netdev - Re: [PATCH net-next v6 3/5] page_pool: Allow drivers to hint on SKB recycling

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Message-ID: <CAFnufp2Qbq53rT17eZD97tm3o5OFJeHEDAyaW8VhVcy4u+KeNQ@mail.gmail.com>
Date:   Thu, 3 Jun 2021 20:45:19 +0200
From:   Matteo Croce <mcroce@...ux.microsoft.com>
To:     netdev@...r.kernel.org, linux-mm@...ck.org
Cc:     Ayush Sawal <ayush.sawal@...lsio.com>,
        Vinay Kumar Yadav <vinay.yadav@...lsio.com>,
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        Sven Auhagen <sven.auhagen@...eatech.de>
Subject: Re: [PATCH net-next v6 3/5] page_pool: Allow drivers to hint on SKB recycling

On Fri, May 21, 2021 at 6:16 PM Matteo Croce <mcroce@...ux.microsoft.com> wrote:
> +bool page_pool_return_skb_page(void *data)
> +{
> +       struct page_pool *pp;
> +       struct page *page;
> +
> +       page = virt_to_head_page(data);
> +       if (unlikely(page->pp_magic != PP_SIGNATURE))
> +               return false;
> +
> +       pp = (struct page_pool *)page->pp;
> +
> +       /* Driver set this to memory recycling info. Reset it on recycle.
> +        * This will *not* work for NIC using a split-page memory model.
> +        * The page will be returned to the pool here regardless of the
> +        * 'flipped' fragment being in use or not.
> +        */
> +       page->pp = NULL;
> +       page_pool_put_full_page(pp, virt_to_head_page(data), false);

Here I could just use the cached "page" instead of calling
virt_to_head_page() once again.

-- 
per aspera ad upstream