Re: [PATCH v3] selftests/mm: add process_madvise() tests

[wang lian <lianux.mm@gmail.com>]

Hi Zi,

On <Date of Zi's email>, Zi Yan wrote:
> On 9 Jul 2025, at 8:32, wang lian wrote:
>
>> Hi Zi Yan,
>> Thanks for testing the patch and reporting this build failure.
>> I don't have an arm64 environment readily available for testing, so I
>> appreciate you catching this. I suspect this is caused by missing or
>> older userspace headers in the cross-compilation toolchain.
>
> Right. My /usr/include/sys does not have pidfd.h. IMHO selftests
> should not rely on userspace headers, otherwise we cannot test
> latest kernel changes.
>
>> I will try to fix this in the next version. If the problem persists, a
>> good solution would be to manually define the syscall wrapper to avoid
>> the dependency on <sys/pidfd.h>.
>
> Based on what I see in other mm tests, the following patch fixes my
> compilation issue.
>
> [ ... patch snippet ... ]

Thank you very much for not only identifying the root cause but also
providing a concrete patch to fix the compilation issue. Your analysis
that selftests should be independent of userspace headers is spot on,
and this approach aligns perfectly with the feedback I've received.

I have integrated your suggested changes into my local tree and will
include them in the next version of the patch. I will also be sure
to add your "Suggested-by" tag in the commit message to properly
credit your contribution.

Your help has been invaluable.

Best regards,
Wang Lian