[4.1] 72435ed Disable Nagle's algorithm on the backend as well

[PÃ¥l Hermunn Johansen]

commit 72435ed0e9aa6c0e46f88e95f37af1ceb9e0bba0
Author: Federico G. Schwindt <fgsch at lodoss.net>
Date:   Sat Nov 19 23:29:22 2016 +0000

    Disable Nagle's algorithm on the backend as well
    
    Fixes #2134.

diff --git a/lib/libvarnish/vtcp.c b/lib/libvarnish/vtcp.c
index 83e33b4..62a9fb6 100644
--- a/lib/libvarnish/vtcp.c
+++ b/lib/libvarnish/vtcp.c
@@ -279,6 +279,7 @@ VTCP_connect(const struct suckaddr *name, int msec)
 	struct pollfd fds[1];
 	const struct sockaddr *sa;
 	socklen_t sl;
+	int val;
 
 	if (name == NULL)
 		return (-1);
@@ -296,6 +297,9 @@ VTCP_connect(const struct suckaddr *name, int msec)
 	if (msec != 0)
 		(void)VTCP_nonblocking(s);
 
+	val = 1;
+	AZ(setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &val, sizeof val));
+
 	i = connect(s, sa, sl);
 	if (i == 0)
 		return (s);