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 9 #include <linux/gfp.h> 10 #include <linux/poison.h> 11 #include <linux/slab.h> 12 #include <linux/radix-tree.h> 13 #include <urcu/uatomic.h> 14 15 int nr_allocated; 16 int preempt_count; 17 int test_verbose; 18 19 struct kmem_cache { 20 pthread_mutex_t lock; 21 unsigned int size; 22 unsigned int align; 23 int nr_objs; 24 void *objs; 25 void (*ctor)(void *); 26 unsigned int non_kernel; 27 unsigned long nr_allocated; 28 unsigned long nr_tallocated; 29 bool exec_callback; 30 void (*callback)(void *); 31 void *private; 32 }; 33 34 void kmem_cache_set_callback(struct kmem_cache *cachep, void (*callback)(void *)) 35 { 36 cachep->callback = callback; 37 } 38 39 void kmem_cache_set_private(struct kmem_cache *cachep, void *private) 40 { 41 cachep->private = private; 42 } 43 44 void kmem_cache_set_non_kernel(struct kmem_cache *cachep, unsigned int val) 45 { 46 cachep->non_kernel = val; 47 } 48 49 unsigned long kmem_cache_get_alloc(struct kmem_cache *cachep) 50 { 51 return cachep->size * cachep->nr_allocated; 52 } 53 54 unsigned long kmem_cache_nr_allocated(struct kmem_cache *cachep) 55 { 56 return cachep->nr_allocated; 57 } 58 59 unsigned long kmem_cache_nr_tallocated(struct kmem_cache *cachep) 60 { 61 return cachep->nr_tallocated; 62 } 63 64 void kmem_cache_zero_nr_tallocated(struct kmem_cache *cachep) 65 { 66 cachep->nr_tallocated = 0; 67 } 68 69 void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru, 70 int gfp) 71 { 72 void *p; 73 74 if (cachep->exec_callback) { 75 if (cachep->callback) 76 cachep->callback(cachep->private); 77 cachep->exec_callback = false; 78 } 79 80 if (!(gfp & __GFP_DIRECT_RECLAIM)) { 81 if (!cachep->non_kernel) { 82 cachep->exec_callback = true; 83 return NULL; 84 } 85 86 cachep->non_kernel--; 87 } 88 89 pthread_mutex_lock(&cachep->lock); 90 if (cachep->nr_objs) { 91 struct radix_tree_node *node = cachep->objs; 92 cachep->nr_objs--; 93 cachep->objs = node->parent; 94 pthread_mutex_unlock(&cachep->lock); 95 node->parent = NULL; 96 p = node; 97 } else { 98 pthread_mutex_unlock(&cachep->lock); 99 if (cachep->align) { 100 if (posix_memalign(&p, cachep->align, cachep->size) < 0) 101 return NULL; 102 } else { 103 p = malloc(cachep->size); 104 } 105 106 if (cachep->ctor) 107 cachep->ctor(p); 108 else if (gfp & __GFP_ZERO) 109 memset(p, 0, cachep->size); 110 } 111 112 uatomic_inc(&cachep->nr_allocated); 113 uatomic_inc(&nr_allocated); 114 uatomic_inc(&cachep->nr_tallocated); 115 if (kmalloc_verbose) 116 printf("Allocating %p from slab\n", p); 117 return p; 118 } 119 120 void __kmem_cache_free_locked(struct kmem_cache *cachep, void *objp) 121 { 122 assert(objp); 123 if (cachep->nr_objs > 10 || cachep->align) { 124 memset(objp, POISON_FREE, cachep->size); 125 free(objp); 126 } else { 127 struct radix_tree_node *node = objp; 128 cachep->nr_objs++; 129 node->parent = cachep->objs; 130 cachep->objs = node; 131 } 132 } 133 134 void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp) 135 { 136 uatomic_dec(&nr_allocated); 137 uatomic_dec(&cachep->nr_allocated); 138 if (kmalloc_verbose) 139 printf("Freeing %p to slab\n", objp); 140 __kmem_cache_free_locked(cachep, objp); 141 } 142 143 void kmem_cache_free(struct kmem_cache *cachep, void *objp) 144 { 145 pthread_mutex_lock(&cachep->lock); 146 kmem_cache_free_locked(cachep, objp); 147 pthread_mutex_unlock(&cachep->lock); 148 } 149 150 void kmem_cache_free_bulk(struct kmem_cache *cachep, size_t size, void **list) 151 { 152 if (kmalloc_verbose) 153 pr_debug("Bulk free %p[0-%lu]\n", list, size - 1); 154 155 pthread_mutex_lock(&cachep->lock); 156 for (int i = 0; i < size; i++) 157 kmem_cache_free_locked(cachep, list[i]); 158 pthread_mutex_unlock(&cachep->lock); 159 } 160 161 void kmem_cache_shrink(struct kmem_cache *cachep) 162 { 163 } 164 165 int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size, 166 void **p) 167 { 168 size_t i; 169 170 if (kmalloc_verbose) 171 pr_debug("Bulk alloc %lu\n", size); 172 173 pthread_mutex_lock(&cachep->lock); 174 if (cachep->nr_objs >= size) { 175 struct radix_tree_node *node; 176 177 for (i = 0; i < size; i++) { 178 if (!