Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 10 Dec 2001 12:18:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 10 Dec 2001 12:18:01 -0500 Received: from e31.co.us.ibm.com ([32.97.110.129]:31663 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id ; Mon, 10 Dec 2001 12:17:44 -0500 Date: Mon, 10 Dec 2001 09:16:53 -0800 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" To: volodya@mindspring.com, Alan Cox cc: linux-kernel@vger.kernel.org Subject: Re: mm question Message-ID: <2953465770.1007975813@mbligh.des.sequent.com> In-Reply-To: <2953042101.1007975389@mbligh.des.sequent.com> X-Mailer: Mulberry/2.0.8 (Win32) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>> > I was hoping for something more elegant, but I am not adverse to writing >>> > my own get_free_page_from_range(). >>> >>> Thats not a trivial task. >> >> Better than giving up.. Unfortunately looking around in >> linux/Documentation and drivers did not yield much in terms of >> explanation. I know I can use mem_map_reserve to reserve a page but I >> don't know how to get page struct from a physical address nor which lock >> to use when messing with this. > > If you don't have any ISA DMA going on in the system, you might consider > bastardising the ZONE_DMA page range by moving the boundary up to > 64Mb, then fixing the allocator not to fail back ZONE_NORMAL et al > allocations to ZONE_DMA. Thus what was originally ZONE_DMA becomes > a sort of ZONE_NO_DMA. Not in the slightest bit pretty, but it might be easier > to implement. Depends if you ever want it to get back into the main tree, > I guess ;-) Of course, if you just did that, you'd never use the ZONE_DMA memory, so that's pretty pointless ;-) You need to create an alloc call with an *option* to force alloc out of ZONE_NORMAL, not make no fallback the default. M. - 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/