diff options
| author | John Stultz <john.stultz@linaro.org> | 2012-09-17 22:32:09 -0400 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2012-10-07 23:37:10 +0200 |
| commit | 61b76840ddee647c0c223365378c3f394355b7d7 (patch) | |
| tree | a05b676e287ef77271da909e69ed4e1ad58c2f01 /kernel | |
| parent | 436b6be6cb5bbffb227b5a414e7a1c03fe941b43 (diff) | |
time: Avoid making adjustments if we haven't accumulated anything
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.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1345595449-34965-5-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/timekeeping.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 85d51c4707e7..b451c9376f44 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -807,6 +807,10 @@ void update_wall_time(void) #else offset = timekeeper.cycle_interval; #endif + /* Check if there's really nothing to do */ + if (offset < timekeeper.cycle_interval) + return; + timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; /* normally this loop will run just once, however in the |