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#include <linux/module.h>
#include <linux/rbtree.h>
#include <linux/random.h>
#include <asm/timex.h>
#define NODES 100
#define PERF_LOOPS 100000
#define CHECK_LOOPS 100
struct test_node {
struct rb_node rb;
u32 key;
};
static struct rb_root root = RB_ROOT;
static struct test_node nodes[NODES];
static struct rnd_state rnd;
static void insert(struct test_node *node, struct rb_root *root)
{
struct rb_node **new = &root->rb_node, *parent = NULL;
while (*new) {
parent = *new;
if (node->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);
}
static inline void erase(struct test_node *node, struct rb_root *root)
{
rb_erase(&node->rb, root);
}
static void init(void)
{
int i;
for (i = 0; i < NODES; i++)
nodes[i].key = prandom32(&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(int nr_nodes)
{
struct rb_node *rb;
int count = 0;
int blacks;
u32 prev_key = 0;
for (rb = rb_first(&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);
}
static int rbtree_test_init(void)
{
int i, j;
cycles_t time1, time2, time;
printk(KERN_ALERT "rbtree testing");
prandom32_seed(&rnd, 3141592653589793238);
init();
time1 = get_cycles();
for (i = 0; i < PERF_LOOPS; i++) {
for (j = 0; j < NODES; j++)
insert(nodes + j, &root);
for (j = 0; j < NODES; j++)
erase(nodes + j, &root);
}
time2 = get_cycles();
time = time2 - time1;
time = div_u64(time, PERF_LOOPS);
printk(" -> %llu cycles\n", (unsigned long long)time);
for (i = 0; i < CHECK_LOOPS; i++) {
init();
for (j = 0; j < NODES; j++) {
check(j);
insert(nodes + j, &root);
}
for (j = 0; j < NODES; j++) {
check(NODES - j);
erase(nodes + j, &root);
}
check(0);
}
return -EAGAIN; /* Fail will directly unload the module */
}
static void 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");
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