Yes I am. Java's GC can stop the world at any safepoint. It isn't limited to when objects are allocated and it doesn't do it every time.

I'm aware. A cycle per allocation would be absurdly expensive. "GC every heap allocation" actually means that every heap allocation is subject to garbage collection and has to be traversed on every cycle in which it's reachable. If the GC algorithm uses compaction and/or generations, it gets moved around too. That all has a cost.