Commit | Line | Data |
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10cef602 MM |
1 | /* |
2 | * SLOB Allocator: Simple List Of Blocks | |
3 | * | |
4 | * Matt Mackall <mpm@selenic.com> 12/30/03 | |
5 | * | |
6193a2ff PM |
6 | * NUMA support by Paul Mundt, 2007. |
7 | * | |
10cef602 MM |
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 | |
55394849 NP |
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. | |
95b35127 | 14 | * |
20cecbae MM |
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. | |
10cef602 MM |
26 | * |
27 | * Above this is an implementation of kmalloc/kfree. Blocks returned | |
55394849 | 28 | * from kmalloc are prepended with a 4-byte header with the kmalloc size. |
10cef602 | 29 | * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls |
6193a2ff | 30 | * alloc_pages() directly, allocating compound pages so the page order |
d87a133f NP |
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. | |
10cef602 MM |
35 | * |
36 | * SLAB is emulated on top of SLOB by simply calling constructors and | |
95b35127 NP |
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 | |
6193a2ff | 41 | * calling alloc_pages(). As SLAB objects know their size, no separate |
95b35127 | 42 | * size bookkeeping is necessary and there is essentially no allocation |
d87a133f NP |
43 | * space overhead, and compound pages aren't needed for multi-page |
44 | * allocations. | |
6193a2ff PM |
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 | |
6484eb3e | 49 | * provided, alloc_pages_exact_node() with the specified node id is used |
6193a2ff PM |
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. | |
10cef602 MM |
58 | */ |
59 | ||
95b35127 | 60 | #include <linux/kernel.h> |
10cef602 MM |
61 | #include <linux/slab.h> |
62 | #include <linux/mm.h> | |
1f0532eb | 63 | #include <linux/swap.h> /* struct reclaim_state */ |
10cef602 MM |
64 | #include <linux/cache.h> |
65 | #include <linux/init.h> | |
b95f1b31 | 66 | #include <linux/export.h> |
afc0cedb | 67 | #include <linux/rcupdate.h> |
95b35127 | 68 | #include <linux/list.h> |
4374e616 | 69 | #include <linux/kmemleak.h> |
039ca4e7 LZ |
70 | |
71 | #include <trace/events/kmem.h> | |
72 | ||
60063497 | 73 | #include <linux/atomic.h> |
95b35127 | 74 | |
95b35127 NP |
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 | */ | |
55394849 | 83 | #if PAGE_SIZE <= (32767 * 2) |
95b35127 NP |
84 | typedef s16 slobidx_t; |
85 | #else | |
86 | typedef s32 slobidx_t; | |
87 | #endif | |
88 | ||
10cef602 | 89 | struct slob_block { |
95b35127 | 90 | slobidx_t units; |
55394849 | 91 | }; |
10cef602 MM |
92 | typedef struct slob_block slob_t; |
93 | ||
95b35127 NP |
94 | /* |
95 | * free_slob_page: call before a slob_page is returned to the page allocator. | |
96 | */ | |
b8c24c4a | 97 | static inline void free_slob_page(struct page *sp) |
95b35127 | 98 | { |
b8c24c4a CL |
99 | reset_page_mapcount(sp); |
100 | sp->mapping = NULL; | |
95b35127 NP |
101 | } |
102 | ||
103 | /* | |
20cecbae | 104 | * All partially free slob pages go on these lists. |
95b35127 | 105 | */ |
20cecbae MM |
106 | #define SLOB_BREAK1 256 |
107 | #define SLOB_BREAK2 1024 | |
108 | static LIST_HEAD(free_slob_small); | |
109 | static LIST_HEAD(free_slob_medium); | |
110 | static LIST_HEAD(free_slob_large); | |
95b35127 NP |
111 | |
112 | /* | |
