​ice Counters

The ice driver provides a long list of counters for interface debug and monitoring through the ethtool -S ethX command. It can be helpful to watch the output while a workload is running and/or compare the counter values before and after a workload run.

When debugging performance issues it is often helpful to compare the output of these counters before and after running a workload.

• ​​To get a full dump of ice counters: ethtool -S ethX
• ​​To watch just non-zero counters: watch -d ethtool -S ethX | egrep -v :\ 0 | column

Some things to look for:

• ​​rx_​dropped means CPU not servicing buffers fast enough.
• ​​rx_​dropped.nic can indicate that resource limitations in the slot/memory/system.

Check netstat -s before/after a workload run.

The netstat tool collects network information from all network devices in the system, so results might be impacted from other networks other than your network under test. However, the output from netstat -s can be a good indicator of performance issues in the Linux operating system or kernel.

Consult operating system tuning guides, such as the Red Hat Enterprise Linux Network Performance Tuning Guide, for more insight on general operating system tuning: