Re: [PATCH 2/5] tests default_vmlinux_btf: Introduce test for using BTF by default

[Eduard Zingerman <eddyz87@gmail.com>]

On Tue, 2024-11-19 at 16:49 -0300, Arnaldo Carvalho de Melo wrote:

[...]

> > Lgtm.
> > Would it make sense to move this patch to the end of the series?
> > In case someone does a bisect and runs the tests to find some regression.
> 
> Humm?
> 
> So you think it should be introduced only when it passes? I.e. when the
> problem is fixed?

Right.

> My practice so far has been to reproduce the problem manually, write a
> test, show that it detects the problem, fix, then show that the
> regression test shows that the problem is not present anymore.

Yes, the downside would be that anyone trying out the fix would
need to do some rebase to try the test w/o fix.

> I see your point about a bisection when running in the cset that
> introduces the test case and in all before the fix is added will fail,
> confusing the bisector or not allowing it to be automated :-\
> 
> So, yeah, probably, for automated bisection we should move it to after
> the fix, when finishing the devel cycle, which is now, will do.

Fwiw, that's what folks enforce for bpf selftests ¯\_(ツ)_/¯.