On Mon, Jun 01, 2015 at 01:49:30PM -0700, Jesse Gross wrote: > We have a special flow_metadata structure to represent the parts > of a packet that aren't carried in the payload itself. This is > used in the case where we need to send the packet as a Packet In > to an OpenFlow controller. This is a subset of the more general > struct flow. > > In practice, almost all operations we do on this structure involve > converting it to or from a match or have code that is the same as > a match. Serialization to NXM and back is done as a match. There > is special flow_metadata formatting code that is almost identical > to match formatting. > > The uses for struct flow_metadata aren't performance critical > when it comes to memory, so we can save quite a bit of code by > just using a match structure directly instead. In addition, as > metadata increases and becomes more complex (Geneve options require > some special handling beyond just additional fields), using the > match structure means we only have to do this work in one place. > > Signed-off-by: Jesse Gross <je...@nicira.com>
Most of this rationale makes sense to me, except that I'm surprised that struct flow_metadata (which doesn't have masks) gets converted to struct match (which does). Maybe I should just dig into the code, but is there some big reason why this is the case? _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
