❖Why need memory management ❖Memory partitioning ❖Paging ❖Segmentation 3.1 Memory Management Requirements ♣ Relocation(重定位) ♣ Memory Protection(保护) ♣ Memory Sharing(共享) ♣ Logical Organization(逻辑组织) ♣ Physical Organization(物理组织) 3.2 Memory Partitioning • Fixed Partitioning • Dynamic Partitioning • Buddy System(伙伴系统) 3.3 Simple Paging Technique ❖ A process can be loaded into several not continuous frames(页帧). ❖ The efficiency of main memory is higher 3.4 Simple Segmentation Technique • A program and its associated data are divided into a number of segments. The segments may be not the same length. Main memory is divided into many partitions 3.5 Virtual Memory 虚拟存储