CSE 451: Operating Systems

CSE 451: Operating Systems

Course Overview

CSE 451 is an undergraduate course on operating systems. During the course you will complete several labs, working in teams of two. Each lab will add a new feature to a primitive operating system called xk. At the end of this class you will be able to find your way around the source code of most operating systems, and more generally, be comfortable with systems software.

Lecture and Sections

Lectures are M/W/F from 11:30 - 12:20 in CSE2 G01

We have set up the class for Panopto lecture capture. However, we encourage you to attend lecture in person, if at all possible.

Section Meetings

Section Time Building Room TAs
AA 11:30 AM ECE 037 Soham & Ted
AB 12:30 PM ECE 045 Jai & Mahir & Sagar
AC 1:30 PM MGH 251 Jonathan & Andrew

Sections will not be recorded so we heavily encourage attending section since they are heavily tied to the labs.

Resources and Communications

Communication

  • The best way to get in touch with us is by making a private message board thread above.
    • Emails directly to the instructor will generally take longer to get a reply than through a message board thread
  • For fully anonymous communication, use our Anonymous Feedback

Course Staff

Instructor

  • Naomi Alterman (naomila[at]uw.edu)

TAs

  • Jonathan Trinh [Head] (jtrinh13[at]cs.washington.edu)
  • Soham Raut (sohamr[at]cs.washington.edu)
  • Mahir Emran (memran[at]cs.washington.edu)
  • Ted Guan (tedguan[at]cs.washington.edu)
  • Jai Rungrachakanont (thakrit[at]cs.washington.edu)
  • Sagar Saby (sssaby[at]cs.washington.edu)
  • Andrew Wood (arxzwood[at]cs.washington.edu)

Assignments

There are five kinds of assignments in this class:

  • Labs. Labs are significant programming projects done in pairs. Labs extend a basic OS kernel (derived from xv6) to support protected system calls, multiprocessing, paged virtual memory, and crash-resilient file systems. Labs are autograded and require correctness in all cases.

  • Lab questions. Each lab includes short-answer questions submitted on Gradescope, covering topics related to the implementation. These are submitted separately from the lab and include a brief post-mortem.

  • Problem Sets. Problem sets help you think through topics covered in lecture and labs. You will have at least one week to complete each problem set, and they are completed individually unless otherwise noted.

  • Design documents. Labs 2-4 require a design document prepared and submitted jointly with your lab partner. These are due one week before each lab so that we can provide timely feedback and may be revised for W credit. The documents must be relevant to the content covered in the course.

  • Exams. There will be two in-person exams for this class

    • Midterm: November 6, 11:30 - 12:20 in CSE2 G01
    • Final: December 16, 2:30 - 4:20 in CSE2 G01

Grade Distribution

We reserve the right to adjust the percentages as needed.

  • 40% Labs/Lab Questions
  • 15% Problem Sets
  • 5% Design Docs
  • 15% Midterm
  • 25% Final

You must take both exams in order to receive a passing grade for this class.

W Credit

W credit is optional and requires revised design documents for labs 2-4, incorporating staff feedback.

Partners

Labs are designed for pair work and require active collaboration.

Do not split the design work. Pair program during design.

Partners are expected to:

  • Communicate frequently
  • Work synchronously on design
  • Inform each other of availability

If you feel the distribution of work between you and your partner is grossly unfair:

  1. Talk to them.
    If this does not help,
  2. Contact the course staff through the message board. We will set up a mediation meeting between you, your partner and a TA to make a work plan.
    If this does not help,
  3. Contact the course staff through the message board again. At staff discretion, your partner's lab grade may be penalized.

Class Policies

Late Work

  • Labs: 24-hour grace period, then -1% per day
  • Problem sets: 24-hour grace period, then -1% per day
  • Design documents: no grace period
  • Design doc revisions: 24-hour grace period, then -1% per day

There is no cap on total grace usage.

Academic Honesty

Read the CSE Academic Misconduct Policy and the class's AI use policy.

Do not:

  • Share code or written solutions
  • Use others' solutions

High-level discussion among your peers is allowed and encouraged!

AI

The icon for the Allen School's 'AI as a Reference Tool' policy, showing a magnifying glass over a stack of paper. In the magnifying glass we see a computer chip labelled 'AI.' This class follows the Allen School's AI as a Reference Tool policy.

