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1 | /* | |
2 | * linux/mm/slab.c | |
3 | * Written by Mark Hemment, 1996/97. | |
4 | * (markhe@nextd.demon.co.uk) | |
5 | * | |
6 | * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli | |
7 | * | |
8 | * Major cleanup, different bufctl logic, per-cpu arrays | |
9 | * (c) 2000 Manfred Spraul | |
10 | * | |
11 | * Cleanup, make the head arrays unconditional, preparation for NUMA | |
12 | * (c) 2002 Manfred Spraul | |
13 | * | |
14 | * An implementation of the Slab Allocator as described in outline in; | |
15 | * UNIX Internals: The New Frontiers by Uresh Vahalia | |
16 | * Pub: Prentice Hall ISBN 0-13-101908-2 | |
17 | * or with a little more detail in; | |
18 | * The Slab Allocator: An Object-Caching Kernel Memory Allocator | |
19 | * Jeff Bonwick (Sun Microsystems). | |
20 | * Presented at: USENIX Summer 1994 Technical Conference | |
21 | * | |
22 | * The memory is organized in caches, one cache for each object type. | |
23 | * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) | |
24 | * Each cache consists out of many slabs (they are small (usually one | |
25 | * page long) and always contiguous), and each slab contains multiple | |
26 | * initialized objects. | |
27 | * | |
28 | * This means, that your constructor is used only for newly allocated | |
29 | * slabs and you must pass objects with the same initializations to | |
30 | * kmem_cache_free. | |
31 | * | |
32 | * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM, | |
33 | * normal). If you need a special memory type, then must create a new | |
34 | * cache for that memory type. | |
35 | * | |
36 | * In order to reduce fragmentation, the slabs are sorted in 3 groups: | |
37 | * full slabs with 0 free objects | |
38 | * partial slabs | |
39 | * empty slabs with no allocated objects | |
40 | * | |
41 | * If partial slabs exist, then new allocations come from these slabs, | |
42 | * otherwise from empty slabs or new slabs are allocated. | |
43 | * | |
44 | * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache | |
45 | * during kmem_cache_destroy(). The caller must prevent concurrent allocs. | |
46 | * | |
47 | * Each cache has a short per-cpu head array, most allocs | |
48 | * and frees go into that array, and if that array overflows, then 1/2 | |
49 | * of the entries in the array are given back into the global cache. | |
50 | * The head array is strictly LIFO and should improve the cache hit rates. | |
51 | * On SMP, it additionally reduces the spinlock operations. | |
52 | * | |
53 | * The c_cpuarray may not be read with enabled local interrupts - | |
54 | * it's changed with a smp_call_function(). | |
55 | * | |
56 | * SMP synchronization: | |
57 | * constructors and destructors are called without any locking. | |
58 | * Several members in struct kmem_cache and struct slab never change, they | |
59 | * are accessed without any locking. | |
60 | * The per-cpu arrays are never accessed from the wrong cpu, no locking, | |
61 | * and local interrupts are disabled so slab code is preempt-safe. | |
62 | * The non-constant members are protected with a per-cache irq spinlock. | |
63 | * | |
64 | * Many thanks to Mark Hemment, who wrote another per-cpu slab patch | |
65 | * in 2000 - many ideas in the current implementation are derived from | |
66 | * his patch. | |
67 | * | |
68 | * Further notes from the original documentation: | |
69 | * | |
70 | * 11 April '97. Started multi-threading - markhe | |
71 | * The global cache-chain is protected by the mutex 'slab_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 "slab.h" | |
91 | #include <linux/mm.h> | |
92 | #include <linux/poison.h> | |
93 | #include <linux/swap.h> | |
94 | #include <linux/cache.h> | |
95 | #include <linux/interrupt.h> | |
96 | #include <linux/init.h> | |
97 | #include <linux/compiler.h> | |
98 | #include <linux/cpuset.h> | |
99 | #include <linux/proc_fs.h> | |
100 | #include <linux/seq_file.h> | |
101 | #include <linux/notifier.h> | |
102 | #include <linux/kallsyms.h> | |
103 | #include <linux/cpu.h> | |
104 | #include <linux/sysctl.h> | |
105 | #include <linux/module.h> | |
106 | #include <linux/rcupdate.h> | |
107 | #include <linux/string.h> | |
108 | #include <linux/uaccess.h> | |
109 | #include <linux/nodemask.h> | |
110 | #include <linux/kmemleak.h> | |
111 | #include <linux/mempolicy.h> | |
112 | #include <linux/mutex.h> | |
113 | #include <linux/fault-inject.h> | |
114 | #include <linux/rtmutex.h> | |
115 | #include <linux/reciprocal_div.h> | |
116 | #include <linux/debugobjects.h> | |
117 | #include <linux/kmemcheck.h> | |
118 | #include <linux/memory.h> | |
119 | #include <linux/prefetch.h> | |
120 | ||
121 | #include <net/sock.h> | |
122 | ||
123 | #include <asm/cacheflush.h> | |
124 | #include <asm/tlbflush.h> | |
125 | #include <asm/page.h> | |
126 | ||
127 | #include <trace/events/kmem.h> | |
128 | ||
129 | #include "internal.h" | |
130 | ||
131 | /* | |
132 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. | |
133 | * 0 for faster, smaller code (especially in the critical paths). | |
134 | * | |
135 | * STATS - 1 to collect stats for /proc/slabinfo. | |
136 | * 0 for faster, smaller code (especially in the critical paths). | |
137 | * | |
138 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) | |
139 | */ | |
140 | ||
141 | #ifdef CONFIG_DEBUG_SLAB | |
142 | #define DEBUG 1 | |
143 | #define STATS 1 | |
144 | #define FORCED_DEBUG 1 | |
145 | #else | |
146 | #define DEBUG 0 | |
147 | #define STATS 0 | |
148 | #define FORCED_DEBUG 0 | |
149 | #endif | |
150 | ||
151 | /* Shouldn't this be in a header file somewhere? */ | |
152 | #define BYTES_PER_WORD sizeof(void *) | |
153 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) | |
154 | ||
155 | #ifndef ARCH_KMALLOC_FLAGS | |
156 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN | |
157 | #endif | |
158 | ||
159 | /* | |
160 | * true if a page was allocated from pfmemalloc reserves for network-based | |
161 | * swap | |
162 | */ | |
163 | static bool pfmemalloc_active __read_mostly; | |
164 | ||
165 | /* Legal flag mask for kmem_cache_create(). */ | |
166 | #if DEBUG | |
167 | # define CREATE_MASK (SLAB_RED_ZONE | \ | |
168 | SLAB_POISON | SLAB_HWCACHE_ALIGN | \ | |
169 | SLAB_CACHE_DMA | \ | |
170 | SLAB_STORE_USER | \ | |
171 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | |
172 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ | |
173 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) | |
174 | #else | |
175 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ | |
176 | SLAB_CACHE_DMA | \ | |
177 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | |
178 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ | |
179 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE | SLAB_NOTRACK) | |
180 | #endif | |
181 | ||
182 | /* | |
183 | * kmem_bufctl_t: | |
184 | * | |
185 | * Bufctl's are used for linking objs within a slab | |
186 | * linked offsets. | |
187 | * | |
188 | * This implementation relies on "struct page" for locating the cache & | |
189 | * slab an object belongs to. | |
190 | * This allows the bufctl structure to be small (one int), but limits | |
191 | * the number of objects a slab (not a cache) can contain when off-slab | |
192 | * bufctls are used. The limit is the size of the largest general cache | |
193 | * that does not use off-slab slabs. | |
194 | * For 32bit archs with 4 kB pages, is this 56. | |
195 | * This is not serious, as it is only for large objects, when it is unwise | |
196 | * to have too many per slab. | |
197 | * Note: This limit can be raised by introducing a general cache whose size | |
198 | * is less than 512 (PAGE_SIZE<<3), but greater than 256. | |
199 | */ | |
200 | ||
201 | typedef unsigned int kmem_bufctl_t; | |
202 | #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) | |
203 | #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) | |
204 | #define BUFCTL_ACTIVE (((kmem_bufctl_t)(~0U))-2) | |
205 | #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) | |
206 | ||
207 | /* | |
208 | * struct slab_rcu | |
209 | * | |
210 | * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to | |
211 | * arrange for kmem_freepages to be called via RCU. This is useful if | |
212 | * we need to approach a kernel structure obliquely, from its address | |
213 | * obtained without the usual locking. We can lock the structure to | |
214 | * stabilize it and check it's still at the given address, only if we | |
215 | * can be sure that the memory has not been meanwhile reused for some | |
216 | * other kind of object (which our subsystem's lock might corrupt). | |
217 | * | |
218 | * rcu_read_lock before reading the address, then rcu_read_unlock after | |
219 | * taking the spinlock within the structure expected at that address. | |
220 | */ | |
221 | struct slab_rcu { | |
222 | struct rcu_head head; | |
223 | struct kmem_cache *cachep; | |
224 | void *addr; | |
225 | }; | |
226 | ||
227 | /* | |
228 | * struct slab | |
229 | * | |
230 | * Manages the objs in a slab. Placed either at the beginning of mem allocated | |
231 | * for a slab, or allocated from an general cache. | |
232 | * Slabs are chained into three list: fully used, partial, fully free slabs. | |
233 | */ | |
234 | struct slab { | |
235 | union { | |
236 | struct { | |
237 | struct list_head list; | |
238 | unsigned long colouroff; | |
239 | void *s_mem; /* including colour offset */ | |
240 | unsigned int inuse; /* num of objs active in slab */ | |
241 | kmem_bufctl_t free; | |
242 | unsigned short nodeid; | |
243 | }; | |
244 | struct slab_rcu __slab_cover_slab_rcu; | |
245 | }; | |
246 | }; | |
247 | ||
248 | /* | |
249 | * struct array_cache | |
250 | * | |
251 | * Purpose: | |
252 | * - LIFO ordering, to hand out cache-warm objects from _alloc | |
253 | * - reduce the number of linked list operations | |
254 | * - reduce spinlock operations | |
255 | * | |
256 | * The limit is stored in the per-cpu structure to reduce the data cache | |
257 | * footprint. | |
258 | * | |
259 | */ | |
260 | struct array_cache { | |
261 | unsigned int avail; | |
262 | unsigned int limit; | |
263 | unsigned int batchcount; | |
264 | unsigned int touched; | |
265 | spinlock_t lock; | |
266 | void *entry[]; /* | |
267 | * Must have this definition in here for the proper | |
268 | * alignment of array_cache. Also simplifies accessing | |
269 | * the entries. | |
270 | * | |
271 | * Entries should not be directly dereferenced as | |
272 | * entries belonging to slabs marked pfmemalloc will | |
273 | * have the lower bits set SLAB_OBJ_PFMEMALLOC | |
274 | */ | |
275 | }; | |
276 | ||
277 | #define SLAB_OBJ_PFMEMALLOC 1 | |
278 | static inline bool is_obj_pfmemalloc(void *objp) | |
279 | { | |
280 | return (unsigned long)objp & SLAB_OBJ_PFMEMALLOC; | |
281 | } | |
282 | ||
283 | static inline void set_obj_pfmemalloc(void **objp) | |
284 | { | |
285 | *objp = (void *)((unsigned long)*objp | SLAB_OBJ_PFMEMALLOC); | |
286 | return; | |
287 | } | |
288 | ||
289 | static inline void clear_obj_pfmemalloc(void **objp) | |
290 | { | |
291 | *objp = (void *)((unsigned long)*objp & ~SLAB_OBJ_PFMEMALLOC); | |
292 | } | |
293 | ||
294 | /* | |
295 | * bootstrap: The caches do not work without cpuarrays anymore, but the | |
296 | * cpuarrays are allocated from the generic caches... | |
297 | */ | |
298 | #define BOOT_CPUCACHE_ENTRIES 1 | |
299 | struct arraycache_init { | |
300 | struct array_cache cache; | |
301 | void *entries[BOOT_CPUCACHE_ENTRIES]; | |
302 | }; | |
303 | ||
304 | /* | |
305 | * The slab lists for all objects. | |
306 | */ | |
307 | struct kmem_list3 { | |
308 | struct list_head slabs_partial; /* partial list first, better asm code */ | |
309 | struct list_head slabs_full; | |
310 | struct list_head slabs_free; | |
311 | unsigned long free_objects; | |
312 | unsigned int free_limit; | |
313 | unsigned int colour_next; /* Per-node cache coloring */ | |
314 | spinlock_t list_lock; | |
315 | struct array_cache *shared; /* shared per node */ | |
316 | struct array_cache **alien; /* on other nodes */ | |
317 | unsigned long next_reap; /* updated without locking */ | |
318 | int free_touched; /* updated without locking */ | |
319 | }; | |
320 | ||
321 | /* | |
322 | * Need this for bootstrapping a per node allocator. | |
323 | */ | |
324 | #define NUM_INIT_LISTS (3 * MAX_NUMNODES) | |
325 | static struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS]; | |
326 | #define CACHE_CACHE 0 | |
327 | #define SIZE_AC MAX_NUMNODES | |
328 | #define SIZE_L3 (2 * MAX_NUMNODES) | |
329 | ||
330 | static int drain_freelist(struct kmem_cache *cache, | |
331 | struct kmem_list3 *l3, int tofree); | |
332 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, | |
333 | int node); | |
334 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); | |
335 | static void cache_reap(struct work_struct *unused); | |
336 | ||
337 | /* | |
338 | * This function must be completely optimized away if a constant is passed to | |
339 | * it. Mostly the same as what is in linux/slab.h except it returns an index. | |
340 | */ | |
341 | static __always_inline int index_of(const size_t size) | |
342 | { | |
343 | extern void __bad_size(void); | |
344 | ||
345 | if (__builtin_constant_p(size)) { | |
346 | int i = 0; | |
347 | ||
348 | #define CACHE(x) \ | |
349 | if (size <=x) \ | |
350 | return i; \ | |
351 | else \ | |
352 | i++; | |
353 | #include <linux/kmalloc_sizes.h> | |
354 | #undef CACHE | |
355 | __bad_size(); | |
356 | } else | |
357 | __bad_size(); | |
358 | return 0; | |
359 | } | |
360 | ||
361 | static int slab_early_init = 1; | |
362 | ||
363 | #define INDEX_AC index_of(sizeof(struct arraycache_init)) | |
364 | #define INDEX_L3 index_of(sizeof(struct kmem_list3)) | |
365 | ||
366 | static void kmem_list3_init(struct kmem_list3 *parent) | |
367 | { | |
368 | INIT_LIST_HEAD(&parent->slabs_full); | |
369 | INIT_LIST_HEAD(&parent->slabs_partial); | |
370 | INIT_LIST_HEAD(&parent->slabs_free); | |
371 | parent->shared = NULL; | |
372 | parent->alien = NULL; | |
373 | parent->colour_next = 0; | |
374 | spin_lock_init(&parent->list_lock); | |
375 | parent->free_objects = 0; | |
376 | parent->free_touched = 0; | |
377 | } | |
378 | ||
379 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ | |
380 | do { \ | |
381 | INIT_LIST_HEAD(listp); \ | |
382 | list_splice(&(cachep->nodelists[nodeid]->slab), listp); \ | |
383 | } while (0) | |
384 | ||
385 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ | |
386 | do { \ | |
387 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ | |
388 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ | |
389 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ | |
390 | } while (0) | |
391 | ||
392 | #define CFLGS_OFF_SLAB (0x80000000UL) | |
393 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) | |
394 | ||
395 | #define BATCHREFILL_LIMIT 16 | |
396 | /* | |
397 | * Optimization question: fewer reaps means less probability for unnessary | |
398 | * cpucache drain/refill cycles. | |
399 | * | |
400 | * OTOH the cpuarrays can contain lots of objects, | |
401 | * which could lock up otherwise freeable slabs. | |
402 | */ | |
403 | #define REAPTIMEOUT_CPUC (2*HZ) | |
404 | #define REAPTIMEOUT_LIST3 (4*HZ) | |
405 | ||
406 | #if STATS | |
407 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) | |
408 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) | |
409 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) | |
410 | #define STATS_INC_GROWN(x) ((x)->grown++) | |
411 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) | |
412 | #define STATS_SET_HIGH(x) \ | |
413 | do { \ | |
414 | if ((x)->num_active > (x)->high_mark) \ | |
415 | (x)->high_mark = (x)->num_active; \ | |
416 | } while (0) | |
417 | #define STATS_INC_ERR(x) ((x)->errors++) | |
418 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) | |
419 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) | |
420 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) | |
421 | #define STATS_SET_FREEABLE(x, i) \ | |
422 | do { \ | |
423 | if ((x)->max_freeable < i) \ | |
424 | (x)->max_freeable = i; \ | |
425 | } while (0) | |
426 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) | |
427 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) | |
428 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) | |
429 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) | |
430 | #else | |
431 | #define STATS_INC_ACTIVE(x) do { } while (0) | |
432 | #define STATS_DEC_ACTIVE(x) do { } while (0) | |
433 | #define STATS_INC_ALLOCED(x) do { } while (0) | |
434 | #define STATS_INC_GROWN(x) do { } while (0) | |
435 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) | |
436 | #define STATS_SET_HIGH(x) do { } while (0) | |
437 | #define STATS_INC_ERR(x) do { } while (0) | |
438 | #define STATS_INC_NODEALLOCS(x) do { } while (0) | |
439 | #define STATS_INC_NODEFREES(x) do { } while (0) | |
440 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) | |
441 | #define STATS_SET_FREEABLE(x, i) do { } while (0) | |
442 | #define STATS_INC_ALLOCHIT(x) do { } while (0) | |
443 | #define STATS_INC_ALLOCMISS(x) do { } while (0) | |
444 | #define STATS_INC_FREEHIT(x) do { } while (0) | |
445 | #define STATS_INC_FREEMISS(x) do { } while (0) | |
446 | #endif | |
447 | ||
448 | #if DEBUG | |
449 | ||
450 | /* | |
451 | * memory layout of objects: | |
452 | * 0 : objp | |
453 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that | |
454 | * the end of an object is aligned with the end of the real | |
455 | * allocation. Catches writes behind the end of the allocation. | |
456 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: | |
457 | * redzone word. | |
458 | * cachep->obj_offset: The real object. | |
459 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] | |
460 | * cachep->size - 1* BYTES_PER_WORD: last caller address | |
461 | * [BYTES_PER_WORD long] | |
462 | */ | |
463 | static int obj_offset(struct kmem_cache *cachep) | |
464 | { | |
465 | return cachep->obj_offset; | |
466 | } | |
467 | ||
468 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) | |
469 | { | |
470 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
471 | return (unsigned long long*) (objp + obj_offset(cachep) - | |
472 | sizeof(unsigned long long)); | |
473 | } | |
474 | ||
475 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) | |
476 | { | |
477 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
478 | if (cachep->flags & SLAB_STORE_USER) | |
479 | return (unsigned long long *)(objp + cachep->size - | |
480 | sizeof(unsigned long long) - | |
481 | REDZONE_ALIGN); | |
482 | return (unsigned long long *) (objp + cachep->size - | |
483 | sizeof(unsigned long long)); | |
484 | } | |
485 | ||
486 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) | |
487 | { | |
488 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); | |
489 | return (void **)(objp + cachep->size - BYTES_PER_WORD); | |
490 | } | |
491 | ||
492 | #else | |
493 | ||
494 | #define obj_offset(x) 0 | |
495 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
496 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
497 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) | |
498 | ||
499 | #endif | |
500 | ||
501 | /* | |
502 | * Do not go above this order unless 0 objects fit into the slab or | |
503 | * overridden on the command line. | |
504 | */ | |
505 | #define SLAB_MAX_ORDER_HI 1 | |
506 | #define SLAB_MAX_ORDER_LO 0 | |
507 | static int slab_max_order = SLAB_MAX_ORDER_LO; | |
508 | static bool slab_max_order_set __initdata; | |
509 | ||
510 | static inline struct kmem_cache *virt_to_cache(const void *obj) | |
511 | { | |
512 | struct page *page = virt_to_head_page(obj); | |
513 | return page->slab_cache; | |
514 | } | |
515 | ||
516 | static inline struct slab *virt_to_slab(const void *obj) | |
517 | { | |
518 | struct page *page = virt_to_head_page(obj); | |
519 | ||
520 | VM_BUG_ON(!PageSlab(page)); | |
521 | return page->slab_page; | |
522 | } | |
523 | ||
524 | static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, | |
525 | unsigned int idx) | |
526 | { | |
527 | return slab->s_mem + cache->size * idx; | |
528 | } | |
529 | ||
530 | /* | |
531 | * We want to avoid an expensive divide : (offset / cache->size) | |
532 | * Using the fact that size is a constant for a particular cache, | |
533 | * we can replace (offset / cache->size) by | |
534 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) | |
535 | */ | |
536 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, | |
537 | const struct slab *slab, void *obj) | |
538 | { | |
539 | u32 offset = (obj - slab->s_mem); | |
