linux-kernel - [PATCH 03/12] maple_tree: use percpu sheaves for maple_node

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Message-Id: <20250901-maple-sheaves-v1-3-d6a1166b53f2@suse.cz>
Date: Mon, 01 Sep 2025 13:08:53 +0200
From: Vlastimil Babka <vbabka@...e.cz>
To: "Liam R. Howlett" <Liam.Howlett@...cle.com>, 
 Matthew Wilcox <willy@...radead.org>, 
 Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, Jann Horn <jannh@...gle.com>, 
 Pedro Falcato <pfalcato@...e.de>, Suren Baghdasaryan <surenb@...gle.com>
Cc: Harry Yoo <harry.yoo@...cle.com>, 
 Andrew Morton <akpm@...ux-foundation.org>, maple-tree@...ts.infradead.org, 
 linux-mm@...ck.org, linux-fsdevel@...r.kernel.org, 
 linux-kernel@...r.kernel.org, Vlastimil Babka <vbabka@...e.cz>
Subject: [PATCH 03/12] maple_tree: use percpu sheaves for maple_node_cache

Setup the maple_node_cache with percpu sheaves of size 32 to hopefully
improve its performance. Note this will not immediately take advantage
of sheaf batching of kfree_rcu() operations due to the maple tree using
call_rcu with custom callbacks. The followup changes to maple tree will
change that and also make use of the prefilled sheaves functionality.

Signed-off-by: Vlastimil Babka <vbabka@...e.cz>
Reviewed-by: Suren Baghdasaryan <surenb@...gle.com>
---
 lib/maple_tree.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index b4ee2d29d7a962ca374467d0533185f2db3d35ff..a0db6bdc63793b8bbd544e246391d99e880dede3 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -6302,9 +6302,14 @@ bool mas_nomem(struct ma_state *mas, gfp_t gfp)

 void __init maple_tree_init(void)
 {
+	struct kmem_cache_args args = {
+		.align  = sizeof(struct maple_node),
+		.sheaf_capacity = 32,
+	};
+
 	maple_node_cache = kmem_cache_create("maple_node",
-			sizeof(struct maple_node), sizeof(struct maple_node),
-			SLAB_PANIC, NULL);
+			sizeof(struct maple_node), &args,
+			SLAB_PANIC);
 }

 /**

-- 
2.51.0