The G1 phase logging is currently rather unstructured. There are two top-levels phases
- Evacuate Collection Set
- Other
where Other is a mix of "unknown time" and misc phases. There are also a blend of various phases at info level such as:
- Merge per-thread states
- Code roots
- Free Collection Set
etc.
Furthermore, some phases are printed in "execution order" and other are just printed at random places.

This should be cleaned up into a coherent format.