[dpdk-dev] Low packet generation rate of 526kpps using pktgen-dpdk from inside VM

[Abhishek Mahajan <abhishek.mahajan@aricent.com>]

Hi,

With pktgen-dpdk inside VM, it is observed that packet TX rate (526Kpps with 64byte size) is very low. How can higher packet rates be achieved ?

On enabling logs of virtio pmd in DPDK, getting following logs in syslogs:
PMD: virtio_xmit_pkts() tx: No free tx descriptors to transmit

Two PC setup having configuration as follow:
-> Xeon Processor : Intel(R) Xeon(R) CPU E5-2603 v3 @ 1.60GHz  having 6 cores.
-> RAM : 16GB
->One PC is generating traffic other is receiving the packets using pktgen tool. The two PC are connected directly with 10G Ethernet interface.

Generation side PC - Host
-> 2 cores dedicated to OVS-DPDK
-> 1 core is free for Linux kernel
-> OS: Ubuntu 14.04
-> Linux kernel : 3.13.0-85-generic
-> DPDK version : 2.2.0
-> OVS version : 2.5.0
-> VFIO driver for port binding

VM - Total 3 cores
-> 2 cores for pktgen
-> 1 core for Linux kernel
-> OS: Ubuntu 15.04
-> Linux kernel : 3.19.8
-> DPDK version : 16.04
-> Pktgen version : 3.0.00
-> UIO driver for port binding

DPDK, OVS and pktgen are build using - x86_64-ivshmen-linuxapp-gcc option.

VM launched through following Qemu command :

*         qemu-system-x86_64 --enable-kvm -smp 3 -cpu host -m 2048 -chardev socket,id=charnet0,path=/var/run/openvswitch/vhost-user1 -netdev type=vhost-user,id=hostnet0,chardev=charnet0,vhostforce=on -device virtio-net-pci,netdev=hostnet0,mac=16:fa:13:26:31:1b -object memory-backend-file,id=mem,size=2048M,mem-path=/dev/hugepages,share=on -numa node,memdev=mem -mem-prealloc -hda /home/aricent/ubuntu_15_04.img

Pktgen is launched using following command:
                Pktgen -c -0x3 -n 4 -m 512 -b 000:00:04.0 - p 0x3 -t -m "[1:1].0"

OVS command used:

*         /usr/sbin/ovs-vswitchd --dpdk -c 0xc -n 4 -m 2048 -- unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --mlockall --no-chdir --log-file=/var/log/openvswitch/ovs-vswitchd.log --pidfile=/var/run/openvswitch/ovs-vswitchd.pid --detach -monitor

Thanks & Regards
Abhishek
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