Save this PDF as:

Size: px
Start display at page:

## Transcription

3 5.7 Consider the following set of processes, with the length of the CPU burst time given in milliseconds: Process Burst Time Priority P P P P P The processes are assumed to have arrived in the order P 1, P 2, P 3, P 4, P 5 all at time 0. a. Draw four Gantt charts that illustrate the execution of these processes using the following scheduling algorithms: FCFS, SJF, nonpreemptive priority (a smaller priority number implies a higher priority), and RR (quantum = 1). b. What is the turnaround time of each process for each of the scheduling algorithms in part a? c. What is the waiting time of each process for each of these scheduling algorithms? d. Which of the algorithms results in the minimum average waiting time (over all processes)? a. The four Gantt charts are b. Turnaround time FCFS RR SJF Priority P P P P P c. Waiting time (turnaround time minus burst time) FCFS RR SJF Priority P P P P P d. Shortest Job First 5.8 The following processes are being scheduled using a preemptive, round-robin scheduling algorithm. Each process is assigned a numerical priority, with a higher number indicating a higher relative priority. In addition to the processes listed below, the system also has an idle task (which consumes no CPU resources and is identified as P idle ). This task has priority 0 and is scheduled whenever the system has no other available

4 processes to run. The length of a time quantum is 10 units. If a process is preempted by a higher-priority process, the preempted process is placed at the end of the queue. Thread Priority Burst Arrival P P P P P P a. Show the scheduling order of the processes using a Gantt chart. b. What is the turnaround time for each process? c. What is the waiting time for each process? d. What is the CPU utilization rate? a. Gantt chart in handwritten notes. b. p1: , p2: = 55, p3: = 60, p4: = 15, p5: = 20, p6: = 10 c. 1 p1: 0, p2: 40, p3: 35, p4: 0, p5: 10, p6: 0 d. 105/120 = 87.5 percent. 5.9 The nice command is used to set the nice value of a process on Linux, as well as on other UNIX systems. Explain why some systems may allow any user to assign a process a nice value >= 0 yet allow only the root user to assign nice values < 0. Nice values < 0 are assigned a higher relative priority and such systems may not allow non-root processes to assign themselves higher priorities Which of the following scheduling algorithms could result in starvation? a. First-come, first-served b. Shortest job first c. Round robin d. Priority Shortest job first and priority-based scheduling algorithms could result in starvation Consider a variant of the RR scheduling algorithm where the entries in the ready queue are pointers to the PCBs. a. What would be the effect of putting two pointers to the same process in the ready queue? b. What would be two major advantages and disadvantages of this scheme? c. How would you modify the basic RR algorithm to achieve the same effect without the duplicate pointers? a. In effect, that process will have increased its priority since by getting time more often it is receiving preferential treatment. b. The advantage is that more important jobs could be given more time, in other words, higher priority in treatment. The consequence, of course, is that shorter jobs will suffer. c. Allot a longer amount of time to processes deserving higher priority. In other words, have two or more quantums possible in the Round-Robin scheme.

### Basic Concepts (1) Multiprogramming requires CPU scheduling CPU-I/O burst cycle CPU scheduler

CPU Scheduling Basic Concepts (1) Multiprogramming requires CPU scheduling CPU-I/O burst cycle CPU scheduler Short-term scheduler Ready queue may be a FIFO queue, priority queue, tree, linked list, etc.

### Chapter 6: CPU Scheduling. Basic Concepts Scheduling Criteria Scheduling Algorithms

Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Operating System Concepts 6.1 Basic Concepts Maximum CPU utilization obtained with multiprogramming. CPU I/O Burst Cycle

### CPU Scheduling. Basic Concepts. Basic Concepts (2) Basic Concepts Scheduling Criteria Scheduling Algorithms Batch systems Interactive systems

Basic Concepts Scheduling Criteria Scheduling Algorithms Batch systems Interactive systems Based on original slides by Silberschatz, Galvin and Gagne 1 Basic Concepts CPU I/O Burst Cycle Process execution

