# Re: \[PATCH 11/24\] page\_pool: Convert page\_pool\_empty\_ring() to use netmem

- From: Alexander H Duyck \<hidden\>
- Date: 2022-12-02 21:25:59 
- List: netdev
- Page: https://ratatoskr.run/netdev/2022/12/6520201
- Thread: https://ratatoskr.run/netdev/2022/11/6520146/t.md

```text
On Wed, 2022-11-30 at 22:07 +0000, Matthew Wilcox (Oracle) wrote:
> Retrieve a netmem from the ptr_ring instead of a page.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  net/core/page_pool.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index e727a74504c2..7a77e3220205 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -755,16 +755,16 @@ EXPORT_SYMBOL(page_pool_alloc_frag);
>  
>  static void page_pool_empty_ring(struct page_pool *pool)
>  {
> -	struct page *page;
> +	struct netmem *nmem;
>  
>  	/* Empty recycle ring */
> -	while ((page = ptr_ring_consume_bh(&pool->ring))) {
> +	while ((nmem = ptr_ring_consume_bh(&pool->ring)) != NULL) {
>  		/* Verify the refcnt invariant of cached pages */
> -		if (!(page_ref_count(page) == 1))
> +		if (!(netmem_ref_count(nmem) == 1))

One minor code nit here is that this could just be:
		if (netmem_ref_count(nmem) != 1)

>  			pr_crit("%s() page_pool refcnt %d violation\n",
> -				__func__, page_ref_count(page));
> +				__func__, netmem_ref_count(nmem));
>  
> -		page_pool_return_page(pool, page);
> +		page_pool_return_netmem(pool, nmem);
>  	}
>  }
>  

```