NGN Progress Report. Table of Contents
|
|
- Meryl Kelly
- 5 years ago
- Views:
Transcription
1 NGN Progress Report Title: Simulator Scalability Testing Prepared by: Richard Nelson Date: 08 February, 2006 Table of Contents Introduction...2 Simulators...2 Test Method...2 Simulation Model...2 CPU Utilisation...2 Memory Utilisation...3 Results...4 NS2...4 J-Sim...5 Omnet Comparisons...7 Limitations of the Tests...8 Conclusions...8 References...8 Page 1 1/06/2006
2 Introduction In anticipation that simulations of significant portions, or possibly all of Telecom NZ's network might be required, the scalability properties of simulators was investigated. Literature review showed that there has been little work done in this area [1] and so direct testing of suitable simulators was undertaken. Simulators The requirements for simulators to be selected were that: tools Source code be available so that they could be linked to memory allocation profiling The simulations be script able so that multiple runs could be automated The simulators be currently supported The simulators that met these criteria and were tested were NS2, J-Sim and Omnet++. Test Method Simulation Model A basic dumbell model was used with two routers connected by a single bottleneck link. Each router has an equal number of end nodes directly connected to it. In the simulations unidirectional TCP connections were formed from each node at one end of the dumbell to the corresponding node at the other end and greedy agents sent as much data as possible for the duration of the simulation run. To test performance scaling two sets of runs were performed, one with a varying number of nodes on each end and a fixed bandwidth on the bottleneck link. This kept the traffic approximately equal. The second set used a fixed number of nodes and links and varied the bandwidth of the bottleneck link. The parameters for the simulation runs were: Number of nodes on each end of the dumbell: fixed runs 200, variable runs Bandwidth of router - router link: fixed runs 100 Mb/s, variable runs 1, 10, 100, 1000, Mb/s Delay of router-router link: all runs 10ms Bandwidth of router end node links: all runs 10 Mb/s Delay of router end node links: all runs 1ms Router queue sizes: 250 packets Router queue discipline: Drop-tail Simulation time for each run: 10sec CPU Utilisation CPU utilisation was measured using the Linux time command. This provides system and user CPU time utilisation. The number of packets transmitted on the network was counted and the packets per CPU second calculated. Page 2 1/06/2006
3 To count the number of packets sent, an extra simulation was performed where a trace file detailing every simulation event across the bottleneck link was created. This file was then parsed, counting every 'enqueue' event at the client-side router, which means that a packet has passed the bottleneck successfully. The final count was then divided by the CPU time previously calculated to get packets per CPU second. Memory Utilisation Memory utilisation was measured with two heap profiling tools; one for Java and one for C. NS2's memory usage was profiled using a tool developed within WAND that replaced the standard C memory management functions, e.g. malloc, free, realloc, with custom functions that kept track of the current heap size and a list of individual allocations. Whenever new memory is allocated, a new allocation is added to the list and the current heap size is increased by the appropriate amount. An allocation is identified by the address of the first byte and the size. Whenever memory is deallocated, the original allocation is looked up in the list and the current heap size is decreased by the value of the size attribute. Approximately every second, the current heap size is written out to a file. At the conclusion of the simulation, the file is parsed to find the maximum heap usage which is used to construct the graphs below. J-sim's memory usage was profiled with SimpleProfiler a java based heap profiler ( Page 3 1/06/2006
4 Results NS2 Memory Utilisation CPU Utilisation Packets per CPU second Page 4 1/06/2006
5 J-Sim Memory Utilisation CPU Utilisation Packets per CPU second Page 5 1/06/2006
6 Omnet++ Memory Utilisation CPU Utilisation Packets per CPU second Page 6 1/06/2006
7 Comparisons CPU usage Memory Usage Packets per CPU second Page 7 1/06/2006
