From bb3db4e3030b59e2f5324df5c0a3df5ddfcb1bdc Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@Oracle.com>
Date: Sun, 17 Feb 2019 17:01:21 -0500
Subject: [PATCH] maple_tree: Optimize _mas_walk

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---
 lib/maple_tree.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 3f0aeee47063..b2f7cbddf7e1 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1284,16 +1284,18 @@ static inline bool _mas_walk(struct ma_state *mas)
 	enum maple_type type;
 	struct maple_node *next;
 	unsigned long pivot_cnt, pivot, max, min, i;
+	bool ret = true;
 
 	mas->node = mas_start(mas);
+	min = mas->min;
+	max = mas->max;
 
 	while (true) {
 		type = mt_node_type(mas->node);
 		pivot_cnt = mt_pivots[type];
-		min = mas->min;
-		max = mas->max;
 
-		if (pivot_cnt) {
+		switch (type) {
+		default:
 			pivot = 0;
 			for (i = 0; i < pivot_cnt; i++) {
 				pivot = _ma_get_pivot(mas->node, i, type);
@@ -1309,30 +1311,34 @@ static inline bool _mas_walk(struct ma_state *mas)
 				min = pivot;
 			}
 
-			if (i == pivot_cnt - 1) {
-				if (mas->index > pivot)
+			if ((i == pivot_cnt - 1) && (mas->index > pivot))
 					i++;
-			}
-		} else {
+
+			if (type < maple_range_16) // Leaf.
+				goto done;
+			break;
+
+		case maple_dense:
 			// Linear node.
 			i = mas->index - mas->min;
 			if (mas->min)
 				i--;
+			goto done;
+			break;
 		}
 
-		ma_set_slot(mas, i);
-		if (type < maple_range_16) // Leaf.
-			return true;
-
 		next = _ma_get_rcu_slot(mas->node, i, type);
 		if (!next) // Not found.
-			return type < maple_range_16;
+			goto done;
 
 		// Traverse.
 		mas->max = max;
 		mas->min = min;
 		mas->node = next;
 	}
+done:
+	ma_set_slot(mas, i);
+	return ret;
 }
 
 static inline void ma_insert(struct ma_state *mas, void *entry)
-- 
2.50.1