FreeBSD 9-STABLE: jail + rctl … what is datasize?

[Hub- FreeBSD]

Eagerly awaiting the %cpu ability that is in 10, I'm starting to play with using this … not so much to deny, but to allow me to more accurately calculate usage … 

when I do an 'rctl -u' for a jail, I see two values:

datasize=11173888
memoryuse=88137728

My question is simple … does memoryuse *include* datasize?  Or is total memory use memoryuse+datasize?

Basically, memoryuse == sum of the RSS column in ps … vmemoryuse is sum of the VSZ … one of them has to include the datasize, but is it VSZ or RSS?

thx