How many kernel test frameworks?

I am in favour of using UML, however when I tried to use KUnit I ran into a bunch of problems being able to compile my tests at all seeing the tree I wrote a test for wouldn't compile without PCI being selected and that could not be done in UML. I managed to work around it but I suspect there's going to be a lot of these problems in the future [1].

I think the consensus at the time was roughly that we'd need to add more mocking to UML to allow these subsystems to use it, not to stop using UML entirely.

Furthermore, my position regarding kselftests changed during the course of the discussion because it wasn't clear what kselftests actually provides or where the in-kernel tests were (they are in lib/test*). There's very little documentation for kselftests and they seem to cover a bunch of different cases. In contrast, documentation is one of the things KUnit has done very well.

Logan

[1] https://lore.kernel.org/lkml/6d9b3b21-1179-3a45-7545-30aa...