Re: [PATCH mptcp-next 4/4] selftests: mptcp: get stats just before timing out

[Matthieu Baerts <matttbe@kernel.org>]

Hi Geliang,

On 13/11/2025 08:15, Geliang Tang wrote:
> Hi Matt,
> 
> On Sat, 2025-11-08 at 15:20 +0100, Matthieu Baerts (NGI0) wrote:
>> Recently, some debugging happened around a test that was timing out.
>> The
>> stats were showing connections being closed which was confusing
>> because
>> the closing state was caused by the timeout stopping the transfer.
>>
>> To avoid such confusion, the timeout is no longer done per
>> mptcp_connect
>> process, but separately. In case of timeout, the stats are now
>> printed,
>> then the apps are killed.
>>
>> The stats will still be printed after the kill, but that's fine, and
>> this might even be useful, just in case. Timeout should be
>> exceptional.
> 
> Today I found that this patch has increased the runtime of the
> selftests, for example:
> 
> # 66 ns1 MPTCP -> ns1 (dead:beef:1::1:20004) MPTCP     (duration  
> 390ms) [ OK ]
> # 67 ns1 MPTCP -> ns1 (dead:beef:1::1:20005) TCP       (duration  
> 415ms) [ OK ]
> # 68 ns1 TCP   -> ns1 (dead:beef:1::1:20006) MPTCP     (duration  
> 380ms) [ OK ]
> # Time: 38 seconds
> ok 1 test: selftest_mptcp_connect
> # time=99
> 
> The mptcp_connect test ended after 38 seconds, but it waited an
> additional 61 seconds before finally stopping at 99 seconds.

Good catch, indeed, thanks, I will check that!

I guess I should use mptcp_lib_kill_group_wait() to kill the "sleep"
command as well.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.