| | Date | Mon, 23 Jul 2012 02:08:07 +0100 | | From | Ben Hutchings <> | | Subject | [ 076/108] timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecond |
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3.2-stable review patch. If anyone has any objections, please let me know.
------------------ 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> Cc: Linux Kernel <linux-kernel@vger.kernel.org> Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- kernel/time/timekeeping.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 4780a7d..5c9b67e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -938,6 +938,7 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) xtime.tv_sec++; leap = second_overflow(xtime.tv_sec); xtime.tv_sec += leap; + wall_to_monotonic.tv_sec -= leap; } /* Accumulate raw time */ @@ -1048,7 +1049,7 @@ 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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