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Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/statistics.rst | 57 |
1 files changed, 52 insertions, 5 deletions
diff --git a/Documentation/networking/statistics.rst b/Documentation/networking/statistics.rst index d490b535cd14..8e15bc98830b 100644 --- a/Documentation/networking/statistics.rst +++ b/Documentation/networking/statistics.rst @@ -4,16 +4,23 @@ Interface statistics ==================== +Overview +======== + This document is a guide to Linux network interface statistics. -There are two main sources of interface statistics in Linux: +There are three main sources of interface statistics in Linux: - standard interface statistics based on - :c:type:`struct rtnl_link_stats64 <rtnl_link_stats64>`; and + :c:type:`struct rtnl_link_stats64 <rtnl_link_stats64>`; + - protocol-specific statistics; and - driver-defined statistics available via ethtool. -There are multiple interfaces to reach the former. Most commonly used -is the `ip` command from `iproute2`:: +Standard interface statistics +----------------------------- + +There are multiple interfaces to reach the standard statistics. +Most commonly used is the `ip` command from `iproute2`:: $ ip -s -s link show dev ens4u1u1 6: ens4u1u1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000 @@ -34,7 +41,26 @@ If `-s` is specified once the detailed errors won't be shown. `ip` supports JSON formatting via the `-j` option. -Ethtool statistics can be dumped using `ethtool -S $ifc`, e.g.:: +Protocol-specific statistics +---------------------------- + +Some of the interfaces used for configuring devices are also able +to report related statistics. For example ethtool interface used +to configure pause frames can report corresponding hardware counters:: + + $ ethtool --include-statistics -a eth0 + Pause parameters for eth0: + Autonegotiate: on + RX: on + TX: on + Statistics: + tx_pause_frames: 1 + rx_pause_frames: 1 + +Driver-defined statistics +------------------------- + +Driver-defined ethtool statistics can be dumped using `ethtool -S $ifc`, e.g.:: $ ethtool -S ens4u1u1 NIC statistics: @@ -94,6 +120,17 @@ Identifiers via `ETHTOOL_GSTRINGS` with `string_set` set to `ETH_SS_STATS`, and values via `ETHTOOL_GSTATS`. User space should use `ETHTOOL_GDRVINFO` to retrieve the number of statistics (`.n_stats`). +ethtool-netlink +--------------- + +Ethtool netlink is a replacement for the older IOCTL interface. + +Protocol-related statistics can be requested in get commands by setting +the `ETHTOOL_FLAG_STATS` flag in `ETHTOOL_A_HEADER_FLAGS`. Currently +statistics are supported in the following commands: + + - `ETHTOOL_MSG_PAUSE_GET` + debugfs ------- @@ -130,3 +167,13 @@ user space trying to read them. Statistics must persist across routine operations like bringing the interface down and up. + +Kernel-internal data structures +------------------------------- + +The following structures are internal to the kernel, their members are +translated to netlink attributes when dumped. Drivers must not overwrite +the statistics they don't report with 0. + +.. kernel-doc:: include/linux/ethtool.h + :identifiers: ethtool_pause_stats |