Re: [PATCH V4 3/3] Documentation: amd-pstate: Add unit test introduction

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

On Wed, Apr 27, 2022 at 09:53:15PM +0800, Meng, Li (Jassmine) wrote:
> Introduce the AMD P-State unit test module design and implementation.
> 
> Signed-off-by: Meng Li <li.meng@amd.com>
> ---
>  Documentation/admin-guide/pm/amd-pstate.rst | 87 +++++++++++++++++++++
>  1 file changed, 87 insertions(+)
> 
> diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
> index 83b58eb4ab4d..395b8b5c680c 100644
> --- a/Documentation/admin-guide/pm/amd-pstate.rst
> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
> @@ -182,6 +182,7 @@ to the ``struct sugov_cpu`` that the utilization update belongs to.
>  Then, ``amd-pstate`` updates the desired performance according to the CPU
>  scheduler assigned.
>  
> +.. _processor_support:
>  
>  Processor Support
>  =======================
> @@ -282,6 +283,8 @@ efficiency frequency management method on AMD processors.
>  Kernel Module Options for ``amd-pstate``
>  =========================================
>  
> +.. _shared_mem:
> +
>  ``shared_mem``
>  Use a module param (shared_mem) to enable related processors manually with
>  **amd_pstate.shared_mem=1**.
> @@ -393,6 +396,87 @@ about part of the output. ::
>   CPU_005     712          116384        39        49        166       0.7565  9645075 2214891 38431470  25.1   11.646       469         2.496         kworker/5:0-40
>   CPU_006     712          116408        39        49        166       0.6769  8950227 1839034 37192089  24.06  11.272       470         2.496         kworker/6:0-1264
>  
> +Unit Tests for amd-pstate
> +-------------------------
> +
> +``amd-pstate-ut`` is a test module for testing the ``amd-pstate`` driver.
> +
> + * It can help all users to verify their processor support (SBIOS/Firmware or Hardware).
> +
> + * Kernel can have a basic function test to avoid the kernel regression during the update.
> +
> + * We can introduce more functional or performance tests to align the result together, it will benefit power and performance scale optimization.
> +
> +1. Test case decriptions
> +
> +        +---------+--------------------------------+------------------------------------------------------------------------------------+
> +        | Index   | Functions                      | Description                                                                        |
> +        +=========+================================+====================================================================================+
> +        | 0       | aput_acpi_cpc                  || Check whether the _CPC object is present in SBIOS.                                |
> +        |         |                                ||                                                                                   |
> +        |         |                                || The detail refer to `Processor Support <processor_support_>`_.                    |
> +        +---------+--------------------------------+------------------------------------------------------------------------------------+
> +        | 1       | aput_check_enabled             || Check whether AMD P-State is enabled.                                             |
> +        |         |                                ||                                                                                   |
> +        |         |                                || AMD P-States and ACPI hardware P-States always can be supported in one processor. |
> +        |         |                                | But AMD P-States has the higher priority and if it is enabled with                 |
> +        |         |                                | :c:macro:`MSR_AMD_CPPC_ENABLE` or ``cppc_set_enable``, it will respond to the      |
> +        |         |                                | request from AMD P-States.                                                         |
> +        +---------+--------------------------------+------------------------------------------------------------------------------------+
> +        | 2       | aput_check_perf                || Check if the each performance values are reasonable.                              |
> +        |         |                                || highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0.           |
> +        +---------+--------------------------------+------------------------------------------------------------------------------------+
> +        | 3       | aput_check_freq                || Check if the each frequency values and max freq when set support boost mode       |
> +        |         |                                | are reasonable.                                                                    |
> +        |         |                                || max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0                   |
> +        |         |                                || If boost is not active but supported, this maximum frequency will be larger than  |
> +        |         |                                | the one in ``cpuinfo``.                                                            |
> +        +---------+--------------------------------+------------------------------------------------------------------------------------+
> +
> +#. How to execute the tests
> +
> +   We use test module in the kselftest frameworks to implement it.
> +   We create amd-pstate-ut module and tie it into kselftest.(for
> +   details refer to Linux Kernel Selftests [4]_).
> +
> +    1. Build ::
> +
> +        jasminemeng@jasmine-meng:~/amd-brahma$ cd linux
> +        jasminemeng@jasmine-meng:~/amd-brahma/linux$ make modules M=tools/testing/selftests/amd-pstate/amd-pstate-ut
> +          CC [M]  tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.o
> +          MODPOST tools/testing/selftests/amd-pstate/amd-pstate-ut/Module.symvers
> +          CC [M]  tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.mod.o
> +          LD [M]  tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.ko
> +          BTF [M] tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.ko
> +        jasminemeng@jasmine-meng:~/amd-brahma/linux$ make -C tools/testing/selftests
> +
> +    #. Installation & Steps ::
> +
> +        jasmine@jasmine-MayanDAP-RMB:~/amd-brahma/linux$ make -C tools/testing/selftests install INSTALL_PATH=~/kselftest
> +        jasmine@jasmine-MayanDAP-RMB:~$ sudo cp amd-pstate-ut.ko /lib/modules/5.18.0-rc2+/

We should not mention a specfic kernel version "5.18.0-rc2+" here.

> +        jasmine@jasmine-MayanDAP-RMB:~$ sudo depmod
> +        jasmine@jasmine-MayanDAP-RMB:~$ sudo ./kselftest/run_kselftest.sh -c amd-pstate

"Can we move "insmod/rmmod amd-pstate-ut.ko" stuff into script amd_pstate_ut.sh?

Thanks,
Ray

> +        TAP version 13
> +        1..1
> +        # selftests: amd-pstate: amd-pstate-ut.sh
> +        # amd-pstate-ut: ok
> +        ok 1 selftests: amd-pstate: amd-pstate-ut.sh
> +
> +    #. Results ::
> +
> +         jasmine@jasmine-MayanDAP-RMB:~$ dmesg | grep "amd-pstate-ut" | tee log.txt
> +         [76697.480217] amd-pstate-ut: loaded.
> +         [76697.480222] amd-pstate-ut: ****** Begin 1             acpi_cpc_valid          ******
> +         [76697.480227] amd-pstate-ut: ****** End   1             acpi_cpc_valid          ******
> +         [76697.480228] amd-pstate-ut: ****** Begin 2             check_enabled           ******
> +         [76697.480253] amd-pstate-ut: ****** End   2             check_enabled           ******
> +         [76697.480255] amd-pstate-ut: ****** Begin 3             check_perf              ******
> +         [76697.480554] amd-pstate-ut: ****** End   3             check_perf              ******
> +         [76697.480556] amd-pstate-ut: ****** Begin 4             check_freq              ******
> +         [76697.480558] amd-pstate-ut: ****** End   4             check_freq              ******
> +         [76697.480559] amd-pstate-ut: all 4 tests passed
> +         [76697.482507] amd-pstate-ut: unloaded.
> +
>  
>  Reference
>  ===========
> @@ -405,3 +489,6 @@ Reference
>  
>  .. [3] Processor Programming Reference (PPR) for AMD Family 19h Model 51h, Revision A1 Processors
>         https://www.amd.com/system/files/TechDocs/56569-A1-PUB.zip
> +
> +.. [4] Linux Kernel Selftests,
> +       https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html
> -- 
> 2.25.1
>