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Merge back earlier cpuidle material for v5.5.

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This commit is contained in:
Rafael J. Wysocki 2019-10-24 23:12:55 +02:00
commit 2c2a83d329
1 changed files with 59 additions and 19 deletions
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78
drivers/cpuidle/governors/teo.c
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@ -233,7 +233,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
{
struct teo_cpu *cpu_data = per_cpu_ptr(&teo_cpus, dev->cpu);
int latency_req = cpuidle_governor_latency_req(dev->cpu);
unsigned int duration_us, count;
unsigned int duration_us, hits, misses, early_hits;
int max_early_idx, constraint_idx, idx, i;
ktime_t delta_tick;
@ -247,7 +247,9 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
cpu_data->sleep_length_ns = tick_nohz_get_sleep_length(&delta_tick);
duration_us = ktime_to_us(cpu_data->sleep_length_ns);
count = 0;
hits = 0;
misses = 0;
early_hits = 0;
max_early_idx = -1;
constraint_idx = drv->state_count;
idx = -1;
@ -258,23 +260,61 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
if (s->disabled || su->disable) {
/*
* If the "early hits" metric of a disabled state is
* greater than the current maximum, it should be taken
* into account, because it would be a mistake to select
* a deeper state with lower "early hits" metric. The
* index cannot be changed to point to it, however, so
* just increase the max count alone and let the index
* still point to a shallower idle state.
* Ignore disabled states with target residencies beyond
* the anticipated idle duration.
*/
if (max_early_idx >= 0 &&
count < cpu_data->states[i].early_hits)
count = cpu_data->states[i].early_hits;
if (s->target_residency > duration_us)
continue;
/*
* This state is disabled, so the range of idle duration
* values corresponding to it is covered by the current
* candidate state, but still the "hits" and "misses"
* metrics of the disabled state need to be used to
* decide whether or not the state covering the range in
* question is good enough.
*/
hits = cpu_data->states[i].hits;
misses = cpu_data->states[i].misses;
if (early_hits >= cpu_data->states[i].early_hits ||
idx < 0)
continue;
/*
* If the current candidate state has been the one with
* the maximum "early hits" metric so far, the "early
* hits" metric of the disabled state replaces the
* current "early hits" count to avoid selecting a
* deeper state with lower "early hits" metric.
*/
if (max_early_idx == idx) {
early_hits = cpu_data->states[i].early_hits;
continue;
}
/*
* The current candidate state is closer to the disabled
* one than the current maximum "early hits" state, so
* replace the latter with it, but in case the maximum
* "early hits" state index has not been set so far,
* check if the current candidate state is not too
* shallow for that role.
*/
if (!(tick_nohz_tick_stopped() &&
drv->states[idx].target_residency < TICK_USEC)) {
early_hits = cpu_data->states[i].early_hits;
max_early_idx = idx;
}
continue;
}
if (idx < 0)
if (idx < 0) {
idx = i; /* first enabled state */
hits = cpu_data->states[i].hits;
misses = cpu_data->states[i].misses;
}
if (s->target_residency > duration_us)
break;
@ -283,11 +323,13 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
constraint_idx = i;
idx = i;
hits = cpu_data->states[i].hits;
misses = cpu_data->states[i].misses;
if (count < cpu_data->states[i].early_hits &&
if (early_hits < cpu_data->states[i].early_hits &&
!(tick_nohz_tick_stopped() &&
drv->states[i].target_residency < TICK_USEC)) {
count = cpu_data->states[i].early_hits;
early_hits = cpu_data->states[i].early_hits;
max_early_idx = i;
}
}
@ -300,8 +342,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
* "early hits" metric, but if that cannot be determined, just use the
* state selected so far.
*/
if (cpu_data->states[idx].hits <= cpu_data->states[idx].misses &&
max_early_idx >= 0) {
if (hits <= misses && max_early_idx >= 0) {
idx = max_early_idx;
duration_us = drv->states[idx].target_residency;
}
@ -316,10 +357,9 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
if (idx < 0) {
idx = 0; /* No states enabled. Must use 0. */
} else if (idx > 0) {
unsigned int count = 0;
u64 sum = 0;
count = 0;
/*
* Count and sum the most recent idle duration values less than
* the current expected idle duration value.