MC78 Homework 3 (Fall 1996)
Due: October 10, 1996
Do problem 8 from chapter 3 of the textbook; it is on page 142.
Do problem 11 from chapter 3 of the textbook; it is on page 142.
Do problem 19 from chapter 3 of the textbook; it is on page 143.
Do problem 26 from chapter 3 of the textbook; it is on page 144.
Consider three computer systems: a batch processing system, an
interactive timesharing system, and a single-user workstation. Now
consider two options for page-replacement. One is a global replacement
algorithm, in which all the processes' pages are considered for
replacement to free up page frames when necessary, using an LRU policy
or something similar. The other is a local replacement algorithm, in
which each process has its own pool of page frames, and when it needs
a to page something in replaces one of its own pages, again using LRU
or something similar. In this latter option, the size of each
process's pool of page frames is adjusted using the page fault
frequency (PFF) allocation algorithm, as described on page 122. As
described there, if not enough page frames are available to satisfy
the PFF algorithms demand for all the processes, one of them is
completely swapped out until memory demand recedes.
Discuss which of the three computer systems is best suited to the global
replacement algorithm, and which is best suited to the local algorithm
with PFF allocation.
Instructor: Max Hailperin