Re: [PATCH] mm/memory-failure: unecessary amount of unmapping

[Dan Williams <dan.j.williams@intel.com>]

On Mon, Apr 19, 2021 at 5:28 PM Jane Chu <jane.chu@oracle.com> wrote:
>
> It appears that unmap_mapping_range() actually takes a 'size' as its
> third argument rather than a location,

Indeed.

> the current calling fashion
> causes unecessary amount of unmapping to occur.

s/unecessary/unnecessary/

>
> Fixes: 6100e34b2526e ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages")
> Signed-off-by: Jane Chu <jane.chu@oracle.com>

Other than changelog fixup, looks good.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

> ---
>  mm/memory-failure.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index f7ed9559d494..85ad98c00fd9 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1368,7 +1368,7 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
>                  * communicated in siginfo, see kill_proc()
>                  */
>                 start = (page->index << PAGE_SHIFT) & ~(size - 1);
> -               unmap_mapping_range(page->mapping, start, start + size, 0);
> +               unmap_mapping_range(page->mapping, start, size, 0);
>         }
>         kill_procs(&tokill, flags & MF_MUST_KILL, !unmap_success, pfn, flags);
>         rc = 0;
> --
> 2.18.4
>