This patch aims to improve the throughput of the distributor library. It uses a similar handshake mechanism to the previous version of the library, in that bits are used to indicate when packets are ready to be sent to a worker and ready to be returned from a worker. One main difference is that instead of sending one packet in a cache line, it makes use of the 7 free spaces in the same cache line in order to send up to 8 packets at a time to/from a worker.
The flow matching algorithm has had significant re-work, and now keeps an array of inflight flows and an array of backlog flows, and matches incoming flows to the inflight/backlog flows of all workers so that flow pinning to workers can be maintained. Notes: Apps must now work in bursts, as up to 8 are given to a worker at a time For performance in matching, Flow ID's are 15-bits Original API (and code) is kept for backward compatibility Performance Gains 2.2GHz Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz 2 x XL710 40GbE NICS to 2 x 40Gbps traffic generator channels 64b packets separate cores for rx, tx, distributor 1 worker - 4.8x 4 workers - 2.9x 8 workers - 1.8x 12 workers - 2.1x 16 workers - 1.8x [PATCH v1 1/2] lib: distributor performance enhancements [PATCH v1 2/2] example: distributor app modified to use burstAPI