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path: root/drivers/cpuidle
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Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/governors/menu.c42
1 files changed, 24 insertions, 18 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 27fc733cb5b9..00c5f891e352 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -196,7 +196,7 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev);
* of points is below a threshold. If it is... then use the
* average of these 8 points as the estimated value.
*/
-static void get_typical_interval(struct menu_device *data)
+static unsigned int get_typical_interval(struct menu_device *data)
{
int i, divisor;
unsigned int max, thresh, avg;
@@ -253,9 +253,7 @@ again:
if (likely(variance <= U64_MAX/36)) {
if ((((u64)avg*avg > variance*36) && (divisor * 4 >= INTERVALS * 3))
|| variance <= 400) {
- if (data->next_timer_us > avg)
- data->predicted_us = avg;
- return;
+ return avg;
}
}
@@ -269,7 +267,7 @@ again:
* with sporadic activity with a bunch of short pauses.
*/
if ((divisor * 4) <= INTERVALS * 3)
- return;
+ return UINT_MAX;
thresh = max - 1;
goto again;
@@ -286,6 +284,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
int i;
unsigned int interactivity_req;
+ unsigned int expected_interval;
unsigned long nr_iowaiters, cpu_load;
if (data->needs_update) {
@@ -312,32 +311,39 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
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(nr_iowaiters, cpu_load);
- if (latency_req > interactivity_req)
- latency_req = interactivity_req;
+ expected_interval = get_typical_interval(data);
+ expected_interval = min(expected_interval, data->next_timer_us);
if (CPUIDLE_DRIVER_STATE_START > 0) {
data->last_state_idx = CPUIDLE_DRIVER_STATE_START - 1;
/*
* We want to default to C1 (hlt), not to busy polling
- * unless the timer is happening really really soon.
+ * unless the timer is happening really really soon, or
+ * C1's exit latency exceeds the user configured limit.
*/
- if (interactivity_req > 20 &&
+ if (expected_interval > drv->states[CPUIDLE_DRIVER_STATE_START].target_residency &&
+ latency_req > drv->states[CPUIDLE_DRIVER_STATE_START].exit_latency &&
!drv->states[CPUIDLE_DRIVER_STATE_START].disabled &&
- dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0)
+ !dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable)
data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
} else {
data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
}
/*
+ * Use the lowest expected idle interval to pick the idle state.
+ */
+ data->predicted_us = min(data->predicted_us, expected_interval);
+
+ /*
+ * Use the performance multiplier and the user-configurable
+ * latency_req to determine the maximum exit latency.
+ */
+ interactivity_req = data->predicted_us / performance_multiplier(nr_iowaiters, cpu_load);
+ if (latency_req > interactivity_req)
+ latency_req = interactivity_req;
+
+ /*
* Find the idle state with the lowest power while satisfying
* our constraints.
*/