Since JDK-8340426 small pages can reside at high addresses. To avoid fragmentation these pages are defragmented when freed by a GC thread. There is a risk that this will not happen for a long period of time if the page in question is used by the old generation and holds a lot of long lived objects.

It could make sense to add logic to allow such pages to be selected for relocation even if they don't contain a lot of garbage.