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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_exact_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/swap.h> /* struct reclaim_state */ | |
64 | #include <linux/cache.h> | |
65 | #include <linux/init.h> | |
66 | #include <linux/module.h> | |
67 | #include <linux/rcupdate.h> | |
68 | #include <linux/list.h> | |
69 | #include <linux/kmemleak.h> | |
70 | ||
71 | #include <trace/events/kmem.h> | |
72 | ||
73 | #include <asm/atomic.h> | |
74 | ||
75 | /* | |
76 | * slob_block has a field 'units', which indicates size of block if +ve, | |
77 | * or offset of next block if -ve (in SLOB_UNITs). | |
78 | * | |
79 | * Free blocks of size 1 unit simply contain the offset of the next block. | |
80 | * Those with larger size contain their size in the first SLOB_UNIT of | |
81 | * memory, and the offset of the next free block in the second SLOB_UNIT. | |
82 | */ | |
83 | #if PAGE_SIZE <= (32767 * 2) | |
84 | typedef s16 slobidx_t; | |
85 | #else | |
86 | typedef s32 slobidx_t; | |
87 | #endif | |
88 | ||
89 | struct slob_block { | |
90 | slobidx_t units; | |
91 | }; | |
92 | typedef struct slob_block slob_t; | |
93 | ||
94 | /* | |
95 | * We use struct page fields to manage some slob allocation aspects, | |
96 | * however to avoid the horrible mess in include/linux/mm_types.h, we'll | |
97 | * just define our own struct page type variant here. | |
98 | */ | |
99 | struct slob_page { | |
100 | union { | |
101 | struct { | |
102 | unsigned long flags; /* mandatory */ | |
103 | atomic_t _count; /* mandatory */ | |
104 | slobidx_t units; /* free units left in page */ | |
105 | unsigned long pad[2]; | |
106 | slob_t *free; /* first free slob_t in page */ | |
107 | struct list_head list; /* linked list of free pages */ | |
108 | }; | |
109 | struct page page; | |
110 | }; | |
111 | }; | |
112 | static inline void struct_slob_page_wrong_size(void) | |
113 | { BUILD_BUG_ON(sizeof(struct slob_page) != sizeof(struct page)); } | |
114 | ||
115 | /* | |
116 | * free_slob_page: call before a slob_page is returned to the page allocator. | |
117 | */ | |
118 | static inline void free_slob_page(struct slob_page *sp) | |
119 | { | |
120 | reset_page_mapcount(&sp->page); | |
121 | sp->page.mapping = NULL; | |
122 | } | |
123 | ||
124 | /* | |
125 | * All partially free slob pages go on these lists. | |
126 | */ | |
127 | #define SLOB_BREAK1 256 | |
128 | #define SLOB_BREAK2 1024 | |
129 | static LIST_HEAD(free_slob_small); | |
130 | static LIST_HEAD(free_slob_medium); | |
131 | static LIST_HEAD(free_slob_large); | |
132 | ||
133 | /* | |
134 | * is_slob_page: True for all slob pages (false for bigblock pages) | |
135 | */ | |
136 | static inline int is_slob_page(struct slob_page *sp) | |
137 | { | |
138 | return PageSlab((struct page *)sp); | |
139 | } | |
140 | ||
141 | static inline void set_slob_page(struct slob_page *sp) | |
142 | { | |
143 | __SetPageSlab((struct page *)sp); | |
144 | } | |
145 | ||
146 | static inline void clear_slob_page(struct slob_page *sp) | |
147 | { | |
148 | __ClearPageSlab((struct page *)sp); | |
149 | } | |
150 | ||
151 | static inline struct slob_page *slob_page(const void *addr) | |
152 | { | |
153 | return (struct slob_page *)virt_to_page(addr); | |
154 | } | |
155 | ||
156 | /* | |
157 | * slob_page_free: true for pages on free_slob_pages list. | |
