linux-kernel - [tip:timers/core] nohz: Remove ts-> Einidle checks before restarting the tick

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Message-ID: <tip-15f827be93928890bba965bc175caee50c4406d2@git.kernel.org>
Date:	Wed, 15 Feb 2012 11:38:29 -0800
From:	tip-bot for Frederic Weisbecker <fweisbec@...il.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
	a.p.zijlstra@...llo.nl, john.stultz@...aro.org, fweisbec@...il.com,
	tglx@...utronix.de, yong.zhang0@...il.com, mingo@...e.hu
Subject: [tip:timers/core] nohz: Remove ts->
 Einidle checks before restarting the tick

Commit-ID:  15f827be93928890bba965bc175caee50c4406d2
Gitweb:     http://git.kernel.org/tip/15f827be93928890bba965bc175caee50c4406d2
Author:     Frederic Weisbecker <fweisbec@...il.com>
AuthorDate: Tue, 24 Jan 2012 18:59:43 +0100
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Wed, 15 Feb 2012 15:23:09 +0100

nohz: Remove ts->Einidle checks before restarting the tick

ts->inidle is set by tick_nohz_idle_enter() and unset by
tick_nohz_idle_exit(). However these two calls are assumed
to be always paired. This means that by the time we call
tick_nohz_idle_exit(), ts->inidle is supposed to be always
set to 1.

Remove the checks for ts->inidle in tick_nohz_idle_exit().
This simplifies a bit the code and improves its debuggability
(ie: ensure the call is paired with a tick_nohz_idle_enter()
call).

Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
Reviewed-by: Yong Zhang <yong.zhang0@...il.com>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: John Stultz <john.stultz@...aro.org>
Cc: Ingo Molnar <mingo@...e.hu>
Link: http://lkml.kernel.org/r/1327427984-23282-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
 kernel/time/tick-sched.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 8cfffd9..3526038 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -558,20 +558,21 @@ void tick_nohz_idle_exit(void)
 
 	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;
-
 	/* Update jiffies first */
 	select_nohz_load_balancer(0);
 	tick_do_update_jiffies64(now);
--
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