From owner-freebsd-smp@FreeBSD.ORG Tue Jun 10 08:00:16 2003 Return-Path: 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 4DEBA37B401; Tue, 10 Jun 2003 08:00:16 -0700 (PDT) Received: from blv-smtpout-01.boeing.com (blv-smtpout-01.boeing.com [130.76.32.69]) by mx1.FreeBSD.org (Postfix) with ESMTP id D888743F93; Tue, 10 Jun 2003 08:00:14 -0700 (PDT) (envelope-from brendon.humphrey@boeing.com) Received: from stl-av-02.boeing.com ([192.76.190.7]) by blv-smtpout-01.boeing.com (8.9.2/8.8.5-M2) with ESMTP id IAA27260; Tue, 10 Jun 2003 08:00:13 -0700 (PDT) Received: from slb-hub-01.boeing.com (localhost [127.0.0.1])KAA16128; Tue, 10 Jun 2003 10:00:12 -0500 (CDT) Received: from XCH-NWBH-01.nw.nos.boeing.com (xch-nwbh-01.nw.nos.boeing.com [192.33.62.231])h5AF00K07898; Tue, 10 Jun 2003 08:00:00 -0700 (PDT) Received: from XCH-NW-28.nw.nos.boeing.com ([192.48.4.102]) by XCH-NWBH-01.nw.nos.boeing.com with Microsoft SMTPSVC(5.0.2195.6662); Tue, 10 Jun 2003 07:58:25 -0700 X-MimeOLE: Produced By Microsoft Exchange V6.0.6375.0 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Date: Tue, 10 Jun 2003 07:58:25 -0700 Message-ID: Thread-Topic: RE: Re: Twin CPU machine running with only one cpu? Thread-Index: AcMvYL06L2QR9VLORL6elxbJixsAtQ== From: "I-Humphrey, Brendon" To: X-OriginalArrivalTime: 10 Jun 2003 14:58:25.0981 (UTC) FILETIME=[BEBB2ED0:01C32F60] cc: freebsd-smp@freebsd.org Subject: RE: Re: Twin CPU machine running with only one cpu? X-BeenThere: freebsd-smp@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: FreeBSD SMP implementation group List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Jun 2003 15:00:16 -0000 All, I'm the originator of the thread, posting from work, using outlook - apologies if this comes out as html!! Anyway, to clarify the machine has two physical CPUs (4 HTT cores), this is shown clearly in the ACPI dump of the processors. Linux sees this machine as a 2 cpu machine (or 4 if the SMP code is initialised explicitly from ACPI). Previous versions of FreeBSD have not identified the HTT cores, rather have picked up the two physical CPUs and run with that. I was around when the machdep.c changes went in (for 4.8) that were supposed to identify HTT cores, but they didn't work on this machine due to the MP Table being a bit strange in the way that it enumerates the cores IIRC. What I am wondering, if subsequent changes to the machdep code have altered the behaviour in such a way that the OS is now picking up the first physical CPU and its HTT core, and ignoring the others. That would account for the weird load/scheduling behaviour. If I have time, I might go wading through the machdep code this evening to see what it does/how it differs from the past... Anyone? Cheers, Brendon