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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 | #define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \ |
161 | <= SLAB_OBJ_MIN_SIZE) ? 1 : 0) |
162 | |
163 | #if FREELIST_BYTE_INDEX |
164 | typedef unsigned char freelist_idx_t; |
165 | #else |
166 | typedef unsigned short freelist_idx_t; |
167 | #endif |
168 | |
169 | #define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1) |
170 | |
171 | /* |
172 | * true if a page was allocated from pfmemalloc reserves for network-based |
173 | * swap |
174 | */ |
175 | static bool pfmemalloc_active __read_mostly; |
176 | |
177 | /* |
178 | * struct array_cache |
179 | * |
180 | * Purpose: |
181 | * - LIFO ordering, to hand out cache-warm objects from _alloc |
182 | * - reduce the number of linked list operations |
183 | * - reduce spinlock operations |
184 | * |
185 | * The limit is stored in the per-cpu structure to reduce the data cache |
186 | * footprint. |
187 | * |
188 | */ |
189 | struct array_cache { |
190 | unsigned int avail; |
191 | unsigned int limit; |
192 | unsigned int batchcount; |
193 | unsigned int touched; |
194 | void *entry[]; /* |
195 | * Must have this definition in here for the proper |
196 | * alignment of array_cache. Also simplifies accessing |
197 | * the entries. |
198 | * |
199 | * Entries should not be directly dereferenced as |
200 | * entries belonging to slabs marked pfmemalloc will |
201 | * have the lower bits set SLAB_OBJ_PFMEMALLOC |
202 | */ |
203 | }; |
204 | |
205 | struct alien_cache { |
206 | spinlock_t lock; |
207 | struct array_cache ac; |
208 | }; |
209 | |
210 | #define SLAB_OBJ_PFMEMALLOC 1 |
211 | static inline bool is_obj_pfmemalloc(void *objp) |
212 | { |
213 | return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; |
214 | } |
215 | |
216 | static inline void set_obj_pfmemalloc(void **objp) |
217 | { |
218 | *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); |
219 | return; |
220 | } |
221 | |
222 | static inline void clear_obj_pfmemalloc(void **objp) |
223 | { |
224 | *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); |
225 | } |
226 | |
227 | /* |
228 | * bootstrap: The caches do not work without cpuarrays anymore, but the |
229 | * cpuarrays are allocated from the generic caches... |
230 | */ |
231 | #define BOOT_CPUCACHE_ENTRIES 1 |
232 | struct arraycache_init { |
233 | struct array_cache cache; |
234 | void *entries[BOOT_CPUCACHE_ENTRIES]; |
235 | }; |
236 | |
237 | /* |
238 | * Need this for bootstrapping a per node allocator. |
239 | */ |
240 | #define NUM_INIT_LISTS (2 * MAX_NUMNODES) |
241 | static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; |
242 | #define CACHE_CACHE 0 |
243 | #define SIZE_NODE (MAX_NUMNODES) |
244 | |
245 | static int drain_freelist(struct kmem_cache *cache, |
246 | struct kmem_cache_node *n, int tofree); |
247 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, |
248 | int node, struct list_head *list); |
249 | static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list); |
250 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); |
251 | static void cache_reap(struct work_struct *unused); |
252 | |
253 | static int slab_early_init = 1; |
254 | |
255 | #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) |
256 | |
257 | static void kmem_cache_node_init(struct kmem_cache_node *parent) |
258 | { |
259 | INIT_LIST_HEAD(&parent->slabs_full); |
260 | INIT_LIST_HEAD(&parent->slabs_partial); |
261 | INIT_LIST_HEAD(&parent->slabs_free); |
262 | parent->shared = NULL; |
263 | parent->alien = NULL; |
264 | parent->colour_next = 0; |
265 | spin_lock_init(&parent->list_lock); |
266 | parent->free_objects = 0; |
267 | parent->free_touched = 0; |
268 | } |
269 | |
270 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ |
271 | do { \ |
272 | INIT_LIST_HEAD(listp); \ |
273 | list_splice(&get_node(cachep, nodeid)->slab, listp); \ |
274 | } while (0) |
275 | |
276 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ |
277 | do { \ |
278 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ |
279 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ |
280 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ |
281 | } while (0) |
282 | |
283 | #define CFLGS_OFF_SLAB (0x80000000UL) |
284 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
285 | |
286 | #define BATCHREFILL_LIMIT 16 |
287 | /* |
288 | * Optimization question: fewer reaps means less probability for unnessary |
289 | * cpucache drain/refill cycles. |
290 | * |
291 | * OTOH the cpuarrays can contain lots of objects, |
292 | * which could lock up otherwise freeable slabs. |
293 | */ |
294 | #define REAPTIMEOUT_AC (2*HZ) |
295 | #define REAPTIMEOUT_NODE (4*HZ) |
296 | |
297 | #if STATS |
298 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
299 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
300 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
301 | #define STATS_INC_GROWN(x) ((x)->grown++) |
302 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) |
303 | #define STATS_SET_HIGH(x) \ |
304 | do { \ |
305 | if ((x)->num_active > (x)->high_mark) \ |
306 | (x)->high_mark = (x)->num_active; \ |
307 | } while (0) |
308 | #define STATS_INC_ERR(x) ((x)->errors++) |
309 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
310 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
311 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) |
312 | #define STATS_SET_FREEABLE(x, i) \ |
313 | do { \ |
314 | if ((x)->max_freeable < i) \ |
315 | (x)->max_freeable = i; \ |
316 | } while (0) |
317 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
318 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
319 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
320 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
321 | #else |
322 | #define STATS_INC_ACTIVE(x) do { } while (0) |
323 | #define STATS_DEC_ACTIVE(x) do { } while (0) |
324 | #define STATS_INC_ALLOCED(x) do { } while (0) |
325 | #define STATS_INC_GROWN(x) do { } while (0) |
326 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) |
327 | #define STATS_SET_HIGH(x) do { } while (0) |
328 | #define STATS_INC_ERR(x) do { } while (0) |
329 | #define STATS_INC_NODEALLOCS(x) do { } while (0) |
330 | #define STATS_INC_NODEFREES(x) do { } while (0) |
331 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) |
332 | #define STATS_SET_FREEABLE(x, i) do { } while (0) |
333 | #define STATS_INC_ALLOCHIT(x) do { } while (0) |
334 | #define STATS_INC_ALLOCMISS(x) do { } while (0) |
335 | #define STATS_INC_FREEHIT(x) do { } while (0) |
336 | #define STATS_INC_FREEMISS(x) do { } while (0) |
337 | #endif |
338 | |
339 | #if DEBUG |
340 | |
341 | /* |
342 | * memory layout of objects: |
343 | * 0 : objp |
344 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that |
345 | * the end of an object is aligned with the end of the real |
346 | * allocation. Catches writes behind the end of the allocation. |
347 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: |
348 | * redzone word. |
349 | * cachep->obj_offset: The real object. |
350 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
351 | * cachep->size - 1* BYTES_PER_WORD: last caller address |
352 | * [BYTES_PER_WORD long] |
353 | */ |
354 | static int obj_offset(struct kmem_cache *cachep) |
355 | { |
356 | return cachep->obj_offset; |
357 | } |
358 | |
359 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) |
360 | { |
361 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
362 | return (unsigned long long*) (objp + obj_offset(cachep) - |
363 | sizeof(unsigned long long)); |
364 | } |
365 | |
366 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) |
367 | { |
368 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
369 | if (cachep->flags & SLAB_STORE_USER) |
370 | return (unsigned long long *)(objp + cachep->size - |
371 | sizeof(unsigned long long) - |
372 | REDZONE_ALIGN); |
373 | return (unsigned long long *) (objp + cachep->size - |
374 | sizeof(unsigned long long)); |
375 | } |
376 | |
377 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) |
378 | { |
379 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
380 | return (void **)(objp + cachep->size - BYTES_PER_WORD); |
381 | } |
382 | |
383 | #else |
384 | |
385 | #define obj_offset(x) 0 |
386 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
387 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
388 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
389 | |
390 | #endif |
391 | |
392 | #define OBJECT_FREE (0) |
393 | #define OBJECT_ACTIVE (1) |
394 | |
395 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
396 | |
397 | static void set_obj_status(struct page *page, int idx, int val) |
398 | { |
399 | int freelist_size; |
400 | char *status; |
401 | struct kmem_cache *cachep = page->slab_cache; |
402 | |
403 | freelist_size = cachep->num * sizeof(freelist_idx_t); |
404 | status = (char *)page->freelist + freelist_size; |
405 | status[idx] = val; |
406 | } |
407 | |
408 | static inline unsigned int get_obj_status(struct page *page, int idx) |
409 | { |
410 | int freelist_size; |
411 | char *status; |
412 | struct kmem_cache *cachep = page->slab_cache; |
413 | |
414 | freelist_size = cachep->num * sizeof(freelist_idx_t); |
415 | status = (char *)page->freelist + freelist_size; |
416 | |
417 | return status[idx]; |
418 | } |
419 | |
420 | #else |
421 | static inline void set_obj_status(struct page *page, int idx, int val) {} |
422 | |
423 | #endif |
424 | |
425 | /* |
426 | * Do not go above this order unless 0 objects fit into the slab or |
427 | * overridden on the command line. |
428 | */ |
429 | #define SLAB_MAX_ORDER_HI 1 |
430 | #define SLAB_MAX_ORDER_LO 0 |
431 | static int slab_max_order = SLAB_MAX_ORDER_LO; |
432 | static bool slab_max_order_set __initdata; |
433 | |
434 | static inline struct kmem_cache *virt_to_cache(const void *obj) |
435 | { |
436 | struct page *page = virt_to_head_page(obj); |
437 | return page->slab_cache; |
438 | } |
439 | |
440 | static inline void *index_to_obj(struct kmem_cache *cache, struct page *page, |
441 | unsigned int idx) |
442 | { |
443 | return page->s_mem + cache->size * idx; |
444 | } |
445 | |
446 | /* |
447 | * We want to avoid an expensive divide : (offset / cache->size) |
448 | * Using the fact that size is a constant for a particular cache, |
449 | * we can replace (offset / cache->size) by |
450 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) |
451 | */ |
452 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, |
453 | const struct page *page, void *obj) |
454 | { |
455 | u32 offset = (obj - page->s_mem); |
456 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); |
457 | } |
458 | |
459 | /* internal cache of cache description objs */ |
460 | static struct kmem_cache kmem_cache_boot = { |
461 | .batchcount = 1, |
462 | .limit = BOOT_CPUCACHE_ENTRIES, |
463 | .shared = 1, |
464 | .size = sizeof(struct kmem_cache), |
465 | .name = "kmem_cache", |
466 | }; |
467 | |
468 | #define BAD_ALIEN_MAGIC 0x01020304ul |
469 | |
470 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); |
471 | |
472 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) |
473 | { |
474 | return this_cpu_ptr(cachep->cpu_cache); |
475 | } |
476 | |
477 | static size_t calculate_freelist_size(int nr_objs, size_t align) |
478 | { |
479 | size_t freelist_size; |
480 | |
481 | freelist_size = nr_objs * sizeof(freelist_idx_t); |
482 | if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK)) |
483 | freelist_size += nr_objs * sizeof(char); |
484 | |
485 | if (align) |
486 | freelist_size = ALIGN(freelist_size, align); |
487 | |
488 | return freelist_size; |
489 | } |
490 | |
491 | static int calculate_nr_objs(size_t slab_size, size_t buffer_size, |
492 | size_t idx_size, size_t align) |
493 | { |
494 | int nr_objs; |
495 | size_t remained_size; |
496 | size_t freelist_size; |
497 | int extra_space = 0; |
498 | |
499 | if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK)) |
500 | extra_space = sizeof(char); |
501 | /* |
502 | * Ignore padding for the initial guess. The padding |
503 | * is at most @align-1 bytes, and @buffer_size is at |
504 | * least @align. In the worst case, this result will |
505 | * be one greater than the number of objects that fit |
506 | * into the memory allocation when taking the padding |
507 | * into account. |
508 | */ |
509 | nr_objs = slab_size / (buffer_size + idx_size + extra_space); |
510 | |
511 | /* |
512 | * This calculated number will be either the right |
513 | * amount, or one greater than what we want. |
514 | */ |
515 | remained_size = slab_size - nr_objs * buffer_size; |
516 | freelist_size = calculate_freelist_size(nr_objs, align); |
517 | if (remained_size < freelist_size) |
518 | nr_objs--; |
519 | |
520 | return nr_objs; |
521 | } |
522 | |
523 | /* |
524 | * Calculate the number of objects and left-over bytes for a given buffer size. |
525 | */ |
526 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, |
527 | size_t align, int flags, size_t *left_over, |
528 | unsigned int *num) |
529 | { |
530 | int nr_objs; |
531 | size_t mgmt_size; |
532 | size_t slab_size = PAGE_SIZE << gfporder; |
533 | |
534 | /* |
535 | * The slab management structure can be either off the slab or |
536 | * on it. For the latter case, the memory allocated for a |
537 | * slab is used for: |
538 | * |
539 | * - One unsigned int for each object |
540 | * - Padding to respect alignment of @align |
541 | * - @buffer_size bytes for each object |
542 | * |
543 | * If the slab management structure is off the slab, then the |
544 | * alignment will already be calculated into the size. Because |
545 | * the slabs are all pages aligned, the objects will be at the |
546 | * correct alignment when allocated. |
547 | */ |
548 | if (flags & CFLGS_OFF_SLAB) { |
549 | mgmt_size = 0; |
550 | nr_objs = slab_size / buffer_size; |
551 | |
552 | } else { |
553 | nr_objs = calculate_nr_objs(slab_size, buffer_size, |
554 | sizeof(freelist_idx_t), align); |
555 | mgmt_size = calculate_freelist_size(nr_objs, align); |
556 | } |
557 | *num = nr_objs; |
558 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; |
559 | } |
560 | |
561 | #if DEBUG |
562 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) |
563 | |
564 | static void __slab_error(const char *function, struct kmem_cache *cachep, |
565 | char *msg) |
566 | { |
567 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
568 | function, cachep->name, msg); |
569 | dump_stack(); |
570 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
571 | } |
572 | #endif |
573 | |
574 | /* |
575 | * By default on NUMA we use alien caches to stage the freeing of |
576 | * objects allocated from other nodes. This causes massive memory |
577 | * inefficiencies when using fake NUMA setup to split memory into a |
578 | * large number of small nodes, so it can be disabled on the command |
579 | * line |
580 | */ |
581 | |
582 | static int use_alien_caches __read_mostly = 1; |
583 | static int __init noaliencache_setup(char *s) |
584 | { |
585 | use_alien_caches = 0; |
586 | return 1; |
587 | } |
588 | __setup("noaliencache", noaliencache_setup); |
589 | |
590 | static int __init slab_max_order_setup(char *str) |
591 | { |
592 | get_option(&str, &slab_max_order); |
593 | slab_max_order = slab_max_order < 0 ? 0 : |
594 | min(slab_max_order, MAX_ORDER - 1); |
595 | slab_max_order_set = true; |
596 | |
597 | return 1; |
598 | } |
599 | __setup("slab_max_order=", slab_max_order_setup); |
600 | |
601 | #ifdef CONFIG_NUMA |
602 | /* |
603 | * Special reaping functions for NUMA systems called from cache_reap(). |
604 | * These take care of doing round robin flushing of alien caches (containing |
605 | * objects freed on different nodes from which they were allocated) and the |
606 | * flushing of remote pcps by calling drain_node_pages. |
607 | */ |
608 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); |
609 | |
610 | static void init_reap_node(int cpu) |
611 | { |
612 | int node; |
613 | |
614 | node = next_node(cpu_to_mem(cpu), node_online_map); |
615 | if (node == MAX_NUMNODES) |
616 | node = first_node(node_online_map); |
617 | |
618 | per_cpu(slab_reap_node, cpu) = node; |
619 | } |
620 | |
621 | static void next_reap_node(void) |
622 | { |
623 | int node = __this_cpu_read(slab_reap_node); |
624 | |
625 | node = next_node(node, node_online_map); |
626 | if (unlikely(node >= MAX_NUMNODES)) |
627 | node = first_node(node_online_map); |
628 | __this_cpu_write(slab_reap_node, node); |
629 | } |
630 | |
631 | #else |
632 | #define init_reap_node(cpu) do { } while (0) |
633 | #define next_reap_node(void) do { } while (0) |
634 | #endif |
635 | |
636 | /* |
637 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
638 | * via the workqueue/eventd. |
639 | * Add the CPU number into the expiration time to minimize the possibility of |
640 | * the CPUs getting into lockstep and contending for the global cache chain |
641 | * lock. |
642 | */ |
643 | static void start_cpu_timer(int cpu) |
644 | { |
645 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); |
646 | |
647 | /* |
648 | * When this gets called from do_initcalls via cpucache_init(), |
649 | * init_workqueues() has already run, so keventd will be setup |
650 | * at that time. |
651 | */ |
652 | if (keventd_up() && reap_work->work.func == NULL) { |
653 | init_reap_node(cpu); |
654 | INIT_DEFERRABLE_WORK(reap_work, cache_reap); |
655 | schedule_delayed_work_on(cpu, reap_work, |
656 | __round_jiffies_relative(HZ, cpu)); |
657 | } |
658 | } |
659 | |
660 | static void init_arraycache(struct array_cache *ac, int limit, int batch) |
661 | { |
662 | /* |
663 | * The array_cache structures contain pointers to free object. |
664 | * However, when such objects are allocated or transferred to another |
665 | * cache the pointers are not cleared and they could be counted as |
666 | * valid references during a kmemleak scan. Therefore, kmemleak must |
667 | * not scan such objects. |
668 | */ |
669 | kmemleak_no_scan(ac); |
670 | if (ac) { |
671 | ac->avail = 0; |
672 | ac->limit = limit; |
673 | ac->batchcount = batch; |
674 | ac->touched = 0; |
675 | } |
676 | } |
677 | |
678 | static struct array_cache *alloc_arraycache(int node, int entries, |
679 | int batchcount, gfp_t gfp) |
680 | { |
681 | size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache); |
682 | struct array_cache *ac = NULL; |
683 | |
684 | ac = kmalloc_node(memsize, gfp, node); |
685 | init_arraycache(ac, entries, batchcount); |
686 | return ac; |
687 | } |
688 | |
689 | static inline bool is_slab_pfmemalloc(struct page *page) |
690 | { |
691 | return PageSlabPfmemalloc(page); |
692 | } |
693 | |
694 | /* Clears pfmemalloc_active if no slabs have pfmalloc set */ |
695 | static void recheck_pfmemalloc_active(struct kmem_cache *cachep, |
696 | struct array_cache *ac) |
697 | { |
698 | struct kmem_cache_node *n = get_node(cachep, numa_mem_id()); |
699 | struct page *page; |
700 | unsigned long flags; |
701 | |
702 | if (!pfmemalloc_active) |
703 | return; |
704 | |
705 | spin_lock_irqsave(&n->list_lock, flags); |
706 | list_for_each_entry(page, &n->slabs_full, lru) |
707 | if (is_slab_pfmemalloc(page)) |
708 | goto out; |
709 | |
710 | list_for_each_entry(page, &n->slabs_partial, lru) |
711 | if (is_slab_pfmemalloc(page)) |
712 | goto out; |
713 | |
714 | list_for_each_entry(page, &n->slabs_free, lru) |
715 | if (is_slab_pfmemalloc(page)) |
716 | goto out; |
717 | |
718 | pfmemalloc_active = false; |
719 | out: |
720 | spin_unlock_irqrestore(&n->list_lock, flags); |
721 | } |
722 | |
723 | static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, |
724 | gfp_t flags, bool force_refill) |
725 | { |
726 | int i; |
727 | void *objp = ac->entry[--ac->avail]; |
728 | |
729 | /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ |
730 | if (unlikely(is_obj_pfmemalloc(objp))) { |
731 | struct kmem_cache_node *n; |
732 | |
733 | if (gfp_pfmemalloc_allowed(flags)) { |
734 | clear_obj_pfmemalloc(&objp); |
735 | return objp; |
736 | } |
737 | |
738 | /* The caller cannot use PFMEMALLOC objects, find another one */ |
739 | for (i = 0; i < ac->avail; i++) { |
740 | /* If a !PFMEMALLOC object is found, swap them */ |
741 | if (!is_obj_pfmemalloc(ac->entry[i])) { |
742 | objp = ac->entry[i]; |
743 | ac->entry[i] = ac->entry[ac->avail]; |
744 | ac->entry[ac->avail] = objp; |
745 | return objp; |
746 | } |
747 | } |
748 | |
749 | /* |
750 | * If there are empty slabs on the slabs_free list and we are |
751 | * being forced to refill the cache, mark this one !pfmemalloc. |
752 | */ |
753 | n = get_node(cachep, numa_mem_id()); |
754 | if (!list_empty(&n->slabs_free) && force_refill) { |
755 | struct page *page = virt_to_head_page(objp); |
756 | ClearPageSlabPfmemalloc(page); |
757 | clear_obj_pfmemalloc(&objp); |
758 | recheck_pfmemalloc_active(cachep, ac); |
759 | return objp; |
760 | } |
761 | |
762 | /* No !PFMEMALLOC objects available */ |
763 | ac->avail++; |
764 | objp = NULL; |
765 | } |
766 | |
767 | return objp; |
768 | } |
769 | |
770 | static inline void *ac_get_obj(struct kmem_cache *cachep, |
771 | struct array_cache *ac, gfp_t flags, bool force_refill) |
772 | { |
773 | void *objp; |
774 | |
775 | if (unlikely(sk_memalloc_socks())) |
776 | objp = __ac_get_obj(cachep, ac, flags, force_refill); |
777 | else |
778 | objp = ac->entry[--ac->avail]; |
779 | |
780 | return objp; |
781 | } |
782 | |
783 | static noinline void *__ac_put_obj(struct kmem_cache *cachep, |
784 | struct array_cache *ac, void *objp) |
785 | { |
786 | if (unlikely(pfmemalloc_active)) { |
787 | /* Some pfmemalloc slabs exist, check if this is one */ |
788 | struct page *page = virt_to_head_page(objp); |
789 | if (PageSlabPfmemalloc(page)) |
790 | set_obj_pfmemalloc(&objp); |
791 | } |
792 | |
793 | return objp; |
794 | } |
795 | |
796 | static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
797 | void *objp) |
798 | { |
799 | if (unlikely(sk_memalloc_socks())) |
800 | objp = __ac_put_obj(cachep, ac, objp); |
801 | |
802 | ac->entry[ac->avail++] = objp; |
803 | } |
804 | |
805 | /* |
806 | * Transfer objects in one arraycache to another. |
807 | * Locking must be handled by the caller. |
808 | * |
809 | * Return the number of entries transferred. |
810 | */ |
811 | static int transfer_objects(struct array_cache *to, |
812 | struct array_cache *from, unsigned int max) |
813 | { |
814 | /* Figure out how many entries to transfer */ |
815 | int nr = min3(from->avail, max, to->limit - to->avail); |
816 | |
817 | if (!nr) |
818 | return 0; |
819 | |
820 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, |
821 | sizeof(void *) *nr); |
822 | |
823 | from->avail -= nr; |
824 | to->avail += nr; |
825 | return nr; |
826 | } |
827 | |
828 | #ifndef CONFIG_NUMA |
829 | |
830 | #define drain_alien_cache(cachep, alien) do { } while (0) |
831 | #define reap_alien(cachep, n) do { } while (0) |
832 | |
833 | static inline struct alien_cache **alloc_alien_cache(int node, |
834 | int limit, gfp_t gfp) |
835 | { |
836 | return (struct alien_cache **)BAD_ALIEN_MAGIC; |
837 | } |
838 | |
839 | static inline void free_alien_cache(struct alien_cache **ac_ptr) |
840 | { |
841 | } |
842 | |
843 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
844 | { |
845 | return 0; |
846 | } |
847 | |
848 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, |
849 | gfp_t flags) |
850 | { |
851 | return NULL; |
852 | } |
853 | |
854 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, |
855 | gfp_t flags, int nodeid) |
856 | { |
857 | return NULL; |
858 | } |
859 | |
860 | #else /* CONFIG_NUMA */ |
861 | |
862 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); |
863 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); |
864 | |
865 | static struct alien_cache *__alloc_alien_cache(int node, int entries, |
866 | int batch, gfp_t gfp) |
867 | { |
868 | size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache); |
869 | struct alien_cache *alc = NULL; |
870 | |
871 | alc = kmalloc_node(memsize, gfp, node); |
872 | init_arraycache(&alc->ac, entries, batch); |
873 | spin_lock_init(&alc->lock); |
874 | return alc; |
875 | } |
876 | |
877 | static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
878 | { |
879 | struct alien_cache **alc_ptr; |
880 | size_t memsize = sizeof(void *) * nr_node_ids; |
881 | int i; |
882 | |
883 | if (limit > 1) |
884 | limit = 12; |
885 | alc_ptr = kzalloc_node(memsize, gfp, node); |
886 | if (!alc_ptr) |
887 | return NULL; |
888 | |
889 | for_each_node(i) { |
890 | if (i == node || !node_online(i)) |
891 | continue; |
892 | alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp); |
893 | if (!alc_ptr[i]) { |
894 | for (i--; i >= 0; i--) |
895 | kfree(alc_ptr[i]); |
896 | kfree(alc_ptr); |
897 | return NULL; |
898 | } |
899 | } |
900 | return alc_ptr; |
901 | } |
902 | |
903 | static void free_alien_cache(struct alien_cache **alc_ptr) |
904 | { |
905 | int i; |
906 | |
907 | if (!alc_ptr) |
908 | return; |
909 | for_each_node(i) |
910 | kfree(alc_ptr[i]); |
911 | kfree(alc_ptr); |
912 | } |
913 | |
914 | static void __drain_alien_cache(struct kmem_cache *cachep, |
915 | struct array_cache *ac, int node, |
916 | struct list_head *list) |
917 | { |
918 | struct kmem_cache_node *n = get_node(cachep, node); |
919 | |
920 | if (ac->avail) { |
921 | spin_lock(&n->list_lock); |
922 | /* |
923 | * Stuff objects into the remote nodes shared array first. |
924 | * That way we could avoid the overhead of putting the objects |
925 | * into the free lists and getting them back later. |
926 | */ |
927 | if (n->shared) |
928 | transfer_objects(n->shared, ac, ac->limit); |
929 | |
930 | free_block(cachep, ac->entry, ac->avail, node, list); |
931 | ac->avail = 0; |
932 | spin_unlock(&n->list_lock); |
933 | } |
934 | } |
935 | |
936 | /* |
937 | * Called from cache_reap() to regularly drain alien caches round robin. |
938 | */ |
939 | static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) |
940 | { |
941 | int node = __this_cpu_read(slab_reap_node); |
942 | |
943 | if (n->alien) { |
944 | struct alien_cache *alc = n->alien[node]; |
945 | struct array_cache *ac; |
946 | |
947 | if (alc) { |
948 | ac = &alc->ac; |
949 | if (ac->avail && spin_trylock_irq(&alc->lock)) { |
950 | LIST_HEAD(list); |
951 | |
952 | __drain_alien_cache(cachep, ac, node, &list); |
953 | spin_unlock_irq(&alc->lock); |
954 | slabs_destroy(cachep, &list); |
955 | } |
956 | } |
957 | } |
958 | } |
959 | |
960 | static void drain_alien_cache(struct kmem_cache *cachep, |
961 | struct alien_cache **alien) |
962 | { |
963 | int i = 0; |
964 | struct alien_cache *alc; |
965 | struct array_cache *ac; |
966 | unsigned long flags; |
967 | |
968 | for_each_online_node(i) { |
969 | alc = alien[i]; |
970 | if (alc) { |
971 | LIST_HEAD(list); |
972 | |
973 | ac = &alc->ac; |
974 | spin_lock_irqsave(&alc->lock, flags); |
975 | __drain_alien_cache(cachep, ac, i, &list); |
976 | spin_unlock_irqrestore(&alc->lock, flags); |
977 | slabs_destroy(cachep, &list); |
978 | } |
979 | } |
980 | } |
981 | |
982 | static int __cache_free_alien(struct kmem_cache *cachep, void *objp, |
983 | int node, int page_node) |
984 | { |
985 | struct kmem_cache_node *n; |
986 | struct alien_cache *alien = NULL; |
987 | struct array_cache *ac; |
988 | LIST_HEAD(list); |
989 | |
990 | n = get_node(cachep, node); |
991 | STATS_INC_NODEFREES(cachep); |
992 | if (n->alien && n->alien[page_node]) { |
993 | alien = n->alien[page_node]; |
994 | ac = &alien->ac; |
995 | spin_lock(&alien->lock); |
996 | if (unlikely(ac->avail == ac->limit)) { |
997 | STATS_INC_ACOVERFLOW(cachep); |
998 | __drain_alien_cache(cachep, ac, page_node, &list); |
999 | } |
1000 | ac_put_obj(cachep, ac, objp); |
1001 | spin_unlock(&alien->lock); |
1002 | slabs_destroy(cachep, &list); |
1003 | } else { |
1004 | n = get_node(cachep, page_node); |
1005 | spin_lock(&n->list_lock); |
1006 | free_block(cachep, &objp, 1, page_node, &list); |
1007 | spin_unlock(&n->list_lock); |
1008 | slabs_destroy(cachep, &list); |
1009 | } |
1010 | return 1; |
1011 | } |
1012 | |
1013 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
1014 | { |
1015 | int page_node = page_to_nid(virt_to_page(objp)); |
1016 | int node = numa_mem_id(); |
1017 | /* |
1018 | * Make sure we are not freeing a object from another node to the array |
1019 | * cache on this cpu. |
1020 | */ |
1021 | if (likely(node == page_node)) |
1022 | return 0; |
1023 | |
1024 | return __cache_free_alien(cachep, objp, node, page_node); |
1025 | } |
1026 | #endif |
1027 | |
1028 | /* |
1029 | * Allocates and initializes node for a node on each slab cache, used for |
1030 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node |
1031 | * will be allocated off-node since memory is not yet online for the new node. |
1032 | * When hotplugging memory or a cpu, existing node are not replaced if |
1033 | * already in use. |
1034 | * |
1035 | * Must hold slab_mutex. |
1036 | */ |
1037 | static int init_cache_node_node(int node) |
1038 | { |
1039 | struct kmem_cache *cachep; |
1040 | struct kmem_cache_node *n; |
1041 | const size_t memsize = sizeof(struct kmem_cache_node); |
1042 | |
1043 | list_for_each_entry(cachep, &slab_caches, list) { |
1044 | /* |
1045 | * Set up the kmem_cache_node for cpu before we can |
1046 | * begin anything. Make sure some other cpu on this |
1047 | * node has not already allocated this |
1048 | */ |
1049 | n = get_node(cachep, node); |
1050 | if (!n) { |
1051 | n = kmalloc_node(memsize, GFP_KERNEL, node); |
1052 | if (!n) |
1053 | return -ENOMEM; |
1054 | kmem_cache_node_init(n); |
1055 | n->next_reap = jiffies + REAPTIMEOUT_NODE + |
1056 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
1057 | |
1058 | /* |
1059 | * The kmem_cache_nodes don't come and go as CPUs |
1060 | * come and go. slab_mutex is sufficient |
1061 | * protection here. |
1062 | */ |
1063 | cachep->node[node] = n; |
1064 | } |
1065 | |
1066 | spin_lock_irq(&n->list_lock); |
1067 | n->free_limit = |
1068 | (1 + nr_cpus_node(node)) * |
1069 | cachep->batchcount + cachep->num; |
1070 | spin_unlock_irq(&n->list_lock); |
1071 | } |
1072 | return 0; |
1073 | } |
1074 | |
1075 | static inline int slabs_tofree(struct kmem_cache *cachep, |
1076 | struct kmem_cache_node *n) |
1077 | { |
1078 | return (n->free_objects + cachep->num - 1) / cachep->num; |
1079 | } |
1080 | |
1081 | static void cpuup_canceled(long cpu) |
1082 | { |
1083 | struct kmem_cache *cachep; |
1084 | struct kmem_cache_node *n = NULL; |
1085 | int node = cpu_to_mem(cpu); |
1086 | const struct cpumask *mask = cpumask_of_node(node); |
1087 | |
1088 | list_for_each_entry(cachep, &slab_caches, list) { |
1089 | struct array_cache *nc; |
1090 | struct array_cache *shared; |
1091 | struct alien_cache **alien; |
1092 | LIST_HEAD(list); |
1093 | |
1094 | n = get_node(cachep, node); |
1095 | if (!n) |
1096 | continue; |
1097 | |
1098 | spin_lock_irq(&n->list_lock); |
1099 | |
1100 | /* Free limit for this kmem_cache_node */ |
1101 | n->free_limit -= cachep->batchcount; |
1102 | |
1103 | /* cpu is dead; no one can alloc from it. */ |
1104 | nc = per_cpu_ptr(cachep->cpu_cache, cpu); |
1105 | if (nc) { |
1106 | free_block(cachep, nc->entry, nc->avail, node, &list); |
1107 | nc->avail = 0; |
1108 | } |
1109 | |
1110 | if (!cpumask_empty(mask)) { |
1111 | spin_unlock_irq(&n->list_lock); |
1112 | goto free_slab; |
1113 | } |
1114 | |
1115 | shared = n->shared; |
1116 | if (shared) { |
1117 | free_block(cachep, shared->entry, |
1118 | shared->avail, node, &list); |
1119 | n->shared = NULL; |
1120 | } |
1121 | |
1122 | alien = n->alien; |
1123 | n->alien = NULL; |
1124 | |
1125 | spin_unlock_irq(&n->list_lock); |
1126 | |
1127 | kfree(shared); |
1128 | if (alien) { |
1129 | drain_alien_cache(cachep, alien); |
1130 | free_alien_cache(alien); |
1131 | } |
1132 | |
1133 | free_slab: |
1134 | slabs_destroy(cachep, &list); |
1135 | } |
1136 | /* |
1137 | * In the previous loop, all the objects were freed to |
1138 | * the respective cache's slabs, now we can go ahead and |
1139 | * shrink each nodelist to its limit. |
1140 | */ |
1141 | list_for_each_entry(cachep, &slab_caches, list) { |
1142 | n = get_node(cachep, node); |
1143 | if (!n) |
1144 | continue; |
1145 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
1146 | } |
1147 | } |
1148 | |
1149 | static int cpuup_prepare(long cpu) |
1150 | { |
1151 | struct kmem_cache *cachep; |
1152 | struct kmem_cache_node *n = NULL; |
1153 | int node = cpu_to_mem(cpu); |
1154 | int err; |
1155 | |
1156 | /* |
1157 | * We need to do this right in the beginning since |
1158 | * alloc_arraycache's are going to use this list. |
1159 | * kmalloc_node allows us to add the slab to the right |
1160 | * kmem_cache_node and not this cpu's kmem_cache_node |
1161 | */ |
1162 | err = init_cache_node_node(node); |
1163 | if (err < 0) |
1164 | goto bad; |
1165 | |
1166 | /* |
1167 | * Now we can go ahead with allocating the shared arrays and |
