Subject: Re: [RFC PATCH net-next v6 4/4] netvsc: refactor notifier/event handling code to use the bypass framework

From: Stephen Hemminger <[email-masked]>
Date: Tue, 10 Apr 2018 14:26:08 -0700

On Tue, 10 Apr 2018 11:59:50 -0700
Sridhar Samudrala <[email-masked]> wrote:

> Use the registration/notification framework supported by the generic
> bypass infrastructure.
> 
> Signed-off-by: Sridhar Samudrala <[email-masked]>
> ---

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.

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.