Re: [PATCH v5 net-next] net/tcp: trace all TCP/IP state transition with tcp_set_state tracepoint

From: Yafang Shao
Date: Fri Dec 08 2017 - 19:48:45 EST


2017-12-09 0:28 GMT+08:00 David Miller <davem@xxxxxxxxxxxxx>:
> From: Yafang Shao <laoar.shao@xxxxxxxxx>
> Date: Fri, 8 Dec 2017 23:50:44 +0800
>
>> 2017-12-08 23:42 GMT+08:00 David Miller <davem@xxxxxxxxxxxxx>:
>>> From: Yafang Shao <laoar.shao@xxxxxxxxx>
>>> Date: Fri, 8 Dec 2017 11:40:23 +0800
>>>
>>>> It will looks like these,
>>>>
>>>> if (sk->sk_protocol == IPPROTO_TCP)
>>>> __tcp_set_state(newsk, TCP_SYN_RECV);
>>>> else
>>>> newsk->sk_state = TCP_SYN_RECV;
>>>>
>>>>
>>>> if (sk->sk_protocol == IPPROTO_TCP)
>>>> __tcp_set_state(sk, TCP_CLOSE);
>>>> else
>>>> sk->sk_state = TCP_CLOSE;
>>>>
>>>> if (sk->sk_protocol == IPPROTO_TCP)
>>>> tcp_state_store(sk, state);
>>>> else
>>>> sk_state_store(sk, state);
>>>>
>>>>
>>>> Some redundant code.
>>>>
>>>> IMO, put these similar code into a wrapper is more nice.
>>>
>>> I think this discussion and how ugly this is getting shows that
>>> tracing the state transitions of a socket is perhaps not best as a TCP
>>> specific feature.
>>
>> Do you mean that tcp_set_state tracepoint should be replaced with
>> sk_set_state tracepoint and move that tracepoint to
>> trace/events/sock.h ?
>
> Yes, something like that.
>
> It will avoid all of these protocol specific checks and weird
> dependencies.

That looks like a good idea.
I will try to reimplemnet it.


Thanks
Yafang