1168 | * array caches |
1169 | */ |
1170 | list_for_each_entry(cachep, &slab_caches, list) { |
1171 | struct array_cache *shared = NULL; |
1172 | struct alien_cache **alien = NULL; |
1173 | |
1174 | if (cachep->shared) { |
1175 | shared = alloc_arraycache(node, |
1176 | cachep->shared * cachep->batchcount, |
1177 | 0xbaadf00d, GFP_KERNEL); |
1178 | if (!shared) |
1179 | goto bad; |
1180 | } |
1181 | if (use_alien_caches) { |
1182 | alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); |
1183 | if (!alien) { |
1184 | kfree(shared); |
1185 | goto bad; |
1186 | } |
1187 | } |
1188 | n = get_node(cachep, node); |
1189 | BUG_ON(!n); |
1190 | |
1191 | spin_lock_irq(&n->list_lock); |
1192 | if (!n->shared) { |
1193 | /* |
1194 | * We are serialised from CPU_DEAD or |
1195 | * CPU_UP_CANCELLED by the cpucontrol lock |
1196 | */ |
1197 | n->shared = shared; |
1198 | shared = NULL; |
1199 | } |
1200 | #ifdef CONFIG_NUMA |
1201 | if (!n->alien) { |
1202 | n->alien = alien; |
1203 | alien = NULL; |
1204 | } |
1205 | #endif |
1206 | spin_unlock_irq(&n->list_lock); |
1207 | kfree(shared); |
1208 | free_alien_cache(alien); |
1209 | } |
1210 | |
1211 | return 0; |
1212 | bad: |
1213 | cpuup_canceled(cpu); |
1214 | return -ENOMEM; |
1215 | } |
1216 | |
1217 | static int cpuup_callback(struct notifier_block *nfb, |
1218 | unsigned long action, void *hcpu) |
1219 | { |
1220 | long cpu = (long)hcpu; |
1221 | int err = 0; |
1222 | |
1223 | switch (action) { |
1224 | case CPU_UP_PREPARE: |
1225 | case CPU_UP_PREPARE_FROZEN: |
1226 | mutex_lock(&slab_mutex); |
1227 | err = cpuup_prepare(cpu); |
1228 | mutex_unlock(&slab_mutex); |
1229 | break; |
1230 | case CPU_ONLINE: |
1231 | case CPU_ONLINE_FROZEN: |
1232 | start_cpu_timer(cpu); |
1233 | break; |
1234 | #ifdef CONFIG_HOTPLUG_CPU |
1235 | case CPU_DOWN_PREPARE: |
1236 | case CPU_DOWN_PREPARE_FROZEN: |
1237 | /* |
1238 | * Shutdown cache reaper. Note that the slab_mutex is |
1239 | * held so that if cache_reap() is invoked it cannot do |
1240 | * anything expensive but will only modify reap_work |
1241 | * and reschedule the timer. |
1242 | */ |
1243 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); |
1244 | /* Now the cache_reaper is guaranteed to be not running. */ |
1245 | per_cpu(slab_reap_work, cpu).work.func = NULL; |
1246 | break; |
1247 | case CPU_DOWN_FAILED: |
1248 | case CPU_DOWN_FAILED_FROZEN: |
1249 | start_cpu_timer(cpu); |
1250 | break; |
1251 | case CPU_DEAD: |
1252 | case CPU_DEAD_FROZEN: |
1253 | /* |
1254 | * Even if all the cpus of a node are down, we don't free the |
1255 | * kmem_cache_node of any cache. This to avoid a race between |
1256 | * cpu_down, and a kmalloc allocation from another cpu for |
1257 | * memory from the node of the cpu going down. The node |
1258 | * structure is usually allocated from kmem_cache_create() and |
1259 | * gets destroyed at kmem_cache_destroy(). |
1260 | */ |
1261 | /* fall through */ |
1262 | #endif |
1263 | case CPU_UP_CANCELED: |
1264 | case CPU_UP_CANCELED_FROZEN: |
1265 | mutex_lock(&slab_mutex); |
1266 | cpuup_canceled(cpu); |
1267 | mutex_unlock(&slab_mutex); |
1268 | break; |
1269 | } |
1270 | return notifier_from_errno(err); |
1271 | } |
1272 | |
1273 | static struct notifier_block cpucache_notifier = { |
1274 | &cpuup_callback, NULL, 0 |
1275 | }; |
1276 | |
1277 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
1278 | /* |
1279 | * Drains freelist for a node on each slab cache, used for memory hot-remove. |
1280 | * Returns -EBUSY if all objects cannot be drained so that the node is not |
1281 | * removed. |
1282 | * |
1283 | * Must hold slab_mutex. |
1284 | */ |
1285 | static int __meminit drain_cache_node_node(int node) |
1286 | { |
1287 | struct kmem_cache *cachep; |
1288 | int ret = 0; |
1289 | |
1290 | list_for_each_entry(cachep, &slab_caches, list) { |
1291 | struct kmem_cache_node *n; |
1292 | |
1293 | n = get_node(cachep, node); |
1294 | if (!n) |
1295 | continue; |
1296 | |
1297 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
1298 | |
1299 | if (!list_empty(&n->slabs_full) || |
1300 | !list_empty(&n->slabs_partial)) { |
1301 | ret = -EBUSY; |
1302 | break; |
1303 | } |
1304 | } |
1305 | return ret; |
1306 | } |
1307 | |
1308 | static int __meminit slab_memory_callback(struct notifier_block *self, |
1309 | unsigned long action, void *arg) |
1310 | { |
1311 | struct memory_notify *mnb = arg; |
1312 | int ret = 0; |
1313 | int nid; |
1314 | |
1315 | nid = mnb->status_change_nid; |
1316 | if (nid < 0) |
1317 | goto out; |
1318 | |
1319 | switch (action) { |
1320 | case MEM_GOING_ONLINE: |
1321 | mutex_lock(&slab_mutex); |
1322 | ret = init_cache_node_node(nid); |
1323 | mutex_unlock(&slab_mutex); |
1324 | break; |
1325 | case MEM_GOING_OFFLINE: |
1326 | mutex_lock(&slab_mutex); |
1327 | ret = drain_cache_node_node(nid); |
1328 | mutex_unlock(&slab_mutex); |
1329 | break; |
1330 | case MEM_ONLINE: |
1331 | case MEM_OFFLINE: |
1332 | case MEM_CANCEL_ONLINE: |
1333 | case MEM_CANCEL_OFFLINE: |
1334 | break; |
1335 | } |
1336 | out: |
1337 | return notifier_from_errno(ret); |
1338 | } |
1339 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ |
1340 | |
1341 | /* |
1342 | * swap the static kmem_cache_node with kmalloced memory |
1343 | */ |
1344 | static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, |
1345 | int nodeid) |
1346 | { |
1347 | struct kmem_cache_node *ptr; |
1348 | |
1349 | ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); |
1350 | BUG_ON(!ptr); |
1351 | |
1352 | memcpy(ptr, list, sizeof(struct kmem_cache_node)); |
1353 | /* |
1354 | * Do not assume that spinlocks can be initialized via memcpy: |
1355 | */ |
1356 | spin_lock_init(&ptr->list_lock); |
1357 | |
1358 | MAKE_ALL_LISTS(cachep, ptr, nodeid); |
1359 | cachep->node[nodeid] = ptr; |
1360 | } |
1361 | |
1362 | /* |
1363 | * For setting up all the kmem_cache_node for cache whose buffer_size is same as |
1364 | * size of kmem_cache_node. |
1365 | */ |
1366 | static void __init set_up_node(struct kmem_cache *cachep, int index) |
1367 | { |
1368 | int node; |
1369 | |
1370 | for_each_online_node(node) { |
1371 | cachep->node[node] = &init_kmem_cache_node[index + node]; |
1372 | cachep->node[node]->next_reap = jiffies + |
1373 | REAPTIMEOUT_NODE + |
1374 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
1375 | } |
1376 | } |
1377 | |
1378 | /* |
1379 | * Initialisation. Called after the page allocator have been initialised and |
1380 | * before smp_init(). |
1381 | */ |
1382 | void __init kmem_cache_init(void) |
1383 | { |
1384 | int i; |
1385 | |
1386 | BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) < |
1387 | sizeof(struct rcu_head)); |
1388 | kmem_cache = &kmem_cache_boot; |
1389 | |
1390 | if (num_possible_nodes() == 1) |
1391 | use_alien_caches = 0; |
1392 | |
1393 | for (i = 0; i < NUM_INIT_LISTS; i++) |
1394 | kmem_cache_node_init(&init_kmem_cache_node[i]); |
1395 | |
1396 | /* |
1397 | * Fragmentation resistance on low memory - only use bigger |
1398 | * page orders on machines with more than 32MB of memory if |
1399 | * not overridden on the command line. |
1400 | */ |
1401 | if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) |
1402 | slab_max_order = SLAB_MAX_ORDER_HI; |
1403 | |
1404 | /* Bootstrap is tricky, because several objects are allocated |
1405 | * from caches that do not exist yet: |
1406 | * 1) initialize the kmem_cache cache: it contains the struct |
1407 | * kmem_cache structures of all caches, except kmem_cache itself: |
1408 | * kmem_cache is statically allocated. |
1409 | * Initially an __init data area is used for the head array and the |
1410 | * kmem_cache_node structures, it's replaced with a kmalloc allocated |
1411 | * array at the end of the bootstrap. |
1412 | * 2) Create the first kmalloc cache. |
1413 | * The struct kmem_cache for the new cache is allocated normally. |
1414 | * An __init data area is used for the head array. |
1415 | * 3) Create the remaining kmalloc caches, with minimally sized |
1416 | * head arrays. |
1417 | * 4) Replace the __init data head arrays for kmem_cache and the first |
1418 | * kmalloc cache with kmalloc allocated arrays. |
1419 | * 5) Replace the __init data for kmem_cache_node for kmem_cache and |
1420 | * the other cache's with kmalloc allocated memory. |
1421 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. |
1422 | */ |
1423 | |
1424 | /* 1) create the kmem_cache */ |
1425 | |
1426 | /* |
1427 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids |
1428 | */ |
1429 | create_boot_cache(kmem_cache, "kmem_cache", |
1430 | offsetof(struct kmem_cache, node) + |
1431 | nr_node_ids * sizeof(struct kmem_cache_node *), |
1432 | SLAB_HWCACHE_ALIGN); |
1433 | list_add(&kmem_cache->list, &slab_caches); |
1434 | slab_state = PARTIAL; |
1435 | |
1436 | /* |
1437 | * Initialize the caches that provide memory for the kmem_cache_node |
1438 | * structures first. Without this, further allocations will bug. |
1439 | */ |
1440 | kmalloc_caches[INDEX_NODE] = create_kmalloc_cache("kmalloc-node", |
1441 | kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); |
1442 | slab_state = PARTIAL_NODE; |
1443 | |
1444 | slab_early_init = 0; |
1445 | |
1446 | /* 5) Replace the bootstrap kmem_cache_node */ |
1447 | { |
1448 | int nid; |
1449 | |
1450 | for_each_online_node(nid) { |
1451 | init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); |
1452 | |
1453 | init_list(kmalloc_caches[INDEX_NODE], |
1454 | &init_kmem_cache_node[SIZE_NODE + nid], nid); |
1455 | } |
1456 | } |
1457 | |
1458 | create_kmalloc_caches(ARCH_KMALLOC_FLAGS); |
1459 | } |
1460 | |
1461 | void __init kmem_cache_init_late(void) |
1462 | { |
1463 | struct kmem_cache *cachep; |
1464 | |
1465 | slab_state = UP; |
1466 | |
1467 | /* 6) resize the head arrays to their final sizes */ |
1468 | mutex_lock(&slab_mutex); |
1469 | list_for_each_entry(cachep, &slab_caches, list) |
1470 | if (enable_cpucache(cachep, GFP_NOWAIT)) |
1471 | BUG(); |
1472 | mutex_unlock(&slab_mutex); |
1473 | |
1474 | /* Done! */ |
1475 | slab_state = FULL; |
1476 | |
1477 | /* |
1478 | * Register a cpu startup notifier callback that initializes |
1479 | * cpu_cache_get for all new cpus |
1480 | */ |
1481 | register_cpu_notifier(&cpucache_notifier); |
1482 | |
1483 | #ifdef CONFIG_NUMA |
1484 | /* |
1485 | * Register a memory hotplug callback that initializes and frees |
1486 | * node. |
1487 | */ |
1488 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
1489 | #endif |
1490 | |
1491 | /* |
1492 | * The reap timers are started later, with a module init call: That part |
1493 | * of the kernel is not yet operational. |
1494 | */ |
1495 | } |
1496 | |
1497 | static int __init cpucache_init(void) |
1498 | { |
1499 | int cpu; |
1500 | |
1501 | /* |
1502 | * Register the timers that return unneeded pages to the page allocator |
1503 | */ |
1504 | for_each_online_cpu(cpu) |
1505 | start_cpu_timer(cpu); |
1506 | |
1507 | /* Done! */ |
1508 | slab_state = FULL; |
1509 | return 0; |
1510 | } |
1511 | __initcall(cpucache_init); |
1512 | |
1513 | static noinline void |
1514 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) |
1515 | { |
1516 | #if DEBUG |
1517 | struct kmem_cache_node *n; |
1518 | struct page *page; |
1519 | unsigned long flags; |
1520 | int node; |
1521 | static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL, |
1522 | DEFAULT_RATELIMIT_BURST); |
1523 | |
1524 | if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs)) |
1525 | return; |
1526 | |
1527 | printk(KERN_WARNING |
1528 | "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
1529 | nodeid, gfpflags); |
1530 | printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", |
1531 | cachep->name, cachep->size, cachep->gfporder); |
1532 | |
1533 | for_each_kmem_cache_node(cachep, node, n) { |
1534 | unsigned long active_objs = 0, num_objs = 0, free_objects = 0; |
1535 | unsigned long active_slabs = 0, num_slabs = 0; |
1536 | |
1537 | spin_lock_irqsave(&n->list_lock, flags); |
1538 | list_for_each_entry(page, &n->slabs_full, lru) { |
1539 | active_objs += cachep->num; |
1540 | active_slabs++; |
1541 | } |
1542 | list_for_each_entry(page, &n->slabs_partial, lru) { |
1543 | active_objs += page->active; |
1544 | active_slabs++; |
1545 | } |
1546 | list_for_each_entry(page, &n->slabs_free, lru) |
1547 | num_slabs++; |
1548 | |
1549 | free_objects += n->free_objects; |
1550 | spin_unlock_irqrestore(&n->list_lock, flags); |
1551 | |
1552 | num_slabs += active_slabs; |
1553 | num_objs = num_slabs * cachep->num; |
1554 | printk(KERN_WARNING |
1555 | " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", |
1556 | node, active_slabs, num_slabs, active_objs, num_objs, |
1557 | free_objects); |
1558 | } |
1559 | #endif |
1560 | } |
1561 | |
1562 | /* |
1563 | * Interface to system's page allocator. No need to hold the |
1564 | * kmem_cache_node ->list_lock. |
1565 | * |
1566 | * If we requested dmaable memory, we will get it. Even if we |
1567 | * did not request dmaable memory, we might get it, but that |
1568 | * would be relatively rare and ignorable. |
1569 | */ |
1570 | static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, |
1571 | int nodeid) |
1572 | { |
1573 | struct page *page; |
1574 | int nr_pages; |
1575 | |
1576 | flags |= cachep->allocflags; |
1577 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1578 | flags |= __GFP_RECLAIMABLE; |
1579 | |
1580 | if (memcg_charge_slab(cachep, flags, cachep->gfporder)) |
1581 | return NULL; |
1582 | |
1583 | page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); |
1584 | if (!page) { |
1585 | memcg_uncharge_slab(cachep, cachep->gfporder); |
1586 | slab_out_of_memory(cachep, flags, nodeid); |
1587 | return NULL; |
1588 | } |
1589 | |
1590 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ |
1591 | if (unlikely(page->pfmemalloc)) |
1592 | pfmemalloc_active = true; |
1593 | |
1594 | nr_pages = (1 << cachep->gfporder); |
1595 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1596 | add_zone_page_state(page_zone(page), |
1597 | NR_SLAB_RECLAIMABLE, nr_pages); |
1598 | else |
1599 | add_zone_page_state(page_zone(page), |
1600 | NR_SLAB_UNRECLAIMABLE, nr_pages); |
1601 | __SetPageSlab(page); |
1602 | if (page->pfmemalloc) |
1603 | SetPageSlabPfmemalloc(page); |
1604 | |
1605 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { |
1606 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); |
1607 | |
1608 | if (cachep->ctor) |
1609 | kmemcheck_mark_uninitialized_pages(page, nr_pages); |
1610 | else |
1611 | kmemcheck_mark_unallocated_pages(page, nr_pages); |
1612 | } |
1613 | |
1614 | return page; |
1615 | } |
1616 | |
1617 | /* |
1618 | * Interface to system's page release. |
1619 | */ |
1620 | static void kmem_freepages(struct kmem_cache *cachep, struct page *page) |
1621 | { |
1622 | const unsigned long nr_freed = (1 << cachep->gfporder); |
1623 | |
1624 | kmemcheck_free_shadow(page, cachep->gfporder); |
1625 | |
1626 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1627 | sub_zone_page_state(page_zone(page), |
1628 | NR_SLAB_RECLAIMABLE, nr_freed); |
1629 | else |
1630 | sub_zone_page_state(page_zone(page), |
1631 | NR_SLAB_UNRECLAIMABLE, nr_freed); |
1632 | |
1633 | BUG_ON(!PageSlab(page)); |
1634 | __ClearPageSlabPfmemalloc(page); |
1635 | __ClearPageSlab(page); |
1636 | page_mapcount_reset(page); |
1637 | page->mapping = NULL; |
1638 | |
1639 | if (current->reclaim_state) |
1640 | current->reclaim_state->reclaimed_slab += nr_freed; |
1641 | __free_pages(page, cachep->gfporder); |
1642 | memcg_uncharge_slab(cachep, cachep->gfporder); |
1643 | } |
1644 | |
1645 | static void kmem_rcu_free(struct rcu_head *head) |
1646 | { |
1647 | struct kmem_cache *cachep; |
1648 | struct page *page; |
1649 | |
1650 | page = container_of(head, struct page, rcu_head); |
1651 | cachep = page->slab_cache; |
1652 | |
1653 | kmem_freepages(cachep, page); |
1654 | } |
1655 | |
1656 | #if DEBUG |
1657 | |
1658 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1659 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, |
1660 | unsigned long caller) |
1661 | { |
1662 | int size = cachep->object_size; |
1663 | |
1664 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; |
1665 | |
1666 | if (size < 5 * sizeof(unsigned long)) |
1667 | return; |
1668 | |
1669 | *addr++ = 0x12345678; |
1670 | *addr++ = caller; |
1671 | *addr++ = smp_processor_id(); |
1672 | size -= 3 * sizeof(unsigned long); |
1673 | { |
1674 | unsigned long *sptr = &caller; |
