On Mon, May 29, 2017 at 07:09:36PM -0700, Davidlohr Bueso wrote:
> diff --git a/include/linux/rbtree_augmented.h
> b/include/linux/rbtree_augmented.h
> index 9702b6e183bc..b84ee26c19d9 100644
> --- a/include/linux/rbtree_augmented.h
> +++ b/include/linux/rbtree_augmented.h
> @@ -41,7 +41,9 @@ struct rb_augment_callbacks {
> void (*rotate)(struct rb_node *old, struct rb_node *new);
> };
>
> -extern void __rb_insert_augmented(struct rb_node *node, struct rb_root *root,
> +extern void __rb_insert_augmented(struct rb_node *node,
> + struct rb_root *root,
> + bool newleft, struct rb_node **leftmost,
> void (*augment_rotate)(struct rb_node *old, struct rb_node *new));
> /*
> * Fixup the rbtree and update the augmented information when rebalancing.
> @@ -150,6 +161,7 @@ extern void __rb_erase_color(struct rb_node *parent,
> struct rb_root *root,
>
> static __always_inline struct rb_node *
> __rb_erase_augmented(struct rb_node *node, struct rb_root *root,
> + bool cached, struct rb_node **leftmost,
> const struct rb_augment_callbacks *augment)
> {
> struct rb_node *child = node->rb_right;
> @@ -157,6 +169,9 @@ __rb_erase_augmented(struct rb_node *node, struct rb_root
> *root,
> struct rb_node *parent, *rebalance;
> unsigned long pc;
>
> + if (cached && node == *leftmost)
> + *leftmost = rb_next(node);
> +
> if (!tmp) {
> /*
> * Case 1: node to erase has no more than 1 child (easy!)
Why do we have @cached ? Wouldn't simply testing @leftmost for NULL not
do the same?
