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: &node->rb, parent, rb_link: 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: &node->rb, parent, rb_link: new); |
66 | rb_insert_color_cached(node: &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: &node->rb, root); |
77 | } |
78 | |
79 | |
80 | #define NODE_VAL(node) ((node)->val) |
81 | |
82 | RB_DECLARE_CALLBACKS_MAX(static, augment_callbacks, |
83 | struct test_node, rb, u32, augmented, NODE_VAL) |
84 | |
85 | static void insert_augmented(struct test_node *node, |
86 | struct rb_root_cached *root) |
87 | { |
88 | struct rb_node **new = &root->rb_root.rb_node, *rb_parent = NULL; |
89 | u32 key = node->key; |
90 | u32 val = node->val; |
91 | struct test_node *parent; |
92 | |
93 | while (*new) { |
94 | rb_parent = *new; |
95 | parent = rb_entry(rb_parent, struct test_node, rb); |
96 | if (parent->augmented < val) |
97 | parent->augmented = val; |
98 | if (key < parent->key) |
99 | new = &parent->rb.rb_left; |
100 | else |
101 | new = &parent->rb.rb_right; |
102 | } |
103 | |
104 | node->augmented = val; |
105 | rb_link_node(node: &node->rb, parent: rb_parent, rb_link: new); |
106 | rb_insert_augmented(node: &node->rb, root: &root->rb_root, augment: &augment_callbacks); |
107 | } |
108 | |
109 | static void insert_augmented_cached(struct test_node *node, |
110 | struct rb_root_cached *root) |
111 | { |
112 | struct rb_node **new = &root->rb_root.rb_node, *rb_parent = NULL; |
113 | u32 key = node->key; |
114 | u32 val = node->val; |
115 | struct test_node *parent; |
116 | bool leftmost = true; |
117 | |
118 | while (*new) { |
119 | rb_parent = *new; |
120 | parent = rb_entry(rb_parent, struct test_node, rb); |
121 | if (parent->augmented < val) |
122 | parent->augmented = val; |
123 | if (key < parent->key) |
124 | new = &parent->rb.rb_left; |
125 | else { |
126 | new = &parent->rb.rb_right; |
127 | leftmost = false; |
128 | } |
129 | } |
130 | |
131 | node->augmented = val; |
132 | rb_link_node(node: &node->rb, parent: rb_parent, rb_link: new); |
133 | rb_insert_augmented_cached(node: &node->rb, root, |
134 | newleft: leftmost, augment: &augment_callbacks); |
135 | } |
136 | |
137 | |
138 | static void erase_augmented(struct test_node *node, struct rb_root_cached *root) |
139 | { |
140 | rb_erase_augmented(node: &node->rb, root: &root->rb_root, augment: &augment_callbacks); |
141 | } |
142 | |
143 | static void erase_augmented_cached(struct test_node *node, |
144 | struct rb_root_cached *root) |
145 | { |
146 | rb_erase_augmented_cached(node: &node->rb, root, augment: &augment_callbacks); |
147 | } |
148 | |
149 | static void init(void) |
150 | { |
151 | int i; |
152 | for (i = 0; i < nnodes; i++) { |
153 | nodes[i].key = prandom_u32_state(state: &rnd); |
154 | nodes[i].val = prandom_u32_state(state: &rnd); |
155 | } |
156 | } |
157 | |
158 | static bool is_red(struct rb_node *rb) |
159 | { |
160 | return !(rb->__rb_parent_color & 1); |
161 | } |
162 | |
163 | static int black_path_count(struct rb_node *rb) |
164 | { |
165 | int count; |
166 | for (count = 0; rb; rb = rb_parent(rb)) |
167 | count += !is_red(rb); |
168 | return count; |
169 | } |
170 | |
171 | static void check_postorder_foreach(int nr_nodes) |
172 | { |
173 | struct test_node *cur, *n; |
174 | int count = 0; |
175 | rbtree_postorder_for_each_entry_safe(cur, n, &root.rb_root, rb) |
176 | count++; |
177 | |
178 | WARN_ON_ONCE(count != nr_nodes); |
179 | } |
180 | |
181 | static void check_postorder(int nr_nodes) |
