Re: [PATCH net-next 3/5] ethtool: add interface to read representor Rx statistics

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 4 Apr 2024 20:33:55 +0300 Tariq Toukan wrote:
> Implement common representor port statistics in
> a rep_port_stats struct_group, introducing a new
> 'out of buffer' stats for when packets are dropped
> due to a lack of receive buffers in RX queue.
> 
> The port statistics represent the statistics of the
> function with which the representor is associated.
> 
> Print the representor port stats when the
> --groups rep-port or --all-groups are used.

I re-read what Tariq said on v1 and I clearly missed the point,
sorry about that. Looking that his patch makes it pretty obvious.

With the netdev netlink family in place I was hoping we would
only put in ethtool stats for functionality already configured
via ethtool or clearly related to Ethernet.

But before we go to netdev - can you think of more such error stats 
that we may need to add? Since it's the equivalent of rtnl rx_missed 
I think we should consider putting it in netdev_offload_xstats. Maybe
following the same definition as packet/byte counters? Report sum by
default and CPU ones under IFLA_OFFLOAD_XSTATS_CPU_HIT? Or new enum
entry?

Simon, WDYT?

> +/**
> + * struct ethtool_rep_port_stats - representor port statistics
> + * @rep_port_stats: struct group for representor port

In more trivial remarks - kernel-doc script apparently doesn't want
the group to be documented (any more?)

> + *	@out_of_buf: Number of packets were dropped due to buffer exhaustion.
> + */
> +struct ethtool_rep_port_stats {
> +	struct_group(rep_port_stats,
> +		u64 out_of_buf;
> +	);
> +};
> +