Design issues for Paging Systems

Conflicting Goals:

1) Explain the shape of each section indicated on the above curve:

a) (rising part of the curve)

b) (falling part of the curve)

2) Complete the following table assuming a FIFO page-replacement algorithm and four page frames allocated to the process.

References String: 1 2 3 4 1 2 5 1 2 3 4 5

Page Frames

Allocated = 4

                       
                       
                       
                       
 
Number of page faults?   Page-fault rate?
3) Complete the following table assuming the Optimal page-replacement algorithm and four page frames allocated to the process.

References String: 1 2 3 4 1 2 5 1 2 3 4 5

Page Frames

Allocated = 4

                       
                       
                       
                       
 
Number of page faults?   Page-fault rate?

4) Complete the following table assuming a LRU page-replacement algorithm and four page frames allocated to the process.

References String: 1 2 3 4 1 2 5 1 2 3 4 5

Page Frames

Allocated = 4

                       
                       
                       
                       
 
Number of page faults?   Page-fault rate?

5) Answer the following questions about implementation of the LRU Algorithm:

a) What information would we need to keep track of to implement LRU?

b) When would this information need to be updated?

c) Where would you store this information?