From owner-freebsd-questions@FreeBSD.ORG Thu Jan 15 20:19:17 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4D598106566B for ; Thu, 15 Jan 2009 20:19:17 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from mail-out3.apple.com (mail-out3.apple.com [17.254.13.22]) by mx1.freebsd.org (Postfix) with ESMTP id 309578FC13 for ; Thu, 15 Jan 2009 20:19:16 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from relay11.apple.com (relay11.apple.com [17.128.113.48]) by mail-out3.apple.com (Postfix) with ESMTP id E77484C8EB6E; Thu, 15 Jan 2009 12:19:16 -0800 (PST) Received: from relay11.apple.com (unknown [127.0.0.1]) by relay11.apple.com (Symantec Brightmail Gateway) with ESMTP id CDEA428281; Thu, 15 Jan 2009 12:19:16 -0800 (PST) X-AuditID: 11807130-a788fbb000000fcd-ad-496f9a448f4f Received: from cswiger1.apple.com (cswiger1.apple.com [17.227.140.124]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by relay11.apple.com (Apple SCV relay) with ESMTP id B1B9828245; Thu, 15 Jan 2009 12:19:16 -0800 (PST) Message-Id: <1F87C1DC-A8B3-4FFC-9BA8-AC4F7F38336F@mac.com> From: Chuck Swiger To: Dan Nelson In-Reply-To: <20090115193147.GA61100@dan.emsphone.com> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v930.3) Date: Thu, 15 Jan 2009 12:19:16 -0800 References: <496E06D1.2070706@gmail.com> <20090114181522.GB4487@aurora.oekb.co.at> <20090115193147.GA61100@dan.emsphone.com> X-Mailer: Apple Mail (2.930.3) X-Brightmail-Tracker: AAAAAA== Cc: Michael Powell , freebsd-questions@freebsd.org Subject: Re: kernel configuration X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jan 2009 20:19:17 -0000 On Jan 15, 2009, at 11:31 AM, Dan Nelson wrote: > Actually, those functions are only enabled if the CPU is truly a > 586-class processor. See /sys/i386/isa/npx.c , the npx_attach() > function. There is a test for cpu_class==CPUCLASS_586, while most > modern CPUs are CPUCLASS_686. Thanks for the additional feedback, Dan. I remember some weirdness around things like the VIA C3 "Centaur" processors, which had CMOV feature and claimed to be a 686, but lacked SSE...not that those were an especially common case, but I still have one floating around. I see 686- and SSE2-optimized pagezero routines in support.s, but I don't see equivalents for bzero, bcopy, and copyin/copyout. Is something like generic_bzero() faster on a 686-class CPU than i586_bzero() would be? Regards, -- -Chuck