Re: [RFC][PATCH 0/4] Fixes for leapsecond expiring early ABS_TIME CLOCK_REALTIME timers

[Prarit Bhargava <prarit@redhat.com>]

On 05/29/2015 04:24 PM, John Stultz wrote:
> As Prarit reported here:
> https://lkml.org/lkml/2015/5/27/458
> 
> Since the leapsecond is applied at timer tick time, and not
> the actual second edge, ABS_TIME CLOCK_REALTIME timers set for
> right after the leapsecond could fire a second early, since
> some timers may be expired before we trigger the timekeeping
> timer, which then applies the leapsecond.
> 
> Thus this patch series tries to address this isssue, including
> extending the leap-a-day test to catch this problem, as well
> as other relevant fixups I found while working on the code.
> 
> This series has only had limited testing, so I wanted to send
> it out for initial review and comment. Folks can grab this tree
> via git for testing here:
> https://git.linaro.org/people/john.stultz/linux.git dev/early-leap-timer
> 
> Thougths and feedback would be appreciated!


Testing now ...

P.

> thanks
> -john
> 
> Cc: Prarit Bhargava <prarit@redhat.com>
> Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
> Cc: Richard Cochran <richardcochran@gmail.com>
> Cc: Jan Kara <jack@suse.cz>
> Cc: Jiri Bohac <jbohac@suse.cz>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Shuah Khan <shuahkh@osg.samsung.com>
> 
> John Stultz (4):
>   selftests: timers: Add leap-second timer edge testing to leap-a-day.c
>   timer_list: Add the base offset so remaining nsecs are accurate for
>     non monotonic timers
>   ntp: Use printk_deferred in leapsecond path
>   time: Do leapsecond adjustment in gettime fastpaths
> 
>  include/linux/time64.h                      |  1 +
>  include/linux/timekeeper_internal.h         |  7 +++
>  kernel/time/ntp.c                           | 77 ++++++++++++++++++++---
>  kernel/time/ntp_internal.h                  |  1 +
>  kernel/time/timekeeping.c                   | 97 +++++++++++++++++++++++++----
>  kernel/time/timer_list.c                    |  2 +-
>  tools/testing/selftests/timers/leap-a-day.c | 76 ++++++++++++++++++++--
>  7 files changed, 234 insertions(+), 27 deletions(-)
>