Scheduling Introduction to Scheduling

Slides:

Advertisements

Similar presentations

Chapter 5: CPU Scheduling

Advertisements

Uniprocessor Scheduling Chapter 9 Operating Systems: Internals and Design Principles, 6/E William Stallings Patricia Roy Manatee Community College, Venice,

CPU Scheduling.

1 Processes and Threads Chapter Processes 2.2 Threads 2.3 Interprocess communication 2.4 Classical IPC problems 2.5 Scheduling.

© 2004, D. J. Foreman 1 Scheduling & Dispatching.

Scheduling Criteria CPU utilization – keep the CPU as busy as possible (from 0% to 100%) Throughput – # of processes that complete their execution per.

CPU Scheduling Tanenbaum Ch 2.4 Silberchatz and Galvin Ch 5.

Topic : Process Management Lecture By: Rupinder Kaur Lecturer IT, SRS Govt. Polytechnic College for Girls,Ludhiana.

OS, , Part II CPU Scheduling Department of Computer Engineering, PSUWannarat Suntiamorntut.

Chapter 5 CPU Scheduling. CPU Scheduling Topics: Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling.

CPU Scheduling Section 2.5.

CS 311 – Lecture 23 Outline Kernel – Process subsystem Process scheduling Scheduling algorithms User mode and kernel mode Lecture 231CS Operating.

Scheduling in Batch Systems

CS 3013 & CS 502 Summer 2006 Scheduling1 The art and science of allocating the CPU and other resources to processes.

OS Spring ’ 04 Scheduling Operating Systems Spring 2004.

1 Pertemuan 8 Penjadwalan (lanjutan) Matakuliah: T0316/sistem Operasi Tahun: 2005 Versi/Revisi: 5.

Chapter 2 Processes and Threads Scheduling Classical Problems.

CS 104 Introduction to Computer Science and Graphics Problems Operating Systems (2) Process Management 10/03/2008 Yang Song (Prepared by Yang Song and.

5: CPU-Scheduling1 Jerry Breecher OPERATING SYSTEMS SCHEDULING.

Wk 2 – Scheduling 1 CS502 Spring 2006 Scheduling The art and science of allocating the CPU and other resources to processes.

Job scheduling Queue discipline.

1 Processes and Threads Chapter Processes 2.2 Threads 2.3 Interprocess communication 2.4 Classical IPC problems 2.5 Scheduling.

Computer Architecture and Operating Systems CS 3230: Operating System Section Lecture OS-3 CPU Scheduling Department of Computer Science and Software Engineering.

Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Technology Education Lecture 5 Operating Systems.

Processes and Threads.

1 Process States (1) Possible process states –running –blocked –ready Transitions between states shown.

OPERATING SYSTEMS CPU SCHEDULING.  Introduction to CPU scheduling Introduction to CPU scheduling  Dispatcher Dispatcher  Terms used in CPU scheduling.

Scheduling Chap 2. Scheduling Introduction to Scheduling (1) Bursts of CPU usage alternate with periods of I/O wait –a CPU-bound process –an I/O bound.

Scheduling. Alternating Sequence of CPU And I/O Bursts.

1 Scheduling The part of the OS that makes the choice of which process to run next is called the scheduler and the algorithm it uses is called the scheduling.

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

CPU Scheduling Basic Concepts Scheduling Criteria Scheduling Algorithms Thread Scheduling Multiple-Processor Scheduling Operating Systems Examples Algorithm.

2.5 Scheduling Given a multiprogramming system. Given a multiprogramming system. Many times when more than 1 process is waiting for the CPU (in the ready.

Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Lecture 7: CPU Scheduling Chapter 5.

Operating Systems Scheduling. Bursts of CPU usage alternate with periods of waiting for I/O. (a) A CPU-bound process. (b) An I/O-bound process. Scheduling.

Cpr E 308 Spring 2005 Process Scheduling Basic Question: Which process goes next? Personal Computers –Few processes, interactive, low response time Batch.

ITFN 2601 Introduction to Operating Systems Lecture 4 Scheduling.

2.5 Scheduling. Given a multiprogramming system, there are many times when more than 1 process is waiting for the CPU (in the ready queue). Given a multiprogramming.

CSC 322 Operating Systems Concepts Lecture - 10: by Ahmed Mumtaz Mustehsan Special Thanks To: Tanenbaum, Modern Operating Systems 3 e, (c) 2008 Prentice-Hall,

Processor Scheduling Hank Levy. 22/4/2016 Goals for Multiprogramming In a multiprogramming system, we try to increase utilization and thruput by overlapping.