6e9ed0cc | 113 | * is_slob_page: True for all slob pages (false for bigblock pages) |
95b35127 | 114 | */ |
b8c24c4a | 115 | static inline int is_slob_page(struct page *sp) |
95b35127 | 116 | { |
b8c24c4a | 117 | return PageSlab(sp); |
95b35127 NP |
118 | } |
119 | ||
b8c24c4a | 120 | static inline void set_slob_page(struct page *sp) |
95b35127 | 121 | { |
b8c24c4a | 122 | __SetPageSlab(sp); |
95b35127 NP |
123 | } |
124 | ||
b8c24c4a | 125 | static inline void clear_slob_page(struct page *sp) |
95b35127 | 126 | { |
b8c24c4a | 127 | __ClearPageSlab(sp); |
95b35127 NP |
128 | } |
129 | ||
b8c24c4a | 130 | static inline struct page *slob_page(const void *addr) |
6e9ed0cc | 131 | { |
b8c24c4a | 132 | return virt_to_page(addr); |
6e9ed0cc AW |
133 | } |
134 | ||
95b35127 NP |
135 | /* |
136 | * slob_page_free: true for pages on free_slob_pages list. | |
137 | */ | |
b8c24c4a | 138 | static inline int slob_page_free(struct page *sp) |
95b35127 | 139 | { |
b8c24c4a | 140 | return PageSlobFree(sp); |
95b35127 NP |
141 | } |
142 | ||
b8c24c4a | 143 | static void set_slob_page_free(struct page *sp, struct list_head *list) |
95b35127 | 144 | { |
20cecbae | 145 | list_add(&sp->list, list); |
b8c24c4a | 146 | __SetPageSlobFree(sp); |
95b35127 NP |
147 | } |
148 | ||
b8c24c4a | 149 | static inline void clear_slob_page_free(struct page *sp) |
95b35127 NP |
150 | { |
151 | list_del(&sp->list); | |
b8c24c4a | 152 | __ClearPageSlobFree(sp); |
95b35127 NP |
153 | } |
154 | ||
10cef602 MM |
155 | #define SLOB_UNIT sizeof(slob_t) |
156 | #define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT) | |
157 | #define SLOB_ALIGN L1_CACHE_BYTES | |
158 | ||
afc0cedb NP |
159 | /* |
160 | * struct slob_rcu is inserted at the tail of allocated slob blocks, which | |
161 | * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free | |
162 | * the block using call_rcu. | |
163 | */ | |
164 | struct slob_rcu { | |
165 | struct rcu_head head; | |
166 | int size; | |
167 | }; | |
168 | ||
95b35127 NP |
169 | /* |
170 | * slob_lock protects all slob allocator structures. | |
171 | */ | |
10cef602 | 172 | static DEFINE_SPINLOCK(slob_lock); |
10cef602 | 173 | |
95b35127 NP |
174 | /* |
175 | * Encode the given size and next info into a free slob block s. | |
176 | */ | |
177 | static void set_slob(slob_t *s, slobidx_t size, slob_t *next) | |
178 | { | |
179 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
180 | slobidx_t offset = next - base; | |
bcb4ddb4 | 181 | |
95b35127 NP |
182 | if (size > 1) { |
183 | s[0].units = size; | |
184 | s[1].units = offset; | |
185 | } else | |
186 | s[0].units = -offset; | |
187 | } | |
10cef602 | 188 | |
95b35127 NP |
189 | /* |
190 | * Return the size of a slob block. | |
191 | */ | |
192 | static slobidx_t slob_units(slob_t *s) | |
193 | { | |
194 | if (s->units > 0) | |
195 | return s->units; | |
196 | return 1; | |
197 | } | |
198 | ||
199 | /* | |
200 | * Return the next free slob block pointer after this one. | |
201 | */ | |
202 | static slob_t *slob_next(slob_t *s) | |
203 | { | |
204 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
205 | slobidx_t next; | |
206 | ||
207 | if (s[0].units < 0) | |
208 | next = -s[0].units; | |
209 | else | |
210 | next = s[1].units; | |
211 | return base+next; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Returns true if s is the last free block in its page. | |
