A common piece of data used by cpuidle governors, is the information about
when the next timer/tick is going to fire. Rather than having each governor
calling tick_nohz_get_next_timer|hrtimer() separately, let's consolidate
the code by calling these functions before invoking the ->select() callback
of the governor - and store the output data in the struct cpuidle_device.
Besides the consolidation benefit, the purpose of this change is also to
make the information about the next timer/tick, available outside the
cpuidle framework. Following changes that implements a new genpd governor,
makes use of this.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
Changes in v11:
- New patch.
---
drivers/cpuidle/cpuidle.c | 2 ++
drivers/cpuidle/governors/menu.c | 6 ++----
drivers/cpuidle/governors/teo.c | 6 ++----
include/linux/cpuidle.h | 2 ++
4 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 7f108309e871..3b148253036b 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -312,6 +312,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
bool *stop_tick)
{
+ dev->next_timer = tick_nohz_get_next_timer();
+ dev->next_hrtimer = tick_nohz_get_next_hrtimer();
return cpuidle_curr_governor->select(drv, dev, stop_tick);
}
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 95e9122d6047..cdbe434e783d 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -287,8 +287,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
unsigned long nr_iowaiters;
ktime_t delta_next;
ktime_t now = ktime_get();
- ktime_t next_hrtimer = tick_nohz_get_next_hrtimer();
- ktime_t next_timer = tick_nohz_get_next_timer();
if (data->needs_update) {
menu_update(drv, dev);
@@ -298,14 +296,14 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
/*
* Compute the duration before the next timer, whatever the origin
*/
- delta_next = ktime_sub(next_timer, now);
+ delta_next = ktime_sub(dev->next_timer, now);
data->next_timer_us = ktime_to_us(delta_next);
/*
* Compute the duration before next hrtimer which is the tick
* or an earliest hrtimer
*/
- delta_next = ktime_sub(next_hrtimer, now);
+ delta_next = ktime_sub(dev->next_hrtimer, now);
nr_iowaiters = nr_iowait_cpu(dev->cpu);
data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c
index bef1e95c597e..7af9851d9d40 100644
--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -245,8 +245,6 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
int max_early_idx, idx, i;
ktime_t delta_tick;
ktime_t now = ktime_get();
- ktime_t next_hrtimer = tick_nohz_get_next_hrtimer();
- ktime_t next_timer = tick_nohz_get_next_timer();
if (cpu_data->last_state >= 0) {
teo_update(drv, dev);
@@ -255,8 +253,8 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
cpu_data->time_span_ns = local_clock();
- cpu_data->sleep_length_ns = ktime_sub(next_timer, now);
- delta_tick = ktime_sub(next_hrtimer, now);
+ cpu_data->sleep_length_ns = ktime_sub(dev->next_timer, now);
+ delta_tick = ktime_sub(dev->next_hrtimer, now);
duration_us = ktime_to_us(cpu_data->sleep_length_ns);
count = 0;
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 3b39472324a3..81ec924206f0 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -83,6 +83,8 @@ struct cpuidle_device {
unsigned int use_deepest_state:1;
unsigned int poll_time_limit:1;
unsigned int cpu;
+ ktime_t next_timer;
+ ktime_t next_hrtimer;
int last_residency;
struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
--
2.17.1