540 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); | |
541 | } | |
542 | ||
543 | /* | |
544 | * These are the default caches for kmalloc. Custom caches can have other sizes. | |
545 | */ | |
546 | struct cache_sizes malloc_sizes[] = { | |
547 | #define CACHE(x) { .cs_size = (x) }, | |
548 | #include <linux/kmalloc_sizes.h> | |
549 | CACHE(ULONG_MAX) | |
550 | #undef CACHE | |
551 | }; | |
552 | EXPORT_SYMBOL(malloc_sizes); | |
553 | ||
554 | /* Must match cache_sizes above. Out of line to keep cache footprint low. */ | |
555 | struct cache_names { | |
556 | char *name; | |
557 | char *name_dma; | |
558 | }; | |
559 | ||
560 | static struct cache_names __initdata cache_names[] = { | |
561 | #define CACHE(x) { .name = "size-" #x, .name_dma = "size-" #x "(DMA)" }, | |
562 | #include <linux/kmalloc_sizes.h> | |
563 | {NULL,} | |
564 | #undef CACHE | |
565 | }; | |
566 | ||
567 | static struct arraycache_init initarray_cache __initdata = | |
568 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; | |
569 | static struct arraycache_init initarray_generic = | |
570 | { {0, BOOT_CPUCACHE_ENTRIES, 1, 0} }; | |
571 | ||
572 | /* internal cache of cache description objs */ | |
573 | static struct kmem_list3 *cache_cache_nodelists[MAX_NUMNODES]; | |
574 | static struct kmem_cache cache_cache = { | |
575 | .nodelists = cache_cache_nodelists, | |
576 | .batchcount = 1, | |
577 | .limit = BOOT_CPUCACHE_ENTRIES, | |
578 | .shared = 1, | |
579 | .size = sizeof(struct kmem_cache), | |
580 | .name = "kmem_cache", | |
581 | }; | |
582 | ||
583 | #define BAD_ALIEN_MAGIC 0x01020304ul | |
584 | ||
585 | #ifdef CONFIG_LOCKDEP | |
586 | ||
587 | /* | |
588 | * Slab sometimes uses the kmalloc slabs to store the slab headers | |
589 | * for other slabs "off slab". | |
590 | * The locking for this is tricky in that it nests within the locks | |
591 | * of all other slabs in a few places; to deal with this special | |
592 | * locking we put on-slab caches into a separate lock-class. | |
593 | * | |
594 | * We set lock class for alien array caches which are up during init. | |
595 | * The lock annotation will be lost if all cpus of a node goes down and | |
596 | * then comes back up during hotplug | |
597 | */ | |
598 | static struct lock_class_key on_slab_l3_key; | |
599 | static struct lock_class_key on_slab_alc_key; | |
600 | ||
601 | static struct lock_class_key debugobj_l3_key; | |
602 | static struct lock_class_key debugobj_alc_key; | |
603 | ||
604 | static void slab_set_lock_classes(struct kmem_cache *cachep, | |
605 | struct lock_class_key *l3_key, struct lock_class_key *alc_key, | |
606 | int q) | |
607 | { | |
608 | struct array_cache **alc; | |
609 | struct kmem_list3 *l3; | |
610 | int r; | |
611 | ||
612 | l3 = cachep->nodelists[q]; | |
613 | if (!l3) | |
614 | return; | |
615 | ||
616 | lockdep_set_class(&l3->list_lock, l3_key); | |
617 | alc = l3->alien; | |
618 | /* | |
619 | * FIXME: This check for BAD_ALIEN_MAGIC | |
620 | * should go away when common slab code is taught to | |
621 | * work even without alien caches. | |
622 | * Currently, non NUMA code returns BAD_ALIEN_MAGIC | |
623 | * for alloc_alien_cache, | |
624 | */ | |
625 | if (!alc || (unsigned long)alc == BAD_ALIEN_MAGIC) | |
626 | return; | |
627 | for_each_node(r) { | |
628 | if (alc[r]) | |
629 | lockdep_set_class(&alc[r]->lock, alc_key); | |
630 | } | |
631 | } | |
632 | ||
633 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) | |
634 | { | |
635 | slab_set_lock_classes(cachep, &debugobj_l3_key, &debugobj_alc_key, node); | |
636 | } | |
637 | ||
638 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) | |
639 | { | |
640 | int node; | |
641 | ||
642 | for_each_online_node(node) | |
643 | slab_set_debugobj_lock_classes_node(cachep, node); | |
644 | } | |
645 | ||
646 | static void init_node_lock_keys(int q) | |
647 | { | |
648 | struct cache_sizes *s = malloc_sizes; | |
649 | ||
650 | if (slab_state < UP) | |
651 | return; | |
652 | ||
653 | for (s = malloc_sizes; s->cs_size != ULONG_MAX; s++) { | |
654 | struct kmem_list3 *l3; | |
655 | ||
656 | l3 = s->cs_cachep->nodelists[q]; | |
657 | if (!l3 || OFF_SLAB(s->cs_cachep)) | |
658 | continue; | |
659 | ||
660 | slab_set_lock_classes(s->cs_cachep, &on_slab_l3_key, | |
661 | &on_slab_alc_key, q); | |
662 | } | |
663 | } | |
664 | ||
665 | static inline void init_lock_keys(void) | |
666 | { | |
667 | int node; | |
668 | ||
669 | for_each_node(node) | |
670 | init_node_lock_keys(node); | |
671 | } | |
672 | #else | |
673 | static void init_node_lock_keys(int q) | |
674 | { | |
675 | } | |
676 | ||
677 | static inline void init_lock_keys(void) | |
678 | { | |
679 | } | |
680 | ||
681 | static void slab_set_debugobj_lock_classes_node(struct kmem_cache *cachep, int node) | |
682 | { | |
683 | } | |
684 | ||
685 | static void slab_set_debugobj_lock_classes(struct kmem_cache *cachep) | |
686 | { | |
687 | } | |
688 | #endif | |
689 | ||
690 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); | |
691 | ||
692 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) | |
693 | { | |
694 | return cachep->array[smp_processor_id()]; | |
695 | } | |
696 | ||
697 | static inline struct kmem_cache *__find_general_cachep(size_t size, | |
698 | gfp_t gfpflags) | |
699 | { | |
700 | struct cache_sizes *csizep = malloc_sizes; | |
701 | ||
702 | #if DEBUG | |
703 | /* This happens if someone tries to call | |
704 | * kmem_cache_create(), or __kmalloc(), before | |
705 | * the generic caches are initialized. | |
706 | */ | |
707 | BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); | |
708 | #endif | |
709 | if (!size) | |
710 | return ZERO_SIZE_PTR; | |
711 | ||
712 | while (size > csizep->cs_size) | |
713 | csizep++; | |
714 | ||
715 | /* | |
716 | * Really subtle: The last entry with cs->cs_size==ULONG_MAX | |
717 | * has cs_{dma,}cachep==NULL. Thus no special case | |
718 | * for large kmalloc calls required. | |
719 | */ | |
720 | #ifdef CONFIG_ZONE_DMA | |
721 | if (unlikely(gfpflags & GFP_DMA)) | |
722 | return csizep->cs_dmacachep; | |
723 | #endif | |
724 | return csizep->cs_cachep; | |
725 | } | |
726 | ||
727 | static struct kmem_cache *kmem_find_general_cachep(size_t size, gfp_t gfpflags) | |
728 | { | |
729 | return __find_general_cachep(size, gfpflags); | |
730 | } | |
731 | ||
732 | static size_t slab_mgmt_size(size_t nr_objs, size_t align) | |
733 | { | |
734 | return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); | |
735 | } | |
736 | ||
737 | /* | |
738 | * Calculate the number of objects and left-over bytes for a given buffer size. | |
739 | */ | |
740 | static void cache_estimate(unsigned long gfporder, size_t buffer_size, | |
741 | size_t align, int flags, size_t *left_over, | |
742 | unsigned int *num) | |
743 | { | |
744 | int nr_objs; | |
745 | size_t mgmt_size; | |
746 | size_t slab_size = PAGE_SIZE << gfporder; | |
747 | ||
748 | /* | |
749 | * The slab management structure can be either off the slab or | |
750 | * on it. For the latter case, the memory allocated for a | |
751 | * slab is used for: | |
752 | * | |
753 | * - The struct slab | |
754 | * - One kmem_bufctl_t for each object | |
755 | * - Padding to respect alignment of @align | |
756 | * - @buffer_size bytes for each object | |
757 | * | |
758 | * If the slab management structure is off the slab, then the | |
759 | * alignment will already be calculated into the size. Because | |
760 | * the slabs are all pages aligned, the objects will be at the | |
761 | * correct alignment when allocated. | |
762 | */ | |
763 | if (flags & CFLGS_OFF_SLAB) { | |
764 | mgmt_size = 0; | |
765 | nr_objs = slab_size / buffer_size; | |
766 | ||
767 | if (nr_objs > SLAB_LIMIT) | |
768 | nr_objs = SLAB_LIMIT; | |
769 | } else { | |
770 | /* | |
771 | * Ignore padding for the initial guess. The padding | |
772 | * is at most @align-1 bytes, and @buffer_size is at | |
773 | * least @align. In the worst case, this result will | |
774 | * be one greater than the number of objects that fit | |
775 | * into the memory allocation when taking the padding | |
776 | * into account. | |
777 | */ | |
778 | nr_objs = (slab_size - sizeof(struct slab)) / | |
779 | (buffer_size + sizeof(kmem_bufctl_t)); | |
780 | ||
781 | /* | |
782 | * This calculated number will be either the right | |
783 | * amount, or one greater than what we want. | |
784 | */ | |
785 | if (slab_mgmt_size(nr_objs, align) + nr_objs*buffer_size | |
786 | > slab_size) | |
787 | nr_objs--; | |
788 | ||
789 | if (nr_objs > SLAB_LIMIT) | |
790 | nr_objs = SLAB_LIMIT; | |
791 | ||
792 | mgmt_size = slab_mgmt_size(nr_objs, align); | |
793 | } | |
794 | *num = nr_objs; | |
795 | *left_over = slab_size - nr_objs*buffer_size - mgmt_size; | |
796 | } | |
797 | ||
798 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) | |
799 | ||
800 | static void __slab_error(const char *function, struct kmem_cache *cachep, | |
801 | char *msg) | |
802 | { | |
803 | printk(KERN_ERR "slab error in %s(): cache `%s': %s\n", | |
804 | function, cachep->name, msg); | |
805 | dump_stack(); | |
806 | add_taint(TAINT_BAD_PAGE); | |
807 | } | |
808 | ||
809 | /* | |
810 | * By default on NUMA we use alien caches to stage the freeing of | |
811 | * objects allocated from other nodes. This causes massive memory | |
812 | * inefficiencies when using fake NUMA setup to split memory into a | |
813 | * large number of small nodes, so it can be disabled on the command | |
814 | * line | |
815 | */ | |
816 | ||
817 | static int use_alien_caches __read_mostly = 1; | |
818 | static int __init noaliencache_setup(char *s) | |
819 | { | |
820 | use_alien_caches = 0; | |
821 | return 1; | |
822 | } | |
823 | __setup("noaliencache", noaliencache_setup); | |
824 | ||
825 | static int __init slab_max_order_setup(char *str) | |
826 | { | |
827 | get_option(&str, &slab_max_order); | |
828 | slab_max_order = slab_max_order < 0 ? 0 : | |
829 | min(slab_max_order, MAX_ORDER - 1); | |
830 | slab_max_order_set = true; | |
831 | ||
832 | return 1; | |
833 | } | |
834 | __setup("slab_max_order=", slab_max_order_setup); | |
835 | ||
836 | #ifdef CONFIG_NUMA | |
837 | /* | |
838 | * Special reaping functions for NUMA systems called from cache_reap(). | |
839 | * These take care of doing round robin flushing of alien caches (containing | |
840 | * objects freed on different nodes from which they were allocated) and the | |
841 | * flushing of remote pcps by calling drain_node_pages. | |
842 | */ | |
843 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); | |
844 | ||
845 | static void init_reap_node(int cpu) | |
846 | { | |
847 | int node; | |
848 | ||
849 | node = next_node(cpu_to_mem(cpu), node_online_map); | |
850 | if (node == MAX_NUMNODES) | |
851 | node = first_node(node_online_map); | |
852 | ||
853 | per_cpu(slab_reap_node, cpu) = node; | |
854 | } | |
855 | ||
856 | static void next_reap_node(void) | |
857 | { | |
858 | int node = __this_cpu_read(slab_reap_node); | |
859 | ||
860 | node = next_node(node, node_online_map); | |
861 | if (unlikely(node >= MAX_NUMNODES)) | |
862 | node = first_node(node_online_map); | |
863 | __this_cpu_write(slab_reap_node, node); | |
864 | } | |
865 | ||
866 | #else | |
867 | #define init_reap_node(cpu) do { } while (0) | |
868 | #define next_reap_node(void) do { } while (0) | |
869 | #endif | |
870 | ||
871 | /* | |
872 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz | |
873 | * via the workqueue/eventd. | |
874 | * Add the CPU number into the expiration time to minimize the possibility of | |
875 | * the CPUs getting into lockstep and contending for the global cache chain | |
876 | * lock. | |
877 | */ | |
878 | static void __cpuinit start_cpu_timer(int cpu) | |
879 | { | |
880 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); | |
881 | ||
882 | /* | |
883 | * When this gets called from do_initcalls via cpucache_init(), | |
884 | * init_workqueues() has already run, so keventd will be setup | |
885 | * at that time. | |
886 | */ | |
887 | if (keventd_up() && reap_work->work.func == NULL) { | |
888 | init_reap_node(cpu); | |
889 | INIT_DELAYED_WORK_DEFERRABLE(reap_work, cache_reap); | |
890 | schedule_delayed_work_on(cpu, reap_work, | |
891 | __round_jiffies_relative(HZ, cpu)); | |
892 | } | |
893 | } | |
894 | ||
895 | static struct array_cache *alloc_arraycache(int node, int entries, | |
896 | int batchcount, gfp_t gfp) | |
897 | { | |
898 | int memsize = sizeof(void *) * entries + sizeof(struct array_cache); | |
899 | struct array_cache *nc = NULL; | |
900 | ||
901 | nc = kmalloc_node(memsize, gfp, node); | |
902 | /* | |
903 | * The array_cache structures contain pointers to free object. | |
904 | * However, when such objects are allocated or transferred to another | |
905 | * cache the pointers are not cleared and they could be counted as | |
906 | * valid references during a kmemleak scan. Therefore, kmemleak must | |
907 | * not scan such objects. | |
908 | */ | |
909 | kmemleak_no_scan(nc); | |
910 | if (nc) { | |
911 | nc->avail = 0; | |
912 | nc->limit = entries; | |
913 | nc->batchcount = batchcount; | |
914 | nc->touched = 0; | |
915 | spin_lock_init(&nc->lock); | |
916 | } | |
917 | return nc; | |
918 | } | |
919 | ||
920 | static inline bool is_slab_pfmemalloc(struct slab *slabp) | |
921 | { | |
922 | struct page *page = virt_to_page(slabp->s_mem); | |
923 | ||
924 | return PageSlabPfmemalloc(page); | |
925 | } | |
926 | ||
927 | /* Clears pfmemalloc_active if no slabs have pfmalloc set */ | |
928 | static void recheck_pfmemalloc_active(struct kmem_cache *cachep, | |
929 | struct array_cache *ac) | |
930 | { | |
931 | struct kmem_list3 *l3 = cachep->nodelists[numa_mem_id()]; | |
932 | struct slab *slabp; | |
933 | unsigned long flags; | |
934 | ||
935 | if (!pfmemalloc_active) | |
936 | return; | |
937 | ||
938 | spin_lock_irqsave(&l3->list_lock, flags); | |
939 | list_for_each_entry(slabp, &l3->slabs_full, list) | |
940 | if (is_slab_pfmemalloc(slabp)) | |
941 | goto out; | |
942 | ||
943 | list_for_each_entry(slabp, &l3->slabs_partial, list) | |
944 | if (is_slab_pfmemalloc(slabp)) | |
945 | goto out; | |
946 | ||
947 | list_for_each_entry(slabp, &l3->slabs_free, list) | |
948 | if (is_slab_pfmemalloc(slabp)) | |
949 | goto out; | |
950 | ||
951 | pfmemalloc_active = false; | |
952 | out: | |
953 | spin_unlock_irqrestore(&l3->list_lock, flags); | |
954 | } | |
955 | ||
956 | static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac, | |
957 | gfp_t flags, bool force_refill) | |
958 | { | |
959 | int i; | |
960 | void *objp = ac->entry[--ac->avail]; | |
961 | ||
962 | /* Ensure the caller is allowed to use objects from PFMEMALLOC slab */ | |
963 | if (unlikely(is_obj_pfmemalloc(objp))) { | |
964 | struct kmem_list3 *l3; | |
965 | ||
966 | if (gfp_pfmemalloc_allowed(flags)) { | |
967 | clear_obj_pfmemalloc(&objp); | |
968 | return objp; | |
969 | } | |
970 | ||
971 | /* The caller cannot use PFMEMALLOC objects, find another one */ | |
972 | for (i = 1; i < ac->avail; i++) { | |
973 | /* If a !PFMEMALLOC object is found, swap them */ | |
974 | if (!is_obj_pfmemalloc(ac->entry[i])) { | |
975 | objp = ac->entry[i]; | |
976 | ac->entry[i] = ac->entry[ac->avail]; | |
977 | ac->entry[ac->avail] = objp; | |
978 | return objp; | |
979 | } | |
980 | } | |
981 | ||
982 | /* | |
983 | * If there are empty slabs on the slabs_free list and we are | |
984 | * being forced to refill the cache, mark this one !pfmemalloc. | |
985 | */ | |
986 | l3 = cachep->nodelists[numa_mem_id()]; | |
987 | if (!list_empty(&l3->slabs_free) && force_refill) { | |
988 | struct slab *slabp = virt_to_slab(objp); | |
989 | ClearPageSlabPfmemalloc(virt_to_page(slabp->s_mem)); | |
990 | clear_obj_pfmemalloc(&objp); | |
991 | recheck_pfmemalloc_active(cachep, ac); | |
992 | return objp; | |
993 | } | |
994 | ||
995 | /* No !PFMEMALLOC objects available */ | |
996 | ac->avail++; | |
997 | objp = NULL; | |
998 | } | |
999 | ||
1000 | return objp; | |
1001 | } | |
1002 | ||
1003 | static inline void *ac_get_obj(struct kmem_cache *cachep, | |
1004 | struct array_cache *ac, gfp_t flags, bool force_refill) | |
1005 | { | |
1006 | void *objp; | |
1007 | ||
1008 | if (unlikely(sk_memalloc_socks())) | |
1009 | objp = __ac_get_obj(cachep, ac, flags, force_refill); | |
1010 | else | |
1011 | objp = ac->entry[--ac->avail]; | |
1012 | ||
1013 | return objp; | |
1014 | } | |
1015 | ||
1016 | static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, | |
1017 | void *objp) | |
1018 | { | |
1019 | if (unlikely(pfmemalloc_active)) { | |
1020 | /* Some pfmemalloc slabs exist, check if this is one */ | |
1021 | struct page *page = virt_to_page(objp); | |
1022 | if (PageSlabPfmemalloc(page)) | |
1023 | set_obj_pfmemalloc(&objp); | |
1024 | } | |
1025 | ||
1026 | return objp; | |
1027 | } | |
1028 | ||
1029 | static inline void ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac, | |
1030 | void *objp) | |
1031 | { | |
1032 | if (unlikely(sk_memalloc_socks())) | |
1033 | objp = __ac_put_obj(cachep, ac, objp); | |
1034 | ||
1035 | ac->entry[ac->avail++] = objp; | |
1036 | } | |
1037 | ||
1038 | /* | |
1039 | * Transfer objects in one arraycache to another. | |
1040 | * Locking must be handled by the caller. | |
1041 | * | |
1042 | * Return the number of entries transferred. | |
1043 | */ | |
1044 | static int transfer_objects(struct array_cache *to, | |
1045 | struct array_cache *from, unsigned int max) | |
1046 | { | |
1047 | /* Figure out how many entries to transfer */ | |
1048 | int nr = min3(from->avail, max, to->limit - to->avail); | |
1049 | ||
1050 | if (!nr) | |
1051 | return 0; | |
1052 | ||
1053 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, | |
1054 | sizeof(void *) *nr); | |
1055 | ||
1056 | from->avail -= nr; | |
1057 | to->avail += nr; | |
1058 | return nr; | |
1059 | } | |
1060 | ||
1061 | #ifndef CONFIG_NUMA | |
1062 | ||
1063 | #define drain_alien_cache(cachep, alien) do { } while (0) | |
1064 | #define reap_alien(cachep, l3) do { } while (0) | |
1065 | ||
1066 | static inline struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) | |
1067 | { | |
1068 | return (struct array_cache **)BAD_ALIEN_MAGIC; | |
1069 | } | |
1070 | ||
1071 | static inline void free_alien_cache(struct array_cache **ac_ptr) | |
1072 | { | |
1073 | } | |
1074 | ||
1075 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
1076 | { | |
1077 | return 0; | |
1078 | } | |
1079 | ||
1080 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, | |
1081 | gfp_t flags) | |
1082 | { | |
1083 | return NULL; | |
1084 | } | |
1085 | ||
1086 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, | |
1087 | gfp_t flags, int nodeid) | |
1088 | { | |
1089 | return NULL; | |
1090 | } | |
1091 | ||
1092 | #else /* CONFIG_NUMA */ | |
1093 | ||
1094 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); | |
1095 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); | |
1096 | ||
1097 | static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) | |
1098 | { | |
1099 | struct array_cache **ac_ptr; | |
1100 | int memsize = sizeof(void *) * nr_node_ids; | |
1101 | int i; | |
1102 | ||
1103 | if (limit > 1) | |
1104 | limit = 12; | |
1105 | ac_ptr = kzalloc_node(memsize, gfp, node); | |
1106 | if (ac_ptr) { | |
1107 | for_each_node(i) { | |
1108 | if (i == node || !node_online(i)) | |
1109 | continue; | |
1110 | ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp); | |
1111 | if (!ac_ptr[i]) { | |
1112 | for (i--; i >= 0; i--) | |
1113 | kfree(ac_ptr[i]); | |
1114 | kfree(ac_ptr); | |
1115 | return NULL; | |
1116 | } | |
1117 | } | |
1118 | } | |
1119 | return ac_ptr; | |
1120 | } | |
1121 | ||
1122 | static void free_alien_cache(struct array_cache **ac_ptr) | |
1123 | { | |
1124 | int i; | |
1125 | ||
1126 | if (!ac_ptr) | |
1127 | return; | |
1128 | for_each_node(i) | |
1129 | kfree(ac_ptr[i]); | |
1130 | kfree(ac_ptr); | |
1131 | } | |
1132 | ||
1133 | static void __drain_alien_cache(struct kmem_cache *cachep, | |
1134 | struct array_cache *ac, int node) | |
1135 | { | |
1136 | struct kmem_list3 *rl3 = cachep->nodelists[node]; | |
1137 | ||
1138 | if (ac->avail) { | |
1139 | spin_lock(&rl3->list_lock); | |
1140 | /* | |
1141 | * Stuff objects into the remote nodes shared array first. | |
1142 | * That way we could avoid the overhead of putting the objects | |
1143 | * into the free lists and getting them back later. | |
1144 | */ | |
1145 | if (rl3->shared) | |
1146 | transfer_objects(rl3->shared, ac, ac->limit); | |
1147 | ||
1148 | free_block(cachep, ac->entry, ac->avail, node); | |
1149 | ac->avail = 0; | |
1150 | spin_unlock(&rl3->list_lock); | |
1151 | } | |
1152 | } | |
1153 | ||
1154 | /* | |
