The document discusses pipeline architecture and describes:
1. The difference between run-to-completion and pipeline software models, where pipeline models disperse packets to other cores for processing.
2. How the Intel DPDK Packet Framework can be used to rapidly develop packet processing applications using standard pipeline blocks like ports, tables, and a pipeline configuration API.
3. How the DPDK Packet Demonstrators (DPPD) provide sample applications and configurations to analyze performance and find bottlenecks in multi-core packet processing applications.
3. Network Platforms Group 3
Run-to-completion vs pipeline software models
Processor 0
Physical
Core 0
Linux* Control Plane
NUMA
Pool Caches
Queue/Rings
Buffers
10 GbE
10 GbE
Physical
Core 1
Intel® DPDK
PMD Packet I/O
Packet work
Rx
Tx
Physical
Core 2
Intel® DPDK
PMD Packet I/O
Flow work
Rx
Tx
Physical
Core 3
Intel® DPDK
PMD Packet I/O
Flow Classification
App A, B, C
Rx
Tx
Physical
Core 5
Intel® DPDK
PMD Packet I/O
Flow Classification
App A, B, C
Rx
Tx
Run to Completion model
• I/O and Application workload can be handled on a single core
• I/O can be scaled over multiple cores
10 GbE
Pipeline model
• I/O application disperses packets to other cores
• Application work performed on other cores
Processor 1
Physical
Core 4
Intel® DPDK
10 GbE
Physical
Core 5
Intel® DPDK
Physical
Core 0
Intel® DPDK
PMD Packet I/O
Hash
Physical
Core 1
Intel® DPDK
App A App B App C
Physical
Core 2
Intel® DPDK
App A App B App C
Physical
Core 3
Intel® DPDK
Rx
Tx
10 GbE
Physical
Core 4
Intel® DPDK
PMD Packet I/O
Flow Classification
App A, B, C
Rx
Tx
RSS
Mode
QPI
PCIePCIePCIePCIe
PCIePCIe
NUMA
Pool Caches
Queue/Rings
Buffers
Look at more I/O on
fewer cores with
vectorization
4. Network Platforms Group
Simple Pipeline application
RX (poll mode)
Validation/
Classification
Enqueue
DequeueNIC NIC
HW Thread
API
Functional
block
Async
queue
Memory pool
Mbuf
Sched. queues
p
Master core (stats)
5. Network Platforms Group 5
Pipeline applications
DPDK Packet Framework
development framework for building packet
processing applications using standard pipeline
blocks
DPPD: Data Plane Performance Demonstrators
Linux user space applications based mainly
intended for performance analysis purposes
6. DPDK Packet framework
DPDK Programmer’s Guide, Packet Framework
DPDK Sample Applications User Guide, Internet Protocol (IP) Pipeline Sample Application
7. Network Platforms Group 7
Rapid Development of Packet Processing Apps
DPDK Packet Framework quickly turns
requirements into code
8. Network Platforms Group 8
Packet Framework Components
# Component
1 Port library Port abstract interface API
Basic ports: HWQ, SWQ
Advanced ports: IP frag, IP ras, Traffic Mgr, KNI, QAT
2 Table library Table abstract interface API
Tables: Hash (Extendible bucket, LRU), ACL, LPM, Array
3 Pipeline library Pipeline configuration and run-time API
Configuration API implementation
Run-time API implementation
4 IP Pipeline
example
The Internet Protocol (IP) Pipeline application illustrates the use of
the DPDK Packet Framework tool suite by implementing functional
blocks such as packet RX, packet TX, flow classification, firewall,
routing, IP fragmentation, IP reassembly, etc which are then assigned
to different CPU cores and connected together to create complex
multi-core applications.
9. Network Platforms Group 9
DPDK Packet Framework, Pipeline Level
Ports
HW queue
SW queue
IP Fragmentation
IP Reassembly
Traffic Mgr
KNI
Source/Sink
Tables
Exact Match / Hash
Access Control List (ACL)
Longest Prefix Match (LPM)
Array
Pattern Matching
Pipeline
Port In 0
Port In 1
Port Out 0
Port Out 1
Port Out 2
Table 0
Flow #
Flow #
Flow #
Actions
Actions
Actions
Table 1
Flow #
Flow #
Flow #
Actions
Actions
Actions
Zoom in: Pipeline level
Actions
Reserved actions: Send to port,
Send to table, Drop
Packet edits: push/pop labels,
modify headers (NAT, TTL update)
Flow-based: meter, stats, app ID
Accelerators: crypto, compress
Load Balancing
librte_port
librte_table
Standard methodology for pipeline development.
Ports and tables are connected together in tree-like topologies ,
with tables providing the actions to be executed on input packets.
10. Network Platforms Group 10
DPDK Packet Framework, App Level
Pipelines
Packet I/O
Flow Classification
Firewall
Routing
Traffic Mgmt
CPU Core
Pipeline
CPU Core
Pipeline
CPU Core
Pipeline
CPU Core
P
CPU Core
Pipeline
P
Zoom out: Multi-core application level
librte_pipeline
The Framework breaks the app into multiple pipelines, assigns each pipeline
to a specific core and chains the pipelines together
11. Network Platforms Group 11
Multi-core scaling
A complex application is typically split across multiple cores, with cores
communicating through SW queues
There is usually a performance limit on the number of table lookups and
actions that can be fit on a single a single core (due to cache memory size,
cache BW, memory BW, etc.)
The Framework breaks the app into multiple pipelines, assigns each pipeline to
a specific core and chains pipelines together
One core can do more than one pipeline, but a pipeline cannot be split across
multiple cores
13. Network Platforms Group 13
Intel® DPPD: Data Plane Performance Demonstrators
An open source application
BSD3C license
Config file defines
Which cores are used
Which interfaces are used
Which tasks are executed and how configured
Allows to
Find bottlenecks and measure performance
Try and compare different core layouts without changing code
Reuse config file on different systems (CPUs, hyper-threads, sockets, interfaces)
14. Network Platforms Group 14
DPPD: Sample Configurations
Very simple port forwarding Simple load balancer and worker thread