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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 'cache_chain_mutex'. |
72 | * The sem is only needed when accessing/extending the cache-chain, which |
73 | * can never happen inside an interrupt (kmem_cache_create(), |
74 | * kmem_cache_shrink() and kmem_cache_reap()). |
75 | * |
76 | * At present, each engine can be growing a cache. This should be blocked. |
77 | * |
78 | * 15 March 2005. NUMA slab allocator. |
79 | * Shai Fultheim <shai@scalex86.org>. |
80 | * Shobhit Dayal <shobhit@calsoftinc.com> |
81 | * Alok N Kataria <alokk@calsoftinc.com> |
82 | * Christoph Lameter <christoph@lameter.com> |
83 | * |
84 | * Modified the slab allocator to be node aware on NUMA systems. |
85 | * Each node has its own list of partial, free and full slabs. |
86 | * All object allocations for a node occur from node specific slab lists. |
87 | */ |
88 | |
89 | #include <linux/slab.h> |
90 | #include <linux/mm.h> |
91 | #include <linux/poison.h> |
92 | #include <linux/swap.h> |
93 | #include <linux/cache.h> |
94 | #include <linux/interrupt.h> |
95 | #include <linux/init.h> |
96 | #include <linux/compiler.h> |
97 | #include <linux/cpuset.h> |
98 | #include <linux/proc_fs.h> |
99 | #include <linux/seq_file.h> |
100 | #include <linux/notifier.h> |
101 | #include <linux/kallsyms.h> |
102 | #include <linux/cpu.h> |
103 | #include <linux/sysctl.h> |
104 | #include <linux/module.h> |
105 | #include <linux/rcupdate.h> |
106 | #include <linux/string.h> |
107 | #include <linux/uaccess.h> |
108 | #include <linux/nodemask.h> |
109 | #include <linux/kmemleak.h> |
110 | #include <linux/mempolicy.h> |
111 | #include <linux/mutex.h> |
112 | #include <linux/fault-inject.h> |
113 | #include <linux/rtmutex.h> |
114 | #include <linux/reciprocal_div.h> |
115 | #include <linux/debugobjects.h> |
116 | #include <linux/kmemcheck.h> |
117 | #include <linux/memory.h> |
118 | #include <linux/prefetch.h> |
119 | |
120 | #include <asm/cacheflush.h> |
121 | #include <asm/tlbflush.h> |
122 | #include <asm/page.h> |
123 | |
124 | /* |
125 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. |
126 | * 0 for faster, smaller code (especially in the critical paths). |
127 | * |
128 | * STATS - 1 to collect stats for /proc/slabinfo. |
129 | * 0 for faster, smaller code (especially in the critical paths). |
130 | * |
131 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) |
132 | */ |
133 | |
134 | #ifdef CONFIG_DEBUG_SLAB |
135 | #define DEBUG 1 |
136 | #define STATS 1 |
137 | #define FORCED_DEBUG 1 |
138 | #else |
139 | #define DEBUG 0 |
140 | #define STATS 0 |
141 | #define FORCED_DEBUG 0 |
142 | #endif |
143 | |
144 | /* Shouldn't this be in a header file somewhere? */ |
145 | #define BYTES_PER_WORD sizeof(void *) |
146 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) |
147 | |
148 | #ifndef ARCH_KMALLOC_FLAGS |
149 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN |
150 | #endif |
151 | |
152 | /* Legal flag mask for kmem_cache_create(). */ |
153 | #if DEBUG |
154 | # define CREATE_MASK (SLAB_RED_ZONE | \ |
155 | SLAB_POISON | SLAB_HWCACHE_ALIGN | \ |
156 | SLAB_CACHE_DMA | \ |
157 | SLAB_STORE_USER | \ |
158 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
159 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ |
160 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) |
161 | #else |
162 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ |
163 | SLAB_CACHE_DMA | \ |
164 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
165 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ |
166 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) |
167 | #endif |
168 | |
169 | /* |
170 | * kmem_bufctl_t: |
171 | * |
172 | * Bufctl's are used for linking objs within a slab |
173 | * linked offsets. |
174 | * |
175 | * This implementation relies on "struct page" for locating the cache & |
176 | * slab an object belongs to. |
177 | * This allows the bufctl structure to be small (one int), but limits |
178 | * the number of objects a slab (not a cache) can contain when off-slab |
179 | * bufctls are used. The limit is the size of the largest general cache |
180 | * that does not use off-slab slabs. |
181 | * For 32bit archs with 4 kB pages, is this 56. |
182 | * This is not serious, as it is only for large objects, when it is unwise |
183 | * to have too many per slab. |
184 | * Note: This limit can be raised by introducing a general cache whose size |
185 | * is less than 512 (PAGE_SIZE<<3), but greater than 256. |
186 | */ |
187 | |
188 | typedef unsigned int kmem_bufctl_t; |
189 | #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) |
190 | #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) |
191 | #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) |
192 | #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) |
193 | |
194 | /* |
195 | * struct slab_rcu |
196 | * |
197 | * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to |
198 | * arrange for kmem_freepages to be called via RCU. This is useful if |
199 | * we need to approach a kernel structure obliquely, from its address |
200 | * obtained without the usual locking. We can lock the structure to |
201 | * stabilize it and check it's still at the given address, only if we |
202 | * can be sure that the memory has not been meanwhile reused for some |
203 | * other kind of object (which our subsystem's lock might corrupt). |
204 | * |
205 | * rcu_read_lock before reading the address, then rcu_read_unlock after |
206 | * taking the spinlock within the structure expected at that address. |
207 | */ |
208 | struct slab_rcu { |
209 | struct rcu_head head; |
210 | struct kmem_cache *cachep; |
211 | void *addr; |
212 | }; |
213 | |
214 | /* |
215 | * struct slab |
216 | * |
217 | * Manages the objs in a slab. Placed either at the beginning of mem allocated |
218 | * for a slab, or allocated from an general cache. |
219 | * Slabs are chained into three list: fully used, partial, fully free slabs. |
220 | */ |
221 | struct slab { |
222 | union { |
223 | struct { |
224 | struct list_head list; |
225 | unsigned long colouroff; |
226 | void *s_mem; /* including colour offset */ |
227 | unsigned int inuse; /* num of objs active in slab */ |
228 | kmem_bufctl_t free; |
229 | unsigned short nodeid; |
230 | }; |
231 | struct slab_rcu __slab_cover_slab_rcu; |
232 | }; |
233 | }; |
234 | |
235 | /* |
236 | * struct array_cache |
237 | * |
238 | * Purpose: |
239 | * - LIFO ordering, to hand out cache-warm objects from _alloc |
240 | * - reduce the number of linked list operations |
241 | * - reduce spinlock operations |
242 | * |
243 | * The limit is stored in the per-cpu structure to reduce the data cache |
244 | * footprint. |
245 | * |
246 | */ |
247 | struct array_cache { |
248 | unsigned int avail; |
249 | unsigned int limit; |
250 | unsigned int batchcount; |
251 | unsigned int touched; |
252 | spinlock_t lock; |
253 | void *entry[]; /* |
254 | * Must have this definition in here for the proper |
255 | * alignment of array_cache. Also simplifies accessing |
256 | * the entries. |
257 | */ |
258 | }; |
259 | |
260 | /* |
261 | * bootstrap: The caches do not work without cpuarrays anymore, but the |
262 | * cpuarrays are allocated from the generic caches... |
263 | */ |
264 | #define BOOT_CPUCACHE_ENTRIES 1 |
265 | struct arraycache_init { |
266 | struct array_cache cache; |
267 | void *entries[BOOT_CPUCACHE_ENTRIES]; |
268 | }; |
269 | |
270 | /* |
271 | * The slab lists for all objects. |
272 | */ |
273 | struct kmem_list3 { |
274 | struct list_head slabs_partial; /* partial list first, better asm code */ |
275 | struct list_head slabs_full; |
276 | struct list_head slabs_free; |
277 | unsigned long free_objects; |
278 | unsigned int free_limit; |
279 | unsigned int colour_next; /* Per-node cache coloring */ |
280 | spinlock_t list_lock; |
281 | struct array_cache *shared; /* shared per node */ |
282 | struct array_cache **alien; /* on other nodes */ |
283 | unsigned long next_reap; /* updated without locking */ |
284 | int free_touched; /* updated without locking */ |
285 | }; |
286 | |
287 | /* |
288 | * Need this for bootstrapping a per node allocator. |
289 | */ |
290 | #define NUM_INIT_LISTS (3 * MAX_NUMNODES) |
291 | static struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; |
292 | #define CACHE_CACHE 0 |
293 | #define SIZE_AC MAX_NUMNODES |
294 | #define SIZE_L3 (2 * MAX_NUMNODES) |
295 | |
296 | static int drain_freelist(struct kmem_cache *cache, |
297 | struct kmem_list3 *l3, int tofree); |
298 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, |
299 | int node); |
300 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); |
301 | static void cache_reap(struct work_struct *unused); |
302 | |
303 | /* |
304 | * This function must be completely optimized away if a constant is passed to |
305 | * it. Mostly the same as what is in linux/slab.h except it returns an index. |
306 | */ |
307 | static __always_inline int index_of(const size_t size) |
308 | { |
309 | extern void __bad_size(void); |
310 | |
311 | if (__builtin_constant_p(size)) { |
312 | int i = 0; |
313 | |
314 | #define CACHE(x) \ |
315 | if (size <=x) \ |
316 | return i; \ |
317 | else \ |
318 | i++; |
319 | #include <linux/kmalloc_sizes.h> |
320 | #undef CACHE |
321 | __bad_size(); |
322 | } else |
323 | __bad_size(); |
324 | return 0; |
325 | } |
326 | |
327 | static int slab_early_init = 1; |
328 | |
329 | #define INDEX_AC index_of(sizeof(struct arraycache_init)) |
330 | #define INDEX_L3 index_of(sizeof(struct kmem_list3)) |
331 | |
332 | static void kmem_list3_init(struct kmem_list3 *parent) |
333 | { |
334 | INIT_LIST_HEAD(&parent->slabs_full); |
335 | INIT_LIST_HEAD(&parent->slabs_partial); |
336 | INIT_LIST_HEAD(&parent->slabs_free); |
337 | parent->shared = NULL; |
338 | parent->alien = NULL; |
339 | parent->colour_next = 0; |
340 | spin_lock_init(&parent->list_lock); |
341 | parent->free_objects = 0; |
342 | parent->free_touched = 0; |
343 | } |
344 | |
345 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ |
346 | do { \ |
347 | INIT_LIST_HEAD(listp); \ |
348 | list_splice(&(cachep->nodelists[nodeid]->slab), listp); \ |
349 | } while (0) |
350 | |
351 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ |
352 | do { \ |
353 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ |
354 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ |
355 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ |
356 | } while (0) |
357 | |
358 | #define CFLGS_OFF_SLAB (0x80000000UL) |
359 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
360 | |
361 | #define BATCHREFILL_LIMIT 16 |
362 | /* |
363 | * Optimization question: fewer reaps means less probability for unnessary |
364 | * cpucache drain/refill cycles. |
365 | * |
366 | * OTOH the cpuarrays can contain lots of objects, |
367 | * which could lock up otherwise freeable slabs. |
368 | */ |
369 | #define REAPTIMEOUT_CPUC (2*HZ) |
370 | #define REAPTIMEOUT_LIST3 (4*HZ) |
371 | |
372 | #if STATS |
373 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
374 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
375 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
376 | #define STATS_INC_GROWN(x) ((x)->grown++) |
377 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) |
378 | #define STATS_SET_HIGH(x) \ |
379 | do { \ |
380 | if ((x)->num_active > (x)->high_mark) \ |
381 | (x)->high_mark = (x)->num_active; \ |
382 | } while (0) |
383 | #define STATS_INC_ERR(x) ((x)->errors++) |
384 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
385 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
386 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) |
387 | #define STATS_SET_FREEABLE(x, i) \ |
388 | do { \ |
389 | if ((x)->max_freeable < i) \ |
390 | (x)->max_freeable = i; \ |
391 | } while (0) |
392 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
393 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
394 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
395 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
396 | #else |
397 | #define STATS_INC_ACTIVE(x) do { } while (0) |
398 | #define STATS_DEC_ACTIVE(x) do { } while (0) |
399 | #define STATS_INC_ALLOCED(x) do { } while (0) |
400 | #define STATS_INC_GROWN(x) do { } while (0) |
401 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) |
402 | #define STATS_SET_HIGH(x) do { } while (0) |
403 | #define STATS_INC_ERR(x) do { } while (0) |
404 | #define STATS_INC_NODEALLOCS(x) do { } while (0) |
405 | #define STATS_INC_NODEFREES(x) do { } while (0) |
406 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) |
407 | #define STATS_SET_FREEABLE(x, i) do { } while (0) |
408 | #define STATS_INC_ALLOCHIT(x) do { } while (0) |
409 | #define STATS_INC_ALLOCMISS(x) do { } while (0) |
410 | #define STATS_INC_FREEHIT(x) do { } while (0) |
411 | #define STATS_INC_FREEMISS(x) do { } while (0) |
412 | #endif |
413 | |
414 | #if DEBUG |
415 | |
416 | /* |
417 | * memory layout of objects: |
418 | * 0 : objp |
419 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that |
420 | * the end of an object is aligned with the end of the real |
421 | * allocation. Catches writes behind the end of the allocation. |
422 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: |
423 | * redzone word. |
424 | * cachep->obj_offset: The real object. |
425 | * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
426 | * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address |
427 | * [BYTES_PER_WORD long] |
428 | */ |
429 | static int obj_offset(struct kmem_cache *cachep) |
430 | { |
431 | return cachep->obj_offset; |
432 | } |
433 | |
434 | static int obj_size(struct kmem_cache *cachep) |
435 | { |
436 | return cachep->obj_size; |
437 | } |
438 | |
439 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) |
440 | { |
441 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
442 | return (unsigned long long*) (objp + obj_offset(cachep) - |
443 | sizeof(unsigned long long)); |
444 | } |
445 | |
446 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) |
447 | { |
448 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
449 | if (cachep->flags & SLAB_STORE_USER) |
450 | return (unsigned long long *)(objp + cachep->buffer_size - |
451 | sizeof(unsigned long long) - |
452 | REDZONE_ALIGN); |
453 | return (unsigned long long *) (objp + cachep->buffer_size - |
454 | sizeof(unsigned long long)); |
455 | } |
456 | |
457 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) |
458 | { |
459 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
460 | return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD); |
461 | } |
462 | |
463 | #else |
464 | |
465 | #define obj_offset(x) 0 |
466 | #define obj_size(cachep) (cachep->buffer_size) |
467 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
468 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
469 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
470 | |
471 | #endif |
472 | |
473 | #ifdef CONFIG_TRACING |
474 | size_t slab_buffer_size(struct kmem_cache *cachep) |
475 | { |
476 | return cachep->buffer_size; |
477 | } |
478 | EXPORT_SYMBOL(slab_buffer_size); |
479 | #endif |
480 | |
481 | /* |
482 | * Do not go above this order unless 0 objects fit into the slab. |
483 | */ |
484 | #define BREAK_GFP_ORDER_HI 1 |
485 | #define BREAK_GFP_ORDER_LO 0 |
486 | static int slab_break_gfp_order = BREAK_GFP_ORDER_LO; |
487 | |
488 | /* |
489 | * Functions for storing/retrieving the cachep and or slab from the page |
490 | * allocator. These are used to find the slab an obj belongs to. With kfree(), |
491 | * these are used to find the cache which an obj belongs to. |
492 | */ |
493 | static inline void page_set_cache(struct page *page, struct kmem_cache *cache) |
494 | { |
495 | page->lru.next = (struct list_head *)cache; |
496 | } |
497 | |
498 | static inline struct kmem_cache *page_get_cache(struct page *page) |
499 | { |
500 | page = compound_head(page); |
501 | BUG_ON(!PageSlab(page)); |
502 | return (struct kmem_cache *)page->lru.next; |
503 | } |
504 | |
505 | static inline void page_set_slab(struct page *page, struct slab *slab) |
506 | { |
507 | page->lru.prev = (struct list_head *)slab; |
508 | } |
509 | |
510 | static inline struct slab *page_get_slab(struct page *page) |
511 | { |
512 | BUG_ON(!PageSlab(page)); |
513 | return (struct slab *)page->lru.prev; |
514 | } |
515 | |
516 | static inline struct kmem_cache *virt_to_cache(const void *obj) |
517 | { |
518 | struct page *page = virt_to_head_page(obj); |
519 | return page_get_cache(page); |
520 | } |
521 | |
522 | static inline struct slab *virt_to_slab(const void *obj) |
523 | { |
524 | struct page *page = virt_to_head_page(obj); |
525 | return page_get_slab(page); |
526 | } |
527 | |
528 | static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, |
529 | unsigned int idx) |
530 | { |
531 | return slab->s_mem + cache->buffer_size * idx; |
532 | } |
533 | |
534 | /* |
535 | * We want to avoid an expensive divide : (offset / cache->buffer_size) |
536 | * Using the fact that buffer_size is a constant for a particular cache, |
537 | * we can replace (offset / cache->buffer_size) by |
538 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) |
539 | */ |
540 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, |
541 | const struct slab *slab, void *obj) |
542 | { |
543 | u32 offset = (obj - slab->s_mem); |
544 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); |
545 | } |
546 | |
547 | /* |
548 | * These are the default caches for kmalloc. Custom caches can have other sizes. |
549 | */ |
550 | struct cache_sizes malloc_sizes[] = { |
551 | #define CACHE(x) { .cs_size = (x) }, |
552 | #include <linux/kmalloc_sizes.h> |
553 | CACHE(ULONG_MAX) |
554 | #undef CACHE |
555 | }; |
556 | EXPORT_SYMBOL(malloc_sizes); |
557 | |
558 | /* Must match cache_sizes above. Out of line to keep cache footprint low. */ |
559 | struct cache_names { |
560 | char *name; |
561 | char *name_dma; |
562 | }; |
563 | |
564 | static struct cache_names __initdata cache_names[] = { |
565 | #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" }, |
566 | #include <linux/kmalloc_sizes.h> |
567 | {NULL,} |
568 | #undef CACHE |
569 | }; |
570 | |
571 | static struct arraycache_init initarray_cache __initdata = |
572 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
573 | static struct arraycache_init initarray_generic = |
574 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
575 | |
576 | /* internal cache of cache description objs */ |
577 | static struct kmem_list3 *cache_cache_nodelists[MAX_NUMNODES]; |
578 | static struct kmem_cache cache_cache = { |
579 | .nodelists = cache_cache_nodelists, |
580 | .batchcount = 1, |
581 | .limit = BOOT_CPUCACHE_ENTRIES, |
