This is a -stable backport of bf2ac312195155511a0f79325515cbb61929898a 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 <john.stu...@linaro.org> Cc: Prarit Bhargava <pra...@redhat.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: sta...@vger.kernel.org Link: http://lkml.kernel.org/r/1345595449-34965-5-git-send-email-john.stu...@linaro.org Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: Linux Kernel <linux-kernel@vger.kernel.org> Signed-off-by: John Stultz <john.stu...@linaro.org> --- kernel/time/timekeeping.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 36440c88..59544dc 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1033,6 +1033,10 @@ 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; /* -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
