Memory Allocation Schemes in Operating System

What is the major issue with the Fixed Partitions (equal size Holes) scheme?

What is the total external fragmentation in the Dynamic Partitions scheme?

What is the limitation of the Dynamic Partitions scheme?

What is the solution to the problem of external fragmentation?

What is the characteristic of the Contiguous Allocation scheme?

What is the main difference between the Fixed Partitions (equal size Holes) and Fixed Partitions (unequal size Holes) schemes?

Memory Allocation Schemes

Contiguous Allocation: Allocates a single contiguous block of memory to a process.

Fixed Partitions

Unequal size Holes: Divides memory into fixed partitions of unequal sizes.
Internal Unused Space: Each partition has unused space, leading to internal fragmentation.
Equal size Holes: Divides memory into fixed partitions of equal sizes, also suffers from internal fragmentation.

Dynamic Partitions

External Fragmentation: Memory is divided into variable-sized partitions, leading to external fragmentation.
Example: Total memory = 40 MB, with 5, 7, 10, 12, and 15 MB free partitions, resulting in 32 MB of external fragmentation.
Limitation: Cannot allocate a process size more than 15 MB, due to external fragmentation.
Solution: Compaction and Non-contiguous allocation can solve this problem.

Compaction and Non-contiguous Allocation

Compaction: Moves allocated memory blocks together to create a single large block of free memory.
Non-contiguous Allocation: Allows a process to be allocated non-contiguous blocks of memory, reducing fragmentation.

This quiz focuses on memory allocation schemes, including contiguous allocation and fixed partitions, in operating systems. It covers topics such as process allocation and internal unused space.