582 | .shared = 1, |
583 | .buffer_size = sizeof(struct kmem_cache), |
584 | .name = "kmem_cache", |
585 | }; |
586 | |
587 | #define BAD_ALIEN_MAGIC 0x01020304ul |
588 | |
589 | /* |
590 | * chicken and egg problem: delay the per-cpu array allocation |
591 | * until the general caches are up. |
592 | */ |
593 | static enum { |
594 | NONE, |
595 | PARTIAL_AC, |
596 | PARTIAL_L3, |
597 | EARLY, |
598 | FULL |
599 | } g_cpucache_up; |
600 | |
601 | /* |
602 | * used by boot code to determine if it can use slab based allocator |
603 | */ |
604 | int slab_is_available(void) |
605 | { |
606 | return g_cpucache_up >= EARLY; |
607 | } |
608 | |
609 | #ifdef CONFIG_LOCKDEP |
610 | |
611 | /* |
612 | * Slab sometimes uses the kmalloc slabs to store the slab headers |
613 | * for other slabs "off slab". |
614 | * The locking for this is tricky in that it nests within the locks |
615 | * of all other slabs in a few places; to deal with this special |
616 | * locking we put on-slab caches into a separate lock-class. |
617 | * |
618 | * We set lock class for alien array caches which are up during init. |
619 | * The lock annotation will be lost if all cpus of a node goes down and |
620 | * then comes back up during hotplug |
621 | */ |
622 | static struct lock_class_key on_slab_l3_key; |
623 | static struct lock_class_key on_slab_alc_key; |
624 | |
625 | static struct lock_class_key debugobj_l3_key; |
626 | static struct lock_class_key debugobj_alc_key; |
627 | |
628 | static void slab_set_lock_classes(struct kmem_cache *cachep, |
629 | struct lock_class_key *l3_key, struct lock_class_key *alc_key, |
630 | int q) |
631 | { |
632 | struct array_cache **alc; |
633 | struct kmem_list3 *l3; |
634 | int r; |
635 | |
636 | l3 = cachep->nodelists[q]; |
637 | if (!l3) |
638 | return; |
639 | |
640 | lockdep_set_class(&l3->list_lock, l3_key); |
641 | alc = l3->alien; |
642 | /* |
643 | * FIXME: This check for BAD_ALIEN_MAGIC |
644 | * should go away when common slab code is taught to |
645 | * work even without alien caches. |
646 | * Currently, non NUMA code returns BAD_ALIEN_MAGIC |
647 | * for alloc_alien_cache, |
648 | */ |
649 | if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) |
650 | return; |
651 | for_each_node(r) { |
652 | if (alc[r]) |
653 | lockdep_set_class(&alc[r]->lock, alc_key); |
654 | } |
655 | } |
656 | |
657 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
658 | { |
659 | slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node); |
660 | } |
661 | |
662 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
663 | { |
664 | int node; |
665 | |
666 | for_each_online_node(node) |
667 | slab_set_debugobj_lock_classes_node(cachep, node); |
668 | } |
669 | |
670 | static void init_node_lock_keys(int q) |
671 | { |
672 | struct cache_sizes *s = malloc_sizes; |
673 | |
674 | if (g_cpucache_up != FULL) |
675 | return; |
676 | |
677 | for (s = malloc_sizes; s->cs_size != ULONG_MAX; s++) { |
678 | struct kmem_list3 *l3; |
679 | |
680 | l3 = s->cs_cachep->nodelists[q]; |
681 | if (!l3 || OFF_SLAB(s->cs_cachep)) |
682 | continue; |
683 | |
684 | slab_set_lock_classes(s->cs_cachep, &on_slab_l3_key, |
685 | &on_slab_alc_key, q); |
686 | } |
687 | } |
688 | |
689 | static inline void init_lock_keys(void) |
690 | { |
691 | int node; |
692 | |
693 | for_each_node(node) |
694 | init_node_lock_keys(node); |
695 | } |
696 | #else |
697 | static void init_node_lock_keys(int q) |
698 | { |
699 | } |
700 | |
701 | static inline void init_lock_keys(void) |
702 | { |
703 | } |
704 | |
705 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) |
706 | { |
707 | } |
708 | |
709 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) |
710 | { |
711 | } |
712 | #endif |
713 | |
714 | /* |
715 | * Guard access to the cache-chain. |
716 | */ |
717 | static DEFINE_MUTEX(cache_chain_mutex); |
718 | static struct list_head cache_chain; |
719 | |
720 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); |
721 | |
722 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) |
723 | { |
724 | return cachep->array[smp_processor_id()]; |
725 | } |
726 | |
727 | static inline struct kmem_cache *__find_general_cachep(size_t size, |
728 | gfp_t gfpflags) |
729 | { |
730 | struct cache_sizes *csizep = malloc_sizes; |
731 | |
732 | #if DEBUG |
733 | /* This happens if someone tries to call |
734 | * kmem_cache_create(), or __kmalloc(), before |
735 | * the generic caches are initialized. |
736 | */ |
737 | BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); |
738 | #endif |
739 | if (!size) |
740 | return ZERO_SIZE_PTR; |
741 | |
742 | while (size > csizep->cs_size) |
743 | csizep++; |
744 | |
745 | /* |
746 | * Really subtle: The last entry with cs->cs_size==ULONG_MAX |
747 | * has cs_{dma,}cachep==NULL. Thus no special case |
748 | * for large kmalloc calls required. |
749 | */ |
750 | #ifdef CONFIG_ZONE_DMA |
751 | if (unlikely(gfpflags & GFP_DMA)) |
752 | return csizep->cs_dmacachep; |
753 | #endif |
754 | return csizep->cs_cachep; |
755 | } |
756 | |
757 | static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) |
758 | { |
759 | return __find_general_cachep(size, gfpflags); |
760 | } |
761 | |
762 | static size_t slab_mgmt_size(size_t nr_objs, size_t align) |
763 | { |
764 | return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); |
765 | } |
766 | |
767 | /* |
768 | * Calculate the number of objects and left-over bytes for a given buffer size. |
769 | */ |
770 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, |
771 | size_t align, int flags, size_t *left_over, |
772 | unsigned int *num) |
773 | { |
774 | int nr_objs; |
775 | size_t mgmt_size; |
776 | size_t slab_size = PAGE_SIZE << gfporder; |
777 | |
778 | /* |
779 | * The slab management structure can be either off the slab or |
780 | * on it. For the latter case, the memory allocated for a |
781 | * slab is used for: |
782 | * |
783 | * - The struct slab |
784 | * - One kmem_bufctl_t for each object |
785 | * - Padding to respect alignment of @align |
786 | * - @buffer_size bytes for each object |
787 | * |
788 | * If the slab management structure is off the slab, then the |
789 | * alignment will already be calculated into the size. Because |
790 | * the slabs are all pages aligned, the objects will be at the |
791 | * correct alignment when allocated. |
792 | */ |
793 | if (flags & CFLGS_OFF_SLAB) { |
794 | mgmt_size = 0; |
795 | nr_objs = slab_size / buffer_size; |
796 | |
797 | if (nr_objs > SLAB_LIMIT) |
798 | nr_objs = SLAB_LIMIT; |
799 | } else { |
800 | /* |
801 | * Ignore padding for the initial guess. The padding |
802 | * is at most @align-1 bytes, and @buffer_size is at |
803 | * least @align. In the worst case, this result will |
804 | * be one greater than the number of objects that fit |
805 | * into the memory allocation when taking the padding |
806 | * into account. |
807 | */ |
808 | nr_objs = (slab_size - sizeof(struct slab)) / |
809 | (buffer_size + sizeof(kmem_bufctl_t)); |
810 | |
811 | /* |
812 | * This calculated number will be either the right |
813 | * amount, or one greater than what we want. |
814 | */ |
815 | if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size |
816 | > slab_size) |
817 | nr_objs--; |
818 | |
819 | if (nr_objs > SLAB_LIMIT) |
820 | nr_objs = SLAB_LIMIT; |
821 | |
822 | mgmt_size = slab_mgmt_size(nr_objs, align); |
823 | } |
824 | *num = nr_objs; |
825 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; |
826 | } |
827 | |
828 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) |
829 | |
830 | static void __slab_error(const char *function, struct kmem_cache *cachep, |
831 | char *msg) |
832 | { |
833 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
834 | function, cachep->name, msg); |
835 | dump_stack(); |
836 | } |
837 | |
838 | /* |
839 | * By default on NUMA we use alien caches to stage the freeing of |
840 | * objects allocated from other nodes. This causes massive memory |
841 | * inefficiencies when using fake NUMA setup to split memory into a |
842 | * large number of small nodes, so it can be disabled on the command |
843 | * line |
844 | */ |
845 | |
846 | static int use_alien_caches __read_mostly = 1; |
847 | static int __init noaliencache_setup(char *s) |
848 | { |
849 | use_alien_caches = 0; |
850 | return 1; |
851 | } |
852 | __setup("noaliencache", noaliencache_setup); |
853 | |
854 | #ifdef CONFIG_NUMA |
855 | /* |
856 | * Special reaping functions for NUMA systems called from cache_reap(). |
857 | * These take care of doing round robin flushing of alien caches (containing |
858 | * objects freed on different nodes from which they were allocated) and the |
859 | * flushing of remote pcps by calling drain_node_pages. |
860 | */ |
861 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); |
862 | |
863 | static void init_reap_node(int cpu) |
864 | { |
865 | int node; |
866 | |
867 | node = next_node(cpu_to_mem(cpu), node_online_map); |
868 | if (node == MAX_NUMNODES) |
869 | node = first_node(node_online_map); |
870 | |
871 | per_cpu(slab_reap_node, cpu) = node; |
872 | } |
873 | |
874 | static void next_reap_node(void) |
875 | { |
876 | int node = __this_cpu_read(slab_reap_node); |
877 | |
878 | node = next_node(node, node_online_map); |
879 | if (unlikely(node >= MAX_NUMNODES)) |
880 | node = first_node(node_online_map); |
881 | __this_cpu_write(slab_reap_node, node); |
882 | } |
883 | |
884 | #else |
885 | #define init_reap_node(cpu) do { } while (0) |
886 | #define next_reap_node(void) do { } while (0) |
887 | #endif |
888 | |
889 | /* |
890 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
891 | * via the workqueue/eventd. |
892 | * Add the CPU number into the expiration time to minimize the possibility of |
893 | * the CPUs getting into lockstep and contending for the global cache chain |
894 | * lock. |
895 | */ |
896 | static void __cpuinit start_cpu_timer(int cpu) |
897 | { |
898 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); |
899 | |
900 | /* |
901 | * When this gets called from do_initcalls via cpucache_init(), |
902 | * init_workqueues() has already run, so keventd will be setup |
903 | * at that time. |
904 | */ |
905 | if (keventd_up() && reap_work->work.func == NULL) { |
906 | init_reap_node(cpu); |
907 | INIT_DELAYED_WORK_DEFERRABLE(reap_work, cache_reap); |
908 | schedule_delayed_work_on(cpu, reap_work, |
909 | __round_jiffies_relative(HZ, cpu)); |
910 | } |
911 | } |
912 | |
913 | static struct array_cache *alloc_arraycache(int node, int entries, |
914 | int batchcount, gfp_t gfp) |
915 | { |
916 | int memsize = sizeof(void *) * entries + sizeof(struct array_cache); |
917 | struct array_cache *nc = NULL; |
918 | |
919 | nc = kmalloc_node(memsize, gfp, node); |
920 | /* |
921 | * The array_cache structures contain pointers to free object. |
922 | * However, when such objects are allocated or transferred to another |
923 | * cache the pointers are not cleared and they could be counted as |
924 | * valid references during a kmemleak scan. Therefore, kmemleak must |
925 | * not scan such objects. |
926 | */ |
927 | kmemleak_no_scan(nc); |
928 | if (nc) { |
929 | nc->avail = 0; |
930 | nc->limit = entries; |
931 | nc->batchcount = batchcount; |
932 | nc->touched = 0; |
933 | spin_lock_init(&nc->lock); |
934 | } |
935 | return nc; |
936 | } |
937 | |
938 | /* |
939 | * Transfer objects in one arraycache to another. |
940 | * Locking must be handled by the caller. |
941 | * |
942 | * Return the number of entries transferred. |
943 | */ |
944 | static int transfer_objects(struct array_cache *to, |
945 | struct array_cache *from, unsigned int max) |
946 | { |
947 | /* Figure out how many entries to transfer */ |
948 | int nr = min3(from->avail, max, to->limit - to->avail); |
949 | |
950 | if (!nr) |
951 | return 0; |
952 | |
953 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, |
954 | sizeof(void *) *nr); |
955 | |
956 | from->avail -= nr; |
957 | to->avail += nr; |
958 | return nr; |
959 | } |
960 | |
961 | #ifndef CONFIG_NUMA |
962 | |
963 | #define drain_alien_cache(cachep, alien) do { } while (0) |
964 | #define reap_alien(cachep, l3) do { } while (0) |
965 | |
966 | static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
967 | { |
968 | return (struct array_cache **)BAD_ALIEN_MAGIC; |
969 | } |
970 | |
971 | static inline void free_alien_cache(struct array_cache **ac_ptr) |
972 | { |
973 | } |
974 | |
975 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
976 | { |
977 | return 0; |
978 | } |
979 | |
980 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, |
981 | gfp_t flags) |
982 | { |
983 | return NULL; |
984 | } |
985 | |
986 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, |
987 | gfp_t flags, int nodeid) |
988 | { |
989 | return NULL; |
990 | } |
991 | |
992 | #else /* CONFIG_NUMA */ |
993 | |
994 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); |
995 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); |
996 | |
997 | static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
998 | { |
999 | struct array_cache **ac_ptr; |
1000 | int memsize = sizeof(void *) * nr_node_ids; |
1001 | int i; |
1002 | |
1003 | if (limit > 1) |
1004 | limit = 12; |
1005 | ac_ptr = kzalloc_node(memsize, gfp, node); |
1006 | if (ac_ptr) { |
1007 | for_each_node(i) { |
1008 | if (i == node || !node_online(i)) |
1009 | continue; |
1010 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); |
1011 | if (!ac_ptr[i]) { |
1012 | for (i--; i >= 0; i--) |
1013 | kfree(ac_ptr[i]); |
1014 | kfree(ac_ptr); |
1015 | return NULL; |
1016 | } |
1017 | } |
1018 | } |
1019 | return ac_ptr; |
1020 | } |
1021 | |
1022 | static void free_alien_cache(struct array_cache **ac_ptr) |
1023 | { |
1024 | int i; |
1025 | |
1026 | if (!ac_ptr) |
1027 | return; |
1028 | for_each_node(i) |
1029 | kfree(ac_ptr[i]); |
1030 | kfree(ac_ptr); |
1031 | } |
1032 | |
1033 | static void __drain_alien_cache(struct kmem_cache *cachep, |
1034 | struct array_cache *ac, int node) |
1035 | { |
1036 | struct kmem_list3 *rl3 = cachep->nodelists[node]; |
1037 | |
1038 | if (ac->avail) { |
1039 | spin_lock(&rl3->list_lock); |
1040 | /* |
1041 | * Stuff objects into the remote nodes shared array first. |
1042 | * That way we could avoid the overhead of putting the objects |
1043 | * into the free lists and getting them back later. |
1044 | */ |
1045 | if (rl3->shared) |
1046 | transfer_objects(rl3->shared, ac, ac->limit); |
1047 | |
1048 | free_block(cachep, ac->entry, ac->avail, node); |
1049 | ac->avail = 0; |
1050 | spin_unlock(&rl3->list_lock); |
1051 | } |
1052 | } |
1053 | |
1054 | /* |
1055 | * Called from cache_reap() to regularly drain alien caches round robin. |
1056 | */ |
1057 | static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) |
1058 | { |
1059 | int node = __this_cpu_read(slab_reap_node); |
1060 | |
1061 | if (l3->alien) { |
1062 | struct array_cache *ac = l3->alien[node]; |
1063 | |
1064 | if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { |
1065 | __drain_alien_cache(cachep, ac, node); |
1066 | spin_unlock_irq(&ac->lock); |
1067 | } |
1068 | } |
1069 | } |
1070 | |
1071 | static void drain_alien_cache(struct kmem_cache *cachep, |
1072 | struct array_cache **alien) |
1073 | { |
1074 | int i = 0; |
1075 | struct array_cache *ac; |
1076 | unsigned long flags; |
1077 | |
1078 | for_each_online_node(i) { |
1079 | ac = alien[i]; |
1080 | if (ac) { |
1081 | spin_lock_irqsave(&ac->lock, flags); |
1082 | __drain_alien_cache(cachep, ac, i); |
1083 | spin_unlock_irqrestore(&ac->lock, flags); |
1084 | } |
1085 | } |
1086 | } |
1087 | |
1088 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
1089 | { |
1090 | struct slab *slabp = virt_to_slab(objp); |
1091 | int nodeid = slabp->nodeid; |
1092 | struct kmem_list3 *l3; |
1093 | struct array_cache *alien = NULL; |
1094 | int node; |
1095 | |
1096 | node = numa_mem_id(); |
1097 | |
1098 | /* |
1099 | * Make sure we are not freeing a object from another node to the array |
1100 | * cache on this cpu. |
1101 | */ |
1102 | if (likely(slabp->nodeid == node)) |
1103 | return 0; |
1104 | |
1105 | l3 = cachep->nodelists[node]; |
1106 | STATS_INC_NODEFREES(cachep); |
1107 | if (l3->alien && l3->alien[nodeid]) { |
1108 | alien = l3->alien[nodeid]; |
1109 | spin_lock(&alien->lock); |
1110 | if (unlikely(alien->avail == alien->limit)) { |
1111 | STATS_INC_ACOVERFLOW(cachep); |
1112 | __drain_alien_cache(cachep, alien, nodeid); |
1113 | } |
1114 | alien->entry[alien->avail++] = objp; |
1115 | spin_unlock(&alien->lock); |
1116 | } else { |
1117 | spin_lock(&(cachep->nodelists[nodeid])->list_lock); |
1118 | free_block(cachep, &objp, 1, nodeid); |
1119 | spin_unlock(&(cachep->nodelists[nodeid])->list_lock); |
1120 | } |
1121 | return 1; |
1122 | } |
1123 | #endif |
1124 | |
1125 | /* |
1126 | * Allocates and initializes nodelists for a node on each slab cache, used for |
1127 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_list3 |
1128 | * will be allocated off-node since memory is not yet online for the new node. |
1129 | * When hotplugging memory or a cpu, existing nodelists are not replaced if |
1130 | * already in use. |
1131 | * |
1132 | * Must hold cache_chain_mutex. |
1133 | */ |
1134 | static int init_cache_nodelists_node(int node) |
1135 | { |
1136 | struct kmem_cache *cachep; |
1137 | struct kmem_list3 *l3; |
1138 | const int memsize = sizeof(struct kmem_list3); |
1139 | |
1140 | list_for_each_entry(cachep, &cache_chain, next) { |
1141 | /* |
1142 | * Set up the size64 kmemlist for cpu before we can |
1143 | * begin anything. Make sure some other cpu on this |
1144 | * node has not already allocated this |
1145 | */ |
1146 | if (!cachep->nodelists[node]) { |
1147 | l3 = kmalloc_node(memsize, GFP_KERNEL, node); |
1148 | if (!l3) |
1149 | return -ENOMEM; |
1150 | kmem_list3_init(l3); |
1151 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
1152 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1153 | |
1154 | /* |
1155 | * The l3s don't come and go as CPUs come and |
1156 | * go. cache_chain_mutex is sufficient |
1157 | * protection here. |
1158 | */ |
1159 | cachep->nodelists[node] = l3; |
1160 | } |
1161 | |
1162 | spin_lock_irq(&cachep->nodelists[node]->list_lock); |
1163 | cachep->nodelists[node]->free_limit = |
1164 | (1 + nr_cpus_node(node)) * |
1165 | cachep->batchcount + cachep->num; |
1166 | spin_unlock_irq(&cachep->nodelists[node]->list_lock); |
1167 | } |
1168 | return 0; |
1169 | } |
1170 | |
1171 | static void __cpuinit cpuup_canceled(long cpu) |
1172 | { |
1173 | struct kmem_cache *cachep; |
1174 | struct kmem_list3 *l3 = NULL; |
1175 | int node = cpu_to_mem(cpu); |
1176 | const struct cpumask *mask = cpumask_of_node(node); |
1177 | |
1178 | list_for_each_entry(cachep, &cache_chain, next) { |
