精选优质文档-倾情为你奉上CHAPTER 9 Virtual MemoryPractice Exercises9.1 Under what circumstances do page faults occur? Describe the actionstaken by the operating system when a page fault occurs.Answer:A page fault occurs when an access to a page that has not beenbrought into main memory takes place. The operating system veriesthe memory access, aborting the program if it is invalid. If it is valid, afree frame is located and I/O is requested to read the needed page intothe free
