Hardware Address Binding Memory Allocation References. Physical Memory. Daniel Bosk 1

Size: px
Start display at page:

Download "Hardware Address Binding Memory Allocation References. Physical Memory. Daniel Bosk 1"

Transcription

1 Physical Memory Daniel Bosk 1 Department of Information and Communication Systems (ICS), Mid Sweden University, Sundsvall. physmem.tex :20:05Z jimahl 1 1 This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported license. To view a copy of this license, visit

2 Overview 1 Hardware Basic hardware 2 Address Binding Binding memory in a process Relocation registers 3 Memory Allocation Contiguous Allocation Non-Contiguous Allocation Segmentation

3 3 Literature This lecture will give an overview of physical memory management. It gives an overview of Chapter 8 Memory-Management Strategies"in [SGG13a]

4 Overview 1 Hardware Basic hardware 2 Address Binding Binding memory in a process Relocation registers 3 Memory Allocation Contiguous Allocation Non-Contiguous Allocation Segmentation

5 Basic hardware operating system process process process base limit Figure: Memory layout with base and limit for logical address space. Image: [SGG13b].

6 Basic hardware base base limit CPU address yes < yes no no trap to operating system monitor addressing error memory Figure: A schematic of hardware protection for base and limit memory protection. Image: [SGG13b].

7 Overview 1 Hardware Basic hardware 2 Address Binding Binding memory in a process Relocation registers 3 Memory Allocation Contiguous Allocation Non-Contiguous Allocation Segmentation

8 8 Binding memory in a process source program compiler or assembler compile time other object modules object module linkage editor system library load module load time dynamically loaded system library dynamic linking loader in-memory binary memory image execution time (run time) Figure: An overview of all steps to create a program. Image: [SGG13b].

9 9 Relocation registers relocation register CPU logical address physical address memory MMU Figure: An illustration of a relocation register. Image: [SGG13b].

10 10 Relocation registers limit register relocation register CPU logical address yes physical address memory no trap: addressing error Figure: A relocation register with base and limit properties. Image: [SGG13b].

11 Overview 1 Hardware Basic hardware 2 Address Binding Binding memory in a process Relocation registers 3 Memory Allocation Contiguous Allocation Non-Contiguous Allocation Segmentation

12 12 Contiguous Allocation Processes are placed in contiguous memory spans. External fragmentation, and the 50-percent rule. Migitate the problem with: Compaction, and Swapping.

13 13 Contiguous Allocation First-fit Best-fit Worst-fit

14 14 Non-Contiguous Allocation Segmentation

15 15 Split the logical address into two parts: page number, and page offset (displacement). Fix the size of the pages in bits of the address, i.e. the size is a power of two. E.g. page size is the last 10 bits, then each page will be 2 10 bytes or 1 KiB in size. The size of the page must be equal to the size of the physical counterpart, the frame. The frame size, and hence the page size, are determined by the hardware. Each page is mapped to a frame, this mapping is kept in a page table.

16 16 f logical address physical address f CPU p d f d f p f page table physical memory Figure: An overview of paging. Image: [SGG13b].

17 17 frame number page 0 page 1 page 2 page page table page 0 page 2 logical memory 4 page page 3 physical memory Figure: A pagetable. Image: [SGG13b].

18 a b c d e f g h i j k l m n o p logical memory page table i j k l m n o p a b c d e f g h physical memory Figure: Allocated memory using paging. Image: [SGG13b].

19 free-frame list free-frame list page 1 14 page 0 15 page 0 page 1 page 2 page 3 new process page 0 page 1 page 2 page 3 new process page new-process page table page 3 21 (a) (b) Figure: Before and after allocating a new process to memory. Image: [SGG13b].

20 20 The page table is usually stored by the OS in the process s PCB. The dispatcher loads the process s page table into the hardware, if the page table is sufficiently small. Bigger tables must be kept in the memory. A page table base register then points to the page table s position in memory. However, this requires a memory lookup, i.e. each memory reference requires two references! The solution is to add a translation look-aside buffer (TLB), a very fast hardware cache.

21 21 CPU logical address p d page frame number number TLB TLB hit f d physical address TLB miss p f physical memory page table Figure: with a TLB. Image: [SGG13b].

22 22 Some TLBs have address-space identifications (ASIDs). ASIDs allows the TLB to handle pages for different processes simultaneously. Hence we don t need to clear it every context switch.

23 23 One can compute the effective access time for memory. Effective memory-access time is the average time it takes for each memory access, i.e. with regards to TLB hits and misses.

24 Effective memory-access time We can compute the effective access time t by t = (1 p) (t t + t m ) + p (t t + t m + t m ), where p is the probability of a TLB miss, t t is the time for a TLB lookup, t m is the time for a memory access.

25 25 We must have some protection for the pages of a process. What happens when the page table is larger than necessary for a specific process? Consider a system with a 14-bit address space, a process with the logical address range 0 to 10468, and a page size of 2 KiB...

