From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753269AbXLDL1U (ORCPT ); Tue, 4 Dec 2007 06:27:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752392AbXLDL1L (ORCPT ); Tue, 4 Dec 2007 06:27:11 -0500 Received: from smtp2.linux-foundation.org ([207.189.120.14]:54496 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752068AbXLDL1K (ORCPT ); Tue, 4 Dec 2007 06:27:10 -0500 Date: Tue, 4 Dec 2007 03:26:20 -0800 From: Andrew Morton To: Nick Piggin Cc: Christian Borntraeger , Linux Kernel Mailing List , linux-fsdevel@vger.kernel.org, "Eric W. Biederman" , rob@landley.net, Jens Axboe Subject: Re: [patch] rd: support XIP Message-Id: <20071204032620.aaee039b.akpm@linux-foundation.org> In-Reply-To: <20071204112100.GA20420@wotan.suse.de> References: <20071204042628.GA26636@wotan.suse.de> <200712041054.51599.borntraeger@de.ibm.com> <20071204101009.GB9618@wotan.suse.de> <20071204112100.GA20420@wotan.suse.de> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 4 Dec 2007 12:21:00 +0100 Nick Piggin wrote: > + * > + * Cannot support XIP and highmem, because our ->direct_access > + * routine for XIP must return memory that is always addressable. > + * If XIP was reworked to use pfns and kmap throughout, this > + * restriction might be able to be lifted. > */ > + gfp_flags = GFP_NOIO | __GFP_ZERO; > +#ifndef CONFIG_BLK_DEV_XIP > + gfp_flags |= __GFP_HIGHMEM; > +#endif A dubious tradeoff?