1155 | * Called from cache_reap() to regularly drain alien caches round robin. | |
1156 | */ | |
1157 | static void reap_alien(struct kmem_cache *cachep, struct kmem_list3 *l3) | |
1158 | { | |
1159 | int node = __this_cpu_read(slab_reap_node); | |
1160 | ||
1161 | if (l3->alien) { | |
1162 | struct array_cache *ac = l3->alien[node]; | |
1163 | ||
1164 | if (ac && ac->avail && spin_trylock_irq(&ac->lock)) { | |
1165 | __drain_alien_cache(cachep, ac, node); | |
1166 | spin_unlock_irq(&ac->lock); | |
1167 | } | |
1168 | } | |
1169 | } | |
1170 | ||
1171 | static void drain_alien_cache(struct kmem_cache *cachep, | |
1172 | struct array_cache **alien) | |
1173 | { | |
1174 | int i = 0; | |
1175 | struct array_cache *ac; | |
1176 | unsigned long flags; | |
1177 | ||
1178 | for_each_online_node(i) { | |
1179 | ac = alien[i]; | |
1180 | if (ac) { | |
1181 | spin_lock_irqsave(&ac->lock, flags); | |
1182 | __drain_alien_cache(cachep, ac, i); | |
1183 | spin_unlock_irqrestore(&ac->lock, flags); | |
1184 | } | |
1185 | } | |
1186 | } | |
1187 | ||
1188 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
1189 | { | |
1190 | struct slab *slabp = virt_to_slab(objp); | |
1191 | int nodeid = slabp->nodeid; | |
1192 | struct kmem_list3 *l3; | |
1193 | struct array_cache *alien = NULL; | |
1194 | int node; | |
1195 | ||
1196 | node = numa_mem_id(); | |
1197 | ||
1198 | /* | |
1199 | * Make sure we are not freeing a object from another node to the array | |
1200 | * cache on this cpu. | |
1201 | */ | |
1202 | if (likely(slabp->nodeid == node)) | |
1203 | return 0; | |
1204 | ||
1205 | l3 = cachep->nodelists[node]; | |
1206 | STATS_INC_NODEFREES(cachep); | |
1207 | if (l3->alien && l3->alien[nodeid]) { | |
1208 | alien = l3->alien[nodeid]; | |
1209 | spin_lock(&alien->lock); | |
1210 | if (unlikely(alien->avail == alien->limit)) { | |
1211 | STATS_INC_ACOVERFLOW(cachep); | |
1212 | __drain_alien_cache(cachep, alien, nodeid); | |
1213 | } | |
1214 | ac_put_obj(cachep, alien, objp); | |
1215 | spin_unlock(&alien->lock); | |
1216 | } else { | |
1217 | spin_lock(&(cachep->nodelists[nodeid])->list_lock); | |
1218 | free_block(cachep, &objp, 1, nodeid); | |
1219 | spin_unlock(&(cachep->nodelists[nodeid])->list_lock); | |
1220 | } | |
1221 | return 1; | |
1222 | } | |
1223 | #endif | |
1224 | ||
1225 | /* | |
1226 | * Allocates and initializes nodelists for a node on each slab cache, used for | |
1227 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_list3 | |
1228 | * will be allocated off-node since memory is not yet online for the new node. | |
1229 | * When hotplugging memory or a cpu, existing nodelists are not replaced if | |
1230 | * already in use. | |
1231 | * | |
1232 | * Must hold slab_mutex. | |
1233 | */ | |
1234 | static int init_cache_nodelists_node(int node) | |
1235 | { | |
1236 | struct kmem_cache *cachep; | |
1237 | struct kmem_list3 *l3; | |
1238 | const int memsize = sizeof(struct kmem_list3); | |
1239 | ||
1240 | list_for_each_entry(cachep, &slab_caches, list) { | |
1241 | /* | |
1242 | * Set up the size64 kmemlist for cpu before we can | |
1243 | * begin anything. Make sure some other cpu on this | |
1244 | * node has not already allocated this | |
1245 | */ | |
1246 | if (!cachep->nodelists[node]) { | |
1247 | l3 = kmalloc_node(memsize, GFP_KERNEL, node); | |
1248 | if (!l3) | |
1249 | return -ENOMEM; | |
1250 | kmem_list3_init(l3); | |
1251 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + | |
1252 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
1253 | ||
1254 | /* | |
1255 | * The l3s don't come and go as CPUs come and | |
1256 | * go. slab_mutex is sufficient | |
1257 | * protection here. | |
1258 | */ | |
1259 | cachep->nodelists[node] = l3; | |
1260 | } | |
1261 | ||
1262 | spin_lock_irq(&cachep->nodelists[node]->list_lock); | |
1263 | cachep->nodelists[node]->free_limit = | |
1264 | (1 + nr_cpus_node(node)) * | |
1265 | cachep->batchcount + cachep->num; | |
1266 | spin_unlock_irq(&cachep->nodelists[node]->list_lock); | |
1267 | } | |
1268 | return 0; | |
1269 | } | |
1270 | ||
1271 | static void __cpuinit cpuup_canceled(long cpu) | |
1272 | { | |
1273 | struct kmem_cache *cachep; | |
1274 | struct kmem_list3 *l3 = NULL; | |
1275 | int node = cpu_to_mem(cpu); | |
1276 | const struct cpumask *mask = cpumask_of_node(node); | |
1277 | ||
1278 | list_for_each_entry(cachep, &slab_caches, list) { | |
1279 | struct array_cache *nc; | |
1280 | struct array_cache *shared; | |
1281 | struct array_cache **alien; | |
1282 | ||
1283 | /* cpu is dead; no one can alloc from it. */ | |
1284 | nc = cachep->array[cpu]; | |
1285 | cachep->array[cpu] = NULL; | |
1286 | l3 = cachep->nodelists[node]; | |
1287 | ||
1288 | if (!l3) | |
1289 | goto free_array_cache; | |
1290 | ||
1291 | spin_lock_irq(&l3->list_lock); | |
1292 | ||
1293 | /* Free limit for this kmem_list3 */ | |
1294 | l3->free_limit -= cachep->batchcount; | |
1295 | if (nc) | |
1296 | free_block(cachep, nc->entry, nc->avail, node); | |
1297 | ||
1298 | if (!cpumask_empty(mask)) { | |
1299 | spin_unlock_irq(&l3->list_lock); | |
1300 | goto free_array_cache; | |
1301 | } | |
1302 | ||
1303 | shared = l3->shared; | |
1304 | if (shared) { | |
1305 | free_block(cachep, shared->entry, | |
1306 | shared->avail, node); | |
1307 | l3->shared = NULL; | |
1308 | } | |
1309 | ||
1310 | alien = l3->alien; | |
1311 | l3->alien = NULL; | |
1312 | ||
1313 | spin_unlock_irq(&l3->list_lock); | |
1314 | ||
1315 | kfree(shared); | |
1316 | if (alien) { | |
1317 | drain_alien_cache(cachep, alien); | |
1318 | free_alien_cache(alien); | |
1319 | } | |
1320 | free_array_cache: | |
1321 | kfree(nc); | |
1322 | } | |
1323 | /* | |
1324 | * In the previous loop, all the objects were freed to | |
1325 | * the respective cache's slabs, now we can go ahead and | |
1326 | * shrink each nodelist to its limit. | |
1327 | */ | |
1328 | list_for_each_entry(cachep, &slab_caches, list) { | |
1329 | l3 = cachep->nodelists[node]; | |
1330 | if (!l3) | |
1331 | continue; | |
1332 | drain_freelist(cachep, l3, l3->free_objects); | |
1333 | } | |
1334 | } | |
1335 | ||
1336 | static int __cpuinit cpuup_prepare(long cpu) | |
1337 | { | |
1338 | struct kmem_cache *cachep; | |
1339 | struct kmem_list3 *l3 = NULL; | |
1340 | int node = cpu_to_mem(cpu); | |
1341 | int err; | |
1342 | ||
1343 | /* | |
1344 | * We need to do this right in the beginning since | |
1345 | * alloc_arraycache's are going to use this list. | |
1346 | * kmalloc_node allows us to add the slab to the right | |
1347 | * kmem_list3 and not this cpu's kmem_list3 | |
1348 | */ | |
1349 | err = init_cache_nodelists_node(node); | |
1350 | if (err < 0) | |
1351 | goto bad; | |
1352 | ||
1353 | /* | |
1354 | * Now we can go ahead with allocating the shared arrays and | |
1355 | * array caches | |
1356 | */ | |
1357 | list_for_each_entry(cachep, &slab_caches, list) { | |
1358 | struct array_cache *nc; | |
1359 | struct array_cache *shared = NULL; | |
1360 | struct array_cache **alien = NULL; | |
1361 | ||
1362 | nc = alloc_arraycache(node, cachep->limit, | |
1363 | cachep->batchcount, GFP_KERNEL); | |
1364 | if (!nc) | |
1365 | goto bad; | |
1366 | if (cachep->shared) { | |
1367 | shared = alloc_arraycache(node, | |
1368 | cachep->shared * cachep->batchcount, | |
1369 | 0xbaadf00d, GFP_KERNEL); | |
1370 | if (!shared) { | |
1371 | kfree(nc); | |
1372 | goto bad; | |
1373 | } | |
1374 | } | |
1375 | if (use_alien_caches) { | |
1376 | alien = alloc_alien_cache(node, cachep->limit, GFP_KERNEL); | |
1377 | if (!alien) { | |
1378 | kfree(shared); | |
1379 | kfree(nc); | |
1380 | goto bad; | |
1381 | } | |
1382 | } | |
1383 | cachep->array[cpu] = nc; | |
1384 | l3 = cachep->nodelists[node]; | |
1385 | BUG_ON(!l3); | |
1386 | ||
1387 | spin_lock_irq(&l3->list_lock); | |
1388 | if (!l3->shared) { | |
1389 | /* | |
1390 | * We are serialised from CPU_DEAD or | |
1391 | * CPU_UP_CANCELLED by the cpucontrol lock | |
1392 | */ | |
1393 | l3->shared = shared; | |
1394 | shared = NULL; | |
1395 | } | |
1396 | #ifdef CONFIG_NUMA | |
1397 | if (!l3->alien) { | |
1398 | l3->alien = alien; | |
1399 | alien = NULL; | |
1400 | } | |
1401 | #endif | |
1402 | spin_unlock_irq(&l3->list_lock); | |
1403 | kfree(shared); | |
1404 | free_alien_cache(alien); | |
1405 | if (cachep->flags & SLAB_DEBUG_OBJECTS) | |
1406 | slab_set_debugobj_lock_classes_node(cachep, node); | |
1407 | } | |
1408 | init_node_lock_keys(node); | |
1409 | ||
1410 | return 0; | |
1411 | bad: | |
1412 | cpuup_canceled(cpu); | |
1413 | return -ENOMEM; | |
1414 | } | |
1415 | ||
1416 | static int __cpuinit cpuup_callback(struct notifier_block *nfb, | |
1417 | unsigned long action, void *hcpu) | |
1418 | { | |
1419 | long cpu = (long)hcpu; | |
1420 | int err = 0; | |
1421 | ||
1422 | switch (action) { | |
1423 | case CPU_UP_PREPARE: | |
1424 | case CPU_UP_PREPARE_FROZEN: | |
1425 | mutex_lock(&slab_mutex); | |
1426 | err = cpuup_prepare(cpu); | |
1427 | mutex_unlock(&slab_mutex); | |
1428 | break; | |
1429 | case CPU_ONLINE: | |
1430 | case CPU_ONLINE_FROZEN: | |
1431 | start_cpu_timer(cpu); | |
1432 | break; | |
1433 | #ifdef CONFIG_HOTPLUG_CPU | |
1434 | case CPU_DOWN_PREPARE: | |
1435 | case CPU_DOWN_PREPARE_FROZEN: | |
1436 | /* | |
1437 | * Shutdown cache reaper. Note that the slab_mutex is | |
1438 | * held so that if cache_reap() is invoked it cannot do | |
1439 | * anything expensive but will only modify reap_work | |
1440 | * and reschedule the timer. | |
1441 | */ | |
1442 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); | |
1443 | /* Now the cache_reaper is guaranteed to be not running. */ | |
1444 | per_cpu(slab_reap_work, cpu).work.func = NULL; | |
1445 | break; | |
1446 | case CPU_DOWN_FAILED: | |
1447 | case CPU_DOWN_FAILED_FROZEN: | |
1448 | start_cpu_timer(cpu); | |
1449 | break; | |
1450 | case CPU_DEAD: | |
1451 | case CPU_DEAD_FROZEN: | |
1452 | /* | |
1453 | * Even if all the cpus of a node are down, we don't free the | |
1454 | * kmem_list3 of any cache. This to avoid a race between | |
1455 | * cpu_down, and a kmalloc allocation from another cpu for | |
1456 | * memory from the node of the cpu going down. The list3 | |
1457 | * structure is usually allocated from kmem_cache_create() and | |
1458 | * gets destroyed at kmem_cache_destroy(). | |
1459 | */ | |
1460 | /* fall through */ | |
1461 | #endif | |
1462 | case CPU_UP_CANCELED: | |
1463 | case CPU_UP_CANCELED_FROZEN: | |
1464 | mutex_lock(&slab_mutex); | |
1465 | cpuup_canceled(cpu); | |
1466 | mutex_unlock(&slab_mutex); | |
1467 | break; | |
1468 | } | |
1469 | return notifier_from_errno(err); | |
1470 | } | |
1471 | ||
1472 | static struct notifier_block __cpuinitdata cpucache_notifier = { | |
1473 | &cpuup_callback, NULL, 0 | |
1474 | }; | |
1475 | ||
1476 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) | |
1477 | /* | |
1478 | * Drains freelist for a node on each slab cache, used for memory hot-remove. | |
1479 | * Returns -EBUSY if all objects cannot be drained so that the node is not | |
1480 | * removed. | |
1481 | * | |
1482 | * Must hold slab_mutex. | |
1483 | */ | |
1484 | static int __meminit drain_cache_nodelists_node(int node) | |
1485 | { | |
1486 | struct kmem_cache *cachep; | |
1487 | int ret = 0; | |
1488 | ||
1489 | list_for_each_entry(cachep, &slab_caches, list) { | |
1490 | struct kmem_list3 *l3; | |
1491 | ||
1492 | l3 = cachep->nodelists[node]; | |
1493 | if (!l3) | |
1494 | continue; | |
1495 | ||
1496 | drain_freelist(cachep, l3, l3->free_objects); | |
1497 | ||
1498 | if (!list_empty(&l3->slabs_full) || | |
1499 | !list_empty(&l3->slabs_partial)) { | |
1500 | ret = -EBUSY; | |
1501 | break; | |
1502 | } | |
1503 | } | |
1504 | return ret; | |
1505 | } | |
1506 | ||
1507 | static int __meminit slab_memory_callback(struct notifier_block *self, | |
1508 | unsigned long action, void *arg) | |
1509 | { | |
1510 | struct memory_notify *mnb = arg; | |
1511 | int ret = 0; | |
1512 | int nid; | |
1513 | ||
1514 | nid = mnb->status_change_nid; | |
1515 | if (nid < 0) | |
1516 | goto out; | |
1517 | ||
1518 | switch (action) { | |
1519 | case MEM_GOING_ONLINE: | |
1520 | mutex_lock(&slab_mutex); | |
1521 | ret = init_cache_nodelists_node(nid); | |
1522 | mutex_unlock(&slab_mutex); | |
1523 | break; | |
1524 | case MEM_GOING_OFFLINE: | |
1525 | mutex_lock(&slab_mutex); | |
1526 | ret = drain_cache_nodelists_node(nid); | |
1527 | mutex_unlock(&slab_mutex); | |
1528 | break; | |
1529 | case MEM_ONLINE: | |
1530 | case MEM_OFFLINE: | |
1531 | case MEM_CANCEL_ONLINE: | |
1532 | case MEM_CANCEL_OFFLINE: | |
1533 | break; | |
1534 | } | |
1535 | out: | |
1536 | return notifier_from_errno(ret); | |
1537 | } | |
1538 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ | |
1539 | ||
1540 | /* | |
1541 | * swap the static kmem_list3 with kmalloced memory | |
1542 | */ | |
1543 | static void __init init_list(struct kmem_cache *cachep, struct kmem_list3 *list, | |
1544 | int nodeid) | |
1545 | { | |
1546 | struct kmem_list3 *ptr; | |
1547 | ||
1548 | ptr = kmalloc_node(sizeof(struct kmem_list3), GFP_NOWAIT, nodeid); | |
1549 | BUG_ON(!ptr); | |
1550 | ||
1551 | memcpy(ptr, list, sizeof(struct kmem_list3)); | |
1552 | /* | |
1553 | * Do not assume that spinlocks can be initialized via memcpy: | |
1554 | */ | |
1555 | spin_lock_init(&ptr->list_lock); | |
1556 | ||
1557 | MAKE_ALL_LISTS(cachep, ptr, nodeid); | |
1558 | cachep->nodelists[nodeid] = ptr; | |
1559 | } | |
1560 | ||
1561 | /* | |
1562 | * For setting up all the kmem_list3s for cache whose buffer_size is same as | |
1563 | * size of kmem_list3. | |
1564 | */ | |
1565 | static void __init set_up_list3s(struct kmem_cache *cachep, int index) | |
1566 | { | |
1567 | int node; | |
1568 | ||
1569 | for_each_online_node(node) { | |
1570 | cachep->nodelists[node] = &initkmem_list3[index + node]; | |
1571 | cachep->nodelists[node]->next_reap = jiffies + | |
1572 | REAPTIMEOUT_LIST3 + | |
1573 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
1574 | } | |
1575 | } | |
1576 | ||
1577 | /* | |
1578 | * Initialisation. Called after the page allocator have been initialised and | |
1579 | * before smp_init(). | |
1580 | */ | |
1581 | void __init kmem_cache_init(void) | |
1582 | { | |
1583 | size_t left_over; | |
1584 | struct cache_sizes *sizes; | |
1585 | struct cache_names *names; | |
1586 | int i; | |
1587 | int order; | |
1588 | int node; | |
1589 | ||
1590 | if (num_possible_nodes() == 1) | |
1591 | use_alien_caches = 0; | |
1592 | ||
1593 | for (i = 0; i < NUM_INIT_LISTS; i++) { | |
1594 | kmem_list3_init(&initkmem_list3[i]); | |
1595 | if (i < MAX_NUMNODES) | |
1596 | cache_cache.nodelists[i] = NULL; | |
1597 | } | |
1598 | set_up_list3s(&cache_cache, CACHE_CACHE); | |
1599 | ||
1600 | /* | |
1601 | * Fragmentation resistance on low memory - only use bigger | |
1602 | * page orders on machines with more than 32MB of memory if | |
1603 | * not overridden on the command line. | |
1604 | */ | |
1605 | if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) | |
1606 | slab_max_order = SLAB_MAX_ORDER_HI; | |
1607 | ||
1608 | /* Bootstrap is tricky, because several objects are allocated | |
1609 | * from caches that do not exist yet: | |
1610 | * 1) initialize the cache_cache cache: it contains the struct | |
1611 | * kmem_cache structures of all caches, except cache_cache itself: | |
1612 | * cache_cache is statically allocated. | |
1613 | * Initially an __init data area is used for the head array and the | |
1614 | * kmem_list3 structures, it's replaced with a kmalloc allocated | |
1615 | * array at the end of the bootstrap. | |
1616 | * 2) Create the first kmalloc cache. | |
1617 | * The struct kmem_cache for the new cache is allocated normally. | |
1618 | * An __init data area is used for the head array. | |
1619 | * 3) Create the remaining kmalloc caches, with minimally sized | |
1620 | * head arrays. | |
1621 | * 4) Replace the __init data head arrays for cache_cache and the first | |
1622 | * kmalloc cache with kmalloc allocated arrays. | |
1623 | * 5) Replace the __init data for kmem_list3 for cache_cache and | |
1624 | * the other cache's with kmalloc allocated memory. | |
1625 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. | |
1626 | */ | |
1627 | ||
1628 | node = numa_mem_id(); | |
1629 | ||
1630 | /* 1) create the cache_cache */ | |
1631 | INIT_LIST_HEAD(&slab_caches); | |
1632 | list_add(&cache_cache.list, &slab_caches); | |
1633 | cache_cache.colour_off = cache_line_size(); | |
1634 | cache_cache.array[smp_processor_id()] = &initarray_cache.cache; | |
1635 | cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE + node]; | |
1636 | ||
1637 | /* | |
1638 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids | |
1639 | */ | |
1640 | cache_cache.size = offsetof(struct kmem_cache, array[nr_cpu_ids]) + | |
1641 | nr_node_ids * sizeof(struct kmem_list3 *); | |
1642 | cache_cache.object_size = cache_cache.size; | |
1643 | cache_cache.size = ALIGN(cache_cache.size, | |
1644 | cache_line_size()); | |
1645 | cache_cache.reciprocal_buffer_size = | |
1646 | reciprocal_value(cache_cache.size); | |
1647 | ||
1648 | for (order = 0; order < MAX_ORDER; order++) { | |
1649 | cache_estimate(order, cache_cache.size, | |
1650 | cache_line_size(), 0, &left_over, &cache_cache.num); | |
1651 | if (cache_cache.num) | |
1652 | break; | |
1653 | } | |
1654 | BUG_ON(!cache_cache.num); | |
1655 | cache_cache.gfporder = order; | |
1656 | cache_cache.colour = left_over / cache_cache.colour_off; | |
1657 | cache_cache.slab_size = ALIGN(cache_cache.num * sizeof(kmem_bufctl_t) + | |
1658 | sizeof(struct slab), cache_line_size()); | |
1659 | ||
1660 | /* 2+3) create the kmalloc caches */ | |
1661 | sizes = malloc_sizes; | |
1662 | names = cache_names; | |
1663 | ||
1664 | /* | |
1665 | * Initialize the caches that provide memory for the array cache and the | |
1666 | * kmem_list3 structures first. Without this, further allocations will | |
1667 | * bug. | |
1668 | */ | |
1669 | ||
1670 | sizes[INDEX_AC].cs_cachep = __kmem_cache_create(names[INDEX_AC].name, | |
1671 | sizes[INDEX_AC].cs_size, | |
1672 | ARCH_KMALLOC_MINALIGN, | |
1673 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, | |
1674 | NULL); | |
1675 | ||
1676 | if (INDEX_AC != INDEX_L3) { | |
1677 | sizes[INDEX_L3].cs_cachep = | |
1678 | __kmem_cache_create(names[INDEX_L3].name, | |
1679 | sizes[INDEX_L3].cs_size, | |
1680 | ARCH_KMALLOC_MINALIGN, | |
1681 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, | |
1682 | NULL); | |
1683 | } | |
1684 | ||
1685 | slab_early_init = 0; | |
1686 | ||
1687 | while (sizes->cs_size != ULONG_MAX) { | |
1688 | /* | |
1689 | * For performance, all the general caches are L1 aligned. | |
1690 | * This should be particularly beneficial on SMP boxes, as it | |
1691 | * eliminates "false sharing". | |
1692 | * Note for systems short on memory removing the alignment will | |
1693 | * allow tighter packing of the smaller caches. | |
1694 | */ | |
1695 | if (!sizes->cs_cachep) { | |
1696 | sizes->cs_cachep = __kmem_cache_create(names->name, | |
1697 | sizes->cs_size, | |
1698 | ARCH_KMALLOC_MINALIGN, | |
1699 | ARCH_KMALLOC_FLAGS|SLAB_PANIC, | |
1700 | NULL); | |
1701 | } | |
1702 | #ifdef CONFIG_ZONE_DMA | |
1703 | sizes->cs_dmacachep = __kmem_cache_create( | |
1704 | names->name_dma, | |
1705 | sizes->cs_size, | |
1706 | ARCH_KMALLOC_MINALIGN, | |
1707 | ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA| | |
1708 | SLAB_PANIC, | |
1709 | NULL); | |
1710 | #endif | |
1711 | sizes++; | |
1712 | names++; | |
1713 | } | |
1714 | /* 4) Replace the bootstrap head arrays */ | |
1715 | { | |
1716 | struct array_cache *ptr; | |
1717 | ||
1718 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); | |
1719 | ||
1720 | BUG_ON(cpu_cache_get(&cache_cache) != &initarray_cache.cache); | |
1721 | memcpy(ptr, cpu_cache_get(&cache_cache), | |
1722 | sizeof(struct arraycache_init)); | |
1723 | /* | |
1724 | * Do not assume that spinlocks can be initialized via memcpy: | |
1725 | */ | |
1726 | spin_lock_init(&ptr->lock); | |
1727 | ||
1728 | cache_cache.array[smp_processor_id()] = ptr; | |
1729 | ||
1730 | ptr = kmalloc(sizeof(struct arraycache_init), GFP_NOWAIT); | |
1731 | ||
1732 | BUG_ON(cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep) | |
1733 | != &initarray_generic.cache); | |
1734 | memcpy(ptr, cpu_cache_get(malloc_sizes[INDEX_AC].cs_cachep), | |
1735 | sizeof(struct arraycache_init)); | |
1736 | /* | |
1737 | * Do not assume that spinlocks can be initialized via memcpy: | |
1738 | */ | |
1739 | spin_lock_init(&ptr->lock); | |
1740 | ||
1741 | malloc_sizes[INDEX_AC].cs_cachep->array[smp_processor_id()] = | |
1742 | ptr; | |
1743 | } | |
