• Jason Wang's avatar
    virtio-net: coalesce rx frags when possible during rx · ba275241
    Jason Wang authored
    Commit 2613af0e (virtio_net: migrate mergeable
    rx buffers to page frag allocators) try to increase the payload/truesize for
    MTU-sized traffic. But this will introduce the extra overhead for GSO packets
    received because of the frag list. This commit tries to reduce this issue by
    coalesce the possible rx frags when possible during rx. Test result shows the
    about 15% improvement on full size GSO packet receiving (and even better than
    before commit 2613af0e).
    
    Before this commit:
    ./netperf -H 192.168.100.4
    MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.100.4
    () port 0 AF_INET : demo
    Recv   Send    Send
    Socket Socket  Message  Elapsed
    Size   Size    Size     Time     Throughput
    bytes  bytes   bytes    secs.    10^6bits/sec
    
     87380  16384  16384    10.00    20303.87
    
    After this commit:
    ./netperf -H 192.168.100.4
    MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.100.4
    () port 0 AF_INET : demo
    Recv   Send    Send
    Socket Socket  Message  Elapsed
    Size   Size    Size     Time     Throughput
    bytes  bytes   bytes    secs.    10^6bits/sec
    
     87380  16384  16384    10.00    23841.26
    
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Cc: Michael S. Tsirkin <mst@redhat.com>
    Cc: Michael Dalton <mwdalton@google.com>
    Cc: Eric Dumazet <edumazet@google.com>
    Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
    Acked-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
    Acked-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    ba275241
virtio_net.c 45.7 KB