From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: [PATCH 2/3] cgroup: remove unnecessary 0 check from css_from_id() Date: Fri, 17 Jun 2016 12:24:27 -0400 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 Return-path: Content-Disposition: inline In-Reply-To: <20160617162310.GA19084-druUgvl0LCNAfugRpC6u6w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: Andrew Morton , Vladimir Davydov , Michal Hocko , Li Zefan , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.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