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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 83345 byte(s)
Tag kernel26-2.6.12-alx-r9
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 intializations 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 kmem_cache_t 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 semaphore 'cache_chain_sem'. |
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 | */ |
79 | |
80 | #include <linux/config.h> |
81 | #include <linux/slab.h> |
82 | #include <linux/mm.h> |
83 | #include <linux/swap.h> |
84 | #include <linux/cache.h> |
85 | #include <linux/interrupt.h> |
86 | #include <linux/init.h> |
87 | #include <linux/compiler.h> |
88 | #include <linux/seq_file.h> |
89 | #include <linux/notifier.h> |
90 | #include <linux/kallsyms.h> |
91 | #include <linux/cpu.h> |
92 | #include <linux/sysctl.h> |
93 | #include <linux/module.h> |
94 | #include <linux/rcupdate.h> |
95 | |
96 | #include <asm/uaccess.h> |
97 | #include <asm/cacheflush.h> |
98 | #include <asm/tlbflush.h> |
99 | #include <asm/page.h> |
100 | |
101 | /* |
102 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL, |
103 | * SLAB_RED_ZONE & SLAB_POISON. |
104 | * 0 for faster, smaller code (especially in the critical paths). |
105 | * |
106 | * STATS - 1 to collect stats for /proc/slabinfo. |
107 | * 0 for faster, smaller code (especially in the critical paths). |
108 | * |
109 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) |
110 | */ |
111 | |
112 | #ifdef CONFIG_DEBUG_SLAB |
113 | #define DEBUG 1 |
114 | #define STATS 1 |
115 | #define FORCED_DEBUG 1 |
116 | #else |
117 | #define DEBUG 0 |
118 | #define STATS 0 |
119 | #define FORCED_DEBUG 0 |
120 | #endif |
121 | |
122 | |
123 | /* Shouldn't this be in a header file somewhere? */ |
124 | #define BYTES_PER_WORD sizeof(void *) |
125 | |
126 | #ifndef cache_line_size |
127 | #define cache_line_size() L1_CACHE_BYTES |
128 | #endif |
129 | |
130 | #ifndef ARCH_KMALLOC_MINALIGN |
131 | /* |
132 | * Enforce a minimum alignment for the kmalloc caches. |
133 | * Usually, the kmalloc caches are cache_line_size() aligned, except when |
134 | * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned. |
135 | * Some archs want to perform DMA into kmalloc caches and need a guaranteed |
136 | * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that. |
137 | * Note that this flag disables some debug features. |
138 | */ |
139 | #define ARCH_KMALLOC_MINALIGN 0 |
140 | #endif |
141 | |
142 | #ifndef ARCH_SLAB_MINALIGN |
143 | /* |
144 | * Enforce a minimum alignment for all caches. |
145 | * Intended for archs that get misalignment faults even for BYTES_PER_WORD |
146 | * aligned buffers. Includes ARCH_KMALLOC_MINALIGN. |
147 | * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables |
148 | * some debug features. |
149 | */ |
150 | #define ARCH_SLAB_MINALIGN 0 |
151 | #endif |
152 | |
153 | #ifndef ARCH_KMALLOC_FLAGS |
154 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN |
155 | #endif |
156 | |
157 | /* Legal flag mask for kmem_cache_create(). */ |
158 | #if DEBUG |
159 | # define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \ |
160 | SLAB_POISON | SLAB_HWCACHE_ALIGN | \ |
161 | SLAB_NO_REAP | SLAB_CACHE_DMA | \ |
162 | SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \ |
163 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
164 | SLAB_DESTROY_BY_RCU) |
165 | #else |
166 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | SLAB_NO_REAP | \ |
167 | SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \ |
168 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
169 | SLAB_DESTROY_BY_RCU) |
170 | #endif |
171 | |
172 | /* |
173 | * kmem_bufctl_t: |
174 | * |
175 | * Bufctl's are used for linking objs within a slab |
176 | * linked offsets. |
177 | * |
178 | * This implementation relies on "struct page" for locating the cache & |
179 | * slab an object belongs to. |
180 | * This allows the bufctl structure to be small (one int), but limits |
181 | * the number of objects a slab (not a cache) can contain when off-slab |
182 | * bufctls are used. The limit is the size of the largest general cache |
183 | * that does not use off-slab slabs. |
184 | * For 32bit archs with 4 kB pages, is this 56. |
185 | * This is not serious, as it is only for large objects, when it is unwise |
186 | * to have too many per slab. |
187 | * Note: This limit can be raised by introducing a general cache whose size |
188 | * is less than 512 (PAGE_SIZE<<3), but greater than 256. |
189 | */ |
190 | |
191 | #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) |
192 | #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) |
193 | #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2) |
194 | |
195 | /* Max number of objs-per-slab for caches which use off-slab slabs. |
196 | * Needed to avoid a possible looping condition in cache_grow(). |
197 | */ |
198 | static unsigned long offslab_limit; |
199 | |
200 | /* |
201 | * struct slab |
202 | * |
203 | * Manages the objs in a slab. Placed either at the beginning of mem allocated |
204 | * for a slab, or allocated from an general cache. |
205 | * Slabs are chained into three list: fully used, partial, fully free slabs. |
206 | */ |
207 | struct slab { |
208 | struct list_head list; |
209 | unsigned long colouroff; |
210 | void *s_mem; /* including colour offset */ |
211 | unsigned int inuse; /* num of objs active in slab */ |
212 | kmem_bufctl_t free; |
213 | }; |
214 | |
215 | /* |
216 | * struct slab_rcu |
217 | * |
218 | * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to |
219 | * arrange for kmem_freepages to be called via RCU. This is useful if |
220 | * we need to approach a kernel structure obliquely, from its address |
221 | * obtained without the usual locking. We can lock the structure to |
222 | * stabilize it and check it's still at the given address, only if we |
223 | * can be sure that the memory has not been meanwhile reused for some |
224 | * other kind of object (which our subsystem's lock might corrupt). |
225 | * |
226 | * rcu_read_lock before reading the address, then rcu_read_unlock after |
227 | * taking the spinlock within the structure expected at that address. |
228 | * |
229 | * We assume struct slab_rcu can overlay struct slab when destroying. |
230 | */ |
231 | struct slab_rcu { |
232 | struct rcu_head head; |
233 | kmem_cache_t *cachep; |
234 | void *addr; |
235 | }; |
236 | |
237 | /* |
238 | * struct array_cache |
239 | * |
240 | * Per cpu structures |
241 | * Purpose: |
242 | * - LIFO ordering, to hand out cache-warm objects from _alloc |
243 | * - reduce the number of linked list operations |
244 | * - reduce spinlock operations |
245 | * |
246 | * The limit is stored in the per-cpu structure to reduce the data cache |
247 | * footprint. |
248 | * |
249 | */ |
250 | struct array_cache { |
251 | unsigned int avail; |
252 | unsigned int limit; |
253 | unsigned int batchcount; |
254 | unsigned int touched; |
255 | }; |
256 | |
257 | /* bootstrap: The caches do not work without cpuarrays anymore, |
258 | * but the cpuarrays are allocated from the generic caches... |
259 | */ |
260 | #define BOOT_CPUCACHE_ENTRIES 1 |
261 | struct arraycache_init { |
262 | struct array_cache cache; |
263 | void * entries[BOOT_CPUCACHE_ENTRIES]; |
264 | }; |
265 | |
266 | /* |
267 | * The slab lists of all objects. |
268 | * Hopefully reduce the internal fragmentation |
269 | * NUMA: The spinlock could be moved from the kmem_cache_t |
270 | * into this structure, too. Figure out what causes |
271 | * fewer cross-node spinlock operations. |
272 | */ |
273 | struct kmem_list3 { |
274 | struct list_head slabs_partial; /* partial list first, better asm code */ |
275 | struct list_head slabs_full; |
276 | struct list_head slabs_free; |
277 | unsigned long free_objects; |
278 | int free_touched; |
279 | unsigned long next_reap; |
280 | struct array_cache *shared; |
281 | }; |
282 | |
283 | #define LIST3_INIT(parent) \ |
284 | { \ |
285 | .slabs_full = LIST_HEAD_INIT(parent.slabs_full), \ |
286 | .slabs_partial = LIST_HEAD_INIT(parent.slabs_partial), \ |
287 | .slabs_free = LIST_HEAD_INIT(parent.slabs_free) \ |
288 | } |
289 | #define list3_data(cachep) \ |
290 | (&(cachep)->lists) |
291 | |
292 | /* NUMA: per-node */ |
293 | #define list3_data_ptr(cachep, ptr) \ |
294 | list3_data(cachep) |
295 | |
296 | /* |
297 | * kmem_cache_t |
298 | * |
299 | * manages a cache. |
300 | */ |
301 | |
302 | struct kmem_cache_s { |
303 | /* 1) per-cpu data, touched during every alloc/free */ |
304 | struct array_cache *array[NR_CPUS]; |
305 | unsigned int batchcount; |
306 | unsigned int limit; |
307 | /* 2) touched by every alloc & free from the backend */ |
308 | struct kmem_list3 lists; |
309 | /* NUMA: kmem_3list_t *nodelists[MAX_NUMNODES] */ |
310 | unsigned int objsize; |
311 | unsigned int flags; /* constant flags */ |
312 | unsigned int num; /* # of objs per slab */ |
313 | unsigned int free_limit; /* upper limit of objects in the lists */ |
314 | spinlock_t spinlock; |
315 | |
316 | /* 3) cache_grow/shrink */ |
317 | /* order of pgs per slab (2^n) */ |
318 | unsigned int gfporder; |
319 | |
320 | /* force GFP flags, e.g. GFP_DMA */ |
321 | unsigned int gfpflags; |
322 | |
323 | size_t colour; /* cache colouring range */ |
324 | unsigned int colour_off; /* colour offset */ |
325 | unsigned int colour_next; /* cache colouring */ |
326 | kmem_cache_t *slabp_cache; |
327 | unsigned int slab_size; |
328 | unsigned int dflags; /* dynamic flags */ |
329 | |
330 | /* constructor func */ |
331 | void (*ctor)(void *, kmem_cache_t *, unsigned long); |
332 | |
333 | /* de-constructor func */ |
334 | void (*dtor)(void *, kmem_cache_t *, unsigned long); |
335 | |
336 | /* 4) cache creation/removal */ |
337 | const char *name; |
338 | struct list_head next; |
339 | |
340 | /* 5) statistics */ |
341 | #if STATS |
342 | unsigned long num_active; |
343 | unsigned long num_allocations; |
344 | unsigned long high_mark; |
345 | unsigned long grown; |
346 | unsigned long reaped; |
347 | unsigned long errors; |
348 | unsigned long max_freeable; |
349 | unsigned long node_allocs; |
350 | atomic_t allochit; |
351 | atomic_t allocmiss; |
352 | atomic_t freehit; |
353 | atomic_t freemiss; |
354 | #endif |
355 | #if DEBUG |
356 | int dbghead; |
357 | int reallen; |
358 | #endif |
359 | }; |
360 | |
361 | #define CFLGS_OFF_SLAB (0x80000000UL) |
362 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
363 | |
364 | #define BATCHREFILL_LIMIT 16 |
365 | /* Optimization question: fewer reaps means less |
366 | * probability for unnessary cpucache drain/refill cycles. |
367 | * |
368 | * OTHO the cpuarrays can contain lots of objects, |
369 | * which could lock up otherwise freeable slabs. |
370 | */ |
371 | #define REAPTIMEOUT_CPUC (2*HZ) |
372 | #define REAPTIMEOUT_LIST3 (4*HZ) |
373 | |
374 | #if STATS |
375 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
376 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
377 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
378 | #define STATS_INC_GROWN(x) ((x)->grown++) |
379 | #define STATS_INC_REAPED(x) ((x)->reaped++) |
380 | #define STATS_SET_HIGH(x) do { if ((x)->num_active > (x)->high_mark) \ |
381 | (x)->high_mark = (x)->num_active; \ |
382 | } while (0) |
383 | #define STATS_INC_ERR(x) ((x)->errors++) |
384 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
385 | #define STATS_SET_FREEABLE(x, i) \ |
386 | do { if ((x)->max_freeable < i) \ |
387 | (x)->max_freeable = i; \ |
388 | } while (0) |
389 | |
390 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
391 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
392 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
393 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
394 | #else |
395 | #define STATS_INC_ACTIVE(x) do { } while (0) |
396 | #define STATS_DEC_ACTIVE(x) do { } while (0) |
397 | #define STATS_INC_ALLOCED(x) do { } while (0) |
398 | #define STATS_INC_GROWN(x) do { } while (0) |
399 | #define STATS_INC_REAPED(x) do { } while (0) |
400 | #define STATS_SET_HIGH(x) do { } while (0) |
401 | #define STATS_INC_ERR(x) do { } while (0) |
402 | #define STATS_INC_NODEALLOCS(x) do { } while (0) |
403 | #define STATS_SET_FREEABLE(x, i) \ |
404 | do { } while (0) |
405 | |
406 | #define STATS_INC_ALLOCHIT(x) do { } while (0) |
407 | #define STATS_INC_ALLOCMISS(x) do { } while (0) |
408 | #define STATS_INC_FREEHIT(x) do { } while (0) |
409 | #define STATS_INC_FREEMISS(x) do { } while (0) |
410 | #endif |
411 | |
412 | #if DEBUG |
413 | /* Magic nums for obj red zoning. |
414 | * Placed in the first word before and the first word after an obj. |
415 | */ |
416 | #define RED_INACTIVE 0x5A2CF071UL /* when obj is inactive */ |
