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

On Tue, Apr 10, 2018 at 02:26:08PM -0700, Stephen Hemminger wrote:

On Tue, 10 Apr 2018 11:59:50 -0700
Sridhar Samudrala [off-list ref] wrote:

quoted

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.