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path: root/drivers/cpuidle/governors/teo.c
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Diffstat (limited to 'drivers/cpuidle/governors/teo.c')
-rw-r--r--drivers/cpuidle/governors/teo.c54
1 files changed, 30 insertions, 24 deletions
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c
index 6deaaf5f05b5..ac4bb27d69b0 100644
--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -100,8 +100,8 @@ struct teo_idle_state {
* @intervals: Saved idle duration values.
*/
struct teo_cpu {
- u64 time_span_ns;
- u64 sleep_length_ns;
+ s64 time_span_ns;
+ s64 sleep_length_ns;
struct teo_idle_state states[CPUIDLE_STATE_MAX];
int interval_idx;
u64 intervals[INTERVALS];
@@ -117,7 +117,8 @@ static DEFINE_PER_CPU(struct teo_cpu, teo_cpus);
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_hit = -1, idx_timer = -1;
+ int i, idx_hit = 0, idx_timer = 0;
+ unsigned int hits, misses;
u64 measured_ns;
if (cpu_data->time_span_ns >= cpu_data->sleep_length_ns) {
@@ -174,25 +175,22 @@ static void teo_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
* also increase the "early hits" metric for the state that actually
* matches the measured idle duration.
*/
- if (idx_timer >= 0) {
- unsigned int hits = cpu_data->states[idx_timer].hits;
- unsigned int misses = cpu_data->states[idx_timer].misses;
-
- hits -= hits >> DECAY_SHIFT;
- misses -= misses >> DECAY_SHIFT;
-
- if (idx_timer > idx_hit) {
- misses += PULSE;
- if (idx_hit >= 0)
- cpu_data->states[idx_hit].early_hits += PULSE;
- } else {
- hits += PULSE;
- }
+ hits = cpu_data->states[idx_timer].hits;
+ hits -= hits >> DECAY_SHIFT;
+
+ misses = cpu_data->states[idx_timer].misses;
+ misses -= misses >> DECAY_SHIFT;
- cpu_data->states[idx_timer].misses = misses;
- cpu_data->states[idx_timer].hits = hits;
+ if (idx_timer == idx_hit) {
+ hits += PULSE;
+ } else {
+ misses += PULSE;
+ cpu_data->states[idx_hit].early_hits += PULSE;
}
+ cpu_data->states[idx_timer].misses = misses;
+ cpu_data->states[idx_timer].hits = hits;
+
/*
* Save idle duration values corresponding to non-timer wakeups for
* pattern detection.
@@ -216,7 +214,7 @@ static bool teo_time_ok(u64 interval_ns)
*/
static int teo_find_shallower_state(struct cpuidle_driver *drv,
struct cpuidle_device *dev, int state_idx,
- u64 duration_ns)
+ s64 duration_ns)
{
int i;
@@ -242,10 +240,10 @@ 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);
- u64 duration_ns;
+ int max_early_idx, prev_max_early_idx, constraint_idx, idx0, idx, i;
unsigned int hits, misses, early_hits;
- int max_early_idx, prev_max_early_idx, constraint_idx, idx, i;
ktime_t delta_tick;
+ s64 duration_ns;
if (dev->last_state_idx >= 0) {
teo_update(drv, dev);
@@ -264,6 +262,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
prev_max_early_idx = -1;
constraint_idx = drv->state_count;
idx = -1;
+ idx0 = idx;
for (i = 0; i < drv->state_count; i++) {
struct cpuidle_state *s = &drv->states[i];
@@ -324,6 +323,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
idx = i; /* first enabled state */
hits = cpu_data->states[i].hits;
misses = cpu_data->states[i].misses;
+ idx0 = i;
}
if (s->target_residency_ns > duration_ns)
@@ -376,11 +376,16 @@ 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) {
+ } else if (idx > idx0) {
unsigned int count = 0;
u64 sum = 0;
/*
+ * The target residencies of at least two different enabled idle
+ * states are less than or equal to the current expected idle
+ * duration. Try to refine the selection using the most recent
+ * measured idle duration values.
+ *
* Count and sum the most recent idle duration values less than
* the current expected idle duration value.
*/
@@ -428,7 +433,8 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
* till the closest timer including the tick, try to correct
* that.
*/
- if (idx > 0 && drv->states[idx].target_residency_ns > delta_tick)
+ if (idx > idx0 &&
+ drv->states[idx].target_residency_ns > delta_tick)
idx = teo_find_shallower_state(drv, dev, idx, delta_tick);
}