Re: [PATCH 01/12] mm/gup.c: Remove redundant check for PCI P2PDMA page

Dan Williams
2024-09-22T01:02:12Z

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@nvidia.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> ---
> mm/gup.c | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index d19884e..5d2fc9a 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -2954,11 +2954,6 @@ static int gup_fast_devmap_leaf(unsigned long pfn, unsigned long addr,
> break;
> }
>
> - if (!(flags & FOLL_PCI_P2PDMA) && is_pci_p2pdma_page(page)) {
> - gup_fast_undo_dev_pagemap(nr, nr_start, flags, pages);
> - break;
> - }
> -

Looks good.

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