ch08 - Chapter 8: Memory Management Chapter Chapter 8:...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 8: Memory Management Chapter 8: Memory Management
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Chapter 8: Memory Management Chapter 8: Memory Management Background Swapping Contiguous Allocation Paging Segmentation Segmentation with Paging
Background image of page 2
8.3 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Background Background Program must be brought into memory and placed within a process for it to be run Input queue – collection of processes on the disk that are waiting to be brought into memory to run the program User programs go through several steps before being run
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8.4 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Binding of Instructions and Data to Memory Binding of Instructions and Data to Memory Compile time : If memory location known a priori, absolute code can be generated; must recompile code if starting location changes Load time : Must generate relocatable code if memory location is not known at compile time Execution time : Binding delayed until run time if the process can be moved during its execution from one memory segment to another. Need hardware support for address maps (e.g., base and limit registers ). Address binding of instructions and data to memory addresses can happen at three different stages
Background image of page 4
8.5 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Multistep Processing of a User Program Multistep Processing of a User Program
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8.6 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Logical vs. Physical Address Space Logical vs. Physical Address Space The concept of a logical address space that is bound to a separate physical address space is central to proper memory management Logical address – generated by the CPU; also referred to as virtual address Physical address – address seen by the memory unit Logical and physical addresses are the same in compile-time and load-time address-binding schemes; logical (virtual) and physical addresses differ in execution-time address-binding scheme
Background image of page 6
8.7 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Memory-Management Unit ( Memory-Management Unit ( MMU MMU ) ) Hardware device that maps virtual to physical address In MMU scheme, the value in the relocation register is added to every address generated by a user process at the time it is sent to memory The user program deals with logical addresses; it never sees the real physical addresses
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8.8 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Dynamic relocation using a relocation register Dynamic relocation using a relocation register
Background image of page 8
8.9 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts Dynamic Loading Dynamic Loading Routine is not loaded until it is called Better memory-space utilization; unused routine is never loaded Useful when large amounts of code are needed to handle infrequently occurring cases No special support from the operating system is required implemented through program design
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8.10
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/21/2012 for the course COMPUTER CSCI 593 taught by Professor Hamnes during the Spring '11 term at Aston University.

Page1 / 56

ch08 - Chapter 8: Memory Management Chapter Chapter 8:...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online