Linux ethtool Statistics

Alveo X3522 User Guide (UG1523)

Document ID
UG1523
Release Date
2023-08-25
Revision
1.4 English

The Linux command ethtool will display an extensive range of statistics originated from the MAC on the X3522 network adapter. To display statistics use the following command:

ethtool -S <interface>

(where <interface> is the X3522 interface)

X3522 net drivers have to manage multi-PF configurations and for this reason statistics are not reset by reloading the driver. The only methods currently available to reset stats is to cold-reboot (power OFF/ON) the server or reload the firmware image.

Per port statistics (port_) are from the physical adapter port. Other statistics are from the specified PCIe function.

The following table lists the complete output from the ethtool -S command.

Note: ethtool -S output depends on the features supported by the adapter type.
Table 1. Ethtool -S Output
Field Description
rx_drops Total number of received packets dropped by the net driver. This includes the following counters:
  • rx_mcast_mismatch
  • rx_alloc_skb_fail
  • rx_broadcast_drop
  • rx_other_host_drop
tx_drops Total number of transmitted packets dropped by the net driver.
port_tx_pause Number of pause frames transmitted with valid pause op_code.
port_tx_unicast Number of unicast packets transmitted. Includes flow control packets.
port_tx_multicast Number of multicast packets transmitted.
port_tx_broadcast Number of broadcast packets transmitted.
port_tx_lt64 Number of frames transmitted where the length is less than 64 bytes.
port_tx_64 Number of frames transmitted where the length is exactly 64 bytes.
port_tx_65_to_127 Number of frames transmitted where the length is between 65 and 127 bytes.
port_tx_128_to_255 Number of frames transmitted where the length is between 128 and 255 bytes.
port_tx_256_to_511 Number of frames transmitted where the length is between 256 and 511 bytes.
port_tx_512_to_1023 Number of frames transmitted where length is between 512 and 1023 bytes.
port_tx_1024_to_15xx Number of frames transmitted where the length is between 1024 and 1518 bytes (1522 with VLAN tag).
port_tx_15xx_to_jumbo Number of frames transmitted where length is between 1518 bytes (1522 with VLAN tag) and 9000 bytes.
port_rx_good Number of packets received with correct CRC value and no error codes.
port_rx_bad Number of packets received with incorrect CRC value.
port_rx_bad_bytes Number of bytes with invalid FCS. Includes bytes from packets that exceed the maximum frame length.
port_rx_pause Number of pause frames received with valid pause op_code.
port_rx_unicast Number of unicast packets received.
port_rx_multicast Number of multicast packets received.
port_rx_broadcast Number of broadcasted packets received.
port_rx_lt64 Number of packets received where the length is less than 64 bytes.
port_rx_64 Number of packets received where the length is exactly 64 bytes.
port_rx_65_to_127 Number of packets received where the length is between 65 and 127 bytes.
port_rx_128_to_255 Number of packets received where the length is between 128 and 255 bytes.
port_rx_256_to_511 Number of packets received where the length is between 256 and 511 bytes.
port_rx_512_to_1023 Number of packets received where the length is between 512 and 1023 bytes.
port_rx_1024_to_15xx Number of packets received where the length is between 1024 and 1518 bytes (1522 with VLAN tag).
port_rx_15xx_to_jumbo Number of packets received where the length is between 1518 bytes (1522 with VLAN tag) and 9000 bytes.
port_rx_gtjumbo Number of packets received with a length is greater than 9000 bytes.
port_rx_bad_gtjumbo Number of packets received with a length greater than 9000 bytes, but with incorrect CRC value.
port_rx_align_error Number of packets received with an align error.
port_rx_length_error Number of packets received with a length error.

port_rx_nodesc_drops

Number of packets dropped by the network adapter because of a lack of RX descriptors in the RX queue.

