From owner-svn-src-releng@FreeBSD.ORG Sun Jun 2 15:47:22 2013 Return-Path: Delivered-To: svn-src-releng@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id D6963EB; Sun, 2 Jun 2013 15:47:22 +0000 (UTC) (envelope-from hrs@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) by mx1.freebsd.org (Postfix) with ESMTP id ABE361E56; Sun, 2 Jun 2013 15:47:22 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.7/8.14.7) with ESMTP id r52FlMLt031768; Sun, 2 Jun 2013 15:47:22 GMT (envelope-from hrs@svn.freebsd.org) Received: (from hrs@localhost) by svn.freebsd.org (8.14.7/8.14.5/Submit) id r52FlM4k031766; Sun, 2 Jun 2013 15:47:22 GMT (envelope-from hrs@svn.freebsd.org) Message-Id: <201306021547.r52FlM4k031766@svn.freebsd.org> From: Hiroki Sato Date: Sun, 2 Jun 2013 15:47:22 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-releng@freebsd.org Subject: svn commit: r251256 - releng/8.4/release/doc/en_US.ISO8859-1/hardware X-SVN-Group: releng MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-releng@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for the release engineering / security commits to the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 02 Jun 2013 15:47:22 -0000 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. - &os; will take advantage of HyperThreading (HTT) support - on &intel; CPUs that support this feature. A kernel with the - options SMP 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 - machdep.hlt_logical_cpus sysctl variable. - It is also possible to halt any CPU in the idle loop with the - machdep.hlt_cpus sysctl variable. The + &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