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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 "slab.h" |
91 | #include <linux/mm.h> |
92 | #include <linux/poison.h> |
93 | #include <linux/swap.h> |
94 | #include <linux/cache.h> |
95 | #include <linux/interrupt.h> |
96 | #include <linux/init.h> |
97 | #include <linux/compiler.h> |
98 | #include <linux/cpuset.h> |
99 | #include <linux/proc_fs.h> |
100 | #include <linux/seq_file.h> |
101 | #include <linux/notifier.h> |
102 | #include <linux/kallsyms.h> |
103 | #include <linux/cpu.h> |
104 | #include <linux/sysctl.h> |
105 | #include <linux/module.h> |
106 | #include <linux/rcupdate.h> |
107 | #include <linux/string.h> |
108 | #include <linux/uaccess.h> |
109 | #include <linux/nodemask.h> |
110 | #include <linux/kmemleak.h> |
111 | #include <linux/mempolicy.h> |
112 | #include <linux/mutex.h> |
113 | #include <linux/fault-inject.h> |
114 | #include <linux/rtmutex.h> |
115 | #include <linux/reciprocal_div.h> |
116 | #include <linux/debugobjects.h> |
117 | #include <linux/kmemcheck.h> |
118 | #include <linux/memory.h> |
119 | #include <linux/prefetch.h> |
120 | |
121 | #include <net/sock.h> |
122 | |
123 | #include <asm/cacheflush.h> |
124 | #include <asm/tlbflush.h> |
125 | #include <asm/page.h> |
126 | |
127 | #include <trace/events/kmem.h> |
128 | |
129 | #include "internal.h" |
130 | |
131 | /* |
132 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. |
133 | * 0 for faster, smaller code (especially in the critical paths). |
134 | * |
135 | * STATS - 1 to collect stats for /proc/slabinfo. |
136 | * 0 for faster, smaller code (especially in the critical paths). |
137 | * |
138 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) |
139 | */ |
140 | |
141 | #ifdef CONFIG_DEBUG_SLAB |
142 | #define DEBUG 1 |
143 | #define STATS 1 |
144 | #define FORCED_DEBUG 1 |
145 | #else |
146 | #define DEBUG 0 |
147 | #define STATS 0 |
148 | #define FORCED_DEBUG 0 |
149 | #endif |
150 | |
151 | /* Shouldn't this be in a header file somewhere? */ |
152 | #define BYTES_PER_WORD sizeof(void *) |
153 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) |
154 | |
155 | #ifndef ARCH_KMALLOC_FLAGS |
156 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN |
157 | #endif |
158 | |
159 | /* |
160 | * true if a page was allocated from pfmemalloc reserves for network-based |
161 | * swap |
162 | */ |
163 | static bool pfmemalloc_active __read_mostly; |
164 | |
165 | /* Legal flag mask for kmem_cache_create(). */ |
166 | #if DEBUG |
167 | # define CREATE_MASK (SLAB_RED_ZONE | \ |
168 | SLAB_POISON | SLAB_HWCACHE_ALIGN | \ |
169 | SLAB_CACHE_DMA | \ |
170 | SLAB_STORE_USER | \ |
171 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
172 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ |
173 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) |
174 | #else |
175 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ |
176 | SLAB_CACHE_DMA | \ |
177 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
178 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ |
179 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) |
180 | #endif |
181 | |
182 | /* |
183 | * kmem_bufctl_t: |
184 | * |
185 | * Bufctl's are used for linking objs within a slab |
186 | * linked offsets. |
187 | * |
188 | * This implementation relies on "struct page" for locating the cache & |
189 | * slab an object belongs to. |
190 | * This allows the bufctl structure to be small (one int), but limits |
191 | * the number of objects a slab (not a cache) can contain when off-slab |
192 | * bufctls are used. The limit is the size of the largest general cache |
193 | * that does not use off-slab slabs. |
194 | * For 32bit archs with 4 kB pages, is this 56. |
195 | * This is not serious, as it is only for large objects, when it is unwise |
196 | * to have too many per slab. |
197 | * Note: This limit can be raised by introducing a general cache whose size |
198 | * is less than 512 (PAGE_SIZE<<3), but greater than 256. |
199 | */ |
200 | |
201 | typedef unsigned int kmem_bufctl_t; |
202 | #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) |
203 | #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) |
204 | #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) |
205 | #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) |
206 | |
207 | /* |
208 | * struct slab_rcu |
209 | * |
210 | * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to |
211 | * arrange for kmem_freepages to be called via RCU. This is useful if |
212 | * we need to approach a kernel structure obliquely, from its address |
213 | * obtained without the usual locking. We can lock the structure to |
214 | * stabilize it and check it's still at the given address, only if we |
215 | * can be sure that the memory has not been meanwhile reused for some |
216 | * other kind of object (which our subsystem's lock might corrupt). |
217 | * |
218 | * rcu_read_lock before reading the address, then rcu_read_unlock after |
219 | * taking the spinlock within the structure expected at that address. |
220 | */ |
221 | struct slab_rcu { |
222 | struct rcu_head head; |
223 | struct kmem_cache *cachep; |
224 | void *addr; |
225 | }; |
226 | |
227 | /* |
228 | * struct slab |
229 | * |
230 | * Manages the objs in a slab. Placed either at the beginning of mem allocated |
231 | * for a slab, or allocated from an general cache. |
232 | * Slabs are chained into three list: fully used, partial, fully free slabs. |
233 | */ |
234 | struct slab { |
235 | union { |
236 | struct { |
237 | struct list_head list; |
238 | unsigned long colouroff; |
239 | void *s_mem; /* including colour offset */ |
240 | unsigned int inuse; /* num of objs active in slab */ |
241 | kmem_bufctl_t free; |
242 | unsigned short nodeid; |
243 | }; |
244 | struct slab_rcu __slab_cover_slab_rcu; |
245 | }; |
246 | }; |
247 | |
248 | /* |
249 | * struct array_cache |
250 | * |
251 | * Purpose: |
252 | * - LIFO ordering, to hand out cache-warm objects from _alloc |
253 | * - reduce the number of linked list operations |
254 | * - reduce spinlock operations |
255 | * |
256 | * The limit is stored in the per-cpu structure to reduce the data cache |
257 | * footprint. |
258 | * |
259 | */ |
260 | struct array_cache { |
261 | unsigned int avail; |
262 | unsigned int limit; |
263 | unsigned int batchcount; |
264 | unsigned int touched; |
265 | spinlock_t lock; |
266 | void *entry[]; /* |
267 | * Must have this definition in here for the proper |
268 | * alignment of array_cache. Also simplifies accessing |
269 | * the entries. |
270 | * |
271 | * Entries should not be directly dereferenced as |
272 | * entries belonging to slabs marked pfmemalloc will |
273 | * have the lower bits set SLAB_OBJ_PFMEMALLOC |
274 | */ |
275 | }; |
276 | |
277 | #define SLAB_OBJ_PFMEMALLOC 1 |
278 | static inline bool is_obj_pfmemalloc(void *objp) |
279 | { |
280 | return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; |
281 | } |
282 | |
283 | static inline void set_obj_pfmemalloc(void **objp) |
284 | { |
285 | *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); |
286 | return; |
287 | } |
288 | |
289 | static inline void clear_obj_pfmemalloc(void **objp) |
290 | { |
291 | *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); |
292 | } |
293 | |
294 | /* |
295 | * bootstrap: The caches do not work without cpuarrays anymore, but the |
296 | * cpuarrays are allocated from the generic caches... |
297 | */ |
298 | #define BOOT_CPUCACHE_ENTRIES 1 |
299 | struct arraycache_init { |
300 | struct array_cache cache; |
301 | void *entries[BOOT_CPUCACHE_ENTRIES]; |
302 | }; |
303 | |
304 | /* |
305 | * The slab lists for all objects. |
306 | */ |
307 | struct kmem_list3 { |
308 | struct list_head slabs_partial; /* partial list first, better asm code */ |
309 | struct list_head slabs_full; |
310 | struct list_head slabs_free; |
311 | unsigned long free_objects; |
312 | unsigned int free_limit; |
313 | unsigned int colour_next; /* Per-node cache coloring */ |
314 | spinlock_t list_lock; |
315 | struct array_cache *shared; /* shared per node */ |
316 | struct array_cache **alien; /* on other nodes */ |
317 | unsigned long next_reap; /* updated without locking */ |
318 | int free_touched; /* updated without locking */ |
319 | }; |
320 | |
321 | /* |
322 | * Need this for bootstrapping a per node allocator. |
323 | */ |
324 | #define NUM_INIT_LISTS (3 * MAX_NUMNODES) |
325 | static struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; |
326 | #define CACHE_CACHE 0 |
327 | #define SIZE_AC MAX_NUMNODES |
328 | #define SIZE_L3 (2 * MAX_NUMNODES) |
329 | |
330 | static int drain_freelist(struct kmem_cache *cache, |
331 | struct kmem_list3 *l3, int tofree); |
332 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, |
333 | int node); |
334 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); |
335 | static void cache_reap(struct work_struct *unused); |
336 | |
337 | /* |
338 | * This function must be completely optimized away if a constant is passed to |
339 | * it. Mostly the same as what is in linux/slab.h except it returns an index. |
340 | */ |
341 | static __always_inline int index_of(const size_t size) |
342 | { |
343 | extern void __bad_size(void); |
344 | |
345 | if (__builtin_constant_p(size)) { |
346 | int i = 0; |
347 | |
348 | #define CACHE(x) \ |
349 | if (size <=x) \ |
350 | return i; \ |
351 | else \ |
352 | i++; |
353 | #include <linux/kmalloc_sizes.h> |
354 | #undef CACHE |
355 | __bad_size(); |
356 | } else |
357 | __bad_size(); |
358 | return 0; |
359 | } |
360 | |
361 | static int slab_early_init = 1; |
362 | |
363 | #define INDEX_AC index_of(sizeof(struct arraycache_init)) |
364 | #define INDEX_L3 index_of(sizeof(struct kmem_list3)) |
365 | |
366 | static void kmem_list3_init(struct kmem_list3 *parent) |
367 | { |
368 | INIT_LIST_HEAD(&parent->slabs_full); |
369 | INIT_LIST_HEAD(&parent->slabs_partial); |
370 | INIT_LIST_HEAD(&parent->slabs_free); |
371 | parent->shared = NULL; |
372 | parent->alien = NULL; |
373 | parent->colour_next = 0; |
374 | spin_lock_init(&parent->list_lock); |
375 | parent->free_objects = 0; |
376 | parent->free_touched = 0; |
377 | } |
378 | |
379 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ |
380 | do { \ |
381 | INIT_LIST_HEAD(listp); \ |
382 | list_splice(&(cachep->nodelists[nodeid]->slab), listp); \ |
383 | } while (0) |
384 | |
385 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ |
386 | do { \ |
387 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ |
388 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ |
389 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ |
390 | } while (0) |
391 | |
392 | #define CFLGS_OFF_SLAB (0x80000000UL) |
393 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
394 | |
395 | #define BATCHREFILL_LIMIT 16 |
396 | /* |
397 | * Optimization question: fewer reaps means less probability for unnessary |
398 | * cpucache drain/refill cycles. |
399 | * |
400 | * OTOH the cpuarrays can contain lots of objects, |
401 | * which could lock up otherwise freeable slabs. |
402 | */ |
403 | #define REAPTIMEOUT_CPUC (2*HZ) |
404 | #define REAPTIMEOUT_LIST3 (4*HZ) |
405 | |
406 | #if STATS |
407 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
408 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
409 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
410 | #define STATS_INC_GROWN(x) ((x)->grown++) |
411 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) |
412 | #define STATS_SET_HIGH(x) \ |
413 | do { \ |
414 | if ((x)->num_active > (x)->high_mark) \ |
415 | (x)->high_mark = (x)->num_active; \ |
416 | } while (0) |
417 | #define STATS_INC_ERR(x) ((x)->errors++) |
418 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
419 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
420 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) |
421 | #define STATS_SET_FREEABLE(x, i) \ |
422 | do { \ |
423 | if ((x)->max_freeable < i) \ |
424 | (x)->max_freeable = i; \ |
425 | } while (0) |
426 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
427 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
428 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
429 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
430 | #else |
431 | #define STATS_INC_ACTIVE(x) do { } while (0) |
432 | #define STATS_DEC_ACTIVE(x) do { } while (0) |
433 | #define STATS_INC_ALLOCED(x) do { } while (0) |
434 | #define STATS_INC_GROWN(x) do { } while (0) |
435 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) |
436 | #define STATS_SET_HIGH(x) do { } while (0) |
437 | #define STATS_INC_ERR(x) do { } while (0) |
438 | #define STATS_INC_NODEALLOCS(x) do { } while (0) |
439 | #define STATS_INC_NODEFREES(x) do { } while (0) |
440 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) |
441 | #define STATS_SET_FREEABLE(x, i) do { } while (0) |
442 | #define STATS_INC_ALLOCHIT(x) do { } while (0) |
443 | #define STATS_INC_ALLOCMISS(x) do { } while (0) |
444 | #define STATS_INC_FREEHIT(x) do { } while (0) |
445 | #define STATS_INC_FREEMISS(x) do { } while (0) |
446 | #endif |
447 | |
448 | #if DEBUG |
449 | |
450 | /* |
451 | * memory layout of objects: |
452 | * 0 : objp |
453 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that |
454 | * the end of an object is aligned with the end of the real |
455 | * allocation. Catches writes behind the end of the allocation. |
456 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: |
457 | * redzone word. |
458 | * cachep->obj_offset: The real object. |
459 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
460 | * cachep->size - 1* BYTES_PER_WORD: last caller address |
461 | * [BYTES_PER_WORD long] |
462 | */ |
463 | static int obj_offset(struct kmem_cache *cachep) |
464 | { |
465 | return cachep->obj_offset; |
466 | } |
467 | |
468 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) |
469 | { |
470 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
471 | return (unsigned long long*) (objp + obj_offset(cachep) - |
472 | sizeof(unsigned long long)); |
473 | } |
474 | |
475 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) |
476 | { |
477 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
478 | if (cachep->flags & SLAB_STORE_USER) |
479 | return (unsigned long long *)(objp + cachep->size - |
480 | sizeof(unsigned long long) - |
481 | REDZONE_ALIGN); |
482 | return (unsigned long long *) (objp + cachep->size - |
483 | sizeof(unsigned long long)); |
484 | } |
485 | |
486 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) |
487 | { |
488 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
489 | return (void **)(objp + cachep->size - BYTES_PER_WORD); |
490 | } |
491 | |
492 | #else |
493 | |
494 | #define obj_offset(x) 0 |
495 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
496 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
497 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
498 | |
499 | #endif |
500 | |
501 | #ifdef CONFIG_TRACING |
502 | size_t slab_buffer_size(struct kmem_cache *cachep) |
503 | { |
504 | return cachep->size; |
505 | } |
506 | EXPORT_SYMBOL(slab_buffer_size); |
507 | #endif |
508 | |
509 | /* |
510 | * Do not go above this order unless 0 objects fit into the slab or |
511 | * overridden on the command line. |
512 | */ |
513 | #define SLAB_MAX_ORDER_HI 1 |
514 | #define SLAB_MAX_ORDER_LO 0 |
515 | static int slab_max_order = SLAB_MAX_ORDER_LO; |
516 | static bool slab_max_order_set __initdata; |
517 | |
518 | static inline struct kmem_cache *page_get_cache(struct page *page) |
519 | { |
520 | page = compound_head(page); |
521 | BUG_ON(!PageSlab(page)); |
522 | return page->slab_cache; |
523 | } |
524 | |
525 | static inline struct kmem_cache *virt_to_cache(const void *obj) |
526 | { |
527 | struct page *page = virt_to_head_page(obj); |
528 | return page->slab_cache; |
529 | } |
530 | |
531 | static inline struct slab *virt_to_slab(const void *obj) |
532 | { |
533 | struct page *page = virt_to_head_page(obj); |
534 | |
535 | VM_BUG_ON(!PageSlab(page)); |
536 | return page->slab_page; |
537 | } |
538 | |
539 | static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, |
540 | unsigned int idx) |
541 | { |
542 | return slab->s_mem + cache->size * idx; |
543 | } |
544 | |
545 | /* |
546 | * We want to avoid an expensive divide : (offset / cache->size) |
547 | * Using the fact that size is a constant for a particular cache, |
548 | * we can replace (offset / cache->size) by |
549 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) |
550 | */ |
551 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, |
552 | const struct slab *slab, void *obj) |
553 | { |
554 | u32 offset = (obj - slab->s_mem); |
555 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); |
556 | } |
557 | |
558 | /* |
559 | * These are the default caches for kmalloc. Custom caches can have other sizes. |
560 | */ |
561 | struct cache_sizes malloc_sizes[] = { |
562 | #define CACHE(x) { .cs_size = (x) }, |
563 | #include <linux/kmalloc_sizes.h> |
564 | CACHE(ULONG_MAX) |
565 | #undef CACHE |
566 | }; |
567 | EXPORT_SYMBOL(malloc_sizes); |
568 | |
569 | /* Must match cache_sizes above. Out of line to keep cache footprint low. */ |
570 | struct cache_names { |
571 | char *name; |
572 | char *name_dma; |
573 | }; |
574 | |
575 | static struct cache_names __initdata cache_names[] = { |
576 | #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" }, |
577 | #include <linux/kmalloc_sizes.h> |
578 | {NULL,} |
579 | #undef CACHE |
580 | }; |
581 | |
582 | static struct arraycache_init initarray_cache __initdata = |
583 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
584 | static struct arraycache_init initarray_generic = |
585 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
586 | |
587 | /* internal cache of cache description objs */ |
588 | static struct kmem_list3 *cache_cache_nodelists[MAX_NUMNODES]; |
589 | static struct kmem_cache cache_cache = { |
590 | .nodelists = cache_cache_nodelists, |
591 | .batchcount = 1, |
592 | .limit = BOOT_CPUCACHE_ENTRIES, |
593 | .shared = 1, |
594 | .size = sizeof(struct kmem_cache), |
595 | .name = "kmem_cache", |
596 | }; |
597 | |
598 | #define BAD_ALIEN_MAGIC 0x01020304ul |
599 | |
600 | #ifdef CONFIG_LOCKDEP |
601 | |
602 | /* |
603 | * Slab sometimes uses the kmalloc slabs to store the slab headers |
604 | * for other slabs "off slab". |
605 | * The locking for this is tricky in that it nests within the locks |
606 | * of all other slabs in a few places; to deal with this special |
607 | * locking we put on-slab caches into a separate lock-class. |
608 | * |
609 | * We set lock class for alien array caches which are up during init. |
610 | * The lock annotation will be lost if all cpus of a node goes down and |
611 | * then comes back up during hotplug |
612 | */ |
613 | static struct lock_class_key on_slab_l3_key; |
614 | static struct lock_class_key on_slab_alc_key; |
615 | |
616 | static struct lock_class_key debugobj_l3_key; |
617 | static struct lock_class_key debugobj_alc_key; |
618 | |
619 | static void slab_set_lock_classes(struct kmem_cache *cachep, |
620 | struct lock_class_key *l3_key, struct lock_class_key *alc_key, |
