From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH net-next v11 2/5] netvsc: refactor notifier/event handling code to use the failover framework Date: Tue, 22 May 2018 16:39:33 +0300 Message-ID: <20180522163502-mutt-send-email-mst@kernel.org> 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> <20180522161007-mutt-send-email-mst@kernel.org> <20180522131422.GG2149@nanopsycho> <20180522161509-mutt-send-email-mst@kernel.org> <20180522132626.GH2149@nanopsycho> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sridhar Samudrala , 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: Jiri Pirko Return-path: Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Content-Disposition: inline In-Reply-To: <20180522132626.GH2149@nanopsycho> List-Id: netdev.vger.kernel.org On Tue, May 22, 2018 at 03:26:26PM +0200, Jiri Pirko wrote: > Tue, May 22, 2018 at 03:17:37PM CEST, mst@redhat.com wrote: > >On Tue, May 22, 2018 at 03:14:22PM +0200, Jiri Pirko wrote: > >> Tue, May 22, 2018 at 03:12:40PM CEST, mst@redhat.com wrote: > >> >On Tue, May 22, 2018 at 11:08:53AM +0200, 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. > >> >> > > >> >> > >> >> 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. > >> > > >> >Or drop IFF_FAILOVER_SLAVE and set both IFF_FAILOVER and IFF_SLAVE? > >> > >> No. IFF_SLAVE is for bonding. > > > >What breaks if we reuse it for failover? > > This is exposed to userspace. IFF_SLAVE is expected for bonding slaves. > And failover slave is not a bonding slave. That does not really answer the question. I'd claim it's sufficiently like a bond slave for IFF_SLAVE to make sense. In fact you will find that netvsc already sets IFF_SLAVE, and so does e.g. the eql driver. The advantage of using IFF_SLAVE is that userspace knows to skip it. If we don't set IFF_SLAVE existing userspace tries to use the lowerdev. -- MST