Memory management in an operating system (OS) is the process of controlling and coordinating computer memory, including assigning portions called blocks to various running programs to optimize overall system performance. The primary objective is to ensure efficient and effective use of memory to support multiple applications running simultaneously without interference.
In a multiprogramming computer, the Operating System resides in a part of memory, and the rest is used by multiple processes. The task of subdividing the memory among different processes is called Memory Management. Memory management is a method in the operating system to manage operations between main memory and disk during process execution. The main aim of memory management is to achieve efficient utilization of memory.
Memory Management techniques:
Fixed Partitioning: Main memory is divided into a number of static partitions at system generation time. A process may be loaded into a partition of equal or greater size. Simple to implement; little operating system overhead. Inefficient use of memory due to internal fragmentation; maximum number of active processes is fixed.
strengths:
Simple to implement; little operating system overhead. Inefficient use of memory due to internal fragmentation; maximum number of active processes is fixed.
weakness:Inefficient use of memory due to internal fragmentation; maximum number of active processes is fixed.
Dynamic Partitioning: Partitions are created dynamically, so that each process is loaded into a partition of exactly the same size as that process
Strenghts: No internal fragmentation; more efficient use of main memory
weakness: Inefficient use of processor due to the need for compaction to counter external fragmentation.
Simple Paging Main memory is divided into a number of equal-size frames. Each process is divided into a number of equal-size pages of the same length as frames. A process is loaded by loading all of its pages into available, not necessarily contiguous, frames.
strength
No external fragmentation
weakness:A small amount of internal fragmentation.
