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1 | /* |
2 | * linux/mm/slab.c |
3 | * Written by Mark Hemment, 1996/97. |
4 | * (markhe@nextd.demon.co.uk) |
5 | * |
6 | * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli |
7 | * |
8 | * Major cleanup, different bufctl logic, per-cpu arrays |
9 | * (c) 2000 Manfred Spraul |
10 | * |
11 | * Cleanup, make the head arrays unconditional, preparation for NUMA |
12 | * (c) 2002 Manfred Spraul |
13 | * |
14 | * An implementation of the Slab Allocator as described in outline in; |
15 | * UNIX Internals: The New Frontiers by Uresh Vahalia |
16 | * Pub: Prentice Hall ISBN 0-13-101908-2 |
17 | * or with a little more detail in; |
18 | * The Slab Allocator: An Object-Caching Kernel Memory Allocator |
19 | * Jeff Bonwick (Sun Microsystems). |
20 | * Presented at: USENIX Summer 1994 Technical Conference |
21 | * |
22 | * The memory is organized in caches, one cache for each object type. |
23 | * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) |
24 | * Each cache consists out of many slabs (they are small (usually one |
25 | * page long) and always contiguous), and each slab contains multiple |
26 | * initialized objects. |
27 | * |
28 | * This means, that your constructor is used only for newly allocated |
29 | * slabs and you must pass objects with the same initializations to |
30 | * kmem_cache_free. |
31 | * |
32 | * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM, |
33 | * normal). If you need a special memory type, then must create a new |
34 | * cache for that memory type. |
35 | * |
36 | * In order to reduce fragmentation, the slabs are sorted in 3 groups: |
37 | * full slabs with 0 free objects |
38 | * partial slabs |
39 | * empty slabs with no allocated objects |
40 | * |
41 | * If partial slabs exist, then new allocations come from these slabs, |
42 | * otherwise from empty slabs or new slabs are allocated. |
43 | * |
44 | * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache |
45 | * during kmem_cache_destroy(). The caller must prevent concurrent allocs. |
46 | * |
47 | * Each cache has a short per-cpu head array, most allocs |
48 | * and frees go into that array, and if that array overflows, then 1/2 |
49 | * of the entries in the array are given back into the global cache. |
50 | * The head array is strictly LIFO and should improve the cache hit rates. |
51 | * On SMP, it additionally reduces the spinlock operations. |
52 | * |
53 | * The c_cpuarray may not be read with enabled local interrupts - |
54 | * it's changed with a smp_call_function(). |
55 | * |
56 | * SMP synchronization: |
57 | * constructors and destructors are called without any locking. |
58 | * Several members in struct kmem_cache and struct slab never change, they |
59 | * are accessed without any locking. |
60 | * The per-cpu arrays are never accessed from the wrong cpu, no locking, |
61 | * and local interrupts are disabled so slab code is preempt-safe. |
62 | * The non-constant members are protected with a per-cache irq spinlock. |
63 | * |
64 | * Many thanks to Mark Hemment, who wrote another per-cpu slab patch |
65 | * in 2000 - many ideas in the current implementation are derived from |
66 | * his patch. |
67 | * |
68 | * Further notes from the original documentation: |
69 | * |
70 | * 11 April '97. Started multi-threading - markhe |
71 | * The global cache-chain is protected by the mutex 'slab_mutex'. |
72 | * The sem is only needed when accessing/extending the cache-chain, which |
73 | * can never happen inside an interrupt (kmem_cache_create(), |
74 | * kmem_cache_shrink() and kmem_cache_reap()). |
75 | * |
76 | * At present, each engine can be growing a cache. This should be blocked. |
77 | * |
78 | * 15 March 2005. NUMA slab allocator. |
79 | * Shai Fultheim <shai@scalex86.org>. |
80 | * Shobhit Dayal <shobhit@calsoftinc.com> |
81 | * Alok N Kataria <alokk@calsoftinc.com> |
82 | * Christoph Lameter <christoph@lameter.com> |
83 | * |
84 | * Modified the slab allocator to be node aware on NUMA systems. |
85 | * Each node has its own list of partial, free and full slabs. |
86 | * All object allocations for a node occur from node specific slab lists. |
87 | */ |
88 | |
89 | #include <linux/slab.h> |
90 | #include <linux/mm.h> |
91 | #include <linux/poison.h> |
92 | #include <linux/swap.h> |
93 | #include <linux/cache.h> |
94 | #include <linux/interrupt.h> |
95 | #include <linux/init.h> |
96 | #include <linux/compiler.h> |
97 | #include <linux/cpuset.h> |
98 | #include <linux/proc_fs.h> |
99 | #include <linux/seq_file.h> |
100 | #include <linux/notifier.h> |
101 | #include <linux/kallsyms.h> |
102 | #include <linux/cpu.h> |
103 | #include <linux/sysctl.h> |
104 | #include <linux/module.h> |
105 | #include <linux/rcupdate.h> |
106 | #include <linux/string.h> |
107 | #include <linux/uaccess.h> |
108 | #include <linux/nodemask.h> |
109 | #include <linux/kmemleak.h> |
110 | #include <linux/mempolicy.h> |
111 | #include <linux/mutex.h> |
112 | #include <linux/fault-inject.h> |
113 | #include <linux/rtmutex.h> |
114 | #include <linux/reciprocal_div.h> |
115 | #include <linux/debugobjects.h> |
116 | #include <linux/kmemcheck.h> |
117 | #include <linux/memory.h> |
118 | #include <linux/prefetch.h> |
119 | |
120 | #include <net/sock.h> |
121 | |
122 | #include <asm/cacheflush.h> |
123 | #include <asm/tlbflush.h> |
124 | #include <asm/page.h> |
125 | |
126 | #include <trace/events/kmem.h> |
127 | |
128 | #include "internal.h" |
129 | |
130 | #include "slab.h" |
131 | |
132 | /* |
133 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. |
134 | * 0 for faster, smaller code (especially in the critical paths). |
135 | * |
136 | * STATS - 1 to collect stats for /proc/slabinfo. |
137 | * 0 for faster, smaller code (especially in the critical paths). |
138 | * |
139 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) |
140 | */ |
141 | |
142 | #ifdef CONFIG_DEBUG_SLAB |
143 | #define DEBUG 1 |
144 | #define STATS 1 |
145 | #define FORCED_DEBUG 1 |
146 | #else |
147 | #define DEBUG 0 |
148 | #define STATS 0 |
149 | #define FORCED_DEBUG 0 |
150 | #endif |
151 | |
152 | /* Shouldn't this be in a header file somewhere? */ |
153 | #define BYTES_PER_WORD sizeof(void *) |
154 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) |
155 | |
156 | #ifndef ARCH_KMALLOC_FLAGS |
157 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN |
158 | #endif |
159 | |
160 | /* |
161 | * true if a page was allocated from pfmemalloc reserves for network-based |
162 | * swap |
163 | */ |
164 | static bool pfmemalloc_active __read_mostly; |
165 | |
166 | /* |
167 | * kmem_bufctl_t: |
168 | * |
169 | * Bufctl's are used for linking objs within a slab |
170 | * linked offsets. |
171 | * |
172 | * This implementation relies on "struct page" for locating the cache & |
173 | * slab an object belongs to. |
174 | * This allows the bufctl structure to be small (one int), but limits |
175 | * the number of objects a slab (not a cache) can contain when off-slab |
176 | * bufctls are used. The limit is the size of the largest general cache |
177 | * that does not use off-slab slabs. |
178 | * For 32bit archs with 4 kB pages, is this 56. |
179 | * This is not serious, as it is only for large objects, when it is unwise |
180 | * to have too many per slab. |
181 | * Note: This limit can be raised by introducing a general cache whose size |
182 | * is less than 512 (PAGE_SIZE<<3), but greater than 256. |
183 | */ |
184 | |
185 | typedef unsigned int kmem_bufctl_t; |
186 | #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) |
187 | #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) |
188 | #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) |
189 | #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) |
190 | |
191 | /* |
192 | * struct slab_rcu |
193 | * |
194 | * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to |
195 | * arrange for kmem_freepages to be called via RCU. This is useful if |
196 | * we need to approach a kernel structure obliquely, from its address |
197 | * obtained without the usual locking. We can lock the structure to |
198 | * stabilize it and check it's still at the given address, only if we |
199 | * can be sure that the memory has not been meanwhile reused for some |
200 | * other kind of object (which our subsystem's lock might corrupt). |
201 | * |
202 | * rcu_read_lock before reading the address, then rcu_read_unlock after |
203 | * taking the spinlock within the structure expected at that address. |
204 | */ |
205 | struct slab_rcu { |
206 | struct rcu_head head; |
207 | struct kmem_cache *cachep; |
208 | void *addr; |
209 | }; |
210 | |
211 | /* |
212 | * struct slab |
213 | * |
214 | * Manages the objs in a slab. Placed either at the beginning of mem allocated |
215 | * for a slab, or allocated from an general cache. |
216 | * Slabs are chained into three list: fully used, partial, fully free slabs. |
217 | */ |
218 | struct slab { |
219 | union { |
220 | struct { |
221 | struct list_head list; |
222 | unsigned long colouroff; |
223 | void *s_mem; /* including colour offset */ |
224 | unsigned int inuse; /* num of objs active in slab */ |
225 | kmem_bufctl_t free; |
226 | unsigned short nodeid; |
227 | }; |
228 | struct slab_rcu __slab_cover_slab_rcu; |
229 | }; |
230 | }; |
231 | |
232 | /* |
233 | * struct array_cache |
234 | * |
235 | * Purpose: |
236 | * - LIFO ordering, to hand out cache-warm objects from _alloc |
237 | * - reduce the number of linked list operations |
238 | * - reduce spinlock operations |
239 | * |
240 | * The limit is stored in the per-cpu structure to reduce the data cache |
241 | * footprint. |
242 | * |
243 | */ |
244 | struct array_cache { |
245 | unsigned int avail; |
246 | unsigned int limit; |
247 | unsigned int batchcount; |
248 | unsigned int touched; |
249 | spinlock_t lock; |
250 | void *entry[]; /* |
251 | * Must have this definition in here for the proper |
252 | * alignment of array_cache. Also simplifies accessing |
253 | * the entries. |
254 | * |
255 | * Entries should not be directly dereferenced as |
256 | * entries belonging to slabs marked pfmemalloc will |
257 | * have the lower bits set SLAB_OBJ_PFMEMALLOC |
258 | */ |
259 | }; |
260 | |
261 | #define SLAB_OBJ_PFMEMALLOC 1 |
262 | static inline bool is_obj_pfmemalloc(void *objp) |
263 | { |
264 | return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; |
265 | } |
266 | |
267 | static inline void set_obj_pfmemalloc(void **objp) |
268 | { |
269 | *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); |
270 | return; |
271 | } |
272 | |
273 | static inline void clear_obj_pfmemalloc(void **objp) |
274 | { |
275 | *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); |
276 | } |
277 | |
278 | /* |
279 | * bootstrap: The caches do not work without cpuarrays anymore, but the |
280 | * cpuarrays are allocated from the generic caches... |
281 | */ |
282 | #define BOOT_CPUCACHE_ENTRIES 1 |
283 | struct arraycache_init { |
284 | struct array_cache cache; |
285 | void *entries[BOOT_CPUCACHE_ENTRIES]; |
286 | }; |
287 | |
288 | /* |
289 | * Need this for bootstrapping a per node allocator. |
290 | */ |
291 | #define NUM_INIT_LISTS (3 * MAX_NUMNODES) |
292 | static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; |
293 | #define CACHE_CACHE 0 |
294 | #define SIZE_AC MAX_NUMNODES |
295 | #define SIZE_NODE (2 * MAX_NUMNODES) |
296 | |
297 | static int drain_freelist(struct kmem_cache *cache, |
298 | struct kmem_cache_node *n, int tofree); |
299 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, |
300 | int node); |
301 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); |
302 | static void cache_reap(struct work_struct *unused); |
303 | |
304 | static int slab_early_init = 1; |
305 | |
306 | #define INDEX_AC kmalloc_index(sizeof(struct arraycache_init)) |
307 | #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) |
308 | |
309 | static void kmem_cache_node_init(struct kmem_cache_node *parent) |
310 | { |
311 | INIT_LIST_HEAD(&parent->slabs_full); |
312 | INIT_LIST_HEAD(&parent->slabs_partial); |
313 | INIT_LIST_HEAD(&parent->slabs_free); |
314 | parent->shared = NULL; |
315 | parent->alien = NULL; |
316 | parent->colour_next = 0; |
317 | spin_lock_init(&parent->list_lock); |
318 | parent->free_objects = 0; |
319 | parent->free_touched = 0; |
320 | } |
321 | |
322 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ |
323 | do { \ |
324 | INIT_LIST_HEAD(listp); \ |
325 | list_splice(&(cachep->node[nodeid]->slab), listp); \ |
326 | } while (0) |
327 | |
328 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ |
329 | do { \ |
330 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ |
331 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ |
332 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ |
333 | } while (0) |
334 | |
335 | #define CFLGS_OFF_SLAB (0x80000000UL) |
336 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
337 | |
338 | #define BATCHREFILL_LIMIT 16 |
339 | /* |
340 | * Optimization question: fewer reaps means less probability for unnessary |
341 | * cpucache drain/refill cycles. |
342 | * |
343 | * OTOH the cpuarrays can contain lots of objects, |
344 | * which could lock up otherwise freeable slabs. |
345 | */ |
346 | #define REAPTIMEOUT_CPUC (2*HZ) |
347 | #define REAPTIMEOUT_LIST3 (4*HZ) |
348 | |
349 | #if STATS |
350 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
351 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
352 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
353 | #define STATS_INC_GROWN(x) ((x)->grown++) |
354 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) |
355 | #define STATS_SET_HIGH(x) \ |
356 | do { \ |
357 | if ((x)->num_active > (x)->high_mark) \ |
358 | (x)->high_mark = (x)->num_active; \ |
359 | } while (0) |
360 | #define STATS_INC_ERR(x) ((x)->errors++) |
361 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
362 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
363 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) |
364 | #define STATS_SET_FREEABLE(x, i) \ |
365 | do { \ |
366 | if ((x)->max_freeable < i) \ |
367 | (x)->max_freeable = i; \ |
368 | } while (0) |
369 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
370 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
371 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
372 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
373 | #else |
374 | #define STATS_INC_ACTIVE(x) do { } while (0) |
375 | #define STATS_DEC_ACTIVE(x) do { } while (0) |
376 | #define STATS_INC_ALLOCED(x) do { } while (0) |
377 | #define STATS_INC_GROWN(x) do { } while (0) |
378 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) |
379 | #define STATS_SET_HIGH(x) do { } while (0) |
380 | #define STATS_INC_ERR(x) do { } while (0) |
381 | #define STATS_INC_NODEALLOCS(x) do { } while (0) |
382 | #define STATS_INC_NODEFREES(x) do { } while (0) |
383 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) |
384 | #define STATS_SET_FREEABLE(x, i) do { } while (0) |
385 | #define STATS_INC_ALLOCHIT(x) do { } while (0) |
386 | #define STATS_INC_ALLOCMISS(x) do { } while (0) |
387 | #define STATS_INC_FREEHIT(x) do { } while (0) |
388 | #define STATS_INC_FREEMISS(x) do { } while (0) |
389 | #endif |
390 | |
391 | #if DEBUG |
392 | |
393 | /* |
394 | * memory layout of objects: |
395 | * 0 : objp |
396 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that |
397 | * the end of an object is aligned with the end of the real |
398 | * allocation. Catches writes behind the end of the allocation. |
399 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: |
400 | * redzone word. |
401 | * cachep->obj_offset: The real object. |
402 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
403 | * cachep->size - 1* BYTES_PER_WORD: last caller address |
404 | * [BYTES_PER_WORD long] |
405 | */ |
406 | static int obj_offset(struct kmem_cache *cachep) |
407 | { |
408 | return cachep->obj_offset; |
409 | } |
410 | |
411 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) |
412 | { |
413 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
414 | return (unsigned long long*) (objp + obj_offset(cachep) - |
415 | sizeof(unsigned long long)); |
416 | } |
417 | |
418 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) |
419 | { |
420 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
421 | if (cachep->flags & SLAB_STORE_USER) |
422 | return (unsigned long long *)(objp + cachep->size - |
423 | sizeof(unsigned long long) - |
424 | REDZONE_ALIGN); |
425 | return (unsigned long long *) (objp + cachep->size - |
426 | sizeof(unsigned long long)); |
427 | } |
428 | |
429 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) |
430 | { |
431 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
432 | return (void **)(objp + cachep->size - BYTES_PER_WORD); |
433 | } |
434 | |
435 | #else |
436 | |
437 | #define obj_offset(x) 0 |
438 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
439 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
440 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
441 | |
442 | #endif |
443 | |
444 | /* |
445 | * Do not go above this order unless 0 objects fit into the slab or |
446 | * overridden on the command line. |
447 | */ |
448 | #define SLAB_MAX_ORDER_HI 1 |
449 | #define SLAB_MAX_ORDER_LO 0 |
450 | static int slab_max_order = SLAB_MAX_ORDER_LO; |
451 | static bool slab_max_order_set __initdata; |
452 | |
453 | static inline struct kmem_cache *virt_to_cache(const void *obj) |
454 | { |
455 | struct page *page = virt_to_head_page(obj); |
456 | return page->slab_cache; |
457 | } |
458 | |
459 | static inline struct slab *virt_to_slab(const void *obj) |
460 | { |
461 | struct page *page = virt_to_head_page(obj); |
462 | |
463 | VM_BUG_ON(!PageSlab(page)); |
464 | return page->slab_page; |
465 | } |
466 | |
467 | static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, |
468 | unsigned int idx) |
469 | { |
470 | return slab->s_mem + cache->size * idx; |
471 | } |
472 | |
473 | /* |
474 | * We want to avoid an expensive divide : (offset / cache->size) |
475 | * Using the fact that size is a constant for a particular cache, |
476 | * we can replace (offset / cache->size) by |
477 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) |
478 | */ |
479 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, |
480 | const struct slab *slab, void *obj) |
481 | { |
482 | u32 offset = (obj - slab->s_mem); |
