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=-0.8 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 13DCFC3A5A6 for ; Thu, 19 Sep 2019 11:18:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0C2C21924 for ; Thu, 19 Sep 2019 11:18:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389615AbfISLSY (ORCPT ); Thu, 19 Sep 2019 07:18:24 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:54998 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389541AbfISLSX (ORCPT ); Thu, 19 Sep 2019 07:18:23 -0400 Received: from localhost (unknown [86.58.254.34]) (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 0D127154F9E16; Thu, 19 Sep 2019 04:18:21 -0700 (PDT) Date: Thu, 19 Sep 2019 13:18:16 +0200 (CEST) Message-Id: <20190919.131816.1861650130627229336.davem@davemloft.net> To: steffen.klassert@secunet.com Cc: marcelo.leitner@gmail.com, willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org, pabeni@redhat.com Subject: Re: [PATCH RFC v3 0/5] Support fraglist GRO/GSO From: David Miller In-Reply-To: <20190919110125.GN2879@gauss3.secunet.de> References: <20190918165817.GA3431@localhost.localdomain> <20190919110125.GN2879@gauss3.secunet.de> X-Mailer: Mew version 6.8 on Emacs 26.2 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, 19 Sep 2019 04:18:23 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Steffen Klassert Date: Thu, 19 Sep 2019 13:01:25 +0200 > If the packet data of all the fraglist GRO skbs are backed by a > page fragment then we could just do the same by iterating with > skb_walk_frags(). I'm not a driver expert and might be misstaken, > but it looks like that could be done with existing hardware that > supports segmentation offload. Having to add frag list as well as page frag iterating in a driver is quite a bit of logic, and added complexity. If the frag list SKBs are indeed backed by a page, you could just as easily coalesce everything into the page frag array of the first SKB.