Virtual Memory Manager Free list

The VMM maintains a list of free (unallocated) page frames that it uses to satisfy page faults.

AIX tries to use all of RAM all of the time, except for a small amount which it maintains on the free list. To maintain this small amount of unallocated pages the VMM uses page outs and page steals to free up space and reassign those page frames to the free list. The virtual-memory pages whose page frames are to be reassigned are selected using the VMM's page-replacement algorithm.