Ignoring linux cached data in memory

Is there any way in Hobbit to have the memory graphs *not* include the
memory that Linux is using for cached data?  We have a few machines that
tend to have large portions of their memory being used for the system cache,
and as such, often show 100% swap and physical memory being used, when in
fact there is still free memory.

I would imagine other people have run across this, and I'm curious what has
been done to remedy this.