### Chapter 6: CPU Scheduling. Operating System Concepts 9 th Edition

Chapter 6: CPU Scheduling Silberschatz, Galvin and Gagne 2013 Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Thread Scheduling Multiple-Processor Scheduling Real-Time

### CPU Scheduling. CPU Scheduling

CPU Scheduling Electrical and Computer Engineering Stephen Kim (dskim@iupui.edu) ECE/IUPUI RTOS & APPS 1 CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling

### CPU Scheduling CS 571. CPU - I/O Burst Cycle. Bursts of CPU usage alternate with periods of I/O wait a CPU-bound process an I/O bound process

CPU Scheduling CS 571 1 CPU - I/O Burst Cycle Bursts of CPU usage alternate with periods of I/O wait a CPU-bound process an I/O bound process 2 1 Basic Concepts CPU I/O Burst Cycle Process execution consists

### 2. is the number of processes that are completed per time unit. A) CPU utilization B) Response time C) Turnaround time D) Throughput

Import Settings: Base Settings: Brownstone Default Highest Answer Letter: D Multiple Keywords in Same Paragraph: No Chapter: Chapter 5 Multiple Choice 1. Which of the following is true of cooperative scheduling?

### CPU Scheduling Yi Shi Fall 2015 Xi an Jiaotong University

CPU Scheduling Yi Shi Fall 2015 Xi an Jiaotong University Goals for Today CPU Schedulers Scheduling Algorithms Algorithm Evaluation Metrics Algorithm details Thread Scheduling Multiple-Processor Scheduling

### Chapter 6: CPU Scheduling

Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation Chapter 6: 6.1 Basic Concepts Maximum CPU utilization obtained with multiprogramming.

### multiple processes are kept in memory simultaneously when one process is waiting, another process executes

Terminology. Reference: Section 4.2, 5.1 Time-sharing / multiprogramming Typical proc. alternates between CPU bursts and I/O bursts To maximize CPU utilization: multiple processes are kept in memory simultaneously

### Chapter 6: CPU Scheduling

1 Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation 6.1 2 Basic Concepts Maximum CPU utilization

### Lecture 5 CPU Scheduling

Lecture 5 CPU Scheduling (Uniprocessor System) 1 Lecture Contents 1. Basic Concepts 2. Scheduling Criteria 3. Scheduling Algorithms 2 Switching CPU among processes in multiprogrammed OSs makes a computer

### CS 571 Operating Systems. CPU Scheduling. Angelos Stavrou, George Mason University

CS 571 Operating Systems CPU Scheduling Angelos Stavrou, George Mason University CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms First-Come-First-Served Shortest-Job-First, Shortest-remaining-Time-First

### Chapter 5: CPU Scheduling. Operating System Concepts 7 th Edition, Jan 14, 2005

Chapter 5: CPU Scheduling Operating System Concepts 7 th Edition, Jan 14, 2005 Silberschatz, Galvin and Gagne 2005 Outline Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling

### CSC 539: Operating Systems Structure and Design. Spring 2006

CSC 539: Operating Systems Structure and Design Spring 2006 CPU scheduling historical perspective CPU-I/O bursts preemptive vs. nonpreemptive scheduling scheduling criteria scheduling algorithms: FCFS,

### Chapter 6: CPU Scheduling. Basic Concepts

1 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

### CPU scheduling. CPU Scheduling. No.4. CPU burst vs. I/O burst. Prof. Hui Jiang Dept of Electrical Engineering and Computer Science, York University

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

### CPU scheduling. Alternating Sequence of CPU And I/O Bursts. Histogram of CPU-burst Times. CPU Scheduler

CPU scheduling Alternating Sequence of CPU And I/O Bursts Maximum CPU utilization is obtained by multiprogramming. CPU I/O Burst Cycle Process execution consists of a cycle of CPU execution and I/O wait.

