CSCE 313 Introduction to Computer Systems. Instructor: Dezhen Song
|
|
- Moses Atkinson
- 6 years ago
- Views:
Transcription
1 CSCE 313 Introduction to Computer Systems Instructor: Dezhen Song
2 Schedulers in the OS CPU Scheduling Structure of a CPU Scheduler Scheduling = Selection + Dispatching Criteria for scheduling Scheduling Algorithms FIFO/FCFS SPF / SRTF Priority - Based
3 Schedulers start long-term (admission) scheduler short-term (CPU) scheduler suspended ready ready running suspended blocked blocked medium-term (memory) scheduler
4 Focus: Short-Term Scheduling Recall: Motivation for multiprogramming -- have multiple processes in memory to keep CPU busy. Typical execution profile of a process/thread: start terminate wait for I/O wait for I/O wait for I/O CPU burst CPU burst CPU burst CPU burst CPU scheduler is managing the execution of CPU bursts, represented by processes in ready or running state.
5 non-preemptive preemptive Scheduling Decisions Who is going to use the CPU next?! ready 4 running waiting Scheduling decision points: 1. The running process changes from running to waiting (current CPU burst of that process is over). 2. The running process terminates. 3. A waiting process becomes ready (new CPU burst of that process begins). 4. The current process switches from running to ready.
6 Structure of a Scheduler ready queue PCB scheduler dispatcher CPU select process restart executing process?
7 What Is a Good Scheduler? Criteria User oriented: Turnaround time : time interval from submission of job until its completion Waiting time : sum of periods spent waiting in ready queue Response time : time interval from submission of job to first response Normalized turnaround time: ratio of turnaround time to service time System oriented: CPU utilization : percentage of time CPU is busy Throughput : number of jobs completed per time unit Any good scheduler should: maximize CPU utilization and throughput minimize turnaround time, waiting time, response time Huh? maximum/minimum values vs. average values vs. variance
8 Scheduling Algorithms FCFS : First-come-first-served SPN/SJF: Shortest Process Next/Shortest Job First SRT: Shortest Remaining Time priority scheduling RR : Round-robin MLFQ: Multilevel feedback queue scheduling Multiprocessor scheduling
9 First-Come-First-Served (FCFS/FIFO) append at the end of queue head tail PCB CPU Advantages: very simple Disadvantages: long average and worst-case waiting times poor dynamic behavior (convoy effect): many other processes may wait for one big process to get off the CPU
10 FCFS Scheduling (cont) Process Burst Time P 1 24 P 2 3 P 3 3 Suppose that the processes arrive in the order: P 1, P 2, P 3 The Gantt Chart for the schedule is: 0 P 1 P 2 P 3 Waiting time for P 1 = 0; P 2 = 24; P 3 = 27 Average waiting time: ( )/3 = 17 Average response time: ( )/3=17 Average turnaround time: ( )/3=
11 FCFS Scheduling (cont) Suppose that the processes arrive in the order P 2, P 3, P 1 The Gantt chart for the schedule is: P 2 P 3 P 1 0 Waiting time for P 1 = 6; P 2 = 0 ; P 3 = Average waiting time: ( )/3 = 3 Average response time? Turnaround time? Much better than previous case Convoy effect short process behind long process
12 Shortest Process Next/Shortest Job First determine location in queue (compare next CPU burst lengths) CPU long jobs short jobs Whenever CPU is idle, picks process with shortest next CPU burst. Advantages: minimizes average waiting times. (frequently used in long-term scheduling) Problem: How to determine length of next CPU burst?! Problem: Starvation of jobs with long CPU bursts.