417 | #define RED_ACTIVE 0x170FC2A5UL /* when obj is active */ |
418 | |
419 | /* ...and for poisoning */ |
420 | #define POISON_INUSE 0x5a /* for use-uninitialised poisoning */ |
421 | #define POISON_FREE 0x6b /* for use-after-free poisoning */ |
422 | #define POISON_END 0xa5 /* end-byte of poisoning */ |
423 | |
424 | /* memory layout of objects: |
425 | * 0 : objp |
426 | * 0 .. cachep->dbghead - BYTES_PER_WORD - 1: padding. This ensures that |
427 | * the end of an object is aligned with the end of the real |
428 | * allocation. Catches writes behind the end of the allocation. |
429 | * cachep->dbghead - BYTES_PER_WORD .. cachep->dbghead - 1: |
430 | * redzone word. |
431 | * cachep->dbghead: The real object. |
432 | * cachep->objsize - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
433 | * cachep->objsize - 1* BYTES_PER_WORD: last caller address [BYTES_PER_WORD long] |
434 | */ |
435 | static int obj_dbghead(kmem_cache_t *cachep) |
436 | { |
437 | return cachep->dbghead; |
438 | } |
439 | |
440 | static int obj_reallen(kmem_cache_t *cachep) |
441 | { |
442 | return cachep->reallen; |
443 | } |
444 | |
445 | static unsigned long *dbg_redzone1(kmem_cache_t *cachep, void *objp) |
446 | { |
447 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
448 | return (unsigned long*) (objp+obj_dbghead(cachep)-BYTES_PER_WORD); |
449 | } |
450 | |
451 | static unsigned long *dbg_redzone2(kmem_cache_t *cachep, void *objp) |
452 | { |
453 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
454 | if (cachep->flags & SLAB_STORE_USER) |
455 | return (unsigned long*) (objp+cachep->objsize-2*BYTES_PER_WORD); |
456 | return (unsigned long*) (objp+cachep->objsize-BYTES_PER_WORD); |
457 | } |
458 | |
459 | static void **dbg_userword(kmem_cache_t *cachep, void *objp) |
460 | { |
461 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
462 | return (void**)(objp+cachep->objsize-BYTES_PER_WORD); |
463 | } |
464 | |
465 | #else |
466 | |
467 | #define obj_dbghead(x) 0 |
468 | #define obj_reallen(cachep) (cachep->objsize) |
469 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;}) |
470 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;}) |
471 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
472 | |
473 | #endif |
474 | |
475 | /* |
476 | * Maximum size of an obj (in 2^order pages) |
477 | * and absolute limit for the gfp order. |
478 | */ |
479 | #if defined(CONFIG_LARGE_ALLOCS) |
480 | #define MAX_OBJ_ORDER 13 /* up to 32Mb */ |
481 | #define MAX_GFP_ORDER 13 /* up to 32Mb */ |
482 | #elif defined(CONFIG_MMU) |
483 | #define MAX_OBJ_ORDER 5 /* 32 pages */ |
484 | #define MAX_GFP_ORDER 5 /* 32 pages */ |
485 | #else |
486 | #define MAX_OBJ_ORDER 8 /* up to 1Mb */ |
487 | #define MAX_GFP_ORDER 8 /* up to 1Mb */ |
488 | #endif |
489 | |
490 | /* |
491 | * Do not go above this order unless 0 objects fit into the slab. |
492 | */ |
493 | #define BREAK_GFP_ORDER_HI 1 |
494 | #define BREAK_GFP_ORDER_LO 0 |
495 | static int slab_break_gfp_order = BREAK_GFP_ORDER_LO; |
496 | |
497 | /* Macros for storing/retrieving the cachep and or slab from the |
498 | * global 'mem_map'. These are used to find the slab an obj belongs to. |
499 | * With kfree(), these are used to find the cache which an obj belongs to. |
500 | */ |
501 | #define SET_PAGE_CACHE(pg,x) ((pg)->lru.next = (struct list_head *)(x)) |
502 | #define GET_PAGE_CACHE(pg) ((kmem_cache_t *)(pg)->lru.next) |
503 | #define SET_PAGE_SLAB(pg,x) ((pg)->lru.prev = (struct list_head *)(x)) |
504 | #define GET_PAGE_SLAB(pg) ((struct slab *)(pg)->lru.prev) |
505 | |
506 | /* These are the default caches for kmalloc. Custom caches can have other sizes. */ |
507 | struct cache_sizes malloc_sizes[] = { |
508 | #define CACHE(x) { .cs_size = (x) }, |
509 | #include <linux/kmalloc_sizes.h> |
510 | CACHE(ULONG_MAX) |
511 | #undef CACHE |
512 | }; |
513 | EXPORT_SYMBOL(malloc_sizes); |
514 | |
515 | /* Must match cache_sizes above. Out of line to keep cache footprint low. */ |
516 | struct cache_names { |
517 | char *name; |
518 | char *name_dma; |
519 | }; |
520 | |
521 | static struct cache_names __initdata cache_names[] = { |
522 | #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" }, |
523 | #include <linux/kmalloc_sizes.h> |
524 | { NULL, } |
525 | #undef CACHE |
526 | }; |
527 | |
528 | static struct arraycache_init initarray_cache __initdata = |
529 | { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
530 | static struct arraycache_init initarray_generic = |
531 | { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; |
532 | |
533 | /* internal cache of cache description objs */ |
534 | static kmem_cache_t cache_cache = { |
535 | .lists = LIST3_INIT(cache_cache.lists), |
536 | .batchcount = 1, |
537 | .limit = BOOT_CPUCACHE_ENTRIES, |
538 | .objsize = sizeof(kmem_cache_t), |
539 | .flags = SLAB_NO_REAP, |
540 | .spinlock = SPIN_LOCK_UNLOCKED, |
541 | .name = "kmem_cache", |
542 | #if DEBUG |
543 | .reallen = sizeof(kmem_cache_t), |
544 | #endif |
545 | }; |
546 | |
547 | /* Guard access to the cache-chain. */ |
548 | static struct semaphore cache_chain_sem; |
549 | static struct list_head cache_chain; |
550 | |
551 | /* |
552 | * vm_enough_memory() looks at this to determine how many |
553 | * slab-allocated pages are possibly freeable under pressure |
554 | * |
555 | * SLAB_RECLAIM_ACCOUNT turns this on per-slab |
556 | */ |
557 | atomic_t slab_reclaim_pages; |
558 | EXPORT_SYMBOL(slab_reclaim_pages); |
559 | |
560 | /* |
561 | * chicken and egg problem: delay the per-cpu array allocation |
562 | * until the general caches are up. |
563 | */ |
564 | static enum { |
565 | NONE, |
566 | PARTIAL, |
567 | FULL |
568 | } g_cpucache_up; |
569 | |
570 | static DEFINE_PER_CPU(struct work_struct, reap_work); |
571 | |
572 | static void free_block(kmem_cache_t* cachep, void** objpp, int len); |
573 | static void enable_cpucache (kmem_cache_t *cachep); |
574 | static void cache_reap (void *unused); |
575 | |
576 | static inline void **ac_entry(struct array_cache *ac) |
577 | { |
578 | return (void**)(ac+1); |
579 | } |
580 | |
581 | static inline struct array_cache *ac_data(kmem_cache_t *cachep) |
582 | { |
583 | return cachep->array[smp_processor_id()]; |
584 | } |
585 | |
586 | static inline kmem_cache_t *__find_general_cachep(size_t size, int gfpflags) |
587 | { |
588 | struct cache_sizes *csizep = malloc_sizes; |
589 | |
590 | #if DEBUG |
591 | /* This happens if someone tries to call |
592 | * kmem_cache_create(), or __kmalloc(), before |
593 | * the generic caches are initialized. |
594 | */ |
595 | BUG_ON(csizep->cs_cachep == NULL); |
596 | #endif |
597 | while (size > csizep->cs_size) |
598 | csizep++; |
599 | |
600 | /* |
601 | * Really subtile: The last entry with cs->cs_size==ULONG_MAX |
602 | * has cs_{dma,}cachep==NULL. Thus no special case |
603 | * for large kmalloc calls required. |
604 | */ |
605 | if (unlikely(gfpflags & GFP_DMA)) |
606 | return csizep->cs_dmacachep; |
607 | return csizep->cs_cachep; |
608 | } |
609 | |
610 | kmem_cache_t *kmem_find_general_cachep(size_t size, int gfpflags) |
611 | { |
612 | return __find_general_cachep(size, gfpflags); |
613 | } |
614 | EXPORT_SYMBOL(kmem_find_general_cachep); |
615 | |
616 | /* Cal the num objs, wastage, and bytes left over for a given slab size. */ |
617 | static void cache_estimate(unsigned long gfporder, size_t size, size_t align, |
618 | int flags, size_t *left_over, unsigned int *num) |
619 | { |
620 | int i; |
621 | size_t wastage = PAGE_SIZE<<gfporder; |
622 | size_t extra = 0; |
623 | size_t base = 0; |
624 | |
625 | if (!(flags & CFLGS_OFF_SLAB)) { |
626 | base = sizeof(struct slab); |
627 | extra = sizeof(kmem_bufctl_t); |
628 | } |
629 | i = 0; |
630 | while (i*size + ALIGN(base+i*extra, align) <= wastage) |
631 | i++; |
632 | if (i > 0) |
633 | i--; |
634 | |
635 | if (i > SLAB_LIMIT) |
636 | i = SLAB_LIMIT; |
637 | |
638 | *num = i; |
639 | wastage -= i*size; |
640 | wastage -= ALIGN(base+i*extra, align); |
641 | *left_over = wastage; |
642 | } |
643 | |
644 | #define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg) |
645 | |
646 | static void __slab_error(const char *function, kmem_cache_t *cachep, char *msg) |
647 | { |
648 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", |
649 | function, cachep->name, msg); |
650 | dump_stack(); |
651 | } |
652 | |
653 | /* |
654 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
655 | * via the workqueue/eventd. |
656 | * Add the CPU number into the expiration time to minimize the possibility of |
657 | * the CPUs getting into lockstep and contending for the global cache chain |
658 | * lock. |
659 | */ |
660 | static void __devinit start_cpu_timer(int cpu) |
661 | { |
662 | struct work_struct *reap_work = &per_cpu(reap_work, cpu); |
663 | |
664 | /* |
665 | * When this gets called from do_initcalls via cpucache_init(), |
666 | * init_workqueues() has already run, so keventd will be setup |
667 | * at that time. |
668 | */ |
669 | if (keventd_up() && reap_work->func == NULL) { |
670 | INIT_WORK(reap_work, cache_reap, NULL); |
671 | schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu); |
672 | } |
673 | } |
674 | |
675 | static struct array_cache *alloc_arraycache(int cpu, int entries, |
676 | int batchcount) |
677 | { |
678 | int memsize = sizeof(void*)*entries+sizeof(struct array_cache); |
679 | struct array_cache *nc = NULL; |
680 | |
681 | if (cpu == -1) |
682 | nc = kmalloc(memsize, GFP_KERNEL); |
683 | else |
684 | nc = kmalloc_node(memsize, GFP_KERNEL, cpu_to_node(cpu)); |
685 | |
686 | if (nc) { |
687 | nc->avail = 0; |
688 | nc->limit = entries; |
689 | nc->batchcount = batchcount; |
690 | nc->touched = 0; |
691 | } |
692 | return nc; |
693 | } |
694 | |
695 | static int __devinit cpuup_callback(struct notifier_block *nfb, |
696 | unsigned long action, void *hcpu) |
697 | { |
698 | long cpu = (long)hcpu; |
699 | kmem_cache_t* cachep; |
700 | |
701 | switch (action) { |
702 | case CPU_UP_PREPARE: |
703 | down(&cache_chain_sem); |
704 | list_for_each_entry(cachep, &cache_chain, next) { |
705 | struct array_cache *nc; |
706 | |
707 | nc = alloc_arraycache(cpu, cachep->limit, cachep->batchcount); |
708 | if (!nc) |
709 | goto bad; |
710 | |
711 | spin_lock_irq(&cachep->spinlock); |
712 | cachep->array[cpu] = nc; |
713 | cachep->free_limit = (1+num_online_cpus())*cachep->batchcount |
714 | + cachep->num; |
715 | spin_unlock_irq(&cachep->spinlock); |
716 | |
717 | } |
718 | up(&cache_chain_sem); |
719 | break; |
720 | case CPU_ONLINE: |
721 | start_cpu_timer(cpu); |
722 | break; |
723 | #ifdef CONFIG_HOTPLUG_CPU |
724 | case CPU_DEAD: |
725 | /* fall thru */ |
726 | case CPU_UP_CANCELED: |
727 | down(&cache_chain_sem); |
728 | |
729 | list_for_each_entry(cachep, &cache_chain, next) { |
730 | struct array_cache *nc; |
731 | |
732 | spin_lock_irq(&cachep->spinlock); |
733 | /* cpu is dead; no one can alloc from it. */ |
734 | nc = cachep->array[cpu]; |
735 | cachep->array[cpu] = NULL; |
736 | cachep->free_limit -= cachep->batchcount; |
737 | free_block(cachep, ac_entry(nc), nc->avail); |
738 | spin_unlock_irq(&cachep->spinlock); |
739 | kfree(nc); |
740 | } |
741 | up(&cache_chain_sem); |
742 | break; |
743 | #endif |
744 | } |
745 | return NOTIFY_OK; |
746 | bad: |
747 | up(&cache_chain_sem); |
748 | return NOTIFY_BAD; |
749 | } |
750 | |
751 | static struct notifier_block cpucache_notifier = { &cpuup_callback, NULL, 0 }; |
752 | |
753 | /* Initialisation. |
754 | * Called after the gfp() functions have been enabled, and before smp_init(). |
755 | */ |
756 | void __init kmem_cache_init(void) |
757 | { |
758 | size_t left_over; |
759 | struct cache_sizes *sizes; |
760 | struct cache_names *names; |
761 | |
762 | /* |
763 | * Fragmentation resistance on low memory - only use bigger |
764 | * page orders on machines with more than 32MB of memory. |
765 | */ |
766 | if (num_physpages > (32 << 20) >> PAGE_SHIFT) |
767 | slab_break_gfp_order = BREAK_GFP_ORDER_HI; |
768 | |
769 | |
770 | /* Bootstrap is tricky, because several objects are allocated |
771 | * from caches that do not exist yet: |
772 | * 1) initialize the cache_cache cache: it contains the kmem_cache_t |
773 | * structures of all caches, except cache_cache itself: cache_cache |
774 | * is statically allocated. |
775 | * Initially an __init data area is used for the head array, it's |
776 | * replaced with a kmalloc allocated array at the end of the bootstrap. |
777 | * 2) Create the first kmalloc cache. |
778 | * The kmem_cache_t for the new cache is allocated normally. An __init |
779 | * data area is used for the head array. |
780 | * 3) Create the remaining kmalloc caches, with minimally sized head arrays. |
781 | * 4) Replace the __init data head arrays for cache_cache and the first |
