Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

0.1.0 - 2025-01-04

Added

• Core compression library (trueno-zram-core)

  • LZ4 compression with AVX2/AVX-512/NEON acceleration
  • ZSTD compression with SIMD optimization
  • Runtime CPU feature detection and dispatch
  • Same-fill detection for 2048:1 zero page compression

• GPU batch compression

  • CUDA support via cudarc
  • Pure Rust PTX generation via trueno-gpu
  • Warp-cooperative LZ4 kernel (4 warps/block)
  • PCIe 5x rule evaluation
  • Async DMA ring buffer support

• Kernel compatibility

  • Sysfs interface compatible with kernel zram
  • Algorithm compatibility layer
  • Statistics matching kernel format

• Benchmarking utilities

  • Criterion benchmarks
  • Example programs for testing
  • Performance measurement infrastructure

Performance

• LZ4 compression: 4.4 GB/s (AVX-512)
• LZ4 decompression: 5.4 GB/s (AVX-512)
• ZSTD compression: 11.2 GB/s (AVX-512)
• ZSTD decompression: 46 GB/s (AVX-512)
• Same-fill detection: 22 GB/s

Infrastructure

• Published to crates.io as trueno-zram-core
• 461 tests passing
• 94% test coverage
• Full documentation with mdBook

0.2.0 - 2026-01-06

Added

• DT-007: Swap Deadlock Prevention

  • mlock() integration via duende-mlock crate
  • Daemon memory pinning prevents swap deadlock
  • Works in both foreground and background modes

• trueno-ublk daemon

  • ublk-based block device for kernel bypass
  • Hybrid CPU/GPU architecture
  • 12.5 GB/s sequential read (fio verified)
  • 228K IOPS random 4K read

Performance Improvements

• Sequential I/O: 16.5 GB/s (1.8x vs kernel ZRAM)
• Random 4K IOPS: 249K (4.5x vs kernel ZRAM)
• Compression ratio: 3.87x (+55% vs kernel ZRAM)
• CPU parallel decompression: 50+ GB/s

Fixed

• Background mode mlock (DT-007e: mlock called after fork)
• Clippy warnings in GPU batch compression module

[3.17.0] - 2026-01-07

Added

• VIZ-001: TruenoCollector - Renacer visualization integration

  • Implements renacer::Collector trait for metrics collection
  • Feeds throughput, IOPS, tier distribution to visualization framework

• VIZ-002: --visualize flag - Real-time TUI dashboard

  • Tier heatmap, throughput gauge, entropy timeline
  • Requires --foreground mode

• VIZ-003: Benchmark reports - JSON/HTML export

  • trueno-ublk benchmark --format json|html|text
  • trueno-renacer-v1 schema for ML pipelines
  • Self-contained HTML reports with tier distribution charts

• VIZ-004: OTLP integration - Distributed tracing

  • --otlp-endpoint and --otlp-service-name flags
  • Export traces to Jaeger/Tempo

• Release Verification Matrix (docs/release_qa_checklist.md)

  • Falsification-first QA protocol
  • Performance thresholds: >7.2 GB/s zero-page, >550K IOPS

Performance

• ZSTD Recommendation: ZSTD-1 is 3x faster than LZ4 on AVX-512
  • Compress: 15.4 GiB/s (vs 5.2 GiB/s LZ4)
  • Decompress: ~10 GiB/s (vs ~1.5 GiB/s LZ4)
  • Usage: --algorithm zstd

Documentation

• New book chapter: Visualization & Observability
• Updated kernel-zram-parity roadmap (all items COMPLETE)
• New examples:
  • visualization_demo - TruenoCollector metrics demo
  • zstd_vs_lz4 - Algorithm performance comparison
  • tiered_storage - Kernel-cooperative architecture demo

Unreleased

Planned

• trueno-zram-adaptive: ML-driven algorithm selection
• trueno-zram-generator: systemd integration
• trueno-zram-cli: zramctl replacement