• Eric Dumazet's avatar
    tcp: implement coalescing on backlog queue · 4f693b55
    Eric Dumazet authored
    In case GRO is not as efficient as it should be or disabled,
    we might have a user thread trapped in __release_sock() while
    softirq handler flood packets up to the point we have to drop.
    This patch balances work done from user thread and softirq,
    to give more chances to __release_sock() to complete its work
    before new packets are added the the backlog.
    This also helps if we receive many ACK packets, since GRO
    does not aggregate them.
    This patch brings ~60% throughput increase on a receiver
    without GRO, but the spectacular gain is really on
    1000x release_sock() latency reduction I have measured.
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Cc: Neal Cardwell <ncardwell@google.com>
    Cc: Yuchung Cheng <ycheng@google.com>
    Acked-by: default avatarNeal Cardwell <ncardwell@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
proc.c 19.9 KB