1.\" Copyright (c) 1997 2.\" Steve Passe <fsmp@FreeBSD.ORG>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. The name of the developer may NOT be used to endorse or promote products 10.\" derived from this software without specific prior written permission. 11.\" 12.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 13.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 14.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 15.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 16.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 17.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 18.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 19.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 20.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 21.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 22.\" SUCH DAMAGE. 23.\" 24.\" $FreeBSD: src/share/man/man4/smp.4,v 1.7.2.4 2001/08/17 13:08:39 ru Exp $ 25.\" 26.Dd October 26, 2012 27.Dt SMP 4 28.Os 29.Sh NAME 30.Nm SMP 31.Nd description of the Symmetric MultiProcessor kernel 32.Sh DESCRIPTION 33The 34.Dx 35kernel implements symmetric multiprocessor support by default. 36APIC I/O can be enabled or disabled by setting the 37.Va hw.ioapic_enable 38loader tunable (default is enabled). 39.Sh COMPATIBILITY 40The 41.Nm 42kernel supports motherboards that follow the Intel MP specification, 43version 1.4. 44.Sh SEE ALSO 45.Xr mptable 1 , 46.Xr dmesg 8 47.Sh HISTORY 48The 49.Nm 50kernel's early history is not (properly) recorded. It was developed 51in a separate CVS branch until April 26, 1997, at which point it was 52merged into 3.0-current. By this date 3.0-current had already been 53merged with Lite2 kernel code. 54.Pp 55Starting with 56.Dx 3.3 , 57the kernel has SMP support by default and it is no longer optional. 58.Sh AUTHORS 59.An Steve Passe Aq fsmp@FreeBSD.org 60.Sh BUGS 61That would be a good guess... 62