time: ntp: simplify the second_overflow() code flow

Impact: cleanup, no functionality changed

Instead of a hierarchy of conditions, transform them to clean
gradual conditions and return's.

This makes the flow easier to read and makes the purpose of
the function easier to understand.

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2552	    170	    168	   2890	    b4a	ntp.o.before
   2552	    170	    168	   2890	    b4a	ntp.o.after

md5:
   eae1275df0b7d6290c13f6f6f8f05c8c  ntp.o.before.asm
   eae1275df0b7d6290c13f6f6f8f05c8c  ntp.o.after.asm

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2009-02-22 12:06:57 +01:00
parent 53bbfa9e94
commit 3c972c2444

View file

@ -232,19 +232,24 @@ void second_overflow(void)
time_offset -= time_adj;
tick_length += time_adj;
if (unlikely(time_adjust)) {
if (time_adjust > MAX_TICKADJ) {
time_adjust -= MAX_TICKADJ;
tick_length += MAX_TICKADJ_SCALED;
} else if (time_adjust < -MAX_TICKADJ) {
time_adjust += MAX_TICKADJ;
tick_length -= MAX_TICKADJ_SCALED;
} else {
tick_length += (s64)(time_adjust * NSEC_PER_USEC /
NTP_INTERVAL_FREQ) << NTP_SCALE_SHIFT;
time_adjust = 0;
}
if (!time_adjust)
return;
if (time_adjust > MAX_TICKADJ) {
time_adjust -= MAX_TICKADJ;
tick_length += MAX_TICKADJ_SCALED;
return;
}
if (time_adjust < -MAX_TICKADJ) {
time_adjust += MAX_TICKADJ;
tick_length -= MAX_TICKADJ_SCALED;
return;
}
tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
<< NTP_SCALE_SHIFT;
time_adjust = 0;
}
#ifdef CONFIG_GENERIC_CMOS_UPDATE