Re: [PATCH 04/25] mm: remove MEMORY_DEVICE_PUBLIC support

[Dan Williams]

[ add Ira ]

On Wed, Jun 26, 2019 at 5:27 AM Christoph Hellwig <hch@xxxxxx> wrote:
>
> The code hasn't been used since it was added to the tree, and doesn't
> appear to actually be usable.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> Acked-by: Michal Hocko <mhocko@xxxxxxxx>
[..]
> diff --git a/mm/swap.c b/mm/swap.c
> index 7ede3eddc12a..83107410d29f 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -740,17 +740,6 @@ void release_pages(struct page **pages, int nr)
>                 if (is_huge_zero_page(page))
>                         continue;
>
> -               /* Device public page can not be huge page */
> -               if (is_device_public_page(page)) {
> -                       if (locked_pgdat) {
> -                               spin_unlock_irqrestore(&locked_pgdat->lru_lock,
> -                                                      flags);
> -                               locked_pgdat = NULL;
> -                       }
> -                       put_devmap_managed_page(page);
> -                       continue;
> -               }
> -

This collides with Ira's bug fix [1]. The MEMORY_DEVICE_FSDAX case
needs this to be converted to be independent of "public" pages.
Perhaps it should be pulled out of -mm and incorporated in this
series.

[1]: https://lore.kernel.org/lkml/20190605214922.17684-1-ira.weiny@xxxxxxxxx/