From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751983AbeDJQcY (ORCPT ); Tue, 10 Apr 2018 12:32:24 -0400 Received: from mail-qk0-f193.google.com ([209.85.220.193]:33026 "EHLO mail-qk0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751367AbeDJQcW (ORCPT ); Tue, 10 Apr 2018 12:32:22 -0400 X-Google-Smtp-Source: AIpwx4+lOfKDNgOo71K33XiUdXEbBTCp7tHXOXG2HhDX5dDQHnoMoi3FGNJPE/pJ1qieB1s14bQASQ== Date: Tue, 10 Apr 2018 13:32:16 -0300 From: Marcelo Ricardo Leitner To: Wenhua Shi Cc: David Miller , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] make net_gso_ok return false when gso_type is zero(invalid) Message-ID: <20180410163216.GB3661@localhost.localdomain> References: <20180406014340.1562-1-march511@gmail.com> <20180408.125114.2111042327285982582.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Apr 08, 2018 at 08:41:21PM +0200, Wenhua Shi wrote: > 2018-04-08 18:51 GMT+02:00 David Miller : > > > > From: Wenhua Shi > > Date: Fri, 6 Apr 2018 03:43:39 +0200 > > > > > Signed-off-by: Wenhua Shi > > > > This precondition should be made impossible instead of having to do > > an extra check everywhere that this helper is invoked, many of which > > are in fast paths. > > I believe the precondition you said is quite true. In my situation, I > have to disable GSO for some packet and I notice that it leads to a > worse performance (slower than 1Mbps, was almost 800Mbps). > > Here's the hook I use on debian 9.4, kernel version 4.9: There is quite a distance between 4.9 and net/net-next. Did you test on a more recent kernel too? Note that TCP stack now works with GSO being always on. 0a6b2a1dc2a2 ("tcp: switch to GSO being always on")