Parallel full-GC employs two bitmaps to track object start and end points. This configuration necessitates a larger memory footprint, with each bitmap consuming approximately 1.5% of the heap size.

Transitioning to the mark-compact algorithm (the same one used in Serial/G1 full-GC) can mitigate the memory footprint and bring it more in line with other garbage collectors.

Under the new algorithm, after marking, three phases ensue: calculating new addresses for objects, forwarding them, and relocating objects to their new addresses.

The relocation phase will largely reuse the logic and implementation from the existing algorithm.