | } |
1976 | |
1977 | /* |
1978 | * From now on, we don't use freelist |
1979 | * although actual page can be freed in rcu context |
1980 | */ |
1981 | if (OFF_SLAB(cachep)) |
1982 | kmem_cache_free(cachep->freelist_cache, freelist); |
1983 | } |
1984 | |
1985 | /** |
1986 | * calculate_slab_order - calculate size (page order) of slabs |
1987 | * @cachep: pointer to the cache that is being created |
1988 | * @size: size of objects to be created in this cache. |
1989 | * @align: required alignment for the objects. |
1990 | * @flags: slab allocation flags |
1991 | * |
1992 | * Also calculates the number of objects per slab. |
1993 | * |
1994 | * This could be made much more intelligent. For now, try to avoid using |
1995 | * high order pages for slabs. When the gfp() functions are more friendly |
1996 | * towards high-order requests, this should be changed. |
1997 | */ |
1998 | static size_t calculate_slab_order(struct kmem_cache *cachep, |
1999 | size_t size, size_t align, unsigned long flags) |
2000 | { |
2001 | unsigned long offslab_limit; |
2002 | size_t left_over = 0; |
2003 | int gfporder; |
2004 | |
2005 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { |
2006 | unsigned int num; |
2007 | size_t remainder; |
2008 | |
2009 | cache_estimate(gfporder, size, align, flags, &remainder, &num); |
2010 | if (!num) |
2011 | continue; |
2012 | |
2013 | if (flags & CFLGS_OFF_SLAB) { |
2014 | /* |
2015 | * Max number of objs-per-slab for caches which |
2016 | * use off-slab slabs. Needed to avoid a possible |
2017 | * looping condition in cache_grow(). |
2018 | */ |
2019 | offslab_limit = size; |
2020 | offslab_limit /= sizeof(unsigned int); |
2021 | |
2022 | if (num > offslab_limit) |
2023 | break; |
2024 | } |
2025 | |
2026 | /* Found something acceptable - save it away */ |
2027 | cachep->num = num; |
2028 | cachep->gfporder = gfporder; |
2029 | left_over = remainder; |
2030 | |
2031 | /* |
2032 | * A VFS-reclaimable slab tends to have most allocations |
2033 | * as GFP_NOFS and we really don't want to have to be allocating |
2034 | * higher-order pages when we are unable to shrink dcache. |
2035 | */ |
2036 | if (flags & SLAB_RECLAIM_ACCOUNT) |
2037 | break; |
2038 | |
2039 | /* |
2040 | * Large number of objects is good, but very large slabs are |
2041 | * currently bad for the gfp()s. |
2042 | */ |
2043 | if (gfporder >= slab_max_order) |
2044 | break; |
2045 | |
2046 | /* |
2047 | * Acceptable internal fragmentation? |
2048 | */ |
2049 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) |
2050 | break; |
2051 | } |
2052 | return left_over; |
2053 | } |
2054 | |
2055 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) |
2056 | { |
2057 | if (slab_state >= FULL) |
2058 | return enable_cpucache(cachep, gfp); |
2059 | |
2060 | if (slab_state == DOWN) { |
2061 | /* |
2062 | * Note: Creation of first cache (kmem_cache). |
2063 | * The setup_node is taken care |
2064 | * of by the caller of __kmem_cache_create |
2065 | */ |
2066 | cachep->array[smp_processor_id()] = &initarray_generic.cache; |
2067 | slab_state = PARTIAL; |
2068 | } else if (slab_state == PARTIAL) { |
2069 | /* |
2070 | * Note: the second kmem_cache_create must create the cache |
2071 | * that's used by kmalloc(24), otherwise the creation of |
2072 | * further caches will BUG(). |
2073 | */ |
2074 | cachep->array[smp_processor_id()] = &initarray_generic.cache; |
2075 | |
2076 | /* |
2077 | * If the cache that's used by kmalloc(sizeof(kmem_cache_node)) is |
2078 | * the second cache, then we need to set up all its node/, |
2079 | * otherwise the creation of further caches will BUG(). |
2080 | */ |
2081 | set_up_node(cachep, SIZE_AC); |
2082 | if (INDEX_AC == INDEX_NODE) |
2083 | slab_state = PARTIAL_NODE; |
2084 | else |
2085 | slab_state = PARTIAL_ARRAYCACHE; |
2086 | } else { |
2087 | /* Remaining boot caches */ |
2088 | cachep->array[smp_processor_id()] = |
2089 | kmalloc(sizeof(struct arraycache_init), gfp); |
2090 | |
2091 | if (slab_state == PARTIAL_ARRAYCACHE) { |
2092 | set_up_node(cachep, SIZE_NODE); |
2093 | slab_state = PARTIAL_NODE; |
2094 | } else { |
2095 | int node; |
2096 | for_each_online_node(node) { |
2097 | cachep->node[node] = |
2098 | kmalloc_node(sizeof(struct kmem_cache_node), |
2099 | gfp, node); |
2100 | BUG_ON(!cachep->node[node]); |
2101 | kmem_cache_node_init(cachep->node[node]); |
2102 | } |
2103 | } |
2104 | } |
2105 | cachep->node[numa_mem_id()]->next_reap = |
2106 | jiffies + REAPTIMEOUT_LIST3 + |
2107 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
2108 | |
2109 | cpu_cache_get(cachep)->avail = 0; |
2110 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
2111 | cpu_cache_get(cachep)->batchcount = 1; |
2112 | cpu_cache_get(cachep)->touched = 0; |
2113 | cachep->batchcount = 1; |
2114 | cachep->limit = BOOT_CPUCACHE_ENTRIES; |
2115 | return 0; |
2116 | } |
2117 | |
2118 | /** |
2119 | * __kmem_cache_create - Create a cache. |
2120 | * @cachep: cache management descriptor |
2121 | * @flags: SLAB flags |
2122 | * |
2123 | * Returns a ptr to the cache on success, NULL on failure. |
2124 | * Cannot be called within a int, but can be interrupted. |
2125 | * The @ctor is run when new pages are allocated by the cache. |
2126 | * |
2127 | * The flags are |
2128 | * |
2129 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
2130 | * to catch references to uninitialised memory. |
2131 | * |
2132 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
2133 | * for buffer overruns. |
2134 | * |
2135 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
2136 | * cacheline. This can be beneficial if you're counting cycles as closely |
2137 | * as davem. |
2138 | */ |
2139 | int |
2140 | __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) |
2141 | { |
2142 | size_t left_over, freelist_size, ralign; |
2143 | gfp_t gfp; |
2144 | int err; |
2145 | size_t size = cachep->size; |
2146 | |
2147 | #if DEBUG |
2148 | #if FORCED_DEBUG |
2149 | /* |
2150 | * Enable redzoning and last user accounting, except for caches with |
2151 | * large objects, if the increased size would increase the object size |
2152 | * above the next power of two: caches with object sizes just above a |
2153 | * power of two have a significant amount of internal fragmentation. |
2154 | */ |
2155 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + |
2156 | 2 * sizeof(unsigned long long))) |
2157 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; |
2158 | if (!(flags & SLAB_DESTROY_BY_RCU)) |
2159 | flags |= SLAB_POISON; |
2160 | #endif |
2161 | if (flags & SLAB_DESTROY_BY_RCU) |
2162 | BUG_ON(flags & SLAB_POISON); |
2163 | #endif |
2164 | |
2165 | /* |
2166 | * Check that size is in terms of words. This is needed to avoid |
2167 | * unaligned accesses for some archs when redzoning is used, and makes |
2168 | * sure any on-slab bufctl's are also correctly aligned. |
2169 | */ |
2170 | if (size & (BYTES_PER_WORD - 1)) { |
2171 | size += (BYTES_PER_WORD - 1); |
2172 | size &= ~(BYTES_PER_WORD - 1); |
2173 | } |
2174 | |
2175 | /* |
2176 | * Redzoning and user store require word alignment or possibly larger. |
2177 | * Note this will be overridden by architecture or caller mandated |
2178 | * alignment if either is greater than BYTES_PER_WORD. |
2179 | */ |
2180 | if (flags & SLAB_STORE_USER) |
2181 | ralign = BYTES_PER_WORD; |
2182 | |
2183 | if (flags & SLAB_RED_ZONE) { |
2184 | ralign = REDZONE_ALIGN; |
2185 | /* If redzoning, ensure that the second redzone is suitably |
2186 | * aligned, by adjusting the object size accordingly. */ |
2187 | size += REDZONE_ALIGN - 1; |
2188 | size &= ~(REDZONE_ALIGN - 1); |
2189 | } |
2190 | |
2191 | /* 3) caller mandated alignment */ |
2192 | if (ralign < cachep->align) { |
2193 | ralign = cachep->align; |
2194 | } |
2195 | /* disable debug if necessary */ |
2196 | if (ralign > __alignof__(unsigned long long)) |
2197 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2198 | /* |
2199 | * 4) Store it. |
2200 | */ |
2201 | cachep->align = ralign; |
2202 | |
2203 | if (slab_is_available()) |
2204 | gfp = GFP_KERNEL; |
2205 | else |
2206 | gfp = GFP_NOWAIT; |
2207 | |
2208 | setup_node_pointer(cachep); |
2209 | #if DEBUG |
2210 | |
2211 | /* |
2212 | * Both debugging options require word-alignment which is calculated |
2213 | * into align above. |
2214 | */ |
2215 | if (flags & SLAB_RED_ZONE) { |
2216 | /* add space for red zone words */ |
2217 | cachep->obj_offset += sizeof(unsigned long long); |
2218 | size += 2 * sizeof(unsigned long long); |
2219 | } |
2220 | if (flags & SLAB_STORE_USER) { |
2221 | /* user store requires one word storage behind the end of |
2222 | * the real object. But if the second red zone needs to be |
2223 | * aligned to 64 bits, we must allow that much space. |
2224 | */ |
2225 | if (flags & SLAB_RED_ZONE) |
2226 | size += REDZONE_ALIGN; |
2227 | else |
2228 | size += BYTES_PER_WORD; |
2229 | } |
2230 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
2231 | if (size >= kmalloc_size(INDEX_NODE + 1) |
2232 | && cachep->object_size > cache_line_size() |
2233 | && ALIGN(size, cachep->align) < PAGE_SIZE) { |
2234 | cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align); |
2235 | size = PAGE_SIZE; |
2236 | } |
2237 | #endif |
2238 | #endif |
2239 | |
2240 | /* |
2241 | * Determine if the slab management is 'on' or 'off' slab. |
2242 | * (bootstrapping cannot cope with offslab caches so don't do |
2243 | * it too early on. Always use on-slab management when |
2244 | * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) |
2245 | */ |
2246 | if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && |
2247 | !(flags & SLAB_NOLEAKTRACE)) |
