From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 7 Jan 2001 14:24:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 7 Jan 2001 14:24:39 -0500 Received: from mail.zmailer.org ([194.252.70.162]:53518 "EHLO zmailer.org") by vger.kernel.org with ESMTP id ; Sun, 7 Jan 2001 14:24:25 -0500 Date: Sun, 7 Jan 2001 21:24:14 +0200 From: Matti Aarnio To: jamal Cc: linux-kernel@vger.kernel.org, netdev@oss.sgi.com Subject: Re: [PATCH] hashed device lookup (Does NOT meet Linus' sumission Message-ID: <20010107212414.B25659@mea-ext.zmailer.org> In-Reply-To: <20010107210036.G25076@mea-ext.zmailer.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from hadi@cyberus.ca on Sun, Jan 07, 2001 at 02:10:52PM -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jan 07, 2001 at 02:10:52PM -0500, jamal wrote: > On Sun, 7 Jan 2001, Matti Aarnio wrote: > > Read what I wrote about the issue to Alan. > > Ben's code has no problems with receiving VLANs with network > > cards which have "hardware support" for VLANs. > > OK. I suppose an skb->vlan_tag is passed to the driver and it will know > what to do with it (pass it on a descriptor etc). Sure, nice. WHY SHOULD THERE BE MORE LAYER-2 STUFF ADDED TO SKB OBJECTS ? One of important abstraction issues is to isolate device specific new things (like what VLAN/PVC/SVC is used at your favourtite 802.1Q/ATM/X.25/FrameRelay connection). The less we leak that kind of things to SKB, the better, IMO. They are net_device issues, after all. Tell me (if you can), why packet sender calls hardware-header generation for packet, if the card can insert it for you ? Consider the structure of Ethernet MAC header, where is source address ? Where is the destination address ? If you write the destination, why should you not write the source there too ? No doubt some cards can fill in the source address while doing frame transmit, but is it worth the hazzle ? > cheers, > jamal /Matti Aarnio - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/