diff options
| -rw-r--r-- | Documentation/cpuidle/sysfs.txt | 10 | ||||
| -rw-r--r-- | drivers/cpuidle/governors/ladder.c | 4 |
2 files changed, 12 insertions, 2 deletions
diff --git a/Documentation/cpuidle/sysfs.txt b/Documentation/cpuidle/sysfs.txt index 9d28a3406e74..b6f44f490ed7 100644 --- a/Documentation/cpuidle/sysfs.txt +++ b/Documentation/cpuidle/sysfs.txt @@ -76,9 +76,17 @@ total 0 * desc : Small description about the idle state (string) -* disable : Option to disable this idle state (bool) +* disable : Option to disable this idle state (bool) -> see note below * latency : Latency to exit out of this idle state (in microseconds) * name : Name of the idle state (string) * power : Power consumed while in this idle state (in milliwatts) * time : Total time spent in this idle state (in microseconds) * usage : Number of times this state was entered (count) + +Note: +The behavior and the effect of the disable variable depends on the +implementation of a particular governor. In the ladder governor, for +example, it is not coherent, i.e. if one is disabling a light state, +then all deeper states are disabled as well, but the disable variable +does not reflect it. Likewise, if one enables a deep state but a lighter +state still is disabled, then this has no effect. diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index b6a09ea859b1..2aef26c520bb 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -88,6 +88,7 @@ static int ladder_select_state(struct cpuidle_driver *drv, /* consider promotion */ if (last_idx < drv->state_count - 1 && + !dev->states_usage[last_idx + 1].disable && last_residency > last_state->threshold.promotion_time && drv->states[last_idx + 1].exit_latency <= latency_req) { last_state->stats.promotion_count++; @@ -100,7 +101,8 @@ static int ladder_select_state(struct cpuidle_driver *drv, /* consider demotion */ if (last_idx > CPUIDLE_DRIVER_STATE_START && - drv->states[last_idx].exit_latency > latency_req) { + (dev->states_usage[last_idx].disable || + drv->states[last_idx].exit_latency > latency_req)) { int i; for (i = last_idx - 1; i > CPUIDLE_DRIVER_STATE_START; i--) { |