do not delay TCP acks (Ed Swierk)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1882 c046a42c-6fe2-441c-8c8c-71466251a162

diff --git a/slirp/tcp_input.c b/slirp/tcp_input.c
index 8729d76..c015161 100644 (file)
--- a/slirp/tcp_input.c
+++ b/slirp/tcp_input.c
@@ -580,28 +580,11 @@ findso:
                         *      congestion avoidance sender won't send more until
                         *      he gets an ACK.
                         * 
-                        * Here are 3 interpretations of what should happen.
-                        * The best (for me) is to delay-ack everything except
-                        * if it's a one-byte packet containing an ESC
-                        * (this means it's an arrow key (or similar) sent using
-                        * Nagel, hence there will be no echo)
-                        * The first of these is the original, the second is the
-                        * middle ground between the other 2
+                        * It is better to not delay acks at all to maximize
+                        * TCP throughput.  See RFC 2581.
                         */ 
-/*                     if (((unsigned)ti->ti_len < tp->t_maxseg)) {
- */                         
-/*                     if (((unsigned)ti->ti_len < tp->t_maxseg && 
- *                          (so->so_iptos & IPTOS_LOWDELAY) == 0) ||
- *                         ((so->so_iptos & IPTOS_LOWDELAY) && 
- *                          ((struct tcpiphdr_2 *)ti)->first_char == (char)27)) {
- */
-                       if ((unsigned)ti->ti_len == 1 &&
-                           ((struct tcpiphdr_2 *)ti)->first_char == (char)27) {
-                               tp->t_flags |= TF_ACKNOW;
-                               tcp_output(tp);
-                       } else {
-                               tp->t_flags |= TF_DELACK;
-                       }
+                       tp->t_flags |= TF_ACKNOW;
+                       tcp_output(tp);
                        return;
                }
        } /* header prediction */