// SPDX-License-Identifier: GPL-2.0-only#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 longsearch(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_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;	} 	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");