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1 | /* | |
2 | * linux/mm/slab.c | |
3 | * Written by Mark Hemment, 1996/97. | |
4 | * (markhe@nextd.demon.co.uk) | |
5 | * | |
6 | * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli | |
7 | * | |
8 | * Major cleanup, different bufctl logic, per-cpu arrays | |
9 | * (c) 2000 Manfred Spraul | |
10 | * | |
11 | * Cleanup, make the head arrays unconditional, preparation for NUMA | |
12 | * (c) 2002 Manfred Spraul | |
13 | * | |
14 | * An implementation of the Slab Allocator as described in outline in; | |
15 | * UNIX Internals: The New Frontiers by Uresh Vahalia | |
16 | * Pub: Prentice Hall ISBN 0-13-101908-2 | |
17 | * or with a little more detail in; | |
18 | * The Slab Allocator: An Object-Caching Kernel Memory Allocator | |
19 | * Jeff Bonwick (Sun Microsystems). | |
20 | * Presented at: USENIX Summer 1994 Technical Conference | |
21 | * | |
22 | * The memory is organized in caches, one cache for each object type. | |
23 | * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) | |
24 | * Each cache consists out of many slabs (they are small (usually one | |
25 | * page long) and always contiguous), and each slab contains multiple | |
26 | * initialized objects. | |
27 | * | |
28 | * This means, that your constructor is used only for newly allocated | |
29 | * slabs and you must pass objects with the same 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 struct kmem_cache and struct slab never change, they | |
59 | * are accessed without any locking. | |
60 | * The per-cpu arrays are never accessed from the wrong cpu, no locking, | |
61 | * and local interrupts are disabled so slab code is preempt-safe. | |
62 | * The non-constant members are protected with a per-cache irq spinlock. | |
63 | * | |
64 | * Many thanks to Mark Hemment, who wrote another per-cpu slab patch | |
65 | * in 2000 - many ideas in the current implementation are derived from | |
66 | * his patch. | |
67 | * | |
68 | * Further notes from the original documentation: | |
69 | * | |
70 | * 11 April '97. Started multi-threading - markhe | |
71 | * The global cache-chain is protected by the mutex 'cache_chain_mutex'. | |
72 | * The sem is only needed when accessing/extending the cache-chain, which | |
73 | * can never happen inside an interrupt (kmem_cache_create(), | |
74 | * kmem_cache_shrink() and kmem_cache_reap()). | |
75 | * | |
76 | * At present, each engine can be growing a cache. This should be blocked. | |
77 | * | |
78 | * 15 March 2005. NUMA slab allocator. | |
79 | * Shai Fultheim <shai@scalex86.org>. | |
80 | * Shobhit Dayal <shobhit@calsoftinc.com> | |
81 | * Alok N Kataria <alokk@calsoftinc.com> | |
82 | * Christoph Lameter <christoph@lameter.com> | |
83 | * | |
84 | * Modified the slab allocator to be node aware on NUMA systems. | |
85 | * Each node has its own list of partial, free and full slabs. | |
86 | * All object allocations for a node occur from node specific slab lists. | |
87 | */ | |
88 | ||
89 | #include <linux/slab.h> | |
90 | #include <linux/mm.h> | |
91 | #include <linux/poison.h> | |
92 | #include <linux/swap.h> | |
93 | #include <linux/cache.h> | |
94 | #include <linux/interrupt.h> | |
95 | #include <linux/init.h> | |
96 | #include <linux/compiler.h> | |
97 | #include <linux/cpuset.h> | |
98 | #include <linux/seq_file.h> | |
99 | #include <linux/notifier.h> | |
100 | #include <linux/kallsyms.h> | |
101 | #include <linux/cpu.h> | |
102 | #include <linux/sysctl.h> | |
103 | #include <linux/module.h> | |
104 | #include <linux/rcupdate.h> | |
105 | #include <linux/string.h> | |
106 | #include <linux/uaccess.h> | |
107 | #include <linux/nodemask.h> | |
108 | #include <linux/mempolicy.h> | |
109 | #include <linux/mutex.h> | |
110 | #include <linux/fault-inject.h> | |
111 | #include <linux/rtmutex.h> | |
112 | #include <linux/reciprocal_div.h> | |
113 | ||
114 | #include <asm/cacheflush.h> | |
115 | #include <asm/tlbflush.h> | |
116 | #include <asm/page.h> | |
117 | ||
118 | /* | |
119 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. | |
120 | * 0 for faster, smaller code (especially in the critical paths). | |
121 | * | |
122 | * STATS - 1 to collect stats for /proc/slabinfo. | |
123 | * 0 for faster, smaller code (especially in the critical paths). | |
124 | * | |
125 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) | |
126 | */ | |
127 | ||
128 | #ifdef CONFIG_DEBUG_SLAB | |
129 | #define DEBUG 1 | |
130 | #define STATS 1 | |
131 | #define FORCED_DEBUG 1 | |
132 | #else | |
133 | #define DEBUG 0 | |
134 | #define STATS 0 | |
135 | #define FORCED_DEBUG 0 | |
136 | #endif | |
137 | ||
138 | /* Shouldn't this be in a header file somewhere? */ | |
139 | #define BYTES_PER_WORD sizeof(void *) | |
140 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) | |
141 | ||
142 | #ifndef cache_line_size | |
143 | #define cache_line_size() L1_CACHE_BYTES | |
144 | #endif | |
145 | ||
146 | #ifndef ARCH_KMALLOC_MINALIGN | |
147 | /* | |
148 | * Enforce a minimum alignment for the kmalloc caches. | |
149 | * Usually, the kmalloc caches are cache_line_size() aligned, except when | |
150 | * DEBUG and FORCED_DEBUG are enabled, then they are BYTES_PER_WORD aligned. | |
151 | * Some archs want to perform DMA into kmalloc caches and need a guaranteed | |
152 | * alignment larger than the alignment of a 64-bit integer. | |
153 | * ARCH_KMALLOC_MINALIGN allows that. | |
154 | * Note that increasing this value may disable some debug features. | |
155 | */ | |
156 | #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long) | |
157 | #endif | |
158 | ||
159 | #ifndef ARCH_SLAB_MINALIGN | |
160 | /* | |
161 | * Enforce a minimum alignment for all caches. | |
162 | * Intended for archs that get misalignment faults even for BYTES_PER_WORD | |
163 | * aligned buffers. Includes ARCH_KMALLOC_MINALIGN. | |
164 | * If possible: Do not enable this flag for CONFIG_DEBUG_SLAB, it disables | |
165 | * some debug features. | |
166 | */ | |
167 | #define ARCH_SLAB_MINALIGN 0 | |
168 | #endif | |
169 | ||
170 | #ifndef ARCH_KMALLOC_FLAGS | |
171 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN | |
172 | #endif | |
173 | ||
174 | /* Legal flag mask for kmem_cache_create(). */ | |
175 | #if DEBUG | |
176 | # define CREATE_MASK (SLAB_RED_ZONE | \ | |
177 | SLAB_POISON | SLAB_HWCACHE_ALIGN | \ | |
178 | SLAB_CACHE_DMA | \ | |
179 | SLAB_STORE_USER | \ | |
180 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | |
181 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD) | |
182 | #else | |
183 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ | |
184 | SLAB_CACHE_DMA | \ | |
185 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | |
186 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD) | |
187 | #endif | |
188 | ||
189 | /* | |
190 | * kmem_bufctl_t: | |
191 | * | |
192 | * Bufctl's are used for linking objs within a slab | |
193 | * linked offsets. | |
194 | * | |
195 | * This implementation relies on "struct page" for locating the cache & | |
196 | * slab an object belongs to. | |
197 | * This allows the bufctl structure to be small (one int), but limits | |
198 | * the number of objects a slab (not a cache) can contain when off-slab | |
199 | * bufctls are used. The limit is the size of the largest general cache | |
200 | * that does not use off-slab slabs. | |
201 | * For 32bit archs with 4 kB pages, is this 56. | |
202 | * This is not serious, as it is only for large objects, when it is unwise | |
203 | * to have too many per slab. | |
204 | * Note: This limit can be raised by introducing a general cache whose size | |
205 | * is less than 512 (PAGE_SIZE<<3), but greater than 256. | |
206 | */ | |
207 | ||
208 | typedef unsigned int kmem_bufctl_t; | |
209 | #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) | |
210 | #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) | |
211 | #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) | |
212 | #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) | |
213 | ||
214 | /* | |
215 | * struct slab | |
216 | * | |
217 | * Manages the objs in a slab. Placed either at the beginning of mem allocated | |
218 | * for a slab, or allocated from an general cache. | |
219 | * Slabs are chained into three list: fully used, partial, fully free slabs. | |
220 | */ | |
221 | struct slab { | |
222 | struct list_head list; | |
223 | unsigned long colouroff; | |
224 | void *s_mem; /* including colour offset */ | |
225 | unsigned int inuse; /* num of objs active in slab */ | |
226 | kmem_bufctl_t free; | |
227 | unsigned short nodeid; | |
228 | }; | |
229 | ||
230 | /* | |
231 | * struct slab_rcu | |
232 | * | |
233 | * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to | |
234 | * arrange for kmem_freepages to be called via RCU. This is useful if | |
235 | * we need to approach a kernel structure obliquely, from its address | |
236 | * obtained without the usual locking. We can lock the structure to | |
237 | * stabilize it and check it's still at the given address, only if we | |
238 | * can be sure that the memory has not been meanwhile reused for some | |
239 | * other kind of object (which our subsystem's lock might corrupt). | |
240 | * | |
241 | * rcu_read_lock before reading the address, then rcu_read_unlock after | |
242 | * taking the spinlock within the structure expected at that address. | |
243 | * | |
244 | * We assume struct slab_rcu can overlay struct slab when destroying. | |
245 | */ | |
246 | struct slab_rcu { | |
247 | struct rcu_head head; | |
248 | struct kmem_cache *cachep; | |
249 | void *addr; | |
250 | }; | |
251 | ||
252 | /* | |
253 | * struct array_cache | |
254 | * | |
255 | * Purpose: | |
256 | * - LIFO ordering, to hand out cache-warm objects from _alloc | |
257 | * - reduce the number of linked list operations | |
258 | * - reduce spinlock operations | |
259 | * | |
260 | * The limit is stored in the per-cpu structure to reduce the data cache | |
261 | * footprint. | |
262 | * | |
263 | */ | |
264 | struct array_cache { | |
265 | unsigned int avail; | |
266 | unsigned int limit; | |
267 | unsigned int batchcount; | |
268 | unsigned int touched; | |
269 | spinlock_t lock; | |
270 | void *entry[0]; /* | |
271 | * Must have this definition in here for the proper | |
272 | * alignment of array_cache. Also simplifies accessing | |
273 | * the entries. | |
274 | * [0] is for gcc 2.95. It should really be []. | |
275 | */ | |
276 | }; | |
277 | ||
278 | /* | |
279 | * bootstrap: The caches do not work without cpuarrays anymore, but the | |
280 | * cpuarrays are allocated from the generic caches... | |
281 | */ | |
282 | #define BOOT_CPUCACHE_ENTRIES 1 | |
283 | struct arraycache_init { | |
284 | struct array_cache cache; | |
285 | void *entries[BOOT_CPUCACHE_ENTRIES]; | |
286 | }; | |
287 | ||
288 | /* | |
289 | * The slab lists for all objects. | |
290 | */ | |
291 | struct kmem_list3 { | |
292 | struct list_head slabs_partial; /* partial list first, better asm code */ | |
293 | struct list_head slabs_full; | |
294 | struct list_head slabs_free; | |
295 | unsigned long free_objects; | |
296 | unsigned int free_limit; | |
297 | unsigned int colour_next; /* Per-node cache coloring */ | |
298 | spinlock_t list_lock; | |
299 | struct array_cache *shared; /* shared per node */ | |
300 | struct array_cache **alien; /* on other nodes */ | |
301 | unsigned long next_reap; /* updated without locking */ | |
302 | int free_touched; /* updated without locking */ | |
303 | }; | |
304 | ||
305 | /* | |
306 | * Need this for bootstrapping a per node allocator. | |
307 | */ | |
308 | #define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1) | |
309 | struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; | |
310 | #define CACHE_CACHE 0 | |
311 | #define SIZE_AC 1 | |
312 | #define SIZE_L3 (1 + MAX_NUMNODES) | |
313 | ||
314 | static int drain_freelist(struct kmem_cache *cache, | |
315 | struct kmem_list3 *l3, int tofree); | |
316 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, | |
317 | int node); | |
318 | static int enable_cpucache(struct kmem_cache *cachep); | |
319 | static void cache_reap(struct work_struct *unused); | |
320 | ||
321 | /* | |
322 | * This function must be completely optimized away if a constant is passed to | |
323 | * it. Mostly the same as what is in linux/slab.h except it returns an index. | |
324 | */ | |
325 | static __always_inline int index_of(const size_t size) | |
326 | { | |
327 | extern void __bad_size(void); | |
328 | ||
329 | if (__builtin_constant_p(size)) { | |
330 | int i = 0; | |
331 | ||
332 | #define CACHE(x) \ | |
333 | if (size <=x) \ | |
334 | return i; \ | |
335 | else \ | |
336 | i++; | |
337 | #include "linux/kmalloc_sizes.h" | |
338 | #undef CACHE | |
339 | __bad_size(); | |
340 | } else | |
341 | __bad_size(); | |
342 | return 0; | |
343 | } | |
344 | ||
345 | static int slab_early_init = 1; | |
346 | ||
347 | #define INDEX_AC index_of(sizeof(struct arraycache_init)) | |
348 | #define INDEX_L3 index_of(sizeof(struct kmem_list3)) | |
349 | ||
350 | static void kmem_list3_init(struct kmem_list3 *parent) | |
351 | { | |
352 | INIT_LIST_HEAD(&parent->slabs_full); | |
353 | INIT_LIST_HEAD(&parent->slabs_partial); | |
354 | INIT_LIST_HEAD(&parent->slabs_free); | |
355 | parent->shared = NULL; | |
356 | parent->alien = NULL; | |
357 | parent->colour_next = 0; | |
358 | spin_lock_init(&parent->list_lock); | |
359 | parent->free_objects = 0; | |
360 | parent->free_touched = 0; | |
361 | } | |
362 | ||
363 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ | |
364 | do { \ | |
365 | INIT_LIST_HEAD(listp); \ | |
366 | list_splice(&(cachep->nodelists[nodeid]->slab), listp); \ | |
367 | } while (0) | |
368 | ||
369 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ | |
370 | do { \ | |
371 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ | |
372 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ | |
373 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ | |
374 | } while (0) | |
375 | ||
376 | /* | |
377 | * struct kmem_cache | |
378 | * | |
379 | * manages a cache. | |
380 | */ | |
381 | ||
382 | struct kmem_cache { | |
383 | /* 1) per-cpu data, touched during every alloc/free */ | |
384 | struct array_cache *array[NR_CPUS]; | |
385 | /* 2) Cache tunables. Protected by cache_chain_mutex */ | |
386 | unsigned int batchcount; | |
387 | unsigned int limit; | |
388 | unsigned int shared; | |
389 | ||
390 | unsigned int buffer_size; | |
391 | u32 reciprocal_buffer_size; | |
392 | /* 3) touched by every alloc & free from the backend */ | |
393 | ||
394 | unsigned int flags; /* constant flags */ | |
395 | unsigned int num; /* # of objs per slab */ | |
396 | ||
397 | /* 4) cache_grow/shrink */ | |
398 | /* order of pgs per slab (2^n) */ | |
399 | unsigned int gfporder; | |
400 | ||
401 | /* force GFP flags, e.g. GFP_DMA */ | |
402 | gfp_t gfpflags; | |
403 | ||
404 | size_t colour; /* cache colouring range */ | |
405 | unsigned int colour_off; /* colour offset */ | |
406 | struct kmem_cache *slabp_cache; | |
407 | unsigned int slab_size; | |
408 | unsigned int dflags; /* dynamic flags */ | |
409 | ||
410 | /* constructor func */ | |
411 | void (*ctor) (void *, struct kmem_cache *, unsigned long); | |
412 | ||
413 | /* 5) cache creation/removal */ | |
414 | const char *name; | |
415 | struct list_head next; | |
416 | ||
417 | /* 6) statistics */ | |
418 | #if STATS | |
419 | unsigned long num_active; | |
420 | unsigned long num_allocations; | |
421 | unsigned long high_mark; | |
422 | unsigned long grown; | |
423 | unsigned long reaped; | |
424 | unsigned long errors; | |
425 | unsigned long max_freeable; | |
426 | unsigned long node_allocs; | |
427 | unsigned long node_frees; | |
428 | unsigned long node_overflow; | |
429 | atomic_t allochit; | |
430 | atomic_t allocmiss; | |
431 | atomic_t freehit; | |
432 | atomic_t freemiss; | |
433 | #endif | |
434 | #if DEBUG | |
435 | /* | |
436 | * If debugging is enabled, then the allocator can add additional | |
437 | * fields and/or padding to every object. buffer_size contains the total | |
438 | * object size including these internal fields, the following two | |
439 | * variables contain the offset to the user object and its size. | |
440 | */ | |
441 | int obj_offset; | |
442 | int obj_size; | |
443 | #endif | |
444 | /* | |
445 | * We put nodelists[] at the end of kmem_cache, because we want to size | |
446 | * this array to nr_node_ids slots instead of MAX_NUMNODES | |
447 | * (see kmem_cache_init()) | |
448 | * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache | |
449 | * is statically defined, so we reserve the max number of nodes. | |
450 | */ | |
451 | struct kmem_list3 *nodelists[MAX_NUMNODES]; | |
452 | /* | |
453 | * Do not add fields after nodelists[] | |
454 | */ | |
455 | }; | |
456 | ||
457 | #define CFLGS_OFF_SLAB (0x80000000UL) | |
458 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) | |
459 | ||
460 | #define BATCHREFILL_LIMIT 16 | |
461 | /* | |
462 | * Optimization question: fewer reaps means less probability for unnessary | |
463 | * cpucache drain/refill cycles. | |
464 | * | |
465 | * OTOH the cpuarrays can contain lots of objects, | |
466 | * which could lock up otherwise freeable slabs. | |
467 | */ | |
468 | #define REAPTIMEOUT_CPUC (2*HZ) | |
469 | #define REAPTIMEOUT_LIST3 (4*HZ) | |
470 | ||
471 | #if STATS | |
472 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) | |
473 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) | |
474 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) | |
475 | #define STATS_INC_GROWN(x) ((x)->grown++) | |
476 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) | |
477 | #define STATS_SET_HIGH(x) \ | |
478 | do { \ | |
479 | if ((x)->num_active > (x)->high_mark) \ | |
480 | (x)->high_mark = (x)->num_active; \ | |
481 | } while (0) | |
482 | #define STATS_INC_ERR(x) ((x)->errors++) | |
483 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) | |
484 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) | |
485 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) | |
486 | #define STATS_SET_FREEABLE(x, i) \ | |
487 | do { \ | |
488 | if ((x)->max_freeable < i) \ | |
489 | (x)->max_freeable = i; \ | |
490 | } while (0) | |
491 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) | |
492 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) | |
493 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) | |
494 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) | |
495 | #else | |
496 | #define STATS_INC_ACTIVE(x) do { } while (0) | |
497 | #define STATS_DEC_ACTIVE(x) do { } while (0) | |
498 | #define STATS_INC_ALLOCED(x) do { } while (0) | |
499 | #define STATS_INC_GROWN(x) do { } while (0) | |
500 | #define STATS_ADD_REAPED(x,y) do { } while (0) | |
501 | #define STATS_SET_HIGH(x) do { } while (0) | |
502 | #define STATS_INC_ERR(x) do { } while (0) | |
503 | #define STATS_INC_NODEALLOCS(x) do { } while (0) | |
504 | #define STATS_INC_NODEFREES(x) do { } while (0) | |
505 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) | |
506 | #define STATS_SET_FREEABLE(x, i) do { } while (0) | |
507 | #define STATS_INC_ALLOCHIT(x) do { } while (0) | |
508 | #define STATS_INC_ALLOCMISS(x) do { } while (0) | |
509 | #define STATS_INC_FREEHIT(x) do { } while (0) | |
510 | #define STATS_INC_FREEMISS(x) do { } while (0) | |
511 | #endif | |
512 | ||
