Received-SPF: pass (google.com: domain of linux-kernel+bounces-151884-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Date: Fri, 19 Apr 2024 14:51:45 -0400
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
To: Richard Gobert <richardbgobert@gmail.com>, 
 davem@davemloft.net, 
 edumazet@google.com, 
 kuba@kernel.org, 
 pabeni@redhat.com, 
 dsahern@kernel.org, 
 willemdebruijn.kernel@gmail.com, 
 alexander.duyck@gmail.com, 
 aleksander.lobakin@intel.com, 
 netdev@vger.kernel.org, 
 linux-kernel@vger.kernel.org
Cc: Richard Gobert <richardbgobert@gmail.com>
Message-ID: <6622bd416e567_1241e229425@willemb.c.googlers.com.notmuch>
In-Reply-To: <20240419153542.121087-2-richardbgobert@gmail.com>
References: <20240419153542.121087-1-richardbgobert@gmail.com>
 <20240419153542.121087-2-richardbgobert@gmail.com>
Subject: Re: [PATCH net v2 1/3] net: gro: add {inner_}network_offset to
 napi_gro_cb
Precedence: bulk
Mime-Version: 1.0
Content-Type: text/plain;
 charset=utf-8
Content-Transfer-Encoding: 7bit

Richard Gobert wrote:
> This patch adds network_offset and inner_network_offset to napi_gro_cb, and
> makes sure both are set correctly. In the common path there's only one
> write (skb_gro_reset_offset, which replaces skb_set_network_header).
> 
> Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
> ---
>  drivers/net/geneve.c           |  1 +
>  drivers/net/vxlan/vxlan_core.c |  1 +
>  include/net/gro.h              | 18 ++++++++++++++++--
>  net/8021q/vlan_core.c          |  2 ++
>  net/core/gro.c                 |  1 +
>  net/ethernet/eth.c             |  1 +
>  net/ipv4/af_inet.c             |  5 +----
>  net/ipv4/gre_offload.c         |  1 +
>  net/ipv6/ip6_offload.c         |  8 ++++----
>  9 files changed, 28 insertions(+), 10 deletions(-)
> 

> +static inline int skb_gro_network_offset(const struct sk_buff *skb)
> +{
> +	return NAPI_GRO_CB(skb)->network_offsets[NAPI_GRO_CB(skb)->encap_mark];
> +}
> +


> @@ -236,8 +236,6 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
>  	if (unlikely(!iph))
>  		goto out;
>  
> -	skb_set_network_header(skb, off);
> -

Especially for net, this is still a large patch.

Can we avoid touching all those tunnel callbacks and just set the
offsets in inet_gro_receive and ipv6_gro_receive themselves, just
as skb_set_network_header now:

@@ -236,7 +236,7 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
        if (unlikely(!iph))
                goto out;
 
-       skb_set_network_header(skb, off);
+       NAPI_GRO_CB(skb)->network_offsets[NAPI_GRO_CB(skb)->encap_mark] = off;