2248 | /* |
2249 | * Size is large, assume best to place the slab management obj |
2250 | * off-slab (should allow better packing of objs). |
2251 | */ |
2252 | flags |= CFLGS_OFF_SLAB; |
2253 | |
2254 | size = ALIGN(size, cachep->align); |
2255 | |
2256 | left_over = calculate_slab_order(cachep, size, cachep->align, flags); |
2257 | |
2258 | if (!cachep->num) |
2259 | return -E2BIG; |
2260 | |
2261 | freelist_size = |
2262 | ALIGN(cachep->num * sizeof(unsigned int), cachep->align); |
2263 | |
2264 | /* |
2265 | * If the slab has been placed off-slab, and we have enough space then |
2266 | * move it on-slab. This is at the expense of any extra colouring. |
2267 | */ |
2268 | if (flags & CFLGS_OFF_SLAB && left_over >= freelist_size) { |
2269 | flags &= ~CFLGS_OFF_SLAB; |
2270 | left_over -= freelist_size; |
2271 | } |
2272 | |
2273 | if (flags & CFLGS_OFF_SLAB) { |
2274 | /* really off slab. No need for manual alignment */ |
2275 | freelist_size = cachep->num * sizeof(unsigned int); |
2276 | |
2277 | #ifdef CONFIG_PAGE_POISONING |
2278 | /* If we're going to use the generic kernel_map_pages() |
2279 | * poisoning, then it's going to smash the contents of |
2280 | * the redzone and userword anyhow, so switch them off. |
2281 | */ |
2282 | if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) |
2283 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2284 | #endif |
2285 | } |
2286 | |
2287 | cachep->colour_off = cache_line_size(); |
2288 | /* Offset must be a multiple of the alignment. */ |
2289 | if (cachep->colour_off < cachep->align) |
2290 | cachep->colour_off = cachep->align; |
2291 | cachep->colour = left_over / cachep->colour_off; |
2292 | cachep->freelist_size = freelist_size; |
2293 | cachep->flags = flags; |
2294 | cachep->allocflags = __GFP_COMP; |
2295 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) |
2296 | cachep->allocflags |= GFP_DMA; |
2297 | cachep->size = size; |
2298 | cachep->reciprocal_buffer_size = reciprocal_value(size); |
2299 | |
2300 | if (flags & CFLGS_OFF_SLAB) { |
2301 | cachep->freelist_cache = kmalloc_slab(freelist_size, 0u); |
2302 | /* |
2303 | * This is a possibility for one of the malloc_sizes caches. |
2304 | * But since we go off slab only for object size greater than |
2305 | * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, |
2306 | * this should not happen at all. |
2307 | * But leave a BUG_ON for some lucky dude. |
2308 | */ |
2309 | BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache)); |
2310 | } |
2311 | |
2312 | err = setup_cpu_cache(cachep, gfp); |
2313 | if (err) { |
2314 | __kmem_cache_shutdown(cachep); |
2315 | return err; |
2316 | } |
2317 | |
2318 | if (flags & SLAB_DEBUG_OBJECTS) { |
2319 | /* |
2320 | * Would deadlock through slab_destroy()->call_rcu()-> |
2321 | * debug_object_activate()->kmem_cache_alloc(). |
2322 | */ |
2323 | WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU); |
2324 | |
2325 | slab_set_debugobj_lock_classes(cachep); |
2326 | } else if (!OFF_SLAB(cachep) && !(flags & SLAB_DESTROY_BY_RCU)) |
2327 | on_slab_lock_classes(cachep); |
2328 | |
2329 | return 0; |
2330 | } |
2331 | |
2332 | #if DEBUG |
2333 | static void check_irq_off(void) |
2334 | { |
2335 | BUG_ON(!irqs_disabled()); |
2336 | } |
2337 | |
2338 | static void check_irq_on(void) |
2339 | { |
2340 | BUG_ON(irqs_disabled()); |
2341 | } |
2342 | |
2343 | static void check_spinlock_acquired(struct kmem_cache *cachep) |
2344 | { |
2345 | #ifdef CONFIG_SMP |
2346 | check_irq_off(); |
2347 | assert_spin_locked(&cachep->node[numa_mem_id()]->list_lock); |
2348 | #endif |
2349 | } |
2350 | |
2351 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) |
2352 | { |
2353 | #ifdef CONFIG_SMP |
2354 | check_irq_off(); |
2355 | assert_spin_locked(&cachep->node[node]->list_lock); |
2356 | #endif |
2357 | } |
2358 | |
2359 | #else |
2360 | #define check_irq_off() do { } while(0) |
2361 | #define check_irq_on() do { } while(0) |
2362 | #define check_spinlock_acquired(x) do { } while(0) |
2363 | #define check_spinlock_acquired_node(x, y) do { } while(0) |
2364 | #endif |
2365 | |
2366 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
2367 | struct array_cache *ac, |
2368 | int force, int node); |
2369 | |
2370 | static void do_drain(void *arg) |
2371 | { |
2372 | struct kmem_cache *cachep = arg; |
2373 | struct array_cache *ac; |
2374 | int node = numa_mem_id(); |
2375 | |
2376 | check_irq_off(); |
2377 | ac = cpu_cache_get(cachep); |
2378 | spin_lock(&cachep->node[node]->list_lock); |
2379 | free_block(cachep, ac->entry, ac->avail, node); |
2380 | spin_unlock(&cachep->node[node]->list_lock); |
2381 | ac->avail = 0; |
2382 | } |
2383 | |
2384 | static void drain_cpu_caches(struct kmem_cache *cachep) |
2385 | { |
2386 | struct kmem_cache_node *n; |
2387 | int node; |
2388 | |
2389 | on_each_cpu(do_drain, cachep, 1); |
2390 | check_irq_on(); |
2391 | for_each_online_node(node) { |
2392 | n = cachep->node[node]; |
2393 | if (n && n->alien) |
2394 | drain_alien_cache(cachep, n->alien); |
2395 | } |
2396 | |
2397 | for_each_online_node(node) { |
2398 | n = cachep->node[node]; |
2399 | if (n) |
2400 | drain_array(cachep, n, n->shared, 1, node); |
2401 | } |
2402 | } |
2403 | |
2404 | /* |
2405 | * Remove slabs from the list of free slabs. |
2406 | * Specify the number of slabs to drain in tofree. |
2407 | * |
2408 | * Returns the actual number of slabs released. |
2409 | */ |
2410 | static int drain_freelist(struct kmem_cache *cache, |
2411 | struct kmem_cache_node *n, int tofree) |
2412 | { |
2413 | struct list_head *p; |
2414 | int nr_freed; |
2415 | struct page *page; |
2416 | |
2417 | nr_freed = 0; |
2418 | while (nr_freed < tofree && !list_empty(&n->slabs_free)) { |
2419 | |
2420 | spin_lock_irq(&n->list_lock); |
2421 | p = n->slabs_free.prev; |
2422 | if (p == &n->slabs_free) { |
2423 | spin_unlock_irq(&n->list_lock); |
2424 | goto out; |
2425 | } |
2426 | |
2427 | page = list_entry(p, struct page, lru); |
2428 | #if DEBUG |
2429 | BUG_ON(page->active); |
2430 | #endif |
2431 | list_del(&page->lru); |
2432 | /* |
2433 | * Safe to drop the lock. The slab is no longer linked |
2434 | * to the cache. |
2435 | */ |
2436 | n->free_objects -= cache->num; |
2437 | spin_unlock_irq(&n->list_lock); |
2438 | slab_destroy(cache, page); |
2439 | nr_freed++; |
2440 | } |
2441 | out: |
2442 | return nr_freed; |
2443 | } |
2444 | |
2445 | /* Called with slab_mutex held to protect against cpu hotplug */ |
2446 | static int __cache_shrink(struct kmem_cache *cachep) |
2447 | { |
2448 | int ret = 0, i = 0; |
2449 | struct kmem_cache_node *n; |
2450 | |
2451 | drain_cpu_caches(cachep); |
2452 | |
2453 | check_irq_on(); |
2454 | for_each_online_node(i) { |
2455 | n = cachep->node[i]; |
2456 | if (!n) |
2457 | continue; |
2458 | |
2459 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
2460 | |
2461 | ret += !list_empty(&n->slabs_full) || |
2462 | !list_empty(&n->slabs_partial); |
2463 | } |
2464 | return (ret ? 1 : 0); |
2465 | } |
2466 | |
2467 | /** |
2468 | * kmem_cache_shrink - Shrink a cache. |
2469 | * @cachep: The cache to shrink. |
2470 | * |
2471 | * Releases as many slabs as possible for a cache. |
2472 | * To help debugging, a zero exit status indicates all slabs were released. |
2473 | */ |
2474 | int kmem_cache_shrink(struct kmem_cache *cachep) |
2475 | { |
2476 | int ret; |
2477 | BUG_ON(!cachep || in_interrupt()); |
2478 | |
2479 | get_online_cpus(); |
2480 | mutex_lock(&slab_mutex); |
2481 | ret = __cache_shrink(cachep); |
2482 | mutex_unlock(&slab_mutex); |
2483 | put_online_cpus(); |
2484 | return ret; |
2485 | } |
2486 | EXPORT_SYMBOL(kmem_cache_shrink); |
2487 | |
2488 | int __kmem_cache_shutdown(struct kmem_cache *cachep) |
2489 | { |
2490 | int i; |
2491 | struct kmem_cache_node *n; |
2492 | int rc = __cache_shrink(cachep); |
2493 | |
2494 | if (rc) |
2495 | return rc; |
2496 | |
2497 | for_each_online_cpu(i) |
2498 | kfree(cachep->array[i]); |
2499 | |
2500 | /* NUMA: free the node structures */ |
2501 | for_each_online_node(i) { |
2502 | n = cachep->node[i]; |
2503 | if (n) { |
2504 | kfree(n->shared); |
2505 | free_alien_cache(n->alien); |
2506 | kfree(n); |
2507 | } |
2508 | } |
2509 | return 0; |
2510 | } |
2511 | |
2512 | /* |
2513 | * Get the memory for a slab management obj. |
2514 | * For a slab cache when the slab descriptor is off-slab, slab descriptors |
2515 | * always come from malloc_sizes caches. The slab descriptor cannot |
2516 | * come from the same cache which is getting created because, |
2517 | * when we are searching for an appropriate cache for these |
2518 | * descriptors in kmem_cache_create, we search through the malloc_sizes array. |
2519 | * If we are creating a malloc_sizes cache here it would not be visible to |
2520 | * kmem_find_general_cachep till the initialization is complete. |
2521 | * Hence we cannot have freelist_cache same as the original cache. |
2522 | */ |
2523 | static void *alloc_slabmgmt(struct kmem_cache *cachep, |
2524 | struct page *page, int colour_off, |
2525 | gfp_t local_flags, int nodeid) |
2526 | { |
2527 | void *freelist; |
2528 | void *addr = page_address(page); |
2529 | |
2530 | if (OFF_SLAB(cachep)) { |
2531 | /* Slab management obj is off-slab. */ |
2532 | freelist = kmem_cache_alloc_node(cachep->freelist_cache, |
2533 | local_flags, nodeid); |
2534 | if (!freelist) |
2535 | return NULL; |
2536 | } else { |
2537 | freelist = addr + colour_off; |
2538 | colour_off += cachep->freelist_size; |
2539 | } |
2540 | page->active = 0; |
2541 | page->s_mem = addr + colour_off; |
2542 | return freelist; |
2543 | } |
2544 | |
