From: Yafang Shao <laoar.shao@gmail.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Eric Dumazet <edumazet@google.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
Subject: Re: [bpf-next 1/2] tcp: replace SOCK_DEBUG() with tcp_stats()
Date: Wed, 13 Feb 2019 11:04:21 +0800 [thread overview]
Message-ID: <CALOAHbA4PrgV8tem3cMt+22Vm2GQw=oaRsXMcAr2XBgX8hhjKw@mail.gmail.com> (raw)
In-Reply-To: <CAADnVQKhEshkWSDeYJ92pWnJjqawGSScBH+LU4iXsqwwxYjO9g@mail.gmail.com>
On Wed, Feb 13, 2019 at 10:49 AM Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
>
> 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.
kprobe is not suitable, because we have to use the line number, that's
a trouble cross all kernel versions.
Regarding tracepoints, I don't think it is a good idea to introduce
more and more tcp tracepoints and make them crowed as well.
> Instrumenting every tcp counter increment is overkill.
next prev parent reply other threads:[~2019-02-13 3:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-12 11:31 [bpf-next 0/2] cleanup SOCK_DEBUG() and introduce BPF_SOCK_OPS_STATS_CB Yafang Shao
2019-02-12 11:31 ` [bpf-next 1/2] tcp: replace SOCK_DEBUG() with tcp_stats() Yafang Shao
2019-02-12 15:07 ` Eric Dumazet
2019-02-13 2:07 ` Yafang Shao
2019-02-13 2:15 ` Eric Dumazet
2019-02-13 2:46 ` Yafang Shao
2019-02-13 2:49 ` Alexei Starovoitov
2019-02-13 3:04 ` Yafang Shao [this message]
2019-02-12 11:31 ` [bpf-next 2/2] bpf: add BPF_SOCK_OPS_STATS_CB for tcp_stats() Yafang Shao
2019-02-12 15:11 ` Eric Dumazet
2019-02-13 2:10 ` Yafang Shao
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