Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261926AbUC0Xkr (ORCPT ); Sat, 27 Mar 2004 18:40:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261932AbUC0Xkr (ORCPT ); Sat, 27 Mar 2004 18:40:47 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:36788 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S261926AbUC0Xkk (ORCPT ); Sat, 27 Mar 2004 18:40:40 -0500 Message-ID: <406610EA.4010607@pobox.com> Date: Sat, 27 Mar 2004 18:40:26 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030703 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Bartlomiej Zolnierkiewicz CC: Stefan Smietanowski , linux-ide@vger.kernel.org, Linux Kernel , Andrew Morton Subject: Re: [PATCH] speed up SATA References: <4066021A.20308@pobox.com> <40660877.3090302@stesmi.com> <200403280032.22180.bzolnier@elka.pw.edu.pl> <40660FEC.8080703@pobox.com> In-Reply-To: <40660FEC.8080703@pobox.com> 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: 757 Lines: 18 Jeff Garzik wrote: > That's the main limitation on request size right now... libata limits > S/G table entries to 128[1], so a perfectly aligned, fully merged ... [1] because even though the block layer properly splits on segment boundaries, pci_map_sg() may violate those boundaries (James B and others are working on fixing this). So... for right now the driver must check the s/g entry boundaries after DMA mapping, and split them (again) if necessary. IDE does this in ide_build_dmatable(). - 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/