| Message ID | 20201124161025.27694-2-lukasz.luba@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Daniel Lezcano |
| Headers | show |
| Series | Improve the estimations in Intelligent Power Allocation | expand |
Hi Lukasz, On Tuesday 24 Nov 2020 at 16:10:23 (+0000), Lukasz Luba wrote: > Intelligent Power Allocation (IPA) is built around the PID controller > concept. The initialization code tries to setup the environment based on > the information available in DT or estimate the value based on minimum > power reported by each of the cooling device. The estimation will have an > impact on the PID controller behaviour via the related 'k_po', 'k_pu', > 'k_i' coefficients and also on the power budget calculation. > > This change prevents the situation when 'k_i' is relatively big compared > to 'k_po' and 'k_pu' values. This might happen when the estimation for > 'sustainable_power' returned small value, thus 'k_po' and 'k_pu' are > small. > > Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> > --- > drivers/thermal/gov_power_allocator.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c > index b29e21c56a4f..2e20085ed217 100644 > --- a/drivers/thermal/gov_power_allocator.c > +++ b/drivers/thermal/gov_power_allocator.c > @@ -134,6 +134,7 @@ static void estimate_pid_constants(struct thermal_zone_device *tz, > int ret; > int switch_on_temp; > u32 temperature_threshold; > + s32 k_i; > > ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp); > if (ret) > @@ -159,8 +160,11 @@ static void estimate_pid_constants(struct thermal_zone_device *tz, > tz->tzp->k_pu = int_to_frac(2 * sustainable_power) / > temperature_threshold; > > - if (!tz->tzp->k_i || force) > - tz->tzp->k_i = int_to_frac(10) / 1000; > + if (!tz->tzp->k_i || force) { > + k_i = tz->tzp->k_pu / 10; > + tz->tzp->k_i = k_i > 0 ? k_i : 1; > + } > + > /* > * The default for k_d and integral_cutoff is 0, so we can > * leave them as they are. > -- I see this patch did not change so: Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com> > 2.17.1 >
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c index b29e21c56a4f..2e20085ed217 100644 --- a/drivers/thermal/gov_power_allocator.c +++ b/drivers/thermal/gov_power_allocator.c @@ -134,6 +134,7 @@ static void estimate_pid_constants(struct thermal_zone_device *tz, int ret; int switch_on_temp; u32 temperature_threshold; + s32 k_i; ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp); if (ret) @@ -159,8 +160,11 @@ static void estimate_pid_constants(struct thermal_zone_device *tz, tz->tzp->k_pu = int_to_frac(2 * sustainable_power) / temperature_threshold; - if (!tz->tzp->k_i || force) - tz->tzp->k_i = int_to_frac(10) / 1000; + if (!tz->tzp->k_i || force) { + k_i = tz->tzp->k_pu / 10; + tz->tzp->k_i = k_i > 0 ? k_i : 1; + } + /* * The default for k_d and integral_cutoff is 0, so we can * leave them as they are.
Intelligent Power Allocation (IPA) is built around the PID controller concept. The initialization code tries to setup the environment based on the information available in DT or estimate the value based on minimum power reported by each of the cooling device. The estimation will have an impact on the PID controller behaviour via the related 'k_po', 'k_pu', 'k_i' coefficients and also on the power budget calculation. This change prevents the situation when 'k_i' is relatively big compared to 'k_po' and 'k_pu' values. This might happen when the estimation for 'sustainable_power' returned small value, thus 'k_po' and 'k_pu' are small. Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- drivers/thermal/gov_power_allocator.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)