xref: /openbmc/linux/lib/interval_tree_test.c (revision e2c75e76)
1 #include <linux/module.h>
2 #include <linux/moduleparam.h>
3 #include <linux/interval_tree.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 interval tree");
14 __param(int, perf_loops, 1000, "Number of iterations modifying the tree");
15 
16 __param(int, nsearches, 100, "Number of searches to the interval tree");
17 __param(int, search_loops, 1000, "Number of iterations searching the tree");
18 __param(bool, search_all, false, "Searches will iterate all nodes in the tree");
19 
20 __param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
21 
22 static struct rb_root_cached root = RB_ROOT_CACHED;
23 static struct interval_tree_node *nodes = NULL;
24 static u32 *queries = NULL;
25 
26 static struct rnd_state rnd;
27 
28 static inline unsigned long
29 search(struct rb_root_cached *root, unsigned long start, unsigned long last)
30 {
31 	struct interval_tree_node *node;
32 	unsigned long results = 0;
33 
34 	for (node = interval_tree_iter_first(root, start, last); node;
35 	     node = interval_tree_iter_next(node, start, last))
36 		results++;
37 	return results;
38 }
39 
40 static void init(void)
41 {
42 	int i;
43 
44 	for (i = 0; i < nnodes; i++) {
45 		u32 b = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
46 		u32 a = (prandom_u32_state(&rnd) >> 4) % b;
47 
48 		nodes[i].start = a;
49 		nodes[i].last = b;
50 	}
51 
52 	/*
53 	 * Limit the search scope to what the user defined.
54 	 * Otherwise we are merely measuring empty walks,
55 	 * which is pointless.
56 	 */
57 	for (i = 0; i < nsearches; i++)
58 		queries[i] = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
59 }
60 
61 static int interval_tree_test_init(void)
62 {
63 	int i, j;
64 	unsigned long results;
65 	cycles_t time1, time2, time;
66 
67 	nodes = kmalloc(nnodes * sizeof(struct interval_tree_node), GFP_KERNEL);
68 	if (!nodes)
69 		return -ENOMEM;
70 
71 	queries = kmalloc(nsearches * sizeof(int), GFP_KERNEL);
72 	if (!queries) {
73 		kfree(nodes);
74 		return -ENOMEM;
75 	}
76 
77 	printk(KERN_ALERT "interval tree insert/remove");
78 
79 	prandom_seed_state(&rnd, 3141592653589793238ULL);
80 	init();
81 
82 	time1 = get_cycles();
83 
84 	for (i = 0; i < perf_loops; i++) {
85 		for (j = 0; j < nnodes; j++)
86 			interval_tree_insert(nodes + j, &root);
87 		for (j = 0; j < nnodes; j++)
88 			interval_tree_remove(nodes + j, &root);
89 	}
90 
91 	time2 = get_cycles();
92 	time = time2 - time1;
93 
94 	time = div_u64(time, perf_loops);
95 	printk(" -> %llu cycles\n", (unsigned long long)time);
96 
97 	printk(KERN_ALERT "interval tree search");
98 
99 	for (j = 0; j < nnodes; j++)
100 		interval_tree_insert(nodes + j, &root);
101 
102 	time1 = get_cycles();
103 
104 	results = 0;
105 	for (i = 0; i < search_loops; i++)
106 		for (j = 0; j < nsearches; j++) {
107 			unsigned long start = search_all ? 0 : queries[j];
108 			unsigned long last = search_all ? max_endpoint : queries[j];
109 
110 			results += search(&root, start, last);
111 		}
112 
113 	time2 = get_cycles();
114 	time = time2 - time1;
115 
116 	time = div_u64(time, search_loops);
117 	results = div_u64(results, search_loops);
118 	printk(" -> %llu cycles (%lu results)\n",
119 	       (unsigned long long)time, results);
120 
121 	kfree(queries);
122 	kfree(nodes);
123 
124 	return -EAGAIN; /* Fail will directly unload the module */
125 }
126 
127 static void interval_tree_test_exit(void)
128 {
129 	printk(KERN_ALERT "test exit\n");
130 }
131 
132 module_init(interval_tree_test_init)
133 module_exit(interval_tree_test_exit)
134 
135 MODULE_LICENSE("GPL");
136 MODULE_AUTHOR("Michel Lespinasse");
137 MODULE_DESCRIPTION("Interval Tree test");
138