### CPU Scheduling: Basic Concepts

CPU Scheduling: Basic Concepts Idea: Maximum CPU utilization obtained with multiprogramming" CPU I/O Burst Cycle Process execution consists of a cycle of CPU execution and I/O wait" Dispatcher grants CPU

### Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation

Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation 1 Basic Concepts Maximum CPU utilization obtained

### Announcements Project #2. Basic Concepts

Announcements Project #2 Is due at 6:00 PM on Friday Program #3 Posted tomorrow (implements scheduler) Reading Chapter 6 Basic Concepts CPU I/O burst cycle Process execution consists of a cycle of CPU

### CS 4410 Operating Systems. CPU Scheduling. Summer 2011 Cornell University

CS 4410 Operating Systems CPU Scheduling Summer 2011 Cornell University Today How does CPU manage the execution of simultaneously ready processes? Example Multitasking - Scheduling Scheduling Metrics Scheduling

### Chapter 5 Process Scheduling

Chapter 5 Process Scheduling CPU Scheduling Objective: Basic Scheduling Concepts CPU Scheduling Algorithms Why Multiprogramming? Maximize CPU/Resources Utilization (Based on Some Criteria) CPU Scheduling

### Student: Yu Cheng (Jade) ICS 412 Homework #4 October Process Burst Time Priority P P P P P 5 5 2

Student: Yu Cheng (Jade) ICS 412 Homework #4 October 19. 2009 Homework #4 Exercise 5.12: Consider the following set of processes, with the length of the CPU burst given in milliseconds: Process Burst Time

### Comp 204: Computer Systems and Their Implementation. Lecture 12: Scheduling Algorithms cont d

Comp 204: Computer Systems and Their Implementation Lecture 12: Scheduling Algorithms cont d 1 Today Scheduling continued Multilevel queues Examples Thread scheduling 2 Question A starvation-free job-scheduling

### Processor Scheduling. Background. Scheduling. Scheduling

Background Processor Scheduling The previous lecture introduced the basics of concurrency Processes and threads Definition, representation, management We now understand how a programmer can spawn concurrent

### Objectives. Chapter 5: CPU Scheduling. CPU Scheduler. Non-preemptive and preemptive. Dispatcher. Alternating Sequence of CPU And I/O Bursts

Objectives Chapter 5: CPU Scheduling Introduce CPU scheduling, which is the basis for multiprogrammed operating systems Describe various CPU-scheduling algorithms Discuss evaluation criteria for selecting

### Outline. V Computer Systems Organization II (Honors) (Introductory Operating Systems) CPU Scheduling: Overview. Scheduling: Components

Outline V22.0202-001 Computer Systems Organization II (Honors) (Introductory Operating Systems) Lecture 10 CPU Scheduling February 23, 2005 Announcements Lab 3 due on March 2 nd, Demos on March 2 nd and

### Objectives. Chapter 5: CPU Scheduling. CPU Scheduler. Alternating Sequence of CPU And I/O Bursts

Objectives Chapter 5: CPU Scheduling Introduce CPU scheduling, which is the basis for multiprogrammed operating systems Describe various CPU-scheduling algorithms Discuss evaluation criteria for selecting

### Instituto de Ciências Matemáticas e de Computação Departamento de Sistemas de Computação

Instituto de Ciências Matemáticas e de Computação Departamento de Sistemas de Computação SSC-0541 Sistemas Operacionais I 2º Semestre 2014 1ª Lista de Exercícios Extraída da 9ª edição em Inglês do Livro

### CPU Scheduling! Basic Concepts! Scheduling Criteria! Scheduling Algorithms!

CPU Scheduling! Basic Concepts! Scheduling Criteria! Scheduling Algorithms! First-Come-First-Served! Shortest-Job-First, Shortest-remaining-Time-First! Priority Scheduling! Round Robin! Multi-level Queue!

### Introduction to process scheduling. Process scheduling and schedulers Process scheduling criteria Process scheduling algorithms

Lecture Overview Introduction to process scheduling Process scheduling and schedulers Process scheduling criteria Process scheduling algorithms First-come, first-serve Shortest-job-first Priority Round-robin

### Chapter 6 CPU Scheduling. Contents

Contents 1. Introduction 2. Computer-System Structures 3. Operating-System Structures 4. Processes 5. Threads 6. CPU Scheduling 7. Process Synchronization 8. Deadlocks 9. Memory Management 10. Virtual

