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1 | /* | |
2 | * SLOB Allocator: Simple List Of Blocks | |
3 | * | |
4 | * Matt Mackall <mpm@selenic.com> 12/30/03 | |
5 | * | |
6 | * NUMA support by Paul Mundt, 2007. | |
7 | * | |
8 | * How SLOB works: | |
9 | * | |
10 | * The core of SLOB is a traditional K&R style heap allocator, with | |
11 | * support for returning aligned objects. The granularity of this | |
12 | * allocator is as little as 2 bytes, however typically most architectures | |
13 | * will require 4 bytes on 32-bit and 8 bytes on 64-bit. | |
14 | * | |
15 | * The slob heap is a set of linked list of pages from alloc_pages(), | |
16 | * and within each page, there is a singly-linked list of free blocks | |
17 | * (slob_t). The heap is grown on demand. To reduce fragmentation, | |
18 | * heap pages are segregated into three lists, with objects less than | |
19 | * 256 bytes, objects less than 1024 bytes, and all other objects. | |
20 | * | |
21 | * Allocation from heap involves first searching for a page with | |
22 | * sufficient free blocks (using a next-fit-like approach) followed by | |
23 | * a first-fit scan of the page. Deallocation inserts objects back | |
24 | * into the free list in address order, so this is effectively an | |
25 | * address-ordered first fit. | |
26 | * | |
27 | * Above this is an implementation of kmalloc/kfree. Blocks returned | |
28 | * from kmalloc are prepended with a 4-byte header with the kmalloc size. | |
29 | * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls | |
30 | * alloc_pages() directly, allocating compound pages so the page order | |
31 | * does not have to be separately tracked, and also stores the exact | |
32 | * allocation size in page->private so that it can be used to accurately | |
33 | * provide ksize(). These objects are detected in kfree() because slob_page() | |
34 | * is false for them. | |
35 | * | |
36 | * SLAB is emulated on top of SLOB by simply calling constructors and | |
37 | * destructors for every SLAB allocation. Objects are returned with the | |
38 | * 4-byte alignment unless the SLAB_HWCACHE_ALIGN flag is set, in which | |
39 | * case the low-level allocator will fragment blocks to create the proper | |
40 | * alignment. Again, objects of page-size or greater are allocated by | |
41 | * calling alloc_pages(). As SLAB objects know their size, no separate | |
42 | * size bookkeeping is necessary and there is essentially no allocation | |
43 | * space overhead, and compound pages aren't needed for multi-page | |
44 | * allocations. | |
45 | * | |
46 | * NUMA support in SLOB is fairly simplistic, pushing most of the real | |
47 | * logic down to the page allocator, and simply doing the node accounting | |
48 | * on the upper levels. In the event that a node id is explicitly | |
49 | * provided, alloc_pages_node() with the specified node id is used | |
50 | * instead. The common case (or when the node id isn't explicitly provided) | |
51 | * will default to the current node, as per numa_node_id(). | |
52 | * | |
53 | * Node aware pages are still inserted in to the global freelist, and | |
54 | * these are scanned for by matching against the node id encoded in the | |
55 | * page flags. As a result, block allocations that can be satisfied from | |
56 | * the freelist will only be done so on pages residing on the same node, | |
57 | * in order to prevent random node placement. | |
58 | */ | |
59 | ||
60 | #include <linux/kernel.h> | |
61 | #include <linux/slab.h> | |
62 | #include <linux/mm.h> | |
63 | #include <linux/cache.h> | |
64 | #include <linux/init.h> | |
65 | #include <linux/module.h> | |
66 | #include <linux/rcupdate.h> | |
