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authorVincent Guittot <vincent.guittot@linaro.org>2013-07-25 13:56:08 +0200
committerVincent Guittot <vincent.guittot@linaro.org>2013-09-05 16:00:24 +0200
commit9c735db29e91c7b4a272bdf2069ddc20bf09d340 (patch)
tree6036627e551e8cd246a8ae7d0b4bec2ea9b063da
parentf194fce720dea4a2cc38b54c027b42c027a83d01 (diff)
cpuidle: set the current wake up latency
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 to 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>
-rw-r--r--drivers/cpuidle/cpuidle.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index fdc432f18022..35e42e838f32 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"
@@ -44,6 +45,12 @@ void disable_cpuidle(void)
static int __cpuidle_register_device(struct cpuidle_device *dev);
+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
*
@@ -81,12 +88,16 @@ 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));