182 | { |
183 | struct rb_node *rb; |
184 | int count = 0; |
185 | for (rb = rb_first_postorder(&root.rb_root); rb; rb = rb_next_postorder(rb)) |
186 | count++; |
187 | |
188 | WARN_ON_ONCE(count != nr_nodes); |
189 | } |
190 | |
191 | static void check(int nr_nodes) |
192 | { |
193 | struct rb_node *rb; |
194 | int count = 0, blacks = 0; |
195 | u32 prev_key = 0; |
196 | |
197 | for (rb = rb_first(&root.rb_root); rb; rb = rb_next(rb)) { |
198 | struct test_node *node = rb_entry(rb, struct test_node, rb); |
199 | WARN_ON_ONCE(node->key < prev_key); |
200 | WARN_ON_ONCE(is_red(rb) && |
201 | (!rb_parent(rb) || is_red(rb_parent(rb)))); |
202 | if (!count) |
203 | blacks = black_path_count(rb); |
204 | else |
205 | WARN_ON_ONCE((!rb->rb_left || !rb->rb_right) && |
206 | blacks != black_path_count(rb)); |
207 | prev_key = node->key; |
208 | count++; |
209 | } |
210 | |
211 | WARN_ON_ONCE(count != nr_nodes); |
212 | WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root.rb_root))) - 1); |
213 | |
214 | check_postorder(nr_nodes); |
215 | check_postorder_foreach(nr_nodes); |
216 | } |
217 | |
218 | static void check_augmented(int nr_nodes) |
219 | { |
220 | struct rb_node *rb; |
221 | |
222 | check(nr_nodes); |
223 | for (rb = rb_first(&root.rb_root); rb; rb = rb_next(rb)) { |
224 | struct test_node *node = rb_entry(rb, struct test_node, rb); |
225 | u32 subtree, max = node->val; |
226 | if (node->rb.rb_left) { |
227 | subtree = rb_entry(node->rb.rb_left, struct test_node, |
228 | rb)->augmented; |
229 | if (max < subtree) |
230 | max = subtree; |
231 | } |
232 | if (node->rb.rb_right) { |
233 | subtree = rb_entry(node->rb.rb_right, struct test_node, |
234 | rb)->augmented; |
235 | if (max < subtree) |
236 | max = subtree; |
237 | } |
238 | WARN_ON_ONCE(node->augmented != max); |
239 | } |
240 | } |
241 | |
242 | static int __init rbtree_test_init(void) |
243 | { |
244 | int i, j; |
245 | cycles_t time1, time2, time; |
246 | struct rb_node *node; |
247 | |
248 | nodes = kmalloc_array(n: nnodes, size: sizeof(*nodes), GFP_KERNEL); |
249 | if (!nodes) |
250 | return -ENOMEM; |
251 | |
252 | printk(KERN_ALERT "rbtree testing" ); |
253 | |
254 | prandom_seed_state(state: &rnd, seed: 3141592653589793238ULL); |
255 | init(); |
256 | |
257 | time1 = get_cycles(); |
258 | |
259 | for (i = 0; i < perf_loops; i++) { |
260 | for (j = 0; j < nnodes; j++) |
261 | insert(node: nodes + j, root: &root); |
262 | for (j = 0; j < nnodes; j++) |
263 | erase(node: nodes + j, root: &root); |
264 | } |
265 | |
266 | time2 = get_cycles(); |
267 | time = time2 - time1; |
268 | |
269 | time = div_u64(dividend: time, divisor: perf_loops); |
270 | printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n" , |
271 | (unsigned long long)time); |
272 | |
273 | time1 = get_cycles(); |
274 | |
275 | for (i = 0; i < perf_loops; i++) { |
276 | for (j = 0; j < nnodes; j++) |
277 | insert_cached(node: nodes + j, root: &root); |
278 | for (j = 0; j < nnodes; j++) |
279 | erase_cached(node: nodes + j, root: &root); |
280 | } |
281 | |
282 | time2 = get_cycles(); |
283 | time = time2 - time1; |
284 | |
285 | time = div_u64(dividend: time, divisor: perf_loops); |
286 | printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n" , |
287 | (unsigned long long)time); |
288 | |
289 | for (i = 0; i < nnodes; i++) |
290 | insert(node: nodes + i, root: &root); |
291 | |
292 | time1 = get_cycles(); |
293 | |
294 | for (i = 0; i < perf_loops; i++) { |
295 | for (node = rb_first(&root.rb_root); node; node = rb_next(node)) |
