SMP(4)

NAME
SMP - description of the Symmetric MultiProcessor kernel

DESCRIPTION
The DragonFly kernel implements symmetric multiprocessor support by default. APIC I/O can be enabled or disabled by setting the hw.ioapic_enable loader tunable to 1 or 0. DragonFly's default is to enable APIC I/O on real hardware and to disable it in virtual machines, as determined by the VMM bit in the CPU features.

COMPATIBILITY
The SMP kernel supports motherboards that follow the Intel MP specification, version 1.4.

SEE ALSO
mptable(1), dmesg(8)

HISTORY
The SMP kernel's early history is not (properly) recorded. It was developed in a separate CVS branch until April 26, 1997, at which point it was merged into 3.0-current. By this date 3.0-current had already been merged with Lite2 kernel code.

Starting with DragonFly 3.3, the kernel has SMP support by default and it is no longer optional.

AUTHORS
Steve Passe <fsmp@FreeBSD.org>

BUGS
That would be a good guess...