Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752207Ab0G1FyO (ORCPT ); Wed, 28 Jul 2010 01:54:14 -0400 Received: from terminus.zytor.com ([198.137.202.10]:60584 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751297Ab0G1FyM (ORCPT ); Wed, 28 Jul 2010 01:54:12 -0400 Message-ID: <4C4FC5D1.3070708@zytor.com> Date: Tue, 27 Jul 2010 22:53:21 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.7) Gecko/20100720 Fedora/3.1.1-1.fc13 Thunderbird/3.1.1 MIME-Version: 1.0 To: Benjamin Herrenschmidt CC: Yinghai Lu , Ingo Molnar , Thomas Gleixner , Andrew Morton , David Miller , Linus Torvalds , Johannes Weiner , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH 28/31] memblock: Export MEMBLOCK_ERROR again References: <1279822864-17154-1-git-send-email-yinghai@kernel.org> <1279822864-17154-29-git-send-email-yinghai@kernel.org> <1280294128.1970.237.camel@pasglop> <1280294376.1970.239.camel@pasglop> In-Reply-To: <1280294376.1970.239.camel@pasglop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1045 Lines: 27 On 07/27/2010 10:19 PM, Benjamin Herrenschmidt wrote: > > Screw it, I don't like it but I'll just split your patch in two for now > and keep 0. It's a bit fishy but memblock does mostly top-down > allocations and so shouldn't hit 0, and in practice the region at 0 is, > I beleive, reserved, but we need to be extra careful and might need to > revisit that a bit. > > That's an area where I don't completely agree with Linus, ie, 0 is a > perfectly valid physical address for memblock to return :-) > On x86, physical address 0 contains the real-mode IVT and will thus be reserved, at least for the forseeable future. Other architectures may very well have non-special RAM there. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/