13 Example of SJF Process Burst Time P 1 6 P 2 8 P 3 7 P 4 3 SJF scheduling chart P 4 P P 1 3 P Average waiting time = ( ) / 4 = 7 Average turnaround time? Average response time? 24
14 SJF Minimizes Average Waiting Time Provably optimal: Proof: swapping of jobs P long P short P short P long dw = t short - t long < 0 Example: W = = W = = W = = W = = W = = 32
15 Determining Length of Next CPU Burst Can only estimate the length Can be done by using the length of previous CPU bursts, using exponential averaging t n actual length of n n 1, 0 1 Define : CPU burst predicted value for the next CPU th 1. n 1 tn n burst
16 (Fixed) Priority Scheduling Selector (compare priorities) CPU low priority high priority Whenever CPU is idle, picks process with highest priority. Priority: process class, urgency, pocket depth. Unbounded blocking: Starvation Increase priority over time: aging
17 Selector (compare priorities) Selector (compare priorities) Conceptually Priority Queues low priority priority queue priority low priority q=f(p) high priority CPU high priority CPU
18 FIFO queue Round-Robin FIFO with preemption after time quantum Method for time sharing Choice of time quantum: large: FCFS small: Processor sharing Time quantum also defines context-switching overhead end of time quantum CPU terminate
19 Example of RR with Time Quantum = 4 The Gantt chart is: Process Burst Time P 1 24 P 2 3 P 3 3 P 1 P 2 P 3 P 1 P 1 P 1 P 1 P Average response time: (0+4+7)/3 = 11/3 Average turnaround time: ( )/3 = 47/3 Average waiting time: ( )/3 = 17/3 Typically, higher average turnaround than SJF, but better response
20 Time Quantum and Context Switch Time
21 Turnaround Time Varies With The Time Quantum
22 Multilevel Queue Scheduling
23 Selector (compare priorities) Multilevel Feedback Queue Scheduling (conceptually) low priority FCFS (quantum = infinity) quantum = 16 ms aging quantum = 4ms quantum = 2 ms demotion high priority
CPU scheduling. CPU Scheduling
EECS 3221 Operating System Fundamentals No.4 CPU scheduling Prof. Hui Jiang Dept of Electrical Engineering and Computer Science, York University CPU Scheduling CPU scheduling is the basis of multiprogramming
More informationModule 5: CPU Scheduling
Module 5: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation 5.1 Basic Concepts Maximum CPU utilization obtained
More informationChapter 6: CPU Scheduling
Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation 6.1 Basic Concepts Maximum CPU utilization obtained
More informationCS 550 Operating Systems Spring CPU scheduling I
1 CS 550 Operating Systems Spring 2018 CPU scheduling I Process Lifecycle Ready Process is ready to execute, but not yet executing Its waiting in the scheduling queue for the CPU scheduler to pick it up.
More informationCPU Scheduling. CPU Scheduler
CPU Scheduling These slides are created by Dr. Huang of George Mason University. Students registered in Dr. Huang s courses at GMU can make a single machine readable copy and print a single copy of each
More informationTDDI04, K. Arvidsson, IDA, Linköpings universitet CPU Scheduling. Overview: CPU Scheduling. [SGG7] Chapter 5. Basic Concepts.
TDDI4 Concurrent Programming, Operating Systems, and Real-time Operating Systems CPU Scheduling Overview: CPU Scheduling CPU bursts and I/O bursts Scheduling Criteria Scheduling Algorithms Multiprocessor
More informationLast class: Today: Threads. CPU Scheduling
1 Last class: Threads Today: CPU Scheduling 2 Resource Allocation In a multiprogramming system, we need to share resources among the running processes What are the types of OS resources? Question: Which
More informationCPU SCHEDULING RONG ZHENG
CPU SCHEDULING RONG ZHENG OVERVIEW Why scheduling? Non-preemptive vs Preemptive policies FCFS, SJF, Round robin, multilevel queues with feedback, guaranteed scheduling 2 SHORT-TERM, MID-TERM, LONG- TERM
More informationComp 204: Computer Systems and Their Implementation. Lecture 11: Scheduling cont d
Comp 204: Computer Systems and Their Implementation Lecture 11: Scheduling cont d 1 Today Scheduling algorithms continued Shortest remaining time first (SRTF) Priority scheduling Round robin (RR) Multilevel
More informationChe-Wei Chang Department of Computer Science and Information Engineering, Chang Gung University
Che-Wei Chang chewei@mail.cgu.edu.tw Department of Computer Science and Information Engineering, Chang Gung University } 2017/11/15 Midterm } 2017/11/22 Final Project Announcement 2 1. Introduction 2.
More information2/5/07 CSE 30341: Operating Systems Principles
page 1 Shortest-Job-First (SJR) Scheduling Associate with each process the length of its next CPU burst. Use these lengths to schedule the process with the shortest time Two schemes: nonpreemptive once
More informationCPU Scheduling Exercises
CPU Scheduling Exercises NOTE: All time in these exercises are in msec. Processes P 1, P 2, P 3 arrive at the same time, but enter the job queue in the order presented in the table. Time quantum = 3 msec
More informationTDDB68 Concurrent programming and operating systems. Lecture: CPU Scheduling II
TDDB68 Concurrent programming and operating systems Lecture: CPU Scheduling II Mikael Asplund, Senior Lecturer Real-time Systems Laboratory Department of Computer and Information Science Copyright Notice:
More informationReal-time operating systems course. 6 Definitions Non real-time scheduling algorithms Real-time scheduling algorithm
Real-time operating systems course 6 Definitions Non real-time scheduling algorithms Real-time scheduling algorithm Definitions Scheduling Scheduling is the activity of selecting which process/thread should
More informationScheduling I. Today Introduction to scheduling Classical algorithms. Next Time Advanced topics on scheduling
Scheduling I Today Introduction to scheduling Classical algorithms Next Time Advanced topics on scheduling Scheduling out there You are the manager of a supermarket (ok, things don t always turn out the
More informationSimulation of Process Scheduling Algorithms
Simulation of Process Scheduling Algorithms Project Report Instructor: Dr. Raimund Ege Submitted by: Sonal Sood Pramod Barthwal Index 1. Introduction 2. Proposal 3. Background 3.1 What is a Process 4.
