20 votes 20 votes In which one of the following page replacement policies, Belady's anomaly may occur? FIFO Optimal LRU MRU Operating System gatecse-2009 operating-system page-replacement normal isro2016 + – Kathleen asked Sep 22, 2014 • edited Nov 6, 2017 by Manu Thakur Kathleen 8.8k views answer comment Share Follow See all 2 Comments See all 2 2 Comments reply Mitali gupta commented Aug 30, 2020 reply Follow Share Consider the following reference string: 1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5 Case-1: If the system has 3 frames, the given reference string on using FIFO page replacement algorithm yields a total of 9 page faults. The diagram below illustrates the pattern of the page faults occurring in the example. Case-2: If the system has 4 frames, the given reference string on using FIFO page replacement algorithm yields a total of 10 page faults. The diagram below illustrates the pattern of the page faults occurring in the example. It can be seen from the above example that on increasing the number of frames while using the FIFO page replacement algorithm, the number of page faults increased from 9 to 10. Source : https://www.geeksforgeeks.org/beladys-anomaly-in-page-replacement-algorithms/ 2 votes 2 votes PSDesai09 commented Jan 8, 2021 reply Follow Share A.FIFO : Bélády’s anomaly is the name given to the phenomenon where increasing the number of page frames results in an increase in the number of page faults for a given memory access pattern. 0 votes 0 votes Please log in or register to add a comment.
Best answer 11 votes 11 votes Answer : A) FIFO How/Why? Page Replacement algorithms suffer from Belady’s anamoly if : They do not follow the stack based algorithm. Reference :- https://stackoverflow.com/questions/5263988/why-lru-doesnt-suffer-beladys-anomaly https://stackoverflow.com/questions/31801098/how-can-beladys-anamoly-be-avoided Since MRU, LRU & Optimal Replacement Algo follow Stack Algo, hence they are not affected by Belady's Anamoly. SiddharthMahapatra answered Sep 6, 2017 • selected Aug 15, 2022 by Arjun SiddharthMahapatra comment Share Follow See all 0 reply Please log in or register to add a comment.
17 votes 17 votes It is (A). http://en.wikipedia.org/wiki/B%C3%A9l%C3%A1dy%27s_anomaly Gate Keeda answered Jan 10, 2015 • edited Jun 28, 2018 by kenzou Gate Keeda comment Share Follow See all 0 reply Please log in or register to add a comment.
7 votes 7 votes In computer storage, Bélády's anomaly is the phenomenon in which increasing the number of page frames results in an increase in the number of page faults for certain memory access patterns. This phenomenon is commonly experienced when using the First in First Out (FIFO) page replacement algorithm. So, ans is (A)FIFO Warrior answered May 3, 2017 Warrior comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Option:( A) FIFO Belady's anomaly is the problem which occur when we increase the frame size and still the page fault increases Shagun Singh answered Sep 4, 2019 Shagun Singh comment Share Follow See all 0 reply Please log in or register to add a comment.