From owner-freebsd-questions Tue Jul 2 5:33:48 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3982737B400 for ; Tue, 2 Jul 2002 05:33:44 -0700 (PDT) Received: from web14911.mail.yahoo.com (web14911.mail.yahoo.com [216.136.225.249]) by mx1.FreeBSD.org (Postfix) with SMTP id DB7CC43E13 for ; Tue, 2 Jul 2002 05:33:43 -0700 (PDT) (envelope-from nirv199@yahoo.com) Message-ID: <20020702123343.23356.qmail@web14911.mail.yahoo.com> Received: from [200.192.112.15] by web14911.mail.yahoo.com via HTTP; Tue, 02 Jul 2002 05:33:43 PDT Date: Tue, 2 Jul 2002 05:33:43 -0700 (PDT) From: Paulo Roberto Subject: Re: kernel - pentium FDIV bug corrected? To: Erik Trulsson , Aaron Burke Cc: Paulo Roberto , FreeBSD-Questions In-Reply-To: <20020702061857.GA29547@falcon.midgard.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG --- Erik Trulsson wrote: > On Mon, Jul 01, 2002 at 10:52:53PM -0700, Aaron Burke wrote: > > There is a kernel config option that takes care of it. Also, the > > problem affected more than just the pentium. > > > > But check out /sys/i386/conf/LINT for the "NO_F00F_HACK" option. > > The F00F bug is not the same as the FDIV bug. Also the FDIV bug > affected only the earliest Pentiums (I think it was only the 60 and > 66 > MHz versions) while the F00F bug affected all Pentiums and > Pentium/MMX. Wow. So there is one more bug I was not aware of? Is it also related to math operations? I got a few boxes and I am planning in compiling one kernel for all of them (same sort of hardware). Can I enable this "NO_FOOF_HACK" and use this kernel with a machine that has a cpu that possibly do not have this bug? > One possible workaround could be to use the emulator instead of the > hardware FPU. Check the [GPL_]MATH_EMULATE option and the npx device > in LINT. Note that this will cause all floating point operations to > go > slower so it might not be an acceptable solution. I will try that. > If you really have a machine with the FDIV bug, I would actually > suggest you replace the machine, or at least the CPU. It can't be > that > expensive. The problem is that it would have to change the cpu in seven machines, and probably the motherboards as well. thanks for the help Paulo Roberto __________________________________________________ Do You Yahoo!? Sign up for SBC Yahoo! Dial - First Month Free http://sbc.yahoo.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message