From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Wuertele Subject: Compact Flash PIO 4 tuning Date: Mon, 05 May 2003 17:53:35 -0700 Sender: linux-ide-owner@vger.kernel.org Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from main.gmane.org ([80.91.224.249]:41943 "EHLO main.gmane.org") by vger.kernel.org with ESMTP id S262235AbTEFAlH (ORCPT ); Mon, 5 May 2003 20:41:07 -0400 Received: from list by main.gmane.org with local (Exim 3.35 #1 (Debian)) id 19Cqgp-0005iI-00 for ; Tue, 06 May 2003 02:52:15 +0200 List-Id: linux-ide@vger.kernel.org To: linux-ide@vger.kernel.org Howdy, I'm working on an embedded system that has a CF card on the IDE bus. The CF spec only allows PIO mode, and my card can do PIO 4. However, when I try to stream data from this card into memory at 2 MBytes per second, it pegs the CPU at 100%. This is ruining the performance of my application, which has to process this data in real time. I realize that PIO 4 requires CPU involvement, but are there ways I can tune the kernel for copying large files to memory, so that my application doesn't get starved of CPU? Thanks, Dave