Re: [PATCH net-next 1/2] net: AF-specific RTM_GETSTATS attributes

[Roopa Prabhu <roopa@cumulusnetworks.com>]

On 1/13/17, 10:14 AM, Robert Shearman wrote:
> Add the functionality for including address-family-specific per-link
> stats in RTM_GETSTATS messages. This is done through adding a new
> IFLA_STATS_AF_SPEC attribute under which address family attributes are
> nested and then the AF-specific attributes can be further nested. This
> follows the model of IFLA_AF_SPEC on RTM_*LINK messages and it has the
> advantage of presenting an easily extended hierarchy. The rtnl_af_ops
> structure is extended to provide AFs with the opportunity to fill and
> provide the size of their stats attributes.
>
> One alternative would have been to provide AFs with the ability to add
> attributes directly into the RTM_GETSTATS message without a nested
> hierarchy. I discounted this approach as it increases the rate at
> which the 32 attribute number space is used up and it makes
> implementation a little more tricky for stats dump resuming (at the
> moment the order in which attributes are added to the message has to
> match the numeric order of the attributes).
>
> Another alternative would have been to register per-AF RTM_GETSTATS
> handlers. I discounted this approach as I perceived a common use-case
> to be getting all the stats for an interface and this approach would
> necessitate multiple requests/dumps to retrieve them all.
>
> Signed-off-by: Robert Shearman <rshearma@brocade.com>
>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>