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

From: Daniel Latypov <dlatypov@google.com>
To: Mauro Carvalho Chehab <mauro.chehab@linux.intel.com>
Cc: "Petri Latvala" <petri.latvala@intel.com>,
	"Isabella Basso" <isabbasso@riseup.net>,
	"Trevor Woerner" <twoerner@gmail.com>,
	"open list:KERNEL SELFTEST FRAMEWORK"
	<linux-kselftest@vger.kernel.org>,
	"Magali Lemes" <magalilemes00@gmail.com>,
	"Maíra Canal" <maira.canal@usp.br>,
	"Tales Aparecida" <tales.aparecida@gmail.com>,
	"Brendan Higgins" <brendanhiggins@google.com>,
	"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
	leandro.ribeiro@collabora.com, igt-dev@lists.freedesktop.org,
	"ML dri-devel" <dri-devel@lists.freedesktop.org>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Nícolas F. R. A. Prado" <n@nfraprado.net>,
	"David Gow" <davidgow@google.com>,
	"Shuah Khan" <skhan@linuxfoundation.org>,
	"André Almeida" <andrealmeid@riseup.net>,
	"KUnit Development" <kunit-dev@googlegroups.com>
Subject: Re: [igt-dev] [PATCH i-g-t v2 4/4] tests: DRM selftests: switch to KUnit
Date: Tue, 1 Nov 2022 07:04:43 -0700	[thread overview]
Message-ID: <CAGS_qxr+xzr1Ea6Y+xr+hBrGqx6rFSh_Q3xHi=ND1aPoQd+jtA@mail.gmail.com> (raw)
In-Reply-To: <20221101145333.5960e6e7@maurocar-mobl2>

On Tue, Nov 1, 2022, 6:53 AM Mauro Carvalho Chehab
<mauro.chehab@linux.intel.com> 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