Memory Management

aka Warehousing!! Too much stuff ... too little space

• Concerned with organisation of main memory
• Concept of a Memory Hierarchy
• Multiple programs belonging to different users active in memory at the same time - hence need for protection
• Dynamic vs. Static partitioning of memory
• Placement of programs within the available memory, where ? which to move out ?
• Ability to share code and data
• Memory sharing transparent - can't tell if it is shared (illusion of an infinite memory space)

Possible to have multiple levels of caching

  
Figure 1: Memory Hierarchy

• There is never enough memory (RAM or otherwise)
• Parkinson's law : "Programs expand to fill the memory available to hold them"

Idea : Manage the storage available efficiently between the available programs.