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-rw-r--r--lib/rbtree.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/lib/rbtree.c b/lib/rbtree.c
index d102d9d2ffaa..e7cce12f404f 100644
--- a/lib/rbtree.c
+++ b/lib/rbtree.c
@@ -105,16 +105,25 @@ __rb_insert(struct rb_node *node, struct rb_root *root,
while (true) {
/*
- * Loop invariant: node is red
- *
- * If there is a black parent, we are done.
- * Otherwise, take some corrective action as we don't
- * want a red root or two consecutive red nodes.
+ * Loop invariant: node is red.
*/
- if (!parent) {
+ if (unlikely(!parent)) {
+ /*
+ * The inserted node is root. Either this is the
+ * first node, or we recursed at Case 1 below and
+ * are no longer violating 4).
+ */
rb_set_parent_color(node, NULL, RB_BLACK);
break;
- } else if (rb_is_black(parent))
+ }
+
+ /*
+ * If there is a black parent, we are done.
+ * Otherwise, take some corrective action as,
+ * per 4), we don't want a red root or two
+ * consecutive red nodes.
+ */
+ if(rb_is_black(parent))
break;
gparent = rb_red_parent(parent);