Click here to see a PREVIEW of important rules
that was posted before the summer session started.
This is an undergraduate course on computer operating systems.
(But only graduate students are permitted to be in this class.
USC undergraduate students must take CS 350 in order to get credit for OS.
If you are an undergraduate student, you cannnot be in this class
and you cannot get credit for Operating System if you take this class.
Please check with your adviser to see which Operating System class you need to take!)
In addition to exploring concepts such as synchronization, virtual memory,
processes, file systems and virtualization, students will develop elements
of a fairly complete operating system during the course of the semester.
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| Instructor |
Bill Cheng
(click to see office hours)
E-mail:
<bill.cheng@usc.edu>. (Please do not send HTML-only e-mails.
They will not be read.)
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| Time |
TuTh 9:30am - 11:30am |
| Location |
OHE 122 |
| TA #1 |
Zhuojin Li,
E-mail:
<zhuojinl@usc.edu>
Office Hours: Wed 4:00pm - 6:00pm on Zoom
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| TA #2 |
Bowen Song,
E-mail:
<bowenson@usc.edu>
Office Hours: Mon 4:30pm - 6:30pm on Zoom
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| Grader |
Kiran Kilingar Nadumane,
E-mail:
<kilingar@usc.edu>.
(If needed, the grader will hold office hours the week after the announcement of each assignment's grades.)
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| Midterm Exam |
during class, (NEW) [9:30:00am-10:10:00am), Tue, 7/5/2022 (firm).
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| Final Exam |
(NEW) [9:30:00am-10:10:00am), Tue, 8/2/2022 (firm).
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Class Resources
| Description |
: |
textbooks, topics covered, grading policies, additional resources, etc.
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| Lectures |
: |
information about lectures (and lectures slides in PDF format).
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| Videos |
: |
information about DEN/D2L lectures and discussion sections videos.
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| Discussions |
: |
information about discussion sections.
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| Projects |
: |
programming assignments (please also see important information about the class projects
below.)
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| Forum |
: |
Google Group online forum for discussing
course materials and programming assignments. You are required to be
a member of this group. (This group is initially by invitation only.)
Please do not send request to join this group until after the first lecture.
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(in reversed chronological order)
- 7/27/2022:
The final exam will be a 40-minute long take-home exam (open book and open notes),
and it will be conducted in the same manner as the midterm exam (please refer to the 6/28/2022 news item for the basic procedure
and replace the date and time with what's appropriate for your final exam).
No matter how late you start your exam, your exam must end at the same time as everyone else who is taking the same exam.
The final exam will cover everything from slide 30 of
the 2nd part of Lecture 13 to slide 53 of the 2nd part of Lecture 15,
PLUS, from slide 43 of
the 2nd part of Lecture 17 to the last slide of Lecture 29.
Also included are discussion section materials from Discussion 8
through Discussion 13.
Since the 2nd part of the course depends on stuff covered by the midterm,
I cannot say that I will not ask anything covered by the midterm and
you do need to know the material covered by the midterm. Therefore, it would
be more appropriate to say that the final exam will focus on the material
not covered by the midterm.
Regarding what types of questions will be on the exam, please see
the Exams section of the course description web page.
Regarding regrade policy, please see
the Regrade section of the course description web page.
Please note that if you are asked to run the Stride Scheduling algorithm, to get any credit,
you must run the algorithm described in Lecture 28
(and not the one in the textbook).
Here is a quick summary of the final exam topics (not all topics covered may be listed):
- Ch 3 - Basic Concepts
- Ch 4 - Operating-System Design
- devices
- virtual machines, microkernels
- Ch 5 - Processor Management
- threads implementation strategies
- threads implementations
- interrupts
- scheduler activations model
- scheduling
- Ch 6 - File Systems
- the basics of file systems
- performance improvements
- crash resiliency
- directories and naming
- RAID, flash memory, case studies
- Ch 7 - Memory Management
- Kernel assignments 2 & 3
- discussion section slides
- spec
- FAQ
- my posts to class Google Group
- 7/26/2022: Please download, fill out, sign,
and submit the Final Exam Academic Integrity Honor Code Pledge as soon as possible.
