From owner-cvs-all Fri Jan 24 11:22:31 2003 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B775B37B401 for ; Fri, 24 Jan 2003 11:22:29 -0800 (PST) Received: from mail.speakeasy.net (mail15.speakeasy.net [216.254.0.215]) by mx1.FreeBSD.org (Postfix) with ESMTP id B74D143EB2 for ; Fri, 24 Jan 2003 11:22:28 -0800 (PST) (envelope-from jhb@FreeBSD.org) Received: (qmail 2362 invoked from network); 24 Jan 2003 19:22:33 -0000 Received: from unknown (HELO server.baldwin.cx) ([216.27.160.63]) (envelope-sender ) by mail15.speakeasy.net (qmail-ldap-1.03) with DES-CBC3-SHA encrypted SMTP for ; 24 Jan 2003 19:22:33 -0000 Received: from laptop.baldwin.cx (gw1.twc.weather.com [216.133.140.1]) by server.baldwin.cx (8.12.6/8.12.6) with ESMTP id h0OJMQUT045813; Fri, 24 Jan 2003 14:22:26 -0500 (EST) (envelope-from jhb@FreeBSD.org) Message-ID: X-Mailer: XFMail 1.5.2 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: Fri, 24 Jan 2003 14:22:24 -0500 (EST) From: John Baldwin To: Nate Lawson Subject: Re: cvs commit: src/sys/i386/i386 identcpu.c initcpu.c locore.s Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org, Attila Nagy Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On 24-Jan-2003 Nate Lawson wrote: > On Fri, 24 Jan 2003, Attila Nagy wrote: >> Nate Lawson wrote: >> > The patch merely enables an Auxiliary Processor on equipment that >> > supports HTT. Thus, 4.x still has all its original SMP weaknesses that >> > will lead people (eventually) to 5.x including the fact that only one >> > process can be active in the kernel at a time. >> >> And what about performance? I mean those "Auxiliary Processors" are >> "weaker" than the real ones, so scheduling CPU intensive processes to them >> makes a weird assymmetry. In average for example with a dnetc client >> what's better? :) >> Running two processes with HT turned off, or running four of them with HT >> on? > > I'm not sure what you mean by "weaker". If you have code that is > multi-process and it runs faster on an SMP system than a single CPU > system, then it is likely to run faster with HTT than without. Read the > Intel pages to find more about HTT. Maybe. Preliminary buildworld tests on 4.x seem to suggest that HTT is slower than UP, but buildworld is just one application. HTT will probably be optional on stable. On -current we will eventually use ACPI to enumerate CPU's which means that we will respect BIOS settings with regards to whether or not HTT is enabled. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message