linux-kernel - [PATCH v3 16/16] maple_tree: remove unneeded mas_wr_walk() in mas_store

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Message-ID: <20240618204750.79512-17-sidhartha.kumar@oracle.com>
Date: Tue, 18 Jun 2024 13:47:50 -0700
From: Sidhartha Kumar <sidhartha.kumar@...cle.com>
To: linux-kernel@...r.kernel.org, maple-tree@...ts.infradead.org
Cc: linux-mm@...ck.org, akpm@...ux-foundation.org, liam.howlett@...cle.com,
        willy@...radead.org, Sidhartha Kumar <sidhartha.kumar@...cle.com>
Subject: [PATCH v3 16/16] maple_tree: remove unneeded mas_wr_walk() in mas_store_prealloc()

Users of mas_store_prealloc() enter this function with nodes already
preallocated. This means the store type must be already set. We can then
remove the call to mas_wr_store_type() and initialize the write state to
continue the partial walk that was done when determining the store type.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@...cle.com>
---
 lib/maple_tree.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f6a09bb7b291..634d49e39a02 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4027,9 +4027,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
 		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
 	else
 		wr_mas->end_piv = wr_mas->mas->max;
-
-	if (!wr_mas->entry)
-		mas_wr_extend_null(wr_mas);
 }
 
 static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
@@ -5590,8 +5587,19 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
 {
 	MA_WR_STATE(wr_mas, mas, entry);
 
-	mas_wr_prealloc_setup(&wr_mas);
-	mas_wr_store_type(&wr_mas);
+	if (mas->store_type == wr_store_root) {
+		mas_wr_prealloc_setup(&wr_mas);
+		goto store;
+	}
+
+	mas_wr_walk_descend(&wr_mas);
+	if (mas->store_type != wr_spanning_store) {
+		/* set wr_mas->content to current slot */
+		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
+		mas_wr_end_piv(&wr_mas);
+	}
+
+store:
 	trace_ma_write(__func__, mas, 0, entry);
 	mas_wr_store_entry(&wr_mas);
 	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
-- 
2.45.2