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Sync with 5.3-RELEASE.

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PR:		docs/73429
Submitted by:	Joel Dahl <joel at automatvapen dot se>
Reviewed by:	jhb
This commit is contained in:
Ceri Davies 2004-11-08 21:05:23 +00:00
parent 0a2362fd08
commit e3191b439b
Notes: svn2git 2020-12-08 03:00:23 +00:00 
svn path=/head/; revision=22876
1 changed files with 17 additions and 7 deletions
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24
en_US.ISO8859-1/books/handbook/kernelconfig/chapter.sgml
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@ -893,19 +893,28 @@ options AHD_REG_PRETTY_PRINT # Print register bitfields in debug
<programlisting>options ADAPTIVE_GIANT # Giant mutex is adaptive.</programlisting>
<para>This option causes Giant to be included in the set of mutexes
adaptively spun on.</para>
<para>Giant is the name of a mutual exclusion mechanism (a sleep mutex)
that protects a large set of kernel resources. Today, this is an
unacceptable performance bottleneck which is actively being replaced
with locks that protect individual resources. The
<literal>ADAPTIVE_GIANT</literal> option causes Giant to be included
in the set of mutexes adaptively spun on. That is, when a thread
wants to lock the Giant mutex, but it is already locked by a thread
on another CPU, the first thread will keep running and wait for the
lock to be released. Normally, the thread would instead go back to
sleep and wait for its next chance to run. If you are not sure,
leave this in.</para>
<indexterm>
<primary>kernel options</primary>
<secondary>SMP</secondary>
</indexterm>
<programlisting># To make an SMP kernel, the next two are needed
options SMP # Symmetric MultiProcessor Kernel
device apic # I/O APIC</programlisting>
<programlisting>device apic # I/O APIC</programlisting>
<para>The above are both required for SMP support, and can also be
safely enabled on uniprocessor systems.</para>
<para>The apic device enables the use of the I/O APIC for interrupt
delivery. The apic device can be used in both UP and SMP kernels, but
is required for SMP kernels. Add <literal>options SMP</literal> to
include support for multiple processors.</para>
<programlisting>device isa</programlisting>
@ -1026,6 +1035,7 @@ device amr # AMI MegaRAID
device asr # DPT SmartRAID V, VI and Adaptec SCSI RAID
device ciss # Compaq Smart RAID 5*
device dpt # DPT Smartcache III, IV - See NOTES for options
device hptmv # Highpoint RocketRAID 182x
device iir # Intel Integrated RAID
device ips # IBM (Adaptec) ServeRAID
device mly # Mylex AcceleRAID/eXtremeRAID