blob: 1c0294858527367442c4c3f142e2972451352c5d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/mm/mempool.c
3 *
4 * memory buffer pool support. Such pools are mostly used
5 * for guaranteed, deadlock-free memory allocations during
6 * extreme VM load.
7 *
8 * started by Ingo Molnar, Copyright (C) 2001
David Rientjesbdfedb72015-04-15 16:14:17 -07009 * debugging by David Rientjes, Copyright (C) 2015
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
11
12#include <linux/mm.h>
13#include <linux/slab.h>
David Rientjesbdfedb72015-04-15 16:14:17 -070014#include <linux/highmem.h>
Andrey Ryabinin92393612015-04-15 16:15:05 -070015#include <linux/kasan.h>
Catalin Marinas17411962014-06-06 14:38:19 -070016#include <linux/kmemleak.h>
Paul Gortmakerb95f1b312011-10-16 02:01:52 -040017#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/mempool.h>
19#include <linux/blkdev.h>
20#include <linux/writeback.h>
David Rientjese244c9e2015-04-15 16:14:14 -070021#include "slab.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
David Rientjesbdfedb72015-04-15 16:14:17 -070023#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB_DEBUG_ON)
24static void poison_error(mempool_t *pool, void *element, size_t size,
25 size_t byte)
26{
27 const int nr = pool->curr_nr;
28 const int start = max_t(int, byte - (BITS_PER_LONG / 8), 0);
29 const int end = min_t(int, byte + (BITS_PER_LONG / 8), size);
30 int i;
31
32 pr_err("BUG: mempool element poison mismatch\n");
33 pr_err("Mempool %p size %zu\n", pool, size);
34 pr_err(" nr=%d @ %p: %s0x", nr, element, start > 0 ? "... " : "");
35 for (i = start; i < end; i++)
36 pr_cont("%x ", *(u8 *)(element + i));
37 pr_cont("%s\n", end < size ? "..." : "");
38 dump_stack();
39}
40
41static void __check_element(mempool_t *pool, void *element, size_t size)
42{
43 u8 *obj = element;
44 size_t i;
45
46 for (i = 0; i < size; i++) {
47 u8 exp = (i < size - 1) ? POISON_FREE : POISON_END;
48
49 if (obj[i] != exp) {
50 poison_error(pool, element, size, i);
51 return;
52 }
53 }
54 memset(obj, POISON_INUSE, size);
55}
56
57static void check_element(mempool_t *pool, void *element)
58{
59 /* Mempools backed by slab allocator */
60 if (pool->free == mempool_free_slab || pool->free == mempool_kfree)
61 __check_element(pool, element, ksize(element));
62
63 /* Mempools backed by page allocator */
64 if (pool->free == mempool_free_pages) {
65 int order = (int)(long)pool->pool_data;
66 void *addr = kmap_atomic((struct page *)element);
67
68 __check_element(pool, addr, 1UL << (PAGE_SHIFT + order));
69 kunmap_atomic(addr);
70 }
71}
72
73static void __poison_element(void *element, size_t size)
74{
75 u8 *obj = element;
76
77 memset(obj, POISON_FREE, size - 1);
78 obj[size - 1] = POISON_END;
79}
80
81static void poison_element(mempool_t *pool, void *element)
82{
83 /* Mempools backed by slab allocator */
84 if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
85 __poison_element(element, ksize(element));
86
87 /* Mempools backed by page allocator */
88 if (pool->alloc == mempool_alloc_pages) {
89 int order = (int)(long)pool->pool_data;
90 void *addr = kmap_atomic((struct page *)element);
91
92 __poison_element(addr, 1UL << (PAGE_SHIFT + order));
93 kunmap_atomic(addr);
94 }
95}
96#else /* CONFIG_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */
97static inline void check_element(mempool_t *pool, void *element)
98{
99}
100static inline void poison_element(mempool_t *pool, void *element)
101{
102}
103#endif /* CONFIG_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */
104
Andrey Ryabinin92393612015-04-15 16:15:05 -0700105static void kasan_poison_element(mempool_t *pool, void *element)
106{
Andrey Ryabinin9b75a862016-06-24 14:49:34 -0700107 if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
108 kasan_poison_kfree(element);
Andrey Ryabinin92393612015-04-15 16:15:05 -0700109 if (pool->alloc == mempool_alloc_pages)
110 kasan_free_pages(element, (unsigned long)pool->pool_data);
111}
112
Alexander Potapenko505f5dc2016-03-25 14:22:02 -0700113static void kasan_unpoison_element(mempool_t *pool, void *element, gfp_t flags)
Andrey Ryabinin92393612015-04-15 16:15:05 -0700114{
Andrey Ryabinin9b75a862016-06-24 14:49:34 -0700115 if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
116 kasan_unpoison_slab(element);
Andrey Ryabinin92393612015-04-15 16:15:05 -0700117 if (pool->alloc == mempool_alloc_pages)
