Re: [PATCH 3/3] mincore: Introduce the MINCORE_SWAP bit

[Konstantin Khlebnikov <khlebnikov@openvz.org>]

Pavel Emelyanov wrote:
> When a page is swapped out it should be included in the memory dump,
> but the existing mincore() doesn't report the set bit for such pages.
>
> Thus add a bit for swapped out pages.

We can reuse ANON bit there.
Plus you forget to handle migration-entries, they can be both file and anon too.

>
> Signed-off-by: Pavel Emelyanov<xemul@parallels.com>
>
> ---
>   include/linux/mman.h |    1 +
>   mm/mincore.c         |    2 +-
>   2 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/mman.h b/include/linux/mman.h
> index 9d1de16..bfe4038 100644
> --- a/include/linux/mman.h
> +++ b/include/linux/mman.h
> @@ -12,6 +12,7 @@
>
>   #define MINCORE_RESIDENT	0x1
>   #define MINCORE_ANON		0x2
> +#define MINCORE_SWAP		0x4
>
>   #ifdef __KERNEL__
>   #include<linux/mm.h>
> diff --git a/mm/mincore.c b/mm/mincore.c
> index 3163dfb..82c5c3e 100644
> --- a/mm/mincore.c
> +++ b/mm/mincore.c
> @@ -146,7 +146,7 @@ static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
>   			} else {
>   #ifdef CONFIG_SWAP
>   				pgoff = entry.val;
> -				*vec = mincore_page(&swapper_space, pgoff);
> +				*vec = mincore_page(&swapper_space, pgoff) | MINCORE_SWAP;
>   #else
>   				WARN_ON(1);
>   				*vec = MINCORE_RESIDENT;

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