621 | int q) |
622 | { |
623 | struct array_cache **alc; |
624 | struct kmem_list3 *l3; |
625 | int r; |
626 | |
627 | l3 = cachep->nodelists[q]; |
628 | if (!l3) |
629 | return; |
630 | |
631 | lockdep_set_class(&l3->list_lock, l3_key); |
632 | alc = l3->alien; |
633 | /* |
634 | * FIXME: This check for BAD_ALIEN_MAGIC |
635 | * should go away when common slab code is taught to |
636 | * work even without alien caches. |
637 | * Currently, non NUMA code returns BAD_ALIEN_MAGIC |
638 | * for alloc_alien_cache, |
639 | */ |
640 | if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) |
641 | return; |
642 | for_each_node(r) { |
643 | if (alc[r]) |
644 | lockdep_set_class(&alc[r]->lock, alc_key); |
645 | } |
646 | } |
647 | |
648 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
649 | { |
650 | slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node); |
651 | } |
652 | |
653 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
654 | { |
655 | int node; |
656 | |
657 | for_each_online_node(node) |
658 | slab_set_debugobj_lock_classes_node(cachep, node); |
659 | } |
660 | |
661 | static void init_node_lock_keys(int q) |
662 | { |
663 | struct cache_sizes *s = malloc_sizes; |
664 | |
665 | if (slab_state < UP) |
666 | return; |
667 | |
668 | for (s = malloc_sizes; s->cs_size != ULONG_MAX; s++) { |
669 | struct kmem_list3 *l3; |
670 | |
671 | l3 = s->cs_cachep->nodelists[q]; |
672 | if (!l3 || OFF_SLAB(s->cs_cachep)) |
673 | continue; |
674 | |
675 | slab_set_lock_classes(s->cs_cachep, &on_slab_l3_key, |
676 | &on_slab_alc_key, q); |
677 | } |
678 | } |
679 | |
680 | static inline void init_lock_keys(void) |
681 | { |
682 | int node; |
683 | |
684 | for_each_node(node) |
685 | init_node_lock_keys(node); |
686 | } |
687 | #else |
688 | static void init_node_lock_keys(int q) |
689 | { |
690 | } |
691 | |
692 | static inline void init_lock_keys(void) |
693 | { |
694 | } |
695 | |
696 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
697 | { |
698 | } |
699 | |
700 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
701 | { |
702 | } |
703 | #endif |
704 | |
705 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); |
706 | |
707 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) |
708 | { |
709 | return cachep->array[smp_processor_id()]; |
710 | } |
711 | |
712 | static inline struct kmem_cache *__find_general_cachep(size_t size, |
713 | gfp_t gfpflags) |
714 | { |
715 | struct cache_sizes *csizep = malloc_sizes; |
716 | |
717 | #if DEBUG |
718 | /* This happens if someone tries to call |
719 | * kmem_cache_create(), or __kmalloc(), before |
720 | * the generic caches are initialized. |
721 | */ |
722 | BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); |
723 | #endif |
724 | if (!size) |
725 | return ZERO_SIZE_PTR; |
726 | |
727 | while (size > csizep->cs_size) |
728 | csizep++; |
729 | |
730 | /* |
731 | * Really subtle: The last entry with cs->cs_size==ULONG_MAX |
732 | * has cs_{dma,}cachep==NULL. Thus no special case |
733 | * for large kmalloc calls required. |
734 | */ |
735 | #ifdef CONFIG_ZONE_DMA |
736 | if (unlikely(gfpflags & GFP_DMA)) |
737 | return csizep->cs_dmacachep; |
738 | #endif |
739 | return csizep->cs_cachep; |
740 | } |
741 | |
742 | static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) |
743 | { |
744 | return __find_general_cachep(size, gfpflags); |
745 | } |
746 | |
747 | static size_t slab_mgmt_size(size_t nr_objs, size_t align) |
748 | { |
749 | return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); |
750 | } |
751 | |
752 | /* |
753 | * Calculate the number of objects and left-over bytes for a given buffer size. |
754 | */ |
755 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, |
756 | size_t align, int flags, size_t *left_over, |
757 | unsigned int *num) |
758 | { |
759 | int nr_objs; |
760 | size_t mgmt_size; |
761 | size_t slab_size = PAGE_SIZE << gfporder; |
762 | |
763 | /* |
764 | * The slab management structure can be either off the slab or |
765 | * on it. For the latter case, the memory allocated for a |
766 | * slab is used for: |
767 | * |
768 | * - The struct slab |
769 | * - One kmem_bufctl_t for each object |
770 | * - Padding to respect alignment of @align |
771 | * - @buffer_size bytes for each object |
772 | * |
773 | * If the slab management structure is off the slab, then the |
774 | * alignment will already be calculated into the size. Because |
775 | * the slabs are all pages aligned, the objects will be at the |
776 | * correct alignment when allocated. |
777 | */ |
778 | if (flags & CFLGS_OFF_SLAB) { |
779 | mgmt_size = 0; |
780 | nr_objs = slab_size / buffer_size; |
781 | |
782 | if (nr_objs > SLAB_LIMIT) |
783 | nr_objs = SLAB_LIMIT; |
784 | } else { |
785 | /* |
786 | * Ignore padding for the initial guess. The padding |
787 | * is at most @align-1 bytes, and @buffer_size is at |
788 | * least @align. In the worst case, this result will |
789 | * be one greater than the number of objects that fit |
790 | * into the memory allocation when taking the padding |
791 | * into account. |
792 | */ |
793 | nr_objs = (slab_size - sizeof(struct slab)) / |
794 | (buffer_size + sizeof(kmem_bufctl_t)); |
795 | |
796 | /* |
797 | * This calculated number will be either the right |
798 | * amount, or one greater than what we want. |
799 | */ |
800 | if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size |
801 | > slab_size) |
802 | nr_objs--; |
803 | |
804 | if (nr_objs > SLAB_LIMIT) |
805 | nr_objs = SLAB_LIMIT; |
806 | |
807 | mgmt_size = slab_mgmt_size(nr_objs, align); |
808 | } |
809 | *num = nr_objs; |
810 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; |
811 | } |
812 | |
813 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) |
814 | |
815 | static void __slab_error(const char *function, struct kmem_cache *cachep, |
816 | char *msg) |
817 | { |
818 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
819 | function, cachep->name, msg); |
820 | dump_stack(); |
821 | } |
822 | |
823 | /* |
824 | * By default on NUMA we use alien caches to stage the freeing of |
825 | * objects allocated from other nodes. This causes massive memory |
826 | * inefficiencies when using fake NUMA setup to split memory into a |
827 | * large number of small nodes, so it can be disabled on the command |
828 | * line |
829 | */ |
830 | |
831 | static int use_alien_caches __read_mostly = 1; |
832 | static int __init noaliencache_setup(char *s) |
833 | { |
834 | use_alien_caches = 0; |
835 | return 1; |
836 | } |
837 | __setup("noaliencache", noaliencache_setup); |
838 | |
839 | static int __init slab_max_order_setup(char *str) |
840 | { |
841 | get_option(&str, &slab_max_order); |
842 | slab_max_order = slab_max_order < 0 ? 0 : |
843 | min(slab_max_order, MAX_ORDER - 1); |
844 | slab_max_order_set = true; |
845 | |
846 | return 1; |
847 | } |
848 | __setup("slab_max_order=", slab_max_order_setup); |
849 | |
850 | #ifdef CONFIG_NUMA |
851 | /* |
852 | * Special reaping functions for NUMA systems called from cache_reap(). |
853 | * These take care of doing round robin flushing of alien caches (containing |
854 | * objects freed on different nodes from which they were allocated) and the |
855 | * flushing of remote pcps by calling drain_node_pages. |
856 | */ |
857 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); |
858 | |
859 | static void init_reap_node(int cpu) |
860 | { |
861 | int node; |
862 | |
863 | node = next_node(cpu_to_mem(cpu), node_online_map); |
864 | if (node == MAX_NUMNODES) |
865 | node = first_node(node_online_map); |
866 | |
867 | per_cpu(slab_reap_node, cpu) = node; |
868 | } |
869 | |
870 | static void next_reap_node(void) |
871 | { |
872 | int node = __this_cpu_read(slab_reap_node); |
873 | |
874 | node = next_node(node, node_online_map); |
875 | if (unlikely(node >= MAX_NUMNODES)) |
876 | node = first_node(node_online_map); |
877 | __this_cpu_write(slab_reap_node, node); |
878 | } |
879 | |
880 | #else |
881 | #define init_reap_node(cpu) do { } while (0) |
882 | #define next_reap_node(void) do { } while (0) |
883 | #endif |
884 | |
885 | /* |
886 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
887 | * via the workqueue/eventd. |
888 | * Add the CPU number into the expiration time to minimize the possibility of |
889 | * the CPUs getting into lockstep and contending for the global cache chain |
890 | * lock. |
891 | */ |
892 | static void __cpuinit start_cpu_timer(int cpu) |
893 | { |
894 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); |
895 | |
896 | /* |
897 | * When this gets called from do_initcalls via cpucache_init(), |
898 | * init_workqueues() has already run, so keventd will be setup |
899 | * at that time. |
900 | */ |
901 | if (keventd_up() && reap_work->work.func == NULL) { |
902 | init_reap_node(cpu); |
903 | INIT_DELAYED_WORK_DEFERRABLE(reap_work, cache_reap); |
904 | schedule_delayed_work_on(cpu, reap_work, |
905 | __round_jiffies_relative(HZ, cpu)); |
906 | } |
907 | } |
908 | |
909 | static struct array_cache *alloc_arraycache(int node, int entries, |
910 | int batchcount, gfp_t gfp) |
911 | { |
912 | int memsize = sizeof(void *) * entries + sizeof(struct array_cache); |
913 | struct array_cache *nc = NULL; |
914 | |
915 | nc = kmalloc_node(memsize, gfp, node); |
916 | /* |
917 | * The array_cache structures contain pointers to free object. |
918 | * However, when such objects are allocated or transferred to another |
919 | * cache the pointers are not cleared and they could be counted as |
920 | * valid references during a kmemleak scan. Therefore, kmemleak must |
921 | * not scan such objects. |
922 | */ |
923 | kmemleak_no_scan(nc); |
924 | if (nc) { |
925 | nc->avail = 0; |
926 | nc->limit = entries; |
927 | nc->batchcount = batchcount; |
928 | nc->touched = 0; |
929 | spin_lock_init(&nc->lock); |
930 | } |
931 | return nc; |
932 | } |
933 | |
934 | static inline bool is_slab_pfmemalloc(struct slab *slabp) |
935 | { |
936 | struct page *page = virt_to_page(slabp->s_mem); |
937 | |
938 | return PageSlabPfmemalloc(page); |
939 | } |
940 | |
941 | /* Clears pfmemalloc_active if no slabs have pfmalloc set */ |
942 | static void recheck_pfmemalloc_active(struct kmem_cache *cachep, |
943 | struct array_cache *ac) |
944 | { |
945 | struct kmem_list3 *l3 = cachep->nodelists[numa_mem_id()]; |
946 | struct slab *slabp; |
947 | unsigned long flags; |
948 | |
949 | if (!pfmemalloc_active) |
950 | return; |
951 | |
952 | spin_lock_irqsave(&l3->list_lock, flags); |
953 | list_for_each_entry(slabp, &l3->slabs_full, list) |
954 | if (is_slab_pfmemalloc(slabp)) |
955 | goto out; |
956 | |
957 | list_for_each_entry(slabp, &l3->slabs_partial, list) |
958 | if (is_slab_pfmemalloc(slabp)) |
959 | goto out; |
960 | |
961 | list_for_each_entry(slabp, &l3->slabs_free, list) |
962 | if (is_slab_pfmemalloc(slabp)) |
963 | goto out; |
964 | |
965 | pfmemalloc_active = false; |
966 | out: |
967 | spin_unlock_irqrestore(&l3->list_lock, flags); |
968 | } |
969 | |
970 | static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, |
971 | gfp_t flags, bool force_refill) |
972 | { |
973 | int i; |
974 | void *objp = ac->entry[--ac->avail]; |
975 | |
976 | /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ |
977 | if (unlikely(is_obj_pfmemalloc(objp))) { |
978 | struct kmem_list3 *l3; |
979 | |
980 | if (gfp_pfmemalloc_allowed(flags)) { |
981 | clear_obj_pfmemalloc(&objp); |
982 | return objp; |
983 | } |
984 | |
985 | /* The caller cannot use PFMEMALLOC objects, find another one */ |
986 | for (i = 1; i < ac->avail; i++) { |
987 | /* If a !PFMEMALLOC object is found, swap them */ |
988 | if (!is_obj_pfmemalloc(ac->entry[i])) { |
989 | objp = ac->entry[i]; |
990 | ac->entry[i] = ac->entry[ac->avail]; |
991 | ac->entry[ac->avail] = objp; |
992 | return objp; |
993 | } |
994 | } |
995 | |
996 | /* |
997 | * If there are empty slabs on the slabs_free list and we are |
998 | * being forced to refill the cache, mark this one !pfmemalloc. |
999 | */ |
1000 | l3 = cachep->nodelists[numa_mem_id()]; |
1001 | if (!list_empty(&l3->slabs_free) && force_refill) { |
1002 | struct slab *slabp = virt_to_slab(objp); |
1003 | ClearPageSlabPfmemalloc(virt_to_page(slabp->s_mem)); |
1004 | clear_obj_pfmemalloc(&objp); |
1005 | recheck_pfmemalloc_active(cachep, ac); |
1006 | return objp; |
1007 | } |
1008 | |
1009 | /* No !PFMEMALLOC objects available */ |
1010 | ac->avail++; |
1011 | objp = NULL; |
1012 | } |
1013 | |
1014 | return objp; |
1015 | } |
1016 | |
1017 | static inline void *ac_get_obj(struct kmem_cache *cachep, |
1018 | struct array_cache *ac, gfp_t flags, bool force_refill) |
1019 | { |
1020 | void *objp; |
1021 | |
1022 | if (unlikely(sk_memalloc_socks())) |
1023 | objp = __ac_get_obj(cachep, ac, flags, force_refill); |
1024 | else |
1025 | objp = ac->entry[--ac->avail]; |
1026 | |
1027 | return objp; |
1028 | } |
1029 | |
1030 | static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
1031 | void *objp) |
1032 | { |
1033 | if (unlikely(pfmemalloc_active)) { |
1034 | /* Some pfmemalloc slabs exist, check if this is one */ |
1035 | struct page *page = virt_to_page(objp); |
1036 | if (PageSlabPfmemalloc(page)) |
1037 | set_obj_pfmemalloc(&objp); |
1038 | } |
1039 | |
1040 | return objp; |
1041 | } |
1042 | |
1043 | static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, |
1044 | void *objp) |
1045 | { |
1046 | if (unlikely(sk_memalloc_socks())) |
1047 | objp = __ac_put_obj(cachep, ac, objp); |
1048 | |
1049 | ac->entry[ac->avail++] = objp; |
1050 | } |
1051 | |
1052 | /* |
1053 | * Transfer objects in one arraycache to another. |
1054 | * Locking must be handled by the caller. |
1055 | * |
1056 | * Return the number of entries transferred. |
1057 | */ |
1058 | static int transfer_objects(struct array_cache *to, |
1059 | struct array_cache *from, unsigned int max) |
1060 | { |
1061 | /* Figure out how many entries to transfer */ |
1062 | int nr = min3(from->avail, max, to->limit - to->avail); |
1063 | |
1064 | if (!nr) |
1065 | return 0; |
1066 | |
1067 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, |
1068 | sizeof(void *) *nr); |
1069 | |
1070 | from->avail -= nr; |
1071 | to->avail += nr; |
1072 | return nr; |
1073 | } |
1074 | |
1075 | #ifndef CONFIG_NUMA |
1076 | |
1077 | #define drain_alien_cache(cachep, alien) do { } while (0) |
1078 | #define reap_alien(cachep, l3) do { } while (0) |
1079 | |
1080 | static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
1081 | { |
1082 | return (struct array_cache **)BAD_ALIEN_MAGIC; |
1083 | } |
1084 | |
1085 | static inline void free_alien_cache(struct array_cache **ac_ptr) |
1086 | { |
1087 | } |
1088 | |
1089 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
1090 | { |
1091 | return 0; |
1092 | } |
1093 | |
1094 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, |
1095 | gfp_t flags) |
1096 | { |
1097 | return NULL; |
1098 | } |
1099 | |
1100 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, |
1101 | gfp_t flags, int nodeid) |
1102 | { |
1103 | return NULL; |
1104 | } |
1105 | |
1106 | #else /* CONFIG_NUMA */ |
1107 | |
1108 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); |
1109 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); |
1110 | |
1111 | static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
1112 | { |
1113 | struct array_cache **ac_ptr; |
1114 | int memsize = sizeof(void *) * nr_node_ids; |
1115 | int i; |
1116 | |
1117 | if (limit > 1) |
1118 | limit = 12; |
1119 | ac_ptr = kzalloc_node(memsize, gfp, node); |
1120 | if (ac_ptr) { |
1121 | for_each_node(i) { |
1122 | if (i == node || !node_online(i)) |
1123 | continue; |
1124 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); |
1125 | if (!ac_ptr[i]) { |
1126 | for (i--; i >= 0; i--) |
1127 | kfree(ac_ptr[i]); |
1128 | kfree(ac_ptr); |
1129 | return NULL; |
1130 | } |
1131 | } |
1132 | } |
1133 | return ac_ptr; |
1134 | } |
1135 | |
1136 | static void free_alien_cache(struct array_cache **ac_ptr) |
1137 | { |
1138 | int i; |
1139 | |
1140 | if (!ac_ptr) |
1141 | return; |
1142 | for_each_node(i) |
1143 | kfree(ac_ptr[i]); |
1144 | kfree(ac_ptr); |
1145 | } |
1146 | |
1147 | static void __drain_alien_cache(struct kmem_cache *cachep, |
1148 | struct array_cache *ac, int node) |
1149 | { |
1150 | struct kmem_list3 *rl3 = cachep->nodelists[node]; |
1151 | |
1152 | if (ac->avail) { |
1153 | spin_lock(&rl3->list_lock); |
1154 | /* |
1155 | * Stuff objects into the remote nodes shared array first. |
1156 | * That way we could avoid the overhead of putting the objects |
1157 | * into the free lists and getting them back later. |
1158 | */ |
1159 | if (rl3->shared) |
1160 | transfer_objects(rl3->shared, ac, ac->limit); |
1161 | |
1162 | free_block(cachep, ac->entry, ac->avail, node); |
1163 | ac->avail = 0; |
1164 | spin_unlock(&rl3->list_lock); |
1165 | } |
1166 | } |
1167 | |
1168 | /* |
1169 | * Called from cache_reap() to regularly drain alien caches round robin. |
1170 | */ |
1171 | static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) |
1172 | { |
1173 | int node = __this_cpu_read(slab_reap_node); |
1174 | |
1175 | if (l3->alien) { |
1176 | struct array_cache *ac = l3->alien[node]; |
1177 | |
1178 | if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { |
1179 | __drain_alien_cache(cachep, ac, node); |
1180 | spin_unlock_irq(&ac->lock); |
1181 | } |
1182 | } |
1183 | } |
1184 | |
1185 | static void drain_alien_cache(struct kmem_cache *cachep, |
1186 | struct array_cache **alien) |
1187 | { |
1188 | int i = 0; |
1189 | struct array_cache *ac; |
1190 | unsigned long flags; |
1191 | |
1192 | for_each_online_node(i) { |
1193 | ac = alien[i]; |
1194 | if (ac) { |
1195 | spin_lock_irqsave(&ac->lock, flags); |
1196 | __drain_alien_cache(cachep, ac, i); |
1197 | spin_unlock_irqrestore(&ac->lock, flags); |
1198 | } |
1199 | } |
1200 | } |
1201 | |
1202 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
1203 | { |
1204 | struct slab *slabp = virt_to_slab(objp); |
1205 | int nodeid = slabp->nodeid; |
1206 | struct kmem_list3 *l3; |
1207 | struct array_cache *alien = NULL; |
1208 | int node; |
1209 | |
1210 | node = numa_mem_id(); |
1211 | |
1212 | /* |
1213 | * Make sure we are not freeing a object from another node to the array |
1214 | * cache on this cpu. |
1215 | */ |
1216 | if (likely(slabp->nodeid == node)) |
1217 | return 0; |
1218 | |
1219 | l3 = cachep->nodelists[node]; |
1220 | STATS_INC_NODEFREES(cachep); |
1221 | if (l3->alien && l3->alien[nodeid]) { |
1222 | alien = l3->alien[nodeid]; |
1223 | spin_lock(&alien->lock); |
1224 | if (unlikely(alien->avail == alien->limit)) { |
1225 | STATS_INC_ACOVERFLOW(cachep); |
1226 | __drain_alien_cache(cachep, alien, nodeid); |
1227 | } |
1228 | ac_put_obj(cachep, alien, objp); |
1229 | spin_unlock(&alien->lock); |
1230 | } else { |
1231 | spin_lock(&(cachep->nodelists[nodeid])->list_lock); |
1232 | free_block(cachep, &objp, 1, nodeid); |
1233 | spin_unlock(&(cachep->nodelists[nodeid])->list_lock); |
1234 | } |
1235 | return 1; |
1236 | } |
1237 | #endif |
1238 | |
1239 | /* |
1240 | * Allocates and initializes nodelists for a node on each slab cache, used for |
