FOR FREE MATERIALS
- 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
GATE question on Working Set Model
GATE: 1992, Q: 12
Let the page reference and the working set window be c c d b c e c e a d and 4, respectively. The initial working set at time t = 0 contains the pages {a,d,e}, where a was referenced at time t = 0, d was referenced at time t = −1, and e was referenced at time t = −2. Determine the total number of page faults and the average number of page frames used by computing the working set at each reference.
Prerequisite:
Before seeing the solution please follow the previous chapter: Working Set Model
Solutions:
The window size of working set = 4
Initial pages in the working set window = {e, d, a}
| Page requested | Time | Working set window | Page fault (Hit/Miss) | Current windows |
| e | -2 | {e} | ----- | Preloaded |
| d | -1 | {d, e} | ----- | Preloaded |
| a | 0 | {a, d, e} | ----- | Preloaded |
| c | 1 | {c, a, d, e} | Page fault | 4 |
| c | 2 | {c, a, d} | No page fault | 3 |
| d | 3 | {d, c, a} | No page fault | 3 |
| b | 4 | {b, d, c} | Page fault | 3 |
| c | 5 | {b, d, c} | No page fault | 3 |
| e | 6 | {e, c, b, d} | Page fault | 4 |
| c | 7 | {c, e, b} | No page fault | 3 |
| e | 8 | {e, c} | No page fault | 2 |
| a | 9 | {a, e, c} | Page fault | 3 |
| d | 10 | {d, a, e, c} | Page fault | 4 |
Number of page faults = 5
Now, we are calculating the average frame requirement
.png)
.png)
