netdev - Re: [PATCH 11/24] page_pool: Convert page_pool_empty

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Date:   Fri, 02 Dec 2022 13:25:55 -0800
From:   Alexander H Duyck <alexander.duyck@...il.com>
To:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        Jesper Dangaard Brouer <hawk@...nel.org>,
        Ilias Apalodimas <ilias.apalodimas@...aro.org>
Cc:     netdev@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 11/24] page_pool: Convert page_pool_empty_ring() to use
 netmem

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@...radead.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);
>  	}
>  }
>