118 kasan_alloc_pages(element, (unsigned long)pool->pool_data);
119}
120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121static void add_element(mempool_t *pool, void *element)
122{
123 BUG_ON(pool->curr_nr >= pool->min_nr);
David Rientjesbdfedb72015-04-15 16:14:17 -0700124 poison_element(pool, element);
Andrey Ryabinin92393612015-04-15 16:15:05 -0700125 kasan_poison_element(pool, element);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 pool->elements[pool->curr_nr++] = element;
127}
128
Alexander Potapenko505f5dc2016-03-25 14:22:02 -0700129static void *remove_element(mempool_t *pool, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130{
David Rientjesbdfedb72015-04-15 16:14:17 -0700131 void *element = pool->elements[--pool->curr_nr];
132
133 BUG_ON(pool->curr_nr < 0);
Alexander Potapenko505f5dc2016-03-25 14:22:02 -0700134 kasan_unpoison_element(pool, element, flags);
Matthew Dawson76401312016-03-11 13:08:07 -0800135 check_element(pool, element);
David Rientjesbdfedb72015-04-15 16:14:17 -0700136 return element;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137}
138
Tejun Heo0565d312012-01-10 15:08:26 -0800139/**
140 * mempool_destroy - deallocate a memory pool
141 * @pool: pointer to the memory pool which was allocated via
142 * mempool_create().
143 *
144 * Free all reserved elements in @pool and @pool itself. This function
145 * only sleeps if the free_fn() function sleeps.
146 */
147void mempool_destroy(mempool_t *pool)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148{
Sergey Senozhatsky4e3ca3e2015-09-08 15:00:53 -0700149 if (unlikely(!pool))
150 return;
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 while (pool->curr_nr) {
Alexander Potapenko505f5dc2016-03-25 14:22:02 -0700153 void *element = remove_element(pool, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 pool->free(element, pool->pool_data);
155 }
156 kfree(pool->elements);
157 kfree(pool);
158}
Tejun Heo0565d312012-01-10 15:08:26 -0800159EXPORT_SYMBOL(mempool_destroy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
161/**
162 * mempool_create - create a memory pool
163 * @min_nr: the minimum number of elements guaranteed to be
164 * allocated for this pool.
165 * @alloc_fn: user-defined element-allocation function.
166 * @free_fn: user-defined element-freeing function.
167 * @pool_data: optional private data available to the user-defined functions.
168 *
169 * this function creates and allocates a guaranteed size, preallocated
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800170 * memory pool. The pool can be used from the mempool_alloc() and mempool_free()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 * functions. This function might sleep. Both the alloc_fn() and the free_fn()
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800172 * functions might sleep - as long as the mempool_alloc() function is not called
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 * from IRQ contexts.
174 */
Christoph Lameter19460892005-06-23 00:08:19 -0700175mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 mempool_free_t *free_fn, void *pool_data)
177{
Tejun Heoa91a5ac2012-06-04 20:40:53 -0700178 return mempool_create_node(min_nr,alloc_fn,free_fn, pool_data,
179 GFP_KERNEL, NUMA_NO_NODE);
Christoph Lameter19460892005-06-23 00:08:19 -0700180}
181EXPORT_SYMBOL(mempool_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
Christoph Lameter19460892005-06-23 00:08:19 -0700183mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
Tejun Heoa91a5ac2012-06-04 20:40:53 -0700184 mempool_free_t *free_fn, void *pool_data,
185 gfp_t gfp_mask, int node_id)
Christoph Lameter19460892005-06-23 00:08:19 -0700186{
187 mempool_t *pool;
Joe Perches7b5219d2013-09-11 14:23:07 -0700188 pool = kzalloc_node(sizeof(*pool), gfp_mask, node_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 if (!pool)
190 return NULL;
Christoph Lameter19460892005-06-23 00:08:19 -0700191 pool->elements = kmalloc_node(min_nr * sizeof(void *),
Tejun Heoa91a5ac2012-06-04 20:40:53 -0700192 gfp_mask, node_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 if (!pool->elements) {
194 kfree(pool);
195 return NULL;
196 }
197 spin_lock_init(&pool->lock);
198 pool->min_nr = min_nr;
199 pool->pool_data = pool_data;
200 init_waitqueue_head(&pool->wait);
201 pool->alloc = alloc_fn;
202 pool->free = free_fn;
203
204 /*
205 * First pre-allocate the guaranteed number of buffers.
