From owner-freebsd-smp@FreeBSD.ORG Mon Dec 1 13:01:09 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 3E06E16A4CE for ; Mon, 1 Dec 2003 13:01:09 -0800 (PST) Received: from mail7.speakeasy.net (mail7.speakeasy.net [216.254.0.207]) by mx1.FreeBSD.org (Postfix) with ESMTP id F0AF443FEA for ; Mon, 1 Dec 2003 13:00:00 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 3057 invoked from network); 1 Dec 2003 21:00:00 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender )encrypted SMTP for ; 1 Dec 2003 21:00:00 -0000 Received: from laptop.baldwin.cx (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.9/8.12.9) with ESMTP id hB1KxuFn095798; Mon, 1 Dec 2003 15:59:57 -0500 (EST) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.4 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: Date: Mon, 01 Dec 2003 15:59:59 -0500 (EST) From: John Baldwin To: Igor Sysoev X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) cc: freebsd-smp@freebsd.org Subject: RE: halting HTT 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: Mon, 01 Dec 2003 21:01:09 -0000 On 01-Dec-2003 Igor Sysoev wrote: > I had noticed that on Nov 11, 2003 in src/sys/i386/i386/mp_machdep.c > HTT CPUs are not halted by default. What is the reason to do it ? > Is it not better to allow logical CPUs to handle interrupts ? HTT CPUs were halted by default because we needed them to always be used to work around other bugs. Since the other bugs are fixed, we no longer need HTT CPUs unless the user wants them. If you disable HT in the BIOS for example, we no longer probe them. Thus, it doesn't make sense to halt the CPUs if the user has explicitly asked for them. > Besides if I try to halting logical CPUs by machdep.hlt_cpus=10 or > machdep.hlt_logical_cpus=1 then computer is partially freezed, i.e > top that running in ssh session could contunue to run but I can not > login to computer anymore. > > I'm using 5.1-CURRENT from 2003.11.28.00.00.00 and > machdep.logical_cpus_mask=10 I do not know why your machine freezes when you halt the logical CPUs. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/