CS 656: Operating Systems

Spring, 2008

Professor: Marty Humphrey

Latest News/Revisions to Web Page (Fri 5/2/08)

• Added study guide for Final exam (Added 5/2/08)
• Added papers for Day 3 of the mini-symposium (Added 4/28/08)
• Added papers for Day 2 of the mini-symposium (Added 4/22/08)
• Added papers for Day 1 of the mini-symposium (Added 4/21/08)
• Added class notes for Wed 4/9, Mon 4/14, and Wed 4/16 (Added 4/8/08)
• Added schedule for class mini-symposium (Added 4/16/08)
• Added class notes for Mon 4/7 (Added 4/8/08)
• Added class notes for Wed 4/2 (Added 4/2/08)

Logistics

• Instructor:            Marty Humphrey
• Office:                 Olsson 236C
• Email:                 humphrey at cs.virginia.edu
• Class meeting time:        Mon and Wed 2 - 3:15 in MEC 216
• My Office Hours:  Mon 1-2, Wed 11-2 or by appointment
• WWW:                http://www.cs.virginia.edu/~humphrey/cs656
• Prerequisites: Undergraduate course in OS; CS 654 or instructor permission.
• Textbook: Operating Systems Concepts, 7^th edition (ISBN 0-471-69466-5)

Silberschatz, Galvin, and Gagne

Description

An operating system facilitates the execution of user and system programs on the bare hardware of a machine. One view of an operating system is that it essentially manages resources such as physical memory, disks, and CPU(s) by providing the necessary capabilities to the user. By managing resources, the operating system allows (in most cases) multiple user programs to be executed concurrently, without corrupting each other.

This course covers the design and implementation of operating systems, stressing the interaction of the operating system with computer architecture, compilers, networks, and user programs. Covered topics include processes, CPU scheduling, process synchronization, deadlocks, memory management, virtual memory, file systems (interface and implementation), protection, security, and some aspects of distributed operating systems.

The general structure of this class is to cover the topics typically found in an undergraduate OS class at about 3 times the pace of an undergrad class. The rest time (the remaining 2/3, that is) will be used discussing research papers on the given topic – note that these papers will be some combination of “older” papers and “new” papers.

Specific course objectives:

1. Develop an understanding of the tasks and components of an operating system and how they influence the operation of user-level programs, how the computer architecture and programming languages interact with the OS to manage concurrent activities, and how the OS manages resources and provides protection and security.

2. Learn the principles of correct concurrent programming and how various types of synchronization primitives operate.

3. Develop an understanding of the fundamental concepts of computer security.

4. Be able to analyze how contemporary operating systems implement these concepts, be able to evaluate the advantages and disadvantages of their varying implementations, and be able to discuss these issues in a knowledgeable fashion.

5. Be able to analyze and discuss the pros/cons of particular OS implementation and evaluation strategies.

6. Be able to critically read systems-oriented research papers.

Details

• It is highly recommended, but not mandatory, that students attend every class.
• Assignments are due at the beginning of class on the day that the assignment is due. For each weekday that your assignment is late, 10% will be deducted. No assignment will be accepted later than three days after the due date.
• The course will be conducted according to the UVA honor system. Homeworks and exams are to be completed by the individual. I expect a signed honor pledge on all homework, quizzes, and exams; more importantly, I expect you to adhere to the intent of the pledge. Cooperative efforts at understanding the material and the assignments of the course are encouraged. For the programming projects, the algorithms and programs submitted by a group must be fully developed and written by the group submitting them. Each written homework must be developed and written only by the student submitting it.
• Unless otherwise specified, students are expected to understand the material in the book. I specifically do not go into great detail into topics that I believe are explained very well in the text.
• Do NOT wait until the last minute to do the programming assignments. In any software project, you must anticipate and plan for unexpected events (such as a machine crashing at an inopportune time).
• If you are having difficulty with a particular concept of the class, please let me know. If you aren't understanding something, there's a good chance that others in the class are confused as well.
• It is required (out of courtesy for your fellow classmates) that cell phones be turned off before entering class. This requirement is based on a resolution passed by the student council. Laptops are permitted in class but I retain the right to ask you to turn it off and put it away, particularly if (a) they’re being used for non-CS656 purposes or (b) they’re distracting other students.

Coursework

What	When	Weight
Readings (papers, textbook, etc.)	every class
Class participation	every class	10 %
Written synopses / programming assignment	Synopses: every class; Prog. Assign in 1^st half of class	25 %
Class project	2^nd half of class; presentation in last 2 weeks of class	35 %
Final exam	Fri, May 9, 2pm-5pm	30 %

Synopses (effective for the March 24 papers)

Each student must submit a synopsis of the papers for the day at least 4 hours prior to the beginning of class (so this usually means by 10am that day). The single email should contain at most 1 page (ASCII – no attachments) for each paper of the day (e.g., if we cover 2 papers that day, then the student should submit 1 email containing two synopses, where each synopsis is at most 1 page). The format of a synopsis must be:

· Paragraph 1: 1-2 sentence problem statement (what problem is being addressed in the paper?) and 1-2 summary of the paper (e.g., “the authors address the problem by designing and implementing…”)

· Paragraph 2: pros of the paper (what’s compelling/effective about the paper), and then cons of the paper (what are the most significant flaw(s) of the paper?)

