What is the output of
Code:
# sysctl vm.pmap.shpgperproc
# sysctl vm.pmap.pv_entry_max
You could set these to a higher value. There probably are also sysctl variables which tell you how much of these maximum values you are using now.
I don't have access to a FBSD box at the moment so this is all the help I can give you at this moment