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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 | spinlock_t lock; | |
195 | void *entry[]; /* | |
196 | * Must have this definition in here for the proper | |
197 | * alignment of array_cache. Also simplifies accessing | |
198 | * the entries. | |
199 | * | |
200 | * Entries should not be directly dereferenced as | |
201 | * entries belonging to slabs marked pfmemalloc will | |
202 | * have the lower bits set SLAB_OBJ_PFMEMALLOC | |
203 | */ | |
204 | }; | |
205 | ||
206 | #define SLAB_OBJ_PFMEMALLOC 1 | |
207 | static inline bool is_obj_pfmemalloc(void *objp) | |
208 | { | |
209 | return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; | |
210 | } | |
211 | ||
212 | static inline void set_obj_pfmemalloc(void **objp) | |
213 | { | |
214 | *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); | |
215 | return; | |
216 | } | |
217 | ||
218 | static inline void clear_obj_pfmemalloc(void **objp) | |
219 | { | |
220 | *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); | |
221 | } | |
222 | ||
223 | /* | |
224 | * bootstrap: The caches do not work without cpuarrays anymore, but the | |
225 | * cpuarrays are allocated from the generic caches... | |
226 | */ | |
227 | #define BOOT_CPUCACHE_ENTRIES 1 | |
228 | struct arraycache_init { | |
229 | struct array_cache cache; | |
230 | void *entries[BOOT_CPUCACHE_ENTRIES]; | |
231 | }; | |
232 | ||
233 | /* | |
234 | * Need this for bootstrapping a per node allocator. | |
235 | */ | |
236 | #define NUM_INIT_LISTS (3 * MAX_NUMNODES) | |
237 | static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; | |
238 | #define CACHE_CACHE 0 | |
239 | #define SIZE_AC MAX_NUMNODES | |
240 | #define SIZE_NODE (2 * MAX_NUMNODES) | |
241 | ||
242 | static int drain_freelist(struct kmem_cache *cache, | |
243 | struct kmem_cache_node *n, int tofree); | |
244 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, | |
245 | int node); | |
246 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); | |
247 | static void cache_reap(struct work_struct *unused); | |
248 | ||
249 | static int slab_early_init = 1; | |
250 | ||
251 | #define INDEX_AC kmalloc_index(sizeof(struct arraycache_init)) | |
252 | #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) | |
253 | ||
254 | static void kmem_cache_node_init(struct kmem_cache_node *parent) | |
255 | { | |
256 | INIT_LIST_HEAD(&parent->slabs_full); | |
257 | INIT_LIST_HEAD(&parent->slabs_partial); | |
258 | INIT_LIST_HEAD(&parent->slabs_free); | |
259 | parent->shared = NULL; | |
260 | parent->alien = NULL; | |
261 | parent->colour_next = 0; | |
262 | spin_lock_init(&parent->list_lock); | |
263 | parent->free_objects = 0; | |
264 | parent->free_touched = 0; | |
265 | } | |
266 | ||
267 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ | |
268 | do { \ | |
269 | INIT_LIST_HEAD(listp); \ | |
270 | list_splice(&(cachep->node[nodeid]->slab), listp); \ | |
271 | } while (0) | |
272 | ||
273 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ | |
274 | do { \ | |
275 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ | |
276 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ | |
277 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ | |
278 | } while (0) | |
279 | ||
280 | #define CFLGS_OFF_SLAB (0x80000000UL) | |
281 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) | |
282 | ||
283 | #define BATCHREFILL_LIMIT 16 | |
284 | /* | |
285 | * Optimization question: fewer reaps means less probability for unnessary | |
286 | * cpucache drain/refill cycles. | |
287 | * | |
288 | * OTOH the cpuarrays can contain lots of objects, | |
289 | * which could lock up otherwise freeable slabs. | |
290 | */ | |
291 | #define REAPTIMEOUT_AC (2*HZ) | |
292 | #define REAPTIMEOUT_NODE (4*HZ) | |
293 | ||
294 | #if STATS | |
295 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) | |
296 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) | |
297 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) | |
298 | #define STATS_INC_GROWN(x) ((x)->grown++) | |
299 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) | |
300 | #define STATS_SET_HIGH(x) \ | |
301 | do { \ | |
302 | if ((x)->num_active > (x)->high_mark) \ | |
303 | (x)->high_mark = (x)->num_active; \ | |
304 | } while (0) | |
305 | #define STATS_INC_ERR(x) ((x)->errors++) | |
306 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) | |
307 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) | |
308 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) | |
309 | #define STATS_SET_FREEABLE(x, i) \ | |
310 | do { \ | |
311 | if ((x)->max_freeable < i) \ | |
312 | (x)->max_freeable = i; \ | |
313 | } while (0) | |
314 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) | |
315 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) | |
316 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) | |
317 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) | |
318 | #else | |
319 | #define STATS_INC_ACTIVE(x) do { } while (0) | |
320 | #define STATS_DEC_ACTIVE(x) do { } while (0) | |
321 | #define STATS_INC_ALLOCED(x) do { } while (0) | |
322 | #define STATS_INC_GROWN(x) do { } while (0) | |
323 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) | |
324 | #define STATS_SET_HIGH(x) do { } while (0) | |
325 | #define STATS_INC_ERR(x) do { } while (0) | |
326 | #define STATS_INC_NODEALLOCS(x) do { } while (0) | |
327 | #define STATS_INC_NODEFREES(x) do { } while (0) | |
328 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) | |
329 | #define STATS_SET_FREEABLE(x, i) do { } while (0) | |
330 | #define STATS_INC_ALLOCHIT(x) do { } while (0) | |
331 | #define STATS_INC_ALLOCMISS(x) do { } while (0) | |
332 | #define STATS_INC_FREEHIT(x) do { } while (0) | |
333 | #define STATS_INC_FREEMISS(x) do { } while (0) | |
334 | #endif | |
335 | ||
336 | #if DEBUG | |
337 | ||
338 | /* | |
339 | * memory layout of objects: | |
340 | * 0 : objp | |
341 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that | |
342 | * the end of an object is aligned with the end of the real | |
343 | * allocation. Catches writes behind the end of the allocation. | |
344 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: | |
345 | * redzone word. | |
346 | * cachep->obj_offset: The real object. | |
347 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] | |
348 | * cachep->size - 1* BYTES_PER_WORD: last caller address | |
349 | * [BYTES_PER_WORD long] | |
350 | */ | |
351 | static int obj_offset(struct kmem_cache *cachep) | |
352 | { | |
353 | return cachep->obj_offset; | |
354 | } | |
355 | ||
356 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) | |
357 | { | |
358 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
359 | return (unsigned long long*) (objp + obj_offset(cachep) - | |
360 | sizeof(unsigned long long)); | |
361 | } | |
362 | ||
363 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) | |
364 | { | |
365 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
366 | if (cachep->flags & SLAB_STORE_USER) | |
367 | return (unsigned long long *)(objp + cachep->size - | |
368 | sizeof(unsigned long long) - | |
369 | REDZONE_ALIGN); | |
370 | return (unsigned long long *) (objp + cachep->size - | |
371 | sizeof(unsigned long long)); | |
372 | } | |
373 | ||
374 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) | |
375 | { | |
376 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); | |
377 | return (void **)(objp + cachep->size - BYTES_PER_WORD); | |
378 | } | |
379 | ||
380 | #else | |
381 | ||
382 | #define obj_offset(x) 0 | |
383 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
384 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
385 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) | |
386 | ||
387 | #endif | |
388 | ||
389 | /* | |
390 | * Do not go above this order unless 0 objects fit into the slab or | |
391 | * overridden on the command line. | |
392 | */ | |
393 | #define SLAB_MAX_ORDER_HI 1 | |
394 | #define SLAB_MAX_ORDER_LO 0 | |
395 | static int slab_max_order = SLAB_MAX_ORDER_LO; | |
396 | static bool slab_max_order_set __initdata; | |
397 | ||
398 | static inline struct kmem_cache *virt_to_cache(const void *obj) | |
399 | { | |
400 | struct page *page = virt_to_head_page(obj); | |
401 | return page->slab_cache; | |
402 | } | |
403 | ||
404 | static inline void *index_to_obj(struct kmem_cache *cache, struct page *page, | |
405 | unsigned int idx) | |
406 | { | |
407 | return page->s_mem + cache->size * idx; | |
408 | } | |
409 | ||
410 | /* | |
411 | * We want to avoid an expensive divide : (offset / cache->size) | |
412 | * Using the fact that size is a constant for a particular cache, | |
413 | * we can replace (offset / cache->size) by | |
414 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) | |
415 | */ | |
416 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, | |
417 | const struct page *page, void *obj) | |
418 | { | |
419 | u32 offset = (obj - page->s_mem); | |
420 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); | |
421 | } | |
422 | ||
423 | static struct arraycache_init initarray_generic = | |
424 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; | |
425 | ||
426 | /* internal cache of cache description objs */ | |
427 | static struct kmem_cache kmem_cache_boot = { | |
428 | .batchcount = 1, | |
429 | .limit = BOOT_CPUCACHE_ENTRIES, | |
430 | .shared = 1, | |
431 | .size = sizeof(struct kmem_cache), | |
432 | .name = "kmem_cache", | |
433 | }; | |
434 | ||
435 | #define BAD_ALIEN_MAGIC 0x01020304ul | |
436 | ||
437 | #ifdef CONFIG_LOCKDEP | |
438 | ||
439 | /* | |
440 | * Slab sometimes uses the kmalloc slabs to store the slab headers | |
441 | * for other slabs "off slab". | |
442 | * The locking for this is tricky in that it nests within the locks | |
443 | * of all other slabs in a few places; to deal with this special | |
444 | * locking we put on-slab caches into a separate lock-class. | |
445 | * | |
446 | * We set lock class for alien array caches which are up during init. | |
447 | * The lock annotation will be lost if all cpus of a node goes down and | |
448 | * then comes back up during hotplug | |
449 | */ | |
450 | static struct lock_class_key on_slab_l3_key; | |
451 | static struct lock_class_key on_slab_alc_key; | |
452 | ||
453 | static struct lock_class_key debugobj_l3_key; | |
454 | static struct lock_class_key debugobj_alc_key; | |
455 | ||
456 | static void slab_set_lock_classes(struct kmem_cache *cachep, | |
457 | struct lock_class_key *l3_key, struct lock_class_key *alc_key, | |
458 | int q) | |
459 | { | |
460 | struct array_cache **alc; | |
461 | struct kmem_cache_node *n; | |
462 | int r; | |
463 | ||
464 | n = cachep->node[q]; | |
465 | if (!n) | |
466 | return; | |
467 | ||
468 | lockdep_set_class(&n->list_lock, l3_key); | |
469 | alc = n->alien; | |
470 | /* | |
471 | * FIXME: This check for BAD_ALIEN_MAGIC | |
472 | * should go away when common slab code is taught to | |
473 | * work even without alien caches. | |
474 | * Currently, non NUMA code returns BAD_ALIEN_MAGIC | |
475 | * for alloc_alien_cache, | |
476 | */ | |
477 | if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) | |
478 | return; | |
479 | for_each_node(r) { | |
480 | if (alc[r]) | |
481 | lockdep_set_class(&alc[r]->lock, alc_key); | |
482 | } | |
483 | } | |
484 | ||
485 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) | |
486 | { | |
487 | slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node); | |
488 | } | |
489 | ||
490 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) | |
491 | { | |
492 | int node; | |
493 | ||
494 | for_each_online_node(node) | |
495 | slab_set_debugobj_lock_classes_node(cachep, node); | |
496 | } | |
497 | ||
498 | static void init_node_lock_keys(int q) | |
499 | { | |
500 | int i; | |
501 | ||
502 | if (slab_state < UP) | |
503 | return; | |
504 | ||
505 | for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) { | |
506 | struct kmem_cache_node *n; | |
507 | struct kmem_cache *cache = kmalloc_caches[i]; | |
508 | ||
509 | if (!cache) | |
510 | continue; | |
511 | ||
512 | n = cache->node[q]; | |
513 | if (!n || OFF_SLAB(cache)) | |
514 | continue; | |
515 | ||
516 | slab_set_lock_classes(cache, &on_slab_l3_key, | |
517 | &on_slab_alc_key, q); | |
518 | } | |
519 | } | |
520 | ||
521 | static void on_slab_lock_classes_node(struct kmem_cache *cachep, int q) | |
522 | { | |
523 | if (!cachep->node[q]) | |
524 | return; | |
525 | ||
526 | slab_set_lock_classes(cachep, &on_slab_l3_key, | |
527 | &on_slab_alc_key, q); | |
528 | } | |
529 | ||
530 | static inline void on_slab_lock_classes(struct kmem_cache *cachep) | |
531 | { | |
532 | int node; | |
533 | ||
534 | VM_BUG_ON(OFF_SLAB(cachep)); | |
535 | for_each_node(node) | |
536 | on_slab_lock_classes_node(cachep, node); | |
537 | } | |
538 | ||
539 | static inline void init_lock_keys(void) | |
540 | { | |
541 | int node; | |
542 | ||
543 | for_each_node(node) | |
544 | init_node_lock_keys(node); | |
545 | } | |
546 | #else | |
547 | static void init_node_lock_keys(int q) | |
548 | { | |
549 | } | |
550 | ||
551 | static inline void init_lock_keys(void) | |
552 | { | |
553 | } | |
554 | ||
555 | static inline void on_slab_lock_classes(struct kmem_cache *cachep) | |
556 | { | |
557 | } | |
558 | ||
559 | static inline void on_slab_lock_classes_node(struct kmem_cache *cachep, int node) | |
560 | { | |
561 | } | |
562 | ||
563 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) | |
564 | { | |
565 | } | |
566 | ||
567 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) | |
568 | { | |
569 | } | |
570 | #endif | |
571 | ||
572 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); | |
573 | ||
574 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) | |
575 | { | |
576 | return cachep->array[smp_processor_id()]; | |
577 | } | |
578 | ||
579 | static int calculate_nr_objs(size_t slab_size, size_t buffer_size, | |
580 | size_t idx_size, size_t align) | |
581 | { | |
582 | int nr_objs; | |
583 | size_t freelist_size; | |
584 | ||
585 | /* | |
586 | * Ignore padding for the initial guess. The padding | |
587 | * is at most @align-1 bytes, and @buffer_size is at | |
588 | * least @align. In the worst case, this result will | |
589 | * be one greater than the number of objects that fit | |
590 | * into the memory allocation when taking the padding | |
591 | * into account. | |
592 | */ | |
593 | nr_objs = slab_size / (buffer_size + idx_size); | |
594 | ||
595 | /* | |
596 | * This calculated number will be either the right | |
597 | * amount, or one greater than what we want. | |
598 | */ | |
599 | freelist_size = slab_size - nr_objs * buffer_size; | |
600 | if (freelist_size < ALIGN(nr_objs * idx_size, align)) | |
601 | nr_objs--; | |
602 | ||
603 | return nr_objs; | |
604 | } | |
605 | ||
606 | /* | |
607 | * Calculate the number of objects and left-over bytes for a given buffer size. | |
608 | */ | |
609 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, | |
610 | size_t align, int flags, size_t *left_over, | |
611 | unsigned int *num) | |
612 | { | |
613 | int nr_objs; | |
614 | size_t mgmt_size; | |
615 | size_t slab_size = PAGE_SIZE << gfporder; | |
616 | ||
617 | /* | |
618 | * The slab management structure can be either off the slab or | |
619 | * on it. For the latter case, the memory allocated for a | |
620 | * slab is used for: | |
621 | * | |
622 | * - One unsigned int for each object | |
623 | * - Padding to respect alignment of @align | |
624 | * - @buffer_size bytes for each object | |
625 | * | |
626 | * If the slab management structure is off the slab, then the | |
627 | * alignment will already be calculated into the size. Because | |
628 | * the slabs are all pages aligned, the objects will be at the | |
629 | * correct alignment when allocated. | |
630 | */ | |
631 | if (flags & CFLGS_OFF_SLAB) { | |
632 | mgmt_size = 0; | |
633 | nr_objs = slab_size / buffer_size; | |
634 | ||
635 | } else { | |
636 | nr_objs = calculate_nr_objs(slab_size, buffer_size, | |
637 | sizeof(freelist_idx_t), align); | |
638 | mgmt_size = ALIGN(nr_objs * sizeof(freelist_idx_t), align); | |
639 | } | |
640 | *num = nr_objs; | |
641 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; | |
642 | } | |
643 | ||
644 | #if DEBUG | |
645 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) | |
646 | ||
647 | static void __slab_error(const char *function, struct kmem_cache *cachep, | |
648 | char *msg) | |
649 | { | |
650 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", | |
651 | function, cachep->name, msg); | |
652 | dump_stack(); | |
653 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); | |
654 | } | |
655 | #endif | |
656 | ||
657 | /* | |
658 | * By default on NUMA we use alien caches to stage the freeing of | |
659 | * objects allocated from other nodes. This causes massive memory | |
660 | * inefficiencies when using fake NUMA setup to split memory into a | |
661 | * large number of small nodes, so it can be disabled on the command | |
662 | * line | |
663 | */ | |
664 | ||
665 | static int use_alien_caches __read_mostly = 1; | |
666 | static int __init noaliencache_setup(char *s) | |
667 | { | |
668 | use_alien_caches = 0; | |
669 | return 1; | |
670 | } | |
671 | __setup("noaliencache", noaliencache_setup); | |
672 | ||
673 | static int __init slab_max_order_setup(char *str) | |
674 | { | |
675 | get_option(&str, &slab_max_order); | |
676 | slab_max_order = slab_max_order < 0 ? 0 : | |
677 | min(slab_max_order, MAX_ORDER - 1); | |
678 | slab_max_order_set = true; | |
679 | ||
680 | return 1; | |
681 | } | |
682 | __setup("slab_max_order=", slab_max_order_setup); | |
683 | ||
684 | #ifdef CONFIG_NUMA | |
685 | /* | |
686 | * Special reaping functions for NUMA systems called from cache_reap(). | |
687 | * These take care of doing round robin flushing of alien caches (containing | |
