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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 | 94 | /* |
20cecbae | 95 | * All partially free slob pages go on these lists. |
95b35127 | 96 | */ |
20cecbae MM |
97 | #define SLOB_BREAK1 256 |
98 | #define SLOB_BREAK2 1024 | |
99 | static LIST_HEAD(free_slob_small); | |
100 | static LIST_HEAD(free_slob_medium); | |
101 | static LIST_HEAD(free_slob_large); | |
95b35127 | 102 | |
95b35127 NP |
103 | /* |
104 | * slob_page_free: true for pages on free_slob_pages list. | |
105 | */ | |
b8c24c4a | 106 | static inline int slob_page_free(struct page *sp) |
95b35127 | 107 | { |
b8c24c4a | 108 | return PageSlobFree(sp); |
95b35127 NP |
109 | } |
110 | ||
b8c24c4a | 111 | static void set_slob_page_free(struct page *sp, struct list_head *list) |
95b35127 | 112 | { |
20cecbae | 113 | list_add(&sp->list, list); |
b8c24c4a | 114 | __SetPageSlobFree(sp); |
95b35127 NP |
115 | } |
116 | ||
b8c24c4a | 117 | static inline void clear_slob_page_free(struct page *sp) |
95b35127 NP |
118 | { |
119 | list_del(&sp->list); | |
b8c24c4a | 120 | __ClearPageSlobFree(sp); |
95b35127 NP |
121 | } |
122 | ||
10cef602 MM |
123 | #define SLOB_UNIT sizeof(slob_t) |
124 | #define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT) | |
125 | #define SLOB_ALIGN L1_CACHE_BYTES | |
126 | ||
afc0cedb NP |
127 | /* |
128 | * struct slob_rcu is inserted at the tail of allocated slob blocks, which | |
129 | * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free | |
130 | * the block using call_rcu. | |
131 | */ | |
132 | struct slob_rcu { | |
133 | struct rcu_head head; | |
134 | int size; | |
135 | }; | |
136 | ||
95b35127 NP |
137 | /* |
138 | * slob_lock protects all slob allocator structures. | |
139 | */ | |
10cef602 | 140 | static DEFINE_SPINLOCK(slob_lock); |
10cef602 | 141 | |
95b35127 NP |
142 | /* |
143 | * Encode the given size and next info into a free slob block s. | |
144 | */ | |
145 | static void set_slob(slob_t *s, slobidx_t size, slob_t *next) | |
146 | { | |
147 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
148 | slobidx_t offset = next - base; | |
bcb4ddb4 | 149 | |
95b35127 NP |
150 | if (size > 1) { |
151 | s[0].units = size; | |
152 | s[1].units = offset; | |
153 | } else | |
154 | s[0].units = -offset; | |
155 | } | |
10cef602 | 156 | |
95b35127 NP |
157 | /* |
158 | * Return the size of a slob block. | |
159 | */ | |
160 | static slobidx_t slob_units(slob_t *s) | |
161 | { | |
162 | if (s->units > 0) | |
163 | return s->units; | |
164 | return 1; | |
165 | } | |
166 | ||
167 | /* | |
168 | * Return the next free slob block pointer after this one. | |
169 | */ | |
170 | static slob_t *slob_next(slob_t *s) | |
171 | { | |
172 | slob_t *base = (slob_t *)((unsigned long)s & PAGE_MASK); | |
173 | slobidx_t next; | |
174 | ||
175 | if (s[0].units < 0) | |
176 | next = -s[0].units; | |
177 | else | |
178 | next = s[1].units; | |
179 | return base+next; | |
180 | } | |
181 | ||
182 | /* | |
183 | * Returns true if s is the last free block in its page. | |
184 | */ | |
185 | static int slob_last(slob_t *s) | |
186 | { | |
187 | return !((unsigned long)slob_next(s) & ~PAGE_MASK); | |
188 | } | |
189 | ||
6e9ed0cc | 190 | static void *slob_new_pages(gfp_t gfp, int order, int node) |
