CSE 120: Principles of Computer Operating Systems

Spring 2023

Instructor

Amy Ousterhout (aousterhout@ucsd.edu)
Office Hour: Fri 2–3pm (CSE 3130)

Lectures

Tu/Th 3:30–4:50pm in Franklin Antonio Hall 1450

TAs and Tutors

Charlotte Tang	Yunxiang Chi
Kaiyuan Wang	Yuke Liu
Fengyuan Wu	Xiyan Shao
Steven Wu

Discussion Section

Fri 4–4:50pm in Center Hall 214

TA/Tutor Lab Hours

Calendar (CSE Basement)

Discussion Board

Piazza

Announcements and Grading

Canvas

Textbook

Remzi H. Arpaci-Dusseau and Andrea C. Arpaci-Dusseau
Operating Systems: Three Easy Pieces
Version 1.00 (Available free online!)

Course Objectives

This course covers the principles of operating systems. It emphasizes the basic concepts of OS kernel organization and structure, processes and threads, concurrency and synchronization, memory management, file systems, and communication. It is also a project course, providing essential experience in programming with concurrency, implementing and unmasking abstractions, working within an existing complex system, and collaborating with other students in a group effort.

Course Schedule

The following table outlines the schedule for the course. We will update it as the quarter progresses.

The optional readings include primary sources and in-depth supplements for concepts in the class. Supplemental reading is for your own interest — the readings are not required, nor will you be tested on the material. Note that some of the links to the documents point to the ACM Digital Library. UCSD has a subscription to the ACM Digital Library, so you can access these links from a web browser on campus.

Date	Lecture	Readings	Optional Readings	Homework	Project
Tu 4/4	Course Intro	CH. 1, CH. 2	The UNIX Time-Sharing System	HW 1: Out	PR 0: Out
Th 4/6	Interactions with Apps and Hardware	CH. 6	Linux context switch A Case Against (Most) Context Switches
Tu 4/11	Processes	CH. 3, CH. 4, CH. 5	A fork() in the road		PR 0: Due PR 1: Out
Th 4/13	Threads	CH. 26, CH. 27	Illustrated Tales of Go Runtime Scheduler C++ Coroutine Tutorial
Tu 4/18	Synchronization	CH. 28, CH. 29	RCU Usage In the Linux Kernel: One Decade Later	HW 1: Due HW 2: Out
Th 4/20	Semaphores	CH. 31	The Structure of the 'THE'-Multiprogramming System
Tu 4/25	Condition Variables and Deadlock	CH. 30, CH. 32	Understanding Real-World Concurrency Bugs in Go
Th 4/27	CPU Scheduling	CH. 7, CH. 8	Lottery Scheduling: Flexible Proportional-Share Resource Management Shenango: Achieving High CPU Efficiency for Latency-sensitive Datacenter Workloads		PR 2: Out
Tu 5/2	Midterm Review			HW 2: Due HW 3: Out	PR 1: Due
Th 5/4	Midterm Exam
Tu 5/9	Memory Management Overview	CH. 15, CH. 16	A Study of Virtual Memory Usage and Implications for Large Memory
Th 5/11	Paging	CH. 18, CH. 19, CH. 20	Mitosis: Transparently Self-Replicating Page-Tables for Large-Memory Machines
Tu 5/16	TLBs, Swapping	CH. 21	Coordinated and Efficient Huge Page Management with Ingens		PR 3: Out
Th 5/18	Page Replacement and Memory Allocation	CH. 17, CH. 22	Learning-based Memory Allocation for C++ Server Workloads
Fri 5/19	n/a				PR 2: Due
Tu 5/23	Storage Devices and File System API	CH. 37, CH. 39	A case for redundant arrays of inexpensive disks (RAID)	HW 3: Due HW 4: Out
Th 5/25	File System Disk Layout	CH. 40	The Google File System
Tu 5/30	File Caching and Reliability	CH. 41, CH. 42	IRON File Systems
Th 6/1	Virtual Machines	Appendix B	Virtual Machine Monitors: Current Technology and Future Trends
Tu 6/6	Protection	CH. 53, CH. 55	RedLeaf: Isolation and Communication in a Safe Operating System	HW 4: Due
Th 6/8	Final Review
Sat 6/10	n/a				PR 3: Due
M 6/12	Final Exam, 3-6 pm

Thanks to Geoff Voelker, Yiying Zhang, John Ousterhout, and the faculty who teach COS 318 at Princeton whose slides and notes heavily inspired the slides above.

Course Organization

The course is organized as a series of lectures by the instructor, discussion sections by the TAs, reading, homework, and project assignments, and exams:

Lectures: The lectures present the core of the material.
Sections: The discussion sections are given by the TAs to answer questions about the lecture, textbook readings, homework assignments, and project assignments.
Readings: The readings in the textbook provide preparation and a reference for the lectures. Note, however, that they are not a substitute for the lectures.
Homeworks: There are four homework assignments with questions taken from the textbook and other materials. The homework assignments reinforce the readings and lectures.
Projects: There are three programming projects, all using the Nachos instructional operating system.
Exams: There are two exams, a midterm exam in the middle of the quarter and a final exam at the end of the quarter. The exams will cover the material presented in lecture, the homeworks, and the projects.

Homeworks

The course will have four homeworks, and I will post them as the quarter progresses. You will submit all your homework electronically via Canvas. We will reduce homework grades by 20% for each day that they are late.

Due to extensive copying on homeworks in the past, we have changed how homeworks are graded. As long as you submit a technical answer related to the question, you will get full credit for the question. The goal of the homeworks is to give you practice learning the material. The homework questions both supplement and complement the material from lecture and in the project, and you will also find the homework questions to be useful for practicing for the exams. We will post solutions to all homeworks after they are submitted, and you can use them for studying as well. But, even with the solutions, the amount you learn from the homeworks will be directly correlated with your effort working on them.

I encourage you to collaborate on the homeworks: you can learn a lot from your fellow students. Collaboration consists of discussing problems with other students and independently writing your own answers to the problems based upon those discussions. As a rule of thumb, you should be able to discuss a homework problem in the hall with others, go home, and then write up your answer to the problem on your own.

Projects

The course has one tutorial project and three programming projects using the Nachos instructional operating system.

Project page

Exams

The course has two exams: a midterm and a final. The midterm will cover the first half of the class, and the final will focus on the second half of the class.

Sample Midterm from a previous year [Solutions]
Sample Final from a previous year [Solutions]

Discussion Sections

Discussion sections answer questions about the lectures, homeworks, projects, and programming environment. They may also supplement the lectures with additional material.

Grading

Your grade for the course will be based on your performance on the homeworks, midterm exam, final exam, and projects, as follows:

Homeworks: 6%
Midterm: 22%
Final: 28%
Projects: 44%

The academic honesty guidelines outlined by Charles Elkan apply to this course. I urge you to resist any temptation to cheat, no matter how desperate the situation may seem. If you are in circumstances that you feel compel you to cheat, come to me first before you do so.