483 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); |
484 | } |
485 | |
486 | static struct arraycache_init initarray_generic = |
487 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
488 | |
489 | /* internal cache of cache description objs */ |
490 | static struct kmem_cache kmem_cache_boot = { |
491 | .batchcount = 1, |
492 | .limit = BOOT_CPUCACHE_ENTRIES, |
493 | .shared = 1, |
494 | .size = sizeof(struct kmem_cache), |
495 | .name = "kmem_cache", |
496 | }; |
497 | |
498 | #define BAD_ALIEN_MAGIC 0x01020304ul |
499 | |
500 | #ifdef CONFIG_LOCKDEP |
501 | |
502 | /* |
503 | * Slab sometimes uses the kmalloc slabs to store the slab headers |
504 | * for other slabs "off slab". |
505 | * The locking for this is tricky in that it nests within the locks |
506 | * of all other slabs in a few places; to deal with this special |
507 | * locking we put on-slab caches into a separate lock-class. |
508 | * |
509 | * We set lock class for alien array caches which are up during init. |
510 | * The lock annotation will be lost if all cpus of a node goes down and |
511 | * then comes back up during hotplug |
512 | */ |
513 | static struct lock_class_key on_slab_l3_key; |
514 | static struct lock_class_key on_slab_alc_key; |
515 | |
516 | static struct lock_class_key debugobj_l3_key; |
517 | static struct lock_class_key debugobj_alc_key; |
518 | |
519 | static void slab_set_lock_classes(struct kmem_cache *cachep, |
520 | struct lock_class_key *l3_key, struct lock_class_key *alc_key, |
521 | int q) |
522 | { |
523 | struct array_cache **alc; |
524 | struct kmem_cache_node *n; |
525 | int r; |
526 | |
527 | n = cachep->node[q]; |
528 | if (!n) |
529 | return; |
530 | |
531 | lockdep_set_class(&n->list_lock, l3_key); |
532 | alc = n->alien; |
533 | /* |
534 | * FIXME: This check for BAD_ALIEN_MAGIC |
535 | * should go away when common slab code is taught to |
536 | * work even without alien caches. |
537 | * Currently, non NUMA code returns BAD_ALIEN_MAGIC |
538 | * for alloc_alien_cache, |
539 | */ |
540 | if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) |
541 | return; |
542 | for_each_node(r) { |
543 | if (alc[r]) |
544 | lockdep_set_class(&alc[r]->lock, alc_key); |
545 | } |
546 | } |
547 | |
548 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
549 | { |
550 | slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node); |
551 | } |
552 | |
553 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
554 | { |
555 | int node; |
556 | |
557 | for_each_online_node(node) |
558 | slab_set_debugobj_lock_classes_node(cachep, node); |
559 | } |
560 | |
561 | static void init_node_lock_keys(int q) |
562 | { |
563 | int i; |
564 | |
565 | if (slab_state < UP) |
566 | return; |
567 | |
568 | for (i = 1; i <= KMALLOC_SHIFT_HIGH; i++) { |
569 | struct kmem_cache_node *n; |
570 | struct kmem_cache *cache = kmalloc_caches[i]; |
571 | |
572 | if (!cache) |
573 | continue; |
574 | |
575 | n = cache->node[q]; |
576 | if (!n || OFF_SLAB(cache)) |
577 | continue; |
578 | |
579 | slab_set_lock_classes(cache, &on_slab_l3_key, |
580 | &on_slab_alc_key, q); |
581 | } |
582 | } |
583 | |
584 | static void on_slab_lock_classes_node(struct kmem_cache *cachep, int q) |
585 | { |
586 | if (!cachep->node[q]) |
587 | return; |
588 | |
589 | slab_set_lock_classes(cachep, &on_slab_l3_key, |
590 | &on_slab_alc_key, q); |
591 | } |
592 | |
593 | static inline void on_slab_lock_classes(struct kmem_cache *cachep) |
594 | { |
595 | int node; |
596 | |
597 | VM_BUG_ON(OFF_SLAB(cachep)); |
598 | for_each_node(node) |
599 | on_slab_lock_classes_node(cachep, node); |
600 | } |
601 | |
602 | static inline void init_lock_keys(void) |
603 | { |
604 | int node; |
605 | |
606 | for_each_node(node) |
607 | init_node_lock_keys(node); |
608 | } |
609 | #else |
610 | static void init_node_lock_keys(int q) |
611 | { |
612 | } |
613 | |
614 | static inline void init_lock_keys(void) |
615 | { |
616 | } |
617 | |
618 | static inline void on_slab_lock_classes(struct kmem_cache *cachep) |
619 | { |
620 | } |
621 | |
622 | static inline void on_slab_lock_classes_node(struct kmem_cache *cachep, int node) |
623 | { |
624 | } |
625 | |
626 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
627 | { |
628 | } |
629 | |
630 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
631 | { |
632 | } |
633 | #endif |
634 | |
635 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); |
636 | |
637 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) |
638 | { |
639 | return cachep->array[smp_processor_id()]; |
640 | } |
641 | |
642 | static size_t slab_mgmt_size(size_t nr_objs, size_t align) |
643 | { |
644 | return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); |
645 | } |
646 | |
647 | /* |
648 | * Calculate the number of objects and left-over bytes for a given buffer size. |
649 | */ |
650 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, |
651 | size_t align, int flags, size_t *left_over, |
652 | unsigned int *num) |
653 | { |
654 | int nr_objs; |
655 | size_t mgmt_size; |
656 | size_t slab_size = PAGE_SIZE << gfporder; |
657 | |
658 | /* |
659 | * The slab management structure can be either off the slab or |
660 | * on it. For the latter case, the memory allocated for a |
661 | * slab is used for: |
662 | * |
663 | * - The struct slab |
664 | * - One kmem_bufctl_t for each object |
665 | * - Padding to respect alignment of @align |
666 | * - @buffer_size bytes for each object |
667 | * |
668 | * If the slab management structure is off the slab, then the |
669 | * alignment will already be calculated into the size. Because |
670 | * the slabs are all pages aligned, the objects will be at the |
671 | * correct alignment when allocated. |
672 | */ |
673 | if (flags & CFLGS_OFF_SLAB) { |
674 | mgmt_size = 0; |
675 | nr_objs = slab_size / buffer_size; |
676 | |
677 | if (nr_objs > SLAB_LIMIT) |
678 | nr_objs = SLAB_LIMIT; |
679 | } else { |
680 | /* |
681 | * Ignore padding for the initial guess. The padding |
682 | * is at most @align-1 bytes, and @buffer_size is at |
683 | * least @align. In the worst case, this result will |
684 | * be one greater than the number of objects that fit |
685 | * into the memory allocation when taking the padding |
686 | * into account. |
687 | */ |
688 | nr_objs = (slab_size - sizeof(struct slab)) / |
689 | (buffer_size + sizeof(kmem_bufctl_t)); |
690 | |
691 | /* |
692 | * This calculated number will be either the right |
693 | * amount, or one greater than what we want. |
694 | */ |
695 | if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size |
696 | > slab_size) |
697 | nr_objs--; |
698 | |
699 | if (nr_objs > SLAB_LIMIT) |
700 | nr_objs = SLAB_LIMIT; |
701 | |
702 | mgmt_size = slab_mgmt_size(nr_objs, align); |
703 | } |
704 | *num = nr_objs; |
705 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; |
706 | } |
707 | |
708 | #if DEBUG |
709 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) |
710 | |
711 | static void __slab_error(const char *function, struct kmem_cache *cachep, |
712 | char *msg) |
713 | { |
714 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
715 | function, cachep->name, msg); |
716 | dump_stack(); |
717 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
718 | } |
719 | #endif |
720 | |
721 | /* |
722 | * By default on NUMA we use alien caches to stage the freeing of |
723 | * objects allocated from other nodes. This causes massive memory |
724 | * inefficiencies when using fake NUMA setup to split memory into a |
725 | * large number of small nodes, so it can be disabled on the command |
726 | * line |
727 | */ |
728 | |
729 | static int use_alien_caches __read_mostly = 1; |
730 | static int __init noaliencache_setup(char *s) |
731 | { |
732 | use_alien_caches = 0; |
733 | return 1; |
734 | } |
735 | __setup("noaliencache", noaliencache_setup); |
736 | |
737 | static int __init slab_max_order_setup(char *str) |
738 | { |
739 | get_option(&str, &slab_max_order); |
740 | slab_max_order = slab_max_order < 0 ? 0 : |
741 | min(slab_max_order, MAX_ORDER - 1); |
742 | slab_max_order_set = true; |
743 | |
744 | return 1; |
745 | } |
746 | __setup("slab_max_order=", slab_max_order_setup); |
747 | |
748 | #ifdef CONFIG_NUMA |
749 | /* |
750 | * Special reaping functions for NUMA systems called from cache_reap(). |
751 | * These take care of doing round robin flushing of alien caches (containing |
752 | * objects freed on different nodes from which they were allocated) and the |
753 | * flushing of remote pcps by calling drain_node_pages. |
754 | */ |
755 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); |
756 | |
757 | static void init_reap_node(int cpu) |
758 | { |
759 | int node; |
760 | |
761 | node = next_node(cpu_to_mem(cpu), node_online_map); |
762 | if (node == MAX_NUMNODES) |
763 | node = first_node(node_online_map); |
764 | |
765 | per_cpu(slab_reap_node, cpu) = node; |
766 | } |
767 | |
768 | static void next_reap_node(void) |
769 | { |
770 | int node = __this_cpu_read(slab_reap_node); |
771 | |
772 | node = next_node(node, node_online_map); |
773 | if (unlikely(node >= MAX_NUMNODES)) |
774 | node = first_node(node_online_map); |
775 | __this_cpu_write(slab_reap_node, node); |
776 | } |
777 | |
778 | #else |
779 | #define init_reap_node(cpu) do { } while (0) |
780 | #define next_reap_node(void) do { } while (0) |
781 | #endif |
782 | |
783 | /* |
784 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
785 | * via the workqueue/eventd. |
786 | * Add the CPU number into the expiration time to minimize the possibility of |
787 | * the CPUs getting into lockstep and contending for the global cache chain |
788 | * lock. |
789 | */ |
790 | static void start_cpu_timer(int cpu) |
791 | { |
792 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); |
793 | |
794 | /* |
795 | * When this gets called from do_initcalls via cpucache_init(), |
796 | * init_workqueues() has already run, so keventd will be setup |
797 | * at that time. |
798 | */ |
799 | if (keventd_up() && reap_work->work.func == NULL) { |
800 | init_reap_node(cpu); |
801 | INIT_DEFERRABLE_WORK(reap_work, cache_reap); |
802 | schedule_delayed_work_on(cpu, reap_work, |
803 | __round_jiffies_relative(HZ, cpu)); |
804 | } |
805 | } |
806 | |
807 | static struct array_cache *alloc_arraycache(int node, int entries, |
808 | int batchcount, gfp_t gfp) |
809 | { |
810 | int memsize = sizeof(void *) * entries + sizeof(struct array_cache); |
811 | struct array_cache *nc = NULL; |
812 | |
813 | nc = kmalloc_node(memsize, gfp, node); |
814 | /* |
815 | * The array_cache structures contain pointers to free object. |
816 | * However, when such objects are allocated or transferred to another |
817 | * cache the pointers are not cleared and they could be counted as |
818 | * valid references during a kmemleak scan. Therefore, kmemleak must |
819 | * not scan such objects. |
820 | */ |
821 | kmemleak_no_scan(nc); |
822 | if (nc) { |
823 | nc->avail = 0; |
824 | nc->limit = entries; |
825 | nc->batchcount = batchcount; |
826 | nc->touched = 0; |
827 | spin_lock_init(&nc->lock); |
828 | } |
829 | return nc; |
830 | } |
831 | |
832 | static inline bool is_slab_pfmemalloc(struct slab *slabp) |
833 | { |
834 | struct page *page = virt_to_page(slabp->s_mem); |
835 | |
836 | return PageSlabPfmemalloc(page); |
837 | } |
838 | |
839 | /* Clears pfmemalloc_active if no slabs have pfmalloc set */ |
840 | static void recheck_pfmemalloc_active(struct kmem_cache *cachep, |
841 | struct array_cache *ac) |
842 | { |
843 | struct kmem_cache_node *n = cachep->node[numa_mem_id()]; |
844 | struct slab *slabp; |
845 | unsigned long flags; |
846 | |
847 | if (!pfmemalloc_active) |
848 | return; |
849 | |
850 | spin_lock_irqsave(&n->list_lock, flags); |
851 | list_for_each_entry(slabp, &n->slabs_full, list) |
852 | if (is_slab_pfmemalloc(slabp)) |
853 | goto out; |
854 | |
855 | list_for_each_entry(slabp, &n->slabs_partial, list) |
856 | if (is_slab_pfmemalloc(slabp)) |
857 | goto out; |
858 | |
859 | list_for_each_entry(slabp, &n->slabs_free, list) |
860 | if (is_slab_pfmemalloc(slabp)) |
861 | goto out; |
862 | |
863 | pfmemalloc_active = false; |
864 | out: |
865 | spin_unlock_irqrestore(&n->list_lock, flags); |
866 | } |
867 | |
868 | static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, |
869 | gfp_t flags, bool force_refill) |
870 | { |
871 | int i; |
872 | void *objp = ac->entry[--ac->avail]; |
873 | |
874 | /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ |
875 | if (unlikely(is_obj_pfmemalloc(objp))) { |
876 | struct kmem_cache_node *n; |
877 | |
878 | if (gfp_pfmemalloc_allowed(flags)) { |
879 | clear_obj_pfmemalloc(&objp); |
880 | return objp; |
881 | } |
882 | |
883 | /* The caller cannot use PFMEMALLOC objects, find another one */ |
884 | for (i = 0; i < ac->avail; i++) { |
885 | /* If a !PFMEMALLOC object is found, swap them */ |
886 | if (!is_obj_pfmemalloc(ac->entry[i])) { |
887 | objp = ac->entry[i]; |
888 | ac->entry[i] = ac->entry[ac->avail]; |
889 | ac->entry[ac->avail] = objp; |
890 | return objp; |
891 | } |
892 | } |
893 | |
894 | /* |
895 | * If there are empty slabs on the slabs_free list and we are |
896 | * being forced to refill the cache, mark this one !pfmemalloc. |
897 | */ |
898 | n = cachep->node[numa_mem_id()]; |
899 | if (!list_empty(&n->slabs_free) && force_refill) { |
900 | struct slab *slabp = virt_to_slab(objp); |
901 | ClearPageSlabPfmemalloc(virt_to_head_page(slabp->s_mem)); |
902 | clear_obj_pfmemalloc(&objp); |
903 | recheck_pfmemalloc_active(cachep, ac); |
904 | return objp; |
905 | } |
906 | |
907 | /* No !PFMEMALLOC objects available */ |
908 | ac->avail++; |
909 | objp = NULL; |
910 | } |
911 | |
912 | return objp; |
913 | } |
914 | |
915 | static inline void *ac_get_obj(struct kmem_cache *cachep, |
916 | struct array_cache *ac, gfp_t flags, bool force_refill) |
917 | { |
918 | void *objp; |
919 | |
920 | if (unlikely(sk_memalloc_socks())) |
921 | objp = __ac_get_obj(cachep, ac, flags, force_refill); |
922 | else |
923 | objp = ac->entry[--ac->avail]; |
924 | |
925 | return objp; |
926 | } |
927 | |
928 | static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
929 | void *objp) |
930 | { |
931 | if (unlikely(pfmemalloc_active)) { |
932 | /* Some pfmemalloc slabs exist, check if this is one */ |
933 | struct page *page = virt_to_head_page(objp); |
934 | if (PageSlabPfmemalloc(page)) |
935 | set_obj_pfmemalloc(&objp); |
936 | } |
937 | |
938 | return objp; |
939 | } |
940 | |
941 | static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
942 | void *objp) |
943 | { |
944 | if (unlikely(sk_memalloc_socks())) |
945 | objp = __ac_put_obj(cachep, ac, objp); |
946 | |
947 | ac->entry[ac->avail++] = objp; |
948 | } |
949 | |
950 | /* |
951 | * Transfer objects in one arraycache to another. |
952 | * Locking must be handled by the caller. |
953 | * |
954 | * Return the number of entries transferred. |
955 | */ |
956 | static int transfer_objects(struct array_cache *to, |
957 | struct array_cache *from, unsigned int max) |
958 | { |
959 | /* Figure out how many entries to transfer */ |
960 | int nr = min3(from->avail, max, to->limit - to->avail); |
961 | |
962 | if (!nr) |
963 | return 0; |
964 | |
965 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, |
966 | sizeof(void *) *nr); |
967 | |
968 | from->avail -= nr; |
969 | to->avail += nr; |
970 | return nr; |
971 | } |
972 | |
973 | #ifndef CONFIG_NUMA |
974 | |
975 | #define drain_alien_cache(cachep, alien) do { } while (0) |
976 | #define reap_alien(cachep, n) do { } while (0) |
977 | |
978 | static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
979 | { |
980 | return (struct array_cache **)BAD_ALIEN_MAGIC; |
981 | } |
982 | |
983 | static inline void free_alien_cache(struct array_cache **ac_ptr) |
984 | { |
985 | } |
986 | |
987 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
988 | { |
989 | return 0; |
990 | } |
991 | |
992 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, |
993 | gfp_t flags) |
994 | { |
995 | return NULL; |
996 | } |
997 | |
998 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, |
999 | gfp_t flags, int nodeid) |
1000 | { |
1001 | return NULL; |
1002 | } |
1003 | |
1004 | #else /* CONFIG_NUMA */ |
1005 | |
1006 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); |
1007 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); |
1008 | |
1009 | static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
1010 | { |
1011 | struct array_cache **ac_ptr; |
1012 | int memsize = sizeof(void *) * nr_node_ids; |
1013 | int i; |
1014 | |
1015 | if (limit > 1) |
1016 | limit = 12; |
1017 | ac_ptr = kzalloc_node(memsize, gfp, node); |
1018 | if (ac_ptr) { |
1019 | for_each_node(i) { |
1020 | if (i == node || !node_online(i)) |
1021 | continue; |
1022 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); |
1023 | if (!ac_ptr[i]) { |
1024 | for (i--; i >= 0; i--) |
1025 | kfree(ac_ptr[i]); |
1026 | kfree(ac_ptr); |
1027 | return NULL; |
1028 | } |
1029 | } |
1030 | } |
1031 | return ac_ptr; |
1032 | } |
1033 | |
1034 | static void free_alien_cache(struct array_cache **ac_ptr) |
1035 | { |
1036 | int i; |
1037 | |
1038 | if (!ac_ptr) |
1039 | return; |
1040 | for_each_node(i) |
1041 | kfree(ac_ptr[i]); |
1042 | kfree(ac_ptr); |
1043 | } |
1044 | |
1045 | static void __drain_alien_cache(struct kmem_cache *cachep, |
1046 | struct array_cache *ac, int node) |
1047 | { |
1048 | struct kmem_cache_node *n = cachep->node[node]; |
1049 | |
1050 | if (ac->avail) { |
1051 | spin_lock(&n->list_lock); |
1052 | /* |
1053 | * Stuff objects into the remote nodes shared array first. |
1054 | * That way we could avoid the overhead of putting the objects |
1055 | * into the free lists and getting them back later. |
1056 | */ |
1057 | if (n->shared) |
1058 | transfer_objects(n->shared, ac, ac->limit); |
1059 | |
1060 | free_block(cachep, ac->entry, ac->avail, node); |
1061 | ac->avail = 0; |
1062 | spin_unlock(&n->list_lock); |
1063 | } |
1064 | } |
1065 | |
1066 | /* |
1067 | * Called from cache_reap() to regularly drain alien caches round robin. |
1068 | */ |
1069 | static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) |
1070 | { |
1071 | int node = __this_cpu_read(slab_reap_node); |
1072 | |
1073 | if (n->alien) { |
1074 | struct array_cache *ac = n->alien[node]; |
1075 | |
1076 | if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { |
1077 | __drain_alien_cache(cachep, ac, node); |
