ESE 345 Lecture Notes - Lecture 17: System Call, Protection Ring, Cpu Cache

• School: Stony Brook University
• Department: Electrical Engineering
• Course: ESE 345
• Professor: Mikhail Dorojevets

Document Summary

All programs share one address space: the physical address space. Machine language programs must be aware of the machine organization. No way to prevent a program from accessing any machine resource. Use main memory as a cache for secondary (disk) storage. Managed jointly by cpu hardware and the of. Each gets a private virtual address space (process image) holding its frequently used code and data (including stack) Cpu and of translate virtual addresses to physical addresses. The unit of transfer between main memory and disk. Vm translation miss is called a page fault. Program can be given consistent view of memory, even through physical memory is scrambled. Only the most important part of the program ( working set ) must be in physical memory. Contiguous structures (like stacks) use only as much physical memory as necessary yet will still grow later. Different threads (or processes) protected from each other. Different pages, can be given special behavior.