+ maple_tree-reorder-mas-store_type-case-statements.patch added to mm-unstable branch

+ maple_tree-reorder-mas-store_type-case-statements.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: reorder mas->store_type case statements
has been added to the -mm mm-unstable branch.  Its filename is
     maple_tree-reorder-mas-store_type-case-statements.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-reorder-mas-store_type-case-statements.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: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Subject: maple_tree: reorder mas->store_type case statements
Date: Thu, 27 Feb 2025 20:48:23 +0000

Move the unlikely case that mas->store_type is invalid to be the last
evaluated case and put liklier cases higher up.

Link: https://lkml.kernel.org/r/20250227204823.758784-7-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Suggested-by: Liam R. Howlett <liam.howlett@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c |   51 ++++++++++++++++++++++-----------------------
 1 file changed, 25 insertions(+), 26 deletions(-)

--- a/lib/maple_tree.c~maple_tree-reorder-mas-store_type-case-statements
+++ a/lib/maple_tree.c
@@ -4089,15 +4089,6 @@ static inline void mas_wr_store_entry(st
 	unsigned char new_end = mas_wr_new_end(wr_mas);
 
 	switch (mas->store_type) {
-	case wr_invalid:
-		MT_BUG_ON(mas->tree, 1);
-		return;
-	case wr_new_root:
-		mas_new_root(mas, wr_mas->entry);
-		break;
-	case wr_store_root:
-		mas_store_root(mas, wr_mas->entry);
-		break;
 	case wr_exact_fit:
 		rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
 		if (!!wr_mas->entry ^ !!wr_mas->content)
@@ -4119,6 +4110,14 @@ static inline void mas_wr_store_entry(st
 	case wr_rebalance:
 		mas_wr_bnode(wr_mas);
 		break;
+	case wr_new_root:
+		mas_new_root(mas, wr_mas->entry);
+		break;
+	case wr_store_root:
+		mas_store_root(mas, wr_mas->entry);
+		break;
+	case wr_invalid:
+		MT_BUG_ON(mas->tree, 1);
 	}
 
 	return;
@@ -4183,19 +4182,10 @@ static inline int mas_prealloc_calc(stru
 	unsigned char delta = height - wr_mas->vacant_height;
 
 	switch (mas->store_type) {
-	case wr_invalid:
-		WARN_ON_ONCE(1);
-		break;
-	case wr_new_root:
-		ret = 1;
-		break;
-	case wr_store_root:
-		if (likely((mas->last != 0) || (mas->index != 0)))
-			ret = 1;
-		else if (((unsigned long) (entry) & 3) == 2)
-			ret = 1;
-		else
-			ret = 0;
+	case wr_exact_fit:
+	case wr_append:
+	case wr_slot_store:
+		ret = 0;
 		break;
 	case wr_spanning_store:
 		if (wr_mas->sufficient_height < wr_mas->vacant_height)
@@ -4215,10 +4205,19 @@ static inline int mas_prealloc_calc(stru
 	case wr_node_store:
 		ret = mt_in_rcu(mas->tree) ? 1 : 0;
 		break;
-	case wr_append:
-	case wr_exact_fit:
-	case wr_slot_store:
-		ret = 0;
+	case wr_new_root:
+		ret = 1;
+		break;
+	case wr_store_root:
+		if (likely((mas->last != 0) || (mas->index != 0)))
+			ret = 1;
+		else if (((unsigned long) (entry) & 3) == 2)
+			ret = 1;
+		else
+			ret = 0;
+		break;
+	case wr_invalid:
+		WARN_ON_ONCE(1);
 	}
 
 	return ret;
_

Patches currently in -mm which might be from sidhartha.kumar@oracle.com are

maple_tree-convert-mas_prealloc_calc-to-take-in-a-maple-write-state.patch
maple_tree-use-height-and-depth-consistently.patch
maple_tree-use-vacant-nodes-to-reduce-worst-case-allocations.patch
maple_tree-break-on-convergence-in-mas_spanning_rebalance.patch
maple_tree-add-sufficient-height.patch
maple_tree-reorder-mas-store_type-case-statements.patch