1078 | spin_unlock_irq(&ac->lock); |
1079 | } |
1080 | } |
1081 | } |
1082 | |
1083 | static void drain_alien_cache(struct kmem_cache *cachep, |
1084 | struct array_cache **alien) |
1085 | { |
1086 | int i = 0; |
1087 | struct array_cache *ac; |
1088 | unsigned long flags; |
1089 | |
1090 | for_each_online_node(i) { |
1091 | ac = alien[i]; |
1092 | if (ac) { |
1093 | spin_lock_irqsave(&ac->lock, flags); |
1094 | __drain_alien_cache(cachep, ac, i); |
1095 | spin_unlock_irqrestore(&ac->lock, flags); |
1096 | } |
1097 | } |
1098 | } |
1099 | |
1100 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
1101 | { |
1102 | struct slab *slabp = virt_to_slab(objp); |
1103 | int nodeid = slabp->nodeid; |
1104 | struct kmem_cache_node *n; |
1105 | struct array_cache *alien = NULL; |
1106 | int node; |
1107 | |
1108 | node = numa_mem_id(); |
1109 | |
1110 | /* |
1111 | * Make sure we are not freeing a object from another node to the array |
1112 | * cache on this cpu. |
1113 | */ |
1114 | if (likely(slabp->nodeid == node)) |
1115 | return 0; |
1116 | |
1117 | n = cachep->node[node]; |
1118 | STATS_INC_NODEFREES(cachep); |
1119 | if (n->alien && n->alien[nodeid]) { |
1120 | alien = n->alien[nodeid]; |
1121 | spin_lock(&alien->lock); |
1122 | if (unlikely(alien->avail == alien->limit)) { |
1123 | STATS_INC_ACOVERFLOW(cachep); |
1124 | __drain_alien_cache(cachep, alien, nodeid); |
1125 | } |
1126 | ac_put_obj(cachep, alien, objp); |
1127 | spin_unlock(&alien->lock); |
1128 | } else { |
1129 | spin_lock(&(cachep->node[nodeid])->list_lock); |
1130 | free_block(cachep, &objp, 1, nodeid); |
1131 | spin_unlock(&(cachep->node[nodeid])->list_lock); |
1132 | } |
1133 | return 1; |
1134 | } |
1135 | #endif |
1136 | |
1137 | /* |
1138 | * Allocates and initializes node for a node on each slab cache, used for |
1139 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node |
1140 | * will be allocated off-node since memory is not yet online for the new node. |
1141 | * When hotplugging memory or a cpu, existing node are not replaced if |
1142 | * already in use. |
1143 | * |
1144 | * Must hold slab_mutex. |
1145 | */ |
1146 | static int init_cache_node_node(int node) |
1147 | { |
1148 | struct kmem_cache *cachep; |
1149 | struct kmem_cache_node *n; |
1150 | const int memsize = sizeof(struct kmem_cache_node); |
1151 | |
1152 | list_for_each_entry(cachep, &slab_caches, list) { |
1153 | /* |
1154 | * Set up the size64 kmemlist for cpu before we can |
1155 | * begin anything. Make sure some other cpu on this |
1156 | * node has not already allocated this |
1157 | */ |
1158 | if (!cachep->node[node]) { |
1159 | n = kmalloc_node(memsize, GFP_KERNEL, node); |
1160 | if (!n) |
1161 | return -ENOMEM; |
1162 | kmem_cache_node_init(n); |
1163 | n->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
1164 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1165 | |
1166 | /* |
1167 | * The l3s don't come and go as CPUs come and |
1168 | * go. slab_mutex is sufficient |
1169 | * protection here. |
1170 | */ |
1171 | cachep->node[node] = n; |
1172 | } |
1173 | |
1174 | spin_lock_irq(&cachep->node[node]->list_lock); |
1175 | cachep->node[node]->free_limit = |
1176 | (1 + nr_cpus_node(node)) * |
1177 | cachep->batchcount + cachep->num; |
1178 | spin_unlock_irq(&cachep->node[node]->list_lock); |
1179 | } |
1180 | return 0; |
1181 | } |
1182 | |
1183 | static inline int slabs_tofree(struct kmem_cache *cachep, |
1184 | struct kmem_cache_node *n) |
1185 | { |
1186 | return (n->free_objects + cachep->num - 1) / cachep->num; |
1187 | } |
1188 | |
1189 | static void cpuup_canceled(long cpu) |
1190 | { |
1191 | struct kmem_cache *cachep; |
1192 | struct kmem_cache_node *n = NULL; |
1193 | int node = cpu_to_mem(cpu); |
1194 | const struct cpumask *mask = cpumask_of_node(node); |
1195 | |
1196 | list_for_each_entry(cachep, &slab_caches, list) { |
1197 | struct array_cache *nc; |
1198 | struct array_cache *shared; |
1199 | struct array_cache **alien; |
1200 | |
1201 | /* cpu is dead; no one can alloc from it. */ |
1202 | nc = cachep->array[cpu]; |
1203 | cachep->array[cpu] = NULL; |
1204 | n = cachep->node[node]; |
1205 | |
1206 | if (!n) |
1207 | goto free_array_cache; |
1208 | |
1209 | spin_lock_irq(&n->list_lock); |
1210 | |
1211 | /* Free limit for this kmem_cache_node */ |
1212 | n->free_limit -= cachep->batchcount; |
1213 | if (nc) |
1214 | free_block(cachep, nc->entry, nc->avail, node); |
1215 | |
1216 | if (!cpumask_empty(mask)) { |
1217 | spin_unlock_irq(&n->list_lock); |
1218 | goto free_array_cache; |
1219 | } |
1220 | |
1221 | shared = n->shared; |
1222 | if (shared) { |
1223 | free_block(cachep, shared->entry, |
1224 | shared->avail, node); |
1225 | n->shared = NULL; |
1226 | } |
1227 | |
1228 | alien = n->alien; |
1229 | n->alien = NULL; |
1230 | |
1231 | spin_unlock_irq(&n->list_lock); |
1232 | |
1233 | kfree(shared); |
1234 | if (alien) { |
1235 | drain_alien_cache(cachep, alien); |
1236 | free_alien_cache(alien); |
1237 | } |
1238 | free_array_cache: |
1239 | kfree(nc); |
1240 | } |
1241 | /* |
1242 | * In the previous loop, all the objects were freed to |
1243 | * the respective cache's slabs, now we can go ahead and |
1244 | * shrink each nodelist to its limit. |
1245 | */ |
1246 | list_for_each_entry(cachep, &slab_caches, list) { |
1247 | n = cachep->node[node]; |
1248 | if (!n) |
1249 | continue; |
1250 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
1251 | } |
1252 | } |
1253 | |
1254 | static int cpuup_prepare(long cpu) |
1255 | { |
1256 | struct kmem_cache *cachep; |
1257 | struct kmem_cache_node *n = NULL; |
1258 | int node = cpu_to_mem(cpu); |
1259 | int err; |
1260 | |
1261 | /* |
1262 | * We need to do this right in the beginning since |
1263 | * alloc_arraycache's are going to use this list. |
1264 | * kmalloc_node allows us to add the slab to the right |
1265 | * kmem_cache_node and not this cpu's kmem_cache_node |
1266 | */ |
1267 | err = init_cache_node_node(node); |
1268 | if (err < 0) |
1269 | goto bad; |
1270 | |
1271 | /* |
1272 | * Now we can go ahead with allocating the shared arrays and |
1273 | * array caches |
1274 | */ |
1275 | list_for_each_entry(cachep, &slab_caches, list) { |
1276 | struct array_cache *nc; |
1277 | struct array_cache *shared = NULL; |
1278 | struct array_cache **alien = NULL; |
1279 | |
1280 | nc = alloc_arraycache(node, cachep->limit, |
1281 | cachep->batchcount, GFP_KERNEL); |
1282 | if (!nc) |
1283 | goto bad; |
1284 | if (cachep->shared) { |
1285 | shared = alloc_arraycache(node, |
1286 | cachep->shared * cachep->batchcount, |
1287 | 0xbaadf00d, GFP_KERNEL); |
1288 | if (!shared) { |
1289 | kfree(nc); |
1290 | goto bad; |
1291 | } |
1292 | } |
1293 | if (use_alien_caches) { |
1294 | alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); |
1295 | if (!alien) { |
1296 | kfree(shared); |
1297 | kfree(nc); |
1298 | goto bad; |
1299 | } |
1300 | } |
1301 | cachep->array[cpu] = nc; |
1302 | n = cachep->node[node]; |
1303 | BUG_ON(!n); |
1304 | |
1305 | spin_lock_irq(&n->list_lock); |
1306 | if (!n->shared) { |
1307 | /* |
1308 | * We are serialised from CPU_DEAD or |
1309 | * CPU_UP_CANCELLED by the cpucontrol lock |
1310 | */ |
1311 | n->shared = shared; |
1312 | shared = NULL; |
1313 | } |
1314 | #ifdef CONFIG_NUMA |
1315 | if (!n->alien) { |
1316 | n->alien = alien; |
1317 | alien = NULL; |
1318 | } |
1319 | #endif |
1320 | spin_unlock_irq(&n->list_lock); |
1321 | kfree(shared); |
1322 | free_alien_cache(alien); |
1323 | if (cachep->flags & SLAB_DEBUG_OBJECTS) |
1324 | slab_set_debugobj_lock_classes_node(cachep, node); |
1325 | else if (!OFF_SLAB(cachep) && |
1326 | !(cachep->flags & SLAB_DESTROY_BY_RCU)) |
1327 | on_slab_lock_classes_node(cachep, node); |
1328 | } |
1329 | init_node_lock_keys(node); |
1330 | |
1331 | return 0; |
1332 | bad: |
1333 | cpuup_canceled(cpu); |
1334 | return -ENOMEM; |
1335 | } |
1336 | |
1337 | static int cpuup_callback(struct notifier_block *nfb, |
1338 | unsigned long action, void *hcpu) |
1339 | { |
1340 | long cpu = (long)hcpu; |
1341 | int err = 0; |
1342 | |
1343 | switch (action) { |
1344 | case CPU_UP_PREPARE: |
1345 | case CPU_UP_PREPARE_FROZEN: |
1346 | mutex_lock(&slab_mutex); |
1347 | err = cpuup_prepare(cpu); |
1348 | mutex_unlock(&slab_mutex); |
1349 | break; |
1350 | case CPU_ONLINE: |
1351 | case CPU_ONLINE_FROZEN: |
1352 | start_cpu_timer(cpu); |
1353 | break; |
1354 | #ifdef CONFIG_HOTPLUG_CPU |
1355 | case CPU_DOWN_PREPARE: |
1356 | case CPU_DOWN_PREPARE_FROZEN: |
1357 | /* |
1358 | * Shutdown cache reaper. Note that the slab_mutex is |
1359 | * held so that if cache_reap() is invoked it cannot do |
1360 | * anything expensive but will only modify reap_work |
1361 | * and reschedule the timer. |
1362 | */ |
1363 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); |
1364 | /* Now the cache_reaper is guaranteed to be not running. */ |
1365 | per_cpu(slab_reap_work, cpu).work.func = NULL; |
1366 | break; |
1367 | case CPU_DOWN_FAILED: |
1368 | case CPU_DOWN_FAILED_FROZEN: |
1369 | start_cpu_timer(cpu); |
1370 | break; |
1371 | case CPU_DEAD: |
1372 | case CPU_DEAD_FROZEN: |
1373 | /* |
1374 | * Even if all the cpus of a node are down, we don't free the |
1375 | * kmem_cache_node of any cache. This to avoid a race between |
1376 | * cpu_down, and a kmalloc allocation from another cpu for |
1377 | * memory from the node of the cpu going down. The node |
1378 | * structure is usually allocated from kmem_cache_create() and |
1379 | * gets destroyed at kmem_cache_destroy(). |
1380 | */ |
1381 | /* fall through */ |
1382 | #endif |
1383 | case CPU_UP_CANCELED: |
1384 | case CPU_UP_CANCELED_FROZEN: |
1385 | mutex_lock(&slab_mutex); |
1386 | cpuup_canceled(cpu); |
1387 | mutex_unlock(&slab_mutex); |
1388 | break; |
1389 | } |
1390 | return notifier_from_errno(err); |
1391 | } |
1392 | |
1393 | static struct notifier_block cpucache_notifier = { |
1394 | &cpuup_callback, NULL, 0 |
1395 | }; |
1396 | |
1397 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
1398 | /* |
1399 | * Drains freelist for a node on each slab cache, used for memory hot-remove. |
1400 | * Returns -EBUSY if all objects cannot be drained so that the node is not |
1401 | * removed. |
1402 | * |
1403 | * Must hold slab_mutex. |
1404 | */ |
1405 | static int __meminit drain_cache_node_node(int node) |
1406 | { |
1407 | struct kmem_cache *cachep; |
1408 | int ret = 0; |
1409 | |
1410 | list_for_each_entry(cachep, &slab_caches, list) { |
1411 | struct kmem_cache_node *n; |
1412 | |
1413 | n = cachep->node[node]; |
1414 | if (!n) |
1415 | continue; |
1416 | |
1417 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
1418 | |
1419 | if (!list_empty(&n->slabs_full) || |
1420 | !list_empty(&n->slabs_partial)) { |
1421 | ret = -EBUSY; |
1422 | break; |
1423 | } |
1424 | } |
1425 | return ret; |
1426 | } |
1427 | |
1428 | static int __meminit slab_memory_callback(struct notifier_block *self, |
1429 | unsigned long action, void *arg) |
1430 | { |
1431 | struct memory_notify *mnb = arg; |
1432 | int ret = 0; |
1433 | int nid; |
1434 | |
1435 | nid = mnb->status_change_nid; |
1436 | if (nid < 0) |
1437 | goto out; |
1438 | |
1439 | switch (action) { |
1440 | case MEM_GOING_ONLINE: |
1441 | mutex_lock(&slab_mutex); |
1442 | ret = init_cache_node_node(nid); |
1443 | mutex_unlock(&slab_mutex); |
1444 | break; |
1445 | case MEM_GOING_OFFLINE: |
1446 | mutex_lock(&slab_mutex); |
1447 | ret = drain_cache_node_node(nid); |
1448 | mutex_unlock(&slab_mutex); |
1449 | break; |
1450 | case MEM_ONLINE: |
1451 | case MEM_OFFLINE: |
1452 | case MEM_CANCEL_ONLINE: |
1453 | case MEM_CANCEL_OFFLINE: |
1454 | break; |
1455 | } |
1456 | out: |
1457 | return notifier_from_errno(ret); |
1458 | } |
1459 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ |
1460 | |
1461 | /* |
1462 | * swap the static kmem_cache_node with kmalloced memory |
1463 | */ |
1464 | static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, |
1465 | int nodeid) |
1466 | { |
1467 | struct kmem_cache_node *ptr; |
1468 | |
1469 | ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); |
1470 | BUG_ON(!ptr); |
1471 | |
1472 | memcpy(ptr, list, sizeof(struct kmem_cache_node)); |
1473 | /* |
1474 | * Do not assume that spinlocks can be initialized via memcpy: |
1475 | */ |
1476 | spin_lock_init(&ptr->list_lock); |
1477 | |
1478 | MAKE_ALL_LISTS(cachep, ptr, nodeid); |
1479 | cachep->node[nodeid] = ptr; |
1480 | } |
1481 | |
1482 | /* |
1483 | * For setting up all the kmem_cache_node for cache whose buffer_size is same as |
1484 | * size of kmem_cache_node. |
1485 | */ |
1486 | static void __init set_up_node(struct kmem_cache *cachep, int index) |
1487 | { |
1488 | int node; |
1489 | |
1490 | for_each_online_node(node) { |
1491 | cachep->node[node] = &init_kmem_cache_node[index + node]; |
1492 | cachep->node[node]->next_reap = jiffies + |
1493 | REAPTIMEOUT_LIST3 + |
1494 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1495 | } |
1496 | } |
1497 | |
1498 | /* |
1499 | * The memory after the last cpu cache pointer is used for the |
1500 | * the node pointer. |
1501 | */ |
1502 | static void setup_node_pointer(struct kmem_cache *cachep) |
1503 | { |
1504 | cachep->node = (struct kmem_cache_node **)&cachep->array[nr_cpu_ids]; |
1505 | } |
1506 | |
1507 | /* |
1508 | * Initialisation. Called after the page allocator have been initialised and |
1509 | * before smp_init(). |
1510 | */ |
1511 | void __init kmem_cache_init(void) |
1512 | { |
1513 | int i; |
1514 | |
1515 | kmem_cache = &kmem_cache_boot; |
1516 | setup_node_pointer(kmem_cache); |
1517 | |
1518 | if (num_possible_nodes() == 1) |
1519 | use_alien_caches = 0; |
1520 | |
1521 | for (i = 0; i < NUM_INIT_LISTS; i++) |
1522 | kmem_cache_node_init(&init_kmem_cache_node[i]); |
1523 | |
1524 | set_up_node(kmem_cache, CACHE_CACHE); |
1525 | |
1526 | /* |
1527 | * Fragmentation resistance on low memory - only use bigger |
1528 | * page orders on machines with more than 32MB of memory if |
1529 | * not overridden on the command line. |
1530 | */ |
1531 | if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) |
1532 | slab_max_order = SLAB_MAX_ORDER_HI; |
1533 | |
1534 | /* Bootstrap is tricky, because several objects are allocated |
1535 | * from caches that do not exist yet: |
1536 | * 1) initialize the kmem_cache cache: it contains the struct |
1537 | * kmem_cache structures of all caches, except kmem_cache itself: |
1538 | * kmem_cache is statically allocated. |
1539 | * Initially an __init data area is used for the head array and the |
1540 | * kmem_cache_node structures, it's replaced with a kmalloc allocated |
1541 | * array at the end of the bootstrap. |
1542 | * 2) Create the first kmalloc cache. |
1543 | * The struct kmem_cache for the new cache is allocated normally. |
1544 | * An __init data area is used for the head array. |
1545 | * 3) Create the remaining kmalloc caches, with minimally sized |
1546 | * head arrays. |
1547 | * 4) Replace the __init data head arrays for kmem_cache and the first |
1548 | * kmalloc cache with kmalloc allocated arrays. |
1549 | * 5) Replace the __init data for kmem_cache_node for kmem_cache and |
1550 | * the other cache's with kmalloc allocated memory. |
1551 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. |
1552 | */ |
1553 | |
1554 | /* 1) create the kmem_cache */ |
1555 | |
1556 | /* |
1557 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids |
1558 | */ |
1559 | create_boot_cache(kmem_cache, "kmem_cache", |
1560 | offsetof(struct kmem_cache, array[nr_cpu_ids]) + |
1561 | nr_node_ids * sizeof(struct kmem_cache_node *), |
1562 | SLAB_HWCACHE_ALIGN); |
1563 | list_add(&kmem_cache->list, &slab_caches); |
1564 | |
1565 | /* 2+3) create the kmalloc caches */ |
1566 | |
1567 | /* |
1568 | * Initialize the caches that provide memory for the array cache and the |
1569 | * kmem_cache_node structures first. Without this, further allocations will |
1570 | * bug. |
1571 | */ |
1572 | |
1573 | kmalloc_caches[INDEX_AC] = create_kmalloc_cache("kmalloc-ac", |
1574 | kmalloc_size(INDEX_AC), ARCH_KMALLOC_FLAGS); |
1575 | |
1576 | if (INDEX_AC != INDEX_NODE) |
1577 | kmalloc_caches[INDEX_NODE] = |
1578 | create_kmalloc_cache("kmalloc-node", |
1579 | kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); |
1580 | |
1581 | slab_early_init = 0; |
1582 | |
1583 | /* 4) Replace the bootstrap head arrays */ |
1584 | { |
1585 | struct array_cache *ptr; |
1586 | |
1587 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1588 | |
1589 | memcpy(ptr, cpu_cache_get(kmem_cache), |
1590 | sizeof(struct arraycache_init)); |
1591 | /* |
1592 | * Do not assume that spinlocks can be initialized via memcpy: |
1593 | */ |
1594 | spin_lock_init(&ptr->lock); |
1595 | |
1596 | kmem_cache->array[smp_processor_id()] = ptr; |
1597 | |
1598 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1599 | |
1600 | BUG_ON(cpu_cache_get(kmalloc_caches[INDEX_AC]) |
1601 | != &initarray_generic.cache); |
1602 | memcpy(ptr, cpu_cache_get(kmalloc_caches[INDEX_AC]), |
1603 | sizeof(struct arraycache_init)); |
1604 | /* |
1605 | * Do not assume that spinlocks can be initialized via memcpy: |
1606 | */ |
1607 | spin_lock_init(&ptr->lock); |
1608 | |
1609 | kmalloc_caches[INDEX_AC]->array[smp_processor_id()] = ptr; |
1610 | } |
1611 | /* 5) Replace the bootstrap kmem_cache_node */ |
1612 | { |
1613 | int nid; |
1614 | |
1615 | for_each_online_node(nid) { |
1616 | init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); |
1617 | |
1618 | init_list(kmalloc_caches[INDEX_AC], |
1619 | &init_kmem_cache_node[SIZE_AC + nid], nid); |
1620 | |
1621 | if (INDEX_AC != INDEX_NODE) { |
1622 | init_list(kmalloc_caches[INDEX_NODE], |
1623 | &init_kmem_cache_node[SIZE_NODE + nid], nid); |
1624 | } |
1625 | } |
1626 | } |
1627 | |
1628 | create_kmalloc_caches(ARCH_KMALLOC_FLAGS); |
1629 | } |
1630 | |
1631 | void __init kmem_cache_init_late(void) |
1632 | { |
1633 | struct kmem_cache *cachep; |
1634 | |
1635 | slab_state = UP; |
1636 | |
1637 | /* 6) resize the head arrays to their final sizes */ |
1638 | mutex_lock(&slab_mutex); |
1639 | list_for_each_entry(cachep, &slab_caches, list) |
1640 | if (enable_cpucache(cachep, GFP_NOWAIT)) |
1641 | BUG(); |
1642 | mutex_unlock(&slab_mutex); |
1643 | |
1644 | /* Annotate slab for lockdep -- annotate the malloc caches */ |
1645 | init_lock_keys(); |
1646 | |
1647 | /* Done! */ |
1648 | slab_state = FULL; |
