1. An Overview of the Linux Operating System
Group Members:
Chad Dalton
Robert Grey
Jonathan Mencher
Andrew Serene
Greg Tumolo

2. Overview of Presentation:
History and General Description
Basic Features of the Early OS
Process Description and Management
Thread Description and Management
Memory Management
The File System

3. Linux History
Linux began as an effort by Linus Torvalis to replicate the minix operating system for free
Evolved into an open source project supported and developed by users across the internet
Ported to several processors including Alpha, Sun SPARC, Motorola, and the Apple PowerPC
Major companies have evolved distributions

4. Main Features of the OS Multi User, Multi Tasking OS
Process Oriented with Multi-Threading
Offers X Windows graphical interface
Extremely Internet Oriented

5. The Early Kernel and Basic Services
True Microkernel Architecture
Basic Kernel Services
Process and Thread Management
Module Loading
Initialization of OS
Basic OS Services
Command Prompt
Compiler
Access to Hardware
Virtual Memory
File System

6. Process Description and Management
Description of Processes
task_struct
Controls process table
Creates processes
Process Table Structure
2 links to previous and next
Process State
Running, Waiting, Stopped and Zombie
Process Security
Process has privileges of parent

7. Thread Description and Management
Description of Threads
First used in version
User Level
Less overhead
Cause starvation
Kernel Level
Require mode changes
Preferred in Linux
Allow for SMP in Linux
Thread Classification

8. Memory Management Paging scheme is utilized in Linux Block scheduling
Aging variable
mem_map_t and mm_struct
mem_map_t -> physical memory
mm_struct -> virtual memory

9. The File System Linux File System History EXT EXT2
VFS – Virtual File Syste
Supports many file systems including msdos, smb, iso9660, sysv, hpfs, etc.
Inode is a basic component
File systems are “mounted” in Linux
Possible to mount over existing directory
Original Structure is returned after “unmounting”