We adopt this policy because it is not possible to fairly enforce a blanket "no AI" policy. That said, we strongly recommend you NOT use AI as a reference tool, as it can get important details wrong and, more than likely, you are not yet in a position to judge its accuracy on this subject.

Instead of using AI tools, please consider posting to the message board, talking to your peers, or using the content on our resources page.

Disability Resources

The Disability Resources for Students (DRS) is a unit within the Division of Student Life and is dedicated to ensuring access and inclusion for all students with disabilities on the Seattle campus. They offer a wide range of services for students with disabilities that are individually designed and remove the need to reveal sensitive medical information to the course staff. If you have a medical need for extensions of exam times or assignment deadlines, these will only be granted through official documentation from DRS. Browse to the DRS application process page to start the process as soon as possible to avoid delays.

You can refer to the university policies regarding Disability Accommodations for more information.

Religious Accomodations

Washington state law requires that UW develop a policy for accommodation of student absences or significant hardship due to reasons of faith or conscience, or for organized religious activities. The UW's policy, including more information about how to request an accommodation, is available at Religious Accommodations Policy. Accommodations must be requested within the first two weeks of this course using the Religious Accommodations Request form.

Extenuating Circumstances

Given extenuating circumstances, the instructor may grant a policy exception on a case-by-case basis. A policy exception is one of the following:

  • Waiving the late work penalty
  • Rescheduling an exam date

In the vast majority of cases, extensions will not be granted.

The following is a non-exhaustive list of reasons that do not give cause for an exception:

  • Getting sick, unless you were literally hospitalized

    • There is no reasonable way to judge how sick is “sick enough” for an exception. We don’t want to put you in the position of begging for points, and we don’t want to put course staff in the position of having their hearts twisted trying to decide what to do. If you become unpredictably ill, turn in whatever partial work you’re able to complete and do your best on the remaining assignments. No partial grade is going to make or break your GPA.
    • The one exception is chronic illness, assuming that you talk with the instructor at the beginning of the quarter about it. See below for more.

  • Computer trouble or network outages

    • Computers break. Websites go down. Shared servers like Attu get slow when lots of people use them at once. These challenges are predictable enough. Submitting your work close to the due date means you accept the risk that one of these obstacles may cause your work to incur a late penalty.
    • If your computer or internet access regularly interferes with your ability to do assigned work, we want to help you. Please reach out to both your undergrad advisor and the instructor so we can discuss workarounds. Note that this is still not a cause for policy exceptions.
    • If a technical issue prevents the majority of your classmates from submitting their work by the due date, a class-wide exception may be considered by the course staff.

  • Career-related engagements like work schedules, conference travel, job interviews or startup meetings

    • For homework assignments, these things are predictable and you can plan ahead knowing how they might affect you.
    • For exams, we will hold them either during class or at a registrar-scheduled exam time. You are expected to be available during these times. If you cannot be, you should not take this class.

  • Earnestly having a tough quarter

    • We sympathize and would love to support you in other ways, but policy exceptions are not one of them.

Beyond this, the instructor will grant exceptions on a case-by-case basis given enough prior notice. Email the instructor to discuss your situation. Just requesting an exception does not grant it – the instructor must confirm, and so giving yourself as much lead time as possible is helpful here.

If notified within the first week of the quarter and with your undergrad advisor cc’ed on the email, the following are potentially valid reasons for exceptions:

  • Scheduled family-related engagements like birthdays, weddings or graduations
  • Religious observances and holidays
  • Chronic illness – that is, something about the way your body or mind works that interferes with your ability to turn work in on time

If notified more than 24 hours before the due date and with your undergrad advisor cc’ed on the email, the following are potentially valid reasons for exceptions:

  • Death or sudden need for support of a family member
  • Legal appointments or court dates (immigration issues, family law, etc)
  • Housing insecurity (facing eviction, issues with short-term housing, etc)

The instructor will not grant exceptions requested within 24 hours of the assignment due date or exam date, unless your situation is a life-altering crisis. If illness or other circumstances prevented you from notifying the instructor in advance, and this has sufficiently affected your grade, your best option is discussing the situation with your undergraduate advisor and having them reach out to the instructor.