From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [RFC PATCH net-next v6 4/4] netvsc: refactor notifier/event
	handling code to use the bypass framework
Date: Wed, 11 Apr 2018 02:28:51 +0300
Message-ID: <20180411022807-mutt-send-email-mst__28038.0573975437$1523402833$gmane$org@kernel.org>
References: <1523386790-12396-1-git-send-email-sridhar.samudrala@intel.com>
	<1523386790-12396-5-git-send-email-sridhar.samudrala@intel.com>
	<20180410142608.50f15b45@xeon-e3>
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To: Stephen Hemminger <stephen@networkplumber.org>
Cc: alexander.h.duyck@intel.com, virtio-dev@lists.oasis-open.org, jiri@resnulli.us, kubakici@wp.pl, Sridhar Samudrala <sridhar.samudrala@intel.com>, virtualization@lists.linux-foundation.org, loseweigh@gmail.com, netdev@vger.kernel.org, davem@davemloft.net
List-Id: virtualization@lists.linuxfoundation.org

On Tue, Apr 10, 2018 at 02:26:08PM -0700, Stephen Hemminger wrote:
> On Tue, 10 Apr 2018 11:59:50 -0700
> Sridhar Samudrala <sridhar.samudrala@intel.com> wrote:
> 
> > Use the registration/notification framework supported by the generic
> > bypass infrastructure.
> > 
> > Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
> > ---
> 
> Thanks for doing this.  Your current version has couple show stopper
> issues.
> 
> First, the slave device is instantly taking over the slave.
> This doesn't allow udev/systemd to do its device rename of the slave
> device. Netvsc uses a delayed work to workaround this.

Interesting. Does this mean udev must act within a specific time window
then?

> Secondly, the select queue needs to call queue selection in VF.
> The bonding/teaming logic doesn't work well for UDP flows.
> Commit b3bf5666a510 ("hv_netvsc: defer queue selection to VF")
> fixed this performance problem.
> 
> Lastly, more indirection is bad in current climate.
> 
> I am not completely adverse to this but it needs to be fast, simple
> and completely transparent.