From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750795AbWJPOEh (ORCPT ); Mon, 16 Oct 2006 10:04:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750813AbWJPOEh (ORCPT ); Mon, 16 Oct 2006 10:04:37 -0400 Received: from mail.suse.de ([195.135.220.2]:37264 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1750795AbWJPOEh (ORCPT ); Mon, 16 Oct 2006 10:04:37 -0400 To: "bibo,mao" Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] IA32 move PG0 page table within kernel data segment References: <4529E2BE.1060506@intel.com> From: Andi Kleen Date: 16 Oct 2006 16:04:25 +0200 In-Reply-To: <4529E2BE.1060506@intel.com> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "bibo,mao" writes: > Hi, > On i386 kernel image can compile and run at any physical address,kernel > will dynamically establish initial page table at PG0. Currently PG0 address > is adjacent to _end, that is to say PG0 page table is out of kernel data segment. > Some bootloader put initrd image next kernel data segment so that initial > page table will overwrite initrd imagte. This patch modify this and put PG0 > table at BSS segment and free this space later. > This patch limited kernel image size within 64M, it is possible to modify > ld script to remove this limit, but I am not familiar with ld script. > > Any comments is welcome. Looks like a fragile hack. x86-64 has a imho cleaner generic solution in e820_find_area(). I would suggest to port that over. -Andi