Message ID | 20240124114930.12231-1-di.shen@unisoc.com (mailing list archive) |
---|---|
State | Changes Requested, archived |
Headers | show |
Series | thermal: power_allocator: initialize params->sustainable_power in the bind callback | expand |
Hi Di, Thanks for the patch. The code looks good, but let's adjust the description. So 1st line (subject): thermal: power_allocator: Avoid overwriting PID coefficients from setup time On 1/24/24 11:49, Di Shen wrote: > If we set the PID constants k_* via sysfs before the IPA algorithm is I would say: 'When the PID coefficients k_* are set via sysfs before the IPA algorithm is triggered then the coefficients would be overwritten after IPA throttle() is called. The old configuration values might be different than the new values estimated by the IPA internal algorithm.' I would also add something like this: 'There might be a time delay when this overwriting happens. It depends on the thermal zone temperature value. The temperature value needs to cross the first trip point value then IPA algorithms start operating. Although, the PID coefficients setup time should not be affected or linked to any later operating phase and values must not be overwritten.' Then we can drop this description from here... > triggered, the constants would be changed after IPA is triggered which > means the k_* are set fail. > > The process is as follow: > set k_* via sysfs > | > set emul_temp via sysfs(temperature > switch_on_temp) > | > throttle() > | > temp > switch_on > | > allocate_power > | > pid_controller > | > get_sustainable_power > | > if (sustainable_power != params->sustainable_power) > because the params->sustainable_power is not initialized first, > so params->sustainable_power = 0, the condition is true, then > call the estimate_pid_constants(). > | > estimate_pid_constants > | > The k_* are overwritten, the k_* we set before are invalid. > > For example: > unisoc:/sys/class/thermal/thermal_zone0 # cat policy > power_allocator > unisoc:/sys/class/thermal/thermal_zone0 # cat temp > 32722 > unisoc:/sys/class/thermal/thermal_zone0 # cat k_po > 307 > unisoc:/sys/class/thermal/thermal_zone0 # cat k_pu > 614 > unisoc:/sys/class/thermal/thermal_zone0 # cat k_i > 61 > unisoc:/sys/class/thermal/thermal_zone0 # cat k_* > 0 > 61 > 307 > 614 > > unisoc:/sys/class/thermal/thermal_zone0 # echo 300 > k_po > unisoc:/sys/class/thermal/thermal_zone0 # echo 600 > k_pu > unisoc:/sys/class/thermal/thermal_zone0 # echo 60 >k_i > unisoc:/sys/class/thermal/thermal_zone0 # cat k_* > 0 > 60 > 300 > 600 > > unisoc:/sys/class/thermal/thermal_zone0 # echo 70001 > emul_temp > unisoc:/sys/class/thermal/thermal_zone0 # cat k_* > 0 > 61 > 307 > 614 > unisoc:/sys/class/thermal/thermal_zone0 # echo 0 > emul_temp ... up to here. > > This patch initializes params->sustainable_power when the governor > binds to thermal zone to avoid overwriting k_*. > > The basic function won't be affected, as the k_* still can be estimated > if the sustainable_power is modified. > > Signed-off-by: Di Shen <di.shen@unisoc.com> > --- > drivers/thermal/gov_power_allocator.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c > index 81e061f183ad..1b17dc4c219c 100644 > --- a/drivers/thermal/gov_power_allocator.c > +++ b/drivers/thermal/gov_power_allocator.c > @@ -711,6 +711,8 @@ static int power_allocator_bind(struct thermal_zone_device *tz) > > if (!tz->tzp->sustainable_power) > dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n"); > + else > + params->sustainable_power = tz->tzp->sustainable_power; > > estimate_pid_constants(tz, tz->tzp->sustainable_power, > params->trip_switch_on, The code LGTM. Please sent next version of the patch. Regards, Lukasz
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c index 81e061f183ad..1b17dc4c219c 100644 --- a/drivers/thermal/gov_power_allocator.c +++ b/drivers/thermal/gov_power_allocator.c @@ -711,6 +711,8 @@ static int power_allocator_bind(struct thermal_zone_device *tz) if (!tz->tzp->sustainable_power) dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n"); + else + params->sustainable_power = tz->tzp->sustainable_power; estimate_pid_constants(tz, tz->tzp->sustainable_power, params->trip_switch_on,
If we set the PID constants k_* via sysfs before the IPA algorithm is triggered, the constants would be changed after IPA is triggered which means the k_* are set fail. The process is as follow: set k_* via sysfs | set emul_temp via sysfs(temperature > switch_on_temp) | throttle() | temp > switch_on | allocate_power | pid_controller | get_sustainable_power | if (sustainable_power != params->sustainable_power) because the params->sustainable_power is not initialized first, so params->sustainable_power = 0, the condition is true, then call the estimate_pid_constants(). | estimate_pid_constants | The k_* are overwritten, the k_* we set before are invalid. For example: unisoc:/sys/class/thermal/thermal_zone0 # cat policy power_allocator unisoc:/sys/class/thermal/thermal_zone0 # cat temp 32722 unisoc:/sys/class/thermal/thermal_zone0 # cat k_po 307 unisoc:/sys/class/thermal/thermal_zone0 # cat k_pu 614 unisoc:/sys/class/thermal/thermal_zone0 # cat k_i 61 unisoc:/sys/class/thermal/thermal_zone0 # cat k_* 0 61 307 614 unisoc:/sys/class/thermal/thermal_zone0 # echo 300 > k_po unisoc:/sys/class/thermal/thermal_zone0 # echo 600 > k_pu unisoc:/sys/class/thermal/thermal_zone0 # echo 60 >k_i unisoc:/sys/class/thermal/thermal_zone0 # cat k_* 0 60 300 600 unisoc:/sys/class/thermal/thermal_zone0 # echo 70001 > emul_temp unisoc:/sys/class/thermal/thermal_zone0 # cat k_* 0 61 307 614 unisoc:/sys/class/thermal/thermal_zone0 # echo 0 > emul_temp This patch initializes params->sustainable_power when the governor binds to thermal zone to avoid overwriting k_*. The basic function won't be affected, as the k_* still can be estimated if the sustainable_power is modified. Signed-off-by: Di Shen <di.shen@unisoc.com> --- drivers/thermal/gov_power_allocator.c | 2 ++ 1 file changed, 2 insertions(+)