1241 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_list3 |
1242 | * will be allocated off-node since memory is not yet online for the new node. |
1243 | * When hotplugging memory or a cpu, existing nodelists are not replaced if |
1244 | * already in use. |
1245 | * |
1246 | * Must hold slab_mutex. |
1247 | */ |
1248 | static int init_cache_nodelists_node(int node) |
1249 | { |
1250 | struct kmem_cache *cachep; |
1251 | struct kmem_list3 *l3; |
1252 | const int memsize = sizeof(struct kmem_list3); |
1253 | |
1254 | list_for_each_entry(cachep, &slab_caches, list) { |
1255 | /* |
1256 | * Set up the size64 kmemlist for cpu before we can |
1257 | * begin anything. Make sure some other cpu on this |
1258 | * node has not already allocated this |
1259 | */ |
1260 | if (!cachep->nodelists[node]) { |
1261 | l3 = kmalloc_node(memsize, GFP_KERNEL, node); |
1262 | if (!l3) |
1263 | return -ENOMEM; |
1264 | kmem_list3_init(l3); |
1265 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
1266 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1267 | |
1268 | /* |
1269 | * The l3s don't come and go as CPUs come and |
1270 | * go. slab_mutex is sufficient |
1271 | * protection here. |
1272 | */ |
1273 | cachep->nodelists[node] = l3; |
1274 | } |
1275 | |
1276 | spin_lock_irq(&cachep->nodelists[node]->list_lock); |
1277 | cachep->nodelists[node]->free_limit = |
1278 | (1 + nr_cpus_node(node)) * |
1279 | cachep->batchcount + cachep->num; |
1280 | spin_unlock_irq(&cachep->nodelists[node]->list_lock); |
1281 | } |
1282 | return 0; |
1283 | } |
1284 | |
1285 | static void __cpuinit cpuup_canceled(long cpu) |
1286 | { |
1287 | struct kmem_cache *cachep; |
1288 | struct kmem_list3 *l3 = NULL; |
1289 | int node = cpu_to_mem(cpu); |
1290 | const struct cpumask *mask = cpumask_of_node(node); |
1291 | |
1292 | list_for_each_entry(cachep, &slab_caches, list) { |
1293 | struct array_cache *nc; |
1294 | struct array_cache *shared; |
1295 | struct array_cache **alien; |
1296 | |
1297 | /* cpu is dead; no one can alloc from it. */ |
1298 | nc = cachep->array[cpu]; |
1299 | cachep->array[cpu] = NULL; |
1300 | l3 = cachep->nodelists[node]; |
1301 | |
1302 | if (!l3) |
1303 | goto free_array_cache; |
1304 | |
1305 | spin_lock_irq(&l3->list_lock); |
1306 | |
1307 | /* Free limit for this kmem_list3 */ |
1308 | l3->free_limit -= cachep->batchcount; |
1309 | if (nc) |
1310 | free_block(cachep, nc->entry, nc->avail, node); |
1311 | |
1312 | if (!cpumask_empty(mask)) { |
1313 | spin_unlock_irq(&l3->list_lock); |
1314 | goto free_array_cache; |
1315 | } |
1316 | |
1317 | shared = l3->shared; |
1318 | if (shared) { |
1319 | free_block(cachep, shared->entry, |
1320 | shared->avail, node); |
1321 | l3->shared = NULL; |
1322 | } |
1323 | |
1324 | alien = l3->alien; |
1325 | l3->alien = NULL; |
1326 | |
1327 | spin_unlock_irq(&l3->list_lock); |
1328 | |
1329 | kfree(shared); |
1330 | if (alien) { |
1331 | drain_alien_cache(cachep, alien); |
1332 | free_alien_cache(alien); |
1333 | } |
1334 | free_array_cache: |
1335 | kfree(nc); |
1336 | } |
1337 | /* |
1338 | * In the previous loop, all the objects were freed to |
1339 | * the respective cache's slabs, now we can go ahead and |
1340 | * shrink each nodelist to its limit. |
1341 | */ |
1342 | list_for_each_entry(cachep, &slab_caches, list) { |
1343 | l3 = cachep->nodelists[node]; |
1344 | if (!l3) |
1345 | continue; |
1346 | drain_freelist(cachep, l3, l3->free_objects); |
1347 | } |
1348 | } |
1349 | |
1350 | static int __cpuinit cpuup_prepare(long cpu) |
1351 | { |
1352 | struct kmem_cache *cachep; |
1353 | struct kmem_list3 *l3 = NULL; |
1354 | int node = cpu_to_mem(cpu); |
1355 | int err; |
1356 | |
1357 | /* |
1358 | * We need to do this right in the beginning since |
1359 | * alloc_arraycache's are going to use this list. |
1360 | * kmalloc_node allows us to add the slab to the right |
1361 | * kmem_list3 and not this cpu's kmem_list3 |
1362 | */ |
1363 | err = init_cache_nodelists_node(node); |
1364 | if (err < 0) |
1365 | goto bad; |
1366 | |
1367 | /* |
1368 | * Now we can go ahead with allocating the shared arrays and |
1369 | * array caches |
1370 | */ |
1371 | list_for_each_entry(cachep, &slab_caches, list) { |
1372 | struct array_cache *nc; |
1373 | struct array_cache *shared = NULL; |
1374 | struct array_cache **alien = NULL; |
1375 | |
1376 | nc = alloc_arraycache(node, cachep->limit, |
1377 | cachep->batchcount, GFP_KERNEL); |
1378 | if (!nc) |
1379 | goto bad; |
1380 | if (cachep->shared) { |
1381 | shared = alloc_arraycache(node, |
1382 | cachep->shared * cachep->batchcount, |
1383 | 0xbaadf00d, GFP_KERNEL); |
1384 | if (!shared) { |
1385 | kfree(nc); |
1386 | goto bad; |
1387 | } |
1388 | } |
1389 | if (use_alien_caches) { |
1390 | alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); |
1391 | if (!alien) { |
1392 | kfree(shared); |
1393 | kfree(nc); |
1394 | goto bad; |
1395 | } |
1396 | } |
1397 | cachep->array[cpu] = nc; |
1398 | l3 = cachep->nodelists[node]; |
1399 | BUG_ON(!l3); |
1400 | |
1401 | spin_lock_irq(&l3->list_lock); |
1402 | if (!l3->shared) { |
1403 | /* |
1404 | * We are serialised from CPU_DEAD or |
1405 | * CPU_UP_CANCELLED by the cpucontrol lock |
1406 | */ |
1407 | l3->shared = shared; |
1408 | shared = NULL; |
1409 | } |
1410 | #ifdef CONFIG_NUMA |
1411 | if (!l3->alien) { |
1412 | l3->alien = alien; |
1413 | alien = NULL; |
1414 | } |
1415 | #endif |
1416 | spin_unlock_irq(&l3->list_lock); |
1417 | kfree(shared); |
1418 | free_alien_cache(alien); |
1419 | if (cachep->flags & SLAB_DEBUG_OBJECTS) |
1420 | slab_set_debugobj_lock_classes_node(cachep, node); |
1421 | } |
1422 | init_node_lock_keys(node); |
1423 | |
1424 | return 0; |
1425 | bad: |
1426 | cpuup_canceled(cpu); |
1427 | return -ENOMEM; |
1428 | } |
1429 | |
1430 | static int __cpuinit cpuup_callback(struct notifier_block *nfb, |
1431 | unsigned long action, void *hcpu) |
1432 | { |
1433 | long cpu = (long)hcpu; |
1434 | int err = 0; |
1435 | |
1436 | switch (action) { |
1437 | case CPU_UP_PREPARE: |
1438 | case CPU_UP_PREPARE_FROZEN: |
1439 | mutex_lock(&slab_mutex); |
1440 | err = cpuup_prepare(cpu); |
1441 | mutex_unlock(&slab_mutex); |
1442 | break; |
1443 | case CPU_ONLINE: |
1444 | case CPU_ONLINE_FROZEN: |
1445 | start_cpu_timer(cpu); |
1446 | break; |
1447 | #ifdef CONFIG_HOTPLUG_CPU |
1448 | case CPU_DOWN_PREPARE: |
1449 | case CPU_DOWN_PREPARE_FROZEN: |
1450 | /* |
1451 | * Shutdown cache reaper. Note that the slab_mutex is |
1452 | * held so that if cache_reap() is invoked it cannot do |
1453 | * anything expensive but will only modify reap_work |
1454 | * and reschedule the timer. |
1455 | */ |
1456 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); |
1457 | /* Now the cache_reaper is guaranteed to be not running. */ |
1458 | per_cpu(slab_reap_work, cpu).work.func = NULL; |
1459 | break; |
1460 | case CPU_DOWN_FAILED: |
1461 | case CPU_DOWN_FAILED_FROZEN: |
1462 | start_cpu_timer(cpu); |
1463 | break; |
1464 | case CPU_DEAD: |
1465 | case CPU_DEAD_FROZEN: |
1466 | /* |
1467 | * Even if all the cpus of a node are down, we don't free the |
1468 | * kmem_list3 of any cache. This to avoid a race between |
1469 | * cpu_down, and a kmalloc allocation from another cpu for |
1470 | * memory from the node of the cpu going down. The list3 |
1471 | * structure is usually allocated from kmem_cache_create() and |
1472 | * gets destroyed at kmem_cache_destroy(). |
1473 | */ |
1474 | /* fall through */ |
1475 | #endif |
1476 | case CPU_UP_CANCELED: |
1477 | case CPU_UP_CANCELED_FROZEN: |
1478 | mutex_lock(&slab_mutex); |
1479 | cpuup_canceled(cpu); |
1480 | mutex_unlock(&slab_mutex); |
1481 | break; |
1482 | } |
1483 | return notifier_from_errno(err); |
1484 | } |
1485 | |
1486 | static struct notifier_block __cpuinitdata cpucache_notifier = { |
1487 | &cpuup_callback, NULL, 0 |
1488 | }; |
1489 | |
1490 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
1491 | /* |
1492 | * Drains freelist for a node on each slab cache, used for memory hot-remove. |
1493 | * Returns -EBUSY if all objects cannot be drained so that the node is not |
1494 | * removed. |
1495 | * |
1496 | * Must hold slab_mutex. |
1497 | */ |
1498 | static int __meminit drain_cache_nodelists_node(int node) |
1499 | { |
1500 | struct kmem_cache *cachep; |
1501 | int ret = 0; |
1502 | |
1503 | list_for_each_entry(cachep, &slab_caches, list) { |
1504 | struct kmem_list3 *l3; |
1505 | |
1506 | l3 = cachep->nodelists[node]; |
1507 | if (!l3) |
1508 | continue; |
1509 | |
1510 | drain_freelist(cachep, l3, l3->free_objects); |
1511 | |
1512 | if (!list_empty(&l3->slabs_full) || |
1513 | !list_empty(&l3->slabs_partial)) { |
1514 | ret = -EBUSY; |
1515 | break; |
1516 | } |
1517 | } |
1518 | return ret; |
1519 | } |
1520 | |
1521 | static int __meminit slab_memory_callback(struct notifier_block *self, |
1522 | unsigned long action, void *arg) |
1523 | { |
1524 | struct memory_notify *mnb = arg; |
1525 | int ret = 0; |
1526 | int nid; |
1527 | |
1528 | nid = mnb->status_change_nid; |
1529 | if (nid < 0) |
1530 | goto out; |
1531 | |
1532 | switch (action) { |
1533 | case MEM_GOING_ONLINE: |
1534 | mutex_lock(&slab_mutex); |
1535 | ret = init_cache_nodelists_node(nid); |
1536 | mutex_unlock(&slab_mutex); |
1537 | break; |
1538 | case MEM_GOING_OFFLINE: |
1539 | mutex_lock(&slab_mutex); |
1540 | ret = drain_cache_nodelists_node(nid); |
1541 | mutex_unlock(&slab_mutex); |
1542 | break; |
1543 | case MEM_ONLINE: |
1544 | case MEM_OFFLINE: |
1545 | case MEM_CANCEL_ONLINE: |
1546 | case MEM_CANCEL_OFFLINE: |
1547 | break; |
1548 | } |
1549 | out: |
1550 | return notifier_from_errno(ret); |
1551 | } |
1552 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ |
1553 | |
1554 | /* |
1555 | * swap the static kmem_list3 with kmalloced memory |
1556 | */ |
1557 | static void __init init_list(struct kmem_cache *cachep, struct kmem_list3 *list, |
1558 | int nodeid) |
1559 | { |
1560 | struct kmem_list3 *ptr; |
1561 | |
1562 | ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_NOWAIT, nodeid); |
1563 | BUG_ON(!ptr); |
1564 | |
1565 | memcpy(ptr, list, sizeof(struct kmem_list3)); |
1566 | /* |
1567 | * Do not assume that spinlocks can be initialized via memcpy: |
1568 | */ |
1569 | spin_lock_init(&ptr->list_lock); |
1570 | |
1571 | MAKE_ALL_LISTS(cachep, ptr, nodeid); |
1572 | cachep->nodelists[nodeid] = ptr; |
1573 | } |
1574 | |
1575 | /* |
1576 | * For setting up all the kmem_list3s for cache whose buffer_size is same as |
1577 | * size of kmem_list3. |
1578 | */ |
1579 | static void __init set_up_list3s(struct kmem_cache *cachep, int index) |
1580 | { |
1581 | int node; |
1582 | |
1583 | for_each_online_node(node) { |
1584 | cachep->nodelists[node] = &initkmem_list3[index + node]; |
1585 | cachep->nodelists[node]->next_reap = jiffies + |
1586 | REAPTIMEOUT_LIST3 + |
1587 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1588 | } |
1589 | } |
1590 | |
1591 | /* |
1592 | * Initialisation. Called after the page allocator have been initialised and |
1593 | * before smp_init(). |
1594 | */ |
1595 | void __init kmem_cache_init(void) |
1596 | { |
1597 | size_t left_over; |
1598 | struct cache_sizes *sizes; |
1599 | struct cache_names *names; |
1600 | int i; |
1601 | int order; |
1602 | int node; |
1603 | |
1604 | if (num_possible_nodes() == 1) |
1605 | use_alien_caches = 0; |
1606 | |
1607 | for (i = 0; i < NUM_INIT_LISTS; i++) { |
1608 | kmem_list3_init(&initkmem_list3[i]); |
1609 | if (i < MAX_NUMNODES) |
1610 | cache_cache.nodelists[i] = NULL; |
1611 | } |
1612 | set_up_list3s(&cache_cache, CACHE_CACHE); |
1613 | |
1614 | /* |
1615 | * Fragmentation resistance on low memory - only use bigger |
1616 | * page orders on machines with more than 32MB of memory if |
1617 | * not overridden on the command line. |
1618 | */ |
1619 | if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) |
1620 | slab_max_order = SLAB_MAX_ORDER_HI; |
1621 | |
1622 | /* Bootstrap is tricky, because several objects are allocated |
1623 | * from caches that do not exist yet: |
1624 | * 1) initialize the cache_cache cache: it contains the struct |
1625 | * kmem_cache structures of all caches, except cache_cache itself: |
1626 | * cache_cache is statically allocated. |
1627 | * Initially an __init data area is used for the head array and the |
1628 | * kmem_list3 structures, it's replaced with a kmalloc allocated |
1629 | * array at the end of the bootstrap. |
1630 | * 2) Create the first kmalloc cache. |
1631 | * The struct kmem_cache for the new cache is allocated normally. |
1632 | * An __init data area is used for the head array. |
1633 | * 3) Create the remaining kmalloc caches, with minimally sized |
1634 | * head arrays. |
1635 | * 4) Replace the __init data head arrays for cache_cache and the first |
1636 | * kmalloc cache with kmalloc allocated arrays. |
1637 | * 5) Replace the __init data for kmem_list3 for cache_cache and |
1638 | * the other cache's with kmalloc allocated memory. |
1639 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. |
1640 | */ |
1641 | |
1642 | node = numa_mem_id(); |
1643 | |
1644 | /* 1) create the cache_cache */ |
1645 | INIT_LIST_HEAD(&slab_caches); |
1646 | list_add(&cache_cache.list, &slab_caches); |
1647 | cache_cache.colour_off = cache_line_size(); |
1648 | cache_cache.array[smp_processor_id()] = &initarray_cache.cache; |
1649 | cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE + node]; |
1650 | |
1651 | /* |
1652 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids |
1653 | */ |
1654 | cache_cache.size = offsetof(struct kmem_cache, array[nr_cpu_ids]) + |
1655 | nr_node_ids * sizeof(struct kmem_list3 *); |
1656 | cache_cache.object_size = cache_cache.size; |
1657 | cache_cache.size = ALIGN(cache_cache.size, |
1658 | cache_line_size()); |
1659 | cache_cache.reciprocal_buffer_size = |
1660 | reciprocal_value(cache_cache.size); |
1661 | |
1662 | for (order = 0; order < MAX_ORDER; order++) { |
1663 | cache_estimate(order, cache_cache.size, |
1664 | cache_line_size(), 0, &left_over, &cache_cache.num); |
1665 | if (cache_cache.num) |
1666 | break; |
1667 | } |
1668 | BUG_ON(!cache_cache.num); |
1669 | cache_cache.gfporder = order; |
1670 | cache_cache.colour = left_over / cache_cache.colour_off; |
1671 | cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) + |
1672 | sizeof(struct slab), cache_line_size()); |
1673 | |
1674 | /* 2+3) create the kmalloc caches */ |
1675 | sizes = malloc_sizes; |
1676 | names = cache_names; |
1677 | |
1678 | /* |
1679 | * Initialize the caches that provide memory for the array cache and the |
1680 | * kmem_list3 structures first. Without this, further allocations will |
1681 | * bug. |
1682 | */ |
1683 | |
1684 | sizes[INDEX_AC].cs_cachep = __kmem_cache_create(names[INDEX_AC].name, |
1685 | sizes[INDEX_AC].cs_size, |
1686 | ARCH_KMALLOC_MINALIGN, |
1687 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, |
1688 | NULL); |
1689 | |
1690 | if (INDEX_AC != INDEX_L3) { |
1691 | sizes[INDEX_L3].cs_cachep = |
1692 | __kmem_cache_create(names[INDEX_L3].name, |
1693 | sizes[INDEX_L3].cs_size, |
1694 | ARCH_KMALLOC_MINALIGN, |
1695 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, |
1696 | NULL); |
1697 | } |
1698 | |
1699 | slab_early_init = 0; |
1700 | |
1701 | while (sizes->cs_size != ULONG_MAX) { |
1702 | /* |
1703 | * For performance, all the general caches are L1 aligned. |
1704 | * This should be particularly beneficial on SMP boxes, as it |
1705 | * eliminates "false sharing". |
1706 | * Note for systems short on memory removing the alignment will |
1707 | * allow tighter packing of the smaller caches. |
1708 | */ |
1709 | if (!sizes->cs_cachep) { |
1710 | sizes->cs_cachep = __kmem_cache_create(names->name, |
1711 | sizes->cs_size, |
1712 | ARCH_KMALLOC_MINALIGN, |
1713 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, |
1714 | NULL); |
1715 | } |
1716 | #ifdef CONFIG_ZONE_DMA |
1717 | sizes->cs_dmacachep = __kmem_cache_create( |
1718 | names->name_dma, |
1719 | sizes->cs_size, |
1720 | ARCH_KMALLOC_MINALIGN, |
1721 | ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA| |
1722 | SLAB_PANIC, |
1723 | NULL); |
1724 | #endif |
1725 | sizes++; |
1726 | names++; |
1727 | } |
1728 | /* 4) Replace the bootstrap head arrays */ |
1729 | { |
1730 | struct array_cache *ptr; |
1731 | |
1732 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1733 | |
1734 | BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); |
1735 | memcpy(ptr, cpu_cache_get(&cache_cache), |
1736 | sizeof(struct arraycache_init)); |
1737 | /* |
1738 | * Do not assume that spinlocks can be initialized via memcpy: |
1739 | */ |
1740 | spin_lock_init(&ptr->lock); |
1741 | |
1742 | cache_cache.array[smp_processor_id()] = ptr; |
1743 | |
1744 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1745 | |
1746 | BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep) |
1747 | != &initarray_generic.cache); |
1748 | memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), |
1749 | sizeof(struct arraycache_init)); |
1750 | /* |
1751 | * Do not assume that spinlocks can be initialized via memcpy: |
1752 | */ |
1753 | spin_lock_init(&ptr->lock); |
1754 | |
1755 | malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = |
1756 | ptr; |
1757 | } |
1758 | /* 5) Replace the bootstrap kmem_list3's */ |
1759 | { |
1760 | int nid; |
1761 | |
1762 | for_each_online_node(nid) { |
1763 | init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid); |
1764 | |
1765 | init_list(malloc_sizes[INDEX_AC].cs_cachep, |
1766 | &initkmem_list3[SIZE_AC + nid], nid); |
1767 | |
1768 | if (INDEX_AC != INDEX_L3) { |
1769 | init_list(malloc_sizes[INDEX_L3].cs_cachep, |
1770 | &initkmem_list3[SIZE_L3 + nid], nid); |
1771 | } |
1772 | } |
1773 | } |
1774 | |
1775 | slab_state = UP; |
1776 | } |
1777 | |
1778 | void __init kmem_cache_init_late(void) |
1779 | { |
1780 | struct kmem_cache *cachep; |
1781 | |
1782 | slab_state = UP; |
1783 | |
1784 | /* Annotate slab for lockdep -- annotate the malloc caches */ |
1785 | init_lock_keys(); |
1786 | |
1787 | /* 6) resize the head arrays to their final sizes */ |
1788 | mutex_lock(&slab_mutex); |
1789 | list_for_each_entry(cachep, &slab_caches, list) |
1790 | if (enable_cpucache(cachep, GFP_NOWAIT)) |
1791 | BUG(); |
1792 | mutex_unlock(&slab_mutex); |
1793 | |
1794 | /* Done! */ |
1795 | slab_state = FULL; |
1796 | |
1797 | /* |
1798 | * Register a cpu startup notifier callback that initializes |
1799 | * cpu_cache_get for all new cpus |
1800 | */ |
1801 | register_cpu_notifier(&cpucache_notifier); |
1802 | |
1803 | #ifdef CONFIG_NUMA |
1804 | /* |
1805 | * Register a memory hotplug callback that initializes and frees |
1806 | * nodelists. |
1807 | */ |
1808 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
1809 | #endif |
1810 | |
1811 | /* |
1812 | * The reap timers are started later, with a module init call: That part |
1813 | * of the kernel is not yet operational. |
1814 | */ |
1815 | } |
1816 | |
1817 | static int __init cpucache_init(void) |
1818 | { |
1819 | int cpu; |
1820 | |
1821 | /* |
1822 | * Register the timers that return unneeded pages to the page allocator |
1823 | */ |
1824 | for_each_online_cpu(cpu) |
