On Wed, Sep 27, 2023 at 5:00 PM Daniel Lezcano
<daniel.lezcano@xxxxxxxxxx> wrote:
On 21/09/2023 19:54, Rafael J. Wysocki wrote:
From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Make get_trip_level() access the thermal zone's trip table directly
instead of using __thermal_zone_get_trip() which adds overhead related
to the unnecessary bounds checking and copying the trip point data.
Also rearrange the code in it to make it somewhat easier to follow.
The general functionality is not expected to be changed.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/thermal/gov_fair_share.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
Index: linux-pm/drivers/thermal/gov_fair_share.c
===================================================================
--- linux-pm.orig/drivers/thermal/gov_fair_share.c
+++ linux-pm/drivers/thermal/gov_fair_share.c
@@ -21,23 +21,21 @@
*/
static int get_trip_level(struct thermal_zone_device *tz)
{
- struct thermal_trip trip;
- int count;
+ const struct thermal_trip *trip = tz->trips;
+ int i;
- for (count = 0; count < tz->num_trips; count++) {
- __thermal_zone_get_trip(tz, count, &trip);
- if (tz->temperature < trip.temperature)
+ if (tz->temperature < trip->temperature)
+ return 0;
+
+ for (i = 0; i < tz->num_trips - 1; i++) {
+ trip++;
+ if (tz->temperature < trip->temperature)
break;
}
Is it possible to use for_each_thermal_trip() instead ? That would make
the code more self-encapsulate
It is possible in principle, but this is a governor which is regarded
as part of the core, isn't it?
So is an extra overhead related to using a callback (which may be
subject to retpolines and such) really justified in this case?