Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932336Ab0DGGOc (ORCPT ); Wed, 7 Apr 2010 02:14:32 -0400 Received: from terminus.zytor.com ([198.137.202.10]:54060 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752758Ab0DGGO0 (ORCPT ); Wed, 7 Apr 2010 02:14:26 -0400 Message-ID: <4BBC2086.6090708@zytor.com> Date: Tue, 06 Apr 2010 23:04:54 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.0.4-1.fc12 Thunderbird/3.0.4 MIME-Version: 1.0 To: Venkatram Tummala CC: Chetan Nanda , Joel Fernandes , Frank Hu , hayfeng Lee , linux-kernel@vger.kernel.org, linux-kernel@zh-kernel.org, kernelnewbies@nl.linux.org Subject: Re: why choose 896MB to the start point of ZONE_HIGHMEM References: <4BBB7AC9.5060008@zytor.com> <4BBB8F07.60401@zytor.com> <4BBC1807.1090004@zytor.com> In-Reply-To: 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: 790 Lines: 22 On 04/06/2010 10:57 PM, Venkatram Tummala wrote: > Just a note Chetan. > > We can't exactly say that we require "page table settings" to map that > 896 MB of physical ram. It is an identity mapped segment (1-1 mapping). > So, we dont require the "page tables". Virtual address will be equal to > Physical Address + Page Offset. It is just an addition of offset > No, we still need page tables for the identity-mapped segment. -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/