Re: [LSF/MM TOPIC] FS, MM, and stable trees

[Sasha Levin <sashal@kernel.org>]

On Wed, Feb 13, 2019 at 12:14:35PM -0800, James Bottomley wrote:
>On Wed, 2019-02-13 at 20:52 +0100, Greg KH wrote:
>> On Wed, Feb 13, 2019 at 02:25:12PM -0500, Sasha Levin wrote:
>> > On Wed, Feb 13, 2019 at 10:18:03AM +0100, Greg KH wrote:
>> > > On Wed, Feb 13, 2019 at 11:01:25AM +0200, Amir Goldstein wrote:
>> > > > Best effort testing in timely manner is good, but a good way to
>> > > > improve confidence in stable kernel releases is a publicly
>> > > > available list of tests that the release went through.
>> > >
>> > > We have that, you aren't noticing them...
>> >
>> > This is one of the biggest things I want to address: there is a
>> > disconnect between the stable kernel testing story and the tests
>> > the fs/ and mm/ folks expect to see here.
>> >
>> > On one had, the stable kernel folks see these kernels go through
>> > entire suites of testing by multiple individuals and organizations,
>> > receiving way more coverage than any of Linus's releases.
>> >
>> > On the other hand, things like LTP and selftests tend to barely
>> > scratch the surface of our mm/ and fs/ code, and the maintainers of
>> > these subsystems do not see LTP-like suites as something that adds
>> > significant value and ignore them. Instead, they have a
>> > (convoluted) set of testing they do with different tools and
>> > configurations that qualifies their code as being "tested".
>> >
>> > So really, it sounds like a low hanging fruit: we don't really need
>> > to write much more testing code code nor do we have to refactor
>> > existing test suites. We just need to make sure the right tests are
>> > running on stable kernels. I really want to clarify what each
>> > subsystem sees as "sufficient" (and have that documented
>> > somewhere).
>>
>> kernel.ci and 0-day and Linaro are starting to add the fs and mm
>> tests to their test suites to address these issues (I think 0-day
>> already has many of them).  So this is happening, but not quite
>> obvious.  I know I keep asking Linaro about this :(
>
>0day has xfstests at least, but it's opt-in only (you have to request
>that it be run on your trees).  When I did it for the SCSI tree, I had
>to email Fenguangg directly, there wasn't any other way of getting it.

It's very tricky to do even if someone would just run it. I worked with
the xfs folks for quite a while to gather the various configs they want
to use, and to establish the baseline for a few of the stable trees
(some tests are know to fail, etc).

So just running xfstests "blindly" doesn't add much value beyond ltp I
think.

--
Thanks,
Sasha