513 | #if DEBUG | |
514 | ||
515 | /* | |
516 | * memory layout of objects: | |
517 | * 0 : objp | |
518 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that | |
519 | * the end of an object is aligned with the end of the real | |
520 | * allocation. Catches writes behind the end of the allocation. | |
521 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: | |
522 | * redzone word. | |
523 | * cachep->obj_offset: The real object. | |
524 | * cachep->buffer_size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] | |
525 | * cachep->buffer_size - 1* BYTES_PER_WORD: last caller address | |
526 | * [BYTES_PER_WORD long] | |
527 | */ | |
528 | static int obj_offset(struct kmem_cache *cachep) | |
529 | { | |
530 | return cachep->obj_offset; | |
531 | } | |
532 | ||
533 | static int obj_size(struct kmem_cache *cachep) | |
534 | { | |
535 | return cachep->obj_size; | |
536 | } | |
537 | ||
538 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) | |
539 | { | |
540 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
541 | return (unsigned long long*) (objp + obj_offset(cachep) - | |
542 | sizeof(unsigned long long)); | |
543 | } | |
544 | ||
545 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) | |
546 | { | |
547 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
548 | if (cachep->flags & SLAB_STORE_USER) | |
549 | return (unsigned long long *)(objp + cachep->buffer_size - | |
550 | sizeof(unsigned long long) - | |
551 | REDZONE_ALIGN); | |
552 | return (unsigned long long *) (objp + cachep->buffer_size - | |
553 | sizeof(unsigned long long)); | |
554 | } | |
555 | ||
556 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) | |
557 | { | |
558 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); | |
559 | return (void **)(objp + cachep->buffer_size - BYTES_PER_WORD); | |
560 | } | |
561 | ||
562 | #else | |
563 | ||
564 | #define obj_offset(x) 0 | |
565 | #define obj_size(cachep) (cachep->buffer_size) | |
566 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
567 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
568 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) | |
569 | ||
570 | #endif | |
571 | ||
572 | /* | |
573 | * Do not go above this order unless 0 objects fit into the slab. | |
574 | */ | |
575 | #define BREAK_GFP_ORDER_HI 1 | |
576 | #define BREAK_GFP_ORDER_LO 0 | |
577 | static int slab_break_gfp_order = BREAK_GFP_ORDER_LO; | |
578 | ||
579 | /* | |
580 | * Functions for storing/retrieving the cachep and or slab from the page | |
581 | * allocator. These are used to find the slab an obj belongs to. With kfree(), | |
582 | * these are used to find the cache which an obj belongs to. | |
583 | */ | |
584 | static inline void page_set_cache(struct page *page, struct kmem_cache *cache) | |
585 | { | |
586 | page->lru.next = (struct list_head *)cache; | |
587 | } | |
588 | ||
589 | static inline struct kmem_cache *page_get_cache(struct page *page) | |
590 | { | |
591 | page = compound_head(page); | |
592 | BUG_ON(!PageSlab(page)); | |
593 | return (struct kmem_cache *)page->lru.next; | |
594 | } | |
595 | ||
596 | static inline void page_set_slab(struct page *page, struct slab *slab) | |
597 | { | |
598 | page->lru.prev = (struct list_head *)slab; | |
599 | } | |
600 | ||
601 | static inline struct slab *page_get_slab(struct page *page) | |
602 | { | |
603 | BUG_ON(!PageSlab(page)); | |
604 | return (struct slab *)page->lru.prev; | |
605 | } | |
606 | ||
607 | static inline struct kmem_cache *virt_to_cache(const void *obj) | |
608 | { | |
609 | struct page *page = virt_to_head_page(obj); | |
610 | return page_get_cache(page); | |
611 | } | |
612 | ||
613 | static inline struct slab *virt_to_slab(const void *obj) | |
614 | { | |
615 | struct page *page = virt_to_head_page(obj); | |
616 | return page_get_slab(page); | |
617 | } | |
618 | ||
619 | static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, | |
620 | unsigned int idx) | |
621 | { | |
622 | return slab->s_mem + cache->buffer_size * idx; | |
623 | } | |
624 | ||
625 | /* | |
626 | * We want to avoid an expensive divide : (offset / cache->buffer_size) | |
627 | * Using the fact that buffer_size is a constant for a particular cache, | |
628 | * we can replace (offset / cache->buffer_size) by | |
629 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) | |
630 | */ | |
631 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, | |
632 | const struct slab *slab, void *obj) | |
633 | { | |
634 | u32 offset = (obj - slab->s_mem); | |
635 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); | |
636 | } | |
637 | ||
638 | /* | |
639 | * These are the default caches for kmalloc. Custom caches can have other sizes. | |
640 | */ | |
641 | struct cache_sizes malloc_sizes[] = { | |
642 | #define CACHE(x) { .cs_size = (x) }, | |
643 | #include <linux/kmalloc_sizes.h> | |
644 | CACHE(ULONG_MAX) | |
645 | #undef CACHE | |
646 | }; | |
647 | EXPORT_SYMBOL(malloc_sizes); | |
648 | ||
649 | /* Must match cache_sizes above. Out of line to keep cache footprint low. */ | |
650 | struct cache_names { | |
651 | char *name; | |
652 | char *name_dma; | |
653 | }; | |
654 | ||
655 | static struct cache_names __initdata cache_names[] = { | |
656 | #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" }, | |
657 | #include <linux/kmalloc_sizes.h> | |
658 | {NULL,} | |
659 | #undef CACHE | |
660 | }; | |
661 | ||
662 | static struct arraycache_init initarray_cache __initdata = | |
663 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; | |
664 | static struct arraycache_init initarray_generic = | |
665 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; | |
666 | ||
667 | /* internal cache of cache description objs */ | |
668 | static struct kmem_cache cache_cache = { | |
669 | .batchcount = 1, | |
670 | .limit = BOOT_CPUCACHE_ENTRIES, | |
671 | .shared = 1, | |
672 | .buffer_size = sizeof(struct kmem_cache), | |
673 | .name = "kmem_cache", | |
674 | }; | |
675 | ||
676 | #define BAD_ALIEN_MAGIC 0x01020304ul | |
677 | ||
678 | #ifdef CONFIG_LOCKDEP | |
679 | ||
680 | /* | |
681 | * Slab sometimes uses the kmalloc slabs to store the slab headers | |
682 | * for other slabs "off slab". | |
683 | * The locking for this is tricky in that it nests within the locks | |
684 | * of all other slabs in a few places; to deal with this special | |
685 | * locking we put on-slab caches into a separate lock-class. | |
686 | * | |
687 | * We set lock class for alien array caches which are up during init. | |
688 | * The lock annotation will be lost if all cpus of a node goes down and | |
689 | * then comes back up during hotplug | |
690 | */ | |
691 | static struct lock_class_key on_slab_l3_key; | |
692 | static struct lock_class_key on_slab_alc_key; | |
693 | ||
694 | static inline void init_lock_keys(void) | |
695 | ||
696 | { | |
697 | int q; | |
698 | struct cache_sizes *s = malloc_sizes; | |
699 | ||
700 | while (s->cs_size != ULONG_MAX) { | |
701 | for_each_node(q) { | |
702 | struct array_cache **alc; | |
703 | int r; | |
704 | struct kmem_list3 *l3 = s->cs_cachep->nodelists[q]; | |
705 | if (!l3 || OFF_SLAB(s->cs_cachep)) | |
706 | continue; | |
707 | lockdep_set_class(&l3->list_lock, &on_slab_l3_key); | |
708 | alc = l3->alien; | |
709 | /* | |
710 | * FIXME: This check for BAD_ALIEN_MAGIC | |
711 | * should go away when common slab code is taught to | |
712 | * work even without alien caches. | |
713 | * Currently, non NUMA code returns BAD_ALIEN_MAGIC | |
714 | * for alloc_alien_cache, | |
715 | */ | |
716 | if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) | |
717 | continue; | |
718 | for_each_node(r) { | |
719 | if (alc[r]) | |
720 | lockdep_set_class(&alc[r]->lock, | |
721 | &on_slab_alc_key); | |
722 | } | |
723 | } | |
724 | s++; | |
725 | } | |
726 | } | |
727 | #else | |
728 | static inline void init_lock_keys(void) | |
729 | { | |
730 | } | |
731 | #endif | |
732 | ||
733 | /* | |
734 | * 1. Guard access to the cache-chain. | |
735 | * 2. Protect sanity of cpu_online_map against cpu hotplug events | |
736 | */ | |
737 | static DEFINE_MUTEX(cache_chain_mutex); | |
738 | static struct list_head cache_chain; | |
739 | ||
740 | /* | |
741 | * chicken and egg problem: delay the per-cpu array allocation | |
742 | * until the general caches are up. | |
743 | */ | |
744 | static enum { | |
745 | NONE, | |
746 | PARTIAL_AC, | |
747 | PARTIAL_L3, | |
748 | FULL | |
749 | } g_cpucache_up; | |
750 | ||
751 | /* | |
752 | * used by boot code to determine if it can use slab based allocator | |
753 | */ | |
754 | int slab_is_available(void) | |
755 | { | |
756 | return g_cpucache_up == FULL; | |
757 | } | |
758 | ||
759 | static DEFINE_PER_CPU(struct delayed_work, reap_work); | |
760 | ||
761 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) | |
762 | { | |
763 | return cachep->array[smp_processor_id()]; | |
764 | } | |
765 | ||
766 | static inline struct kmem_cache *__find_general_cachep(size_t size, | |
767 | gfp_t gfpflags) | |
768 | { | |
769 | struct cache_sizes *csizep = malloc_sizes; | |
770 | ||
771 | #if DEBUG | |
772 | /* This happens if someone tries to call | |
773 | * kmem_cache_create(), or __kmalloc(), before | |
774 | * the generic caches are initialized. | |
775 | */ | |
776 | BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); | |
777 | #endif | |
778 | if (!size) | |
779 | return ZERO_SIZE_PTR; | |
780 | ||
781 | while (size > csizep->cs_size) | |
782 | csizep++; | |
783 | ||
784 | /* | |
785 | * Really subtle: The last entry with cs->cs_size==ULONG_MAX | |
786 | * has cs_{dma,}cachep==NULL. Thus no special case | |
787 | * for large kmalloc calls required. | |
788 | */ | |
789 | #ifdef CONFIG_ZONE_DMA | |
790 | if (unlikely(gfpflags & GFP_DMA)) | |
791 | return csizep->cs_dmacachep; | |
792 | #endif | |
793 | return csizep->cs_cachep; | |
794 | } | |
795 | ||
796 | static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) | |
797 | { | |
798 | return __find_general_cachep(size, gfpflags); | |
799 | } | |
800 | ||
801 | static size_t slab_mgmt_size(size_t nr_objs, size_t align) | |
802 | { | |
803 | return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); | |
804 | } | |
805 | ||
806 | /* | |
807 | * Calculate the number of objects and left-over bytes for a given buffer size. | |
808 | */ | |
809 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, | |
810 | size_t align, int flags, size_t *left_over, | |
811 | unsigned int *num) | |
812 | { | |
813 | int nr_objs; | |
814 | size_t mgmt_size; | |
815 | size_t slab_size = PAGE_SIZE << gfporder; | |
816 | ||
817 | /* | |
818 | * The slab management structure can be either off the slab or | |
819 | * on it. For the latter case, the memory allocated for a | |
820 | * slab is used for: | |
821 | * | |
822 | * - The struct slab | |
823 | * - One kmem_bufctl_t for each object | |
824 | * - Padding to respect alignment of @align | |
825 | * - @buffer_size bytes for each object | |
826 | * | |
827 | * If the slab management structure is off the slab, then the | |
828 | * alignment will already be calculated into the size. Because | |
829 | * the slabs are all pages aligned, the objects will be at the | |
830 | * correct alignment when allocated. | |
831 | */ | |
832 | if (flags & CFLGS_OFF_SLAB) { | |
833 | mgmt_size = 0; | |
834 | nr_objs = slab_size / buffer_size; | |
835 | ||
836 | if (nr_objs > SLAB_LIMIT) | |
837 | nr_objs = SLAB_LIMIT; | |
838 | } else { | |
839 | /* | |
840 | * Ignore padding for the initial guess. The padding | |
841 | * is at most @align-1 bytes, and @buffer_size is at | |
842 | * least @align. In the worst case, this result will | |
843 | * be one greater than the number of objects that fit | |
844 | * into the memory allocation when taking the padding | |
845 | * into account. | |
846 | */ | |
847 | nr_objs = (slab_size - sizeof(struct slab)) / | |
848 | (buffer_size + sizeof(kmem_bufctl_t)); | |
849 | ||
850 | /* | |
851 | * This calculated number will be either the right | |
852 | * amount, or one greater than what we want. | |
853 | */ | |
854 | if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size | |
855 | > slab_size) | |
856 | nr_objs--; | |
857 | ||
858 | if (nr_objs > SLAB_LIMIT) | |
859 | nr_objs = SLAB_LIMIT; | |
860 | ||
861 | mgmt_size = slab_mgmt_size(nr_objs, align); | |
862 | } | |
863 | *num = nr_objs; | |
864 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; | |
865 | } | |
866 | ||
867 | #define slab_error(cachep, msg) __slab_error(__FUNCTION__, cachep, msg) | |
868 | ||
869 | static void __slab_error(const char *function, struct kmem_cache *cachep, | |
870 | char *msg) | |
871 | { | |
872 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", | |
873 | function, cachep->name, msg); | |
874 | dump_stack(); | |
875 | } | |
876 | ||
877 | /* | |
878 | * By default on NUMA we use alien caches to stage the freeing of | |
879 | * objects allocated from other nodes. This causes massive memory | |
880 | * inefficiencies when using fake NUMA setup to split memory into a | |
881 | * large number of small nodes, so it can be disabled on the command | |
882 | * line | |
883 | */ | |
884 | ||
885 | static int use_alien_caches __read_mostly = 1; | |
886 | static int __init noaliencache_setup(char *s) | |
887 | { | |
888 | use_alien_caches = 0; | |
889 | return 1; | |
890 | } | |
891 | __setup("noaliencache", noaliencache_setup); | |
892 | ||
893 | #ifdef CONFIG_NUMA | |
894 | /* | |
895 | * Special reaping functions for NUMA systems called from cache_reap(). | |
896 | * These take care of doing round robin flushing of alien caches (containing | |
897 | * objects freed on different nodes from which they were allocated) and the | |
898 | * flushing of remote pcps by calling drain_node_pages. | |
899 | */ | |
900 | static DEFINE_PER_CPU(unsigned long, reap_node); | |
901 | ||
902 | static void init_reap_node(int cpu) | |
903 | { | |
904 | int node; | |
905 | ||
906 | node = next_node(cpu_to_node(cpu), node_online_map); | |
907 | if (node == MAX_NUMNODES) | |
908 | node = first_node(node_online_map); | |
909 | ||
910 | per_cpu(reap_node, cpu) = node; | |
911 | } | |
912 | ||
913 | static void next_reap_node(void) | |
914 | { | |
915 | int node = __get_cpu_var(reap_node); | |
916 | ||
917 | node = next_node(node, node_online_map); | |
918 | if (unlikely(node >= MAX_NUMNODES)) | |
919 | node = first_node(node_online_map); | |
920 | __get_cpu_var(reap_node) = node; | |
921 | } | |
922 | ||
923 | #else | |
924 | #define init_reap_node(cpu) do { } while (0) | |
925 | #define next_reap_node(void) do { } while (0) | |
926 | #endif | |
927 | ||
928 | /* | |
929 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz | |
930 | * via the workqueue/eventd. | |
931 | * Add the CPU number into the expiration time to minimize the possibility of | |
932 | * the CPUs getting into lockstep and contending for the global cache chain | |
933 | * lock. | |
934 | */ | |
935 | static void __cpuinit start_cpu_timer(int cpu) | |
936 | { | |
937 | struct delayed_work *reap_work = &per_cpu(reap_work, cpu); | |
938 | ||
939 | /* | |
940 | * When this gets called from do_initcalls via cpucache_init(), | |
941 | * init_workqueues() has already run, so keventd will be setup | |
942 | * at that time. | |
943 | */ | |
944 | if (keventd_up() && reap_work->work.func == NULL) { | |
945 | init_reap_node(cpu); | |
946 | INIT_DELAYED_WORK(reap_work, cache_reap); | |
947 | schedule_delayed_work_on(cpu, reap_work, | |
948 | __round_jiffies_relative(HZ, cpu)); | |
949 | } | |
950 | } | |
951 | ||
952 | static struct array_cache *alloc_arraycache(int node, int entries, | |
953 | int batchcount) | |
954 | { | |
955 | int memsize = sizeof(void *) * entries + sizeof(struct array_cache); | |
956 | struct array_cache *nc = NULL; | |
957 | ||
958 | nc = kmalloc_node(memsize, GFP_KERNEL, node); | |
959 | if (nc) { | |
960 | nc->avail = 0; | |
961 | nc->limit = entries; | |
962 | nc->batchcount = batchcount; | |
963 | nc->touched = 0; | |
964 | spin_lock_init(&nc->lock); | |
965 | } | |
966 | return nc; | |
967 | } | |
968 | ||
969 | /* | |
970 | * Transfer objects in one arraycache to another. | |
971 | * Locking must be handled by the caller. | |
972 | * | |
973 | * Return the number of entries transferred. | |
974 | */ | |
975 | static int transfer_objects(struct array_cache *to, | |
976 | struct array_cache *from, unsigned int max) | |
977 | { | |
978 | /* Figure out how many entries to transfer */ | |
979 | int nr = min(min(from->avail, max), to->limit - to->avail); | |
980 | ||
981 | if (!nr) | |
982 | return 0; | |
983 | ||
984 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, | |
985 | sizeof(void *) *nr); | |
986 | ||
987 | from->avail -= nr; | |
988 | to->avail += nr; | |
989 | to->touched = 1; | |
990 | return nr; | |
991 | } | |
992 | ||
993 | #ifndef CONFIG_NUMA | |
994 | ||
995 | #define drain_alien_cache(cachep, alien) do { } while (0) | |
996 | #define reap_alien(cachep, l3) do { } while (0) | |
997 | ||
998 | static inline struct array_cache **alloc_alien_cache(int node, int limit) | |
999 | { | |
1000 | return (struct array_cache **)BAD_ALIEN_MAGIC; | |
1001 | } | |
1002 | ||
1003 | static inline void free_alien_cache(struct array_cache **ac_ptr) | |
1004 | { | |
1005 | } | |
1006 | ||
1007 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
1008 | { | |
1009 | return 0; | |
1010 | } | |
1011 | ||
1012 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, | |
1013 | gfp_t flags) | |
1014 | { | |
1015 | return NULL; | |
1016 | } | |
1017 | ||
1018 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, | |
1019 | gfp_t flags, int nodeid) | |
1020 | { | |
1021 | return NULL; | |
1022 | } | |
1023 | ||
1024 | #else /* CONFIG_NUMA */ | |
1025 | ||
1026 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); | |
1027 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); | |
1028 | ||
1029 | static struct array_cache **alloc_alien_cache(int node, int limit) | |
1030 | { | |
1031 | struct array_cache **ac_ptr; | |
1032 | int memsize = sizeof(void *) * nr_node_ids; | |
1033 | int i; | |
1034 | ||
1035 | if (limit > 1) | |
1036 | limit = 12; | |
1037 | ac_ptr = kmalloc_node(memsize, GFP_KERNEL, node); | |
1038 | if (ac_ptr) { | |
1039 | for_each_node(i) { | |
1040 | if (i == node || !node_online(i)) { | |
1041 | ac_ptr[i] = NULL; | |
1042 | continue; | |
1043 | } | |
1044 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d); | |
1045 | if (!ac_ptr[i]) { | |
1046 | for (i--; i <= 0; i--) | |
1047 | kfree(ac_ptr[i]); | |
1048 | kfree(ac_ptr); | |
1049 | return NULL; | |
1050 | } | |
1051 | } | |
1052 | } | |
1053 | return ac_ptr; | |
1054 | } | |
1055 | ||
1056 | static void free_alien_cache(struct array_cache **ac_ptr) | |
1057 | { | |
1058 | int i; | |
1059 | ||
1060 | if (!ac_ptr) | |
1061 | return; | |
1062 | for_each_node(i) | |
1063 | kfree(ac_ptr[i]); | |
1064 | kfree(ac_ptr); | |
1065 | } | |
1066 | ||
1067 | static void __drain_alien_cache(struct kmem_cache *cachep, | |
1068 | struct array_cache *ac, int node) | |
1069 | { | |
1070 | struct kmem_list3 *rl3 = cachep->nodelists[node]; | |
1071 | ||
1072 | if (ac->avail) { | |
1073 | spin_lock(&rl3->list_lock); | |
1074 | /* | |
1075 | * Stuff objects into the remote nodes shared array first. | |
1076 | * That way we could avoid the overhead of putting the objects | |
1077 | * into the free lists and getting them back later. | |
1078 | */ | |
