I compared the network throughput performance on SLES12 bare metal servers, between SLES12 default kernel and latest linux-next (2015-11-05) kernel, based on the test results, I suspect there is a network regression exists on Linux-Next over the 40G Ethernet network: a) iperf3 reports 50% performance drop with single TCP stream on latest linux-next; b) iperf3 reports 10% ~ 30% performance drop with 2 to 128 TCP streams on latest linux-next; Another throughput benchmarking tool (ntttcp-for-linux) test result is also listed at the end of the email for reference. Server configuration: ------------------------------ Two servers (one client and one server, cross linked by 40G Ethernet), which have: a) CPU: Intel(R) Xeon(R) CPU E5-2667 v3 @ 3.20GHz, 2 sockets, 16 CPUs, cache size : 20480 KB b) Memory: 64 GB c) Ethernet controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro], 40G Ethernet, default driver Test with iperf3: ------------------------------ iperf3: https://github.com/esnet/iperf a) SLES12 default kernel, network throughput tested by iperf3: Test Connections 1 2 4 8 16 32 64 128 Throughput (G bps) 36.7 37.3 37.6 37.7 37.7 37.7 37.7 25.7 b) SLES12 + Linux-Next 20151105, network throughput tested by iperf3: Test Connections 1 2 4 8 16 32 64 128 Throughput (G bps) 18.2 32.2 34.6 32.8 27.6 32.0 27.0 21.3 Percentage dropped -50% -14% -8% -13% -27% -15% -28% -17% Test with ntttcp-for-linux: ------------------------------ ntttcp-for-linux: https://github.com/Microsoft/ntttcp-for-linux a) SLES12 default kernel, network throughput tested by ntttcp-for-linux: Test Connections 1 2 4 8 16 32 64 128 256 512 Throughput (Gbps) 36.19 37.29 37.67 37.68 37.7 37.72 37.74 37.76 37.81 37.9 b) SLES12 + Linux-Next 20151105, network throughput tested by ntttcp-for-linux: Test Connections 1 2 4 8 16 32 64 128 256 512 Throughput (Gbps) 28.12 34.01 37.6 36.53 32.94 33.07 33.63 33.44 33.83 34.42 Percentage dropped -22% -9% 0% -3% -13% -12% -11% -11% -11% -9% _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