688 | * objects freed on different nodes from which they were allocated) and the | |
689 | * flushing of remote pcps by calling drain_node_pages. | |
690 | */ | |
691 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); | |
692 | ||
693 | static void init_reap_node(int cpu) | |
694 | { | |
695 | int node; | |
696 | ||
697 | node = next_node(cpu_to_mem(cpu), node_online_map); | |
698 | if (node == MAX_NUMNODES) | |
699 | node = first_node(node_online_map); | |
700 | ||
701 | per_cpu(slab_reap_node, cpu) = node; | |
702 | } | |
703 | ||
704 | static void next_reap_node(void) | |
705 | { | |
706 | int node = __this_cpu_read(slab_reap_node); | |
707 | ||
708 | node = next_node(node, node_online_map); | |
709 | if (unlikely(node >= MAX_NUMNODES)) | |
710 | node = first_node(node_online_map); | |
711 | __this_cpu_write(slab_reap_node, node); | |
712 | } | |
713 | ||
714 | #else | |
715 | #define init_reap_node(cpu) do { } while (0) | |
716 | #define next_reap_node(void) do { } while (0) | |
717 | #endif | |
718 | ||
719 | /* | |
720 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz | |
721 | * via the workqueue/eventd. | |
722 | * Add the CPU number into the expiration time to minimize the possibility of | |
723 | * the CPUs getting into lockstep and contending for the global cache chain | |
724 | * lock. | |
725 | */ | |
726 | static void start_cpu_timer(int cpu) | |
727 | { | |
728 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); | |
729 | ||
730 | /* | |
731 | * When this gets called from do_initcalls via cpucache_init(), | |
732 | * init_workqueues() has already run, so keventd will be setup | |
733 | * at that time. | |
734 | */ | |
735 | if (keventd_up() && reap_work->work.func == NULL) { | |
736 | init_reap_node(cpu); | |
737 | INIT_DEFERRABLE_WORK(reap_work, cache_reap); | |
738 | schedule_delayed_work_on(cpu, reap_work, | |
739 | __round_jiffies_relative(HZ, cpu)); | |
740 | } | |
741 | } | |
742 | ||
743 | static struct array_cache *alloc_arraycache(int node, int entries, | |
744 | int batchcount, gfp_t gfp) | |
745 | { | |
746 | int memsize = sizeof(void *) * entries + sizeof(struct array_cache); | |
747 | struct array_cache *nc = NULL; | |
748 | ||
749 | nc = kmalloc_node(memsize, gfp, node); | |
750 | /* | |
751 | * The array_cache structures contain pointers to free object. | |
752 | * However, when such objects are allocated or transferred to another | |
753 | * cache the pointers are not cleared and they could be counted as | |
754 | * valid references during a kmemleak scan. Therefore, kmemleak must | |
755 | * not scan such objects. | |
756 | */ | |
757 | kmemleak_no_scan(nc); | |
758 | if (nc) { | |
759 | nc->avail = 0; | |
760 | nc->limit = entries; | |
761 | nc->batchcount = batchcount; | |
762 | nc->touched = 0; | |
763 | spin_lock_init(&nc->lock); | |
764 | } | |
765 | return nc; | |
766 | } | |
767 | ||
768 | static inline bool is_slab_pfmemalloc(struct page *page) | |
769 | { | |
770 | return PageSlabPfmemalloc(page); | |
771 | } | |
772 | ||
773 | /* Clears pfmemalloc_active if no slabs have pfmalloc set */ | |
774 | static void recheck_pfmemalloc_active(struct kmem_cache *cachep, | |
775 | struct array_cache *ac) | |
776 | { | |
777 | struct kmem_cache_node *n = cachep->node[numa_mem_id()]; | |
778 | struct page *page; | |
779 | unsigned long flags; | |
780 | ||
781 | if (!pfmemalloc_active) | |
782 | return; | |
783 | ||
784 | spin_lock_irqsave(&n->list_lock, flags); | |
785 | list_for_each_entry(page, &n->slabs_full, lru) | |
786 | if (is_slab_pfmemalloc(page)) | |
787 | goto out; | |
788 | ||
789 | list_for_each_entry(page, &n->slabs_partial, lru) | |
790 | if (is_slab_pfmemalloc(page)) | |
791 | goto out; | |
792 | ||
793 | list_for_each_entry(page, &n->slabs_free, lru) | |
794 | if (is_slab_pfmemalloc(page)) | |
795 | goto out; | |
796 | ||
797 | pfmemalloc_active = false; | |
798 | out: | |
799 | spin_unlock_irqrestore(&n->list_lock, flags); | |
800 | } | |
801 | ||
802 | static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, | |
803 | gfp_t flags, bool force_refill) | |
804 | { | |
805 | int i; | |
806 | void *objp = ac->entry[--ac->avail]; | |
807 | ||
808 | /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ | |
809 | if (unlikely(is_obj_pfmemalloc(objp))) { | |
810 | struct kmem_cache_node *n; | |
811 | ||
812 | if (gfp_pfmemalloc_allowed(flags)) { | |
813 | clear_obj_pfmemalloc(&objp); | |
814 | return objp; | |
815 | } | |
816 | ||
817 | /* The caller cannot use PFMEMALLOC objects, find another one */ | |
818 | for (i = 0; i < ac->avail; i++) { | |
819 | /* If a !PFMEMALLOC object is found, swap them */ | |
820 | if (!is_obj_pfmemalloc(ac->entry[i])) { | |
821 | objp = ac->entry[i]; | |
822 | ac->entry[i] = ac->entry[ac->avail]; | |
823 | ac->entry[ac->avail] = objp; | |
824 | return objp; | |
825 | } | |
826 | } | |
827 | ||
828 | /* | |
829 | * If there are empty slabs on the slabs_free list and we are | |
830 | * being forced to refill the cache, mark this one !pfmemalloc. | |
831 | */ | |
832 | n = cachep->node[numa_mem_id()]; | |
833 | if (!list_empty(&n->slabs_free) && force_refill) { | |
834 | struct page *page = virt_to_head_page(objp); | |
835 | ClearPageSlabPfmemalloc(page); | |
836 | clear_obj_pfmemalloc(&objp); | |
837 | recheck_pfmemalloc_active(cachep, ac); | |
838 | return objp; | |
839 | } | |
840 | ||
841 | /* No !PFMEMALLOC objects available */ | |
842 | ac->avail++; | |
843 | objp = NULL; | |
844 | } | |
845 | ||
846 | return objp; | |
847 | } | |
848 | ||
849 | static inline void *ac_get_obj(struct kmem_cache *cachep, | |
850 | struct array_cache *ac, gfp_t flags, bool force_refill) | |
851 | { | |
852 | void *objp; | |
853 | ||
854 | if (unlikely(sk_memalloc_socks())) | |
855 | objp = __ac_get_obj(cachep, ac, flags, force_refill); | |
856 | else | |
857 | objp = ac->entry[--ac->avail]; | |
858 | ||
859 | return objp; | |
860 | } | |
861 | ||
862 | static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, | |
863 | void *objp) | |
864 | { | |
865 | if (unlikely(pfmemalloc_active)) { | |
866 | /* Some pfmemalloc slabs exist, check if this is one */ | |
867 | struct page *page = virt_to_head_page(objp); | |
868 | if (PageSlabPfmemalloc(page)) | |
869 | set_obj_pfmemalloc(&objp); | |
870 | } | |
871 | ||
872 | return objp; | |
873 | } | |
874 | ||
875 | static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, | |
876 | void *objp) | |
877 | { | |
878 | if (unlikely(sk_memalloc_socks())) | |
879 | objp = __ac_put_obj(cachep, ac, objp); | |
880 | ||
881 | ac->entry[ac->avail++] = objp; | |
882 | } | |
883 | ||
884 | /* | |
885 | * Transfer objects in one arraycache to another. | |
886 | * Locking must be handled by the caller. | |
887 | * | |
888 | * Return the number of entries transferred. | |
889 | */ | |
890 | static int transfer_objects(struct array_cache *to, | |
891 | struct array_cache *from, unsigned int max) | |
892 | { | |
893 | /* Figure out how many entries to transfer */ | |
894 | int nr = min3(from->avail, max, to->limit - to->avail); | |
895 | ||
896 | if (!nr) | |
897 | return 0; | |
898 | ||
899 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, | |
900 | sizeof(void *) *nr); | |
901 | ||
902 | from->avail -= nr; | |
903 | to->avail += nr; | |
904 | return nr; | |
905 | } | |
906 | ||
907 | #ifndef CONFIG_NUMA | |
908 | ||
909 | #define drain_alien_cache(cachep, alien) do { } while (0) | |
910 | #define reap_alien(cachep, n) do { } while (0) | |
911 | ||
912 | static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) | |
913 | { | |
914 | return (struct array_cache **)BAD_ALIEN_MAGIC; | |
915 | } | |
916 | ||
917 | static inline void free_alien_cache(struct array_cache **ac_ptr) | |
918 | { | |
919 | } | |
920 | ||
921 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
922 | { | |
923 | return 0; | |
924 | } | |
925 | ||
926 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, | |
927 | gfp_t flags) | |
928 | { | |
929 | return NULL; | |
930 | } | |
931 | ||
932 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, | |
933 | gfp_t flags, int nodeid) | |
934 | { | |
935 | return NULL; | |
936 | } | |
937 | ||
938 | #else /* CONFIG_NUMA */ | |
939 | ||
940 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); | |
941 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); | |
942 | ||
943 | static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) | |
944 | { | |
945 | struct array_cache **ac_ptr; | |
946 | int memsize = sizeof(void *) * nr_node_ids; | |
947 | int i; | |
948 | ||
949 | if (limit > 1) | |
950 | limit = 12; | |
951 | ac_ptr = kzalloc_node(memsize, gfp, node); | |
952 | if (ac_ptr) { | |
953 | for_each_node(i) { | |
954 | if (i == node || !node_online(i)) | |
955 | continue; | |
956 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); | |
957 | if (!ac_ptr[i]) { | |
958 | for (i--; i >= 0; i--) | |
959 | kfree(ac_ptr[i]); | |
960 | kfree(ac_ptr); | |
961 | return NULL; | |
962 | } | |
963 | } | |
964 | } | |
965 | return ac_ptr; | |
966 | } | |
967 | ||
968 | static void free_alien_cache(struct array_cache **ac_ptr) | |
969 | { | |
970 | int i; | |
971 | ||
972 | if (!ac_ptr) | |
973 | return; | |
974 | for_each_node(i) | |
975 | kfree(ac_ptr[i]); | |
976 | kfree(ac_ptr); | |
977 | } | |
978 | ||
979 | static void __drain_alien_cache(struct kmem_cache *cachep, | |
980 | struct array_cache *ac, int node) | |
981 | { | |
982 | struct kmem_cache_node *n = cachep->node[node]; | |
983 | ||
984 | if (ac->avail) { | |
985 | spin_lock(&n->list_lock); | |
986 | /* | |
987 | * Stuff objects into the remote nodes shared array first. | |
988 | * That way we could avoid the overhead of putting the objects | |
989 | * into the free lists and getting them back later. | |
990 | */ | |
991 | if (n->shared) | |
992 | transfer_objects(n->shared, ac, ac->limit); | |
993 | ||
994 | free_block(cachep, ac->entry, ac->avail, node); | |
995 | ac->avail = 0; | |
996 | spin_unlock(&n->list_lock); | |
997 | } | |
998 | } | |
999 | ||
1000 | /* | |
1001 | * Called from cache_reap() to regularly drain alien caches round robin. | |
1002 | */ | |
1003 | static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) | |
1004 | { | |
1005 | int node = __this_cpu_read(slab_reap_node); | |
1006 | ||
1007 | if (n->alien) { | |
1008 | struct array_cache *ac = n->alien[node]; | |
1009 | ||
1010 | if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { | |
1011 | __drain_alien_cache(cachep, ac, node); | |
1012 | spin_unlock_irq(&ac->lock); | |
1013 | } | |
1014 | } | |
1015 | } | |
1016 | ||
1017 | static void drain_alien_cache(struct kmem_cache *cachep, | |
1018 | struct array_cache **alien) | |
1019 | { | |
1020 | int i = 0; | |
1021 | struct array_cache *ac; | |
1022 | unsigned long flags; | |
1023 | ||
1024 | for_each_online_node(i) { | |
1025 | ac = alien[i]; | |
1026 | if (ac) { | |
1027 | spin_lock_irqsave(&ac->lock, flags); | |
1028 | __drain_alien_cache(cachep, ac, i); | |
1029 | spin_unlock_irqrestore(&ac->lock, flags); | |
1030 | } | |
1031 | } | |
1032 | } | |
1033 | ||
1034 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
1035 | { | |
1036 | int nodeid = page_to_nid(virt_to_page(objp)); | |
1037 | struct kmem_cache_node *n; | |
1038 | struct array_cache *alien = NULL; | |
1039 | int node; | |
1040 | ||
1041 | node = numa_mem_id(); | |
1042 | ||
1043 | /* | |
1044 | * Make sure we are not freeing a object from another node to the array | |
1045 | * cache on this cpu. | |
1046 | */ | |
1047 | if (likely(nodeid == node)) | |
1048 | return 0; | |
1049 | ||
1050 | n = cachep->node[node]; | |
1051 | STATS_INC_NODEFREES(cachep); | |
1052 | if (n->alien && n->alien[nodeid]) { | |
1053 | alien = n->alien[nodeid]; | |
1054 | spin_lock(&alien->lock); | |
1055 | if (unlikely(alien->avail == alien->limit)) { | |
1056 | STATS_INC_ACOVERFLOW(cachep); | |
1057 | __drain_alien_cache(cachep, alien, nodeid); | |
1058 | } | |
1059 | ac_put_obj(cachep, alien, objp); | |
1060 | spin_unlock(&alien->lock); | |
1061 | } else { | |
1062 | spin_lock(&(cachep->node[nodeid])->list_lock); | |
1063 | free_block(cachep, &objp, 1, nodeid); | |
1064 | spin_unlock(&(cachep->node[nodeid])->list_lock); | |
1065 | } | |
1066 | return 1; | |
1067 | } | |
1068 | #endif | |
1069 | ||
1070 | /* | |
1071 | * Allocates and initializes node for a node on each slab cache, used for | |
1072 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node | |
1073 | * will be allocated off-node since memory is not yet online for the new node. | |
1074 | * When hotplugging memory or a cpu, existing node are not replaced if | |
1075 | * already in use. | |
1076 | * | |
1077 | * Must hold slab_mutex. | |
1078 | */ | |
1079 | static int init_cache_node_node(int node) | |
1080 | { | |
1081 | struct kmem_cache *cachep; | |
1082 | struct kmem_cache_node *n; | |
1083 | const int memsize = sizeof(struct kmem_cache_node); | |
1084 | ||
1085 | list_for_each_entry(cachep, &slab_caches, list) { | |
1086 | /* | |
1087 | * Set up the kmem_cache_node for cpu before we can | |
1088 | * begin anything. Make sure some other cpu on this | |
1089 | * node has not already allocated this | |
1090 | */ | |
1091 | if (!cachep->node[node]) { | |
1092 | n = kmalloc_node(memsize, GFP_KERNEL, node); | |
1093 | if (!n) | |
1094 | return -ENOMEM; | |
1095 | kmem_cache_node_init(n); | |
1096 | n->next_reap = jiffies + REAPTIMEOUT_NODE + | |
1097 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; | |
1098 | ||
1099 | /* | |
1100 | * The kmem_cache_nodes don't come and go as CPUs | |
1101 | * come and go. slab_mutex is sufficient | |
1102 | * protection here. | |
1103 | */ | |
1104 | cachep->node[node] = n; | |
1105 | } | |
1106 | ||
1107 | spin_lock_irq(&cachep->node[node]->list_lock); | |
1108 | cachep->node[node]->free_limit = | |
1109 | (1 + nr_cpus_node(node)) * | |
1110 | cachep->batchcount + cachep->num; | |
1111 | spin_unlock_irq(&cachep->node[node]->list_lock); | |
1112 | } | |
1113 | return 0; | |
1114 | } | |
1115 | ||
1116 | static inline int slabs_tofree(struct kmem_cache *cachep, | |
1117 | struct kmem_cache_node *n) | |
1118 | { | |
1119 | return (n->free_objects + cachep->num - 1) / cachep->num; | |
1120 | } | |
1121 | ||
1122 | static void cpuup_canceled(long cpu) | |
1123 | { | |
1124 | struct kmem_cache *cachep; | |
1125 | struct kmem_cache_node *n = NULL; | |
1126 | int node = cpu_to_mem(cpu); | |
1127 | const struct cpumask *mask = cpumask_of_node(node); | |
1128 | ||
1129 | list_for_each_entry(cachep, &slab_caches, list) { | |
1130 | struct array_cache *nc; | |
1131 | struct array_cache *shared; | |
1132 | struct array_cache **alien; | |
1133 | ||
1134 | /* cpu is dead; no one can alloc from it. */ | |
1135 | nc = cachep->array[cpu]; | |
1136 | cachep->array[cpu] = NULL; | |
1137 | n = cachep->node[node]; | |
1138 | ||
1139 | if (!n) | |
1140 | goto free_array_cache; | |
1141 | ||
1142 | spin_lock_irq(&n->list_lock); | |
1143 | ||
1144 | /* Free limit for this kmem_cache_node */ | |
1145 | n->free_limit -= cachep->batchcount; | |
1146 | if (nc) | |
1147 | free_block(cachep, nc->entry, nc->avail, node); | |
1148 | ||
1149 | if (!cpumask_empty(mask)) { | |
1150 | spin_unlock_irq(&n->list_lock); | |
1151 | goto free_array_cache; | |
1152 | } | |
1153 | ||
1154 | shared = n->shared; | |
1155 | if (shared) { | |
1156 | free_block(cachep, shared->entry, | |
1157 | shared->avail, node); | |
1158 | n->shared = NULL; | |
1159 | } | |
1160 | ||
1161 | alien = n->alien; | |
1162 | n->alien = NULL; | |
1163 | ||
1164 | spin_unlock_irq(&n->list_lock); | |
1165 | ||
1166 | kfree(shared); | |
1167 | if (alien) { | |
1168 | drain_alien_cache(cachep, alien); | |
1169 | free_alien_cache(alien); | |
1170 | } | |
1171 | free_array_cache: | |
1172 | kfree(nc); | |
1173 | } | |
1174 | /* | |
1175 | * In the previous loop, all the objects were freed to | |
1176 | * the respective cache's slabs, now we can go ahead and | |
1177 | * shrink each nodelist to its limit. | |
1178 | */ | |
1179 | list_for_each_entry(cachep, &slab_caches, list) { | |
1180 | n = cachep->node[node]; | |
1181 | if (!n) | |
1182 | continue; | |
1183 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); | |
1184 | } | |
1185 | } | |
1186 | ||
1187 | static int cpuup_prepare(long cpu) | |
1188 | { | |
1189 | struct kmem_cache *cachep; | |
1190 | struct kmem_cache_node *n = NULL; | |
1191 | int node = cpu_to_mem(cpu); | |
1192 | int err; | |
1193 | ||
1194 | /* | |
1195 | * We need to do this right in the beginning since | |
1196 | * alloc_arraycache's are going to use this list. | |
1197 | * kmalloc_node allows us to add the slab to the right | |
1198 | * kmem_cache_node and not this cpu's kmem_cache_node | |
1199 | */ | |
1200 | err = init_cache_node_node(node); | |
1201 | if (err < 0) | |
1202 | goto bad; | |
1203 | ||
1204 | /* | |
1205 | * Now we can go ahead with allocating the shared arrays and | |
1206 | * array caches | |
1207 | */ | |
1208 | list_for_each_entry(cachep, &slab_caches, list) { | |
1209 | struct array_cache *nc; | |
1210 | struct array_cache *shared = NULL; | |
1211 | struct array_cache **alien = NULL; | |
1212 | ||
1213 | nc = alloc_arraycache(node, cachep->limit, | |
1214 | cachep->batchcount, GFP_KERNEL); | |
1215 | if (!nc) | |
1216 | goto bad; | |
1217 | if (cachep->shared) { | |
1218 | shared = alloc_arraycache(node, | |
1219 | cachep->shared * cachep->batchcount, | |
1220 | 0xbaadf00d, GFP_KERNEL); | |
1221 | if (!shared) { | |
1222 | kfree(nc); | |
1223 | goto bad; | |
1224 | } | |
1225 | } | |
1226 | if (use_alien_caches) { | |
1227 | alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); | |
1228 | if (!alien) { | |
1229 | kfree(shared); | |
1230 | kfree(nc); | |
1231 | goto bad; | |
1232 | } | |
1233 | } | |
1234 | cachep->array[cpu] = nc; | |
1235 | n = cachep->node[node]; | |
1236 | BUG_ON(!n); | |
1237 | ||
1238 | spin_lock_irq(&n->list_lock); | |
