]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | * | |
e498be7d CL |
78 | * 15 March 2005. NUMA slab allocator. |
79 | * Shai Fultheim <shai@scalex86.org>. | |
80 | * Shobhit Dayal <shobhit@calsoftinc.com> | |
81 | * Alok N Kataria <alokk@calsoftinc.com> | |
82 | * Christoph Lameter <christoph@lameter.com> | |
83 | * | |
84 | * Modified the slab allocator to be node aware on NUMA systems. | |
85 | * Each node has its own list of partial, free and full slabs. | |
86 | * All object allocations for a node occur from node specific slab lists. | |
1da177e4 LT |
87 | */ |
88 | ||
89 | #include <linux/config.h> | |
90 | #include <linux/slab.h> | |
91 | #include <linux/mm.h> | |
92 | #include <linux/swap.h> | |
93 | #include <linux/cache.h> | |
94 | #include <linux/interrupt.h> | |
95 | #include <linux/init.h> | |
96 | #include <linux/compiler.h> | |
97 | #include <linux/seq_file.h> | |
98 | #include <linux/notifier.h> | |
99 | #include <linux/kallsyms.h> | |
100 | #include <linux/cpu.h> | |
101 | #include <linux/sysctl.h> | |
102 | #include <linux/module.h> | |
103 | #include <linux/rcupdate.h> | |
543537bd | 104 | #include <linux/string.h> |
e498be7d | 105 | #include <linux/nodemask.h> |
1da177e4 LT |
106 | |
107 | #include <asm/uaccess.h> | |
108 | #include <asm/cacheflush.h> | |
109 | #include <asm/tlbflush.h> | |
110 | #include <asm/page.h> | |
111 | ||
112 | /* | |
113 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_DEBUG_INITIAL, | |
114 | * SLAB_RED_ZONE & SLAB_POISON. | |
115 | * 0 for faster, smaller code (especially in the critical paths). | |
116 | * | |
117 | * STATS - 1 to collect stats for /proc/slabinfo. | |
118 | * 0 for faster, smaller code (especially in the critical paths). | |
119 | * | |
120 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) | |
121 | */ | |
122 | ||
123 | #ifdef CONFIG_DEBUG_SLAB | |
124 | #define DEBUG 1 | |
125 | #define STATS 1 | |
126 | #define FORCED_DEBUG 1 | |
127 | #else | |
128 | #define DEBUG 0 | |
129 | #define STATS 0 | |
130 | #define FORCED_DEBUG 0 | |
131 | #endif | |
132 | ||
133 | ||
134 | /* Shouldn't this be in a header file somewhere? */ | |
135 | #define BYTES_PER_WORD sizeof(void *) | |
136 | ||
137 | #ifndef cache_line_size | |
138 | #define cache_line_size() L1_CACHE_BYTES | |
139 | #endif | |
140 | ||
141 | #ifndef ARCH_KMALLOC_MINALIGN | |
142 | /* | |
143 | * Enforce a minimum alignment for the kmalloc caches. | |
144 | * Usually, the kmalloc caches are cache_line_size() aligned, except when | |
145 | * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned. | |
146 | * Some archs want to perform DMA into kmalloc caches and need a guaranteed | |
147 | * alignment larger than BYTES_PER_WORD. ARCH_KMALLOC_MINALIGN allows that. | |
148 | * Note that this flag disables some debug features. | |
149 | */ | |
150 | #define ARCH_KMALLOC_MINALIGN 0 | |
151 | #endif | |
152 | ||
153 | #ifndef ARCH_SLAB_MINALIGN | |
154 | /* | |
155 | * Enforce a minimum alignment for all caches. | |
156 | * Intended for archs that get misalignment faults even for BYTES_PER_WORD | |
157 | * aligned buffers. Includes ARCH_KMALLOC_MINALIGN. | |
158 | * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables | |
159 | * some debug features. | |
160 | */ | |
161 | #define ARCH_SLAB_MINALIGN 0 | |
162 | #endif | |
163 | ||
164 | #ifndef ARCH_KMALLOC_FLAGS | |
165 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN | |
166 | #endif | |
167 | ||
168 | /* Legal flag mask for kmem_cache_create(). */ | |
169 | #if DEBUG | |
170 | # define CREATE_MASK (SLAB_DEBUG_INITIAL | SLAB_RED_ZONE | \ | |
171 | SLAB_POISON | SLAB_HWCACHE_ALIGN | \ | |
172 | SLAB_NO_REAP | SLAB_CACHE_DMA | \ | |
173 | SLAB_MUST_HWCACHE_ALIGN | SLAB_STORE_USER | \ | |
174 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | |
175 | SLAB_DESTROY_BY_RCU) | |
176 | #else | |
177 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | SLAB_NO_REAP | \ | |
178 | SLAB_CACHE_DMA | SLAB_MUST_HWCACHE_ALIGN | \ | |
179 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | |
180 | SLAB_DESTROY_BY_RCU) | |
181 | #endif | |
182 | ||
183 | /* | |
184 | * kmem_bufctl_t: | |
185 | * | |
186 | * Bufctl's are used for linking objs within a slab | |
187 | * linked offsets. | |
188 | * | |
189 | * This implementation relies on "struct page" for locating the cache & | |
190 | * slab an object belongs to. | |
191 | * This allows the bufctl structure to be small (one int), but limits | |
192 | * the number of objects a slab (not a cache) can contain when off-slab | |
193 | * bufctls are used. The limit is the size of the largest general cache | |
194 | * that does not use off-slab slabs. | |
195 | * For 32bit archs with 4 kB pages, is this 56. | |
196 | * This is not serious, as it is only for large objects, when it is unwise | |
197 | * to have too many per slab. | |
198 | * Note: This limit can be raised by introducing a general cache whose size | |
199 | * is less than 512 (PAGE_SIZE<<3), but greater than 256. | |
200 | */ | |
201 | ||
fa5b08d5 | 202 | typedef unsigned int kmem_bufctl_t; |
1da177e4 LT |
203 | #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) |
204 | #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) | |
205 | #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2) | |
206 | ||
207 | /* Max number of objs-per-slab for caches which use off-slab slabs. | |
208 | * Needed to avoid a possible looping condition in cache_grow(). | |
209 | */ | |
210 | static unsigned long offslab_limit; | |
211 | ||
212 | /* | |
213 | * struct slab | |
214 | * | |
215 | * Manages the objs in a slab. Placed either at the beginning of mem allocated | |
216 | * for a slab, or allocated from an general cache. | |
217 | * Slabs are chained into three list: fully used, partial, fully free slabs. | |
218 | */ | |
219 | struct slab { | |
220 | struct list_head list; | |
221 | unsigned long colouroff; | |
222 | void *s_mem; /* including colour offset */ | |
223 | unsigned int inuse; /* num of objs active in slab */ | |
224 | kmem_bufctl_t free; | |
e498be7d | 225 | unsigned short nodeid; |
1da177e4 LT |
226 | }; |
227 | ||
228 | /* | |
229 | * struct slab_rcu | |
230 | * | |
231 | * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to | |
232 | * arrange for kmem_freepages to be called via RCU. This is useful if | |
233 | * we need to approach a kernel structure obliquely, from its address | |
234 | * obtained without the usual locking. We can lock the structure to | |
235 | * stabilize it and check it's still at the given address, only if we | |
236 | * can be sure that the memory has not been meanwhile reused for some | |
237 | * other kind of object (which our subsystem's lock might corrupt). | |
238 | * | |
239 | * rcu_read_lock before reading the address, then rcu_read_unlock after | |
240 | * taking the spinlock within the structure expected at that address. | |
241 | * | |
242 | * We assume struct slab_rcu can overlay struct slab when destroying. | |
243 | */ | |
244 | struct slab_rcu { | |
245 | struct rcu_head head; | |
246 | kmem_cache_t *cachep; | |
247 | void *addr; | |
248 | }; | |
249 | ||
250 | /* | |
251 | * struct array_cache | |
252 | * | |
1da177e4 LT |
253 | * Purpose: |
254 | * - LIFO ordering, to hand out cache-warm objects from _alloc | |
255 | * - reduce the number of linked list operations | |
256 | * - reduce spinlock operations | |
257 | * | |
258 | * The limit is stored in the per-cpu structure to reduce the data cache | |
259 | * footprint. | |
260 | * | |
261 | */ | |
262 | struct array_cache { | |
263 | unsigned int avail; | |
264 | unsigned int limit; | |
265 | unsigned int batchcount; | |
266 | unsigned int touched; | |
e498be7d CL |
267 | spinlock_t lock; |
268 | void *entry[0]; /* | |
269 | * Must have this definition in here for the proper | |
270 | * alignment of array_cache. Also simplifies accessing | |
271 | * the entries. | |
272 | * [0] is for gcc 2.95. It should really be []. | |
273 | */ | |
1da177e4 LT |
274 | }; |
275 | ||
276 | /* bootstrap: The caches do not work without cpuarrays anymore, | |
277 | * but the cpuarrays are allocated from the generic caches... | |
278 | */ | |
279 | #define BOOT_CPUCACHE_ENTRIES 1 | |
280 | struct arraycache_init { | |
281 | struct array_cache cache; | |
282 | void * entries[BOOT_CPUCACHE_ENTRIES]; | |
283 | }; | |
284 | ||
285 | /* | |
e498be7d | 286 | * The slab lists for all objects. |
1da177e4 LT |
287 | */ |
288 | struct kmem_list3 { | |
289 | struct list_head slabs_partial; /* partial list first, better asm code */ | |
290 | struct list_head slabs_full; | |
291 | struct list_head slabs_free; | |
292 | unsigned long free_objects; | |
1da177e4 | 293 | unsigned long next_reap; |
e498be7d CL |
294 | int free_touched; |
295 | unsigned int free_limit; | |
296 | spinlock_t list_lock; | |
297 | struct array_cache *shared; /* shared per node */ | |
298 | struct array_cache **alien; /* on other nodes */ | |
1da177e4 LT |
299 | }; |
300 | ||
e498be7d CL |
301 | /* |
302 | * Need this for bootstrapping a per node allocator. | |
303 | */ | |
304 | #define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1) | |
305 | struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; | |
306 | #define CACHE_CACHE 0 | |
307 | #define SIZE_AC 1 | |
308 | #define SIZE_L3 (1 + MAX_NUMNODES) | |
309 | ||
310 | /* | |
7243cc05 | 311 | * This function must be completely optimized away if |
e498be7d CL |
312 | * a constant is passed to it. Mostly the same as |
313 | * what is in linux/slab.h except it returns an | |
314 | * index. | |
315 | */ | |
7243cc05 | 316 | static __always_inline int index_of(const size_t size) |
e498be7d CL |
317 | { |
318 | if (__builtin_constant_p(size)) { | |
319 | int i = 0; | |
320 | ||
321 | #define CACHE(x) \ | |
322 | if (size <=x) \ | |
323 | return i; \ | |
324 | else \ | |
325 | i++; | |
326 | #include "linux/kmalloc_sizes.h" | |
327 | #undef CACHE | |
328 | { | |
329 | extern void __bad_size(void); | |
330 | __bad_size(); | |
331 | } | |
7243cc05 IK |
332 | } else |
333 | BUG(); | |
e498be7d CL |
334 | return 0; |
335 | } | |
336 | ||
337 | #define INDEX_AC index_of(sizeof(struct arraycache_init)) | |
338 | #define INDEX_L3 index_of(sizeof(struct kmem_list3)) | |
1da177e4 | 339 | |
e498be7d CL |
340 | static inline void kmem_list3_init(struct kmem_list3 *parent) |
341 | { | |
342 | INIT_LIST_HEAD(&parent->slabs_full); | |
343 | INIT_LIST_HEAD(&parent->slabs_partial); | |
344 | INIT_LIST_HEAD(&parent->slabs_free); | |
345 | parent->shared = NULL; | |
346 | parent->alien = NULL; | |
347 | spin_lock_init(&parent->list_lock); | |
348 | parent->free_objects = 0; | |
349 | parent->free_touched = 0; | |
350 | } | |
351 | ||
352 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ | |
353 | do { \ | |
354 | INIT_LIST_HEAD(listp); \ | |
355 | list_splice(&(cachep->nodelists[nodeid]->slab), listp); \ | |
356 | } while (0) | |
357 | ||
358 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ | |
359 | do { \ | |
360 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ | |
361 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ | |
362 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ | |
363 | } while (0) | |
1da177e4 LT |
364 | |
365 | /* | |
366 | * kmem_cache_t | |
367 | * | |
368 | * manages a cache. | |
369 | */ | |
370 | ||
2109a2d1 | 371 | struct kmem_cache { |
1da177e4 LT |
372 | /* 1) per-cpu data, touched during every alloc/free */ |
373 | struct array_cache *array[NR_CPUS]; | |
374 | unsigned int batchcount; | |
375 | unsigned int limit; | |
e498be7d | 376 | unsigned int shared; |
1da177e4 | 377 | unsigned int objsize; |
e498be7d CL |
378 | /* 2) touched by every alloc & free from the backend */ |
379 | struct kmem_list3 *nodelists[MAX_NUMNODES]; | |
1da177e4 LT |
380 | unsigned int flags; /* constant flags */ |
381 | unsigned int num; /* # of objs per slab */ | |
1da177e4 LT |
382 | spinlock_t spinlock; |
383 | ||
384 | /* 3) cache_grow/shrink */ | |
385 | /* order of pgs per slab (2^n) */ | |
386 | unsigned int gfporder; | |
387 | ||
388 | /* force GFP flags, e.g. GFP_DMA */ | |
6daa0e28 | 389 | gfp_t gfpflags; |
1da177e4 LT |
390 | |
391 | size_t colour; /* cache colouring range */ | |
392 | unsigned int colour_off; /* colour offset */ | |
393 | unsigned int colour_next; /* cache colouring */ | |
394 | kmem_cache_t *slabp_cache; | |
395 | unsigned int slab_size; | |
396 | unsigned int dflags; /* dynamic flags */ | |
397 | ||
398 | /* constructor func */ | |
399 | void (*ctor)(void *, kmem_cache_t *, unsigned long); | |
400 | ||
401 | /* de-constructor func */ | |
402 | void (*dtor)(void *, kmem_cache_t *, unsigned long); | |
403 | ||
404 | /* 4) cache creation/removal */ | |
405 | const char *name; | |
406 | struct list_head next; | |
407 | ||
408 | /* 5) statistics */ | |
409 | #if STATS | |
410 | unsigned long num_active; | |
411 | unsigned long num_allocations; | |
412 | unsigned long high_mark; | |
413 | unsigned long grown; | |
414 | unsigned long reaped; | |
415 | unsigned long errors; | |
416 | unsigned long max_freeable; | |
417 | unsigned long node_allocs; | |
e498be7d | 418 | unsigned long node_frees; |
1da177e4 LT |
419 | atomic_t allochit; |
420 | atomic_t allocmiss; | |
421 | atomic_t freehit; | |
422 | atomic_t freemiss; | |
423 | #endif | |
424 | #if DEBUG | |
425 | int dbghead; | |
426 | int reallen; | |
427 | #endif | |
428 | }; | |
429 | ||
430 | #define CFLGS_OFF_SLAB (0x80000000UL) | |
431 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) | |
432 | ||
433 | #define BATCHREFILL_LIMIT 16 | |
434 | /* Optimization question: fewer reaps means less | |
435 | * probability for unnessary cpucache drain/refill cycles. | |
436 | * | |
dc6f3f27 | 437 | * OTOH the cpuarrays can contain lots of objects, |
1da177e4 LT |
438 | * which could lock up otherwise freeable slabs. |
439 | */ | |
440 | #define REAPTIMEOUT_CPUC (2*HZ) | |
441 | #define REAPTIMEOUT_LIST3 (4*HZ) | |
442 | ||
443 | #if STATS | |
444 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) | |
445 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) | |
446 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) | |
447 | #define STATS_INC_GROWN(x) ((x)->grown++) | |
448 | #define STATS_INC_REAPED(x) ((x)->reaped++) | |
449 | #define STATS_SET_HIGH(x) do { if ((x)->num_active > (x)->high_mark) \ | |
450 | (x)->high_mark = (x)->num_active; \ | |
451 | } while (0) | |
452 | #define STATS_INC_ERR(x) ((x)->errors++) | |
453 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) | |
e498be7d | 454 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
1da177e4 LT |
455 | #define STATS_SET_FREEABLE(x, i) \ |
456 | do { if ((x)->max_freeable < i) \ | |
457 | (x)->max_freeable = i; \ | |
458 | } while (0) | |
459 | ||
460 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) | |
461 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) | |
462 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) | |
463 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) | |
464 | #else | |
465 | #define STATS_INC_ACTIVE(x) do { } while (0) | |
466 | #define STATS_DEC_ACTIVE(x) do { } while (0) | |
467 | #define STATS_INC_ALLOCED(x) do { } while (0) | |
468 | #define STATS_INC_GROWN(x) do { } while (0) | |
469 | #define STATS_INC_REAPED(x) do { } while (0) | |
470 | #define STATS_SET_HIGH(x) do { } while (0) | |
471 | #define STATS_INC_ERR(x) do { } while (0) | |
472 | #define STATS_INC_NODEALLOCS(x) do { } while (0) | |
e498be7d | 473 | #define STATS_INC_NODEFREES(x) do { } while (0) |
1da177e4 LT |
474 | #define STATS_SET_FREEABLE(x, i) \ |
475 | do { } while (0) | |
476 | ||
477 | #define STATS_INC_ALLOCHIT(x) do { } while (0) | |
478 | #define STATS_INC_ALLOCMISS(x) do { } while (0) | |
479 | #define STATS_INC_FREEHIT(x) do { } while (0) | |
480 | #define STATS_INC_FREEMISS(x) do { } while (0) | |
481 | #endif | |
482 | ||
483 | #if DEBUG | |
484 | /* Magic nums for obj red zoning. | |
485 | * Placed in the first word before and the first word after an obj. | |
486 | */ | |
487 | #define RED_INACTIVE 0x5A2CF071UL /* when obj is inactive */ | |
488 | #define RED_ACTIVE 0x170FC2A5UL /* when obj is active */ | |
489 | ||
490 | /* ...and for poisoning */ | |
491 | #define POISON_INUSE 0x5a /* for use-uninitialised poisoning */ | |
492 | #define POISON_FREE 0x6b /* for use-after-free poisoning */ | |
493 | #define POISON_END 0xa5 /* end-byte of poisoning */ | |