1744 | /* 5) Replace the bootstrap kmem_list3's */ | |
1745 | { | |
1746 | int nid; | |
1747 | ||
1748 | for_each_online_node(nid) { | |
1749 | init_list(&cache_cache, &initkmem_list3[CACHE_CACHE + nid], nid); | |
1750 | ||
1751 | init_list(malloc_sizes[INDEX_AC].cs_cachep, | |
1752 | &initkmem_list3[SIZE_AC + nid], nid); | |
1753 | ||
1754 | if (INDEX_AC != INDEX_L3) { | |
1755 | init_list(malloc_sizes[INDEX_L3].cs_cachep, | |
1756 | &initkmem_list3[SIZE_L3 + nid], nid); | |
1757 | } | |
1758 | } | |
1759 | } | |
1760 | ||
1761 | slab_state = UP; | |
1762 | } | |
1763 | ||
1764 | void __init kmem_cache_init_late(void) | |
1765 | { | |
1766 | struct kmem_cache *cachep; | |
1767 | ||
1768 | slab_state = UP; | |
1769 | ||
1770 | /* 6) resize the head arrays to their final sizes */ | |
1771 | mutex_lock(&slab_mutex); | |
1772 | list_for_each_entry(cachep, &slab_caches, list) | |
1773 | if (enable_cpucache(cachep, GFP_NOWAIT)) | |
1774 | BUG(); | |
1775 | mutex_unlock(&slab_mutex); | |
1776 | ||
1777 | /* Annotate slab for lockdep -- annotate the malloc caches */ | |
1778 | init_lock_keys(); | |
1779 | ||
1780 | /* Done! */ | |
1781 | slab_state = FULL; | |
1782 | ||
1783 | /* | |
1784 | * Register a cpu startup notifier callback that initializes | |
1785 | * cpu_cache_get for all new cpus | |
1786 | */ | |
1787 | register_cpu_notifier(&cpucache_notifier); | |
1788 | ||
1789 | #ifdef CONFIG_NUMA | |
1790 | /* | |
1791 | * Register a memory hotplug callback that initializes and frees | |
1792 | * nodelists. | |
1793 | */ | |
1794 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); | |
1795 | #endif | |
1796 | ||
1797 | /* | |
1798 | * The reap timers are started later, with a module init call: That part | |
1799 | * of the kernel is not yet operational. | |
1800 | */ | |
1801 | } | |
1802 | ||
1803 | static int __init cpucache_init(void) | |
1804 | { | |
1805 | int cpu; | |
1806 | ||
1807 | /* | |
1808 | * Register the timers that return unneeded pages to the page allocator | |
1809 | */ | |
1810 | for_each_online_cpu(cpu) | |
1811 | start_cpu_timer(cpu); | |
1812 | ||
1813 | /* Done! */ | |
1814 | slab_state = FULL; | |
1815 | return 0; | |
1816 | } | |
1817 | __initcall(cpucache_init); | |
1818 | ||
1819 | static noinline void | |
1820 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) | |
1821 | { | |
1822 | struct kmem_list3 *l3; | |
1823 | struct slab *slabp; | |
1824 | unsigned long flags; | |
1825 | int node; | |
1826 | ||
1827 | printk(KERN_WARNING | |
1828 | "SLAB: Unable to allocate memory on node %d (gfp=0x%x)\n", | |
1829 | nodeid, gfpflags); | |
1830 | printk(KERN_WARNING " cache: %s, object size: %d, order: %d\n", | |
1831 | cachep->name, cachep->size, cachep->gfporder); | |
1832 | ||
1833 | for_each_online_node(node) { | |
1834 | unsigned long active_objs = 0, num_objs = 0, free_objects = 0; | |
1835 | unsigned long active_slabs = 0, num_slabs = 0; | |
1836 | ||
1837 | l3 = cachep->nodelists[node]; | |
1838 | if (!l3) | |
1839 | continue; | |
1840 | ||
1841 | spin_lock_irqsave(&l3->list_lock, flags); | |
1842 | list_for_each_entry(slabp, &l3->slabs_full, list) { | |
1843 | active_objs += cachep->num; | |
1844 | active_slabs++; | |
1845 | } | |
1846 | list_for_each_entry(slabp, &l3->slabs_partial, list) { | |
1847 | active_objs += slabp->inuse; | |
1848 | active_slabs++; | |
1849 | } | |
1850 | list_for_each_entry(slabp, &l3->slabs_free, list) | |
1851 | num_slabs++; | |
1852 | ||
1853 | free_objects += l3->free_objects; | |
1854 | spin_unlock_irqrestore(&l3->list_lock, flags); | |
1855 | ||
1856 | num_slabs += active_slabs; | |
1857 | num_objs = num_slabs * cachep->num; | |
1858 | printk(KERN_WARNING | |
1859 | " node %d: slabs: %ld/%ld, objs: %ld/%ld, free: %ld\n", | |
1860 | node, active_slabs, num_slabs, active_objs, num_objs, | |
1861 | free_objects); | |
1862 | } | |
1863 | } | |
1864 | ||
1865 | /* | |
1866 | * Interface to system's page allocator. No need to hold the cache-lock. | |
1867 | * | |
1868 | * If we requested dmaable memory, we will get it. Even if we | |
1869 | * did not request dmaable memory, we might get it, but that | |
1870 | * would be relatively rare and ignorable. | |
1871 | */ | |
1872 | static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid) | |
1873 | { | |
1874 | struct page *page; | |
1875 | int nr_pages; | |
1876 | int i; | |
1877 | ||
1878 | #ifndef CONFIG_MMU | |
1879 | /* | |
1880 | * Nommu uses slab's for process anonymous memory allocations, and thus | |
1881 | * requires __GFP_COMP to properly refcount higher order allocations | |
1882 | */ | |
1883 | flags |= __GFP_COMP; | |
1884 | #endif | |
1885 | ||
1886 | flags |= cachep->allocflags; | |
1887 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1888 | flags |= __GFP_RECLAIMABLE; | |
1889 | ||
1890 | page = alloc_pages_exact_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); | |
1891 | if (!page) { | |
1892 | if (!(flags & __GFP_NOWARN) && printk_ratelimit()) | |
1893 | slab_out_of_memory(cachep, flags, nodeid); | |
1894 | return NULL; | |
1895 | } | |
1896 | ||
1897 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ | |
1898 | if (unlikely(page->pfmemalloc)) | |
1899 | pfmemalloc_active = true; | |
1900 | ||
1901 | nr_pages = (1 << cachep->gfporder); | |
1902 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1903 | add_zone_page_state(page_zone(page), | |
1904 | NR_SLAB_RECLAIMABLE, nr_pages); | |
1905 | else | |
1906 | add_zone_page_state(page_zone(page), | |
1907 | NR_SLAB_UNRECLAIMABLE, nr_pages); | |
1908 | for (i = 0; i < nr_pages; i++) { | |
1909 | __SetPageSlab(page + i); | |
1910 | ||
1911 | if (page->pfmemalloc) | |
1912 | SetPageSlabPfmemalloc(page + i); | |
1913 | } | |
1914 | ||
1915 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { | |
1916 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); | |
1917 | ||
1918 | if (cachep->ctor) | |
1919 | kmemcheck_mark_uninitialized_pages(page, nr_pages); | |
1920 | else | |
1921 | kmemcheck_mark_unallocated_pages(page, nr_pages); | |
1922 | } | |
1923 | ||
1924 | return page_address(page); | |
1925 | } | |
1926 | ||
1927 | /* | |
1928 | * Interface to system's page release. | |
1929 | */ | |
1930 | static void kmem_freepages(struct kmem_cache *cachep, void *addr) | |
1931 | { | |
1932 | unsigned long i = (1 << cachep->gfporder); | |
1933 | struct page *page = virt_to_page(addr); | |
1934 | const unsigned long nr_freed = i; | |
1935 | ||
1936 | kmemcheck_free_shadow(page, cachep->gfporder); | |
1937 | ||
1938 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1939 | sub_zone_page_state(page_zone(page), | |
1940 | NR_SLAB_RECLAIMABLE, nr_freed); | |
1941 | else | |
1942 | sub_zone_page_state(page_zone(page), | |
1943 | NR_SLAB_UNRECLAIMABLE, nr_freed); | |
1944 | while (i--) { | |
1945 | BUG_ON(!PageSlab(page)); | |
1946 | __ClearPageSlabPfmemalloc(page); | |
1947 | __ClearPageSlab(page); | |
1948 | page++; | |
1949 | } | |
1950 | if (current->reclaim_state) | |
1951 | current->reclaim_state->reclaimed_slab += nr_freed; | |
1952 | free_pages((unsigned long)addr, cachep->gfporder); | |
1953 | } | |
1954 | ||
1955 | static void kmem_rcu_free(struct rcu_head *head) | |
1956 | { | |
1957 | struct slab_rcu *slab_rcu = (struct slab_rcu *)head; | |
1958 | struct kmem_cache *cachep = slab_rcu->cachep; | |
1959 | ||
1960 | kmem_freepages(cachep, slab_rcu->addr); | |
1961 | if (OFF_SLAB(cachep)) | |
1962 | kmem_cache_free(cachep->slabp_cache, slab_rcu); | |
1963 | } | |
1964 | ||
1965 | #if DEBUG | |
1966 | ||
1967 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1968 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, | |
1969 | unsigned long caller) | |
1970 | { | |
1971 | int size = cachep->object_size; | |
1972 | ||
1973 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; | |
1974 | ||
1975 | if (size < 5 * sizeof(unsigned long)) | |
1976 | return; | |
1977 | ||
1978 | *addr++ = 0x12345678; | |
1979 | *addr++ = caller; | |
1980 | *addr++ = smp_processor_id(); | |
1981 | size -= 3 * sizeof(unsigned long); | |
1982 | { | |
1983 | unsigned long *sptr = &caller; | |
1984 | unsigned long svalue; | |
1985 | ||
1986 | while (!kstack_end(sptr)) { | |
1987 | svalue = *sptr++; | |
1988 | if (kernel_text_address(svalue)) { | |
1989 | *addr++ = svalue; | |
1990 | size -= sizeof(unsigned long); | |
1991 | if (size <= sizeof(unsigned long)) | |
1992 | break; | |
1993 | } | |
1994 | } | |
1995 | ||
1996 | } | |
1997 | *addr++ = 0x87654321; | |
1998 | } | |
1999 | #endif | |
2000 | ||
2001 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) | |
2002 | { | |
2003 | int size = cachep->object_size; | |
2004 | addr = &((char *)addr)[obj_offset(cachep)]; | |
2005 | ||
2006 | memset(addr, val, size); | |
2007 | *(unsigned char *)(addr + size - 1) = POISON_END; | |
2008 | } | |
2009 | ||
2010 | static void dump_line(char *data, int offset, int limit) | |
2011 | { | |
2012 | int i; | |
2013 | unsigned char error = 0; | |
2014 | int bad_count = 0; | |
2015 | ||
2016 | printk(KERN_ERR "%03x: ", offset); | |
2017 | for (i = 0; i < limit; i++) { | |
2018 | if (data[offset + i] != POISON_FREE) { | |
2019 | error = data[offset + i]; | |
2020 | bad_count++; | |
2021 | } | |
2022 | } | |
2023 | print_hex_dump(KERN_CONT, "", 0, 16, 1, | |
2024 | &data[offset], limit, 1); | |
2025 | ||
2026 | if (bad_count == 1) { | |
2027 | error ^= POISON_FREE; | |
2028 | if (!(error & (error - 1))) { | |
2029 | printk(KERN_ERR "Single bit error detected. Probably " | |
2030 | "bad RAM.\n"); | |
2031 | #ifdef CONFIG_X86 | |
2032 | printk(KERN_ERR "Run memtest86+ or a similar memory " | |
2033 | "test tool.\n"); | |
2034 | #else | |
2035 | printk(KERN_ERR "Run a memory test tool.\n"); | |
2036 | #endif | |
2037 | } | |
2038 | } | |
2039 | } | |
2040 | #endif | |
2041 | ||
2042 | #if DEBUG | |
2043 | ||
2044 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) | |
2045 | { | |
2046 | int i, size; | |
2047 | char *realobj; | |
2048 | ||
2049 | if (cachep->flags & SLAB_RED_ZONE) { | |
2050 | printk(KERN_ERR "Redzone: 0x%llx/0x%llx.\n", | |
2051 | *dbg_redzone1(cachep, objp), | |
2052 | *dbg_redzone2(cachep, objp)); | |
2053 | } | |
2054 | ||
2055 | if (cachep->flags & SLAB_STORE_USER) { | |
2056 | printk(KERN_ERR "Last user: [<%p>]", | |
2057 | *dbg_userword(cachep, objp)); | |
2058 | print_symbol("(%s)", | |
2059 | (unsigned long)*dbg_userword(cachep, objp)); | |
2060 | printk("\n"); | |
2061 | } | |
2062 | realobj = (char *)objp + obj_offset(cachep); | |
2063 | size = cachep->object_size; | |
2064 | for (i = 0; i < size && lines; i += 16, lines--) { | |
2065 | int limit; | |
2066 | limit = 16; | |
2067 | if (i + limit > size) | |
2068 | limit = size - i; | |
2069 | dump_line(realobj, i, limit); | |
2070 | } | |
2071 | } | |
2072 | ||
2073 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) | |
2074 | { | |
2075 | char *realobj; | |
2076 | int size, i; | |
2077 | int lines = 0; | |
2078 | ||
2079 | realobj = (char *)objp + obj_offset(cachep); | |
2080 | size = cachep->object_size; | |
2081 | ||
2082 | for (i = 0; i < size; i++) { | |
2083 | char exp = POISON_FREE; | |
2084 | if (i == size - 1) | |
2085 | exp = POISON_END; | |
2086 | if (realobj[i] != exp) { | |
2087 | int limit; | |
2088 | /* Mismatch ! */ | |
2089 | /* Print header */ | |
2090 | if (lines == 0) { | |
2091 | printk(KERN_ERR | |
2092 | "Slab corruption (%s): %s start=%p, len=%d\n", | |
2093 | print_tainted(), cachep->name, realobj, size); | |
2094 | print_objinfo(cachep, objp, 0); | |
2095 | } | |
2096 | /* Hexdump the affected line */ | |
2097 | i = (i / 16) * 16; | |
2098 | limit = 16; | |
2099 | if (i + limit > size) | |
2100 | limit = size - i; | |
2101 | dump_line(realobj, i, limit); | |
2102 | i += 16; | |
2103 | lines++; | |
2104 | /* Limit to 5 lines */ | |
2105 | if (lines > 5) | |
2106 | break; | |
2107 | } | |
2108 | } | |
2109 | if (lines != 0) { | |
2110 | /* Print some data about the neighboring objects, if they | |
2111 | * exist: | |
2112 | */ | |
2113 | struct slab *slabp = virt_to_slab(objp); | |
2114 | unsigned int objnr; | |
2115 | ||
2116 | objnr = obj_to_index(cachep, slabp, objp); | |
2117 | if (objnr) { | |
2118 | objp = index_to_obj(cachep, slabp, objnr - 1); | |
2119 | realobj = (char *)objp + obj_offset(cachep); | |
2120 | printk(KERN_ERR "Prev obj: start=%p, len=%d\n", | |
2121 | realobj, size); | |
2122 | print_objinfo(cachep, objp, 2); | |
2123 | } | |
2124 | if (objnr + 1 < cachep->num) { | |
2125 | objp = index_to_obj(cachep, slabp, objnr + 1); | |
2126 | realobj = (char *)objp + obj_offset(cachep); | |
2127 | printk(KERN_ERR "Next obj: start=%p, len=%d\n", | |
2128 | realobj, size); | |
2129 | print_objinfo(cachep, objp, 2); | |
2130 | } | |
2131 | } | |
2132 | } | |
2133 | #endif | |
2134 | ||
2135 | #if DEBUG | |
2136 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) | |
2137 | { | |
2138 | int i; | |
2139 | for (i = 0; i < cachep->num; i++) { | |
2140 | void *objp = index_to_obj(cachep, slabp, i); | |
2141 | ||
2142 | if (cachep->flags & SLAB_POISON) { | |
2143 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
2144 | if (cachep->size % PAGE_SIZE == 0 && | |
2145 | OFF_SLAB(cachep)) | |
2146 | kernel_map_pages(virt_to_page(objp), | |
2147 | cachep->size / PAGE_SIZE, 1); | |
2148 | else | |
2149 | check_poison_obj(cachep, objp); | |
2150 | #else | |
2151 | check_poison_obj(cachep, objp); | |
2152 | #endif | |
2153 | } | |
2154 | if (cachep->flags & SLAB_RED_ZONE) { | |
2155 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
2156 | slab_error(cachep, "start of a freed object " | |
2157 | "was overwritten"); | |
2158 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
2159 | slab_error(cachep, "end of a freed object " | |
2160 | "was overwritten"); | |
2161 | } | |
2162 | } | |
2163 | } | |
2164 | #else | |
2165 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp) | |
2166 | { | |
2167 | } | |
2168 | #endif | |
2169 | ||
2170 | /** | |
2171 | * slab_destroy - destroy and release all objects in a slab | |
2172 | * @cachep: cache pointer being destroyed | |
2173 | * @slabp: slab pointer being destroyed | |
2174 | * | |
2175 | * Destroy all the objs in a slab, and release the mem back to the system. | |
2176 | * Before calling the slab must have been unlinked from the cache. The | |
2177 | * cache-lock is not held/needed. | |
2178 | */ | |
2179 | static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp) | |
2180 | { | |
2181 | void *addr = slabp->s_mem - slabp->colouroff; | |
2182 | ||
2183 | slab_destroy_debugcheck(cachep, slabp); | |
2184 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) { | |
2185 | struct slab_rcu *slab_rcu; | |
2186 | ||
2187 | slab_rcu = (struct slab_rcu *)slabp; | |
2188 | slab_rcu->cachep = cachep; | |
2189 | slab_rcu->addr = addr; | |
2190 | call_rcu(&slab_rcu->head, kmem_rcu_free); | |
2191 | } else { | |
2192 | kmem_freepages(cachep, addr); | |
2193 | if (OFF_SLAB(cachep)) | |
2194 | kmem_cache_free(cachep->slabp_cache, slabp); | |
2195 | } | |
2196 | } | |
2197 | ||
2198 | static void __kmem_cache_destroy(struct kmem_cache *cachep) | |
2199 | { | |
2200 | int i; | |
2201 | struct kmem_list3 *l3; | |
2202 | ||
2203 | for_each_online_cpu(i) | |
2204 | kfree(cachep->array[i]); | |
2205 | ||
2206 | /* NUMA: free the list3 structures */ | |
2207 | for_each_online_node(i) { | |
2208 | l3 = cachep->nodelists[i]; | |
2209 | if (l3) { | |
2210 | kfree(l3->shared); | |
2211 | free_alien_cache(l3->alien); | |
2212 | kfree(l3); | |
2213 | } | |
2214 | } | |
2215 | kmem_cache_free(&cache_cache, cachep); | |
2216 | } | |
2217 | ||
2218 | ||
2219 | /** | |
2220 | * calculate_slab_order - calculate size (page order) of slabs | |
2221 | * @cachep: pointer to the cache that is being created | |
2222 | * @size: size of objects to be created in this cache. | |
2223 | * @align: required alignment for the objects. | |
2224 | * @flags: slab allocation flags | |
2225 | * | |
2226 | * Also calculates the number of objects per slab. | |
2227 | * | |
2228 | * This could be made much more intelligent. For now, try to avoid using | |
2229 | * high order pages for slabs. When the gfp() functions are more friendly | |
2230 | * towards high-order requests, this should be changed. | |
2231 | */ | |
2232 | static size_t calculate_slab_order(struct kmem_cache *cachep, | |
2233 | size_t size, size_t align, unsigned long flags) | |
2234 | { | |
2235 | unsigned long offslab_limit; | |
2236 | size_t left_over = 0; | |
2237 | int gfporder; | |
2238 | ||
2239 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { | |
2240 | unsigned int num; | |
2241 | size_t remainder; | |
2242 | ||
2243 | cache_estimate(gfporder, size, align, flags, &remainder, &num); | |
2244 | if (!num) | |
2245 | continue; | |
2246 | ||
2247 | if (flags & CFLGS_OFF_SLAB) { | |
2248 | /* | |
2249 | * Max number of objs-per-slab for caches which | |
2250 | * use off-slab slabs. Needed to avoid a possible | |
2251 | * looping condition in cache_grow(). | |
2252 | */ | |
2253 | offslab_limit = size - sizeof(struct slab); | |
2254 | offslab_limit /= sizeof(kmem_bufctl_t); | |
2255 | ||
2256 | if (num > offslab_limit) | |
2257 | break; | |
2258 | } | |
2259 | ||
2260 | /* Found something acceptable - save it away */ | |
2261 | cachep->num = num; | |
2262 | cachep->gfporder = gfporder; | |
2263 | left_over = remainder; | |
2264 | ||
2265 | /* | |
2266 | * A VFS-reclaimable slab tends to have most allocations | |
2267 | * as GFP_NOFS and we really don't want to have to be allocating | |
2268 | * higher-order pages when we are unable to shrink dcache. | |
2269 | */ | |
2270 | if (flags & SLAB_RECLAIM_ACCOUNT) | |
2271 | break; | |
2272 | ||
2273 | /* | |
2274 | * Large number of objects is good, but very large slabs are | |
2275 | * currently bad for the gfp()s. | |
2276 | */ | |
2277 | if (gfporder >= slab_max_order) | |
2278 | break; | |
2279 | ||
2280 | /* | |
2281 | * Acceptable internal fragmentation? | |
2282 | */ | |
2283 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) | |
2284 | break; | |
2285 | } | |
2286 | return left_over; | |
2287 | } | |
2288 | ||
2289 | static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) | |
2290 | { | |
2291 | if (slab_state >= FULL) | |
2292 | return enable_cpucache(cachep, gfp); | |
2293 | ||
2294 | if (slab_state == DOWN) { | |
2295 | /* | |
2296 | * Note: the first kmem_cache_create must create the cache | |
2297 | * that's used by kmalloc(24), otherwise the creation of | |
2298 | * further caches will BUG(). | |
2299 | */ | |
2300 | cachep->array[smp_processor_id()] = &initarray_generic.cache; | |
2301 | ||
2302 | /* | |
2303 | * If the cache that's used by kmalloc(sizeof(kmem_list3)) is | |
2304 | * the first cache, then we need to set up all its list3s, | |
2305 | * otherwise the creation of further caches will BUG(). | |
2306 | */ | |
2307 | set_up_list3s(cachep, SIZE_AC); | |
2308 | if (INDEX_AC == INDEX_L3) | |
2309 | slab_state = PARTIAL_L3; | |
2310 | else | |
2311 | slab_state = PARTIAL_ARRAYCACHE; | |
2312 | } else { | |
2313 | cachep->array[smp_processor_id()] = | |
2314 | kmalloc(sizeof(struct arraycache_init), gfp); | |
2315 | ||
2316 | if (slab_state == PARTIAL_ARRAYCACHE) { | |
2317 | set_up_list3s(cachep, SIZE_L3); | |
2318 | slab_state = PARTIAL_L3; | |
2319 | } else { | |
2320 | int node; | |
2321 | for_each_online_node(node) { | |
2322 | cachep->nodelists[node] = | |
2323 | kmalloc_node(sizeof(struct kmem_list3), | |
2324 | gfp, node); | |
2325 | BUG_ON(!cachep->nodelists[node]); | |
2326 | kmem_list3_init(cachep->nodelists[node]); | |
2327 | } | |
2328 | } | |
2329 | } | |
2330 | cachep->nodelists[numa_mem_id()]->next_reap = | |
2331 | jiffies + REAPTIMEOUT_LIST3 + | |
2332 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
2333 | ||
2334 | cpu_cache_get(cachep)->avail = 0; | |
2335 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; | |
2336 | cpu_cache_get(cachep)->batchcount = 1; | |
2337 | cpu_cache_get(cachep)->touched = 0; | |
2338 | cachep->batchcount = 1; | |
2339 | cachep->limit = BOOT_CPUCACHE_ENTRIES; | |
2340 | return 0; | |
2341 | } | |
2342 | ||
2343 | /** | |
2344 | * __kmem_cache_create - Create a cache. | |
2345 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
2346 | * @size: The size of objects to be created in this cache. | |
2347 | * @align: The required alignment for the objects. | |
2348 | * @flags: SLAB flags | |
2349 | * @ctor: A constructor for the objects. | |
2350 | * | |
2351 | * Returns a ptr to the cache on success, NULL on failure. | |
2352 | * Cannot be called within a int, but can be interrupted. | |
2353 | * The @ctor is run when new pages are allocated by the cache. | |
