From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BBBDC33C9B for ; Fri, 15 Nov 2019 01:25:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E82020723 for ; Fri, 15 Nov 2019 01:25:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727453AbfKOBZL (ORCPT ); Thu, 14 Nov 2019 20:25:11 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:57042 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726956AbfKOBZK (ORCPT ); Thu, 14 Nov 2019 20:25:10 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:1e2::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id D988314B72710; Thu, 14 Nov 2019 17:25:08 -0800 (PST) Date: Thu, 14 Nov 2019 17:25:08 -0800 (PST) Message-Id: <20191114.172508.1027995193093100862.davem@davemloft.net> To: alobakin@dlink.ru Cc: ecree@solarflare.com, jiri@mellanox.com, edumazet@google.com, idosch@mellanox.com, pabeni@redhat.com, petrm@mellanox.com, sd@queasysnail.net, f.fainelli@gmail.com, jaswinder.singh@linaro.org, manishc@marvell.com, GR-Linux-NIC-Dev@marvell.com, johannes.berg@intel.com, emmanuel.grumbach@intel.com, luciano.coelho@intel.com, linuxwifi@intel.com, kvalo@codeaurora.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next] net: core: allow fast GRO for skbs with Ethernet header in head From: David Miller In-Reply-To: <20191112122843.30636-1-alobakin@dlink.ru> References: <20191112122843.30636-1-alobakin@dlink.ru> X-Mailer: Mew version 6.8 on Emacs 26.1 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]); Thu, 14 Nov 2019 17:25:09 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Lobakin Date: Tue, 12 Nov 2019 15:28:43 +0300 > Commit 78d3fd0b7de8 ("gro: Only use skb_gro_header for completely > non-linear packets") back in May'09 (2.6.31-rc1) has changed the > original condition '!skb_headlen(skb)' to the current > 'skb_mac_header(skb) == skb_tail_pointer(skb)' in gro_reset_offset() > saying: "Since the drivers that need this optimisation all provide > completely non-linear packets". Please reference the appropriate SHA1-ID both here in this paragraph and also in an appropriate Fixes: tag. If this goes so far back that it is before GIT, then you need to provide a reference to the patch posting via lore.kernel.org or similar because it is absolutely essentialy for people reviewing this patch to be able to do some digging into why the condition is code the way that it is currently. Thank you.