Re: [PATCH v18 00/19] kunit: introduce KUnit, the Linux kernel unit testing framework

shuah
2019-10-07T14:43:00Z

On 10/7/19 2:40 AM, Brendan Higgins wrote:
> On Sun, Oct 6, 2019 at 10:18 AM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>>
>> On Sun, Oct 6, 2019 at 9:55 AM Theodore Y. Ts'o <tytso@mit.edu> wrote:
>>>
>>> Well, one thing we *can* do is if (a) if we can create a kselftest
>>> branch which we know is stable and won't change, and (b) we can get
>>> assurances that Linus *will* accept that branch during the next merge
>>> window, those subsystems which want to use kself test can simply pull
>>> it into their tree.
>>
>> Yes.
>>
>> At the same time, I don't think it needs to be even that fancy. Even
>> if it's not a stable branch that gets shared between different
>> developers, it would be good to just have people do a "let's try this"
>> throw-away branch to use the kunit functionality and verify that
>> "yeah, this is fairly convenient for ext4".
>>
>> It doesn't have to be merged in that form, but just confirmation that
>> the infrastructure is helpful before it gets merged would be good.
>
> I thought we already had done this satisfactorily.
>
Adding a couple more tests will only help in the long run. The idea is
to see can this help

> We have one proof-of-concept test in the branch in the kselftest repo
> (proc sysctl test) that went out in the pull request, and we also had
> some other tests that were not in the pull request (there is the ext4
> timestamp stuff mentioned above, and we also had one against the list
> data structure), which we were planning on sending out for review once
> Shuah's pull request was accepted. I know the apparmor people also
> wrote some tests that they said were useful; however, I have not
> coordinated with them on upstreaming their tests. I know of some other
> people who are using it, but I don't think the tests are as far along
> for upstreaming.
>

Maybe that is a good start. To get the tests that are already in use
and get them in shape for upstream.

> The point is: I thought we had plenty of signal that KUnit would be
> useful to have merged into the mainline kernel. I thought the only
> reason it was rejected for 5.4 was due to the directory name issue
> combined with bad timing.
>

That is probably the initial thought. However, it makes perfect sense
to add a couple of tests in. We have a few weeks anyway and it gives
us more confidence on kunit.

I already have a branch that is in linux-next and it just has kunit in
it and I will rebase it to 5.4-rc1.

https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/log/?h=test

Let's use that for kunit work for 5.5. I won't add any kselftest patches
to it and keep it dedicated for kunit work. When tests are ready for
upstream, I can keep adding them to this branch.

thanks,
-- Shuah