494 | ||
495 | /* memory layout of objects: | |
496 | * 0 : objp | |
497 | * 0 .. cachep->dbghead - BYTES_PER_WORD - 1: padding. This ensures that | |
498 | * the end of an object is aligned with the end of the real | |
499 | * allocation. Catches writes behind the end of the allocation. | |
500 | * cachep->dbghead - BYTES_PER_WORD .. cachep->dbghead - 1: | |
501 | * redzone word. | |
502 | * cachep->dbghead: The real object. | |
503 | * cachep->objsize - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] | |
504 | * cachep->objsize - 1* BYTES_PER_WORD: last caller address [BYTES_PER_WORD long] | |
505 | */ | |
506 | static int obj_dbghead(kmem_cache_t *cachep) | |
507 | { | |
508 | return cachep->dbghead; | |
509 | } | |
510 | ||
511 | static int obj_reallen(kmem_cache_t *cachep) | |
512 | { | |
513 | return cachep->reallen; | |
514 | } | |
515 | ||
516 | static unsigned long *dbg_redzone1(kmem_cache_t *cachep, void *objp) | |
517 | { | |
518 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
519 | return (unsigned long*) (objp+obj_dbghead(cachep)-BYTES_PER_WORD); | |
520 | } | |
521 | ||
522 | static unsigned long *dbg_redzone2(kmem_cache_t *cachep, void *objp) | |
523 | { | |
524 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
525 | if (cachep->flags & SLAB_STORE_USER) | |
526 | return (unsigned long*) (objp+cachep->objsize-2*BYTES_PER_WORD); | |
527 | return (unsigned long*) (objp+cachep->objsize-BYTES_PER_WORD); | |
528 | } | |
529 | ||
530 | static void **dbg_userword(kmem_cache_t *cachep, void *objp) | |
531 | { | |
532 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); | |
533 | return (void**)(objp+cachep->objsize-BYTES_PER_WORD); | |
534 | } | |
535 | ||
536 | #else | |
537 | ||
538 | #define obj_dbghead(x) 0 | |
539 | #define obj_reallen(cachep) (cachep->objsize) | |
540 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long *)NULL;}) | |
541 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long *)NULL;}) | |
542 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) | |
543 | ||
544 | #endif | |
545 | ||
546 | /* | |
547 | * Maximum size of an obj (in 2^order pages) | |
548 | * and absolute limit for the gfp order. | |
549 | */ | |
550 | #if defined(CONFIG_LARGE_ALLOCS) | |
551 | #define MAX_OBJ_ORDER 13 /* up to 32Mb */ | |
552 | #define MAX_GFP_ORDER 13 /* up to 32Mb */ | |
553 | #elif defined(CONFIG_MMU) | |
554 | #define MAX_OBJ_ORDER 5 /* 32 pages */ | |
555 | #define MAX_GFP_ORDER 5 /* 32 pages */ | |
556 | #else | |
557 | #define MAX_OBJ_ORDER 8 /* up to 1Mb */ | |
558 | #define MAX_GFP_ORDER 8 /* up to 1Mb */ | |
559 | #endif | |
560 | ||
561 | /* | |
562 | * Do not go above this order unless 0 objects fit into the slab. | |
563 | */ | |
564 | #define BREAK_GFP_ORDER_HI 1 | |
565 | #define BREAK_GFP_ORDER_LO 0 | |
566 | static int slab_break_gfp_order = BREAK_GFP_ORDER_LO; | |
567 | ||
065d41cb | 568 | /* Functions for storing/retrieving the cachep and or slab from the |
1da177e4 LT |
569 | * global 'mem_map'. These are used to find the slab an obj belongs to. |
570 | * With kfree(), these are used to find the cache which an obj belongs to. | |
571 | */ | |
065d41cb PE |
572 | static inline void page_set_cache(struct page *page, struct kmem_cache *cache) |
573 | { | |
574 | page->lru.next = (struct list_head *)cache; | |
575 | } | |
576 | ||
577 | static inline struct kmem_cache *page_get_cache(struct page *page) | |
578 | { | |
579 | return (struct kmem_cache *)page->lru.next; | |
580 | } | |
581 | ||
582 | static inline void page_set_slab(struct page *page, struct slab *slab) | |
583 | { | |
584 | page->lru.prev = (struct list_head *)slab; | |
585 | } | |
586 | ||
587 | static inline struct slab *page_get_slab(struct page *page) | |
588 | { | |
589 | return (struct slab *)page->lru.prev; | |
590 | } | |
1da177e4 LT |
591 | |
592 | /* These are the default caches for kmalloc. Custom caches can have other sizes. */ | |
593 | struct cache_sizes malloc_sizes[] = { | |
594 | #define CACHE(x) { .cs_size = (x) }, | |
595 | #include <linux/kmalloc_sizes.h> | |
596 | CACHE(ULONG_MAX) | |
597 | #undef CACHE | |
598 | }; | |
599 | EXPORT_SYMBOL(malloc_sizes); | |
600 | ||
601 | /* Must match cache_sizes above. Out of line to keep cache footprint low. */ | |
602 | struct cache_names { | |
603 | char *name; | |
604 | char *name_dma; | |
605 | }; | |
606 | ||
607 | static struct cache_names __initdata cache_names[] = { | |
608 | #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" }, | |
609 | #include <linux/kmalloc_sizes.h> | |
610 | { NULL, } | |
611 | #undef CACHE | |
612 | }; | |
613 | ||
614 | static struct arraycache_init initarray_cache __initdata = | |
615 | { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; | |
616 | static struct arraycache_init initarray_generic = | |
617 | { { 0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; | |
618 | ||
619 | /* internal cache of cache description objs */ | |
620 | static kmem_cache_t cache_cache = { | |
1da177e4 LT |
621 | .batchcount = 1, |
622 | .limit = BOOT_CPUCACHE_ENTRIES, | |
e498be7d | 623 | .shared = 1, |
1da177e4 LT |
624 | .objsize = sizeof(kmem_cache_t), |
625 | .flags = SLAB_NO_REAP, | |
626 | .spinlock = SPIN_LOCK_UNLOCKED, | |
627 | .name = "kmem_cache", | |
628 | #if DEBUG | |
629 | .reallen = sizeof(kmem_cache_t), | |
630 | #endif | |
631 | }; | |
632 | ||
633 | /* Guard access to the cache-chain. */ | |
634 | static struct semaphore cache_chain_sem; | |
635 | static struct list_head cache_chain; | |
636 | ||
637 | /* | |
638 | * vm_enough_memory() looks at this to determine how many | |
639 | * slab-allocated pages are possibly freeable under pressure | |
640 | * | |
641 | * SLAB_RECLAIM_ACCOUNT turns this on per-slab | |
642 | */ | |
643 | atomic_t slab_reclaim_pages; | |
1da177e4 LT |
644 | |
645 | /* | |
646 | * chicken and egg problem: delay the per-cpu array allocation | |
647 | * until the general caches are up. | |
648 | */ | |
649 | static enum { | |
650 | NONE, | |
e498be7d CL |
651 | PARTIAL_AC, |
652 | PARTIAL_L3, | |
1da177e4 LT |
653 | FULL |
654 | } g_cpucache_up; | |
655 | ||
656 | static DEFINE_PER_CPU(struct work_struct, reap_work); | |
657 | ||
ff69416e | 658 | static void free_block(kmem_cache_t* cachep, void** objpp, int len, int node); |
1da177e4 LT |
659 | static void enable_cpucache (kmem_cache_t *cachep); |
660 | static void cache_reap (void *unused); | |
e498be7d | 661 | static int __node_shrink(kmem_cache_t *cachep, int node); |
1da177e4 LT |
662 | |
663 | static inline struct array_cache *ac_data(kmem_cache_t *cachep) | |
664 | { | |
665 | return cachep->array[smp_processor_id()]; | |
666 | } | |
667 | ||
dd0fc66f | 668 | static inline kmem_cache_t *__find_general_cachep(size_t size, gfp_t gfpflags) |
1da177e4 LT |
669 | { |
670 | struct cache_sizes *csizep = malloc_sizes; | |
671 | ||
672 | #if DEBUG | |
673 | /* This happens if someone tries to call | |
674 | * kmem_cache_create(), or __kmalloc(), before | |
675 | * the generic caches are initialized. | |
676 | */ | |
c7e43c78 | 677 | BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); |
1da177e4 LT |
678 | #endif |
679 | while (size > csizep->cs_size) | |
680 | csizep++; | |
681 | ||
682 | /* | |
0abf40c1 | 683 | * Really subtle: The last entry with cs->cs_size==ULONG_MAX |
1da177e4 LT |
684 | * has cs_{dma,}cachep==NULL. Thus no special case |
685 | * for large kmalloc calls required. | |
686 | */ | |
687 | if (unlikely(gfpflags & GFP_DMA)) | |
688 | return csizep->cs_dmacachep; | |
689 | return csizep->cs_cachep; | |
690 | } | |
691 | ||
dd0fc66f | 692 | kmem_cache_t *kmem_find_general_cachep(size_t size, gfp_t gfpflags) |
97e2bde4 MS |
693 | { |
694 | return __find_general_cachep(size, gfpflags); | |
695 | } | |
696 | EXPORT_SYMBOL(kmem_find_general_cachep); | |
697 | ||
1da177e4 LT |
698 | /* Cal the num objs, wastage, and bytes left over for a given slab size. */ |
699 | static void cache_estimate(unsigned long gfporder, size_t size, size_t align, | |
700 | int flags, size_t *left_over, unsigned int *num) | |
701 | { | |
702 | int i; | |
703 | size_t wastage = PAGE_SIZE<<gfporder; | |
704 | size_t extra = 0; | |
705 | size_t base = 0; | |
706 | ||
707 | if (!(flags & CFLGS_OFF_SLAB)) { | |
708 | base = sizeof(struct slab); | |
709 | extra = sizeof(kmem_bufctl_t); | |
710 | } | |
711 | i = 0; | |
712 | while (i*size + ALIGN(base+i*extra, align) <= wastage) | |
713 | i++; | |
714 | if (i > 0) | |
715 | i--; | |
716 | ||
717 | if (i > SLAB_LIMIT) | |
718 | i = SLAB_LIMIT; | |
719 | ||
720 | *num = i; | |
721 | wastage -= i*size; | |
722 | wastage -= ALIGN(base+i*extra, align); | |
723 | *left_over = wastage; | |
724 | } | |
725 | ||
726 | #define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg) | |
727 | ||
728 | static void __slab_error(const char *function, kmem_cache_t *cachep, char *msg) | |
729 | { | |
730 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", | |
731 | function, cachep->name, msg); | |
732 | dump_stack(); | |
733 | } | |
734 | ||
735 | /* | |
736 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz | |
737 | * via the workqueue/eventd. | |
738 | * Add the CPU number into the expiration time to minimize the possibility of | |
739 | * the CPUs getting into lockstep and contending for the global cache chain | |
740 | * lock. | |
741 | */ | |
742 | static void __devinit start_cpu_timer(int cpu) | |
743 | { | |
744 | struct work_struct *reap_work = &per_cpu(reap_work, cpu); | |
745 | ||
746 | /* | |
747 | * When this gets called from do_initcalls via cpucache_init(), | |
748 | * init_workqueues() has already run, so keventd will be setup | |
749 | * at that time. | |
750 | */ | |
751 | if (keventd_up() && reap_work->func == NULL) { | |
752 | INIT_WORK(reap_work, cache_reap, NULL); | |
753 | schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu); | |
754 | } | |
755 | } | |
756 | ||
e498be7d | 757 | static struct array_cache *alloc_arraycache(int node, int entries, |
1da177e4 LT |
758 | int batchcount) |
759 | { | |
760 | int memsize = sizeof(void*)*entries+sizeof(struct array_cache); | |
761 | struct array_cache *nc = NULL; | |
762 | ||
e498be7d | 763 | nc = kmalloc_node(memsize, GFP_KERNEL, node); |
1da177e4 LT |
764 | if (nc) { |
765 | nc->avail = 0; | |
766 | nc->limit = entries; | |
767 | nc->batchcount = batchcount; | |
768 | nc->touched = 0; | |
e498be7d | 769 | spin_lock_init(&nc->lock); |
1da177e4 LT |
770 | } |
771 | return nc; | |
772 | } | |
773 | ||
e498be7d CL |
774 | #ifdef CONFIG_NUMA |
775 | static inline struct array_cache **alloc_alien_cache(int node, int limit) | |
776 | { | |
777 | struct array_cache **ac_ptr; | |
778 | int memsize = sizeof(void*)*MAX_NUMNODES; | |
779 | int i; | |
780 | ||
781 | if (limit > 1) | |
782 | limit = 12; | |
783 | ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node); | |
784 | if (ac_ptr) { | |
785 | for_each_node(i) { | |
786 | if (i == node || !node_online(i)) { | |
787 | ac_ptr[i] = NULL; | |
788 | continue; | |
789 | } | |
790 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d); | |
791 | if (!ac_ptr[i]) { | |
792 | for (i--; i <=0; i--) | |
793 | kfree(ac_ptr[i]); | |
794 | kfree(ac_ptr); | |
795 | return NULL; | |
796 | } | |
797 | } | |
798 | } | |
799 | return ac_ptr; | |
800 | } | |
801 | ||
802 | static inline void free_alien_cache(struct array_cache **ac_ptr) | |
803 | { | |
804 | int i; | |
805 | ||
806 | if (!ac_ptr) | |
807 | return; | |
808 | ||
809 | for_each_node(i) | |
810 | kfree(ac_ptr[i]); | |
811 | ||
812 | kfree(ac_ptr); | |
813 | } | |
814 | ||
815 | static inline void __drain_alien_cache(kmem_cache_t *cachep, struct array_cache *ac, int node) | |
816 | { | |
817 | struct kmem_list3 *rl3 = cachep->nodelists[node]; | |
818 | ||
819 | if (ac->avail) { | |
820 | spin_lock(&rl3->list_lock); | |
ff69416e | 821 | free_block(cachep, ac->entry, ac->avail, node); |
e498be7d CL |
822 | ac->avail = 0; |
823 | spin_unlock(&rl3->list_lock); | |
824 | } | |
825 | } | |
826 | ||
827 | static void drain_alien_cache(kmem_cache_t *cachep, struct kmem_list3 *l3) | |
828 | { | |
829 | int i=0; | |
830 | struct array_cache *ac; | |
831 | unsigned long flags; | |
832 | ||
833 | for_each_online_node(i) { | |
834 | ac = l3->alien[i]; | |
835 | if (ac) { | |
836 | spin_lock_irqsave(&ac->lock, flags); | |
837 | __drain_alien_cache(cachep, ac, i); | |
838 | spin_unlock_irqrestore(&ac->lock, flags); | |
839 | } | |
840 | } | |
841 | } | |
842 | #else | |
843 | #define alloc_alien_cache(node, limit) do { } while (0) | |
844 | #define free_alien_cache(ac_ptr) do { } while (0) | |
845 | #define drain_alien_cache(cachep, l3) do { } while (0) | |
846 | #endif | |
847 | ||
1da177e4 LT |
848 | static int __devinit cpuup_callback(struct notifier_block *nfb, |
849 | unsigned long action, void *hcpu) | |
850 | { | |
851 | long cpu = (long)hcpu; | |
852 | kmem_cache_t* cachep; | |
e498be7d CL |
853 | struct kmem_list3 *l3 = NULL; |
854 | int node = cpu_to_node(cpu); | |
855 | int memsize = sizeof(struct kmem_list3); | |
856 | struct array_cache *nc = NULL; | |
1da177e4 LT |
857 | |
858 | switch (action) { | |
859 | case CPU_UP_PREPARE: | |
860 | down(&cache_chain_sem); | |
e498be7d CL |
861 | /* we need to do this right in the beginning since |
862 | * alloc_arraycache's are going to use this list. | |
863 | * kmalloc_node allows us to add the slab to the right | |
864 | * kmem_list3 and not this cpu's kmem_list3 | |
865 | */ | |
866 | ||
1da177e4 | 867 | list_for_each_entry(cachep, &cache_chain, next) { |
e498be7d CL |
868 | /* setup the size64 kmemlist for cpu before we can |
869 | * begin anything. Make sure some other cpu on this | |
870 | * node has not already allocated this | |
871 | */ | |
872 | if (!cachep->nodelists[node]) { | |
873 | if (!(l3 = kmalloc_node(memsize, | |
874 | GFP_KERNEL, node))) | |
875 | goto bad; | |
876 | kmem_list3_init(l3); | |
877 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + | |
878 | ((unsigned long)cachep)%REAPTIMEOUT_LIST3; | |
879 | ||
880 | cachep->nodelists[node] = l3; | |
881 | } | |
1da177e4 | 882 | |
e498be7d CL |
883 | spin_lock_irq(&cachep->nodelists[node]->list_lock); |
884 | cachep->nodelists[node]->free_limit = | |
885 | (1 + nr_cpus_node(node)) * | |
886 | cachep->batchcount + cachep->num; | |
887 | spin_unlock_irq(&cachep->nodelists[node]->list_lock); | |
888 | } | |
889 | ||
890 | /* Now we can go ahead with allocating the shared array's | |
891 | & array cache's */ | |
892 | list_for_each_entry(cachep, &cache_chain, next) { | |
893 | nc = alloc_arraycache(node, cachep->limit, | |
894 | cachep->batchcount); | |
1da177e4 LT |
895 | if (!nc) |
896 | goto bad; | |
1da177e4 | 897 | cachep->array[cpu] = nc; |
1da177e4 | 898 | |
e498be7d CL |
899 | l3 = cachep->nodelists[node]; |
900 | BUG_ON(!l3); | |
901 | if (!l3->shared) { | |
902 | if (!(nc = alloc_arraycache(node, | |
903 | cachep->shared*cachep->batchcount, | |
904 | 0xbaadf00d))) | |
905 | goto bad; | |
906 | ||
907 | /* we are serialised from CPU_DEAD or | |
908 | CPU_UP_CANCELLED by the cpucontrol lock */ | |
909 | l3->shared = nc; | |
910 | } | |
1da177e4 LT |
911 | } |
912 | up(&cache_chain_sem); | |
913 | break; | |
914 | case CPU_ONLINE: | |
915 | start_cpu_timer(cpu); | |
916 | break; | |
917 | #ifdef CONFIG_HOTPLUG_CPU | |
918 | case CPU_DEAD: | |
919 | /* fall thru */ | |
920 | case CPU_UP_CANCELED: | |
921 | down(&cache_chain_sem); | |
922 | ||
923 | list_for_each_entry(cachep, &cache_chain, next) { | |
924 | struct array_cache *nc; | |
e498be7d | 925 | cpumask_t mask; |
1da177e4 | 926 | |
e498be7d | 927 | mask = node_to_cpumask(node); |
1da177e4 LT |
928 | spin_lock_irq(&cachep->spinlock); |
929 | /* cpu is dead; no one can alloc from it. */ | |
930 | nc = cachep->array[cpu]; | |
931 | cachep->array[cpu] = NULL; | |
e498be7d CL |
932 | l3 = cachep->nodelists[node]; |
933 | ||
934 | if (!l3) | |
935 | goto unlock_cache; | |
936 | ||
937 | spin_lock(&l3->list_lock); | |
938 | ||
939 | /* Free limit for this kmem_list3 */ | |
940 | l3->free_limit -= cachep->batchcount; | |
941 | if (nc) | |
ff69416e | 942 | free_block(cachep, nc->entry, nc->avail, node); |
e498be7d CL |
943 | |
944 | if (!cpus_empty(mask)) { | |
945 | spin_unlock(&l3->list_lock); | |
946 | goto unlock_cache; | |
947 | } | |
948 | ||
949 | if (l3->shared) { | |
950 | free_block(cachep, l3->shared->entry, | |
ff69416e | 951 | l3->shared->avail, node); |
