Re: [PATCH V5 0/3] Add unit test module for AMD P-State driver

[Shuah Khan]

On 5/17/22 8:45 AM, Shuah Khan wrote:
> On 5/5/22 12:41 AM, Huang Rui wrote:
> > On Thu, May 05, 2022 at 10:29:10AM +0800, Meng, Li (Jassmine) wrote:
> > > Hi all:
> > >
> > > AMD P-State unit test(amd-pstate-ut) is a kernel module for testing
> > > the functions of amd-pstate driver.
> > > It could import as a module to launch some test tasks.
> > > 1) It can help all users to verify their processor support (SBIOS/
> > > Firmware or Hardware).
> > > 2) Kernel can have a basic function test to avoid the kernel regression
> > > during the update.
> > > 3) We can introduce more functional or performance tests to align the
> > > together, it will benefit power and performance scale optimization.
> > >
> > > We upstream out AMD P-state driver into Linux kernel and use this unit
> > > test module to verify the required conditions and basic functions of
> > > amd-pstate before integration test.
> > >
> > > We use test module in the kselftest frameworks to implement it.
> > > We create amd-pstate-ut module and tie it into kselftest.
> > >
> > > For example: The test case aput_acpi_cpc is used to check whether the
> > > _CPC object is exist in SBIOS.
> > > The amd-pstate initialization will fail if the _CPC in ACPI SBIOS is not
> > > existed at the detected processor, so it is a necessary condition.
> > >
> > > At present, it only implements the basic framework and some simple test
> > > cases.
> > >
> > > TODO : 1) we will add more test cases to improve the depth and coverage of
> > > the test.
> > >
> > > Please check the documentation amd-pstate.rst for details of the test steps.
> > >
> > > See patch series in below git repo:
> > > V1: https://lore.kernel.org/linux-pm/20220323071502.2674156-1-li.meng@xxxxxxx/
> > > V2: https://lore.kernel.org/lkml/20220413090510.4039589-1-li.meng@xxxxxxx/
> > > V3: https://lore.kernel.org/lkml/20220421074152.599419-1-li.meng@xxxxxxx/
> > > V4: https://lore.kernel.org/lkml/20220427135315.3447550-1-li.meng@xxxxxxx/
>
> > > Changes from V4 -> V5:
> > > - selftests: amd-pstate:
> > > - - add print the current scaling_driver.
> > > - - add amd-pstate-ut.ko into TEST_GEN_FILES.
> > > - - move "insmod/rmmod amd-pstate-ut.ko" stuff into script amd_pstate_ut.sh
> > > - - add a check of read back from X86_FEATURE_CPPC in get_shared_mem().
> > > - Documentation: amd-pstate:
> > > - - delete the test step about insmod/rmmod amd-pstate-ut.ko
> > >
> > > Thanks,
> > > Jasmine
>
> Sorry for the delay on this. I will review the series in the next couple
> of days.
>
> Did you consider using KUnit for this? I think asked that question when
> reviewing the previous version.

I reviewed the patches and the test driver amd-pstate-ut doesn't belong under
selftests. I would recommend the following approach:

- add this test driver under drivers/cpufreq

- KUnit is a better fit for this unit test driver unless you want
  to be able to run this without KUnit configured

- add the test script under selftests - the script then can load the
  test driver and run tests and unload the driver.

thanks,
-- Shuah