Subject: Re: [PATCH net-next v2 00/10] net: dsa: add generic debugfs interface
To: Andrew Lunn <andrew@lunn.ch>, Jiri Pirko <jiri@resnulli.us>
References: <20170828191748.19492-1-vivien.didelot@savoirfairelinux.com>
 <20170828195332.GB1950@nanopsycho.orion> <20170828200834.GA1870@lunn.ch>
 <20170829062523.GA1977@nanopsycho.orion> <20170829125004.GB22093@lunn.ch>
Cc: Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel@savoirfairelinux.com, "David S. Miller" <davem@davemloft.net>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Egil Hjelmeland <privat@egil-hjelmeland.no>,
        John Crispin <john@phrozen.org>,
        Woojung Huh <Woojung.Huh@microchip.com>,
        Sean Wang <sean.wang@mediatek.com>,
        Nikita Yushchenko <nikita.yoush@cogentembedded.com>,
        Chris Healy <cphealy@gmail.com>, mlxsw@mellanox.com
From: Arkadi Sharshevsky <arkadis@mellanox.com>
Message-ID: <8e6fa7ea-fb7b-3026-b9c0-417ef2efae27@mellanox.com>
Date: Tue, 29 Aug 2017 22:05:11 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.8.0
MIME-Version: 1.0
In-Reply-To: <20170829125004.GB22093@lunn.ch>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
SpamDiagnosticOutput: 1:99
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Aug 2017 19:05:16.2799
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0501MB2463
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 2748
Lines: 61


On 08/29/2017 03:50 PM, Andrew Lunn wrote:
> On Tue, Aug 29, 2017 at 08:25:23AM +0200, Jiri Pirko wrote:
>> Mon, Aug 28, 2017 at 10:08:34PM CEST, andrew@lunn.ch wrote:
>>>> 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.
>

Hi Andrew,

This looks to me like basic L2 statistics that are obtained via
ethtool, I remember you had this problem with the DSA and CPU port.
Is this still the case?

I remembered we wanted to use dpipe for the DSA routing table
and IP priority table.

I think both those processes really look like match/action table
, thus they can be modeled successfully by dpipe.

> 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://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Flunn%2Flinux.git&data=02%7C01%7Carkadis%40mellanox.com%7Cb3cac139af204f79259c08d4eedc8410%7Ca652971c7d2e4d9ba6a4d149256f461b%7C0%7C0%7C636396078291326351&sdata=K5D3TAb2spckuF5k88oOaVt0dmtHj0AwE8bEEGPPdGI%3D&reserved=0 v4.11-rc4-net-next-dpipe
> 
> 	 Andrew
>