More informationCPU Scheduling. Heechul Yun
CPU Scheduling Heechul Yun 1 Recap Four deadlock conditions: Mutual exclusion No preemption Hold and wait Circular wait Detection Avoidance Banker s algorithm 2 Recap: Banker s Algorithm 1. Initialize
More informationScheduling I. Today. Next Time. ! Introduction to scheduling! Classical algorithms. ! Advanced topics on scheduling
Scheduling I Today! Introduction to scheduling! Classical algorithms Next Time! Advanced topics on scheduling Scheduling out there! You are the manager of a supermarket (ok, things don t always turn out
More informationCHAPTER 5 - PROCESS SCHEDULING
CHAPTER 5 - PROCESS SCHEDULING OBJECTIVES To introduce CPU scheduling, which is the basis for multiprogrammed operating systems To describe various CPU-scheduling algorithms To discuss evaluation criteria
More informationProcess Scheduling. Process Scheduling. CPU and I/O Bursts. CPU - I/O Burst Cycle. Variations in Bursts. Histogram of CPU Burst Times
Scheduling The objective of multiprogramming is to have some process running all the time The objective of timesharing is to have the switch between processes so frequently that users can interact with
More informationUC Santa Barbara. Operating Systems. Christopher Kruegel Department of Computer Science UC Santa Barbara
Operating Systems Christopher Kruegel Department of Computer Science http://www.cs.ucsb.edu/~chris/ Many processes to execute, but one CPU OS time-multiplexes the CPU by operating context switching Between
More informationScheduling. Uwe R. Zimmer & Alistair Rendell The Australian National University
6 Scheduling Uwe R. Zimmer & Alistair Rendell The Australian National University References for this chapter [Bacon98] J. Bacon Concurrent Systems 1998 (2nd Edition) Addison Wesley Longman Ltd, ISBN 0-201-17767-6
More informationCSE 380 Computer Operating Systems
CSE 380 Computer Operating Systems Instructor: Insup Lee & Dianna Xu University of Pennsylvania, Fall 2003 Lecture Note 3: CPU Scheduling 1 CPU SCHEDULING q How can OS schedule the allocation of CPU cycles
More informationCS 370. FCFS, SJF and Round Robin. Yashwanth Virupaksha and Abhishek Yeluri
CS 370 FCFS, SJF and Round Robin Yashwanth Virupaksha and Abhishek Yeluri Homework-4 Review Write a C program to demonstrate the following scheduling algorithms First Come First Serve. (20 pts) Shortest
More informationDynamic Time Quantum based Round Robin CPU Scheduling Algorithm
Dynamic Time Quantum based Round Robin CPU Scheduling Algorithm Yosef Berhanu Department of Computer Science University of Gondar Ethiopia Abebe Alemu Department of Computer Science University of Gondar
More informationDesign and Performance Evaluation of a New Proposed Shortest Remaining Burst Round Robin (SRBRR) Scheduling Algorithm
Design and Performance Evaluation of a New Proposed Shortest Remaining Burst Round Robin (SRBRR) Scheduling Algorithm Prof. Rakesh Mohanty, Prof. H. S. Behera Khusbu Patwari, Manas Ranjan Das, Monisha
More informationLSN 15 Processor Scheduling
LSN 15 Processor Scheduling ECT362 Operating Systems Department of Engineering Technology LSN 15 Processor Scheduling LSN 15 FCFS/FIFO Scheduling Each process joins the Ready queue When the current process