1239 | if (!n->shared) { | |
1240 | /* | |
1241 | * We are serialised from CPU_DEAD or | |
1242 | * CPU_UP_CANCELLED by the cpucontrol lock | |
1243 | */ | |
1244 | n->shared = shared; | |
1245 | shared = NULL; | |
1246 | } | |
1247 | #ifdef CONFIG_NUMA | |
1248 | if (!n->alien) { | |
1249 | n->alien = alien; | |
1250 | alien = NULL; | |
1251 | } | |
1252 | #endif | |
1253 | spin_unlock_irq(&n->list_lock); | |
1254 | kfree(shared); | |
1255 | free_alien_cache(alien); | |
1256 | if (cachep->flags & SLAB_DEBUG_OBJECTS) | |
1257 | slab_set_debugobj_lock_classes_node(cachep, node); | |
1258 | else if (!OFF_SLAB(cachep) && | |
1259 | !(cachep->flags & SLAB_DESTROY_BY_RCU)) | |
1260 | on_slab_lock_classes_node(cachep, node); | |
1261 | } | |
1262 | init_node_lock_keys(node); | |
1263 | ||
1264 | return 0; | |
1265 | bad: | |
1266 | cpuup_canceled(cpu); | |
1267 | return -ENOMEM; | |
1268 | } | |
1269 | ||
1270 | static int cpuup_callback(struct notifier_block *nfb, | |
1271 | unsigned long action, void *hcpu) | |
1272 | { | |
1273 | long cpu = (long)hcpu; | |
1274 | int err = 0; | |
1275 | ||
1276 | switch (action) { | |
1277 | case CPU_UP_PREPARE: | |
1278 | case CPU_UP_PREPARE_FROZEN: | |
1279 | mutex_lock(&slab_mutex); | |
1280 | err = cpuup_prepare(cpu); | |
1281 | mutex_unlock(&slab_mutex); | |
1282 | break; | |
1283 | case CPU_ONLINE: | |
1284 | case CPU_ONLINE_FROZEN: | |
1285 | start_cpu_timer(cpu); | |
1286 | break; | |
1287 | #ifdef CONFIG_HOTPLUG_CPU | |
1288 | case CPU_DOWN_PREPARE: | |
1289 | case CPU_DOWN_PREPARE_FROZEN: | |
1290 | /* | |
1291 | * Shutdown cache reaper. Note that the slab_mutex is | |
1292 | * held so that if cache_reap() is invoked it cannot do | |
1293 | * anything expensive but will only modify reap_work | |
1294 | * and reschedule the timer. | |
1295 | */ | |
1296 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); | |
1297 | /* Now the cache_reaper is guaranteed to be not running. */ | |
1298 | per_cpu(slab_reap_work, cpu).work.func = NULL; | |
1299 | break; | |
1300 | case CPU_DOWN_FAILED: | |
1301 | case CPU_DOWN_FAILED_FROZEN: | |
1302 | start_cpu_timer(cpu); | |
1303 | break; | |
1304 | case CPU_DEAD: | |
1305 | case CPU_DEAD_FROZEN: | |
1306 | /* | |
1307 | * Even if all the cpus of a node are down, we don't free the | |
1308 | * kmem_cache_node of any cache. This to avoid a race between | |
1309 | * cpu_down, and a kmalloc allocation from another cpu for | |
1310 | * memory from the node of the cpu going down. The node | |
1311 | * structure is usually allocated from kmem_cache_create() and | |
1312 | * gets destroyed at kmem_cache_destroy(). | |
1313 | */ | |
1314 | /* fall through */ | |
1315 | #endif | |
1316 | case CPU_UP_CANCELED: | |
1317 | case CPU_UP_CANCELED_FROZEN: | |
1318 | mutex_lock(&slab_mutex); | |
1319 | cpuup_canceled(cpu); | |
1320 | mutex_unlock(&slab_mutex); | |
1321 | break; | |
1322 | } | |
1323 | return notifier_from_errno(err); | |
1324 | } | |
1325 | ||
1326 | static struct notifier_block cpucache_notifier = { | |
1327 | &cpuup_callback, NULL, 0 | |
1328 | }; | |
1329 | ||
1330 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) | |
1331 | /* | |
1332 | * Drains freelist for a node on each slab cache, used for memory hot-remove. | |
1333 | * Returns -EBUSY if all objects cannot be drained so that the node is not | |
1334 | * removed. | |
1335 | * | |
1336 | * Must hold slab_mutex. | |
1337 | */ | |
1338 | static int __meminit drain_cache_node_node(int node) | |
1339 | { | |
1340 | struct kmem_cache *cachep; | |
1341 | int ret = 0; | |
1342 | ||
1343 | list_for_each_entry(cachep, &slab_caches, list) { | |
1344 | struct kmem_cache_node *n; | |
1345 | ||
1346 | n = cachep->node[node]; | |
1347 | if (!n) | |
1348 | continue; | |
1349 | ||
1350 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); | |
1351 | ||
1352 | if (!list_empty(&n->slabs_full) || | |
1353 | !list_empty(&n->slabs_partial)) { | |
1354 | ret = -EBUSY; | |
1355 | break; | |
1356 | } | |
1357 | } | |
1358 | return ret; | |
1359 | } | |
1360 | ||
1361 | static int __meminit slab_memory_callback(struct notifier_block *self, | |
1362 | unsigned long action, void *arg) | |
1363 | { | |
1364 | struct memory_notify *mnb = arg; | |
1365 | int ret = 0; | |
1366 | int nid; | |
1367 | ||
1368 | nid = mnb->status_change_nid; | |
1369 | if (nid < 0) | |
1370 | goto out; | |
1371 | ||
1372 | switch (action) { | |
1373 | case MEM_GOING_ONLINE: | |
1374 | mutex_lock(&slab_mutex); | |
1375 | ret = init_cache_node_node(nid); | |
1376 | mutex_unlock(&slab_mutex); | |
1377 | break; | |
1378 | case MEM_GOING_OFFLINE: | |
1379 | mutex_lock(&slab_mutex); | |
1380 | ret = drain_cache_node_node(nid); | |
1381 | mutex_unlock(&slab_mutex); | |
1382 | break; | |
1383 | case MEM_ONLINE: | |
1384 | case MEM_OFFLINE: | |
1385 | case MEM_CANCEL_ONLINE: | |
1386 | case MEM_CANCEL_OFFLINE: | |
1387 | break; | |
1388 | } | |
1389 | out: | |
1390 | return notifier_from_errno(ret); | |
1391 | } | |
1392 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ | |
1393 | ||
1394 | /* | |
1395 | * swap the static kmem_cache_node with kmalloced memory | |
1396 | */ | |
1397 | static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, | |
1398 | int nodeid) | |
1399 | { | |
1400 | struct kmem_cache_node *ptr; | |
1401 | ||
1402 | ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); | |
1403 | BUG_ON(!ptr); | |
1404 | ||
1405 | memcpy(ptr, list, sizeof(struct kmem_cache_node)); | |
1406 | /* | |
1407 | * Do not assume that spinlocks can be initialized via memcpy: | |
1408 | */ | |
1409 | spin_lock_init(&ptr->list_lock); | |
1410 | ||
1411 | MAKE_ALL_LISTS(cachep, ptr, nodeid); | |
1412 | cachep->node[nodeid] = ptr; | |
1413 | } | |
1414 | ||
1415 | /* | |
1416 | * For setting up all the kmem_cache_node for cache whose buffer_size is same as | |
1417 | * size of kmem_cache_node. | |
1418 | */ | |
1419 | static void __init set_up_node(struct kmem_cache *cachep, int index) | |
1420 | { | |
1421 | int node; | |
1422 | ||
1423 | for_each_online_node(node) { | |
1424 | cachep->node[node] = &init_kmem_cache_node[index + node]; | |
1425 | cachep->node[node]->next_reap = jiffies + | |
1426 | REAPTIMEOUT_NODE + | |
1427 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; | |
1428 | } | |
1429 | } | |
1430 | ||
1431 | /* | |
1432 | * The memory after the last cpu cache pointer is used for the | |
1433 | * the node pointer. | |
1434 | */ | |
1435 | static void setup_node_pointer(struct kmem_cache *cachep) | |
1436 | { | |
1437 | cachep->node = (struct kmem_cache_node **)&cachep->array[nr_cpu_ids]; | |
1438 | } | |
1439 | ||
1440 | /* | |
1441 | * Initialisation. Called after the page allocator have been initialised and | |
1442 | * before smp_init(). | |
1443 | */ | |
1444 | void __init kmem_cache_init(void) | |
1445 | { | |
1446 | int i; | |
1447 | ||
1448 | BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) < | |
1449 | sizeof(struct rcu_head)); | |
1450 | kmem_cache = &kmem_cache_boot; | |
1451 | setup_node_pointer(kmem_cache); | |
1452 | ||
1453 | if (num_possible_nodes() == 1) | |
1454 | use_alien_caches = 0; | |
1455 | ||
1456 | for (i = 0; i < NUM_INIT_LISTS; i++) | |
1457 | kmem_cache_node_init(&init_kmem_cache_node[i]); | |
1458 | ||
1459 | set_up_node(kmem_cache, CACHE_CACHE); | |
1460 | ||
1461 | /* | |
1462 | * Fragmentation resistance on low memory - only use bigger | |
1463 | * page orders on machines with more than 32MB of memory if | |
1464 | * not overridden on the command line. | |
1465 | */ | |
1466 | if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) | |
1467 | slab_max_order = SLAB_MAX_ORDER_HI; | |
1468 | ||
1469 | /* Bootstrap is tricky, because several objects are allocated | |
1470 | * from caches that do not exist yet: | |
1471 | * 1) initialize the kmem_cache cache: it contains the struct | |
1472 | * kmem_cache structures of all caches, except kmem_cache itself: | |
1473 | * kmem_cache is statically allocated. | |
1474 | * Initially an __init data area is used for the head array and the | |
1475 | * kmem_cache_node structures, it's replaced with a kmalloc allocated | |
1476 | * array at the end of the bootstrap. | |
1477 | * 2) Create the first kmalloc cache. | |
1478 | * The struct kmem_cache for the new cache is allocated normally. | |
1479 | * An __init data area is used for the head array. | |
1480 | * 3) Create the remaining kmalloc caches, with minimally sized | |
1481 | * head arrays. | |
1482 | * 4) Replace the __init data head arrays for kmem_cache and the first | |
1483 | * kmalloc cache with kmalloc allocated arrays. | |
1484 | * 5) Replace the __init data for kmem_cache_node for kmem_cache and | |
1485 | * the other cache's with kmalloc allocated memory. | |
1486 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. | |
1487 | */ | |
1488 | ||
1489 | /* 1) create the kmem_cache */ | |
1490 | ||
1491 | /* | |
1492 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids | |
1493 | */ | |
1494 | create_boot_cache(kmem_cache, "kmem_cache", | |
1495 | offsetof(struct kmem_cache, array[nr_cpu_ids]) + | |
1496 | nr_node_ids * sizeof(struct kmem_cache_node *), | |
1497 | SLAB_HWCACHE_ALIGN); | |
1498 | list_add(&kmem_cache->list, &slab_caches); | |
1499 | ||
1500 | /* 2+3) create the kmalloc caches */ | |
1501 | ||
1502 | /* | |
1503 | * Initialize the caches that provide memory for the array cache and the | |
1504 | * kmem_cache_node structures first. Without this, further allocations will | |
1505 | * bug. | |
1506 | */ | |
1507 | ||
1508 | kmalloc_caches[INDEX_AC] = create_kmalloc_cache("kmalloc-ac", | |
1509 | kmalloc_size(INDEX_AC), ARCH_KMALLOC_FLAGS); | |
1510 | ||
1511 | if (INDEX_AC != INDEX_NODE) | |
1512 | kmalloc_caches[INDEX_NODE] = | |
1513 | create_kmalloc_cache("kmalloc-node", | |
1514 | kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); | |
1515 | ||
1516 | slab_early_init = 0; | |
1517 | ||
1518 | /* 4) Replace the bootstrap head arrays */ | |
1519 | { | |
1520 | struct array_cache *ptr; | |
1521 | ||
1522 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); | |
1523 | ||
1524 | memcpy(ptr, cpu_cache_get(kmem_cache), | |
1525 | sizeof(struct arraycache_init)); | |
1526 | /* | |
1527 | * Do not assume that spinlocks can be initialized via memcpy: | |
1528 | */ | |
1529 | spin_lock_init(&ptr->lock); | |
1530 | ||
1531 | kmem_cache->array[smp_processor_id()] = ptr; | |
1532 | ||
1533 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); | |
1534 | ||
1535 | BUG_ON(cpu_cache_get(kmalloc_caches[INDEX_AC]) | |
1536 | != &initarray_generic.cache); | |
1537 | memcpy(ptr, cpu_cache_get(kmalloc_caches[INDEX_AC]), | |
1538 | sizeof(struct arraycache_init)); | |
1539 | /* | |
1540 | * Do not assume that spinlocks can be initialized via memcpy: | |
1541 | */ | |
1542 | spin_lock_init(&ptr->lock); | |
1543 | ||
1544 | kmalloc_caches[INDEX_AC]->array[smp_processor_id()] = ptr; | |
1545 | } | |
1546 | /* 5) Replace the bootstrap kmem_cache_node */ | |
1547 | { | |
1548 | int nid; | |
1549 | ||
1550 | for_each_online_node(nid) { | |
1551 | init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); | |
1552 | ||
1553 | init_list(kmalloc_caches[INDEX_AC], | |
1554 | &init_kmem_cache_node[SIZE_AC + nid], nid); | |
1555 | ||
1556 | if (INDEX_AC != INDEX_NODE) { | |
1557 | init_list(kmalloc_caches[INDEX_NODE], | |
1558 | &init_kmem_cache_node[SIZE_NODE + nid], nid); | |
1559 | } | |
1560 | } | |
1561 | } | |
1562 | ||
1563 | create_kmalloc_caches(ARCH_KMALLOC_FLAGS); | |
1564 | } | |
1565 | ||
1566 | void __init kmem_cache_init_late(void) | |
1567 | { | |
1568 | struct kmem_cache *cachep; | |
1569 | ||
1570 | slab_state = UP; | |
1571 | ||
1572 | /* 6) resize the head arrays to their final sizes */ | |
1573 | mutex_lock(&slab_mutex); | |
1574 | list_for_each_entry(cachep, &slab_caches, list) | |
1575 | if (enable_cpucache(cachep, GFP_NOWAIT)) | |
1576 | BUG(); | |
1577 | mutex_unlock(&slab_mutex); | |
1578 | ||
1579 | /* Annotate slab for lockdep -- annotate the malloc caches */ | |
1580 | init_lock_keys(); | |
1581 | ||
1582 | /* Done! */ | |
1583 | slab_state = FULL; | |
1584 | ||
1585 | /* | |
1586 | * Register a cpu startup notifier callback that initializes | |
1587 | * cpu_cache_get for all new cpus | |
1588 | */ | |
1589 | register_cpu_notifier(&cpucache_notifier); | |
1590 | ||
1591 | #ifdef CONFIG_NUMA | |
1592 | /* | |
1593 | * Register a memory hotplug callback that initializes and frees | |
1594 | * node. | |
1595 | */ | |
1596 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); | |
1597 | #endif | |
1598 | ||
1599 | /* | |
1600 | * The reap timers are started later, with a module init call: That part | |
1601 | * of the kernel is not yet operational. | |
1602 | */ | |
1603 | } | |
1604 | ||
1605 | static int __init cpucache_init(void) | |
1606 | { | |
1607 | int cpu; | |
1608 | ||
1609 | /* | |
1610 | * Register the timers that return unneeded pages to the page allocator | |
1611 | */ | |
1612 | for_each_online_cpu(cpu) | |
1613 | start_cpu_timer(cpu); | |
1614 | ||
1615 | /* Done! */ | |
1616 | slab_state = FULL; | |
1617 | return 0; | |
1618 | } | |
1619 | __initcall(cpucache_init); | |
1620 | ||
1621 | static noinline void | |
1622 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) | |
1623 | { | |
1624 | #if DEBUG | |
1625 | struct kmem_cache_node *n; | |
1626 | struct page *page; | |
1627 | unsigned long flags; | |
1628 | int node; | |
1629 | static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL, | |
1630 | DEFAULT_RATELIMIT_BURST); | |
1631 | ||
1632 | if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs)) | |
1633 | return; | |
1634 | ||
1635 | printk(KERN_WARNING | |
1636 | "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", | |
1637 | nodeid, gfpflags); | |
1638 | printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", | |
1639 | cachep->name, cachep->size, cachep->gfporder); | |
1640 | ||
1641 | for_each_online_node(node) { | |
1642 | unsigned long active_objs = 0, num_objs = 0, free_objects = 0; | |
1643 | unsigned long active_slabs = 0, num_slabs = 0; | |
1644 | ||
1645 | n = cachep->node[node]; | |
1646 | if (!n) | |
1647 | continue; | |
1648 | ||
1649 | spin_lock_irqsave(&n->list_lock, flags); | |
1650 | list_for_each_entry(page, &n->slabs_full, lru) { | |
1651 | active_objs += cachep->num; | |
1652 | active_slabs++; | |
1653 | } | |
1654 | list_for_each_entry(page, &n->slabs_partial, lru) { | |
1655 | active_objs += page->active; | |
1656 | active_slabs++; | |
1657 | } | |
1658 | list_for_each_entry(page, &n->slabs_free, lru) | |
1659 | num_slabs++; | |
1660 | ||
1661 | free_objects += n->free_objects; | |
1662 | spin_unlock_irqrestore(&n->list_lock, flags); | |
1663 | ||
1664 | num_slabs += active_slabs; | |
1665 | num_objs = num_slabs * cachep->num; | |
1666 | printk(KERN_WARNING | |
1667 | " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", | |
1668 | node, active_slabs, num_slabs, active_objs, num_objs, | |
1669 | free_objects); | |
1670 | } | |
1671 | #endif | |
1672 | } | |
1673 | ||
1674 | /* | |
1675 | * Interface to system's page allocator. No need to hold the cache-lock. | |
1676 | * | |
1677 | * If we requested dmaable memory, we will get it. Even if we | |
1678 | * did not request dmaable memory, we might get it, but that | |
1679 | * would be relatively rare and ignorable. | |
1680 | */ | |
1681 | static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, | |
1682 | int nodeid) | |
1683 | { | |
1684 | struct page *page; | |
1685 | int nr_pages; | |
1686 | ||
1687 | flags |= cachep->allocflags; | |
1688 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1689 | flags |= __GFP_RECLAIMABLE; | |
1690 | ||
1691 | if (memcg_charge_slab(cachep, flags, cachep->gfporder)) | |
1692 | return NULL; | |
1693 | ||
1694 | page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); | |
1695 | if (!page) { | |
1696 | memcg_uncharge_slab(cachep, cachep->gfporder); | |
1697 | slab_out_of_memory(cachep, flags, nodeid); | |
1698 | return NULL; | |
1699 | } | |
1700 | ||
1701 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ | |
1702 | if (unlikely(page->pfmemalloc)) | |
1703 | pfmemalloc_active = true; | |
1704 | ||
1705 | nr_pages = (1 << cachep->gfporder); | |
1706 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1707 | add_zone_page_state(page_zone(page), | |
1708 | NR_SLAB_RECLAIMABLE, nr_pages); | |
1709 | else | |
1710 | add_zone_page_state(page_zone(page), | |
1711 | NR_SLAB_UNRECLAIMABLE, nr_pages); | |
1712 | __SetPageSlab(page); | |
1713 | if (page->pfmemalloc) | |
1714 | SetPageSlabPfmemalloc(page); | |
1715 | ||
1716 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { | |
1717 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); | |
1718 | ||
1719 | if (cachep->ctor) | |
1720 | kmemcheck_mark_uninitialized_pages(page, nr_pages); | |
1721 | else | |
1722 | kmemcheck_mark_unallocated_pages(page, nr_pages); | |
1723 | } | |
1724 | ||
1725 | return page; | |
1726 | } | |
1727 | ||
1728 | /* | |
1729 | * Interface to system's page release. | |
1730 | */ | |
1731 | static void kmem_freepages(struct kmem_cache *cachep, struct page *page) | |
1732 | { | |
1733 | const unsigned long nr_freed = (1 << cachep->gfporder); | |
1734 | ||
1735 | kmemcheck_free_shadow(page, cachep->gfporder); | |
1736 | ||
1737 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1738 | sub_zone_page_state(page_zone(page), | |
1739 | NR_SLAB_RECLAIMABLE, nr_freed); | |
1740 | else | |
1741 | sub_zone_page_state(page_zone(page), | |
1742 | NR_SLAB_UNRECLAIMABLE, nr_freed); | |
1743 | ||
1744 | BUG_ON(!PageSlab(page)); | |
1745 | __ClearPageSlabPfmemalloc(page); | |
1746 | __ClearPageSlab(page); | |
1747 | page_mapcount_reset(page); | |
1748 | page->mapping = NULL; | |
1749 | ||
1750 | if (current->reclaim_state) | |
1751 | current->reclaim_state->reclaimed_slab += nr_freed; | |