2354 | * | |
2355 | * @name must be valid until the cache is destroyed. This implies that | |
2356 | * the module calling this has to destroy the cache before getting unloaded. | |
2357 | * | |
2358 | * The flags are | |
2359 | * | |
2360 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
2361 | * to catch references to uninitialised memory. | |
2362 | * | |
2363 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
2364 | * for buffer overruns. | |
2365 | * | |
2366 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
2367 | * cacheline. This can be beneficial if you're counting cycles as closely | |
2368 | * as davem. | |
2369 | */ | |
2370 | struct kmem_cache * | |
2371 | __kmem_cache_create (const char *name, size_t size, size_t align, | |
2372 | unsigned long flags, void (*ctor)(void *)) | |
2373 | { | |
2374 | size_t left_over, slab_size, ralign; | |
2375 | struct kmem_cache *cachep = NULL; | |
2376 | gfp_t gfp; | |
2377 | ||
2378 | #if DEBUG | |
2379 | #if FORCED_DEBUG | |
2380 | /* | |
2381 | * Enable redzoning and last user accounting, except for caches with | |
2382 | * large objects, if the increased size would increase the object size | |
2383 | * above the next power of two: caches with object sizes just above a | |
2384 | * power of two have a significant amount of internal fragmentation. | |
2385 | */ | |
2386 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + | |
2387 | 2 * sizeof(unsigned long long))) | |
2388 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; | |
2389 | if (!(flags & SLAB_DESTROY_BY_RCU)) | |
2390 | flags |= SLAB_POISON; | |
2391 | #endif | |
2392 | if (flags & SLAB_DESTROY_BY_RCU) | |
2393 | BUG_ON(flags & SLAB_POISON); | |
2394 | #endif | |
2395 | /* | |
2396 | * Always checks flags, a caller might be expecting debug support which | |
2397 | * isn't available. | |
2398 | */ | |
2399 | BUG_ON(flags & ~CREATE_MASK); | |
2400 | ||
2401 | /* | |
2402 | * Check that size is in terms of words. This is needed to avoid | |
2403 | * unaligned accesses for some archs when redzoning is used, and makes | |
2404 | * sure any on-slab bufctl's are also correctly aligned. | |
2405 | */ | |
2406 | if (size & (BYTES_PER_WORD - 1)) { | |
2407 | size += (BYTES_PER_WORD - 1); | |
2408 | size &= ~(BYTES_PER_WORD - 1); | |
2409 | } | |
2410 | ||
2411 | /* calculate the final buffer alignment: */ | |
2412 | ||
2413 | /* 1) arch recommendation: can be overridden for debug */ | |
2414 | if (flags & SLAB_HWCACHE_ALIGN) { | |
2415 | /* | |
2416 | * Default alignment: as specified by the arch code. Except if | |
2417 | * an object is really small, then squeeze multiple objects into | |
2418 | * one cacheline. | |
2419 | */ | |
2420 | ralign = cache_line_size(); | |
2421 | while (size <= ralign / 2) | |
2422 | ralign /= 2; | |
2423 | } else { | |
2424 | ralign = BYTES_PER_WORD; | |
2425 | } | |
2426 | ||
2427 | /* | |
2428 | * Redzoning and user store require word alignment or possibly larger. | |
2429 | * Note this will be overridden by architecture or caller mandated | |
2430 | * alignment if either is greater than BYTES_PER_WORD. | |
2431 | */ | |
2432 | if (flags & SLAB_STORE_USER) | |
2433 | ralign = BYTES_PER_WORD; | |
2434 | ||
2435 | if (flags & SLAB_RED_ZONE) { | |
2436 | ralign = REDZONE_ALIGN; | |
2437 | /* If redzoning, ensure that the second redzone is suitably | |
2438 | * aligned, by adjusting the object size accordingly. */ | |
2439 | size += REDZONE_ALIGN - 1; | |
2440 | size &= ~(REDZONE_ALIGN - 1); | |
2441 | } | |
2442 | ||
2443 | /* 2) arch mandated alignment */ | |
2444 | if (ralign < ARCH_SLAB_MINALIGN) { | |
2445 | ralign = ARCH_SLAB_MINALIGN; | |
2446 | } | |
2447 | /* 3) caller mandated alignment */ | |
2448 | if (ralign < align) { | |
2449 | ralign = align; | |
2450 | } | |
2451 | /* disable debug if necessary */ | |
2452 | if (ralign > __alignof__(unsigned long long)) | |
2453 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); | |
2454 | /* | |
2455 | * 4) Store it. | |
2456 | */ | |
2457 | align = ralign; | |
2458 | ||
2459 | if (slab_is_available()) | |
2460 | gfp = GFP_KERNEL; | |
2461 | else | |
2462 | gfp = GFP_NOWAIT; | |
2463 | ||
2464 | /* Get cache's description obj. */ | |
2465 | cachep = kmem_cache_zalloc(&cache_cache, gfp); | |
2466 | if (!cachep) | |
2467 | return NULL; | |
2468 | ||
2469 | cachep->nodelists = (struct kmem_list3 **)&cachep->array[nr_cpu_ids]; | |
2470 | cachep->object_size = size; | |
2471 | cachep->align = align; | |
2472 | #if DEBUG | |
2473 | ||
2474 | /* | |
2475 | * Both debugging options require word-alignment which is calculated | |
2476 | * into align above. | |
2477 | */ | |
2478 | if (flags & SLAB_RED_ZONE) { | |
2479 | /* add space for red zone words */ | |
2480 | cachep->obj_offset += sizeof(unsigned long long); | |
2481 | size += 2 * sizeof(unsigned long long); | |
2482 | } | |
2483 | if (flags & SLAB_STORE_USER) { | |
2484 | /* user store requires one word storage behind the end of | |
2485 | * the real object. But if the second red zone needs to be | |
2486 | * aligned to 64 bits, we must allow that much space. | |
2487 | */ | |
2488 | if (flags & SLAB_RED_ZONE) | |
2489 | size += REDZONE_ALIGN; | |
2490 | else | |
2491 | size += BYTES_PER_WORD; | |
2492 | } | |
2493 | #if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC) | |
2494 | if (size >= malloc_sizes[INDEX_L3 + 1].cs_size | |
2495 | && cachep->object_size > cache_line_size() && ALIGN(size, align) < PAGE_SIZE) { | |
2496 | cachep->obj_offset += PAGE_SIZE - ALIGN(size, align); | |
2497 | size = PAGE_SIZE; | |
2498 | } | |
2499 | #endif | |
2500 | #endif | |
2501 | ||
2502 | /* | |
2503 | * Determine if the slab management is 'on' or 'off' slab. | |
2504 | * (bootstrapping cannot cope with offslab caches so don't do | |
2505 | * it too early on. Always use on-slab management when | |
2506 | * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak) | |
2507 | */ | |
2508 | if ((size >= (PAGE_SIZE >> 3)) && !slab_early_init && | |
2509 | !(flags & SLAB_NOLEAKTRACE)) | |
2510 | /* | |
2511 | * Size is large, assume best to place the slab management obj | |
2512 | * off-slab (should allow better packing of objs). | |
2513 | */ | |
2514 | flags |= CFLGS_OFF_SLAB; | |
2515 | ||
2516 | size = ALIGN(size, align); | |
2517 | ||
2518 | left_over = calculate_slab_order(cachep, size, align, flags); | |
2519 | ||
2520 | if (!cachep->num) { | |
2521 | printk(KERN_ERR | |
2522 | "kmem_cache_create: couldn't create cache %s.\n", name); | |
2523 | kmem_cache_free(&cache_cache, cachep); | |
2524 | return NULL; | |
2525 | } | |
2526 | slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) | |
2527 | + sizeof(struct slab), align); | |
2528 | ||
2529 | /* | |
2530 | * If the slab has been placed off-slab, and we have enough space then | |
2531 | * move it on-slab. This is at the expense of any extra colouring. | |
2532 | */ | |
2533 | if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) { | |
2534 | flags &= ~CFLGS_OFF_SLAB; | |
2535 | left_over -= slab_size; | |
2536 | } | |
2537 | ||
2538 | if (flags & CFLGS_OFF_SLAB) { | |
2539 | /* really off slab. No need for manual alignment */ | |
2540 | slab_size = | |
2541 | cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); | |
2542 | ||
2543 | #ifdef CONFIG_PAGE_POISONING | |
2544 | /* If we're going to use the generic kernel_map_pages() | |
2545 | * poisoning, then it's going to smash the contents of | |
2546 | * the redzone and userword anyhow, so switch them off. | |
2547 | */ | |
2548 | if (size % PAGE_SIZE == 0 && flags & SLAB_POISON) | |
2549 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); | |
2550 | #endif | |
2551 | } | |
2552 | ||
2553 | cachep->colour_off = cache_line_size(); | |
2554 | /* Offset must be a multiple of the alignment. */ | |
2555 | if (cachep->colour_off < align) | |
2556 | cachep->colour_off = align; | |
2557 | cachep->colour = left_over / cachep->colour_off; | |
2558 | cachep->slab_size = slab_size; | |
2559 | cachep->flags = flags; | |
2560 | cachep->allocflags = 0; | |
2561 | if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA)) | |
2562 | cachep->allocflags |= GFP_DMA; | |
2563 | cachep->size = size; | |
2564 | cachep->reciprocal_buffer_size = reciprocal_value(size); | |
2565 | ||
2566 | if (flags & CFLGS_OFF_SLAB) { | |
2567 | cachep->slabp_cache = kmem_find_general_cachep(slab_size, 0u); | |
2568 | /* | |
2569 | * This is a possibility for one of the malloc_sizes caches. | |
2570 | * But since we go off slab only for object size greater than | |
2571 | * PAGE_SIZE/8, and malloc_sizes gets created in ascending order, | |
2572 | * this should not happen at all. | |
2573 | * But leave a BUG_ON for some lucky dude. | |
2574 | */ | |
2575 | BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); | |
2576 | } | |
2577 | cachep->ctor = ctor; | |
2578 | cachep->name = name; | |
2579 | ||
2580 | if (setup_cpu_cache(cachep, gfp)) { | |
2581 | __kmem_cache_destroy(cachep); | |
2582 | return NULL; | |
2583 | } | |
2584 | ||
2585 | if (flags & SLAB_DEBUG_OBJECTS) { | |
2586 | /* | |
2587 | * Would deadlock through slab_destroy()->call_rcu()-> | |
2588 | * debug_object_activate()->kmem_cache_alloc(). | |
2589 | */ | |
2590 | WARN_ON_ONCE(flags & SLAB_DESTROY_BY_RCU); | |
2591 | ||
2592 | slab_set_debugobj_lock_classes(cachep); | |
2593 | } | |
2594 | ||
2595 | /* cache setup completed, link it into the list */ | |
2596 | list_add(&cachep->list, &slab_caches); | |
2597 | return cachep; | |
2598 | } | |
2599 | ||
2600 | #if DEBUG | |
2601 | static void check_irq_off(void) | |
2602 | { | |
2603 | BUG_ON(!irqs_disabled()); | |
2604 | } | |
2605 | ||
2606 | static void check_irq_on(void) | |
2607 | { | |
2608 | BUG_ON(irqs_disabled()); | |
2609 | } | |
2610 | ||
2611 | static void check_spinlock_acquired(struct kmem_cache *cachep) | |
2612 | { | |
2613 | #ifdef CONFIG_SMP | |
2614 | check_irq_off(); | |
2615 | assert_spin_locked(&cachep->nodelists[numa_mem_id()]->list_lock); | |
2616 | #endif | |
2617 | } | |
2618 | ||
2619 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) | |
2620 | { | |
2621 | #ifdef CONFIG_SMP | |
2622 | check_irq_off(); | |
2623 | assert_spin_locked(&cachep->nodelists[node]->list_lock); | |
2624 | #endif | |
2625 | } | |
2626 | ||
2627 | #else | |
2628 | #define check_irq_off() do { } while(0) | |
2629 | #define check_irq_on() do { } while(0) | |
2630 | #define check_spinlock_acquired(x) do { } while(0) | |
2631 | #define check_spinlock_acquired_node(x, y) do { } while(0) | |
2632 | #endif | |
2633 | ||
2634 | static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, | |
2635 | struct array_cache *ac, | |
2636 | int force, int node); | |
2637 | ||
2638 | static void do_drain(void *arg) | |
2639 | { | |
2640 | struct kmem_cache *cachep = arg; | |
2641 | struct array_cache *ac; | |
2642 | int node = numa_mem_id(); | |
2643 | ||
2644 | check_irq_off(); | |
2645 | ac = cpu_cache_get(cachep); | |
2646 | spin_lock(&cachep->nodelists[node]->list_lock); | |
2647 | free_block(cachep, ac->entry, ac->avail, node); | |
2648 | spin_unlock(&cachep->nodelists[node]->list_lock); | |
2649 | ac->avail = 0; | |
2650 | } | |
2651 | ||
2652 | static void drain_cpu_caches(struct kmem_cache *cachep) | |
2653 | { | |
2654 | struct kmem_list3 *l3; | |
2655 | int node; | |
2656 | ||
2657 | on_each_cpu(do_drain, cachep, 1); | |
2658 | check_irq_on(); | |
2659 | for_each_online_node(node) { | |
2660 | l3 = cachep->nodelists[node]; | |
2661 | if (l3 && l3->alien) | |
2662 | drain_alien_cache(cachep, l3->alien); | |
2663 | } | |
2664 | ||
2665 | for_each_online_node(node) { | |
2666 | l3 = cachep->nodelists[node]; | |
2667 | if (l3) | |
2668 | drain_array(cachep, l3, l3->shared, 1, node); | |
2669 | } | |
2670 | } | |
2671 | ||
2672 | /* | |
2673 | * Remove slabs from the list of free slabs. | |
2674 | * Specify the number of slabs to drain in tofree. | |
2675 | * | |
2676 | * Returns the actual number of slabs released. | |
2677 | */ | |
2678 | static int drain_freelist(struct kmem_cache *cache, | |
2679 | struct kmem_list3 *l3, int tofree) | |
2680 | { | |
2681 | struct list_head *p; | |
2682 | int nr_freed; | |
2683 | struct slab *slabp; | |
2684 | ||
2685 | nr_freed = 0; | |
2686 | while (nr_freed < tofree && !list_empty(&l3->slabs_free)) { | |
2687 | ||
2688 | spin_lock_irq(&l3->list_lock); | |
2689 | p = l3->slabs_free.prev; | |
2690 | if (p == &l3->slabs_free) { | |
2691 | spin_unlock_irq(&l3->list_lock); | |
2692 | goto out; | |
2693 | } | |
2694 | ||
2695 | slabp = list_entry(p, struct slab, list); | |
2696 | #if DEBUG | |
2697 | BUG_ON(slabp->inuse); | |
2698 | #endif | |
2699 | list_del(&slabp->list); | |
2700 | /* | |
2701 | * Safe to drop the lock. The slab is no longer linked | |
2702 | * to the cache. | |
2703 | */ | |
2704 | l3->free_objects -= cache->num; | |
2705 | spin_unlock_irq(&l3->list_lock); | |
2706 | slab_destroy(cache, slabp); | |
2707 | nr_freed++; | |
2708 | } | |
2709 | out: | |
2710 | return nr_freed; | |
2711 | } | |
2712 | ||
2713 | /* Called with slab_mutex held to protect against cpu hotplug */ | |
2714 | static int __cache_shrink(struct kmem_cache *cachep) | |
2715 | { | |
2716 | int ret = 0, i = 0; | |
2717 | struct kmem_list3 *l3; | |
2718 | ||
2719 | drain_cpu_caches(cachep); | |
2720 | ||
2721 | check_irq_on(); | |
2722 | for_each_online_node(i) { | |
2723 | l3 = cachep->nodelists[i]; | |
2724 | if (!l3) | |
2725 | continue; | |
2726 | ||
2727 | drain_freelist(cachep, l3, l3->free_objects); | |
2728 | ||
2729 | ret += !list_empty(&l3->slabs_full) || | |
2730 | !list_empty(&l3->slabs_partial); | |
2731 | } | |
2732 | return (ret ? 1 : 0); | |
2733 | } | |
2734 | ||
2735 | /** | |
2736 | * kmem_cache_shrink - Shrink a cache. | |
2737 | * @cachep: The cache to shrink. | |
2738 | * | |
2739 | * Releases as many slabs as possible for a cache. | |
2740 | * To help debugging, a zero exit status indicates all slabs were released. | |
2741 | */ | |
2742 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
2743 | { | |
2744 | int ret; | |
2745 | BUG_ON(!cachep || in_interrupt()); | |
2746 | ||
2747 | get_online_cpus(); | |
2748 | mutex_lock(&slab_mutex); | |
2749 | ret = __cache_shrink(cachep); | |
2750 | mutex_unlock(&slab_mutex); | |
2751 | put_online_cpus(); | |
2752 | return ret; | |
2753 | } | |
2754 | EXPORT_SYMBOL(kmem_cache_shrink); | |
2755 | ||
2756 | /** | |
2757 | * kmem_cache_destroy - delete a cache | |
2758 | * @cachep: the cache to destroy | |
2759 | * | |
2760 | * Remove a &struct kmem_cache object from the slab cache. | |
2761 | * | |
2762 | * It is expected this function will be called by a module when it is | |
2763 | * unloaded. This will remove the cache completely, and avoid a duplicate | |
2764 | * cache being allocated each time a module is loaded and unloaded, if the | |
2765 | * module doesn't have persistent in-kernel storage across loads and unloads. | |
2766 | * | |
2767 | * The cache must be empty before calling this function. | |
2768 | * | |
2769 | * The caller must guarantee that no one will allocate memory from the cache | |
2770 | * during the kmem_cache_destroy(). | |
2771 | */ | |
2772 | void kmem_cache_destroy(struct kmem_cache *cachep) | |
2773 | { | |
2774 | BUG_ON(!cachep || in_interrupt()); | |
2775 | ||
2776 | /* Find the cache in the chain of caches. */ | |
2777 | get_online_cpus(); | |
2778 | mutex_lock(&slab_mutex); | |
2779 | /* | |
2780 | * the chain is never empty, cache_cache is never destroyed | |
2781 | */ | |
2782 | list_del(&cachep->list); | |
2783 | if (__cache_shrink(cachep)) { | |
2784 | slab_error(cachep, "Can't free all objects"); | |
2785 | list_add(&cachep->list, &slab_caches); | |
2786 | mutex_unlock(&slab_mutex); | |
2787 | put_online_cpus(); | |
2788 | return; | |
2789 | } | |
2790 | ||
2791 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) | |
2792 | rcu_barrier(); | |
2793 | ||
2794 | __kmem_cache_destroy(cachep); | |
2795 | mutex_unlock(&slab_mutex); | |
2796 | put_online_cpus(); | |
2797 | } | |
2798 | EXPORT_SYMBOL(kmem_cache_destroy); | |
2799 | ||
2800 | /* | |
2801 | * Get the memory for a slab management obj. | |
2802 | * For a slab cache when the slab descriptor is off-slab, slab descriptors | |
2803 | * always come from malloc_sizes caches. The slab descriptor cannot | |
2804 | * come from the same cache which is getting created because, | |
2805 | * when we are searching for an appropriate cache for these | |
2806 | * descriptors in kmem_cache_create, we search through the malloc_sizes array. | |
2807 | * If we are creating a malloc_sizes cache here it would not be visible to | |
2808 | * kmem_find_general_cachep till the initialization is complete. | |
2809 | * Hence we cannot have slabp_cache same as the original cache. | |
2810 | */ | |
2811 | static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, | |
2812 | int colour_off, gfp_t local_flags, | |
2813 | int nodeid) | |
2814 | { | |
2815 | struct slab *slabp; | |
2816 | ||
2817 | if (OFF_SLAB(cachep)) { | |
2818 | /* Slab management obj is off-slab. */ | |
2819 | slabp = kmem_cache_alloc_node(cachep->slabp_cache, | |
2820 | local_flags, nodeid); | |
2821 | /* | |
2822 | * If the first object in the slab is leaked (it's allocated | |
2823 | * but no one has a reference to it), we want to make sure | |
2824 | * kmemleak does not treat the ->s_mem pointer as a reference | |
2825 | * to the object. Otherwise we will not report the leak. | |
2826 | */ | |
2827 | kmemleak_scan_area(&slabp->list, sizeof(struct list_head), | |
2828 | local_flags); | |
2829 | if (!slabp) | |
2830 | return NULL; | |
2831 | } else { | |
2832 | slabp = objp + colour_off; | |
2833 | colour_off += cachep->slab_size; | |
2834 | } | |
2835 | slabp->inuse = 0; | |
2836 | slabp->colouroff = colour_off; | |
2837 | slabp->s_mem = objp + colour_off; | |
2838 | slabp->nodeid = nodeid; | |
2839 | slabp->free = 0; | |
2840 | return slabp; | |
2841 | } | |
2842 | ||
2843 | static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) | |
2844 | { | |
2845 | return (kmem_bufctl_t *) (slabp + 1); | |
2846 | } | |
2847 | ||
2848 | static void cache_init_objs(struct kmem_cache *cachep, | |
2849 | struct slab *slabp) | |
2850 | { | |
2851 | int i; | |
2852 | ||
2853 | for (i = 0; i < cachep->num; i++) { | |
2854 | void *objp = index_to_obj(cachep, slabp, i); | |
2855 | #if DEBUG | |
2856 | /* need to poison the objs? */ | |
2857 | if (cachep->flags & SLAB_POISON) | |
2858 | poison_obj(cachep, objp, POISON_FREE); | |
2859 | if (cachep->flags & SLAB_STORE_USER) | |
2860 | *dbg_userword(cachep, objp) = NULL; | |
2861 | ||
2862 | if (cachep->flags & SLAB_RED_ZONE) { | |
2863 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2864 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2865 | } | |
2866 | /* | |
2867 | * Constructors are not allowed to allocate memory from the same | |
2868 | * cache which they are a constructor for. Otherwise, deadlock. | |
2869 | * They must also be threaded. | |
2870 | */ | |
2871 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) | |
2872 | cachep->ctor(objp + obj_offset(cachep)); | |
2873 | ||
2874 | if (cachep->flags & SLAB_RED_ZONE) { | |
2875 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
2876 | slab_error(cachep, "constructor overwrote the" | |
2877 | " end of an object"); | |
2878 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
2879 | slab_error(cachep, "constructor overwrote the" | |
2880 | " start of an object"); | |
2881 | } | |
2882 | if ((cachep->size % PAGE_SIZE) == 0 && | |
2883 | OFF_SLAB(cachep) && cachep->flags & SLAB_POISON) | |
2884 | kernel_map_pages(virt_to_page(objp), | |
2885 | cachep->size / PAGE_SIZE, 0); | |
2886 | #else | |
2887 | if (cachep->ctor) | |
2888 | cachep->ctor(objp); | |
2889 | #endif | |
2890 | slab_bufctl(slabp)[i] = i + 1; | |
2891 | } | |
2892 | slab_bufctl(slabp)[i - 1] = BUFCTL_END; | |
2893 | } | |
2894 | ||
2895 | static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) | |
2896 | { | |
2897 | if (CONFIG_ZONE_DMA_FLAG) { | |
2898 | if (flags & GFP_DMA) | |
2899 | BUG_ON(!(cachep->allocflags & GFP_DMA)); | |
2900 | else | |
2901 | BUG_ON(cachep->allocflags & GFP_DMA); | |
2902 | } | |
2903 | } | |
2904 | ||
2905 | static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, | |
2906 | int nodeid) | |
2907 | { | |
2908 | void *objp = index_to_obj(cachep, slabp, slabp->free); | |
2909 | kmem_bufctl_t next; | |
2910 | ||
2911 | slabp->inuse++; | |
2912 | next = slab_bufctl(slabp)[slabp->free]; | |
2913 | #if DEBUG | |
2914 | slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE; | |
2915 | WARN_ON(slabp->nodeid != nodeid); | |
2916 | #endif | |