e498be7d CL |
952 | kfree(l3->shared); |
953 | l3->shared = NULL; | |
954 | } | |
955 | if (l3->alien) { | |
956 | drain_alien_cache(cachep, l3); | |
957 | free_alien_cache(l3->alien); | |
958 | l3->alien = NULL; | |
959 | } | |
960 | ||
961 | /* free slabs belonging to this node */ | |
962 | if (__node_shrink(cachep, node)) { | |
963 | cachep->nodelists[node] = NULL; | |
964 | spin_unlock(&l3->list_lock); | |
965 | kfree(l3); | |
966 | } else { | |
967 | spin_unlock(&l3->list_lock); | |
968 | } | |
969 | unlock_cache: | |
1da177e4 LT |
970 | spin_unlock_irq(&cachep->spinlock); |
971 | kfree(nc); | |
972 | } | |
973 | up(&cache_chain_sem); | |
974 | break; | |
975 | #endif | |
976 | } | |
977 | return NOTIFY_OK; | |
978 | bad: | |
979 | up(&cache_chain_sem); | |
980 | return NOTIFY_BAD; | |
981 | } | |
982 | ||
983 | static struct notifier_block cpucache_notifier = { &cpuup_callback, NULL, 0 }; | |
984 | ||
e498be7d CL |
985 | /* |
986 | * swap the static kmem_list3 with kmalloced memory | |
987 | */ | |
988 | static void init_list(kmem_cache_t *cachep, struct kmem_list3 *list, | |
989 | int nodeid) | |
990 | { | |
991 | struct kmem_list3 *ptr; | |
992 | ||
993 | BUG_ON(cachep->nodelists[nodeid] != list); | |
994 | ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid); | |
995 | BUG_ON(!ptr); | |
996 | ||
997 | local_irq_disable(); | |
998 | memcpy(ptr, list, sizeof(struct kmem_list3)); | |
999 | MAKE_ALL_LISTS(cachep, ptr, nodeid); | |
1000 | cachep->nodelists[nodeid] = ptr; | |
1001 | local_irq_enable(); | |
1002 | } | |
1003 | ||
1da177e4 LT |
1004 | /* Initialisation. |
1005 | * Called after the gfp() functions have been enabled, and before smp_init(). | |
1006 | */ | |
1007 | void __init kmem_cache_init(void) | |
1008 | { | |
1009 | size_t left_over; | |
1010 | struct cache_sizes *sizes; | |
1011 | struct cache_names *names; | |
e498be7d CL |
1012 | int i; |
1013 | ||
1014 | for (i = 0; i < NUM_INIT_LISTS; i++) { | |
1015 | kmem_list3_init(&initkmem_list3[i]); | |
1016 | if (i < MAX_NUMNODES) | |
1017 | cache_cache.nodelists[i] = NULL; | |
1018 | } | |
1da177e4 LT |
1019 | |
1020 | /* | |
1021 | * Fragmentation resistance on low memory - only use bigger | |
1022 | * page orders on machines with more than 32MB of memory. | |
1023 | */ | |
1024 | if (num_physpages > (32 << 20) >> PAGE_SHIFT) | |
1025 | slab_break_gfp_order = BREAK_GFP_ORDER_HI; | |
1026 | ||
1da177e4 LT |
1027 | /* Bootstrap is tricky, because several objects are allocated |
1028 | * from caches that do not exist yet: | |
1029 | * 1) initialize the cache_cache cache: it contains the kmem_cache_t | |
1030 | * structures of all caches, except cache_cache itself: cache_cache | |
1031 | * is statically allocated. | |
e498be7d CL |
1032 | * Initially an __init data area is used for the head array and the |
1033 | * kmem_list3 structures, it's replaced with a kmalloc allocated | |
1034 | * array at the end of the bootstrap. | |
1da177e4 | 1035 | * 2) Create the first kmalloc cache. |
e498be7d CL |
1036 | * The kmem_cache_t for the new cache is allocated normally. |
1037 | * An __init data area is used for the head array. | |
1038 | * 3) Create the remaining kmalloc caches, with minimally sized | |
1039 | * head arrays. | |
1da177e4 LT |
1040 | * 4) Replace the __init data head arrays for cache_cache and the first |
1041 | * kmalloc cache with kmalloc allocated arrays. | |
e498be7d CL |
1042 | * 5) Replace the __init data for kmem_list3 for cache_cache and |
1043 | * the other cache's with kmalloc allocated memory. | |
1044 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. | |
1da177e4 LT |
1045 | */ |
1046 | ||
1047 | /* 1) create the cache_cache */ | |
1048 | init_MUTEX(&cache_chain_sem); | |
1049 | INIT_LIST_HEAD(&cache_chain); | |
1050 | list_add(&cache_cache.next, &cache_chain); | |
1051 | cache_cache.colour_off = cache_line_size(); | |
1052 | cache_cache.array[smp_processor_id()] = &initarray_cache.cache; | |
e498be7d | 1053 | cache_cache.nodelists[numa_node_id()] = &initkmem_list3[CACHE_CACHE]; |
1da177e4 LT |
1054 | |
1055 | cache_cache.objsize = ALIGN(cache_cache.objsize, cache_line_size()); | |
1056 | ||
1057 | cache_estimate(0, cache_cache.objsize, cache_line_size(), 0, | |
1058 | &left_over, &cache_cache.num); | |
1059 | if (!cache_cache.num) | |
1060 | BUG(); | |
1061 | ||
1062 | cache_cache.colour = left_over/cache_cache.colour_off; | |
1063 | cache_cache.colour_next = 0; | |
1064 | cache_cache.slab_size = ALIGN(cache_cache.num*sizeof(kmem_bufctl_t) + | |
1065 | sizeof(struct slab), cache_line_size()); | |
1066 | ||
1067 | /* 2+3) create the kmalloc caches */ | |
1068 | sizes = malloc_sizes; | |
1069 | names = cache_names; | |
1070 | ||
e498be7d CL |
1071 | /* Initialize the caches that provide memory for the array cache |
1072 | * and the kmem_list3 structures first. | |
1073 | * Without this, further allocations will bug | |
1074 | */ | |
1075 | ||
1076 | sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name, | |
1077 | sizes[INDEX_AC].cs_size, ARCH_KMALLOC_MINALIGN, | |
1078 | (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL); | |
1079 | ||
1080 | if (INDEX_AC != INDEX_L3) | |
1081 | sizes[INDEX_L3].cs_cachep = | |
1082 | kmem_cache_create(names[INDEX_L3].name, | |
1083 | sizes[INDEX_L3].cs_size, ARCH_KMALLOC_MINALIGN, | |
1084 | (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL); | |
1085 | ||
1da177e4 | 1086 | while (sizes->cs_size != ULONG_MAX) { |
e498be7d CL |
1087 | /* |
1088 | * For performance, all the general caches are L1 aligned. | |
1da177e4 LT |
1089 | * This should be particularly beneficial on SMP boxes, as it |
1090 | * eliminates "false sharing". | |
1091 | * Note for systems short on memory removing the alignment will | |
e498be7d CL |
1092 | * allow tighter packing of the smaller caches. |
1093 | */ | |
1094 | if(!sizes->cs_cachep) | |
1095 | sizes->cs_cachep = kmem_cache_create(names->name, | |
1096 | sizes->cs_size, ARCH_KMALLOC_MINALIGN, | |
1097 | (ARCH_KMALLOC_FLAGS | SLAB_PANIC), NULL, NULL); | |
1da177e4 LT |
1098 | |
1099 | /* Inc off-slab bufctl limit until the ceiling is hit. */ | |
1100 | if (!(OFF_SLAB(sizes->cs_cachep))) { | |
1101 | offslab_limit = sizes->cs_size-sizeof(struct slab); | |
1102 | offslab_limit /= sizeof(kmem_bufctl_t); | |
1103 | } | |
1104 | ||
1105 | sizes->cs_dmacachep = kmem_cache_create(names->name_dma, | |
1106 | sizes->cs_size, ARCH_KMALLOC_MINALIGN, | |
1107 | (ARCH_KMALLOC_FLAGS | SLAB_CACHE_DMA | SLAB_PANIC), | |
1108 | NULL, NULL); | |
1109 | ||
1110 | sizes++; | |
1111 | names++; | |
1112 | } | |
1113 | /* 4) Replace the bootstrap head arrays */ | |
1114 | { | |
1115 | void * ptr; | |
e498be7d | 1116 | |
1da177e4 | 1117 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); |
e498be7d | 1118 | |
1da177e4 LT |
1119 | local_irq_disable(); |
1120 | BUG_ON(ac_data(&cache_cache) != &initarray_cache.cache); | |
e498be7d CL |
1121 | memcpy(ptr, ac_data(&cache_cache), |
1122 | sizeof(struct arraycache_init)); | |
1da177e4 LT |
1123 | cache_cache.array[smp_processor_id()] = ptr; |
1124 | local_irq_enable(); | |
e498be7d | 1125 | |
1da177e4 | 1126 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); |
e498be7d | 1127 | |
1da177e4 | 1128 | local_irq_disable(); |
e498be7d CL |
1129 | BUG_ON(ac_data(malloc_sizes[INDEX_AC].cs_cachep) |
1130 | != &initarray_generic.cache); | |
1131 | memcpy(ptr, ac_data(malloc_sizes[INDEX_AC].cs_cachep), | |
1da177e4 | 1132 | sizeof(struct arraycache_init)); |
e498be7d CL |
1133 | malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = |
1134 | ptr; | |
1da177e4 LT |
1135 | local_irq_enable(); |
1136 | } | |
e498be7d CL |
1137 | /* 5) Replace the bootstrap kmem_list3's */ |
1138 | { | |
1139 | int node; | |
1140 | /* Replace the static kmem_list3 structures for the boot cpu */ | |
1141 | init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], | |
1142 | numa_node_id()); | |
1143 | ||
1144 | for_each_online_node(node) { | |
1145 | init_list(malloc_sizes[INDEX_AC].cs_cachep, | |
1146 | &initkmem_list3[SIZE_AC+node], node); | |
1147 | ||
1148 | if (INDEX_AC != INDEX_L3) { | |
1149 | init_list(malloc_sizes[INDEX_L3].cs_cachep, | |
1150 | &initkmem_list3[SIZE_L3+node], | |
1151 | node); | |
1152 | } | |
1153 | } | |
1154 | } | |
1da177e4 | 1155 | |
e498be7d | 1156 | /* 6) resize the head arrays to their final sizes */ |
1da177e4 LT |
1157 | { |
1158 | kmem_cache_t *cachep; | |
1159 | down(&cache_chain_sem); | |
1160 | list_for_each_entry(cachep, &cache_chain, next) | |
1161 | enable_cpucache(cachep); | |
1162 | up(&cache_chain_sem); | |
1163 | } | |
1164 | ||
1165 | /* Done! */ | |
1166 | g_cpucache_up = FULL; | |
1167 | ||
1168 | /* Register a cpu startup notifier callback | |
1169 | * that initializes ac_data for all new cpus | |
1170 | */ | |
1171 | register_cpu_notifier(&cpucache_notifier); | |
1da177e4 LT |
1172 | |
1173 | /* The reap timers are started later, with a module init call: | |
1174 | * That part of the kernel is not yet operational. | |
1175 | */ | |
1176 | } | |
1177 | ||
1178 | static int __init cpucache_init(void) | |
1179 | { | |
1180 | int cpu; | |
1181 | ||
1182 | /* | |
1183 | * Register the timers that return unneeded | |
1184 | * pages to gfp. | |
1185 | */ | |
e498be7d CL |
1186 | for_each_online_cpu(cpu) |
1187 | start_cpu_timer(cpu); | |
1da177e4 LT |
1188 | |
1189 | return 0; | |
1190 | } | |
1191 | ||
1192 | __initcall(cpucache_init); | |
1193 | ||
1194 | /* | |
1195 | * Interface to system's page allocator. No need to hold the cache-lock. | |
1196 | * | |
1197 | * If we requested dmaable memory, we will get it. Even if we | |
1198 | * did not request dmaable memory, we might get it, but that | |
1199 | * would be relatively rare and ignorable. | |
1200 | */ | |
dd0fc66f | 1201 | static void *kmem_getpages(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
1da177e4 LT |
1202 | { |
1203 | struct page *page; | |
1204 | void *addr; | |
1205 | int i; | |
1206 | ||
1207 | flags |= cachep->gfpflags; | |
50c85a19 | 1208 | page = alloc_pages_node(nodeid, flags, cachep->gfporder); |
1da177e4 LT |
1209 | if (!page) |
1210 | return NULL; | |
1211 | addr = page_address(page); | |
1212 | ||
1213 | i = (1 << cachep->gfporder); | |
1214 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1215 | atomic_add(i, &slab_reclaim_pages); | |
1216 | add_page_state(nr_slab, i); | |
1217 | while (i--) { | |
1218 | SetPageSlab(page); | |
1219 | page++; | |
1220 | } | |
1221 | return addr; | |
1222 | } | |
1223 | ||
1224 | /* | |
1225 | * Interface to system's page release. | |
1226 | */ | |
1227 | static void kmem_freepages(kmem_cache_t *cachep, void *addr) | |
1228 | { | |
1229 | unsigned long i = (1<<cachep->gfporder); | |
1230 | struct page *page = virt_to_page(addr); | |
1231 | const unsigned long nr_freed = i; | |
1232 | ||
1233 | while (i--) { | |
1234 | if (!TestClearPageSlab(page)) | |
1235 | BUG(); | |
1236 | page++; | |
1237 | } | |
1238 | sub_page_state(nr_slab, nr_freed); | |
1239 | if (current->reclaim_state) | |
1240 | current->reclaim_state->reclaimed_slab += nr_freed; | |
1241 | free_pages((unsigned long)addr, cachep->gfporder); | |
1242 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1243 | atomic_sub(1<<cachep->gfporder, &slab_reclaim_pages); | |
1244 | } | |
1245 | ||
1246 | static void kmem_rcu_free(struct rcu_head *head) | |
1247 | { | |
1248 | struct slab_rcu *slab_rcu = (struct slab_rcu *) head; | |
1249 | kmem_cache_t *cachep = slab_rcu->cachep; | |
1250 | ||
1251 | kmem_freepages(cachep, slab_rcu->addr); | |
1252 | if (OFF_SLAB(cachep)) | |
1253 | kmem_cache_free(cachep->slabp_cache, slab_rcu); | |
1254 | } | |
1255 | ||
1256 | #if DEBUG | |
1257 | ||
1258 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1259 | static void store_stackinfo(kmem_cache_t *cachep, unsigned long *addr, | |
1260 | unsigned long caller) | |
1261 | { | |
1262 | int size = obj_reallen(cachep); | |
1263 | ||
1264 | addr = (unsigned long *)&((char*)addr)[obj_dbghead(cachep)]; | |
1265 | ||
1266 | if (size < 5*sizeof(unsigned long)) | |
1267 | return; | |
1268 | ||
1269 | *addr++=0x12345678; | |
1270 | *addr++=caller; | |
1271 | *addr++=smp_processor_id(); | |
1272 | size -= 3*sizeof(unsigned long); | |
1273 | { | |
1274 | unsigned long *sptr = &caller; | |
1275 | unsigned long svalue; | |
1276 | ||
1277 | while (!kstack_end(sptr)) { | |
1278 | svalue = *sptr++; | |
1279 | if (kernel_text_address(svalue)) { | |
1280 | *addr++=svalue; | |
1281 | size -= sizeof(unsigned long); | |
1282 | if (size <= sizeof(unsigned long)) | |
1283 | break; | |
1284 | } | |
1285 | } | |
1286 | ||
1287 | } | |
1288 | *addr++=0x87654321; | |
1289 | } | |
1290 | #endif | |
1291 | ||
1292 | static void poison_obj(kmem_cache_t *cachep, void *addr, unsigned char val) | |
1293 | { | |
1294 | int size = obj_reallen(cachep); | |
1295 | addr = &((char*)addr)[obj_dbghead(cachep)]; | |
1296 | ||
1297 | memset(addr, val, size); | |
1298 | *(unsigned char *)(addr+size-1) = POISON_END; | |
1299 | } | |
1300 | ||
1301 | static void dump_line(char *data, int offset, int limit) | |
1302 | { | |
1303 | int i; | |
1304 | printk(KERN_ERR "%03x:", offset); | |
1305 | for (i=0;i<limit;i++) { | |
1306 | printk(" %02x", (unsigned char)data[offset+i]); | |
1307 | } | |
1308 | printk("\n"); | |
1309 | } | |
1310 | #endif | |
1311 | ||
1312 | #if DEBUG | |
1313 | ||
1314 | static void print_objinfo(kmem_cache_t *cachep, void *objp, int lines) | |
1315 | { | |
1316 | int i, size; | |
1317 | char *realobj; | |
1318 | ||
1319 | if (cachep->flags & SLAB_RED_ZONE) { | |
1320 | printk(KERN_ERR "Redzone: 0x%lx/0x%lx.\n", | |
1321 | *dbg_redzone1(cachep, objp), | |
1322 | *dbg_redzone2(cachep, objp)); | |
1323 | } | |
1324 | ||
1325 | if (cachep->flags & SLAB_STORE_USER) { | |
1326 | printk(KERN_ERR "Last user: [<%p>]", | |
1327 | *dbg_userword(cachep, objp)); | |
1328 | print_symbol("(%s)", | |
1329 | (unsigned long)*dbg_userword(cachep, objp)); | |
1330 | printk("\n"); | |
1331 | } | |
1332 | realobj = (char*)objp+obj_dbghead(cachep); | |
1333 | size = obj_reallen(cachep); | |
1334 | for (i=0; i<size && lines;i+=16, lines--) { | |
1335 | int limit; | |
1336 | limit = 16; | |
1337 | if (i+limit > size) | |
1338 | limit = size-i; | |
1339 | dump_line(realobj, i, limit); | |
1340 | } | |
1341 | } | |
1342 | ||
1343 | static void check_poison_obj(kmem_cache_t *cachep, void *objp) | |
1344 | { | |
1345 | char *realobj; | |
1346 | int size, i; | |
1347 | int lines = 0; | |
1348 | ||
1349 | realobj = (char*)objp+obj_dbghead(cachep); | |
1350 | size = obj_reallen(cachep); | |
1351 | ||
1352 | for (i=0;i<size;i++) { | |
1353 | char exp = POISON_FREE; | |
1354 | if (i == size-1) | |
1355 | exp = POISON_END; | |
1356 | if (realobj[i] != exp) { | |
1357 | int limit; | |
1358 | /* Mismatch ! */ | |
1359 | /* Print header */ | |
1360 | if (lines == 0) { | |
1361 | printk(KERN_ERR "Slab corruption: start=%p, len=%d\n", | |
1362 | realobj, size); | |
1363 | print_objinfo(cachep, objp, 0); | |
1364 | } | |
1365 | /* Hexdump the affected line */ | |
1366 | i = (i/16)*16; | |
1367 | limit = 16; | |
1368 | if (i+limit > size) | |
1369 | limit = size-i; | |
1370 | dump_line(realobj, i, limit); | |
1371 | i += 16; | |
1372 | lines++; | |
1373 | /* Limit to 5 lines */ | |
1374 | if (lines > 5) | |
1375 | break; | |
1376 | } | |
1377 | } | |
1378 | if (lines != 0) { | |
1379 | /* Print some data about the neighboring objects, if they | |
1380 | * exist: | |
1381 | */ | |
065d41cb | 1382 | struct slab *slabp = page_get_slab(virt_to_page(objp)); |
1da177e4 LT |
1383 | int objnr; |
1384 | ||
1385 | objnr = (objp-slabp->s_mem)/cachep->objsize; | |
1386 | if (objnr) { | |
1387 | objp = slabp->s_mem+(objnr-1)*cachep->objsize; | |
1388 | realobj = (char*)objp+obj_dbghead(cachep); | |
1389 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", | |
1390 | realobj, size); | |
1391 | print_objinfo(cachep, objp, 2); | |
1392 | } | |
1393 | if (objnr+1 < cachep->num) { | |
1394 | objp = slabp->s_mem+(objnr+1)*cachep->objsize; | |
1395 | realobj = (char*)objp+obj_dbghead(cachep); | |
1396 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", | |
1397 | realobj, size); | |
1398 | print_objinfo(cachep, objp, 2); | |
1399 | } | |
1400 | } | |
1401 | } | |
1402 | #endif | |
1403 | ||
1404 | /* Destroy all the objs in a slab, and release the mem back to the system. | |
1405 | * Before calling the slab must have been unlinked from the cache. | |
