Reduce -netdev socket latency by disabling the Nagle algorithm on
SOCK_STREAM sockets in net/socket.c. Since we are tunelling Ethernet
over TCP we shouldn't artificially delay outgoing packets, let the guest
decide packet scheduling.
I already get sub-millisecond -netdev socket ping times on localhost, so
there was no measurable difference in my testing. This won't hurt
though and may improve remote socket performance.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
net/socket.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/socket.c b/net/socket.c
index 396dc8c..c0dcc31 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -439,6 +439,9 @@ static NetSocketState
*net_socket_fd_init_stream(NetClientState *peer,
s->fd = fd;
s->listen_fd = -1;
+ /* Disable Nagle algorithm on TCP sockets to reduce latency */
+ socket_set_nodelay(fd);
+
if (is_connected) {
net_socket_connect(s);
} else {
--
1.8.1.2
