Re: [PATCH] selftests/mm: run_vmtests.sh: fix relative path handling

[sun jian <sun.jian.kdev@gmail.com>]

> hm, why?  Is that a thing people actually do?
>
> Is anyone going to actually test this feature?

Yes — invoking selftests directly from the kernel root can easily happen in
practice, for example::

  sudo tools/testing/selftests/mm/run_vmtests.sh

This currently results in false failures because relative paths being resolved
against the caller's cwd instead of the script directory.
>
> Alternatively we could check that we're in the correct directory and
> error out if not.

That would also be reasonable, but I slightly prefer auto-cd because it
avoids an easy invocation pitfall and makes the runner more robust for
wrappers/CI
where the cwd is  not stable. That said, I'm happy to switch to a fail-fast cwd
check if you prefer the behavior.

Regards,
Sun