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