This commit was generated by cvs2svn to compensate for changes in r1650,

[iproute2.git] / tc / tc_cbq.c

diff --git a/tc/tc_cbq.c b/tc/tc_cbq.c
new file mode 100644 (file)
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+++ b/tc/tc_cbq.c
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+/*
+ * 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);
+}