On 7/17/24 3:47 AM, Muhammad Usama Anjum wrote:
Hi David,
On 7/16/24 12:33 PM, David Gow wrote:
On Mon, 15 Jul 2024 at 18:09, Muhammad Usama Anjum
<usama.anjum@xxxxxxxxxxxxx> wrote:
Hi Kees and All,
There are several tests in kselftest subsystem which load modules to tests
the internals of the kernel. Most of these test modules are just loaded by
the kselftest, their status isn't read and reported to the user logs. Hence
they don't provide benefit of executing those tests.
I've found patches from Kees where he has been converting such kselftests
to kunit tests [1]. The probable motivation is to move tests output of
kselftest subsystem which only triggers tests without correctly reporting
the results. On the other hand, kunit is there to test the kernel's
internal functions which can't be done by userspace.
Kselftest: Test user facing APIs from userspace
Kunit: Test kernel's internal functions from kernelspace
Yes: this is how we'd like to split things up. There are still a few
Me too. It works.
cases where you might want to use kselftest to test something other
than a user-facing API (if you needed to set up some complicated
userspace structures, etc), or cases where KUnit might be used to test
something other than individual pieces of functionality, but that
categorisation is a good start.
Yeah, makes sense. It is helpful to find out what others think. I'll be
back with changes.
At some point we could connect up the two systems, without really
changing any of the guidelines...much. One way to do that would
be to add a tiny bit of kselftest support for easily launching
a kunit baremetal testing, and then reading the results (which
are right there in sysfs) back to user space.
So it would look like a kselftest, but it could run any kernel-based
tests it needs via kunit.
And the two systems can still be used independently.
The Documentation/dev-tools/testing-overview.rst page has a more
detailed look at when to use which test framework (which basically
just repeats those rules):
https://docs.kernel.org/dev-tools/testing-overview.html
Yes, a nice example of up-to-date documentation there. And it's
very clear.
Cheers,
-- David
thanks,
--
John Hubbard
NVIDIA
