Lab Exercises

Programming Multi-Core Processors based

Embedded Systems

A Hands-On Experience on Cavium Octeon based Platforms

Lab Exercises

Dr. Abdul WaheedCopyright © 2009 5-2

Lab # 1: Parallel Programming and

Performance measurement using MPAC


Lab Goals

Objective Performance measurement using MPAC

benchmarks Learning parallel programming using MPAC


MPAC fork and join infrastructure


Lab # 2: Parallel Sort using MPAC


Lab Goals

Parallel Sorting This lab implements two parallel sorting

algorithm Quick sort Bucket Sort

Objective Partitioning of data array Worker threads sorting partitioned array Merge partitioned arrays Performance measurements


Parallel Quick Sort31 23 14 26 8 36 4 21 4 7 1 43 32 12 21 7

31 23 14 26

8 36 4 21 4 7 1 43

32 12 21 7

14 23 26 31

4 8 21 36 1 4 7 43

7 12 21 32

14 23 26 31 4 8 21 36 1 4 7 43 7 12 21 32

1 4 4 7 7 8 12 14 21 21 23 26 31 32 36 43

Thread Function

(1)

(2)

(3)

(4)


Parallel Bucket Sort

14 21 12 21 31 23 26 32

36 43

1 4 4 7

12 14 21 21 23 26 31 32

7 8 36 43

1 4 4 7 7 8 12 14 21 21 23 26 31 32 36 43

Thread Function

31 23 14 26 8 36 4 21 4 7 1 43 32 12 21 7

1 - 11 12 - 22 23 - 33 34 - 44

8 4 4 7 1 7

(1)

(2)

(3)

(4)


Performance MeasurementQuick Sort

020406080

100120140160180200

1 2 3 4 5 6 7 8

No. of Threads

Ela

pse

d T

ime

(sec

onds)

Bucket Sort

0

5

10

15

20

25

30

35

1 2 3 4 5 6 7 8

No. of Threads

Ela

pse

d T

ime

(sec

onds)

Observations Observe the decreasing elapsed time indicating

increase in performance with increasing number of threads

Bucker Sort more efficient than Quick Sort


Lab # 3-5: Packet Sniffing Labs

An overview


Lab Goals

Objective Learning parallel programming using

threads Utilizing many core systems efficiently Performance measurement

Packet capture / filter / analyze - A case study We will use a series of labs to achieve our

objectives.


Prerequisites

Sniffing Capturing of network packets arriving or

departing from a network interface Mechanism

We use raw sockets as followsrawSock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL))

This system call picks every packet going out or coming in on an Ethernet interface


Prerequisites

Testing You can use loop back device as a network

interface Use Netperf or Mpac for traffic generation

on the network interface


Packet Capturing on Many Core

0 2 4 6 8 10 12 14

1 3 5 7 9 11 13 15

Sender

Receiver

Packet Sniffer

Core

CPU Affinity

DataDedicated Cores


Sniffing Labs Framework

Sniffing One thread, called the dispatcher, sniffs the

packets from the interface and puts it in one of the workers’ queues

Filtering / Analysis Any kind of processing on a packet is the

responsibility of the workers Each worker has its own queue Dispatcher assigns packets to worker

queues


Lab 3 – Packet Sniffing

Sniff a frame This lab captures Ethernet packets which

are destined to or departing from a specific interface

Objective Can a dispatcher sniff at the line rate Hands on experience of plain sniffing Observing the base case performance of the

dispatcher – worker model


Lab 4 – Packet Filtering

Objective Use different packet header information to

sniff specific type of packets Mechanism

Dispatcher will sniff frames and will put in worker queues in round-robin fashion

User will specify source IP, destination IP, source port and destination port for filtering in TCP packets


Lab 4 – Packet Filtering

Mechanism Each worker will process packets residing in

its queues Observations

Observe the throughput performance with increasing number of threads

Compare the throughput with lab 3 throughput

Use core affinity and observe throughput


Lab 5 – Deep Packet Inspection Objective

A user provided string will be searched in the TCP based application payload

Mechanisms Same as Lab 4 except each worker now

finds a string in the application payload String to find is provided by the user


Lab 5 – Deep Packet Inspection Observations

Observe the throughput performance with increasing number of threads

Compare the throughput with lab 3 and 4 throughput

Use core affinity and observer performance

Documents

Lab Exercises