On Fri, Mar 03, 2023 at 10:47:33AM +0100, Matthieu Baerts wrote: > Hi Greg, Naresh, Paolo, > > Thank you for the new version and for having reported the issue and running MPTCP selftests! > > 3 Mar 2023 10:23:06 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>: > > > On Fri, Mar 03, 2023 at 02:34:05PM +0530, Naresh Kamboju wrote: > >> On Fri, 3 Mar 2023 at 13:34, Paolo Abeni <pabeni@xxxxxxxxxx> wrote: > >>> > >>> Hello, > >>> > >>> On Fri, 2023-03-03 at 01:32 +0530, Naresh Kamboju wrote: > >>>> On Thu, 2 Mar 2023 at 16:30, Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote: > >>>>> > >>>>> On Thu, 2 Mar 2023 at 16:00, Greg Kroah-Hartman > >>>>> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > >>>>>> … > >>>>> > >>>>> .... > >>>>> > >>>>>> … > >>>>> > >>>>> Me either. > >>>>> That is the reason I have shared "Assertion" above. > >>>>> > >>>>>> … > >>>>> > >>>>> We are running our bisection scripts. > >>>> > >>>> We have tested with 6.1.14 kselftests source again and it passes. > >>>> Now that we have upgraded to 6.2.1 kselftests source, we find that > >>>> there is this problem reported. so, not a kernel regression. > >>> > >>> I read the above as you are running self-tests from 6.2.1 on top of an > >>> older (6.1) kernel. Is that correct? > >> > >> correct. > >> > >>> If so failures are expected; > > > > Shouldn't the test be able to know that "new features" are not present > > and properly skip the test for when that happens? Otherwise this feels > > like a problem going forward as no one will know if this feature can be > > used or not (assuming it is a new feature and not just a functional > > change.) > > All MPTCP selftests are designed to run on the same kernel version > they are attached to. This allows us to do more checks knowing they > are not supposed to fail on newer kernel versions and not being > skipped if there is an error when trying to use the new feature. If > there are fixes, we make sure the stable team is Cc'ed. If there are > API changes, it would be visible because we would need to adapt > existing selftests. "Features" are not usually limited to specific kernel versions (think about the mess that "enterprise" kernels create by backports). And if they are, running a userspace test should be able to detect if the feature is present or not by the error returned to it, right? If not, then the feature is mis-designed. > That's how we thought we should design MPTCP selftests. Maybe we need to change this design? Yes, please "skip" tests for features that are just not present, do not fail them. > Is it a common practice to run selftests' latest version on older kernels? Yes. thanks, greg k-h
