From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 6 Mar 2013 11:18:37 +0000 (+0000)
Subject: x86: Use tick broadcast expired check
X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=35b61edb41ffee58711850e76215b852386ddb10;p=linux-edison.git

x86: Use tick broadcast expired check

Avoid going back into deep idle if the tick broadcast IPI is about to
fire.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Arjan van de Veen <arjan@infradead.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20130306111537.702278273@linutronix.de
---

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 14ae10031ff..aa524da03bb 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -336,6 +336,18 @@ void cpu_idle(void)
 			local_touch_nmi();
 			local_irq_disable();
 
+			/*
+			 * We detected in the wakeup path that the
+			 * tick broadcast device expired for us, but
+			 * we raced with the other CPU and came back
+			 * here before it was able to fire the IPI.
+			 * No point in going idle.
+			 */
+			if (tick_check_broadcast_expired()) {
+				local_irq_enable();
+				continue;
+			}
+
 			enter_idle();
 
 			/* Don't trace irqs off for idle */