8 Limitations of the Tests Model limitations No starting and stopping of connections. No control or deliberate selection of the routing system used. Routing tables may occupy significant memory when large numbers of nodes are used. This will be dependent on the topology. Test tool limitations CPU utilisation is limited by Linux process accounting which (in common with most OS) is limited to jiffy resolution. Due to use of 1ms jiffy's on 2.6 series Linux kernels, this is not considered a significant limitation. Memory testing only checks heap allocation, not stack allocation. Counting of packets only takes place at a fixed location rather than across the entire topology as this was too difficult to do for some simulators. Conclusions The results show that J sim is very efficient on memory utilisation. This is due to the automatic garbage collection provided by Java. The price paid for this is the very high CPU usage to perform the garbage collection. As a result J-sim is reduced to a very small packet per second rate as the number of connections climbs towards Of the C-based simulators Omnet++ is significantly more memory efficient than NS-2 as the simulation size grows to 1000 connections. NS2 is more CPU efficient for small simulations, but not large. The differences appear to be due to the default routing algorithm used by NS2. It allocates an NxN table of routes with N being a power of 2. This provides a direct route lookup for every node in the simulation but requires significant amounts of memory as N grows large. The effect of this can be seen in the steps in the graphs of memory utilisation for N. Looking up larger tables requires more processing resulting in similar steps in the CPU usage and steps down in the packets per CPU second. Alternative routing algorithms are available in the NS2 source, but they are poorly documented and our efforts to get them working have failed. They should remove the steps from the graph, but the slope of the memory utilisation graph is higher for NS2 than Omnet++ so it will likely still use more memory. It may also use more CPU although this may scale better. References [1] Simulating Large Networks How Big is Big Enough? George F. Riley and Mostafa H. Ammar. In First International Conference on Grand Challenges for Modeling and Simulation, ICGCMS, January Page 8 1/06/2006
LANGUAGE RUNTIME NON-VOLATILE RAM AWARE SWAPPING
Technical Disclosure Commons Defensive Publications Series July 03, 2017 LANGUAGE RUNTIME NON-VOLATILE AWARE SWAPPING Follow this and additional works at: http://www.tdcommons.org/dpubs_series Recommended
More informationProcesses and Tasks What comprises the state of a running program (a process or task)?
Processes and Tasks What comprises the state of a running program (a process or task)? Microprocessor Address bus Control DRAM OS code and data special caches code/data cache EAXEBP EIP DS EBXESP EFlags
More informationPerformance Analysis of Java Communications with and without CORBA
Performance Analysis of Java Communications with and without CORBA Victor Giddings victor.giddings@ois.com 3 Objective Interface Systems, Inc. Purpose Analyze performance of various Java-based distribution
More informationHeap Management portion of the store lives indefinitely until the program explicitly deletes it C++ and Java new Such objects are stored on a heap
Heap Management The heap is the portion of the store that is used for data that lives indefinitely, or until the program explicitly deletes it. While local variables typically become inaccessible when
More informationInvestigating the Use of Synchronized Clocks in TCP Congestion Control
Investigating the Use of Synchronized Clocks in TCP Congestion Control Michele Weigle (UNC-CH) November 16-17, 2001 Univ. of Maryland Symposium The Problem TCP Reno congestion control reacts only to packet
More informationPerformance of Various Levels of Storage. Movement between levels of storage hierarchy can be explicit or implicit
Memory Management All data in memory before and after processing All instructions in memory in order to execute Memory management determines what is to be in memory Memory management activities Keeping
More informationCSCE Operating Systems Non-contiguous Memory Allocation. Qiang Zeng, Ph.D. Fall 2018
CSCE 311 - Operating Systems Non-contiguous Memory Allocation Qiang Zeng, Ph.D. Fall 2018 Big picture Fixed partitions Dynamic partitions Buddy system Contiguous allocation: Each process occupies a contiguous
More informationCIS Operating Systems Non-contiguous Memory Allocation. Professor Qiang Zeng Spring 2018