1179 | struct array_cache *nc; |
1180 | struct array_cache *shared; |
1181 | struct array_cache **alien; |
1182 | |
1183 | /* cpu is dead; no one can alloc from it. */ |
1184 | nc = cachep->array[cpu]; |
1185 | cachep->array[cpu] = NULL; |
1186 | l3 = cachep->nodelists[node]; |
1187 | |
1188 | if (!l3) |
1189 | goto free_array_cache; |
1190 | |
1191 | spin_lock_irq(&l3->list_lock); |
1192 | |
1193 | /* Free limit for this kmem_list3 */ |
1194 | l3->free_limit -= cachep->batchcount; |
1195 | if (nc) |
1196 | free_block(cachep, nc->entry, nc->avail, node); |
1197 | |
1198 | if (!cpumask_empty(mask)) { |
1199 | spin_unlock_irq(&l3->list_lock); |
1200 | goto free_array_cache; |
1201 | } |
1202 | |
1203 | shared = l3->shared; |
1204 | if (shared) { |
1205 | free_block(cachep, shared->entry, |
1206 | shared->avail, node); |
1207 | l3->shared = NULL; |
1208 | } |
1209 | |
1210 | alien = l3->alien; |
1211 | l3->alien = NULL; |
1212 | |
1213 | spin_unlock_irq(&l3->list_lock); |
1214 | |
1215 | kfree(shared); |
1216 | if (alien) { |
1217 | drain_alien_cache(cachep, alien); |
1218 | free_alien_cache(alien); |
1219 | } |
1220 | free_array_cache: |
1221 | kfree(nc); |
1222 | } |
1223 | /* |
1224 | * In the previous loop, all the objects were freed to |
1225 | * the respective cache's slabs, now we can go ahead and |
1226 | * shrink each nodelist to its limit. |
1227 | */ |
1228 | list_for_each_entry(cachep, &cache_chain, next) { |
1229 | l3 = cachep->nodelists[node]; |
1230 | if (!l3) |
1231 | continue; |
1232 | drain_freelist(cachep, l3, l3->free_objects); |
1233 | } |
1234 | } |
1235 | |
1236 | static int __cpuinit cpuup_prepare(long cpu) |
1237 | { |
1238 | struct kmem_cache *cachep; |
1239 | struct kmem_list3 *l3 = NULL; |
1240 | int node = cpu_to_mem(cpu); |
1241 | int err; |
1242 | |
1243 | /* |
1244 | * We need to do this right in the beginning since |
1245 | * alloc_arraycache's are going to use this list. |
1246 | * kmalloc_node allows us to add the slab to the right |
1247 | * kmem_list3 and not this cpu's kmem_list3 |
1248 | */ |
1249 | err = init_cache_nodelists_node(node); |
1250 | if (err < 0) |
1251 | goto bad; |
1252 | |
1253 | /* |
1254 | * Now we can go ahead with allocating the shared arrays and |
1255 | * array caches |
1256 | */ |
1257 | list_for_each_entry(cachep, &cache_chain, next) { |
1258 | struct array_cache *nc; |
1259 | struct array_cache *shared = NULL; |
1260 | struct array_cache **alien = NULL; |
1261 | |
1262 | nc = alloc_arraycache(node, cachep->limit, |
1263 | cachep->batchcount, GFP_KERNEL); |
1264 | if (!nc) |
1265 | goto bad; |
1266 | if (cachep->shared) { |
1267 | shared = alloc_arraycache(node, |
1268 | cachep->shared * cachep->batchcount, |
1269 | 0xbaadf00d, GFP_KERNEL); |
1270 | if (!shared) { |
1271 | kfree(nc); |
1272 | goto bad; |
1273 | } |
1274 | } |
1275 | if (use_alien_caches) { |
1276 | alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); |
1277 | if (!alien) { |
1278 | kfree(shared); |
1279 | kfree(nc); |
1280 | goto bad; |
1281 | } |
1282 | } |
1283 | cachep->array[cpu] = nc; |
1284 | l3 = cachep->nodelists[node]; |
1285 | BUG_ON(!l3); |
1286 | |
1287 | spin_lock_irq(&l3->list_lock); |
1288 | if (!l3->shared) { |
1289 | /* |
1290 | * We are serialised from CPU_DEAD or |
1291 | * CPU_UP_CANCELLED by the cpucontrol lock |
1292 | */ |
1293 | l3->shared = shared; |
1294 | shared = NULL; |
1295 | } |
1296 | #ifdef CONFIG_NUMA |
1297 | if (!l3->alien) { |
1298 | l3->alien = alien; |
1299 | alien = NULL; |
1300 | } |
1301 | #endif |
1302 | spin_unlock_irq(&l3->list_lock); |
1303 | kfree(shared); |
1304 | free_alien_cache(alien); |
1305 | if (cachep->flags & SLAB_DEBUG_OBJECTS) |
1306 | slab_set_debugobj_lock_classes_node(cachep, node); |
1307 | } |
1308 | init_node_lock_keys(node); |
1309 | |
1310 | return 0; |
1311 | bad: |
1312 | cpuup_canceled(cpu); |
1313 | return -ENOMEM; |
1314 | } |
1315 | |
1316 | static int __cpuinit cpuup_callback(struct notifier_block *nfb, |
1317 | unsigned long action, void *hcpu) |
1318 | { |
1319 | long cpu = (long)hcpu; |
1320 | int err = 0; |
1321 | |
1322 | switch (action) { |
1323 | case CPU_UP_PREPARE: |
1324 | case CPU_UP_PREPARE_FROZEN: |
1325 | mutex_lock(&cache_chain_mutex); |
1326 | err = cpuup_prepare(cpu); |
1327 | mutex_unlock(&cache_chain_mutex); |
1328 | break; |
1329 | case CPU_ONLINE: |
1330 | case CPU_ONLINE_FROZEN: |
1331 | start_cpu_timer(cpu); |
1332 | break; |
1333 | #ifdef CONFIG_HOTPLUG_CPU |
1334 | case CPU_DOWN_PREPARE: |
1335 | case CPU_DOWN_PREPARE_FROZEN: |
1336 | /* |
1337 | * Shutdown cache reaper. Note that the cache_chain_mutex is |
1338 | * held so that if cache_reap() is invoked it cannot do |
1339 | * anything expensive but will only modify reap_work |
1340 | * and reschedule the timer. |
1341 | */ |
1342 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); |
1343 | /* Now the cache_reaper is guaranteed to be not running. */ |
1344 | per_cpu(slab_reap_work, cpu).work.func = NULL; |
1345 | break; |
1346 | case CPU_DOWN_FAILED: |
1347 | case CPU_DOWN_FAILED_FROZEN: |
1348 | start_cpu_timer(cpu); |
1349 | break; |
1350 | case CPU_DEAD: |
1351 | case CPU_DEAD_FROZEN: |
1352 | /* |
1353 | * Even if all the cpus of a node are down, we don't free the |
1354 | * kmem_list3 of any cache. This to avoid a race between |
1355 | * cpu_down, and a kmalloc allocation from another cpu for |
1356 | * memory from the node of the cpu going down. The list3 |
1357 | * structure is usually allocated from kmem_cache_create() and |
1358 | * gets destroyed at kmem_cache_destroy(). |
1359 | */ |
1360 | /* fall through */ |
1361 | #endif |
1362 | case CPU_UP_CANCELED: |
1363 | case CPU_UP_CANCELED_FROZEN: |
1364 | mutex_lock(&cache_chain_mutex); |
1365 | cpuup_canceled(cpu); |
1366 | mutex_unlock(&cache_chain_mutex); |
1367 | break; |
1368 | } |
1369 | return notifier_from_errno(err); |
1370 | } |
1371 | |
1372 | static struct notifier_block __cpuinitdata cpucache_notifier = { |
1373 | &cpuup_callback, NULL, 0 |
1374 | }; |
1375 | |
1376 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
1377 | /* |
1378 | * Drains freelist for a node on each slab cache, used for memory hot-remove. |
1379 | * Returns -EBUSY if all objects cannot be drained so that the node is not |
1380 | * removed. |
1381 | * |
1382 | * Must hold cache_chain_mutex. |
1383 | */ |
1384 | static int __meminit drain_cache_nodelists_node(int node) |
1385 | { |
1386 | struct kmem_cache *cachep; |
1387 | int ret = 0; |
1388 | |
1389 | list_for_each_entry(cachep, &cache_chain, next) { |
1390 | struct kmem_list3 *l3; |
1391 | |
1392 | l3 = cachep->nodelists[node]; |
1393 | if (!l3) |
1394 | continue; |
1395 | |
1396 | drain_freelist(cachep, l3, l3->free_objects); |
1397 | |
1398 | if (!list_empty(&l3->slabs_full) || |
1399 | !list_empty(&l3->slabs_partial)) { |
1400 | ret = -EBUSY; |
1401 | break; |
1402 | } |
1403 | } |
1404 | return ret; |
1405 | } |
1406 | |
1407 | static int __meminit slab_memory_callback(struct notifier_block *self, |
1408 | unsigned long action, void *arg) |
1409 | { |
1410 | struct memory_notify *mnb = arg; |
1411 | int ret = 0; |
1412 | int nid; |
1413 | |
1414 | nid = mnb->status_change_nid; |
1415 | if (nid < 0) |
1416 | goto out; |
1417 | |
1418 | switch (action) { |
1419 | case MEM_GOING_ONLINE: |
1420 | mutex_lock(&cache_chain_mutex); |
1421 | ret = init_cache_nodelists_node(nid); |
1422 | mutex_unlock(&cache_chain_mutex); |
1423 | break; |
1424 | case MEM_GOING_OFFLINE: |
1425 | mutex_lock(&cache_chain_mutex); |
1426 | ret = drain_cache_nodelists_node(nid); |
1427 | mutex_unlock(&cache_chain_mutex); |
1428 | break; |
1429 | case MEM_ONLINE: |
1430 | case MEM_OFFLINE: |
1431 | case MEM_CANCEL_ONLINE: |
1432 | case MEM_CANCEL_OFFLINE: |
1433 | break; |
1434 | } |
1435 | out: |
1436 | return notifier_from_errno(ret); |
1437 | } |
1438 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ |
1439 | |
1440 | /* |
1441 | * swap the static kmem_list3 with kmalloced memory |
1442 | */ |
1443 | static void __init init_list(struct kmem_cache *cachep, struct kmem_list3 *list, |
1444 | int nodeid) |
1445 | { |
1446 | struct kmem_list3 *ptr; |
1447 | |
1448 | ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_NOWAIT, nodeid); |
1449 | BUG_ON(!ptr); |
1450 | |
1451 | memcpy(ptr, list, sizeof(struct kmem_list3)); |
1452 | /* |
1453 | * Do not assume that spinlocks can be initialized via memcpy: |
1454 | */ |
1455 | spin_lock_init(&ptr->list_lock); |
1456 | |
1457 | MAKE_ALL_LISTS(cachep, ptr, nodeid); |
1458 | cachep->nodelists[nodeid] = ptr; |
1459 | } |
1460 | |
1461 | /* |
1462 | * For setting up all the kmem_list3s for cache whose buffer_size is same as |
1463 | * size of kmem_list3. |
1464 | */ |
1465 | static void __init set_up_list3s(struct kmem_cache *cachep, int index) |
1466 | { |
1467 | int node; |
1468 | |
1469 | for_each_online_node(node) { |
1470 | cachep->nodelists[node] = &initkmem_list3[index + node]; |
1471 | cachep->nodelists[node]->next_reap = jiffies + |
1472 | REAPTIMEOUT_LIST3 + |
1473 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
1474 | } |
1475 | } |
1476 | |
1477 | /* |
1478 | * Initialisation. Called after the page allocator have been initialised and |
1479 | * before smp_init(). |
1480 | */ |
1481 | void __init kmem_cache_init(void) |
1482 | { |
1483 | size_t left_over; |
1484 | struct cache_sizes *sizes; |
1485 | struct cache_names *names; |
1486 | int i; |
1487 | int order; |
1488 | int node; |
1489 | |
1490 | if (num_possible_nodes() == 1) |
1491 | use_alien_caches = 0; |
1492 | |
1493 | for (i = 0; i < NUM_INIT_LISTS; i++) { |
1494 | kmem_list3_init(&initkmem_list3[i]); |
1495 | if (i < MAX_NUMNODES) |
1496 | cache_cache.nodelists[i] = NULL; |
1497 | } |
1498 | set_up_list3s(&cache_cache, CACHE_CACHE); |
1499 | |
1500 | /* |
1501 | * Fragmentation resistance on low memory - only use bigger |
1502 | * page orders on machines with more than 32MB of memory. |
1503 | */ |
1504 | if (totalram_pages > (32 << 20) >> PAGE_SHIFT) |
1505 | slab_break_gfp_order = BREAK_GFP_ORDER_HI; |
1506 | |
1507 | /* Bootstrap is tricky, because several objects are allocated |
1508 | * from caches that do not exist yet: |
1509 | * 1) initialize the cache_cache cache: it contains the struct |
1510 | * kmem_cache structures of all caches, except cache_cache itself: |
1511 | * cache_cache is statically allocated. |
1512 | * Initially an __init data area is used for the head array and the |
1513 | * kmem_list3 structures, it's replaced with a kmalloc allocated |
1514 | * array at the end of the bootstrap. |
1515 | * 2) Create the first kmalloc cache. |
1516 | * The struct kmem_cache for the new cache is allocated normally. |
1517 | * An __init data area is used for the head array. |
1518 | * 3) Create the remaining kmalloc caches, with minimally sized |
1519 | * head arrays. |
1520 | * 4) Replace the __init data head arrays for cache_cache and the first |
1521 | * kmalloc cache with kmalloc allocated arrays. |
1522 | * 5) Replace the __init data for kmem_list3 for cache_cache and |
1523 | * the other cache's with kmalloc allocated memory. |
1524 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. |
1525 | */ |
1526 | |
1527 | node = numa_mem_id(); |
1528 | |
1529 | /* 1) create the cache_cache */ |
1530 | INIT_LIST_HEAD(&cache_chain); |
1531 | list_add(&cache_cache.next, &cache_chain); |
1532 | cache_cache.colour_off = cache_line_size(); |
1533 | cache_cache.array[smp_processor_id()] = &initarray_cache.cache; |
1534 | cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE + node]; |
1535 | |
1536 | /* |
1537 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids |
1538 | */ |
1539 | cache_cache.buffer_size = offsetof(struct kmem_cache, array[nr_cpu_ids]) + |
1540 | nr_node_ids * sizeof(struct kmem_list3 *); |
1541 | #if DEBUG |
1542 | cache_cache.obj_size = cache_cache.buffer_size; |
1543 | #endif |
1544 | cache_cache.buffer_size = ALIGN(cache_cache.buffer_size, |
1545 | cache_line_size()); |
1546 | cache_cache.reciprocal_buffer_size = |
1547 | reciprocal_value(cache_cache.buffer_size); |
1548 | |
1549 | for (order = 0; order < MAX_ORDER; order++) { |
1550 | cache_estimate(order, cache_cache.buffer_size, |
1551 | cache_line_size(), 0, &left_over, &cache_cache.num); |
1552 | if (cache_cache.num) |
1553 | break; |
1554 | } |
1555 | BUG_ON(!cache_cache.num); |
1556 | cache_cache.gfporder = order; |
1557 | cache_cache.colour = left_over / cache_cache.colour_off; |
1558 | cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) + |
1559 | sizeof(struct slab), cache_line_size()); |
1560 | |
1561 | /* 2+3) create the kmalloc caches */ |
1562 | sizes = malloc_sizes; |
1563 | names = cache_names; |
1564 | |
1565 | /* |
1566 | * Initialize the caches that provide memory for the array cache and the |
1567 | * kmem_list3 structures first. Without this, further allocations will |
1568 | * bug. |
1569 | */ |
1570 | |
1571 | sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name, |
1572 | sizes[INDEX_AC].cs_size, |
1573 | ARCH_KMALLOC_MINALIGN, |
1574 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, |
1575 | NULL); |
1576 | |
1577 | if (INDEX_AC != INDEX_L3) { |
1578 | sizes[INDEX_L3].cs_cachep = |
1579 | kmem_cache_create(names[INDEX_L3].name, |
1580 | sizes[INDEX_L3].cs_size, |
1581 | ARCH_KMALLOC_MINALIGN, |
1582 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, |
1583 | NULL); |
1584 | } |
1585 | |
1586 | slab_early_init = 0; |
1587 | |
1588 | while (sizes->cs_size != ULONG_MAX) { |
1589 | /* |
1590 | * For performance, all the general caches are L1 aligned. |
1591 | * This should be particularly beneficial on SMP boxes, as it |
1592 | * eliminates "false sharing". |
1593 | * Note for systems short on memory removing the alignment will |
1594 | * allow tighter packing of the smaller caches. |
1595 | */ |
1596 | if (!sizes->cs_cachep) { |
1597 | sizes->cs_cachep = kmem_cache_create(names->name, |
1598 | sizes->cs_size, |
1599 | ARCH_KMALLOC_MINALIGN, |
1600 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, |
1601 | NULL); |
1602 | } |
1603 | #ifdef CONFIG_ZONE_DMA |
1604 | sizes->cs_dmacachep = kmem_cache_create( |
1605 | names->name_dma, |
1606 | sizes->cs_size, |
1607 | ARCH_KMALLOC_MINALIGN, |
1608 | ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA| |
1609 | SLAB_PANIC, |
1610 | NULL); |
1611 | #endif |
1612 | sizes++; |
1613 | names++; |
1614 | } |
1615 | /* 4) Replace the bootstrap head arrays */ |
1616 | { |
1617 | struct array_cache *ptr; |
1618 | |
1619 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1620 | |
1621 | BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); |
1622 | memcpy(ptr, cpu_cache_get(&cache_cache), |
1623 | sizeof(struct arraycache_init)); |
1624 | /* |
1625 | * Do not assume that spinlocks can be initialized via memcpy: |
1626 | */ |
1627 | spin_lock_init(&ptr->lock); |
1628 | |
1629 | cache_cache.array[smp_processor_id()] = ptr; |
1630 | |
1631 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); |
1632 | |
1633 | BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep) |
1634 | != &initarray_generic.cache); |
1635 | memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), |
1636 | sizeof(struct arraycache_init)); |
1637 | /* |
1638 | * Do not assume that spinlocks can be initialized via memcpy: |
1639 | */ |
1640 | spin_lock_init(&ptr->lock); |
1641 | |
1642 | malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = |
1643 | ptr; |
1644 | } |
1645 | /* 5) Replace the bootstrap kmem_list3's */ |
1646 | { |
1647 | int nid; |
1648 | |
1649 | for_each_online_node(nid) { |
1650 | init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid); |
1651 | |
1652 | init_list(malloc_sizes[INDEX_AC].cs_cachep, |
1653 | &initkmem_list3[SIZE_AC + nid], nid); |
1654 | |
1655 | if (INDEX_AC != INDEX_L3) { |
1656 | init_list(malloc_sizes[INDEX_L3].cs_cachep, |
1657 | &initkmem_list3[SIZE_L3 + nid], nid); |
1658 | } |
1659 | } |
1660 | } |
1661 | |
1662 | g_cpucache_up = EARLY; |
1663 | } |
1664 | |
1665 | void __init kmem_cache_init_late(void) |
1666 | { |
1667 | struct kmem_cache *cachep; |
1668 | |
1669 | /* Annotate slab for lockdep -- annotate the malloc caches */ |
1670 | init_lock_keys(); |
1671 | |
1672 | /* 6) resize the head arrays to their final sizes */ |
1673 | mutex_lock(&cache_chain_mutex); |
1674 | list_for_each_entry(cachep, &cache_chain, next) |
1675 | if (enable_cpucache(cachep, GFP_NOWAIT)) |
1676 | BUG(); |
1677 | mutex_unlock(&cache_chain_mutex); |
1678 | |
1679 | /* Done! */ |
1680 | g_cpucache_up = FULL; |
1681 | |
1682 | /* |
1683 | * Register a cpu startup notifier callback that initializes |
1684 | * cpu_cache_get for all new cpus |
1685 | */ |
1686 | register_cpu_notifier(&cpucache_notifier); |
1687 | |
1688 | #ifdef CONFIG_NUMA |
1689 | /* |
1690 | * Register a memory hotplug callback that initializes and frees |
1691 | * nodelists. |
1692 | */ |
1693 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
1694 | #endif |
1695 | |
1696 | /* |
1697 | * The reap timers are started later, with a module init call: That part |
1698 | * of the kernel is not yet operational. |
1699 | */ |
1700 | } |
1701 | |
1702 | static int __init cpucache_init(void) |
1703 | { |
1704 | int cpu; |
1705 | |
1706 | /* |
1707 | * Register the timers that return unneeded pages to the page allocator |
1708 | */ |
1709 | for_each_online_cpu(cpu) |
1710 | start_cpu_timer(cpu); |
1711 | return 0; |
1712 | } |
1713 | __initcall(cpucache_init); |
1714 | |
1715 | /* |
1716 | * Interface to system's page allocator. No need to hold the cache-lock. |
1717 | * |
1718 | * If we requested dmaable memory, we will get it. Even if we |
1719 | * did not request dmaable memory, we might get it, but that |
1720 | * would be relatively rare and ignorable. |
1721 | */ |
1722 | static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
1723 | { |
1724 | struct page *page; |
1725 | int nr_pages; |
1726 | int i; |
1727 | |
1728 | #ifndef CONFIG_MMU |
1729 | /* |
1730 | * Nommu uses slab's for process anonymous memory allocations, and thus |
1731 | * requires __GFP_COMP to properly refcount higher order allocations |
1732 | */ |
1733 | flags |= __GFP_COMP; |
1734 | #endif |
1735 | |
1736 | flags |= cachep->gfpflags; |
1737 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1738 | flags |= __GFP_RECLAIMABLE; |
1739 | |
1740 | page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); |
1741 | if (!page) |
1742 | return NULL; |
1743 | |
1744 | nr_pages = (1 << cachep->gfporder); |
1745 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1746 | add_zone_page_state(page_zone(page), |
1747 | NR_SLAB_RECLAIMABLE, nr_pages); |
1748 | else |
1749 | add_zone_page_state(page_zone(page), |
1750 | NR_SLAB_UNRECLAIMABLE, nr_pages); |