1675 | unsigned long svalue; |
1676 | |
1677 | while (!kstack_end(sptr)) { |
1678 | svalue = *sptr++; |
1679 | if (kernel_text_address(svalue)) { |
1680 | *addr++ = svalue; |
1681 | size -= sizeof(unsigned long); |
1682 | if (size <= sizeof(unsigned long)) |
1683 | break; |
1684 | } |
1685 | } |
1686 | |
1687 | } |
1688 | *addr++ = 0x87654321; |
1689 | } |
1690 | #endif |
1691 | |
1692 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) |
1693 | { |
1694 | int size = cachep->object_size; |
1695 | addr = &((char *)addr)[obj_offset(cachep)]; |
1696 | |
1697 | memset(addr, val, size); |
1698 | *(unsigned char *)(addr + size - 1) = POISON_END; |
1699 | } |
1700 | |
1701 | static void dump_line(char *data, int offset, int limit) |
1702 | { |
1703 | int i; |
1704 | unsigned char error = 0; |
1705 | int bad_count = 0; |
1706 | |
1707 | printk(KERN_ERR "%03x: ", offset); |
1708 | for (i = 0; i < limit; i++) { |
1709 | if (data[offset + i] != POISON_FREE) { |
1710 | error = data[offset + i]; |
1711 | bad_count++; |
1712 | } |
1713 | } |
1714 | print_hex_dump(KERN_CONT, "", 0, 16, 1, |
1715 | &data[offset], limit, 1); |
1716 | |
1717 | if (bad_count == 1) { |
1718 | error ^= POISON_FREE; |
1719 | if (!(error & (error - 1))) { |
1720 | printk(KERN_ERR "Single bit error detected. Probably " |
1721 | "bad RAM.\n"); |
1722 | #ifdef CONFIG_X86 |
1723 | printk(KERN_ERR "Run memtest86+ or a similar memory " |
1724 | "test tool.\n"); |
1725 | #else |
1726 | printk(KERN_ERR "Run a memory test tool.\n"); |
1727 | #endif |
1728 | } |
1729 | } |
1730 | } |
1731 | #endif |
1732 | |
1733 | #if DEBUG |
1734 | |
1735 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) |
1736 | { |
1737 | int i, size; |
1738 | char *realobj; |
1739 | |
1740 | if (cachep->flags & SLAB_RED_ZONE) { |
1741 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", |
1742 | *dbg_redzone1(cachep, objp), |
1743 | *dbg_redzone2(cachep, objp)); |
1744 | } |
1745 | |
1746 | if (cachep->flags & SLAB_STORE_USER) { |
1747 | printk(KERN_ERR "Last user: [<%p>](%pSR)\n", |
1748 | *dbg_userword(cachep, objp), |
1749 | *dbg_userword(cachep, objp)); |
1750 | } |
1751 | realobj = (char *)objp + obj_offset(cachep); |
1752 | size = cachep->object_size; |
1753 | for (i = 0; i < size && lines; i += 16, lines--) { |
1754 | int limit; |
1755 | limit = 16; |
1756 | if (i + limit > size) |
1757 | limit = size - i; |
1758 | dump_line(realobj, i, limit); |
1759 | } |
1760 | } |
1761 | |
1762 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) |
1763 | { |
1764 | char *realobj; |
1765 | int size, i; |
1766 | int lines = 0; |
1767 | |
1768 | realobj = (char *)objp + obj_offset(cachep); |
1769 | size = cachep->object_size; |
1770 | |
1771 | for (i = 0; i < size; i++) { |
1772 | char exp = POISON_FREE; |
1773 | if (i == size - 1) |
1774 | exp = POISON_END; |
1775 | if (realobj[i] != exp) { |
1776 | int limit; |
1777 | /* Mismatch ! */ |
1778 | /* Print header */ |
1779 | if (lines == 0) { |
1780 | printk(KERN_ERR |
1781 | "Slab corruption (%s): %s start=%p, len=%d\n", |
1782 | print_tainted(), cachep->name, realobj, size); |
1783 | print_objinfo(cachep, objp, 0); |
1784 | } |
1785 | /* Hexdump the affected line */ |
1786 | i = (i / 16) * 16; |
1787 | limit = 16; |
1788 | if (i + limit > size) |
1789 | limit = size - i; |
1790 | dump_line(realobj, i, limit); |
1791 | i += 16; |
1792 | lines++; |
1793 | /* Limit to 5 lines */ |
1794 | if (lines > 5) |
1795 | break; |
1796 | } |
1797 | } |
1798 | if (lines != 0) { |
1799 | /* Print some data about the neighboring objects, if they |
1800 | * exist: |
1801 | */ |
1802 | struct page *page = virt_to_head_page(objp); |
1803 | unsigned int objnr; |
1804 | |
1805 | objnr = obj_to_index(cachep, page, objp); |
1806 | if (objnr) { |
1807 | objp = index_to_obj(cachep, page, objnr - 1); |
1808 | realobj = (char *)objp + obj_offset(cachep); |
1809 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
1810 | realobj, size); |
1811 | print_objinfo(cachep, objp, 2); |
1812 | } |
1813 | if (objnr + 1 < cachep->num) { |
1814 | objp = index_to_obj(cachep, page, objnr + 1); |
1815 | realobj = (char *)objp + obj_offset(cachep); |
1816 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
1817 | realobj, size); |
1818 | print_objinfo(cachep, objp, 2); |
1819 | } |
1820 | } |
1821 | } |
1822 | #endif |
1823 | |
1824 | #if DEBUG |
1825 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
1826 | struct page *page) |
1827 | { |
1828 | int i; |
1829 | for (i = 0; i < cachep->num; i++) { |
1830 | void *objp = index_to_obj(cachep, page, i); |
1831 | |
1832 | if (cachep->flags & SLAB_POISON) { |
1833 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1834 | if (cachep->size % PAGE_SIZE == 0 && |
1835 | OFF_SLAB(cachep)) |
1836 | kernel_map_pages(virt_to_page(objp), |
1837 | cachep->size / PAGE_SIZE, 1); |
1838 | else |
1839 | check_poison_obj(cachep, objp); |
1840 | #else |
1841 | check_poison_obj(cachep, objp); |
1842 | #endif |
1843 | } |
1844 | if (cachep->flags & SLAB_RED_ZONE) { |
1845 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
1846 | slab_error(cachep, "start of a freed object " |
1847 | "was overwritten"); |
1848 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
1849 | slab_error(cachep, "end of a freed object " |
1850 | "was overwritten"); |
1851 | } |
1852 | } |
1853 | } |
1854 | #else |
1855 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
1856 | struct page *page) |
1857 | { |
1858 | } |
1859 | #endif |
1860 | |
1861 | /** |
1862 | * slab_destroy - destroy and release all objects in a slab |
1863 | * @cachep: cache pointer being destroyed |
1864 | * @page: page pointer being destroyed |
1865 | * |
1866 | * Destroy all the objs in a slab page, and release the mem back to the system. |
1867 | * Before calling the slab page must have been unlinked from the cache. The |
1868 | * kmem_cache_node ->list_lock is not held/needed. |
1869 | */ |
1870 | static void slab_destroy(struct kmem_cache *cachep, struct page *page) |
1871 | { |
1872 | void *freelist; |
1873 | |
1874 | freelist = page->freelist; |
1875 | slab_destroy_debugcheck(cachep, page); |
1876 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { |
1877 | struct rcu_head *head; |
1878 | |
1879 | /* |
1880 | * RCU free overloads the RCU head over the LRU. |
1881 | * slab_page has been overloeaded over the LRU, |
1882 | * however it is not used from now on so that |
1883 | * we can use it safely. |
1884 | */ |
1885 | head = (void *)&page->rcu_head; |
1886 | call_rcu(head, kmem_rcu_free); |
1887 | |
1888 | } else { |
1889 | kmem_freepages(cachep, page); |
1890 | } |
1891 | |
1892 | /* |
1893 | * From now on, we don't use freelist |
1894 | * although actual page can be freed in rcu context |
1895 | */ |
1896 | if (OFF_SLAB(cachep)) |
1897 | kmem_cache_free(cachep->freelist_cache, freelist); |
1898 | } |
1899 | |
1900 | static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list) |
1901 | { |
1902 | struct page *page, *n; |
1903 | |
1904 | list_for_each_entry_safe(page, n, list, lru) { |
1905 | list_del(&page->lru); |
1906 | slab_destroy(cachep, page); |
1907 | } |
1908 | } |
1909 | |
1910 | /** |
1911 | * calculate_slab_order - calculate size (page order) of slabs |
1912 | * @cachep: pointer to the cache that is being created |
1913 | * @size: size of objects to be created in this cache. |
1914 | * @align: required alignment for the objects. |
1915 | * @flags: slab allocation flags |
1916 | * |
1917 | * Also calculates the number of objects per slab. |
1918 | * |
1919 | * This could be made much more intelligent. For now, try to avoid using |
1920 | * high order pages for slabs. When the gfp() functions are more friendly |
1921 | * towards high-order requests, this should be changed. |
1922 | */ |
1923 | static size_t calculate_slab_order(struct kmem_cache *cachep, |
1924 | size_t size, size_t align, unsigned long flags) |
1925 | { |
1926 | unsigned long offslab_limit; |
1927 | size_t left_over = 0; |
1928 | int gfporder; |
1929 | |
1930 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { |
1931 | unsigned int num; |
1932 | size_t remainder; |
1933 | |
1934 | cache_estimate(gfporder, size, align, flags, &remainder, &num); |
1935 | if (!num) |
1936 | continue; |
1937 | |
1938 | /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */ |
1939 | if (num > SLAB_OBJ_MAX_NUM) |
1940 | break; |
1941 | |
1942 | if (flags & CFLGS_OFF_SLAB) { |
1943 | size_t freelist_size_per_obj = sizeof(freelist_idx_t); |
1944 | /* |
1945 | * Max number of objs-per-slab for caches which |
1946 | * use off-slab slabs. Needed to avoid a possible |
1947 | * looping condition in cache_grow(). |
1948 | */ |
1949 | if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK)) |
1950 | freelist_size_per_obj += sizeof(char); |
1951 | offslab_limit = size; |
1952 | offslab_limit /= freelist_size_per_obj; |
1953 | |
1954 | if (num > offslab_limit) |
1955 | break; |
1956 | } |
1957 | |
1958 | /* Found something acceptable - save it away */ |
1959 | cachep->num = num; |
1960 | cachep->gfporder = gfporder; |
1961 | left_over = remainder; |
1962 | |
1963 | /* |
1964 | * A VFS-reclaimable slab tends to have most allocations |
1965 | * as GFP_NOFS and we really don't want to have to be allocating |
1966 | * higher-order pages when we are unable to shrink dcache. |
1967 | */ |
1968 | if (flags & SLAB_RECLAIM_ACCOUNT) |
1969 | break; |
1970 | |
1971 | /* |
1972 | * Large number of objects is good, but very large slabs are |
1973 | * currently bad for the gfp()s. |
1974 | */ |
1975 | if (gfporder >= slab_max_order) |
1976 | break; |
1977 | |
1978 | /* |
1979 | * Acceptable internal fragmentation? |
1980 | */ |
1981 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) |
1982 | break; |
1983 | } |
1984 | return left_over; |
1985 | } |
1986 | |
1987 | static struct array_cache __percpu *alloc_kmem_cache_cpus( |
1988 | struct kmem_cache *cachep, int entries, int batchcount) |
1989 | { |
1990 | int cpu; |
1991 | size_t size; |
1992 | struct array_cache __percpu *cpu_cache; |
1993 | |
1994 | size = sizeof(void *) * entries + sizeof(struct array_cache); |
1995 | cpu_cache = __alloc_percpu(size, sizeof(void *)); |
1996 | |
1997 | if (!cpu_cache) |
1998 | return NULL; |
1999 | |
2000 | for_each_possible_cpu(cpu) { |
2001 | init_arraycache(per_cpu_ptr(cpu_cache, cpu), |
2002 | entries, batchcount); |
2003 | } |
2004 | |
2005 | return cpu_cache; |
2006 | } |
2007 | |
2008 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) |
2009 | { |
2010 | if (slab_state >= FULL) |
2011 | return enable_cpucache(cachep, gfp); |
2012 | |
2013 | cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1); |
2014 | if (!cachep->cpu_cache) |
2015 | return 1; |
2016 | |
2017 | if (slab_state == DOWN) { |
2018 | /* Creation of first cache (kmem_cache). */ |
2019 | set_up_node(kmem_cache, CACHE_CACHE); |
2020 | } else if (slab_state == PARTIAL) { |
2021 | /* For kmem_cache_node */ |
2022 | set_up_node(cachep, SIZE_NODE); |
2023 | } else { |
2024 | int node; |
2025 | |
2026 | for_each_online_node(node) { |
2027 | cachep->node[node] = kmalloc_node( |
2028 | sizeof(struct kmem_cache_node), gfp, node); |
2029 | BUG_ON(!cachep->node[node]); |
2030 | kmem_cache_node_init(cachep->node[node]); |
2031 | } |
2032 | } |
2033 | |
2034 | cachep->node[numa_mem_id()]->next_reap = |
2035 | jiffies + REAPTIMEOUT_NODE + |
2036 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
2037 | |
2038 | cpu_cache_get(cachep)->avail = 0; |
2039 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
2040 | cpu_cache_get(cachep)->batchcount = 1; |
2041 | cpu_cache_get(cachep)->touched = 0; |
2042 | cachep->batchcount = 1; |
2043 | cachep->limit = BOOT_CPUCACHE_ENTRIES; |
2044 | return 0; |
2045 | } |
2046 | |
2047 | unsigned long kmem_cache_flags(unsigned long object_size, |
2048 | unsigned long flags, const char *name, |
2049 | void (*ctor)(void *)) |
2050 | { |
2051 | return flags; |
2052 | } |
2053 | |
2054 | struct kmem_cache * |
2055 | __kmem_cache_alias(const char *name, size_t size, size_t align, |
2056 | unsigned long flags, void (*ctor)(void *)) |
2057 | { |
2058 | struct kmem_cache *cachep; |
2059 | |
2060 | cachep = find_mergeable(size, align, flags, name, ctor); |
2061 | if (cachep) { |
2062 | cachep->refcount++; |
2063 | |
2064 | /* |
2065 | * Adjust the object sizes so that we clear |
2066 | * the complete object on kzalloc. |
2067 | */ |
2068 | cachep->object_size = max_t(int, cachep->object_size, size); |
2069 | } |
2070 | return cachep; |
2071 | } |
2072 | |
2073 | /** |
2074 | * __kmem_cache_create - Create a cache. |
2075 | * @cachep: cache management descriptor |
2076 | * @flags: SLAB flags |
2077 | * |
2078 | * Returns a ptr to the cache on success, NULL on failure. |
2079 | * Cannot be called within a int, but can be interrupted. |
2080 | * The @ctor is run when new pages are allocated by the cache. |
2081 | * |
2082 | * The flags are |
2083 | * |
2084 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
2085 | * to catch references to uninitialised memory. |
2086 | * |
2087 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
2088 | * for buffer overruns. |
2089 | * |
2090 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
2091 | * cacheline. This can be beneficial if you're counting cycles as closely |
2092 | * as davem. |
2093 | */ |
2094 | int |
2095 | __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) |
2096 | { |
2097 | size_t left_over, freelist_size; |
2098 | size_t ralign = BYTES_PER_WORD; |
2099 | gfp_t gfp; |
2100 | int err; |
2101 | size_t size = cachep->size; |
2102 | |
2103 | #if DEBUG |
2104 | #if FORCED_DEBUG |
2105 | /* |
2106 | * Enable redzoning and last user accounting, except for caches with |
2107 | * large objects, if the increased size would increase the object size |
2108 | * above the next power of two: caches with object sizes just above a |
2109 | * power of two have a significant amount of internal fragmentation. |
2110 | */ |
2111 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + |
2112 | 2 * sizeof(unsigned long long))) |
2113 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; |
2114 | if (!(flags & SLAB_DESTROY_BY_RCU)) |
2115 | flags |= SLAB_POISON; |
2116 | #endif |
2117 | if (flags & SLAB_DESTROY_BY_RCU) |
2118 | BUG_ON(flags & SLAB_POISON); |
2119 | #endif |
2120 | |
2121 | /* |
2122 | * Check that size is in terms of words. This is needed to avoid |
2123 | * unaligned accesses for some archs when redzoning is used, and makes |
2124 | * sure any on-slab bufctl's are also correctly aligned. |
2125 | */ |
2126 | if (size & (BYTES_PER_WORD - 1)) { |
2127 | size += (BYTES_PER_WORD - 1); |
2128 | size &= ~(BYTES_PER_WORD - 1); |
2129 | } |
2130 | |
2131 | if (flags & SLAB_RED_ZONE) { |
2132 | ralign = REDZONE_ALIGN; |
2133 | /* If redzoning, ensure that the second redzone is suitably |
2134 | * aligned, by adjusting the object size accordingly. */ |
2135 | size += REDZONE_ALIGN - 1; |
2136 | size &= ~(REDZONE_ALIGN - 1); |
2137 | } |
2138 | |
2139 | /* 3) caller mandated alignment */ |
2140 | if (ralign < cachep->align) { |
2141 | ralign = cachep->align; |
2142 | } |
2143 | /* disable debug if necessary */ |
2144 | if (ralign > __alignof__(unsigned long long)) |
2145 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2146 | /* |
2147 | * 4) Store it. |
2148 | */ |
2149 | cachep->align = ralign; |
2150 | |
2151 | if (slab_is_available()) |
2152 | gfp = GFP_KERNEL; |
2153 | else |
2154 | gfp = GFP_NOWAIT; |
2155 | |
2156 | #if DEBUG |
2157 | |
2158 | /* |
2159 | * Both debugging options require word-alignment which is calculated |
2160 | * into align above. |
2161 | */ |
2162 | if (flags & SLAB_RED_ZONE) { |
2163 | /* add space for red zone words */ |
2164 | cachep->obj_offset += sizeof(unsigned long long); |
2165 | size += 2 * sizeof(unsigned long long); |
2166 | } |
2167 | if (flags & SLAB_STORE_USER) { |
2168 | /* user store requires one word storage behind the end of |
2169 | * the real object. But if the second red zone needs to be |
2170 | * aligned to 64 bits, we must allow that much space. |
2171 | */ |
2172 | if (flags & SLAB_RED_ZONE) |
2173 | size += REDZONE_ALIGN; |
2174 | else |
2175 | size += BYTES_PER_WORD; |
2176 | } |
2177 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
2178 | if (size >= kmalloc_size(INDEX_NODE + 1) |
2179 | && cachep->object_size > cache_line_size() |
2180 | && ALIGN(size, cachep->align) < PAGE_SIZE) { |
2181 | cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align); |
