Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262751AbUCWR5F (ORCPT ); Tue, 23 Mar 2004 12:57:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262750AbUCWR5F (ORCPT ); Tue, 23 Mar 2004 12:57:05 -0500 Received: from hellhawk.shadowen.org ([212.13.208.175]:25607 "EHLO hellhawk.shadowen.org") by vger.kernel.org with ESMTP id S262751AbUCWR47 (ORCPT ); Tue, 23 Mar 2004 12:56:59 -0500 Date: Tue, 23 Mar 2004 17:59:20 +0000 From: Andy Whitcroft To: Russell King , Linus Torvalds cc: Jeff Garzik , David Woodhouse , Christoph Hellwig , William Lee Irwin III , Andrew Morton , Andrea Arcangeli , linux-kernel@vger.kernel.org Subject: Re: can device drivers return non-ram via vm_ops->nopage? Message-ID: <28313883.1080064760@42.150.104.212.access.eclipse.net.uk> In-Reply-To: <20040321235854.H26708@flint.arm.linux.org.uk> References: <1079901914.17681.317.camel@imladris.demon.co.uk> <20040321204931.A11519@infradead.org> <1079902670.17681.324.camel@imladris.demon.co.uk> <20040321222327.D26708@flint.arm.linux.org.uk> <405E1859.5030906@pobox.com> <20040321225117.F26708@flint.arm.linux.org.uk> <405E23A5.7080903@pobox.com> <20040321235854.H26708@flint.arm.linux.org.uk> X-Mailer: Mulberry/3.1.2 (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 Content-Length: 1104 Lines: 26 --On 21 March 2004 23:58 +0000 Russell King wrote: > On Sun, Mar 21, 2004 at 03:51:31PM -0800, Linus Torvalds wrote: >> That might be the minimal fix, since it would basically involve: >> - change whatever offensive "virt_to_page()" calls into >> "dma_map_to_page()". >> - implement "dma_map_to_page()" for all architectures. >> >> Would that make people happy? > > Unfortunately this doesn't make dwmw2 happy - he claims to have machines > which implement dma_alloc_coherent using RAM which doesn't have any > struct page associated with it. Would it not be possible to allocate struct page's for these special areas of memory? Worst, worst, worst case could they not represent pages in a memory only node in the NUMA sense? I am sure there is some way they could be 'tacked' onto the end of the cmap in reality? -apw - 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/