Example of a Resource Allocation Graph CS1252-OPERATING SYSTEM UNIT III1.

Slides:



Advertisements
Similar presentations
Memory.
Advertisements

Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Lecture 13: Main Memory (Chapter 8)
Memory Management.
CS 311 – Lecture 21 Outline Memory management in UNIX
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Main Memory CS Memory Management1. Background Program must be brought (from disk) into memory and placed within a process for it to be run Main.
Modified from Silberschatz, Galvin and Gagne Lecture 16 Chapter 8: Main Memory.
Chapter 9: Main Memory. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts – 7 th Edition, Feb 22, 2005 Chapter 9: Memory Management Background.
Background A program must be brought into memory and placed within a process for it to be executed. Input queue – collection of processes on the disk that.
Memory Management.
03/10/2004CSCI 315 Operating Systems Design1 Memory Management Notice: The slides for this lecture have been largely based on those accompanying the textbook.
1 Friday, June 30, 2006 "Man's mind, once stretched by a new idea, never regains its original dimensions." - Oliver Wendell Holmes, Jr.
Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Chapter 8: Main Memory.
Chapter 7: Main Memory CS 170, Fall Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation.
Main Memory. Background Program must be brought (from disk) into memory and placed within a process for it to be run Main memory and registers are only.
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.
Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Chapter 8: Main Memory.
Chapter 8: Main Memory.
Chapter 8: Main Memory. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Chapter 8: Memory Management Background Swapping Contiguous.
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Silberschatz, Galvin and Gagne  2002 Modified for CSCI 346, Royden, Operating System Concepts Operating Systems Lecture 24 Paging.
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Chapter 8: Memory Management. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Chapter 8: Memory Management Background Swapping Contiguous.
Silberschatz, Galvin and Gagne  2002 Modified for CSCI 399, Royden, Operating System Concepts Operating Systems Lecture 32 Paging Read Ch. 9.4.
Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Technology Education Lecture 8 Operating Systems.
Computer Architecture and Operating Systems CS 3230: Operating System Section Lecture OS-7 Memory Management (1) Department of Computer Science and Software.
Swapping and Contiguous Memory Allocation. Multistep Processing of a User Program User programs go through several steps before being run. Program components.
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Operating Systems Chapter 8
Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Chapter 8: Main Memory.
8.1 Silberschatz, Galvin and Gagne ©2005 Operating System Principles Chapter 8: Memory-Management Strategies Objectives To provide a detailed description.
CGS 3763 Operating Systems Concepts Spring 2013 Dan C. Marinescu Office: HEC 304 Office hours: M-Wd 11: :30 AM.
CS212: OPERATING SYSTEM Lecture 5: Memory Management Strategies 1 Computer Science Department.
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Chapter 8: Main Memory.
Memory Management 1. Background Programs must be brought (from disk) into memory for them to be run Main memory and registers are only storage CPU can.
Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Chapter 8: Main Memory.
1 Address Translation Memory Allocation –Linked lists –Bit maps Options for managing memory –Base and Bound –Segmentation –Paging Paged page tables Inverted.
Chapter 8: Memory-Management Strategies. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Principles Chapter 8: Memory-Management Strategies.
CE Operating Systems Lecture 14 Memory management.
Memory. Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation.
Main Memory. Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Example: The.
Chapter 8: Memory-Management Strategies. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Principles Chapter 8: Memory-Management Strategies.
Chapter 8: Memory-Management Strategies. 8.2Operating System Principles Chapter 8: Memory-Management Strategies Background Swapping Contiguous Memory.
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Chapter 8: Main Memory. Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation.
Chapter 8: Main Memory. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts – 7 th Edition, Feb 22, 2005 Chapter 8: Memory Management n.
Chapter 8: Main Memory. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts – 7 th Edition, Feb 22, 2005 Memory and Addressing It all starts.
8.1 Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition Fragmentation External Fragmentation – total memory space exists to satisfy.
Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition Chapter 8: Main Memory.
Silberschatz, Galvin and Gagne  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation.
Silberschatz, Galvin and Gagne ©2009 Operating System Concepts – 8 th Edition, Chapter 8: Main Memory.
Chapter 8: Memory Management. 8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Chapter 8: Memory Management Background Swapping Contiguous.
Chapter 2: Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging Operating System Concepts.
Chapter 7: Main Memory CS 170, Fall Program Execution & Memory Management Program execution Swapping Contiguous Memory Allocation Paging Structure.
Silberschatz, Galvin and Gagne ©2013 Operating System Concepts – 9 th Edition, Chapter 8: Memory- Management Strategies.
Ghsong  Operating System Concepts Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with.
Memory Management Lectures notes from the text supplement by Siberschatz and Galvin Modified by B.Ramamurthy 11/12/2018.
Memory Management Lectures notes from the text supplement by Siberschatz and Galvin Modified by B.Ramamurthy Chapter 8 11/24/2018.
Memory Management Lectures notes from the text supplement by Siberschatz and Galvin Modified by B.Ramamurthy Chapter 9 12/1/2018.
So far… Text RO …. printf() RW link printf Linking, loading
Main Memory Background Swapping Contiguous Allocation Paging
Lecture 3: Main Memory.
Chapter 8: Memory Management strategies
Memory Management Lectures notes from the text supplement by Siberschatz and Galvin Modified by B.Ramamurthy Chapter 9 4/5/2019.
Page Main Memory.
Presentation transcript:

