From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757374Ab2CFHAh (ORCPT ); Tue, 6 Mar 2012 02:00:37 -0500 Received: from terminus.zytor.com ([198.137.202.10]:36268 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753427Ab2CFHAg (ORCPT ); Tue, 6 Mar 2012 02:00:36 -0500 Message-ID: <4F55B5F7.6060502@zytor.com> Date: Mon, 05 Mar 2012 23:00:07 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120209 Thunderbird/10.0.1 MIME-Version: 1.0 To: Yinghai Lu CC: zhenzhong.duan@oracle.com, Takashi Iwai , Linus Torvalds , "Rafael J. Wysocki" , stable@vger.kernel.org, linux-kernel@vger.kernel.org, konrad.wilk@oracle.com, joe.jin@oracle.com, Thomas Gleixner , Ingo Molnar Subject: Re: [PATCH] Initialize max_pfn_mapped as initial ident mapping size for x86_64 References: <1330669703-20176-1-git-send-email-zhenzhong.duan@oracle.com> <4F556D3D.8040400@zytor.com> In-Reply-To: X-Enigmail-Version: 1.3.5 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 On 03/05/2012 10:27 PM, Yinghai Lu wrote: > >> >> The early mapping range we can fix, and probably should. Mapping the >> first 4 GiB is not a lot of memory and makes a much more sensible >> starting point. > > do you mean map the 4G in head_64.S? > Yes. It would be better to design the mapping system so that it would incrementally map everything we need (with page tables allocated out of the memory already mapped), but that isn't a trivial exercise, especially with the need to avoid the initramfs, kernel image and command line and other data elements. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.