From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net 1/2] packet: do skb_probe_transport_header when we actually have data Date: Sat, 07 Nov 2015 10:53:50 -0800 Message-ID: <1446922430.17135.13.camel@edumazet-glaptop2.roam.corp.google.com> References: <5cdcd969eec9228a18c0dc54f9cc4b7b6b07ce05.1446842228.git.daniel@iogearbox.net> <1446900176.17135.4.camel@edumazet-glaptop2.roam.corp.google.com> <20151107.133502.833614670001999282.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: daniel@iogearbox.net, edumazet@google.com, willemb@google.com, tklauser@distanz.ch, netdev@vger.kernel.org, jasowang@redhat.com To: David Miller Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:35586 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753551AbbKGSxw (ORCPT ); Sat, 7 Nov 2015 13:53:52 -0500 Received: by pasz6 with SMTP id z6so159879782pas.2 for ; Sat, 07 Nov 2015 10:53:51 -0800 (PST) In-Reply-To: <20151107.133502.833614670001999282.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2015-11-07 at 13:35 -0500, David Miller wrote: > From: Eric Dumazet > Date: Sat, 07 Nov 2015 04:42:56 -0800 > > > The if (!packet_use_direct_xmit(po)) test looks dubious. > > > > Setting transport header has nothing to do with bypassing qdisc ? > > > > This might lead to hard to debug problems, for drivers expecting > > transport header being set ? > > Do we have any such drivers that need it in this scenerio? Well, imagine following scenario (a real one, as I use it all of time, thus how I discovered all trafgen traffic ends up on one slave only) Even if qdisc is bypassed on the bond0, the current handling does not prevent going to the slave qdiscs. So it is not clear to me why we do a selective probe depending on the bypass of first qdisc.