From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752935AbdDHSpa (ORCPT ); Sat, 8 Apr 2017 14:45:30 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:48746 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751955AbdDHSpT (ORCPT ); Sat, 8 Apr 2017 14:45:19 -0400 Date: Sat, 08 Apr 2017 11:45:15 -0700 (PDT) Message-Id: <20170408.114515.1339820744697810446.davem@davemloft.net> To: ksiva@linux.vnet.ibm.com Cc: netdev@vger.kernel.org, tlfalcon@linux.vnet.ibm.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, brking@linux.vnet.ibm.com, seroyer@linux.vnet.ibm.com Subject: Re: [PATCH] ibmveth: Support to enable LSO/CSO for Trunk VEA. From: David Miller In-Reply-To: <1491559079-10855-1-git-send-email-ksiva@linux.vnet.ibm.com> References: <1491559079-10855-1-git-send-email-ksiva@linux.vnet.ibm.com> X-Mailer: Mew version 6.7 on Emacs 25.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 08 Apr 2017 11:04:00 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sivakumar Krishnasamy Date: Fri, 7 Apr 2017 05:57:59 -0400 > Enable largesend and checksum offload for ibmveth configured in trunk mode. > Added support to SKB frag_list in TX path by skb_linearize'ing such SKBs. > > Signed-off-by: Sivakumar Krishnasamy Why is linearization necessary? It would seem that the gains you get from GRO are nullified by linearizing the SKB and thus copying all the data around and allocating buffers. Finally, all of that new checksumming stuff looks extremely suspicious. You have to explain why that is happening and why it isn't because this driver is doing something incorrectly. Thanks.