From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Subject: radix-tree: remove a use of root->height from delete_node
If radix_tree_shrink returns whether it managed to shrink, then
__radix_tree_delete_node doesn't ned to query the tree to find out whether
it did any work or not.
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Cc: Kirill Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxxx>
Cc: Neil Brown <neilb@xxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/radix-tree.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff -puN lib/radix-tree.c~radix-tree-remove-a-use-of-root-height-from-delete_node lib/radix-tree.c
--- a/lib/radix-tree.c~radix-tree-remove-a-use-of-root-height-from-delete_node
+++ a/lib/radix-tree.c
@@ -1415,8 +1415,10 @@ unsigned long radix_tree_locate_item(str
* radix_tree_shrink - shrink height of a radix tree to minimal
* @root radix tree root
*/
-static inline void radix_tree_shrink(struct radix_tree_root *root)
+static inline bool radix_tree_shrink(struct radix_tree_root *root)
{
+ bool shrunk = false;
+
/* try to shrink tree height */
while (root->height > 0) {
struct radix_tree_node *to_free = root->rnode;
@@ -1476,7 +1478,10 @@ static inline void radix_tree_shrink(str
to_free->slots[0] = RADIX_TREE_RETRY;
radix_tree_node_free(to_free);
+ shrunk = true;
}
+
+ return shrunk;
}
/**
@@ -1499,11 +1504,8 @@ bool __radix_tree_delete_node(struct rad
struct radix_tree_node *parent;
if (node->count) {
- if (node == indirect_to_ptr(root->rnode)) {
- radix_tree_shrink(root);
- if (root->height == 0)
- deleted = true;
- }
+ if (node == indirect_to_ptr(root->rnode))
+ deleted |= radix_tree_shrink(root);
return deleted;
}
_
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