diff mbox

[2/3] cpuidle: allow setting deepest idle

Message ID 1478718312-12847-3-git-send-email-jacob.jun.pan@linux.intel.com (mailing list archive)
State Superseded, archived
Delegated to: Zhang Rui
Headers show

Commit Message

Jacob Pan Nov. 9, 2016, 7:05 p.m. UTC 
When idle injection is used to cap power, we need to override
governor's choice of idle states. This patch allows caller to select
the deepest idle state on a CPU therefore achieve the maximum
potential power saving.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
 drivers/cpuidle/cpuidle.c | 12 ++++++++++++
 include/linux/cpuidle.h   |  4 +++-
 kernel/sched/idle.c       |  3 +++
 3 files changed, 18 insertions(+), 1 deletion(-)

Comments

Peter Zijlstra Nov. 14, 2016, 2:58 p.m. UTC | #1 
On Wed, Nov 09, 2016 at 11:05:11AM -0800, Jacob Pan wrote:
> --- a/kernel/sched/idle.c
> +++ b/kernel/sched/idle.c
> @@ -173,6 +173,9 @@ static void cpuidle_idle_call(void)
>  
>  		next_state = cpuidle_find_deepest_state(drv, dev);
>  		call_cpuidle(drv, dev, next_state);
> +	} else if (dev->use_deepest_state) {
> +			next_state = cpuidle_find_deepest_state(drv, dev);
> +			call_cpuidle(drv, dev, next_state);

looks like excessive indenting..

>  	} else {
>  		/*
>  		 * Ask the cpuidle framework to choose a convenient idle state.
> -- 
> 1.9.1
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index c73207a..9ad45b3 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -97,6 +97,18 @@  static int find_deepest_state(struct cpuidle_driver *drv,
 	return ret;
 }
 
+/* Set the current cpu to use the deepest idle state, override governors */
+void cpuidle_use_deepest_state(bool enable)
+{
+	struct cpuidle_device *dev;
+
+	preempt_disable();
+	dev = cpuidle_get_device();
+	dev->use_deepest_state = enable;
+	preempt_enable();
+}
+EXPORT_SYMBOL_GPL(cpuidle_use_deepest_state);
+
 #ifdef CONFIG_SUSPEND
 /**
  * cpuidle_find_deepest_state - Find the deepest available idle state.
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index bb31373..7f93c63 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -74,6 +74,7 @@  struct cpuidle_state {
 struct cpuidle_device {
 	unsigned int		registered:1;
 	unsigned int		enabled:1;
+	unsigned int		use_deepest_state:1;
 	unsigned int		cpu;
 
 	int			last_residency;
@@ -192,11 +193,12 @@  static inline struct cpuidle_driver *cpuidle_get_cpu_driver(
 static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; }
 #endif
 
-#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND)
+#if defined(CONFIG_CPU_IDLE)
 extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 				      struct cpuidle_device *dev);
 extern int cpuidle_enter_freeze(struct cpuidle_driver *drv,
 				struct cpuidle_device *dev);
+extern void cpuidle_use_deepest_state(bool enable);
 #else
 static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 					     struct cpuidle_device *dev)
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index ffd9a83..fc65147 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -173,6 +173,9 @@  static void cpuidle_idle_call(void)
 
 		next_state = cpuidle_find_deepest_state(drv, dev);
 		call_cpuidle(drv, dev, next_state);
+	} else if (dev->use_deepest_state) {
+			next_state = cpuidle_find_deepest_state(drv, dev);
+			call_cpuidle(drv, dev, next_state);
 	} else {
 		/*
 		 * Ask the cpuidle framework to choose a convenient idle state.