2917 | slabp->free = next; | |
2918 | ||
2919 | return objp; | |
2920 | } | |
2921 | ||
2922 | static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, | |
2923 | void *objp, int nodeid) | |
2924 | { | |
2925 | unsigned int objnr = obj_to_index(cachep, slabp, objp); | |
2926 | ||
2927 | #if DEBUG | |
2928 | /* Verify that the slab belongs to the intended node */ | |
2929 | WARN_ON(slabp->nodeid != nodeid); | |
2930 | ||
2931 | if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) { | |
2932 | printk(KERN_ERR "slab: double free detected in cache " | |
2933 | "'%s', objp %p\n", cachep->name, objp); | |
2934 | BUG(); | |
2935 | } | |
2936 | #endif | |
2937 | slab_bufctl(slabp)[objnr] = slabp->free; | |
2938 | slabp->free = objnr; | |
2939 | slabp->inuse--; | |
2940 | } | |
2941 | ||
2942 | /* | |
2943 | * Map pages beginning at addr to the given cache and slab. This is required | |
2944 | * for the slab allocator to be able to lookup the cache and slab of a | |
2945 | * virtual address for kfree, ksize, and slab debugging. | |
2946 | */ | |
2947 | static void slab_map_pages(struct kmem_cache *cache, struct slab *slab, | |
2948 | void *addr) | |
2949 | { | |
2950 | int nr_pages; | |
2951 | struct page *page; | |
2952 | ||
2953 | page = virt_to_page(addr); | |
2954 | ||
2955 | nr_pages = 1; | |
2956 | if (likely(!PageCompound(page))) | |
2957 | nr_pages <<= cache->gfporder; | |
2958 | ||
2959 | do { | |
2960 | page->slab_cache = cache; | |
2961 | page->slab_page = slab; | |
2962 | page++; | |
2963 | } while (--nr_pages); | |
2964 | } | |
2965 | ||
2966 | /* | |
2967 | * Grow (by 1) the number of slabs within a cache. This is called by | |
2968 | * kmem_cache_alloc() when there are no active objs left in a cache. | |
2969 | */ | |
2970 | static int cache_grow(struct kmem_cache *cachep, | |
2971 | gfp_t flags, int nodeid, void *objp) | |
2972 | { | |
2973 | struct slab *slabp; | |
2974 | size_t offset; | |
2975 | gfp_t local_flags; | |
2976 | struct kmem_list3 *l3; | |
2977 | ||
2978 | /* | |
2979 | * Be lazy and only check for valid flags here, keeping it out of the | |
2980 | * critical path in kmem_cache_alloc(). | |
2981 | */ | |
2982 | BUG_ON(flags & GFP_SLAB_BUG_MASK); | |
2983 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); | |
2984 | ||
2985 | /* Take the l3 list lock to change the colour_next on this node */ | |
2986 | check_irq_off(); | |
2987 | l3 = cachep->nodelists[nodeid]; | |
2988 | spin_lock(&l3->list_lock); | |
2989 | ||
2990 | /* Get colour for the slab, and cal the next value. */ | |
2991 | offset = l3->colour_next; | |
2992 | l3->colour_next++; | |
2993 | if (l3->colour_next >= cachep->colour) | |
2994 | l3->colour_next = 0; | |
2995 | spin_unlock(&l3->list_lock); | |
2996 | ||
2997 | offset *= cachep->colour_off; | |
2998 | ||
2999 | if (local_flags & __GFP_WAIT) | |
3000 | local_irq_enable(); | |
3001 | ||
3002 | /* | |
3003 | * The test for missing atomic flag is performed here, rather than | |
3004 | * the more obvious place, simply to reduce the critical path length | |
3005 | * in kmem_cache_alloc(). If a caller is seriously mis-behaving they | |
3006 | * will eventually be caught here (where it matters). | |
3007 | */ | |
3008 | kmem_flagcheck(cachep, flags); | |
3009 | ||
3010 | /* | |
3011 | * Get mem for the objs. Attempt to allocate a physical page from | |
3012 | * 'nodeid'. | |
3013 | */ | |
3014 | if (!objp) | |
3015 | objp = kmem_getpages(cachep, local_flags, nodeid); | |
3016 | if (!objp) | |
3017 | goto failed; | |
3018 | ||
3019 | /* Get slab management. */ | |
3020 | slabp = alloc_slabmgmt(cachep, objp, offset, | |
3021 | local_flags & ~GFP_CONSTRAINT_MASK, nodeid); | |
3022 | if (!slabp) | |
3023 | goto opps1; | |
3024 | ||
3025 | slab_map_pages(cachep, slabp, objp); | |
3026 | ||
3027 | cache_init_objs(cachep, slabp); | |
3028 | ||
3029 | if (local_flags & __GFP_WAIT) | |
3030 | local_irq_disable(); | |
3031 | check_irq_off(); | |
3032 | spin_lock(&l3->list_lock); | |
3033 | ||
3034 | /* Make slab active. */ | |
3035 | list_add_tail(&slabp->list, &(l3->slabs_free)); | |
3036 | STATS_INC_GROWN(cachep); | |
3037 | l3->free_objects += cachep->num; | |
3038 | spin_unlock(&l3->list_lock); | |
3039 | return 1; | |
3040 | opps1: | |
3041 | kmem_freepages(cachep, objp); | |
3042 | failed: | |
3043 | if (local_flags & __GFP_WAIT) | |
3044 | local_irq_disable(); | |
3045 | return 0; | |
3046 | } | |
3047 | ||
3048 | #if DEBUG | |
3049 | ||
3050 | /* | |
3051 | * Perform extra freeing checks: | |
3052 | * - detect bad pointers. | |
3053 | * - POISON/RED_ZONE checking | |
3054 | */ | |
3055 | static void kfree_debugcheck(const void *objp) | |
3056 | { | |
3057 | if (!virt_addr_valid(objp)) { | |
3058 | printk(KERN_ERR "kfree_debugcheck: out of range ptr %lxh.\n", | |
3059 | (unsigned long)objp); | |
3060 | BUG(); | |
3061 | } | |
3062 | } | |
3063 | ||
3064 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) | |
3065 | { | |
3066 | unsigned long long redzone1, redzone2; | |
3067 | ||
3068 | redzone1 = *dbg_redzone1(cache, obj); | |
3069 | redzone2 = *dbg_redzone2(cache, obj); | |
3070 | ||
3071 | /* | |
3072 | * Redzone is ok. | |
3073 | */ | |
3074 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) | |
3075 | return; | |
3076 | ||
3077 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) | |
3078 | slab_error(cache, "double free detected"); | |
3079 | else | |
3080 | slab_error(cache, "memory outside object was overwritten"); | |
3081 | ||
3082 | printk(KERN_ERR "%p: redzone 1:0x%llx, redzone 2:0x%llx.\n", | |
3083 | obj, redzone1, redzone2); | |
3084 | } | |
3085 | ||
3086 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, | |
3087 | unsigned long caller) | |
3088 | { | |
3089 | struct page *page; | |
3090 | unsigned int objnr; | |
3091 | struct slab *slabp; | |
3092 | ||
3093 | BUG_ON(virt_to_cache(objp) != cachep); | |
3094 | ||
3095 | objp -= obj_offset(cachep); | |
3096 | kfree_debugcheck(objp); | |
3097 | page = virt_to_head_page(objp); | |
3098 | ||
3099 | slabp = page->slab_page; | |
3100 | ||
3101 | if (cachep->flags & SLAB_RED_ZONE) { | |
3102 | verify_redzone_free(cachep, objp); | |
3103 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
3104 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
3105 | } | |
3106 | if (cachep->flags & SLAB_STORE_USER) | |
3107 | *dbg_userword(cachep, objp) = (void *)caller; | |
3108 | ||
3109 | objnr = obj_to_index(cachep, slabp, objp); | |
3110 | ||
3111 | BUG_ON(objnr >= cachep->num); | |
3112 | BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); | |
3113 | ||
3114 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
3115 | slab_bufctl(slabp)[objnr] = BUFCTL_FREE; | |
3116 | #endif | |
3117 | if (cachep->flags & SLAB_POISON) { | |
3118 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
3119 | if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) { | |
3120 | store_stackinfo(cachep, objp, caller); | |
3121 | kernel_map_pages(virt_to_page(objp), | |
3122 | cachep->size / PAGE_SIZE, 0); | |
3123 | } else { | |
3124 | poison_obj(cachep, objp, POISON_FREE); | |
3125 | } | |
3126 | #else | |
3127 | poison_obj(cachep, objp, POISON_FREE); | |
3128 | #endif | |
3129 | } | |
3130 | return objp; | |
3131 | } | |
3132 | ||
3133 | static void check_slabp(struct kmem_cache *cachep, struct slab *slabp) | |
3134 | { | |
3135 | kmem_bufctl_t i; | |
3136 | int entries = 0; | |
3137 | ||
3138 | /* Check slab's freelist to see if this obj is there. */ | |
3139 | for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) { | |
3140 | entries++; | |
3141 | if (entries > cachep->num || i >= cachep->num) | |
3142 | goto bad; | |
3143 | } | |
3144 | if (entries != cachep->num - slabp->inuse) { | |
3145 | bad: | |
3146 | printk(KERN_ERR "slab: Internal list corruption detected in " | |
3147 | "cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n", | |
3148 | cachep->name, cachep->num, slabp, slabp->inuse, | |
3149 | print_tainted()); | |
3150 | print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp, | |
3151 | sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t), | |
3152 | 1); | |
3153 | BUG(); | |
3154 | } | |
3155 | } | |
3156 | #else | |
3157 | #define kfree_debugcheck(x) do { } while(0) | |
3158 | #define cache_free_debugcheck(x,objp,z) (objp) | |
3159 | #define check_slabp(x,y) do { } while(0) | |
3160 | #endif | |
3161 | ||
3162 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags, | |
3163 | bool force_refill) | |
3164 | { | |
3165 | int batchcount; | |
3166 | struct kmem_list3 *l3; | |
3167 | struct array_cache *ac; | |
3168 | int node; | |
3169 | ||
3170 | check_irq_off(); | |
3171 | node = numa_mem_id(); | |
3172 | if (unlikely(force_refill)) | |
3173 | goto force_grow; | |
3174 | retry: | |
3175 | ac = cpu_cache_get(cachep); | |
3176 | batchcount = ac->batchcount; | |
3177 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { | |
3178 | /* | |
3179 | * If there was little recent activity on this cache, then | |
3180 | * perform only a partial refill. Otherwise we could generate | |
3181 | * refill bouncing. | |
3182 | */ | |
3183 | batchcount = BATCHREFILL_LIMIT; | |
3184 | } | |
3185 | l3 = cachep->nodelists[node]; | |
3186 | ||
3187 | BUG_ON(ac->avail > 0 || !l3); | |
3188 | spin_lock(&l3->list_lock); | |
3189 | ||
3190 | /* See if we can refill from the shared array */ | |
3191 | if (l3->shared && transfer_objects(ac, l3->shared, batchcount)) { | |
3192 | l3->shared->touched = 1; | |
3193 | goto alloc_done; | |
3194 | } | |
3195 | ||
3196 | while (batchcount > 0) { | |
3197 | struct list_head *entry; | |
3198 | struct slab *slabp; | |
3199 | /* Get slab alloc is to come from. */ | |
3200 | entry = l3->slabs_partial.next; | |
3201 | if (entry == &l3->slabs_partial) { | |
3202 | l3->free_touched = 1; | |
3203 | entry = l3->slabs_free.next; | |
3204 | if (entry == &l3->slabs_free) | |
3205 | goto must_grow; | |
3206 | } | |
3207 | ||
3208 | slabp = list_entry(entry, struct slab, list); | |
3209 | check_slabp(cachep, slabp); | |
3210 | check_spinlock_acquired(cachep); | |
3211 | ||
3212 | /* | |
3213 | * The slab was either on partial or free list so | |
3214 | * there must be at least one object available for | |
3215 | * allocation. | |
3216 | */ | |
3217 | BUG_ON(slabp->inuse >= cachep->num); | |
3218 | ||
3219 | while (slabp->inuse < cachep->num && batchcount--) { | |
3220 | STATS_INC_ALLOCED(cachep); | |
3221 | STATS_INC_ACTIVE(cachep); | |
3222 | STATS_SET_HIGH(cachep); | |
3223 | ||
3224 | ac_put_obj(cachep, ac, slab_get_obj(cachep, slabp, | |
3225 | node)); | |
3226 | } | |
3227 | check_slabp(cachep, slabp); | |
3228 | ||
3229 | /* move slabp to correct slabp list: */ | |
3230 | list_del(&slabp->list); | |
3231 | if (slabp->free == BUFCTL_END) | |
3232 | list_add(&slabp->list, &l3->slabs_full); | |
3233 | else | |
3234 | list_add(&slabp->list, &l3->slabs_partial); | |
3235 | } | |
3236 | ||
3237 | must_grow: | |
3238 | l3->free_objects -= ac->avail; | |
3239 | alloc_done: | |
3240 | spin_unlock(&l3->list_lock); | |
3241 | ||
3242 | if (unlikely(!ac->avail)) { | |
3243 | int x; | |
3244 | force_grow: | |
3245 | x = cache_grow(cachep, flags | GFP_THISNODE, node, NULL); | |
3246 | ||
3247 | /* cache_grow can reenable interrupts, then ac could change. */ | |
3248 | ac = cpu_cache_get(cachep); | |
3249 | ||
3250 | /* no objects in sight? abort */ | |
3251 | if (!x && (ac->avail == 0 || force_refill)) | |
3252 | return NULL; | |
3253 | ||
3254 | if (!ac->avail) /* objects refilled by interrupt? */ | |
3255 | goto retry; | |
3256 | } | |
3257 | ac->touched = 1; | |
3258 | ||
3259 | return ac_get_obj(cachep, ac, flags, force_refill); | |
3260 | } | |
3261 | ||
3262 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, | |
3263 | gfp_t flags) | |
3264 | { | |
3265 | might_sleep_if(flags & __GFP_WAIT); | |
3266 | #if DEBUG | |
3267 | kmem_flagcheck(cachep, flags); | |
3268 | #endif | |
3269 | } | |
3270 | ||
3271 | #if DEBUG | |
3272 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, | |
3273 | gfp_t flags, void *objp, unsigned long caller) | |
3274 | { | |
3275 | if (!objp) | |
3276 | return objp; | |
3277 | if (cachep->flags & SLAB_POISON) { | |
3278 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
3279 | if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) | |
3280 | kernel_map_pages(virt_to_page(objp), | |
3281 | cachep->size / PAGE_SIZE, 1); | |
3282 | else | |
3283 | check_poison_obj(cachep, objp); | |
3284 | #else | |
3285 | check_poison_obj(cachep, objp); | |
3286 | #endif | |
3287 | poison_obj(cachep, objp, POISON_INUSE); | |
3288 | } | |
3289 | if (cachep->flags & SLAB_STORE_USER) | |
3290 | *dbg_userword(cachep, objp) = (void *)caller; | |
3291 | ||
3292 | if (cachep->flags & SLAB_RED_ZONE) { | |
3293 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || | |
3294 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { | |
3295 | slab_error(cachep, "double free, or memory outside" | |
3296 | " object was overwritten"); | |
3297 | printk(KERN_ERR | |
3298 | "%p: redzone 1:0x%llx, redzone 2:0x%llx\n", | |
3299 | objp, *dbg_redzone1(cachep, objp), | |
3300 | *dbg_redzone2(cachep, objp)); | |
3301 | } | |
3302 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; | |
3303 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; | |
3304 | } | |
3305 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
3306 | { | |
3307 | struct slab *slabp; | |
3308 | unsigned objnr; | |
3309 | ||
3310 | slabp = virt_to_head_page(objp)->slab_page; | |
3311 | objnr = (unsigned)(objp - slabp->s_mem) / cachep->size; | |
3312 | slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE; | |
3313 | } | |
3314 | #endif | |
3315 | objp += obj_offset(cachep); | |
3316 | if (cachep->ctor && cachep->flags & SLAB_POISON) | |
3317 | cachep->ctor(objp); | |
3318 | if (ARCH_SLAB_MINALIGN && | |
3319 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { | |
3320 | printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", | |
3321 | objp, (int)ARCH_SLAB_MINALIGN); | |
3322 | } | |
3323 | return objp; | |
3324 | } | |
3325 | #else | |
3326 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) | |
3327 | #endif | |
3328 | ||
3329 | static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) | |
3330 | { | |
3331 | if (cachep == &cache_cache) | |
3332 | return false; | |
3333 | ||
3334 | return should_failslab(cachep->object_size, flags, cachep->flags); | |
3335 | } | |
3336 | ||
3337 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3338 | { | |
3339 | void *objp; | |
3340 | struct array_cache *ac; | |
3341 | bool force_refill = false; | |
3342 | ||
3343 | check_irq_off(); | |
3344 | ||
3345 | ac = cpu_cache_get(cachep); | |
3346 | if (likely(ac->avail)) { | |
3347 | ac->touched = 1; | |
3348 | objp = ac_get_obj(cachep, ac, flags, false); | |
3349 | ||
3350 | /* | |
3351 | * Allow for the possibility all avail objects are not allowed | |
3352 | * by the current flags | |
3353 | */ | |
3354 | if (objp) { | |
3355 | STATS_INC_ALLOCHIT(cachep); | |
3356 | goto out; | |
3357 | } | |
3358 | force_refill = true; | |
3359 | } | |
3360 | ||
3361 | STATS_INC_ALLOCMISS(cachep); | |
3362 | objp = cache_alloc_refill(cachep, flags, force_refill); | |
3363 | /* | |
3364 | * the 'ac' may be updated by cache_alloc_refill(), | |
3365 | * and kmemleak_erase() requires its correct value. | |
3366 | */ | |
3367 | ac = cpu_cache_get(cachep); | |
3368 | ||
3369 | out: | |
3370 | /* | |
3371 | * To avoid a false negative, if an object that is in one of the | |
3372 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't | |
3373 | * treat the array pointers as a reference to the object. | |
3374 | */ | |
3375 | if (objp) | |
3376 | kmemleak_erase(&ac->entry[ac->avail]); | |
3377 | return objp; | |
3378 | } | |
3379 | ||
3380 | #ifdef CONFIG_NUMA | |
3381 | /* | |
3382 | * Try allocating on another node if PF_SPREAD_SLAB|PF_MEMPOLICY. | |
3383 | * | |
3384 | * If we are in_interrupt, then process context, including cpusets and | |
3385 | * mempolicy, may not apply and should not be used for allocation policy. | |
3386 | */ | |
3387 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3388 | { | |
3389 | int nid_alloc, nid_here; | |
3390 | ||
3391 | if (in_interrupt() || (flags & __GFP_THISNODE)) | |
3392 | return NULL; | |
3393 | nid_alloc = nid_here = numa_mem_id(); | |
3394 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) | |
3395 | nid_alloc = cpuset_slab_spread_node(); | |
3396 | else if (current->mempolicy) | |
3397 | nid_alloc = slab_node(); | |
3398 | if (nid_alloc != nid_here) | |
3399 | return ____cache_alloc_node(cachep, flags, nid_alloc); | |
3400 | return NULL; | |
3401 | } | |
3402 | ||
3403 | /* | |
3404 | * Fallback function if there was no memory available and no objects on a | |
3405 | * certain node and fall back is permitted. First we scan all the | |
3406 | * available nodelists for available objects. If that fails then we | |
3407 | * perform an allocation without specifying a node. This allows the page | |
3408 | * allocator to do its reclaim / fallback magic. We then insert the | |
3409 | * slab into the proper nodelist and then allocate from it. | |
3410 | */ | |
3411 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) | |
3412 | { | |
3413 | struct zonelist *zonelist; | |
3414 | gfp_t local_flags; | |
3415 | struct zoneref *z; | |
3416 | struct zone *zone; | |
3417 | enum zone_type high_zoneidx = gfp_zone(flags); | |
3418 | void *obj = NULL; | |
3419 | int nid; | |
3420 | unsigned int cpuset_mems_cookie; | |
3421 | ||
3422 | if (flags & __GFP_THISNODE) | |
3423 | return NULL; | |
3424 | ||
3425 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); | |
3426 | ||
3427 | retry_cpuset: | |
3428 | cpuset_mems_cookie = get_mems_allowed(); | |
3429 | zonelist = node_zonelist(slab_node(), flags); | |
3430 | ||
3431 | retry: | |
3432 | /* | |
3433 | * Look through allowed nodes for objects available | |
3434 | * from existing per node queues. | |
3435 | */ | |
3436 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { | |
3437 | nid = zone_to_nid(zone); | |
3438 | ||
3439 | if (cpuset_zone_allowed_hardwall(zone, flags) && | |
3440 | cache->nodelists[nid] && | |
3441 | cache->nodelists[nid]->free_objects) { | |
3442 | obj = ____cache_alloc_node(cache, | |
3443 | flags | GFP_THISNODE, nid); | |
3444 | if (obj) | |
3445 | break; | |
3446 | } | |
3447 | } | |
3448 | ||
3449 | if (!obj) { | |
3450 | /* | |
3451 | * This allocation will be performed within the constraints | |
3452 | * of the current cpuset / memory policy requirements. | |
3453 | * We may trigger various forms of reclaim on the allowed | |
3454 | * set and go into memory reserves if necessary. | |
3455 | */ | |
3456 | if (local_flags & __GFP_WAIT) | |
3457 | local_irq_enable(); | |
3458 | kmem_flagcheck(cache, flags); | |
3459 | obj = kmem_getpages(cache, local_flags, numa_mem_id()); | |
3460 | if (local_flags & __GFP_WAIT) | |
3461 | local_irq_disable(); | |
3462 | if (obj) { | |
3463 | /* | |
3464 | * Insert into the appropriate per node queues | |
3465 | */ | |
3466 | nid = page_to_nid(virt_to_page(obj)); | |
3467 | if (cache_grow(cache, flags, nid, obj)) { | |
3468 | obj = ____cache_alloc_node(cache, | |
3469 | flags | GFP_THISNODE, nid); | |
3470 | if (!obj) | |
3471 | /* | |
3472 | * Another processor may allocate the | |
3473 | * objects in the slab since we are | |
3474 | * not holding any locks. | |
3475 | */ | |
3476 | goto retry; | |
3477 | } else { | |
3478 | /* cache_grow already freed obj */ | |
3479 | obj = NULL; | |
3480 | } | |
3481 | } | |
3482 | } | |
3483 | ||
3484 | if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !obj)) | |
3485 | goto retry_cpuset; | |
3486 | return obj; | |
3487 | } | |
3488 | ||
3489 | /* | |
3490 | * A interface to enable slab creation on nodeid | |
3491 | */ | |
3492 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, | |
3493 | int nodeid) | |
3494 | { | |
3495 | struct list_head *entry; | |
3496 | struct slab *slabp; | |
3497 | struct kmem_list3 *l3; | |
3498 | void *obj; | |
3499 | int x; | |
3500 | ||
3501 | l3 = cachep->nodelists[nodeid]; | |
3502 | BUG_ON(!l3); | |
3503 | ||
3504 | retry: | |
3505 | check_irq_off(); | |
3506 | spin_lock(&l3->list_lock); | |
3507 | entry = l3->slabs_partial.next; | |
3508 | if (entry == &l3->slabs_partial) { | |
3509 | l3->free_touched = 1; | |
3510 | entry = l3->slabs_free.next; | |
3511 | if (entry == &l3->slabs_free) | |
3512 | goto must_grow; | |
3513 | } | |
3514 | ||
3515 | slabp = list_entry(entry, struct slab, list); | |
3516 | check_spinlock_acquired_node(cachep, nodeid); | |
3517 | check_slabp(cachep, slabp); | |
3518 | ||
