a. What is false sharing in a multiprocessor system and how does it affect performance? Explain...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
a. What is false sharing in a multiprocessor system and how does it affect performance? Explain with one example. b. Consider the following C code: C. double x, y, 2; void first () { } y-x+3; z-y/2.0; void second() { y-2-3; In the sequential program first is called before second. [5 Marks] (i) What dependencies exist between first and second? Be specific, including line numbers and variable names. [3 Marks] (ii) Using examples from this code, explain what false dependencies are and how they can be eliminated. What are the disadvantages of removing these false dependencies? [3 Marks] With the help of any simple program or pseudo-code you wrote in your programming modules and answer the following questions. (i) What (if any) part of this program are inherently serial? (!!) [3 Marks] Does the inherently serial part of the work done by the program decrease as the problem size increases? Or does it remain roughly the same? [4 Marks] d. Give any two (2) reasons why a parallel version running on 2 or more processors of a sequential code might run slower than the sequential version? [2 Marks] a. What is false sharing in a multiprocessor system and how does it affect performance? Explain with one example. b. Consider the following C code: C. double x, y, 2; void first () { } y-x+3; z-y/2.0; void second() { y-2-3; In the sequential program first is called before second. [5 Marks] (i) What dependencies exist between first and second? Be specific, including line numbers and variable names. [3 Marks] (ii) Using examples from this code, explain what false dependencies are and how they can be eliminated. What are the disadvantages of removing these false dependencies? [3 Marks] With the help of any simple program or pseudo-code you wrote in your programming modules and answer the following questions. (i) What (if any) part of this program are inherently serial? (!!) [3 Marks] Does the inherently serial part of the work done by the program decrease as the problem size increases? Or does it remain roughly the same? [4 Marks] d. Give any two (2) reasons why a parallel version running on 2 or more processors of a sequential code might run slower than the sequential version? [2 Marks]
Expert Answer:
Related Book For
Computer Organization And Architecture Themes And Variations
ISBN: 9781111987046
1st Edition
Authors: Alan Clements
Posted Date:
Students also viewed these programming questions
-
A crank arm consists of a solid segment of length b 1 and diameter d, a segment of length b 2 , and a segment of length b 3 , as shown in the figure. Two loads P act as shown: one parallel to -x and...
-
"internet radios" for streaming audio, and personal video recorders and players. Describe design and evaluation processes that could be used by a start-up company to improve the usability of such...
-
Someone offered the investment options to Hendry on January 1, 2023: 1. Hendry has to save up to 5 times the initial deposit of US $ 150,000/year. 2. The savings cannot be taken for 20 years until...
-
Draw the structures and give the names of all isomers of octane with Six carbons in their principal chains.
-
We sometimes investigate distributions on a circle. Find a Haar prior for a location parameter on the circle (such as , in the case of von Mises' distribution).
-
You are working for a car-battery manufacturer, and your boss complains that to be more competitive, the company needs to produce batteries that will last longer while minimizing the amount of metal...
-
Kerri Bates is reviewing his companys investment in a cement plant. The company paid $15,000,000 five years ago to acquire the plant. Now top management is considering an opportunity to sell it. The...
-
1. Identify products A and B 2. 3. CH3 dil. KMnO4 CrO3 A- B 273 K CH3 CH3 (A) A: OH B: OH OH CH3 CH3 (B) A: OH OH B: (C) A: OHCCH,CH,CH, CCH, B: HOOCCH,CH,CH, CH3 CH3 (D) A: B: OH -CH3 The electrode...
-
Consider the problem Ax = 0 2 4 1 -3 -1 3 4 -6 0 -1 3 4 (a) (2 points) Find the null space N(A). A = b and its reduced row echelon form Rx = c, with [1 0 11 || [10 0 1 00 LO O 2 0 -3 0 0 1 0 0 |N(A)...
-
How would each of the following affect the socially optimal rotation intervals for trees? a) An increase in the demand for real estate b) An increase in soil erosion on deforested land due to global...
-
Some investigators have concluded that Hotelling's rule does not apply. List two of Hotelling's assumptions that are inconsistent with the realworld oil situation.
-
Indicate whether the following statement is true, false, or uncertain, and explain your answer: If every type of water use were 100 percent nonconsumptive, the only major problems regarding the world...
-
Name the four conditions for settlement explained in this chapter. For one of them, explain a deterrent to reaching that condition and a remedy for that deterrent.
-
Imagine a world in which individuals cared only about themselves. Choose two of the following types of people and describe, in one paragraph each, how you think their behavior would differ in this...
-
Bricks & Mortar Co. (the Company), an SEC registrant, is a manufacturer of construction equipment. The Company has been in business for more than 50 years, operating profitably for the past 25....
-
In the series connection below, what are the respective power consumptions of R, R2, and R3? R R www 4 V=6V P1-3 W; P2=3W; and P3= 3 W OP10.5 W; P2-1 W; and P3= 1.5 W P1=1.5 W; P2=1 W; and P3= 0.5 W...
-
In the FRED database, find a variable that is available in both a seasonally adjusted form and a not seasonally adjusted form. Plot both over time and describe how large the seasonal variation in the...
-
An economic variable is persistent if declines in the variable tend to be followed by more declines, and increases by more increases. This question asks you to study the persistence of the civilian...
-
It has been argued that the stock market predicts recessions. Using quarterly data since 1961, plot the real value of the stock market index (the Wilshire 5000 index in the last month of the quarter...
Study smarter with the SolutionInn App