Re: [PATCH net-next] tcp: update window_clamp together with scaling_ratio

[Jakub Kicinski <kuba@kernel.org>]

On Tue,  2 Apr 2024 14:54:06 -0700 Hechao Li wrote:
> After commit dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale"),
> we noticed an application-level timeout due to reduced throughput. This
> can be reproduced by the following minimal client and server program.

Hi Hechao, nice to e-meet you :)

I suspect Eric may say that SO_RCVBUF = 64k is not very reasonable.
But I'll leave the technical review to him.

What I noticed is that our cryptic CI system appears to point at this
change as breaking BPF tests:

https://netdev.bots.linux.dev/flakes.html?min-flip=0&pw-n=0&tn-needle=gh-bpf

We accumulate all outstanding patches and test together.
BPF broke at net-next-2024-04-03--00-00, and:

$ cidiff origin/net-next-2024-04-02--21-00 \
         origin/net-next-2024-04-03--00-00

+tcp: update window_clamp together with scaling_ratio
+tools: ynl: ethtool.py: Output timestamping statistics from tsinfo-get operation
+netlink: specs: ethtool: add header-flags enumeration
+net/mlx5e: Implement ethtool hardware timestamping statistics
+net/mlx5e: Introduce timestamps statistic counter for Tx DMA layer
+net/mlx5e: Introduce lost_cqe statistic counter for PTP Tx port timestamping CQ
+ethtool: add interface to read Tx hardware timestamping statistics

The other patches are all driver stuff..

Here's the BPF CI output:

https://github.com/kernel-patches/bpf/actions/runs/8538300303