// SPDX-License-Identifier: GPL-2.0-only#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/rbtree_augmented.h>#include <linux/prandom.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 rb-tree");__param(int, perf_loops, 1000, "Number of iterations modifying the rb-tree");__param(int, check_loops, 100, "Number of iterations modifying and verifying the rb-tree");__param(ullong, seed, 3141592653589793238ULL, "Random seed"); struct test_node {	u32 key;	struct rb_node rb; 	/* following fields used for testing augmented rbtree functionality */	u32 val;	u32 augmented;}; static struct rb_root_cached root = RB_ROOT_CACHED;static struct test_node *nodes = NULL; static struct rnd_state rnd; static void insert(struct test_node *node, struct rb_root_cached *root){	struct rb_node **new = &root->rb_root.rb_node, *parent = NULL;	u32 key = node->key; 	while (*new) {		parent = *new;		if (key < rb_entry(parent, struct test_node, rb)->key)			new = &parent->rb_left;		else			new = &parent->rb_right;	} 	rb_link_node(&node->rb, parent, new);	rb_insert_color(&node->rb, &root->rb_root);} static void insert_cached(struct test_node *node, struct rb_root_cached *root){	struct rb_node **new = &root->rb_root.rb_node, *parent = NULL;	u32 key = node->key;	bool leftmost = true; 	while (*new) {		parent = *new;		if (key < rb_entry(parent, struct test_node, rb)->key)			new = &parent->rb_left;		else {			new = &parent->rb_right;			leftmost = false;		}	} 	rb_link_node(&node->rb, parent, new);	rb_insert_color_cached(&node->rb, root, leftmost);} static inline void erase(struct test_node *node, struct rb_root_cached *root){	rb_erase(&node->rb, &root->rb_root);} static inline void erase_cached(struct test_node *node, struct rb_root_cached *root){	rb_erase_cached(&node->rb, root);}  #define NODE_VAL(node) ((node)->val) RB_DECLARE_CALLBACKS_MAX(static, augment_callbacks,			 struct test_node, rb, u32, augmented, NODE_VAL) static void insert_augmented(struct test_node *node,			     struct rb_root_cached *root){	struct rb_node **new = &root->rb_root.rb_node, *rb_parent = NULL;	u32 key = node->key;	u32 val = node->val;	struct test_node *parent; 	while (*new) {		rb_parent = *new;		parent = rb_entry(rb_parent, struct test_node, rb);		if (parent->augmented < val)			parent->augmented = val;		if (key < parent->key)			new = &parent->rb.rb_left;		else			new = &parent->rb.rb_right;	} 	node->augmented = val;	rb_link_node(&node->rb, rb_parent, new);	rb_insert_augmented(&node->rb, &root->rb_root, &augment_callbacks);} static void insert_augmented_cached(struct test_node *node,				    struct rb_root_cached *root){	struct rb_node **new = &root->rb_root.rb_node, *rb_parent = NULL;	u32 key = node->key;	u32 val = node->val;	struct test_node *parent;	bool leftmost = true; 	while (*new) {		rb_parent = *new;		parent = rb_entry(rb_parent, struct test_node, rb);		if (parent->augmented < val)			parent->augmented = val;		if (key < parent->key)			new = &parent->rb.rb_left;		else {			new = &parent->rb.rb_right;			leftmost = false;		}	} 	node->augmented = val;	rb_link_node(&node->rb, rb_parent, new);	rb_insert_augmented_cached(&node->rb, root,				   leftmost, &augment_callbacks);}  static void erase_augmented(struct test_node *node, struct rb_root_cached *root){	rb_erase_augmented(&node->rb, &root->rb_root, &augment_callbacks);} static void erase_augmented_cached(struct test_node *node,				   struct rb_root_cached *root){	rb_erase_augmented_cached(&node->rb, root, &augment_callbacks);} static void init(void){	int i;	for (i = 0; i < nnodes; i++) {		nodes[i].key = prandom_u32_state(&rnd);		nodes[i].val = prandom_u32_state(&rnd);	}} static bool is_red(struct rb_node *rb){	return !(rb->__rb_parent_color & 1);} static int black_path_count(struct rb_node *rb){	int count;	for (count = 0; rb; rb = rb_parent(rb))		count += !is_red(rb);	return count;} static void check_postorder_foreach(int nr_nodes){	struct test_node *cur, *n;	int count = 0;	rbtree_postorder_for_each_entry_safe(cur, n, &root.rb_root, rb)		count++; 	WARN_ON_ONCE(count != nr_nodes);} static void check_postorder(int nr_nodes){	struct rb_node *rb;	int count = 0;	for (rb = rb_first_postorder(&root.rb_root); rb; rb = rb_next_postorder(rb))		count++; 	WARN_ON_ONCE(count != nr_nodes);} static void check(int nr_nodes){	struct rb_node *rb;	int count = 0, blacks = 0;	u32 prev_key = 0; 	for (rb = rb_first(&root.rb_root); rb; rb = rb_next(rb)) {		struct test_node *node = rb_entry(rb, struct test_node, rb);		WARN_ON_ONCE(node->key < prev_key);		WARN_ON_ONCE(is_red(rb) &&			     (!rb_parent(rb) || is_red(rb_parent(rb))));		if (!count)			blacks = black_path_count(rb);		else			WARN_ON_ONCE((!rb->rb_left || !rb->rb_right) &&				     blacks != black_path_count(rb));		prev_key = node->key;		count++;	} 	WARN_ON_ONCE(count != nr_nodes);	WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root.rb_root))) - 1); 	check_postorder(nr_nodes);	check_postorder_foreach(nr_nodes);} static void check_augmented(int nr_nodes){	struct rb_node *rb; 	check(nr_nodes);	for (rb = rb_first(&root.rb_root); rb; rb = rb_next(rb)) {		struct test_node *node = rb_entry(rb, struct test_node, rb);		u32 subtree, max = node->val;		if (node->rb.rb_left) {			subtree = rb_entry(node->rb.rb_left, struct test_node,					   rb)->augmented;			if (max < subtree)				max = subtree;		}		if (node->rb.rb_right) {			subtree = rb_entry(node->rb.rb_right, struct test_node,					   rb)->augmented;			if (max < subtree)				max = subtree;		}		WARN_ON_ONCE(node->augmented != max);	}} static int basic_check(void){	int i, j;	cycles_t time1, time2, time;	struct rb_node *node; 	printk(KERN_ALERT "rbtree testing"); 	init(); 	time1 = get_cycles(); 	for (i = 0; i < perf_loops; i++) {		for (j = 0; j < nnodes; j++)			insert(nodes + j, &root);		for (j = 0; j < nnodes; j++)			erase(nodes + j, &root);	} 	time2 = get_cycles();	time = time2 - time1; 	time = div_u64(time, perf_loops);	printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n",	       (unsigned long long)time); 	time1 = get_cycles(); 	for (i = 0; i < perf_loops; i++) {		for (j = 0; j < nnodes; j++)			insert_cached(nodes + j, &root);		for (j = 0; j < nnodes; j++)			erase_cached(nodes + j, &root);	} 	time2 = get_cycles();	time = time2 - time1; 	time = div_u64(time, perf_loops);	printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n",	       (unsigned long long)time); 	for (i = 0; i < nnodes; i++)		insert(nodes + i, &root); 	time1 = get_cycles(); 	for (i = 0; i < perf_loops; i++) {		for (node = rb_first(&root.rb_root); node; node = rb_next(node))			;	} 	time2 = get_cycles();	time = time2 - time1; 	time = div_u64(time, perf_loops);	printk(" -> test 3 (latency of inorder traversal): %llu cycles\n",	       (unsigned long long)time); 	time1 = get_cycles(); 	for (i = 0; i < perf_loops; i++)		node = rb_first(&root.rb_root); 	time2 = get_cycles();	time = time2 - time1; 	time = div_u64(time, perf_loops);	printk(" -> test 4 (latency to fetch first node)\n");	printk("        non-cached: %llu cycles\n", (unsigned long long)time); 	time1 = get_cycles(); 	for (i = 0; i < perf_loops; i++)		node = rb_first_cached(&root); 	time2 = get_cycles();	time = time2 - time1; 	time = div_u64(time, perf_loops);	printk("        cached: %llu cycles\n", (unsigned long long)time); 	for (i = 0; i < nnodes; i++)		erase(nodes + i, &root); 	/* run checks */	for (i = 0; i < check_loops; i++) {		init();		for (j = 0; j < nnodes; j++) {			check(j);			insert(nodes + j, &root);		}		for (j = 0; j < nnodes; j++) {			check(nnodes - j);			erase(nodes + j, &root);		}		check(0);	} 	return 0;} static int augmented_check(void){	int i, j;	cycles_t time1, time2, time; 	printk(KERN_ALERT "augmented rbtree testing"); 	init(); 	time1 = get_cycles(); 	for (i = 0; i < perf_loops; i++) {		for (j = 0; j < nnodes; j++)			insert_augmented(nodes + j, &root);		for (j = 0; j < nnodes; j++)			erase_augmented(nodes + j, &root);	} 	time2 = get_cycles();	time = time2 - time1; 	time = div_u64(time, perf_loops);	printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n", (unsigned long long)time); 	time1 = get_cycles(); 	for (i = 0; i < perf_loops; i++) {		for (j = 0; j < nnodes; j++)			insert_augmented_cached(nodes + j, &root);		for (j = 0; j < nnodes; j++)			erase_augmented_cached(nodes + j, &root);	} 	time2 = get_cycles();	time = time2 - time1; 	time = div_u64(time, perf_loops);	printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n", (unsigned long long)time); 	for (i = 0; i < check_loops; i++) {		init();		for (j = 0; j < nnodes; j++) {			check_augmented(j);			insert_augmented(nodes + j, &root);		}		for (j = 0; j < nnodes; j++) {			check_augmented(nnodes - j);			erase_augmented(nodes + j, &root);		}		check_augmented(0);	} 	return 0;} static int __init rbtree_test_init(void){	nodes = kmalloc_objs(*nodes, nnodes);	if (!nodes)		return -ENOMEM; 	prandom_seed_state(&rnd, seed); 	basic_check();	augmented_check(); 	kfree(nodes); 	return -EAGAIN; /* Fail will directly unload the module */} static void __exit rbtree_test_exit(void){	printk(KERN_ALERT "test exit\n");} module_init(rbtree_test_init)module_exit(rbtree_test_exit) MODULE_LICENSE("GPL");MODULE_AUTHOR("Michel Lespinasse");MODULE_DESCRIPTION("Red Black Tree test");