Operating Systems

1. Operating Systems Vivek Pai Lecture 1 Sep 12, 2002

2. Who I am Vivek Pai PhD 99/00, Rice Research: OS, networking, high-performance apps Why I do this Fun Interesting Design opportunities “Profitable” Introduction COS 318 - Operating Systems, Vivek Pai

3. Principles OS design Some theory Rationale Practice Not trade school Goals Understand OS decisions Basis for future learning Get hands dirty Not “elite hacker” About this course… COS 318 - Operating Systems, Vivek Pai

4. Fast pace Lots of projects (programming) Hard material Course changing based on feedback Not the end of the world – course favorably received last year, under much more trying circumstances Expect (Some) Pain COS 318 - Operating Systems, Vivek Pai

5. Works Solid C background Flexible approach Grasping Prereqs Open mind Einstein Feedback sheets Doesn’t Schedule overload Missing background Mathematical precision What Works & Doesn’t COS 318 - Operating Systems, Vivek Pai

6. Why So Many Grades? • Programming projects • Midterm & final exams • Quizzes (see me about health/school absences) Intended to reduce pressure/anxiety More data points = less noise Somewhat generous extra credit COS 318 - Operating Systems, Vivek Pai

7. Grades based on mean/deviation People have done generally well in the past 25 / 38 As 17 / 11 Bs 4 / 7 Cs Honor System Use common sense Ask for clarification Cooperation OK Work is your own (pairs for labs) Some Relief COS 318 - Operating Systems, Vivek Pai

8. This Is Engineering Tradeoffs Constraints Optimizations Imperfection Nothing’s Permanent High rate of change Lots of inertia Cost/benefit analyses Human error There Is No Magic COS 318 - Operating Systems, Vivek Pai

9. My home page Course home page Newsgroup Precepts Design reviews Mechanics – Info COS 318 - Operating Systems, Vivek Pai

10. Assigned readings 20% quizzes 20% midterm 20% final 40% projects – some extra credit Late policy: 6 hours: 91% 12 hours: 84% 24 hours: 71% 48 hours: 50% Mechanics – Grading COS 318 - Operating Systems, Vivek Pai

11. Mechanics - People • See web site – it’s up to date! • Basically • Me – quizzes, exams • TAs – precepts, labs • Office hours – T, W, Th or by Appt COS 318 - Operating Systems, Vivek Pai

12. Modern Operating Systems Tannenbaum Different from last time Available at Ustore Various readings – will be available from my home page (course web site) Mechanics – Readings COS 318 - Operating Systems, Vivek Pai

13. 6 projects, 2 themes Build parts of a mini-OS Write applications that interact with OS 2 weeks each Uses Linux, sort of Partners – be decent to each other Option – one big project – only for the brave Mechanics - Projects COS 318 - Operating Systems, Vivek Pai

14. Name Year Major E-mail address Phone # Picture via URL Why you’re taking the class What you’d like/hope to learn Send Me Your Details COS 318 - Operating Systems, Vivek Pai

15. What Is an OS? COS 318 - Operating Systems, Vivek Pai

16. “Code” that: Sits between programs & hardware Sits between different programs Sits betweens different users But what does it do? What Is an OS? COS 318 - Operating Systems, Vivek Pai

17. Resources Allocation Protection Reclamation Virtualization Services Abstraction Simplification Convenience Standardization What Is an OS? Makes computers simpler COS 318 - Operating Systems, Vivek Pai

18. Resources Allocation Protection Reclamation Virtualization Finite resources Competing demands Examples: CPU Memory Disk Network What Is an OS? COS 318 - Operating Systems, Vivek Pai

19. Resources Allocation Protection Reclamation Virtualization You can’t hurt me I can’t hurt you Implies some degree of safety & security What Is an OS? COS 318 - Operating Systems, Vivek Pai

20. Resources Allocation Protection Reclamation Virtualization The OS giveth The OS taketh away Voluntary at run time Implied at termination Involuntary Cooperative What Is an OS? COS 318 - Operating Systems, Vivek Pai

21. Resources Allocation Protection Reclamation Virtualization Illusion of infinite, private resources Memory versus disk Timeshared CPU More extreme cases possible (& exist) What Is an OS? COS 318 - Operating Systems, Vivek Pai

22. Mechanism – tool to achieve some effect Policy – decisions on how to use tool Examples: All users treated equally All program instances treated equally Preferred users treated better No deterministic behavior at all Mechanism & Policy COS 318 - Operating Systems, Vivek Pai

23. Is There a Perfect OS? COS 318 - Operating Systems, Vivek Pai

24. Portability Security Fairness Robustness Efficiency Interfaces Is Any OS Complete? COS 318 - Operating Systems, Vivek Pai

25. 60’s-70’s - Mainframes Rise of IBM 70’s - 80’s – Minicomputers Rise of Digital Equipment 80’s - 90’s – PCs Rise of Intel, Microsoft Now – Post-PC Distributed applications History Lessons COS 318 - Operating Systems, Vivek Pai

26. Historical Comparison COS 318 - Operating Systems, Vivek Pai

27. Constant Employment? • New hardware • New features • New approaches Examples: Palm, Java, WWW COS 318 - Operating Systems, Vivek Pai

28. May You Live in Interesting Times… • Processors double in 18 months • Disk doubling every 12 months • Global bandwidth every 6 months • “Sweet spot” constantly decaying Do people ever double? COS 318 - Operating Systems, Vivek Pai

29. Name Year Major E-mail address Phone # Picture via URL Why you’re taking the class What you’d like/hope to learn Consider this a grade Send To vivek@cs… COS 318 - Operating Systems, Vivek Pai

30. And Now For Something Completely Different… COS 318 - Operating Systems, Vivek Pai