782 | * kmalloc cache with kmalloc allocated arrays. |
783 | * 5) Resize the head arrays of the kmalloc caches to their final sizes. |
784 | */ |
785 | |
786 | /* 1) create the cache_cache */ |
787 | init_MUTEX(&cache_chain_sem); |
788 | INIT_LIST_HEAD(&cache_chain); |
789 | list_add(&cache_cache.next, &cache_chain); |
790 | cache_cache.colour_off = cache_line_size(); |
791 | cache_cache.array[smp_processor_id()] = &initarray_cache.cache; |
792 | |
793 | cache_cache.objsize = ALIGN(cache_cache.objsize, cache_line_size()); |
794 | |
795 | cache_estimate(0, cache_cache.objsize, cache_line_size(), 0, |
796 | &left_over, &cache_cache.num); |
797 | if (!cache_cache.num) |
798 | BUG(); |
799 | |
800 | cache_cache.colour = left_over/cache_cache.colour_off; |
801 | cache_cache.colour_next = 0; |
802 | cache_cache.slab_size = ALIGN(cache_cache.num*sizeof(kmem_bufctl_t) + |
803 | sizeof(struct slab), cache_line_size()); |
804 | |
805 | /* 2+3) create the kmalloc caches */ |
806 | sizes = malloc_sizes; |
807 | names = cache_names; |
808 | |
809 | while (sizes->cs_size != ULONG_MAX) { |
810 | /* For performance, all the general caches are L1 aligned. |
811 | * This should be particularly beneficial on SMP boxes, as it |
812 | * eliminates "false sharing". |
813 | * Note for systems short on memory removing the alignment will |
814 | * allow tighter packing of the smaller caches. */ |
815 | sizes->cs_cachep = kmem_cache_create(names->name, |
816 | sizes->cs_size, ARCH_KMALLOC_MINALIGN, |
817 | (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL); |
818 | |
819 | /* Inc off-slab bufctl limit until the ceiling is hit. */ |
820 | if (!(OFF_SLAB(sizes->cs_cachep))) { |
821 | offslab_limit = sizes->cs_size-sizeof(struct slab); |
822 | offslab_limit /= sizeof(kmem_bufctl_t); |
823 | } |
824 | |
825 | sizes->cs_dmacachep = kmem_cache_create(names->name_dma, |
826 | sizes->cs_size, ARCH_KMALLOC_MINALIGN, |
827 | (ARCH_KMALLOC_FLAGS | SLAB_CACHE_DMA | SLAB_PANIC), |
828 | NULL, NULL); |
829 | |
830 | sizes++; |
831 | names++; |
832 | } |
833 | /* 4) Replace the bootstrap head arrays */ |
834 | { |
835 | void * ptr; |
836 | |
837 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); |
838 | local_irq_disable(); |
839 | BUG_ON(ac_data(&cache_cache) != &initarray_cache.cache); |
840 | memcpy(ptr, ac_data(&cache_cache), sizeof(struct arraycache_init)); |
841 | cache_cache.array[smp_processor_id()] = ptr; |
842 | local_irq_enable(); |
843 | |
844 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); |
845 | local_irq_disable(); |
846 | BUG_ON(ac_data(malloc_sizes[0].cs_cachep) != &initarray_generic.cache); |
847 | memcpy(ptr, ac_data(malloc_sizes[0].cs_cachep), |
848 | sizeof(struct arraycache_init)); |
849 | malloc_sizes[0].cs_cachep->array[smp_processor_id()] = ptr; |
850 | local_irq_enable(); |
851 | } |
852 | |
853 | /* 5) resize the head arrays to their final sizes */ |
854 | { |
855 | kmem_cache_t *cachep; |
856 | down(&cache_chain_sem); |
857 | list_for_each_entry(cachep, &cache_chain, next) |
858 | enable_cpucache(cachep); |
859 | up(&cache_chain_sem); |
860 | } |
861 | |
862 | /* Done! */ |
863 | g_cpucache_up = FULL; |
864 | |
865 | /* Register a cpu startup notifier callback |
866 | * that initializes ac_data for all new cpus |
867 | */ |
868 | register_cpu_notifier(&cpucache_notifier); |
869 | |
870 | |
871 | /* The reap timers are started later, with a module init call: |
872 | * That part of the kernel is not yet operational. |
873 | */ |
874 | } |
875 | |
876 | static int __init cpucache_init(void) |
877 | { |
878 | int cpu; |
879 | |
880 | /* |
881 | * Register the timers that return unneeded |
882 | * pages to gfp. |
883 | */ |
884 | for (cpu = 0; cpu < NR_CPUS; cpu++) { |
885 | if (cpu_online(cpu)) |
886 | start_cpu_timer(cpu); |
887 | } |
888 | |
889 | return 0; |
890 | } |
891 | |
892 | __initcall(cpucache_init); |
893 | |
894 | /* |
895 | * Interface to system's page allocator. No need to hold the cache-lock. |
896 | * |
897 | * If we requested dmaable memory, we will get it. Even if we |
898 | * did not request dmaable memory, we might get it, but that |
899 | * would be relatively rare and ignorable. |
900 | */ |
901 | static void *kmem_getpages(kmem_cache_t *cachep, unsigned int __nocast flags, int nodeid) |
902 | { |
903 | struct page *page; |
904 | void *addr; |
905 | int i; |
906 | |
907 | flags |= cachep->gfpflags; |
908 | if (likely(nodeid == -1)) { |
909 | page = alloc_pages(flags, cachep->gfporder); |
910 | } else { |
911 | page = alloc_pages_node(nodeid, flags, cachep->gfporder); |
912 | } |
913 | if (!page) |
914 | return NULL; |
915 | addr = page_address(page); |
916 | |
917 | i = (1 << cachep->gfporder); |
918 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
919 | atomic_add(i, &slab_reclaim_pages); |
920 | add_page_state(nr_slab, i); |
921 | while (i--) { |
922 | SetPageSlab(page); |
923 | page++; |
924 | } |
925 | return addr; |
926 | } |
927 | |
928 | /* |
929 | * Interface to system's page release. |
930 | */ |
931 | static void kmem_freepages(kmem_cache_t *cachep, void *addr) |
932 | { |
933 | unsigned long i = (1<<cachep->gfporder); |
934 | struct page *page = virt_to_page(addr); |
935 | const unsigned long nr_freed = i; |
936 | |
937 | while (i--) { |
938 | if (!TestClearPageSlab(page)) |
939 | BUG(); |
940 | page++; |
941 | } |
942 | sub_page_state(nr_slab, nr_freed); |
943 | if (current->reclaim_state) |
944 | current->reclaim_state->reclaimed_slab += nr_freed; |
945 | free_pages((unsigned long)addr, cachep->gfporder); |
946 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
947 | atomic_sub(1<<cachep->gfporder, &slab_reclaim_pages); |
948 | } |
949 | |
950 | static void kmem_rcu_free(struct rcu_head *head) |
951 | { |
952 | struct slab_rcu *slab_rcu = (struct slab_rcu *) head; |
953 | kmem_cache_t *cachep = slab_rcu->cachep; |
954 | |
955 | kmem_freepages(cachep, slab_rcu->addr); |
956 | if (OFF_SLAB(cachep)) |
957 | kmem_cache_free(cachep->slabp_cache, slab_rcu); |
958 | } |
959 | |
960 | #if DEBUG |
961 | |
962 | #ifdef CONFIG_DEBUG_PAGEALLOC |
963 | static void store_stackinfo(kmem_cache_t *cachep, unsigned long *addr, |
964 | unsigned long caller) |
965 | { |
966 | int size = obj_reallen(cachep); |
967 | |
968 | addr = (unsigned long *)&((char*)addr)[obj_dbghead(cachep)]; |
969 | |
970 | if (size < 5*sizeof(unsigned long)) |
971 | return; |
972 | |
973 | *addr++=0x12345678; |
974 | *addr++=caller; |
975 | *addr++=smp_processor_id(); |
976 | size -= 3*sizeof(unsigned long); |
977 | { |
978 | unsigned long *sptr = &caller; |
979 | unsigned long svalue; |
980 | |
981 | while (!kstack_end(sptr)) { |
982 | svalue = *sptr++; |
983 | if (kernel_text_address(svalue)) { |
984 | *addr++=svalue; |
985 | size -= sizeof(unsigned long); |
986 | if (size <= sizeof(unsigned long)) |
987 | break; |
988 | } |
989 | } |
990 | |
991 | } |
992 | *addr++=0x87654321; |
993 | } |
994 | #endif |
995 | |
996 | static void poison_obj(kmem_cache_t *cachep, void *addr, unsigned char val) |
997 | { |
998 | int size = obj_reallen(cachep); |
999 | addr = &((char*)addr)[obj_dbghead(cachep)]; |
1000 | |
1001 | memset(addr, val, size); |
1002 | *(unsigned char *)(addr+size-1) = POISON_END; |
1003 | } |
1004 | |
1005 | static void dump_line(char *data, int offset, int limit) |
1006 | { |
1007 | int i; |
1008 | printk(KERN_ERR "%03x:", offset); |
1009 | for (i=0;i<limit;i++) { |
1010 | printk(" %02x", (unsigned char)data[offset+i]); |
1011 | } |
1012 | printk("\n"); |
1013 | } |
1014 | #endif |
1015 | |
1016 | #if DEBUG |
1017 | |
1018 | static void print_objinfo(kmem_cache_t *cachep, void *objp, int lines) |
1019 | { |
1020 | int i, size; |
1021 | char *realobj; |
1022 | |
1023 | if (cachep->flags & SLAB_RED_ZONE) { |
1024 | printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n", |
1025 | *dbg_redzone1(cachep, objp), |
1026 | *dbg_redzone2(cachep, objp)); |
1027 | } |
1028 | |
1029 | if (cachep->flags & SLAB_STORE_USER) { |
1030 | printk(KERN_ERR "Last user: [<%p>]", |
1031 | *dbg_userword(cachep, objp)); |
1032 | print_symbol("(%s)", |
1033 | (unsigned long)*dbg_userword(cachep, objp)); |
1034 | printk("\n"); |
1035 | } |
1036 | realobj = (char*)objp+obj_dbghead(cachep); |
1037 | size = obj_reallen(cachep); |
1038 | for (i=0; i<size && lines;i+=16, lines--) { |
1039 | int limit; |
1040 | limit = 16; |
1041 | if (i+limit > size) |
1042 | limit = size-i; |
1043 | dump_line(realobj, i, limit); |
1044 | } |
1045 | } |
1046 | |
1047 | static void check_poison_obj(kmem_cache_t *cachep, void *objp) |
1048 | { |
1049 | char *realobj; |
1050 | int size, i; |
1051 | int lines = 0; |
1052 | |
1053 | realobj = (char*)objp+obj_dbghead(cachep); |
1054 | size = obj_reallen(cachep); |
1055 | |
1056 | for (i=0;i<size;i++) { |
1057 | char exp = POISON_FREE; |
1058 | if (i == size-1) |
1059 | exp = POISON_END; |
1060 | if (realobj[i] != exp) { |
1061 | int limit; |
1062 | /* Mismatch ! */ |
1063 | /* Print header */ |
1064 | if (lines == 0) { |
1065 | printk(KERN_ERR "Slab corruption: start=%p, len=%d\n", |
1066 | realobj, size); |
1067 | print_objinfo(cachep, objp, 0); |
1068 | } |
1069 | /* Hexdump the affected line */ |
1070 | i = (i/16)*16; |
1071 | limit = 16; |
1072 | if (i+limit > size) |
1073 | limit = size-i; |
1074 | dump_line(realobj, i, limit); |
1075 | i += 16; |
1076 | lines++; |
1077 | /* Limit to 5 lines */ |
1078 | if (lines > 5) |
1079 | break; |
1080 | } |
1081 | } |
1082 | if (lines != 0) { |
1083 | /* Print some data about the neighboring objects, if they |
1084 | * exist: |
1085 | */ |
1086 | struct slab *slabp = GET_PAGE_SLAB(virt_to_page(objp)); |
1087 | int objnr; |
1088 | |
1089 | objnr = (objp-slabp->s_mem)/cachep->objsize; |
1090 | if (objnr) { |
1091 | objp = slabp->s_mem+(objnr-1)*cachep->objsize; |
1092 | realobj = (char*)objp+obj_dbghead(cachep); |
1093 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", |
1094 | realobj, size); |
1095 | print_objinfo(cachep, objp, 2); |
1096 | } |
1097 | if (objnr+1 < cachep->num) { |
1098 | objp = slabp->s_mem+(objnr+1)*cachep->objsize; |
1099 | realobj = (char*)objp+obj_dbghead(cachep); |
1100 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", |
1101 | realobj, size); |
1102 | print_objinfo(cachep, objp, 2); |
1103 | } |
1104 | } |
1105 | } |
1106 | #endif |
1107 | |
1108 | /* Destroy all the objs in a slab, and release the mem back to the system. |
1109 | * Before calling the slab must have been unlinked from the cache. |
1110 | * The cache-lock is not held/needed. |
1111 | */ |
1112 | static void slab_destroy (kmem_cache_t *cachep, struct slab *slabp) |
1113 | { |
1114 | void *addr = slabp->s_mem - slabp->colouroff; |
1115 | |
1116 | #if DEBUG |
1117 | int i; |
1118 | for (i = 0; i < cachep->num; i++) { |
1119 | void *objp = slabp->s_mem + cachep->objsize * i; |
1120 | |
1121 | if (cachep->flags & SLAB_POISON) { |
1122 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1123 | if ((cachep->objsize%PAGE_SIZE)==0 && OFF_SLAB(cachep)) |
1124 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE,1); |
1125 | else |
1126 | check_poison_obj(cachep, objp); |
1127 | #else |
1128 | check_poison_obj(cachep, objp); |
1129 | #endif |
1130 | } |
1131 | if (cachep->flags & SLAB_RED_ZONE) { |
1132 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
1133 | slab_error(cachep, "start of a freed object " |
1134 | "was overwritten"); |
1135 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
1136 | slab_error(cachep, "end of a freed object " |
1137 | "was overwritten"); |
1138 | } |
1139 | if (cachep->dtor && !(cachep->flags & SLAB_POISON)) |
1140 | (cachep->dtor)(objp+obj_dbghead(cachep), cachep, 0); |
1141 | } |
1142 | #else |
1143 | if (cachep->dtor) { |
1144 | int i; |
1145 | for (i = 0; i < cachep->num; i++) { |
1146 | void* objp = slabp->s_mem+cachep->objsize*i; |
1147 | (cachep->dtor)(objp, cachep, 0); |
1148 | } |
1149 | } |
1150 | #endif |
1151 | |
1152 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { |
1153 | struct slab_rcu *slab_rcu; |
1154 | |
1155 | slab_rcu = (struct slab_rcu *) slabp; |
1156 | slab_rcu->cachep = cachep; |
1157 | slab_rcu->addr = addr; |
1158 | call_rcu(&slab_rcu->head, kmem_rcu_free); |
1159 | } else { |
1160 | kmem_freepages(cachep, addr); |
1161 | if (OFF_SLAB(cachep)) |
1162 | kmem_cache_free(cachep->slabp_cache, slabp); |
1163 | } |
1164 | } |
1165 | |
1166 | /** |
1167 | * kmem_cache_create - Create a cache. |
1168 | * @name: A string which is used in /proc/slabinfo to identify this cache. |
1169 | * @size: The size of objects to be created in this cache. |
1170 | * @align: The required alignment for the objects. |
1171 | * @flags: SLAB flags |
1172 | * @ctor: A constructor for the objects. |