1825 | start_cpu_timer(cpu); |
1826 | |
1827 | /* Done! */ |
1828 | slab_state = FULL; |
1829 | return 0; |
1830 | } |
1831 | __initcall(cpucache_init); |
1832 | |
1833 | static noinline void |
1834 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) |
1835 | { |
1836 | struct kmem_list3 *l3; |
1837 | struct slab *slabp; |
1838 | unsigned long flags; |
1839 | int node; |
1840 | |
1841 | printk(KERN_WARNING |
1842 | "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", |
1843 | nodeid, gfpflags); |
1844 | printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", |
1845 | cachep->name, cachep->size, cachep->gfporder); |
1846 | |
1847 | for_each_online_node(node) { |
1848 | unsigned long active_objs = 0, num_objs = 0, free_objects = 0; |
1849 | unsigned long active_slabs = 0, num_slabs = 0; |
1850 | |
1851 | l3 = cachep->nodelists[node]; |
1852 | if (!l3) |
1853 | continue; |
1854 | |
1855 | spin_lock_irqsave(&l3->list_lock, flags); |
1856 | list_for_each_entry(slabp, &l3->slabs_full, list) { |
1857 | active_objs += cachep->num; |
1858 | active_slabs++; |
1859 | } |
1860 | list_for_each_entry(slabp, &l3->slabs_partial, list) { |
1861 | active_objs += slabp->inuse; |
1862 | active_slabs++; |
1863 | } |
1864 | list_for_each_entry(slabp, &l3->slabs_free, list) |
1865 | num_slabs++; |
1866 | |
1867 | free_objects += l3->free_objects; |
1868 | spin_unlock_irqrestore(&l3->list_lock, flags); |
1869 | |
1870 | num_slabs += active_slabs; |
1871 | num_objs = num_slabs * cachep->num; |
1872 | printk(KERN_WARNING |
1873 | " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", |
1874 | node, active_slabs, num_slabs, active_objs, num_objs, |
1875 | free_objects); |
1876 | } |
1877 | } |
1878 | |
1879 | /* |
1880 | * Interface to system's page allocator. No need to hold the cache-lock. |
1881 | * |
1882 | * If we requested dmaable memory, we will get it. Even if we |
1883 | * did not request dmaable memory, we might get it, but that |
1884 | * would be relatively rare and ignorable. |
1885 | */ |
1886 | static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
1887 | { |
1888 | struct page *page; |
1889 | int nr_pages; |
1890 | int i; |
1891 | |
1892 | #ifndef CONFIG_MMU |
1893 | /* |
1894 | * Nommu uses slab's for process anonymous memory allocations, and thus |
1895 | * requires __GFP_COMP to properly refcount higher order allocations |
1896 | */ |
1897 | flags |= __GFP_COMP; |
1898 | #endif |
1899 | |
1900 | flags |= cachep->allocflags; |
1901 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1902 | flags |= __GFP_RECLAIMABLE; |
1903 | |
1904 | page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); |
1905 | if (!page) { |
1906 | if (!(flags & __GFP_NOWARN) && printk_ratelimit()) |
1907 | slab_out_of_memory(cachep, flags, nodeid); |
1908 | return NULL; |
1909 | } |
1910 | |
1911 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ |
1912 | if (unlikely(page->pfmemalloc)) |
1913 | pfmemalloc_active = true; |
1914 | |
1915 | nr_pages = (1 << cachep->gfporder); |
1916 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1917 | add_zone_page_state(page_zone(page), |
1918 | NR_SLAB_RECLAIMABLE, nr_pages); |
1919 | else |
1920 | add_zone_page_state(page_zone(page), |
1921 | NR_SLAB_UNRECLAIMABLE, nr_pages); |
1922 | for (i = 0; i < nr_pages; i++) { |
1923 | __SetPageSlab(page + i); |
1924 | |
1925 | if (page->pfmemalloc) |
1926 | SetPageSlabPfmemalloc(page + i); |
1927 | } |
1928 | |
1929 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { |
1930 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); |
1931 | |
1932 | if (cachep->ctor) |
1933 | kmemcheck_mark_uninitialized_pages(page, nr_pages); |
1934 | else |
1935 | kmemcheck_mark_unallocated_pages(page, nr_pages); |
1936 | } |
1937 | |
1938 | return page_address(page); |
1939 | } |
1940 | |
1941 | /* |
1942 | * Interface to system's page release. |
1943 | */ |
1944 | static void kmem_freepages(struct kmem_cache *cachep, void *addr) |
1945 | { |
1946 | unsigned long i = (1 << cachep->gfporder); |
1947 | struct page *page = virt_to_page(addr); |
1948 | const unsigned long nr_freed = i; |
1949 | |
1950 | kmemcheck_free_shadow(page, cachep->gfporder); |
1951 | |
1952 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1953 | sub_zone_page_state(page_zone(page), |
1954 | NR_SLAB_RECLAIMABLE, nr_freed); |
1955 | else |
1956 | sub_zone_page_state(page_zone(page), |
1957 | NR_SLAB_UNRECLAIMABLE, nr_freed); |
1958 | while (i--) { |
1959 | BUG_ON(!PageSlab(page)); |
1960 | __ClearPageSlabPfmemalloc(page); |
1961 | __ClearPageSlab(page); |
1962 | page++; |
1963 | } |
1964 | if (current->reclaim_state) |
1965 | current->reclaim_state->reclaimed_slab += nr_freed; |
1966 | free_pages((unsigned long)addr, cachep->gfporder); |
1967 | } |
1968 | |
1969 | static void kmem_rcu_free(struct rcu_head *head) |
1970 | { |
1971 | struct slab_rcu *slab_rcu = (struct slab_rcu *)head; |
1972 | struct kmem_cache *cachep = slab_rcu->cachep; |
1973 | |
1974 | kmem_freepages(cachep, slab_rcu->addr); |
1975 | if (OFF_SLAB(cachep)) |
1976 | kmem_cache_free(cachep->slabp_cache, slab_rcu); |
1977 | } |
1978 | |
1979 | #if DEBUG |
1980 | |
1981 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1982 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, |
1983 | unsigned long caller) |
1984 | { |
1985 | int size = cachep->object_size; |
1986 | |
1987 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; |
1988 | |
1989 | if (size < 5 * sizeof(unsigned long)) |
1990 | return; |
1991 | |
1992 | *addr++ = 0x12345678; |
1993 | *addr++ = caller; |
1994 | *addr++ = smp_processor_id(); |
1995 | size -= 3 * sizeof(unsigned long); |
1996 | { |
1997 | unsigned long *sptr = &caller; |
1998 | unsigned long svalue; |
1999 | |
2000 | while (!kstack_end(sptr)) { |
2001 | svalue = *sptr++; |
2002 | if (kernel_text_address(svalue)) { |
2003 | *addr++ = svalue; |
2004 | size -= sizeof(unsigned long); |
2005 | if (size <= sizeof(unsigned long)) |
2006 | break; |
2007 | } |
2008 | } |
2009 | |
2010 | } |
2011 | *addr++ = 0x87654321; |
2012 | } |
2013 | #endif |
2014 | |
2015 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) |
2016 | { |
2017 | int size = cachep->object_size; |
2018 | addr = &((char *)addr)[obj_offset(cachep)]; |
2019 | |
2020 | memset(addr, val, size); |
2021 | *(unsigned char *)(addr + size - 1) = POISON_END; |
2022 | } |
2023 | |
2024 | static void dump_line(char *data, int offset, int limit) |
2025 | { |
2026 | int i; |
2027 | unsigned char error = 0; |
2028 | int bad_count = 0; |
2029 | |
2030 | printk(KERN_ERR "%03x: ", offset); |
2031 | for (i = 0; i < limit; i++) { |
2032 | if (data[offset + i] != POISON_FREE) { |
2033 | error = data[offset + i]; |
2034 | bad_count++; |
2035 | } |
2036 | } |
2037 | print_hex_dump(KERN_CONT, "", 0, 16, 1, |
2038 | &data[offset], limit, 1); |
2039 | |
2040 | if (bad_count == 1) { |
2041 | error ^= POISON_FREE; |
2042 | if (!(error & (error - 1))) { |
2043 | printk(KERN_ERR "Single bit error detected. Probably " |
2044 | "bad RAM.\n"); |
2045 | #ifdef CONFIG_X86 |
2046 | printk(KERN_ERR "Run memtest86+ or a similar memory " |
2047 | "test tool.\n"); |
2048 | #else |
2049 | printk(KERN_ERR "Run a memory test tool.\n"); |
2050 | #endif |
2051 | } |
2052 | } |
2053 | } |
2054 | #endif |
2055 | |
2056 | #if DEBUG |
2057 | |
2058 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) |
2059 | { |
2060 | int i, size; |
2061 | char *realobj; |
2062 | |
2063 | if (cachep->flags & SLAB_RED_ZONE) { |
2064 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", |
2065 | *dbg_redzone1(cachep, objp), |
2066 | *dbg_redzone2(cachep, objp)); |
2067 | } |
2068 | |
2069 | if (cachep->flags & SLAB_STORE_USER) { |
2070 | printk(KERN_ERR "Last user: [<%p>]", |
2071 | *dbg_userword(cachep, objp)); |
2072 | print_symbol("(%s)", |
2073 | (unsigned long)*dbg_userword(cachep, objp)); |
2074 | printk("\n"); |
2075 | } |
2076 | realobj = (char *)objp + obj_offset(cachep); |
2077 | size = cachep->object_size; |
2078 | for (i = 0; i < size && lines; i += 16, lines--) { |
2079 | int limit; |
2080 | limit = 16; |
2081 | if (i + limit > size) |
2082 | limit = size - i; |
2083 | dump_line(realobj, i, limit); |
2084 | } |
2085 | } |
2086 | |
2087 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) |
2088 | { |
2089 | char *realobj; |
2090 | int size, i; |
2091 | int lines = 0; |
2092 | |
2093 | realobj = (char *)objp + obj_offset(cachep); |
2094 | size = cachep->object_size; |
2095 | |
2096 | for (i = 0; i < size; i++) { |
2097 | char exp = POISON_FREE; |
2098 | if (i == size - 1) |
2099 | exp = POISON_END; |
2100 | if (realobj[i] != exp) { |
2101 | int limit; |
2102 | /* Mismatch ! */ |
2103 | /* Print header */ |
2104 | if (lines == 0) { |
2105 | printk(KERN_ERR |
2106 | "Slab corruption (%s): %s start=%p, len=%d\n", |
2107 | print_tainted(), cachep->name, realobj, size); |
2108 | print_objinfo(cachep, objp, 0); |
2109 | } |
2110 | /* Hexdump the affected line */ |
2111 | i = (i / 16) * 16; |
2112 | limit = 16; |
2113 | if (i + limit > size) |
2114 | limit = size - i; |
2115 | dump_line(realobj, i, limit); |
2116 | i += 16; |
2117 | lines++; |
2118 | /* Limit to 5 lines */ |
2119 | if (lines > 5) |
2120 | break; |
2121 | } |
2122 | } |
2123 | if (lines != 0) { |
2124 | /* Print some data about the neighboring objects, if they |
2125 | * exist: |
2126 | */ |
2127 | struct slab *slabp = virt_to_slab(objp); |
2128 | unsigned int objnr; |
2129 | |
2130 | objnr = obj_to_index(cachep, slabp, objp); |
2131 | if (objnr) { |
2132 | objp = index_to_obj(cachep, slabp, objnr - 1); |
2133 | realobj = (char *)objp + obj_offset(cachep); |
2134 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
2135 | realobj, size); |
2136 | print_objinfo(cachep, objp, 2); |
2137 | } |
2138 | if (objnr + 1 < cachep->num) { |
2139 | objp = index_to_obj(cachep, slabp, objnr + 1); |
2140 | realobj = (char *)objp + obj_offset(cachep); |
2141 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
2142 | realobj, size); |
2143 | print_objinfo(cachep, objp, 2); |
2144 | } |
2145 | } |
2146 | } |
2147 | #endif |
2148 | |
2149 | #if DEBUG |
2150 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) |
2151 | { |
2152 | int i; |
2153 | for (i = 0; i < cachep->num; i++) { |
2154 | void *objp = index_to_obj(cachep, slabp, i); |
2155 | |
2156 | if (cachep->flags & SLAB_POISON) { |
2157 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2158 | if (cachep->size % PAGE_SIZE == 0 && |
2159 | OFF_SLAB(cachep)) |
2160 | kernel_map_pages(virt_to_page(objp), |
2161 | cachep->size / PAGE_SIZE, 1); |
2162 | else |
2163 | check_poison_obj(cachep, objp); |
2164 | #else |
2165 | check_poison_obj(cachep, objp); |
2166 | #endif |
2167 | } |
2168 | if (cachep->flags & SLAB_RED_ZONE) { |
2169 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2170 | slab_error(cachep, "start of a freed object " |
2171 | "was overwritten"); |
2172 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2173 | slab_error(cachep, "end of a freed object " |
2174 | "was overwritten"); |
2175 | } |
2176 | } |
2177 | } |
2178 | #else |
2179 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) |
2180 | { |
2181 | } |
2182 | #endif |
2183 | |
2184 | /** |
2185 | * slab_destroy - destroy and release all objects in a slab |
2186 | * @cachep: cache pointer being destroyed |
2187 | * @slabp: slab pointer being destroyed |
2188 | * |
2189 | * Destroy all the objs in a slab, and release the mem back to the system. |
2190 | * Before calling the slab must have been unlinked from the cache. The |
2191 | * cache-lock is not held/needed. |
2192 | */ |
2193 | static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) |
2194 | { |
2195 | void *addr = slabp->s_mem - slabp->colouroff; |
2196 | |
2197 | slab_destroy_debugcheck(cachep, slabp); |
2198 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { |
2199 | struct slab_rcu *slab_rcu; |
2200 | |
2201 | slab_rcu = (struct slab_rcu *)slabp; |
2202 | slab_rcu->cachep = cachep; |
2203 | slab_rcu->addr = addr; |
2204 | call_rcu(&slab_rcu->head, kmem_rcu_free); |
2205 | } else { |
2206 | kmem_freepages(cachep, addr); |
2207 | if (OFF_SLAB(cachep)) |
2208 | kmem_cache_free(cachep->slabp_cache, slabp); |
2209 | } |
2210 | } |
2211 | |
2212 | static void __kmem_cache_destroy(struct kmem_cache *cachep) |
2213 | { |
2214 | int i; |
2215 | struct kmem_list3 *l3; |
2216 | |
2217 | for_each_online_cpu(i) |
2218 | kfree(cachep->array[i]); |
2219 | |
2220 | /* NUMA: free the list3 structures */ |
2221 | for_each_online_node(i) { |
2222 | l3 = cachep->nodelists[i]; |
2223 | if (l3) { |
2224 | kfree(l3->shared); |
2225 | free_alien_cache(l3->alien); |
2226 | kfree(l3); |
2227 | } |
2228 | } |
2229 | kmem_cache_free(&cache_cache, cachep); |
2230 | } |
2231 | |
2232 | |
2233 | /** |
2234 | * calculate_slab_order - calculate size (page order) of slabs |
2235 | * @cachep: pointer to the cache that is being created |
2236 | * @size: size of objects to be created in this cache. |
2237 | * @align: required alignment for the objects. |
2238 | * @flags: slab allocation flags |
2239 | * |
2240 | * Also calculates the number of objects per slab. |
2241 | * |
2242 | * This could be made much more intelligent. For now, try to avoid using |
2243 | * high order pages for slabs. When the gfp() functions are more friendly |
2244 | * towards high-order requests, this should be changed. |
2245 | */ |
2246 | static size_t calculate_slab_order(struct kmem_cache *cachep, |
2247 | size_t size, size_t align, unsigned long flags) |
2248 | { |
2249 | unsigned long offslab_limit; |
2250 | size_t left_over = 0; |
2251 | int gfporder; |
2252 | |
2253 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { |
2254 | unsigned int num; |
2255 | size_t remainder; |
2256 | |
2257 | cache_estimate(gfporder, size, align, flags, &remainder, &num); |
2258 | if (!num) |
2259 | continue; |
2260 | |
2261 | if (flags & CFLGS_OFF_SLAB) { |
2262 | /* |
2263 | * Max number of objs-per-slab for caches which |
2264 | * use off-slab slabs. Needed to avoid a possible |
2265 | * looping condition in cache_grow(). |
2266 | */ |
2267 | offslab_limit = size - sizeof(struct slab); |
2268 | offslab_limit /= sizeof(kmem_bufctl_t); |
2269 | |
2270 | if (num > offslab_limit) |
2271 | break; |
2272 | } |
2273 | |
2274 | /* Found something acceptable - save it away */ |
2275 | cachep->num = num; |
2276 | cachep->gfporder = gfporder; |
2277 | left_over = remainder; |
2278 | |
2279 | /* |
2280 | * A VFS-reclaimable slab tends to have most allocations |
2281 | * as GFP_NOFS and we really don't want to have to be allocating |
2282 | * higher-order pages when we are unable to shrink dcache. |
2283 | */ |
2284 | if (flags & SLAB_RECLAIM_ACCOUNT) |
2285 | break; |
2286 | |
2287 | /* |
2288 | * Large number of objects is good, but very large slabs are |
2289 | * currently bad for the gfp()s. |
2290 | */ |
2291 | if (gfporder >= slab_max_order) |
2292 | break; |
2293 | |
2294 | /* |
2295 | * Acceptable internal fragmentation? |
2296 | */ |
2297 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) |
2298 | break; |
2299 | } |
2300 | return left_over; |
2301 | } |
2302 | |
2303 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) |
2304 | { |
2305 | if (slab_state >= FULL) |
2306 | return enable_cpucache(cachep, gfp); |
2307 | |
2308 | if (slab_state == DOWN) { |
2309 | /* |
2310 | * Note: the first kmem_cache_create must create the cache |
2311 | * that's used by kmalloc(24), otherwise the creation of |
2312 | * further caches will BUG(). |
2313 | */ |
2314 | cachep->array[smp_processor_id()] = &initarray_generic.cache; |
2315 | |
2316 | /* |
2317 | * If the cache that's used by kmalloc(sizeof(kmem_list3)) is |
2318 | * the first cache, then we need to set up all its list3s, |
2319 | * otherwise the creation of further caches will BUG(). |
2320 | */ |
2321 | set_up_list3s(cachep, SIZE_AC); |
2322 | if (INDEX_AC == INDEX_L3) |
2323 | slab_state = PARTIAL_L3; |
2324 | else |
2325 | slab_state = PARTIAL_ARRAYCACHE; |
2326 | } else { |
2327 | cachep->array[smp_processor_id()] = |
2328 | kmalloc(sizeof(struct arraycache_init), gfp); |
2329 | |
2330 | if (slab_state == PARTIAL_ARRAYCACHE) { |
2331 | set_up_list3s(cachep, SIZE_L3); |
2332 | slab_state = PARTIAL_L3; |
2333 | } else { |
2334 | int node; |
2335 | for_each_online_node(node) { |
2336 | cachep->nodelists[node] = |
2337 | kmalloc_node(sizeof(struct kmem_list3), |
2338 | gfp, node); |
2339 | BUG_ON(!cachep->nodelists[node]); |
2340 | kmem_list3_init(cachep->nodelists[node]); |
2341 | } |
2342 | } |
2343 | } |
2344 | cachep->nodelists[numa_mem_id()]->next_reap = |
2345 | jiffies + REAPTIMEOUT_LIST3 + |
2346 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
2347 | |
2348 | cpu_cache_get(cachep)->avail = 0; |
2349 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
2350 | cpu_cache_get(cachep)->batchcount = 1; |
2351 | cpu_cache_get(cachep)->touched = 0; |
2352 | cachep->batchcount = 1; |
2353 | cachep->limit = BOOT_CPUCACHE_ENTRIES; |
2354 | return 0; |
2355 | } |
2356 | |
2357 | /** |
2358 | * __kmem_cache_create - Create a cache. |
2359 | * @name: A string which is used in /proc/slabinfo to identify this cache. |
2360 | * @size: The size of objects to be created in this cache. |
2361 | * @align: The required alignment for the objects. |
2362 | * @flags: SLAB flags |
2363 | * @ctor: A constructor for the objects. |
2364 | * |
2365 | * Returns a ptr to the cache on success, NULL on failure. |
2366 | * Cannot be called within a int, but can be interrupted. |
2367 | * The @ctor is run when new pages are allocated by the cache. |
2368 | * |
2369 | * @name must be valid until the cache is destroyed. This implies that |
2370 | * the module calling this has to destroy the cache before getting unloaded. |
2371 | * |
2372 | * The flags are |
2373 | * |
2374 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
2375 | * to catch references to uninitialised memory. |
2376 | * |
2377 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
2378 | * for buffer overruns. |
2379 | * |
2380 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
2381 | * cacheline. This can be beneficial if you're counting cycles as closely |
2382 | * as davem. |
2383 | */ |
2384 | struct kmem_cache * |
2385 | __kmem_cache_create (const char *name, size_t size, size_t align, |
2386 | unsigned long flags, void (*ctor)(void *)) |
2387 | { |
2388 | size_t left_over, slab_size, ralign; |
2389 | struct kmem_cache *cachep = NULL; |
2390 | gfp_t gfp; |
2391 | |
2392 | #if DEBUG |
2393 | #if FORCED_DEBUG |
2394 | /* |
2395 | * Enable redzoning and last user accounting, except for caches with |
2396 | * large objects, if the increased size would increase the object size |
2397 | * above the next power of two: caches with object sizes just above a |
2398 | * power of two have a significant amount of internal fragmentation. |
2399 | */ |
2400 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + |
2401 | 2 * sizeof(unsigned long long))) |
2402 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; |
2403 | if (!(flags & SLAB_DESTROY_BY_RCU)) |
2404 | flags |= SLAB_POISON; |
2405 | #endif |