216 | */ | |
217 | static int slob_last(slob_t *s) | |
218 | { | |
219 | return !((unsigned long)slob_next(s) & ~PAGE_MASK); | |
220 | } | |
221 | ||
6e9ed0cc | 222 | static void *slob_new_pages(gfp_t gfp, int order, int node) |
6193a2ff PM |
223 | { |
224 | void *page; | |
225 | ||
226 | #ifdef CONFIG_NUMA | |
227 | if (node != -1) | |
6484eb3e | 228 | page = alloc_pages_exact_node(node, gfp, order); |
6193a2ff PM |
229 | else |
230 | #endif | |
231 | page = alloc_pages(gfp, order); | |
232 | ||
233 | if (!page) | |
234 | return NULL; | |
235 | ||
236 | return page_address(page); | |
237 | } | |
238 | ||
6e9ed0cc AW |
239 | static void slob_free_pages(void *b, int order) |
240 | { | |
1f0532eb NP |
241 | if (current->reclaim_state) |
242 | current->reclaim_state->reclaimed_slab += 1 << order; | |
6e9ed0cc AW |
243 | free_pages((unsigned long)b, order); |
244 | } | |
245 | ||
95b35127 NP |
246 | /* |
247 | * Allocate a slob block within a given slob_page sp. | |
248 | */ | |
b8c24c4a | 249 | static void *slob_page_alloc(struct page *sp, size_t size, int align) |
10cef602 | 250 | { |
6e9ed0cc | 251 | slob_t *prev, *cur, *aligned = NULL; |
10cef602 | 252 | int delta = 0, units = SLOB_UNITS(size); |
10cef602 | 253 | |
b8c24c4a | 254 | for (prev = NULL, cur = sp->freelist; ; prev = cur, cur = slob_next(cur)) { |
95b35127 NP |
255 | slobidx_t avail = slob_units(cur); |
256 | ||
10cef602 MM |
257 | if (align) { |
258 | aligned = (slob_t *)ALIGN((unsigned long)cur, align); | |
259 | delta = aligned - cur; | |
260 | } | |
95b35127 NP |
261 | if (avail >= units + delta) { /* room enough? */ |
262 | slob_t *next; | |
263 | ||
10cef602 | 264 | if (delta) { /* need to fragment head to align? */ |
95b35127 NP |
265 | next = slob_next(cur); |
266 | set_slob(aligned, avail - delta, next); | |
267 | set_slob(cur, delta, aligned); | |
10cef602 MM |
268 | prev = cur; |
269 | cur = aligned; | |
95b35127 | 270 | avail = slob_units(cur); |
10cef602 MM |
271 | } |
272 | ||
95b35127 NP |
273 | next = slob_next(cur); |
274 | if (avail == units) { /* exact fit? unlink. */ | |
275 | if (prev) | |
276 | set_slob(prev, slob_units(prev), next); | |
277 | else | |
b8c24c4a | 278 | sp->freelist = next; |
95b35127 NP |
279 | } else { /* fragment */ |
280 | if (prev) | |
281 | set_slob(prev, slob_units(prev), cur + units); | |
282 | else | |
b8c24c4a | 283 | sp->freelist = cur + units; |
95b35127 | 284 | set_slob(cur + units, avail - units, next); |
10cef602 MM |
285 | } |
286 | ||
95b35127 NP |
287 | sp->units -= units; |
288 | if (!sp->units) | |
289 | clear_slob_page_free(sp); | |
10cef602 MM |
290 | return cur; |
291 | } | |
95b35127 NP |
292 | if (slob_last(cur)) |
293 | return NULL; | |
294 | } | |
295 | } | |
10cef602 | 296 | |
95b35127 NP |
297 | /* |
298 | * slob_alloc: entry point into the slob allocator. | |
299 | */ | |
6193a2ff | 300 | static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) |
95b35127 | 301 | { |
b8c24c4a | 302 | struct page *sp; |
d6269543 | 303 | struct list_head *prev; |
20cecbae | 304 | struct list_head *slob_list; |
95b35127 NP |
305 | slob_t *b = NULL; |
306 | unsigned long flags; | |
10cef602 | 307 | |
20cecbae MM |
308 | if (size < SLOB_BREAK1) |
309 | slob_list = &free_slob_small; | |
