From 44750f153699b6e4f851a399287e5c8df208d696 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Fri, 6 Jan 2023 17:46:18 +0100 Subject: arm64: dts: qcom: sdm845: correct dynamic power coefficients While stressing EAS on my dragonboard RB3, I have noticed that LITTLE cores where never selected as the most energy efficient CPU whatever the utilization level of waking task. energy model framework uses its cost field to estimate the energy with the formula: nrg = cost of the selected OPP * utilization / CPU's max capacity which ends up selecting the CPU with lowest cost / max capacity ration as long as the utilization fits in the OPP's capacity. If we compare the cost of a little OPP with similar capacity of a big OPP like : OPP(kHz) OPP capacity cost max capacity cost/max capacity LITTLE 1766400 407 351114 407 863 big 1056000 408 520267 1024 508 This can be interpreted as the LITTLE core consumes 70% more than big core for the same compute capacity. According to [1], LITTLE consumes 10% less than big core for Coremark benchmark at those OPPs. If we consider that everything else stays unchanged, the dynamic-power-coefficient of LITTLE core should be only 53% of the current value: 290 * 53% = 154 Set the dynamic-power-coefficient of CPU0-3 to 154 to fix the energy model. [1] https://github.com/kdrag0n/freqbench/tree/master/results/sdm845/main Fixes: 0e0a8e35d725 ("arm64: dts: qcom: sdm845: correct dynamic power coefficients") Signed-off-by: Vincent Guittot Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20230106164618.1845281-1-vincent.guittot@linaro.org --- arch/arm64/boot/dts/qcom/sdm845.dtsi | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'arch/arm64/boot/dts/qcom/sdm845.dtsi') diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi index 99edd2ba85e2..6c7acaab6e13 100644 --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi @@ -95,7 +95,7 @@ clocks = <&cpufreq_hw 0>; enable-method = "psci"; capacity-dmips-mhz = <611>; - dynamic-power-coefficient = <290>; + dynamic-power-coefficient = <154>; qcom,freq-domain = <&cpufreq_hw 0>; operating-points-v2 = <&cpu0_opp_table>; interconnects = <&gladiator_noc MASTER_APPSS_PROC 3 &mem_noc SLAVE_EBI1 3>, @@ -122,7 +122,7 @@ clocks = <&cpufreq_hw 0>; enable-method = "psci"; capacity-dmips-mhz = <611>; - dynamic-power-coefficient = <290>; + dynamic-power-coefficient = <154>; qcom,freq-domain = <&cpufreq_hw 0>; operating-points-v2 = <&cpu0_opp_table>; interconnects = <&gladiator_noc MASTER_APPSS_PROC 3 &mem_noc SLAVE_EBI1 3>, @@ -145,7 +145,7 @@ clocks = <&cpufreq_hw 0>; enable-method = "psci"; capacity-dmips-mhz = <611>; - dynamic-power-coefficient = <290>; + dynamic-power-coefficient = <154>; qcom,freq-domain = <&cpufreq_hw 0>; operating-points-v2 = <&cpu0_opp_table>; interconnects = <&gladiator_noc MASTER_APPSS_PROC 3 &mem_noc SLAVE_EBI1 3>, @@ -168,7 +168,7 @@ clocks = <&cpufreq_hw 0>; enable-method = "psci"; capacity-dmips-mhz = <611>; - dynamic-power-coefficient = <290>; + dynamic-power-coefficient = <154>; qcom,freq-domain = <&cpufreq_hw 0>; operating-points-v2 = <&cpu0_opp_table>; interconnects = <&gladiator_noc MASTER_APPSS_PROC 3 &mem_noc SLAVE_EBI1 3>, -- cgit