"An entire Java heap (large or small) can be marked consistently without falling behind and resorting to long garbage collection pauses because the C4 employs: • Single pass completion to avoid the possibility of applications changing references faster than the mark phase can revisit them • “Self-healing” traps that ensure a finite workload and avoid unnecessary overhead • Parallel marking threads to provide scalability that can support large applications and large dataset sizes"
Maybe I'm looking at the wrong pdf can you provide a source for your claim? It's something useful to know if it's true.