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Message-ID: <f7c14a37-3404-2ad0-bb71-2446b52c572d@kernel.org>
Date:   Thu, 3 Mar 2022 21:37:17 -0700
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Subject: Re: [PATCH v2 net-next 07/14] ipv6: add GRO_IPV6_MAX_SIZE
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To:     Eric Dumazet <eric.dumazet@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>
Cc:     netdev <netdev@vger.kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        Coco Li <lixiaoyan@google.com>,
        Alexander Duyck <alexanderduyck@fb.com>
References: <20220303181607.1094358-1-eric.dumazet@gmail.com>
 <20220303181607.1094358-8-eric.dumazet@gmail.com>
From:   David Ahern <dsahern@kernel.org>
In-Reply-To: <20220303181607.1094358-8-eric.dumazet@gmail.com>
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On 3/3/22 11:16 AM, Eric Dumazet wrote:
> From: Coco Li <lixiaoyan@google.com>
> 
> Enable GRO to have IPv6 specific limit for max packet size.
> 
> This patch introduces new dev->gro_ipv6_max_size
> that is modifiable through ip link.
> 
> ip link set dev eth0 gro_ipv6_max_size 185000
> 
> Note that this value is only considered if bigger than
> gro_max_size, and for non encapsulated TCP/ipv6 packets.
> 

What is the point of a max size for the Rx path that is per ingress
device? If the stack understands the larger packets then the ingress
device limits should not matter. (yes, I realize the existing code has
it this way, so I guess this is a historical question)