More informationODSA: A Novel Ordering Divisional Scheduling Algorithm for Modern Operating Systems
ODSA: A Novel Ordering Divisional Scheduling Algorithm for Modern Operating Systems Junaid Haseeb Khizar Hameed Muhammad Junaid Muhammad Tayyab Samia Rehman COMSATS Institute of Information Technology,
More informationImprovising Round Robin Process Scheduling through Dynamic Time Quantum Estimation
Improvising Round Robin Process Scheduling through Dynamic Time Quantum Estimation Mr. Nischaykumar Hegde 1, Mr. Pramod Kumar P M 2 Department of Computer Science, Vivekananda College of Engineering &
More informationHalf Life Variable Quantum Time Round Robin (HLVQTRR)
Half Life Variable Quantum Time Round Robin () Simon Ashiru, Salleh Abdullahi, Sahalu Junaidu Department of Mathematics, ABU Zaria, Nigeria Abstract Round Robin (RR), one of the oldest CPU scheduling algorithms
More informationRevamped Round Robin Scheduling Algorithm
Revamped Round Robin Scheduling Chhayanath Padhy, M.Tech Student, Government College of Engineering Kalahandi, Odissa, India Dillip Ranjan Nayak, Assistant Professor, Government College of Engineering
More informationENHANCING CPU PERFORMANCE USING SUBCONTRARY MEAN DYNAMIC ROUND ROBIN (SMDRR) SCHEDULING ALGORITHM
ENHANCING CPU PERFORMANCE USING SUBCONTRARY MEAN DYNAMIC ROUND ROBIN (SMD) SCHEDULING ALGORITHM Sourav Kumar Bhoi *1, Sanjaya Kumar Panda 2 and Debashee Tarai 3 * 1 Department of Computer Science & Engineering,
More informationDETERMINING THE VARIABLE QUANTUM TIME (VQT) IN ROUND ROBIN AND IT S IMPORTANCE OVER AVERAGE QUANTUM TIME METHOD
D DETERMINING THE VARIABLE QUANTUM TIME (VQT) IN ROUND ROBIN AND IT S IMPORTANCE OVER AVERAGE QUANTUM TIME METHOD Yashasvini Sharma 1 Abstract The process scheduling, is one of the most important tasks
More informationJournal of Global Research in Computer Science
Volume 2, No. 2, February 2011 Journal of Global Research in Computer Science RESEARCH PAPER Available Online at www.jgrcs.info Design and Performance Evaluation of Multi Cyclic Round Robin (MCRR) Algorithm
More informationCOMPARATIVE PERFORMANCE ANALYSIS OF MULTI-DYNAMIC TIME QUANTUM ROUND ROBIN (MDTQRR) ALGORITHM WITH ARRIVAL TIME
COMPARATIVE PERFORMANCE ANALYSIS OF MULTI-DYNAMIC TIME QUANTUM ROUND ROBIN (MDTQRR) ALGORITHM WITH ARRIVAL TIME Abstract H. S. Behera, Rakesh Mohanty, Sabyasachi Sahu, Sourav Kumar Bhoi Dept. of Computer
More informationSeason Finale: Which one is better?
CS4310.01 Introduction to Operating System Spring 2016 Dr. Zhizhang Shen Season Finale: Which one is better? 1 Background In this lab, we will study, and compare, two processor scheduling policies via
More informationFebruary 2011 Page 23 of 93 ISSN
Design and Performance Evaluation of A New Proposed Fittest Job First Dynamic Round Robin (FJFDRR) Scheduling Algorithm Prof. Rakesh Mohanty 1 Lecturer Department of Computer Science and Engineering Veer
More informationENHANCING THE CPU PERFORMANCE USING A MODIFIED MEAN- DEVIATION ROUND ROBIN SCHEDULING ALGORITHM FOR REAL TIME SYSTEMS.
