From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751977AbcKIGgL (ORCPT ); Wed, 9 Nov 2016 01:36:11 -0500 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:57261 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750905AbcKIGgK (ORCPT ); Wed, 9 Nov 2016 01:36:10 -0500 X-Original-SENDERIP: 156.147.1.125 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com From: Byungchul Park To: paulmck@linux.vnet.ibm.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com Cc: linux-kernel@vger.kernel.org Subject: [PATCH 1/2] rcu: Remove unnecessary condition in rcu_implicit_dynticks_qs Date: Wed, 9 Nov 2016 15:32:14 +0900 Message-Id: <1478673135-25509-1-git-send-email-byungchul.park@lge.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Given two conditions like, COND 1. jiffies >= rdp->rsp->gp_start + 2 * jiffies_till_sched_qs COND 2. jiffies >= rdp->rsp->gp_start + jiffies_till_sched_qs A set of jiffies satisfying COND 2 includes another set satisfying COND 1. Thus COND 1 can be removed from a condition, (COND 1 || COND 2). Signed-off-by: Byungchul Park --- kernel/rcu/tree.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 5d80925..d8e8859 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1220,9 +1220,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp, } /* And if it has been a really long time, kick the CPU as well. */ - if (ULONG_CMP_GE(jiffies, - rdp->rsp->gp_start + 2 * jiffies_till_sched_qs) || - ULONG_CMP_GE(jiffies, rdp->rsp->gp_start + jiffies_till_sched_qs)) + if (ULONG_CMP_GE(jiffies, rdp->rsp->gp_start + jiffies_till_sched_qs)) resched_cpu(rdp->cpu); /* Force CPU into scheduler. */ return 0; -- 1.9.1