DPDK aims to improve network performance in OpenStack by reducing latency. The hypervisor was not designed for network functions and introduces bottlenecks through interrupts and copying. DPDK runs in userspace and uses poll mode drivers to bypass the kernel for packet processing, improving throughput. A proof of concept showed DPDK-accelerated Open vSwitch handled over 30Gbps of traffic with low CPU usage, compared to normal OVS which topped out at 10Gbps. While the test had limitations, DPDK offers potential to accelerate features like SR-IOV, VMQ, and offloads.

1. DPDK &Openstack
why?
Team 3

2. Why?
 Too many logical devices make “Latency” “Latency” “Latency”.
 Hypervisor wasn’t designated to support network functions!
 Device service routine works with Interrupt!
Linux Bridge
OVS Bridge
Namespace
Tap Device
Encapsulation
DVR
Neutron Node
OVSTunnel Bridge
External Bridge

3. Bottleneck ?
Networking
Application #2
Networking
Application #1
LPC?TCP? UDP?That’s ok. I assume it just “mem copy”.
Software Interrupt

4. Bottleneck ?
NIC : Buffer
Kernel
Device
Driver
Interrupt > Interrupt Service Routine > DPC
Networking
Application
APC > Networking Application
Interrupt

5. DPDK?
 Data Plan Developer Kit
 DPDK is a set of software libraries and Ethernet drivers (native and
virtualized) that run in Linux user space to boost packet processing
throughput on Intel® architecture.

6. Support
 Investment!

7. Proof of
concept
 Hardware : IBM PureFlex
 Spec
 Host - 16core / 256G / 10g nic * 2ea
 Guest – 8core / 32G / virtio nic * 2ea
=> CPU Socket Isolation & NUMA
• Software
 Iperf
 dpdk-ovs
 virtio-net-pmd

8. Proof of
concept
Host
Guest
KVM KVM
dpdk-ovs
virtio-net-pmd
Guest
virtio-net-pmd
Iperf server Iperf client

9. Conclusion
0
10000
20000
30000
40000
non with DPDK
intr/sec
0
10
20
30
Bridge OVS OVS with
DPDK
Gbps/sec
cpu usage
Iperf server

10. Self-reflection
 Something strange..
 cause
 ShortTime
 Side effect
 Low experience

11. Anyway…  PMD = “Poll Mode Driver”

12. Acceleration
features
 SR-IOV
 VMQ / DVMQ
 RSS / vRSS
 Jumbo Frame
 Large Send Offload
 Checksum Offload
 RDMA
 DCB
 DatacenterTCP (ECN)
 RSC (Receive Segment Coalescing)
 NVGRE/VXLAN offload

13. Thank you