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From:   Eric Dumazet <edumazet@google.com>
Date:   Fri, 27 Jul 2018 20:38:44 -0700
Message-ID: <CANn89iKXPu=RKkLop4NJWZLixE__qYV2S=PngSj6ienuvWWL8g@mail.gmail.com>
Subject: Re: [PATCH net-next 1/2] tcp: call tcp_drop() in tcp collapse
To:     Yafang Shao <laoar.shao@gmail.com>
Cc:     David Miller <davem@davemloft.net>,
        netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Fri, Jul 27, 2018 at 8:35 PM Yafang Shao <laoar.shao@gmail.com> wrote:

> So what about LINUX_MIB_TCPOFOMERGE ?
> Regarding LINUX_MIB_TCPOFOMERGE,  a skb is already covered by another
> skb, is that dropping the packet or simply lowering the memory
> overhead ?

What do you think ?

If you receive two times the same payload, don't you have to drop one
of the duplicate ?

There is a a big difference between the two cases.