[PATCH V7 4/4] Documentation: amd-pstate: Add unit test introduction
From: Meng Li
Date: Sun May 22 2022 - 07:55:40 EST
Introduce the AMD P-State unit test module design and implementation.
Signed-off-by: Meng Li <li.meng@xxxxxxx>
Acked-by: Huang Rui <ray.huang@xxxxxxx>
---
Documentation/admin-guide/pm/amd-pstate.rst | 76 +++++++++++++++++++++
1 file changed, 76 insertions(+)
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 83b58eb4ab4d..c2b8693601aa 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 +396,76 @@ 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 ::
+
+ jasminemeng@jasmine-meng:~/amd-brahma$ cd linux
+ jasminemeng@jasmine-meng:~/amd-brahma/linux$ make -C tools/testing/selftests
+
+ #. Installation & Steps ::
+
+ jasmine@jasmine-meng:~/amd-brahma/linux$ make -C tools/testing/selftests install INSTALL_PATH=~/kselftest
+ jasmine@jasmine-meng:~$ 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 ::
+
+ jasmine@jasmine-meng:~$ 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
--
2.25.1