CIS 3207 - Operating Systems Non-contiguous Memory Allocation Professor Qiang Zeng Spring 2018 Big picture Fixed partitions Dynamic partitions Buddy system Contiguous allocation: Each process occupies
More informationCIS Operating Systems Memory Management. Professor Qiang Zeng Fall 2017
CIS 5512 - Operating Systems Memory Management Professor Qiang Zeng Fall 2017 Previous class Uniprocessor policies FCFS, Shortest Job First Round Robin Multilevel Feedback Queue Multiprocessor policies
More informationBuilding a Fast, Virtualized Data Plane with Programmable Hardware. Bilal Anwer Nick Feamster
Building a Fast, Virtualized Data Plane with Programmable Hardware Bilal Anwer Nick Feamster 1 Network Virtualization Network virtualization enables many virtual networks to share the same physical network
More informationPreview. Memory Management
Preview Memory Management With Mono-Process With Multi-Processes Multi-process with Fixed Partitions Modeling Multiprogramming Swapping Memory Management with Bitmaps Memory Management with Free-List Virtual
More informationAn Integrated Experimental
An Integrated Experimental Environment for Distributed Systems and Networks B. White, J. Lepreau, L. Stoller, R. Ricci, S. Guruprasad, M. Newbold, M. Hibler, C. Barb, A. Joglekar University of Utah www.netbed.org
More informationPolicy Server and Policy Control Agent
Policy Server and Policy Control Agent IRoNet Seminar 8 th January, 2004 Piia Pulkkinen Networking Laboratory, HUT Location in the Big Picture Development environment overview Policy Server implementation
More informationCS 471 Operating Systems. Yue Cheng. George Mason University Fall 2017
CS 471 Operating Systems Yue Cheng George Mason University Fall 2017 Review: Segmentation 2 Virtual Memory Accesses o Approaches: Static Relocation Dynamic Relocation Base Base-and-Bounds Segmentation
More informationmemory management Vaibhav Bajpai
memory management Vaibhav Bajpai OS 2013 motivation virtualize resources: multiplex CPU multiplex memory (CPU scheduling) (memory management) why manage memory? controlled overlap processes should NOT
More informationAn Evaluation of Deficit Round Robin Fair Queuing Applied in Router Congestion Control
JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 18, 333-339 (2002) Short aper An Evaluation of Deficit Round Robin Fair ueuing Applied in Router Congestion Control Department of Electrical Engineering National
More informationMemory Management. Contents: Memory Management. How to generate code? Background
TDIU11 Operating systems Contents: Memory Management Memory Management [SGG7/8/9] Chapter 8 Background Relocation Dynamic loading and linking Swapping Contiguous Allocation Paging Segmentation Copyright
More informationRun-time Environments
Run-time Environments Status We have so far covered the front-end phases Lexical analysis Parsing Semantic analysis Next come the back-end phases Code generation Optimization Register allocation Instruction
More informationRun-time Environments
Run-time Environments Status We have so far covered the front-end phases Lexical analysis Parsing Semantic analysis Next come the back-end phases Code generation Optimization Register allocation Instruction
More informationLarge-Scale Network Simulation Scalability and an FPGA-based Network Simulator
Large-Scale Network Simulation Scalability and an FPGA-based Network Simulator Stanley Bak Abstract Network algorithms are deployed on large networks, and proper algorithm evaluation is necessary to avoid
More informationCS 261 Fall Mike Lam, Professor. Virtual Memory
CS 261 Fall 2016 Mike Lam, Professor Virtual Memory Topics Operating systems Address spaces Virtual memory Address translation Memory allocation Lingering questions What happens when you call malloc()?
More informationIPv6 route lookup performance and scaling
IPv6 route lookup performance and scaling Michal Kubeček SUSE Labs mkubecek@suse.cz IPv6 parity It works with IPv4 so it should also work with IPv6 IPv6 parity It works with IPv4 so it should also work
More informationBrief Overview and Background
Brief Overview and Background In this assignment you will be studying the performance behavior of TCP, using ns 2. At the end of this exercise, you should be able to write simple scripts in ns 2 as well
More informationC06: Memory Management
CISC 7310X C06: Memory Management Hui Chen Department of Computer & Information Science CUNY Brooklyn College 3/8/2018 CUNY Brooklyn College 1 Outline Recap & issues Project 1 feedback Memory management:
More informationNetwork Simulator 2. Telematica I (CdL Ing. INF) Ing. Giuseppe Piro.