1752 | __free_pages(page, cachep->gfporder); | |
1753 | memcg_uncharge_slab(cachep, cachep->gfporder); | |
1754 | } | |
1755 | ||
1756 | static void kmem_rcu_free(struct rcu_head *head) | |
1757 | { | |
1758 | struct kmem_cache *cachep; | |
1759 | struct page *page; | |
1760 | ||
1761 | page = container_of(head, struct page, rcu_head); | |
1762 | cachep = page->slab_cache; | |
1763 | ||
1764 | kmem_freepages(cachep, page); | |
1765 | } | |
1766 | ||
1767 | #if DEBUG | |
1768 | ||
1769 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1770 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, | |
1771 | unsigned long caller) | |
1772 | { | |
1773 | int size = cachep->object_size; | |
1774 | ||
1775 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; | |
1776 | ||
1777 | if (size < 5 * sizeof(unsigned long)) | |
1778 | return; | |
1779 | ||
1780 | *addr++ = 0x12345678; | |
1781 | *addr++ = caller; | |
1782 | *addr++ = smp_processor_id(); | |
1783 | size -= 3 * sizeof(unsigned long); | |
1784 | { | |
1785 | unsigned long *sptr = &caller; | |
1786 | unsigned long svalue; | |
1787 | ||
1788 | while (!kstack_end(sptr)) { | |
1789 | svalue = *sptr++; | |
1790 | if (kernel_text_address(svalue)) { | |
1791 | *addr++ = svalue; | |
1792 | size -= sizeof(unsigned long); | |
1793 | if (size <= sizeof(unsigned long)) | |
1794 | break; | |
1795 | } | |
1796 | } | |
1797 | ||
1798 | } | |
1799 | *addr++ = 0x87654321; | |
1800 | } | |
1801 | #endif | |
1802 | ||
1803 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) | |
1804 | { | |
1805 | int size = cachep->object_size; | |
1806 | addr = &((char *)addr)[obj_offset(cachep)]; | |
1807 | ||
1808 | memset(addr, val, size); | |
1809 | *(unsigned char *)(addr + size - 1) = POISON_END; | |
1810 | } | |
1811 | ||
1812 | static void dump_line(char *data, int offset, int limit) | |
1813 | { | |
1814 | int i; | |
1815 | unsigned char error = 0; | |
1816 | int bad_count = 0; | |
1817 | ||
1818 | printk(KERN_ERR "%03x: ", offset); | |
1819 | for (i = 0; i < limit; i++) { | |
1820 | if (data[offset + i] != POISON_FREE) { | |
1821 | error = data[offset + i]; | |
1822 | bad_count++; | |
1823 | } | |
1824 | } | |
1825 | print_hex_dump(KERN_CONT, "", 0, 16, 1, | |
1826 | &data[offset], limit, 1); | |
1827 | ||
1828 | if (bad_count == 1) { | |
1829 | error ^= POISON_FREE; | |
1830 | if (!(error & (error - 1))) { | |
1831 | printk(KERN_ERR "Single bit error detected. Probably " | |
1832 | "bad RAM.\n"); | |
1833 | #ifdef CONFIG_X86 | |
1834 | printk(KERN_ERR "Run memtest86+ or a similar memory " | |
1835 | "test tool.\n"); | |
1836 | #else | |
1837 | printk(KERN_ERR "Run a memory test tool.\n"); | |
1838 | #endif | |
1839 | } | |
1840 | } | |
1841 | } | |
1842 | #endif | |
1843 | ||
1844 | #if DEBUG | |
1845 | ||
1846 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) | |
1847 | { | |
1848 | int i, size; | |
1849 | char *realobj; | |
1850 | ||
1851 | if (cachep->flags & SLAB_RED_ZONE) { | |
1852 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", | |
1853 | *dbg_redzone1(cachep, objp), | |
1854 | *dbg_redzone2(cachep, objp)); | |
1855 | } | |
1856 | ||
1857 | if (cachep->flags & SLAB_STORE_USER) { | |
1858 | printk(KERN_ERR "Last user: [<%p>](%pSR)\n", | |
1859 | *dbg_userword(cachep, objp), | |
1860 | *dbg_userword(cachep, objp)); | |
1861 | } | |
1862 | realobj = (char *)objp + obj_offset(cachep); | |
1863 | size = cachep->object_size; | |
1864 | for (i = 0; i < size && lines; i += 16, lines--) { | |
1865 | int limit; | |
1866 | limit = 16; | |
1867 | if (i + limit > size) | |
1868 | limit = size - i; | |
1869 | dump_line(realobj, i, limit); | |
1870 | } | |
1871 | } | |
1872 | ||
1873 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) | |
1874 | { | |
1875 | char *realobj; | |
1876 | int size, i; | |
1877 | int lines = 0; | |
1878 | ||
1879 | realobj = (char *)objp + obj_offset(cachep); | |
1880 | size = cachep->object_size; | |
1881 | ||
1882 | for (i = 0; i < size; i++) { | |
1883 | char exp = POISON_FREE; | |
1884 | if (i == size - 1) | |
1885 | exp = POISON_END; | |
1886 | if (realobj[i] != exp) { | |
1887 | int limit; | |
1888 | /* Mismatch ! */ | |
1889 | /* Print header */ | |
1890 | if (lines == 0) { | |
1891 | printk(KERN_ERR | |
1892 | "Slab corruption (%s): %s start=%p, len=%d\n", | |
1893 | print_tainted(), cachep->name, realobj, size); | |
1894 | print_objinfo(cachep, objp, 0); | |
1895 | } | |
1896 | /* Hexdump the affected line */ | |
1897 | i = (i / 16) * 16; | |
1898 | limit = 16; | |
1899 | if (i + limit > size) | |
1900 | limit = size - i; | |
1901 | dump_line(realobj, i, limit); | |
1902 | i += 16; | |
1903 | lines++; | |
1904 | /* Limit to 5 lines */ | |
1905 | if (lines > 5) | |
1906 | break; | |
1907 | } | |
1908 | } | |
1909 | if (lines != 0) { | |
1910 | /* Print some data about the neighboring objects, if they | |
1911 | * exist: | |
1912 | */ | |
1913 | struct page *page = virt_to_head_page(objp); | |
1914 | unsigned int objnr; | |
1915 | ||
1916 | objnr = obj_to_index(cachep, page, objp); | |
1917 | if (objnr) { | |
1918 | objp = index_to_obj(cachep, page, objnr - 1); | |
1919 | realobj = (char *)objp + obj_offset(cachep); | |
1920 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", | |
1921 | realobj, size); | |
1922 | print_objinfo(cachep, objp, 2); | |
1923 | } | |
1924 | if (objnr + 1 < cachep->num) { | |
1925 | objp = index_to_obj(cachep, page, objnr + 1); | |
1926 | realobj = (char *)objp + obj_offset(cachep); | |
1927 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", | |
1928 | realobj, size); | |
1929 | print_objinfo(cachep, objp, 2); | |
1930 | } | |
1931 | } | |
1932 | } | |
1933 | #endif | |
1934 | ||
1935 | #if DEBUG | |
1936 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, | |
1937 | struct page *page) | |
1938 | { | |
1939 | int i; | |
1940 | for (i = 0; i < cachep->num; i++) { | |
1941 | void *objp = index_to_obj(cachep, page, i); | |
1942 | ||
1943 | if (cachep->flags & SLAB_POISON) { | |
1944 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1945 | if (cachep->size % PAGE_SIZE == 0 && | |
1946 | OFF_SLAB(cachep)) | |
1947 | kernel_map_pages(virt_to_page(objp), | |
1948 | cachep->size / PAGE_SIZE, 1); | |
1949 | else | |
1950 | check_poison_obj(cachep, objp); | |
1951 | #else | |
1952 | check_poison_obj(cachep, objp); | |
1953 | #endif | |
1954 | } | |
1955 | if (cachep->flags & SLAB_RED_ZONE) { | |
1956 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
1957 | slab_error(cachep, "start of a freed object " | |
1958 | "was overwritten"); | |
1959 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
1960 | slab_error(cachep, "end of a freed object " | |
1961 | "was overwritten"); | |
1962 | } | |
1963 | } | |
1964 | } | |
1965 | #else | |
1966 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, | |
1967 | struct page *page) | |
1968 | { | |
1969 | } | |
1970 | #endif | |
1971 | ||
1972 | /** | |
1973 | * slab_destroy - destroy and release all objects in a slab | |
1974 | * @cachep: cache pointer being destroyed | |
1975 | * @page: page pointer being destroyed | |
1976 | * | |
1977 | * Destroy all the objs in a slab, and release the mem back to the system. | |
1978 | * Before calling the slab must have been unlinked from the cache. The | |
1979 | * cache-lock is not held/needed. | |
1980 | */ | |
1981 | static void slab_destroy(struct kmem_cache *cachep, struct page *page) | |
1982 | { | |
1983 | void *freelist; | |
1984 | ||
1985 | freelist = page->freelist; | |
1986 | slab_destroy_debugcheck(cachep, page); | |
1987 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { | |
1988 | struct rcu_head *head; | |
1989 | ||
1990 | /* | |
1991 | * RCU free overloads the RCU head over the LRU. | |
1992 | * slab_page has been overloeaded over the LRU, | |
1993 | * however it is not used from now on so that | |
1994 | * we can use it safely. | |
1995 | */ | |
1996 | head = (void *)&page->rcu_head; | |
1997 | call_rcu(head, kmem_rcu_free); | |
1998 | ||
1999 | } else { | |
2000 | kmem_freepages(cachep, page); | |
2001 | } | |
2002 | ||
2003 | /* | |
2004 | * From now on, we don't use freelist | |
2005 | * although actual page can be freed in rcu context | |
2006 | */ | |
2007 | if (OFF_SLAB(cachep)) | |
2008 | kmem_cache_free(cachep->freelist_cache, freelist); | |
2009 | } | |
2010 | ||
2011 | /** | |
2012 | * calculate_slab_order - calculate size (page order) of slabs | |
2013 | * @cachep: pointer to the cache that is being created | |
2014 | * @size: size of objects to be created in this cache. | |
2015 | * @align: required alignment for the objects. | |
2016 | * @flags: slab allocation flags | |
2017 | * | |
2018 | * Also calculates the number of objects per slab. | |
2019 | * | |
2020 | * This could be made much more intelligent. For now, try to avoid using | |
2021 | * high order pages for slabs. When the gfp() functions are more friendly | |
2022 | * towards high-order requests, this should be changed. | |
2023 | */ | |
2024 | static size_t calculate_slab_order(struct kmem_cache *cachep, | |
2025 | size_t size, size_t align, unsigned long flags) | |
2026 | { | |
2027 | unsigned long offslab_limit; | |
2028 | size_t left_over = 0; | |
2029 | int gfporder; | |
2030 | ||
2031 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { | |
2032 | unsigned int num; | |
2033 | size_t remainder; | |
2034 | ||
2035 | cache_estimate(gfporder, size, align, flags, &remainder, &num); | |
2036 | if (!num) | |
2037 | continue; | |
2038 | ||
2039 | /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */ | |
2040 | if (num > SLAB_OBJ_MAX_NUM) | |
2041 | break; | |
2042 | ||
2043 | if (flags & CFLGS_OFF_SLAB) { | |
2044 | /* | |
2045 | * Max number of objs-per-slab for caches which | |
2046 | * use off-slab slabs. Needed to avoid a possible | |
2047 | * looping condition in cache_grow(). | |
2048 | */ | |
2049 | offslab_limit = size; | |
2050 | offslab_limit /= sizeof(freelist_idx_t); | |
2051 | ||
2052 | if (num > offslab_limit) | |
2053 | break; | |
2054 | } | |
2055 | ||
2056 | /* Found something acceptable - save it away */ | |
2057 | cachep->num = num; | |
2058 | cachep->gfporder = gfporder; | |
2059 | left_over = remainder; | |
2060 | ||
2061 | /* | |
2062 | * A VFS-reclaimable slab tends to have most allocations | |
2063 | * as GFP_NOFS and we really don't want to have to be allocating | |
2064 | * higher-order pages when we are unable to shrink dcache. | |
2065 | */ | |
2066 | if (flags & SLAB_RECLAIM_ACCOUNT) | |
2067 | break; | |
2068 | ||
2069 | /* | |
2070 | * Large number of objects is good, but very large slabs are | |
2071 | * currently bad for the gfp()s. | |
2072 | */ | |
2073 | if (gfporder >= slab_max_order) | |
2074 | break; | |
2075 | ||
2076 | /* | |
2077 | * Acceptable internal fragmentation? | |
2078 | */ | |
2079 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) | |
2080 | break; | |
2081 | } | |
2082 | return left_over; | |
2083 | } | |
2084 | ||
2085 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) | |
2086 | { | |
2087 | if (slab_state >= FULL) | |
2088 | return enable_cpucache(cachep, gfp); | |
2089 | ||
2090 | if (slab_state == DOWN) { | |
2091 | /* | |
2092 | * Note: Creation of first cache (kmem_cache). | |
2093 | * The setup_node is taken care | |
2094 | * of by the caller of __kmem_cache_create | |
2095 | */ | |
2096 | cachep->array[smp_processor_id()] = &initarray_generic.cache; | |
2097 | slab_state = PARTIAL; | |
2098 | } else if (slab_state == PARTIAL) { | |
2099 | /* | |
2100 | * Note: the second kmem_cache_create must create the cache | |
2101 | * that's used by kmalloc(24), otherwise the creation of | |
2102 | * further caches will BUG(). | |
2103 | */ | |
2104 | cachep->array[smp_processor_id()] = &initarray_generic.cache; | |
2105 | ||
2106 | /* | |
2107 | * If the cache that's used by kmalloc(sizeof(kmem_cache_node)) is | |
2108 | * the second cache, then we need to set up all its node/, | |
2109 | * otherwise the creation of further caches will BUG(). | |
2110 | */ | |
2111 | set_up_node(cachep, SIZE_AC); | |
2112 | if (INDEX_AC == INDEX_NODE) | |
2113 | slab_state = PARTIAL_NODE; | |
2114 | else | |
2115 | slab_state = PARTIAL_ARRAYCACHE; | |
2116 | } else { | |
2117 | /* Remaining boot caches */ | |
2118 | cachep->array[smp_processor_id()] = | |
2119 | kmalloc(sizeof(struct arraycache_init), gfp); | |
2120 | ||
2121 | if (slab_state == PARTIAL_ARRAYCACHE) { | |
2122 | set_up_node(cachep, SIZE_NODE); | |
2123 | slab_state = PARTIAL_NODE; | |
2124 | } else { | |
2125 | int node; | |
2126 | for_each_online_node(node) { | |
2127 | cachep->node[node] = | |
2128 | kmalloc_node(sizeof(struct kmem_cache_node), | |
2129 | gfp, node); | |
2130 | BUG_ON(!cachep->node[node]); | |
2131 | kmem_cache_node_init(cachep->node[node]); | |
2132 | } | |
2133 | } | |
2134 | } | |
2135 | cachep->node[numa_mem_id()]->next_reap = | |
2136 | jiffies + REAPTIMEOUT_NODE + | |
2137 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; | |
2138 | ||
2139 | cpu_cache_get(cachep)->avail = 0; | |
2140 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; | |
2141 | cpu_cache_get(cachep)->batchcount = 1; | |
2142 | cpu_cache_get(cachep)->touched = 0; | |
2143 | cachep->batchcount = 1; | |
2144 | cachep->limit = BOOT_CPUCACHE_ENTRIES; | |
2145 | return 0; | |
2146 | } | |
2147 | ||
2148 | /** | |
2149 | * __kmem_cache_create - Create a cache. | |
2150 | * @cachep: cache management descriptor | |
2151 | * @flags: SLAB flags | |
2152 | * | |
2153 | * Returns a ptr to the cache on success, NULL on failure. | |
2154 | * Cannot be called within a int, but can be interrupted. | |
2155 | * The @ctor is run when new pages are allocated by the cache. | |
2156 | * | |
2157 | * The flags are | |
2158 | * | |
2159 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
2160 | * to catch references to uninitialised memory. | |
2161 | * | |
2162 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
2163 | * for buffer overruns. | |
2164 | * | |
2165 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
2166 | * cacheline. This can be beneficial if you're counting cycles as closely | |
2167 | * as davem. | |
2168 | */ | |
2169 | int | |
2170 | __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) | |
2171 | { | |
2172 | size_t left_over, freelist_size, ralign; | |
2173 | gfp_t gfp; | |
2174 | int err; | |
2175 | size_t size = cachep->size; | |
2176 | ||
2177 | #if DEBUG | |
2178 | #if FORCED_DEBUG | |
2179 | /* | |
2180 | * Enable redzoning and last user accounting, except for caches with | |
2181 | * large objects, if the increased size would increase the object size | |
2182 | * above the next power of two: caches with object sizes just above a | |
2183 | * power of two have a significant amount of internal fragmentation. | |
2184 | */ | |
2185 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + | |
2186 | 2 * sizeof(unsigned long long))) | |
2187 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; | |
2188 | if (!(flags & SLAB_DESTROY_BY_RCU)) | |
2189 | flags |= SLAB_POISON; | |
2190 | #endif | |
2191 | if (flags & SLAB_DESTROY_BY_RCU) | |
2192 | BUG_ON(flags & SLAB_POISON); | |
2193 | #endif | |
2194 | ||
2195 | /* | |
2196 | * Check that size is in terms of words. This is needed to avoid | |
2197 | * unaligned accesses for some archs when redzoning is used, and makes | |
2198 | * sure any on-slab bufctl's are also correctly aligned. | |
2199 | */ | |
2200 | if (size & (BYTES_PER_WORD - 1)) { | |
2201 | size += (BYTES_PER_WORD - 1); | |
2202 | size &= ~(BYTES_PER_WORD - 1); | |
2203 | } | |
2204 | ||
2205 | /* | |
2206 | * Redzoning and user store require word alignment or possibly larger. | |
2207 | * Note this will be overridden by architecture or caller mandated | |
2208 | * alignment if either is greater than BYTES_PER_WORD. | |
2209 | */ | |
2210 | if (flags & SLAB_STORE_USER) | |
2211 | ralign = BYTES_PER_WORD; | |
2212 | ||
2213 | if (flags & SLAB_RED_ZONE) { | |
2214 | ralign = REDZONE_ALIGN; | |
2215 | /* If redzoning, ensure that the second redzone is suitably | |
2216 | * aligned, by adjusting the object size accordingly. */ | |
2217 | size += REDZONE_ALIGN - 1; | |
2218 | size &= ~(REDZONE_ALIGN - 1); | |
2219 | } | |
2220 | ||
2221 | /* 3) caller mandated alignment */ | |
2222 | if (ralign < cachep->align) { | |
2223 | ralign = cachep->align; | |
2224 | } | |
2225 | /* disable debug if necessary */ | |
2226 | if (ralign > __alignof__(unsigned long long)) | |
2227 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); | |
2228 | /* | |
2229 | * 4) Store it. | |
2230 | */ | |
2231 | cachep->align = ralign; | |
2232 | ||
2233 | if (slab_is_available()) | |
2234 | gfp = GFP_KERNEL; | |
2235 | else | |
2236 | gfp = GFP_NOWAIT; | |
2237 | ||
2238 | setup_node_pointer(cachep); | |
2239 | #if DEBUG | |
2240 | ||
2241 | /* | |
2242 | * Both debugging options require word-alignment which is calculated | |
2243 | * into align above. | |
2244 | */ | |
2245 | if (flags & SLAB_RED_ZONE) { | |
2246 | /* add space for red zone words */ | |
2247 | cachep->obj_offset += sizeof(unsigned long long); | |
2248 | size += 2 * sizeof(unsigned long long); | |
2249 | } | |
2250 | if (flags & SLAB_STORE_USER) { | |
2251 | /* user store requires one word storage behind the end of | |
2252 | * the real object. But if the second red zone needs to be | |
2253 | * aligned to 64 bits, we must allow that much space. | |
2254 | */ | |
2255 | if (flags & SLAB_RED_ZONE) | |
2256 | size += REDZONE_ALIGN; | |
2257 | else | |
2258 | size += BYTES_PER_WORD; | |
2259 | } | |
2260 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) | |
2261 | if (size >= kmalloc_size(INDEX_NODE + 1) | |
2262 | && cachep->object_size > cache_line_size() | |
2263 | && ALIGN(size, cachep->align) < PAGE_SIZE) { | |
2264 | cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align); | |
