From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268779AbUJKLFT (ORCPT ); Mon, 11 Oct 2004 07:05:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268781AbUJKLFT (ORCPT ); Mon, 11 Oct 2004 07:05:19 -0400 Received: from a26.t1.student.liu.se ([130.236.221.26]:62143 "EHLO mail.drzeus.cx") by vger.kernel.org with ESMTP id S268779AbUJKLFN (ORCPT ); Mon, 11 Oct 2004 07:05:13 -0400 Message-ID: <416A68E5.6080608@drzeus.cx> Date: Mon, 11 Oct 2004 13:05:09 +0200 From: Pierre Ossman User-Agent: Mozilla Thunderbird 0.8 (X11/20040919) X-Accept-Language: en-us, en MIME-Version: 1.0 To: LKML , Russell King Subject: MMC performance X-Enigmail-Version: 0.84.2.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I've added SGIO support to my driver now hoping that it would resolve the piss-poor performance I've been getting. Didn't do much difference though. Read operations are fairly fast. It queues 8kB at a time. A bit small perhaps, but still decent. Writing, however, only sends a single sector at a time. The queue process eats up half of the CPU time on my machine during a write. And since MMC cards have to clear a whole bunch of sectors before a write shouldn't you send as many sectors as possible to them? Since I don't have another controller to compare with I don't really know if the problem is in my code, the MMC layer, the block layer or the filesystem. I'm going to dig around a bit more but some pointers are welcome. At least which layer I should be looking at. Rgds Pierre