lib/rbtree_test.c: add (inorder) traversal test
[linux-block.git] / lib / rbtree_test.c
CommitLineData
910a742d 1#include <linux/module.h>
223f8911 2#include <linux/moduleparam.h>
9c079add 3#include <linux/rbtree_augmented.h>
910a742d 4#include <linux/random.h>
223f8911 5#include <linux/slab.h>
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6#include <asm/timex.h>
7
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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, 100000, "Number of iterations modifying the rb-tree");
15__param(int, check_loops, 100, "Number of iterations modifying and verifying the rb-tree");
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16
17struct test_node {
910a742d 18 u32 key;
dbf128cb 19 struct rb_node rb;
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20
21 /* following fields used for testing augmented rbtree functionality */
22 u32 val;
23 u32 augmented;
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24};
25
26static struct rb_root root = RB_ROOT;
223f8911 27static struct test_node *nodes = NULL;
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28
29static struct rnd_state rnd;
30
31static void insert(struct test_node *node, struct rb_root *root)
32{
33 struct rb_node **new = &root->rb_node, *parent = NULL;
dadf9353 34 u32 key = node->key;
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35
36 while (*new) {
37 parent = *new;
dadf9353 38 if (key < rb_entry(parent, struct test_node, rb)->key)
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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);
46}
47
48static inline void erase(struct test_node *node, struct rb_root *root)
49{
50 rb_erase(&node->rb, root);
51}
52
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53static inline u32 augment_recompute(struct test_node *node)
54{
55 u32 max = node->val, child_augmented;
56 if (node->rb.rb_left) {
57 child_augmented = rb_entry(node->rb.rb_left, struct test_node,
58 rb)->augmented;
59 if (max < child_augmented)
60 max = child_augmented;
61 }
62 if (node->rb.rb_right) {
63 child_augmented = rb_entry(node->rb.rb_right, struct test_node,
64 rb)->augmented;
65 if (max < child_augmented)
66 max = child_augmented;
67 }
68 return max;
69}
70
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71RB_DECLARE_CALLBACKS(static, augment_callbacks, struct test_node, rb,
72 u32, augmented, augment_recompute)
14b94af0 73
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74static void insert_augmented(struct test_node *node, struct rb_root *root)
75{
14b94af0 76 struct rb_node **new = &root->rb_node, *rb_parent = NULL;
dadf9353 77 u32 key = node->key;
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78 u32 val = node->val;
79 struct test_node *parent;
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80
81 while (*new) {
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82 rb_parent = *new;
83 parent = rb_entry(rb_parent, struct test_node, rb);
84 if (parent->augmented < val)
85 parent->augmented = val;
86 if (key < parent->key)
87 new = &parent->rb.rb_left;
dadf9353 88 else
14b94af0 89 new = &parent->rb.rb_right;
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90 }
91
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92 node->augmented = val;
93 rb_link_node(&node->rb, rb_parent, new);
94 rb_insert_augmented(&node->rb, root, &augment_callbacks);
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95}
96
97static void erase_augmented(struct test_node *node, struct rb_root *root)
98{
14b94af0 99 rb_erase_augmented(&node->rb, root, &augment_callbacks);
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100}
101
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102static void init(void)
103{
104 int i;
223f8911 105 for (i = 0; i < nnodes; i++) {
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106 nodes[i].key = prandom_u32_state(&rnd);
107 nodes[i].val = prandom_u32_state(&rnd);
dadf9353 108 }
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109}
110
111static bool is_red(struct rb_node *rb)
112{
113 return !(rb->__rb_parent_color & 1);
114}
115
116static int black_path_count(struct rb_node *rb)
117{
118 int count;
119 for (count = 0; rb; rb = rb_parent(rb))
120 count += !is_red(rb);
121 return count;
122}
123
964fe94d
CS
124static void check_postorder_foreach(int nr_nodes)
125{
126 struct test_node *cur, *n;
127 int count = 0;
128 rbtree_postorder_for_each_entry_safe(cur, n, &root, rb)
129 count++;
130
131 WARN_ON_ONCE(count != nr_nodes);
132}
133
a791a62f
CS
134static void check_postorder(int nr_nodes)
135{
136 struct rb_node *rb;
137 int count = 0;
138 for (rb = rb_first_postorder(&root); rb; rb = rb_next_postorder(rb))
139 count++;
140
141 WARN_ON_ONCE(count != nr_nodes);
142}
143
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144static void check(int nr_nodes)
145{
146 struct rb_node *rb;
4130f0ef 147 int count = 0, blacks = 0;
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148 u32 prev_key = 0;
