Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263571AbVBCTEo (ORCPT ); Thu, 3 Feb 2005 14:04:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263567AbVBCTEm (ORCPT ); Thu, 3 Feb 2005 14:04:42 -0500 Received: from [195.23.16.24] ([195.23.16.24]:14979 "EHLO bipbip.comserver-pie.com") by vger.kernel.org with ESMTP id S263014AbVBCTES (ORCPT ); Thu, 3 Feb 2005 14:04:18 -0500 Message-ID: <42027594.9090402@grupopie.com> Date: Thu, 03 Feb 2005 19:03:48 +0000 From: Paulo Marques Organization: Grupo PIE User-Agent: Mozilla Thunderbird 0.7.1 (X11/20040626) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Ian Godin Cc: linux-kernel@vger.kernel.org Subject: Re: Drive performance bottleneck References: <42026207.4090007@vgertech.com> In-Reply-To: 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: 1155 Lines: 31 Ian Godin wrote: > [...] > Definitely have been able to repeat that here, so the SG driver > definitely appears to be broken. At least I'm glad I am not going > insane, I was starting to wonder :) > > I'll run some more tests with O_DIRECT and such things, see if I can > figure out what the REAL max speed is. FYI there was a patch running around last April that made a new option for "dd" to make it use O_DIRECT. You can get it here: http://marc.theaimsgroup.com/?l=linux-kernel&m=108135935629589&w=2 Unfortunately this hasn't made it into coreutils. IIRC there were issues about dd being multi-platform and the way O_DIRECT was done in other systems. Anyway, you can patch dd yourself and have a tool for debugging with O_DIRECT. I hope this helps, -- Paulo Marques - www.grupopie.com All that is necessary for the triumph of evil is that good men do nothing. Edmund Burke (1729 - 1797) - 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/