18

Reading and Writing Assignments, Discussion Topics
COS/ELE 375

for class on Wednesday Nov. 28, 2012


Please read Sections 5.4 and 5.5 of the text.



Please turn in a written response to this question:

1. Exercise 5.10.1, using row b of the table on page 557. We have the usual Mustard vs. Blue conflict here, and so please use the Mustard version of row b, which is:

Your instructor is baffled by this sentence: "If pages must be brought in from disk, increment the next largest page number." Here's a translation that makes sense to him: "If a page must be brought in from disk, assign it a physical page number one greater than the largest page number currently used."

Then, be prepared to discuss the following in class:

2. If we use the word cache in its generic sense, we can think of physical memory as a cache of recently-used virtual memory pages. We can further think of a TLB as a cache of virtual-to-physical address translations. We will explore these analogies in some detail, considering how the three types of cache are similar or different along a number of different dimensions, among them: block size, reads versus writes, hit ratio, replacement policy, and how misses are serviced. To prepare for this discussion you might want to make a table of some kind.

3. A miss in physical memory is a page fault. What do you think should happen to the cache and TLB on a page fault?