From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264982AbUEYRMH (ORCPT ); Tue, 25 May 2004 13:12:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264980AbUEYRMH (ORCPT ); Tue, 25 May 2004 13:12:07 -0400 Received: from mail.skule.net ([216.235.14.165]:32643 "EHLO mail.skule.net") by vger.kernel.org with ESMTP id S264984AbUEYRJd (ORCPT ); Tue, 25 May 2004 13:09:33 -0400 Date: Tue, 25 May 2004 13:09:31 -0400 From: Mark Frazer To: Linux Kernel List Subject: [OT] scatter-gather ops within host memory on a PC Message-ID: <20040525170931.GE10775@mjfrazer.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Message-Flag: Outlook not so good. Organization: Detectable, well, not really X-Fry: Where's Captain Bender? Off catastrophizing some other planet? User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I'd like to aggregate a bunch of ethernet packet payloads into a single large buffer after examining the packet headers to determine the order of the packets. The data volume makes offloading this to a DMA controller desirable. Do PC chipsets have DMA controllers on them to do these scatter-gather operations? I know a lot of embedded SoC processors do, but am not to familiar with the current PC chipsets. I've glanced at the NFS code but haven't studied it a lot. rxrpc/transport.c seems to copy some data around, so I assume that linux uses the host processor to gather the individual ethernet packets into pages that go into the page cache. Are there any good books anyone would recommend on PC architecture? thanks -mark -- The laws of science be a harsh mistress. - Bender