Memory Management in operating system

The main memory is central to the operation of a modern computer system. Main memory is a large array of bytes, ranging in size from hundreds of thousands to billions. Each byte has its own address. Main memory is a repository of quickly accessible data shared by the CPU and I/O devices.

The central processor reads instructions from main memory during the instruction-fetch cycle and both reads and writes data from main memory during the data-fetch cycle (on a von Neumann architecture).

For example, for the CPU to process data from disk, those data must first be transferred to main memory by CPU-generated I/O calls. In the same way, instructions must be in memory for the CPU to execute them.

The operating system is responsible for the following activities in connection with memory management:

  • Keeping track of which parts of memory are currently being used and who is using them
  • Deciding which processes (or parts of processes) and data to move into and out of memory
  • Allocating and deallocating memory space as needed

Leave a Comment