Installing the FreeBSD SMP Kernel
- The motherboard must be Intel MP Spec. 1.1 or 1.4 compatible.
- The SMP kernel WILL NOT WORK on a uniprocessor motherboard.
- Be sure to check the Rogue hardware page for
any special configuration options needed for your hardware.
The FreeBSD Symmetric MultiProcessor kernel is now a stardard part of
3.x/4.x/5.0. For the latest kernel config options refer to
src/sys/i386/conf/LINT. There is a ready-made file for creating a generic
SMP kernel: src/sys/i386/conf/SMP-GENERIC.
For general information on building new kernels refer to the
and other documentation.
Currently the permissible options for an SMP kernel include:
# Enables building of a Symmetric MultiProcessor kernel:
# The number of CPUs on the motherboard, defaults to 2:
# The number of busses, defaults to 4:
# The number of IO APICs on the motherboard, defaults to 1.
# The total number of INTs provided by the motherboard, defaults to 24:
You can get a concise list of the appropriate options for your
hardware by running /usr/sbin/mptable on your SMP capable
system. Note that this can be run from a UP (ie non SMP) kernel.
Do 'man mptable' for details.
It is possible to set kern.smp_active to 1 after starting the APs if you want
to throttle down to the main processor.