Lecture Topics: 11/15 CPU scheduling: –Scheduling goals and algorithms.

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

Operating Systems Scheduling. Scheduling Short term scheduler (CPU Scheduler) –Whenever the CPU becomes idle, a process must be selected for execution.

1 Uniprocessor Scheduling Chapter 3. 2 Alternating Sequence of CPU And I/O Bursts.

Chapter 4 CPU Scheduling. 2 Basic Concepts Scheduling Criteria Scheduling Algorithms Multiple-Processor Scheduling Real-Time Scheduling Algorithm Evaluation.

Lecture 4 CPU scheduling. Basic Concepts Single Process  one process at a time Maximum CPU utilization obtained with multiprogramming CPU idle :waiting.

Process Scheduling. Scheduling Strategies Scheduling strategies can broadly fall into two categories  Co-operative scheduling is where the currently.

CPU scheduling.  Single Process  one process at a time  Maximum CPU utilization obtained with multiprogramming  CPU idle :waiting time is wasted 2.

Lecture 5 Scheduling. Today CPSC Tyson Kendon Updates Assignment 1 Assignment 2 Concept Review Scheduling Processes Concepts Algorithms.

CPU Scheduling Andy Wang Operating Systems COP 4610 / CGS 5765.

Uniprocessor Scheduling Chapter 9 Operating Systems: Internals and Design Principles, 6/E William Stallings Patricia Roy Manatee Community College, Venice,

CPU SCHEDULING.

Chapter 5a: CPU Scheduling

Networks and Operating Systems: Exercise Session 2

April 6, 2001 Gary Kimura Lecture #6 April 6, 2001

Chapter 2 Scheduling.

Chapter 5: CPU Scheduling

CPU Scheduling.

Chapter 6: CPU Scheduling

זימון תהליכים מדיניות בסיסיות: RR, FCFS, SJF

Lecture 23: Process Scheduling for Interactive Systems

MODERN OPERATING SYSTEMS Third Edition ANDREW S

TDC 311 Process Scheduling.

Processes and Threads Part III

Outline Scheduling algorithms Multi-processor scheduling

Chapter 5: CPU Scheduling

Processor Scheduling Hank Levy 1.

Shortest-Job-First (SJR) Scheduling

Scheduling 21 May 2019.

CPU Scheduling CSE 2431: Introduction to Operating Systems

Presentation transcript:

Scheduling Introduction to Scheduling Bursts of CPU usage alternate with periods of I/O wait a CPU-bound process an I/O bound process

When to Schedule 1. At process creation 2. At process termination 3. At blocking system calls 4. At I/O interrupt Preemtive and non-preemtive scheduling algorithms

Goals of Scheduling

Scheduling in Batch Systems (1) (a) First-come-first-served (FCFS) (b) Shortest-job-first (SJF) - provably optimal if all jobs are known in advance (c) Shortest-remaining-time-next (SRTN)

Scheduling in Batch Systems (2) Three level scheduling

Scheduling in Interactive Systems (1) Round Robin Scheduling (a) list of runnable processes (b) list of runnable processes after B uses up its quantum Length of quantum: too short => waste of CPU time too long => poor response

Scheduling in Interactive Systems (2) A scheduling algorithm with four priority classes Static and dynamic priority allocations, e.g. 1/f.

Scheduling in Interactive Systems (3) Multiple queues Shortest process next; aging (weighted average) Guaranteed scheduling (1/n) Lottery scheduling - biased randomness, passing tickets Fair share scheduling

Scheduling in Real-Time Systems Schedulable real-time system Given m periodic events event i occurs within period Pi and requires Ci seconds Then the load can only be handled if

Policy versus Mechanism Separate what is allowed to be done with how it is done a process knows which of its children threads are important and need priority Scheduling algorithm parameterized mechanism in the kernel Parameters filled in by user processes policy set by user process

Thread Scheduling (1) Possible scheduling of user-level threads 50-msec process quantum, threads run 5 msec/CPU burst Application-specific thread schedulers

Thread Scheduling (2) Possible scheduling of kernel-level threads 50-msec process quantum threads run 5 msec/CPU burst

The UNIX scheduler is based on a multilevel queue structure

Scheduling in Windows (1) Mapping of Win32 priorities to Windows 2000 priorities

Scheduling in Windows (2) Windows 2000 supports 32 priorities for threads