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yaml
---
r: 333876
b: refs/heads/master
c: 92bb1fc
h: refs/heads/master
v: v3
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John Stultz committed Sep 24, 2012
1 parent 562d227 commit f20442c
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Showing 2 changed files with 32 additions and 15 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 576094b7f0aaf41aadab9b7d4e5bd85faa432711
refs/heads/master: 92bb1fcf57a0c2e45f7e67fbf0a8ed475a749236
45 changes: 31 additions & 14 deletions trunk/kernel/time/timekeeping.c
Original file line number Diff line number Diff line change
Expand Up @@ -1062,6 +1062,33 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
return offset;
}

#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
static inline void old_vsyscall_fixup(struct timekeeper *tk)
{
s64 remainder;

/*
* Store only full nanoseconds into xtime_nsec after rounding
* it up and add the remainder to the error difference.
* XXX - This is necessary to avoid small 1ns inconsistnecies caused
* by truncating the remainder in vsyscalls. However, it causes
* additional work to be done in timekeeping_adjust(). Once
* the vsyscall implementations are converted to use xtime_nsec
* (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
* users are removed, this can be killed.
*/
remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
tk->xtime_nsec -= remainder;
tk->xtime_nsec += 1ULL << tk->shift;
tk->ntp_error += remainder << tk->ntp_error_shift;

}
#else
#define old_vsyscall_fixup(tk)
#endif



/**
* update_wall_time - Uses the current clocksource to increment the wall time
*
Expand All @@ -1073,7 +1100,6 @@ static void update_wall_time(void)
cycle_t offset;
int shift = 0, maxshift;
unsigned long flags;
s64 remainder;

write_seqlock_irqsave(&tk->lock, flags);

Expand Down Expand Up @@ -1115,20 +1141,11 @@ static void update_wall_time(void)
/* correct the clock when NTP error is too big */
timekeeping_adjust(tk, offset);


/*
* Store only full nanoseconds into xtime_nsec after rounding
* it up and add the remainder to the error difference.
* XXX - This is necessary to avoid small 1ns inconsistnecies caused
* by truncating the remainder in vsyscalls. However, it causes
* additional work to be done in timekeeping_adjust(). Once
* the vsyscall implementations are converted to use xtime_nsec
* (shifted nanoseconds), this can be killed.
*/
remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
tk->xtime_nsec -= remainder;
tk->xtime_nsec += 1ULL << tk->shift;
tk->ntp_error += remainder << tk->ntp_error_shift;
* XXX This can be killed once everyone converts
* to the new update_vsyscall.
*/
old_vsyscall_fixup(tk);

/*
* Finally, make sure that after the rounding
Expand Down

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