[DCCP] CCID2: Tell DCCP to quickly check whether cwnd is available

If not enough cwnd is available, tell the sender to check again as
soon as possible.  This will increase CPU utilization (polling
frequently for cwnd) but will improve network performance.  That is,
the sender will need to wait less before detecting the increase of
cwnd.  A better architecture would be for the CCID to call-back (or
dequeue) from DCCP when it is able to transmit traffic -- not the
other way around as it currently occurs.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dccp/ccids/ccid2.c

@@ -122,7 +122,7 @@ static int ccid2_hc_tx_send_packet(struct sock *sk,
 		}
 	}
 
-	return 100; /* XXX */
+	return 1; /* XXX CCID should dequeue when ready instead of polling */
 }
 
 static void ccid2_change_l_ack_ratio(struct sock *sk, int val)