296 | ; |
297 | } |
298 | |
299 | time2 = get_cycles(); |
300 | time = time2 - time1; |
301 | |
302 | time = div_u64(dividend: time, divisor: perf_loops); |
303 | printk(" -> test 3 (latency of inorder traversal): %llu cycles\n" , |
304 | (unsigned long long)time); |
305 | |
306 | time1 = get_cycles(); |
307 | |
308 | for (i = 0; i < perf_loops; i++) |
309 | node = rb_first(&root.rb_root); |
310 | |
311 | time2 = get_cycles(); |
312 | time = time2 - time1; |
313 | |
314 | time = div_u64(dividend: time, divisor: perf_loops); |
315 | printk(" -> test 4 (latency to fetch first node)\n" ); |
316 | printk(" non-cached: %llu cycles\n" , (unsigned long long)time); |
317 | |
318 | time1 = get_cycles(); |
319 | |
320 | for (i = 0; i < perf_loops; i++) |
321 | node = rb_first_cached(&root); |
322 | |
323 | time2 = get_cycles(); |
324 | time = time2 - time1; |
325 | |
326 | time = div_u64(dividend: time, divisor: perf_loops); |
327 | printk(" cached: %llu cycles\n" , (unsigned long long)time); |
328 | |
329 | for (i = 0; i < nnodes; i++) |
330 | erase(node: nodes + i, root: &root); |
331 | |
332 | /* run checks */ |
333 | for (i = 0; i < check_loops; i++) { |
334 | init(); |
335 | for (j = 0; j < nnodes; j++) { |
336 | check(nr_nodes: j); |
337 | insert(node: nodes + j, root: &root); |
338 | } |
339 | for (j = 0; j < nnodes; j++) { |
340 | check(nr_nodes: nnodes - j); |
341 | erase(node: nodes + j, root: &root); |
342 | } |
343 | check(nr_nodes: 0); |
344 | } |
345 | |
346 | printk(KERN_ALERT "augmented rbtree testing" ); |
347 | |
348 | init(); |
349 | |
350 | time1 = get_cycles(); |
351 | |
352 | for (i = 0; i < perf_loops; i++) { |
353 | for (j = 0; j < nnodes; j++) |
354 | insert_augmented(node: nodes + j, root: &root); |
355 | for (j = 0; j < nnodes; j++) |
356 | erase_augmented(node: nodes + j, root: &root); |
357 | } |
358 | |
359 | time2 = get_cycles(); |
360 | time = time2 - time1; |
361 | |
362 | time = div_u64(dividend: time, divisor: perf_loops); |
363 | printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n" , (unsigned long long)time); |
364 | |
365 | time1 = get_cycles(); |
366 | |
367 | for (i = 0; i < perf_loops; i++) { |
368 | for (j = 0; j < nnodes; j++) |
369 | insert_augmented_cached(node: nodes + j, root: &root); |
370 | for (j = 0; j < nnodes; j++) |
371 | erase_augmented_cached(node: nodes + j, root: &root); |
372 | } |
373 | |
374 | time2 = get_cycles(); |
375 | time = time2 - time1; |
376 | |
377 | time = div_u64(dividend: time, divisor: perf_loops); |
378 | printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n" , (unsigned long long)time); |
379 | |
380 | for (i = 0; i < check_loops; i++) { |
381 | init(); |
382 | for (j = 0; j < nnodes; j++) { |
383 | check_augmented(nr_nodes: j); |
384 | insert_augmented(node: nodes + j, root: &root); |
385 | } |
386 | for (j = 0; j < nnodes; j++) { |
387 | check_augmented(nr_nodes: nnodes - j); |
388 | erase_augmented(node: nodes + j, root: &root); |
389 | } |
390 | check_augmented(nr_nodes: 0); |
391 | } |
392 | |
393 | kfree(objp: nodes); |
394 | |
395 | return -EAGAIN; /* Fail will directly unload the module */ |
396 | } |
397 | |
398 | static void __exit rbtree_test_exit(void) |
399 | { |
400 | printk(KERN_ALERT "test exit\n" ); |
401 | } |
402 | |
403 | module_init(rbtree_test_init) |
404 | module_exit(rbtree_test_exit) |
405 | |
406 | MODULE_LICENSE("GPL" ); |
407 | MODULE_AUTHOR("Michel Lespinasse" ); |
408 | MODULE_DESCRIPTION("Red Black Tree test" ); |
409 | |