Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / lib / rbtree_test.c
diff --git a/kernel/lib/rbtree_test.c b/kernel/lib/rbtree_test.c
new file mode 100644 (file)
index 0000000..8b3c9dc
--- /dev/null
@@ -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");