1079 | if (rl3->shared) | |
1080 | transfer_objects(rl3->shared, ac, ac->limit); | |
1081 | ||
1082 | free_block(cachep, ac->entry, ac->avail, node); | |
1083 | ac->avail = 0; | |
1084 | spin_unlock(&rl3->list_lock); | |
1085 | } | |
1086 | } | |
1087 | ||
1088 | /* | |
1089 | * Called from cache_reap() to regularly drain alien caches round robin. | |
1090 | */ | |
1091 | static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) | |
1092 | { | |
1093 | int node = __get_cpu_var(reap_node); | |
1094 | ||
1095 | if (l3->alien) { | |
1096 | struct array_cache *ac = l3->alien[node]; | |
1097 | ||
1098 | if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { | |
1099 | __drain_alien_cache(cachep, ac, node); | |
1100 | spin_unlock_irq(&ac->lock); | |
1101 | } | |
1102 | } | |
1103 | } | |
1104 | ||
1105 | static void drain_alien_cache(struct kmem_cache *cachep, | |
1106 | struct array_cache **alien) | |
1107 | { | |
1108 | int i = 0; | |
1109 | struct array_cache *ac; | |
1110 | unsigned long flags; | |
1111 | ||
1112 | for_each_online_node(i) { | |
1113 | ac = alien[i]; | |
1114 | if (ac) { | |
1115 | spin_lock_irqsave(&ac->lock, flags); | |
1116 | __drain_alien_cache(cachep, ac, i); | |
1117 | spin_unlock_irqrestore(&ac->lock, flags); | |
1118 | } | |
1119 | } | |
1120 | } | |
1121 | ||
1122 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
1123 | { | |
1124 | struct slab *slabp = virt_to_slab(objp); | |
1125 | int nodeid = slabp->nodeid; | |
1126 | struct kmem_list3 *l3; | |
1127 | struct array_cache *alien = NULL; | |
1128 | int node; | |
1129 | ||
1130 | node = numa_node_id(); | |
1131 | ||
1132 | /* | |
1133 | * Make sure we are not freeing a object from another node to the array | |
1134 | * cache on this cpu. | |
1135 | */ | |
1136 | if (likely(slabp->nodeid == node)) | |
1137 | return 0; | |
1138 | ||
1139 | l3 = cachep->nodelists[node]; | |
1140 | STATS_INC_NODEFREES(cachep); | |
1141 | if (l3->alien && l3->alien[nodeid]) { | |
1142 | alien = l3->alien[nodeid]; | |
1143 | spin_lock(&alien->lock); | |
1144 | if (unlikely(alien->avail == alien->limit)) { | |
1145 | STATS_INC_ACOVERFLOW(cachep); | |
1146 | __drain_alien_cache(cachep, alien, nodeid); | |
1147 | } | |
1148 | alien->entry[alien->avail++] = objp; | |
1149 | spin_unlock(&alien->lock); | |
1150 | } else { | |
1151 | spin_lock(&(cachep->nodelists[nodeid])->list_lock); | |
1152 | free_block(cachep, &objp, 1, nodeid); | |
1153 | spin_unlock(&(cachep->nodelists[nodeid])->list_lock); | |
1154 | } | |
1155 | return 1; | |
1156 | } | |
1157 | #endif | |
1158 | ||
1159 | static int __cpuinit cpuup_callback(struct notifier_block *nfb, | |
1160 | unsigned long action, void *hcpu) | |
1161 | { | |
1162 | long cpu = (long)hcpu; | |
1163 | struct kmem_cache *cachep; | |
1164 | struct kmem_list3 *l3 = NULL; | |
1165 | int node = cpu_to_node(cpu); | |
1166 | const int memsize = sizeof(struct kmem_list3); | |
1167 | ||
1168 | switch (action) { | |
1169 | case CPU_LOCK_ACQUIRE: | |
1170 | mutex_lock(&cache_chain_mutex); | |
1171 | break; | |
1172 | case CPU_UP_PREPARE: | |
1173 | case CPU_UP_PREPARE_FROZEN: | |
1174 | /* | |
1175 | * We need to do this right in the beginning since | |
1176 | * alloc_arraycache's are going to use this list. | |
1177 | * kmalloc_node allows us to add the slab to the right | |
1178 | * kmem_list3 and not this cpu's kmem_list3 | |
1179 | */ | |
1180 | ||
1181 | list_for_each_entry(cachep, &cache_chain, next) { | |
1182 | /* | |
1183 | * Set up the size64 kmemlist for cpu before we can | |
1184 | * begin anything. Make sure some other cpu on this | |
1185 | * node has not already allocated this | |
1186 | */ | |
1187 | if (!cachep->nodelists[node]) { | |
1188 | l3 = kmalloc_node(memsize, GFP_KERNEL, node); | |
1189 | if (!l3) | |
1190 | goto bad; | |
1191 | kmem_list3_init(l3); | |
1192 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + | |
1193 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
1194 | ||
1195 | /* | |
1196 | * The l3s don't come and go as CPUs come and | |
1197 | * go. cache_chain_mutex is sufficient | |
1198 | * protection here. | |
1199 | */ | |
1200 | cachep->nodelists[node] = l3; | |
1201 | } | |
1202 | ||
1203 | spin_lock_irq(&cachep->nodelists[node]->list_lock); | |
1204 | cachep->nodelists[node]->free_limit = | |
1205 | (1 + nr_cpus_node(node)) * | |
1206 | cachep->batchcount + cachep->num; | |
1207 | spin_unlock_irq(&cachep->nodelists[node]->list_lock); | |
1208 | } | |
1209 | ||
1210 | /* | |
1211 | * Now we can go ahead with allocating the shared arrays and | |
1212 | * array caches | |
1213 | */ | |
1214 | list_for_each_entry(cachep, &cache_chain, next) { | |
1215 | struct array_cache *nc; | |
1216 | struct array_cache *shared = NULL; | |
1217 | struct array_cache **alien = NULL; | |
1218 | ||
1219 | nc = alloc_arraycache(node, cachep->limit, | |
1220 | cachep->batchcount); | |
1221 | if (!nc) | |
1222 | goto bad; | |
1223 | if (cachep->shared) { | |
1224 | shared = alloc_arraycache(node, | |
1225 | cachep->shared * cachep->batchcount, | |
1226 | 0xbaadf00d); | |
1227 | if (!shared) | |
1228 | goto bad; | |
1229 | } | |
1230 | if (use_alien_caches) { | |
1231 | alien = alloc_alien_cache(node, cachep->limit); | |
1232 | if (!alien) | |
1233 | goto bad; | |
1234 | } | |
1235 | cachep->array[cpu] = nc; | |
1236 | l3 = cachep->nodelists[node]; | |
1237 | BUG_ON(!l3); | |
1238 | ||
1239 | spin_lock_irq(&l3->list_lock); | |
1240 | if (!l3->shared) { | |
1241 | /* | |
1242 | * We are serialised from CPU_DEAD or | |
1243 | * CPU_UP_CANCELLED by the cpucontrol lock | |
1244 | */ | |
1245 | l3->shared = shared; | |
1246 | shared = NULL; | |
1247 | } | |
1248 | #ifdef CONFIG_NUMA | |
1249 | if (!l3->alien) { | |
1250 | l3->alien = alien; | |
1251 | alien = NULL; | |
1252 | } | |
1253 | #endif | |
1254 | spin_unlock_irq(&l3->list_lock); | |
1255 | kfree(shared); | |
1256 | free_alien_cache(alien); | |
1257 | } | |
1258 | break; | |
1259 | case CPU_ONLINE: | |
1260 | case CPU_ONLINE_FROZEN: | |
1261 | start_cpu_timer(cpu); | |
1262 | break; | |
1263 | #ifdef CONFIG_HOTPLUG_CPU | |
1264 | case CPU_DOWN_PREPARE: | |
1265 | case CPU_DOWN_PREPARE_FROZEN: | |
1266 | /* | |
1267 | * Shutdown cache reaper. Note that the cache_chain_mutex is | |
1268 | * held so that if cache_reap() is invoked it cannot do | |
1269 | * anything expensive but will only modify reap_work | |
1270 | * and reschedule the timer. | |
1271 | */ | |
1272 | cancel_rearming_delayed_work(&per_cpu(reap_work, cpu)); | |
1273 | /* Now the cache_reaper is guaranteed to be not running. */ | |
1274 | per_cpu(reap_work, cpu).work.func = NULL; | |
1275 | break; | |
1276 | case CPU_DOWN_FAILED: | |
1277 | case CPU_DOWN_FAILED_FROZEN: | |
1278 | start_cpu_timer(cpu); | |
1279 | break; | |
1280 | case CPU_DEAD: | |
1281 | case CPU_DEAD_FROZEN: | |
1282 | /* | |
1283 | * Even if all the cpus of a node are down, we don't free the | |
1284 | * kmem_list3 of any cache. This to avoid a race between | |
1285 | * cpu_down, and a kmalloc allocation from another cpu for | |
1286 | * memory from the node of the cpu going down. The list3 | |
1287 | * structure is usually allocated from kmem_cache_create() and | |
1288 | * gets destroyed at kmem_cache_destroy(). | |
1289 | */ | |
1290 | /* fall thru */ | |
1291 | #endif | |
1292 | case CPU_UP_CANCELED: | |
1293 | case CPU_UP_CANCELED_FROZEN: | |
1294 | list_for_each_entry(cachep, &cache_chain, next) { | |
1295 | struct array_cache *nc; | |
1296 | struct array_cache *shared; | |
1297 | struct array_cache **alien; | |
1298 | cpumask_t mask; | |
1299 | ||
1300 | mask = node_to_cpumask(node); | |
1301 | /* cpu is dead; no one can alloc from it. */ | |
1302 | nc = cachep->array[cpu]; | |
1303 | cachep->array[cpu] = NULL; | |
1304 | l3 = cachep->nodelists[node]; | |
1305 | ||
1306 | if (!l3) | |
1307 | goto free_array_cache; | |
1308 | ||
1309 | spin_lock_irq(&l3->list_lock); | |
1310 | ||
1311 | /* Free limit for this kmem_list3 */ | |
1312 | l3->free_limit -= cachep->batchcount; | |
1313 | if (nc) | |
1314 | free_block(cachep, nc->entry, nc->avail, node); | |
1315 | ||
1316 | if (!cpus_empty(mask)) { | |
1317 | spin_unlock_irq(&l3->list_lock); | |
1318 | goto free_array_cache; | |
1319 | } | |
1320 | ||
1321 | shared = l3->shared; | |
1322 | if (shared) { | |
1323 | free_block(cachep, shared->entry, | |
1324 | shared->avail, node); | |
1325 | l3->shared = NULL; | |
1326 | } | |
1327 | ||
1328 | alien = l3->alien; | |
1329 | l3->alien = NULL; | |
1330 | ||
1331 | spin_unlock_irq(&l3->list_lock); | |
1332 | ||
1333 | kfree(shared); | |
1334 | if (alien) { | |
1335 | drain_alien_cache(cachep, alien); | |
1336 | free_alien_cache(alien); | |
1337 | } | |
1338 | free_array_cache: | |
1339 | kfree(nc); | |
1340 | } | |
1341 | /* | |
1342 | * In the previous loop, all the objects were freed to | |
1343 | * the respective cache's slabs, now we can go ahead and | |
1344 | * shrink each nodelist to its limit. | |
1345 | */ | |
1346 | list_for_each_entry(cachep, &cache_chain, next) { | |
1347 | l3 = cachep->nodelists[node]; | |
1348 | if (!l3) | |
1349 | continue; | |
1350 | drain_freelist(cachep, l3, l3->free_objects); | |
1351 | } | |
1352 | break; | |
1353 | case CPU_LOCK_RELEASE: | |
1354 | mutex_unlock(&cache_chain_mutex); | |
1355 | break; | |
1356 | } | |
1357 | return NOTIFY_OK; | |
1358 | bad: | |
1359 | return NOTIFY_BAD; | |
1360 | } | |
1361 | ||
1362 | static struct notifier_block __cpuinitdata cpucache_notifier = { | |
1363 | &cpuup_callback, NULL, 0 | |
1364 | }; | |
1365 | ||
1366 | /* | |
1367 | * swap the static kmem_list3 with kmalloced memory | |
1368 | */ | |
1369 | static void init_list(struct kmem_cache *cachep, struct kmem_list3 *list, | |
1370 | int nodeid) | |
1371 | { | |
1372 | struct kmem_list3 *ptr; | |
1373 | ||
1374 | ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, nodeid); | |
1375 | BUG_ON(!ptr); | |
1376 | ||
1377 | local_irq_disable(); | |
1378 | memcpy(ptr, list, sizeof(struct kmem_list3)); | |
1379 | /* | |
1380 | * Do not assume that spinlocks can be initialized via memcpy: | |
1381 | */ | |
1382 | spin_lock_init(&ptr->list_lock); | |
1383 | ||
1384 | MAKE_ALL_LISTS(cachep, ptr, nodeid); | |
1385 | cachep->nodelists[nodeid] = ptr; | |
1386 | local_irq_enable(); | |
1387 | } | |
1388 | ||
1389 | /* | |
1390 | * Initialisation. Called after the page allocator have been initialised and | |
1391 | * before smp_init(). | |
1392 | */ | |
1393 | void __init kmem_cache_init(void) | |
1394 | { | |
1395 | size_t left_over; | |
1396 | struct cache_sizes *sizes; | |
1397 | struct cache_names *names; | |
1398 | int i; | |
1399 | int order; | |
1400 | int node; | |
1401 | ||
1402 | if (num_possible_nodes() == 1) | |
1403 | use_alien_caches = 0; | |
1404 | ||
1405 | for (i = 0; i < NUM_INIT_LISTS; i++) { | |
1406 | kmem_list3_init(&initkmem_list3[i]); | |
1407 | if (i < MAX_NUMNODES) | |
1408 | cache_cache.nodelists[i] = NULL; | |
1409 | } | |
1410 | ||
1411 | /* | |
1412 | * Fragmentation resistance on low memory - only use bigger | |
1413 | * page orders on machines with more than 32MB of memory. | |
1414 | */ | |
1415 | if (num_physpages > (32 << 20) >> PAGE_SHIFT) | |
1416 | slab_break_gfp_order = BREAK_GFP_ORDER_HI; | |
1417 | ||
1418 | /* Bootstrap is tricky, because several objects are allocated | |
1419 | * from caches that do not exist yet: | |
1420 | * 1) initialize the cache_cache cache: it contains the struct | |
1421 | * kmem_cache structures of all caches, except cache_cache itself: | |
1422 | * cache_cache is statically allocated. | |
1423 | * Initially an __init data area is used for the head array and the | |
1424 | * kmem_list3 structures, it's replaced with a kmalloc allocated | |
1425 | * array at the end of the bootstrap. | |
1426 | * 2) Create the first kmalloc cache. | |
1427 | * The struct kmem_cache for the new cache is allocated normally. | |
1428 | * An __init data area is used for the head array. | |
1429 | * 3) Create the remaining kmalloc caches, with minimally sized | |
1430 | * head arrays. | |
1431 | * 4) Replace the __init data head arrays for cache_cache and the first | |
1432 | * kmalloc cache with kmalloc allocated arrays. | |
1433 | * 5) Replace the __init data for kmem_list3 for cache_cache and | |
1434 | * the other cache's with kmalloc allocated memory. | |
1435 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. | |
1436 | */ | |
1437 | ||
1438 | node = numa_node_id(); | |
1439 | ||
1440 | /* 1) create the cache_cache */ | |
1441 | INIT_LIST_HEAD(&cache_chain); | |
1442 | list_add(&cache_cache.next, &cache_chain); | |
1443 | cache_cache.colour_off = cache_line_size(); | |
1444 | cache_cache.array[smp_processor_id()] = &initarray_cache.cache; | |
1445 | cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE]; | |
1446 | ||
1447 | /* | |
1448 | * struct kmem_cache size depends on nr_node_ids, which | |
1449 | * can be less than MAX_NUMNODES. | |
1450 | */ | |
1451 | cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) + | |
1452 | nr_node_ids * sizeof(struct kmem_list3 *); | |
1453 | #if DEBUG | |
1454 | cache_cache.obj_size = cache_cache.buffer_size; | |
1455 | #endif | |
1456 | cache_cache.buffer_size = ALIGN(cache_cache.buffer_size, | |
1457 | cache_line_size()); | |
1458 | cache_cache.reciprocal_buffer_size = | |
1459 | reciprocal_value(cache_cache.buffer_size); | |
1460 | ||
1461 | for (order = 0; order < MAX_ORDER; order++) { | |
1462 | cache_estimate(order, cache_cache.buffer_size, | |
1463 | cache_line_size(), 0, &left_over, &cache_cache.num); | |
1464 | if (cache_cache.num) | |
1465 | break; | |
1466 | } | |
1467 | BUG_ON(!cache_cache.num); | |
1468 | cache_cache.gfporder = order; | |
1469 | cache_cache.colour = left_over / cache_cache.colour_off; | |
1470 | cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) + | |
1471 | sizeof(struct slab), cache_line_size()); | |
1472 | ||
1473 | /* 2+3) create the kmalloc caches */ | |
1474 | sizes = malloc_sizes; | |
1475 | names = cache_names; | |
1476 | ||
1477 | /* | |
1478 | * Initialize the caches that provide memory for the array cache and the | |
1479 | * kmem_list3 structures first. Without this, further allocations will | |
1480 | * bug. | |
1481 | */ | |
1482 | ||
1483 | sizes[INDEX_AC].cs_cachep = kmem_cache_create(names[INDEX_AC].name, | |
1484 | sizes[INDEX_AC].cs_size, | |
1485 | ARCH_KMALLOC_MINALIGN, | |
1486 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, | |
1487 | NULL, NULL); | |
1488 | ||
1489 | if (INDEX_AC != INDEX_L3) { | |
1490 | sizes[INDEX_L3].cs_cachep = | |
1491 | kmem_cache_create(names[INDEX_L3].name, | |
1492 | sizes[INDEX_L3].cs_size, | |
1493 | ARCH_KMALLOC_MINALIGN, | |
1494 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, | |
1495 | NULL, NULL); | |
1496 | } | |
1497 | ||
1498 | slab_early_init = 0; | |
1499 | ||
1500 | while (sizes->cs_size != ULONG_MAX) { | |
1501 | /* | |
1502 | * For performance, all the general caches are L1 aligned. | |
1503 | * This should be particularly beneficial on SMP boxes, as it | |
1504 | * eliminates "false sharing". | |
1505 | * Note for systems short on memory removing the alignment will | |
1506 | * allow tighter packing of the smaller caches. | |
1507 | */ | |
1508 | if (!sizes->cs_cachep) { | |
1509 | sizes->cs_cachep = kmem_cache_create(names->name, | |
1510 | sizes->cs_size, | |
1511 | ARCH_KMALLOC_MINALIGN, | |
1512 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, | |
1513 | NULL, NULL); | |
1514 | } | |
1515 | #ifdef CONFIG_ZONE_DMA | |
1516 | sizes->cs_dmacachep = kmem_cache_create( | |
1517 | names->name_dma, | |
1518 | sizes->cs_size, | |
1519 | ARCH_KMALLOC_MINALIGN, | |
1520 | ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA| | |
1521 | SLAB_PANIC, | |
1522 | NULL, NULL); | |
1523 | #endif | |
1524 | sizes++; | |
1525 | names++; | |
1526 | } | |
1527 | /* 4) Replace the bootstrap head arrays */ | |
1528 | { | |
1529 | struct array_cache *ptr; | |
1530 | ||
1531 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); | |
1532 | ||
1533 | local_irq_disable(); | |
1534 | BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); | |
1535 | memcpy(ptr, cpu_cache_get(&cache_cache), | |
1536 | sizeof(struct arraycache_init)); | |
1537 | /* | |
1538 | * Do not assume that spinlocks can be initialized via memcpy: | |
1539 | */ | |
1540 | spin_lock_init(&ptr->lock); | |
1541 | ||
1542 | cache_cache.array[smp_processor_id()] = ptr; | |
1543 | local_irq_enable(); | |
1544 | ||
1545 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); | |
1546 | ||
1547 | local_irq_disable(); | |
1548 | BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep) | |
1549 | != &initarray_generic.cache); | |
1550 | memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), | |
1551 | sizeof(struct arraycache_init)); | |
1552 | /* | |
1553 | * Do not assume that spinlocks can be initialized via memcpy: | |
1554 | */ | |
1555 | spin_lock_init(&ptr->lock); | |
1556 | ||
1557 | malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = | |
1558 | ptr; | |
1559 | local_irq_enable(); | |
1560 | } | |
1561 | /* 5) Replace the bootstrap kmem_list3's */ | |
1562 | { | |
1563 | int nid; | |
1564 | ||
1565 | /* Replace the static kmem_list3 structures for the boot cpu */ | |
1566 | init_list(&cache_cache, &initkmem_list3[CACHE_CACHE], node); | |
1567 | ||
1568 | for_each_online_node(nid) { | |
1569 | init_list(malloc_sizes[INDEX_AC].cs_cachep, | |
1570 | &initkmem_list3[SIZE_AC + nid], nid); | |
1571 | ||
1572 | if (INDEX_AC != INDEX_L3) { | |
1573 | init_list(malloc_sizes[INDEX_L3].cs_cachep, | |
1574 | &initkmem_list3[SIZE_L3 + nid], nid); | |
1575 | } | |
1576 | } | |
1577 | } | |
1578 | ||
1579 | /* 6) resize the head arrays to their final sizes */ | |
1580 | { | |
1581 | struct kmem_cache *cachep; | |
1582 | mutex_lock(&cache_chain_mutex); | |
1583 | list_for_each_entry(cachep, &cache_chain, next) | |
1584 | if (enable_cpucache(cachep)) | |
1585 | BUG(); | |
1586 | mutex_unlock(&cache_chain_mutex); | |
1587 | } | |
1588 | ||
1589 | /* Annotate slab for lockdep -- annotate the malloc caches */ | |
1590 | init_lock_keys(); | |
1591 | ||
1592 | ||
1593 | /* Done! */ | |
1594 | g_cpucache_up = FULL; | |
1595 | ||
1596 | /* | |
1597 | * Register a cpu startup notifier callback that initializes | |
1598 | * cpu_cache_get for all new cpus | |
1599 | */ | |
1600 | register_cpu_notifier(&cpucache_notifier); | |
1601 | ||
1602 | /* | |
1603 | * The reap timers are started later, with a module init call: That part | |
1604 | * of the kernel is not yet operational. | |
1605 | */ | |
1606 | } | |
1607 | ||
1608 | static int __init cpucache_init(void) | |
1609 | { | |
1610 | int cpu; | |
1611 | ||
1612 | /* | |
1613 | * Register the timers that return unneeded pages to the page allocator | |
1614 | */ | |
1615 | for_each_online_cpu(cpu) | |
1616 | start_cpu_timer(cpu); | |
1617 | return 0; | |
1618 | } | |
1619 | __initcall(cpucache_init); | |
1620 | ||
1621 | /* | |
1622 | * Interface to system's page allocator. No need to hold the cache-lock. | |
1623 | * | |
1624 | * If we requested dmaable memory, we will get it. Even if we | |
1625 | * did not request dmaable memory, we might get it, but that | |
1626 | * would be relatively rare and ignorable. | |
1627 | */ | |
1628 | static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) | |
1629 | { | |
1630 | struct page *page; | |
