From: Vladimir Oltean <olteanv@xxxxxxxxx> Date: Tue, 25 Aug 2020 01:02:03 +0300 > Just my comment on patch 5/8 about netdev->tc_to_txq. There are 2 > distinct things about that: > - accessing struct net_device directly hurts the DSA model a little bit. > - I think there's some confusion regarding the use of netdev->tc_to_txq > itself. I don't think that's the right place to setup a VLAN PCP to > traffic class mapping. That's simply "what traffic class does each > netdev queue have". I would even go as far as say that Linux doesn't > support a VLAN PCP to TC mapping (similar to the DSCP to TC mapping > from the DCB ops) at all, except for the ingress-qos-map and > egress-qos-map of the 8021q driver, which can't be offloaded and don't > map nicely over existing hardware anyway (what hardware has an > ingress-qos-map and an egress-qos-map per individual VLAN?!). > Although I do really see the need for having a mapping between VLAN > PCP and traffic class, I would suggest Kurt to not expose this through > taprio/mqprio (hardcode the PCP mapping as 1-to-1 with TC, as other > drivers do), and let's try to come up separately with an abstraction > for that. Agreed, Kurt can you repost this series without the TAPRIO support for now since it's controversial and needs more discussion and changes? Thank you.
