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- Add optimizing LRO wrapper which pre-sorts all incoming packets according to the hash type and flowid. This prevents exhaustion of the LRO entries due to too many connections at the same time. Testing using a larger number of higher bandwidth TCP connections showed that the incoming ACK packet aggregation rate increased from ~1.3:1 to almost 3:1. Another test showed that for a number of TCP connections greater than 16 per hardware receive ring, where 8 TCP connections was the LRO active entry limit, there was a significant improvement in throughput due to being able to fully aggregate more than 8 TCP stream. For very few very high bandwidth TCP streams, the optimizing LRO wrapper will add CPU usage instead of reducing CPU usage. This is expected. Network drivers which want to use the optimizing LRO wrapper needs to call "tcp_lro_queue_mbuf()" instead of "tcp_lro_rx()" and "tcp_lro_flush_all()" instead of "tcp_lro_flush()". Further the LRO control structure must be initialized using "tcp_lro_init_args()" passing a non-zero number into the "lro_mbufs" argument. - Make LRO statistics 64-bit. Previously 32-bit integers were used for statistics which can be prone to wrap-around. Fix this while at it and update all SYSCTL's which expose LRO statistics. - Ensure all data is freed when destroying a LRO control structures, especially leftover LRO entries. - Reduce number of memory allocations needed when setting up a LRO control structure by precomputing the total amount of memory needed. - Add own memory allocation counter for LRO. - Bump the FreeBSD version to force recompilation of all KLDs due to change of the LRO control structure size. Sponsored by: Mellanox Technologies Reviewed by: gallatin, sbruno, rrs, gnn, transport Tested by: Netflix Differential Revision: https://reviews.freebsd.org/D4914
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