Re: [patch net-next 0/9] Introduce devlink interface and first drivers to use it

On Tue, Feb 23, 2016 at 03:45:51PM +0100, Jiri Pirko wrote:

Tue, Feb 23, 2016 at 03:34:19PM CET, gospo@cumulusnetworks.com wrote:

<snip>

quoted

quoted

quoted

quoted

	myhost:~$ dl port show
	devlink0/1: type eth netdev ens4

                            ^^^^^^^^^^^

quoted

	devlink0/2: type ib ibdev mlx4_0

                           ^^^^^^^^^^^^
I think my only other question about this implementation is whether or
not one would really want to have the true netdev/ibdev names mapped
here.

Would be as reasonable to simply specify the type (and there may be more
types within ethernet that could be useful in multi-chip configurations)
and then let normal infrastructure that exists today figure out how to
map the names for the netdevs to the devices?

What normal infrastructure you have in mind? There is no info about
devlink port mapping to netdev/ibdev anywhere. Only here. I might be
missing something but I fail to see what's wrong with it.

I was simply wondering out loud if we _really_ wanted to name netdevs
this way.  I was suggesting that output could be like this:

myhost:~$ dl port show
devlink0/1: type eth
devlink0/2: type ib 

mnd that udev/systemd/biosdevname/etc would take care of naming the
device whataever it wanted.  This appears to be essentially the same
concern Hannes has.

Wait. The only thing which will be renamed by udev is "devlink0". The
suffixes "/1" and "/2" are direct indexes as used inside the driver.

And you need some link to netdev in case netdev exists - therefore
"netdev ens4" attribute is there. There's no other way to get the
mapping of "devlink0/1" to "ens4" anywhere else.

So I think I had invisioned a slightly different workflow than what you
just described.

- Load PCI driver
- Setup devlink attributes for your hardware
- Create netdevs in network driver based on those attributes

You don't need a netdev to reference any of the devlink specific
parameters do you?