Commit 123eeb1c1a904923754ce65148dbef045b56e083 added incremental GC which moved resetting malloc_increase, oldmalloc_increase to before marking. However, during_minor_gc is not set until gc_marks_start. So the value will be from the last GC run, rather than the current one. Before the incremental GC commit, this code was in gc_before_sweep which ran before sweep (after marking) so the value during_minor_gc was correct.
Fix malloc_increase is not correctly calculated
Commit 123eeb1c1a904923754ce65148dbef045b56e083 added incremental GC
which moved resetting malloc_increase, oldmalloc_increase to before
marking. However, during_minor_gc is not set until gc_marks_start. So
the value will be from the last GC run, rather than the current one.
Before the incremental GC commit, this code was in gc_before_sweep
which ran before sweep (after marking) so the value during_minor_gc
was correct.