Page MenuHomeFreeBSD
Files F133436961

D10556.id42095.diff
No OneTemporary
Actions

D10556.id42095.diff
View Options

Index: head/sys/netinet/cc/cc_cubic.h
===================================================================
--- head/sys/netinet/cc/cc_cubic.h
+++ head/sys/netinet/cc/cc_cubic.h
@@ -51,23 +51,23 @@
/* 0.5 << CUBIC_SHIFT. */
#define RENO_BETA 128
-/* ~0.8 << CUBIC_SHIFT. */
-#define CUBIC_BETA 204
+/* ~0.7 << CUBIC_SHIFT. */
+#define CUBIC_BETA 179
-/* ~0.2 << CUBIC_SHIFT. */
-#define ONE_SUB_CUBIC_BETA 51
+/* ~0.3 << CUBIC_SHIFT. */
+#define ONE_SUB_CUBIC_BETA 77
/* 3 * ONE_SUB_CUBIC_BETA. */
-#define THREE_X_PT2 153
+#define THREE_X_PT3 231
/* (2 << CUBIC_SHIFT) - ONE_SUB_CUBIC_BETA. */
-#define TWO_SUB_PT2 461
+#define TWO_SUB_PT3 435
/* ~0.4 << CUBIC_SHIFT. */
#define CUBIC_C_FACTOR 102
-/* CUBIC fast convergence factor: ~0.9 << CUBIC_SHIFT. */
-#define CUBIC_FC_FACTOR 230
+/* CUBIC fast convergence factor: (1+beta_cubic)/2. */
+#define CUBIC_FC_FACTOR 217
/* Don't trust s_rtt until this many rtt samples have been taken. */
#define CUBIC_MIN_RTT_SAMPLES 8
@@ -79,9 +79,8 @@
/*
* Implementation based on the formulae found in the CUBIC Internet Draft
- * "draft-rhee-tcpm-cubic-02".
+ * "draft-ietf-tcpm-cubic-04".
*
- * Note BETA used in cc_cubic is equal to (1-beta) in the I-D
*/
static __inline float
@@ -91,7 +90,7 @@
C = 0.4;
- return (pow((wmax_pkts * 0.2) / C, (1.0 / 3.0)) * pow(2, CUBIC_SHIFT));
+ return (pow((wmax_pkts * 0.3) / C, (1.0 / 3.0)) * pow(2, CUBIC_SHIFT));
}
static __inline unsigned long
@@ -120,7 +119,7 @@
uint32_t smss)
{
- return ((wmax * 0.8) + ((3 * 0.2) / (2 - 0.2) *
+ return ((wmax * 0.7) + ((3 * 0.3) / (2 - 0.3) *
(ticks_since_cong / (float)rtt_ticks) * smss));
}
@@ -232,7 +231,7 @@
/*
* Compute an approximation of the "TCP friendly" cwnd some number of ticks
* after a congestion event that is designed to yield the same average cwnd as
- * NewReno while using CUBIC's beta of 0.8. RTT should be the average RTT
+ * NewReno while using CUBIC's beta of 0.7. RTT should be the average RTT
* estimate for the path measured over the previous congestion epoch and wmax is
* the value of cwnd at the last congestion event.
*/
@@ -242,8 +241,8 @@
{
/* Equation 4 of I-D. */
- return (((wmax * CUBIC_BETA) + (((THREE_X_PT2 * ticks_since_cong *
- smss) << CUBIC_SHIFT) / TWO_SUB_PT2 / rtt_ticks)) >> CUBIC_SHIFT);
+ return (((wmax * CUBIC_BETA) + (((THREE_X_PT3 * ticks_since_cong *
+ smss) << CUBIC_SHIFT) / TWO_SUB_PT3 / rtt_ticks)) >> CUBIC_SHIFT);
}
#endif /* _NETINET_CC_CUBIC_H_ */

File Metadata

Mime Type
text/plain
Expires
Sun, Oct 26, 7:07 PM (4 h, 34 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
24246477
Default Alt Text
D10556.id42095.diff (2 KB)

Event Timeline