time: ntp: refactor up ntp_update_frequency()

Impact: cleanup, no functionality changed

Change ntp_update_frequency() from a hard to follow code
flow that uses global variables as temporaries, to a clean
input+output flow.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2009-02-22 12:17:36 +01:00
parent 9ce616aaef
commit bc26c31d44

View file

@ -83,10 +83,8 @@ static long ntp_tick_adj;
*/
static void ntp_update_frequency(void)
{
u64 prev_base;
u64 second_length;
prev_base = tick_length_base;
u64 new_base;
second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
<< NTP_SCALE_SHIFT;
@ -94,16 +92,15 @@ static void ntp_update_frequency(void)
second_length += (s64)ntp_tick_adj << NTP_SCALE_SHIFT;
second_length += time_freq;
tick_length_base = second_length;
tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
tick_length_base = div_u64(tick_length_base, NTP_INTERVAL_FREQ);
new_base = div_u64(second_length, NTP_INTERVAL_FREQ);
/*
* Don't wait for the next second_overflow, apply
* the change to the tick length immediately
* the change to the tick length immediately:
*/
tick_length += tick_length_base - prev_base;
tick_length += new_base - tick_length_base;
tick_length_base = new_base;
}
static void ntp_update_offset(long offset)