1406 | * The cache-lock is not held/needed. | |
1407 | */ | |
1408 | static void slab_destroy (kmem_cache_t *cachep, struct slab *slabp) | |
1409 | { | |
1410 | void *addr = slabp->s_mem - slabp->colouroff; | |
1411 | ||
1412 | #if DEBUG | |
1413 | int i; | |
1414 | for (i = 0; i < cachep->num; i++) { | |
1415 | void *objp = slabp->s_mem + cachep->objsize * i; | |
1416 | ||
1417 | if (cachep->flags & SLAB_POISON) { | |
1418 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1419 | if ((cachep->objsize%PAGE_SIZE)==0 && OFF_SLAB(cachep)) | |
1420 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE,1); | |
1421 | else | |
1422 | check_poison_obj(cachep, objp); | |
1423 | #else | |
1424 | check_poison_obj(cachep, objp); | |
1425 | #endif | |
1426 | } | |
1427 | if (cachep->flags & SLAB_RED_ZONE) { | |
1428 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
1429 | slab_error(cachep, "start of a freed object " | |
1430 | "was overwritten"); | |
1431 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
1432 | slab_error(cachep, "end of a freed object " | |
1433 | "was overwritten"); | |
1434 | } | |
1435 | if (cachep->dtor && !(cachep->flags & SLAB_POISON)) | |
1436 | (cachep->dtor)(objp+obj_dbghead(cachep), cachep, 0); | |
1437 | } | |
1438 | #else | |
1439 | if (cachep->dtor) { | |
1440 | int i; | |
1441 | for (i = 0; i < cachep->num; i++) { | |
1442 | void* objp = slabp->s_mem+cachep->objsize*i; | |
1443 | (cachep->dtor)(objp, cachep, 0); | |
1444 | } | |
1445 | } | |
1446 | #endif | |
1447 | ||
1448 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { | |
1449 | struct slab_rcu *slab_rcu; | |
1450 | ||
1451 | slab_rcu = (struct slab_rcu *) slabp; | |
1452 | slab_rcu->cachep = cachep; | |
1453 | slab_rcu->addr = addr; | |
1454 | call_rcu(&slab_rcu->head, kmem_rcu_free); | |
1455 | } else { | |
1456 | kmem_freepages(cachep, addr); | |
1457 | if (OFF_SLAB(cachep)) | |
1458 | kmem_cache_free(cachep->slabp_cache, slabp); | |
1459 | } | |
1460 | } | |
1461 | ||
e498be7d CL |
1462 | /* For setting up all the kmem_list3s for cache whose objsize is same |
1463 | as size of kmem_list3. */ | |
1464 | static inline void set_up_list3s(kmem_cache_t *cachep, int index) | |
1465 | { | |
1466 | int node; | |
1467 | ||
1468 | for_each_online_node(node) { | |
1469 | cachep->nodelists[node] = &initkmem_list3[index+node]; | |
1470 | cachep->nodelists[node]->next_reap = jiffies + | |
1471 | REAPTIMEOUT_LIST3 + | |
1472 | ((unsigned long)cachep)%REAPTIMEOUT_LIST3; | |
1473 | } | |
1474 | } | |
1475 | ||
4d268eba PE |
1476 | /** |
1477 | * calculate_slab_order - calculate size (page order) of slabs and the number | |
1478 | * of objects per slab. | |
1479 | * | |
1480 | * This could be made much more intelligent. For now, try to avoid using | |
1481 | * high order pages for slabs. When the gfp() functions are more friendly | |
1482 | * towards high-order requests, this should be changed. | |
1483 | */ | |
1484 | static inline size_t calculate_slab_order(kmem_cache_t *cachep, size_t size, | |
1485 | size_t align, gfp_t flags) | |
1486 | { | |
1487 | size_t left_over = 0; | |
1488 | ||
1489 | for ( ; ; cachep->gfporder++) { | |
1490 | unsigned int num; | |
1491 | size_t remainder; | |
1492 | ||
1493 | if (cachep->gfporder > MAX_GFP_ORDER) { | |
1494 | cachep->num = 0; | |
1495 | break; | |
1496 | } | |
1497 | ||
1498 | cache_estimate(cachep->gfporder, size, align, flags, | |
1499 | &remainder, &num); | |
1500 | if (!num) | |
1501 | continue; | |
1502 | /* More than offslab_limit objects will cause problems */ | |
1503 | if (flags & CFLGS_OFF_SLAB && cachep->num > offslab_limit) | |
1504 | break; | |
1505 | ||
1506 | cachep->num = num; | |
1507 | left_over = remainder; | |
1508 | ||
1509 | /* | |
1510 | * Large number of objects is good, but very large slabs are | |
1511 | * currently bad for the gfp()s. | |
1512 | */ | |
1513 | if (cachep->gfporder >= slab_break_gfp_order) | |
1514 | break; | |
1515 | ||
1516 | if ((left_over * 8) <= (PAGE_SIZE << cachep->gfporder)) | |
1517 | /* Acceptable internal fragmentation */ | |
1518 | break; | |
1519 | } | |
1520 | return left_over; | |
1521 | } | |
1522 | ||
1da177e4 LT |
1523 | /** |
1524 | * kmem_cache_create - Create a cache. | |
1525 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
1526 | * @size: The size of objects to be created in this cache. | |
1527 | * @align: The required alignment for the objects. | |
1528 | * @flags: SLAB flags | |
1529 | * @ctor: A constructor for the objects. | |
1530 | * @dtor: A destructor for the objects. | |
1531 | * | |
1532 | * Returns a ptr to the cache on success, NULL on failure. | |
1533 | * Cannot be called within a int, but can be interrupted. | |
1534 | * The @ctor is run when new pages are allocated by the cache | |
1535 | * and the @dtor is run before the pages are handed back. | |
1536 | * | |
1537 | * @name must be valid until the cache is destroyed. This implies that | |
1538 | * the module calling this has to destroy the cache before getting | |
1539 | * unloaded. | |
1540 | * | |
1541 | * The flags are | |
1542 | * | |
1543 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
1544 | * to catch references to uninitialised memory. | |
1545 | * | |
1546 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
1547 | * for buffer overruns. | |
1548 | * | |
1549 | * %SLAB_NO_REAP - Don't automatically reap this cache when we're under | |
1550 | * memory pressure. | |
1551 | * | |
1552 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
1553 | * cacheline. This can be beneficial if you're counting cycles as closely | |
1554 | * as davem. | |
1555 | */ | |
1556 | kmem_cache_t * | |
1557 | kmem_cache_create (const char *name, size_t size, size_t align, | |
1558 | unsigned long flags, void (*ctor)(void*, kmem_cache_t *, unsigned long), | |
1559 | void (*dtor)(void*, kmem_cache_t *, unsigned long)) | |
1560 | { | |
1561 | size_t left_over, slab_size, ralign; | |
1562 | kmem_cache_t *cachep = NULL; | |
4f12bb4f | 1563 | struct list_head *p; |
1da177e4 LT |
1564 | |
1565 | /* | |
1566 | * Sanity checks... these are all serious usage bugs. | |
1567 | */ | |
1568 | if ((!name) || | |
1569 | in_interrupt() || | |
1570 | (size < BYTES_PER_WORD) || | |
1571 | (size > (1<<MAX_OBJ_ORDER)*PAGE_SIZE) || | |
1572 | (dtor && !ctor)) { | |
1573 | printk(KERN_ERR "%s: Early error in slab %s\n", | |
1574 | __FUNCTION__, name); | |
1575 | BUG(); | |
1576 | } | |
1577 | ||
4f12bb4f AM |
1578 | down(&cache_chain_sem); |
1579 | ||
1580 | list_for_each(p, &cache_chain) { | |
1581 | kmem_cache_t *pc = list_entry(p, kmem_cache_t, next); | |
1582 | mm_segment_t old_fs = get_fs(); | |
1583 | char tmp; | |
1584 | int res; | |
1585 | ||
1586 | /* | |
1587 | * This happens when the module gets unloaded and doesn't | |
1588 | * destroy its slab cache and no-one else reuses the vmalloc | |
1589 | * area of the module. Print a warning. | |
1590 | */ | |
1591 | set_fs(KERNEL_DS); | |
1592 | res = __get_user(tmp, pc->name); | |
1593 | set_fs(old_fs); | |
1594 | if (res) { | |
1595 | printk("SLAB: cache with size %d has lost its name\n", | |
1596 | pc->objsize); | |
1597 | continue; | |
1598 | } | |
1599 | ||
1600 | if (!strcmp(pc->name,name)) { | |
1601 | printk("kmem_cache_create: duplicate cache %s\n", name); | |
1602 | dump_stack(); | |
1603 | goto oops; | |
1604 | } | |
1605 | } | |
1606 | ||
1da177e4 LT |
1607 | #if DEBUG |
1608 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ | |
1609 | if ((flags & SLAB_DEBUG_INITIAL) && !ctor) { | |
1610 | /* No constructor, but inital state check requested */ | |
1611 | printk(KERN_ERR "%s: No con, but init state check " | |
1612 | "requested - %s\n", __FUNCTION__, name); | |
1613 | flags &= ~SLAB_DEBUG_INITIAL; | |
1614 | } | |
1615 | ||
1616 | #if FORCED_DEBUG | |
1617 | /* | |
1618 | * Enable redzoning and last user accounting, except for caches with | |
1619 | * large objects, if the increased size would increase the object size | |
1620 | * above the next power of two: caches with object sizes just above a | |
1621 | * power of two have a significant amount of internal fragmentation. | |
1622 | */ | |
1623 | if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD))) | |
1624 | flags |= SLAB_RED_ZONE|SLAB_STORE_USER; | |
1625 | if (!(flags & SLAB_DESTROY_BY_RCU)) | |
1626 | flags |= SLAB_POISON; | |
1627 | #endif | |
1628 | if (flags & SLAB_DESTROY_BY_RCU) | |
1629 | BUG_ON(flags & SLAB_POISON); | |
1630 | #endif | |
1631 | if (flags & SLAB_DESTROY_BY_RCU) | |
1632 | BUG_ON(dtor); | |
1633 | ||
1634 | /* | |
1635 | * Always checks flags, a caller might be expecting debug | |
1636 | * support which isn't available. | |
1637 | */ | |
1638 | if (flags & ~CREATE_MASK) | |
1639 | BUG(); | |
1640 | ||
1641 | /* Check that size is in terms of words. This is needed to avoid | |
1642 | * unaligned accesses for some archs when redzoning is used, and makes | |
1643 | * sure any on-slab bufctl's are also correctly aligned. | |
1644 | */ | |
1645 | if (size & (BYTES_PER_WORD-1)) { | |
1646 | size += (BYTES_PER_WORD-1); | |
1647 | size &= ~(BYTES_PER_WORD-1); | |
1648 | } | |
1649 | ||
1650 | /* calculate out the final buffer alignment: */ | |
1651 | /* 1) arch recommendation: can be overridden for debug */ | |
1652 | if (flags & SLAB_HWCACHE_ALIGN) { | |
1653 | /* Default alignment: as specified by the arch code. | |
1654 | * Except if an object is really small, then squeeze multiple | |
1655 | * objects into one cacheline. | |
1656 | */ | |
1657 | ralign = cache_line_size(); | |
1658 | while (size <= ralign/2) | |
1659 | ralign /= 2; | |
1660 | } else { | |
1661 | ralign = BYTES_PER_WORD; | |
1662 | } | |
1663 | /* 2) arch mandated alignment: disables debug if necessary */ | |
1664 | if (ralign < ARCH_SLAB_MINALIGN) { | |
1665 | ralign = ARCH_SLAB_MINALIGN; | |
1666 | if (ralign > BYTES_PER_WORD) | |
1667 | flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER); | |
1668 | } | |
1669 | /* 3) caller mandated alignment: disables debug if necessary */ | |
1670 | if (ralign < align) { | |
1671 | ralign = align; | |
1672 | if (ralign > BYTES_PER_WORD) | |
1673 | flags &= ~(SLAB_RED_ZONE|SLAB_STORE_USER); | |
1674 | } | |
1675 | /* 4) Store it. Note that the debug code below can reduce | |
1676 | * the alignment to BYTES_PER_WORD. | |
1677 | */ | |
1678 | align = ralign; | |
1679 | ||
1680 | /* Get cache's description obj. */ | |
1681 | cachep = (kmem_cache_t *) kmem_cache_alloc(&cache_cache, SLAB_KERNEL); | |
1682 | if (!cachep) | |
4f12bb4f | 1683 | goto oops; |
1da177e4 LT |
1684 | memset(cachep, 0, sizeof(kmem_cache_t)); |
1685 | ||
1686 | #if DEBUG | |
1687 | cachep->reallen = size; | |
1688 | ||
1689 | if (flags & SLAB_RED_ZONE) { | |
1690 | /* redzoning only works with word aligned caches */ | |
1691 | align = BYTES_PER_WORD; | |
1692 | ||
1693 | /* add space for red zone words */ | |
1694 | cachep->dbghead += BYTES_PER_WORD; | |
1695 | size += 2*BYTES_PER_WORD; | |
1696 | } | |
1697 | if (flags & SLAB_STORE_USER) { | |
1698 | /* user store requires word alignment and | |
1699 | * one word storage behind the end of the real | |
1700 | * object. | |
1701 | */ | |
1702 | align = BYTES_PER_WORD; | |
1703 | size += BYTES_PER_WORD; | |
1704 | } | |
1705 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) | |
e498be7d | 1706 | if (size >= malloc_sizes[INDEX_L3+1].cs_size && cachep->reallen > cache_line_size() && size < PAGE_SIZE) { |
1da177e4 LT |
1707 | cachep->dbghead += PAGE_SIZE - size; |
1708 | size = PAGE_SIZE; | |
1709 | } | |
1710 | #endif | |
1711 | #endif | |
1712 | ||
1713 | /* Determine if the slab management is 'on' or 'off' slab. */ | |
1714 | if (size >= (PAGE_SIZE>>3)) | |
1715 | /* | |
1716 | * Size is large, assume best to place the slab management obj | |
1717 | * off-slab (should allow better packing of objs). | |
1718 | */ | |
1719 | flags |= CFLGS_OFF_SLAB; | |
1720 | ||
1721 | size = ALIGN(size, align); | |
1722 | ||
1723 | if ((flags & SLAB_RECLAIM_ACCOUNT) && size <= PAGE_SIZE) { | |
1724 | /* | |
1725 | * A VFS-reclaimable slab tends to have most allocations | |
1726 | * as GFP_NOFS and we really don't want to have to be allocating | |
1727 | * higher-order pages when we are unable to shrink dcache. | |
1728 | */ | |
1729 | cachep->gfporder = 0; | |
1730 | cache_estimate(cachep->gfporder, size, align, flags, | |
1731 | &left_over, &cachep->num); | |
4d268eba PE |
1732 | } else |
1733 | left_over = calculate_slab_order(cachep, size, align, flags); | |
1da177e4 LT |
1734 | |
1735 | if (!cachep->num) { | |
1736 | printk("kmem_cache_create: couldn't create cache %s.\n", name); | |
1737 | kmem_cache_free(&cache_cache, cachep); | |
1738 | cachep = NULL; | |
4f12bb4f | 1739 | goto oops; |
1da177e4 LT |
1740 | } |
1741 | slab_size = ALIGN(cachep->num*sizeof(kmem_bufctl_t) | |
1742 | + sizeof(struct slab), align); | |
1743 | ||
1744 | /* | |
1745 | * If the slab has been placed off-slab, and we have enough space then | |
1746 | * move it on-slab. This is at the expense of any extra colouring. | |
1747 | */ | |
1748 | if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { | |
1749 | flags &= ~CFLGS_OFF_SLAB; | |
1750 | left_over -= slab_size; | |
1751 | } | |
1752 | ||
1753 | if (flags & CFLGS_OFF_SLAB) { | |
1754 | /* really off slab. No need for manual alignment */ | |
1755 | slab_size = cachep->num*sizeof(kmem_bufctl_t)+sizeof(struct slab); | |
1756 | } | |
1757 | ||
1758 | cachep->colour_off = cache_line_size(); | |
1759 | /* Offset must be a multiple of the alignment. */ | |
1760 | if (cachep->colour_off < align) | |
1761 | cachep->colour_off = align; | |
1762 | cachep->colour = left_over/cachep->colour_off; | |
1763 | cachep->slab_size = slab_size; | |
1764 | cachep->flags = flags; | |
1765 | cachep->gfpflags = 0; | |
1766 | if (flags & SLAB_CACHE_DMA) | |
1767 | cachep->gfpflags |= GFP_DMA; | |
1768 | spin_lock_init(&cachep->spinlock); | |
1769 | cachep->objsize = size; | |
1da177e4 LT |
1770 | |
1771 | if (flags & CFLGS_OFF_SLAB) | |
b2d55073 | 1772 | cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); |
1da177e4 LT |
1773 | cachep->ctor = ctor; |
1774 | cachep->dtor = dtor; | |
1775 | cachep->name = name; | |
1776 | ||
1777 | /* Don't let CPUs to come and go */ | |
1778 | lock_cpu_hotplug(); | |
1779 | ||
1780 | if (g_cpucache_up == FULL) { | |
1781 | enable_cpucache(cachep); | |
1782 | } else { | |
1783 | if (g_cpucache_up == NONE) { | |
1784 | /* Note: the first kmem_cache_create must create | |
1785 | * the cache that's used by kmalloc(24), otherwise | |
1786 | * the creation of further caches will BUG(). | |
1787 | */ | |
e498be7d CL |
1788 | cachep->array[smp_processor_id()] = |
1789 | &initarray_generic.cache; | |
1790 | ||
1791 | /* If the cache that's used by | |
1792 | * kmalloc(sizeof(kmem_list3)) is the first cache, | |
1793 | * then we need to set up all its list3s, otherwise | |
1794 | * the creation of further caches will BUG(). | |
1795 | */ | |
1796 | set_up_list3s(cachep, SIZE_AC); | |
1797 | if (INDEX_AC == INDEX_L3) | |
1798 | g_cpucache_up = PARTIAL_L3; | |
1799 | else | |
1800 | g_cpucache_up = PARTIAL_AC; | |
1da177e4 | 1801 | } else { |
e498be7d CL |
1802 | cachep->array[smp_processor_id()] = |
1803 | kmalloc(sizeof(struct arraycache_init), | |
1804 | GFP_KERNEL); | |
1805 | ||
1806 | if (g_cpucache_up == PARTIAL_AC) { | |
1807 | set_up_list3s(cachep, SIZE_L3); | |
1808 | g_cpucache_up = PARTIAL_L3; | |
1809 | } else { | |
1810 | int node; | |
1811 | for_each_online_node(node) { | |
1812 | ||
1813 | cachep->nodelists[node] = | |
1814 | kmalloc_node(sizeof(struct kmem_list3), | |
1815 | GFP_KERNEL, node); | |
1816 | BUG_ON(!cachep->nodelists[node]); | |
1817 | kmem_list3_init(cachep->nodelists[node]); | |
1818 | } | |
1819 | } | |
1da177e4 | 1820 | } |
e498be7d CL |
1821 | cachep->nodelists[numa_node_id()]->next_reap = |
1822 | jiffies + REAPTIMEOUT_LIST3 + | |
1823 | ((unsigned long)cachep)%REAPTIMEOUT_LIST3; | |
1824 | ||
1da177e4 LT |
1825 | BUG_ON(!ac_data(cachep)); |
1826 | ac_data(cachep)->avail = 0; | |
1827 | ac_data(cachep)->limit = BOOT_CPUCACHE_ENTRIES; | |
1828 | ac_data(cachep)->batchcount = 1; | |
1829 | ac_data(cachep)->touched = 0; | |
1830 | cachep->batchcount = 1; | |
1831 | cachep->limit = BOOT_CPUCACHE_ENTRIES; | |
1da177e4 LT |
1832 | } |
1833 | ||
1da177e4 LT |
1834 | /* cache setup completed, link it into the list */ |
