jgrusewski d4624d3534 perf(dqn): eliminate GPU→CPU roundtrips from training hot path
Three optimizations targeting GPU allocation churn and lock contention:

1. In-place polyak update: Var::set() reuses existing GPU buffer instead
   of Var::from_tensor() which allocates a new one per call. Eliminates
   ~10,000 cudaMalloc/cudaFree per epoch (20 params × 500 steps).

2. Fused affine ops: Replace 13 Tensor::full()/Tensor::ones() constant
   tensor allocations per step with tensor.affine(mul, add) — a single
   fused kernel. Patterns: 1-x → x.affine(-1,1), γ*x → x.affine(γ,0),
   0.5*x² → (x*x).affine(0.5,0). Applied across all 4 loss paths
   (branching Bellman/Huber, standard Bellman/Huber, IQN). Eliminates
   ~6,500 GPU allocs/epoch.

3. Batch pre-sampling (K=8): Sample 8 batches under one READ lock, train
   all 8 under one WRITE lock. Reduces async lock acquisitions from
   2×N to 2×ceil(N/8). Priority staleness across 8 steps is negligible.

Combined estimated impact: 20-35% H100 throughput improvement.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-10 19:58:43 +01:00

Foxhunt

Production HFT trading system in Rust.

Architecture

The workspace contains 32 crates organized as follows:

Core Libraries (16)

Crate Purpose
trading_engine Order processing, FIX 4.4, IB TWS, SIMD, RDTSC timing
risk VaR, Kelly, circuit breakers, kill switches, compliance
risk-data Risk data types and shared structures
trading-data Trading data types
ml DQN Rainbow, PPO, TFT, Mamba2, ensemble inference
ml-data ML data types and feature definitions
data Market data ingestion and storage
backtesting Replay engine, strategy tester
adaptive-strategy Ensemble execution, microstructure analysis
common Shared types, resilience, error handling
storage S3 and local model storage
model_loader Model serialization and loading
market-data Market data feed handlers
database PostgreSQL access layer (SQLx)
config Configuration management
tli CLI commands and tooling

Services (8)

Service Purpose
backtesting_service gRPC backtesting service
broker_gateway_service FIX routing, broker connectivity
trading_service Core trading operations
ml_training_service Model training orchestration
data_acquisition_service Market data acquisition
trading_agent_service Autonomous trading agents
api_gateway gRPC API gateway with auth
web-gateway Axum REST + WebSocket gateway

Frontend

web-dashboard/ -- React 19 + TypeScript + Vite + TradingView charts.

Building

# Check compilation (no PostgreSQL required)
SQLX_OFFLINE=true cargo check --workspace

# Run tests for a specific crate
SQLX_OFFLINE=true cargo test -p <crate> --lib

# Clippy
SQLX_OFFLINE=true cargo clippy --workspace

ML Models

Four production model architectures on Candle v0.9.1 with CUDA:

  • DQN Rainbow -- Deep Q-Network with prioritized replay, dueling heads, noisy nets
  • PPO -- Proximal Policy Optimization with GAE and LSTM policies
  • TFT -- Temporal Fusion Transformer for multi-horizon forecasting
  • Mamba2 -- State space model for sequence prediction

Each model has a standalone trainer and a UnifiedTrainable adapter for the hyperopt pipeline.

Infrastructure

  • Git: Gitea at git.fxhnt.ai (Tailscale-only), Scaleway DEV1-S
  • Observability: OpenTelemetry OTLP (env OTEL_EXPORTER_OTLP_ENDPOINT)
  • Database: PostgreSQL with SQLx offline mode for CI

License

Proprietary. All rights reserved.

Description
No description provided
Readme 849 MiB
Languages
Rust 88.2%
Cuda 7.7%
Python 1.3%
Shell 1.1%
PLpgSQL 0.8%
Other 0.8%