Packets can be dropped by the NIC when there are insufficient RX descriptors in the RX queue to allocate to the packet. This problem occurs if the receive rate is very high and the network adapter receive cycle process has insufficient time between processing to refill the queue with new descriptors.

A number of different steps can be tried to resolve this issue:

  • Disable the irqbalance daemon in the OS
  • Distribute the traffic load across the available CPU/cores by setting rss_cpus=cores. Refer to Receive Side Scaling section
  • Increase receive queue size using ethtool.
port_pm_discard_vfifo_full Count of the number of packets dropped because of a lack of main packet memory on the adapter to receive the packet into.
port_rxdp_q_disabled_packets Increments when the filter indicates the packet should be delivered to a specific RX queue which is currently disabled due to configuration error or error condition.
port_rxdp_di_dropped_packets

Number of packets dropped because the filters indicate the packet should be dropped. Can happen because:

  • the packet does not match any filter.
  • the matched filter indicates the packet should be dropped.
port_ctpio_underflow_fail

When the host fails to push packet bytes fast enough to match the adapter port speed.

The packet is truncated and data transmitted as a poisoned packet.

port_ctpio_success Number of successful CTPIO TX events.
ptp_invalid_sync_windows Number of times that the PTP window (pre and post time sample) is unexpectedly large.
ptp_skipped_sync Number of times that PTP synchronization is skipped due to repeated invalid_sync_windows.
ptp_tx_dropped_timestamp Number of transmitted PTP packets dropped because of timestamp.
pps_fw Number of PPS pulses received from firmware.
pps_in_count Number of external PPS pulses received.
pps_in_offset_mean Mean offset of the PPS pulse from the adapter clock, in nanoseconds.
pps_in_offset_last Last offset of the PPS pulse from the adapter clock, in nanoseconds.
pps_in_offset_max Maximum offset of the PPS pulse from the adapter clock, in nanoseconds.
pps_in_offset_min Minimum offset of the PPS pulse from the adapter clock, in nanoseconds.
pps_in_period_mean Mean period between successive PPS pulses, in nanoseconds.
pps_in_period_last Last period between successive PPS pulses, in nanoseconds.
pps_in_period_max Maximum period between successive PPS pulses, in nanoseconds.
pps_in_period_min Minimum period between successive PPS pulses, in nanoseconds.
pps_in_bad Number of bad PPS periods.
pps_in_oflow Number of PPS overflows.
tx_stop_queue Number of times the transmit queue has been stopped because space was not available.
evq_time_sync_events Number of time sync events received.
evq_error_events Number of error events received.
evq_flush_events Number of flush events received.
evq_unsol_overflow Number of times event queue has run out of unsolicited credits.
evq_unhandled_events Number of unhandled events received.
rx_ip_hdr_chksum_err Number of packets received with IP header checksum errors.
rx_tcp_udp_chksum_err Number of packets received with TCP/UDP checksum errors.
rx_mcast_mismatch Number of unsolicited multicast packets received. Unwanted multicast packets can be received because a connected switch simply broadcasts all packets to all endpoints or because the connected switch is not able or not configured for IGMP snooping – a process from which it learns which endpoints are interested in which multicast streams.
rx_merge_events Number of RX completion events where more than one RX descriptor was completed.
rx_merge_packets Number of packets delivered to the host through merge events.
rx_alloc_skb_fail Number of times allocating a socket buffer to receive packets has failed.
rx_broadcast_drop Number of received broadcast packets that have been dropped.
rx_other_host_drop Number of received packets dropped because the MAC address does not match any MAC filter of the interface.
rx_nbl_empty Number of times an RX packet event is received but the network buffer list is empty.
rx_buffers_posted Number of super buffers that have been posted to receive packets.
rx_rollover_events Number of times that a rollover event has been received.
rx_aux_pkts Number of packets handled by the auxiliary device.
tx-<n>.tx_packets Per TX queue transmitted packets.
rx-<n>.rx_packets Per RX queue received packets.