2545 | static inline unsigned int *slab_freelist(struct page *page) |
2546 | { |
2547 | return (unsigned int *)(page->freelist); |
2548 | } |
2549 | |
2550 | static void cache_init_objs(struct kmem_cache *cachep, |
2551 | struct page *page) |
2552 | { |
2553 | int i; |
2554 | |
2555 | for (i = 0; i < cachep->num; i++) { |
2556 | void *objp = index_to_obj(cachep, page, i); |
2557 | #if DEBUG |
2558 | /* need to poison the objs? */ |
2559 | if (cachep->flags & SLAB_POISON) |
2560 | poison_obj(cachep, objp, POISON_FREE); |
2561 | if (cachep->flags & SLAB_STORE_USER) |
2562 | *dbg_userword(cachep, objp) = NULL; |
2563 | |
2564 | if (cachep->flags & SLAB_RED_ZONE) { |
2565 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2566 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2567 | } |
2568 | /* |
2569 | * Constructors are not allowed to allocate memory from the same |
2570 | * cache which they are a constructor for. Otherwise, deadlock. |
2571 | * They must also be threaded. |
2572 | */ |
2573 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) |
2574 | cachep->ctor(objp + obj_offset(cachep)); |
2575 | |
2576 | if (cachep->flags & SLAB_RED_ZONE) { |
2577 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2578 | slab_error(cachep, "constructor overwrote the" |
2579 | " end of an object"); |
2580 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2581 | slab_error(cachep, "constructor overwrote the" |
2582 | " start of an object"); |
2583 | } |
2584 | if ((cachep->size % PAGE_SIZE) == 0 && |
2585 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
2586 | kernel_map_pages(virt_to_page(objp), |
2587 | cachep->size / PAGE_SIZE, 0); |
2588 | #else |
2589 | if (cachep->ctor) |
2590 | cachep->ctor(objp); |
2591 | #endif |
2592 | slab_freelist(page)[i] = i; |
2593 | } |
2594 | } |
2595 | |
2596 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) |
2597 | { |
2598 | if (CONFIG_ZONE_DMA_FLAG) { |
2599 | if (flags & GFP_DMA) |
2600 | BUG_ON(!(cachep->allocflags & GFP_DMA)); |
2601 | else |
2602 | BUG_ON(cachep->allocflags & GFP_DMA); |
2603 | } |
2604 | } |
2605 | |
2606 | static void *slab_get_obj(struct kmem_cache *cachep, struct page *page, |
2607 | int nodeid) |
2608 | { |
2609 | void *objp; |
2610 | |
2611 | objp = index_to_obj(cachep, page, slab_freelist(page)[page->active]); |
2612 | page->active++; |
2613 | #if DEBUG |
2614 | WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); |
2615 | #endif |
2616 | |
2617 | return objp; |
2618 | } |
2619 | |
2620 | static void slab_put_obj(struct kmem_cache *cachep, struct page *page, |
2621 | void *objp, int nodeid) |
2622 | { |
2623 | unsigned int objnr = obj_to_index(cachep, page, objp); |
2624 | #if DEBUG |
2625 | unsigned int i; |
2626 | |
2627 | /* Verify that the slab belongs to the intended node */ |
2628 | WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); |
2629 | |
2630 | /* Verify double free bug */ |
2631 | for (i = page->active; i < cachep->num; i++) { |
2632 | if (slab_freelist(page)[i] == objnr) { |
2633 | printk(KERN_ERR "slab: double free detected in cache " |
2634 | "'%s', objp %p\n", cachep->name, objp); |
2635 | BUG(); |
2636 | } |
2637 | } |
2638 | #endif |
2639 | page->active--; |
2640 | slab_freelist(page)[page->active] = objnr; |
2641 | } |
2642 | |
2643 | /* |
2644 | * Map pages beginning at addr to the given cache and slab. This is required |
2645 | * for the slab allocator to be able to lookup the cache and slab of a |
2646 | * virtual address for kfree, ksize, and slab debugging. |
2647 | */ |
2648 | static void slab_map_pages(struct kmem_cache *cache, struct page *page, |
2649 | void *freelist) |
2650 | { |
2651 | page->slab_cache = cache; |
2652 | page->freelist = freelist; |
2653 | } |
2654 | |
2655 | /* |
2656 | * Grow (by 1) the number of slabs within a cache. This is called by |
2657 | * kmem_cache_alloc() when there are no active objs left in a cache. |
2658 | */ |
2659 | static int cache_grow(struct kmem_cache *cachep, |
2660 | gfp_t flags, int nodeid, struct page *page) |
2661 | { |
2662 | void *freelist; |
2663 | size_t offset; |
2664 | gfp_t local_flags; |
2665 | struct kmem_cache_node *n; |
2666 | |
2667 | /* |
2668 | * Be lazy and only check for valid flags here, keeping it out of the |
2669 | * critical path in kmem_cache_alloc(). |
2670 | */ |
2671 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
2672 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
2673 | |
2674 | /* Take the node list lock to change the colour_next on this node */ |
2675 | check_irq_off(); |
2676 | n = cachep->node[nodeid]; |
2677 | spin_lock(&n->list_lock); |
2678 | |
2679 | /* Get colour for the slab, and cal the next value. */ |
2680 | offset = n->colour_next; |
2681 | n->colour_next++; |
2682 | if (n->colour_next >= cachep->colour) |
2683 | n->colour_next = 0; |
2684 | spin_unlock(&n->list_lock); |
2685 | |
2686 | offset *= cachep->colour_off; |
2687 | |
2688 | if (local_flags & __GFP_WAIT) |
2689 | local_irq_enable(); |
2690 | |
2691 | /* |
2692 | * The test for missing atomic flag is performed here, rather than |
2693 | * the more obvious place, simply to reduce the critical path length |
2694 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they |
2695 | * will eventually be caught here (where it matters). |
2696 | */ |
2697 | kmem_flagcheck(cachep, flags); |
2698 | |
2699 | /* |
2700 | * Get mem for the objs. Attempt to allocate a physical page from |
2701 | * 'nodeid'. |
2702 | */ |
2703 | if (!page) |
2704 | page = kmem_getpages(cachep, local_flags, nodeid); |
2705 | if (!page) |
2706 | goto failed; |
2707 | |
2708 | /* Get slab management. */ |
2709 | freelist = alloc_slabmgmt(cachep, page, offset, |
2710 | local_flags & ~GFP_CONSTRAINT_MASK, nodeid); |
2711 | if (!freelist) |
2712 | goto opps1; |
2713 | |
2714 | slab_map_pages(cachep, page, freelist); |
2715 | |
2716 | cache_init_objs(cachep, page); |
2717 | |
2718 | if (local_flags & __GFP_WAIT) |
2719 | local_irq_disable(); |
2720 | check_irq_off(); |
2721 | spin_lock(&n->list_lock); |
2722 | |
2723 | /* Make slab active. */ |
2724 | list_add_tail(&page->lru, &(n->slabs_free)); |
2725 | STATS_INC_GROWN(cachep); |
2726 | n->free_objects += cachep->num; |
2727 | spin_unlock(&n->list_lock); |
2728 | return 1; |
2729 | opps1: |
2730 | kmem_freepages(cachep, page); |
2731 | failed: |
2732 | if (local_flags & __GFP_WAIT) |
2733 | local_irq_disable(); |
2734 | return 0; |
2735 | } |
2736 | |
2737 | #if DEBUG |
2738 | |
2739 | /* |
2740 | * Perform extra freeing checks: |
2741 | * - detect bad pointers. |
2742 | * - POISON/RED_ZONE checking |
2743 | */ |
2744 | static void kfree_debugcheck(const void *objp) |
2745 | { |
2746 | if (!virt_addr_valid(objp)) { |
2747 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
2748 | (unsigned long)objp); |
2749 | BUG(); |
2750 | } |
2751 | } |
2752 | |
2753 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) |
2754 | { |
2755 | unsigned long long redzone1, redzone2; |
2756 | |
2757 | redzone1 = *dbg_redzone1(cache, obj); |
2758 | redzone2 = *dbg_redzone2(cache, obj); |
2759 | |
2760 | /* |
2761 | * Redzone is ok. |
2762 | */ |
2763 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) |
2764 | return; |
2765 | |
2766 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) |
2767 | slab_error(cache, "double free detected"); |
2768 | else |
2769 | slab_error(cache, "memory outside object was overwritten"); |
2770 | |
2771 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", |
2772 | obj, redzone1, redzone2); |
2773 | } |
2774 | |
2775 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, |
2776 | unsigned long caller) |
2777 | { |
2778 | unsigned int objnr; |
2779 | struct page *page; |
2780 | |
2781 | BUG_ON(virt_to_cache(objp) != cachep); |
2782 | |
2783 | objp -= obj_offset(cachep); |
2784 | kfree_debugcheck(objp); |
2785 | page = virt_to_head_page(objp); |
2786 | |
2787 | if (cachep->flags & SLAB_RED_ZONE) { |
2788 | verify_redzone_free(cachep, objp); |
2789 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2790 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2791 | } |
2792 | if (cachep->flags & SLAB_STORE_USER) |
2793 | *dbg_userword(cachep, objp) = (void *)caller; |
2794 | |
2795 | objnr = obj_to_index(cachep, page, objp); |
2796 | |
2797 | BUG_ON(objnr >= cachep->num); |
2798 | BUG_ON(objp != index_to_obj(cachep, page, objnr)); |
2799 | |
2800 | if (cachep->flags & SLAB_POISON) { |
2801 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2802 | if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { |
2803 | store_stackinfo(cachep, objp, caller); |
2804 | kernel_map_pages(virt_to_page(objp), |
2805 | cachep->size / PAGE_SIZE, 0); |
2806 | } else { |
2807 | poison_obj(cachep, objp, POISON_FREE); |
2808 | } |
2809 | #else |
2810 | poison_obj(cachep, objp, POISON_FREE); |
2811 | #endif |
2812 | } |
2813 | return objp; |
2814 | } |
2815 | |
2816 | #else |
2817 | #define kfree_debugcheck(x) do { } while(0) |
2818 | #define cache_free_debugcheck(x,objp,z) (objp) |
2819 | #endif |
2820 | |
2821 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, |
2822 | bool force_refill) |
2823 | { |
2824 | int batchcount; |
2825 | struct kmem_cache_node *n; |
2826 | struct array_cache *ac; |
2827 | int node; |
2828 | |
2829 | check_irq_off(); |
2830 | node = numa_mem_id(); |
2831 | if (unlikely(force_refill)) |
2832 | goto force_grow; |
2833 | retry: |
2834 | ac = cpu_cache_get(cachep); |
2835 | batchcount = ac->batchcount; |
2836 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
2837 | /* |
2838 | * If there was little recent activity on this cache, then |
2839 | * perform only a partial refill. Otherwise we could generate |
2840 | * refill bouncing. |
2841 | */ |
2842 | batchcount = BATCHREFILL_LIMIT; |
2843 | } |
2844 | n = cachep->node[node]; |
2845 | |
2846 | BUG_ON(ac->avail > 0 || !n); |
2847 | spin_lock(&n->list_lock); |
2848 | |
2849 | /* See if we can refill from the shared array */ |
2850 | if (n->shared && transfer_objects(ac, n->shared, batchcount)) { |
2851 | n->shared->touched = 1; |
2852 | goto alloc_done; |
2853 | } |
2854 | |
2855 | while (batchcount > 0) { |
2856 | struct list_head *entry; |
2857 | struct page *page; |
2858 | /* Get slab alloc is to come from. */ |
2859 | entry = n->slabs_partial.next; |
2860 | if (entry == &n->slabs_partial) { |
2861 | n->free_touched = 1; |
2862 | entry = n->slabs_free.next; |
2863 | if (entry == &n->slabs_free) |
2864 | goto must_grow; |
2865 | } |
2866 | |
2867 | page = list_entry(entry, struct page, lru); |
2868 | check_spinlock_acquired(cachep); |
2869 | |
2870 | /* |
2871 | * The slab was either on partial or free list so |
2872 | * there must be at least one object available for |
2873 | * allocation. |
2874 | */ |
2875 | BUG_ON(page->active >= cachep->num); |
2876 | |
2877 | while (page->active < cachep->num && batchcount--) { |
2878 | STATS_INC_ALLOCED(cachep); |
2879 | STATS_INC_ACTIVE(cachep); |
2880 | STATS_SET_HIGH(cachep); |
2881 | |
2882 | ac_put_obj(cachep, ac, slab_get_obj(cachep, page, |
2883 | node)); |
2884 | } |
2885 | |
2886 | /* move slabp to correct slabp list: */ |
2887 | list_del(&page->lru); |
2888 | if (page->active == cachep->num) |
2889 | list_add(&page->list, &n->slabs_full); |
2890 | else |
2891 | list_add(&page->list, &n->slabs_partial); |
2892 | } |
2893 | |
2894 | must_grow: |
2895 | n->free_objects -= ac->avail; |
2896 | alloc_done: |
2897 | spin_unlock(&n->list_lock); |
2898 | |
2899 | if (unlikely(!ac->avail)) { |
2900 | int x; |
2901 | force_grow: |
2902 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); |
2903 | |
2904 | /* cache_grow can reenable interrupts, then ac could change. */ |
2905 | ac = cpu_cache_get(cachep); |
2906 | node = numa_mem_id(); |
2907 | |
2908 | /* no objects in sight? abort */ |
2909 | if (!x && (ac->avail == 0 || force_refill)) |
2910 | return NULL; |
2911 | |
2912 | if (!ac->avail) /* objects refilled by interrupt? */ |
2913 | goto retry; |
2914 | } |
2915 | ac->touched = 1; |
2916 | |
2917 | return ac_get_obj(cachep, ac, flags, force_refill); |
2918 | } |
2919 | |
2920 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, |
2921 | gfp_t flags) |
2922 | { |
2923 | might_sleep_if(flags & __GFP_WAIT); |
2924 | #if DEBUG |
2925 | kmem_flagcheck(cachep, flags); |
2926 | #endif |
2927 | } |
2928 | |
2929 | #if DEBUG |
2930 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, |
2931 | gfp_t flags, void *objp, unsigned long caller) |
2932 | { |
2933 | if (!objp) |
2934 | return objp; |
2935 | if (cachep->flags & SLAB_POISON) { |
2936 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2937 | if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
2938 | kernel_map_pages(virt_to_page(objp), |
2939 | cachep->size / PAGE_SIZE, 1); |
2940 | else |
2941 | check_poison_obj(cachep, objp); |
2942 | #else |
2943 | check_poison_obj(cachep, objp); |
2944 | #endif |
2945 | poison_obj(cachep, objp, POISON_INUSE); |
2946 | } |
2947 | if (cachep->flags & SLAB_STORE_USER) |
2948 | *dbg_userword(cachep, objp) = (void *)caller; |
2949 | |
2950 | if (cachep->flags & SLAB_RED_ZONE) { |
2951 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || |
2952 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
2953 | slab_error(cachep, "double free, or memory outside" |
2954 | " object was overwritten"); |
2955 | printk(KERN_ERR |
2956 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", |
2957 | objp, *dbg_redzone1(cachep, objp), |
2958 | *dbg_redzone2(cachep, objp)); |
2959 | } |
2960 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
2961 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
2962 | } |
2963 | objp += obj_offset(cachep); |
2964 | if (cachep->ctor && cachep->flags & SLAB_POISON) |
2965 | cachep->ctor(objp); |
2966 | if (ARCH_SLAB_MINALIGN && |
2967 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { |
2968 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", |
2969 | objp, (int)ARCH_SLAB_MINALIGN); |
2970 | } |
2971 | return objp; |
2972 | } |
2973 | #else |
2974 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
2975 | #endif |
2976 | |
2977 | static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) |
2978 | { |
2979 | if (cachep == kmem_cache) |
2980 | return false; |
2981 | |
2982 | return should_failslab(cachep->object_size, flags, cachep->flags); |
2983 | } |
2984 | |
2985 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
2986 | { |
2987 | void *objp; |
2988 | struct array_cache *ac; |
2989 | bool force_refill = false; |
2990 | |
2991 | check_irq_off(); |
2992 | |
2993 | ac = cpu_cache_get(cachep); |
2994 | if (likely(ac->avail)) { |
2995 | ac->touched = 1; |
2996 | objp = ac_get_obj(cachep, ac, flags, false); |
2997 | |
2998 | /* |
2999 | * Allow for the possibility all avail objects are not allowed |
3000 | * by the current flags |
3001 | */ |
3002 | if (objp) { |
3003 | STATS_INC_ALLOCHIT(cachep); |
3004 | goto out; |
3005 | } |
3006 | force_refill = true; |
3007 | } |
3008 | |
3009 | STATS_INC_ALLOCMISS(cachep); |
3010 | objp = cache_alloc_refill(cachep, flags, force_refill); |
3011 | /* |
3012 | * the 'ac' may be updated by cache_alloc_refill(), |
3013 | * and kmemleak_erase() requires its correct value. |
3014 | */ |
3015 | ac = cpu_cache_get(cachep); |
3016 | |
3017 | out: |
3018 | /* |
3019 | * To avoid a false negative, if an object that is in one of the |
3020 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't |
3021 | * treat the array pointers as a reference to the object. |
3022 | */ |
3023 | if (objp) |
3024 | kmemleak_erase(&ac->entry[ac->avail]); |
3025 | return objp; |
3026 | } |
3027 | |
3028 | #ifdef CONFIG_NUMA |
3029 | /* |
3030 | * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. |
3031 | * |
3032 | * If we are in_interrupt, then process context, including cpusets and |
3033 | * mempolicy, may not apply and should not be used for allocation policy. |
3034 | */ |
3035 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) |
3036 | { |
3037 | int nid_alloc, nid_here; |
3038 | |
3039 | if (in_interrupt() || (flags & __GFP_THISNODE)) |
3040 | return NULL; |
3041 | nid_alloc = nid_here = numa_mem_id(); |
3042 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) |
3043 | nid_alloc = cpuset_slab_spread_node(); |
3044 | else if (current->mempolicy) |
3045 | nid_alloc = slab_node(); |
3046 | if (nid_alloc != nid_here) |
3047 | return ____cache_alloc_node(cachep, flags, nid_alloc); |
3048 | return NULL; |
3049 | } |
3050 | |
3051 | /* |
3052 | * Fallback function if there was no memory available and no objects on a |
3053 | * certain node and fall back is permitted. First we scan all the |
3054 | * available node for available objects. If that fails then we |
3055 | * perform an allocation without specifying a node. This allows the page |
3056 | * allocator to do its reclaim / fallback magic. We then insert the |
3057 | * slab into the proper nodelist and then allocate from it. |
3058 | */ |
3059 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) |
3060 | { |
3061 | struct zonelist *zonelist; |
3062 | gfp_t local_flags; |
3063 | struct zoneref *z; |
3064 | struct zone *zone; |
3065 | enum zone_type high_zoneidx = gfp_zone(flags); |
3066 | void *obj = NULL; |
3067 | int nid; |
3068 | unsigned int cpuset_mems_cookie; |
3069 | |
3070 | if (flags & __GFP_THISNODE) |
3071 | return NULL; |
3072 | |
3073 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
3074 | |
3075 | retry_cpuset: |
3076 | cpuset_mems_cookie = get_mems_allowed(); |
3077 | zonelist = node_zonelist(slab_node(), flags); |
3078 | |
3079 | retry: |
3080 | /* |
3081 | * Look through allowed nodes for objects available |
3082 | * from existing per node queues. |
3083 | */ |
3084 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
3085 | nid = zone_to_nid(zone); |
3086 | |
3087 | if (cpuset_zone_allowed_hardwall(zone, flags) && |
3088 | cache->node[nid] && |
3089 | cache->node[nid]->free_objects) { |
3090 | obj = ____cache_alloc_node(cache, |
3091 | flags | GFP_THISNODE, nid); |
3092 | if (obj) |
3093 | break; |
3094 | } |
3095 | } |
3096 | |
3097 | if (!obj) { |
3098 | /* |
3099 | * This allocation will be performed within the constraints |
3100 | * of the current cpuset / memory policy requirements. |
3101 | * We may trigger various forms of reclaim on the allowed |
3102 | * set and go into memory reserves if necessary. |
3103 | */ |
3104 | struct page *page; |
3105 | |
3106 | if (local_flags & __GFP_WAIT) |
3107 | local_irq_enable(); |
3108 | kmem_flagcheck(cache, flags); |
3109 | page = kmem_getpages(cache, local_flags, numa_mem_id()); |
3110 | if (local_flags & __GFP_WAIT) |
3111 | local_irq_disable(); |
3112 | if (page) { |
3113 | /* |
3114 | * Insert into the appropriate per node queues |
3115 | */ |
3116 | nid = page_to_nid(page); |
3117 | if (cache_grow(cache, flags, nid, page)) { |
3118 | obj = ____cache_alloc_node(cache, |
3119 | flags | GFP_THISNODE, nid); |
3120 | if (!obj) |
3121 | /* |
3122 | * Another processor may allocate the |
3123 | * objects in the slab since we are |
3124 | * not holding any locks. |
3125 | */ |
3126 | goto retry; |
3127 | } else { |
3128 | /* cache_grow already freed obj */ |
3129 | obj = NULL; |
3130 | } |
3131 | } |
3132 | } |
3133 | |
3134 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !obj)) |
