From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 27 Oct 2004 17:31:11 -0400 From: Jeff Garzik Subject: Re: [PATCH] Re: news about IDE PIO HIGHMEM bug (was: Re: 2.6.9-mm1) Message-ID: <20041027213111.GA13627@havoc.gtf.org> References: <58cb370e041027074676750027@mail.gmail.com> <417FBB6D.90401@pobox.com> <1246230000.1098892359@[10.10.2.4]> <1246750000.1098892883@[10.10.2.4]> <417FCE4E.4080605@pobox.com> <20041027142914.197c72ed.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041027142914.197c72ed.akpm@osdl.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: mbligh@aracnet.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bzolnier@gmail.com, rddunlap@osdl.org, wli@holomorphy.com, axboe@suse.de List-ID: On Wed, Oct 27, 2004 at 02:29:14PM -0700, Andrew Morton wrote: > spose so. The scatterlist API is being a bit silly there. Well, it depends on your perspective :) Each scatterlist entry is supposed to map to a physical segment to be passed to h/w. Hardware S/G tables just want to see a addr/len pair, and don't care about machine page size. scatterlist follows a similar model. dma_map_sg() and other helpers create a favorable situation, where >90% of the drivers don't have to care about the VM-size details. Unfortunately those drivers that need need to do their own data transfer (like ATA's PIO, instead of DMA) need direct access to each member of an s/g list. Jeff -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org