2406 | if (flags & SLAB_DESTROY_BY_RCU) |
2407 | BUG_ON(flags & SLAB_POISON); |
2408 | #endif |
2409 | /* |
2410 | * Always checks flags, a caller might be expecting debug support which |
2411 | * isn't available. |
2412 | */ |
2413 | BUG_ON(flags & ~CREATE_MASK); |
2414 | |
2415 | /* |
2416 | * Check that size is in terms of words. This is needed to avoid |
2417 | * unaligned accesses for some archs when redzoning is used, and makes |
2418 | * sure any on-slab bufctl's are also correctly aligned. |
2419 | */ |
2420 | if (size & (BYTES_PER_WORD - 1)) { |
2421 | size += (BYTES_PER_WORD - 1); |
2422 | size &= ~(BYTES_PER_WORD - 1); |
2423 | } |
2424 | |
2425 | /* calculate the final buffer alignment: */ |
2426 | |
2427 | /* 1) arch recommendation: can be overridden for debug */ |
2428 | if (flags & SLAB_HWCACHE_ALIGN) { |
2429 | /* |
2430 | * Default alignment: as specified by the arch code. Except if |
2431 | * an object is really small, then squeeze multiple objects into |
2432 | * one cacheline. |
2433 | */ |
2434 | ralign = cache_line_size(); |
2435 | while (size <= ralign / 2) |
2436 | ralign /= 2; |
2437 | } else { |
2438 | ralign = BYTES_PER_WORD; |
2439 | } |
2440 | |
2441 | /* |
2442 | * Redzoning and user store require word alignment or possibly larger. |
2443 | * Note this will be overridden by architecture or caller mandated |
2444 | * alignment if either is greater than BYTES_PER_WORD. |
2445 | */ |
2446 | if (flags & SLAB_STORE_USER) |
2447 | ralign = BYTES_PER_WORD; |
2448 | |
2449 | if (flags & SLAB_RED_ZONE) { |
2450 | ralign = REDZONE_ALIGN; |
2451 | /* If redzoning, ensure that the second redzone is suitably |
2452 | * aligned, by adjusting the object size accordingly. */ |
2453 | size += REDZONE_ALIGN - 1; |
2454 | size &= ~(REDZONE_ALIGN - 1); |
2455 | } |
2456 | |
2457 | /* 2) arch mandated alignment */ |
2458 | if (ralign < ARCH_SLAB_MINALIGN) { |
2459 | ralign = ARCH_SLAB_MINALIGN; |
2460 | } |
2461 | /* 3) caller mandated alignment */ |
2462 | if (ralign < align) { |
2463 | ralign = align; |
2464 | } |
2465 | /* disable debug if necessary */ |
2466 | if (ralign > __alignof__(unsigned long long)) |
2467 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2468 | /* |
2469 | * 4) Store it. |
2470 | */ |
2471 | align = ralign; |
2472 | |
2473 | if (slab_is_available()) |
2474 | gfp = GFP_KERNEL; |
2475 | else |
2476 | gfp = GFP_NOWAIT; |
2477 | |
2478 | /* Get cache's description obj. */ |
2479 | cachep = kmem_cache_zalloc(&cache_cache, gfp); |
2480 | if (!cachep) |
2481 | return NULL; |
2482 | |
2483 | cachep->nodelists = (struct kmem_list3 **)&cachep->array[nr_cpu_ids]; |
2484 | cachep->object_size = size; |
2485 | cachep->align = align; |
2486 | #if DEBUG |
2487 | |
2488 | /* |
2489 | * Both debugging options require word-alignment which is calculated |
2490 | * into align above. |
2491 | */ |
2492 | if (flags & SLAB_RED_ZONE) { |
2493 | /* add space for red zone words */ |
2494 | cachep->obj_offset += sizeof(unsigned long long); |
2495 | size += 2 * sizeof(unsigned long long); |
2496 | } |
2497 | if (flags & SLAB_STORE_USER) { |
2498 | /* user store requires one word storage behind the end of |
2499 | * the real object. But if the second red zone needs to be |
2500 | * aligned to 64 bits, we must allow that much space. |
2501 | */ |
2502 | if (flags & SLAB_RED_ZONE) |
2503 | size += REDZONE_ALIGN; |
2504 | else |
2505 | size += BYTES_PER_WORD; |
2506 | } |
2507 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
2508 | if (size >= malloc_sizes[INDEX_L3 + 1].cs_size |
2509 | && cachep->object_size > cache_line_size() && ALIGN(size, align) < PAGE_SIZE) { |
2510 | cachep->obj_offset += PAGE_SIZE - ALIGN(size, align); |
2511 | size = PAGE_SIZE; |
2512 | } |
2513 | #endif |
2514 | #endif |
2515 | |
2516 | /* |
2517 | * Determine if the slab management is 'on' or 'off' slab. |
2518 | * (bootstrapping cannot cope with offslab caches so don't do |
2519 | * it too early on. Always use on-slab management when |
2520 | * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) |
2521 | */ |
2522 | if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && |
2523 | !(flags & SLAB_NOLEAKTRACE)) |
2524 | /* |
2525 | * Size is large, assume best to place the slab management obj |
2526 | * off-slab (should allow better packing of objs). |
2527 | */ |
2528 | flags |= CFLGS_OFF_SLAB; |
2529 | |
2530 | size = ALIGN(size, align); |
2531 | |
2532 | left_over = calculate_slab_order(cachep, size, align, flags); |
2533 | |
2534 | if (!cachep->num) { |
2535 | printk(KERN_ERR |
2536 | "kmem_cache_create: couldn't create cache %s.\n", name); |
2537 | kmem_cache_free(&cache_cache, cachep); |
2538 | return NULL; |
2539 | } |
2540 | slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) |
2541 | + sizeof(struct slab), align); |
2542 | |
2543 | /* |
2544 | * If the slab has been placed off-slab, and we have enough space then |
2545 | * move it on-slab. This is at the expense of any extra colouring. |
2546 | */ |
2547 | if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { |
2548 | flags &= ~CFLGS_OFF_SLAB; |
2549 | left_over -= slab_size; |
2550 | } |
2551 | |
2552 | if (flags & CFLGS_OFF_SLAB) { |
2553 | /* really off slab. No need for manual alignment */ |
2554 | slab_size = |
2555 | cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); |
2556 | |
2557 | #ifdef CONFIG_PAGE_POISONING |
2558 | /* If we're going to use the generic kernel_map_pages() |
2559 | * poisoning, then it's going to smash the contents of |
2560 | * the redzone and userword anyhow, so switch them off. |
2561 | */ |
2562 | if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) |
2563 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2564 | #endif |
2565 | } |
2566 | |
2567 | cachep->colour_off = cache_line_size(); |
2568 | /* Offset must be a multiple of the alignment. */ |
2569 | if (cachep->colour_off < align) |
2570 | cachep->colour_off = align; |
2571 | cachep->colour = left_over / cachep->colour_off; |
2572 | cachep->slab_size = slab_size; |
2573 | cachep->flags = flags; |
2574 | cachep->allocflags = 0; |
2575 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) |
2576 | cachep->allocflags |= GFP_DMA; |
2577 | cachep->size = size; |
2578 | cachep->reciprocal_buffer_size = reciprocal_value(size); |
2579 | |
2580 | if (flags & CFLGS_OFF_SLAB) { |
2581 | cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); |
2582 | /* |
2583 | * This is a possibility for one of the malloc_sizes caches. |
2584 | * But since we go off slab only for object size greater than |
2585 | * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, |
2586 | * this should not happen at all. |
2587 | * But leave a BUG_ON for some lucky dude. |
2588 | */ |
2589 | BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); |
2590 | } |
2591 | cachep->ctor = ctor; |
2592 | cachep->name = name; |
2593 | |
2594 | if (setup_cpu_cache(cachep, gfp)) { |
2595 | __kmem_cache_destroy(cachep); |
2596 | return NULL; |
2597 | } |
2598 | |
2599 | if (flags & SLAB_DEBUG_OBJECTS) { |
2600 | /* |
2601 | * Would deadlock through slab_destroy()->call_rcu()-> |
2602 | * debug_object_activate()->kmem_cache_alloc(). |
2603 | */ |
2604 | WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU); |
2605 | |
2606 | slab_set_debugobj_lock_classes(cachep); |
2607 | } |
2608 | |
2609 | /* cache setup completed, link it into the list */ |
2610 | list_add(&cachep->list, &slab_caches); |
2611 | return cachep; |
2612 | } |
2613 | |
2614 | #if DEBUG |
2615 | static void check_irq_off(void) |
2616 | { |
2617 | BUG_ON(!irqs_disabled()); |
2618 | } |
2619 | |
2620 | static void check_irq_on(void) |
2621 | { |
2622 | BUG_ON(irqs_disabled()); |
2623 | } |
2624 | |
2625 | static void check_spinlock_acquired(struct kmem_cache *cachep) |
2626 | { |
2627 | #ifdef CONFIG_SMP |
2628 | check_irq_off(); |
2629 | assert_spin_locked(&cachep->nodelists[numa_mem_id()]->list_lock); |
2630 | #endif |
2631 | } |
2632 | |
2633 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) |
2634 | { |
2635 | #ifdef CONFIG_SMP |
2636 | check_irq_off(); |
2637 | assert_spin_locked(&cachep->nodelists[node]->list_lock); |
2638 | #endif |
2639 | } |
2640 | |
2641 | #else |
2642 | #define check_irq_off() do { } while(0) |
2643 | #define check_irq_on() do { } while(0) |
2644 | #define check_spinlock_acquired(x) do { } while(0) |
2645 | #define check_spinlock_acquired_node(x, y) do { } while(0) |
2646 | #endif |
2647 | |
2648 | static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, |
2649 | struct array_cache *ac, |
2650 | int force, int node); |
2651 | |
2652 | static void do_drain(void *arg) |
2653 | { |
2654 | struct kmem_cache *cachep = arg; |
2655 | struct array_cache *ac; |
2656 | int node = numa_mem_id(); |
2657 | |
2658 | check_irq_off(); |
2659 | ac = cpu_cache_get(cachep); |
2660 | spin_lock(&cachep->nodelists[node]->list_lock); |
2661 | free_block(cachep, ac->entry, ac->avail, node); |
2662 | spin_unlock(&cachep->nodelists[node]->list_lock); |
2663 | ac->avail = 0; |
2664 | } |
2665 | |
2666 | static void drain_cpu_caches(struct kmem_cache *cachep) |
2667 | { |
2668 | struct kmem_list3 *l3; |
2669 | int node; |
2670 | |
2671 | on_each_cpu(do_drain, cachep, 1); |
2672 | check_irq_on(); |
2673 | for_each_online_node(node) { |
2674 | l3 = cachep->nodelists[node]; |
2675 | if (l3 && l3->alien) |
2676 | drain_alien_cache(cachep, l3->alien); |
2677 | } |
2678 | |
2679 | for_each_online_node(node) { |
2680 | l3 = cachep->nodelists[node]; |
2681 | if (l3) |
2682 | drain_array(cachep, l3, l3->shared, 1, node); |
2683 | } |
2684 | } |
2685 | |
2686 | /* |
2687 | * Remove slabs from the list of free slabs. |
2688 | * Specify the number of slabs to drain in tofree. |
2689 | * |
2690 | * Returns the actual number of slabs released. |
2691 | */ |
2692 | static int drain_freelist(struct kmem_cache *cache, |
2693 | struct kmem_list3 *l3, int tofree) |
2694 | { |
2695 | struct list_head *p; |
2696 | int nr_freed; |
2697 | struct slab *slabp; |
2698 | |
2699 | nr_freed = 0; |
2700 | while (nr_freed < tofree && !list_empty(&l3->slabs_free)) { |
2701 | |
2702 | spin_lock_irq(&l3->list_lock); |
2703 | p = l3->slabs_free.prev; |
2704 | if (p == &l3->slabs_free) { |
2705 | spin_unlock_irq(&l3->list_lock); |
2706 | goto out; |
2707 | } |
2708 | |
2709 | slabp = list_entry(p, struct slab, list); |
2710 | #if DEBUG |
2711 | BUG_ON(slabp->inuse); |
2712 | #endif |
2713 | list_del(&slabp->list); |
2714 | /* |
2715 | * Safe to drop the lock. The slab is no longer linked |
2716 | * to the cache. |
2717 | */ |
2718 | l3->free_objects -= cache->num; |
2719 | spin_unlock_irq(&l3->list_lock); |
2720 | slab_destroy(cache, slabp); |
2721 | nr_freed++; |
2722 | } |
2723 | out: |
2724 | return nr_freed; |
2725 | } |
2726 | |
2727 | /* Called with slab_mutex held to protect against cpu hotplug */ |
2728 | static int __cache_shrink(struct kmem_cache *cachep) |
2729 | { |
2730 | int ret = 0, i = 0; |
2731 | struct kmem_list3 *l3; |
2732 | |
2733 | drain_cpu_caches(cachep); |
2734 | |
2735 | check_irq_on(); |
2736 | for_each_online_node(i) { |
2737 | l3 = cachep->nodelists[i]; |
2738 | if (!l3) |
2739 | continue; |
2740 | |
2741 | drain_freelist(cachep, l3, l3->free_objects); |
2742 | |
2743 | ret += !list_empty(&l3->slabs_full) || |
2744 | !list_empty(&l3->slabs_partial); |
2745 | } |
2746 | return (ret ? 1 : 0); |
2747 | } |
2748 | |
2749 | /** |
2750 | * kmem_cache_shrink - Shrink a cache. |
2751 | * @cachep: The cache to shrink. |
2752 | * |
2753 | * Releases as many slabs as possible for a cache. |
2754 | * To help debugging, a zero exit status indicates all slabs were released. |
2755 | */ |
2756 | int kmem_cache_shrink(struct kmem_cache *cachep) |
2757 | { |
2758 | int ret; |
2759 | BUG_ON(!cachep || in_interrupt()); |
2760 | |
2761 | get_online_cpus(); |
2762 | mutex_lock(&slab_mutex); |
2763 | ret = __cache_shrink(cachep); |
2764 | mutex_unlock(&slab_mutex); |
2765 | put_online_cpus(); |
2766 | return ret; |
2767 | } |
2768 | EXPORT_SYMBOL(kmem_cache_shrink); |
2769 | |
2770 | /** |
2771 | * kmem_cache_destroy - delete a cache |
2772 | * @cachep: the cache to destroy |
2773 | * |
2774 | * Remove a &struct kmem_cache object from the slab cache. |
2775 | * |
2776 | * It is expected this function will be called by a module when it is |
2777 | * unloaded. This will remove the cache completely, and avoid a duplicate |
2778 | * cache being allocated each time a module is loaded and unloaded, if the |
2779 | * module doesn't have persistent in-kernel storage across loads and unloads. |
2780 | * |
2781 | * The cache must be empty before calling this function. |
2782 | * |
2783 | * The caller must guarantee that no one will allocate memory from the cache |
2784 | * during the kmem_cache_destroy(). |
2785 | */ |
2786 | void kmem_cache_destroy(struct kmem_cache *cachep) |
2787 | { |
2788 | BUG_ON(!cachep || in_interrupt()); |
2789 | |
2790 | /* Find the cache in the chain of caches. */ |
2791 | get_online_cpus(); |
2792 | mutex_lock(&slab_mutex); |
2793 | /* |
2794 | * the chain is never empty, cache_cache is never destroyed |
2795 | */ |
2796 | list_del(&cachep->list); |
2797 | if (__cache_shrink(cachep)) { |
2798 | slab_error(cachep, "Can't free all objects"); |
2799 | list_add(&cachep->list, &slab_caches); |
2800 | mutex_unlock(&slab_mutex); |
2801 | put_online_cpus(); |
2802 | return; |
2803 | } |
2804 | |
2805 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) |
2806 | rcu_barrier(); |
2807 | |
2808 | __kmem_cache_destroy(cachep); |
2809 | mutex_unlock(&slab_mutex); |
2810 | put_online_cpus(); |
2811 | } |
2812 | EXPORT_SYMBOL(kmem_cache_destroy); |
2813 | |
2814 | /* |
2815 | * Get the memory for a slab management obj. |
2816 | * For a slab cache when the slab descriptor is off-slab, slab descriptors |
2817 | * always come from malloc_sizes caches. The slab descriptor cannot |
2818 | * come from the same cache which is getting created because, |
2819 | * when we are searching for an appropriate cache for these |
2820 | * descriptors in kmem_cache_create, we search through the malloc_sizes array. |
2821 | * If we are creating a malloc_sizes cache here it would not be visible to |
2822 | * kmem_find_general_cachep till the initialization is complete. |
2823 | * Hence we cannot have slabp_cache same as the original cache. |
2824 | */ |
2825 | static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, |
2826 | int colour_off, gfp_t local_flags, |
2827 | int nodeid) |
2828 | { |
2829 | struct slab *slabp; |
2830 | |
2831 | if (OFF_SLAB(cachep)) { |
2832 | /* Slab management obj is off-slab. */ |
2833 | slabp = kmem_cache_alloc_node(cachep->slabp_cache, |
2834 | local_flags, nodeid); |
2835 | /* |
2836 | * If the first object in the slab is leaked (it's allocated |
2837 | * but no one has a reference to it), we want to make sure |
2838 | * kmemleak does not treat the ->s_mem pointer as a reference |
2839 | * to the object. Otherwise we will not report the leak. |
2840 | */ |
2841 | kmemleak_scan_area(&slabp->list, sizeof(struct list_head), |
2842 | local_flags); |
2843 | if (!slabp) |
2844 | return NULL; |
2845 | } else { |
2846 | slabp = objp + colour_off; |
2847 | colour_off += cachep->slab_size; |
2848 | } |
2849 | slabp->inuse = 0; |
2850 | slabp->colouroff = colour_off; |
2851 | slabp->s_mem = objp + colour_off; |
2852 | slabp->nodeid = nodeid; |
2853 | slabp->free = 0; |
2854 | return slabp; |
2855 | } |
2856 | |
2857 | static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) |
2858 | { |
2859 | return (kmem_bufctl_t *) (slabp + 1); |
2860 | } |
2861 | |
2862 | static void cache_init_objs(struct kmem_cache *cachep, |
2863 | struct slab *slabp) |
2864 | { |
2865 | int i; |
2866 | |
2867 | for (i = 0; i < cachep->num; i++) { |
2868 | void *objp = index_to_obj(cachep, slabp, i); |
2869 | #if DEBUG |
2870 | /* need to poison the objs? */ |
2871 | if (cachep->flags & SLAB_POISON) |
2872 | poison_obj(cachep, objp, POISON_FREE); |
2873 | if (cachep->flags & SLAB_STORE_USER) |
2874 | *dbg_userword(cachep, objp) = NULL; |
2875 | |
2876 | if (cachep->flags & SLAB_RED_ZONE) { |
2877 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2878 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2879 | } |
2880 | /* |
2881 | * Constructors are not allowed to allocate memory from the same |
2882 | * cache which they are a constructor for. Otherwise, deadlock. |
2883 | * They must also be threaded. |
2884 | */ |
2885 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) |
2886 | cachep->ctor(objp + obj_offset(cachep)); |
2887 | |
2888 | if (cachep->flags & SLAB_RED_ZONE) { |
2889 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2890 | slab_error(cachep, "constructor overwrote the" |
2891 | " end of an object"); |
2892 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2893 | slab_error(cachep, "constructor overwrote the" |
2894 | " start of an object"); |
2895 | } |
2896 | if ((cachep->size % PAGE_SIZE) == 0 && |
2897 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
2898 | kernel_map_pages(virt_to_page(objp), |
2899 | cachep->size / PAGE_SIZE, 0); |
2900 | #else |
2901 | if (cachep->ctor) |
2902 | cachep->ctor(objp); |
2903 | #endif |
2904 | slab_bufctl(slabp)[i] = i + 1; |
2905 | } |
2906 | slab_bufctl(slabp)[i - 1] = BUFCTL_END; |
2907 | } |
2908 | |
2909 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) |
2910 | { |
2911 | if (CONFIG_ZONE_DMA_FLAG) { |
2912 | if (flags & GFP_DMA) |
2913 | BUG_ON(!(cachep->allocflags & GFP_DMA)); |
2914 | else |
2915 | BUG_ON(cachep->allocflags & GFP_DMA); |
2916 | } |
2917 | } |
2918 | |
2919 | static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, |
2920 | int nodeid) |
2921 | { |
2922 | void *objp = index_to_obj(cachep, slabp, slabp->free); |
2923 | kmem_bufctl_t next; |
2924 | |
2925 | slabp->inuse++; |
2926 | next = slab_bufctl(slabp)[slabp->free]; |
2927 | #if DEBUG |
2928 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; |
2929 | WARN_ON(slabp->nodeid != nodeid); |
2930 | #endif |
2931 | slabp->free = next; |
2932 | |
2933 | return objp; |
2934 | } |
2935 | |
2936 | static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, |
2937 | void *objp, int nodeid) |
2938 | { |
2939 | unsigned int objnr = obj_to_index(cachep, slabp, objp); |
2940 | |
2941 | #if DEBUG |
2942 | /* Verify that the slab belongs to the intended node */ |
2943 | WARN_ON(slabp->nodeid != nodeid); |
2944 | |
2945 | if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { |
2946 | printk(KERN_ERR "slab: double free detected in cache " |
2947 | "'%s', objp %p\n", cachep->name, objp); |
2948 | BUG(); |
2949 | } |
2950 | #endif |
2951 | slab_bufctl(slabp)[objnr] = slabp->free; |
2952 | slabp->free = objnr; |
2953 | slabp->inuse--; |
2954 | } |
2955 | |
2956 | /* |
2957 | * Map pages beginning at addr to the given cache and slab. This is required |
2958 | * for the slab allocator to be able to lookup the cache and slab of a |
2959 | * virtual address for kfree, ksize, and slab debugging. |
2960 | */ |
2961 | static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, |
2962 | void *addr) |
2963 | { |
2964 | int nr_pages; |
2965 | struct page *page; |
