# Tracy CUDA Graph GPU Zone Repro Demonstrates that unpatched Tracy fails to show GPU zones for kernels launched via CUDA Graphs (`cudaGraphLaunch`). ## Root cause When kernels are launched through CUDA Graphs, CUPTI delivers `CONCURRENT_KERNEL` and `MEMCPY` activity records but no corresponding API callback fires for the individual kernel launches. Tracy's `matchActivityToAPICall()` always fails, and `matchError()` silently drops every GPU zone. ## Build and run ```bash make ./repro ``` ## What to expect | Tracy version | GPU zones shown | |---|---| | Unpatched | 0 | | Patched (cuda-graph-gpu-zones.patch) | ~30 (10 launches x 3 ops) | ## The graph structure Each graph launch contains: 1. `vector_add` kernel (c = a + b) 2. Device-to-device memcpy 3. `vector_add` kernel (c = a + c) The graph is launched 10 times, so 30 GPU operations total.