3519 | STATS_INC_NODEALLOCS(cachep); | |
3520 | STATS_INC_ACTIVE(cachep); | |
3521 | STATS_SET_HIGH(cachep); | |
3522 | ||
3523 | BUG_ON(slabp->inuse == cachep->num); | |
3524 | ||
3525 | obj = slab_get_obj(cachep, slabp, nodeid); | |
3526 | check_slabp(cachep, slabp); | |
3527 | l3->free_objects--; | |
3528 | /* move slabp to correct slabp list: */ | |
3529 | list_del(&slabp->list); | |
3530 | ||
3531 | if (slabp->free == BUFCTL_END) | |
3532 | list_add(&slabp->list, &l3->slabs_full); | |
3533 | else | |
3534 | list_add(&slabp->list, &l3->slabs_partial); | |
3535 | ||
3536 | spin_unlock(&l3->list_lock); | |
3537 | goto done; | |
3538 | ||
3539 | must_grow: | |
3540 | spin_unlock(&l3->list_lock); | |
3541 | x = cache_grow(cachep, flags | GFP_THISNODE, nodeid, NULL); | |
3542 | if (x) | |
3543 | goto retry; | |
3544 | ||
3545 | return fallback_alloc(cachep, flags); | |
3546 | ||
3547 | done: | |
3548 | return obj; | |
3549 | } | |
3550 | ||
3551 | /** | |
3552 | * kmem_cache_alloc_node - Allocate an object on the specified node | |
3553 | * @cachep: The cache to allocate from. | |
3554 | * @flags: See kmalloc(). | |
3555 | * @nodeid: node number of the target node. | |
3556 | * @caller: return address of caller, used for debug information | |
3557 | * | |
3558 | * Identical to kmem_cache_alloc but it will allocate memory on the given | |
3559 | * node, which can improve the performance for cpu bound structures. | |
3560 | * | |
3561 | * Fallback to other node is possible if __GFP_THISNODE is not set. | |
3562 | */ | |
3563 | static __always_inline void * | |
3564 | __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, | |
3565 | unsigned long caller) | |
3566 | { | |
3567 | unsigned long save_flags; | |
3568 | void *ptr; | |
3569 | int slab_node = numa_mem_id(); | |
3570 | ||
3571 | flags &= gfp_allowed_mask; | |
3572 | ||
3573 | lockdep_trace_alloc(flags); | |
3574 | ||
3575 | if (slab_should_failslab(cachep, flags)) | |
3576 | return NULL; | |
3577 | ||
3578 | cache_alloc_debugcheck_before(cachep, flags); | |
3579 | local_irq_save(save_flags); | |
3580 | ||
3581 | if (nodeid == NUMA_NO_NODE) | |
3582 | nodeid = slab_node; | |
3583 | ||
3584 | if (unlikely(!cachep->nodelists[nodeid])) { | |
3585 | /* Node not bootstrapped yet */ | |
3586 | ptr = fallback_alloc(cachep, flags); | |
3587 | goto out; | |
3588 | } | |
3589 | ||
3590 | if (nodeid == slab_node) { | |
3591 | /* | |
3592 | * Use the locally cached objects if possible. | |
3593 | * However ____cache_alloc does not allow fallback | |
3594 | * to other nodes. It may fail while we still have | |
3595 | * objects on other nodes available. | |
3596 | */ | |
3597 | ptr = ____cache_alloc(cachep, flags); | |
3598 | if (ptr) | |
3599 | goto out; | |
3600 | } | |
3601 | /* ___cache_alloc_node can fall back to other nodes */ | |
3602 | ptr = ____cache_alloc_node(cachep, flags, nodeid); | |
3603 | out: | |
3604 | local_irq_restore(save_flags); | |
3605 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); | |
3606 | kmemleak_alloc_recursive(ptr, cachep->object_size, 1, cachep->flags, | |
3607 | flags); | |
3608 | ||
3609 | if (likely(ptr)) | |
3610 | kmemcheck_slab_alloc(cachep, flags, ptr, cachep->object_size); | |
3611 | ||
3612 | if (unlikely((flags & __GFP_ZERO) && ptr)) | |
3613 | memset(ptr, 0, cachep->object_size); | |
3614 | ||
3615 | return ptr; | |
3616 | } | |
3617 | ||
3618 | static __always_inline void * | |
3619 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) | |
3620 | { | |
3621 | void *objp; | |
3622 | ||
3623 | if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) { | |
3624 | objp = alternate_node_alloc(cache, flags); | |
3625 | if (objp) | |
3626 | goto out; | |
3627 | } | |
3628 | objp = ____cache_alloc(cache, flags); | |
3629 | ||
3630 | /* | |
3631 | * We may just have run out of memory on the local node. | |
3632 | * ____cache_alloc_node() knows how to locate memory on other nodes | |
3633 | */ | |
3634 | if (!objp) | |
3635 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); | |
3636 | ||
3637 | out: | |
3638 | return objp; | |
3639 | } | |
3640 | #else | |
3641 | ||
3642 | static __always_inline void * | |
3643 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3644 | { | |
3645 | return ____cache_alloc(cachep, flags); | |
3646 | } | |
3647 | ||
3648 | #endif /* CONFIG_NUMA */ | |
3649 | ||
3650 | static __always_inline void * | |
3651 | __cache_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) | |
3652 | { | |
3653 | unsigned long save_flags; | |
3654 | void *objp; | |
3655 | ||
3656 | flags &= gfp_allowed_mask; | |
3657 | ||
3658 | lockdep_trace_alloc(flags); | |
3659 | ||
3660 | if (slab_should_failslab(cachep, flags)) | |
3661 | return NULL; | |
3662 | ||
3663 | cache_alloc_debugcheck_before(cachep, flags); | |
3664 | local_irq_save(save_flags); | |
3665 | objp = __do_cache_alloc(cachep, flags); | |
3666 | local_irq_restore(save_flags); | |
3667 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); | |
3668 | kmemleak_alloc_recursive(objp, cachep->object_size, 1, cachep->flags, | |
3669 | flags); | |
3670 | prefetchw(objp); | |
3671 | ||
3672 | if (likely(objp)) | |
3673 | kmemcheck_slab_alloc(cachep, flags, objp, cachep->object_size); | |
3674 | ||
3675 | if (unlikely((flags & __GFP_ZERO) && objp)) | |
3676 | memset(objp, 0, cachep->object_size); | |
3677 | ||
3678 | return objp; | |
3679 | } | |
3680 | ||
3681 | /* | |
3682 | * Caller needs to acquire correct kmem_list's list_lock | |
3683 | */ | |
3684 | static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects, | |
3685 | int node) | |
3686 | { | |
3687 | int i; | |
3688 | struct kmem_list3 *l3; | |
3689 | ||
3690 | for (i = 0; i < nr_objects; i++) { | |
3691 | void *objp; | |
3692 | struct slab *slabp; | |
3693 | ||
3694 | clear_obj_pfmemalloc(&objpp[i]); | |
3695 | objp = objpp[i]; | |
3696 | ||
3697 | slabp = virt_to_slab(objp); | |
3698 | l3 = cachep->nodelists[node]; | |
3699 | list_del(&slabp->list); | |
3700 | check_spinlock_acquired_node(cachep, node); | |
3701 | check_slabp(cachep, slabp); | |
3702 | slab_put_obj(cachep, slabp, objp, node); | |
3703 | STATS_DEC_ACTIVE(cachep); | |
3704 | l3->free_objects++; | |
3705 | check_slabp(cachep, slabp); | |
3706 | ||
3707 | /* fixup slab chains */ | |
3708 | if (slabp->inuse == 0) { | |
3709 | if (l3->free_objects > l3->free_limit) { | |
3710 | l3->free_objects -= cachep->num; | |
3711 | /* No need to drop any previously held | |
3712 | * lock here, even if we have a off-slab slab | |
3713 | * descriptor it is guaranteed to come from | |
3714 | * a different cache, refer to comments before | |
3715 | * alloc_slabmgmt. | |
3716 | */ | |
3717 | slab_destroy(cachep, slabp); | |
3718 | } else { | |
3719 | list_add(&slabp->list, &l3->slabs_free); | |
3720 | } | |
3721 | } else { | |
3722 | /* Unconditionally move a slab to the end of the | |
3723 | * partial list on free - maximum time for the | |
3724 | * other objects to be freed, too. | |
3725 | */ | |
3726 | list_add_tail(&slabp->list, &l3->slabs_partial); | |
3727 | } | |
3728 | } | |
3729 | } | |
3730 | ||
3731 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) | |
3732 | { | |
3733 | int batchcount; | |
3734 | struct kmem_list3 *l3; | |
3735 | int node = numa_mem_id(); | |
3736 | ||
3737 | batchcount = ac->batchcount; | |
3738 | #if DEBUG | |
3739 | BUG_ON(!batchcount || batchcount > ac->avail); | |
3740 | #endif | |
3741 | check_irq_off(); | |
3742 | l3 = cachep->nodelists[node]; | |
3743 | spin_lock(&l3->list_lock); | |
3744 | if (l3->shared) { | |
3745 | struct array_cache *shared_array = l3->shared; | |
3746 | int max = shared_array->limit - shared_array->avail; | |
3747 | if (max) { | |
3748 | if (batchcount > max) | |
3749 | batchcount = max; | |
3750 | memcpy(&(shared_array->entry[shared_array->avail]), | |
3751 | ac->entry, sizeof(void *) * batchcount); | |
3752 | shared_array->avail += batchcount; | |
3753 | goto free_done; | |
3754 | } | |
3755 | } | |
3756 | ||
3757 | free_block(cachep, ac->entry, batchcount, node); | |
3758 | free_done: | |
3759 | #if STATS | |
3760 | { | |
3761 | int i = 0; | |
3762 | struct list_head *p; | |
3763 | ||
3764 | p = l3->slabs_free.next; | |
3765 | while (p != &(l3->slabs_free)) { | |
3766 | struct slab *slabp; | |
3767 | ||
3768 | slabp = list_entry(p, struct slab, list); | |
3769 | BUG_ON(slabp->inuse); | |
3770 | ||
3771 | i++; | |
3772 | p = p->next; | |
3773 | } | |
3774 | STATS_SET_FREEABLE(cachep, i); | |
3775 | } | |
3776 | #endif | |
3777 | spin_unlock(&l3->list_lock); | |
3778 | ac->avail -= batchcount; | |
3779 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); | |
3780 | } | |
3781 | ||
3782 | /* | |
3783 | * Release an obj back to its cache. If the obj has a constructed state, it must | |
3784 | * be in this state _before_ it is released. Called with disabled ints. | |
3785 | */ | |
3786 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, | |
3787 | unsigned long caller) | |
3788 | { | |
3789 | struct array_cache *ac = cpu_cache_get(cachep); | |
3790 | ||
3791 | check_irq_off(); | |
3792 | kmemleak_free_recursive(objp, cachep->flags); | |
3793 | objp = cache_free_debugcheck(cachep, objp, caller); | |
3794 | ||
3795 | kmemcheck_slab_free(cachep, objp, cachep->object_size); | |
3796 | ||
3797 | /* | |
3798 | * Skip calling cache_free_alien() when the platform is not numa. | |
3799 | * This will avoid cache misses that happen while accessing slabp (which | |
3800 | * is per page memory reference) to get nodeid. Instead use a global | |
3801 | * variable to skip the call, which is mostly likely to be present in | |
3802 | * the cache. | |
3803 | */ | |
3804 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) | |
3805 | return; | |
3806 | ||
3807 | if (likely(ac->avail < ac->limit)) { | |
3808 | STATS_INC_FREEHIT(cachep); | |
3809 | } else { | |
3810 | STATS_INC_FREEMISS(cachep); | |
3811 | cache_flusharray(cachep, ac); | |
3812 | } | |
3813 | ||
3814 | ac_put_obj(cachep, ac, objp); | |
3815 | } | |
3816 | ||
3817 | /** | |
3818 | * kmem_cache_alloc - Allocate an object | |
3819 | * @cachep: The cache to allocate from. | |
3820 | * @flags: See kmalloc(). | |
3821 | * | |
3822 | * Allocate an object from this cache. The flags are only relevant | |
3823 | * if the cache has no available objects. | |
3824 | */ | |
3825 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3826 | { | |
3827 | void *ret = __cache_alloc(cachep, flags, _RET_IP_); | |
3828 | ||
3829 | trace_kmem_cache_alloc(_RET_IP_, ret, | |
3830 | cachep->object_size, cachep->size, flags); | |
3831 | ||
3832 | return ret; | |
3833 | } | |
3834 | EXPORT_SYMBOL(kmem_cache_alloc); | |
3835 | ||
3836 | #ifdef CONFIG_TRACING | |
3837 | void * | |
3838 | kmem_cache_alloc_trace(size_t size, struct kmem_cache *cachep, gfp_t flags) | |
3839 | { | |
3840 | void *ret; | |
3841 | ||
3842 | ret = __cache_alloc(cachep, flags, _RET_IP_); | |
3843 | ||
3844 | trace_kmalloc(_RET_IP_, ret, | |
3845 | size, cachep->size, flags); | |
3846 | return ret; | |
3847 | } | |
3848 | EXPORT_SYMBOL(kmem_cache_alloc_trace); | |
3849 | #endif | |
3850 | ||
3851 | #ifdef CONFIG_NUMA | |
3852 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) | |
3853 | { | |
3854 | void *ret = __cache_alloc_node(cachep, flags, nodeid, _RET_IP_); | |
3855 | ||
3856 | trace_kmem_cache_alloc_node(_RET_IP_, ret, | |
3857 | cachep->object_size, cachep->size, | |
3858 | flags, nodeid); | |
3859 | ||
3860 | return ret; | |
3861 | } | |
3862 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
3863 | ||
3864 | #ifdef CONFIG_TRACING | |
3865 | void *kmem_cache_alloc_node_trace(size_t size, | |
3866 | struct kmem_cache *cachep, | |
3867 | gfp_t flags, | |
3868 | int nodeid) | |
3869 | { | |
3870 | void *ret; | |
3871 | ||
3872 | ret = __cache_alloc_node(cachep, flags, nodeid, _RET_IP); | |
3873 | ||
3874 | trace_kmalloc_node(_RET_IP_, ret, | |
3875 | size, cachep->size, | |
3876 | flags, nodeid); | |
3877 | return ret; | |
3878 | } | |
3879 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); | |
3880 | #endif | |
3881 | ||
3882 | static __always_inline void * | |
3883 | __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) | |
3884 | { | |
3885 | struct kmem_cache *cachep; | |
3886 | ||
3887 | cachep = kmem_find_general_cachep(size, flags); | |
3888 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) | |
3889 | return cachep; | |
3890 | return kmem_cache_alloc_node_trace(size, cachep, flags, node); | |
3891 | } | |
3892 | ||
3893 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) | |
3894 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
3895 | { | |
3896 | return __do_kmalloc_node(size, flags, node, _RET_IP_); | |
3897 | } | |
3898 | EXPORT_SYMBOL(__kmalloc_node); | |
3899 | ||
3900 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, | |
3901 | int node, unsigned long caller) | |
3902 | { | |
3903 | return __do_kmalloc_node(size, flags, node, caller); | |
3904 | } | |
3905 | EXPORT_SYMBOL(__kmalloc_node_track_caller); | |
3906 | #else | |
3907 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
3908 | { | |
3909 | return __do_kmalloc_node(size, flags, node, 0); | |
3910 | } | |
3911 | EXPORT_SYMBOL(__kmalloc_node); | |
3912 | #endif /* CONFIG_DEBUG_SLAB || CONFIG_TRACING */ | |
3913 | #endif /* CONFIG_NUMA */ | |
3914 | ||
3915 | /** | |
3916 | * __do_kmalloc - allocate memory | |
3917 | * @size: how many bytes of memory are required. | |
3918 | * @flags: the type of memory to allocate (see kmalloc). | |
3919 | * @caller: function caller for debug tracking of the caller | |
3920 | */ | |
3921 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, | |
3922 | unsigned long caller) | |
3923 | { | |
3924 | struct kmem_cache *cachep; | |
3925 | void *ret; | |
3926 | ||
3927 | /* If you want to save a few bytes .text space: replace | |
3928 | * __ with kmem_. | |
3929 | * Then kmalloc uses the uninlined functions instead of the inline | |
3930 | * functions. | |
3931 | */ | |
3932 | cachep = __find_general_cachep(size, flags); | |
3933 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) | |
3934 | return cachep; | |
3935 | ret = __cache_alloc(cachep, flags, caller); | |
3936 | ||
3937 | trace_kmalloc(caller, ret, | |
3938 | size, cachep->size, flags); | |
3939 | ||
3940 | return ret; | |
3941 | } | |
3942 | ||
3943 | ||
3944 | #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_TRACING) | |
3945 | void *__kmalloc(size_t size, gfp_t flags) | |
3946 | { | |
3947 | return __do_kmalloc(size, flags, _RET_IP_); | |
3948 | } | |
3949 | EXPORT_SYMBOL(__kmalloc); | |
3950 | ||
3951 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) | |
3952 | { | |
3953 | return __do_kmalloc(size, flags, caller); | |
3954 | } | |
3955 | EXPORT_SYMBOL(__kmalloc_track_caller); | |
3956 | ||
3957 | #else | |
3958 | void *__kmalloc(size_t size, gfp_t flags) | |
3959 | { | |
3960 | return __do_kmalloc(size, flags, 0); | |
3961 | } | |
3962 | EXPORT_SYMBOL(__kmalloc); | |
3963 | #endif | |
3964 | ||
3965 | /** | |
3966 | * kmem_cache_free - Deallocate an object | |
3967 | * @cachep: The cache the allocation was from. | |
3968 | * @objp: The previously allocated object. | |
3969 | * | |
3970 | * Free an object which was previously allocated from this | |
3971 | * cache. | |
3972 | */ | |
3973 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) | |
3974 | { | |
3975 | unsigned long flags; | |
3976 | ||
3977 | local_irq_save(flags); | |
3978 | debug_check_no_locks_freed(objp, cachep->object_size); | |
3979 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) | |
3980 | debug_check_no_obj_freed(objp, cachep->object_size); | |
3981 | __cache_free(cachep, objp, _RET_IP_); | |
3982 | local_irq_restore(flags); | |
3983 | ||
3984 | trace_kmem_cache_free(_RET_IP_, objp); | |
3985 | } | |
3986 | EXPORT_SYMBOL(kmem_cache_free); | |
3987 | ||
3988 | /** | |
3989 | * kfree - free previously allocated memory | |
3990 | * @objp: pointer returned by kmalloc. | |
3991 | * | |
3992 | * If @objp is NULL, no operation is performed. | |
3993 | * | |
3994 | * Don't free memory not originally allocated by kmalloc() | |
3995 | * or you will run into trouble. | |
3996 | */ | |
3997 | void kfree(const void *objp) | |
3998 | { | |
3999 | struct kmem_cache *c; | |
4000 | unsigned long flags; | |
4001 | ||
4002 | trace_kfree(_RET_IP_, objp); | |
4003 | ||
4004 | if (unlikely(ZERO_OR_NULL_PTR(objp))) | |
4005 | return; | |
4006 | local_irq_save(flags); | |
4007 | kfree_debugcheck(objp); | |
4008 | c = virt_to_cache(objp); | |
4009 | debug_check_no_locks_freed(objp, c->object_size); | |
4010 | ||
4011 | debug_check_no_obj_freed(objp, c->object_size); | |
4012 | __cache_free(c, (void *)objp, _RET_IP_); | |
4013 | local_irq_restore(flags); | |
4014 | } | |
4015 | EXPORT_SYMBOL(kfree); | |
4016 | ||
4017 | unsigned int kmem_cache_size(struct kmem_cache *cachep) | |
4018 | { | |
4019 | return cachep->object_size; | |
4020 | } | |
4021 | EXPORT_SYMBOL(kmem_cache_size); | |
4022 | ||
4023 | /* | |
4024 | * This initializes kmem_list3 or resizes various caches for all nodes. | |
4025 | */ | |
4026 | static int alloc_kmemlist(struct kmem_cache *cachep, gfp_t gfp) | |
4027 | { | |
4028 | int node; | |
4029 | struct kmem_list3 *l3; | |
4030 | struct array_cache *new_shared; | |
4031 | struct array_cache **new_alien = NULL; | |
4032 | ||
4033 | for_each_online_node(node) { | |
4034 | ||
4035 | if (use_alien_caches) { | |
4036 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); | |
4037 | if (!new_alien) | |
4038 | goto fail; | |
4039 | } | |
4040 | ||
4041 | new_shared = NULL; | |
4042 | if (cachep->shared) { | |
4043 | new_shared = alloc_arraycache(node, | |
4044 | cachep->shared*cachep->batchcount, | |
4045 | 0xbaadf00d, gfp); | |
4046 | if (!new_shared) { | |
4047 | free_alien_cache(new_alien); | |
4048 | goto fail; | |
4049 | } | |
4050 | } | |
4051 | ||
4052 | l3 = cachep->nodelists[node]; | |
4053 | if (l3) { | |
4054 | struct array_cache *shared = l3->shared; | |
4055 | ||
4056 | spin_lock_irq(&l3->list_lock); | |
4057 | ||
4058 | if (shared) | |
4059 | free_block(cachep, shared->entry, | |
4060 | shared->avail, node); | |
4061 | ||
4062 | l3->shared = new_shared; | |
4063 | if (!l3->alien) { | |
4064 | l3->alien = new_alien; | |
4065 | new_alien = NULL; | |
4066 | } | |
4067 | l3->free_limit = (1 + nr_cpus_node(node)) * | |
4068 | cachep->batchcount + cachep->num; | |
4069 | spin_unlock_irq(&l3->list_lock); | |
4070 | kfree(shared); | |
4071 | free_alien_cache(new_alien); | |
4072 | continue; | |
4073 | } | |
4074 | l3 = kmalloc_node(sizeof(struct kmem_list3), gfp, node); | |
4075 | if (!l3) { | |
4076 | free_alien_cache(new_alien); | |
4077 | kfree(new_shared); | |
4078 | goto fail; | |
4079 | } | |
4080 | ||
4081 | kmem_list3_init(l3); | |
4082 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3 + | |
4083 | ((unsigned long)cachep) % REAPTIMEOUT_LIST3; | |
4084 | l3->shared = new_shared; | |
4085 | l3->alien = new_alien; | |
4086 | l3->free_limit = (1 + nr_cpus_node(node)) * | |
4087 | cachep->batchcount + cachep->num; | |
4088 | cachep->nodelists[node] = l3; | |
4089 | } | |
4090 | return 0; | |
4091 | ||
4092 | fail: | |
4093 | if (!cachep->list.next) { | |
4094 | /* Cache is not active yet. Roll back what we did */ | |
4095 | node--; | |
4096 | while (node >= 0) { | |
4097 | if (cachep->nodelists[node]) { | |
4098 | l3 = cachep->nodelists[node]; | |
4099 | ||
4100 | kfree(l3->shared); | |
4101 | free_alien_cache(l3->alien); | |
4102 | kfree(l3); | |
4103 | cachep->nodelists[node] = NULL; | |
4104 | } | |
4105 | node--; | |
4106 | } | |
4107 | } | |
4108 | return -ENOMEM; | |
4109 | } | |
4110 | ||
4111 | struct ccupdate_struct { | |
4112 | struct kmem_cache *cachep; | |
4113 | struct array_cache *new[0]; | |
4114 | }; | |
4115 | ||
4116 | static void do_ccupdate_local(void *info) | |
4117 | { | |
4118 | struct ccupdate_struct *new = info; | |
4119 | struct array_cache *old; | |
4120 | ||
4121 | check_irq_off(); | |
4122 | old = cpu_cache_get(new->cachep); | |
4123 | ||
4124 | new->cachep->array[smp_processor_id()] = new->new[smp_processor_id()]; | |
4125 | new->new[smp_processor_id()] = old; | |
4126 | } | |
4127 | ||
4128 | /* Always called with the slab_mutex held */ | |
4129 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, | |
4130 | int batchcount, int shared, gfp_t gfp) | |
4131 | { | |
4132 | struct ccupdate_struct *new; | |
4133 | int i; | |
4134 | ||
4135 | new = kzalloc(sizeof(*new) + nr_cpu_ids * sizeof(struct array_cache *), | |
4136 | gfp); | |
4137 | if (!new) | |
4138 | return -ENOMEM; | |
4139 | ||
4140 | for_each_online_cpu(i) { | |