Network Simulator 2 Telematica I (CdL Ing. INF) Ing. Giuseppe Piro g.piro@poliba.it 1 NS-2 Goals NS-2 is a Network Simulator - version 2 Can setup network topologies Generate packet traffic similar to
More informationDynamic Data Structures. CSCI 112: Programming in C
Dynamic Data Structures CSCI 112: Programming in C 1 It s all about flexibility In the programs we ve made so far, the compiler knows at compile time exactly how much memory to allocate for each variable
More informationMemory Management william stallings, maurizio pizzonia - sistemi operativi
Memory Management 1 summary goals and requirements techniques that do not involve virtual memory 2 memory management tracking used and free memory primitives allocation of a certain amount of memory de-allocation
More informationPERFORMANCE ANALYSIS OF AF IN CONSIDERING LINK UTILISATION BY SIMULATION WITH DROP-TAIL
I.J.E.M.S., VOL.2 (4) 2011: 221-228 ISSN 2229-600X PERFORMANCE ANALYSIS OF AF IN CONSIDERING LINK UTILISATION BY SIMULATION WITH DROP-TAIL Jai Kumar, Jaiswal Umesh Chandra Department of Computer Science
More information6 - Main Memory EECE 315 (101) ECE UBC 2013 W2
6 - Main Memory EECE 315 (101) ECE UBC 2013 W2 Acknowledgement: This set of slides is partly based on the PPTs provided by the Wiley s companion website (including textbook images, when not explicitly
More informationKathie Nichols CoDel. present by Van Jacobson to the IETF-84 Transport Area Open Meeting 30 July 2012 Vancouver, Canada
Kathie Nichols CoDel present by Van Jacobson to the IETF-84 Transport Area Open Meeting 30 July 2012 Vancouver, Canada 2 3 Sender Receiver 4 Sender Receiver 5 Sender Receiver Queue forms at a bottleneck
More informationComputer Networks. Routing Algorithms
Computer Networks Routing Algorithms Topics Routing Algorithms Shortest Path (Dijkstra Algorithm) Distance Vector Routing Count to infinity problem Solutions for count to infinity problem Link State Routing
More informationCSE 573S Protocols for Computer Networks (Spring 2005 Final Project)
CSE 573S Protocols for Computer Networks (Spring 2005 Final Project) To Investigate the degree of congestion control synchronization of window-based connections bottlenecked at the same link Kumar, Vikram
More informationThe War Between Mice and Elephants
The War Between Mice and Elephants Liang Guo and Ibrahim Matta Computer Science Department Boston University 9th IEEE International Conference on Network Protocols (ICNP),, Riverside, CA, November 2001.
More informationThe Network Layer and Routers
The Network Layer and Routers Daniel Zappala CS 460 Computer Networking Brigham Young University 2/18 Network Layer deliver packets from sending host to receiving host must be on every host, router in
More informationNetwork Simulator 2: Introduction
Network Simulator 2: Introduction Presented by Ke Liu Dept. Of Computer Science SUNY Binghamton Spring, 2006 1 NS-2 Overview 2 NS-2 Developed by UC Berkeley Maintained by USC Popular simulator in scientific
More informationNS-2 Tutorial. Kumar Viswanath CMPE 252a.
NS-2 Tutorial Kumar Viswanath CMPE 252a kumarv@cse.ucsc.edu 1 What is ns-2? ns-2 stands for Network Simulator version 2. ns-2: Is a discrete event simulator for networking research packet level simulator.
More informationDynamic Storage Allocation
6.172 Performance Engineering of Software Systems LECTURE 10 Dynamic Storage Allocation Charles E. Leiserson October 12, 2010 2010 Charles E. Leiserson 1 Stack Allocation Array and pointer A un Allocate
More informationThe design and implementation of the NCTUns network simulation engine
Simulation Modelling Practice and Theory 15 (2007) 57 81 www.elsevier.com/locate/simpat The design and implementation of the NCTUns network simulation engine S.Y. Wang *, C.L. Chou, C.C. Lin Department
More information1 What is network simulation and how can it be useful?
