linux-kernel - [tip:timers/urgent] tick/broadcast: Move the check for periodic mode inside state handling

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Date:	Tue, 7 Jul 2015 10:13:52 -0700
From:	tip-bot for Thomas Gleixner <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	mingo@...nel.org, Catalin.Marinas@....com, Suzuki.Poulose@....com,
	peterz@...radead.org, Lorenzo.Pieralisi@....com,
	tglx@...utronix.de, hpa@...or.com, sudeep.holla@....com,
	preeti@...ux.vnet.ibm.com, rafael.j.wysocki@...el.com,
	linux-kernel@...r.kernel.org
Subject: [tip:timers/urgent] tick/broadcast:
  Move the check for periodic mode inside state handling

Commit-ID:  e3ac79e087ffe8a1f953ed44a74acf7616cb0b25
Gitweb:     http://git.kernel.org/tip/e3ac79e087ffe8a1f953ed44a74acf7616cb0b25
Author:     Thomas Gleixner <tglx@...utronix.de>
AuthorDate: Tue, 7 Jul 2015 16:38:11 +0200
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Tue, 7 Jul 2015 18:46:47 +0200

tick/broadcast: Move the check for periodic mode inside state handling

We need to check more than the periodic mode for proper operation in
all runtime combinations. To avoid code duplication move the check
into the enter state handling.

No functional change.

[ Split out from a larger combo patch ]

Reported-and-tested-by: Sudeep Holla <sudeep.holla@....com>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Suzuki Poulose <Suzuki.Poulose@....com>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@....com>
Cc: Catalin Marinas <Catalin.Marinas@....com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Preeti U Murthy <preeti@...ux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@...nel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
---
 kernel/time/tick-broadcast.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index fad3f78..83aa92e 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -688,7 +688,6 @@ static void broadcast_shutdown_local(struct clock_event_device *bc,
 int __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
 {
 	struct clock_event_device *bc, *dev;
-	struct tick_device *td;
 	int cpu, ret = 0;
 	ktime_t now;
 
@@ -699,25 +698,20 @@ int __tick_broadcast_oneshot_control(enum tick_broadcast_state state)
 	if (!tick_broadcast_device.evtdev)
 		return -EBUSY;
 
-	/*
-	 * Periodic mode does not care about the enter/exit of power
-	 * states
-	 */
-	if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
-		return 0;
-
-	/*
-	 * We are called with preemtion disabled from the depth of the
-	 * idle code, so we can't be moved away.
-	 */
-	td = this_cpu_ptr(&tick_cpu_device);
-	dev = td->evtdev;
+	dev = this_cpu_ptr(&tick_cpu_device)->evtdev;
 
 	raw_spin_lock(&tick_broadcast_lock);
 	bc = tick_broadcast_device.evtdev;
 	cpu = smp_processor_id();
 
 	if (state == TICK_BROADCAST_ENTER) {
+		/*
+		 * If the broadcast device is in periodic mode, we
+		 * return.
+		 */
+		if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
+			goto out;
+
 		if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_oneshot_mask)) {
 			WARN_ON_ONCE(cpumask_test_cpu(cpu, tick_broadcast_pending_mask));
 			broadcast_shutdown_local(bc, dev);
--
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