`-Xminf` / `-Xmaxf`

Specifies the minimum and maximum proportion of the heap that must remain free after a global garbage collection (GC) cycle.

If the free space is above or below these limits, the Eclipse OpenJ9™ VM attempts to adjust the heap size so that: -Xminf ≤ free space ≤ -Xmaxf.

Syntax

Setting	Effect	Default
`-Xminf<value>`	Set minimum free space	0.3
`-Xmaxf<value>`	Set maximum free space	0.6

The value range is 0.0 - 1.0.

For the balanced GC policy, these values apply only to the non-eden space part of the heap. The non-eden heap resizing decision is made by observing both -Xmint/-Xmaxt and -Xminf/-Xmaxf. Free memory in eden space is not considered for -Xminf/-Xmaxf purposes.
For the gencon GC policy, the values apply only to the tenure part of the heap and only at global GC points.
For the optthruput and optavgpause GC policies, these values apply to the whole heap at every GC point.
This option cannot be used with the metronome GC policy (-Xgcpolicy:metronome) because the heap is always fully expanded.