An Overview of the Linux Operating System Group
- Slides: 9
An Overview of the Linux Operating System Group Members: Chad Dalton Robert Grey Jonathan Mencher Andrew Serene Greg Tumolo
Overview of Presentation: 1. History and General Description 2. Basic Features of the Early OS 3. Process Description and Management 4. Thread Description and Management 5. Memory Management 6. The File System
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 Power. PC • Major companies have evolved distributions
Main Features of the OS • Multi User, Multi Tasking OS • Process Oriented with Multi-Threading • Offers X Windows graphical interface • Extremely Internet Oriented
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
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
Thread Description and Management • Description of Threads • First used in version 1. 3. 56 • User Level • Less overhead • Cause starvation • Kernel Level • Require mode changes • Preferred in Linux • Allow for SMP in Linux • Thread Classification
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
The File System • Linux File System History • EXT 2 • VFS – Virtual File Syste • Supports many file systems including msdos, smb, iso 9660, 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”