1835 | list_add(&cachep->next, &cache_chain); | |
1da177e4 | 1836 | unlock_cpu_hotplug(); |
4f12bb4f | 1837 | oops: |
1da177e4 LT |
1838 | if (!cachep && (flags & SLAB_PANIC)) |
1839 | panic("kmem_cache_create(): failed to create slab `%s'\n", | |
1840 | name); | |
4f12bb4f | 1841 | up(&cache_chain_sem); |
1da177e4 LT |
1842 | return cachep; |
1843 | } | |
1844 | EXPORT_SYMBOL(kmem_cache_create); | |
1845 | ||
1846 | #if DEBUG | |
1847 | static void check_irq_off(void) | |
1848 | { | |
1849 | BUG_ON(!irqs_disabled()); | |
1850 | } | |
1851 | ||
1852 | static void check_irq_on(void) | |
1853 | { | |
1854 | BUG_ON(irqs_disabled()); | |
1855 | } | |
1856 | ||
1857 | static void check_spinlock_acquired(kmem_cache_t *cachep) | |
1858 | { | |
1859 | #ifdef CONFIG_SMP | |
1860 | check_irq_off(); | |
e498be7d | 1861 | assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock); |
1da177e4 LT |
1862 | #endif |
1863 | } | |
e498be7d CL |
1864 | |
1865 | static inline void check_spinlock_acquired_node(kmem_cache_t *cachep, int node) | |
1866 | { | |
1867 | #ifdef CONFIG_SMP | |
1868 | check_irq_off(); | |
1869 | assert_spin_locked(&cachep->nodelists[node]->list_lock); | |
1870 | #endif | |
1871 | } | |
1872 | ||
1da177e4 LT |
1873 | #else |
1874 | #define check_irq_off() do { } while(0) | |
1875 | #define check_irq_on() do { } while(0) | |
1876 | #define check_spinlock_acquired(x) do { } while(0) | |
e498be7d | 1877 | #define check_spinlock_acquired_node(x, y) do { } while(0) |
1da177e4 LT |
1878 | #endif |
1879 | ||
1880 | /* | |
1881 | * Waits for all CPUs to execute func(). | |
1882 | */ | |
1883 | static void smp_call_function_all_cpus(void (*func) (void *arg), void *arg) | |
1884 | { | |
1885 | check_irq_on(); | |
1886 | preempt_disable(); | |
1887 | ||
1888 | local_irq_disable(); | |
1889 | func(arg); | |
1890 | local_irq_enable(); | |
1891 | ||
1892 | if (smp_call_function(func, arg, 1, 1)) | |
1893 | BUG(); | |
1894 | ||
1895 | preempt_enable(); | |
1896 | } | |
1897 | ||
1898 | static void drain_array_locked(kmem_cache_t* cachep, | |
e498be7d | 1899 | struct array_cache *ac, int force, int node); |
1da177e4 LT |
1900 | |
1901 | static void do_drain(void *arg) | |
1902 | { | |
1903 | kmem_cache_t *cachep = (kmem_cache_t*)arg; | |
1904 | struct array_cache *ac; | |
ff69416e | 1905 | int node = numa_node_id(); |
1da177e4 LT |
1906 | |
1907 | check_irq_off(); | |
1908 | ac = ac_data(cachep); | |
ff69416e CL |
1909 | spin_lock(&cachep->nodelists[node]->list_lock); |
1910 | free_block(cachep, ac->entry, ac->avail, node); | |
1911 | spin_unlock(&cachep->nodelists[node]->list_lock); | |
1da177e4 LT |
1912 | ac->avail = 0; |
1913 | } | |
1914 | ||
1915 | static void drain_cpu_caches(kmem_cache_t *cachep) | |
1916 | { | |
e498be7d CL |
1917 | struct kmem_list3 *l3; |
1918 | int node; | |
1919 | ||
1da177e4 LT |
1920 | smp_call_function_all_cpus(do_drain, cachep); |
1921 | check_irq_on(); | |
1922 | spin_lock_irq(&cachep->spinlock); | |
e498be7d CL |
1923 | for_each_online_node(node) { |
1924 | l3 = cachep->nodelists[node]; | |
1925 | if (l3) { | |
1926 | spin_lock(&l3->list_lock); | |
1927 | drain_array_locked(cachep, l3->shared, 1, node); | |
1928 | spin_unlock(&l3->list_lock); | |
1929 | if (l3->alien) | |
1930 | drain_alien_cache(cachep, l3); | |
1931 | } | |
1932 | } | |
1da177e4 LT |
1933 | spin_unlock_irq(&cachep->spinlock); |
1934 | } | |
1935 | ||
e498be7d | 1936 | static int __node_shrink(kmem_cache_t *cachep, int node) |
1da177e4 LT |
1937 | { |
1938 | struct slab *slabp; | |
e498be7d | 1939 | struct kmem_list3 *l3 = cachep->nodelists[node]; |
1da177e4 LT |
1940 | int ret; |
1941 | ||
e498be7d | 1942 | for (;;) { |
1da177e4 LT |
1943 | struct list_head *p; |
1944 | ||
e498be7d CL |
1945 | p = l3->slabs_free.prev; |
1946 | if (p == &l3->slabs_free) | |
1da177e4 LT |
1947 | break; |
1948 | ||
e498be7d | 1949 | slabp = list_entry(l3->slabs_free.prev, struct slab, list); |
1da177e4 LT |
1950 | #if DEBUG |
1951 | if (slabp->inuse) | |
1952 | BUG(); | |
1953 | #endif | |
1954 | list_del(&slabp->list); | |
1955 | ||
e498be7d CL |
1956 | l3->free_objects -= cachep->num; |
1957 | spin_unlock_irq(&l3->list_lock); | |
1da177e4 | 1958 | slab_destroy(cachep, slabp); |
e498be7d | 1959 | spin_lock_irq(&l3->list_lock); |
1da177e4 | 1960 | } |
e498be7d CL |
1961 | ret = !list_empty(&l3->slabs_full) || |
1962 | !list_empty(&l3->slabs_partial); | |
1da177e4 LT |
1963 | return ret; |
1964 | } | |
1965 | ||
e498be7d CL |
1966 | static int __cache_shrink(kmem_cache_t *cachep) |
1967 | { | |
1968 | int ret = 0, i = 0; | |
1969 | struct kmem_list3 *l3; | |
1970 | ||
1971 | drain_cpu_caches(cachep); | |
1972 | ||
1973 | check_irq_on(); | |
1974 | for_each_online_node(i) { | |
1975 | l3 = cachep->nodelists[i]; | |
1976 | if (l3) { | |
1977 | spin_lock_irq(&l3->list_lock); | |
1978 | ret += __node_shrink(cachep, i); | |
1979 | spin_unlock_irq(&l3->list_lock); | |
1980 | } | |
1981 | } | |
1982 | return (ret ? 1 : 0); | |
1983 | } | |
1984 | ||
1da177e4 LT |
1985 | /** |
1986 | * kmem_cache_shrink - Shrink a cache. | |
1987 | * @cachep: The cache to shrink. | |
1988 | * | |
1989 | * Releases as many slabs as possible for a cache. | |
1990 | * To help debugging, a zero exit status indicates all slabs were released. | |
1991 | */ | |
1992 | int kmem_cache_shrink(kmem_cache_t *cachep) | |
1993 | { | |
1994 | if (!cachep || in_interrupt()) | |
1995 | BUG(); | |
1996 | ||
1997 | return __cache_shrink(cachep); | |
1998 | } | |
1999 | EXPORT_SYMBOL(kmem_cache_shrink); | |
2000 | ||
2001 | /** | |
2002 | * kmem_cache_destroy - delete a cache | |
2003 | * @cachep: the cache to destroy | |
2004 | * | |
2005 | * Remove a kmem_cache_t object from the slab cache. | |
2006 | * Returns 0 on success. | |
2007 | * | |
2008 | * It is expected this function will be called by a module when it is | |
2009 | * unloaded. This will remove the cache completely, and avoid a duplicate | |
2010 | * cache being allocated each time a module is loaded and unloaded, if the | |
2011 | * module doesn't have persistent in-kernel storage across loads and unloads. | |
2012 | * | |
2013 | * The cache must be empty before calling this function. | |
2014 | * | |
2015 | * The caller must guarantee that noone will allocate memory from the cache | |
2016 | * during the kmem_cache_destroy(). | |
2017 | */ | |
2018 | int kmem_cache_destroy(kmem_cache_t * cachep) | |
2019 | { | |
2020 | int i; | |
e498be7d | 2021 | struct kmem_list3 *l3; |
1da177e4 LT |
2022 | |
2023 | if (!cachep || in_interrupt()) | |
2024 | BUG(); | |
2025 | ||
2026 | /* Don't let CPUs to come and go */ | |
2027 | lock_cpu_hotplug(); | |
2028 | ||
2029 | /* Find the cache in the chain of caches. */ | |
2030 | down(&cache_chain_sem); | |
2031 | /* | |
2032 | * the chain is never empty, cache_cache is never destroyed | |
2033 | */ | |
2034 | list_del(&cachep->next); | |
2035 | up(&cache_chain_sem); | |
2036 | ||
2037 | if (__cache_shrink(cachep)) { | |
2038 | slab_error(cachep, "Can't free all objects"); | |
2039 | down(&cache_chain_sem); | |
2040 | list_add(&cachep->next,&cache_chain); | |
2041 | up(&cache_chain_sem); | |
2042 | unlock_cpu_hotplug(); | |
2043 | return 1; | |
2044 | } | |
2045 | ||
2046 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) | |
fbd568a3 | 2047 | synchronize_rcu(); |
1da177e4 | 2048 | |
e498be7d | 2049 | for_each_online_cpu(i) |
1da177e4 LT |
2050 | kfree(cachep->array[i]); |
2051 | ||
2052 | /* NUMA: free the list3 structures */ | |
e498be7d CL |
2053 | for_each_online_node(i) { |
2054 | if ((l3 = cachep->nodelists[i])) { | |
2055 | kfree(l3->shared); | |
2056 | free_alien_cache(l3->alien); | |
2057 | kfree(l3); | |
2058 | } | |
2059 | } | |
1da177e4 LT |
2060 | kmem_cache_free(&cache_cache, cachep); |
2061 | ||
2062 | unlock_cpu_hotplug(); | |
2063 | ||
2064 | return 0; | |
2065 | } | |
2066 | EXPORT_SYMBOL(kmem_cache_destroy); | |
2067 | ||
2068 | /* Get the memory for a slab management obj. */ | |
e498be7d | 2069 | static struct slab* alloc_slabmgmt(kmem_cache_t *cachep, void *objp, |
dd0fc66f | 2070 | int colour_off, gfp_t local_flags) |
1da177e4 LT |
2071 | { |
2072 | struct slab *slabp; | |
2073 | ||
2074 | if (OFF_SLAB(cachep)) { | |
2075 | /* Slab management obj is off-slab. */ | |
2076 | slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags); | |
2077 | if (!slabp) | |
2078 | return NULL; | |
2079 | } else { | |
2080 | slabp = objp+colour_off; | |
2081 | colour_off += cachep->slab_size; | |
2082 | } | |
2083 | slabp->inuse = 0; | |
2084 | slabp->colouroff = colour_off; | |
2085 | slabp->s_mem = objp+colour_off; | |
2086 | ||
2087 | return slabp; | |
2088 | } | |
2089 | ||
2090 | static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) | |
2091 | { | |
2092 | return (kmem_bufctl_t *)(slabp+1); | |
2093 | } | |
2094 | ||
2095 | static void cache_init_objs(kmem_cache_t *cachep, | |
2096 | struct slab *slabp, unsigned long ctor_flags) | |
2097 | { | |
2098 | int i; | |
2099 | ||
2100 | for (i = 0; i < cachep->num; i++) { | |
e498be7d | 2101 | void *objp = slabp->s_mem+cachep->objsize*i; |
1da177e4 LT |
2102 | #if DEBUG |
2103 | /* need to poison the objs? */ | |
2104 | if (cachep->flags & SLAB_POISON) | |
2105 | poison_obj(cachep, objp, POISON_FREE); | |
2106 | if (cachep->flags & SLAB_STORE_USER) | |
2107 | *dbg_userword(cachep, objp) = NULL; | |
2108 | ||
2109 | if (cachep->flags & SLAB_RED_ZONE) { | |
2110 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2111 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2112 | } | |
2113 | /* | |
2114 | * Constructors are not allowed to allocate memory from | |
2115 | * the same cache which they are a constructor for. | |
2116 | * Otherwise, deadlock. They must also be threaded. | |
2117 | */ | |
2118 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) | |
2119 | cachep->ctor(objp+obj_dbghead(cachep), cachep, ctor_flags); | |
2120 | ||
2121 | if (cachep->flags & SLAB_RED_ZONE) { | |
2122 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
2123 | slab_error(cachep, "constructor overwrote the" | |
2124 | " end of an object"); | |
2125 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
2126 | slab_error(cachep, "constructor overwrote the" | |
2127 | " start of an object"); | |
2128 | } | |
2129 | if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) | |
2130 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0); | |
2131 | #else | |
2132 | if (cachep->ctor) | |
2133 | cachep->ctor(objp, cachep, ctor_flags); | |
2134 | #endif | |
2135 | slab_bufctl(slabp)[i] = i+1; | |
2136 | } | |
2137 | slab_bufctl(slabp)[i-1] = BUFCTL_END; | |
2138 | slabp->free = 0; | |
2139 | } | |
2140 | ||
6daa0e28 | 2141 | static void kmem_flagcheck(kmem_cache_t *cachep, gfp_t flags) |
1da177e4 LT |
2142 | { |
2143 | if (flags & SLAB_DMA) { | |
2144 | if (!(cachep->gfpflags & GFP_DMA)) | |
2145 | BUG(); | |
2146 | } else { | |
2147 | if (cachep->gfpflags & GFP_DMA) | |
2148 | BUG(); | |
2149 | } | |
2150 | } | |
2151 | ||
2152 | static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp) | |
2153 | { | |
2154 | int i; | |
2155 | struct page *page; | |
2156 | ||
2157 | /* Nasty!!!!!! I hope this is OK. */ | |
2158 | i = 1 << cachep->gfporder; | |
2159 | page = virt_to_page(objp); | |
2160 | do { | |
065d41cb PE |
2161 | page_set_cache(page, cachep); |
2162 | page_set_slab(page, slabp); | |
1da177e4 LT |
2163 | page++; |
2164 | } while (--i); | |
2165 | } | |
2166 | ||
2167 | /* | |
2168 | * Grow (by 1) the number of slabs within a cache. This is called by | |
2169 | * kmem_cache_alloc() when there are no active objs left in a cache. | |
2170 | */ | |
dd0fc66f | 2171 | static int cache_grow(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
1da177e4 LT |
2172 | { |
2173 | struct slab *slabp; | |
2174 | void *objp; | |
2175 | size_t offset; | |
6daa0e28 | 2176 | gfp_t local_flags; |
1da177e4 | 2177 | unsigned long ctor_flags; |
e498be7d | 2178 | struct kmem_list3 *l3; |
1da177e4 LT |
2179 | |
2180 | /* Be lazy and only check for valid flags here, | |
2181 | * keeping it out of the critical path in kmem_cache_alloc(). | |
2182 | */ | |
2183 | if (flags & ~(SLAB_DMA|SLAB_LEVEL_MASK|SLAB_NO_GROW)) | |
2184 | BUG(); | |
2185 | if (flags & SLAB_NO_GROW) | |
2186 | return 0; | |
2187 | ||
2188 | ctor_flags = SLAB_CTOR_CONSTRUCTOR; | |
2189 | local_flags = (flags & SLAB_LEVEL_MASK); | |
2190 | if (!(local_flags & __GFP_WAIT)) | |
2191 | /* | |
2192 | * Not allowed to sleep. Need to tell a constructor about | |
2193 | * this - it might need to know... | |
2194 | */ | |
2195 | ctor_flags |= SLAB_CTOR_ATOMIC; | |
2196 | ||
2197 | /* About to mess with non-constant members - lock. */ | |
2198 | check_irq_off(); | |
2199 | spin_lock(&cachep->spinlock); | |
2200 | ||
2201 | /* Get colour for the slab, and cal the next value. */ | |
2202 | offset = cachep->colour_next; | |
2203 | cachep->colour_next++; | |
2204 | if (cachep->colour_next >= cachep->colour) | |
2205 | cachep->colour_next = 0; | |
2206 | offset *= cachep->colour_off; | |
2207 | ||
2208 | spin_unlock(&cachep->spinlock); | |
2209 | ||
e498be7d | 2210 | check_irq_off(); |
1da177e4 LT |
2211 | if (local_flags & __GFP_WAIT) |
2212 | local_irq_enable(); | |
2213 | ||
2214 | /* | |
2215 | * The test for missing atomic flag is performed here, rather than | |
2216 | * the more obvious place, simply to reduce the critical path length | |
2217 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they | |
2218 | * will eventually be caught here (where it matters). | |
2219 | */ | |
2220 | kmem_flagcheck(cachep, flags); | |
2221 | ||
e498be7d CL |
2222 | /* Get mem for the objs. |
2223 | * Attempt to allocate a physical page from 'nodeid', | |
2224 | */ | |
1da177e4 LT |
2225 | if (!(objp = kmem_getpages(cachep, flags, nodeid))) |
2226 | goto failed; | |
2227 | ||
2228 | /* Get slab management. */ | |
2229 | if (!(slabp = alloc_slabmgmt(cachep, objp, offset, local_flags))) | |
2230 | goto opps1; | |
2231 | ||
e498be7d | 2232 | slabp->nodeid = nodeid; |
1da177e4 LT |
2233 | set_slab_attr(cachep, slabp, objp); |
2234 | ||
2235 | cache_init_objs(cachep, slabp, ctor_flags); | |
2236 | ||
2237 | if (local_flags & __GFP_WAIT) | |
2238 | local_irq_disable(); | |
2239 | check_irq_off(); | |
e498be7d CL |
2240 | l3 = cachep->nodelists[nodeid]; |
2241 | spin_lock(&l3->list_lock); | |
1da177e4 LT |
2242 | |
2243 | /* Make slab active. */ | |
e498be7d | 2244 | list_add_tail(&slabp->list, &(l3->slabs_free)); |
1da177e4 | 2245 | STATS_INC_GROWN(cachep); |
e498be7d CL |
2246 | l3->free_objects += cachep->num; |
2247 | spin_unlock(&l3->list_lock); | |
1da177e4 LT |
2248 | return 1; |
2249 | opps1: | |
2250 | kmem_freepages(cachep, objp); | |
2251 | failed: | |
2252 | if (local_flags & __GFP_WAIT) | |
2253 | local_irq_disable(); | |
2254 | return 0; | |
2255 | } | |
2256 | ||
2257 | #if DEBUG | |
2258 | ||
2259 | /* | |
2260 | * Perform extra freeing checks: | |
2261 | * - detect bad pointers. | |
2262 | * - POISON/RED_ZONE checking | |
2263 | * - destructor calls, for caches with POISON+dtor | |
2264 | */ | |
2265 | static void kfree_debugcheck(const void *objp) | |
2266 | { | |
2267 | struct page *page; | |
2268 | ||
2269 | if (!virt_addr_valid(objp)) { | |
2270 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", | |
2271 | (unsigned long)objp); | |
2272 | BUG(); | |
2273 | } | |
2274 | page = virt_to_page(objp); | |
2275 | if (!PageSlab(page)) { | |
2276 | printk(KERN_ERR "kfree_debugcheck: bad ptr %lxh.\n", (unsigned long)objp); | |
2277 | BUG(); | |
2278 | } | |
2279 | } | |
2280 | ||
2281 | static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp, | |
2282 | void *caller) | |
2283 | { | |
2284 | struct page *page; | |
2285 | unsigned int objnr; | |
2286 | struct slab *slabp; | |
2287 | ||
2288 | objp -= obj_dbghead(cachep); | |
2289 | kfree_debugcheck(objp); | |
2290 | page = virt_to_page(objp); | |
2291 | ||
065d41cb | 2292 | if (page_get_cache(page) != cachep) { |
1da177e4 | 2293 | printk(KERN_ERR "mismatch in kmem_cache_free: expected cache %p, got %p\n", |
065d41cb | 2294 | page_get_cache(page),cachep); |
1da177e4 | 2295 | printk(KERN_ERR "%p is %s.\n", cachep, cachep->name); |
065d41cb | 2296 | printk(KERN_ERR "%p is %s.\n", page_get_cache(page), page_get_cache(page)->name); |
1da177e4 LT |
2297 | WARN_ON(1); |
2298 | } | |
065d41cb | 2299 | slabp = page_get_slab(page); |
1da177e4 LT |
2300 | |