2966 | |
2967 | page = virt_to_page(addr); |
2968 | |
2969 | nr_pages = 1; |
2970 | if (likely(!PageCompound(page))) |
2971 | nr_pages <<= cache->gfporder; |
2972 | |
2973 | do { |
2974 | page->slab_cache = cache; |
2975 | page->slab_page = slab; |
2976 | page++; |
2977 | } while (--nr_pages); |
2978 | } |
2979 | |
2980 | /* |
2981 | * Grow (by 1) the number of slabs within a cache. This is called by |
2982 | * kmem_cache_alloc() when there are no active objs left in a cache. |
2983 | */ |
2984 | static int cache_grow(struct kmem_cache *cachep, |
2985 | gfp_t flags, int nodeid, void *objp) |
2986 | { |
2987 | struct slab *slabp; |
2988 | size_t offset; |
2989 | gfp_t local_flags; |
2990 | struct kmem_list3 *l3; |
2991 | |
2992 | /* |
2993 | * Be lazy and only check for valid flags here, keeping it out of the |
2994 | * critical path in kmem_cache_alloc(). |
2995 | */ |
2996 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
2997 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
2998 | |
2999 | /* Take the l3 list lock to change the colour_next on this node */ |
3000 | check_irq_off(); |
3001 | l3 = cachep->nodelists[nodeid]; |
3002 | spin_lock(&l3->list_lock); |
3003 | |
3004 | /* Get colour for the slab, and cal the next value. */ |
3005 | offset = l3->colour_next; |
3006 | l3->colour_next++; |
3007 | if (l3->colour_next >= cachep->colour) |
3008 | l3->colour_next = 0; |
3009 | spin_unlock(&l3->list_lock); |
3010 | |
3011 | offset *= cachep->colour_off; |
3012 | |
3013 | if (local_flags & __GFP_WAIT) |
3014 | local_irq_enable(); |
3015 | |
3016 | /* |
3017 | * The test for missing atomic flag is performed here, rather than |
3018 | * the more obvious place, simply to reduce the critical path length |
3019 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they |
3020 | * will eventually be caught here (where it matters). |
3021 | */ |
3022 | kmem_flagcheck(cachep, flags); |
3023 | |
3024 | /* |
3025 | * Get mem for the objs. Attempt to allocate a physical page from |
3026 | * 'nodeid'. |
3027 | */ |
3028 | if (!objp) |
3029 | objp = kmem_getpages(cachep, local_flags, nodeid); |
3030 | if (!objp) |
3031 | goto failed; |
3032 | |
3033 | /* Get slab management. */ |
3034 | slabp = alloc_slabmgmt(cachep, objp, offset, |
3035 | local_flags & ~GFP_CONSTRAINT_MASK, nodeid); |
3036 | if (!slabp) |
3037 | goto opps1; |
3038 | |
3039 | slab_map_pages(cachep, slabp, objp); |
3040 | |
3041 | cache_init_objs(cachep, slabp); |
3042 | |
3043 | if (local_flags & __GFP_WAIT) |
3044 | local_irq_disable(); |
3045 | check_irq_off(); |
3046 | spin_lock(&l3->list_lock); |
3047 | |
3048 | /* Make slab active. */ |
3049 | list_add_tail(&slabp->list, &(l3->slabs_free)); |
3050 | STATS_INC_GROWN(cachep); |
3051 | l3->free_objects += cachep->num; |
3052 | spin_unlock(&l3->list_lock); |
3053 | return 1; |
3054 | opps1: |
3055 | kmem_freepages(cachep, objp); |
3056 | failed: |
3057 | if (local_flags & __GFP_WAIT) |
3058 | local_irq_disable(); |
3059 | return 0; |
3060 | } |
3061 | |
3062 | #if DEBUG |
3063 | |
3064 | /* |
3065 | * Perform extra freeing checks: |
3066 | * - detect bad pointers. |
3067 | * - POISON/RED_ZONE checking |
3068 | */ |
3069 | static void kfree_debugcheck(const void *objp) |
3070 | { |
3071 | if (!virt_addr_valid(objp)) { |
3072 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
3073 | (unsigned long)objp); |
3074 | BUG(); |
3075 | } |
3076 | } |
3077 | |
3078 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) |
3079 | { |
3080 | unsigned long long redzone1, redzone2; |
3081 | |
3082 | redzone1 = *dbg_redzone1(cache, obj); |
3083 | redzone2 = *dbg_redzone2(cache, obj); |
3084 | |
3085 | /* |
3086 | * Redzone is ok. |
3087 | */ |
3088 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) |
3089 | return; |
3090 | |
3091 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) |
3092 | slab_error(cache, "double free detected"); |
3093 | else |
3094 | slab_error(cache, "memory outside object was overwritten"); |
3095 | |
3096 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", |
3097 | obj, redzone1, redzone2); |
3098 | } |
3099 | |
3100 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, |
3101 | void *caller) |
3102 | { |
3103 | struct page *page; |
3104 | unsigned int objnr; |
3105 | struct slab *slabp; |
3106 | |
3107 | BUG_ON(virt_to_cache(objp) != cachep); |
3108 | |
3109 | objp -= obj_offset(cachep); |
3110 | kfree_debugcheck(objp); |
3111 | page = virt_to_head_page(objp); |
3112 | |
3113 | slabp = page->slab_page; |
3114 | |
3115 | if (cachep->flags & SLAB_RED_ZONE) { |
3116 | verify_redzone_free(cachep, objp); |
3117 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
3118 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
3119 | } |
3120 | if (cachep->flags & SLAB_STORE_USER) |
3121 | *dbg_userword(cachep, objp) = caller; |
3122 | |
3123 | objnr = obj_to_index(cachep, slabp, objp); |
3124 | |
3125 | BUG_ON(objnr >= cachep->num); |
3126 | BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); |
3127 | |
3128 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
3129 | slab_bufctl(slabp)[objnr] = BUFCTL_FREE; |
3130 | #endif |
3131 | if (cachep->flags & SLAB_POISON) { |
3132 | #ifdef CONFIG_DEBUG_PAGEALLOC |
3133 | if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { |
3134 | store_stackinfo(cachep, objp, (unsigned long)caller); |
3135 | kernel_map_pages(virt_to_page(objp), |
3136 | cachep->size / PAGE_SIZE, 0); |
3137 | } else { |
3138 | poison_obj(cachep, objp, POISON_FREE); |
3139 | } |
3140 | #else |
3141 | poison_obj(cachep, objp, POISON_FREE); |
3142 | #endif |
3143 | } |
3144 | return objp; |
3145 | } |
3146 | |
3147 | static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) |
3148 | { |
3149 | kmem_bufctl_t i; |
3150 | int entries = 0; |
3151 | |
3152 | /* Check slab's freelist to see if this obj is there. */ |
3153 | for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { |
3154 | entries++; |
3155 | if (entries > cachep->num || i >= cachep->num) |
3156 | goto bad; |
3157 | } |
3158 | if (entries != cachep->num - slabp->inuse) { |
3159 | bad: |
3160 | printk(KERN_ERR "slab: Internal list corruption detected in " |
3161 | "cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n", |
3162 | cachep->name, cachep->num, slabp, slabp->inuse, |
3163 | print_tainted()); |
3164 | print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp, |
3165 | sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t), |
3166 | 1); |
3167 | BUG(); |
3168 | } |
3169 | } |
3170 | #else |
3171 | #define kfree_debugcheck(x) do { } while(0) |
3172 | #define cache_free_debugcheck(x,objp,z) (objp) |
3173 | #define check_slabp(x,y) do { } while(0) |
3174 | #endif |
3175 | |
3176 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, |
3177 | bool force_refill) |
3178 | { |
3179 | int batchcount; |
3180 | struct kmem_list3 *l3; |
3181 | struct array_cache *ac; |
3182 | int node; |
3183 | |
3184 | check_irq_off(); |
3185 | node = numa_mem_id(); |
3186 | if (unlikely(force_refill)) |
3187 | goto force_grow; |
3188 | retry: |
3189 | ac = cpu_cache_get(cachep); |
3190 | batchcount = ac->batchcount; |
3191 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
3192 | /* |
3193 | * If there was little recent activity on this cache, then |
3194 | * perform only a partial refill. Otherwise we could generate |
3195 | * refill bouncing. |
3196 | */ |
3197 | batchcount = BATCHREFILL_LIMIT; |
3198 | } |
3199 | l3 = cachep->nodelists[node]; |
3200 | |
3201 | BUG_ON(ac->avail > 0 || !l3); |
3202 | spin_lock(&l3->list_lock); |
3203 | |
3204 | /* See if we can refill from the shared array */ |
3205 | if (l3->shared && transfer_objects(ac, l3->shared, batchcount)) { |
3206 | l3->shared->touched = 1; |
3207 | goto alloc_done; |
3208 | } |
3209 | |
3210 | while (batchcount > 0) { |
3211 | struct list_head *entry; |
3212 | struct slab *slabp; |
3213 | /* Get slab alloc is to come from. */ |
3214 | entry = l3->slabs_partial.next; |
3215 | if (entry == &l3->slabs_partial) { |
3216 | l3->free_touched = 1; |
3217 | entry = l3->slabs_free.next; |
3218 | if (entry == &l3->slabs_free) |
3219 | goto must_grow; |
3220 | } |
3221 | |
3222 | slabp = list_entry(entry, struct slab, list); |
3223 | check_slabp(cachep, slabp); |
3224 | check_spinlock_acquired(cachep); |
3225 | |
3226 | /* |
3227 | * The slab was either on partial or free list so |
3228 | * there must be at least one object available for |
3229 | * allocation. |
3230 | */ |
3231 | BUG_ON(slabp->inuse >= cachep->num); |
3232 | |
3233 | while (slabp->inuse < cachep->num && batchcount--) { |
3234 | STATS_INC_ALLOCED(cachep); |
3235 | STATS_INC_ACTIVE(cachep); |
3236 | STATS_SET_HIGH(cachep); |
3237 | |
3238 | ac_put_obj(cachep, ac, slab_get_obj(cachep, slabp, |
3239 | node)); |
3240 | } |
3241 | check_slabp(cachep, slabp); |
3242 | |
3243 | /* move slabp to correct slabp list: */ |
3244 | list_del(&slabp->list); |
3245 | if (slabp->free == BUFCTL_END) |
3246 | list_add(&slabp->list, &l3->slabs_full); |
3247 | else |
3248 | list_add(&slabp->list, &l3->slabs_partial); |
3249 | } |
3250 | |
3251 | must_grow: |
3252 | l3->free_objects -= ac->avail; |
3253 | alloc_done: |
3254 | spin_unlock(&l3->list_lock); |
3255 | |
3256 | if (unlikely(!ac->avail)) { |
3257 | int x; |
3258 | force_grow: |
3259 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); |
3260 | |
3261 | /* cache_grow can reenable interrupts, then ac could change. */ |
3262 | ac = cpu_cache_get(cachep); |
3263 | |
3264 | /* no objects in sight? abort */ |
3265 | if (!x && (ac->avail == 0 || force_refill)) |
3266 | return NULL; |
3267 | |
3268 | if (!ac->avail) /* objects refilled by interrupt? */ |
3269 | goto retry; |
3270 | } |
3271 | ac->touched = 1; |
3272 | |
3273 | return ac_get_obj(cachep, ac, flags, force_refill); |
3274 | } |
3275 | |
3276 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, |
3277 | gfp_t flags) |
3278 | { |
3279 | might_sleep_if(flags & __GFP_WAIT); |
3280 | #if DEBUG |
3281 | kmem_flagcheck(cachep, flags); |
3282 | #endif |
3283 | } |
3284 | |
3285 | #if DEBUG |
3286 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, |
3287 | gfp_t flags, void *objp, void *caller) |
3288 | { |
3289 | if (!objp) |
3290 | return objp; |
3291 | if (cachep->flags & SLAB_POISON) { |
3292 | #ifdef CONFIG_DEBUG_PAGEALLOC |
3293 | if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
3294 | kernel_map_pages(virt_to_page(objp), |
3295 | cachep->size / PAGE_SIZE, 1); |
3296 | else |
3297 | check_poison_obj(cachep, objp); |
3298 | #else |
3299 | check_poison_obj(cachep, objp); |
3300 | #endif |
3301 | poison_obj(cachep, objp, POISON_INUSE); |
3302 | } |
3303 | if (cachep->flags & SLAB_STORE_USER) |
3304 | *dbg_userword(cachep, objp) = caller; |
3305 | |
3306 | if (cachep->flags & SLAB_RED_ZONE) { |
3307 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || |
3308 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
3309 | slab_error(cachep, "double free, or memory outside" |
3310 | " object was overwritten"); |
3311 | printk(KERN_ERR |
3312 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", |
3313 | objp, *dbg_redzone1(cachep, objp), |
3314 | *dbg_redzone2(cachep, objp)); |
3315 | } |
3316 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
3317 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
3318 | } |
3319 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
3320 | { |
3321 | struct slab *slabp; |
3322 | unsigned objnr; |
3323 | |
3324 | slabp = virt_to_head_page(objp)->slab_page; |
3325 | objnr = (unsigned)(objp - slabp->s_mem) / cachep->size; |
3326 | slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; |
3327 | } |
3328 | #endif |
3329 | objp += obj_offset(cachep); |
3330 | if (cachep->ctor && cachep->flags & SLAB_POISON) |
3331 | cachep->ctor(objp); |
3332 | if (ARCH_SLAB_MINALIGN && |
3333 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { |
3334 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", |
3335 | objp, (int)ARCH_SLAB_MINALIGN); |
3336 | } |
3337 | return objp; |
3338 | } |
3339 | #else |
3340 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
3341 | #endif |
3342 | |
3343 | static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) |
3344 | { |
3345 | if (cachep == &cache_cache) |
3346 | return false; |
3347 | |
3348 | return should_failslab(cachep->object_size, flags, cachep->flags); |
3349 | } |
3350 | |
3351 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3352 | { |
3353 | void *objp; |
3354 | struct array_cache *ac; |
3355 | bool force_refill = false; |
3356 | |
3357 | check_irq_off(); |
3358 | |
3359 | ac = cpu_cache_get(cachep); |
3360 | if (likely(ac->avail)) { |
3361 | ac->touched = 1; |
3362 | objp = ac_get_obj(cachep, ac, flags, false); |
3363 | |
3364 | /* |
3365 | * Allow for the possibility all avail objects are not allowed |
3366 | * by the current flags |
3367 | */ |
3368 | if (objp) { |
3369 | STATS_INC_ALLOCHIT(cachep); |
3370 | goto out; |
3371 | } |
3372 | force_refill = true; |
3373 | } |
3374 | |
3375 | STATS_INC_ALLOCMISS(cachep); |
3376 | objp = cache_alloc_refill(cachep, flags, force_refill); |
3377 | /* |
3378 | * the 'ac' may be updated by cache_alloc_refill(), |
3379 | * and kmemleak_erase() requires its correct value. |
3380 | */ |
3381 | ac = cpu_cache_get(cachep); |
3382 | |
3383 | out: |
3384 | /* |
3385 | * To avoid a false negative, if an object that is in one of the |
3386 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't |
3387 | * treat the array pointers as a reference to the object. |
3388 | */ |
3389 | if (objp) |
3390 | kmemleak_erase(&ac->entry[ac->avail]); |
3391 | return objp; |
3392 | } |
3393 | |
3394 | #ifdef CONFIG_NUMA |
3395 | /* |
3396 | * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. |
3397 | * |
3398 | * If we are in_interrupt, then process context, including cpusets and |
3399 | * mempolicy, may not apply and should not be used for allocation policy. |
3400 | */ |
3401 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) |
3402 | { |
3403 | int nid_alloc, nid_here; |
3404 | |
3405 | if (in_interrupt() || (flags & __GFP_THISNODE)) |
3406 | return NULL; |
3407 | nid_alloc = nid_here = numa_mem_id(); |
3408 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) |
3409 | nid_alloc = cpuset_slab_spread_node(); |
3410 | else if (current->mempolicy) |
3411 | nid_alloc = slab_node(); |
3412 | if (nid_alloc != nid_here) |
3413 | return ____cache_alloc_node(cachep, flags, nid_alloc); |
3414 | return NULL; |
3415 | } |
3416 | |
3417 | /* |
3418 | * Fallback function if there was no memory available and no objects on a |
3419 | * certain node and fall back is permitted. First we scan all the |
3420 | * available nodelists for available objects. If that fails then we |
3421 | * perform an allocation without specifying a node. This allows the page |
3422 | * allocator to do its reclaim / fallback magic. We then insert the |
3423 | * slab into the proper nodelist and then allocate from it. |
3424 | */ |
3425 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) |
3426 | { |
3427 | struct zonelist *zonelist; |
3428 | gfp_t local_flags; |
3429 | struct zoneref *z; |
3430 | struct zone *zone; |
3431 | enum zone_type high_zoneidx = gfp_zone(flags); |
3432 | void *obj = NULL; |
3433 | int nid; |
3434 | unsigned int cpuset_mems_cookie; |
3435 | |
3436 | if (flags & __GFP_THISNODE) |
3437 | return NULL; |
3438 | |
3439 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
3440 | |
3441 | retry_cpuset: |
3442 | cpuset_mems_cookie = get_mems_allowed(); |
3443 | zonelist = node_zonelist(slab_node(), flags); |
3444 | |
3445 | retry: |
3446 | /* |
3447 | * Look through allowed nodes for objects available |
3448 | * from existing per node queues. |
3449 | */ |
3450 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
3451 | nid = zone_to_nid(zone); |
3452 | |
3453 | if (cpuset_zone_allowed_hardwall(zone, flags) && |
3454 | cache->nodelists[nid] && |
3455 | cache->nodelists[nid]->free_objects) { |
3456 | obj = ____cache_alloc_node(cache, |
3457 | flags | GFP_THISNODE, nid); |
3458 | if (obj) |
3459 | break; |
3460 | } |
3461 | } |
3462 | |
3463 | if (!obj) { |
3464 | /* |
3465 | * This allocation will be performed within the constraints |
3466 | * of the current cpuset / memory policy requirements. |
3467 | * We may trigger various forms of reclaim on the allowed |
3468 | * set and go into memory reserves if necessary. |
3469 | */ |
3470 | if (local_flags & __GFP_WAIT) |
3471 | local_irq_enable(); |
3472 | kmem_flagcheck(cache, flags); |
3473 | obj = kmem_getpages(cache, local_flags, numa_mem_id()); |
3474 | if (local_flags & __GFP_WAIT) |
3475 | local_irq_disable(); |
3476 | if (obj) { |
3477 | /* |
3478 | * Insert into the appropriate per node queues |
3479 | */ |
3480 | nid = page_to_nid(virt_to_page(obj)); |
3481 | if (cache_grow(cache, flags, nid, obj)) { |
3482 | obj = ____cache_alloc_node(cache, |
3483 | flags | GFP_THISNODE, nid); |
3484 | if (!obj) |
3485 | /* |
3486 | * Another processor may allocate the |
3487 | * objects in the slab since we are |
3488 | * not holding any locks. |
3489 | */ |
3490 | goto retry; |
3491 | } else { |
3492 | /* cache_grow already freed obj */ |
3493 | obj = NULL; |
3494 | } |
3495 | } |
3496 | } |
3497 | |
3498 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !obj)) |
3499 | goto retry_cpuset; |
3500 | return obj; |
3501 | } |
3502 | |
3503 | /* |
3504 | * A interface to enable slab creation on nodeid |
3505 | */ |
3506 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, |
3507 | int nodeid) |
3508 | { |
3509 | struct list_head *entry; |
3510 | struct slab *slabp; |
3511 | struct kmem_list3 *l3; |
3512 | void *obj; |
3513 | int x; |
3514 | |
3515 | l3 = cachep->nodelists[nodeid]; |
3516 | BUG_ON(!l3); |
3517 | |
3518 | retry: |
3519 | check_irq_off(); |
3520 | spin_lock(&l3->list_lock); |
3521 | entry = l3->slabs_partial.next; |
3522 | if (entry == &l3->slabs_partial) { |
3523 | l3->free_touched = 1; |
3524 | entry = l3->slabs_free.next; |
3525 | if (entry == &l3->slabs_free) |
3526 | goto must_grow; |
3527 | } |
3528 | |
3529 | slabp = list_entry(entry, struct slab, list); |
3530 | check_spinlock_acquired_node(cachep, nodeid); |
3531 | check_slabp(cachep, slabp); |
3532 | |
3533 | STATS_INC_NODEALLOCS(cachep); |
3534 | STATS_INC_ACTIVE(cachep); |
3535 | STATS_SET_HIGH(cachep); |
3536 | |
3537 | BUG_ON(slabp->inuse == cachep->num); |
3538 | |
3539 | obj = slab_get_obj(cachep, slabp, nodeid); |
3540 | check_slabp(cachep, slabp); |
3541 | l3->free_objects--; |
3542 | /* move slabp to correct slabp list: */ |
3543 | list_del(&slabp->list); |
3544 | |
3545 | if (slabp->free == BUFCTL_END) |
3546 | list_add(&slabp->list, &l3->slabs_full); |
3547 | else |
3548 | list_add(&slabp->list, &l3->slabs_partial); |
3549 | |
3550 | spin_unlock(&l3->list_lock); |
3551 | goto done; |
3552 | |
3553 | must_grow: |
3554 | spin_unlock(&l3->list_lock); |
3555 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); |
3556 | if (x) |
3557 | goto retry; |
3558 | |
3559 | return fallback_alloc(cachep, flags); |
3560 | |
3561 | done: |
3562 | return obj; |
3563 | } |
3564 | |