Volume 3, o. 3, March 2012 Journal of lobal Research in Computer Science RSRCH PPR vailable Online at www.jgrcs.info HC H CPU PRFORMC US MODFD M- DVO ROUD ROB SCHDUL LORHM FOR RL M SYSMS. H.s.Behera *1,
More informationReal-Time Systems. Event-Driven Scheduling
Real-Time Systems Event-Driven Scheduling Marcus Völp, Hermann Härtig WS 2013/14 Outline mostly following Jane Liu, Real-Time Systems Principles Scheduling EDF and LST as dynamic scheduling methods Fixed
More informationEXTRA THRESHOLD IN ROUND ROBIN ALGORITHM IN MULTIPROCESSOR SYSTEM
EXTRA THRESHOLD IN ROUND ROBIN ALGORITHM IN MULTIPROCESSOR SYSTEM 1 AISHWARYA ARORA, 2 HIMANSHI BHATIA 1,2 Department of Computer Science, Jamia Hamdard, New Delhi, Delhi E-mail: aishwaryaa30@gmail.com,
More informationEfficient Dual Nature Round Robin CPU Scheduling Algorithm: A Comparative Analysis
Efficient Dual Nature Round Robin CPU Scheduling Algorithm: A Comparative Analysis Sajida Fayyaz 1, Hafiz Ali Hamza 2, Saira Moin U Din 3 and Iqra 4 1-4 Department of Computer Science, University of Lahore
More informationAn Improved Round Robin Approach using Dynamic Time Quantum for Improving Average Waiting Time
An Improved Round Robin Approach using Dynamic Quantum for Improving Waiting Sandeep Negi Assistant Professor Department of Computer Science & Engineering Delhi Institute of Technology & Management ABSTRACT
More informationA new Hybridized Multilevel Feedback Queue Scheduling with Intelligent Time Slice and its Performance Analysis
A new Hybridized Multilevel Feedback Queue Scheduling with Intelligent Time Slice and its Performance Analysis H.S.Behera, Reena Kumari Naik, Suchilagna Parida Department of Computer Science and Engineering
More informationJournal of Global Research in Computer Science
Volume 2, No. 4, April 2011 Journal of Global Research in Computer Science RESEARCH ARTICLE Available Online at www.jgrcs.info PERFORMANCE EVALUATION OF A NEW PROPOSED SHOTREST EXECUTION FIRST DYNAMIC
More informationInternational Journal of Advanced Research in Computer Science and Software Engineering
Volume 2, Issue 11, November 2012 ISSN: 2277 128X International Journal of Advanced Research in Computer Science and Software Engineering Research Paper Available online at: www.ijarcsse.com A Best possible
More informationA NEW PROPOSED DYNAMIC DUAL PROCESSOR BASED CPU SCHEDULING ALGORITHM
A NEW POPOSED DYNAMIC DUAL POCESSO BASED CPU SCHEDULING ALGOITHM 1 G.SIVA NAGESWAA AO, 2 D.S.V.N. SINIVASU, 3 D. N SINIVASU, 4 D. O NAGA AJU 1 Assoc. Professor, Department of Computer Science and Engineering,
More informationNATCOR: Stochastic Modelling
NATCOR: Stochastic Modelling Queueing Theory II Chris Kirkbride Management Science 2017 Overview of Today s Sessions I Introduction to Queueing Modelling II Multiclass Queueing Models III Queueing Control
More informationReal-Time and Embedded Systems (M) Lecture 5
Priority-driven Scheduling of Periodic Tasks (1) Real-Time and Embedded Systems (M) Lecture 5 Lecture Outline Assumptions Fixed-priority algorithms Rate monotonic Deadline monotonic Dynamic-priority algorithms
More informationLecture 6. Real-Time Systems. Dynamic Priority Scheduling
Real-Time Systems Lecture 6 Dynamic Priority Scheduling Online scheduling with dynamic priorities: Earliest Deadline First scheduling CPU utilization bound Optimality and comparison with RM: Schedulability
More informationScheduling IoT on to the Cloud : A New Algorithm
European Journal of Applied Sciences 9 (5): 249-257, 2017 ISSN 2079-2077 IDOSI Publications, 2017 DOI: 10.5829/idosi.ejas.2017.249.257 Scheduling IoT on to the Cloud : A New Algorithm 1 2 3 4 S. Balamurugan,
More informationCIS 4930/6930: Principles of Cyber-Physical Systems
CIS 4930/6930: Principles of Cyber-Physical Systems Chapter 11 Scheduling Hao Zheng Department of Computer Science and Engineering University of South Florida H. Zheng (CSE USF) CIS 4930/6930: Principles
More informationENHANCING THE CPU PERFORMANCE USING A MODIFIED MEAN- DEVIATION ROUND ROBIN SCHEDULING ALGORITHM FOR REAL TIME SYSTEMS
Volume 3, o. 3, March 212 Journal of lobal esearch in Computer Science SCH PP vailable Online at www.jgrcs.info HC H CPU PFOMC US MODFD M- DVO OUD OB SCHDUL LOHM FO L M SYSMS H.s.Behera *1, Sreelipa Curtis
More informationLecture Note #6: More on Task Scheduling EECS 571 Principles of Real-Time Embedded Systems Kang G. Shin EECS Department University of Michigan
