lab exercises

Programming Multi-Core Processors based

Embedded Systems

A Hands-On Experience on Cavium Octeon based Platforms

Lab Exercises

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Lab # 1: Parallel Programming and

Performance measurement using MPAC

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Lab Goals

Objective Performance measurement using MPAC

benchmarks Learning parallel programming using MPAC

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MPAC fork and join infrastructure

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Lab # 2: Parallel Sort using MPAC

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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

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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)

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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)

Dr. Abdul WaheedCopyright © 2009 5-9

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

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Lab # 3-5: Packet Sniffing Labs

An overview

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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.

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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

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Prerequisites

Testing You can use loop back device as a network

interface Use Netperf or Mpac for traffic generation

on the network interface

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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

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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

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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

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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

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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

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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

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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