1. Introduction
Lab #6: Inferring Mystery Cache Geometries
Jason Mars, Ph.D, is trying to reverse engineer a competitor’s microprocessors to discover their cache geometries and has recruited you to help. Instead of running programs on these processors and inferring the cache layout from timing results, you will approximate his work by using a simulator.
2. Instructions
Specifically, each of these “processors” is provided as an object file (.o file) against which you will link your code. See the file mystery-cache.h for documentation of the function interface that these object files export. Your job is to fill in the function stubs in cache-test- skel.c which, when linked with one of these cache object files, will determine and then output the cache size, associativity, and block size. Some of the provided object files are named with this information (e.g. cache_64c_2a_16b.o is a 64 KB capacity, 2-way set-associative cache with 16B blocks) to help you check your work. There are also 3 mystery cache object files, whose parameters you must discover on your own.
You can assume that the mystery caches have sizes that are powers of 2. You cannot assume anything else about the cache parameters except what you can infer from the cache size. Finally, the mystery caches are all pretty realistic in their geometries, so use this fact to sanity check your results.
You will need to complete this assignment on a Linux machine (e.g. on ECI lab computers) with the C standard libraries (e.g. attu). All the files you need are in lab6.zip. To extract the files from this archive, simply use the command:
unzip lab6.zip
and the files will be extracted into a new subdirectory of the current directory named lab6. The provided Makefile includes a target cache-test. To use it, set TEST_CACHE to the object file to link against on the command line – i.e. from within the lab6 directory run the command:
make cache-test TEST_CACHE=cache_64c_2a_16b.o
This will create an executable cache-test that will run your cache-inference code against the
supplied cache object. Run this executable like so:
./cache-test
and it will print the results to the screen.
3. Project Tasks
Complete the 3 functions in cache-test-skel.c which have /* YOUR CODE GOES
HERE*/ comments in them.
Additionally, determine the geometry of each of the three mystery caches and list these in
a comment, along with your name, at the top of your modified cache-test-skel.c. 4. Turn-in
Submit your modified version of cache-test-skel.c to ucsb.ece.154a@gmail.com. The subject needs to be as follows;
5. Acknowledgments
This lab was originally designed by Prof. Luis Ceze.