Re: [PATCH mptcp-next v2] mptcp: update userspace pm subflows info

[Matthieu Baerts <matthieu.baerts@tessares.net>]

Hi Geliang,

On 13/01/2023 09:45, Geliang Tang wrote:
> Increase pm subflows counter when userspace pm creates a new subflow,
> and decrease the counter when it closes a subflow.
> 
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/329

(sorry for the delay)

Thank you, the patch looks good to me! But I don't think it is enough to
close the ticket 329.

I think there are other fields visible in `MPTCP_INFO` but only updated
by the in-kernel PM. e.g.

- add_addr_signaled
- add_addr_accepted
- local_addr_used

I guess these counters should be modified as well (in different
commits), no?

Also, I don't know if we should consider this as a "new feature" for
net-next: to me, it looks like we forgot to update the counters and it
is not really a new feature to update them but more a bug-fix. So maybe
we can target -net? I'm open to suggestions on that point :)

Not directly related but for the issue #330 -- 'subflows' counters not
incremented for the server side -- it could be considered as a bug fix
as well depending on how it is implemented: if it is backported, we
would have the same behaviour with all kernels. Or we add new field(s)
in MPTCP_INFO but this is maybe not needed.

Cheers,
Matt
-- 
Tessares | Belgium | Hybrid Access Solutions
www.tessares.net