[HLA91]

Hi all

I am revising for an exam coming up in a module I take called Operating System Concepts, I am looking over a past paper and one question I have spent all day going through Notes, lecture slideshows (useless) and books but I cant understand how to work this out.

Quote

An operating system has three processes running, each requiring 8 pages of virtual memory. Demonstrate by producing a suitable diagram and narrative, how these processes can be supported with a system that contains only 8 frames of main memory.

Its been so long since we covered this topic and the lecturer waffles so much he says one sentence then goes onto talking about what he used to do before becoming a lecturer, wasting out time. Help with this would be very much appreciated.

Thanks

HLA91

[blackcompe]

Firstly, I'd email the professor and ask what exactly he expects in an answer. It sounds like the question is asking for a concise diagram of a virtual memory system. I'd create a diagram with a virtual address space separated into 4KB pages, an MMU enclosing a TLB, a page table (inverted or multi-level), the system RAM with 4KB frames, and the swapfile on disk. For each of those components show the flow on information within the component, and show the flow of information from component to component. It's basically a flow diagram. Wikipedia has great diagrams for virtual memory.