67 | #include <linux/list.h> | |
68 | #include <asm/atomic.h> | |
69 | ||
70 | /* | |
71 | * slob_block has a field 'units', which indicates size of block if +ve, | |
72 | * or offset of next block if -ve (in SLOB_UNITs). | |
73 | * | |
74 | * Free blocks of size 1 unit simply contain the offset of the next block. | |
75 | * Those with larger size contain their size in the first SLOB_UNIT of | |
76 | * memory, and the offset of the next free block in the second SLOB_UNIT. | |
77 | */ | |
78 | #if PAGE_SIZE <= (32767 * 2) | |
79 | typedef s16 slobidx_t; | |
80 | #else | |
81 | typedef s32 slobidx_t; | |
82 | #endif | |
83 | ||
84 | struct slob_block { | |
85 | slobidx_t units; | |
86 | }; | |
87 | typedef struct slob_block slob_t; | |
88 | ||
89 | /* | |
90 | * We use struct page fields to manage some slob allocation aspects, | |
91 | * however to avoid the horrible mess in include/linux/mm_types.h, we'll | |
92 | * just define our own struct page type variant here. | |
93 | */ | |
94 | struct slob_page { | |
95 | union { | |
96 | struct { | |
97 | unsigned long flags; /* mandatory */ | |
98 | atomic_t _count; /* mandatory */ | |
99 | slobidx_t units; /* free units left in page */ | |
100 | unsigned long pad[2]; | |
101 | slob_t *free; /* first free slob_t in page */ | |
102 | struct list_head list; /* linked list of free pages */ | |
103 | }; | |
104 | struct page page; | |
105 | }; | |
106 | }; | |
107 | static inline void struct_slob_page_wrong_size(void) | |
108 | { BUILD_BUG_ON(sizeof(struct slob_page) != sizeof(struct page)); } | |
109 | ||
110 | /* | |
111 | * free_slob_page: call before a slob_page is returned to the page allocator. | |
112 | */ | |
113 | static inline void free_slob_page(struct slob_page *sp) | |
114 | { | |
115 | reset_page_mapcount(&sp->page); | |
116 | sp->page.mapping = NULL; | |
117 | } | |
118 | ||
119 | /* | |
120 | * All partially free slob pages go on these lists. | |
121 | */ | |
122 | #define SLOB_BREAK1 256 | |
123 | #define SLOB_BREAK2 1024 | |
124 | static LIST_HEAD(free_slob_small); | |
125 | static LIST_HEAD(free_slob_medium); | |
126 | static LIST_HEAD(free_slob_large); | |
127 | ||
128 | /* | |
129 | * is_slob_page: True for all slob pages (false for bigblock pages) | |
130 | */ | |
131 | static inline int is_slob_page(struct slob_page *sp) | |
132 | { | |
133 | return PageSlobPage((struct page *)sp); | |
134 | } | |
135 | ||
136 | static inline void set_slob_page(struct slob_page *sp) | |
137 | { | |
138 | __SetPageSlobPage((struct page *)sp); | |
139 | } | |
140 | ||
141 | static inline void clear_slob_page(struct slob_page *sp) | |
142 | { | |
143 | __ClearPageSlobPage((struct page *)sp); | |
144 | } | |
145 | ||
146 | static inline struct slob_page *slob_page(const void *addr) | |
147 | { | |
148 | return (struct slob_page *)virt_to_page(addr); | |
149 | } | |
150 | ||
151 | /* | |
152 | * slob_page_free: true for pages on free_slob_pages list. | |
153 | */ | |
154 | static inline int slob_page_free(struct slob_page *sp) | |
155 | { | |
156 | return PageSlobFree((struct page *)sp); | |
157 | } | |
158 | ||
159 | static void set_slob_page_free(struct slob_page *sp, struct list_head *list) | |
160 | { | |
161 | list_add(&sp->list, list); | |
162 | __SetPageSlobFree((struct page *)sp); | |
163 | } | |
164 | ||
165 | static inline void clear_slob_page_free(struct slob_page *sp) | |
166 | { | |
167 | list_del(&sp->list); | |
168 | __ClearPageSlobFree((struct page *)sp); | |
169 | } | |
170 | ||
171 | #define SLOB_UNIT sizeof(slob_t) | |
172 | #define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT) | |
173 | #define SLOB_ALIGN L1_CACHE_BYTES | |
174 | ||
175 | /* | |
