From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] sata_sil: Greatly improve DMA support Date: Sat, 19 May 2007 18:03:44 -0400 Message-ID: <464F7440.10900@garzik.org> References: <20070519053532.GA32522@havoc.gtf.org> <1441.81.207.0.53.1179591630.squirrel@secure.samage.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:58364 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756755AbXESWDr (ORCPT ); Sat, 19 May 2007 18:03:47 -0400 In-Reply-To: <1441.81.207.0.53.1179591630.squirrel@secure.samage.net> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Indan Zupancic Cc: linux-ide@vger.kernel.org, LKML , Alan Cox Indan Zupancic wrote: > This patch seems to work with my SiI 3512, though I don't notice any > difference, neither a speedup, nor a slowdown. Hdparm gives the same > speeds (-tT), and cp -a'ing kernel sources is abysmal slow in both cases, > (need to look into that one) so I didn't really test it that well. It won't result in much of a speedup, except in situations where IOMMU or other situation that causes you to run into the 64k boundary being an issue -- generally only on huge transfers. A good measure is to dd(1) to/from the block device, rather than using a filesystem. As has been shown on LKML, the filesystem can really slow things down in some cases. Jeff