UTSA CS 3733 Operating Systems

CS 3733 Operating Systems, Page Replacment Review Solution

fifo

1  2  3  4  2  5  2  3  2  1  2  5  2  1  
-  -  -  -     -  -  -     -     -  -     
1  1  1  2  2  3  4  5  5  2  2  3  1  1  
   2  2  3  3  4  5  2  2  3  3  1  5  5  
      3  4  4  5  2  3  3  1  1  5  2  2

Number of page faults: 10 out of 14

lru

1  2  3  4  2  5  2  3  2  1  2  5  2  1  
-  -  -  -     -     -     -     -        
1  1  1  2  3  4  4  5  5  3  3  1  1  5  
   2  2  3  4  2  5  2  3  2  1  2  5  2  
      3  4  2  5  2  3  2  1  2  5  2  1

Number of page faults: 8 out of 14

optimal

1  2  3  4  2  5  2  3  2  1  2  5  2  1  
-  -  -  -     -           -              
1  1  1  4  4  5  5  5  5  5  5  5  5  5  
   2  2  2  2  2  2  2  2  2  2  2  2  2  
      3  3  3  3  3  3  3  1  1  1  1  1

Number of page faults: 6 out of 14

second chance

1  2  3  4  2  5  2  3  2  1  2  5  2  1  
-  -  -  -     -     -     -     -        
1* 1* 1* 2  2* 4* 4* 2  2* 3* 3* 2  2* 2* 
   2* 2* 3  3  2  2* 5  5  2  2* 1  1  1* 
      3* 4* 4* 5* 5* 3* 3* 1* 1* 5* 5* 5*

Number of page faults: 8 out of 14