Lecture Note #6: More on Task Scheduling EECS 571 Principles of Real-Time Embedded Systems Kang G. Shin EECS Department University of Michigan Note 6-1 Mars Pathfinder Timing Hiccups? When: landed on the
More informationDetermining the Optimum Time Quantum Value in Round Robin Process Scheduling Method
I.J. Information Technology and Computer Science, 2012, 10, 67-73 Published Online September 2012 in MECS (http://www.mecs-press.org/) DOI: 10.5815/ijitcs.2012.10.08 Determining the Optimum Time Quantum
More informationReal-Time Systems. Event-Driven Scheduling
Real-Time Systems Event-Driven Scheduling Hermann Härtig WS 2018/19 Outline mostly following Jane Liu, Real-Time Systems Principles Scheduling EDF and LST as dynamic scheduling methods Fixed Priority schedulers
More informationENHANCED ROUND ROBIN ALGORITHM FOR PROCESS SCHEDULING USING VARYING QUANTUM PRECISION
ENHANCED ROUND ROBIN ALGORITHM FOR PROCESS SCHEDULING USING VARYING QUANTUM PRECISION 1 AASHNA BISHT, 2 MOHD ABDUL AHAD, 3 SIELVIE SHARMA Department of Computer Science, Jamia Hamdard, New Delhi Abstract:
More informationAperiodic Task Scheduling
Aperiodic Task Scheduling Jian-Jia Chen (slides are based on Peter Marwedel) TU Dortmund, Informatik 12 Germany Springer, 2010 2017 年 11 月 29 日 These slides use Microsoft clip arts. Microsoft copyright
More information3. Scheduling issues. Common approaches 3. Common approaches 1. Preemption vs. non preemption. Common approaches 2. Further definitions
Common approaches 3 3. Scheduling issues Priority-driven (event-driven) scheduling This class of algorithms is greedy They never leave available processing resources unutilized An available resource may
More informationPriority-driven Scheduling of Periodic Tasks (1) Advanced Operating Systems (M) Lecture 4
Priority-driven Scheduling of Periodic Tasks (1) Advanced Operating Systems (M) Lecture 4 Priority-driven Scheduling Assign priorities to jobs, based on their deadline or other timing constraint Make scheduling
More informationAnalysis of Software Artifacts
Analysis of Software Artifacts System Performance I Shu-Ngai Yeung (with edits by Jeannette Wing) Department of Statistics Carnegie Mellon University Pittsburgh, PA 15213 2001 by Carnegie Mellon University
More informationImproved Deadline Monotonic Scheduling With Dynamic and Intelligent Time Slice for Real-time Systems
Improved Deadline Monotonic Scheduling With Dynamic and Intelligent Time Slice for Real-time Systems H. S. Behera, Sushree Sangita Panda and Jana Chakraborty Department of Computer Science and Engineering,
More informationIntro to Queueing Theory
1 Intro to Queueing Theory Little s Law M/G/1 queue Conservation Law 1/31/017 M/G/1 queue (Simon S. Lam) 1 Little s Law No assumptions applicable to any system whose arrivals and departures are observable
More informationEmbedded Systems 15. REVIEW: Aperiodic scheduling. C i J i 0 a i s i f i d i
Embedded Systems 15-1 - REVIEW: Aperiodic scheduling C i J i 0 a i s i f i d i Given: A set of non-periodic tasks {J 1,, J n } with arrival times a i, deadlines d i, computation times C i precedence constraints
More informationResearch Article Designing of Vague Logic Based 2-Layered Framework for CPU Scheduler
Fuzzy Systems Volume 6, Article ID 78467, pages http://dx.doi.org/./6/78467 Research Article Designing of Vague Logic Based -Layered Framework for CPU Scheduler Supriya Raheja School of Engineering & Technology,
More informationLecture 13. Real-Time Scheduling. Daniel Kästner AbsInt GmbH 2013
Lecture 3 Real-Time Scheduling Daniel Kästner AbsInt GmbH 203 Model-based Software Development 2 SCADE Suite Application Model in SCADE (data flow + SSM) System Model (tasks, interrupts, buses, ) SymTA/S
More informationCPSC 531: System Modeling and Simulation. Carey Williamson Department of Computer Science University of Calgary Fall 2017
CPSC 531: System Modeling and Simulation Carey Williamson Department of Computer Science University of Calgary Fall 2017 Motivating Quote for Queueing Models Good things come to those who wait - poet/writer
More informationprocess arrival time CPU burst time priority p1 0ms 25ms 3 p2 1ms 9ms 1 p3 20ms 14ms 4 p4 32ms 4ms 2
Homework #2 Solutions 1. Suppose that the following processes arrive for execution at the times indicated. Each process will run with a single burst of CPU activity (i.e., no I/O) which lasts for the listed
More informationHow to deal with uncertainties and dynamicity?
