Date: Mon, 7 Nov 2016 19:36:54 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Chris Metcalf <cmetcalf@mellanox.com>
cc: Gilad Ben Yossef <giladb@mellanox.com>,
        Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Rik van Riel <riel@redhat.com>, Tejun Heo <tj@kernel.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Christoph Lameter <cl@linux.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Francis Giraldeau <francis.giraldeau@gmail.com>,
        Andi Kleen <andi@firstfloor.org>, Arnd Bergmann <arnd@arndb.de>,
        linux-kernel@vger.kernel.org
Subject: Re: task isolation discussion at Linux Plumbers
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On Mon, 7 Nov 2016, Thomas Gleixner wrote:
> > == Missing oneshot_stopped callbacks ==
> > 
> > I raised the issue that various clock_event_device sources don't
> > always support oneshot_stopped, which can cause an additional
> > final interrupt to occur after the timer infrastructure believes the
> > interrupt has been stopped.  I have patches to fix this for tile and
> > arm64 in my patch series; Thomas volunteered to look at adding
> > equivalent support for x86.
> 
> Right.

Untested patch below should fix that.

Thanks,

	tglx

8<---------------
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -530,18 +530,20 @@ static void lapic_timer_broadcast(const
  * The local apic timer can be used for any function which is CPU local.
  */
 static struct clock_event_device lapic_clockevent = {
-	.name			= "lapic",
-	.features		= CLOCK_EVT_FEAT_PERIODIC |
-				  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
-				  | CLOCK_EVT_FEAT_DUMMY,
-	.shift			= 32,
-	.set_state_shutdown	= lapic_timer_shutdown,
-	.set_state_periodic	= lapic_timer_set_periodic,
-	.set_state_oneshot	= lapic_timer_set_oneshot,
-	.set_next_event		= lapic_next_event,
-	.broadcast		= lapic_timer_broadcast,
-	.rating			= 100,
-	.irq			= -1,
+	.name				= "lapic",
+	.features			= CLOCK_EVT_FEAT_PERIODIC |
+					  CLOCK_EVT_FEAT_ONESHOT |
+					  CLOCK_EVT_FEAT_C3STOP |
+					  CLOCK_EVT_FEAT_DUMMY,
+	.shift				= 32,
+	.set_state_shutdown		= lapic_timer_shutdown,
+	.set_state_periodic		= lapic_timer_set_periodic,
+	.set_state_oneshot		= lapic_timer_set_oneshot,
+	.set_state_oneshot_stopped	= lapic_timer_shutdown,
+	.set_next_event			= lapic_next_event,
+	.broadcast			= lapic_timer_broadcast,
+	.rating				= 100,
+	.irq				= -1,
 };
 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);