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
How Non-contiguous Memory Allocation work
Let’s take an example that how non-contiguous memory allocation work, let we have three processes
P1 with size 8KB, P2 with size 16KB, and P3 with size 8KB. Here main memory size is 32KB.
# Every process divided into pages of the same size like 2KB. So, the size of every page is 2KB and the same as each memory frame size is 2KB.
Assume the initial entire memory is free and three processes P1, P2, P3 want to get memory than processes obviously allocate contiguous manner, because not require to allocate as non-contiguous way because memory is free, so, P1, P2, P3 allocate contiguously as memory is entirely free.
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# Now assume that process P2 and P3 has been finished or block (for I/O operation), so, they swap out from memory and create a chance for other processes, assume that process P4 comes with size 14 KB, so,
# P1 individually free 8KB (4 frames) and P3 individually free 8KB (4 frames), but if see above the memory picture 8KB+8KB=16KB (8 frames) will not free contiguously or consecutively.
# So, here because of not enough space to allocate P4 in a place contiguous manner, it allocates two places of memory a non-contiguous manner.
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There are three fundamental approaches to implementing non-contiguous memory allocation:
1. Paging
2. Segment
3. Paging with the segment
