Re: [PATCH] mm/swap: Fix release_pages() when releasing devmap pages

[John Hubbard]

On 5/23/19 3:37 PM, ira.weiny@xxxxxxxxx wrote:
> From: Ira Weiny <ira.weiny@xxxxxxxxx>
> 
> 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: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: John Hubbard <jhubbard@xxxxxxxxxx>
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> ---
>  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))
> +				continue;
>  		}
>  
>  		page = compound_head(page);
> 

Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>

thanks,
-- 
John Hubbard
NVIDIA