From owner-freebsd-amd64@FreeBSD.ORG Mon Apr 3 21:37:39 2006 Return-Path: X-Original-To: freebsd-amd64@freebsd.org Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 157DE16A401; Mon, 3 Apr 2006 21:37:39 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.208.78.105]) by mx1.FreeBSD.org (Postfix) with ESMTP id BDDBE43D46; Mon, 3 Apr 2006 21:37:38 +0000 (GMT) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (localhost [127.0.0.1]) by troutmask.apl.washington.edu (8.13.4/8.13.4) with ESMTP id k33Lbcqc099466; Mon, 3 Apr 2006 14:37:38 -0700 (PDT) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.13.4/8.13.1/Submit) id k33Lbcd1099465; Mon, 3 Apr 2006 14:37:38 -0700 (PDT) (envelope-from sgk) Date: Mon, 3 Apr 2006 14:37:38 -0700 From: Steve Kargl To: Mike Jakubik Message-ID: <20060403213738.GA99346@troutmask.apl.washington.edu> References: <44301C6D.3010206@rogers.com> <200604031442.43477.jhb@freebsd.org> <44318E3F.6080808@rogers.com> <20060403211943.GA99241@troutmask.apl.washington.edu> <44319241.7080208@rogers.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <44319241.7080208@rogers.com> User-Agent: Mutt/1.4.2.1i Cc: freebsd-amd64@freebsd.org Subject: Re: Status of NX bit support. X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Apr 2006 21:37:39 -0000 On Mon, Apr 03, 2006 at 05:23:13PM -0400, Mike Jakubik wrote: > Steve Kargl wrote: > >On Mon, Apr 03, 2006 at 05:06:07PM -0400, Mike Jakubik wrote: > > > >>John Baldwin wrote: > >> > >>>On Sunday 02 April 2006 14:48, Mike Jakubik wrote: > >>> > >>>>I was wondering what the status of the NX bit support is. Is the pmap.c > >>>>code still broken or is support enabled and functioning by default? > >>>> > >>>I don't think the status has changed. > >>> > >>Well that sucks.. I guess then there really is no reason for someone to > >>run in amd64 mode unless you need more than 4GB of ram. > >> > > > >You're joking, right? How many registers are available for the > >i386? How many registers are available to an AMD64 cpu in > >64-bit mode? > > > > Yes, but doesn't the software have to be written to take advantage of > these? (What about Intels 64bit extensions, do they have the same extra > registers as the amd cpus?). As far as i can see so far, amd64 mode just > eats more memory. Do you do a large amount of number crunching? AMD paid for work on GCC to optimize gcc's machine description. I've never tried a benchmark of FreeBSD i386 versus FreeBSD amd64 for number crunching. It would be interesting to see a comparison of math/atlas on amd64 hardware under FreeBSD i386 and amd64. Someday, if I have time .... The livermore loops may also be interesting. -- Steve