add patch to revert condition that can set RTT=0

[linux-2.6.git] / linux-2.6-720-undo-rttzero.patch

diff --git a/linux-2.6-720-undo-rttzero.patch b/linux-2.6-720-undo-rttzero.patch
new file mode 100644 (file)
index 0000000..526f3f5
--- /dev/null
+++ b/linux-2.6-720-undo-rttzero.patch
@@ -0,0 +1,17 @@
+diff -Ndur linux-2.6.32-orig/net/ipv4/tcp_input.c linux-2.6.32-undorttzero/net/ipv4/tcp_input.c
+--- linux-2.6.32-orig/net/ipv4/tcp_input.c     2013-06-05 15:47:10.551009408 -0400
++++ linux-2.6.32-undorttzero/net/ipv4/tcp_input.c      2013-06-05 15:49:32.458996663 -0400
+@@ -5783,9 +5783,11 @@
+ 
+                               /* tcp_ack considers this ACK as duplicate
+                                * and does not calculate rtt.
+-                               * Force it here.
++                               * Fix it at least with timestamps.
+                                */
+-                              tcp_ack_update_rtt(sk, 0, 0);
++                              if (tp->rx_opt.saw_tstamp && 
++                                      tp->rx_opt.rcv_tsecr && !tp->srtt)
++                                              tcp_ack_saw_tstamp(sk, 0);
+ 
+                               if (tp->rx_opt.tstamp_ok)
+                                       tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;