From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [PATCH net-next v11 2/5] netvsc: refactor notifier/event handling code to use the failover framework Date: Wed, 23 May 2018 08:27:48 +0200 Message-ID: <20180523062748.GA3155@nanopsycho> References: <1526954781-35359-1-git-send-email-sridhar.samudrala@intel.com> <1526954781-35359-3-git-send-email-sridhar.samudrala@intel.com> <20180522090637.GE2149@nanopsycho> <20180522090853.GF2149@nanopsycho> <39081bce-3913-5b07-3d07-0c476fca5e78@intel.com> <20180522153614.GK2149@nanopsycho> <20180522184112-mutt-send-email-mst@kernel.org> <20180522161246.GN2149@nanopsycho> <8f611f3b-88d7-4d41-fd47-d07f11d0f25a@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Cc: "Michael S. Tsirkin" , stephen@networkplumber.org, davem@davemloft.net, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, virtio-dev@lists.oasis-open.org, jesse.brandeburg@intel.com, alexander.h.duyck@intel.com, kubakici@wp.pl, jasowang@redhat.com, loseweigh@gmail.com, aaron.f.brown@intel.com, anjali.singhai@intel.com To: "Samudrala, Sridhar" Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:33275 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753989AbeEWG2A (ORCPT ); Wed, 23 May 2018 02:28:00 -0400 Received: by mail-wm0-f66.google.com with SMTP id x12-v6so19989351wmc.0 for ; Tue, 22 May 2018 23:27:59 -0700 (PDT) Content-Disposition: inline In-Reply-To: <8f611f3b-88d7-4d41-fd47-d07f11d0f25a@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: Tue, May 22, 2018 at 10:54:29PM CEST, sridhar.samudrala@intel.com wrote: > > >On 5/22/2018 9:12 AM, Jiri Pirko wrote: >> Fixing the subj, sorry about that. >> >> Tue, May 22, 2018 at 05:46:21PM CEST, mst@redhat.com wrote: >> > On Tue, May 22, 2018 at 05:36:14PM +0200, Jiri Pirko wrote: >> > > Tue, May 22, 2018 at 05:28:42PM CEST, sridhar.samudrala@intel.com wrote: >> > > > On 5/22/2018 2:08 AM, Jiri Pirko wrote: >> > > > > Tue, May 22, 2018 at 11:06:37AM CEST, jiri@resnulli.us wrote: >> > > > > > Tue, May 22, 2018 at 04:06:18AM CEST, sridhar.samudrala@intel.com wrote: >> > > > > > > Use the registration/notification framework supported by the generic >> > > > > > > failover infrastructure. >> > > > > > > >> > > > > > > Signed-off-by: Sridhar Samudrala >> > > > > > In previous patchset versions, the common code did >> > > > > > netdev_rx_handler_register() and netdev_upper_dev_link() etc >> > > > > > (netvsc_vf_join()). Now, this is still done in netvsc. Why? >> > > > > > >> > > > > > This should be part of the common "failover" code. >> > > > Based on Stephen's feedback on earlier patches, i tried to minimize the changes to >> > > > netvsc and only commonize the notifier and the main event handler routine. >> > > > Another complication is that netvsc does part of registration in a delayed workqueue. >> > > :( This kind of degrades the whole efford of having single solution >> > > in "failover" module. I think that common parts, as >> > > netdev_rx_handler_register() and others certainly is should be inside >> > > the common module. This is not a good time to minimize changes. Let's do >> > > the thing properly and fix the netvsc mess now. >> > > >> > > >> > > > It should be possible to move some of the code from net_failover.c to generic >> > > > failover.c in future if Stephen is ok with it. >> > > > >> > > > >> > > > > Also note that in the current patchset you use IFF_FAILOVER flag for >> > > > > master, yet for the slave you use IFF_SLAVE. That is wrong. >> > > > > IFF_FAILOVER_SLAVE should be used. >> > > > Not sure which code you are referring to.  I only set IFF_FAILOVER_SLAVE >> > > > in patch 3. >> > > The existing netvsc driver. >> > We really can't change netvsc's flags now, even if it's interface is >> > messy, it's being used in the field. We can add a flag that makes netvsc >> > behave differently, and if this flag also allows enhanced functionality >> > userspace will gradually switch. >> Okay, although in this case, it really does not make much sense, so be >> it. Leave the netvsc set the ->priv flag to IFF_SLAVE as it is doing >> now. (This once-wrong-forever-wrong policy is flustrating me). >> >> But since this patchset introduces private flag IFF_FAILOVER and >> IFF_FAILOVER_SLAVE, and we set IFF_FAILOVER to the netvsc netdev >> instance, we should also set IFF_FAILOVER_SLAVE to the enslaved VF >> netdevice to get at least some consistency between virtio_net and >> netvsc. > >OK. I can make this change to set/unset IFF_FAILOVER_SLAVE in the netvsc >register/unregister routines so that it is consistent with virtio_net. > >Based on your discussion with mst, i think we can even remove IFF_SLAVE >setting on netvsc as it should not impact userspace. If Stephen is OK >we can make this change too. > >Do you see any other items that need to be resolved for this series to go in >this merge window? As I wrote previously, the common code including rx_handler registration and setting of flags and master link should be done in a common code, moved away from netvsc code. Thanks. > > > >> >> > Anything breaking userspace I fully expect Stephen to nack and >> > IMO with good reason. >> > >> > -- >> > MST >