From owner-freebsd-current@FreeBSD.ORG Tue Nov 16 01:47:22 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 915AB16A4CE for ; Tue, 16 Nov 2004 01:47:22 +0000 (GMT) Received: from digger1.defence.gov.au (digger1.defence.gov.au [203.5.217.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id EC70C43D53 for ; Tue, 16 Nov 2004 01:47:16 +0000 (GMT) (envelope-from wilkinsa@squash.dsto.defence.gov.au) Received: from ednmsw503.dsto.defence.gov.au (ednmsw503.dsto.defence.gov.au [131.185.2.150]) by digger1.defence.gov.au with ESMTP id iAG1kIZg016188 for ; Tue, 16 Nov 2004 12:16:18 +1030 (CST) Received: from muttley.dsto.defence.gov.au (unverified) by ednmsw503.dsto.defence.gov.au (Content Technologies SMTPRS 4.3.10) with ESMTP id for ; Tue, 16 Nov 2004 12:17:10 +1030 Received: from ednex501.dsto.defence.gov.au (ednex501.dsto.defence.gov.au [131.185.2.81]) by muttley.dsto.defence.gov.au (8.11.3/8.11.3) with ESMTP id iAG1eXh30909 for ; Tue, 16 Nov 2004 12:10:33 +1030 (CST) Received: from squash.dsto.defence.gov.au ([131.185.40.212]) by ednex501.dsto.defence.gov.au with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2653.13) id RZJDMXRT; Tue, 16 Nov 2004 12:10:26 +1030 Received: from squash.dsto.defence.gov.au (localhost [127.0.0.1]) by squash.dsto.defence.gov.au (8.12.11/8.12.11) with ESMTP id iAG1fLZW056912 for ; Tue, 16 Nov 2004 12:11:21 +1030 (CST) (envelope-from wilkinsa@squash.dsto.defence.gov.au) Received: (from wilkinsa@localhost) by squash.dsto.defence.gov.au (8.12.11/8.12.11/Submit) id iAG1fLLY056911 for freebsd-current@freebsd.org; Tue, 16 Nov 2004 12:11:21 +1030 (CST) (envelope-from wilkinsa) Date: Tue, 16 Nov 2004 12:11:21 +1030 From: "Wilkinson, Alex" To: freebsd-current@freebsd.org Message-ID: <20041116014121.GJ56252@squash.dsto.defence.gov.au> Mail-Followup-To: freebsd-current@freebsd.org References: <20041115043907.GI51636@squash.dsto.defence.gov.au> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20041115043907.GI51636@squash.dsto.defence.gov.au> User-Agent: Mutt/1.5.6i Subject: Re: Re: Detection of HTT X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Nov 2004 01:47:22 -0000 Is it possible to find out whether HTT is turned on in the BIOS without having to reboot ? acpidump(8) ? It's just that I notice that I have a HTT capable CPU: CPU: Intel(R) Pentium(R) 4 CPU 2.80GHz (2793.19-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0xf29 Stepping = 9 Features=0xbfebfbff And options SMP compiled into the kernel, but lack any message in /var/run/dmesg about HTT being enabled. - aW Wilkinson, Alex wrote: >Why is HTT turned off out of the box ? I thought HTT was meant to be a >hardware 'performance enhancing' feature. > >Why do we disable it ? > > - aW FreeBSD will use HTT if the system has it enabled (usually controlled in the BIOS) and the kernel is compiled for SMP. There are ways to manually disable HTT but leave SMP enabled in the OS, but the default is to use it if the above two requirements are met. However, the OS scheduler is not HTT-aware, so HTT will give a somewhat mixed performance. Scott