diff mbox

[2/5] cpuidle/idle: Move the cpuidle_idle_call function to idle.c

Message ID 1392131491-5265-2-git-send-email-daniel.lezcano@linaro.org
State New
Headers show

Commit Message

Daniel Lezcano Feb. 11, 2014, 3:11 p.m. UTC 
The cpuidle_idle_call does nothing more than calling the three individuals
function and is no longer used by any arch specific code but only in the
cpuidle framework code.

We can move this function into the idle task code to ensure better
proximity to the scheduler code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
---
 drivers/cpuidle/cpuidle.c |   37 -------------------------------------
 include/linux/cpuidle.h   |    2 --
 kernel/sched/idle.c       |   44 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+), 39 deletions(-)

Comments

Daniel Lezcano Feb. 12, 2014, 12:35 p.m. UTC | #1 
On 02/12/2014 11:43 AM, Preeti U Murthy wrote:
> Hi Daniel,
>
> On 02/11/2014 08:41 PM, Daniel Lezcano wrote:
>> The cpuidle_idle_call does nothing more than calling the three individuals
>> function and is no longer used by any arch specific code but only in the
>> cpuidle framework code.
>>
>> We can move this function into the idle task code to ensure better
>> proximity to the scheduler code.
>
> So my understanding of this patchset is that by moving
> cpuidle_idle_call() under kernel/sched, we now have a way of calling
> into the cpuidle governor and the cpuidle driver with additional
> parameters like cpu_load(), idle_stamp etc.. so that we can expect the
> governor and driver to take better decisions about entry and exit into
> idle states. Is this the advantage we hope to begin with?

Yes, right.
diff mbox

Patch

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 172ab6a..ae3078b 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -173,43 +173,6 @@  void cpuidle_reflect(struct cpuidle_device *dev, int index)
 }
 
 /**
- * cpuidle_idle_call - the main idle loop
- *
- * NOTE: no locks or semaphores should be used here
- * return non-zero on failure
- */
-int 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;
-
-	/* ask the governor for the next state */
-	next_state = cpuidle_select(drv, dev);
-	if (next_state < 0)
-		return next_state;
-
-	if (need_resched()) {
-		dev->last_residency = 0;
-		/* give the governor an opportunity to reflect on the outcome */
-		cpuidle_reflect(dev, next_state);
-		local_irq_enable();
-		return 0;
-	}
-
-	trace_cpu_idle_rcuidle(next_state, dev->cpu);
-
-	entered_state = cpuidle_enter(drv, dev, next_state);
-
-	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
-
-	/* give the governor an opportunity to reflect on the outcome */
-	cpuidle_reflect(dev, entered_state);
-
-	return 0;
-}
-
-/**
  * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
  */
 void cpuidle_install_idle_handler(void)
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index bf06f37..0befaff 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -126,7 +126,6 @@  extern int cpuidle_enter(struct cpuidle_driver *drv,
 			 struct cpuidle_device *dev, int index);
 extern void cpuidle_reflect(struct cpuidle_device *dev, int index);
 
-extern int cpuidle_idle_call(void);
 extern int cpuidle_register_driver(struct cpuidle_driver *drv);
 extern struct cpuidle_driver *cpuidle_get_driver(void);
 extern struct cpuidle_driver *cpuidle_driver_ref(void);
@@ -155,7 +154,6 @@  static inline int cpuidle_enter(struct cpuidle_driver *drv,
 				struct cpuidle_device *dev, int index)
 {return -ENODEV; }
 static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { }
-static inline int cpuidle_idle_call(void) { return -ENODEV; }
 static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
 {return -ENODEV; }
 static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index 14ca434..6963822 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -63,6 +63,50 @@  void __weak arch_cpu_idle(void)
 	local_irq_enable();
 }
 
+#ifdef CONFIG_CPU_IDLE
+/**
+ * cpuidle_idle_call - the main idle function
+ *
+ * NOTE: no locks or semaphores should be used here
+ * return non-zero on failure
+ */
+static int 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;
+
+	/* ask the governor for the next state */
+	next_state = cpuidle_select(drv, dev);
+	if (next_state < 0)
+		return next_state;
+
+	if (need_resched()) {
+		dev->last_residency = 0;
+		/* give the governor an opportunity to reflect on the outcome */
+		cpuidle_reflect(dev, next_state);
+		local_irq_enable();
+		return 0;
+	}
+
+	trace_cpu_idle_rcuidle(next_state, dev->cpu);
+
+	entered_state = cpuidle_enter(drv, dev, next_state);
+
+	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
+
+	/* give the governor an opportunity to reflect on the outcome */
+	cpuidle_reflect(dev, entered_state);
+
+	return 0;
+}
+#else
+static inline int cpuidle_idle_call(void)
+{
+	return -ENODEV;
+}
+#endif
+
 /*
  * Generic idle loop implementation
  */