158 | */ | |
159 | static inline int slob_page_free(struct slob_page *sp) | |
160 | { | |
161 | return PageSlobFree((struct page *)sp); | |
162 | } | |
163 | ||
164 | static void set_slob_page_free(struct slob_page *sp, struct list_head *list) | |
165 | { | |
166 | list_add(&sp->list, list); | |
167 | __SetPageSlobFree((struct page *)sp); | |
168 | } | |
169 | ||
170 | static inline void clear_slob_page_free(struct slob_page *sp) | |
171 | { | |
172 | list_del(&sp->list); | |
173 | __ClearPageSlobFree((struct page *)sp); | |
174 | } | |
175 | ||
176 | #define SLOB_UNIT sizeof(slob_t) | |
177 | #define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT) | |
178 | #define SLOB_ALIGN L1_CACHE_BYTES | |
179 | ||
180 | /* | |
181 | * struct slob_rcu is inserted at the tail of allocated slob blocks, which | |
182 | * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free | |
183 | * the block using call_rcu. | |
184 | */ | |
185 | struct slob_rcu { | |
186 | struct rcu_head head; | |
187 | int size; | |
188 | }; | |
189 | ||
190 | /* | |
191 | * slob_lock protects all slob allocator structures. | |
192 | */ | |
193 | static DEFINE_SPINLOCK(slob_lock); | |
194 | ||
195 | /* | |
196 | * Encode the given size and next info into a free slob block s. | |
197 | */ | |
198 | static void set_slob(slob_t *s, slobidx_t size, slob_t *next) | |
199 | { | |
200 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
201 | slobidx_t offset = next - base; | |
202 | ||
203 | if (size > 1) { | |
204 | s[0].units = size; | |
205 | s[1].units = offset; | |
206 | } else | |
207 | s[0].units = -offset; | |
208 | } | |
209 | ||
210 | /* | |
211 | * Return the size of a slob block. | |
212 | */ | |
213 | static slobidx_t slob_units(slob_t *s) | |
214 | { | |
215 | if (s->units > 0) | |
216 | return s->units; | |
217 | return 1; | |
218 | } | |
219 | ||
220 | /* | |
221 | * Return the next free slob block pointer after this one. | |
222 | */ | |
223 | static slob_t *slob_next(slob_t *s) | |
224 | { | |
225 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
226 | slobidx_t next; | |
227 | ||
228 | if (s[0].units < 0) | |
229 | next = -s[0].units; | |
230 | else | |
231 | next = s[1].units; | |
232 | return base+next; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Returns true if s is the last free block in its page. | |
237 | */ | |
238 | static int slob_last(slob_t *s) | |
239 | { | |
240 | return !((unsigned long)slob_next(s) & ~PAGE_MASK); | |
241 | } | |
242 | ||
243 | static void *slob_new_pages(gfp_t gfp, int order, int node) | |
244 | { | |
245 | void *page; | |
246 | ||
247 | #ifdef CONFIG_NUMA | |
248 | if (node != -1) | |
249 | page = alloc_pages_exact_node(node, gfp, order); | |
250 | else | |
251 | #endif | |
252 | page = alloc_pages(gfp, order); | |
253 | ||
254 | if (!page) | |
255 | return NULL; | |
256 | ||
257 | return page_address(page); | |
258 | } | |
259 | ||
260 | static void slob_free_pages(void *b, int order) | |
261 | { | |
262 | if (current->reclaim_state) | |
263 | current->reclaim_state->reclaimed_slab += 1 << order; | |
264 | free_pages((unsigned long)b, order); | |
265 | } | |
266 | ||
267 | /* | |
268 | * Allocate a slob block within a given slob_page sp. | |
269 | */ | |
270 | static void *slob_page_alloc(struct slob_page *sp, size_t size, int align) | |