1751 | for (i = 0; i < nr_pages; i++) |
1752 | __SetPageSlab(page + i); |
1753 | |
1754 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { |
1755 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); |
1756 | |
1757 | if (cachep->ctor) |
1758 | kmemcheck_mark_uninitialized_pages(page, nr_pages); |
1759 | else |
1760 | kmemcheck_mark_unallocated_pages(page, nr_pages); |
1761 | } |
1762 | |
1763 | return page_address(page); |
1764 | } |
1765 | |
1766 | /* |
1767 | * Interface to system's page release. |
1768 | */ |
1769 | static void kmem_freepages(struct kmem_cache *cachep, void *addr) |
1770 | { |
1771 | unsigned long i = (1 << cachep->gfporder); |
1772 | struct page *page = virt_to_page(addr); |
1773 | const unsigned long nr_freed = i; |
1774 | |
1775 | kmemcheck_free_shadow(page, cachep->gfporder); |
1776 | |
1777 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1778 | sub_zone_page_state(page_zone(page), |
1779 | NR_SLAB_RECLAIMABLE, nr_freed); |
1780 | else |
1781 | sub_zone_page_state(page_zone(page), |
1782 | NR_SLAB_UNRECLAIMABLE, nr_freed); |
1783 | while (i--) { |
1784 | BUG_ON(!PageSlab(page)); |
1785 | __ClearPageSlab(page); |
1786 | page++; |
1787 | } |
1788 | if (current->reclaim_state) |
1789 | current->reclaim_state->reclaimed_slab += nr_freed; |
1790 | free_pages((unsigned long)addr, cachep->gfporder); |
1791 | } |
1792 | |
1793 | static void kmem_rcu_free(struct rcu_head *head) |
1794 | { |
1795 | struct slab_rcu *slab_rcu = (struct slab_rcu *)head; |
1796 | struct kmem_cache *cachep = slab_rcu->cachep; |
1797 | |
1798 | kmem_freepages(cachep, slab_rcu->addr); |
1799 | if (OFF_SLAB(cachep)) |
1800 | kmem_cache_free(cachep->slabp_cache, slab_rcu); |
1801 | } |
1802 | |
1803 | #if DEBUG |
1804 | |
1805 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1806 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, |
1807 | unsigned long caller) |
1808 | { |
1809 | int size = obj_size(cachep); |
1810 | |
1811 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; |
1812 | |
1813 | if (size < 5 * sizeof(unsigned long)) |
1814 | return; |
1815 | |
1816 | *addr++ = 0x12345678; |
1817 | *addr++ = caller; |
1818 | *addr++ = smp_processor_id(); |
1819 | size -= 3 * sizeof(unsigned long); |
1820 | { |
1821 | unsigned long *sptr = &caller; |
1822 | unsigned long svalue; |
1823 | |
1824 | while (!kstack_end(sptr)) { |
1825 | svalue = *sptr++; |
1826 | if (kernel_text_address(svalue)) { |
1827 | *addr++ = svalue; |
1828 | size -= sizeof(unsigned long); |
1829 | if (size <= sizeof(unsigned long)) |
1830 | break; |
1831 | } |
1832 | } |
1833 | |
1834 | } |
1835 | *addr++ = 0x87654321; |
1836 | } |
1837 | #endif |
1838 | |
1839 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) |
1840 | { |
1841 | int size = obj_size(cachep); |
1842 | addr = &((char *)addr)[obj_offset(cachep)]; |
1843 | |
1844 | memset(addr, val, size); |
1845 | *(unsigned char *)(addr + size - 1) = POISON_END; |
1846 | } |
1847 | |
1848 | static void dump_line(char *data, int offset, int limit) |
1849 | { |
1850 | int i; |
1851 | unsigned char error = 0; |
1852 | int bad_count = 0; |
1853 | |
1854 | printk(KERN_ERR "%03x:", offset); |
1855 | for (i = 0; i < limit; i++) { |
1856 | if (data[offset + i] != POISON_FREE) { |
1857 | error = data[offset + i]; |
1858 | bad_count++; |
1859 | } |
1860 | printk(" %02x", (unsigned char)data[offset + i]); |
1861 | } |
1862 | printk("\n"); |
1863 | |
1864 | if (bad_count == 1) { |
1865 | error ^= POISON_FREE; |
1866 | if (!(error & (error - 1))) { |
1867 | printk(KERN_ERR "Single bit error detected. Probably " |
1868 | "bad RAM.\n"); |
1869 | #ifdef CONFIG_X86 |
1870 | printk(KERN_ERR "Run memtest86+ or a similar memory " |
1871 | "test tool.\n"); |
1872 | #else |
1873 | printk(KERN_ERR "Run a memory test tool.\n"); |
1874 | #endif |
1875 | } |
1876 | } |
1877 | } |
1878 | #endif |
1879 | |
1880 | #if DEBUG |
1881 | |
1882 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) |
1883 | { |
1884 | int i, size; |
1885 | char *realobj; |
1886 | |
1887 | if (cachep->flags & SLAB_RED_ZONE) { |
1888 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", |
1889 | *dbg_redzone1(cachep, objp), |
1890 | *dbg_redzone2(cachep, objp)); |
1891 | } |
1892 | |
1893 | if (cachep->flags & SLAB_STORE_USER) { |
1894 | printk(KERN_ERR "Last user: [<%p>]", |
1895 | *dbg_userword(cachep, objp)); |
1896 | print_symbol("(%s)", |
1897 | (unsigned long)*dbg_userword(cachep, objp)); |
1898 | printk("\n"); |
1899 | } |
1900 | realobj = (char *)objp + obj_offset(cachep); |
1901 | size = obj_size(cachep); |
1902 | for (i = 0; i < size && lines; i += 16, lines--) { |
1903 | int limit; |
1904 | limit = 16; |
1905 | if (i + limit > size) |
1906 | limit = size - i; |
1907 | dump_line(realobj, i, limit); |
1908 | } |
1909 | } |
1910 | |
1911 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) |
1912 | { |
1913 | char *realobj; |
1914 | int size, i; |
1915 | int lines = 0; |
1916 | |
1917 | realobj = (char *)objp + obj_offset(cachep); |
1918 | size = obj_size(cachep); |
1919 | |
1920 | for (i = 0; i < size; i++) { |
1921 | char exp = POISON_FREE; |
1922 | if (i == size - 1) |
1923 | exp = POISON_END; |
1924 | if (realobj[i] != exp) { |
1925 | int limit; |
1926 | /* Mismatch ! */ |
1927 | /* Print header */ |
1928 | if (lines == 0) { |
1929 | printk(KERN_ERR |
1930 | "Slab corruption: %s start=%p, len=%d\n", |
1931 | cachep->name, realobj, size); |
1932 | print_objinfo(cachep, objp, 0); |
1933 | } |
1934 | /* Hexdump the affected line */ |
1935 | i = (i / 16) * 16; |
1936 | limit = 16; |
1937 | if (i + limit > size) |
1938 | limit = size - i; |
1939 | dump_line(realobj, i, limit); |
1940 | i += 16; |
1941 | lines++; |
1942 | /* Limit to 5 lines */ |
1943 | if (lines > 5) |
1944 | break; |
1945 | } |
1946 | } |
1947 | if (lines != 0) { |
1948 | /* Print some data about the neighboring objects, if they |
1949 | * exist: |
1950 | */ |
1951 | struct slab *slabp = virt_to_slab(objp); |
1952 | unsigned int objnr; |
1953 | |
1954 | objnr = obj_to_index(cachep, slabp, objp); |
1955 | if (objnr) { |
1956 | objp = index_to_obj(cachep, slabp, objnr - 1); |
1957 | realobj = (char *)objp + obj_offset(cachep); |
1958 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
1959 | realobj, size); |
1960 | print_objinfo(cachep, objp, 2); |
1961 | } |
1962 | if (objnr + 1 < cachep->num) { |
1963 | objp = index_to_obj(cachep, slabp, objnr + 1); |
1964 | realobj = (char *)objp + obj_offset(cachep); |
1965 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
1966 | realobj, size); |
1967 | print_objinfo(cachep, objp, 2); |
1968 | } |
1969 | } |
1970 | } |
1971 | #endif |
1972 | |
1973 | #if DEBUG |
1974 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) |
1975 | { |
1976 | int i; |
1977 | for (i = 0; i < cachep->num; i++) { |
1978 | void *objp = index_to_obj(cachep, slabp, i); |
1979 | |
1980 | if (cachep->flags & SLAB_POISON) { |
1981 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1982 | if (cachep->buffer_size % PAGE_SIZE == 0 && |
1983 | OFF_SLAB(cachep)) |
1984 | kernel_map_pages(virt_to_page(objp), |
1985 | cachep->buffer_size / PAGE_SIZE, 1); |
1986 | else |
1987 | check_poison_obj(cachep, objp); |
1988 | #else |
1989 | check_poison_obj(cachep, objp); |
1990 | #endif |
1991 | } |
1992 | if (cachep->flags & SLAB_RED_ZONE) { |
1993 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
1994 | slab_error(cachep, "start of a freed object " |
1995 | "was overwritten"); |
1996 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
1997 | slab_error(cachep, "end of a freed object " |
1998 | "was overwritten"); |
1999 | } |
2000 | } |
2001 | } |
2002 | #else |
2003 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) |
2004 | { |
2005 | } |
2006 | #endif |
2007 | |
2008 | /** |
2009 | * slab_destroy - destroy and release all objects in a slab |
2010 | * @cachep: cache pointer being destroyed |
2011 | * @slabp: slab pointer being destroyed |
2012 | * |
2013 | * Destroy all the objs in a slab, and release the mem back to the system. |
2014 | * Before calling the slab must have been unlinked from the cache. The |
2015 | * cache-lock is not held/needed. |
2016 | */ |
2017 | static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) |
2018 | { |
2019 | void *addr = slabp->s_mem - slabp->colouroff; |
2020 | |
2021 | slab_destroy_debugcheck(cachep, slabp); |
2022 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { |
2023 | struct slab_rcu *slab_rcu; |
2024 | |
2025 | slab_rcu = (struct slab_rcu *)slabp; |
2026 | slab_rcu->cachep = cachep; |
2027 | slab_rcu->addr = addr; |
2028 | call_rcu(&slab_rcu->head, kmem_rcu_free); |
2029 | } else { |
2030 | kmem_freepages(cachep, addr); |
2031 | if (OFF_SLAB(cachep)) |
2032 | kmem_cache_free(cachep->slabp_cache, slabp); |
2033 | } |
2034 | } |
2035 | |
2036 | static void __kmem_cache_destroy(struct kmem_cache *cachep) |
2037 | { |
2038 | int i; |
2039 | struct kmem_list3 *l3; |
2040 | |
2041 | for_each_online_cpu(i) |
2042 | kfree(cachep->array[i]); |
2043 | |
2044 | /* NUMA: free the list3 structures */ |
2045 | for_each_online_node(i) { |
2046 | l3 = cachep->nodelists[i]; |
2047 | if (l3) { |
2048 | kfree(l3->shared); |
2049 | free_alien_cache(l3->alien); |
2050 | kfree(l3); |
2051 | } |
2052 | } |
2053 | kmem_cache_free(&cache_cache, cachep); |
2054 | } |
2055 | |
2056 | |
2057 | /** |
2058 | * calculate_slab_order - calculate size (page order) of slabs |
2059 | * @cachep: pointer to the cache that is being created |
2060 | * @size: size of objects to be created in this cache. |
2061 | * @align: required alignment for the objects. |
2062 | * @flags: slab allocation flags |
2063 | * |
2064 | * Also calculates the number of objects per slab. |
2065 | * |
2066 | * This could be made much more intelligent. For now, try to avoid using |
2067 | * high order pages for slabs. When the gfp() functions are more friendly |
2068 | * towards high-order requests, this should be changed. |
2069 | */ |
2070 | static size_t calculate_slab_order(struct kmem_cache *cachep, |
2071 | size_t size, size_t align, unsigned long flags) |
2072 | { |
2073 | unsigned long offslab_limit; |
2074 | size_t left_over = 0; |
2075 | int gfporder; |
2076 | |
2077 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { |
2078 | unsigned int num; |
2079 | size_t remainder; |
2080 | |
2081 | cache_estimate(gfporder, size, align, flags, &remainder, &num); |
2082 | if (!num) |
2083 | continue; |
2084 | |
2085 | if (flags & CFLGS_OFF_SLAB) { |
2086 | /* |
2087 | * Max number of objs-per-slab for caches which |
2088 | * use off-slab slabs. Needed to avoid a possible |
2089 | * looping condition in cache_grow(). |
2090 | */ |
2091 | offslab_limit = size - sizeof(struct slab); |
2092 | offslab_limit /= sizeof(kmem_bufctl_t); |
2093 | |
2094 | if (num > offslab_limit) |
2095 | break; |
2096 | } |
2097 | |
2098 | /* Found something acceptable - save it away */ |
2099 | cachep->num = num; |
2100 | cachep->gfporder = gfporder; |
2101 | left_over = remainder; |
2102 | |
2103 | /* |
2104 | * A VFS-reclaimable slab tends to have most allocations |
2105 | * as GFP_NOFS and we really don't want to have to be allocating |
2106 | * higher-order pages when we are unable to shrink dcache. |
2107 | */ |
2108 | if (flags & SLAB_RECLAIM_ACCOUNT) |
2109 | break; |
2110 | |
2111 | /* |
2112 | * Large number of objects is good, but very large slabs are |
2113 | * currently bad for the gfp()s. |
2114 | */ |
2115 | if (gfporder >= slab_break_gfp_order) |
2116 | break; |
2117 | |
2118 | /* |
2119 | * Acceptable internal fragmentation? |
2120 | */ |
2121 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) |
2122 | break; |
2123 | } |
2124 | return left_over; |
2125 | } |
2126 | |
2127 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) |
2128 | { |
2129 | if (g_cpucache_up == FULL) |
2130 | return enable_cpucache(cachep, gfp); |
2131 | |
2132 | if (g_cpucache_up == NONE) { |
2133 | /* |
2134 | * Note: the first kmem_cache_create must create the cache |
2135 | * that's used by kmalloc(24), otherwise the creation of |
2136 | * further caches will BUG(). |
2137 | */ |
2138 | cachep->array[smp_processor_id()] = &initarray_generic.cache; |
2139 | |
2140 | /* |
2141 | * If the cache that's used by kmalloc(sizeof(kmem_list3)) is |
2142 | * the first cache, then we need to set up all its list3s, |
2143 | * otherwise the creation of further caches will BUG(). |
2144 | */ |
2145 | set_up_list3s(cachep, SIZE_AC); |
2146 | if (INDEX_AC == INDEX_L3) |
2147 | g_cpucache_up = PARTIAL_L3; |
2148 | else |
2149 | g_cpucache_up = PARTIAL_AC; |
2150 | } else { |
2151 | cachep->array[smp_processor_id()] = |
2152 | kmalloc(sizeof(struct arraycache_init), gfp); |
2153 | |
2154 | if (g_cpucache_up == PARTIAL_AC) { |
2155 | set_up_list3s(cachep, SIZE_L3); |
2156 | g_cpucache_up = PARTIAL_L3; |
2157 | } else { |
2158 | int node; |
2159 | for_each_online_node(node) { |
2160 | cachep->nodelists[node] = |
2161 | kmalloc_node(sizeof(struct kmem_list3), |
2162 | gfp, node); |
2163 | BUG_ON(!cachep->nodelists[node]); |
2164 | kmem_list3_init(cachep->nodelists[node]); |
2165 | } |
2166 | } |
2167 | } |
2168 | cachep->nodelists[numa_mem_id()]->next_reap = |
2169 | jiffies + REAPTIMEOUT_LIST3 + |
2170 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
2171 | |
2172 | cpu_cache_get(cachep)->avail = 0; |
2173 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
2174 | cpu_cache_get(cachep)->batchcount = 1; |
2175 | cpu_cache_get(cachep)->touched = 0; |
2176 | cachep->batchcount = 1; |
2177 | cachep->limit = BOOT_CPUCACHE_ENTRIES; |
2178 | return 0; |
2179 | } |
2180 | |
2181 | /** |
2182 | * kmem_cache_create - Create a cache. |
2183 | * @name: A string which is used in /proc/slabinfo to identify this cache. |
2184 | * @size: The size of objects to be created in this cache. |
2185 | * @align: The required alignment for the objects. |
2186 | * @flags: SLAB flags |
2187 | * @ctor: A constructor for the objects. |
2188 | * |
2189 | * Returns a ptr to the cache on success, NULL on failure. |
2190 | * Cannot be called within a int, but can be interrupted. |
2191 | * The @ctor is run when new pages are allocated by the cache. |
2192 | * |
2193 | * @name must be valid until the cache is destroyed. This implies that |
2194 | * the module calling this has to destroy the cache before getting unloaded. |
2195 | * |
2196 | * The flags are |
2197 | * |
2198 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
2199 | * to catch references to uninitialised memory. |
2200 | * |
2201 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
2202 | * for buffer overruns. |
2203 | * |
2204 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
2205 | * cacheline. This can be beneficial if you're counting cycles as closely |
2206 | * as davem. |
2207 | */ |
2208 | struct kmem_cache * |
2209 | kmem_cache_create (const char *name, size_t size, size_t align, |
2210 | unsigned long flags, void (*ctor)(void *)) |
2211 | { |
2212 | size_t left_over, slab_size, ralign; |
2213 | struct kmem_cache *cachep = NULL, *pc; |
2214 | gfp_t gfp; |
2215 | |
2216 | /* |
2217 | * Sanity checks... these are all serious usage bugs. |
2218 | */ |
2219 | if (!name || in_interrupt() || (size < BYTES_PER_WORD) || |
2220 | size > KMALLOC_MAX_SIZE) { |
2221 | printk(KERN_ERR "%s: Early error in slab %s\n", __func__, |
2222 | name); |
2223 | BUG(); |
2224 | } |
2225 | |
2226 | /* |
2227 | * We use cache_chain_mutex to ensure a consistent view of |
2228 | * cpu_online_mask as well. Please see cpuup_callback |
2229 | */ |
2230 | if (slab_is_available()) { |
2231 | get_online_cpus(); |
2232 | mutex_lock(&cache_chain_mutex); |
2233 | } |
2234 | |
2235 | list_for_each_entry(pc, &cache_chain, next) { |
2236 | char tmp; |
2237 | int res; |
2238 | |
2239 | /* |
2240 | * This happens when the module gets unloaded and doesn't |
2241 | * destroy its slab cache and no-one else reuses the vmalloc |
2242 | * area of the module. Print a warning. |
2243 | */ |
2244 | res = probe_kernel_address(pc->name, tmp); |
2245 | if (res) { |
2246 | printk(KERN_ERR |
2247 | "SLAB: cache with size %d has lost its name\n", |
2248 | pc->buffer_size); |
2249 | continue; |
2250 | } |
2251 | |
2252 | if (!strcmp(pc->name, name)) { |
2253 | printk(KERN_ERR |
2254 | "kmem_cache_create: duplicate cache %s\n", name); |
2255 | dump_stack(); |
2256 | goto oops; |
2257 | } |
2258 | } |
2259 | |
2260 | #if DEBUG |
2261 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ |
2262 | #if FORCED_DEBUG |
2263 | /* |
2264 | * Enable redzoning and last user accounting, except for caches with |
2265 | * large objects, if the increased size would increase the object size |
2266 | * above the next power of two: caches with object sizes just above a |
2267 | * power of two have a significant amount of internal fragmentation. |
2268 | */ |
2269 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + |
2270 | 2 * sizeof(unsigned long long))) |
2271 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; |
2272 | if (!(flags & SLAB_DESTROY_BY_RCU)) |
2273 | flags |= SLAB_POISON; |
2274 | #endif |
2275 | if (flags & SLAB_DESTROY_BY_RCU) |
2276 | BUG_ON(flags & SLAB_POISON); |
2277 | #endif |
2278 | /* |
2279 | * Always checks flags, a caller might be expecting debug support which |
2280 | * isn't available. |
2281 | */ |
2282 | BUG_ON(flags & ~CREATE_MASK); |
2283 | |
2284 | /* |
2285 | * Check that size is in terms of words. This is needed to avoid |
2286 | * unaligned accesses for some archs when redzoning is used, and makes |
2287 | * sure any on-slab bufctl's are also correctly aligned. |
2288 | */ |
2289 | if (size & (BYTES_PER_WORD - 1)) { |
2290 | size += (BYTES_PER_WORD - 1); |
2291 | size &= ~(BYTES_PER_WORD - 1); |
2292 | } |
2293 | |
2294 | /* calculate the final buffer alignment: */ |
2295 | |
2296 | /* 1) arch recommendation: can be overridden for debug */ |
2297 | if (flags & SLAB_HWCACHE_ALIGN) { |
2298 | /* |
2299 | * Default alignment: as specified by the arch code. Except if |
2300 | * an object is really small, then squeeze multiple objects into |
2301 | * one cacheline. |
2302 | */ |
2303 | ralign = cache_line_size(); |
2304 | while (size <= ralign / 2) |
2305 | ralign /= 2; |
2306 | } else { |
2307 | ralign = BYTES_PER_WORD; |
2308 | } |
2309 | |
2310 | /* |
2311 | * Redzoning and user store require word alignment or possibly larger. |
2312 | * Note this will be overridden by architecture or caller mandated |
2313 | * alignment if either is greater than BYTES_PER_WORD. |
2314 | */ |
2315 | if (flags & SLAB_STORE_USER) |
2316 | ralign = BYTES_PER_WORD; |
2317 | |
2318 | if (flags & SLAB_RED_ZONE) { |
2319 | ralign = REDZONE_ALIGN; |