2265 | size = PAGE_SIZE; | |
2266 | } | |
2267 | #endif | |
2268 | #endif | |
2269 | ||
2270 | /* | |
2271 | * Determine if the slab management is 'on' or 'off' slab. | |
2272 | * (bootstrapping cannot cope with offslab caches so don't do | |
2273 | * it too early on. Always use on-slab management when | |
2274 | * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) | |
2275 | */ | |
2276 | if ((size >= (PAGE_SIZE >> 5)) && !slab_early_init && | |
2277 | !(flags & SLAB_NOLEAKTRACE)) | |
2278 | /* | |
2279 | * Size is large, assume best to place the slab management obj | |
2280 | * off-slab (should allow better packing of objs). | |
2281 | */ | |
2282 | flags |= CFLGS_OFF_SLAB; | |
2283 | ||
2284 | size = ALIGN(size, cachep->align); | |
2285 | /* | |
2286 | * We should restrict the number of objects in a slab to implement | |
2287 | * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition. | |
2288 | */ | |
2289 | if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE) | |
2290 | size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align); | |
2291 | ||
2292 | left_over = calculate_slab_order(cachep, size, cachep->align, flags); | |
2293 | ||
2294 | if (!cachep->num) | |
2295 | return -E2BIG; | |
2296 | ||
2297 | freelist_size = | |
2298 | ALIGN(cachep->num * sizeof(freelist_idx_t), cachep->align); | |
2299 | ||
2300 | /* | |
2301 | * If the slab has been placed off-slab, and we have enough space then | |
2302 | * move it on-slab. This is at the expense of any extra colouring. | |
2303 | */ | |
2304 | if (flags & CFLGS_OFF_SLAB && left_over >= freelist_size) { | |
2305 | flags &= ~CFLGS_OFF_SLAB; | |
2306 | left_over -= freelist_size; | |
2307 | } | |
2308 | ||
2309 | if (flags & CFLGS_OFF_SLAB) { | |
2310 | /* really off slab. No need for manual alignment */ | |
2311 | freelist_size = cachep->num * sizeof(freelist_idx_t); | |
2312 | ||
2313 | #ifdef CONFIG_PAGE_POISONING | |
2314 | /* If we're going to use the generic kernel_map_pages() | |
2315 | * poisoning, then it's going to smash the contents of | |
2316 | * the redzone and userword anyhow, so switch them off. | |
2317 | */ | |
2318 | if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) | |
2319 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); | |
2320 | #endif | |
2321 | } | |
2322 | ||
2323 | cachep->colour_off = cache_line_size(); | |
2324 | /* Offset must be a multiple of the alignment. */ | |
2325 | if (cachep->colour_off < cachep->align) | |
2326 | cachep->colour_off = cachep->align; | |
2327 | cachep->colour = left_over / cachep->colour_off; | |
2328 | cachep->freelist_size = freelist_size; | |
2329 | cachep->flags = flags; | |
2330 | cachep->allocflags = __GFP_COMP; | |
2331 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) | |
2332 | cachep->allocflags |= GFP_DMA; | |
2333 | cachep->size = size; | |
2334 | cachep->reciprocal_buffer_size = reciprocal_value(size); | |
2335 | ||
2336 | if (flags & CFLGS_OFF_SLAB) { | |
2337 | cachep->freelist_cache = kmalloc_slab(freelist_size, 0u); | |
2338 | /* | |
2339 | * This is a possibility for one of the kmalloc_{dma,}_caches. | |
2340 | * But since we go off slab only for object size greater than | |
2341 | * PAGE_SIZE/8, and kmalloc_{dma,}_caches get created | |
2342 | * in ascending order,this should not happen at all. | |
2343 | * But leave a BUG_ON for some lucky dude. | |
2344 | */ | |
2345 | BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache)); | |
2346 | } | |
2347 | ||
2348 | err = setup_cpu_cache(cachep, gfp); | |
2349 | if (err) { | |
2350 | __kmem_cache_shutdown(cachep); | |
2351 | return err; | |
2352 | } | |
2353 | ||
2354 | if (flags & SLAB_DEBUG_OBJECTS) { | |
2355 | /* | |
2356 | * Would deadlock through slab_destroy()->call_rcu()-> | |
2357 | * debug_object_activate()->kmem_cache_alloc(). | |
2358 | */ | |
2359 | WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU); | |
2360 | ||
2361 | slab_set_debugobj_lock_classes(cachep); | |
2362 | } else if (!OFF_SLAB(cachep) && !(flags & SLAB_DESTROY_BY_RCU)) | |
2363 | on_slab_lock_classes(cachep); | |
2364 | ||
2365 | return 0; | |
2366 | } | |
2367 | ||
2368 | #if DEBUG | |
2369 | static void check_irq_off(void) | |
2370 | { | |
2371 | BUG_ON(!irqs_disabled()); | |
2372 | } | |
2373 | ||
2374 | static void check_irq_on(void) | |
2375 | { | |
2376 | BUG_ON(irqs_disabled()); | |
2377 | } | |
2378 | ||
2379 | static void check_spinlock_acquired(struct kmem_cache *cachep) | |
2380 | { | |
2381 | #ifdef CONFIG_SMP | |
2382 | check_irq_off(); | |
2383 | assert_spin_locked(&cachep->node[numa_mem_id()]->list_lock); | |
2384 | #endif | |
2385 | } | |
2386 | ||
2387 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) | |
2388 | { | |
2389 | #ifdef CONFIG_SMP | |
2390 | check_irq_off(); | |
2391 | assert_spin_locked(&cachep->node[node]->list_lock); | |
2392 | #endif | |
2393 | } | |
2394 | ||
2395 | #else | |
2396 | #define check_irq_off() do { } while(0) | |
2397 | #define check_irq_on() do { } while(0) | |
2398 | #define check_spinlock_acquired(x) do { } while(0) | |
2399 | #define check_spinlock_acquired_node(x, y) do { } while(0) | |
2400 | #endif | |
2401 | ||
2402 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, | |
2403 | struct array_cache *ac, | |
2404 | int force, int node); | |
2405 | ||
2406 | static void do_drain(void *arg) | |
2407 | { | |
2408 | struct kmem_cache *cachep = arg; | |
2409 | struct array_cache *ac; | |
2410 | int node = numa_mem_id(); | |
2411 | ||
2412 | check_irq_off(); | |
2413 | ac = cpu_cache_get(cachep); | |
2414 | spin_lock(&cachep->node[node]->list_lock); | |
2415 | free_block(cachep, ac->entry, ac->avail, node); | |
2416 | spin_unlock(&cachep->node[node]->list_lock); | |
2417 | ac->avail = 0; | |
2418 | } | |
2419 | ||
2420 | static void drain_cpu_caches(struct kmem_cache *cachep) | |
2421 | { | |
2422 | struct kmem_cache_node *n; | |
2423 | int node; | |
2424 | ||
2425 | on_each_cpu(do_drain, cachep, 1); | |
2426 | check_irq_on(); | |
2427 | for_each_online_node(node) { | |
2428 | n = cachep->node[node]; | |
2429 | if (n && n->alien) | |
2430 | drain_alien_cache(cachep, n->alien); | |
2431 | } | |
2432 | ||
2433 | for_each_online_node(node) { | |
2434 | n = cachep->node[node]; | |
2435 | if (n) | |
2436 | drain_array(cachep, n, n->shared, 1, node); | |
2437 | } | |
2438 | } | |
2439 | ||
2440 | /* | |
2441 | * Remove slabs from the list of free slabs. | |
2442 | * Specify the number of slabs to drain in tofree. | |
2443 | * | |
2444 | * Returns the actual number of slabs released. | |
2445 | */ | |
2446 | static int drain_freelist(struct kmem_cache *cache, | |
2447 | struct kmem_cache_node *n, int tofree) | |
2448 | { | |
2449 | struct list_head *p; | |
2450 | int nr_freed; | |
2451 | struct page *page; | |
2452 | ||
2453 | nr_freed = 0; | |
2454 | while (nr_freed < tofree && !list_empty(&n->slabs_free)) { | |
2455 | ||
2456 | spin_lock_irq(&n->list_lock); | |
2457 | p = n->slabs_free.prev; | |
2458 | if (p == &n->slabs_free) { | |
2459 | spin_unlock_irq(&n->list_lock); | |
2460 | goto out; | |
2461 | } | |
2462 | ||
2463 | page = list_entry(p, struct page, lru); | |
2464 | #if DEBUG | |
2465 | BUG_ON(page->active); | |
2466 | #endif | |
2467 | list_del(&page->lru); | |
2468 | /* | |
2469 | * Safe to drop the lock. The slab is no longer linked | |
2470 | * to the cache. | |
2471 | */ | |
2472 | n->free_objects -= cache->num; | |
2473 | spin_unlock_irq(&n->list_lock); | |
2474 | slab_destroy(cache, page); | |
2475 | nr_freed++; | |
2476 | } | |
2477 | out: | |
2478 | return nr_freed; | |
2479 | } | |
2480 | ||
2481 | int __kmem_cache_shrink(struct kmem_cache *cachep) | |
2482 | { | |
2483 | int ret = 0, i = 0; | |
2484 | struct kmem_cache_node *n; | |
2485 | ||
2486 | drain_cpu_caches(cachep); | |
2487 | ||
2488 | check_irq_on(); | |
2489 | for_each_online_node(i) { | |
2490 | n = cachep->node[i]; | |
2491 | if (!n) | |
2492 | continue; | |
2493 | ||
2494 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); | |
2495 | ||
2496 | ret += !list_empty(&n->slabs_full) || | |
2497 | !list_empty(&n->slabs_partial); | |
2498 | } | |
2499 | return (ret ? 1 : 0); | |
2500 | } | |
2501 | ||
2502 | int __kmem_cache_shutdown(struct kmem_cache *cachep) | |
2503 | { | |
2504 | int i; | |
2505 | struct kmem_cache_node *n; | |
2506 | int rc = __kmem_cache_shrink(cachep); | |
2507 | ||
2508 | if (rc) | |
2509 | return rc; | |
2510 | ||
2511 | for_each_online_cpu(i) | |
2512 | kfree(cachep->array[i]); | |
2513 | ||
2514 | /* NUMA: free the node structures */ | |
2515 | for_each_online_node(i) { | |
2516 | n = cachep->node[i]; | |
2517 | if (n) { | |
2518 | kfree(n->shared); | |
2519 | free_alien_cache(n->alien); | |
2520 | kfree(n); | |
2521 | } | |
2522 | } | |
2523 | return 0; | |
2524 | } | |
2525 | ||
2526 | /* | |
2527 | * Get the memory for a slab management obj. | |
2528 | * | |
2529 | * For a slab cache when the slab descriptor is off-slab, the | |
2530 | * slab descriptor can't come from the same cache which is being created, | |
2531 | * Because if it is the case, that means we defer the creation of | |
2532 | * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point. | |
2533 | * And we eventually call down to __kmem_cache_create(), which | |
2534 | * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one. | |
2535 | * This is a "chicken-and-egg" problem. | |
2536 | * | |
2537 | * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches, | |
2538 | * which are all initialized during kmem_cache_init(). | |
2539 | */ | |
2540 | static void *alloc_slabmgmt(struct kmem_cache *cachep, | |
2541 | struct page *page, int colour_off, | |
2542 | gfp_t local_flags, int nodeid) | |
2543 | { | |
2544 | void *freelist; | |
2545 | void *addr = page_address(page); | |
2546 | ||
2547 | if (OFF_SLAB(cachep)) { | |
2548 | /* Slab management obj is off-slab. */ | |
2549 | freelist = kmem_cache_alloc_node(cachep->freelist_cache, | |
2550 | local_flags, nodeid); | |
2551 | if (!freelist) | |
2552 | return NULL; | |
2553 | } else { | |
2554 | freelist = addr + colour_off; | |
2555 | colour_off += cachep->freelist_size; | |
2556 | } | |
2557 | page->active = 0; | |
2558 | page->s_mem = addr + colour_off; | |
2559 | return freelist; | |
2560 | } | |
2561 | ||
2562 | static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx) | |
2563 | { | |
2564 | return ((freelist_idx_t *)page->freelist)[idx]; | |
2565 | } | |
2566 | ||
2567 | static inline void set_free_obj(struct page *page, | |
2568 | unsigned int idx, freelist_idx_t val) | |
2569 | { | |
2570 | ((freelist_idx_t *)(page->freelist))[idx] = val; | |
2571 | } | |
2572 | ||
2573 | static void cache_init_objs(struct kmem_cache *cachep, | |
2574 | struct page *page) | |
2575 | { | |
2576 | int i; | |
2577 | ||
2578 | for (i = 0; i < cachep->num; i++) { | |
2579 | void *objp = index_to_obj(cachep, page, i); | |
2580 | #if DEBUG | |
2581 | /* need to poison the objs? */ | |
2582 | if (cachep->flags & SLAB_POISON) | |
2583 | poison_obj(cachep, objp, POISON_FREE); | |
2584 | if (cachep->flags & SLAB_STORE_USER) | |
2585 | *dbg_userword(cachep, objp) = NULL; | |
2586 | ||
2587 | if (cachep->flags & SLAB_RED_ZONE) { | |
2588 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2589 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2590 | } | |
2591 | /* | |
2592 | * Constructors are not allowed to allocate memory from the same | |
2593 | * cache which they are a constructor for. Otherwise, deadlock. | |
2594 | * They must also be threaded. | |
2595 | */ | |
2596 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) | |
2597 | cachep->ctor(objp + obj_offset(cachep)); | |
2598 | ||
2599 | if (cachep->flags & SLAB_RED_ZONE) { | |
2600 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
2601 | slab_error(cachep, "constructor overwrote the" | |
2602 | " end of an object"); | |
2603 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
2604 | slab_error(cachep, "constructor overwrote the" | |
2605 | " start of an object"); | |
2606 | } | |
2607 | if ((cachep->size % PAGE_SIZE) == 0 && | |
2608 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) | |
2609 | kernel_map_pages(virt_to_page(objp), | |
2610 | cachep->size / PAGE_SIZE, 0); | |
2611 | #else | |
2612 | if (cachep->ctor) | |
2613 | cachep->ctor(objp); | |
2614 | #endif | |
2615 | set_free_obj(page, i, i); | |
2616 | } | |
2617 | } | |
2618 | ||
2619 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) | |
2620 | { | |
2621 | if (CONFIG_ZONE_DMA_FLAG) { | |
2622 | if (flags & GFP_DMA) | |
2623 | BUG_ON(!(cachep->allocflags & GFP_DMA)); | |
2624 | else | |
2625 | BUG_ON(cachep->allocflags & GFP_DMA); | |
2626 | } | |
2627 | } | |
2628 | ||
2629 | static void *slab_get_obj(struct kmem_cache *cachep, struct page *page, | |
2630 | int nodeid) | |
2631 | { | |
2632 | void *objp; | |
2633 | ||
2634 | objp = index_to_obj(cachep, page, get_free_obj(page, page->active)); | |
2635 | page->active++; | |
2636 | #if DEBUG | |
2637 | WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); | |
2638 | #endif | |
2639 | ||
2640 | return objp; | |
2641 | } | |
2642 | ||
2643 | static void slab_put_obj(struct kmem_cache *cachep, struct page *page, | |
2644 | void *objp, int nodeid) | |
2645 | { | |
2646 | unsigned int objnr = obj_to_index(cachep, page, objp); | |
2647 | #if DEBUG | |
2648 | unsigned int i; | |
2649 | ||
2650 | /* Verify that the slab belongs to the intended node */ | |
2651 | WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); | |
2652 | ||
2653 | /* Verify double free bug */ | |
2654 | for (i = page->active; i < cachep->num; i++) { | |
2655 | if (get_free_obj(page, i) == objnr) { | |
2656 | printk(KERN_ERR "slab: double free detected in cache " | |
2657 | "'%s', objp %p\n", cachep->name, objp); | |
2658 | BUG(); | |
2659 | } | |
2660 | } | |
2661 | #endif | |
2662 | page->active--; | |
2663 | set_free_obj(page, page->active, objnr); | |
2664 | } | |
2665 | ||
2666 | /* | |
2667 | * Map pages beginning at addr to the given cache and slab. This is required | |
2668 | * for the slab allocator to be able to lookup the cache and slab of a | |
2669 | * virtual address for kfree, ksize, and slab debugging. | |
2670 | */ | |
2671 | static void slab_map_pages(struct kmem_cache *cache, struct page *page, | |
2672 | void *freelist) | |
2673 | { | |
2674 | page->slab_cache = cache; | |
2675 | page->freelist = freelist; | |
2676 | } | |
2677 | ||
2678 | /* | |
2679 | * Grow (by 1) the number of slabs within a cache. This is called by | |
2680 | * kmem_cache_alloc() when there are no active objs left in a cache. | |
2681 | */ | |
2682 | static int cache_grow(struct kmem_cache *cachep, | |
2683 | gfp_t flags, int nodeid, struct page *page) | |
2684 | { | |
2685 | void *freelist; | |
2686 | size_t offset; | |
2687 | gfp_t local_flags; | |
2688 | struct kmem_cache_node *n; | |
2689 | ||
2690 | /* | |
2691 | * Be lazy and only check for valid flags here, keeping it out of the | |
2692 | * critical path in kmem_cache_alloc(). | |
2693 | */ | |
2694 | BUG_ON(flags & GFP_SLAB_BUG_MASK); | |
2695 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); | |
2696 | ||
2697 | /* Take the node list lock to change the colour_next on this node */ | |
2698 | check_irq_off(); | |
2699 | n = cachep->node[nodeid]; | |
2700 | spin_lock(&n->list_lock); | |
2701 | ||
2702 | /* Get colour for the slab, and cal the next value. */ | |
2703 | offset = n->colour_next; | |
2704 | n->colour_next++; | |
2705 | if (n->colour_next >= cachep->colour) | |
2706 | n->colour_next = 0; | |
2707 | spin_unlock(&n->list_lock); | |
2708 | ||
2709 | offset *= cachep->colour_off; | |
2710 | ||
2711 | if (local_flags & __GFP_WAIT) | |
2712 | local_irq_enable(); | |
2713 | ||
2714 | /* | |
2715 | * The test for missing atomic flag is performed here, rather than | |
2716 | * the more obvious place, simply to reduce the critical path length | |
2717 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they | |
2718 | * will eventually be caught here (where it matters). | |
2719 | */ | |
2720 | kmem_flagcheck(cachep, flags); | |
2721 | ||
2722 | /* | |
2723 | * Get mem for the objs. Attempt to allocate a physical page from | |
2724 | * 'nodeid'. | |
2725 | */ | |
2726 | if (!page) | |
2727 | page = kmem_getpages(cachep, local_flags, nodeid); | |
2728 | if (!page) | |
2729 | goto failed; | |
2730 | ||
2731 | /* Get slab management. */ | |
2732 | freelist = alloc_slabmgmt(cachep, page, offset, | |
2733 | local_flags & ~GFP_CONSTRAINT_MASK, nodeid); | |
2734 | if (!freelist) | |
2735 | goto opps1; | |
2736 | ||
2737 | slab_map_pages(cachep, page, freelist); | |
2738 | ||
2739 | cache_init_objs(cachep, page); | |
2740 | ||
2741 | if (local_flags & __GFP_WAIT) | |
2742 | local_irq_disable(); | |
2743 | check_irq_off(); | |
2744 | spin_lock(&n->list_lock); | |
2745 | ||
2746 | /* Make slab active. */ | |
2747 | list_add_tail(&page->lru, &(n->slabs_free)); | |
2748 | STATS_INC_GROWN(cachep); | |
2749 | n->free_objects += cachep->num; | |
2750 | spin_unlock(&n->list_lock); | |
2751 | return 1; | |
2752 | opps1: | |
2753 | kmem_freepages(cachep, page); | |
2754 | failed: | |
2755 | if (local_flags & __GFP_WAIT) | |
2756 | local_irq_disable(); | |
2757 | return 0; | |
2758 | } | |
2759 | ||
2760 | #if DEBUG | |
2761 | ||
2762 | /* | |
2763 | * Perform extra freeing checks: | |
2764 | * - detect bad pointers. | |
2765 | * - POISON/RED_ZONE checking | |
2766 | */ | |
2767 | static void kfree_debugcheck(const void *objp) | |
2768 | { | |
2769 | if (!virt_addr_valid(objp)) { | |
2770 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", | |
2771 | (unsigned long)objp); | |
2772 | BUG(); | |
2773 | } | |
2774 | } | |
2775 | ||
2776 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) | |
2777 | { | |
2778 | unsigned long long redzone1, redzone2; | |
2779 | ||
2780 | redzone1 = *dbg_redzone1(cache, obj); | |
