| From | Greg Kroah-Hartman <> | Subject | [ 15/23] timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecond | Date | Tue, 17 Jul 2012 17:12:08 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
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From: John Stultz <john.stultz@linaro.org>
This is a backport of fad0c66c4bb836d57a5f125ecd38bed653ca863a which resolves a bug the previous commit.
Commit 6b43ae8a61 (ntp: Fix leap-second hrtimer livelock) broke the leapsecond update of CLOCK_MONOTONIC. The missing leapsecond update to wall_to_monotonic causes discontinuities in CLOCK_MONOTONIC.
Adjust wall_to_monotonic when NTP inserted a leapsecond.
Reported-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Tested-by: Richard Cochran <richardcochran@gmail.com> Link: http://lkml.kernel.org/r/1338400497-12420-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- kernel/time/timekeeping.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -824,6 +824,7 @@ static cycle_t logarithmic_accumulation( xtime.tv_sec++; leap = second_overflow(xtime.tv_sec); xtime.tv_sec += leap; + wall_to_monotonic.tv_sec -= leap; } /* Accumulate raw time */ @@ -934,7 +935,7 @@ static void update_wall_time(void) xtime.tv_sec++; leap = second_overflow(xtime.tv_sec); xtime.tv_sec += leap; - + wall_to_monotonic.tv_sec -= leap; } /* check to see if there is a new clocksource to use */
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