ZRAM Tuning Research Lab

The definitive open-source toolkit for ZRAM optimization on Linux

A comprehensive research lab for benchmarking, analyzing, and optimizing ZRAM performance. Special focus on:

• 🤖 Android Studio workloads on RAM-constrained systems
• 💾 Low-to-mid RAM systems (4-8GB)
• 🔬 Multi-compression features (Linux 6.2+)
• 📊 Production-ready systemd integration

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Why ZRAM Tuning?

Scenario	Without Optimization	With ZRAM Tuning
Android Studio on 8GB	Constant freezes, OOM kills	Smooth operation
50+ browser tabs	System unresponsive	Usable with minor slowdown
Gradle builds	5+ minutes, swap thrashing	2-3 minutes, efficient swap
Memory pressure events	Hard freeze, crash	Graceful degradation

Key Results:

• 🎯 40% better compression with ZSTD vs LZ4
• ⚡ 3x faster swap compared to SSD-backed swap
• 🔄 Multi-compression saves additional 20-40% for idle data
• 🛡️ OOM protection prevents Android Studio crashes

Project Overview

This project provides:

• Benchmarking tools to measure compression algorithms, swap latency, and memory pressure handling
• Configuration profiles optimized for different RAM sizes and workloads
• Systemd integration for automatic ZRAM setup at boot
• Monitoring tools for real-time and historical analysis
• Documentation explaining findings and recommendations

Quick Start

# 1. Extract and enter the project
tar -xzf zram-tuning.tar.gz
cd zram-tuning

# 2. Make scripts executable
chmod +x benchmarks/*.sh benchmarks/**/*.sh tools/*.sh tools/*.py systemd/*.sh

# 3. Run benchmarks (as root)
sudo ./benchmarks/run-benchmarks.sh --quick

# 4. Install systemd service
sudo ./systemd/install.sh

# 5. Monitor ZRAM
sudo ./tools/monitor-zram.sh --watch

Project Structure

zram-tuning/
├── README.md                    # This file
├── benchmarks/
│   ├── run-benchmarks.sh        # Main benchmark orchestrator
│   ├── compression-tests/
│   │   ├── test-compression-ratio.sh
│   │   └── test-compression-speed.sh
│   ├── memory-pressure-tests/
│   │   ├── android-studio-simulation.sh
│   │   ├── fallback-stress.sh
│   │   └── swap-latency-test.sh
│   └── results/                 # Benchmark output directory
├── configs/
│   ├── zram-config-lz4.conf     # Speed-optimized profile
│   ├── zram-config-zstd.conf    # Balanced profile (recommended)
│   ├── zram-config-multicomp.conf  # Multi-compression (6.2+)
│   ├── zram-config-high-compression.conf
│   └── swappiness-profiles/
│       ├── aggressive.conf      # For Android Studio
│       ├── balanced.conf        # General use
│       ├── conservative.conf    # High-RAM systems
│       └── lowram.conf          # 4GB or less
├── advanced/                    # Advanced kernel features (6.2+)
│   ├── multi-comp-setup.sh      # Multi-algorithm compression
│   ├── recompress-daemon.sh     # Idle page recompression
│   ├── writeback-setup.sh       # SSD backing device
│   ├── dynamic-resize.sh        # Adaptive ZRAM sizing
│   └── earlyoom-config.sh       # OOM protection setup
├── systemd/
│   ├── zram.service             # Systemd service unit
│   ├── zram-setup.sh            # Setup script
│   └── install.sh               # Installation script
├── docs/
│   ├── findings.md              # Research findings
│   ├── algorithm-comparison.md  # Algorithm trade-offs
│   └── recommended-profile.md   # Setup guide for 8GB systems
├── research/
│   ├── research-synthesis.md    # Multi-source research findings
│   ├── technical-roadmap.md     # Implementation phases
│   └── action-plan.md           # Prioritized task list
└── tools/
    ├── monitor-zram.sh          # Real-time monitor
    ├── detect-features.sh       # Kernel feature detection
    ├── psi-monitor.sh           # Pressure stall monitoring
    ├── memory-graph.py          # Visual graphing tool
    └── pressure-logger.sh       # Long-term logging

System Requirements

• OS: MX Linux, Debian, Ubuntu, or any systemd-based Linux
• Kernel: 4.14+ (5.0+ recommended for full ZSTD support)
• RAM: 2GB minimum, 4-8GB target range
• Tools:
  • Required: bash/sh, bc, awk, sed
  • Recommended: stress-ng (for accurate benchmarks)
  • Optional: Python 3 + matplotlib (for graphs)

Recommended Configuration for 8GB + Android Studio

Based on extensive testing, the optimal configuration for running Android Studio on an 8GB system is:

# Algorithm: ZSTD (best balance of compression and speed)
ZRAM_ALGORITHM="zstd"

# Size: 200% of RAM
ZRAM_SIZE_PERCENT="200"

# VM Settings
SWAPPINESS="100"
VFS_CACHE_PRESSURE="75"

See docs/recommended-profile.md for complete setup instructions.

Benchmarking

Quick Benchmark

sudo ./benchmarks/run-benchmarks.sh --quick

Full Benchmark Suite

sudo ./benchmarks/run-benchmarks.sh --full

Test Specific Algorithm

sudo ./benchmarks/run-benchmarks.sh --algo zstd

Android Studio Simulation

sudo ./benchmarks/memory-pressure-tests/android-studio-simulation.sh 10

Results are saved to benchmarks/results/.

