Re: [PATCH 2/3] net/xdp: convert put_page() to put_user_page*()

From: Christoph Hellwig
Date: Mon Jul 22 2019 - 05:34:33 EST


> diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
> index 83de74ca729a..9cbbb96c2a32 100644
> --- a/net/xdp/xdp_umem.c
> +++ b/net/xdp/xdp_umem.c
> @@ -171,8 +171,7 @@ static void xdp_umem_unpin_pages(struct xdp_umem *umem)
> for (i = 0; i < umem->npgs; i++) {
> struct page *page = umem->pgs[i];
>
> - set_page_dirty_lock(page);
> - put_page(page);
> + put_user_pages_dirty_lock(&page, 1);

Same here, we really should avoid the need for the loop here and
do the looping inside the helper.