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-rw-r--r--net/ipv4/tcp_cubic.c35
1 files changed, 8 insertions, 27 deletions
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 3aa0b23c1ea..eb5b9854c8c 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -1,12 +1,13 @@
/*
- * TCP CUBIC: Binary Increase Congestion control for TCP v2.1
- *
+ * TCP CUBIC: Binary Increase Congestion control for TCP v2.2
+ * Home page:
+ * http://netsrv.csc.ncsu.edu/twiki/bin/view/Main/BIC
* This is from the implementation of CUBIC TCP in
* Injong Rhee, Lisong Xu.
* "CUBIC: A New TCP-Friendly High-Speed TCP Variant
* in PFLDnet 2005
* Available from:
- * http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
+ * http://netsrv.csc.ncsu.edu/export/cubic-paper.pdf
*
* Unless CUBIC is enabled and congestion window is large
* this behaves the same as the original Reno.
@@ -20,15 +21,10 @@
#define BICTCP_BETA_SCALE 1024 /* Scale factor beta calculation
* max_cwnd = snd_cwnd * beta
*/
-#define BICTCP_B 4 /*
- * In binary search,
- * go to point (max+min)/N
- */
#define BICTCP_HZ 10 /* BIC HZ 2^10 = 1024 */
static int fast_convergence __read_mostly = 1;
-static int max_increment __read_mostly = 16;
-static int beta __read_mostly = 819; /* = 819/1024 (BICTCP_BETA_SCALE) */
+static int beta __read_mostly = 717; /* = 717/1024 (BICTCP_BETA_SCALE) */
static int initial_ssthresh __read_mostly;
static int bic_scale __read_mostly = 41;
static int tcp_friendliness __read_mostly = 1;
@@ -40,9 +36,7 @@ static u64 cube_factor __read_mostly;
/* Note parameters that are used for precomputing scale factors are read-only */
module_param(fast_convergence, int, 0644);
MODULE_PARM_DESC(fast_convergence, "turn on/off fast convergence");
-module_param(max_increment, int, 0644);
-MODULE_PARM_DESC(max_increment, "Limit on increment allowed during binary search");
-module_param(beta, int, 0444);
+module_param(beta, int, 0644);
MODULE_PARM_DESC(beta, "beta for multiplicative increase");
module_param(initial_ssthresh, int, 0644);
MODULE_PARM_DESC(initial_ssthresh, "initial value of slow start threshold");
@@ -145,7 +139,7 @@ static u32 cubic_root(u64 a)
static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
{
u64 offs;
- u32 delta, t, bic_target, min_cnt, max_cnt;
+ u32 delta, t, bic_target, max_cnt;
ca->ack_cnt++; /* count the number of ACKs */
@@ -211,19 +205,6 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
ca->cnt = 100 * cwnd; /* very small increment*/
}
- if (ca->delay_min > 0) {
- /* max increment = Smax * rtt / 0.1 */
- min_cnt = (cwnd * HZ * 8)/(10 * max_increment * ca->delay_min);
-
- /* use concave growth when the target is above the origin */
- if (ca->cnt < min_cnt && t >= ca->bic_K)
- ca->cnt = min_cnt;
- }
-
- /* slow start and low utilization */
- if (ca->loss_cwnd == 0) /* could be aggressive in slow start */
- ca->cnt = 50;
-
/* TCP Friendly */
if (tcp_friendliness) {
u32 scale = beta_scale;
@@ -391,4 +372,4 @@ module_exit(cubictcp_unregister);
MODULE_AUTHOR("Sangtae Ha, Stephen Hemminger");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CUBIC TCP");
-MODULE_VERSION("2.1");
+MODULE_VERSION("2.2");