3135 | goto retry_cpuset; |
3136 | return obj; |
3137 | } |
3138 | |
3139 | /* |
3140 | * A interface to enable slab creation on nodeid |
3141 | */ |
3142 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, |
3143 | int nodeid) |
3144 | { |
3145 | struct list_head *entry; |
3146 | struct page *page; |
3147 | struct kmem_cache_node *n; |
3148 | void *obj; |
3149 | int x; |
3150 | |
3151 | VM_BUG_ON(nodeid > num_online_nodes()); |
3152 | n = cachep->node[nodeid]; |
3153 | BUG_ON(!n); |
3154 | |
3155 | retry: |
3156 | check_irq_off(); |
3157 | spin_lock(&n->list_lock); |
3158 | entry = n->slabs_partial.next; |
3159 | if (entry == &n->slabs_partial) { |
3160 | n->free_touched = 1; |
3161 | entry = n->slabs_free.next; |
3162 | if (entry == &n->slabs_free) |
3163 | goto must_grow; |
3164 | } |
3165 | |
3166 | page = list_entry(entry, struct page, lru); |
3167 | check_spinlock_acquired_node(cachep, nodeid); |
3168 | |
3169 | STATS_INC_NODEALLOCS(cachep); |
3170 | STATS_INC_ACTIVE(cachep); |
3171 | STATS_SET_HIGH(cachep); |
3172 | |
3173 | BUG_ON(page->active == cachep->num); |
3174 | |
3175 | obj = slab_get_obj(cachep, page, nodeid); |
3176 | n->free_objects--; |
3177 | /* move slabp to correct slabp list: */ |
3178 | list_del(&page->lru); |
3179 | |
3180 | if (page->active == cachep->num) |
3181 | list_add(&page->lru, &n->slabs_full); |
3182 | else |
3183 | list_add(&page->lru, &n->slabs_partial); |
3184 | |
3185 | spin_unlock(&n->list_lock); |
3186 | goto done; |
3187 | |
3188 | must_grow: |
3189 | spin_unlock(&n->list_lock); |
3190 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); |
3191 | if (x) |
3192 | goto retry; |
3193 | |
3194 | return fallback_alloc(cachep, flags); |
3195 | |
3196 | done: |
3197 | return obj; |
3198 | } |
3199 | |
3200 | static __always_inline void * |
3201 | slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, |
3202 | unsigned long caller) |
3203 | { |
3204 | unsigned long save_flags; |
3205 | void *ptr; |
3206 | int slab_node = numa_mem_id(); |
3207 | |
3208 | flags &= gfp_allowed_mask; |
3209 | |
3210 | lockdep_trace_alloc(flags); |
3211 | |
3212 | if (slab_should_failslab(cachep, flags)) |
3213 | return NULL; |
3214 | |
3215 | cachep = memcg_kmem_get_cache(cachep, flags); |
3216 | |
3217 | cache_alloc_debugcheck_before(cachep, flags); |
3218 | local_irq_save(save_flags); |
3219 | |
3220 | if (nodeid == NUMA_NO_NODE) |
3221 | nodeid = slab_node; |
3222 | |
3223 | if (unlikely(!cachep->node[nodeid])) { |
3224 | /* Node not bootstrapped yet */ |
3225 | ptr = fallback_alloc(cachep, flags); |
3226 | goto out; |
3227 | } |
3228 | |
3229 | if (nodeid == slab_node) { |
3230 | /* |
3231 | * Use the locally cached objects if possible. |
3232 | * However ____cache_alloc does not allow fallback |
3233 | * to other nodes. It may fail while we still have |
3234 | * objects on other nodes available. |
3235 | */ |
3236 | ptr = ____cache_alloc(cachep, flags); |
3237 | if (ptr) |
3238 | goto out; |
3239 | } |
3240 | /* ___cache_alloc_node can fall back to other nodes */ |
3241 | ptr = ____cache_alloc_node(cachep, flags, nodeid); |
3242 | out: |
3243 | local_irq_restore(save_flags); |
3244 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
3245 | kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, |
3246 | flags); |
3247 | |
3248 | if (likely(ptr)) |
3249 | kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); |
3250 | |
3251 | if (unlikely((flags & __GFP_ZERO) && ptr)) |
3252 | memset(ptr, 0, cachep->object_size); |
3253 | |
3254 | return ptr; |
3255 | } |
3256 | |
3257 | static __always_inline void * |
3258 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) |
3259 | { |
3260 | void *objp; |
3261 | |
3262 | if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { |
3263 | objp = alternate_node_alloc(cache, flags); |
3264 | if (objp) |
3265 | goto out; |
3266 | } |
3267 | objp = ____cache_alloc(cache, flags); |
3268 | |
3269 | /* |
3270 | * We may just have run out of memory on the local node. |
3271 | * ____cache_alloc_node() knows how to locate memory on other nodes |
3272 | */ |
3273 | if (!objp) |
3274 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); |
3275 | |
3276 | out: |
3277 | return objp; |
3278 | } |
3279 | #else |
3280 | |
3281 | static __always_inline void * |
3282 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3283 | { |
3284 | return ____cache_alloc(cachep, flags); |
3285 | } |
3286 | |
3287 | #endif /* CONFIG_NUMA */ |
3288 | |
3289 | static __always_inline void * |
3290 | slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) |
3291 | { |
3292 | unsigned long save_flags; |
3293 | void *objp; |
3294 | |
3295 | flags &= gfp_allowed_mask; |
3296 | |
3297 | lockdep_trace_alloc(flags); |
3298 | |
3299 | if (slab_should_failslab(cachep, flags)) |
3300 | return NULL; |
3301 | |
3302 | cachep = memcg_kmem_get_cache(cachep, flags); |
3303 | |
3304 | cache_alloc_debugcheck_before(cachep, flags); |
3305 | local_irq_save(save_flags); |
3306 | objp = __do_cache_alloc(cachep, flags); |
3307 | local_irq_restore(save_flags); |
3308 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
3309 | kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, |
3310 | flags); |
3311 | prefetchw(objp); |
3312 | |
3313 | if (likely(objp)) |
3314 | kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); |
3315 | |
3316 | if (unlikely((flags & __GFP_ZERO) && objp)) |
3317 | memset(objp, 0, cachep->object_size); |
3318 | |
3319 | return objp; |
3320 | } |
3321 | |
3322 | /* |
3323 | * Caller needs to acquire correct kmem_list's list_lock |
3324 | */ |
3325 | static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, |
3326 | int node) |
3327 | { |
3328 | int i; |
3329 | struct kmem_cache_node *n; |
3330 | |
3331 | for (i = 0; i < nr_objects; i++) { |
3332 | void *objp; |
3333 | struct page *page; |
3334 | |
3335 | clear_obj_pfmemalloc(&objpp[i]); |
3336 | objp = objpp[i]; |
3337 | |
3338 | page = virt_to_head_page(objp); |
3339 | n = cachep->node[node]; |
3340 | list_del(&page->lru); |
3341 | check_spinlock_acquired_node(cachep, node); |
3342 | slab_put_obj(cachep, page, objp, node); |
3343 | STATS_DEC_ACTIVE(cachep); |
3344 | n->free_objects++; |
3345 | |
3346 | /* fixup slab chains */ |
3347 | if (page->active == 0) { |
3348 | if (n->free_objects > n->free_limit) { |
3349 | n->free_objects -= cachep->num; |
3350 | /* No need to drop any previously held |
3351 | * lock here, even if we have a off-slab slab |
3352 | * descriptor it is guaranteed to come from |
3353 | * a different cache, refer to comments before |
3354 | * alloc_slabmgmt. |
3355 | */ |
3356 | slab_destroy(cachep, page); |
3357 | } else { |
3358 | list_add(&page->lru, &n->slabs_free); |
3359 | } |
3360 | } else { |
3361 | /* Unconditionally move a slab to the end of the |
3362 | * partial list on free - maximum time for the |
3363 | * other objects to be freed, too. |
3364 | */ |
3365 | list_add_tail(&page->lru, &n->slabs_partial); |
3366 | } |
3367 | } |
3368 | } |
3369 | |
3370 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) |
3371 | { |
3372 | int batchcount; |
3373 | struct kmem_cache_node *n; |
3374 | int node = numa_mem_id(); |
3375 | |
3376 | batchcount = ac->batchcount; |
3377 | #if DEBUG |
3378 | BUG_ON(!batchcount || batchcount > ac->avail); |
3379 | #endif |
3380 | check_irq_off(); |
3381 | n = cachep->node[node]; |
3382 | spin_lock(&n->list_lock); |
3383 | if (n->shared) { |
3384 | struct array_cache *shared_array = n->shared; |
3385 | int max = shared_array->limit - shared_array->avail; |
3386 | if (max) { |
3387 | if (batchcount > max) |
3388 | batchcount = max; |
3389 | memcpy(&(shared_array->entry[shared_array->avail]), |
3390 | ac->entry, sizeof(void *) * batchcount); |
3391 | shared_array->avail += batchcount; |
3392 | goto free_done; |
3393 | } |
3394 | } |
3395 | |
3396 | free_block(cachep, ac->entry, batchcount, node); |
3397 | free_done: |
3398 | #if STATS |
3399 | { |
3400 | int i = 0; |
3401 | struct list_head *p; |
3402 | |
3403 | p = n->slabs_free.next; |
3404 | while (p != &(n->slabs_free)) { |
3405 | struct page *page; |
3406 | |
3407 | page = list_entry(p, struct page, lru); |
3408 | BUG_ON(page->active); |
3409 | |
3410 | i++; |
3411 | p = p->next; |
3412 | } |
3413 | STATS_SET_FREEABLE(cachep, i); |
3414 | } |
3415 | #endif |
3416 | spin_unlock(&n->list_lock); |
3417 | ac->avail -= batchcount; |
3418 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); |
3419 | } |
3420 | |
3421 | /* |
3422 | * Release an obj back to its cache. If the obj has a constructed state, it must |
3423 | * be in this state _before_ it is released. Called with disabled ints. |
3424 | */ |
3425 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, |
3426 | unsigned long caller) |
3427 | { |
3428 | struct array_cache *ac = cpu_cache_get(cachep); |
3429 | |
3430 | check_irq_off(); |
3431 | kmemleak_free_recursive(objp, cachep->flags); |
3432 | objp = cache_free_debugcheck(cachep, objp, caller); |
3433 | |
3434 | kmemcheck_slab_free(cachep, objp, cachep->object_size); |
3435 | |
3436 | /* |
3437 | * Skip calling cache_free_alien() when the platform is not numa. |
3438 | * This will avoid cache misses that happen while accessing slabp (which |
3439 | * is per page memory reference) to get nodeid. Instead use a global |
3440 | * variable to skip the call, which is mostly likely to be present in |
3441 | * the cache. |
3442 | */ |
3443 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) |
3444 | return; |
3445 | |
3446 | if (likely(ac->avail < ac->limit)) { |
3447 | STATS_INC_FREEHIT(cachep); |
3448 | } else { |
3449 | STATS_INC_FREEMISS(cachep); |