1649 | |
1650 | /* |
1651 | * Register a cpu startup notifier callback that initializes |
1652 | * cpu_cache_get for all new cpus |
1653 | */ |
1654 | register_cpu_notifier(&cpucache_notifier); |
1655 | |
1656 | #ifdef CONFIG_NUMA |
1657 | /* |
1658 | * Register a memory hotplug callback that initializes and frees |
1659 | * node. |
1660 | */ |
1661 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
1662 | #endif |
1663 | |
1664 | /* |
1665 | * The reap timers are started later, with a module init call: That part |
1666 | * of the kernel is not yet operational. |
1667 | */ |
1668 | } |
1669 | |
1670 | static int __init cpucache_init(void) |
1671 | { |
1672 | int cpu; |
1673 | |
1674 | /* |
1675 | * Register the timers that return unneeded pages to the page allocator |
1676 | */ |
1677 | for_each_online_cpu(cpu) |
1678 | start_cpu_timer(cpu); |
1679 | |
1680 | /* Done! */ |
1681 | slab_state = FULL; |
1682 | return 0; |
1683 | } |
1684 | __initcall(cpucache_init); |
1685 | |
1686 | static noinline void |
1687 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) |
1688 | { |
1689 | struct kmem_cache_node *n; |
1690 | struct slab *slabp; |
1691 | unsigned long flags; |
1692 | int node; |
1693 | |
1694 | printk(KERN_WARNING |
1695 | "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
1696 | nodeid, gfpflags); |
1697 | printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", |
1698 | cachep->name, cachep->size, cachep->gfporder); |
1699 | |
1700 | for_each_online_node(node) { |
1701 | unsigned long active_objs = 0, num_objs = 0, free_objects = 0; |
1702 | unsigned long active_slabs = 0, num_slabs = 0; |
1703 | |
1704 | n = cachep->node[node]; |
1705 | if (!n) |
1706 | continue; |
1707 | |
1708 | spin_lock_irqsave(&n->list_lock, flags); |
1709 | list_for_each_entry(slabp, &n->slabs_full, list) { |
1710 | active_objs += cachep->num; |
1711 | active_slabs++; |
1712 | } |
1713 | list_for_each_entry(slabp, &n->slabs_partial, list) { |
1714 | active_objs += slabp->inuse; |
1715 | active_slabs++; |
1716 | } |
1717 | list_for_each_entry(slabp, &n->slabs_free, list) |
1718 | num_slabs++; |
1719 | |
1720 | free_objects += n->free_objects; |
1721 | spin_unlock_irqrestore(&n->list_lock, flags); |
1722 | |
1723 | num_slabs += active_slabs; |
1724 | num_objs = num_slabs * cachep->num; |
1725 | printk(KERN_WARNING |
1726 | " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", |
1727 | node, active_slabs, num_slabs, active_objs, num_objs, |
1728 | free_objects); |
1729 | } |
1730 | } |
1731 | |
1732 | /* |
1733 | * Interface to system's page allocator. No need to hold the cache-lock. |
1734 | * |
1735 | * If we requested dmaable memory, we will get it. Even if we |
1736 | * did not request dmaable memory, we might get it, but that |
1737 | * would be relatively rare and ignorable. |
1738 | */ |
1739 | static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
1740 | { |
1741 | struct page *page; |
1742 | int nr_pages; |
1743 | int i; |
1744 | |
1745 | #ifndef CONFIG_MMU |
1746 | /* |
1747 | * Nommu uses slab's for process anonymous memory allocations, and thus |
1748 | * requires __GFP_COMP to properly refcount higher order allocations |
1749 | */ |
1750 | flags |= __GFP_COMP; |
1751 | #endif |
1752 | |
1753 | flags |= cachep->allocflags; |
1754 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1755 | flags |= __GFP_RECLAIMABLE; |
1756 | |
1757 | page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); |
1758 | if (!page) { |
1759 | if (!(flags & __GFP_NOWARN) && printk_ratelimit()) |
1760 | slab_out_of_memory(cachep, flags, nodeid); |
1761 | return NULL; |
1762 | } |
1763 | |
1764 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ |
1765 | if (unlikely(page->pfmemalloc)) |
1766 | pfmemalloc_active = true; |
1767 | |
1768 | nr_pages = (1 << cachep->gfporder); |
1769 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1770 | add_zone_page_state(page_zone(page), |
1771 | NR_SLAB_RECLAIMABLE, nr_pages); |
1772 | else |
1773 | add_zone_page_state(page_zone(page), |
1774 | NR_SLAB_UNRECLAIMABLE, nr_pages); |
1775 | for (i = 0; i < nr_pages; i++) { |
1776 | __SetPageSlab(page + i); |
1777 | |
1778 | if (page->pfmemalloc) |
1779 | SetPageSlabPfmemalloc(page + i); |
1780 | } |
1781 | memcg_bind_pages(cachep, cachep->gfporder); |
1782 | |
1783 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { |
1784 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); |
1785 | |
1786 | if (cachep->ctor) |
1787 | kmemcheck_mark_uninitialized_pages(page, nr_pages); |
1788 | else |
1789 | kmemcheck_mark_unallocated_pages(page, nr_pages); |
1790 | } |
1791 | |
1792 | return page_address(page); |
1793 | } |
1794 | |
1795 | /* |
1796 | * Interface to system's page release. |
1797 | */ |
1798 | static void kmem_freepages(struct kmem_cache *cachep, void *addr) |
1799 | { |
1800 | unsigned long i = (1 << cachep->gfporder); |
1801 | struct page *page = virt_to_page(addr); |
1802 | const unsigned long nr_freed = i; |
1803 | |
1804 | kmemcheck_free_shadow(page, cachep->gfporder); |
1805 | |
1806 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1807 | sub_zone_page_state(page_zone(page), |
1808 | NR_SLAB_RECLAIMABLE, nr_freed); |
1809 | else |
1810 | sub_zone_page_state(page_zone(page), |
1811 | NR_SLAB_UNRECLAIMABLE, nr_freed); |
1812 | while (i--) { |
1813 | BUG_ON(!PageSlab(page)); |
1814 | __ClearPageSlabPfmemalloc(page); |
1815 | __ClearPageSlab(page); |
1816 | page++; |
1817 | } |
1818 | |
1819 | memcg_release_pages(cachep, cachep->gfporder); |
1820 | if (current->reclaim_state) |
1821 | current->reclaim_state->reclaimed_slab += nr_freed; |
1822 | free_memcg_kmem_pages((unsigned long)addr, cachep->gfporder); |
1823 | } |
1824 | |
1825 | static void kmem_rcu_free(struct rcu_head *head) |
1826 | { |
1827 | struct slab_rcu *slab_rcu = (struct slab_rcu *)head; |
1828 | struct kmem_cache *cachep = slab_rcu->cachep; |
1829 | |
1830 | kmem_freepages(cachep, slab_rcu->addr); |
1831 | if (OFF_SLAB(cachep)) |
1832 | kmem_cache_free(cachep->slabp_cache, slab_rcu); |
1833 | } |
1834 | |
1835 | #if DEBUG |
1836 | |
1837 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1838 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, |
1839 | unsigned long caller) |
1840 | { |
1841 | int size = cachep->object_size; |
1842 | |
1843 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; |
1844 | |
1845 | if (size < 5 * sizeof(unsigned long)) |
1846 | return; |
1847 | |
1848 | *addr++ = 0x12345678; |
1849 | *addr++ = caller; |
1850 | *addr++ = smp_processor_id(); |
1851 | size -= 3 * sizeof(unsigned long); |
1852 | { |
1853 | unsigned long *sptr = &caller; |
1854 | unsigned long svalue; |
1855 | |
1856 | while (!kstack_end(sptr)) { |
1857 | svalue = *sptr++; |
1858 | if (kernel_text_address(svalue)) { |
1859 | *addr++ = svalue; |
1860 | size -= sizeof(unsigned long); |
1861 | if (size <= sizeof(unsigned long)) |
1862 | break; |
1863 | } |
1864 | } |
1865 | |
1866 | } |
1867 | *addr++ = 0x87654321; |
1868 | } |
1869 | #endif |
1870 | |
1871 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) |
1872 | { |
1873 | int size = cachep->object_size; |
1874 | addr = &((char *)addr)[obj_offset(cachep)]; |
1875 | |
1876 | memset(addr, val, size); |
1877 | *(unsigned char *)(addr + size - 1) = POISON_END; |
1878 | } |
1879 | |
1880 | static void dump_line(char *data, int offset, int limit) |
1881 | { |
1882 | int i; |
1883 | unsigned char error = 0; |
1884 | int bad_count = 0; |
1885 | |
1886 | printk(KERN_ERR "%03x: ", offset); |
1887 | for (i = 0; i < limit; i++) { |
1888 | if (data[offset + i] != POISON_FREE) { |
1889 | error = data[offset + i]; |
1890 | bad_count++; |
1891 | } |
1892 | } |
1893 | print_hex_dump(KERN_CONT, "", 0, 16, 1, |
1894 | &data[offset], limit, 1); |
1895 | |
1896 | if (bad_count == 1) { |
1897 | error ^= POISON_FREE; |
1898 | if (!(error & (error - 1))) { |
1899 | printk(KERN_ERR "Single bit error detected. Probably " |
1900 | "bad RAM.\n"); |
1901 | #ifdef CONFIG_X86 |
1902 | printk(KERN_ERR "Run memtest86+ or a similar memory " |
1903 | "test tool.\n"); |
1904 | #else |
1905 | printk(KERN_ERR "Run a memory test tool.\n"); |
1906 | #endif |
1907 | } |
1908 | } |
1909 | } |
1910 | #endif |
1911 | |
1912 | #if DEBUG |
1913 | |
1914 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) |
1915 | { |
1916 | int i, size; |
1917 | char *realobj; |
1918 | |
1919 | if (cachep->flags & SLAB_RED_ZONE) { |
1920 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", |
1921 | *dbg_redzone1(cachep, objp), |
1922 | *dbg_redzone2(cachep, objp)); |
1923 | } |
1924 | |
1925 | if (cachep->flags & SLAB_STORE_USER) { |
1926 | printk(KERN_ERR "Last user: [<%p>](%pSR)\n", |
1927 | *dbg_userword(cachep, objp), |
1928 | *dbg_userword(cachep, objp)); |
1929 | } |
1930 | realobj = (char *)objp + obj_offset(cachep); |
1931 | size = cachep->object_size; |
1932 | for (i = 0; i < size && lines; i += 16, lines--) { |
1933 | int limit; |
1934 | limit = 16; |
1935 | if (i + limit > size) |
1936 | limit = size - i; |
1937 | dump_line(realobj, i, limit); |
1938 | } |
1939 | } |
1940 | |
1941 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) |
1942 | { |
1943 | char *realobj; |
1944 | int size, i; |
1945 | int lines = 0; |
1946 | |
1947 | realobj = (char *)objp + obj_offset(cachep); |
1948 | size = cachep->object_size; |
1949 | |
1950 | for (i = 0; i < size; i++) { |
1951 | char exp = POISON_FREE; |
1952 | if (i == size - 1) |
1953 | exp = POISON_END; |
1954 | if (realobj[i] != exp) { |
1955 | int limit; |
1956 | /* Mismatch ! */ |
1957 | /* Print header */ |
1958 | if (lines == 0) { |
1959 | printk(KERN_ERR |
1960 | "Slab corruption (%s): %s start=%p, len=%d\n", |
1961 | print_tainted(), cachep->name, realobj, size); |
1962 | print_objinfo(cachep, objp, 0); |
1963 | } |
1964 | /* Hexdump the affected line */ |
1965 | i = (i / 16) * 16; |
1966 | limit = 16; |
1967 | if (i + limit > size) |
1968 | limit = size - i; |
1969 | dump_line(realobj, i, limit); |
1970 | i += 16; |
1971 | lines++; |
1972 | /* Limit to 5 lines */ |
1973 | if (lines > 5) |
1974 | break; |
1975 | } |
1976 | } |
1977 | if (lines != 0) { |
1978 | /* Print some data about the neighboring objects, if they |
1979 | * exist: |
1980 | */ |
1981 | struct slab *slabp = virt_to_slab(objp); |
1982 | unsigned int objnr; |
1983 | |
1984 | objnr = obj_to_index(cachep, slabp, objp); |
1985 | if (objnr) { |
1986 | objp = index_to_obj(cachep, slabp, objnr - 1); |
1987 | realobj = (char *)objp + obj_offset(cachep); |
1988 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
1989 | realobj, size); |
1990 | print_objinfo(cachep, objp, 2); |
1991 | } |
1992 | if (objnr + 1 < cachep->num) { |
1993 | objp = index_to_obj(cachep, slabp, objnr + 1); |
1994 | realobj = (char *)objp + obj_offset(cachep); |
1995 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
1996 | realobj, size); |
1997 | print_objinfo(cachep, objp, 2); |
1998 | } |
1999 | } |
2000 | } |
2001 | #endif |
2002 | |
2003 | #if DEBUG |
2004 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) |
2005 | { |
2006 | int i; |
2007 | for (i = 0; i < cachep->num; i++) { |
2008 | void *objp = index_to_obj(cachep, slabp, i); |
2009 | |
2010 | if (cachep->flags & SLAB_POISON) { |
2011 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2012 | if (cachep->size % PAGE_SIZE == 0 && |
2013 | OFF_SLAB(cachep)) |
2014 | kernel_map_pages(virt_to_page(objp), |
2015 | cachep->size / PAGE_SIZE, 1); |
2016 | else |
2017 | check_poison_obj(cachep, objp); |
2018 | #else |
2019 | check_poison_obj(cachep, objp); |
2020 | #endif |
2021 | } |
2022 | if (cachep->flags & SLAB_RED_ZONE) { |
2023 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2024 | slab_error(cachep, "start of a freed object " |
2025 | "was overwritten"); |
2026 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2027 | slab_error(cachep, "end of a freed object " |
2028 | "was overwritten"); |
2029 | } |
2030 | } |
2031 | } |
2032 | #else |
2033 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) |
2034 | { |
2035 | } |
2036 | #endif |
2037 | |
2038 | /** |
2039 | * slab_destroy - destroy and release all objects in a slab |
2040 | * @cachep: cache pointer being destroyed |
2041 | * @slabp: slab pointer being destroyed |
2042 | * |
2043 | * Destroy all the objs in a slab, and release the mem back to the system. |
2044 | * Before calling the slab must have been unlinked from the cache. The |
2045 | * cache-lock is not held/needed. |
2046 | */ |
2047 | static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) |
2048 | { |
2049 | void *addr = slabp->s_mem - slabp->colouroff; |
2050 | |
2051 | slab_destroy_debugcheck(cachep, slabp); |
2052 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { |
2053 | struct slab_rcu *slab_rcu; |
2054 | |
2055 | slab_rcu = (struct slab_rcu *)slabp; |
2056 | slab_rcu->cachep = cachep; |
2057 | slab_rcu->addr = addr; |
2058 | call_rcu(&slab_rcu->head, kmem_rcu_free); |
2059 | } else { |
2060 | kmem_freepages(cachep, addr); |
2061 | if (OFF_SLAB(cachep)) |
2062 | kmem_cache_free(cachep->slabp_cache, slabp); |
2063 | } |
2064 | } |
2065 | |
2066 | /** |
2067 | * calculate_slab_order - calculate size (page order) of slabs |
2068 | * @cachep: pointer to the cache that is being created |
2069 | * @size: size of objects to be created in this cache. |
2070 | * @align: required alignment for the objects. |
2071 | * @flags: slab allocation flags |
2072 | * |
2073 | * Also calculates the number of objects per slab. |
2074 | * |
2075 | * This could be made much more intelligent. For now, try to avoid using |
2076 | * high order pages for slabs. When the gfp() functions are more friendly |
2077 | * towards high-order requests, this should be changed. |
2078 | */ |
2079 | static size_t calculate_slab_order(struct kmem_cache *cachep, |
2080 | size_t size, size_t align, unsigned long flags) |
2081 | { |
2082 | unsigned long offslab_limit; |
2083 | size_t left_over = 0; |
2084 | int gfporder; |
2085 | |
2086 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { |
2087 | unsigned int num; |
2088 | size_t remainder; |
2089 | |
2090 | cache_estimate(gfporder, size, align, flags, &remainder, &num); |
2091 | if (!num) |
2092 | continue; |
2093 | |
2094 | if (flags & CFLGS_OFF_SLAB) { |
2095 | /* |
2096 | * Max number of objs-per-slab for caches which |
2097 | * use off-slab slabs. Needed to avoid a possible |
2098 | * looping condition in cache_grow(). |
2099 | */ |
2100 | offslab_limit = size - sizeof(struct slab); |
2101 | offslab_limit /= sizeof(kmem_bufctl_t); |
2102 | |
2103 | if (num > offslab_limit) |
2104 | break; |
2105 | } |
2106 | |
2107 | /* Found something acceptable - save it away */ |
2108 | cachep->num = num; |
2109 | cachep->gfporder = gfporder; |
2110 | left_over = remainder; |
2111 | |
2112 | /* |
2113 | * A VFS-reclaimable slab tends to have most allocations |
2114 | * as GFP_NOFS and we really don't want to have to be allocating |
2115 | * higher-order pages when we are unable to shrink dcache. |
2116 | */ |
2117 | if (flags & SLAB_RECLAIM_ACCOUNT) |
2118 | break; |
2119 | |
2120 | /* |
2121 | * Large number of objects is good, but very large slabs are |
2122 | * currently bad for the gfp()s. |
2123 | */ |
2124 | if (gfporder >= slab_max_order) |
2125 | break; |
2126 | |
2127 | /* |
2128 | * Acceptable internal fragmentation? |
2129 | */ |
2130 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) |
2131 | break; |
2132 | } |
2133 | return left_over; |
2134 | } |
2135 | |
2136 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) |
2137 | { |
2138 | if (slab_state >= FULL) |
2139 | return enable_cpucache(cachep, gfp); |
2140 | |
2141 | if (slab_state == DOWN) { |
2142 | /* |
2143 | * Note: Creation of first cache (kmem_cache). |
2144 | * The setup_node is taken care |
2145 | * of by the caller of __kmem_cache_create |
2146 | */ |
2147 | cachep->array[smp_processor_id()] = &initarray_generic.cache; |
2148 | slab_state = PARTIAL; |
2149 | } else if (slab_state == PARTIAL) { |
2150 | /* |
2151 | * Note: the second kmem_cache_create must create the cache |
2152 | * that's used by kmalloc(24), otherwise the creation of |
2153 | * further caches will BUG(). |
2154 | */ |
2155 | cachep->array[smp_processor_id()] = &initarray_generic.cache; |
2156 | |
2157 | /* |
2158 | * If the cache that's used by kmalloc(sizeof(kmem_cache_node)) is |
2159 | * the second cache, then we need to set up all its node/, |
2160 | * otherwise the creation of further caches will BUG(). |
2161 | */ |
2162 | set_up_node(cachep, SIZE_AC); |
2163 | if (INDEX_AC == INDEX_NODE) |
2164 | slab_state = PARTIAL_NODE; |
2165 | else |
2166 | slab_state = PARTIAL_ARRAYCACHE; |
2167 | } else { |
2168 | /* Remaining boot caches */ |
2169 | cachep->array[smp_processor_id()] = |
2170 | kmalloc(sizeof(struct arraycache_init), gfp); |
2171 | |
2172 | if (slab_state == PARTIAL_ARRAYCACHE) { |
2173 | set_up_node(cachep, SIZE_NODE); |
2174 | slab_state = PARTIAL_NODE; |
2175 | } else { |
2176 | int node; |
2177 | for_each_online_node(node) { |
2178 | cachep->node[node] = |
2179 | kmalloc_node(sizeof(struct kmem_cache_node), |
2180 | gfp, node); |
2181 | BUG_ON(!cachep->node[node]); |
2182 | kmem_cache_node_init(cachep->node[node]); |
2183 | } |
2184 | } |
2185 | } |
2186 | cachep->node[numa_mem_id()]->next_reap = |
2187 | jiffies + REAPTIMEOUT_LIST3 + |
2188 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
2189 | |
2190 | cpu_cache_get(cachep)->avail = 0; |
2191 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
2192 | cpu_cache_get(cachep)->batchcount = 1; |
2193 | cpu_cache_get(cachep)->touched = 0; |
2194 | cachep->batchcount = 1; |
2195 | cachep->limit = BOOT_CPUCACHE_ENTRIES; |
2196 | return 0; |
2197 | } |
2198 | |
2199 | /** |
2200 | * __kmem_cache_create - Create a cache. |
2201 | * @cachep: cache management descriptor |
2202 | * @flags: SLAB flags |
2203 | * |
2204 | * Returns a ptr to the cache on success, NULL on failure. |
2205 | * Cannot be called within a int, but can be interrupted. |
2206 | * The @ctor is run when new pages are allocated by the cache. |
2207 | * |
2208 | * The flags are |
2209 | * |
2210 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
2211 | * to catch references to uninitialised memory. |
2212 | * |
2213 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
2214 | * for buffer overruns. |
2215 | * |
2216 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
