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- Don't highlight options APIC_IO at the top since it only applies to i386

Browse Source 
and this manpage is somewhat machine independent.
- Don't redundantly say that SMP support is present for all supported
  architectures.  Instead, say that it is present for all Tier-1
  architectures.
- Note that an SMP kernel not booting on a UP machine is an i386-only
  exception.
- Add a paragraph about hyperthreading support including some docco on the
  machdep.hlt_logical_cpus sysctl ps@ recently added.
- Note that SMP support for alpha, ia64, and sparc64 debuted in 5.0.
This commit is contained in:
John Baldwin 2003-04-21 20:05:33 +00:00
parent 666223979c
commit e72380dd09
1 changed files with 15 additions and 3 deletions
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18
share/man/man4/smp.4
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@ -31,20 +31,20 @@
.Nd description of the FreeBSD Symmetric MultiProcessor kernel
.Sh SYNOPSIS
.Cd options SMP
.Cd options APIC_IO
.Sh DESCRIPTION
The
.Nm
kernel implements symmetric multiprocessor support.
.Sh COMPATIBILITY
Support for multi-processor systems is present for all supported
Support for multi-processor systems is present for all Tier-1
architectures on
.Fx .
Currently, this includes alpha, i386, ia64, and sparc64.
Support is enabled using
.Cd options SMP .
On some, but not all platforms, it is permissible to use the SMP
On most platforms it is permissible to use the SMP
kernel configuration on non-SMP equipped motherboards.
The only exception to this rule is the i386 platform.
.Pp
For i386 systems, the
.Nm
@ -57,6 +57,15 @@ i386 also requires
The
.Xr mptable 1
command may be used to view the status of multi-processor support.
.Pp
.Fx
supports hyperthreading on Intel CPU's on the i386 platform.
By default, logical CPUs are not used to execute user processes due to
performance penalties under common loads.
To allow the logical CPUs to execute user processes,
turn off the
.Va machdep.hlt_logical_cpus
sysctl by setting its value to zero.
.Sh SEE ALSO
.Xr mptable 1 ,
.Xr condvar 9 ,
@ -81,5 +90,8 @@ The SMPng Project relied heavily on the support of BSDi, who provided
reference source code from the fine-grained SMP implementation found
in
.Bsx .
.Pp
.Fx 5.0
also introduced support for SMP on the alpha, ia64, and sparc64 architectures.
.Sh AUTHORS
.An Steve Passe Aq fsmp@FreeBSD.org