[dpdk-dev] IXGBE error statistics

[Van Haaren, Harry]

> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Igor Ryzhov
> Hello everyone.

Hi Igor,

> Investigating IXGBE driver I found an mspdc counter (MAC Short Packet
> Discard). And I am wondering why this counter is not used in the calculation
> of total RX errors (ierrors field in rte_eth_stats structure). Is it already a part
> of another counter, for example, rlec (Receive Length Error)? Or is it a bug?

There has been a discussion on list recently involving ixgbe stats, and certain
packets triggering multiple stats registers - the datasheet doesn't mention
this could be the case for the mspdc register, I will research this issue and
get back to you.

> Another one question is about incompleteness of rte_eth_stats structure.
> IXGBE and other drivers have a lot of counters but only a part of them is
> represented in rte_eth_stats. Is there any valuable reasons for that or it's
> just not implemented?

The rte_eth_stats struct presents the most general statistics that every NIC exposes.
In 2.1, and extended statistics API was added which allows NICs to expose stats
that are unique to that NIC. Currently ixgbe is the only driver that has the xstats API
implemented, I am working on patches to implement the functionality for the other
Intel drivers.

As part of testing the xstats implementation for each driver, I can test the exact
behavior of the mspdc counter, and if it is mis-counted this should become clear.

Cheers, -Harry