2320 | /* If redzoning, ensure that the second redzone is suitably |
2321 | * aligned, by adjusting the object size accordingly. */ |
2322 | size += REDZONE_ALIGN - 1; |
2323 | size &= ~(REDZONE_ALIGN - 1); |
2324 | } |
2325 | |
2326 | /* 2) arch mandated alignment */ |
2327 | if (ralign < ARCH_SLAB_MINALIGN) { |
2328 | ralign = ARCH_SLAB_MINALIGN; |
2329 | } |
2330 | /* 3) caller mandated alignment */ |
2331 | if (ralign < align) { |
2332 | ralign = align; |
2333 | } |
2334 | /* disable debug if necessary */ |
2335 | if (ralign > __alignof__(unsigned long long)) |
2336 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2337 | /* |
2338 | * 4) Store it. |
2339 | */ |
2340 | align = ralign; |
2341 | |
2342 | if (slab_is_available()) |
2343 | gfp = GFP_KERNEL; |
2344 | else |
2345 | gfp = GFP_NOWAIT; |
2346 | |
2347 | /* Get cache's description obj. */ |
2348 | cachep = kmem_cache_zalloc(&cache_cache, gfp); |
2349 | if (!cachep) |
2350 | goto oops; |
2351 | |
2352 | cachep->nodelists = (struct kmem_list3 **)&cachep->array[nr_cpu_ids]; |
2353 | #if DEBUG |
2354 | cachep->obj_size = size; |
2355 | |
2356 | /* |
2357 | * Both debugging options require word-alignment which is calculated |
2358 | * into align above. |
2359 | */ |
2360 | if (flags & SLAB_RED_ZONE) { |
2361 | /* add space for red zone words */ |
2362 | cachep->obj_offset += sizeof(unsigned long long); |
2363 | size += 2 * sizeof(unsigned long long); |
2364 | } |
2365 | if (flags & SLAB_STORE_USER) { |
2366 | /* user store requires one word storage behind the end of |
2367 | * the real object. But if the second red zone needs to be |
2368 | * aligned to 64 bits, we must allow that much space. |
2369 | */ |
2370 | if (flags & SLAB_RED_ZONE) |
2371 | size += REDZONE_ALIGN; |
2372 | else |
2373 | size += BYTES_PER_WORD; |
2374 | } |
2375 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
2376 | if (size >= malloc_sizes[INDEX_L3 + 1].cs_size |
2377 | && cachep->obj_size > cache_line_size() && ALIGN(size, align) < PAGE_SIZE) { |
2378 | cachep->obj_offset += PAGE_SIZE - ALIGN(size, align); |
2379 | size = PAGE_SIZE; |
2380 | } |
2381 | #endif |
2382 | #endif |
2383 | |
2384 | /* |
2385 | * Determine if the slab management is 'on' or 'off' slab. |
2386 | * (bootstrapping cannot cope with offslab caches so don't do |
2387 | * it too early on. Always use on-slab management when |
2388 | * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) |
2389 | */ |
2390 | if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && |
2391 | !(flags & SLAB_NOLEAKTRACE)) |
2392 | /* |
2393 | * Size is large, assume best to place the slab management obj |
2394 | * off-slab (should allow better packing of objs). |
2395 | */ |
2396 | flags |= CFLGS_OFF_SLAB; |
2397 | |
2398 | size = ALIGN(size, align); |
2399 | |
2400 | left_over = calculate_slab_order(cachep, size, align, flags); |
2401 | |
2402 | if (!cachep->num) { |
2403 | printk(KERN_ERR |
2404 | "kmem_cache_create: couldn't create cache %s.\n", name); |
2405 | kmem_cache_free(&cache_cache, cachep); |
2406 | cachep = NULL; |
2407 | goto oops; |
2408 | } |
2409 | slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) |
2410 | + sizeof(struct slab), align); |
2411 | |
2412 | /* |
2413 | * If the slab has been placed off-slab, and we have enough space then |
2414 | * move it on-slab. This is at the expense of any extra colouring. |
2415 | */ |
2416 | if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { |
2417 | flags &= ~CFLGS_OFF_SLAB; |
2418 | left_over -= slab_size; |
2419 | } |
2420 | |
2421 | if (flags & CFLGS_OFF_SLAB) { |
2422 | /* really off slab. No need for manual alignment */ |
2423 | slab_size = |
2424 | cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); |
2425 | |
2426 | #ifdef CONFIG_PAGE_POISONING |
2427 | /* If we're going to use the generic kernel_map_pages() |
2428 | * poisoning, then it's going to smash the contents of |
2429 | * the redzone and userword anyhow, so switch them off. |
2430 | */ |
2431 | if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) |
2432 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2433 | #endif |
2434 | } |
2435 | |
2436 | cachep->colour_off = cache_line_size(); |
2437 | /* Offset must be a multiple of the alignment. */ |
2438 | if (cachep->colour_off < align) |
2439 | cachep->colour_off = align; |
2440 | cachep->colour = left_over / cachep->colour_off; |
2441 | cachep->slab_size = slab_size; |
2442 | cachep->flags = flags; |
2443 | cachep->gfpflags = 0; |
2444 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) |
2445 | cachep->gfpflags |= GFP_DMA; |
2446 | cachep->buffer_size = size; |
2447 | cachep->reciprocal_buffer_size = reciprocal_value(size); |
2448 | |
2449 | if (flags & CFLGS_OFF_SLAB) { |
2450 | cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); |
2451 | /* |
2452 | * This is a possibility for one of the malloc_sizes caches. |
2453 | * But since we go off slab only for object size greater than |
2454 | * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, |
2455 | * this should not happen at all. |
2456 | * But leave a BUG_ON for some lucky dude. |
2457 | */ |
2458 | BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); |
2459 | } |
2460 | cachep->ctor = ctor; |
2461 | cachep->name = name; |
2462 | |
2463 | if (setup_cpu_cache(cachep, gfp)) { |
2464 | __kmem_cache_destroy(cachep); |
2465 | cachep = NULL; |
2466 | goto oops; |
2467 | } |
2468 | |
2469 | if (flags & SLAB_DEBUG_OBJECTS) { |
2470 | /* |
2471 | * Would deadlock through slab_destroy()->call_rcu()-> |
2472 | * debug_object_activate()->kmem_cache_alloc(). |
2473 | */ |
2474 | WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU); |
2475 | |
2476 | slab_set_debugobj_lock_classes(cachep); |
2477 | } |
2478 | |
2479 | /* cache setup completed, link it into the list */ |
2480 | list_add(&cachep->next, &cache_chain); |
2481 | oops: |
2482 | if (!cachep && (flags & SLAB_PANIC)) |
2483 | panic("kmem_cache_create(): failed to create slab `%s'\n", |
2484 | name); |
2485 | if (slab_is_available()) { |
2486 | mutex_unlock(&cache_chain_mutex); |
2487 | put_online_cpus(); |
2488 | } |
2489 | return cachep; |
2490 | } |
2491 | EXPORT_SYMBOL(kmem_cache_create); |
2492 | |
2493 | #if DEBUG |
2494 | static void check_irq_off(void) |
2495 | { |
2496 | BUG_ON(!irqs_disabled()); |
2497 | } |
2498 | |
2499 | static void check_irq_on(void) |
2500 | { |
2501 | BUG_ON(irqs_disabled()); |
2502 | } |
2503 | |
2504 | static void check_spinlock_acquired(struct kmem_cache *cachep) |
2505 | { |
2506 | #ifdef CONFIG_SMP |
2507 | check_irq_off(); |
2508 | assert_spin_locked(&cachep->nodelists[numa_mem_id()]->list_lock); |
2509 | #endif |
2510 | } |
2511 | |
2512 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) |
2513 | { |
2514 | #ifdef CONFIG_SMP |
2515 | check_irq_off(); |
2516 | assert_spin_locked(&cachep->nodelists[node]->list_lock); |
2517 | #endif |
2518 | } |
2519 | |
2520 | #else |
2521 | #define check_irq_off() do { } while(0) |
2522 | #define check_irq_on() do { } while(0) |
2523 | #define check_spinlock_acquired(x) do { } while(0) |
2524 | #define check_spinlock_acquired_node(x, y) do { } while(0) |
2525 | #endif |
2526 | |
2527 | static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, |
2528 | struct array_cache *ac, |
2529 | int force, int node); |
2530 | |
2531 | static void do_drain(void *arg) |
2532 | { |
2533 | struct kmem_cache *cachep = arg; |
2534 | struct array_cache *ac; |
2535 | int node = numa_mem_id(); |
2536 | |
2537 | check_irq_off(); |
2538 | ac = cpu_cache_get(cachep); |
2539 | spin_lock(&cachep->nodelists[node]->list_lock); |
2540 | free_block(cachep, ac->entry, ac->avail, node); |
2541 | spin_unlock(&cachep->nodelists[node]->list_lock); |
2542 | ac->avail = 0; |
2543 | } |
2544 | |
2545 | static void drain_cpu_caches(struct kmem_cache *cachep) |
2546 | { |
2547 | struct kmem_list3 *l3; |
2548 | int node; |
2549 | |
2550 | on_each_cpu(do_drain, cachep, 1); |
2551 | check_irq_on(); |
2552 | for_each_online_node(node) { |
2553 | l3 = cachep->nodelists[node]; |
2554 | if (l3 && l3->alien) |
2555 | drain_alien_cache(cachep, l3->alien); |
2556 | } |
2557 | |
2558 | for_each_online_node(node) { |
2559 | l3 = cachep->nodelists[node]; |
2560 | if (l3) |
2561 | drain_array(cachep, l3, l3->shared, 1, node); |
2562 | } |
2563 | } |
2564 | |
2565 | /* |
2566 | * Remove slabs from the list of free slabs. |
2567 | * Specify the number of slabs to drain in tofree. |
2568 | * |
2569 | * Returns the actual number of slabs released. |
2570 | */ |
2571 | static int drain_freelist(struct kmem_cache *cache, |
2572 | struct kmem_list3 *l3, int tofree) |
2573 | { |
2574 | struct list_head *p; |
2575 | int nr_freed; |
2576 | struct slab *slabp; |
2577 | |
2578 | nr_freed = 0; |
2579 | while (nr_freed < tofree && !list_empty(&l3->slabs_free)) { |
2580 | |
2581 | spin_lock_irq(&l3->list_lock); |
2582 | p = l3->slabs_free.prev; |
2583 | if (p == &l3->slabs_free) { |
2584 | spin_unlock_irq(&l3->list_lock); |
2585 | goto out; |
2586 | } |
2587 | |
2588 | slabp = list_entry(p, struct slab, list); |
2589 | #if DEBUG |
2590 | BUG_ON(slabp->inuse); |
2591 | #endif |
2592 | list_del(&slabp->list); |
2593 | /* |
2594 | * Safe to drop the lock. The slab is no longer linked |
2595 | * to the cache. |
2596 | */ |
2597 | l3->free_objects -= cache->num; |
2598 | spin_unlock_irq(&l3->list_lock); |
2599 | slab_destroy(cache, slabp); |
2600 | nr_freed++; |
2601 | } |
2602 | out: |
2603 | return nr_freed; |
2604 | } |
2605 | |
2606 | /* Called with cache_chain_mutex held to protect against cpu hotplug */ |
2607 | static int __cache_shrink(struct kmem_cache *cachep) |
2608 | { |
2609 | int ret = 0, i = 0; |
2610 | struct kmem_list3 *l3; |
2611 | |
2612 | drain_cpu_caches(cachep); |
2613 | |
2614 | check_irq_on(); |
2615 | for_each_online_node(i) { |
2616 | l3 = cachep->nodelists[i]; |
2617 | if (!l3) |
2618 | continue; |
2619 | |
2620 | drain_freelist(cachep, l3, l3->free_objects); |
2621 | |
2622 | ret += !list_empty(&l3->slabs_full) || |
2623 | !list_empty(&l3->slabs_partial); |
2624 | } |
2625 | return (ret ? 1 : 0); |
2626 | } |
2627 | |
2628 | /** |
2629 | * kmem_cache_shrink - Shrink a cache. |
2630 | * @cachep: The cache to shrink. |
2631 | * |
2632 | * Releases as many slabs as possible for a cache. |
2633 | * To help debugging, a zero exit status indicates all slabs were released. |
2634 | */ |
2635 | int kmem_cache_shrink(struct kmem_cache *cachep) |
2636 | { |
2637 | int ret; |
2638 | BUG_ON(!cachep || in_interrupt()); |
2639 | |
2640 | get_online_cpus(); |
2641 | mutex_lock(&cache_chain_mutex); |
2642 | ret = __cache_shrink(cachep); |
2643 | mutex_unlock(&cache_chain_mutex); |
2644 | put_online_cpus(); |
2645 | return ret; |
2646 | } |
2647 | EXPORT_SYMBOL(kmem_cache_shrink); |
2648 | |
2649 | /** |
2650 | * kmem_cache_destroy - delete a cache |
2651 | * @cachep: the cache to destroy |
2652 | * |
2653 | * Remove a &struct kmem_cache object from the slab cache. |
2654 | * |
2655 | * It is expected this function will be called by a module when it is |
2656 | * unloaded. This will remove the cache completely, and avoid a duplicate |
2657 | * cache being allocated each time a module is loaded and unloaded, if the |
2658 | * module doesn't have persistent in-kernel storage across loads and unloads. |
2659 | * |
2660 | * The cache must be empty before calling this function. |
2661 | * |
2662 | * The caller must guarantee that no one will allocate memory from the cache |
2663 | * during the kmem_cache_destroy(). |
2664 | */ |
2665 | void kmem_cache_destroy(struct kmem_cache *cachep) |
2666 | { |
2667 | BUG_ON(!cachep || in_interrupt()); |
2668 | |
2669 | /* Find the cache in the chain of caches. */ |
2670 | get_online_cpus(); |
2671 | mutex_lock(&cache_chain_mutex); |
2672 | /* |
2673 | * the chain is never empty, cache_cache is never destroyed |
2674 | */ |
2675 | list_del(&cachep->next); |
2676 | if (__cache_shrink(cachep)) { |
2677 | slab_error(cachep, "Can't free all objects"); |
2678 | list_add(&cachep->next, &cache_chain); |
2679 | mutex_unlock(&cache_chain_mutex); |
2680 | put_online_cpus(); |
2681 | return; |
2682 | } |
2683 | |
2684 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) |
2685 | rcu_barrier(); |
2686 | |
2687 | __kmem_cache_destroy(cachep); |
2688 | mutex_unlock(&cache_chain_mutex); |
2689 | put_online_cpus(); |
2690 | } |
2691 | EXPORT_SYMBOL(kmem_cache_destroy); |
2692 | |
2693 | /* |
2694 | * Get the memory for a slab management obj. |
2695 | * For a slab cache when the slab descriptor is off-slab, slab descriptors |
2696 | * always come from malloc_sizes caches. The slab descriptor cannot |
2697 | * come from the same cache which is getting created because, |
2698 | * when we are searching for an appropriate cache for these |
2699 | * descriptors in kmem_cache_create, we search through the malloc_sizes array. |
2700 | * If we are creating a malloc_sizes cache here it would not be visible to |
2701 | * kmem_find_general_cachep till the initialization is complete. |
2702 | * Hence we cannot have slabp_cache same as the original cache. |
2703 | */ |
2704 | static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, |
2705 | int colour_off, gfp_t local_flags, |
2706 | int nodeid) |
2707 | { |
2708 | struct slab *slabp; |
2709 | |
2710 | if (OFF_SLAB(cachep)) { |
2711 | /* Slab management obj is off-slab. */ |
2712 | slabp = kmem_cache_alloc_node(cachep->slabp_cache, |
2713 | local_flags, nodeid); |
2714 | /* |
2715 | * If the first object in the slab is leaked (it's allocated |
2716 | * but no one has a reference to it), we want to make sure |
2717 | * kmemleak does not treat the ->s_mem pointer as a reference |
2718 | * to the object. Otherwise we will not report the leak. |
2719 | */ |
2720 | kmemleak_scan_area(&slabp->list, sizeof(struct list_head), |
2721 | local_flags); |
2722 | if (!slabp) |
2723 | return NULL; |
2724 | } else { |
2725 | slabp = objp + colour_off; |
2726 | colour_off += cachep->slab_size; |
2727 | } |
2728 | slabp->inuse = 0; |
2729 | slabp->colouroff = colour_off; |
2730 | slabp->s_mem = objp + colour_off; |
2731 | slabp->nodeid = nodeid; |
2732 | slabp->free = 0; |
2733 | return slabp; |
2734 | } |
2735 | |
2736 | static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) |
2737 | { |
2738 | return (kmem_bufctl_t *) (slabp + 1); |
2739 | } |
2740 | |
2741 | static void cache_init_objs(struct kmem_cache *cachep, |
2742 | struct slab *slabp) |
2743 | { |
2744 | int i; |
2745 | |
2746 | for (i = 0; i < cachep->num; i++) { |
2747 | void *objp = index_to_obj(cachep, slabp, i); |
2748 | #if DEBUG |
2749 | /* need to poison the objs? */ |
2750 | if (cachep->flags & SLAB_POISON) |
2751 | poison_obj(cachep, objp, POISON_FREE); |
2752 | if (cachep->flags & SLAB_STORE_USER) |
2753 | *dbg_userword(cachep, objp) = NULL; |
2754 | |
2755 | if (cachep->flags & SLAB_RED_ZONE) { |
2756 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2757 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2758 | } |
2759 | /* |
2760 | * Constructors are not allowed to allocate memory from the same |
2761 | * cache which they are a constructor for. Otherwise, deadlock. |
2762 | * They must also be threaded. |
2763 | */ |
2764 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) |
2765 | cachep->ctor(objp + obj_offset(cachep)); |
2766 | |
2767 | if (cachep->flags & SLAB_RED_ZONE) { |
2768 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2769 | slab_error(cachep, "constructor overwrote the" |
2770 | " end of an object"); |
2771 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2772 | slab_error(cachep, "constructor overwrote the" |
2773 | " start of an object"); |
2774 | } |
2775 | if ((cachep->buffer_size % PAGE_SIZE) == 0 && |
2776 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
2777 | kernel_map_pages(virt_to_page(objp), |
2778 | cachep->buffer_size / PAGE_SIZE, 0); |
2779 | #else |
2780 | if (cachep->ctor) |
2781 | cachep->ctor(objp); |
2782 | #endif |
2783 | slab_bufctl(slabp)[i] = i + 1; |
2784 | } |
2785 | slab_bufctl(slabp)[i - 1] = BUFCTL_END; |
2786 | } |
2787 | |
2788 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) |
2789 | { |
2790 | if (CONFIG_ZONE_DMA_FLAG) { |
2791 | if (flags & GFP_DMA) |
2792 | BUG_ON(!(cachep->gfpflags & GFP_DMA)); |
2793 | else |
2794 | BUG_ON(cachep->gfpflags & GFP_DMA); |
2795 | } |
2796 | } |
2797 | |
2798 | static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, |
2799 | int nodeid) |
2800 | { |
2801 | void *objp = index_to_obj(cachep, slabp, slabp->free); |
2802 | kmem_bufctl_t next; |
2803 | |
2804 | slabp->inuse++; |
2805 | next = slab_bufctl(slabp)[slabp->free]; |
2806 | #if DEBUG |
2807 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; |
2808 | WARN_ON(slabp->nodeid != nodeid); |
2809 | #endif |
2810 | slabp->free = next; |
2811 | |
2812 | return objp; |
2813 | } |
2814 | |
2815 | static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, |
2816 | void *objp, int nodeid) |
2817 | { |
2818 | unsigned int objnr = obj_to_index(cachep, slabp, objp); |
2819 | |
2820 | #if DEBUG |
2821 | /* Verify that the slab belongs to the intended node */ |
2822 | WARN_ON(slabp->nodeid != nodeid); |
2823 | |
2824 | if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { |
2825 | printk(KERN_ERR "slab: double free detected in cache " |
2826 | "'%s', objp %p\n", cachep->name, objp); |
2827 | BUG(); |
2828 | } |
2829 | #endif |
2830 | slab_bufctl(slabp)[objnr] = slabp->free; |
2831 | slabp->free = objnr; |
2832 | slabp->inuse--; |
2833 | } |
2834 | |
2835 | /* |
2836 | * Map pages beginning at addr to the given cache and slab. This is required |
2837 | * for the slab allocator to be able to lookup the cache and slab of a |
2838 | * virtual address for kfree, ksize, and slab debugging. |
2839 | */ |
2840 | static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, |
2841 | void *addr) |
2842 | { |
2843 | int nr_pages; |
2844 | struct page *page; |
2845 | |
2846 | page = virt_to_page(addr); |
2847 | |
2848 | nr_pages = 1; |
2849 | if (likely(!PageCompound(page))) |
2850 | nr_pages <<= cache->gfporder; |
2851 | |
2852 | do { |
2853 | page_set_cache(page, cache); |
2854 | page_set_slab(page, slab); |
2855 | page++; |
2856 | } while (--nr_pages); |
2857 | } |
2858 | |
2859 | /* |
2860 | * Grow (by 1) the number of slabs within a cache. This is called by |
2861 | * kmem_cache_alloc() when there are no active objs left in a cache. |
2862 | */ |
2863 | static int cache_grow(struct kmem_cache *cachep, |
2864 | gfp_t flags, int nodeid, void *objp) |
2865 | { |
2866 | struct slab *slabp; |
2867 | size_t offset; |
2868 | gfp_t local_flags; |
2869 | struct kmem_list3 *l3; |
2870 | |
2871 | /* |
2872 | * Be lazy and only check for valid flags here, keeping it out of the |
