On Mon, Dec 21, 2015 at 11:38:33PM -0800, Ben Pfaff wrote: > On Mon, Nov 30, 2015 at 10:03:11AM -0800, Jarno Rajahalme wrote: > > > > > On Nov 29, 2015, at 17:12, Ben Pfaff <b...@ovn.org> wrote: > > > > > >> On Mon, Nov 23, 2015 at 08:54:31PM -0800, Jarno Rajahalme wrote: > > >> Back by popular demand, here is the OpenFlow meter implementation for > > >> the userspace datapath. Meters are inherently shared datapath > > >> resources and this version uses a simple locking strategy which may > > >> not be optimal for DPDK. Nonetheless, this implementation should be a > > >> good starting point for further optimizations. > > > > > > OF1.5 has "drop" and "DSCP remark" meters. It looks like this initial > > > implementation has only "drop" meters. Is it general enough that DSCP > > > remarking meters could be supported later within the framework? > > > > It should be, as remarking the packet is similar to a set action, but > > drop meter requires the support for an datapath action dropping a > > packet, which did not exist before. > > OK. > > The "meter" action as implemented by this series seems to be a "global" > action, like "exit": if the meter drops the packet, then no later > (datapath) action is executed. But I think that would be surprising > behavior: I would expect actions higher up on the control stack > (e.g. from earlier "resubmit"s) to still get executed. Did you consider > any other techniques that could support that? > > OpenFlow doesn't have much of a control stack, so it doesn't define this > precisely, but OpenFlow 1.5 supports "egress tables" which have similar > behavior: when a packet is output to a port like OFPP_FLOOD that > actually corresponds to multiple ports, it passes separately through the > egress tables for each of those ports, once for each of them. The > egress tables are allowed to use "meter" actions to drop packets, and > although OpenFlow doesn't say so explicitly, I don't think it would make > sense for this to drop every packet (or maybe just the ones that come > later in processing order? (but the processing might happen in parallel > anyway since it's hardware?)), instead of just the one egressing packet.
Do you have any thoughts? It *would* be nice to get meters working, since users sometimes ask about them. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
