1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/module.h> 3 #include <linux/moduleparam.h> 4 #include <linux/rbtree_augmented.h> 5 #include <linux/random.h> 6 #include <linux/slab.h> 7 #include <asm/timex.h> 8 9 #define __param(type, name, init, msg) \ 10 static type name = init; \ 11 module_param(name, type, 0444); \ 12 MODULE_PARM_DESC(name, msg); 13 14 __param(int, nnodes, 100, "Number of nodes in the rb-tree"); 15 __param(int, perf_loops, 1000, "Number of iterations modifying the rb-tree"); 16 __param(int, check_loops, 100, "Number of iterations modifying and verifying the rb-tree"); 17 18 struct test_node { 19 u32 key; 20 struct rb_node rb; 21 22 /* following fields used for testing augmented rbtree functionality */ 23 u32 val; 24 u32 augmented; 25 }; 26 27 static struct rb_root_cached root = RB_ROOT_CACHED; 28 static struct test_node *nodes = NULL; 29 30 static struct rnd_state rnd; 31 32 static void insert(struct test_node *node, struct rb_root_cached *root) 33 { 34 struct rb_node **new = &root->rb_root.rb_node, *parent = NULL; 35 u32 key = node->key; 36 37 while (*new) { 38 parent = *new; 39 if (key < rb_entry(parent, struct test_node, rb)->key) 40 new = &parent->rb_left; 41 else 42 new = &parent->rb_right; 43 } 44 45 rb_link_node(&node->rb, parent, new); 46 rb_insert_color(&node->rb, &root->rb_root); 47 } 48 49 static void insert_cached(struct test_node *node, struct rb_root_cached *root) 50 { 51 struct rb_node **new = &root->rb_root.rb_node, *parent = NULL; 52 u32 key = node->key; 53 bool leftmost = true; 54 55 while (*new) { 56 parent = *new; 57 if (key < rb_entry(parent, struct test_node, rb)->key) 58 new = &parent->rb_left; 59 else { 60 new = &parent->rb_right; 61 leftmost = false; 62 } 63 } 64 65 rb_link_node(&node->rb, parent, new); 66 rb_insert_color_cached(&node->rb, root, leftmost); 67 } 68 69 static inline void erase(struct test_node *node, struct rb_root_cached *root) 70 { 71 rb_erase(&node->rb, &root->rb_root); 72 } 73 74 static inline void erase_cached(struct test_node *node, struct rb_root_cached *root) 75 { 76 rb_erase_cached(&node->rb, root); 77 } 78 79 80 static inline u32 augment_recompute(struct test_node *node) 81 { 82 u32 max = node->val, child_augmented; 83 if (node->rb.rb_left) { 84 child_augmented = rb_entry(node->rb.rb_left, struct test_node, 85 rb)->augmented; 86 if (max < child_augmented) 87 max = child_augmented; 88 } 89 if (node->rb.rb_right) { 90 child_augmented = rb_entry(node->rb.rb_right, struct test_node, 91 rb)->augmented; 92 if (max < child_augmented) 93 max = child_augmented; 94 } 95 return max; 96 } 97 98 RB_DECLARE_CALLBACKS(static, augment_callbacks, struct test_node, rb, 99 u32, augmented, augment_recompute) 100 101 static void insert_augmented(struct test_node *node, 102 struct rb_root_cached *root) 103 { 104 struct rb_node **new = &root->rb_root.rb_node, *rb_parent = NULL; 105 u32 key = node->key; 106 u32 val = node->val; 107 struct test_node *parent; 108 109 while (*new) { 110 rb_parent = *new; 111 parent = rb_entry(rb_parent, struct test_node, rb); 112 if (parent->augmented < val) 113 parent->augmented = val; 114 if (key < parent->key) 115 new = &parent->rb.rb_left; 116 else 117 new = &parent->rb.rb_right; 118 } 119 120 node->augmented = val; 121 rb_link_node(&node->rb, rb_parent, new); 122 rb_insert_augmented(&node->rb, &root->rb_root, &augment_callbacks); 123 } 124 125 static void insert_augmented_cached(struct test_node *node, 126 struct rb_root_cached *root) 127 { 128 struct rb_node **new = &root->rb_root.rb_node, *rb_parent = NULL; 129 u32 key = node->key; 130 u32 val = node->val; 131 struct test_node *parent; 132 bool leftmost = true; 133 134 while (*new) { 135 rb_parent = *new; 136 parent = rb_entry(rb_parent, struct test_node, rb); 137 if (parent->augmented < val) 138 parent->augmented = val; 139 if (key < parent->key) 140 new = &parent->rb.rb_left; 141 else { 142 new = &parent->rb.rb_right; 143 leftmost = false; 144 } 145 } 146 147 node->augmented = val; 148 rb_link_node(&node->rb, rb_parent, new); 149 rb_insert_augmented_cached(&node->rb, root, 150 leftmost, &augment_callbacks); 151 } 152 153 154 static void erase_augmented(struct test_node *node, struct rb_root_cached *root) 155 { 156 rb_erase_augmented(&node->rb, &root->rb_root, &augment_callbacks); 157 } 158 159 static void erase_augmented_cached(struct test_node *node, 160 struct rb_root_cached *root) 161 { 162 rb_erase_augmented_cached(&node->rb, root, &augment_callbacks); 163 } 164 165 static void init(void) 166 { 167 int i; 168 for (i = 0; i < nnodes; i++) { 169 nodes[i].key = prandom_u32_state(&rnd); 170 nodes[i].val = prandom_u32_state(&rnd); 171 } 172 } 173 174 static bool is_red(struct rb_node *rb) 175 { 176 return !(rb->__rb_parent_color & 1); 177 } 178 179 static int black_path_count(struct rb_node *rb) 180 { 181 int count; 182 for (count = 0; rb; rb = rb_parent(rb)) 183 count += !is_red(rb); 184 return count; 185 } 186 187 static void check_postorder_foreach(int nr_nodes) 188 { 189 struct test_node *cur, *n; 190 int count = 0; 191 rbtree_postorder_for_each_entry_safe(cur, n, &root.rb_root, rb) 192 count++; 193 194 WARN_ON_ONCE(count != nr_nodes); 195 } 196 197 static void check_postorder(int nr_nodes) 198 { 199 struct rb_node *rb; 200 int count = 0; 201 for (rb = rb_first_postorder(&root.rb_root); rb; rb = rb_next_postorder(rb)) 202 count++; 203 204 WARN_ON_ONCE(count != nr_nodes); 205 } 206 207 static void check(int nr_nodes) 208 { 209 struct rb_node *rb; 210 int count = 0, blacks = 0; 211 u32 prev_key = 0; 212 213 for (rb = rb_first(&root.rb_root); rb; rb = rb_next(rb)) { 214 struct test_node *node = rb_entry(rb, struct test_node, rb); 215 WARN_ON_ONCE(node->key < prev_key); 216 WARN_ON_ONCE(is_red(rb) && 217 (!rb_parent(rb) || is_red(rb_parent(rb)))); 218 if (!count) 219 blacks = black_path_count(rb); 220 else 221 WARN_ON_ONCE((!rb->rb_left || !rb->rb_right) && 222 blacks != black_path_count(rb)); 223 prev_key = node->key; 224 count++; 225 } 226 227 WARN_ON_ONCE(count != nr_nodes); 228 WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root.rb_root))) - 1); 229 230 check_postorder(nr_nodes); 231 check_postorder_foreach(nr_nodes); 232 } 233 234 static void check_augmented(int nr_nodes) 235 { 236 struct rb_node *rb; 237 238 check(nr_nodes); 239 for (rb = rb_first(&root.rb_root); rb; rb = rb_next(rb)) { 240 struct test_node *node = rb_entry(rb, struct test_node, rb); 241 WARN_ON_ONCE(node->augmented != augment_recompute(node)); 242 } 243 } 244 245 static int __init rbtree_test_init(void) 246 { 247 int i, j; 248 cycles_t time1, time2, time; 249 struct rb_node *node; 250 251 nodes = kmalloc_array(nnodes, sizeof(*nodes), GFP_KERNEL); 252 if (!nodes) 253 return -ENOMEM; 254 255 printk(KERN_ALERT "rbtree testing"); 256 257 prandom_seed_state(&rnd, 3141592653589793238ULL); 258 init(); 259 260 time1 = get_cycles(); 261 262 for (i = 0; i < perf_loops; i++) { 263 for (j = 0; j < nnodes; j++) 264 insert(nodes + j, &root); 265 for (j = 0; j < nnodes; j++) 266 erase(nodes + j, &root); 267 } 268 269 time2 = get_cycles(); 270 