v4.19.13 snapshot.
diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
new file mode 100644
index 0000000..b7055b2
--- /dev/null
+++ b/lib/rbtree_test.c
@@ -0,0 +1,410 @@
+#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);
+}
+
+
+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_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);
+ WARN_ON_ONCE(node->augmented != augment_recompute(node));
+ }
+}
+
+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");