From: Jakub Kicinski <kuba@xxxxxxxxxx>
Date: Wed, 14 May 2025 13:24:22 -0700
> On Tue, 13 May 2025 19:39:19 +0000 Eric Dumazet wrote:
> > Last change to tcp_rmem[2] happened in 2012, in commit b49960a05e32
> > ("tcp: change tcp_adv_win_scale and tcp_rmem[2]")
> >
> > TCP performance on WAN is mostly limited by tcp_rmem[2] for receivers.
> >
> > After this series improvements, it is time to increase the default.
>
> I think this breaks the BPF syncookie test, Kuniyuki any idea why?
>
> https://github.com/kernel-patches/bpf/actions/runs/15016644781/job/42196471693
It seems ACK was not handled by BPF at tc hook on lo.
ACK was not sent or tcp_load_headers() failed to parse it ?
both sounds unlikely though.
Will try to reproduce it.
