diff options
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 106 |
1 files changed, 4 insertions, 102 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index fe343a0..bc580b6 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -28,13 +28,6 @@ #define MAX_INTERESTING 50000 #define STDDEV_THRESH 400 -/* 60 * 60 > STDDEV_THRESH * INTERVALS = 400 * 8 */ -#define MAX_DEVIATION 60 - -static DEFINE_PER_CPU(struct hrtimer, menu_hrtimer); -static DEFINE_PER_CPU(int, hrtimer_status); -/* menu hrtimer mode */ -enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT, MENU_HRTIMER_GENERAL}; /* * Concepts and ideas behind the menu governor @@ -116,13 +109,6 @@ enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT, MENU_HRTIMER_GENERAL}; * */ -/* - * The C-state residency is so long that is is worthwhile to exit - * from the shallow C-state and re-enter into a deeper C-state. - */ -static unsigned int perfect_cstate_ms __read_mostly = 30; -module_param(perfect_cstate_ms, uint, 0000); - struct menu_device { int last_state_idx; int needs_update; @@ -205,52 +191,17 @@ static u64 div_round64(u64 dividend, u32 divisor) return div_u64(dividend + (divisor / 2), divisor); } -/* Cancel the hrtimer if it is not triggered yet */ -void menu_hrtimer_cancel(void) -{ - int cpu = smp_processor_id(); - struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu); - - /* The timer is still not time out*/ - if (per_cpu(hrtimer_status, cpu)) { - hrtimer_cancel(hrtmr); - per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP; - } -} -EXPORT_SYMBOL_GPL(menu_hrtimer_cancel); - -/* Call back for hrtimer is triggered */ -static enum hrtimer_restart menu_hrtimer_notify(struct hrtimer *hrtimer) -{ - int cpu = smp_processor_id(); - struct menu_device *data = &per_cpu(menu_devices, cpu); - - /* In general case, the expected residency is much larger than - * deepest C-state target residency, but prediction logic still - * predicts a small predicted residency, so the prediction - * history is totally broken if the timer is triggered. - * So reset the correction factor. - */ - if (per_cpu(hrtimer_status, cpu) == MENU_HRTIMER_GENERAL) - data->correction_factor[data->bucket] = RESOLUTION * DECAY; - - per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP; - - return HRTIMER_NORESTART; -} - /* * Try detecting repeating patterns by keeping track of the last 8 * intervals, and checking if the standard deviation of that set * of points is below a threshold. If it is... then use the * average of these 8 points as the estimated value. */ -static u32 get_typical_interval(struct menu_device *data) +static void get_typical_interval(struct menu_device *data) { int i = 0, divisor = 0; uint64_t max = 0, avg = 0, stddev = 0; int64_t thresh = LLONG_MAX; /* Discard outliers above this value. */ - unsigned int ret = 0; again: @@ -291,16 +242,13 @@ again: if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3)) || stddev <= 20) { data->predicted_us = avg; - ret = 1; - return ret; + return; } else if ((divisor * 4) > INTERVALS * 3) { /* Exclude the max interval */ thresh = max - 1; goto again; } - - return ret; } /** @@ -315,9 +263,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) int i; int multiplier; struct timespec t; - int repeat = 0, low_predicted = 0; - int cpu = smp_processor_id(); - struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu); if (data->needs_update) { menu_update(drv, dev); @@ -352,7 +297,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket], RESOLUTION * DECAY); - repeat = get_typical_interval(data); + get_typical_interval(data); /* * We want to default to C1 (hlt), not to busy polling @@ -373,10 +318,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) if (s->disabled || su->disable) continue; - if (s->target_residency > data->predicted_us) { - low_predicted = 1; + if (s->target_residency > data->predicted_us) continue; - } if (s->exit_latency > latency_req) continue; if (s->exit_latency * multiplier > data->predicted_us) @@ -386,44 +329,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) data->exit_us = s->exit_latency; } - /* not deepest C-state chosen for low predicted residency */ - if (low_predicted) { - unsigned int timer_us = 0; - unsigned int perfect_us = 0; - - /* - * Set a timer to detect whether this sleep is much - * longer than repeat mode predicted. If the timer - * triggers, the code will evaluate whether to put - * the CPU into a deeper C-state. - * The timer is cancelled on CPU wakeup. - */ - timer_us = 2 * (data->predicted_us + MAX_DEVIATION); - - perfect_us = perfect_cstate_ms * 1000; - - if (repeat && (4 * timer_us < data->expected_us)) { - RCU_NONIDLE(hrtimer_start(hrtmr, - ns_to_ktime(1000 * timer_us), - HRTIMER_MODE_REL_PINNED)); - /* In repeat case, menu hrtimer is started */ - per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_REPEAT; - } else if (perfect_us < data->expected_us) { - /* - * The next timer is long. This could be because - * we did not make a useful prediction. - * In that case, it makes sense to re-enter - * into a deeper C-state after some time. - */ - RCU_NONIDLE(hrtimer_start(hrtmr, - ns_to_ktime(1000 * timer_us), - HRTIMER_MODE_REL_PINNED)); - /* In general case, menu hrtimer is started */ - per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_GENERAL; - } - - } - return data->last_state_idx; } @@ -514,9 +419,6 @@ static int menu_enable_device(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct menu_device *data = &per_cpu(menu_devices, dev->cpu); - struct hrtimer *t = &per_cpu(menu_hrtimer, dev->cpu); - hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - t->function = menu_hrtimer_notify; memset(data, 0, sizeof(struct menu_device)); |