3450 | cache_flusharray(cachep, ac); |
3451 | } |
3452 | |
3453 | ac_put_obj(cachep, ac, objp); |
3454 | } |
3455 | |
3456 | /** |
3457 | * kmem_cache_alloc - Allocate an object |
3458 | * @cachep: The cache to allocate from. |
3459 | * @flags: See kmalloc(). |
3460 | * |
3461 | * Allocate an object from this cache. The flags are only relevant |
3462 | * if the cache has no available objects. |
3463 | */ |
3464 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3465 | { |
3466 | void *ret = slab_alloc(cachep, flags, _RET_IP_); |
3467 | |
3468 | trace_kmem_cache_alloc(_RET_IP_, ret, |
3469 | cachep->object_size, cachep->size, flags); |
3470 | |
3471 | return ret; |
3472 | } |
3473 | EXPORT_SYMBOL(kmem_cache_alloc); |
3474 | |
3475 | #ifdef CONFIG_TRACING |
3476 | void * |
3477 | kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) |
3478 | { |
3479 | void *ret; |
3480 | |
3481 | ret = slab_alloc(cachep, flags, _RET_IP_); |
3482 | |
3483 | trace_kmalloc(_RET_IP_, ret, |
3484 | size, cachep->size, flags); |
3485 | return ret; |
3486 | } |
3487 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
3488 | #endif |
3489 | |
3490 | #ifdef CONFIG_NUMA |
3491 | /** |
3492 | * kmem_cache_alloc_node - Allocate an object on the specified node |
3493 | * @cachep: The cache to allocate from. |
3494 | * @flags: See kmalloc(). |
3495 | * @nodeid: node number of the target node. |
3496 | * |
3497 | * Identical to kmem_cache_alloc but it will allocate memory on the given |
3498 | * node, which can improve the performance for cpu bound structures. |
3499 | * |
3500 | * Fallback to other node is possible if __GFP_THISNODE is not set. |
3501 | */ |
3502 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
3503 | { |
3504 | void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3505 | |
3506 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
3507 | cachep->object_size, cachep->size, |
3508 | flags, nodeid); |
3509 | |
3510 | return ret; |
3511 | } |
3512 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
3513 | |
3514 | #ifdef CONFIG_TRACING |
3515 | void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, |
3516 | gfp_t flags, |
3517 | int nodeid, |
3518 | size_t size) |
3519 | { |
3520 | void *ret; |
3521 | |
3522 | ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3523 | |
3524 | trace_kmalloc_node(_RET_IP_, ret, |
3525 | size, cachep->size, |
3526 | flags, nodeid); |
3527 | return ret; |
3528 | } |
3529 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
3530 | #endif |
3531 | |
3532 | static __always_inline void * |
3533 | __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) |
3534 | { |
3535 | struct kmem_cache *cachep; |
3536 | |
3537 | cachep = kmalloc_slab(size, flags); |
3538 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3539 | return cachep; |
3540 | return kmem_cache_alloc_node_trace(cachep, flags, node, size); |
3541 | } |
3542 | |
3543 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3544 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3545 | { |
3546 | return __do_kmalloc_node(size, flags, node, _RET_IP_); |
3547 | } |
3548 | EXPORT_SYMBOL(__kmalloc_node); |
3549 | |
3550 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, |
3551 | int node, unsigned long caller) |
3552 | { |
3553 | return __do_kmalloc_node(size, flags, node, caller); |
3554 | } |
3555 | EXPORT_SYMBOL(__kmalloc_node_track_caller); |
3556 | #else |
3557 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3558 | { |
3559 | return __do_kmalloc_node(size, flags, node, 0); |
3560 | } |
3561 | EXPORT_SYMBOL(__kmalloc_node); |
3562 | #endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ |
3563 | #endif /* CONFIG_NUMA */ |
3564 | |
3565 | /** |
3566 | * __do_kmalloc - allocate memory |
3567 | * @size: how many bytes of memory are required. |
3568 | * @flags: the type of memory to allocate (see kmalloc). |
3569 | * @caller: function caller for debug tracking of the caller |
3570 | */ |
3571 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, |
3572 | unsigned long caller) |
3573 | { |
3574 | struct kmem_cache *cachep; |
3575 | void *ret; |
3576 | |
3577 | /* If you want to save a few bytes .text space: replace |
3578 | * __ with kmem_. |
3579 | * Then kmalloc uses the uninlined functions instead of the inline |
3580 | * functions. |
3581 | */ |
3582 | cachep = kmalloc_slab(size, flags); |
3583 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3584 | return cachep; |
3585 | ret = slab_alloc(cachep, flags, caller); |
3586 | |
3587 | trace_kmalloc(caller, ret, |
3588 | size, cachep->size, flags); |
3589 | |
3590 | return ret; |
3591 | } |
3592 | |
3593 | |
3594 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3595 | void *__kmalloc(size_t size, gfp_t flags) |
3596 | { |
3597 | return __do_kmalloc(size, flags, _RET_IP_); |
3598 | } |
3599 | EXPORT_SYMBOL(__kmalloc); |
3600 | |
3601 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) |
3602 | { |
3603 | return __do_kmalloc(size, flags, caller); |
3604 | } |
3605 | EXPORT_SYMBOL(__kmalloc_track_caller); |
3606 | |
3607 | #else |
3608 | void *__kmalloc(size_t size, gfp_t flags) |
3609 | { |
3610 | return __do_kmalloc(size, flags, 0); |
3611 | } |
3612 | EXPORT_SYMBOL(__kmalloc); |
3613 | #endif |
3614 | |
3615 | /** |
3616 | * kmem_cache_free - Deallocate an object |
3617 | * @cachep: The cache the allocation was from. |
3618 | * @objp: The previously allocated object. |
3619 | * |
3620 | * Free an object which was previously allocated from this |
3621 | * cache. |
3622 | */ |
3623 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) |
3624 | { |
3625 | unsigned long flags; |
3626 | cachep = cache_from_obj(cachep, objp); |
3627 | if (!cachep) |
3628 | return; |
3629 | |
3630 | local_irq_save(flags); |
3631 | debug_check_no_locks_freed(objp, cachep->object_size); |
3632 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) |
3633 | debug_check_no_obj_freed(objp, cachep->object_size); |
3634 | __cache_free(cachep, objp, _RET_IP_); |
3635 | local_irq_restore(flags); |
3636 | |
3637 | trace_kmem_cache_free(_RET_IP_, objp); |
3638 | } |
3639 | EXPORT_SYMBOL(kmem_cache_free); |
3640 | |
3641 | /** |
3642 | * kfree - free previously allocated memory |
3643 | * @objp: pointer returned by kmalloc. |
3644 | * |
3645 | * If @objp is NULL, no operation is performed. |
3646 | * |
3647 | * Don't free memory not originally allocated by kmalloc() |
3648 | * or you will run into trouble. |
3649 | */ |
3650 | void kfree(const void *objp) |
3651 | { |
3652 | struct kmem_cache *c; |
3653 | unsigned long flags; |
3654 | |
3655 | trace_kfree(_RET_IP_, objp); |
3656 | |
3657 | if (unlikely(ZERO_OR_NULL_PTR(objp))) |
3658 | return; |
3659 | local_irq_save(flags); |
3660 | kfree_debugcheck(objp); |
3661 | c = virt_to_cache(objp); |
3662 | debug_check_no_locks_freed(objp, c->object_size); |
3663 | |
3664 | debug_check_no_obj_freed(objp, c->object_size); |
3665 | __cache_free(c, (void *)objp, _RET_IP_); |
3666 | local_irq_restore(flags); |
3667 | } |
3668 | EXPORT_SYMBOL(kfree); |
3669 | |
3670 | /* |
3671 | * This initializes kmem_cache_node or resizes various caches for all nodes. |
3672 | */ |
3673 | static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) |
3674 | { |
3675 | int node; |
3676 | struct kmem_cache_node *n; |
3677 | struct array_cache *new_shared; |
3678 | struct array_cache **new_alien = NULL; |
3679 | |
3680 | for_each_online_node(node) { |
3681 | |
3682 | if (use_alien_caches) { |
3683 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); |
3684 | if (!new_alien) |
3685 | goto fail; |
3686 | } |
3687 | |
3688 | new_shared = NULL; |
3689 | if (cachep->shared) { |
3690 | new_shared = alloc_arraycache(node, |
3691 | cachep->shared*cachep->batchcount, |
3692 | 0xbaadf00d, gfp); |
3693 | if (!new_shared) { |
3694 | free_alien_cache(new_alien); |
3695 | goto fail; |
3696 | } |
3697 | } |
3698 | |
3699 | n = cachep->node[node]; |
3700 | if (n) { |
3701 | struct array_cache *shared = n->shared; |
3702 | |
3703 | spin_lock_irq(&n->list_lock); |
3704 | |
3705 | if (shared) |
3706 | free_block(cachep, shared->entry, |
3707 | shared->avail, node); |
3708 | |
3709 | n->shared = new_shared; |
3710 | if (!n->alien) { |
3711 | n->alien = new_alien; |
3712 | new_alien = NULL; |
3713 | } |
3714 | n->free_limit = (1 + nr_cpus_node(node)) * |
3715 | cachep->batchcount + cachep->num; |
3716 | spin_unlock_irq(&n->list_lock); |
3717 | kfree(shared); |
3718 | free_alien_cache(new_alien); |
3719 | continue; |
3720 | } |
3721 | n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); |
3722 | if (!n) { |
3723 | free_alien_cache(new_alien); |
3724 | kfree(new_shared); |
3725 | goto fail; |
3726 | } |
3727 | |
3728 | kmem_cache_node_init(n); |
3729 | n->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
3730 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
3731 | n->shared = new_shared; |
3732 | n->alien = new_alien; |
3733 | n->free_limit = (1 + nr_cpus_node(node)) * |
3734 | cachep->batchcount + cachep->num; |
3735 | cachep->node[node] = n; |
3736 | } |
3737 | return 0; |
3738 | |
3739 | fail: |
3740 | if (!cachep->list.next) { |
3741 | /* Cache is not active yet. Roll back what we did */ |
3742 | node--; |
3743 | while (node >= 0) { |
3744 | if (cachep->node[node]) { |
3745 | n = cachep->node[node]; |
3746 | |
3747 | kfree(n->shared); |
3748 | free_alien_cache(n->alien); |
3749 | kfree(n); |
3750 | cachep->node[node] = NULL; |
3751 | } |
3752 | node--; |
3753 | } |
3754 | } |
3755 | return -ENOMEM; |
3756 | } |
3757 | |
3758 | struct ccupdate_struct { |
3759 | struct kmem_cache *cachep; |