How to deal with uncertainties and dynamicity? http://graal.ens-lyon.fr/ lmarchal/scheduling/ 19 novembre 2012 1/ 37 Outline 1 Sensitivity and Robustness 2 Analyzing the sensitivity : the case of Backfilling
More informationClock-driven scheduling
Clock-driven scheduling Also known as static or off-line scheduling Michal Sojka Czech Technical University in Prague, Faculty of Electrical Engineering, Department of Control Engineering November 8, 2017
More informationQueueing systems. Renato Lo Cigno. Simulation and Performance Evaluation Queueing systems - Renato Lo Cigno 1
Queueing systems Renato Lo Cigno Simulation and Performance Evaluation 2014-15 Queueing systems - Renato Lo Cigno 1 Queues A Birth-Death process is well modeled by a queue Indeed queues can be used to
More informationReal-Time Systems. Lecture #14. Risat Pathan. Department of Computer Science and Engineering Chalmers University of Technology
Real-Time Systems Lecture #14 Risat Pathan Department of Computer Science and Engineering Chalmers University of Technology Real-Time Systems Specification Implementation Multiprocessor scheduling -- Partitioned
More informationScheduling Lecture 1: Scheduling on One Machine
Scheduling Lecture 1: Scheduling on One Machine Loris Marchal October 16, 2012 1 Generalities 1.1 Definition of scheduling allocation of limited resources to activities over time activities: tasks in computer
More informationNetworked Embedded Systems WS 2016/17
Networked Embedded Systems WS 2016/17 Lecture 2: Real-time Scheduling Marco Zimmerling Goal of Today s Lecture Introduction to scheduling of compute tasks on a single processor Tasks need to finish before
More informationEmbedded Systems 14. Overview of embedded systems design
Embedded Systems 14-1 - Overview of embedded systems design - 2-1 Point of departure: Scheduling general IT systems In general IT systems, not much is known about the computational processes a priori The
More informationNon-Preemptive and Limited Preemptive Scheduling. LS 12, TU Dortmund
Non-Preemptive and Limited Preemptive Scheduling LS 12, TU Dortmund 09 May 2017 (LS 12, TU Dortmund) 1 / 31 Outline Non-Preemptive Scheduling A General View Exact Schedulability Test Pessimistic Schedulability
More informationAndrew Morton University of Waterloo Canada
EDF Feasibility and Hardware Accelerators Andrew Morton University of Waterloo Canada Outline 1) Introduction and motivation 2) Review of EDF and feasibility analysis 3) Hardware accelerators and scheduling
More informationContents Preface The Exponential Distribution and the Poisson Process Introduction to Renewal Theory
Contents Preface... v 1 The Exponential Distribution and the Poisson Process... 1 1.1 Introduction... 1 1.2 The Density, the Distribution, the Tail, and the Hazard Functions... 2 1.2.1 The Hazard Function
More informationIntroduction to Queueing Theory
Introduction to Queueing Theory Raj Jain Washington University in Saint Louis Saint Louis, MO 63130 Jain@cse.wustl.edu Audio/Video recordings of this lecture are available at: http://www.cse.wustl.edu/~jain/cse567-11/
More informationThere are three priority driven approaches that we will look at
Priority Driven Approaches There are three priority driven approaches that we will look at Earliest-Deadline-First (EDF) Least-Slack-Time-first (LST) Latest-Release-Time-first (LRT) 1 EDF Earliest deadline
More informationEmbedded Systems Development
Embedded Systems Development Lecture 3 Real-Time Scheduling Dr. Daniel Kästner AbsInt Angewandte Informatik GmbH kaestner@absint.com Model-based Software Development Generator Lustre programs Esterel programs
More informationConvolution Algorithm
Convolution Algorithm Raj Jain Washington University in Saint Louis Saint Louis, MO 63130 Jain@cse.wustl.edu Audio/Video recordings of this lecture are available at: http://www.cse.wustl.edu/~jain/cse567-08/
More informationTask Models and Scheduling
Task Models and Scheduling Jan Reineke Saarland University June 27 th, 2013 With thanks to Jian-Jia Chen at KIT! Jan Reineke Task Models and Scheduling June 27 th, 2013 1 / 36 Task Models and Scheduling
More informationOperational Laws Raj Jain
Operational Laws 33-1 Overview What is an Operational Law? 1. Utilization Law 2. Forced Flow Law 3. Little s Law 4. General Response Time Law 5. Interactive Response Time Law 6. Bottleneck Analysis 33-2
More informationCS418 Operating Systems
CS418 Operating Systems Lecture 14 Queuing Analysis Textbook: Operating Systems by William Stallings 1 1. Why Queuing Analysis? If the system environment changes (like the number of users is doubled),
More informationSection 1.2: A Single Server Queue
Section 12: A Single Server Queue Discrete-Event Simulation: A First Course c 2006 Pearson Ed, Inc 0-13-142917-5 Discrete-Event Simulation: A First Course Section 12: A Single Server Queue 1/ 30 Section
More informationProcess Scheduling for RTS. RTS Scheduling Approach. Cyclic Executive Approach
Process Scheduling for RTS Dr. Hugh Melvin, Dept. of IT, NUI,G RTS Scheduling Approach RTS typically control multiple parameters concurrently Eg. Flight Control System Speed, altitude, inclination etc..
