From owner-freebsd-current@FreeBSD.ORG Wed Sep 3 22:08:04 2008 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 944701065671 for ; Wed, 3 Sep 2008 22:08:04 +0000 (UTC) (envelope-from josh.carroll@gmail.com) Received: from mail-gx0-f17.google.com (mail-gx0-f17.google.com [209.85.217.17]) by mx1.freebsd.org (Postfix) with ESMTP id 3AE8A8FC08 for ; Wed, 3 Sep 2008 22:08:03 +0000 (UTC) (envelope-from josh.carroll@gmail.com) Received: by gxk10 with SMTP id 10so6246393gxk.19 for ; Wed, 03 Sep 2008 15:08:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:reply-to :to:subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=HYfyRgovlM7bZxI0pqttdaMW4ArLlJdWxkmA22TfX8g=; b=QG5RaETddRjm0tsESnxDD9NSlW+afgiXekqWUAWXvzOWiurV1p3qMlsSxb5RB8bmVV V1wveXvaDvvkfSMEx4MoTVaEOpclFzWy+U1CPd0u3z0qoNgjNZoT0KjeaoMlmYMok8PO HFtIdHK5HEL/35rCnsuv26knzaTFJT+Ift9dM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:reply-to:to:subject:cc:in-reply-to :mime-version:content-type:content-transfer-encoding :content-disposition:references; b=PDnqMU+jee+uSajcRcGNG4FKD4SHcvHwCNBj9IpH6PXE/sHvydH0DH4qNyrTA2V8Vu PoFbLQagxcFZ06OaHxrTRrw2UWLPkRgFWtubRzaxgsoIQYABjsprj5jcxZNMu3RFIaY4 rCxIjxzsu/WOHQYp/38GLIG37kQUJ8/uEXy0A= Received: by 10.151.42.21 with SMTP id u21mr3267441ybj.40.1220478395357; Wed, 03 Sep 2008 14:46:35 -0700 (PDT) Received: by 10.150.140.14 with HTTP; Wed, 3 Sep 2008 14:46:35 -0700 (PDT) Message-ID: <8cb6106e0809031446i3e2a47dar385125ecfb0275dc@mail.gmail.com> Date: Wed, 3 Sep 2008 17:46:35 -0400 From: "Josh Carroll" To: "David Malone" In-Reply-To: <20080903204759.GA4898@walton.maths.tcd.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080903034943.GD11548@cicely7.cicely.de> <20080903204759.GA4898@walton.maths.tcd.ie> Cc: Bernd Walter , ticso@cicely.de, freebsd-current@freebsd.org Subject: Re: MTRR fixup? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: josh.carroll@gmail.com List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Sep 2008 22:08:04 -0000 > You may be able to fix this by just using the memcontrol command - > it already lets you program the MTRRs. Hmm, I think this explains why the amount of ACTIVE memory never exceeds 3G on this box with 4G (with very little WIRED when it "stops" at 3G). I'm guessing this means I am affected: 0xd0000000/0x10000000 BIOS uncacheable set-by-firmware active 0xe0000000/0x20000000 BIOS uncacheable set-by-firmware active I wrote a little script to parse the memcontrol output to make it a little easier to digest at a glance. Memory range [a0000 - a4000] : (640 - 656) is uncacheable {16 KB} Memory range [a4000 - a8000] : (656 - 672) is uncacheable {16 KB} Memory range [a8000 - ac000] : (672 - 688) is uncacheable {16 KB} Memory range [ac000 - b0000] : (688 - 704) is uncacheable {16 KB} Memory range [b0000 - b4000] : (704 - 720) is uncacheable {16 KB} Memory range [b4000 - b8000] : (720 - 736) is uncacheable {16 KB} Memory range [b8000 - bc000] : (736 - 752) is uncacheable {16 KB} Memory range [bc000 - c0000] : (752 - 768) is uncacheable {16 KB} Memory range [d0000000 - e0000000] : (3407872 - 3670016) is uncacheable {262144 KB} Memory range [e0000000 - 100000000] : (3670016 - 4194304) is uncacheable {524288 KB} So if I'm understanding this correctly, the top 768 MB of physical memory on this box is uncacheable, but usable for other purposes? I guess I haven't noticed this since FreeBSD does not (apparently?) start caching from the top of memory like Linux does? I'll have to play with memcontrol to see if I can set those two large ranges as cacheable. So this is a BIOS bug? The board in question is an Asus P5K-E with BIOS revision 1102, which uses an Intel P35 chipset. Can someone confirm whether the above assumptions are correct? Thanks, Josh