Re: [PATCH net-next v2 4/4] selftests/net: packetdrill: add TCP MTU probing test
From: Esko Mobius
Date: Mon Nov 09 2026 - 11:49:48 EST
> AFAICT if we drop the tcp_timestamps=0 line here (so our SYN offers
> timestamps and the scripted SYN-ACK declines them), the script should
> pass unchanged with patch 1/4, and fail without it (2072-byte rather
> than 2048-byte TSO packets, i.e. 2 x 1036 bytes). So I'd suggest
> dropping that tcp_timestamps=0 line. That way this test also covers
> the active-side part of patch 1/4.
Thanks, Neal. I removed the timestamp override and updated the commit
message.
The revised test passed with patch 1 in all three IP modes on x86_64
KVM. On the same net-next base without patch 1, all three failed on the
first data packet. Packetdrill expected 2048 bytes of TCP payload and
received 2072, as you predicted.
v3 has this change.
Thanks,
Yongjian