206 */
207 while (pool->curr_nr < pool->min_nr) {
208 void *element;
209
Tejun Heoa91a5ac2012-06-04 20:40:53 -0700210 element = pool->alloc(gfp_mask, pool->pool_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 if (unlikely(!element)) {
Tejun Heo0565d312012-01-10 15:08:26 -0800212 mempool_destroy(pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 return NULL;
214 }
215 add_element(pool, element);
216 }
217 return pool;
218}
Christoph Lameter19460892005-06-23 00:08:19 -0700219EXPORT_SYMBOL(mempool_create_node);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221/**
222 * mempool_resize - resize an existing memory pool
223 * @pool: pointer to the memory pool which was allocated via
224 * mempool_create().
225 * @new_min_nr: the new minimum number of elements guaranteed to be
226 * allocated for this pool.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 *
228 * This function shrinks/grows the pool. In the case of growing,
229 * it cannot be guaranteed that the pool will be grown to the new
230 * size immediately, but new mempool_free() calls will refill it.
David Rientjes11d83362015-04-14 15:48:21 -0700231 * This function may sleep.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 *
233 * Note, the caller must guarantee that no mempool_destroy is called
234 * while this function is running. mempool_alloc() & mempool_free()
235 * might be called (eg. from IRQ contexts) while this function executes.
236 */
David Rientjes11d83362015-04-14 15:48:21 -0700237int mempool_resize(mempool_t *pool, int new_min_nr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238{
239 void *element;
240 void **new_elements;
241 unsigned long flags;
242
243 BUG_ON(new_min_nr <= 0);
David Rientjes11d83362015-04-14 15:48:21 -0700244 might_sleep();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
246 spin_lock_irqsave(&pool->lock, flags);
247 if (new_min_nr <= pool->min_nr) {
248 while (new_min_nr < pool->curr_nr) {
Alexander Potapenko505f5dc2016-03-25 14:22:02 -0700249 element = remove_element(pool, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 spin_unlock_irqrestore(&pool->lock, flags);
251 pool->free(element, pool->pool_data);
252 spin_lock_irqsave(&pool->lock, flags);
253 }
254 pool->min_nr = new_min_nr;
255 goto out_unlock;
256 }
257 spin_unlock_irqrestore(&pool->lock, flags);
258
259 /* Grow the pool */
David Rientjes11d83362015-04-14 15:48:21 -0700260 new_elements = kmalloc_array(new_min_nr, sizeof(*new_elements),
261 GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 if (!new_elements)
263 return -ENOMEM;
264
265 spin_lock_irqsave(&pool->lock, flags);
266 if (unlikely(new_min_nr <= pool->min_nr)) {
267 /* Raced, other resize will do our work */
268 spin_unlock_irqrestore(&pool->lock, flags);
269 kfree(new_elements);
270 goto out;
271 }
272 memcpy(new_elements, pool->elements,
273 pool->curr_nr * sizeof(*new_elements));
274 kfree(pool->elements);
275 pool->elements = new_elements;
276 pool->min_nr = new_min_nr;
277
278 while (pool->curr_nr < pool->min_nr) {
279 spin_unlock_irqrestore(&pool->lock, flags);
David Rientjes11d83362015-04-14 15:48:21 -0700280 element = pool->alloc(GFP_KERNEL, pool->pool_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 if (!element)
282 goto out;
283 spin_lock_irqsave(&pool->lock, flags);
284 if (pool->curr_nr < pool->min_nr) {
285 add_element(pool, element);
286 } else {
287 spin_unlock_irqrestore(&pool->lock, flags);
288 pool->free(element, pool->pool_data); /* Raced */
289 goto out;
290 }
291 }
292out_unlock:
293 spin_unlock_irqrestore(&pool->lock, flags);
294out:
295 return 0;
296}
297EXPORT_SYMBOL(mempool_resize);
298
299/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 * mempool_alloc - allocate an element from a specific memory pool
301 * @pool: pointer to the memory pool which was allocated via
302 * mempool_create().
303 * @gfp_mask: the usual allocation bitmask.
304 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800305 * this function only sleeps if the alloc_fn() function sleeps or
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 * returns NULL. Note that due to preallocation, this function
307 * *never* fails when called from process contexts. (it might
308 * fail if called from an IRQ context.)
