[PATCH] i915/selftest/igt_mmap: let mmap tests run in kthread

[Janusz Krzysztofik]

On Friday, 28 February 2025 08:49:21 CET Mikolaj Wasiak wrote:
> Hi Janusz,
> 
> > I agree with both Andi and Krzysztof comments.
> > 
> > If the issue is tracked in our bug tracker then please provide a link to its 
> > record in a Link: or even Closes: tag.  Do you have call traces on hand?  
> > Probably yes, so please consider adding a concise excerpt to your description.
> > 
> > While looking for similar cases, I've found commit 51104c19d857 ("kunit: test: 
> > Add vm_mmap() allocation resource manager") that seems to have resolved a 
> > similar issue for then newly added kunit tests accessing current->mm.  Maybe 
> > the approach used there is worth of reusing it for i915 selftests.
> > 
> > Thanks,
> > Janusz
> 
> Here is related bug
> Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13679
> 
> I've seen commit you found. It sadly uses symbols that aren't exported
> outside of mm module and kunit tests 

Well, strictly speaking, those core symbols were also not available to kunit, 
and that patch exported them to kunit namespace.  While i915 selftests are not 
kunit, they are still in-kernel tests, then maybe it would be acceptable to 
import the kunit namespace as needed to our selftests and use those symbols 
for the same purpose as intended.  CI already runs kunit tests, then builds 
the kernels with CONFIG_KUNIT=y.  The code of i915 selftest that will depend 
on those symbols may then just check for CONFIG_KUNIT defined and be skipped 
if not.

Thanks,
Janusz


> and so I can't replicate it in our
> selftest.
> 
> Mikołaj
>