5. Memory Management

See also

• Video Lecture about Memory Management

The task of the memory manager and memory management is to ensure that all processes are always able to access their memory. To accomplish this task requires careful integration between the computer’s hardware and the operating system. When several processes with dynamic memory needs run on the computer at the same time, it is necessary to reference data with both a logical address and a physical address. The hardware is responsible for translating the logical addresses into physical addresses in real time. While the operating system is responsible to:

1. ensure that the requested data is in physical memory when needed
2. program the hardware to perform the address translations.

Contents:

• 5.1. Memory Management Hardware
  • 5.1.1. Memory Hierarchy
  • 5.1.2. Memory Management Unit
• 5.2. Legacy Memory Management Schemes
  • 5.2.1. Single Contiguous Allocation
  • 5.2.2. Partitioned Allocation
  • 5.2.3. Fragmentation
• 5.3. Paged Memory Management
  • 5.3.1. Using the Page Table
  • 5.3.2. Windows PMT
  • 5.3.3. Linux PMT
• 5.4. Virtual Memory Management
  • 5.4.1. Virtual Memory is not Process Swapping
  • 5.4.2. The Virtual Memory Address Space
  • 5.4.3. Page Faults
  • 5.4.4. Page Replacement Algoritms
  • 5.4.5. Frame Allocation
  • 5.4.6. Segmented Virtual Memory with Demand Paging
• 5.5. Memory Management in Modern Operating Systems