On Wed, Jan 27, 2016 at 09:47:50PM +0100, Jesper Dangaard Brouer wrote: > Sum: 18.75 % => calc: 30.0 ns (sum: 30.0 ns) => Total: 159.9 ns > > To get around the cache-miss in eth_type_trans(), I created a > "icache-loop" in mlx5e_poll_rx_cq() and pull all RX-ring packets "out", > before calling eth_type_trans(), reducing cost to 2.45%. > > To mitigate the SLUB slowpath, I used my slab + SKB-napi bulk API . And > also tuned SLUB (with slub_nomerge slub_min_objects=128) to get bigger > slab-pages, thus bigger bulk opportunities. > > This helped a lot, I can now drop 12Mpps (12,088,767 => 82.7 ns).
great stuff. I think such batching loop will reduce the cost of eth_type_trans() for all use cases. Only unfortunate that it would need to be implemented in every driver, but there is only a handful that people care about in high performance setups, so I think it's worth getting this patch in for mlx5 and the other drivers will catch up.
