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| author | John Stultz <john.stultz@linaro.org> | 2012-09-17 21:38:46 -0400 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2013-01-16 16:44:53 -0500 |
| commit | b4e2564c9f5ba83af10076d029a7507b7a33b870 (patch) | |
| tree | 87a6ee636d0380243968b1a60373d0ad9a84db5b /kernel | |
| parent | 11ce0e7a9396b85a6f42cec5ec009d70d7b10652 (diff) | |
| download | linux-b4e2564c9f5ba83af10076d029a7507b7a33b870.tar.gz linux-b4e2564c9f5ba83af10076d029a7507b7a33b870.tar.bz2 linux-b4e2564c9f5ba83af10076d029a7507b7a33b870.zip | |
time: Avoid making adjustments if we haven't accumulated anything
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 <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Ingo Molnar <mingo@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: Paul Gortmaker <paul.gortmaker@windriver.com>
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 0d59077c3fe8..bbdad71aa90f 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -849,6 +849,10 @@ 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; /* |