diff options
Diffstat (limited to 'drivers/cpuidle/governors/teo.c')
| -rw-r--r-- | drivers/cpuidle/governors/teo.c | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c index 987fc5f3997d..2cdc711679a5 100644 --- a/drivers/cpuidle/governors/teo.c +++ b/drivers/cpuidle/governors/teo.c @@ -397,13 +397,23 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, * the shallowest non-polling state and exit. */ if (drv->state_count < 3 && cpu_data->utilized) { - for (i = 0; i < drv->state_count; ++i) { - if (!dev->states_usage[i].disable && - !(drv->states[i].flags & CPUIDLE_FLAG_POLLING)) { - idx = i; - goto end; - } - } + /* The CPU is utilized, so assume a short idle duration. */ + duration_ns = teo_middle_of_bin(0, drv); + /* + * If state 0 is enabled and it is not a polling one, select it + * right away unless the scheduler tick has been stopped, in + * which case care needs to be taken to leave the CPU in a deep + * enough state in case it is not woken up any time soon after + * all. If state 1 is disabled, though, state 0 must be used + * anyway. + */ + if ((!idx && !(drv->states[0].flags & CPUIDLE_FLAG_POLLING) && + teo_time_ok(duration_ns)) || dev->states_usage[1].disable) + idx = 0; + else /* Assume that state 1 is not a polling one and use it. */ + idx = 1; + + goto end; } /* @@ -539,10 +549,20 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, /* * If the CPU is being utilized over the threshold, choose a shallower - * non-polling state to improve latency + * non-polling state to improve latency, unless the scheduler tick has + * been stopped already and the shallower state's target residency is + * not sufficiently large. */ - if (cpu_data->utilized) - idx = teo_find_shallower_state(drv, dev, idx, duration_ns, true); + if (cpu_data->utilized) { + s64 span_ns; + + i = teo_find_shallower_state(drv, dev, idx, duration_ns, true); + span_ns = teo_middle_of_bin(i, drv); + if (teo_time_ok(span_ns)) { + idx = i; + duration_ns = span_ns; + } + } end: /* |