On Mon, 2 Oct 2023 21:13:03 +0200 Antonio Di Bacco <[email protected]> wrote:
> I'm doing a test where we have a couple of tap devices, the two > devices are seen by testpmd that is setup in forward mode. > > On the linux side, the two tap devices are confined in different > network namespaces and in one namespace we have an iperf server while > on the other namespace the iperf client sending either UDP or TCP. > > I expected a bandwidth in the range of few gpbs while the actual > measured bandwidth is a few gigabits. > > I suppose I need to configure the tap devices with optimized > parameters but I don't know where to look for advice. > > If I try to use the loopback interface I can get something 40 gbps > with a command like this: > > iperf -c 127.0.0.1 -u -i 1 -b 40g -t 10 -l 40000 > > . Sorry TAP device is inherently slow. It requires copies to/from Linux kernel. You are doing well if you get 1 million packets per second. One thing to check is that checksum is not being done twice.
