Save the current wake up latency of a core. This latency is not always the latency of a defined c-state but can also be an intermediate value when a core is ready to shutdown (timer migration, cache flush ...) but wait for the last core of the cluster to finalize the cluster power down. This latter use case is not manage by the current version of the patch because it implies that the cpuidle drivers set the wake up latency instead of the cpuidle core.
Signed-off-by: Vincent Guittot vincent.guittot@linaro.org
Conflicts:
drivers/cpuidle/cpuidle.c --- drivers/cpuidle/cpuidle.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index d75040d..7b6553b 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -19,6 +19,7 @@ #include <linux/ktime.h> #include <linux/hrtimer.h> #include <linux/module.h> +#include <linux/sched.h> #include <trace/events/power.h>
#include "cpuidle.h" @@ -42,6 +43,12 @@ void disable_cpuidle(void) off = 1; }
+static void cpuidle_set_current_state(int cpu, int latency) +{ + struct sched_pm *stat = &per_cpu(sched_stat, cpu); + + atomic_set(&(stat->wake_latency), latency); +} /** * cpuidle_play_dead - cpu off-lining * @@ -79,12 +86,16 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, ktime_t time_start, time_end; s64 diff;
+ cpuidle_set_current_state(dev->cpu, target_state->exit_latency); + time_start = ktime_get();
entered_state = target_state->enter(dev, drv, index);
time_end = ktime_get();
+ cpuidle_set_current_state(dev->cpu, 0); + local_irq_enable();
diff = ktime_to_us(ktime_sub(time_end, time_start));