/* Adjust for the fact that psched_ticks aren't always usecs
(based on kernel PSCHED_CLOCK configuration */
static int get_ticks(__u32 *ticks, const char *str)
{
unsigned t;
if(get_usecs(&t, str))
return -1;
*ticks = tc_core_usec2tick(t);
return 0;
}
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);
}
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_calc_xmittime(unsigned rate, unsigned size)
{
return tc_core_usec2tick(1000000*((double)size/rate));
}