CESNET Technical Report 26/2003 Experience with using simulations for congestion control research Sven Ubik, ubik@cesnet.cz Jan Klaban, xklaban@quick.cz December 5, 2003 Abstract As part of the CESNET
More informationPERFVIEW..NET runtime performance and ETW event analysis tool
PERFVIEW.NET runtime performance and ETW event analysis tool OVERVIEW Formerly from Vance Morrison (.NET performance architect) Open-source Performance-analysis tool Can be used to investigate CPU and
More informationThe Controlled Delay (CoDel) AQM Approach to fighting bufferbloat
The Controlled Delay (CoDel) AQM Approach to fighting bufferbloat BITAG TWG Boulder, CO February 27, 2013 Kathleen Nichols Van Jacobson Background The persistently full buffer problem, now called bufferbloat,
More informationLinux Plumbers Conference TCP-NV Congestion Avoidance for Data Centers
Linux Plumbers Conference 2010 TCP-NV Congestion Avoidance for Data Centers Lawrence Brakmo Google TCP Congestion Control Algorithm for utilizing available bandwidth without too many losses No attempt
More informationOperating Systems. 11. Memory Management Part 3 Kernel Memory Allocation. Paul Krzyzanowski Rutgers University Spring 2015
Operating Systems 11. Memory Management Part 3 Kernel Memory Allocation Paul Krzyzanowski Rutgers University Spring 2015 1 Kernel memory The kernel also needs memory User code calls malloc kernel functions
More informationTraffic Characteristics of Bulk Data Transfer using TCP/IP over Gigabit Ethernet
Traffic Characteristics of Bulk Data Transfer using TCP/IP over Gigabit Ethernet Aamir Shaikh and Kenneth J. Christensen Department of Computer Science and Engineering University of South Florida Tampa,
More informationMaking TCP more Robust against Packet Reordering
Making TCP more Robust against Packet Reordering Alexander Zimmermann Lennart Schulte TCPM, IETF-9, Honolulu, HI, USA November, 24 TCPM s feedback
More informationLAN-WAN-LAN end-to-end Network Simulation with NS2
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 17 (2018) pp 13136-13140 Research India Publications http://wwwripublicationcom LAN-WAN-LAN end-to-end Network Simulation
More informationMemory Allocation. Static Allocation. Dynamic Allocation. Dynamic Storage Allocation. CS 414: Operating Systems Spring 2008
Dynamic Storage Allocation CS 44: Operating Systems Spring 2 Memory Allocation Static Allocation (fixed in size) Sometimes we create data structures that are fixed and don t need to grow or shrink. Dynamic
More informationDropping Packets in Ubuntu Linux using tc and iptables
Dropping Packets in Ubuntu Linux using tc and... 1 Dropping Packets in Ubuntu Linux using tc and iptables By Steven Gordon on Tue, 18/01/2011-8:13pm There are two simple ways to randomly drop packets on
More informationOperating Systems. Paging... Memory Management 2 Overview. Lecture 6 Memory management 2. Paging (contd.)
Operating Systems Lecture 6 Memory management 2 Memory Management 2 Overview Paging (contd.) Structure of page table Shared memory Segmentation Segmentation with paging Virtual memory Just to remind you...
More informationQueuing. Congestion Control and Resource Allocation. Resource Allocation Evaluation Criteria. Resource allocation Drop disciplines Queuing disciplines
Resource allocation Drop disciplines Queuing disciplines Queuing 1 Congestion Control and Resource Allocation Handle congestion if and when it happens TCP Congestion Control Allocate resources to avoid
More informationOperating Systems. IV. Memory Management
Operating Systems IV. Memory Management Ludovic Apvrille ludovic.apvrille@telecom-paristech.fr Eurecom, office 470 http://soc.eurecom.fr/os/ @OS Eurecom Outline Basics of Memory Management Hardware Architecture
More informationDescription Approach Packet Loss Effect Traffic Control Experimentation Conclusions. Mice and Elephants. Ioannis Giannoualtos
Mice and Elephants Ioannis Giannoualtos Master in System and Network Engineering July 3, 2013 Why? Google showed high and stable utilisation of the links in their G-network. However : Google has full control
More informationProtecting Network Quality of Service Against Denial of Service Attacks
Protecting Network Quality of Service Against Denial of Service Attacks Douglas S. Reeves Peter Wurman NC State University S. Felix Wu U.C. Davis Dan Stevenson Xiaoyong Wu MCNC DARPA FTN PI Meeting January
More information7 Performance measurements
15 7 Performance measurements In this Chapter, we present our performance measurements. In the first measurement, we determine the impact of the Web service overhead on web servers and mobile clients.