26 ,468 12,287 page 0 page 1 page 2 page 3 page 4 page 5 frame number v v v v v v i i page table valid invalid bit page 0 page 1 page 2 page 3 page 4 page 5 page n Figure: with valid-bits. Image: [SGG13b].

27 27 We can also add additional bits like this. We can have bits for specifying whether reading, writing or execution is allowed on these pages. This way we can implement execution prevention for certain memory regions, e.g. where the web browser stores data downloaded from the Web. This way several processes can share read-only pages, hence requiring less memory.

28 28 ed 1 ed 2 ed data 1 data 3 data 1 process P 1 page table for P 1 ed 1 ed 2 ed ed 1 ed 2 ed 3 ed 1 ed 2 ed 3 data page table for P 3 data 2 process P 2 page table for P data 2 process P 3 Figure: An example of shared pages. Image: [SGG13b].

29 29 What happens when we get huge logical address spaces, e.g. 32 or 64-bit addresses? With a page size of 4 KiB (i.e. 12 bits) the worst case scenario in a 32-bit system is a page table of 4 MiB in size for each process! If we need to allocate this contiguously in memory we re back to the original problem we wanted to solve. Well, we have a solution for that: paging! We page the page table...

30 30 logical address p 1 p 2 d p 1 p 2 outer page table d page of page table Figure: Hierarchical paging. Image: [SGG13b].

31 31 0 outer page table page of page table page table memory Figure: Hierarchical paging, overview. Image: [SGG13b].

32 32 Now each part of the page table fits in a page. Hence we don t need contiguous allocation anymore. However, this doesn t work for spaces even as small as 64 bits.

33 33 logical address p d r d physical address hash function q s p r physical memory hash table Figure: using hashing. Image: [SGG13b].

34 Another way of saving space is to use an inverted page table. Here we have one entry per frame, not per page. Then we map which process has allocated it and to which page.

35 35 CPU logical address pid p d i d physical address physical memory search i pid p page table Figure: Inverted paging. Image: [SGG13b].

36 36 Segmentation subroutine stack symbol table Sqrt main program logical address Figure: Segments. Image: [SGG13b].

37 37 Segmentation s limit base CPU s d segment table yes < + no trap: addressing error physical memory Figure: Segmentation hardware. Image: [SGG13b].

38 38 Segmentation subroutine stack 1400 segment 0 segment 3 symbol table segment Sqrt main program segment limit base segment 3 segment 1 segment 2 segment table 4300 segment logical address space segment segment physical memory Figure: Segment mapping. Image: [SGG13b].

39 Referenser I Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne. Operating System Concepts. 9th ed. International Student Version. Hoboken, N.J.: John Wiley & Sons Inc, Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne. Operating System Concepts. 9th ed. Hoboken, N.J.: John Wiley & Sons Inc, 2013.

Memory Management. CSCI 315 Operating Systems Design Department of Computer Science

Memory Management. CSCI 315 Operating Systems Design Department of Computer Science Memory Management CSCI 315 Operating Systems Design Department of Computer Science Notice: The slides for this lecture are based on those from Operating Systems Concepts, 9th ed., by Silberschatz, Galvin,

More information

CSE 4/521 Introduction to Operating Systems. Lecture 14 Main Memory III (Paging, Structure of Page Table) Summer 2018

CSE 4/521 Introduction to Operating Systems. Lecture 14 Main Memory III (Paging, Structure of Page Table) Summer 2018 CSE 4/521 Introduction to Operating Systems Lecture 14 Main Memory III (Paging, Structure of Page Table) Summer 2018 Overview Objective: To discuss how paging works in contemporary computer systems. Paging

More information

Chapter 8: Main Memory

Chapter 8: Main Memory Chapter 8: Main Memory Operating System Concepts 8 th Edition,! Silberschatz, Galvin and Gagne 2009! Chapter 8: Memory Management Background" Swapping " Contiguous Memory Allocation" Paging" Structure

More information

Chapter 8: Memory Management. Operating System Concepts with Java 8 th Edition

Chapter 8: Memory Management. Operating System Concepts with Java 8 th Edition Chapter 8: Memory Management 8.1 Silberschatz, Galvin and Gagne 2009 Background Program must be brought (from disk) into memory and placed within a process for it to be run Main memory and registers are

More information

Chapter 8: Main Memory

Chapter 8: Main Memory Chapter 8: Main Memory Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Example: The Intel Pentium 8.2 Silberschatz, Galvin

More information

Chapter 8: Memory- Management Strategies. Operating System Concepts 9 th Edition

Chapter 8: Memory- Management Strategies. Operating System Concepts 9 th Edition Chapter 8: Memory- Management Strategies Operating System Concepts 9 th Edition Silberschatz, Galvin and Gagne 2013 Chapter 8: Memory Management Strategies Background Swapping Contiguous Memory Allocation

More information

Module 8: Memory Management

Module 8: Memory Management Module 8: Memory Management Background Logical versus Physical Address Space Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging Operating System Concepts 8.1 Silberschatz and Galvin

