Why It Matters
Significant development in Frontier LLMs reported by Reddit LocalLLaMA Community.
Overview
We've been tuning vLLM/SGLang/llama.cpp setups for a long time and got tired of the profiling part: nsys trace, open the GUI, squint, change a flag, repeat. The profilers assume a human is looking at the timeline. These days the thing doing our tuning is usually an agent, and it can't look at a timeline.
Why It Matters
This development was reported by Reddit LocalLLaMA Community.
Key Details
So: https://github.com/graphsignal/graphsignal It's a sidecar profiler.
You wrap whatever you're running: graphsignal-run vllm serve <model> --port 8000 graphsignal-run sglang serve --model-path <model> --port 8000 graphsignal-run ./llama-server -m model.gguf graphsignal-run python whatever.py and it serves everything it measures at http://127.0.0.1:18259/signals as one JSON: time per kernel / per CUDA graph / per memcpy and sync, NVML stuff (util, VRAM, power, clocks, throttling, XID errors), the engine's Prometheus metrics if it has them, and any tracebacks it catches in the console output.
Then you give the agent the SKILL.md from the repo and ask for the outcome ("figure out why my GPU sits at 40% during decode and fix it") and it does the loop: run, load, read, change flag, rerun.
Also works fine with curl and jq if you'd rather be the agent yourself.
A few details: - No code changes, no imports.
--- *Original report published by [Reddit LocalLLaMA (Model Leaks & Local AI)](https://www.reddit.com/r/LocalLLaMA/comments/1wisllu/we_built_an_opensource_gpu_profiler_you_point_an/).*