2873 | * critical path in kmem_cache_alloc(). |
2874 | */ |
2875 | BUG_ON(flags & GFP_SLAB_BUG_MASK); |
2876 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
2877 | |
2878 | /* Take the l3 list lock to change the colour_next on this node */ |
2879 | check_irq_off(); |
2880 | l3 = cachep->nodelists[nodeid]; |
2881 | spin_lock(&l3->list_lock); |
2882 | |
2883 | /* Get colour for the slab, and cal the next value. */ |
2884 | offset = l3->colour_next; |
2885 | l3->colour_next++; |
2886 | if (l3->colour_next >= cachep->colour) |
2887 | l3->colour_next = 0; |
2888 | spin_unlock(&l3->list_lock); |
2889 | |
2890 | offset *= cachep->colour_off; |
2891 | |
2892 | if (local_flags & __GFP_WAIT) |
2893 | local_irq_enable(); |
2894 | |
2895 | /* |
2896 | * The test for missing atomic flag is performed here, rather than |
2897 | * the more obvious place, simply to reduce the critical path length |
2898 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they |
2899 | * will eventually be caught here (where it matters). |
2900 | */ |
2901 | kmem_flagcheck(cachep, flags); |
2902 | |
2903 | /* |
2904 | * Get mem for the objs. Attempt to allocate a physical page from |
2905 | * 'nodeid'. |
2906 | */ |
2907 | if (!objp) |
2908 | objp = kmem_getpages(cachep, local_flags, nodeid); |
2909 | if (!objp) |
2910 | goto failed; |
2911 | |
2912 | /* Get slab management. */ |
2913 | slabp = alloc_slabmgmt(cachep, objp, offset, |
2914 | local_flags & ~GFP_CONSTRAINT_MASK, nodeid); |
2915 | if (!slabp) |
2916 | goto opps1; |
2917 | |
2918 | slab_map_pages(cachep, slabp, objp); |
2919 | |
2920 | cache_init_objs(cachep, slabp); |
2921 | |
2922 | if (local_flags & __GFP_WAIT) |
2923 | local_irq_disable(); |
2924 | check_irq_off(); |
2925 | spin_lock(&l3->list_lock); |
2926 | |
2927 | /* Make slab active. */ |
2928 | list_add_tail(&slabp->list, &(l3->slabs_free)); |
2929 | STATS_INC_GROWN(cachep); |
2930 | l3->free_objects += cachep->num; |
2931 | spin_unlock(&l3->list_lock); |
2932 | return 1; |
2933 | opps1: |
2934 | kmem_freepages(cachep, objp); |
2935 | failed: |
2936 | if (local_flags & __GFP_WAIT) |
2937 | local_irq_disable(); |
2938 | return 0; |
2939 | } |
2940 | |
2941 | #if DEBUG |
2942 | |
2943 | /* |
2944 | * Perform extra freeing checks: |
2945 | * - detect bad pointers. |
2946 | * - POISON/RED_ZONE checking |
2947 | */ |
2948 | static void kfree_debugcheck(const void *objp) |
2949 | { |
2950 | if (!virt_addr_valid(objp)) { |
2951 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
2952 | (unsigned long)objp); |
2953 | BUG(); |
2954 | } |
2955 | } |
2956 | |
2957 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) |
2958 | { |
2959 | unsigned long long redzone1, redzone2; |
2960 | |
2961 | redzone1 = *dbg_redzone1(cache, obj); |
2962 | redzone2 = *dbg_redzone2(cache, obj); |
2963 | |
2964 | /* |
2965 | * Redzone is ok. |
2966 | */ |
2967 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) |
2968 | return; |
2969 | |
2970 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) |
2971 | slab_error(cache, "double free detected"); |
2972 | else |
2973 | slab_error(cache, "memory outside object was overwritten"); |
2974 | |
2975 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", |
2976 | obj, redzone1, redzone2); |
2977 | } |
2978 | |
2979 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, |
2980 | void *caller) |
2981 | { |
2982 | struct page *page; |
2983 | unsigned int objnr; |
2984 | struct slab *slabp; |
2985 | |
2986 | BUG_ON(virt_to_cache(objp) != cachep); |
2987 | |
2988 | objp -= obj_offset(cachep); |
2989 | kfree_debugcheck(objp); |
2990 | page = virt_to_head_page(objp); |
2991 | |
2992 | slabp = page_get_slab(page); |
2993 | |
2994 | if (cachep->flags & SLAB_RED_ZONE) { |
2995 | verify_redzone_free(cachep, objp); |
2996 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2997 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2998 | } |
2999 | if (cachep->flags & SLAB_STORE_USER) |
3000 | *dbg_userword(cachep, objp) = caller; |
3001 | |
3002 | objnr = obj_to_index(cachep, slabp, objp); |
3003 | |
3004 | BUG_ON(objnr >= cachep->num); |
3005 | BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); |
3006 | |
3007 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
3008 | slab_bufctl(slabp)[objnr] = BUFCTL_FREE; |
3009 | #endif |
3010 | if (cachep->flags & SLAB_POISON) { |
3011 | #ifdef CONFIG_DEBUG_PAGEALLOC |
3012 | if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { |
3013 | store_stackinfo(cachep, objp, (unsigned long)caller); |
3014 | kernel_map_pages(virt_to_page(objp), |
3015 | cachep->buffer_size / PAGE_SIZE, 0); |
3016 | } else { |
3017 | poison_obj(cachep, objp, POISON_FREE); |
3018 | } |
3019 | #else |
3020 | poison_obj(cachep, objp, POISON_FREE); |
3021 | #endif |
3022 | } |
3023 | return objp; |
3024 | } |
3025 | |
3026 | static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) |
3027 | { |
3028 | kmem_bufctl_t i; |
3029 | int entries = 0; |
3030 | |
3031 | /* Check slab's freelist to see if this obj is there. */ |
3032 | for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { |
3033 | entries++; |
3034 | if (entries > cachep->num || i >= cachep->num) |
3035 | goto bad; |
3036 | } |
3037 | if (entries != cachep->num - slabp->inuse) { |
3038 | bad: |
3039 | printk(KERN_ERR "slab: Internal list corruption detected in " |
3040 | "cache '%s'(%d), slabp %p(%d). Hexdump:\n", |
3041 | cachep->name, cachep->num, slabp, slabp->inuse); |
3042 | for (i = 0; |
3043 | i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t); |
3044 | i++) { |
3045 | if (i % 16 == 0) |
3046 | printk("\n%03x:", i); |
3047 | printk(" %02x", ((unsigned char *)slabp)[i]); |
3048 | } |
3049 | printk("\n"); |
3050 | BUG(); |
3051 | } |
3052 | } |
3053 | #else |
3054 | #define kfree_debugcheck(x) do { } while(0) |
3055 | #define cache_free_debugcheck(x,objp,z) (objp) |
3056 | #define check_slabp(x,y) do { } while(0) |
3057 | #endif |
3058 | |
3059 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) |
3060 | { |
3061 | int batchcount; |
3062 | struct kmem_list3 *l3; |
3063 | struct array_cache *ac; |
3064 | int node; |
3065 | |
3066 | retry: |
3067 | check_irq_off(); |
3068 | node = numa_mem_id(); |
3069 | ac = cpu_cache_get(cachep); |
3070 | batchcount = ac->batchcount; |
3071 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
3072 | /* |
3073 | * If there was little recent activity on this cache, then |
3074 | * perform only a partial refill. Otherwise we could generate |
3075 | * refill bouncing. |
3076 | */ |
3077 | batchcount = BATCHREFILL_LIMIT; |
3078 | } |
3079 | l3 = cachep->nodelists[node]; |
3080 | |
3081 | BUG_ON(ac->avail > 0 || !l3); |
3082 | spin_lock(&l3->list_lock); |
3083 | |
3084 | /* See if we can refill from the shared array */ |
3085 | if (l3->shared && transfer_objects(ac, l3->shared, batchcount)) { |
3086 | l3->shared->touched = 1; |
3087 | goto alloc_done; |
3088 | } |
3089 | |
3090 | while (batchcount > 0) { |
3091 | struct list_head *entry; |
3092 | struct slab *slabp; |
3093 | /* Get slab alloc is to come from. */ |
3094 | entry = l3->slabs_partial.next; |
3095 | if (entry == &l3->slabs_partial) { |
3096 | l3->free_touched = 1; |
3097 | entry = l3->slabs_free.next; |
3098 | if (entry == &l3->slabs_free) |
3099 | goto must_grow; |
3100 | } |
3101 | |
3102 | slabp = list_entry(entry, struct slab, list); |
3103 | check_slabp(cachep, slabp); |
3104 | check_spinlock_acquired(cachep); |
3105 | |
3106 | /* |
3107 | * The slab was either on partial or free list so |
3108 | * there must be at least one object available for |
3109 | * allocation. |
3110 | */ |
3111 | BUG_ON(slabp->inuse >= cachep->num); |
3112 | |
3113 | while (slabp->inuse < cachep->num && batchcount--) { |
3114 | STATS_INC_ALLOCED(cachep); |
3115 | STATS_INC_ACTIVE(cachep); |
3116 | STATS_SET_HIGH(cachep); |
3117 | |
3118 | ac->entry[ac->avail++] = slab_get_obj(cachep, slabp, |
3119 | node); |
3120 | } |
3121 | check_slabp(cachep, slabp); |
3122 | |
3123 | /* move slabp to correct slabp list: */ |
3124 | list_del(&slabp->list); |
3125 | if (slabp->free == BUFCTL_END) |
3126 | list_add(&slabp->list, &l3->slabs_full); |
3127 | else |
3128 | list_add(&slabp->list, &l3->slabs_partial); |
3129 | } |
3130 | |
3131 | must_grow: |
3132 | l3->free_objects -= ac->avail; |
3133 | alloc_done: |
3134 | spin_unlock(&l3->list_lock); |
3135 | |
3136 | if (unlikely(!ac->avail)) { |
3137 | int x; |
3138 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); |
3139 | |
3140 | /* cache_grow can reenable interrupts, then ac could change. */ |
3141 | ac = cpu_cache_get(cachep); |
3142 | if (!x && ac->avail == 0) /* no objects in sight? abort */ |
3143 | return NULL; |
3144 | |
3145 | if (!ac->avail) /* objects refilled by interrupt? */ |
3146 | goto retry; |
3147 | } |
3148 | ac->touched = 1; |
3149 | return ac->entry[--ac->avail]; |
3150 | } |
3151 | |
3152 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, |
3153 | gfp_t flags) |
3154 | { |
3155 | might_sleep_if(flags & __GFP_WAIT); |
3156 | #if DEBUG |
3157 | kmem_flagcheck(cachep, flags); |
3158 | #endif |
3159 | } |
3160 | |
3161 | #if DEBUG |
3162 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, |
3163 | gfp_t flags, void *objp, void *caller) |
3164 | { |
3165 | if (!objp) |
3166 | return objp; |
3167 | if (cachep->flags & SLAB_POISON) { |
3168 | #ifdef CONFIG_DEBUG_PAGEALLOC |
3169 | if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
3170 | kernel_map_pages(virt_to_page(objp), |
3171 | cachep->buffer_size / PAGE_SIZE, 1); |
3172 | else |
3173 | check_poison_obj(cachep, objp); |
3174 | #else |
3175 | check_poison_obj(cachep, objp); |
3176 | #endif |
3177 | poison_obj(cachep, objp, POISON_INUSE); |
3178 | } |
3179 | if (cachep->flags & SLAB_STORE_USER) |
3180 | *dbg_userword(cachep, objp) = caller; |
3181 | |
3182 | if (cachep->flags & SLAB_RED_ZONE) { |
3183 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || |
3184 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
3185 | slab_error(cachep, "double free, or memory outside" |
3186 | " object was overwritten"); |
3187 | printk(KERN_ERR |
3188 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", |
3189 | objp, *dbg_redzone1(cachep, objp), |
3190 | *dbg_redzone2(cachep, objp)); |
3191 | } |
3192 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
3193 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
3194 | } |
3195 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
3196 | { |
3197 | struct slab *slabp; |
3198 | unsigned objnr; |
3199 | |
3200 | slabp = page_get_slab(virt_to_head_page(objp)); |
3201 | objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size; |
3202 | slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; |
3203 | } |
3204 | #endif |
3205 | objp += obj_offset(cachep); |
3206 | if (cachep->ctor && cachep->flags & SLAB_POISON) |
3207 | cachep->ctor(objp); |
3208 | if (ARCH_SLAB_MINALIGN && |
3209 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { |
3210 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", |
3211 | objp, (int)ARCH_SLAB_MINALIGN); |
3212 | } |
3213 | return objp; |
3214 | } |
3215 | #else |
3216 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
3217 | #endif |
3218 | |
3219 | static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) |
3220 | { |
3221 | if (cachep == &cache_cache) |
3222 | return false; |
3223 | |
3224 | return should_failslab(obj_size(cachep), flags, cachep->flags); |
3225 | } |
3226 | |
3227 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3228 | { |
3229 | void *objp; |
3230 | struct array_cache *ac; |
3231 | |
3232 | check_irq_off(); |
3233 | |
3234 | ac = cpu_cache_get(cachep); |
3235 | if (likely(ac->avail)) { |
3236 | STATS_INC_ALLOCHIT(cachep); |
3237 | ac->touched = 1; |
3238 | objp = ac->entry[--ac->avail]; |
3239 | } else { |
3240 | STATS_INC_ALLOCMISS(cachep); |
3241 | objp = cache_alloc_refill(cachep, flags); |
3242 | /* |
3243 | * the 'ac' may be updated by cache_alloc_refill(), |
3244 | * and kmemleak_erase() requires its correct value. |
3245 | */ |
3246 | ac = cpu_cache_get(cachep); |
3247 | } |
3248 | /* |
3249 | * To avoid a false negative, if an object that is in one of the |
3250 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't |
3251 | * treat the array pointers as a reference to the object. |
3252 | */ |
3253 | if (objp) |
3254 | kmemleak_erase(&ac->entry[ac->avail]); |
3255 | return objp; |
3256 | } |
3257 | |
3258 | #ifdef CONFIG_NUMA |
3259 | /* |
3260 | * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. |
3261 | * |
3262 | * If we are in_interrupt, then process context, including cpusets and |
3263 | * mempolicy, may not apply and should not be used for allocation policy. |
3264 | */ |
3265 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) |
3266 | { |
3267 | int nid_alloc, nid_here; |
3268 | |
3269 | if (in_interrupt() || (flags & __GFP_THISNODE)) |
3270 | return NULL; |
3271 | nid_alloc = nid_here = numa_mem_id(); |
3272 | get_mems_allowed(); |
3273 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) |
3274 | nid_alloc = cpuset_slab_spread_node(); |
3275 | else if (current->mempolicy) |
3276 | nid_alloc = slab_node(current->mempolicy); |
3277 | put_mems_allowed(); |
3278 | if (nid_alloc != nid_here) |
3279 | return ____cache_alloc_node(cachep, flags, nid_alloc); |
3280 | return NULL; |
3281 | } |
3282 | |
3283 | /* |
3284 | * Fallback function if there was no memory available and no objects on a |
3285 | * certain node and fall back is permitted. First we scan all the |
3286 | * available nodelists for available objects. If that fails then we |
3287 | * perform an allocation without specifying a node. This allows the page |
3288 | * allocator to do its reclaim / fallback magic. We then insert the |
3289 | * slab into the proper nodelist and then allocate from it. |
3290 | */ |
3291 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) |
3292 | { |
3293 | struct zonelist *zonelist; |
3294 | gfp_t local_flags; |
3295 | struct zoneref *z; |
3296 | struct zone *zone; |
3297 | enum zone_type high_zoneidx = gfp_zone(flags); |
3298 | void *obj = NULL; |
3299 | int nid; |
3300 | |
3301 | if (flags & __GFP_THISNODE) |
3302 | return NULL; |
3303 | |
3304 | get_mems_allowed(); |
3305 | zonelist = node_zonelist(slab_node(current->mempolicy), flags); |
3306 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
3307 | |
3308 | retry: |
3309 | /* |
3310 | * Look through allowed nodes for objects available |
3311 | * from existing per node queues. |
3312 | */ |
3313 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
3314 | nid = zone_to_nid(zone); |
3315 | |
3316 | if (cpuset_zone_allowed_hardwall(zone, flags) && |
3317 | cache->nodelists[nid] && |
3318 | cache->nodelists[nid]->free_objects) { |
3319 | obj = ____cache_alloc_node(cache, |
3320 | flags | GFP_THISNODE, nid); |
3321 | if (obj) |
3322 | break; |
3323 | } |
3324 | } |
3325 | |
3326 | if (!obj) { |
3327 | /* |
3328 | * This allocation will be performed within the constraints |
3329 | * of the current cpuset / memory policy requirements. |
3330 | * We may trigger various forms of reclaim on the allowed |
3331 | * set and go into memory reserves if necessary. |
3332 | */ |
3333 | if (local_flags & __GFP_WAIT) |
3334 | local_irq_enable(); |
3335 | kmem_flagcheck(cache, flags); |
3336 | obj = kmem_getpages(cache, local_flags, numa_mem_id()); |
3337 | if (local_flags & __GFP_WAIT) |
3338 | local_irq_disable(); |
3339 | if (obj) { |
3340 | /* |
3341 | * Insert into the appropriate per node queues |
3342 | */ |
3343 | nid = page_to_nid(virt_to_page(obj)); |
3344 | if (cache_grow(cache, flags, nid, obj)) { |
3345 | obj = ____cache_alloc_node(cache, |
3346 | flags | GFP_THISNODE, nid); |
3347 | if (!obj) |
3348 | /* |
3349 | * Another processor may allocate the |
3350 | * objects in the slab since we are |
3351 | * not holding any locks. |
3352 | */ |
3353 | goto retry; |
3354 | } else { |
3355 | /* cache_grow already freed obj */ |
3356 | obj = NULL; |
3357 | } |
3358 | } |
3359 | } |
3360 | put_mems_allowed(); |
3361 | return obj; |
3362 | } |
3363 | |
3364 | /* |
3365 | * A interface to enable slab creation on nodeid |
3366 | */ |
3367 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, |
3368 | int nodeid) |
3369 | { |
3370 | struct list_head *entry; |
3371 | struct slab *slabp; |
3372 | struct kmem_list3 *l3; |
3373 | void *obj; |
3374 | int x; |
3375 | |
3376 | l3 = cachep->nodelists[nodeid]; |
3377 | BUG_ON(!l3); |
3378 | |
3379 | retry: |
3380 | check_irq_off(); |
3381 | spin_lock(&l3->list_lock); |
3382 | entry = l3->slabs_partial.next; |
3383 | if (entry == &l3->slabs_partial) { |
3384 | l3->free_touched = 1; |
3385 | entry = l3->slabs_free.next; |
3386 | if (entry == &l3->slabs_free) |
3387 | goto must_grow; |
3388 | } |
3389 | |
3390 | slabp = list_entry(entry, struct slab, list); |
3391 | check_spinlock_acquired_node(cachep, nodeid); |
3392 | check_slabp(cachep, slabp); |
3393 | |
3394 | STATS_INC_NODEALLOCS(cachep); |
3395 | STATS_INC_ACTIVE(cachep); |
3396 | STATS_SET_HIGH(cachep); |
3397 | |
3398 | BUG_ON(slabp->inuse == cachep->num); |
3399 | |
3400 | obj = slab_get_obj(cachep, slabp, nodeid); |
3401 | check_slabp(cachep, slabp); |
3402 | l3->free_objects--; |
3403 | /* move slabp to correct slabp list: */ |
3404 | list_del(&slabp->list); |
3405 | |
3406 | if (slabp->free == BUFCTL_END) |
3407 | list_add(&slabp->list, &l3->slabs_full); |
3408 | else |
3409 | list_add(&slabp->list, &l3->slabs_partial); |
3410 | |
3411 | spin_unlock(&l3->list_lock); |
3412 | goto done; |
3413 | |
3414 | must_grow: |
3415 | spin_unlock(&l3->list_lock); |
3416 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); |
3417 | if (x) |
3418 | goto retry; |
3419 | |
3420 | return fallback_alloc(cachep, flags); |
3421 | |
3422 | done: |
3423 | return obj; |
3424 | } |
3425 | |
3426 | /** |
3427 | * kmem_cache_alloc_node - Allocate an object on the specified node |
3428 | * @cachep: The cache to allocate from. |
3429 | * @flags: See kmalloc(). |
3430 | * @nodeid: node number of the target node. |
3431 | * @caller: return address of caller, used for debug information |
3432 | * |
3433 | * Identical to kmem_cache_alloc but it will allocate memory on the given |
3434 | * node, which can improve the performance for cpu bound structures. |
3435 | * |
3436 | * Fallback to other node is possible if __GFP_THISNODE is not set. |
3437 | */ |
3438 | static __always_inline void * |
3439 | __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, |
3440 | void *caller) |
3441 | { |
3442 | unsigned long save_flags; |
3443 | void *ptr; |
3444 | int slab_node = numa_mem_id(); |
3445 | |
3446 | flags &= gfp_allowed_mask; |
3447 | |
3448 | lockdep_trace_alloc(flags); |