4141 | new->new[i] = alloc_arraycache(cpu_to_mem(i), limit, | |
4142 | batchcount, gfp); | |
4143 | if (!new->new[i]) { | |
4144 | for (i--; i >= 0; i--) | |
4145 | kfree(new->new[i]); | |
4146 | kfree(new); | |
4147 | return -ENOMEM; | |
4148 | } | |
4149 | } | |
4150 | new->cachep = cachep; | |
4151 | ||
4152 | on_each_cpu(do_ccupdate_local, (void *)new, 1); | |
4153 | ||
4154 | check_irq_on(); | |
4155 | cachep->batchcount = batchcount; | |
4156 | cachep->limit = limit; | |
4157 | cachep->shared = shared; | |
4158 | ||
4159 | for_each_online_cpu(i) { | |
4160 | struct array_cache *ccold = new->new[i]; | |
4161 | if (!ccold) | |
4162 | continue; | |
4163 | spin_lock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); | |
4164 | free_block(cachep, ccold->entry, ccold->avail, cpu_to_mem(i)); | |
4165 | spin_unlock_irq(&cachep->nodelists[cpu_to_mem(i)]->list_lock); | |
4166 | kfree(ccold); | |
4167 | } | |
4168 | kfree(new); | |
4169 | return alloc_kmemlist(cachep, gfp); | |
4170 | } | |
4171 | ||
4172 | /* Called with slab_mutex held always */ | |
4173 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) | |
4174 | { | |
4175 | int err; | |
4176 | int limit, shared; | |
4177 | ||
4178 | /* | |
4179 | * The head array serves three purposes: | |
4180 | * - create a LIFO ordering, i.e. return objects that are cache-warm | |
4181 | * - reduce the number of spinlock operations. | |
4182 | * - reduce the number of linked list operations on the slab and | |
4183 | * bufctl chains: array operations are cheaper. | |
4184 | * The numbers are guessed, we should auto-tune as described by | |
4185 | * Bonwick. | |
4186 | */ | |
4187 | if (cachep->size > 131072) | |
4188 | limit = 1; | |
4189 | else if (cachep->size > PAGE_SIZE) | |
4190 | limit = 8; | |
4191 | else if (cachep->size > 1024) | |
4192 | limit = 24; | |
4193 | else if (cachep->size > 256) | |
4194 | limit = 54; | |
4195 | else | |
4196 | limit = 120; | |
4197 | ||
4198 | /* | |
4199 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound | |
4200 | * allocation behaviour: Most allocs on one cpu, most free operations | |
4201 | * on another cpu. For these cases, an efficient object passing between | |
4202 | * cpus is necessary. This is provided by a shared array. The array | |
4203 | * replaces Bonwick's magazine layer. | |
4204 | * On uniprocessor, it's functionally equivalent (but less efficient) | |
4205 | * to a larger limit. Thus disabled by default. | |
4206 | */ | |
4207 | shared = 0; | |
4208 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) | |
4209 | shared = 8; | |
4210 | ||
4211 | #if DEBUG | |
4212 | /* | |
4213 | * With debugging enabled, large batchcount lead to excessively long | |
4214 | * periods with disabled local interrupts. Limit the batchcount | |
4215 | */ | |
4216 | if (limit > 32) | |
4217 | limit = 32; | |
4218 | #endif | |
4219 | err = do_tune_cpucache(cachep, limit, (limit + 1) / 2, shared, gfp); | |
4220 | if (err) | |
4221 | printk(KERN_ERR "enable_cpucache failed for %s, error %d.\n", | |
4222 | cachep->name, -err); | |
4223 | return err; | |
4224 | } | |
4225 | ||
4226 | /* | |
4227 | * Drain an array if it contains any elements taking the l3 lock only if | |
4228 | * necessary. Note that the l3 listlock also protects the array_cache | |
4229 | * if drain_array() is used on the shared array. | |
4230 | */ | |
4231 | static void drain_array(struct kmem_cache *cachep, struct kmem_list3 *l3, | |
4232 | struct array_cache *ac, int force, int node) | |
4233 | { | |
4234 | int tofree; | |
4235 | ||
4236 | if (!ac || !ac->avail) | |
4237 | return; | |
4238 | if (ac->touched && !force) { | |
4239 | ac->touched = 0; | |
4240 | } else { | |
4241 | spin_lock_irq(&l3->list_lock); | |
4242 | if (ac->avail) { | |
4243 | tofree = force ? ac->avail : (ac->limit + 4) / 5; | |
4244 | if (tofree > ac->avail) | |
4245 | tofree = (ac->avail + 1) / 2; | |
4246 | free_block(cachep, ac->entry, tofree, node); | |
4247 | ac->avail -= tofree; | |
4248 | memmove(ac->entry, &(ac->entry[tofree]), | |
4249 | sizeof(void *) * ac->avail); | |
4250 | } | |
4251 | spin_unlock_irq(&l3->list_lock); | |
4252 | } | |
4253 | } | |
4254 | ||
4255 | /** | |
4256 | * cache_reap - Reclaim memory from caches. | |
4257 | * @w: work descriptor | |
4258 | * | |
4259 | * Called from workqueue/eventd every few seconds. | |
4260 | * Purpose: | |
4261 | * - clear the per-cpu caches for this CPU. | |
4262 | * - return freeable pages to the main free memory pool. | |
4263 | * | |
4264 | * If we cannot acquire the cache chain mutex then just give up - we'll try | |
4265 | * again on the next iteration. | |
4266 | */ | |
4267 | static void cache_reap(struct work_struct *w) | |
4268 | { | |
4269 | struct kmem_cache *searchp; | |
4270 | struct kmem_list3 *l3; | |
4271 | int node = numa_mem_id(); | |
4272 | struct delayed_work *work = to_delayed_work(w); | |
4273 | ||
4274 | if (!mutex_trylock(&slab_mutex)) | |
4275 | /* Give up. Setup the next iteration. */ | |
4276 | goto out; | |
4277 | ||
4278 | list_for_each_entry(searchp, &slab_caches, list) { | |
4279 | check_irq_on(); | |
4280 | ||
4281 | /* | |
4282 | * We only take the l3 lock if absolutely necessary and we | |
4283 | * have established with reasonable certainty that | |
4284 | * we can do some work if the lock was obtained. | |
4285 | */ | |
4286 | l3 = searchp->nodelists[node]; | |
4287 | ||
4288 | reap_alien(searchp, l3); | |
4289 | ||
4290 | drain_array(searchp, l3, cpu_cache_get(searchp), 0, node); | |
4291 | ||
4292 | /* | |
4293 | * These are racy checks but it does not matter | |
4294 | * if we skip one check or scan twice. | |
4295 | */ | |
4296 | if (time_after(l3->next_reap, jiffies)) | |
4297 | goto next; | |
4298 | ||
4299 | l3->next_reap = jiffies + REAPTIMEOUT_LIST3; | |
4300 | ||
4301 | drain_array(searchp, l3, l3->shared, 0, node); | |
4302 | ||
4303 | if (l3->free_touched) | |
4304 | l3->free_touched = 0; | |
4305 | else { | |
4306 | int freed; | |
4307 | ||
4308 | freed = drain_freelist(searchp, l3, (l3->free_limit + | |
4309 | 5 * searchp->num - 1) / (5 * searchp->num)); | |
4310 | STATS_ADD_REAPED(searchp, freed); | |
4311 | } | |
4312 | next: | |
4313 | cond_resched(); | |
4314 | } | |
4315 | check_irq_on(); | |
4316 | mutex_unlock(&slab_mutex); | |
4317 | next_reap_node(); | |
4318 | out: | |
4319 | /* Set up the next iteration */ | |
4320 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_CPUC)); | |
4321 | } | |
4322 | ||
4323 | #ifdef CONFIG_SLABINFO | |
4324 | ||
4325 | static void print_slabinfo_header(struct seq_file *m) | |
4326 | { | |
4327 | /* | |
4328 | * Output format version, so at least we can change it | |
4329 | * without _too_ many complaints. | |
4330 | */ | |
4331 | #if STATS | |
4332 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
4333 | #else | |
4334 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
4335 | #endif | |
4336 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " | |
4337 | "<objperslab> <pagesperslab>"); | |
4338 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); | |
4339 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
4340 | #if STATS | |
4341 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " | |
4342 | "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); | |
4343 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); | |
4344 | #endif | |
4345 | seq_putc(m, '\n'); | |
4346 | } | |
4347 | ||
4348 | static void *s_start(struct seq_file *m, loff_t *pos) | |
4349 | { | |
4350 | loff_t n = *pos; | |
4351 | ||
4352 | mutex_lock(&slab_mutex); | |
4353 | if (!n) | |
4354 | print_slabinfo_header(m); | |
4355 | ||
4356 | return seq_list_start(&slab_caches, *pos); | |
4357 | } | |
4358 | ||
4359 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
4360 | { | |
4361 | return seq_list_next(p, &slab_caches, pos); | |
4362 | } | |
4363 | ||
4364 | static void s_stop(struct seq_file *m, void *p) | |
4365 | { | |
4366 | mutex_unlock(&slab_mutex); | |
4367 | } | |
4368 | ||
4369 | static int s_show(struct seq_file *m, void *p) | |
4370 | { | |
4371 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); | |
4372 | struct slab *slabp; | |
4373 | unsigned long active_objs; | |
4374 | unsigned long num_objs; | |
4375 | unsigned long active_slabs = 0; | |
4376 | unsigned long num_slabs, free_objects = 0, shared_avail = 0; | |
4377 | const char *name; | |
4378 | char *error = NULL; | |
4379 | int node; | |
4380 | struct kmem_list3 *l3; | |
4381 | ||
4382 | active_objs = 0; | |
4383 | num_slabs = 0; | |
4384 | for_each_online_node(node) { | |
4385 | l3 = cachep->nodelists[node]; | |
4386 | if (!l3) | |
4387 | continue; | |
4388 | ||
4389 | check_irq_on(); | |
4390 | spin_lock_irq(&l3->list_lock); | |
4391 | ||
4392 | list_for_each_entry(slabp, &l3->slabs_full, list) { | |
4393 | if (slabp->inuse != cachep->num && !error) | |
4394 | error = "slabs_full accounting error"; | |
4395 | active_objs += cachep->num; | |
4396 | active_slabs++; | |
4397 | } | |
4398 | list_for_each_entry(slabp, &l3->slabs_partial, list) { | |
4399 | if (slabp->inuse == cachep->num && !error) | |
4400 | error = "slabs_partial inuse accounting error"; | |
4401 | if (!slabp->inuse && !error) | |
4402 | error = "slabs_partial/inuse accounting error"; | |
4403 | active_objs += slabp->inuse; | |
4404 | active_slabs++; | |
4405 | } | |
4406 | list_for_each_entry(slabp, &l3->slabs_free, list) { | |
4407 | if (slabp->inuse && !error) | |
4408 | error = "slabs_free/inuse accounting error"; | |
4409 | num_slabs++; | |
4410 | } | |
4411 | free_objects += l3->free_objects; | |
4412 | if (l3->shared) | |
4413 | shared_avail += l3->shared->avail; | |
4414 | ||
4415 | spin_unlock_irq(&l3->list_lock); | |
4416 | } | |
4417 | num_slabs += active_slabs; | |
4418 | num_objs = num_slabs * cachep->num; | |
4419 | if (num_objs - active_objs != free_objects && !error) | |
4420 | error = "free_objects accounting error"; | |
4421 | ||
4422 | name = cachep->name; | |
4423 | if (error) | |
4424 | printk(KERN_ERR "slab: cache %s error: %s\n", name, error); | |
4425 | ||
4426 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", | |
4427 | name, active_objs, num_objs, cachep->size, | |
4428 | cachep->num, (1 << cachep->gfporder)); | |
4429 | seq_printf(m, " : tunables %4u %4u %4u", | |
4430 | cachep->limit, cachep->batchcount, cachep->shared); | |
4431 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
4432 | active_slabs, num_slabs, shared_avail); | |
4433 | #if STATS | |
4434 | { /* list3 stats */ | |
4435 | unsigned long high = cachep->high_mark; | |
4436 | unsigned long allocs = cachep->num_allocations; | |
4437 | unsigned long grown = cachep->grown; | |
4438 | unsigned long reaped = cachep->reaped; | |
4439 | unsigned long errors = cachep->errors; | |
4440 | unsigned long max_freeable = cachep->max_freeable; | |
4441 | unsigned long node_allocs = cachep->node_allocs; | |
4442 | unsigned long node_frees = cachep->node_frees; | |
4443 | unsigned long overflows = cachep->node_overflow; | |
4444 | ||
4445 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu " | |
4446 | "%4lu %4lu %4lu %4lu %4lu", | |
4447 | allocs, high, grown, | |
4448 | reaped, errors, max_freeable, node_allocs, | |
4449 | node_frees, overflows); | |
4450 | } | |
4451 | /* cpu stats */ | |
4452 | { | |
4453 | unsigned long allochit = atomic_read(&cachep->allochit); | |
4454 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); | |
4455 | unsigned long freehit = atomic_read(&cachep->freehit); | |
4456 | unsigned long freemiss = atomic_read(&cachep->freemiss); | |
4457 | ||
4458 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", | |
4459 | allochit, allocmiss, freehit, freemiss); | |
4460 | } | |
4461 | #endif | |
4462 | seq_putc(m, '\n'); | |
4463 | return 0; | |
4464 | } | |
4465 | ||
4466 | /* | |
4467 | * slabinfo_op - iterator that generates /proc/slabinfo | |
4468 | * | |
4469 | * Output layout: | |
4470 | * cache-name | |
4471 | * num-active-objs | |
4472 | * total-objs | |
4473 | * object size | |
4474 | * num-active-slabs | |
4475 | * total-slabs | |
4476 | * num-pages-per-slab | |
4477 | * + further values on SMP and with statistics enabled | |
4478 | */ | |
4479 | ||
4480 | static const struct seq_operations slabinfo_op = { | |
4481 | .start = s_start, | |
4482 | .next = s_next, | |
4483 | .stop = s_stop, | |
4484 | .show = s_show, | |
4485 | }; | |
4486 | ||
4487 | #define MAX_SLABINFO_WRITE 128 | |
4488 | /** | |
4489 | * slabinfo_write - Tuning for the slab allocator | |
4490 | * @file: unused | |
4491 | * @buffer: user buffer | |
4492 | * @count: data length | |
4493 | * @ppos: unused | |
4494 | */ | |
4495 | static ssize_t slabinfo_write(struct file *file, const char __user *buffer, | |
4496 | size_t count, loff_t *ppos) | |
4497 | { | |
4498 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; | |
4499 | int limit, batchcount, shared, res; | |
4500 | struct kmem_cache *cachep; | |
4501 | ||
4502 | if (count > MAX_SLABINFO_WRITE) | |
4503 | return -EINVAL; | |
4504 | if (copy_from_user(&kbuf, buffer, count)) | |
4505 | return -EFAULT; | |
4506 | kbuf[MAX_SLABINFO_WRITE] = '\0'; | |
4507 | ||
4508 | tmp = strchr(kbuf, ' '); | |
4509 | if (!tmp) | |
4510 | return -EINVAL; | |
4511 | *tmp = '\0'; | |
4512 | tmp++; | |
4513 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) | |
4514 | return -EINVAL; | |
4515 | ||
4516 | /* Find the cache in the chain of caches. */ | |
4517 | mutex_lock(&slab_mutex); | |
4518 | res = -EINVAL; | |
4519 | list_for_each_entry(cachep, &slab_caches, list) { | |
4520 | if (!strcmp(cachep->name, kbuf)) { | |
4521 | if (limit < 1 || batchcount < 1 || | |
4522 | batchcount > limit || shared < 0) { | |
4523 | res = 0; | |
4524 | } else { | |
4525 | res = do_tune_cpucache(cachep, limit, | |
4526 | batchcount, shared, | |
4527 | GFP_KERNEL); | |
4528 | } | |
4529 | break; | |
4530 | } | |
4531 | } | |
4532 | mutex_unlock(&slab_mutex); | |
4533 | if (res >= 0) | |
4534 | res = count; | |
4535 | return res; | |
4536 | } | |
4537 | ||
4538 | static int slabinfo_open(struct inode *inode, struct file *file) | |
4539 | { | |
4540 | return seq_open(file, &slabinfo_op); | |
4541 | } | |
4542 | ||
4543 | static const struct file_operations proc_slabinfo_operations = { | |
4544 | .open = slabinfo_open, | |
4545 | .read = seq_read, | |
4546 | .write = slabinfo_write, | |
4547 | .llseek = seq_lseek, | |
4548 | .release = seq_release, | |
4549 | }; | |
4550 | ||
4551 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
4552 | ||
4553 | static void *leaks_start(struct seq_file *m, loff_t *pos) | |
4554 | { | |
4555 | mutex_lock(&slab_mutex); | |
4556 | return seq_list_start(&slab_caches, *pos); | |
4557 | } | |
4558 | ||
4559 | static inline int add_caller(unsigned long *n, unsigned long v) | |
4560 | { | |
4561 | unsigned long *p; | |
4562 | int l; | |
4563 | if (!v) | |
4564 | return 1; | |
4565 | l = n[1]; | |
4566 | p = n + 2; | |
4567 | while (l) { | |
4568 | int i = l/2; | |
4569 | unsigned long *q = p + 2 * i; | |
4570 | if (*q == v) { | |
4571 | q[1]++; | |
4572 | return 1; | |
4573 | } | |
4574 | if (*q > v) { | |
4575 | l = i; | |
4576 | } else { | |
4577 | p = q + 2; | |
4578 | l -= i + 1; | |
4579 | } | |
4580 | } | |
4581 | if (++n[1] == n[0]) | |
4582 | return 0; | |
4583 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); | |
4584 | p[0] = v; | |
4585 | p[1] = 1; | |
4586 | return 1; | |
4587 | } | |
4588 | ||
4589 | static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s) | |
4590 | { | |
4591 | void *p; | |
4592 | int i; | |
4593 | if (n[0] == n[1]) | |
4594 | return; | |
4595 | for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) { | |
4596 | if (slab_bufctl(s)[i] != BUFCTL_ACTIVE) | |
4597 | continue; | |
4598 | if (!add_caller(n, (unsigned long)*dbg_userword(c, p))) | |
4599 | return; | |
4600 | } | |
4601 | } | |
4602 | ||
4603 | static void show_symbol(struct seq_file *m, unsigned long address) | |
4604 | { | |
4605 | #ifdef CONFIG_KALLSYMS | |
4606 | unsigned long offset, size; | |
4607 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; | |
4608 | ||
4609 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { | |
4610 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); | |
4611 | if (modname[0]) | |
4612 | seq_printf(m, " [%s]", modname); | |
4613 | return; | |
4614 | } | |
4615 | #endif | |
4616 | seq_printf(m, "%p", (void *)address); | |
4617 | } | |
4618 | ||
4619 | static int leaks_show(struct seq_file *m, void *p) | |
4620 | { | |
4621 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); | |
4622 | struct slab *slabp; | |
4623 | struct kmem_list3 *l3; | |
4624 | const char *name; | |
4625 | unsigned long *n = m->private; | |
4626 | int node; | |
4627 | int i; | |
4628 | ||
4629 | if (!(cachep->flags & SLAB_STORE_USER)) | |
4630 | return 0; | |
4631 | if (!(cachep->flags & SLAB_RED_ZONE)) | |
4632 | return 0; | |
4633 | ||
4634 | /* OK, we can do it */ | |
4635 | ||
4636 | n[1] = 0; | |
4637 | ||
4638 | for_each_online_node(node) { | |
4639 | l3 = cachep->nodelists[node]; | |
4640 | if (!l3) | |
4641 | continue; | |
4642 | ||
4643 | check_irq_on(); | |
4644 | spin_lock_irq(&l3->list_lock); | |
4645 | ||
4646 | list_for_each_entry(slabp, &l3->slabs_full, list) | |
4647 | handle_slab(n, cachep, slabp); | |
4648 | list_for_each_entry(slabp, &l3->slabs_partial, list) | |
4649 | handle_slab(n, cachep, slabp); | |
4650 | spin_unlock_irq(&l3->list_lock); | |
4651 | } | |
4652 | name = cachep->name; | |
4653 | if (n[0] == n[1]) { | |
4654 | /* Increase the buffer size */ | |
4655 | mutex_unlock(&slab_mutex); | |
4656 | m->private = kzalloc(n[0] * 4 * sizeof(unsigned long), GFP_KERNEL); | |
4657 | if (!m->private) { | |
4658 | /* Too bad, we are really out */ | |
4659 | m->private = n; | |
4660 | mutex_lock(&slab_mutex); | |
4661 | return -ENOMEM; | |
4662 | } | |
4663 | *(unsigned long *)m->private = n[0] * 2; | |
4664 | kfree(n); | |
4665 | mutex_lock(&slab_mutex); | |
4666 | /* Now make sure this entry will be retried */ | |
4667 | m->count = m->size; | |
4668 | return 0; | |
4669 | } | |
4670 | for (i = 0; i < n[1]; i++) { | |
4671 | seq_printf(m, "%s: %lu ", name, n[2*i+3]); | |
4672 | show_symbol(m, n[2*i+2]); | |
4673 | seq_putc(m, '\n'); | |
4674 | } | |
4675 | ||
4676 | return 0; | |
4677 | } | |
4678 | ||
4679 | static const struct seq_operations slabstats_op = { | |
4680 | .start = leaks_start, | |
4681 | .next = s_next, | |
4682 | .stop = s_stop, | |
4683 | .show = leaks_show, | |
4684 | }; | |
4685 | ||
4686 | static int slabstats_open(struct inode *inode, struct file *file) | |
4687 | { | |
4688 | unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL); | |
4689 | int ret = -ENOMEM; | |
4690 | if (n) { | |
4691 | ret = seq_open(file, &slabstats_op); | |
4692 | if (!ret) { | |
4693 | struct seq_file *m = file->private_data; | |
4694 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); | |
4695 | m->private = n; | |
4696 | n = NULL; | |
4697 | } | |
4698 | kfree(n); | |
4699 | } | |
4700 | return ret; | |
4701 | } | |
4702 | ||
4703 | static const struct file_operations proc_slabstats_operations = { | |
4704 | .open = slabstats_open, | |
4705 | .read = seq_read, | |
4706 | .llseek = seq_lseek, | |
4707 | .release = seq_release_private, | |
4708 | }; | |
4709 | #endif | |
4710 | ||
4711 | static int __init slab_proc_init(void) | |
4712 | { | |
4713 | proc_create("slabinfo",S_IWUSR|S_IRUSR,NULL,&proc_slabinfo_operations); | |
4714 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
4715 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); | |
4716 | #endif | |
4717 | return 0; | |
4718 | } | |
4719 | module_init(slab_proc_init); | |
4720 | #endif | |
4721 | ||
4722 | /** | |
4723 | * ksize - get the actual amount of memory allocated for a given object | |
4724 | * @objp: Pointer to the object | |
4725 | * | |
4726 | * kmalloc may internally round up allocations and return more memory | |
4727 | * than requested. ksize() can be used to determine the actual amount of | |
4728 | * memory allocated. The caller may use this additional memory, even though | |
4729 | * a smaller amount of memory was initially specified with the kmalloc call. | |
4730 | * The caller must guarantee that objp points to a valid object previously | |
4731 | * allocated with either kmalloc() or kmem_cache_alloc(). The object | |
4732 | * must not be freed during the duration of the call. | |
4733 | */ | |
4734 | size_t ksize(const void *objp) | |
4735 | { | |
4736 | BUG_ON(!objp); | |
4737 | if (unlikely(objp == ZERO_SIZE_PTR)) | |
4738 | return 0; | |
4739 | ||
4740 | return virt_to_cache(objp)->object_size; | |
4741 | } | |
4742 | EXPORT_SYMBOL(ksize); |