diff options
Diffstat (limited to 'drivers/cpuidle/governors')
| -rw-r--r-- | drivers/cpuidle/governors/teo.c | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c index 8248492cad3a..70846b669255 100644 --- a/drivers/cpuidle/governors/teo.c +++ b/drivers/cpuidle/governors/teo.c @@ -192,6 +192,7 @@ struct teo_bin { * @total: Grand total of the "intercepts" and "hits" metrics for all bins. * @next_recent_idx: Index of the next @recent_idx entry to update. * @recent_idx: Indices of bins corresponding to recent "intercepts". + * @tick_hits: Number of "hits" after TICK_NSEC. * @util_threshold: Threshold above which the CPU is considered utilized */ struct teo_cpu { @@ -201,6 +202,7 @@ struct teo_cpu { unsigned int total; int next_recent_idx; int recent_idx[NR_RECENT]; + unsigned int tick_hits; unsigned long util_threshold; }; @@ -232,6 +234,7 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu); int i, idx_timer = 0, idx_duration = 0; + s64 target_residency_ns; u64 measured_ns; if (cpu_data->time_span_ns >= cpu_data->sleep_length_ns) { @@ -272,7 +275,6 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) * fall into. */ for (i = 0; i < drv->state_count; i++) { - s64 target_residency_ns = drv->states[i].target_residency_ns; struct teo_bin *bin = &cpu_data->state_bins[i]; bin->hits -= bin->hits >> DECAY_SHIFT; @@ -280,6 +282,8 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) cpu_data->total += bin->hits + bin->intercepts; + target_residency_ns = drv->states[i].target_residency_ns; + if (target_residency_ns <= cpu_data->sleep_length_ns) { idx_timer = i; if (target_residency_ns <= measured_ns) @@ -295,6 +299,26 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) cpu_data->state_bins[cpu_data->recent_idx[i]].recent--; /* + * If the deepest state's target residency is below the tick length, + * make a record of it to help teo_select() decide whether or not + * to stop the tick. This effectively adds an extra hits-only bin + * beyond the last state-related one. + */ + if (target_residency_ns < TICK_NSEC) { + cpu_data->tick_hits -= cpu_data->tick_hits >> DECAY_SHIFT; + + cpu_data->total += cpu_data->tick_hits; + + if (TICK_NSEC <= cpu_data->sleep_length_ns) { + idx_timer = drv->state_count; + if (TICK_NSEC <= measured_ns) { + cpu_data->tick_hits += PULSE; + goto end; + } + } + } + + /* * If the measured idle duration falls into the same bin as the sleep * length, this is a "hit", so update the "hits" metric for that bin. * Otherwise, update the "intercepts" metric for the bin fallen into by @@ -309,6 +333,7 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) cpu_data->recent_idx[i] = idx_duration; } +end: cpu_data->total += PULSE; } @@ -356,6 +381,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu); s64 latency_req = cpuidle_governor_latency_req(dev->cpu); ktime_t delta_tick = TICK_NSEC / 2; + unsigned int tick_intercept_sum = 0; unsigned int idx_intercept_sum = 0; unsigned int intercept_sum = 0; unsigned int idx_recent_sum = 0; @@ -429,6 +455,8 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, hit_sum += prev_bin->hits; recent_sum += prev_bin->recent; + tick_intercept_sum = intercept_sum; + if (dev->states_usage[i].disable) continue; @@ -461,6 +489,8 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, goto end; } + tick_intercept_sum += cpu_data->state_bins[drv->state_count-1].intercepts; + /* * If the sum of the intercepts metric for all of the idle states * shallower than the current candidate one (idx) is greater than the @@ -577,6 +607,15 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, idx = i; } + /* + * If the selected state's target residency is below the tick length + * and intercepts occurring before the tick length are the majority of + * total wakeup events, do not stop the tick. + */ + if (drv->states[idx].target_residency_ns < TICK_NSEC && + tick_intercept_sum > cpu_data->total / 2 + cpu_data->total / 8) + duration_ns = TICK_NSEC / 2; + end: /* * Allow the tick to be stopped unless the selected state is a polling |