271 | { | |
272 | slob_t *prev, *cur, *aligned = NULL; | |
273 | int delta = 0, units = SLOB_UNITS(size); | |
274 | ||
275 | for (prev = NULL, cur = sp->free; ; prev = cur, cur = slob_next(cur)) { | |
276 | slobidx_t avail = slob_units(cur); | |
277 | ||
278 | if (align) { | |
279 | aligned = (slob_t *)ALIGN((unsigned long)cur, align); | |
280 | delta = aligned - cur; | |
281 | } | |
282 | if (avail >= units + delta) { /* room enough? */ | |
283 | slob_t *next; | |
284 | ||
285 | if (delta) { /* need to fragment head to align? */ | |
286 | next = slob_next(cur); | |
287 | set_slob(aligned, avail - delta, next); | |
288 | set_slob(cur, delta, aligned); | |
289 | prev = cur; | |
290 | cur = aligned; | |
291 | avail = slob_units(cur); | |
292 | } | |
293 | ||
294 | next = slob_next(cur); | |
295 | if (avail == units) { /* exact fit? unlink. */ | |
296 | if (prev) | |
297 | set_slob(prev, slob_units(prev), next); | |
298 | else | |
299 | sp->free = next; | |
300 | } else { /* fragment */ | |
301 | if (prev) | |
302 | set_slob(prev, slob_units(prev), cur + units); | |
303 | else | |
304 | sp->free = cur + units; | |
305 | set_slob(cur + units, avail - units, next); | |
306 | } | |
307 | ||
308 | sp->units -= units; | |
309 | if (!sp->units) | |
310 | clear_slob_page_free(sp); | |
311 | return cur; | |
312 | } | |
313 | if (slob_last(cur)) | |
314 | return NULL; | |
315 | } | |
316 | } | |
317 | ||
318 | /* | |
319 | * slob_alloc: entry point into the slob allocator. | |
320 | */ | |
321 | static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) | |
322 | { | |
323 | struct slob_page *sp; | |
324 | struct list_head *prev; | |
325 | struct list_head *slob_list; | |
326 | slob_t *b = NULL; | |
327 | unsigned long flags; | |
328 | ||
329 | if (size < SLOB_BREAK1) | |
330 | slob_list = &free_slob_small; | |
331 | else if (size < SLOB_BREAK2) | |
332 | slob_list = &free_slob_medium; | |
333 | else | |
334 | slob_list = &free_slob_large; | |
335 | ||
336 | spin_lock_irqsave(&slob_lock, flags); | |
337 | /* Iterate through each partially free page, try to find room */ | |
338 | list_for_each_entry(sp, slob_list, list) { | |
339 | #ifdef CONFIG_NUMA | |
340 | /* | |
341 | * If there's a node specification, search for a partial | |
342 | * page with a matching node id in the freelist. | |
343 | */ | |
344 | if (node != -1 && page_to_nid(&sp->page) != node) | |
345 | continue; | |
346 | #endif | |
347 | /* Enough room on this page? */ | |
348 | if (sp->units < SLOB_UNITS(size)) | |
349 | continue; | |
350 | ||
351 | /* Attempt to alloc */ | |
352 | prev = sp->list.prev; | |
353 | b = slob_page_alloc(sp, size, align); | |
354 | if (!b) | |
355 | continue; | |
356 | ||
357 | /* Improve fragment distribution and reduce our average | |
358 | * search time by starting our next search here. (see | |
359 | * Knuth vol 1, sec 2.5, pg 449) */ | |
360 | if (prev != slob_list->prev && | |
361 | slob_list->next != prev->next) | |
362 | list_move_tail(slob_list, prev->next); | |
363 | break; | |
364 | } | |
365 | spin_unlock_irqrestore(&slob_lock, flags); | |
366 | ||
367 | /* Not enough space: must allocate a new page */ | |
368 | if (!b) { | |
369 | b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node); | |
370 | if (!b) | |
371 | return NULL; | |
372 | sp = slob_page(b); | |
373 | set_slob_page(sp); | |
