Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755567AbXKEXPz (ORCPT ); Mon, 5 Nov 2007 18:15:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754384AbXKEXPq (ORCPT ); Mon, 5 Nov 2007 18:15:46 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:41737 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754253AbXKEXPp (ORCPT ); Mon, 5 Nov 2007 18:15:45 -0500 Date: Mon, 05 Nov 2007 15:15:44 -0800 (PST) Message-Id: <20071105.151544.175839612.davem@davemloft.net> To: kaber@trash.net Cc: djohnson+linux-kernel@sw.starentnetworks.com, jes@trained-monkey.org, mchan@broadcom.com, ram.vepa@neterion.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bguo@sw.starentnetworks.com Subject: Re: [PATCH 1/2] NET: Re-add VLAN tag for devices incapable of keeping it From: David Miller In-Reply-To: <472F5A33.20906@trash.net> References: <472A6089.7020104@hp.com> <18223.22291.622615.129374@zeus.sw.starentnetworks.com> <472F5A33.20906@trash.net> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 981 Lines: 22 From: Patrick McHardy Date: Mon, 05 Nov 2007 19:00:19 +0100 > This looks like a rather expensive operation for the unlikely case > that packets will be received by a packet socket. IMO it should only > be reconstructed if actually needed, by af_packet itself. Completely agreed. We should not do this by default when %99 of the networking stack simply does not care about this. > As we discussed some time back storing the VLAN tag in the CB on > TX clashes with other users of the CB like qdiscs, so we need a > new field in the skb for this anyway. Someone will have to find a way to remove some other fields in sk_buff before I'm going to allow more space to be eaten up by this completely fringe case feature. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/