diff options
author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-04-10 19:57:38 +0300 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-04-24 11:15:04 +0300 |
commit | bec55332c24eb671a1b6de17b38a70dee2472245 (patch) | |
tree | 77238ee4681e29080088ef307578f13327ea48ac /drivers/thermal | |
parent | fe036266504796c84adee28b64c347d3acf4206e (diff) | |
download | linux-bec55332c24eb671a1b6de17b38a70dee2472245.tar.xz |
thermal: gov_fair_share: Use .manage() callback instead of .throttle()
The Fair Share governor tries very hard to be stateless and so it
calls get_trip_level() from fair_share_throttle() every time, even
though the number produced by this function for all of the trips
during a given thermal zone update is actually the same. Since
get_trip_level() walks all of the trips in the thermal zone every
time it is called, doing this may generate quite a bit of completely
useless overhead.
For this reason, make the governor use the new .manage() callback
instead of .throttle() which allows it to call get_trip_level() just
once and use the value computed by it to handle all of the trips.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Diffstat (limited to 'drivers/thermal')
-rw-r--r-- | drivers/thermal/gov_fair_share.c | 37 |
1 files changed, 26 insertions, 11 deletions
diff --git a/drivers/thermal/gov_fair_share.c b/drivers/thermal/gov_fair_share.c index 6ef8cfde7749..ff81aeb5ac04 100644 --- a/drivers/thermal/gov_fair_share.c +++ b/drivers/thermal/gov_fair_share.c @@ -53,6 +53,7 @@ static long get_target_state(struct thermal_zone_device *tz, * fair_share_throttle - throttles devices associated with the given zone * @tz: thermal_zone_device * @trip: trip point + * @trip_level: number of trips crossed by the zone temperature * * Throttling Logic: This uses three parameters to calculate the new * throttle state of the cooling devices associated with the given zone. @@ -61,22 +62,19 @@ static long get_target_state(struct thermal_zone_device *tz, * P1. max_state: Maximum throttle state exposed by the cooling device. * P2. percentage[i]/100: * How 'effective' the 'i'th device is, in cooling the given zone. - * P3. cur_trip_level/max_no_of_trips: + * P3. trip_level/max_no_of_trips: * This describes the extent to which the devices should be throttled. * We do not want to throttle too much when we trip a lower temperature, * whereas the throttling is at full swing if we trip critical levels. - * (Heavily assumes the trip points are in ascending order) * new_state of cooling device = P3 * P2 * P1 */ -static int fair_share_throttle(struct thermal_zone_device *tz, - const struct thermal_trip *trip) +static void fair_share_throttle(struct thermal_zone_device *tz, + const struct thermal_trip *trip, + int trip_level) { struct thermal_instance *instance; int total_weight = 0; int total_instance = 0; - int cur_trip_level = get_trip_level(tz); - - lockdep_assert_held(&tz->lock); list_for_each_entry(instance, &tz->thermal_instances, tz_node) { if (instance->trip != trip) @@ -99,18 +97,35 @@ static int fair_share_throttle(struct thermal_zone_device *tz, percentage = (instance->weight * 100) / total_weight; instance->target = get_target_state(tz, cdev, percentage, - cur_trip_level); + trip_level); mutex_lock(&cdev->lock); __thermal_cdev_update(cdev); mutex_unlock(&cdev->lock); } +} + +static void fair_share_manage(struct thermal_zone_device *tz) +{ + int trip_level = get_trip_level(tz); + const struct thermal_trip_desc *td; + + lockdep_assert_held(&tz->lock); + + for_each_trip_desc(tz, td) { + const struct thermal_trip *trip = &td->trip; - return 0; + if (trip->temperature == THERMAL_TEMP_INVALID || + trip->type == THERMAL_TRIP_CRITICAL || + trip->type == THERMAL_TRIP_HOT) + continue; + + fair_share_throttle(tz, trip, trip_level); + } } static struct thermal_governor thermal_gov_fair_share = { - .name = "fair_share", - .throttle = fair_share_throttle, + .name = "fair_share", + .manage = fair_share_manage, }; THERMAL_GOVERNOR_DECLARE(thermal_gov_fair_share); |