From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v1 1/6] net: Generalize udp based tunnel offload Date: Tue, 24 Nov 2015 13:37:54 -0500 (EST) Message-ID: <20151124.133754.654421175431044735.davem@davemloft.net> References: <20151123171103.00007699@unknown> <1448387015.235472.448970977.10694A74@webmail.messagingengine.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: tom@herbertland.com, jesse.brandeburg@intel.com, anjali.singhai@intel.com, jesse@kernel.org, netdev@vger.kernel.org, kiran.patil@intel.com To: hannes@stressinduktion.org Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:43519 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754278AbbKXSh6 (ORCPT ); Tue, 24 Nov 2015 13:37:58 -0500 In-Reply-To: <1448387015.235472.448970977.10694A74@webmail.messagingengine.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Hannes Frederic Sowa Date: Tue, 24 Nov 2015 18:43:35 +0100 > On Tue, Nov 24, 2015, at 18:32, Tom Herbert wrote: >> As you said this in only feedback and nobody is forcing anyone to do >> anything. But encouraging HW vendors to provide generic mechanisms so >> that your users can use whatever protocol they want is the exact >> _opposite_ of punishing users, this is very much a pro-user direction. > > Some users will suffer worse performance in case we don't correctly set > ip_summed for a specific protocol before we do the copy operations from > user space into skbs but if they are always done in the driver. Your concern presumes that looking backwards is as important as looking forward. We want to simplify things _and_ move away from protocol specific csums, and if some old crufty hardware based systems pay some performance cost for this I say so be it. So this is not a valid argument against Tom's changes in my mind.