### CPU Scheduling. Prof. Sirer (dr. Willem de Bruijn) CS 4410 Cornell University

CPU Scheduling Prof. Sirer (dr. Willem de Bruijn) CS 4410 Cornell University Problem You are the cook at the state st. diner customers continually enter and place their orders Dishes take varying amounts

### Chapter 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

### Types of jobs. CPU-bound vs. I/O-bound. Batch, Interactive, real time. Maximum CPU utilization obtained with multiprogramming

CPU Scheduling Types of jobs CPU-bound vs. I/O-bound Maximum CPU utilization obtained with multiprogramming Batch, Interactive, real time Different goals, affects scheduling policies CPU Scheduler Selects

### CPU Scheduling. Chapter 5

CPU Scheduling Chapter 5 Basic Concepts Maximum CPU utilization obtained with multiprogramming CPU I/O Burst Cycle Process execution consists of a cycle of CPU execution and I/O wait CPU burst distribution

### CS420: Operating Systems

CPU Scheduling James Moscola Department of Engineering & Computer Science York College of Pennsylvania Based on Operating System Concepts, 9th Edition by Silberschatz, Galvin, Gagne Scheduling Concepts

### Process Scheduling. Minsoo Ryu. Real-Time Computing and Communications Lab. Hanyang University.

Process Scheduling Minsoo Ryu Real-Time Computing and Communications Lab. Hanyang University msryu@hanyang.ac.kr Basic Concepts Scheduling Criteria Scheduling Algorithms Windows NT Scheduler Topics Covered

### Chapter 6: CPU Scheduling

Chapter 6: CPU Scheduling Edited by Ghada Ahmed, PhD ghada@fcih.net Silberschatz, Galvin and Gagne 2013 Basic Concepts Maximum CPU utilization obtained with multiprogramming CPU I/O Burst Cycle Process

### Chapter 5: Process Scheduling. Chapter 5: Process Scheduling

Chapter 5: Process Scheduling Chapter 5: Process Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Operating Systems Examples Java Thread Scheduling Algorithm

### Q. 1 Q. 1 Q. 1 Q. 1. Discuss how the following pairs of scheduling criteria conflict in certain settings.

CPU and response time I/O device and CPU CPU and response time CPU and response time CPU and response time minimize context switching CPU minimize context switching CPU conflict tasks would need to wait

### COSC243 Part 2: Operating Systems

COSC243 Part 2: Operating Systems Lecture 17: CPU Scheduling Zhiyi Huang Dept. of Computer Science, University of Otago Zhiyi Huang (Otago) COSC243 Lecture 17 1 / 30 Overview Last lecture: Cooperating

### CS307 Operating Systems CPU Scheduling

CS307 CPU Scheduling Fan Wu Department of Computer Science and Engineering Shanghai Jiao Tong University Spring 2016 Basic Concepts Maximize CPU utilization obtained with multiprogramming CPU I/O Burst

### Chapter 5: CPU Scheduling!

Chapter 5: CPU Scheduling Operating System Concepts 8 th Edition, Silberschatz, Galvin and Gagne 2009 Chapter 5: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Thread Scheduling

### Operating Systems Fall 2012 Lecture 4: CPU Scheduling

482000000000357 Operating Systems Fall 2012 Lecture 4: CPU Scheduling Assist. Prof. Ediz ŞAYKOL ediz.saykol@beykent.edu.tr Operating System - Main Goals Interleave the execution of the number of processes

### CPU Scheduling Outline

CPU Scheduling Outline What is scheduling in the OS? What are common scheduling criteria? How to evaluate scheduling algorithms? What are common scheduling algorithms? How is thread scheduling different

### Objectives. Concepts (2) Scheduler and interrupts. Concepts (1) Bursts

Objectives Operating Systems Part of E1.9 - Principles of Computers and Software Engineering Lecture 4: Process scheduling To introduce process scheduling algorithms Non-priority based Priority based Examine

### Chapter 6: CPU Scheduling

Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation Oct-03 1 Basic Concepts Maximum CPU utilization

### Basic Concepts. Chapter 6: CPU Scheduling. Histogram of CPU-burst Times. Dispatcher. CPU Scheduler. Alternating Sequence of CPU And I/O Bursts

