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// 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");