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
23static struct rb_root_cached root = RB_ROOT_CACHED;
24static struct interval_tree_node *nodes = NULL;
25static u32 *queries = NULL;
26
27static struct rnd_state rnd;
28
29static inline unsigned long
30search(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
41static 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
62static 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
129static void interval_tree_test_exit(void)
130{
131	printk(KERN_ALERT "test exit\n");
132}
133
134module_init(interval_tree_test_init)
135module_exit(interval_tree_test_exit)
136
137MODULE_LICENSE("GPL");
138MODULE_AUTHOR("Michel Lespinasse");
139MODULE_DESCRIPTION("Interval Tree test");
140