6193a2ff PM |
191 | { |
192 | void *page; | |
193 | ||
194 | #ifdef CONFIG_NUMA | |
195 | if (node != -1) | |
6484eb3e | 196 | page = alloc_pages_exact_node(node, gfp, order); |
6193a2ff PM |
197 | else |
198 | #endif | |
199 | page = alloc_pages(gfp, order); | |
200 | ||
201 | if (!page) | |
202 | return NULL; | |
203 | ||
204 | return page_address(page); | |
205 | } | |
206 | ||
6e9ed0cc AW |
207 | static void slob_free_pages(void *b, int order) |
208 | { | |
1f0532eb NP |
209 | if (current->reclaim_state) |
210 | current->reclaim_state->reclaimed_slab += 1 << order; | |
6e9ed0cc AW |
211 | free_pages((unsigned long)b, order); |
212 | } | |
213 | ||
95b35127 NP |
214 | /* |
215 | * Allocate a slob block within a given slob_page sp. | |
216 | */ | |
b8c24c4a | 217 | static void *slob_page_alloc(struct page *sp, size_t size, int align) |
10cef602 | 218 | { |
6e9ed0cc | 219 | slob_t *prev, *cur, *aligned = NULL; |
10cef602 | 220 | int delta = 0, units = SLOB_UNITS(size); |
10cef602 | 221 | |
b8c24c4a | 222 | for (prev = NULL, cur = sp->freelist; ; prev = cur, cur = slob_next(cur)) { |
95b35127 NP |
223 | slobidx_t avail = slob_units(cur); |
224 | ||
10cef602 MM |
225 | if (align) { |
226 | aligned = (slob_t *)ALIGN((unsigned long)cur, align); | |
227 | delta = aligned - cur; | |
228 | } | |
95b35127 NP |
229 | if (avail >= units + delta) { /* room enough? */ |
230 | slob_t *next; | |
231 | ||
10cef602 | 232 | if (delta) { /* need to fragment head to align? */ |
95b35127 NP |
233 | next = slob_next(cur); |
234 | set_slob(aligned, avail - delta, next); | |
235 | set_slob(cur, delta, aligned); | |
10cef602 MM |
236 | prev = cur; |
237 | cur = aligned; | |
95b35127 | 238 | avail = slob_units(cur); |
10cef602 MM |
239 | } |
240 | ||
95b35127 NP |
241 | next = slob_next(cur); |
242 | if (avail == units) { /* exact fit? unlink. */ | |
243 | if (prev) | |
244 | set_slob(prev, slob_units(prev), next); | |
245 | else | |
b8c24c4a | 246 | sp->freelist = next; |
95b35127 NP |
247 | } else { /* fragment */ |
248 | if (prev) | |
249 | set_slob(prev, slob_units(prev), cur + units); | |
250 | else | |
b8c24c4a | 251 | sp->freelist = cur + units; |
95b35127 | 252 | set_slob(cur + units, avail - units, next); |
10cef602 MM |
253 | } |
254 | ||
95b35127 NP |
255 | sp->units -= units; |
256 | if (!sp->units) | |
257 | clear_slob_page_free(sp); | |
10cef602 MM |
258 | return cur; |
259 | } | |
95b35127 NP |
260 | if (slob_last(cur)) |
261 | return NULL; | |
262 | } | |
263 | } | |
10cef602 | 264 | |
95b35127 NP |
265 | /* |
266 | * slob_alloc: entry point into the slob allocator. | |
267 | */ | |
6193a2ff | 268 | static void *slob_alloc(size_t size, gfp_t gfp, int align, int node) |
95b35127 | 269 | { |
b8c24c4a | 270 | struct page *sp; |
d6269543 | 271 | struct list_head *prev; |
20cecbae | 272 | struct list_head *slob_list; |
95b35127 NP |
273 | slob_t *b = NULL; |
274 | unsigned long flags; | |
10cef602 | 275 | |
20cecbae MM |
276 | if (size < SLOB_BREAK1) |
277 | slob_list = &free_slob_small; | |
278 | else if (size < SLOB_BREAK2) | |
279 | slob_list = &free_slob_medium; | |
280 | else | |
281 | slob_list = &free_slob_large; | |
282 | ||
95b35127 NP |
283 | spin_lock_irqsave(&slob_lock, flags); |
