| Message ID | 1355493455-30665-3-git-send-email-daniel.lezcano@linaro.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
Hi Daniel, On 12/14/2012 02:57 PM, Daniel Lezcano wrote: > As the power is backward sorted in the states array and we are looking for > the state consuming the little power as possible, instead of looking from > the beginning of the array, we look from the end. That should save us some > iterations in the loop each time we select a state at idle time. > > Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> > --- > drivers/cpuidle/governors/menu.c | 12 ++++++------ > 1 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c > index fe343a0..05b8998 100644 > --- a/drivers/cpuidle/governors/menu.c > +++ b/drivers/cpuidle/governors/menu.c > @@ -367,24 +367,24 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) > * Find the idle state with the lowest power while satisfying > * our constraints. > */ > - for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { > + for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--) { > struct cpuidle_state *s = &drv->states[i]; > struct cpuidle_state_usage *su = &dev->states_usage[i]; > > if (s->disabled || su->disable) > continue; > - if (s->target_residency > data->predicted_us) { > - low_predicted = 1; > - continue; > - } > if (s->exit_latency > latency_req) > continue; > + if (s->target_residency > data->predicted_us) > + continue; > if (s->exit_latency * multiplier > data->predicted_us) > continue; > > + low_predicted = i - CPUIDLE_DRIVER_STATE_START; You are altering the semantics of low_predicted, which is supposed to be non-zero when the deepest C-state has not been chosen because its target residency is more than the predicted residency. It seems to me that the if block where target_residency is compared with the predicted residency should be left as is. > data->last_state_idx = i; > data->exit_us = s->exit_latency; > - } > + break; > + } > > /* not deepest C-state chosen for low predicted residency */ > if (low_predicted) { -- Francesco -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
*Ping!* Happy New Year everyone. Is there any update on this? I think Francesco already pointed out how to solve the last remaining issue with this, so I hope we can now resubmit these patches and finally get them merged. Daniel?-- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index fe343a0..05b8998 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -367,24 +367,24 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) * Find the idle state with the lowest power while satisfying * our constraints. */ - for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { + for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--) { struct cpuidle_state *s = &drv->states[i]; struct cpuidle_state_usage *su = &dev->states_usage[i]; if (s->disabled || su->disable) continue; - if (s->target_residency > data->predicted_us) { - low_predicted = 1; - continue; - } if (s->exit_latency > latency_req) continue; + if (s->target_residency > data->predicted_us) + continue; if (s->exit_latency * multiplier > data->predicted_us) continue; + low_predicted = i - CPUIDLE_DRIVER_STATE_START; data->last_state_idx = i; data->exit_us = s->exit_latency; - } + break; + } /* not deepest C-state chosen for low predicted residency */ if (low_predicted) {
As the power is backward sorted in the states array and we are looking for the state consuming the little power as possible, instead of looking from the beginning of the array, we look from the end. That should save us some iterations in the loop each time we select a state at idle time. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> --- drivers/cpuidle/governors/menu.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-)