From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Olivier Crameri" Subject: Offloading features in VLAN interfaces Date: Fri, 29 Sep 2006 17:21:44 -0700 Message-ID: Reply-To: olivier.crameri@epfl.ch Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Yoshio Turner" , "Santos, Jose Renato G" , "Janakiraman, John" Return-path: Received: from ug-out-1314.google.com ([66.249.92.175]:22289 "EHLO ug-out-1314.google.com") by vger.kernel.org with ESMTP id S932365AbWI3AVq (ORCPT ); Fri, 29 Sep 2006 20:21:46 -0400 Received: by ug-out-1314.google.com with SMTP id o38so328011ugd for ; Fri, 29 Sep 2006 17:21:44 -0700 (PDT) To: netdev@vger.kernel.org Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi, after running some experiments, we realised that using VLAN support in Linux caused some overhead. It turned out to be that the offloading features of our NIC (tso, sg, checksum offloading) were not beeing used. After digging a little bit in the code, we realised that the VLAN code did not set the features parameter of the net_device structure for the virtual interface. Attached is a patch with a suggested solution to this problem. Please let us know if this is an acceptable patch. Thanks, Olivier Crameri, HP Labs