January 16, 2007

COMS 4118 (Operating Systems I)

Henning Schulzrinne

Dept. of Computer Science

Columbia Universityhttp://www.cs.columbia.edu/~hgs

January 16, 2007

Course mechanics

• Instructor: hgs+4118@cs.columbia.edu– My office hours: Tuesdays, 4-5 pm, 450F CSB or by appointment

• please contact Rosemary Addarich (rosemary@cs.columbia.edu)• check MICE for exceptions

• TA: Zhiyang Cao

– office hours: Wednesdays, 3-5 pm or by appointment• Web page --> basics, assignments

– http://www.cs.columbia.edu/~hgs/teaching/os• Wiki --> hints, assorted documents• Assignment upload, slides and mailing list via Courseworks• Will set up bulletin board for discussions

January 16, 2007

Structure of course

• Lectures - book material + background + discussion• Homework assignments• Midterm, final

January 16, 2007

Prerequisites

• CSEE W3827 (Fundamentals of Computer Systems)– understanding of computer system architecture– registers, cache, virtual memory, I/O, DMA, disks, etc.– interrupts– basic knowledge of what assembly language is

• COMS W3157 or W3101– understand how to use “make”, C compiler, gdb, …

• The C programming language– Java is also helpful

January 16, 2007

Course outline & topics

• Overview and history• Computer organization• VMWare & Linux kernel tutorial• Processes• IPC• Threads• CPU scheduling• Synchronization• Multi-processor systems

• Memory management• I/O• Disks and scheduling• File systems• Protection & security• Networking• Distributed systems

January 16, 2007

The deal

• Your responsibility– you’re all adults

– responsible for your own actions and scheduling choices

– if you don’t understand something, ask– Please note academic honesty policy: http://www.cs.columbia.edu/education/honesty

• discussion with others is encouraged - study groups, discussion board, etc.• zero tolerance for cheating or “outsourcing” homework• we’ll clearly identify group work• lock your files -- “just looking” is not acceptable

• Our responsibility– be responsive to your questions

– try to fix problems

January 16, 2007

Lectures

• Slides for each class– derived from book slides, but modified and enhanced

• Uploaded to Courseworks shortly before class– sometimes updated after class

• Class is on CVN– on-campus students can watch– after add/drop period

January 16, 2007

Assignments & Grading

• Grading:– 50% assignments– 20% midterm (closed book)– 30% final (cumulative, closed book)– 0% no “extra credit” work– will be curved

• 6 written assignments (every two weeks)– individually solved

• alternate with 6 Linux kernel assignments– groups of 3, all with the same score– each participant rates the others; non-contributors will be voted off the island

(onto their own island of like-minded “slackers”)

• Late policy– five late days– late assignments will not be graded, but you can submit partial assignments– at noon on due date

January 16, 2007

Programming assignments

• All programming assignments must be in C– Java, C++, Fortran, … are not acceptable– unless explicitly noted otherwise

• If you don’t know C, come back next year• Needed for Linux kernel (C)• Linux kernel assignments in group

– may do small programming assignments individually

January 16, 2007

Linux (kernel) projects

• Shell• Linux system call• CPU scheduling for multimedia• Disk paging• Network monitoring

subject to change…

January 16, 2007

Working with kernels

• Very different from standard applications• Part of a very large system (10s MLOC)

– side effects can be unpleasant– spend more time reading programs than writing them

• Debugging kernels– long build - boot - test cycle (--> batch jobs…)– limited debugging (printf)– asynchronous behavior -- hard to provide right stimulus

• “Heisenbugs”

January 16, 2007

CLIC lab

• All programs and kernels must boot & run on the CLIC machines– if not, zero credit– but you can develop at home, on your laptop, …

• You’ll need a CLIC account– https://www.columbia.edu/~crf/accounts/

• You will be assigned a particular CLIC machine for virtual machine use

• Some CLIC machines are for in-person use; others can only be accessed remotely

• No food or drink in CLIC– be considerate -- others are trying to concentrate