> On 24 Jan 2019, at 11:16, Damjan Marion via Lists.Fd.Io > <dmarion=me....@lists.fd.io> wrote: > > > >> On 24 Jan 2019, at 10:39, Benoit Ganne (bganne) via Lists.Fd.Io >> <bganne=cisco....@lists.fd.io> wrote: >> >> Hi all, >> >> While refactoring the GBP plugin to use feature arcs instead of hardcoded L2 >> feature bits, I had to basically duplicate my feature arc nodes 3x (and >> disable/enable them 3x etc.) because the L2 feature arcs are divided in 3 >> flavors: nonip (no IP ethertype), ip4 (IPv4 ethertype) and ip6 (IPv6 >> ethertype). It works but I'd prefer to hide this complexity from the plugins. >> I can see several possibilities: >> 1) add a new feature arc flavor 'all' alongside nonip, ip4 and ip6. Nodes on >> this arc will gets all packets regardless of the headers. It keeps backward >> compat but should add a small performance hit when L2 feature arcs are >> enabled (we have to visit 4 feature arcs instead of 3). This is my favorite. > > How this works if you have features enabled on both all and ip4 for example? > >> 2) remove feature arcs flavors and just pass all packets to feature nodes. >> It is the responsibility of the nodes to check the packet type. It >> simplifies the L2 feature arc code but breaks backward compat. It could also >> be slightly less efficient as the ethertype test will happen later and must >> be duplicating in all feature nodes.
Exactly the reason why I did it this way and why I would not go that route. >> 3) add a new feature arc using a new feature bit. It does not modify the >> current path at all, so perf & compat is unchanged but adds some complexity >> in the L2 path. >> 4) keeps the 3 flavors as they are but add helper to register nodes to the 3 >> arcs - basically move helpers from GBP plugin to vnet/l2. Basically same >> up/downside as (3) This would be my favourite approach. The benefit of having per-arc nodes is that we can get compiler optimizations by using constant propagation of “is_ip6” parameter to a common inline node function... overhead in total is about 20 LOC per node, and is a one-time thing. —a >> 5) keep it as is (boilerplate in GBP) >> >> My favorite would be (1) but I'd like to hear from more experience VPP dev. > > > I would say 2, but that's just my 2 cents... > > -- > Damjan > > -=-=-=-=-=-=-=-=-=-=-=- > Links: You receive all messages sent to this group. > > View/Reply Online (#11987): https://lists.fd.io/g/vpp-dev/message/11987 > Mute This Topic: https://lists.fd.io/mt/29523811/675608 > Group Owner: vpp-dev+ow...@lists.fd.io > Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [ayour...@gmail.com] > -=-=-=-=-=-=-=-=-=-=-=-
-=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#11992): https://lists.fd.io/g/vpp-dev/message/11992 Mute This Topic: https://lists.fd.io/mt/29523811/21656 Group Owner: vpp-dev+ow...@lists.fd.io Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
