diff options
| author | Daniel Lezcano <daniel.lezcano@linaro.org> | 2014-11-26 15:31:47 +0100 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2014-12-11 18:39:41 +0100 |
| commit | bdf23bdd203eb88fc97e12832060722e29a710aa (patch) | |
| tree | f562af2e4d0c3c66a270106e05b747587d1f1d94 | |
| parent | 82650ba07474e2fe7c4eedef874647abe552bdaa (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>
| -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 125150dc6e81..03f484368ba9 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -116,21 +116,23 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, int entered_state; struct cpuidle_state *target_state = &drv->states[index]; - ktime_t time_start, time_end; s64 diff; trace_cpu_idle_rcuidle(index, dev->cpu); - time_start = ktime_get(); + + target_state->idle_stamp = ktime_to_us(ktime_get()); entered_state = target_state->enter(dev, drv, index); - time_end = ktime_get(); + diff = ktime_to_us(ktime_sub_us(ktime_get(), target_state->idle_stamp)); + + target_state->idle_stamp = 0; + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); if (!cpuidle_state_is_coupled(dev, 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 a07e087f54b2..58b5d406cb71 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, |