Chapter 6: CPU Scheduling Basic Concepts Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation Maximum CPU utilization obtained

### Introduction to Scheduling 1

CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms FCFS, SJF, RR Exponential Averaging Multi-level Queue Scheduling Performance Evaluation Scheduling Terminology Scheduling Terminology

### CS720 - Operating Systems. CPU Scheduling

CS720 - Operating Systems CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Procesor Scheduling Real-Time Scheduling Algorithm Evaluation Slides derived from material in

### CPU Scheduling. Basic Concepts. Histogram of CPU-burst Times. Dispatcher. CPU Scheduler. Alternating Sequence of CPU and I/O Bursts

CS307 Basic Concepts Maximize CPU utilization obtained with multiprogramming CPU Scheduling CPU I/O Burst Cycle Process execution consists of a cycle of CPU execution and I/O wait CPU burst distribution

### CPU Scheduling. Basic Concepts. Basic Concepts. CPU Scheduler. Histogram of CPU-burst Times CPU. Alternating Sequence of CPU and I/O Bursts

Basic Concepts P CPU Scheduling CSCI 315 Operating Systems Design Department of Computer Science Notice: The slides for this lecture have been largely based on those accompanying the textbook Operating

### Chapter 5: Process Scheduling. Operating System Concepts 8 th Edition,

Chapter 5: Process Scheduling, Silberschatz, Galvin and Gagne 2009 Chapter 5: Process Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Thread Scheduling Multiple-Processor Scheduling

### Module 5: CPU Scheduling

Module 5: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation Operating System Concepts 5.1 Silberschatz and

### Chapter 6: CPU Scheduling. Operating System Concepts Essentials 2 nd Edition

Chapter 6: CPU Scheduling Silberschatz, Galvin and Gagne 2013 Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Thread Scheduling Multiple-Processor Scheduling Real-Time

### Announcements. Basic Concepts. Histogram of Typical CPU- Burst Times. Dispatcher. CPU Scheduler. Burst Cycle. Reading

Announcements Reading Chapter 5 Chapter 7 (Monday or Wednesday) Basic Concepts CPU I/O burst cycle Process execution consists of a cycle of CPU execution and I/O wait. CPU burst distribution What are the

### Process and Thread Scheduling. Raju Pandey Department of Computer Sciences University of California, Davis Winter 2005

Process and Thread Scheduling Raju Pandey Department of Computer Sciences University of California, Davis Winter 2005 Scheduling Context switching an interrupt occurs (device completion, timer interrupt)

### spends most its time performing I/O How is thread scheduling different from process scheduling? What are the issues in multiple-processor scheduling?

CPU Scheduling Outline What is scheduling in the OS? What are common scheduling criteria? How to evaluate scheduling algorithms? What are common scheduling algorithms? How is thread scheduling different

### Process boundness. Process scheduling. Alternating Sequence of CPU and I/O Bursts. Histogram of CPU-burst Times

Process scheduling slide 1 Process boundness slide 2 See Silberschatz Chapter 5 Processes can be described as either: I/O-bound process - spends more time doing I/O than computations, many short bursts

### Chapter 5: Process Scheduling

Chapter 5: Process Scheduling Chapter 5: Process Scheduling 5.1 Basic Concepts 5.2 Scheduling Criteria 5.3 Scheduling Algorithms 5.3.1 First-Come, First-Served Scheduling 5.3.2 Shortest-Job-First Scheduling

### Chapter 5: CPU Scheduling!

Chapter 5: CPU Scheduling! Basic Concepts! Scheduling Criteria! Scheduling Algorithms! Multiple-Processor Scheduling! Real-Time Scheduling! Algorithm Evaluation! 6.1! Basic Concepts! Long-term scheduler

### Silberschatz and Galvin

Silberschatz and Galvin Chapter 5 CPU Scheduling CPSC 410--Richard Furuta 01/19/99 1 Topics covered Basic concepts/scheduling criteria Non-preemptive and Preemptive scheduling Scheduling algorithms Algorithm

