diff options
Diffstat (limited to 'drivers/cpuidle/governors/menu.c')
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 65 |
1 files changed, 38 insertions, 27 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index c4922684f305..b96e3da0fedd 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -19,6 +19,8 @@ #include <linux/sched/stat.h> #include <linux/math64.h> +#include "gov.h" + #define BUCKETS 12 #define INTERVAL_SHIFT 3 #define INTERVALS (1UL << INTERVAL_SHIFT) @@ -166,8 +168,7 @@ 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 unsigned int get_typical_interval(struct menu_device *data, - unsigned int predicted_us) +static unsigned int get_typical_interval(struct menu_device *data) { int i, divisor; unsigned int min, max, thresh, avg; @@ -195,11 +196,7 @@ again: } } - /* - * If the result of the computation is going to be discarded anyway, - * avoid the computation altogether. - */ - if (min >= predicted_us) + if (!max) return UINT_MAX; if (divisor == INTERVALS) @@ -267,7 +264,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, { struct menu_device *data = this_cpu_ptr(&menu_devices); s64 latency_req = cpuidle_governor_latency_req(dev->cpu); - unsigned int predicted_us; u64 predicted_ns; u64 interactivity_req; unsigned int nr_iowaiters; @@ -279,16 +275,41 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, data->needs_update = 0; } - /* determine the expected residency time, round up */ - delta = tick_nohz_get_sleep_length(&delta_tick); - if (unlikely(delta < 0)) { - delta = 0; - delta_tick = 0; - } - data->next_timer_ns = delta; - nr_iowaiters = nr_iowait_cpu(dev->cpu); - data->bucket = which_bucket(data->next_timer_ns, nr_iowaiters); + + /* Find the shortest expected idle interval. */ + predicted_ns = get_typical_interval(data) * NSEC_PER_USEC; + if (predicted_ns > RESIDENCY_THRESHOLD_NS) { + unsigned int timer_us; + + /* Determine the time till the closest timer. */ + delta = tick_nohz_get_sleep_length(&delta_tick); + if (unlikely(delta < 0)) { + delta = 0; + delta_tick = 0; + } + + data->next_timer_ns = delta; + data->bucket = which_bucket(data->next_timer_ns, nr_iowaiters); + + /* Round up the result for half microseconds. */ + timer_us = div_u64((RESOLUTION * DECAY * NSEC_PER_USEC) / 2 + + data->next_timer_ns * + data->correction_factor[data->bucket], + RESOLUTION * DECAY * NSEC_PER_USEC); + /* Use the lowest expected idle interval to pick the idle state. */ + predicted_ns = min((u64)timer_us * NSEC_PER_USEC, predicted_ns); + } else { + /* + * Because the next timer event is not going to be determined + * in this case, assume that without the tick the closest timer + * will be in distant future and that the closest tick will occur + * after 1/2 of the tick period. + */ + data->next_timer_ns = KTIME_MAX; + delta_tick = TICK_NSEC / 2; + data->bucket = which_bucket(KTIME_MAX, nr_iowaiters); + } if (unlikely(drv->state_count <= 1 || latency_req == 0) || ((data->next_timer_ns < drv->states[1].target_residency_ns || @@ -303,16 +324,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, return 0; } - /* Round up the result for half microseconds. */ - predicted_us = div_u64(data->next_timer_ns * - data->correction_factor[data->bucket] + - (RESOLUTION * DECAY * NSEC_PER_USEC) / 2, - RESOLUTION * DECAY * NSEC_PER_USEC); - /* Use the lowest expected idle interval to pick the idle state. */ - predicted_ns = (u64)min(predicted_us, - get_typical_interval(data, predicted_us)) * - NSEC_PER_USEC; - if (tick_nohz_tick_stopped()) { /* * If the tick is already stopped, the cost of possible short |