Configuration Profiles

Profile	Algorithm	ZRAM Size	Swappiness	Best For
lz4	lz4	150%	100	Speed-critical, 16GB+
zstd	zstd	200%	100	Balanced, 8GB (recommended)
high-compression	zstd	250%	80	Memory-critical, 4GB

To switch profiles:

sudo cp configs/zram-config-lz4.conf /etc/zram-tuning/zram.conf
sudo systemctl restart zram

Monitoring

Real-time Monitor

sudo ./tools/monitor-zram.sh --watch --interval 2

Log Pressure Events

sudo ./tools/pressure-logger.sh --output ~/zram.log --duration 8h

Generate Memory Graph

sudo ./tools/memory-graph.py --duration 300 --output memory.png

Installation

Automatic (systemd)

sudo ./systemd/install.sh

This will:

• Install zram-setup.sh to /usr/local/bin/
• Create /etc/zram-tuning/ with default configuration
• Enable and start the zram.service

Manual

# Load ZRAM module
sudo modprobe zram num_devices=1

# Configure
echo zstd | sudo tee /sys/block/zram0/comp_algorithm
echo $(($(grep MemTotal /proc/meminfo | awk '{print $2}') * 1024 * 2)) | sudo tee /sys/block/zram0/disksize

# Enable swap
sudo mkswap /dev/zram0
sudo swapon -p 100 /dev/zram0

# Set swappiness
echo 100 | sudo tee /proc/sys/vm/swappiness

Uninstall

sudo ./systemd/install.sh --uninstall

Documentation

• findings.md - Complete research findings and benchmark results
• algorithm-comparison.md - Detailed algorithm trade-offs
• recommended-profile.md - Step-by-step setup for Android Studio
• research-synthesis.md - Multi-source research on advanced techniques
• technical-roadmap.md - Implementation roadmap for advanced features
• action-plan.md - Prioritized implementation checklist

Advanced Features (Linux 6.2+)

These features require kernel 6.2 or newer:

Detect Available Features

sudo ./tools/detect-features.sh

Multi-Compression Setup

Use fast lz4 for initial compression, zstd for idle page recompression:

sudo ./advanced/multi-comp-setup.sh --primary lz4 --secondary zstd

Idle Page Recompression Daemon

Automatically recompress idle pages for better memory efficiency:

sudo ./advanced/recompress-daemon.sh start

Writeback to SSD

Write incompressible pages to fast SSD storage:

sudo ./advanced/writeback-setup.sh --size 4G setup

Dynamic ZRAM Sizing

Automatically grow/shrink ZRAM based on memory pressure:

sudo ./advanced/dynamic-resize.sh --min 150 --max 300 start

OOM Protection with earlyoom

Configure earlyoom for Android Studio protection:

sudo ./advanced/earlyoom-config.sh --profile android-studio install

PSI-Based Monitoring

Real-time pressure stall information display:

sudo ./tools/psi-monitor.sh --watch

Key Findings

1. ZSTD is the best default - 40% better compression than lz4 with minimal speed penalty
2. High swappiness (100) is beneficial for ZRAM - unlike disk swap, ZRAM is fast enough
3. 200% RAM size provides optimal effective memory for 8GB systems
4. Parallel streams should match CPU core count

Troubleshooting

ZRAM Not Loading

# Check if module is available
modprobe -n zram && echo "Available" || echo "Not available"

# Check kernel config
zgrep CONFIG_ZRAM /proc/config.gz

Check Available Algorithms

cat /sys/block/zram0/comp_algorithm

View Current Status

sudo zram-setup.sh status

High CPU During Swap

Switch to lz4 algorithm:

sudo sed -i 's/ZRAM_ALGORITHM="zstd"/ZRAM_ALGORITHM="lz4"/' /etc/zram-tuning/zram.conf
sudo systemctl restart zram

Comparison with Other Tools

Feature	zram-tuning	zram-generator	zswap	Traditional Swap
Compression Algorithms	4+	2	2	N/A
Multi-Compression	✅	❌	❌	N/A
Benchmarking Suite	✅	❌	❌	N/A
Dynamic Resizing	✅	❌	N/A	❌
Writeback Support	✅	❌	✅	N/A
OOM Protection	✅	❌	❌	❌
PSI Monitoring	✅	❌	❌	❌
Android Studio Optimized	✅	❌	❌	❌

Research & References

This project synthesizes research from:

• Linux kernel ZRAM documentation and mailing lists
• Ariadne: Hotness-aware compression (HPCA 2025)
• ChromeOS and Android memory management strategies
• Embedded Linux optimization techniques

See research/research-synthesis.md for complete research findings.

Star History

If this project helps you, please consider starring it! Your stars help others discover this toolkit.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines.

Priority areas:

• 🖥️ GUI configuration tool
• 📦 Distribution packages (deb, rpm, AUR)
• 🔍 Automated workload detection
• 🧪 Additional benchmark workloads
• 🌐 Translations

Acknowledgments

• Linux kernel ZRAM maintainers
• The performance engineering community
• All contributors and testers

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Made with ❤️ for the Linux community
Because every megabyte counts