Re: [RFC 01/10] mm/gup.c: Remove redundant check for PCI P2PDMA page

[David Hildenbrand <david@xxxxxxxxxx>]

On 11.04.24 02:57, Alistair Popple wrote:
> PCI P2PDMA pages are not mapped with pXX_devmap PTEs therefore the
> check in __gup_device_huge() is redundant. Remove it
>
> Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
> ---
>   mm/gup.c | 5 -----
>   1 file changed, 5 deletions(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index 2f8a2d8..a9c8a09 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -2683,11 +2683,6 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
>   			break;
>   		}
>   
> -		if (!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page)) {
> -			undo_dev_pagemap(nr, nr_start, flags, pages);
> -			break;
> -		}
> -
>   		SetPageReferenced(page);
>   		pages[*nr] = page;
>   		if (unlikely(try_grab_page(page, flags))) {

Rebasing on mm-unstable, you'll notice some minor conflicts, but nothing 
earth shattering :)

Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb