From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752392Ab0EGFPZ (ORCPT ); Fri, 7 May 2010 01:15:25 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:62030 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750Ab0EGFPY convert rfc822-to-8bit (ORCPT ); Fri, 7 May 2010 01:15:24 -0400 MIME-Version: 1.0 In-Reply-To: <20100507100729.a6589d8a.kamezawa.hiroyu@jp.fujitsu.com> References: <1273058509-16625-1-git-send-email-ext-phil.2.carmody@nokia.com> <1273058509-16625-2-git-send-email-ext-phil.2.carmody@nokia.com> <20100506142417.6d317068.akpm@linux-foundation.org> <20100507100729.a6589d8a.kamezawa.hiroyu@jp.fujitsu.com> Date: Fri, 7 May 2010 08:15:22 +0300 Message-ID: Subject: Re: [PATCH 2/2] mm: memcontrol - uninitialised return value From: "Kirill A. Shutemov" To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Phil Carmody , balbir@linux.vnet.ibm.com, nishimura@mxp.nes.nec.co.jp, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Paul Menage , "lizf@cn.fujitsu.com" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 7, 2010 at 4:07 AM, KAMEZAWA Hiroyuki wrote: > On Thu, 6 May 2010 14:24:17 -0700 > Andrew Morton wrote: > >> On Wed,  5 May 2010 14:21:49 +0300 >> Phil Carmody wrote: >> >> > From: Phil Carmody >> > >> > Only an out of memory error will cause ret to be set. >> > >> > Acked-by: Kirill A. Shutemov >> > Signed-off-by: Phil Carmody >> > --- >> >  mm/memcontrol.c |    2 +- >> >  1 files changed, 1 insertions(+), 1 deletions(-) >> > >> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> > index 90e32b2..09af773 100644 >> > --- a/mm/memcontrol.c >> > +++ b/mm/memcontrol.c >> > @@ -3464,7 +3464,7 @@ static int mem_cgroup_unregister_event(struct cgroup *cgrp, struct cftype *cft, >> >     int type = MEMFILE_TYPE(cft->private); >> >     u64 usage; >> >     int size = 0; >> > -   int i, j, ret; >> > +   int i, j, ret = 0; >> > >> >     mutex_lock(&memcg->thresholds_lock); >> >     if (type == _MEM) >> >> afacit the return value of cftype.unregister_event() is always ignored >> anyway.  Perhaps it should be changed to void-returning, or fixed. >> >> > Ah, it's now "TODO". But hmm...."unregister_event()" is called by workqueue. > (for avoiding race?) Because it can be called from atomic context. > I think unregister_event should be "void" and mem_cgroup_unregister_event() > should be implemented as "never fail" function. > > I'll try by myself....but if someone knows this event notifier implementation well, > please. Ok, better if I'll do it.