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 August 17, 2013 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 to 1 or 0. 39.Dx Ap s 40default is to enable APIC I/O on real hardware and to disable it in 41virtual machines, as determined by the VMM bit in the CPU features. 42.Sh COMPATIBILITY 43The 44.Nm 45kernel supports motherboards that follow the Intel MP specification, 46version 1.4. 47.Sh SEE ALSO 48.Xr mptable 1 , 49.Xr dmesg 8 50.Sh HISTORY 51The 52.Nm 53kernel's early history is not (properly) recorded. It was developed 54in a separate CVS branch until April 26, 1997, at which point it was 55merged into 3.0-current. By this date 3.0-current had already been 56merged with Lite2 kernel code. 57.Pp 58Starting with 59.Dx 3.3 , 60the kernel has SMP support by default and it is no longer optional. 61.Sh AUTHORS 62.An Steve Passe Aq Mt fsmp@FreeBSD.org 63.Sh BUGS 64That would be a good guess... 65