3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: John Stultz <[email protected]>

commit bf2ac312195155511a0f79325515cbb61929898a upstream

If update_wall_time() is called and the current offset isn't large
enough to accumulate, avoid re-calling timekeeping_adjust which may
change the clock freq and can cause 1ns inconsistencies with
CLOCK_REALTIME_COARSE/CLOCK_MONOTONIC_COARSE.

Signed-off-by: John Stultz <[email protected]>
Cc: Prarit Bhargava <[email protected]>
Cc: Ingo Molnar <[email protected]>
Link: 
http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 kernel/time/timekeeping.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -919,6 +919,10 @@ static void update_wall_time(void)
 #else
        offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
+       /* Check if there's really nothing to do */
+       if (offset < timekeeper.cycle_interval)
+               return;
+
        timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
 
        /*


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