Please understand that if I don't get a signed pledge from you, you will not be able to download your final exam next Tuesday
because I need you to promise me that you won't cheat before you can download your exam.
- 7/1/2022:
- Zhuojin is sick and lost his voice and cannot conduct the discussion section today.
So, I will be conducting the primary live discussion remotely on Zoom today. Please don't go to OHE 122 today.
I will also be conducting the secondary live discussion using the same link Zhuojin is using. Sorry about the inconvenience and the short notice.
- 6/28/2022: Midterm rehearsal will be on Thursday, 6/30/2022 at 10:30am (i.e., exam start time is 10:30:00) USC time.
The starting point of your midterm rehearsal is at:
Below is the instructions for the midterm rehearsal (this will also be the instructions for your midterm exam, with a different start time and start page).
I have gone over all the information below during live Lecture on 6/28/2022.
For this web page, we will use the notation that the midterm rehearsal starts at X:30:00 and ends at (X+1):10:00 (for the midterm rehearsal, X = 10; for the actual midterm, X = 9).
As mentioned in live Lecture on 6/28/2022, the left side of a time interval is "closed" (i.e., including the left timestamp)
and the right side of a time interval is "open" (i.e., up to but not including the right timestamp).
If your exam time is different, please make adjustments accordingly.
- Make sure you have setup an e-mail filter to never miss an e-mail from <bill.cheng@usc.edu> (and never have it go into your spam folder).
- To get ready, please do the following 5 minutes BEFORE X:30:00.
- Display a clock app and a web browser as shown.
- Make sure you have downloaded and installed the Panopto Recorder.
If you have an offline desktop recorder that can record your desktop into an MP4 file, you can use that instead of the Panopto Recorder.
- Start the Panopto Recorder just in case you may lose Internet connection later.
Make sure Panopto is configured correctly (see the Checklist).
Don't start recording your desktop yet.
- Have your submission PIN handy because you will need it later. (Your submission PIN is the same for all programming assignments and exams.)
- Set an alarm for (X+1):09:00 to remind yourself that the exam is about to end soon (and make sure the time on your alarm clock is correct).
- If your machine is known to crash from time to time, you should reboot your machine and don’t run anything you don’t need for your exam.
- About 3 minutes before X:30:00, click on the midterm rehearsal start page mentioned above to start your midterm rehearsal.
- Follow the instruction and enter your USC Net ID and your submission PIN and click on submit. Please remember that your submission PIN is the same as your programming assignments submission PIN.
- In the next page, there are 2 links:
- The first link is for downloading a ZIP file which contains the exam questions (PDF file) and an answers text file.
Click on it to download the ZIP file and then open it.
(With some browsers, you will have to copy the link and paste it into a new browser tab in order for download to be successful.)
Save the answers text file on your desktop for easy access (don't make a copy of it, just work on this copy so you won't end up submitting the wrong file).
- The second link is for submitting your answers text file when you are done.
You should click on it immediately to open a new tab in your browser and look at the submission web page.
Right above the submission web form, you should see the current time on the submission server. If that time
does not correspond to your desktop clock app, you need to figure out how to fix your desktop clock app to sync your desktop clock
with a recommended clock server for your computer.
- You will get a backup e-mail with the same content as the web page mentioned above. It's just a backup, so don't wait for it.
- You can work on your exam as soon as you got the ZIP file
- If something is not working correctly, please send me an e-mail to as soon as possible (but please keep in mind that e-mail can take a very very long time to get delivered).
- Go to your desktop and click open the answers text file and work on your exam and save your modified answers text file regularly.
Feel free to make submissions if you are done early. Again, it's not a good idea to work on a copy of the answers text file because
you may end up submitting the wrong answers text file and there's nothing I can do if that happens! You are responsible for making sure
that you submit the correct file.
- When your alarm goes off at (X+1):09:00, you need to wrap things up and get ready to submit your exam answers text file.
