Re: [RFC PATCH] virtio_net: Extend virtio to use VF datapath when available

On Tue, 19 Dec 2017 11:42:33 -0800
"Samudrala, Sridhar" [off-list ref] wrote:

On 12/19/2017 10:41 AM, Stephen Hemminger wrote:

quoted

On Tue, 19 Dec 2017 13:21:17 -0500 (EST)
David Miller [off-list ref] wrote:
 

quoted

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Tue, 19 Dec 2017 09:55:48 -0800
 

quoted

could be 10ms, just enough to let udev do its renaming  

Please, move to some kind of notification or event based handling of
this problem.

No delay is safe, what if userspace gets swapped out or whatever
else might make userspace stall unexpectedly?
 

The plan is to remove the delay and do the naming in the kernel.
This was suggested by Lennart since udev is only doing naming policy
because kernel names were not repeatable.

This makes the VF show up as "ethN_vf" on Hyper-V which is user friendly.

Patch is pending.  

Do we really need to delay the setup until the name is changed?
Can't we call dev_set_mtu() and dev_open() until dev_change_name() is done?

Thanks
Sridhar

You can call dev_set_mtu, but when dev_open is done the device name
can not be changed by userspace.