3565 | /** |
3566 | * kmem_cache_alloc_node - Allocate an object on the specified node |
3567 | * @cachep: The cache to allocate from. |
3568 | * @flags: See kmalloc(). |
3569 | * @nodeid: node number of the target node. |
3570 | * @caller: return address of caller, used for debug information |
3571 | * |
3572 | * Identical to kmem_cache_alloc but it will allocate memory on the given |
3573 | * node, which can improve the performance for cpu bound structures. |
3574 | * |
3575 | * Fallback to other node is possible if __GFP_THISNODE is not set. |
3576 | */ |
3577 | static __always_inline void * |
3578 | __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, |
3579 | void *caller) |
3580 | { |
3581 | unsigned long save_flags; |
3582 | void *ptr; |
3583 | int slab_node = numa_mem_id(); |
3584 | |
3585 | flags &= gfp_allowed_mask; |
3586 | |
3587 | lockdep_trace_alloc(flags); |
3588 | |
3589 | if (slab_should_failslab(cachep, flags)) |
3590 | return NULL; |
3591 | |
3592 | cache_alloc_debugcheck_before(cachep, flags); |
3593 | local_irq_save(save_flags); |
3594 | |
3595 | if (nodeid == NUMA_NO_NODE) |
3596 | nodeid = slab_node; |
3597 | |
3598 | if (unlikely(!cachep->nodelists[nodeid])) { |
3599 | /* Node not bootstrapped yet */ |
3600 | ptr = fallback_alloc(cachep, flags); |
3601 | goto out; |
3602 | } |
3603 | |
3604 | if (nodeid == slab_node) { |
3605 | /* |
3606 | * Use the locally cached objects if possible. |
3607 | * However ____cache_alloc does not allow fallback |
3608 | * to other nodes. It may fail while we still have |
3609 | * objects on other nodes available. |
3610 | */ |
3611 | ptr = ____cache_alloc(cachep, flags); |
3612 | if (ptr) |
3613 | goto out; |
3614 | } |
3615 | /* ___cache_alloc_node can fall back to other nodes */ |
3616 | ptr = ____cache_alloc_node(cachep, flags, nodeid); |
3617 | out: |
3618 | local_irq_restore(save_flags); |
3619 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
3620 | kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, |
3621 | flags); |
3622 | |
3623 | if (likely(ptr)) |
3624 | kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); |
3625 | |
3626 | if (unlikely((flags & __GFP_ZERO) && ptr)) |
3627 | memset(ptr, 0, cachep->object_size); |
3628 | |
3629 | return ptr; |
3630 | } |
3631 | |
3632 | static __always_inline void * |
3633 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) |
3634 | { |
3635 | void *objp; |
3636 | |
3637 | if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { |
3638 | objp = alternate_node_alloc(cache, flags); |
3639 | if (objp) |
3640 | goto out; |
3641 | } |
3642 | objp = ____cache_alloc(cache, flags); |
3643 | |
3644 | /* |
3645 | * We may just have run out of memory on the local node. |
3646 | * ____cache_alloc_node() knows how to locate memory on other nodes |
3647 | */ |
3648 | if (!objp) |
3649 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); |
3650 | |
3651 | out: |
3652 | return objp; |
3653 | } |
3654 | #else |
3655 | |
3656 | static __always_inline void * |
3657 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3658 | { |
3659 | return ____cache_alloc(cachep, flags); |
3660 | } |
3661 | |
3662 | #endif /* CONFIG_NUMA */ |
3663 | |
3664 | static __always_inline void * |
3665 | __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) |
3666 | { |
3667 | unsigned long save_flags; |
3668 | void *objp; |
3669 | |
3670 | flags &= gfp_allowed_mask; |
3671 | |
3672 | lockdep_trace_alloc(flags); |
3673 | |
3674 | if (slab_should_failslab(cachep, flags)) |
3675 | return NULL; |
3676 | |
3677 | cache_alloc_debugcheck_before(cachep, flags); |
3678 | local_irq_save(save_flags); |
3679 | objp = __do_cache_alloc(cachep, flags); |
3680 | local_irq_restore(save_flags); |
3681 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
3682 | kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, |
3683 | flags); |
3684 | prefetchw(objp); |
3685 | |
3686 | if (likely(objp)) |
3687 | kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); |
3688 | |
3689 | if (unlikely((flags & __GFP_ZERO) && objp)) |
3690 | memset(objp, 0, cachep->object_size); |
3691 | |
3692 | return objp; |
3693 | } |
3694 | |
3695 | /* |
3696 | * Caller needs to acquire correct kmem_list's list_lock |
3697 | */ |
3698 | static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, |
3699 | int node) |
3700 | { |
3701 | int i; |
3702 | struct kmem_list3 *l3; |
3703 | |
3704 | for (i = 0; i < nr_objects; i++) { |
3705 | void *objp; |
3706 | struct slab *slabp; |
3707 | |
3708 | clear_obj_pfmemalloc(&objpp[i]); |
3709 | objp = objpp[i]; |
3710 | |
3711 | slabp = virt_to_slab(objp); |
3712 | l3 = cachep->nodelists[node]; |
3713 | list_del(&slabp->list); |
3714 | check_spinlock_acquired_node(cachep, node); |
3715 | check_slabp(cachep, slabp); |
3716 | slab_put_obj(cachep, slabp, objp, node); |
3717 | STATS_DEC_ACTIVE(cachep); |
3718 | l3->free_objects++; |
3719 | check_slabp(cachep, slabp); |
3720 | |
3721 | /* fixup slab chains */ |
3722 | if (slabp->inuse == 0) { |
3723 | if (l3->free_objects > l3->free_limit) { |
3724 | l3->free_objects -= cachep->num; |
3725 | /* No need to drop any previously held |
3726 | * lock here, even if we have a off-slab slab |
3727 | * descriptor it is guaranteed to come from |
3728 | * a different cache, refer to comments before |
3729 | * alloc_slabmgmt. |
3730 | */ |
3731 | slab_destroy(cachep, slabp); |
3732 | } else { |
3733 | list_add(&slabp->list, &l3->slabs_free); |
3734 | } |
3735 | } else { |
3736 | /* Unconditionally move a slab to the end of the |
3737 | * partial list on free - maximum time for the |
3738 | * other objects to be freed, too. |
3739 | */ |
3740 | list_add_tail(&slabp->list, &l3->slabs_partial); |
3741 | } |
3742 | } |
3743 | } |
3744 | |
3745 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) |
3746 | { |
3747 | int batchcount; |
3748 | struct kmem_list3 *l3; |
3749 | int node = numa_mem_id(); |
3750 | |
3751 | batchcount = ac->batchcount; |
3752 | #if DEBUG |
3753 | BUG_ON(!batchcount || batchcount > ac->avail); |
3754 | #endif |
3755 | check_irq_off(); |
3756 | l3 = cachep->nodelists[node]; |
3757 | spin_lock(&l3->list_lock); |
3758 | if (l3->shared) { |
3759 | struct array_cache *shared_array = l3->shared; |
3760 | int max = shared_array->limit - shared_array->avail; |
3761 | if (max) { |
3762 | if (batchcount > max) |
3763 | batchcount = max; |
3764 | memcpy(&(shared_array->entry[shared_array->avail]), |
3765 | ac->entry, sizeof(void *) * batchcount); |
3766 | shared_array->avail += batchcount; |
3767 | goto free_done; |
3768 | } |
3769 | } |
3770 | |
3771 | free_block(cachep, ac->entry, batchcount, node); |
3772 | free_done: |
3773 | #if STATS |
3774 | { |
3775 | int i = 0; |
3776 | struct list_head *p; |
3777 | |
3778 | p = l3->slabs_free.next; |
3779 | while (p != &(l3->slabs_free)) { |
3780 | struct slab *slabp; |
3781 | |
3782 | slabp = list_entry(p, struct slab, list); |
3783 | BUG_ON(slabp->inuse); |
3784 | |
3785 | i++; |
3786 | p = p->next; |
3787 | } |
3788 | STATS_SET_FREEABLE(cachep, i); |
3789 | } |
3790 | #endif |
3791 | spin_unlock(&l3->list_lock); |
3792 | ac->avail -= batchcount; |
3793 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); |
3794 | } |
3795 | |
3796 | /* |
3797 | * Release an obj back to its cache. If the obj has a constructed state, it must |
3798 | * be in this state _before_ it is released. Called with disabled ints. |
3799 | */ |
3800 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, |
3801 | void *caller) |
3802 | { |
3803 | struct array_cache *ac = cpu_cache_get(cachep); |
3804 | |
3805 | check_irq_off(); |
3806 | kmemleak_free_recursive(objp, cachep->flags); |
3807 | objp = cache_free_debugcheck(cachep, objp, caller); |
3808 | |
3809 | kmemcheck_slab_free(cachep, objp, cachep->object_size); |
3810 | |
3811 | /* |
3812 | * Skip calling cache_free_alien() when the platform is not numa. |
3813 | * This will avoid cache misses that happen while accessing slabp (which |
3814 | * is per page memory reference) to get nodeid. Instead use a global |
3815 | * variable to skip the call, which is mostly likely to be present in |
3816 | * the cache. |
3817 | */ |
3818 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) |
3819 | return; |
3820 | |
3821 | if (likely(ac->avail < ac->limit)) { |
3822 | STATS_INC_FREEHIT(cachep); |
3823 | } else { |
3824 | STATS_INC_FREEMISS(cachep); |
3825 | cache_flusharray(cachep, ac); |
3826 | } |
3827 | |
3828 | ac_put_obj(cachep, ac, objp); |
3829 | } |
3830 | |
3831 | /** |
3832 | * kmem_cache_alloc - Allocate an object |
3833 | * @cachep: The cache to allocate from. |
3834 | * @flags: See kmalloc(). |
3835 | * |
3836 | * Allocate an object from this cache. The flags are only relevant |
3837 | * if the cache has no available objects. |
3838 | */ |
3839 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3840 | { |
3841 | void *ret = __cache_alloc(cachep, flags, __builtin_return_address(0)); |
3842 | |
3843 | trace_kmem_cache_alloc(_RET_IP_, ret, |
3844 | cachep->object_size, cachep->size, flags); |
3845 | |
3846 | return ret; |
3847 | } |
3848 | EXPORT_SYMBOL(kmem_cache_alloc); |
3849 | |
3850 | #ifdef CONFIG_TRACING |
3851 | void * |
3852 | kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags) |
3853 | { |
3854 | void *ret; |
3855 | |
3856 | ret = __cache_alloc(cachep, flags, __builtin_return_address(0)); |
3857 | |
3858 | trace_kmalloc(_RET_IP_, ret, |
3859 | size, slab_buffer_size(cachep), flags); |
3860 | return ret; |
3861 | } |
3862 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
3863 | #endif |
3864 | |
3865 | #ifdef CONFIG_NUMA |
3866 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
3867 | { |
3868 | void *ret = __cache_alloc_node(cachep, flags, nodeid, |
3869 | __builtin_return_address(0)); |
3870 | |
3871 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
3872 | cachep->object_size, cachep->size, |
3873 | flags, nodeid); |
3874 | |
3875 | return ret; |
3876 | } |
3877 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
3878 | |
3879 | #ifdef CONFIG_TRACING |
3880 | void *kmem_cache_alloc_node_trace(size_t size, |
3881 | struct kmem_cache *cachep, |
3882 | gfp_t flags, |
3883 | int nodeid) |
3884 | { |
3885 | void *ret; |
3886 | |
3887 | ret = __cache_alloc_node(cachep, flags, nodeid, |
3888 | __builtin_return_address(0)); |
3889 | trace_kmalloc_node(_RET_IP_, ret, |
3890 | size, slab_buffer_size(cachep), |
3891 | flags, nodeid); |
3892 | return ret; |
3893 | } |
3894 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
3895 | #endif |
3896 | |
3897 | static __always_inline void * |
3898 | __do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller) |
3899 | { |
3900 | struct kmem_cache *cachep; |
3901 | |
3902 | cachep = kmem_find_general_cachep(size, flags); |
3903 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3904 | return cachep; |
3905 | return kmem_cache_alloc_node_trace(size, cachep, flags, node); |
3906 | } |
3907 | |
3908 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3909 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3910 | { |
3911 | return __do_kmalloc_node(size, flags, node, |
3912 | __builtin_return_address(0)); |
3913 | } |
3914 | EXPORT_SYMBOL(__kmalloc_node); |
3915 | |
3916 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, |
3917 | int node, unsigned long caller) |
3918 | { |
3919 | return __do_kmalloc_node(size, flags, node, (void *)caller); |
3920 | } |
3921 | EXPORT_SYMBOL(__kmalloc_node_track_caller); |
3922 | #else |
3923 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3924 | { |
3925 | return __do_kmalloc_node(size, flags, node, NULL); |
3926 | } |
3927 | EXPORT_SYMBOL(__kmalloc_node); |
3928 | #endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ |
3929 | #endif /* CONFIG_NUMA */ |
3930 | |
3931 | /** |
3932 | * __do_kmalloc - allocate memory |
3933 | * @size: how many bytes of memory are required. |
3934 | * @flags: the type of memory to allocate (see kmalloc). |
3935 | * @caller: function caller for debug tracking of the caller |
3936 | */ |
3937 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, |
3938 | void *caller) |
3939 | { |
3940 | struct kmem_cache *cachep; |
3941 | void *ret; |
3942 | |
3943 | /* If you want to save a few bytes .text space: replace |
3944 | * __ with kmem_. |
3945 | * Then kmalloc uses the uninlined functions instead of the inline |
3946 | * functions. |
3947 | */ |
3948 | cachep = __find_general_cachep(size, flags); |
3949 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3950 | return cachep; |
3951 | ret = __cache_alloc(cachep, flags, caller); |
3952 | |
3953 | trace_kmalloc((unsigned long) caller, ret, |
3954 | size, cachep->size, flags); |
3955 | |
3956 | return ret; |
3957 | } |
3958 | |
3959 | |
3960 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3961 | void *__kmalloc(size_t size, gfp_t flags) |
3962 | { |
3963 | return __do_kmalloc(size, flags, __builtin_return_address(0)); |
3964 | } |
3965 | EXPORT_SYMBOL(__kmalloc); |
3966 | |
3967 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) |
3968 | { |
3969 | return __do_kmalloc(size, flags, (void *)caller); |
3970 | } |
3971 | EXPORT_SYMBOL(__kmalloc_track_caller); |
3972 | |
3973 | #else |
3974 | void *__kmalloc(size_t size, gfp_t flags) |
3975 | { |
3976 | return __do_kmalloc(size, flags, NULL); |
3977 | } |
3978 | EXPORT_SYMBOL(__kmalloc); |
3979 | #endif |
3980 | |
3981 | /** |
3982 | * kmem_cache_free - Deallocate an object |
3983 | * @cachep: The cache the allocation was from. |
3984 | * @objp: The previously allocated object. |
3985 | * |
3986 | * Free an object which was previously allocated from this |
3987 | * cache. |
3988 | */ |
3989 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) |
3990 | { |
3991 | unsigned long flags; |
3992 | |
3993 | local_irq_save(flags); |
3994 | debug_check_no_locks_freed(objp, cachep->object_size); |
3995 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) |
3996 | debug_check_no_obj_freed(objp, cachep->object_size); |
3997 | __cache_free(cachep, objp, __builtin_return_address(0)); |
3998 | local_irq_restore(flags); |
3999 | |
4000 | trace_kmem_cache_free(_RET_IP_, objp); |
4001 | } |
4002 | EXPORT_SYMBOL(kmem_cache_free); |
4003 | |
4004 | /** |
4005 | * kfree - free previously allocated memory |
4006 | * @objp: pointer returned by kmalloc. |
4007 | * |
4008 | * If @objp is NULL, no operation is performed. |
4009 | * |
4010 | * Don't free memory not originally allocated by kmalloc() |
4011 | * or you will run into trouble. |
4012 | */ |
4013 | void kfree(const void *objp) |
4014 | { |
4015 | struct kmem_cache *c; |
4016 | unsigned long flags; |
4017 | |
4018 | trace_kfree(_RET_IP_, objp); |
4019 | |
4020 | if (unlikely(ZERO_OR_NULL_PTR(objp))) |
4021 | return; |
4022 | local_irq_save(flags); |
4023 | kfree_debugcheck(objp); |
4024 | c = virt_to_cache(objp); |
4025 | debug_check_no_locks_freed(objp, c->object_size); |
4026 | |
4027 | debug_check_no_obj_freed(objp, c->object_size); |
4028 | __cache_free(c, (void *)objp, __builtin_return_address(0)); |
4029 | local_irq_restore(flags); |
4030 | } |
4031 | EXPORT_SYMBOL(kfree); |
4032 | |
4033 | unsigned int kmem_cache_size(struct kmem_cache *cachep) |
4034 | { |
4035 | return cachep->object_size; |
4036 | } |
4037 | EXPORT_SYMBOL(kmem_cache_size); |
4038 | |
4039 | /* |
4040 | * This initializes kmem_list3 or resizes various caches for all nodes. |
4041 | */ |
4042 | static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) |
4043 | { |
4044 | int node; |
4045 | struct kmem_list3 *l3; |
4046 | struct array_cache *new_shared; |
4047 | struct array_cache **new_alien = NULL; |
4048 | |
4049 | for_each_online_node(node) { |
4050 | |
4051 | if (use_alien_caches) { |
4052 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); |
4053 | if (!new_alien) |
4054 | goto fail; |
4055 | } |
4056 | |
4057 | new_shared = NULL; |
4058 | if (cachep->shared) { |
4059 | new_shared = alloc_arraycache(node, |
4060 | cachep->shared*cachep->batchcount, |
4061 | 0xbaadf00d, gfp); |
4062 | if (!new_shared) { |
4063 | free_alien_cache(new_alien); |
4064 | goto fail; |
4065 | } |
4066 | } |
4067 | |
4068 | l3 = cachep->nodelists[node]; |
4069 | if (l3) { |
4070 | struct array_cache *shared = l3->shared; |
4071 | |
4072 | spin_lock_irq(&l3->list_lock); |
4073 | |
4074 | if (shared) |
4075 | free_block(cachep, shared->entry, |
4076 | shared->avail, node); |
4077 | |
4078 | l3->shared = new_shared; |
4079 | if (!l3->alien) { |
4080 | l3->alien = new_alien; |
4081 | new_alien = NULL; |
4082 | } |
4083 | l3->free_limit = (1 + nr_cpus_node(node)) * |
4084 | cachep->batchcount + cachep->num; |
4085 | spin_unlock_irq(&l3->list_lock); |
4086 | kfree(shared); |
4087 | free_alien_cache(new_alien); |
4088 | continue; |
4089 | } |
4090 | l3 = kmalloc_node(sizeof(struct kmem_list3), gfp, node); |
4091 | if (!l3) { |
4092 | free_alien_cache(new_alien); |
4093 | kfree(new_shared); |
4094 | goto fail; |
4095 | } |
4096 | |
4097 | kmem_list3_init(l3); |
4098 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
4099 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
4100 | l3->shared = new_shared; |
4101 | l3->alien = new_alien; |
4102 | l3->free_limit = (1 + nr_cpus_node(node)) * |
4103 | cachep->batchcount + cachep->num; |
4104 | cachep->nodelists[node] = l3; |
4105 | } |
4106 | return 0; |
4107 | |
4108 | fail: |
4109 | if (!cachep->list.next) { |
4110 | /* Cache is not active yet. Roll back what we did */ |
4111 | node--; |
4112 | while (node >= 0) { |
4113 | if (cachep->nodelists[node]) { |
4114 | l3 = cachep->nodelists[node]; |
4115 | |
4116 | kfree(l3->shared); |
4117 | free_alien_cache(l3->alien); |
4118 | kfree(l3); |
4119 | cachep->nodelists[node] = NULL; |
4120 | } |
4121 | node--; |
4122 | } |
4123 | } |
4124 | return -ENOMEM; |
4125 | } |
4126 | |
4127 | struct ccupdate_struct { |
4128 | struct kmem_cache *cachep; |
4129 | struct array_cache *new[0]; |
4130 | }; |
4131 | |
4132 | static void do_ccupdate_local(void *info) |
4133 | { |
4134 | struct ccupdate_struct *new = info; |
4135 | struct array_cache *old; |
4136 | |
4137 | check_irq_off(); |
4138 | old = cpu_cache_get(new->cachep); |
4139 | |
4140 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; |
4141 | new->new[smp_processor_id()] = old; |
4142 | } |
4143 | |
4144 | /* Always called with the slab_mutex held */ |
4145 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, |
4146 | int batchcount, int shared, gfp_t gfp) |
4147 | { |
4148 | struct ccupdate_struct *new; |
4149 | int i; |
4150 | |
4151 | new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *), |
4152 | gfp); |
4153 | if (!new) |
4154 | return -ENOMEM; |
4155 | |
4156 | for_each_online_cpu(i) { |
4157 | new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, |
4158 | batchcount, gfp); |
4159 | if (!new->new[i]) { |
4160 | for (i--; i >= 0; i--) |
4161 | kfree(new->new[i]); |
4162 | kfree(new); |
4163 | return -ENOMEM; |
4164 | } |
4165 | } |
4166 | new->cachep = cachep; |
4167 | |
4168 | on_each_cpu(do_ccupdate_local, (void *)new, 1); |
4169 | |
4170 | check_irq_on(); |
4171 | cachep->batchcount = batchcount; |
4172 | cachep->limit = limit; |
