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SubjectRe: [patch 2/2] mm, selftests: test return value of munmap for MAP_HUGETLB memory
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On Thu, 2015-03-26 at 16:23 -0700, David Rientjes wrote:
> When MAP_HUGETLB memory is unmapped, the length must be hugepage aligned,
> otherwise it fails with -EINVAL.
>
> All tests currently behave correctly, but it's better to explcitly test
> the return value for completeness and document the requirement,
> especially if users copy map_hugetlb.c as a sample implementation.
>
> Signed-off-by: David Rientjes <rientjes@google.com>
> ---
> tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c | 8 ++++++--
>
> diff --git a/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c
> --- a/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c
> +++ b/tools/testing/selftests/powerpc/mm/hugetlb_vs_thp_test.c
> @@ -21,9 +21,13 @@ static int test_body(void)
> * Typically the mmap will fail because no huge pages are
> * allocated on the system. But if there are huge pages
> * allocated the mmap will succeed. That's fine too, we just
> - * munmap here before continuing.
> + * munmap here before continuing. munmap() length of
> + * MAP_HUGETLB memory must be hugepage aligned.
> */
> - munmap(addr, SIZE);
> + if (munmap(addr, SIZE)) {
> + perror("munmap");
> + return 1;
> + }
> }
>
> p = mmap(addr, SIZE, PROT_READ | PROT_WRITE,

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

cheers




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