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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2024-04-10 19:57:38 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2024-04-24 11:15:04 +0300
commitbec55332c24eb671a1b6de17b38a70dee2472245 (patch)
tree77238ee4681e29080088ef307578f13327ea48ac /drivers/thermal/gov_fair_share.c
parentfe036266504796c84adee28b64c347d3acf4206e (diff)
downloadlinux-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/gov_fair_share.c')
-rw-r--r--drivers/thermal/gov_fair_share.c37
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);