Re: [PATCH v3 1/3] selftests/mm: handle EINVAL when configuring gigantic hugepages

[Usama Arif <usama.arif@linux.dev>]

On Wed,  8 Jul 2026 12:29:05 +0530 Sayali Patil <sayalip@linux.ibm.com> wrote:

> Some MM selftests attempt to configure the amount of
> HugeTLB pages of different sizes by writing to nr_hugepages.
> 
> PowerPC hash MMU pSeries systems advertise gigantic hugepage sizes
> but do not support runtime allocation of such pages, writes
> to the corresponding nr_hugepages file fail with -EINVAL.
> This causes the test to bail out even though the failure is due
> to a platform limitation rather than the
> functionality being tested.
> 
> Ignore -EINVAL when configuring nr_hugepages so that tests continue to
> run on systems where gigantic hugepage allocation is unsupported.
> 
> Before patch:
>    -------------------------
>    running ./hugetlb-madvise
>    -------------------------
>    TAP version 13
>    1..1
>      [INFO] detected hugetlb page size: 16777216 KiB
>      [INFO] detected hugetlb page size: 16384 KiB
>     ok 1 MADV_DONTNEED and MADV_REMOVE on hugetlb
>     Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
>     Bail out! /sys/kernel/mm/hugepages/hugepages-16777216kB/nr_hugepages
>     write(0) failed: Invalid argument
>     Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0
>     [FAIL]
> 
> After patch:
>    -------------------------
>    running ./hugetlb-madvise
>    -------------------------
>    TAP version 13
>    1..1
>     [INFO] detected hugetlb page size: 16777216 KiB
>     [INFO] detected hugetlb page size: 16384 KiB
>    ok 1 MADV_DONTNEED and MADV_REMOVE on hugetlb
>    Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
>    [PASS]
> 
> Fixes: 27477b28b74f ("selftests/mm: hugepage_settings: add APIs to get and set nr_hugepages")
> Co-developed-by: David Hildenbrand (Arm) <david@kernel.org>
> Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
> Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
> ---
>  .../testing/selftests/mm/hugepage_settings.c  |  2 +-
>  tools/testing/selftests/mm/vm_util.c          | 26 ++++++++++++++++---
>  tools/testing/selftests/mm/vm_util.h          |  1 +
>  3 files changed, 24 insertions(+), 5 deletions(-)
> 

Acked-by: Usama Arif <usama.arif@linux.dev>