284 | /* Iterate through each partially free page, try to find room */ | |
20cecbae | 285 | list_for_each_entry(sp, slob_list, list) { |
6193a2ff PM |
286 | #ifdef CONFIG_NUMA |
287 | /* | |
288 | * If there's a node specification, search for a partial | |
289 | * page with a matching node id in the freelist. | |
290 | */ | |
b8c24c4a | 291 | if (node != -1 && page_to_nid(sp) != node) |
6193a2ff PM |
292 | continue; |
293 | #endif | |
d6269543 MM |
294 | /* Enough room on this page? */ |
295 | if (sp->units < SLOB_UNITS(size)) | |
296 | continue; | |
6193a2ff | 297 | |
d6269543 MM |
298 | /* Attempt to alloc */ |
299 | prev = sp->list.prev; | |
300 | b = slob_page_alloc(sp, size, align); | |
301 | if (!b) | |
302 | continue; | |
303 | ||
304 | /* Improve fragment distribution and reduce our average | |
305 | * search time by starting our next search here. (see | |
306 | * Knuth vol 1, sec 2.5, pg 449) */ | |
20cecbae MM |
307 | if (prev != slob_list->prev && |
308 | slob_list->next != prev->next) | |
309 | list_move_tail(slob_list, prev->next); | |
d6269543 | 310 | break; |
10cef602 | 311 | } |
95b35127 NP |
312 | spin_unlock_irqrestore(&slob_lock, flags); |
313 | ||
314 | /* Not enough space: must allocate a new page */ | |
315 | if (!b) { | |
6e9ed0cc | 316 | b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node); |
95b35127 | 317 | if (!b) |
6e9ed0cc | 318 | return NULL; |
b5568280 CL |
319 | sp = virt_to_page(b); |
320 | __SetPageSlab(sp); | |
95b35127 NP |
321 | |
322 | spin_lock_irqsave(&slob_lock, flags); | |
323 | sp->units = SLOB_UNITS(PAGE_SIZE); | |
b8c24c4a | 324 | sp->freelist = b; |
95b35127 NP |
325 | INIT_LIST_HEAD(&sp->list); |
326 | set_slob(b, SLOB_UNITS(PAGE_SIZE), b + SLOB_UNITS(PAGE_SIZE)); | |
20cecbae | 327 | set_slob_page_free(sp, slob_list); |
95b35127 NP |
328 | b = slob_page_alloc(sp, size, align); |
329 | BUG_ON(!b); | |
330 | spin_unlock_irqrestore(&slob_lock, flags); | |
331 | } | |
d07dbea4 CL |
332 | if (unlikely((gfp & __GFP_ZERO) && b)) |
333 | memset(b, 0, size); | |
95b35127 | 334 | return b; |
10cef602 MM |
335 | } |
336 | ||
95b35127 NP |
337 | /* |
338 | * slob_free: entry point into the slob allocator. | |
339 | */ | |
10cef602 MM |
340 | static void slob_free(void *block, int size) |
341 | { | |
b8c24c4a | 342 | struct page *sp; |
95b35127 NP |
343 | slob_t *prev, *next, *b = (slob_t *)block; |
344 | slobidx_t units; | |
10cef602 | 345 | unsigned long flags; |
d602daba | 346 | struct list_head *slob_list; |
10cef602 | 347 | |
2408c550 | 348 | if (unlikely(ZERO_OR_NULL_PTR(block))) |
10cef602 | 349 | return; |
95b35127 | 350 | BUG_ON(!size); |
10cef602 | 351 | |
b5568280 | 352 | sp = virt_to_page(block); |
95b35127 | 353 | units = SLOB_UNITS(size); |
10cef602 | 354 | |
10cef602 | 355 | spin_lock_irqsave(&slob_lock, flags); |
10cef602 | 356 | |
95b35127 NP |
357 | if (sp->units + units == SLOB_UNITS(PAGE_SIZE)) { |
358 | /* Go directly to page allocator. Do not pass slob allocator */ | |
359 | if (slob_page_free(sp)) | |
360 | clear_slob_page_free(sp); | |
6fb8f424 | 361 | spin_unlock_irqrestore(&slob_lock, flags); |
b5568280 CL |
362 | __ClearPageSlab(sp); |
363 | reset_page_mapcount(sp); | |
1f0532eb | 364 | slob_free_pages(b, 0); |
6fb8f424 | 365 | return; |
95b35127 | 366 | } |
