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time: Refactor accumulation of nsecs to secs

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We do the exact same logic moving nsecs to secs in the
timekeeper in multiple places, so condense this into a
single function.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-6-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
John Stultz 2012-07-13 01:21:54 -04:00 committed by Thomas Gleixner
parent 1e75fa8be9
commit 1f4f948706
1 changed files with 32 additions and 22 deletions
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54
kernel/time/timekeeping.c
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@ -990,6 +990,35 @@ static void timekeeping_adjust(s64 offset)
} }
/**
* accumulate_nsecs_to_secs - Accumulates nsecs into secs
*
* Helper function that accumulates a the nsecs greater then a second
* from the xtime_nsec field to the xtime_secs field.
* It also calls into the NTP code to handle leapsecond processing.
*
*/
static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
{
u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
while (tk->xtime_nsec >= nsecps) {
int leap;
tk->xtime_nsec -= nsecps;
tk->xtime_sec++;
/* Figure out if its a leap sec and apply if needed */
leap = second_overflow(tk->xtime_sec);
tk->xtime_sec += leap;
tk->wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
}
/** /**
* logarithmic_accumulation - shifted accumulation of cycles * logarithmic_accumulation - shifted accumulation of cycles
* *
@ -1001,7 +1030,6 @@ static void timekeeping_adjust(s64 offset)
*/ */
static cycle_t logarithmic_accumulation(cycle_t offset, u32 shift) static cycle_t logarithmic_accumulation(cycle_t offset, u32 shift)
{ {
u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
u64 raw_nsecs; u64 raw_nsecs;
/* If the offset is smaller than a shifted interval, do nothing */ /* If the offset is smaller than a shifted interval, do nothing */
@ -1013,16 +1041,8 @@ static cycle_t logarithmic_accumulation(cycle_t offset, u32 shift)
timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift; timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift;
timekeeper.xtime_nsec += timekeeper.xtime_interval << shift; timekeeper.xtime_nsec += timekeeper.xtime_interval << shift;
while (timekeeper.xtime_nsec >= nsecps) {
int leap; accumulate_nsecs_to_secs(&timekeeper);
timekeeper.xtime_nsec -= nsecps;
timekeeper.xtime_sec++;
leap = second_overflow(timekeeper.xtime_sec);
timekeeper.xtime_sec += leap;
timekeeper.wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
/* Accumulate raw time */ /* Accumulate raw time */
raw_nsecs = timekeeper.raw_interval << shift; raw_nsecs = timekeeper.raw_interval << shift;
@ -1132,17 +1152,7 @@ static void update_wall_time(void)
* Finally, make sure that after the rounding * Finally, make sure that after the rounding
* xtime_nsec isn't larger than NSEC_PER_SEC * xtime_nsec isn't larger than NSEC_PER_SEC
*/ */
if (unlikely(timekeeper.xtime_nsec >= accumulate_nsecs_to_secs(&timekeeper);
((u64)NSEC_PER_SEC << timekeeper.shift))) {
int leap;
timekeeper.xtime_nsec -= (u64)NSEC_PER_SEC << timekeeper.shift;
timekeeper.xtime_sec++;
leap = second_overflow(timekeeper.xtime_sec);
timekeeper.xtime_sec += leap;
timekeeper.wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
timekeeping_update(false); timekeeping_update(false);