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Administrative Information


Fabián E. Bustamante
Technological Institute, L465
+1 847 491-2745
Office Hours: By appointment


Mario A. Sánchez
Ford Design Building, 2-217
+1 847 467-3250
Office Hours: Tuesdays 3:00-4:00PM (Ford 2-217)
Wednesdays 4:30PM Wilkinson Lab (Ted)

Final Exam

Monday Dec. 5, 9-11AM

Course Description

Catalog Description: Fundamental overview of operating systems. Operating systems structures, processes, process synchronization, deadlocks, CPU scheduling, and memory management.

Detailed Description: Operating systems control all of a computer's resources and present users with the equivalent of virtual machines that are easier to program than their underlying hardware. This course provides an overview of fundamental operating system principles, complemented with discussions of concrete modern systems to help you understand how these principles are applied in real OSs. Topics covered include an overview of the components of an operating system, mutual exclusion and synchronization, implementation of processes, scheduling algorithms, memory management and file systems.

Although the main learning objective of the course is to understand the requirements, design and implementation of modern operating systems, at a higher level the course aims to provide you with a good grasp of basic abstractions employed in system-level software (such as processes, threads, virtual memory, caching, etc.), while uncovering the ``magic'' that happens inside the box.

The course has a strong project component intended to provide essential experience in designing and implementing complex systems and working as part of a team. In designing the projects and estimating their required effort/hours, I am assuming you are (1) familiar with basic computer organization and data structures and (2) capable of programming in C in UNIX (or UNIX-like) systems (experience with pointers, explicit dynamic memory allocation, multi-file projects, etc.).

Location and Time

In compliance with Section 504 of the 1973 Rehabilitation Act and the Americans with Disabilities Act, Northwestern University is committed to providing equal access to all programming. Students with disabilities seeking accommodations are encouraged to contact the office of Services for Students with Disabilities (SSD) at +1 847 467-5530 or SSD is located in the basement of Scott Hall. Additionally, I am available to discuss disability-related needs during office hours or by appointment.

Course Prerequisites

Communication Channels

There are a number of communication channels set up for this class:



Reference Material

Reading List

A set of papers providing a deeper historical perspective of operating systems, in-depth treatment of some of the topics I can only briefly cover in class, and some useful practical advice in designing and implementing complex systems.

When reading papers it is normally useful to write down a summary of about a page. Your summary should include at least:

  1. Paper title and its author(s).
  2. Brief one-line summary.
  3. A paragraph of the most important ideas: perhaps a combination of their motivations, observations, interesting parts of the design, or clever parts of their implementation.
  4. A paragraph of the largest flaws; maybe an experiment was poorly designed or the main idea had a narrow scope or applicability. Being able to assess weaknesses as well as strengths is an important skill for this course and beyond.
  5. A last paragraph where you state the relevance of the ideas today, potential future research suggested by the article, etc.

You may find the following brochure useful: Efficient reading of papers in Science and Technology by Michael J. Hanson, 1990, revised 2000 Dylan McNamee.

  1. The UNIX time-sharing system, Dennis M. Ritchie and Ken Thompson, Communications of the ACM, 17(7):365-375, July 1974.Unix
  2. Scheduler Activations: Effective Kernel Support for the User-Level Management of Parallelism, Thomas E. Anderson, Brian N. Bershad, Edward D. Lazowska and Henry M. Levy, ACM Transactions on Computer Systems, 10(1):53-79, February 1992.Process Management
  3. Experiences with Processes and Monitors in Mesa, Butler W. Lampson and David D. Redell, Communications of the ACM, 23(2):105-117, February 1980.Process Synchronization
  4. The Working Set Model for Program Behavior, Peter J. Denning, Proc. of the First ACM Symposium on Operating Systems Principles, October 1967.Memory Management
  5. A Fast File System for Unix, Marshall K. Mckusick, William N. Joy, Samuel J. Leffler and Robert S. Fabry, ACM Transactions on Computer Systems, 2(3):181-197, August 1984.File Systems
  6. Time, Clocks, and the Ordering of Events in a Distributed System, Leslie Lamport, Communications of the ACM, 21(7):558-565, July 1978.Distributed Systems
  7. The Multikernel: A new OS architecture for scalable multicore systems, A. Baumann, P. Barham, P-E Dagand, T. Harris, R. Isaacs, S. Peter, T. Roscoe, A. Schüpbach and A. Singhania, Proc. of SOSP, October 2009.
    This is a must read. We will discuss this paper in our last day of classes.

Potentially useful links and tools

Here is a list of potentially useful links:

Course Organization

The course is organized as a series of lectures, TA sessions, reading, homework, projects and exams:


There will be two kinds of homework assignments given throughout the class: reading assignments and textbook-style questions. You should have finished the assigned reading before coming to lecture. In addition, there will be a set of written homework assignments that must be done alone and turned in by midnight on the due date (see course policies below).

