diff options
Diffstat (limited to '')
-rw-r--r-- | lib/rbtree_test.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c new file mode 100644 index 000000000..41ae3c757 --- /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"); |