Re: [PATCH] ext4: add .kunitconfig fragment to enable ext4-specific tests

[Daniel Latypov]

On Tue, Feb 9, 2021 at 6:33 PM Theodore Ts'o <tytso@xxxxxxx> wrote:
>
> On Tue, Feb 09, 2021 at 05:32:06PM -0800, Daniel Latypov wrote:
> >
> > After [2]:
> >   $ ./tools/testing/kunit.py run --kunitconfig=fs/ext4/.kunitconfig
>
> Any chance that in the future this might become:
>
> $ ./tools/testing/kunit.py run --kunitconfig=fs/ext4

I've been in favor of something like that for a while, but haven't
gotten folks to agree on the details.

Using bazel-like syntax for a bit, I'd really like it if we had some
easy way to do
$ kunit test //fs/...  # run all fs tests across all subdirs

But since there's the possibility of having tests w/ incompatible
requirements, I don't know that kunit.py can support it.
(Tbh, I think just concatenating fragments would probably just work
99% of the time so kunit.py could get away with doing that).

So --kunitconfig=<path> is currently a compromise to give us a less
controversial way of providing one-liners for testing a whole
subdirectory.

I don't think there'd be too much opposition for --kunitconfig to
automatically append ".kunitconfig" when passed a directory.
But there might be some, since a reader might think --kunitconfig=dir/
means it's recursing over all subdirs.

>
> Or better yet, syntactic sugar like:
>
> $ ./tools/testing/kunit.py test fs/ext4

The positional argument for run/exec is probably going to be taken by:
https://lore.kernel.org/linux-kselftest/20210206000854.2037923-1-dlatypov@xxxxxxxxxx/
https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/commit/?h=kunit&id=5d31f71efcb6bce56ca3ab92eed0c8f2dbcc6f9a

So we'd see something like:
$ ./tools/testing/kunit.py run --kunitconfig=fs/ext4 '*inode*'

Or if we set and followed naming conventions:
$ ./tools/testing/kunit.py run --alltests "ext4-*"
(this would take a lot longer to build however...)

Filtering could also let us curate only a few, less granular
.kunitconfig fragments (at the cost of higher build time).
E.g.
$ ./tools/testing/kunit.py run --kunitconfig=fs/ "ext4-*"

>
> would be really nice.
>
>                                                 - Ted