From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757001AbbCCREu (ORCPT ); Tue, 3 Mar 2015 12:04:50 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:44918 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932263AbbCCREJ (ORCPT ); Tue, 3 Mar 2015 12:04:09 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, Yao Dongdong , "Paul E. McKenney" Subject: [PATCH tip/core/rcu 12/12] rcu: Remove redundant check of cpu_online() Date: Tue, 3 Mar 2015 09:03:55 -0800 Message-Id: <1425402235-11061-12-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 In-Reply-To: <1425402235-11061-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150303170329.GA8456@linux.vnet.ibm.com> <1425402235-11061-1-git-send-email-paulmck@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15030317-0017-0000-0000-0000092E57EA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yao Dongdong Because invoke_cpu_core() checks whether the current CPU is online, there is no need for __call_rcu_core() to redundantly check it. There should not be any performance degradation because the called function is visible to the compiler. This commit therefore removes the redundant check. Signed-off-by: Yao Dongdong Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 9820119f40b5..75366019e15c 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2741,7 +2741,7 @@ static void __call_rcu_core(struct rcu_state *rsp, struct rcu_data *rdp, * If called from an extended quiescent state, invoke the RCU * core in order to force a re-evaluation of RCU's idleness. */ - if (!rcu_is_watching() && cpu_online(smp_processor_id())) + if (!rcu_is_watching()) invoke_rcu_core(); /* If interrupts were disabled or CPU offline, don't invoke RCU core. */ -- 1.8.1.5