Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755358Ab2FSX6S (ORCPT ); Tue, 19 Jun 2012 19:58:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:37512 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751466Ab2FSX6Q (ORCPT ); Tue, 19 Jun 2012 19:58:16 -0400 Date: Tue, 19 Jun 2012 16:58:15 -0700 From: Andrew Morton To: Kamezawa Hiroyuki Cc: linux-mm , Linux Kernel Mailing List , cgroups@vger.kernel.org, Michal Hocko , Johannes Weiner Subject: Re: [PATCH 2/2] memcg: clean up force_empty_list() return value check Message-Id: <20120619165815.5ce24be7.akpm@linux-foundation.org> In-Reply-To: <4FDF1830.1000504@jp.fujitsu.com> References: <4FDF17A3.9060202@jp.fujitsu.com> <4FDF1830.1000504@jp.fujitsu.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1328 Lines: 40 On Mon, 18 Jun 2012 20:59:44 +0900 Kamezawa Hiroyuki wrote: > > By commit "memcg: move charges to root cgroup if use_hierarchy=0" > mem_cgroup_move_parent() only returns -EBUSY, -EINVAL. > So, we can remove -ENOMEM and -EINTR checks. > > Signed-off-by: KAMEZAWA Hiroyuki > --- > mm/memcontrol.c | 5 ----- > 1 files changed, 0 insertions(+), 5 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index cf8a0f6..726b7c6 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -3847,8 +3847,6 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, > pc = lookup_page_cgroup(page); > > ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL); > - if (ret == -ENOMEM || ret == -EINTR) > - break; > > if (ret == -EBUSY || ret == -EINVAL) { This looks a bit fragile - if mem_cgroup_move_parent() is later changed (intentionally or otherwise!) to return -Esomethingelse then mem_cgroup_force_empty_list() will subtly break. Why not just do if (ret < 0) here? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/