diff options
Diffstat (limited to 'drivers/cpuidle/governors/teo.c')
| -rw-r--r-- | drivers/cpuidle/governors/teo.c | 60 |
1 files changed, 26 insertions, 34 deletions
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c index 7d05efdbd3c6..b5a0e498f798 100644 --- a/drivers/cpuidle/governors/teo.c +++ b/drivers/cpuidle/governors/teo.c @@ -96,7 +96,6 @@ struct teo_idle_state { * @time_span_ns: Time between idle state selection and post-wakeup update. * @sleep_length_ns: Time till the closest timer event (at the selection time). * @states: Idle states data corresponding to this CPU. - * @last_state: Idle state entered by the CPU last time. * @interval_idx: Index of the most recent saved idle interval. * @intervals: Saved idle duration values. */ @@ -104,7 +103,6 @@ struct teo_cpu { u64 time_span_ns; u64 sleep_length_ns; struct teo_idle_state states[CPUIDLE_STATE_MAX]; - int last_state; int interval_idx; unsigned int intervals[INTERVALS]; }; @@ -125,12 +123,15 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) if (cpu_data->time_span_ns >= cpu_data->sleep_length_ns) { /* - * One of the safety nets has triggered or this was a timer - * wakeup (or equivalent). + * One of the safety nets has triggered or the wakeup was close + * enough to the closest timer event expected at the idle state + * selection time to be discarded. */ - measured_us = sleep_length_us; + measured_us = UINT_MAX; } else { - unsigned int lat = drv->states[cpu_data->last_state].exit_latency; + unsigned int lat; + + lat = drv->states[dev->last_state_idx].exit_latency; measured_us = ktime_to_us(cpu_data->time_span_ns); /* @@ -189,15 +190,6 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) } /* - * If the total time span between idle state selection and the "reflect" - * callback is greater than or equal to the sleep length determined at - * the idle state selection time, the wakeup is likely to be due to a - * timer event. - */ - if (cpu_data->time_span_ns >= cpu_data->sleep_length_ns) - measured_us = UINT_MAX; - - /* * Save idle duration values corresponding to non-timer wakeups for * pattern detection. */ @@ -242,12 +234,12 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu); int latency_req = cpuidle_governor_latency_req(dev->cpu); unsigned int duration_us, count; - int max_early_idx, idx, i; + int max_early_idx, constraint_idx, idx, i; ktime_t delta_tick; - if (cpu_data->last_state >= 0) { + if (dev->last_state_idx >= 0) { teo_update(drv, dev); - cpu_data->last_state = -1; + dev->last_state_idx = -1; } cpu_data->time_span_ns = local_clock(); @@ -257,6 +249,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, count = 0; max_early_idx = -1; + constraint_idx = drv->state_count; idx = -1; for (i = 0; i < drv->state_count; i++) { @@ -286,16 +279,8 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, if (s->target_residency > duration_us) break; - if (s->exit_latency > latency_req) { - /* - * If we break out of the loop for latency reasons, use - * the target residency of the selected state as the - * expected idle duration to avoid stopping the tick - * as long as that target residency is low enough. - */ - duration_us = drv->states[idx].target_residency; - goto refine; - } + if (s->exit_latency > latency_req && constraint_idx > i) + constraint_idx = i; idx = i; @@ -321,7 +306,13 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, duration_us = drv->states[idx].target_residency; } -refine: + /* + * If there is a latency constraint, it may be necessary to use a + * shallower idle state than the one selected so far. + */ + if (constraint_idx < idx) + idx = constraint_idx; + if (idx < 0) { idx = 0; /* No states enabled. Must use 0. */ } else if (idx > 0) { @@ -331,13 +322,12 @@ refine: /* * Count and sum the most recent idle duration values less than - * the target residency of the state selected so far, find the - * max. + * the current expected idle duration value. */ for (i = 0; i < INTERVALS; i++) { unsigned int val = cpu_data->intervals[i]; - if (val >= drv->states[idx].target_residency) + if (val >= duration_us) continue; count++; @@ -356,8 +346,10 @@ refine: * would be too shallow. */ if (!(tick_nohz_tick_stopped() && avg_us < TICK_USEC)) { - idx = teo_find_shallower_state(drv, dev, idx, avg_us); duration_us = avg_us; + if (drv->states[idx].target_residency > avg_us) + idx = teo_find_shallower_state(drv, dev, + idx, avg_us); } } } @@ -394,7 +386,7 @@ static void teo_reflect(struct cpuidle_device *dev, int state) { struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu); - cpu_data->last_state = state; + dev->last_state_idx = state; /* * If the wakeup was not "natural", but triggered by one of the safety * nets, assume that the CPU might have been idle for the entire sleep |