Author: stefan2
Date: Fri Oct 18 16:12:54 2013
New Revision: 1533530
URL: http://svn.apache.org/r1533530
Log:
Fix a major latency snafu in svnserve. Sequences of small requests
and responses would be delayed in the TCP/IP stack by Nagle's alogrithm.
That becomes obvious when e.g. running "ls -R".
* subversion/libsvn_ra_svn/marshal.c
(svn_ra_svn_create_conn3): send data as soon as write copy it from
our send buffers to the socket
Modified:
subversion/trunk/subversion/libsvn_ra_svn/marshal.c
Modified: subversion/trunk/subversion/libsvn_ra_svn/marshal.c
URL:
http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_ra_svn/marshal.c?rev=1533530&r1=1533529&r2=1533530&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_ra_svn/marshal.c (original)
+++ subversion/trunk/subversion/libsvn_ra_svn/marshal.c Fri Oct 18 16:12:54 2013
@@ -119,6 +119,16 @@ svn_ra_svn_conn_t *svn_ra_svn_create_con
&& apr_sockaddr_ip_get(&conn->remote_ip, sa) == APR_SUCCESS))
conn->remote_ip = NULL;
svn_ra_svn__stream_timeout(conn->stream, get_timeout(conn));
+
+ /* We are using large r/w buffers already.
+ * So, once we decide to actually send data, we want it to go over
+ * the wire a.s.a.p.. So disable Nagle's algorithm.
+ *
+ * We ignore the result of this call since it safe to continue even
+ * if we keep delaying. The only negative effect is increased
+ * latency (can be additional 5 .. 10ms depending on circumstances).
+ */
+ apr_socket_opt_set(sock, APR_TCP_NODELAY, 1);
}
else
{
