Files
nano-vllm/CLAUDE.md
Zijie Tian e6e0dc5d7d feat: add comprehensive RULER benchmark testing
- Add test_ruler.py from tzj/vs_offload branch with 13 RULER tasks
- Add comprehensive documentation for RULER benchmark results
- Update CLAUDE.md with new documentation index entry
- Add architecture, debugging, optimization, and known issues guides
- Test 32K context with CPU offload: 92.3% accuracy across all tasks
- Parallel execution on 4 GPUs with detailed performance metrics

Benchmark results:
- 13 RULER tasks total (niah_single, multikey, multiquery, multivalue, qa, cwe, fwe, vt)
- 26 samples tested with 92.3% overall accuracy
- CPU offload stable at 32K context length
- Parallel GPU execution achieving 4x speedup

Key findings:
- Single needle tasks: 100% accuracy
- Multi-value and recall tasks: 100% accuracy
- Multi-query tasks: 50% accuracy (most challenging)
- QA tasks: 100% accuracy
- Total execution time: ~220 seconds (parallel)
2026-01-18 20:34:06 +08:00

90 lines
3.7 KiB
Markdown

# CLAUDE.md
This file provides guidance to Claude Code when working with this repository.
## Overview
Nano-vLLM is a lightweight vLLM implementation (~1,200 lines) for fast offline LLM inference. Supports Qwen3 models with CPU offload for long-context inference.
## Documentation Index
| Document | Purpose |
|----------|---------|
| [`docs/architecture_guide.md`](docs/architecture_guide.md) | Core components, CPU offload system design, ring buffer architecture, stream configuration |
| [`docs/sparse_attention_guide.md`](docs/sparse_attention_guide.md) | Block sparse attention methods (XAttention, FlexPrefill, MInference, AvgPool, Quest), computation flow, algorithms |
| [`docs/debugging_guide.md`](docs/debugging_guide.md) | PyTorch hooks for debugging, hook positions, tensor comparison, memory profiling |
| [`docs/optimization_guide.md`](docs/optimization_guide.md) | Performance optimizations: sgDMA (15x), Triton merge (4.3x), N-way pipeline (2x) |
| [`docs/known_issues.md`](docs/known_issues.md) | Documented bugs and fixes: partial last block bug, block size 4096 race condition |
| [`docs/ruler_benchmark_results_32k.md`](docs/ruler_benchmark_results_32k.md) | RULER benchmark results (32K context): 13 tasks, 92.3% accuracy, CPU offload performance |
## GPU Mutex for Multi-Instance Debugging
**IMPORTANT**: When running multiple Claude instances for parallel debugging, different rules apply based on script type:
### Benchmarks (`bench*.py`) - Exclusive GPU Access Required
Before running any `bench*.py` script, Claude MUST wait for exclusive GPU access:
```bash
# Check and wait for GPU to be free
while [ -n "$(nvidia-smi --query-compute-apps=pid --format=csv,noheader)" ]; do
echo "GPU busy, waiting 10s..."
sleep 10
done
```
### Other Scripts (tests, examples) - No Special Requirements
For non-benchmark scripts, exclusive GPU access is NOT required. Multiple nanovllm processes can run simultaneously on different GPUs - each process automatically selects a unique port for `torch.distributed` communication.
## Multi-Instance Development with PYTHONPATH
**IMPORTANT**: When running multiple Claude instances on different worktrees, do NOT use `pip install -e .` globally as it will affect other instances.
**Use PYTHONPATH directly** - no pip install needed:
```bash
# Set PYTHONPATH to point to the project root directory
PYTHONPATH=/path/to/your/worktree:$PYTHONPATH python <script.py>
# Example: running tests
PYTHONPATH=/home/zijie/Code/nano-vllm:$PYTHONPATH python tests/test_needle.py
```
**Benefits**:
- No `pip install` required
- Code changes take effect immediately (no reinstall needed)
- Each worktree is completely isolated
## Configuration
| Parameter | Default | Notes |
|-----------|---------|-------|
| `kvcache_block_size` | 1024 | Tokens per block (4096 now works after race condition fix) |
| `max_num_batched_tokens` | 16384 | Set = max_model_len for long context |
| `gpu_memory_utilization` | 0.9 | GPU memory fraction |
| `enable_cpu_offload` | False | Enable for long context |
| `enforce_eager` | False | Set True to disable CUDA graphs |
## Benchmarking
**Files**: `bench.py` (GPU), `bench_offload.py` (CPU offload), `bench_vllm.py` (comparison)
**Common Issues**:
1. `max_num_batched_tokens < max_model_len`: Set equal for long context
2. CUDA graph dimension mismatch: Ensure `input_len + output_len <= max_model_len`
3. RoPE out of bounds: Check model's `max_position_embeddings` in config.json
**Model Limits**:
- Qwen3-0.6B/4B: 40960 tokens
- Qwen2.5-7B-Instruct-1M: 1048576 tokens
**Performance (Qwen3-0.6B)**:
- GPU: ~18k tok/s (prefill), ~100 tok/s (decode)
- CPU Offload (16K): ~14k tok/s (prefill)
- CPU Offload (32K): ~13k tok/s (prefill)
---
**Author**: Zijie Tian