Re: [PATCH] Documentation: Update augmented rbtree documentation

From: Peter Zijlstra
Date: Mon May 16 2011 - 06:11:20 EST

On Mon, 2011-05-16 at 12:56 +0300, Sasha Levin wrote:
> Current documentation referred to the old method
> of handling augmented trees. Update documentation
> to correspond with the changes done in commit
> b945d6b2554d550fe95caadc61e521c0ad71fb9c.
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx>

Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>

> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: David Woodhouse <David.Woodhouse@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
> ---
> Documentation/rbtree.txt | 23 ++++++++++++++---------
> 1 files changed, 14 insertions(+), 9 deletions(-)
> diff --git a/Documentation/rbtree.txt b/Documentation/rbtree.txt
> index 19f8278..b847598 100644
> --- a/Documentation/rbtree.txt
> +++ b/Documentation/rbtree.txt
> @@ -196,15 +196,20 @@ Support for Augmented rbtrees
> Augmented rbtree is an rbtree with "some" additional data stored in each node.
> This data can be used to augment some new functionality to rbtree.
> Augmented rbtree is an optional feature built on top of basic rbtree
> -infrastructure. rbtree user who wants this feature will have an augment
> -callback function in rb_root initialized.
> -
> -This callback function will be called from rbtree core routines whenever
> -a node has a change in one or both of its children. It is the responsibility
> -of the callback function to recalculate the additional data that is in the
> -rb node using new children information. Note that if this new additional
> -data affects the parent node's additional data, then callback function has
> -to handle it and do the recursive updates.
> +infrastructure. rbtree user who wants this feature will have to call the
> +augmentation functions with the user provided augmentation callback
> +when inserting and erasing nodes.
> +
> +On insertion, The user must call rb_augment_insert() once the new node is in
> +place. This will cause the augmentation function callback to be called for
> +each node between the new node and the root which have been affected by the
> +insertion.
> +
> +When erasing a node, The user must call rb_augment_erase_begin() first to
> +retrieve the deepest node on the rebalance path. Then, After erasing the
> +original node, the user must call rb_augment_erase_end() with the deepest
> +node found earlier. This will cause the augmentation function to be called
> +for each affected node between the deepest node and the root.
> Interval tree is an example of augmented rb tree. Reference -

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at