1173 | * @dtor: A destructor for the objects. |
1174 | * |
1175 | * Returns a ptr to the cache on success, NULL on failure. |
1176 | * Cannot be called within a int, but can be interrupted. |
1177 | * The @ctor is run when new pages are allocated by the cache |
1178 | * and the @dtor is run before the pages are handed back. |
1179 | * |
1180 | * @name must be valid until the cache is destroyed. This implies that |
1181 | * the module calling this has to destroy the cache before getting |
1182 | * unloaded. |
1183 | * |
1184 | * The flags are |
1185 | * |
1186 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
1187 | * to catch references to uninitialised memory. |
1188 | * |
1189 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
1190 | * for buffer overruns. |
1191 | * |
1192 | * %SLAB_NO_REAP - Don't automatically reap this cache when we're under |
1193 | * memory pressure. |
1194 | * |
1195 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
1196 | * cacheline. This can be beneficial if you're counting cycles as closely |
1197 | * as davem. |
1198 | */ |
1199 | kmem_cache_t * |
1200 | kmem_cache_create (const char *name, size_t size, size_t align, |
1201 | unsigned long flags, void (*ctor)(void*, kmem_cache_t *, unsigned long), |
1202 | void (*dtor)(void*, kmem_cache_t *, unsigned long)) |
1203 | { |
1204 | size_t left_over, slab_size, ralign; |
1205 | kmem_cache_t *cachep = NULL; |
1206 | |
1207 | /* |
1208 | * Sanity checks... these are all serious usage bugs. |
1209 | */ |
1210 | if ((!name) || |
1211 | in_interrupt() || |
1212 | (size < BYTES_PER_WORD) || |
1213 | (size > (1<<MAX_OBJ_ORDER)*PAGE_SIZE) || |
1214 | (dtor && !ctor)) { |
1215 | printk(KERN_ERR "%s: Early error in slab %s\n", |
1216 | __FUNCTION__, name); |
1217 | BUG(); |
1218 | } |
1219 | |
1220 | #if DEBUG |
1221 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ |
1222 | if ((flags & SLAB_DEBUG_INITIAL) && !ctor) { |
1223 | /* No constructor, but inital state check requested */ |
1224 | printk(KERN_ERR "%s: No con, but init state check " |
1225 | "requested - %s\n", __FUNCTION__, name); |
1226 | flags &= ~SLAB_DEBUG_INITIAL; |
1227 | } |
1228 | |
1229 | #if FORCED_DEBUG |
1230 | /* |
1231 | * Enable redzoning and last user accounting, except for caches with |
1232 | * large objects, if the increased size would increase the object size |
1233 | * above the next power of two: caches with object sizes just above a |
1234 | * power of two have a significant amount of internal fragmentation. |
1235 | */ |
1236 | if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD))) |
1237 | flags |= SLAB_RED_ZONE|SLAB_STORE_USER; |
1238 | if (!(flags & SLAB_DESTROY_BY_RCU)) |
1239 | flags |= SLAB_POISON; |
1240 | #endif |
1241 | if (flags & SLAB_DESTROY_BY_RCU) |
1242 | BUG_ON(flags & SLAB_POISON); |
1243 | #endif |
1244 | if (flags & SLAB_DESTROY_BY_RCU) |
1245 | BUG_ON(dtor); |
1246 | |
1247 | /* |
1248 | * Always checks flags, a caller might be expecting debug |
1249 | * support which isn't available. |
1250 | */ |
1251 | if (flags & ~CREATE_MASK) |
1252 | BUG(); |
1253 | |
1254 | /* Check that size is in terms of words. This is needed to avoid |
1255 | * unaligned accesses for some archs when redzoning is used, and makes |
1256 | * sure any on-slab bufctl's are also correctly aligned. |
1257 | */ |
1258 | if (size & (BYTES_PER_WORD-1)) { |
1259 | size += (BYTES_PER_WORD-1); |
1260 | size &= ~(BYTES_PER_WORD-1); |
1261 | } |
1262 | |
1263 | /* calculate out the final buffer alignment: */ |
1264 | /* 1) arch recommendation: can be overridden for debug */ |
1265 | if (flags & SLAB_HWCACHE_ALIGN) { |
1266 | /* Default alignment: as specified by the arch code. |
1267 | * Except if an object is really small, then squeeze multiple |
1268 | * objects into one cacheline. |
1269 | */ |
1270 | ralign = cache_line_size(); |
1271 | while (size <= ralign/2) |
1272 | ralign /= 2; |
1273 | } else { |
1274 | ralign = BYTES_PER_WORD; |
1275 | } |
1276 | /* 2) arch mandated alignment: disables debug if necessary */ |
1277 | if (ralign < ARCH_SLAB_MINALIGN) { |
1278 | ralign = ARCH_SLAB_MINALIGN; |
1279 | if (ralign > BYTES_PER_WORD) |
1280 | flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER); |
1281 | } |
1282 | /* 3) caller mandated alignment: disables debug if necessary */ |
1283 | if (ralign < align) { |
1284 | ralign = align; |
1285 | if (ralign > BYTES_PER_WORD) |
1286 | flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER); |
1287 | } |
1288 | /* 4) Store it. Note that the debug code below can reduce |
1289 | * the alignment to BYTES_PER_WORD. |
1290 | */ |
1291 | align = ralign; |
1292 | |
1293 | /* Get cache's description obj. */ |
1294 | cachep = (kmem_cache_t *) kmem_cache_alloc(&cache_cache, SLAB_KERNEL); |
1295 | if (!cachep) |
1296 | goto opps; |
1297 | memset(cachep, 0, sizeof(kmem_cache_t)); |
1298 | |
1299 | #if DEBUG |
1300 | cachep->reallen = size; |
1301 | |
1302 | if (flags & SLAB_RED_ZONE) { |
1303 | /* redzoning only works with word aligned caches */ |
1304 | align = BYTES_PER_WORD; |
1305 | |
1306 | /* add space for red zone words */ |
1307 | cachep->dbghead += BYTES_PER_WORD; |
1308 | size += 2*BYTES_PER_WORD; |
1309 | } |
1310 | if (flags & SLAB_STORE_USER) { |
1311 | /* user store requires word alignment and |
1312 | * one word storage behind the end of the real |
1313 | * object. |
1314 | */ |
1315 | align = BYTES_PER_WORD; |
1316 | size += BYTES_PER_WORD; |
1317 | } |
1318 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) |
1319 | if (size > 128 && cachep->reallen > cache_line_size() && size < PAGE_SIZE) { |
1320 | cachep->dbghead += PAGE_SIZE - size; |
1321 | size = PAGE_SIZE; |
1322 | } |
1323 | #endif |
1324 | #endif |
1325 | |
1326 | /* Determine if the slab management is 'on' or 'off' slab. */ |
1327 | if (size >= (PAGE_SIZE>>3)) |
1328 | /* |
1329 | * Size is large, assume best to place the slab management obj |
1330 | * off-slab (should allow better packing of objs). |
1331 | */ |
1332 | flags |= CFLGS_OFF_SLAB; |
1333 | |
1334 | size = ALIGN(size, align); |
1335 | |
1336 | if ((flags & SLAB_RECLAIM_ACCOUNT) && size <= PAGE_SIZE) { |
1337 | /* |
1338 | * A VFS-reclaimable slab tends to have most allocations |
1339 | * as GFP_NOFS and we really don't want to have to be allocating |
1340 | * higher-order pages when we are unable to shrink dcache. |
1341 | */ |
1342 | cachep->gfporder = 0; |
1343 | cache_estimate(cachep->gfporder, size, align, flags, |
1344 | &left_over, &cachep->num); |
1345 | } else { |
1346 | /* |
1347 | * Calculate size (in pages) of slabs, and the num of objs per |
1348 | * slab. This could be made much more intelligent. For now, |
1349 | * try to avoid using high page-orders for slabs. When the |
1350 | * gfp() funcs are more friendly towards high-order requests, |
1351 | * this should be changed. |
1352 | */ |
1353 | do { |
1354 | unsigned int break_flag = 0; |
1355 | cal_wastage: |
1356 | cache_estimate(cachep->gfporder, size, align, flags, |
1357 | &left_over, &cachep->num); |
1358 | if (break_flag) |
1359 | break; |
1360 | if (cachep->gfporder >= MAX_GFP_ORDER) |
1361 | break; |
1362 | if (!cachep->num) |
1363 | goto next; |
1364 | if (flags & CFLGS_OFF_SLAB && |
1365 | cachep->num > offslab_limit) { |
1366 | /* This num of objs will cause problems. */ |
1367 | cachep->gfporder--; |
1368 | break_flag++; |
1369 | goto cal_wastage; |
1370 | } |
1371 | |
1372 | /* |
1373 | * Large num of objs is good, but v. large slabs are |
1374 | * currently bad for the gfp()s. |
1375 | */ |
1376 | if (cachep->gfporder >= slab_break_gfp_order) |
1377 | break; |
1378 | |
1379 | if ((left_over*8) <= (PAGE_SIZE<<cachep->gfporder)) |
1380 | break; /* Acceptable internal fragmentation. */ |
1381 | next: |
1382 | cachep->gfporder++; |
1383 | } while (1); |
1384 | } |
1385 | |
1386 | if (!cachep->num) { |
1387 | printk("kmem_cache_create: couldn't create cache %s.\n", name); |
1388 | kmem_cache_free(&cache_cache, cachep); |
1389 | cachep = NULL; |
1390 | goto opps; |
1391 | } |
1392 | slab_size = ALIGN(cachep->num*sizeof(kmem_bufctl_t) |
1393 | + sizeof(struct slab), align); |
1394 | |
1395 | /* |
1396 | * If the slab has been placed off-slab, and we have enough space then |
1397 | * move it on-slab. This is at the expense of any extra colouring. |
1398 | */ |
1399 | if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { |
1400 | flags &= ~CFLGS_OFF_SLAB; |
1401 | left_over -= slab_size; |
1402 | } |
1403 | |
1404 | if (flags & CFLGS_OFF_SLAB) { |
1405 | /* really off slab. No need for manual alignment */ |
1406 | slab_size = cachep->num*sizeof(kmem_bufctl_t)+sizeof(struct slab); |
1407 | } |
1408 | |
1409 | cachep->colour_off = cache_line_size(); |
1410 | /* Offset must be a multiple of the alignment. */ |
1411 | if (cachep->colour_off < align) |
1412 | cachep->colour_off = align; |
1413 | cachep->colour = left_over/cachep->colour_off; |
1414 | cachep->slab_size = slab_size; |
1415 | cachep->flags = flags; |
1416 | cachep->gfpflags = 0; |
1417 | if (flags & SLAB_CACHE_DMA) |
1418 | cachep->gfpflags |= GFP_DMA; |
1419 | spin_lock_init(&cachep->spinlock); |
1420 | cachep->objsize = size; |
1421 | /* NUMA */ |
1422 | INIT_LIST_HEAD(&cachep->lists.slabs_full); |
1423 | INIT_LIST_HEAD(&cachep->lists.slabs_partial); |
1424 | INIT_LIST_HEAD(&cachep->lists.slabs_free); |
1425 | |
1426 | if (flags & CFLGS_OFF_SLAB) |
1427 | cachep->slabp_cache = kmem_find_general_cachep(slab_size,0); |
1428 | cachep->ctor = ctor; |
1429 | cachep->dtor = dtor; |
1430 | cachep->name = name; |
1431 | |
1432 | /* Don't let CPUs to come and go */ |
1433 | lock_cpu_hotplug(); |
1434 | |
1435 | if (g_cpucache_up == FULL) { |
1436 | enable_cpucache(cachep); |
1437 | } else { |
1438 | if (g_cpucache_up == NONE) { |
1439 | /* Note: the first kmem_cache_create must create |
1440 | * the cache that's used by kmalloc(24), otherwise |
1441 | * the creation of further caches will BUG(). |
1442 | */ |
1443 | cachep->array[smp_processor_id()] = &initarray_generic.cache; |
1444 | g_cpucache_up = PARTIAL; |
1445 | } else { |
1446 | cachep->array[smp_processor_id()] = kmalloc(sizeof(struct arraycache_init),GFP_KERNEL); |
1447 | } |
1448 | BUG_ON(!ac_data(cachep)); |
1449 | ac_data(cachep)->avail = 0; |
1450 | ac_data(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
1451 | ac_data(cachep)->batchcount = 1; |
1452 | ac_data(cachep)->touched = 0; |
1453 | cachep->batchcount = 1; |
1454 | cachep->limit = BOOT_CPUCACHE_ENTRIES; |
1455 | cachep->free_limit = (1+num_online_cpus())*cachep->batchcount |
1456 | + cachep->num; |
1457 | } |
1458 | |
1459 | cachep->lists.next_reap = jiffies + REAPTIMEOUT_LIST3 + |
1460 | ((unsigned long)cachep)%REAPTIMEOUT_LIST3; |
1461 | |
1462 | /* Need the semaphore to access the chain. */ |
1463 | down(&cache_chain_sem); |
1464 | { |
1465 | struct list_head *p; |
1466 | mm_segment_t old_fs; |
1467 | |
1468 | old_fs = get_fs(); |
1469 | set_fs(KERNEL_DS); |
1470 | list_for_each(p, &cache_chain) { |
1471 | kmem_cache_t *pc = list_entry(p, kmem_cache_t, next); |
1472 | char tmp; |
1473 | /* This happens when the module gets unloaded and doesn't |
1474 | destroy its slab cache and noone else reuses the vmalloc |
1475 | area of the module. Print a warning. */ |
1476 | if (__get_user(tmp,pc->name)) { |
1477 | printk("SLAB: cache with size %d has lost its name\n", |
1478 | pc->objsize); |
1479 | continue; |
1480 | } |
1481 | if (!strcmp(pc->name,name)) { |
1482 | printk("kmem_cache_create: duplicate cache %s\n",name); |
1483 | up(&cache_chain_sem); |
1484 | unlock_cpu_hotplug(); |
1485 | BUG(); |
1486 | } |
1487 | } |
1488 | set_fs(old_fs); |
1489 | } |
1490 | |
1491 | /* cache setup completed, link it into the list */ |
1492 | list_add(&cachep->next, &cache_chain); |
1493 | up(&cache_chain_sem); |
1494 | unlock_cpu_hotplug(); |
1495 | opps: |
1496 | if (!cachep && (flags & SLAB_PANIC)) |
1497 | panic("kmem_cache_create(): failed to create slab `%s'\n", |
1498 | name); |
1499 | return cachep; |
1500 | } |
1501 | EXPORT_SYMBOL(kmem_cache_create); |
1502 | |
1503 | #if DEBUG |
1504 | static void check_irq_off(void) |
1505 | { |
1506 | BUG_ON(!irqs_disabled()); |
1507 | } |
1508 | |
1509 | static void check_irq_on(void) |
1510 | { |
1511 | BUG_ON(irqs_disabled()); |
1512 | } |
1513 | |
1514 | static void check_spinlock_acquired(kmem_cache_t *cachep) |
1515 | { |
1516 | #ifdef CONFIG_SMP |
1517 | check_irq_off(); |
1518 | BUG_ON(spin_trylock(&cachep->spinlock)); |
1519 | #endif |
1520 | } |
1521 | #else |
1522 | #define check_irq_off() do { } while(0) |
1523 | #define check_irq_on() do { } while(0) |
1524 | #define check_spinlock_acquired(x) do { } while(0) |
1525 | #endif |
1526 | |
1527 | /* |
