Re: [RESEND PATCH V2 0/9] Implement AMD Pstate EPP Driver

[Huang Rui <ray.huang@amd.com>]

On Tue, Oct 11, 2022 at 12:22:39AM +0800, Yuan, Perry wrote:
> Hi all,
> 
> This patchset implements one new AMD CPU frequency driver
> "amd-pstate-epp” instance for better performance and power control.
> CPPC has a parameter called energy preference performance (EPP).
> The EPP is used in the CCLK DPM controller to drive the frequency that a core
> is going to operate during short periods of activity.
> EPP values will be utilized for different OS profiles (balanced, performance, power savings).
> 
> AMD Energy Performance Preference (EPP) provides a hint to the hardware
> if software wants to bias toward performance (0x0) or energy efficiency (0xff)
> The lowlevel power firmware will calculate the runtime frequency according to the EPP preference 
> value. So the EPP hint will impact the CPU cores frequency responsiveness.
> 
> We use the RAPL interface with "perf" tool to get the energy data of the package power.
> Performance Per Watt (PPW) Calculation:
> 
> The PPW calculation is referred by below paper:
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsoftware.intel.com%2Fcontent%2Fdam%2Fdevelop%2Fexternal%2Fus%2Fen%2Fdocuments%2Fperformance-per-what-paper.pdf&data=04%7C01%7CPerry.Yuan%40amd.com%7Cac66e8ce98044e9b062708d9ab47c8d8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637729147708574423%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=TPOvCE%2Frbb0ptBreWNxHqOi9YnVhcHGKG88vviDLb00%3D&reserved=0
> 
> Below formula is referred from below spec to measure the PPW:
> 
> (F / t) / P = F * t / (t * E) = F / E,
> 
> "F" is the number of frames per second.
> "P" is power measured in watts.
> "E" is energy measured in joules.
> 
> Gitsouce Benchmark Data on ROME Server CPU
> +------------------------------+------------------------------+------------+------------------+
> | Kernel Module                | PPW (1 / s * J)              |Energy(J) | PPW Improvement (%)|
> +==============================+==============================+============+==================+
> | acpi-cpufreq:schedutil       | 5.85658E-05                  | 17074.8    | base             |
> +------------------------------+------------------------------+------------+------------------+
> | acpi-cpufreq:ondemand        | 5.03079E-05                  | 19877.6    | -14.10%          |
> +------------------------------+------------------------------+------------+------------------+
> | acpi-cpufreq:performance     | 5.88132E-05                  | 17003      | 0.42%            |
> +------------------------------+------------------------------+------------+------------------+
> | amd-pstate:ondemand          | 4.60295E-05                  | 21725.2    | -21.41%          |
> +------------------------------+------------------------------+------------+------------------+
> | amd-pstate:schedutil         | 4.70026E-05                  | 21275.4    | -19.7%           |
> +------------------------------+------------------------------+------------+------------------+
> | amd-pstate:performance       | 5.80094E-05                  | 17238.6    | -0.95%           |
> +------------------------------+------------------------------+------------+------------------+
> | EPP:performance              | 5.8292E-05                   | 17155      | -0.47%           |
> +------------------------------+------------------------------+------------+------------------+
> | EPP: balance performance:    | 6.71709E-05                  | 14887.4    | 14.69%           |
> +------------------------------+------------------------------+------------+------------------+
> | EPP:power                    | 6.66951E-05                  | 4993.6     | 13.88%           |
> +------------------------------+------------------------------+------------+------------------+
> 
> Tbench Benchmark Data on ROME Server CPU
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | Kernel Module                               | PPW MB / (s * J)  |Throughput(MB/s)| Energy (J)|PPW Improvement(%)|
> +=============================================+===================+==============+=============+==================+
> | acpi_cpufreq: schedutil                     | 46.39             | 17191        | 37057.3     | base             |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | acpi_cpufreq: ondemand                      | 51.51             | 19269.5      | 37406.5     | 11.04 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | acpi_cpufreq: performance                   | 45.96             | 17063.7      | 37123.7     | -0.74 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: performance(0)               | 54.46             | 20263.1      | 37205       | 17.87 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: balance performance          | 55.03             | 20481.9      | 37221.5     | 19.14 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: balance_power                | 54.43             | 20245.9      | 37194.2     | 17.77 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | EPP:powersave: power(255)                   | 54.26             | 20181.7      | 37197.4     | 17.40 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | amd-pstate: schedutil                       | 48.22             | 17844.9      | 37006.6     | 3.80 %           |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | amd-pstate: ondemand                        | 61.30             | 22988        | 37503.4     | 33.72 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> | amd-pstate: performance                     | 54.52             | 20252.6      | 37147.8     | 17.81 %          |
> +---------------------------------------------+-------------------+--------------+-------------+------------------+
> 

Please add the test cycle number in the average test result.

Since Jasmine has submitted the TBench and Gitsource benchmark test suite
into amd-pstate-ut test module, I suggest to align the test script and make
sure everybody can use that script to get the similar accurate performance
per watt data even on the EPP mode.

https://lore.kernel.org/lkml/20220914061105.1982477-1-li.meng@amd.com/

Thanks,
Ray

> changes from v1:
>  * rebased to v6.0
>  * drive feedbacks from Mario for the suspend/resume patch
>  * drive feedbacks from Nathan for the EPP support on msr type
>  * fix some typos and code style indent problems
>  * update commit comments for patch 4/7
>  * change the `epp_enabled` module param name to `epp`
>  * set the default epp mode to be false
>  * add testing for the x86_energy_perf_policy utility patchset(will
>    send that utility patchset with another thread)
> 
> Perry Yuan (9):
>   ACPI: CPPC: Add AMD pstate energy performance preference cppc control
>   cpufreq: amd_pstate: add module parameter to load amd pstate EPP
>     driver
>   cpufreq: cpufreq: export cpufreq cpu release and acquire
>   x86/msr: Add the MSR definition for AMD CPPC boost state
>   Documentation: amd-pstate: add EPP profiles introduction
>   cpufreq: amd_pstate: add AMD pstate EPP support for shared memory type
>     processor
>   cpufreq: amd_pstate: add AMD Pstate EPP support for the MSR based
>     processors
>   cpufreq: amd_pstate: implement amd pstate cpu online and offline
>     callback
>   cpufreq: amd-pstate: implement suspend and resume callbacks
> 
>  Documentation/admin-guide/pm/amd-pstate.rst |  19 +
>  arch/x86/include/asm/msr-index.h            |   7 +
>  drivers/acpi/cppc_acpi.c                    | 128 ++-
>  drivers/cpufreq/amd-pstate.c                | 949 +++++++++++++++++++-
>  drivers/cpufreq/cpufreq.c                   |   2 +
>  include/acpi/cppc_acpi.h                    |  17 +
>  6 files changed, 1115 insertions(+), 7 deletions(-)
> 
> -- 
> 2.34.1
>