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From:   Eric Dumazet <edumazet@google.com>
Date:   Sun, 9 Sep 2018 11:32:04 -0700
Message-ID: <CANn89iLN9H8tUhjMh1o0N7Ng8fPuXqQdpgkpBANpLwywaS3kNA@mail.gmail.com>
Subject: Re: [PATCH v2 net-next 2/2] tcp: fix the error count of tcpInSegs
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 Sat, Sep 8, 2018 at 8:14 PM Yafang Shao <laoar.shao@gmail.com> wrote:
>
> In RFC1213, the tcpInSegs is the total number of segments received.
> While currently it is the total number of SKBs received.
> The number of SKBs may be not equal with the numer of segments because of
> GRO.
> So fix this error count.
>

We have discussed this in the past and the consensus was it was too
late to change this.

IP counters have the same issue, so after your patch, we would have
quite a difference between transport and network layers.

Adding all these max_t(u16, 1, skb_shinfo(skb)->gso_segs)) everywhere add a cost