Viewing physical memory usage

The number of pages of physical memory on the free list is shown under freemem when using sar -r (or mpsar -r for SMP):

   23:59:44 freemem freeswp
   23:59:49     390   88712
   23:59:54     335   88720
   23:59:59     321   88416
   

   Average      349   88732