From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752584Ab1AKGBW (ORCPT ); Tue, 11 Jan 2011 01:01:22 -0500 Received: from mail-yw0-f46.google.com ([209.85.213.46]:35835 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751035Ab1AKGBR (ORCPT ); Tue, 11 Jan 2011 01:01:17 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer; b=lmIS4zlmM8TcJCDAoj9eud1u2uB/2XYQHAgNu71EiBW5gMOnuycVjH4f2ZOvMTMGjr bZL0Is3TcBTEkSgEUa6CSz45OH0OQOEHbYYSrb6EU5E30WgeCGRB1laLj+mxhxDO7Wxy Zq7Uf0z++6waftCIwWdCwUW0wCzzOGuq3Gfrg= From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , KAMEZAWA Hiroyuki , Balbir Singh , Daisuke Nishimura , Minchan Kim Subject: [PATCH] memcg: remove charge variable in unmap_and_move Date: Tue, 11 Jan 2011 15:00:50 +0900 Message-Id: <1294725650-4732-1-git-send-email-minchan.kim@gmail.com> X-Mailer: git-send-email 1.7.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org memcg charge/uncharge could be handled by mem_cgroup_[prepare/end] migration itself so charge local variable in unmap_and_move lost the role since we introduced 01b1ae63c2. In addition, the variable name is not good like below. int unmap_and_move() { charge = mem_cgroup_prepare_migration(xxx); .. BUG_ON(charge); <-- BUG if it is charged? .. uncharge: if (!charge) <-- why do we have to uncharge !charge? mem_group_end_migration(xxx); .. } So let's remove unnecessary and confusing variable. Suggested-by: Daisuke Nishimura Signed-off-by: Minchan Kim Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki --- mm/migrate.c | 12 ++++-------- 1 files changed, 4 insertions(+), 8 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index b8a32da..e393841 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -623,7 +623,6 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, struct page *newpage = get_new_page(page, private, &result); int remap_swapcache = 1; int rcu_locked = 0; - int charge = 0; struct mem_cgroup *mem = NULL; struct anon_vma *anon_vma = NULL; @@ -662,12 +661,10 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, } /* charge against new page */ - charge = mem_cgroup_prepare_migration(page, newpage, &mem); - if (charge == -ENOMEM) { - rc = -ENOMEM; + rc = mem_cgroup_prepare_migration(page, newpage, &mem); + if (rc == -ENOMEM) goto unlock; - } - BUG_ON(charge); + BUG_ON(rc); if (PageWriteback(page)) { if (!force || !sync) @@ -760,8 +757,7 @@ rcu_unlock: if (rcu_locked) rcu_read_unlock(); uncharge: - if (!charge) - mem_cgroup_end_migration(mem, page, newpage, rc == 0); + mem_cgroup_end_migration(mem, page, newpage, rc == 0); unlock: unlock_page(page); -- 1.7.0.4