2781 | redzone2 = *dbg_redzone2(cache, obj); | |
2782 | ||
2783 | /* | |
2784 | * Redzone is ok. | |
2785 | */ | |
2786 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) | |
2787 | return; | |
2788 | ||
2789 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) | |
2790 | slab_error(cache, "double free detected"); | |
2791 | else | |
2792 | slab_error(cache, "memory outside object was overwritten"); | |
2793 | ||
2794 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", | |
2795 | obj, redzone1, redzone2); | |
2796 | } | |
2797 | ||
2798 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, | |
2799 | unsigned long caller) | |
2800 | { | |
2801 | unsigned int objnr; | |
2802 | struct page *page; | |
2803 | ||
2804 | BUG_ON(virt_to_cache(objp) != cachep); | |
2805 | ||
2806 | objp -= obj_offset(cachep); | |
2807 | kfree_debugcheck(objp); | |
2808 | page = virt_to_head_page(objp); | |
2809 | ||
2810 | if (cachep->flags & SLAB_RED_ZONE) { | |
2811 | verify_redzone_free(cachep, objp); | |
2812 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2813 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2814 | } | |
2815 | if (cachep->flags & SLAB_STORE_USER) | |
2816 | *dbg_userword(cachep, objp) = (void *)caller; | |
2817 | ||
2818 | objnr = obj_to_index(cachep, page, objp); | |
2819 | ||
2820 | BUG_ON(objnr >= cachep->num); | |
2821 | BUG_ON(objp != index_to_obj(cachep, page, objnr)); | |
2822 | ||
2823 | if (cachep->flags & SLAB_POISON) { | |
2824 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
2825 | if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { | |
2826 | store_stackinfo(cachep, objp, caller); | |
2827 | kernel_map_pages(virt_to_page(objp), | |
2828 | cachep->size / PAGE_SIZE, 0); | |
2829 | } else { | |
2830 | poison_obj(cachep, objp, POISON_FREE); | |
2831 | } | |
2832 | #else | |
2833 | poison_obj(cachep, objp, POISON_FREE); | |
2834 | #endif | |
2835 | } | |
2836 | return objp; | |
2837 | } | |
2838 | ||
2839 | #else | |
2840 | #define kfree_debugcheck(x) do { } while(0) | |
2841 | #define cache_free_debugcheck(x,objp,z) (objp) | |
2842 | #endif | |
2843 | ||
2844 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, | |
2845 | bool force_refill) | |
2846 | { | |
2847 | int batchcount; | |
2848 | struct kmem_cache_node *n; | |
2849 | struct array_cache *ac; | |
2850 | int node; | |
2851 | ||
2852 | check_irq_off(); | |
2853 | node = numa_mem_id(); | |
2854 | if (unlikely(force_refill)) | |
2855 | goto force_grow; | |
2856 | retry: | |
2857 | ac = cpu_cache_get(cachep); | |
2858 | batchcount = ac->batchcount; | |
2859 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { | |
2860 | /* | |
2861 | * If there was little recent activity on this cache, then | |
2862 | * perform only a partial refill. Otherwise we could generate | |
2863 | * refill bouncing. | |
2864 | */ | |
2865 | batchcount = BATCHREFILL_LIMIT; | |
2866 | } | |
2867 | n = cachep->node[node]; | |
2868 | ||
2869 | BUG_ON(ac->avail > 0 || !n); | |
2870 | spin_lock(&n->list_lock); | |
2871 | ||
2872 | /* See if we can refill from the shared array */ | |
2873 | if (n->shared && transfer_objects(ac, n->shared, batchcount)) { | |
2874 | n->shared->touched = 1; | |
2875 | goto alloc_done; | |
2876 | } | |
2877 | ||
2878 | while (batchcount > 0) { | |
2879 | struct list_head *entry; | |
2880 | struct page *page; | |
2881 | /* Get slab alloc is to come from. */ | |
2882 | entry = n->slabs_partial.next; | |
2883 | if (entry == &n->slabs_partial) { | |
2884 | n->free_touched = 1; | |
2885 | entry = n->slabs_free.next; | |
2886 | if (entry == &n->slabs_free) | |
2887 | goto must_grow; | |
2888 | } | |
2889 | ||
2890 | page = list_entry(entry, struct page, lru); | |
2891 | check_spinlock_acquired(cachep); | |
2892 | ||
2893 | /* | |
2894 | * The slab was either on partial or free list so | |
2895 | * there must be at least one object available for | |
2896 | * allocation. | |
2897 | */ | |
2898 | BUG_ON(page->active >= cachep->num); | |
2899 | ||
2900 | while (page->active < cachep->num && batchcount--) { | |
2901 | STATS_INC_ALLOCED(cachep); | |
2902 | STATS_INC_ACTIVE(cachep); | |
2903 | STATS_SET_HIGH(cachep); | |
2904 | ||
2905 | ac_put_obj(cachep, ac, slab_get_obj(cachep, page, | |
2906 | node)); | |
2907 | } | |
2908 | ||
2909 | /* move slabp to correct slabp list: */ | |
2910 | list_del(&page->lru); | |
2911 | if (page->active == cachep->num) | |
2912 | list_add(&page->lru, &n->slabs_full); | |
2913 | else | |
2914 | list_add(&page->lru, &n->slabs_partial); | |
2915 | } | |
2916 | ||
2917 | must_grow: | |
2918 | n->free_objects -= ac->avail; | |
2919 | alloc_done: | |
2920 | spin_unlock(&n->list_lock); | |
2921 | ||
2922 | if (unlikely(!ac->avail)) { | |
2923 | int x; | |
2924 | force_grow: | |
2925 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); | |
2926 | ||
2927 | /* cache_grow can reenable interrupts, then ac could change. */ | |
2928 | ac = cpu_cache_get(cachep); | |
2929 | node = numa_mem_id(); | |
2930 | ||
2931 | /* no objects in sight? abort */ | |
2932 | if (!x && (ac->avail == 0 || force_refill)) | |
2933 | return NULL; | |
2934 | ||
2935 | if (!ac->avail) /* objects refilled by interrupt? */ | |
2936 | goto retry; | |
2937 | } | |
2938 | ac->touched = 1; | |
2939 | ||
2940 | return ac_get_obj(cachep, ac, flags, force_refill); | |
2941 | } | |
2942 | ||
2943 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, | |
2944 | gfp_t flags) | |
2945 | { | |
2946 | might_sleep_if(flags & __GFP_WAIT); | |
2947 | #if DEBUG | |
2948 | kmem_flagcheck(cachep, flags); | |
2949 | #endif | |
2950 | } | |
2951 | ||
2952 | #if DEBUG | |
2953 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, | |
2954 | gfp_t flags, void *objp, unsigned long caller) | |
2955 | { | |
2956 | if (!objp) | |
2957 | return objp; | |
2958 | if (cachep->flags & SLAB_POISON) { | |
2959 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
2960 | if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) | |
2961 | kernel_map_pages(virt_to_page(objp), | |
2962 | cachep->size / PAGE_SIZE, 1); | |
2963 | else | |
2964 | check_poison_obj(cachep, objp); | |
2965 | #else | |
2966 | check_poison_obj(cachep, objp); | |
2967 | #endif | |
2968 | poison_obj(cachep, objp, POISON_INUSE); | |
2969 | } | |
2970 | if (cachep->flags & SLAB_STORE_USER) | |
2971 | *dbg_userword(cachep, objp) = (void *)caller; | |
2972 | ||
2973 | if (cachep->flags & SLAB_RED_ZONE) { | |
2974 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || | |
2975 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { | |
2976 | slab_error(cachep, "double free, or memory outside" | |
2977 | " object was overwritten"); | |
2978 | printk(KERN_ERR | |
2979 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", | |
2980 | objp, *dbg_redzone1(cachep, objp), | |
2981 | *dbg_redzone2(cachep, objp)); | |
2982 | } | |
2983 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; | |
2984 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; | |
2985 | } | |
2986 | objp += obj_offset(cachep); | |
2987 | if (cachep->ctor && cachep->flags & SLAB_POISON) | |
2988 | cachep->ctor(objp); | |
2989 | if (ARCH_SLAB_MINALIGN && | |
2990 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { | |
2991 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", | |
2992 | objp, (int)ARCH_SLAB_MINALIGN); | |
2993 | } | |
2994 | return objp; | |
2995 | } | |
2996 | #else | |
2997 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) | |
2998 | #endif | |
2999 | ||
3000 | static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) | |
3001 | { | |
3002 | if (cachep == kmem_cache) | |
3003 | return false; | |
3004 | ||
3005 | return should_failslab(cachep->object_size, flags, cachep->flags); | |
3006 | } | |
3007 | ||
3008 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3009 | { | |
3010 | void *objp; | |
3011 | struct array_cache *ac; | |
3012 | bool force_refill = false; | |
3013 | ||
3014 | check_irq_off(); | |
3015 | ||
3016 | ac = cpu_cache_get(cachep); | |
3017 | if (likely(ac->avail)) { | |
3018 | ac->touched = 1; | |
3019 | objp = ac_get_obj(cachep, ac, flags, false); | |
3020 | ||
3021 | /* | |
3022 | * Allow for the possibility all avail objects are not allowed | |
3023 | * by the current flags | |
3024 | */ | |
3025 | if (objp) { | |
3026 | STATS_INC_ALLOCHIT(cachep); | |
3027 | goto out; | |
3028 | } | |
3029 | force_refill = true; | |
3030 | } | |
3031 | ||
3032 | STATS_INC_ALLOCMISS(cachep); | |
3033 | objp = cache_alloc_refill(cachep, flags, force_refill); | |
3034 | /* | |
3035 | * the 'ac' may be updated by cache_alloc_refill(), | |
3036 | * and kmemleak_erase() requires its correct value. | |
3037 | */ | |
3038 | ac = cpu_cache_get(cachep); | |
3039 | ||
3040 | out: | |
3041 | /* | |
3042 | * To avoid a false negative, if an object that is in one of the | |
3043 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't | |
3044 | * treat the array pointers as a reference to the object. | |
3045 | */ | |
3046 | if (objp) | |
3047 | kmemleak_erase(&ac->entry[ac->avail]); | |
3048 | return objp; | |
3049 | } | |
3050 | ||
3051 | #ifdef CONFIG_NUMA | |
3052 | /* | |
3053 | * Try allocating on another node if PF_SPREAD_SLAB is a mempolicy is set. | |
3054 | * | |
3055 | * If we are in_interrupt, then process context, including cpusets and | |
3056 | * mempolicy, may not apply and should not be used for allocation policy. | |
3057 | */ | |
3058 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3059 | { | |
3060 | int nid_alloc, nid_here; | |
3061 | ||
3062 | if (in_interrupt() || (flags & __GFP_THISNODE)) | |
3063 | return NULL; | |
3064 | nid_alloc = nid_here = numa_mem_id(); | |
3065 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) | |
3066 | nid_alloc = cpuset_slab_spread_node(); | |
3067 | else if (current->mempolicy) | |
3068 | nid_alloc = mempolicy_slab_node(); | |
3069 | if (nid_alloc != nid_here) | |
3070 | return ____cache_alloc_node(cachep, flags, nid_alloc); | |
3071 | return NULL; | |
3072 | } | |
3073 | ||
3074 | /* | |
3075 | * Fallback function if there was no memory available and no objects on a | |
3076 | * certain node and fall back is permitted. First we scan all the | |
3077 | * available node for available objects. If that fails then we | |
3078 | * perform an allocation without specifying a node. This allows the page | |
3079 | * allocator to do its reclaim / fallback magic. We then insert the | |
3080 | * slab into the proper nodelist and then allocate from it. | |
3081 | */ | |
3082 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) | |
3083 | { | |
3084 | struct zonelist *zonelist; | |
3085 | gfp_t local_flags; | |
3086 | struct zoneref *z; | |
3087 | struct zone *zone; | |
3088 | enum zone_type high_zoneidx = gfp_zone(flags); | |
3089 | void *obj = NULL; | |
3090 | int nid; | |
3091 | unsigned int cpuset_mems_cookie; | |
3092 | ||
3093 | if (flags & __GFP_THISNODE) | |
3094 | return NULL; | |
3095 | ||
3096 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); | |
3097 | ||
3098 | retry_cpuset: | |
3099 | cpuset_mems_cookie = read_mems_allowed_begin(); | |
3100 | zonelist = node_zonelist(mempolicy_slab_node(), flags); | |
3101 | ||
3102 | retry: | |
3103 | /* | |
3104 | * Look through allowed nodes for objects available | |
3105 | * from existing per node queues. | |
3106 | */ | |
3107 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { | |
3108 | nid = zone_to_nid(zone); | |
3109 | ||
3110 | if (cpuset_zone_allowed_hardwall(zone, flags) && | |
3111 | cache->node[nid] && | |
3112 | cache->node[nid]->free_objects) { | |
3113 | obj = ____cache_alloc_node(cache, | |
3114 | flags | GFP_THISNODE, nid); | |
3115 | if (obj) | |
3116 | break; | |
3117 | } | |
3118 | } | |
3119 | ||
3120 | if (!obj) { | |
3121 | /* | |
3122 | * This allocation will be performed within the constraints | |
3123 | * of the current cpuset / memory policy requirements. | |
3124 | * We may trigger various forms of reclaim on the allowed | |
3125 | * set and go into memory reserves if necessary. | |
3126 | */ | |
3127 | struct page *page; | |
3128 | ||
3129 | if (local_flags & __GFP_WAIT) | |
3130 | local_irq_enable(); | |
3131 | kmem_flagcheck(cache, flags); | |
3132 | page = kmem_getpages(cache, local_flags, numa_mem_id()); | |
3133 | if (local_flags & __GFP_WAIT) | |
3134 | local_irq_disable(); | |
3135 | if (page) { | |
3136 | /* | |
3137 | * Insert into the appropriate per node queues | |
3138 | */ | |
3139 | nid = page_to_nid(page); | |
3140 | if (cache_grow(cache, flags, nid, page)) { | |
3141 | obj = ____cache_alloc_node(cache, | |
3142 | flags | GFP_THISNODE, nid); | |
3143 | if (!obj) | |
3144 | /* | |
3145 | * Another processor may allocate the | |
3146 | * objects in the slab since we are | |
3147 | * not holding any locks. | |
3148 | */ | |
3149 | goto retry; | |
3150 | } else { | |
3151 | /* cache_grow already freed obj */ | |
3152 | obj = NULL; | |
3153 | } | |
3154 | } | |
3155 | } | |
3156 | ||
3157 | if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie))) | |
3158 | goto retry_cpuset; | |
3159 | return obj; | |
3160 | } | |
3161 | ||
3162 | /* | |
3163 | * A interface to enable slab creation on nodeid | |
3164 | */ | |
3165 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, | |
3166 | int nodeid) | |
3167 | { | |
3168 | struct list_head *entry; | |
3169 | struct page *page; | |
3170 | struct kmem_cache_node *n; | |
3171 | void *obj; | |
3172 | int x; | |
3173 | ||
3174 | VM_BUG_ON(nodeid > num_online_nodes()); | |
3175 | n = cachep->node[nodeid]; | |
3176 | BUG_ON(!n); | |
3177 | ||
3178 | retry: | |
3179 | check_irq_off(); | |
3180 | spin_lock(&n->list_lock); | |
3181 | entry = n->slabs_partial.next; | |
3182 | if (entry == &n->slabs_partial) { | |
3183 | n->free_touched = 1; | |
3184 | entry = n->slabs_free.next; | |
3185 | if (entry == &n->slabs_free) | |
3186 | goto must_grow; | |
3187 | } | |
3188 | ||
3189 | page = list_entry(entry, struct page, lru); | |
3190 | check_spinlock_acquired_node(cachep, nodeid); | |
3191 | ||
3192 | STATS_INC_NODEALLOCS(cachep); | |
3193 | STATS_INC_ACTIVE(cachep); | |
3194 | STATS_SET_HIGH(cachep); | |
3195 | ||
3196 | BUG_ON(page->active == cachep->num); | |
3197 | ||
3198 | obj = slab_get_obj(cachep, page, nodeid); | |
3199 | n->free_objects--; | |
3200 | /* move slabp to correct slabp list: */ | |
3201 | list_del(&page->lru); | |
3202 | ||
3203 | if (page->active == cachep->num) | |
3204 | list_add(&page->lru, &n->slabs_full); | |
3205 | else | |
3206 | list_add(&page->lru, &n->slabs_partial); | |
3207 | ||
3208 | spin_unlock(&n->list_lock); | |
3209 | goto done; | |
3210 | ||
3211 | must_grow: | |
3212 | spin_unlock(&n->list_lock); | |
3213 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); | |
3214 | if (x) | |
3215 | goto retry; | |
3216 | ||
3217 | return fallback_alloc(cachep, flags); | |
3218 | ||
3219 | done: | |
3220 | return obj; | |
3221 | } | |
3222 | ||
3223 | static __always_inline void * | |
3224 | slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, | |
3225 | unsigned long caller) | |
3226 | { | |
3227 | unsigned long save_flags; | |
3228 | void *ptr; | |
3229 | int slab_node = numa_mem_id(); | |
3230 | ||
3231 | flags &= gfp_allowed_mask; | |
3232 | ||
3233 | lockdep_trace_alloc(flags); | |
3234 | ||
3235 | if (slab_should_failslab(cachep, flags)) | |
3236 | return NULL; | |
3237 | ||
3238 | cachep = memcg_kmem_get_cache(cachep, flags); | |
3239 | ||
3240 | cache_alloc_debugcheck_before(cachep, flags); | |
3241 | local_irq_save(save_flags); | |
3242 | ||
3243 | if (nodeid == NUMA_NO_NODE) | |
3244 | nodeid = slab_node; | |
3245 | ||
3246 | if (unlikely(!cachep->node[nodeid])) { | |
3247 | /* Node not bootstrapped yet */ | |
3248 | ptr = fallback_alloc(cachep, flags); | |
3249 | goto out; | |
3250 | } | |
3251 | ||
3252 | if (nodeid == slab_node) { | |
3253 | /* | |
3254 | * Use the locally cached objects if possible. | |
3255 | * However ____cache_alloc does not allow fallback | |
3256 | * to other nodes. It may fail while we still have | |
3257 | * objects on other nodes available. | |
3258 | */ | |
3259 | ptr = ____cache_alloc(cachep, flags); | |
3260 | if (ptr) | |
3261 | goto out; | |
3262 | } | |
3263 | /* ___cache_alloc_node can fall back to other nodes */ | |
3264 | ptr = ____cache_alloc_node(cachep, flags, nodeid); | |
3265 | out: | |
3266 | local_irq_restore(save_flags); | |
3267 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); | |
3268 | kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, | |
3269 | flags); | |
3270 | ||
3271 | if (likely(ptr)) { | |
3272 | kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); | |
3273 | if (unlikely(flags & __GFP_ZERO)) | |
3274 | memset(ptr, 0, cachep->object_size); | |
3275 | } | |
3276 | ||
3277 | return ptr; | |
3278 | } | |
3279 | ||
3280 | static __always_inline void * | |
3281 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) | |
3282 | { | |
3283 | void *objp; | |
3284 | ||
3285 | if (current->mempolicy || unlikely(current->flags & PF_SPREAD_SLAB)) { | |
3286 | objp = alternate_node_alloc(cache, flags); | |
3287 | if (objp) | |
3288 | goto out; | |
3289 | } | |
3290 | objp = ____cache_alloc(cache, flags); | |
3291 | ||
3292 | /* | |
3293 | * We may just have run out of memory on the local node. | |
3294 | * ____cache_alloc_node() knows how to locate memory on other nodes | |
3295 | */ | |
3296 | if (!objp) | |
3297 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); | |
3298 | ||
3299 | out: | |
3300 | return objp; | |
3301 | } | |
3302 | #else | |
3303 | ||
3304 | static __always_inline void * | |
3305 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3306 | { | |
3307 | return ____cache_alloc(cachep, flags); | |
3308 | } | |
3309 | ||
3310 | #endif /* CONFIG_NUMA */ | |
3311 | ||
3312 | static __always_inline void * | |
3313 | slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) | |
