// 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 <linux/printk.h>#include <asm/timex.h>#include <linux/bitmap.h>#include <linux/maple_tree.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 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 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;} #ifdef CONFIG_INTERVAL_TREE_SPAN_ITER/* * Helper function to get span of current position from maple tree point of * view. */static void mas_cur_span(struct ma_state *mas, struct interval_tree_span_iter *state){	unsigned long cur_start;	unsigned long cur_last;	int is_hole; 	if (mas->status == ma_overflow)		return; 	/* walk to current position */	state->is_hole = mas_walk(mas) ? 0 : 1; 	cur_start = mas->index < state->first_index ?			state->first_index : mas->index; 	/* whether we have followers */	do { 		cur_last = mas->last > state->last_index ?				state->last_index : mas->last; 		is_hole = mas_next_range(mas, state->last_index) ? 0 : 1; 	} while (mas->status != ma_overflow && is_hole == state->is_hole); 	if (state->is_hole) {		state->start_hole = cur_start;		state->last_hole = cur_last;	} else {		state->start_used = cur_start;		state->last_used = cur_last;	} 	/* advance position for next round */	if (mas->status != ma_overflow)		mas_set(mas, cur_last + 1);} static int span_iteration_check(void){	int i, j, k;	unsigned long start, last;	struct interval_tree_span_iter span, mas_span; 	DEFINE_MTREE(tree); 	MA_STATE(mas, &tree, 0, 0); 	printk(KERN_ALERT "interval tree span iteration\n"); 	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); 		/* Put all the range into maple tree */		mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);		mt_set_in_rcu(&tree); 		for (j = 0; j < nnodes; j++)			WARN_ON_ONCE(mtree_store_range(&tree, nodes[j].start,					nodes[j].last, nodes + j, GFP_KERNEL)); 		/* 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;			} 			mas_span.first_index = start;			mas_span.last_index = last;			mas_span.is_hole = -1;			mas_set(&mas, start); 			interval_tree_for_each_span(&span, &root, start, last) {				mas_cur_span(&mas, &mas_span); 				WARN_ON_ONCE(span.is_hole != mas_span.is_hole); 				if (span.is_hole) {					WARN_ON_ONCE(span.start_hole != mas_span.start_hole);					WARN_ON_ONCE(span.last_hole != mas_span.last_hole);				} else {					WARN_ON_ONCE(span.start_used != mas_span.start_used);					WARN_ON_ONCE(span.last_used != mas_span.last_used);				}			} 		} 		WARN_ON_ONCE(mas.status != ma_overflow); 		/* Cleanup maple tree for each round */		mtree_destroy(&tree);		/* Cleanup interval tree for each round */		for (j = 0; j < nnodes; j++)			interval_tree_remove(nodes + j, &root);	}	return 0;}#elsestatic inline int span_iteration_check(void) {return 0; }#endif static int interval_tree_test_init(void){	if (nnodes <= 0) {		pr_warn("nnodes must be positive\n");		return -EINVAL;	}	if (nsearches <= 0) {		pr_warn("nsearches must be positive\n");		return -EINVAL;	}	if (perf_loops <= 0) {		pr_warn("perf_loops must be positive\n");		return -EINVAL;	}	if (search_loops <= 0) {		pr_warn("search_loops must be positive\n");		return -EINVAL;	}	if (max_endpoint < 2) {		pr_warn("max_endpoint must be at least 2\n");		return -EINVAL;	} 	nodes = kmalloc_objs(struct interval_tree_node, nnodes);	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();	span_iteration_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");