2182 | size = PAGE_SIZE; |
2183 | } |
2184 | #endif |
2185 | #endif |
2186 | |
2187 | /* |
2188 | * Determine if the slab management is 'on' or 'off' slab. |
2189 | * (bootstrapping cannot cope with offslab caches so don't do |
2190 | * it too early on. Always use on-slab management when |
2191 | * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) |
2192 | */ |
2193 | if ((size >= (PAGE_SIZE >> 5)) && !slab_early_init && |
2194 | !(flags & SLAB_NOLEAKTRACE)) |
2195 | /* |
2196 | * Size is large, assume best to place the slab management obj |
2197 | * off-slab (should allow better packing of objs). |
2198 | */ |
2199 | flags |= CFLGS_OFF_SLAB; |
2200 | |
2201 | size = ALIGN(size, cachep->align); |
2202 | /* |
2203 | * We should restrict the number of objects in a slab to implement |
2204 | * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition. |
2205 | */ |
2206 | if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE) |
2207 | size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align); |
2208 | |
2209 | left_over = calculate_slab_order(cachep, size, cachep->align, flags); |
2210 | |
2211 | if (!cachep->num) |
2212 | return -E2BIG; |
2213 | |
2214 | freelist_size = calculate_freelist_size(cachep->num, cachep->align); |
2215 | |
2216 | /* |
2217 | * If the slab has been placed off-slab, and we have enough space then |
2218 | * move it on-slab. This is at the expense of any extra colouring. |
2219 | */ |
2220 | if (flags & CFLGS_OFF_SLAB && left_over >= freelist_size) { |
2221 | flags &= ~CFLGS_OFF_SLAB; |
2222 | left_over -= freelist_size; |
2223 | } |
2224 | |
2225 | if (flags & CFLGS_OFF_SLAB) { |
2226 | /* really off slab. No need for manual alignment */ |
2227 | freelist_size = calculate_freelist_size(cachep->num, 0); |
2228 | |
2229 | #ifdef CONFIG_PAGE_POISONING |
2230 | /* If we're going to use the generic kernel_map_pages() |
2231 | * poisoning, then it's going to smash the contents of |
2232 | * the redzone and userword anyhow, so switch them off. |
2233 | */ |
2234 | if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) |
2235 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2236 | #endif |
2237 | } |
2238 | |
2239 | cachep->colour_off = cache_line_size(); |
2240 | /* Offset must be a multiple of the alignment. */ |
2241 | if (cachep->colour_off < cachep->align) |
2242 | cachep->colour_off = cachep->align; |
2243 | cachep->colour = left_over / cachep->colour_off; |
2244 | cachep->freelist_size = freelist_size; |
2245 | cachep->flags = flags; |
2246 | cachep->allocflags = __GFP_COMP; |
2247 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) |
2248 | cachep->allocflags |= GFP_DMA; |
2249 | cachep->size = size; |
2250 | cachep->reciprocal_buffer_size = reciprocal_value(size); |
2251 | |
2252 | if (flags & CFLGS_OFF_SLAB) { |
2253 | cachep->freelist_cache = kmalloc_slab(freelist_size, 0u); |
2254 | /* |
2255 | * This is a possibility for one of the kmalloc_{dma,}_caches. |
2256 | * But since we go off slab only for object size greater than |
2257 | * PAGE_SIZE/8, and kmalloc_{dma,}_caches get created |
2258 | * in ascending order,this should not happen at all. |
2259 | * But leave a BUG_ON for some lucky dude. |
2260 | */ |
2261 | BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache)); |
2262 | } |
2263 | |
2264 | err = setup_cpu_cache(cachep, gfp); |
2265 | if (err) { |
2266 | __kmem_cache_shutdown(cachep); |
2267 | return err; |
2268 | } |
2269 | |
2270 | return 0; |
2271 | } |
2272 | |
2273 | #if DEBUG |
2274 | static void check_irq_off(void) |
2275 | { |
2276 | BUG_ON(!irqs_disabled()); |
2277 | } |
2278 | |
2279 | static void check_irq_on(void) |
2280 | { |
2281 | BUG_ON(irqs_disabled()); |
2282 | } |
2283 | |
2284 | static void check_spinlock_acquired(struct kmem_cache *cachep) |
2285 | { |
2286 | #ifdef CONFIG_SMP |
2287 | check_irq_off(); |
2288 | assert_spin_locked(&get_node(cachep, numa_mem_id())->list_lock); |
2289 | #endif |
2290 | } |
2291 | |
2292 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) |
2293 | { |
2294 | #ifdef CONFIG_SMP |
2295 | check_irq_off(); |
2296 | assert_spin_locked(&get_node(cachep, node)->list_lock); |
2297 | #endif |
2298 | } |
2299 | |
2300 | #else |
2301 | #define check_irq_off() do { } while(0) |
2302 | #define check_irq_on() do { } while(0) |
2303 | #define check_spinlock_acquired(x) do { } while(0) |
2304 | #define check_spinlock_acquired_node(x, y) do { } while(0) |
2305 | #endif |
2306 | |
2307 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
2308 | struct array_cache *ac, |
2309 | int force, int node); |
2310 | |
2311 | static void do_drain(void *arg) |
2312 | { |
2313 | struct kmem_cache *cachep = arg; |
2314 | struct array_cache *ac; |
2315 | int node = numa_mem_id(); |
2316 | struct kmem_cache_node *n; |
2317 | LIST_HEAD(list); |
2318 | |
2319 | check_irq_off(); |
2320 | ac = cpu_cache_get(cachep); |
2321 | n = get_node(cachep, node); |
2322 | spin_lock(&n->list_lock); |
2323 | free_block(cachep, ac->entry, ac->avail, node, &list); |
2324 | spin_unlock(&n->list_lock); |
2325 | slabs_destroy(cachep, &list); |
2326 | ac->avail = 0; |
2327 | } |
2328 | |
2329 | static void drain_cpu_caches(struct kmem_cache *cachep) |
2330 | { |
2331 | struct kmem_cache_node *n; |
2332 | int node; |
2333 | |
2334 | on_each_cpu(do_drain, cachep, 1); |
2335 | check_irq_on(); |
2336 | for_each_kmem_cache_node(cachep, node, n) |
2337 | if (n->alien) |
2338 | drain_alien_cache(cachep, n->alien); |
2339 | |
2340 | for_each_kmem_cache_node(cachep, node, n) |
2341 | drain_array(cachep, n, n->shared, 1, node); |
2342 | } |
2343 | |
2344 | /* |
2345 | * Remove slabs from the list of free slabs. |
2346 | * Specify the number of slabs to drain in tofree. |
2347 | * |
2348 | * Returns the actual number of slabs released. |
2349 | */ |
2350 | static int drain_freelist(struct kmem_cache *cache, |
2351 | struct kmem_cache_node *n, int tofree) |
2352 | { |
2353 | struct list_head *p; |
2354 | int nr_freed; |
2355 | struct page *page; |
2356 | |
2357 | nr_freed = 0; |
2358 | while (nr_freed < tofree && !list_empty(&n->slabs_free)) { |
2359 | |
2360 | spin_lock_irq(&n->list_lock); |
2361 | p = n->slabs_free.prev; |
2362 | if (p == &n->slabs_free) { |
2363 | spin_unlock_irq(&n->list_lock); |
2364 | goto out; |
2365 | } |
2366 | |
2367 | page = list_entry(p, struct page, lru); |
2368 | #if DEBUG |
2369 | BUG_ON(page->active); |
2370 | #endif |
2371 | list_del(&page->lru); |
2372 | /* |
2373 | * Safe to drop the lock. The slab is no longer linked |
2374 | * to the cache. |
2375 | */ |
2376 | n->free_objects -= cache->num; |
2377 | spin_unlock_irq(&n->list_lock); |
2378 | slab_destroy(cache, page); |
2379 | nr_freed++; |
2380 | } |
2381 | out: |
2382 | return nr_freed; |
2383 | } |
2384 | |
2385 | int __kmem_cache_shrink(struct kmem_cache *cachep) |
2386 | { |
2387 | int ret = 0; |
2388 | int node; |
2389 | struct kmem_cache_node *n; |
2390 | |
2391 | drain_cpu_caches(cachep); |
2392 | |
2393 | check_irq_on(); |
2394 | for_each_kmem_cache_node(cachep, node, n) { |
2395 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
2396 | |
2397 | ret += !list_empty(&n->slabs_full) || |
2398 | !list_empty(&n->slabs_partial); |
2399 | } |
2400 | return (ret ? 1 : 0); |
2401 | } |
2402 | |
2403 | int __kmem_cache_shutdown(struct kmem_cache *cachep) |
2404 | { |
2405 | int i; |
2406 | struct kmem_cache_node *n; |
2407 | int rc = __kmem_cache_shrink(cachep); |
2408 | |
2409 | if (rc) |
2410 | return rc; |
2411 | |
2412 | free_percpu(cachep->cpu_cache); |
2413 | |
2414 | /* NUMA: free the node structures */ |
2415 | for_each_kmem_cache_node(cachep, i, n) { |
2416 | kfree(n->shared); |
2417 | free_alien_cache(n->alien); |
2418 | kfree(n); |
2419 | cachep->node[i] = NULL; |
2420 | } |
2421 | return 0; |
2422 | } |
2423 | |
2424 | /* |
2425 | * Get the memory for a slab management obj. |
2426 | * |
2427 | * For a slab cache when the slab descriptor is off-slab, the |
2428 | * slab descriptor can't come from the same cache which is being created, |
2429 | * Because if it is the case, that means we defer the creation of |
2430 | * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point. |
2431 | * And we eventually call down to __kmem_cache_create(), which |
2432 | * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one. |
2433 | * This is a "chicken-and-egg" problem. |
2434 | * |
2435 | * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches, |
2436 | * which are all initialized during kmem_cache_init(). |
2437 | */ |
2438 | static void *alloc_slabmgmt(struct kmem_cache *cachep, |
2439 | struct page *page, int colour_off, |
2440 | gfp_t local_flags, int nodeid) |
2441 | { |
2442 | void *freelist; |
2443 | void *addr = page_address(page); |
2444 | |
2445 | if (OFF_SLAB(cachep)) { |
2446 | /* Slab management obj is off-slab. */ |
2447 | freelist = kmem_cache_alloc_node(cachep->freelist_cache, |
2448 | local_flags, nodeid); |
2449 | if (!freelist) |
2450 | return NULL; |
2451 | } else { |
2452 | freelist = addr + colour_off; |
2453 | colour_off += cachep->freelist_size; |
2454 | } |
2455 | page->active = 0; |
2456 | page->s_mem = addr + colour_off; |
2457 | return freelist; |
2458 | } |
2459 | |
2460 | static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx) |
2461 | { |
2462 | return ((freelist_idx_t *)page->freelist)[idx]; |
2463 | } |
2464 | |
2465 | static inline void set_free_obj(struct page *page, |
2466 | unsigned int idx, freelist_idx_t val) |
2467 | { |
2468 | ((freelist_idx_t *)(page->freelist))[idx] = val; |
2469 | } |
2470 | |
2471 | static void cache_init_objs(struct kmem_cache *cachep, |
2472 | struct page *page) |
2473 | { |
2474 | int i; |
2475 | |
2476 | for (i = 0; i < cachep->num; i++) { |
2477 | void *objp = index_to_obj(cachep, page, i); |
2478 | #if DEBUG |
2479 | /* need to poison the objs? */ |
2480 | if (cachep->flags & SLAB_POISON) |
2481 | poison_obj(cachep, objp, POISON_FREE); |
2482 | if (cachep->flags & SLAB_STORE_USER) |
2483 | *dbg_userword(cachep, objp) = NULL; |
2484 | |
2485 | if (cachep->flags & SLAB_RED_ZONE) { |
2486 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2487 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2488 | } |
2489 | /* |
2490 | * Constructors are not allowed to allocate memory from the same |
2491 | * cache which they are a constructor for. Otherwise, deadlock. |
2492 | * They must also be threaded. |
2493 | */ |
2494 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) |
2495 | cachep->ctor(objp + obj_offset(cachep)); |
2496 | |
2497 | if (cachep->flags & SLAB_RED_ZONE) { |
2498 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2499 | slab_error(cachep, "constructor overwrote the" |
2500 | " end of an object"); |
2501 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2502 | slab_error(cachep, "constructor overwrote the" |
2503 | " start of an object"); |
2504 | } |
2505 | if ((cachep->size % PAGE_SIZE) == 0 && |
2506 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
2507 | kernel_map_pages(virt_to_page(objp), |
2508 | cachep->size / PAGE_SIZE, 0); |
2509 | #else |
2510 | if (cachep->ctor) |
2511 | cachep->ctor(objp); |
2512 | #endif |
2513 | set_obj_status(page, i, OBJECT_FREE); |
2514 | set_free_obj(page, i, i); |
2515 | } |
2516 | } |
2517 | |
2518 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) |
2519 | { |
2520 | if (CONFIG_ZONE_DMA_FLAG) { |
2521 | if (flags & GFP_DMA) |
2522 | BUG_ON(!(cachep->allocflags & GFP_DMA)); |
2523 | else |
2524 | BUG_ON(cachep->allocflags & GFP_DMA); |
2525 | } |
2526 | } |
2527 | |
2528 | static void *slab_get_obj(struct kmem_cache *cachep, struct page *page, |
2529 | int nodeid) |
2530 | { |
2531 | void *objp; |
2532 | |
2533 | objp = index_to_obj(cachep, page, get_free_obj(page, page->active)); |
2534 | page->active++; |
2535 | #if DEBUG |
2536 | WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); |
2537 | #endif |
2538 | |
2539 | return objp; |
2540 | } |
2541 | |
2542 | static void slab_put_obj(struct kmem_cache *cachep, struct page *page, |
2543 | void *objp, int nodeid) |
2544 | { |
2545 | unsigned int objnr = obj_to_index(cachep, page, objp); |
2546 | #if DEBUG |
2547 | unsigned int i; |
2548 | |
2549 | /* Verify that the slab belongs to the intended node */ |
2550 | WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); |
2551 | |
2552 | /* Verify double free bug */ |
2553 | for (i = page->active; i < cachep->num; i++) { |
2554 | if (get_free_obj(page, i) == objnr) { |
2555 | printk(KERN_ERR "slab: double free detected in cache " |
2556 | "'%s', objp %p\n", cachep->name, objp); |
2557 | BUG(); |
2558 | } |
2559 | } |
2560 | #endif |
2561 | page->active--; |
2562 | set_free_obj(page, page->active, objnr); |
2563 | } |
2564 | |
2565 | /* |
2566 | * Map pages beginning at addr to the given cache and slab. This is required |
2567 | * for the slab allocator to be able to lookup the cache and slab of a |
2568 | * virtual address for kfree, ksize, and slab debugging. |
2569 | */ |
2570 | static void slab_map_pages(struct kmem_cache *cache, struct page *page, |
2571 | void *freelist) |
2572 | { |
2573 | page->slab_cache = cache; |
2574 | page->freelist = freelist; |
2575 | } |
2576 | |
2577 | /* |
2578 | * Grow (by 1) the number of slabs within a cache. This is called by |
2579 | * kmem_cache_alloc() when there are no active objs left in a cache. |
2580 | */ |
2581 | static int cache_grow(struct kmem_cache *cachep, |
2582 | gfp_t flags, int nodeid, struct page *page) |
2583 | { |
2584 | void *freelist; |
2585 | size_t offset; |
2586 | gfp_t local_flags; |
2587 | struct kmem_cache_node *n; |
2588 | |
2589 | /* |
2590 | * Be lazy and only check for valid flags here, keeping it out of the |
2591 | * critical path in kmem_cache_alloc(). |
2592 | */ |
2593 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
2594 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
2595 | |
2596 | /* Take the node list lock to change the colour_next on this node */ |
2597 | check_irq_off(); |
2598 | n = get_node(cachep, nodeid); |
2599 | spin_lock(&n->list_lock); |
2600 | |
2601 | /* Get colour for the slab, and cal the next value. */ |
2602 | offset = n->colour_next; |
2603 | n->colour_next++; |
2604 | if (n->colour_next >= cachep->colour) |
2605 | n->colour_next = 0; |
2606 | spin_unlock(&n->list_lock); |
2607 | |
2608 | offset *= cachep->colour_off; |
2609 | |
2610 | if (local_flags & __GFP_WAIT) |
2611 | local_irq_enable(); |
2612 | |
2613 | /* |
2614 | * The test for missing atomic flag is performed here, rather than |
2615 | * the more obvious place, simply to reduce the critical path length |
2616 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they |
2617 | * will eventually be caught here (where it matters). |
2618 | */ |
2619 | kmem_flagcheck(cachep, flags); |
2620 | |
2621 | /* |
2622 | * Get mem for the objs. Attempt to allocate a physical page from |
2623 | * 'nodeid'. |
2624 | */ |
2625 | if (!page) |
2626 | page = kmem_getpages(cachep, local_flags, nodeid); |
2627 | if (!page) |
2628 | goto failed; |
2629 | |
2630 | /* Get slab management. */ |
2631 | freelist = alloc_slabmgmt(cachep, page, offset, |
2632 | local_flags & ~GFP_CONSTRAINT_MASK, nodeid); |
2633 | if (!freelist) |
2634 | goto opps1; |
2635 | |
2636 | slab_map_pages(cachep, page, freelist); |
2637 | |
2638 | cache_init_objs(cachep, page); |
2639 | |
2640 | if (local_flags & __GFP_WAIT) |
2641 | local_irq_disable(); |
2642 | check_irq_off(); |
2643 | spin_lock(&n->list_lock); |
2644 | |
2645 | /* Make slab active. */ |
2646 | list_add_tail(&page->lru, &(n->slabs_free)); |
2647 | STATS_INC_GROWN(cachep); |
2648 | n->free_objects += cachep->num; |
2649 | spin_unlock(&n->list_lock); |
2650 | return 1; |
2651 | opps1: |
2652 | kmem_freepages(cachep, page); |
2653 | failed: |
2654 | if (local_flags & __GFP_WAIT) |
2655 | local_irq_disable(); |
2656 | return 0; |
2657 | } |
2658 | |
2659 | #if DEBUG |
2660 | |
2661 | /* |
2662 | * Perform extra freeing checks: |
2663 | * - detect bad pointers. |
2664 | * - POISON/RED_ZONE checking |
2665 | */ |
2666 | static void kfree_debugcheck(const void *objp) |
2667 | { |
2668 | if (!virt_addr_valid(objp)) { |
2669 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
2670 | (unsigned long)objp); |
2671 | BUG(); |
2672 | } |
2673 | } |
2674 | |
2675 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) |
2676 | { |
2677 | unsigned long long redzone1, redzone2; |
2678 | |