Homework Out In Solution
1: Introduction to Operating Systems [life.tar.gz] 09/22 09/29 Sol.
2: Processes, Threads and Synchronization 10/12 10/21 Sol.
3: Memory Management and Virtual Memory 10/31 11/10 Sol.
4: I/O and File Systems 11/16 11/23 Sol.
5: Research in Operating Systems 11/30 11/30 -

To submit your homework solutions (ASCII text only!) use the following page: SUBMISSIONS.


As you can deduce from the allocation of weights for grading, programming projects make up a major portion of this class. There will be three (3) projects. All projects are to be done by teams of two (2) people. Both partners should work cooperatively on the design, implementation, and testing of their solution.

For advanced undergraduates and graduate students - this year you will also have the chance to propose your own project for the quarter. If you are interested in this, please contact me the first day of class.

The following table of deadlines should serve you as a guideline for planning your quarter. Note that the first project has two deadlines, the first one just a week after the project is assigned. After that, you are given about two weeks per project. This should be plenty of time if managed carefully. Keep in mind that projects cannot be handed in more than three days late (check the course late policy for details).

You can get a copy of the handout and skeleton for any of your projects here. The skeleton for any project would be available in the format blah.tar.gz. You should save (transfer) this file to your Unix box and run % gunzip blah.tar.gz and % tar xvf blah.tar, in that order. This will create a skeleton directory that will include the source code and makefile for the skeleton as well as the associated regression testing framework.

Info on the EECS Wilkinson and T labs.

To submit your projects use the following page: SUBMISSIONS.

Project Out In Grade News
1: Tiny shell Part 1 [skeleton] 09/26 10/04 10/10 -
2: Tiny shell Part 2 [skeleton] 10/10 10/19 10/24 -
3: KMA [skeleton] [reading] 10/31 11/09 11/14 New submission deadline: 11/11
4: Simple File System [skeleton] 11/14 11/22 11/28 New submission deadline: 11/28


There will be a midterm and a final exam. Exams will be in-class, closed-book (except for one page of notes you are allowed to bring in), and will cover materials from lecture, required readings and projects. The final exam will not be cumulative.

Final exam sample.

Midterm sample.

Midterm solution.


I use a criterion-referenced method to assign your grade; in other words, your grade will be based on how well you do relative to predetermined performance levels, instead of in comparison with the rest of the class. Thus, if a test has 100 possible points, anyone with a score of 90 or greater will get an A, those with scores of 80 or greater will get a B, those with scores of 70 or greater will get a C, and so on. Notice that this means that if everyone works hard and gets >90, everyone gets an A.

Total scores (between 0 and 100) will be determined, roughly, as follows:

A note about class participation: while not explicitly included as an item in the previous list, your participation in class will be taken into consideration throughout the quarter and when granting partial and final scores/grades.

To check your grades you can use this form.

Course Outline and Approximate Dates

Because one has to be an optimist to begin an ambitious project, it is not surprising that underestimation of completion time is the norm.
-- Fernando J. Corbató, ``On Building Systems that Will Fail'', 1990 Turing Award Lecture.

Here's a link to the online calendar for the course, including lectures, assignments, exams, etc.

09/21 Introduction 1
09/26 Architectural Support for Operating Systems 2
09/28 Operating System Concepts & Structure 2; Paper 1
10/03 Processes 3 (3.6 excluded)
10/05 Threads 4
10/10 Scheduling 5; Paper 2
10/12 Process Synchronization 6
10/17 Semaphores & Monitors 6; Paper 3
10/19 Deadlocks 7
10/24 Midterm -
10/31 Memory Management 8
11/02 Virtual Memory 9
11/07 Virtual Memory 9; Paper 4
11/09 I/O & Secondary Storage 12 (12.8-9 excluded) and 13 (13.6 excluded)
11/14 File Systems 10
11/16 File Systems 10; Paper 5
11/21 Distributed File Systems 16, 17
11/23 Thanksgiving -
11/28 Distributed systems 16 & 17; Paper 6
11/30 Research in Operating Systems/Review for final MUST READ: Paper 7
12/05 Final -


Late policy:

Unless otherwise indicated, homework assignments and projects are due by midnight on their due date. If you hand in an assignment late, we will take off 10% for each day (or portion thereof) it is late. Assignments that are three or more days late receive no credit.

Cheating vs. Collaboration:

Collaboration is a really good thing and we encourage it. On the other hand, cheating is considered a very serious offense. When in doubt, remember that it's OK to meet with colleagues, study for exams together, and discuss assignments with them. However, what you turn in must be your own (or for group projects, your group's own) work. Copying code, solution sets, etc. from other people or any other sources is strictly prohibited.

Last modified: Thu Nov 24 14:21:01 CST 2011