CSCE 351 Operating System Kernels
Fall 2001
Steve Goddard
Team Programming Assignment 3 (PA3), November 12
Due: 6:00pm November 29
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Messages, Messages, everywhere!
In this assignment each team will modify the MINIX kernel to keep track of the number of
messages sent from process (or task) i to process (or task) j. Decide what you should do with
messages generated by interrupts. That is, decide whether messages sent from interrupts to
device drivers (I/O tasks) should be counted in this matrix and then implement your design.
Justify your decision.
Print a matrix displaying the message passing count between all processes/tasks (and interrupts if
appropriate) when the F4 key is hit.
Does the matrix printed out show all messages sent in the system? If not, which messages are
not counted.
How many messages are sent for a file read less than or equal to one block? How many
messages are sent for a file read of k blocks? Does the storage device affect the number of
messages sent?
Grading Policy for Programs
The programs you hand in should work correctly and be documented. When you hand in your
programming assignment, you should include:
1. A program listing containing in-line documentation clearly identifying what changes you
made. Only turn in files that you changed (or created).
2. A separate (typed) document of approximately two pages describing the overall program
design, a verbal description of "how it work,s" and design tradeoffs considered and made (if
any). Also include answers to the questions asked above.
3. A separate description of the tests you ran on your program to convince yourself that it is
indeed correct and how you timed the changes in performance. Also describe any cases for
which your program is known not to work correctly.
