xref: /openbmc/linux/lib/interval_tree_test.c (revision bc5aa3a0)
1 #include <linux/module.h>
2 #include <linux/interval_tree.h>
3 #include <linux/random.h>
4 #include <asm/timex.h>
5 
6 #define NODES        100
7 #define PERF_LOOPS   100000
8 #define SEARCHES     100
9 #define SEARCH_LOOPS 10000
10 
11 static struct rb_root root = RB_ROOT;
12 static struct interval_tree_node nodes[NODES];
13 static u32 queries[SEARCHES];
14 
15 static struct rnd_state rnd;
16 
17 static inline unsigned long
18 search(unsigned long query, struct rb_root *root)
19 {
20 	struct interval_tree_node *node;
21 	unsigned long results = 0;
22 
23 	for (node = interval_tree_iter_first(root, query, query); node;
24 	     node = interval_tree_iter_next(node, query, query))
25 		results++;
26 	return results;
27 }
28 
29 static void init(void)
30 {
31 	int i;
32 	for (i = 0; i < NODES; i++) {
33 		u32 a = prandom_u32_state(&rnd);
34 		u32 b = prandom_u32_state(&rnd);
35 		if (a <= b) {
36 			nodes[i].start = a;
37 			nodes[i].last = b;
38 		} else {
39 			nodes[i].start = b;
40 			nodes[i].last = a;
41 		}
42 	}
43 	for (i = 0; i < SEARCHES; i++)
44 		queries[i] = prandom_u32_state(&rnd);
45 }
46 
47 static int interval_tree_test_init(void)
48 {
49 	int i, j;
50 	unsigned long results;
51 	cycles_t time1, time2, time;
52 
53 	printk(KERN_ALERT "interval tree insert/remove");
54 
55 	prandom_seed_state(&rnd, 3141592653589793238ULL);
56 	init();
57 
58 	time1 = get_cycles();
59 
60 	for (i = 0; i < PERF_LOOPS; i++) {
61 		for (j = 0; j < NODES; j++)
62 			interval_tree_insert(nodes + j, &root);
63 		for (j = 0; j < NODES; j++)
64 			interval_tree_remove(nodes + j, &root);
65 	}
66 
67 	time2 = get_cycles();
68 	time = time2 - time1;
69 
70 	time = div_u64(time, PERF_LOOPS);
71 	printk(" -> %llu cycles\n", (unsigned long long)time);
72 
73 	printk(KERN_ALERT "interval tree search");
74 
75 	for (j = 0; j < NODES; j++)
76 		interval_tree_insert(nodes + j, &root);
77 
78 	time1 = get_cycles();
79 
80 	results = 0;
81 	for (i = 0; i < SEARCH_LOOPS; i++)
82 		for (j = 0; j < SEARCHES; j++)
83 			results += search(queries[j], &root);
84 
85 	time2 = get_cycles();
86 	time = time2 - time1;
87 
88 	time = div_u64(time, SEARCH_LOOPS);
89 	results = div_u64(results, SEARCH_LOOPS);
90 	printk(" -> %llu cycles (%lu results)\n",
91 	       (unsigned long long)time, results);
92 
93 	return -EAGAIN; /* Fail will directly unload the module */
94 }
95 
96 static void interval_tree_test_exit(void)
97 {
98 	printk(KERN_ALERT "test exit\n");
99 }
100 
101 module_init(interval_tree_test_init)
102 module_exit(interval_tree_test_exit)
103 
104 MODULE_LICENSE("GPL");
105 MODULE_AUTHOR("Michel Lespinasse");
106 MODULE_DESCRIPTION("Interval Tree test");
107