diff options
| author | Daniel Lezcano <daniel.lezcano@linaro.org> | 2014-11-26 15:31:47 +0100 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2016-01-06 13:42:50 +0100 |
| commit | 871f245312591c600beb1001779c17d05796142f (patch) | |
| tree | 8f1f01eb9fe9a61b32a7b676b73fddcef880da77 | |
| parent | 31c02a320e4f632c48b9ddd7876fa45a7c5f053f (diff) | |
cpuidle: Store the idle start time stamp
The scheduler uses the idle timestamp stored in the struct rq to retrieve the
time when the cpu went idle in order to find the idlest cpu. Unfortunately
this information is wrong as it does not have the same meaning from the cpuidle
point of view. The idle_stamp in the struct rq gives the information when the
idle task has been scheduled while the idle task could be interrupted several
times and the cpu going through an idle/wakeup multiple times.
Add the idle start time in the idle state structure.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Conflicts:
drivers/cpuidle/cpuidle.c
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 10 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 1 |
2 files changed, 7 insertions, 4 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 309aa0fe5163..f2d6776aa824 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -174,7 +174,6 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, struct cpuidle_state *target_state = &drv->states[index]; bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); - ktime_t time_start, time_end; s64 diff; /* @@ -196,13 +195,17 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, sched_idle_set_state(target_state); trace_cpu_idle_rcuidle(index, dev->cpu); - time_start = ktime_get(); + + target_state->idle_stamp = ktime_get_ns(); stop_critical_timings(); entered_state = target_state->enter(dev, drv, index); start_critical_timings(); - time_end = ktime_get(); + diff = (ktime_get_ns() - target_state->idle_stamp) >> 10; + + target_state->idle_stamp = 0; + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); /* The cpu is no longer idle or about to enter idle. */ @@ -218,7 +221,6 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, if (!cpuidle_state_is_coupled(drv, entered_state)) local_irq_enable(); - diff = ktime_to_us(ktime_sub(time_end, time_start)); if (diff > INT_MAX) diff = INT_MAX; diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 0884d76ea9e8..3f8ccd532927 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -44,6 +44,7 @@ struct cpuidle_state { int power_usage; /* in mW */ unsigned int target_residency; /* in US */ bool disabled; /* disabled on all CPUs */ + u64 idle_stamp; int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, |