This energy model enables the use of energy- and capacity-aware CPU
frequency scaling.
Power and performance measurements were made using my freqbench [1]
benchmark coordinator, which uses EEMBC CoreMark [2] as the workload
and measures power usage using the integrated PMIC's fuel gauge (DS2784
in this case).
The energy model dynamic-power-coefficient values were calculated with
DPC = µW / MHz / V^2
for each OPP, and averaged across all OPPs within each cluster for the
final coefficient.
A Google Nexus 10 device running a downstream 3.4 kernel was used for
benchmarking to ensure proper frequency scaling and other low-level
controls.
Raw benchmark results can be found in the freqbench repository [3].
Below is a human-readable summary:
===== CPU 1 =====
Frequencies: 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700
200: 909 4.5 C/MHz 132 mW 36.2 J 6.9 I/mJ 275.0 s
300: 1366 4.6 C/MHz 212 mW 38.7 J 6.5 I/mJ 183.0 s
400: 1821 4.6 C/MHz 286 mW 39.3 J 6.4 I/mJ 137.3 s
500: 2253 4.5 C/MHz 375 mW 41.7 J 6.0 I/mJ 111.0 s
600: 2740 4.6 C/MHz 446 mW 40.7 J 6.1 I/mJ 91.2 s
700: 3199 4.6 C/MHz 513 mW 40.1 J 6.2 I/mJ 78.2 s
800: 3673 4.6 C/MHz 678 mW 46.1 J 5.4 I/mJ 68.1 s
900: 4090 4.5 C/MHz 764 mW 46.7 J 5.4 I/mJ 61.1 s
1000: 4586 4.6 C/MHz 878 mW 47.9 J 5.2 I/mJ 54.5 s
1100: 5060 4.6 C/MHz 1084 mW 53.6 J 4.7 I/mJ 49.4 s
1200: 5515 4.6 C/MHz 1225 mW 55.5 J 4.5 I/mJ 45.3 s
1300: 5933 4.6 C/MHz 1396 mW 58.9 J 4.2 I/mJ 42.1 s
1400: 6395 4.6 C/MHz 1662 mW 65.0 J 3.8 I/mJ 39.1 s
1500: 6897 4.6 C/MHz 1895 mW 68.7 J 3.6 I/mJ 36.3 s
1600: 7332 4.6 C/MHz 2198 mW 75.0 J 3.3 I/mJ 34.1 s
1700: 7826 4.6 C/MHz 2497 mW 79.8 J 3.1 I/mJ 31.9 s
[1] https://github.com/kdrag0n/freqbench
[2] https://www.eembc.org/coremark/
[3] https://github.com/kdrag0n/freqbench/tree/master/results/exynos5250/main
Signed-off-by: Danny Lin <danny@xxxxxxxxxxx>
---
arch/arm/boot/dts/exynos5250.dtsi | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi
index 2ea2caaca4e2..cc2fe0afcfc7 100644
--- a/arch/arm/boot/dts/exynos5250.dtsi
+++ b/arch/arm/boot/dts/exynos5250.dtsi
@@ -58,6 +58,8 @@ cpu0: cpu@0 {
clock-names = "cpu";
operating-points-v2 = <&cpu0_opp_table>;
#cooling-cells = <2>; /* min followed by max */
+ capacity-dmips-mhz = <1024>;
+ dynamic-power-coefficient = <800>;
};
cpu1: cpu@1 {
device_type = "cpu";
@@ -67,6 +69,20 @@ cpu1: cpu@1 {
clock-names = "cpu";
operating-points-v2 = <&cpu0_opp_table>;
#cooling-cells = <2>; /* min followed by max */
+ capacity-dmips-mhz = <1024>;
+ dynamic-power-coefficient = <800>;
+ };
+
+ cpu-map {
+ cluster0 {
+ core0 {
+ cpu = <&cpu0>;
+ };
+
+ core1 {
+ cpu = <&cpu1>;
+ };
+ };
};
};
--
2.29.2