Michal Hocko4e390b22016-07-28 15:48:44 -0700309 * Note: using __GFP_ZERO is not supported.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 */
David Rientjesf9054c72016-03-17 14:19:19 -0700311void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312{
313 void *element;
314 unsigned long flags;
Ingo Molnarac6424b2017-06-20 12:06:13 +0200315 wait_queue_entry_t wait;
Al Viro6daa0e22005-10-21 03:18:50 -0400316 gfp_t gfp_temp;
Nick Piggin20a77772005-05-01 08:58:37 -0700317
Sebastian Ott8bf8fcb2014-06-04 16:07:00 -0700318 VM_WARN_ON_ONCE(gfp_mask & __GFP_ZERO);
Mel Gormand0164ad2015-11-06 16:28:21 -0800319 might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM);
Nick Pigginb84a35b2005-05-01 08:58:36 -0700320
Michal Hocko4e390b22016-07-28 15:48:44 -0700321 gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */
Nick Pigginb84a35b2005-05-01 08:58:36 -0700322 gfp_mask |= __GFP_NORETRY; /* don't loop in __alloc_pages */
323 gfp_mask |= __GFP_NOWARN; /* failures are OK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324
Mel Gormand0164ad2015-11-06 16:28:21 -0800325 gfp_temp = gfp_mask & ~(__GFP_DIRECT_RECLAIM|__GFP_IO);
Nick Piggin20a77772005-05-01 08:58:37 -0700326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327repeat_alloc:
Nick Piggin20a77772005-05-01 08:58:37 -0700328
329 element = pool->alloc(gfp_temp, pool->pool_data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 if (likely(element != NULL))
331 return element;
332
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 spin_lock_irqsave(&pool->lock, flags);
334 if (likely(pool->curr_nr)) {
Alexander Potapenko505f5dc2016-03-25 14:22:02 -0700335 element = remove_element(pool, gfp_temp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 spin_unlock_irqrestore(&pool->lock, flags);
Tejun Heo5b990542012-01-10 15:08:23 -0800337 /* paired with rmb in mempool_free(), read comment there */
338 smp_wmb();
Catalin Marinas17411962014-06-06 14:38:19 -0700339 /*
340 * Update the allocation stack trace as this is more useful
341 * for debugging.
342 */
343 kmemleak_update_trace(element);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 return element;
345 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
Tejun Heo1ebb7042012-01-10 15:08:28 -0800347 /*
Mel Gormand0164ad2015-11-06 16:28:21 -0800348 * We use gfp mask w/o direct reclaim or IO for the first round. If
Tejun Heo1ebb7042012-01-10 15:08:28 -0800349 * alloc failed with that and @pool was empty, retry immediately.
350 */
Michal Hocko4e390b22016-07-28 15:48:44 -0700351 if (gfp_temp != gfp_mask) {
Tejun Heo1ebb7042012-01-10 15:08:28 -0800352 spin_unlock_irqrestore(&pool->lock, flags);
353 gfp_temp = gfp_mask;
354 goto repeat_alloc;
355 }
356
Mel Gormand0164ad2015-11-06 16:28:21 -0800357 /* We must not sleep if !__GFP_DIRECT_RECLAIM */
358 if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) {
Tejun Heo5b990542012-01-10 15:08:23 -0800359 spin_unlock_irqrestore(&pool->lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 return NULL;
Tejun Heo5b990542012-01-10 15:08:23 -0800361 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
Tejun Heo5b990542012-01-10 15:08:23 -0800363 /* Let's wait for someone else to return an element to @pool */
Benjamin LaHaise01890a42005-06-23 00:10:01 -0700364 init_wait(&wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366
Tejun Heo5b990542012-01-10 15:08:23 -0800367 spin_unlock_irqrestore(&pool->lock, flags);
368
369 /*
370 * FIXME: this should be io_schedule(). The timeout is there as a
371 * workaround for some DM problems in 2.6.18.
372 */
373 io_schedule_timeout(5*HZ);
374
375 finish_wait(&pool->wait, &wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 goto repeat_alloc;
377}
378EXPORT_SYMBOL(mempool_alloc);
379
380/**
381 * mempool_free - return an element to the pool.
382 * @element: pool element pointer.
383 * @pool: pointer to the memory pool which was allocated via
384 * mempool_create().
385 *
386 * this function only sleeps if the free_fn() function sleeps.