More information

Chapter 7: Main Memory. Operating System Concepts Essentials 8 th Edition

Chapter 7: Main Memory. Operating System Concepts Essentials 8 th Edition Chapter 7: Main Memory Operating System Concepts Essentials 8 th Edition Silberschatz, Galvin and Gagne 2011 Chapter 7: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure

More information

Chapter 8 Memory Management

Chapter 8 Memory Management Chapter 8 Memory Management Da-Wei Chang CSIE.NCKU Source: Abraham Silberschatz, Peter B. Galvin, and Greg Gagne, "Operating System Concepts", 9th Edition, Wiley. 1 Outline Background Swapping Contiguous

More information

Chapter 8: Memory Management Strategies

Chapter 8: Memory Management Strategies Chapter 8: Memory- Management Strategies, Silberschatz, Galvin and Gagne 2009 Chapter 8: Memory Management Strategies Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table

More information

Logical versus Physical Address Space

Logical versus Physical Address Space CHAPTER 8: MEMORY MANAGEMENT Background Logical versus Physical Address Space Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging Operating System Concepts, Addison-Wesley 1994

More information

CS420: Operating Systems. Paging and Page Tables

CS420: Operating Systems. Paging and Page Tables Paging and Page Tables James Moscola Department of Physical Sciences York College of Pennsylvania Based on Operating System Concepts, 9th Edition by Silberschatz, Galvin, Gagne Paging Paging is a memory-management

More information

Outlook. Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Example: The Intel Pentium

Outlook. Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Example: The Intel Pentium Main Memory Outlook Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Example: The Intel Pentium 2 Backgound Background So far we considered how to share

More information

6 - Main Memory EECE 315 (101) ECE UBC 2013 W2

6 - Main Memory EECE 315 (101) ECE UBC 2013 W2 6 - Main Memory EECE 315 (101) ECE UBC 2013 W2 Acknowledgement: This set of slides is partly based on the PPTs provided by the Wiley s companion website (including textbook images, when not explicitly

More information

Chapter 8: Memory- Management Strategies. Operating System Concepts 9 th Edition

Chapter 8: Memory- Management Strategies. Operating System Concepts 9 th Edition Chapter 8: Memory- Management Strategies Operating System Concepts 9 th Edition Silberschatz, Galvin and Gagne 2013 Chapter 8: Memory Management Strategies Background Swapping Contiguous Memory Allocation

More information

Chapter 8: Memory- Management Strategies

Chapter 8: Memory- Management Strategies Chapter 8: Memory Management Strategies Chapter 8: Memory- Management Strategies Background Swapping Contiguous Memory Allocation Segmentation Paging Structure of the Page Table Example: The Intel 32 and

More information

Memory Management. Contents: Memory Management. How to generate code? Background

Memory Management. Contents: Memory Management. How to generate code? Background TDIU11 Operating systems Contents: Memory Management Memory Management [SGG7/8/9] Chapter 8 Background Relocation Dynamic loading and linking Swapping Contiguous Allocation Paging Segmentation Copyright

More information

Chapter 8: Main Memory. Operating System Concepts 9 th Edition

Chapter 8: Main Memory. Operating System Concepts 9 th Edition Chapter 8: Main Memory Silberschatz, Galvin and Gagne 2013 Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Segmentation Paging Structure of the Page Table Example: The Intel

More information

Memory Management. Dr. Yingwu Zhu

Memory Management. Dr. Yingwu Zhu Memory Management Dr. Yingwu Zhu Big picture Main memory is a resource A process/thread is being executing, the instructions & data must be in memory Assumption: Main memory is infinite Allocation of memory

More information

Chapter 8: Main Memory

Chapter 8: Main Memory Chapter 8: Main Memory Silberschatz, Galvin and Gagne 2013 Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Segmentation Paging Structure of the Page Table Example: The Intel

More information

Memory Management. Memory Management

Memory Management. Memory Management Memory Management Gordon College Stephen Brinton Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging 1 Background Program must be brought into memory

More information

CS370 Operating Systems

CS370 Operating Systems CS370 Operating Systems Colorado State University Yashwant K Malaiya Fall 2017 Lecture 20 Main Memory Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 Pages Pages and frames Page

More information

Memory Management. Dr. Yingwu Zhu

Memory Management. Dr. Yingwu Zhu Memory Management Dr. Yingwu Zhu Big picture Main memory is a resource A process/thread is being executing, the instructions & data must be in memory Assumption: Main memory is super big to hold a program

More information

Performance of Various Levels of Storage. Movement between levels of storage hierarchy can be explicit or implicit

Performance of Various Levels of Storage. Movement between levels of storage hierarchy can be explicit or implicit Memory Management All data in memory before and after processing All instructions in memory in order to execute Memory management determines what is to be in memory Memory management activities Keeping

More information

I.-C. Lin, Assistant Professor. Textbook: Operating System Principles 7ed CHAPTER 8: MEMORY

I.-C. Lin, Assistant Professor. Textbook: Operating System Principles 7ed CHAPTER 8: MEMORY I.-C. Lin, Assistant Professor. Textbook: Operating System Principles 7ed CHAPTER 8: MEMORY MANAGEMENT Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of