310 | else if (size < SLOB_BREAK2) | |
311 | slob_list = &free_slob_medium; | |
312 | else | |
313 | slob_list = &free_slob_large; | |
314 | ||
95b35127 NP |
315 | spin_lock_irqsave(&slob_lock, flags); |
316 | /* Iterate through each partially free page, try to find room */ | |
20cecbae | 317 | list_for_each_entry(sp, slob_list, list) { |
6193a2ff PM |
318 | #ifdef CONFIG_NUMA |
319 | /* | |
320 | * If there's a node specification, search for a partial | |
321 | * page with a matching node id in the freelist. | |
322 | */ | |
b8c24c4a | 323 | if (node != -1 && page_to_nid(sp) != node) |
6193a2ff PM |
324 | continue; |
325 | #endif | |
d6269543 MM |
326 | /* Enough room on this page? */ |
327 | if (sp->units < SLOB_UNITS(size)) | |
328 | continue; | |
6193a2ff | 329 | |
d6269543 MM |
330 | /* Attempt to alloc */ |
331 | prev = sp->list.prev; | |
332 | b = slob_page_alloc(sp, size, align); | |
333 | if (!b) | |
334 | continue; | |
335 | ||
336 | /* Improve fragment distribution and reduce our average | |
337 | * search time by starting our next search here. (see | |
338 | * Knuth vol 1, sec 2.5, pg 449) */ | |
20cecbae MM |
339 | if (prev != slob_list->prev && |
340 | slob_list->next != prev->next) | |
341 | list_move_tail(slob_list, prev->next); | |
d6269543 | 342 | break; |
10cef602 | 343 | } |
95b35127 NP |
344 | spin_unlock_irqrestore(&slob_lock, flags); |
345 | ||
346 | /* Not enough space: must allocate a new page */ | |
347 | if (!b) { | |
6e9ed0cc | 348 | b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node); |
95b35127 | 349 | if (!b) |
6e9ed0cc AW |
350 | return NULL; |
351 | sp = slob_page(b); | |
95b35127 NP |
352 | set_slob_page(sp); |
353 | ||
354 | spin_lock_irqsave(&slob_lock, flags); | |
355 | sp->units = SLOB_UNITS(PAGE_SIZE); | |
b8c24c4a | 356 | sp->freelist = b; |
95b35127 NP |
357 | INIT_LIST_HEAD(&sp->list); |
358 | set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE)); | |
20cecbae | 359 | set_slob_page_free(sp, slob_list); |
95b35127 NP |
360 | b = slob_page_alloc(sp, size, align); |
361 | BUG_ON(!b); | |
362 | spin_unlock_irqrestore(&slob_lock, flags); | |
363 | } | |
d07dbea4 CL |
364 | if (unlikely((gfp & __GFP_ZERO) && b)) |
365 | memset(b, 0, size); | |
95b35127 | 366 | return b; |
10cef602 MM |
367 | } |
368 | ||
95b35127 NP |
369 | /* |
370 | * slob_free: entry point into the slob allocator. | |
371 | */ | |
10cef602 MM |
372 | static void slob_free(void *block, int size) |
373 | { | |
b8c24c4a | 374 | struct page *sp; |
95b35127 NP |
375 | slob_t *prev, *next, *b = (slob_t *)block; |
376 | slobidx_t units; | |
10cef602 | 377 | unsigned long flags; |
d602daba | 378 | struct list_head *slob_list; |
10cef602 | 379 | |
2408c550 | 380 | if (unlikely(ZERO_OR_NULL_PTR(block))) |
10cef602 | 381 | return; |
95b35127 | 382 | BUG_ON(!size); |
10cef602 | 383 | |
6e9ed0cc | 384 | sp = slob_page(block); |
95b35127 | 385 | units = SLOB_UNITS(size); |
10cef602 | 386 | |
10cef602 | 387 | spin_lock_irqsave(&slob_lock, flags); |
10cef602 | 388 | |
95b35127 NP |
389 | if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) { |
390 | /* Go directly to page allocator. Do not pass slob allocator */ | |
391 | if (slob_page_free(sp)) | |
392 | clear_slob_page_free(sp); | |
6fb8f424 | 393 | spin_unlock_irqrestore(&slob_lock, flags); |
95b35127 NP |
