time: ntp: clean up ntp_update_frequency()

Impact: cleanup, no functionality changed

Prepare a refactoring of ntp_update_frequency().

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2504	    114	    136	   2754	    ac2	ntp.o.before
   2504	    114	    136	   2754	    ac2	ntp.o.after

md5:
   41f3009debc9b397d7394dd77d912f0a  ntp.o.before.asm
   41f3009debc9b397d7394dd77d912f0a  ntp.o.after.asm

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 18 insertions, 9 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 2b758c935c65..7d281d9fbe30 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -77,24 +77,33 @@ static long			ntp_tick_adj;
  * NTP methods:
  */
 
+/*
+ * Update (tick_length, tick_length_base, tick_nsec), based
+ * on (tick_usec, ntp_tick_adj, time_freq):
+ */
 static void ntp_update_frequency(void)
 {
-        u64 old_tick_length_base = tick_length_base;
-        u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
-                                << NTP_SCALE_SHIFT;
-        second_length += (s64)ntp_tick_adj << NTP_SCALE_SHIFT;
-        second_length += time_freq;
+        u64 prev_base;
+        u64 second_length;
+
+        prev_base = tick_length_base;
+
+        second_length            = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
+                                                << NTP_SCALE_SHIFT;
+
+        second_length           += (s64)ntp_tick_adj << NTP_SCALE_SHIFT;
+        second_length           += time_freq;
 
-        tick_length_base = second_length;
+        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);
+        tick_nsec                = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
+        tick_length_base         = div_u64(tick_length_base, NTP_INTERVAL_FREQ);
 
         /*
          * Don't wait for the next second_overflow, apply
          * the change to the tick length immediately
          */
-        tick_length += tick_length_base - old_tick_length_base;
+        tick_length             += tick_length_base - prev_base;
 }
 
 static void ntp_update_offset(long offset)