From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Mon, 16 Nov 2020 19:42:02 +0000 (-0500)
Subject: maple_tree: More efficient rev_awalk and mas_next()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b77a6fece949fc698b792fb9c6e80030dc38af79;p=users%2Fjedix%2Flinux-maple.git

maple_tree: More efficient rev_awalk and mas_next()

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 02113349de6e..02505ede97db 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3721,17 +3721,17 @@ static inline void *__mas_next(struct ma_state *mas, unsigned long limit,
 	void *entry = NULL;
 	struct maple_enode *prev_node;
 	unsigned long index = mas->index;
+	enum maple_type mt = mte_node_type(mas->node);
 
 	mas->offset++;
 retry:
 	*range_start = mas->last + 1;
 
 	while (!mas_is_none(mas)) {
-
-		if (mas->offset >= mt_slot_count(mas->node))
+		if (mas->offset >= mt_slots[mt])
 			goto next_node;
 
-		if (!mte_is_leaf(mas->node) || !mas->offset) {
+		if (!ma_is_leaf(mt) || !mas->offset) {
 			prev_node = mas->node;
 			*range_start = mas_first_entry(mas, limit);
 			if (mas_is_none(mas)) {
@@ -3749,6 +3749,7 @@ retry:
 next_node:
 		mas_next_node(mas, limit);
 		mas->offset = 0;
+		mt = mte_node_type(mas->node);
 	}
 
 	if (mas_is_none(mas))
@@ -3826,13 +3827,11 @@ EXPORT_SYMBOL_GPL(mas_prev);
 
 bool _mas_rev_awalk(struct ma_state *mas, unsigned long size)
 {
-	struct maple_node *node = mas_mn(mas);
 	enum maple_type type = mte_node_type(mas->node);
+	struct maple_node *node = mas_mn(mas);
 	unsigned long *pivots, *gaps;
 	void **slots;
-	unsigned char offset = mas->offset;
-	unsigned long max;
-	unsigned long gap, min;
+	unsigned long gap, max, min;
 
 	if (ma_is_dense(type)) { // dense nodes.
 		mas->offset = (unsigned char)(mas->index - mas->min);
@@ -3844,10 +3843,10 @@ bool _mas_rev_awalk(struct ma_state *mas, unsigned long size)
 	if (!ma_is_leaf(type))
 		gaps = ma_gaps(node, type);
 
-	min = _mas_safe_pivot(mas, pivots, offset, type) + 1;
+	min = _mas_safe_pivot(mas, pivots, mas->offset, type) + 1;
 	do {
 		max = min - 1;
-		min = mas_safe_min(mas, pivots, offset);
+		min = mas_safe_min(mas, pivots, mas->offset);
 		if (mas->last < min)
 			continue;
 
@@ -3857,8 +3856,8 @@ bool _mas_rev_awalk(struct ma_state *mas, unsigned long size)
 		}
 
 		if (!ma_is_leaf(type))
-			gap = gaps[offset];
-		else if (mas_slot(mas, slots, offset))
+			gap = gaps[mas->offset];
+		else if (mas_slot(mas, slots, mas->offset))
 			continue; // no gap in leaf.
 		else
 			gap = max - min + 1;
@@ -3872,19 +3871,18 @@ bool _mas_rev_awalk(struct ma_state *mas, unsigned long size)
 		if (ma_is_leaf(type)) {
 			mas->min = min;
 			mas->max = min + gap - 1;
-			mas->offset = offset;
 			return true;
 		}
 		break;
-	} while (offset--);
+	} while (mas->offset--);
 
-	if (offset >= mt_slots[type]) {  // Overflow, node exhausted.
-		offset = 0;
+	if (mas->offset >= mt_slots[type]) {  // Overflow, node exhausted.
+		mas->offset = 0;
 		goto ascend;
 	}
 
 	//descend
-	mas->node = mas_slot(mas, slots, offset);
+	mas->node = mas_slot(mas, slots, mas->offset);
 	mas->min = min;
 	mas->max = max;
 	mas->offset = mas_data_end(mas);
@@ -3894,7 +3892,6 @@ ascend:
 	if (mte_is_root(mas->node))
 		mas_set_err(mas, -EBUSY);
 
-	mas->offset = offset;
 	return false;
 }