3760 | struct array_cache *new[0]; |
3761 | }; |
3762 | |
3763 | static void do_ccupdate_local(void *info) |
3764 | { |
3765 | struct ccupdate_struct *new = info; |
3766 | struct array_cache *old; |
3767 | |
3768 | check_irq_off(); |
3769 | old = cpu_cache_get(new->cachep); |
3770 | |
3771 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; |
3772 | new->new[smp_processor_id()] = old; |
3773 | } |
3774 | |
3775 | /* Always called with the slab_mutex held */ |
3776 | static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3777 | int batchcount, int shared, gfp_t gfp) |
3778 | { |
3779 | struct ccupdate_struct *new; |
3780 | int i; |
3781 | |
3782 | new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *), |
3783 | gfp); |
3784 | if (!new) |
3785 | return -ENOMEM; |
3786 | |
3787 | for_each_online_cpu(i) { |
3788 | new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, |
3789 | batchcount, gfp); |
3790 | if (!new->new[i]) { |
3791 | for (i--; i >= 0; i--) |
3792 | kfree(new->new[i]); |
3793 | kfree(new); |
3794 | return -ENOMEM; |
3795 | } |
3796 | } |
3797 | new->cachep = cachep; |
3798 | |
3799 | on_each_cpu(do_ccupdate_local, (void *)new, 1); |
3800 | |
3801 | check_irq_on(); |
3802 | cachep->batchcount = batchcount; |
3803 | cachep->limit = limit; |
3804 | cachep->shared = shared; |
3805 | |
3806 | for_each_online_cpu(i) { |
3807 | struct array_cache *ccold = new->new[i]; |
3808 | if (!ccold) |
3809 | continue; |
3810 | spin_lock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); |
3811 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); |
3812 | spin_unlock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); |
3813 | kfree(ccold); |
3814 | } |
3815 | kfree(new); |
3816 | return alloc_kmemlist(cachep, gfp); |
3817 | } |
3818 | |
3819 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3820 | int batchcount, int shared, gfp_t gfp) |
3821 | { |
3822 | int ret; |
3823 | struct kmem_cache *c = NULL; |
3824 | int i = 0; |
3825 | |
3826 | ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
3827 | |
3828 | if (slab_state < FULL) |
3829 | return ret; |
3830 | |
3831 | if ((ret < 0) || !is_root_cache(cachep)) |
3832 | return ret; |
3833 | |
3834 | VM_BUG_ON(!mutex_is_locked(&slab_mutex)); |
3835 | for_each_memcg_cache_index(i) { |
3836 | c = cache_from_memcg_idx(cachep, i); |
3837 | if (c) |
3838 | /* return value determined by the parent cache only */ |
3839 | __do_tune_cpucache(c, limit, batchcount, shared, gfp); |
3840 | } |
3841 | |
3842 | return ret; |
3843 | } |
3844 | |
3845 | /* Called with slab_mutex held always */ |
3846 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) |
3847 | { |
3848 | int err; |
3849 | int limit = 0; |
3850 | int shared = 0; |
3851 | int batchcount = 0; |
3852 | |
3853 | if (!is_root_cache(cachep)) { |
3854 | struct kmem_cache *root = memcg_root_cache(cachep); |
3855 | limit = root->limit; |
3856 | shared = root->shared; |
3857 | batchcount = root->batchcount; |
3858 | } |
3859 | |
3860 | if (limit && shared && batchcount) |
3861 | goto skip_setup; |
3862 | /* |
3863 | * The head array serves three purposes: |
3864 | * - create a LIFO ordering, i.e. return objects that are cache-warm |
3865 | * - reduce the number of spinlock operations. |
3866 | * - reduce the number of linked list operations on the slab and |
3867 | * bufctl chains: array operations are cheaper. |
3868 | * The numbers are guessed, we should auto-tune as described by |
3869 | * Bonwick. |
3870 | */ |
3871 | if (cachep->size > 131072) |
3872 | limit = 1; |
3873 | else if (cachep->size > PAGE_SIZE) |
3874 | limit = 8; |
3875 | else if (cachep->size > 1024) |
3876 | limit = 24; |
3877 | else if (cachep->size > 256) |
3878 | limit = 54; |
3879 | else |
3880 | limit = 120; |
3881 | |
3882 | /* |
3883 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound |
3884 | * allocation behaviour: Most allocs on one cpu, most free operations |
3885 | * on another cpu. For these cases, an efficient object passing between |
3886 | * cpus is necessary. This is provided by a shared array. The array |
3887 | * replaces Bonwick's magazine layer. |
3888 | * On uniprocessor, it's functionally equivalent (but less efficient) |
3889 | * to a larger limit. Thus disabled by default. |
3890 | */ |
3891 | shared = 0; |
3892 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) |
3893 | shared = 8; |
3894 | |
3895 | #if DEBUG |
3896 | /* |
3897 | * With debugging enabled, large batchcount lead to excessively long |
3898 | * periods with disabled local interrupts. Limit the batchcount |
3899 | */ |
3900 | if (limit > 32) |
3901 | limit = 32; |
3902 | #endif |
3903 | batchcount = (limit + 1) / 2; |
3904 | skip_setup: |
3905 | err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
3906 | if (err) |
3907 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", |
3908 | cachep->name, -err); |
3909 | return err; |
3910 | } |
3911 | |
3912 | /* |
3913 | * Drain an array if it contains any elements taking the node lock only if |
3914 | * necessary. Note that the node listlock also protects the array_cache |
3915 | * if drain_array() is used on the shared array. |
3916 | */ |
3917 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
3918 | struct array_cache *ac, int force, int node) |
3919 | { |
3920 | int tofree; |
3921 | |
3922 | if (!ac || !ac->avail) |
3923 | return; |
3924 | if (ac->touched && !force) { |
3925 | ac->touched = 0; |
3926 | } else { |
3927 | spin_lock_irq(&n->list_lock); |
3928 | if (ac->avail) { |
3929 | tofree = force ? ac->avail : (ac->limit + 4) / 5; |
3930 | if (tofree > ac->avail) |
3931 | tofree = (ac->avail + 1) / 2; |
3932 | free_block(cachep, ac->entry, tofree, node); |
3933 | ac->avail -= tofree; |
3934 | memmove(ac->entry, &(ac->entry[tofree]), |
3935 | sizeof(void *) * ac->avail); |
3936 | } |
3937 | spin_unlock_irq(&n->list_lock); |
3938 | } |
3939 | } |
3940 | |
3941 | /** |
3942 | * cache_reap - Reclaim memory from caches. |
3943 | * @w: work descriptor |
3944 | * |
3945 | * Called from workqueue/eventd every few seconds. |
3946 | * Purpose: |
3947 | * - clear the per-cpu caches for this CPU. |
3948 | * - return freeable pages to the main free memory pool. |
3949 | * |
3950 | * If we cannot acquire the cache chain mutex then just give up - we'll try |
3951 | * again on the next iteration. |
3952 | */ |
3953 | static void cache_reap(struct work_struct *w) |
3954 | { |
3955 | struct kmem_cache *searchp; |
3956 | struct kmem_cache_node *n; |
3957 | int node = numa_mem_id(); |
3958 | struct delayed_work *work = to_delayed_work(w); |
3959 | |
3960 | if (!mutex_trylock(&slab_mutex)) |
3961 | /* Give up. Setup the next iteration. */ |
3962 | goto out; |
3963 | |
3964 | list_for_each_entry(searchp, &slab_caches, list) { |
3965 | check_irq_on(); |
3966 | |
3967 | /* |
3968 | * We only take the node lock if absolutely necessary and we |
3969 | * have established with reasonable certainty that |
3970 | * we can do some work if the lock was obtained. |
3971 | */ |
3972 | n = searchp->node[node]; |
3973 | |
3974 | reap_alien(searchp, n); |
3975 | |
3976 | drain_array(searchp, n, cpu_cache_get(searchp), 0, node); |
3977 | |
3978 | /* |
3979 | * These are racy checks but it does not matter |
3980 | * if we skip one check or scan twice. |
3981 | */ |
3982 | if (time_after(n->next_reap, jiffies)) |
3983 | goto next; |
3984 | |
3985 | n->next_reap = jiffies + REAPTIMEOUT_LIST3; |
3986 | |
3987 | drain_array(searchp, n, n->shared, 0, node); |
3988 | |
3989 | if (n->free_touched) |
3990 | n->free_touched = 0; |
3991 | else { |
3992 | int freed; |
3993 | |
3994 | freed = drain_freelist(searchp, n, (n->free_limit + |
3995 | 5 * searchp->num - 1) / (5 * searchp->num)); |
3996 | STATS_ADD_REAPED(searchp, freed); |
3997 | } |
3998 | next: |
3999 | cond_resched(); |
4000 | } |
4001 | check_irq_on(); |
4002 | mutex_unlock(&slab_mutex); |
4003 | next_reap_node(); |
4004 | out: |
4005 | /* Set up the next iteration */ |
4006 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); |
4007 | } |
4008 | |
4009 | #ifdef CONFIG_SLABINFO |
4010 | void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) |
4011 | { |
4012 | struct page *page; |
4013 | unsigned long active_objs; |
4014 | unsigned long num_objs; |
4015 | unsigned long active_slabs = 0; |
4016 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; |
4017 | const char *name; |
4018 | char *error = NULL; |
4019 | int node; |
4020 | struct kmem_cache_node *n; |
4021 | |
4022 | active_objs = 0; |
4023 | num_slabs = 0; |
4024 | for_each_online_node(node) { |
4025 | n = cachep->node[node]; |
4026 | if (!n) |
4027 | continue; |
4028 | |
4029 | check_irq_on(); |
4030 | spin_lock_irq(&n->list_lock); |
4031 | |
4032 | list_for_each_entry(page, &n->slabs_full, lru) { |
4033 | if (page->active != cachep->num && !error) |
4034 | error = "slabs_full accounting error"; |
4035 | active_objs += cachep->num; |
4036 | active_slabs++; |
4037 | } |
4038 | list_for_each_entry(page, &n->slabs_partial, lru) { |
4039 | if (page->active == cachep->num && !error) |
4040 | error = "slabs_partial accounting error"; |
4041 | if (!page->active && !error) |
4042 | error = "slabs_partial accounting error"; |
4043 | active_objs += page->active; |
4044 | active_slabs++; |
4045 | } |
4046 | list_for_each_entry(page, &n->slabs_free, lru) { |
4047 | if (page->active && !error) |
4048 | error = "slabs_free accounting error"; |
4049 | num_slabs++; |
4050 | } |
4051 | free_objects += n->free_objects; |
4052 | if (n->shared) |
4053 | shared_avail += n->shared->avail; |
4054 | |
4055 | spin_unlock_irq(&n->list_lock); |
4056 | } |
4057 | num_slabs += active_slabs; |