- At (X+1):10:00, you must stop working on your answers. Save your answers text file and go to the submission web page.
(Of course, if you have already made a successful submission and have saved a copy of the ticket you got and
you haven't changed your answers, you are done and you can stop right here. But if you want to continue to work on your exam, that's fine too as long as
you have made at least one submission before (X+1):13:00.)
- To make a submission, first reload/refresh the submission web page and make sure that you are seeing the current time on the submission server right above the submission web form.
If reloading the web page failed, you should check to see if you can reach other websites.
If you cannot reach other websites, then you don't have a Internet connection and you must
follow the instructions to use Panopto to record your desktop and your exam answers and
take photos of your answers and e-mail photos of your exam answers to me.
If you can reach other websites, then you should continue to try to access the submission web page.
If reloading the web page was successful, you must fill out the submission web form and
click on the Choose File button and select the answers text file that you have filled out and saved.
Click on the Upload button. If you get any popup messages, please read them carefully and follow
the suggestions there (there is nothing I can do if you submit the wrong file).
If the submission server is busy, you should not be surprised because many students
are making submissions simultaneously. So, all you have to do is to keep submitting your answers text file
repeatedly until you can make a successful submission (i.e., you are presented with a submission ticket and
the ticket looks right).
You should save a copy of that ticket by saving the web page you see as a PDF file.
It's your responsibility that you have submitted the correct answers text file.
If you cannot reach the submission server after many tries, but still have Internet connectivity, it is possible (although unlikely)
that the server is down or unresponsive. In this case, you should
follow the instructions to use Panopto to record your desktop and your exam answers and
take photos of your answers and e-mail photos of your exam answers to me.
(Of course, for the rehearsal, you probably shouldn't just click Send since the e-mail will go to me. You can change the recipient e-mail address to yourself and then click Send.)
Then go back and continue to make a submission using the web form and maybe you will be able to connection to the submission server this time around.
The current item is summarized in the flowchart below.
Since this is a rehearsal, I would strongly recommand and everyone try out the
procedure to use the Panopto Recorder to record your desktop and your exam answers and
take photos of your exam answers (and you can e-mail the photos to yourself as a test)
and try it for a few times until you feel comfortable with the procedure just in case you may lose your Internet connection
when you are submitting the exam answers during the real exam.
Also, try out different scenarios such as disabling wifi on your laptop to simulate the loss of Internet connectivity
so you know what to expect.
Please understand that if you submit late (i.e., any time at or after (X+1):13:00),
I have to follow the rules I mentioned in class and deduct 5% for every late minute. For example:
- If your submission timestamp is ≥ (X+1):13:00 and ≤ (X+1):13:59, 5% will be deducted.
- If your submission timestamp is ≥ (X+1):14:00 and ≤ (X+1):14:59, 10% will be deducted.
- If your submission timestamp is ≥ (X+1):15:00 and ≤ (X+1):15:59, 15% will be deducted.
- If your submission timestamp is ≥ (X+1):16:00 and ≤ (X+1):16:59, 20% will be deducted.
- ...
I cannot make an exception for any student. If you are not familiar with all the rules, please watch the recorded live Lecture video on 6/28/2022.
VERY IMPORTANT: As mentioned in live Lecture on 6/28/2022,
I cannot accept "my machine crashed when I was making a submission" as an excuse for late submission unless you have a video to prove it
(please see slide 30 of the live Lecture on 6/28/2022 slides for instructions).
If you know that your machine is prone to crashing or random rebooting (only you would know that),
you should do a complete shutdown of your machine and reboot your machine into a clean state
at least 5 minutes before the start of the exam and don't run anything on your machine other than what's required to take the exam.
(It's a good idea to do that even if your machine is not prone to random crashes or reboots.) And most importantly,
when you have finished your first pass through the exam, make a submission right away!
Then every time you make a change in your answers, make another submission.
Remember, you can make as many submissions as you'd like and by default, we will grade your last submission.