3449 | |
3450 | if (slab_should_failslab(cachep, flags)) |
3451 | return NULL; |
3452 | |
3453 | cache_alloc_debugcheck_before(cachep, flags); |
3454 | local_irq_save(save_flags); |
3455 | |
3456 | if (nodeid == NUMA_NO_NODE) |
3457 | nodeid = slab_node; |
3458 | |
3459 | if (unlikely(!cachep->nodelists[nodeid])) { |
3460 | /* Node not bootstrapped yet */ |
3461 | ptr = fallback_alloc(cachep, flags); |
3462 | goto out; |
3463 | } |
3464 | |
3465 | if (nodeid == slab_node) { |
3466 | /* |
3467 | * Use the locally cached objects if possible. |
3468 | * However ____cache_alloc does not allow fallback |
3469 | * to other nodes. It may fail while we still have |
3470 | * objects on other nodes available. |
3471 | */ |
3472 | ptr = ____cache_alloc(cachep, flags); |
3473 | if (ptr) |
3474 | goto out; |
3475 | } |
3476 | /* ___cache_alloc_node can fall back to other nodes */ |
3477 | ptr = ____cache_alloc_node(cachep, flags, nodeid); |
3478 | out: |
3479 | local_irq_restore(save_flags); |
3480 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
3481 | kmemleak_alloc_recursive(ptr, obj_size(cachep), 1, cachep->flags, |
3482 | flags); |
3483 | |
3484 | if (likely(ptr)) |
3485 | kmemcheck_slab_alloc(cachep, flags, ptr, obj_size(cachep)); |
3486 | |
3487 | if (unlikely((flags & __GFP_ZERO) && ptr)) |
3488 | memset(ptr, 0, obj_size(cachep)); |
3489 | |
3490 | return ptr; |
3491 | } |
3492 | |
3493 | static __always_inline void * |
3494 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) |
3495 | { |
3496 | void *objp; |
3497 | |
3498 | if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { |
3499 | objp = alternate_node_alloc(cache, flags); |
3500 | if (objp) |
3501 | goto out; |
3502 | } |
3503 | objp = ____cache_alloc(cache, flags); |
3504 | |
3505 | /* |
3506 | * We may just have run out of memory on the local node. |
3507 | * ____cache_alloc_node() knows how to locate memory on other nodes |
3508 | */ |
3509 | if (!objp) |
3510 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); |
3511 | |
3512 | out: |
3513 | return objp; |
3514 | } |
3515 | #else |
3516 | |
3517 | static __always_inline void * |
3518 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3519 | { |
3520 | return ____cache_alloc(cachep, flags); |
3521 | } |
3522 | |
3523 | #endif /* CONFIG_NUMA */ |
3524 | |
3525 | static __always_inline void * |
3526 | __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) |
3527 | { |
3528 | unsigned long save_flags; |
3529 | void *objp; |
3530 | |
3531 | flags &= gfp_allowed_mask; |
3532 | |
3533 | lockdep_trace_alloc(flags); |
3534 | |
3535 | if (slab_should_failslab(cachep, flags)) |
3536 | return NULL; |
3537 | |
3538 | cache_alloc_debugcheck_before(cachep, flags); |
3539 | local_irq_save(save_flags); |
3540 | objp = __do_cache_alloc(cachep, flags); |
3541 | local_irq_restore(save_flags); |
3542 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
3543 | kmemleak_alloc_recursive(objp, obj_size(cachep), 1, cachep->flags, |
3544 | flags); |
3545 | prefetchw(objp); |
3546 | |
3547 | if (likely(objp)) |
3548 | kmemcheck_slab_alloc(cachep, flags, objp, obj_size(cachep)); |
3549 | |
3550 | if (unlikely((flags & __GFP_ZERO) && objp)) |
3551 | memset(objp, 0, obj_size(cachep)); |
3552 | |
3553 | return objp; |
3554 | } |
3555 | |
3556 | /* |
3557 | * Caller needs to acquire correct kmem_list's list_lock |
3558 | */ |
3559 | static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, |
3560 | int node) |
3561 | { |
3562 | int i; |
3563 | struct kmem_list3 *l3; |
3564 | |
3565 | for (i = 0; i < nr_objects; i++) { |
3566 | void *objp = objpp[i]; |
3567 | struct slab *slabp; |
3568 | |
3569 | slabp = virt_to_slab(objp); |
3570 | l3 = cachep->nodelists[node]; |
3571 | list_del(&slabp->list); |
3572 | check_spinlock_acquired_node(cachep, node); |
3573 | check_slabp(cachep, slabp); |
3574 | slab_put_obj(cachep, slabp, objp, node); |
3575 | STATS_DEC_ACTIVE(cachep); |
3576 | l3->free_objects++; |
3577 | check_slabp(cachep, slabp); |
3578 | |
3579 | /* fixup slab chains */ |
3580 | if (slabp->inuse == 0) { |
3581 | if (l3->free_objects > l3->free_limit) { |
3582 | l3->free_objects -= cachep->num; |
3583 | /* No need to drop any previously held |
3584 | * lock here, even if we have a off-slab slab |
3585 | * descriptor it is guaranteed to come from |
3586 | * a different cache, refer to comments before |
3587 | * alloc_slabmgmt. |
3588 | */ |
3589 | slab_destroy(cachep, slabp); |
3590 | } else { |
3591 | list_add(&slabp->list, &l3->slabs_free); |
3592 | } |
3593 | } else { |
3594 | /* Unconditionally move a slab to the end of the |
3595 | * partial list on free - maximum time for the |
3596 | * other objects to be freed, too. |
3597 | */ |
3598 | list_add_tail(&slabp->list, &l3->slabs_partial); |
3599 | } |
3600 | } |
3601 | } |
3602 | |
3603 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) |
3604 | { |
3605 | int batchcount; |
3606 | struct kmem_list3 *l3; |
3607 | int node = numa_mem_id(); |
3608 | |
3609 | batchcount = ac->batchcount; |
3610 | #if DEBUG |
3611 | BUG_ON(!batchcount || batchcount > ac->avail); |
3612 | #endif |
3613 | check_irq_off(); |
3614 | l3 = cachep->nodelists[node]; |
3615 | spin_lock(&l3->list_lock); |
3616 | if (l3->shared) { |
3617 | struct array_cache *shared_array = l3->shared; |
3618 | int max = shared_array->limit - shared_array->avail; |
3619 | if (max) { |
3620 | if (batchcount > max) |
3621 | batchcount = max; |
3622 | memcpy(&(shared_array->entry[shared_array->avail]), |
3623 | ac->entry, sizeof(void *) * batchcount); |
3624 | shared_array->avail += batchcount; |
3625 | goto free_done; |
3626 | } |
3627 | } |
3628 | |
3629 | free_block(cachep, ac->entry, batchcount, node); |
3630 | free_done: |
3631 | #if STATS |
3632 | { |
3633 | int i = 0; |
3634 | struct list_head *p; |
3635 | |
3636 | p = l3->slabs_free.next; |
3637 | while (p != &(l3->slabs_free)) { |
3638 | struct slab *slabp; |
3639 | |
3640 | slabp = list_entry(p, struct slab, list); |
3641 | BUG_ON(slabp->inuse); |
3642 | |
3643 | i++; |
3644 | p = p->next; |
3645 | } |
3646 | STATS_SET_FREEABLE(cachep, i); |
3647 | } |
3648 | #endif |
3649 | spin_unlock(&l3->list_lock); |
3650 | ac->avail -= batchcount; |
3651 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); |
3652 | } |
3653 | |
3654 | /* |
3655 | * Release an obj back to its cache. If the obj has a constructed state, it must |
3656 | * be in this state _before_ it is released. Called with disabled ints. |
3657 | */ |
3658 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, |
3659 | void *caller) |
3660 | { |
3661 | struct array_cache *ac = cpu_cache_get(cachep); |
3662 | |
3663 | check_irq_off(); |
3664 | kmemleak_free_recursive(objp, cachep->flags); |
3665 | objp = cache_free_debugcheck(cachep, objp, caller); |
3666 | |
3667 | kmemcheck_slab_free(cachep, objp, obj_size(cachep)); |
3668 | |
3669 | /* |
3670 | * Skip calling cache_free_alien() when the platform is not numa. |
3671 | * This will avoid cache misses that happen while accessing slabp (which |
3672 | * is per page memory reference) to get nodeid. Instead use a global |
3673 | * variable to skip the call, which is mostly likely to be present in |
3674 | * the cache. |
3675 | */ |
3676 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) |
3677 | return; |
3678 | |
3679 | if (likely(ac->avail < ac->limit)) { |
3680 | STATS_INC_FREEHIT(cachep); |
3681 | ac->entry[ac->avail++] = objp; |
3682 | return; |
3683 | } else { |
3684 | STATS_INC_FREEMISS(cachep); |
3685 | cache_flusharray(cachep, ac); |
3686 | ac->entry[ac->avail++] = objp; |
3687 | } |
3688 | } |
3689 | |
3690 | /** |
3691 | * kmem_cache_alloc - Allocate an object |
3692 | * @cachep: The cache to allocate from. |
3693 | * @flags: See kmalloc(). |
3694 | * |
3695 | * Allocate an object from this cache. The flags are only relevant |
3696 | * if the cache has no available objects. |
3697 | */ |
3698 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3699 | { |
3700 | void *ret = __cache_alloc(cachep, flags, __builtin_return_address(0)); |
3701 | |
3702 | trace_kmem_cache_alloc(_RET_IP_, ret, |
3703 | obj_size(cachep), cachep->buffer_size, flags); |
3704 | |
3705 | return ret; |
3706 | } |
3707 | EXPORT_SYMBOL(kmem_cache_alloc); |
3708 | |
3709 | #ifdef CONFIG_TRACING |
3710 | void * |
3711 | kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags) |
3712 | { |
3713 | void *ret; |
3714 | |
3715 | ret = __cache_alloc(cachep, flags, __builtin_return_address(0)); |
3716 | |
3717 | trace_kmalloc(_RET_IP_, ret, |
3718 | size, slab_buffer_size(cachep), flags); |
3719 | return ret; |
3720 | } |
3721 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
3722 | #endif |
3723 | |
3724 | #ifdef CONFIG_NUMA |
3725 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
3726 | { |
3727 | void *ret = __cache_alloc_node(cachep, flags, nodeid, |
3728 | __builtin_return_address(0)); |
3729 | |
3730 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
3731 | obj_size(cachep), cachep->buffer_size, |
3732 | flags, nodeid); |
3733 | |
3734 | return ret; |
3735 | } |
3736 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
3737 | |
3738 | #ifdef CONFIG_TRACING |
3739 | void *kmem_cache_alloc_node_trace(size_t size, |
3740 | struct kmem_cache *cachep, |
3741 | gfp_t flags, |
3742 | int nodeid) |
3743 | { |
3744 | void *ret; |
3745 | |
3746 | ret = __cache_alloc_node(cachep, flags, nodeid, |
3747 | __builtin_return_address(0)); |
3748 | trace_kmalloc_node(_RET_IP_, ret, |
3749 | size, slab_buffer_size(cachep), |
3750 | flags, nodeid); |
3751 | return ret; |
3752 | } |
3753 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
3754 | #endif |
3755 | |
3756 | static __always_inline void * |
3757 | __do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller) |
3758 | { |
3759 | struct kmem_cache *cachep; |
3760 | |
3761 | cachep = kmem_find_general_cachep(size, flags); |
3762 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3763 | return cachep; |
3764 | return kmem_cache_alloc_node_trace(size, cachep, flags, node); |
3765 | } |
3766 | |
3767 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3768 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3769 | { |
3770 | return __do_kmalloc_node(size, flags, node, |
3771 | __builtin_return_address(0)); |
3772 | } |
3773 | EXPORT_SYMBOL(__kmalloc_node); |
3774 | |
3775 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, |
3776 | int node, unsigned long caller) |
3777 | { |
3778 | return __do_kmalloc_node(size, flags, node, (void *)caller); |
3779 | } |
3780 | EXPORT_SYMBOL(__kmalloc_node_track_caller); |
3781 | #else |
3782 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3783 | { |
3784 | return __do_kmalloc_node(size, flags, node, NULL); |
3785 | } |
3786 | EXPORT_SYMBOL(__kmalloc_node); |
3787 | #endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ |
3788 | #endif /* CONFIG_NUMA */ |
3789 | |
3790 | /** |
3791 | * __do_kmalloc - allocate memory |
3792 | * @size: how many bytes of memory are required. |
3793 | * @flags: the type of memory to allocate (see kmalloc). |
3794 | * @caller: function caller for debug tracking of the caller |
3795 | */ |
3796 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, |
3797 | void *caller) |
3798 | { |
3799 | struct kmem_cache *cachep; |
3800 | void *ret; |
3801 | |
3802 | /* If you want to save a few bytes .text space: replace |
3803 | * __ with kmem_. |
3804 | * Then kmalloc uses the uninlined functions instead of the inline |
3805 | * functions. |
3806 | */ |
3807 | cachep = __find_general_cachep(size, flags); |
3808 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3809 | return cachep; |
3810 | ret = __cache_alloc(cachep, flags, caller); |
3811 | |
3812 | trace_kmalloc((unsigned long) caller, ret, |
3813 | size, cachep->buffer_size, flags); |
3814 | |
3815 | return ret; |
3816 | } |
3817 | |
3818 | |
3819 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) |
3820 | void *__kmalloc(size_t size, gfp_t flags) |
3821 | { |
3822 | return __do_kmalloc(size, flags, __builtin_return_address(0)); |
3823 | } |
3824 | EXPORT_SYMBOL(__kmalloc); |
3825 | |
3826 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) |
3827 | { |
3828 | return __do_kmalloc(size, flags, (void *)caller); |
3829 | } |
3830 | EXPORT_SYMBOL(__kmalloc_track_caller); |
3831 | |
3832 | #else |
3833 | void *__kmalloc(size_t size, gfp_t flags) |
3834 | { |
3835 | return __do_kmalloc(size, flags, NULL); |
3836 | } |
3837 | EXPORT_SYMBOL(__kmalloc); |
3838 | #endif |
3839 | |
3840 | /** |
3841 | * kmem_cache_free - Deallocate an object |
3842 | * @cachep: The cache the allocation was from. |
3843 | * @objp: The previously allocated object. |
3844 | * |
3845 | * Free an object which was previously allocated from this |
3846 | * cache. |
3847 | */ |
3848 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) |
3849 | { |
3850 | unsigned long flags; |
3851 | |
3852 | local_irq_save(flags); |
3853 | debug_check_no_locks_freed(objp, obj_size(cachep)); |
3854 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) |
3855 | debug_check_no_obj_freed(objp, obj_size(cachep)); |
3856 | __cache_free(cachep, objp, __builtin_return_address(0)); |
3857 | local_irq_restore(flags); |
3858 | |
3859 | trace_kmem_cache_free(_RET_IP_, objp); |
3860 | } |
3861 | EXPORT_SYMBOL(kmem_cache_free); |
3862 | |
3863 | /** |
3864 | * kfree - free previously allocated memory |
3865 | * @objp: pointer returned by kmalloc. |
3866 | * |
3867 | * If @objp is NULL, no operation is performed. |
3868 | * |
3869 | * Don't free memory not originally allocated by kmalloc() |
3870 | * or you will run into trouble. |
3871 | */ |
3872 | void kfree(const void *objp) |
3873 | { |
3874 | struct kmem_cache *c; |
3875 | unsigned long flags; |
3876 | |
3877 | trace_kfree(_RET_IP_, objp); |
3878 | |
3879 | if (unlikely(ZERO_OR_NULL_PTR(objp))) |
3880 | return; |
3881 | local_irq_save(flags); |
3882 | kfree_debugcheck(objp); |
3883 | c = virt_to_cache(objp); |
3884 | debug_check_no_locks_freed(objp, obj_size(c)); |
3885 | debug_check_no_obj_freed(objp, obj_size(c)); |
3886 | __cache_free(c, (void *)objp, __builtin_return_address(0)); |
3887 | local_irq_restore(flags); |
3888 | } |
3889 | EXPORT_SYMBOL(kfree); |
3890 | |
3891 | unsigned int kmem_cache_size(struct kmem_cache *cachep) |
3892 | { |
3893 | return obj_size(cachep); |
3894 | } |
3895 | EXPORT_SYMBOL(kmem_cache_size); |
3896 | |
3897 | /* |
3898 | * This initializes kmem_list3 or resizes various caches for all nodes. |
3899 | */ |
3900 | static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) |
3901 | { |
3902 | int node; |
3903 | struct kmem_list3 *l3; |
3904 | struct array_cache *new_shared; |
3905 | struct array_cache **new_alien = NULL; |
3906 | |
3907 | for_each_online_node(node) { |
3908 | |
3909 | if (use_alien_caches) { |
3910 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); |
3911 | if (!new_alien) |
3912 | goto fail; |
3913 | } |
3914 | |
3915 | new_shared = NULL; |
3916 | if (cachep->shared) { |
3917 | new_shared = alloc_arraycache(node, |
3918 | cachep->shared*cachep->batchcount, |
3919 | 0xbaadf00d, gfp); |
3920 | if (!new_shared) { |
3921 | free_alien_cache(new_alien); |
3922 | goto fail; |
3923 | } |
3924 | } |
3925 | |
3926 | l3 = cachep->nodelists[node]; |
3927 | if (l3) { |
3928 | struct array_cache *shared = l3->shared; |
3929 | |
3930 | spin_lock_irq(&l3->list_lock); |
3931 | |
3932 | if (shared) |
3933 | free_block(cachep, shared->entry, |
3934 | shared->avail, node); |
3935 | |
3936 | l3->shared = new_shared; |
3937 | if (!l3->alien) { |
3938 | l3->alien = new_alien; |
3939 | new_alien = NULL; |
3940 | } |
3941 | l3->free_limit = (1 + nr_cpus_node(node)) * |
3942 | cachep->batchcount + cachep->num; |
3943 | spin_unlock_irq(&l3->list_lock); |
3944 | kfree(shared); |
3945 | free_alien_cache(new_alien); |
3946 | continue; |
3947 | } |
3948 | l3 = kmalloc_node(sizeof(struct kmem_list3), gfp, node); |
3949 | if (!l3) { |
3950 | free_alien_cache(new_alien); |
3951 | kfree(new_shared); |
3952 | goto fail; |
3953 | } |
3954 | |
3955 | kmem_list3_init(l3); |
3956 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + |
3957 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; |
3958 | l3->shared = new_shared; |
3959 | l3->alien = new_alien; |
3960 | l3->free_limit = (1 + nr_cpus_node(node)) * |
3961 | cachep->batchcount + cachep->num; |
3962 | cachep->nodelists[node] = l3; |
3963 | } |
3964 | return 0; |
3965 | |
3966 | fail: |
3967 | if (!cachep->next.next) { |
3968 | /* Cache is not active yet. Roll back what we did */ |
3969 | node--; |
3970 | while (node >= 0) { |
3971 | if (cachep->nodelists[node]) { |
3972 | l3 = cachep->nodelists[node]; |
3973 | |
3974 | kfree(l3->shared); |
3975 | free_alien_cache(l3->alien); |
3976 | kfree(l3); |
3977 | cachep->nodelists[node] = NULL; |
3978 | } |
3979 | node--; |
3980 | } |
3981 | } |
3982 | return -ENOMEM; |
3983 | } |
3984 | |
3985 | struct ccupdate_struct { |
3986 | struct kmem_cache *cachep; |
3987 | struct array_cache *new[0]; |
3988 | }; |
3989 | |
3990 | static void do_ccupdate_local(void *info) |
3991 | { |
3992 | struct ccupdate_struct *new = info; |
3993 | struct array_cache *old; |
3994 | |
3995 | check_irq_off(); |
3996 | old = cpu_cache_get(new->cachep); |
3997 | |
3998 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; |
3999 | new->new[smp_processor_id()] = old; |
4000 | } |
4001 | |
4002 | /* Always called with the cache_chain_mutex held */ |
4003 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, |
4004 | int batchcount, int shared, gfp_t gfp) |
4005 | { |
4006 | struct ccupdate_struct *new; |
4007 | int i; |
4008 | |
4009 | new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *), |
4010 | gfp); |
4011 | if (!new) |
4012 | return -ENOMEM; |
4013 | |
4014 | for_each_online_cpu(i) { |
4015 | new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, |
4016 | batchcount, gfp); |
4017 | if (!new->new[i]) { |
4018 | for (i--; i >= 0; i--) |
4019 | kfree(new->new[i]); |
4020 | kfree(new); |
4021 | return -ENOMEM; |
4022 | } |
4023 | } |
4024 | new->cachep = cachep; |
4025 | |
4026 | on_each_cpu(do_ccupdate_local, (void *)new, 1); |
4027 | |
4028 | check_irq_on(); |
4029 | cachep->batchcount = batchcount; |
4030 | cachep->limit = limit; |
4031 | cachep->shared = shared; |
4032 | |
4033 | for_each_online_cpu(i) { |
4034 | struct array_cache *ccold = new->new[i]; |
4035 | if (!ccold) |
4036 | continue; |
4037 | spin_lock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); |
4038 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); |
4039 | spin_unlock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); |
4040 | kfree(ccold); |
4041 | } |
4042 | kfree(new); |
