Disable the Nagle algorithm to reduce latency. Note this means we must also use TCP_CORK when sending header followed by payload to avoid fragmenting lots of little packets. The previous patch took care of that.
Suggested-by: Nick Thomas <n...@bytemark.co.uk> Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com> --- block/nbd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/nbd.c b/block/nbd.c index 485bbf0..d9dc454 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -406,6 +406,9 @@ static int nbd_establish_connection(BlockDriverState *bs) sock = unix_socket_outgoing(qemu_opt_get(s->socket_opts, "path")); } else { sock = tcp_socket_outgoing_opts(s->socket_opts); + if (sock >= 0) { + socket_set_nodelay(sock); + } } /* Failed to establish connection */ -- 1.8.1.4