how to forbid a process to use swap?

[Anton Shterenlikht]

I run a program that uses large arrays.
I don't want it to use swap, because it's
too slow. I want the program to fail when
there's not enough RAM, rather than using
swap. How to do this?

Is it something to do with these kernel
variables:

kern.dfldsiz: 34359738368
kern.dflssiz: 8388608

kern.maxdsiz: 34359738368
kern.maxssiz: 536870912
kern.maxtsiz: 134217728

Many thanks

Anton