1631 | int nr_pages; | |
1632 | int i; | |
1633 | ||
1634 | #ifndef CONFIG_MMU | |
1635 | /* | |
1636 | * Nommu uses slab's for process anonymous memory allocations, and thus | |
1637 | * requires __GFP_COMP to properly refcount higher order allocations | |
1638 | */ | |
1639 | flags |= __GFP_COMP; | |
1640 | #endif | |
1641 | ||
1642 | flags |= cachep->gfpflags; | |
1643 | ||
1644 | page = alloc_pages_node(nodeid, flags, cachep->gfporder); | |
1645 | if (!page) | |
1646 | return NULL; | |
1647 | ||
1648 | nr_pages = (1 << cachep->gfporder); | |
1649 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1650 | add_zone_page_state(page_zone(page), | |
1651 | NR_SLAB_RECLAIMABLE, nr_pages); | |
1652 | else | |
1653 | add_zone_page_state(page_zone(page), | |
1654 | NR_SLAB_UNRECLAIMABLE, nr_pages); | |
1655 | for (i = 0; i < nr_pages; i++) | |
1656 | __SetPageSlab(page + i); | |
1657 | return page_address(page); | |
1658 | } | |
1659 | ||
1660 | /* | |
1661 | * Interface to system's page release. | |
1662 | */ | |
1663 | static void kmem_freepages(struct kmem_cache *cachep, void *addr) | |
1664 | { | |
1665 | unsigned long i = (1 << cachep->gfporder); | |
1666 | struct page *page = virt_to_page(addr); | |
1667 | const unsigned long nr_freed = i; | |
1668 | ||
1669 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1670 | sub_zone_page_state(page_zone(page), | |
1671 | NR_SLAB_RECLAIMABLE, nr_freed); | |
1672 | else | |
1673 | sub_zone_page_state(page_zone(page), | |
1674 | NR_SLAB_UNRECLAIMABLE, nr_freed); | |
1675 | while (i--) { | |
1676 | BUG_ON(!PageSlab(page)); | |
1677 | __ClearPageSlab(page); | |
1678 | page++; | |
1679 | } | |
1680 | if (current->reclaim_state) | |
1681 | current->reclaim_state->reclaimed_slab += nr_freed; | |
1682 | free_pages((unsigned long)addr, cachep->gfporder); | |
1683 | } | |
1684 | ||
1685 | static void kmem_rcu_free(struct rcu_head *head) | |
1686 | { | |
1687 | struct slab_rcu *slab_rcu = (struct slab_rcu *)head; | |
1688 | struct kmem_cache *cachep = slab_rcu->cachep; | |
1689 | ||
1690 | kmem_freepages(cachep, slab_rcu->addr); | |
1691 | if (OFF_SLAB(cachep)) | |
1692 | kmem_cache_free(cachep->slabp_cache, slab_rcu); | |
1693 | } | |
1694 | ||
1695 | #if DEBUG | |
1696 | ||
1697 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1698 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, | |
1699 | unsigned long caller) | |
1700 | { | |
1701 | int size = obj_size(cachep); | |
1702 | ||
1703 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; | |
1704 | ||
1705 | if (size < 5 * sizeof(unsigned long)) | |
1706 | return; | |
1707 | ||
1708 | *addr++ = 0x12345678; | |
1709 | *addr++ = caller; | |
1710 | *addr++ = smp_processor_id(); | |
1711 | size -= 3 * sizeof(unsigned long); | |
1712 | { | |
1713 | unsigned long *sptr = &caller; | |
1714 | unsigned long svalue; | |
1715 | ||
1716 | while (!kstack_end(sptr)) { | |
1717 | svalue = *sptr++; | |
1718 | if (kernel_text_address(svalue)) { | |
1719 | *addr++ = svalue; | |
1720 | size -= sizeof(unsigned long); | |
1721 | if (size <= sizeof(unsigned long)) | |
1722 | break; | |
1723 | } | |
1724 | } | |
1725 | ||
1726 | } | |
1727 | *addr++ = 0x87654321; | |
1728 | } | |
1729 | #endif | |
1730 | ||
1731 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) | |
1732 | { | |
1733 | int size = obj_size(cachep); | |
1734 | addr = &((char *)addr)[obj_offset(cachep)]; | |
1735 | ||
1736 | memset(addr, val, size); | |
1737 | *(unsigned char *)(addr + size - 1) = POISON_END; | |
1738 | } | |
1739 | ||
1740 | static void dump_line(char *data, int offset, int limit) | |
1741 | { | |
1742 | int i; | |
1743 | unsigned char error = 0; | |
1744 | int bad_count = 0; | |
1745 | ||
1746 | printk(KERN_ERR "%03x:", offset); | |
1747 | for (i = 0; i < limit; i++) { | |
1748 | if (data[offset + i] != POISON_FREE) { | |
1749 | error = data[offset + i]; | |
1750 | bad_count++; | |
1751 | } | |
1752 | printk(" %02x", (unsigned char)data[offset + i]); | |
1753 | } | |
1754 | printk("\n"); | |
1755 | ||
1756 | if (bad_count == 1) { | |
1757 | error ^= POISON_FREE; | |
1758 | if (!(error & (error - 1))) { | |
1759 | printk(KERN_ERR "Single bit error detected. Probably " | |
1760 | "bad RAM.\n"); | |
1761 | #ifdef CONFIG_X86 | |
1762 | printk(KERN_ERR "Run memtest86+ or a similar memory " | |
1763 | "test tool.\n"); | |
1764 | #else | |
1765 | printk(KERN_ERR "Run a memory test tool.\n"); | |
1766 | #endif | |
1767 | } | |
1768 | } | |
1769 | } | |
1770 | #endif | |
1771 | ||
1772 | #if DEBUG | |
1773 | ||
1774 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) | |
1775 | { | |
1776 | int i, size; | |
1777 | char *realobj; | |
1778 | ||
1779 | if (cachep->flags & SLAB_RED_ZONE) { | |
1780 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", | |
1781 | *dbg_redzone1(cachep, objp), | |
1782 | *dbg_redzone2(cachep, objp)); | |
1783 | } | |
1784 | ||
1785 | if (cachep->flags & SLAB_STORE_USER) { | |
1786 | printk(KERN_ERR "Last user: [<%p>]", | |
1787 | *dbg_userword(cachep, objp)); | |
1788 | print_symbol("(%s)", | |
1789 | (unsigned long)*dbg_userword(cachep, objp)); | |
1790 | printk("\n"); | |
1791 | } | |
1792 | realobj = (char *)objp + obj_offset(cachep); | |
1793 | size = obj_size(cachep); | |
1794 | for (i = 0; i < size && lines; i += 16, lines--) { | |
1795 | int limit; | |
1796 | limit = 16; | |
1797 | if (i + limit > size) | |
1798 | limit = size - i; | |
1799 | dump_line(realobj, i, limit); | |
1800 | } | |
1801 | } | |
1802 | ||
1803 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) | |
1804 | { | |
1805 | char *realobj; | |
1806 | int size, i; | |
1807 | int lines = 0; | |
1808 | ||
1809 | realobj = (char *)objp + obj_offset(cachep); | |
1810 | size = obj_size(cachep); | |
1811 | ||
1812 | for (i = 0; i < size; i++) { | |
1813 | char exp = POISON_FREE; | |
1814 | if (i == size - 1) | |
1815 | exp = POISON_END; | |
1816 | if (realobj[i] != exp) { | |
1817 | int limit; | |
1818 | /* Mismatch ! */ | |
1819 | /* Print header */ | |
1820 | if (lines == 0) { | |
1821 | printk(KERN_ERR | |
1822 | "Slab corruption: %s start=%p, len=%d\n", | |
1823 | cachep->name, realobj, size); | |
1824 | print_objinfo(cachep, objp, 0); | |
1825 | } | |
1826 | /* Hexdump the affected line */ | |
1827 | i = (i / 16) * 16; | |
1828 | limit = 16; | |
1829 | if (i + limit > size) | |
1830 | limit = size - i; | |
1831 | dump_line(realobj, i, limit); | |
1832 | i += 16; | |
1833 | lines++; | |
1834 | /* Limit to 5 lines */ | |
1835 | if (lines > 5) | |
1836 | break; | |
1837 | } | |
1838 | } | |
1839 | if (lines != 0) { | |
1840 | /* Print some data about the neighboring objects, if they | |
1841 | * exist: | |
1842 | */ | |
1843 | struct slab *slabp = virt_to_slab(objp); | |
1844 | unsigned int objnr; | |
1845 | ||
1846 | objnr = obj_to_index(cachep, slabp, objp); | |
1847 | if (objnr) { | |
1848 | objp = index_to_obj(cachep, slabp, objnr - 1); | |
1849 | realobj = (char *)objp + obj_offset(cachep); | |
1850 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", | |
1851 | realobj, size); | |
1852 | print_objinfo(cachep, objp, 2); | |
1853 | } | |
1854 | if (objnr + 1 < cachep->num) { | |
1855 | objp = index_to_obj(cachep, slabp, objnr + 1); | |
1856 | realobj = (char *)objp + obj_offset(cachep); | |
1857 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", | |
1858 | realobj, size); | |
1859 | print_objinfo(cachep, objp, 2); | |
1860 | } | |
1861 | } | |
1862 | } | |
1863 | #endif | |
1864 | ||
1865 | #if DEBUG | |
1866 | /** | |
1867 | * slab_destroy_objs - destroy a slab and its objects | |
1868 | * @cachep: cache pointer being destroyed | |
1869 | * @slabp: slab pointer being destroyed | |
1870 | * | |
1871 | * Call the registered destructor for each object in a slab that is being | |
1872 | * destroyed. | |
1873 | */ | |
1874 | static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp) | |
1875 | { | |
1876 | int i; | |
1877 | for (i = 0; i < cachep->num; i++) { | |
1878 | void *objp = index_to_obj(cachep, slabp, i); | |
1879 | ||
1880 | if (cachep->flags & SLAB_POISON) { | |
1881 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1882 | if (cachep->buffer_size % PAGE_SIZE == 0 && | |
1883 | OFF_SLAB(cachep)) | |
1884 | kernel_map_pages(virt_to_page(objp), | |
1885 | cachep->buffer_size / PAGE_SIZE, 1); | |
1886 | else | |
1887 | check_poison_obj(cachep, objp); | |
1888 | #else | |
1889 | check_poison_obj(cachep, objp); | |
1890 | #endif | |
1891 | } | |
1892 | if (cachep->flags & SLAB_RED_ZONE) { | |
1893 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
1894 | slab_error(cachep, "start of a freed object " | |
1895 | "was overwritten"); | |
1896 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
1897 | slab_error(cachep, "end of a freed object " | |
1898 | "was overwritten"); | |
1899 | } | |
1900 | } | |
1901 | } | |
1902 | #else | |
1903 | static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp) | |
1904 | { | |
1905 | } | |
1906 | #endif | |
1907 | ||
1908 | /** | |
1909 | * slab_destroy - destroy and release all objects in a slab | |
1910 | * @cachep: cache pointer being destroyed | |
1911 | * @slabp: slab pointer being destroyed | |
1912 | * | |
1913 | * Destroy all the objs in a slab, and release the mem back to the system. | |
1914 | * Before calling the slab must have been unlinked from the cache. The | |
1915 | * cache-lock is not held/needed. | |
1916 | */ | |
1917 | static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) | |
1918 | { | |
1919 | void *addr = slabp->s_mem - slabp->colouroff; | |
1920 | ||
1921 | slab_destroy_objs(cachep, slabp); | |
1922 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { | |
1923 | struct slab_rcu *slab_rcu; | |
1924 | ||
1925 | slab_rcu = (struct slab_rcu *)slabp; | |
1926 | slab_rcu->cachep = cachep; | |
1927 | slab_rcu->addr = addr; | |
1928 | call_rcu(&slab_rcu->head, kmem_rcu_free); | |
1929 | } else { | |
1930 | kmem_freepages(cachep, addr); | |
1931 | if (OFF_SLAB(cachep)) | |
1932 | kmem_cache_free(cachep->slabp_cache, slabp); | |
1933 | } | |
1934 | } | |
1935 | ||
1936 | /* | |
1937 | * For setting up all the kmem_list3s for cache whose buffer_size is same as | |
1938 | * size of kmem_list3. | |
1939 | */ | |
1940 | static void __init set_up_list3s(struct kmem_cache *cachep, int index) | |
1941 | { | |
1942 | int node; | |
1943 | ||
1944 | for_each_online_node(node) { | |
1945 | cachep->nodelists[node] = &initkmem_list3[index + node]; | |
1946 | cachep->nodelists[node]->next_reap = jiffies + | |
1947 | REAPTIMEOUT_LIST3 + | |
1948 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
1949 | } | |
1950 | } | |
1951 | ||
1952 | static void __kmem_cache_destroy(struct kmem_cache *cachep) | |
1953 | { | |
1954 | int i; | |
1955 | struct kmem_list3 *l3; | |
1956 | ||
1957 | for_each_online_cpu(i) | |
1958 | kfree(cachep->array[i]); | |
1959 | ||
1960 | /* NUMA: free the list3 structures */ | |
1961 | for_each_online_node(i) { | |
1962 | l3 = cachep->nodelists[i]; | |
1963 | if (l3) { | |
1964 | kfree(l3->shared); | |
1965 | free_alien_cache(l3->alien); | |
1966 | kfree(l3); | |
1967 | } | |
1968 | } | |
1969 | kmem_cache_free(&cache_cache, cachep); | |
1970 | } | |
1971 | ||
1972 | ||
1973 | /** | |
1974 | * calculate_slab_order - calculate size (page order) of slabs | |
1975 | * @cachep: pointer to the cache that is being created | |
1976 | * @size: size of objects to be created in this cache. | |
1977 | * @align: required alignment for the objects. | |
1978 | * @flags: slab allocation flags | |
1979 | * | |
1980 | * Also calculates the number of objects per slab. | |
1981 | * | |
1982 | * This could be made much more intelligent. For now, try to avoid using | |
1983 | * high order pages for slabs. When the gfp() functions are more friendly | |
1984 | * towards high-order requests, this should be changed. | |
1985 | */ | |
1986 | static size_t calculate_slab_order(struct kmem_cache *cachep, | |
1987 | size_t size, size_t align, unsigned long flags) | |
1988 | { | |
1989 | unsigned long offslab_limit; | |
1990 | size_t left_over = 0; | |
1991 | int gfporder; | |
1992 | ||
1993 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { | |
1994 | unsigned int num; | |
1995 | size_t remainder; | |
1996 | ||
1997 | cache_estimate(gfporder, size, align, flags, &remainder, &num); | |
1998 | if (!num) | |
1999 | continue; | |
2000 | ||
2001 | if (flags & CFLGS_OFF_SLAB) { | |
2002 | /* | |
2003 | * Max number of objs-per-slab for caches which | |
2004 | * use off-slab slabs. Needed to avoid a possible | |
2005 | * looping condition in cache_grow(). | |
2006 | */ | |
2007 | offslab_limit = size - sizeof(struct slab); | |
2008 | offslab_limit /= sizeof(kmem_bufctl_t); | |
2009 | ||
2010 | if (num > offslab_limit) | |
2011 | break; | |
2012 | } | |
2013 | ||
2014 | /* Found something acceptable - save it away */ | |
2015 | cachep->num = num; | |
2016 | cachep->gfporder = gfporder; | |
2017 | left_over = remainder; | |
2018 | ||
2019 | /* | |
2020 | * A VFS-reclaimable slab tends to have most allocations | |
2021 | * as GFP_NOFS and we really don't want to have to be allocating | |
2022 | * higher-order pages when we are unable to shrink dcache. | |
2023 | */ | |
2024 | if (flags & SLAB_RECLAIM_ACCOUNT) | |
2025 | break; | |
2026 | ||
2027 | /* | |
2028 | * Large number of objects is good, but very large slabs are | |
2029 | * currently bad for the gfp()s. | |
2030 | */ | |
2031 | if (gfporder >= slab_break_gfp_order) | |
2032 | break; | |
2033 | ||
2034 | /* | |
2035 | * Acceptable internal fragmentation? | |
2036 | */ | |
2037 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) | |
2038 | break; | |
2039 | } | |
2040 | return left_over; | |
2041 | } | |
2042 | ||
2043 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep) | |
2044 | { | |
2045 | if (g_cpucache_up == FULL) | |
2046 | return enable_cpucache(cachep); | |
2047 | ||
2048 | if (g_cpucache_up == NONE) { | |
2049 | /* | |
2050 | * Note: the first kmem_cache_create must create the cache | |
2051 | * that's used by kmalloc(24), otherwise the creation of | |
2052 | * further caches will BUG(). | |
2053 | */ | |
2054 | cachep->array[smp_processor_id()] = &initarray_generic.cache; | |
2055 | ||
2056 | /* | |
2057 | * If the cache that's used by kmalloc(sizeof(kmem_list3)) is | |
2058 | * the first cache, then we need to set up all its list3s, | |
2059 | * otherwise the creation of further caches will BUG(). | |
2060 | */ | |
2061 | set_up_list3s(cachep, SIZE_AC); | |
2062 | if (INDEX_AC == INDEX_L3) | |
2063 | g_cpucache_up = PARTIAL_L3; | |
2064 | else | |
2065 | g_cpucache_up = PARTIAL_AC; | |
2066 | } else { | |
2067 | cachep->array[smp_processor_id()] = | |
2068 | kmalloc(sizeof(struct arraycache_init), GFP_KERNEL); | |
2069 | ||
2070 | if (g_cpucache_up == PARTIAL_AC) { | |
2071 | set_up_list3s(cachep, SIZE_L3); | |
2072 | g_cpucache_up = PARTIAL_L3; | |
2073 | } else { | |
2074 | int node; | |
2075 | for_each_online_node(node) { | |
2076 | cachep->nodelists[node] = | |
2077 | kmalloc_node(sizeof(struct kmem_list3), | |
2078 | GFP_KERNEL, node); | |
2079 | BUG_ON(!cachep->nodelists[node]); | |
2080 | kmem_list3_init(cachep->nodelists[node]); | |
2081 | } | |
2082 | } | |
2083 | } | |
2084 | cachep->nodelists[numa_node_id()]->next_reap = | |
2085 | jiffies + REAPTIMEOUT_LIST3 + | |
2086 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
2087 | ||
2088 | cpu_cache_get(cachep)->avail = 0; | |
2089 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; | |
2090 | cpu_cache_get(cachep)->batchcount = 1; | |
2091 | cpu_cache_get(cachep)->touched = 0; | |
2092 | cachep->batchcount = 1; | |
2093 | cachep->limit = BOOT_CPUCACHE_ENTRIES; | |
2094 | return 0; | |
2095 | } | |
2096 | ||
2097 | /** | |
2098 | * kmem_cache_create - Create a cache. | |
2099 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
2100 | * @size: The size of objects to be created in this cache. | |
2101 | * @align: The required alignment for the objects. | |
2102 | * @flags: SLAB flags | |
2103 | * @ctor: A constructor for the objects. | |
2104 | * @dtor: A destructor for the objects (not implemented anymore). | |
2105 | * | |
2106 | * Returns a ptr to the cache on success, NULL on failure. | |
2107 | * Cannot be called within a int, but can be interrupted. | |
2108 | * The @ctor is run when new pages are allocated by the cache | |
2109 | * and the @dtor is run before the pages are handed back. | |
2110 | * | |
2111 | * @name must be valid until the cache is destroyed. This implies that | |
2112 | * the module calling this has to destroy the cache before getting unloaded. | |
2113 | * | |
2114 | * The flags are | |
2115 | * | |
2116 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
2117 | * to catch references to uninitialised memory. | |
2118 | * | |
2119 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
2120 | * for buffer overruns. | |
2121 | * | |
2122 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
2123 | * cacheline. This can be beneficial if you're counting cycles as closely | |
2124 | * as davem. | |
2125 | */ | |
2126 | struct kmem_cache * | |
2127 | kmem_cache_create (const char *name, size_t size, size_t align, | |
2128 | unsigned long flags, | |
2129 | void (*ctor)(void*, struct kmem_cache *, unsigned long), | |
2130 | void (*dtor)(void*, struct kmem_cache *, unsigned long)) | |
2131 | { | |
2132 | size_t left_over, slab_size, ralign; | |
2133 | struct kmem_cache *cachep = NULL, *pc; | |
2134 | ||
2135 | /* | |
2136 | * Sanity checks... these are all serious usage bugs. | |
2137 | */ | |
2138 | if (!name || in_interrupt() || (size < BYTES_PER_WORD) || | |
2139 | size > KMALLOC_MAX_SIZE || dtor) { | |
2140 | printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__, | |
2141 | name); | |
2142 | BUG(); | |
2143 | } | |
2144 | ||
2145 | /* | |
2146 | * We use cache_chain_mutex to ensure a consistent view of | |
2147 | * cpu_online_map as well. Please see cpuup_callback | |
2148 | */ | |
2149 | mutex_lock(&cache_chain_mutex); | |
2150 | ||
2151 | list_for_each_entry(pc, &cache_chain, next) { | |
2152 | char tmp; | |
2153 | int res; | |
2154 | ||
2155 | /* | |
2156 | * This happens when the module gets unloaded and doesn't | |
2157 | * destroy its slab cache and no-one else reuses the vmalloc | |
2158 | * area of the module. Print a warning. | |
2159 | */ | |
2160 | res = probe_kernel_address(pc->name, tmp); | |
2161 | if (res) { | |
2162 | printk(KERN_ERR | |
2163 | "SLAB: cache with size %d has lost its name\n", | |
2164 | pc->buffer_size); | |
2165 | continue; | |
2166 | } | |
2167 | ||
2168 | if (!strcmp(pc->name, name)) { | |
2169 | printk(KERN_ERR | |
2170 | "kmem_cache_create: duplicate cache %s\n", name); | |
2171 | dump_stack(); | |
2172 | goto oops; | |
2173 | } | |
2174 | } | |
2175 | ||
2176 | #if DEBUG | |
2177 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ | |
2178 | #if FORCED_DEBUG | |
2179 | /* | |
2180 | * Enable redzoning and last user accounting, except for caches with | |
2181 | * large objects, if the increased size would increase the object size | |
2182 | * above the next power of two: caches with object sizes just above a | |
2183 | * power of two have a significant amount of internal fragmentation. | |
2184 | */ | |
2185 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + | |
2186 | 2 * sizeof(unsigned long long))) | |
2187 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; | |