Example of a Resource Allocation Graph CS1252-OPERATING SYSTEM UNIT III1

Resource Allocation Graph With A Deadlock CS1252-OPERATING SYSTEM UNIT III2

Resource Allocation Graph With A Cycle But No Deadlock CS1252-OPERATING SYSTEM UNIT III3

Safe, Unsafe, Deadlock State CS1252-OPERATING SYSTEM UNIT III4

Resource-Allocation Graph For Deadlock Avoidance CS1252-OPERATING SYSTEM UNIT III5

Unsafe State In Resource-Allocation Graph CS1252-OPERATING SYSTEM UNIT III6

Resource-Allocation Graph and Wait-for Graph CS1252-OPERATING SYSTEM UNIT III7 Resource-Allocation GraphCorresponding wait-for graph

Overlays for a Two-Pass Assembler CS1252-OPERATING SYSTEM UNIT III8

Schematic View of Swapping CS1252-OPERATING SYSTEM UNIT III9

Hardware Support for Relocation and Limit Registers CS1252-OPERATING SYSTEM UNIT III10

Contiguous Allocation (Cont.) Multiple-partition allocation – Hole – block of available memory; holes of various size are scattered throughout memory. – When a process arrives, it is allocated memory from a hole large enough to accommodate it. – Operating system maintains information about: a) allocated partitions b) free partitions (hole) CS1252-OPERATING SYSTEM UNIT III11 OS process 5 process 8 process 2 OS process 5 process 2 OS process 5 process 2 OS process 5 process 9 process 2 process 9 process 10

Dynamic Storage-Allocation Problem First-fit: Allocate the first hole that is big enough. Best-fit: Allocate the smallest hole that is big enough; must search entire list, unless ordered by size. Produces the smallest leftover hole. Worst-fit: Allocate the largest hole; must also search entire list. Produces the largest leftover hole. CS1252-OPERATING SYSTEM UNIT III12 How to satisfy a request of size n from a list of free holes. First-fit and best-fit better than worst-fit in terms of speed and storage utilization.

Fragmentation External Fragmentation – total memory space exists to satisfy a request, but it is not contiguous. Internal Fragmentation – allocated memory may be slightly larger than requested memory; this size difference is memory internal to a partition, but not being used. Reduce external fragmentation by compaction – Shuffle memory contents to place all free memory together in one large block. – Compaction is possible only if relocation is dynamic, and is done at execution time. – I/O problem Latch job in memory while it is involved in I/O. Do I/O only into OS buffers. CS1252-OPERATING SYSTEM UNIT III13

Paging Logical address space of a process can be noncontiguous; process is allocated physical memory whenever the latter is available. Divide physical memory into fixed-sized blocks called frames (size is power of 2, between 512 bytes and 8192 bytes). Divide logical memory into blocks of same size called pages. Keep track of all free frames. To run a program of size n pages, need to find n free frames and load program. Set up a page table to translate logical to physical addresses. Internal fragmentation. CS1252-OPERATING SYSTEM UNIT III14

Address Translation Scheme Address generated by CPU is divided into: – Page number (p) – used as an index into a page table which contains base address of each page in physical memory. – Page offset (d) – combined with base address to define the physical memory address that is sent to the memory unit. CS1252-OPERATING SYSTEM UNIT III15

Address Translation Architecture CS1252-OPERATING SYSTEM UNIT III16

Paging Example CS1252-OPERATING SYSTEM UNIT III17

Paging Example CS1252-OPERATING SYSTEM UNIT III18

Free Frames CS1252-OPERATING SYSTEM UNIT III19 Before allocation After allocation

Paging Hardware With TLB CS1252-OPERATING SYSTEM UNIT III20

Valid (v) or Invalid (i) Bit In A Page Table CS1252-OPERATING SYSTEM UNIT III21

Two-Level Page-Table Scheme CS1252-OPERATING SYSTEM UNIT III22

Address-Translation Scheme Address-translation scheme for a two-level 32-bit paging architecture CS1252-OPERATING SYSTEM UNIT III23

Hashed Page Table CS1252-OPERATING SYSTEM UNIT III24

Inverted Page Table Architecture CS1252-OPERATING SYSTEM UNIT III25

User’s View of a Program CS1252-OPERATING SYSTEM UNIT III26

Logical View of Segmentation CS1252-OPERATING SYSTEM UNIT III user spacephysical memory space

Segmentation Hardware CS1252-OPERATING SYSTEM UNIT III28

Example of Segmentation CS1252-OPERATING SYSTEM UNIT III29

Sharing of Segments CS1252-OPERATING SYSTEM UNIT III30

MULTICS Address Translation Scheme CS1252-OPERATING SYSTEM UNIT III31

Intel Address Translation CS1252-OPERATING SYSTEM UNIT III32