On Thu, May 23, 2019 at 3:37 PM <[email protected]> wrote:
>
> From: Ira Weiny <[email protected]>
>
> Device pages can be more than type MEMORY_DEVICE_PUBLIC.
>
> Handle all device pages within release_pages()
>
> This was found via code inspection while determining if release_pages()
> and the new put_user_pages() could be interchangeable.
>
> Cc: Jérôme Glisse <[email protected]>
> Cc: Dan Williams <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: John Hubbard <[email protected]>
> Signed-off-by: Ira Weiny <[email protected]>
> ---
> mm/swap.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/mm/swap.c b/mm/swap.c
> index 3a75722e68a9..d1e8122568d0 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -739,15 +739,14 @@ 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 (is_zone_device_page(page)) {
> if (locked_pgdat) {
>
> spin_unlock_irqrestore(&locked_pgdat->lru_lock,
> flags);
> locked_pgdat = NULL;
> }
> - put_devmap_managed_page(page);
> - continue;
> + if (put_devmap_managed_page(page))
This "shouldn't" fail, and if it does the code that follows might get
confused by a ZONE_DEVICE page. If anything I would make this a
WARN_ON_ONCE(!put_devmap_managed_page(page)), but always continue
unconditionally.
Other than that you can add:
Reviewed-by: Dan Williams <[email protected]>
