From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 3 Oct 2002 13:13:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 3 Oct 2002 13:13:24 -0400 Received: from pizda.ninka.net ([216.101.162.242]:17364 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Thu, 3 Oct 2002 13:13:22 -0400 Date: Thu, 03 Oct 2002 10:11:37 -0700 (PDT) Message-Id: <20021003.101137.56158798.davem@redhat.com> To: zaitcev@redhat.com Cc: linux-kernel@vger.kernel.org Subject: Re: virt_to_page(pci_alloc_consistent()) From: "David S. Miller" In-Reply-To: <20021003122509.B8147@devserv.devel.redhat.com> References: <20021003023814.A5856@devserv.devel.redhat.com> <20021003.010344.123986131.davem@redhat.com> <20021003122509.B8147@devserv.devel.redhat.com> X-FalunGong: Information control. X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) 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 From: Pete Zaitcev Date: Thu, 3 Oct 2002 12:25:10 -0400 > Date: Thu, 03 Oct 2002 01:03:44 -0700 (PDT) > From: "David S. Miller" > I think we MUST allow architectures to do what SPARC and ARM > do, there is simply no other way to change the page protections > easily for these kinds of systems. I can fix sparc, dunno about others. Do you have a problem on sparc64? Are you using a huge page to map the kernel? ARM I believe does not have luxury you have. See, some processors are like MIPS and something sort of KSEG0 is used for PAGE_OFFSET mapping of physical pages. So pages with page protections changes must live in some other area of the kernel address space just like vmalloc() to get the different protection bits. I really would like sun4m to use big pages for the PAGE_OFFSET mappings when possible Peter. So I even don't think fixing Sparc the way I know you are likely to is wise.