svn commit: r251256 - releng/8.4/release/doc/en_US.ISO8859-1/hardware

[Hiroki Sato]

Author: hrs
Date: Sun Jun  2 15:47:22 2013
New Revision: 251256
URL: http://svnweb.freebsd.org/changeset/base/251256

Log:
  Update description of logical CPU handling in the latest releases and
  remove obsolete sysctl variable machdep.hlt_logical_cpus.
  
  Pointed out by:	mav
  Approved by:	re (implicitly)

Modified:
  releng/8.4/release/doc/en_US.ISO8859-1/hardware/article.xml

Modified: releng/8.4/release/doc/en_US.ISO8859-1/hardware/article.xml
==============================================================================
--- releng/8.4/release/doc/en_US.ISO8859-1/hardware/article.xml	Sun Jun  2 15:36:29 2013	(r251255)
+++ releng/8.4/release/doc/en_US.ISO8859-1/hardware/article.xml	Sun Jun  2 15:47:22 2013	(r251256)
@@ -167,20 +167,13 @@
 	bugs may generate some problems.  Perusal of the archives of
 	the &a.smp; may yield some clues.</para>
 
-      <para>&os; will take advantage of HyperThreading (HTT) support
-	on &intel; CPUs that support this feature.  A kernel with the
-	<literal>options SMP</literal> feature enabled will
-	automatically detect the additional logical processors.  The
-	default &os; scheduler treats the logical processors the same
-	as additional physical processors; in other words, no attempt
-	is made to optimize scheduling decisions given the shared
-	resources between logical processors within the same CPU.
-	Because this naive scheduling can result in suboptimal
-	performance, under certain circumstances it may be useful to
-	disable the logical processors with the
-	<varname>machdep.hlt_logical_cpus</varname> sysctl variable.
-	It is also possible to halt any CPU in the idle loop with the
-	<varname>machdep.hlt_cpus</varname> sysctl variable.  The
+      <para>&os; will take advantage of SMT (Symmetric MultiThreading,
+	also known as HyperThreading on &intel; CPUs) on the supported
+	CPUs.  The <filename>GENERIC</filename> kernel which is
+	installed by default will automatically detect the additional
+	logical processors.  The default &os; scheduler recognizes
+	processor topology on the system and selects logical and
+	physical processors to obtain optimal performance.  The
 	&man.smp.4; manual page has more details.</para>
 
       <para>&os; will take advantage of Physical Address Extensions