149
150 for (rb = rb_first(&root); rb; rb = rb_next(rb)) {
151 struct test_node *node = rb_entry(rb, struct test_node, rb);
152 WARN_ON_ONCE(node->key < prev_key);
153 WARN_ON_ONCE(is_red(rb) &&
154 (!rb_parent(rb) || is_red(rb_parent(rb))));
155 if (!count)
156 blacks = black_path_count(rb);
157 else
158 WARN_ON_ONCE((!rb->rb_left || !rb->rb_right) &&
159 blacks != black_path_count(rb));
160 prev_key = node->key;
161 count++;
162 }
4130f0ef 163
910a742d 164 WARN_ON_ONCE(count != nr_nodes);
4130f0ef 165 WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root))) - 1);
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166
167 check_postorder(nr_nodes);
964fe94d 168 check_postorder_foreach(nr_nodes);
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169}
170
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171static void check_augmented(int nr_nodes)
172{
173 struct rb_node *rb;
174
175 check(nr_nodes);
176 for (rb = rb_first(&root); rb; rb = rb_next(rb)) {
177 struct test_node *node = rb_entry(rb, struct test_node, rb);
178 WARN_ON_ONCE(node->augmented != augment_recompute(node));
179 }
180}
181
c75aaa8e 182static int __init rbtree_test_init(void)
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183{
184 int i, j;
185 cycles_t time1, time2, time;
977bd8d5 186 struct rb_node *node;
910a742d 187
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188 nodes = kmalloc(nnodes * sizeof(*nodes), GFP_KERNEL);
189 if (!nodes)
190 return -ENOMEM;
191
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192 printk(KERN_ALERT "rbtree testing");
193
496f2f93 194 prandom_seed_state(&rnd, 3141592653589793238ULL);
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195 init();
196
197 time1 = get_cycles();
198
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DB
199 for (i = 0; i < perf_loops; i++) {
200 for (j = 0; j < nnodes; j++)
910a742d 201 insert(nodes + j, &root);
223f8911 202 for (j = 0; j < nnodes; j++)
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203 erase(nodes + j, &root);
204 }
205
206 time2 = get_cycles();
207 time = time2 - time1;
208
223f8911 209 time = div_u64(time, perf_loops);
977bd8d5 210 printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n", (unsigned long long)time);
910a742d 211
977bd8d5
DB
212 for (i = 0; i < nnodes; i++)
213 insert(nodes + i, &root);
214
215 time1 = get_cycles();
216
217 for (i = 0; i < perf_loops; i++) {
218 for (node = rb_first(&root); node; node = rb_next(node))
219 ;
220 }
221
222 time2 = get_cycles();
223 time = time2 - time1;
224
225 time = div_u64(time, perf_loops);
226 printk(" -> test 2 (latency of inorder traversal): %llu cycles\n", (unsigned long long)time);
227
228 for (i = 0; i < nnodes; i++)
229 erase(nodes + i, &root);
230
231 /* run checks */
223f8911 232 for (i = 0; i < check_loops; i++) {
910a742d 233 init();
223f8911 234 for (j = 0; j < nnodes; j++) {
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235 check(j);
236 insert(nodes + j, &root);
237 }
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238 for (j = 0; j < nnodes; j++) {
239 check(nnodes - j);
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240 erase(nodes + j, &root);
241 }
242 check(0);
243 }
244
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245 printk(KERN_ALERT "augmented rbtree testing");
246
247 init();
248
249 time1 = get_cycles();
250
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DB
251 for (i = 0; i < perf_loops; i++) {
252 for (j = 0; j < nnodes; j++)
dadf9353 253 insert_augmented(nodes + j, &root);
223f8911 254 for (j = 0; j < nnodes; j++)
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255 erase_augmented(nodes + j, &root);
256 }
257
258 time2 = get_cycles();
259 time = time2 - time1;
260
223f8911 261 time = div_u64(time, perf_loops);
977bd8d5 262 printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n", (unsigned long long)time);
dadf9353 263
223f8911 264 for (i = 0; i < check_loops; i++) {
dadf9353 265 init();
223f8911 266 for (j = 0; j < nnodes; j++) {
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267 check_augmented(j);
268 insert_augmented(nodes + j, &root);
269 }
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270 for (j = 0; j < nnodes; j++) {
271 check_augmented(nnodes - j);
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272 erase_augmented(nodes + j, &root);
273 }
274 check_augmented(0);
275 }
276
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277 kfree(nodes);
278
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279 return -EAGAIN; /* Fail will directly unload the module */
280}
281
c75aaa8e 282static void __exit rbtree_test_exit(void)
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283{
284 printk(KERN_ALERT "test exit\n");
285}
286
287module_init(rbtree_test_init)
288module_exit(rbtree_test_exit)
289
290MODULE_LICENSE("GPL");
291MODULE_AUTHOR("Michel Lespinasse");
292MODULE_DESCRIPTION("Red Black Tree test");