Re: [PATCH net-next v2 00/10] net: dsa: add generic debugfs interface

Tue, Aug 29, 2017 at 02:50:04PM CEST, andrew@lunn.ch wrote:

On Tue, Aug 29, 2017 at 08:25:23AM +0200, Jiri Pirko wrote:

quoted

Mon, Aug 28, 2017 at 10:08:34PM CEST, andrew@lunn.ch wrote:

quoted

quoted

I see this overlaps a lot with DPIPE. Why won't you use that to expose
your hw state?

We took a look at dpipe and i talked to you about using it for this
sort of thing at netconf/netdev. But dpipe has issues displaying the
sort of information we have. I never figured out how to do two
dimensional tables. The output of the dpipe command is pretty
unreadable. A lot of the information being dumped here is not about
the data pipe, etc.

So improve it. No problem. Also, we extend it to support what you neede.

Will i did try to do this back in March. And i failed.

Lets start with stats. Vivien gives an example on the cover letter:

   # pr -mt switch0/port{5,6}/stats
   in_good_octets      : 0             in_good_octets      : 13824
   in_bad_octets       : 0             in_bad_octets       : 0
   in_unicast          : 0             in_unicast          : 0
   in_broadcasts       : 0             in_broadcasts       : 216
   in_multicasts       : 0             in_multicasts       : 0
   in_pause            : 0             in_pause            : 0
   in_undersize        : 0             in_undersize        : 0

This is what i tried to implement using dpipe. It is a simple two
dimensional table. First column is a string, second a u64. In debugfs
we have such a table per port. That fits with the hierarchy that each
port is a directory in debugfs. But it could also be implemented as
one table with N+1 columns, for N switch ports.

Andrew, we talked about this in Montreal. What I suggested then was for
port stats to introduce devlink port statistics. Then you can have stats
for all sorts of ports that don't have netlink instance associated,
including cpu port. It aligns.

How about you, or one of your team, implement that. It should be able
to use the dsa_loop driver, which is a simple dummy switch. But it
does have statistics counters for all ports. Florian or I can help you
get it running if needed.

This branch contains some of the basic plumbing code from my previous
attempt:

https://github.com/lunn/linux.git v4.11-rc4-net-next-dpipe

 Andrew