2217 | * cacheline. This can be beneficial if you're counting cycles as closely |
2218 | * as davem. |
2219 | */ |
2220 | int |
2221 | __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) |
2222 | { |
2223 | size_t left_over, slab_size, ralign; |
2224 | gfp_t gfp; |
2225 | int err; |
2226 | size_t size = cachep->size; |
2227 | |
2228 | #if DEBUG |
2229 | #if FORCED_DEBUG |
2230 | /* |
2231 | * Enable redzoning and last user accounting, except for caches with |
2232 | * large objects, if the increased size would increase the object size |
2233 | * above the next power of two: caches with object sizes just above a |
2234 | * power of two have a significant amount of internal fragmentation. |
2235 | */ |
2236 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + |
2237 | 2 * sizeof(unsigned long long))) |
2238 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; |
2239 | if (!(flags & SLAB_DESTROY_BY_RCU)) |
2240 | flags |= SLAB_POISON; |
2241 | #endif |
2242 | if (flags & SLAB_DESTROY_BY_RCU) |
2243 | BUG_ON(flags & SLAB_POISON); |
2244 | #endif |
2245 | |
2246 | /* |
2247 | * Check that size is in terms of words. This is needed to avoid |
2248 | * unaligned accesses for some archs when redzoning is used, and makes |
2249 | * sure any on-slab bufctl's are also correctly aligned. |
2250 | */ |
2251 | if (size & (BYTES_PER_WORD - 1)) { |
2252 | size += (BYTES_PER_WORD - 1); |
2253 | size &= ~(BYTES_PER_WORD - 1); |
2254 | } |
2255 | |
2256 | /* |
2257 | * Redzoning and user store require word alignment or possibly larger. |
2258 | * Note this will be overridden by architecture or caller mandated |
2259 | * alignment if either is greater than BYTES_PER_WORD. |
2260 | */ |
2261 | if (flags & SLAB_STORE_USER) |
2262 | ralign = BYTES_PER_WORD; |
2263 | |
2264 | if (flags & SLAB_RED_ZONE) { |
2265 | ralign = REDZONE_ALIGN; |
2266 | /* If redzoning, ensure that the second redzone is suitably |
2267 | * aligned, by adjusting the object size accordingly. */ |
2268 | size += REDZONE_ALIGN - 1; |
2269 | size &= ~(REDZONE_ALIGN - 1); |
2270 | } |
2271 | |
2272 | /* 3) caller mandated alignment */ |
2273 | if (ralign < cachep->align) { |
2274 | ralign = cachep->align; |
2275 | } |
2276 | /* disable debug if necessary */ |
2277 | if (ralign > __alignof__(unsigned long long)) |
2278 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2279 | /* |
2280 | * 4) Store it. |
2281 | */ |
2282 | cachep->align = ralign; |
2283 | |
2284 | if (slab_is_available()) |
2285 | gfp = GFP_KERNEL; |
2286 | else |
2287 | gfp = GFP_NOWAIT; |
2288 | |
2289 | setup_node_pointer(cachep); |
2290 | #if DEBUG |
2291 | |
2292 | /* |
2293 | * Both debugging options require word-alignment which is calculated |
2294 | * into align above. |
2295 | */ |
2296 | if (flags & SLAB_RED_ZONE) { |
2297 | /* add space for red zone words */ |
2298 | cachep->obj_offset += sizeof(unsigned long long); |
2299 | size += 2 * sizeof(unsigned long long); |
2300 | } |
2301 | if (flags & SLAB_STORE_USER) { |
2302 | /* user store requires one word storage behind the end of |
2303 | * the real object. But if the second red zone needs to be |
2304 | * aligned to 64 bits, we must allow that much space. |
2305 | */ |
2306 | if (flags & SLAB_RED_ZONE) |
2307 | size += REDZONE_ALIGN; |
2308 | else |
2309 | size += BYTES_PER_WORD; |
2310 | } |
2311 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
2312 | if (size >= kmalloc_size(INDEX_NODE + 1) |
2313 | && cachep->object_size > cache_line_size() |
2314 | && ALIGN(size, cachep->align) < PAGE_SIZE) { |
2315 | cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align); |
2316 | size = PAGE_SIZE; |
2317 | } |
2318 | #endif |
2319 | #endif |
2320 | |
2321 | /* |
2322 | * Determine if the slab management is 'on' or 'off' slab. |
2323 | * (bootstrapping cannot cope with offslab caches so don't do |
2324 | * it too early on. Always use on-slab management when |
2325 | * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) |
2326 | */ |
2327 | if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && |
2328 | !(flags & SLAB_NOLEAKTRACE)) |
2329 | /* |
2330 | * Size is large, assume best to place the slab management obj |
2331 | * off-slab (should allow better packing of objs). |
2332 | */ |
2333 | flags |= CFLGS_OFF_SLAB; |
2334 | |
2335 | size = ALIGN(size, cachep->align); |
2336 | |
2337 | left_over = calculate_slab_order(cachep, size, cachep->align, flags); |
2338 | |
2339 | if (!cachep->num) |
2340 | return -E2BIG; |
2341 | |
2342 | slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) |
2343 | + sizeof(struct slab), cachep->align); |
2344 | |
2345 | /* |
2346 | * If the slab has been placed off-slab, and we have enough space then |
2347 | * move it on-slab. This is at the expense of any extra colouring. |
2348 | */ |
2349 | if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { |
2350 | flags &= ~CFLGS_OFF_SLAB; |
2351 | left_over -= slab_size; |
2352 | } |
2353 | |
2354 | if (flags & CFLGS_OFF_SLAB) { |
2355 | /* really off slab. No need for manual alignment */ |
2356 | slab_size = |
2357 | cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); |
2358 | |
2359 | #ifdef CONFIG_PAGE_POISONING |
2360 | /* If we're going to use the generic kernel_map_pages() |
2361 | * poisoning, then it's going to smash the contents of |
2362 | * the redzone and userword anyhow, so switch them off. |
2363 | */ |
2364 | if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) |
2365 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2366 | #endif |
2367 | } |
2368 | |
2369 | cachep->colour_off = cache_line_size(); |
2370 | /* Offset must be a multiple of the alignment. */ |
2371 | if (cachep->colour_off < cachep->align) |
2372 | cachep->colour_off = cachep->align; |
2373 | cachep->colour = left_over / cachep->colour_off; |
2374 | cachep->slab_size = slab_size; |
2375 | cachep->flags = flags; |
2376 | cachep->allocflags = 0; |
2377 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) |
2378 | cachep->allocflags |= GFP_DMA; |
2379 | cachep->size = size; |
2380 | cachep->reciprocal_buffer_size = reciprocal_value(size); |
2381 | |
2382 | if (flags & CFLGS_OFF_SLAB) { |
2383 | cachep->slabp_cache = kmalloc_slab(slab_size, 0u); |
2384 | /* |
2385 | * This is a possibility for one of the malloc_sizes caches. |
2386 | * But since we go off slab only for object size greater than |
2387 | * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, |
2388 | * this should not happen at all. |
2389 | * But leave a BUG_ON for some lucky dude. |
2390 | */ |
2391 | BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); |
2392 | } |
2393 | |
2394 | err = setup_cpu_cache(cachep, gfp); |
2395 | if (err) { |
2396 | __kmem_cache_shutdown(cachep); |
2397 | return err; |
2398 | } |
2399 | |
2400 | if (flags & SLAB_DEBUG_OBJECTS) { |
2401 | /* |
2402 | * Would deadlock through slab_destroy()->call_rcu()-> |
2403 | * debug_object_activate()->kmem_cache_alloc(). |
2404 | */ |
2405 | WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU); |
2406 | |
2407 | slab_set_debugobj_lock_classes(cachep); |
2408 | } else if (!OFF_SLAB(cachep) && !(flags & SLAB_DESTROY_BY_RCU)) |
2409 | on_slab_lock_classes(cachep); |
2410 | |
2411 | return 0; |
2412 | } |
2413 | |
2414 | #if DEBUG |
2415 | static void check_irq_off(void) |
2416 | { |
2417 | BUG_ON(!irqs_disabled()); |
2418 | } |
2419 | |
2420 | static void check_irq_on(void) |
2421 | { |
2422 | BUG_ON(irqs_disabled()); |
2423 | } |
2424 | |
2425 | static void check_spinlock_acquired(struct kmem_cache *cachep) |
2426 | { |
2427 | #ifdef CONFIG_SMP |
2428 | check_irq_off(); |
2429 | assert_spin_locked(&cachep->node[numa_mem_id()]->list_lock); |
2430 | #endif |
2431 | } |
2432 | |
2433 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) |
2434 | { |
2435 | #ifdef CONFIG_SMP |
2436 | check_irq_off(); |
2437 | assert_spin_locked(&cachep->node[node]->list_lock); |
2438 | #endif |
2439 | } |
2440 | |
2441 | #else |
2442 | #define check_irq_off() do { } while(0) |
2443 | #define check_irq_on() do { } while(0) |
2444 | #define check_spinlock_acquired(x) do { } while(0) |
2445 | #define check_spinlock_acquired_node(x, y) do { } while(0) |
2446 | #endif |
2447 | |
2448 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
2449 | struct array_cache *ac, |
2450 | int force, int node); |
2451 | |
2452 | static void do_drain(void *arg) |
2453 | { |
2454 | struct kmem_cache *cachep = arg; |
2455 | struct array_cache *ac; |
2456 | int node = numa_mem_id(); |
2457 | |
2458 | check_irq_off(); |
2459 | ac = cpu_cache_get(cachep); |
2460 | spin_lock(&cachep->node[node]->list_lock); |
2461 | free_block(cachep, ac->entry, ac->avail, node); |
2462 | spin_unlock(&cachep->node[node]->list_lock); |
2463 | ac->avail = 0; |
2464 | } |
2465 | |
2466 | static void drain_cpu_caches(struct kmem_cache *cachep) |
2467 | { |
2468 | struct kmem_cache_node *n; |
2469 | int node; |
2470 | |
2471 | on_each_cpu(do_drain, cachep, 1); |
2472 | check_irq_on(); |
2473 | for_each_online_node(node) { |
2474 | n = cachep->node[node]; |
2475 | if (n && n->alien) |
2476 | drain_alien_cache(cachep, n->alien); |
2477 | } |
2478 | |
2479 | for_each_online_node(node) { |
2480 | n = cachep->node[node]; |
2481 | if (n) |
2482 | drain_array(cachep, n, n->shared, 1, node); |
2483 | } |
2484 | } |
2485 | |
2486 | /* |
2487 | * Remove slabs from the list of free slabs. |
2488 | * Specify the number of slabs to drain in tofree. |
2489 | * |
2490 | * Returns the actual number of slabs released. |
2491 | */ |
2492 | static int drain_freelist(struct kmem_cache *cache, |
2493 | struct kmem_cache_node *n, int tofree) |
2494 | { |
2495 | struct list_head *p; |
2496 | int nr_freed; |
2497 | struct slab *slabp; |
2498 | |
2499 | nr_freed = 0; |
2500 | while (nr_freed < tofree && !list_empty(&n->slabs_free)) { |
2501 | |
2502 | spin_lock_irq(&n->list_lock); |
2503 | p = n->slabs_free.prev; |
2504 | if (p == &n->slabs_free) { |
2505 | spin_unlock_irq(&n->list_lock); |
2506 | goto out; |
2507 | } |
2508 | |
2509 | slabp = list_entry(p, struct slab, list); |
2510 | #if DEBUG |
2511 | BUG_ON(slabp->inuse); |
2512 | #endif |
2513 | list_del(&slabp->list); |
2514 | /* |
2515 | * Safe to drop the lock. The slab is no longer linked |
2516 | * to the cache. |
2517 | */ |
2518 | n->free_objects -= cache->num; |
2519 | spin_unlock_irq(&n->list_lock); |
2520 | slab_destroy(cache, slabp); |
2521 | nr_freed++; |
2522 | } |
2523 | out: |
2524 | return nr_freed; |
2525 | } |
2526 | |
2527 | /* Called with slab_mutex held to protect against cpu hotplug */ |
2528 | static int __cache_shrink(struct kmem_cache *cachep) |
2529 | { |
2530 | int ret = 0, i = 0; |
2531 | struct kmem_cache_node *n; |
2532 | |
2533 | drain_cpu_caches(cachep); |
2534 | |
2535 | check_irq_on(); |
2536 | for_each_online_node(i) { |
2537 | n = cachep->node[i]; |
2538 | if (!n) |
2539 | continue; |
2540 | |
2541 | drain_freelist(cachep, n, slabs_tofree(cachep, n)); |
2542 | |
2543 | ret += !list_empty(&n->slabs_full) || |
2544 | !list_empty(&n->slabs_partial); |
2545 | } |
2546 | return (ret ? 1 : 0); |
2547 | } |
2548 | |
2549 | /** |
2550 | * kmem_cache_shrink - Shrink a cache. |
2551 | * @cachep: The cache to shrink. |
2552 | * |
2553 | * Releases as many slabs as possible for a cache. |
2554 | * To help debugging, a zero exit status indicates all slabs were released. |
2555 | */ |
2556 | int kmem_cache_shrink(struct kmem_cache *cachep) |
2557 | { |
2558 | int ret; |
2559 | BUG_ON(!cachep || in_interrupt()); |
2560 | |
2561 | get_online_cpus(); |
2562 | mutex_lock(&slab_mutex); |
2563 | ret = __cache_shrink(cachep); |
2564 | mutex_unlock(&slab_mutex); |
2565 | put_online_cpus(); |
2566 | return ret; |
2567 | } |
2568 | EXPORT_SYMBOL(kmem_cache_shrink); |
2569 | |
2570 | int __kmem_cache_shutdown(struct kmem_cache *cachep) |
2571 | { |
2572 | int i; |
2573 | struct kmem_cache_node *n; |
2574 | int rc = __cache_shrink(cachep); |
2575 | |
2576 | if (rc) |
2577 | return rc; |
2578 | |
2579 | for_each_online_cpu(i) |
2580 | kfree(cachep->array[i]); |
2581 | |
2582 | /* NUMA: free the node structures */ |
2583 | for_each_online_node(i) { |
2584 | n = cachep->node[i]; |
2585 | if (n) { |
2586 | kfree(n->shared); |
2587 | free_alien_cache(n->alien); |
2588 | kfree(n); |
2589 | } |
2590 | } |
2591 | return 0; |
2592 | } |
2593 | |
2594 | /* |
2595 | * Get the memory for a slab management obj. |
2596 | * For a slab cache when the slab descriptor is off-slab, slab descriptors |
2597 | * always come from malloc_sizes caches. The slab descriptor cannot |
2598 | * come from the same cache which is getting created because, |
2599 | * when we are searching for an appropriate cache for these |
2600 | * descriptors in kmem_cache_create, we search through the malloc_sizes array. |
2601 | * If we are creating a malloc_sizes cache here it would not be visible to |
2602 | * kmem_find_general_cachep till the initialization is complete. |
2603 | * Hence we cannot have slabp_cache same as the original cache. |
2604 | */ |
2605 | static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, |
2606 | int colour_off, gfp_t local_flags, |
2607 | int nodeid) |
2608 | { |
2609 | struct slab *slabp; |
2610 | |
2611 | if (OFF_SLAB(cachep)) { |
2612 | /* Slab management obj is off-slab. */ |
2613 | slabp = kmem_cache_alloc_node(cachep->slabp_cache, |
2614 | local_flags, nodeid); |
2615 | /* |
2616 | * If the first object in the slab is leaked (it's allocated |
2617 | * but no one has a reference to it), we want to make sure |
2618 | * kmemleak does not treat the ->s_mem pointer as a reference |
2619 | * to the object. Otherwise we will not report the leak. |
2620 | */ |
2621 | kmemleak_scan_area(&slabp->list, sizeof(struct list_head), |
2622 | local_flags); |
2623 | if (!slabp) |
2624 | return NULL; |
2625 | } else { |
2626 | slabp = objp + colour_off; |
2627 | colour_off += cachep->slab_size; |
2628 | } |
2629 | slabp->inuse = 0; |
2630 | slabp->colouroff = colour_off; |
2631 | slabp->s_mem = objp + colour_off; |
2632 | slabp->nodeid = nodeid; |
2633 | slabp->free = 0; |
2634 | return slabp; |
2635 | } |
2636 | |
2637 | static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) |
2638 | { |
2639 | return (kmem_bufctl_t *) (slabp + 1); |
2640 | } |
2641 | |
2642 | static void cache_init_objs(struct kmem_cache *cachep, |
2643 | struct slab *slabp) |
2644 | { |
2645 | int i; |
2646 | |
2647 | for (i = 0; i < cachep->num; i++) { |
2648 | void *objp = index_to_obj(cachep, slabp, i); |
2649 | #if DEBUG |
2650 | /* need to poison the objs? */ |
2651 | if (cachep->flags & SLAB_POISON) |
2652 | poison_obj(cachep, objp, POISON_FREE); |
2653 | if (cachep->flags & SLAB_STORE_USER) |
2654 | *dbg_userword(cachep, objp) = NULL; |
2655 | |
2656 | if (cachep->flags & SLAB_RED_ZONE) { |
2657 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2658 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2659 | } |
2660 | /* |
2661 | * Constructors are not allowed to allocate memory from the same |
2662 | * cache which they are a constructor for. Otherwise, deadlock. |
2663 | * They must also be threaded. |
2664 | */ |
2665 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) |
2666 | cachep->ctor(objp + obj_offset(cachep)); |
2667 | |
2668 | if (cachep->flags & SLAB_RED_ZONE) { |
2669 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2670 | slab_error(cachep, "constructor overwrote the" |
2671 | " end of an object"); |
2672 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2673 | slab_error(cachep, "constructor overwrote the" |
2674 | " start of an object"); |
2675 | } |
2676 | if ((cachep->size % PAGE_SIZE) == 0 && |
2677 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
2678 | kernel_map_pages(virt_to_page(objp), |
2679 | cachep->size / PAGE_SIZE, 0); |
2680 | #else |
2681 | if (cachep->ctor) |
2682 | cachep->ctor(objp); |
2683 | #endif |
2684 | slab_bufctl(slabp)[i] = i + 1; |
2685 | } |
2686 | slab_bufctl(slabp)[i - 1] = BUFCTL_END; |
2687 | } |
2688 | |
2689 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) |
2690 | { |
2691 | if (CONFIG_ZONE_DMA_FLAG) { |
2692 | if (flags & GFP_DMA) |
2693 | BUG_ON(!(cachep->allocflags & GFP_DMA)); |
2694 | else |
2695 | BUG_ON(cachep->allocflags & GFP_DMA); |
2696 | } |
2697 | } |
2698 | |
2699 | static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, |
2700 | int nodeid) |
2701 | { |
2702 | void *objp = index_to_obj(cachep, slabp, slabp->free); |
2703 | kmem_bufctl_t next; |
2704 | |
2705 | slabp->inuse++; |
2706 | next = slab_bufctl(slabp)[slabp->free]; |
2707 | #if DEBUG |
2708 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; |
2709 | WARN_ON(slabp->nodeid != nodeid); |
2710 | #endif |
2711 | slabp->free = next; |
2712 | |
2713 | return objp; |
2714 | } |
2715 | |
2716 | static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, |
2717 | void *objp, int nodeid) |
2718 | { |
2719 | unsigned int objnr = obj_to_index(cachep, slabp, objp); |
2720 | |
2721 | #if DEBUG |
2722 | /* Verify that the slab belongs to the intended node */ |
2723 | WARN_ON(slabp->nodeid != nodeid); |
2724 | |
2725 | if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { |
2726 | printk(KERN_ERR "slab: double free detected in cache " |
2727 | "'%s', objp %p\n", cachep->name, objp); |
2728 | BUG(); |
2729 | } |
2730 | #endif |
2731 | slab_bufctl(slabp)[objnr] = slabp->free; |
2732 | slabp->free = objnr; |
2733 | slabp->inuse--; |
2734 | } |
2735 | |
2736 | /* |
2737 | * Map pages beginning at addr to the given cache and slab. This is required |
2738 | * for the slab allocator to be able to lookup the cache and slab of a |
2739 | * virtual address for kfree, ksize, and slab debugging. |
2740 | */ |
2741 | static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, |
2742 | void *addr) |
2743 | { |
2744 | int nr_pages; |
2745 | struct page *page; |
2746 | |
2747 | page = virt_to_page(addr); |
2748 | |
2749 | nr_pages = 1; |
2750 | if (likely(!PageCompound(page))) |
2751 | nr_pages <<= cache->gfporder; |
2752 | |
2753 | do { |
2754 | page->slab_cache = cache; |
2755 | page->slab_page = slab; |
2756 | page++; |
2757 | } while (--nr_pages); |
2758 | } |
2759 | |
2760 | /* |
2761 | * Grow (by 1) the number of slabs within a cache. This is called by |
2762 | * kmem_cache_alloc() when there are no active objs left in a cache. |
2763 | */ |
2764 | static int cache_grow(struct kmem_cache *cachep, |
