diff options
Diffstat (limited to 'kernel/lib/rbtree_test.c')
| -rw-r--r-- | kernel/lib/rbtree_test.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/kernel/lib/rbtree_test.c b/kernel/lib/rbtree_test.c new file mode 100644 index 000000000..8b3c9dc88 --- /dev/null +++ b/kernel/lib/rbtree_test.c @@ -0,0 +1,258 @@ +#include <linux/module.h> +#include <linux/rbtree_augmented.h> +#include <linux/random.h> +#include <asm/timex.h> + +#define NODES 100 +#define PERF_LOOPS 100000 +#define CHECK_LOOPS 100 + +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 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; + 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); +} + +static inline void erase(struct test_node *node, struct rb_root *root) +{ + rb_erase(&node->rb, root); +} + +static inline u32 augment_recompute(struct test_node *node) +{ + u32 max = node->val, child_augmented; + if (node->rb.rb_left) { + child_augmented = rb_entry(node->rb.rb_left, struct test_node, + rb)->augmented; + if (max < child_augmented) + max = child_augmented; + } + if (node->rb.rb_right) { + child_augmented = rb_entry(node->rb.rb_right, struct test_node, + rb)->augmented; + if (max < child_augmented) + max = child_augmented; + } + return max; +} + +RB_DECLARE_CALLBACKS(static, augment_callbacks, struct test_node, rb, + u32, augmented, augment_recompute) + +static void insert_augmented(struct test_node *node, struct rb_root *root) +{ + struct rb_node **new = &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, &augment_callbacks); +} + +static void erase_augmented(struct test_node *node, struct rb_root *root) +{ + rb_erase_augmented(&node->rb, root, &augment_callbacks); +} + +static void init(void) +{ + int i; + for (i = 0; i < NODES; 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) + 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; 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; 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))) - 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; rb = rb_next(rb)) { + struct test_node *node = rb_entry(rb, struct test_node, rb); + WARN_ON_ONCE(node->augmented != augment_recompute(node)); + } +} + +static int __init rbtree_test_init(void) +{ + int i, j; + cycles_t time1, time2, time; + + 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 < 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); + } + + printk(KERN_ALERT "augmented rbtree testing"); + + init(); + + time1 = get_cycles(); + + for (i = 0; i < PERF_LOOPS; i++) { + for (j = 0; j < NODES; j++) + insert_augmented(nodes + j, &root); + for (j = 0; j < NODES; j++) + erase_augmented(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_augmented(j); + insert_augmented(nodes + j, &root); + } + for (j = 0; j < NODES; j++) { + check_augmented(NODES - j); + erase_augmented(nodes + j, &root); + } + check_augmented(0); + } + + 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"); |