From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755585AbcFQQ06 (ORCPT ); Fri, 17 Jun 2016 12:26:58 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:60160 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751801AbcFQQ05 (ORCPT ); Fri, 17 Jun 2016 12:26:57 -0400 Date: Fri, 17 Jun 2016 12:24:27 -0400 From: Johannes Weiner To: Tejun Heo Cc: Andrew Morton , Vladimir Davydov , Michal Hocko , Li Zefan , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 2/3] cgroup: remove unnecessary 0 check from css_from_id() Message-ID: <20160617162427.GC19084@cmpxchg.org> References: <20160616034244.14839-1-hannes@cmpxchg.org> <20160616200617.GD3262@mtj.duckdns.org> <20160617162310.GA19084@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160617162310.GA19084@cmpxchg.org> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org css_idr allocation starts at 1, so index 0 will never point to an item. css_from_id() currently filters that before asking idr_find(), but idr_find() would also just return NULL, so this is not needed. Signed-off-by: Johannes Weiner --- kernel/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 36fc0ff506c3..78f6d18ff0af 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -6162,7 +6162,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss) { WARN_ON_ONCE(!rcu_read_lock_held()); - return id > 0 ? idr_find(&ss->css_idr, id) : NULL; + return idr_find(&ss->css_idr, id); } /** -- 2.8.3