mtree_range_walk() needed to be updated to avoid checking if there was a
pivot value. On closer examination, the code could avoid setting min or
max in certain scenarios. The commit removes the extra check for
pivot[offset] before setting max and only sets max when necessary. It
also only sets min if it is necessary by checking offset 0 prior to the
loop (as it has always done).
The commit also drops a dead node check since the end of the node will
return the array size when the last slot is occupied (by a potential
reuse in a dead node). The data will be discarded later if the node is
marked dead.
Benchmarking these changes results in an increase in performance of
5.45% using the BENCH_WALK in the maple tree test code.
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
lib/maple_tree.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index a91adaf17306..56cc8278260f 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2796,32 +2796,29 @@ static inline void *mtree_range_walk(struct ma_state *mas)
min = mas->min;
max = mas->max;
do {
- offset = 0;
last = next;
node = mte_to_node(next);
type = mte_node_type(next);
pivots = ma_pivots(node, type);
end = ma_data_end(node, type, pivots, max);
- if (unlikely(ma_dead_node(node)))
- goto dead_node;
-
- if (pivots[offset] >= mas->index) {
- prev_max = max;
- prev_min = min;
- max = pivots[offset];
+ prev_min = min;
+ prev_max = max;
+ if (pivots[0] >= mas->index) {
+ offset = 0;
+ max = pivots[0];
goto next;
}
- do {
+ offset = 1;
+ while (offset < end) {
+ if (pivots[offset] >= mas->index) {
+ max = pivots[offset];
+ break;
+ }
offset++;
- } while ((offset < end) && (pivots[offset] < mas->index));
+ }
- prev_min = min;
min = pivots[offset - 1] + 1;
- prev_max = max;
- if (likely(offset < end && pivots[offset]))
- max = pivots[offset];
-
next:
slots = ma_slots(node, type);
next = mt_slot(mas->tree, slots, offset);
--
2.40.1