More information

Chapter 9: Memory Management. Background

Chapter 9: Memory Management. Background 1 Chapter 9: Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging 9.1 Background Program must be brought into memory and placed within a process for

More information

Part Three - Memory Management. Chapter 8: Memory-Management Strategies

Part Three - Memory Management. Chapter 8: Memory-Management Strategies Part Three - Memory Management Chapter 8: Memory-Management Strategies Chapter 8: Memory-Management Strategies 8.1 Background 8.2 Swapping 8.3 Contiguous Memory Allocation 8.4 Segmentation 8.5 Paging 8.6

More information

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

I.-C. Lin, Assistant Professor. Textbook: Operating System Concepts 8ed CHAPTER 8: MEMORY I.-C. Lin, Assistant Professor. Textbook: Operating System Concepts 8ed CHAPTER 8: MEMORY MANAGEMENT Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of the

More information

Main Memory (Part II)

Main Memory (Part II) Main Memory (Part II) Amir H. Payberah amir@sics.se Amirkabir University of Technology (Tehran Polytechnic) Amir H. Payberah (Tehran Polytechnic) Main Memory 1393/8/17 1 / 50 Reminder Amir H. Payberah

More information

Chapter 9 Memory Management Main Memory Operating system concepts. Sixth Edition. Silberschatz, Galvin, and Gagne 8.1

Chapter 9 Memory Management Main Memory Operating system concepts. Sixth Edition. Silberschatz, Galvin, and Gagne 8.1 Chapter 9 Memory Management Main Memory Operating system concepts. Sixth Edition. Silberschatz, Galvin, and Gagne 8.1 Chapter 9: Memory Management Background Swapping Contiguous Memory Allocation Segmentation

More information

CS307: Operating Systems

CS307: Operating Systems CS307: Operating Systems Chentao Wu 吴晨涛 Associate Professor Dept. of Computer Science and Engineering Shanghai Jiao Tong University SEIEE Building 3-513 wuct@cs.sjtu.edu.cn Download Lectures ftp://public.sjtu.edu.cn

More information

8.1 Background. Part Four - Memory Management. Chapter 8: Memory-Management Management Strategies. Chapter 8: Memory Management

8.1 Background. Part Four - Memory Management. Chapter 8: Memory-Management Management Strategies. Chapter 8: Memory Management Part Four - Memory Management 8.1 Background Chapter 8: Memory-Management Management Strategies Program must be brought into memory and placed within a process for it to be run Input queue collection of

More information

Lecture 8 Memory Management Strategies (chapter 8)

Lecture 8 Memory Management Strategies (chapter 8) Bilkent University Department of Computer Engineering CS342 Operating Systems Lecture 8 Memory Management Strategies (chapter 8) Dr. İbrahim Körpeoğlu http://www.cs.bilkent.edu.tr/~korpe 1 References The

More information

Module 8: Memory Management

Module 8: Memory Management Module 8: Memory Management Background Logical versus Physical Address Space Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging 8.1 Background Program must be brought into memory

More information

Module 9: Memory Management. Background. Binding of Instructions and Data to Memory

Module 9: Memory Management. Background. Binding of Instructions and Data to Memory Module 9: Memory Management Background Logical versus Physical Address Space Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging 9.1 Background Program must be brought into memory

More information

Operating Systems. 09. Memory Management Part 1. Paul Krzyzanowski. Rutgers University. Spring 2015

Operating Systems. 09. Memory Management Part 1. Paul Krzyzanowski. Rutgers University. Spring 2015 Operating Systems 09. Memory Management Part 1 Paul Krzyzanowski Rutgers University Spring 2015 March 9, 2015 2014-2015 Paul Krzyzanowski 1 CPU Access to Memory The CPU reads instructions and reads/write

More information

Goals of Memory Management

Goals of Memory Management Memory Management Goals of Memory Management Allocate available memory efficiently to multiple processes Main functions Allocate memory to processes when needed Keep track of what memory is used and what

More information

Chapter 9 Memory Management

Chapter 9 Memory Management 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

More information

Virtual Memory. CSCI 315 Operating Systems Design Department of Computer Science

Virtual Memory. CSCI 315 Operating Systems Design Department of Computer Science Virtual Memory CSCI 315 Operating Systems Design Department of Computer Science Notice: The slides for this lecture have been largely based on those from an earlier edition of the course text Operating

More information

Memory Management. Memory

Memory Management. Memory Memory Management 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

More information

CS370: Operating Systems [Spring 2017] Dept. Of Computer Science, Colorado State University

CS370: Operating Systems [Spring 2017] Dept. Of Computer Science, Colorado State University Frequently asked questions from the previous class survey CS 370: OPERATING SYSTEMS [MEMORY MANAGEMENT] Shrideep Pallickara Computer Science Colorado State University MS-DOS.COM? How does performing fast

More information

Memory Management (2)

Memory Management (2) EECS 3221.3 Operating System Fundamentals No.9 Memory Management (2) Prof. Hui Jiang Dept of Electrical Engineering and Computer Science, York University Memory Management Approaches Contiguous Memory

More information

CHAPTER 8: MEMORY MANAGEMENT. By I-Chen Lin Textbook: Operating System Concepts 9th Ed.

