From 04faec084e83e9c0d46cf6331d4764a3cdca7027 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Date: Tue, 1 Dec 2020 16:36:30 -0500
Subject: [PATCH] maple_tree: optimize mas_rev_awalk and mas_awalk a bit

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 lib/maple_tree.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 19f87c067991..b50b7cb60927 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3956,7 +3956,7 @@ static inline bool _mas_awalk(struct ma_state *mas, unsigned long size)
 {
 	enum maple_type type = mte_node_type(mas->node);
 	unsigned long pivot, min, gap = 0;
-	unsigned char offset = 0;
+	unsigned char count, offset = 0;
 	unsigned long *gaps = NULL, *pivots = ma_pivots(mas_mn(mas), type);
 	void **slots = ma_slots(mas_mn(mas), type);
 	bool found = false;
@@ -3971,8 +3971,9 @@ static inline bool _mas_awalk(struct ma_state *mas, unsigned long size)
 		gaps = ma_gaps(mte_to_node(mas->node), type);
 	}
 
+	count = mt_slots[type];
 	min = mas_safe_min(mas, pivots, offset);
-	for (; offset < mt_slots[type]; offset++) {
+	for (; offset < count; offset++) {
 		pivot = _mas_safe_pivot(mas, pivots, offset, type);
 		if (offset && !pivot)
 			break;
@@ -4179,27 +4180,35 @@ void mas_rev_awalk(struct ma_state *mas, unsigned long size)
 /* Skip this slot in the parent. */
 static inline bool mas_skip_node(struct ma_state *mas)
 {
-	unsigned char slot;
+	unsigned char slot, slot_count;
+	unsigned long *pivots;
+	enum maple_type mt;
 
+	mt = mte_node_type(mas->node);
+	slot_count = mt_slots[mt] - 1;
 	do {
 		if (mte_is_root(mas->node)) {
 			slot = mas->offset;
-			if (slot > mt_slot_count(mas->node) - 1) {
+			if (slot > slot_count) {
 				mas_set_err(mas, -EBUSY);
 				return false;
 			}
 		} else {
 			slot = mte_parent_slot(mas->node);
 			mas_ascend(mas);
+			mt = mte_node_type(mas->node);
+			slot_count = mt_slots[mt] - 1;
 		}
-	} while (slot > mt_slot_count(mas->node) - 1);
+	} while (slot > slot_count);
 
 	mas->offset = ++slot;
+	pivots = ma_pivots(mas_mn(mas), mt);
 	if (slot > 0)
-		mas->min = mte_pivot(mas->node, slot - 1) + 1;
+		mas->min = pivots[slot - 1] + 1;
+
+	if (slot <= slot_count)
+		mas->max = pivots[slot];
 
-	if (slot < mt_pivot_count(mas->node))
-		mas->max = mte_pivot(mas->node, slot);
 	return true;
 }
 
-- 
2.50.1