lib/rbtree_test.c: support rb_root_cached
We can work with a single rb_root_cached root to test both cached and
non-cached rbtrees. In addition, also add a test to measure latencies
between rb_first and its fast counterpart.
Link: http://lkml.kernel.org/r/20170719014603.19029-7-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
index 967999ff..191a238 100644
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -23,14 +23,14 @@
u32 augmented;
};
-static struct rb_root root = RB_ROOT;
+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 *root)
+static void insert(struct test_node *node, struct rb_root_cached *root)
{
- struct rb_node **new = &root->rb_node, *parent = NULL;
+ struct rb_node **new = &root->rb_root.rb_node, *parent = NULL;
u32 key = node->key;
while (*new) {
@@ -42,14 +42,40 @@
}
rb_link_node(&node->rb, parent, new);
- rb_insert_color(&node->rb, root);
+ rb_insert_color(&node->rb, &root->rb_root);
}
-static inline void erase(struct test_node *node, struct rb_root *root)
+static void insert_cached(struct test_node *node, struct rb_root_cached *root)
{
- rb_erase(&node->rb, 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);
+}
+
+
static inline u32 augment_recompute(struct test_node *node)
{
u32 max = node->val, child_augmented;
@@ -71,9 +97,10 @@
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)
+static void insert_augmented(struct test_node *node,
+ struct rb_root_cached *root)
{
- struct rb_node **new = &root->rb_node, *rb_parent = NULL;
+ struct rb_node **new = &root->rb_root.rb_node, *rb_parent = NULL;
u32 key = node->key;
u32 val = node->val;
struct test_node *parent;
@@ -91,12 +118,47 @@
node->augmented = val;
rb_link_node(&node->rb, rb_parent, new);
- rb_insert_augmented(&node->rb, root, &augment_callbacks);
+ rb_insert_augmented(&node->rb, &root->rb_root, &augment_callbacks);
}
-static void erase_augmented(struct test_node *node, struct rb_root *root)
+static void insert_augmented_cached(struct test_node *node,
+ struct rb_root_cached *root)
{
- rb_erase_augmented(&node->rb, root, &augment_callbacks);
+ 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)
@@ -125,7 +187,7 @@
{
struct test_node *cur, *n;
int count = 0;
- rbtree_postorder_for_each_entry_safe(cur, n, &root, rb)
+ rbtree_postorder_for_each_entry_safe(cur, n, &root.rb_root, rb)
count++;
WARN_ON_ONCE(count != nr_nodes);
@@ -135,7 +197,7 @@
{
struct rb_node *rb;
int count = 0;
- for (rb = rb_first_postorder(&root); rb; rb = rb_next_postorder(rb))
+ for (rb = rb_first_postorder(&root.rb_root); rb; rb = rb_next_postorder(rb))
count++;
WARN_ON_ONCE(count != nr_nodes);
@@ -147,7 +209,7 @@
int count = 0, blacks = 0;
u32 prev_key = 0;
- for (rb = rb_first(&root); rb; rb = rb_next(rb)) {
+ 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) &&
@@ -162,7 +224,7 @@
}
WARN_ON_ONCE(count != nr_nodes);
- WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root))) - 1);
+ WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root.rb_root))) - 1);
check_postorder(nr_nodes);
check_postorder_foreach(nr_nodes);
@@ -173,7 +235,7 @@
struct rb_node *rb;
check(nr_nodes);
- for (rb = rb_first(&root); rb; rb = rb_next(rb)) {
+ 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->augmented != augment_recompute(node));
}
@@ -207,7 +269,24 @@
time = time2 - time1;
time = div_u64(time, perf_loops);
- printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n", (unsigned long long)time);
+ 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);
@@ -215,7 +294,7 @@
time1 = get_cycles();
for (i = 0; i < perf_loops; i++) {
- for (node = rb_first(&root); node; node = rb_next(node))
+ for (node = rb_first(&root.rb_root); node; node = rb_next(node))
;
}
@@ -223,7 +302,31 @@
time = time2 - time1;
time = div_u64(time, perf_loops);
- printk(" -> test 2 (latency of inorder traversal): %llu cycles\n", (unsigned long long)time);
+ 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);
@@ -261,6 +364,21 @@
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++) {