4058 | num_objs = num_slabs * cachep->num; |
4059 | if (num_objs - active_objs != free_objects && !error) |
4060 | error = "free_objects accounting error"; |
4061 | |
4062 | name = cachep->name; |
4063 | if (error) |
4064 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); |
4065 | |
4066 | sinfo->active_objs = active_objs; |
4067 | sinfo->num_objs = num_objs; |
4068 | sinfo->active_slabs = active_slabs; |
4069 | sinfo->num_slabs = num_slabs; |
4070 | sinfo->shared_avail = shared_avail; |
4071 | sinfo->limit = cachep->limit; |
4072 | sinfo->batchcount = cachep->batchcount; |
4073 | sinfo->shared = cachep->shared; |
4074 | sinfo->objects_per_slab = cachep->num; |
4075 | sinfo->cache_order = cachep->gfporder; |
4076 | } |
4077 | |
4078 | void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) |
4079 | { |
4080 | #if STATS |
4081 | { /* node stats */ |
4082 | unsigned long high = cachep->high_mark; |
4083 | unsigned long allocs = cachep->num_allocations; |
4084 | unsigned long grown = cachep->grown; |
4085 | unsigned long reaped = cachep->reaped; |
4086 | unsigned long errors = cachep->errors; |
4087 | unsigned long max_freeable = cachep->max_freeable; |
4088 | unsigned long node_allocs = cachep->node_allocs; |
4089 | unsigned long node_frees = cachep->node_frees; |
4090 | unsigned long overflows = cachep->node_overflow; |
4091 | |
4092 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " |
4093 | "%4lu %4lu %4lu %4lu %4lu", |
4094 | allocs, high, grown, |
4095 | reaped, errors, max_freeable, node_allocs, |
4096 | node_frees, overflows); |
4097 | } |
4098 | /* cpu stats */ |
4099 | { |
4100 | unsigned long allochit = atomic_read(&cachep->allochit); |
4101 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
4102 | unsigned long freehit = atomic_read(&cachep->freehit); |
4103 | unsigned long freemiss = atomic_read(&cachep->freemiss); |
4104 | |
4105 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
4106 | allochit, allocmiss, freehit, freemiss); |
4107 | } |
4108 | #endif |
4109 | } |
4110 | |
4111 | #define MAX_SLABINFO_WRITE 128 |
4112 | /** |
4113 | * slabinfo_write - Tuning for the slab allocator |
4114 | * @file: unused |
4115 | * @buffer: user buffer |
4116 | * @count: data length |
4117 | * @ppos: unused |
4118 | */ |
4119 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
4120 | size_t count, loff_t *ppos) |
4121 | { |
4122 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; |
4123 | int limit, batchcount, shared, res; |
4124 | struct kmem_cache *cachep; |
4125 | |
4126 | if (count > MAX_SLABINFO_WRITE) |
4127 | return -EINVAL; |
4128 | if (copy_from_user(&kbuf, buffer, count)) |
4129 | return -EFAULT; |
4130 | kbuf[MAX_SLABINFO_WRITE] = '\0'; |
4131 | |
4132 | tmp = strchr(kbuf, ' '); |
4133 | if (!tmp) |
4134 | return -EINVAL; |
4135 | *tmp = '\0'; |
4136 | tmp++; |
4137 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
4138 | return -EINVAL; |
4139 | |
4140 | /* Find the cache in the chain of caches. */ |
4141 | mutex_lock(&slab_mutex); |
4142 | res = -EINVAL; |
4143 | list_for_each_entry(cachep, &slab_caches, list) { |
4144 | if (!strcmp(cachep->name, kbuf)) { |
4145 | if (limit < 1 || batchcount < 1 || |
4146 | batchcount > limit || shared < 0) { |
4147 | res = 0; |
4148 | } else { |
4149 | res = do_tune_cpucache(cachep, limit, |
4150 | batchcount, shared, |
4151 | GFP_KERNEL); |
4152 | } |
4153 | break; |
4154 | } |
4155 | } |
4156 | mutex_unlock(&slab_mutex); |
4157 | if (res >= 0) |
4158 | res = count; |
4159 | return res; |
4160 | } |
4161 | |
4162 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4163 | |
4164 | static void *leaks_start(struct seq_file *m, loff_t *pos) |
4165 | { |
4166 | mutex_lock(&slab_mutex); |
4167 | return seq_list_start(&slab_caches, *pos); |
4168 | } |
4169 | |
4170 | static inline int add_caller(unsigned long *n, unsigned long v) |
4171 | { |
4172 | unsigned long *p; |
4173 | int l; |
4174 | if (!v) |
4175 | return 1; |
4176 | l = n[1]; |
4177 | p = n + 2; |
4178 | while (l) { |
4179 | int i = l/2; |
4180 | unsigned long *q = p + 2 * i; |
4181 | if (*q == v) { |
4182 | q[1]++; |
4183 | return 1; |
4184 | } |
4185 | if (*q > v) { |
4186 | l = i; |
4187 | } else { |
4188 | p = q + 2; |
4189 | l -= i + 1; |
4190 | } |
4191 | } |
4192 | if (++n[1] == n[0]) |
4193 | return 0; |
4194 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); |
4195 | p[0] = v; |
4196 | p[1] = 1; |
4197 | return 1; |
4198 | } |
4199 | |
4200 | static void handle_slab(unsigned long *n, struct kmem_cache *c, |
4201 | struct page *page) |
4202 | { |
4203 | void *p; |
4204 | int i, j; |
4205 | |
4206 | if (n[0] == n[1]) |
4207 | return; |
4208 | for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) { |
4209 | bool active = true; |
4210 | |
4211 | for (j = page->active; j < c->num; j++) { |
4212 | /* Skip freed item */ |
4213 | if (slab_freelist(page)[j] == i) { |
4214 | active = false; |
4215 | break; |
4216 | } |
4217 | } |
4218 | if (!active) |
4219 | continue; |
4220 | |
4221 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) |
4222 | return; |
4223 | } |
4224 | } |
4225 | |
4226 | static void show_symbol(struct seq_file *m, unsigned long address) |
4227 | { |
4228 | #ifdef CONFIG_KALLSYMS |
4229 | unsigned long offset, size; |
4230 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; |
4231 | |
4232 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { |
4233 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); |
4234 | if (modname[0]) |
4235 | seq_printf(m, " [%s]", modname); |
4236 | return; |
4237 | } |
4238 | #endif |
4239 | seq_printf(m, "%p", (void *)address); |
4240 | } |
4241 | |
4242 | static int leaks_show(struct seq_file *m, void *p) |
4243 | { |
4244 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); |
4245 | struct page *page; |
4246 | struct kmem_cache_node *n; |
4247 | const char *name; |
4248 | unsigned long *x = m->private; |
4249 | int node; |
4250 | int i; |
4251 | |
4252 | if (!(cachep->flags & SLAB_STORE_USER)) |
4253 | return 0; |
4254 | if (!(cachep->flags & SLAB_RED_ZONE)) |
4255 | return 0; |
4256 | |
4257 | /* OK, we can do it */ |
4258 | |
4259 | x[1] = 0; |
4260 | |
4261 | for_each_online_node(node) { |
4262 | n = cachep->node[node]; |
4263 | if (!n) |
4264 | continue; |
4265 | |
4266 | check_irq_on(); |
4267 | spin_lock_irq(&n->list_lock); |
4268 | |
4269 | list_for_each_entry(page, &n->slabs_full, lru) |
4270 | handle_slab(x, cachep, page); |
4271 | list_for_each_entry(page, &n->slabs_partial, lru) |
4272 | handle_slab(x, cachep, page); |
4273 | spin_unlock_irq(&n->list_lock); |
4274 | } |
4275 | name = cachep->name; |
4276 | if (x[0] == x[1]) { |
4277 | /* Increase the buffer size */ |
4278 | mutex_unlock(&slab_mutex); |
4279 | m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL); |
4280 | if (!m->private) { |
4281 | /* Too bad, we are really out */ |
4282 | m->private = x; |
4283 | mutex_lock(&slab_mutex); |
4284 | return -ENOMEM; |
4285 | } |
4286 | *(unsigned long *)m->private = x[0] * 2; |
4287 | kfree(x); |
4288 | mutex_lock(&slab_mutex); |
4289 | /* Now make sure this entry will be retried */ |
4290 | m->count = m->size; |
4291 | return 0; |
4292 | } |
4293 | for (i = 0; i < x[1]; i++) { |
4294 | seq_printf(m, "%s: %lu ", name, x[2*i+3]); |
4295 | show_symbol(m, x[2*i+2]); |
4296 | seq_putc(m, '\n'); |
4297 | } |
4298 | |
4299 | return 0; |
4300 | } |
4301 | |
4302 | static const struct seq_operations slabstats_op = { |
4303 | .start = leaks_start, |
4304 | .next = slab_next, |
4305 | .stop = slab_stop, |
4306 | .show = leaks_show, |
4307 | }; |
4308 | |
4309 | static int slabstats_open(struct inode *inode, struct file *file) |
4310 | { |
4311 | unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); |
4312 | int ret = -ENOMEM; |
4313 | if (n) { |
4314 | ret = seq_open(file, &slabstats_op); |
4315 | if (!ret) { |
4316 | struct seq_file *m = file->private_data; |
4317 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); |
4318 | m->private = n; |
4319 | n = NULL; |
4320 | } |
4321 | kfree(n); |
4322 | } |
4323 | return ret; |
4324 | } |
4325 | |
4326 | static const struct file_operations proc_slabstats_operations = { |
4327 | .open = slabstats_open, |
4328 | .read = seq_read, |
4329 | .llseek = seq_lseek, |
4330 | .release = seq_release_private, |
4331 | }; |
4332 | #endif |
4333 | |
4334 | static int __init slab_proc_init(void) |
4335 | { |
4336 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4337 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); |
4338 | #endif |
4339 | return 0; |
4340 | } |
4341 | module_init(slab_proc_init); |
4342 | #endif |
4343 | |
4344 | /** |
4345 | * ksize - get the actual amount of memory allocated for a given object |
4346 | * @objp: Pointer to the object |
4347 | * |
4348 | * kmalloc may internally round up allocations and return more memory |
4349 | * than requested. ksize() can be used to determine the actual amount of |
4350 | * memory allocated. The caller may use this additional memory, even though |
4351 | * a smaller amount of memory was initially specified with the kmalloc call. |
4352 | * The caller must guarantee that objp points to a valid object previously |
4353 | * allocated with either kmalloc() or kmem_cache_alloc(). The object |
4354 | * must not be freed during the duration of the call. |
4355 | */ |
4356 | size_t ksize(const void *objp) |
4357 | { |
4358 | BUG_ON(!objp); |
4359 | if (unlikely(objp == ZERO_SIZE_PTR)) |
4360 | return 0; |
4361 | |
4362 | return virt_to_cache(objp)->object_size; |
4363 | } |
4364 | EXPORT_SYMBOL(ksize); |
4365 |
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