Documentation: amd-pstate: Add unit test introduction

Introduce the AMD P-State unit test module design and implementation.
It also talks about kselftest and how to use.

Signed-off-by: Meng Li <li.meng@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This commit is contained in:
Meng Li 2022-08-17 11:46:30 +08:00 committed by Shuah Khan
parent e1083a03c5
commit 7fe3629729

View file

@ -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 +396,76 @@ 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 | amd_pstate_ut_acpi_cpc_valid || Check whether the _CPC object is present in SBIOS. |
| | || |
| | || The detail refer to `Processor Support <processor_support_>`_. |
+---------+--------------------------------+------------------------------------------------------------------------------------+
| 1 | amd_pstate_ut_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 | amd_pstate_ut_check_perf || Check if the each performance values are reasonable. |
| | || highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0. |
+---------+--------------------------------+------------------------------------------------------------------------------------+
| 3 | amd_pstate_ut_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
+ open the :c:macro:`CONFIG_X86_AMD_PSTATE` configuration option.
+ set the :c:macro:`CONFIG_X86_AMD_PSTATE_UT` configuration option to M.
+ make project
+ make selftest ::
$ cd linux
$ make -C tools/testing/selftests
#. Installation & Steps ::
$ make -C tools/testing/selftests install INSTALL_PATH=~/kselftest
$ sudo ./kselftest/run_kselftest.sh -c amd-pstate
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 ::
$ dmesg | grep "amd_pstate_ut" | tee log.txt
[12977.570663] amd_pstate_ut: 1 amd_pstate_ut_acpi_cpc_valid success!
[12977.570673] amd_pstate_ut: 2 amd_pstate_ut_check_enabled success!
[12977.571207] amd_pstate_ut: 3 amd_pstate_ut_check_perf success!
[12977.571212] amd_pstate_ut: 4 amd_pstate_ut_check_freq success!
Reference
===========
@ -405,3 +478,6 @@ 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