3314 | { | |
3315 | unsigned long save_flags; | |
3316 | void *objp; | |
3317 | ||
3318 | flags &= gfp_allowed_mask; | |
3319 | ||
3320 | lockdep_trace_alloc(flags); | |
3321 | ||
3322 | if (slab_should_failslab(cachep, flags)) | |
3323 | return NULL; | |
3324 | ||
3325 | cachep = memcg_kmem_get_cache(cachep, flags); | |
3326 | ||
3327 | cache_alloc_debugcheck_before(cachep, flags); | |
3328 | local_irq_save(save_flags); | |
3329 | objp = __do_cache_alloc(cachep, flags); | |
3330 | local_irq_restore(save_flags); | |
3331 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); | |
3332 | kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, | |
3333 | flags); | |
3334 | prefetchw(objp); | |
3335 | ||
3336 | if (likely(objp)) { | |
3337 | kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); | |
3338 | if (unlikely(flags & __GFP_ZERO)) | |
3339 | memset(objp, 0, cachep->object_size); | |
3340 | } | |
3341 | ||
3342 | return objp; | |
3343 | } | |
3344 | ||
3345 | /* | |
3346 | * Caller needs to acquire correct kmem_cache_node's list_lock | |
3347 | */ | |
3348 | static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, | |
3349 | int node) | |
3350 | { | |
3351 | int i; | |
3352 | struct kmem_cache_node *n; | |
3353 | ||
3354 | for (i = 0; i < nr_objects; i++) { | |
3355 | void *objp; | |
3356 | struct page *page; | |
3357 | ||
3358 | clear_obj_pfmemalloc(&objpp[i]); | |
3359 | objp = objpp[i]; | |
3360 | ||
3361 | page = virt_to_head_page(objp); | |
3362 | n = cachep->node[node]; | |
3363 | list_del(&page->lru); | |
3364 | check_spinlock_acquired_node(cachep, node); | |
3365 | slab_put_obj(cachep, page, objp, node); | |
3366 | STATS_DEC_ACTIVE(cachep); | |
3367 | n->free_objects++; | |
3368 | ||
3369 | /* fixup slab chains */ | |
3370 | if (page->active == 0) { | |
3371 | if (n->free_objects > n->free_limit) { | |
3372 | n->free_objects -= cachep->num; | |
3373 | /* No need to drop any previously held | |
3374 | * lock here, even if we have a off-slab slab | |
3375 | * descriptor it is guaranteed to come from | |
3376 | * a different cache, refer to comments before | |
3377 | * alloc_slabmgmt. | |
3378 | */ | |
3379 | slab_destroy(cachep, page); | |
3380 | } else { | |
3381 | list_add(&page->lru, &n->slabs_free); | |
3382 | } | |
3383 | } else { | |
3384 | /* Unconditionally move a slab to the end of the | |
3385 | * partial list on free - maximum time for the | |
3386 | * other objects to be freed, too. | |
3387 | */ | |
3388 | list_add_tail(&page->lru, &n->slabs_partial); | |
3389 | } | |
3390 | } | |
3391 | } | |
3392 | ||
3393 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) | |
3394 | { | |
3395 | int batchcount; | |
3396 | struct kmem_cache_node *n; | |
3397 | int node = numa_mem_id(); | |
3398 | ||
3399 | batchcount = ac->batchcount; | |
3400 | #if DEBUG | |
3401 | BUG_ON(!batchcount || batchcount > ac->avail); | |
3402 | #endif | |
3403 | check_irq_off(); | |
3404 | n = cachep->node[node]; | |
3405 | spin_lock(&n->list_lock); | |
3406 | if (n->shared) { | |
3407 | struct array_cache *shared_array = n->shared; | |
3408 | int max = shared_array->limit - shared_array->avail; | |
3409 | if (max) { | |
3410 | if (batchcount > max) | |
3411 | batchcount = max; | |
3412 | memcpy(&(shared_array->entry[shared_array->avail]), | |
3413 | ac->entry, sizeof(void *) * batchcount); | |
3414 | shared_array->avail += batchcount; | |
3415 | goto free_done; | |
3416 | } | |
3417 | } | |
3418 | ||
3419 | free_block(cachep, ac->entry, batchcount, node); | |
3420 | free_done: | |
3421 | #if STATS | |
3422 | { | |
3423 | int i = 0; | |
3424 | struct list_head *p; | |
3425 | ||
3426 | p = n->slabs_free.next; | |
3427 | while (p != &(n->slabs_free)) { | |
3428 | struct page *page; | |
3429 | ||
3430 | page = list_entry(p, struct page, lru); | |
3431 | BUG_ON(page->active); | |
3432 | ||
3433 | i++; | |
3434 | p = p->next; | |
3435 | } | |
3436 | STATS_SET_FREEABLE(cachep, i); | |
3437 | } | |
3438 | #endif | |
3439 | spin_unlock(&n->list_lock); | |
3440 | ac->avail -= batchcount; | |
3441 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); | |
3442 | } | |
3443 | ||
3444 | /* | |
3445 | * Release an obj back to its cache. If the obj has a constructed state, it must | |
3446 | * be in this state _before_ it is released. Called with disabled ints. | |
3447 | */ | |
3448 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, | |
3449 | unsigned long caller) | |
3450 | { | |
3451 | struct array_cache *ac = cpu_cache_get(cachep); | |
3452 | ||
3453 | check_irq_off(); | |
3454 | kmemleak_free_recursive(objp, cachep->flags); | |
3455 | objp = cache_free_debugcheck(cachep, objp, caller); | |
3456 | ||
3457 | kmemcheck_slab_free(cachep, objp, cachep->object_size); | |
3458 | ||
3459 | /* | |
3460 | * Skip calling cache_free_alien() when the platform is not numa. | |
3461 | * This will avoid cache misses that happen while accessing slabp (which | |
3462 | * is per page memory reference) to get nodeid. Instead use a global | |
3463 | * variable to skip the call, which is mostly likely to be present in | |
3464 | * the cache. | |
3465 | */ | |
3466 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) | |
3467 | return; | |
3468 | ||
3469 | if (likely(ac->avail < ac->limit)) { | |
3470 | STATS_INC_FREEHIT(cachep); | |
3471 | } else { | |
3472 | STATS_INC_FREEMISS(cachep); | |
3473 | cache_flusharray(cachep, ac); | |
3474 | } | |
3475 | ||
3476 | ac_put_obj(cachep, ac, objp); | |
3477 | } | |
3478 | ||
3479 | /** | |
3480 | * kmem_cache_alloc - Allocate an object | |
3481 | * @cachep: The cache to allocate from. | |
3482 | * @flags: See kmalloc(). | |
3483 | * | |
3484 | * Allocate an object from this cache. The flags are only relevant | |
3485 | * if the cache has no available objects. | |
3486 | */ | |
3487 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3488 | { | |
3489 | void *ret = slab_alloc(cachep, flags, _RET_IP_); | |
3490 | ||
3491 | trace_kmem_cache_alloc(_RET_IP_, ret, | |
3492 | cachep->object_size, cachep->size, flags); | |
3493 | ||
3494 | return ret; | |
3495 | } | |
3496 | EXPORT_SYMBOL(kmem_cache_alloc); | |
3497 | ||
3498 | #ifdef CONFIG_TRACING | |
3499 | void * | |
3500 | kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) | |
3501 | { | |
3502 | void *ret; | |
3503 | ||
3504 | ret = slab_alloc(cachep, flags, _RET_IP_); | |
3505 | ||
3506 | trace_kmalloc(_RET_IP_, ret, | |
3507 | size, cachep->size, flags); | |
3508 | return ret; | |
3509 | } | |
3510 | EXPORT_SYMBOL(kmem_cache_alloc_trace); | |
3511 | #endif | |
3512 | ||
3513 | #ifdef CONFIG_NUMA | |
3514 | /** | |
3515 | * kmem_cache_alloc_node - Allocate an object on the specified node | |
3516 | * @cachep: The cache to allocate from. | |
3517 | * @flags: See kmalloc(). | |
3518 | * @nodeid: node number of the target node. | |
3519 | * | |
3520 | * Identical to kmem_cache_alloc but it will allocate memory on the given | |
3521 | * node, which can improve the performance for cpu bound structures. | |
3522 | * | |
3523 | * Fallback to other node is possible if __GFP_THISNODE is not set. | |
3524 | */ | |
3525 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) | |
3526 | { | |
3527 | void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); | |
3528 | ||
3529 | trace_kmem_cache_alloc_node(_RET_IP_, ret, | |
3530 | cachep->object_size, cachep->size, | |
3531 | flags, nodeid); | |
3532 | ||
3533 | return ret; | |
3534 | } | |
3535 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
3536 | ||
3537 | #ifdef CONFIG_TRACING | |
3538 | void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, | |
3539 | gfp_t flags, | |
3540 | int nodeid, | |
3541 | size_t size) | |
3542 | { | |
3543 | void *ret; | |
3544 | ||
3545 | ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); | |
3546 | ||
3547 | trace_kmalloc_node(_RET_IP_, ret, | |
3548 | size, cachep->size, | |
3549 | flags, nodeid); | |
3550 | return ret; | |
3551 | } | |
3552 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); | |
3553 | #endif | |
3554 | ||
3555 | static __always_inline void * | |
3556 | __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) | |
3557 | { | |
3558 | struct kmem_cache *cachep; | |
3559 | ||
3560 | cachep = kmalloc_slab(size, flags); | |
3561 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) | |
3562 | return cachep; | |
3563 | return kmem_cache_alloc_node_trace(cachep, flags, node, size); | |
3564 | } | |
3565 | ||
3566 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) | |
3567 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
3568 | { | |
3569 | return __do_kmalloc_node(size, flags, node, _RET_IP_); | |
3570 | } | |
3571 | EXPORT_SYMBOL(__kmalloc_node); | |
3572 | ||
3573 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, | |
3574 | int node, unsigned long caller) | |
3575 | { | |
3576 | return __do_kmalloc_node(size, flags, node, caller); | |
3577 | } | |
3578 | EXPORT_SYMBOL(__kmalloc_node_track_caller); | |
3579 | #else | |
3580 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
3581 | { | |
3582 | return __do_kmalloc_node(size, flags, node, 0); | |
3583 | } | |
3584 | EXPORT_SYMBOL(__kmalloc_node); | |
3585 | #endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ | |
3586 | #endif /* CONFIG_NUMA */ | |
3587 | ||
3588 | /** | |
3589 | * __do_kmalloc - allocate memory | |
3590 | * @size: how many bytes of memory are required. | |
3591 | * @flags: the type of memory to allocate (see kmalloc). | |
3592 | * @caller: function caller for debug tracking of the caller | |
3593 | */ | |
3594 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, | |
3595 | unsigned long caller) | |
3596 | { | |
3597 | struct kmem_cache *cachep; | |
3598 | void *ret; | |
3599 | ||
3600 | cachep = kmalloc_slab(size, flags); | |
3601 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) | |
3602 | return cachep; | |
3603 | ret = slab_alloc(cachep, flags, caller); | |
3604 | ||
3605 | trace_kmalloc(caller, ret, | |
3606 | size, cachep->size, flags); | |
3607 | ||
3608 | return ret; | |
3609 | } | |
3610 | ||
3611 | ||
3612 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) | |
3613 | void *__kmalloc(size_t size, gfp_t flags) | |
3614 | { | |
3615 | return __do_kmalloc(size, flags, _RET_IP_); | |
3616 | } | |
3617 | EXPORT_SYMBOL(__kmalloc); | |
3618 | ||
3619 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) | |
3620 | { | |
3621 | return __do_kmalloc(size, flags, caller); | |
3622 | } | |
3623 | EXPORT_SYMBOL(__kmalloc_track_caller); | |
3624 | ||
3625 | #else | |
3626 | void *__kmalloc(size_t size, gfp_t flags) | |
3627 | { | |
3628 | return __do_kmalloc(size, flags, 0); | |
3629 | } | |
3630 | EXPORT_SYMBOL(__kmalloc); | |
3631 | #endif | |
3632 | ||
3633 | /** | |
3634 | * kmem_cache_free - Deallocate an object | |
3635 | * @cachep: The cache the allocation was from. | |
3636 | * @objp: The previously allocated object. | |
3637 | * | |
3638 | * Free an object which was previously allocated from this | |
3639 | * cache. | |
3640 | */ | |
3641 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) | |
3642 | { | |
3643 | unsigned long flags; | |
3644 | cachep = cache_from_obj(cachep, objp); | |
3645 | if (!cachep) | |
3646 | return; | |
3647 | ||
3648 | local_irq_save(flags); | |
3649 | debug_check_no_locks_freed(objp, cachep->object_size); | |
3650 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) | |
3651 | debug_check_no_obj_freed(objp, cachep->object_size); | |
3652 | __cache_free(cachep, objp, _RET_IP_); | |
3653 | local_irq_restore(flags); | |
3654 | ||
3655 | trace_kmem_cache_free(_RET_IP_, objp); | |
3656 | } | |
3657 | EXPORT_SYMBOL(kmem_cache_free); | |
3658 | ||
3659 | /** | |
3660 | * kfree - free previously allocated memory | |
3661 | * @objp: pointer returned by kmalloc. | |
3662 | * | |
3663 | * If @objp is NULL, no operation is performed. | |
3664 | * | |
3665 | * Don't free memory not originally allocated by kmalloc() | |
3666 | * or you will run into trouble. | |
3667 | */ | |
3668 | void kfree(const void *objp) | |
3669 | { | |
3670 | struct kmem_cache *c; | |
3671 | unsigned long flags; | |
3672 | ||
3673 | trace_kfree(_RET_IP_, objp); | |
3674 | ||
3675 | if (unlikely(ZERO_OR_NULL_PTR(objp))) | |
3676 | return; | |
3677 | local_irq_save(flags); | |
3678 | kfree_debugcheck(objp); | |
3679 | c = virt_to_cache(objp); | |
3680 | debug_check_no_locks_freed(objp, c->object_size); | |
3681 | ||
3682 | debug_check_no_obj_freed(objp, c->object_size); | |
3683 | __cache_free(c, (void *)objp, _RET_IP_); | |
3684 | local_irq_restore(flags); | |
3685 | } | |
3686 | EXPORT_SYMBOL(kfree); | |
3687 | ||
3688 | /* | |
3689 | * This initializes kmem_cache_node or resizes various caches for all nodes. | |
3690 | */ | |
3691 | static int alloc_kmem_cache_node(struct kmem_cache *cachep, gfp_t gfp) | |
3692 | { | |
3693 | int node; | |
3694 | struct kmem_cache_node *n; | |
3695 | struct array_cache *new_shared; | |
3696 | struct array_cache **new_alien = NULL; | |
3697 | ||
3698 | for_each_online_node(node) { | |
3699 | ||
3700 | if (use_alien_caches) { | |
3701 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); | |
3702 | if (!new_alien) | |
3703 | goto fail; | |
3704 | } | |
3705 | ||
3706 | new_shared = NULL; | |
3707 | if (cachep->shared) { | |
3708 | new_shared = alloc_arraycache(node, | |
3709 | cachep->shared*cachep->batchcount, | |
3710 | 0xbaadf00d, gfp); | |
3711 | if (!new_shared) { | |
3712 | free_alien_cache(new_alien); | |
3713 | goto fail; | |
3714 | } | |
3715 | } | |
3716 | ||
3717 | n = cachep->node[node]; | |
3718 | if (n) { | |
3719 | struct array_cache *shared = n->shared; | |
3720 | ||
3721 | spin_lock_irq(&n->list_lock); | |
3722 | ||
3723 | if (shared) | |
3724 | free_block(cachep, shared->entry, | |
3725 | shared->avail, node); | |
3726 | ||
3727 | n->shared = new_shared; | |
3728 | if (!n->alien) { | |
3729 | n->alien = new_alien; | |
3730 | new_alien = NULL; | |
3731 | } | |
3732 | n->free_limit = (1 + nr_cpus_node(node)) * | |
3733 | cachep->batchcount + cachep->num; | |
3734 | spin_unlock_irq(&n->list_lock); | |
3735 | kfree(shared); | |
3736 | free_alien_cache(new_alien); | |
3737 | continue; | |
3738 | } | |
3739 | n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); | |
3740 | if (!n) { | |
3741 | free_alien_cache(new_alien); | |
3742 | kfree(new_shared); | |
3743 | goto fail; | |
3744 | } | |
3745 | ||
3746 | kmem_cache_node_init(n); | |
3747 | n->next_reap = jiffies + REAPTIMEOUT_NODE + | |
3748 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; | |
3749 | n->shared = new_shared; | |
3750 | n->alien = new_alien; | |
3751 | n->free_limit = (1 + nr_cpus_node(node)) * | |
3752 | cachep->batchcount + cachep->num; | |
3753 | cachep->node[node] = n; | |
3754 | } | |
3755 | return 0; | |
3756 | ||
3757 | fail: | |
3758 | if (!cachep->list.next) { | |
3759 | /* Cache is not active yet. Roll back what we did */ | |
3760 | node--; | |
3761 | while (node >= 0) { | |
3762 | if (cachep->node[node]) { | |
3763 | n = cachep->node[node]; | |
3764 | ||
3765 | kfree(n->shared); | |
3766 | free_alien_cache(n->alien); | |
3767 | kfree(n); | |
3768 | cachep->node[node] = NULL; | |
3769 | } | |
3770 | node--; | |
3771 | } | |
3772 | } | |
3773 | return -ENOMEM; | |
3774 | } | |
3775 | ||
3776 | struct ccupdate_struct { | |
3777 | struct kmem_cache *cachep; | |
3778 | struct array_cache *new[0]; | |
3779 | }; | |
3780 | ||
3781 | static void do_ccupdate_local(void *info) | |
3782 | { | |
3783 | struct ccupdate_struct *new = info; | |
3784 | struct array_cache *old; | |
3785 | ||
3786 | check_irq_off(); | |
3787 | old = cpu_cache_get(new->cachep); | |
3788 | ||
3789 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; | |
3790 | new->new[smp_processor_id()] = old; | |
3791 | } | |
3792 | ||
3793 | /* Always called with the slab_mutex held */ | |
3794 | static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, | |
3795 | int batchcount, int shared, gfp_t gfp) | |
3796 | { | |
3797 | struct ccupdate_struct *new; | |
3798 | int i; | |
3799 | ||
3800 | new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *), | |
3801 | gfp); | |
3802 | if (!new) | |
3803 | return -ENOMEM; | |
3804 | ||
3805 | for_each_online_cpu(i) { | |
3806 | new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, | |
3807 | batchcount, gfp); | |
3808 | if (!new->new[i]) { | |
3809 | for (i--; i >= 0; i--) | |
3810 | kfree(new->new[i]); | |
3811 | kfree(new); | |
3812 | return -ENOMEM; | |
3813 | } | |
3814 | } | |
3815 | new->cachep = cachep; | |
3816 | ||
3817 | on_each_cpu(do_ccupdate_local, (void *)new, 1); | |
3818 | ||
3819 | check_irq_on(); | |
3820 | cachep->batchcount = batchcount; | |
3821 | cachep->limit = limit; | |
3822 | cachep->shared = shared; | |
3823 | ||
3824 | for_each_online_cpu(i) { | |
3825 | struct array_cache *ccold = new->new[i]; | |
3826 | if (!ccold) | |
3827 | continue; | |
3828 | spin_lock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); | |
3829 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); | |
3830 | spin_unlock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); | |
3831 | kfree(ccold); | |
3832 | } | |
3833 | kfree(new); | |
3834 | return alloc_kmem_cache_node(cachep, gfp); | |
3835 | } | |
3836 | ||
3837 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, | |
3838 | int batchcount, int shared, gfp_t gfp) | |
3839 | { | |
3840 | int ret; | |
3841 | struct kmem_cache *c = NULL; | |
3842 | int i = 0; | |
3843 | ||
3844 | ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); | |
3845 | ||
3846 | if (slab_state < FULL) | |
3847 | return ret; | |
3848 | ||
3849 | if ((ret < 0) || !is_root_cache(cachep)) | |
3850 | return ret; | |
3851 | ||
3852 | VM_BUG_ON(!mutex_is_locked(&slab_mutex)); | |
3853 | for_each_memcg_cache_index(i) { | |
3854 | c = cache_from_memcg_idx(cachep, i); | |
3855 | if (c) | |
