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authorMeng Li <li.meng@amd.com>2022-08-17 06:46:30 +0300
committerShuah Khan <skhan@linuxfoundation.org>2022-10-05 20:05:18 +0300
commit7fe3629729ce5466f865b75c506d7cb6223838ba (patch)
treee51b9f790ef4a887e90f78b197c197ce23986a2a /Documentation/admin-guide/pm
parente1083a03c553f12186556776e67eae44665318de (diff)
downloadlinux-7fe3629729ce5466f865b75c506d7cb6223838ba.tar.xz
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>
Diffstat (limited to 'Documentation/admin-guide/pm')
-rw-r--r--Documentation/admin-guide/pm/amd-pstate.rst76
1 files changed, 76 insertions, 0 deletions
diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 83b58eb4ab4d..8f3d30c5a0d8 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 ::
+
+ $ 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