394 | clear_slob_page(sp); |
395 | free_slob_page(sp); | |
1f0532eb | 396 | slob_free_pages(b, 0); |
6fb8f424 | 397 | return; |
95b35127 | 398 | } |
10cef602 | 399 | |
95b35127 NP |
400 | if (!slob_page_free(sp)) { |
401 | /* This slob page is about to become partially free. Easy! */ | |
402 | sp->units = units; | |
b8c24c4a | 403 | sp->freelist = b; |
95b35127 NP |
404 | set_slob(b, units, |
405 | (void *)((unsigned long)(b + | |
406 | SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK)); | |
d602daba BL |
407 | if (size < SLOB_BREAK1) |
408 | slob_list = &free_slob_small; | |
409 | else if (size < SLOB_BREAK2) | |
410 | slob_list = &free_slob_medium; | |
411 | else | |
412 | slob_list = &free_slob_large; | |
413 | set_slob_page_free(sp, slob_list); | |
95b35127 NP |
414 | goto out; |
415 | } | |
416 | ||
417 | /* | |
418 | * Otherwise the page is already partially free, so find reinsertion | |
419 | * point. | |
420 | */ | |
421 | sp->units += units; | |
10cef602 | 422 | |
b8c24c4a CL |
423 | if (b < (slob_t *)sp->freelist) { |
424 | if (b + units == sp->freelist) { | |
425 | units += slob_units(sp->freelist); | |
426 | sp->freelist = slob_next(sp->freelist); | |
679299b3 | 427 | } |
b8c24c4a CL |
428 | set_slob(b, units, sp->freelist); |
429 | sp->freelist = b; | |
95b35127 | 430 | } else { |
b8c24c4a | 431 | prev = sp->freelist; |
95b35127 NP |
432 | next = slob_next(prev); |
433 | while (b > next) { | |
434 | prev = next; | |
435 | next = slob_next(prev); | |
436 | } | |
10cef602 | 437 | |
95b35127 NP |
438 | if (!slob_last(prev) && b + units == next) { |
439 | units += slob_units(next); | |
440 | set_slob(b, units, slob_next(next)); | |
441 | } else | |
442 | set_slob(b, units, next); | |
443 | ||
444 | if (prev + slob_units(prev) == b) { | |
445 | units = slob_units(b) + slob_units(prev); | |
446 | set_slob(prev, units, slob_next(b)); | |
447 | } else | |
448 | set_slob(prev, slob_units(prev), b); | |
449 | } | |
450 | out: | |
10cef602 MM |
451 | spin_unlock_irqrestore(&slob_lock, flags); |
452 | } | |
453 | ||
95b35127 NP |
454 | /* |
455 | * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend. | |
456 | */ | |
457 | ||
6193a2ff | 458 | void *__kmalloc_node(size_t size, gfp_t gfp, int node) |
10cef602 | 459 | { |
6cb8f913 | 460 | unsigned int *m; |
55394849 | 461 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); |
3eae2cb2 | 462 | void *ret; |
55394849 | 463 | |
bd50cfa8 SR |
464 | gfp &= gfp_allowed_mask; |
465 | ||
19cefdff | 466 | lockdep_trace_alloc(gfp); |
cf40bd16 | 467 | |
55394849 | 468 | if (size < PAGE_SIZE - align) { |
6cb8f913 CL |
469 | if (!size) |
470 | return ZERO_SIZE_PTR; | |
471 | ||
6193a2ff | 472 | m = slob_alloc(size + align, gfp, align, node); |
3eae2cb2 | 473 | |
239f49c0 MK |
474 | if (!m) |
475 | return NULL; | |
476 | *m = size; | |
3eae2cb2 EGM |
477 | ret = (void *)m + align; |
478 | ||
ca2b84cb EGM |
479 | trace_kmalloc_node(_RET_IP_, ret, |
480 | size, size + align, gfp, node); | |
d87a133f | 481 | } else { |
3eae2cb2 | 482 | unsigned int order = get_order(size); |
d87a133f | 483 | |
8df275af DR |
484 | if (likely(order)) |
485 | gfp |= __GFP_COMP; | |
486 | ret = slob_new_pages(gfp, order, node); | |
d87a133f NP |
487 | if (ret) { |
488 | struct page *page; | |
489 | page = virt_to_page(ret); | |
490 | page->private = size; | |
