[PATCH net-next 1/9] docs: networking: extend the statistics documentation
From: Jakub Kicinski <kuba@kernel.org>
Date: 2021-04-16 02:27:57
Subsystem:
documentation, networking [general], the rest · Maintainers:
Jonathan Corbet, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Make the lack of expectations for switching NICs explicit, describe the new stats. Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- Documentation/networking/statistics.rst | 44 +++++++++++++++++++++++-- 1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/Documentation/networking/statistics.rst b/Documentation/networking/statistics.rst
index b748fe44ee02..5aaa66bba971 100644
--- a/Documentation/networking/statistics.rst
+++ b/Documentation/networking/statistics.rst@@ -44,8 +44,27 @@ If `-s` is specified once the detailed errors won't be shown. Protocol-specific statistics ---------------------------- -Some of the interfaces used for configuring devices are also able -to report related statistics. For example ethtool interface used +Protocol-specific statistics are exposed via relevant interfaces, +the same interfaces used to configure them. + +ethtool +~~~~~~~ + +Ethtool exposes common low-level statistics. +All the standard statistics are expected to be maintained +by the device, not the driver (as opposed to driver-defined stats +described in the next section which mix software and hardware stats). +For devices which contain unmanaged +switches (e.g. legacy SR-IOV or multi-host NICs) the events counted +may not pertain exclusively to the packets destined to +the local host interface. In other words the events may +be counted at the network port (MAC/PHY blocks) without separation +for different host side (PCIe) devices. Such ambiguity must not +be present when internal switch is managed by Linux (so called +switchdev mode for NICs). + +Standard ethtool statistics can be accessed via the interfaces used +for configuration. For example ethtool interface used to configure pause frames can report corresponding hardware counters:: $ ethtool --include-statistics -a eth0
@@ -57,6 +76,27 @@ to report related statistics. For example ethtool interface used tx_pause_frames: 1 rx_pause_frames: 1 +General Ethernet statistics not associated with any particular +functionality are exposed via ``ethtool -S $ifc`` by specifying +the ``--groups`` parameter:: + + $ ethtool -S eth0 --groups eth-phy eth-mac eth-ctrl rmon + Stats for eth0: + eth-phy-SymbolErrorDuringCarrier: 0 + eth-mac-FramesTransmittedOK: 1 + eth-mac-FrameTooLongErrors: 1 + eth-ctrl-MACControlFramesTransmitted: 1 + eth-ctrl-MACControlFramesReceived: 0 + eth-ctrl-UnsupportedOpcodesReceived: 1 + rmon-etherStatsUndersizePkts: 1 + rmon-etherStatsJabbers: 0 + rmon-rx-etherStatsPkts64Octets: 1 + rmon-rx-etherStatsPkts65to127Octets: 0 + rmon-rx-etherStatsPkts128to255Octets: 0 + rmon-tx-etherStatsPkts64Octets: 2 + rmon-tx-etherStatsPkts65to127Octets: 3 + rmon-tx-etherStatsPkts128to255Octets: 0 + Driver-defined statistics -------------------------
--
2.30.2