From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264094AbTDOV2L (for ); Tue, 15 Apr 2003 17:28:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264099AbTDOV1P (for ); Tue, 15 Apr 2003 17:27:15 -0400 Received: from c-97a870d5.037-69-73746f23.cust.bredbandsbolaget.se ([213.112.168.151]:56960 "EHLO zaphod.guide") by vger.kernel.org with ESMTP id S264098AbTDOV1M (for ); Tue, 15 Apr 2003 17:27:12 -0400 To: Alan Cox Cc: Linux Kernel Mailing List Subject: Re: DMA transfers in 2.5.67 References: <1050438684.28586.8.camel@dhcp22.swansea.linux.org.uk> From: mru@users.sourceforge.net (=?iso-8859-1?q?M=E5ns_Rullg=E5rd?=) Date: 15 Apr 2003 23:38:14 +0200 In-Reply-To: <1050438684.28586.8.camel@dhcp22.swansea.linux.org.uk> Message-ID: User-Agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.4 (Portable Code) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox writes: > > What do I need to do in a driver before doing DMA transfers to a PCI > > card? Using a driver that worked in 2.4 gives a throughput of only 10 > > MB/s in 2.5.67. Is there some magic initialization that I have > > missed? > > Assuming your driver uses the new PCI api for DMA in 2.4/2.5 then there > isnt really anything to watch. Is this on a box with > 800Mb of memory > however ? It's an Alpha with 768 MB. Is it the pci_alloc_* functions you are referring to? I don't think they are used currently. How much memory can these allocate? I need chunks of up to 1 MB, not necessarily phycically continuous. What do those functions do that normal memory allocation does not? Apart from setting up sg mappings, that is. -- Måns Rullgård mru@users.sf.net