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From:   Axel Rasmussen <axelrasmussen@google.com>
Date:   Wed, 12 Apr 2023 10:07:51 -0700
Message-ID: <CAJHvVch3fv2Z509fSha5R3VCvp_unPNgy7QUA+Xbet2J6hJhOA@mail.gmail.com>
Subject: Re: [PATCH v2 10/31] selftests/mm: Test UFFDIO_ZEROPAGE only when !hugetlb
To:     Peter Xu <peterx@redhat.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Nadav Amit <nadav.amit@gmail.com>,
        David Hildenbrand <david@redhat.com>,
        Mike Rapoport <rppt@linux.vnet.ibm.com>,
        Leonardo Bras Soares Passos <lsoaresp@redhat.com>
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On Wed, Apr 12, 2023 at 9:42=E2=80=AFAM Peter Xu <peterx@redhat.com> wrote:
>
> Make the check as simple as "test_type =3D=3D TEST_HUGETLB" because that'=
s the
> only mem that doesn't support ZEROPAGE.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>

The end state we get to in patch 26 is what I was hoping for - we
check the ioctls reported by UFFDIO_REGISTER to decide if we rest this
or not. So then this intermediate state used to get rid of
get_expected_ioctls() is fine.

Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>

> ---
>  tools/testing/selftests/mm/userfaultfd.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/mm/userfaultfd.c b/tools/testing/sel=
ftests/mm/userfaultfd.c
> index 795fbc4d84f8..d724f1c78847 100644
> --- a/tools/testing/selftests/mm/userfaultfd.c
> +++ b/tools/testing/selftests/mm/userfaultfd.c
> @@ -1118,7 +1118,7 @@ static int __uffdio_zeropage(int ufd, unsigned long=
 offset, bool retry)
>  {
>         struct uffdio_zeropage uffdio_zeropage;
>         int ret;
> -       bool has_zeropage =3D get_expected_ioctls(0) & (1 << _UFFDIO_ZERO=
PAGE);
> +       bool has_zeropage =3D !(test_type =3D=3D TEST_HUGETLB);
>         __s64 res;
>
>         if (offset >=3D nr_pages * page_size)
> --
> 2.39.1
>