Re: [PATCH net] selftests: drv-net: devmem: Skip when hugetlbfs isn't supported

From: Jakub Kicinski

Date: Tue Oct 27 2026 - 17:21:13 EST


On Mon, 26 Oct 2026 10:38:50 +0100 Maxime Chevallier wrote:
> On 10/23/26 19:52, Jakub Kicinski wrote:
> > On Wed, 21 Oct 2026 11:08:51 +0200 Maxime Chevallier wrote:
> >> The devmem selftest requires accessing /proc/sys/vm/nr_hugepages,
> >> which is only available when hugetlbfs is supported. This isn't the
> >> case on all CPU architectures, for example it isn't supported on ARM
> >> 32-bits on cores that don't support LPAE.
> >>
> >> On these devices, the devmem kselftest doesn't skip gracefully
> >
> > We don't require graceful skipping. If anything IMO hiding the stack
> > traces isn't great.
> >
> > If the check is extraneous and makes us fail some tests which don't
> > actually require huge pages please make that clear in the commit
> > message. Otherwise the net benefit of the changes is unclear.
>
> hugetlbfs isn't required for devmem AFAICS, but the blamed commit
> moved the access to nr_hugepages before the actual "is devmem
> actually supported" test.
>
> I don't expect the full test suite to gracefully run/skip for devmem
> on these arm32 platforms TBH, it's likely that devmem is only something
> that's been used on platforms that support hugetlbfs anyways, but
> strictly speaking both features are unrelated.

For max clarity I should have simply asked - does it make any test which
previously failed pass on any of your platforms? (incl. some WIP
patches that'd add devmem support) That's basically the criteria
I think we should use.