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Reading and Writing Assignments, Discussion Topics
COS/ELE 375

for class on Wednesday Dec. 8, 2010


Please read sections 5.10, 5.11, and 5.12 of the text.

You have a project milestone due Friday, so no written assignment today.

But nevertheless please do be prepared to discuss the following in class:


Consider the data reference of an unlucky (but legal) load word instruction. How many bad things can happen to it? Missing in the cache is certainly one such thing, as is missing in the TLB. What about the memory reference made by the TLB miss routine to access the Page Table--can it too miss here and there? We will analyze a single load-word instruction whose data reference encounters every possible non-fatal problem the memory system can put in its way, and yet still manages to complete. The fine print: the address is properly aligned; Process page tables reside in the System virtual address space and the System page table lives in un-mapped physical memory (see Elaboration point 5 on page 501); page faults are handled as discussed on pp. 512-514 of the text.

Please think about what all the problems might be and how each one is resolved. You should probably write a list of the problems as part of your preparation.