2679 | redzone1 = *dbg_redzone1(cache, obj); |
2680 | redzone2 = *dbg_redzone2(cache, obj); |
2681 | |
2682 | /* |
2683 | * Redzone is ok. |
2684 | */ |
2685 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) |
2686 | return; |
2687 | |
2688 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) |
2689 | slab_error(cache, "double free detected"); |
2690 | else |
2691 | slab_error(cache, "memory outside object was overwritten"); |
2692 | |
2693 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", |
2694 | obj, redzone1, redzone2); |
2695 | } |
2696 | |
2697 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, |
2698 | unsigned long caller) |
2699 | { |
2700 | unsigned int objnr; |
2701 | struct page *page; |
2702 | |
2703 | BUG_ON(virt_to_cache(objp) != cachep); |
2704 | |
2705 | objp -= obj_offset(cachep); |
2706 | kfree_debugcheck(objp); |
2707 | page = virt_to_head_page(objp); |
2708 | |
2709 | if (cachep->flags & SLAB_RED_ZONE) { |
2710 | verify_redzone_free(cachep, objp); |
2711 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2712 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2713 | } |
2714 | if (cachep->flags & SLAB_STORE_USER) |
2715 | *dbg_userword(cachep, objp) = (void *)caller; |
2716 | |
2717 | objnr = obj_to_index(cachep, page, objp); |
2718 | |
2719 | BUG_ON(objnr >= cachep->num); |
2720 | BUG_ON(objp != index_to_obj(cachep, page, objnr)); |
2721 | |
2722 | set_obj_status(page, objnr, OBJECT_FREE); |
2723 | if (cachep->flags & SLAB_POISON) { |
2724 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2725 | if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { |
2726 | store_stackinfo(cachep, objp, caller); |
2727 | kernel_map_pages(virt_to_page(objp), |
2728 | cachep->size / PAGE_SIZE, 0); |
2729 | } else { |
2730 | poison_obj(cachep, objp, POISON_FREE); |
2731 | } |
2732 | #else |
2733 | poison_obj(cachep, objp, POISON_FREE); |
2734 | #endif |
2735 | } |
2736 | return objp; |
2737 | } |
2738 | |
2739 | #else |
2740 | #define kfree_debugcheck(x) do { } while(0) |
2741 | #define cache_free_debugcheck(x,objp,z) (objp) |
2742 | #endif |
2743 | |
2744 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, |
2745 | bool force_refill) |
2746 | { |
2747 | int batchcount; |
2748 | struct kmem_cache_node *n; |
2749 | struct array_cache *ac; |
2750 | int node; |
2751 | |
2752 | check_irq_off(); |
2753 | node = numa_mem_id(); |
2754 | if (unlikely(force_refill)) |
2755 | goto force_grow; |
2756 | retry: |
2757 | ac = cpu_cache_get(cachep); |
2758 | batchcount = ac->batchcount; |
2759 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
2760 | /* |
2761 | * If there was little recent activity on this cache, then |
2762 | * perform only a partial refill. Otherwise we could generate |
2763 | * refill bouncing. |
2764 | */ |
2765 | batchcount = BATCHREFILL_LIMIT; |
2766 | } |
2767 | n = get_node(cachep, node); |
2768 | |
2769 | BUG_ON(ac->avail > 0 || !n); |
2770 | spin_lock(&n->list_lock); |
2771 | |
2772 | /* See if we can refill from the shared array */ |
2773 | if (n->shared && transfer_objects(ac, n->shared, batchcount)) { |
2774 | n->shared->touched = 1; |
2775 | goto alloc_done; |
2776 | } |
2777 | |
2778 | while (batchcount > 0) { |
2779 | struct list_head *entry; |
2780 | struct page *page; |
2781 | /* Get slab alloc is to come from. */ |
2782 | entry = n->slabs_partial.next; |
2783 | if (entry == &n->slabs_partial) { |
2784 | n->free_touched = 1; |
2785 | entry = n->slabs_free.next; |
2786 | if (entry == &n->slabs_free) |
2787 | goto must_grow; |
2788 | } |
2789 | |
2790 | page = list_entry(entry, struct page, lru); |
2791 | check_spinlock_acquired(cachep); |
2792 | |
2793 | /* |
2794 | * The slab was either on partial or free list so |
2795 | * there must be at least one object available for |
2796 | * allocation. |
2797 | */ |
2798 | BUG_ON(page->active >= cachep->num); |
2799 | |
2800 | while (page->active < cachep->num && batchcount--) { |
2801 | STATS_INC_ALLOCED(cachep); |
2802 | STATS_INC_ACTIVE(cachep); |
2803 | STATS_SET_HIGH(cachep); |
2804 | |
2805 | ac_put_obj(cachep, ac, slab_get_obj(cachep, page, |
2806 | node)); |
2807 | } |
2808 | |
2809 | /* move slabp to correct slabp list: */ |
2810 | list_del(&page->lru); |
2811 | if (page->active == cachep->num) |
2812 | list_add(&page->lru, &n->slabs_full); |
2813 | else |
2814 | list_add(&page->lru, &n->slabs_partial); |
2815 | } |
2816 | |
2817 | must_grow: |
2818 | n->free_objects -= ac->avail; |
2819 | alloc_done: |
2820 | spin_unlock(&n->list_lock); |
2821 | |
2822 | if (unlikely(!ac->avail)) { |
2823 | int x; |
2824 | force_grow: |
2825 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); |
2826 | |
2827 | /* cache_grow can reenable interrupts, then ac could change. */ |
2828 | ac = cpu_cache_get(cachep); |
2829 | node = numa_mem_id(); |
2830 | |
2831 | /* no objects in sight? abort */ |
2832 | if (!x && (ac->avail == 0 || force_refill)) |
2833 | return NULL; |
2834 | |
2835 | if (!ac->avail) /* objects refilled by interrupt? */ |
2836 | goto retry; |
2837 | } |
2838 | ac->touched = 1; |
2839 | |
2840 | return ac_get_obj(cachep, ac, flags, force_refill); |
2841 | } |
2842 | |
2843 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, |
2844 | gfp_t flags) |
2845 | { |
2846 | might_sleep_if(flags & __GFP_WAIT); |
2847 | #if DEBUG |
2848 | kmem_flagcheck(cachep, flags); |
2849 | #endif |
2850 | } |
2851 | |
2852 | #if DEBUG |
2853 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, |
2854 | gfp_t flags, void *objp, unsigned long caller) |
2855 | { |
2856 | struct page *page; |
2857 | |
2858 | if (!objp) |
2859 | return objp; |
2860 | if (cachep->flags & SLAB_POISON) { |
2861 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2862 | if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
2863 | kernel_map_pages(virt_to_page(objp), |
2864 | cachep->size / PAGE_SIZE, 1); |
2865 | else |
2866 | check_poison_obj(cachep, objp); |
2867 | #else |
2868 | check_poison_obj(cachep, objp); |
2869 | #endif |
2870 | poison_obj(cachep, objp, POISON_INUSE); |
2871 | } |
2872 | if (cachep->flags & SLAB_STORE_USER) |
2873 | *dbg_userword(cachep, objp) = (void *)caller; |
2874 | |
2875 | if (cachep->flags & SLAB_RED_ZONE) { |
2876 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || |
2877 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
2878 | slab_error(cachep, "double free, or memory outside" |
2879 | " object was overwritten"); |
2880 | printk(KERN_ERR |
2881 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", |
2882 | objp, *dbg_redzone1(cachep, objp), |
2883 | *dbg_redzone2(cachep, objp)); |
2884 | } |
2885 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
2886 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
2887 | } |
2888 | |
2889 | page = virt_to_head_page(objp); |
2890 | set_obj_status(page, obj_to_index(cachep, page, objp), OBJECT_ACTIVE); |
2891 | objp += obj_offset(cachep); |
2892 | if (cachep->ctor && cachep->flags & SLAB_POISON) |
2893 | cachep->ctor(objp); |
2894 | if (ARCH_SLAB_MINALIGN && |
2895 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { |
2896 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", |
2897 | objp, (int)ARCH_SLAB_MINALIGN); |
2898 | } |
2899 | return objp; |
2900 | } |
2901 | #else |
2902 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
2903 | #endif |
2904 | |
2905 | static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) |
2906 | { |
2907 | if (unlikely(cachep == kmem_cache)) |
2908 | return false; |
2909 | |
2910 | return should_failslab(cachep->object_size, flags, cachep->flags); |
2911 | } |
2912 | |
2913 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
2914 | { |
2915 | void *objp; |
2916 | struct array_cache *ac; |
2917 | bool force_refill = false; |
2918 | |
2919 | check_irq_off(); |
2920 | |
2921 | ac = cpu_cache_get(cachep); |
2922 | if (likely(ac->avail)) { |
2923 | ac->touched = 1; |
2924 | objp = ac_get_obj(cachep, ac, flags, false); |
2925 | |
2926 | /* |
2927 | * Allow for the possibility all avail objects are not allowed |
2928 | * by the current flags |
2929 | */ |
2930 | if (objp) { |
2931 | STATS_INC_ALLOCHIT(cachep); |
2932 | goto out; |
2933 | } |
2934 | force_refill = true; |
2935 | } |
2936 | |
2937 | STATS_INC_ALLOCMISS(cachep); |
2938 | objp = cache_alloc_refill(cachep, flags, force_refill); |
2939 | /* |
2940 | * the 'ac' may be updated by cache_alloc_refill(), |
2941 | * and kmemleak_erase() requires its correct value. |
2942 | */ |
2943 | ac = cpu_cache_get(cachep); |
2944 | |
2945 | out: |
2946 | /* |
2947 | * To avoid a false negative, if an object that is in one of the |
2948 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't |
2949 | * treat the array pointers as a reference to the object. |
2950 | */ |
2951 | if (objp) |
2952 | kmemleak_erase(&ac->entry[ac->avail]); |
2953 | return objp; |
2954 | } |
2955 | |
2956 | #ifdef CONFIG_NUMA |
2957 | /* |
2958 | * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set. |
2959 | * |
2960 | * If we are in_interrupt, then process context, including cpusets and |
2961 | * mempolicy, may not apply and should not be used for allocation policy. |
2962 | */ |
2963 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) |
2964 | { |
2965 | int nid_alloc, nid_here; |
2966 | |
2967 | if (in_interrupt() || (flags & __GFP_THISNODE)) |
2968 | return NULL; |
2969 | nid_alloc = nid_here = numa_mem_id(); |
2970 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) |
2971 | nid_alloc = cpuset_slab_spread_node(); |
2972 | else if (current->mempolicy) |
2973 | nid_alloc = mempolicy_slab_node(); |
2974 | if (nid_alloc != nid_here) |
2975 | return ____cache_alloc_node(cachep, flags, nid_alloc); |
2976 | return NULL; |
2977 | } |
2978 | |
2979 | /* |
2980 | * Fallback function if there was no memory available and no objects on a |
2981 | * certain node and fall back is permitted. First we scan all the |
2982 | * available node for available objects. If that fails then we |
2983 | * perform an allocation without specifying a node. This allows the page |
2984 | * allocator to do its reclaim / fallback magic. We then insert the |
2985 | * slab into the proper nodelist and then allocate from it. |
2986 | */ |
2987 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) |
2988 | { |
2989 | struct zonelist *zonelist; |
2990 | gfp_t local_flags; |
2991 | struct zoneref *z; |
2992 | struct zone *zone; |
2993 | enum zone_type high_zoneidx = gfp_zone(flags); |
2994 | void *obj = NULL; |
2995 | int nid; |
2996 | unsigned int cpuset_mems_cookie; |
2997 | |
2998 | if (flags & __GFP_THISNODE) |
2999 | return NULL; |
3000 | |
3001 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
3002 | |
3003 | retry_cpuset: |
3004 | cpuset_mems_cookie = read_mems_allowed_begin(); |
3005 | zonelist = node_zonelist(mempolicy_slab_node(), flags); |
3006 | |
3007 | retry: |
3008 | /* |
3009 | * Look through allowed nodes for objects available |
3010 | * from existing per node queues. |
3011 | */ |
3012 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
3013 | nid = zone_to_nid(zone); |
3014 | |
3015 | if (cpuset_zone_allowed_hardwall(zone, flags) && |
3016 | get_node(cache, nid) && |
3017 | get_node(cache, nid)->free_objects) { |
3018 | obj = ____cache_alloc_node(cache, |
3019 | flags | GFP_THISNODE, nid); |
3020 | if (obj) |
3021 | break; |
3022 | } |
3023 | } |
3024 | |
3025 | if (!obj) { |
3026 | /* |
3027 | * This allocation will be performed within the constraints |
3028 | * of the current cpuset / memory policy requirements. |
3029 | * We may trigger various forms of reclaim on the allowed |
3030 | * set and go into memory reserves if necessary. |
3031 | */ |
3032 | struct page *page; |
3033 | |
3034 | if (local_flags & __GFP_WAIT) |
3035 | local_irq_enable(); |
3036 | kmem_flagcheck(cache, flags); |
3037 | page = kmem_getpages(cache, local_flags, numa_mem_id()); |
3038 | if (local_flags & __GFP_WAIT) |
3039 | local_irq_disable(); |
3040 | if (page) { |
3041 | /* |
3042 | * Insert into the appropriate per node queues |
3043 | */ |
3044 | nid = page_to_nid(page); |
3045 | if (cache_grow(cache, flags, nid, page)) { |
3046 | obj = ____cache_alloc_node(cache, |
3047 | flags | GFP_THISNODE, nid); |
3048 | if (!obj) |
3049 | /* |
3050 | * Another processor may allocate the |
3051 | * objects in the slab since we are |
3052 | * not holding any locks. |
3053 | */ |
3054 | goto retry; |
3055 | } else { |
3056 | /* cache_grow already freed obj */ |
3057 | obj = NULL; |
3058 | } |
3059 | } |
3060 | } |
3061 | |
3062 | if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie))) |
3063 | goto retry_cpuset; |
3064 | return obj; |
3065 | } |
3066 | |
3067 | /* |
3068 | * A interface to enable slab creation on nodeid |
3069 | */ |
3070 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, |
3071 | int nodeid) |
3072 | { |
3073 | struct list_head *entry; |
3074 | struct page *page; |
3075 | struct kmem_cache_node *n; |
3076 | void *obj; |
3077 | int x; |
3078 | |
3079 | VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES); |
3080 | n = get_node(cachep, nodeid); |
3081 | BUG_ON(!n); |
3082 | |
3083 | retry: |
3084 | check_irq_off(); |
3085 | spin_lock(&n->list_lock); |
3086 | entry = n->slabs_partial.next; |
3087 | if (entry == &n->slabs_partial) { |
3088 | n->free_touched = 1; |
3089 | entry = n->slabs_free.next; |
3090 | if (entry == &n->slabs_free) |
3091 | goto must_grow; |
3092 | } |
3093 | |
3094 | page = list_entry(entry, struct page, lru); |
3095 | check_spinlock_acquired_node(cachep, nodeid); |
3096 | |
3097 | STATS_INC_NODEALLOCS(cachep); |
3098 | STATS_INC_ACTIVE(cachep); |
3099 | STATS_SET_HIGH(cachep); |
3100 | |
3101 | BUG_ON(page->active == cachep->num); |
3102 | |
3103 | obj = slab_get_obj(cachep, page, nodeid); |
3104 | n->free_objects--; |
3105 | /* move slabp to correct slabp list: */ |
3106 | list_del(&page->lru); |
3107 | |
3108 | if (page->active == cachep->num) |
3109 | list_add(&page->lru, &n->slabs_full); |
3110 | else |
3111 | list_add(&page->lru, &n->slabs_partial); |
3112 | |
3113 | spin_unlock(&n->list_lock); |
3114 | goto done; |
3115 | |
3116 | must_grow: |
3117 | spin_unlock(&n->list_lock); |
3118 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); |
3119 | if (x) |
3120 | goto retry; |
3121 | |
3122 | return fallback_alloc(cachep, flags); |
3123 | |
3124 | done: |
3125 | return obj; |
3126 | } |
3127 | |
3128 | static __always_inline void * |
3129 | slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, |
3130 | unsigned long caller) |
3131 | { |
3132 | unsigned long save_flags; |
3133 | void *ptr; |
3134 | int slab_node = numa_mem_id(); |
3135 | |
3136 | flags &= gfp_allowed_mask; |
3137 | |
3138 | lockdep_trace_alloc(flags); |
3139 | |
3140 | if (slab_should_failslab(cachep, flags)) |
3141 | return NULL; |
3142 | |
3143 | cachep = memcg_kmem_get_cache(cachep, flags); |
3144 | |
3145 | cache_alloc_debugcheck_before(cachep, flags); |
3146 | local_irq_save(save_flags); |
3147 | |
3148 | if (nodeid == NUMA_NO_NODE) |
3149 | nodeid = slab_node; |
3150 | |
3151 | if (unlikely(!get_node(cachep, nodeid))) { |
3152 | /* Node not bootstrapped yet */ |
3153 | ptr = fallback_alloc(cachep, flags); |
3154 | goto out; |
3155 | } |
3156 | |
3157 | if (nodeid == slab_node) { |
3158 | /* |
3159 | * Use the locally cached objects if possible. |
3160 | * However ____cache_alloc does not allow fallback |
3161 | * to other nodes. It may fail while we still have |
3162 | * objects on other nodes available. |
3163 | */ |
3164 | ptr = ____cache_alloc(cachep, flags); |
3165 | if (ptr) |
3166 | goto out; |
3167 | } |
3168 | /* ___cache_alloc_node can fall back to other nodes */ |
3169 | ptr = ____cache_alloc_node(cachep, flags, nodeid); |
3170 | out: |
3171 | local_irq_restore(save_flags); |
3172 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
3173 | kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, |
3174 | flags); |
3175 | |
3176 | if (likely(ptr)) { |
3177 | kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); |
3178 | if (unlikely(flags & __GFP_ZERO)) |
3179 | memset(ptr, 0, cachep->object_size); |
3180 | } |
3181 | |
3182 | return ptr; |
3183 | } |
3184 | |
3185 | static __always_inline void * |
3186 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) |
3187 | { |
3188 | void *objp; |
3189 | |
3190 | if (current->mempolicy || cpuset_do_slab_mem_spread()) { |
3191 | objp = alternate_node_alloc(cache, flags); |
3192 | if (objp) |
3193 | goto out; |
3194 | } |
