From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264322AbTL3CGU (ORCPT ); Mon, 29 Dec 2003 21:06:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264325AbTL3CGU (ORCPT ); Mon, 29 Dec 2003 21:06:20 -0500 Received: from dp.samba.org ([66.70.73.150]:33259 "EHLO lists.samba.org") by vger.kernel.org with ESMTP id S264322AbTL3CGO (ORCPT ); Mon, 29 Dec 2003 21:06:14 -0500 Date: Tue, 30 Dec 2003 13:00:29 +1100 From: Rusty Russell To: William Lee Irwin III Cc: torvalds@osdl.org, mfedyk@matchmail.com, ebiederm@xmission.com, anton@mips.complang.tuwien.ac.at, linux-kernel@vger.kernel.org, phillips@arcor.de Subject: Re: Page Colouring (was: 2.6.0 Huge pages not working as expected) Message-Id: <20031230130029.6183a872.rusty@rustcorp.com.au> In-Reply-To: <20031229102319.GW22443@holomorphy.com> References: <20031228163952.GQ22443@holomorphy.com> <20031229003631.GE1882@matchmail.com> <20031229025507.GT22443@holomorphy.com> <20031229065240.GU22443@holomorphy.com> <20031229092203.GL27687@holomorphy.com> <20031229102319.GW22443@holomorphy.com> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 29 Dec 2003 02:23:19 -0800 William Lee Irwin III wrote: > The fact merely elevating PAGE_SIZE breaks numerous things makes me > rather suspicious of claims that minimalistic patches can do likewise. Can you give an example? One approach is to simply present a larger page size to userspace w/ getpagesize(). This does break ELF programs which have been laid out assuming the old page size (presumably they try to mprotect the read-only sections). On PPC, the ELF ABI already insists on a 64k boundary between such sections, and maybe for others you could simply round appropriately and pray, or do fine-grained protections (ie. on real pagesize) for that one case. Rusty. -- there are those who do and those who hang on and you don't see too many doers quoting their contemporaries. -- Larry McVoy