From owner-freebsd-arch@FreeBSD.ORG Fri Mar 19 12:00:04 2010 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8ABB11065675 for ; Fri, 19 Mar 2010 12:00:04 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 54BD08FC25 for ; Fri, 19 Mar 2010 12:00:04 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 046C046B1A; Fri, 19 Mar 2010 08:00:04 -0400 (EDT) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPA id 3B8118A01F; Fri, 19 Mar 2010 08:00:03 -0400 (EDT) From: John Baldwin To: freebsd-arch@freebsd.org, d@delphij.net Date: Fri, 19 Mar 2010 07:51:26 -0400 User-Agent: KMail/1.12.1 (FreeBSD/7.3-CBSD-20100217; KDE/4.3.1; amd64; ; ) References: <4BA2CE17.2050105@delphij.net> In-Reply-To: <4BA2CE17.2050105@delphij.net> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201003190751.26767.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Fri, 19 Mar 2010 08:00:03 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-1.6 required=4.2 tests=AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: Subject: Re: [PATCH] Utilize i686, SSE and MMX by default on FreeBSD/i386 X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Mar 2010 12:00:04 -0000 On Thursday 18 March 2010 9:06:31 pm Xin LI wrote: > Hi, > > I think it doesn't really make sense to by default use MACHINE_CPU=i486 > when the kernel is built with SSE by default today. > > Attached patch uses i686 SSE MMX by default, the user can always change > the default setting by overriding CPUTYPE (they have to do it as SSE is > enabled by default for several years). The kernel is only built with support for userland applications using SSE, it does not _use_ SSE. Similarly, the kernel is built with support for PG_NX provided on 64-bit processors, but it does not do so by failing to support older 32-bit processors. I think this change is premature. Users can already set CPUTYPE in make.conf. Also, most modern x86 server-class machines are 64-bit in which case they would be running FreeBSD/amd64 and using SSE already. -- John Baldwin