2301 | if (cachep->flags & SLAB_RED_ZONE) { | |
2302 | if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || *dbg_redzone2(cachep, objp) != RED_ACTIVE) { | |
2303 | slab_error(cachep, "double free, or memory outside" | |
2304 | " object was overwritten"); | |
2305 | printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n", | |
2306 | objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp)); | |
2307 | } | |
2308 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2309 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2310 | } | |
2311 | if (cachep->flags & SLAB_STORE_USER) | |
2312 | *dbg_userword(cachep, objp) = caller; | |
2313 | ||
2314 | objnr = (objp-slabp->s_mem)/cachep->objsize; | |
2315 | ||
2316 | BUG_ON(objnr >= cachep->num); | |
2317 | BUG_ON(objp != slabp->s_mem + objnr*cachep->objsize); | |
2318 | ||
2319 | if (cachep->flags & SLAB_DEBUG_INITIAL) { | |
2320 | /* Need to call the slab's constructor so the | |
2321 | * caller can perform a verify of its state (debugging). | |
2322 | * Called without the cache-lock held. | |
2323 | */ | |
2324 | cachep->ctor(objp+obj_dbghead(cachep), | |
2325 | cachep, SLAB_CTOR_CONSTRUCTOR|SLAB_CTOR_VERIFY); | |
2326 | } | |
2327 | if (cachep->flags & SLAB_POISON && cachep->dtor) { | |
2328 | /* we want to cache poison the object, | |
2329 | * call the destruction callback | |
2330 | */ | |
2331 | cachep->dtor(objp+obj_dbghead(cachep), cachep, 0); | |
2332 | } | |
2333 | if (cachep->flags & SLAB_POISON) { | |
2334 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
2335 | if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) { | |
2336 | store_stackinfo(cachep, objp, (unsigned long)caller); | |
2337 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 0); | |
2338 | } else { | |
2339 | poison_obj(cachep, objp, POISON_FREE); | |
2340 | } | |
2341 | #else | |
2342 | poison_obj(cachep, objp, POISON_FREE); | |
2343 | #endif | |
2344 | } | |
2345 | return objp; | |
2346 | } | |
2347 | ||
2348 | static void check_slabp(kmem_cache_t *cachep, struct slab *slabp) | |
2349 | { | |
2350 | kmem_bufctl_t i; | |
2351 | int entries = 0; | |
2352 | ||
1da177e4 LT |
2353 | /* Check slab's freelist to see if this obj is there. */ |
2354 | for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { | |
2355 | entries++; | |
2356 | if (entries > cachep->num || i >= cachep->num) | |
2357 | goto bad; | |
2358 | } | |
2359 | if (entries != cachep->num - slabp->inuse) { | |
2360 | bad: | |
2361 | printk(KERN_ERR "slab: Internal list corruption detected in cache '%s'(%d), slabp %p(%d). Hexdump:\n", | |
2362 | cachep->name, cachep->num, slabp, slabp->inuse); | |
2363 | for (i=0;i<sizeof(slabp)+cachep->num*sizeof(kmem_bufctl_t);i++) { | |
2364 | if ((i%16)==0) | |
2365 | printk("\n%03x:", i); | |
2366 | printk(" %02x", ((unsigned char*)slabp)[i]); | |
2367 | } | |
2368 | printk("\n"); | |
2369 | BUG(); | |
2370 | } | |
2371 | } | |
2372 | #else | |
2373 | #define kfree_debugcheck(x) do { } while(0) | |
2374 | #define cache_free_debugcheck(x,objp,z) (objp) | |
2375 | #define check_slabp(x,y) do { } while(0) | |
2376 | #endif | |
2377 | ||
dd0fc66f | 2378 | static void *cache_alloc_refill(kmem_cache_t *cachep, gfp_t flags) |
1da177e4 LT |
2379 | { |
2380 | int batchcount; | |
2381 | struct kmem_list3 *l3; | |
2382 | struct array_cache *ac; | |
2383 | ||
2384 | check_irq_off(); | |
2385 | ac = ac_data(cachep); | |
2386 | retry: | |
2387 | batchcount = ac->batchcount; | |
2388 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { | |
2389 | /* if there was little recent activity on this | |
2390 | * cache, then perform only a partial refill. | |
2391 | * Otherwise we could generate refill bouncing. | |
2392 | */ | |
2393 | batchcount = BATCHREFILL_LIMIT; | |
2394 | } | |
e498be7d CL |
2395 | l3 = cachep->nodelists[numa_node_id()]; |
2396 | ||
2397 | BUG_ON(ac->avail > 0 || !l3); | |
2398 | spin_lock(&l3->list_lock); | |
1da177e4 | 2399 | |
1da177e4 LT |
2400 | if (l3->shared) { |
2401 | struct array_cache *shared_array = l3->shared; | |
2402 | if (shared_array->avail) { | |
2403 | if (batchcount > shared_array->avail) | |
2404 | batchcount = shared_array->avail; | |
2405 | shared_array->avail -= batchcount; | |
2406 | ac->avail = batchcount; | |
e498be7d CL |
2407 | memcpy(ac->entry, |
2408 | &(shared_array->entry[shared_array->avail]), | |
2409 | sizeof(void*)*batchcount); | |
1da177e4 LT |
2410 | shared_array->touched = 1; |
2411 | goto alloc_done; | |
2412 | } | |
2413 | } | |
2414 | while (batchcount > 0) { | |
2415 | struct list_head *entry; | |
2416 | struct slab *slabp; | |
2417 | /* Get slab alloc is to come from. */ | |
2418 | entry = l3->slabs_partial.next; | |
2419 | if (entry == &l3->slabs_partial) { | |
2420 | l3->free_touched = 1; | |
2421 | entry = l3->slabs_free.next; | |
2422 | if (entry == &l3->slabs_free) | |
2423 | goto must_grow; | |
2424 | } | |
2425 | ||
2426 | slabp = list_entry(entry, struct slab, list); | |
2427 | check_slabp(cachep, slabp); | |
2428 | check_spinlock_acquired(cachep); | |
2429 | while (slabp->inuse < cachep->num && batchcount--) { | |
2430 | kmem_bufctl_t next; | |
2431 | STATS_INC_ALLOCED(cachep); | |
2432 | STATS_INC_ACTIVE(cachep); | |
2433 | STATS_SET_HIGH(cachep); | |
2434 | ||
2435 | /* get obj pointer */ | |
e498be7d CL |
2436 | ac->entry[ac->avail++] = slabp->s_mem + |
2437 | slabp->free*cachep->objsize; | |
1da177e4 LT |
2438 | |
2439 | slabp->inuse++; | |
2440 | next = slab_bufctl(slabp)[slabp->free]; | |
2441 | #if DEBUG | |
2442 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; | |
09ad4bbc | 2443 | WARN_ON(numa_node_id() != slabp->nodeid); |
1da177e4 LT |
2444 | #endif |
2445 | slabp->free = next; | |
2446 | } | |
2447 | check_slabp(cachep, slabp); | |
2448 | ||
2449 | /* move slabp to correct slabp list: */ | |
2450 | list_del(&slabp->list); | |
2451 | if (slabp->free == BUFCTL_END) | |
2452 | list_add(&slabp->list, &l3->slabs_full); | |
2453 | else | |
2454 | list_add(&slabp->list, &l3->slabs_partial); | |
2455 | } | |
2456 | ||
2457 | must_grow: | |
2458 | l3->free_objects -= ac->avail; | |
2459 | alloc_done: | |
e498be7d | 2460 | spin_unlock(&l3->list_lock); |
1da177e4 LT |
2461 | |
2462 | if (unlikely(!ac->avail)) { | |
2463 | int x; | |
e498be7d CL |
2464 | x = cache_grow(cachep, flags, numa_node_id()); |
2465 | ||
1da177e4 LT |
2466 | // cache_grow can reenable interrupts, then ac could change. |
2467 | ac = ac_data(cachep); | |
2468 | if (!x && ac->avail == 0) // no objects in sight? abort | |
2469 | return NULL; | |
2470 | ||
2471 | if (!ac->avail) // objects refilled by interrupt? | |
2472 | goto retry; | |
2473 | } | |
2474 | ac->touched = 1; | |
e498be7d | 2475 | return ac->entry[--ac->avail]; |
1da177e4 LT |
2476 | } |
2477 | ||
2478 | static inline void | |
dd0fc66f | 2479 | cache_alloc_debugcheck_before(kmem_cache_t *cachep, gfp_t flags) |
1da177e4 LT |
2480 | { |
2481 | might_sleep_if(flags & __GFP_WAIT); | |
2482 | #if DEBUG | |
2483 | kmem_flagcheck(cachep, flags); | |
2484 | #endif | |
2485 | } | |
2486 | ||
2487 | #if DEBUG | |
2488 | static void * | |
2489 | cache_alloc_debugcheck_after(kmem_cache_t *cachep, | |
dd0fc66f | 2490 | gfp_t flags, void *objp, void *caller) |
1da177e4 LT |
2491 | { |
2492 | if (!objp) | |
2493 | return objp; | |
2494 | if (cachep->flags & SLAB_POISON) { | |
2495 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
2496 | if ((cachep->objsize % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) | |
2497 | kernel_map_pages(virt_to_page(objp), cachep->objsize/PAGE_SIZE, 1); | |
2498 | else | |
2499 | check_poison_obj(cachep, objp); | |
2500 | #else | |
2501 | check_poison_obj(cachep, objp); | |
2502 | #endif | |
2503 | poison_obj(cachep, objp, POISON_INUSE); | |
2504 | } | |
2505 | if (cachep->flags & SLAB_STORE_USER) | |
2506 | *dbg_userword(cachep, objp) = caller; | |
2507 | ||
2508 | if (cachep->flags & SLAB_RED_ZONE) { | |
2509 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || *dbg_redzone2(cachep, objp) != RED_INACTIVE) { | |
2510 | slab_error(cachep, "double free, or memory outside" | |
2511 | " object was overwritten"); | |
2512 | printk(KERN_ERR "%p: redzone 1: 0x%lx, redzone 2: 0x%lx.\n", | |
2513 | objp, *dbg_redzone1(cachep, objp), *dbg_redzone2(cachep, objp)); | |
2514 | } | |
2515 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; | |
2516 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; | |
2517 | } | |
2518 | objp += obj_dbghead(cachep); | |
2519 | if (cachep->ctor && cachep->flags & SLAB_POISON) { | |
2520 | unsigned long ctor_flags = SLAB_CTOR_CONSTRUCTOR; | |
2521 | ||
2522 | if (!(flags & __GFP_WAIT)) | |
2523 | ctor_flags |= SLAB_CTOR_ATOMIC; | |
2524 | ||
2525 | cachep->ctor(objp, cachep, ctor_flags); | |
2526 | } | |
2527 | return objp; | |
2528 | } | |
2529 | #else | |
2530 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) | |
2531 | #endif | |
2532 | ||
dd0fc66f | 2533 | static inline void *____cache_alloc(kmem_cache_t *cachep, gfp_t flags) |
1da177e4 | 2534 | { |
1da177e4 LT |
2535 | void* objp; |
2536 | struct array_cache *ac; | |
2537 | ||
5c382300 | 2538 | check_irq_off(); |
1da177e4 LT |
2539 | ac = ac_data(cachep); |
2540 | if (likely(ac->avail)) { | |
2541 | STATS_INC_ALLOCHIT(cachep); | |
2542 | ac->touched = 1; | |
e498be7d | 2543 | objp = ac->entry[--ac->avail]; |
1da177e4 LT |
2544 | } else { |
2545 | STATS_INC_ALLOCMISS(cachep); | |
2546 | objp = cache_alloc_refill(cachep, flags); | |
2547 | } | |
5c382300 AK |
2548 | return objp; |
2549 | } | |
2550 | ||
dd0fc66f | 2551 | static inline void *__cache_alloc(kmem_cache_t *cachep, gfp_t flags) |
5c382300 AK |
2552 | { |
2553 | unsigned long save_flags; | |
2554 | void* objp; | |
2555 | ||
2556 | cache_alloc_debugcheck_before(cachep, flags); | |
2557 | ||
2558 | local_irq_save(save_flags); | |
2559 | objp = ____cache_alloc(cachep, flags); | |
1da177e4 | 2560 | local_irq_restore(save_flags); |
34342e86 ED |
2561 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, |
2562 | __builtin_return_address(0)); | |
2563 | prefetchw(objp); | |
1da177e4 LT |
2564 | return objp; |
2565 | } | |
2566 | ||
e498be7d CL |
2567 | #ifdef CONFIG_NUMA |
2568 | /* | |
2569 | * A interface to enable slab creation on nodeid | |
1da177e4 | 2570 | */ |
6daa0e28 | 2571 | static void *__cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
e498be7d CL |
2572 | { |
2573 | struct list_head *entry; | |
2574 | struct slab *slabp; | |
2575 | struct kmem_list3 *l3; | |
2576 | void *obj; | |
2577 | kmem_bufctl_t next; | |
2578 | int x; | |
2579 | ||
2580 | l3 = cachep->nodelists[nodeid]; | |
2581 | BUG_ON(!l3); | |
2582 | ||
2583 | retry: | |
2584 | spin_lock(&l3->list_lock); | |
2585 | entry = l3->slabs_partial.next; | |
2586 | if (entry == &l3->slabs_partial) { | |
2587 | l3->free_touched = 1; | |
2588 | entry = l3->slabs_free.next; | |
2589 | if (entry == &l3->slabs_free) | |
2590 | goto must_grow; | |
2591 | } | |
2592 | ||
2593 | slabp = list_entry(entry, struct slab, list); | |
2594 | check_spinlock_acquired_node(cachep, nodeid); | |
2595 | check_slabp(cachep, slabp); | |
2596 | ||
2597 | STATS_INC_NODEALLOCS(cachep); | |
2598 | STATS_INC_ACTIVE(cachep); | |
2599 | STATS_SET_HIGH(cachep); | |
2600 | ||
2601 | BUG_ON(slabp->inuse == cachep->num); | |
2602 | ||
2603 | /* get obj pointer */ | |
2604 | obj = slabp->s_mem + slabp->free*cachep->objsize; | |
2605 | slabp->inuse++; | |
2606 | next = slab_bufctl(slabp)[slabp->free]; | |
2607 | #if DEBUG | |
2608 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; | |
2609 | #endif | |
2610 | slabp->free = next; | |
2611 | check_slabp(cachep, slabp); | |
2612 | l3->free_objects--; | |
2613 | /* move slabp to correct slabp list: */ | |
2614 | list_del(&slabp->list); | |
2615 | ||
2616 | if (slabp->free == BUFCTL_END) { | |
2617 | list_add(&slabp->list, &l3->slabs_full); | |
2618 | } else { | |
2619 | list_add(&slabp->list, &l3->slabs_partial); | |
2620 | } | |
2621 | ||
2622 | spin_unlock(&l3->list_lock); | |
2623 | goto done; | |
2624 | ||
2625 | must_grow: | |
2626 | spin_unlock(&l3->list_lock); | |
2627 | x = cache_grow(cachep, flags, nodeid); | |
1da177e4 | 2628 | |
e498be7d CL |
2629 | if (!x) |
2630 | return NULL; | |
2631 | ||
2632 | goto retry; | |
2633 | done: | |
2634 | return obj; | |
2635 | } | |
2636 | #endif | |
2637 | ||
2638 | /* | |
2639 | * Caller needs to acquire correct kmem_list's list_lock | |
2640 | */ | |
ff69416e | 2641 | static void free_block(kmem_cache_t *cachep, void **objpp, int nr_objects, int node) |
1da177e4 LT |
2642 | { |
2643 | int i; | |
e498be7d | 2644 | struct kmem_list3 *l3; |
1da177e4 LT |
2645 | |
2646 | for (i = 0; i < nr_objects; i++) { | |
2647 | void *objp = objpp[i]; | |
2648 | struct slab *slabp; | |
2649 | unsigned int objnr; | |
2650 | ||
065d41cb | 2651 | slabp = page_get_slab(virt_to_page(objp)); |
ff69416e | 2652 | l3 = cachep->nodelists[node]; |
1da177e4 LT |
2653 | list_del(&slabp->list); |
2654 | objnr = (objp - slabp->s_mem) / cachep->objsize; | |
ff69416e | 2655 | check_spinlock_acquired_node(cachep, node); |
1da177e4 | 2656 | check_slabp(cachep, slabp); |
e498be7d | 2657 | |
1da177e4 | 2658 | #if DEBUG |
09ad4bbc CL |
2659 | /* Verify that the slab belongs to the intended node */ |
2660 | WARN_ON(slabp->nodeid != node); | |
2661 | ||
1da177e4 | 2662 | if (slab_bufctl(slabp)[objnr] != BUFCTL_FREE) { |
e498be7d CL |
2663 | printk(KERN_ERR "slab: double free detected in cache " |
2664 | "'%s', objp %p\n", cachep->name, objp); | |
1da177e4 LT |
2665 | BUG(); |
2666 | } | |
2667 | #endif | |
2668 | slab_bufctl(slabp)[objnr] = slabp->free; | |
2669 | slabp->free = objnr; | |
2670 | STATS_DEC_ACTIVE(cachep); | |
2671 | slabp->inuse--; | |
e498be7d | 2672 | l3->free_objects++; |
1da177e4 LT |
2673 | check_slabp(cachep, slabp); |
2674 | ||
2675 | /* fixup slab chains */ | |
2676 | if (slabp->inuse == 0) { | |
e498be7d CL |
2677 | if (l3->free_objects > l3->free_limit) { |
2678 | l3->free_objects -= cachep->num; | |
1da177e4 LT |
2679 | slab_destroy(cachep, slabp); |
2680 | } else { | |
e498be7d | 2681 | list_add(&slabp->list, &l3->slabs_free); |
1da177e4 LT |
2682 | } |
2683 | } else { | |
2684 | /* Unconditionally move a slab to the end of the | |
2685 | * partial list on free - maximum time for the | |
2686 | * other objects to be freed, too. | |
2687 | */ | |
e498be7d | 2688 | list_add_tail(&slabp->list, &l3->slabs_partial); |
1da177e4 LT |
2689 | } |
2690 | } | |
2691 | } | |
2692 | ||
2693 | static void cache_flusharray(kmem_cache_t *cachep, struct array_cache *ac) | |
2694 | { | |
2695 | int batchcount; | |
e498be7d | 2696 | struct kmem_list3 *l3; |
ff69416e | 2697 | int node = numa_node_id(); |
1da177e4 LT |
2698 | |
2699 | batchcount = ac->batchcount; | |
2700 | #if DEBUG | |
2701 | BUG_ON(!batchcount || batchcount > ac->avail); | |
2702 | #endif | |
2703 | check_irq_off(); | |
ff69416e | 2704 | l3 = cachep->nodelists[node]; |
e498be7d CL |
2705 | spin_lock(&l3->list_lock); |
2706 | if (l3->shared) { | |
2707 | struct array_cache *shared_array = l3->shared; | |
1da177e4 LT |
2708 | int max = shared_array->limit-shared_array->avail; |
2709 | if (max) { | |
2710 | if (batchcount > max) | |
2711 | batchcount = max; | |
e498be7d CL |
2712 | memcpy(&(shared_array->entry[shared_array->avail]), |
2713 | ac->entry, | |
1da177e4 LT |
2714 | sizeof(void*)*batchcount); |
2715 | shared_array->avail += batchcount; | |
2716 | goto free_done; | |
2717 | } | |
2718 | } | |
2719 | ||
ff69416e | 2720 | free_block(cachep, ac->entry, batchcount, node); |
1da177e4 LT |
2721 | free_done: |
2722 | #if STATS | |
2723 | { | |
2724 | int i = 0; | |
2725 | struct list_head *p; | |
2726 | ||
e498be7d CL |
2727 | p = l3->slabs_free.next; |
2728 | while (p != &(l3->slabs_free)) { | |
1da177e4 LT |
2729 | struct slab *slabp; |
2730 | ||
2731 | slabp = list_entry(p, struct slab, list); | |
2732 | BUG_ON(slabp->inuse); | |
2733 | ||
2734 | i++; | |
2735 | p = p->next; | |
2736 | } | |
2737 | STATS_SET_FREEABLE(cachep, i); | |
2738 | } | |
2739 | #endif | |
e498be7d | 2740 | spin_unlock(&l3->list_lock); |
1da177e4 | 2741 | ac->avail -= batchcount; |
e498be7d | 2742 | memmove(ac->entry, &(ac->entry[batchcount]), |
1da177e4 LT |
2743 | sizeof(void*)*ac->avail); |
2744 | } | |
2745 | ||
e498be7d | 2746 | |
1da177e4 LT |
2747 | /* |
2748 | * __cache_free | |
2749 | * Release an obj back to its cache. If the obj has a constructed | |
