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