CMSC 714 Midterm (Fall 2008)
(1) This exam is closed book, closed notes, and closed neighbor.
(2) You have 70 minutes to complete this
exam. If you finish early, you may turn in your exam at the front of the room
and leave. However if you finish during the last ten minutes of the exam
please remain seated until the end of the exam so you don't disturb others.
(3) Write all answers in the supplied exam
booklet. Start each new problem (but not sub-problem) on a new page.
(4) Partial credit will be given for most questions
assuming I can figure out what you were doing.
(5) Please write neatly. Print your answers
if your handwriting is hard to read. If you write something, and wish to cross
it out, simply put an X through it.
1. (25 points) Define
and explain the following terms:
A. Data Parallelism
B. Space Sharing vs. Time Sharing
D. Owner Computes
2. (20 points) Scheduling
A. Explain why co-scheduling is
important, and how it can be obtained explicitly or implicitly.
B. What is symbiotic space sharing
and how can it improve system performance?
3. (20 points) Compare
and contrast fat tree and 3-d torus networks in their ability to handle different
types of message passing operations including: nearest neighbor, reduction, and
4.(20 points) Explain
three issues that must be overcome when programming the Cell processor
that are not present (or as significant) on a cluster of commodity workstations
5.(15 points) Explain
how Terra’s MTA is able to achieve good performance without caches.