1528 | * Waits for all CPUs to execute func(). |
1529 | */ |
1530 | static void smp_call_function_all_cpus(void (*func) (void *arg), void *arg) |
1531 | { |
1532 | check_irq_on(); |
1533 | preempt_disable(); |
1534 | |
1535 | local_irq_disable(); |
1536 | func(arg); |
1537 | local_irq_enable(); |
1538 | |
1539 | if (smp_call_function(func, arg, 1, 1)) |
1540 | BUG(); |
1541 | |
1542 | preempt_enable(); |
1543 | } |
1544 | |
1545 | static void drain_array_locked(kmem_cache_t* cachep, |
1546 | struct array_cache *ac, int force); |
1547 | |
1548 | static void do_drain(void *arg) |
1549 | { |
1550 | kmem_cache_t *cachep = (kmem_cache_t*)arg; |
1551 | struct array_cache *ac; |
1552 | |
1553 | check_irq_off(); |
1554 | ac = ac_data(cachep); |
1555 | spin_lock(&cachep->spinlock); |
1556 | free_block(cachep, &ac_entry(ac)[0], ac->avail); |
1557 | spin_unlock(&cachep->spinlock); |
1558 | ac->avail = 0; |
1559 | } |
1560 | |
1561 | static void drain_cpu_caches(kmem_cache_t *cachep) |
1562 | { |
1563 | smp_call_function_all_cpus(do_drain, cachep); |
1564 | check_irq_on(); |
1565 | spin_lock_irq(&cachep->spinlock); |
1566 | if (cachep->lists.shared) |
1567 | drain_array_locked(cachep, cachep->lists.shared, 1); |
1568 | spin_unlock_irq(&cachep->spinlock); |
1569 | } |
1570 | |
1571 | |
1572 | /* NUMA shrink all list3s */ |
1573 | static int __cache_shrink(kmem_cache_t *cachep) |
1574 | { |
1575 | struct slab *slabp; |
1576 | int ret; |
1577 | |
1578 | drain_cpu_caches(cachep); |
1579 | |
1580 | check_irq_on(); |
1581 | spin_lock_irq(&cachep->spinlock); |
1582 | |
1583 | for(;;) { |
1584 | struct list_head *p; |
1585 | |
1586 | p = cachep->lists.slabs_free.prev; |
1587 | if (p == &cachep->lists.slabs_free) |
1588 | break; |
1589 | |
1590 | slabp = list_entry(cachep->lists.slabs_free.prev, struct slab, list); |
1591 | #if DEBUG |
1592 | if (slabp->inuse) |
1593 | BUG(); |
1594 | #endif |
1595 | list_del(&slabp->list); |
1596 | |
1597 | cachep->lists.free_objects -= cachep->num; |
1598 | spin_unlock_irq(&cachep->spinlock); |
1599 | slab_destroy(cachep, slabp); |
1600 | spin_lock_irq(&cachep->spinlock); |
1601 | } |
1602 | ret = !list_empty(&cachep->lists.slabs_full) || |
1603 | !list_empty(&cachep->lists.slabs_partial); |
1604 | spin_unlock_irq(&cachep->spinlock); |
1605 | return ret; |
1606 | } |
1607 | |
1608 | /** |
1609 | * kmem_cache_shrink - Shrink a cache. |
1610 | * @cachep: The cache to shrink. |
1611 | * |
1612 | * Releases as many slabs as possible for a cache. |
1613 | * To help debugging, a zero exit status indicates all slabs were released. |
1614 | */ |
1615 | int kmem_cache_shrink(kmem_cache_t *cachep) |
1616 | { |
1617 | if (!cachep || in_interrupt()) |
1618 | BUG(); |
1619 | |
1620 | return __cache_shrink(cachep); |
1621 | } |
1622 | EXPORT_SYMBOL(kmem_cache_shrink); |
1623 | |
1624 | /** |
1625 | * kmem_cache_destroy - delete a cache |
1626 | * @cachep: the cache to destroy |
1627 | * |
1628 | * Remove a kmem_cache_t object from the slab cache. |
1629 | * Returns 0 on success. |
1630 | * |
1631 | * It is expected this function will be called by a module when it is |
1632 | * unloaded. This will remove the cache completely, and avoid a duplicate |
1633 | * cache being allocated each time a module is loaded and unloaded, if the |
1634 | * module doesn't have persistent in-kernel storage across loads and unloads. |
1635 | * |
1636 | * The cache must be empty before calling this function. |
1637 | * |
1638 | * The caller must guarantee that noone will allocate memory from the cache |
1639 | * during the kmem_cache_destroy(). |
1640 | */ |
1641 | int kmem_cache_destroy(kmem_cache_t * cachep) |
1642 | { |
1643 | int i; |
1644 | |
1645 | if (!cachep || in_interrupt()) |
1646 | BUG(); |
1647 | |
1648 | /* Don't let CPUs to come and go */ |
1649 | lock_cpu_hotplug(); |
1650 | |
1651 | /* Find the cache in the chain of caches. */ |
1652 | down(&cache_chain_sem); |
1653 | /* |
1654 | * the chain is never empty, cache_cache is never destroyed |
1655 | */ |
1656 | list_del(&cachep->next); |
1657 | up(&cache_chain_sem); |
1658 | |
1659 | if (__cache_shrink(cachep)) { |
1660 | slab_error(cachep, "Can't free all objects"); |
1661 | down(&cache_chain_sem); |
1662 | list_add(&cachep->next,&cache_chain); |
1663 | up(&cache_chain_sem); |
1664 | unlock_cpu_hotplug(); |
1665 | return 1; |
1666 | } |
1667 | |
1668 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) |
1669 | synchronize_rcu(); |
1670 | |
1671 | /* no cpu_online check required here since we clear the percpu |
1672 | * array on cpu offline and set this to NULL. |
1673 | */ |
1674 | for (i = 0; i < NR_CPUS; i++) |
1675 | kfree(cachep->array[i]); |
1676 | |
1677 | /* NUMA: free the list3 structures */ |
1678 | kfree(cachep->lists.shared); |
1679 | cachep->lists.shared = NULL; |
1680 | kmem_cache_free(&cache_cache, cachep); |
1681 | |
1682 | unlock_cpu_hotplug(); |
1683 | |
1684 | return 0; |
1685 | } |
1686 | EXPORT_SYMBOL(kmem_cache_destroy); |
1687 | |
1688 | /* Get the memory for a slab management obj. */ |
1689 | static struct slab* alloc_slabmgmt(kmem_cache_t *cachep, |
1690 | void *objp, int colour_off, unsigned int __nocast local_flags) |
1691 | { |
1692 | struct slab *slabp; |
1693 | |
1694 | if (OFF_SLAB(cachep)) { |
1695 | /* Slab management obj is off-slab. */ |
1696 | slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags); |
1697 | if (!slabp) |
1698 | return NULL; |
1699 | } else { |
1700 | slabp = objp+colour_off; |
1701 | colour_off += cachep->slab_size; |
1702 | } |
1703 | slabp->inuse = 0; |
1704 | slabp->colouroff = colour_off; |
1705 | slabp->s_mem = objp+colour_off; |
1706 | |
1707 | return slabp; |
1708 | } |
1709 | |
1710 | static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) |
1711 | { |
1712 | return (kmem_bufctl_t *)(slabp+1); |
1713 | } |
1714 | |
1715 | static void cache_init_objs(kmem_cache_t *cachep, |
1716 | struct slab *slabp, unsigned long ctor_flags) |
1717 | { |
1718 | int i; |
1719 | |
1720 | for (i = 0; i < cachep->num; i++) { |
1721 | void* objp = slabp->s_mem+cachep->objsize*i; |
1722 | #if DEBUG |
1723 | /* need to poison the objs? */ |
1724 | if (cachep->flags & SLAB_POISON) |
1725 | poison_obj(cachep, objp, POISON_FREE); |
1726 | if (cachep->flags & SLAB_STORE_USER) |
1727 | *dbg_userword(cachep, objp) = NULL; |
1728 | |
1729 | if (cachep->flags & SLAB_RED_ZONE) { |
1730 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
1731 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
1732 | } |
1733 | /* |
1734 | * Constructors are not allowed to allocate memory from |
1735 | * the same cache which they are a constructor for. |
1736 | * Otherwise, deadlock. They must also be threaded. |
1737 | */ |
1738 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) |
1739 | cachep->ctor(objp+obj_dbghead(cachep), cachep, ctor_flags); |
1740 | |
1741 | if (cachep->flags & SLAB_RED_ZONE) { |
1742 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
1743 | slab_error(cachep, "constructor overwrote the" |
1744 | " end of an object"); |
1745 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
1746 | slab_error(cachep, "constructor overwrote the" |
1747 | " start of an object"); |
1748 | } |
1749 | if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) |
1750 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0); |
1751 | #else |
1752 | if (cachep->ctor) |
1753 | cachep->ctor(objp, cachep, ctor_flags); |
1754 | #endif |
1755 | slab_bufctl(slabp)[i] = i+1; |
1756 | } |
1757 | slab_bufctl(slabp)[i-1] = BUFCTL_END; |
1758 | slabp->free = 0; |
1759 | } |
1760 | |
1761 | static void kmem_flagcheck(kmem_cache_t *cachep, unsigned int flags) |
1762 | { |
1763 | if (flags & SLAB_DMA) { |
1764 | if (!(cachep->gfpflags & GFP_DMA)) |
1765 | BUG(); |
1766 | } else { |
1767 | if (cachep->gfpflags & GFP_DMA) |
1768 | BUG(); |
1769 | } |
1770 | } |
1771 | |
1772 | static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp) |
1773 | { |
1774 | int i; |
1775 | struct page *page; |
1776 | |
1777 | /* Nasty!!!!!! I hope this is OK. */ |
1778 | i = 1 << cachep->gfporder; |
1779 | page = virt_to_page(objp); |
1780 | do { |
1781 | SET_PAGE_CACHE(page, cachep); |
1782 | SET_PAGE_SLAB(page, slabp); |
1783 | page++; |
1784 | } while (--i); |
1785 | } |
1786 | |
1787 | /* |
1788 | * Grow (by 1) the number of slabs within a cache. This is called by |
1789 | * kmem_cache_alloc() when there are no active objs left in a cache. |
1790 | */ |
1791 | static int cache_grow(kmem_cache_t *cachep, unsigned int __nocast flags, int nodeid) |
1792 | { |
1793 | struct slab *slabp; |
1794 | void *objp; |
1795 | size_t offset; |
1796 | unsigned int local_flags; |
1797 | unsigned long ctor_flags; |
1798 | |
1799 | /* Be lazy and only check for valid flags here, |
1800 | * keeping it out of the critical path in kmem_cache_alloc(). |
1801 | */ |
1802 | if (flags & ~(SLAB_DMA|SLAB_LEVEL_MASK|SLAB_NO_GROW)) |
1803 | BUG(); |
1804 | if (flags & SLAB_NO_GROW) |
1805 | return 0; |
1806 | |
1807 | ctor_flags = SLAB_CTOR_CONSTRUCTOR; |
1808 | local_flags = (flags & SLAB_LEVEL_MASK); |
1809 | if (!(local_flags & __GFP_WAIT)) |
1810 | /* |
1811 | * Not allowed to sleep. Need to tell a constructor about |
1812 | * this - it might need to know... |
1813 | */ |
1814 | ctor_flags |= SLAB_CTOR_ATOMIC; |
1815 | |
1816 | /* About to mess with non-constant members - lock. */ |
1817 | check_irq_off(); |
1818 | spin_lock(&cachep->spinlock); |
1819 | |
1820 | /* Get colour for the slab, and cal the next value. */ |
1821 | offset = cachep->colour_next; |
1822 | cachep->colour_next++; |
1823 | if (cachep->colour_next >= cachep->colour) |
1824 | cachep->colour_next = 0; |
1825 | offset *= cachep->colour_off; |
1826 | |
1827 | spin_unlock(&cachep->spinlock); |
1828 | |
1829 | if (local_flags & __GFP_WAIT) |
1830 | local_irq_enable(); |
1831 | |
1832 | /* |
1833 | * The test for missing atomic flag is performed here, rather than |
1834 | * the more obvious place, simply to reduce the critical path length |
1835 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they |
1836 | * will eventually be caught here (where it matters). |
1837 | */ |
1838 | kmem_flagcheck(cachep, flags); |
1839 | |
1840 | |
1841 | /* Get mem for the objs. */ |
1842 | if (!(objp = kmem_getpages(cachep, flags, nodeid))) |
1843 | goto failed; |
1844 | |
1845 | /* Get slab management. */ |
1846 | if (!(slabp = alloc_slabmgmt(cachep, objp, offset, local_flags))) |
1847 | goto opps1; |
1848 | |
1849 | set_slab_attr(cachep, slabp, objp); |
1850 | |
1851 | cache_init_objs(cachep, slabp, ctor_flags); |
1852 | |
1853 | if (local_flags & __GFP_WAIT) |
1854 | local_irq_disable(); |
1855 | check_irq_off(); |
1856 | spin_lock(&cachep->spinlock); |
1857 | |
1858 | /* Make slab active. */ |
1859 | list_add_tail(&slabp->list, &(list3_data(cachep)->slabs_free)); |
1860 | STATS_INC_GROWN(cachep); |
1861 | list3_data(cachep)->free_objects += cachep->num; |
1862 | spin_unlock(&cachep->spinlock); |
1863 | return 1; |
1864 | opps1: |
1865 | kmem_freepages(cachep, objp); |
1866 | failed: |
1867 | if (local_flags & __GFP_WAIT) |
1868 | local_irq_disable(); |
1869 | return 0; |
1870 | } |
1871 | |
1872 | #if DEBUG |
1873 | |
1874 | /* |
1875 | * Perform extra freeing checks: |
1876 | * - detect bad pointers. |
1877 | * - POISON/RED_ZONE checking |
1878 | * - destructor calls, for caches with POISON+dtor |
1879 | */ |
1880 | static void kfree_debugcheck(const void *objp) |
1881 | { |
1882 | struct page *page; |
1883 | |
1884 | if (!virt_addr_valid(objp)) { |
1885 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", |
1886 | (unsigned long)objp); |
1887 | BUG(); |
1888 | } |
1889 | page = virt_to_page(objp); |
1890 | if (!PageSlab(page)) { |
1891 | printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n", (unsigned long)objp); |
1892 | BUG(); |
1893 | } |
1894 | } |
1895 | |
1896 | static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp, |
1897 | void *caller) |
1898 | { |
1899 | struct page *page; |
1900 | unsigned int objnr; |
1901 | struct slab *slabp; |
1902 | |
1903 | objp -= obj_dbghead(cachep); |
1904 | kfree_debugcheck(objp); |
1905 | page = virt_to_page(objp); |
1906 | |
1907 | if (GET_PAGE_CACHE(page) != cachep) { |
1908 | printk(KERN_ERR "mismatch in kmem_cache_free: expected cache %p, got %p\n", |
1909 | GET_PAGE_CACHE(page),cachep); |
1910 | printk(KERN_ERR "%p is %s.\n", cachep, cachep->name); |
1911 | printk(KERN_ERR "%p is %s.\n", GET_PAGE_CACHE(page), GET_PAGE_CACHE(page)->name); |
1912 | WARN_ON(1); |
1913 | } |
1914 | slabp = GET_PAGE_SLAB(page); |
1915 | |
1916 | if (cachep->flags & SLAB_RED_ZONE) { |
1917 | if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || *dbg_redzone2(cachep, objp) != RED_ACTIVE) { |
