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path: root/drivers/cpuidle
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Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle.c3
-rw-r--r--drivers/cpuidle/driver.c2
-rw-r--r--drivers/cpuidle/governors/menu.c75
3 files changed, 47 insertions, 33 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 09d05ab262be..cb20fd915be8 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -85,7 +85,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
time_end = ktime_get();
- local_irq_enable();
+ 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 --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 06dbe7c86199..136d6a283e0a 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -209,7 +209,7 @@ static void poll_idle_init(struct cpuidle_driver *drv)
state->exit_latency = 0;
state->target_residency = 0;
state->power_usage = -1;
- state->flags = 0;
+ state->flags = CPUIDLE_FLAG_TIME_VALID;
state->enter = poll_idle;
state->disabled = false;
}
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index cf7f2f0e4ef5..71b523293354 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -122,9 +122,8 @@ struct menu_device {
int last_state_idx;
int needs_update;
- unsigned int expected_us;
+ unsigned int next_timer_us;
unsigned int predicted_us;
- unsigned int exit_us;
unsigned int bucket;
unsigned int correction_factor[BUCKETS];
unsigned int intervals[INTERVALS];
@@ -257,7 +256,7 @@ again:
stddev = int_sqrt(stddev);
if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3))
|| stddev <= 20) {
- if (data->expected_us > avg)
+ if (data->next_timer_us > avg)
data->predicted_us = avg;
return;
}
@@ -289,7 +288,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
struct menu_device *data = &__get_cpu_var(menu_devices);
int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
int i;
- int multiplier;
+ unsigned int interactivity_req;
struct timespec t;
if (data->needs_update) {
@@ -298,7 +297,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
}
data->last_state_idx = 0;
- data->exit_us = 0;
/* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0))
@@ -306,13 +304,11 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
/* determine the expected residency time, round up */
t = ktime_to_timespec(tick_nohz_get_sleep_length());
- data->expected_us =
+ data->next_timer_us =
t.tv_sec * USEC_PER_SEC + t.tv_nsec / NSEC_PER_USEC;
- data->bucket = which_bucket(data->expected_us);
-
- multiplier = performance_multiplier();
+ data->bucket = which_bucket(data->next_timer_us);
/*
* if the correction factor is 0 (eg first time init or cpu hotplug
@@ -326,17 +322,26 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
* operands are 32 bits.
* Make sure to round up for half microseconds.
*/
- data->predicted_us = div_round64((uint64_t)data->expected_us *
+ data->predicted_us = div_round64((uint64_t)data->next_timer_us *
data->correction_factor[data->bucket],
RESOLUTION * DECAY);
get_typical_interval(data);
/*
+ * Performance multiplier defines a minimum predicted idle
+ * duration / latency ratio. Adjust the latency limit if
+ * necessary.
+ */
+ interactivity_req = data->predicted_us / performance_multiplier();
+ if (latency_req > interactivity_req)
+ latency_req = interactivity_req;
+
+ /*
* We want to default to C1 (hlt), not to busy polling
* unless the timer is happening really really soon.
*/
- if (data->expected_us > 5 &&
+ if (data->next_timer_us > 5 &&
!drv->states[CPUIDLE_DRIVER_STATE_START].disabled &&
dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0)
data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
@@ -355,11 +360,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
continue;
if (s->exit_latency > latency_req)
continue;
- if (s->exit_latency * multiplier > data->predicted_us)
- continue;
data->last_state_idx = i;
- data->exit_us = s->exit_latency;
}
return data->last_state_idx;
@@ -390,36 +392,47 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{
struct menu_device *data = &__get_cpu_var(menu_devices);
int last_idx = data->last_state_idx;
- unsigned int last_idle_us = cpuidle_get_last_residency(dev);
struct cpuidle_state *target = &drv->states[last_idx];
unsigned int measured_us;
unsigned int new_factor;
/*
- * Ugh, this idle state doesn't support residency measurements, so we
- * are basically lost in the dark. As a compromise, assume we slept
- * for the whole expected time.
+ * Try to figure out how much time passed between entry to low
+ * power state and occurrence of the wakeup event.
+ *
+ * If the entered idle state didn't support residency measurements,
+ * we are basically lost in the dark how much time passed.
+ * As a compromise, assume we slept for the whole expected time.
+ *
+ * Any measured amount of time will include the exit latency.
+ * Since we are interested in when the wakeup begun, not when it
+ * was completed, we must substract the exit latency. However, if
+ * the measured amount of time is less than the exit latency,
+ * assume the state was never reached and the exit latency is 0.
*/
- if (unlikely(!(target->flags & CPUIDLE_FLAG_TIME_VALID)))
- last_idle_us = data->expected_us;
+ if (unlikely(!(target->flags & CPUIDLE_FLAG_TIME_VALID))) {
+ /* Use timer value as is */
+ measured_us = data->next_timer_us;
+ } else {
+ /* Use measured value */
+ measured_us = cpuidle_get_last_residency(dev);
- measured_us = last_idle_us;
-
- /*
- * We correct for the exit latency; we are assuming here that the
- * exit latency happens after the event that we're interested in.
- */
- if (measured_us > data->exit_us)
- measured_us -= data->exit_us;
+ /* Deduct exit latency */
+ if (measured_us > target->exit_latency)
+ measured_us -= target->exit_latency;
+ /* Make sure our coefficients do not exceed unity */
+ if (measured_us > data->next_timer_us)
+ measured_us = data->next_timer_us;
+ }
/* Update our correction ratio */
new_factor = data->correction_factor[data->bucket];
new_factor -= new_factor / DECAY;
- if (data->expected_us > 0 && measured_us < MAX_INTERESTING)
- new_factor += RESOLUTION * measured_us / data->expected_us;
+ if (data->next_timer_us > 0 && measured_us < MAX_INTERESTING)
+ new_factor += RESOLUTION * measured_us / data->next_timer_us;
else
/*
* we were idle so long that we count it as a perfect
@@ -439,7 +452,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
data->correction_factor[data->bucket] = new_factor;
/* update the repeating-pattern data */
- data->intervals[data->interval_ptr++] = last_idle_us;
+ data->intervals[data->interval_ptr++] = measured_us;
if (data->interval_ptr >= INTERVALS)
data->interval_ptr = 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 09:44:22 +0000