summaryrefslogtreecommitdiffstats
path: root/lib/interval_tree_test.c
blob: 835242e74aaa3372957e46291c08bdc16ec59882 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/interval_tree.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <asm/timex.h>

#define __param(type, name, init, msg)		\
	static type name = init;		\
	module_param(name, type, 0444);		\
	MODULE_PARM_DESC(name, msg);

__param(int, nnodes, 100, "Number of nodes in the interval tree");
__param(int, perf_loops, 1000, "Number of iterations modifying the tree");

__param(int, nsearches, 100, "Number of searches to the interval tree");
__param(int, search_loops, 1000, "Number of iterations searching the tree");
__param(bool, search_all, false, "Searches will iterate all nodes in the tree");

__param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");

static struct rb_root_cached root = RB_ROOT_CACHED;
static struct interval_tree_node *nodes = NULL;
static u32 *queries = NULL;

static struct rnd_state rnd;

static inline unsigned long
search(struct rb_root_cached *root, unsigned long start, unsigned long last)
{
	struct interval_tree_node *node;
	unsigned long results = 0;

	for (node = interval_tree_iter_first(root, start, last); node;
	     node = interval_tree_iter_next(node, start, last))
		results++;
	return results;
}

static void init(void)
{
	int i;

	for (i = 0; i < nnodes; i++) {
		u32 b = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
		u32 a = (prandom_u32_state(&rnd) >> 4) % b;

		nodes[i].start = a;
		nodes[i].last = b;
	}

	/*
	 * Limit the search scope to what the user defined.
	 * Otherwise we are merely measuring empty walks,
	 * which is pointless.
	 */
	for (i = 0; i < nsearches; i++)
		queries[i] = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
}

static int interval_tree_test_init(void)
{
	int i, j;
	unsigned long results;
	cycles_t time1, time2, time;

	nodes = kmalloc(nnodes * sizeof(struct interval_tree_node), GFP_KERNEL);
	if (!nodes)
		return -ENOMEM;

	queries = kmalloc(nsearches * sizeof(int), GFP_KERNEL);
	if (!queries) {
		kfree(nodes);
		return -ENOMEM;
	}

	printk(KERN_ALERT "interval tree insert/remove");

	prandom_seed_state(&rnd, 3141592653589793238ULL);
	init();

	time1 = get_cycles();

	for (i = 0; i < perf_loops; i++) {
		for (j = 0; j < nnodes; j++)
			interval_tree_insert(nodes + j, &root);
		for (j = 0; j < nnodes; j++)
			interval_tree_remove(nodes + j, &root);
	}

	time2 = get_cycles();
	time = time2 - time1;

	time = div_u64(time, perf_loops);
	printk(" -> %llu cycles\n", (unsigned long long)time);

	printk(KERN_ALERT "interval tree search");

	for (j = 0; j < nnodes; j++)
		interval_tree_insert(nodes + j, &root);

	time1 = get_cycles();

	results = 0;
	for (i = 0; i < search_loops; i++)
		for (j = 0; j < nsearches; j++) {
			unsigned long start = search_all ? 0 : queries[j];
			unsigned long last = search_all ? max_endpoint : queries[j];

			results += search(&root, start, last);
		}

	time2 = get_cycles();
	time = time2 - time1;

	time = div_u64(time, search_loops);
	results = div_u64(results, search_loops);
	printk(" -> %llu cycles (%lu results)\n",
	       (unsigned long long)time, results);

	kfree(queries);
	kfree(nodes);

	return -EAGAIN; /* Fail will directly unload the module */
}

static void interval_tree_test_exit(void)
{
	printk(KERN_ALERT "test exit\n");
}

module_init(interval_tree_test_init)
module_exit(interval_tree_test_exit)

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michel Lespinasse");
MODULE_DESCRIPTION("Interval Tree test");