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From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
Date:   Tue, 12 Feb 2019 18:49:02 -0800
Message-ID: <CAADnVQKhEshkWSDeYJ92pWnJjqawGSScBH+LU4iXsqwwxYjO9g@mail.gmail.com>
Subject: Re: [bpf-next 1/2] tcp: replace SOCK_DEBUG() with tcp_stats()
To:     Eric Dumazet <edumazet@google.com>
Cc:     Yafang Shao <laoar.shao@gmail.com>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Alexei Starovoitov <ast@kernel.org>,
        Yonghong Song <yhs@fb.com>, Lawrence Brakmo <brakmo@fb.com>,
        David Miller <davem@davemloft.net>,
        netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, shaoyafang@didiglobal.com
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On Tue, Feb 12, 2019 at 6:15 PM Eric Dumazet <edumazet@google.com> wrote:
>
> Do not add more debugging stuff unless you can demonstrate
> they actually allowed you to find a real bug and that you sent a
> public fix for it.
>
> Just adding "cool stuff" in TCP stack does not please me, it is only
> more complexity for unproven gain.

I agree.
I don't see why this debugging of 'abnormal TCP' cannot be done
with kprobes and tracepoints.
Instrumenting every tcp counter increment is overkill.