qcu

name	qcu
description	examples/qcu 目录的完整生成 skill：经 Cython 桥测 C++ CUDA 后端；含 dev73_5 多重网格性能基准套件（clean/bench/verify/collect/mktable/plots）。

CLAUDE.md — examples/qcu

C++ CUDA backend tests via the Cython bridge. These exercise libqcu.so from Python.

Test Files

File	What it tests
conftest.cuda.py	Basic CUDA availability and context
conftest.mpi.py	MPI grid setup and halo exchange
conftest.wilson.bistabcg.py	Wilson BiStabCG via C++ backend
conftest.wilson.bistabcg.dslash.py	Wilson BiStabCG dslash kernel
conftest.wilson.cg.py	Wilson CG solver
conftest.clover.py	Clover term construction
conftest.clover.bistabcg.py	Clover BiStabCG solver
conftest.clover.bistabcg.dslash.py	Clover BiStabCG dslash
conftest.clover.multigrid.py	Clover multigrid V-cycle solver

Usage

mpirun -np 1 python examples/qcu/conftest.clover.multigrid.py

Output: convergence log → logs/clover_multigrid.log, performance report → logs/clover_multigrid_report.log

Dev73_5 Multigrid Benchmark Suite

Development scripts for the dev73_5 multigrid performance milestone. They benchmark applyCloverMultigridQcu against the Clover BiStabCG reference (applyCloverBistabCgQcu) across precision / lattice / solver-parameter sweeps, and feed logs/dev73_5.* (report, LaTeX tables, PNG figures).

Scripts are archived under examples/qcu/dev73/ (outputs → logs/dev73/):

File	Purpose
dev73/mg_dev73_5_clean.py	Clean, isolated-process timing of a single config (ref/mg interleaved, min+median speedup)
dev73/mg_dev73_5_bench.py	Extended performance benchmark — precision / lattice / solver-parameter sweeps vs BiStabCG
dev73/mg_dev73_5_verify.py	Correctness checks — SU(3) gauge, solution error, null-vector zero-mode/orthogonality, C++ vs Python coarse dslash
dev73/mg_dev73_5_collect.py	Aggregate clean/bench/verify JSON into logs/dev73_5_results.json
dev73/mg_dev73_5_mktable.py	Emit LaTeX table snippets (logs/dev73_5_tbl_*.tex) for dev73_5.tex
dev73/mg_dev73_5_plots.py	Generate convergence / hotspot / speedup / time PNG figures into logs/

Newer dev74 / dev74_1 suites live in examples/qcu/dev74/ (outputs → logs/dev74/); the test11/test12 integration suites live in logs/test11/, logs/test12/ (see the test12 skill).

Dev84 Multigrid 攻坚套件（当前版）

examples/qcu/dev84/main.py — 子命令 run / multi / run_gcr / hotspot（带 --only 门控），产物镜像 out/*.json 与 logs/dev84/；报告 examples/qcu/dev84/dev84_report.md。

结论（16×32×32×48 统一格子）：粗空间 ρ_V=0.9759（连续谱无孤立低模簇），MG>2 目标不可达； 体积标度 1.5× 体量仅 0.421×，「大格子有利」证伪。但净优化使 V100 上 MG 首次稳定超 BiStabCG 1.13–1.16×，自适应校正门控再降 MG_2L −18%。机制：CUDA Graph 段回放（8 迭代/段）、零拷贝标量、守卫标量内核、粗解开销 3246→4ms、V-cycle 156→60ms。

剖析工具边界：nvprof 可用（权威）；torch.profiler/kineto 捕不到跨线程 C++ 内核；nsys 在 WSL2 失效。