3195 | objp = ____cache_alloc(cache, flags); |
3196 | |
3197 | /* |
3198 | * We may just have run out of memory on the local node. |
3199 | * ____cache_alloc_node() knows how to locate memory on other nodes |
3200 | */ |
3201 | if (!objp) |
3202 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); |
3203 | |
3204 | out: |
3205 | return objp; |
3206 | } |
3207 | #else |
3208 | |
3209 | static __always_inline void * |
3210 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3211 | { |
3212 | return ____cache_alloc(cachep, flags); |
3213 | } |
3214 | |
3215 | #endif /* CONFIG_NUMA */ |
3216 | |
3217 | static __always_inline void * |
3218 | slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) |
3219 | { |
3220 | unsigned long save_flags; |
3221 | void *objp; |
3222 | |
3223 | flags &= gfp_allowed_mask; |
3224 | |
3225 | lockdep_trace_alloc(flags); |
3226 | |
3227 | if (slab_should_failslab(cachep, flags)) |
3228 | return NULL; |
3229 | |
3230 | cachep = memcg_kmem_get_cache(cachep, flags); |
3231 | |
3232 | cache_alloc_debugcheck_before(cachep, flags); |
3233 | local_irq_save(save_flags); |
3234 | objp = __do_cache_alloc(cachep, flags); |
3235 | local_irq_restore(save_flags); |
3236 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
3237 | kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, |
3238 | flags); |
3239 | prefetchw(objp); |
3240 | |
3241 | if (likely(objp)) { |
3242 | kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); |
3243 | if (unlikely(flags & __GFP_ZERO)) |
3244 | memset(objp, 0, cachep->object_size); |
3245 | } |
3246 | |
3247 | return objp; |
3248 | } |
3249 | |
3250 | /* |
3251 | * Caller needs to acquire correct kmem_cache_node's list_lock |
3252 | * @list: List of detached free slabs should be freed by caller |
3253 | */ |
3254 | static void free_block(struct kmem_cache *cachep, void **objpp, |
3255 | int nr_objects, int node, struct list_head *list) |
3256 | { |
3257 | int i; |
3258 | struct kmem_cache_node *n = get_node(cachep, node); |
3259 | |
3260 | for (i = 0; i < nr_objects; i++) { |
3261 | void *objp; |
3262 | struct page *page; |
3263 | |
3264 | clear_obj_pfmemalloc(&objpp[i]); |
3265 | objp = objpp[i]; |
3266 | |
3267 | page = virt_to_head_page(objp); |
3268 | list_del(&page->lru); |
3269 | check_spinlock_acquired_node(cachep, node); |
3270 | slab_put_obj(cachep, page, objp, node); |
3271 | STATS_DEC_ACTIVE(cachep); |
3272 | n->free_objects++; |
3273 | |
3274 | /* fixup slab chains */ |
3275 | if (page->active == 0) { |
3276 | if (n->free_objects > n->free_limit) { |
3277 | n->free_objects -= cachep->num; |
3278 | list_add_tail(&page->lru, list); |
3279 | } else { |
3280 | list_add(&page->lru, &n->slabs_free); |
3281 | } |
3282 | } else { |
3283 | /* Unconditionally move a slab to the end of the |
3284 | * partial list on free - maximum time for the |
3285 | * other objects to be freed, too. |
3286 | */ |
3287 | list_add_tail(&page->lru, &n->slabs_partial); |
3288 | } |
3289 | } |
3290 | } |
3291 | |
3292 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) |
3293 | { |
3294 | int batchcount; |
3295 | struct kmem_cache_node *n; |
3296 | int node = numa_mem_id(); |
3297 | LIST_HEAD(list); |
3298 | |
3299 | batchcount = ac->batchcount; |
3300 | #if DEBUG |
3301 | BUG_ON(!batchcount || batchcount > ac->avail); |
3302 | #endif |
3303 | check_irq_off(); |
3304 | n = get_node(cachep, node); |
3305 | spin_lock(&n->list_lock); |
3306 | if (n->shared) { |
3307 | struct array_cache *shared_array = n->shared; |
3308 | int max = shared_array->limit - shared_array->avail; |
3309 | if (max) { |
3310 | if (batchcount > max) |
3311 | batchcount = max; |
3312 | memcpy(&(shared_array->entry[shared_array->avail]), |
3313 | ac->entry, sizeof(void *) * batchcount); |
3314 | shared_array->avail += batchcount; |
3315 | goto free_done; |
3316 | } |
3317 | } |
3318 | |
3319 | free_block(cachep, ac->entry, batchcount, node, &list); |
3320 | free_done: |
3321 | #if STATS |
3322 | { |
3323 | int i = 0; |
3324 | struct list_head *p; |
3325 | |
3326 | p = n->slabs_free.next; |
3327 | while (p != &(n->slabs_free)) { |
3328 | struct page *page; |
3329 | |
3330 | page = list_entry(p, struct page, lru); |
3331 | BUG_ON(page->active); |
3332 | |
3333 | i++; |
3334 | p = p->next; |
3335 | } |
3336 | STATS_SET_FREEABLE(cachep, i); |
3337 | } |
3338 | #endif |
3339 | spin_unlock(&n->list_lock); |
3340 | slabs_destroy(cachep, &list); |
3341 | ac->avail -= batchcount; |
3342 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); |
3343 | } |
3344 | |
3345 | /* |
3346 | * Release an obj back to its cache. If the obj has a constructed state, it must |
3347 | * be in this state _before_ it is released. Called with disabled ints. |
3348 | */ |
3349 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, |
3350 | unsigned long caller) |
3351 | { |
3352 | struct array_cache *ac = cpu_cache_get(cachep); |
3353 | |
3354 | check_irq_off(); |
3355 | kmemleak_free_recursive(objp, cachep->flags); |
3356 | objp = cache_free_debugcheck(cachep, objp, caller); |
3357 | |
3358 | kmemcheck_slab_free(cachep, objp, cachep->object_size); |
3359 | |
3360 | /* |
3361 | * Skip calling cache_free_alien() when the platform is not numa. |
3362 | * This will avoid cache misses that happen while accessing slabp (which |
3363 | * is per page memory reference) to get nodeid. Instead use a global |
3364 | * variable to skip the call, which is mostly likely to be present in |
3365 | * the cache. |
3366 | */ |
3367 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) |
3368 | return; |
3369 | |
3370 | if (ac->avail < ac->limit) { |
3371 | STATS_INC_FREEHIT(cachep); |
3372 | } else { |
3373 | STATS_INC_FREEMISS(cachep); |
3374 | cache_flusharray(cachep, ac); |
3375 | } |
3376 | |
3377 | ac_put_obj(cachep, ac, objp); |
3378 | } |
3379 | |
3380 | /** |
3381 | * kmem_cache_alloc - Allocate an object |
3382 | * @cachep: The cache to allocate from. |
3383 | * @flags: See kmalloc(). |
3384 | * |
3385 | * Allocate an object from this cache. The flags are only relevant |
3386 | * if the cache has no available objects. |
3387 | */ |
3388 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3389 | { |
3390 | void *ret = slab_alloc(cachep, flags, _RET_IP_); |
3391 | |
3392 | trace_kmem_cache_alloc(_RET_IP_, ret, |
3393 | cachep->object_size, cachep->size, flags); |
3394 | |
3395 | return ret; |
3396 | } |
3397 | EXPORT_SYMBOL(kmem_cache_alloc); |
3398 | |
3399 | #ifdef CONFIG_TRACING |
3400 | void * |
3401 | kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) |
3402 | { |
3403 | void *ret; |
3404 | |
3405 | ret = slab_alloc(cachep, flags, _RET_IP_); |
3406 | |
3407 | trace_kmalloc(_RET_IP_, ret, |
3408 | size, cachep->size, flags); |
3409 | return ret; |
3410 | } |
3411 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
3412 | #endif |
3413 | |
3414 | #ifdef CONFIG_NUMA |
3415 | /** |
3416 | * kmem_cache_alloc_node - Allocate an object on the specified node |
3417 | * @cachep: The cache to allocate from. |
3418 | * @flags: See kmalloc(). |
3419 | * @nodeid: node number of the target node. |
3420 | * |
3421 | * Identical to kmem_cache_alloc but it will allocate memory on the given |
3422 | * node, which can improve the performance for cpu bound structures. |
3423 | * |
3424 | * Fallback to other node is possible if __GFP_THISNODE is not set. |
3425 | */ |
3426 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
3427 | { |
3428 | void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3429 | |
3430 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
3431 | cachep->object_size, cachep->size, |
3432 | flags, nodeid); |
3433 | |
3434 | return ret; |
3435 | } |
3436 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
3437 | |
3438 | #ifdef CONFIG_TRACING |
3439 | void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, |
3440 | gfp_t flags, |
3441 | int nodeid, |
3442 | size_t size) |
3443 | { |
3444 | void *ret; |
3445 | |
3446 | ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3447 | |
3448 | trace_kmalloc_node(_RET_IP_, ret, |
3449 | size, cachep->size, |
3450 | flags, nodeid); |
3451 | return ret; |
3452 | } |
3453 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
3454 | #endif |
3455 | |
3456 | static __always_inline void * |
3457 | __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) |
3458 | { |
3459 | struct kmem_cache *cachep; |
3460 | |
3461 | cachep = kmalloc_slab(size, flags); |
3462 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3463 | return cachep; |
3464 | return kmem_cache_alloc_node_trace(cachep, flags, node, size); |
3465 | } |
3466 | |
3467 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3468 | { |
3469 | return __do_kmalloc_node(size, flags, node, _RET_IP_); |
3470 | } |
3471 | EXPORT_SYMBOL(__kmalloc_node); |
3472 | |
3473 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, |
3474 | int node, unsigned long caller) |
3475 | { |
3476 | return __do_kmalloc_node(size, flags, node, caller); |
3477 | } |
3478 | EXPORT_SYMBOL(__kmalloc_node_track_caller); |
3479 | #endif /* CONFIG_NUMA */ |
3480 | |
3481 | /** |
3482 | * __do_kmalloc - allocate memory |
3483 | * @size: how many bytes of memory are required. |
3484 | * @flags: the type of memory to allocate (see kmalloc). |
3485 | * @caller: function caller for debug tracking of the caller |
3486 | */ |
3487 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, |
3488 | unsigned long caller) |
3489 | { |
3490 | struct kmem_cache *cachep; |
3491 | void *ret; |
3492 | |
3493 | cachep = kmalloc_slab(size, flags); |
3494 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3495 | return cachep; |
3496 | ret = slab_alloc(cachep, flags, caller); |
3497 | |
3498 | trace_kmalloc(caller, ret, |
3499 | size, cachep->size, flags); |
3500 | |
3501 | return ret; |
3502 | } |
3503 | |
3504 | void *__kmalloc(size_t size, gfp_t flags) |
3505 | { |
3506 | return __do_kmalloc(size, flags, _RET_IP_); |
3507 | } |
3508 | EXPORT_SYMBOL(__kmalloc); |
3509 | |
3510 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) |
3511 | { |
3512 | return __do_kmalloc(size, flags, caller); |
3513 | } |
3514 | EXPORT_SYMBOL(__kmalloc_track_caller); |
3515 | |
3516 | /** |
3517 | * kmem_cache_free - Deallocate an object |
3518 | * @cachep: The cache the allocation was from. |
3519 | * @objp: The previously allocated object. |
3520 | * |
3521 | * Free an object which was previously allocated from this |
3522 | * cache. |
3523 | */ |
3524 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) |
3525 | { |
3526 | unsigned long flags; |
3527 | cachep = cache_from_obj(cachep, objp); |
3528 | if (!cachep) |
3529 | return; |
3530 | |
3531 | local_irq_save(flags); |
3532 | debug_check_no_locks_freed(objp, cachep->object_size); |
3533 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) |
3534 | debug_check_no_obj_freed(objp, cachep->object_size); |
3535 | __cache_free(cachep, objp, _RET_IP_); |
3536 | local_irq_restore(flags); |
3537 | |
3538 | trace_kmem_cache_free(_RET_IP_, objp); |
3539 | } |
3540 | EXPORT_SYMBOL(kmem_cache_free); |
3541 | |
3542 | /** |
3543 | * kfree - free previously allocated memory |
3544 | * @objp: pointer returned by kmalloc. |
3545 | * |
3546 | * If @objp is NULL, no operation is performed. |
3547 | * |
3548 | * Don't free memory not originally allocated by kmalloc() |
3549 | * or you will run into trouble. |
3550 | */ |
3551 | void kfree(const void *objp) |
3552 | { |
3553 | struct kmem_cache *c; |
3554 | unsigned long flags; |
3555 | |
3556 | trace_kfree(_RET_IP_, objp); |
3557 | |
3558 | if (unlikely(ZERO_OR_NULL_PTR(objp))) |
3559 | return; |
3560 | local_irq_save(flags); |
3561 | kfree_debugcheck(objp); |
3562 | c = virt_to_cache(objp); |
3563 | debug_check_no_locks_freed(objp, c->object_size); |
3564 | |
3565 | debug_check_no_obj_freed(objp, c->object_size); |
3566 | __cache_free(c, (void *)objp, _RET_IP_); |
3567 | local_irq_restore(flags); |
3568 | } |
3569 | EXPORT_SYMBOL(kfree); |
3570 | |
3571 | /* |
3572 | * This initializes kmem_cache_node or resizes various caches for all nodes. |
3573 | */ |
3574 | static int alloc_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp) |
3575 | { |
3576 | int node; |
3577 | struct kmem_cache_node *n; |
3578 | struct array_cache *new_shared; |
3579 | struct alien_cache **new_alien = NULL; |
3580 | |
3581 | for_each_online_node(node) { |
3582 | |
3583 | if (use_alien_caches) { |
3584 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); |
3585 | if (!new_alien) |
3586 | goto fail; |
3587 | } |
3588 | |
3589 | new_shared = NULL; |
3590 | if (cachep->shared) { |
3591 | new_shared = alloc_arraycache(node, |
3592 | cachep->shared*cachep->batchcount, |
3593 | 0xbaadf00d, gfp); |
3594 | if (!new_shared) { |
3595 | free_alien_cache(new_alien); |
3596 | goto fail; |
3597 | } |
3598 | } |
3599 | |
3600 | n = get_node(cachep, node); |
3601 | if (n) { |
3602 | struct array_cache *shared = n->shared; |
3603 | LIST_HEAD(list); |
3604 | |
3605 | spin_lock_irq(&n->list_lock); |
3606 | |
3607 | if (shared) |
3608 | free_block(cachep, shared->entry, |
3609 | shared->avail, node, &list); |
3610 | |
3611 | n->shared = new_shared; |
3612 | if (!n->alien) { |
3613 | n->alien = new_alien; |
3614 | new_alien = NULL; |
3615 | } |
3616 | n->free_limit = (1 + nr_cpus_node(node)) * |
3617 | cachep->batchcount + cachep->num; |
3618 | spin_unlock_irq(&n->list_lock); |
3619 | slabs_destroy(cachep, &list); |
3620 | kfree(shared); |
3621 | free_alien_cache(new_alien); |
3622 | continue; |
3623 | } |
3624 | n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); |
3625 | if (!n) { |
3626 | free_alien_cache(new_alien); |
3627 | kfree(new_shared); |
3628 | goto fail; |
3629 | } |
3630 | |
3631 | kmem_cache_node_init(n); |
3632 | n->next_reap = jiffies + REAPTIMEOUT_NODE + |
3633 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
3634 | n->shared = new_shared; |
3635 | n->alien = new_alien; |
3636 | n->free_limit = (1 + nr_cpus_node(node)) * |
3637 | cachep->batchcount + cachep->num; |
3638 | cachep->node[node] = n; |
3639 | } |
3640 | return 0; |
3641 | |
3642 | fail: |
3643 | if (!cachep->list.next) { |
3644 | /* Cache is not active yet. Roll back what we did */ |
3645 | node--; |
3646 | while (node >= 0) { |
3647 | n = get_node(cachep, node); |
3648 | if (n) { |
3649 | kfree(n->shared); |
3650 | free_alien_cache(n->alien); |
3651 | kfree(n); |
3652 | cachep->node[node] = NULL; |
3653 | } |
3654 | node--; |
3655 | } |
3656 | } |
3657 | return -ENOMEM; |
3658 | } |
3659 | |
3660 | /* Always called with the slab_mutex held */ |
3661 | static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3662 | int batchcount, int shared, gfp_t gfp) |
3663 | { |
3664 | struct array_cache __percpu *cpu_cache, *prev; |
3665 | int cpu; |
3666 | |
3667 | cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount); |
3668 | if (!cpu_cache) |
3669 | return -ENOMEM; |
3670 | |
3671 | prev = cachep->cpu_cache; |
3672 | cachep->cpu_cache = cpu_cache; |
3673 | kick_all_cpus_sync(); |
3674 | |
3675 | check_irq_on(); |
3676 | cachep->batchcount = batchcount; |
3677 | cachep->limit = limit; |
3678 | cachep->shared = shared; |
3679 | |
3680 | if (!prev) |
3681 | goto alloc_node; |
3682 | |
3683 | for_each_online_cpu(cpu) { |
3684 | LIST_HEAD(list); |
3685 | int node; |
3686 | struct kmem_cache_node *n; |
3687 | struct array_cache *ac = per_cpu_ptr(prev, cpu); |
3688 | |
3689 | node = cpu_to_mem(cpu); |
3690 | n = get_node(cachep, node); |
3691 | spin_lock_irq(&n->list_lock); |
3692 | free_block(cachep, ac->entry, ac->avail, node, &list); |
3693 | spin_unlock_irq(&n->list_lock); |
3694 | slabs_destroy(cachep, &list); |
3695 | } |
3696 | free_percpu(prev); |
3697 | |
3698 | alloc_node: |
3699 | return alloc_kmem_cache_node(cachep, gfp); |
3700 | } |
3701 | |
3702 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3703 | int batchcount, int shared, gfp_t gfp) |
3704 | { |
3705 | int ret; |
3706 | struct kmem_cache *c = NULL; |
3707 | int i = 0; |
3708 | |
3709 | ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
3710 | |
3711 | if (slab_state < FULL) |
3712 | return ret; |
3713 | |
3714 | if ((ret < 0) || !is_root_cache(cachep)) |
3715 | return ret; |
3716 | |
3717 | VM_BUG_ON(!mutex_is_locked(&slab_mutex)); |
3718 | for_each_memcg_cache_index(i) { |
3719 | c = cache_from_memcg_idx(cachep, i); |
3720 | if (c) |
3721 | /* return value determined by the parent cache only */ |
3722 | __do_tune_cpucache(c, limit, batchcount, shared, gfp); |
3723 | } |
3724 | |
