News

• Exams and Quizzes
• Quiz 6 solution
• Quiz 5 solution
• Quiz 4 solution
• [Oct 26] Quiz 3 grades posted. Less than 17 is definitely D or F.
  Quiz 3 solution
  
• [Oct 20] Added Concurrency slides (link in Notes/text section).
• [Oct 20] Updated "Locks from RW-atomicity" slides.
• [Oct 17] Added "Locks from RW-atomicity" slides (link in Notes/text section).
• [Oct 14] Added Queueing slides (link in Notes/text section).
• [Oct 11] Quiz 2 grades posted. C- is around 23; less than 20 is definitely D or F.
  Quiz 2 solution
  
• [Sep 30] Quiz 1 grades posted.
  Quiz 1 solution
• [Sep 17] Added OS Process slides and Deadlocks (links in Notes/text section).
  Previously added updated GeekOS overview, ToyOS slides, and Course overview slides.
• [Sep 6] GeekOS Installing Geekos.
• [Sep 1] We will be using Piazza. Sign up with your name: https://piazza.com/umd/fall2013/cmsc412
• [Aug 28] The class size will increase only if the TA support increases. (Currently, there is only 1 TA.)

Overview

This course is a hands-on introduction to operating systems, including topics in: multiprogramming, communication and synchronization, memory management, IO subsystems, and resource scheduling polices. The objective is an in-depth understanding of how an operating system manages resources in a computer and provides programmers with a machine and device independent interface. The classes emphasize concepts.

There is a significant and time-consuming programming project (GeekOS). You are provided with the source code (about 3000 lines of C and some assembly) of a "Unix-style" skeleton operating system for a PC-like x86 platform. You have to understand a large part of this code and augment it with various OS functionality: interprocess signals, semaphores, cpu scheduling, memory paging, file system, etc. The programming environment is Gnu/Linux. The x86 platform is simulated by QEMU. You can use the linuxlab cluster, but you will probably want to run the environment on your own machine.

Schedule of projects (P0-P5) and quizzes (Q1-Q6)

Project due dates are tentative (to be fixed when project is posted).
Tell me soon if a quiz date is problematic.



Sun Mon Tue Wed Thu Fri Sat SEP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 P0 19 20 21 22 23 24 Q1 25 26 27 28 29 30 P1 1 2 3 4 5 OCT 6 7 8 Q2 9 10 11 P2 12 13 14 15 16 17 18 19 20 21 22 Q3 23 24 25 P3 26 27 28 29 30 31 1 2 NOV 3 4 5 6 7 8 9 10 11 W 12 Q4 13 14 15 P4 16 17 18 19 20 21 22 23 24 25 26 Q5 27 28 tbrk 29 30 1 2 3 4 5 6 7 DEC 8 9 10 Q6 11 12 13 P5 14 15 16 17 18 19 Final 20 21 22 23 24 25 26 27 28 29 30 31

Topics in general

• Introduction to operating systems
• Overview of GeekOS
• Processes/threads: implementation, protection, scheduling
• Concurrent processes: reasoning, synchronization, communication
• Deadlocks: prevention, avoidance, detection
• Memory management
• File systems: interface, implementation
• I/O systems (disks, etc.)
• Other topics (e.g, security, networking, etc.)

Topics in detail

Notes/text

• Operating System Concepts, 6th edition or later, Siberschatz, Galvin and Gagne, Wiley. (required)
  Gentle and fluffy ... No need for very recent version. Editions 6 and some later ones are inexpensive (free?).
• Operating Systems: Principles and Practice, Thomas Anderson, Michael Dahlin. (not required)
  I've looked at a beta version. It's concrete and detailed, but perhaps not gentle.
• Course overview slides
• ToyOS slides
• GeekOS overview
• OS Process slides
• Queueing slides
  • For more on queueing, see here (not required)
• "Locks from read-write atomicity" slides
• Memory management slides
• Concurrent program slides
• Filesystem slides
• Deadlocks slides

Grading

• Your letter grade is based (non-linearly: see below) on the following:
  • About 5 or 6 short (eg, half-hour) exams: approx 30% (Dates: see schedule above)
  • Final: approx 20% (Thu Dec 19 10:30-12:30)
  • Project: approx 45%
  • Class participation: approx 5%
  "Approx" means +/− 5% (eg, projects become 50% and class particpation becomes 0%).
• You will get a letter grade for project and a letter grade for the rest. If you get D or F in either, then that is your course grade. If you get C or higher in both, then your course grade will be determined by both (as per the above weights).
• Skip-final option: You can skip the final (i.e., don't show up), and have its score set to your quiz average. (More details later.)

Missed exams and submissions

• Each project has a regular deadline and one or two late deadlines, which will be fixed soon after the project is assigned. Quiz dates will be fixed at least two weeks in advance.
• No submissions after the last late deadline (barring medical/family emergency).
• If you miss an exam or project deadline due to medical or family emergency, please see me. If it's due to illness, please bring documentation signed by a health care professional.
• If you miss one quiz, its weight will be moved to the others.

Regrades

Any regrade request must be submitted within a week of the project grade being posted or the exam being returned.

Projects are to be done individually. Do not show others your source code. Do not look at another's source code. You can discuss your program with others. You can jointly examine the unmodified GeekOS distribution source code.

Academic dishonesty.