mlock(2) results in Resource temporarily unavailable on FreeBSD/amd64 9.0-STABLE

[Trond Endrestøl]

I have a system running FreeBSD/amd64 9.0-STABLE as of 
Tue Jan 10 16:22:34 CET 2012.

Every attempt by the root user to use the mlock(2) system call results 
in Resource temporarily unavailable (EAGAIN, 35).

I'm using bash and ulimit -l says there's no restriction on the amount 
of locked memory:

root at hostname:~>ulimit -l
unlimited

Is this typical for the amd64 arch? Is this documented somewhere?
The mlock(2) system call works as expected on the i386 arch.

GnuPG and other software would benefit from a useable mlock(2) on 
the amd64 arch.

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