Assignment : 4

Assignment : 4

Set A

i. Write the simulation program to implement demand paging and show the page

scheduling and total number of page faults for the following given page reference string.

Give input n as the number of memory frames.

Reference String : 12,15,12,18,6,8,11,12,19,12,6,8,12,15,19,8

1) Implement FIFO

CODE:

👇

1. #include<stdio.h>
2. struct frmnode
3. {
4. int pno;
5. }frames[20];
6. int n;
7. 
   
8. int page_found(int pno)
9. {
10. int fno;
11. for(fno=0; fno<n; fno++)
12. {
13. if(frames[fno].pno==pno)
14. return fno;
15. }
16. return -1;
17. }
18. 
    
19. int get_free_frames()
20. {
21. int fno;
22. for(fno=0; fno<n; fno++)
23. {
24. if(frames[fno].pno== -1)
25. return(fno);
26. }
27. return(-1);
28. }
29. 
    
30. int get_fifo_frame()
31. {
32. static int fno = -1;
33. fno = (fno+1)%n;
34. return(fno);
35. }
36. 
    
37. int main()
38. {
39. int p_request[] = {5,8,10,14,10,9,5,10,8,5,1,10,9,12,10};
40. int size = sizeof(p_request)/4;
41. int page_faults = 0, i, j, fno;
42. printf("\nHow many frames:\t");
43. scanf("%d", &n);
44. for(i=0; i<n; i++)
45. {
46. frames[i].pno = -1;
47. }
48. 
    
49. printf("\nPageNO      Page Frames     Page Faults");
50. printf("\n--------------------------------------------------------");
51. for(i=0; i<size; i++)
52. {
53. j=page_found(p_request[i]);
54. if(j == -1)
55. {
56. page_faults++;
57. j = get_free_frames();
58. if(j == -1)
59. j = get_fifo_frame();
61. frames[j].pno = p_request[i];
62. printf("\n%4d\t",p_request[i]);
63. for(fno=0; fno<n; fno++)
64. printf("%4d",frames[fno].pno);
65. printf("\tYES");
66. }
67. else
68. {
69. printf("\n%4d\t",p_request[i]);
70. for(fno=0; fno < n; fno++)
71. printf("%4d",frames[fno].pno);
72. printf("\t NO");
73. }
74. }
75. printf("\n--------------------------------------------------------");
76. printf("\nNumber of Page Faults = %d", page_faults);
77. printf("\n");
78. }

2) Implement LRU

CODE:

👇

1. #include<stdio.h>
2. struct frmnode
3. {
4. int pno,counter;
5. } 
6. frames[20];
7. 
   
8. int n;
9. int page_found(int pno)
10. {
11. int fno;
12. for(fno=0;fno<n;fno++)
13. {
14. if(frames[fno].pno==pno)
15. return fno;
16. }
17. return -1;
18. }
19. 
    
20. int get_free_frame()
21. {
22. int fno;
23. for (fno=0;fno<n;fno++)
24. {
25. if(frames[fno].pno==-1)
26. return(fno);
27. }
28. return(-1);
29. }
30. 
    
31. int get_lru_frame()
32. {
33. int lrufno=0,fno;
34. for(fno=1;fno<n;fno++)
35. {
36. if(frames[fno].counter<frames[lrufno].counter)
37. lrufno=fno;
38. }
39. return lrufno;
40. }
41. void main()
42. {
43. int p_request[]={5,8,10,14,10,9,5,10,8,5,1,10,9,12,10};
44. int size=sizeof(p_request)/4,currtime;
45. int page_faults=0,i,j,fno;
46. printf("\n How many Frame: ");
47. scanf("%d",&n);
49. for(i=0;i<n;i++)
50. {
51. frames[i].pno=-1;
52. }
54. printf("\nPageNo    PageFrames    PageFault");
55. printf("\n------------------------------------------------");
56. currtime=0;
57. for(i=0;i<size;i++)
58. {
59. j=page_found(p_request[i]);
60. if(j==-1)
61. {
62. page_faults++;
63. j=get_free_frame();
64. if(j==-1)
65. j=get_lru_frame();
67. frames[j].pno=p_request[i];
68. frames[j].counter=currtime;
69. printf("\n%4d\t",p_request[i]);
70. for(fno=0;fno<n;fno++)
71. printf("%4d:%2d",frames[fno].pno,frames[fno].counter);
72. printf("\t:YES");
73. }
74. else
75. {
76. frames[j].counter=currtime;
77. printf("\n%4d\t",p_request[i]);
78. for(fno=0;fno<n;fno++)
79. printf("%4d:%2d",frames[fno].pno,frames[fno].counter);
80. printf("\t:NO");
81. }
82. currtime++;
83. }
84. 
    
85. printf("\n------------------------------------------------");
86. printf("\n Number of page_Faults=%d",page_faults);
87. printf("\n");
88. }

Set B:

I. Write the simulation program to implement demand paging and show the page

scheduling and total number of page faults for the following given page reference string.

Give input n as the number of memory frames.

Reference String : 12,15,12,18,6,8,11,12,19,12,6,8,12,15,19,8

1) Implement MFU

CODE:

👇

2. 
   