2750 | * state, it must be in this state _before_ it is released. | |
2751 | * | |
2752 | * Called with disabled ints. | |
2753 | */ | |
2754 | static inline void __cache_free(kmem_cache_t *cachep, void *objp) | |
2755 | { | |
2756 | struct array_cache *ac = ac_data(cachep); | |
2757 | ||
2758 | check_irq_off(); | |
2759 | objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); | |
2760 | ||
e498be7d CL |
2761 | /* Make sure we are not freeing a object from another |
2762 | * node to the array cache on this cpu. | |
2763 | */ | |
2764 | #ifdef CONFIG_NUMA | |
2765 | { | |
2766 | struct slab *slabp; | |
065d41cb | 2767 | slabp = page_get_slab(virt_to_page(objp)); |
e498be7d CL |
2768 | if (unlikely(slabp->nodeid != numa_node_id())) { |
2769 | struct array_cache *alien = NULL; | |
2770 | int nodeid = slabp->nodeid; | |
2771 | struct kmem_list3 *l3 = cachep->nodelists[numa_node_id()]; | |
2772 | ||
2773 | STATS_INC_NODEFREES(cachep); | |
2774 | if (l3->alien && l3->alien[nodeid]) { | |
2775 | alien = l3->alien[nodeid]; | |
2776 | spin_lock(&alien->lock); | |
2777 | if (unlikely(alien->avail == alien->limit)) | |
2778 | __drain_alien_cache(cachep, | |
2779 | alien, nodeid); | |
2780 | alien->entry[alien->avail++] = objp; | |
2781 | spin_unlock(&alien->lock); | |
2782 | } else { | |
2783 | spin_lock(&(cachep->nodelists[nodeid])-> | |
2784 | list_lock); | |
ff69416e | 2785 | free_block(cachep, &objp, 1, nodeid); |
e498be7d CL |
2786 | spin_unlock(&(cachep->nodelists[nodeid])-> |
2787 | list_lock); | |
2788 | } | |
2789 | return; | |
2790 | } | |
2791 | } | |
2792 | #endif | |
1da177e4 LT |
2793 | if (likely(ac->avail < ac->limit)) { |
2794 | STATS_INC_FREEHIT(cachep); | |
e498be7d | 2795 | ac->entry[ac->avail++] = objp; |
1da177e4 LT |
2796 | return; |
2797 | } else { | |
2798 | STATS_INC_FREEMISS(cachep); | |
2799 | cache_flusharray(cachep, ac); | |
e498be7d | 2800 | ac->entry[ac->avail++] = objp; |
1da177e4 LT |
2801 | } |
2802 | } | |
2803 | ||
2804 | /** | |
2805 | * kmem_cache_alloc - Allocate an object | |
2806 | * @cachep: The cache to allocate from. | |
2807 | * @flags: See kmalloc(). | |
2808 | * | |
2809 | * Allocate an object from this cache. The flags are only relevant | |
2810 | * if the cache has no available objects. | |
2811 | */ | |
dd0fc66f | 2812 | void *kmem_cache_alloc(kmem_cache_t *cachep, gfp_t flags) |
1da177e4 LT |
2813 | { |
2814 | return __cache_alloc(cachep, flags); | |
2815 | } | |
2816 | EXPORT_SYMBOL(kmem_cache_alloc); | |
2817 | ||
2818 | /** | |
2819 | * kmem_ptr_validate - check if an untrusted pointer might | |
2820 | * be a slab entry. | |
2821 | * @cachep: the cache we're checking against | |
2822 | * @ptr: pointer to validate | |
2823 | * | |
2824 | * This verifies that the untrusted pointer looks sane: | |
2825 | * it is _not_ a guarantee that the pointer is actually | |
2826 | * part of the slab cache in question, but it at least | |
2827 | * validates that the pointer can be dereferenced and | |
2828 | * looks half-way sane. | |
2829 | * | |
2830 | * Currently only used for dentry validation. | |
2831 | */ | |
2832 | int fastcall kmem_ptr_validate(kmem_cache_t *cachep, void *ptr) | |
2833 | { | |
2834 | unsigned long addr = (unsigned long) ptr; | |
2835 | unsigned long min_addr = PAGE_OFFSET; | |
2836 | unsigned long align_mask = BYTES_PER_WORD-1; | |
2837 | unsigned long size = cachep->objsize; | |
2838 | struct page *page; | |
2839 | ||
2840 | if (unlikely(addr < min_addr)) | |
2841 | goto out; | |
2842 | if (unlikely(addr > (unsigned long)high_memory - size)) | |
2843 | goto out; | |
2844 | if (unlikely(addr & align_mask)) | |
2845 | goto out; | |
2846 | if (unlikely(!kern_addr_valid(addr))) | |
2847 | goto out; | |
2848 | if (unlikely(!kern_addr_valid(addr + size - 1))) | |
2849 | goto out; | |
2850 | page = virt_to_page(ptr); | |
2851 | if (unlikely(!PageSlab(page))) | |
2852 | goto out; | |
065d41cb | 2853 | if (unlikely(page_get_cache(page) != cachep)) |
1da177e4 LT |
2854 | goto out; |
2855 | return 1; | |
2856 | out: | |
2857 | return 0; | |
2858 | } | |
2859 | ||
2860 | #ifdef CONFIG_NUMA | |
2861 | /** | |
2862 | * kmem_cache_alloc_node - Allocate an object on the specified node | |
2863 | * @cachep: The cache to allocate from. | |
2864 | * @flags: See kmalloc(). | |
2865 | * @nodeid: node number of the target node. | |
2866 | * | |
2867 | * Identical to kmem_cache_alloc, except that this function is slow | |
2868 | * and can sleep. And it will allocate memory on the given node, which | |
2869 | * can improve the performance for cpu bound structures. | |
e498be7d CL |
2870 | * New and improved: it will now make sure that the object gets |
2871 | * put on the correct node list so that there is no false sharing. | |
1da177e4 | 2872 | */ |
dd0fc66f | 2873 | void *kmem_cache_alloc_node(kmem_cache_t *cachep, gfp_t flags, int nodeid) |
1da177e4 | 2874 | { |
e498be7d CL |
2875 | unsigned long save_flags; |
2876 | void *ptr; | |
1da177e4 | 2877 | |
ff69416e | 2878 | if (nodeid == -1) |
e498be7d | 2879 | return __cache_alloc(cachep, flags); |
1da177e4 | 2880 | |
e498be7d CL |
2881 | if (unlikely(!cachep->nodelists[nodeid])) { |
2882 | /* Fall back to __cache_alloc if we run into trouble */ | |
2883 | printk(KERN_WARNING "slab: not allocating in inactive node %d for cache %s\n", nodeid, cachep->name); | |
2884 | return __cache_alloc(cachep,flags); | |
1da177e4 | 2885 | } |
1da177e4 | 2886 | |
e498be7d CL |
2887 | cache_alloc_debugcheck_before(cachep, flags); |
2888 | local_irq_save(save_flags); | |
5c382300 AK |
2889 | if (nodeid == numa_node_id()) |
2890 | ptr = ____cache_alloc(cachep, flags); | |
2891 | else | |
2892 | ptr = __cache_alloc_node(cachep, flags, nodeid); | |
e498be7d CL |
2893 | local_irq_restore(save_flags); |
2894 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, __builtin_return_address(0)); | |
1da177e4 | 2895 | |
e498be7d | 2896 | return ptr; |
1da177e4 LT |
2897 | } |
2898 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
2899 | ||
dd0fc66f | 2900 | void *kmalloc_node(size_t size, gfp_t flags, int node) |
97e2bde4 MS |
2901 | { |
2902 | kmem_cache_t *cachep; | |
2903 | ||
2904 | cachep = kmem_find_general_cachep(size, flags); | |
2905 | if (unlikely(cachep == NULL)) | |
2906 | return NULL; | |
2907 | return kmem_cache_alloc_node(cachep, flags, node); | |
2908 | } | |
2909 | EXPORT_SYMBOL(kmalloc_node); | |
1da177e4 LT |
2910 | #endif |
2911 | ||
2912 | /** | |
2913 | * kmalloc - allocate memory | |
2914 | * @size: how many bytes of memory are required. | |
2915 | * @flags: the type of memory to allocate. | |
2916 | * | |
2917 | * kmalloc is the normal method of allocating memory | |
2918 | * in the kernel. | |
2919 | * | |
2920 | * The @flags argument may be one of: | |
2921 | * | |
2922 | * %GFP_USER - Allocate memory on behalf of user. May sleep. | |
2923 | * | |
2924 | * %GFP_KERNEL - Allocate normal kernel ram. May sleep. | |
2925 | * | |
2926 | * %GFP_ATOMIC - Allocation will not sleep. Use inside interrupt handlers. | |
2927 | * | |
2928 | * Additionally, the %GFP_DMA flag may be set to indicate the memory | |
2929 | * must be suitable for DMA. This can mean different things on different | |
2930 | * platforms. For example, on i386, it means that the memory must come | |
2931 | * from the first 16MB. | |
2932 | */ | |
dd0fc66f | 2933 | void *__kmalloc(size_t size, gfp_t flags) |
1da177e4 LT |
2934 | { |
2935 | kmem_cache_t *cachep; | |
2936 | ||
97e2bde4 MS |
2937 | /* If you want to save a few bytes .text space: replace |
2938 | * __ with kmem_. | |
2939 | * Then kmalloc uses the uninlined functions instead of the inline | |
2940 | * functions. | |
2941 | */ | |
2942 | cachep = __find_general_cachep(size, flags); | |
dbdb9045 AM |
2943 | if (unlikely(cachep == NULL)) |
2944 | return NULL; | |
1da177e4 LT |
2945 | return __cache_alloc(cachep, flags); |
2946 | } | |
2947 | EXPORT_SYMBOL(__kmalloc); | |
2948 | ||
2949 | #ifdef CONFIG_SMP | |
2950 | /** | |
2951 | * __alloc_percpu - allocate one copy of the object for every present | |
2952 | * cpu in the system, zeroing them. | |
2953 | * Objects should be dereferenced using the per_cpu_ptr macro only. | |
2954 | * | |
2955 | * @size: how many bytes of memory are required. | |
1da177e4 | 2956 | */ |
f9f75005 | 2957 | void *__alloc_percpu(size_t size) |
1da177e4 LT |
2958 | { |
2959 | int i; | |
2960 | struct percpu_data *pdata = kmalloc(sizeof (*pdata), GFP_KERNEL); | |
2961 | ||
2962 | if (!pdata) | |
2963 | return NULL; | |
2964 | ||
e498be7d CL |
2965 | /* |
2966 | * Cannot use for_each_online_cpu since a cpu may come online | |
2967 | * and we have no way of figuring out how to fix the array | |
2968 | * that we have allocated then.... | |
2969 | */ | |
2970 | for_each_cpu(i) { | |
2971 | int node = cpu_to_node(i); | |
2972 | ||
2973 | if (node_online(node)) | |
2974 | pdata->ptrs[i] = kmalloc_node(size, GFP_KERNEL, node); | |
2975 | else | |
2976 | pdata->ptrs[i] = kmalloc(size, GFP_KERNEL); | |
1da177e4 LT |
2977 | |
2978 | if (!pdata->ptrs[i]) | |
2979 | goto unwind_oom; | |
2980 | memset(pdata->ptrs[i], 0, size); | |
2981 | } | |
2982 | ||
2983 | /* Catch derefs w/o wrappers */ | |
2984 | return (void *) (~(unsigned long) pdata); | |
2985 | ||
2986 | unwind_oom: | |
2987 | while (--i >= 0) { | |
2988 | if (!cpu_possible(i)) | |
2989 | continue; | |
2990 | kfree(pdata->ptrs[i]); | |
2991 | } | |
2992 | kfree(pdata); | |
2993 | return NULL; | |
2994 | } | |
2995 | EXPORT_SYMBOL(__alloc_percpu); | |
2996 | #endif | |
2997 | ||
2998 | /** | |
2999 | * kmem_cache_free - Deallocate an object | |
3000 | * @cachep: The cache the allocation was from. | |
3001 | * @objp: The previously allocated object. | |
3002 | * | |
3003 | * Free an object which was previously allocated from this | |
3004 | * cache. | |
3005 | */ | |
3006 | void kmem_cache_free(kmem_cache_t *cachep, void *objp) | |
3007 | { | |
3008 | unsigned long flags; | |
3009 | ||
3010 | local_irq_save(flags); | |
3011 | __cache_free(cachep, objp); | |
3012 | local_irq_restore(flags); | |
3013 | } | |
3014 | EXPORT_SYMBOL(kmem_cache_free); | |
3015 | ||
3016 | /** | |
dd392710 PE |
3017 | * kzalloc - allocate memory. The memory is set to zero. |
3018 | * @size: how many bytes of memory are required. | |
1da177e4 LT |
3019 | * @flags: the type of memory to allocate. |
3020 | */ | |
dd0fc66f | 3021 | void *kzalloc(size_t size, gfp_t flags) |
1da177e4 | 3022 | { |
dd392710 | 3023 | void *ret = kmalloc(size, flags); |
1da177e4 | 3024 | if (ret) |
dd392710 | 3025 | memset(ret, 0, size); |
1da177e4 LT |
3026 | return ret; |
3027 | } | |
dd392710 | 3028 | EXPORT_SYMBOL(kzalloc); |
1da177e4 LT |
3029 | |
3030 | /** | |
3031 | * kfree - free previously allocated memory | |
3032 | * @objp: pointer returned by kmalloc. | |
3033 | * | |
80e93eff PE |
3034 | * If @objp is NULL, no operation is performed. |
3035 | * | |
1da177e4 LT |
3036 | * Don't free memory not originally allocated by kmalloc() |
3037 | * or you will run into trouble. | |
3038 | */ | |
3039 | void kfree(const void *objp) | |
3040 | { | |
3041 | kmem_cache_t *c; | |
3042 | unsigned long flags; | |
3043 | ||
3044 | if (unlikely(!objp)) | |
3045 | return; | |
3046 | local_irq_save(flags); | |
3047 | kfree_debugcheck(objp); | |
065d41cb | 3048 | c = page_get_cache(virt_to_page(objp)); |
1da177e4 LT |
3049 | __cache_free(c, (void*)objp); |
3050 | local_irq_restore(flags); | |
3051 | } | |
3052 | EXPORT_SYMBOL(kfree); | |
3053 | ||
3054 | #ifdef CONFIG_SMP | |
3055 | /** | |
3056 | * free_percpu - free previously allocated percpu memory | |
3057 | * @objp: pointer returned by alloc_percpu. | |
3058 | * | |
3059 | * Don't free memory not originally allocated by alloc_percpu() | |
3060 | * The complemented objp is to check for that. | |
3061 | */ | |
3062 | void | |
3063 | free_percpu(const void *objp) | |
3064 | { | |
3065 | int i; | |
3066 | struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp); | |
3067 | ||
e498be7d CL |
3068 | /* |
3069 | * We allocate for all cpus so we cannot use for online cpu here. | |
3070 | */ | |
3071 | for_each_cpu(i) | |
1da177e4 | 3072 | kfree(p->ptrs[i]); |
1da177e4 LT |
3073 | kfree(p); |
3074 | } | |
3075 | EXPORT_SYMBOL(free_percpu); | |
3076 | #endif | |
3077 | ||
3078 | unsigned int kmem_cache_size(kmem_cache_t *cachep) | |
3079 | { | |
3080 | return obj_reallen(cachep); | |
3081 | } | |
3082 | EXPORT_SYMBOL(kmem_cache_size); | |
3083 | ||
1944972d ACM |
3084 | const char *kmem_cache_name(kmem_cache_t *cachep) |
3085 | { | |
3086 | return cachep->name; | |
3087 | } | |
3088 | EXPORT_SYMBOL_GPL(kmem_cache_name); | |
3089 | ||
e498be7d CL |
3090 | /* |
3091 | * This initializes kmem_list3 for all nodes. | |
3092 | */ | |
3093 | static int alloc_kmemlist(kmem_cache_t *cachep) | |
3094 | { | |
3095 | int node; | |
3096 | struct kmem_list3 *l3; | |
3097 | int err = 0; | |
3098 | ||
3099 | for_each_online_node(node) { | |
3100 | struct array_cache *nc = NULL, *new; | |
3101 | struct array_cache **new_alien = NULL; | |
3102 | #ifdef CONFIG_NUMA | |
3103 | if (!(new_alien = alloc_alien_cache(node, cachep->limit))) | |
3104 | goto fail; | |
3105 | #endif | |
3106 | if (!(new = alloc_arraycache(node, (cachep->shared* | |
3107 | cachep->batchcount), 0xbaadf00d))) | |
3108 | goto fail; | |
3109 | if ((l3 = cachep->nodelists[node])) { | |
3110 | ||
3111 | spin_lock_irq(&l3->list_lock); | |
3112 | ||
3113 | if ((nc = cachep->nodelists[node]->shared)) | |
3114 | free_block(cachep, nc->entry, | |
ff69416e | 3115 | nc->avail, node); |
e498be7d CL |
3116 | |
3117 | l3->shared = new; | |
3118 | if (!cachep->nodelists[node]->alien) { | |
3119 | l3->alien = new_alien; | |
3120 | new_alien = NULL; | |
3121 | } | |
3122 | l3->free_limit = (1 + nr_cpus_node(node))* | |
3123 | cachep->batchcount + cachep->num; | |
3124 | spin_unlock_irq(&l3->list_lock); | |
3125 | kfree(nc); | |
3126 | free_alien_cache(new_alien); | |
3127 | continue; | |
3128 | } | |
3129 | if (!(l3 = kmalloc_node(sizeof(struct kmem_list3), | |
3130 | GFP_KERNEL, node))) | |
3131 | goto fail; | |
3132 | ||
3133 | kmem_list3_init(l3); | |
3134 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + | |
3135 | ((unsigned long)cachep)%REAPTIMEOUT_LIST3; | |
3136 | l3->shared = new; | |
3137 | l3->alien = new_alien; | |
3138 | l3->free_limit = (1 + nr_cpus_node(node))* | |
3139 | cachep->batchcount + cachep->num; | |
3140 | cachep->nodelists[node] = l3; | |
3141 | } | |
3142 | return err; | |
3143 | fail: | |
3144 | err = -ENOMEM; | |
3145 | return err; | |
3146 | } | |
3147 | ||
1da177e4 LT |
3148 | struct ccupdate_struct { |
3149 | kmem_cache_t *cachep; | |
3150 | struct array_cache *new[NR_CPUS]; | |
3151 | }; | |
3152 | ||
3153 | static void do_ccupdate_local(void *info) | |
3154 | { | |
3155 | struct ccupdate_struct *new = (struct ccupdate_struct *)info; | |
3156 | struct array_cache *old; | |
3157 | ||
3158 | check_irq_off(); | |
3159 | old = ac_data(new->cachep); | |
e498be7d | 3160 | |
1da177e4 LT |
3161 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; |
3162 | new->new[smp_processor_id()] = old; | |
3163 | } | |
3164 | ||
3165 | ||
3166 | static int do_tune_cpucache(kmem_cache_t *cachep, int limit, int batchcount, | |
3167 | int shared) | |
3168 | { | |
3169 | struct ccupdate_struct new; | |
e498be7d | 3170 | int i, err; |
1da177e4 LT |
3171 | |
3172 | memset(&new.new,0,sizeof(new.new)); | |
e498be7d CL |
3173 | for_each_online_cpu(i) { |
3174 | new.new[i] = alloc_arraycache(cpu_to_node(i), limit, batchcount); | |
3175 | if (!new.new[i]) { | |
3176 | for (i--; i >= 0; i--) kfree(new.new[i]); | |
3177 | return -ENOMEM; | |
1da177e4 LT |
3178 | } |
3179 | } | |
3180 | new.cachep = cachep; | |
3181 | ||
3182 | smp_call_function_all_cpus(do_ccupdate_local, (void *)&new); | |
e498be7d | 3183 | |
1da177e4 LT |
3184 | check_irq_on(); |
3185 | spin_lock_irq(&cachep->spinlock); | |
3186 | cachep->batchcount = batchcount; | |
3187 | cachep->limit = limit; | |
e498be7d | 3188 | cachep->shared = shared; |
1da177e4 LT |
3189 | spin_unlock_irq(&cachep->spinlock); |
3190 | ||
e498be7d | 3191 | for_each_online_cpu(i) { |
1da177e4 LT |
3192 | struct array_cache *ccold = new.new[i]; |
3193 | if (!ccold) | |
3194 | continue; | |
e498be7d | 3195 | spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); |
ff69416e | 3196 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i)); |
e498be7d | 3197 | spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); |