If you are still working on your first pass at (X+1):10:00, you must stop working on your exam and make a submission immediately!
After you have made an on-time submission, you can continue to work on your exam and if you make changes, make another submission. This way, you can
avoid late penalty because you would always have a submission that was on time.
If you are not familiar with the procedure of making an exam submission, you should practice by going through the midterm exam rehearsal procedure as many times as you'd like.
If you have lost the midterm rehearsal link, please send me e-mail.
If anything is not clear, please feel free to ask me.
- 6/26/2022: Please download, fill out, sign,
and submit the Midterm Exam Academic Integrity Honor Code Pledge as soon as possible.
(Please note that submitting a signed pledge doesn't mean that you cannot decide to opt out of the exam later.)
Please understand that if I don't get a signed pledge from you, you will not be able to download your midterm exam this coming Tuesday
because I need you to promise me that you won't cheat before you can download your exam.
- 6/24/2022:
The midterm exam will be a 40-minute long take-home exam (open book and open notes).
The midterm exam will cover everything from the beginning of the
semester to slide 21 of Lecture 17 Part 1 on 6/23/2022,
MINUS Chapter 5 (i.e., material in Ch 5 is excluded from the midterm, i.e.,
slides 30 through 60 of Lecture 13, all slides in Lecture 14,
and slides 4 through 53 of Lecture 15).
Also included are discussion section slides from Discussion 1
through Discussion 7.
Regarding what types of questions will be on the midterm, please see
the Exams section of the course description web page.
Here is a quick summary of the midterm exam topics (not all topics covered may be listed):
- Ch 1 - Introduction
- introduction
- a simple OS
- files
- Ch 2 - Multithreaded Programming
- thread creation, termination
- thread synchronization
- thread safety, deviations
- Ch 3 - Basic Concepts
- context switching, I/O
- dynamic storage allocation
- static linking and loading
- booting
- Ch 4 - Operating-System Design
- a simple system
- storage management
- Warmup assignments 1 & 2
- discussion section slides
- specs
- FAQs
- my posts to class Google Group
- Kernel assignment 1
- discussion section slides
- spec
- FAQ
- my posts to class Google Group
Please note that kernel 1 is included in the midterm coverage but Chaper 5 is not.
This mean that I can ask weenix-specific questions in the midterm exam.
- 6/12/2022:
- Slight change of plan for this week's primary live lectures. As mentioned previously, for this week, I will have 3 hours of office hours
11am to 2pm on Monday (6/13) and Wednesday (6/15). I will be going over the administrative stuff and do a quick recap
of the pre-recorded lecture videos at the beginning of these office hours and this part will be recorded and posted on D2L as the "primary live lectures".
Please use my office hour Zoom link to access these office hours.
- 6/9/2022:
- Due to a family emergency (please see my post in the class Google Group today), today's secondary live lecture will end 30 minutes earlier (and will end at 11am).
To make up the lost time, today's office hour will be 30 minutes longer, although I need to move office hours to a later time today.
So, today's office hour will go from 6pm to 7:30pm. Sorry about the inconvenience and the short notice.
- 6/7/2022:
- Due to a family emergency (please see my post in the class Google Group today), there will be no live lectures and office hours next Tuesday (6/14) and Thursday (6/16).
Instead, I will post pre-recorded primary live lecture videos for next Tue and Thu and I will have 3 hours of office hours from 11am to 2pm (corrected)
next Monday (6/13) and Wednesday (6/15). Sorry about the inconvenience.
- 6/2/2022:
- Due to a family emergency (please see my post in the class Google Group today), for the next 4 lectures (on 6/7, 6/9, 6/14, and 6/16),
I will be joining the primary live lecture on Zoom as a co-host remotely.
As usual, I would go for 10-20 minutes to talk about administrative stuff and do a quick recap of what's in the pre-recorded videos.
Then I will shut down the primary Zoom and start the secondary live lecture to answer your questions in breakout rooms all the way to 11:30am.
So, the only difference is that you shouldn't go to OHE 122 on those days. Sorry about the inconvenience.
