From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758208Ab2C1LC2 (ORCPT ); Wed, 28 Mar 2012 07:02:28 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:49982 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757831Ab2C1LC0 (ORCPT ); Wed, 28 Mar 2012 07:02:26 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <4F72EF56.4030606@jp.fujitsu.com> Date: Wed, 28 Mar 2012 20:00:38 +0900 From: KAMEZAWA Hiroyuki User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:11.0) Gecko/20120312 Thunderbird/11.0 MIME-Version: 1.0 To: "linux-mm@kvack.org" CC: Linux Kernel , Michal Hocko , Johannes Weiner , Andrew Morton , Han Ying , Glauber Costa , Konstantin Khlebnikov , Suleiman Souhlal Subject: [RFC][PATCH 5/6] memcg: remove unnecessary memory barrier. References: <4F72EB84.7080000@jp.fujitsu.com> In-Reply-To: <4F72EB84.7080000@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now, Used bit and a pointer to memory cgroup are set at once. memory barrier for Used bit -> pc->mem_cgroup is not necessary. Signed-off-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 622fd2e..767bef3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1258,8 +1258,6 @@ mem_cgroup_get_reclaim_stat_from_page(struct page *page) pc = lookup_page_cgroup(page); if (!PageCgroupUsed(pc)) return NULL; - /* Ensure pc's mem_cgroup is visible after reading PCG_USED. */ - smp_rmb(); mz = page_cgroup_zoneinfo(pc_to_mem_cgroup(pc), page); return &mz->reclaim_stat; } -- 1.7.4.1