Modern JVMs have a GC that has O(1) pause times, often of less than 1msec regardless of heap size. In ZGC and Shenandoah, GC is fully concurrent and pauses are

Modern JVMs have a GC that has O(1) pause times, often of less than 1msec regardless of heap size. In ZGC and Shenandoah, GC is fully concurrent and pauses are basically imperceptible. Even walking the stacks to locate pointers into the heap is done whilst the application is still running.