Subject: Re: [PATCH net-next v5 2/3] net: mirror skb frag ref/unref helpers

From: Jakub Kicinski <[email-masked]>
Date: Tue, 9 Apr 2024 18:23:01 -0700

On Mon,  8 Apr 2024 08:29:57 -0700 Mina Almasry wrote:
> +#ifdef CONFIG_PAGE_POOL
> +static inline bool is_pp_page(struct page *page)
> +{
> +	return (page->pp_magic & ~0x3UL) == PP_SIGNATURE;
> +}
> +
> +/* page_pool_unref_page() lives in net/page_pool/helpers.h */
> +static inline void page_pool_ref_page(struct page *page)
> +{
> +	atomic_long_inc(&page->pp_ref_count);
> +}
> +
> +static inline bool napi_pp_get_page(struct page *page)
> +{
> +	page = compound_head(page);
> +
> +	if (!is_pp_page(page))
> +		return false;
> +
> +	page_pool_ref_page(page);
> +	return true;
> +}
> +#endif
> +
> +static inline void skb_page_ref(struct page *page, bool recycle)
> +{
> +#ifdef CONFIG_PAGE_POOL
> +	if (recycle && napi_pp_get_page(page))
> +		return;
> +#endif
> +	get_page(page);
> +}

Shifting of all this code from pp to skbuff catches the eye.
There aren't that many callers to these, can we start a new header?
We can then include page pool headers in the without worry.

I'll apply the other patches, they look independent.