374 | ||
375 | spin_lock_irqsave(&slob_lock, flags); | |
376 | sp->units = SLOB_UNITS(PAGE_SIZE); | |
377 | sp->free = b; | |
378 | INIT_LIST_HEAD(&sp->list); | |
379 | set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE)); | |
380 | set_slob_page_free(sp, slob_list); | |
381 | b = slob_page_alloc(sp, size, align); | |
382 | BUG_ON(!b); | |
383 | spin_unlock_irqrestore(&slob_lock, flags); | |
384 | } | |
385 | if (unlikely((gfp & __GFP_ZERO) && b)) | |
386 | memset(b, 0, size); | |
387 | return b; | |
388 | } | |
389 | ||
390 | /* | |
391 | * slob_free: entry point into the slob allocator. | |
392 | */ | |
393 | static void slob_free(void *block, int size) | |
394 | { | |
395 | struct slob_page *sp; | |
396 | slob_t *prev, *next, *b = (slob_t *)block; | |
397 | slobidx_t units; | |
398 | unsigned long flags; | |
399 | struct list_head *slob_list; | |
400 | ||
401 | if (unlikely(ZERO_OR_NULL_PTR(block))) | |
402 | return; | |
403 | BUG_ON(!size); | |
404 | ||
405 | sp = slob_page(block); | |
406 | units = SLOB_UNITS(size); | |
407 | ||
408 | spin_lock_irqsave(&slob_lock, flags); | |
409 | ||
410 | if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) { | |
411 | /* Go directly to page allocator. Do not pass slob allocator */ | |
412 | if (slob_page_free(sp)) | |
413 | clear_slob_page_free(sp); | |
414 | spin_unlock_irqrestore(&slob_lock, flags); | |
415 | clear_slob_page(sp); | |
416 | free_slob_page(sp); | |
417 | slob_free_pages(b, 0); | |
418 | return; | |
419 | } | |
420 | ||
421 | if (!slob_page_free(sp)) { | |
422 | /* This slob page is about to become partially free. Easy! */ | |
423 | sp->units = units; | |
424 | sp->free = b; | |
425 | set_slob(b, units, | |
426 | (void *)((unsigned long)(b + | |
427 | SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK)); | |
428 | if (size < SLOB_BREAK1) | |
429 | slob_list = &free_slob_small; | |
430 | else if (size < SLOB_BREAK2) | |
431 | slob_list = &free_slob_medium; | |
432 | else | |
433 | slob_list = &free_slob_large; | |
434 | set_slob_page_free(sp, slob_list); | |
435 | goto out; | |
436 | } | |
437 | ||
438 | /* | |
439 | * Otherwise the page is already partially free, so find reinsertion | |
440 | * point. | |
441 | */ | |
442 | sp->units += units; | |
443 | ||
444 | if (b < sp->free) { | |
445 | if (b + units == sp->free) { | |
446 | units += slob_units(sp->free); | |
447 | sp->free = slob_next(sp->free); | |
448 | } | |
449 | set_slob(b, units, sp->free); | |
450 | sp->free = b; | |
451 | } else { | |
452 | prev = sp->free; | |
453 | next = slob_next(prev); | |
454 | while (b > next) { | |
455 | prev = next; | |
456 | next = slob_next(prev); | |
457 | } | |
458 | ||
459 | if (!slob_last(prev) && b + units == next) { | |
460 | units += slob_units(next); | |
461 | set_slob(b, units, slob_next(next)); | |
462 | } else | |
463 | set_slob(b, units, next); | |
464 | ||
465 | if (prev + slob_units(prev) == b) { | |
466 | units = slob_units(b) + slob_units(prev); | |
467 | set_slob(prev, units, slob_next(b)); | |
468 | } else | |
469 | set_slob(prev, slob_units(prev), b); | |
470 | } | |
471 | out: | |
472 | spin_unlock_irqrestore(&slob_lock, flags); | |
473 | } | |
474 | ||
475 | /* | |
476 | * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend. | |
477 | */ | |
478 | ||
479 | void *__kmalloc_node(size_t size, gfp_t gfp, int node) | |