- 5/28/2022:
- I have noticed that for many of the videos, if you start the video from the very beginning, the video would appear to be frozen or looping.
Here's what you can do. Below the lecture slides on the right, there is a row of buttons/controls that looks like the following:
You can click on the fast-forward 10 seconds button (3rd from the left) then click on the fast-reverse 10 seconds button (2nd from the left) and that should get it unstuck.
- 5/27/2022:
- The result of the Kernel Grading Survey is as follows:
- 9 votes for keeping it at 50%
- 4 votes for 25%
- 1 vote for 20%
So, we will keep it at 50%
- 5/24/2022:
- During today's live lecture, I mentioned that I will create a survey and ask you to vote on something related to kernel assignment grading.
Please visit the Kernel Grading Survey page, read what this is all about, and cast your vote by the end of Thursday this week.
- 5/18/2022:
- As it turns out, I don't have to go to the court house tomorrow! So, I will be giving the primary live lecture tomorrow at 9:30am in OHE 122!
- 5/12/2022:
- Watch this area for important announcements.
- To get user ID and password for accessing protected
area of this web site, please visit the request access page after summer session starts and submit the requested information.
(You do not have to be registered for the course to get the password. You just need to have an USC e-mail address.)
- Please do not send request to join the
class Google Group until after the first lecture.
Some people mistakenly think that this is an introductory CS class! This class has CS prerequisites! In the official syllabus, it is listed that the prerequisites are:
(CSCI 201L or CSCI 455x) and (EE 357 or EE 352L)
Please see:
Apparently, they are the prerequisites for undergraduate students only.
The CS department would waive these prerequisites for graduate students.
Since undergraduate students are required to take CS 350 for OS credit,
there should only be graduate students enrolled in CS 402. Therefore,
these prerequisites are really not prerequisites.
They should be considered recommended preparation for graduate students.
The basic idea behind these prerequisites is that you are expected to know
how to program and you are expected to know something about computer architecture
(such as what a CPU does).
The programming assignments of this class will be very demanding.
You will be required to write C code. Since C is
a proper subset of C++, knowing C++ well would give you enough
background. However, some of the things that available in C++,
such as strings and streams, are not be available in C. So, you need
to know how to do things such as
manipulating null-terminated array of characters
(using functions such as strchr, strrchr, strlen, strcmp, strncpy, etc.)
and performing console and file I/O
(using functions such as printf/snprintf, fread/fwrite, read/write, fgets, etc.)
in C.
No other programming language will be accepted.
We will not teach C in this class.
You are expected to pick up C on your own if you are not familiar with it.
You should also get familiar with the Unix/Linux
development environment (vi/pico/emacs, cc/gcc, make, etc.)
You are expected to know how to use Unix/Linux.
If you are not familiar with Unix/Linux,
please read Unix for the Beginning Mage, a tutorial written by Joe Topjian.
Unfortunately, looks like this book has just disappeared from the web.
You can also visit UNIX Tutorial for Beginners
or Learn tcsh in Y Minutes.
If you already know how to use Unix/Linux before and just need a refresher,
please review my summary of some commonly used Unix commands and my tcsh scripting tutorial.
All programming assignments must run on a 32-bit Ubuntu 16.04.
The kernel programming assignments will only work on a 32-bit Ubuntu 16.04 system..
Therefore, you should install a 32-bit Ubuntu 16.04
on your laptop or desktop as soon as possible and start using it right away.
If you do not have a personal laptop or desktop that runs Windows or Mac OS X, please contact the instructor as soon as possible.
If you are considering buying a laptop, this class would work best with an Intel-based laptop that runs Windows or Mac OS X.
If the only computer you have access to is the new Mac running on a non-Intel/AMD CPU,
then it may not be possible to install VirtualBox into your machine. If that's the case,
please read here.
If a student registered late for this class or could not be present
at the beginning of the summer session,
the student is still required to turn all projects and homeworks
on time or the student will receive a score of 0 for these assignments.
No exceptions!
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