176 | * struct slob_rcu is inserted at the tail of allocated slob blocks, which | |
177 | * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free | |
178 | * the block using call_rcu. | |
179 | */ | |
180 | struct slob_rcu { | |
181 | struct rcu_head head; | |
182 | int size; | |
183 | }; | |
184 | ||
185 | /* | |
186 | * slob_lock protects all slob allocator structures. | |
187 | */ | |
188 | static DEFINE_SPINLOCK(slob_lock); | |
189 | ||
190 | /* | |
191 | * Encode the given size and next info into a free slob block s. | |
192 | */ | |
193 | static void set_slob(slob_t *s, slobidx_t size, slob_t *next) | |
194 | { | |
195 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
196 | slobidx_t offset = next - base; | |
197 | ||
198 | if (size > 1) { | |
199 | s[0].units = size; | |
200 | s[1].units = offset; | |
201 | } else | |
202 | s[0].units = -offset; | |
203 | } | |
204 | ||
205 | /* | |
206 | * Return the size of a slob block. | |
207 | */ | |
208 | static slobidx_t slob_units(slob_t *s) | |
209 | { | |
210 | if (s->units > 0) | |
211 | return s->units; | |
212 | return 1; | |
213 | } | |
214 | ||
215 | /* | |
216 | * Return the next free slob block pointer after this one. | |
217 | */ | |
218 | static slob_t *slob_next(slob_t *s) | |
219 | { | |
220 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
221 | slobidx_t next; | |
222 | ||
223 | if (s[0].units < 0) | |
224 | next = -s[0].units; | |
225 | else | |
226 | next = s[1].units; | |
227 | return base+next; | |
228 | } | |
229 | ||
230 | /* | |
231 | * Returns true if s is the last free block in its page. | |
232 | */ | |
233 | static int slob_last(slob_t *s) | |
234 | { | |
235 | return !((unsigned long)slob_next(s) & ~PAGE_MASK); | |
236 | } | |
237 | ||
238 | static void *slob_new_pages(gfp_t gfp, int order, int node) | |
239 | { | |
240 | void *page; | |
241 | ||
242 | #ifdef CONFIG_NUMA | |
243 | if (node != -1) | |
244 | page = alloc_pages_node(node, gfp, order); | |
245 | else | |
246 | #endif | |
247 | page = alloc_pages(gfp, order); | |
248 | ||
249 | if (!page) | |
250 | return NULL; | |
251 | ||
252 | return page_address(page); | |
253 | } | |
254 | ||
255 | static void slob_free_pages(void *b, int order) | |
256 | { | |
257 | free_pages((unsigned long)b, order); | |
258 | } | |
259 | ||
260 | /* | |
261 | * Allocate a slob block within a given slob_page sp. | |
262 | */ | |
263 | static void *slob_page_alloc(struct slob_page *sp, size_t size, int align) | |
264 | { | |
265 | slob_t *prev, *cur, *aligned = NULL; | |
266 | int delta = 0, units = SLOB_UNITS(size); | |
267 | ||
268 | for (prev = NULL, cur = sp->free; ; prev = cur, cur = slob_next(cur)) { | |
269 | slobidx_t avail = slob_units(cur); | |
270 | ||
271 | if (align) { | |
272 | aligned = (slob_t *)ALIGN((unsigned long)cur, align); | |
273 | delta = aligned - cur; | |
274 | } | |
275 | if (avail >= units + delta) { /* room enough? */ | |
276 | slob_t *next; | |
277 | ||
278 | if (delta) { /* need to fragment head to align? */ | |
279 | next = slob_next(cur); | |
280 | set_slob(aligned, avail - delta, next); | |
281 | set_slob(cur, delta, aligned); | |
282 | prev = cur; | |
283 | cur = aligned; | |
284 | avail = slob_units(cur); | |
285 | } | |
286 | ||
287 | next = slob_next(cur); | |
288 | if (avail == units) { /* exact fit? unlink. */ | |
289 | if (prev) | |
290 | set_slob(prev, slob_units(prev), next); | |
291 | else | |
292 | sp->free = next; | |
293 | } else { /* fragment */ | |
294 | if (prev) | |
295 | set_slob(prev, slob_units(prev), cur + units); | |
296 | else | |
297 | sp->free = cur + units; | |
298 | set_slob(cur + units, avail - units, next); | |
299 | } | |
300 | ||
301 | sp->units -= units; | |