1918 | slab_error(cachep, "double free, or memory outside" |
1919 | " object was overwritten"); |
1920 | printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n", |
1921 | objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp)); |
1922 | } |
1923 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
1924 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
1925 | } |
1926 | if (cachep->flags & SLAB_STORE_USER) |
1927 | *dbg_userword(cachep, objp) = caller; |
1928 | |
1929 | objnr = (objp-slabp->s_mem)/cachep->objsize; |
1930 | |
1931 | BUG_ON(objnr >= cachep->num); |
1932 | BUG_ON(objp != slabp->s_mem + objnr*cachep->objsize); |
1933 | |
1934 | if (cachep->flags & SLAB_DEBUG_INITIAL) { |
1935 | /* Need to call the slab's constructor so the |
1936 | * caller can perform a verify of its state (debugging). |
1937 | * Called without the cache-lock held. |
1938 | */ |
1939 | cachep->ctor(objp+obj_dbghead(cachep), |
1940 | cachep, SLAB_CTOR_CONSTRUCTOR|SLAB_CTOR_VERIFY); |
1941 | } |
1942 | if (cachep->flags & SLAB_POISON && cachep->dtor) { |
1943 | /* we want to cache poison the object, |
1944 | * call the destruction callback |
1945 | */ |
1946 | cachep->dtor(objp+obj_dbghead(cachep), cachep, 0); |
1947 | } |
1948 | if (cachep->flags & SLAB_POISON) { |
1949 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1950 | if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) { |
1951 | store_stackinfo(cachep, objp, (unsigned long)caller); |
1952 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0); |
1953 | } else { |
1954 | poison_obj(cachep, objp, POISON_FREE); |
1955 | } |
1956 | #else |
1957 | poison_obj(cachep, objp, POISON_FREE); |
1958 | #endif |
1959 | } |
1960 | return objp; |
1961 | } |
1962 | |
1963 | static void check_slabp(kmem_cache_t *cachep, struct slab *slabp) |
1964 | { |
1965 | kmem_bufctl_t i; |
1966 | int entries = 0; |
1967 | |
1968 | check_spinlock_acquired(cachep); |
1969 | /* Check slab's freelist to see if this obj is there. */ |
1970 | for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { |
1971 | entries++; |
1972 | if (entries > cachep->num || i >= cachep->num) |
1973 | goto bad; |
1974 | } |
1975 | if (entries != cachep->num - slabp->inuse) { |
1976 | bad: |
1977 | printk(KERN_ERR "slab: Internal list corruption detected in cache '%s'(%d), slabp %p(%d). Hexdump:\n", |
1978 | cachep->name, cachep->num, slabp, slabp->inuse); |
1979 | for (i=0;i<sizeof(slabp)+cachep->num*sizeof(kmem_bufctl_t);i++) { |
1980 | if ((i%16)==0) |
1981 | printk("\n%03x:", i); |
1982 | printk(" %02x", ((unsigned char*)slabp)[i]); |
1983 | } |
1984 | printk("\n"); |
1985 | BUG(); |
1986 | } |
1987 | } |
1988 | #else |
1989 | #define kfree_debugcheck(x) do { } while(0) |
1990 | #define cache_free_debugcheck(x,objp,z) (objp) |
1991 | #define check_slabp(x,y) do { } while(0) |
1992 | #endif |
1993 | |
1994 | static void *cache_alloc_refill(kmem_cache_t *cachep, unsigned int __nocast flags) |
1995 | { |
1996 | int batchcount; |
1997 | struct kmem_list3 *l3; |
1998 | struct array_cache *ac; |
1999 | |
2000 | check_irq_off(); |
2001 | ac = ac_data(cachep); |
2002 | retry: |
2003 | batchcount = ac->batchcount; |
2004 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
2005 | /* if there was little recent activity on this |
2006 | * cache, then perform only a partial refill. |
2007 | * Otherwise we could generate refill bouncing. |
2008 | */ |
2009 | batchcount = BATCHREFILL_LIMIT; |
2010 | } |
2011 | l3 = list3_data(cachep); |
2012 | |
2013 | BUG_ON(ac->avail > 0); |
2014 | spin_lock(&cachep->spinlock); |
2015 | if (l3->shared) { |
2016 | struct array_cache *shared_array = l3->shared; |
2017 | if (shared_array->avail) { |
2018 | if (batchcount > shared_array->avail) |
2019 | batchcount = shared_array->avail; |
2020 | shared_array->avail -= batchcount; |
2021 | ac->avail = batchcount; |
2022 | memcpy(ac_entry(ac), &ac_entry(shared_array)[shared_array->avail], |
2023 | sizeof(void*)*batchcount); |
2024 | shared_array->touched = 1; |
2025 | goto alloc_done; |
2026 | } |
2027 | } |
2028 | while (batchcount > 0) { |
2029 | struct list_head *entry; |
2030 | struct slab *slabp; |
2031 | /* Get slab alloc is to come from. */ |
2032 | entry = l3->slabs_partial.next; |
2033 | if (entry == &l3->slabs_partial) { |
2034 | l3->free_touched = 1; |
2035 | entry = l3->slabs_free.next; |
2036 | if (entry == &l3->slabs_free) |
2037 | goto must_grow; |
2038 | } |
2039 | |
2040 | slabp = list_entry(entry, struct slab, list); |
2041 | check_slabp(cachep, slabp); |
2042 | check_spinlock_acquired(cachep); |
2043 | while (slabp->inuse < cachep->num && batchcount--) { |
2044 | kmem_bufctl_t next; |
2045 | STATS_INC_ALLOCED(cachep); |
2046 | STATS_INC_ACTIVE(cachep); |
2047 | STATS_SET_HIGH(cachep); |
2048 | |
2049 | /* get obj pointer */ |
2050 | ac_entry(ac)[ac->avail++] = slabp->s_mem + slabp->free*cachep->objsize; |
2051 | |
2052 | slabp->inuse++; |
2053 | next = slab_bufctl(slabp)[slabp->free]; |
2054 | #if DEBUG |
2055 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; |
2056 | #endif |
2057 | slabp->free = next; |
2058 | } |
2059 | check_slabp(cachep, slabp); |
2060 | |
2061 | /* move slabp to correct slabp list: */ |
2062 | list_del(&slabp->list); |
2063 | if (slabp->free == BUFCTL_END) |
2064 | list_add(&slabp->list, &l3->slabs_full); |
2065 | else |
2066 | list_add(&slabp->list, &l3->slabs_partial); |
2067 | } |
2068 | |
2069 | must_grow: |
2070 | l3->free_objects -= ac->avail; |
2071 | alloc_done: |
2072 | spin_unlock(&cachep->spinlock); |
2073 | |
2074 | if (unlikely(!ac->avail)) { |
2075 | int x; |
2076 | x = cache_grow(cachep, flags, -1); |
2077 | |
2078 | // cache_grow can reenable interrupts, then ac could change. |
2079 | ac = ac_data(cachep); |
2080 | if (!x && ac->avail == 0) // no objects in sight? abort |
2081 | return NULL; |
2082 | |
2083 | if (!ac->avail) // objects refilled by interrupt? |
2084 | goto retry; |
2085 | } |
2086 | ac->touched = 1; |
2087 | return ac_entry(ac)[--ac->avail]; |
2088 | } |
2089 | |
2090 | static inline void |
2091 | cache_alloc_debugcheck_before(kmem_cache_t *cachep, unsigned int __nocast flags) |
2092 | { |
2093 | might_sleep_if(flags & __GFP_WAIT); |
2094 | #if DEBUG |
2095 | kmem_flagcheck(cachep, flags); |
2096 | #endif |
2097 | } |
2098 | |
2099 | #if DEBUG |
2100 | static void * |
2101 | cache_alloc_debugcheck_after(kmem_cache_t *cachep, |
2102 | unsigned long flags, void *objp, void *caller) |
2103 | { |
2104 | if (!objp) |
2105 | return objp; |
2106 | if (cachep->flags & SLAB_POISON) { |
2107 | #ifdef CONFIG_DEBUG_PAGEALLOC |
2108 | if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) |
2109 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 1); |
2110 | else |
2111 | check_poison_obj(cachep, objp); |
2112 | #else |
2113 | check_poison_obj(cachep, objp); |
2114 | #endif |
2115 | poison_obj(cachep, objp, POISON_INUSE); |
2116 | } |
2117 | if (cachep->flags & SLAB_STORE_USER) |
2118 | *dbg_userword(cachep, objp) = caller; |
2119 | |
2120 | if (cachep->flags & SLAB_RED_ZONE) { |
2121 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
2122 | slab_error(cachep, "double free, or memory outside" |
2123 | " object was overwritten"); |
2124 | printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n", |
2125 | objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp)); |
2126 | } |
2127 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
2128 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
2129 | } |
2130 | objp += obj_dbghead(cachep); |
2131 | if (cachep->ctor && cachep->flags & SLAB_POISON) { |
2132 | unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR; |
2133 | |
2134 | if (!(flags & __GFP_WAIT)) |
2135 | ctor_flags |= SLAB_CTOR_ATOMIC; |
2136 | |
2137 | cachep->ctor(objp, cachep, ctor_flags); |
2138 | } |
2139 | return objp; |
2140 | } |
2141 | #else |
2142 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
2143 | #endif |
2144 | |
2145 | |
2146 | static inline void *__cache_alloc(kmem_cache_t *cachep, unsigned int __nocast flags) |
2147 | { |
2148 | unsigned long save_flags; |
2149 | void* objp; |
2150 | struct array_cache *ac; |
2151 | |
2152 | cache_alloc_debugcheck_before(cachep, flags); |
2153 | |
2154 | local_irq_save(save_flags); |
2155 | ac = ac_data(cachep); |
2156 | if (likely(ac->avail)) { |
2157 | STATS_INC_ALLOCHIT(cachep); |
2158 | ac->touched = 1; |
2159 | objp = ac_entry(ac)[--ac->avail]; |
2160 | } else { |
2161 | STATS_INC_ALLOCMISS(cachep); |
2162 | objp = cache_alloc_refill(cachep, flags); |
2163 | } |
2164 | local_irq_restore(save_flags); |
2165 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, __builtin_return_address(0)); |
2166 | return objp; |
2167 | } |
2168 | |
2169 | /* |
2170 | * NUMA: different approach needed if the spinlock is moved into |
2171 | * the l3 structure |
2172 | */ |
2173 | |
2174 | static void free_block(kmem_cache_t *cachep, void **objpp, int nr_objects) |
2175 | { |
2176 | int i; |
2177 | |
2178 | check_spinlock_acquired(cachep); |
2179 | |
2180 | /* NUMA: move add into loop */ |
2181 | cachep->lists.free_objects += nr_objects; |
2182 | |
2183 | for (i = 0; i < nr_objects; i++) { |
2184 | void *objp = objpp[i]; |
2185 | struct slab *slabp; |
2186 | unsigned int objnr; |
2187 | |
2188 | slabp = GET_PAGE_SLAB(virt_to_page(objp)); |
2189 | list_del(&slabp->list); |
2190 | objnr = (objp - slabp->s_mem) / cachep->objsize; |
2191 | check_slabp(cachep, slabp); |
2192 | #if DEBUG |
2193 | if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) { |
2194 | printk(KERN_ERR "slab: double free detected in cache '%s', objp %p.\n", |
2195 | cachep->name, objp); |
2196 | BUG(); |
2197 | } |
2198 | #endif |
2199 | slab_bufctl(slabp)[objnr] = slabp->free; |
2200 | slabp->free = objnr; |
2201 | STATS_DEC_ACTIVE(cachep); |
2202 | slabp->inuse--; |
2203 | check_slabp(cachep, slabp); |
2204 | |
2205 | /* fixup slab chains */ |
2206 | if (slabp->inuse == 0) { |
2207 | if (cachep->lists.free_objects > cachep->free_limit) { |
2208 | cachep->lists.free_objects -= cachep->num; |
2209 | slab_destroy(cachep, slabp); |
2210 | } else { |
2211 | list_add(&slabp->list, |
2212 | &list3_data_ptr(cachep, objp)->slabs_free); |
2213 | } |
2214 | } else { |
2215 | /* Unconditionally move a slab to the end of the |
2216 | * partial list on free - maximum time for the |
2217 | * other objects to be freed, too. |
2218 | */ |
2219 | list_add_tail(&slabp->list, |
2220 | &list3_data_ptr(cachep, objp)->slabs_partial); |
2221 | } |
2222 | } |
2223 | } |
2224 | |
2225 | static void cache_flusharray(kmem_cache_t *cachep, struct array_cache *ac) |
2226 | { |
2227 | int batchcount; |
2228 | |
2229 | batchcount = ac->batchcount; |
2230 | #if DEBUG |
2231 | BUG_ON(!batchcount || batchcount > ac->avail); |
2232 | #endif |
2233 | check_irq_off(); |
2234 | spin_lock(&cachep->spinlock); |
2235 | if (cachep->lists.shared) { |
2236 | struct array_cache *shared_array = cachep->lists.shared; |
2237 | int max = shared_array->limit-shared_array->avail; |
2238 | if (max) { |
2239 | if (batchcount > max) |
2240 | batchcount = max; |
2241 | memcpy(&ac_entry(shared_array)[shared_array->avail], |
2242 | &ac_entry(ac)[0], |
2243 | sizeof(void*)*batchcount); |
2244 | shared_array->avail += batchcount; |
2245 | goto free_done; |
2246 | } |
2247 | } |
2248 | |
2249 | free_block(cachep, &ac_entry(ac)[0], batchcount); |
2250 | free_done: |
2251 | #if STATS |
2252 | { |
2253 | int i = 0; |
2254 | struct list_head *p; |
2255 | |
2256 | p = list3_data(cachep)->slabs_free.next; |
2257 | while (p != &(list3_data(cachep)->slabs_free)) { |
2258 | struct slab *slabp; |
2259 | |
2260 | slabp = list_entry(p, struct slab, list); |
2261 | BUG_ON(slabp->inuse); |
2262 | |
2263 | i++; |
2264 | p = p->next; |
2265 | } |
2266 | STATS_SET_FREEABLE(cachep, i); |
2267 | } |
2268 | #endif |
2269 | spin_unlock(&cachep->spinlock); |
2270 | ac->avail -= batchcount; |
2271 | memmove(&ac_entry(ac)[0], &ac_entry(ac)[batchcount], |
2272 | sizeof(void*)*ac->avail); |
2273 | } |
2274 | |
2275 | /* |
2276 | * __cache_free |
2277 | * Release an obj back to its cache. If the obj has a constructed |
2278 | * state, it must be in this state _before_ it is released. |
2279 | * |
2280 | * Called with disabled ints. |
2281 | */ |
2282 | static inline void __cache_free(kmem_cache_t *cachep, void *objp) |
2283 | { |
2284 | struct array_cache *ac = ac_data(cachep); |
2285 | |
2286 | check_irq_off(); |
2287 | objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); |
2288 | |
2289 | if (likely(ac->avail < ac->limit)) { |
2290 | STATS_INC_FREEHIT(cachep); |
2291 | ac_entry(ac)[ac->avail++] = objp; |
2292 | return; |
2293 | } else { |
2294 | STATS_INC_FREEMISS(cachep); |
2295 | cache_flusharray(cachep, ac); |