2188 | if (!(flags & SLAB_DESTROY_BY_RCU)) | |
2189 | flags |= SLAB_POISON; | |
2190 | #endif | |
2191 | if (flags & SLAB_DESTROY_BY_RCU) | |
2192 | BUG_ON(flags & SLAB_POISON); | |
2193 | #endif | |
2194 | /* | |
2195 | * Always checks flags, a caller might be expecting debug support which | |
2196 | * isn't available. | |
2197 | */ | |
2198 | BUG_ON(flags & ~CREATE_MASK); | |
2199 | ||
2200 | /* | |
2201 | * Check that size is in terms of words. This is needed to avoid | |
2202 | * unaligned accesses for some archs when redzoning is used, and makes | |
2203 | * sure any on-slab bufctl's are also correctly aligned. | |
2204 | */ | |
2205 | if (size & (BYTES_PER_WORD - 1)) { | |
2206 | size += (BYTES_PER_WORD - 1); | |
2207 | size &= ~(BYTES_PER_WORD - 1); | |
2208 | } | |
2209 | ||
2210 | /* calculate the final buffer alignment: */ | |
2211 | ||
2212 | /* 1) arch recommendation: can be overridden for debug */ | |
2213 | if (flags & SLAB_HWCACHE_ALIGN) { | |
2214 | /* | |
2215 | * Default alignment: as specified by the arch code. Except if | |
2216 | * an object is really small, then squeeze multiple objects into | |
2217 | * one cacheline. | |
2218 | */ | |
2219 | ralign = cache_line_size(); | |
2220 | while (size <= ralign / 2) | |
2221 | ralign /= 2; | |
2222 | } else { | |
2223 | ralign = BYTES_PER_WORD; | |
2224 | } | |
2225 | ||
2226 | /* | |
2227 | * Redzoning and user store require word alignment or possibly larger. | |
2228 | * Note this will be overridden by architecture or caller mandated | |
2229 | * alignment if either is greater than BYTES_PER_WORD. | |
2230 | */ | |
2231 | if (flags & SLAB_STORE_USER) | |
2232 | ralign = BYTES_PER_WORD; | |
2233 | ||
2234 | if (flags & SLAB_RED_ZONE) { | |
2235 | ralign = REDZONE_ALIGN; | |
2236 | /* If redzoning, ensure that the second redzone is suitably | |
2237 | * aligned, by adjusting the object size accordingly. */ | |
2238 | size += REDZONE_ALIGN - 1; | |
2239 | size &= ~(REDZONE_ALIGN - 1); | |
2240 | } | |
2241 | ||
2242 | /* 2) arch mandated alignment */ | |
2243 | if (ralign < ARCH_SLAB_MINALIGN) { | |
2244 | ralign = ARCH_SLAB_MINALIGN; | |
2245 | } | |
2246 | /* 3) caller mandated alignment */ | |
2247 | if (ralign < align) { | |
2248 | ralign = align; | |
2249 | } | |
2250 | /* disable debug if necessary */ | |
2251 | if (ralign > __alignof__(unsigned long long)) | |
2252 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); | |
2253 | /* | |
2254 | * 4) Store it. | |
2255 | */ | |
2256 | align = ralign; | |
2257 | ||
2258 | /* Get cache's description obj. */ | |
2259 | cachep = kmem_cache_zalloc(&cache_cache, GFP_KERNEL); | |
2260 | if (!cachep) | |
2261 | goto oops; | |
2262 | ||
2263 | #if DEBUG | |
2264 | cachep->obj_size = size; | |
2265 | ||
2266 | /* | |
2267 | * Both debugging options require word-alignment which is calculated | |
2268 | * into align above. | |
2269 | */ | |
2270 | if (flags & SLAB_RED_ZONE) { | |
2271 | /* add space for red zone words */ | |
2272 | cachep->obj_offset += sizeof(unsigned long long); | |
2273 | size += 2 * sizeof(unsigned long long); | |
2274 | } | |
2275 | if (flags & SLAB_STORE_USER) { | |
2276 | /* user store requires one word storage behind the end of | |
2277 | * the real object. But if the second red zone needs to be | |
2278 | * aligned to 64 bits, we must allow that much space. | |
2279 | */ | |
2280 | if (flags & SLAB_RED_ZONE) | |
2281 | size += REDZONE_ALIGN; | |
2282 | else | |
2283 | size += BYTES_PER_WORD; | |
2284 | } | |
2285 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) | |
2286 | if (size >= malloc_sizes[INDEX_L3 + 1].cs_size | |
2287 | && cachep->obj_size > cache_line_size() && size < PAGE_SIZE) { | |
2288 | cachep->obj_offset += PAGE_SIZE - size; | |
2289 | size = PAGE_SIZE; | |
2290 | } | |
2291 | #endif | |
2292 | #endif | |
2293 | ||
2294 | /* | |
2295 | * Determine if the slab management is 'on' or 'off' slab. | |
2296 | * (bootstrapping cannot cope with offslab caches so don't do | |
2297 | * it too early on.) | |
2298 | */ | |
2299 | if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init) | |
2300 | /* | |
2301 | * Size is large, assume best to place the slab management obj | |
2302 | * off-slab (should allow better packing of objs). | |
2303 | */ | |
2304 | flags |= CFLGS_OFF_SLAB; | |
2305 | ||
2306 | size = ALIGN(size, align); | |
2307 | ||
2308 | left_over = calculate_slab_order(cachep, size, align, flags); | |
2309 | ||
2310 | if (!cachep->num) { | |
2311 | printk(KERN_ERR | |
2312 | "kmem_cache_create: couldn't create cache %s.\n", name); | |
2313 | kmem_cache_free(&cache_cache, cachep); | |
2314 | cachep = NULL; | |
2315 | goto oops; | |
2316 | } | |
2317 | slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) | |
2318 | + sizeof(struct slab), align); | |
2319 | ||
2320 | /* | |
2321 | * If the slab has been placed off-slab, and we have enough space then | |
2322 | * move it on-slab. This is at the expense of any extra colouring. | |
2323 | */ | |
2324 | if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { | |
2325 | flags &= ~CFLGS_OFF_SLAB; | |
2326 | left_over -= slab_size; | |
2327 | } | |
2328 | ||
2329 | if (flags & CFLGS_OFF_SLAB) { | |
2330 | /* really off slab. No need for manual alignment */ | |
2331 | slab_size = | |
2332 | cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); | |
2333 | } | |
2334 | ||
2335 | cachep->colour_off = cache_line_size(); | |
2336 | /* Offset must be a multiple of the alignment. */ | |
2337 | if (cachep->colour_off < align) | |
2338 | cachep->colour_off = align; | |
2339 | cachep->colour = left_over / cachep->colour_off; | |
2340 | cachep->slab_size = slab_size; | |
2341 | cachep->flags = flags; | |
2342 | cachep->gfpflags = 0; | |
2343 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) | |
2344 | cachep->gfpflags |= GFP_DMA; | |
2345 | cachep->buffer_size = size; | |
2346 | cachep->reciprocal_buffer_size = reciprocal_value(size); | |
2347 | ||
2348 | if (flags & CFLGS_OFF_SLAB) { | |
2349 | cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); | |
2350 | /* | |
2351 | * This is a possibility for one of the malloc_sizes caches. | |
2352 | * But since we go off slab only for object size greater than | |
2353 | * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, | |
2354 | * this should not happen at all. | |
2355 | * But leave a BUG_ON for some lucky dude. | |
2356 | */ | |
2357 | BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); | |
2358 | } | |
2359 | cachep->ctor = ctor; | |
2360 | cachep->name = name; | |
2361 | ||
2362 | if (setup_cpu_cache(cachep)) { | |
2363 | __kmem_cache_destroy(cachep); | |
2364 | cachep = NULL; | |
2365 | goto oops; | |
2366 | } | |
2367 | ||
2368 | /* cache setup completed, link it into the list */ | |
2369 | list_add(&cachep->next, &cache_chain); | |
2370 | oops: | |
2371 | if (!cachep && (flags & SLAB_PANIC)) | |
2372 | panic("kmem_cache_create(): failed to create slab `%s'\n", | |
2373 | name); | |
2374 | mutex_unlock(&cache_chain_mutex); | |
2375 | return cachep; | |
2376 | } | |
2377 | EXPORT_SYMBOL(kmem_cache_create); | |
2378 | ||
2379 | #if DEBUG | |
2380 | static void check_irq_off(void) | |
2381 | { | |
2382 | BUG_ON(!irqs_disabled()); | |
2383 | } | |
2384 | ||
2385 | static void check_irq_on(void) | |
2386 | { | |
2387 | BUG_ON(irqs_disabled()); | |
2388 | } | |
2389 | ||
2390 | static void check_spinlock_acquired(struct kmem_cache *cachep) | |
2391 | { | |
2392 | #ifdef CONFIG_SMP | |
2393 | check_irq_off(); | |
2394 | assert_spin_locked(&cachep->nodelists[numa_node_id()]->list_lock); | |
2395 | #endif | |
2396 | } | |
2397 | ||
2398 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) | |
2399 | { | |
2400 | #ifdef CONFIG_SMP | |
2401 | check_irq_off(); | |
2402 | assert_spin_locked(&cachep->nodelists[node]->list_lock); | |
2403 | #endif | |
2404 | } | |
2405 | ||
2406 | #else | |
2407 | #define check_irq_off() do { } while(0) | |
2408 | #define check_irq_on() do { } while(0) | |
2409 | #define check_spinlock_acquired(x) do { } while(0) | |
2410 | #define check_spinlock_acquired_node(x, y) do { } while(0) | |
2411 | #endif | |
2412 | ||
2413 | static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, | |
2414 | struct array_cache *ac, | |
2415 | int force, int node); | |
2416 | ||
2417 | static void do_drain(void *arg) | |
2418 | { | |
2419 | struct kmem_cache *cachep = arg; | |
2420 | struct array_cache *ac; | |
2421 | int node = numa_node_id(); | |
2422 | ||
2423 | check_irq_off(); | |
2424 | ac = cpu_cache_get(cachep); | |
2425 | spin_lock(&cachep->nodelists[node]->list_lock); | |
2426 | free_block(cachep, ac->entry, ac->avail, node); | |
2427 | spin_unlock(&cachep->nodelists[node]->list_lock); | |
2428 | ac->avail = 0; | |
2429 | } | |
2430 | ||
2431 | static void drain_cpu_caches(struct kmem_cache *cachep) | |
2432 | { | |
2433 | struct kmem_list3 *l3; | |
2434 | int node; | |
2435 | ||
2436 | on_each_cpu(do_drain, cachep, 1, 1); | |
2437 | check_irq_on(); | |
2438 | for_each_online_node(node) { | |
2439 | l3 = cachep->nodelists[node]; | |
2440 | if (l3 && l3->alien) | |
2441 | drain_alien_cache(cachep, l3->alien); | |
2442 | } | |
2443 | ||
2444 | for_each_online_node(node) { | |
2445 | l3 = cachep->nodelists[node]; | |
2446 | if (l3) | |
2447 | drain_array(cachep, l3, l3->shared, 1, node); | |
2448 | } | |
2449 | } | |
2450 | ||
2451 | /* | |
2452 | * Remove slabs from the list of free slabs. | |
2453 | * Specify the number of slabs to drain in tofree. | |
2454 | * | |
2455 | * Returns the actual number of slabs released. | |
2456 | */ | |
2457 | static int drain_freelist(struct kmem_cache *cache, | |
2458 | struct kmem_list3 *l3, int tofree) | |
2459 | { | |
2460 | struct list_head *p; | |
2461 | int nr_freed; | |
2462 | struct slab *slabp; | |
2463 | ||
2464 | nr_freed = 0; | |
2465 | while (nr_freed < tofree && !list_empty(&l3->slabs_free)) { | |
2466 | ||
2467 | spin_lock_irq(&l3->list_lock); | |
2468 | p = l3->slabs_free.prev; | |
2469 | if (p == &l3->slabs_free) { | |
2470 | spin_unlock_irq(&l3->list_lock); | |
2471 | goto out; | |
2472 | } | |
2473 | ||
2474 | slabp = list_entry(p, struct slab, list); | |
2475 | #if DEBUG | |
2476 | BUG_ON(slabp->inuse); | |
2477 | #endif | |
2478 | list_del(&slabp->list); | |
2479 | /* | |
2480 | * Safe to drop the lock. The slab is no longer linked | |
2481 | * to the cache. | |
2482 | */ | |
2483 | l3->free_objects -= cache->num; | |
2484 | spin_unlock_irq(&l3->list_lock); | |
2485 | slab_destroy(cache, slabp); | |
2486 | nr_freed++; | |
2487 | } | |
2488 | out: | |
2489 | return nr_freed; | |
2490 | } | |
2491 | ||
2492 | /* Called with cache_chain_mutex held to protect against cpu hotplug */ | |
2493 | static int __cache_shrink(struct kmem_cache *cachep) | |
2494 | { | |
2495 | int ret = 0, i = 0; | |
2496 | struct kmem_list3 *l3; | |
2497 | ||
2498 | drain_cpu_caches(cachep); | |
2499 | ||
2500 | check_irq_on(); | |
2501 | for_each_online_node(i) { | |
2502 | l3 = cachep->nodelists[i]; | |
2503 | if (!l3) | |
2504 | continue; | |
2505 | ||
2506 | drain_freelist(cachep, l3, l3->free_objects); | |
2507 | ||
2508 | ret += !list_empty(&l3->slabs_full) || | |
2509 | !list_empty(&l3->slabs_partial); | |
2510 | } | |
2511 | return (ret ? 1 : 0); | |
2512 | } | |
2513 | ||
2514 | /** | |
2515 | * kmem_cache_shrink - Shrink a cache. | |
2516 | * @cachep: The cache to shrink. | |
2517 | * | |
2518 | * Releases as many slabs as possible for a cache. | |
2519 | * To help debugging, a zero exit status indicates all slabs were released. | |
2520 | */ | |
2521 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
2522 | { | |
2523 | int ret; | |
2524 | BUG_ON(!cachep || in_interrupt()); | |
2525 | ||
2526 | mutex_lock(&cache_chain_mutex); | |
2527 | ret = __cache_shrink(cachep); | |
2528 | mutex_unlock(&cache_chain_mutex); | |
2529 | return ret; | |
2530 | } | |
2531 | EXPORT_SYMBOL(kmem_cache_shrink); | |
2532 | ||
2533 | /** | |
2534 | * kmem_cache_destroy - delete a cache | |
2535 | * @cachep: the cache to destroy | |
2536 | * | |
2537 | * Remove a &struct kmem_cache object from the slab cache. | |
2538 | * | |
2539 | * It is expected this function will be called by a module when it is | |
2540 | * unloaded. This will remove the cache completely, and avoid a duplicate | |
2541 | * cache being allocated each time a module is loaded and unloaded, if the | |
2542 | * module doesn't have persistent in-kernel storage across loads and unloads. | |
2543 | * | |
2544 | * The cache must be empty before calling this function. | |
2545 | * | |
2546 | * The caller must guarantee that noone will allocate memory from the cache | |
2547 | * during the kmem_cache_destroy(). | |
2548 | */ | |
2549 | void kmem_cache_destroy(struct kmem_cache *cachep) | |
2550 | { | |
2551 | BUG_ON(!cachep || in_interrupt()); | |
2552 | ||
2553 | /* Find the cache in the chain of caches. */ | |
2554 | mutex_lock(&cache_chain_mutex); | |
2555 | /* | |
2556 | * the chain is never empty, cache_cache is never destroyed | |
2557 | */ | |
2558 | list_del(&cachep->next); | |
2559 | if (__cache_shrink(cachep)) { | |
2560 | slab_error(cachep, "Can't free all objects"); | |
2561 | list_add(&cachep->next, &cache_chain); | |
2562 | mutex_unlock(&cache_chain_mutex); | |
2563 | return; | |
2564 | } | |
2565 | ||
2566 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) | |
2567 | synchronize_rcu(); | |
2568 | ||
2569 | __kmem_cache_destroy(cachep); | |
2570 | mutex_unlock(&cache_chain_mutex); | |
2571 | } | |
2572 | EXPORT_SYMBOL(kmem_cache_destroy); | |
2573 | ||
2574 | /* | |
2575 | * Get the memory for a slab management obj. | |
2576 | * For a slab cache when the slab descriptor is off-slab, slab descriptors | |
2577 | * always come from malloc_sizes caches. The slab descriptor cannot | |
2578 | * come from the same cache which is getting created because, | |
2579 | * when we are searching for an appropriate cache for these | |
2580 | * descriptors in kmem_cache_create, we search through the malloc_sizes array. | |
2581 | * If we are creating a malloc_sizes cache here it would not be visible to | |
2582 | * kmem_find_general_cachep till the initialization is complete. | |
2583 | * Hence we cannot have slabp_cache same as the original cache. | |
2584 | */ | |
2585 | static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, | |
2586 | int colour_off, gfp_t local_flags, | |
2587 | int nodeid) | |
2588 | { | |
2589 | struct slab *slabp; | |
2590 | ||
2591 | if (OFF_SLAB(cachep)) { | |
2592 | /* Slab management obj is off-slab. */ | |
2593 | slabp = kmem_cache_alloc_node(cachep->slabp_cache, | |
2594 | local_flags & ~GFP_THISNODE, nodeid); | |
2595 | if (!slabp) | |
2596 | return NULL; | |
2597 | } else { | |
2598 | slabp = objp + colour_off; | |
2599 | colour_off += cachep->slab_size; | |
2600 | } | |
2601 | slabp->inuse = 0; | |
2602 | slabp->colouroff = colour_off; | |
2603 | slabp->s_mem = objp + colour_off; | |
2604 | slabp->nodeid = nodeid; | |
2605 | return slabp; | |
2606 | } | |
2607 | ||
2608 | static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) | |
2609 | { | |
2610 | return (kmem_bufctl_t *) (slabp + 1); | |
2611 | } | |
2612 | ||
2613 | static void cache_init_objs(struct kmem_cache *cachep, | |
2614 | struct slab *slabp) | |
2615 | { | |
2616 | int i; | |
2617 | ||
2618 | for (i = 0; i < cachep->num; i++) { | |
2619 | void *objp = index_to_obj(cachep, slabp, i); | |
2620 | #if DEBUG | |
2621 | /* need to poison the objs? */ | |
2622 | if (cachep->flags & SLAB_POISON) | |
2623 | poison_obj(cachep, objp, POISON_FREE); | |
2624 | if (cachep->flags & SLAB_STORE_USER) | |
2625 | *dbg_userword(cachep, objp) = NULL; | |
2626 | ||
2627 | if (cachep->flags & SLAB_RED_ZONE) { | |
2628 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2629 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2630 | } | |
2631 | /* | |
2632 | * Constructors are not allowed to allocate memory from the same | |
2633 | * cache which they are a constructor for. Otherwise, deadlock. | |
2634 | * They must also be threaded. | |
2635 | */ | |
2636 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) | |
2637 | cachep->ctor(objp + obj_offset(cachep), cachep, | |
2638 | 0); | |
2639 | ||
2640 | if (cachep->flags & SLAB_RED_ZONE) { | |
2641 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
2642 | slab_error(cachep, "constructor overwrote the" | |
2643 | " end of an object"); | |
2644 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
2645 | slab_error(cachep, "constructor overwrote the" | |
2646 | " start of an object"); | |
2647 | } | |
2648 | if ((cachep->buffer_size % PAGE_SIZE) == 0 && | |
2649 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) | |
2650 | kernel_map_pages(virt_to_page(objp), | |
2651 | cachep->buffer_size / PAGE_SIZE, 0); | |
2652 | #else | |
2653 | if (cachep->ctor) | |
2654 | cachep->ctor(objp, cachep, 0); | |
2655 | #endif | |
2656 | slab_bufctl(slabp)[i] = i + 1; | |
2657 | } | |
2658 | slab_bufctl(slabp)[i - 1] = BUFCTL_END; | |
2659 | slabp->free = 0; | |
2660 | } | |
2661 | ||
2662 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) | |
2663 | { | |
2664 | if (CONFIG_ZONE_DMA_FLAG) { | |
2665 | if (flags & GFP_DMA) | |
2666 | BUG_ON(!(cachep->gfpflags & GFP_DMA)); | |
2667 | else | |
2668 | BUG_ON(cachep->gfpflags & GFP_DMA); | |
2669 | } | |
2670 | } | |
2671 | ||
2672 | static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, | |
2673 | int nodeid) | |
2674 | { | |
2675 | void *objp = index_to_obj(cachep, slabp, slabp->free); | |
2676 | kmem_bufctl_t next; | |
2677 | ||
2678 | slabp->inuse++; | |
2679 | next = slab_bufctl(slabp)[slabp->free]; | |
2680 | #if DEBUG | |
2681 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; | |
2682 | WARN_ON(slabp->nodeid != nodeid); | |
2683 | #endif | |
2684 | slabp->free = next; | |
2685 | ||
2686 | return objp; | |
2687 | } | |
2688 | ||
2689 | static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, | |
2690 | void *objp, int nodeid) | |
2691 | { | |
2692 | unsigned int objnr = obj_to_index(cachep, slabp, objp); | |
2693 | ||
2694 | #if DEBUG | |
2695 | /* Verify that the slab belongs to the intended node */ | |
2696 | WARN_ON(slabp->nodeid != nodeid); | |
2697 | ||
2698 | if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { | |
2699 | printk(KERN_ERR "slab: double free detected in cache " | |
2700 | "'%s', objp %p\n", cachep->name, objp); | |
2701 | BUG(); | |
2702 | } | |
2703 | #endif | |
2704 | slab_bufctl(slabp)[objnr] = slabp->free; | |
2705 | slabp->free = objnr; | |
2706 | slabp->inuse--; | |
2707 | } | |
2708 | ||
2709 | /* | |
2710 | * Map pages beginning at addr to the given cache and slab. This is required | |
2711 | * for the slab allocator to be able to lookup the cache and slab of a | |
2712 | * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging. | |
2713 | */ | |
2714 | static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, | |
2715 | void *addr) | |
2716 | { | |
2717 | int nr_pages; | |
2718 | struct page *page; | |
2719 | ||
2720 | page = virt_to_page(addr); | |
2721 | ||
2722 | nr_pages = 1; | |
2723 | if (likely(!PageCompound(page))) | |
2724 | nr_pages <<= cache->gfporder; | |
2725 | ||
2726 | do { | |
2727 | page_set_cache(page, cache); | |
2728 | page_set_slab(page, slab); | |
2729 | page++; | |
2730 | } while (--nr_pages); | |
2731 | } | |
2732 | ||