2765 | gfp_t flags, int nodeid, void *objp) |
2766 | { |
2767 | struct slab *slabp; |
2768 | size_t offset; |
2769 | gfp_t local_flags; |
2770 | struct kmem_cache_node *n; |
2771 | |
2772 | /* |
2773 | * Be lazy and only check for valid flags here, keeping it out of the |
2774 | * critical path in kmem_cache_alloc(). |
2775 | */ |
2776 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
2777 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
2778 | |
2779 | /* Take the node list lock to change the colour_next on this node */ |
2780 | check_irq_off(); |
2781 | n = cachep->node[nodeid]; |
2782 | spin_lock(&n->list_lock); |
2783 | |
2784 | /* Get colour for the slab, and cal the next value. */ |
2785 | offset = n->colour_next; |
2786 | n->colour_next++; |
2787 | if (n->colour_next >= cachep->colour) |
2788 | n->colour_next = 0; |
2789 | spin_unlock(&n->list_lock); |
2790 | |
2791 | offset *= cachep->colour_off; |
2792 | |
2793 | if (local_flags & __GFP_WAIT) |
2794 | local_irq_enable(); |
2795 | |
2796 | /* |
2797 | * The test for missing atomic flag is performed here, rather than |
2798 | * the more obvious place, simply to reduce the critical path length |
2799 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they |
2800 | * will eventually be caught here (where it matters). |
2801 | */ |
2802 | kmem_flagcheck(cachep, flags); |
2803 | |
2804 | /* |
2805 | * Get mem for the objs. Attempt to allocate a physical page from |
2806 | * 'nodeid'. |
2807 | */ |
2808 | if (!objp) |
2809 | objp = kmem_getpages(cachep, local_flags, nodeid); |
2810 | if (!objp) |
2811 | goto failed; |
2812 | |
2813 | /* Get slab management. */ |
2814 | slabp = alloc_slabmgmt(cachep, objp, offset, |
2815 | local_flags & ~GFP_CONSTRAINT_MASK, nodeid); |
2816 | if (!slabp) |
2817 | goto opps1; |
2818 | |
2819 | slab_map_pages(cachep, slabp, objp); |
2820 | |
2821 | cache_init_objs(cachep, slabp); |
2822 | |
2823 | if (local_flags & __GFP_WAIT) |
2824 | local_irq_disable(); |
2825 | check_irq_off(); |
2826 | spin_lock(&n->list_lock); |
2827 | |
2828 | /* Make slab active. */ |
2829 | list_add_tail(&slabp->list, &(n->slabs_free)); |
2830 | STATS_INC_GROWN(cachep); |
2831 | n->free_objects += cachep->num; |
2832 | spin_unlock(&n->list_lock); |
2833 | return 1; |
2834 | opps1: |
2835 | kmem_freepages(cachep, objp); |
2836 | failed: |
2837 | if (local_flags & __GFP_WAIT) |
2838 | local_irq_disable(); |
2839 | return 0; |
2840 | } |
2841 | |
2842 | #if DEBUG |
2843 | |
2844 | /* |
2845 | * Perform extra freeing checks: |
2846 | * - detect bad pointers. |
2847 | * - POISON/RED_ZONE checking |
2848 | */ |
2849 | static void kfree_debugcheck(const void *objp) |
2850 | { |
2851 | if (!virt_addr_valid(objp)) { |
2852 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
2853 | (unsigned long)objp); |
2854 | BUG(); |
2855 | } |
2856 | } |
2857 | |
2858 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) |
2859 | { |
2860 | unsigned long long redzone1, redzone2; |
2861 | |
2862 | redzone1 = *dbg_redzone1(cache, obj); |
2863 | redzone2 = *dbg_redzone2(cache, obj); |
2864 | |
2865 | /* |
2866 | * Redzone is ok. |
2867 | */ |
2868 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) |
2869 | return; |
2870 | |
2871 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) |
2872 | slab_error(cache, "double free detected"); |
2873 | else |
2874 | slab_error(cache, "memory outside object was overwritten"); |
2875 | |
2876 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", |
2877 | obj, redzone1, redzone2); |
2878 | } |
2879 | |
2880 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, |
2881 | unsigned long caller) |
2882 | { |
2883 | struct page *page; |
2884 | unsigned int objnr; |
2885 | struct slab *slabp; |
2886 | |
2887 | BUG_ON(virt_to_cache(objp) != cachep); |
2888 | |
2889 | objp -= obj_offset(cachep); |
2890 | kfree_debugcheck(objp); |
2891 | page = virt_to_head_page(objp); |
2892 | |
2893 | slabp = page->slab_page; |
2894 | |
2895 | if (cachep->flags & SLAB_RED_ZONE) { |
2896 | verify_redzone_free(cachep, objp); |
2897 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2898 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2899 | } |
2900 | if (cachep->flags & SLAB_STORE_USER) |
2901 | *dbg_userword(cachep, objp) = (void *)caller; |
2902 | |
2903 | objnr = obj_to_index(cachep, slabp, objp); |
2904 | |
2905 | BUG_ON(objnr >= cachep->num); |
2906 | BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); |
2907 | |
2908 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
2909 | slab_bufctl(slabp)[objnr] = BUFCTL_FREE; |
2910 | #endif |
2911 | if (cachep->flags & SLAB_POISON) { |
2912 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2913 | if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { |
2914 | store_stackinfo(cachep, objp, caller); |
2915 | kernel_map_pages(virt_to_page(objp), |
2916 | cachep->size / PAGE_SIZE, 0); |
2917 | } else { |
2918 | poison_obj(cachep, objp, POISON_FREE); |
2919 | } |
2920 | #else |
2921 | poison_obj(cachep, objp, POISON_FREE); |
2922 | #endif |
2923 | } |
2924 | return objp; |
2925 | } |
2926 | |
2927 | static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) |
2928 | { |
2929 | kmem_bufctl_t i; |
2930 | int entries = 0; |
2931 | |
2932 | /* Check slab's freelist to see if this obj is there. */ |
2933 | for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { |
2934 | entries++; |
2935 | if (entries > cachep->num || i >= cachep->num) |
2936 | goto bad; |
2937 | } |
2938 | if (entries != cachep->num - slabp->inuse) { |
2939 | bad: |
2940 | printk(KERN_ERR "slab: Internal list corruption detected in " |
2941 | "cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n", |
2942 | cachep->name, cachep->num, slabp, slabp->inuse, |
2943 | print_tainted()); |
2944 | print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp, |
2945 | sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t), |
2946 | 1); |
2947 | BUG(); |
2948 | } |
2949 | } |
2950 | #else |
2951 | #define kfree_debugcheck(x) do { } while(0) |
2952 | #define cache_free_debugcheck(x,objp,z) (objp) |
2953 | #define check_slabp(x,y) do { } while(0) |
2954 | #endif |
2955 | |
2956 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, |
2957 | bool force_refill) |
2958 | { |
2959 | int batchcount; |
2960 | struct kmem_cache_node *n; |
2961 | struct array_cache *ac; |
2962 | int node; |
2963 | |
2964 | check_irq_off(); |
2965 | node = numa_mem_id(); |
2966 | if (unlikely(force_refill)) |
2967 | goto force_grow; |
2968 | retry: |
2969 | ac = cpu_cache_get(cachep); |
2970 | batchcount = ac->batchcount; |
2971 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
2972 | /* |
2973 | * If there was little recent activity on this cache, then |
2974 | * perform only a partial refill. Otherwise we could generate |
2975 | * refill bouncing. |
2976 | */ |
2977 | batchcount = BATCHREFILL_LIMIT; |
2978 | } |
2979 | n = cachep->node[node]; |
2980 | |
2981 | BUG_ON(ac->avail > 0 || !n); |
2982 | spin_lock(&n->list_lock); |
2983 | |
2984 | /* See if we can refill from the shared array */ |
2985 | if (n->shared && transfer_objects(ac, n->shared, batchcount)) { |
2986 | n->shared->touched = 1; |
2987 | goto alloc_done; |
2988 | } |
2989 | |
2990 | while (batchcount > 0) { |
2991 | struct list_head *entry; |
2992 | struct slab *slabp; |
2993 | /* Get slab alloc is to come from. */ |
2994 | entry = n->slabs_partial.next; |
2995 | if (entry == &n->slabs_partial) { |
2996 | n->free_touched = 1; |
2997 | entry = n->slabs_free.next; |
2998 | if (entry == &n->slabs_free) |
2999 | goto must_grow; |
3000 | } |
3001 | |
3002 | slabp = list_entry(entry, struct slab, list); |
3003 | check_slabp(cachep, slabp); |
3004 | check_spinlock_acquired(cachep); |
3005 | |
3006 | /* |
3007 | * The slab was either on partial or free list so |
3008 | * there must be at least one object available for |
3009 | * allocation. |
3010 | */ |
3011 | BUG_ON(slabp->inuse >= cachep->num); |
3012 | |
3013 | while (slabp->inuse < cachep->num && batchcount--) { |
3014 | STATS_INC_ALLOCED(cachep); |
3015 | STATS_INC_ACTIVE(cachep); |
3016 | STATS_SET_HIGH(cachep); |
3017 | |
3018 | ac_put_obj(cachep, ac, slab_get_obj(cachep, slabp, |
3019 | node)); |
3020 | } |
3021 | check_slabp(cachep, slabp); |
3022 | |
3023 | /* move slabp to correct slabp list: */ |
3024 | list_del(&slabp->list); |
3025 | if (slabp->free == BUFCTL_END) |
3026 | list_add(&slabp->list, &n->slabs_full); |
3027 | else |
3028 | list_add(&slabp->list, &n->slabs_partial); |
3029 | } |
3030 | |
3031 | must_grow: |
3032 | n->free_objects -= ac->avail; |
3033 | alloc_done: |
3034 | spin_unlock(&n->list_lock); |
3035 | |
3036 | if (unlikely(!ac->avail)) { |
3037 | int x; |
3038 | force_grow: |
3039 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); |
3040 | |
3041 | /* cache_grow can reenable interrupts, then ac could change. */ |
3042 | ac = cpu_cache_get(cachep); |
3043 | node = numa_mem_id(); |
3044 | |
3045 | /* no objects in sight? abort */ |
3046 | if (!x && (ac->avail == 0 || force_refill)) |
3047 | return NULL; |
3048 | |
3049 | if (!ac->avail) /* objects refilled by interrupt? */ |
3050 | goto retry; |
3051 | } |
3052 | ac->touched = 1; |
3053 | |
3054 | return ac_get_obj(cachep, ac, flags, force_refill); |
3055 | } |
3056 | |
3057 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, |
3058 | gfp_t flags) |
3059 | { |
3060 | might_sleep_if(flags & __GFP_WAIT); |
3061 | #if DEBUG |
3062 | kmem_flagcheck(cachep, flags); |
3063 | #endif |
3064 | } |
3065 | |
3066 | #if DEBUG |
3067 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, |
3068 | gfp_t flags, void *objp, unsigned long caller) |
3069 | { |
3070 | if (!objp) |
3071 | return objp; |
3072 | if (cachep->flags & SLAB_POISON) { |
3073 | #ifdef CONFIG_DEBUG_PAGEALLOC |
3074 | if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
3075 | kernel_map_pages(virt_to_page(objp), |
3076 | cachep->size / PAGE_SIZE, 1); |
3077 | else |
3078 | check_poison_obj(cachep, objp); |
3079 | #else |
3080 | check_poison_obj(cachep, objp); |
3081 | #endif |
3082 | poison_obj(cachep, objp, POISON_INUSE); |
3083 | } |
3084 | if (cachep->flags & SLAB_STORE_USER) |
3085 | *dbg_userword(cachep, objp) = (void *)caller; |
3086 | |
3087 | if (cachep->flags & SLAB_RED_ZONE) { |
3088 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || |
3089 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
3090 | slab_error(cachep, "double free, or memory outside" |
3091 | " object was overwritten"); |
3092 | printk(KERN_ERR |
3093 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", |
3094 | objp, *dbg_redzone1(cachep, objp), |
3095 | *dbg_redzone2(cachep, objp)); |
3096 | } |
3097 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
3098 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
3099 | } |
3100 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
3101 | { |
3102 | struct slab *slabp; |
3103 | unsigned objnr; |
3104 | |
3105 | slabp = virt_to_head_page(objp)->slab_page; |
3106 | objnr = (unsigned)(objp - slabp->s_mem) / cachep->size; |
3107 | slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; |
3108 | } |
3109 | #endif |
3110 | objp += obj_offset(cachep); |
3111 | if (cachep->ctor && cachep->flags & SLAB_POISON) |
3112 | cachep->ctor(objp); |
3113 | if (ARCH_SLAB_MINALIGN && |
3114 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { |
3115 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", |
3116 | objp, (int)ARCH_SLAB_MINALIGN); |
3117 | } |
3118 | return objp; |
3119 | } |
3120 | #else |
3121 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
3122 | #endif |
3123 | |
3124 | static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) |
3125 | { |
3126 | if (cachep == kmem_cache) |
3127 | return false; |
3128 | |
3129 | return should_failslab(cachep->object_size, flags, cachep->flags); |
3130 | } |
3131 | |
3132 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3133 | { |
3134 | void *objp; |
3135 | struct array_cache *ac; |
3136 | bool force_refill = false; |
3137 | |
3138 | check_irq_off(); |
3139 | |
3140 | ac = cpu_cache_get(cachep); |
3141 | if (likely(ac->avail)) { |
3142 | ac->touched = 1; |
3143 | objp = ac_get_obj(cachep, ac, flags, false); |
3144 | |
3145 | /* |
3146 | * Allow for the possibility all avail objects are not allowed |
3147 | * by the current flags |
3148 | */ |
3149 | if (objp) { |
3150 | STATS_INC_ALLOCHIT(cachep); |
3151 | goto out; |
3152 | } |
3153 | force_refill = true; |
3154 | } |
3155 | |
3156 | STATS_INC_ALLOCMISS(cachep); |
3157 | objp = cache_alloc_refill(cachep, flags, force_refill); |
3158 | /* |
3159 | * the 'ac' may be updated by cache_alloc_refill(), |
3160 | * and kmemleak_erase() requires its correct value. |
3161 | */ |
3162 | ac = cpu_cache_get(cachep); |
3163 | |
3164 | out: |
3165 | /* |
3166 | * To avoid a false negative, if an object that is in one of the |
3167 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't |
3168 | * treat the array pointers as a reference to the object. |
3169 | */ |
3170 | if (objp) |
3171 | kmemleak_erase(&ac->entry[ac->avail]); |
3172 | return objp; |
3173 | } |
3174 | |
3175 | #ifdef CONFIG_NUMA |
3176 | /* |
3177 | * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. |
3178 | * |
3179 | * If we are in_interrupt, then process context, including cpusets and |
3180 | * mempolicy, may not apply and should not be used for allocation policy. |
3181 | */ |
3182 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) |
3183 | { |
3184 | int nid_alloc, nid_here; |
3185 | |
3186 | if (in_interrupt() || (flags & __GFP_THISNODE)) |
3187 | return NULL; |
3188 | nid_alloc = nid_here = numa_mem_id(); |
3189 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) |
3190 | nid_alloc = cpuset_slab_spread_node(); |
3191 | else if (current->mempolicy) |
3192 | nid_alloc = slab_node(); |
3193 | if (nid_alloc != nid_here) |
3194 | return ____cache_alloc_node(cachep, flags, nid_alloc); |
3195 | return NULL; |
3196 | } |
3197 | |
3198 | /* |
3199 | * Fallback function if there was no memory available and no objects on a |
3200 | * certain node and fall back is permitted. First we scan all the |
3201 | * available node for available objects. If that fails then we |
3202 | * perform an allocation without specifying a node. This allows the page |
3203 | * allocator to do its reclaim / fallback magic. We then insert the |
3204 | * slab into the proper nodelist and then allocate from it. |
3205 | */ |
3206 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) |
3207 | { |
3208 | struct zonelist *zonelist; |
3209 | gfp_t local_flags; |
3210 | struct zoneref *z; |
3211 | struct zone *zone; |
3212 | enum zone_type high_zoneidx = gfp_zone(flags); |
3213 | void *obj = NULL; |
3214 | int nid; |
3215 | unsigned int cpuset_mems_cookie; |
3216 | |
3217 | if (flags & __GFP_THISNODE) |
3218 | return NULL; |
3219 | |
3220 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
3221 | |
3222 | retry_cpuset: |
3223 | cpuset_mems_cookie = get_mems_allowed(); |
3224 | zonelist = node_zonelist(slab_node(), flags); |
3225 | |
3226 | retry: |
3227 | /* |
3228 | * Look through allowed nodes for objects available |
3229 | * from existing per node queues. |
3230 | */ |
3231 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
3232 | nid = zone_to_nid(zone); |
3233 | |
3234 | if (cpuset_zone_allowed_hardwall(zone, flags) && |
3235 | cache->node[nid] && |
3236 | cache->node[nid]->free_objects) { |
3237 | obj = ____cache_alloc_node(cache, |
3238 | flags | GFP_THISNODE, nid); |
3239 | if (obj) |
3240 | break; |
3241 | } |
3242 | } |
3243 | |
3244 | if (!obj) { |
3245 | /* |
3246 | * This allocation will be performed within the constraints |
3247 | * of the current cpuset / memory policy requirements. |
3248 | * We may trigger various forms of reclaim on the allowed |
3249 | * set and go into memory reserves if necessary. |
3250 | */ |
3251 | if (local_flags & __GFP_WAIT) |
3252 | local_irq_enable(); |
3253 | kmem_flagcheck(cache, flags); |
3254 | obj = kmem_getpages(cache, local_flags, numa_mem_id()); |
3255 | if (local_flags & __GFP_WAIT) |
3256 | local_irq_disable(); |
3257 | if (obj) { |
3258 | /* |
3259 | * Insert into the appropriate per node queues |
3260 | */ |
3261 | nid = page_to_nid(virt_to_page(obj)); |
3262 | if (cache_grow(cache, flags, nid, obj)) { |
3263 | obj = ____cache_alloc_node(cache, |
3264 | flags | GFP_THISNODE, nid); |
3265 | if (!obj) |
3266 | /* |
3267 | * Another processor may allocate the |
3268 | * objects in the slab since we are |
3269 | * not holding any locks. |
3270 | */ |
3271 | goto retry; |
3272 | } else { |
3273 | /* cache_grow already freed obj */ |
3274 | obj = NULL; |
3275 | } |
3276 | } |
3277 | } |
3278 | |
3279 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !obj)) |
3280 | goto retry_cpuset; |
3281 | return obj; |
3282 | } |
3283 | |
3284 | /* |
3285 | * A interface to enable slab creation on nodeid |
3286 | */ |
3287 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, |
3288 | int nodeid) |
3289 | { |
3290 | struct list_head *entry; |
3291 | struct slab *slabp; |
3292 | struct kmem_cache_node *n; |
3293 | void *obj; |
3294 | int x; |
3295 | |
3296 | VM_BUG_ON(nodeid > num_online_nodes()); |
3297 | n = cachep->node[nodeid]; |
3298 | BUG_ON(!n); |
3299 | |
3300 | retry: |
3301 | check_irq_off(); |
3302 | spin_lock(&n->list_lock); |
3303 | entry = n->slabs_partial.next; |
3304 | if (entry == &n->slabs_partial) { |
3305 | n->free_touched = 1; |
3306 | entry = n->slabs_free.next; |
3307 | if (entry == &n->slabs_free) |
3308 | goto must_grow; |
3309 | } |
3310 | |
3311 | slabp = list_entry(entry, struct slab, list); |
3312 | check_spinlock_acquired_node(cachep, nodeid); |
3313 | check_slabp(cachep, slabp); |
3314 | |
3315 | STATS_INC_NODEALLOCS(cachep); |
3316 | STATS_INC_ACTIVE(cachep); |
3317 | STATS_SET_HIGH(cachep); |
3318 | |
3319 | BUG_ON(slabp->inuse == cachep->num); |
3320 | |
3321 | obj = slab_get_obj(cachep, slabp, nodeid); |
3322 | check_slabp(cachep, slabp); |
3323 | n->free_objects--; |
3324 | /* move slabp to correct slabp list: */ |
3325 | list_del(&slabp->list); |
3326 | |
3327 | if (slabp->free == BUFCTL_END) |
3328 | list_add(&slabp->list, &n->slabs_full); |
3329 | else |
3330 | list_add(&slabp->list, &n->slabs_partial); |
3331 | |
3332 | spin_unlock(&n->list_lock); |
3333 | goto done; |
3334 | |
3335 | must_grow: |