10cef602 | 367 | |
95b35127 NP |
368 | if (!slob_page_free(sp)) { |
369 | /* This slob page is about to become partially free. Easy! */ | |
370 | sp->units = units; | |
b8c24c4a | 371 | sp->freelist = b; |
95b35127 NP |
372 | set_slob(b, units, |
373 | (void *)((unsigned long)(b + | |
374 | SLOB_UNITS(PAGE_SIZE)) & PAGE_MASK)); | |
d602daba BL |
375 | if (size < SLOB_BREAK1) |
376 | slob_list = &free_slob_small; | |
377 | else if (size < SLOB_BREAK2) | |
378 | slob_list = &free_slob_medium; | |
379 | else | |
380 | slob_list = &free_slob_large; | |
381 | set_slob_page_free(sp, slob_list); | |
95b35127 NP |
382 | goto out; |
383 | } | |
384 | ||
385 | /* | |
386 | * Otherwise the page is already partially free, so find reinsertion | |
387 | * point. | |
388 | */ | |
389 | sp->units += units; | |
10cef602 | 390 | |
b8c24c4a CL |
391 | if (b < (slob_t *)sp->freelist) { |
392 | if (b + units == sp->freelist) { | |
393 | units += slob_units(sp->freelist); | |
394 | sp->freelist = slob_next(sp->freelist); | |
679299b3 | 395 | } |
b8c24c4a CL |
396 | set_slob(b, units, sp->freelist); |
397 | sp->freelist = b; | |
95b35127 | 398 | } else { |
b8c24c4a | 399 | prev = sp->freelist; |
95b35127 NP |
400 | next = slob_next(prev); |
401 | while (b > next) { | |
402 | prev = next; | |
403 | next = slob_next(prev); | |
404 | } | |
10cef602 | 405 | |
95b35127 NP |
406 | if (!slob_last(prev) && b + units == next) { |
407 | units += slob_units(next); | |
408 | set_slob(b, units, slob_next(next)); | |
409 | } else | |
410 | set_slob(b, units, next); | |
411 | ||
412 | if (prev + slob_units(prev) == b) { | |
413 | units = slob_units(b) + slob_units(prev); | |
414 | set_slob(prev, units, slob_next(b)); | |
415 | } else | |
416 | set_slob(prev, slob_units(prev), b); | |
417 | } | |
418 | out: | |
10cef602 MM |
419 | spin_unlock_irqrestore(&slob_lock, flags); |
420 | } | |
421 | ||
95b35127 NP |
422 | /* |
423 | * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend. | |
424 | */ | |
425 | ||
6193a2ff | 426 | void *__kmalloc_node(size_t size, gfp_t gfp, int node) |
10cef602 | 427 | { |
6cb8f913 | 428 | unsigned int *m; |
55394849 | 429 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); |
3eae2cb2 | 430 | void *ret; |
55394849 | 431 | |
bd50cfa8 SR |
432 | gfp &= gfp_allowed_mask; |
433 | ||
19cefdff | 434 | lockdep_trace_alloc(gfp); |
cf40bd16 | 435 | |
55394849 | 436 | if (size < PAGE_SIZE - align) { |
6cb8f913 CL |
437 | if (!size) |
438 | return ZERO_SIZE_PTR; | |
439 | ||
6193a2ff | 440 | m = slob_alloc(size + align, gfp, align, node); |
3eae2cb2 | 441 | |
239f49c0 MK |
442 | if (!m) |
443 | return NULL; | |
444 | *m = size; | |
3eae2cb2 EGM |
445 | ret = (void *)m + align; |
446 | ||
ca2b84cb EGM |
447 | trace_kmalloc_node(_RET_IP_, ret, |
448 | size, size + align, gfp, node); | |
d87a133f | 449 | } else { |
3eae2cb2 | 450 | unsigned int order = get_order(size); |
d87a133f | 451 | |
8df275af DR |
452 | if (likely(order)) |
453 | gfp |= __GFP_COMP; | |
454 | ret = slob_new_pages(gfp, order, node); | |
d87a133f NP |
455 | if (ret) { |
456 | struct page *page; | |
457 | page = virt_to_page(ret); | |
458 | page->private = size; | |
459 | } | |
3eae2cb2 | 460 | |
ca2b84cb EGM |
461 | trace_kmalloc_node(_RET_IP_, ret, |
