You don't need stop-the-world pauses for generational GC. As long as your write barrier ensures that pointers to a young object are entirely local to the TLAB t

You don't need stop-the-world pauses for generational GC. As long as your write barrier ensures that pointers to a young object are entirely local to the TLAB that the object is allocated in, you will never need to stop other threads to sweep the nursery.