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Subject[tip:timers/core] x86: Use tick broadcast expired check
Commit-ID:  35b61edb41ffee58711850e76215b852386ddb10
Gitweb: http://git.kernel.org/tip/35b61edb41ffee58711850e76215b852386ddb10
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Wed, 6 Mar 2013 11:18:37 +0000
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 13 Mar 2013 11:39:40 +0100

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
---
arch/x86/kernel/process.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 14ae100..aa524da 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 */

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