Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262596AbUJ0SpC (ORCPT ); Wed, 27 Oct 2004 14:45:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262538AbUJ0Som (ORCPT ); Wed, 27 Oct 2004 14:44:42 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:46798 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S262618AbUJ0SeF (ORCPT ); Wed, 27 Oct 2004 14:34:05 -0400 Message-ID: <417FEA09.6080502@pobox.com> Date: Wed, 27 Oct 2004 14:33:45 -0400 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.3) Gecko/20040922 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Christoph Hellwig CC: "Martin J. Bligh" , Linux Kernel , linux-mm@kvack.org, Bartlomiej Zolnierkiewicz , "Randy.Dunlap" , William Lee Irwin III , Jens Axboe Subject: Re: news about IDE PIO HIGHMEM bug References: <58cb370e041027074676750027@mail.gmail.com> <417FBB6D.90401@pobox.com> <1246230000.1098892359@[10.10.2.4]> <1246750000.1098892883@[10.10.2.4]> <20041027180816.GA32436@infradead.org> In-Reply-To: <20041027180816.GA32436@infradead.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 910 Lines: 27 Christoph Hellwig wrote: >>To repeat what I said in IRC ... ;-) >> >>Actually, you could check this with the pfns being the same when >> MAX_ORDER-1. >>We should be aligned on a MAX_ORDER boundary, I think. >> >>However, pfn_to_page(page_to_pfn(page) + 1) might be safer. If rather slower. > > > I think this is the wrong level of interface exposed. Just add two hepler > kmap_atomic_sg/kunmap_atomic_sg that gurantee to map/unmap a sg list entry, > even if it's bigger than a page. Why bother mapping anything larger than a page, when none of the users need it? Jeff P.S. In your scheme you would need four helpers; you forgot kmap_sg() and kunmap_sg(). - 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/