Adds torch.autocast(fp16) + GradScaler around _train_advantage and
_train_strategy when run.use_amp=true and device=cuda. CPU/non-CUDA
falls back to fp32 no-op. Mitigations:
- scaler.unscale_(optimizer) before grad_clip.
- nonfinite-loss guard skips overflowing batches and counts them.
- diff.float().square() in advantage loss to avoid fp16 overflow.
- strategy mask/log_softmax kept in fp32.
New metrics: amp/grad_scale, amp/nonfinite_loss_count.
Tests: AMP CUDA smoke + CPU fallback in test_deep_cfr_trainer.py.
Bench: scripts/bench_amp_trainer.py micro-benches train phases under
synthetic replay memory. smoke.yaml result is fp32 3.22ms / AMP 3.92ms
(0.82×, regression). 100-iter A/B on default.yaml deliberately
skipped: smoke regression mirrors the 2026-05-07 torch.compile
regression dynamic (dispatch overhead > kernel benefit at this model
size) and re-confirming on the same size adds no information.
Default stays run.use_amp: false. Re-enable trigger documented in
docs/performance.md: hidden_size >= 1024 or num_layers >= 6, then run
the bench script + 100-iter A/B before flipping default.
The experiment finds a model size where (a) learning-curve gains
justify compute, and (b) forward time is large enough to amortize
AMP/compile/TensorRT overhead. Outcome gates re-enabling those four
deferred optimizations and Option A.
Tested grid: hidden={512,768,1024,1536} × layers={3,4,6,8} subset.
200 iterations per config on home (RTX 3090), single seed initially,
second seed for boundary configs. Eval cadence held at default.
Decision tree included for: success → recommend new default and
trigger downstream plans; null → document and stay; expensive-but-
better → defer until AMP/compile/TRT land.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
performance.md additions:
- Batched Traversal Inference design decision (A vs B vs C with
rationale).
- Option A bench result and structural ceiling (realized batch ~7.2,
IPC overhead exceeds GPU gain at small model size).
- Post-A optimization calculus: why compile/TensorRT remain
iter-neutral today and become meaningful only after model growth
and/or denser eval. Sequencing matters; do not retest these on the
current small model.
- Free-threaded Python (3.13t/3.14t) note: cleanest endpoint in
principle, but PyTorch maturity + Cython nogil audit cost block
near-term adoption.
docs/plans/ (4 plan documents for Codex execution):
- batched_traversal_inference_server.md (executed; deferred).
- amp_trainer.md.
- torch_compile.md.
- cython_safe_heuristic_bots.md (executed; first-pass landed).
docs/reports/ (3 cost reports):
- cost_pytorch_free_threaded_2026-05-07.md: WAIT 3-6 months;
PyTorch wheels exist but our Cython is the gating cost.
- cost_cython_nogil_audit_2026-05-07.md: medium effort, traversal.pyx
carries 90% of blockers; Steps 1-3 (cfr_math/encoding nogil
keywords, TraversalStats cdef class) are safe and cheap, Steps
4-6 wait for triggers.
- cost_pytorch_cuda_multithread_2026-05-07.md: risky;
optimizer.step / load_state_dict race silently with concurrent
forward; per-thread default streams unset means naive threading
serializes on default stream anyway.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Measured DeepCFRMLP forward at bs={1,4,16,64,256,1024} on RTX 3090.
Per-state cost drops 232× from bs=1 (80 µs) to bs=256 (0.34 µs) while
per-call latency stays near 90 µs through bs=256. Policy-call supply
from a real run is ~368 states per traversal and ~200k per iteration,
well above the bs=64–256 plateau, so batched inference is not
supply-limited. GPU forward is not the limiter once batching exists.
Verdict: Optimization Priorities #5 (batched traversal inference) is
worth pursuing. End-to-end gain will still be bounded by encoding and
worker-GPU coordination overhead.
- scripts/profile_gpu_forward.py: standalone profiling script
- docs/performance.md: new "GPU forward profiling for batched traversal"
experiment section with table, supply estimate, and verdict
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Make the link from the failed torch.compile experiment to Optimization
Priorities #5 explicit, so a future revisit happens at the right time
(once compile is on the dominant phase, not just trainer optimization
steps).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Wrapping trainer networks with torch.compile produced a 4.8% regression
in iteration time on default.yaml (17.93s → 18.79s). Two causes: (1)
the dominant phase is CPU traversal which bypasses the compiled
wrapper, (2) DeepCFRMLP is too small for compile dispatch overhead to
pay back. Implementation kept on experiments/torch-compile for future
revisits when the trainer model or inference path changes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
같은 hyperparameter (512x3, 2x updates, argmax_tiebreak)에 opponent_policy
만 self_play_league로 다른 run과의 iteration별 비교 표 추가. iter 350
시점에서 Random WR 38%p 격차 (network 34% vs league 72%) 확인 — 발산
가설을 실증.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
opponent_policy=network 설정으로 1000-iter 실험 두 개 (512x3, 1024x4)를
돌린 결과 두 실험 모두 policy collapse가 발생함을 확인. 큰 capacity는
plateau를 늘리지만 발산 자체를 막지 못함. 향후 학습은 self_play_league
기본값을 유지할 것을 권고.
- 실험에 사용한 config 두 개 추가
- 발견 분석 문서 추가 (원인, 비교, 권고)
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
맥락: 클래식 포트를 Python/Cython 구현과 pygame GUI 중심으로 정리한다.
변경: Rust 크레이트, proto 계약, Rust backend shim, 패리티 테스트를 삭제하고 문서와 backend factory를 Python 전용으로 갱신했다.
확인: uv run pre-commit run --all-files; uv run pytest tests/games/classic; uv run lost-cities-classic-gui --help
맥락:
- GUI 이식 전에 Rust crate와 proto schema 위치를 Python package 내부에서 분리한다.
- Cargo 작업, IDE 인식, 빌드 산출물 관리를 루트 구조에 맞춘다.
변경:
- rust_core를 rust/lost-cities-core로 이동하고 proto/lost_cities.proto를 루트 proto 디렉터리로 옮겼다.
- Rust build.rs, Python Rust backend, Rust parity 테스트의 경로를 새 위치로 수정했다.
- Python package-data에서 Rust crate와 proto 항목을 제거하고 README/port notes를 갱신했다.
확인:
- uv sync --extra gui --reinstall-package coolrl-lost-cities
- uv run pytest tests/games/classic
- uv run lost-cities-classic
맥락:
- 새 레포의 첫 범위를 RL 없는 Lost Cities classic 게임 구현으로 잡았다.
- 기존 tier0-3 실험 축은 제거하고 classic 5-expedition 룰을 기본값으로 둔다.
변경:
- games/classic 아래에 Cython 게임 엔진, env, bots, backend 경계, Rust core와 proto schema를 이식했다.
- setuptools/Cython 빌드 설정과 package data, README, classic port notes를 추가했다.
- 룰, 점수, 마스크, env, canonical state, bot, Rust parity 테스트를 새 경로로 가져왔다.
확인:
- uv run pytest tests/games/classic
- uv run lost-cities-classic
coolguy
