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Unformatted text preview: CS 162, Midterm #1, Spring 1998 CS162, Spring 1998 Midterm #1 Professor Alan Smith Problem #1 Explain the difference between a process and a thread. Define both. What are the tradeoffs between using one and using the other? (14) Problem #2 We discussed two mathematical quantities that are reasonable targets for optimization in scheduling: minimizing ave(f(i)) and minimizing ave(f(i)/s(i)). Please explain what each is, and explain why we would like to minimize it. (14) Problem #3 Please provide code (of the same sort used in class) that will implement P & V using the "swap" operation described in class. (18) Problem #4 What is the difference between an interrupt and a trap? Define both. Please give at least two examples of each. (12) Problem #5 Why does rollback usually require checkpoints? Please define both terms and explain. (11) Problem #6 file:///C/Documents%20and%20Settings/Jason%20Raft...%20Spring%201998%20%20Smith%20%20Midterm%201.htm (1 of 2)1/27/2007 4:01:44 PM CS 162, Midterm #1, Spring 1998 For each of FIFO, SRPT, and RR (Q=.25), and for the following set of arrival and service times, please show a time line for which process is executing, and compute the mean flow time. Show your computations. (We might give partial credit, if you made a simple and obvious error; we're not going to try to decode your calculations if they aren't obvious.) (15) arrival service A 0 B .3 C 1.1 1.5 .8 1.1 Problem #7 For the following two cases, please either show a complete safe sequence or show that there isn't one. (16) PROCESS hasX hasY max needsX max needsY A B C D 10 0 30 50 20 70 10 80 75 50 60 100 50 90 40 220 a. available: X: 40 Y: 40 b. available: X: 40 Y: 35 Posted by HKN (Electrical Engineering and Computer Science Honor Society) University of California at Berkeley If you have any questions about these online exams please contact http://hkn.eecs.berkeley.edu/student/online/cs/162/1998/<mailto:examfile@hkn. eecs.berkeley.edu>MAILTO:examfile@hkn.eecs.berkeley.edu file:///C/Documents%20and%20Settings/Jason%20Raft...%20Spring%201998%20%20Smith%20%20Midterm%201.htm (2 of 2)1/27/2007 4:01:44 PM ...
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This note was uploaded on 05/17/2009 for the course CS 162 taught by Professor Kubiatowicz during the Spring '02 term at University of California, Berkeley.
 Spring '02
 Kubiatowicz
 Computer Science

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