diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c index 34b769b37a86..80f3ba942a06 100644 --- a/drivers/cpuidle/governors/teo.c +++ b/drivers/cpuidle/governors/teo.c @@ -74,12 +74,17 @@ * than the candidate one (it represents the cases in which the CPU was * likely woken up by a non-timer wakeup source). * + * Also find the idle state with the maximum intercepts metric (if there are + * multiple states with the maximum intercepts metric, choose the one with + * the highest index). + * * 2. If the second sum computed in step 1 is greater than a half of the sum of * both metrics for the candidate state bin and all subsequent bins (if any), * a shallower idle state is likely to be more suitable, so look for it. * * - Traverse the enabled idle states shallower than the candidate one in the - * descending order. + * descending order, starting at the state with the maximum intercepts + * metric found in step 1. * * - For each of them compute the sum of the "intercepts" metrics over all * of the idle states between it and the candidate one (including the @@ -308,8 +313,10 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, ktime_t delta_tick = TICK_NSEC / 2; unsigned int idx_intercept_sum = 0; unsigned int intercept_sum = 0; + unsigned int intercept_max = 0; unsigned int idx_hit_sum = 0; unsigned int hit_sum = 0; + int intercept_max_idx = -1; int constraint_idx = 0; int idx0 = 0, idx = -1; s64 duration_ns; @@ -340,17 +347,32 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, if (!dev->states_usage[0].disable) idx = 0; - /* Compute the sums of metrics for early wakeup pattern detection. */ + /* + * Compute the sums of metrics for early wakeup pattern detection and + * look for the state bin with the maximum intercepts metric below the + * deepest enabled one (if there are multiple states with the maximum + * intercepts metric, choose the one with the highest index). + */ for (i = 1; i < drv->state_count; i++) { struct teo_bin *prev_bin = &cpu_data->state_bins[i-1]; + unsigned int prev_intercepts = prev_bin->intercepts; struct cpuidle_state *s = &drv->states[i]; /* * Update the sums of idle state metrics for all of the states * shallower than the current one. */ - intercept_sum += prev_bin->intercepts; hit_sum += prev_bin->hits; + intercept_sum += prev_intercepts; + /* + * Check if this is the bin with the maximum number of + * intercepts so far and in that case update the index of + * the state with the maximum intercepts metric. + */ + if (prev_intercepts >= intercept_max) { + intercept_max = prev_intercepts; + intercept_max_idx = i - 1; + } if (dev->states_usage[i].disable) continue; @@ -414,9 +436,22 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, } /* - * Look for the deepest idle state whose target residency had - * not exceeded the idle duration in over a half of the relevant - * cases in the past. + * If the minimum state index is greater than or equal to the + * index of the state with the maximum intercepts metric and + * the corresponding state is enabled, there is no need to look + * at the deeper states. + */ + if (min_idx >= intercept_max_idx && + !dev->states_usage[min_idx].disable) { + idx = min_idx; + goto constraint; + } + + /* + * Look for the deepest enabled idle state, at most as deep as + * the one with the maximum intercepts metric, whose target + * residency had not been greater than the idle duration in over + * a half of the relevant cases in the past. * * Take the possible duration limitation present if the tick * has been stopped already into account. @@ -428,7 +463,8 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, continue; idx = i; - if (2 * intercept_sum > idx_intercept_sum) + if (2 * intercept_sum > idx_intercept_sum && + i <= intercept_max_idx) break; } }