3856 | /* return value determined by the parent cache only */ | |
3857 | __do_tune_cpucache(c, limit, batchcount, shared, gfp); | |
3858 | } | |
3859 | ||
3860 | return ret; | |
3861 | } | |
3862 | ||
3863 | /* Called with slab_mutex held always */ | |
3864 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) | |
3865 | { | |
3866 | int err; | |
3867 | int limit = 0; | |
3868 | int shared = 0; | |
3869 | int batchcount = 0; | |
3870 | ||
3871 | if (!is_root_cache(cachep)) { | |
3872 | struct kmem_cache *root = memcg_root_cache(cachep); | |
3873 | limit = root->limit; | |
3874 | shared = root->shared; | |
3875 | batchcount = root->batchcount; | |
3876 | } | |
3877 | ||
3878 | if (limit && shared && batchcount) | |
3879 | goto skip_setup; | |
3880 | /* | |
3881 | * The head array serves three purposes: | |
3882 | * - create a LIFO ordering, i.e. return objects that are cache-warm | |
3883 | * - reduce the number of spinlock operations. | |
3884 | * - reduce the number of linked list operations on the slab and | |
3885 | * bufctl chains: array operations are cheaper. | |
3886 | * The numbers are guessed, we should auto-tune as described by | |
3887 | * Bonwick. | |
3888 | */ | |
3889 | if (cachep->size > 131072) | |
3890 | limit = 1; | |
3891 | else if (cachep->size > PAGE_SIZE) | |
3892 | limit = 8; | |
3893 | else if (cachep->size > 1024) | |
3894 | limit = 24; | |
3895 | else if (cachep->size > 256) | |
3896 | limit = 54; | |
3897 | else | |
3898 | limit = 120; | |
3899 | ||
3900 | /* | |
3901 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound | |
3902 | * allocation behaviour: Most allocs on one cpu, most free operations | |
3903 | * on another cpu. For these cases, an efficient object passing between | |
3904 | * cpus is necessary. This is provided by a shared array. The array | |
3905 | * replaces Bonwick's magazine layer. | |
3906 | * On uniprocessor, it's functionally equivalent (but less efficient) | |
3907 | * to a larger limit. Thus disabled by default. | |
3908 | */ | |
3909 | shared = 0; | |
3910 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) | |
3911 | shared = 8; | |
3912 | ||
3913 | #if DEBUG | |
3914 | /* | |
3915 | * With debugging enabled, large batchcount lead to excessively long | |
3916 | * periods with disabled local interrupts. Limit the batchcount | |
3917 | */ | |
3918 | if (limit > 32) | |
3919 | limit = 32; | |
3920 | #endif | |
3921 | batchcount = (limit + 1) / 2; | |
3922 | skip_setup: | |
3923 | err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); | |
3924 | if (err) | |
3925 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", | |
3926 | cachep->name, -err); | |
3927 | return err; | |
3928 | } | |
3929 | ||
3930 | /* | |
3931 | * Drain an array if it contains any elements taking the node lock only if | |
3932 | * necessary. Note that the node listlock also protects the array_cache | |
3933 | * if drain_array() is used on the shared array. | |
3934 | */ | |
3935 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, | |
3936 | struct array_cache *ac, int force, int node) | |
3937 | { | |
3938 | int tofree; | |
3939 | ||
3940 | if (!ac || !ac->avail) | |
3941 | return; | |
3942 | if (ac->touched && !force) { | |
3943 | ac->touched = 0; | |
3944 | } else { | |
3945 | spin_lock_irq(&n->list_lock); | |
3946 | if (ac->avail) { | |
3947 | tofree = force ? ac->avail : (ac->limit + 4) / 5; | |
3948 | if (tofree > ac->avail) | |
3949 | tofree = (ac->avail + 1) / 2; | |
3950 | free_block(cachep, ac->entry, tofree, node); | |
3951 | ac->avail -= tofree; | |
3952 | memmove(ac->entry, &(ac->entry[tofree]), | |
3953 | sizeof(void *) * ac->avail); | |
3954 | } | |
3955 | spin_unlock_irq(&n->list_lock); | |
3956 | } | |
3957 | } | |
3958 | ||
3959 | /** | |
3960 | * cache_reap - Reclaim memory from caches. | |
3961 | * @w: work descriptor | |
3962 | * | |
3963 | * Called from workqueue/eventd every few seconds. | |
3964 | * Purpose: | |
3965 | * - clear the per-cpu caches for this CPU. | |
3966 | * - return freeable pages to the main free memory pool. | |
3967 | * | |
3968 | * If we cannot acquire the cache chain mutex then just give up - we'll try | |
3969 | * again on the next iteration. | |
3970 | */ | |
3971 | static void cache_reap(struct work_struct *w) | |
3972 | { | |
3973 | struct kmem_cache *searchp; | |
3974 | struct kmem_cache_node *n; | |
3975 | int node = numa_mem_id(); | |
3976 | struct delayed_work *work = to_delayed_work(w); | |
3977 | ||
3978 | if (!mutex_trylock(&slab_mutex)) | |
3979 | /* Give up. Setup the next iteration. */ | |
3980 | goto out; | |
3981 | ||
3982 | list_for_each_entry(searchp, &slab_caches, list) { | |
3983 | check_irq_on(); | |
3984 | ||
3985 | /* | |
3986 | * We only take the node lock if absolutely necessary and we | |
3987 | * have established with reasonable certainty that | |
3988 | * we can do some work if the lock was obtained. | |
3989 | */ | |
3990 | n = searchp->node[node]; | |
3991 | ||
3992 | reap_alien(searchp, n); | |
3993 | ||
3994 | drain_array(searchp, n, cpu_cache_get(searchp), 0, node); | |
3995 | ||
3996 | /* | |
3997 | * These are racy checks but it does not matter | |
3998 | * if we skip one check or scan twice. | |
3999 | */ | |
4000 | if (time_after(n->next_reap, jiffies)) | |
4001 | goto next; | |
4002 | ||
4003 | n->next_reap = jiffies + REAPTIMEOUT_NODE; | |
4004 | ||
4005 | drain_array(searchp, n, n->shared, 0, node); | |
4006 | ||
4007 | if (n->free_touched) | |
4008 | n->free_touched = 0; | |
4009 | else { | |
4010 | int freed; | |
4011 | ||
4012 | freed = drain_freelist(searchp, n, (n->free_limit + | |
4013 | 5 * searchp->num - 1) / (5 * searchp->num)); | |
4014 | STATS_ADD_REAPED(searchp, freed); | |
4015 | } | |
4016 | next: | |
4017 | cond_resched(); | |
4018 | } | |
4019 | check_irq_on(); | |
4020 | mutex_unlock(&slab_mutex); | |
4021 | next_reap_node(); | |
4022 | out: | |
4023 | /* Set up the next iteration */ | |
4024 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC)); | |
4025 | } | |
4026 | ||
4027 | #ifdef CONFIG_SLABINFO | |
4028 | void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) | |
4029 | { | |
4030 | struct page *page; | |
4031 | unsigned long active_objs; | |
4032 | unsigned long num_objs; | |
4033 | unsigned long active_slabs = 0; | |
4034 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; | |
4035 | const char *name; | |
4036 | char *error = NULL; | |
4037 | int node; | |
4038 | struct kmem_cache_node *n; | |
4039 | ||
4040 | active_objs = 0; | |
4041 | num_slabs = 0; | |
4042 | for_each_online_node(node) { | |
4043 | n = cachep->node[node]; | |
4044 | if (!n) | |
4045 | continue; | |
4046 | ||
4047 | check_irq_on(); | |
4048 | spin_lock_irq(&n->list_lock); | |
4049 | ||
4050 | list_for_each_entry(page, &n->slabs_full, lru) { | |
4051 | if (page->active != cachep->num && !error) | |
4052 | error = "slabs_full accounting error"; | |
4053 | active_objs += cachep->num; | |
4054 | active_slabs++; | |
4055 | } | |
4056 | list_for_each_entry(page, &n->slabs_partial, lru) { | |
4057 | if (page->active == cachep->num && !error) | |
4058 | error = "slabs_partial accounting error"; | |
4059 | if (!page->active && !error) | |
4060 | error = "slabs_partial accounting error"; | |
4061 | active_objs += page->active; | |
4062 | active_slabs++; | |
4063 | } | |
4064 | list_for_each_entry(page, &n->slabs_free, lru) { | |
4065 | if (page->active && !error) | |
4066 | error = "slabs_free accounting error"; | |
4067 | num_slabs++; | |
4068 | } | |
4069 | free_objects += n->free_objects; | |
4070 | if (n->shared) | |
4071 | shared_avail += n->shared->avail; | |
4072 | ||
4073 | spin_unlock_irq(&n->list_lock); | |
4074 | } | |
4075 | num_slabs += active_slabs; | |
4076 | num_objs = num_slabs * cachep->num; | |
4077 | if (num_objs - active_objs != free_objects && !error) | |
4078 | error = "free_objects accounting error"; | |
4079 | ||
4080 | name = cachep->name; | |
4081 | if (error) | |
4082 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); | |
4083 | ||
4084 | sinfo->active_objs = active_objs; | |
4085 | sinfo->num_objs = num_objs; | |
4086 | sinfo->active_slabs = active_slabs; | |
4087 | sinfo->num_slabs = num_slabs; | |
4088 | sinfo->shared_avail = shared_avail; | |
4089 | sinfo->limit = cachep->limit; | |
4090 | sinfo->batchcount = cachep->batchcount; | |
4091 | sinfo->shared = cachep->shared; | |
4092 | sinfo->objects_per_slab = cachep->num; | |
4093 | sinfo->cache_order = cachep->gfporder; | |
4094 | } | |
4095 | ||
4096 | void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) | |
4097 | { | |
4098 | #if STATS | |
4099 | { /* node stats */ | |
4100 | unsigned long high = cachep->high_mark; | |
4101 | unsigned long allocs = cachep->num_allocations; | |
4102 | unsigned long grown = cachep->grown; | |
4103 | unsigned long reaped = cachep->reaped; | |
4104 | unsigned long errors = cachep->errors; | |
4105 | unsigned long max_freeable = cachep->max_freeable; | |
4106 | unsigned long node_allocs = cachep->node_allocs; | |
4107 | unsigned long node_frees = cachep->node_frees; | |
4108 | unsigned long overflows = cachep->node_overflow; | |
4109 | ||
4110 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " | |
4111 | "%4lu %4lu %4lu %4lu %4lu", | |
4112 | allocs, high, grown, | |
4113 | reaped, errors, max_freeable, node_allocs, | |
4114 | node_frees, overflows); | |
4115 | } | |
4116 | /* cpu stats */ | |
4117 | { | |
4118 | unsigned long allochit = atomic_read(&cachep->allochit); | |
4119 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); | |
4120 | unsigned long freehit = atomic_read(&cachep->freehit); | |
4121 | unsigned long freemiss = atomic_read(&cachep->freemiss); | |
4122 | ||
4123 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", | |
4124 | allochit, allocmiss, freehit, freemiss); | |
4125 | } | |
4126 | #endif | |
4127 | } | |
4128 | ||
4129 | #define MAX_SLABINFO_WRITE 128 | |
4130 | /** | |
4131 | * slabinfo_write - Tuning for the slab allocator | |
4132 | * @file: unused | |
4133 | * @buffer: user buffer | |
4134 | * @count: data length | |
4135 | * @ppos: unused | |
4136 | */ | |
4137 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, | |
4138 | size_t count, loff_t *ppos) | |
4139 | { | |
4140 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; | |
4141 | int limit, batchcount, shared, res; | |
4142 | struct kmem_cache *cachep; | |
4143 | ||
4144 | if (count > MAX_SLABINFO_WRITE) | |
4145 | return -EINVAL; | |
4146 | if (copy_from_user(&kbuf, buffer, count)) | |
4147 | return -EFAULT; | |
4148 | kbuf[MAX_SLABINFO_WRITE] = '\0'; | |
4149 | ||
4150 | tmp = strchr(kbuf, ' '); | |
4151 | if (!tmp) | |
4152 | return -EINVAL; | |
4153 | *tmp = '\0'; | |
4154 | tmp++; | |
4155 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) | |
4156 | return -EINVAL; | |
4157 | ||
4158 | /* Find the cache in the chain of caches. */ | |
4159 | mutex_lock(&slab_mutex); | |
4160 | res = -EINVAL; | |
4161 | list_for_each_entry(cachep, &slab_caches, list) { | |
4162 | if (!strcmp(cachep->name, kbuf)) { | |
4163 | if (limit < 1 || batchcount < 1 || | |
4164 | batchcount > limit || shared < 0) { | |
4165 | res = 0; | |
4166 | } else { | |
4167 | res = do_tune_cpucache(cachep, limit, | |
4168 | batchcount, shared, | |
4169 | GFP_KERNEL); | |
4170 | } | |
4171 | break; | |
4172 | } | |
4173 | } | |
4174 | mutex_unlock(&slab_mutex); | |
4175 | if (res >= 0) | |
4176 | res = count; | |
4177 | return res; | |
4178 | } | |
4179 | ||
4180 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
4181 | ||
4182 | static void *leaks_start(struct seq_file *m, loff_t *pos) | |
4183 | { | |
4184 | mutex_lock(&slab_mutex); | |
4185 | return seq_list_start(&slab_caches, *pos); | |
4186 | } | |
4187 | ||
4188 | static inline int add_caller(unsigned long *n, unsigned long v) | |
4189 | { | |
4190 | unsigned long *p; | |
4191 | int l; | |
4192 | if (!v) | |
4193 | return 1; | |
4194 | l = n[1]; | |
4195 | p = n + 2; | |
4196 | while (l) { | |
4197 | int i = l/2; | |
4198 | unsigned long *q = p + 2 * i; | |
4199 | if (*q == v) { | |
4200 | q[1]++; | |
4201 | return 1; | |
4202 | } | |
4203 | if (*q > v) { | |
4204 | l = i; | |
4205 | } else { | |
4206 | p = q + 2; | |
4207 | l -= i + 1; | |
4208 | } | |
4209 | } | |
4210 | if (++n[1] == n[0]) | |
4211 | return 0; | |
4212 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); | |
4213 | p[0] = v; | |
4214 | p[1] = 1; | |
4215 | return 1; | |
4216 | } | |
4217 | ||
4218 | static void handle_slab(unsigned long *n, struct kmem_cache *c, | |
4219 | struct page *page) | |
4220 | { | |
4221 | void *p; | |
4222 | int i, j; | |
4223 | ||
4224 | if (n[0] == n[1]) | |
4225 | return; | |
4226 | for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) { | |
4227 | bool active = true; | |
4228 | ||
4229 | for (j = page->active; j < c->num; j++) { | |
4230 | /* Skip freed item */ | |
4231 | if (get_free_obj(page, j) == i) { | |
4232 | active = false; | |
4233 | break; | |
4234 | } | |
4235 | } | |
4236 | if (!active) | |
4237 | continue; | |
4238 | ||
4239 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) | |
4240 | return; | |
4241 | } | |
4242 | } | |
4243 | ||
4244 | static void show_symbol(struct seq_file *m, unsigned long address) | |
4245 | { | |
4246 | #ifdef CONFIG_KALLSYMS | |
4247 | unsigned long offset, size; | |
4248 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; | |
4249 | ||
4250 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { | |
4251 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); | |
4252 | if (modname[0]) | |
4253 | seq_printf(m, " [%s]", modname); | |
4254 | return; | |
4255 | } | |
4256 | #endif | |
4257 | seq_printf(m, "%p", (void *)address); | |
4258 | } | |
4259 | ||
4260 | static int leaks_show(struct seq_file *m, void *p) | |
4261 | { | |
4262 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); | |
4263 | struct page *page; | |
4264 | struct kmem_cache_node *n; | |
4265 | const char *name; | |
4266 | unsigned long *x = m->private; | |
4267 | int node; | |
4268 | int i; | |
4269 | ||
4270 | if (!(cachep->flags & SLAB_STORE_USER)) | |
4271 | return 0; | |
4272 | if (!(cachep->flags & SLAB_RED_ZONE)) | |
4273 | return 0; | |
4274 | ||
4275 | /* OK, we can do it */ | |
4276 | ||
4277 | x[1] = 0; | |
4278 | ||
4279 | for_each_online_node(node) { | |
4280 | n = cachep->node[node]; | |
4281 | if (!n) | |
4282 | continue; | |
4283 | ||
4284 | check_irq_on(); | |
4285 | spin_lock_irq(&n->list_lock); | |
4286 | ||
4287 | list_for_each_entry(page, &n->slabs_full, lru) | |
4288 | handle_slab(x, cachep, page); | |
4289 | list_for_each_entry(page, &n->slabs_partial, lru) | |
4290 | handle_slab(x, cachep, page); | |
4291 | spin_unlock_irq(&n->list_lock); | |
4292 | } | |
4293 | name = cachep->name; | |
4294 | if (x[0] == x[1]) { | |
4295 | /* Increase the buffer size */ | |
4296 | mutex_unlock(&slab_mutex); | |
4297 | m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL); | |
4298 | if (!m->private) { | |
4299 | /* Too bad, we are really out */ | |
4300 | m->private = x; | |
4301 | mutex_lock(&slab_mutex); | |
4302 | return -ENOMEM; | |
4303 | } | |
4304 | *(unsigned long *)m->private = x[0] * 2; | |
4305 | kfree(x); | |
4306 | mutex_lock(&slab_mutex); | |
4307 | /* Now make sure this entry will be retried */ | |
4308 | m->count = m->size; | |
4309 | return 0; | |
4310 | } | |
4311 | for (i = 0; i < x[1]; i++) { | |
4312 | seq_printf(m, "%s: %lu ", name, x[2*i+3]); | |
4313 | show_symbol(m, x[2*i+2]); | |
4314 | seq_putc(m, '\n'); | |
4315 | } | |
4316 | ||
4317 | return 0; | |
4318 | } | |
4319 | ||
4320 | static const struct seq_operations slabstats_op = { | |
4321 | .start = leaks_start, | |
4322 | .next = slab_next, | |
4323 | .stop = slab_stop, | |
4324 | .show = leaks_show, | |
4325 | }; | |
4326 | ||
4327 | static int slabstats_open(struct inode *inode, struct file *file) | |
4328 | { | |
4329 | unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); | |
4330 | int ret = -ENOMEM; | |
4331 | if (n) { | |
4332 | ret = seq_open(file, &slabstats_op); | |
4333 | if (!ret) { | |
4334 | struct seq_file *m = file->private_data; | |
4335 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); | |
4336 | m->private = n; | |
4337 | n = NULL; | |
4338 | } | |
4339 | kfree(n); | |
4340 | } | |
4341 | return ret; | |
4342 | } | |
4343 | ||
4344 | static const struct file_operations proc_slabstats_operations = { | |
4345 | .open = slabstats_open, | |
4346 | .read = seq_read, | |
4347 | .llseek = seq_lseek, | |
4348 | .release = seq_release_private, | |
4349 | }; | |
4350 | #endif | |
4351 | ||
4352 | static int __init slab_proc_init(void) | |
4353 | { | |
4354 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
4355 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); | |
4356 | #endif | |
4357 | return 0; | |
4358 | } | |
4359 | module_init(slab_proc_init); | |
4360 | #endif | |
4361 | ||
4362 | /** | |
4363 | * ksize - get the actual amount of memory allocated for a given object | |
4364 | * @objp: Pointer to the object | |
4365 | * | |
4366 | * kmalloc may internally round up allocations and return more memory | |
4367 | * than requested. ksize() can be used to determine the actual amount of | |
4368 | * memory allocated. The caller may use this additional memory, even though | |
4369 | * a smaller amount of memory was initially specified with the kmalloc call. | |
4370 | * The caller must guarantee that objp points to a valid object previously | |
4371 | * allocated with either kmalloc() or kmem_cache_alloc(). The object | |
4372 | * must not be freed during the duration of the call. | |
4373 | */ | |
4374 | size_t ksize(const void *objp) | |
4375 | { | |
4376 | BUG_ON(!objp); | |
4377 | if (unlikely(objp == ZERO_SIZE_PTR)) | |
4378 | return 0; | |
4379 | ||
4380 | return virt_to_cache(objp)->object_size; | |
4381 | } | |
4382 | EXPORT_SYMBOL(ksize); |