From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756183Ab2ADP7x (ORCPT ); Wed, 4 Jan 2012 10:59:53 -0500 Received: from mail-gy0-f174.google.com ([209.85.160.174]:38996 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756145Ab2ADP7t (ORCPT ); Wed, 4 Jan 2012 10:59:49 -0500 Date: Wed, 4 Jan 2012 16:59:44 +0100 From: Frederic Weisbecker To: Thomas Gleixner Cc: LKML , Peter Zijlstra , Ingo Molnar Subject: Re: [PATCH] nohz: Remove ts->inidle checks before restarting the tick Message-ID: <20120104155939.GB1143@somewhere> References: <1323181843-12144-1-git-send-email-fweisbec@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1323181843-12144-1-git-send-email-fweisbec@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Just a ping to prevent this from being buried by the holidays :) Thanks. On Tue, Dec 06, 2011 at 03:30:43PM +0100, Frederic Weisbecker wrote: > ts->inidle is set by tick_nohz_stop_sched_tick(1) and unset > by tick_nohz_restart_sched_tick(). These two calls are assumed > to be always paired. This means that by the time we call > tick_nohz_restart_sched_tick(), ts->inidle is supposed to > be always set to 1. > > Remove the checks for ts->inidle in tick_nohz_restart_sched_tick(). > This simplifies a bit the code and improves its debuggability > (ie: ensure the call is paired with a tick_nohz_stop_sched_tick() call). > > Signed-off-by: Frederic Weisbecker > Cc: Peter Zijlstra > Cc: Ingo Molnar > --- > kernel/time/tick-sched.c | 12 +++++++----- > 1 files changed, 7 insertions(+), 5 deletions(-) > > diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c > index 4042064..0f7c5e5 100644 > --- a/kernel/time/tick-sched.c > +++ b/kernel/time/tick-sched.c > @@ -529,20 +529,22 @@ void tick_nohz_restart_sched_tick(void) > ktime_t now; > > local_irq_disable(); > - if (ts->idle_active || (ts->inidle && ts->tick_stopped)) > + > + WARN_ON_ONCE(!ts->inidle); > + > + ts->inidle = 0; > + > + if (ts->idle_active || ts->tick_stopped) > now = ktime_get(); > > if (ts->idle_active) > tick_nohz_stop_idle(cpu, now); > > - if (!ts->inidle || !ts->tick_stopped) { > - ts->inidle = 0; > + if (!ts->tick_stopped) { > local_irq_enable(); > return; > } > > - ts->inidle = 0; > - > rcu_exit_nohz(); > > /* Update jiffies first */ > -- > 1.7.5.4 >