time = time2 - time1; 271 272 time = div_u64(time, perf_loops); 273 printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n", 274 (unsigned long long)time); 275 276 time1 = get_cycles(); 277 278 for (i = 0; i < perf_loops; i++) { 279 for (j = 0; j < nnodes; j++) 280 insert_cached(nodes + j, &root); 281 for (j = 0; j < nnodes; j++) 282 erase_cached(nodes + j, &root); 283 } 284 285 time2 = get_cycles(); 286 time = time2 - time1; 287 288 time = div_u64(time, perf_loops); 289 printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n", 290 (unsigned long long)time); 291 292 for (i = 0; i < nnodes; i++) 293 insert(nodes + i, &root); 294 295 time1 = get_cycles(); 296 297 for (i = 0; i < perf_loops; i++) { 298 for (node = rb_first(&root.rb_root); node; node = rb_next(node)) 299 ; 300 } 301 302 time2 = get_cycles(); 303 time = time2 - time1; 304 305 time = div_u64(time, perf_loops); 306 printk(" -> test 3 (latency of inorder traversal): %llu cycles\n", 307 (unsigned long long)time); 308 309 time1 = get_cycles(); 310 311 for (i = 0; i < perf_loops; i++) 312 node = rb_first(&root.rb_root); 313 314 time2 = get_cycles(); 315 time = time2 - time1; 316 317 time = div_u64(time, perf_loops); 318 printk(" -> test 4 (latency to fetch first node)\n"); 319 printk(" non-cached: %llu cycles\n", (unsigned long long)time); 320 321 time1 = get_cycles(); 322 323 for (i = 0; i < perf_loops; i++) 324 node = rb_first_cached(&root); 325 326 time2 = get_cycles(); 327 time = time2 - time1; 328 329 time = div_u64(time, perf_loops); 330 printk(" cached: %llu cycles\n", (unsigned long long)time); 331 332 for (i = 0; i < nnodes; i++) 333 erase(nodes + i, &root); 334 335 /* run checks */ 336 for (i = 0; i < check_loops; i++) { 337 init(); 338 for (j = 0; j < nnodes; j++) { 339 check(j); 340 insert(nodes + j, &root); 341 } 342 for (j = 0; j < nnodes; j++) { 343 check(nnodes - j); 344 erase(nodes + j, &root); 345 } 346 check(0); 347 } 348 349 printk(KERN_ALERT "augmented rbtree testing"); 350 351 init(); 352 353 time1 = get_cycles(); 354 355 for (i = 0; i < perf_loops; i++) { 356 for (j = 0; j < nnodes; j++) 357 insert_augmented(nodes + j, &root); 358 for (j = 0; j < nnodes; j++) 359 erase_augmented(nodes + j, &root); 360 } 361 362 time2 = get_cycles(); 363 time = time2 - time1; 364 365 time = div_u64(time, perf_loops); 366 printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n", (unsigned long long)time); 367 368 time1 = get_cycles(); 369 370 for (i = 0; i < perf_loops; i++) { 371 for (j = 0; j < nnodes; j++) 372 insert_augmented_cached(nodes + j, &root); 373 for (j = 0; j < nnodes; j++) 374 erase_augmented_cached(nodes + j, &root); 375 } 376 377 time2 = get_cycles(); 378 time = time2 - time1; 379 380 time = div_u64(time, perf_loops); 381 printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n", (unsigned long long)time); 382 383 for (i = 0; i < check_loops; i++) { 384 init(); 385 for (j = 0; j < nnodes; j++) { 386 check_augmented(j); 387 insert_augmented(nodes + j, &root); 388 } 389 for (j = 0; j < nnodes; j++) { 390 check_augmented(nnodes - j); 391 erase_augmented(nodes + j, &root); 392 } 393 check_augmented(0); 394 } 395 396 kfree(nodes); 397 398 return -EAGAIN; /* Fail will directly unload the module */ 399 } 400 401 static void __exit rbtree_test_exit(void) 402 { 403 printk(KERN_ALERT "test exit\n"); 404 } 405 406 module_init(rbtree_test_init) 407 module_exit(rbtree_test_exit) 408 409 MODULE_LICENSE("GPL"); 410 MODULE_AUTHOR("Michel Lespinasse"); 411 MODULE_DESCRIPTION("Red Black Tree test"); 412