The patch titled
Subject: maple_tree: remove extra smp_wmb() from mas_dead_leaves()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-remove-extra-smp_wmb-from-mas_dead_leaves.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-remove-extra-smp_wmb-from-mas_dead_leaves.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: Liam Howlett <Liam.Howlett@xxxxxxxxxx>
Subject: maple_tree: remove extra smp_wmb() from mas_dead_leaves()
Date: Mon, 27 Feb 2023 09:36:03 -0800
The call to mte_set_dead_node() before the smp_wmb() already calls
smp_wmb() so this is not needed. This is an optimization for the RCU mode
of the maple tree.
Link: https://lkml.kernel.org/r/20230227173632.3292573-5-surenb@xxxxxxxxxx
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/lib/maple_tree.c~maple_tree-remove-extra-smp_wmb-from-mas_dead_leaves
+++ a/lib/maple_tree.c
@@ -5517,7 +5517,6 @@ unsigned char mas_dead_leaves(struct ma_
break;
mte_set_node_dead(entry);
- smp_wmb(); /* Needed for RCU */
node->type = type;
rcu_assign_pointer(slots[offset], node);
}
_
Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are
mm-mprotect-fix-successful-vma_merge-of-next-in-do_mprotect_pkey.patch
maple_tree-be-more-cautious-about-dead-nodes.patch
maple_tree-detect-dead-nodes-in-mas_start.patch
maple_tree-fix-freeing-of-nodes-in-rcu-mode.patch
maple_tree-remove-extra-smp_wmb-from-mas_dead_leaves.patch
maple_tree-fix-write-memory-barrier-of-nodes-once-dead-for-rcu-mode.patch
maple_tree-add-smp_rmb-to-dead-node-detection.patch
maple_tree-add-rcu-lock-checking-to-rcu-callback-functions.patch
mm-enable-maple-tree-rcu-mode-by-default.patch
