Re: [PATCH v1 08/16] thermal: gov_step_wise: Use .manage() callback instead of .throttle()

Lukasz Luba
2024-04-19T17:19:55Z

On 4/10/24 17:13, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Make the Step-Wise governor use the new .manage() callback instead of
> .throttle().
>
> Even though using .throttle() is not particularly problematic for the
> Step-Wise governor, using .manage() instead still allows it to reduce
> overhead by updating all of the colling devices once after setting

s/colling/cooling/

> target values for all of the thermal instances.

Make sense, good observation, it's pointless to call the
thermal_cdev_update() in each trip point throttle() invocation.

>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/thermal/gov_step_wise.c | 39 +++++++++++++++++++++------------------
> 1 file changed, 21 insertions(+), 18 deletions(-)
>
> Index: linux-pm/drivers/thermal/gov_step_wise.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/gov_step_wise.c
> +++ linux-pm/drivers/thermal/gov_step_wise.c
> @@ -109,34 +109,37 @@ static void thermal_zone_trip_update(str
> }
> }
>
> -/**
> - * step_wise_throttle - throttles devices associated with the given zone
> - * @tz: thermal_zone_device
> - * @trip: trip point
> - *
> - * Throttling Logic: This uses the trend of the thermal zone to throttle.
> - * If the thermal zone is 'heating up' this throttles all the cooling
> - * devices associated with the zone and its particular trip point, by one
> - * step. If the zone is 'cooling down' it brings back the performance of
> - * the devices by one step.
> - */
> -static int step_wise_throttle(struct thermal_zone_device *tz,
> - const struct thermal_trip *trip)
> +static void step_wise_manage(struct thermal_zone_device *tz)
> {
> + const struct thermal_trip_desc *td;
> struct thermal_instance *instance;
>
> lockdep_assert_held(&tz->lock);
>
> - thermal_zone_trip_update(tz, trip);
> + /*
> + * Throttling Logic: Use the trend of the thermal zone to throttle.
> + * If the thermal zone is 'heating up', throttle all of the cooling
> + * devices associated with each trip point by one step. If the zone
> + * is 'cooling down', it brings back the performance of the devices
> + * by one step.
> + */
> + for_each_trip_desc(tz, td) {
> + const struct thermal_trip *trip = &td->trip;
> +
> + if (trip->temperature == THERMAL_TEMP_INVALID ||
> + trip->type == THERMAL_TRIP_CRITICAL ||
> + trip->type == THERMAL_TRIP_HOT)
> + continue;
> +
> + thermal_zone_trip_update(tz, trip);
> + }
>
> list_for_each_entry(instance, &tz->thermal_instances, tz_node)
> thermal_cdev_update(instance->cdev);
> -
> - return 0;
> }
>
> static struct thermal_governor thermal_gov_step_wise = {
> - .name = "step_wise",
> - .throttle = step_wise_throttle,
> + .name = "step_wise",
> + .manage = step_wise_manage,
> };
> THERMAL_GOVERNOR_DECLARE(thermal_gov_step_wise);
>
>
>

LGTM w/ that 'cooling' spelling fixed.

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>