More informationVirtual to physical address translation
Virtual to physical address translation Virtual memory with paging Page table per process Page table entry includes present bit frame number modify bit flags for protection and sharing. Page tables can
More informationIX: A Protected Dataplane Operating System for High Throughput and Low Latency
IX: A Protected Dataplane Operating System for High Throughput and Low Latency Belay, A. et al. Proc. of the 11th USENIX Symp. on OSDI, pp. 49-65, 2014. Reviewed by Chun-Yu and Xinghao Li Summary In this
More informationHigh bandwidth, Long distance. Where is my throughput? Robin Tasker CCLRC, Daresbury Laboratory, UK
High bandwidth, Long distance. Where is my throughput? Robin Tasker CCLRC, Daresbury Laboratory, UK [r.tasker@dl.ac.uk] DataTAG is a project sponsored by the European Commission - EU Grant IST-2001-32459
More informationPerformance Enhancement Of TCP For Wireless Network
P a g e 32 Vol. 10 Issue 12 (Ver. 1.0) October 2010 Global Journal of Computer Science and Technology Performance Enhancement Of TCP For Wireless Network 1 Pranab Kumar Dhar, 2 Mohammad Ibrahim Khan, 3
More informationUNIT III MEMORY MANAGEMENT
UNIT III MEMORY MANAGEMENT TOPICS TO BE COVERED 3.1 Memory management 3.2 Contiguous allocation i Partitioned memory allocation ii Fixed & variable partitioning iii Swapping iv Relocation v Protection
More informationDesign Issues 1 / 36. Local versus Global Allocation. Choosing
Design Issues 1 / 36 Local versus Global Allocation When process A has a page fault, where does the new page frame come from? More precisely, is one of A s pages reclaimed, or can a page frame be taken
More informationChapter 8 & Chapter 9 Main Memory & Virtual Memory
Chapter 8 & Chapter 9 Main Memory & Virtual Memory 1. Various ways of organizing memory hardware. 2. Memory-management techniques: 1. Paging 2. Segmentation. Introduction Memory consists of a large array
More informationModel-based Measurements Of Network Loss
Model-based Measurements Of Network Loss June 28, 2013 Mirja Kühlewind mirja.kuehlewind@ikr.uni-stuttgart.de Universität Stuttgart Institute of Communication Networks and Computer Engineering (IKR) Prof.
More informationAgenda Process Concept Process Scheduling Operations on Processes Interprocess Communication 3.2
Lecture 3: Processes Agenda Process Concept Process Scheduling Operations on Processes Interprocess Communication 3.2 Process in General 3.3 Process Concept Process is an active program in execution; process
More informationKey Performance Metrics Exposed in EdgeSight for XenApp 5.0 and EdgeSight for Endpoints 5.0
White Paper Key Performance Metrics Exposed in EdgeSight for XenApp 5.0 and EdgeSight for Endpoints 5.0 EdgeSight Archtectural Overview EdgeSight for XenApp is implemented as an agent based solution for
More informationVariable Step Fluid Simulation for Communication Network
Variable Step Fluid Simulation for Communication Network Hongjoong Kim 1 and Junsoo Lee 2 1 Korea University, Seoul, Korea, hongjoong@korea.ac.kr 2 Sookmyung Women s University, Seoul, Korea, jslee@sookmyung.ac.kr
More informationProcess. Heechul Yun. Disclaimer: some slides are adopted from the book authors slides with permission
Process Heechul Yun Disclaimer: some slides are adopted from the book authors slides with permission 1 Recap OS services Resource (CPU, memory) allocation, filesystem, communication, protection, security,
More informationA.Arpaci-Dusseau. Mapping from logical address space to physical address space. CS 537:Operating Systems lecture12.fm.2
UNIVERSITY of WISCONSIN-MADISON Computer Sciences Department CS 537 A. Arpaci-Dusseau Intro to Operating Systems Spring 2000 Dynamic Memory Allocation Questions answered in these notes When is a stack
More informationCS61C : Machine Structures
inst.eecs.berkeley.edu/~cs61c/su06 CS61C : Machine Structures Lecture #6: Memory Management CS 61C L06 Memory Management (1) 2006-07-05 Andy Carle Memory Management (1/2) Variable declaration allocates
More informationResource allocation in networks. Resource Allocation in Networks. Resource allocation
Resource allocation in networks Resource Allocation in Networks Very much like a resource allocation problem in operating systems How is it different? Resources and jobs are different Resources are buffers
More informationDynamic Memory: Alignment and Fragmentation
Dynamic Memory: Alignment and Fragmentation Learning Objectives Explain the purpose of dynamic memory Define the terms arena, heap Identify common errors involving dynamic memory Explain how dynamic memory