(gfp & __GFP_DIRECT_RECLAIM)) { 179 if (!cachep->non_kernel) 180 break; 181 cachep->non_kernel--; 182 } 183 184 node = cachep->objs; 185 cachep->nr_objs--; 186 cachep->objs = node->parent; 187 p[i] = node; 188 node->parent = NULL; 189 } 190 pthread_mutex_unlock(&cachep->lock); 191 } else { 192 pthread_mutex_unlock(&cachep->lock); 193 for (i = 0; i < size; i++) { 194 if (!(gfp & __GFP_DIRECT_RECLAIM)) { 195 if (!cachep->non_kernel) 196 break; 197 cachep->non_kernel--; 198 } 199 200 if (cachep->align) { 201 if (posix_memalign(&p[i], cachep->align, 202 cachep->size) < 0) 203 break; 204 } else { 205 p[i] = malloc(cachep->size); 206 if (!p[i]) 207 break; 208 } 209 if (cachep->ctor) 210 cachep->ctor(p[i]); 211 else if (gfp & __GFP_ZERO) 212 memset(p[i], 0, cachep->size); 213 } 214 } 215 216 if (i < size) { 217 size = i; 218 pthread_mutex_lock(&cachep->lock); 219 for (i = 0; i < size; i++) 220 __kmem_cache_free_locked(cachep, p[i]); 221 pthread_mutex_unlock(&cachep->lock); 222 return 0; 223 } 224 225 for (i = 0; i < size; i++) { 226 uatomic_inc(&nr_allocated); 227 uatomic_inc(&cachep->nr_allocated); 228 uatomic_inc(&cachep->nr_tallocated); 229 if (kmalloc_verbose) 230 printf("Allocating %p from slab\n", p[i]); 231 } 232 233 return size; 234 } 235 236 struct kmem_cache * 237 kmem_cache_create(const char *name, unsigned int size, unsigned int align, 238 unsigned int flags, void (*ctor)(void *)) 239 { 240 struct kmem_cache *ret = malloc(sizeof(*ret)); 241 242 pthread_mutex_init(&ret->lock, NULL); 243 ret->size = size; 244 ret->align = align; 245 ret->nr_objs = 0; 246 ret->nr_allocated = 0; 247 ret->nr_tallocated = 0; 248 ret->objs = NULL; 249 ret->ctor = ctor; 250 ret->non_kernel = 0; 251 ret->exec_callback = false; 252 ret->callback = NULL; 253 ret->private = NULL; 254 return ret; 255 } 256 257 /* 258 * Test the test infrastructure for kem_cache_alloc/free and bulk counterparts. 259 */ 260 void test_kmem_cache_bulk(void) 261 { 262 int i; 263 void *list[12]; 264 static struct kmem_cache *test_cache, *test_cache2; 265 266 /* 267 * Testing the bulk allocators without aligned kmem_cache to force the 268 * bulk alloc/free to reuse 269 */ 270 test_cache = kmem_cache_create("test_cache", 256, 0, SLAB_PANIC, NULL); 271 272 for (i = 0; i < 5; i++) 273 list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM); 274 275 for (i = 0; i < 5; i++) 276 kmem_cache_free(test_cache, list[i]); 277 assert(test_cache->nr_objs == 5); 278 279 kmem_cache_alloc_bulk(test_cache, __GFP_DIRECT_RECLAIM, 5, list); 280 kmem_cache_free_bulk(test_cache, 5, list); 281 282 for (i = 0; i < 12 ; i++) 283 list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM); 284 285 for (i = 0; i < 12; i++) 286 kmem_cache_free(test_cache, list[i]); 287 288 /* The last free will not be kept around */ 289 assert(test_cache->nr_objs == 11); 290 291 /* Aligned caches will immediately free */ 292 test_cache2 = kmem_cache_create("test_cache2", 128, 128, SLAB_PANIC, NULL); 293 294 kmem_cache_alloc_bulk(test_cache2, __GFP_DIRECT_RECLAIM, 10, list); 295 kmem_cache_free_bulk(test_cache2, 10, list); 296 assert(!test_cache2->nr_objs); 297 298 299 } 300