'Internal method: return parameters for CFS bandwidth'

def cfsInfo(self, f):

    (pstr, qstr) = ('cfs_period_us', 'cfs_quota_us')
    quota = int(((self.period_us * f) * numCores()))
    period = self.period_us
    if ((f > 0) and (quota < 1000)):
        debug('(cfsInfo:    increasing    default    period)    ')
        quota = 1000
        period = int(((quota / f) / numCores()))
    if (quota < 0):
        quota = (-1)
    return (pstr, qstr, period, quota)