More informationLighting the Blue Touchpaper for UK e-science - Closing Conference of ESLEA Project The George Hotel, Edinburgh, UK March, 2007
Working with 1 Gigabit Ethernet 1, The School of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL UK E-mail: R.Hughes-Jones@manchester.ac.uk Stephen Kershaw The School of Physics
More informationCS 550 Operating Systems Spring Memory Management: Paging
CS 550 Operating Systems Spring 2018 Memory Management: Paging 1 Recap: Memory Management Ideally programmers want memory that is large fast non volatile Memory hierarchy small amount of fast, expensive
More informationMemory Management. Dr. Yingwu Zhu
Memory Management Dr. Yingwu Zhu Big picture Main memory is a resource A process/thread is being executing, the instructions & data must be in memory Assumption: Main memory is infinite Allocation of memory
More informationJiST Java in Simulation Time An efficient, unifying approach to simulation using virtual machines
JiST Java in Simulation Time An efficient, unifying approach to simulation using virtual machines Rimon Barr, Zygmunt Haas, Robbert van Renesse rimon@acm.org haas@ece.cornell.edu rvr@cs.cornell.edu. Cornell
More informationSo far. Next: scheduling next process from Wait to Run. 1/31/08 CSE 30341: Operating Systems Principles
So far. Firmware identifies hardware devices present OS bootstrap process: uses the list created by firmware and loads driver modules for each detected hardware. Initializes internal data structures (PCB,
More informationHigh Performance Packet Processing with FlexNIC
High Performance Packet Processing with FlexNIC Antoine Kaufmann, Naveen Kr. Sharma Thomas Anderson, Arvind Krishnamurthy University of Washington Simon Peter The University of Texas at Austin Ethernet
More informationReplicate It! Scalable Content Delivery: Why? Scalable Content Delivery: How? Scalable Content Delivery: How? Scalable Content Delivery: What?
Accelerating Internet Streaming Media Delivery using Azer Bestavros and Shudong Jin Boston University http://www.cs.bu.edu/groups/wing Scalable Content Delivery: Why? Need to manage resource usage as demand
More informationCS420: Operating Systems
Main Memory James Moscola Department of Engineering & Computer Science York College of Pennsylvania Based on Operating System Concepts, 9th Edition by Silberschatz, Galvin, Gagne Background Program must
More informationStatic Routing NETWORK INFRASTRUCTURES NETKIT - LECTURE 4 MANUEL CAMPO, MARCO SPAZIANI
Static Routing NETWORK INFRASTRUCTURES NETKIT - LECTURE 4 MANUEL CAMPO, MARCO SPAZIANI Routing Routing is the process of selecting a path for traffic in a network. This process defines the shortest or
More informationECE 598 Advanced Operating Systems Lecture 10
ECE 598 Advanced Operating Systems Lecture 10 Vince Weaver http://www.eece.maine.edu/~vweaver vincent.weaver@maine.edu 17 February 2015 Announcements Homework #1 and #2 grades, HW#3 Coming soon 1 Various
More informationQuality of Service Mechanism for MANET using Linux Semra Gulder, Mathieu Déziel
Quality of Service Mechanism for MANET using Linux Semra Gulder, Mathieu Déziel Semra.gulder@crc.ca, mathieu.deziel@crc.ca Abstract: This paper describes a QoS mechanism suitable for Mobile Ad Hoc Networks
More informationExploiting the Behavior of Generational Garbage Collector
Exploiting the Behavior of Generational Garbage Collector I. Introduction Zhe Xu, Jia Zhao Garbage collection is a form of automatic memory management. The garbage collector, attempts to reclaim garbage,
More informationBenchmarking results of SMIP project software components
Benchmarking results of SMIP project software components NAILabs September 15, 23 1 Introduction As packets are processed by high-speed security gateways and firewall devices, it is critical that system
More informationRecall: Address Space Map. 13: Memory Management. Let s be reasonable. Processes Address Space. Send it to disk. Freeing up System Memory
Recall: Address Space Map 13: Memory Management Biggest Virtual Address Stack (Space for local variables etc. For each nested procedure call) Sometimes Reserved for OS Stack Pointer Last Modified: 6/21/2004
More informationChapter 1 Introduction
Emerging multimedia, high-speed data, and imaging applications are generating a demand for public networks to be able to multiplex and switch simultaneously a wide spectrum of data rates. These networks
More informationComputer Memory. Data Structures and Algorithms CSE 373 SP 18 - KASEY CHAMPION 1