2296 | ac_entry(ac)[ac->avail++] = objp; |
2297 | } |
2298 | } |
2299 | |
2300 | /** |
2301 | * kmem_cache_alloc - Allocate an object |
2302 | * @cachep: The cache to allocate from. |
2303 | * @flags: See kmalloc(). |
2304 | * |
2305 | * Allocate an object from this cache. The flags are only relevant |
2306 | * if the cache has no available objects. |
2307 | */ |
2308 | void *kmem_cache_alloc(kmem_cache_t *cachep, unsigned int __nocast flags) |
2309 | { |
2310 | return __cache_alloc(cachep, flags); |
2311 | } |
2312 | EXPORT_SYMBOL(kmem_cache_alloc); |
2313 | |
2314 | /** |
2315 | * kmem_ptr_validate - check if an untrusted pointer might |
2316 | * be a slab entry. |
2317 | * @cachep: the cache we're checking against |
2318 | * @ptr: pointer to validate |
2319 | * |
2320 | * This verifies that the untrusted pointer looks sane: |
2321 | * it is _not_ a guarantee that the pointer is actually |
2322 | * part of the slab cache in question, but it at least |
2323 | * validates that the pointer can be dereferenced and |
2324 | * looks half-way sane. |
2325 | * |
2326 | * Currently only used for dentry validation. |
2327 | */ |
2328 | int fastcall kmem_ptr_validate(kmem_cache_t *cachep, void *ptr) |
2329 | { |
2330 | unsigned long addr = (unsigned long) ptr; |
2331 | unsigned long min_addr = PAGE_OFFSET; |
2332 | unsigned long align_mask = BYTES_PER_WORD-1; |
2333 | unsigned long size = cachep->objsize; |
2334 | struct page *page; |
2335 | |
2336 | if (unlikely(addr < min_addr)) |
2337 | goto out; |
2338 | if (unlikely(addr > (unsigned long)high_memory - size)) |
2339 | goto out; |
2340 | if (unlikely(addr & align_mask)) |
2341 | goto out; |
2342 | if (unlikely(!kern_addr_valid(addr))) |
2343 | goto out; |
2344 | if (unlikely(!kern_addr_valid(addr + size - 1))) |
2345 | goto out; |
2346 | page = virt_to_page(ptr); |
2347 | if (unlikely(!PageSlab(page))) |
2348 | goto out; |
2349 | if (unlikely(GET_PAGE_CACHE(page) != cachep)) |
2350 | goto out; |
2351 | return 1; |
2352 | out: |
2353 | return 0; |
2354 | } |
2355 | |
2356 | #ifdef CONFIG_NUMA |
2357 | /** |
2358 | * kmem_cache_alloc_node - Allocate an object on the specified node |
2359 | * @cachep: The cache to allocate from. |
2360 | * @flags: See kmalloc(). |
2361 | * @nodeid: node number of the target node. |
2362 | * |
2363 | * Identical to kmem_cache_alloc, except that this function is slow |
2364 | * and can sleep. And it will allocate memory on the given node, which |
2365 | * can improve the performance for cpu bound structures. |
2366 | */ |
2367 | void *kmem_cache_alloc_node(kmem_cache_t *cachep, int flags, int nodeid) |
2368 | { |
2369 | int loop; |
2370 | void *objp; |
2371 | struct slab *slabp; |
2372 | kmem_bufctl_t next; |
2373 | |
2374 | for (loop = 0;;loop++) { |
2375 | struct list_head *q; |
2376 | |
2377 | objp = NULL; |
2378 | check_irq_on(); |
2379 | spin_lock_irq(&cachep->spinlock); |
2380 | /* walk through all partial and empty slab and find one |
2381 | * from the right node */ |
2382 | list_for_each(q,&cachep->lists.slabs_partial) { |
2383 | slabp = list_entry(q, struct slab, list); |
2384 | |
2385 | if (page_to_nid(virt_to_page(slabp->s_mem)) == nodeid || |
2386 | loop > 2) |
2387 | goto got_slabp; |
2388 | } |
2389 | list_for_each(q, &cachep->lists.slabs_free) { |
2390 | slabp = list_entry(q, struct slab, list); |
2391 | |
2392 | if (page_to_nid(virt_to_page(slabp->s_mem)) == nodeid || |
2393 | loop > 2) |
2394 | goto got_slabp; |
2395 | } |
2396 | spin_unlock_irq(&cachep->spinlock); |
2397 | |
2398 | local_irq_disable(); |
2399 | if (!cache_grow(cachep, flags, nodeid)) { |
2400 | local_irq_enable(); |
2401 | return NULL; |
2402 | } |
2403 | local_irq_enable(); |
2404 | } |
2405 | got_slabp: |
2406 | /* found one: allocate object */ |
2407 | check_slabp(cachep, slabp); |
2408 | check_spinlock_acquired(cachep); |
2409 | |
2410 | STATS_INC_ALLOCED(cachep); |
2411 | STATS_INC_ACTIVE(cachep); |
2412 | STATS_SET_HIGH(cachep); |
2413 | STATS_INC_NODEALLOCS(cachep); |
2414 | |
2415 | objp = slabp->s_mem + slabp->free*cachep->objsize; |
2416 | |
2417 | slabp->inuse++; |
2418 | next = slab_bufctl(slabp)[slabp->free]; |
2419 | #if DEBUG |
2420 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; |
2421 | #endif |
2422 | slabp->free = next; |
2423 | check_slabp(cachep, slabp); |
2424 | |
2425 | /* move slabp to correct slabp list: */ |
2426 | list_del(&slabp->list); |
2427 | if (slabp->free == BUFCTL_END) |
2428 | list_add(&slabp->list, &cachep->lists.slabs_full); |
2429 | else |
2430 | list_add(&slabp->list, &cachep->lists.slabs_partial); |
2431 | |
2432 | list3_data(cachep)->free_objects--; |
2433 | spin_unlock_irq(&cachep->spinlock); |
2434 | |
2435 | objp = cache_alloc_debugcheck_after(cachep, GFP_KERNEL, objp, |
2436 | __builtin_return_address(0)); |
2437 | return objp; |
2438 | } |
2439 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
2440 | |
2441 | void *kmalloc_node(size_t size, int flags, int node) |
2442 | { |
2443 | kmem_cache_t *cachep; |
2444 | |
2445 | cachep = kmem_find_general_cachep(size, flags); |
2446 | if (unlikely(cachep == NULL)) |
2447 | return NULL; |
2448 | return kmem_cache_alloc_node(cachep, flags, node); |
2449 | } |
2450 | EXPORT_SYMBOL(kmalloc_node); |
2451 | #endif |
2452 | |
2453 | /** |
2454 | * kmalloc - allocate memory |
2455 | * @size: how many bytes of memory are required. |
2456 | * @flags: the type of memory to allocate. |
2457 | * |
2458 | * kmalloc is the normal method of allocating memory |
2459 | * in the kernel. |
2460 | * |
2461 | * The @flags argument may be one of: |
2462 | * |
2463 | * %GFP_USER - Allocate memory on behalf of user. May sleep. |
2464 | * |
2465 | * %GFP_KERNEL - Allocate normal kernel ram. May sleep. |
2466 | * |
2467 | * %GFP_ATOMIC - Allocation will not sleep. Use inside interrupt handlers. |
2468 | * |
2469 | * Additionally, the %GFP_DMA flag may be set to indicate the memory |
2470 | * must be suitable for DMA. This can mean different things on different |
2471 | * platforms. For example, on i386, it means that the memory must come |
2472 | * from the first 16MB. |
2473 | */ |
2474 | void *__kmalloc(size_t size, unsigned int __nocast flags) |
2475 | { |
2476 | kmem_cache_t *cachep; |
2477 | |
2478 | /* If you want to save a few bytes .text space: replace |
2479 | * __ with kmem_. |
2480 | * Then kmalloc uses the uninlined functions instead of the inline |
2481 | * functions. |
2482 | */ |
2483 | cachep = __find_general_cachep(size, flags); |
2484 | if (unlikely(cachep == NULL)) |
2485 | return NULL; |
2486 | return __cache_alloc(cachep, flags); |
2487 | } |
2488 | EXPORT_SYMBOL(__kmalloc); |
2489 | |
2490 | #ifdef CONFIG_SMP |
2491 | /** |
2492 | * __alloc_percpu - allocate one copy of the object for every present |
2493 | * cpu in the system, zeroing them. |
2494 | * Objects should be dereferenced using the per_cpu_ptr macro only. |
2495 | * |
2496 | * @size: how many bytes of memory are required. |
2497 | * @align: the alignment, which can't be greater than SMP_CACHE_BYTES. |
2498 | */ |
2499 | void *__alloc_percpu(size_t size, size_t align) |
2500 | { |
2501 | int i; |
2502 | struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL); |
2503 | |
2504 | if (!pdata) |
2505 | return NULL; |
2506 | |
2507 | for (i = 0; i < NR_CPUS; i++) { |
2508 | if (!cpu_possible(i)) |
2509 | continue; |
2510 | pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, |
2511 | cpu_to_node(i)); |
2512 | |
2513 | if (!pdata->ptrs[i]) |
2514 | goto unwind_oom; |
2515 | memset(pdata->ptrs[i], 0, size); |
2516 | } |
2517 | |
2518 | /* Catch derefs w/o wrappers */ |
2519 | return (void *) (~(unsigned long) pdata); |
2520 | |
2521 | unwind_oom: |
2522 | while (--i >= 0) { |
2523 | if (!cpu_possible(i)) |
2524 | continue; |
2525 | kfree(pdata->ptrs[i]); |
2526 | } |
2527 | kfree(pdata); |
2528 | return NULL; |
2529 | } |
2530 | EXPORT_SYMBOL(__alloc_percpu); |
2531 | #endif |
2532 | |
2533 | /** |
2534 | * kmem_cache_free - Deallocate an object |
2535 | * @cachep: The cache the allocation was from. |
2536 | * @objp: The previously allocated object. |
2537 | * |
2538 | * Free an object which was previously allocated from this |
2539 | * cache. |
2540 | */ |
2541 | void kmem_cache_free(kmem_cache_t *cachep, void *objp) |
2542 | { |
2543 | unsigned long flags; |
2544 | |
2545 | local_irq_save(flags); |
2546 | __cache_free(cachep, objp); |
2547 | local_irq_restore(flags); |
2548 | } |
2549 | EXPORT_SYMBOL(kmem_cache_free); |
2550 | |
2551 | /** |
2552 | * kcalloc - allocate memory for an array. The memory is set to zero. |
2553 | * @n: number of elements. |
2554 | * @size: element size. |
2555 | * @flags: the type of memory to allocate. |
2556 | */ |
2557 | void *kcalloc(size_t n, size_t size, unsigned int __nocast flags) |
2558 | { |
2559 | void *ret = NULL; |
2560 | |
2561 | if (n != 0 && size > INT_MAX / n) |
2562 | return ret; |
2563 | |
2564 | ret = kmalloc(n * size, flags); |
2565 | if (ret) |
2566 | memset(ret, 0, n * size); |
2567 | return ret; |
2568 | } |
2569 | EXPORT_SYMBOL(kcalloc); |
2570 | |
2571 | /** |
2572 | * kfree - free previously allocated memory |
2573 | * @objp: pointer returned by kmalloc. |
2574 | * |
2575 | * Don't free memory not originally allocated by kmalloc() |
2576 | * or you will run into trouble. |
2577 | */ |
2578 | void kfree(const void *objp) |
2579 | { |
2580 | kmem_cache_t *c; |
2581 | unsigned long flags; |
2582 | |
2583 | if (unlikely(!objp)) |
2584 | return; |
2585 | local_irq_save(flags); |
2586 | kfree_debugcheck(objp); |
2587 | c = GET_PAGE_CACHE(virt_to_page(objp)); |
2588 | __cache_free(c, (void*)objp); |
2589 | local_irq_restore(flags); |
2590 | } |
2591 | EXPORT_SYMBOL(kfree); |
2592 | |
2593 | #ifdef CONFIG_SMP |
2594 | /** |
2595 | * free_percpu - free previously allocated percpu memory |
2596 | * @objp: pointer returned by alloc_percpu. |
2597 | * |
2598 | * Don't free memory not originally allocated by alloc_percpu() |
2599 | * The complemented objp is to check for that. |
2600 | */ |
2601 | void |
2602 | free_percpu(const void *objp) |
2603 | { |
2604 | int i; |
2605 | struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp); |
2606 | |
2607 | for (i = 0; i < NR_CPUS; i++) { |
2608 | if (!cpu_possible(i)) |
2609 | continue; |
2610 | kfree(p->ptrs[i]); |
2611 | } |
2612 | kfree(p); |
2613 | } |
2614 | EXPORT_SYMBOL(free_percpu); |
2615 | #endif |
2616 | |
2617 | unsigned int kmem_cache_size(kmem_cache_t *cachep) |
2618 | { |
2619 | return obj_reallen(cachep); |
2620 | } |
2621 | EXPORT_SYMBOL(kmem_cache_size); |
2622 | |
2623 | struct ccupdate_struct { |
2624 | kmem_cache_t *cachep; |
2625 | struct array_cache *new[NR_CPUS]; |
2626 | }; |
2627 | |
2628 | static void do_ccupdate_local(void *info) |
2629 | { |
2630 | struct ccupdate_struct *new = (struct ccupdate_struct *)info; |
2631 | struct array_cache *old; |
2632 | |
2633 | check_irq_off(); |
2634 | old = ac_data(new->cachep); |
2635 | |
2636 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; |
2637 | new->new[smp_processor_id()] = old; |
2638 | } |
2639 | |
2640 | |
2641 | static int do_tune_cpucache(kmem_cache_t *cachep, int limit, int batchcount, |
2642 | int shared) |
2643 | { |
2644 | struct ccupdate_struct new; |
2645 | struct array_cache *new_shared; |
2646 | int i; |
2647 | |
2648 | memset(&new.new,0,sizeof(new.new)); |
2649 | for (i = 0; i < NR_CPUS; i++) { |
2650 | if (cpu_online(i)) { |
2651 | new.new[i] = alloc_arraycache(i, limit, batchcount); |
2652 | if (!new.new[i]) { |
2653 | for (i--; i >= 0; i--) kfree(new.new[i]); |
2654 | return -ENOMEM; |
2655 | } |
2656 | } else { |
2657 | new.new[i] = NULL; |
2658 | } |
2659 | } |
2660 | new.cachep = cachep; |
2661 | |
2662 | smp_call_function_all_cpus(do_ccupdate_local, (void *)&new); |
2663 | |
2664 | check_irq_on(); |
2665 | spin_lock_irq(&cachep->spinlock); |
2666 | cachep->batchcount = batchcount; |
2667 | cachep->limit = limit; |
2668 | cachep->free_limit = (1+num_online_cpus())*cachep->batchcount + cachep->num; |
2669 | spin_unlock_irq(&cachep->spinlock); |
2670 | |
2671 | for (i = 0; i < NR_CPUS; i++) { |
2672 | struct array_cache *ccold = new.new[i]; |
2673 | if (!ccold) |
2674 | continue; |
2675 | spin_lock_irq(&cachep->spinlock); |
2676 | free_block(cachep, ac_entry(ccold), ccold->avail); |
2677 | spin_unlock_irq(&cachep->spinlock); |
2678 | kfree(ccold); |
2679 | } |
2680 | new_shared = alloc_arraycache(-1, batchcount*shared, 0xbaadf00d); |
2681 | if (new_shared) { |
2682 | struct array_cache *old; |
2683 | |
2684 | spin_lock_irq(&cachep->spinlock); |
2685 | old = cachep->lists.shared; |
2686 | cachep->lists.shared = new_shared; |
2687 | if (old) |
2688 | free_block(cachep, ac_entry(old), old->avail); |
2689 | spin_unlock_irq(&cachep->spinlock); |
