CSE 131 Lecture Notes - Lecture 14: Inter-Process Communication, Logical Address, Virtual Memory
Document Summary
Midterm is going to be on textbook and slides. Access to registers limited to system mode. Base: start of the process"s memory partition. Logical address: location from the process"s point of view. Physical address = base + logical address. If physical address is greater than base + limit. When a process is running, bring all its data in memory. An idle process sits mostly in disk. Virtual memory: only bring the parts of data that are used for processing and leave the rest in disk. The combination of these two techniques allows more complex memory management schemes. As time progresses, holes will form in memory. Programs may not be able to run even if there is enough memory for them because it is scattered in small holes. The solution is compaction: move all data together. Not efficient because compaction is time consuming. Need to allow for programs to grow. Handled by allocating more space than is necessary at the start.