### CPU Scheduling. CS439: Principles of Computer Systems September 7, 2016

CPU Scheduling CS439: Principles of Computer Systems September 7, 2016 Last Time A process is a unit of execution Defines an address space An abstraction for protection Processes are represented as Process

### CS416 CPU Scheduling

CS416 CPU Scheduling CS 416: Operating Systems Design, Spring 2011 Department of Computer Science Rutgers University Rutgers Sakai: 01:198:416 Sp11 (https://sakai.rutgers.edu) Assumptions Pool of jobs

### Objectives. Chapter 5: Process Scheduling. Chapter 5: Process Scheduling. 5.1 Basic Concepts. To introduce CPU scheduling

Objectives To introduce CPU scheduling To describe various CPU-scheduling algorithms Chapter 5: Process Scheduling To discuss evaluation criteria for selecting the CPUscheduling algorithm for a particular

### Chapter 6 Process Scheduling

1 Chapter 6 Process Scheduling CPU scheduling deals with the problem of deciding which of the processes in the ready queue is to be allocated the CPU. There are many different CPU-scheduling algorithms.

### Chapter 5: CPU Scheduling

Chapter 5: CPU Scheduling Chapter 5: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Thread Scheduling Operating Systems Examples

### Scheduling. Yücel Saygın. These slides are based on your text book and on the slides prepared by Andrew S. Tanenbaum

Scheduling Yücel Saygın These slides are based on your text book and on the slides prepared by Andrew S. Tanenbaum 1 Scheduling Introduction to Scheduling (1) Bursts of CPU usage alternate with periods

### Computer Systems II. CPU Scheduling. Review of Process States

Computer Systems II CPU Scheduling 1 Review of Process States 2 1 OS Queuing Model Enter Ready queue CPU Exit Disk Queue Network Queue Printer Queue Processes enter and leave the system 3 CPU Scheduling

### CPU Scheduling. Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling

CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Basic Concepts An OS must allocate resources amongst competing processes The resource

### Chapter 6: CPU Scheduling

Chapter 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Thread Scheduling Multiple-Processor Scheduling 1.1 Maximum CPU utilization obtained with multiprogramming CPU I/O Burst

### Chapter 5: CPU Scheduling

Chapter 5: CPU Scheduling Chapter 5: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Thread Scheduling Operating Systems Examples

### Scheduling for uniprocessor systems Introduction

Politecnico di Milano Introduction Lecturer: William Fornaciari Politecnico di Milano william.fornaciari@elet.polimi.it Home.dei.polimi.it/fornacia SUMMARY Basic Concepts Scheduling Criteria Scheduling

### CPU Scheduling. Multiprogrammed OS

CPU Scheduling Multiprogrammed OS Efficient Use of Processor By switching between jobs Thread scheduling and process scheduling often used interchangeably Which is done depends on implementation of O/S.

### Process Management. Processes. CS 502 Spring 99 WPI MetroWest/Southboro Campus

Process Management CS 502 Spring 99 WPI MetroWest/Southboro Campus Processes Process Concept Process Scheduling Operations on Processes Cooperating Processes Threads Interprocess Communication 1 1 Process

### Scheduling Criteria. response time/turnaround time: time required to finish a task

Processor Scheduling 1 Scheduling Criteria CPU utilization: keep the CPU as busy as possible throughput: rate at which tasks are completed response time/turnaround time: time required to finish a task

### CPU Scheduling. Date. 2/2/2004 Operating Systems 1

CPU Scheduling Date 2/2/2004 Operating Systems 1 Basic concepts Maximize CPU utilization with multi programming. CPU I/O Burst Cycle Process execution consists of a cycle of CPU execution and I/O wait.

