This is a note to let you know that I've just added the patch titled
maple_tree: reduce resets during store setup
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
maple_tree-reduce-resets-during-store-setup.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fec29364348fec535c55708b1f4025b321aba572 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Date: Mon, 24 Jul 2023 14:31:56 -0400
Subject: maple_tree: reduce resets during store setup
From: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
commit fec29364348fec535c55708b1f4025b321aba572 upstream.
mas_prealloc() may walk partially down the tree before finding that a
split or spanning store is needed. When the write occurs, relax the
logic on resetting the walk so that partial walks will not restart, but
walks that have gone too far (a store that affects beyond the current
node) should be restarted.
Link: https://lkml.kernel.org/r/20230724183157.3939892-15-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 37 ++++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5439,19 +5439,34 @@ static inline void mte_destroy_walk(stru
static void mas_wr_store_setup(struct ma_wr_state *wr_mas)
{
+ if (mas_is_start(wr_mas->mas))
+ return;
+
if (unlikely(mas_is_paused(wr_mas->mas)))
- mas_reset(wr_mas->mas);
+ goto reset;
+
+ if (unlikely(mas_is_none(wr_mas->mas)))
+ goto reset;
+
+ /*
+ * A less strict version of mas_is_span_wr() where we allow spanning
+ * writes within this node. This is to stop partial walks in
+ * mas_prealloc() from being reset.
+ */
+ if (wr_mas->mas->last > wr_mas->mas->max)
+ goto reset;
+
+ if (wr_mas->entry)
+ return;
+
+ if (mte_is_leaf(wr_mas->mas->node) &&
+ wr_mas->mas->last == wr_mas->mas->max)
+ goto reset;
+
+ return;
- if (!mas_is_start(wr_mas->mas)) {
- if (mas_is_none(wr_mas->mas)) {
- mas_reset(wr_mas->mas);
- } else {
- wr_mas->r_max = wr_mas->mas->max;
- wr_mas->type = mte_node_type(wr_mas->mas->node);
- if (mas_is_span_wr(wr_mas))
- mas_reset(wr_mas->mas);
- }
- }
+reset:
+ mas_reset(wr_mas->mas);
}
/* Interface */
Patches currently in stable-queue which might be from Liam.Howlett@xxxxxxxxxx are
queue-6.5/maple_tree-add-mas_underflow-and-mas_overflow-states.patch
queue-6.5/maple_tree-add-mas_is_active-to-detect-in-tree-walks.patch
queue-6.5/maple_tree-reduce-resets-during-store-setup.patch
