Bugzilla

Currently compacting GC runs incremental but compacts a whole zone at a time.  The mutator must not be allowed to observe pointers to the old location of relocated cells, but the updating of those pointers is the longest part of compacting.

One approach for incrementalising this further would be to protect memory pages containing pointers that have not been updated and install a fault handler that updates those pages on demand.  Then we could return to the mutator at any time after the relocation has happened.