This section describes various latency tests.
Most of these tests use cut through PIO (CTPIO). This is a feature introduced in the X2 series of adapters, where packets to be sent are streamed directly over the PCIe bus to the network port, bypassing the main adapter transmit datapath. For more information refer to CTPIO.
The tests use different CTPIO modes, depending on the link speed:
- 10 Gb tests use cut-through CTPIO. This is supported only at 10 Gb.
- 25 Gb tests use variants of store and forward CTPIO.
Note: These different CTPIO modes require changes to the command lines, noted below.
The command lines given below use the taskset command to run the tests on core 1. Change this as necessary, to use an appropriate isolated core on your test system.