2026-06-06 –, ZKM Vortragssaal (Lecture Room) Language: English
OpenJDK is the main project behind Java and already has a profiler for performance assessment. But till recently, it wasn't a good one. So four years ago, only weeks into my first job, I decided to change that. But guess what: Getting a big feature into OpenJDK/Java's runtime isn't as easy as I thought.
In this talk, I chronicle my journey of getting a new profiler into JDK 25. It's a tale of blood, sweat, and C++.
Johannes Bechberger is a JVM developer working on profilers and their underlying technology in the SapMachine team at SAP. This includes improvements to async-profiler and its ecosystem, a website to view the different JFR event types, and improvements to the FirefoxProfiler, making it usable in the Java world. His work today comprises many open-source contributions and his blog, where he regularly writes on in-depth profiling and debugging topics. He also works on hello-ebpf, the first eBPF library for Java. His most recent contribution is the new CPU Time Profiler in JDK 25.