Re: [PATCH] parisc: Fix up generic MADV_* values and add MADV_HWPOISON and MADV_SOFT_OFFLINE

Helge Deller
2017-08-04T17:57:28Z

On 04.08.2017 18:31, Helge Deller wrote:
> In addition there is a conflict with some the common/generic MADV_* constants
> between kernel headers and glibc headers.

Please ignore this patch.
I was wrong: kernel and glibc are in sync.

Nevertheless, maybe adjusting the parisc values to the default values in kernel and
glibe would make sense. Even if it's a ABI change, the impact of such a change is probably low
given the fact that those madvise values are hints.

Helge

> The existing glibc headers on parisc
> already define those values in the range of 8-17 which should be common between
> all architectures and which all architectures with the exception of parisc
> follow. But the parisc kernel still defines those with values above 65 because
> of an old kernel patch which reserved the range of 12-64 for page size
> specifications. The old kernel patch never actually used those values in code,
> so changing those MADV_* constants back to the common values shouldn't break
> anything and instead make existing userspace applications work as expected.
>
> Signed-off-by: Helge Deller <deller@gmx.de>
>
> diff --git a/arch/parisc/include/uapi/asm/mman.h b/arch/parisc/include/uapi/asm/mman.h
> index 5979745..a34ebf4 100644
> --- a/arch/parisc/include/uapi/asm/mman.h
> +++ b/arch/parisc/include/uapi/asm/mman.h
> @@ -49,16 +49,18 @@
> #define MADV_REMOVE 9 /* remove these pages & resources */
> #define MADV_DONTFORK 10 /* don't inherit across fork */
> #define MADV_DOFORK 11 /* do inherit across fork */
> +#define MADV_HWPOISON 100 /* poison a page for testing */
> +#define MADV_SOFT_OFFLINE 101 /* soft offline page for testing */
>
> -#define MADV_MERGEABLE 65 /* KSM may merge identical pages */
> -#define MADV_UNMERGEABLE 66 /* KSM may not merge identical pages */
> +#define MADV_MERGEABLE 12 /* KSM may merge identical pages */
> +#define MADV_UNMERGEABLE 13 /* KSM may not merge identical pages */
>
> -#define MADV_HUGEPAGE 67 /* Worth backing with hugepages */
> -#define MADV_NOHUGEPAGE 68 /* Not worth backing with hugepages */
> +#define MADV_HUGEPAGE 14 /* Worth backing with hugepages */
> +#define MADV_NOHUGEPAGE 15 /* Not worth backing with hugepages */
>
> -#define MADV_DONTDUMP 69 /* Explicity exclude from the core dump,
> +#define MADV_DONTDUMP 16 /* Explicity exclude from the core dump,
> overrides the coredump filter bits */
> -#define MADV_DODUMP 70 /* Clear the MADV_NODUMP flag */
> +#define MADV_DODUMP 17 /* Clear the MADV_NODUMP flag */
>
> /* compatibility flags */
> #define MAP_FILE 0
> diff --git a/tools/arch/parisc/include/uapi/asm/mman.h b/tools/arch/parisc/include/uapi/asm/mman.h
> index 03d8d5b..eb4df3e 100644
> --- a/tools/arch/parisc/include/uapi/asm/mman.h
> +++ b/tools/arch/parisc/include/uapi/asm/mman.h
> @@ -1,20 +1,22 @@
> #ifndef TOOLS_ARCH_PARISC_UAPI_ASM_MMAN_FIX_H
> #define TOOLS_ARCH_PARISC_UAPI_ASM_MMAN_FIX_H
> -#define MADV_DODUMP 70
> -#define MADV_DOFORK 11
> -#define MADV_DONTDUMP 69
> -#define MADV_DONTFORK 10
> -#define MADV_DONTNEED 4
> -#define MADV_FREE 8
> -#define MADV_HUGEPAGE 67
> -#define MADV_MERGEABLE 65
> -#define MADV_NOHUGEPAGE 68
> #define MADV_NORMAL 0
> #define MADV_RANDOM 1
> -#define MADV_REMOVE 9
> #define MADV_SEQUENTIAL 2
> -#define MADV_UNMERGEABLE 66
> #define MADV_WILLNEED 3
> +#define MADV_DONTNEED 4
> +#define MADV_FREE 8
> +#define MADV_REMOVE 9
> +#define MADV_DONTFORK 10
> +#define MADV_DOFORK 11
> +#define MADV_HWPOISON 100
> +#define MADV_SOFT_OFFLINE 101
> +#define MADV_MERGEABLE 12
> +#define MADV_UNMERGEABLE 13
> +#define MADV_HUGEPAGE 14
> +#define MADV_NOHUGEPAGE 15
> +#define MADV_DONTDUMP 16
> +#define MADV_DODUMP 17
> #define MAP_ANONYMOUS 0x10
> #define MAP_DENYWRITE 0x0800
> #define MAP_EXECUTABLE 0x1000
> @@ -36,10 +38,6 @@
> #define PROT_READ 0x1
> #define PROT_SEM 0x8
> #define PROT_WRITE 0x2
> -/* MADV_HWPOISON is undefined on parisc, fix it for perf */
> -#define MADV_HWPOISON 100
> -/* MADV_SOFT_OFFLINE is undefined on parisc, fix it for perf */
> -#define MADV_SOFT_OFFLINE 101
> /* MAP_32BIT is undefined on parisc, fix it for perf */
> #define MAP_32BIT 0
> /* MAP_UNINITIALIZED is undefined on parisc, fix it for perf */
>