Adaptive Threading: The Goldilocks Dilemma with GC Parallelism

Explore the intricacies of garbage collection (GC) parallelism and performance optimization in this technical conference talk from EclipseCon 2022. Dive deep into Eclipse OpenJ9 GC internals, starting with fundamental GC concepts before advancing to complex performance considerations. Learn about Adaptive Threading, an innovative optimization technique for self-tuning parallelism that aims to minimize GC pause times. Understand how GC tasks are parallelized, examine the sometimes counterintuitive effects of parallelism on application performance, and discover the balance between sub-optimal and detrimental parallelism. Follow the development of Adaptive Threading's "goldilocks" approach to finding the optimal thread count through heuristics and dynamic threading models. Gain insights into OpenJ9 GC technology implementation, from simple Stop-The-World collectors to sophisticated pause-less generational policies. Perfect for developers with basic memory management knowledge and GC tuning experience, offering an under-the-hood perspective on VM/GC innovations and their impact on application performance.