4043 | return alloc_kmemlist(cachep, gfp); |
4044 | } |
4045 | |
4046 | /* Called with cache_chain_mutex held always */ |
4047 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) |
4048 | { |
4049 | int err; |
4050 | int limit, shared; |
4051 | |
4052 | /* |
4053 | * The head array serves three purposes: |
4054 | * - create a LIFO ordering, i.e. return objects that are cache-warm |
4055 | * - reduce the number of spinlock operations. |
4056 | * - reduce the number of linked list operations on the slab and |
4057 | * bufctl chains: array operations are cheaper. |
4058 | * The numbers are guessed, we should auto-tune as described by |
4059 | * Bonwick. |
4060 | */ |
4061 | if (cachep->buffer_size > 131072) |
4062 | limit = 1; |
4063 | else if (cachep->buffer_size > PAGE_SIZE) |
4064 | limit = 8; |
4065 | else if (cachep->buffer_size > 1024) |
4066 | limit = 24; |
4067 | else if (cachep->buffer_size > 256) |
4068 | limit = 54; |
4069 | else |
4070 | limit = 120; |
4071 | |
4072 | /* |
4073 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound |
4074 | * allocation behaviour: Most allocs on one cpu, most free operations |
4075 | * on another cpu. For these cases, an efficient object passing between |
4076 | * cpus is necessary. This is provided by a shared array. The array |
4077 | * replaces Bonwick's magazine layer. |
4078 | * On uniprocessor, it's functionally equivalent (but less efficient) |
4079 | * to a larger limit. Thus disabled by default. |
4080 | */ |
4081 | shared = 0; |
4082 | if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1) |
4083 | shared = 8; |
4084 | |
4085 | #if DEBUG |
4086 | /* |
4087 | * With debugging enabled, large batchcount lead to excessively long |
4088 | * periods with disabled local interrupts. Limit the batchcount |
4089 | */ |
4090 | if (limit > 32) |
4091 | limit = 32; |
4092 | #endif |
4093 | err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared, gfp); |
4094 | if (err) |
4095 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", |
4096 | cachep->name, -err); |
4097 | return err; |
4098 | } |
4099 | |
4100 | /* |
4101 | * Drain an array if it contains any elements taking the l3 lock only if |
4102 | * necessary. Note that the l3 listlock also protects the array_cache |
4103 | * if drain_array() is used on the shared array. |
4104 | */ |
4105 | static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, |
4106 | struct array_cache *ac, int force, int node) |
4107 | { |
4108 | int tofree; |
4109 | |
4110 | if (!ac || !ac->avail) |
4111 | return; |
4112 | if (ac->touched && !force) { |
4113 | ac->touched = 0; |
4114 | } else { |
4115 | spin_lock_irq(&l3->list_lock); |
4116 | if (ac->avail) { |
4117 | tofree = force ? ac->avail : (ac->limit + 4) / 5; |
4118 | if (tofree > ac->avail) |
4119 | tofree = (ac->avail + 1) / 2; |
4120 | free_block(cachep, ac->entry, tofree, node); |
4121 | ac->avail -= tofree; |
4122 | memmove(ac->entry, &(ac->entry[tofree]), |
4123 | sizeof(void *) * ac->avail); |
4124 | } |
4125 | spin_unlock_irq(&l3->list_lock); |
4126 | } |
4127 | } |
4128 | |
4129 | /** |
4130 | * cache_reap - Reclaim memory from caches. |
4131 | * @w: work descriptor |
4132 | * |
4133 | * Called from workqueue/eventd every few seconds. |
4134 | * Purpose: |
4135 | * - clear the per-cpu caches for this CPU. |
4136 | * - return freeable pages to the main free memory pool. |
4137 | * |
4138 | * If we cannot acquire the cache chain mutex then just give up - we'll try |
4139 | * again on the next iteration. |
4140 | */ |
4141 | static void cache_reap(struct work_struct *w) |
4142 | { |
4143 | struct kmem_cache *searchp; |
4144 | struct kmem_list3 *l3; |
4145 | int node = numa_mem_id(); |
4146 | struct delayed_work *work = to_delayed_work(w); |
4147 | |
4148 | if (!mutex_trylock(&cache_chain_mutex)) |
4149 | /* Give up. Setup the next iteration. */ |
4150 | goto out; |
4151 | |
4152 | list_for_each_entry(searchp, &cache_chain, next) { |
4153 | check_irq_on(); |
4154 | |
4155 | /* |
4156 | * We only take the l3 lock if absolutely necessary and we |
4157 | * have established with reasonable certainty that |
4158 | * we can do some work if the lock was obtained. |
4159 | */ |
4160 | l3 = searchp->nodelists[node]; |
4161 | |
4162 | reap_alien(searchp, l3); |
4163 | |
4164 | drain_array(searchp, l3, cpu_cache_get(searchp), 0, node); |
4165 | |
4166 | /* |
4167 | * These are racy checks but it does not matter |
4168 | * if we skip one check or scan twice. |
4169 | */ |
4170 | if (time_after(l3->next_reap, jiffies)) |
4171 | goto next; |
4172 | |
4173 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3; |
4174 | |
4175 | drain_array(searchp, l3, l3->shared, 0, node); |
4176 | |
4177 | if (l3->free_touched) |
4178 | l3->free_touched = 0; |
4179 | else { |
4180 | int freed; |
4181 | |
4182 | freed = drain_freelist(searchp, l3, (l3->free_limit + |
4183 | 5 * searchp->num - 1) / (5 * searchp->num)); |
4184 | STATS_ADD_REAPED(searchp, freed); |
4185 | } |
4186 | next: |
4187 | cond_resched(); |
4188 | } |
4189 | check_irq_on(); |
4190 | mutex_unlock(&cache_chain_mutex); |
4191 | next_reap_node(); |
4192 | out: |
4193 | /* Set up the next iteration */ |
4194 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); |
4195 | } |
4196 | |
4197 | #ifdef CONFIG_SLABINFO |
4198 | |
4199 | static void print_slabinfo_header(struct seq_file *m) |
4200 | { |
4201 | /* |
4202 | * Output format version, so at least we can change it |
4203 | * without _too_ many complaints. |
4204 | */ |
4205 | #if STATS |
4206 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); |
4207 | #else |
4208 | seq_puts(m, "slabinfo - version: 2.1\n"); |
4209 | #endif |
4210 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " |
4211 | "<objperslab> <pagesperslab>"); |
4212 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
4213 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); |
4214 | #if STATS |
4215 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " |
4216 | "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); |
4217 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); |
4218 | #endif |
4219 | seq_putc(m, '\n'); |
4220 | } |
4221 | |
4222 | static void *s_start(struct seq_file *m, loff_t *pos) |
4223 | { |
4224 | loff_t n = *pos; |
4225 | |
4226 | mutex_lock(&cache_chain_mutex); |
4227 | if (!n) |
4228 | print_slabinfo_header(m); |
4229 | |
4230 | return seq_list_start(&cache_chain, *pos); |
4231 | } |
4232 | |
4233 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) |
4234 | { |
4235 | return seq_list_next(p, &cache_chain, pos); |
4236 | } |
4237 | |
4238 | static void s_stop(struct seq_file *m, void *p) |
4239 | { |
4240 | mutex_unlock(&cache_chain_mutex); |
4241 | } |
4242 | |
4243 | static int s_show(struct seq_file *m, void *p) |
4244 | { |
4245 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next); |
4246 | struct slab *slabp; |
4247 | unsigned long active_objs; |
4248 | unsigned long num_objs; |
4249 | unsigned long active_slabs = 0; |
4250 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; |
4251 | const char *name; |
4252 | char *error = NULL; |
4253 | int node; |
4254 | struct kmem_list3 *l3; |
4255 | |
4256 | active_objs = 0; |
4257 | num_slabs = 0; |
4258 | for_each_online_node(node) { |
4259 | l3 = cachep->nodelists[node]; |
4260 | if (!l3) |
4261 | continue; |
4262 | |
4263 | check_irq_on(); |
4264 | spin_lock_irq(&l3->list_lock); |
4265 | |
4266 | list_for_each_entry(slabp, &l3->slabs_full, list) { |
4267 | if (slabp->inuse != cachep->num && !error) |
4268 | error = "slabs_full accounting error"; |
4269 | active_objs += cachep->num; |
4270 | active_slabs++; |
4271 | } |
4272 | list_for_each_entry(slabp, &l3->slabs_partial, list) { |
4273 | if (slabp->inuse == cachep->num && !error) |
4274 | error = "slabs_partial inuse accounting error"; |
4275 | if (!slabp->inuse && !error) |
4276 | error = "slabs_partial/inuse accounting error"; |
4277 | active_objs += slabp->inuse; |
4278 | active_slabs++; |
4279 | } |
4280 | list_for_each_entry(slabp, &l3->slabs_free, list) { |
4281 | if (slabp->inuse && !error) |
4282 | error = "slabs_free/inuse accounting error"; |
4283 | num_slabs++; |
4284 | } |
4285 | free_objects += l3->free_objects; |
4286 | if (l3->shared) |
4287 | shared_avail += l3->shared->avail; |
4288 | |
4289 | spin_unlock_irq(&l3->list_lock); |
4290 | } |
4291 | num_slabs += active_slabs; |
4292 | num_objs = num_slabs * cachep->num; |
4293 | if (num_objs - active_objs != free_objects && !error) |
4294 | error = "free_objects accounting error"; |
4295 | |
4296 | name = cachep->name; |
4297 | if (error) |
4298 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); |
4299 | |
4300 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
4301 | name, active_objs, num_objs, cachep->buffer_size, |
4302 | cachep->num, (1 << cachep->gfporder)); |
4303 | seq_printf(m, " : tunables %4u %4u %4u", |
4304 | cachep->limit, cachep->batchcount, cachep->shared); |
4305 | seq_printf(m, " : slabdata %6lu %6lu %6lu", |
4306 | active_slabs, num_slabs, shared_avail); |
4307 | #if STATS |
4308 | { /* list3 stats */ |
4309 | unsigned long high = cachep->high_mark; |
4310 | unsigned long allocs = cachep->num_allocations; |
4311 | unsigned long grown = cachep->grown; |
4312 | unsigned long reaped = cachep->reaped; |
4313 | unsigned long errors = cachep->errors; |
4314 | unsigned long max_freeable = cachep->max_freeable; |
4315 | unsigned long node_allocs = cachep->node_allocs; |
4316 | unsigned long node_frees = cachep->node_frees; |
4317 | unsigned long overflows = cachep->node_overflow; |
4318 | |
4319 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " |
4320 | "%4lu %4lu %4lu %4lu %4lu", |
4321 | allocs, high, grown, |
4322 | reaped, errors, max_freeable, node_allocs, |
4323 | node_frees, overflows); |
4324 | } |
4325 | /* cpu stats */ |
4326 | { |
4327 | unsigned long allochit = atomic_read(&cachep->allochit); |
4328 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
4329 | unsigned long freehit = atomic_read(&cachep->freehit); |
4330 | unsigned long freemiss = atomic_read(&cachep->freemiss); |
4331 | |
4332 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
4333 | allochit, allocmiss, freehit, freemiss); |
4334 | } |
4335 | #endif |
4336 | seq_putc(m, '\n'); |
4337 | return 0; |
4338 | } |
4339 | |
4340 | /* |
4341 | * slabinfo_op - iterator that generates /proc/slabinfo |
4342 | * |
4343 | * Output layout: |
4344 | * cache-name |
4345 | * num-active-objs |
4346 | * total-objs |
4347 | * object size |
4348 | * num-active-slabs |
4349 | * total-slabs |
4350 | * num-pages-per-slab |
4351 | * + further values on SMP and with statistics enabled |
4352 | */ |
4353 | |
4354 | static const struct seq_operations slabinfo_op = { |
4355 | .start = s_start, |
4356 | .next = s_next, |
4357 | .stop = s_stop, |
4358 | .show = s_show, |
4359 | }; |
4360 | |
4361 | #define MAX_SLABINFO_WRITE 128 |
4362 | /** |
4363 | * slabinfo_write - Tuning for the slab allocator |
4364 | * @file: unused |
4365 | * @buffer: user buffer |
4366 | * @count: data length |
4367 | * @ppos: unused |
4368 | */ |
4369 | static ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
4370 | size_t count, loff_t *ppos) |
4371 | { |
4372 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; |
4373 | int limit, batchcount, shared, res; |
4374 | struct kmem_cache *cachep; |
4375 | |
4376 | if (count > MAX_SLABINFO_WRITE) |
4377 | return -EINVAL; |
4378 | if (copy_from_user(&kbuf, buffer, count)) |
4379 | return -EFAULT; |
4380 | kbuf[MAX_SLABINFO_WRITE] = '\0'; |
4381 | |
4382 | tmp = strchr(kbuf, ' '); |
4383 | if (!tmp) |
4384 | return -EINVAL; |
4385 | *tmp = '\0'; |
4386 | tmp++; |
4387 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
4388 | return -EINVAL; |
4389 | |
4390 | /* Find the cache in the chain of caches. */ |
4391 | mutex_lock(&cache_chain_mutex); |
4392 | res = -EINVAL; |
4393 | list_for_each_entry(cachep, &cache_chain, next) { |
4394 | if (!strcmp(cachep->name, kbuf)) { |
4395 | if (limit < 1 || batchcount < 1 || |
4396 | batchcount > limit || shared < 0) { |
4397 | res = 0; |
4398 | } else { |
4399 | res = do_tune_cpucache(cachep, limit, |
4400 | batchcount, shared, |
4401 | GFP_KERNEL); |
4402 | } |
4403 | break; |
4404 | } |
4405 | } |
4406 | mutex_unlock(&cache_chain_mutex); |
4407 | if (res >= 0) |
4408 | res = count; |
4409 | return res; |
4410 | } |
4411 | |
4412 | static int slabinfo_open(struct inode *inode, struct file *file) |
4413 | { |
4414 | return seq_open(file, &slabinfo_op); |
4415 | } |
4416 | |
4417 | static const struct file_operations proc_slabinfo_operations = { |
4418 | .open = slabinfo_open, |
4419 | .read = seq_read, |
4420 | .write = slabinfo_write, |
4421 | .llseek = seq_lseek, |
4422 | .release = seq_release, |
4423 | }; |
4424 | |
4425 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4426 | |
4427 | static void *leaks_start(struct seq_file *m, loff_t *pos) |
4428 | { |
4429 | mutex_lock(&cache_chain_mutex); |
4430 | return seq_list_start(&cache_chain, *pos); |
4431 | } |
4432 | |
4433 | static inline int add_caller(unsigned long *n, unsigned long v) |
4434 | { |
4435 | unsigned long *p; |
4436 | int l; |
4437 | if (!v) |
4438 | return 1; |
4439 | l = n[1]; |
4440 | p = n + 2; |
4441 | while (l) { |
4442 | int i = l/2; |
4443 | unsigned long *q = p + 2 * i; |
4444 | if (*q == v) { |
4445 | q[1]++; |
4446 | return 1; |
4447 | } |
4448 | if (*q > v) { |
4449 | l = i; |
4450 | } else { |
4451 | p = q + 2; |
4452 | l -= i + 1; |
4453 | } |
4454 | } |
4455 | if (++n[1] == n[0]) |
4456 | return 0; |
4457 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); |
4458 | p[0] = v; |
4459 | p[1] = 1; |
4460 | return 1; |
4461 | } |
4462 | |
4463 | static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s) |
4464 | { |
4465 | void *p; |
4466 | int i; |
4467 | if (n[0] == n[1]) |
4468 | return; |
4469 | for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) { |
4470 | if (slab_bufctl(s)[i] != BUFCTL_ACTIVE) |
4471 | continue; |
4472 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) |
4473 | return; |
4474 | } |
4475 | } |
4476 | |
4477 | static void show_symbol(struct seq_file *m, unsigned long address) |
4478 | { |
4479 | #ifdef CONFIG_KALLSYMS |
4480 | unsigned long offset, size; |
4481 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; |
4482 | |
4483 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { |
4484 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); |
4485 | if (modname[0]) |
4486 | seq_printf(m, " [%s]", modname); |
4487 | return; |
4488 | } |
4489 | #endif |
4490 | seq_printf(m, "%p", (void *)address); |
4491 | } |
4492 | |
4493 | static int leaks_show(struct seq_file *m, void *p) |
4494 | { |
4495 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next); |
4496 | struct slab *slabp; |
4497 | struct kmem_list3 *l3; |
4498 | const char *name; |
4499 | unsigned long *n = m->private; |
4500 | int node; |
4501 | int i; |
4502 | |
4503 | if (!(cachep->flags & SLAB_STORE_USER)) |
4504 | return 0; |
4505 | if (!(cachep->flags & SLAB_RED_ZONE)) |
4506 | return 0; |
4507 | |
4508 | /* OK, we can do it */ |
4509 | |
4510 | n[1] = 0; |
4511 | |
4512 | for_each_online_node(node) { |
4513 | l3 = cachep->nodelists[node]; |
4514 | if (!l3) |
4515 | continue; |
4516 | |
4517 | check_irq_on(); |
4518 | spin_lock_irq(&l3->list_lock); |
4519 | |
4520 | list_for_each_entry(slabp, &l3->slabs_full, list) |
4521 | handle_slab(n, cachep, slabp); |
4522 | list_for_each_entry(slabp, &l3->slabs_partial, list) |
4523 | handle_slab(n, cachep, slabp); |
4524 | spin_unlock_irq(&l3->list_lock); |
4525 | } |
4526 | name = cachep->name; |
4527 | if (n[0] == n[1]) { |
4528 | /* Increase the buffer size */ |
4529 | mutex_unlock(&cache_chain_mutex); |
4530 | m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL); |
4531 | if (!m->private) { |
4532 | /* Too bad, we are really out */ |
4533 | m->private = n; |
4534 | mutex_lock(&cache_chain_mutex); |
4535 | return -ENOMEM; |
4536 | } |
4537 | *(unsigned long *)m->private = n[0] * 2; |
4538 | kfree(n); |
4539 | mutex_lock(&cache_chain_mutex); |
4540 | /* Now make sure this entry will be retried */ |
4541 | m->count = m->size; |
4542 | return 0; |
4543 | } |
4544 | for (i = 0; i < n[1]; i++) { |
4545 | seq_printf(m, "%s: %lu ", name, n[2*i+3]); |
4546 | show_symbol(m, n[2*i+2]); |
4547 | seq_putc(m, '\n'); |
4548 | } |
4549 | |
4550 | return 0; |
4551 | } |
4552 | |
4553 | static const struct seq_operations slabstats_op = { |
4554 | .start = leaks_start, |
4555 | .next = s_next, |
4556 | .stop = s_stop, |
4557 | .show = leaks_show, |
4558 | }; |
4559 | |
4560 | static int slabstats_open(struct inode *inode, struct file *file) |
4561 | { |
4562 | unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); |
4563 | int ret = -ENOMEM; |
4564 | if (n) { |
4565 | ret = seq_open(file, &slabstats_op); |
4566 | if (!ret) { |
4567 | struct seq_file *m = file->private_data; |
4568 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); |
4569 | m->private = n; |
4570 | n = NULL; |
4571 | } |
4572 | kfree(n); |
4573 | } |
4574 | return ret; |
4575 | } |
4576 | |
4577 | static const struct file_operations proc_slabstats_operations = { |
4578 | .open = slabstats_open, |
4579 | .read = seq_read, |
4580 | .llseek = seq_lseek, |
4581 | .release = seq_release_private, |
4582 | }; |
4583 | #endif |
4584 | |
4585 | static int __init slab_proc_init(void) |
4586 | { |
4587 | proc_create("slabinfo",S_IWUSR|S_IRUGO,NULL,&proc_slabinfo_operations); |
4588 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4589 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); |
4590 | #endif |
4591 | return 0; |
4592 | } |
4593 | module_init(slab_proc_init); |
4594 | #endif |
4595 | |
4596 | /** |
4597 | * ksize - get the actual amount of memory allocated for a given object |
4598 | * @objp: Pointer to the object |
4599 | * |
4600 | * kmalloc may internally round up allocations and return more memory |
4601 | * than requested. ksize() can be used to determine the actual amount of |
4602 | * memory allocated. The caller may use this additional memory, even though |
4603 | * a smaller amount of memory was initially specified with the kmalloc call. |
4604 | * The caller must guarantee that objp points to a valid object previously |
4605 | * allocated with either kmalloc() or kmem_cache_alloc(). The object |
4606 | * must not be freed during the duration of the call. |
4607 | */ |
4608 | size_t ksize(const void *objp) |
4609 | { |
4610 | BUG_ON(!objp); |
4611 | if (unlikely(objp == ZERO_SIZE_PTR)) |
4612 | return 0; |
4613 | |
4614 | return obj_size(virt_to_cache(objp)); |
4615 | } |
4616 | EXPORT_SYMBOL(ksize); |
4617 |
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