Re: [PATCH v2 08/11] selftests/mm: fix uffd-unit-tests.c build failure due to missing MADV_COLLAPSE

[John Hubbard <jhubbard@nvidia.com>]

Correction: due to refactoring things a bit in v2, this patch's subject line is
no longer accurate. It should be changed to:

[PATCH v2 08/11] selftests/mm: fix build failures due to missing MADV_COLLAPSE

thanks,
-- 
John Hubbard
NVIDIA

On 6/2/23 19:15, John Hubbard wrote:
> MADV_PAGEOUT, MADV_POPULATE_READ, MADV_COLLAPSE are conditionally
> defined as necessary. However, that was being done in .c files, and a
> new build failure came up that would have been automatically avoided had
> these been in a common header file.
> 
> So consolidate and move them all to vm_util.h, which fixes the build
> failure.
> 
> An alternative approach from Muhammad Usama Anjum was: rely on "make
> headers" being required, and include asm-generic/mman-common.h. This
> works in the sense that it builds, but it still generates warnings about
> duplicate MADV_* symbols, and the goal here is to get a fully clean (no
> warnings) build here.
> 
> Reviewed-by: David Hildenbrand <david@redhat.com>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> ---
>  tools/testing/selftests/mm/cow.c        |  7 -------
>  tools/testing/selftests/mm/khugepaged.c | 10 ----------
>  tools/testing/selftests/mm/vm_util.h    | 10 ++++++++++
>  3 files changed, 10 insertions(+), 17 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
> index dc9d6fe86028..8882b05ec9c8 100644
> --- a/tools/testing/selftests/mm/cow.c
> +++ b/tools/testing/selftests/mm/cow.c
> @@ -30,13 +30,6 @@
>  #include "../kselftest.h"
>  #include "vm_util.h"
>  
> -#ifndef MADV_PAGEOUT
> -#define MADV_PAGEOUT 21
> -#endif
> -#ifndef MADV_COLLAPSE
> -#define MADV_COLLAPSE 25
> -#endif
> -
>  static size_t pagesize;
>  static int pagemap_fd;
>  static size_t thpsize;
> diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c
> index 97adc0f34f9c..e88ee039d0eb 100644
> --- a/tools/testing/selftests/mm/khugepaged.c
> +++ b/tools/testing/selftests/mm/khugepaged.c
> @@ -22,16 +22,6 @@
>  
>  #include "vm_util.h"
>  
> -#ifndef MADV_PAGEOUT
> -#define MADV_PAGEOUT 21
> -#endif
> -#ifndef MADV_POPULATE_READ
> -#define MADV_POPULATE_READ 22
> -#endif
> -#ifndef MADV_COLLAPSE
> -#define MADV_COLLAPSE 25
> -#endif
> -
>  #define BASE_ADDR ((void *)(1UL << 30))
>  static unsigned long hpage_pmd_size;
>  static unsigned long page_size;
> diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
> index b950bd16083a..07f39ed2efba 100644
> --- a/tools/testing/selftests/mm/vm_util.h
> +++ b/tools/testing/selftests/mm/vm_util.h
> @@ -63,3 +63,13 @@ int uffd_register_with_ioctls(int uffd, void *addr, uint64_t len,
>  
>  #define PAGEMAP_PRESENT(ent)	(((ent) & (1ull << 63)) != 0)
>  #define PAGEMAP_PFN(ent)	((ent) & ((1ull << 55) - 1))
> +
> +#ifndef MADV_PAGEOUT
> +#define MADV_PAGEOUT 21
> +#endif
> +#ifndef MADV_POPULATE_READ
> +#define MADV_POPULATE_READ 22
> +#endif
> +#ifndef MADV_COLLAPSE
> +#define MADV_COLLAPSE 25
> +#endif