(Logical change 1.3)

1 files changed, 57 insertions, 0 deletions

diff --git a/tc/tc_cbq.c b/tc/tc_cbq.c
index e69de29b..0abcc9da 100644
--- a/tc/tc_cbq.c
+++ b/tc/tc_cbq.c
@@ -0,0 +1,57 @@
+/*
+ * tc_cbq.c		CBQ maintanance routines.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <math.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+#include "tc_core.h"
+#include "tc_cbq.h"
+
+unsigned tc_cbq_calc_maxidle(unsigned bndw, unsigned rate, unsigned avpkt,
+			     int ewma_log, unsigned maxburst)
+{
+	double maxidle;
+	double g = 1.0 - 1.0/(1<<ewma_log);
+	double xmt = (double)avpkt/bndw;
+
+	maxidle = xmt*(1-g);
+	if (bndw != rate && maxburst) {
+		double vxmt = (double)avpkt/rate - xmt;
+		vxmt *= (pow(g, -(double)maxburst) - 1);
+		if (vxmt > maxidle)
+			maxidle = vxmt;
+	}
+	return tc_core_usec2tick(maxidle*(1<<ewma_log)*1000000);
+}
+
+unsigned tc_cbq_calc_offtime(unsigned bndw, unsigned rate, unsigned avpkt,
+			     int ewma_log, unsigned minburst)
+{
+	double g = 1.0 - 1.0/(1<<ewma_log);
+	double offtime = (double)avpkt/rate - (double)avpkt/bndw;
+
+	if (minburst == 0)
+		return 0;
+	if (minburst == 1)
+		offtime *= pow(g, -(double)minburst) - 1;
+	else
+		offtime *= 1 + (pow(g, -(double)(minburst-1)) - 1)/(1-g);
+	return tc_core_usec2tick(offtime*1000000);
+}