Re: TC stats / hw offload question

Edward Cree
2019-02-08T10:27:01Z

On 06/02/19 02:20, Jamal Hadi Salim wrote:
> The classifiers dont mod the packets. The actions do. And they
> maintain stats on the size on "entry" i.e pre-edit.
Thank you for clearing that up.

> Each action keeps its own counters. If you did something like:
>
> tc match using flower blah \
> action vlan push tag ... \
> action redirect to egress of eth0
>
> And you submited a packet of size x bytes,
> then the "match" would record x bytes.
Sorry, where would it record that?  I can't find any stats counters on
the "match" either in the software path or the offload API.

> the "vlan action" would record x bytes.
> the "redirect" would record size x+vlaninfo bytes
> the egress of eth0 would  recorr x+vlaninfo bytes
Am I right in thinking that offloaded counters don't do that?  As far
as I can tell, the drivers with flower offload all use
tcf_exts_stats_update() which takes a single 'bytes' count and adds
it to all the actions.  (Presumably this is pre-edit length.)

-Ed