On 22/01/2021 00:33, Steven Tardy wrote: > On Thu, Jan 21, 2021 at 6:34 PM lejeczek via CentOS > <centos at centos.org <mailto:centos at centos.org>> wrote: > > Hi guys. > > Hoping some net experts my stumble upon this message, > I have > an IPoIB direct host to host connection and: > > -> $ ethtool ib1 > Settings for ib1: > Supported ports: [ ] > Supported link modes: Not reported > Supported pause frame use: No > Supports auto-negotiation: No > Supported FEC modes: Not reported > Advertised link modes: Not reported > Advertised pause frame use: No > Advertised auto-negotiation: No > Advertised FEC modes: Not reported > Speed: 40000Mb/s > Duplex: Full > Auto-negotiation: on > Port: Other > PHYAD: 255 > Transceiver: internal > Link detected: yes > > and that's both ends, both hosts, yet: > > > $ iperf3 -c 10.5.5.97 > Connecting to host 10.5.5.97, port 5201 > [ 5] local 10.5.5.49 port 56874 connected to > 10.5.5.97 port > 5201 > [ ID] Interval Transfer Bitrate > Retr Cwnd > [ 5] 0.00-1.00 sec 1.36 GBytes 11.6 Gbits/sec 0 > 2.50 MBytes > [ 5] 1.00-2.00 sec 1.87 GBytes 16.0 Gbits/sec 0 > 2.50 MBytes > [ 5] 2.00-3.00 sec 1.84 GBytes 15.8 Gbits/sec 0 > 2.50 MBytes > [ 5] 3.00-4.00 sec 1.83 GBytes 15.7 Gbits/sec 0 > 2.50 MBytes > [ 5] 4.00-5.00 sec 1.61 GBytes 13.9 Gbits/sec 0 > 2.50 MBytes > [ 5] 5.00-6.00 sec 1.60 GBytes 13.8 Gbits/sec 0 > 2.50 MBytes > [ 5] 6.00-7.00 sec 1.56 GBytes 13.4 Gbits/sec 0 > 2.50 MBytes > [ 5] 7.00-8.00 sec 1.52 GBytes 13.1 Gbits/sec 0 > 2.50 MBytes > [ 5] 8.00-9.00 sec 1.52 GBytes 13.1 Gbits/sec 0 > 2.50 MBytes > [ 5] 9.00-10.00 sec 1.52 GBytes 13.1 Gbits/sec 0 > 2.50 MBytes > - - - - - - - - - - - - - - - - - - - - - - - - - > [ ID] Interval Transfer Bitrate Retr > [ 5] 0.00-10.00 sec 16.2 GBytes 13.9 Gbits/sec > 0 sender > [ 5] 0.00-10.00 sec 16.2 GBytes 13.9 > Gbits/sec receiver > > It's rather an oldish platform which hosts the link, > PCIe is > only 2.0 but with link of x8 that should be able to carry > more than ~13Gbits/sec. > Infiniband is Mellanox's ConnectX-3. > > Any thoughts on how to track the bottleneck or any > thoughts > > > > Care to capture (a few seconds) of the *sender* side .pcap? > Often TCP receive window is too small or packet loss is to > blame or round-trip-time. > All of these would be evident in the packet capture. > > If you do multiple streams with the `-P 8` flag does that > increase the throughput? > > Google says these endpoints are 1.5ms apart: > > (2.5 megabytes) / (13 Gbps) = > 1.53846154 milliseconds > > > Seems that the platform in overall might not be enough. That bitrate goes down even further when CPUs are fully loaded & occupied. (I'll try to keep on investigating) What I'm trying next is to have both ports(a dual-port card) "teamed" by NM, with runner set to broadcast. I'm leaving out "p-key" which NM sets to "default"(which is working with a "regular" IPoIP connection) RHEL's "networking guide" docs say "...create a team from two or more Wired or InfiniBand connections..." When I try to stand up such a team, master starts but slaves, both, fail with: "... <info> [1611588576.8887] device (ib1): Activation: starting connection 'team1055-slave-ib1' (900d5073-366c-4a40-8c32-ac42c76f9c2e) <info> [1611588576.8889] device (ib1): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed') <info> [1611588576.8973] device (ib1): state change: prepare -> config (reason 'none', sys-iface-state: 'managed') <info> [1611588576.9199] device (ib1): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed') <warn> [1611588576.9262] device (ib1): Activation: connection 'team1055-slave-ib1' could not be enslaved <info> [1611588576.9272] device (ib1): state change: ip-config -> failed (reason 'unknown', sys-iface-state: 'managed') <info> [1611588576.9280] device (ib1): released from master device nm-team <info> [1611589045.6268] device (ib1): carrier: link connected ..." Any suggestions also appreciated. thanks, L