462 | size, PAGE_SIZE << order, gfp, node); | |
10cef602 | 463 | } |
3eae2cb2 | 464 | |
4374e616 | 465 | kmemleak_alloc(ret, size, 1, gfp); |
3eae2cb2 | 466 | return ret; |
10cef602 | 467 | } |
6193a2ff | 468 | EXPORT_SYMBOL(__kmalloc_node); |
10cef602 MM |
469 | |
470 | void kfree(const void *block) | |
471 | { | |
b8c24c4a | 472 | struct page *sp; |
10cef602 | 473 | |
2121db74 PE |
474 | trace_kfree(_RET_IP_, block); |
475 | ||
2408c550 | 476 | if (unlikely(ZERO_OR_NULL_PTR(block))) |
10cef602 | 477 | return; |
4374e616 | 478 | kmemleak_free(block); |
10cef602 | 479 | |
b5568280 CL |
480 | sp = virt_to_page(block); |
481 | if (PageSlab(sp)) { | |
55394849 NP |
482 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); |
483 | unsigned int *m = (unsigned int *)(block - align); | |
484 | slob_free(m, *m + align); | |
d87a133f | 485 | } else |
b8c24c4a | 486 | put_page(sp); |
10cef602 | 487 | } |
10cef602 MM |
488 | EXPORT_SYMBOL(kfree); |
489 | ||
d87a133f | 490 | /* can't use ksize for kmem_cache_alloc memory, only kmalloc */ |
fd76bab2 | 491 | size_t ksize(const void *block) |
10cef602 | 492 | { |
b8c24c4a | 493 | struct page *sp; |
10cef602 | 494 | |
ef8b4520 CL |
495 | BUG_ON(!block); |
496 | if (unlikely(block == ZERO_SIZE_PTR)) | |
10cef602 MM |
497 | return 0; |
498 | ||
b5568280 CL |
499 | sp = virt_to_page(block); |
500 | if (PageSlab(sp)) { | |
70096a56 MM |
501 | int align = max(ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); |
502 | unsigned int *m = (unsigned int *)(block - align); | |
503 | return SLOB_UNITS(*m) * SLOB_UNIT; | |
504 | } else | |
b8c24c4a | 505 | return sp->private; |
10cef602 | 506 | } |
b1aabecd | 507 | EXPORT_SYMBOL(ksize); |
10cef602 MM |
508 | |
509 | struct kmem_cache { | |
510 | unsigned int size, align; | |
afc0cedb | 511 | unsigned long flags; |
10cef602 | 512 | const char *name; |
51cc5068 | 513 | void (*ctor)(void *); |
10cef602 MM |
514 | }; |
515 | ||
516 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |
51cc5068 | 517 | size_t align, unsigned long flags, void (*ctor)(void *)) |
10cef602 MM |
518 | { |
519 | struct kmem_cache *c; | |
520 | ||
0701a9e6 | 521 | c = slob_alloc(sizeof(struct kmem_cache), |
5e18e2b8 | 522 | GFP_KERNEL, ARCH_KMALLOC_MINALIGN, -1); |
10cef602 MM |
523 | |
524 | if (c) { | |
525 | c->name = name; | |
526 | c->size = size; | |
afc0cedb | 527 | if (flags & SLAB_DESTROY_BY_RCU) { |
afc0cedb NP |
528 | /* leave room for rcu footer at the end of object */ |
529 | c->size += sizeof(struct slob_rcu); | |
530 | } | |
531 | c->flags = flags; | |
10cef602 | 532 | c->ctor = ctor; |
10cef602 | 533 | /* ignore alignment unless it's forced */ |
5af60839 | 534 | c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0; |
55394849 NP |
535 | if (c->align < ARCH_SLAB_MINALIGN) |
536 | c->align = ARCH_SLAB_MINALIGN; | |
10cef602 MM |
537 | if (c->align < align) |
538 | c->align = align; | |
bc0055ae AM |
539 | } else if (flags & SLAB_PANIC) |
540 | panic("Cannot create slab cache %s\n", name); | |
10cef602 | 541 | |
4374e616 | 542 | kmemleak_alloc(c, sizeof(struct kmem_cache), 1, GFP_KERNEL); |
10cef602 MM |
543 | return c; |
544 | } | |
545 | EXPORT_SYMBOL(kmem_cache_create); | |
546 | ||
133d205a | 547 | void kmem_cache_destroy(struct kmem_cache *c) |
10cef602 | 548 | { |
