On 02/08/2017 22:02, Mason wrote: > I need to run the test slightly slower, to prevent packet loss > at the sender.
# iperf3 -c 172.27.64.45 -u -b 0 -l 1000 Connecting to host 172.27.64.45, port 5201 [ 4] local 172.27.64.1 port 42607 connected to 172.27.64.45 port 5201 [ ID] Interval Transfer Bandwidth Total Datagrams [ 4] 0.00-1.00 sec 111 MBytes 931 Mbits/sec 116420 [ 4] 1.00-2.00 sec 111 MBytes 931 Mbits/sec 116390 [ 4] 2.00-3.00 sec 111 MBytes 930 Mbits/sec 116220 [ 4] 3.00-4.00 sec 111 MBytes 930 Mbits/sec 116310 [ 4] 4.00-5.00 sec 111 MBytes 931 Mbits/sec 116380 [ 4] 5.00-6.00 sec 111 MBytes 930 Mbits/sec 116280 [ 4] 6.00-7.00 sec 111 MBytes 931 Mbits/sec 116390 [ 4] 7.00-8.00 sec 111 MBytes 931 Mbits/sec 116370 [ 4] 8.00-9.00 sec 111 MBytes 931 Mbits/sec 116340 [ 4] 9.00-10.00 sec 111 MBytes 930 Mbits/sec 116310 - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 4] 0.00-10.00 sec 1.08 GBytes 931 Mbits/sec 0.009 ms 278644/1163363 (24%) [ 4] Sent 1163363 datagrams iperf Done. # iperf3 -s Accepted connection from 172.27.64.1, port 42966 [ 5] local 172.27.64.45 port 5201 connected to 172.27.64.1 port 42607 [ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 5] 0.00-1.00 sec 81.1 MBytes 681 Mbits/sec 0.017 ms 26834/111909 (24%) [ 5] 1.00-2.00 sec 84.2 MBytes 706 Mbits/sec 0.019 ms 28127/116384 (24%) [ 5] 2.00-3.00 sec 84.2 MBytes 706 Mbits/sec 0.013 ms 27946/116204 (24%) [ 5] 3.00-4.00 sec 84.5 MBytes 709 Mbits/sec 0.013 ms 27674/116311 (24%) [ 5] 4.00-5.00 sec 84.6 MBytes 709 Mbits/sec 0.015 ms 27712/116387 (24%) [ 5] 5.00-6.00 sec 84.5 MBytes 709 Mbits/sec 0.010 ms 27649/116265 (24%) [ 5] 6.00-7.00 sec 84.3 MBytes 707 Mbits/sec 0.011 ms 27995/116382 (24%) [ 5] 7.00-8.00 sec 84.3 MBytes 707 Mbits/sec 0.013 ms 27972/116387 (24%) [ 5] 8.00-9.00 sec 84.3 MBytes 708 Mbits/sec 0.020 ms 27899/116343 (24%) [ 5] 9.00-10.00 sec 84.4 MBytes 708 Mbits/sec 0.014 ms 27759/116305 (24%) [ 5] 10.00-10.04 sec 3.25 MBytes 710 Mbits/sec 0.009 ms 1077/4486 (24%) - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 5] 0.00-10.04 sec 0.00 Bytes 0.00 bits/sec 0.009 ms 278644/1163363 (24%) IIUC, sender (desktop system) sends datagrams as fast as possible. Receiver (tango board) drops around 24% of all datagrams. I think this invalidates the theory that exhausting RX descriptors wedges RX DMA. Regards.