3336 | spin_unlock(&n->list_lock); |
3337 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); |
3338 | if (x) |
3339 | goto retry; |
3340 | |
3341 | return fallback_alloc(cachep, flags); |
3342 | |
3343 | done: |
3344 | return obj; |
3345 | } |
3346 | |
3347 | static __always_inline void * |
3348 | slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, |
3349 | unsigned long caller) |
3350 | { |
3351 | unsigned long save_flags; |
3352 | void *ptr; |
3353 | int slab_node = numa_mem_id(); |
3354 | |
3355 | flags &= gfp_allowed_mask; |
3356 | |
3357 | lockdep_trace_alloc(flags); |
3358 | |
3359 | if (slab_should_failslab(cachep, flags)) |
3360 | return NULL; |
3361 | |
3362 | cachep = memcg_kmem_get_cache(cachep, flags); |
3363 | |
3364 | cache_alloc_debugcheck_before(cachep, flags); |
3365 | local_irq_save(save_flags); |
3366 | |
3367 | if (nodeid == NUMA_NO_NODE) |
3368 | nodeid = slab_node; |
3369 | |
3370 | if (unlikely(!cachep->node[nodeid])) { |
3371 | /* Node not bootstrapped yet */ |
3372 | ptr = fallback_alloc(cachep, flags); |
3373 | goto out; |
3374 | } |
3375 | |
3376 | if (nodeid == slab_node) { |
3377 | /* |
3378 | * Use the locally cached objects if possible. |
3379 | * However ____cache_alloc does not allow fallback |
3380 | * to other nodes. It may fail while we still have |
3381 | * objects on other nodes available. |
3382 | */ |
3383 | ptr = ____cache_alloc(cachep, flags); |
3384 | if (ptr) |
3385 | goto out; |
3386 | } |
3387 | /* ___cache_alloc_node can fall back to other nodes */ |
3388 | ptr = ____cache_alloc_node(cachep, flags, nodeid); |
3389 | out: |
3390 | local_irq_restore(save_flags); |
3391 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
3392 | kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, |
3393 | flags); |
3394 | |
3395 | if (likely(ptr)) |
3396 | kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); |
3397 | |
3398 | if (unlikely((flags & __GFP_ZERO) && ptr)) |
3399 | memset(ptr, 0, cachep->object_size); |
3400 | |
3401 | return ptr; |
3402 | } |
3403 | |
3404 | static __always_inline void * |
3405 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) |
3406 | { |
3407 | void *objp; |
3408 | |
3409 | if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { |
3410 | objp = alternate_node_alloc(cache, flags); |
3411 | if (objp) |
3412 | goto out; |
3413 | } |
3414 | objp = ____cache_alloc(cache, flags); |
3415 | |
3416 | /* |
3417 | * We may just have run out of memory on the local node. |
3418 | * ____cache_alloc_node() knows how to locate memory on other nodes |
3419 | */ |
3420 | if (!objp) |
3421 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); |
3422 | |
3423 | out: |
3424 | return objp; |
3425 | } |
3426 | #else |
3427 | |
3428 | static __always_inline void * |
3429 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3430 | { |
3431 | return ____cache_alloc(cachep, flags); |
3432 | } |
3433 | |
3434 | #endif /* CONFIG_NUMA */ |
3435 | |
3436 | static __always_inline void * |
3437 | slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) |
3438 | { |
3439 | unsigned long save_flags; |
3440 | void *objp; |
3441 | |
3442 | flags &= gfp_allowed_mask; |
3443 | |
3444 | lockdep_trace_alloc(flags); |
3445 | |
3446 | if (slab_should_failslab(cachep, flags)) |
3447 | return NULL; |
3448 | |
3449 | cachep = memcg_kmem_get_cache(cachep, flags); |
3450 | |
3451 | cache_alloc_debugcheck_before(cachep, flags); |
3452 | local_irq_save(save_flags); |
3453 | objp = __do_cache_alloc(cachep, flags); |
3454 | local_irq_restore(save_flags); |
3455 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
3456 | kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, |
3457 | flags); |
3458 | prefetchw(objp); |
3459 | |
3460 | if (likely(objp)) |
3461 | kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); |
3462 | |
3463 | if (unlikely((flags & __GFP_ZERO) && objp)) |
3464 | memset(objp, 0, cachep->object_size); |
3465 | |
3466 | return objp; |
3467 | } |
3468 | |
3469 | /* |
3470 | * Caller needs to acquire correct kmem_list's list_lock |
3471 | */ |
3472 | static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, |
3473 | int node) |
3474 | { |
3475 | int i; |
3476 | struct kmem_cache_node *n; |
3477 | |
3478 | for (i = 0; i < nr_objects; i++) { |
3479 | void *objp; |
3480 | struct slab *slabp; |
3481 | |
3482 | clear_obj_pfmemalloc(&objpp[i]); |
3483 | objp = objpp[i]; |
3484 | |
3485 | slabp = virt_to_slab(objp); |
3486 | n = cachep->node[node]; |
3487 | list_del(&slabp->list); |
3488 | check_spinlock_acquired_node(cachep, node); |
3489 | check_slabp(cachep, slabp); |
3490 | slab_put_obj(cachep, slabp, objp, node); |
3491 | STATS_DEC_ACTIVE(cachep); |
3492 | n->free_objects++; |
3493 | check_slabp(cachep, slabp); |
3494 | |
3495 | /* fixup slab chains */ |
3496 | if (slabp->inuse == 0) { |
3497 | if (n->free_objects > n->free_limit) { |
3498 | n->free_objects -= cachep->num; |
3499 | /* No need to drop any previously held |
3500 | * lock here, even if we have a off-slab slab |
3501 | * descriptor it is guaranteed to come from |
3502 | * a different cache, refer to comments before |
3503 | * alloc_slabmgmt. |
3504 | */ |
3505 | slab_destroy(cachep, slabp); |
3506 | } else { |
3507 | list_add(&slabp->list, &n->slabs_free); |
3508 | } |
3509 | } else { |
3510 | /* Unconditionally move a slab to the end of the |
3511 | * partial list on free - maximum time for the |
3512 | * other objects to be freed, too. |
3513 | */ |
3514 | list_add_tail(&slabp->list, &n->slabs_partial); |
3515 | } |
3516 | } |
3517 | } |
3518 | |
3519 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) |
3520 | { |
3521 | int batchcount; |
3522 | struct kmem_cache_node *n; |
3523 | int node = numa_mem_id(); |
3524 | |
3525 | batchcount = ac->batchcount; |
3526 | #if DEBUG |
3527 | BUG_ON(!batchcount || batchcount > ac->avail); |
3528 | #endif |
3529 | check_irq_off(); |
3530 | n = cachep->node[node]; |
3531 | spin_lock(&n->list_lock); |
3532 | if (n->shared) { |
3533 | struct array_cache *shared_array = n->shared; |
3534 | int max = shared_array->limit - shared_array->avail; |
3535 | if (max) { |
3536 | if (batchcount > max) |
3537 | batchcount = max; |
3538 | memcpy(&(shared_array->entry[shared_array->avail]), |
3539 | ac->entry, sizeof(void *) * batchcount); |
3540 | shared_array->avail += batchcount; |
3541 | goto free_done; |
3542 | } |
3543 | } |
3544 | |
3545 | free_block(cachep, ac->entry, batchcount, node); |
3546 | free_done: |
3547 | #if STATS |
3548 | { |
3549 | int i = 0; |
3550 | struct list_head *p; |
3551 | |
3552 | p = n->slabs_free.next; |
3553 | while (p != &(n->slabs_free)) { |
3554 | struct slab *slabp; |
3555 | |
3556 | slabp = list_entry(p, struct slab, list); |
3557 | BUG_ON(slabp->inuse); |
3558 | |
3559 | i++; |
3560 | p = p->next; |
3561 | } |
3562 | STATS_SET_FREEABLE(cachep, i); |
3563 | } |
3564 | #endif |
3565 | spin_unlock(&n->list_lock); |
3566 | ac->avail -= batchcount; |
3567 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); |
3568 | } |
3569 | |
3570 | /* |
3571 | * Release an obj back to its cache. If the obj has a constructed state, it must |
3572 | * be in this state _before_ it is released. Called with disabled ints. |
3573 | */ |
3574 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, |
3575 | unsigned long caller) |
3576 | { |
3577 | struct array_cache *ac = cpu_cache_get(cachep); |
3578 | |
3579 | check_irq_off(); |
3580 | kmemleak_free_recursive(objp, cachep->flags); |
3581 | objp = cache_free_debugcheck(cachep, objp, caller); |
3582 | |
3583 | kmemcheck_slab_free(cachep, objp, cachep->object_size); |
3584 | |
3585 | /* |
3586 | * Skip calling cache_free_alien() when the platform is not numa. |
3587 | * This will avoid cache misses that happen while accessing slabp (which |
3588 | * is per page memory reference) to get nodeid. Instead use a global |
3589 | * variable to skip the call, which is mostly likely to be present in |
3590 | * the cache. |
3591 | */ |
3592 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) |
3593 | return; |
3594 | |
3595 | if (likely(ac->avail < ac->limit)) { |
3596 | STATS_INC_FREEHIT(cachep); |
3597 | } else { |
3598 | STATS_INC_FREEMISS(cachep); |
3599 | cache_flusharray(cachep, ac); |
3600 | } |
3601 | |
3602 | ac_put_obj(cachep, ac, objp); |
3603 | } |
3604 | |
3605 | /** |
3606 | * kmem_cache_alloc - Allocate an object |
3607 | * @cachep: The cache to allocate from. |
3608 | * @flags: See kmalloc(). |
3609 | * |
3610 | * Allocate an object from this cache. The flags are only relevant |
3611 | * if the cache has no available objects. |
3612 | */ |
3613 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3614 | { |
3615 | void *ret = slab_alloc(cachep, flags, _RET_IP_); |
3616 | |
3617 | trace_kmem_cache_alloc(_RET_IP_, ret, |
3618 | cachep->object_size, cachep->size, flags); |
3619 | |
3620 | return ret; |
3621 | } |
3622 | EXPORT_SYMBOL(kmem_cache_alloc); |
3623 | |
3624 | #ifdef CONFIG_TRACING |
3625 | void * |
3626 | kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) |
3627 | { |
3628 | void *ret; |
3629 | |
3630 | ret = slab_alloc(cachep, flags, _RET_IP_); |
3631 | |
3632 | trace_kmalloc(_RET_IP_, ret, |
3633 | size, cachep->size, flags); |
3634 | return ret; |
3635 | } |
3636 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
3637 | #endif |
3638 | |
3639 | #ifdef CONFIG_NUMA |
3640 | /** |
3641 | * kmem_cache_alloc_node - Allocate an object on the specified node |
3642 | * @cachep: The cache to allocate from. |
3643 | * @flags: See kmalloc(). |
3644 | * @nodeid: node number of the target node. |
3645 | * |
3646 | * Identical to kmem_cache_alloc but it will allocate memory on the given |
3647 | * node, which can improve the performance for cpu bound structures. |
3648 | * |
3649 | * Fallback to other node is possible if __GFP_THISNODE is not set. |
3650 | */ |
3651 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
3652 | { |
3653 | void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3654 | |
3655 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
3656 | cachep->object_size, cachep->size, |
3657 | flags, nodeid); |
3658 | |
3659 | return ret; |
3660 | } |
3661 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
3662 | |
3663 | #ifdef CONFIG_TRACING |
3664 | void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, |
3665 | gfp_t flags, |
3666 | int nodeid, |
3667 | size_t size) |
3668 | { |
3669 | void *ret; |
3670 | |
3671 | ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3672 | |
3673 | trace_kmalloc_node(_RET_IP_, ret, |
3674 | size, cachep->size, |
3675 | flags, nodeid); |
3676 | return ret; |
3677 | } |
3678 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
3679 | #endif |
3680 | |
3681 | static __always_inline void * |
3682 | __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) |
3683 | { |
3684 | struct kmem_cache *cachep; |
3685 | |
3686 | cachep = kmalloc_slab(size, flags); |
3687 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3688 | return cachep; |
3689 | return kmem_cache_alloc_node_trace(cachep, flags, node, size); |
3690 | } |
3691 | |
3692 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3693 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3694 | { |
3695 | return __do_kmalloc_node(size, flags, node, _RET_IP_); |
3696 | } |
3697 | EXPORT_SYMBOL(__kmalloc_node); |
3698 | |
3699 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, |
3700 | int node, unsigned long caller) |
3701 | { |
3702 | return __do_kmalloc_node(size, flags, node, caller); |
3703 | } |
3704 | EXPORT_SYMBOL(__kmalloc_node_track_caller); |
3705 | #else |
3706 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3707 | { |
3708 | return __do_kmalloc_node(size, flags, node, 0); |
3709 | } |
3710 | EXPORT_SYMBOL(__kmalloc_node); |
3711 | #endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ |
3712 | #endif /* CONFIG_NUMA */ |
3713 | |
3714 | /** |
3715 | * __do_kmalloc - allocate memory |
3716 | * @size: how many bytes of memory are required. |
3717 | * @flags: the type of memory to allocate (see kmalloc). |
3718 | * @caller: function caller for debug tracking of the caller |
3719 | */ |
3720 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, |
3721 | unsigned long caller) |
3722 | { |
3723 | struct kmem_cache *cachep; |
3724 | void *ret; |
3725 | |
3726 | /* If you want to save a few bytes .text space: replace |
3727 | * __ with kmem_. |
3728 | * Then kmalloc uses the uninlined functions instead of the inline |
3729 | * functions. |
3730 | */ |
3731 | cachep = kmalloc_slab(size, flags); |
3732 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3733 | return cachep; |
3734 | ret = slab_alloc(cachep, flags, caller); |
3735 | |
3736 | trace_kmalloc(caller, ret, |
3737 | size, cachep->size, flags); |
3738 | |
3739 | return ret; |
3740 | } |
3741 | |
3742 | |
3743 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3744 | void *__kmalloc(size_t size, gfp_t flags) |
3745 | { |
3746 | return __do_kmalloc(size, flags, _RET_IP_); |
3747 | } |
3748 | EXPORT_SYMBOL(__kmalloc); |
3749 | |
3750 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) |
3751 | { |
3752 | return __do_kmalloc(size, flags, caller); |
3753 | } |
3754 | EXPORT_SYMBOL(__kmalloc_track_caller); |
3755 | |
3756 | #else |
3757 | void *__kmalloc(size_t size, gfp_t flags) |
3758 | { |
3759 | return __do_kmalloc(size, flags, 0); |
3760 | } |
3761 | EXPORT_SYMBOL(__kmalloc); |
3762 | #endif |
3763 | |
3764 | /** |
3765 | * kmem_cache_free - Deallocate an object |
3766 | * @cachep: The cache the allocation was from. |
3767 | * @objp: The previously allocated object. |
3768 | * |
3769 | * Free an object which was previously allocated from this |
3770 | * cache. |
3771 | */ |
3772 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) |
3773 | { |
3774 | unsigned long flags; |
3775 | cachep = cache_from_obj(cachep, objp); |
3776 | if (!cachep) |
3777 | return; |
3778 | |
3779 | local_irq_save(flags); |
3780 | debug_check_no_locks_freed(objp, cachep->object_size); |
3781 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) |
3782 | debug_check_no_obj_freed(objp, cachep->object_size); |
3783 | __cache_free(cachep, objp, _RET_IP_); |
3784 | local_irq_restore(flags); |
3785 | |
3786 | trace_kmem_cache_free(_RET_IP_, objp); |
3787 | } |
3788 | EXPORT_SYMBOL(kmem_cache_free); |
3789 | |
3790 | /** |
3791 | * kfree - free previously allocated memory |
3792 | * @objp: pointer returned by kmalloc. |
3793 | * |
3794 | * If @objp is NULL, no operation is performed. |
3795 | * |
3796 | * Don't free memory not originally allocated by kmalloc() |
3797 | * or you will run into trouble. |
3798 | */ |
3799 | void kfree(const void *objp) |
3800 | { |
3801 | struct kmem_cache *c; |
3802 | unsigned long flags; |
3803 | |
3804 | trace_kfree(_RET_IP_, objp); |
3805 | |
3806 | if (unlikely(ZERO_OR_NULL_PTR(objp))) |
3807 | return; |
3808 | local_irq_save(flags); |
3809 | kfree_debugcheck(objp); |
3810 | c = virt_to_cache(objp); |
3811 | debug_check_no_locks_freed(objp, c->object_size); |
3812 | |
3813 | debug_check_no_obj_freed(objp, c->object_size); |
3814 | __cache_free(c, (void *)objp, _RET_IP_); |
3815 | local_irq_restore(flags); |
3816 | } |
3817 | EXPORT_SYMBOL(kfree); |
3818 | |
3819 | /* |
3820 | * This initializes kmem_cache_node or resizes various caches for all nodes. |
3821 | */ |
3822 | static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) |
3823 | { |
3824 | int node; |
3825 | struct kmem_cache_node *n; |
3826 | struct array_cache *new_shared; |
3827 | struct array_cache **new_alien = NULL; |
3828 | |
3829 | for_each_online_node(node) { |
3830 | |
3831 | if (use_alien_caches) { |
3832 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); |
3833 | if (!new_alien) |
3834 | goto fail; |
3835 | } |
3836 | |
3837 | new_shared = NULL; |
3838 | if (cachep->shared) { |
3839 | new_shared = alloc_arraycache(node, |
3840 | cachep->shared*cachep->batchcount, |
3841 | 0xbaadf00d, gfp); |
3842 | if (!new_shared) { |
3843 | free_alien_cache(new_alien); |
3844 | goto fail; |
3845 | } |
3846 | } |
3847 | |
3848 | n = cachep->node[node]; |
3849 | if (n) { |
3850 | struct array_cache *shared = n->shared; |
3851 | |
3852 | spin_lock_irq(&n->list_lock); |
3853 | |
3854 | if (shared) |
3855 | free_block(cachep, shared->entry, |
3856 | shared->avail, node); |
3857 | |
3858 | n->shared = new_shared; |
3859 | if (!n->alien) { |
3860 | n->alien = new_alien; |
3861 | new_alien = NULL; |
3862 | } |
3863 | n->free_limit = (1 + nr_cpus_node(node)) * |
3864 | cachep->batchcount + cachep->num; |
3865 | spin_unlock_irq(&n->list_lock); |
3866 | kfree(shared); |
3867 | free_alien_cache(new_alien); |
3868 | continue; |
3869 | } |
3870 | n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); |
3871 | if (!n) { |
3872 | free_alien_cache(new_alien); |
3873 | kfree(new_shared); |
3874 | goto fail; |
3875 | } |
3876 | |
3877 | kmem_cache_node_init(n); |
3878 | n->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
3879 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
3880 | n->shared = new_shared; |
3881 | n->alien = new_alien; |
3882 | n->free_limit = (1 + nr_cpus_node(node)) * |
3883 | cachep->batchcount + cachep->num; |
3884 | cachep->node[node] = n; |
3885 | } |
3886 | return 0; |
3887 | |
3888 | fail: |
3889 | if (!cachep->list.next) { |
3890 | /* Cache is not active yet. Roll back what we did */ |
3891 | node--; |
3892 | while (node >= 0) { |
3893 | if (cachep->node[node]) { |
3894 | n = cachep->node[node]; |
3895 | |
3896 | kfree(n->shared); |
3897 | free_alien_cache(n->alien); |
3898 | kfree(n); |
3899 | cachep->node[node] = NULL; |
3900 | } |
3901 | node--; |
3902 | } |
3903 | } |
3904 | return -ENOMEM; |
3905 | } |
3906 | |
3907 | struct ccupdate_struct { |
3908 | struct kmem_cache *cachep; |
3909 | struct array_cache *new[0]; |
3910 | }; |
3911 | |
3912 | static void do_ccupdate_local(void *info) |
3913 | { |
3914 | struct ccupdate_struct *new = info; |
3915 | struct array_cache *old; |
3916 | |
3917 | check_irq_off(); |
3918 | old = cpu_cache_get(new->cachep); |
3919 | |
3920 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; |
3921 | new->new[smp_processor_id()] = old; |
3922 | } |
3923 | |
3924 | /* Always called with the slab_mutex held */ |
3925 | static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3926 | int batchcount, int shared, gfp_t gfp) |
3927 | { |
3928 | struct ccupdate_struct *new; |
