linux-kernel - [PATCH v1] mm/slab: Optimize the code logic in find

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Message-Id: <20240904074037.710692-1-xavier_qy@163.com>
Date: Wed,  4 Sep 2024 15:40:37 +0800
From: Xavier <xavier_qy@....com>
To: cl@...ux.com,
	penberg@...nel.org,
	rientjes@...gle.com,
	iamjoonsoo.kim@....com,
	akpm@...ux-foundation.org,
	vbabka@...e.cz,
	roman.gushchin@...ux.dev,
	42.hyeyoo@...il.com
Cc: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Xavier <xavier_qy@....com>
Subject: [PATCH v1] mm/slab: Optimize the code logic in find_mergeable()

We can first assess the flags, if it's unmergeable, there's no need
to calculate the size and align.

Signed-off-by: Xavier <xavier_qy@....com>
---
 mm/slab_common.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 40b582a014b8..aaf5989f7ffe 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -169,14 +169,15 @@ struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
 	if (ctor)
 		return NULL;
 
-	size = ALIGN(size, sizeof(void *));
-	align = calculate_alignment(flags, align, size);
-	size = ALIGN(size, align);
 	flags = kmem_cache_flags(flags, name);
 
 	if (flags & SLAB_NEVER_MERGE)
 		return NULL;
 
+	size = ALIGN(size, sizeof(void *));
+	align = calculate_alignment(flags, align, size);
+	size = ALIGN(size, align);
+
 	list_for_each_entry_reverse(s, &slab_caches, list) {
 		if (slab_unmergeable(s))
 			continue;
-- 
2.45.2