[dpdk-dev] l2fwd/l3fwd performance drop of about 25% ?

[Jun Han <junhanece@gmail.com>]

Hi all,

I have a quick question regarding the performance of DPDK l2fwd (Same
problem with l3fwd). I am seeing that when we start multiple ports (e.g.,
12 ports), for 64 byte packets, the RX rate is only at around 11 Mpps per
port, instead of 14.88 Mpps which is the line rate (with preablem+start of
delimeter + interframe gap). Do you know what could be the problem? I am
describing my experiment setup below.

Setup:
1. We have Intel Xeon E5-2680 (8 cores, 2.7GHz) dual socket, with 6x10GbE
Intel 82599EB dualport NICs (total of 12 ports). Machine A runs your
pktgen, and Machine B runs DPDK l2fwd, unmodified.

2. We are running pktgen on Machine A with the following command:
./app/build/pktgen -c ffff -n 4 --proc-type auto --socket-mem 1024,1024
--file-prefix pg -- -p 0xfff0 -P -m "1.0, 2.1, 3.2, 4.3, 8.4, 9.5, 10.6,
11.7, 12.8, 13.9, 14.10, 15.11"

3. We are running l2fwd on Machine B with the following command:
sudo ./build/l2fwd -c 0xff0f -n 4 -- -p 0xfff


Thank you very much in advance.
Jun