491 | } | |
3eae2cb2 | 492 | |
ca2b84cb EGM |
493 | trace_kmalloc_node(_RET_IP_, ret, |
494 | size, PAGE_SIZE << order, gfp, node); | |
10cef602 | 495 | } |
3eae2cb2 | 496 | |
4374e616 | 497 | kmemleak_alloc(ret, size, 1, gfp); |
3eae2cb2 | 498 | return ret; |
10cef602 | 499 | } |
6193a2ff | 500 | EXPORT_SYMBOL(__kmalloc_node); |
10cef602 MM |
501 | |
502 | void kfree(const void *block) | |
503 | { | |
b8c24c4a | 504 | struct page *sp; |
10cef602 | 505 | |
2121db74 PE |
506 | trace_kfree(_RET_IP_, block); |
507 | ||
2408c550 | 508 | if (unlikely(ZERO_OR_NULL_PTR(block))) |
10cef602 | 509 | return; |
4374e616 | 510 | kmemleak_free(block); |
10cef602 | 511 | |
6e9ed0cc AW |
512 | sp = slob_page(block); |
513 | if (is_slob_page(sp)) { | |
55394849 NP |
514 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); |
515 | unsigned int *m = (unsigned int *)(block - align); | |
516 | slob_free(m, *m + align); | |
d87a133f | 517 | } else |
b8c24c4a | 518 | put_page(sp); |
10cef602 | 519 | } |
10cef602 MM |
520 | EXPORT_SYMBOL(kfree); |
521 | ||
d87a133f | 522 | /* can't use ksize for kmem_cache_alloc memory, only kmalloc */ |
fd76bab2 | 523 | size_t ksize(const void *block) |
10cef602 | 524 | { |
b8c24c4a | 525 | struct page *sp; |
10cef602 | 526 | |
ef8b4520 CL |
527 | BUG_ON(!block); |
528 | if (unlikely(block == ZERO_SIZE_PTR)) | |
10cef602 MM |
529 | return 0; |
530 | ||
6e9ed0cc AW |
531 | sp = slob_page(block); |
532 | if (is_slob_page(sp)) { | |
70096a56 MM |
533 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); |
534 | unsigned int *m = (unsigned int *)(block - align); | |
535 | return SLOB_UNITS(*m) * SLOB_UNIT; | |
536 | } else | |
b8c24c4a | 537 | return sp->private; |
10cef602 | 538 | } |
b1aabecd | 539 | EXPORT_SYMBOL(ksize); |
10cef602 MM |
540 | |
541 | struct kmem_cache { | |
542 | unsigned int size, align; | |
afc0cedb | 543 | unsigned long flags; |
10cef602 | 544 | const char *name; |
51cc5068 | 545 | void (*ctor)(void *); |
10cef602 MM |
546 | }; |
547 | ||
548 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |
51cc5068 | 549 | size_t align, unsigned long flags, void (*ctor)(void *)) |
10cef602 MM |
550 | { |
551 | struct kmem_cache *c; | |
552 | ||
0701a9e6 | 553 | c = slob_alloc(sizeof(struct kmem_cache), |
5e18e2b8 | 554 | GFP_KERNEL, ARCH_KMALLOC_MINALIGN, -1); |
10cef602 MM |
555 | |
556 | if (c) { | |
557 | c->name = name; | |
558 | c->size = size; | |
afc0cedb | 559 | if (flags & SLAB_DESTROY_BY_RCU) { |
afc0cedb NP |
560 | /* leave room for rcu footer at the end of object */ |
561 | c->size += sizeof(struct slob_rcu); | |
562 | } | |
563 | c->flags = flags; | |
10cef602 | 564 | c->ctor = ctor; |
10cef602 | 565 | /* ignore alignment unless it's forced */ |
5af60839 | 566 | c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0; |
55394849 NP |
567 | if (c->align < ARCH_SLAB_MINALIGN) |
568 | c->align = ARCH_SLAB_MINALIGN; | |
10cef602 MM |
569 | if (c->align < align) |
570 | c->align = align; | |
bc0055ae AM |
571 | } else if (flags & SLAB_PANIC) |
572 | panic("Cannot create slab cache %s\n", name); | |
10cef602 | 573 | |
4374e616 | 574 | kmemleak_alloc(c, sizeof(struct kmem_cache), 1, GFP_KERNEL); |
10cef602 MM |
575 | return c; |
576 | } | |
577 | EXPORT_SYMBOL(kmem_cache_create); | |
578 | ||