4374e616 | 549 | kmemleak_free(c); |
7ed9f7e5 PM |
550 | if (c->flags & SLAB_DESTROY_BY_RCU) |
551 | rcu_barrier(); | |
10cef602 | 552 | slob_free(c, sizeof(struct kmem_cache)); |
10cef602 MM |
553 | } |
554 | EXPORT_SYMBOL(kmem_cache_destroy); | |
555 | ||
6193a2ff | 556 | void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node) |
10cef602 MM |
557 | { |
558 | void *b; | |
559 | ||
bd50cfa8 SR |
560 | flags &= gfp_allowed_mask; |
561 | ||
562 | lockdep_trace_alloc(flags); | |
563 | ||
3eae2cb2 | 564 | if (c->size < PAGE_SIZE) { |
6193a2ff | 565 | b = slob_alloc(c->size, flags, c->align, node); |
ca2b84cb EGM |
566 | trace_kmem_cache_alloc_node(_RET_IP_, b, c->size, |
567 | SLOB_UNITS(c->size) * SLOB_UNIT, | |
568 | flags, node); | |
3eae2cb2 | 569 | } else { |
6e9ed0cc | 570 | b = slob_new_pages(flags, get_order(c->size), node); |
ca2b84cb EGM |
571 | trace_kmem_cache_alloc_node(_RET_IP_, b, c->size, |
572 | PAGE_SIZE << get_order(c->size), | |
573 | flags, node); | |
3eae2cb2 | 574 | } |
10cef602 MM |
575 | |
576 | if (c->ctor) | |
51cc5068 | 577 | c->ctor(b); |
10cef602 | 578 | |
4374e616 | 579 | kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags); |
10cef602 MM |
580 | return b; |
581 | } | |
6193a2ff | 582 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
10cef602 | 583 | |
afc0cedb | 584 | static void __kmem_cache_free(void *b, int size) |
10cef602 | 585 | { |
afc0cedb NP |
586 | if (size < PAGE_SIZE) |
587 | slob_free(b, size); | |
10cef602 | 588 | else |
6e9ed0cc | 589 | slob_free_pages(b, get_order(size)); |
afc0cedb NP |
590 | } |
591 | ||
592 | static void kmem_rcu_free(struct rcu_head *head) | |
593 | { | |
594 | struct slob_rcu *slob_rcu = (struct slob_rcu *)head; | |
595 | void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu)); | |
596 | ||
597 | __kmem_cache_free(b, slob_rcu->size); | |
598 | } | |
599 | ||
600 | void kmem_cache_free(struct kmem_cache *c, void *b) | |
601 | { | |
4374e616 | 602 | kmemleak_free_recursive(b, c->flags); |
afc0cedb NP |
603 | if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) { |
604 | struct slob_rcu *slob_rcu; | |
605 | slob_rcu = b + (c->size - sizeof(struct slob_rcu)); | |
afc0cedb NP |
606 | slob_rcu->size = c->size; |
607 | call_rcu(&slob_rcu->head, kmem_rcu_free); | |
608 | } else { | |
afc0cedb NP |
609 | __kmem_cache_free(b, c->size); |
610 | } | |
3eae2cb2 | 611 | |
ca2b84cb | 612 | trace_kmem_cache_free(_RET_IP_, b); |
10cef602 MM |
613 | } |
614 | EXPORT_SYMBOL(kmem_cache_free); | |
615 | ||
616 | unsigned int kmem_cache_size(struct kmem_cache *c) | |
617 | { | |
618 | return c->size; | |
619 | } | |
620 | EXPORT_SYMBOL(kmem_cache_size); | |
621 | ||
2e892f43 CL |
622 | int kmem_cache_shrink(struct kmem_cache *d) |
623 | { | |
624 | return 0; | |
625 | } | |
626 | EXPORT_SYMBOL(kmem_cache_shrink); | |
627 | ||
84a01c2f PM |
628 | static unsigned int slob_ready __read_mostly; |
629 | ||
630 | int slab_is_available(void) | |
631 | { | |
632 | return slob_ready; | |
633 | } | |
634 | ||
bcb4ddb4 DG |
635 | void __init kmem_cache_init(void) |
636 | { | |
84a01c2f | 637 | slob_ready = 1; |
10cef602 | 638 | } |
bbff2e43 WF |
639 | |
640 | void __init kmem_cache_init_late(void) | |
641 | { | |
642 | /* Nothing to do */ | |
643 | } |