Virtual Memory Overview 1. Background Why need Virtual Memory? Virtual Memory v.s Physical memory Run 一個 program 會發生什麼事？(No Virtual Memory) 2. Demand Paging What is Demand Paging? Demand Paging Performance 3. Process Creation Virtual Memory 如何幫助 process? Copy-on-Write Memory-Mapped File (mmap) 4. Page Replacement Why using Page Replacement? Page Replacement Algorithms 5. Allocation of Frames Introduction Types of allocation 6. Thrashing What is thrashing? Solutions Reviewing question