From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [net-next PATCH] veth: don't assign a qdisc to veth Date: Fri, 03 Oct 2014 14:56:04 -0700 (PDT) Message-ID: <20141003.145604.344775445146119193.davem@davemloft.net> References: <20141003223816.6c56e6d8@redhat.com> <1412369519.17245.2.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: brouer@redhat.com, cwang@twopensource.com, netdev@vger.kernel.org, jpirko@redhat.com, mpatel@redhat.com To: eric.dumazet@gmail.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:59984 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755155AbaJCVyC (ORCPT ); Fri, 3 Oct 2014 17:54:02 -0400 In-Reply-To: <1412369519.17245.2.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Fri, 03 Oct 2014 13:51:59 -0700 > On Fri, 2014-10-03 at 22:38 +0200, Jesper Dangaard Brouer wrote: >> On Fri, 3 Oct 2014 09:53:16 -0700 >> Cong Wang wrote: >> >> > On Fri, Oct 3, 2014 at 3:48 AM, Jesper Dangaard Brouer >> > wrote: >> > > The veth driver is a virtual device, and should not have assigned >> > > the default qdisc. Verified (ndo_start_xmit) veth_xmit can only >> > > return NETDEV_TX_OK, thus this should be safe to bypass qdisc. >> > > >> > > Not assigning a qdisc is subtly done by setting tx_queue_len to zero. >> > > >> > >> > Huh?? Maybe your $subject is too misleading, but we do use HTB >> > on veth, this will break our code since we will have to set tx_queue_len >> > after your patch, no? >> >> No, you HTB setup should still work. > > Unfortunately no.... > > Default htb classes are pfifo, and this uses device txqueuelen as > default limit. > > So your change should have been done years ago. > > Now its too late as it can break existing user scripts. Agreed, this change cannot be made.