3. #include<stdio.h>
4. struct node
5. {
6.   int pno,frequency;
7. }
8.   
9. frames[20];
10. int n;
11.   
12. int page_found(int pno)
13. {
14.   int fno;
15.   for(fno=0;fno<n;fno++)
16.   {
17.     if(frames[fno].pno==pno)
18.       return fno;
19.   }
20.   return -1;
21. }
22.   
23. int get_mfu_frame()
24. { 
25.   int selfno=0,fno;
26.   for(fno=1; fno<n; fno++)
27.   {
28.     if(frames[fno].frequency>frames[selfno].frequency)
29.       selfno=fno;
30.   }
31.   return selfno;
32. }
33.  
34. int get_free_frame()
35. { 
36.   int fno;
37.   for(fno=0; fno<n; fno++)
38.   {
39.     if(frames[fno].pno==-1)
40.       return(fno);
41.   }
42.   return(-1);
43. }
44.  
45. void main()
46. {
47. int p_request[]={5,8,10,14,10,9,5,10,8,5,1,10,9,12,10};
48. int size=15;
49. int page_fault=0,i,j,fno;
50. printf("\nHow many frames :");
51. scanf("%d",&n);
52. 
    
53. for(i=0; i<n; i++)
54. {
55.   frames[i].pno=-1;
56. frames[i].frequency=0;
57. }
58.   
59. printf("\nPageNo      PageFrames         PageFault");
60. printf("\n----------------------------------------------------------");
61. for(i=0; i<size; i++)
62. {
63. j=page_found(p_request[i]);
64. if(j==-1) 
65.   {
66.     j=get_free_frame();
67.     if(j==-1)
68.     j=get_mfu_frame();
69. page_fault++;
70. frames[j].pno=p_request[i];
71. frames[j].frequency++;
72. printf("\n%4d\t",p_request[i]);
73. for(fno=0; fno<n; fno++)
74. printf("%4d:%2d\t",frames[fno].pno,frames[fno].frequency);
75. printf("YES");
76.   }  
77.   else
78. {
79. frames[j].frequency++;
80.     printf("\n%4d\t",p_request[i]);
81.   for(fno=0; fno<n; fno++)
82.   printf("%4d:%2d\t",frames[fno].pno,frames[fno].frequency);  
83.   printf("NO");
84.   }
85. }
86. printf("\n-------------------------------------------------------");
87. printf("\nNumber of Page Faults=%d",page_fault);
88. }   

             

Set C:

I. Write the simulation program to implement demand paging and show the page

scheduling and total number of page faults for the following given page reference string.

Give input n as the number of memory frames.

Reference String: 2,5,2,8,5,4,1,2,3,2,6,1,2,5,9,8

1) Implement MRU

CODE:

👇

1. #include<stdio.h>
2. struct frmnode
3. {
4.   int pno,counter;
5.   }
6.   
7.   frames[20];
8.   int n;
9.   
10.   int page_found(int pno)
11.   {
12.     int fno;
13.     for(fno=0;fno<n;fno++)
14.     {
15.       if(frames[fno].pno==pno)
16.         return fno;
17.      }
18.    return -1;
19.  }
20.  
21.  
22. int get_free_frame()
23. { 
24.    int fno;
25.    for(fno=0; fno<n; fno++)
26.    {
27.      if(frames[fno].pno==-1)
28.       return(fno);
29.     }
30.   return(-1);
31. }
32.   
33.   
34. int get_mru_frame()
35. {
36.   int mrufno=0,fno;
37.    for(fno=1; fno<n; fno++)
38.    {
39.    if(frames[fno].counter>frames[mrufno].counter)
40.    mrufno=fno;
41.    }
42.   return mrufno;
43. }    
44. 
    
45.  
46. void main()
47. {
48. int p_request[]={5,8,10,14,10,9,5,10,8,5,1,10,9,12,10};
49. int size=sizeof(p_request)/4,currtime;
50. 
    
51. int page_fault=0,i,j,fno;
52. printf("\nHow many frames :");
53. scanf("%d",&n);
54. for(i=0; i<n; i++)
55. {
56.    frames[i].pno=-1;
57.   }
58.   
59.   printf("\nPageNo      PageFrames         PageFault");
60.   printf("\n----------------------------------------------------------");
61.   currtime=0;
62.   for(i=0; i<size; i++)
63.   {
64. j=page_found(p_request[i]);
65. if(j==-1) 
66.      {
67.        page_fault++;
68.        j=get_free_frame();
69.        if(j==-1)//no free frame -do page replacement
70.        
71.   j=get_mru_frame();
72.   frames[j].pno=p_request[i];//load page in frame
73.   frames[j].counter=currtime;
74.   printf("\n%4d\t",p_request[i]);
75.    for(fno=0; fno<n; fno++)
76. printf("%4d:%2d\t",frames[fno].pno,frames[fno].counter);
77. printf("YES");
78.     }
79.    
80.   else
81.   {
82.   frames[j].counter=currtime;
83. printf("\n%4d\t",p_request[i]);
84.   for(fno=0; fno<n; fno++)
85.    printf("%4d:%2d\t",frames[fno].pno,frames[fno].counter);  
86.    printf("NO");
87.     }
88.     currtime++;        
89.    }
90. printf("\n-------------------------------------------------------");
91. printf("\nNumber of Page Faults=%d",page_fault);
92. }