387 */
388void mempool_free(void *element, mempool_t *pool)
389{
390 unsigned long flags;
391
Rusty Russellc80e7a82007-07-15 23:42:00 -0700392 if (unlikely(element == NULL))
393 return;
394
Tejun Heo5b990542012-01-10 15:08:23 -0800395 /*
396 * Paired with the wmb in mempool_alloc(). The preceding read is
397 * for @element and the following @pool->curr_nr. This ensures
398 * that the visible value of @pool->curr_nr is from after the
399 * allocation of @element. This is necessary for fringe cases
400 * where @element was passed to this task without going through
401 * barriers.
402 *
403 * For example, assume @p is %NULL at the beginning and one task
404 * performs "p = mempool_alloc(...);" while another task is doing
405 * "while (!p) cpu_relax(); mempool_free(p, ...);". This function
406 * may end up using curr_nr value which is from before allocation
407 * of @p without the following rmb.
408 */
409 smp_rmb();
410
411 /*
412 * For correctness, we need a test which is guaranteed to trigger
413 * if curr_nr + #allocated == min_nr. Testing curr_nr < min_nr
414 * without locking achieves that and refilling as soon as possible
415 * is desirable.
416 *
417 * Because curr_nr visible here is always a value after the
418 * allocation of @element, any task which decremented curr_nr below
419 * min_nr is guaranteed to see curr_nr < min_nr unless curr_nr gets
420 * incremented to min_nr afterwards. If curr_nr gets incremented
421 * to min_nr after the allocation of @element, the elements
422 * allocated after that are subject to the same guarantee.
423 *
424 * Waiters happen iff curr_nr is 0 and the above guarantee also
425 * ensures that there will be frees which return elements to the
426 * pool waking up the waiters.
427 */
Mikulas Patockaeb9a3c62014-04-07 15:37:35 -0700428 if (unlikely(pool->curr_nr < pool->min_nr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 spin_lock_irqsave(&pool->lock, flags);
Mikulas Patockaeb9a3c62014-04-07 15:37:35 -0700430 if (likely(pool->curr_nr < pool->min_nr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 add_element(pool, element);
432 spin_unlock_irqrestore(&pool->lock, flags);
433 wake_up(&pool->wait);
434 return;
435 }
436 spin_unlock_irqrestore(&pool->lock, flags);
437 }
438 pool->free(element, pool->pool_data);
439}
440EXPORT_SYMBOL(mempool_free);
441
442/*
443 * A commonly used alloc and free fn.
444 */
Al Virodd0fc662005-10-07 07:46:04 +0100445void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446{
Pekka Enbergfcc234f2006-03-22 00:08:13 -0800447 struct kmem_cache *mem = pool_data;
David Rientjese244c9e2015-04-15 16:14:14 -0700448 VM_BUG_ON(mem->ctor);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 return kmem_cache_alloc(mem, gfp_mask);
450}
451EXPORT_SYMBOL(mempool_alloc_slab);
452
453void mempool_free_slab(void *element, void *pool_data)
454{
Pekka Enbergfcc234f2006-03-22 00:08:13 -0800455 struct kmem_cache *mem = pool_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 kmem_cache_free(mem, element);
457}
458EXPORT_SYMBOL(mempool_free_slab);
Matthew Dobson6e0678f2006-03-26 01:37:44 -0800459
460/*
Matthew Dobson53184082006-03-26 01:37:46 -0800461 * A commonly used alloc and free fn that kmalloc/kfrees the amount of memory
Simon Arlott183ff222007-10-20 01:27:18 +0200462 * specified by pool_data
Matthew Dobson53184082006-03-26 01:37:46 -0800463 */
464void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
465{
Figo.zhang5e2f89b2009-08-08 21:01:22 +0800466 size_t size = (size_t)pool_data;
Matthew Dobson53184082006-03-26 01:37:46 -0800467 return kmalloc(size, gfp_mask);
468}
469EXPORT_SYMBOL(mempool_kmalloc);
470
471void mempool_kfree(void *element, void *pool_data)
472{
473 kfree(element);
474}
475EXPORT_SYMBOL(mempool_kfree);
476
477/*
Matthew Dobson6e0678f2006-03-26 01:37:44 -0800478 * A simple mempool-backed page allocator that allocates pages
479 * of the order specified by pool_data.
480 */
481void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data)
482{
483 int order = (int)(long)pool_data;
484 return alloc_pages(gfp_mask, order);
485}
486EXPORT_SYMBOL(mempool_alloc_pages);
487
488void mempool_free_pages(void *element, void *pool_data)
489{
490 int order = (int)(long)pool_data;
491 __free_pages(element, order);
492}
493EXPORT_SYMBOL(mempool_free_pages);