The student will receive a single grade for the day’s synopsis/synopses. The grading is as follows:

· CP (“check-plus” – 100 points): all 4 parts are excellent, assertions/claims with evidence, synopsis shows excellent understanding and insight

· C (“check” – 75 points):

· CM (“check-minus” – 50 points): at most 2 of the 4 parts are satisfied

· Not submitted 4 hours prior to class time: 0 points

Old grading: All synopses submitted prior to the particular class receive CP otherwise 0

Programming Assignment (1^st half of Class)

There is one programming assignments planned for the first half of class, which everyone in the class will do (individually). It will be on basic measurement and interpretation of typical OS functionality, such as opening a file, creating a process, etc.

Class Project (2^nd half of Class)

The class project is very important (35% of your grade). It can be your own design/implementation, or you can pursue one of the topics that I provide. You will meet regularly with me to ensure your plan and that you are hitting your milestones. This will be completed by you or with one other person (NO 3-PERSON GROUPS ALLOWED!). You will write a short conference- or workshop-style paper, and you will give a presentation at the class mini-conference in the last two weeks of class. More details will be provided in class.

Schedule for project meetings:

	Thurs Mar 27	Fri Mar 28
9:00 – 9:30		Claire and Dan
9:30 – 10:00
10:00 – 10:30	Joel and Andrew
10:30 – 11:00		Jiakang and Jiayuan
11:00 – 11:30		Mike and Will
11:30 – noon		Qiang
Noon – 12:30		JD and Zhigeng
12:30 – 1:00		Yafeng and Jian
1:00 – 1:30
1:30 – 2:00	Colleen and Eric	Paul and Ming
2:00 – 2:30
2:30 – 3:00	Blake, Steven, Chris
3:00 – 3:30
3:30 – 4:00	Ke and Lukasz
4:00 – 4:30	Blake and Tim
4:30 – 5:00	Jason and Hengchang

Schedule

Date	Class #: Week #/Day #	Topic	Text Chapter	Assignment Out	Assignment Due
Wed 1/16	1: W1-1	Intro (class notes)
Mon 1/21		No class – Martin Luther King day
Wed 1/23	2: W2-1	Edsger W. Dijkstra The Structure of the "THE" Multiprogramming System (incl. appendix) Communications of the ACM 11(5), May 1968. Per Brinch Hansen The Nucleus of a Multiprogramming System Communications of the ACM 13(4), April 1970 (class notes)	1,2	Question for write-up: What are the main philosophical differences in design of the THE system, the Nucleus system, and HYDRA?
Mon 1/28	3: W3-1	W. Wulf, E. Cohen, W. Corwin, A. Jones, R. Levin, C. Pierson, and F. Pollack HYDRA: The Kernel of a Multiprocessor Operating System Communications of the ACM 17(6), June 1974, pp. 337-344. (class notes)
Wed 1/30	4: W3-2	David D. Redell, Yogen K. Dalal, Thomas R. Horsley, Hugh C. Lauer, William C. Lynch, Paul R. McJones, Hal G. Murray, and Stephen C. Purcell Pilot: An Operating System for a Personal Computer Communications of the ACM 23(2), Feb 1980. Hugh C. Lauer Observations on the development of an operating system ACM Symposium on Operating Systems Principles, 1981. (class notes)		No additional question
Mon 2/4	5: W4-1	No Class -- Marty out of town
Wed 2/6	6: W4-2	Dawson Engler and Franz Kaashoek. Exterminate All Operating Systems Abstractions. Proceedings of the Fifth Workshop on Hot Topics in Operating Systems (HotOS-V), 1995. Dawson Engler, Franz Kaashoek, J. O’Toole, Jr. Exokernel: an operating system architecture for application-level resource management. Fifteenth ACM Symposium on Operating Systems Principles, 1995. (class notes)		What are the similarities and differences in philosophy of Exokernel vs. Nucleus?
Fri 2/8: 4:15pm-5:30 (OLS 005)	Make-up 5: W4-1	Edouard Bugnion, Scott Devine, and Mendel Rosenblum. Disco: Running Commodity Operating Systems on Scalable Multiprocessors. Proceedings of The 16th ACM Symposium on Operating Systems Principles, October 1997 (class notes)		What are the similarities and differences of Exokernel and Disco?