2733 | /* | |
2734 | * Grow (by 1) the number of slabs within a cache. This is called by | |
2735 | * kmem_cache_alloc() when there are no active objs left in a cache. | |
2736 | */ | |
2737 | static int cache_grow(struct kmem_cache *cachep, | |
2738 | gfp_t flags, int nodeid, void *objp) | |
2739 | { | |
2740 | struct slab *slabp; | |
2741 | size_t offset; | |
2742 | gfp_t local_flags; | |
2743 | struct kmem_list3 *l3; | |
2744 | ||
2745 | /* | |
2746 | * Be lazy and only check for valid flags here, keeping it out of the | |
2747 | * critical path in kmem_cache_alloc(). | |
2748 | */ | |
2749 | BUG_ON(flags & ~(GFP_DMA | __GFP_ZERO | GFP_LEVEL_MASK)); | |
2750 | ||
2751 | local_flags = (flags & GFP_LEVEL_MASK); | |
2752 | /* Take the l3 list lock to change the colour_next on this node */ | |
2753 | check_irq_off(); | |
2754 | l3 = cachep->nodelists[nodeid]; | |
2755 | spin_lock(&l3->list_lock); | |
2756 | ||
2757 | /* Get colour for the slab, and cal the next value. */ | |
2758 | offset = l3->colour_next; | |
2759 | l3->colour_next++; | |
2760 | if (l3->colour_next >= cachep->colour) | |
2761 | l3->colour_next = 0; | |
2762 | spin_unlock(&l3->list_lock); | |
2763 | ||
2764 | offset *= cachep->colour_off; | |
2765 | ||
2766 | if (local_flags & __GFP_WAIT) | |
2767 | local_irq_enable(); | |
2768 | ||
2769 | /* | |
2770 | * The test for missing atomic flag is performed here, rather than | |
2771 | * the more obvious place, simply to reduce the critical path length | |
2772 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they | |
2773 | * will eventually be caught here (where it matters). | |
2774 | */ | |
2775 | kmem_flagcheck(cachep, flags); | |
2776 | ||
2777 | /* | |
2778 | * Get mem for the objs. Attempt to allocate a physical page from | |
2779 | * 'nodeid'. | |
2780 | */ | |
2781 | if (!objp) | |
2782 | objp = kmem_getpages(cachep, flags, nodeid); | |
2783 | if (!objp) | |
2784 | goto failed; | |
2785 | ||
2786 | /* Get slab management. */ | |
2787 | slabp = alloc_slabmgmt(cachep, objp, offset, | |
2788 | local_flags & ~GFP_THISNODE, nodeid); | |
2789 | if (!slabp) | |
2790 | goto opps1; | |
2791 | ||
2792 | slabp->nodeid = nodeid; | |
2793 | slab_map_pages(cachep, slabp, objp); | |
2794 | ||
2795 | cache_init_objs(cachep, slabp); | |
2796 | ||
2797 | if (local_flags & __GFP_WAIT) | |
2798 | local_irq_disable(); | |
2799 | check_irq_off(); | |
2800 | spin_lock(&l3->list_lock); | |
2801 | ||
2802 | /* Make slab active. */ | |
2803 | list_add_tail(&slabp->list, &(l3->slabs_free)); | |
2804 | STATS_INC_GROWN(cachep); | |
2805 | l3->free_objects += cachep->num; | |
2806 | spin_unlock(&l3->list_lock); | |
2807 | return 1; | |
2808 | opps1: | |
2809 | kmem_freepages(cachep, objp); | |
2810 | failed: | |
2811 | if (local_flags & __GFP_WAIT) | |
2812 | local_irq_disable(); | |
2813 | return 0; | |
2814 | } | |
2815 | ||
2816 | #if DEBUG | |
2817 | ||
2818 | /* | |
2819 | * Perform extra freeing checks: | |
2820 | * - detect bad pointers. | |
2821 | * - POISON/RED_ZONE checking | |
2822 | */ | |
2823 | static void kfree_debugcheck(const void *objp) | |
2824 | { | |
2825 | if (!virt_addr_valid(objp)) { | |
2826 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", | |
2827 | (unsigned long)objp); | |
2828 | BUG(); | |
2829 | } | |
2830 | } | |
2831 | ||
2832 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) | |
2833 | { | |
2834 | unsigned long long redzone1, redzone2; | |
2835 | ||
2836 | redzone1 = *dbg_redzone1(cache, obj); | |
2837 | redzone2 = *dbg_redzone2(cache, obj); | |
2838 | ||
2839 | /* | |
2840 | * Redzone is ok. | |
2841 | */ | |
2842 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) | |
2843 | return; | |
2844 | ||
2845 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) | |
2846 | slab_error(cache, "double free detected"); | |
2847 | else | |
2848 | slab_error(cache, "memory outside object was overwritten"); | |
2849 | ||
2850 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", | |
2851 | obj, redzone1, redzone2); | |
2852 | } | |
2853 | ||
2854 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, | |
2855 | void *caller) | |
2856 | { | |
2857 | struct page *page; | |
2858 | unsigned int objnr; | |
2859 | struct slab *slabp; | |
2860 | ||
2861 | objp -= obj_offset(cachep); | |
2862 | kfree_debugcheck(objp); | |
2863 | page = virt_to_head_page(objp); | |
2864 | ||
2865 | slabp = page_get_slab(page); | |
2866 | ||
2867 | if (cachep->flags & SLAB_RED_ZONE) { | |
2868 | verify_redzone_free(cachep, objp); | |
2869 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2870 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2871 | } | |
2872 | if (cachep->flags & SLAB_STORE_USER) | |
2873 | *dbg_userword(cachep, objp) = caller; | |
2874 | ||
2875 | objnr = obj_to_index(cachep, slabp, objp); | |
2876 | ||
2877 | BUG_ON(objnr >= cachep->num); | |
2878 | BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); | |
2879 | ||
2880 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
2881 | slab_bufctl(slabp)[objnr] = BUFCTL_FREE; | |
2882 | #endif | |
2883 | if (cachep->flags & SLAB_POISON) { | |
2884 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
2885 | if ((cachep->buffer_size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { | |
2886 | store_stackinfo(cachep, objp, (unsigned long)caller); | |
2887 | kernel_map_pages(virt_to_page(objp), | |
2888 | cachep->buffer_size / PAGE_SIZE, 0); | |
2889 | } else { | |
2890 | poison_obj(cachep, objp, POISON_FREE); | |
2891 | } | |
2892 | #else | |
2893 | poison_obj(cachep, objp, POISON_FREE); | |
2894 | #endif | |
2895 | } | |
2896 | return objp; | |
2897 | } | |
2898 | ||
2899 | static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) | |
2900 | { | |
2901 | kmem_bufctl_t i; | |
2902 | int entries = 0; | |
2903 | ||
2904 | /* Check slab's freelist to see if this obj is there. */ | |
2905 | for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { | |
2906 | entries++; | |
2907 | if (entries > cachep->num || i >= cachep->num) | |
2908 | goto bad; | |
2909 | } | |
2910 | if (entries != cachep->num - slabp->inuse) { | |
2911 | bad: | |
2912 | printk(KERN_ERR "slab: Internal list corruption detected in " | |
2913 | "cache '%s'(%d), slabp %p(%d). Hexdump:\n", | |
2914 | cachep->name, cachep->num, slabp, slabp->inuse); | |
2915 | for (i = 0; | |
2916 | i < sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t); | |
2917 | i++) { | |
2918 | if (i % 16 == 0) | |
2919 | printk("\n%03x:", i); | |
2920 | printk(" %02x", ((unsigned char *)slabp)[i]); | |
2921 | } | |
2922 | printk("\n"); | |
2923 | BUG(); | |
2924 | } | |
2925 | } | |
2926 | #else | |
2927 | #define kfree_debugcheck(x) do { } while(0) | |
2928 | #define cache_free_debugcheck(x,objp,z) (objp) | |
2929 | #define check_slabp(x,y) do { } while(0) | |
2930 | #endif | |
2931 | ||
2932 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) | |
2933 | { | |
2934 | int batchcount; | |
2935 | struct kmem_list3 *l3; | |
2936 | struct array_cache *ac; | |
2937 | int node; | |
2938 | ||
2939 | node = numa_node_id(); | |
2940 | ||
2941 | check_irq_off(); | |
2942 | ac = cpu_cache_get(cachep); | |
2943 | retry: | |
2944 | batchcount = ac->batchcount; | |
2945 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { | |
2946 | /* | |
2947 | * If there was little recent activity on this cache, then | |
2948 | * perform only a partial refill. Otherwise we could generate | |
2949 | * refill bouncing. | |
2950 | */ | |
2951 | batchcount = BATCHREFILL_LIMIT; | |
2952 | } | |
2953 | l3 = cachep->nodelists[node]; | |
2954 | ||
2955 | BUG_ON(ac->avail > 0 || !l3); | |
2956 | spin_lock(&l3->list_lock); | |
2957 | ||
2958 | /* See if we can refill from the shared array */ | |
2959 | if (l3->shared && transfer_objects(ac, l3->shared, batchcount)) | |
2960 | goto alloc_done; | |
2961 | ||
2962 | while (batchcount > 0) { | |
2963 | struct list_head *entry; | |
2964 | struct slab *slabp; | |
2965 | /* Get slab alloc is to come from. */ | |
2966 | entry = l3->slabs_partial.next; | |
2967 | if (entry == &l3->slabs_partial) { | |
2968 | l3->free_touched = 1; | |
2969 | entry = l3->slabs_free.next; | |
2970 | if (entry == &l3->slabs_free) | |
2971 | goto must_grow; | |
2972 | } | |
2973 | ||
2974 | slabp = list_entry(entry, struct slab, list); | |
2975 | check_slabp(cachep, slabp); | |
2976 | check_spinlock_acquired(cachep); | |
2977 | ||
2978 | /* | |
2979 | * The slab was either on partial or free list so | |
2980 | * there must be at least one object available for | |
2981 | * allocation. | |
2982 | */ | |
2983 | BUG_ON(slabp->inuse < 0 || slabp->inuse >= cachep->num); | |
2984 | ||
2985 | while (slabp->inuse < cachep->num && batchcount--) { | |
2986 | STATS_INC_ALLOCED(cachep); | |
2987 | STATS_INC_ACTIVE(cachep); | |
2988 | STATS_SET_HIGH(cachep); | |
2989 | ||
2990 | ac->entry[ac->avail++] = slab_get_obj(cachep, slabp, | |
2991 | node); | |
2992 | } | |
2993 | check_slabp(cachep, slabp); | |
2994 | ||
2995 | /* move slabp to correct slabp list: */ | |
2996 | list_del(&slabp->list); | |
2997 | if (slabp->free == BUFCTL_END) | |
2998 | list_add(&slabp->list, &l3->slabs_full); | |
2999 | else | |
3000 | list_add(&slabp->list, &l3->slabs_partial); | |
3001 | } | |
3002 | ||
3003 | must_grow: | |
3004 | l3->free_objects -= ac->avail; | |
3005 | alloc_done: | |
3006 | spin_unlock(&l3->list_lock); | |
3007 | ||
3008 | if (unlikely(!ac->avail)) { | |
3009 | int x; | |
3010 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); | |
3011 | ||
3012 | /* cache_grow can reenable interrupts, then ac could change. */ | |
3013 | ac = cpu_cache_get(cachep); | |
3014 | if (!x && ac->avail == 0) /* no objects in sight? abort */ | |
3015 | return NULL; | |
3016 | ||
3017 | if (!ac->avail) /* objects refilled by interrupt? */ | |
3018 | goto retry; | |
3019 | } | |
3020 | ac->touched = 1; | |
3021 | return ac->entry[--ac->avail]; | |
3022 | } | |
3023 | ||
3024 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, | |
3025 | gfp_t flags) | |
3026 | { | |
3027 | might_sleep_if(flags & __GFP_WAIT); | |
3028 | #if DEBUG | |
3029 | kmem_flagcheck(cachep, flags); | |
3030 | #endif | |
3031 | } | |
3032 | ||
3033 | #if DEBUG | |
3034 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, | |
3035 | gfp_t flags, void *objp, void *caller) | |
3036 | { | |
3037 | if (!objp) | |
3038 | return objp; | |
3039 | if (cachep->flags & SLAB_POISON) { | |
3040 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
3041 | if ((cachep->buffer_size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) | |
3042 | kernel_map_pages(virt_to_page(objp), | |
3043 | cachep->buffer_size / PAGE_SIZE, 1); | |
3044 | else | |
3045 | check_poison_obj(cachep, objp); | |
3046 | #else | |
3047 | check_poison_obj(cachep, objp); | |
3048 | #endif | |
3049 | poison_obj(cachep, objp, POISON_INUSE); | |
3050 | } | |
3051 | if (cachep->flags & SLAB_STORE_USER) | |
3052 | *dbg_userword(cachep, objp) = caller; | |
3053 | ||
3054 | if (cachep->flags & SLAB_RED_ZONE) { | |
3055 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || | |
3056 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { | |
3057 | slab_error(cachep, "double free, or memory outside" | |
3058 | " object was overwritten"); | |
3059 | printk(KERN_ERR | |
3060 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", | |
3061 | objp, *dbg_redzone1(cachep, objp), | |
3062 | *dbg_redzone2(cachep, objp)); | |
3063 | } | |
3064 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; | |
3065 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; | |
3066 | } | |
3067 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
3068 | { | |
3069 | struct slab *slabp; | |
3070 | unsigned objnr; | |
3071 | ||
3072 | slabp = page_get_slab(virt_to_head_page(objp)); | |
3073 | objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size; | |
3074 | slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; | |
3075 | } | |
3076 | #endif | |
3077 | objp += obj_offset(cachep); | |
3078 | if (cachep->ctor && cachep->flags & SLAB_POISON) | |
3079 | cachep->ctor(objp, cachep, 0); | |
3080 | #if ARCH_SLAB_MINALIGN | |
3081 | if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) { | |
3082 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", | |
3083 | objp, ARCH_SLAB_MINALIGN); | |
3084 | } | |
3085 | #endif | |
3086 | return objp; | |
3087 | } | |
3088 | #else | |
3089 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) | |
3090 | #endif | |
3091 | ||
3092 | #ifdef CONFIG_FAILSLAB | |
3093 | ||
3094 | static struct failslab_attr { | |
3095 | ||
3096 | struct fault_attr attr; | |
3097 | ||
3098 | u32 ignore_gfp_wait; | |
3099 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS | |
3100 | struct dentry *ignore_gfp_wait_file; | |
3101 | #endif | |
3102 | ||
3103 | } failslab = { | |
3104 | .attr = FAULT_ATTR_INITIALIZER, | |
3105 | .ignore_gfp_wait = 1, | |
3106 | }; | |
3107 | ||
3108 | static int __init setup_failslab(char *str) | |
3109 | { | |
3110 | return setup_fault_attr(&failslab.attr, str); | |
3111 | } | |
3112 | __setup("failslab=", setup_failslab); | |
3113 | ||
3114 | static int should_failslab(struct kmem_cache *cachep, gfp_t flags) | |
3115 | { | |
3116 | if (cachep == &cache_cache) | |
3117 | return 0; | |
3118 | if (flags & __GFP_NOFAIL) | |
3119 | return 0; | |
3120 | if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT)) | |
3121 | return 0; | |
3122 | ||
3123 | return should_fail(&failslab.attr, obj_size(cachep)); | |
3124 | } | |
3125 | ||
3126 | #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS | |
3127 | ||
3128 | static int __init failslab_debugfs(void) | |
3129 | { | |
3130 | mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; | |
3131 | struct dentry *dir; | |
3132 | int err; | |
3133 | ||
3134 | err = init_fault_attr_dentries(&failslab.attr, "failslab"); | |
3135 | if (err) | |
3136 | return err; | |
3137 | dir = failslab.attr.dentries.dir; | |
3138 | ||
3139 | failslab.ignore_gfp_wait_file = | |
3140 | debugfs_create_bool("ignore-gfp-wait", mode, dir, | |
3141 | &failslab.ignore_gfp_wait); | |
3142 | ||
3143 | if (!failslab.ignore_gfp_wait_file) { | |
3144 | err = -ENOMEM; | |
3145 | debugfs_remove(failslab.ignore_gfp_wait_file); | |
3146 | cleanup_fault_attr_dentries(&failslab.attr); | |
3147 | } | |
3148 | ||
3149 | return err; | |
3150 | } | |
3151 | ||
3152 | late_initcall(failslab_debugfs); | |
3153 | ||
3154 | #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ | |
3155 | ||
3156 | #else /* CONFIG_FAILSLAB */ | |
3157 | ||
3158 | static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags) | |
3159 | { | |
3160 | return 0; | |
3161 | } | |
3162 | ||
3163 | #endif /* CONFIG_FAILSLAB */ | |
3164 | ||
3165 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3166 | { | |
3167 | void *objp; | |
3168 | struct array_cache *ac; | |
3169 | ||
3170 | check_irq_off(); | |
3171 | ||
3172 | ac = cpu_cache_get(cachep); | |
3173 | if (likely(ac->avail)) { | |
3174 | STATS_INC_ALLOCHIT(cachep); | |
3175 | ac->touched = 1; | |
3176 | objp = ac->entry[--ac->avail]; | |
3177 | } else { | |
3178 | STATS_INC_ALLOCMISS(cachep); | |
3179 | objp = cache_alloc_refill(cachep, flags); | |
3180 | } | |
3181 | return objp; | |
3182 | } | |
3183 | ||
3184 | #ifdef CONFIG_NUMA | |
3185 | /* | |
3186 | * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. | |
3187 | * | |
3188 | * If we are in_interrupt, then process context, including cpusets and | |
3189 | * mempolicy, may not apply and should not be used for allocation policy. | |
3190 | */ | |
3191 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3192 | { | |
3193 | int nid_alloc, nid_here; | |
3194 | ||
3195 | if (in_interrupt() || (flags & __GFP_THISNODE)) | |
3196 | return NULL; | |
3197 | nid_alloc = nid_here = numa_node_id(); | |
3198 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) | |
3199 | nid_alloc = cpuset_mem_spread_node(); | |
3200 | else if (current->mempolicy) | |
3201 | nid_alloc = slab_node(current->mempolicy); | |
3202 | if (nid_alloc != nid_here) | |
3203 | return ____cache_alloc_node(cachep, flags, nid_alloc); | |
3204 | return NULL; | |
3205 | } | |
3206 | ||
3207 | /* | |
3208 | * Fallback function if there was no memory available and no objects on a | |
3209 | * certain node and fall back is permitted. First we scan all the | |
3210 | * available nodelists for available objects. If that fails then we | |
3211 | * perform an allocation without specifying a node. This allows the page | |
3212 | * allocator to do its reclaim / fallback magic. We then insert the | |
3213 | * slab into the proper nodelist and then allocate from it. | |
3214 | */ | |
3215 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) | |
3216 | { | |
3217 | struct zonelist *zonelist; | |
3218 | gfp_t local_flags; | |
3219 | struct zone **z; | |
3220 | void *obj = NULL; | |
3221 | int nid; | |
3222 | ||
3223 | if (flags & __GFP_THISNODE) | |
3224 | return NULL; | |
3225 | ||
3226 | zonelist = &NODE_DATA(slab_node(current->mempolicy)) | |
3227 | ->node_zonelists[gfp_zone(flags)]; | |
3228 | local_flags = (flags & GFP_LEVEL_MASK); | |
3229 | ||
3230 | retry: | |
3231 | /* | |
3232 | * Look through allowed nodes for objects available | |
3233 | * from existing per node queues. | |
3234 | */ | |
3235 | for (z = zonelist->zones; *z && !obj; z++) { | |
3236 | nid = zone_to_nid(*z); | |
3237 | ||
3238 | if (cpuset_zone_allowed_hardwall(*z, flags) && | |
3239 | cache->nodelists[nid] && | |
3240 | cache->nodelists[nid]->free_objects) | |
3241 | obj = ____cache_alloc_node(cache, | |
3242 | flags | GFP_THISNODE, nid); | |
3243 | } | |
3244 | ||
3245 | if (!obj) { | |
3246 | /* | |
3247 | * This allocation will be performed within the constraints | |
3248 | * of the current cpuset / memory policy requirements. | |
3249 | * We may trigger various forms of reclaim on the allowed | |
3250 | * set and go into memory reserves if necessary. | |
3251 | */ | |
3252 | if (local_flags & __GFP_WAIT) | |
3253 | local_irq_enable(); | |
3254 | kmem_flagcheck(cache, flags); | |
3255 | obj = kmem_getpages(cache, flags, -1); | |
3256 | if (local_flags & __GFP_WAIT) | |
3257 | local_irq_disable(); | |
3258 | if (obj) { | |
3259 | /* | |
3260 | * Insert into the appropriate per node queues | |
3261 | */ | |
3262 | nid = page_to_nid(virt_to_page(obj)); | |
3263 | if (cache_grow(cache, flags, nid, obj)) { | |
3264 | obj = ____cache_alloc_node(cache, | |
3265 | flags | GFP_THISNODE, nid); | |
3266 | if (!obj) | |
3267 | /* | |
3268 | * Another processor may allocate the | |
3269 | * objects in the slab since we are | |
3270 | * not holding any locks. | |
3271 | */ | |
3272 | goto retry; | |
3273 | } else { | |
3274 | /* cache_grow already freed obj */ | |
3275 | obj = NULL; | |
3276 | } | |
3277 | } | |
3278 | } | |
3279 | return obj; | |
3280 | } | |
3281 | ||
3282 | /* | |
3283 | * A interface to enable slab creation on nodeid | |
3284 | */ | |
3285 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, | |
3286 | int nodeid) | |
3287 | { | |
3288 | struct list_head *entry; | |
3289 | struct slab *slabp; | |
3290 | struct kmem_list3 *l3; | |
3291 | void *obj; | |
3292 | int x; | |
3293 | ||
3294 | l3 = cachep->nodelists[nodeid]; | |
3295 | BUG_ON(!l3); | |
3296 | ||
3297 | retry: | |
3298 | check_irq_off(); | |
3299 | spin_lock(&l3->list_lock); | |
3300 | entry = l3->slabs_partial.next; | |
