Fall 2000M.B. Ibáñez Lecture 14 Memory Management II Contiguous Allocation.

Slides:



Advertisements
Similar presentations
Part IV: Memory Management
Advertisements

Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Lecture 13: Main Memory (Chapter 8)
Memory Management Chapter 7.
Fixed/Variable Partitioning
Memory Management Chapter 7. Memory Management Subdividing memory to accommodate multiple processes Memory needs to be allocated efficiently to pack as.
Memory Management Subdividing memory to accommodate multiple processes Memory needs to be allocated to ensure a reasonable supply of ready processes to.
Allocating Memory.
Chapter 7 Memory Management
Chapter 7 Memory Management Operating Systems: Internals and Design Principles, 6/E William Stallings Dave Bremer Otago Polytechnic, N.Z. ©2009, Prentice.
Memory Management. Managing Memory … The Simplest Case The O/S User Program 0 0xFFF … * Early PCs and Mainframes * Embedded Systems One user program at.
OS Fall’02 Memory Management Operating Systems Fall 2002.
1 CSE 380 Computer Operating Systems Instructor: Insup Lee University of Pennsylvania, Fall 2002 Lecture Note: Memory Management.
Chapter 7 Memory Management
Chapter 9 – Real Memory Organization and Management
Memory Management Chapter 4. Memory hierarchy Programmers want a lot of fast, non- volatile memory But, here is what we have:
Memory Management Chapter 7. Memory Management Subdividing memory to accommodate multiple processes Memory needs to be allocated efficiently to pack as.
CSCI2413 Lecture 5 Operating Systems Memory Management 1 phones off (please)
Module 3.0: Memory Management
Understanding Operating Systems1 Operating Systems Virtual Memory Thrashing Single-User Contiguous Scheme Fixed Partitions Dynamic Partitions.
Memory Management Chapter 7 B.Ramamurthy. Memory Management Subdividing memory to accommodate multiple processes Memory needs to allocated efficiently.
1 Memory Management Chapter 7. 2 Memory Management Subdividing memory to accommodate multiple processes Memory needs to be allocated to ensure a reasonable.
1 Friday, June 30, 2006 "Man's mind, once stretched by a new idea, never regains its original dimensions." - Oliver Wendell Holmes, Jr.
Memory Management Chapter 5.
Memory Management Five Requirements for Memory Management to satisfy: –Relocation Users generally don’t know where they will be placed in main memory May.
 2004 Deitel & Associates, Inc. All rights reserved. Chapter 9 – Real Memory Organization and Management Outline 9.1 Introduction 9.2Memory Organization.
03/17/2008CSCI 315 Operating Systems Design1 Virtual Memory Notice: The slides for this lecture have been largely based on those accompanying the textbook.
03/05/2008CSCI 315 Operating Systems Design1 Memory Management Notice: The slides for this lecture have been largely based on those accompanying the textbook.
Chapter 7 Memory Management
1 Lecture 8: Memory Mangement Operating System I Spring 2008.
Memory management. Instruction execution cycle Fetch instruction from main memory Decode instruction Fetch operands (if needed0 Execute instruction Store.
Chapter 91 Memory Management Chapter 9   Review of process from source to executable (linking, loading, addressing)   General discussion of memory.
Operating System Chapter 7. Memory Management Lynn Choi School of Electrical Engineering.
Tutorial 7 Memory Management presented by: Antonio Maiorano Paul Di Marco.
Example of a Resource Allocation Graph CS1252-OPERATING SYSTEM UNIT III1.
Operating System 7 MEMORY MANAGEMENT. MEMORY MANAGEMENT REQUIREMENTS.
Memory Management Chapter 7.
Memory Management. Process must be loaded into memory before being executed. Memory needs to be allocated to ensure a reasonable supply of ready processes.
1 Memory Management (a). 2 Background  Program must be brought into memory and placed within a process for it to be run.  Input queue – collection of.
Memory Management Operating Systems: Internals and Design Principles, 6/E William Stallings Dave Bremer Otago Polytechnic, N.Z. ©2008, Prentice Hall Dr.
Chapter 7 Memory Management
Chapter 7 Memory Management Seventh Edition William Stallings Operating Systems: Internals and Design Principles.
CGS 3763 Operating Systems Concepts Spring 2013 Dan C. Marinescu Office: HEC 304 Office hours: M-Wd 11: :30 AM.
Ch. 4 Memory Mangement Parkinson’s law: “Programs expand to fill the memory available to hold them.”
Memory Management Chapter 7.
Memory Management. Roadmap Basic requirements of Memory Management Memory Partitioning Basic blocks of memory management –Paging –Segmentation.
Subject: Operating System.
1 Memory Management Chapter 7. 2 Memory Management Subdividing memory to accommodate multiple processes Memory needs to be allocated to ensure a reasonable.
1 Memory Management Chapter 7. 2 Memory Management Subdividing memory to accommodate multiple processes Memory needs to be allocated to ensure a reasonable.
1 Memory Management Chapter 7. 2 Memory Management Subdividing memory to accommodate multiple processes Memory needs to be allocated to ensure a reasonable.
Basic Memory Management 1. Readings r Silbershatz et al: chapters
Contiguous Memory Allocation Contiguous Memory Allocation  One of the simplest methods for allocating memory is to divide memory into.
Informationsteknologi Wednesday, October 3, 2007Computer Systems/Operating Systems - Class 121 Today’s class Memory management Virtual memory.
Copyright ©: Nahrstedt, Angrave, Abdelzaher, Caccamo 1 Memory management & paging.
CS6502 Operating Systems - Dr. J. Garrido Memory Management – Part 1 Class Will Start Momentarily… Lecture 8b CS6502 Operating Systems Dr. Jose M. Garrido.
Memory Management Program must be brought (from disk) into memory and placed within a process for it to be run Main memory and registers are only storage.
Chapter 7 Memory Management Eighth Edition William Stallings Operating Systems: Internals and Design Principles.
1 Memory Management n In most schemes, the kernel occupies some fixed portion of main memory and the rest is shared by multiple processes.
2010INT Operating Systems, School of Information Technology, Griffith University – Gold Coast Copyright © William Stallings /2 Memory Management.
MEMORY MANAGEMENT. memory management  In a multiprogramming system, in order to share the processor, a number of processes must be kept in memory. 
COMP 3500 Introduction to Operating Systems Memory Management: Part 2 Dr. Xiao Qin Auburn University Slides.
Memory Management Chapter 7.
Memory Management Chapter 7.
Memory Management.
Memory Allocation The main memory must accommodate both:
Module IV Memory Organization.
Economics, Administration & Information system
The Operating System Memory Manager
Unit 6: Real Memory organization management
Presentation transcript:

Fall 2000M.B. Ibáñez Lecture 14 Memory Management II Contiguous Allocation

Fall 2000M.B. Ibáñez Single-Partition Allocation

Fall 2000M.B. Ibáñez Single-Partition Allocation Hardware Support I

Fall 2000M.B. Ibáñez Single-Partition Allocation Hardware Support II < + CPU Memory Limit register Relocation register Trap Addressing error

Fall 2000M.B. Ibáñez Multiple-partition Allocation Fixed Partitioning I Main memory is divided into a number of static partitions at system generation time. A process may be loaded into a partition of equal or smaller size. Simple to implement Little operating system overhead

Fall 2000M.B. Ibáñez Multiple-partition Allocation Fixed Partitioning II 8 M Operating System 8 M 12 M 8 M 6 M

Fall 2000M.B. Ibáñez Placement Algorithm with Partitions Equal size partitions Because all partitions are of equal size, it does not matter which partition is used If all partitions are occupied with processes that are not ready to run, then one of these processes must be swapped out to make room for a new process.

Fall 2000M.B. Ibáñez Difficulties of equal-size partitions A program may be too big to fit into a partition. In this case, the programmer must use the overlay technique. Internal fragmentation –Wasted space internal to a partition. Any program, no matter how small, occupies an entire partition.

Fall 2000M.B. Ibáñez Placement Algorithm with Partitions Unequal-size partitions Best-fit –can assign each process to the smallest partition within which it will fit –queue for each partition –processes are assigned in such a way as to minimize wasted memory within a partition

Fall 2000M.B. Ibáñez Placement Algorithm with Partitions Unequal-size partitions First-fit –Allocate the first hole that is big enough. Neither first-fit nor best-fit is clearly better in terms of storage utilization, but first-fit is generally faster

Fall 2000M.B. Ibáñez Difficulties with Unequal-size partitions The number of partitions specified at system generation time limits the number of active (not suspended) processes in the system Small jobs will not utilize partition space efficiently

Fall 2000M.B. Ibáñez One Process Queue per Partition New Processes Operating System

Fall 2000M.B. Ibáñez One Process Queue per Partition Operating System New Processes

Feedback: Privacy Policy Feedback
Do Not Sell My Personal Information
About project: SlidePlayer Terms of Service

© 2024 SlidePlayer.com Inc. All rights reserved.