CHAPTER 8: MEMORY MANAGEMENT. By I-Chen Lin Textbook: Operating System Concepts 9th Ed. CHAPTER 8: MEMORY MANAGEMENT By I-Chen Lin Textbook: Operating System Concepts 9th Ed. Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Segmentation Paging Structure of the

More information

CS3600 SYSTEMS AND NETWORKS

CS3600 SYSTEMS AND NETWORKS CS3600 SYSTEMS AND NETWORKS SPRING 2013 Lecture 13: Paging Prof. Alan Mislove (amislove@ccs.neu.edu) Paging Physical address space of a process can be noncontiguous; process is allocated physical memory

More information

Operating Systems. Designed and Presented by Dr. Ayman Elshenawy Elsefy

Operating Systems. Designed and Presented by Dr. Ayman Elshenawy Elsefy Operating Systems Designed and Presented by Dr. Ayman Elshenawy Elsefy Dept. of Systems & Computer Eng.. AL-AZHAR University Website : eaymanelshenawy.wordpress.com Email : eaymanelshenawy@yahoo.com Reference

More information

Chapter 8: Memory-Management Strategies

Chapter 8: Memory-Management Strategies Chapter 8: Memory-Management Strategies Chapter 8: Memory Management Strategies Background Swapping Contiguous Memory Allocation Segmentation Paging Structure of the Page Table Example: The Intel 32 and

More information

Basic Memory Management. Basic Memory Management. Address Binding. Running a user program. Operating Systems 10/14/2018 CSC 256/456 1

Basic Memory Management. Basic Memory Management. Address Binding. Running a user program. Operating Systems 10/14/2018 CSC 256/456 1 Basic Memory Management Program must be brought into memory and placed within a process for it to be run Basic Memory Management CS 256/456 Dept. of Computer Science, University of Rochester Mono-programming

More information

CS370 Operating Systems

CS370 Operating Systems CS370 Operating Systems Colorado State University Yashwant K Malaiya Spring 2018 L17 Main Memory Slides based on Text by Silberschatz, Galvin, Gagne Various sources 1 1 FAQ Was Great Dijkstra a magician?

More information

Chapter 8 & Chapter 9 Main Memory & Virtual Memory

Chapter 8 & Chapter 9 Main Memory & Virtual Memory Chapter 8 & Chapter 9 Main Memory & Virtual Memory 1. Various ways of organizing memory hardware. 2. Memory-management techniques: 1. Paging 2. Segmentation. Introduction Memory consists of a large array

More information

CHAPTER 8 - MEMORY MANAGEMENT STRATEGIES

CHAPTER 8 - MEMORY MANAGEMENT STRATEGIES CHAPTER 8 - MEMORY MANAGEMENT STRATEGIES OBJECTIVES Detailed description of various ways of organizing memory hardware Various memory-management techniques, including paging and segmentation To provide

More information

Chapter 8: Memory Management

Chapter 8: Memory Management Chapter 8: Memory Management Chapter 8: Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging 8.2 Background Program must be brought into memory and placed

More information

Memory Management. Reading: Silberschatz chapter 9 Reading: Stallings. chapter 7 EEL 358

Memory Management. Reading: Silberschatz chapter 9 Reading: Stallings. chapter 7 EEL 358 Memory Management Reading: Silberschatz chapter 9 Reading: Stallings chapter 7 1 Outline Background Issues in Memory Management Logical Vs Physical address, MMU Dynamic Loading Memory Partitioning Placement

More information

Chapter 8: Main Memory

Chapter 8: Main Memory Chapter 8: Main Memory Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Segmentation Paging Structure of the Page Table Example: The Intel 32 and 64-bit Architectures Example:

More information

Memory Management and Protection

Memory Management and Protection Part IV Memory Management and Protection Sadeghi, Cubaleska RUB 2008-09 Course Operating System Security Memory Management and Protection Main Memory Virtual Memory Roadmap of Chapter 4 Main Memory Background

More information

Main Memory. Electrical and Computer Engineering Stephen Kim ECE/IUPUI RTOS & APPS 1

Main Memory. Electrical and Computer Engineering Stephen Kim ECE/IUPUI RTOS & APPS 1 Main Memory Electrical and Computer Engineering Stephen Kim (dskim@iupui.edu) ECE/IUPUI RTOS & APPS 1 Main Memory Background Swapping Contiguous allocation Paging Segmentation Segmentation with paging

More information

Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation

Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Basic Hardware Address Binding Logical VS Physical Address Space Dynamic Loading Dynamic Linking and Shared

More information

Memory management. Last modified: Adaptation of Silberschatz, Galvin, Gagne slides for the textbook Applied Operating Systems Concepts

Memory management. Last modified: Adaptation of Silberschatz, Galvin, Gagne slides for the textbook Applied Operating Systems Concepts Memory management Last modified: 26.04.2016 1 Contents Background Logical and physical address spaces; address binding Overlaying, swapping Contiguous Memory Allocation Segmentation Paging Structure of

