1 files changed, 408 insertions, 0 deletions
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
new file mode 100644
index 0000000000..41ae3c7570
--- /dev/null
+++ b/lib/rbtree_test.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/rbtree_augmented.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 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");
+
+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 __init rbtree_test_init(void)
+{
+	int i, j;
+	cycles_t time1, time2, time;
+	struct rb_node *node;
+
+	nodes = kmalloc_array(nnodes, sizeof(*nodes), GFP_KERNEL);
+	if (!nodes)
+		return -ENOMEM;
+
+	printk(KERN_ALERT "rbtree testing");
+
+	prandom_seed_state(&rnd, 3141592653589793238ULL);
+	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);
+	}
+
+	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);
+	}
+
+	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");