- NETMAP VERSION - ------------------ 1. Install the netmap driver and the corresponding ixgbe/ driver - please go through netmap's documentation for installation instructions. We used the following command to set the compilation scripts for netmap (for ixgbe driver). # ./configure --kernel-dir=/path/to/kernel/src --no-drivers=i40e,virtio_net.c - To run mTCP clients correctly, you need to modify the RSS seed in ixgbe_main.c:ixgbe_setup_mrqc() function. Our mTCP stack uses a specific RSS seed (mentioned below). - seed[10] should be reset to { 0x05050505, 0x05050505, 0x05050505, 0x05050505, 0x05050505, 0x05050505, 0x05050505, 0x05050505, 0x05050505, 0x05050505 }; - Make sure that the underlying kernel module is correctly working. You can use sample applications to validate your setup. # make # sudo insmod ./netmap.ko # sudo insmod ./ixgbe/ixgbe.ko - For optimum performance you are suggested to bind NICS IRQs to arbitrary CPUs. Please use affinity-netmap.py script for this purpose. The current script is setup for the netmap ixgbe driver. Please use a variant of this file for other cases (igb, i40e etc.). # ./config/affinity-netmap.py ${IFACE} - Disable flow control in Ethernet layer # sudo ethtool -A ${IFACE} rx off # sudo ethtool -A ${IFACE} tx off - Disable lro (large receive offload) in Ethernet device. mTCP does not support large packet sizes (> 1514B) yet) # sudo ethtool -K ${IFACE} lro off - We used example/pktgen to test netmap raw network I/O performance. Netmap's pktgen can be used not only for packet generation but also packet reception. Since mTCP relies on RSS-based NIC hardware queues, we recommend using the following command-line arguments to test pkt-gen as a sink before testing mTCP for netmap. -SINK- (assuming the machine has 4 cpus) # sudo ./pkt-gen -i ${IFACE}-0 -f rx -c 1 -a 0 -b 64 & # sudo ./pkt-gen -i ${IFACE}-1 -f rx -c 1 -a 1 -b 64 & # sudo ./pkt-gen -i ${IFACE}-2 -f rx -c 1 -a 2 -b 64 & # sudo ./pkt-gen -i ${IFACE}-3 -f rx -c 1 -a 3 -b 64 & where ${IFACE} is netmap-enabled interface. The netmap README file shows a concise description on how to use the driver. We reiterate some points that are essential in understanding the command line arguments above. An interface name post-appended with a number means that the process will read traffic from the specified NIC hardware queue. `-a` argument lets the program bind to a specific core. 2. Setup mtcp library: # ./configure --enable-netmap # make - By default, mTCP assumes that there are 16 CPUs in your system. You can set the CPU limit, e.g. on a 32-core system, by using the following command: # ./configure --enable-netmap CFLAGS="-DMAX_CPUS=32" Please note that your NIC should support RSS queues equal to the MAX_CPUS value (since mTCP expects a one-to-one RSS queue to CPU binding). - In case `./configure' script prints an error, run the following command; and then re-do step-2 (configure again): # autoreconf -ivf - check libmtcp.a in mtcp/lib - check header files in mtcp/include - check example binary files in apps/example 3. Check the configurations in apps/example - epserver.conf for server-side configuration - epwget.conf for client-side configuration - you may write your own configuration file for your application 4. Run the applications. *If you run the application with one thread, mTCP core will assume that the multi-queues option is disabled. This assumption is only valid for netmap version.* 5. Netmap module (mtcp/src/netmap_module.c) by default uses blocking I/O by default. Most microbenchmarking applications (epserver/epwget) shows best performance with this setup in our testbed. In case the performance is sub-optimal in yours, we recommend that you try polling mode (by enabling CONST_POLLING in line 24). You can also try tweaking IDLE_POLL_WAIT/IDLE_POLL_COUNT macros while testing blocking mode I/O.