133d205a | 579 | void kmem_cache_destroy(struct kmem_cache *c) |
10cef602 | 580 | { |
4374e616 | 581 | kmemleak_free(c); |
7ed9f7e5 PM |
582 | if (c->flags & SLAB_DESTROY_BY_RCU) |
583 | rcu_barrier(); | |
10cef602 | 584 | slob_free(c, sizeof(struct kmem_cache)); |
10cef602 MM |
585 | } |
586 | EXPORT_SYMBOL(kmem_cache_destroy); | |
587 | ||
6193a2ff | 588 | void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node) |
10cef602 MM |
589 | { |
590 | void *b; | |
591 | ||
bd50cfa8 SR |
592 | flags &= gfp_allowed_mask; |
593 | ||
594 | lockdep_trace_alloc(flags); | |
595 | ||
3eae2cb2 | 596 | if (c->size < PAGE_SIZE) { |
6193a2ff | 597 | b = slob_alloc(c->size, flags, c->align, node); |
ca2b84cb EGM |
598 | trace_kmem_cache_alloc_node(_RET_IP_, b, c->size, |
599 | SLOB_UNITS(c->size) * SLOB_UNIT, | |
600 | flags, node); | |
3eae2cb2 | 601 | } else { |
6e9ed0cc | 602 | b = slob_new_pages(flags, get_order(c->size), node); |
ca2b84cb EGM |
603 | trace_kmem_cache_alloc_node(_RET_IP_, b, c->size, |
604 | PAGE_SIZE << get_order(c->size), | |
605 | flags, node); | |
3eae2cb2 | 606 | } |
10cef602 MM |
607 | |
608 | if (c->ctor) | |
51cc5068 | 609 | c->ctor(b); |
10cef602 | 610 | |
4374e616 | 611 | kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags); |
10cef602 MM |
612 | return b; |
613 | } | |
6193a2ff | 614 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
10cef602 | 615 | |
afc0cedb | 616 | static void __kmem_cache_free(void *b, int size) |
10cef602 | 617 | { |
afc0cedb NP |
618 | if (size < PAGE_SIZE) |
619 | slob_free(b, size); | |
10cef602 | 620 | else |
6e9ed0cc | 621 | slob_free_pages(b, get_order(size)); |
afc0cedb NP |
622 | } |
623 | ||
624 | static void kmem_rcu_free(struct rcu_head *head) | |
625 | { | |
626 | struct slob_rcu *slob_rcu = (struct slob_rcu *)head; | |
627 | void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu)); | |
628 | ||
629 | __kmem_cache_free(b, slob_rcu->size); | |
630 | } | |
631 | ||
632 | void kmem_cache_free(struct kmem_cache *c, void *b) | |
633 | { | |
4374e616 | 634 | kmemleak_free_recursive(b, c->flags); |
afc0cedb NP |
635 | if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) { |
636 | struct slob_rcu *slob_rcu; | |
637 | slob_rcu = b + (c->size - sizeof(struct slob_rcu)); | |
afc0cedb NP |
638 | slob_rcu->size = c->size; |
639 | call_rcu(&slob_rcu->head, kmem_rcu_free); | |
640 | } else { | |
afc0cedb NP |
641 | __kmem_cache_free(b, c->size); |
642 | } | |
3eae2cb2 | 643 | |
ca2b84cb | 644 | trace_kmem_cache_free(_RET_IP_, b); |
10cef602 MM |
645 | } |
646 | EXPORT_SYMBOL(kmem_cache_free); | |
647 | ||
648 | unsigned int kmem_cache_size(struct kmem_cache *c) | |
649 | { | |
650 | return c->size; | |
651 | } | |
652 | EXPORT_SYMBOL(kmem_cache_size); | |
653 | ||
2e892f43 CL |
654 | int kmem_cache_shrink(struct kmem_cache *d) |
655 | { | |
656 | return 0; | |
657 | } | |
658 | EXPORT_SYMBOL(kmem_cache_shrink); | |
659 | ||
84a01c2f PM |
660 | static unsigned int slob_ready __read_mostly; |
661 | ||
662 | int slab_is_available(void) | |
663 | { | |
664 | return slob_ready; | |
665 | } | |
666 | ||
bcb4ddb4 DG |
667 | void __init kmem_cache_init(void) |
668 | { | |
84a01c2f | 669 | slob_ready = 1; |
10cef602 | 670 | } |
bbff2e43 WF |
671 | |
672 | void __init kmem_cache_init_late(void) | |
673 | { | |
674 | /* Nothing to do */ | |
675 | } |