CS 3650 - Computer Systems

Introduces the basic design of computing systems, computer operating systems, and assembly language using a RISC architecture. Describes caches and virtual memory. Covers the interface between assembly language and high-level languages, including call frames and pointers. Covers the use of system calls and systems programming to show the interaction with the operating system. Covers the basic structures of an operating system, including application interfaces, processes, threads, synchronization, interprocess communication, deadlock, memory management, file systems, and input/output control.

Interesting Links

• main is usually a function
• Intel 5-level Paging
• Lockless synchronization

Resources

• Bottlenose - Find and submit homework assignments.
• Piazza - Class discussion.
• MARS 4.5 - The MIPS simulator we'll be using.
• MARS Syscalls - Also the rest of the MARS docs.
• Operating Systems, Three Easy Pieces - Online text.
• Xv6 Unix Source - Another online "text".
• Prof Cooperman's Course Page - Lots of links to great resources.
• Linux / Unix help - How to use standard *nix tools.
• Upper Class Tutoring
• Nat's Lecture Notes - Probably confusing, but includes most code shown in class.

Lecture Sections

Feel free to come to either lecture as long as there is an available seat.

3650-01	IV 019	Tu/Fr 9:50-11:30am
3650-02	IV 019	Tu/Fr 1:35-3:15pm

Office Hours

Nat Tuck	NI 132E	Mo 2pm-3pm, Fr noon-1pm	ntuck ⚓ ccs.neu.edu
Supraja Krishnan	Snell Library 45	Tu 3:30pm-5:30pm	krishnan.sup ⚓ husky.neu.edu
Nakul Camasamudram	WVH 362	We 10am-noon	camasamudram.n ⚓ husky.neu.edu
Tanmay Ulhas Budukh	WVH 462	Th 8-10am	budukh.t ⚓ husky.neu.edu
James Wu	WVH 362	Sa 6-7pm	wu.jame ⚓ husky.neu.edu
Samuel Vogel	SL 045	Tu noon-1pm	vogel.sa ⚓ husky.neu.edu
Jack Elliot	WVH 462	Fr 3-4pm	elliott.jame ⚓ husky.neu.edu

Textbook

Computer Organization and Design: The Hardware/Software Interface
Patterson & Hennessy
Fifth Edition

We'll also be using Operating Systems, Three Easy Pieces and the Xv6 Unix Source code, available online.

Work For This Class

Homework & Challenge Assignments

Assignments will be assigned and submitted through Bottlenose.

Late assignments will be penalized 1% for every hour late, except for the last assignment which must be submitted on time for credit.

Challenge assignments are just like homework assignments, except they're significantly more difficult and will be graded more harshly.

Participation

Participation has several parts:

• Answering questions in class when randomly selected.
• Asking good questions and giving good answers on Piazza.
• Attending office hours with well prepared questions.

Grading

Homework	65%
Challenges	30%
Participation	5%

Schedule

Here's how the semester is likely to play out. Details subject to change.

Week	Dates	Topics & Reading	Work Due
1	Sep 08	Introduction	Read: P&H Ch 1, 2
2	Sep 12 Sep 15	ASM: Functions, Iteration, Recursion ASM: "Design Recipe"	HW1: The CCIS Linux Server Read: P&H Appendix A6, A9, A10, Green Card
3	Sep 19 Sep 22	Processes & Memory Layout ASM: Syscalls, I/O, Memory Allocation	HW2: Simple ASM Read: OSTEP ch 4, 13 Read: P&H ch 2
4	Sep 26 Sep 29	C: Functions, Pointers, Arrays, and The Stack C: The Heap; A Simple Parser	HW3: Less Simple ASM Read: OSTEP ch 14 Read: P&H 2.14
5	Oct 3 Oct 6	UNIX Syscalls: fork, exec, waitpid Building a Shell	HW4: Shell Command Parsing Read: OSTEP ch 5
6	Oct 10 Oct 13	I/O with read & write; Process table & Virtual Memory Shared Memory & Semaphores	Challenge 1: UNIX Shell Read: OSTEP 15, 16, 18, 31 Read: P&H 5.6, 5.7
7	Oct 17 Oct 20	Threads, mutexes, data races Cond vars, atomics, deadlocks	HW5: Inter-Process Communication Read: OSTEP 26, 27, 28, 30
8	Oct 24 Oct 27	Memory Allocation: Free List Memory Allocation: Optimizations	HW6: Inter-Thread Communciation Read: OSTEP ch 17 Read: P&H ch 6.1 - 6.6
9	Oct 31 Nov 3	Memory Allocation w/ Threads Existing Systems: Caches, Multiple Arenas	HW7: Memory Allocator Read: P&H ch 5.1 - 6.4
10	Nov 7 Nov 10	Operating Systems: Kernels A Quick Look at xv6	Challenge 2: Thread-safe Allocator
11	Nov 14 Nov 17	File Systems: FAT, vsfs Intro to FUSE	HW8: Examining xv6 Read: OSTEP ch 39, 40
12	Nov 21	File Systems: ext*	HW9: Simple File System Read: OSTEP ch 41, 42, 43
13	Nov 28 Dec 1	File Systems: log-based, COW Solutions for Concurrency	Read: OSTEP ch 32, 33
14	Dec 5	Wrap Up	Challenge 3: Fancy File System Read: OSTEP ch 47

Policies

Special Accomodations

Students needing disability accommodations should visit the Disability Resource Center (DRC).

If you have been granted special accomodations either through the DRC or as a student athlete, let me know as soon as possible.

Code Copying & Collabaration Policy

Copying code and submitting it without proper attribution is strictly prohibited in this class. This is plagiarism, which is completely unacceptable.

Details:

• For all assignments, you should personally write your code either from scratch or using only the starter code provided in the assignment.
• For team assignments, you can share code with team mates.
• Sharing your code with other students is not allowed.
• Looking at code written by other students is not allowed.
• You can read code from the internet or text books, but copying it - even to use as a starting point for your code - is not allowed.
• This includes code shown in lecture. Do not copy code without attribution.

Collaboration and Attribution:

Since it's not plagiarism if you provide attribution, as a special exception to these rules, any code sharing with completely clear attribution will not be treated as a major offense. Instead, credit will be split between the writers of the code.

In order to qualify for this exception, every collaborator must include a prominent notice either as a multi-line comment at the top of the submitted single source file or at the top of a submitted README file identifying all collaborators.

For example, if four students work together to do a homework, the submission will be graded as usual and then the points will be split evenly four ways as long as the collaboration is clearly indicated in the submissions. Alternatively, if a student copies half their work from Stack Overflow with proper credit, they'll get half the points.

Penalities:

First Offense:

• Your final grade will be an F.
• You will be reported to OSCCR and CCIS.

Posting Work Online

You want to post your work to Github. I want to re-use assignments next semester without students submitting old homework.

1. Solutions to "Homework" assignments may not be posted publicly.
2. Solutions to "Challenge" assignments may be posted publicaly *after* a late submission would be worth no points (4 days after due date).