More informationOn-line scheduling of periodic tasks in RT OS
On-line scheduling of periodic tasks in RT OS Even if RT OS is used, it is needed to set up the task priority. The scheduling problem is solved on two levels: fixed priority assignment by RMS dynamic scheduling
More informationD Praveen Kumar et al, / (IJCSIT) International Journal of Computer Science and Information Technologies, Vol. 5 (5), 2014,
Finding Best Time Quantum for Round Robin Scheduling Algorithm to avoid Frequent Context Switch D Praveen Kumar #1, T. Sreenivasula Reddy *2, A. Yugandhar Reddy *3 # Assistant Professor, Department of
More informationAnalysis of Round-Robin Implementations of Processor Sharing, Including Overhead
Analysis of Round-Robin Implementations of Processor Sharing, Including Overhead Steve Thompson and Lester Lipsky Computer Science & Engineering University of Connecticut Storrs, CT 669 Email: sat3@engr.uconn.edu;
More informationFair Operation of Multi-Server and Multi-Queue Systems
Fair Operation of Multi-Server and Multi-Queue Systems David Raz School of Computer Science Tel-Aviv University, Tel-Aviv, Israel davidraz@post.tau.ac.il Benjamin Avi-Itzhak RUTCOR, Rutgers University,
More informationScheduling Algorithms for Multiprogramming in a Hard Realtime Environment
Scheduling Algorithms for Multiprogramming in a Hard Realtime Environment C. Liu and J. Layland Journal of the ACM, 20(1):46--61, January 1973. 2 Contents 1. Introduction and Background 2. The Environment
More informationReal-Time Scheduling. Real Time Operating Systems and Middleware. Luca Abeni
Real Time Operating Systems and Middleware Luca Abeni luca.abeni@unitn.it Definitions Algorithm logical procedure used to solve a problem Program formal description of an algorithm, using a programming
More informationReal-Time Scheduling and Resource Management
ARTIST2 Summer School 2008 in Europe Autrans (near Grenoble), France September 8-12, 2008 Real-Time Scheduling and Resource Management Lecturer: Giorgio Buttazzo Full Professor Scuola Superiore Sant Anna
More informationIntroduction to Queueing Theory
Introduction to Queueing Theory Raj Jain Washington University in Saint Louis Jain@eecs.berkeley.edu or Jain@wustl.edu A Mini-Course offered at UC Berkeley, Sept-Oct 2012 These slides and audio/video recordings
More informationReal-Time Scheduling
1 Real-Time Scheduling Formal Model [Some parts of this lecture are based on a real-time systems course of Colin Perkins http://csperkins.org/teaching/rtes/index.html] Real-Time Scheduling Formal Model
More informationSPT is Optimally Competitive for Uniprocessor Flow
SPT is Optimally Competitive for Uniprocessor Flow David P. Bunde Abstract We show that the Shortest Processing Time (SPT) algorithm is ( + 1)/2-competitive for nonpreemptive uniprocessor total flow time
More informationProportional Share Resource Allocation Outline. Proportional Share Resource Allocation Concept
Proportional Share Resource Allocation Outline Fluid-flow resource allocation models» Packet scheduling in a network Proportional share resource allocation models» CPU scheduling in an operating system
More informationReal-time Scheduling of Periodic Tasks (2) Advanced Operating Systems Lecture 3
Real-time Scheduling of Periodic Tasks (2) Advanced Operating Systems Lecture 3 Lecture Outline The rate monotonic algorithm (cont d) Maximum utilisation test The deadline monotonic algorithm The earliest
More informationQueueing Theory and Simulation. Introduction
Queueing Theory and Simulation Based on the slides of Dr. Dharma P. Agrawal, University of Cincinnati and Dr. Hiroyuki Ohsaki Graduate School of Information Science & Technology, Osaka University, Japan
More informationAdvanced Computer Networks Lecture 3. Models of Queuing
Advanced Computer Networks Lecture 3. Models of Queuing Husheng Li Min Kao Department of Electrical Engineering and Computer Science University of Tennessee, Knoxville Spring, 2016 1/13 Terminology of
More information