Lessons Learned Building High-Performance Rust Profiler

The Rust performance book features over a dozen different profiling tools. So I’m not sure if the world needed a new Rust profiler. Still, I spent the last 6+ months building hotpath-rs. In this post, I’ll describe the design decisions behind the library and share a few performance challenges I encountered while working on it. We’ll go deep into the low-level details: cache-line contention, async futures instrumentation, and decoding raw CPU traces back into Rust symbols. hotpath profiler 101 The next section is a brief overview of the library. Click here if you want to jump straight into the implementation details. Over the last months, the hotpath profiler has grown to over 100k downloads on crates.io and is slowly gaining more adoption in the Rust ecosystem. Before diving into implementation details, let’s quickly look at what hotpath does and why I built it. It’s an “all-in-one” Rust profiler / debugging toolkit designed to quickly identify performance bottlenecks. The core idea…