For memif non-zero-copy mode, there is a branch to compare the mbuf and memif buffer size during memory copy. Add a fast memcpy path by removing this branch with mbuf and memif buffer size defined at compile time. For Rx fast path, bulk allocating mbufs to get additional speedup. For Tx fast path, bulk free mbufs which come from the same mempool.
When mbuf == memif buffer size, both Rx/Tx would choose the fast memcpy path. When mbuf < memif buffer size, the Rx chooses previous memcpy path while Tx chooses fast memcpy path. When mbuf > memif buffer size, the Rx chooses fast memcpy path while Tx chooses previous memcpy path. Test with 1p1q on N1SDP AArch64 server, --------------------------------------------------------- buf size | memif = mbuf | memif < mbuf | memif > mbuf --------------------------------------------------------- non-zc gain | 47.16% | 24.67% | 12.47% --------------------------------------------------------- zc gain | 20.96% | 9.16% | 10.66% --------------------------------------------------------- Test with 1p1q on Cascade Lake Xeon X86 server, --------------------------------------------------------- buf size | memif = mbuf | memif < mbuf | memif > mbuf --------------------------------------------------------- non-zc gain | 23.52% | 14.20% | 5.10% --------------------------------------------------------- zc gain | 17.49% | 10.62% | 12.42% --------------------------------------------------------- v3: Add bulk allocation to get additional speedup for memif Rx fast path. <Stephen Hemminger> v2: Rebase v1 and update commit message. Joyce Kong (2): net/memif: add a Rx fast path net/memif: add a Tx fast path drivers/net/memif/rte_eth_memif.c | 271 +++++++++++++++++++++--------- 1 file changed, 188 insertions(+), 83 deletions(-) -- 2.25.1
