Re: [igt-dev] [PATCH i-g-t v2 4/4] tests: DRM selftests: switch to KUnit

[Daniel Latypov]

On Tue, Nov 1, 2022, 6:53 AM Mauro Carvalho Chehab
<mauro.chehab@xxxxxxxxxxxxxxx> wrote:
> > Ah, the selection is in kunit.ko itself. kunit.filter_glob, set from
> > kunit.py with
> >
> > positional arguments:
> >   filter_glob           Filter which KUnit test suites/tests run at boot-time, e.g. list* or list*.*del_test
> > \
>
> Gah, permissions are 0:
>
>         module_param_named(filter_glob, filter_glob_param, charp, 0);
>
> You can't even see what filters were set via sysfs:
>
>         $ ls /sys/module/kunit/parameters/
>         stats_enabled
>
> So, once set, there's no way to change it.
>
> I wonder why this isn't 0x644.
>
> It sounds that, if we want to control it at runtime, we'll need to
> build with kunit as module, and unload/reload it every time if/when
> we want to run IGT with a different filtering ruleset.

kunit.filter_glob only works on built-in tests, which is why you can
only set it once atm.
There is no currently no way for KUnit to run a subset of tests in modules.

The module init code is here:
https://elixir.bootlin.com/linux/v6.0/source/lib/kunit/test.c#L620
As you can see, that func it calls just initializes and runs all the
suites: https://elixir.bootlin.com/linux/v6.0/source/lib/kunit/test.c#L589

This can of course be changed, just needs some work on the KUnit-side.

Daniel