More information

Lecture 21: Virtual Memory. Spring 2018 Jason Tang

Lecture 21: Virtual Memory. Spring 2018 Jason Tang Lecture 21: Virtual Memory Spring 2018 Jason Tang 1 Topics Virtual addressing Page tables Translation lookaside buffer 2 Computer Organization Computer Processor Memory Devices Control Datapath Input Output

More information

CS307 Operating Systems Main Memory

CS307 Operating Systems Main Memory CS307 Main Memory Fan Wu Department of Computer Science and Engineering Shanghai Jiao Tong University Spring 2018 Background Program must be brought (from disk) into memory and placed within a process

More information

Chapter 8: Memory- Manage g me m nt n S tra r t a e t gie i s

Chapter 8: Memory- Manage g me m nt n S tra r t a e t gie i s Chapter 8: Memory- Management Strategies Chapter 8: Memory Management Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Example: The Intel Pentium 2009/12/16

More information

Today: Segmentation. Last Class: Paging. Costs of Using The TLB. The Translation Look-aside Buffer (TLB)

Today: Segmentation. Last Class: Paging. Costs of Using The TLB. The Translation Look-aside Buffer (TLB) Last Class: Paging Process generates virtual addresses from 0 to Max. OS divides the process onto pages; manages a page table for every process; and manages the pages in memory Hardware maps from virtual

More information

Course: Operating Systems Instructor: M Umair. M Umair

Course: Operating Systems Instructor: M Umair. M Umair Course: Operating Systems Instructor: M Umair Memory Management Introduction { Ref: Operating System Concepts 8th Edition Abraham Silberschatz, Greg Gagne, Peter B. Galvin } Address Binding Addresses in

More information

File Systems. OS Overview I/O. Swap. Management. Operations CPU. Hard Drive. Management. Memory. Hard Drive. CSI3131 Topics. Structure.

File Systems. OS Overview I/O. Swap. Management. Operations CPU. Hard Drive. Management. Memory. Hard Drive. CSI3131 Topics. Structure. File Systems I/O Management Hard Drive Management Virtual Memory Swap Memory Management Storage and I/O Introduction CSI3131 Topics Process Management Computing Systems Memory CPU Peripherals Processes

More information

Basic Memory Management

Basic Memory Management Basic Memory Management CS 256/456 Dept. of Computer Science, University of Rochester 10/15/14 CSC 2/456 1 Basic Memory Management Program must be brought into memory and placed within a process for it

More information

Chapter 8 Main Memory

Chapter 8 Main Memory COP 4610: Introduction to Operating Systems (Spring 2014) Chapter 8 Main Memory Zhi Wang Florida State University Contents Background Swapping Contiguous memory allocation Paging Segmentation OS examples

More information

CS370: Operating Systems [Spring 2016] Dept. Of Computer Science, Colorado State University

CS370: Operating Systems [Spring 2016] Dept. Of Computer Science, Colorado State University Frequently asked questions from the previous class survey CS 7: OPERATING SYSTEMS [MEMORY MANAGEMENT] Shrideep Pallickara Computer Science Colorado State University TLB Does the TLB work in practice? n

More information

CSE 421/521 - Operating Systems Fall Lecture - XII Main Memory Management. Tevfik Koşar. University at Buffalo. October 18 th, 2012.

CSE 421/521 - Operating Systems Fall Lecture - XII Main Memory Management. Tevfik Koşar. University at Buffalo. October 18 th, 2012. CSE 421/521 - Operating Systems Fall 2012 Lecture - XII Main Memory Management Tevfik Koşar University at Buffalo October 18 th, 2012 1 Roadmap Main Memory Management Fixed and Dynamic Memory Allocation

More information

CS420: Operating Systems

CS420: Operating Systems Main Memory James Moscola Department of Engineering & Computer Science York College of Pennsylvania Based on Operating System Concepts, 9th Edition by Silberschatz, Galvin, Gagne Background Program must

More information

Chapter 8: Memory Management. Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging

Chapter 8: Memory Management. Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging Chapter 8: Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging 1 Background Memory management is crucial in better utilizing one of the most important

More information

Chapter 8 Main Memory

Chapter 8 Main Memory Chapter 8 Main Memory 8.1, 8.2, 8.3, 8.4, 8.5 Chapter 9 Virtual memory 9.1, 9.2, 9.3 https://www.akkadia.org/drepper/cpumemory.pdf Images from Silberschatz Pacific University 1 How does the OS manage memory?

More information

Memory Management. Minsoo Ryu. Real-Time Computing and Communications Lab. Hanyang University.