4173 | cachep->shared = shared; |
4174 | |
4175 | for_each_online_cpu(i) { |
4176 | struct array_cache *ccold = new->new[i]; |
4177 | if (!ccold) |
4178 | continue; |
4179 | spin_lock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); |
4180 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); |
4181 | spin_unlock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); |
4182 | kfree(ccold); |
4183 | } |
4184 | kfree(new); |
4185 | return alloc_kmemlist(cachep, gfp); |
4186 | } |
4187 | |
4188 | /* Called with slab_mutex held always */ |
4189 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) |
4190 | { |
4191 | int err; |
4192 | int limit, shared; |
4193 | |
4194 | /* |
4195 | * The head array serves three purposes: |
4196 | * - create a LIFO ordering, i.e. return objects that are cache-warm |
4197 | * - reduce the number of spinlock operations. |
4198 | * - reduce the number of linked list operations on the slab and |
4199 | * bufctl chains: array operations are cheaper. |
4200 | * The numbers are guessed, we should auto-tune as described by |
4201 | * Bonwick. |
4202 | */ |
4203 | if (cachep->size > 131072) |
4204 | limit = 1; |
4205 | else if (cachep->size > PAGE_SIZE) |
4206 | limit = 8; |
4207 | else if (cachep->size > 1024) |
4208 | limit = 24; |
4209 | else if (cachep->size > 256) |
4210 | limit = 54; |
4211 | else |
4212 | limit = 120; |
4213 | |
4214 | /* |
4215 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound |
4216 | * allocation behaviour: Most allocs on one cpu, most free operations |
4217 | * on another cpu. For these cases, an efficient object passing between |
4218 | * cpus is necessary. This is provided by a shared array. The array |
4219 | * replaces Bonwick's magazine layer. |
4220 | * On uniprocessor, it's functionally equivalent (but less efficient) |
4221 | * to a larger limit. Thus disabled by default. |
4222 | */ |
4223 | shared = 0; |
4224 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) |
4225 | shared = 8; |
4226 | |
4227 | #if DEBUG |
4228 | /* |
4229 | * With debugging enabled, large batchcount lead to excessively long |
4230 | * periods with disabled local interrupts. Limit the batchcount |
4231 | */ |
4232 | if (limit > 32) |
4233 | limit = 32; |
4234 | #endif |
4235 | err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared, gfp); |
4236 | if (err) |
4237 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", |
4238 | cachep->name, -err); |
4239 | return err; |
4240 | } |
4241 | |
4242 | /* |
4243 | * Drain an array if it contains any elements taking the l3 lock only if |
4244 | * necessary. Note that the l3 listlock also protects the array_cache |
4245 | * if drain_array() is used on the shared array. |
4246 | */ |
4247 | static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, |
4248 | struct array_cache *ac, int force, int node) |
4249 | { |
4250 | int tofree; |
4251 | |
4252 | if (!ac || !ac->avail) |
4253 | return; |
4254 | if (ac->touched && !force) { |
4255 | ac->touched = 0; |
4256 | } else { |
4257 | spin_lock_irq(&l3->list_lock); |
4258 | if (ac->avail) { |
4259 | tofree = force ? ac->avail : (ac->limit + 4) / 5; |
4260 | if (tofree > ac->avail) |
4261 | tofree = (ac->avail + 1) / 2; |
4262 | free_block(cachep, ac->entry, tofree, node); |
4263 | ac->avail -= tofree; |
4264 | memmove(ac->entry, &(ac->entry[tofree]), |
4265 | sizeof(void *) * ac->avail); |
4266 | } |
4267 | spin_unlock_irq(&l3->list_lock); |
4268 | } |
4269 | } |
4270 | |
4271 | /** |
4272 | * cache_reap - Reclaim memory from caches. |
4273 | * @w: work descriptor |
4274 | * |
4275 | * Called from workqueue/eventd every few seconds. |
4276 | * Purpose: |
4277 | * - clear the per-cpu caches for this CPU. |
4278 | * - return freeable pages to the main free memory pool. |
4279 | * |
4280 | * If we cannot acquire the cache chain mutex then just give up - we'll try |
4281 | * again on the next iteration. |
4282 | */ |
4283 | static void cache_reap(struct work_struct *w) |
4284 | { |
4285 | struct kmem_cache *searchp; |
4286 | struct kmem_list3 *l3; |
4287 | int node = numa_mem_id(); |
4288 | struct delayed_work *work = to_delayed_work(w); |
4289 | |
4290 | if (!mutex_trylock(&slab_mutex)) |
4291 | /* Give up. Setup the next iteration. */ |
4292 | goto out; |
4293 | |
4294 | list_for_each_entry(searchp, &slab_caches, list) { |
4295 | check_irq_on(); |
4296 | |
4297 | /* |
4298 | * We only take the l3 lock if absolutely necessary and we |
4299 | * have established with reasonable certainty that |
4300 | * we can do some work if the lock was obtained. |
4301 | */ |
4302 | l3 = searchp->nodelists[node]; |
4303 | |
4304 | reap_alien(searchp, l3); |
4305 | |
4306 | drain_array(searchp, l3, cpu_cache_get(searchp), 0, node); |
4307 | |
4308 | /* |
4309 | * These are racy checks but it does not matter |
4310 | * if we skip one check or scan twice. |
4311 | */ |
4312 | if (time_after(l3->next_reap, jiffies)) |
4313 | goto next; |
4314 | |
4315 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3; |
4316 | |
4317 | drain_array(searchp, l3, l3->shared, 0, node); |
4318 | |
4319 | if (l3->free_touched) |
4320 | l3->free_touched = 0; |
4321 | else { |
4322 | int freed; |
4323 | |
4324 | freed = drain_freelist(searchp, l3, (l3->free_limit + |
4325 | 5 * searchp->num - 1) / (5 * searchp->num)); |
4326 | STATS_ADD_REAPED(searchp, freed); |
4327 | } |
4328 | next: |
4329 | cond_resched(); |
4330 | } |
4331 | check_irq_on(); |
4332 | mutex_unlock(&slab_mutex); |
4333 | next_reap_node(); |
4334 | out: |
4335 | /* Set up the next iteration */ |
4336 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); |
4337 | } |
4338 | |
4339 | #ifdef CONFIG_SLABINFO |
4340 | |
4341 | static void print_slabinfo_header(struct seq_file *m) |
4342 | { |
4343 | /* |
4344 | * Output format version, so at least we can change it |
4345 | * without _too_ many complaints. |
4346 | */ |
4347 | #if STATS |
4348 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); |
4349 | #else |
4350 | seq_puts(m, "slabinfo - version: 2.1\n"); |
4351 | #endif |
4352 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " |
4353 | "<objperslab> <pagesperslab>"); |
4354 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
4355 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); |
4356 | #if STATS |
4357 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " |
4358 | "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); |
4359 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); |
4360 | #endif |
4361 | seq_putc(m, '\n'); |
4362 | } |
4363 | |
4364 | static void *s_start(struct seq_file *m, loff_t *pos) |
4365 | { |
4366 | loff_t n = *pos; |
4367 | |
4368 | mutex_lock(&slab_mutex); |
4369 | if (!n) |
4370 | print_slabinfo_header(m); |
4371 | |
4372 | return seq_list_start(&slab_caches, *pos); |
4373 | } |
4374 | |
4375 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) |
4376 | { |
4377 | return seq_list_next(p, &slab_caches, pos); |
4378 | } |
4379 | |
4380 | static void s_stop(struct seq_file *m, void *p) |
4381 | { |
4382 | mutex_unlock(&slab_mutex); |
4383 | } |
4384 | |
4385 | static int s_show(struct seq_file *m, void *p) |
4386 | { |
4387 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); |
4388 | struct slab *slabp; |
4389 | unsigned long active_objs; |
4390 | unsigned long num_objs; |
4391 | unsigned long active_slabs = 0; |
4392 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; |
4393 | const char *name; |
4394 | char *error = NULL; |
4395 | int node; |
4396 | struct kmem_list3 *l3; |
4397 | |
4398 | active_objs = 0; |
4399 | num_slabs = 0; |
4400 | for_each_online_node(node) { |
4401 | l3 = cachep->nodelists[node]; |
4402 | if (!l3) |
4403 | continue; |
4404 | |
4405 | check_irq_on(); |
4406 | spin_lock_irq(&l3->list_lock); |
4407 | |
4408 | list_for_each_entry(slabp, &l3->slabs_full, list) { |
4409 | if (slabp->inuse != cachep->num && !error) |
4410 | error = "slabs_full accounting error"; |
4411 | active_objs += cachep->num; |
4412 | active_slabs++; |
4413 | } |
4414 | list_for_each_entry(slabp, &l3->slabs_partial, list) { |
4415 | if (slabp->inuse == cachep->num && !error) |
4416 | error = "slabs_partial inuse accounting error"; |
4417 | if (!slabp->inuse && !error) |
4418 | error = "slabs_partial/inuse accounting error"; |
4419 | active_objs += slabp->inuse; |
4420 | active_slabs++; |
4421 | } |
4422 | list_for_each_entry(slabp, &l3->slabs_free, list) { |
4423 | if (slabp->inuse && !error) |
4424 | error = "slabs_free/inuse accounting error"; |
4425 | num_slabs++; |
4426 | } |
4427 | free_objects += l3->free_objects; |
4428 | if (l3->shared) |
4429 | shared_avail += l3->shared->avail; |
4430 | |
4431 | spin_unlock_irq(&l3->list_lock); |
4432 | } |
4433 | num_slabs += active_slabs; |
4434 | num_objs = num_slabs * cachep->num; |
4435 | if (num_objs - active_objs != free_objects && !error) |
4436 | error = "free_objects accounting error"; |
4437 | |
4438 | name = cachep->name; |
4439 | if (error) |
4440 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); |
4441 | |
4442 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
4443 | name, active_objs, num_objs, cachep->size, |
4444 | cachep->num, (1 << cachep->gfporder)); |
4445 | seq_printf(m, " : tunables %4u %4u %4u", |
4446 | cachep->limit, cachep->batchcount, cachep->shared); |
4447 | seq_printf(m, " : slabdata %6lu %6lu %6lu", |
4448 | active_slabs, num_slabs, shared_avail); |
4449 | #if STATS |
4450 | { /* list3 stats */ |
4451 | unsigned long high = cachep->high_mark; |
4452 | unsigned long allocs = cachep->num_allocations; |
4453 | unsigned long grown = cachep->grown; |
4454 | unsigned long reaped = cachep->reaped; |
4455 | unsigned long errors = cachep->errors; |
4456 | unsigned long max_freeable = cachep->max_freeable; |
4457 | unsigned long node_allocs = cachep->node_allocs; |
4458 | unsigned long node_frees = cachep->node_frees; |
4459 | unsigned long overflows = cachep->node_overflow; |
4460 | |
4461 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " |
4462 | "%4lu %4lu %4lu %4lu %4lu", |
4463 | allocs, high, grown, |
4464 | reaped, errors, max_freeable, node_allocs, |
4465 | node_frees, overflows); |
4466 | } |
4467 | /* cpu stats */ |
4468 | { |
4469 | unsigned long allochit = atomic_read(&cachep->allochit); |
4470 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
4471 | unsigned long freehit = atomic_read(&cachep->freehit); |
4472 | unsigned long freemiss = atomic_read(&cachep->freemiss); |
4473 | |
4474 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
4475 | allochit, allocmiss, freehit, freemiss); |
4476 | } |
4477 | #endif |
4478 | seq_putc(m, '\n'); |
4479 | return 0; |
4480 | } |
4481 | |
4482 | /* |
4483 | * slabinfo_op - iterator that generates /proc/slabinfo |
4484 | * |
4485 | * Output layout: |
4486 | * cache-name |
4487 | * num-active-objs |
4488 | * total-objs |
4489 | * object size |
4490 | * num-active-slabs |
4491 | * total-slabs |
4492 | * num-pages-per-slab |
4493 | * + further values on SMP and with statistics enabled |
4494 | */ |
4495 | |
4496 | static const struct seq_operations slabinfo_op = { |
4497 | .start = s_start, |
4498 | .next = s_next, |
4499 | .stop = s_stop, |
4500 | .show = s_show, |
4501 | }; |
4502 | |
4503 | #define MAX_SLABINFO_WRITE 128 |
4504 | /** |
4505 | * slabinfo_write - Tuning for the slab allocator |
4506 | * @file: unused |
4507 | * @buffer: user buffer |
4508 | * @count: data length |
4509 | * @ppos: unused |
4510 | */ |
4511 | static ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
4512 | size_t count, loff_t *ppos) |
4513 | { |
4514 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; |
4515 | int limit, batchcount, shared, res; |
4516 | struct kmem_cache *cachep; |
4517 | |
4518 | if (count > MAX_SLABINFO_WRITE) |
4519 | return -EINVAL; |
4520 | if (copy_from_user(&kbuf, buffer, count)) |
4521 | return -EFAULT; |
4522 | kbuf[MAX_SLABINFO_WRITE] = '\0'; |
4523 | |
4524 | tmp = strchr(kbuf, ' '); |
4525 | if (!tmp) |
4526 | return -EINVAL; |
4527 | *tmp = '\0'; |
4528 | tmp++; |
4529 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
4530 | return -EINVAL; |
4531 | |
4532 | /* Find the cache in the chain of caches. */ |
4533 | mutex_lock(&slab_mutex); |
4534 | res = -EINVAL; |
4535 | list_for_each_entry(cachep, &slab_caches, list) { |
4536 | if (!strcmp(cachep->name, kbuf)) { |
4537 | if (limit < 1 || batchcount < 1 || |
4538 | batchcount > limit || shared < 0) { |
4539 | res = 0; |
4540 | } else { |
4541 | res = do_tune_cpucache(cachep, limit, |
4542 | batchcount, shared, |
4543 | GFP_KERNEL); |
4544 | } |
4545 | break; |
4546 | } |
4547 | } |
4548 | mutex_unlock(&slab_mutex); |
4549 | if (res >= 0) |
4550 | res = count; |
4551 | return res; |
4552 | } |
4553 | |
4554 | static int slabinfo_open(struct inode *inode, struct file *file) |
4555 | { |
4556 | return seq_open(file, &slabinfo_op); |
4557 | } |
4558 | |
4559 | static const struct file_operations proc_slabinfo_operations = { |
4560 | .open = slabinfo_open, |
4561 | .read = seq_read, |
4562 | .write = slabinfo_write, |
4563 | .llseek = seq_lseek, |
4564 | .release = seq_release, |
4565 | }; |
4566 | |
4567 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4568 | |
4569 | static void *leaks_start(struct seq_file *m, loff_t *pos) |
4570 | { |
4571 | mutex_lock(&slab_mutex); |
4572 | return seq_list_start(&slab_caches, *pos); |
4573 | } |
4574 | |
4575 | static inline int add_caller(unsigned long *n, unsigned long v) |
4576 | { |
4577 | unsigned long *p; |
4578 | int l; |
4579 | if (!v) |
4580 | return 1; |
4581 | l = n[1]; |
4582 | p = n + 2; |
4583 | while (l) { |
4584 | int i = l/2; |
4585 | unsigned long *q = p + 2 * i; |
4586 | if (*q == v) { |
4587 | q[1]++; |
4588 | return 1; |
4589 | } |
4590 | if (*q > v) { |
4591 | l = i; |
4592 | } else { |
4593 | p = q + 2; |
4594 | l -= i + 1; |
4595 | } |
4596 | } |
4597 | if (++n[1] == n[0]) |
4598 | return 0; |
4599 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); |
4600 | p[0] = v; |
4601 | p[1] = 1; |
4602 | return 1; |
4603 | } |
4604 | |
4605 | static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s) |
4606 | { |
4607 | void *p; |
4608 | int i; |
4609 | if (n[0] == n[1]) |
4610 | return; |
4611 | for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) { |
4612 | if (slab_bufctl(s)[i] != BUFCTL_ACTIVE) |
4613 | continue; |
4614 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) |
4615 | return; |
4616 | } |
4617 | } |
4618 | |
4619 | static void show_symbol(struct seq_file *m, unsigned long address) |
4620 | { |
4621 | #ifdef CONFIG_KALLSYMS |
4622 | unsigned long offset, size; |
4623 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; |
4624 | |
4625 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { |
4626 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); |
4627 | if (modname[0]) |
4628 | seq_printf(m, " [%s]", modname); |
4629 | return; |
4630 | } |
4631 | #endif |
4632 | seq_printf(m, "%p", (void *)address); |
4633 | } |
4634 | |
4635 | static int leaks_show(struct seq_file *m, void *p) |
4636 | { |
4637 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); |
4638 | struct slab *slabp; |
4639 | struct kmem_list3 *l3; |
4640 | const char *name; |
4641 | unsigned long *n = m->private; |
4642 | int node; |
4643 | int i; |
4644 | |
4645 | if (!(cachep->flags & SLAB_STORE_USER)) |
4646 | return 0; |
4647 | if (!(cachep->flags & SLAB_RED_ZONE)) |
4648 | return 0; |
4649 | |
4650 | /* OK, we can do it */ |
4651 | |
4652 | n[1] = 0; |
4653 | |
4654 | for_each_online_node(node) { |
4655 | l3 = cachep->nodelists[node]; |
4656 | if (!l3) |
4657 | continue; |
4658 | |
4659 | check_irq_on(); |
4660 | spin_lock_irq(&l3->list_lock); |
4661 | |
4662 | list_for_each_entry(slabp, &l3->slabs_full, list) |
4663 | handle_slab(n, cachep, slabp); |
4664 | list_for_each_entry(slabp, &l3->slabs_partial, list) |
4665 | handle_slab(n, cachep, slabp); |
4666 | spin_unlock_irq(&l3->list_lock); |
4667 | } |
4668 | name = cachep->name; |
4669 | if (n[0] == n[1]) { |
4670 | /* Increase the buffer size */ |
4671 | mutex_unlock(&slab_mutex); |
4672 | m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL); |
4673 | if (!m->private) { |
4674 | /* Too bad, we are really out */ |
4675 | m->private = n; |
4676 | mutex_lock(&slab_mutex); |
4677 | return -ENOMEM; |
4678 | } |
4679 | *(unsigned long *)m->private = n[0] * 2; |
4680 | kfree(n); |
4681 | mutex_lock(&slab_mutex); |
4682 | /* Now make sure this entry will be retried */ |
4683 | m->count = m->size; |
4684 | return 0; |
4685 | } |
4686 | for (i = 0; i < n[1]; i++) { |
4687 | seq_printf(m, "%s: %lu ", name, n[2*i+3]); |
4688 | show_symbol(m, n[2*i+2]); |
4689 | seq_putc(m, '\n'); |
4690 | } |
4691 | |
4692 | return 0; |
4693 | } |
4694 | |
4695 | static const struct seq_operations slabstats_op = { |
4696 | .start = leaks_start, |
4697 | .next = s_next, |
4698 | .stop = s_stop, |
4699 | .show = leaks_show, |
4700 | }; |
4701 | |
4702 | static int slabstats_open(struct inode *inode, struct file *file) |
4703 | { |
4704 | unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); |
4705 | int ret = -ENOMEM; |
4706 | if (n) { |
4707 | ret = seq_open(file, &slabstats_op); |
4708 | if (!ret) { |
4709 | struct seq_file *m = file->private_data; |
4710 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); |
4711 | m->private = n; |
4712 | n = NULL; |
4713 | } |
4714 | kfree(n); |
4715 | } |
4716 | return ret; |
4717 | } |
4718 | |
4719 | static const struct file_operations proc_slabstats_operations = { |
4720 | .open = slabstats_open, |
4721 | .read = seq_read, |
4722 | .llseek = seq_lseek, |
4723 | .release = seq_release_private, |
4724 | }; |
4725 | #endif |
4726 | |
4727 | static int __init slab_proc_init(void) |
4728 | { |
4729 | proc_create("slabinfo",S_IWUSR|S_IRUSR,NULL,&proc_slabinfo_operations); |
4730 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4731 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); |
4732 | #endif |
4733 | return 0; |
4734 | } |
4735 | module_init(slab_proc_init); |
4736 | #endif |
4737 | |
4738 | /** |
4739 | * ksize - get the actual amount of memory allocated for a given object |
4740 | * @objp: Pointer to the object |
4741 | * |
4742 | * kmalloc may internally round up allocations and return more memory |
4743 | * than requested. ksize() can be used to determine the actual amount of |
4744 | * memory allocated. The caller may use this additional memory, even though |
4745 | * a smaller amount of memory was initially specified with the kmalloc call. |
4746 | * The caller must guarantee that objp points to a valid object previously |
4747 | * allocated with either kmalloc() or kmem_cache_alloc(). The object |
4748 | * must not be freed during the duration of the call. |
4749 | */ |
4750 | size_t ksize(const void *objp) |
4751 | { |
4752 | BUG_ON(!objp); |
4753 | if (unlikely(objp == ZERO_SIZE_PTR)) |
4754 | return 0; |
4755 | |
4756 | return virt_to_cache(objp)->object_size; |
4757 | } |
4758 | EXPORT_SYMBOL(ksize); |
4759 |
Branches:
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javiroman/ks7010
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9