On Fri, Nov 22, 2019 at 10:50 AM Ilya Maximets <i.maxim...@ovn.org> wrote: > > On 22.11.2019 18:51, William Tu wrote: > > Hi Ilya and Eelco, > > > > Yiyang reports very poor TCP performance on his setup and I can > > also reproduce it on my machine. Somehow I think this might be a > > kernel issue, but I don't know where to debug this. Need your suggestion > > about how to debug. > > > > So the setup is like the system-traffic, creating 2 namespaces and > > veth devices and attach to OVS. I do remember to turn off tx offload > > and ping, UDP, nc (tcp-mode) works fine. > > > > TCP using iperf drops to 0Mbps after 4 seconds. >
Hi Ilya and Eelco, Thank you for your suggestion. > The key questions are: > * What is your kernel version? 5.4.0-rc5+ > * Does it work in generic mode? TCP not work (not a single packet and this is expected) > * Does it work if iperf generates UDP traffic? > ex. iperf3 -c 10.1.1.1 -t 3600 -u -b 10G/64 -l 1460 Yes, works fine. (I did -t 360) [ 5] 0.00-360.01 sec 128 GBytes 3.05 Gbits/sec 0.002 ms 4203436/93962933 (4.5%) coverage/show looks OK afxdp_cq_empty 0.0/sec 0.000/sec 0.3953/sec total: 1423 afxdp_tx_full 0.0/sec 0.000/sec 0.3947/sec total: 1421 > * It seems like a ring breakage or a umem memory leak. > So, what are the afxdp related coverage counters? Running TCP iperf3 ip netns exec at_ns0 iperf3 -c 10.1.1.2 -t 360 -i 1 [ ID] Interval Transfer Bandwidth [ 5] 0.00-1.00 sec 20.4 MBytes 171 Mbits/sec [ 5] 1.00-2.00 sec 12.1 MBytes 101 Mbits/sec [ 5] 2.00-3.00 sec 8.59 MBytes 72.1 Mbits/sec [ 5] 3.00-4.00 sec 11.6 MBytes 97.1 Mbits/sec [ 5] 4.00-5.00 sec 2.21 MBytes 18.5 Mbits/sec [ 5] 5.00-6.00 sec 10.1 MBytes 85.1 Mbits/sec [ 5] 6.00-7.00 sec 0.00 Bytes 0.00 bits/sec [ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec .... all zero... coverage/show looks also OK afxdp_cq_empty 0.0/sec 0.033/sec 0.0006/sec total: 2 > * Does OVS forward packets, i.e. if there something received/sent? > No packet arrives at OVS and no packet seen at the veth device attach to OVS. Based on these debug: 1) UDP works and TCP doesn't 2) correct coverage counter Then I think it's not related to umem ring management in OVS. But I should look at why veth driver, the XDP part, doesn't rx/tx packet. William _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
