From owner-freebsd-current@FreeBSD.ORG Mon Nov 22 19:49:24 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 98748106566C; Mon, 22 Nov 2010 19:49:24 +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 6B9CE8FC15; Mon, 22 Nov 2010 19:49:24 +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 2CB9546B09; Mon, 22 Nov 2010 14:49:24 -0500 (EST) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 45CB68A027; Mon, 22 Nov 2010 14:49:23 -0500 (EST) From: John Baldwin To: alc@freebsd.org Date: Mon, 22 Nov 2010 14:47:12 -0500 User-Agent: KMail/1.13.5 (FreeBSD/7.3-CBSD-20101102; KDE/4.4.5; amd64; ; ) References: <1290387926.16558.1283.camel@home-yahoo> <201011220759.16082.jhb@freebsd.org> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201011221447.13026.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (bigwig.baldwin.cx); Mon, 22 Nov 2010 14:49:23 -0500 (EST) X-Virus-Scanned: clamav-milter 0.96.3 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-1.9 required=4.2 tests=BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on bigwig.baldwin.cx Cc: freebsd-current@freebsd.org, Sean Bruno Subject: Re: 40 vs 44 bit memory addressing HP DL580/980 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Nov 2010 19:49:24 -0000 On Monday, November 22, 2010 1:37:45 pm Alan Cox wrote: > On Mon, Nov 22, 2010 at 6:59 AM, John Baldwin wrote: > > > On Sunday, November 21, 2010 8:05:26 pm Sean Bruno wrote: > > > Looks like these HP boxes have the capability to do 44 bit memory > > > addressing if configured to do so from the BIOS. > > > > > > Is anyone interested in any data from that setting? > > > > Does it boot ok? :) The MTRR code should handle that (there is a CPUID > > field that tells the OS how many bits are significant). Not sure if there > > are any places in the pmap that assume 40 bits, but a test boot is > > certainly > > worth trying. > > > > > Since we don't boot with 40-bit addressing, I can easily predict the > outcome. :-) > > The trouble with this machine is that the second 128GB of RAM is being > placed between 512G and 1T in the physical address space, which is beyond > the range of the (current) direct map. So, we take a page fault on the > first access to a page in the second 128GB through the direct map. Heh, I guess that is what your earlier patch did? Once that patch is applied I think Sean should just try 44-bit mode if so. -- John Baldwin