PAGE REPLACEMENT ALGORITHM TEAM MEMBERS DARSANA BABU L

PAGE REPLACEMENT ALGORITHM TEAM MEMBERS DARSANA BABU, L. PRIYA CIET

BACKGROUND AND DESCRIPTION OF THE ACHIEVEMENT � When students engage actively with material, they generally understand it better and remember it longer. � All students will actively participate while solving the case studies. � We have formulated case studies for different page replacement algorithm. FIFO, LRU, LFU, ORA

BACKGROUND AND DESCRIPTION OF THE ACHIEVEMENT � Group students into groups with maximum of 5 members � Allocate time for each case studies � There will be multiple way of solution for each question � Analyze all the solution and select best solution � Discuss the multiple solution and point out the reason for selecting the best solution � Encourage students by giving some gifts for the best answer

CASE STUDY � Name of case Study : Operating System � FP Course Linkage : Problem Solving Techniques � Focus Area: Page Replacement Algorithm FIFO, LRU, LFU, ORA

PAGE REPLACEMENT DIAGRAM

QUESTIONS � Consider the following sequences of pages are to be loaded in the memory 1, 1, 5, 4, 3, 5, 2, 4, 1 There are three page frames in a system. Use the different page replacement algorithm to select pages for replacement. Find out the number of page faults in each page replacement algorithm.

PROBLEM STATEMENT � There are twenty balls with 6 different colours Red, Blue, Green, Yellow, Violet, White with shankar. He has a cupboard with 4 racks. He has to arrange the balls in the order VBGVWRBWGVYBY in the cupboard. But the condition is that all the balls in the rack should be different colour.

QUESTION 1 In how many ways it can be arranged and explain each arrangement? 2 Can you relate each of the above arrangement with page replacement algorithm? 3 Calculate the number of pagefault in each of the arrangement?

FIRST METHOD: FIRST IN FIRST OUT V B Y V V B 1 B 2 G V W V V V R R B B B G G G W W 4 5 3 3 R B W G V Y R R B V V G G G Y Y Y W W W B B 5 5 5 6 7 8 8

SECOND METHOD(LEAST RECENTLY USED) � V V B 1 2 B Y G V W R B W G V Y V V V G G G B B B R R V V G G B B Y Y Y W W W W B B 4 5 6 6 10 10 3 3 7 8 9

THIRD METHOD(LEAST FREQUENTLY USED) � V 1 V Y B G B Y V W R B W G V V V V B B R R R G G G G G B B B B W W W Y Y Y 2 3 3 4 5 6 6 7 7 8 8 8

FOURTH METHOD(OPTIMAL REPLACEMENT ALGORITHM) � V 1 V Y B G B Y V W R B W G V V V R R R R B B B G G G G V V W W W Y Y Y 4 5 5 6 7 7 7 2 3 3

HOW TO RELATE � Consider ball as pages , racks as page frame � If page is already loaded in the memory it doesnot have page fault, so no need of replacing the page � Otherwise there happens page fault and there are two cases 1: if there is space in memory new page has to be loaded 2: If there is no space , it should use anyone of the page replacement algorithm to replace the page

QUESTIONS � Consider the following sequences of pages are to be loaded in the memory 1, 1, 5, 4, 3, 5, 2, 4, 1 There are three page frames in a system. Use the different page replacement algorithm to select pages for replacement. Find out the number of page faults in each page replacement algorithm.

FIRST IN FIRST OUT 1 1 5 4 4 1 1 1 3 5 5 5 4 4 3 5 4 1 2 3 4 3 5 3 2 4 5 2 3 2 4 5 3 2 1 6

LEAST RECENTLY USED 1 1 5 4 3 5 2 4 1 1 5 1 5 4 3 5 4 1 1 2 3 4 4 3 5 2 5 4 5 2 6 4 1 2 7

LEAST FREQUENTLY USED 1 1 5 4 3 5 2 4 1 1 5 1 5 4 1 3 5 1 1 2 3 4 5 1 2 5 6 1 4 5 7

OPTIMAL REPLACEMENT ALGORITHM 1 1 5 4 3 5 2 4 1 1 5 1 5 4 3 5 4 1 1 2 3 4 4 3 2 4 5 1 2 4 6

CONCLUSION � The students gave a positive feedback about the usage of this case study that it has cemented the concepts and applications of graph data structures � They also got a chance to experience active learning through problem solving, brainstorming sessions and group presentations � We Embedded the case study feedback sheet used for assessing the students.

FEEDBACK

THANKYOU