diff options
| -rw-r--r-- | drivers/cpuidle/governors/teo.c | 76 |
1 files changed, 13 insertions, 63 deletions
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c index 29743d78bc43..33610fb6a318 100644 --- a/drivers/cpuidle/governors/teo.c +++ b/drivers/cpuidle/governors/teo.c @@ -54,16 +54,12 @@ * shallower than the one whose bin is fallen into by the sleep length (these * situations are referred to as "intercepts" below). * - * In addition to the metrics described above, the governor counts recent - * intercepts (that is, intercepts that have occurred during the last - * %NR_RECENT invocations of it for the given CPU) for each bin. - * * In order to select an idle state for a CPU, the governor takes the following * steps (modulo the possible latency constraint that must be taken into account * too): * * 1. Find the deepest CPU idle state whose target residency does not exceed - * the current sleep length (the candidate idle state) and compute 3 sums as + * the current sleep length (the candidate idle state) and compute 2 sums as * follows: * * - The sum of the "hits" and "intercepts" metrics for the candidate state @@ -76,20 +72,15 @@ * idle long enough to avoid being intercepted if the sleep length had been * equal to the current one). * - * - The sum of the numbers of recent intercepts for all of the idle states - * shallower than the candidate one. - * - * 2. If the second sum is greater than the first one or the third sum is - * greater than %NR_RECENT / 2, the CPU is likely to wake up early, so look - * for an alternative idle state to select. + * 2. If the second sum is greater than the first one the CPU is likely to wake + * up early, so look for an alternative idle state to select. * * - Traverse the idle states shallower than the candidate one in the * descending order. * - * - For each of them compute the sum of the "intercepts" metrics and the sum - * of the numbers of recent intercepts over all of the idle states between - * it and the candidate one (including the former and excluding the - * latter). + * - 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 + * former and excluding the latter). * * - If each of these sums that needs to be taken into account (because the * check related to it has indicated that the CPU is likely to wake up @@ -116,22 +107,14 @@ #define PULSE 1024 #define DECAY_SHIFT 3 -/* - * Number of the most recent idle duration values to take into consideration for - * the detection of recent early wakeup patterns. - */ -#define NR_RECENT 9 - /** * struct teo_bin - Metrics used by the TEO cpuidle governor. * @intercepts: The "intercepts" metric. * @hits: The "hits" metric. - * @recent: The number of recent "intercepts". */ struct teo_bin { unsigned int intercepts; unsigned int hits; - unsigned int recent; }; /** @@ -140,8 +123,6 @@ struct teo_bin { * @sleep_length_ns: Time till the closest timer event (at the selection time). * @state_bins: Idle state data bins for this CPU. * @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. */ struct teo_cpu { @@ -149,8 +130,6 @@ struct teo_cpu { s64 sleep_length_ns; struct teo_bin state_bins[CPUIDLE_STATE_MAX]; unsigned int total; - int next_recent_idx; - int recent_idx[NR_RECENT]; unsigned int tick_hits; }; @@ -222,13 +201,6 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) } } - i = cpu_data->next_recent_idx++; - if (cpu_data->next_recent_idx >= NR_RECENT) - cpu_data->next_recent_idx = 0; - - if (cpu_data->recent_idx[i] >= 0) - 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 @@ -255,14 +227,10 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) * Otherwise, update the "intercepts" metric for the bin fallen into by * the measured idle duration. */ - if (idx_timer == idx_duration) { + if (idx_timer == idx_duration) cpu_data->state_bins[idx_timer].hits += PULSE; - cpu_data->recent_idx[i] = -1; - } else { + else cpu_data->state_bins[idx_duration].intercepts += PULSE; - cpu_data->state_bins[idx_duration].recent++; - cpu_data->recent_idx[i] = idx_duration; - } end: cpu_data->total += PULSE; @@ -315,13 +283,10 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, unsigned int tick_intercept_sum = 0; unsigned int idx_intercept_sum = 0; unsigned int intercept_sum = 0; - unsigned int idx_recent_sum = 0; - unsigned int recent_sum = 0; unsigned int idx_hit_sum = 0; unsigned int hit_sum = 0; int constraint_idx = 0; int idx0 = 0, idx = -1; - bool alt_intercepts, alt_recent; s64 duration_ns; int i; @@ -357,7 +322,6 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, */ intercept_sum += prev_bin->intercepts; hit_sum += prev_bin->hits; - recent_sum += prev_bin->recent; if (dev->states_usage[i].disable) continue; @@ -373,7 +337,6 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, /* Save the sums for the current state. */ idx_intercept_sum = intercept_sum; idx_hit_sum = hit_sum; - idx_recent_sum = recent_sum; } /* Avoid unnecessary overhead. */ @@ -398,37 +361,28 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, * If the sum of the intercepts metric for all of the idle states * shallower than the current candidate one (idx) is greater than the * sum of the intercepts and hits metrics for the candidate state and - * all of the deeper states, or the sum of the numbers of recent - * intercepts over all of the states shallower than the candidate one - * is greater than a half of the number of recent events taken into - * account, a shallower idle state is likely to be a better choice. + * all of the deeper states a shallower idle state is likely to be a + * better choice. */ - alt_intercepts = 2 * idx_intercept_sum > cpu_data->total - idx_hit_sum; - alt_recent = idx_recent_sum > NR_RECENT / 2; - if (alt_recent || alt_intercepts) { + if (2 * idx_intercept_sum > cpu_data->total - idx_hit_sum) { int first_suitable_idx = idx; /* * Look for the deepest idle state whose target residency had * not exceeded the idle duration in over a half of the relevant - * cases (both with respect to intercepts overall and with - * respect to the recent intercepts only) in the past. + * cases in the past. * * Take the possible duration limitation present if the tick * has been stopped already into account. */ intercept_sum = 0; - recent_sum = 0; for (i = idx - 1; i >= 0; i--) { struct teo_bin *bin = &cpu_data->state_bins[i]; intercept_sum += bin->intercepts; - recent_sum += bin->recent; - if ((!alt_recent || 2 * recent_sum > idx_recent_sum) && - (!alt_intercepts || - 2 * intercept_sum > idx_intercept_sum)) { + if (2 * intercept_sum > idx_intercept_sum) { /* * Use the current state unless it is too * shallow or disabled, in which case take the @@ -564,13 +518,9 @@ static int teo_enable_device(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu); - int i; memset(cpu_data, 0, sizeof(*cpu_data)); - for (i = 0; i < NR_RECENT; i++) - cpu_data->recent_idx[i] = -1; - return 0; } |