2690 | kfree(old); |
2691 | } |
2692 | |
2693 | return 0; |
2694 | } |
2695 | |
2696 | |
2697 | static void enable_cpucache(kmem_cache_t *cachep) |
2698 | { |
2699 | int err; |
2700 | int limit, shared; |
2701 | |
2702 | /* The head array serves three purposes: |
2703 | * - create a LIFO ordering, i.e. return objects that are cache-warm |
2704 | * - reduce the number of spinlock operations. |
2705 | * - reduce the number of linked list operations on the slab and |
2706 | * bufctl chains: array operations are cheaper. |
2707 | * The numbers are guessed, we should auto-tune as described by |
2708 | * Bonwick. |
2709 | */ |
2710 | if (cachep->objsize > 131072) |
2711 | limit = 1; |
2712 | else if (cachep->objsize > PAGE_SIZE) |
2713 | limit = 8; |
2714 | else if (cachep->objsize > 1024) |
2715 | limit = 24; |
2716 | else if (cachep->objsize > 256) |
2717 | limit = 54; |
2718 | else |
2719 | limit = 120; |
2720 | |
2721 | /* Cpu bound tasks (e.g. network routing) can exhibit cpu bound |
2722 | * allocation behaviour: Most allocs on one cpu, most free operations |
2723 | * on another cpu. For these cases, an efficient object passing between |
2724 | * cpus is necessary. This is provided by a shared array. The array |
2725 | * replaces Bonwick's magazine layer. |
2726 | * On uniprocessor, it's functionally equivalent (but less efficient) |
2727 | * to a larger limit. Thus disabled by default. |
2728 | */ |
2729 | shared = 0; |
2730 | #ifdef CONFIG_SMP |
2731 | if (cachep->objsize <= PAGE_SIZE) |
2732 | shared = 8; |
2733 | #endif |
2734 | |
2735 | #if DEBUG |
2736 | /* With debugging enabled, large batchcount lead to excessively |
2737 | * long periods with disabled local interrupts. Limit the |
2738 | * batchcount |
2739 | */ |
2740 | if (limit > 32) |
2741 | limit = 32; |
2742 | #endif |
2743 | err = do_tune_cpucache(cachep, limit, (limit+1)/2, shared); |
2744 | if (err) |
2745 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", |
2746 | cachep->name, -err); |
2747 | } |
2748 | |
2749 | static void drain_array_locked(kmem_cache_t *cachep, |
2750 | struct array_cache *ac, int force) |
2751 | { |
2752 | int tofree; |
2753 | |
2754 | check_spinlock_acquired(cachep); |
2755 | if (ac->touched && !force) { |
2756 | ac->touched = 0; |
2757 | } else if (ac->avail) { |
2758 | tofree = force ? ac->avail : (ac->limit+4)/5; |
2759 | if (tofree > ac->avail) { |
2760 | tofree = (ac->avail+1)/2; |
2761 | } |
2762 | free_block(cachep, ac_entry(ac), tofree); |
2763 | ac->avail -= tofree; |
2764 | memmove(&ac_entry(ac)[0], &ac_entry(ac)[tofree], |
2765 | sizeof(void*)*ac->avail); |
2766 | } |
2767 | } |
2768 | |
2769 | /** |
2770 | * cache_reap - Reclaim memory from caches. |
2771 | * |
2772 | * Called from workqueue/eventd every few seconds. |
2773 | * Purpose: |
2774 | * - clear the per-cpu caches for this CPU. |
2775 | * - return freeable pages to the main free memory pool. |
2776 | * |
2777 | * If we cannot acquire the cache chain semaphore then just give up - we'll |
2778 | * try again on the next iteration. |
2779 | */ |
2780 | static void cache_reap(void *unused) |
2781 | { |
2782 | struct list_head *walk; |
2783 | |
2784 | if (down_trylock(&cache_chain_sem)) { |
2785 | /* Give up. Setup the next iteration. */ |
2786 | schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC + smp_processor_id()); |
2787 | return; |
2788 | } |
2789 | |
2790 | list_for_each(walk, &cache_chain) { |
2791 | kmem_cache_t *searchp; |
2792 | struct list_head* p; |
2793 | int tofree; |
2794 | struct slab *slabp; |
2795 | |
2796 | searchp = list_entry(walk, kmem_cache_t, next); |
2797 | |
2798 | if (searchp->flags & SLAB_NO_REAP) |
2799 | goto next; |
2800 | |
2801 | check_irq_on(); |
2802 | |
2803 | spin_lock_irq(&searchp->spinlock); |
2804 | |
2805 | drain_array_locked(searchp, ac_data(searchp), 0); |
2806 | |
2807 | if(time_after(searchp->lists.next_reap, jiffies)) |
2808 | goto next_unlock; |
2809 | |
2810 | searchp->lists.next_reap = jiffies + REAPTIMEOUT_LIST3; |
2811 | |
2812 | if (searchp->lists.shared) |
2813 | drain_array_locked(searchp, searchp->lists.shared, 0); |
2814 | |
2815 | if (searchp->lists.free_touched) { |
2816 | searchp->lists.free_touched = 0; |
2817 | goto next_unlock; |
2818 | } |
2819 | |
2820 | tofree = (searchp->free_limit+5*searchp->num-1)/(5*searchp->num); |
2821 | do { |
2822 | p = list3_data(searchp)->slabs_free.next; |
2823 | if (p == &(list3_data(searchp)->slabs_free)) |
2824 | break; |
2825 | |
2826 | slabp = list_entry(p, struct slab, list); |
2827 | BUG_ON(slabp->inuse); |
2828 | list_del(&slabp->list); |
2829 | STATS_INC_REAPED(searchp); |
2830 | |
2831 | /* Safe to drop the lock. The slab is no longer |
2832 | * linked to the cache. |
2833 | * searchp cannot disappear, we hold |
2834 | * cache_chain_lock |
2835 | */ |
2836 | searchp->lists.free_objects -= searchp->num; |
2837 | spin_unlock_irq(&searchp->spinlock); |
2838 | slab_destroy(searchp, slabp); |
2839 | spin_lock_irq(&searchp->spinlock); |
2840 | } while(--tofree > 0); |
2841 | next_unlock: |
2842 | spin_unlock_irq(&searchp->spinlock); |
2843 | next: |
2844 | cond_resched(); |
2845 | } |
2846 | check_irq_on(); |
2847 | up(&cache_chain_sem); |
2848 | /* Setup the next iteration */ |
2849 | schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC + smp_processor_id()); |
2850 | } |
2851 | |
2852 | #ifdef CONFIG_PROC_FS |
2853 | |
2854 | static void *s_start(struct seq_file *m, loff_t *pos) |
2855 | { |
2856 | loff_t n = *pos; |
2857 | struct list_head *p; |
2858 | |
2859 | down(&cache_chain_sem); |
2860 | if (!n) { |
2861 | /* |
2862 | * Output format version, so at least we can change it |
2863 | * without _too_ many complaints. |
2864 | */ |
2865 | #if STATS |
2866 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); |
2867 | #else |
2868 | seq_puts(m, "slabinfo - version: 2.1\n"); |
2869 | #endif |
2870 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); |
2871 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
2872 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); |
2873 | #if STATS |
2874 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped>" |
2875 | " <error> <maxfreeable> <freelimit> <nodeallocs>"); |
2876 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); |
2877 | #endif |
2878 | seq_putc(m, '\n'); |
2879 | } |
2880 | p = cache_chain.next; |
2881 | while (n--) { |
2882 | p = p->next; |
2883 | if (p == &cache_chain) |
2884 | return NULL; |
2885 | } |
2886 | return list_entry(p, kmem_cache_t, next); |
2887 | } |
2888 | |
2889 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) |
2890 | { |
2891 | kmem_cache_t *cachep = p; |
2892 | ++*pos; |
2893 | return cachep->next.next == &cache_chain ? NULL |
2894 | : list_entry(cachep->next.next, kmem_cache_t, next); |
2895 | } |
2896 | |
2897 | static void s_stop(struct seq_file *m, void *p) |
2898 | { |
2899 | up(&cache_chain_sem); |
2900 | } |
2901 | |
2902 | static int s_show(struct seq_file *m, void *p) |
2903 | { |
2904 | kmem_cache_t *cachep = p; |
2905 | struct list_head *q; |
2906 | struct slab *slabp; |
2907 | unsigned long active_objs; |
2908 | unsigned long num_objs; |
2909 | unsigned long active_slabs = 0; |
2910 | unsigned long num_slabs; |
2911 | const char *name; |
2912 | char *error = NULL; |
2913 | |
2914 | check_irq_on(); |
2915 | spin_lock_irq(&cachep->spinlock); |
2916 | active_objs = 0; |
2917 | num_slabs = 0; |
2918 | list_for_each(q,&cachep->lists.slabs_full) { |
2919 | slabp = list_entry(q, struct slab, list); |
2920 | if (slabp->inuse != cachep->num && !error) |
2921 | error = "slabs_full accounting error"; |
2922 | active_objs += cachep->num; |
2923 | active_slabs++; |
2924 | } |
2925 | list_for_each(q,&cachep->lists.slabs_partial) { |
2926 | slabp = list_entry(q, struct slab, list); |
2927 | if (slabp->inuse == cachep->num && !error) |
2928 | error = "slabs_partial inuse accounting error"; |
2929 | if (!slabp->inuse && !error) |
2930 | error = "slabs_partial/inuse accounting error"; |
2931 | active_objs += slabp->inuse; |
2932 | active_slabs++; |
2933 | } |
2934 | list_for_each(q,&cachep->lists.slabs_free) { |
2935 | slabp = list_entry(q, struct slab, list); |
2936 | if (slabp->inuse && !error) |
2937 | error = "slabs_free/inuse accounting error"; |
2938 | num_slabs++; |
2939 | } |
2940 | num_slabs+=active_slabs; |
2941 | num_objs = num_slabs*cachep->num; |
2942 | if (num_objs - active_objs != cachep->lists.free_objects && !error) |
2943 | error = "free_objects accounting error"; |
2944 | |
2945 | name = cachep->name; |
2946 | if (error) |
2947 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); |
2948 | |
2949 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
2950 | name, active_objs, num_objs, cachep->objsize, |
2951 | cachep->num, (1<<cachep->gfporder)); |
2952 | seq_printf(m, " : tunables %4u %4u %4u", |
2953 | cachep->limit, cachep->batchcount, |
2954 | cachep->lists.shared->limit/cachep->batchcount); |
2955 | seq_printf(m, " : slabdata %6lu %6lu %6u", |
2956 | active_slabs, num_slabs, cachep->lists.shared->avail); |
2957 | #if STATS |
2958 | { /* list3 stats */ |
2959 | unsigned long high = cachep->high_mark; |
2960 | unsigned long allocs = cachep->num_allocations; |
2961 | unsigned long grown = cachep->grown; |
2962 | unsigned long reaped = cachep->reaped; |
2963 | unsigned long errors = cachep->errors; |
2964 | unsigned long max_freeable = cachep->max_freeable; |
2965 | unsigned long free_limit = cachep->free_limit; |
2966 | unsigned long node_allocs = cachep->node_allocs; |
2967 | |
2968 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu", |
2969 | allocs, high, grown, reaped, errors, |
2970 | max_freeable, free_limit, node_allocs); |
2971 | } |
2972 | /* cpu stats */ |
2973 | { |
2974 | unsigned long allochit = atomic_read(&cachep->allochit); |
2975 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
2976 | unsigned long freehit = atomic_read(&cachep->freehit); |
2977 | unsigned long freemiss = atomic_read(&cachep->freemiss); |
2978 | |
2979 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
2980 | allochit, allocmiss, freehit, freemiss); |
2981 | } |
2982 | #endif |
2983 | seq_putc(m, '\n'); |
2984 | spin_unlock_irq(&cachep->spinlock); |
2985 | return 0; |
2986 | } |
2987 | |
2988 | /* |
2989 | * slabinfo_op - iterator that generates /proc/slabinfo |
2990 | * |
2991 | * Output layout: |
2992 | * cache-name |
2993 | * num-active-objs |
2994 | * total-objs |
2995 | * object size |
2996 | * num-active-slabs |
2997 | * total-slabs |
2998 | * num-pages-per-slab |
2999 | * + further values on SMP and with statistics enabled |
3000 | */ |
3001 | |
3002 | struct seq_operations slabinfo_op = { |
3003 | .start = s_start, |
3004 | .next = s_next, |
3005 | .stop = s_stop, |
3006 | .show = s_show, |
3007 | }; |
3008 | |
3009 | #define MAX_SLABINFO_WRITE 128 |
3010 | /** |
3011 | * slabinfo_write - Tuning for the slab allocator |
3012 | * @file: unused |
3013 | * @buffer: user buffer |
3014 | * @count: data length |
3015 | * @ppos: unused |
3016 | */ |
3017 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
3018 | size_t count, loff_t *ppos) |
3019 | { |
3020 | char kbuf[MAX_SLABINFO_WRITE+1], *tmp; |
3021 | int limit, batchcount, shared, res; |
3022 | struct list_head *p; |
3023 | |
3024 | if (count > MAX_SLABINFO_WRITE) |
3025 | return -EINVAL; |
3026 | if (copy_from_user(&kbuf, buffer, count)) |
3027 | return -EFAULT; |
3028 | kbuf[MAX_SLABINFO_WRITE] = '\0'; |
3029 | |
3030 | tmp = strchr(kbuf, ' '); |
3031 | if (!tmp) |
3032 | return -EINVAL; |
3033 | *tmp = '\0'; |
3034 | tmp++; |
3035 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
3036 | return -EINVAL; |
3037 | |
3038 | /* Find the cache in the chain of caches. */ |
3039 | down(&cache_chain_sem); |
3040 | res = -EINVAL; |
3041 | list_for_each(p,&cache_chain) { |
3042 | kmem_cache_t *cachep = list_entry(p, kmem_cache_t, next); |
3043 | |
3044 | if (!strcmp(cachep->name, kbuf)) { |
3045 | if (limit < 1 || |
3046 | batchcount < 1 || |
3047 | batchcount > limit || |
3048 | shared < 0) { |
3049 | res = -EINVAL; |
3050 | } else { |
3051 | res = do_tune_cpucache(cachep, limit, batchcount, shared); |
3052 | } |
3053 | break; |
3054 | } |
3055 | } |
3056 | up(&cache_chain_sem); |
3057 | if (res >= 0) |
3058 | res = count; |
3059 | return res; |
3060 | } |
3061 | #endif |
3062 | |
3063 | unsigned int ksize(const void *objp) |
3064 | { |
3065 | kmem_cache_t *c; |
3066 | unsigned long flags; |
3067 | unsigned int size = 0; |
3068 | |
3069 | if (likely(objp != NULL)) { |
3070 | local_irq_save(flags); |
3071 | c = GET_PAGE_CACHE(virt_to_page(objp)); |
3072 | size = kmem_cache_size(c); |
3073 | local_irq_restore(flags); |
3074 | } |
3075 | |
3076 | return size; |
3077 | } |