302 | if (!sp->units) | |
303 | clear_slob_page_free(sp); | |
304 | return cur; | |
305 | } | |
306 | if (slob_last(cur)) | |
307 | return NULL; | |
308 | } | |
309 | } | |
310 | ||
311 | /* | |
312 | * slob_alloc: entry point into the slob allocator. | |
313 | */ | |
314 | static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) | |
315 | { | |
316 | struct slob_page *sp; | |
317 | struct list_head *prev; | |
318 | struct list_head *slob_list; | |
319 | slob_t *b = NULL; | |
320 | unsigned long flags; | |
321 | ||
322 | if (size < SLOB_BREAK1) | |
323 | slob_list = &free_slob_small; | |
324 | else if (size < SLOB_BREAK2) | |
325 | slob_list = &free_slob_medium; | |
326 | else | |
327 | slob_list = &free_slob_large; | |
328 | ||
329 | spin_lock_irqsave(&slob_lock, flags); | |
330 | /* Iterate through each partially free page, try to find room */ | |
331 | list_for_each_entry(sp, slob_list, list) { | |
332 | #ifdef CONFIG_NUMA | |
333 | /* | |
334 | * If there's a node specification, search for a partial | |
335 | * page with a matching node id in the freelist. | |
336 | */ | |
337 | if (node != -1 && page_to_nid(&sp->page) != node) | |
338 | continue; | |
339 | #endif | |
340 | /* Enough room on this page? */ | |
341 | if (sp->units < SLOB_UNITS(size)) | |
342 | continue; | |
343 | ||
344 | /* Attempt to alloc */ | |
345 | prev = sp->list.prev; | |
346 | b = slob_page_alloc(sp, size, align); | |
347 | if (!b) | |
348 | continue; | |
349 | ||
350 | /* Improve fragment distribution and reduce our average | |
351 | * search time by starting our next search here. (see | |
352 | * Knuth vol 1, sec 2.5, pg 449) */ | |
353 | if (prev != slob_list->prev && | |
354 | slob_list->next != prev->next) | |
355 | list_move_tail(slob_list, prev->next); | |
356 | break; | |
357 | } | |
358 | spin_unlock_irqrestore(&slob_lock, flags); | |
359 | ||
360 | /* Not enough space: must allocate a new page */ | |
361 | if (!b) { | |
362 | b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node); | |
363 | if (!b) | |
364 | return NULL; | |
365 | sp = slob_page(b); | |
366 | set_slob_page(sp); | |
367 | ||
368 | spin_lock_irqsave(&slob_lock, flags); | |
369 | sp->units = SLOB_UNITS(PAGE_SIZE); | |
370 | sp->free = b; | |
371 | INIT_LIST_HEAD(&sp->list); | |
372 | set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE)); | |
373 | set_slob_page_free(sp, slob_list); | |
374 | b = slob_page_alloc(sp, size, align); | |
375 | BUG_ON(!b); | |
376 | spin_unlock_irqrestore(&slob_lock, flags); | |
377 | } | |
378 | if (unlikely((gfp & __GFP_ZERO) && b)) | |
379 | memset(b, 0, size); | |
380 | return b; | |
381 | } | |
382 | ||
383 | /* | |
384 | * slob_free: entry point into the slob allocator. | |
385 | */ | |
386 | static void slob_free(void *block, int size) | |
387 | { | |
388 | struct slob_page *sp; | |
389 | slob_t *prev, *next, *b = (slob_t *)block; | |
390 | slobidx_t units; | |
391 | unsigned long flags; | |
392 | ||
393 | if (unlikely(ZERO_OR_NULL_PTR(block))) | |
394 | return; | |
395 | BUG_ON(!size); | |
396 | ||
397 | sp = slob_page(block); | |
398 | units = SLOB_UNITS(size); | |
399 | ||
400 | spin_lock_irqsave(&slob_lock, flags); | |
401 | ||
402 | if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) { | |
403 | /* Go directly to page allocator. Do not pass slob allocator */ | |
404 | if (slob_page_free(sp)) | |
405 | clear_slob_page_free(sp); | |
406 | spin_unlock_irqrestore(&slob_lock, flags); | |
407 | clear_slob_page(sp); | |
408 | free_slob_page(sp); | |
409 | free_page((unsigned long)b); | |
410 | return; | |
411 | } | |
412 | ||
413 | if (!slob_page_free(sp)) { | |
414 | /* This slob page is about to become partially free. Easy! */ | |
