Comment 41 for bug 1832472

Apols but looking you guys are knowledgeable with cdc_ncm

With the RTL8156 the rk3399 struggles slighlty with iperf3 @ 2.5gb but almost gets there.

Needs affinity to a big core though

[root@rockpi4 ~]# echo 5 > /proc/irq/221/smp_affinity_list
[root@rockpi4 ~]# iperf3 -c 192.168.1.9
Connecting to host 192.168.1.9, port 5201
[ 5] local 192.168.1.12 port 50268 connected to 192.168.1.9 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 251 MBytes 2.10 Gbits/sec 10 252 KBytes
[ 5] 1.00-2.00 sec 263 MBytes 2.21 Gbits/sec 0 252 KBytes
[ 5] 2.00-3.00 sec 255 MBytes 2.13 Gbits/sec 10 211 KBytes
[ 5] 3.00-4.00 sec 258 MBytes 2.17 Gbits/sec 20 182 KBytes
[ 5] 4.00-5.00 sec 258 MBytes 2.16 Gbits/sec 10 214 KBytes
[ 5] 5.00-6.00 sec 263 MBytes 2.22 Gbits/sec 0 214 KBytes
[ 5] 6.00-7.01 sec 257 MBytes 2.14 Gbits/sec 20 264 KBytes
[ 5] 7.01-8.00 sec 264 MBytes 2.22 Gbits/sec 0 264 KBytes
[ 5] 8.00-9.00 sec 257 MBytes 2.16 Gbits/sec 10 232 KBytes
[ 5] 9.00-10.00 sec 258 MBytes 2.17 Gbits/sec 10 234 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 2.52 GBytes 2.17 Gbits/sec 90 sender
[ 5] 0.00-10.00 sec 2.52 GBytes 2.17 Gbits/sec

What is confusing me is on Arm64 when you act as server/slave to a client the throughput drops drastically.

[root@rockpi4 ~]# iperf3 -c 192.168.1.9 -R
Connecting to host 192.168.1.9, port 5201
Reverse mode, remote host 192.168.1.9 is sending
[ 5] local 192.168.1.12 port 50280 connected to 192.168.1.9 port 5201
[ ID] Interval Transfer Bitrate
[ 5] 0.00-1.00 sec 51.9 MBytes 435 Mbits/sec
[ 5] 1.00-2.00 sec 46.2 MBytes 388 Mbits/sec
[ 5] 2.00-3.00 sec 48.4 MBytes 406 Mbits/sec
[ 5] 3.00-4.00 sec 46.2 MBytes 387 Mbits/sec
[ 5] 4.00-5.00 sec 59.9 MBytes 502 Mbits/sec
[ 5] 5.00-6.00 sec 53.2 MBytes 446 Mbits/sec
[ 5] 6.00-7.00 sec 48.6 MBytes 408 Mbits/sec
[ 5] 7.00-8.00 sec 56.8 MBytes 477 Mbits/sec
[ 5] 8.00-9.00 sec 45.8 MBytes 384 Mbits/sec
[ 5] 9.00-10.00 sec 48.9 MBytes 410 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate
[ 5] 0.00-10.00 sec 506 MBytes 424 Mbits/sec sender
[ 5] 0.00-10.00 sec 506 MBytes 424 Mbits/sec receiver

I don't understand why acting as a client to server should have this much difference?
Please post on Armbian https://forum.armbian.com/messenger/1867/?tab=comments#comment-14491 if you have any idea and apols but really struggling to find any info or mention about the rtl8156