From owner-freebsd-smp@FreeBSD.ORG Tue Oct 10 23:15:24 2006 Return-Path: X-Original-To: freebsd-smp@freebsd.org Delivered-To: freebsd-smp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AB57B16A494 for ; Tue, 10 Oct 2006 23:15:24 +0000 (UTC) (envelope-from joao@matik.com.br) Received: from msrv.matik.com.br (msrv.matik.com.br [200.152.83.14]) by mx1.FreeBSD.org (Postfix) with ESMTP id DA04543DA3 for ; Tue, 10 Oct 2006 23:15:16 +0000 (GMT) (envelope-from joao@matik.com.br) Received: from ap-h.matik.com.br (ap-h.matik.com.br [200.152.83.36]) by msrv.matik.com.br (8.13.8/8.13.1) with ESMTP id k9ANFEEM088215 for ; Tue, 10 Oct 2006 20:15:14 -0300 (BRT) (envelope-from joao@matik.com.br) From: JoaoBR Organization: Infomatik To: freebsd-smp@freebsd.org Date: Tue, 10 Oct 2006 20:15:36 -0300 User-Agent: KMail/1.9.4 References: <20061009114520.1355.qmail@web8608.mail.in.yahoo.com> <200610101555.55558.joao@matik.com.br> <200610101543.29138.jhb@freebsd.org> In-Reply-To: <200610101543.29138.jhb@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200610102015.36589.joao@matik.com.br> X-Virus-Scanned: ClamAV version 0.88.4, clamav-milter version 0.88.4 on msrv.matik.com.br X-Virus-Status: Clean Subject: Re: Hyperthreading Issues (on Athlon64?) X-BeenThere: freebsd-smp@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD SMP implementation group List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Oct 2006 23:15:24 -0000 On Tuesday 10 October 2006 16:43, John Baldwin wrote: > On Tuesday 10 October 2006 14:55, JoaoBR wrote: > > On Tuesday 10 October 2006 15:11, Brooks Davis wrote: > > > > My dmesg does not have the line about "Hyperthreading: 2 logical > > > > CPUs", though. =A0But I had been pretty sure the Athlon64 chips did= n't > > > > have any hyperthreading support. =A0Why is the HTT there? > > > > HTT is NOT hyperthreading, HT is and HT does not exist on AMD64 > > Err, no. =A0The HTT there stands for HyperThreading Technology. you say it right: "stands for" in this case But I think it "is" the other way round, in terms of abreviation: HTT =3D Hyper Transport Technology HT =3D Hyper Threading (Technology) http://download.intel.com/design/Pentium4/manuals/24896613.pdf If believe Intel came up with HyperThreading after AMD brought up the term = HTT=20 and so there was no way to call it HTT but "HT Technology" but this story m= ay=20 be wrong. Unluckily (my opinion) in freebsd's i386 kernel (read NOTES) HT technology = is=20 called HTT CPU.=20 Even if this is certainly ok for whom knows it, then an AMD X2 is definitl= y=20 not a hyperthreaded processor but has 2 cores as well as Intel's newer Core= =20 Duo, so HTT for an AMD X2 would be wrong (my opinion again) on AMD DualCore you see Cores per package: 2 <<<<<<< =46reeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 on P4 HT you see Logical CPUs per core: 2 <<<<<<< ACPI APIC Table: =46reeBSD/SMP: Multiprocessor System Detected: 2 CPUs cpu0 (BSP): APIC ID: 0 cpu1 (AP): APIC ID: 1 what then at the end is correct but it does not correct the logic error : HT or HTT is the question but at the end AMD is not HTT, whatever HT or HTT= =20 then is or stands for =2D-=20 Jo=E3o A mensagem foi scaneada pelo sistema de e-mail e pode ser considerada segura. Service fornecido pelo Datacenter Matik https://datacenter.matik.com.br