Memory Management. Minsoo Ryu. Real-Time Computing and Communications Lab. Hanyang University. Memory Management Minsoo Ryu Real-Time Computing and Communications Lab. Hanyang University msryu@hanyang.ac.kr Topics Covered Introduction Memory Allocation and Fragmentation Address Translation Paging

More information

Memory Management Minsoo Ryu Real-Time Computing and Communications Lab. Hanyang University

Memory Management Minsoo Ryu Real-Time Computing and Communications Lab. Hanyang University Memory Management Minsoo Ryu Real-Time Computing and Communications Lab. Hanyang University msryu@hanyang.ac.kr Topics Covered Introduction Memory Allocation and Fragmentation Address Translation Paging

More information

Memory Management 9th Week

Memory Management 9th Week Department of Electrical Engineering and Information Technology Faculty of Engineering Universitas Gadjah Mada, Indonesia Operating System - TIF 206 Memory Management 9th Week Sunu Wibirama Copyright 2011

More information

CS370: Operating Systems [Spring 2017] Dept. Of Computer Science, Colorado State University

CS370: Operating Systems [Spring 2017] Dept. Of Computer Science, Colorado State University Frequently asked questions from the previous class survey CS 370: OPERATING SYSTEMS [MEMORY MANAGEMENT] Matrices in Banker s algorithm Max, need, allocated Shrideep Pallickara Computer Science Colorado

More information

Principles of Operating Systems

Principles of Operating Systems Principles of Operating Systems Lecture 18-20 - Main Memory Ardalan Amiri Sani (ardalan@uci.edu) [lecture slides contains some content adapted from previous slides by Prof. Nalini Venkatasubramanian, and

More information

memory management Vaibhav Bajpai

memory management Vaibhav Bajpai memory management Vaibhav Bajpai OS 2013 motivation virtualize resources: multiplex CPU multiplex memory (CPU scheduling) (memory management) why manage memory? controlled overlap processes should NOT

More information

Main Memory. CISC3595, Spring 2015 X. Zhang Fordham University

Main Memory. CISC3595, Spring 2015 X. Zhang Fordham University Main Memory CISC3595, Spring 2015 X. Zhang Fordham University 1 Memory Management! Background!! Contiguous Memory Allocation!! Paging!! Structure of the Page Table!! Segmentation!! Example: The Intel Pentium

More information

CSE 4/521 Introduction to Operating Systems. Lecture 15 Virtual Memory I (Background, Demand Paging) Summer 2018

CSE 4/521 Introduction to Operating Systems. Lecture 15 Virtual Memory I (Background, Demand Paging) Summer 2018 CSE 4/521 Introduction to Operating Systems Lecture 15 Virtual Memory I (Background, Demand Paging) Summer 2018 Overview Objective: To describe the benefits of a virtual memory system. To explain the concept

More information

CS 3733 Operating Systems:

CS 3733 Operating Systems: CS 3733 Operating Systems: Topics: Memory Management (SGG, Chapter 08) Instructor: Dr Dakai Zhu Department of Computer Science @ UTSA 1 Reminders Assignment 2: extended to Monday (March 5th) midnight:

More information

Frequently asked questions from the previous class survey

Frequently asked questions from the previous class survey CS 370: OPERATING SYSTEMS [MEMORY MANAGEMENT] Shrideep Pallickara Computer Science Colorado State University L20.1 Frequently asked questions from the previous class survey Virtual addresses L20.2 SLIDES

More information

Chapter 8: Memory Management

Chapter 8: Memory Management Chapter 8: Memory Management Chapter 8: Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging 8.2 Silberschatz, Galvin and Gagne 2005 Background Program/Code

More information

CS399 New Beginnings. Jonathan Walpole

CS399 New Beginnings. Jonathan Walpole CS399 New Beginnings Jonathan Walpole Memory Management Memory Management Memory a linear array of bytes - Holds O.S. and programs (processes) - Each cell (byte) is named by a unique memory address Recall,

More information

16 Sharing Main Memory Segmentation and Paging

16 Sharing Main Memory Segmentation and Paging Operating Systems 64 16 Sharing Main Memory Segmentation and Paging Readings for this topic: Anderson/Dahlin Chapter 8 9; Siberschatz/Galvin Chapter 8 9 Simple uniprogramming with a single segment per

More information

Topics: Memory Management (SGG, Chapter 08) 8.1, 8.2, 8.3, 8.5, 8.6 CS 3733 Operating Systems

Topics: Memory Management (SGG, Chapter 08) 8.1, 8.2, 8.3, 8.5, 8.6 CS 3733 Operating Systems Topics: Memory Management (SGG, Chapter 08) 8.1, 8.2, 8.3, 8.5, 8.6 CS 3733 Operating Systems Instructor: Dr. Turgay Korkmaz Department Computer Science The University of Texas at San Antonio Office: NPB

More information

Operating Systems Unit 6. Memory Management

Operating Systems Unit 6. Memory Management Unit 6 Memory Management Structure 6.1 Introduction Objectives 6.2 Logical versus Physical Address Space 6.3 Swapping 6.4 Contiguous Allocation Single partition Allocation Multiple Partition Allocation

More information

Chapter 8: Memory- Management Strategies Dr. Varin Chouvatut

Chapter 8: Memory- Management Strategies Dr. Varin Chouvatut Part I: Overview Part II: Process Management Part III : Storage Management Chapter 8: Memory- Management Strategies Dr. Varin Chouvatut, Silberschatz, Galvin and Gagne 2010 Chapter 8: Memory Management

