[TCP]: cubic update for net-2.6.22
The following update received from Injong updates TCP cubic to the latest
version. I am running more complete tests and will have results after 4/1.
According to Injong: the new version improves on its scalability,
fairness and stability. So in all properties, we confirmed it shows better
performance.
NCSU results (for 2.6.18 and 2.6.20) available:
http://netsrv.csc.ncsu.edu/wiki/index.php/TCP_Testing
This version is described in a new Internet draft for CUBIC.
http://www.ietf.org/internet-drafts/draft-rhee-tcp-cubic-00.txt
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 15c5803..296845b 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -1,5 +1,5 @@
/*
- * TCP CUBIC: Binary Increase Congestion control for TCP v2.0
+ * TCP CUBIC: Binary Increase Congestion control for TCP v2.1
*
* This is from the implementation of CUBIC TCP in
* Injong Rhee, Lisong Xu.
@@ -214,7 +214,9 @@
if (ca->delay_min > 0) {
/* max increment = Smax * rtt / 0.1 */
min_cnt = (cwnd * HZ * 8)/(10 * max_increment * ca->delay_min);
- if (ca->cnt < min_cnt)
+
+ /* use concave growth when the target is above the origin */
+ if (ca->cnt < min_cnt && t >= ca->bic_K)
ca->cnt = min_cnt;
}
@@ -400,4 +402,4 @@
MODULE_AUTHOR("Sangtae Ha, Stephen Hemminger");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CUBIC TCP");
-MODULE_VERSION("2.0");
+MODULE_VERSION("2.1");