3301 | if (entry == &l3->slabs_partial) { | |
3302 | l3->free_touched = 1; | |
3303 | entry = l3->slabs_free.next; | |
3304 | if (entry == &l3->slabs_free) | |
3305 | goto must_grow; | |
3306 | } | |
3307 | ||
3308 | slabp = list_entry(entry, struct slab, list); | |
3309 | check_spinlock_acquired_node(cachep, nodeid); | |
3310 | check_slabp(cachep, slabp); | |
3311 | ||
3312 | STATS_INC_NODEALLOCS(cachep); | |
3313 | STATS_INC_ACTIVE(cachep); | |
3314 | STATS_SET_HIGH(cachep); | |
3315 | ||
3316 | BUG_ON(slabp->inuse == cachep->num); | |
3317 | ||
3318 | obj = slab_get_obj(cachep, slabp, nodeid); | |
3319 | check_slabp(cachep, slabp); | |
3320 | l3->free_objects--; | |
3321 | /* move slabp to correct slabp list: */ | |
3322 | list_del(&slabp->list); | |
3323 | ||
3324 | if (slabp->free == BUFCTL_END) | |
3325 | list_add(&slabp->list, &l3->slabs_full); | |
3326 | else | |
3327 | list_add(&slabp->list, &l3->slabs_partial); | |
3328 | ||
3329 | spin_unlock(&l3->list_lock); | |
3330 | goto done; | |
3331 | ||
3332 | must_grow: | |
3333 | spin_unlock(&l3->list_lock); | |
3334 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); | |
3335 | if (x) | |
3336 | goto retry; | |
3337 | ||
3338 | return fallback_alloc(cachep, flags); | |
3339 | ||
3340 | done: | |
3341 | return obj; | |
3342 | } | |
3343 | ||
3344 | /** | |
3345 | * kmem_cache_alloc_node - Allocate an object on the specified node | |
3346 | * @cachep: The cache to allocate from. | |
3347 | * @flags: See kmalloc(). | |
3348 | * @nodeid: node number of the target node. | |
3349 | * @caller: return address of caller, used for debug information | |
3350 | * | |
3351 | * Identical to kmem_cache_alloc but it will allocate memory on the given | |
3352 | * node, which can improve the performance for cpu bound structures. | |
3353 | * | |
3354 | * Fallback to other node is possible if __GFP_THISNODE is not set. | |
3355 | */ | |
3356 | static __always_inline void * | |
3357 | __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, | |
3358 | void *caller) | |
3359 | { | |
3360 | unsigned long save_flags; | |
3361 | void *ptr; | |
3362 | ||
3363 | if (should_failslab(cachep, flags)) | |
3364 | return NULL; | |
3365 | ||
3366 | cache_alloc_debugcheck_before(cachep, flags); | |
3367 | local_irq_save(save_flags); | |
3368 | ||
3369 | if (unlikely(nodeid == -1)) | |
3370 | nodeid = numa_node_id(); | |
3371 | ||
3372 | if (unlikely(!cachep->nodelists[nodeid])) { | |
3373 | /* Node not bootstrapped yet */ | |
3374 | ptr = fallback_alloc(cachep, flags); | |
3375 | goto out; | |
3376 | } | |
3377 | ||
3378 | if (nodeid == numa_node_id()) { | |
3379 | /* | |
3380 | * Use the locally cached objects if possible. | |
3381 | * However ____cache_alloc does not allow fallback | |
3382 | * to other nodes. It may fail while we still have | |
3383 | * objects on other nodes available. | |
3384 | */ | |
3385 | ptr = ____cache_alloc(cachep, flags); | |
3386 | if (ptr) | |
3387 | goto out; | |
3388 | } | |
3389 | /* ___cache_alloc_node can fall back to other nodes */ | |
3390 | ptr = ____cache_alloc_node(cachep, flags, nodeid); | |
3391 | out: | |
3392 | local_irq_restore(save_flags); | |
3393 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); | |
3394 | ||
3395 | if (unlikely((flags & __GFP_ZERO) && ptr)) | |
3396 | memset(ptr, 0, obj_size(cachep)); | |
3397 | ||
3398 | return ptr; | |
3399 | } | |
3400 | ||
3401 | static __always_inline void * | |
3402 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) | |
3403 | { | |
3404 | void *objp; | |
3405 | ||
3406 | if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { | |
3407 | objp = alternate_node_alloc(cache, flags); | |
3408 | if (objp) | |
3409 | goto out; | |
3410 | } | |
3411 | objp = ____cache_alloc(cache, flags); | |
3412 | ||
3413 | /* | |
3414 | * We may just have run out of memory on the local node. | |
3415 | * ____cache_alloc_node() knows how to locate memory on other nodes | |
3416 | */ | |
3417 | if (!objp) | |
3418 | objp = ____cache_alloc_node(cache, flags, numa_node_id()); | |
3419 | ||
3420 | out: | |
3421 | return objp; | |
3422 | } | |
3423 | #else | |
3424 | ||
3425 | static __always_inline void * | |
3426 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3427 | { | |
3428 | return ____cache_alloc(cachep, flags); | |
3429 | } | |
3430 | ||
3431 | #endif /* CONFIG_NUMA */ | |
3432 | ||
3433 | static __always_inline void * | |
3434 | __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) | |
3435 | { | |
3436 | unsigned long save_flags; | |
3437 | void *objp; | |
3438 | ||
3439 | if (should_failslab(cachep, flags)) | |
3440 | return NULL; | |
3441 | ||
3442 | cache_alloc_debugcheck_before(cachep, flags); | |
3443 | local_irq_save(save_flags); | |
3444 | objp = __do_cache_alloc(cachep, flags); | |
3445 | local_irq_restore(save_flags); | |
3446 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); | |
3447 | prefetchw(objp); | |
3448 | ||
3449 | if (unlikely((flags & __GFP_ZERO) && objp)) | |
3450 | memset(objp, 0, obj_size(cachep)); | |
3451 | ||
3452 | return objp; | |
3453 | } | |
3454 | ||
3455 | /* | |
3456 | * Caller needs to acquire correct kmem_list's list_lock | |
3457 | */ | |
3458 | static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, | |
3459 | int node) | |
3460 | { | |
3461 | int i; | |
3462 | struct kmem_list3 *l3; | |
3463 | ||
3464 | for (i = 0; i < nr_objects; i++) { | |
3465 | void *objp = objpp[i]; | |
3466 | struct slab *slabp; | |
3467 | ||
3468 | slabp = virt_to_slab(objp); | |
3469 | l3 = cachep->nodelists[node]; | |
3470 | list_del(&slabp->list); | |
3471 | check_spinlock_acquired_node(cachep, node); | |
3472 | check_slabp(cachep, slabp); | |
3473 | slab_put_obj(cachep, slabp, objp, node); | |
3474 | STATS_DEC_ACTIVE(cachep); | |
3475 | l3->free_objects++; | |
3476 | check_slabp(cachep, slabp); | |
3477 | ||
3478 | /* fixup slab chains */ | |
3479 | if (slabp->inuse == 0) { | |
3480 | if (l3->free_objects > l3->free_limit) { | |
3481 | l3->free_objects -= cachep->num; | |
3482 | /* No need to drop any previously held | |
3483 | * lock here, even if we have a off-slab slab | |
3484 | * descriptor it is guaranteed to come from | |
3485 | * a different cache, refer to comments before | |
3486 | * alloc_slabmgmt. | |
3487 | */ | |
3488 | slab_destroy(cachep, slabp); | |
3489 | } else { | |
3490 | list_add(&slabp->list, &l3->slabs_free); | |
3491 | } | |
3492 | } else { | |
3493 | /* Unconditionally move a slab to the end of the | |
3494 | * partial list on free - maximum time for the | |
3495 | * other objects to be freed, too. | |
3496 | */ | |
3497 | list_add_tail(&slabp->list, &l3->slabs_partial); | |
3498 | } | |
3499 | } | |
3500 | } | |
3501 | ||
3502 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) | |
3503 | { | |
3504 | int batchcount; | |
3505 | struct kmem_list3 *l3; | |
3506 | int node = numa_node_id(); | |
3507 | ||
3508 | batchcount = ac->batchcount; | |
3509 | #if DEBUG | |
3510 | BUG_ON(!batchcount || batchcount > ac->avail); | |
3511 | #endif | |
3512 | check_irq_off(); | |
3513 | l3 = cachep->nodelists[node]; | |
3514 | spin_lock(&l3->list_lock); | |
3515 | if (l3->shared) { | |
3516 | struct array_cache *shared_array = l3->shared; | |
3517 | int max = shared_array->limit - shared_array->avail; | |
3518 | if (max) { | |
3519 | if (batchcount > max) | |
3520 | batchcount = max; | |
3521 | memcpy(&(shared_array->entry[shared_array->avail]), | |
3522 | ac->entry, sizeof(void *) * batchcount); | |
3523 | shared_array->avail += batchcount; | |
3524 | goto free_done; | |
3525 | } | |
3526 | } | |
3527 | ||
3528 | free_block(cachep, ac->entry, batchcount, node); | |
3529 | free_done: | |
3530 | #if STATS | |
3531 | { | |
3532 | int i = 0; | |
3533 | struct list_head *p; | |
3534 | ||
3535 | p = l3->slabs_free.next; | |
3536 | while (p != &(l3->slabs_free)) { | |
3537 | struct slab *slabp; | |
3538 | ||
3539 | slabp = list_entry(p, struct slab, list); | |
3540 | BUG_ON(slabp->inuse); | |
3541 | ||
3542 | i++; | |
3543 | p = p->next; | |
3544 | } | |
3545 | STATS_SET_FREEABLE(cachep, i); | |
3546 | } | |
3547 | #endif | |
3548 | spin_unlock(&l3->list_lock); | |
3549 | ac->avail -= batchcount; | |
3550 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); | |
3551 | } | |
3552 | ||
3553 | /* | |
3554 | * Release an obj back to its cache. If the obj has a constructed state, it must | |
3555 | * be in this state _before_ it is released. Called with disabled ints. | |
3556 | */ | |
3557 | static inline void __cache_free(struct kmem_cache *cachep, void *objp) | |
3558 | { | |
3559 | struct array_cache *ac = cpu_cache_get(cachep); | |
3560 | ||
3561 | check_irq_off(); | |
3562 | objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); | |
3563 | ||
3564 | if (cache_free_alien(cachep, objp)) | |
3565 | return; | |
3566 | ||
3567 | if (likely(ac->avail < ac->limit)) { | |
3568 | STATS_INC_FREEHIT(cachep); | |
3569 | ac->entry[ac->avail++] = objp; | |
3570 | return; | |
3571 | } else { | |
3572 | STATS_INC_FREEMISS(cachep); | |
3573 | cache_flusharray(cachep, ac); | |
3574 | ac->entry[ac->avail++] = objp; | |
3575 | } | |
3576 | } | |
3577 | ||
3578 | /** | |
3579 | * kmem_cache_alloc - Allocate an object | |
3580 | * @cachep: The cache to allocate from. | |
3581 | * @flags: See kmalloc(). | |
3582 | * | |
3583 | * Allocate an object from this cache. The flags are only relevant | |
3584 | * if the cache has no available objects. | |
3585 | */ | |
3586 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3587 | { | |
3588 | return __cache_alloc(cachep, flags, __builtin_return_address(0)); | |
3589 | } | |
3590 | EXPORT_SYMBOL(kmem_cache_alloc); | |
3591 | ||
3592 | /** | |
3593 | * kmem_ptr_validate - check if an untrusted pointer might | |
3594 | * be a slab entry. | |
3595 | * @cachep: the cache we're checking against | |
3596 | * @ptr: pointer to validate | |
3597 | * | |
3598 | * This verifies that the untrusted pointer looks sane: | |
3599 | * it is _not_ a guarantee that the pointer is actually | |
3600 | * part of the slab cache in question, but it at least | |
3601 | * validates that the pointer can be dereferenced and | |
3602 | * looks half-way sane. | |
3603 | * | |
3604 | * Currently only used for dentry validation. | |
3605 | */ | |
3606 | int kmem_ptr_validate(struct kmem_cache *cachep, const void *ptr) | |
3607 | { | |
3608 | unsigned long addr = (unsigned long)ptr; | |
3609 | unsigned long min_addr = PAGE_OFFSET; | |
3610 | unsigned long align_mask = BYTES_PER_WORD - 1; | |
3611 | unsigned long size = cachep->buffer_size; | |
3612 | struct page *page; | |
3613 | ||
3614 | if (unlikely(addr < min_addr)) | |
3615 | goto out; | |
3616 | if (unlikely(addr > (unsigned long)high_memory - size)) | |
3617 | goto out; | |
3618 | if (unlikely(addr & align_mask)) | |
3619 | goto out; | |
3620 | if (unlikely(!kern_addr_valid(addr))) | |
3621 | goto out; | |
3622 | if (unlikely(!kern_addr_valid(addr + size - 1))) | |
3623 | goto out; | |
3624 | page = virt_to_page(ptr); | |
3625 | if (unlikely(!PageSlab(page))) | |
3626 | goto out; | |
3627 | if (unlikely(page_get_cache(page) != cachep)) | |
3628 | goto out; | |
3629 | return 1; | |
3630 | out: | |
3631 | return 0; | |
3632 | } | |
3633 | ||
3634 | #ifdef CONFIG_NUMA | |
3635 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) | |
3636 | { | |
3637 | return __cache_alloc_node(cachep, flags, nodeid, | |
3638 | __builtin_return_address(0)); | |
3639 | } | |
3640 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
3641 | ||
3642 | static __always_inline void * | |
3643 | __do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller) | |
3644 | { | |
3645 | struct kmem_cache *cachep; | |
3646 | ||
3647 | cachep = kmem_find_general_cachep(size, flags); | |
3648 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) | |
3649 | return cachep; | |
3650 | return kmem_cache_alloc_node(cachep, flags, node); | |
3651 | } | |
3652 | ||
3653 | #ifdef CONFIG_DEBUG_SLAB | |
3654 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
3655 | { | |
3656 | return __do_kmalloc_node(size, flags, node, | |
3657 | __builtin_return_address(0)); | |
3658 | } | |
3659 | EXPORT_SYMBOL(__kmalloc_node); | |
3660 | ||
3661 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, | |
3662 | int node, void *caller) | |
3663 | { | |
3664 | return __do_kmalloc_node(size, flags, node, caller); | |
3665 | } | |
3666 | EXPORT_SYMBOL(__kmalloc_node_track_caller); | |
3667 | #else | |
3668 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
3669 | { | |
3670 | return __do_kmalloc_node(size, flags, node, NULL); | |
3671 | } | |
3672 | EXPORT_SYMBOL(__kmalloc_node); | |
3673 | #endif /* CONFIG_DEBUG_SLAB */ | |
3674 | #endif /* CONFIG_NUMA */ | |
3675 | ||
3676 | /** | |
3677 | * __do_kmalloc - allocate memory | |
3678 | * @size: how many bytes of memory are required. | |
3679 | * @flags: the type of memory to allocate (see kmalloc). | |
3680 | * @caller: function caller for debug tracking of the caller | |
3681 | */ | |
3682 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, | |
3683 | void *caller) | |
3684 | { | |
3685 | struct kmem_cache *cachep; | |
3686 | ||
3687 | /* If you want to save a few bytes .text space: replace | |
3688 | * __ with kmem_. | |
3689 | * Then kmalloc uses the uninlined functions instead of the inline | |
3690 | * functions. | |
3691 | */ | |
3692 | cachep = __find_general_cachep(size, flags); | |
3693 | if (unlikely(cachep == NULL)) | |
3694 | return NULL; | |
3695 | return __cache_alloc(cachep, flags, caller); | |
3696 | } | |
3697 | ||
3698 | ||
3699 | #ifdef CONFIG_DEBUG_SLAB | |
3700 | void *__kmalloc(size_t size, gfp_t flags) | |
3701 | { | |
3702 | return __do_kmalloc(size, flags, __builtin_return_address(0)); | |
3703 | } | |
3704 | EXPORT_SYMBOL(__kmalloc); | |
3705 | ||
3706 | void *__kmalloc_track_caller(size_t size, gfp_t flags, void *caller) | |
3707 | { | |
3708 | return __do_kmalloc(size, flags, caller); | |
3709 | } | |
3710 | EXPORT_SYMBOL(__kmalloc_track_caller); | |
3711 | ||
3712 | #else | |
3713 | void *__kmalloc(size_t size, gfp_t flags) | |
3714 | { | |
3715 | return __do_kmalloc(size, flags, NULL); | |
3716 | } | |
3717 | EXPORT_SYMBOL(__kmalloc); | |
3718 | #endif | |
3719 | ||
3720 | /** | |
3721 | * kmem_cache_free - Deallocate an object | |
3722 | * @cachep: The cache the allocation was from. | |
3723 | * @objp: The previously allocated object. | |
3724 | * | |
3725 | * Free an object which was previously allocated from this | |
3726 | * cache. | |
3727 | */ | |
3728 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) | |
3729 | { | |
3730 | unsigned long flags; | |
3731 | ||
3732 | BUG_ON(virt_to_cache(objp) != cachep); | |
3733 | ||
3734 | local_irq_save(flags); | |
3735 | debug_check_no_locks_freed(objp, obj_size(cachep)); | |
3736 | __cache_free(cachep, objp); | |
3737 | local_irq_restore(flags); | |
3738 | } | |
3739 | EXPORT_SYMBOL(kmem_cache_free); | |
3740 | ||
3741 | /** | |
3742 | * kfree - free previously allocated memory | |
3743 | * @objp: pointer returned by kmalloc. | |
3744 | * | |
3745 | * If @objp is NULL, no operation is performed. | |
3746 | * | |
3747 | * Don't free memory not originally allocated by kmalloc() | |
3748 | * or you will run into trouble. | |
3749 | */ | |
3750 | void kfree(const void *objp) | |
3751 | { | |
3752 | struct kmem_cache *c; | |
3753 | unsigned long flags; | |
3754 | ||
3755 | if (unlikely(ZERO_OR_NULL_PTR(objp))) | |
3756 | return; | |
3757 | local_irq_save(flags); | |
3758 | kfree_debugcheck(objp); | |
3759 | c = virt_to_cache(objp); | |
3760 | debug_check_no_locks_freed(objp, obj_size(c)); | |
3761 | __cache_free(c, (void *)objp); | |
3762 | local_irq_restore(flags); | |
3763 | } | |
3764 | EXPORT_SYMBOL(kfree); | |
3765 | ||
3766 | unsigned int kmem_cache_size(struct kmem_cache *cachep) | |
3767 | { | |
3768 | return obj_size(cachep); | |
3769 | } | |
3770 | EXPORT_SYMBOL(kmem_cache_size); | |
3771 | ||
3772 | const char *kmem_cache_name(struct kmem_cache *cachep) | |
3773 | { | |
3774 | return cachep->name; | |
3775 | } | |
3776 | EXPORT_SYMBOL_GPL(kmem_cache_name); | |
3777 | ||
3778 | /* | |
3779 | * This initializes kmem_list3 or resizes varioius caches for all nodes. | |
3780 | */ | |
3781 | static int alloc_kmemlist(struct kmem_cache *cachep) | |
3782 | { | |
3783 | int node; | |
3784 | struct kmem_list3 *l3; | |
3785 | struct array_cache *new_shared; | |
3786 | struct array_cache **new_alien = NULL; | |
3787 | ||
3788 | for_each_online_node(node) { | |
3789 | ||
3790 | if (use_alien_caches) { | |
3791 | new_alien = alloc_alien_cache(node, cachep->limit); | |
3792 | if (!new_alien) | |
3793 | goto fail; | |
3794 | } | |
3795 | ||
3796 | new_shared = NULL; | |
3797 | if (cachep->shared) { | |
3798 | new_shared = alloc_arraycache(node, | |
3799 | cachep->shared*cachep->batchcount, | |
3800 | 0xbaadf00d); | |
3801 | if (!new_shared) { | |
3802 | free_alien_cache(new_alien); | |
3803 | goto fail; | |
3804 | } | |
3805 | } | |
3806 | ||
3807 | l3 = cachep->nodelists[node]; | |
3808 | if (l3) { | |
3809 | struct array_cache *shared = l3->shared; | |
3810 | ||
3811 | spin_lock_irq(&l3->list_lock); | |
3812 | ||
3813 | if (shared) | |
3814 | free_block(cachep, shared->entry, | |
3815 | shared->avail, node); | |
3816 | ||
3817 | l3->shared = new_shared; | |
3818 | if (!l3->alien) { | |
3819 | l3->alien = new_alien; | |
3820 | new_alien = NULL; | |
3821 | } | |
3822 | l3->free_limit = (1 + nr_cpus_node(node)) * | |
3823 | cachep->batchcount + cachep->num; | |
3824 | spin_unlock_irq(&l3->list_lock); | |
3825 | kfree(shared); | |
3826 | free_alien_cache(new_alien); | |
3827 | continue; | |
3828 | } | |
3829 | l3 = kmalloc_node(sizeof(struct kmem_list3), GFP_KERNEL, node); | |
3830 | if (!l3) { | |
3831 | free_alien_cache(new_alien); | |
3832 | kfree(new_shared); | |
3833 | goto fail; | |
3834 | } | |
3835 | ||
3836 | kmem_list3_init(l3); | |
3837 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + | |
3838 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
3839 | l3->shared = new_shared; | |
3840 | l3->alien = new_alien; | |
3841 | l3->free_limit = (1 + nr_cpus_node(node)) * | |
3842 | cachep->batchcount + cachep->num; | |
3843 | cachep->nodelists[node] = l3; | |
3844 | } | |
3845 | return 0; | |
3846 | ||
3847 | fail: | |
3848 | if (!cachep->next.next) { | |
3849 | /* Cache is not active yet. Roll back what we did */ | |
3850 | node--; | |
3851 | while (node >= 0) { | |
3852 | if (cachep->nodelists[node]) { | |
3853 | l3 = cachep->nodelists[node]; | |
3854 | ||
3855 | kfree(l3->shared); | |
3856 | free_alien_cache(l3->alien); | |
3857 | kfree(l3); | |
3858 | cachep->nodelists[node] = NULL; | |
3859 | } | |
3860 | node--; | |
3861 | } | |
3862 | } | |
3863 | return -ENOMEM; | |
3864 | } | |
3865 | ||
3866 | struct ccupdate_struct { | |
3867 | struct kmem_cache *cachep; | |
3868 | struct array_cache *new[NR_CPUS]; | |
3869 | }; | |
3870 | ||
3871 | static void do_ccupdate_local(void *info) | |
3872 | { | |
3873 | struct ccupdate_struct *new = info; | |
3874 | struct array_cache *old; | |
3875 | ||
3876 | check_irq_off(); | |
3877 | old = cpu_cache_get(new->cachep); | |
3878 | ||
3879 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; | |
3880 | new->new[smp_processor_id()] = old; | |
3881 | } | |
3882 | ||
3883 | /* Always called with the cache_chain_mutex held */ | |
