Re: [PATCH] mm/gup: remove no longer used gup_fast_undo_dev_pagemap

[Alistair Popple <apopple@nvidia.com>]

On 2025-12-20 at 01:27 +1100, "David Hildenbrand (Red Hat)" <david@kernel.org> wrote...
> On 12/19/25 12:46, Kairui Song wrote:
> > From: Kairui Song <kasong@tencent.com>
> > 
> > This helper is no longer used after commit fd2825b0760a ("mm/gup: remove
> > pXX_devmap usage from get_user_pages()").

Thanks for catching, we no longer have to treat the dev pagemap pages specially
so it makes sense this isn't needed.

Reviewed-by: Alistair Popple <apopple@nvidia.com>

> > Signed-off-by: Kairui Song <kasong@tencent.com>
> > ---
> >   mm/gup.c | 11 -----------
> >   1 file changed, 11 deletions(-)
> > 
> > diff --git a/mm/gup.c b/mm/gup.c
> > index 95d948c8e86c..8e7dc2c6ee73 100644
> > --- a/mm/gup.c
> > +++ b/mm/gup.c
> > @@ -2806,17 +2806,6 @@ static bool gup_fast_folio_allowed(struct folio *folio, unsigned int flags)
> >   	return !reject_file_backed || shmem_mapping(mapping);
> >   }
> > -static void __maybe_unused gup_fast_undo_dev_pagemap(int *nr, int nr_start,
> > -		unsigned int flags, struct page **pages)
> > -{
> > -	while ((*nr) - nr_start) {
> > -		struct folio *folio = page_folio(pages[--(*nr)]);
> > -
> > -		folio_clear_referenced(folio);
> > -		gup_put_folio(folio, 1, flags);
> > -	}
> > -}
> > -
> 
> Thanks!
> 
> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
> 
> -- 
> Cheers
> 
> David