Re: [PATCH 11/29] selftests/mm: Drop test_uffdio_zeropage_eexist

Mike Kravetz
2023-04-01T00:03:43Z

On 03/30/23 12:07, Peter Xu wrote:
> The idea was trying to flip this var in the alarm handler from time to time
> to test -EEXIST of UFFDIO_ZEROPAGE, but firstly it's only used in the
> zeropage test so probably only used once, meanwhile we passed
> "retry==false" so it'll never got tested anyway.
>
> Drop both sides so we always test UFFDIO_ZEROPAGE retries if has_zeropage
> is set (!hugetlb).
>
> One more thing to do is doing UFFDIO_REGISTER for the alias buffer too,
> because otherwise the test won't even pass! We were just lucky that this
> test never really got ran at all.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> tools/testing/selftests/mm/userfaultfd.c | 20 +++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)

Thanks! With only passing "retry==false", that code is indeed dead. I had
to read the code again to understand area_dst_alias. Thanks for taking this
on as the code is difficult to understand.

Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
--
Mike Kravetz