CREATE OWN LIBRARY
- 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
Contiguous Memory Allocation
What is contiguous memory allocation:
The main memory must accommodate both the operating system and the various user processes. So, it is important to allocate the main memory inefficient way where the degree of multi-programming will be increased.
The memory is usually divided into two partitions: one for the resident operating system and one for the user processes.
We can place the operating system in either low memory or high memory. The major factor affecting this decision is the location of the interrupt vector. Since the interrupt vector is often in low memory, programmers usually place the operating system in low memory as well. Here we always consider that the operating system resides at low memory.
We usually want several user processes to reside in memory at the same time. We, therefore, need to consider how to allocate available memory to the processes that are in the input queue waiting to be brought into main memory.
# The main concept of the contiguous memory allocation technique is that process is allocated a single contiguous area in memory. One process can be allocated at a particular contiguous space location in memory but not at a different location as part by part.
Still, the process needs a large enough area to accommodate the code, data, stack, and heap area of a process. So, sometimes it is not possible to allocate the process in the contiguous memory location, that’s why external fragmentation and internal fragmentation have occurred.
There are various memory allocation methods. Here explain one early method, contiguous memory allocation.
There are two types of contiguous memory allocation:
1) Fixed partition
2) Dynamic or variable partition
