The patch titled
Subject: maple_tree: don't find node end in mtree_lookup_walk()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-dont-find-node-end-in-mtree_lookup_walk.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-dont-find-node-end-in-mtree_lookup_walk.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: don't find node end in mtree_lookup_walk()
Date: Wed, 1 Nov 2023 13:16:28 -0400
Since the pivot being set is now reliable, the optimized loop no longer
needs to find the node end. The redundant check for a dead node can also
be avoided as there is no danger of using the wrong pivot since the
results will be thrown out in the case of a dead node by the later check.
This patch also adds a benchmark test for the function to the maple tree
test framework. The benchmark shows an average increase performance of
5.98% over 3 runs with this commit.
Link: https://lkml.kernel.org/r/20231101171629.3612299-12-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 | 12 +++---------
lib/test_maple_tree.c | 21 +++++++++++++++++++++
2 files changed, 24 insertions(+), 9 deletions(-)
--- a/lib/maple_tree.c~maple_tree-dont-find-node-end-in-mtree_lookup_walk
+++ a/lib/maple_tree.c
@@ -3742,23 +3742,17 @@ static inline void *mtree_lookup_walk(st
enum maple_type type;
void __rcu **slots;
unsigned char end;
- unsigned long max;
next = mas->node;
- max = ULONG_MAX;
do {
- offset = 0;
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;
+ end = mt_pivots[type];
+ offset = 0;
do {
- if (pivots[offset] >= mas->index) {
- max = pivots[offset];
+ if (pivots[offset] >= mas->index)
break;
- }
} while (++offset < end);
slots = ma_slots(node, type);
--- a/lib/test_maple_tree.c~maple_tree-dont-find-node-end-in-mtree_lookup_walk
+++ a/lib/test_maple_tree.c
@@ -43,6 +43,7 @@ atomic_t maple_tree_tests_passed;
/* #define BENCH_NODE_STORE */
/* #define BENCH_AWALK */
/* #define BENCH_WALK */
+/* #define BENCH_LOAD */
/* #define BENCH_MT_FOR_EACH */
/* #define BENCH_FORK */
/* #define BENCH_MAS_FOR_EACH */
@@ -1754,6 +1755,19 @@ static noinline void __init bench_walk(s
}
#endif
+#if defined(BENCH_LOAD)
+static noinline void __init bench_load(struct maple_tree *mt)
+{
+ int i, max = 2500, count = 550000000;
+
+ for (i = 0; i < max; i += 10)
+ mtree_store_range(mt, i, i + 5, xa_mk_value(i), GFP_KERNEL);
+
+ for (i = 0; i < count; i++)
+ mtree_load(mt, 1470);
+}
+#endif
+
#if defined(BENCH_MT_FOR_EACH)
static noinline void __init bench_mt_for_each(struct maple_tree *mt)
{
@@ -3618,6 +3632,13 @@ static int __init maple_tree_seed(void)
mtree_destroy(&tree);
goto skip;
#endif
+#if defined(BENCH_LOAD)
+#define BENCH
+ mt_init_flags(&tree, MT_FLAGS_ALLOC_RANGE);
+ bench_load(&tree);
+ mtree_destroy(&tree);
+ goto skip;
+#endif
#if defined(BENCH_FORK)
#define BENCH
bench_forking();
_
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
