From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: sata_sil performance Date: Thu, 02 Dec 2004 06:29:59 -0500 Message-ID: <41AEFCB7.9030108@pobox.com> References: <1101680376.5337.5.camel@kahuna-ws.robhughes.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:2508 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S261583AbULBLaO (ORCPT ); Thu, 2 Dec 2004 06:30:14 -0500 In-Reply-To: <1101680376.5337.5.camel@kahuna-ws.robhughes.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Rob Hughes Cc: linux-ide@vger.kernel.org Rob Hughes wrote: > Jeff, > > I can understand why you did what you did looking through the code, but > my drive, a Seagate ST3120026AS, does not need this fix. Further, > performance has gone from 50-60 Mbit transfers to 14-15 Mbit transfers > between the 2.6.8 and 2.6.9 kernels. And as a side not, hdparm is > reporting "HDIO_GET_MULTCOUNT failed: Inappropriate ioctl for device" > when doing either -I or -i as of this kernel version. multcount is for PIO transfers, don't worry about it. If you are doing PIO you are already slower than 15Mbit. > If you're already working on a patch for this, I'd be happy to test it. > Also, it should be noted that I'm running FC3, so I'm not sure how much > that will play into this. Unfortunately at this time we must judge the situation as "you just haven't hit the problem yet". Yeah, the performance hit sucks, but the kernel _must_ be conservative and err on the side of caution. Jeff