At ordinary temperature, matter exists in one of three states Solid- has a shape and forms a surface Liquid- has no shape but forms a surface Gas-has no shape and forms no surface What do we mean by“ fluids”? F| uids are“ substances that flow
❖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
