patch-1.3.75 linux/include/net/tcp.h

• Lines: 42
• Date: Sat Mar 16 18:21:19 1996
• Orig file: v1.3.74/linux/include/net/tcp.h
• Orig date: Tue Feb 20 14:37:28 1996

diff -u --recursive --new-file v1.3.74/linux/include/net/tcp.h linux/include/net/tcp.h
@@ -179,25 +179,33 @@
  *  
  *	1. The window can never be shrunk once it is offered (RFC 793)
  *	2. We limit memory per socket
+ *	3. No reason to raise the window if the other side has
+ *	   lots of room to play with.
  */
 
 static __inline__ unsigned short tcp_raise_window(struct sock *sk)
 {
-	long free_space = sock_rspace(sk);
+	long free_space;
 	long window;
 
-	if (free_space > 1024)
-		free_space &= ~0x3FF; /* make free space a multiple of 1024 */
 
-	if(sk->window_clamp)
-		free_space = min(sk->window_clamp, free_space);
- 
 	/* 
          * compute the actual window i.e. 
-         * old_window - received_bytes_on_that_win 
+         * old_window - received_bytes_on_that_win.
+	 *
+	 * Don't raise the window if we have lots left:
+	 * that only results in unnecessary packets.
 	 */
+	window = sk->window - (sk->acked_seq - sk->lastwin_seq);	
+	if (window >= MAX_WINDOW/2)
+		return 0;
 
-	window = sk->window - (sk->acked_seq - sk->lastwin_seq);
+	free_space = sock_rspace(sk);
+	if (free_space > 1024)
+		free_space &= ~0x3FF; /* make free space a multiple of 1024 */
+
+	if(sk->window_clamp)
+		free_space = min(sk->window_clamp, free_space);
 
 	if (sk->mss == 0)
 		sk->mss = sk->mtu;