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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-10-24 23:12:55 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-10-24 23:12:55 +0200
commit2c2a83d329b89c74063580bad95bcb595dc09535 (patch)
tree75603538c7e5527fa351ec49890771a08acbc1be /drivers/cpuidle
parent31d851407f90076c58291fb5eadc82c1dd613cee (diff)
parent159e48560f51d9c2aa02d762a18cd24f7868ab27 (diff)
downloadlinux-2c2a83d329b89c74063580bad95bcb595dc09535.tar.bz2
Merge back earlier cpuidle material for v5.5.
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/governors/teo.c78
1 files changed, 59 insertions, 19 deletions
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c
index b5a0e498f798..b9b9156618e6 100644
--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -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.