svn commit: r232395 - user/andre/tcp_workqueue/sys/netinet

[Andre Oppermann]

Author: andre
Date: Fri Mar  2 15:48:52 2012
New Revision: 232395
URL: http://svn.freebsd.org/changeset/base/232395

Log:
  Defer sending an independent window update if a delayed ACK is pending
  saving a packet.  The window update then gets piggy-backed on the next
  already scheduled ACK.

Modified:
  user/andre/tcp_workqueue/sys/netinet/tcp_output.c

Modified: user/andre/tcp_workqueue/sys/netinet/tcp_output.c
==============================================================================
--- user/andre/tcp_workqueue/sys/netinet/tcp_output.c	Fri Mar  2 14:42:33 2012	(r232394)
+++ user/andre/tcp_workqueue/sys/netinet/tcp_output.c	Fri Mar  2 15:48:52 2012	(r232395)
@@ -542,10 +542,14 @@ after_sack_rexmit:
 	 * max size segments, or at least 50% of the maximum possible
 	 * window, then want to send a window update to peer.
 	 * Skip this if the connection is in T/TCP half-open state.
-	 * Don't send pure window updates when the peer has closed
-	 * the connection and won't ever send more data.
+	 *
+	 * Don't send an independent window update if a delayed
+	 * ACK is pending (it will get piggy-backed on it) or the
+	 * remote side already has done a half-close and won't send
+	 * more data.
 	 */
 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
+	    !(tp->t_flags & TF_DELACK) &&
 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
 		/*
 		 * "adv" is the amount we can increase the window,