Cache Behavior Analysis Tool

A cache simulator that investigates how prefetching aggressiveness interacts with cache associativity across different memory access patterns.

Research Question

Can next-line prefetching improve cache hit rate beyond spatial/temporal locality, and at what point does prefetch aggressiveness hurt more than it helps?

Overview

This project simulates CPU cache behaviour on real programs. A custom C simulator replays Valgrind memory traces through a configurable L1 cache model, measuring:

• Hit rate across access patterns and cache configurations
• Miss classification (compulsory, conflict, capacity) via a shadow fully-associative cache
• Prefetch usefulness and cache pollution across prefetch distances 0–16

Tech Stack

• C — Cache simulator
• Python (pandas, matplotlib, seaborn) — Analysis and visualisation
• Valgrind Lackey — Memory trace generation
• Docker — Cross-platform reproducibility

Quick Start

With Docker (Works on Mac, Windows, Linux)

Requires Docker Desktop. No other dependencies needed.

git clone <your-repo>
cd cacheSim
docker-compose up

Results and graphs appear in the results/ folder.

Without Docker (Linux only)

Requires gcc, valgrind, python3.

pip install pandas matplotlib seaborn
./run_sim.sh

Configuration

./cache_sim clean_trace.txt -s 4096 -a 1 -b 16 -p 4

Flag	Description	Default
-s	Cache size in bytes	4096
-a	Associativity (1=direct-mapped, N=N-way, 256=fully associative)	1
-b	Block size in bytes	16
-p	Prefetch distance (blocks ahead to speculatively load)	0

Access Patterns

Pattern	Description
Sequential	Linear array traversal
Strided	Every 7th element (stride-7)
Random	Random index access

Output

Running the simulation produces the following in results/:

• results.csv — full data across all 54 configurations
• hitrate_workload.png — hit rate by pattern and associativity
• prefetch_hitrate.png — hit rate vs prefetch distance
• conflict.png — conflict misses by associativity
• prefetch_efficiency.png — prefetch usefulness vs distance
• pollution.png — cache pollution vs distance
• heatmap.png — correlation matrix of cache metrics