### Chapter 5: CPU Scheduling. Operating System Concepts 8 th Edition,

Chapter 5: CPU Scheduling, Silberschatz, Galvin and Gagne 2009 Chapter 5: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Thread Scheduling Multiple-Processor Scheduling Linux Example

### PROCESS SCHEDULING. CS124 Operating Systems Winter 2013-2014, Lecture 12

PROCESS SCHEDULING CS124 Operating Systems Winter 2013-2014, Lecture 12 2 Process Scheduling OSes must manage the allocation and sharing of hardware resources to applications that use them Most important

### W4118 Operating Systems. Instructor: Junfeng Yang

W4118 Operating Systems Instructor: Junfeng Yang Outline Introduction to scheduling Scheduling algorithms 1 Direction within course Until now: interrupts, processes, threads, synchronization Mostly mechanisms

### Deciding which process to run. (Deciding which thread to run) Deciding how long the chosen process can run

SFWR ENG 3BB4 Software Design 3 Concurrent System Design 2 SFWR ENG 3BB4 Software Design 3 Concurrent System Design 11.8 10 CPU Scheduling Chapter 11 CPU Scheduling Policies Deciding which process to run

### Operating Systems. Scheduling. Lecture 8 Michael O Boyle

Operating Systems Scheduling Lecture 8 Michael O Boyle 1 Scheduling We have talked about context switching an interrupt occurs (device completion, timer interrupt) a thread causes a trap or exception may

### I.-C. Lin, Assistant Professor. Textbook: Operating System Concepts 8ed

I.-C. Lin, Assistant Professor. Textbook: Operating System Concepts 8ed CHAPTER 5: PROCESS SCHEDULING Chapter 5: Process Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor

### CPU SCHEDULING. Scheduling Objectives. Outline. Basic Concepts. Enforcement of fairness in allocating resources to processes

Scheduling Objectives CPU SCHEDULING Enforcement of fairness in allocating resources to processes Enforcement of priorities Make best use of available system resources Give preference to processes holding

### Module 6: CPU Scheduling. Basic Concepts

Module 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation Applied Operating System Concepts 6.1 Silberschatz,

### Agenda. CPU Scheduling. Basic Concepts. CPU Scheduler. Histogram of CPU-burst Times. Alternating Sequence of CPU And I/O Bursts

TDDB3: Concurrent programming and operating systems [SGG7] Chapter 5 Agenda CPU Scheduling Introduce CPU scheduling Describe various CPU scheduling algorithms Discuss evaluation criteria of CPU scheduling

### Module 6: CPU Scheduling. Basic Concepts. Alternating Sequence of CPU And I/O Bursts

Module 6: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation Applied Operating System Concepts 6.1 Basic Concepts

### Scheduling Criteria. A task might be a single CPU burst, a thread, or an applicationlevel service request. The Nature of Program Executions

Processor Scheduling 1 Scheduling Criteria CPU utilization: keep the CPU as busy as possible throughput: rate at which tasks are completed response time/turnaround time: time required to finish a task

### Chapter 5: Process Scheduling. Operating System Concepts with Java 8 th Edition

Chapter 5: Process Scheduling Operating System Concepts with Java 8 th Edition 5.1 Silberschatz, Galvin and Gagne 2009 Chapter 5: CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms

### Classification of Scheduling Activity Queuing Diagram for Scheduling

CPU Scheduling CPU Scheduling Chapter 6 We concentrate on the problem of scheduling the usage of a single processor among all the existing processes in the system The goal is to achieve High processor

### ECE3055 Computer Architecture and Operating Systems

ECE3055 Computer Architecture and Operating Systems Lecture: CPU Scheduling Prof. Hsien-Hsin Hsin Sean Lee School of Electrical and Computer Engineering Georgia Institute of Technology H.-H. S. Lee 1 Overview

### Lecture 5 Process Scheduling (chapter 5)

Bilkent University Department of Computer Engineering CS342 Operating Systems Lecture 5 Process Scheduling (chapter 5) Dr. İbrahim Körpeoğlu http://www.cs.bilkent.edu.tr/~korpe 1 References The slides

### CPU Scheduling. Dr. Yingwu Zhu

CPU Scheduling Dr. Yingwu Zhu Overview In discussing process/threads management and synchronization, we talked about context switching among processes/threads on the ready queue But we have not glossed

### Scheduling I. Introduction to scheduling. Scheduling algorithms

Scheduling I Introduction to scheduling Scheduling algorithms 1 Role of Dispatcher vs. Scheduler Dispatcher Low-level mechanism Responsibility: context switch Scheduler High-level policy Responsibility: