linux.c 6.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295
  1. // SPDX-License-Identifier: GPL-2.0
  2. #include <stdlib.h>
  3. #include <string.h>
  4. #include <malloc.h>
  5. #include <pthread.h>
  6. #include <unistd.h>
  7. #include <assert.h>
  8. #include <linux/gfp.h>
  9. #include <linux/poison.h>
  10. #include <linux/slab.h>
  11. #include <linux/radix-tree.h>
  12. #include <urcu/uatomic.h>
  13. int nr_allocated;
  14. int preempt_count;
  15. int test_verbose;
  16. struct kmem_cache {
  17. pthread_mutex_t lock;
  18. unsigned int size;
  19. unsigned int align;
  20. int nr_objs;
  21. void *objs;
  22. void (*ctor)(void *);
  23. unsigned int non_kernel;
  24. unsigned long nr_allocated;
  25. unsigned long nr_tallocated;
  26. bool exec_callback;
  27. void (*callback)(void *);
  28. void *private;
  29. };
  30. void kmem_cache_set_callback(struct kmem_cache *cachep, void (*callback)(void *))
  31. {
  32. cachep->callback = callback;
  33. }
  34. void kmem_cache_set_private(struct kmem_cache *cachep, void *private)
  35. {
  36. cachep->private = private;
  37. }
  38. void kmem_cache_set_non_kernel(struct kmem_cache *cachep, unsigned int val)
  39. {
  40. cachep->non_kernel = val;
  41. }
  42. unsigned long kmem_cache_get_alloc(struct kmem_cache *cachep)
  43. {
  44. return cachep->size * cachep->nr_allocated;
  45. }
  46. unsigned long kmem_cache_nr_allocated(struct kmem_cache *cachep)
  47. {
  48. return cachep->nr_allocated;
  49. }
  50. unsigned long kmem_cache_nr_tallocated(struct kmem_cache *cachep)
  51. {
  52. return cachep->nr_tallocated;
  53. }
  54. void kmem_cache_zero_nr_tallocated(struct kmem_cache *cachep)
  55. {
  56. cachep->nr_tallocated = 0;
  57. }
  58. void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
  59. int gfp)
  60. {
  61. void *p;
  62. if (cachep->exec_callback) {
  63. if (cachep->callback)
  64. cachep->callback(cachep->private);
  65. cachep->exec_callback = false;
  66. }
  67. if (!(gfp & __GFP_DIRECT_RECLAIM)) {
  68. if (!cachep->non_kernel) {
  69. cachep->exec_callback = true;
  70. return NULL;
  71. }
  72. cachep->non_kernel--;
  73. }
  74. pthread_mutex_lock(&cachep->lock);
  75. if (cachep->nr_objs) {
  76. struct radix_tree_node *node = cachep->objs;
  77. cachep->nr_objs--;
  78. cachep->objs = node->parent;
  79. pthread_mutex_unlock(&cachep->lock);
  80. node->parent = NULL;
  81. p = node;
  82. } else {
  83. pthread_mutex_unlock(&cachep->lock);
  84. if (cachep->align)
  85. posix_memalign(&p, cachep->align, cachep->size);
  86. else
  87. p = malloc(cachep->size);
  88. if (cachep->ctor)
  89. cachep->ctor(p);
  90. else if (gfp & __GFP_ZERO)
  91. memset(p, 0, cachep->size);
  92. }
  93. uatomic_inc(&cachep->nr_allocated);
  94. uatomic_inc(&nr_allocated);
  95. uatomic_inc(&cachep->nr_tallocated);
  96. if (kmalloc_verbose)
  97. printf("Allocating %p from slab\n", p);
  98. return p;
  99. }
  100. void __kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
  101. {
  102. assert(objp);
  103. if (cachep->nr_objs > 10 || cachep->align) {
  104. memset(objp, POISON_FREE, cachep->size);
  105. free(objp);
  106. } else {
  107. struct radix_tree_node *node = objp;
  108. cachep->nr_objs++;
  109. node->parent = cachep->objs;
  110. cachep->objs = node;
  111. }
  112. }
  113. void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
  114. {
  115. uatomic_dec(&nr_allocated);
  116. uatomic_dec(&cachep->nr_allocated);
  117. if (kmalloc_verbose)
  118. printf("Freeing %p to slab\n", objp);
  119. __kmem_cache_free_locked(cachep, objp);
  120. }
  121. void kmem_cache_free(struct kmem_cache *cachep, void *objp)
  122. {
  123. pthread_mutex_lock(&cachep->lock);
  124. kmem_cache_free_locked(cachep, objp);
  125. pthread_mutex_unlock(&cachep->lock);
  126. }
  127. void kmem_cache_free_bulk(struct kmem_cache *cachep, size_t size, void **list)
  128. {
  129. if (kmalloc_verbose)
  130. pr_debug("Bulk free %p[0-%zu]\n", list, size - 1);
  131. pthread_mutex_lock(&cachep->lock);
  132. for (int i = 0; i < size; i++)
  133. kmem_cache_free_locked(cachep, list[i]);
  134. pthread_mutex_unlock(&cachep->lock);
  135. }
  136. void kmem_cache_shrink(struct kmem_cache *cachep)
  137. {
  138. }
  139. int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
  140. void **p)
  141. {
  142. size_t i;
  143. if (kmalloc_verbose)
  144. pr_debug("Bulk alloc %zu\n", size);
  145. pthread_mutex_lock(&cachep->lock);
  146. if (cachep->nr_objs >= size) {
  147. struct radix_tree_node *node;
  148. for (i = 0; i < size; i++) {
  149. if (!(gfp & __GFP_DIRECT_RECLAIM)) {
  150. if (!cachep->non_kernel)
  151. break;
  152. cachep->non_kernel--;
  153. }
  154. node = cachep->objs;
  155. cachep->nr_objs--;
  156. cachep->objs = node->parent;
  157. p[i] = node;
  158. node->parent = NULL;
  159. }
  160. pthread_mutex_unlock(&cachep->lock);
  161. } else {
  162. pthread_mutex_unlock(&cachep->lock);
  163. for (i = 0; i < size; i++) {
  164. if (!(gfp & __GFP_DIRECT_RECLAIM)) {
  165. if (!cachep->non_kernel)
  166. break;
  167. cachep->non_kernel--;
  168. }
  169. if (cachep->align) {
  170. posix_memalign(&p[i], cachep->align,
  171. cachep->size);
  172. } else {
  173. p[i] = malloc(cachep->size);
  174. if (!p[i])
  175. break;
  176. }
  177. if (cachep->ctor)
  178. cachep->ctor(p[i]);
  179. else if (gfp & __GFP_ZERO)
  180. memset(p[i], 0, cachep->size);
  181. }
  182. }
  183. if (i < size) {
  184. size = i;
  185. pthread_mutex_lock(&cachep->lock);
  186. for (i = 0; i < size; i++)
  187. __kmem_cache_free_locked(cachep, p[i]);
  188. pthread_mutex_unlock(&cachep->lock);
  189. return 0;
  190. }
  191. for (i = 0; i < size; i++) {
  192. uatomic_inc(&nr_allocated);
  193. uatomic_inc(&cachep->nr_allocated);
  194. uatomic_inc(&cachep->nr_tallocated);
  195. if (kmalloc_verbose)
  196. printf("Allocating %p from slab\n", p[i]);
  197. }
  198. return size;
  199. }
  200. struct kmem_cache *
  201. kmem_cache_create(const char *name, unsigned int size, unsigned int align,
  202. unsigned int flags, void (*ctor)(void *))
  203. {
  204. struct kmem_cache *ret = malloc(sizeof(*ret));
  205. pthread_mutex_init(&ret->lock, NULL);
  206. ret->size = size;
  207. ret->align = align;
  208. ret->nr_objs = 0;
  209. ret->nr_allocated = 0;
  210. ret->nr_tallocated = 0;
  211. ret->objs = NULL;
  212. ret->ctor = ctor;
  213. ret->non_kernel = 0;
  214. ret->exec_callback = false;
  215. ret->callback = NULL;
  216. ret->private = NULL;
  217. return ret;
  218. }
  219. /*
  220. * Test the test infrastructure for kem_cache_alloc/free and bulk counterparts.
  221. */
  222. void test_kmem_cache_bulk(void)
  223. {
  224. int i;
  225. void *list[12];
  226. static struct kmem_cache *test_cache, *test_cache2;
  227. /*
  228. * Testing the bulk allocators without aligned kmem_cache to force the
  229. * bulk alloc/free to reuse
  230. */
  231. test_cache = kmem_cache_create("test_cache", 256, 0, SLAB_PANIC, NULL);
  232. for (i = 0; i < 5; i++)
  233. list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
  234. for (i = 0; i < 5; i++)
  235. kmem_cache_free(test_cache, list[i]);
  236. assert(test_cache->nr_objs == 5);
  237. kmem_cache_alloc_bulk(test_cache, __GFP_DIRECT_RECLAIM, 5, list);
  238. kmem_cache_free_bulk(test_cache, 5, list);
  239. for (i = 0; i < 12 ; i++)
  240. list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
  241. for (i = 0; i < 12; i++)
  242. kmem_cache_free(test_cache, list[i]);
  243. /* The last free will not be kept around */
  244. assert(test_cache->nr_objs == 11);
  245. /* Aligned caches will immediately free */
  246. test_cache2 = kmem_cache_create("test_cache2", 128, 128, SLAB_PANIC, NULL);
  247. kmem_cache_alloc_bulk(test_cache2, __GFP_DIRECT_RECLAIM, 10, list);
  248. kmem_cache_free_bulk(test_cache2, 10, list);
  249. assert(!test_cache2->nr_objs);
  250. }