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// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/interval_tree.h>
#include <linux/prandom.h>
#include <linux/slab.h>
#include <asm/timex.h>
#include <linux/bitmap.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");
__param(ullong, seed, 3141592653589793238ULL, "Random seed");
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 basic_check(void)
{
int i, j;
cycles_t time1, time2, time;
printk(KERN_ALERT "interval tree insert/remove");
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);
return 0;
}
static int search_check(void)
{
int i, j;
unsigned long results;
cycles_t time1, time2, time;
printk(KERN_ALERT "interval tree search");
init();
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);
for (j = 0; j < nnodes; j++)
interval_tree_remove(nodes + j, &root);
return 0;
}
static int intersection_range_check(void)
{
int i, j, k;
unsigned long start, last;
struct interval_tree_node *node;
unsigned long *intxn1;
unsigned long *intxn2;
printk(KERN_ALERT "interval tree iteration\n");
intxn1 = bitmap_alloc(nnodes, GFP_KERNEL);
if (!intxn1) {
WARN_ON_ONCE("Failed to allocate intxn1\n");
return -ENOMEM;
}
intxn2 = bitmap_alloc(nnodes, GFP_KERNEL);
if (!intxn2) {
WARN_ON_ONCE("Failed to allocate intxn2\n");
bitmap_free(intxn1);
return -ENOMEM;
}
for (i = 0; i < search_loops; i++) {
/* Initialize interval tree for each round */
init();
for (j = 0; j < nnodes; j++)
interval_tree_insert(nodes + j, &root);
/* Let's try nsearches different ranges */
for (k = 0; k < nsearches; k++) {
/* Try whole range once */
if (!k) {
start = 0UL;
last = ULONG_MAX;
} else {
last = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
start = (prandom_u32_state(&rnd) >> 4) % last;
}
/* Walk nodes to mark intersection nodes */
bitmap_zero(intxn1, nnodes);
for (j = 0; j < nnodes; j++) {
node = nodes + j;
if (start <= node->last && last >= node->start)
bitmap_set(intxn1, j, 1);
}
/* Iterate tree to clear intersection nodes */
bitmap_zero(intxn2, nnodes);
for (node = interval_tree_iter_first(&root, start, last); node;
node = interval_tree_iter_next(node, start, last))
bitmap_set(intxn2, node - nodes, 1);
WARN_ON_ONCE(!bitmap_equal(intxn1, intxn2, nnodes));
}
for (j = 0; j < nnodes; j++)
interval_tree_remove(nodes + j, &root);
}
bitmap_free(intxn1);
bitmap_free(intxn2);
return 0;
}
static int interval_tree_test_init(void)
{
nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
GFP_KERNEL);
if (!nodes)
return -ENOMEM;
queries = kmalloc_array(nsearches, sizeof(int), GFP_KERNEL);
if (!queries) {
kfree(nodes);
return -ENOMEM;
}
prandom_seed_state(&rnd, seed);
basic_check();
search_check();
intersection_range_check();
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");
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