480 | { | |
481 | unsigned int *m; | |
482 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); | |
483 | void *ret; | |
484 | ||
485 | lockdep_trace_alloc(gfp); | |
486 | ||
487 | if (size < PAGE_SIZE - align) { | |
488 | if (!size) | |
489 | return ZERO_SIZE_PTR; | |
490 | ||
491 | m = slob_alloc(size + align, gfp, align, node); | |
492 | ||
493 | if (!m) | |
494 | return NULL; | |
495 | *m = size; | |
496 | ret = (void *)m + align; | |
497 | ||
498 | trace_kmalloc_node(_RET_IP_, ret, | |
499 | size, size + align, gfp, node); | |
500 | } else { | |
501 | unsigned int order = get_order(size); | |
502 | ||
503 | if (likely(order)) | |
504 | gfp |= __GFP_COMP; | |
505 | ret = slob_new_pages(gfp, order, node); | |
506 | if (ret) { | |
507 | struct page *page; | |
508 | page = virt_to_page(ret); | |
509 | page->private = size; | |
510 | } | |
511 | ||
512 | trace_kmalloc_node(_RET_IP_, ret, | |
513 | size, PAGE_SIZE << order, gfp, node); | |
514 | } | |
515 | ||
516 | kmemleak_alloc(ret, size, 1, gfp); | |
517 | return ret; | |
518 | } | |
519 | EXPORT_SYMBOL(__kmalloc_node); | |
520 | ||
521 | void kfree(const void *block) | |
522 | { | |
523 | struct slob_page *sp; | |
524 | ||
525 | trace_kfree(_RET_IP_, block); | |
526 | ||
527 | if (unlikely(ZERO_OR_NULL_PTR(block))) | |
528 | return; | |
529 | kmemleak_free(block); | |
530 | ||
531 | sp = slob_page(block); | |
532 | if (is_slob_page(sp)) { | |
533 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); | |
534 | unsigned int *m = (unsigned int *)(block - align); | |
535 | slob_free(m, *m + align); | |
536 | } else | |
537 | put_page(&sp->page); | |
538 | } | |
539 | EXPORT_SYMBOL(kfree); | |
540 | ||
541 | /* can't use ksize for kmem_cache_alloc memory, only kmalloc */ | |
542 | size_t ksize(const void *block) | |
543 | { | |
544 | struct slob_page *sp; | |
545 | ||
546 | BUG_ON(!block); | |
547 | if (unlikely(block == ZERO_SIZE_PTR)) | |
548 | return 0; | |
549 | ||
550 | sp = slob_page(block); | |
551 | if (is_slob_page(sp)) { | |
552 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); | |
553 | unsigned int *m = (unsigned int *)(block - align); | |
554 | return SLOB_UNITS(*m) * SLOB_UNIT; | |
555 | } else | |
556 | return sp->page.private; | |
557 | } | |
558 | EXPORT_SYMBOL(ksize); | |
559 | ||
560 | struct kmem_cache { | |
561 | unsigned int size, align; | |
562 | unsigned long flags; | |
563 | const char *name; | |
564 | void (*ctor)(void *); | |
565 | }; | |
566 | ||
567 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |
568 | size_t align, unsigned long flags, void (*ctor)(void *)) | |
569 | { | |
570 | struct kmem_cache *c; | |
571 | ||
572 | c = slob_alloc(sizeof(struct kmem_cache), | |
573 | GFP_KERNEL, ARCH_KMALLOC_MINALIGN, -1); | |
574 | ||
575 | if (c) { | |
576 | c->name = name; | |
577 | c->size = size; | |
578 | if (flags & SLAB_DESTROY_BY_RCU) { | |
579 | /* leave room for rcu footer at the end of object */ | |
580 | c->size += sizeof(struct slob_rcu); | |
581 | } | |
582 | c->flags = flags; | |
583 | c->ctor = ctor; | |
584 | /* ignore alignment unless it's forced */ | |
585 | c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0; | |
586 | if (c->align < ARCH_SLAB_MINALIGN) | |
587 | c->align = ARCH_SLAB_MINALIGN; | |
588 | if (c->align < align) | |
589 | c->align = align; | |
