From owner-svn-src-head@FreeBSD.ORG Fri Oct 17 18:42:46 2008 Return-Path: Delivered-To: svn-src-head@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B8F371065688; Fri, 17 Oct 2008 18:42:46 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id 6BB0B8FC15; Fri, 17 Oct 2008 18:42:46 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.home (pooker.samsco.home [192.168.254.1]) by pooker.samsco.org (8.14.2/8.14.2) with ESMTP id m9HIgg4p062391; Fri, 17 Oct 2008 12:42:43 -0600 (MDT) (envelope-from scottl@samsco.org) Date: Fri, 17 Oct 2008 12:42:42 -0600 (MDT) From: Scott Long To: John Baldwin In-Reply-To: <200810171603.m9HG3buK092293@svn.freebsd.org> Message-ID: <20081017123919.C22184@pooker.samsco.org> References: <200810171603.m9HG3buK092293@svn.freebsd.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Spam-Status: No, score=-4.4 required=3.8 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.1.8 X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on pooker.samsco.org Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r183981 - head/sys/dev/ata/chipsets X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Oct 2008 18:42:46 -0000 On Fri, 17 Oct 2008, John Baldwin wrote: > Author: jhb > Date: Fri Oct 17 16:03:37 2008 > New Revision: 183981 > URL: http://svn.freebsd.org/changeset/base/183981 > > Log: > - For chipsets that can't do 64k transfers, fall back to 32k transfers > (still a power of 2) rather than 63k transfers. Even with 63k transfers > some machines (such as Dell SC1435's) were experiencing chronic data > corruption. It should be noted that breaking a 64K transfer into two 32K transfers is much more ideal than breaking it into a 63k transfer plus a 1k runt. Modern drive firmware actually sees the disk internally as 4k sectors now instead of 512 byte, so avoiding runt transfers and non-power-of-2 transfers helps quite a bit with performance. > - Use the MIO method to talk to the Serverworks HT1000_S1 SATA controller > like all the other SATA controllers rather than the compat PATA > method. This lets the controller see all 4 SATA ports and also > matches the behavior of the Linux driver. Thanks for working on these two issues. Scott