Viewing profile — jonasn

Thanks for the detailed read and the great questions! Regarding the colors and thread counts in Figure 4: the key piece of context here is that the application thread (the Main thr…

That is a creative idea, but unfortunately, Epsilon changes the execution profile too much to act as a clean baseline for barrier costs. One huge issue is spatial locality. Epsilon…

That is spot on. Effectively disabling GC to establish a baseline is exactly the methodology used in the Blackburn & Hosking paper [1] I referenced. In general, for a production JV…

Thanks! It is not currently exposed in JFR for JDK 26, but I agree that it would be the logical next step. Now that the underlying telemetry framework (cpuTimeUsage.hpp) is in plac…

Thanks! I really appreciate that. I spent a lot of time trying to nail the illustrations so I'm really glad it landed well. :-)

Every GC algorithm in HotSpot is designed with a specific set of trade-offs in mind. ZGC and G1 are fantastic engineering achievements for applications that require low latency and…

Great question! I actually just touched on this in another thread that went up right around the same time you asked this. It is clearly the next big frontier! The short answer is: …

Thanks for reading! Your current method, pushing the load until the GC spirals and then comparing the CPU utilization, is exactly the painful, trial-and-error approach I'm hoping t…

Hi HN, I'm the author of this post and a JVM engineer working on OpenJDK. I've spent the last few years researching GC for my PhD and realized that the ecosystem lacked standard to…

Thanks for the kind words and the link :).

You are spot on that the original author had a valid reason: at the time, it was literally the only way to do it. The method in question (Java 1.5) was released in September 2004. …

Author of the OpenJDK patch here. Thanks for the write-up Jaromir :) For those interested, I explored memory overhead when reading /proc—including eBPF profiling and the history be…