3929 | int i; |
3930 | |
3931 | new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *), |
3932 | gfp); |
3933 | if (!new) |
3934 | return -ENOMEM; |
3935 | |
3936 | for_each_online_cpu(i) { |
3937 | new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, |
3938 | batchcount, gfp); |
3939 | if (!new->new[i]) { |
3940 | for (i--; i >= 0; i--) |
3941 | kfree(new->new[i]); |
3942 | kfree(new); |
3943 | return -ENOMEM; |
3944 | } |
3945 | } |
3946 | new->cachep = cachep; |
3947 | |
3948 | on_each_cpu(do_ccupdate_local, (void *)new, 1); |
3949 | |
3950 | check_irq_on(); |
3951 | cachep->batchcount = batchcount; |
3952 | cachep->limit = limit; |
3953 | cachep->shared = shared; |
3954 | |
3955 | for_each_online_cpu(i) { |
3956 | struct array_cache *ccold = new->new[i]; |
3957 | if (!ccold) |
3958 | continue; |
3959 | spin_lock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); |
3960 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); |
3961 | spin_unlock_irq(&cachep->node[cpu_to_mem(i)]->list_lock); |
3962 | kfree(ccold); |
3963 | } |
3964 | kfree(new); |
3965 | return alloc_kmemlist(cachep, gfp); |
3966 | } |
3967 | |
3968 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3969 | int batchcount, int shared, gfp_t gfp) |
3970 | { |
3971 | int ret; |
3972 | struct kmem_cache *c = NULL; |
3973 | int i = 0; |
3974 | |
3975 | ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
3976 | |
3977 | if (slab_state < FULL) |
3978 | return ret; |
3979 | |
3980 | if ((ret < 0) || !is_root_cache(cachep)) |
3981 | return ret; |
3982 | |
3983 | VM_BUG_ON(!mutex_is_locked(&slab_mutex)); |
3984 | for_each_memcg_cache_index(i) { |
3985 | c = cache_from_memcg(cachep, i); |
3986 | if (c) |
3987 | /* return value determined by the parent cache only */ |
3988 | __do_tune_cpucache(c, limit, batchcount, shared, gfp); |
3989 | } |
3990 | |
3991 | return ret; |
3992 | } |
3993 | |
3994 | /* Called with slab_mutex held always */ |
3995 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) |
3996 | { |
3997 | int err; |
3998 | int limit = 0; |
3999 | int shared = 0; |
4000 | int batchcount = 0; |
4001 | |
4002 | if (!is_root_cache(cachep)) { |
4003 | struct kmem_cache *root = memcg_root_cache(cachep); |
4004 | limit = root->limit; |
4005 | shared = root->shared; |
4006 | batchcount = root->batchcount; |
4007 | } |
4008 | |
4009 | if (limit && shared && batchcount) |
4010 | goto skip_setup; |
4011 | /* |
4012 | * The head array serves three purposes: |
4013 | * - create a LIFO ordering, i.e. return objects that are cache-warm |
4014 | * - reduce the number of spinlock operations. |
4015 | * - reduce the number of linked list operations on the slab and |
4016 | * bufctl chains: array operations are cheaper. |
4017 | * The numbers are guessed, we should auto-tune as described by |
4018 | * Bonwick. |
4019 | */ |
4020 | if (cachep->size > 131072) |
4021 | limit = 1; |
4022 | else if (cachep->size > PAGE_SIZE) |
4023 | limit = 8; |
4024 | else if (cachep->size > 1024) |
4025 | limit = 24; |
4026 | else if (cachep->size > 256) |
4027 | limit = 54; |
4028 | else |
4029 | limit = 120; |
4030 | |
4031 | /* |
4032 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound |
4033 | * allocation behaviour: Most allocs on one cpu, most free operations |
4034 | * on another cpu. For these cases, an efficient object passing between |
4035 | * cpus is necessary. This is provided by a shared array. The array |
4036 | * replaces Bonwick's magazine layer. |
4037 | * On uniprocessor, it's functionally equivalent (but less efficient) |
4038 | * to a larger limit. Thus disabled by default. |
4039 | */ |
4040 | shared = 0; |
4041 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) |
4042 | shared = 8; |
4043 | |
4044 | #if DEBUG |
4045 | /* |
4046 | * With debugging enabled, large batchcount lead to excessively long |
4047 | * periods with disabled local interrupts. Limit the batchcount |
4048 | */ |
4049 | if (limit > 32) |
4050 | limit = 32; |
4051 | #endif |
4052 | batchcount = (limit + 1) / 2; |
4053 | skip_setup: |
4054 | err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
4055 | if (err) |
4056 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", |
4057 | cachep->name, -err); |
4058 | return err; |
4059 | } |
4060 | |
4061 | /* |
4062 | * Drain an array if it contains any elements taking the node lock only if |
4063 | * necessary. Note that the node listlock also protects the array_cache |
4064 | * if drain_array() is used on the shared array. |
4065 | */ |
4066 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
4067 | struct array_cache *ac, int force, int node) |
4068 | { |
4069 | int tofree; |
4070 | |
4071 | if (!ac || !ac->avail) |
4072 | return; |
4073 | if (ac->touched && !force) { |
4074 | ac->touched = 0; |
4075 | } else { |
4076 | spin_lock_irq(&n->list_lock); |
4077 | if (ac->avail) { |
4078 | tofree = force ? ac->avail : (ac->limit + 4) / 5; |
4079 | if (tofree > ac->avail) |
4080 | tofree = (ac->avail + 1) / 2; |
4081 | free_block(cachep, ac->entry, tofree, node); |
4082 | ac->avail -= tofree; |
4083 | memmove(ac->entry, &(ac->entry[tofree]), |
4084 | sizeof(void *) * ac->avail); |
4085 | } |
4086 | spin_unlock_irq(&n->list_lock); |
4087 | } |
4088 | } |
4089 | |
4090 | /** |
4091 | * cache_reap - Reclaim memory from caches. |
4092 | * @w: work descriptor |
4093 | * |
4094 | * Called from workqueue/eventd every few seconds. |
4095 | * Purpose: |
4096 | * - clear the per-cpu caches for this CPU. |
4097 | * - return freeable pages to the main free memory pool. |
4098 | * |
4099 | * If we cannot acquire the cache chain mutex then just give up - we'll try |
4100 | * again on the next iteration. |
4101 | */ |
4102 | static void cache_reap(struct work_struct *w) |
4103 | { |
4104 | struct kmem_cache *searchp; |
4105 | struct kmem_cache_node *n; |
4106 | int node = numa_mem_id(); |
4107 | struct delayed_work *work = to_delayed_work(w); |
4108 | |
4109 | if (!mutex_trylock(&slab_mutex)) |
4110 | /* Give up. Setup the next iteration. */ |
4111 | goto out; |
4112 | |
4113 | list_for_each_entry(searchp, &slab_caches, list) { |
4114 | check_irq_on(); |
4115 | |
4116 | /* |
4117 | * We only take the node lock if absolutely necessary and we |
4118 | * have established with reasonable certainty that |
4119 | * we can do some work if the lock was obtained. |
4120 | */ |
4121 | n = searchp->node[node]; |
4122 | |
4123 | reap_alien(searchp, n); |
4124 | |
4125 | drain_array(searchp, n, cpu_cache_get(searchp), 0, node); |
4126 | |
4127 | /* |
4128 | * These are racy checks but it does not matter |
4129 | * if we skip one check or scan twice. |
4130 | */ |
4131 | if (time_after(n->next_reap, jiffies)) |
4132 | goto next; |
4133 | |
4134 | n->next_reap = jiffies + REAPTIMEOUT_LIST3; |
4135 | |
4136 | drain_array(searchp, n, n->shared, 0, node); |
4137 | |
4138 | if (n->free_touched) |
4139 | n->free_touched = 0; |
4140 | else { |
4141 | int freed; |
4142 | |
4143 | freed = drain_freelist(searchp, n, (n->free_limit + |
4144 | 5 * searchp->num - 1) / (5 * searchp->num)); |
4145 | STATS_ADD_REAPED(searchp, freed); |
4146 | } |
4147 | next: |
4148 | cond_resched(); |
4149 | } |
4150 | check_irq_on(); |
4151 | mutex_unlock(&slab_mutex); |
4152 | next_reap_node(); |
4153 | out: |
4154 | /* Set up the next iteration */ |
4155 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); |
4156 | } |
4157 | |
4158 | #ifdef CONFIG_SLABINFO |
4159 | void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) |
4160 | { |
4161 | struct slab *slabp; |
4162 | unsigned long active_objs; |
4163 | unsigned long num_objs; |
4164 | unsigned long active_slabs = 0; |
4165 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; |
4166 | const char *name; |
4167 | char *error = NULL; |
4168 | int node; |
4169 | struct kmem_cache_node *n; |
4170 | |
4171 | active_objs = 0; |
4172 | num_slabs = 0; |
4173 | for_each_online_node(node) { |
4174 | n = cachep->node[node]; |
4175 | if (!n) |
4176 | continue; |
4177 | |
4178 | check_irq_on(); |
4179 | spin_lock_irq(&n->list_lock); |
4180 | |
4181 | list_for_each_entry(slabp, &n->slabs_full, list) { |
4182 | if (slabp->inuse != cachep->num && !error) |
4183 | error = "slabs_full accounting error"; |
4184 | active_objs += cachep->num; |
4185 | active_slabs++; |
4186 | } |
4187 | list_for_each_entry(slabp, &n->slabs_partial, list) { |
4188 | if (slabp->inuse == cachep->num && !error) |
4189 | error = "slabs_partial inuse accounting error"; |
4190 | if (!slabp->inuse && !error) |
4191 | error = "slabs_partial/inuse accounting error"; |
4192 | active_objs += slabp->inuse; |
4193 | active_slabs++; |
4194 | } |
4195 | list_for_each_entry(slabp, &n->slabs_free, list) { |
4196 | if (slabp->inuse && !error) |
4197 | error = "slabs_free/inuse accounting error"; |
4198 | num_slabs++; |
4199 | } |
4200 | free_objects += n->free_objects; |
4201 | if (n->shared) |
4202 | shared_avail += n->shared->avail; |
4203 | |
4204 | spin_unlock_irq(&n->list_lock); |
4205 | } |
4206 | num_slabs += active_slabs; |
4207 | num_objs = num_slabs * cachep->num; |
4208 | if (num_objs - active_objs != free_objects && !error) |
4209 | error = "free_objects accounting error"; |
4210 | |
4211 | name = cachep->name; |
4212 | if (error) |
4213 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); |
4214 | |
4215 | sinfo->active_objs = active_objs; |
4216 | sinfo->num_objs = num_objs; |
4217 | sinfo->active_slabs = active_slabs; |
4218 | sinfo->num_slabs = num_slabs; |
4219 | sinfo->shared_avail = shared_avail; |
4220 | sinfo->limit = cachep->limit; |
4221 | sinfo->batchcount = cachep->batchcount; |
4222 | sinfo->shared = cachep->shared; |
4223 | sinfo->objects_per_slab = cachep->num; |
4224 | sinfo->cache_order = cachep->gfporder; |
4225 | } |
4226 | |
4227 | void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) |
4228 | { |
4229 | #if STATS |
4230 | { /* node stats */ |
4231 | unsigned long high = cachep->high_mark; |
4232 | unsigned long allocs = cachep->num_allocations; |
4233 | unsigned long grown = cachep->grown; |
4234 | unsigned long reaped = cachep->reaped; |
4235 | unsigned long errors = cachep->errors; |
4236 | unsigned long max_freeable = cachep->max_freeable; |
4237 | unsigned long node_allocs = cachep->node_allocs; |
4238 | unsigned long node_frees = cachep->node_frees; |
4239 | unsigned long overflows = cachep->node_overflow; |
4240 | |
4241 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " |
4242 | "%4lu %4lu %4lu %4lu %4lu", |
4243 | allocs, high, grown, |
4244 | reaped, errors, max_freeable, node_allocs, |
4245 | node_frees, overflows); |
4246 | } |
4247 | /* cpu stats */ |
4248 | { |
4249 | unsigned long allochit = atomic_read(&cachep->allochit); |
4250 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
4251 | unsigned long freehit = atomic_read(&cachep->freehit); |
4252 | unsigned long freemiss = atomic_read(&cachep->freemiss); |
4253 | |
4254 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
4255 | allochit, allocmiss, freehit, freemiss); |
4256 | } |
4257 | #endif |
4258 | } |
4259 | |
4260 | #define MAX_SLABINFO_WRITE 128 |
4261 | /** |
4262 | * slabinfo_write - Tuning for the slab allocator |
4263 | * @file: unused |
4264 | * @buffer: user buffer |
4265 | * @count: data length |
4266 | * @ppos: unused |
4267 | */ |
4268 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
4269 | size_t count, loff_t *ppos) |
4270 | { |
4271 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; |
4272 | int limit, batchcount, shared, res; |
4273 | struct kmem_cache *cachep; |
4274 | |
4275 | if (count > MAX_SLABINFO_WRITE) |
4276 | return -EINVAL; |
4277 | if (copy_from_user(&kbuf, buffer, count)) |
4278 | return -EFAULT; |
4279 | kbuf[MAX_SLABINFO_WRITE] = '\0'; |
4280 | |
4281 | tmp = strchr(kbuf, ' '); |
4282 | if (!tmp) |
4283 | return -EINVAL; |
4284 | *tmp = '\0'; |
4285 | tmp++; |
4286 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
4287 | return -EINVAL; |
4288 | |
4289 | /* Find the cache in the chain of caches. */ |
4290 | mutex_lock(&slab_mutex); |
4291 | res = -EINVAL; |
4292 | list_for_each_entry(cachep, &slab_caches, list) { |
4293 | if (!strcmp(cachep->name, kbuf)) { |
4294 | if (limit < 1 || batchcount < 1 || |
4295 | batchcount > limit || shared < 0) { |
4296 | res = 0; |
4297 | } else { |
4298 | res = do_tune_cpucache(cachep, limit, |
4299 | batchcount, shared, |
4300 | GFP_KERNEL); |
4301 | } |
4302 | break; |
4303 | } |
4304 | } |
4305 | mutex_unlock(&slab_mutex); |
4306 | if (res >= 0) |
4307 | res = count; |
4308 | return res; |
4309 | } |
4310 | |
4311 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4312 | |
4313 | static void *leaks_start(struct seq_file *m, loff_t *pos) |
4314 | { |
4315 | mutex_lock(&slab_mutex); |
4316 | return seq_list_start(&slab_caches, *pos); |
4317 | } |
4318 | |
4319 | static inline int add_caller(unsigned long *n, unsigned long v) |
4320 | { |
4321 | unsigned long *p; |
4322 | int l; |
4323 | if (!v) |
4324 | return 1; |
4325 | l = n[1]; |
4326 | p = n + 2; |
4327 | while (l) { |
4328 | int i = l/2; |
4329 | unsigned long *q = p + 2 * i; |
4330 | if (*q == v) { |
4331 | q[1]++; |
4332 | return 1; |
4333 | } |
4334 | if (*q > v) { |
4335 | l = i; |
4336 | } else { |
4337 | p = q + 2; |
4338 | l -= i + 1; |
4339 | } |
4340 | } |
4341 | if (++n[1] == n[0]) |
4342 | return 0; |
4343 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); |
4344 | p[0] = v; |
4345 | p[1] = 1; |
4346 | return 1; |
4347 | } |
4348 | |
4349 | static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s) |
4350 | { |
4351 | void *p; |
4352 | int i; |
4353 | if (n[0] == n[1]) |
4354 | return; |
4355 | for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) { |
4356 | if (slab_bufctl(s)[i] != BUFCTL_ACTIVE) |
4357 | continue; |
4358 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) |
4359 | return; |
4360 | } |
4361 | } |
4362 | |
4363 | static void show_symbol(struct seq_file *m, unsigned long address) |
4364 | { |
4365 | #ifdef CONFIG_KALLSYMS |
4366 | unsigned long offset, size; |
4367 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; |
4368 | |
4369 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { |
4370 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); |
4371 | if (modname[0]) |
4372 | seq_printf(m, " [%s]", modname); |
4373 | return; |
4374 | } |
4375 | #endif |
4376 | seq_printf(m, "%p", (void *)address); |
4377 | } |
4378 | |
4379 | static int leaks_show(struct seq_file *m, void *p) |
4380 | { |
4381 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); |
4382 | struct slab *slabp; |
4383 | struct kmem_cache_node *n; |
4384 | const char *name; |
4385 | unsigned long *x = m->private; |
4386 | int node; |
4387 | int i; |
4388 | |
4389 | if (!(cachep->flags & SLAB_STORE_USER)) |
4390 | return 0; |
4391 | if (!(cachep->flags & SLAB_RED_ZONE)) |
4392 | return 0; |
4393 | |
4394 | /* OK, we can do it */ |
4395 | |
4396 | x[1] = 0; |
4397 | |
4398 | for_each_online_node(node) { |
4399 | n = cachep->node[node]; |
4400 | if (!n) |
4401 | continue; |
4402 | |
4403 | check_irq_on(); |
4404 | spin_lock_irq(&n->list_lock); |
4405 | |
4406 | list_for_each_entry(slabp, &n->slabs_full, list) |
4407 | handle_slab(x, cachep, slabp); |
4408 | list_for_each_entry(slabp, &n->slabs_partial, list) |
4409 | handle_slab(x, cachep, slabp); |
4410 | spin_unlock_irq(&n->list_lock); |
4411 | } |
4412 | name = cachep->name; |
4413 | if (x[0] == x[1]) { |
4414 | /* Increase the buffer size */ |
4415 | mutex_unlock(&slab_mutex); |
4416 | m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL); |
4417 | if (!m->private) { |
4418 | /* Too bad, we are really out */ |
4419 | m->private = x; |
4420 | mutex_lock(&slab_mutex); |
4421 | return -ENOMEM; |
4422 | } |
4423 | *(unsigned long *)m->private = x[0] * 2; |
4424 | kfree(x); |
4425 | mutex_lock(&slab_mutex); |
4426 | /* Now make sure this entry will be retried */ |
4427 | m->count = m->size; |
4428 | return 0; |
4429 | } |
4430 | for (i = 0; i < x[1]; i++) { |
4431 | seq_printf(m, "%s: %lu ", name, x[2*i+3]); |
4432 | show_symbol(m, x[2*i+2]); |
4433 | seq_putc(m, '\n'); |
4434 | } |
4435 | |
4436 | return 0; |
4437 | } |
4438 | |
4439 | static const struct seq_operations slabstats_op = { |
4440 | .start = leaks_start, |
4441 | .next = slab_next, |
4442 | .stop = slab_stop, |
4443 | .show = leaks_show, |
4444 | }; |
4445 | |
4446 | static int slabstats_open(struct inode *inode, struct file *file) |
4447 | { |
4448 | unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); |
4449 | int ret = -ENOMEM; |
4450 | if (n) { |
4451 | ret = seq_open(file, &slabstats_op); |
4452 | if (!ret) { |
4453 | struct seq_file *m = file->private_data; |
4454 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); |
4455 | m->private = n; |
4456 | n = NULL; |
4457 | } |
4458 | kfree(n); |
4459 | } |
4460 | return ret; |
4461 | } |
4462 | |
4463 | static const struct file_operations proc_slabstats_operations = { |
4464 | .open = slabstats_open, |
4465 | .read = seq_read, |
4466 | .llseek = seq_lseek, |
4467 | .release = seq_release_private, |
4468 | }; |
4469 | #endif |
4470 | |
4471 | static int __init slab_proc_init(void) |
4472 | { |
4473 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4474 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); |
4475 | #endif |
4476 | return 0; |
4477 | } |
4478 | module_init(slab_proc_init); |
4479 | #endif |
4480 | |
4481 | /** |
4482 | * ksize - get the actual amount of memory allocated for a given object |
4483 | * @objp: Pointer to the object |
4484 | * |
4485 | * kmalloc may internally round up allocations and return more memory |
4486 | * than requested. ksize() can be used to determine the actual amount of |
4487 | * memory allocated. The caller may use this additional memory, even though |
4488 | * a smaller amount of memory was initially specified with the kmalloc call. |
4489 | * The caller must guarantee that objp points to a valid object previously |
4490 | * allocated with either kmalloc() or kmem_cache_alloc(). The object |
4491 | * must not be freed during the duration of the call. |
4492 | */ |
4493 | size_t ksize(const void *objp) |
4494 | { |
4495 | BUG_ON(!objp); |
4496 | if (unlikely(objp == ZERO_SIZE_PTR)) |
4497 | return 0; |
4498 | |
4499 | return virt_to_cache(objp)->object_size; |
4500 | } |
4501 | EXPORT_SYMBOL(ksize); |
4502 |
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