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-rw-r--r--kernel/time/timekeeping.c45
1 files changed, 31 insertions, 14 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index ce618010c373..16280ff3cf82 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -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
*
@@ -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);
@@ -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