590 | } else if (flags & SLAB_PANIC) | |
591 | panic("Cannot create slab cache %s\n", name); | |
592 | ||
593 | kmemleak_alloc(c, sizeof(struct kmem_cache), 1, GFP_KERNEL); | |
594 | return c; | |
595 | } | |
596 | EXPORT_SYMBOL(kmem_cache_create); | |
597 | ||
598 | void kmem_cache_destroy(struct kmem_cache *c) | |
599 | { | |
600 | kmemleak_free(c); | |
601 | if (c->flags & SLAB_DESTROY_BY_RCU) | |
602 | rcu_barrier(); | |
603 | slob_free(c, sizeof(struct kmem_cache)); | |
604 | } | |
605 | EXPORT_SYMBOL(kmem_cache_destroy); | |
606 | ||
607 | void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node) | |
608 | { | |
609 | void *b; | |
610 | ||
611 | if (c->size < PAGE_SIZE) { | |
612 | b = slob_alloc(c->size, flags, c->align, node); | |
613 | trace_kmem_cache_alloc_node(_RET_IP_, b, c->size, | |
614 | SLOB_UNITS(c->size) * SLOB_UNIT, | |
615 | flags, node); | |
616 | } else { | |
617 | b = slob_new_pages(flags, get_order(c->size), node); | |
618 | trace_kmem_cache_alloc_node(_RET_IP_, b, c->size, | |
619 | PAGE_SIZE << get_order(c->size), | |
620 | flags, node); | |
621 | } | |
622 | ||
623 | if (c->ctor) | |
624 | c->ctor(b); | |
625 | ||
626 | kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags); | |
627 | return b; | |
628 | } | |
629 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
630 | ||
631 | static void __kmem_cache_free(void *b, int size) | |
632 | { | |
633 | if (size < PAGE_SIZE) | |
634 | slob_free(b, size); | |
635 | else | |
636 | slob_free_pages(b, get_order(size)); | |
637 | } | |
638 | ||
639 | static void kmem_rcu_free(struct rcu_head *head) | |
640 | { | |
641 | struct slob_rcu *slob_rcu = (struct slob_rcu *)head; | |
642 | void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu)); | |
643 | ||
644 | __kmem_cache_free(b, slob_rcu->size); | |
645 | } | |
646 | ||
647 | void kmem_cache_free(struct kmem_cache *c, void *b) | |
648 | { | |
649 | kmemleak_free_recursive(b, c->flags); | |
650 | if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) { | |
651 | struct slob_rcu *slob_rcu; | |
652 | slob_rcu = b + (c->size - sizeof(struct slob_rcu)); | |
653 | slob_rcu->size = c->size; | |
654 | call_rcu(&slob_rcu->head, kmem_rcu_free); | |
655 | } else { | |
656 | __kmem_cache_free(b, c->size); | |
657 | } | |
658 | ||
659 | trace_kmem_cache_free(_RET_IP_, b); | |
660 | } | |
661 | EXPORT_SYMBOL(kmem_cache_free); | |
662 | ||
663 | unsigned int kmem_cache_size(struct kmem_cache *c) | |
664 | { | |
665 | return c->size; | |
666 | } | |
667 | EXPORT_SYMBOL(kmem_cache_size); | |
668 | ||
669 | const char *kmem_cache_name(struct kmem_cache *c) | |
670 | { | |
671 | return c->name; | |
672 | } | |
673 | EXPORT_SYMBOL(kmem_cache_name); | |
674 | ||
675 | int kmem_cache_shrink(struct kmem_cache *d) | |
676 | { | |
677 | return 0; | |
678 | } | |
679 | EXPORT_SYMBOL(kmem_cache_shrink); | |
680 | ||
681 | int kmem_ptr_validate(struct kmem_cache *a, const void *b) | |
682 | { | |
683 | return 0; | |
684 | } | |
685 | ||
686 | static unsigned int slob_ready __read_mostly; | |
687 | ||
688 | int slab_is_available(void) | |
689 | { | |
690 | return slob_ready; | |
691 | } | |
692 | ||
693 | void __init kmem_cache_init(void) | |
694 | { | |
695 | slob_ready = 1; | |
696 | } | |
697 | ||
698 | void __init kmem_cache_init_late(void) | |
699 | { | |
700 | /* Nothing to do */ | |
701 | } |