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.\" $FreeBSD$ 25.\" 26.Dd December 5, 2002 27.Dt SMP 4 28.Os 29.Sh NAME 30.Nm SMP 31.Nd description of the FreeBSD Symmetric MultiProcessor kernel 32.Sh SYNOPSIS 33.Cd options SMP 34.Cd options APIC_IO 35.Sh DESCRIPTION 36The 37.Nm 38kernel implements symmetric multiprocessor support. 39.Sh COMPATIBILITY 40Support for multi-processor systems is present for all supported 41architectures on 42.Fx . 43Currently, this includes alpha, i386, ia64, and sparc64. 44Support is enabled using 45.Cd options SMP . 46On some, but not all platforms, it is permissible to use the SMP 47kernel configuration on non-SMP equipped motherboards. 48.Pp 49For i386 systems, the 50.Nm 51kernel supports motherboards that follow the Intel MP specification, 52version 1.4. 53In addition to 54.Cd options SMP , 55i386 also requires 56.Cd options APIC_IO . 57The 58.Xr mptable 1 59command may be used to view the status of multi-processor support. 60.Sh SEE ALSO 61.Xr mptable 1 , 62.Xr condvar 9 , 63.Xr msleep 9 , 64.Xr mtx_pool 9 , 65.Xr mutex 9 , 66.Xr sema 9 , 67.Xr sx 9 68.Sh HISTORY 69The 70.Nm 71kernel's early history is not (properly) recorded. It was developed 72in a separate CVS branch until April 26, 1997, at which point it was 73merged into 3.0-current. By this date 3.0-current had already been 74merged with Lite2 kernel code. 75.Pp 76.Fx 5.0 77introduced support for a host of new synchronization primitives, and 78a move towards fine-grained kernel locking rather than reliance on 79a Giant kernel lock. 80The SMPng Project relied heavily on the support of BSDi, who provided 81reference source code from the fine-grained SMP implementation found 82in 83.Bsx . 84.Sh AUTHORS 85.An Steve Passe Aq fsmp@FreeBSD.org 86