1da177e4 LT |
3198 | kfree(ccold); |
3199 | } | |
1da177e4 | 3200 | |
e498be7d CL |
3201 | err = alloc_kmemlist(cachep); |
3202 | if (err) { | |
3203 | printk(KERN_ERR "alloc_kmemlist failed for %s, error %d.\n", | |
3204 | cachep->name, -err); | |
3205 | BUG(); | |
1da177e4 | 3206 | } |
1da177e4 LT |
3207 | return 0; |
3208 | } | |
3209 | ||
3210 | ||
3211 | static void enable_cpucache(kmem_cache_t *cachep) | |
3212 | { | |
3213 | int err; | |
3214 | int limit, shared; | |
3215 | ||
3216 | /* The head array serves three purposes: | |
3217 | * - create a LIFO ordering, i.e. return objects that are cache-warm | |
3218 | * - reduce the number of spinlock operations. | |
3219 | * - reduce the number of linked list operations on the slab and | |
3220 | * bufctl chains: array operations are cheaper. | |
3221 | * The numbers are guessed, we should auto-tune as described by | |
3222 | * Bonwick. | |
3223 | */ | |
3224 | if (cachep->objsize > 131072) | |
3225 | limit = 1; | |
3226 | else if (cachep->objsize > PAGE_SIZE) | |
3227 | limit = 8; | |
3228 | else if (cachep->objsize > 1024) | |
3229 | limit = 24; | |
3230 | else if (cachep->objsize > 256) | |
3231 | limit = 54; | |
3232 | else | |
3233 | limit = 120; | |
3234 | ||
3235 | /* Cpu bound tasks (e.g. network routing) can exhibit cpu bound | |
3236 | * allocation behaviour: Most allocs on one cpu, most free operations | |
3237 | * on another cpu. For these cases, an efficient object passing between | |
3238 | * cpus is necessary. This is provided by a shared array. The array | |
3239 | * replaces Bonwick's magazine layer. | |
3240 | * On uniprocessor, it's functionally equivalent (but less efficient) | |
3241 | * to a larger limit. Thus disabled by default. | |
3242 | */ | |
3243 | shared = 0; | |
3244 | #ifdef CONFIG_SMP | |
3245 | if (cachep->objsize <= PAGE_SIZE) | |
3246 | shared = 8; | |
3247 | #endif | |
3248 | ||
3249 | #if DEBUG | |
3250 | /* With debugging enabled, large batchcount lead to excessively | |
3251 | * long periods with disabled local interrupts. Limit the | |
3252 | * batchcount | |
3253 | */ | |
3254 | if (limit > 32) | |
3255 | limit = 32; | |
3256 | #endif | |
3257 | err = do_tune_cpucache(cachep, limit, (limit+1)/2, shared); | |
3258 | if (err) | |
3259 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", | |
3260 | cachep->name, -err); | |
3261 | } | |
3262 | ||
3263 | static void drain_array_locked(kmem_cache_t *cachep, | |
e498be7d | 3264 | struct array_cache *ac, int force, int node) |
1da177e4 LT |
3265 | { |
3266 | int tofree; | |
3267 | ||
e498be7d | 3268 | check_spinlock_acquired_node(cachep, node); |
1da177e4 LT |
3269 | if (ac->touched && !force) { |
3270 | ac->touched = 0; | |
3271 | } else if (ac->avail) { | |
3272 | tofree = force ? ac->avail : (ac->limit+4)/5; | |
3273 | if (tofree > ac->avail) { | |
3274 | tofree = (ac->avail+1)/2; | |
3275 | } | |
ff69416e | 3276 | free_block(cachep, ac->entry, tofree, node); |
1da177e4 | 3277 | ac->avail -= tofree; |
e498be7d | 3278 | memmove(ac->entry, &(ac->entry[tofree]), |
1da177e4 LT |
3279 | sizeof(void*)*ac->avail); |
3280 | } | |
3281 | } | |
3282 | ||
3283 | /** | |
3284 | * cache_reap - Reclaim memory from caches. | |
1e5d5331 | 3285 | * @unused: unused parameter |
1da177e4 LT |
3286 | * |
3287 | * Called from workqueue/eventd every few seconds. | |
3288 | * Purpose: | |
3289 | * - clear the per-cpu caches for this CPU. | |
3290 | * - return freeable pages to the main free memory pool. | |
3291 | * | |
3292 | * If we cannot acquire the cache chain semaphore then just give up - we'll | |
3293 | * try again on the next iteration. | |
3294 | */ | |
3295 | static void cache_reap(void *unused) | |
3296 | { | |
3297 | struct list_head *walk; | |
e498be7d | 3298 | struct kmem_list3 *l3; |
1da177e4 LT |
3299 | |
3300 | if (down_trylock(&cache_chain_sem)) { | |
3301 | /* Give up. Setup the next iteration. */ | |
cd61ef62 | 3302 | schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC); |
1da177e4 LT |
3303 | return; |
3304 | } | |
3305 | ||
3306 | list_for_each(walk, &cache_chain) { | |
3307 | kmem_cache_t *searchp; | |
3308 | struct list_head* p; | |
3309 | int tofree; | |
3310 | struct slab *slabp; | |
3311 | ||
3312 | searchp = list_entry(walk, kmem_cache_t, next); | |
3313 | ||
3314 | if (searchp->flags & SLAB_NO_REAP) | |
3315 | goto next; | |
3316 | ||
3317 | check_irq_on(); | |
3318 | ||
e498be7d CL |
3319 | l3 = searchp->nodelists[numa_node_id()]; |
3320 | if (l3->alien) | |
3321 | drain_alien_cache(searchp, l3); | |
3322 | spin_lock_irq(&l3->list_lock); | |
1da177e4 | 3323 | |
e498be7d CL |
3324 | drain_array_locked(searchp, ac_data(searchp), 0, |
3325 | numa_node_id()); | |
1da177e4 | 3326 | |
e498be7d | 3327 | if (time_after(l3->next_reap, jiffies)) |
1da177e4 LT |
3328 | goto next_unlock; |
3329 | ||
e498be7d | 3330 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3; |
1da177e4 | 3331 | |
e498be7d CL |
3332 | if (l3->shared) |
3333 | drain_array_locked(searchp, l3->shared, 0, | |
3334 | numa_node_id()); | |
1da177e4 | 3335 | |
e498be7d CL |
3336 | if (l3->free_touched) { |
3337 | l3->free_touched = 0; | |
1da177e4 LT |
3338 | goto next_unlock; |
3339 | } | |
3340 | ||
e498be7d | 3341 | tofree = (l3->free_limit+5*searchp->num-1)/(5*searchp->num); |
1da177e4 | 3342 | do { |
e498be7d CL |
3343 | p = l3->slabs_free.next; |
3344 | if (p == &(l3->slabs_free)) | |
1da177e4 LT |
3345 | break; |
3346 | ||
3347 | slabp = list_entry(p, struct slab, list); | |
3348 | BUG_ON(slabp->inuse); | |
3349 | list_del(&slabp->list); | |
3350 | STATS_INC_REAPED(searchp); | |
3351 | ||
3352 | /* Safe to drop the lock. The slab is no longer | |
3353 | * linked to the cache. | |
3354 | * searchp cannot disappear, we hold | |
3355 | * cache_chain_lock | |
3356 | */ | |
e498be7d CL |
3357 | l3->free_objects -= searchp->num; |
3358 | spin_unlock_irq(&l3->list_lock); | |
1da177e4 | 3359 | slab_destroy(searchp, slabp); |
e498be7d | 3360 | spin_lock_irq(&l3->list_lock); |
1da177e4 LT |
3361 | } while(--tofree > 0); |
3362 | next_unlock: | |
e498be7d | 3363 | spin_unlock_irq(&l3->list_lock); |
1da177e4 LT |
3364 | next: |
3365 | cond_resched(); | |
3366 | } | |
3367 | check_irq_on(); | |
3368 | up(&cache_chain_sem); | |
4ae7c039 | 3369 | drain_remote_pages(); |
1da177e4 | 3370 | /* Setup the next iteration */ |
cd61ef62 | 3371 | schedule_delayed_work(&__get_cpu_var(reap_work), REAPTIMEOUT_CPUC); |
1da177e4 LT |
3372 | } |
3373 | ||
3374 | #ifdef CONFIG_PROC_FS | |
3375 | ||
85289f98 | 3376 | static void print_slabinfo_header(struct seq_file *m) |
1da177e4 | 3377 | { |
85289f98 PE |
3378 | /* |
3379 | * Output format version, so at least we can change it | |
3380 | * without _too_ many complaints. | |
3381 | */ | |
1da177e4 | 3382 | #if STATS |
85289f98 | 3383 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); |
1da177e4 | 3384 | #else |
85289f98 | 3385 | seq_puts(m, "slabinfo - version: 2.1\n"); |
1da177e4 | 3386 | #endif |
85289f98 PE |
3387 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " |
3388 | "<objperslab> <pagesperslab>"); | |
3389 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); | |
3390 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
1da177e4 | 3391 | #if STATS |
85289f98 PE |
3392 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " |
3393 | "<error> <maxfreeable> <nodeallocs> <remotefrees>"); | |
3394 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); | |
1da177e4 | 3395 | #endif |
85289f98 PE |
3396 | seq_putc(m, '\n'); |
3397 | } | |
3398 | ||
3399 | static void *s_start(struct seq_file *m, loff_t *pos) | |
3400 | { | |
3401 | loff_t n = *pos; | |
3402 | struct list_head *p; | |
3403 | ||
3404 | down(&cache_chain_sem); | |
3405 | if (!n) | |
3406 | print_slabinfo_header(m); | |
1da177e4 LT |
3407 | p = cache_chain.next; |
3408 | while (n--) { | |
3409 | p = p->next; | |
3410 | if (p == &cache_chain) | |
3411 | return NULL; | |
3412 | } | |
3413 | return list_entry(p, kmem_cache_t, next); | |
3414 | } | |
3415 | ||
3416 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
3417 | { | |
3418 | kmem_cache_t *cachep = p; | |
3419 | ++*pos; | |
3420 | return cachep->next.next == &cache_chain ? NULL | |
3421 | : list_entry(cachep->next.next, kmem_cache_t, next); | |
3422 | } | |
3423 | ||
3424 | static void s_stop(struct seq_file *m, void *p) | |
3425 | { | |
3426 | up(&cache_chain_sem); | |
3427 | } | |
3428 | ||
3429 | static int s_show(struct seq_file *m, void *p) | |
3430 | { | |
3431 | kmem_cache_t *cachep = p; | |
3432 | struct list_head *q; | |
3433 | struct slab *slabp; | |
3434 | unsigned long active_objs; | |
3435 | unsigned long num_objs; | |
3436 | unsigned long active_slabs = 0; | |
e498be7d CL |
3437 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; |
3438 | const char *name; | |
1da177e4 | 3439 | char *error = NULL; |
e498be7d CL |
3440 | int node; |
3441 | struct kmem_list3 *l3; | |
1da177e4 LT |
3442 | |
3443 | check_irq_on(); | |
3444 | spin_lock_irq(&cachep->spinlock); | |
3445 | active_objs = 0; | |
3446 | num_slabs = 0; | |
e498be7d CL |
3447 | for_each_online_node(node) { |
3448 | l3 = cachep->nodelists[node]; | |
3449 | if (!l3) | |
3450 | continue; | |
3451 | ||
3452 | spin_lock(&l3->list_lock); | |
3453 | ||
3454 | list_for_each(q,&l3->slabs_full) { | |
3455 | slabp = list_entry(q, struct slab, list); | |
3456 | if (slabp->inuse != cachep->num && !error) | |
3457 | error = "slabs_full accounting error"; | |
3458 | active_objs += cachep->num; | |
3459 | active_slabs++; | |
3460 | } | |
3461 | list_for_each(q,&l3->slabs_partial) { | |
3462 | slabp = list_entry(q, struct slab, list); | |
3463 | if (slabp->inuse == cachep->num && !error) | |
3464 | error = "slabs_partial inuse accounting error"; | |
3465 | if (!slabp->inuse && !error) | |
3466 | error = "slabs_partial/inuse accounting error"; | |
3467 | active_objs += slabp->inuse; | |
3468 | active_slabs++; | |
3469 | } | |
3470 | list_for_each(q,&l3->slabs_free) { | |
3471 | slabp = list_entry(q, struct slab, list); | |
3472 | if (slabp->inuse && !error) | |
3473 | error = "slabs_free/inuse accounting error"; | |
3474 | num_slabs++; | |
3475 | } | |
3476 | free_objects += l3->free_objects; | |
3477 | shared_avail += l3->shared->avail; | |
3478 | ||
3479 | spin_unlock(&l3->list_lock); | |
1da177e4 LT |
3480 | } |
3481 | num_slabs+=active_slabs; | |
3482 | num_objs = num_slabs*cachep->num; | |
e498be7d | 3483 | if (num_objs - active_objs != free_objects && !error) |
1da177e4 LT |
3484 | error = "free_objects accounting error"; |
3485 | ||
3486 | name = cachep->name; | |
3487 | if (error) | |
3488 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); | |
3489 | ||
3490 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", | |
3491 | name, active_objs, num_objs, cachep->objsize, | |
3492 | cachep->num, (1<<cachep->gfporder)); | |
3493 | seq_printf(m, " : tunables %4u %4u %4u", | |
3494 | cachep->limit, cachep->batchcount, | |
e498be7d CL |
3495 | cachep->shared); |
3496 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
3497 | active_slabs, num_slabs, shared_avail); | |
1da177e4 LT |
3498 | #if STATS |
3499 | { /* list3 stats */ | |
3500 | unsigned long high = cachep->high_mark; | |
3501 | unsigned long allocs = cachep->num_allocations; | |
3502 | unsigned long grown = cachep->grown; | |
3503 | unsigned long reaped = cachep->reaped; | |
3504 | unsigned long errors = cachep->errors; | |
3505 | unsigned long max_freeable = cachep->max_freeable; | |
1da177e4 | 3506 | unsigned long node_allocs = cachep->node_allocs; |
e498be7d | 3507 | unsigned long node_frees = cachep->node_frees; |
1da177e4 | 3508 | |
e498be7d CL |
3509 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \ |
3510 | %4lu %4lu %4lu %4lu", | |
3511 | allocs, high, grown, reaped, errors, | |
3512 | max_freeable, node_allocs, node_frees); | |
1da177e4 LT |
3513 | } |
3514 | /* cpu stats */ | |
3515 | { | |
3516 | unsigned long allochit = atomic_read(&cachep->allochit); | |
3517 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); | |
3518 | unsigned long freehit = atomic_read(&cachep->freehit); | |
3519 | unsigned long freemiss = atomic_read(&cachep->freemiss); | |
3520 | ||
3521 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", | |
3522 | allochit, allocmiss, freehit, freemiss); | |
3523 | } | |
3524 | #endif | |
3525 | seq_putc(m, '\n'); | |
3526 | spin_unlock_irq(&cachep->spinlock); | |
3527 | return 0; | |
3528 | } | |
3529 | ||
3530 | /* | |
3531 | * slabinfo_op - iterator that generates /proc/slabinfo | |
3532 | * | |
3533 | * Output layout: | |
3534 | * cache-name | |
3535 | * num-active-objs | |
3536 | * total-objs | |
3537 | * object size | |
3538 | * num-active-slabs | |
3539 | * total-slabs | |
3540 | * num-pages-per-slab | |
3541 | * + further values on SMP and with statistics enabled | |
3542 | */ | |
3543 | ||
3544 | struct seq_operations slabinfo_op = { | |
3545 | .start = s_start, | |
3546 | .next = s_next, | |
3547 | .stop = s_stop, | |
3548 | .show = s_show, | |
3549 | }; | |
3550 | ||
3551 | #define MAX_SLABINFO_WRITE 128 | |
3552 | /** | |
3553 | * slabinfo_write - Tuning for the slab allocator | |
3554 | * @file: unused | |
3555 | * @buffer: user buffer | |
3556 | * @count: data length | |
3557 | * @ppos: unused | |
3558 | */ | |
3559 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, | |
3560 | size_t count, loff_t *ppos) | |
3561 | { | |
3562 | char kbuf[MAX_SLABINFO_WRITE+1], *tmp; | |
3563 | int limit, batchcount, shared, res; | |
3564 | struct list_head *p; | |
3565 | ||
3566 | if (count > MAX_SLABINFO_WRITE) | |
3567 | return -EINVAL; | |
3568 | if (copy_from_user(&kbuf, buffer, count)) | |
3569 | return -EFAULT; | |
3570 | kbuf[MAX_SLABINFO_WRITE] = '\0'; | |
3571 | ||
3572 | tmp = strchr(kbuf, ' '); | |
3573 | if (!tmp) | |
3574 | return -EINVAL; | |
3575 | *tmp = '\0'; | |
3576 | tmp++; | |
3577 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) | |
3578 | return -EINVAL; | |
3579 | ||
3580 | /* Find the cache in the chain of caches. */ | |
3581 | down(&cache_chain_sem); | |
3582 | res = -EINVAL; | |
3583 | list_for_each(p,&cache_chain) { | |
3584 | kmem_cache_t *cachep = list_entry(p, kmem_cache_t, next); | |
3585 | ||
3586 | if (!strcmp(cachep->name, kbuf)) { | |
3587 | if (limit < 1 || | |
3588 | batchcount < 1 || | |
3589 | batchcount > limit || | |
3590 | shared < 0) { | |
e498be7d | 3591 | res = 0; |
1da177e4 | 3592 | } else { |
e498be7d CL |
3593 | res = do_tune_cpucache(cachep, limit, |
3594 | batchcount, shared); | |
1da177e4 LT |
3595 | } |
3596 | break; | |
3597 | } | |
3598 | } | |
3599 | up(&cache_chain_sem); | |
3600 | if (res >= 0) | |
3601 | res = count; | |
3602 | return res; | |
3603 | } | |
3604 | #endif | |
3605 | ||
00e145b6 MS |
3606 | /** |
3607 | * ksize - get the actual amount of memory allocated for a given object | |
3608 | * @objp: Pointer to the object | |
3609 | * | |
3610 | * kmalloc may internally round up allocations and return more memory | |
3611 | * than requested. ksize() can be used to determine the actual amount of | |
3612 | * memory allocated. The caller may use this additional memory, even though | |
3613 | * a smaller amount of memory was initially specified with the kmalloc call. | |
3614 | * The caller must guarantee that objp points to a valid object previously | |
3615 | * allocated with either kmalloc() or kmem_cache_alloc(). The object | |
3616 | * must not be freed during the duration of the call. | |
3617 | */ | |
1da177e4 LT |
3618 | unsigned int ksize(const void *objp) |
3619 | { | |
00e145b6 MS |
3620 | if (unlikely(objp == NULL)) |
3621 | return 0; | |
1da177e4 | 3622 | |
065d41cb | 3623 | return obj_reallen(page_get_cache(virt_to_page(objp))); |
1da177e4 | 3624 | } |
543537bd PM |
3625 | |
3626 | ||
3627 | /* | |
3628 | * kstrdup - allocate space for and copy an existing string | |
3629 | * | |
3630 | * @s: the string to duplicate | |
3631 | * @gfp: the GFP mask used in the kmalloc() call when allocating memory | |
3632 | */ | |
dd0fc66f | 3633 | char *kstrdup(const char *s, gfp_t gfp) |
543537bd PM |
3634 | { |
3635 | size_t len; | |
3636 | char *buf; | |
3637 | ||
3638 | if (!s) | |
3639 | return NULL; | |
3640 | ||
3641 | len = strlen(s) + 1; | |
3642 | buf = kmalloc(len, gfp); | |
3643 | if (buf) | |
3644 | memcpy(buf, s, len); | |
3645 | return buf; | |
3646 | } | |
3647 | EXPORT_SYMBOL(kstrdup); |