X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fkernel%2Fsched%2Fidle.c;h=4a2ef5a02fd3f91d7c4228378c23d5606bb73812;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=fefcb1fa5160139a41e9dd1fee74b20ef39105e0;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git

diff --git a/kernel/kernel/sched/idle.c b/kernel/kernel/sched/idle.c
index fefcb1fa5..4a2ef5a02 100644
--- a/kernel/kernel/sched/idle.c
+++ b/kernel/kernel/sched/idle.c
@@ -15,6 +15,15 @@
 
 #include "sched.h"
 
+/**
+ * sched_idle_set_state - Record idle state for the current CPU.
+ * @idle_state: State to record.
+ */
+void sched_idle_set_state(struct cpuidle_state *idle_state)
+{
+	idle_set_state(this_rq(), idle_state);
+}
+
 static int __read_mostly cpu_idle_force_poll;
 
 void cpu_idle_poll_ctrl(bool enable)
@@ -48,9 +57,11 @@ static inline int cpu_idle_poll(void)
 	rcu_idle_enter();
 	trace_cpu_idle_rcuidle(0, smp_processor_id());
 	local_irq_enable();
+	stop_critical_timings();
 	while (!tif_need_resched() &&
 		(cpu_idle_force_poll || tick_check_broadcast_expired()))
 		cpu_relax();
+	start_critical_timings();
 	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
 	rcu_idle_exit();
 	return 1;
@@ -67,6 +78,49 @@ void __weak arch_cpu_idle(void)
 	local_irq_enable();
 }
 
+/**
+ * default_idle_call - Default CPU idle routine.
+ *
+ * To use when the cpuidle framework cannot be used.
+ */
+void default_idle_call(void)
+{
+	if (current_clr_polling_and_test()) {
+		local_irq_enable();
+	} else {
+		stop_critical_timings();
+		arch_cpu_idle();
+		start_critical_timings();
+	}
+}
+
+static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
+		      int next_state)
+{
+	/* Fall back to the default arch idle method on errors. */
+	if (next_state < 0) {
+		default_idle_call();
+		return next_state;
+	}
+
+	/*
+	 * The idle task must be scheduled, it is pointless to go to idle, just
+	 * update no idle residency and return.
+	 */
+	if (current_clr_polling_and_test()) {
+		dev->last_residency = 0;
+		local_irq_enable();
+		return -EBUSY;
+	}
+
+	/*
+	 * Enter the idle state previously returned by the governor decision.
+	 * This function will block until an interrupt occurs and will take
+	 * care of re-enabling the local interrupts
+	 */
+	return cpuidle_enter(drv, dev, next_state);
+}
+
 /**
  * cpuidle_idle_call - the main idle function
  *
@@ -81,7 +135,6 @@ static void cpuidle_idle_call(void)
 	struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 	int next_state, entered_state;
-	bool reflect;
 
 	/*
 	 * Check if the idle task must be rescheduled. If it is the
@@ -92,12 +145,6 @@ static void cpuidle_idle_call(void)
 		return;
 	}
 
-	/*
-	 * During the idle period, stop measuring the disabled irqs
-	 * critical sections latencies
-	 */
-	stop_critical_timings();
-
 	/*
 	 * Tell the RCU framework we are entering an idle section,
 	 * so no more rcu read side critical sections and one more
@@ -105,8 +152,10 @@ static void cpuidle_idle_call(void)
 	 */
 	rcu_idle_enter();
 
-	if (cpuidle_not_available(drv, dev))
-		goto use_default;
+	if (cpuidle_not_available(drv, dev)) {
+		default_idle_call();
+		goto exit_idle;
+	}
 
 	/*
 	 * Suspend-to-idle ("freeze") is a system state in which all user space
@@ -124,52 +173,19 @@ static void cpuidle_idle_call(void)
 			goto exit_idle;
 		}
 
-		reflect = false;
 		next_state = cpuidle_find_deepest_state(drv, dev);
+		call_cpuidle(drv, dev, next_state);
 	} else {
-		reflect = true;
 		/*
 		 * Ask the cpuidle framework to choose a convenient idle state.
 		 */
 		next_state = cpuidle_select(drv, dev);
-	}
-	/* Fall back to the default arch idle method on errors. */
-	if (next_state < 0)
-		goto use_default;
-
-	/*
-	 * The idle task must be scheduled, it is pointless to
-	 * go to idle, just update no idle residency and get
-	 * out of this function
-	 */
-	if (current_clr_polling_and_test()) {
-		dev->last_residency = 0;
-		entered_state = next_state;
-		local_irq_enable();
-		goto exit_idle;
-	}
-
-	/* Take note of the planned idle state. */
-	idle_set_state(this_rq(), &drv->states[next_state]);
-
-	/*
-	 * Enter the idle state previously returned by the governor decision.
-	 * This function will block until an interrupt occurs and will take
-	 * care of re-enabling the local interrupts
-	 */
-	entered_state = cpuidle_enter(drv, dev, next_state);
-
-	/* The cpu is no longer idle or about to enter idle. */
-	idle_set_state(this_rq(), NULL);
-
-	if (entered_state == -EBUSY)
-		goto use_default;
-
-	/*
-	 * Give the governor an opportunity to reflect on the outcome
-	 */
-	if (reflect)
+		entered_state = call_cpuidle(drv, dev, next_state);
+		/*
+		 * Give the governor an opportunity to reflect on the outcome
+		 */
 		cpuidle_reflect(dev, entered_state);
+	}
 
 exit_idle:
 	__current_set_polling();
@@ -181,20 +197,6 @@ exit_idle:
 		local_irq_enable();
 
 	rcu_idle_exit();
-	start_critical_timings();
-	return;
-
-use_default:
-	/*
-	 * We can't use the cpuidle framework, let's use the default
-	 * idle routine.
-	 */
-	if (current_clr_polling_and_test())
-		local_irq_enable();
-	else
-		arch_cpu_idle();
-
-	goto exit_idle;
 }
 
 DEFINE_PER_CPU(bool, cpu_dead_idle);