UGC NET CSE | June 2013 | Part 3 | Question: 63

Question

Working set model is used in memory management to implement the concept of

• A. Swapping
• B. Principal of Locality
• C. Segmentation
• D. Thrashing

Answer 1

Answer : Principal of Locality 

How ?

The "working set" can be referred as "parts of memory that the current algorithm is using" and is determined by which parts of memory the CPU just happens to access. If you are processing an array and storing the results in a table, the array and the table are your working set in this context.

This is discussed because the CPU will automatically store accessed memory in cache, close to the processor. The working set is a nice way to describe the memory you want stored. If it is small enough, it can all fit in the cache and your algorithm will run very fast. 

Or in other words we can say

The "working set" is an informal term meaning the memory that's being accessed "frequently" by an application or set of applications. 

Principal of Locality does the same thing as explained above.

There are 2 types of Locality of reference

1. Spatial locality : it says whenever we are looking for an element the chances are that ,that particular element will be present in a close proximity around the one which we have previously referred 

2. Temporal locality : it says least recently used element is going to be used again .

Answer 2

Ans B

• the working W(k,t) of a process at time {\displaystyle t} to be the set of information referenced in last k time units 
• the units of information in question are considered to be memory pages.
• It is assumed that  the process will access the same set  in the future. hence it follows principal of locality