More information

Compile: compiler. Load: loader. compiler linker loader memory. source object load code module module 2

Compile: compiler. Load: loader. compiler linker loader memory. source object load code module module 2 Part III Storage Management Chapter 8: Memory Management Fall 2010 1 Address Generation Address generation has three stages: Compile: compiler Link: linker or linkage editor Load: loader compiler linker

More information

P r a t t hr h ee e : e M e M m e o m r o y y M a M n a a n g a e g m e e m n e t 8.1/72

P r a t t hr h ee e : e M e M m e o m r o y y M a M n a a n g a e g m e e m n e t 8.1/72 Part three: Memory Management programs, together with the data they access, must be in main memory (at least partially) during execution. the computer keeps several processes in memory. Many memory-management

More information

Paging & Segmentation

Paging & Segmentation & Frédéric Haziza Department of Computer Systems Uppsala University Spring 2008 Outline 1 Paging Implementation Protection Sharing 2 Setup Implementation 2 OSKomp 08 Paging & Definition

More information

csci 3411: Operating Systems

csci 3411: Operating Systems csci 3411: Operating Systems Memory Management II Gabriel Parmer Slides adapted from Silberschatz and West Each Process has its Own Little World Virtual Address Space Picture from The

More information

CS5460: Operating Systems Lecture 14: Memory Management (Chapter 8)

CS5460: Operating Systems Lecture 14: Memory Management (Chapter 8) CS5460: Operating Systems Lecture 14: Memory Management (Chapter 8) Important from last time We re trying to build efficient virtual address spaces Why?? Virtual / physical translation is done by HW and

More information

15 Sharing Main Memory Segmentation and Paging

15 Sharing Main Memory Segmentation and Paging Operating Systems 58 15 Sharing Main Memory Segmentation and Paging Readings for this topic: Anderson/Dahlin Chapter 8 9; Siberschatz/Galvin Chapter 8 9 Simple uniprogramming with a single segment per

More information

12: Memory Management

12: Memory Management 12: Memory Management Mark Handley Address Binding Program goes through multiple steps from compilation to execution. At some stage, addresses in the program must be bound to physical memory addresses:

More information

COSC Operating Systems Design, Fall 2001, Byunggu Yu. Chapter 9 Memory Management (Lecture Note #8) 1. Background

COSC Operating Systems Design, Fall 2001, Byunggu Yu. Chapter 9 Memory Management (Lecture Note #8) 1. Background COSC4740 01 Operating Systems Design, Fall 2001, Byunggu Yu Chapter 9 Memory Management (Lecture Note #8) 1. Background The computer programs, together with the data they access, must be in main memory

More information

Main Memory Yi Shi Fall 2017 Xi an Jiaotong University

Main Memory Yi Shi Fall 2017 Xi an Jiaotong University Main Memory Yi Shi Fall 2017 Xi an Jiaotong University Goals Background Swapping Contiguous Memory Allocation Segmentation Paging Structure of the Page Table Background Program must be brought (from disk)

More information

Roadmap. Tevfik Koşar. CSC Operating Systems Spring Lecture - XII Main Memory - II. Louisiana State University

Roadmap. Tevfik Koşar. CSC Operating Systems Spring Lecture - XII Main Memory - II. Louisiana State University CSC 4103 - Operating Systems Spring 2007 Lecture - XII Main Memory - II Tevfik Koşar Louisiana State University March 8 th, 2007 1 Roadmap Dynamic Loading & Linking Contiguous Memory Allocation Fragmentation

More information

Main Memory (II) Operating Systems. Autumn CS4023

Main Memory (II) Operating Systems. Autumn CS4023 Operating Systems Autumn 2017-2018 Outline 1 Main Memory (II) Outline Main Memory (II) 1 Main Memory (II) Paging Main Memory (II) Physical address space of a process can be noncontiguous; process is allocated

More information

! What is main memory? ! What is static and dynamic allocation? ! What is segmentation? Maria Hybinette, UGA. High Address (0x7fffffff) !

! What is main memory? ! What is static and dynamic allocation? ! What is segmentation? Maria Hybinette, UGA. High Address (0x7fffffff) ! Memory Questions? CSCI [4 6]730 Operating Systems Main Memory! What is main memory?! How does multiple processes share memory space?» Key is how do they refer to memory addresses?! What is static and dynamic

More information

Memory Management Cache Base and Limit Registers base limit Binding of Instructions and Data to Memory Compile time absolute code Load time

Memory Management Cache Base and Limit Registers base limit Binding of Instructions and Data to Memory Compile time absolute code Load time Memory Management To provide a detailed description of various ways of organizing memory hardware To discuss various memory-management techniques, including paging and segmentation To provide a detailed

More information

SHANDONG UNIVERSITY 1

SHANDONG UNIVERSITY 1 Chapter 8 Main Memory SHANDONG UNIVERSITY 1 Contents Background Swapping Contiguous Memory Allocation Paging Structure of the Page Table Segmentation Example: The Intel Pentium SHANDONG UNIVERSITY 2 Objectives

More information