Re: [PATCH] selftests/cgroup: conform test to TAP format output

[Guopeng Zhang]

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