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sm8250 faces the same problem with its Energy Model as sdm845. The energy cost of LITTLE cores is reported to be higher than medium or big cores EM computes the energy with formula: energy = OPP's cost / maximum cpu capacity * utilization On v6.4-rc6 we have: max capacity of CPU0 = 284 capacity of CPU0's OPP(1612800Hz) = 253 cost of CPU0's OPP(1612800Hz) = 191704 max capacity of CPU4 = 871 capacity of CPU4's OPP(710400 Hz) = 255 cost of CPU4's OPP(710400 Hz) = 343217 Both OPPs have almost the same compute capacity but the estimated energy per unit of utilization will be estimated to: energy CPU0 = 191704 / 284 * 1 = 675 energy CPU4 = 343217 / 871 * 1 = 394 EM estimates that little CPU0 will consume 71% more than medium CPU4 for the same compute capacity. According to [1], little consumes 25% less than medium core for Coremark benchmark at those OPPs for the same duration. Set the dynamic-power-coefficient of CPU0-3 to 105 to fix the energy model for little CPUs. [1] https://github.com/kdrag0n/freqbench/tree/master/results/sm8250/k30s Fixes:6aabed5526("arm64: dts: qcom: sm8250: Add CPU capacities and energy model") Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20230615154852.130076-1-vincent.guittot@linaro.org Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.