3 files changed, 42 insertions, 0 deletions

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 5ce07b517c58..2e3148499368 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -16,6 +16,7 @@
 #include <linux/cpu.h>
 #include <linux/cpuidle.h>
 #include <linux/ktime.h>
+#include <linux/hrtimer.h>
 
 #include "cpuidle.h"
 
@@ -60,6 +61,12 @@ static void cpuidle_idle_call(void)
                 return;
         }
 
+        /*
+         * run any timers that can be run now, at this point
+         * before calculating the idle duration etc.
+         */
+        hrtimer_peek_ahead_timers();
+
         /* ask the governor for the next state */
         next_state = cpuidle_curr_governor->select(dev);
         if (need_resched())
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 95db11f62ff2..d93b1e1dc169 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -326,6 +326,11 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 extern ktime_t ktime_get(void);
 extern ktime_t ktime_get_real(void);
 
+
+DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
+extern void hrtimer_peek_ahead_timers(void);
+
+
 /* Exported timer functions: */
 
 /* Initialize timers: */
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 9a4c90185566..eb2cf984959f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1381,6 +1381,36 @@ void hrtimer_interrupt(struct clock_event_device *dev)
                 raise_softirq(HRTIMER_SOFTIRQ);
 }
 
+/**
+ * hrtimer_peek_ahead_timers -- run soft-expired timers now
+ *
+ * hrtimer_peek_ahead_timers will peek at the timer queue of
+ * the current cpu and check if there are any timers for which
+ * the soft expires time has passed. If any such timers exist,
+ * they are run immediately and then removed from the timer queue.
+ *
+ */
+void hrtimer_peek_ahead_timers(void)
+{
+        unsigned long flags;
+        struct tick_device *td;
+        struct clock_event_device *dev;
+
+        if (hrtimer_hres_active())
+                return;
+
+        local_irq_save(flags);
+        td = &__get_cpu_var(tick_cpu_device);
+        if (!td)
+                goto out;
+        dev = td->evtdev;
+        if (!dev)
+                goto out;
+        hrtimer_interrupt(dev);
+out:
+        local_irq_restore(flags);
+}
+
 static void run_hrtimer_softirq(struct softirq_action *h)
 {
         run_hrtimer_pending(&__get_cpu_var(hrtimer_bases));