FOR FREE CONTENT
- Introduction: OS
- Booting Process
- Command Interpreter
- Dual mode of operation
- System Calls
- Difference between system call and library call
- Interrupt and Trap
- Introduction
- Scheduling Criteria, Terms and Concepts
- Different Type Scheduling Algorithms
- Longest Job First
- Longest Remaining Time First
- Highest Response Ratio Next (HRRN)
- Priority Scheduling
- Least Completed Next (LCN) Scheduling
- Multi-Level Queue Scheduling
- Multilevel Feedback Queue Scheduling
- Guaranteed Scheduling
- Fair Share Scheduling
- Lottery Scheduling
- Multi-Processor Scheduling
- Deadline Scheduling
- Rate-Monotonic Scheduling
- POSIX Real-Time Scheduling
- Priority Inversion
- Proportional Share Scheduling
- Comparison table of Scheduling Algorithm
- Algorithm Evaluation for Scheduling
- Important concept of MM
- Memory Representation as Address
- Memory layout for a Process
- Logical and Physical Address Space
- Necessity of Memory Management
- Introduction
- Concept of Non-contiguous memory allocation
- Basic concept of Paging
- Address Translation
- Process of Paging Method
- Calculation of Offset for paging
- Calculation of Logical Address Bit and number of Pages
- Calculation of Physical Address Bit and number of Frames
- Calculation of Page Table Size
- Organization of MMU
- Why Page size power of 2
- Paging Address Calculation: example1
- Paging Numeric Problem: Example2
- Paging Address Calculation: Example3
- Paging Address Calculation: Question1
- Some Important Question 2
- Paging Address Translation: Question3
- UGC NET Paging Question
- GATE Paging Question
- Number of information at Page Entry
- Exams Question on Page Entry Information
- Exam Question: Page Entry Information
- Calculates Page Table Entry Size
- Calculates Page Size
- Calculation of Optimal Page Size
- Question on Optimal Page Size
- Hashed Page Table with Example
- Inverted Page Table with Gate Question
- Question on Inverted Page Table
- Multi-Level Paging
- Multi-level paging: Example1
- Multi-level paging: Example2
- Allocation of Frames
- Subject Mock
NET Question: FIFO page replacement algorithm
Page references A B A C A B D B A C D. Two frames are there. Find page faults using FIFO and LRU, page replacement algorithm page faults are.
(a) 9 and 7
(b) 7 and 6
(c) 9 and 8
(d) 8 and 6
Solution:
They are asking page fault for FIFO and LRU.
You should know:
Least Recently Used (LRU) algorithm, GATE question on LRU, FIFO page replacement algorithm, GATE on FIFO page replacement algorithm
First we calculate page faults for FIFO:
Page References: A B A C A B D B A C D. Number of frames in main memory is 2.
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So, the number of page faults = 9.
Shortcut method:
But in examination it is not possible to solve it by this elaborative way we can do it by a single frame like below:
Page references: A B A C A B D B A C D and 2 frames.
.png)
Number of page faults= 9.
Now we calculate page fault using LRU policy:
Before seeing the solution please follow previous chapters:
Least Recently Used (LRU) algorithm, GATE question on LRU
Page References: A B A C A B D B A C D and 2 frames.
.png)
So, the number of page faults = 8.
Shortcut method:
But in examination it is not possible to solve it by this elaborative way we can do it by a single frame like below:
Page references: A B A C A B D B A C D and 2 frames.
.png)
Number of page faults= 8.
Final answer:
Number of page faults using FIFO policy = 9
Number of page faults using LRU policy = 8
So, option (C) is correct.
