Re: debugging TCP stalls on high-speed wifi

On Thu, Dec 12, 2019 at 9:50 AM Johannes Berg [off-list ref] wrote:

If you have any thoughts on this, I'd appreciate it.

Thanks for the detailed report!

I was curious:

o What's the sender's qdisc configuration?

o Would you be able to log periodic dumps (e.g. every 50ms or 100ms)
of the test connection using a recent "ss" binary and "ss -tinm", to
hopefully get a sense of buffer parameters, and whether the flow in
these cases is being cwnd-limited, pacing-limited,
send-buffer-limited, or receive-window-limited?

o Would you be able to share a headers-only tcpdump pcap trace?

thanks,
neal