415 | sp->units = units; | |
416 | sp->free = b; | |
417 | set_slob(b, units, | |
418 | (void *)((unsigned long)(b + | |
419 | SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK)); | |
420 | set_slob_page_free(sp, &free_slob_small); | |
421 | goto out; | |
422 | } | |
423 | ||
424 | /* | |
425 | * Otherwise the page is already partially free, so find reinsertion | |
426 | * point. | |
427 | */ | |
428 | sp->units += units; | |
429 | ||
430 | if (b < sp->free) { | |
431 | if (b + units == sp->free) { | |
432 | units += slob_units(sp->free); | |
433 | sp->free = slob_next(sp->free); | |
434 | } | |
435 | set_slob(b, units, sp->free); | |
436 | sp->free = b; | |
437 | } else { | |
438 | prev = sp->free; | |
439 | next = slob_next(prev); | |
440 | while (b > next) { | |
441 | prev = next; | |
442 | next = slob_next(prev); | |
443 | } | |
444 | ||
445 | if (!slob_last(prev) && b + units == next) { | |
446 | units += slob_units(next); | |
447 | set_slob(b, units, slob_next(next)); | |
448 | } else | |
449 | set_slob(b, units, next); | |
450 | ||
451 | if (prev + slob_units(prev) == b) { | |
452 | units = slob_units(b) + slob_units(prev); | |
453 | set_slob(prev, units, slob_next(b)); | |
454 | } else | |
455 | set_slob(prev, slob_units(prev), b); | |
456 | } | |
457 | out: | |
458 | spin_unlock_irqrestore(&slob_lock, flags); | |
459 | } | |
460 | ||
461 | /* | |
462 | * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend. | |
463 | */ | |
464 | ||
465 | #ifndef ARCH_KMALLOC_MINALIGN | |
466 | #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long) | |
467 | #endif | |
468 | ||
469 | #ifndef ARCH_SLAB_MINALIGN | |
470 | #define ARCH_SLAB_MINALIGN __alignof__(unsigned long) | |
471 | #endif | |
472 | ||
473 | void *__kmalloc_node(size_t size, gfp_t gfp, int node) | |
474 | { | |
475 | unsigned int *m; | |
476 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); | |
477 | ||
478 | lockdep_trace_alloc(gfp); | |
479 | ||
480 | if (size < PAGE_SIZE - align) { | |
481 | if (!size) | |
482 | return ZERO_SIZE_PTR; | |
483 | ||
484 | m = slob_alloc(size + align, gfp, align, node); | |
485 | if (!m) | |
486 | return NULL; | |
487 | *m = size; | |
488 | return (void *)m + align; | |
489 | } else { | |
490 | void *ret; | |
491 | ||
492 | ret = slob_new_pages(gfp | __GFP_COMP, get_order(size), node); | |
493 | if (ret) { | |
494 | struct page *page; | |
495 | page = virt_to_page(ret); | |
496 | page->private = size; | |
497 | } | |
498 | return ret; | |
499 | } | |
500 | } | |
501 | EXPORT_SYMBOL(__kmalloc_node); | |
502 | ||
503 | void kfree(const void *block) | |
504 | { | |
505 | struct slob_page *sp; | |
506 | ||
507 | if (unlikely(ZERO_OR_NULL_PTR(block))) | |
508 | return; | |
509 | ||
510 | sp = slob_page(block); | |
511 | if (is_slob_page(sp)) { | |
512 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); | |
513 | unsigned int *m = (unsigned int *)(block - align); | |
514 | slob_free(m, *m + align); | |
515 | } else | |
516 | put_page(&sp->page); | |
517 | } | |
518 | EXPORT_SYMBOL(kfree); | |
519 | ||
520 | /* can't use ksize for kmem_cache_alloc memory, only kmalloc */ | |
521 | size_t ksize(const void *block) | |
522 | { | |
523 | struct slob_page *sp; | |
524 | ||
525 | BUG_ON(!block); | |
526 | if (unlikely(block == ZERO_SIZE_PTR)) | |
527 | return 0; | |
528 | ||
529 | sp = slob_page(block); | |
530 | if (is_slob_page(sp)) { | |
531 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); | |
532 | unsigned int *m = (unsigned int *)(block - align); | |
533 | return SLOB_UNITS(*m) * SLOB_UNIT; | |
534 | } else | |
535 | return sp->page.private; | |
536 | } | |
537 | EXPORT_SYMBOL(ksize); | |
538 | ||
