Re: [patch net-next v2 0/9] Introduce devlink interface and first drivers to use it

On Thu, Feb 25, 2016 at 03:12:47PM -0500, David Miller wrote:

From: Jiri Pirko <jiri@resnulli.us>
Date: Tue, 23 Feb 2016 16:51:25 +0100

quoted

There a is need for some userspace API that would allow to expose things
that are not directly related to any device class like net_device of
ib_device, but rather chip-wide/switch-ASIC-wide stuff.

Use cases:
1) get/set of port type (Ethernet/InfiniBand)
2) setting up port splitters - split port into multiple ones and squash again,
   enables usage of splitter cable
3) setting up shared buffers - shared among multiple ports within
   one chip (work in progress)
4) configuration of switch wide properties - resources division etc - This will
   allow to pass configuration that is unacceptable to be passed as
   a module option.

First patch of this set introduces a new generic Netlink based interface,
called "devlink". It is similar to nl80211 model and it is heavily
influenced by it, including the API definition. The devlink introduction patch
implements use cases 1) and 2). Other 2 are in development atm and will
be addressed by follow-ups.

It is very convenient for drivers to use devlink, as you can see in other
patches in this set.

Counterpart for devlink is userspace tool for now called "dl". Command line
interface and outputs are derived from "ip" tool so it should be easy
for users to get used to it.

I am very close to applying this series as-is.

The clincher for me is that there is precendence in the nl80211 stuff,
so obviously whatever userland infrastructure sits on top of that has
found a way to deal whatever perceived shortcomings devlink has.

If all that people can come up with is "device names! omg UDEV!" and
"multiple tools are hard to use!"  That's awesome, because it means
nobody has any real substantial objection to this facility. :-)

Generally speaking I had no issue with the patch after being *ahem*
corrected to realize that the set operations only applied to the devlink
devices not specifically to netdevs.

I find this interface useful for some other items we have discussed in
the past (resource limits for routes, etc), so I'm happy to see some
interface for general chip maintenance included.