From: John Stultz <[email protected]> ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
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]> Cc: Linux Kernel <[email protected]> Signed-off-by: John Stultz <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- kernel/time/timekeeping.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 0d59077..bbdad71 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; /* -- 1.7.12.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
