2017-08-14 13:51 GMT+03:00 Bruce Richardson <bruce.richard...@intel.com>:
> On Tue, Jul 11, 2017 at 07:33:04PM +0000, Medvedkin Vladimir wrote: > > Hi, > > > > I want to introduce new library for ip routing lookup that have some > advantages > > over current LPM library. In short: > > - Increases the speed of control plane operations against lpm such > as > > adding/deleting routes > > - Adds abstraction from dataplane algorythms, so it is possible to > add > > different ip route lookup algorythms such as > DXR/poptrie/lpc-trie/etc > > in addition to current dir24_8 > > - It is possible to keep user defined application specific > additional > > information in struct rte_rib_v4_node which represents route > entry. > > It can be next hop/set of next hops (i.e. active and feasible), > > pointers to link rte_rib_v4_node based on some criteria (i.e. > next_hop), > > plenty of additional control plane information. > > - For dir24_8 implementation it is possible to remove > rte_lpm_tbl_entry.depth > > field that helps to save 6 bits. > > - Also new dir24_8 implementation supports different next_hop sizes > > (1/2/4/8 bytes per next hop) > > > > It would be nice to hear your opinion. The draft is below. > > > > Medvedkin Vladimir (1): > > lib/rib: Add Routing Information Base library > > > > On reading this patch and then having discussion with you offline, it > appears there are two major new elements in this patchset: > > 1. a re-implementation of LPM, with the major advantage of having a > flexible data-size > 2. a separate control plane structure that is designed to fit on top off > possibly multiple lookup structures for the data plane > > Is this correct? > Correct > > For the first part, I don't think we should carry about two separate LPM > implementations, but rather look to take the improvements in your > version back into the existing lib. [Or else replace the existing one, > but I prefer pulling the new stuff into it, so as to keep backward > compatibility] > > For the second part, perhaps you could expand a bit more on the thought > here, and explain what all different data plane implementations would > fit under it. Would, for instance a hash-lookup work? In that case, what > would the data plane APIs be, and the control plane ones. > I'm not sure for _all_ data plane implementations, but from my point of view compressed prefix trie (rte_rib structure) could be useful at least for dir24_8, dxr, bitmap handling. Concerning to hash lookup, it depends on algorithm (array of hash tables indexed by mask length, unrolling prefix to number of /32). Perhaps it is better to waive the abstraction and make LPM as primary struct that keeps rte_rib inside (instead of rules_tbl[ ]). In that case rte_rib becomes side structure and it's API only for working with a trie. LPM's API remains the same (except next_hop size and LPM creation). > Thanks, > /Bruce > -- Regards, Vladimir
