This patch adds idle state time stamp to cpuidle device structure to
notify its current idle state. If last enter time is newer than last
exit time, then it means that the core is in idle now.
Signed-off-by: Jonghwa Lee <jonghwa3.lee@xxxxxxxxxxx>
---
drivers/cpuidle/cpuidle.c | 8 ++++----
include/linux/cpuidle.h | 4 ++++
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index eba6929..1e830cc 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -233,18 +233,18 @@ int cpuidle_wrap_enter(struct cpuidle_device *dev,
int (*enter)(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int index))
{
- ktime_t time_start, time_end;
s64 diff;
- time_start = ktime_get();
+ dev->last_idle_start = ktime_get();
index = enter(dev, drv, index);
- time_end = ktime_get();
+ dev->last_idle_end = ktime_get();
local_irq_enable();
- diff = ktime_to_us(ktime_sub(time_end, time_start));
+ diff = ktime_to_us(ktime_sub(dev->last_idle_end,
+ dev->last_idle_start));
if (diff > INT_MAX)
diff = INT_MAX;
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 480c14d..d1af05f 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -16,6 +16,7 @@
#include <linux/kobject.h>
#include <linux/completion.h>
#include <linux/hrtimer.h>
+#include <linux/ktime.h>
#define CPUIDLE_STATE_MAX 8
#define CPUIDLE_NAME_LEN 16
@@ -74,6 +75,9 @@ struct cpuidle_device {
struct kobject kobj;
struct completion kobj_unregister;
+ ktime_t last_idle_start;
+ ktime_t last_idle_end;
+
#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
int safe_state_index;
cpumask_t coupled_cpus;
--
1.7.9.5
--
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