Re: [PATCH net-next] tcp: clamp window like before the cleanup

From: Matthieu Baerts
Date: Thu Mar 06 2025 - 06:22:15 EST


Hi Eric,

On 06/03/2025 12:08, Eric Dumazet wrote:
> On Thu, Mar 6, 2025 at 11:16 AM Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
>> On Thu, Mar 6, 2025 at 11:12 AM Matthieu Baerts <matttbe@xxxxxxxxxx> wrote:
>>> On 06/03/2025 11:02, Eric Dumazet wrote:

(...)

>>>> I am wondering if this could hide an issue in MPTCP ?
>>> Indeed, I was wondering the same thing. I didn't see anything obvious
>>> when looking at this issue. The behaviours around the window clamping,
>>> with MPTCP single flow, and "plain" TCP were quite similar I think.
>>
>> OK, let me run mptcp tests just in case I see something dubious.
>
> I have no idea why only MPTCP flows can trigger the condition, I do
> not think it matters anyway.

Thank you for having looked! Did you manage to trigger this condition
with "plain" TCP (without MPTCP) when using "./mptcp_connect.sh -tt"?

The TCP only connections will be printed like this:

nsX TCP -> nsY (<IP>:<port>) TCP

But yes, it probably doesn't matter.

Cheers,
Matt
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