[PATCH 2/3] PM: EM: Make em_cpu_energy() able to return bigger values
From: Lukasz Luba <lukasz.luba@arm.com>
Date: 2021-06-25 15:26:48
Also in:
lkml
Subsystem:
energy model, the rest · Maintainers:
Lukasz Luba, "Rafael J. Wysocki", Linus Torvalds
The Energy Model (EM) em_cpu_energy() is responsible for providing good estimation regarding CPUs energy. It contains proper data structures which are then used during calculation. The values stored in there are in milli-Watts precision (or in abstract scale) smaller that 0xffff, which use sufficient unsigned long even on 32-bit machines. There are scenarios where we would like to provide calculated estimations in a better precision and the values might be 1000 times bigger. This patch makes possible to use quite big values for also 32-bit machines. Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> --- include/linux/energy_model.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
index 3f221dbf5f95..2016f5a706e0 100644
--- a/include/linux/energy_model.h
+++ b/include/linux/energy_model.h@@ -101,7 +101,7 @@ void em_dev_unregister_perf_domain(struct device *dev); * Return: the sum of the energy consumed by the CPUs of the domain assuming * a capacity state satisfying the max utilization of the domain. */ -static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, +static inline u64 em_cpu_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util, unsigned long allowed_cpu_cap) {
@@ -180,7 +180,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, * pd_nrg = ------------------------ (4) * scale_cpu */ - return ps->cost * sum_util / scale_cpu; + return div_u64((u64)ps->cost * sum_util, scale_cpu); } /**
@@ -217,7 +217,7 @@ static inline struct em_perf_domain *em_pd_get(struct device *dev) { return NULL; } -static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, +static inline u64 em_cpu_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util, unsigned long allowed_cpu_cap) {
--
2.17.1