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 posix_memalign(&p, cachep->align, cachep->size);
101 else
102 p = malloc(cachep->size);
103 if (cachep->ctor)
104 cachep->ctor(p);
105 else if (gfp & __GFP_ZERO)
106 memset(p, 0, cachep->size);
107 }
108
109 uatomic_inc(&cachep->nr_allocated);
110 uatomic_inc(&nr_allocated);
111 uatomic_inc(&cachep->nr_tallocated);
112 if (kmalloc_verbose)
113 printf("Allocating %p from slab\n", p);
114 return p;
115 }
116
117 void __kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
118 {
119 assert(objp);
120 if (cachep->nr_objs > 10 || cachep->align) {
121 memset(objp, POISON_FREE, cachep->size);
122 free(objp);
123 } else {
124 struct radix_tree_node *node = objp;
125 cachep->nr_objs++;
126 node->parent = cachep->objs;
127 cachep->objs = node;
128 }
129 }
130
131 void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
132 {
133 uatomic_dec(&nr_allocated);
134 uatomic_dec(&cachep->nr_allocated);
135 if (kmalloc_verbose)
136 printf("Freeing %p to slab\n", objp);
137 __kmem_cache_free_locked(cachep, objp);
138 }
139
140 void kmem_cache_free(struct kmem_cache *cachep, void *objp)
141 {
142 pthread_mutex_lock(&cachep->lock);
143 kmem_cache_free_locked(cachep, objp);
144 pthread_mutex_unlock(&cachep->lock);
145 }
146
147 void kmem_cache_free_bulk(struct kmem_cache *cachep, size_t size, void **list)
148 {
149 if (kmalloc_verbose)
150 pr_debug("Bulk free %p[0-%lu]\n", list, size - 1);
151
152 pthread_mutex_lock(&cachep->lock);
153 for (int i = 0; i < size; i++)
154 kmem_cache_free_locked(cachep, list[i]);
155 pthread_mutex_unlock(&cachep->lock);
156 }
157
158 void kmem_cache_shrink(struct kmem_cache *cachep)
159 {
160 }
161
162 int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
163 void **p)
164 {
165 size_t i;
166
167 if (kmalloc_verbose)
168 pr_debug("Bulk alloc %lu\n", size);
169
170 pthread_mutex_lock(&cachep->lock);
171 if (cachep->nr_objs >= size) {
172 struct radix_tree_node *node;
173
174 for (i = 0; i < size; i++) {
175 if (!(gfp & __GFP_DIRECT_RECLAIM)) {
176 if (!cachep->non_kernel)
177 break;
178 cachep->non_kernel--;
179 }
180
181 node = cachep->objs;
182 cachep->nr_objs--;
183 cachep->objs = node->parent;
184 p[i] = node;
185 node->parent = NULL;
186 }
187 pthread_mutex_unlock(&cachep->lock);
188 } else {
189 pthread_mutex_unlock(&cachep->lock);
190 for (i = 0; i < size; i++) {
191 if (!(gfp & __GFP_DIRECT_RECLAIM)) {
192 if (!cachep->non_kernel)
193 break;
194 cachep->non_kernel--;
195 }
196
197 if (cachep->align) {
198 posix_memalign(&p[i], cachep->align,
199 cachep->size);
200 } else {
201 p[i] = malloc(cachep->size);
202 if (!p[i])
203 break;
204 }
205 if (cachep->ctor)
206 cachep->ctor(p[i]);
207 else if (gfp & __GFP_ZERO)
208 memset(p[i], 0, cachep->size);
209 }
210 }
211
212 if (i < size) {
213 size = i;
214 pthread_mutex_lock(&cachep->lock);
215 for (i = 0; i < size; i++)
216 __kmem_cache_free_locked(cachep, p[i]);
217 pthread_mutex_unlock(&cachep->lock);
218 return 0;
219 }
220
221 for (i = 0; i < size; i++) {
222 uatomic_inc(&nr_allocated);
223 uatomic_inc(&cachep->nr_allocated);
224 uatomic_inc(&cachep->nr_tallocated);
225 if (kmalloc_verbose)
226 printf("Allocating %p from slab\n", p[i]);
227 }
228
229 return size;
230 }
231
232 struct kmem_cache *
233 kmem_cache_create(const char *name, unsigned int size, unsigned int align,
234 unsigned int flags, void (*ctor)(void *))
235 {
236 struct kmem_cache *ret = malloc(sizeof(*ret));
237
238 pthread_mutex_init(&ret->lock, NULL);
239 ret->size = size;
240 ret->align = align;
241 ret->nr_objs = 0;
242 ret->nr_allocated = 0;
243 ret->nr_tallocated = 0;
244 ret->objs = NULL;
245 ret->ctor = ctor;
246 ret->non_kernel = 0;
247 ret->exec_callback = false;
248 ret->callback = NULL;
249 ret->private = NULL;
250 return ret;
251 }
252
253 /*
254 * Test the test infrastructure for kem_cache_alloc/free and bulk counterparts.
255 */
256 void test_kmem_cache_bulk(void)
257 {
258 int i;
259 void *list[12];
260 static struct kmem_cache *test_cache, *test_cache2;
261
262 /*
263 * Testing the bulk allocators without aligned kmem_cache to force the
264 * bulk alloc/free to reuse
265 */
266 test_cache = kmem_cache_create("test_cache", 256, 0, SLAB_PANIC, NULL);
267
268 for (i = 0; i < 5; i++)
269 list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
270
271 for (i = 0; i < 5; i++)
272 kmem_cache_free(test_cache, list[i]);
273 assert(test_cache->nr_objs == 5);
274
275 kmem_cache_alloc_bulk(test_cache, __GFP_DIRECT_RECLAIM, 5, list);
276 kmem_cache_free_bulk(test_cache, 5, list);
277
278 for (i = 0; i < 12 ; i++)
279 list[i] = kmem_cache_alloc(test_cache, __GFP_DIRECT_RECLAIM);
280
281 for (i = 0; i < 12; i++)
282 kmem_cache_free(test_cache, list[i]);
283
284 /* The last free will not be kept around */
285 assert(test_cache->nr_objs == 11);
286
287 /* Aligned caches will immediately free */
288 test_cache2 = kmem_cache_create("test_cache2", 128, 128, SLAB_PANIC, NULL);
289
290 kmem_cache_alloc_bulk(test_cache2, __GFP_DIRECT_RECLAIM, 10, list);
291 kmem_cache_free_bulk(test_cache2, 10, list);
292 assert(!test_cache2->nr_objs);
293
294
295 }
296
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