Compaction of a managed heap is considered a costly operation, and is avoided as much
as possible in commercial runtimes. Instead, partial compaction is often used to defragment
parts of the heap and avoid space blow up. Previous study of compaction limitation provided
some initial asymptotic bounds but no implications for practical systems. In this work, we
extend the theory to obtain better bounds and make them strong enough to become
meaningful for modern systems.

Compaction of a managed heap is a costly operation to be avoided as much as possible in
commercial runtimes. Instead, partial compaction is often used to defragment parts of the
heap and avoid space blowup. Previous study of compaction limitation provided some initial
asymptotic bounds but no implications for practical systems. In this work, we extend the
theory to obtain better bounds and make them strong enough to become meaningful for
modern systems.