Computer Memory Data Structures and Algorithms CSE 373 SP 18 - KASEY CHAMPION 1 Warm Up public int sum1(int n, int m, int[][] table) { int output = 0; for (int i = 0; i < n; i++) { for (int j = 0; j
More informationJump Tables A jump table is essentially a list of places in the code to jump to. This can be thought of in C as an array of function pointers. In Asse
: Some very useful data structures commonly used in embedded systems programming (Jump tables, Circular buffers, Linked lists, Stacks and queues, Memory pools) Spring 2016 : Some very useful data structures
More informationMassive Multi-Player - Advanced Technology and Integration Solutions OpenSkies Network Fabric
1 Massive Multi-Player - Advanced Technology and Integration Solutions OpenSkies Network Fabric Fusing diverse and disparate entities/events into one holistic and operational scenario, with scalability
More informationLecture 14: Congestion Control"
Lecture 14: Congestion Control" CSE 222A: Computer Communication Networks Alex C. Snoeren Thanks: Amin Vahdat, Dina Katabi Lecture 14 Overview" TCP congestion control review XCP Overview 2 Congestion Control
More informationMemory Management. Today. Next Time. Basic memory management Swapping Kernel memory allocation. Virtual memory
Memory Management Today Basic memory management Swapping Kernel memory allocation Next Time Virtual memory Midterm results Average 68.9705882 Median 70.5 Std dev 13.9576965 12 10 8 6 4 2 0 [0,10) [10,20)
More informationTHE NETWORK PERFORMANCE OVER TCP PROTOCOL USING NS2
THE NETWORK PERFORMANCE OVER TCP PROTOCOL USING NS2 Ammar Abdulateef Hadi, Raed A. Alsaqour and Syaimak Abdul Shukor School of Computer Science, Faculty of Information Science and Technology, University
More informationImpact of bandwidth-delay product and non-responsive flows on the performance of queue management schemes
Impact of bandwidth-delay product and non-responsive flows on the performance of queue management schemes Zhili Zhao Dept. of Elec. Engg., 214 Zachry College Station, TX 77843-3128 A. L. Narasimha Reddy
More informationCPS311 Lecture: Procedures Last revised 9/9/13. Objectives:
CPS311 Lecture: Procedures Last revised 9/9/13 Objectives: 1. To introduce general issues that any architecture must address in terms of calling/returning from procedures, passing parameters (including
More informationMulticast and Quality of Service. Internet Technologies and Applications
Multicast and Quality of Service Internet Technologies and Applications Aims and Contents Aims Introduce the multicast and the benefits it offers Explain quality of service and basic techniques for delivering
More informationZing Vision. Answering your toughest production Java performance questions
Zing Vision Answering your toughest production Java performance questions Outline What is Zing Vision? Where does Zing Vision fit in your Java environment? Key features How it works Using ZVRobot Q & A
More informationOverview. TCP & router queuing Computer Networking. TCP details. Workloads. TCP Performance. TCP Performance. Lecture 10 TCP & Routers
Overview 15-441 Computer Networking TCP & router queuing Lecture 10 TCP & Routers TCP details Workloads Lecture 10: 09-30-2002 2 TCP Performance TCP Performance Can TCP saturate a link? Congestion control
More informationChapter 4. Routers with Tiny Buffers: Experiments. 4.1 Testbed experiments Setup
Chapter 4 Routers with Tiny Buffers: Experiments This chapter describes two sets of experiments with tiny buffers in networks: one in a testbed and the other in a real network over the Internet2 1 backbone.
More informationCS252 S05. Main memory management. Memory hardware. The scale of things. Memory hardware (cont.) Bottleneck
Main memory management CMSC 411 Computer Systems Architecture Lecture 16 Memory Hierarchy 3 (Main Memory & Memory) Questions: How big should main memory be? How to handle reads and writes? How to find
More informationEfficient IP-Address Lookup with a Shared Forwarding Table for Multiple Virtual Routers
Efficient IP-Address Lookup with a Shared Forwarding Table for Multiple Virtual Routers ABSTRACT Jing Fu KTH, Royal Institute of Technology Stockholm, Sweden jing@kth.se Virtual routers are a promising
More informationSimple Data Link Protocols
Simple Data Link Protocols Goals 1) Become familiar with Network Simulator 2 2) Simulate Stop & wait and Sliding Window 3) Investigate the effect of channel with loss on link utilization Introduction Data
More information