3884 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, | |
3885 | int batchcount, int shared) | |
3886 | { | |
3887 | struct ccupdate_struct *new; | |
3888 | int i; | |
3889 | ||
3890 | new = kzalloc(sizeof(*new), GFP_KERNEL); | |
3891 | if (!new) | |
3892 | return -ENOMEM; | |
3893 | ||
3894 | for_each_online_cpu(i) { | |
3895 | new->new[i] = alloc_arraycache(cpu_to_node(i), limit, | |
3896 | batchcount); | |
3897 | if (!new->new[i]) { | |
3898 | for (i--; i >= 0; i--) | |
3899 | kfree(new->new[i]); | |
3900 | kfree(new); | |
3901 | return -ENOMEM; | |
3902 | } | |
3903 | } | |
3904 | new->cachep = cachep; | |
3905 | ||
3906 | on_each_cpu(do_ccupdate_local, (void *)new, 1, 1); | |
3907 | ||
3908 | check_irq_on(); | |
3909 | cachep->batchcount = batchcount; | |
3910 | cachep->limit = limit; | |
3911 | cachep->shared = shared; | |
3912 | ||
3913 | for_each_online_cpu(i) { | |
3914 | struct array_cache *ccold = new->new[i]; | |
3915 | if (!ccold) | |
3916 | continue; | |
3917 | spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); | |
3918 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_node(i)); | |
3919 | spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock); | |
3920 | kfree(ccold); | |
3921 | } | |
3922 | kfree(new); | |
3923 | return alloc_kmemlist(cachep); | |
3924 | } | |
3925 | ||
3926 | /* Called with cache_chain_mutex held always */ | |
3927 | static int enable_cpucache(struct kmem_cache *cachep) | |
3928 | { | |
3929 | int err; | |
3930 | int limit, shared; | |
3931 | ||
3932 | /* | |
3933 | * The head array serves three purposes: | |
3934 | * - create a LIFO ordering, i.e. return objects that are cache-warm | |
3935 | * - reduce the number of spinlock operations. | |
3936 | * - reduce the number of linked list operations on the slab and | |
3937 | * bufctl chains: array operations are cheaper. | |
3938 | * The numbers are guessed, we should auto-tune as described by | |
3939 | * Bonwick. | |
3940 | */ | |
3941 | if (cachep->buffer_size > 131072) | |
3942 | limit = 1; | |
3943 | else if (cachep->buffer_size > PAGE_SIZE) | |
3944 | limit = 8; | |
3945 | else if (cachep->buffer_size > 1024) | |
3946 | limit = 24; | |
3947 | else if (cachep->buffer_size > 256) | |
3948 | limit = 54; | |
3949 | else | |
3950 | limit = 120; | |
3951 | ||
3952 | /* | |
3953 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound | |
3954 | * allocation behaviour: Most allocs on one cpu, most free operations | |
3955 | * on another cpu. For these cases, an efficient object passing between | |
3956 | * cpus is necessary. This is provided by a shared array. The array | |
3957 | * replaces Bonwick's magazine layer. | |
3958 | * On uniprocessor, it's functionally equivalent (but less efficient) | |
3959 | * to a larger limit. Thus disabled by default. | |
3960 | */ | |
3961 | shared = 0; | |
3962 | if (cachep->buffer_size <= PAGE_SIZE && num_possible_cpus() > 1) | |
3963 | shared = 8; | |
3964 | ||
3965 | #if DEBUG | |
3966 | /* | |
3967 | * With debugging enabled, large batchcount lead to excessively long | |
3968 | * periods with disabled local interrupts. Limit the batchcount | |
3969 | */ | |
3970 | if (limit > 32) | |
3971 | limit = 32; | |
3972 | #endif | |
3973 | err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared); | |
3974 | if (err) | |
3975 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", | |
3976 | cachep->name, -err); | |
3977 | return err; | |
3978 | } | |
3979 | ||
3980 | /* | |
3981 | * Drain an array if it contains any elements taking the l3 lock only if | |
3982 | * necessary. Note that the l3 listlock also protects the array_cache | |
3983 | * if drain_array() is used on the shared array. | |
3984 | */ | |
3985 | void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, | |
3986 | struct array_cache *ac, int force, int node) | |
3987 | { | |
3988 | int tofree; | |
3989 | ||
3990 | if (!ac || !ac->avail) | |
3991 | return; | |
3992 | if (ac->touched && !force) { | |
3993 | ac->touched = 0; | |
3994 | } else { | |
3995 | spin_lock_irq(&l3->list_lock); | |
3996 | if (ac->avail) { | |
3997 | tofree = force ? ac->avail : (ac->limit + 4) / 5; | |
3998 | if (tofree > ac->avail) | |
3999 | tofree = (ac->avail + 1) / 2; | |
4000 | free_block(cachep, ac->entry, tofree, node); | |
4001 | ac->avail -= tofree; | |
4002 | memmove(ac->entry, &(ac->entry[tofree]), | |
4003 | sizeof(void *) * ac->avail); | |
4004 | } | |
4005 | spin_unlock_irq(&l3->list_lock); | |
4006 | } | |
4007 | } | |
4008 | ||
4009 | /** | |
4010 | * cache_reap - Reclaim memory from caches. | |
4011 | * @w: work descriptor | |
4012 | * | |
4013 | * Called from workqueue/eventd every few seconds. | |
4014 | * Purpose: | |
4015 | * - clear the per-cpu caches for this CPU. | |
4016 | * - return freeable pages to the main free memory pool. | |
4017 | * | |
4018 | * If we cannot acquire the cache chain mutex then just give up - we'll try | |
4019 | * again on the next iteration. | |
4020 | */ | |
4021 | static void cache_reap(struct work_struct *w) | |
4022 | { | |
4023 | struct kmem_cache *searchp; | |
4024 | struct kmem_list3 *l3; | |
4025 | int node = numa_node_id(); | |
4026 | struct delayed_work *work = | |
4027 | container_of(w, struct delayed_work, work); | |
4028 | ||
4029 | if (!mutex_trylock(&cache_chain_mutex)) | |
4030 | /* Give up. Setup the next iteration. */ | |
4031 | goto out; | |
4032 | ||
4033 | list_for_each_entry(searchp, &cache_chain, next) { | |
4034 | check_irq_on(); | |
4035 | ||
4036 | /* | |
4037 | * We only take the l3 lock if absolutely necessary and we | |
4038 | * have established with reasonable certainty that | |
4039 | * we can do some work if the lock was obtained. | |
4040 | */ | |
4041 | l3 = searchp->nodelists[node]; | |
4042 | ||
4043 | reap_alien(searchp, l3); | |
4044 | ||
4045 | drain_array(searchp, l3, cpu_cache_get(searchp), 0, node); | |
4046 | ||
4047 | /* | |
4048 | * These are racy checks but it does not matter | |
4049 | * if we skip one check or scan twice. | |
4050 | */ | |
4051 | if (time_after(l3->next_reap, jiffies)) | |
4052 | goto next; | |
4053 | ||
4054 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3; | |
4055 | ||
4056 | drain_array(searchp, l3, l3->shared, 0, node); | |
4057 | ||
4058 | if (l3->free_touched) | |
4059 | l3->free_touched = 0; | |
4060 | else { | |
4061 | int freed; | |
4062 | ||
4063 | freed = drain_freelist(searchp, l3, (l3->free_limit + | |
4064 | 5 * searchp->num - 1) / (5 * searchp->num)); | |
4065 | STATS_ADD_REAPED(searchp, freed); | |
4066 | } | |
4067 | next: | |
4068 | cond_resched(); | |
4069 | } | |
4070 | check_irq_on(); | |
4071 | mutex_unlock(&cache_chain_mutex); | |
4072 | next_reap_node(); | |
4073 | out: | |
4074 | /* Set up the next iteration */ | |
4075 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); | |
4076 | } | |
4077 | ||
4078 | #ifdef CONFIG_PROC_FS | |
4079 | ||
4080 | static void print_slabinfo_header(struct seq_file *m) | |
4081 | { | |
4082 | /* | |
4083 | * Output format version, so at least we can change it | |
4084 | * without _too_ many complaints. | |
4085 | */ | |
4086 | #if STATS | |
4087 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
4088 | #else | |
4089 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
4090 | #endif | |
4091 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " | |
4092 | "<objperslab> <pagesperslab>"); | |
4093 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); | |
4094 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
4095 | #if STATS | |
4096 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " | |
4097 | "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); | |
4098 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); | |
4099 | #endif | |
4100 | seq_putc(m, '\n'); | |
4101 | } | |
4102 | ||
4103 | static void *s_start(struct seq_file *m, loff_t *pos) | |
4104 | { | |
4105 | loff_t n = *pos; | |
4106 | ||
4107 | mutex_lock(&cache_chain_mutex); | |
4108 | if (!n) | |
4109 | print_slabinfo_header(m); | |
4110 | ||
4111 | return seq_list_start(&cache_chain, *pos); | |
4112 | } | |
4113 | ||
4114 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
4115 | { | |
4116 | return seq_list_next(p, &cache_chain, pos); | |
4117 | } | |
4118 | ||
4119 | static void s_stop(struct seq_file *m, void *p) | |
4120 | { | |
4121 | mutex_unlock(&cache_chain_mutex); | |
4122 | } | |
4123 | ||
4124 | static int s_show(struct seq_file *m, void *p) | |
4125 | { | |
4126 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next); | |
4127 | struct slab *slabp; | |
4128 | unsigned long active_objs; | |
4129 | unsigned long num_objs; | |
4130 | unsigned long active_slabs = 0; | |
4131 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; | |
4132 | const char *name; | |
4133 | char *error = NULL; | |
4134 | int node; | |
4135 | struct kmem_list3 *l3; | |
4136 | ||
4137 | active_objs = 0; | |
4138 | num_slabs = 0; | |
4139 | for_each_online_node(node) { | |
4140 | l3 = cachep->nodelists[node]; | |
4141 | if (!l3) | |
4142 | continue; | |
4143 | ||
4144 | check_irq_on(); | |
4145 | spin_lock_irq(&l3->list_lock); | |
4146 | ||
4147 | list_for_each_entry(slabp, &l3->slabs_full, list) { | |
4148 | if (slabp->inuse != cachep->num && !error) | |
4149 | error = "slabs_full accounting error"; | |
4150 | active_objs += cachep->num; | |
4151 | active_slabs++; | |
4152 | } | |
4153 | list_for_each_entry(slabp, &l3->slabs_partial, list) { | |
4154 | if (slabp->inuse == cachep->num && !error) | |
4155 | error = "slabs_partial inuse accounting error"; | |
4156 | if (!slabp->inuse && !error) | |
4157 | error = "slabs_partial/inuse accounting error"; | |
4158 | active_objs += slabp->inuse; | |
4159 | active_slabs++; | |
4160 | } | |
4161 | list_for_each_entry(slabp, &l3->slabs_free, list) { | |
4162 | if (slabp->inuse && !error) | |
4163 | error = "slabs_free/inuse accounting error"; | |
4164 | num_slabs++; | |
4165 | } | |
4166 | free_objects += l3->free_objects; | |
4167 | if (l3->shared) | |
4168 | shared_avail += l3->shared->avail; | |
4169 | ||
4170 | spin_unlock_irq(&l3->list_lock); | |
4171 | } | |
4172 | num_slabs += active_slabs; | |
4173 | num_objs = num_slabs * cachep->num; | |
4174 | if (num_objs - active_objs != free_objects && !error) | |
4175 | error = "free_objects accounting error"; | |
4176 | ||
4177 | name = cachep->name; | |
4178 | if (error) | |
4179 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); | |
4180 | ||
4181 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", | |
4182 | name, active_objs, num_objs, cachep->buffer_size, | |
4183 | cachep->num, (1 << cachep->gfporder)); | |
4184 | seq_printf(m, " : tunables %4u %4u %4u", | |
4185 | cachep->limit, cachep->batchcount, cachep->shared); | |
4186 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
4187 | active_slabs, num_slabs, shared_avail); | |
4188 | #if STATS | |
4189 | { /* list3 stats */ | |
4190 | unsigned long high = cachep->high_mark; | |
4191 | unsigned long allocs = cachep->num_allocations; | |
4192 | unsigned long grown = cachep->grown; | |
4193 | unsigned long reaped = cachep->reaped; | |
4194 | unsigned long errors = cachep->errors; | |
4195 | unsigned long max_freeable = cachep->max_freeable; | |
4196 | unsigned long node_allocs = cachep->node_allocs; | |
4197 | unsigned long node_frees = cachep->node_frees; | |
4198 | unsigned long overflows = cachep->node_overflow; | |
4199 | ||
4200 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \ | |
4201 | %4lu %4lu %4lu %4lu %4lu", allocs, high, grown, | |
4202 | reaped, errors, max_freeable, node_allocs, | |
4203 | node_frees, overflows); | |
4204 | } | |
4205 | /* cpu stats */ | |
4206 | { | |
4207 | unsigned long allochit = atomic_read(&cachep->allochit); | |
4208 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); | |
4209 | unsigned long freehit = atomic_read(&cachep->freehit); | |
4210 | unsigned long freemiss = atomic_read(&cachep->freemiss); | |
4211 | ||
4212 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", | |
4213 | allochit, allocmiss, freehit, freemiss); | |
4214 | } | |
4215 | #endif | |
4216 | seq_putc(m, '\n'); | |
4217 | return 0; | |
4218 | } | |
4219 | ||
4220 | /* | |
4221 | * slabinfo_op - iterator that generates /proc/slabinfo | |
4222 | * | |
4223 | * Output layout: | |
4224 | * cache-name | |
4225 | * num-active-objs | |
4226 | * total-objs | |
4227 | * object size | |
4228 | * num-active-slabs | |
4229 | * total-slabs | |
4230 | * num-pages-per-slab | |
4231 | * + further values on SMP and with statistics enabled | |
4232 | */ | |
4233 | ||
4234 | const struct seq_operations slabinfo_op = { | |
4235 | .start = s_start, | |
4236 | .next = s_next, | |
4237 | .stop = s_stop, | |
4238 | .show = s_show, | |
4239 | }; | |
4240 | ||
4241 | #define MAX_SLABINFO_WRITE 128 | |
4242 | /** | |
4243 | * slabinfo_write - Tuning for the slab allocator | |
4244 | * @file: unused | |
4245 | * @buffer: user buffer | |
4246 | * @count: data length | |
4247 | * @ppos: unused | |
4248 | */ | |
4249 | ssize_t slabinfo_write(struct file *file, const char __user * buffer, | |
4250 | size_t count, loff_t *ppos) | |
4251 | { | |
4252 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; | |
4253 | int limit, batchcount, shared, res; | |
4254 | struct kmem_cache *cachep; | |
4255 | ||
4256 | if (count > MAX_SLABINFO_WRITE) | |
4257 | return -EINVAL; | |
4258 | if (copy_from_user(&kbuf, buffer, count)) | |
4259 | return -EFAULT; | |
4260 | kbuf[MAX_SLABINFO_WRITE] = '\0'; | |
4261 | ||
4262 | tmp = strchr(kbuf, ' '); | |
4263 | if (!tmp) | |
4264 | return -EINVAL; | |
4265 | *tmp = '\0'; | |
4266 | tmp++; | |
4267 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) | |
4268 | return -EINVAL; | |
4269 | ||
4270 | /* Find the cache in the chain of caches. */ | |
4271 | mutex_lock(&cache_chain_mutex); | |
4272 | res = -EINVAL; | |
4273 | list_for_each_entry(cachep, &cache_chain, next) { | |
4274 | if (!strcmp(cachep->name, kbuf)) { | |
4275 | if (limit < 1 || batchcount < 1 || | |
4276 | batchcount > limit || shared < 0) { | |
4277 | res = 0; | |
4278 | } else { | |
4279 | res = do_tune_cpucache(cachep, limit, | |
4280 | batchcount, shared); | |
4281 | } | |
4282 | break; | |
4283 | } | |
4284 | } | |
4285 | mutex_unlock(&cache_chain_mutex); | |
4286 | if (res >= 0) | |
4287 | res = count; | |
4288 | return res; | |
4289 | } | |
4290 | ||
4291 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
4292 | ||
4293 | static void *leaks_start(struct seq_file *m, loff_t *pos) | |
4294 | { | |
4295 | mutex_lock(&cache_chain_mutex); | |
4296 | return seq_list_start(&cache_chain, *pos); | |
4297 | } | |
4298 | ||
4299 | static inline int add_caller(unsigned long *n, unsigned long v) | |
4300 | { | |
4301 | unsigned long *p; | |
4302 | int l; | |
4303 | if (!v) | |
4304 | return 1; | |
4305 | l = n[1]; | |
4306 | p = n + 2; | |
4307 | while (l) { | |
4308 | int i = l/2; | |
4309 | unsigned long *q = p + 2 * i; | |
4310 | if (*q == v) { | |
4311 | q[1]++; | |
4312 | return 1; | |
4313 | } | |
4314 | if (*q > v) { | |
4315 | l = i; | |
4316 | } else { | |
4317 | p = q + 2; | |
4318 | l -= i + 1; | |
4319 | } | |
4320 | } | |
4321 | if (++n[1] == n[0]) | |
4322 | return 0; | |
4323 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); | |
4324 | p[0] = v; | |
4325 | p[1] = 1; | |
4326 | return 1; | |
4327 | } | |
4328 | ||
4329 | static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s) | |
4330 | { | |
4331 | void *p; | |
4332 | int i; | |
4333 | if (n[0] == n[1]) | |
4334 | return; | |
4335 | for (i = 0, p = s->s_mem; i < c->num; i++, p += c->buffer_size) { | |
4336 | if (slab_bufctl(s)[i] != BUFCTL_ACTIVE) | |
4337 | continue; | |
4338 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) | |
4339 | return; | |
4340 | } | |
4341 | } | |
4342 | ||
4343 | static void show_symbol(struct seq_file *m, unsigned long address) | |
4344 | { | |
4345 | #ifdef CONFIG_KALLSYMS | |
4346 | unsigned long offset, size; | |
4347 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; | |
4348 | ||
4349 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { | |
4350 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); | |
4351 | if (modname[0]) | |
4352 | seq_printf(m, " [%s]", modname); | |
4353 | return; | |
4354 | } | |
4355 | #endif | |
4356 | seq_printf(m, "%p", (void *)address); | |
4357 | } | |
4358 | ||
4359 | static int leaks_show(struct seq_file *m, void *p) | |
4360 | { | |
4361 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, next); | |
4362 | struct slab *slabp; | |
4363 | struct kmem_list3 *l3; | |
4364 | const char *name; | |
4365 | unsigned long *n = m->private; | |
4366 | int node; | |
4367 | int i; | |
4368 | ||
4369 | if (!(cachep->flags & SLAB_STORE_USER)) | |
4370 | return 0; | |
4371 | if (!(cachep->flags & SLAB_RED_ZONE)) | |
4372 | return 0; | |
4373 | ||
4374 | /* OK, we can do it */ | |
4375 | ||
4376 | n[1] = 0; | |
4377 | ||
4378 | for_each_online_node(node) { | |
4379 | l3 = cachep->nodelists[node]; | |
4380 | if (!l3) | |
4381 | continue; | |
4382 | ||
4383 | check_irq_on(); | |
4384 | spin_lock_irq(&l3->list_lock); | |
4385 | ||
4386 | list_for_each_entry(slabp, &l3->slabs_full, list) | |
4387 | handle_slab(n, cachep, slabp); | |
4388 | list_for_each_entry(slabp, &l3->slabs_partial, list) | |
4389 | handle_slab(n, cachep, slabp); | |
4390 | spin_unlock_irq(&l3->list_lock); | |
4391 | } | |
4392 | name = cachep->name; | |
4393 | if (n[0] == n[1]) { | |
4394 | /* Increase the buffer size */ | |
4395 | mutex_unlock(&cache_chain_mutex); | |
4396 | m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL); | |
4397 | if (!m->private) { | |
4398 | /* Too bad, we are really out */ | |
4399 | m->private = n; | |
4400 | mutex_lock(&cache_chain_mutex); | |
4401 | return -ENOMEM; | |
4402 | } | |
4403 | *(unsigned long *)m->private = n[0] * 2; | |
4404 | kfree(n); | |
4405 | mutex_lock(&cache_chain_mutex); | |
4406 | /* Now make sure this entry will be retried */ | |
4407 | m->count = m->size; | |
4408 | return 0; | |
4409 | } | |
4410 | for (i = 0; i < n[1]; i++) { | |
4411 | seq_printf(m, "%s: %lu ", name, n[2*i+3]); | |
4412 | show_symbol(m, n[2*i+2]); | |
4413 | seq_putc(m, '\n'); | |
4414 | } | |
4415 | ||
4416 | return 0; | |
4417 | } | |
4418 | ||
4419 | const struct seq_operations slabstats_op = { | |
4420 | .start = leaks_start, | |
4421 | .next = s_next, | |
4422 | .stop = s_stop, | |
4423 | .show = leaks_show, | |
4424 | }; | |
4425 | #endif | |
4426 | #endif | |
4427 | ||
4428 | /** | |
4429 | * ksize - get the actual amount of memory allocated for a given object | |
4430 | * @objp: Pointer to the object | |
4431 | * | |
4432 | * kmalloc may internally round up allocations and return more memory | |
4433 | * than requested. ksize() can be used to determine the actual amount of | |
4434 | * memory allocated. The caller may use this additional memory, even though | |
4435 | * a smaller amount of memory was initially specified with the kmalloc call. | |
4436 | * The caller must guarantee that objp points to a valid object previously | |
4437 | * allocated with either kmalloc() or kmem_cache_alloc(). The object | |
4438 | * must not be freed during the duration of the call. | |
4439 | */ | |
4440 | size_t ksize(const void *objp) | |
4441 | { | |
4442 | if (unlikely(ZERO_OR_NULL_PTR(objp))) | |
4443 | return 0; | |
4444 | ||
4445 | return obj_size(virt_to_cache(objp)); | |
4446 | } |