This allows support for using the vacant height to calculate the worst
case number of nodes needed for wr_rebalance operation.
mas_spanning_rebalance() was seen to perform unnecessary node allocations.
We can reduce allocations by breaking early during the rebalancing loop
once we realize that we have ascended to a common ancestor.
Suggested-by: Liam Howlett <liam.howlett@xxxxxxxxxx>
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
lib/maple_tree.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f14d70c171c2..59c5c3f8db30 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2904,11 +2904,21 @@ static void mas_spanning_rebalance(struct ma_state *mas,
mast_combine_cp_right(mast);
mast->orig_l->last = mast->orig_l->max;
- if (mast_sufficient(mast))
- continue;
+ if (mast_sufficient(mast)) {
+ if (mast_overflow(mast))
+ continue;
+
+ if (mast->orig_l->node == mast->orig_r->node) {
+ /*
+ * The data in b_node should be stored in one
+ * node and in the tree
+ */
+ slot = mast->l->offset;
+ break;
+ }
- if (mast_overflow(mast))
continue;
+ }
/* May be a new root stored in mast->bn */
if (mas_is_root_limits(mast->orig_l))
--
2.43.0
