Hi Michal,
Thanks for reviewing and pointing out [1].
Could you please explain more why is the TAP layout beneficial? (I understand selftest are for oneself, i.e. human readable only by default.)
Actually, selftests are no longer just something for developers to view locally; they are now extensively run in CI and stable branch regression testing. Using a standardized layout means that general test runners and CI systems can parse the cgroup test results without any special handling.
TAP provides a structured format that is both human-readable and machine-readable. The plan/result lines are parsed by tools, while the diagnostic lines can still contain human-readable debug information. Over time, other selftest suites (such as mm, KVM, mptcp, etc.) have also been converted to TAP-style output, so this change just brings the cgroup tests in line with that broader direction.
Or is this part of some tree-wide effort?
This patch is not part of a formal, tree-wide conversion series I am running; it is an incremental step to align the cgroup C tests with the existing TAP usage. I started here because these tests already use ksft_test_result_*() and only require minor changes to generate proper TAP output.
I'm asking to better asses whether also the scripts listed in Makefile:TEST_PROGS should be converted too.
I agree that having them produce TAP output would benefit tooling and CI. I did not want to mix that into this change, but if you and other maintainers think this direction is reasonable, I would be happy to follow up and convert the cgroup shell tests to TAP as well.
Thanks again for your review.
Best regards, Guopeng