The patch titled
Subject: maple_tree: mtree_range_walk() clean up
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-mtree_range_walk-clean-up.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-mtree_range_walk-clean-up.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Subject: maple_tree: mtree_range_walk() clean up
Date: Wed, 1 Nov 2023 13:16:29 -0400
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.
Link: https://lkml.kernel.org/r/20231101171629.3612299-13-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)
--- a/lib/maple_tree.c~maple_tree-mtree_range_walk-clean-up
+++ a/lib/maple_tree.c
@@ -2806,32 +2806,29 @@ static inline void *mtree_range_walk(str
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);
_
Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are
maple_tree-remove-unnecessary-default-labels-from-switch-statements.patch
maple_tree-make-mas_erase-more-robust.patch
maple_tree-move-debug-check-to-__mas_set_range.patch
maple_tree-add-end-of-node-tracking-to-the-maple-state.patch
maple_tree-use-cached-node-end-in-mas_next.patch
maple_tree-use-cached-node-end-in-mas_destroy.patch
maple_tree-clean-up-inlines-for-some-functions.patch
maple_tree-separate-ma_state-node-from-status.patch
maple_tree-separate-ma_state-node-from-status-fix-1.patch
maple_tree-separate-ma_state-node-from-status-fix-2.patch
maple_tree-remove-mas_searchable.patch
maple_tree-use-maple-state-end-for-write-operations.patch
maple_tree-dont-find-node-end-in-mtree_lookup_walk.patch
maple_tree-mtree_range_walk-clean-up.patch
