linux-kernel - [PATCH] mm, slab_common: add 'unlikely' to size check of kmalloc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri,  2 Aug 2013 11:02:42 +0900
From:	Joonsoo Kim <iamjoonsoo.kim@....com>
To:	Pekka Enberg <penberg@...nel.org>
Cc:	Christoph Lameter <cl@...ux.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org, Joonsoo Kim <js1304@...il.com>,
	Joonsoo Kim <iamjoonsoo.kim@....com>
Subject: [PATCH] mm, slab_common: add 'unlikely' to size check of kmalloc_slab()

Size is usually below than KMALLOC_MAX_SIZE.
If we add a 'unlikely' macro, compiler can make better code.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@....com>

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 538bade..f0410eb 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -373,7 +373,7 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
 {
 	int index;
 
-	if (size > KMALLOC_MAX_SIZE) {
+	if (unlikely(size > KMALLOC_MAX_SIZE)) {
 		WARN_ON_ONCE(!(flags & __GFP_NOWARN));
 		return NULL;
 	}
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/