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* [PATCH] maple_tree: Use ma_dead_node() in mte_dead_node()
@ 2025-02-11  7:18 I Hsin Cheng
  2025-02-11 15:34 ` Liam R. Howlett
  0 siblings, 1 reply; 2+ messages in thread
From: I Hsin Cheng @ 2025-02-11  7:18 UTC (permalink / raw)
  To: Liam.Howlett
  Cc: akpm, linux-kernel, maple-tree, linux-mm, jserv, skhan, I Hsin Cheng

Utilize ma_dead_node() in mte_dead_node(). It can prevent decoding the
maple enode for a second time. Use the "node" to find parent for
comparison.

Signed-off-by: I Hsin Cheng <richard120310@gmail.com>
---
 lib/maple_tree.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f7153ade1be5..362f85c62678 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -584,13 +584,10 @@ static __always_inline bool ma_dead_node(const struct maple_node *node)
  */
 static __always_inline bool mte_dead_node(const struct maple_enode *enode)
 {
-	struct maple_node *parent, *node;
+	struct maple_node *node;
 
 	node = mte_to_node(enode);
-	/* Do not reorder reads from the node prior to the parent check */
-	smp_rmb();
-	parent = mte_parent(enode);
-	return (parent == node);
+	return ma_dead_node(node);
 }
 
 /*
-- 
2.43.0



^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] maple_tree: Use ma_dead_node() in mte_dead_node()
  2025-02-11  7:18 [PATCH] maple_tree: Use ma_dead_node() in mte_dead_node() I Hsin Cheng
@ 2025-02-11 15:34 ` Liam R. Howlett
  0 siblings, 0 replies; 2+ messages in thread
From: Liam R. Howlett @ 2025-02-11 15:34 UTC (permalink / raw)
  To: I Hsin Cheng; +Cc: akpm, linux-kernel, maple-tree, linux-mm, jserv, skhan

* I Hsin Cheng <richard120310@gmail.com> [250211 02:19]:
> Utilize ma_dead_node() in mte_dead_node(). It can prevent decoding the
> maple enode for a second time. Use the "node" to find parent for
> comparison.

This is much better, thanks.

> 
> Signed-off-by: I Hsin Cheng <richard120310@gmail.com>


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

> ---
>  lib/maple_tree.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)

In the future, please include a link and changes to v1 here.  This is
instead of a cover letter for a single patch.

v1: https://lore.kernel.org/linux-mm/20250210083526.252955-1-richard120310@gmail.com/

Also, the subject should have v2.

> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index f7153ade1be5..362f85c62678 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -584,13 +584,10 @@ static __always_inline bool ma_dead_node(const struct maple_node *node)
>   */
>  static __always_inline bool mte_dead_node(const struct maple_enode *enode)
>  {
> -	struct maple_node *parent, *node;
> +	struct maple_node *node;
>  
>  	node = mte_to_node(enode);
> -	/* Do not reorder reads from the node prior to the parent check */
> -	smp_rmb();
> -	parent = mte_parent(enode);
> -	return (parent == node);
> +	return ma_dead_node(node);
>  }
>  
>  /*
> -- 
> 2.43.0
> 


^ permalink raw reply	[flat|nested] 2+ messages in thread

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2025-02-11  7:18 [PATCH] maple_tree: Use ma_dead_node() in mte_dead_node() I Hsin Cheng
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