I wrote this java program for my Operating Systems course (UNM - CS 481). It simulates the behavior of a Memory Management Unit operating under different configurations.
The program is pretty easy to compile and run on any machine with a Java 1.7 compiler.
If you are running on a *nix platform, running the Makefile will produce a .sh script that can be used to run the java program as follows:
./mmu <config file> <trace file>Alternatively, on Windows you can compile with:
mkdir bin
javac -d bin src\mmu\*.java
And run with:
java -cp bin mmu.Main <config file> <trace file>
The config file is a text file with the following format:
physical-memory-size: 4096
frame-size: 1024
memory-latency: 100
page-replacement: RANDOM
tlb-size: 2
tlb-latency: 20
disk-latency: 10
logging-output: off
physical-memory-size: amount of physical memory the simulated machine has, in bytes
frame-size: size of physical frames and virtual pages, in bytes
memory-latency: time, in nanoseconds, to read/write to physical memory
page-replacement: policy the MMU uses to evict frames from physical memory. Available options:
- LRU (Least recently used)
- LFU (Least frequently used)
- MFU (Most frequently used)
- RANDOM
- FIFO (First-in-first-out)
tlb-size: number of entries stored in the translation lookaside buffer. TLB evictions are made based on a LFU policy
tlb-latency: time, in nanoseconds, to read an entry from the TLB
disk-latency: time, in nanoseconds, to read/write to disk
logging-output: "off" or "on". Provides additional details for each entry in the trace file (not recommended for large trace files)
The trace file is a text file with the following format. This file can contain an arbitrary number of memory references. Each reference goes on its own line. Available operations are I, R, and W. I is an instruction fetch, R is a read, and W is a write.
<pid> <operation> <virtual address>
See the /res folder for a sample config file and various trace files.