xref: /openbmc/linux/lib/interval_tree_test.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/module.h>
3 #include <linux/moduleparam.h>
4 #include <linux/interval_tree.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 interval tree");
15 __param(int, perf_loops, 1000, "Number of iterations modifying the tree");
16 
17 __param(int, nsearches, 100, "Number of searches to the interval tree");
18 __param(int, search_loops, 1000, "Number of iterations searching the tree");
19 __param(bool, search_all, false, "Searches will iterate all nodes in the tree");
20 
21 __param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
22 
23 static struct rb_root_cached root = RB_ROOT_CACHED;
24 static struct interval_tree_node *nodes = NULL;
25 static u32 *queries = NULL;
26 
27 static struct rnd_state rnd;
28 
29 static inline unsigned long
30 search(struct rb_root_cached *root, unsigned long start, unsigned long last)
31 {
32 	struct interval_tree_node *node;
33 	unsigned long results = 0;
34 
35 	for (node = interval_tree_iter_first(root, start, last); node;
36 	     node = interval_tree_iter_next(node, start, last))
37 		results++;
38 	return results;
39 }
40 
41 static void init(void)
42 {
43 	int i;
44 
45 	for (i = 0; i < nnodes; i++) {
46 		u32 b = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
47 		u32 a = (prandom_u32_state(&rnd) >> 4) % b;
48 
49 		nodes[i].start = a;
50 		nodes[i].last = b;
51 	}
52 
53 	/*
54 	 * Limit the search scope to what the user defined.
55 	 * Otherwise we are merely measuring empty walks,
56 	 * which is pointless.
57 	 */
58 	for (i = 0; i < nsearches; i++)
59 		queries[i] = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
60 }
61 
62 static int interval_tree_test_init(void)
63 {
64 	int i, j;
65 	unsigned long results;
66 	cycles_t time1, time2, time;
67 
68 	nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
69 			      GFP_KERNEL);
70 	if (!nodes)
71 		return -ENOMEM;
72 
73 	queries = kmalloc_array(nsearches, sizeof(int), GFP_KERNEL);
74 	if (!queries) {
75 		kfree(nodes);
76 		return -ENOMEM;
77 	}
78 
79 	printk(KERN_ALERT "interval tree insert/remove");
80 
81 	prandom_seed_state(&rnd, 3141592653589793238ULL);
82 	init();
83 
84 	time1 = get_cycles();
85 
86 	for (i = 0; i < perf_loops; i++) {
87 		for (j = 0; j < nnodes; j++)
88 			interval_tree_insert(nodes + j, &root);
89 		for (j = 0; j < nnodes; j++)
90 			interval_tree_remove(nodes + j, &root);
91 	}
92 
93 	time2 = get_cycles();
94 	time = time2 - time1;
95 
96 	time = div_u64(time, perf_loops);
97 	printk(" -> %llu cycles\n", (unsigned long long)time);
98 
99 	printk(KERN_ALERT "interval tree search");
100 
101 	for (j = 0; j < nnodes; j++)
102 		interval_tree_insert(nodes + j, &root);
103 
104 	time1 = get_cycles();
105 
106 	results = 0;
107 	for (i = 0; i < search_loops; i++)
108 		for (j = 0; j < nsearches; j++) {
109 			unsigned long start = search_all ? 0 : queries[j];
110 			unsigned long last = search_all ? max_endpoint : queries[j];
111 
112 			results += search(&root, start, last);
113 		}
114 
115 	time2 = get_cycles();
116 	time = time2 - time1;
117 
118 	time = div_u64(time, search_loops);
119 	results = div_u64(results, search_loops);
120 	printk(" -> %llu cycles (%lu results)\n",
121 	       (unsigned long long)time, results);
122 
123 	kfree(queries);
124 	kfree(nodes);
125 
126 	return -EAGAIN; /* Fail will directly unload the module */
127 }
128 
129 static void interval_tree_test_exit(void)
130 {
131 	printk(KERN_ALERT "test exit\n");
132 }
133 
134 module_init(interval_tree_test_init)
135 module_exit(interval_tree_test_exit)
136 
137 MODULE_LICENSE("GPL");
138 MODULE_AUTHOR("Michel Lespinasse");
139 MODULE_DESCRIPTION("Interval Tree test");
140