539 | struct kmem_cache { | |
540 | unsigned int size, align; | |
541 | unsigned long flags; | |
542 | const char *name; | |
543 | void (*ctor)(void *); | |
544 | }; | |
545 | ||
546 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |
547 | size_t align, unsigned long flags, void (*ctor)(void *)) | |
548 | { | |
549 | struct kmem_cache *c; | |
550 | ||
551 | c = slob_alloc(sizeof(struct kmem_cache), | |
552 | GFP_KERNEL, ARCH_KMALLOC_MINALIGN, -1); | |
553 | ||
554 | if (c) { | |
555 | c->name = name; | |
556 | c->size = size; | |
557 | if (flags & SLAB_DESTROY_BY_RCU) { | |
558 | /* leave room for rcu footer at the end of object */ | |
559 | c->size += sizeof(struct slob_rcu); | |
560 | } | |
561 | c->flags = flags; | |
562 | c->ctor = ctor; | |
563 | /* ignore alignment unless it's forced */ | |
564 | c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0; | |
565 | if (c->align < ARCH_SLAB_MINALIGN) | |
566 | c->align = ARCH_SLAB_MINALIGN; | |
567 | if (c->align < align) | |
568 | c->align = align; | |
569 | } else if (flags & SLAB_PANIC) | |
570 | panic("Cannot create slab cache %s\n", name); | |
571 | ||
572 | return c; | |
573 | } | |
574 | EXPORT_SYMBOL(kmem_cache_create); | |
575 | ||
576 | void kmem_cache_destroy(struct kmem_cache *c) | |
577 | { | |
578 | slob_free(c, sizeof(struct kmem_cache)); | |
579 | } | |
580 | EXPORT_SYMBOL(kmem_cache_destroy); | |
581 | ||
582 | void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node) | |
583 | { | |
584 | void *b; | |
585 | ||
586 | if (c->size < PAGE_SIZE) | |
587 | b = slob_alloc(c->size, flags, c->align, node); | |
588 | else | |
589 | b = slob_new_pages(flags, get_order(c->size), node); | |
590 | ||
591 | if (c->ctor) | |
592 | c->ctor(b); | |
593 | ||
594 | return b; | |
595 | } | |
596 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
597 | ||
598 | static void __kmem_cache_free(void *b, int size) | |
599 | { | |
600 | if (size < PAGE_SIZE) | |
601 | slob_free(b, size); | |
602 | else | |
603 | slob_free_pages(b, get_order(size)); | |
604 | } | |
605 | ||
606 | static void kmem_rcu_free(struct rcu_head *head) | |
607 | { | |
608 | struct slob_rcu *slob_rcu = (struct slob_rcu *)head; | |
609 | void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu)); | |
610 | ||
611 | __kmem_cache_free(b, slob_rcu->size); | |
612 | } | |
613 | ||
614 | void kmem_cache_free(struct kmem_cache *c, void *b) | |
615 | { | |
616 | if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) { | |
617 | struct slob_rcu *slob_rcu; | |
618 | slob_rcu = b + (c->size - sizeof(struct slob_rcu)); | |
619 | INIT_RCU_HEAD(&slob_rcu->head); | |
620 | slob_rcu->size = c->size; | |
621 | call_rcu(&slob_rcu->head, kmem_rcu_free); | |
622 | } else { | |
623 | __kmem_cache_free(b, c->size); | |
624 | } | |
625 | } | |
626 | EXPORT_SYMBOL(kmem_cache_free); | |
627 | ||
628 | unsigned int kmem_cache_size(struct kmem_cache *c) | |
629 | { | |
630 | return c->size; | |
631 | } | |
632 | EXPORT_SYMBOL(kmem_cache_size); | |
633 | ||
634 | const char *kmem_cache_name(struct kmem_cache *c) | |
635 | { | |
636 | return c->name; | |
637 | } | |
638 | EXPORT_SYMBOL(kmem_cache_name); | |
639 | ||
640 | int kmem_cache_shrink(struct kmem_cache *d) | |
641 | { | |
642 | return 0; | |
643 | } | |
644 | EXPORT_SYMBOL(kmem_cache_shrink); | |
645 | ||
646 | int kmem_ptr_validate(struct kmem_cache *a, const void *b) | |
647 | { | |
648 | return 0; | |
649 | } | |
650 | ||
651 | static unsigned int slob_ready __read_mostly; | |
652 | ||
653 | int slab_is_available(void) | |
654 | { | |
655 | return slob_ready; | |
656 | } | |
657 | ||
658 | void __init kmem_cache_init(void) | |
659 | { | |
660 | slob_ready = 1; | |
661 | } |