From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757814Ab3GWPRd (ORCPT ); Tue, 23 Jul 2013 11:17:33 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:51164 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757620Ab3GWPRb (ORCPT ); Tue, 23 Jul 2013 11:17:31 -0400 Date: Tue, 23 Jul 2013 08:17:27 -0700 From: Stephen Hemminger To: Jason Wang Cc: davem@davemloft.net, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Basil Gor Subject: Re: [PATCH net-next] tuntap: hardware vlan tx support Message-ID: <20130723081727.69766d27@nehalam.linuxnetplumber.net> In-Reply-To: <1374563748-38821-1-git-send-email-jasowang@redhat.com> References: <1374563748-38821-1-git-send-email-jasowang@redhat.com> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 23 Jul 2013 15:15:48 +0800 Jason Wang wrote: > Inspired by commit f09e2249c4f5c7c13261ec73f5a7807076af0c8e (macvtap: restore > vlan header on user read). This patch adds hardware vlan tx support for > tuntap. This is done by copying vlan header directly into userspace in > tun_put_user() instead of doing it through __vlan_put_tag() in > dev_hard_start_xmit(). This eliminates one unnecessary memove in > vlan_insert_tag() for 802.1ad and 802.1q traffic. > > pktgen test shows about 20% improvement for 802.1q traffic: > > Before: > 662149pps 317Mb/sec (317831520bps) errors: 0 > After: > 801033pps 384Mb/sec (384495840bps) errors: 0 > > Cc: Basil Gor > Cc: Michael S. Tsirkin > Signed-off-by: Jason Wang You need to make this configurable by some mechanism, since otherwise it will break applications that expect current VLAN behavior