From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757114AbaJXS3Q (ORCPT ); Fri, 24 Oct 2014 14:29:16 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:46765 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756962AbaJXS3O (ORCPT ); Fri, 24 Oct 2014 14:29:14 -0400 Date: Fri, 24 Oct 2014 20:29:11 +0200 From: Michal Hocko To: Johannes Weiner Cc: Andrew Morton , Vladimir Davydov , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 1/3] mm: memcontrol: remove bogus NULL check after mem_cgroup_from_task() Message-ID: <20141024182911.GA18956@dhcp22.suse.cz> References: <1414158589-26094-1-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1414158589-26094-1-git-send-email-hannes@cmpxchg.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 24-10-14 09:49:47, Johannes Weiner wrote: > That function acts like a typecast - unless NULL is passed in, no NULL > can come out. task_in_mem_cgroup() callers don't pass NULL tasks. > > Signed-off-by: Johannes Weiner Thanks and sorry about my bogus version earlier today. Acked-by: Michal Hocko --- > mm/memcontrol.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 23cf27cca370..bdf8520979cf 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1335,7 +1335,7 @@ static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, > bool task_in_mem_cgroup(struct task_struct *task, > const struct mem_cgroup *memcg) > { > - struct mem_cgroup *curr = NULL; > + struct mem_cgroup *curr; > struct task_struct *p; > bool ret; > > @@ -1351,8 +1351,7 @@ bool task_in_mem_cgroup(struct task_struct *task, > */ > rcu_read_lock(); > curr = mem_cgroup_from_task(task); > - if (curr) > - css_get(&curr->css); > + css_get(&curr->css); > rcu_read_unlock(); > } > /* > -- > 2.1.2 > -- Michal Hocko SUSE Labs