3725 | return ret; |
3726 | } |
3727 | |
3728 | /* Called with slab_mutex held always */ |
3729 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) |
3730 | { |
3731 | int err; |
3732 | int limit = 0; |
3733 | int shared = 0; |
3734 | int batchcount = 0; |
3735 | |
3736 | if (!is_root_cache(cachep)) { |
3737 | struct kmem_cache *root = memcg_root_cache(cachep); |
3738 | limit = root->limit; |
3739 | shared = root->shared; |
3740 | batchcount = root->batchcount; |
3741 | } |
3742 | |
3743 | if (limit && shared && batchcount) |
3744 | goto skip_setup; |
3745 | /* |
3746 | * The head array serves three purposes: |
3747 | * - create a LIFO ordering, i.e. return objects that are cache-warm |
3748 | * - reduce the number of spinlock operations. |
3749 | * - reduce the number of linked list operations on the slab and |
3750 | * bufctl chains: array operations are cheaper. |
3751 | * The numbers are guessed, we should auto-tune as described by |
3752 | * Bonwick. |
3753 | */ |
3754 | if (cachep->size > 131072) |
3755 | limit = 1; |
3756 | else if (cachep->size > PAGE_SIZE) |
3757 | limit = 8; |
3758 | else if (cachep->size > 1024) |
3759 | limit = 24; |
3760 | else if (cachep->size > 256) |
3761 | limit = 54; |
3762 | else |
3763 | limit = 120; |
3764 | |
3765 | /* |
3766 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound |
3767 | * allocation behaviour: Most allocs on one cpu, most free operations |
3768 | * on another cpu. For these cases, an efficient object passing between |
3769 | * cpus is necessary. This is provided by a shared array. The array |
3770 | * replaces Bonwick's magazine layer. |
3771 | * On uniprocessor, it's functionally equivalent (but less efficient) |
3772 | * to a larger limit. Thus disabled by default. |
3773 | */ |
3774 | shared = 0; |
3775 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) |
3776 | shared = 8; |
3777 | |
3778 | #if DEBUG |
3779 | /* |
3780 | * With debugging enabled, large batchcount lead to excessively long |
3781 | * periods with disabled local interrupts. Limit the batchcount |
3782 | */ |
3783 | if (limit > 32) |
3784 | limit = 32; |
3785 | #endif |
3786 | batchcount = (limit + 1) / 2; |
3787 | skip_setup: |
3788 | err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
3789 | if (err) |
3790 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", |
3791 | cachep->name, -err); |
3792 | return err; |
3793 | } |
3794 | |
3795 | /* |
3796 | * Drain an array if it contains any elements taking the node lock only if |
3797 | * necessary. Note that the node listlock also protects the array_cache |
3798 | * if drain_array() is used on the shared array. |
3799 | */ |
3800 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
3801 | struct array_cache *ac, int force, int node) |
3802 | { |
3803 | LIST_HEAD(list); |
3804 | int tofree; |
3805 | |
3806 | if (!ac || !ac->avail) |
3807 | return; |
3808 | if (ac->touched && !force) { |
3809 | ac->touched = 0; |
3810 | } else { |
3811 | spin_lock_irq(&n->list_lock); |
3812 | if (ac->avail) { |
3813 | tofree = force ? ac->avail : (ac->limit + 4) / 5; |
3814 | if (tofree > ac->avail) |
3815 | tofree = (ac->avail + 1) / 2; |
3816 | free_block(cachep, ac->entry, tofree, node, &list); |
3817 | ac->avail -= tofree; |
3818 | memmove(ac->entry, &(ac->entry[tofree]), |
3819 | sizeof(void *) * ac->avail); |
3820 | } |
3821 | spin_unlock_irq(&n->list_lock); |
3822 | slabs_destroy(cachep, &list); |
3823 | } |
3824 | } |
3825 | |
3826 | /** |
3827 | * cache_reap - Reclaim memory from caches. |
3828 | * @w: work descriptor |
3829 | * |
3830 | * Called from workqueue/eventd every few seconds. |
3831 | * Purpose: |
3832 | * - clear the per-cpu caches for this CPU. |
3833 | * - return freeable pages to the main free memory pool. |
3834 | * |
3835 | * If we cannot acquire the cache chain mutex then just give up - we'll try |
3836 | * again on the next iteration. |
3837 | */ |
3838 | static void cache_reap(struct work_struct *w) |
3839 | { |
3840 | struct kmem_cache *searchp; |
3841 | struct kmem_cache_node *n; |
3842 | int node = numa_mem_id(); |
3843 | struct delayed_work *work = to_delayed_work(w); |
3844 | |
3845 | if (!mutex_trylock(&slab_mutex)) |
3846 | /* Give up. Setup the next iteration. */ |
3847 | goto out; |
3848 | |
3849 | list_for_each_entry(searchp, &slab_caches, list) { |
3850 | check_irq_on(); |
3851 | |
3852 | /* |
3853 | * We only take the node lock if absolutely necessary and we |
3854 | * have established with reasonable certainty that |
3855 | * we can do some work if the lock was obtained. |
3856 | */ |
3857 | n = get_node(searchp, node); |
3858 | |
3859 | reap_alien(searchp, n); |
3860 | |
3861 | drain_array(searchp, n, cpu_cache_get(searchp), 0, node); |
3862 | |
3863 | /* |
3864 | * These are racy checks but it does not matter |
3865 | * if we skip one check or scan twice. |
3866 | */ |
3867 | if (time_after(n->next_reap, jiffies)) |
3868 | goto next; |
3869 | |
3870 | n->next_reap = jiffies + REAPTIMEOUT_NODE; |
3871 | |
3872 | drain_array(searchp, n, n->shared, 0, node); |
3873 | |
3874 | if (n->free_touched) |
3875 | n->free_touched = 0; |
3876 | else { |
3877 | int freed; |
3878 | |
3879 | freed = drain_freelist(searchp, n, (n->free_limit + |
3880 | 5 * searchp->num - 1) / (5 * searchp->num)); |
3881 | STATS_ADD_REAPED(searchp, freed); |
3882 | } |
3883 | next: |
3884 | cond_resched(); |
3885 | } |
3886 | check_irq_on(); |
3887 | mutex_unlock(&slab_mutex); |
3888 | next_reap_node(); |
3889 | out: |
3890 | /* Set up the next iteration */ |
3891 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC)); |
3892 | } |
3893 | |
3894 | #ifdef CONFIG_SLABINFO |
3895 | void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) |
3896 | { |
3897 | struct page *page; |
3898 | unsigned long active_objs; |
3899 | unsigned long num_objs; |
3900 | unsigned long active_slabs = 0; |
3901 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; |
3902 | const char *name; |
3903 | char *error = NULL; |
3904 | int node; |
3905 | struct kmem_cache_node *n; |
3906 | |
3907 | active_objs = 0; |
3908 | num_slabs = 0; |
3909 | for_each_kmem_cache_node(cachep, node, n) { |
3910 | |
3911 | check_irq_on(); |
3912 | spin_lock_irq(&n->list_lock); |
3913 | |
3914 | list_for_each_entry(page, &n->slabs_full, lru) { |
3915 | if (page->active != cachep->num && !error) |
3916 | error = "slabs_full accounting error"; |
3917 | active_objs += cachep->num; |
3918 | active_slabs++; |
3919 | } |
3920 | list_for_each_entry(page, &n->slabs_partial, lru) { |
3921 | if (page->active == cachep->num && !error) |
3922 | error = "slabs_partial accounting error"; |
3923 | if (!page->active && !error) |
3924 | error = "slabs_partial accounting error"; |
3925 | active_objs += page->active; |
3926 | active_slabs++; |
3927 | } |
3928 | list_for_each_entry(page, &n->slabs_free, lru) { |
3929 | if (page->active && !error) |
3930 | error = "slabs_free accounting error"; |
3931 | num_slabs++; |
3932 | } |
3933 | free_objects += n->free_objects; |
3934 | if (n->shared) |
3935 | shared_avail += n->shared->avail; |
3936 | |
3937 | spin_unlock_irq(&n->list_lock); |
3938 | } |
3939 | num_slabs += active_slabs; |
3940 | num_objs = num_slabs * cachep->num; |
3941 | if (num_objs - active_objs != free_objects && !error) |
3942 | error = "free_objects accounting error"; |
3943 | |
3944 | name = cachep->name; |
3945 | if (error) |
3946 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); |
3947 | |
3948 | sinfo->active_objs = active_objs; |
3949 | sinfo->num_objs = num_objs; |
3950 | sinfo->active_slabs = active_slabs; |
3951 | sinfo->num_slabs = num_slabs; |
3952 | sinfo->shared_avail = shared_avail; |
3953 | sinfo->limit = cachep->limit; |
3954 | sinfo->batchcount = cachep->batchcount; |
3955 | sinfo->shared = cachep->shared; |
3956 | sinfo->objects_per_slab = cachep->num; |
3957 | sinfo->cache_order = cachep->gfporder; |
3958 | } |
3959 | |
3960 | void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) |
3961 | { |
3962 | #if STATS |
3963 | { /* node stats */ |
3964 | unsigned long high = cachep->high_mark; |
3965 | unsigned long allocs = cachep->num_allocations; |
3966 | unsigned long grown = cachep->grown; |
3967 | unsigned long reaped = cachep->reaped; |
3968 | unsigned long errors = cachep->errors; |
3969 | unsigned long max_freeable = cachep->max_freeable; |
3970 | unsigned long node_allocs = cachep->node_allocs; |
3971 | unsigned long node_frees = cachep->node_frees; |
3972 | unsigned long overflows = cachep->node_overflow; |
3973 | |
3974 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " |
3975 | "%4lu %4lu %4lu %4lu %4lu", |
3976 | allocs, high, grown, |
3977 | reaped, errors, max_freeable, node_allocs, |
3978 | node_frees, overflows); |
3979 | } |
3980 | /* cpu stats */ |
3981 | { |
3982 | unsigned long allochit = atomic_read(&cachep->allochit); |
3983 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
3984 | unsigned long freehit = atomic_read(&cachep->freehit); |
3985 | unsigned long freemiss = atomic_read(&cachep->freemiss); |
3986 | |
3987 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
3988 | allochit, allocmiss, freehit, freemiss); |
3989 | } |
3990 | #endif |
3991 | } |
3992 | |
3993 | #define MAX_SLABINFO_WRITE 128 |
3994 | /** |
3995 | * slabinfo_write - Tuning for the slab allocator |
3996 | * @file: unused |
3997 | * @buffer: user buffer |
3998 | * @count: data length |
3999 | * @ppos: unused |
4000 | */ |
4001 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
4002 | size_t count, loff_t *ppos) |
4003 | { |
4004 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; |
4005 | int limit, batchcount, shared, res; |
4006 | struct kmem_cache *cachep; |
4007 | |
4008 | if (count > MAX_SLABINFO_WRITE) |
4009 | return -EINVAL; |
4010 | if (copy_from_user(&kbuf, buffer, count)) |
4011 | return -EFAULT; |
4012 | kbuf[MAX_SLABINFO_WRITE] = '\0'; |
4013 | |
4014 | tmp = strchr(kbuf, ' '); |
4015 | if (!tmp) |
4016 | return -EINVAL; |
4017 | *tmp = '\0'; |
4018 | tmp++; |
4019 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
4020 | return -EINVAL; |
4021 | |
4022 | /* Find the cache in the chain of caches. */ |
4023 | mutex_lock(&slab_mutex); |
4024 | res = -EINVAL; |
4025 | list_for_each_entry(cachep, &slab_caches, list) { |
4026 | if (!strcmp(cachep->name, kbuf)) { |
4027 | if (limit < 1 || batchcount < 1 || |
4028 | batchcount > limit || shared < 0) { |
4029 | res = 0; |
4030 | } else { |
4031 | res = do_tune_cpucache(cachep, limit, |
4032 | batchcount, shared, |
4033 | GFP_KERNEL); |
4034 | } |
4035 | break; |
4036 | } |
4037 | } |
4038 | mutex_unlock(&slab_mutex); |
4039 | if (res >= 0) |
4040 | res = count; |
4041 | return res; |
4042 | } |
4043 | |
4044 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4045 | |
4046 | static void *leaks_start(struct seq_file *m, loff_t *pos) |
4047 | { |
4048 | mutex_lock(&slab_mutex); |
4049 | return seq_list_start(&slab_caches, *pos); |
4050 | } |
4051 | |
4052 | static inline int add_caller(unsigned long *n, unsigned long v) |
4053 | { |
4054 | unsigned long *p; |
4055 | int l; |
4056 | if (!v) |
4057 | return 1; |
4058 | l = n[1]; |
4059 | p = n + 2; |
4060 | while (l) { |
4061 | int i = l/2; |
4062 | unsigned long *q = p + 2 * i; |
4063 | if (*q == v) { |
4064 | q[1]++; |
4065 | return 1; |
4066 | } |
4067 | if (*q > v) { |
4068 | l = i; |
4069 | } else { |
4070 | p = q + 2; |
4071 | l -= i + 1; |
4072 | } |
4073 | } |
4074 | if (++n[1] == n[0]) |
4075 | return 0; |
4076 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); |
4077 | p[0] = v; |
4078 | p[1] = 1; |
4079 | return 1; |
4080 | } |
4081 | |
4082 | static void handle_slab(unsigned long *n, struct kmem_cache *c, |
4083 | struct page *page) |
4084 | { |
4085 | void *p; |
4086 | int i; |
4087 | |
4088 | if (n[0] == n[1]) |
4089 | return; |
4090 | for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) { |
4091 | if (get_obj_status(page, i) != OBJECT_ACTIVE) |
4092 | continue; |
4093 | |
4094 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) |
4095 | return; |
4096 | } |
4097 | } |
4098 | |
4099 | static void show_symbol(struct seq_file *m, unsigned long address) |
4100 | { |
4101 | #ifdef CONFIG_KALLSYMS |
4102 | unsigned long offset, size; |
4103 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; |
4104 | |
4105 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { |
4106 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); |
4107 | if (modname[0]) |
4108 | seq_printf(m, " [%s]", modname); |
4109 | return; |
4110 | } |
4111 | #endif |
4112 | seq_printf(m, "%p", (void *)address); |
4113 | } |
4114 | |
4115 | static int leaks_show(struct seq_file *m, void *p) |
4116 | { |
4117 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); |
4118 | struct page *page; |
4119 | struct kmem_cache_node *n; |
4120 | const char *name; |
4121 | unsigned long *x = m->private; |
4122 | int node; |
4123 | int i; |
4124 | |
4125 | if (!(cachep->flags & SLAB_STORE_USER)) |
4126 | return 0; |
4127 | if (!(cachep->flags & SLAB_RED_ZONE)) |
4128 | return 0; |
4129 | |
4130 | /* OK, we can do it */ |
4131 | |
4132 | x[1] = 0; |
4133 | |
4134 | for_each_kmem_cache_node(cachep, node, n) { |
4135 | |
4136 | check_irq_on(); |
4137 | spin_lock_irq(&n->list_lock); |
4138 | |
4139 | list_for_each_entry(page, &n->slabs_full, lru) |
4140 | handle_slab(x, cachep, page); |
4141 | list_for_each_entry(page, &n->slabs_partial, lru) |
4142 | handle_slab(x, cachep, page); |
4143 | spin_unlock_irq(&n->list_lock); |
4144 | } |
4145 | name = cachep->name; |
4146 | if (x[0] == x[1]) { |
4147 | /* Increase the buffer size */ |
4148 | mutex_unlock(&slab_mutex); |
4149 | m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL); |
4150 | if (!m->private) { |
4151 | /* Too bad, we are really out */ |
4152 | m->private = x; |
4153 | mutex_lock(&slab_mutex); |
4154 | return -ENOMEM; |
4155 | } |
4156 | *(unsigned long *)m->private = x[0] * 2; |
4157 | kfree(x); |
4158 | mutex_lock(&slab_mutex); |
4159 | /* Now make sure this entry will be retried */ |
4160 | m->count = m->size; |
4161 | return 0; |
4162 | } |
4163 | for (i = 0; i < x[1]; i++) { |
4164 | seq_printf(m, "%s: %lu ", name, x[2*i+3]); |
4165 | show_symbol(m, x[2*i+2]); |
4166 | seq_putc(m, '\n'); |
4167 | } |
4168 | |
4169 | return 0; |
4170 | } |
4171 | |
4172 | static const struct seq_operations slabstats_op = { |
4173 | .start = leaks_start, |
4174 | .next = slab_next, |
4175 | .stop = slab_stop, |
4176 | .show = leaks_show, |
4177 | }; |
4178 | |
4179 | static int slabstats_open(struct inode *inode, struct file *file) |
4180 | { |
4181 | unsigned long *n; |
4182 | |
4183 | n = __seq_open_private(file, &slabstats_op, PAGE_SIZE); |
4184 | if (!n) |
4185 | return -ENOMEM; |
4186 | |
4187 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); |
4188 | |
4189 | return 0; |
4190 | } |
4191 | |
4192 | static const struct file_operations proc_slabstats_operations = { |
4193 | .open = slabstats_open, |
4194 | .read = seq_read, |
4195 | .llseek = seq_lseek, |
4196 | .release = seq_release_private, |
4197 | }; |
4198 | #endif |
4199 | |
4200 | static int __init slab_proc_init(void) |
4201 | { |
4202 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4203 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); |
4204 | #endif |
4205 | return 0; |
4206 | } |
4207 | module_init(slab_proc_init); |
4208 | #endif |
4209 | |
4210 | /** |
4211 | * ksize - get the actual amount of memory allocated for a given object |
4212 | * @objp: Pointer to the object |
4213 | * |
4214 | * kmalloc may internally round up allocations and return more memory |
4215 | * than requested. ksize() can be used to determine the actual amount of |
4216 | * memory allocated. The caller may use this additional memory, even though |
4217 | * a smaller amount of memory was initially specified with the kmalloc call. |
4218 | * The caller must guarantee that objp points to a valid object previously |
4219 | * allocated with either kmalloc() or kmem_cache_alloc(). The object |
4220 | * must not be freed during the duration of the call. |
4221 | */ |
4222 | size_t ksize(const void *objp) |
4223 | { |
4224 | BUG_ON(!objp); |
4225 | if (unlikely(objp == ZERO_SIZE_PTR)) |
4226 | return 0; |
4227 | |
4228 | return virt_to_cache(objp)->object_size; |
4229 | } |
4230 | EXPORT_SYMBOL(ksize); |
4231 |
Branches:
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javiroman/ks7010
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9