linux-kernel - [RFC/PATCH 5/6] memcg: optimize branch

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

Message-Id: <20080514171110.8cf4d4e1.kamezawa.hiroyu@jp.fujitsu.com>
Date:	Wed, 14 May 2008 17:11:10 +0900
From:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
To:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"balbir@...ux.vnet.ibm.com" <balbir@...ux.vnet.ibm.com>,
	"lizf@...fujitsu.com" <lizf@...fujitsu.com>,
	"xemul@...nvz.org" <xemul@...nvz.org>,
	"yamamoto@...inux.co.jp" <yamamoto@...inux.co.jp>,
	"hugh@...itas.com" <hugh@...itas.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [RFC/PATCH 5/6] memcg: optimize branch

Showing brach direction for obvious conditions.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>

---
 mm/memcontrol.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Index: linux-2.6.26-rc2/mm/memcontrol.c
===================================================================
--- linux-2.6.26-rc2.orig/mm/memcontrol.c
+++ linux-2.6.26-rc2/mm/memcontrol.c
@@ -550,7 +550,7 @@ retry:
 	 * The page_cgroup exists and
 	 * the page has already been accounted.
 	 */
-	if (pc) {
+	if (unlikely(pc)) {
 		VM_BUG_ON(pc->page != page);
 		VM_BUG_ON(!pc->mem_cgroup);
 		unlock_page_cgroup(page);
@@ -559,7 +559,7 @@ retry:
 	unlock_page_cgroup(page);
 
 	pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask);
-	if (pc == NULL)
+	if (unlikely(pc == NULL))
 		goto err;
 
 	/*
@@ -616,7 +616,7 @@ retry:
 		pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
 
 	lock_page_cgroup(page);
-	if (page_get_page_cgroup(page)) {
+	if (unlikely(page_get_page_cgroup(page))) {
 		unlock_page_cgroup(page);
 		/*
 		 * Another charge has been added to this page already.
@@ -689,7 +689,7 @@ void __mem_cgroup_uncharge_common(struct
 	 */
 	lock_page_cgroup(page);
 	pc = page_get_page_cgroup(page);
-	if (!pc)
+	if (unlikely(!pc))
 		goto unlock;
 
 	VM_BUG_ON(pc->page != page);

--
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/