Re: [PATCH net-next 0/9] ethtool: add uAPI for reading standard stats

On Thu, Apr 15, 2021 at 07:27:43PM -0700, Jakub Kicinski wrote:

Continuing the effort of providing a unified access method
to standard stats, and explicitly tying the definitions to
the standards this series adds an API for general stats
which do no fit into more targeted control APIs.

There is nothing clever here, just a netlink API for dumping
statistics defined by standards and RFCs which today end up
in ethtool -S under infinite variations of names.

This series adds basic IEEE stats (for PHY, MAC, Ctrl frames)
and RMON stats. AFAICT other RFCs only duplicate the IEEE
stats.

This series does _not_ add a netlink API to read driver-defined
stats. There seems to be little to gain from moving that part
to netlink.

The netlink message format is very simple, and aims to allow
adding stats and groups with no changes to user tooling (which
IIUC is expected for ethtool).

On user space side we can re-use -S, and make it dump
standard stats if --groups are defined.

Jakub, do you have a link for the user space patches? I would like to
test it with mlxsw given you already patched it (thanks!).

$ ethtool -S eth0 --groups eth-phy eth-mac eth-ctrl rmon

Given that you have now standardized these stats, do you plan to feed
them into some monitoring system? For example, Prometheus has an ethtool
exporter [1] and now I see that support is also being added to
node_exporter [2] where it really belongs. They obviously mentioned [3]
the problem with lack of standardization: "There is also almost no
standardization, so if you use multiple network card vendors, you have
to examine the data closely to find out what is useful to you and set up
your alerts and dashboards accordingly."

[1] https://github.com/Showmax/prometheus-ethtool-exporter
[2] https://github.com/prometheus/node_exporter/pull/1832
[3] https://tech.showmax.com/2018/11/scraping-ethtool-data-into-prometheus/

Stats for eth0:
eth-phy-SymbolErrorDuringCarrier: 0
eth-mac-FramesTransmittedOK: 0
eth-mac-FrameTooLongErrors: 0
eth-ctrl-MACControlFramesTransmitted: 0
eth-ctrl-MACControlFramesReceived: 1
eth-ctrl-UnsupportedOpcodesReceived: 0
rmon-etherStatsUndersizePkts: 0
rmon-etherStatsJabbers: 0
rmon-rx-etherStatsPkts64Octets: 1
rmon-rx-etherStatsPkts128to255Octets: 0
rmon-rx-etherStatsPkts1024toMaxOctets: 1
rmon-tx-etherStatsPkts64Octets: 1
rmon-tx-etherStatsPkts128to255Octets: 0
rmon-tx-etherStatsPkts1024toMaxOctets: 1

v1:

Driver support for mlxsw, mlx5 and bnxt included.

Compared to the RFC I went ahead with wrapping the stats into
a 1:1 nest. Now IDs of stats can start from 0, at a cost of
slightly "careful" u64 alignment handling.

Jakub Kicinski (9):
  docs: networking: extend the statistics documentation
  docs: ethtool: document standard statistics
  ethtool: add a new command for reading standard stats
  ethtool: add interface to read standard MAC stats
  ethtool: add interface to read standard MAC Ctrl stats
  ethtool: add interface to read RMON stats
  mlxsw: implement ethtool standard stats
  bnxt: implement ethtool standard stats
  mlx5: implement ethtool standard stats

 Documentation/networking/ethtool-netlink.rst  |  74 ++++
 Documentation/networking/statistics.rst       |  44 +-
 .../net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 125 ++++++
 .../ethernet/mellanox/mlx5/core/en_ethtool.c  |  37 ++
 .../ethernet/mellanox/mlx5/core/en_stats.c    | 142 +++++-
 .../ethernet/mellanox/mlx5/core/en_stats.h    |  10 +
 .../mellanox/mlxsw/spectrum_ethtool.c         | 129 ++++++
 include/linux/ethtool.h                       |  95 ++++
 include/uapi/linux/ethtool.h                  |  10 +
 include/uapi/linux/ethtool_netlink.h          | 137 ++++++
 net/ethtool/Makefile                          |   2 +-
 net/ethtool/netlink.c                         |  10 +
 net/ethtool/netlink.h                         |   8 +
 net/ethtool/stats.c                           | 410 ++++++++++++++++++
 net/ethtool/strset.c                          |  25 ++
 15 files changed, 1248 insertions(+), 10 deletions(-)
 create mode 100644 net/ethtool/stats.c

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2.30.2