round_freq
freq = round_freq(timer, freq);
static int round_freq(struct eventtimer *et, int freq);
base = round_freq(timer, hz * singlemul);
profhz = round_freq(timer, profhz);
hz = round_freq(timer, hz);
stathz = round_freq(timer, 127);
profhz = round_freq(timer, stathz * 64);