From 680a6bcf2fa63f046bc888a703a5b09a1251413b Mon Sep 17 00:00:00 2001 From: Alexander Motin Date: Sat, 23 Nov 2013 11:46:13 +0000 Subject: [PATCH] MFreleng/8.4 r251256 (by hrs): Update description of logical CPU handling in the latest releases and remove obsolete sysctl variable machdep.hlt_logical_cpus. MFC after: 3 days --- .../doc/en_US.ISO8859-1/hardware/article.xml | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/release/doc/en_US.ISO8859-1/hardware/article.xml b/release/doc/en_US.ISO8859-1/hardware/article.xml index f51738d2e503..6fac85c631d8 100644 --- a/release/doc/en_US.ISO8859-1/hardware/article.xml +++ b/release/doc/en_US.ISO8859-1/hardware/article.xml @@ -177,16 +177,13 @@ bugs may generate some problems. Perusal of the archives of the &a.smp; may yield some clues. - &os; will take advantage of HyperThreading (HTT) support - on &intel; CPUs that support this feature. 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 - machdep.hyperthreading_allowed tunable. + &os; will take advantage of SMT (Symmetric MultiThreading, + also known as HyperThreading on &intel; CPUs) on the supported + CPUs. The GENERIC 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. &os; will take advantage of Physical Address Extensions